WorldWideScience

Sample records for hot working conditions

  1. Chapter 2. Experimental testing methods of materials under hot working conditions

    International Nuclear Information System (INIS)

    Rossard, C.

    1976-01-01

    The deformation under hot working conditions is defined and the purpose of laboratory tests is explained: strength, structure, hot-workability. The concepts of generalized stress strain and strain rate are introduced. These concepts find an interesting application in the equivalence principle. The different testing methods (tension, compression, torsion) and their possibilities are reviewed. The softening mechanisms are recalled: dynamic recovery and recrystallization, static and post-dynamic recrystallization. To explain the possibilities of simulation tests in hot working conditions, some examples are given: the evaluation of the stress-strain relationship (effect of the mechanical and thermal history); the determination of structural behavior (quenching, controled cooling law, decomposition kinetics) [fr

  2. Influence of Hot-Working Conditions on High-Temperature Properties of a Heat-Resistant Alloy

    Science.gov (United States)

    Ewing, John F; Freeman, J W

    1957-01-01

    The relationships between conditions of hot-working and properties at high temperatures and the influence of the hot-working on response to heat treatment were investigated for an alloy containing nominally 20 percent molybdenum, 2 percent tungsten, and 1 percent columbium. Commercially produced bar stock was solution-treated at 2,200 degrees F. to minimize prior-history effects and then rolled at temperatures of 2,200 degrees, 2,100 degrees, 2,000 degrees, 1,800 degrees, and 1,600 degrees F. Working was carried out at constant temperature and with incremental decreases in temperature simulating a falling temperature during hot-working. In addition, a few special repeated cyclic conditions involving a small reduction at high temperature followed by a small reduction at a low temperature were used to study the possibility of inducing very low strengths by the extensive precipitation accompanying such properties. Most of the rolling was done in open passes with a few check tests being made with closed passes. Heat treatments at both 2,050 degrees and 2,200 degrees F. subsequent to working were used to study the influence on response to heat treatment.

  3. Effect of fabric stuff of work clothing on the physiological strain index at hot conditions in the climatic chamber

    Directory of Open Access Journals (Sweden)

    Habibollah Dehghan

    2014-01-01

    Full Text Available Aims: The purpose of the present study was to evaluate the effect of fabric stuff of work clothing that are widely used in Iran industries on the physiological strain index (PSI at hot conditions in the climatic chamber. Materials and Methods: This interventional study was performed upon 18 male students in 16 trials, which included combination of four kinds of work clothing (13.7% viscose (VIS 86.3% polyester(PES, 30.2% cotton [CT]-69.8% PES, 68.5% CT-31.5% PES, 100% CT, two activity levels (light and moderate and two kinds of climatic conditions included hot-wet (T a = 35, RH = 70% and hot-dry (T a = 38, RH = 40%. During each trial, the RH and core temperature was recorded once a minute and then PSI was calculated. Data were analyzed by using SPSS-16 software. Results: The results showed that in hot-wet conditions, the least value of PSI in light and moderate activities was related to 100% CT clothing and 30.2% CT-69.8% PES clothing, respectively. In hot-dry conditions, the least value of PSI in both of activities was related to 30.2% CT-69.8% PES clothing. The mean value of PSI in hot-wet conditions, during moderate activity had significant difference for various clothing types (P = 0.044. Conclusion: The research findings showed that for a heat strain reduction in hot-wet conditions at light activity level, 100% CT clothing is suitable. Furthermore, at moderate activity level, 30.2% CT-69.8% PES clothing and in hot-dry conditions, 30.2% CT-69.8% PES is suitable.

  4. Adding sleep restriction to the equation: impact on wildland firefighters' work performance and physiology in hot conditions.

    Science.gov (United States)

    Vincent, Grace E; Ferguson, Sally; Larsen, Brianna; Ridgers, Nicola D; Snow, Rod; Aisbett, Brad

    2018-04-06

    To examine the effects of sleep restriction on firefighters' physical task performance, physical activity, and physiological and perceived exertion during simulated hot wildfire conditions. 31 firefighters were randomly allocated to either the hot (n = 18, HOT; 33 °C, 8-h sleep opportunity) or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Intermittent, self-paced work circuits of six firefighting tasks were performed for 3 days. Firefighters self-reported ratings of perceived exertion. Heart rate, core temperature, and physical activity were measured continuously. Fluids were consumed ad libitum, and all food and fluids consumed were recorded. Urine volume and urine specific gravity (USG) were analysed and sleep was assessed using polysomnography (PSG). There were no differences between the HOT and HOT + SR groups in firefighters' physical task performance, heart rate, core temperature, USG, or fluid intake. Ratings of perceived exertion were higher (p HOT + SR group for two of the six firefighting tasks. The HOT group spent approximately 7 min more undertaking moderate physical activity throughout the 2-h work circuits compared to the HOT + SR group. Two nights of sleep restriction did not influence firefighters' physical task performance or physiological responses during 3 days of simulated wildfire suppression. Further research is needed to explore firefighters' pacing strategies during real wildfire suppression.

  5. Hot conditioning equipment conceptual design report

    International Nuclear Information System (INIS)

    Bradshaw, F.W.

    1996-01-01

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage

  6. Hot conditioning equipment conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, F.W., Westinghouse Hanford

    1996-08-06

    This report documents the conceptual design of the Hot Conditioning System Equipment. The Hot conditioning System will consist of two separate designs: the Hot Conditioning System Equipment; and the Hot Conditioning System Annex. The Hot Conditioning System Equipment Design includes the equipment such as ovens, vacuum pumps, inert gas delivery systems, etc.necessary to condition spent nuclear fuel currently in storage in the K Basins of the Hanford Site. The Hot Conditioning System Annex consists of the facility of house the Hot Conditioning System. The Hot Conditioning System will be housed in an annex to the Canister Storage Building. The Hot Conditioning System will consist of pits in the floor which contain ovens in which the spent nuclear will be conditioned prior to interim storage.

  7. Control of microstructure during hot working of zirconium alloys

    International Nuclear Information System (INIS)

    Chakravartty, J.K.; Banerjee, S.

    2005-01-01

    Hot working is considered to be the most important step involved in the fabrication of zirconium alloys for nuclear reactor applications for two reasons: i) the scale of the microstructure and texture of the final product is decided at this stage and ii) the hot deformed microstructure provides a suitable starting microstructure for the subsequent fabrication steps. The resultant microstructure in turn controls the properties of the final product. In order to obtain final product with a suitable microstructure and with specified mechanical properties on a repeatable basis the control of microstructure during hot working is of paramount importance. This is usually done by studying the constitutive behaviour of the material under hot working conditions and by constructing processing maps. In the latter method, strain rate sensitivity is mapped as a function of temperature and strain rate to delineate domains within the bounds of which a specific deformation mechanism dominates. Detail microstructural analysis is then carried out on the samples deformed within the domains. Using this methodology, processing maps have been constructed for various zirconium alloys. These maps have been found to be very useful for optimizing the hot workability and control of microstructure of zirconium alloys. (author)

  8. 40 CFR 68.85 - Hot work permit.

    Science.gov (United States)

    2010-07-01

    ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 3 Prevention Program § 68.85 Hot work permit. (a) The owner or operator shall issue a hot work permit for hot work operations conducted on or near a covered process. (b...

  9. Non-Metallic Inclusions and Hot-Working Behaviour of Advanced High-Strength Medium-Mn Steels

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2016-06-01

    Full Text Available The work addresses the production of medium-Mn steels with an increased Al content. The special attention is focused on the identification of non-metallic inclusions and their modification using rare earth elements. The conditions of the thermomechanical treatment using the metallurgical Gleeble simulator and the semi-industrial hot rolling line were designed for steels containing 3 and 5% Mn. Hot-working conditions and controlled cooling strategies with the isothermal holding of steel at 400°C were selected. The effect of Mn content on the hot-working behaviour and microstructure of steel was addressed. The force-energetic parameters of hot rolling were determined. The identification of structural constituents was performed using light microscopy and scanning electron microscopy methods. The addition of rare earth elements led to the total modification of non-metallic inclusions, i.e., they replaced Mn and Al forming complex oxysulphides. The Mn content in a range between 3 and 5% does not affect the inclusion type and the hot-working behaviour. In contrast, it was found that Mn has a significant effect on a microstructure.

  10. Hot Deformation Behavior of Hot-Extruded AA7175 Through Hot Torsion Tests.

    Science.gov (United States)

    Lee, Se-Yeon; Jung, Taek-Kyun; Son, Hyeon-Woo; Kim, Sang-Wook; Son, Kwang-Tae; Choi, Ho-Joon; Oh, Sang-Ho; Lee, Ji-Woon; Hyun, Soong-Keun

    2018-03-01

    The hot deformation behavior of hot-extruded AA7175 was investigated with flow curves and processing maps through hot torsion tests. The flow curves and the deformed microstructures revealed that dynamic recrystallization (DRX) occurred in the hot-extruded AA7175 during hot working. The failure strain was highest at medium temperature. This was mainly influenced by the dynamic precipitation of fine rod-shaped MgZn2. The processing map determined the optimal deformation condition for the alloy during hot working.

  11. Work strain in decontamination of hot cells, 2

    International Nuclear Information System (INIS)

    Kinouchi, Nobuyuki; Ikezawa, Yoshio

    1991-01-01

    In decontamination of hot cells, the workers should wear suitable protective clothing to protect them from internal exposure and skin contamination. But such protective clothing causes some work strain, especially heat-stress. As a simple method to evaluate quantitative work strain, we used sweat rates of the wearers. In the previous paper, sweat rates for workers with two types of protective clothing were reported. In the present paper, sweat rates under severer working conditions are measured for three types: (1) pressure ventilated blouse; (2) full-face mask and polyethylene coverall; (3) full-face mask and vinyl anorak. The measured values for 65 subjects widely scatter from 0.2 to 2.5 l/h for all the protective clothing. Based on these values, the effects of protective clothing and working conditions (ambient temperature and humidity) on work strain are discussed. (author)

  12. Hot-working behavior of cast Pr-Fe-B magnets

    International Nuclear Information System (INIS)

    Shimoda, T.; Akioka, K.; Kobayashi, O.; Yamagami, T.; Ohki, T.; Miyagawa, M.; Yuri, T.

    1989-01-01

    The hot-working behavior of cast Pr-Fe-B magnets is investigated. The hot-working is done both at a low strain rate (hot-pressing) and a high strain rate (hot-rolling). Magnetic alignment induced by the hot-working is found to be closely related to the macrostructure of the cast ingots and the direction of principal stress. The appropriate structure is a columnar structure. The c-axis of the Pr2Fe14B phase is lying in the plane perpendicular to the growth direction of the dendrites. The principal stress during working should be given perpendicular to the growth direction

  13. Microscopic characterizations of membrane electrode assemblies prepared under different hot-pressing conditions

    International Nuclear Information System (INIS)

    Liang, Z.X.; Zhao, T.S.; Xu, C.; Xu, J.B.

    2007-01-01

    The durability of the membrane electrode assembly (MEA) for direct methanol fuel cells (DMFCs) is one of the most critical issues to be addressed before widespread commercialization of the DMFC technology. In this work, we investigated the effect of the hot-pressing duration on the performance and durability of the MEA prepared by hot-pressing technique. It was found that the 60-min hot pressing at 135 deg. C under the pressure of 4.0 MPa yielded a significantly improved MEA durability than did the 3-min hot pressing (a typical duration in practice) under the same condition, but no substantial difference was found in the cell performance of the MEAs prepared with the two different hot-pressing durations. The reason why the hot-pressing duration had no significant effect on cell performance is explained based on X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) characterizations of the changes in the physiochemical properties of MEAs and their constituent components, including the anode, cathode and Nafion membrane, before and after hot pressing with different durations

  14. Post-exercise cooling techniques in hot, humid conditions.

    Science.gov (United States)

    Barwood, Martin James; Davey, Sarah; House, James R; Tipton, Michael J

    2009-11-01

    Major sporting events are often held in hot and humid environmental conditions. Cooling techniques have been used to reduce the risk of heat illness following exercise. This study compared the efficacy of five cooling techniques, hand immersion (HI), whole body fanning (WBF), an air cooled garment (ACG), a liquid cooled garment (LCG) and a phase change garment (PCG), against a natural cooling control condition (CON) over two periods between and following exercise bouts in 31 degrees C, 70%RH air. Nine males [age 22 (3) years; height 1.80 (0.04) m; mass 69.80 (7.10) kg] exercised on a treadmill at a maximal sustainable work intensity until rectal temperature (T (re)) reached 38.5 degrees C following which they underwent a resting recovery (0-15 min; COOL 1). They then recommenced exercise until T (re) again reached 38.5 degrees C and then undertook 30 min of cooling with (0-15 min; COOL 2A), and without face fanning (15-30 min; COOL 2B). Based on mean body temperature changes (COOL 1), WBF was most effective in extracting heat: CON 99 W; WBF: 235 W; PCG: 141 W; HI: 162 W; ACG: 101 W; LCG: 49 W) as a consequence of evaporating more sweat. Therefore, WBF represents a cheap and practical means of post-exercise cooling in hot, humid conditions in a sporting setting.

  15. Hot working alkali halides for laser window applications

    International Nuclear Information System (INIS)

    Koepke, B.G.; Anderson, R.H.; Stokes, R.J.

    1975-01-01

    The techniques used to hot work alkali halide crystals into laser window blanks are reviewed. From the point of view of high power laser window applications one of the materials with a high figure of merit is KCl. Thus the materials examined are KCl and alloys of KCl-KBr containing 5 mole percent KBr. The fabrication techniques include conventional and constrained press forging, isostatic press forging and hot rolling. Optical properties are paramount to the ultimate usefulness of these materials. Results on the optical properties of the hot worked material are included together with mechanical properties and microstructural data

  16. Hot-plasma decoupling condition for long-wavelength modes

    International Nuclear Information System (INIS)

    Berk, H.L.; Van Dam, J.W.; Spong, D.

    1982-10-01

    The stability of layer modes is analyzed for z-pinch and bumpy cylinder models. These modes are long wavelength across the layer and flute-like along the field line. The stability condition can be expressed in terms of the ratio of hot to core plasma density. It is shown that to achieve conditions close to the Nelson, Lee-Van Dam core beta limit, one needs a considerably smaller hot to core plasma density than is required to achieve stability at zero core beta

  17. Application of processing maps in the optimization of the parameters of a hot working process. Part 1. Theoretical review

    International Nuclear Information System (INIS)

    Al Omar, A.; Prado, J.M.

    1997-01-01

    The hot working processes constitute an important step in the manufacture of components for engineering applications. In the past, the mechanical processing have been used to impart a shape to the engineering materials. More recently, however, the hot working processes are used not only to achieve the required shape but also to impart desirable mechanical and microstructural characteristics by an adequate design of the thermomechanical process. The aim of the present paper is to summarize the general characteristics of the Dynamic Materials Model. In this model, the work piece material under hot working conditions is considered to be a dissipator of power. Also, the extreme principles of irreversible thermodynamics applied to large plastic flow are described to develop a continuum criterion capable to predict the metallurgical instabilities in a hot worked material. (Author) 22 refs

  18. Models and methods for hot spot safety work

    DEFF Research Database (Denmark)

    Vistisen, Dorte

    2002-01-01

    Despite the fact that millions DKK each year are spent on improving roadsafety in Denmark, funds for traffic safety are limited. It is therefore vital to spend the resources as effectively as possible. This thesis is concerned with the area of traffic safety denoted "hot spot safety work", which...... is the task of improving road safety through alterations of the geometrical and environmental characteristics of the existing road network. The presently applied models and methods in hot spot safety work on the Danish road network were developed about two decades ago, when data was more limited and software...... and statistical methods less developed. The purpose of this thesis is to contribute to improving "State of the art" in Denmark. Basis for the systematic hot spot safety work are the models describing the variation in accident counts on the road network. In the thesis hierarchical models disaggregated on time...

  19. Evaluation of advanced hot conditioning process for PHWRS

    International Nuclear Information System (INIS)

    Chandramohan, P.; Srinivasan, M.P.; Velmurugan, S.

    2015-01-01

    Hot-conditioning/hot functional test process is carried out to the PHT system of reactor before reactor going to critical/operational. The process is aimed in checking the component functionalities at high temperature and high pressure conditions, the process also checks/removes the suspended corrosion products in heat transport circuit. This process leads to formation of a passive or corrosion oxide film on the heat transport circuit surfaces which protects/mitigates the corrosion of the system circuits during the operation of plant. Major concerned alloy in the Primary Heat Transport (PHT) system of Indian PHWRs during the hot conditioning process and also during operation is the carbon steel due to its high corrosion. Hot-conditioning process mitigates the corrosion of carbon steel by the formation of iron oxide (Fe 3 O 4 ) as major oxide phase layer on the carbon steel surface with a typical thickness of 1.0 μm with particle size of 1μm after 336 h of process at 250 °C. But this passive oxide film thickness increase with time of operation of system with c.a. 10μm for 2.2 EFYP. The protectiveness of passive layer can be further enhanced by reducing the particle sizes in the passive film to nano meter range. The process can impact on the compactness of passive oxide layer with reduced pores in the oxide layer and properties of the nano nature oxide (transport properties) impacting the corrosion mitigation. The corrosion mitigation reduce the source term in the activated corrosion product generation. To achieve this a new process 'Advanced hot conditioning' was developed in water steam chemistry division, BARC for getting a passive oxide film with a lowered particle size in the passive film. The AHC process with 1g/L of PEG-8000 at 250 °C for 336 h showed a particle size <100 nm. The process was tested under the normal operating conditions as function of the time, the corrosion parameter like oxide film thickness, corrosion rate and metal ion

  20. Regularities in structure formation of magnesium-yttrium alloy of Mg-Y-Mn-Cd system in relation to temperature and hot working rate

    International Nuclear Information System (INIS)

    Ovechkin, B.I.; Miklina, N.V.; Blokhin, N.N.; Sorokin, A.F.

    1981-01-01

    Problems of the structure formation of magnesium-yttrium alloy of Mg-G-Mn-Cd system with 7.8 % G in a wide range of temperature-rate parameters of hot working are studied. On the basis of X-ray analysis results ascertained with metallographic and electron microscopic investigations, a diagram of structural states after hot working of Mg-G-Mn-Cd system alloy has been plotted. A change in grain size in relation to temperature-rate conditions of hot working

  1. The Effects of Simulated Wildland Firefighting Tasks on Core Temperature and Cognitive Function under Very Hot Conditions

    Directory of Open Access Journals (Sweden)

    F. Michael Williams-Bell

    2017-10-01

    Full Text Available Background: The severity of wildland fires is increasing due to continually hotter and drier summers. Firefighters are required to make life altering decisions on the fireground, which requires analytical thinking, problem solving, and situational awareness. This study aimed to determine the effects of very hot (45°C; HOT conditions on cognitive function following periods of simulated wildfire suppression work when compared to a temperate environment (18°C; CON.Methods: Ten male volunteer firefighters intermittently performed a simulated fireground task for 3 h in both the CON and HOT environments, with cognitive function tests (paired associates learning and spatial span assessed at baseline (cog 1 and during the final 20-min of each hour (cog 2, 3, and 4. Reaction time was also assessed at cog 1 and cog 4. Pre- and post- body mass were recorded, and core and skin temperature were measured continuously throughout the protocol.Results: There were no differences between the CON and HOT trials for any of the cognitive assessments, regardless of complexity. While core temperature reached 38.7°C in the HOT (compared to only 37.5°C in the CON; p < 0.01, core temperature declined during the cognitive assessments in both conditions (at a rate of −0.15 ± 0.20°C·hr−1 and −0.63 ± 0.12°C·hr−1 in the HOT and CON trial respectively. Firefighters also maintained their pre-exercise body mass in both conditions, indicating euhydration.Conclusions: It is likely that this maintenance of euhydration and the relative drop in core temperature experienced between physical work bouts was responsible for the preservation of firefighters' cognitive function in the present study.

  2. The minimum work required for air conditioning process

    International Nuclear Information System (INIS)

    Alhazmy, Majed M.

    2006-01-01

    This paper presents a theoretical analysis based on the second law of thermodynamics to estimate the minimum work required for the air conditioning process. The air conditioning process for hot and humid climates involves reducing air temperature and humidity. In the present analysis the inlet state is the state of the environment which has also been chosen as the dead state. The final state is the human thermal comfort fixed at 20 o C dry bulb temperature and 60% relative humidity. The general air conditioning process is represented by an equivalent path consisting of an isothermal dehumidification followed by a sensible cooling. An exergy analysis is performed on each process separately. Dehumidification is analyzed as a separation process of an ideal mixture of air and water vapor. The variations of the minimum work required for the air conditioning process with the ambient conditions is estimated and the ratio of the work needed for dehumidification to the total work needed to perform the entire process is presented. The effect of small variations in the final conditions on the minimum required work is evaluated. Tolerating a warmer or more humid final condition can be an easy solution to reduce the energy consumptions during critical load periods

  3. Heating, Ventilation, and Air Conditioning Design Strategy for a Hot-Humid Production Builder

    Energy Technology Data Exchange (ETDEWEB)

    Kerrigan, P. [Building Science Corporation, Somerville, MA (United States)

    2014-03-01

    Building Science Corporation (BSC) worked directly with the David Weekley Homes - Houston division to develop a cost-effective design for moving the HVAC system into conditioned space. In addition, BSC conducted energy analysis to calculate the most economical strategy for increasing the energy performance of future production houses in preparation for the upcoming code changes in 2015. This research project addressed the following questions: 1. What is the most cost effective, best performing and most easily replicable method of locating ducts inside conditioned space for a hot-humid production home builder that constructs one and two story single family detached residences? 2. What is a cost effective and practical method of achieving 50% source energy savings vs. the 2006 International Energy Conservation Code for a hot-humid production builder? 3. How accurate are the pre-construction whole house cost estimates compared to confirmed post construction actual cost?

  4. 46 CFR 176.710 - Inspection and testing prior to hot work.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Inspection and testing prior to hot work. 176.710... testing prior to hot work. (a) An inspection for flammable or combustible gases must be conducted by a... operations involving riveting, welding, burning, or other fire producing actions may be made aboard a vessel...

  5. 46 CFR 115.710 - Inspection and testing prior to hot work.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Inspection and testing prior to hot work. 115.710... AND CERTIFICATION Repairs and Alterations § 115.710 Inspection and testing prior to hot work. (a) An... involving riveting, welding, burning, or other fire producing actions may be made aboard a vessel: (1...

  6. Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

    International Nuclear Information System (INIS)

    Kim, D.S.; Infante Ferreira, C.A.

    2009-01-01

    A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

  7. On the relationship between tropospheric conditions and widespread hot days in Iran

    Science.gov (United States)

    Asakereh, Hossein; Shadman, Hassan

    2018-01-01

    The present study investigated how the tropospheric conditions relate to the occurrence of widespread hot days (WHD) in Iran using the data of maximum daily temperature and other tropospheric variables. To better understand the tropospheric conditions during WHD, different patterns of tropospheric circulation were examined systematically. Four tropospheric types were identified based on sea level pressure (SLP). SLP, 500 hPa height, anomaly patterns, and warm advection maps were constructed for typical days of each group. The tropospheric conditions associated with hot days occurred simultaneously with a low-pressure system at sea level, a ridge at middle troposphere over Iran, and a pronounced trough over the Mediterranean Sea at 500 hPa. These conditions caused air mass from subtropical regions toward Iran. That is, northward, northeastward, and even eastward winds injected heat with warm origins toward the country. Hot days compounded by drought conditions have affected many parts of the country in different ways such as decrease in the agricultural products in numerous areas and significant discharge reduction in many rivers. The society is also very likely to face considerable challenges to cope with hot days. The findings of the study can be utilized in climate modeling and climate prediction of hot days in the country. Accordingly, water and electricity consumption can be planned with further precision and water consumption can be managed in crises.

  8. Structural Safety Analysis of Openable Working Table in ACP Hot Cell for Spent Fuel Treatment

    International Nuclear Information System (INIS)

    Kwon, Ki Chan; Ku, Jeong Hoe; Lee, Eun Pyo; Choung, Won Myung; You, Gil Sung; Lee, Won Kyung; Cho, IL Je; Kuk, Dong Hak

    2006-01-01

    A demonstration facility for advanced spent fuel conditioning process (ACP) is under construction in KAERI. In this hot cell facility, all process equipment and materials are taken in and out only through the rear door. The working table in front of the process rear door is specially designed to be openable for the efficient use of the space. This paper presents the structural safety analysis of the openable working table, for the normal operational load condition and accidental drop condition of heavy object. Both cases are investigated through static and dynamic finite element analyses. The analysis results show that structural safety of the working table is sufficiently assured and the working table is not collapsed even when an object of 500 kg is dropped from the height of 50 cm.

  9. ATMOSPHERIC CIRCULATION OF HOT JUPITERS: INSENSITIVITY TO INITIAL CONDITIONS

    International Nuclear Information System (INIS)

    Liu Beibei; Showman, Adam P.

    2013-01-01

    The ongoing characterization of hot Jupiters has motivated a variety of circulation models of their atmospheres. Such models must be integrated starting from an assumed initial state, which is typically taken to be a wind-free, rest state. Here, we investigate the sensitivity of hot-Jupiter atmospheric circulation to initial conditions with shallow-water models and full three-dimensional models. Those models are initialized with zonal jets, and we explore a variety of different initial jet profiles. We demonstrate that, in both classes of models, the final, equilibrated state is independent of initial condition—as long as frictional drag near the bottom of the domain and/or interaction with a specified planetary interior are included so that the atmosphere can adjust angular momentum over time relative to the interior. When such mechanisms are included, otherwise identical models initialized with vastly different initial conditions all converge to the same statistical steady state. In some cases, the models exhibit modest time variability; this variability results in random fluctuations about the statistical steady state, but we emphasize that, even in these cases, the statistical steady state itself does not depend on initial conditions. Although the outcome of hot-Jupiter circulation models depend on details of the radiative forcing and frictional drag, aspects of which remain uncertain, we conclude that the specification of initial conditions is not a source of uncertainty, at least over the parameter range explored in most current models.

  10. The hot working characteristics of a boron bearing and a conventional low carbon steel

    International Nuclear Information System (INIS)

    Stumpf, Waldo; Banks, Kevin

    2006-01-01

    Constitutive hot working constants were determined for an 11 ppm boron low carbon strip steel and compared from 875 to 1140 deg. C and strain rates of 0.001-2.5 s -1 to a high nitrogen low carbon strip steel. The boron steel showed a different hot working behaviour than the conventional steel with the steady state flow stress about 50-60% higher, the peak strain more than 50% higher and the eventual ferrite grain size about 40% smaller, if compared at the same temperature compensated strain rates or Z values. This difference persisted where the soaking temperature before compression was varied between 1140 and 1250 deg. C, proving that undissolved AlN in the boron-bearing steel was not responsible. With systematically varied linear cooling rates after hot working, the final ferrite grain size in the boron steel is finer and is independent of the two Z values applied during hot working. Retarded softening by dynamic recrystallisation during hot working in the boron containing steel is probably caused by boron solute drag of moving grain boundaries

  11. Heating, Ventilation, and Air Conditioning Design Strategy for a Hot-Humid Production Builder

    Energy Technology Data Exchange (ETDEWEB)

    Kerrigan, P. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-03-01

    BSC worked directly with the David Weekley Homes - Houston division to redesign three floor plans in order to locate the HVAC system in conditioned space. The purpose of this project is to develop a cost effective design for moving the HVAC system into conditioned space. In addition, BSC conducted energy analysis to calculate the most economical strategy for increasing the energy performance of future production houses. This is in preparation for the upcoming code changes in 2015. The builder wishes to develop an upgrade package that will allow for a seamless transition to the new code mandate. The following research questions were addressed by this research project: 1. What is the most cost effective, best performing and most easily replicable method of locating ducts inside conditioned space for a hot-humid production home builder that constructs one and two story single family detached residences? 2. What is a cost effective and practical method of achieving 50% source energy savings vs. the 2006 International Energy Conservation Code for a hot-humid production builder? 3. How accurate are the pre-construction whole house cost estimates compared to confirmed post construction actual cost? BSC and the builder developed a duct design strategy that employs a system of dropped ceilings and attic coffers for moving the ductwork from the vented attic to conditioned space. The furnace has been moved to either a mechanical closet in the conditioned living space or a coffered space in the attic.

  12. A temperature dependent cyclic plasticity model for hot work tool steel including particle coarsening

    Science.gov (United States)

    Jilg, Andreas; Seifert, Thomas

    2018-05-01

    Hot work tools are subjected to complex thermal and mechanical loads during hot forming processes. Locally, the stresses can exceed the material's yield strength in highly loaded areas as e.g. in small radii in die cavities. To sustain the high loads, the hot forming tools are typically made of martensitic hot work steels. While temperatures for annealing of the tool steels usually lie in the range between 400 and 600 °C, the steels may experience even higher temperatures during hot forming, resulting in softening of the material due to coarsening of strengthening particles. In this paper, a temperature dependent cyclic plasticity model for the martensitic hot work tool steel 1.2367 (X38CrMoV5-3) is presented that includes softening due to particle coarsening and that can be applied in finite-element calculations to assess the effect of softening on the thermomechanical fatigue life of hot work tools. To this end, a kinetic model for the evolution of the mean size of secondary carbides based on Ostwald ripening is coupled with a cyclic plasticity model with kinematic hardening. Mechanism-based relations are developed to describe the dependency of the mechanical properties on carbide size and temperature. The material properties of the mechanical and kinetic model are determined on the basis of tempering hardness curves as well as monotonic and cyclic tests.

  13. Calculation of recovery plasticity in multistage hot forging under isothermal conditions.

    Science.gov (United States)

    Zhbankov, Iaroslav G; Perig, Alexander V; Aliieva, Leila I

    2016-01-01

    A widely used method for hot forming steels and alloys, especially heavy forging, is the process of multistage forging with pauses between stages. The well-known effect which accompanies multistage hot forging is metal plasticity recovery in comparison with monotonic deformation. A method which takes into consideration the recovery of plasticity in pauses between hot deformations of a billet under isothermal conditions is proposed. This method allows the prediction of billet forming limits as a function of deformation during the forging stage and the duration of the pause between the stages. This method takes into account the duration of pauses between deformations and the magnitude of subdivided deformations. A hot isothermal upsetting process with pauses was calculated by the proposed method. Results of the calculations have been confirmed with experimental data.

  14. Hot deformation behavior and hot working characteristic of Nickel-base electron beam weldments

    International Nuclear Information System (INIS)

    Ning, Yongquan; Yao, Zekun; Guo, Hongzhen; Fu, M.W.

    2014-01-01

    Highlights: • The Hot deformation behavior of electron beam (EB) Nickel-base weldments was investigated. • The constitutive equation represented by temperature, strain rate and true strain was developed. • Processing map approach was adopted to optimize the hot forging process of EB weldments. • True strain has a great effect on the efficiency of power dissipation (η). -- Abstract: The electron beam welding (EBW) of Nickel-base superalloys was conducted, and the cylindrical compression specimens were machined from the central part of the electron beam (EB) weldments. The hot deformation behavior of EB weldments was investigated at the temperature of 960–1140 °C and the strain rate of 0.001–1.0 s −1 . The apparent activation energy of deformation was calculated to be 400 kJ/mol, and the constitutive equation that describes the flow stress as a function of strain rate and deformation temperature was proposed for modeling of the hot deformation process of EB weldments. The processing map approach was adopted to investigate the deformation mechanisms during the hot plastic deformation and to optimize the processing parameters of EB weldments. It is found that the true strain has a significant effect on the efficiency of power dissipation (η). The η value in the safe processing domain (1140 °C, 1.0 s −1 ) increases from 0.32 to 0.55. In the unsafe processing domain (1080 °C, 0.001 s −1 ), however, the η value greatly decreases with the increase of strain. When the strain is 0.40, the efficiency of power dissipation becomes negative. The flow instability is predicted to occur since the instability parameter ξ(ε) becomes negative. The hot deformation of EB weldments can be carried out safely in the domain with the strain rate range of 0.1–1.0 s −1 and the temperature range of 960–1140 °C. When the height reduction is about 50%, the optimum processing condition is (T opi : 1140 °C, ε opi : 1.0 s −1 ) with the peak efficiency of 0

  15. Hot deformation behavior and hot working characteristic of Nickel-base electron beam weldments

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Yongquan, E-mail: ningke521@163.com [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Yao, Zekun; Guo, Hongzhen [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Fu, M.W. [Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

    2014-01-25

    Highlights: • The Hot deformation behavior of electron beam (EB) Nickel-base weldments was investigated. • The constitutive equation represented by temperature, strain rate and true strain was developed. • Processing map approach was adopted to optimize the hot forging process of EB weldments. • True strain has a great effect on the efficiency of power dissipation (η). -- Abstract: The electron beam welding (EBW) of Nickel-base superalloys was conducted, and the cylindrical compression specimens were machined from the central part of the electron beam (EB) weldments. The hot deformation behavior of EB weldments was investigated at the temperature of 960–1140 °C and the strain rate of 0.001–1.0 s{sup −1}. The apparent activation energy of deformation was calculated to be 400 kJ/mol, and the constitutive equation that describes the flow stress as a function of strain rate and deformation temperature was proposed for modeling of the hot deformation process of EB weldments. The processing map approach was adopted to investigate the deformation mechanisms during the hot plastic deformation and to optimize the processing parameters of EB weldments. It is found that the true strain has a significant effect on the efficiency of power dissipation (η). The η value in the safe processing domain (1140 °C, 1.0 s{sup −1}) increases from 0.32 to 0.55. In the unsafe processing domain (1080 °C, 0.001 s{sup −1}), however, the η value greatly decreases with the increase of strain. When the strain is 0.40, the efficiency of power dissipation becomes negative. The flow instability is predicted to occur since the instability parameter ξ(ε) becomes negative. The hot deformation of EB weldments can be carried out safely in the domain with the strain rate range of 0.1–1.0 s{sup −1} and the temperature range of 960–1140 °C. When the height reduction is about 50%, the optimum processing condition is (T{sub opi}: 1140 °C, ε{sub opi}: 1.0 s{sup −1}) with

  16. Hot working effect on austenite transformations in structural steel in continuous cooling

    International Nuclear Information System (INIS)

    Zajmovskij, V.A.; Kisteh, N.V.; Samedov, O.V.

    1979-01-01

    Austenite transformations in 40, 40Kh, 40KhN and 40KhNMA steels under hot working at 900 deg C with 20% reduction degree and continuous cooling with 1,7-16 0 /s are investigated. Changing of cooling rate in various ways affects the temperature range of austenite transformation in pearlite and bainite regions. Regulating the cooling rate after hot working one can essentially change the impact strength and steel ductility as a result of high temperature thermomechanical treatment effect

  17. The development of a mobile hot cell facility for the conditioning of spent high activity radioactive sources (SHARS)

    International Nuclear Information System (INIS)

    Liebenberg, G.R.; Al-Mughrabi, M.

    2008-01-01

    The International Atomic Energy Agency (IAEA) Waste Technology Section with additional support from the U.S. National Nuclear Security Agency (NNSA) through the IAEA Nuclear Security Fund has funded the design, fabrication, evaluation, and testing of a portable hot cell intended to address the problem of disused SHARS in obsolete irradiation devices such as teletherapy heads and dry irradiators. The project is initially targeting the African continent but expected soon to expand to Latin America and Asia. This hot cell would allow source removal, characterization, consolidation, repackaging in modern storage shields, and secure storage of high risk SHARS at single sites in each IAEA Member State. The mobile hot cell and related equipment is transported in two shipping containers to a specific country where the following process takes place: 1-) Assembly of hot cell; 2-) Removal of SHARS from working shields, encapsulation into a stainless steel capsule and placement into a long term storage shield; 3-) Conditioning of any other spent sources the country may require; 4-) Dismantling of the hot cell; 5-) Shipping equipment out of country. The operation in a specific country is planned to be executed over a three week period. This presentation will discuss the development of the mobile hot cell facility as well as the demonstration of the state of readiness of the system for manipulation of SHARS and the planned execution of the conditioning operations. As a result of this project, excess SHARS could be managed safely and securely and possibly be more easily repatriated to their country of origin for appropriate final disposition. (author)

  18. A comparison of cytokine responses during prolonged cycling in normal and hot environmental conditions

    Directory of Open Access Journals (Sweden)

    Ludmila M Cosio-Lima

    2011-01-01

    Full Text Available Ludmila M Cosio-Lima, Bhargav V Desai, Petra B Schuler, Lesley Keck, Logan ScheelerDepartment of Health, Leisure, and Exercise Science, University of West Florida, Pensacola, FL, USAPurpose: Components of immune function are affected by physical activity in an adverse environment. The purpose of this study was to compare plasma differences in inflammatory cytokines including tumor necrosis factor α (TNF-α and interleukin 6 (IL-6, in addition to the stress hormone cortisol, during prolonged cycling under normal and hot environmental conditions in elite cyclists.Methods and design: Six trained elite male cyclists (27 ± 8 years; 75.5 ± 4 kg; maximum oxygen uptake [VO2max] = 66 ± 6 mL/kg/min, mean ± SD. The cyclists biked for 2.5 h at their prescribed 60% maximum exercise workload (Wmax or 75% VO2max either in an environmental chamber set at 15°C and 40% relative humidity (NEUTRAL or at 35°C and 40% relative humidity (HOT. The cyclists were given 4 mL of water/kg body weight every 15 min under both conditions.Results: Total cortisol concentrations were elevated (P < 0.05 immediately postexercise and 12 h postexercise in both the NEUTRAL and HOT conditions. TNF-α concentrations were only significantly (P = 0.045 elevated postexercise in HOT conditions. During the HOT conditions, a significant (P = 0.006 and 0.007, respectively difference in IL-6 was seen immediately after and 12 h postexercise. During the NEUTRAL condition, IL-6 was only significantly elevated postexercise (P < 0.05.Conclusions: Heat exposure during a long bout of exercise is sufficient to elicit stress response in elite cyclists. However, the degree of release of anti-inflammatory and proinflammatory cytokines might be related to several factors that include the athlete’s fitness level, hydration status, exercise intensity, and length of exposure to hot environments.Keywords: cytokines, inflammation, heat, exercise, performance 

  19. Shield wall evaluation of hot cell facility for advanced spent fuel conditioning process

    International Nuclear Information System (INIS)

    Cho, I. J.; Kuk, D. H.; Ko, J. H.; Jung, W. M.; Yoo, G. S.; Lee, E. P.; Park, S. W.

    2002-01-01

    The future hot cell is located in the Irradiated Material Experiment Facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI). It is β-γ type hot cell that was constructed on the base floor in IMEF building for irradiated material testing. And this hot cell will be used for carrying out the Advanced spent fuel Conditioning Process (ACP). The radiation shielding capability of hot cell should be sufficient to meet the radiation dose requirements in the related regulations. Because the radioactive sources of ACP are expected to be higher than radioactive sources of IMEF design criteria, the future hot cell in current status is unsatisfactory to hot test of ACP. So the shielding analysis of the future hot cell is performed to evaluate shielding ability of concrete shield wall. The shielding analysis included (a) identification of ACP source term; (b) photon source spectrum; (c) shielding analysis by QADS and MCNP-4C; and (d) enhancement of concrete shield wall. In this research, dose rates are obtained according to ACP source, geometry and hot cell shield wall thickness. And the evaluation and reinforcement thickness of the shield wall about future hot cell are concluded

  20. Metallurgical analysis of spalled work roll of hot strip mill

    International Nuclear Information System (INIS)

    Khan, M.M.; Khan, M.A.

    1993-01-01

    In this study failure analysis of four work roll of the Hot Strip Mill is carried out. The microstructure is correlated with the chemical composition of shell and roll-life. It was concluded that for the longer service of the roll, cementite, graphite and martensite should be balanced (as per working requirement of the mill). (author)

  1. An Incremental Physically-Based Model of P91 Steel Flow Behaviour for the Numerical Analysis of Hot-Working Processes

    Directory of Open Access Journals (Sweden)

    Alberto Murillo-Marrodán

    2018-04-01

    Full Text Available This paper is aimed at modelling the flow behaviour of P91 steel at high temperature and a wide range of strain rates for constant and also variable strain-rate deformation conditions, such as those in real hot-working processes. For this purpose, an incremental physically-based model is proposed for the P91 steel flow behavior. This formulation considers the effects of dynamic recovery (DRV and dynamic recrystallization (DRX on the mechanical properties of the material, using only the flow stress, strain rate and temperature as state variables and not the accumulated strain. Therefore, it reproduces accurately the flow stress, work hardening and work softening not only under constant, but also under transient deformation conditions. To accomplish this study, the material is characterised experimentally by means of uniaxial compression tests, conducted at a temperature range of 900–1270 °C and at strain rates in the range of 0.005–10 s−1. Finally, the proposed model is implemented in commercial finite element (FE software to provide evidence of the performance of the proposed formulation. The experimental compression tests are simulated using the novel model and the well-known Hansel–Spittel formulation. In conclusion, the incremental physically-based model shows accurate results when work softening is present, especially under variable strain-rate deformation conditions. Hence, the present formulation is appropriate for the simulation of the hot-working processes typically conducted at industrial scale.

  2. Study of the microstructure evolution of ferritic stainless ODS steels during hot working

    International Nuclear Information System (INIS)

    Karch, Abdellatif

    2014-01-01

    The production of ODS steels involves a powder consolidation step usually using the hot extrusion (HE) process. The anisotropic properties of extruded materials, especially in the ODS ferritic grades (≥wt%12Cr), need a better understanding of the metallurgical phenomena which may occur during HE and lead to the observed microstructure. The hot working behavior of these materials is of particular interest. The methodology of this work includes the microstructure analysis after interrupted hot extrusion, hot torsion and hot compression (1000-1200 C) tests of ferritic steels with 14%Cr and different amounts in Ti and Y 2 O 3 . The microstructure evolution during hot extrusion process is associated with continuous dynamic recrystallization (CDRX). It leads to the creation of new grains by the formation of low angle boundaries, and then the increase of their misorientation under plastic deformation. The investigations highlight also the role of precipitation on the kinetics of this mechanism; it remains incomplete in the presence of fine and dense nano-precipitates. After hot deformation in torsion and compression, it is noticed that both precipitates and temperature deformation have a significant impact on the deformation mechanisms and microstructure evolution. Indeed, the CDRX is dominant when temperature and amount of reinforcement are limited. However, when they are increased, limited microstructure evolution is observed. In this case, the results are interpreted through a mechanism of strain accommodation at grain boundaries, with low dislocation activity in the bulk of the grains. (author) [fr

  3. Hot workability of aluminium alloys

    International Nuclear Information System (INIS)

    Yoo, Yeon Chul; Oh, Kyung Jin

    1986-01-01

    Hot Workability of aluminium alloys, 2024, 6061 and 7075, has been studied by hot torsion tests at temperatures from 320 to 515 deg C and at strain rates from 1.26 x 10 -3 to 5.71 x 10 -3 sec -1 . Hot working condition of these aluminium alloys was determined quantitatively from the constitutive equations obtained from flow stress curves in torsion. Experimental data of the logarith of the Zener-Hollomonn parameter showed good linear relationships to the logarith of sinh(ασ-bar)

  4. Hot working mechanisms and texture development in Mg-3Sn-2Ca-0.4Al alloy

    International Nuclear Information System (INIS)

    Dharmendra, C.; Rao, K.P.; Prasad, Y.V.R.K.; Hort, N.; Kainer, K.U.

    2012-01-01

    Hot deformation mechanisms in Mg-3Sn-2Ca (TX32) alloy containing 0.4% Al are evaluated in the temperature and strain rate ranges of 300–500 °C and 0.0003–10 s −1 using processing map and kinetic analysis. The evolution of microstructure and texture during high temperature compression of the alloy has been studied using an electron back scatter diffraction (EBSD) technique. The processing map for hot working revealed two domains of dynamic recrystallization (DRX) occurring in the temperature and strain rate ranges of: (1) 300–360 °C and 0.0003–0.001 s −1 and (2) 400–500 °C and 0.005–0.7 s −1 , which are the two safe hot workability windows for this alloy. A regime of flow instability occurs at higher strain rates and lower temperatures where adiabatic shear banding and flow localization are the microstructural manifestations. The onset of DRX during compression at lower temperatures and strain rates (Domain 1) resulted in a fine, partially recrystallized and necklaced grain microstructure along with a texture where the basal poles are spread along 30° from the compression direction. Specimens deformed at temperatures higher than 450 °C (Domain 2) resulted in a fully recrystallized microstructure and an almost random crystallographic texture, which was attributed to the significant occurrence of pyramidal slip and associated cross-slip. -- Highlights: ► Processing map revealed two DRX domains for hot working of Mg-3Sn-2Ca-0.4Al alloy. ► The alloy exhibited flow instability at lower temperatures and higher strain rates. ► Activation energy values for deformation are high due to the back stress. ► Basal poles spread around 30° to the compression axis for Domain 1 peak condition. ► Texture got randomized at high temperature and strain rate conditions in Domain 2.

  5. Hot working mechanisms and texture development in Mg-3Sn-2Ca-0.4Al alloy

    Energy Technology Data Exchange (ETDEWEB)

    Dharmendra, C. [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR (China); Rao, K.P., E-mail: mekprao@cityu.edu.hk [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR (China); Prasad, Y.V.R.K. [Processingmaps.com (formerly at City University of Hong Kong) (Hong Kong); Hort, N.; Kainer, K.U. [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Magnesium Innovation Centre, Max-Planck-Strasse 1, Geesthact 21502 (Germany)

    2012-10-15

    Hot deformation mechanisms in Mg-3Sn-2Ca (TX32) alloy containing 0.4% Al are evaluated in the temperature and strain rate ranges of 300-500 Degree-Sign C and 0.0003-10 s{sup -1} using processing map and kinetic analysis. The evolution of microstructure and texture during high temperature compression of the alloy has been studied using an electron back scatter diffraction (EBSD) technique. The processing map for hot working revealed two domains of dynamic recrystallization (DRX) occurring in the temperature and strain rate ranges of: (1) 300-360 Degree-Sign C and 0.0003-0.001 s{sup -1} and (2) 400-500 Degree-Sign C and 0.005-0.7 s{sup -1}, which are the two safe hot workability windows for this alloy. A regime of flow instability occurs at higher strain rates and lower temperatures where adiabatic shear banding and flow localization are the microstructural manifestations. The onset of DRX during compression at lower temperatures and strain rates (Domain 1) resulted in a fine, partially recrystallized and necklaced grain microstructure along with a texture where the basal poles are spread along 30 Degree-Sign from the compression direction. Specimens deformed at temperatures higher than 450 Degree-Sign C (Domain 2) resulted in a fully recrystallized microstructure and an almost random crystallographic texture, which was attributed to the significant occurrence of pyramidal slip and associated cross-slip. -- Highlights: Black-Right-Pointing-Pointer Processing map revealed two DRX domains for hot working of Mg-3Sn-2Ca-0.4Al alloy. Black-Right-Pointing-Pointer The alloy exhibited flow instability at lower temperatures and higher strain rates. Black-Right-Pointing-Pointer Activation energy values for deformation are high due to the back stress. Black-Right-Pointing-Pointer Basal poles spread around 30 Degree-Sign to the compression axis for Domain 1 peak condition. Black-Right-Pointing-Pointer Texture got randomized at high temperature and strain rate conditions in

  6. WESF hot cells waste minimization criteria hot cells window seals evaluation

    International Nuclear Information System (INIS)

    Walterskirchen, K.M.

    1997-01-01

    WESF will decouple from B Plant in the near future. WESF is attempting to minimize the contaminated solid waste in their hot cells and utilize B Plant to receive the waste before decoupling. WESF wishes to determine the minimum amount of contaminated waste that must be removed in order to allow minimum maintenance of the hot cells when they are placed in ''laid-up'' configuration. The remaining waste should not cause unacceptable window seal deterioration for the remaining life of the hot cells. This report investigates and analyzes the seal conditions and hot cell history and concludes that WESF should remove existing point sources, replace cerium window seals in F-Cell and refurbish all leaded windows (except for A-Cell). Work should be accomplished as soon as possible and at least within the next three years

  7. Physiological characteristics under the influence of heat stress working in the hot environment, (4)

    International Nuclear Information System (INIS)

    Nagasaka, Akihiko; Yoshino, Kenji; Takano, Ken-ichi

    1987-01-01

    There is a possibility that physical and mental stress appears under hot environmental condition for the cause of wearing protection suits on reactor maintenance work. It is important to reduce heat stress rapidly and effectively. This paper mentioned following about the results of static state and simulation work done by testees with or without protection suits under 25 kinds of temperatures and wind velocities in a artificial climate chamber. (1) the correlation between ambient temperatures or wind velocities and subjective symptoms without protection suits. (2) the correlation between ambient temperatures or wind velocities and skin temperatures without protection suits. (3) investigation of the parts of body affecting subjective symptoms. (4) the correlation between ambient temperatures or wind velocities and skin temperatures at working with protection suits. (5) working out countermeasures of recovery from heat stress with the index of skin temperatures and subjective symptoms. (author)

  8. Heat Treatment Optimization and Properties Correlation for H11-Type Hot-Work Tool Steel

    Science.gov (United States)

    Podgornik, B.; Puš, G.; Žužek, B.; Leskovšek, V.; Godec, M.

    2018-02-01

    The aim of this research was to determine the effect of vacuum-heat-treatment process parameters on the material properties and their correlations for low-Si-content AISI H11-type hot-work tool steel using a single Circumferentially Notched and fatigue Pre-cracked Tensile Bar (CNPTB) test specimen. The work was also focused on the potential of the proposed approach for designing advanced tempering diagrams and optimizing the vacuum heat treatment and design of forming tools. The results show that the CNPTB specimen allows a simultaneous determination and correlation of multiple properties for hot-work tool steels, with the compression and bending strength both increasing with hardness, and the strain-hardening exponent and bending strain increasing with the fracture toughness. On the other hand, the best machinability and surface quality of the hardened hot-work tool steel are obtained for hardness values between 46 and 50 HRC and a fracture toughness below 60 MPa√m.

  9. Improved running performance in hot humid conditions following whole body precooling.

    Science.gov (United States)

    Booth, J; Marino, F; Ward, J J

    1997-07-01

    On two separate occasions, eight subjects controlled speed to run the greatest distance possible in 30 min in a hot, humid environment (ambient temperature 32 degrees C, relative humidity 60%). For the experimental test (precooling), exercise was preceeded by cold-water immersion. Precooling increased the distance run by 304 +/- 166 m (P body temperature decreased from 36.5 +/- 0.1 degrees C to 33.8 +/- 0.2 degrees C following precooling (P body sweating are not different between tests. In conclusion, water immersion precooling increased exercise endurance in hot, humid conditions with an enhanced rate of heat storage and decreased thermoregulatory strain.

  10. Semi-Supervised Transductive Hot Spot Predictor Working on Multiple Assumptions

    KAUST Repository

    Wang, Jim Jing-Yan

    2014-05-23

    Protein-protein interactions are critically dependent on just a few residues (“hot spots”) at the interfaces. Hot spots make a dominant contribution to the binding free energy and if mutated they can disrupt the interaction. As mutagenesis studies require significant experimental efforts, there exists a need for accurate and reliable computational hot spot prediction methods. Compared to the supervised hot spot prediction algorithms, the semi-supervised prediction methods can take into consideration both the labeled and unlabeled residues in the dataset during the prediction procedure. The transductive support vector machine has been utilized for this task and demonstrated a better prediction performance. To the best of our knowledge, however, none of the transductive semi-supervised algorithms takes all the three semisupervised assumptions, i.e., smoothness, cluster and manifold assumptions, together into account during learning. In this paper, we propose a novel semi-supervised method for hot spot residue prediction, by considering all the three semisupervised assumptions using nonlinear models. Our algorithm, IterPropMCS, works in an iterative manner. In each iteration, the algorithm first propagates the labels of the labeled residues to the unlabeled ones, along the shortest path between them on a graph, assuming that they lie on a nonlinear manifold. Then it selects the most confident residues as the labeled ones for the next iteration, according to the cluster and smoothness criteria, which is implemented by a nonlinear density estimator. Experiments on a benchmark dataset, using protein structure-based features, demonstrate that our approach is effective in predicting hot spots and compares favorably to other available methods. The results also show that our method outperforms the state-of-the-art transductive learning methods.

  11. Basic design and construction of a mobile hot cell for the conditioning of spent high activity radioactive sources

    International Nuclear Information System (INIS)

    An Hongxiang; Fan Zhiwen; Al-Mughrabi, M.

    2011-01-01

    The conditioning of spent high activity radioactive sources is one important step in sealed radioactive sources management strategies. Based on the practice on the designing of the immobilized hot cell, the handling of the sealed radioactive sources, and the reference of the mobile hot cell constructed in South Africa, SHARS conditioning process and the basic design of a mobile hot cell is developed. The mobile hot cell has been constructed and the tests including the cold test of the SRS conditioning, the hot cell assemble and disassemble and SRS recovery were done. The shielding capacity were tested by 3.8 x 10 13 Bq cobalt-60 sources and the dose rate of the equipment surface, below 2 m, is less than 0.016 mSv/h. It is proved that the designing requirement is meet and the function of the equipment is good. (authors)

  12. Work organisation, technology and working conditions

    OpenAIRE

    Dhondt, S.; Kraan, K.; Sloten, G. van

    2002-01-01

    The personal computer, computer networks and the Internet have brought the Union into the Information Age. These technological changes have inevitably led to changes in the work environment and the quality of working conditions. For the third time, the European Foundation for the Improvement of Living and Working Conditions has carried out a questionnaire-based survey on working conditions throughout the European Union, covering all Member States. Previous surveys were carried out in 1991 and...

  13. Importance of Electrode Hot-Pressing Conditions for the Catalyst Performance of Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Dhiman, Rajnish; Larsen, Mikkel Juul

    2015-01-01

    The catalyst performance in a proton exchange membrane fuel cell (PEMFC) depends on not only the choice of materials, but also on the electrode structure and in particular on the interface between the components. In this work, we demonstrate that the hot-pressing conditions used during electrode...... lamination have a great influence on the catalyst properties of a low-temperature PEMFC, especially on its durability. Lamination pressure, temperature and duration were systematically studied in relation to the electrochemical surface area, platinum dissolution, platinum particle size and electrode surface...

  14. Safety evaluation report of hot cell facilities for demonstration of advanced spent fuel conditioning process

    International Nuclear Information System (INIS)

    You, Gil Sung; Choung, W. M.; Ku, J. H.; Cho, I. J.; Kook, D. H.; Park, S. W.; Bek, S. Y.; Lee, E. P.

    2004-10-01

    The advanced spent fuel conditioning process(ACP) proposed to reduce the overall volume of the PWR spent fuel and improve safety and economy of the long-term storage of spent fuel. In the next phase(2004∼2006), the hot test will be carried out for verification of the ACP in a laboratory scale. For the hot test, the hot cell facilities of α- type and auxiliary facilities are required essentially for safe handling of high radioactive materials. As the hot cell facilities for demonstration of the ACP, a existing hot cell of β- type will be refurbished to minimize construction expenditures of hot cell facility. Up to now, the detail design of hot cell facilities and process were completed, and the safety analysis was performed to substantiate secure of conservative safety. The design data were submitted for licensing which was necessary for construction and operation of hot cell facilities. The safety investigation of KINS on hot cell facilities was completed, and the license for construction and operation of hot cell facilities was acquired already from MOST. In this report, the safety analysis report submitted to KINS was summarized. And also, the questionnaires issued from KINS and answers of KAERI in process of safety investigation were described in detail

  15. The impact of sustained hot weather on risk of acute work-related injury in Melbourne, Australia.

    Science.gov (United States)

    McInnes, Judith Anne; MacFarlane, Ewan M; Sim, Malcolm R; Smith, Peter

    2018-02-01

    It has been reported that weather-related high ambient temperature is associated with an increased risk of work-related injury. Understanding this relationship is important because work-related injuries are a major public health problem, and because projected climate changes will potentially expose workers to hot days, including consecutive hot days, more often. The aim of this study was to quantify the impact of exposure to sustained periods of hot weather on work-related injury risk for workers in Melbourne, Australia. A time-stratified case crossover study design was utilised to examine the association between two and three consecutive days and two and three consecutive nights of hot weather and the risk of work-related injury, using definitions of hot weather ranging from the 60th to the 95th percentile of daily maximum and minimum temperatures for the Melbourne metropolitan area, 2002-2012. Workers' compensation claim data was used to identify cases of acute work-related injury. Overall, two and three consecutive days of hot weather were associated with an increased risk of injury, with this effect becoming apparent at a daily maximum temperature of 27.6 °C (70th percentile). Three consecutive days of high but not extreme temperatures were associated with the strongest effect, with a 15% increased risk of injury (odds ratio 1.15, 95% confidence interval 1.01-1.30) observed when daily maximum temperature was ≥33.3 °C (90th percentile) for three consecutive days, compared to when it was not. At a threshold of 35.5 °C (95th percentile), there was no significant association between temperature and injury for either two or three consecutive days of heat. These findings suggest that warnings to minimise harm to workers from hot weather should be given, and prevention protocol initiated, when consecutive warm days of temperatures lower than extreme heat temperatures are forecast, and well before the upper ranges of ambient daytime temperatures are reached.

  16. The impact of sustained hot weather on risk of acute work-related injury in Melbourne, Australia

    Science.gov (United States)

    McInnes, Judith Anne; MacFarlane, Ewan M.; Sim, Malcolm R.; Smith, Peter

    2018-02-01

    It has been reported that weather-related high ambient temperature is associated with an increased risk of work-related injury. Understanding this relationship is important because work-related injuries are a major public health problem, and because projected climate changes will potentially expose workers to hot days, including consecutive hot days, more often. The aim of this study was to quantify the impact of exposure to sustained periods of hot weather on work-related injury risk for workers in Melbourne, Australia. A time-stratified case crossover study design was utilised to examine the association between two and three consecutive days and two and three consecutive nights of hot weather and the risk of work-related injury, using definitions of hot weather ranging from the 60th to the 95th percentile of daily maximum and minimum temperatures for the Melbourne metropolitan area, 2002-2012. Workers' compensation claim data was used to identify cases of acute work-related injury. Overall, two and three consecutive days of hot weather were associated with an increased risk of injury, with this effect becoming apparent at a daily maximum temperature of 27.6 °C (70th percentile). Three consecutive days of high but not extreme temperatures were associated with the strongest effect, with a 15% increased risk of injury (odds ratio 1.15, 95% confidence interval 1.01-1.30) observed when daily maximum temperature was ≥33.3 °C (90th percentile) for three consecutive days, compared to when it was not. At a threshold of 35.5 °C (95th percentile), there was no significant association between temperature and injury for either two or three consecutive days of heat. These findings suggest that warnings to minimise harm to workers from hot weather should be given, and prevention protocol initiated, when consecutive warm days of temperatures lower than extreme heat temperatures are forecast, and well before the upper ranges of ambient daytime temperatures are reached.

  17. Simplified numerical simulation of hot channel in sodium cooled reactor

    International Nuclear Information System (INIS)

    Fonseca, F. de A.S. da; Silva Filho, E.

    1988-12-01

    The thermal-hydraulic parameter values that restrict the operation of a liquid sodium cooled reactor are not established by the average conditions of the coolant in the reactor core but by the extreme conditions of the hot channel. The present work was developed to analysis of hot channel of a sodium cooled reactor, adapting to this reactor an existent simplified model for hot channel of pressurized water reactor. The model was applied for a standard sodium reactor and the results are considered satisfatory. (author) [pt

  18. A Unified Physical Model for Creep and Hot Working of Al-Mg Solid Solution Alloys

    Directory of Open Access Journals (Sweden)

    Stefano Spigarelli

    2017-12-01

    Full Text Available The description of the dependence of steady-state creep rate on applied stress and temperature is almost invariably based on the Norton equation or on derived power-law relationships. In hot working, the Norton equation does not work, and is therefore usually replaced with the Garofalo (sinh equation. Both of these equations are phenomenological in nature and can be seldom unambiguously related to microstructural parameters, such as dislocation density, although early efforts in this sense led to the introduction of the “natural power law” with exponent 3. In an attempt to overcome this deficiency, a recent model with sound physical basis has been successfully used to describe the creep response of fcc metals, such as copper. The main advantage of this model is that it does not require any data fitting to predict the strain rate dependence on applied stress and temperature, which is a particularly attractive peculiarity when studying the hot workability of metals. Thus, the model, properly modified to take into account solid solution strengthening effects, has been here applied to the study of the creep and hot-working of simple Al-Mg single phase alloys. The model demonstrated an excellent accuracy in describing both creep and hot working regimes, still maintaining its most important feature, that is, it does not require any fitting of the experimental data.

  19. The study of tribological and corrosion behavior of plasma nitrided 34CrNiMo6 steel under hot and cold wall conditions

    International Nuclear Information System (INIS)

    Maniee, A.; Mahboubi, F.; Soleimani, R.

    2014-01-01

    Highlights: • 34CrNiMo6 steel was plasma nitrided under hot and cold wall conditions. • The amount of ε phase in hot wall condition was more than that of cold wall condition. • Wear resistance of hot wall nitrided samples was more than cold wall treated ones. • Hot wall nitriding provides better corrosion behavior than cold wall nitriding. - Abstract: This paper reports on a comparative study of tribological and corrosion behavior of plasma nitrided 34CrNiMo6 low alloy steel under modern hot wall condition and conventional cold wall condition. Plasma nitriding was carried out at 500 °C and 550 °C with a 25% N 2 + 75% H 2 gas mixture for 8 h. The wall temperature of the chamber in hot wall condition was set to 400 °C. The treated specimens were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness and surface roughness techniques. The wear test was performed by pin-on-disc method. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests were also used to evaluate the corrosion resistance of the samples. The results demonstrated that in both nitriding conditions, wear and corrosion resistance of the treated samples decrease with increasing temperature from 500 °C to 550 °C. Moreover, nitriding under hot wall condition at the same temperature provided slightly better tribological and corrosion behavior in comparison with cold wall condition. In consequence, the lowest friction coefficient, and highest wear and corrosion resistance were found on the sample treated under hot wall condition at 500 °C, which had the maximum surface hardness and ε-Fe 2–3 N phase

  20. Modeling of Possible Conditions for Origin of First Organic Forms in hot Mineral Water

    OpenAIRE

    Ignat Ignatov; Oleg Mosin

    2014-01-01

    The composition of water, its temperature and pH value was analyzed in experiments with modelling of primary hydrosphere and possible conditions for origin of first organic forms in hot mineral water. For this aim the authors performed experiments with hot mineral and seawater from Bulgaria by IR-spectrometry (DNES-method). As model systems were used cactus juice of Echinopsis pachanoi and Mediterranean jellyfish Cotylorhiza tuberculata. It was considered the reactions of condensation and deh...

  1. Radioactive spent resins conditioning by the hot super-compaction process

    International Nuclear Information System (INIS)

    Roth, Andreas; Centner, Baudouin; Lemmens, Alain

    2007-01-01

    Spent ion exchanger media are considered to be problematic waste that, in many cases, requires special approaches and precautions during its immobilization to meet the acceptance criteria for disposal. The waste acceptance criteria define, among others, the quality of waste forms for disposal, and therefore will sometimes define appropriate treatment options. The selection of treatment options for spent ion exchange materials must consider their physical and chemical characteristics. Basically, the main methods for the treatment of spent organic ion exchange materials, following to pretreatment methods are: - Direct immobilization, producing a stable end product by using Cement, Bitumen, Polymer or High Integrity Containers, - The destruction of the organic compounds by using Thermochemical processes or Oxidation to produce an inorganic intermediate product that may or may not be further conditioned for storage and/or disposal, - The complete removal of the resin inner structural water by a thermal process. After a thorough technical economical analysis, Tractebel Engineering selected the Resin Hot Compaction Process to be installed at Tihange Nuclear Power Plant. The Resin Hot Compaction Process is used to make dense homogenous organic blocks from a wide range of particulate waste. In this process spent resins are first dewatered and dried to remove the inner structural water content. The drying takes place in a drying vessel that holds the contents of two 200 L drums (Figure). In the oil heated drying and mixing unit, the resins are heated to the necessary process temperature for the hot pressing step and then placed into special metal drums, which are automatically lidded and immediately transferred to a high force compactor. After high force compaction the pellets are transferred to a measuring unit, where the dose rate, height and weight are automatically measured and recorded. A volume reduction factor of approximately up to four (depending on the type of

  2. Precooling leg muscle improves intermittent sprint exercise performance in hot, humid conditions.

    Science.gov (United States)

    Castle, Paul C; Macdonald, Adam L; Philp, Andrew; Webborn, Anthony; Watt, Peter W; Maxwell, Neil S

    2006-04-01

    We used three techniques of precooling to test the hypothesis that heat strain would be alleviated, muscle temperature (Tmu) would be reduced, and as a result there would be delayed decrements in peak power output (PPO) during exercise in hot, humid conditions. Twelve male team-sport players completed four cycling intermittent sprint protocols (CISP). Each CISP consisted of twenty 2-min periods, each including 10 s of passive rest, 5 s of maximal sprint against a resistance of 7.5% body mass, and 105 s of active recovery. The CISP, preceded by 20 min of no cooling (Control), precooling via an ice vest (Vest), cold water immersion (Water), and ice packs covering the upper legs (Packs), was performed in hot, humid conditions (mean +/- SE; 33.7 +/- 0.3 degrees C, 51.6 +/- 2.2% relative humidity) in a randomized order. The rate of heat strain increase during the CISP was faster in Control than Water and Packs (P body or whole body cooling.

  3. Ignition conditions relaxation for central hot-spot ignition with an ion-electron non-equilibrium model

    Science.gov (United States)

    Fan, Zhengfeng; Liu, Jie

    2016-10-01

    We present an ion-electron non-equilibrium model, in which the hot-spot ion temperature is higher than its electron temperature so that the hot-spot nuclear reactions are enhanced while energy leaks are considerably reduced. Theoretical analysis shows that the ignition region would be significantly enlarged in the hot-spot rhoR-T space as compared with the commonly used equilibrium model. Simulations show that shocks could be utilized to create and maintain non-equilibrium conditions within the hot spot, and the hot-spot rhoR requirement is remarkably reduced for achieving self-heating. In NIF high-foot implosions, it is observed that the x-ray enhancement factors are less than unity, which is not self-consistent and is caused by assuming Te =Ti. And from this non-consistency, we could infer that ion-electron non-equilibrium exists in the high-foot implosions and the ion temperature could be 9% larger than the equilibrium temperature.

  4. Improvement of impact toughness by modified hot working and heat treatment in 13%Cr martensitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Srivatsa, Kulkarni, E-mail: srivatsa.kulkarni@kcssl.com; Srinivas, Perla; Balachandran, G.; Balasubramanian, V.

    2016-11-20

    Improvement of the general mechanical properties and in particular sub-zero impact toughness in a 0.2%C-13%Cr martensitic stainless steel has been explored by varying the hot deformation and heat treatment conditions. The deformation conditions include hot rolling an ingot in one case and cogging the ingot to a semis followed by hot rolling in another case. The bars made from both routes were subjected to a single hardening heat treatment at 980 °C and 1040 °C oil quenched and a double hardening heat treatment at 1040 °C followed by 980 °C oil quenched. The hardened steels were subjected to a standard two stage tempering at 710 °C followed by 680 °C. The impact toughness was found to be doubled in the cogged and rolled steel in double hardened condition. Other processing conditions show varying impact toughness levels. The toughness observed was correlated to the grain size and the carbide distribution in the matrix and the fractography features.

  5. The Effect of Body Weight on Heat Strain Indices in Hot and Dry Climatic Conditions

    Directory of Open Access Journals (Sweden)

    Habibi

    2016-03-01

    Full Text Available Background Being overweight is a characteristic that may influence a person’s heat exchange. Objectives The purpose of this study was to assess the effect of body weight on heat strain indices in hot and dry climatic conditions. Materials and Methods This study was completed with a sample of 30 participants with normal weights, as well as 25 participants who were overweight. The participants were physically inactive for a period of 120 minutes in a climatic chamber with hot and dry conditions (22 - 32°C and with 40% relative humidity (RH.The physiological strain index (PSI and heat strain score index (HSSI questionnaires were used. Simultaneous measurements were completed during heat exposure for periods of five minutes. The resting periods acted as the initial measurements for 15 minutes. Results In both groups, oral temperature, heart rate, and thermal perceptual responses increased during heat exposure. The means and standard deviations of heart rate and oral temperature were gathered when participants were in hot and dry climatic conditions and were not physically active. The heart rates and oral temperatures were 79.21 ± 5.93 bpm and 36.70 ± 0.45°C, respectively, for those with normal weights. For overweight individuals, the measurements for heart rate and oral temperature reached 82.21 ± 8.9 bpm and 37.84 ± 0.37°C, respectively. Conclusions The results showed that, compared to participants with normal weights, physiological and thermal perceptual responses were higher in overweight participants. Therefore, overweight individuals should avoid hot/dry weather conditions to decrease the amount of heat strain.

  6. Criteria for prediction of plastic instabilities for hot working processes. (Part I: Theoretical review)

    International Nuclear Information System (INIS)

    Al Omar, A.; Prado, J. M.

    2010-01-01

    Hot working processes often induce high levels of deformation at high strain rates, and impose very complex multiaxial modes of solicitation. These processes are essentially limited by apparition and development of plastic instabilities. These may be the direct cause of rapid crack propagation, which lead to a possible final rupture. The complexity of deformation modes and the simultaneous intervention of several parameters have led many researchers to develop various criteria, with different approaches, to predict the occurrence of defects and to optimize process control parameters. The aim of the present paper is to summarize the general characteristics of some instability criteria, widely used in the literature, for the prediction of plastic instabilities during hot working. It was considered appropriate to divide the work into two parts: part I presents the phenomenological criteria for the prediction of plastic instabilities, based on descriptive observation of microscopic phenomena of the deformation (strain hardening and strain rate sensitivity), and discusses the continuum criteria based on the principle of maximum rate of entropy production of irreversible thermodynamics applied to continuum mechanics of large plastic flow. Also, this part provides a bibliographical discussion among several authors with regard to the physical foundations of dynamic materials model. In part II, of the work, a comparative study has been carried out to characterize the flow instability during a hot working process of a medium carbon microalloyed using phenomenological and continuum criteria. (Author) 83 refs.

  7. New phenomenological and differential model for hot working of metallic polycrystalline materials

    International Nuclear Information System (INIS)

    Castellanos, J.; Munoz, J.; Gutierrez, V.; Rieiro, I.; Ruano, O. A.; Carsi, M.

    2012-01-01

    This paper presents a new phenomenological and differential model (that use differential equations) to predict the flow stress of a metallic polycrystalline material under hot working. The model, called MCC, depends on six parameters and uses two internal variables to consider the strain hardening, dynamic recovery and dynamic recrystallization processes that occur under hot working. The experimental validation of the MCC model has been carried out by means of stress-strain curves from torsion tests at high temperature (900 degree centigrade a 1200 degree centigrade) and moderate high strain rate (0.005 s-1 to 5 s-1) in a high nitrogen steel. The results reveal the very good agreement between experimental and predicted stresses. Furthermore, the Garofalo a-parameter and the strain to reach 50 % of recrystallized volume fraction have been employed as a control check being a first step to the physical interpretation of variables and parameters of the MCC model. (Author) 26 refs.

  8. The effect of hot working on structure and strength of a precipitation strengthened austenitic stainless steel

    International Nuclear Information System (INIS)

    Mataya, M.C.; Carr, M.J.; Krauss, G.

    1984-01-01

    The development of microstructure and strength during forging a γ' strengthened austenitic stainless steel, JBK-75, was investigated. The specimens were deformed in a strain range of 0.16 to 1.0, from 800 0 C to 1080 0 C at approximate strain rates of 2 (press forging) and 2 X 10 3 S -1 (high energy rate forging). Mechanical properties were determined by tensile testing as-forged and forged and aged specimens. The alloy exhibited a wide variety of structures and properties within the range of forging parameters studied. Deformation at the higher strain rate via high energy rate forging resulted in unrecovered substructures and high strengths at low forging temperatures, and static recrystallization and low strengths at high temperatures. In contrast, however, deformation at the lower strain rate via press forging resulted in retention of the well developed subgrain structure and associated high strength produced at high forging temperatures and strains. At lower temperatures and strains during press forging a subgrain structure formed preferentially at high angle grain boundaries, apparently by a creep-type deformation mechanism. Dynamic recrystallization was not an important restoration mechanism for any of the forging conditions. The results are interpreted on the basis of stacking fault energy and the accumulation of strain energy during hot working. The significance of microstructural differences for equivalent deformation conditions (iso-Z, where Z is the Zener-Holloman parameter) is discussed in relation to the utilization of Z for predicting hot work structures and strengths. Aging showed that γ' precipitation is not affected by substructure and that the strengthening contributions were independent and additive. Applications for these findings are discussed in terms of process design criteria

  9. Study of Low Work Function Materials for Hot Cavity Resonance Ionization Laser Ion Sources

    CERN Document Server

    Catherall, R; Fedosseev, V; Marsh, B; Mattolat, C; Menna, Mariano; Österdahl, F; Raeder, S; Schwellnus, F; Stora, T; Wendt, K; CERN. Geneva. AB Department

    2008-01-01

    The selectivity of a hot cavity resonance ionization laser ion source (RILIS) is most often limited by contributions from competing surface ionization on the hot walls of the ionization cavity. In this article we present investigations on the properties of designated high-temperature, low-work function materials regarding their performance and suitability as cavity material for RILIS. Tungsten test cavities, impregnated with a mixture of barium oxide and strontium oxide (BaOSrO on W), or alternatively gadolinium hexaboride (GdB6) were studied in comparison to a standard tungsten RILIS cavity as being routinely used for hot cavity laser ionization at ISOLDE. Measurement campaigns took place at the off-line mass separators at ISOLDE / CERN, Geneva and RISIKO / University of Mainz.

  10. Study of low work function materials for hot cavity resonance ionization laser ion sources

    CERN Document Server

    Schwellnus, F; Crepieux, B; Fedosseev, V N; Marsh, B A; Mattolat, Ch; Menna, M; Österdahl, F K; Raeder, S; Stora, T; Wendta, K

    2009-01-01

    The selectivity of a hot cavity resonance ionization laser ion source (RILIS) is most often limited by contributions from competing surface ionization of the hot walls of the ionization cavity. In this article we present investigations on the properties of designated high temperature, low work function materials regarding their performance and suitability as cavity material for RILIS. Tungsten test cavities, impregnated with a mixture of barium oxide and strontium oxide (BaOSrO on W), or alternatively gadolinium hexaboride (GdB6) were studied in comparison to a standard tungsten RILIS cavity as being routinely used for hot cavity laser ionization at ISOLDE. Measurement campaigns took place at the off-line mass separators at ISOLDE/CERN, Geneva and RISIKO/University of Mainz.

  11. Hot yoga establishments in local communities serving pregnant women: a pilot study on the health implications of its practice and environmental conditions.

    Science.gov (United States)

    Nguyen-Feng, Viann N; Feng, Steven L; Babbar, Shilpa; Rankins, Nicole Calloway; Blando, James D

    2014-10-01

    Hot yoga establishments have been increasing in popularity in local communities. Studios may support participation among pregnant women though no clinical studies currently exist that examine prenatal hot yoga effects. The pilot study described in this article aimed to assess the spread of prenatal hot yoga and to provide information on the environmental conditions and practices of those who engage in hot yoga within a local community. A thermal environment meter was used to measure ambient air conditions during three 90-minute hot yoga classes. Mothers who practiced prenatal hot yoga were more likely than non-hot yoga practitioners to have someone aside from an obstetrician/gynecologist discuss prenatal exercise safety with them. Prenatal public health education campaigns need to be refined. Public health officials and obstetricians/gynecologists need to be aware that those who engage in a hot yoga practice are more likely to trust someone other than their health care provider or public health professional regarding safety of this practice.

  12. The rule on granting subsidies for survey of hot drainage influences

    International Nuclear Information System (INIS)

    1977-01-01

    The rule is based on the prescriptions of the Law Concerning Proper Budget Enforcement on Subsidies and its Enforcement Order. These rules apply to the granting subsidies provided for by the Enforcement Order for the Special Account Law for Measures Promoting Power Source Development. Terms are defined, such as nuclear power generating facilities; arrangement work for equipments for surveying hot drainage influences; work of preliminary survey of hot drainage; work of surveying hot drainage influences; establishments, etc. The Minister of International Trade and Industry delivers the subsidies for all or a part of the expenses necessary for arrangement work of equipments for surveying hot drainage influences, work of preliminary survey of hot drainage and work of surveying hot drainage influences to the prefectures where nuclear power generating facilities have been or are to be set up, or their neighboring prefectures. Terms of delivery concerning an establishment vary from two years to four years according to the kinds of such subsidies. Limits of the subsidies concerning an establishment range from 10 million yen to 2.5 million yen. The applicant prefecture files the application to the Minister of International Trade and Industry. The Minister examines such applications, and notifies his decision to the applicants. Conditions on delivery, reports submitted by receivers of the subsidies and other matters related are specified. (Okada, K.)

  13. Inhibition of turbulence in inertial-confinement-fusion hot spots by viscous dissipation.

    Science.gov (United States)

    Weber, C R; Clark, D S; Cook, A W; Busby, L E; Robey, H F

    2014-05-01

    Achieving ignition in inertial confinement fusion (ICF) requires the formation of a high-temperature (>10 keV) central hot spot. Turbulence has been suggested as a mechanism for degrading the hot-spot conditions by altering transport properties, introducing colder, mixed material, or reducing the conversion of radially directed kinetic energy to hot-spot heating. We show, however, that the hot spot is very viscous, and the assumption of turbulent conditions in the hot spot is incorrect. This work presents the first high-resolution, three-dimensional simulations of National Ignition Facility (NIF) implosion experiments using detailed knowledge of implosion dynamics and instability seeds and including an accurate model of physical viscosity. We find that when viscous effects are neglected, the hot spot can exhibit a turbulent kinetic energy cascade. Viscous effects, however, are significant and strongly damp small-scale velocity structures, with a hot-spot Reynolds number in the range of only 10-100.

  14. The Effect of Hot Working on Structure and Strength of a Precipitation Strengthened Austenitic Stainless Steel

    Science.gov (United States)

    Mataya, M. C.; Carr, M. J.; Krauss, G.

    1984-02-01

    The development of microstructure and strength during forging in a γ' strengthened austenitic stainless steel, JBK-75, was investigated by means of forward extrusion of cylindrical specimens. The specimens were deformed in a strain range of 0.16 to 1.0, from 800°C to 1080°C, and at approximate strain rates of 2 (press forging) and 2 × 103 s-1 (high energy rate forging), and structures examined by light and transmission microscopy. Mechanical properties were determined by tensile testing as-forged and forged and aged specimens. The alloy exhibited an extremely wide variety of structures and properties within the range of forging pzrameters studied. Deformation at the higher strain rate via high energy rate forging resulted in unrecovered substructures and high strengths at low forging temperatures, and static recrystallization and low strengths at high temperatures. In contrast, however, deformation at the lower strain rate via press forging resulted in retention of the well developed subgrain structure and associated high strength produced at high forging temperatures and strains. At lower temperatures and strains during press forging a subgrain structure formed preferentially at high angle grain boundaries, apparently by a creep-type deformation mechanism. Dynamic recrystallization was not an important restoration mechanism for any of the forging conditions. The results are interpreted on the basis of stacking fault energy and the accumulation of strain energy during hot working. The significance of observed microstructural differences for equivalent deformation conditions (iso-Z, where Z is the Zener-Holloman parameter) is discussed in relation to the utilization of Z for predicting hot work structures and strengths. Aging showed that the γ' precipitation process is not affected by substructure and that the strengthening contributions, from substructure and precipitation, were independent and additive. Applications for these findings are discussed in terms

  15. Modified hot-conditioning of PHT system surfaces of PHWRs

    Energy Technology Data Exchange (ETDEWEB)

    Venkateswaran, G [Bhabha Atomic Research Centre, Trombay, Bombay (India)

    1997-02-01

    The increased awareness on the importance of controlling activity transport and radiation buildup on out-of-core surfaces of water cooled nuclear reactors is leading to a host of measures both from chemistry as well as engineering sides being undertaken. Passivation of the surfaces of structural materials is one such. Pressurised Heavy Water Reactors of CANDU design use large surface area of carbon steel alloy in the Primary Heat Transport System. Hot-conditioning of the PHT system with deoxygenated light water at temperatures {approx_equal} 473 - 523 K during commissioning stage is done to form a protective magnetite film on the surfaces of carbon steel essentially to guard this material from corrosion during the intervening period between initial commissioning and first fuel loading and achieving nuclear heat. However, a need is felt to improve the quality of this magnetite film and control the crud release so that the twin objectives of controlling the corrosion of carbon steel and reducing a possible deposition of corrosion products on surfaces of fuel clad could be achieved. Laboratory static autoclave investigations have been carried out on the formation of protective magnetite film on carbon steel at 473 K, pH 10 (pH at 298 K) deoxygenated aqueous solutions of chelants like HEDTA, DTPA, NTA apart from EDTA. Additionally, influence of AVT chemicals like hydrazine, cyclohexylamine, morpholine and additives like glucose, boric acid has been studied. The data have been compared with the standard procedure of hot-conditioning namely with simple LiOH. It is found that chelants increase the base metal loss but the oxide formed is more protective than the one formed under simple LiOH treatment. The efficiency of passivation is greatly enhanced by hydrazine and boric acid while it is adversely affected by glucose. AVT chemicals acts as effective corrosion inhibitors. (author). 14 refs, 2 figs, 4 tabs.

  16. Modified hot-conditioning of PHT system surfaces of PHWRs

    International Nuclear Information System (INIS)

    Venkateswaran, G.

    1997-01-01

    The increased awareness on the importance of controlling activity transport and radiation buildup on out-of-core surfaces of water cooled nuclear reactors is leading to a host of measures both from chemistry as well as engineering sides being undertaken. Passivation of the surfaces of structural materials is one such. Pressurised Heavy Water Reactors of CANDU design use large surface area of carbon steel alloy in the Primary Heat Transport System. Hot-conditioning of the PHT system with deoxygenated light water at temperatures ≅ 473 - 523 K during commissioning stage is done to form a protective magnetite film on the surfaces of carbon steel essentially to guard this material from corrosion during the intervening period between initial commissioning and first fuel loading and achieving nuclear heat. However, a need is felt to improve the quality of this magnetite film and control the crud release so that the twin objectives of controlling the corrosion of carbon steel and reducing a possible deposition of corrosion products on surfaces of fuel clad could be achieved. Laboratory static autoclave investigations have been carried out on the formation of protective magnetite film on carbon steel at 473 K, pH 10 (pH at 298 K) deoxygenated aqueous solutions of chelants like HEDTA, DTPA, NTA apart from EDTA. Additionally, influence of AVT chemicals like hydrazine, cyclohexylamine, morpholine and additives like glucose, boric acid has been studied. The data have been compared with the standard procedure of hot-conditioning namely with simple LiOH. It is found that chelants increase the base metal loss but the oxide formed is more protective than the one formed under simple LiOH treatment. The efficiency of passivation is greatly enhanced by hydrazine and boric acid while it is adversely affected by glucose. AVT chemicals acts as effective corrosion inhibitors. (author). 14 refs, 2 figs, 4 tabs

  17. Hot-working behavior of an advanced intermetallic multi-phase γ-TiAl based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Schwaighofer, Emanuel, E-mail: emanuel.schwaighofer@unileoben.ac.at [Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Roseggerstr. 12, A-8700 Leoben (Austria); Clemens, Helmut [Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Roseggerstr. 12, A-8700 Leoben (Austria); Lindemann, Janny [Chair of Physical Metallurgy and Materials Technology, Brandenburg University of Technology, Konrad-Wachsmann-Allee 17, D-03046 Cottbus (Germany); GfE Fremat GmbH, Lessingstr. 41, D-09599 Freiberg (Germany); Stark, Andreas [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht (Germany); Mayer, Svea [Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Roseggerstr. 12, A-8700 Leoben (Austria)

    2014-09-22

    New high-performance engine concepts for aerospace and automotive application enforce the development of lightweight intermetallic γ-TiAl based alloys with increased high-temperature capability above 750 °C. Besides an increased creep resistance, the alloy system must exhibit sufficient hot-workability. However, the majority of current high-creep resistant γ-TiAl based alloys suffer from poor workability, whereby grain refinement and microstructure control during hot-working are key factors to ensure a final microstructure with sufficient ductility and tolerance against brittle failure below the brittle-to-ductile transition temperature. Therefore, a new and advanced β-solidifying γ-TiAl based alloy, a so-called TNM alloy with a composition of Ti–43Al–4Nb–1Mo–0.1B (at%) and minor additions of C and Si, is investigated by means of uniaxial compressive hot-deformation tests performed with a Gleeble 3500 simulator within a temperature range of 1150–1300 °C and a strain rate regime of 0.005–0.5 s{sup −1} up to a true deformation of 0.9. The occurring mechanisms during hot-working were decoded by ensuing constitutive modeling of the flow curves by a novel phase field region-specific surface fitting approach via a hyperbolic-sine law as well as by evaluation through processing maps combined with microstructural post-analysis to determine a safe hot-working window of the refined TNM alloy. Complementary, in situ high energy X-ray diffraction experiments in combination with an adapted quenching and deformation dilatometer were conducted for a deeper insight about the deformation behavior of the alloy, i.e. phase fractions and texture evolution as well as temperature uncertainties arising during isothermal and non-isothermal compression. It was found that the presence of β-phase and the contribution of particle stimulated nucleation of ζ-Ti{sub 5}Si{sub 3} silicides and h-type carbides Ti{sub 2}AlC enhance the dynamic recrystallization behavior during

  18. Hot-working behavior of an advanced intermetallic multi-phase γ-TiAl based alloy

    International Nuclear Information System (INIS)

    Schwaighofer, Emanuel; Clemens, Helmut; Lindemann, Janny; Stark, Andreas; Mayer, Svea

    2014-01-01

    New high-performance engine concepts for aerospace and automotive application enforce the development of lightweight intermetallic γ-TiAl based alloys with increased high-temperature capability above 750 °C. Besides an increased creep resistance, the alloy system must exhibit sufficient hot-workability. However, the majority of current high-creep resistant γ-TiAl based alloys suffer from poor workability, whereby grain refinement and microstructure control during hot-working are key factors to ensure a final microstructure with sufficient ductility and tolerance against brittle failure below the brittle-to-ductile transition temperature. Therefore, a new and advanced β-solidifying γ-TiAl based alloy, a so-called TNM alloy with a composition of Ti–43Al–4Nb–1Mo–0.1B (at%) and minor additions of C and Si, is investigated by means of uniaxial compressive hot-deformation tests performed with a Gleeble 3500 simulator within a temperature range of 1150–1300 °C and a strain rate regime of 0.005–0.5 s −1 up to a true deformation of 0.9. The occurring mechanisms during hot-working were decoded by ensuing constitutive modeling of the flow curves by a novel phase field region-specific surface fitting approach via a hyperbolic-sine law as well as by evaluation through processing maps combined with microstructural post-analysis to determine a safe hot-working window of the refined TNM alloy. Complementary, in situ high energy X-ray diffraction experiments in combination with an adapted quenching and deformation dilatometer were conducted for a deeper insight about the deformation behavior of the alloy, i.e. phase fractions and texture evolution as well as temperature uncertainties arising during isothermal and non-isothermal compression. It was found that the presence of β-phase and the contribution of particle stimulated nucleation of ζ-Ti 5 Si 3 silicides and h-type carbides Ti 2 AlC enhance the dynamic recrystallization behavior during deformation within

  19. 29 CFR 1917.152 - Welding, cutting and heating (hot work) 12 (See also § 1917.2, definition of Hazardous cargo...

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Welding, cutting and heating (hot work) 12 (See also Â..., DEPARTMENT OF LABOR (CONTINUED) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.152 Welding... Captain of the Port if welding or other hot work is to be carried out at a facility where dangerous...

  20. Bulging of pressure tubes at hot spots under LOCA conditions

    International Nuclear Information System (INIS)

    Manu, C.; Shewfelt, R.S.W.; Wright, A.C.D.; Aboud, R.; Lau, J.H.K.; Sanderson, D.B.

    1996-01-01

    During certain postulated loss-of-coolant accidents (LOCA) in a CANDU reactor, some fuel channels can become highly voided within a very short time. Although the pressure tubes are heated mainly by convection and thermal radiation during the LOCA transient, additional heat flow occurs through the bearing pads that are in contact with the pressure tribe. This contact can lead to local hot spots and associated thermal stresses in the pressure tube wall. The two factors that affects the behavior of the pressure tubes during LOCA conditions are the internal pressure and the local heating. Although the effect of internal pressure and of axially uniform temperature has been studied elsewhere, the effect of the local heating on the pressure tube behavior has not been modelled before. This paper shows that the bulging of a pressure tube at a hot spot is the result of the thermal stresses that are developed in a pressure tube during a LOCA transient. To isolate the local heating effect from the internal pressure, a series of single-effect experiments was performed. In these experiments, sections of a CANDU pressure tube were subjected to local heating only. The thermal profile and the local deformation were measured function of time. To quantify the effect of the thermal stresses on the bulging of pressure tubes at hot spots and to develop numerical tools that can predict such bulging, finite element analyses were performed rising the ABAQUS finite element computer code. Use of the measured thermal profiles in the ABAQUS finite element analysis, resulted in very good agreement between the predicted and measured displacements. (author)

  1. Effect of heat on firefighters' work performance and physiology.

    Science.gov (United States)

    Larsen, Brianna; Snow, Rodney; Aisbett, Brad

    2015-10-01

    Wildland firefighters often perform their duties under both hot and mild ambient temperatures. However, the direct impact of different ambient temperatures on firefighters' work performance has not been quantified. This study compared firefighters' work performance and physiology during simulated wildland firefighting work in hot (HOT; 32°C, 43% RH) and temperate (CON; 19°C, 56% RH) conditions. Firefighters (n=38), matched and allocated to either the CON (n=18) or HOT (n=20) condition, performed simulated self-paced wildland fire suppression tasks (e.g., hose rolling/dragging, raking) in firefighting clothing for six hours, separated by dedicated rest breaks. Task repetitions were counted (and converted to distance or area). Core temperature (Tc), skin temperature (Tsk), and heart rate were recorded continuously throughout the protocol. Urine output was measured before and during the protocol, and urine specific gravity (USG) analysed, to estimate hydration. Ad libitum fluid intake was also recorded. There were no differences in overall work output between conditions for any physical task. Heart rate was higher in the HOT (55±2% HRmax) compared to the CON condition (51±2% HRmax) for the rest periods between bouts, and for the static hose hold task (69±3% HRmax versus 65±3% HRmax). Tc and Tsk were 0.3±0.1°C and 3.1±0.2°C higher in the HOT compared to the CON trial. Both pre- and within- shift fluid intake were increased two-fold in the heat, and participants in the heat recorded lower USG results than their CON counterparts. There was no difference between the CON and HOT conditions in terms of their work performance, and firefighters in both experimental groups increased their work output over the course of the simulated shift. Though significantly hotter, participants in the heat also managed to avoid excessive cardiovascular and thermal strain, likely aided by the frequent rest breaks in the protocol, and through doubling their fluid intake. Therefore

  2. Work organisation, technology and working conditions

    NARCIS (Netherlands)

    Dhondt, S.; Kraan, K.; Sloten, G. van

    2002-01-01

    The personal computer, computer networks and the Internet have brought the Union into the Information Age. These technological changes have inevitably led to changes in the work environment and the quality of working conditions. For the third time, the European Foundation for the Improvement of

  3. Investigation of Microstructure and Mechanical Properties in Hot-work Tool Steels

    OpenAIRE

    Rey, Tomas

    2017-01-01

    Hot-work tool steels make up an important group of steels that are able to perform with good strength and toughness properties at elevated temperatures and stresses. They are able to gain this behavior through their alloy composition and heat treatment, which relies on the precipitation of alloy carbides to counter the loss in strength as the tempered material becomes more ductile. As demand grows for materials that are suitable for even harsher applications and that show improved mechanical ...

  4. Work-Family Conflict and Working Conditions in Western Europe

    Science.gov (United States)

    Gallie, Duncan; Russell, Helen

    2009-01-01

    This article explores the influence of working conditions on work-family conflict (WFC) among married/cohabiting employees across seven European countries. Using data from the European Social Survey, the paper first investigates the role of working conditions relative to household level characteristics in mediating work-family conflict at the…

  5. Challenges of using air conditioning in an increasingly hot climate

    Science.gov (United States)

    Lundgren-Kownacki, Karin; Hornyanszky, Elisabeth Dalholm; Chu, Tuan Anh; Olsson, Johanna Alkan; Becker, Per

    2018-03-01

    At present, air conditioning (AC) is the most effective means for the cooling of indoor space. However, its increased global use is problematic for various reasons. This paper explores the challenges linked to increased AC use and discusses more sustainable alternatives. A literature review was conducted applying a transdisciplinary approach. It was further complemented by examples from cities in hot climates. To analyse the findings, an analytical framework was developed which considers four societal levels—individual, community, city, and national. The main challenges identified from the literature review are as follows: environmental, organisational, socio-economical, biophysical and behavioural. The paper also identifies several measures that could be taken to reduce the fast growth of AC use. However, due to the complex nature of the problem, there is no single solution to provide sustainable cooling. Alternative solutions were categorised in three broad categories: climate-sensitive urban planning and building design, alternative cooling technologies, and climate-sensitive attitudes and behaviour. The main findings concern the problems arising from leaving the responsibility to come up with cooling solutions entirely to the individual, and how different societal levels can work towards more sustainable cooling options. It is concluded that there is a need for a more holistic view both when it comes to combining various solutions as well as involving various levels in society.

  6. Simulative testing of friction in warm/hot forging

    DEFF Research Database (Denmark)

    Henningsen, Poul; Lindegren, Maria

    The objective of sub-task 3.2 is to determine the friction values for different work piece materials, tool materials and lubricants as a function of the main process parameters under conditions reflecting those which are present in typical warm/hot forming operations i.e. surface expansion, work...... piece and tool temperature. Based on this experimental work establish mathematical formulations of friction as a function of the basic parameters....

  7. Formation of microstructure and properties on hot working and heat treatment of high strength modular cast iron

    International Nuclear Information System (INIS)

    Trajno, A.I.; Yusupov, V.S.; Kugushin, A.A.

    1999-01-01

    The possibility of plastic deformation of high strength modular cast iron (HSNCI) is under study. The microstructure and mechanical properties of hot worked and heat treated cast iron are investigated for the composition, %: Fe - 2.9 C - 2.4 Si - 0.7 Ni - 0.05 Mg - 0.04 Ce. It is stated that HSNCI can withstand various types of hot working without fracturing. Graphite inclusions lose their modular shape irreversibly during plastic deformation. Subsequent heat treatment affects the metal matrix only. The heating in oxidizing environment is noted to result in cast iron surface decarbonization [ru

  8. Sectoral profiles of working conditions

    NARCIS (Netherlands)

    Houtman, I.L.D.; Andries, F.; Berg, R. van den; Dhondt, S.

    2002-01-01

    This report looks at trends in working conditions across different sectors Over the period 1995-2000. Basing its findings on the Third European Survey on Working Conditions (2000) in the 15 EU Member States and Norway, it examines the quality of working life in eighteen different sectors. It

  9. Performance of HEPA filters under hot dynamic conditions

    International Nuclear Information System (INIS)

    Frankum, D.P.; Costigan, G.

    1995-01-01

    Accidents in nuclear facilities involving fires may have implications upon the ventilation systems where high efficiency particulate air (HEPA) filters are used to minimise the airborne release of radioactive or toxic particles. The Filter Development Section at Harwell Laboratory has been investigating the effect of temperature on the performance of HEPA filters under hot dynamic conditions[ 1 ] for a number of years. The test rig is capable of delivering air flows of 10001/s (at ambient conditions) at temperatures up to 500 degrees C, where measurements of the penetration and pressure drop across the filter are obtained. This paper reports the experiments on different constructions of HEPA filters; rectangular and circular. The filters were tested at an air temperature of 200 degrees C for up to 48 hours at the rated airflow to assess their performance. The penetration measurements for rectangular filters were observed to be below 0.021% after prolonged operation. In a number of cases, holes appeared along the pleat creases of circular filters although the penetration remained below 1%. The sealing gasket for these filters was noted to deform with temperature, permitting a leakage path. A prototype high strength circular filter was evaluated at temperatures of up to 400 degrees C with a penetration less than 0.65%

  10. Performance of HEPA filters under hot dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Frankum, D.P.; Costigan, G. [AEA Technology, Oxfordshire (United Kingdom)

    1995-02-01

    Accidents in nuclear facilities involving fires may have implications upon the ventilation systems where high efficiency particulate air (HEPA) filters are used to minimise the airborne release of radioactive or toxic particles. The Filter Development Section at Harwell Laboratory has been investigating the effect of temperature on the performance of HEPA filters under hot dynamic conditions[{sub 1}] for a number of years. The test rig is capable of delivering air flows of 10001/s (at ambient conditions) at temperatures up to 500{degrees}C, where measurements of the penetration and pressure drop across the filter are obtained. This paper reports the experiments on different constructions of HEPA filters; rectangular and circular. The filters were tested at an air temperature of 200{degrees}C for up to 48 hours at the rated airflow to assess their performance. The penetration measurements for rectangular filters were observed to be below 0.021% after prolonged operation. In a number of cases, holes appeared along the pleat creases of circular filters although the penetration remained below 1%. The sealing gasket for these filters was noted to deform with temperature, permitting a leakage path. A prototype high strength circular filter was evaluated at temperatures of up to 400{degrees}C with a penetration less than 0.65%.

  11. Sectoral profiles of working conditions

    NARCIS (Netherlands)

    Houtman, I.L.D.; Parent-Thirion, A.

    2003-01-01

    This report looks at trends in working conditions across different sectors over a five-year period 1995-2000. Basing its findings on the Third European Survey on Working Conditions carried out by the Foundation in 2000 in the 15 EU Member States and Norway, it examines the quality of working life in

  12. Effect of Hot Climatic Conditions With Different Types of Housing on Productive Efficiency and Physiological Changes in Buffalo Calves

    International Nuclear Information System (INIS)

    Habeeb, A.A.M.; Gad, A.E.; El-Tarabany, A.A.

    2012-01-01

    The present study was planned to investigate the effect of housing types under both mild and hot periods of the year on twenty four buffalo calves aged 8-10 months with average body weight 156.8 kg. The study included two periods each was of 3 months. The first period was carried out during mild conditions while the second period was carried out during hot conditions. Averages of air temperature and relative humidity values at midday inside the farm building were 20.8 ± 1.0 degree C and 72.07 ± 2.1% under mild conditions and 35.93± 1.4 degree C and 58.23 ± 1.5 under the hot period, respectively. The estimated temperature-humidity index of values 20.23 and 33.17 during mild and hot conditions, respectively, indicated absence of heat stress during the first period and exposing the animals to very severe heat stress during the second period. The animals during the two experimental periods were fed the concentrate feed mixture according to body weight and daily gain with rice straw offered ad libitum. In each of the two studied periods, the animals were divided into two equal groups according to type of housing system. The animals in the first group (6 calves) were tied from their neck in stall barn in two rows tail to tail while the animals in the second group (6 calves) were left loose housing in the barn. The results showed that heat stress conditions of summer period induced significant decreases in daily body weight gain, total proteins, albumin, globulin, glucose, total lipids, total cholesterol, triglycerides, creatinine, sodium, potassium, calcium, inorganic phosphorus and GGT as well as T4 , T3 , parathormone hormonal levels. On the other hand, significant increase in respiration rate, temperatures of rectal and skin, urea, cortisol, GOT and GPT. Concerning the effect of housing type, there were significant differences in daily body gain of buffalo calves between free and tied through the first two months of experiment, so, daily body gain of buffalo

  13. Modelling Hot Air Balloons.

    Science.gov (United States)

    Brimicombe, M. W.

    1991-01-01

    A macroscopic way of modeling hot air balloons using a Newtonian approach is presented. Misleading examples using a car tire and the concept of hot air rising are discussed. Pressure gradient changes in the atmosphere are used to explain how hot air balloons work. (KR)

  14. Multifunctional design of footwear for hot environment condition

    Science.gov (United States)

    Dragcevic, Z.; Vujasinovic, E.; Hursa Sajatovic, A.

    2017-10-01

    For some time design of a new product is not connected only with aesthetic, artistic appearance but moreover with functionality and engineering (from rightful selection of materials, construction, and technological concept to prototyping). One good example of this is design of multifunctional footwear as well as hiking footwear, footwear for soldiers, police officers, first responders etc. All mentioned kinds of footwear have lot of specific requirements to fulfil starting from maintaining and enhancing mobility to maximizing protection and eliminating or minimizing the risk for the wearer. Therefore, designing appropriate footwear represents a great challenge not only for designers but for engineers as well. Having that entire in mind few years ago, Faculty of Textile Technology University of Zagreb started the research with the aim to develop 21st century multifunctional footwear for e.g. military, police, first respondents or any special human forces for different weather environment. The paper presents how it was done in the case of boots for hot environment conditions

  15. A sector perspective on working conditions

    NARCIS (Netherlands)

    Jettinghoff, K.; Houtman, I.

    2009-01-01

    Every five years the European Foundation for the Improvement of Living and Working Conditions (Eurofound) conducts the European Working Conditions Survey (EWCS). The survey provides an overview of the state of working conditions throughout Europe and indicates the nature and content of changes

  16. Variation of microstructures and mechanical properties of hot heading process of super heat resisting alloy Inconel 718

    International Nuclear Information System (INIS)

    Choi, Hong Seok; Ko, Dae Chul; Kim, Byung Min

    2007-01-01

    Metal forming is the process changing shapes and mechanical properties of the workpiece without initial material reduction through plastic deformation. Above all, because of hot working carried out above recrystallization temperature can be generated large deformation with one blow, it can produce with forging complicated parts or heat resisting super alloy such as Inconel 718 has the worst forgeability. In this paper, we established optimal variation of hot heading process of the Inconel 718 used in heat resisting component and evaluated mechanical properties hot worked product. Die material is SKD61 and initial temperature is 300 .deg. C. Initial billet temperature and punch velocity changed, relatively. Friction coefficient is 0.3 as lubricated condition of hot working. CAE is carried out using DEFORM software before marking the tryout part, and it is manufactured 150 ton screw press with optimal condition. It is know that forming load was decreased according to decreasing punch velocity

  17. Determination of the Interfacial Heat Transfer Coefficient in the Hot Stamping of AA7075

    Directory of Open Access Journals (Sweden)

    Ji Kang

    2016-01-01

    Full Text Available The interfacial heat transfer coefficient (IHTC is a key parameter in hot stamping processes, in which a hot blank is formed and quenched by cold dies simultaneously. The IHTC should therefore be identified and used in FE simulations to improve the accuracy of simulation results of hot stamping processes. In this work, a hot stamping simulator was designed and assembled in a Gleeble 3800 thermo-mechanical testing system and a FE model was built in PAM-STAMP to determine the IHTC values between a hot aluminium alloy 7075 blank and cold dies. The IHTC values were determined at different contact pressures under both dry and lubricated (Omega-35 conditions. In addition, a model to calculate the IHTC value at different contact pressures and area densities of lubricant was developed for the hot stamping process, which was proved to be working well with verification tests.

  18. Reversible electron–hole separation in a hot carrier solar cell

    International Nuclear Information System (INIS)

    Limpert, S; Bremner, S; Linke, H

    2015-01-01

    Hot-carrier solar cells are envisioned to utilize energy filtering to extract power from photogenerated electron–hole pairs before they thermalize with the lattice, and thus potentially offer higher power conversion efficiency compared to conventional, single absorber solar cells. The efficiency of hot-carrier solar cells can be expected to strongly depend on the details of the energy filtering process, a relationship which to date has not been satisfactorily explored. Here, we establish the conditions under which electron–hole separation in hot-carrier solar cells can occur reversibly, that is, at maximum energy conversion efficiency. We thus focus our analysis on the internal operation of the hot-carrier solar cell itself, and in this work do not consider the photon-mediated coupling to the Sun. After deriving an expression for the voltage of a hot-carrier solar cell valid under conditions of both reversible and irreversible electrical operation, we identify separate contributions to the voltage from the thermoelectric effect and the photovoltaic effect. We find that, under specific conditions, the energy conversion efficiency of a hot-carrier solar cell can exceed the Carnot limit set by the intra-device temperature gradient alone, due to the additional contribution of the quasi-Fermi level splitting in the absorber. We also establish that the open-circuit voltage of a hot-carrier solar cell is not limited by the band gap of the absorber, due to the additional thermoelectric contribution to the voltage. Additionally, we find that a hot-carrier solar cell can be operated in reverse as a thermally driven solid-state light emitter. Our results help explore the fundamental limitations of hot-carrier solar cells, and provide a first step towards providing experimentalists with a guide to the optimal configuration of devices. (paper)

  19. Working hot

    International Nuclear Information System (INIS)

    Stix, G.

    1988-01-01

    The author says ''barehand'' methods, where specially trained utility workers are called in conductive suits to equalize voltage over their bodies, to maintain high-voltage transmission lines are on the rise. Utilities are building lines at higher voltages and selling more power to other utilities, making it highly inconvenient to take the lines out of service. However, some unions view the barehand work with less than enthusiasm. Touching lines energized at hundreds of thousands of volts demands flawless equipment and rigid work procedures followed to the letter. Some local unions contend that adequate safety procedures and training, and appropriate penalties for workplace negligence, should be in place before utilities may do barehand work. The author discusses some of the methods of barehand work and the equipment used, i.e. steel-mesh lineman's suit, bucket truck's boom, helicopters, and robots

  20. The comparison of two continuum damage mechanics-based material models for formability prediction of AA6082 under hot stamping conditions

    Science.gov (United States)

    Shao, Z.; Li, N.; Lin, J.

    2017-09-01

    The hot stamping and cold die quenching process has experienced tremendous development in order to obtain shapes of structural components with great complexity in automotive applications. Prediction of the formability of a metal sheet is significant for practical applications of forming components in the automotive industry. Since microstructural evolution in an alloy at elevated temperature has a large effect on formability, continuum damage mechanics (CDM)-based material models can be used to characterise the behaviour of metals when a forming process is conducted at elevated temperatures. In this paper, two sets of unified multi-axial constitutive equations based on material’s stress states and strain states, respectively, were calibrated and used to effectively predict the thermo-mechanical response and forming limits of alloys under complex hot stamping conditions. In order to determine and calibrate the two material models, formability tests of AA6082 using a developed novel biaxial testing system were conducted at various temperatures and strain rates under hot stamping conditions. The determined unified constitutive equations from experimental data are presented in this paper. It is found that both of the stress-state based and strain-state based material models can predict the formability of AA6082 under hot stamping conditions.

  1. Performance Characteristics of Hero's Turbine Using Hot Water as a Working Fluid

    OpenAIRE

    藤井, 照重; 太田, 淳一; 赤川, 浩爾; 中村, 登志; 浅野, 等

    1990-01-01

    From the view point of energy saving and the development of new energy resources,it is important to utilize geothermal resources and waste heat from factories. As one of the energy conversion expanders,there is a radial outflow reaction turbine(that is,Hero's turbine). Performance characteristics of Hero's turbine using subcooled hot water as a working fluid are clarified analytically and experimentally. It is found that:(a)there is an optimum rotational speed at which maximum turbine efficie...

  2. Operating experience and radiation protection problems in the working of the radio-metallurgy hot cell facilities at BARC

    International Nuclear Information System (INIS)

    Janardhanan, S.; Watamwar, S.B.; Mehta, S.K.; Pillai, P.M.B.; John, Jacob; Kutty, K.N.

    1977-01-01

    The Bhabha Atomic Research Centre at Bombay has six hot cell facilities for radiometallurgical investigations of irradiated/failed fuel elements. The hot cell facilities have been provided with certain built-in safety features, a ventilation system, radiation monitoring instruments for various purposes, a centralised air monitoring system and a central panel for display of various alarms. Procedures adopted for radiation protection and contamination control include : (1) radiation leak test for cells and filter efficiency evaluation before cell activation, (2) practices to be followed by frog suit personnel while working in hot cell areas, (3) receipt and handling of irradiated fuel elements, (4) cell filter change operation, (5) checks on high level drains and (6) effluent discharge and waste shipments. Operating experience in the working of these facilities along with radiation accident incidents is described. Data regarding release of activity during normal cell operations, dose rates during various metallurgical operations and personnel exposures are presented. (M.G.B.)

  3. Hot ductility behavior of near-alpha titanium alloy IMI834

    International Nuclear Information System (INIS)

    Ghavam, Mohammad Hadi; Morakabati, Maryam; Abbasi, Seyed Mahdi; Badri, Hassan

    2014-01-01

    The hot ductility of rolled IMI834 titanium alloy (Ti-5.3Al-2.9Sn-3.0Zr-0.65Nb-0.5Mo-0.2Si in wt%) has been studied by conducting tensile tests with a strain rate of 0.1 s -1 and temperature range of 750-1100 C to obtain the optimum hot working conditions. The alloy showed minimum hot ductility in the lower alpha-beta region in the temperature range 750-950 C. Further microstructural characterizations showed improvement in hot ductility by increasing temperature, which was attributed to reduction of volume fraction of high strength alpha phase. The best hot ductility was observed at 1000 C, i.e. in the upper alpha-beta region. The better hot ductility at higher temperature could be related to the increase in the volume fraction of beta phase and the occurrence of dynamic restoration phenomena. The second decline in hot ductility appeared at higher temperatures in the beta region and was attributed to the high stacking fault energy and self-diffusion of beta phase leading to limitation of dynamic recrystallization.

  4. Evaluation of the mechanical properties of Niobium modified cast AISI H 13 hot work tool steel

    International Nuclear Information System (INIS)

    Noorian, A.; Kheirandish, Sh.; Saghafian, H.

    2010-01-01

    In this research, the effects of partially replacing of vanadium and molybdenum with niobium on the mechanical properties of AISIH 13 hot-work tool steel have been studied. Cast samples made of the modified new steel were homogenized and austenitized at different conditions, followed by tempering at the specified temperature ranges. Hardness, red hardness, three point bending test and Charpy impact test were carried out to evaluate the mechanical properties together with characterizing the microstructure of the modified steel using scanning electron microscope. The results show that niobium addition modifies the cast structure of Nb-alloyed steel, and increases its maximum hardness. It was found that bending strength; bending strain, impact strength, and red hardness of the modified cast steel are also higher than those of the cast H13 steel, and lower than those of the wrought H13 steel.

  5. Robot Work Platform for Large Hot Cell Deactivation

    International Nuclear Information System (INIS)

    BITTEN, E.J.

    2000-01-01

    The 324 Building, located at the Hanford Site near Richland, Washington, is being deactivated to meet state and federal cleanup commitments. The facility is currently in its third year of a nine-year project to complete deactivation and closure for long-term surveillance and maintenance. The 324 building contains large hot cells that were used for high-radiation, high-contamination chemical process development and demonstrations. A major obstacle for the 324 deactivation project is the inability to effectively perform deactivation tasks within highly radioactive, contaminated environments. Current strategies use inefficient, resource intensive technologies that significantly impact the cost and schedule for deactivation. To meet mandated cleanup commitments, there is a need to deploy rapid, more efficient remote/robot technologies to minimize worker exposure, accelerate work tasks, and eliminate the need for multiple specialized tool design and procurement efforts. This paper describes the functions and performance requirements for a crane-deployed remote/robot Work Platform possessing full access capabilities. The remote/robot Work Platform will deploy commercially available off-the-shelf tools and end effectors to support Project cleanup goals and reduce overall project risk and cost. The intent of this system is to maximize the use of off-the-shelf technologies that minimize additional new, unproven, or novel designs. This paper further describes procurement strategy, the selection process, the selected technology, and the current status of the procurement and lessons learned. Funding, in part, has been provided by the US Department of Energy, Office of Science and Technology, Deactivation and Decommissioning Focus Area

  6. Working Conditions, Lifestyles and Health

    DEFF Research Database (Denmark)

    Cottini, Elena; Ghinetti, Paolo

    The aim of this paper is to investigate whether employee health is affected by the environment in which the individual works - in terms of both physical and psychosocial working conditions - and by his or her lifestyle. Health measures are computed from Danish data, and refer to both self assessed...... general health and two more objective health measures: mental health specific to work-related problems, and physical health. We find that both bad working conditions and bad lifestyles reduce health, especially in its self-assessed component. The impact of lifetsyle indicators have a more modest health...... impact on both physical and mental health....

  7. Is work engagement related to work ability beyond working conditions and lifestyle factors?

    Science.gov (United States)

    Airila, Auli; Hakanen, Jari; Punakallio, Anne; Lusa, Sirpa; Luukkonen, Ritva

    2012-11-01

    To examine the associations of age, lifestyle and work-related factors, and particularly work engagement with the work ability index (WAI) and its sub-dimensions. Step-wise regression analysis with a sample of Finnish firefighters (n = 403) was used. The outcome variables were the WAI and its six sub-dimensions. The independent variables consisted of age, lifestyle variables (alcohol consumption, BMI, smoking, physical exercise, and sleep problems), working conditions (job demands, physical workload, supervisory relations, and task resources), and work engagement. The outcome variables and all the variables related to lifestyle, working conditions, and work engagement were measured in 2009. Work ability at baseline 10 years earlier was adjusted for in the models. Work engagement, age, physical exercise, sleep problems, and physical workload were associated with the WAI. All independent variables, except BMI and alcohol consumption, were associated with at least one sub-dimension of the WAI after controlling the baseline WAI. Lifestyle variables, working conditions, and work engagement were more strongly related to the subjective WAI sub-dimensions than to the two more objective WAI sub-dimensions. Work engagement was significantly associated with work ability even after adjusting for various factors, indicating its importance in promoting work ability. Other key factors for good work ability were frequent exercise, good sleep, non-smoking, low job demands, low physical workload, and high task resources. More specifically, this study suggests that in maintaining work ability, it is valuable not only to promote lifestyle factors or working conditions, but also to enhance employees' positive state of work engagement.

  8. Hot forming of composite prepreg : Experimental study

    Science.gov (United States)

    Tardif, Xavier; Duthille, Bertrand; Bechtel, Stephane; le Pinru, Louis; Campagne, Benjamin; Destombes, Gautier; Deshors, Antoine; Marchand, Christophe; Azzouzi, Khalid El; Moro, Tanguy

    2017-10-01

    The hot forming of thermoset prepreg consists in bending an uncured composite part by applying a mechanical constrain on the hot laminate. Most of the time, the mold is inserted in a vacuum box and the mechanical constrain is applied on the composite laminate by a single membrane or a double-membrane. But the performance improvement products resulted in forming increasingly complex parts with advanced materials having a less formability. These new complex parts require a finer comprehension of the process and an optimization of the key parameters to get acceptable quality. In this work, an experimental study has been carried out to identify the process conditions that do not lead to unacceptable defaults: undulations of fibers. In the present study, downward-bending has been evaluated with an original light mechanical forming concept, for a given stacking sequence. The influence of the part's temperature and the part's bending speed are investigated. To carry this study out, a hot forming test bench has been designed and manufactured to have a precise supervision of the process conditions. It is able to bend parts of 1500 mm length x 600 mm width x 20 mm thick.

  9. Health workers' perception on the work, working conditions ...

    African Journals Online (AJOL)

    ... the philosophy that ensures proper utilization of human resources that would ... on the work, working conditions, compensation, and career development in a ... of human resources management practices to change the negative perceptions ...

  10. Experimental Study of Ignition by Hot Spot in Internal Combustion Engines

    Science.gov (United States)

    Serruys, Max

    1938-01-01

    In order to carry out the contemplated study, it was first necessary to provide hot spots in the combustion chamber, which could be measured and whose temperature could be changed. It seemed difficult to realize both conditions working solely on the temperature of the cooling water in a way so as to produce hot spots on the cylinder wall capable of provoking autoignition. Moreover, in the majority of practical cases, autoignition is produced by the spark plug, one of the least cooled parts in the engine. The first procedure therefore did not resemble that which most generally occurs in actual engine operation. All of these considerations caused us to reproduce similar hot spots at the spark plugs. The hot spots produced were of two kinds and designated with the name of thermo-electric spark plug and of metallic hot spot.

  11. Determination of the constants of constitutive hot working equations and obtention of ISO-Z {sigma} x {epsilon} curves for Al-Li alloys; Determinacao das constantes de equacoes constitutivas de trabalho a quente e obtencao de curvas {sigma} x {epsilon} ISO-Z para ligas Al-Li

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Marcelo [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Simielli, Eider A [Coordenadoria para Projetos Especiais (COPESP), Sao Paulo, SP (Brazil)

    1993-12-31

    A method for determining the contents of constructive hot working equations are described. The experimental data used were obtained by plane strain compression tests for different conditions of temperature and strain rate, for both alloys 8090 and 8091. The results are very important due to their applicability in the prediction of stress and microstructural features developed during hot working of the alloys studied. (author). 8 refs., 5 figs.

  12. Chronic health conditions and work ability in the ageing workforce: the impact of work conditions, psychosocial factors and perceived health.

    Science.gov (United States)

    Koolhaas, Wendy; van der Klink, Jac J L; de Boer, Michiel R; Groothoff, Johan W; Brouwer, Sandra

    2014-05-01

    The aim of this study was to determine the influence of work conditions, psychosocial factors and perceived health on the association between the presence of a chronic health condition and (single-item) work ability among workers aged 45 years and older. In addition, we aimed to examine variables associated with work ability for workers with and without a chronic health condition separately. The data of this cross-sectional study were obtained from 5,247 workers aged 45 years and older in five different work sectors. Work ability was assessed with the first item of the Work Ability Index. The presence of a chronic health condition was assessed by self-report. Independent variables in the multivariable linear regression analysis were work conditions, psychosocial factors and perceived health status. The presence of a chronic health condition was negatively associated with work ability (B = -0.848). The strength of this association slightly attenuated after subsequently adding individual characteristics (B = -0.824), work conditions (B = -0.805) and more so after adding psychosocial factors (B = -0.704) and especially perceived health variables (B = -0.049) to the model. Variables associated with work ability for workers with and without a chronic health condition were similar. Perceived health and psychosocial factors, rather than work conditions, explained the association between the presence of a chronic health condition and work ability. Substantial differences in variables associated with work ability for workers with and without a chronic health condition were not found. Based on the lower mean scores for workers with a chronic health condition and work ability as well for predictors, these workers might have the most benefit by a policy focussing on enhancing these associated variables.

  13. A model for construction of efficiency and stability maps of hot working processes in polycrystalline metallic materials using the Garofalo's equation

    International Nuclear Information System (INIS)

    Rieiro, I.; Fernandez, A.; Martinez, A.; Casi, M.

    1998-01-01

    Has been developed a fast and easy method for to evaluate the efficiency of the process and some or possible stabilities situations in the hot working process for the polycrystalline metallic materials (p.m.m.), by the obtained dates in the Garofalo's equation resolution for the steady state creep and for wide ranges of the work variables, stress, strain rate and temperature. These method use the fitting parameters obtained for the equation mentioned and of their physical meaning. Has been developed the numerical treatment from our previously developed software for the analysis of creep and we can obtained the efficiency energetic maps for the creep and the more generally advises areas for the hot working. Further more has been obtained maps for parameters of great physical significance; f.e. the effective activation energy for different areas of the materials hot working, and in addition has been developed a method for obtained the values of {n P L} for the different ranges of power-law application, when has been obtained the value of { n G } in the Garofalo's equation. (Author) 13 refs

  14. Microstructural study and densification analysis of hot work tool steel matrix composites reinforced with TiB{sub 2} particles

    Energy Technology Data Exchange (ETDEWEB)

    Fedrizzi, A., E-mail: anna.fedrizzi@ing.unitn.it [Department of Industrial Engineering, University of Trento, Via Mesiano 77, 38123 Trento (Italy); Pellizzari, M. [Department of Industrial Engineering, University of Trento, Via Mesiano 77, 38123 Trento (Italy); Zadra, M. [K4Sint, Start-up of the University of Trento, Viale Dante 300, 38057 Pergine Valsugana (Italy); Marin, E. [Department of Chemistry, Physics and Environment, University of Udine, Via Cotonificio 108, 33100 Udine (Italy)

    2013-12-15

    Hot work tool steels are characterized by good toughness and high hot hardness but are less wear resistant than other tooling materials, such as high speed steel. Metal matrix composites show improved tribological behavior, but not much work has been done in the field of hot work tool steels. In this paper TiB{sub 2}-reinforced hot work tool steel matrix composites were produced by spark plasma sintering (SPS). Mechanical alloying (MA) was proposed as a suited process to improve the composite microstructure. Density measurements and microstructure confirmed that MA promotes sintering and produces a fine and homogeneous dispersion of reinforcing particles. X-ray diffraction patterns of the sintered composites highlighted the formation of equilibrium Fe{sub 2}B and TiC, as predicted by thermodynamic calculations using Thermo-Calc® software. Scanning electron microscopy as well as scanning Kelvin probe force microscopy highlighted the reaction of the steel matrix with TiB{sub 2} particles, showing the formation of a reaction layer at the TiB{sub 2}-steel interface. Phase investigations pointed out that TiB{sub 2} is not chemically stable in steel matrix because of the presence of carbon even during short time SPS. - Highlights: • TiB{sub 2} reinforced steel matrix composites were produced by spark plasma sintering. • TiB{sub 2} was successfully dispersed in the steel matrix by mechanical alloying. • Steel and TiB{sub 2} react during sintering forming equilibrium Fe{sub 2}B and TiC. • The new phases were investigated by means of AFM, Volta potential and XRD analyses.

  15. Working conditions, work life and quality of life of the temporary ...

    African Journals Online (AJOL)

    Working conditions, work life and quality of life of the temporary support staff ... and expectations of the temporary support staff with regard to their working ... conditions mainly as unpleasant, but that they adapted because of the team spirit.

  16. The impact of the hot tap water load pattern in the industrial hall on the energy yield from solar collectors

    Science.gov (United States)

    Fidorów-Kaprawyl, Natalia; Dudkiewicz, Edyta

    2017-11-01

    The systems using solar energy, popular in Poland, can be used to supply hot water for the installation used by employees of industrial halls. In manufacturing plants, employing a large number of people, the demand for hot water is practically constant throughout the year and is characterized by periodic use at the end of each work shift. Dynamics of the hot water consumption depends on the number of shifts as well as working days and holidays. Additionally the maximum hot tap water demand occurs in the whole period of installation operation. In polish climatic conditions the solar collectors' systems have the largest capacity in the summer, while in winter they need to be assisted. Beside that the supply of renewable energy is uneven and depends on weather conditions. In the paper the one-hour step analysis concerning the dependence of the load pattern of the hot tap water preparation system on the energy yield from solar collectors had been performed.

  17. Gendered work conditions, health, and work outcomes.

    Science.gov (United States)

    Bond, Meg A; Punnett, Laura; Pyle, Jean L; Cazeca, Dianne; Cooperman, Manuela

    2004-01-01

    This cross-sectional study of nonfaculty university employees examined associations among gendered work conditions (e.g., sexism and discrimination), job demands, and employee job satisfaction and health. Organizational responsiveness and social support were examined as effect modifiers. Comparisons were made by gender and by the male-female ratio in each job category. The relationship of gendered conditions of work to outcomes differed on the basis of respondents' sex and the job sex ratio. Although the same predictors were hypothesized for job satisfaction, physical health, and psychological distress, there were some differing results. The strongest correlate of job satisfaction was social support; perceived sexism in the workplace also contributed for both men and women. Organizational factors associated with psychological distress differed between female- and male-dominated jobs.

  18. Perceived Work Conditions and Turnover Intentions: The Mediating Role of Meaning of Work

    Science.gov (United States)

    Arnoux-Nicolas, Caroline; Sovet, Laurent; Lhotellier, Lin; Di Fabio, Annamaria; Bernaud, Jean-Luc

    2016-01-01

    Perceived working conditions lead to various negative outcomes for employee behaviors, including turnover intentions. Although potential mediators for these relationships were previously identified, the importance of meaning of work has not yet been investigated. This study examines the role of this psychological resource as a mediator for the relationships between perceived working conditions and turnover intentions in a sample of 336 French workers from different job contexts. Results show that adverse working conditions were positively and significantly associated with turnover intentions. Meaning of work is negatively related to both perceived working conditions and turnover intentions. Mediation analyses for meaning of work demonstrated indirect effects of several adverse working conditions on turnover intentions. The role of meaning of work as a psychological resource for employees facing adverse working conditions is discussed, especially regarding its implications for research and practice within organizational contexts. PMID:27242616

  19. Perceived Work Conditions and Turnover Intentions: The Mediating Role of Meaning of Work.

    Science.gov (United States)

    Arnoux-Nicolas, Caroline; Sovet, Laurent; Lhotellier, Lin; Di Fabio, Annamaria; Bernaud, Jean-Luc

    2016-01-01

    Perceived working conditions lead to various negative outcomes for employee behaviors, including turnover intentions. Although potential mediators for these relationships were previously identified, the importance of meaning of work has not yet been investigated. This study examines the role of this psychological resource as a mediator for the relationships between perceived working conditions and turnover intentions in a sample of 336 French workers from different job contexts. Results show that adverse working conditions were positively and significantly associated with turnover intentions. Meaning of work is negatively related to both perceived working conditions and turnover intentions. Mediation analyses for meaning of work demonstrated indirect effects of several adverse working conditions on turnover intentions. The role of meaning of work as a psychological resource for employees facing adverse working conditions is discussed, especially regarding its implications for research and practice within organizational contexts.

  20. Nurse working conditions and patient safety outcomes.

    Science.gov (United States)

    Stone, Patricia W; Mooney-Kane, Cathy; Larson, Elaine L; Horan, Teresa; Glance, Laurent G; Zwanziger, Jack; Dick, Andrew W

    2007-06-01

    System approaches, such as improving working conditions, have been advocated to improve patient safety. However, the independent effect of many working condition variables on patient outcomes is unknown. To examine effects of a comprehensive set of working conditions on elderly patient safety outcomes in intensive care units. Observational study, with patient outcome data collected using the National Nosocomial Infection Surveillance system protocols and Medicare files. Several measures of health status and fixed setting characteristics were used to capture distinct dimensions of patient severity of illness and risk for disease. Working condition variables included organizational climate measured by nurse survey; objective measures of staffing, overtime, and wages (derived from payroll data); and hospital profitability and magnet accreditation. The sample comprised 15,846 patients in 51 adult intensive care units in 31 hospitals depending on the outcome analyzed; 1095 nurses were surveyed. Central line associated bloodstream infections (CLBSI), ventilator-associated pneumonia, catheter-associated urinary tract infections, 30-day mortality, and decubiti. Units with higher staffing had lower incidence of CLBSI, ventilator-associated pneumonia, 30-day mortality, and decubiti (P working conditions were associated with all outcomes measured. Improving working conditions will most likely promote patient safety. Future researchers and policymakers should consider a broad set of working condition variables.

  1. Investigations of Surface Topography of Hot Working Tool Steel Manufactured with the Use of 3D Print

    Directory of Open Access Journals (Sweden)

    Grobelny Pawel

    2017-01-01

    Full Text Available The paper presents the possibilities of 3D printing of chosen hot working tool steel for manufacturing ready made parts. Results of examination of the surface topography of material manufactured by the technology Laser CUSING®B (Laser melting with metals on the machine, Concept Laser M1 3D printing of metal parts has the potential to revolutionize the market of manufacturing and supplying parts. It makes it possible to dissipate manufacturing and to produce parts on request at lower cost and less energy consumption. The parameters of the surface topography of the hot working tool steel directly after printing can differ depending on the distance from the base plate. The differences of surface roughness values can amount from 32% to 85% for Ra and from 59% to 85% for Rz in comparison of the sample bottom to its top.

  2. Urban heat island and bioclimatological conditions in a hot-humid tropical city: the example of Akure, Nigeria

    Directory of Open Access Journals (Sweden)

    Balogun, Ifeoluwa A.

    2014-09-01

    Full Text Available The impact of weather on human health has become an issue of increased significance in recent times, considering the increasing rate of urbanisation and the much associated heat island phenomenon. This study examines the urbanisation influence on human bioclimatic conditions in Akure, a medium sized hot-humid tropical city in Nigeria, utilising data from measurements at urban and rural sites in the city. Differences in the diurnal, monthly and seasonal variation of human bioclimatic characteristics between both environments were evaluated and tested for statistical significance. Higher frequencies of high temperatures observed in the city centre suggest a significant heat stress and health risk in this hot-humid city.

  3. To enhance the cooling comfort condition in home by water spray upon the roof in hot arid region experimental work

    International Nuclear Information System (INIS)

    Abdul Sada, Ghanim Kadhem; Al Shammaa, Mostafa Khairy

    2006-01-01

    Fossil fuel shortages have been in recent years a critical problem in the world and are likely to be continued. A major part of consumed energy nowadays is used to thermally control building environment where solar radiation has a major contribution, specially in Iraq and other hot arid region where most of the day in the year are sunny. Baghdad, which is considered a typical place with this extreme climate, is chosen, in this study. This work deals with the possibility of the reducing energy consumption in building by blocking or eliminate the effect of direct solar radiation in summer season which the cooling is dominate in Iraq. It is especially important to minimize the effect of solar radiation incident upon the roof surface, which is focusing about it in this study. The roof surface most exposed to solar radiation and most of the solar gain absorbed by roof is transmitted down to the inside space. In this study built a system which spry water upon the external surface consist of net work piping system, control valves, spry nozzles, thermocouples sensor and digital temperature indicators. The study has been done in order to reduce the cooling load in living room. Reducing the heat transfer through the roof by using water spry roof system (WSRS) in Iraq's houses which reduced the heat transmission to the inside space about 96%. The result of this study shows good indication to use this method, to reduce the energy transmission. i./e. the energy transmission to inside living space through roof is about 4% only.(Author)

  4. Hot cells for testing the UO{sub 2} fuel elements after irradiation. Radiation protection conditions for hot cells design; Vruce celije za ispitivanje gorivnih elemenata UO{sub 2} posle ozracivanja, Uslovi zastite pri projektovanju vrucih celija

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, A; Devic, J; Mihailovic, K [Institut za nuklearne nauke Vinca, Belgrade (Yugoslavia)

    1969-07-01

    This paper includes protection conditions which hot cells should satisfy for the investigation of fuel elements after reactor irradiation. The basic elements of hot cells are given, and the conditions for a special ventilation, dosimetric control and a special treatment of contaminated water are established (author) U radu su obuhvaceni uslovi zastite koje treba da zadovolje vruce celije za ispitivanje gorivnih elemenata posle ozracivanja u reaktoru, dati su osnovni elementi vrucih celija i postavljeni su uslovi za specijalnu ventilaciju, dozimentrijsku kontrolu i specijalni tretman otpadnih voda (author)

  5. Development of a pattern hot cell for production of injectable radiopharmaceuticals

    International Nuclear Information System (INIS)

    Campos, Fabio Eduardo de

    2010-01-01

    A controlled ambient should be established to the production/processing of materials susceptible to contamination, like injectable pharmaceuticals, in order to agree with normative and regulatory requirements. Considering medical but also toxic, radioactive and dangerous products, the ambient should work in special conditions to assure that the materials, which in same cases can be also volatile, do not escape to the external ambient, working in a selective, secure and controlled way. The conditions recommended by local and international rules in use, report an negative pressured ambient in relation to the adjacent areas. The technology related with the sizing of project to this kind of system is fully described in the literature, taking in account the rules that clearly describe the essential requirements. However, it is necessary to develop a controlled ambient for radiopharmaceutical production, in a way compatible with the concept of clean rooms and with the safety related to the manipulation of open radioactive wastes. In this work, some devices were created, methods and procedures were established making possible the classification of the ambient inside the hot cell, without physical barriers in the area, using ergonomic, flexible and practical conditions of work, that can results in the improvement of the productivity. The project resulted in the creation of a controlled ambient, in agreement with the normative requirements, using a pass through for entrance and exit of the materials, without compromise the internal air condition. The tight of the hot cell was obtained using doors with efficient sealing system and active joints. Tong manipulators were used to produce ergonomic and secure conditions, without compromise the internal conditions related to tight and classification in A and B grade, according to local and international rules. An efficient ventilation/exhaustion system was adopted to produce these results, composed by filters and special devices

  6. Processing map and hot working mechanisms in a P/M TiAl alloy composite with in situ carbide and silicide dispersions

    International Nuclear Information System (INIS)

    Rao, K.P.; Prasad, Y.V.R.K.

    2010-01-01

    Research highlights: Mechanical alloying of Ti and Al with small additions of Si and C was used to synthesize metastable phases, which were incorporated in Ti-Al matrices using powder metallurgy techniques. These metastable phases (or also called as precursors), at higher temperatures, transformed in situ into very fine hard reinforcements that develop coherent interface with the surrounding matrix. Typically, Ti5Si3 and TiC are the end products after the synthesis of composite. In this study, hot working behavior of such composites has been studied using the concepts of processing maps to identify the safe and best processing conditions that should be adopted while forming this composite. Also, kinetic analysis of hot deformation has been performed to identify the dominant deformation mechanism. The results are compared with that of base TiAl matrix. The powder metallurgy route offers the advantage of working the material at much lower temperatures compared to the traditional cast and forge route. - Abstract: A titanium aluminide alloy composite with in situ carbide and silicide dispersions has been synthesized by mixing 90% of matrix with elemental composition of 46Ti-46Al-4Nb-2Cr-2Mn and 10% precursor with composition 55Ti-27Al-12Si-6C prepared by mechanical alloying. The powder mixture was blended for 2 h followed by hot isostatic pressing (HIP) at 1150 deg. C for 4 h under a pressure of 150 MPa. In addition to TiAl alloy matrix, the microstructure of the HIP'ed billet showed a small volume fraction of Nb-rich intermetallic phase along with carbide and silicide dispersions formed in situ during HIP'ing. Cylindrical specimens from the HIP'ed billets were compressed at temperatures and strain rates in the ranges of 800-1050 deg. C and 0.0001-1 s -1 . The flow curves exhibited flow softening leading to a steady-state flow at strain rates lower than 0.01 s -1 while fracture occurred at higher strain rates. The processing map developed on the basis of flow stress at

  7. Microstructure distribution and mechanical properties prediction of boron alloy during hot forming using FE simulation

    International Nuclear Information System (INIS)

    Cui Junjia; Lei Chengxi; Xing Zhongwen; Li Chunfeng

    2012-01-01

    Highlights: ► We model microstructural evolution during hot forming using a metallo-thermo-mechanical model. ► The effect of water-cooled on temperature distribution of blank and tools was investigated. ► The effect of process parameters on microstructure and mechanical properties were investigated. ► FE results were compared to experimental results and the errors of mechanical properties were in a reasonable scope. - Abstract: As a theoretical tool predicting microstructural evolution of boron alloy, the finite element (FE) method has received considerable attention in recent years. In this work, we focus on the boron alloy under non-isothermal hot forming conditions and establish a fully coupled metallo-thermo-mechanical model taking account of cooling and oxide. Based on the proposed model, we investigate the phase transformation and predict the hardness during the hot forming process via FE simulation. In addition, according to the hardness, the tensile strength during non-isothermal forming is predicted. Supporting the feasibility of the proposed model is the experiments where BR1500HS alloy is hot-worked at various conditions that derive a promising agreement of microstructures, hardness, and tensile strength to the simulation data.

  8. Determination of Proper Austenitization Temperatures for Hot Stamping of AISI 4140 Steel

    Science.gov (United States)

    Samadian, Pedram; Parsa, Mohammad Habibi; Shakeri, Amid

    2014-04-01

    High strength steels are desirable materials for use in automobile bodies in order to reduce vehicle weight and increase the safety of car passengers, but steel grades with high strength commonly show poor formability. Recently, steels with controlled microstructures and compositions are used to gain adequate strength after hot stamping while maintaining good formability during processing. In this study, microstructure evolutions and changes in mechanical properties of AISI 4140 steel sheets resulting from the hot stamping process at different austenitization temperatures were investigated. To determine the proper austenitization temperatures, the results were compared with those of the cold-worked and cold-worked plus quench-tempered specimens. Comparisons showed that the austenitization temperatures of 1000 and 1100 °C are proper for hot stamping of 3-mm-thick AISI 4140 steel sheets due to the resultant martensitic microstructure which led to the yield and ultimate tensile strength of 1.3 and 2.1 GPa, respectively. Such conditions resulted in more favorable simultaneous strength and elongation than those of hot-stamped conventional boron steels.

  9. Determination of the interfacial heat transfer coefficient in the hot stamping of AA7075

    Directory of Open Access Journals (Sweden)

    Liu Xiaochuan

    2015-01-01

    Full Text Available The interfacial heat transfer coefficient (IHTC is a key parameter in hot stamping processes, in which a hot blank is formed and quenched by cold dies simultaneously. The IHTC should therefore be identified and used in FE models to improve the accuracy of simulation results of hot stamping processes. In this work, a hot stamping simulator was designed and assembled in a Gleeble 3800 thermo-mechanical testing system and a FE model was built in PAM-STAMP to determine the IHTC value between a hot aluminium alloy 7075 blank and cold dies. The IHTC was determined at different contact pressures under both dry and lubricated (Omega-35 conditions. In addition, a model to calculate the IHTC value at different contact pressures and area densities of lubricant was developed for the hot stamping process.

  10. Hot cell renovation in the spent fuel conditioning process facility at the Korea Atomic Energy Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Seung Nam; Lee, Jong Kwang; Park, Byung Suk; Cho, Il Je; Kim, Ki Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The advanced spent fuel conditioning process facility (ACPF) of the irradiated materials examination facility (IMEF) at the Korea Atomic Energy Research Institute (KAERI) has been renovated to implement a lab scale electrolytic reduction process for pyroprocessing. The interior and exterior structures of the ACPF hot cell have been modified under the current renovation project for the experimentation of the electrolytic reduction process using spent nuclear fuel. The most important aspect of this renovation was the installation of the argon compartment within the hot cell. For the design and system implementation of the argon compartment system, a full-scale mock-up test and a three-dimensional (3D) simulation test were conducted in advance. The remodeling and repairing of the process cell (M8a), the maintenance cell (M8b), the isolation room, and their utilities were also planned through this simulation to accommodate the designed argon compartment system. Based on the considered refurbishment workflow, previous equipment in the M8 cell, including vessels and pipes, were removed and disposed of successfully after a zoning smear survey and decontamination, and new equipment with advanced functions and specifications were installed in the hot cell. Finally, the operating area and isolation room were also refurbished to meet the requirements of the improved hot cell facility.

  11. OCCUPATIONAL ACCIDENTS AS INDICATORS OF INADEQUATE WORK CONDITIONS AND WORK ENVIRONMENT

    OpenAIRE

    Petar Babović

    2009-01-01

    Occupational accidents due to inadequate working conditions and work environment present a major problem in highly industrialised countries, as well as in developing ones. Occupational accidents are a regular and accompanying phenomenon in all human activities and one of the main health related and economic problems in modern societies.The aim of this study is the analysis of the connections of unfavourable working conditions and working environment on occupational accidents. Occurrence of oc...

  12. Hot Spots and Hot Moments of Nitrogen in a Riparian Corridor

    Science.gov (United States)

    Dwivedi, Dipankar; Arora, Bhavna; Steefel, Carl I.; Dafflon, Baptiste; Versteeg, Roelof

    2018-01-01

    We use 3-D high-resolution reactive transport modeling to investigate whether the spatial distribution of organic-carbon-rich and chemically reduced sediments located in the riparian zone and temporal variability in groundwater flow direction impact the formation and distribution of nitrogen hot spots (regions that exhibit higher reaction rates when compared to other locations nearby) and hot moments (times that exhibit high reaction rates as compared to longer intervening time periods) within the Rifle floodplain in Colorado. Groundwater flows primarily toward the Colorado River from the floodplain but changes direction at times of high river stage. The result is that oxic river water infiltrates the Rifle floodplain during these relatively short-term events. Simulation results indicate that episodic rainfall in the summer season leads to the formation of nitrogen hot moments associated with Colorado River rise and resulting river infiltration into the floodplain. The results further demonstrate that the naturally reduced zones (NRZs) present in sediments of the Rifle floodplain have a higher potential for nitrate removal, approximately 70% greater than non-NRZs for typical hydrological conditions. During river water infiltration, nitrate reduction capacity remains the same within the NRZs, however, these conditions impact non-NRZs to a greater extent (approximately 95% less nitrate removal). Model simulations indicate chemolithoautotrophs are primarily responsible for the removal of nitrate in the Rifle floodplain. These nitrogen hot spots and hot moments are sustained by microbial respiration and the chemolithoautotrophic oxidation of reduced minerals in the riparian zone.

  13. Poor working conditions and work stress among Canadian sex workers.

    Science.gov (United States)

    Duff, P; Sou, J; Chapman, J; Dobrer, S; Braschel, M; Goldenberg, S; Shannon, K

    2017-10-01

    While sex work is often considered the world's oldest profession, there remains a dearth of research on work stress among sex workers (SWs) in occupational health epidemiological literature. A better understanding of the drivers of work stress among SWs is needed to inform sex work policy, workplace models and standards. To examine the factors that influence work stress among SWs in Metro Vancouver. Analyses drew from a longitudinal cohort of SWs, known as An Evaluation of Sex Workers' Health Access (AESHA) (2010-14). A modified standardized 'work stress' scale, multivariable linear regression with generalized estimating equations was used to longitudinally examine the factors associated with work stress. In multivariable analysis, poor working conditions were associated with increased work stress and included workplace physical/sexual violence (β = 0.18; 95% confidence interval (CI) 0.06, 0.29), displacement due to police (β = 0.26; 95% CI 0.14, 0.38), working in public spaces (β = 0.73; 95% CI 0.61, 0.84). Older (β = -0.02; 95% CI -0.03, -0.01) and Indigenous SWs experienced lower work stress (β = -0.25; 95% CI -0.43, -0.08), whereas non-injection (β = 0.32; 95% CI 0.14, 0.49) and injection drug users (β = 0.17; 95% CI 0.03, 0.31) had higher work stress. Vancouver-based SWs' work stress was largely shaped by poor work conditions, such as violence, policing, lack of safe workspaces. There is a need to move away from criminalized approaches which shape unsafe work conditions and increase work stress for SWs. Policies that promote SWs' access to the same occupational health, safety and human rights standards as workers in other labour sectors are also needed. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  14. Work on the hot atom chemistry at the Institute of Nuclear Sciences Boris Kidric, Vinca, Yugoslavia

    International Nuclear Information System (INIS)

    Veljkovic, S.

    1969-01-01

    A survey of work on hot atom chemistry from the establishment of the Institute up to now, where the role of Prof. P. Savic, should be specially emphasized, is given. The investigations in this domain during the first period, were directed to solve various problems in production of radioactive isotopes. Today these investigations are closely associated with the work in radiochemistry, physical chemistry of liquid and solid systems and fast reaction kinetics improving the development of these branches (author) [sr

  15. Work performance decrements are associated with Australian working conditions, particularly the demand to work longer hours.

    Science.gov (United States)

    Holden, Libby; Scuffham, Paul A; Hilton, Michael F; Vecchio, Nerina N; Whiteford, Harvey A

    2010-03-01

    To demonstrate the importance of including a range of working conditions in models exploring the association between health- and work-related performance. The Australian Work Outcomes Research Cost-benefit study cross-sectional screening data set was used to explore health-related absenteeism and work performance losses on a sample of approximately 78,000 working Australians, including available demographic and working condition factors. Data collected using the World Health Organization Health and Productivity Questionnaire were analyzed with negative binomial logistic regression and multinomial logistic regressions for absenteeism and work performance, respectively. Hours expected to work, annual wage, and job insecurity play a vital role in the association between health- and work-related performance for both work attendance and self-reported work performance. Australian working conditions are contributing to both absenteeism and low work performance, regardless of health status.

  16. Assessment of the relationship between physical working conditions and different levels of work ability.

    Science.gov (United States)

    Attarchi, Mirsaeed; Ghaffari, Mostafa; Abdi, Alireza; Mirzamohammadi, Elham; Seyedmehdi, Seyed Mohammad; Rahimpour, Farzaneh; Fazlalizadeh, Maryam; Mohammadi, Saber

    2014-04-20

    Early leaving of workplace by work forces is one of the fundamental problems worldwide. Maintenance and enhancement of employees work ability are important for raising productivity. This study investigated the relationship between work ability index and physical working conditions and was carried out in 2013 on 641 workers at a manufacturing plant in Tehran. Work ability was assessed by the questionnaire of work ability index and the participants were classified into four work ability groups of poor, moderate, good, and excellent. Physical working conditions were evaluated by the MUSIC-Norrtalje questionnaire and the participants were classified into two groups with proper and poor physical working conditions. The mean score of work ability questionnaire was 42.40; and 2.5% (16 persons), 9.2% (59 persons), 38.2% (245 persons), and 50.1% (321 persons) of the participants were in poor, moderate, good, and excellent work ability groups, respectively. The mean score of physical working conditions questionnaire was 20.06. The results of logistic regression analysis showed that even after adjusting the confounding variables, a significant correlation existed between work ability and physical working conditions (p working conditions such as awkward postures, repetitive movements, load lifting, exposure to whole body vibration and so on with work ability. Therefore it seems that enhancement of the quality of physical working conditions may increase work ability.

  17. Investigation of the fabrication process of hot-worked stainless-steel and Mo sheathed PbMo6 S8 wires

    International Nuclear Information System (INIS)

    Yamasaki, H.; Kimura, Y.

    1988-01-01

    Stainless-steel and Mo sheathed PbMo 6 S 8 wires have been fabricated by hot working from modified PbS, Mo, and MoS 2 mixed powders which were prepared by reacting Pb, Mo, and S at 530 0 C. Critical current densities were investigated for different preparation conditions, and it is revealed that obtaining continuous current path between PbMo 6 S 8 grains is the most important factor to achieve high critical current density. The J/sub c/ value of 2.8 x 10 4 Acm 2 (8 T), 7.8 x 10 3 Acm 2 (15 T), and 1.3 x 10 3 Acm 2 (23 T) was observed for the PbMo 6 S/sub 7.0/ wire heat treated at 700 0 C.copic

  18. To built a solar hot water heater to work the sustainability problem

    Directory of Open Access Journals (Sweden)

    Carretero Gómez, María Begoña

    2012-01-01

    Full Text Available We are commemorating the Education Decade for Sustainable Development. If we want to create positive towards our environment and its sustainable development we have to begin working at school. It is necessary to show our students what problems of the environment are and which solutions can be adopted. That is the reason we have planned this activity in our secondary school. We do think that by doing daily activities we have a good opportunity to fulfil this goal. An example of such experiences is the fabrication of a solar hot water heater to make them and their families more environment conscience.

  19. Working conditions, work style, and job satisfaction among Albanian teachers

    Science.gov (United States)

    Kloep, Marion; Tarifa, Fatos

    1994-03-01

    For the first time in Albania, a large-scale study investigating teachers' working conditions was conducted. 349 teachers from many parts of the country and from all school levels answered an extensive questionnaire, providing a comprehensive description of their working situation. As data for parts of the study exist from the USA, Germany, Singapore, England, and Poland, results could be discussed in comparison to the conditions in these countries, showing that self-reported job satisfaction and engagement in effective classroom practices is relatively high among Albanian teachers, while the economic and physical conditions are bad. Stepwise regression analyses reveal that the items measuring professional autonomy account for a considerable part of the variance of the job satisfaction measure; while work efficiency is mainly predicted by items measuring social support and, again, professional autonomy.

  20. Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

    Science.gov (United States)

    Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

    2015-01-01

    This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological responses

  1. Coulomb explosion of “hot spot”

    Energy Technology Data Exchange (ETDEWEB)

    Oreshkin, V. I., E-mail: oreshkin@ovpe.hcei.tsc.ru [Institute of High Current Electrons, SB, RAS, Tomsk (Russian Federation); Tomsk Polytechnic University, Tomsk (Russian Federation); Oreshkin, E. V. [P. N. Lebedev Physical Institute, RAS, Moscow (Russian Federation); Chaikovsky, S. A. [Institute of High Current Electrons, SB, RAS, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, RAS, Moscow (Russian Federation); Institute of Electrophysics, UD, RAS, Ekaterinburg (Russian Federation); Artyomov, A. P. [Institute of High Current Electrons, SB, RAS, Tomsk (Russian Federation)

    2016-09-15

    The study presented in this paper has shown that the generation of hard x rays and high-energy ions, which are detected in pinch implosion experiments, may be associated with the Coulomb explosion of the hot spot that is formed due to the outflow of the material from the pinch cross point. During the process of material outflow, the temperature of the hot spot plasma increases, and conditions arise for the plasma electrons to become continuously accelerated. The runaway of electrons from the hot spot region results in the buildup of positive space charge in this region followed by a Coulomb explosion. The conditions for the hot spot plasma electrons to become continuously accelerated have been revealed, and the estimates have been obtained for the kinetic energy of the ions generated by the Coulomb explosion.

  2. Coulomb explosion of “hot spot”

    International Nuclear Information System (INIS)

    Oreshkin, V. I.; Oreshkin, E. V.; Chaikovsky, S. A.; Artyomov, A. P.

    2016-01-01

    The study presented in this paper has shown that the generation of hard x rays and high-energy ions, which are detected in pinch implosion experiments, may be associated with the Coulomb explosion of the hot spot that is formed due to the outflow of the material from the pinch cross point. During the process of material outflow, the temperature of the hot spot plasma increases, and conditions arise for the plasma electrons to become continuously accelerated. The runaway of electrons from the hot spot region results in the buildup of positive space charge in this region followed by a Coulomb explosion. The conditions for the hot spot plasma electrons to become continuously accelerated have been revealed, and the estimates have been obtained for the kinetic energy of the ions generated by the Coulomb explosion.

  3. The evolution of the monthly hydrograph under hot drought conditions in the Southwest US

    Science.gov (United States)

    Solander, K.; Bennett, K. E.; Middleton, R. S.

    2017-12-01

    Hydrology will undergo unprecedented changes in the 21st century. In particular, the emergence of the hot drought—an extraordinary combination of recurring droughts coupled with warmer temperatures—will lead to more frequent and widespread droughts of longer duration. This will transform the natural and engineered landscape, with millions of dollars in critical infrastructure and investments in agriculture, municipalities, and energy-water supplies at stake. Here, we investigate how the monthly hydrograph will evolve under hot drought conditions by examining the response of streamflow under historic droughts overlaid with expected temperature increases in the coming decades. We use a suite of Global Climate Models and two emission scenarios coupled to the Variable Infiltration Capacity hydrology model to evaluate these changes under different levels of warming using various sub-basins within the Colorado River Basin as a test case. Results indicate a substantial change in both magnitude (up to 40% decrease) and timing (greater than one-month earlier) in peak flows with spatial differences strongly influenced by elevation. Findings indicate these shifts are being driven by changing snow and snowmelt patterns. Such changes are anticipated to have a substantial impact on food, energy, and water resources within the basin and are important to understand in advance given that they represent the extreme range of conditions likely to occur so we can improve the management of this resource and adapt to these changes during critical periods.

  4. CFD analysis of hot spot formation through a fixed bed reactor of Fischer-Tropsch synthesis

    Directory of Open Access Journals (Sweden)

    Hamed Aligolzadeh

    2015-12-01

    Full Text Available One of the interesting methods for conversion of synthesis gas to heavy hydrocarbons is Fischer–Tropsch process. The process has some bottlenecks, such as hot spot formation and low degree of conversion. In this work, computational fluid dynamics technique was used to simulate conversion of synthetic gas and product distribution. Also, hot spot formation in the catalytic fixed-bed reactor was investigated in several runs. Simulation results indicated that hot spot formation occurred more likely in the early and middle part of reactor due to high reaction rates. Based on the simulation results, the temperature of hot spots increased with increase in the inlet temperature as well as pressure. Among the many CFD runs conducted, it is found that the optimal temperature and pressure for Fischer–Tropsch synthesis are 565 K and 20 bar, respectively. As it seems that the reactor shall work very well under optimal conditions, the reaction rates and catalyst duration would simultaneously be maximum .

  5. Assessment of monitored energy use and thermal comfort conditions in mosques in hot-humid climates

    Energy Technology Data Exchange (ETDEWEB)

    Al-Homoud, Mohammad S.; Abdou, Adel A.; Budaiwi, Ismail M. [Architectural Engineering Department, KFUPM, Dhahran 31261 (Saudi Arabia)

    2009-06-15

    In harsh climatic regions, buildings require air-conditioning in order to provide an acceptable level of thermal comfort. In many situations buildings are over cooled or the HVAC system is kept running for a much longer time than needed. In some other situations thermal comfort is not achieved due to improper operation practices coupled with poor maintenance and even lack it, and consequently inefficient air-conditioning systems. Mosques represent one type of building that is characterized by their unique intermittent operating schedule determined by prayer times, which vary continuously according to the local solar time. This paper presents the results of a study designed to monitor energy use and thermal comfort conditions of a number of mosques in a hot-humid climate so that both energy efficiency and the quality of thermal comfort conditions especially during occupancy periods in such intermittently operated buildings can be assessed accurately. (author)

  6. The Current Working Conditions in Ugandan Apparel Assembly Plants

    Directory of Open Access Journals (Sweden)

    Mike Tebyetekerwa

    2017-12-01

    Full Text Available Background: The present rapid shift of industrialization from developed to developing countries requires developing countries to understand issues related to work organization, management, and working conditions. There are many factors slackening production, of which working conditions is part. A complete inquiry into the workers' working conditions can enable managements to reduce risks in the workplaces and improve productivity. Understanding and awareness of the benefits of workplace research and a probe into the working conditions in the Ugandan apparel assembly plants are urgently required. Methods: A total of 103 (70 women and 33 men workers from five different plants were interviewed. Together with the top management of various plants, questionnaires about the workers' opinions of their physical working conditions were prepared. Data was collected using two methods: (1 questionnaire; and (2 observation of the workers during their work. Results: The results indicated that poor plant working conditions were mainly contributed by the workers' social factors and the management policies. Conclusion: The government, together with the management, should work to improve the working conditions in the apparel assembly plants, as it greatly affects both. Keywords: apparel assembly plants, ergonomics, musculoskeletal disorders, Uganda, working conditions

  7. Working conditions in nuclear reprocessing plants

    International Nuclear Information System (INIS)

    1986-12-01

    In the context of the project, the working conditions of workers in reprocessing plants and associated plant of the fuel circuit were thoroughly examined. The project design and course of the project are a good example of a precautionary technical assessment necessary for social policy reasons, which is in the public interest and is required by the Trade Unions. By working conditions, one means the whole set of scientific/technical, medical, legal, economic and political conditions for the permanent employment of workers in reprocessing plants including the associated parts of the fuel circuit. (orig./HP) [de

  8. Evaluation of Three Hydration Strategies in Detection Dogs Working in a Hot Environment

    Directory of Open Access Journals (Sweden)

    Cynthia M. Otto

    2017-10-01

    Full Text Available Physical activity in hot environments can increase the risk of heat stress or heat stroke in dogs. Heat tolerance is influenced by acclimatization to the environment, physical fitness, and hydration state. Three common strategies to promote hydration in working dogs are free access to water (W, oral electrolyte solutions (OESs, and administration of subcutaneous fluids (SQs. None of these methods have been compared for safety or efficacy in a working environment. In a cross-over design, seven vehicle-screening canines were randomly assigned to each of the three hydration strategies during working shifts at the Sarita, TX checkpoint. Physical, behavioral, and biochemical parameters were collected before, during, and after a work shift (mean 5.7 ± 0.8 h. Dogs were given 10 mL/kg oral W, 10 mL/kg chicken flavored OES, or 15 mL/kg of SQs initially followed by controlled access to W or OES. The dogs drank 15.61 ± 4.47 mL/kg/h of W and OES when in the OES group, compared to 7.04 ± 3.42 and 5.56 ± 4.40 mL of W, for the W and SQ groups, respectively. The median environmental temperature was 84.8°F (29.3°C. The median humidity was 70%. Based on mixed effects linear modeling, dogs in the OES and SQ groups had significantly higher total CO2, and lower packed cell volume and total plasma protein at the end of the day. Creatinine increased a small but significant amount in the SQ group and decreased in the OES group. Searching behaviors were independent of hydration strategy but highly related to the dog specific factors of sex, breed, and activity level. Under conditions of controlled activity in moderate heat and humidity, dogs accustomed to the work and the environment were more likely to increase fluid consumption and hydration when provided a flavored OES. Potential benefits of OES and SQ were indirect and no adverse effects were documented for any of the hydration strategies tested.

  9. Experimental and numerical approaches to studying hot cracking in stainless steel welds

    International Nuclear Information System (INIS)

    Le, Minh

    2014-01-01

    This work concerns experimental and numerical approaches to studying hot cracking in welds in stainless steel. Metallurgical weldability of two filler products used for the welding of an AISI-316L(N) austenitic stainless steel grade is evaluated. These filler metals are distinguished by their solidification microstructures: austeno-ferritic for the 19Cr-12Ni-2Mo grade and austenitic for the 19-15H Thermanit grade. The study of weldability concerns the assessment of the susceptibility to hot cracking of these three alloys, the proposition of a hot cracking criterion, and the evaluation of its transferability to structure-scale tests. Hot cracks are material separations occurring at high temperatures along the grain boundaries (dendrite boundaries), when the level of strain and the strain rate exceed a certain level. The hot cracks studied are formed during solidification from the liquid phase of weld metals. The bibliography study brings to the fore the complexity of initiation and propagation mechanisms of these material separations. Three types of tests are studied in this work: hot cracking tests, such as trapezoidal and Varestraint tests, allowing to initiate the phenomenon in controlled experimental conditions, and tests on the Gleeble thermomechanical simulator for thermomechanical (materials behavior laws, fracture properties) and metallurgical (brittle temperature range (BTR), evolution of delta ferrite) characterizations of the alloys. All these tests on the three materials were analyzed via numerical modeling and simulations implemented in the Cast3M finite element code in order to bring out a thermomechanical hot cracking criterion. (author) [fr

  10. Safety distance for preventing hot particle ignition of building insulation materials

    Directory of Open Access Journals (Sweden)

    Jiayun Song

    2014-01-01

    Full Text Available Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere aluminum particles with the same initial velocities and diameters, the horizontal and vertical distances traveled by particles with higher initial temperatures were higher. Smaller particles traveled farther when other conditions were the same. The critical temperature for an aluminum particle to ignite rigid polyurethane foam increased rapidly with the decrease of particle diameter. The horizontal and vertical safety distances were closely related to the initial temperature, diameter and initial velocity of particles. These results could help update the safety provision of firework display.

  11. Cause of Damage. Hot cracking; Schadensursache Heissrissigkeit

    Energy Technology Data Exchange (ETDEWEB)

    Wader, Therese [BENTELER Steel/Tube GmbH, Paderborn (Germany). Vorentwicklung Werkstoffe

    2016-10-15

    Under certain conditions, Nb-containing stainless steels are susceptible to hot cracking. Such conditions include low melting phases on the grain boundaries, a coarse-grained microstructure such as cast structures, microstructure orientations towards the main tensile direction and high processing temperatures. The case of damage was characterized using metallographic and microanalytical methods. In the laboratory, the critical temperature range for the formation of hot cracks could furthermore specifically be localized under mechanical stresses by means of a dilatometer aiming at clearly verifying the cause of the damage, namely ''hot cracks''.

  12. The Current Working Conditions in Ugandan Apparel Assembly Plants.

    Science.gov (United States)

    Tebyetekerwa, Mike; Akankwasa, Nicholus Tayari; Marriam, Ifra

    2017-12-01

    The present rapid shift of industrialization from developed to developing countries requires developing countries to understand issues related to work organization, management, and working conditions. There are many factors slackening production, of which working conditions is part. A complete inquiry into the workers' working conditions can enable managements to reduce risks in the workplaces and improve productivity. Understanding and awareness of the benefits of workplace research and a probe into the working conditions in the Ugandan apparel assembly plants are urgently required. A total of 103 (70 women and 33 men) workers from five different plants were interviewed. Together with the top management of various plants, questionnaires about the workers' opinions of their physical working conditions were prepared. Data was collected using two methods: (1) questionnaire; and (2) observation of the workers during their work. The results indicated that poor plant working conditions were mainly contributed by the workers' social factors and the management policies. The government, together with the management, should work to improve the working conditions in the apparel assembly plants, as it greatly affects both.

  13. A comparative simple method for human bioclimatic conditions applied to seasonally hot/warm cities of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda Martinez, A. [Universidad Veracruzana, Xalapa, Veracruz (Mexico); Garcia Cueto, O.R. [Universidad Autonoma de Baja California, Mexicali, B.C. (Mexico)

    2002-01-01

    The climate of a region is an environmental resource with important implications for things such as thermal comfort, health and productivity of the population. In this work, the bioclimatic comfort was evaluated for seven seasonally warm/hot cities of Mexico by means of the following current indexes: Discomfort Index, Enthalpy Index and Heat Strain Index. Also, the periods during which it is necessary to use air conditioning in the studied cities were calculated from estimated global radiation and hourly data of temperature and relative humidity which made it possible to establish them with high precision. Finally, the useful of the Heat Strain Index is shown. It is a simple index needing available meteorological data to compare bioclimatic conditions of similar sites. [Spanish] El clima regional tiene implicaciones en el confort, la salud y la productividad de la poblacion. En este articulo se presentan las evaluaciones bioclimaticas comparativas de siete ciudades calidas de Mexico. Se aplicaron los indices bioclimaticos de disconfort, entalpia y esfuerzo frente al calor. Se calcularon los periodos para los cuales es necesario el uso de aire acondicionado, a partir de estimaciones de radiacion solar global y de temperatura y humedad horarias medias mensuales. Finalmente se muestra la utilidad y calidad del Indice de esfuerzo frente al calor, el cual requiere solo de datos climatologicos comunes para poder comparar condiciones bioclimaticas de sitios similares.

  14. TWRS tank waste pretreatment process development hot test siting report

    International Nuclear Information System (INIS)

    Howden, G.F.; Banning, D.L.; Dodd, D.A.; Smith, D.A.; Stevens, P.F.; Hansen, R.I.; Reynolds, B.A.

    1995-02-01

    This report is the sixth in a series that have assessed the hot testing requirements for TWRS pretreatment process development and identified the hot testing support requirements. This report, based on the previous work, identifies specific hot test work packages, matches those packages to specific hot cell facilities, and provides recommendations of specific facilities to be employed for the pretreatment hot test work. Also identified are serious limitations in the tank waste sample retrieval and handling infrastructure. Recommendations are provided for staged development of 500 mL, 3 L, 25 L and 4000 L sample recovery systems and specific actions to provide those capabilities

  15. Application of heat treatment and hot extrusion processes to improve mechanical properties of the AZ91 alloy

    Directory of Open Access Journals (Sweden)

    T. Reguła

    2010-04-01

    Full Text Available The main aim of this paper is to evaluate the effects of hot working (extrusion and hest treatment on room temperature mechanical properties of magnesium-based AZ91 alloy. The results were compared with as-cast condition. The examined material had been obtained by gravity casting to permanent moulds and subsequently subjected to heat treatment and/or processed by extrusion at 648 K. Microstructural and mechanical properties of properly prepared specimens were studied. Rm, Rp02 and A5 were determined from tensile tests. Brinell hardness tests were also conducted. The research has shown that hot working of AZ91 alloy provides high mechanical properties unattainable by cast material subjected to heat-treatment. The investigated alloy subjected to hot working and subsequently heat-treated has doubled its strength and considerably improved the elongation - compared with the as-cast material.

  16. A comparison of spent fuel shipping cask response to 10 CFR 71 normal conditions and realistic hot day extremes

    International Nuclear Information System (INIS)

    Manson, S.J.; Gianoulakis, S.E.

    1994-04-01

    An examination of the effect of a realistic (though conservative) hot day environment on the thermal transient behavior of spent fuel shipping casks is made. These results are compared to those that develop under the prescribed normal thermal condition of 10 CFR 71. Of specific concern are the characteristics of propagating thermal waves, which are set up by diurnal variations of temperature and insolation in the outdoor environment. In order to arrive at a realistic approximation of these variations on a conservative hot day, actual temperature and insolation measurements have been obtained from the National Climatic Data Center (NCDC) for representatively hot and high heat flux days. Thus, the use of authentic meteorological data ensures the realistic approach sought. Further supporting the desired realism of the modeling effort is the use of realistic cask configurations in which multiple laminations of structural, shielding, and other materials are expected to attenuate the propagating thermal waves. The completed analysis revealed that the majority of wall temperatures, for a wide variety of spent fuel shipping cask configurations, fall well below those predicted by enforcement of the regulatory environmental conditions of 10 CFR 71. It was found that maximum temperatures at the cask surface occasionally lie above temperatures predicted under the prescribed regulatory conditions. However, the temperature differences are small enough that the normal conservative assumptions that are made in the course of typical cask evaluations should correct for any potential violations. The analysis demonstrates that diurnal temperature variations that penetrate the cask wall all have maxima substantially less than the corresponding regulatory solutions. Therefore it is certain that vital cask components and the spent fuel itself will not exceed the temperatures calculated by use of the conditions of 10 CFR 71

  17. [Nursing workloads and working conditions: integrative review].

    Science.gov (United States)

    Schmoeller, Roseli; Trindade, Letícia de Lima; Neis, Márcia Binder; Gelbcke, Francine Lima; de Pires, Denise Elvira Pires

    2011-06-01

    This study reviews theoretical production concerning workloads and working conditions for nurses. For that, an integrative review was carried out using scientific articles, theses and dissertations indexed in two Brazilian databases, Virtual Health Care Library (Biblioteca Virtual de Saúde) and Digital Database of Dissertations (Banco Digital de Teses), over the last ten years. From 132 identified studies, 27 were selected. Results indicate workloads as responsible for professional weariness, affecting the occurrence of work accidents and health problems. In order to adequate workloads studies indicate some strategies, such as having an adequate numbers of employees, continuing education, and better working conditions. The challenge is to continue research that reveal more precisely the relationships between workloads, working conditions, and health of the nursing team.

  18. The effects of composition and thermal path on hot ductility of forging steels

    Science.gov (United States)

    Connolly, Brendan M.

    This work examines the effects of composition and thermal path on the hot ductility of several forging steels with varied aluminum and nitrogen content. The primary mechanisms and controlling factors related to hot ductility are identified with a focus on the role of precipitates and segregation. The unique thermal paths and solidification structures of large cross-section forging ingots are discussed. Hot ductility testing is performed in a manner that approximates industrial conditions experienced by large cross-section forging ingots. A computer model for precipitation of aluminum nitride and vanadium nitride in austenite is presented. Industrial material is examined for comparison to experimental findings. It is found that increased aluminum and nitrogen content coarsens the as-solidified structure. The combined effects of microsegregation and uphill diffusion during deformation allow for carbide precipitation at prior austenite grain boundaries which reduces the hot ductility.

  19. Effect of biomimetic non-smooth unit morphology on thermal fatigue behavior of H13 hot-work tool steel

    Science.gov (United States)

    Meng, Chao; Zhou, Hong; Cong, Dalong; Wang, Chuanwei; Zhang, Peng; Zhang, Zhihui; Ren, Luquan

    2012-06-01

    The thermal fatigue behavior of hot-work tool steel processed by a biomimetic coupled laser remelting process gets a remarkable improvement compared to untreated sample. The 'dowel pin effect', the 'dam effect' and the 'fence effect' of non-smooth units are the main reason of the conspicuous improvement of the thermal fatigue behavior. In order to get a further enhancement of the 'dowel pin effect', the 'dam effect' and the 'fence effect', this study investigated the effect of different unit morphologies (including 'prolate', 'U' and 'V' morphology) and the same unit morphology in different sizes on the thermal fatigue behavior of H13 hot-work tool steel. The results showed that the 'U' morphology unit had the optimum thermal fatigue behavior, then the 'V' morphology which was better than the 'prolate' morphology unit; when the unit morphology was identical, the thermal fatigue behavior of the sample with large unit sizes was better than that of the small sizes.

  20. Archaeal Nitrification in Hot Springs

    Science.gov (United States)

    Richter, A.; Daims, H.; Reigstad, L.; Wanek, W.; Wagner, M.; Schleper, C.

    2006-12-01

    Biological nitrification, i.e. the aerobic conversion of ammonia to nitrate via nitrite, is a major component of the global nitrogen cycle. Until recently, it was thought that the ability to aerobically oxidize ammonia was confined to bacteria of the phylum Proteobacteria. However, it has recently been shown that Archaea of the phylum Crenarchaeota are also capable of ammonia oxidation. As many Crenarchaeota are thermophilic or hyperthermophilic, and at least some of them are capable of ammonia oxidation we speculated on the existence of (hyper)thermophilic ammonia-oxidizing archaea (AOA). Using PCR primers specifically targeting the archaeal ammonia monooxygenase (amoA) gene, we were indeed able to confirm the presence of such organisms in several hot springs in Reykjadalur, Iceland. These hot springs exhibited temperatures well above 80 °C and pH values ranging from 2.0 to 4.5. To proof that nitrification actually took place under these extreme conditions, we measured gross nitrification rates by the isotope pool dilution method; we added 15N-labelled nitrate to the mud and followed the dilution of the label by nitrate production from ammonium either in situ (incubation in the hot spring) or under controlled conditions in the laboratory (at 80 °C). The nitrification rates in the hot springs ranged from 0.79 to 2.22 mg nitrate-N per L of mud and day. Controls, in which microorganisms were killed before the incubations, demonstrated that the nitrification was of biological origin. Addition of ammonium increased the gross nitrification rate approximately 3-fold, indicating that the nitrification was ammonium limited under the conditions used. Collectively, our study provides evidence that (1) AOA are present in hot springs and (2) that they are actively nitrifying. These findings have major implications for our understanding of nitrogen cycling of hot environments.

  1. Evaluation of wet bulb globe temperature index for estimation of heat strain in hot/humid conditions in the Persian Gulf.

    Science.gov (United States)

    Dehghan, Habibolah; Mortazavi, Seyed Bagher; Jafari, Mohammad J; Maracy, Mohammad R

    2012-12-01

    Heat exposure among construction workers in the Persian Gulf region is a serious hazard for health. The aim of this study was to evaluate the performance of wet bulb globe temperature (WBGT) Index for estimation of heat strain in hot/humid conditions by the use of Physiological Strain Index (PSI) as the gold standard. This cross-sectional study was carried out on 71 workers of two Petrochemical Companies in South of Iran in 2010 summer. The WBGT index, heart rate, and aural temperature were measured by Heat Stress Monitor (Casella Microtherm WBGT), Heart Rate Monitor (Polar RS100), and Personal Heat Strain Monitor (Questemp II), respectively. The obtained data were analyzed with descriptive statistics and Pearson correlation analysis. The mean (SD) of WBGT values was 33.1 (2.7). The WBGT values exceed from American Conference of Governmental Industrial Hygienists (ACGIH) standard (30°C) in 96% work stations, whereas the PSI values were more than 5.0 (moderate strain) in 11% of workstations. The correlation between WBGT and PSI values was 0.61 (P = 0.001). When WBGT values were less and more than 34°C, the mean of PSI was 2.6 (low strain) and 5.2 (moderate strain), respectively. In the Persian Gulf weather, especially hot and humid in the summer months, due to the WBGT values exceeding 30°C (in 96% of cases) and weak correlation between WBGT and PSI, the work/rest cycles of WBGT Index is not suitable for heat stress management. Therefore, in Persian Gulf weather, heat stress evaluation based on physiologic variables may have higher validity than WBGT index.

  2. Evaluation of wet bulb globe temperature index for estimation of heat strain in hot/humid conditions in the Persian Gulf

    Directory of Open Access Journals (Sweden)

    Habibolah Dehghan

    2012-01-01

    Full Text Available Background: Heat exposure among construction workers in the Persian Gulf region is a serious hazard for health. The aim of this study was to evaluate the performance of wet bulb globe temperature (WBGT Index for estimation of heat strain in hot/humid conditions by the use of Physiological Strain Index (PSI as the gold standard. Material and Methods : This cross-sectional study was carried out on 71 workers of two Petrochemical Companies in South of Iran in 2010 summer. The WBGT index, heart rate, and aural temperature were measured by Heat Stress Monitor (Casella Microtherm WBGT, Heart Rate Monitor (Polar RS100, and Personal Heat Strain Monitor (Questemp II, respectively. The obtained data were analyzed with descriptive statistics and Pearson correlation analysis. Results: The mean (SD of WBGT values was 33.1 (2.7. The WBGT values exceed from American Conference of Governmental Industrial Hygienists (ACGIH standard (30°C in 96% work stations, whereas the PSI values were more than 5.0 (moderate strain in 11% of workstations. The correlation between WBGT and PSI values was 0.61 ( P = 0.001. When WBGT values were less and more than 34°C, the mean of PSI was 2.6 (low strain and 5.2 (moderate strain, respectively. Conclusion: In the Persian Gulf weather, especially hot and humid in the summer months, due to the WBGT values exceeding 30°C (in 96% of cases and weak correlation between WBGT and PSI, the work/rest cycles of WBGT Index is not suitable for heat stress management. Therefore, in Persian Gulf weather, heat stress evaluation based on physiologic variables may have higher validity than WBGT index.

  3. Statistical hot spot analysis of reactor cores

    International Nuclear Information System (INIS)

    Schaefer, H.

    1974-05-01

    This report is an introduction into statistical hot spot analysis. After the definition of the term 'hot spot' a statistical analysis is outlined. The mathematical method is presented, especially the formula concerning the probability of no hot spots in a reactor core is evaluated. A discussion with the boundary conditions of a statistical hot spot analysis is given (technological limits, nominal situation, uncertainties). The application of the hot spot analysis to the linear power of pellets and the temperature rise in cooling channels is demonstrated with respect to the test zone of KNK II. Basic values, such as probability of no hot spots, hot spot potential, expected hot spot diagram and cumulative distribution function of hot spots, are discussed. It is shown, that the risk of hot channels can be dispersed equally over all subassemblies by an adequate choice of the nominal temperature distribution in the core

  4. Effects of evaporative cooling on reproductive performance and milk production of dairy cows in hot wet conditions

    Science.gov (United States)

    Khongdee, S.; Chaiyabutr, N.; Hinch, G.; Markvichitr, K.; Vajrabukka, C.

    2006-05-01

    Fourteen animals of second and third lactation of Thai Friesian crossbred cows (87.5% Friesian × 12.5% Bos indicus) located at Sakol Nakhon Research and Breeding Centre, Department of Livestock Development, Ministry of Agriculture and Cooperatives, were divided randomly into two groups of seven each to evaluate the effects of evaporative cooling on reproductive and physiological traits under hot, humid conditions. Results indicated that installation of evaporating cooling in the open shed gave a further improvement in ameliorating heat stress in dairy cows in hot-wet environments by utilising the low humidity conditions that naturally occur during the day. The cows housed in an evaporatively cooled environment had both a rectal temperature and respiration rate (39.09°C, 61.39 breaths/min, respectively) significantly lower than that of the non-cooled cows (41.21°C; 86.87 breaths/min). The former group also had higher milk yield and more efficient reproductive performance (pregnancy rate and reduced days open) than the latter group. It is suggested that the non-evaporatively cooled cows did not gain benefit from the naturally lower heat stress during night time.

  5. Teachers' Working Conditions. Findings from "The Condition of Education, 1996," No. 7.

    Science.gov (United States)

    Choy, Susan P.

    Working conditions play an important role in a school's ability to attract, develop, and retain effective teachers. Data presented here describe a number of aspects of teachers' working conditions, including workload, compensation, school and district support for teachers' professional development, school decision making, school safety, student…

  6. MIS hot electron devices for enhancement of surface reactivity by hot electrons

    DEFF Research Database (Denmark)

    Thomsen, Lasse Bjørchmar

    A Metal-Insulator-Semiconductor (MIS) based device is developed for investigation of hot electron enhanced chemistry. A model of the device is presented explaining the key concepts of the functionality and the character- istics. The MIS hot electron emitter is fabricated using cleanroom technology...... and the process sequence is described. An Ultra High Vacuum (UHV) setup is modified to facilitate experiments with electron emission from the MIS hot electron emitters and hot electron chemistry. Simulations show the importance of keeping tunnel barrier roughness to an absolute minimum. The tunnel oxide...... to be an important energy loss center for the electrons tunneling through the oxide lowering the emission e±ciency of a factor of 10 for a 1 nm Ti layer thickness. Electron emission is observed under ambient pressure conditions and in up to 2 bars of Ar. 2 bar Ar decrease the emission current by an order...

  7. Simulation study on the maximum continuous working condition of a power plant boiler

    Science.gov (United States)

    Wang, Ning; Han, Jiting; Sun, Haitian; Cheng, Jiwei; Jing, Ying'ai; Li, Wenbo

    2018-05-01

    First of all, the boiler is briefly introduced to determine the mathematical model and the boundary conditions, then the boiler under the BMCR condition numerical simulation study, and then the BMCR operating temperature field analysis. According to the boiler actual test results and the hot BMCR condition boiler output test results, the simulation results are verified. The main conclusions are as follows: the position and size of the inscribed circle in the furnace and the furnace temperature distribution and test results under different elevation are compared and verified; Accuracy of numerical simulation results.

  8. Hot deformation effect on the kinetics of austenite transformation under continuous cooling conditions

    International Nuclear Information System (INIS)

    Bernshtejn, M.L.; Zajmovskij, V.A.; Kisteh, N.V.; Samedov, O.V.; Faldin, S.A.

    1979-01-01

    The effect of hot deformation on the kinetics of austenite transformations in the commercial 4040Kh 40KhN, and 40KhNMA steels on continuous cooling was studied. The transformations were studied using a dilatometer of a special design which permits a specimen to be fixed quickly in holders after hot deformation. It is stated that in hot-deformed austenite the pearlite transformation proceeds at higher temperatures and in a narrower temperature range. Austenite deformation provides an opportunity to obtain a more fine ferrite-pearlite structure and ensures a uniform distribution of a structurally free ferrite in the steel bulk. The effect of hot deformation on the structure of ferrite decomposition products in the 40KhN and 40KhNMA steels is more complicated, which is connected with a substantial change in the kinetics of pearlite and intermediate transformations

  9. Improving working conditions and increasing profits in forestry.

    OpenAIRE

    Johansson K; Strehlke B

    1996-01-01

    Briefly looks at the links between work organization, productivity and working conditions. Discusses the advantages which can be gained by using appropriate tools and techniques and improving working conditions and safety. Based on 24 case studies which cover a broad range of forestry activities.

  10. Working conditions, work life and quality of life of the temporary ...

    African Journals Online (AJOL)

    Five major categories resulted: experiences of the organisational structure; work life; interpersonal relationships; occupational development and quality of life while working at TLS. Conclusions were that staff experienced working conditions mainly as unpleasant, but that they adapted because of the team spirit.

  11. Do scientists trace hot topics?

    Science.gov (United States)

    Wei, Tian; Li, Menghui; Wu, Chensheng; Yan, Xiao-Yong; Fan, Ying; Di, Zengru; Wu, Jinshan

    2013-01-01

    Do scientists follow hot topics in their scientific investigations? In this paper, by performing analysis to papers published in the American Physical Society (APS) Physical Review journals, it is found that papers are more likely to be attracted by hot fields, where the hotness of a field is measured by the number of papers belonging to the field. This indicates that scientists generally do follow hot topics. However, there are qualitative differences among scientists from various countries, among research works regarding different number of authors, different number of affiliations and different number of references. These observations could be valuable for policy makers when deciding research funding and also for individual researchers when searching for scientific projects.

  12. Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

    Directory of Open Access Journals (Sweden)

    Brianna Larsen

    Full Text Available This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36 were matched and allocated to either the CON (19°C or HOT (33°C condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc, and skin temperature (Tsk were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of

  13. Multiple Days of Heat Exposure on Firefighters’ Work Performance and Physiology

    Science.gov (United States)

    Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

    2015-01-01

    This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants’ doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants’ work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological

  14. Demand-specific work ability, poor health and working conditions in middle-aged full-time employees

    DEFF Research Database (Denmark)

    Nabe-Nielsen, Kirsten; Thielen, Karsten; Nygaard, Else

    2014-01-01

    -sectional questionnaire data from 3381 full-time employees responding to questions about vocational education, job demands and social support (working conditions), musculoskeletal pain (MSP) and major depression (MD) (poor health) and seven questions about difficulty managing different job demands (reduced demand......We investigated the prevalence of reduced demand-specific work ability, its association with age, gender, education, poor health, and working conditions, and the interaction between poor health and working conditions regarding reduced demand-specific work ability. We used cross...... was associated with six measures of reduced demand-specific work ability. We found no interaction between working conditions and poor health regarding reduced demand-specific work ability....

  15. Validating the Heat Stress Indices for Using In Heavy Work Activities in Hot and Dry Climates.

    Science.gov (United States)

    Hajizadeh, Roohalah; Golbabaei, Farideh; Farhang Dehghan, Somayeh; Beheshti, Mohammad Hossein; Jafari, Sayed Mohammad; Taheri, Fereshteh

    2016-01-01

    Necessity of evaluating heat stress in the workplace, require validation of indices and selection optimal index. The present study aimed to assess the precision and validity of some heat stress indices and select the optimum index for using in heavy work activities in hot and dry climates. It carried out on 184 workers from 40 brick kilns workshops in the city of Qom, central Iran (as representative hot and dry climates). After reviewing the working process and evaluation the activity of workers and the type of work, environmental and physiological parameters according to standards recommended by International Organization for Standardization (ISO) including ISO 7243 and ISO 9886 were measured and indices were calculated. Workers engaged in indoor kiln experienced the highest values of natural wet temperature, dry temperature, globe temperature and relative humidity among studied sections (Pstress index (HSI) indices had the highest correlation with other physiological parameters among the other heat stress indices. Relationship between WBGT index and carotid artery temperature (r=0.49), skin temperature (r=0.319), and oral temperature (r=0.203) was statistically significant (P=0.006). Since WBGT index, as the most applicable index for evaluating heat stress in workplaces is approved by ISO, and due to the positive features of WBGT such as ease of measurement and calculation, and with respect to some limitation in application of HSI; WBGT can be introduced as the most valid empirical index of heat stress in the brick workshops.

  16. Potential Alternative Lower Global Warming Refrigerants for Air Conditioning in Hot Climates

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL; Shen, Bo [ORNL

    2017-01-01

    The earth continues to see record increase in temperatures and extreme weather conditions that is largely driven by anthropogenic emissions of warming gases such as carbon dioxide and other more potent greenhouse gases such as refrigerants. The cooperation of 188 countries in the Conference of the Parties in Paris 2015 (COP21) resulted in an agreement aimed to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2 C. A global phasedown of hydrofluorocarbons (HFCs) can prevent 0.5 C of warming by 2100. However, most of the countries in hot climates are considered as developing countries and as such are still using R-22 (a Hydrochlorofluorocarbon (HCFC)) as the baseline refrigerant and are currently undergoing a phase-out of R-22 which is controlled by current Montreal Protocol to R-410A and other HFC based refrigerants. These HFCs have significantly high Global Warming Potential (GWP) and might not perform as well as R-22 at high ambient temperature conditions. In this paper we present recent results on evaluating the performance of alternative lower GWP refrigerants for R-22 and R-410A for small residential mini-split air conditioners and large commercial packaged units. Results showed that several of the alternatives would provide adequate replacement for R-22 with minor system modification. For the R-410A system, results showed that some of the alternatives were almost drop-in ready with benefit in efficiency and/or capacity. One of the most promising alternatives for R-22 mini-split unit is propane (R-290) as it offers higher efficiency; however it requires compressor and some other minor system modification to maintain capacity and minimize flammability risk. Between the R-410A alternatives, R-32 appears to have a competitive advantage; however at the cost of higher compressor discharge temperature. With respect to the hydrofluoroolefin (HFO) blends, there existed a tradeoff in performance and system design

  17. Gender and the Intensification of Work: Evidence from the European Working Conditions Surveys

    OpenAIRE

    Brendan Burchell; Colette Fagan

    2004-01-01

    This paper uses the European Working Conditions Surveys to examine the intensity of work for male and female employees. The first section gives an overview of the usefulness of the survey for examining European Union (EU) working conditions and shows how women's intensity of work has been increasing faster than that of men, so that by the year 2000 there was little gender difference in the speed of work. Section two demonstrates that the intensity of work has a negative effect on health and w...

  18. EU hotel and restaurant sector : work and employment conditions

    NARCIS (Netherlands)

    Klein Hesselink, J.; Houtman, I.; Berg, R. van den; Bossche, S. van den; Heuvel, F. van den

    2004-01-01

    In 2000, the European Foundation for the Improvement of Living and Working Conditions (the Foundation) carried out the third European Survey on Working Conditions. In that survey, information was collected on the working conditions, health and wellbeing of employed and self-employed persons in the

  19. 3-D thermoelastic analysis of the straight section of a PWR hot leg containing a hot spot using BEM

    International Nuclear Information System (INIS)

    Bains, R.S.; Sugimoto, J.

    1995-01-01

    A 3-D steady state thermoelastic analysis using the boundary element method has been successfully employed to investigate the structural response of the straight section of a pressurised water reactor hot leg containing a localised hot spot. With the present severe accident thermal boundary conditions, the analysis produces a nonuniform expansion across the hot leg thickness. This expansion was most predominant on the inner surface, especially at the hot spot location where surface swelling was obtained. Furthermore, the hot spot generates large tangential and axial tensile stresses on the outer surface. These could be detrimental to the integrity of the hot leg by acting as potential sites of crack initiation and subsequent propagation. (orig.)

  20. Hot-pressing steatite bodies

    International Nuclear Information System (INIS)

    Aparicio Arroyo, E.

    1967-01-01

    Requirements for some special nuclear engineering ceramic shapes are: big size, impervious, dimensional accuracy and good mechanical and dielectric properties. Limitations of te conventional methods and advantages of te hot pressing techniques for the manufacturing of these shapes are discussed. Hot pressing characteristics of a certain steatite powder are studied. Occurrence of an optimum densification temperature just above the tale decomposition range is found. Experimental data show that the height/diameter ratio of the specimen has no effect on the sintering conditions. Increasing darkness from the graphite mould is detected above the optimum temperature. The hot-pressed steatite is compared with a fired dry-pressed sample of the same composition. (Author) 13 refs

  1. Energetic optimization of the performances of a hot air engine for micro-CHP systems working with a Joule or an Ericsson cycle

    International Nuclear Information System (INIS)

    Creyx, M.; Delacourt, E.; Morin, C.; Desmet, B.; Peultier, P.

    2013-01-01

    The micro combined heat and electrical power systems (micro-CHP) with hot air engines are well adapted for solid biomass upgrading, in particular, the Ericsson engines working with an open cycle and an external combustion. This paper presents a model of an Ericsson engine with a compression and an expansion cylinder which allows a thermodynamic optimization of the engine performances in a global approach. A sensitive analysis on the influent parameters is carried out in order to determine the optimal working conditions of the engine: temperature and pressure range, expansion cycle shape with a late intake valve closing or an early exhaust valve closing, heat transfers through the wall of the cylinders. This study, focused on thermodynamic aspects, is a first step in the design of an Ericsson engine. -- Highlights: ► A model of Ericsson engine working with a Joule or Ericsson cycle is presented. ► Influent factors on the engine performances are investigated. ► The heat exchanges in the cylinder wall must be avoided to improve the performances. ► Closing the intake valve late and the exhaust valve early enhances the performances. ► Efficiency, indicated mean pressure, specific work are thermodynamically optimized.

  2. The Impact of Heat Exposure and Sleep Restriction on Firefighters' Work Performance and Physiology during Simulated Wildfire Suppression.

    Science.gov (United States)

    Vincent, Grace E; Aisbett, Brad; Larsen, Brianna; Ridgers, Nicola D; Snow, Rod; Ferguson, Sally A

    2017-02-12

    This study was designed to examine the effects of ambient heat on firefighters' physical task performance, and physiological and perceptual responses when sleep restricted during simulated wildfire conditions. Thirty firefighters were randomly allocated to the sleep restricted ( n = 17, SR; 19 °C, 4-h sleep opportunity) or hot and sleep restricted ( n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Firefighters performed two days of simulated, intermittent, self-paced work circuits comprising six firefighting tasks. Heart rate, and core temperature were measured continuously. After each task, firefighters reported their rating of perceived exertion and thermal sensation. Effort sensation was also reported after each work circuit. Fluids were consumed ad libitum. Urine volume and urine specific gravity were analysed. Sleep was monitored using polysomnography. There were no differences between the SR and HOT + SR groups in firefighters' physiological responses, hydration status, ratings of perceived exertion, motivation, and four of the six firefighting tasks (charged hose advance, rake, hose rolling, static hose hold). Black out hose and lateral repositioning were adversely affected in the HOT + SR group. Working in hot conditions did not appear to consistently impair firefighters work performance, physiology, and perceptual responses. Future research should determine whether such findings remain true when individual tasks are performed over longer durations.

  3. Health, work and working conditions: a review of the European economic literature.

    Science.gov (United States)

    Barnay, Thomas

    2016-07-01

    Economists have traditionally been very cautious when studying the interaction between employment and health because of the two-way causal relationship between these two variables: health status influences the probability of being employed and, at the same time, working affects the health status. Because these two variables are determined simultaneously, researchers control endogeneity skews (e.g., reverse causality, omitted variables) when conducting empirical analysis. With these caveats in mind, the literature finds that a favourable work environment and high job security lead to better health conditions. Being employed with appropriate working conditions plays a protective role on physical health and psychiatric disorders. By contrast, non-employment and retirement are generally worse for mental health than employment, and overemployment has a negative effect on health. These findings stress the importance of employment and of adequate working conditions for the health of workers. In this context, it is a concern that a significant proportion of European workers (29 %) would like to work fewer hours because unwanted long hours are likely to signal a poor level of job satisfaction and inadequate working conditions, with detrimental effects on health. Thus, in Europe, labour-market policy has increasingly paid attention to job sustainability and job satisfaction. The literature clearly invites employers to take better account of the worker preferences when setting the number of hours worked. Overall, a specific "flexicurity" (combination of high employment protection, job satisfaction and active labour-market policies) is likely to have a positive effect on health.

  4. Hot deformation behaviors and processing maps of B{sub 4}C/Al6061 neutron absorber composites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yu-Li [School of Materials Science and Engineering, Taiyuan University Of Technology, Taiyuan 030024 (China); Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); Wang, Wen-Xian, E-mail: Wangwenxian@tyut.edu.cn [School of Materials Science and Engineering, Taiyuan University Of Technology, Taiyuan 030024 (China); Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); Zhou, Jun [School of Materials Science and Engineering, Taiyuan University Of Technology, Taiyuan 030024 (China); Department of Mechanical Engineering, Pennsylvania State University Erie, The Behrend College, Erie, PA 16563 (United States); Chen, Hong-Sheng [School of Materials Science and Engineering, Taiyuan University Of Technology, Taiyuan 030024 (China); Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China)

    2017-02-15

    In this study, the hot deformation behaviors of 30 wt.% B{sub 4}C/Al6061 neutron absorber composites (NACs) have been investigated by conducting isothermal compression tests at temperatures ranging from 653 K to 803 K and strain rates from 0.01 to 10 s{sup −1}. It was found that, during hot compression, the B{sub 4}C/Al6061 NACs exhibited a steady flow characteristic which can be expressed by the Zener-Hollomon parameter as a hyperbolic-sine function of flow stress. High average activation energy (185.62 kJ/mol) of B{sub 4}C/Al6061 NACs is noted in current study owing to the high content of B{sub 4}C particle. The optimum hot working conditions for B{sub 4}C/Al6061 NACs are found to be 760–803 K/0.01–0.05 s{sup −1} based on processing map and microstructure evolution. Typical material instabilities are thought to be attributed to void formation, adiabatic shear bands (ASB), particle debonding, and matrix cracking. Finally, the effect of the plastic deformation zones (PDZs) on the microstructure evolution in this 30 wt.% B{sub 4}C/Al6061 composite is found to be very important. - Highlights: •The hot deformation behavior of the 30 wt.% B{sub 4}C/Al6061 NACs was first analyzed. •The 3D efficiency map and the instability map are developed. •The optimum hot working conditions were identified and validated by SEM and TEM. •The hot deformation schematic diagram of 30 wt.% B{sub 4}C/Al6061 NACs is developed.

  5. The effect of the menstrual cycle and water consumption on physiological responses during prolonged exercise at moderate intensity in hot conditions.

    Science.gov (United States)

    Hashimoto, Hideki; Ishijima, Toshimichi; Suzuki, Katsuhiko; Higuchi, Mitsuru

    2016-09-01

    Reproductive hormones are likely to be involved in thermoregulation through body fluid dynamics. In the present study, we aimed to investigate the effect of the menstrual cycle and water consumption on physiological responses to prolonged exercise at moderate intensity in hot conditions. Eight healthy young women with regular menstrual cycles performed cycling exercise for 90 minutes at 50% V̇O2peak intensity during the low progesterone (LP) level phase and high progesterone (HP) level phase, with or without water consumption, under hot conditions (30°C, 50% relative humidity). For the water consumption trials, subjects ingested water equivalent to the loss in body weight that occurred in the earlier non-consumption trial. For all four trials, rectal temperature, cardiorespiratory responses, and ratings of perceived exertion (RPE) were measured. Throughout the 90-minute exercise period, rectal temperatures during HP were higher than during LP by an average of 0.4 °C in the non-consumption trial (Pwater consumption trial (Pwater consumption affected the changes in rectal temperature and heat rate (HR) during HP, but it did not exert these effects during LP. Furthermore, we found a negative correlation between estradiol levels and rectal temperature during LP. During prolonged exercise at moderate intensity under hot conditions, water consumption is likely to be useful for suppressing the associated increase in body temperature and HR, particularly during HP, whereas estradiol appears to be useful for suppressing the increase in rectal temperature during LP.

  6. Psychosocial working conditions and work-related stressors among UK veterinary surgeons.

    Science.gov (United States)

    Bartram, David J; Yadegarfar, Ghasem; Baldwin, David S

    2009-08-01

    Anecdotally, veterinary surgeons report high levels of work-related stress. To investigate psychosocial working conditions, self-reported causes of work-related stress and satisfaction among a representative sample of vets practising in the UK. A cross-sectional study using a questionnaire mailed to a stratified random sample of 3200 vets. The Health & Safety Executive Management Standards Indicator Tool and a series of bespoke questions were embedded in a 120 item questionnaire, which also assessed anxiety and depressive symptoms, alcohol consumption, suicidal ideation, positive mental well-being and work-home interaction. A total of 1796 useable questionnaires were returned (response rate 56%). Number of hours worked and making professional mistakes were the main reported contributors to stress. Good clinical outcomes and relationships with colleagues were the greatest sources of satisfaction. Anxiety and depressive symptoms are associated with less favourable working conditions. Compared to the general population, the sample reported higher risk of work-related stress for demands and managerial support but lower risk for relationships and change. The results could be used to inform the development of targeted interventions.

  7. Nursing work hours: individual needs versus working conditions.

    Science.gov (United States)

    Silva, Amanda Aparecida; Rotenberg, Lúcia; Fischer, Frida Marina

    2011-12-01

    To assess factors associated with professional and total hours of work (work + home) among nursing staff. Cross-sectional study conducted in a university hospital in the city of São Paulo, southeastern Brazil, between 2004 and 2005. A total of 696 workers (nurses, nurse technicians and aids), mostly women (87.8%) working day and/or night shifts, participated in the study. A self-administered questionnaire was used to collected information on demographic characteristics, and working and life conditions. Translated and adapted into Portuguese versions of the Job Stress Scale, Effort-reward imbalance, Short-Form-Health-related quality of life and the Work Ability Index were also administered. Logistic regression models were used for data analysis. Sole breadwinner, working night shifts and effort-reward imbalance were the variables associated with both professional (OR = 3.38, OR = 10.43, OR = 2.07, respectively) and total hours of work (OR = 1.57, OR = 3.37, OR = 2.75, respectively). There was no significant association between the variables related to hours of work and low Work Ability Index. Inadequate rest at home was statistically associated with professional (OR = 2.47) and total hours of work (OR = 1.48). Inadequate leisure time was significantly associated with professional hours of work (OR = 1.58) and barely associated with total hours of work (OR = 1.43). The sole breadwinner, working night shifts and effort-reward imbalance are variables that need to be further investigated in studies on work hours among nursing staff. These studies should explore workers' income and the relationship between effort and reward, taking into consideration gender issues.

  8. Workplace rehabilitation and supportive conditions at work: a prospective study.

    Science.gov (United States)

    Ahlstrom, Linda; Hagberg, Mats; Dellve, Lotta

    2013-06-01

    To investigate the impact of rehabilitation measures on work ability and return to work (RTW), specifically the association between workplace rehabilitation/supportive conditions at work and work ability and RTW over time, among women on long-term sick leave. Questionnaire data were collected (baseline, 6 and 12 months) from a cohort of women (n = 324). Linear mixed models were used for longitudinal analysis of the repeated measurements of work ability index (WAI), work ability score and working degree. These analyses were performed with different models; the explanatory variables for each model were workplace rehabilitation, supportive conditions at work and time. The individuals provided with workplace rehabilitation and supportive conditions (e.g. influence at work, possibilities for development, degree of freedom at work, meaning of work, quality of leadership, social support, sense of community and work satisfaction) had significantly increased WAI and work ability score over time. These individuals scored higher work ability compared to those individuals having workplace rehabilitation without supportive conditions, or neither. Additionally, among the individuals provided with workplace rehabilitation and supportive conditions, working degree increased significantly more over time compared to those individuals with no workplace rehabilitation and no supportive conditions. The results highlight the importance of integrating workplace rehabilitation with supportive conditions at work in order to increase work ability and improve the RTW process for women on long-term sick leave.

  9. Exposure to hot and cold environmental conditions does not affect the decision making ability of soccer referees following an intermittent sprint protocol.

    Directory of Open Access Journals (Sweden)

    Lee eTaylor

    2014-05-01

    Full Text Available Soccer referees enforce the laws of the game and the decisions they make can directly affect match results. Fixtures within European competitions take place in climatic conditions that are often challenging (e.g. Moscow ~ -5oC, Madrid ~30oC. Effects of these temperatures on player performance are well documented; however, little is known how this environmental stress may impair cognitive performance of soccer referees and if so, whether exercise exasperates this. The present study aims to investigate the effect of cold (COLD; 5oC, 40% relative humidity (RH, hot (HOT; 30oC, 40% RH and temperate (CONT; 18oC, 40% RH conditions on decision making during soccer specific exercise. On separate occasions within each condition, thirteen physically active males; either semi-professional referees or semi-professional soccer players completed three 90 min intermittent treadmill protocols that simulated match play, interspersed with 4 computer delivered cognitive tests to measure vigilance and dual task capacity. Core and skin temperature, heart rate, rating of perceived exertion and thermal sensation were recorded throughout the protocol. There was no significant difference between conditions for decision making (p > 0.05 despite significant differences in measured physiological variables (skin temperature = HOT 34.5 ± 5.1°C; CONT 31.2 ± 0.1°C and COLD 26.7 ± 0.5°C; p < 0.05. It is hypothesised that the lack of difference observed in decision making ability between conditions was due to the exercise protocol used, as it may not have elicited an appropriate and valid soccer specific internal load to alter cognitive functioning.

  10. Exposure to hot and cold environmental conditions does not affect the decision making ability of soccer referees following an intermittent sprint protocol.

    Science.gov (United States)

    Taylor, Lee; Fitch, Natalie; Castle, Paul; Watkins, Samuel; Aldous, Jeffrey; Sculthorpe, Nicholas; Midgely, Adrian; Brewer, John; Mauger, Alexis

    2014-01-01

    Soccer referees enforce the laws of the game and the decisions they make can directly affect match results. Fixtures within European competitions take place in climatic conditions that are often challenging (e.g., Moscow ~ -5°C, Madrid ~30°C). Effects of these temperatures on player performance are well-documented; however, little is known how this environmental stress may impair cognitive performance of soccer referees and if so, whether exercise exasperates this. The present study aims to investigate the effect of cold [COLD; -5°C, 40% relative humidity (RH)], hot (HOT; 30°C, 40% RH) and temperate (CONT; 18°C, 40% RH) conditions on decision making during soccer specific exercise. On separate occasions within each condition, 13 physically active males; either semi-professional referees or semi-professional soccer players completed three 90 min intermittent treadmill protocols that simulated match play, interspersed with 4 computer delivered cognitive tests to measure vigilance and dual task capacity. Core and skin temperature, heart rate, rating of perceived exertion (RPE) and thermal sensation (TS) were recorded throughout the protocol. There was no significant difference between conditions for decision making in either the dual task (interaction effects: FALSE p = 0.46; MISSED p = 0.72; TRACKING p = 0.22) or vigilance assessments (interaction effects: FALSE p = 0.31; HIT p = 0.15; MISSED p = 0.17) despite significant differences in measured physiological variables (skin temperature: HOT vs. CONT 95% CI = 2.6 to 3.9, p decision making ability between conditions was due to the exercise protocol used, as it may not have elicited an appropriate and valid soccer specific internal load to alter cognitive functioning.

  11. Chronic health conditions and work ability in the ageing workforce : the impact of work conditions, psychosocial factors and perceived health

    NARCIS (Netherlands)

    Koolhaas, Wendy; van der Klink, Jac J. L.; de Boer, Michiel R.; Groothoff, Johan W.; Brouwer, Sandra

    The aim of this study was to determine the influence of work conditions, psychosocial factors and perceived health on the association between the presence of a chronic health condition and (single-item) work ability among workers aged 45 years and older. In addition, we aimed to examine variables

  12. Chronic health conditions and work ability in the ageing workforce: the impact of work conditions, psychosocial factors and perceived health

    NARCIS (Netherlands)

    Koolhaas, W.; van der Klink, J.J.L.; de Boer, M.R.; Groothoff, J.W.; Brouwer, S.

    2014-01-01

    Purpose: The aim of this study was to determine the influence of work conditions, psychosocial factors and perceived health on the association between the presence of a chronic health condition and (single-item) work ability among workers aged 45 years and older. In addition, we aimed to examine

  13. Modelling and simulations in hot deformation of steels

    International Nuclear Information System (INIS)

    Cabrera, J.M.

    2002-01-01

    Traditionally, hot forming has been employed to provide shape to metals. Nowadays, however, hot working not only produces the desired geometry, but also the mechanical characteristics required. An understanding of the thermomechanical behaviour of metals, and particularly steels, is essential in the simulation and control of the hot forming operations. Moreover, a right prediction of the final properties needs from accurate descriptions of the microstructural features occurring during the shaping step. For this purpose, the determination of constitutive equations describing the stress σ - strain ε relationships at a given strain rate ε, temperature T and initial microstructure, is a useful task. In this sense, computer simulations of hot working processes proportionate a benchmark to engineers and researchers and allow decreasing the cost of developing products and processes. With regard to the prediction of the final microstructure, the simulation of the hot plastic deformation usually gives unsatisfactory results. This is due to the inadequate constitutive equations employed by the conventional and commercial software available to describe the hot flow behaviour. There are scarce models which couple the typical hot working variables (temperature, strain and strain rate) with microstructural characteristics such as grain size. In this review work is presented how the latter limitation can be overcome by using physical-based constitutive equations, some of which have been partially developed by the present authors, where account of the interaction between microstructure and processing variables is taken. Moreover, a practical derivation of the latter expressions on an AISI-304 steel is presented. To conclude, some examples of industrial applications of the latter approach are also presented. Copyright (2002) AD-TECH - International Foundation for the Advancement of Technology Ltd

  14. [Characteristics of working conditions at metallurgy-related plants].

    Science.gov (United States)

    Egorova, A M

    2008-01-01

    Working conditions at more versus less advanced technology steel plants of the Volgograd Region are analyzed. The working conditions at the less advanced technology plants are referred to as a very high occupational risk. It is necessary to work out measures to lower the poor impact of microclimate, dust, noise, to improve illumination, and to regulate labor at steel plants.

  15. Utilization of Indonesia's Hot Spring Sources for Electricity using Kalina Cycle and Organic Rankine Cycle

    Science.gov (United States)

    Prabumukti, Grano; Purwanto; Widodo, Wahyu

    2018-02-01

    Indonesia posses 40% of the world's geothermal energy sources. The existence of hydrothermal sources is usually characterized by their surface manifestations such as hot springs, geysers and fumarole. Hot spring has a potential to be used as a heat source to generate electricity especially in a rural and isolated area. Hot springs can be converted into electricity by binary thermodynamic cycles such as Kalina cycle and ORC. The aim of this study is to obtain the best performances of cycle configuration and the potential power capacity. Simulation is conducted using UNISIM software with working fluid and its operating condition as the decision variables. The simulation result shows that R1234yf and propene with simple ORC as desired working fluid and cycle configuration. It reaches a maximum thermal efficiency up to 9.6% with a specific turbine inlet pressure. Higher temperature heat source will result a higher thermal efficiency‥ Cycle thermal efficiency varies from 4.7% to 9.6% depends on source of hot spring temperature. Power capacity that can be generated using Indonesia's hot spring is ranged from 2 kWe to 61.2 kWe. The highest capacity located in Kawah Sirung and the least located in Kaendi.

  16. Influences of silicon on the work hardening behavior and hot deformation behavior of Fe–25 wt%Mn–(Si, Al) TWIP steel

    International Nuclear Information System (INIS)

    Li, Dejun; Feng, Yaorong; Song, Shengyin; Liu, Qiang; Bai, Qiang; Ren, Fengzhang; Shangguan, Fengshou

    2015-01-01

    Highlights: • Influence of Si on work hardening behavior of Fe–25 wt%Mn TWIP steel was investigated. • Influence of Si on hot deformation behavior of Fe–25 wt%Mn TWIP steel was studied. • Si blocks dislocation glide and favors mechanical twinning in Fe–25 wt%Mn TWIP steel. • The addition of Si increases the hot deformation activation energy of Fe–25 wt%Mn TWIP steel. • The addition of Si retards the nucleation and growth of DRX grains of Fe–25 wt%Mn TWIP steel. - Abstract: The influence of silicon on mechanical properties and hot deformation behavior of austenitic Fe–25 wt%Mn TWIP steel was investigated by means of the comparison research between 25Mn3Al and 25Mn3Si3Al steel. The results show that the 25Mn3Si3Al steel has higher yield strength and higher hardness than that of 25Mn3Al steel because of the solution strengthening caused by Si atoms and possesses higher uniform deformation ability and tensile strength than that of 25Mn3Al steel due to the higher work hardening ability of 25Mn3Si3Al steel. 25Mn3Si3Al steel presents a clear four-stage curve of work hardening rate in course of cold compression. Quite the opposite, the 25Mn3Al steel presents a monotonic decline curve of work hardening rate. The difference of the work hardening behavior between 25Mn3Al and 25Mn3Si3Al steel can be attributed to the decline of stacking fault energy (SFE) caused by the addition of 3 wt% Si. The dislocation glide plays an important role in the plastic deformation of 25Mn3Al steel even though the mechanical twinning is still one of the main deformation mechanisms. The 3 wt% Si added into the 25Mn3Al steel blocks the dislocation glide and promotes the mechanical twinning, and then the dislocation glide characteristics cannot be observed in cold deformed microstructure of 25Mn3Si3Al steel. The hot compression tests reveal that the hot deformation resistance of the 25Mn3Si3Al steel is significantly higher than that of the 25Mn3Al steel due to the solid

  17. Work Rate during Self-paced Exercise is not Mediated by the Rate of Heat Storage.

    Science.gov (United States)

    Friesen, Brian J; Périard, Julien D; Poirier, Martin P; Lauzon, Martin; Blondin, Denis P; Haman, Francois; Kenny, Glen P

    2018-01-01

    To date, there have been mixed findings on whether greater anticipatory reductions in self-paced exercise intensity in the heat are mediated by early differences in rate of body heat storage. The disparity may be due to an inability to accurately measure minute-to-minute changes in whole-body heat loss. Thus, we evaluated whether early differences in rate of heat storage can mediate exercise intensity during self-paced cycling at a fixed rate of perceived exertion (RPE of 16; hard-to-very-hard work effort) in COOL (15°C), NORMAL (25°C), and HOT (35°C) ambient conditions. On separate days, nine endurance-trained cyclists exercised in COOL, NORMAL, and HOT conditions at a fixed RPE until work rate (measured after first 5 min of exercise) decreased to 70% of starting values. Whole-body heat loss and metabolic heat production were measured by direct and indirect calorimetry, respectively. Total exercise time was shorter in HOT (57 ± 20 min) relative to both NORMAL (72 ± 23 min, P = 0.004) and COOL (70 ± 26 min, P = 0.045). Starting work rate was lower in HOT (153 ± 31 W) compared with NORMAL (166 ± 27 W, P = 0.024) and COOL (170 ± 33 W, P = 0.037). Rate of heat storage was similar between conditions during the first 4 min of exercise (all P > 0.05). Thereafter, rate of heat storage was lower in HOT relative to NORMAL and COOL until 30 min of exercise (last common time-point between conditions; all P exercise. No differences were measured at end exercise. We show that rate of heat storage does not mediate exercise intensity during self-paced exercise at a fixed RPE in cool to hot ambient conditions.

  18. Flexible employment policies and working conditions: the Netherlands

    NARCIS (Netherlands)

    Klein Hesselink, D.J.; Miedema, E.; Goudswaard, A.; Kraan, K.O.

    2000-01-01

    The European Foundation for the Improvement of Living and Working Conditions has commissioned a research project to analyse the impact of flexible employment policies and human resources management on working conditions at the corporate level. Research institutes of seven countries participate in

  19. Ionospheric hot spot at high latitudes

    International Nuclear Information System (INIS)

    Schunk, R.W.; Sojka, J.J.

    1982-01-01

    A hot spot (or spots) can occur in the high-latitude ionosphere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time-magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m -1 . For electric fields of the order of 100 mV m -1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 0 K at 160 km, and decreases with altitude in the F-region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions

  20. Hot Films on Ceramic Substrates for Measuring Skin Friction

    Science.gov (United States)

    Noffz, Greg; Leiser, Daniel; Bartlett, Jim; Lavine, Adrienne

    2003-01-01

    Hot-film sensors, consisting of a metallic film on an electrically nonconductive substrate, have been used to measure skin friction as far back as 1931. A hot film is maintained at an elevated temperature relative to the local flow by passing an electrical current through it. The power required to maintain the specified temperature depends on the rate at which heat is transferred to the flow. The heat transfer rate correlates to the velocity gradient at the surface, and hence, with skin friction. The hot-film skin friction measurement method is most thoroughly developed for steady-state conditions, but additional issues arise under transient conditions. Fabricating hot-film substrates using low-thermal-conductivity ceramics can offer advantages over traditional quartz or polyester-film substrates. First, a low conductivity substrate increases the fraction of heat convected away by the fluid, thus increasing sensitivity to changes in flow conditions. Furthermore, the two-part, composite nature of the substrate allows the installation of thermocouple junctions just below the hot film, which can provide an estimate of the conduction heat loss.

  1. Identification for the optimal working parameters of Ti-6Al-4V-0.1Ru alloy in a wide deformation condition range by processing maps based on DMM

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yu-feng; Long, Shuai; Zhou, Yu-ting; Zhao, Jia; Wang, Tian-yu; Zhou, Jie, E-mail: kkyttyls@vip.qq.com [School of Material Science and Engineering, Chongqing University (China)

    2016-11-15

    The hot deformation behaviours of Ti-6Al-4V-0.1Ru alloy were investigated by isothermal hot compression tests in the temperature range of 1023-1423 K and strain rate range of 0.01-10 s{sup -1}. The β transus was determined to be 1198 K by continuous heating method. The values of deformation activation energy Q at the strain of 0.3 were calculated to be 630.01 kJ/mol in dual-phase field and 331.75 kJ/mol in β-phase field. Moreover, the processing maps at the strain of 0.2, 0.4, 0.6 and 0.8 were developed based on dynamic materials model (DMM). To deeply understand the microstructure evolution mechanism during hot deformation processes and to verify the processing maps, the microstructures at different deformation conditions were observed. The stable microstructures (i.e. globularization, dynamic recovery (DRV) and β dynamic recrystallization (β-DRX)) and instable microstructures (i.e. lamellae kinking and flow localization) were obtained. To make it useful in the design of industrial hot working schedules for this material, a microstructural mechanism map was constructed on the basis of processing maps and microstructure observation. Deformation conditions in the vicinity of 1150 K & 0.01 s{sup -1} where globularization occurs and in the vicinity of 1323 K & 0.01 s{sup -1} where β-DRX occurs are recommended. (author)

  2. Recovery of energy from geothermal brine and other hot water sources

    Science.gov (United States)

    Wahl, III, Edward F.; Boucher, Frederic B.

    1981-01-01

    Process and system for recovery of energy from geothermal brines and other hot water sources, by direct contact heat exchange between the brine or hot water, and an immiscible working fluid, e.g. a hydrocarbon such as isobutane, in a heat exchange column, the brine or hot water therein flowing countercurrent to the flow of the working fluid. The column can be operated at subcritical, critical or above the critical pressure of the working fluid. Preferably, the column is provided with a plurality of sieve plates, and the heat exchange process and column, e.g. with respect to the design of such plates, number of plates employed, spacing between plates, area thereof, column diameter, and the like, are designed to achieve maximum throughput of brine or hot water and reduction in temperature differential at the respective stages or plates between the brine or hot water and the working fluid, and so minimize lost work and maximize efficiency, and minimize scale deposition from hot water containing fluid including salts, such as brine. Maximum throughput approximates minimum cost of electricity which can be produced by conversion of the recovered thermal energy to electrical energy.

  3. Working conditions in seafaring international

    DEFF Research Database (Denmark)

    Jensen, Olaf Chresten; Canals, M. Luisa

    2008-01-01

    . The average was 60-80 working hours a week. 60% had 70 hours or more per week and one third more than 80 hours. 80 % worked all the 7 days in the week. Officers were 15-30% among the Philippines and Indonesian seafarers and 80% among the seafarers from United Kingdom and Denmark. 80% of the seafarers from...... frequent involved. Seafarers from the Philippines and Indonesia had low incidence rates of injury. The self-perceived health was generally good among the seafarers, with some national exceptions Conclusions - Remarkable non-equity for work conditions between the nationalities - Working hours per week......Background The world merchant fleet comprise about 1.4 million seafarers. Multi ethnic crews make about 2/3 of the world merchant fleet. The purpose was to descripe important aspects of the working environment for seafarers. Method The seafarers have biannual health examinations and they used 5...

  4. Cast iron as structural material for hot-working reactor vessels (PCIV)

    International Nuclear Information System (INIS)

    Ostendorf, H.; Schmidt, G.; Pittack, W.

    1977-01-01

    Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary. - Mechanical properties under compressive stresses. - Material properties at elevated temperatures. - Influence of irradiation on mechanical and physical properties. - Production standards and quality control. The state of the research and the available data of the material testing program are reported. (Auth.)

  5. Cast iron as structural material for hot-working reactor vessels (PCIV)

    International Nuclear Information System (INIS)

    Ostendorf, H.; Schmidt, G.; Pittack, W.

    1977-01-01

    Cast iron with lamellar graphite is best suited for prestressed structures, because its compressive strength is nearly 4 times its tensile strength. In comparison to room temperature, cast iron with lamellar graphite shows essentially no loss of strength up to temperatures of 400 0 C. Under the particular aspect to use cast iron for hot-working prestressed reactor pressure vessels (PCIV) (Prestressed cast iron vessel=PCIV) a materials testing program is carried out, which meets the strict certification requirements for materials in the construction of reactor pressure vessels and which completes the presently available knowledge of cast iron. Especially in the following fields an extension and supplement of the present level of knowledge is necessary: mechanical properties under compressive stresses; material properties at elevated temperatures; influence of irradiation on mechanical and physical properties; production standards and quality control. The state of the research and the available data of the material testing program are reported

  6. Theory of hot particle stability

    International Nuclear Information System (INIS)

    Berk, H.L.; Wong, H.V.; Tsang, K.T.

    1986-10-01

    The investigation of stabilization of hot particle drift reversed systems to low frequency modes has been extended to arbitrary hot beta, β/sub H/ for systems that have unfavorable field line curvature. We consider steep profile equilibria where the thickness of the pressure drop, Δ, is less than plasma radius, r/sub p/. The analysis describes layer modes which have mΔ/r/sub p/ 2/3. When robust stability conditions are fulfilled, the hot particles will have their axial bounce frequency less than their grad-B drift frequency. This allows for a low bounce frequency expansion to describe the axial dependence of the magnetic compressional response

  7. Study of tensile test behavior of austenitic stainless steel type 347 seamless thin-walled tubes in cold worked condition

    Energy Technology Data Exchange (ETDEWEB)

    Terui, Clarice, E-mail: clarice.terui@marinha.mil.br [Centro Tecnológico da Marinha em São Paulo (CINA/CTMSP), Iperó, SP (Brazil). Centro Industrial Nuclear da Marinha; Lima, Nelson B. de, E-mail: nblima@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNE-SP), Sao Paulo, SP (Brazil)

    2017-07-01

    These austenitic stainless steel type 347 seamless thin-walled tubes are potential candidates to be used in fuel elements of nuclear power plants (as PWR - Pressurized Water Reactor). So, their metallurgical condition and mechanical properties, as the tensile strength and yield strength, normally are very restrict in demanding project and design requirements. Several full size tensile tests at room temperature and high temperature (315 deg C) were performed in these seamless tubes in cold-worked condition. The results of specified tensile and yield strengths were achieved but the elongation of the tube, in the geometry of the component, could not be measured at high temperature due to unconventional mode of rupture (helical mode without separation of parts). The average value of elongation was obtained from stress-strain curves of hot tensile tests and was around 5%. The results obtained in this research show that this behavior of the full size tensile test samples of thin-walled tube (wall thickness less than 0.5 mm) in high temperature (315°C) is due to the combination of the manufacturing process, the material (crystallographic structure and chemical composition) and the final geometry of the component. In other words, the strong crystallographic texture of material induced by tube drawing process in addition with the geometry of the component are responsible for the behavior in hot uniaxial tensile tests. (author)

  8. Development of core hot spot evaluation method for decay heat removal by natural circulation under transient conditions in sodium-cooled fast reactor

    International Nuclear Information System (INIS)

    Ohshima, Hiroyuki; Doda, Norihiro; Kamide, Hideki; Watanabe, Osamu; Ohkubo, Yoshiyuki

    2010-01-01

    Toward the commercialization of fast reactors, a design study of Japan Sodium-cooled Fast Reactor (JSFR) is being performed. In this design study, the adoption of decay heat removal system operated by fully natural circulation is being examined from viewpoints of economic competitiveness and passive safety. This paper describes a new evaluation method of core hot spot under transient conditions from forced to natural circulation operations that is necessary for confirming feasibility of the fully natural circulation decay heat removal system. The new method consists of three analysis steps in order to include effects of thermal hydraulic phenomena particular to the natural circulation decay heat removal, e.g., flow redistribution in fuel assemblies caused by buoyancy force, and therefore it enables more rational hot spot evaluation rather than conventional ones. This method was applied to a hot spot evaluation of loss-of-external-power event and the result was compared with those by conventional 1D and detailed 3D simulations. It was confirmed that the proposed method can estimate the hot spot with reasonable degree of conservativeness. (author)

  9. Demand-specific work ability, poor health and working conditions in middle-aged full-time employees.

    Science.gov (United States)

    Nabe-Nielsen, Kirsten; Thielen, Karsten; Nygaard, Else; Thorsen, Sannie Vester; Diderichsen, Finn

    2014-07-01

    We investigated the prevalence of reduced demand-specific work ability, its association with age, gender, education, poor health, and working conditions, and the interaction between poor health and working conditions regarding reduced demand-specific work ability. We used cross-sectional questionnaire data from 3381 full-time employees responding to questions about vocational education, job demands and social support (working conditions), musculoskeletal pain (MSP) and major depression (MD) (poor health) and seven questions about difficulty managing different job demands (reduced demand-specific work ability). Reduced demand-specific work ability varied from 9% to 19% among the 46-year old and from 11% to 21% among the 56-year old. Age was associated with two, gender with four, and education with all measures of reduced demand-specific work ability. MSP was associated with four and MD was associated with six measures of reduced demand-specific work ability. We found no interaction between working conditions and poor health regarding reduced demand-specific work ability. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  10. Perception of orchestral musicians about work environment and conditions

    Directory of Open Access Journals (Sweden)

    Clarissa Stefani Teixeira

    2014-04-01

    Full Text Available The objective of this study was to investigate the perception of 11 orchestral string (viola and violin musicians of both genders with respect to their work environment and conditions. We applied a questionnaire with demographic information and the scale Profile of Work Environment and Working Conditions by Nahas et al. (2009, which analyzes the following components: physical environment, social environment, development and professional achievement, salary and benefits, and social relevance. The social environment component presented the highest score - 8.00 (1.50 points, followed by professional achievement - 7.11 (1.96 points, and physical environment - 6.89 (0.93 points. The salary and benefits provided by the orchestra presented the lowest score - 6.78 (1.56 points. In general, the musicians showed positive perceptions of the components related to work environment and working conditions. However, remuneration and social relevance are work bases that could contribute to improve the working conditions of these professionals.

  11. Depression, quality of life, work productivity, resource use, and costs among women experiencing menopause and hot flashes: a cross-sectional study.

    Science.gov (United States)

    Dibonaventura, Marco Dacosta; Wagner, Jan-Samuel; Alvir, Jose; Whiteley, Jennifer

    2012-01-01

    To examine the effect of depression on health-related quality of life, work productivity, resource use, and costs among women experiencing menopausal symptoms, including hot flashes. The study included data from the 2005 US National Health and Wellness Survey (N = 41,184), a cross-sectional, Internet-based survey representative of the adult US population. Among women who reported experiencing menopausal symptoms, including hot flashes, women who reported experiencing depression in the last year (n = 1,165) were compared with women who did not report experiencing depression in the last year (n = 2,467), controlling for demographic and health characteristics. Outcome measures included health-related quality of life (Medical Outcomes Study 8-item Short-Form Health Survey [SF-8]), work productivity within the past 7 days, self-reported health care resource use within the past 6 months, and indirect and direct costs. Women experiencing depression were significantly more likely to be white, to be unemployed, to be uninsured, to currently smoke, to not exercise, and to be obese (all P women experiencing depression reported significantly lower mental (39.66 vs 50.85, P work (5.31% vs 2.80%, P work (25.00% vs 14.32%, P women experiencing depression. The numbers of physician visits (2.47 vs 1.77, P women experiencing depression. Per woman per year indirect and direct costs were $3,066 and $1,075 higher, respectively, for women experiencing depression compared with those not experiencing depression. Approximately one-third of women experiencing menopausal symptoms, including hot flashes, also reported experiencing depression. These women reported significantly worse quality of life and significantly greater work productivity loss, health care resource use, and costs. Given the prevalence and burden, these findings suggest that proper assessment and management of depressive symptoms among women with menopause may have an important humanistic and economic benefit.

  12. Mechanical behavior and modelisation of Ti-6Al-4V titanium sheet under hot stamping conditions

    Science.gov (United States)

    Sirvin, Q.; Velay, V.; Bonnaire, R.; Penazzi, L.

    2017-10-01

    The Ti-6Al-4V titanium alloy is widely used for the manufacture of aeronautical and automotive parts (solid parts). In aeronautics, this alloy is employed for its excellent mechanical behavior associated with low density, outstanding corrosion resistance and good mechanical properties up to 600°C. It is especially used for the manufacture of fuselage frames, on the pylon for carrying out the primary structure (machining forged blocks) and the secondary structure in sheet form. In this last case, the sheet metal forming can be done through various methods: at room temperature by drawing operation, at very high temperature (≃900°C) by superplastic forming (SPF) and at intermediate temperature (≥750°C) by hot forming (HF). In order to reduce production costs and environmental troubles, the cycle times reduction associated with a decrease of temperature levels are relevant. This study focuses on the behavior modelling of Ti-6Al-4V alloy at temperatures above room temperature to obtained greater formability and below SPF condition to reduce tools workshop and energy costs. The displacement field measurement obtained by Digital Image Correlation (DIC) is based on innovative surface preparation pattern adapted to high temperature exposures. Different material parameters are identified to define a model able to predict the mechanical behavior of Ti-6Al-4V alloy under hot stamping conditions. The hardening plastic model identified is introduced in FEM to simulate an omega shape forming operation.

  13. [Risk of certain obstetric pathologies in women employed in working conditions non-complying with the current legal status on work load and working conditions appropriate for pregnant women].

    Science.gov (United States)

    Makowiec-Dabrowska, Teresa; Hanke, Wojciech; Sobala, Wojciech; Radwan-Włodarczyk, Zyta; Koszada-Włodarczyk, Wiesława

    2003-01-01

    The aim of the study was to define the incidence of prematurity and small-for-gestational age (SGA) infants in occupationally involved pregnant women, and to find out how far working conditions departing from binding regulations contribute to the risk of the development of these pathologies. The study was carried out on a representative sample of 3050 women employed for longer than one week during pregnancy in the Łódź district. An interview conducted with the subjects few days after delivery was the source of information about working conditions. The obtained information was compared with the real situation in about 10% of randomly selected workposts. A high level of consistence was observed. The study revealed that almost 60% of women work in conditions, which do not comply with the Labor Code provisions setting working conditions permissible for pregnant women. In the study group, 4.68% of prematurity and 6.15% of SGA were recorded. A 66% excess in the risk of delivering SGA infants in case of at least one factor not complying with regulations was revealed. The excess was growing with the increased number of departures from regulations and continuation of employment during pregnancy. It was estimated that the number of SGA cases would decrease by 28% if the working conditions would have met the requirements. A prolonged time of work, local vibration for > 4h/shift, forced work pace, excessive effort and forced body position during the work performance contributed mostly to the risk of pathology. Interestingly, the risk of premature delivery was lower by about 40% in women working in unsatisfactory conditions, which is attributed to termination of work immediately after the occurrence of pregnancy-threatening symptoms. Only those women whose pregnancy was not threatened with pathology could continue their work. The study revealed a quite large number of workplaces not complying with regulations on working conditions permissible for pregnant women. Therefore

  14. Semi-Supervised Transductive Hot Spot Predictor Working on Multiple Assumptions

    KAUST Repository

    Wang, Jim Jing-Yan; Almasri, Islam; Shi, Yuexiang; Gao, Xin

    2014-01-01

    of the transductive semi-supervised algorithms takes all the three semisupervised assumptions, i.e., smoothness, cluster and manifold assumptions, together into account during learning. In this paper, we propose a novel semi-supervised method for hot spot residue

  15. Decommissioning of the Risoe Hot Cell facility

    International Nuclear Information System (INIS)

    Carlsen, H.

    1993-10-01

    A concise description of the current status of the decommissioning of the hot cell capacity at Risoe National Laboratory is given in this 6th periodic report covering January 1st to June 30th, 1993. All registered and safeguarded fissile material has been removed and the task of cutting and packing scrap material and experimental equipment from the concrete cell line has been completed. Concrete cells 5 and 6 have been finally cleaned and the master slave manipulators removed from them. The major part of the contamination on the shutters and shutter houses were on their horizontal planes and the main contaminant was 137 Cs. Here the surfaces were cleaned by wiping with wet cloths. The method is described. Tables illustrating the resulting contamination levels are included, the density is now low on the shutters. The method of final inn-cell cleaning is explained, and here again tables represent the resulting contamination levels. The work on ''hot spot'' removal and remote cleaning by vacuuming continues on the remaining cells. A collective dose of ca. 16.3 man-mSv was ascribed to 18 persons in the first half of 1993, arising mainly from in-cell work and waste handling. To sum up, the main results from this period are successful removal of last waste from the cells, remote cleaning of cells 2 and 3, final condition for all shutters and shutter housings and final condition for cells 5 and 6. Tables illustrate measured dose rates in detail. (AB)

  16. Women waste pickers: living conditions, work, and health.

    Science.gov (United States)

    Coelho, Alexa Pupiara Flores; Beck, Carmem Lúcia Colomé; Fernandes, Marcelo Nunes da Silva; Freitas, Natiellen Quatrin; Prestes, Francine Cassol; Tonel, Juliana Zancan

    2016-09-29

    To know the elements of work, health, and living conditions of women who pick recyclable waste and are members of a waste cooperative in a town of the state of Rio Grande do Sul, Brazil. This is a qualitative, exploratory and descriptive study with seven subjects. Data were collected through participative observation, semi structured interview, and a focus group from July to August of 2013. The data were subjected to content analysis. The following thematic categories emerged: Women's work, informality and precariousness; Experiences of job satisfaction; and Working conditions and health: experiences with accidents, illness and health services. It was concluded that the women who collect recyclable material are exposed to precarious work conditions and potential health risks, such as work overload, accidents, illness, and social insecurity, and that nurses are responsible for promoting actions that ensure the health and inclusion of these workers.

  17. Professions and Working Conditions Associated With Community-Acquired Pneumonia.

    Science.gov (United States)

    Almirall, Jordi; Serra-Prat, Mateu; Bolíbar, Ignasi; Palomera, Elisabet; Roig, Jordi; Boixeda, Ramon; Bartolomé, Maria; de la Torre, Mari; Parra, Olga; Torres, Antoni

    2015-12-01

    Community-acquired pneumonia (CAP) is not considered a professional disease, and the effect of different occupations and working conditions on susceptibility to CAP is unknown. The aim of this study is to determine whether different jobs and certain working conditions are risk factors for CAP. Over a 1-year period, all radiologically confirmed cases of CAP (n=1,336) and age- and sex-matched controls (n=1,326) were enrolled in a population-based case-control study. A questionnaire on CAP risk factors, including work-related questions, was administered to all participants during an in-person interview. The bivariate analysis showed that office work is a protective factor against CAP, while building work, contact with dust and sudden changes of temperature in the workplace were risk factors for CAP. The occupational factor disappeared when the multivariate analysis was adjusted for working conditions. Contact with dust (previous month) and sudden changes of temperature (previous 3 months) were risk factors for CAP, irrespective of the number of years spent working in these conditions, suggesting reversibility. Some recent working conditions such as exposure to dust and sudden changes of temperature in the workplace are risk factors for CAP. Both factors are reversible and preventable. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

  18. Pay, working conditions, and teacher quality.

    Science.gov (United States)

    Hanushek, Eric A; Rivkin, Steven G

    2007-01-01

    Eric Hanushek and Steven Rivkin examine how salary and working conditions affect the quality of instruction in the classroom. The wages of teachers relative to those of other college graduates have fallen steadily since 1940. Today, average wages differ little, however, between urban and suburban districts. In some metropolitan areas urban districts pay more, while in others, suburban districts pay more. But working conditions in urban and suburban districts differ substantially, with urban teachers reporting far less administrator and parental support, worse materials, and greater student problems. Difficult working conditions may drive much of the difference in turnover of teachers and the transfer of teachers across schools. Using rich data from Texas public schools, the authors describe in detail what happens when teachers move from school to school. They examine how salaries and student characteristics change when teachers move and also whether turnover affects teacher quality and student achievement. They note that both wages and student characteristics affect teachers' choices and result in a sorting of teachers across schools, but they find little evidence that teacher transitions are detrimental to student learning. The extent to which variations in salaries and working conditions translate into differences in the quality of instruction depends importantly on the effectiveness of school personnel policies in hiring and retaining the most effective teachers and on constraints on both entry into the profession and the firing of low performers. The authors conclude that overall salary increases for teachers would be both expensive and ineffective. The best way to improve the quality of instruction would be to lower barriers to becoming a teacher, such as certification, and to link compensation and career advancement more closely with teachers' ability to raise student performance.

  19. Work disability resulting from chronic health conditions.

    Science.gov (United States)

    Lerner, Debra; Allaire, Saralynn H; Reisine, Susan T

    2005-03-01

    To describe current programs and policies for addressing work disability among adults with chronic health conditions, and to identify opportunities for new research aimed at reducing the problem. The authors conducted secondary data analysis and a literature review. Millions of Americans with a chronic health condition have a work disability or are at risk of developing one. This public health problem is costing hundreds of billions of dollars a year nationally in lost productivity and diminishing the quality of life of millions of Americans. The medical care system, employers, and government--three traditional sources of help for adults with chronic health problems--are not sufficiently oriented toward the primary or secondary prevention of work disability. New research is urgently needed to reduce the burden of work disability on individuals and society.

  20. Nurse practitioners' work hours and overtime: How much, and under what working conditions?

    Science.gov (United States)

    Bae, Sung-Heui; Champion, Jane Dimmitt

    2016-03-01

    To explore the nature and prevalence of nurse practitioner (NP) overtime, work hours, and their relationship to practice within NP work conditions. A secondary analysis of data extracted from the 2012 National Sample Survey of Nurse Practitioners. The focus in this study was on data from NPs in active practice in clinical settings. The final analytic sample consisted of 9010 NPs. NPs working in hospitals and long-term care settings tended to work more than 40 h/week (p work more hours per week than those who did not. Regarding the type of relationships with physicians, NPs who worked more than 40 h/week either had hierarchical relationships with them (p work hours/overtime and work conditions related to longer work hours. Further study is indicated to assess the potential impact of work hours/overtime on NP roles and patient outcomes. ©2015 American Association of Nurse Practitioners.

  1. Hot-carrier effects in MOS devices

    CERN Document Server

    Takeda, Eiji; Miura-Hamada, Akemi

    1995-01-01

    The exploding number of uses for ultrafast, ultrasmall integrated circuits has increased the importance of hot-carrier effects in manufacturing as well as for other technological applications. They are rapidly movingout of the research lab and into the real world.This book is derived from Dr. Takedas book in Japanese, Hot-Carrier Effects, (published in 1987 by Nikkei Business Publishers). However, the new book is much more than a translation. Takedas original work was a starting point for developing this much more complete and fundamental text on this increasingly important topic. The new work

  2. Influences of working conditions on the performance of sign ...

    African Journals Online (AJOL)

    Findings showed that poor working conditions such as delay in promotion and salary payment and unattractive office accommodation have significant adverse influence on working performance of both teachers and interpreters. Teachers significantly felt the disturbing influence of poor working conditions on their job ...

  3. Microstructural characterization by electron backscatter diffraction of a hot worked Al-Cu-Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Cepeda-Jimenez, C.M., E-mail: cm.cepeda@cenim.csic.es [Department of Physical Metallurgy, CENIM, CSIC, Av. Gregorio del Amo 8, 28040 Madrid (Spain); Hidalgo, P.; Carsi, M.; Ruano, O.A.; Carreno, F. [Department of Physical Metallurgy, CENIM, CSIC, Av. Gregorio del Amo 8, 28040 Madrid (Spain)

    2011-03-25

    Research highlights: {yields} The most favourable conditions for hot workability have been determined. {yields} EBSD was employed to characterize the obtained microtexture and microstructure. {yields} The Al 2024 alloy torsion tested at 408 deg. C and 2.1 s{sup -1} showed maximum ductility. {yields} Solid solution and fine precipitates favour a fine microstructure at 408 deg. C. {yields} The increase in test temperature to 467 deg. C produces a sharp decrease in ductility. - Abstract: Hot torsion tests to fracture to simulate thermomechanical processing were carried out on a solution-treated Al-Cu-Mg alloy (Al 2024-T351) at constant temperature. Torsion tests were conducted in the range 278-467 deg. C, and at two strain rates, 2.1 and 4.5 s{sup -1}. Electron backscatter diffraction (EBSD) was employed to characterize the microtexture and microstructure before and after testing. The microstructural evolution during torsion deformation at different temperatures and strain rate conditions determines the mechanical properties at room temperature of the Al 2024 alloy since grain refining, dynamic precipitation and precipitate coalescence occur during the torsion test. These mechanical properties were measured by Vickers microhardness tests. At 408 deg. C and 2.1 s{sup -1} the optimum combination of solid solution and incipient precipitation gives rise to maximum ductility and large fraction of fine and misoriented grains (f{sub HAB} = 54%). In contrast, the increase in test temperature to 467 deg. C produces a sharp decrease in ductility, attributed to the high proportion of alloying elements in solid solution. Both the stress-strain flow curves obtained by torsion tests and the final microstructures are a consequence of recovery phenomena and the dynamic nature of the precipitation process taking place during deformation.

  4. Microstructural characterization by electron backscatter diffraction of a hot worked Al-Cu-Mg alloy

    International Nuclear Information System (INIS)

    Cepeda-Jimenez, C.M.; Hidalgo, P.; Carsi, M.; Ruano, O.A.; Carreno, F.

    2011-01-01

    Research highlights: → The most favourable conditions for hot workability have been determined. → EBSD was employed to characterize the obtained microtexture and microstructure. → The Al 2024 alloy torsion tested at 408 deg. C and 2.1 s -1 showed maximum ductility. → Solid solution and fine precipitates favour a fine microstructure at 408 deg. C. → The increase in test temperature to 467 deg. C produces a sharp decrease in ductility. - Abstract: Hot torsion tests to fracture to simulate thermomechanical processing were carried out on a solution-treated Al-Cu-Mg alloy (Al 2024-T351) at constant temperature. Torsion tests were conducted in the range 278-467 deg. C, and at two strain rates, 2.1 and 4.5 s -1 . Electron backscatter diffraction (EBSD) was employed to characterize the microtexture and microstructure before and after testing. The microstructural evolution during torsion deformation at different temperatures and strain rate conditions determines the mechanical properties at room temperature of the Al 2024 alloy since grain refining, dynamic precipitation and precipitate coalescence occur during the torsion test. These mechanical properties were measured by Vickers microhardness tests. At 408 deg. C and 2.1 s -1 the optimum combination of solid solution and incipient precipitation gives rise to maximum ductility and large fraction of fine and misoriented grains (f HAB = 54%). In contrast, the increase in test temperature to 467 deg. C produces a sharp decrease in ductility, attributed to the high proportion of alloying elements in solid solution. Both the stress-strain flow curves obtained by torsion tests and the final microstructures are a consequence of recovery phenomena and the dynamic nature of the precipitation process taking place during deformation.

  5. A Proposal of a Constitutive Description for Aluminium Alloys in Both Cold and Hot Working

    Directory of Open Access Journals (Sweden)

    Javier León

    2016-10-01

    Full Text Available The most important difficulties when the behaviour of a part that is subjected to external mechanical forces is simulated deal with the determination of both the material thermo-mechanical properties and its boundary conditions. The accuracy of the results obtained from the simulation is directly related to the knowledge of the flow stress curve. Therefore, the determination of a material flow rule which is valid for both a wide temperature range and different initial deformation conditions in the starting material presents a great deal of interest when simulation results close to the experimental values are required to be obtained. In this present study, a novel flow stress curve is proposed that is able to accurately predict the behaviour of both materials with no previous accumulated strain and materials that have been previously subjected to severe plastic deformation processes. Moreover, it is possible to use it both for hot and cold working. The results are analysed in a wide test temperature range, which varies from room temperature to 300 °C, and from material previously processed by angular channel extrusion or with no previous strain accumulated. It is shown that the flow rule proposed is effective to model the material behaviour in a wide temperature range and it makes it possible to take the recrystallization phenomena that appear in previously deformed materials into account. In addition, the results obtained are compared with those predicted by other flow rules that exist in the prior literature. Furthermore, the study is complemented with finite element simulations and with a comparison between simulation and experimental results.

  6. Physician job satisfaction and working conditions in Japan.

    Science.gov (United States)

    Wada, Koji; Arimatsu, Mayuri; Higashi, Toshiaki; Yoshikawa, Toru; Oda, Susumu; Taniguchi, Hatsumi; Kawashima, Masatoshi; Aizawa, Yoshiharu

    2009-01-01

    The aim of this study was to determine factors of working conditions associated with job satisfaction among physicians in Japan. We sent a questionnaire to all the physicians who graduated from a medical school in Japan. Physicians who were satisfied with their job were determined as those who selected "very satisfied" and "satisfied" in response to the question: "Overall, are you satisfied with your job?" Working conditions were determined from 10 different aspects: income fairness, hospital resources, career satisfaction, difficulty in patient care, lack of personal time, administrative work, workload, and relationships with physician colleagues, staff and patients. Logistic regression analysis was used to explore the association between working conditions and job satisfaction. Among the respondents, 209 (55.4%) men and 62 (61.4%) women were determined to be satisfied with their job. Job satisfaction was associated with income fairness for both men (corrected odds ratio 1.31, 95% confidence interval 1.09 to 1.47) and women (1.35, 1.05 to 1.53). For men, job satisfaction was associated with good hospital resources (1.45, 1.29 to 1.57), high career satisfaction (1.41, 1.23 to 1.57), good relationships with physician colleagues (1.33, 1.12 to 1.49), and good relationships with hospital staff (1.28, 1.07 to 1.45). For women, job satisfaction was associated with good relationships with patients (1.41, 1.07 to 1.56). Certain working conditions were important factors for job satisfaction among physicians. These factors should be discussed for improving working conditions.

  7. Ab initio study of hot electrons in GaAs

    OpenAIRE

    Bernardi, Marco; Vigil-Fowler, Derek; Ong, Chin Shen; Neaton, Jeffrey B.; Louie, Steven G.

    2015-01-01

    Hot carrier dynamics critically impacts the performance of electronic, optoelectronic, photovoltaic, and plasmonic devices. Hot carriers lose energy over nanometer lengths and picosecond timescales and thus are challenging to study experimentally, whereas calculations of hot carrier dynamics are cumbersome and dominated by empirical approaches. In this work, we present ab initio calculations of hot electrons in gallium arsenide (GaAs) using density functional theory and many-body perturbation...

  8. Disturbance Impacts on Thermal Hot Spots and Hot Moments at the Peatland-Atmosphere Interface

    Science.gov (United States)

    Leonard, R. M.; Kettridge, N.; Devito, K. J.; Petrone, R. M.; Mendoza, C. A.; Waddington, J. M.; Krause, S.

    2018-01-01

    Soil-surface temperature acts as a master variable driving nonlinear terrestrial ecohydrological, biogeochemical, and micrometeorological processes, inducing short-lived or spatially isolated extremes across heterogeneous landscape surfaces. However, subcanopy soil-surface temperatures have been, to date, characterized through isolated, spatially discrete measurements. Using spatially complex forested northern peatlands as an exemplar ecosystem, we explore the high-resolution spatiotemporal thermal behavior of this critical interface and its response to disturbances by using Fiber-Optic Distributed Temperature Sensing. Soil-surface thermal patterning was identified from 1.9 million temperature measurements under undisturbed, trees removed and vascular subcanopy removed conditions. Removing layers of the structurally diverse vegetation canopy not only increased mean temperatures but it shifted the spatial and temporal distribution, range, and longevity of thermal hot spots and hot moments. We argue that linking hot spots and/or hot moments with spatially variable ecosystem processes and feedbacks is key for predicting ecosystem function and resilience.

  9. Hot rolling of chromium - nickel - manganese stainless steel containing nitrogen and boron

    International Nuclear Information System (INIS)

    Khorosh, V.A.; Bulat, S.I.; Mukhina, M.A.; Sorokina, N.A.; Yushchenko, K.A.; Tsentral'nyj Nauchno-Issledovatel'skij Inst. Chernoj Metallurgii, Moscow; AN Ukrainskoj SSR, Kiev. Inst. Ehlektrosvarki)

    1976-01-01

    The strength of stainless steel of the 03Kh2ON16AG6 type increases perceptibly with an increase in the nitrogen content from 0.11 to 0.37%. At the same time, however, its ductility in the region of hot deformation temperatures (red brittleness range of 800 to 1,000 deg C) decreases. Microalloying with boron (0.002 to 0.005% by calculation) permits enhancing the hot ductility to an acceptable level without adversely affecting the working properties. The mechaniusm of boron effect is analyzed. The temperature at which ingots are heated prior to rolling to achieve the desired effect must be sufficiently low. Optimum condition for two stage heating of 6.2-ton ingots are recommeded

  10. Impact of the crisis on working conditions

    OpenAIRE

    Van Gyes, Guy; Szekér, Lise

    2013-01-01

    The economic and financial crisis is affecting working conditions across EU Member States and Norway in different ways and scope. Yet the pattern is of less work, reduced overall working time, less overtime, rising job insecurity, less choice for workers, wage freezes and wage cuts. There is also greater work intensity, deterioration of work–life balance, increasing stress at work, greater risk of harassment/bullying, less absenteeism, growth in the informal economy and changes to migration p...

  11. Optimization of fermentation conditions for cellulases production by Bacillus licheniformis MVS1 and Bacillus sp. MVS3 isolated from Indian hot spring

    Directory of Open Access Journals (Sweden)

    Somen Acharya

    2012-08-01

    Full Text Available The aim of this work was to study the effect of some nutritional and environmental factors on the production of cellulases, in particular endoglucanase (CMCase and exoglucanases (FPase from Bacillus licheniformis MVS1 and Bacillus sp. MVS3 isolated from an Indian hot spring. The characterization study indicated that the optimum pH and temperature value was 6.5 to 7.0 and 50-55°C, respectively. Maximum cellulases production by both the isolates was detected after 60 h incubation period using wheat and rice straw. The combination of inorganic and organic nitrogen source was suitable for cellulases production. Overall, FPase production was much higher than CMCase production by both of the strains. Between the two thermophiles, the cellulolytic activity was more in B.licheniformis MVS1 than Bacillus sp. MVS3 in varying environmental and nutritional conditions.

  12. On the accuracy of current TCAD hot carrier injection models in nanoscale devices

    Science.gov (United States)

    Zaka, Alban; Rafhay, Quentin; Iellina, Matteo; Palestri, Pierpaolo; Clerc, Raphaël; Rideau, Denis; Garetto, Davide; Dornel, Erwan; Singer, Julien; Pananakakis, Georges; Tavernier, Clément; Jaouen, Hervé

    2010-12-01

    In this work, the hot electron injection models presently available for technology support have been investigated within the context of the development of advanced embedded non-volatile memories. The distribution functions obtained by these models (namely the Fiegna Model - FM [1], the Lucky Electron Model - LEM [2] and the recently implemented Spherical Harmonics Expansion of the Boltzman's Transport Equation - SHE [3]), have been systematically compared to rigorous Monte Carlo (MC) results [4], both in homogeneous and device conditions. Gate-to-drain current ratio and gate current density simulation has also been benchmarked in device simulations. Results indicate that local models such as FM, can partially capture the channel hot electron injection, at the price of model parameter adjustments. Moreover, at least in the device and field condition considered in this work, an overall better agreement with MC simulations has been obtained using the 1st order SHE, even without any particular fitting procedure. Extending the results presented in [3] by exploring shorter gate lengths and addressing the floating gate voltage dependence of the gate current, this work shows that the SHE method could contribute to bridge the gap between the rigorous but time consuming MC method and less rigorous but suitable TCAD local models.

  13. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Science.gov (United States)

    2010-02-23

    ... DEPARTMENT OF AGRICULTURE Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest... Rangeland Project area. The analysis will determine if a change in management direction for livestock grazing is needed to move existing resource conditions within the Monitor-Hot Creek Rangeland Project area...

  14. 'Hot' particles in the atmosphere (Vilnius, 1986)

    International Nuclear Information System (INIS)

    Lujanas, V.; Shpirkauskaite, N.

    1992-01-01

    After the Chernobyl accident in the atmosphere above Vilnius the alpha-and beta- 'hot' particles were discovered. The amount of particles and their size were measured by the alpha-radiography. After the exposition of nuclear plates the 'auroras' of the beta hot particles were of the size 0.37-22.2 μm. The change in time of the beta- 'hot' particles amount in the ground level air from the 25th of April to the 9th of May, 1986 was given. The amount of this particles deposited in the adult man respiratory tract was calculated. The energy of the discovered 8 'hot' alpha-particles ranged from 4.2 to 6.6 MeV. All the samples in which alpha- 'hot' particles found were taken in anticyclone conditions. (author). 1 tab., 1 ref

  15. Modeling patterns of hot water use in households

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, James D.; Liu, Xiaomin; McMahon, James E.; Dunham, Camilla; Shown, Leslie J.; McCure, Quandra T.

    1996-01-01

    This report presents a detailed model of hot water use patterns in individual households. The model improves upon an existing model by including the effects of four conditions that were previously unaccounted for: the absence of a clothes washer; the absence of a dishwasher; a household consisting of seniors only; and a household that does not pay for its own hot water use. Although these four conditions can significantly affect residential hot water use, and have been noted in other studies, this is the first time that they have been incorporated into a detailed model. This model allows detailed evaluation of the impact of potential efficiency standards for water heaters and other market transformation policies.

  16. Hot gas cleaning, a targeted project

    Energy Technology Data Exchange (ETDEWEB)

    Romey, I. [University of Essen, Essen (Germany)

    1998-11-01

    Advanced hot gas cleaning systems will play a key role in future integrated combined cycle technologies. IGCC demonstration plants in operation or under construction are at present equipped with conventional wet gas scrubbing and cleaning systems. Feasibility studies for those IGCC plants have shown that the total efficiency of the processes can be improved using hot gas cleaning systems. However, this technology has not been developed and tested at a technical scale. Six well-known European industrial companies and research centres jointly worked together since January 1996 on a Targeted Project `Hot Gas Cleaning` to investigate and develop new hot gas cleaning systems for advanced clean coal power generation processes. In addition project work on chemical analysis and modelling was carried out in universities in England and Germany. The latest main findings were presented at the workshop. The main project aims are summarised as follows: to increase efficiency of advanced power generation processes; to obtain a reduction of alkalis and environmental emissions e.g. SO{sub 2}, NO{sub x}, CO{sub 2} and dust; and to develop the design basis for future industrial plants based on long-term operation of laboratory, pilot and demo-plants. To cover a range of possible process routes for future hot gas cleaning systems the following research programme is under investigation: removal of trace elements by different commercial and self developed sorbents; gas separation by membranes; separation of gas turbine relevant pollutants by hot filter dust and; H{sub 2}S removal and gas dedusting at high temperatures. 13 figs.

  17. Effect of Shading on Physiological, Biochemical and Behaviour Changes in Crossbred Calves Under Hot Climatic Conditions

    International Nuclear Information System (INIS)

    Teama, F.E.I.; Gad, A.E.; El-Tarabany, A.A.

    2012-01-01

    The purpose of this study was to investigate the importance and the effect of shading and non-shading house on physiological changes, body weight (BW), average daily gain (ADG), total antioxidant and thyroid hormones in crossbred calves under hot conditions. Thirty six growing crossbred calves (Friesian x Baladi) aged 8-10 months were divided into two groups (each 18 calves); the first group was maintained in shaded house and the second in house without shade (climatic house). The period of study was 79 days during hot conditions. Performance variables (BW, ADG) were measured and the blood samples were collected to assess some biochemical parameters including antioxidants such as total antioxidant (TA), catalase (CAT), total protein, thyroid hormones (T3, T4) and immunoglobulin factor (IgG). Respiration rates and behaviour parameters (feeding, drinking, standing, lying and agonistic) were also measured during the study. The data indicated that the shaded calves had higher ADG (P<0.05) and final BW than non-shaded ones. Also, a significant improvement in total protein levels and globulins were recorded in shaded house calves as compared to non-shaded ones. The same result was obtained for T3 level whereas non-significant changes were observed for T4 level as well as the level of IgG at different times. The present data indicated that using shaded house will decrease the effect of heat stress on calves which will increase the animal performance through improving BW and ADG as well as some biochemical parameters in addition to T3 hormonal level.

  18. Implementation of a cabin X-rays in hot cell

    International Nuclear Information System (INIS)

    Berduola, F.; Caral, L.

    2001-01-01

    The Fabrice process for the reconstituted short length irradiated rods in a hot cell was developed by the CEA especially for power ramp testing. This technique requires intricate operations in a hot cell with specially adapted equipment and great skill people. And end plug is inserted under pressure and fitted to the opening end of a cladding tube. The meeting surfaces of the en plug and the opening end are welded by a TIG (tunsten inert gas) process. Nevertheless, somo predominate defects may occur in the end plug weld joints, such as lack of penetration and cavity. So, particular attention must be paid to non-destructive examination in particular X-ray control of welding areas. A radioscopy technique has been applied to the control of TIG welds of the end plugs to rod assemblies in a hot cell mock-up to be tested under realistic geometric conditions. This X-rays method enables immediate monitoring of any welding defaults on a TV screen. A remote positioning system for the Fabrice rod is being developed to position fuel rods below a X-ray source. Radioscopy pictures will be recorded during remote positioning of the rod movement. This document presents the modifications achieved by the constructor in cooperation with our laboratory staff, concerning the nuclearization of the apparatus as well as its implementation in the shielded hot cell n paragraph 2 of the CEA-DEC/SLS/LECA Laboratory in Cadarache. Hot operation of the rod positioner is planned for september 2022 because of recent refurbishing works in the plant. (Author)

  19. BEAVRS full core burnup calculation in hot full power condition by RMC code

    International Nuclear Information System (INIS)

    Liu, Shichang; Liang, Jingang; Wu, Qu; Guo, JuanJuan; Huang, Shanfang; Tang, Xiao; Li, Zeguang; Wang, Kan

    2017-01-01

    Highlights: • TMS and thermal scattering interpolation were developed to treat cross sections OTF. • Hybrid coupling system was developed for HFP burnup calculation of BEAVRS benchmark. • Domain decomposition was applied to handle memory problem of full core burnup. • Critical boron concentration with burnup by RMC agrees with the benchmark results. • RMC is capable of multi-physics coupling for simulations of nuclear reactors in HFP. - Abstract: Monte Carlo method can provide high fidelity neutronics analysis of different types of nuclear reactors, owing to its advantages of the flexible geometry modeling and the use of continuous-energy nuclear cross sections. However, nuclear reactors are complex systems with multi-physics interacting and coupling. MC codes can couple with depletion solver and thermal-hydraulics (T/H) codes simultaneously for the “transport-burnup-thermal-hydraulics” coupling calculations. MIT BEAVRS is a typical “transport-burnup-thermal-hydraulics” coupling benchmark. In this paper, RMC was coupled with sub-channel code COBRA, equipped with on-the-fly temperature-dependent cross section treatment and large-scale detailed burnup calculation based on domain decomposition. Then RMC was applied to the full core burnup calculations of BEAVRS benchmark in hot full power (HFP) condition. The numerical tests show that domain decomposition method can achieve the consistent results compared with original version of RMC while enlarging the computational burnup regions. The results of HFP by RMC agree well with the reference values of BEAVRS benchmark and also agree well with those of MC21. This work proves the feasibility and accuracy of RMC in multi-physics coupling and lifecycle simulations of nuclear reactors.

  20. Residential solar hot water

    Energy Technology Data Exchange (ETDEWEB)

    1982-06-01

    This report examines the feasibility of using solar energy to preheat domestic water coming from the city supply at a temperature of approximately 4{degree}C. Four solar collectors totalling 7 m{sup 2} were installed on a support structure facing south at an angle of 60{degree} from the horizontal. The system worked most efficiently in the spring and early summer when the combination of long hours of sunshine, clean air and clear skies allowed for maximum availability of solar radiation. Performance dropped in late summer and fall mainly due to cloudier weather conditions. The average temperature in the storage tank over the 10 months of operation was 42{degree}C, ranging from a high of 83{degree}C in July to a low of 6{degree}C in November. The system provided a total of 7.1 GJ, which is approximately one-third the annual requirement for domestic hot water heating. At the present time domestic use of solar energy to heat water does not appear to be economically viable. High capital costs are the main problem. As a solar system with present day technology can only be expected to meet half to two-thirds of the hot water energy demand the savings are not sufficient for the system to pay for itself within a few years. 5 figs.

  1. Hot and cold pressing of (La,Ce)PO4-based nuclear waste forms

    International Nuclear Information System (INIS)

    Floran, R.J.; Rappaz, M.; Abraham, M.M.; Boatner, L.A.

    1981-01-01

    Synthetic analogs of the mineral monazite [(Ce,La,Ca,Th,U)(P,Si)O 4 ] are promising host phases for the isolation of actinide wastes. In the present investigation, the optimal conditions necessary to form high-density, simulated waste pellets from calcined LaPO 4 and CePO 4 powders have been examined. Pellets that are close to the theoretical density are necessary in order to minimize porosity and hence potential avenues along which fluid/waste interactions can take place. Calcined powders prepared by a urea precipitation process were cold pressed and hot pressed under a range of controlled conditions to form coherent, cylindrical pellets. Changes in density were examined as a function of pressure, temperature and duration of sintering. For cold-pressed pellets, a significant increase in density occurs during sintering between 1000 0 C and 1100 0 C. This increase is correlated with substantial grain coarsening of the pellet microstructure. A comparison of cold and hot pressing techniques suggests that, only after sintering, does the density of cold-pressed pellets approach (but not equal) that of the hot-pressed pellets. Densities >90% of the theoretical value of 5.11 g/cm 3 are easily attainable by hot pressing without sintering. The significance of density differences on pellet stability will be investigated in future leaching studies. The apparent advantages of the higher densities achieved by hot pressing must be weighed against the increased technological/engineering complexities involved when working at sustained high temperatures in a remote environment. Thus the cold pressing technique may ultimately prove more practical for large-scale commercial operations

  2. 3-D inelastic analysis methods for hot section components. Volume 2: Advanced special functions models

    Science.gov (United States)

    Wilson, R. B.; Banerjee, P. K.

    1987-01-01

    This Annual Status Report presents the results of work performed during the third year of the 3-D Inelastic Analysis Methods for Hot Sections Components program (NASA Contract NAS3-23697). The objective of the program is to produce a series of computer codes that permit more accurate and efficient three-dimensional analyses of selected hot section components, i.e., combustor liners, turbine blades, and turbine vanes. The computer codes embody a progression of mathematical models and are streamlined to take advantage of geometrical features, loading conditions, and forms of material response that distinguish each group of selected components.

  3. Mobile Launch Platform Vehicle Assembly Building Area (SWMU 056) Hot Spot 3 Bioremediation Interim Measures Work Plan, Kennedy Space Center, Florida

    Science.gov (United States)

    Whitney L. Morrison; Daprato, Rebecca C.

    2016-01-01

    This Interim Measures Work Plan (IMWP) presents an approach and design for the remediation of chlorinated volatile organic compound (CVOC) groundwater impacts using bioremediation (biostimulation and bioaugmentation) in Hot Spot 3, which is defined by the area where CVOC (trichloroethene [TCE], cis-1,2-dichloroethene [cDCE], and vinyl chloride [VC]) concentrations are greater than 10 times their respective Florida Department of Environmental Protection (FDEP) Natural Attenuation Default Concentration (NADC) [10xNADC] near the western Mobile Launch Platform (MLP) structure. The IM treatment area is the Hot Spot 3 area, which is approximately 0.07 acres and extends from approximately 6 to 22 and 41 to 55 feet below land surface (ft BLS). Within Hot Spot 3, a source zone (SZ; area with TCE concentrations greater than 1% solubility [11,000 micrograms per liter (micrograms/L)]) was delineated and is approximately 0.02 acres and extends from approximately 6 to 16 and 41 to 50 ft BLS.

  4. Impact Factors Analysis of the Hot Side Temperature of Thermoelectric Module

    Science.gov (United States)

    Zhang, Xingyu; Tan, Gangfeng; Yang, Bo

    2018-03-01

    The thermoelectric generator (TEG) plays a crucial role in converting the waste energy of exhaust into electricity, which ensures energy saving and increased fuel utilization efficiency. In the urban driving cycle, frequent vehicle operation, like deceleration or acceleration, results in continuous variation of the exhaust temperature. In order to make the operating performance stable, and to weaken the adverse effects of the frequent variation of the exhaust temperature on the lifetime and work efficiency of the electronic components of TEG systems, the output voltage of the thermoelectric (TE) module should stay more stable. This article provides an improved method for the temperature stability of the TE material hot side based on sandwiching material. From the view of the TEG system's average output power and the hot side temperature stability of the TE material, the analyzing factors, including the fluctuation frequency of the exhaust temperature and the physical properties and thickness of the sandwiching material are evaluated, respectively, in the sine and new European driving cycle (NEDC) fluctuation condition of the exhaust temperature. The results show few effects of sandwiching material thickness with excellent thermal conductivity on the average output power. During the 150-170 s of the NEDC test condition, the minimum hot side temperatures with a BeO ceramic thickness of 2 mm and 6 mm are, respectively, 537.19 K and 685.70 K, which shows the obvious effect on the hot side temperature stability of the BeO ceramic thickness in the process of acceleration and deceleration of vehicle driving.

  5. Individual features, working conditions and work injuries are associated with work ability among nursing professionals.

    Science.gov (United States)

    Fischer, Frida Marina; Martinez, Maria Carmen

    2013-01-01

    To investigate factors associated with work ability among nursing professionals. They comprised 514 nursing professionals (83.8% of the total number of workers) from a hospital in São Paulo, Brazil. In 2009, we conducted a cross-sectional study that was a part of a 5-year planned cohort study initiated in 2008. We administered a comprehensive questionnaire to the participants in order to obtain data on their sociodemographic characteristics, lifestyles, and working conditions. The questionnaire also contained the Brazilian versions of the following: the Job Stress Scale (JSS), Effort-Reward Imbalance (ERI) Questionnaire, Work-Related Activities That May Contribute To Job-Related Pain and/or Injury (WRAPI), and Work Ability Index (WAI). The results were analyzed using descriptive, bivariate, and multivariate linear regression analyses. On the WAI, 74.9% of the workers obtained a score of over 40 points (score range 7-49); the mean score was 42.3 points (SD=4.5). The final multivariate model showed that lower WAI scores were related to the work-related outcome, which was work injury, and the following individual characteristics and working conditions: body mass index (p=0.001), sex (female; p=0.002), sedentariness (p work (p=0.003), effort-reward ratio (p=0.001), violence at work (p=0.005), WRAPI score (p work injuries (yes; p=0.001). Various factors were associated with work ability. The results showed that a number of variables should be considered when planning and implementing actions to maintain or improve work ability among nursing professionals.

  6. Solar 'hot spots' are still hot

    Science.gov (United States)

    Bai, Taeil

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

  7. Overview of Dutch working conditions 2016: summary

    NARCIS (Netherlands)

    Douwes, M.; Genabeek, J.; Bossche, S. van den

    2017-01-01

    In 2016 there is an increase in compliance with the key provisions of the Working Conditions Act by companies, such as having a contract with an occupational health and safety service or service provider, sickness absence-related policies, a prevention employee, work meetings with employees and

  8. Application of Cyclone to Removal of Hot Particulate in Hot Cell

    International Nuclear Information System (INIS)

    Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin

    2005-01-01

    The size and main ingredient of hot particulate generated during the nuclide experiment in hot cells of nuclear facilities were 0.5300 μm and UO 2 . A cyclone filter equipment which consists of a cyclone and Bag/HEPA filter was devised to remove hot particulate generated during the nuclide experiment in hot cells of nuclear facilities. The experimental conditions to maximize the collection efficiency of hot particulate were suggested through experiments done with the cyclone filter equipment. With the large size of simulated particulate, the collection efficiency of the particulate was high. When the size of simulated particulate was more than 5 μm, the collection efficiency of the particulate was more than 80% and when the size of simulated particulate was less than 1.0 μm, the collection efficiency decreased by less than. If the inflow velocity of simulated particulate was increased, the collection efficiency of the particulate was also increased. When the inflow velocity of simulated particulate was more than 12 m/sec, the collection efficiency was higher than , but after 17 m/sec inflow velocity, no change observed. The collection efficiency of the simulated particulate can be enhanced with the length of vortex finder inside the chamber. With the length of vortex finder, 7.2 cm, the observed collection efficiency of the particulate was the maximum. Moreover, when the sub-cone was attached under the cyclone, the collection efficiency of cyclone increased 2%. It was found that effect by attachment of sub-cone was not serious.

  9. Monitoring psychosocial stress at work: development of the Psychosocial Working Conditions Questionnaire.

    Science.gov (United States)

    Widerszal-Bazyl, M; Cieślak, R

    2000-01-01

    Many studies on the impact of psychosocial working conditions on health prove that psychosocial stress at work is an important risk factor endangering workers' health. Thus it should be constantly monitored like other work hazards. The paper presents a newly developed instrument for stress monitoring called the Psychosocial Working Conditions Questionnaire (PWC). Its structure is based on Robert Karasek's model of job stress (Karasek, 1979; Karasek & Theorell, 1990). It consists of 3 main scales Job Demands, Job Control, Social Support and 2 additional scales adapted from the Occupational Stress Questionnaire (Elo, Leppanen, Lindstrom, & Ropponen, 1992), Well-Being and Desired Changes. The study of 8 occupational groups (bank and insurance specialists, middle medical personnel, construction workers, shop assistants, government and self-government administration officers, computer scientists, public transport drivers, teachers, N = 3,669) indicates that PWC has satisfactory psychometrics parameters. Norms for the 8 groups were developed.

  10. Solar hot spots are still hot

    International Nuclear Information System (INIS)

    Bai, T.

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22. 14 refs

  11. Hot working behavior of selective laser melted and laser metal deposited Inconel 718

    Science.gov (United States)

    Bambach, Markus; Sizova, Irina

    2018-05-01

    The production of Nickel-based high-temperature components is of great importance for the transport and energy sector. Forging of high-temperature alloys often requires expensive dies, multiple forming steps and leads to forged parts with tolerances that require machining to create the final shape and a large amount of scrap. Additive manufacturing offers the possibility to print the desired shapes directly as net-shape components, requiring only little additional effort in machining. Especially for high-temperature alloys carrying a large amount of energy per unit mass, additive manufacturing could be more energy-efficient than forging if the energy contained in the machining scrap exceeds the energy needed for powder production and laser processing. However, the microstructure and performance of 3d-printed parts will not reach the level of forged material unless further expensive processes such as hot-isostatic pressing are used. Using the design freedom and possibilities to locally engineer material, additive manufacturing could be combined with forging operations to novel process chains, offering the possibility to reduce the number of forging steps and to create near-net shape forgings with desired local properties. Some innovative process chains combining additive manufacturing and forging have been patented recently, but almost no scientific knowledge on the workability of 3D printed preforms exists. The present study investigates the flow stress and microstructure evolution during hot working of pre-forms produced by laser powder deposition and selective laser melting (Figure 1) and puts forward a model for the flow stress.

  12. PWR hot leg natural circulation modeling with MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1998-12-31

    Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

  13. PWR hot leg natural circulation modeling with MELCOR code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Hong; Lee, Jong In [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1997-12-31

    Previous MELCOR and SCDAP/RELAP5 nodalizations for simulating the counter-current, natural circulation behavior of vapor flow within the RCS hot legs and SG U-tubes when core damage progress can not be applied to the steady state and water-filled conditions during the initial period of accident progression because of the artificially high loss coefficients in the hot legs and SG U-tubes which were chosen from results of COMMIX calculation and the Westinghouse natural circulation experiments in a 1/7-scale facility for simulating steam natural circulation behavior in the vessel and circulation modeling which can be used both for the liquid flow condition at steady state and for the vapor flow condition at the later period of in-vessel core damage. For this, the drag forces resulting from the momentum exchange effects between the two vapor streams in the hot leg was modeled as a pressure drop by pump model. This hot leg natural circulation modeling of MELCOR was able to reproduce similar mass flow rates with those predicted by previous models. 6 refs., 2 figs. (Author)

  14. Physicians' Psychosocial Work Conditions and Quality of Care: A Literature Review

    Directory of Open Access Journals (Sweden)

    Peter Angerer

    2015-05-01

    Full Text Available Background: Physician jobs are associated with adverse psychosocial work conditions. We summarize research on the relationship of physicians' psychosocial work conditions and quality of care. Method: A systematic literature search was conducted in MEDLINE and PsycINFO. All studies were classified into three categories of care quality outcomes: Associations between physicians' psychosocial work conditions and (1 the physician-patient-relationship, or (2 the care process and outcomes, or (3 medical errors were examined. Results: 12 publications met the inclusion criteria. Most studies relied on observational cross-sectional and controlled intervention designs. All studies provide at least partial support for physicians’ psychosocial work conditions being related to quality of care. Conclusions: This review found preliminary evidence that detrimental physicians’ psychosocial work conditions adversely influence patient care quality. Future research needs to apply strong designs to disentangle the indirect and direct effects of adverse psychosocial work conditions on physicians as well as on quality of care.Keywords: psychosocial work conditions, physicians, quality of care, physician-patient-relationship, hospital, errors, review, work stress, clinicians

  15. Modeling patterns of hot water use in households

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, J.D.; Liu, Xiaomin; McMahon, J.E. [and others

    1996-11-01

    This report presents a detailed model of hot water use patterns in individual household. The model improves upon an existing model by including the effects of four conditions that were previously unaccounted for: the absence of a clothes washer; the absence of a dishwasher; a household consisting of seniors only; and a household that does not pay for its own hot water use. Although these four conditions can significantly affect residential hot water use, and have been noted in other studies, this is the first time that they have been incorporated into a detailed model. This model allows detailed evaluation of the impact of potential efficiency standards for water heaters and other market transformation policies. 21 refs., 3 figs., 10 tabs.

  16. Long Working Hours in Korea: Based on the 2014 Korean Working Conditions Survey.

    Science.gov (United States)

    Park, Jungsun; Kim, Yangho; Han, Boyoung

    2017-12-01

    Long working hours adversely affect worker safety and health. In 2004, Korea passed legislation that limited the work week to 40 hours, in an effort to improve quality-of-life and increase business competitiveness. This regulation was implemented in stages, first for large businesses and then for small businesses, from 2004 to 2011. We previously reported that average weekly working hours decreased from 2006 to 2010, based on the Korean Working Conditions Survey. In the present study, we examine whether average weekly working hours continued to decrease in 2014 based on the 2014 Korean Working Conditions Survey. The results show that average weekly working hours among all groups of workers decreased in 2014 relative to previous years; however, self-employed individuals and employers (who are not covered by the new legislation) in the specific service sectors worked > 60 h/wk in 2014. The Korean government should prohibit employees from working excessive hours and should also attempt to achieve social and public consensus regarding work time reduction to improve the safety, health, and quality-of-life of all citizens, including those who are employers and self-employed.

  17. Improving growth performance in calves under hot weather conditions

    International Nuclear Information System (INIS)

    Emara, S.S.M.

    2009-01-01

    The main objectives of the present study were to evaluate the effect of some supplement such as dried live yeast DLY (Saccharomyces cerevisiae), DLY + vitamin E and / or dried whey milk (DWM) on blood constituents and thyroid activity in relation to some immune indices and growth performance of calves under hot weather conditions. The ambient temperature and relative humidity averaged 36.9±4 degree C and 43-58 % during day and 29±4 degree C and 60-68 % during night, respectively, which were equivalent to temperature humidity index of 86-89 during day and 78-80 during night . The present study included three experiments as follows. Experiment 1 : Six female bovine Baladi calves of 8-10 months old and 100 kg initial body weight (IBW) were used during two periods. In the first period, the calves were offered the basal diet for one month and considered as a control period. In the second period, the same calves were fed the same basal diet which supplemented with 15 g / calf/ day DLY for one month and considered as treated period. The obtained results indicated that supplementation of DLY reduced significantly the respiration rate (RR) and rectal temperature (RT) as well as serum lipids profile including total cholesterol, low density lipoprotein (LDL- cholesterol) very low density lipoprotein (VLDL-cholesterol) triglycerides and phospholipids.The second and third experiments were carried out for improving growth performance of heat-stressed bovine baladi calves by adding DLY and vitamine E (alpha-tocopherol) to their diet in experiment 2 and dried whey milk (DWM) in experiment 3.

  18. HOT 2015

    DEFF Research Database (Denmark)

    Hannibal, Sara Stefansen

    2016-01-01

    HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud.......HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud....

  19. Hot cell works and related irradiation tests in fission reactor for development of new materials for nuclear application

    International Nuclear Information System (INIS)

    Shikama, Tatsuo

    1999-01-01

    Present status of research works in Oarai Branch, Institute for Materials Research, Tohoku University, utilizing Japan Materials Testing Reactor and related hot cells will be described.Topics are mainly related with nuclear materials studies, excluding fissile materials, which is mainly aiming for development of materials for advanced nuclear systems such as a nuclear fusion reactor. Conflict between traditional and routined procedures and new demands will be described and future perspective is discussed. (author)

  20. Psychosocial working conditions and diabetes self-management at work: A qualitative study.

    Science.gov (United States)

    Loerbroks, Adrian; Nguyen, Xuan Quynh; Vu-Eickmann, Patricia; Krichbaum, Michael; Kulzer, Bernhard; Icks, Andrea; Angerer, Peter

    2018-03-31

    We conducted a qualitative study to expand our current understanding of the potential link between psychosocial working conditions and diabetes self-management at work. Thirty employed adults with diabetes mellitus living in Germany (n = 19 with type 1, n = 11 with type 2, 57% female, aged 24-64 years) were recruited. Using a topic guide, we carried out in-depth interviews in face-to-face contact or by telephone. Interviews were transcribed and content-analyzed using MaxQDA. Psychosocial working conditions perceived to detrimentally affect self-management activities included, amongst others, a high workload, poor job control, unhygienic working environments, the requirement to work under high or fluctuating temperature, perceived social norms at the workplace, and the attitude to prioritize work-related demands as opposed to diabetes-related demands. The types of self-management activities considered to be adversely affected related to glucose monitoring, insulin injections, dietary control, the ability to recognize hypoglycemia and health care use. Various types of occupational psychosocial factors may determine diabetes self-management practices at the workplace. Quantitative studies are needed to confirm our observations. Subsequently, interventions could be developed and evaluated to improve opportunities to adequately engage into diabetes self-management at work. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Heat transfer and pressure drop of a gasket-sealed plate heat exchanger depending on operating conditions across hot and cold sides

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Joon [Kookmin University, Seoul (Korea, Republic of); Kim, Hyouck Ju [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2016-05-15

    In a gas engine based cogeneration system, heat may be recovered from two parts: Jacket water and exhaust gas. The heat from the jacket water is often recovered using a plate-type heat exchanger, and is used for room heating and/or hot water supply applications. Depending on the operating conditions of an engine and heat recovery system, there may be an imbalance in the flow rate and supply pressure between the engine side and the heat-recovery side of the heat exchanger. This imbalance causes deformation of the plate, which affects heat transfer and pressure drop characteristics. In the present study, the heat transfer and pressure drop inside a heat exchanger were investigated under varying hot-side and cold-side operating conditions. Thermal efficiency of the plate heat exchanger decreases up to 30% with an operating engine load of 50%. A correction factor for the pressure drop correlation is proposed to account for the deformation caused by an imbalance between the two sides of a heat exchanger.

  2. Hot pressing of B4C/SiC composites

    International Nuclear Information System (INIS)

    Sahin, F.C.; Turhan, E.; Yesilcubuk, S.A.; Addemir, O.

    2005-01-01

    B 4 C/SiC ceramic composites containing 10-20-30 vol % SiC were prepared by hot pressing method. The effect of SiC addition and hot pressing temperature on sintering behaviour and mechanical properties of hot pressed composites were investigated. Microstructures of hot pressed samples were examined by SEM technique. Three different temperatures (2100 deg. C, 2200 deg. C and 2250 deg. C) were used to optimize hot pressing temperature applying 100 MPa pressure under argon atmosphere during the sintering procedure. The highest relative density of 98.44 % was obtained by hot pressing at 2250 deg. C. However, bending strengths of B 4 C/SiC composite samples were lower than monolithic B 4 C in all experimental conditions. (authors)

  3. Passivity and passivity breakdown of 304L stainless steel in hot and concentrated nitric acid

    International Nuclear Information System (INIS)

    Gillard-Tcharkhtchi, Elsa

    2014-01-01

    The objective of this study is to characterize the oxidation behavior of 304L stainless steel (SS) in representative conditions of spent nuclear fuel reprocessing, i.e. in hot and concentrated nitric acid. In these conditions the SS electrochemical potential is in the passive domain and its corrosion rate is low. However when the media becomes more aggressive, the potential may be shifted towards the trans-passive domain characterized with a high corrosion rate. Passivity and passivity breakdown in the trans-passive domain are of a major interest for the industry. So as to characterize these phenomenons, this work was undertaken with the following representative conditions: a 304L SS from an industrial sheet was studied, the media was hot and concentrated HNO 3 , long term tests were performed. First, the surface of an immersed 304L SS was characterized with several complementary techniques from the micro to the nanometer scale. Then oxidation kinetics was studied in the passive and in the trans-passive domain. The oxidation behavior was studied thanks to weight loss determination and surface analysis. Finally, oxidation evolution as a function of the potential was studied from the passive to the trans-passive domain. In particular, this allowed us to obtain the anodic curve of 304L SS in hot and concentrated and to define precisely the 304L SS limits of in such conditions. (author) [fr

  4. Human thermal comfort conditions and urban planning in hot-humid climates-The case of Cuba.

    Science.gov (United States)

    Rodríguez Algeciras, José Abel; Coch, Helena; De la Paz Pérez, Guillermo; Chaos Yeras, Mabel; Matzarakis, Andreas

    2016-08-01

    Climate regional characteristics, urban environmental conditions, and outdoors thermal comfort requirements of residents are important for urban planning. Basic studies of urban microclimate can provide information and useful resources to predict and improve thermal conditions in hot-humid climatic regions. The paper analyzes the thermal bioclimate and its influence as urban design factor in Cuba, using Physiologically Equivalent Temperature (PET). Simulations of wind speed variations and shade conditions were performed to quantify changes in thermal bioclimate due to possible modifications in urban morphology. Climate data from Havana, Camagüey, and Santiago of Cuba for the period 2001 to 2012 were used to calculate PET with the RayMan model. The results show that changes in meteorological parameters influence the urban microclimate, and consequently modify the thermal conditions in outdoors spaces. Shade is the predominant strategy to improve urban microclimate with more significant benefits in terms of PET higher than 30 °C. For climatic regions such as the analyzed ones, human thermal comfort can be improved by a wind speed modification for thresholds of PET above 30 °C, and by a wind speed decreases in conditions below 26 °C. The improvement of human thermal conditions is crucial for urban sustainability. On this regards, our study is a contribution for urban designers, due to the possibility of taking advantage of results for improving microclimatic conditions based on urban forms. The results may enable urban planners to create spaces that people prefer to visit, and also are usable in the reconfiguration of cities.

  5. Physiological and biochemical response to Omega-3 plus as a dietary supplement to growing goats under hot summer conditions

    Directory of Open Access Journals (Sweden)

    Fatma Edrees Ibrahim Teama

    2016-04-01

    Full Text Available ABSTRACT The objective of the present study was to assess the effect of dietary supplementation of Omega-3 plus on some the physiological and biochemical traits in growing Baladi goats under hot summer conditions. Thirty-four growing male goats (4-5 months old were randomly divided into two equal groups. Animals in group 1 were fed a concentrate feed mixture (CFM, which was the control group. Goats in group 2 (the experimental group were offered Omega-3 plus (1,000 mg/animal day-1 (30% fish oil, containing 18% eicosapentaenoic acid and 12% docosahexaenoic acid + 100 mg wheat germ oil (0.22% tocopherols daily in addition to the basal diet for four months (the experimental period during the hot summer season. Body weight (BW changes of both groups were recorded monthly during the experiment. Blood samples were collected monthly, and total protein, immunoglobulin G (IgG, total cholesterol, triglycerides, liver enzymes (AST and ALT, blood urea nitrogen, serum creatinine, and thyroid hormones (T3 and T4 were estimated. A significant increase in the live BW of growing goats was recorded as a result of dietary supplementation of Omega-3 plus. Total protein, IgG, and T3 levels were higher than those obtained with control. In contrast, total cholesterol, triglycerides, urea, ALT, and AST levels were significantly reduced. The serum concentration of creatinine and T4 levels was indistinguishable from those of control. Addition of Omega-3 plus as a dietary supplement to growing goats under hot summer conditions increases their daily weight gain and improves their general physiological and biochemical status by decreasing total cholesterol, triglycerides, urea, ALT, and AST. It is thus suggested that Omega-3 plus should be used as a supplement in the growth period of goats.

  6. The influence of delta ferrite in the AISI 416 stainless steel hot workability

    International Nuclear Information System (INIS)

    Cardoso, P.H.S.; Kwietniewski, C.; Porto, J.P.; Reguly, A.; Strohaecker, T.R.

    2003-01-01

    Delta ferrite in martensitic stainless steels may have an adverse effect on the mechanical properties of these materials at high temperature. The occurrence of such phase is determined by the material chemical composition (mainly Cr and C), as-received microstructure condition and hot working temperature. The aim of this investigation is to assess the influence of delta ferrite on the hot workability of the martensitic AISI 416 stainless steel. Hence, different heats of this material (differing in chemical composition and as-received microstructure) were submitted to heating tests in order to observe the microstructural transformations that take place at high temperature and then examine the influence of these transformations on the mechanical behaviour. Phase characterisation and quantification were carried out using scanning electron microscopy/energy-dispersive X-ray microanalysis and image analysis. The heating tests were performed in the temperature range of 1100-1350 deg. C and hot workability in two heats with different delta ferrite content was assessed by hot torsion tests in the temperature range of 1000-1250 deg. C. The results have indicated that chemical composition and as-received microstructure strongly affect delta ferrite formation, which in turn deteriorates hot workability of the martensitic AISI 416 stainless steel

  7. Perception of orchestral musicians about work environment and conditions

    OpenAIRE

    Clarissa Stefani Teixeira; Fausto Kothe; Luis Felipe Dias Lopes; Érico Felden Pereira

    2014-01-01

    The objective of this study was to investigate the perception of 11 orchestral string (viola and violin) musicians of both genders with respect to their work environment and conditions. We applied a questionnaire with demographic information and the scale Profile of Work Environment and Working Conditions by Nahas et al. (2009), which analyzes the following components: physical environment, social environment, development and professional achievement, salary and benefits, and social relev...

  8. Hot atom chemistry of carbon

    International Nuclear Information System (INIS)

    Wolf, A.P.

    1975-01-01

    The chemistry of energetic carbon atoms is discussed. The experimental approach to studies that have been carried out is described and the mechanistic framework of hot carbon atom reactions is considered in some detail. Finally, the direction that future work might take is examined, including the relationship of experimental to theoretical work. (author)

  9. The effect of hot deformation on the bainite transformation of a working tool steel; Efeito da deformacao a quente sobre a transformacao bainitica de um aco ferramenta

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca Lima, Ricardo F. de; Carvalho, Miguel A.; Nogueira, Marcos A.S. [Acos Villares SA, Rio de Janeiro, RJ (Brazil)

    1989-12-31

    The effect of hot deformation of austenite on its isothermal transformation at 400 degrees Celsius for a hot working steel has been investigated. The degrees of transformation was varied and the results were analysed by optical metallography. Increasing the deformation, the bainite nucleation occurs in twins and grain boundaries, and also inside the austenitic grains. (author). 10 refs., 8 figs.

  10. Menopausal Hot Flashes and White Matter Hyperintensities

    Science.gov (United States)

    Thurston, Rebecca C.; Aizenstein, Howard J.; Derby, Carol A.; Sejdić, Ervin; Maki, Pauline M.

    2015-01-01

    Objective Hot flashes are the classic menopausal symptom. Emerging data links hot flashes to cardiovascular disease (CVD) risk, yet how hot flashes are related to brain health is poorly understood. We examined the relationship between hot flashes - measured via physiologic monitor and self-report - and white matter hyperintensities (WMH) among midlife women. Methods Twenty midlife women ages 40-60 without clinical CVD, with their uterus and both ovaries, and not taking hormone therapy were recruited. Women underwent 24 hours of ambulatory physiologic and diary hot flash monitoring to quantify hot flashes; magnetic resonance imaging to assess WMH burden; 72 hours of actigraphy and questionnaires to quantify sleep; and a blood draw, questionnaires, and physical measures to quantify demographics and CVD risk factors. Test of a priori hypotheses regarding relations between physiologically-monitored and self-reported wake and sleep hot flashes and WMH were conducted in linear regression models. Results More physiologically-monitored hot flashes during sleep were associated with greater WMH, controlling for age, race, and body mass index [beta(standard error)=.0002 (.0001), p=.03]. Findings persisted controlling for sleep characteristics and additional CVD risk factors. No relations were observed for self-reported hot flashes. Conclusions More physiologically-monitored hot flashes during sleep were associated with greater WMH burden among midlife women free of clinical CVD. Results suggest that relations between hot flashes and CVD risk observed in the periphery may extend to the brain. Future work should consider the unique role of sleep hot flashes in brain health. PMID:26057822

  11. Long Working Hours in Korea: Based on the 2014 Korean Working Conditions Survey

    Directory of Open Access Journals (Sweden)

    Jungsun Park

    2017-12-01

    Full Text Available Background: Long working hours adversely affect worker safety and health. In 2004, Korea passed legislation that limited the work week to 40 hours, in an effort to improve quality-of-life and increase business competitiveness. This regulation was implemented in stages, first for large businesses and then for small businesses, from 2004 to 2011. We previously reported that average weekly working hours decreased from 2006 to 2010, based on the Korean Working Conditions Survey. Methods: In the present study, we examine whether average weekly working hours continued to decrease in 2014 based on the 2014 Korean Working Conditions Survey. Results: The results show that average weekly working hours among all groups of workers decreased in 2014 relative to previous years; however, self-employed individuals and employers (who are not covered by the new legislation in the specific service sectors worked > 60 h/wk in 2014. Conclusion: The Korean government should prohibit employees from working excessive hours and should also attempt to achieve social and public consensus regarding work time reduction to improve the safety, health, and quality-of-life of all citizens, including those who are employers and self-employed. Keywords: employee, employer, Korea, self-employed, working hours

  12. Hot-dry-rock geothermal resource 1980

    Energy Technology Data Exchange (ETDEWEB)

    Heiken, G.; Goff, F.; Cremer, G. (ed.)

    1982-04-01

    The work performed on hot dry rock (HDR) geothermal resource evaluation, site characterization, and geophysical exploration techniques is summarized. The work was done by region (Far West, Pacific Northwest, Southwest, Rocky Mountain States, Midcontinent, and Eastern) and limited to the conterminous US.

  13. Mexican-origin parents' work conditions and adolescents' adjustment.

    Science.gov (United States)

    Wheeler, Lorey A; Updegraff, Kimberly A; Crouter, Ann

    2015-06-01

    Mexican-origin parents' work experiences are a distal extrafamilial context for adolescents' adjustment. This 2-wave multiinformant study examined the prospective mechanisms linking parents' work conditions (i.e., self-direction, work pressure, workplace discrimination) to adolescents' adjustment (i.e., educational expectations, depressive symptoms, risky behavior) across the transition to high school drawing on work socialization and spillover models. We examined the indirect effects of parental work conditions on adolescent adjustment through parents' psychological functioning (i.e., depressive symptoms, role overload) and aspects of the parent-adolescent relationship (i.e., parental solicitation, parent-adolescent conflict), as well as moderation by adolescent gender. Participants were 246 predominantly immigrant, Mexican-origin, 2-parent families who participated in home interviews when adolescents were approximately 13 and 15 years of age. Results supported the positive impact of fathers' occupational self-direction on all 3 aspects of adolescents' adjustment through decreased father-adolescent conflict, after controlling for family socioeconomic status and earner status, and underemployment. Parental work pressure and discrimination were indirectly linked to adolescents' adjustment, with different mechanisms emerging for mothers and fathers. Adolescents' gender moderated the associations between fathers' self-direction and girls' depressive symptoms, and fathers' experiences of discrimination and boys' risk behavior. Results suggest that Mexican-origin mothers' and fathers' perceptions of work conditions have important implications for multiple domains of adolescents' adjustment across the transition to high school. (c) 2015 APA, all rights reserved).

  14. Analýza teplotního profilu hot bed a hot end u 3D tiskárny pomocí CAE

    OpenAIRE

    Severa, Tomáš

    2014-01-01

    Předkládaná diplomová práce se zabývá 3D tiskem na nekomerčních 3D tiskárnách typu RepRap a materiály, které se používají při tisku. Výstupem této práce je stručný úvod do problematiky 3D tisku, teorie šíření tepla a rozbor dvou nejdůležitějších částí tiskárny hot bed a hot end. K analýze a optimalizaci teplotního profilu hot bed a hot end jsou použity systémy pro podporu inženýrských prací CAD a CAE, SolidWorks a SolidWorks Flow Simulation. This master‘s thesis deals with 3D printing for ...

  15. HotRegion: a database of predicted hot spot clusters.

    Science.gov (United States)

    Cukuroglu, Engin; Gursoy, Attila; Keskin, Ozlem

    2012-01-01

    Hot spots are energetically important residues at protein interfaces and they are not randomly distributed across the interface but rather clustered. These clustered hot spots form hot regions. Hot regions are important for the stability of protein complexes, as well as providing specificity to binding sites. We propose a database called HotRegion, which provides the hot region information of the interfaces by using predicted hot spot residues, and structural properties of these interface residues such as pair potentials of interface residues, accessible surface area (ASA) and relative ASA values of interface residues of both monomer and complex forms of proteins. Also, the 3D visualization of the interface and interactions among hot spot residues are provided. HotRegion is accessible at http://prism.ccbb.ku.edu.tr/hotregion.

  16. Air system in the hot cell for injectable radiopharmaceutical production: requirements for personnel and environment safety and protection of the product

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Fabio E.; Araujo, Elaine B., E-mail: fecampos@ipen.b, E-mail: ebaraujo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Radiopharmaceuticals are applied in Nuclear Medicine in diagnostic and therapeutic procedures and must be manufactured in accordance with the basic principles of Good Manufacturing Practices (GMP) for sterile pharmaceutical products. In order to prevent the uncontrolled spread of radioactive contamination, the processing of radioactive materials requires an exhausted and shielded special enclosure called hot cell. The quality of air inside the hot cell must be controlled in order to prevent the contamination of the product with particulate material or microorganisms. On the other hand, the hot cell must prevent external contamination with radioactive material. The aim of this work is to discuss the special requirements for hot cells taking in account the national rules for injectable pharmaceutical products and international standards available. Ventilation of radiopharmaceutical production facilities should meet the requirement to prevent the contamination of products and the exposure of working personnel to radioactivity. Positive pressure areas should be used to process sterile products. In general, any radioactivity should handle within specifically designed areas maintained under negative pressures. The production of sterile radioactive products should therefore be carried out under negative pressure surrounded by a positive pressure zone ensuring that appropriate air quality requirements are met. Some of the recent developments in the use of radioisotopes in medical field have also significantly impacted on the evolution of handling facilities. Application of pharmaceutical GMP requirements for air quality and processing conditions in the handling facilities of radioactive pharmaceuticals has led to significant improvements in the construction of isolator-like hot cells and clean rooms with HEPA filtered ventilation and air conditioning (HVAC) systems. Clean grade A (class 100) air quality hot cells are now available commercially, but in a high cost

  17. Air system in the hot cell for injectable radiopharmaceutical production: requirements for personnel and environment safety and protection of the product

    International Nuclear Information System (INIS)

    Campos, Fabio E.; Araujo, Elaine B.

    2009-01-01

    Radiopharmaceuticals are applied in Nuclear Medicine in diagnostic and therapeutic procedures and must be manufactured in accordance with the basic principles of Good Manufacturing Practices (GMP) for sterile pharmaceutical products. In order to prevent the uncontrolled spread of radioactive contamination, the processing of radioactive materials requires an exhausted and shielded special enclosure called hot cell. The quality of air inside the hot cell must be controlled in order to prevent the contamination of the product with particulate material or microorganisms. On the other hand, the hot cell must prevent external contamination with radioactive material. The aim of this work is to discuss the special requirements for hot cells taking in account the national rules for injectable pharmaceutical products and international standards available. Ventilation of radiopharmaceutical production facilities should meet the requirement to prevent the contamination of products and the exposure of working personnel to radioactivity. Positive pressure areas should be used to process sterile products. In general, any radioactivity should handle within specifically designed areas maintained under negative pressures. The production of sterile radioactive products should therefore be carried out under negative pressure surrounded by a positive pressure zone ensuring that appropriate air quality requirements are met. Some of the recent developments in the use of radioisotopes in medical field have also significantly impacted on the evolution of handling facilities. Application of pharmaceutical GMP requirements for air quality and processing conditions in the handling facilities of radioactive pharmaceuticals has led to significant improvements in the construction of isolator-like hot cells and clean rooms with HEPA filtered ventilation and air conditioning (HVAC) systems. Clean grade A (class 100) air quality hot cells are now available commercially, but in a high cost

  18. Effects of LaB{sub 6} additions on the microstructure and mechanical properties of a sintered and hot worked P/M Ti alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lou, Jia; Gabbitas, Brian, E-mail: briang@waikato.ac.nz; Yang, Fei; Raynova, Stella; Lu, Huiyang

    2016-07-25

    A trace amount of LaB{sub 6} powder was added to P/M Ti and Ti–6Al–4V alloy to improve mechanical properties and refine the microstructure. After sintering, TiB whiskers and La{sub 2}O{sub 3} dispersoids had formed in the microstructure. In a CP Ti alloy, the generation of secondary phases leads to a much refined microstructure, but the alignment of TiB whiskers led to a variation in mechanical properties. Open die forging (ODF) or powder compact extrusion (PCE) was carried out on sintered Ti–6Al–4V alloy to further improve the mechanical properties. This caused severe deformation and re-alignment of the TiB whiskers. Comparing the properties of hot worked Ti–6Al–4V alloy and Ti–6Al–4V alloy with boron additions, an addition of LaB{sub 6} leads to slightly lower strength but gives significant better ductility. - Highlights: • LaB{sub 6} powder was added to sintered and hot worked Ti and Ti–6Al–4V alloy. • TiB whiskers and La{sub 2}O{sub 3} dispersoids formed in the microstructure. • Different alignments of TiB{sub w} led to a variation in mechanical properties. • Hot working caused severe deformation and re-alignment of TiB{sub w}. • An addition of LaB{sub 6} is better than pure boron additions.

  19. Open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water

    International Nuclear Information System (INIS)

    Hou Shaobo; Li Huacong; Zhang Hefei

    2007-01-01

    This paper presents an open air-vapor compression refrigeration system for air conditioning and hot water cooled by cool water and proves its feasibility through performance simulation. Pinch technology is used in analysis of heat exchange in the surface heat exchanger, and the temperature difference at the pinch point is selected as 6 o C. Its refrigeration depends mainly on both air and vapor, more efficient than a conventional air cycle, and the use of turbo-machinery makes this possible. This system could use the cool in the cool water, which could not be used to cool air directly. Also, the heat rejected from this system could be used to heat cool water to 33-40 o C. The sensitivity analysis of COP to η c and η t and the simulated results T 4 , T 7 , T 8 , q 1 , q 2 and W m of the cycle are given. The simulations show that the COP of this system depends mainly on T 7 , η c and η t and varies with T 3 or T wet and that this cycle is feasible in some regions, although the COP is sensitive to the efficiencies of the axial compressor and turbine. The optimum pressure ratio in this system could be lower, and this results in a fewer number of stages of the axial compressor. Adjusting the rotation speed of the axial compressor can easily control the pressure ratio, mass flow rate and the refrigerating capacity. The adoption of this cycle will make the air conditioned room more comfortable and reduce the initial investment cost because of the obtained very low temperature air. Humid air is a perfect working fluid for central air conditioning and no cost to the user. The system is more efficient because of using cool water to cool the air before the turbine. In addition, pinch technology is a good method to analyze the wet air heat exchange with water

  20. A novel unified dislocation density-based model for hot deformation behavior of a nickel-based superalloy under dynamic recrystallization conditions

    International Nuclear Information System (INIS)

    Lin, Y.C.; Wen, Dong-Xu; Chen, Xiao-Min; Chen, Ming-Song

    2016-01-01

    In this study, a novel unified dislocation density-based model is presented for characterizing hot deformation behaviors in a nickel-based superalloy under dynamic recrystallization (DRX) conditions. In the Kocks-Mecking model, a new softening item is proposed to represent the impacts of DRX behavior on dislocation density evolution. The grain size evolution and DRX kinetics are incorporated into the developed model. Material parameters of the developed model are calibrated by a derivative-free method of MATLAB software. Comparisons between experimental and predicted results confirm that the developed unified dislocation density-based model can nicely reproduce hot deformation behavior, DRX kinetics, and grain size evolution in wide scope of initial grain size, strain rate, and deformation temperature. Moreover, the developed unified dislocation density-based model is well employed to analyze the time-variant forming processes of the studied superalloy. (orig.)

  1. A novel unified dislocation density-based model for hot deformation behavior of a nickel-based superalloy under dynamic recrystallization conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.C. [Central South University, School of Mechanical and Electrical Engineering, Changsha (China); Light Alloy Research Institute of Central South University, Changsha (China); State Key Laboratory of High Performance Complex Manufacturing, Changsha (China); Wen, Dong-Xu; Chen, Xiao-Min [Central South University, School of Mechanical and Electrical Engineering, Changsha (China); Chen, Ming-Song [Central South University, School of Mechanical and Electrical Engineering, Changsha (China); State Key Laboratory of High Performance Complex Manufacturing, Changsha (China)

    2016-09-15

    In this study, a novel unified dislocation density-based model is presented for characterizing hot deformation behaviors in a nickel-based superalloy under dynamic recrystallization (DRX) conditions. In the Kocks-Mecking model, a new softening item is proposed to represent the impacts of DRX behavior on dislocation density evolution. The grain size evolution and DRX kinetics are incorporated into the developed model. Material parameters of the developed model are calibrated by a derivative-free method of MATLAB software. Comparisons between experimental and predicted results confirm that the developed unified dislocation density-based model can nicely reproduce hot deformation behavior, DRX kinetics, and grain size evolution in wide scope of initial grain size, strain rate, and deformation temperature. Moreover, the developed unified dislocation density-based model is well employed to analyze the time-variant forming processes of the studied superalloy. (orig.)

  2. Progress report on research and development work 1991 of the Department of Hot Chemistry, Karlsruhe Nuclear Research Center

    International Nuclear Information System (INIS)

    1991-03-01

    In the year under review, the Institute of Hot Chemistry (IHCH) was in the midst of a thematic reorientation process. The priority of future chemical-technical work will be in the field of the development of supercriticality processes. The objective of such work consists in seeking new ways for getting rid of resistant chemical pollutants (halogenated organic compounds). The following projects are presented in detail: 1) Waste control in the environment (communal waste management; water and soil; emission-reducing processes; highly polluted soils); 2) Solid state and materials research (chemistry of materials research); basic physical research (neutrino and particle physics); 3) Nuclear waste management (concluding work on reprocessing technology), and 4) Other research projects (Institute-related research). The Annex lists the publications made by the IHCH staff. (BBR) [de

  3. Working Conditions of Agricultural Workers: A Reflection of Socio-economic Status

    Directory of Open Access Journals (Sweden)

    B.R.K. Sinha

    2010-11-01

    Full Text Available Working conditions of agricultural workers, like industrial, are one of the burning issues in a developing region. It is related to agricultural activities of the workers and their socio-economic status. Working conditions may be both favourable and unfavourable. Those working conditions which are unfavourable to health may be considered as occupational hazards or as a part of occupational environment. It is generally observed that a large section of the agricultural workers remains engaged in agricultural practices at the time of hunger, thirst, pregnancy (women and even despite their unpleasant state of health, both mental and physical. They also continue to work for more than the prescribed standard hours and also having half-fed. These are not positive or favourable working conditions to their health as they normally cause general weakness, fatigue, stomach disorder, dizziness, headache, loss of energy and some other similar physical, mental and psychological problems. The major driving forces behind as such adverse working conditions and its consequences are the pressure of work, pressure of land owners and of timely completion of works, shortage of manpower, psychological attitude, ignorance, weather constraints, poverty, illiteracy, lack of work related health awareness, lower social and economic status, etc. Such forces compel the workers to be engaged in their agricultural practices under the above circumstance. Adverse working conditions of agricultural workers vary widely with reference to space, time, activities, demographics, society, economy and consequently affect both the mental and physical, social and psychological conditions of the agricultural workers. Persons in varying number in the age groups from 15-34 and 35-49 to 60 & + year were reported working under different types of undesirable working conditions. The people from the S.C. and S.T. categories are the major sufferers as most of them continue their work during

  4. The impact of adjusted work conditions and disease-modifying drugs on work ability in multiple sclerosis.

    Science.gov (United States)

    Wickström, Anne; Fagerström, Maria; Wickström, Lucas; Granåsen, Gabriel; Dahle, Charlotte; Vrethem, Magnus; Sundström, Peter

    2017-07-01

    Multiple sclerosis (MS) is a neurological disorder that causes significantly reduced ability to work, and the Expanded Disability Status Scale (EDSS) is one of the main predictors for reduced work ability. To investigate how work requirements, flexible work conditions and disease-modifying drugs (DMDs) influence the work ability in relation to different EDSS grades in two MS populations. Work ability was studied in two MS populations: one in the southern and one in the northern part of Sweden, both demographically similar. In the latter population, more active work-promoting interventions have been practised and second-generation DMDs have been widely used from the onset of disease for several years. The proportion of MS patients who participated in the workforce or studied was significantly higher in the northern compared with the southern population ( p work conditions and were able to work more hours per week. Higher EDSS was associated with lower reduction in number of worked hours per week in the northern population ( p = 0.042). Our data indicated that treatment strategy and adjusted work conditions have impact on work ability in MS.

  5. Influence of working conditions on job satisfaction in anaesthetists.

    Science.gov (United States)

    Kinzl, J F; Knotzer, H; Traweger, C; Lederer, W; Heidegger, T; Benzer, A

    2005-02-01

    We studied job satisfaction, physical health, emotional well-being and working conditions in 125 Austrian and Swiss anaesthetists. Responses to self-reporting questionnaires were evaluated. Dependent variables included job satisfaction, emotional well-being and physical health. Independent variables included age, sex, marital status, position and working conditions as assessed by the Instrument for Stress-related Job Analysis. Control over work shows a strong effect on job satisfaction in anaesthetists, for example influence on handling tasks (P=0.001), time control (P=0.002) and participation (P=0.001), whereas task demands and task-related problems did not have any effect. Anaesthetists in leading positions and specialists reported lower job satisfaction (P=0.012) than did anaesthetists in non-leading positions. Job satisfaction was associated with better physical health (P=0.001) and better emotional well-being (P=0.005). Our results suggest that a high level of job satisfaction in anaesthetists correlates with interesting work demands and the opportunity to contribute skills and ideas. To improve job satisfaction, more attention should be paid to improving working conditions, including control over decision-making, and allowing anaesthetists to have more influence on their own work pace and work schedule.

  6. Structure and Properties of Silica Glass Densified in Cold Compression and Hot Compression

    Science.gov (United States)

    Guerette, Michael; Ackerson, Michael R.; Thomas, Jay; Yuan, Fenglin; Bruce Watson, E.; Walker, David; Huang, Liping

    2015-10-01

    Silica glass has been shown in numerous studies to possess significant capacity for permanent densification under pressure at different temperatures to form high density amorphous (HDA) silica. However, it is unknown to what extent the processes leading to irreversible densification of silica glass in cold-compression at room temperature and in hot-compression (e.g., near glass transition temperature) are common in nature. In this work, a hot-compression technique was used to quench silica glass from high temperature (1100 °C) and high pressure (up to 8 GPa) conditions, which leads to density increase of ~25% and Young’s modulus increase of ~71% relative to that of pristine silica glass at ambient conditions. Our experiments and molecular dynamics (MD) simulations provide solid evidences that the intermediate-range order of the hot-compressed HDA silica is distinct from that of the counterpart cold-compressed at room temperature. This explains the much higher thermal and mechanical stability of the former than the latter upon heating and compression as revealed in our in-situ Brillouin light scattering (BLS) experiments. Our studies demonstrate the limitation of the resulting density as a structural indicator of polyamorphism, and point out the importance of temperature during compression in order to fundamentally understand HDA silica.

  7. Self-help cognitive behavior therapy for working women with problematic hot flushes and night sweats (MENOS@Work): a multicenter randomized controlled trial.

    Science.gov (United States)

    Hardy, Claire; Griffiths, Amanda; Norton, Sam; Hunter, Myra S

    2018-05-01

    The aim of the study was to examine the efficacy of an unguided, self-help cognitive behavior therapy (SH-CBT) booklet on hot flush and night sweat (HFNS) problem rating, delivered in a work setting. Women aged 45 to 60 years, having 10 or more problematic HFNS a week, were recruited to a multicenter randomized controlled trial, via the occupational health/human resources departments of eight organizations. Participants were 1:1 randomized to SH-CBT or no treatment waitlist control (NTWC). The primary outcome was HFNS problem rating; secondary outcomes included HFNS frequency, work and social adjustment, sleep, mood, beliefs and behaviors, and work-related variables (absence, performance, turnover intention, and work impairment due to presenteeism). Intention-to-treat analysis was used, and between-group differences estimated using linear mixed models. A total of 124 women were randomly allocated to SH-CBT (n = 60) and NTWC (n = 64). 104 (84%) were assessed for primary outcome at 6 weeks and 102 (82%) at 20 weeks. SH-CBT significantly reduced HFNS problem rating at 6 weeks (SH-CBT vs NTWC adjusted mean difference, -1.49; 95% CI, -2.11 to -0.86; P work and social adjustment; sleep, menopause beliefs, HFNS beliefs/behaviors at 6 and 20 weeks; improved wellbeing and somatic symptoms and reduced work impairment due to menopause-related presenteeism at 20 weeks, compared with the NTWC. There was no difference between groups in other work-related outcomes. A brief, unguided SH-CBT booklet is a potentially effective management option for working women experiencing problematic HFNS.

  8. 29 CFR 1620.18 - Jobs performed under similar working conditions.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Jobs performed under similar working conditions. 1620.18... THE EQUAL PAY ACT § 1620.18 Jobs performed under similar working conditions. (a) In general. In order for the equal pay standard to apply, the jobs are required to be performed under similar working...

  9. Socioeconomic inequalities in health in the working population: the contribution of working conditions

    NARCIS (Netherlands)

    C.Th.M. Schrijvers (Carola); H. van de Mheen (Dike); K. Stronks (Karien); J.P. Mackenbach (Johan)

    1998-01-01

    textabstractBACKGROUND: The aim was to study the impact of different categories of working conditions on the association between occupational class and self-reported health in the working population. METHODS: Data were collected through a postal survey conducted in 1991

  10. Criticality conditions of heterogeneous energetic materials under shock loading

    Science.gov (United States)

    Nassar, Anas; Rai, Nirmal Kumar; Sen, Oishik; Udaykumar, H. S.

    2017-06-01

    Shock interaction with the microstructural heterogeneities of energetic materials can lead to the formation of locally heated regions known as hot spots. These hot spots are the potential sites where chemical reaction may be initiated. However, the ability of a hot spot to initiate chemical reaction depends on its size, shape and strength (temperature). Previous study by Tarver et al. has shown that there exists a critical size and temperature for a given shape (spherical, cylindrical, and planar) of the hot spot above which reaction initiation is imminent. Tarver et al. assumed a constant temperature variation in the hot spot. However, the meso-scale simulations show that the temperature distribution within a hot spot formed from processes such as void collapse is seldom constant. Also, the shape of a hot spot can be arbitrary. This work is an attempt towards development of a critical hot spot curve which is a function of loading strength, duration and void morphology. To achieve the aforementioned goal, mesoscale simulations are conducted on porous HMX material. The process is repeated for different loading conditions and void sizes. The hot spots formed in the process are examined for criticality depending on whether they will ignite or not. The metamodel is used to obtain criticality curves and is compared with the critical hot spot curve of Tarver et al.

  11. Study on hybrid ground-coupled heat pump system for air-conditioning in hot-weather areas like Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Man, Y.; Yang, H.X. [Hong Kong Polytechnic Univ., Renewable Energy Research Group, Hung Hom, Kowloon, (Hong Kong). Dept. of Building Services Engineering

    2008-07-01

    Due to its high energy efficiency and reliable operation capability, the ground-coupled heat pump (GCHP) system is becoming attractive for air-conditioning in some moderate-weather regions. However, when the technology is used in buildings where there is only cooling load in hot-weather areas such as Hong Kong, the heat rejected into the ground by the GCHP systems will accumulate around the ground heat exchangers (GHE), resulting in degradation of system performance and increased system operating costs. This problem can be resolved by using a hybrid ground-coupled heat pump (HGCHP) system, as it uses supplemental heat rejecters to reject the accumulated heat. By modeling the heat transfer process of the system's main components, this paper presented a practical hourly simulation model of the HGCHP system. Based on this hourly simulation model, the computer program could be used to calculate the hour-by-hour operation data of the HGCHP system according to the cooling and hot water heating loads of a building. The paper discussed a case study that involved a design of both a HGCHP system and a traditional GCHP system for a hypothetical private residential building located in Hong Kong. The economic comparisons were performed between these two types of systems. It was concluded through the simulations that the HGCHP system could effectively solve the heat accumulation problem and reduce both the initial cost and operating cost of the air-conditioning system in the building. 19 refs., 1 tab., 13 figs.

  12. Physicochemical and phytochemical properties of cold and hot water extraction from Hibiscus sabdariffa.

    Science.gov (United States)

    Ramirez-Rodrigues, Milena M; Plaza, Maria L; Azeredo, Alberto; Balaban, Murat O; Marshall, Maurice R

    2011-04-01

    Hibiscus cold (25 °C) and hot (90 °C) water extracts were prepared in various time-temperature combinations to determine equivalent extraction conditions regarding their physicochemical and phytochemical properties. Equivalent anthocyanins concentration was obtained at 25 °C for 240 min and 90 °C for 16 min. Total phenolics were better extracted with hot water that also resulted in a higher antioxidant capacity in these extracts. Similar polyphenolic profiles were observed between fresh and dried hibiscus extracts. Hibiscus acid and 2 derivatives were found in all extracts. Hydroxybenzoic acids, caffeoylquinic acids, flavonols, and anthocyanins constituted the polyphenolic compounds identified in hibiscus extracts. Two major anthocyanins were found in both cold and hot extracts: delphynidin-3-sambubioside and cyanidin-3-sambubioside. In general, both cold and hot extractions yielded similar phytochemical properties; however, under cold extraction, color degradation was significantly lower and extraction times were 15-fold longer. Hibiscus beverages are prepared from fresh or dried calyces by a hot extraction and pasteurized, which can change organoleptic, nutritional, and color attributes. Nonthermal technologies such as dense phase carbon dioxide may maintain their fresh-like color, flavor, and nutrients. This research compares the physicochemical and phytochemical changes resulting from a cold and hot extraction of fresh and dried hibiscus calyces and adds to the knowledge of work done on color, quality attributes, and antioxidant capacity of unique tropical products. In addition, the research shows how these changes could lead to alternative nonthermal processes for hibiscus.

  13. [HYGIENIC ASSESSMENT OF WORKING CONDITIONS OF EMPLOYEES OF BROADCASTING CENTER].

    Science.gov (United States)

    Kovalenko, A V; Brusentsova, A V; Sokhoshko, I A; Rostikov, V P

    2015-01-01

    Hygienic assessment of working conditions of employees of the Omsk Regional Broadcasting Centre was performed on data of the analysis of materials of certification of workplaces. There were examined materials concerning 65 core profile workplaces, where 130 persons, including 35 women work. There was determined health risk for personnel in dependence on working conditions. The staff was noted to be exposed to the adverse impact of the following factors: chemical, physical (noise, general and local vibration, non-ionizing radiation, microclimate, lighting), severity and intensity ofwork. Class working conditions for 13,5% of workplaces on noise, 35.4% on non-ionizing radiation was assessed as a harmful of the first degree. Lightness indices at 78.5% of the workplaces did not meet the requirements of sanitary norms. At 7.7% of the workplaces levels of hardness of labor were assessed as harmful. The impact of such factors as biological, infrasound, ultrasound, ionizing radiation, aerosols with mainly fibrogenic action, was absent, their assessment was not carried out. Working conditions at 83.1% of workplaces were characterized as hazardous, including at 52.3% of the workplaces where there was established hazard class 3.1, at 30.7% of workplaces--Class 3.2. Among all the factors of occupational environment the largest contribution into the overall assessment of working conditions was made by the lightness factor (50.9%) and non-ionizing radiation (20.6%). The most harmful working conditions have been identified for workplaces of the operator of masthead antenna, engineer of radiocommunications, broadcasting and television, electromechanician of television (radiocommunication), (broadcasting), car driver.

  14. Maternal Work Conditions and Child Development

    Science.gov (United States)

    Felfe, Christina; Hsin, Amy

    2012-01-01

    How do maternal work conditions, such as psychological stress and physical hazards, affect children's development? Combining data from the Child Development Supplement of the Panel Study of Income Dynamics and the Occupational Information Network allows us to shed some light on this question. We employ various techniques including OLS with…

  15. Pay, Working Conditions, and Teacher Quality

    Science.gov (United States)

    Hanushek, Eric A.; Rivkin, Steven G.

    2007-01-01

    Eric Hanushek and Steven Rivkin examine how salary and working conditions affect the quality of instruction in the classroom. The wages of teachers relative to those of other college graduates have fallen steadily since 1940. Today, average wages differ little, however, between urban and suburban districts. In some metropolitan areas urban…

  16. [History of hot spring bath treatment in China].

    Science.gov (United States)

    Hao, Wanpeng; Wang, Xiaojun; Xiang, Yinghong; Gu Li, A Man; Li, Ming; Zhang, Xin

    2011-07-01

    As early as the 7th century B.C. (Western Zhou Dynasty), there is a recording as 'spring which contains sulfur could treat disease' on the Wentang Stele written by WANG Bao. Wenquan Fu written by ZHANG Heng in the Easten Han Dynasty also mentioned hot spring bath treatment. The distribution of hot springs in China has been summarized by LI Daoyuan in the Northern Wei Dynasty in his Shuijingzhu which recorded hot springs in 41 places and interpreted the definition of hot spring. Bencao Shiyi (by CHEN Cangqi, Tang Dynasty) discussed the formation of and indications for hot springs. HU Zai in the Song Dynasty pointed out distinguishing hot springs according to water quality in his book Yuyin Conghua. TANG Shenwei in the Song Dynasty noted in Jingshi Zhenglei Beiji Bencao that hot spring bath treatment should be combined with diet. Shiwu Bencao (Ming Dynasty) classified hot springs into sulfur springs, arsenicum springs, cinnabar springs, aluminite springs, etc. and pointed out their individual indications. Geologists did not start the work on distribution and water quality analysis of hot springs until the first half of the 20th century. There are 972 hot springs in Wenquan Jiyao (written by geologist ZHANG Hongzhao and published in 1956). In July 1982, the First National Geothermal Conference was held and it reported that there were more than 2600 hot springs in China. Since the second half of the 20th century, hot spring sanatoriums and rehabilitation centers have been established, which promoted the development of hot spring bath treatment.

  17. The importance of organizational characteristics for psychosocial working conditions and health

    OpenAIRE

    Bolin, Malin

    2009-01-01

    The importance of organizations for understanding differences in the working conditions and health of employees is often emphasized but rarely explored empirically. The general aim of this thesis is to describe organizational characteristics of workplaces, and to assess their impact on the psychosocial working conditions and health of employees. In modern working life, it is assumed that employees' working conditions and health are affected by a general transformation of workplaces from burea...

  18. [An Exploration of Working Conditions and Flexible System for Hospital Nurses].

    Science.gov (United States)

    Huang, Chung-I; Yu, Chien; Yu, Chin-Cheh

    2016-04-01

    The lack of sufficient numbers of professional nurses in the healthcare system in Taiwan is an issue that affects the sustainability of this system and that relates closely to working conditions. The present study explores the expectations that nurses hold with regard to working conditions and the operation of a flexible system in hospitals. A literature review and focus-group interviews were used to develop the questionnaire Working Conditions and Flexible System. A total of 1,150 copies of this questionnaire were distributed to practicing nurses using stratified random sampling, with 1,146 valid copies returned for a valid recovery rate of 99.65%. The results show that the expectations of participants concerning working conditions and a flexible system focus on the 6 factors of task, numerical, divisional, temporal, wages, and leading flexibility. The total mean was 4.35 (SD=0.42). The means for the 6 types of flexibility were all greater than 4.0. Participants deemed flexibility to be of high importance. The demographic variables hospital, work location, age, education level, work position, work unit, and total work years all affected the 6 types of flexibility significantly. The present study supports that the retention of nurses is significantly associated with working conditions and the operation of a flexible system. Administrators and mangers must create positive working conditions and a flexible system in order to enhance the retention and career development of nurses.

  19. Work readiness tools for young adults with chronic conditions.

    Science.gov (United States)

    Metzinger, Courtney; Berg, Christine

    2015-01-01

    Young adults with chronic health conditions can experience barriers to work performance, ability, and their present and future worker roles. Work readiness resources can expand individuals' work skills, abilities, and interests. Five work readiness tools are presented (1) building an occupational profile, (2) generating environmental strategies, (3) on-the-job strategy use, and exploration of online tools (4) O*NET® and (5) O*NET® Interest Profiler, along with two theories (Knowles's Andragogy and Lawton's Ecological Model) to guide tool use. Use of these tools can assist young adults to better manage their health and expand their vocational identities for success at work. These approaches and tools support health professionals, community partners, and vocational organizations in their efforts to help young adults with chronic conditions.

  20. Hot pressing of B{sub 4}C/SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, F.C.; Turhan, E.; Yesilcubuk, S.A.; Addemir, O. [Ystanbul Technical University, Faculty of Chemistry and Metallurgy, Materials and Metallurgical Engineering Dept., Maslak-Ystanbul (Turkey)

    2005-07-01

    B{sub 4}C/SiC ceramic composites containing 10-20-30 vol % SiC were prepared by hot pressing method. The effect of SiC addition and hot pressing temperature on sintering behaviour and mechanical properties of hot pressed composites were investigated. Microstructures of hot pressed samples were examined by SEM technique. Three different temperatures (2100 deg. C, 2200 deg. C and 2250 deg. C) were used to optimize hot pressing temperature applying 100 MPa pressure under argon atmosphere during the sintering procedure. The highest relative density of 98.44 % was obtained by hot pressing at 2250 deg. C. However, bending strengths of B{sub 4}C/SiC composite samples were lower than monolithic B{sub 4}C in all experimental conditions. (authors)

  1. Risk and resilience: health inequalities, working conditions and sickness benefit arrangements: an analysis of the 2010 European Working Conditions survey.

    Science.gov (United States)

    van der Wel, Kjetil A; Bambra, Clare; Dragano, Nico; Eikemo, Terje A; Lunau, Thorsten

    2015-11-01

    In this article we ask whether the level of sickness benefit provision protects the health of employees, particularly those who are most exposed to hazardous working conditions or who have a little education. The study uses the European Working Condition Survey that includes information on 20,626 individuals from 28 countries. Health was measured by self-reported mental wellbeing and self-rated general health. Country-level sickness benefit provision was constructed using spending data from Eurostat. Group-specific associations were fitted using cross-level interaction terms between sickness benefit provision and physical and psychosocial working conditions respectively, as well as those with little education. The mental wellbeing of employees exposed to psychosocial job strain and physical hazards, or who had little education, was better in countries that offer more generous sickness benefit. These results were found in both men and women and were robust to the inclusion of GDP and country fixed effects. In the analyses of self-reported general health, few group-specific associations were found. This article concludes that generous sickness benefit provision may strengthen employee's resilience against mental health risks at work and risks associated with little education. Consequently, in countries with a generous provision of sickness benefit, social inequalities in mental health are smaller. © 2015 Foundation for the Sociology of Health & Illness.

  2. The influence of prior ageing on microstructure, tensile properties and hot hardness of alloy 800HT

    International Nuclear Information System (INIS)

    El-Magd, E.

    1996-01-01

    For high temperature applications especially in the construction of equipment, carbide strengthened steels are widely used because of their good mechanical properties and relatively low cost. These materials undergo microstructural changes under such service conditions which contribute greatly to the strength properties and thus play an important role in equipment design considerations. The influence of a prior thermal ageing on the tensile strength values and the hot hardness of the austenitic iron base alloy, Alloy 800HT, is examined in this work. It was therefore necessary to carry out tensile and hot hardness tests with the solution treated and overaged material at ranges between room temperature and 900 . The microstructural changes are investigated using lightmicroscopy, SEM and TEM. The changes of the material properties with thermal pretreatment conditions is studied and discussed in the context of the determined microstructural development. (orig.) [de

  3. Long Working Hours in Korea: Based on the 2014 Korean Working Conditions Survey

    OpenAIRE

    Park, Jungsun; Kim, Yangho; Han, Boyoung

    2017-01-01

    Background: Long working hours adversely affect worker safety and health. In 2004, Korea passed legislation that limited the work week to 40 hours, in an effort to improve quality-of-life and increase business competitiveness. This regulation was implemented in stages, first for large businesses and then for small businesses, from 2004 to 2011. We previously reported that average weekly working hours decreased from 2006 to 2010, based on the Korean Working Conditions Survey. Methods: In the p...

  4. Assessing the relationships between nurse working conditions and patient outcomes: systematic literature review.

    Science.gov (United States)

    Bae, Sung-Heui

    2011-09-01

    The purpose of the study was to systematically evaluate nurse working conditions and to review the literature dealing with their association with patient outcomes. Improving nurse working conditions is essential to address nursing shortages. Although general reviews of the literature support the positive link between working conditions and patient outcomes, definitive evidence has been lacking. A search of six electronic bibliographic databases was conducted for the primary research published in English, from January 2000 to October 2009. The concepts of working conditions were categorized into 10 groups of working conditions. A total of 69 relationships between working conditions and patient outcomes were examined. Increased attention has been drawn to nurse working conditions resulting from nursing shortages. The findings of this review suggested that the evidence supporting positive relationships between working conditions and patient outcomes is inconclusive. Further studies of a longitudinal and interventional nature in various settings are needed to advance knowledge of the complex contextual and multivariate influences among nurse working conditions and patient outcomes. Efforts to improve working conditions should be made in various health-care work settings to ensure patient safety and improve patient quality of outcomes. 2011 Blackwell Publishing Ltd.

  5. Hot deformation behavior of delta-processed superalloy 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y., E-mail: wangyanhit@yahoo.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Aeronautics and Astronautics, Central South University, Changsha 410083 (China); Shao, W.Z.; Zhen, L.; Zhang, B.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-03-25

    Research highlights: {yields} The peak stress for hot deformation can be described by the Z parameter. {yields} The grain size of DRX was inversely proportional to the Z parameter. {yields} The dissolution of {delta} phases was greatly accelerated under hot deformation. {yields}The {delta} phase stimulated nucleation can serve as the main DRX mechanism. - Abstract: Flow stress behavior and microstructures during hot compression of delta-processed superalloy 718 at temperatures from 950 to 1100 deg. C with strain rates of 10{sup -3} to 1 s{sup -1} were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM). The relationship between the peak stress and the deformation conditions can be expressed by a hyperbolic-sine type equation. The activation energy for the delta-processed superalloy 718 is determined to be 467 kJ/mol. The change of the dominant deformation mechanisms leads to the decrease of stress exponent and the increase of activation energy with increasing temperature. The dynamically recrystallized grain size is inversely proportional to the Zener-Hollomon (Z) parameter. It is found that the dissolution rate of {delta} phases under hot deformation conditions is much faster than that under static conditions. Dislocation, vacancy and curvature play important roles in the dissolution of {delta} phases. The main nucleation mechanisms of dynamic recrystallization (DRX) for the delta-processed superalloy 718 include the bulging of original grain boundaries and the {delta} phase stimulated DRX nucleation, which is closely related to the dissolution behavior of {delta} phases under certain deformation conditions.

  6. Safety distance for preventing hot particle ignition of building insulation materials

    OpenAIRE

    Jiayun Song; Supan Wang; Haixiang Chen

    2014-01-01

    Trajectories of flying hot particles were predicted in this work, and the temperatures during the movement were also calculated. Once the particle temperature decreased to the critical temperature for a hot particle to ignite building insulation materials, which was predicted by hot-spot ignition theory, the distance particle traveled was determined as the minimum safety distance for preventing the ignition of building insulation materials by hot particles. The results showed that for sphere ...

  7. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions; FINAL

    International Nuclear Information System (INIS)

    Yi-Wen Cheng; Patrick Purtscher

    1999-01-01

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills

  8. Planning, Management and Organizational Aspects of the Decommissioning of a Hot Cell Facility

    Energy Technology Data Exchange (ETDEWEB)

    Strufe, N. [Danish Decommissioning, Roskilde (Denmark)

    2013-08-15

    This CRP project document ''Planning, Management and Organizational Aspects in Decommissioning of a Hot Cell Facility'' aims to describe the establishment of a management organization that ensures that the DD Hot Cell Project is properly and safely conducted and that staff members, who are seconded to the project, have a strong feeling of ownership and being an integral part of the project. The objectives of the decommissioning project of the hot cell facility is to decontaminate the facility and to remove items that cannot be decontaminated on site, in order for the entire hot cell building to become useable for other purposes without any radiological restrictions. The project requires proper communication and coordination with all stakeholders on-site, comprehensive work plans and strict control of the individual working areas and operations. A project of this type obviously requires a strong and well managed and coordinated project organization. DD has established a management system - KMS. The purposes of the KMS are twofold. The system aims to secure the fulfilment of the conditions and requirements of quality set by the nuclear authorities. The system also aims to provide the basis for a rational and economically feasible operation with a high level of safety. One of the main lessons learned in this project is clear that is to ensure that the necessary resources are available and the required expertise is allocated timely for the performance of the project(s) a strong coordination and great flexibility within the DD organization is required. This document describes the approach and considerations from the project management point of view. The document initially gives an introduction to the hot cell decommissioning project followed by issues of the general considerations and planning of the project within the DD, including aspects on organisation, quality assurance and coordination. (author)

  9. HOT 2012

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen......Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen...

  10. Hot deformation and processing maps of K310 cold work tool steel

    International Nuclear Information System (INIS)

    Ezatpour, H.R.; Sajjadi, S.A.; Haddad-Sabzevar, M.; Ebrahimi, G.R.

    2012-01-01

    Highlights: ► The steady state stresses are related to strain rate and temperature. ► The study led to n DRX = 3.95 and Q DRX = 219.65 kJ/(mol K) and α = 1.2 × 10 −2 MPa −1 . ► The safe domain occurs in the region of 1000–1100 °C for a strain rate of 0.1 s −1 . - Abstract: Hot working response of cold work tool steel K310 was investigated by means of compression test at temperature range of 900–1100 °C. The equivalent strain rates used in these tests were 0.01, 0.1 and 1 s −1 , respectively in order to obtain the processing and stability maps of the studied material following the Dynamic Material Model. All the zones of flow instability were studied through scanning electron microscopy (SEM). The microstructure of the samples after deformation was then analyzed by light microscopy and the differences were compared together. The steady state stress obtained from the flow curves was related to strain rate (ε . ) and temperature (T) by means of the well known Zener–Holloman equation. A least square analysis of the data led to n = 3.95 and Q DRX = 219.65 kJ/mol and α = 1.2 × 10 −2 MPa −1 . Also, hardness results showed that by increasing strain from peak to steady state strain, hardness was decreased.

  11. Should Workers Avoid Consumption of Chilled Fluids in a Hot and Humid Climate?

    Directory of Open Access Journals (Sweden)

    Matt B. Brearley

    2017-12-01

    Full Text Available Despite provision of drinking water as the most common method of occupational heat stress prevention, there remains confusion in hydration messaging to workers. During work site interactions in a hot and humid climate, workers commonly report being informed to consume tepid fluids to accelerate rehydration. When questioned on the evidence supporting such advice, workers typically cite that fluid absorption is delayed by ingestion of chilled beverages. Presumably, delayed absorption would be a product of fluid delivery from the gut to the intestines, otherwise known as gastric emptying. Regulation of gastric emptying is multifactorial, with gastric volume and beverage energy density the primary factors. If gastric emptying is temperature dependent, the impact of cooling is modest in both magnitude and duration (≤ 5 minutes due to the warming of fluids upon ingestion, particularly where workers have elevated core temperature. Given that chilled beverages are most preferred by workers, and result in greater consumption than warm fluids during and following physical activity, the resultant increased consumption of chilled fluids would promote gastric emptying through superior gastric volume. Hence, advising workers to avoid cool/cold fluids during rehydration appears to be a misinterpretation of the research. More appropriate messaging to workers would include the thermal benefits of cool/cold fluid consumption in hot and humid conditions, thereby promoting autonomy to trial chilled beverages and determine personal preference. In doing so, temperature-based palatability would be maximized and increase the likelihood of workers maintaining or restoring hydration status during and after their work shift. Keywords: Fluid consumption, gastric emptying, hot and humid conditions, hydration, occupational

  12. Hot-Gas Filter Ash Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, M.L.; Hurley, J.P.; Dockter, B.A.; O`Keefe, C.A.

    1997-07-01

    Large-scale hot-gas filter testing over the past 10 years has revealed numerous cases of cake buildup on filter elements that has been difficult, if not impossible, to remove. At times, the cake can blind or bridge between candle filters, leading to filter failure. Physical factors, including particle-size distribution, particle shape, the aerodynamics of deposition, and system temperature, contribute to the difficulty in removing the cake, but chemical factors such as surface composition and gas-solid reactions also play roles in helping to bond the ash to the filters or to itself. This project is designed to perform the research necessary to determine the fuel-, sorbent-, and operations-related conditions that lead to blinding or bridging of hot-gas particle filters. The objectives of the project are threefold: (1) Determine the mechanisms by which a difficult-to-clean ash is formed and how it bridges hot-gas filters (2) Develop a method to determine the rate of bridging based on analyses of the feed coal and sorbent, filter properties, and system operating conditions and (3) Suggest and test ways to prevent filter bridging.

  13. VARIABILITY IN HOT CARBON-DOMINATED ATMOSPHERE (HOT DQ) WHITE DWARFS: RAPID ROTATION?

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kurtis A.; Bierwagen, Michael [Department of Physics and Astrophysics, Texas A and M University-Commerce, P.O. Box 3011, Commerce, TX, 75429 (United States); Montgomery, M. H.; Winget, D. E.; Falcon, Ross E., E-mail: Kurtis.Williams@tamuc.edu [Department of Astronomy, University of Texas, 1 University Station C1400, Austin, TX, 78712 (United States)

    2016-01-20

    Hot white dwarfs (WDs) with carbon-dominated atmospheres (hot DQs) are a cryptic class of WDs. In addition to their deficiency of hydrogen and helium, most of these stars are highly magnetic, and a large fraction vary in luminosity. This variability has been ascribed to nonradial pulsations, but increasing data call this explanation into question. We present studies of short-term variability in seven hot DQ WDs. Three (SDSS J1426+5752, SDSS J2200−0741, and SDSS J2348−0942) were known to be variable. Their photometric modulations are coherent over at least two years, and we find no evidence for variability at frequencies that are not harmonics. We present the first time-series photometry for three additional hot DQs (SDSS J0236−0734, SDSS J1402+3818, and SDSS J1615+4543); none are observed to vary, but the signal-to-noise is low. Finally, we present high speed photometry for SDSS J0005−1002, known to exhibit a 2.1-day photometric variation; we do not observe any short-term variability. Monoperiodicity is rare among pulsating WDs, so we contemplate whether the photometric variability is due to rotation rather than pulsations; similar hypotheses have been raised by other researchers. If the variability is due to rotation, then hot DQ WDs as a class contain many rapid rotators. Given the lack of companions to these stars, the origin of any fast rotation is unclear—both massive progenitor stars and double degenerate merger remnants are possibilities. We end with suggestions of future work that would best clarify the nature of these rare, intriguing objects.

  14. [WORKING CONDITIONS AND STATE OF HEALTH OF TBILISI SUBWAY EMPLOYEES].

    Science.gov (United States)

    Khunashvili, N; Tsimakuridze, Mar; Bakradze, L; Khachapuridze, N; Tsimakuridze, Maya

    2017-03-01

    For the purpose of preventive events complex hygienic, clinical-functional, laboratory and biostatic researches are implemented on the basis of Tbilisi Subway. Conditions of work are characterized by complex of unfavorable factors of the working environment and the labor process. Working environment is characterized by combination of unfavorable state of physical factors and air pollution with dust and toxic substances. The levels of noise and vibration refer to the 3.4 class of harmfulness. The content of dust and toxic substances corresponds to 3.1-3.2 classes of working conditions harmfulness. In the indexes of health status, the leading diseases are pathology of cardiovascular, nervous and digestive systems. Cause-effect relationships between working conditions and individual health indicators have been already established, which served as the basis for the development of comprehensive preventive health measures.

  15. Modeling the Process of Event Sequence Data Generated for Working Condition Diagnosis

    Directory of Open Access Journals (Sweden)

    Jianwei Ding

    2015-01-01

    Full Text Available Condition monitoring systems are widely used to monitor the working condition of equipment, generating a vast amount and variety of telemetry data in the process. The main task of surveillance focuses on analyzing these routinely collected telemetry data to help analyze the working condition in the equipment. However, with the rapid increase in the volume of telemetry data, it is a nontrivial task to analyze all the telemetry data to understand the working condition of the equipment without any a priori knowledge. In this paper, we proposed a probabilistic generative model called working condition model (WCM, which is capable of simulating the process of event sequence data generated and depicting the working condition of equipment at runtime. With the help of WCM, we are able to analyze how the event sequence data behave in different working modes and meanwhile to detect the working mode of an event sequence (working condition diagnosis. Furthermore, we have applied WCM to illustrative applications like automated detection of an anomalous event sequence for the runtime of equipment. Our experimental results on the real data sets demonstrate the effectiveness of the model.

  16. Tennis in hot and cool conditions decreases the rapid muscle torque production capacity of the knee extensors but not of the plantar flexors

    Science.gov (United States)

    Girard, Olivier; Racinais, Sébastien; Périard, Julien D

    2014-01-01

    Objectives To assess the time course of changes in rapid muscle force/torque production capacity and neuromuscular activity of lower limb muscles in response to prolonged (∼2 h) match-play tennis under heat stress. Methods The rates of torque development (RTD) and electromyographic activity (EMG; ie, root mean square) rise were recorded from 0 to 30, –50, –100 and –200 ms during brief (3–5 s) explosive maximal isometric voluntary contractions (MVC) of the knee extensors (KE) and plantar flexors (PF), along with the peak RTD within the entirety of the torque-time curve. These values were recorded in 12 male tennis players before (prematch) and after (postmatch, 24 and 48 h) match-play in HOT (∼37°C) and COOL (∼22°C) conditions. Results The postmatch core temperature was greater in the HOT (∼39.4°C) vs COOL (∼38.7°C) condition (ptorque. Furthermore, the rate of KE EMG activity rise remained unchanged. Conversely, the PF contractile RTD and rate of EMG activity rise were unaffected by the exercise or environmental conditions. Conclusions In the KE, a reduction in maximal torque production capacity following prolonged match-play tennis appears to account for the decrease in the rate of torque development, independent of environmental conditions, while remaining unchanged in the PF. PMID:24668381

  17. Teachers’ Working Conditions Amid Swedish School Choice Reform: Avenues for Further Research

    Directory of Open Access Journals (Sweden)

    Karolina Åsa Parding

    2016-04-01

    Full Text Available Since the 1990s, governance changes, including customer choice agendas, have permeated the public sector and, consequently, welfare sector professionals’ work. One example is the education sector. The aim of this paper is to identify and discuss avenues for further research when it comes to teachers’ working conditions in the light of current choice agendas. This is accomplished by presenting an overview of previous studies on implications of the reforms for teachers’ working conditions. How are these conditions described in relation to the current school choice agenda in Sweden? What directions should be applied to increase knowledge of these conditions? We conclude by identifying some avenues for further research: the issues of organization of work, temporal and spatial dimensions of working conditions, and finally comparative studies of various forms, are suggested as warranting further investigation to highlight the diversified labor market in which teachers find themselves today.Keywords: Competition, governance change, privatization, professional work, school choice, Sweden, teaching profession, working conditions

  18. Working conditions in hospitals in the European Union

    NARCIS (Netherlands)

    Verschuren, R.; Groot, B. de; Nossent, S.

    1995-01-01

    This study reflects the main results of one part of the study 'Monitoring the work environment at sectorial level'. This part regards the hospital sector in Europe. In this study, which was a project of the European Foundation for the Improvement of Living and Working conditions, ten member states

  19. Working conditions in the European meat processing industry

    NARCIS (Netherlands)

    Nossent, S.; Groot, B. de; Verschuren, R.

    1995-01-01

    This report reflects the main results of one part of the study 'Monitoring the work environment at sectorial level'. This part regards the meat processing industry in Europe. In this study, which was a project of the European Foundation for Living and Working Conditions, ten member states of the

  20. Hydrothermal pretreatment of wood by mild steam explosion and hot water extraction.

    Science.gov (United States)

    Wojtasz-Mucha, Joanna; Hasani, Merima; Theliander, Hans

    2017-10-01

    The aim of this work was to compare the two most common hydrothermal pre-treatments for wood - mild steam explosion and hot water extraction - both with the prospect of enabling extraction of hemicelluloses and facilitating further processing. Although both involve autohydrolysis of the lignocellulosic tissue, they are performed under different conditions: the most prominent difference is the rapid, disintegrating, discharge employed in the steam explosion opening up the structure. In this comparative study, the emphasis was placed on local composition of the pre-treated wood chips (of industrially relevant size). The results show that short hot water extraction treatments lead to significant variations in the local composition within the wood chips, while steam explosion accomplishes a comparably more even removal of hemicelluloses due to the advective mass transport during the explosion step. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. 26 CFR 1.132-5 - Working condition fringes.

    Science.gov (United States)

    2010-04-01

    ... exist unless the employee's employer establishes to the satisfaction of the Commissioner that an overall... example, threats are made on the life of an employee), the bona fide business-oriented security concern is... condition fringe. A “working condition fringe” is any property or service provided to an employee of an...

  2. Mechanical properties of copper-lithium alloys produced by mechanic alloyed and hot extrusion

    International Nuclear Information System (INIS)

    Castillo B, Ricardo; Gorziglia S, Ezio; Penaloza V, Augusto

    2004-01-01

    In this work are presented the progress carried out on the characterization of some physical and mechanical properties, together with the determination of the micro mechanism of fracture of the Cu-2% wt Li, that was obtained by mechanical alloying followed hot extrusion at 500 o C and 700 o C. Hardness and tensile mechanical tests were performed together with metallographic and fractographic analysis. The experimental results obtained with powders of the Cu-Li alloy studied are compared with powder of pure copper, under similar test conditions. The results show that by hot extrusion was allowed to obtain very high densification levels for the materials under study. Moreover, it was found that lithium reduce both the tensile strength and elongation, of copper by a mechanism of embrittlement. The results are compares with the literature (au)

  3. [Women in informal economy health and work conditions Bogotá. 2007].

    Science.gov (United States)

    Sotelo-Suárez, Nidia R; Quiroz-Arcentáles, Jorge L; Mahecha-Montilla, Charo P; López-Sánchez, Paola A

    2012-06-01

    To determine work and health conditions of women working in informal economy in Bogotá, as well as to recommend priority action plans for preventing illnesses and accidents related to work and their consequences. Descriptive observational study. This study analyzed information collected by local groups in work-related contexts during 2007 as part of a set of forms of intervention established according to the Plan de Atención Básica (Primary Care Plan). This plan included 3 715 units of informal work from every point of the city. 3 936 women registers in all were analyzed. This study reveals evident precariousness conditions of women in this economic sector. Specifically, there are certain evident conditions that had shown in this study such as low education levels, incomes below the minimum legal standards, high exposure to damaging health work conditions, long work hours, and few hours for leisure and free time. Furthermore, 75 % of women included in this study are female head of household. This condition makes them more vulnerable to a heavier family and social burden. Closer attention to informal economy phenomenon is suggested in order to avoid vulnerable conditions of working women. Besides, it is necessary to improve the articulation between Academy and forms of intervention through public policies for knowing deeply repeated phenomena regarding the population of study. This articulation can be thought for implementing programs designed for improving women's quality of life.

  4. Sleep complaints in middle-aged women and men: the contribution of working conditions and work-family conflicts.

    Science.gov (United States)

    Lallukka, Tea; Rahkonen, Ossi; Lahelma, Eero; Arber, Sara

    2010-09-01

    This study aimed to examine how physical working conditions, psychosocial working conditions and work-family conflicts are associated with sleep complaints, and whether health behaviours explain these associations. We used pooled postal questionnaire surveys collected in 2001-2002 among 40-60-year-old employees of the City of Helsinki (n = 5819, response rate 66%). Participants were classified as having sleep complaints if they reported sleep complaints at least once a week on average (24% of women and 20% of men). Independent variables included environmental work exposures, physical workload, computer work, Karasek's job strain and work-family conflicts. Age, marital status, occupational class, work arrangements, health behaviours and obesity were adjusted for. Most working conditions were associated strongly with sleep complaints after adjustment for age only. After adjustment for work-family conflicts, the associations somewhat attenuated. Work-family conflicts were also associated strongly with women's [odds ratio (OR) 5.90; confidence interval (CI) 4.16-8.38] and men's sleep (OR 2.56; CI 1.34-4.87). The associations remained robust even after controlling for unhealthy behaviours, obesity, health status, depression and medications. Physically strenuous working conditions, psychosocial job strain and work-family conflicts may increase sleep complaints. Efforts to support employees to cope with psychosocial stress and reach a better balance between paid work and family life might reduce sleep complaints. Sleep complaints need to be taken into account in worksite health promotion and occupational health care in order to reduce the burden of poor sleep.

  5. Psychosocial working conditions and stress in UK social workers

    OpenAIRE

    Ravalier, J.M

    2018-01-01

    It is well documented that exposure to chronic negative working conditions leads to stress. This subsequently impacts sickness absence and attrition, making it a key consideration for policymakers and academics alike. This study therefore seeks to investigate the influence of psychosocial working conditions on stress and related outcomes: sickness presenteeism, job satisfaction, and turnover intentions in UK social workers (SWs). A cross-sectional survey was used, in addition to a single open...

  6. Examining the relationship between psychosocial working conditions, physical work demands, and leisure time physical activity in Canada.

    Science.gov (United States)

    Morassaei, Sara; Smith, Peter M

    2011-10-01

    To examine the effects of psychosocial working conditions and physical work demands on leisure time physical activity (LTPA). Using path analysis, direct and indirect effects of self-reported working conditions on LTPA levels were assessed in a representative sample of 4167 workers from the 2000 to 2001 Canadian National Population Health Survey. Higher levels of skill discretion and decision latitude were associated with higher LTPA. Physical work demands had opposite effects among men versus women, and skill discretion had a stronger effect among women than among men. Job security had a stronger effect on older workers and those without children younger than 13 years. The results support the influence of the work environment on LTPA and suggest that certain work conditions should be targeted in future interventions seeking to impact participation in physical activity.

  7. 76 FR 44265 - General Working Conditions in Shipyard Employment; Correction

    Science.gov (United States)

    2011-07-25

    ... DEPARTMENT OF LABOR Occupational Safety and Health Administration 29 CFR Part 1910 [Docket No. OSHA-S049-2006-0675 (Formerly Docket No. S-049)] RIN 1218-AB50 General Working Conditions in Shipyard... on General Working Conditions in Shipyard Employment published in the Federal Register of May 2, 2011...

  8. Wear Behavior of Uncoated and Coated Tools under Complex Loading Conditions

    Directory of Open Access Journals (Sweden)

    M. Wieland

    2012-03-01

    Full Text Available In automotive industry crash relevant structures of the body in white are manufactured using the direct hot stamping process. Due to the high temperature difference between the hot blank and the cold tool surfaces and the relative movement between the blank and the tool surfaces during the forming operation, high thermal and mechanical loads are applied on the tool leading to excessive wear in terms of adhesion on the tool surfaces. One possibility to reduce wear of hot stamping tools is the application of tool coating systems. In the scope of this work uncoated and coated tools are characterized under complex loading conditions with respect to adhesive layer build-up.

  9. A LOW TEMPERATURE ALUMINIZING TREATMENT OF HOT WORK TOOL STEEL

    OpenAIRE

    Matijević, Božidar

    2013-01-01

    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to the X40CrMoV5-1 hot tool steel. The aluminizing temperature was from 550 °C to 620 °C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the alumini...

  10. Effect of chemical composition and cooling conditions on solidification hot cracking of Ni-based alloys

    International Nuclear Information System (INIS)

    De Vito, Sophie

    2000-01-01

    Ni-based alloys 690 present solidification hot cracks during welding of vapour generators. Hot cracks are qualitatively known to be due to the formation of inter-dendritic liquid films and of secondary phases down to low temperatures. This study aims at establishing the link between thermodynamics, solidification and hot cracking. Experimental solidification paths of high purity alloys (with varying Nb and Si contents) are obtained from quenching during directional solidification and TIG-welding experiments. They are compared to Thermo-Calc computations, assuming no diffusion in the solid. From directional solidification samples, good agreement between computed and experimental solidification paths is shown in the quenched liquid. Secondary arms of dendrites are affected by solid state diffusion of Nb. Combined effect of diffusion and solute build-up in the liquid phase modifies micro-segregation in the solid region. Solidification paths from welding specimens are similar to those of the solid region of quenched samples. Nb solid state diffusion is negligible but undercooling compensates the effect of solid state diffusion in directional solidification. Evolution of liquid fraction at the end of the solidification is in accordance with the hot cracking classification of the alloys. Nb favours formation of inter-dendritic liquid films and eutectic-like phases down to low temperature. (author) [fr

  11. Performance study of protective clothing against hot water splashes: from bench scale test to instrumented manikin test.

    Science.gov (United States)

    Lu, Yehu; Song, Guowen; Wang, Faming

    2015-03-01

    Hot liquid hazards existing in work environments are shown to be a considerable risk for industrial workers. In this study, the predicted protection from fabric was assessed by a modified hot liquid splash tester. In these tests, conditions with and without an air spacer were applied. The protective performance of a garment exposed to hot water spray was investigated by a spray manikin evaluation system. Three-dimensional body scanning technique was used to characterize the air gap size between the protective clothing and the manikin skin. The relationship between bench scale test and manikin test was discussed and the regression model was established to predict the overall percentage of skin burn while wearing protective clothing. The results demonstrated strong correlations between bench scale test and manikin test. Based on these studies, the overall performance of protective clothing against hot water spray can be estimated on the basis of the results of the bench scale hot water splashes test and the information of air gap size entrapped in clothing. The findings provide effective guides for the design and material selection while developing high performance protective clothing. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

  12. Hot forging of roll-cast high aluminum content magnesium alloys

    Science.gov (United States)

    Kishi, Tomohiro; Watari, Hisaki; Suzuki, Mayumi; Haga, Toshio

    2017-10-01

    This paper reports on hot forging of high aluminum content magnesium alloy sheets manufactured using horizontal twin-roll casting. AZ111 and AZ131 were applied for twin-roll casting, and a hot-forging test was performed to manufacture high-strength magnesium alloy components economically. For twin-roll casting, the casting conditions of a thick sheet for hot forging were investigated. It was found that twin-roll casting of a 10mm-thick magnesium alloy sheet was possible at a roll speed of 2.5m/min. The grain size of the cast strip was 50 to 70µm. In the hot-forging test, blank material was obtained from as-cast strip. A servo press machine with a servo die cushion was used to investigate appropriate forging conditions (e.g., temperature, forging load, and back pressure) for twin-roll casts (TRCs) AZ111 and AZ131. It was determined that high aluminum content magnesium alloy sheets manufactured using twin-roll casting could be forged with a forging load of 150t and a back pressure of 3t at 420 to 430°C. Applying back pressure during hot forging effectively forged a pin-shaped product.

  13. EVALUATION OF THE WORK CONDITIONS OF ACTIVITIES OF URBAN TREE PRUNING

    Directory of Open Access Journals (Sweden)

    Nilton César Fiedler

    2007-03-01

    Full Text Available this work analyzed the work environment in the trees pruning activities in the urban arborization, comparison with the values of the legislation and the practical application of results to provide a better comfort, security, health, welfare to workers, and also a better efficiency and quality of the work. The weather conditions, the noise levels, the light conditions and vibration were analyzed using suitable ergonomic methods. The weather conditions in the work environment were according the permissible values in the legislation (NR15 for index of humid bulb and globe thermometer (IBUTG of 25°C for the activities of pruning, with exception of the schedule to twelve hours (26,2°C, the hours of working should be of 30 minutes of work and 30 minutes of rest. The noise levels found in the activities of cut were 105,7 dB (A and bucking were 103.9 dB (A, above the level permited by legislation (NR15. The minimum light conditions values were acceptable for legislation (NBR 5413/92, but the global indices were too high being able to cause problems to the worker health. The vibration conditions were acceptable.

  14. Analysis of the hot cell lay-out for the advanced spent fuel conditioning process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. Y.; Kim, S. H.; Song, T. G.; Hong, D. H.; Kim, Y. H.; Yoon, J. S

    2003-04-01

    Equipment used for ACP must operate in intense radiation fields enclosed in a hot cell and be remotely maintained. For the reliable remote maintenance operation, several design aspects should be considered. Even though the design results seem to be satisfactory, all the remote operation should be checked prior to the hot demonstration. The best way to check the remote operability is a real mock-up test, but the mock-up test is too expensive and time consuming, and need refabrication of the design to deal with the problem found in the test operation. The 3D graphic simulator gives an alternate solution for this. It can check the remote operability of the process without fabrication of the process equipment. In other words, using a graphic simulator, remote operation task can be simulated in a computer(virtual environment), not the real environment. In this report, for the analysis on the hat cell layout for the ACP process, the verification from the concept of the process to the detailed motion of the equipment and the remote operation devices using virtual prototyping is described. Also, the requirement of the process equipment in the sense of size and remote maintenance, and that of the transportation and handling for the process material are described. Finally, from these results, the hot cell layout alternatives and the bases for the selection of the optimum layout are implemented. The graphical simulator and the results from this analysis can be effectively used not only for optimizing the hot cell layout but also designing the ACP equipment and maintenance process.

  15. Hot Flashes

    Science.gov (United States)

    Hot flashes Overview Hot flashes are sudden feelings of warmth, which are usually most intense over the face, neck and chest. Your skin might redden, as if you're blushing. Hot flashes can also cause sweating, and if you ...

  16. Wall shear stress hot film sensor for use in gases

    International Nuclear Information System (INIS)

    Osorio, O D; Silin, N

    2011-01-01

    The purpose of this work is to present the construction and characterization of a wall shear stress hot film sensor for use in gases made with MEMS technology. For this purpose, several associated devices were used, including a constant temperature feedback bridge and a shear stress calibration device that allows the sensor performance evaluation. The sensor design adopted here is simple, economical and is manufactured on a flexible substrate allowing its application to curved surfaces. Stationary and transient wall shear stress tests were carried on by means of the calibration device, determining its performance for different conditions.

  17. Factors affecting working conditions in public hospitals: A literature review

    Directory of Open Access Journals (Sweden)

    Zodwa M. Manyisa

    2017-01-01

    Findings: Workload, HIV/AIDS epidemic, shift work, long working hours, poor infrastructure, inadequate resources and shortage of staff were found to be the main factors attributed to poor working conditions.

  18. Mental Health of Elementary Schoolteachers in Southern Brazil: Working Conditions and Health Consequences.

    Science.gov (United States)

    Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; de Almeida, Marlise Capa Verde; Rocha, Laurelize Pereira; Borges, Anelise Miritz

    2015-01-01

    The mental health of educators is a growing problem in many countries. This study sought to identify self-reported stressful working conditions of elementary schoolteachers and the biopsychosocial consequences of those working conditions and then identify working conditions that promote well-being for teachers in the workplace. Exploratory study was done with 37 teachers. Data collection was performed using a structured interview with a questionnaire. Results show that stressful working conditions are related to inadequate salary, an excessive number of activities, and having to take work home. Biopsychosocial consequences include anxiety, stress, and sleep disorders. There was a statistically significant association between inadequate salary and anxiety (p = 0.01) and between an excessive number of activities and stress (p = 0.01). Teachers reported that a good relationship among colleagues is a working condition that promotes well-being in the workplace. The identification of stressful working conditions for teachers, the biopsychosocial consequences, and working conditions that promote well-being in the workplace are relevant to determining actions that improve the work environment and, consequently, the health of teachers.

  19. Mental Health of Elementary Schoolteachers in Southern Brazil: Working Conditions and Health Consequences

    Directory of Open Access Journals (Sweden)

    Marta Regina Cezar-Vaz

    2015-01-01

    Full Text Available The mental health of educators is a growing problem in many countries. This study sought to identify self-reported stressful working conditions of elementary schoolteachers and the biopsychosocial consequences of those working conditions and then identify working conditions that promote well-being for teachers in the workplace. Exploratory study was done with 37 teachers. Data collection was performed using a structured interview with a questionnaire. Results show that stressful working conditions are related to inadequate salary, an excessive number of activities, and having to take work home. Biopsychosocial consequences include anxiety, stress, and sleep disorders. There was a statistically significant association between inadequate salary and anxiety (p = 0.01 and between an excessive number of activities and stress (p = 0.01. Teachers reported that a good relationship among colleagues is a working condition that promotes well-being in the workplace. The identification of stressful working conditions for teachers, the biopsychosocial consequences, and working conditions that promote well-being in the workplace are relevant to determining actions that improve the work environment and, consequently, the health of teachers.

  20. WORK CONDITIONS OF CHAINSAW OPERATORS

    Directory of Open Access Journals (Sweden)

    Jorge Roberto Malinovski

    2002-01-01

    Full Text Available The objective of this research was to analyze the human factors and the work conditions in clear-cutting operations using chainsaws in mountainous areas. Data were colected in a forestry company in Minas Gerais, Brazil, by interviews with 29 chainsaw operators. The results indicated that the operators average age was 32.3 years, height 1.68m and body weight 64.4Kg. The average job time in the company was 112 months and the average time of chainsaw operation experience was 81.5 months. Most (93.1% were dexterous and 6.9% were left-handed. The high incidence of backache (41.4% indicated that the task demands an overload of lumbar column, so that the company should take preventive measures to avoid backaches, using educational strategies or changing the opera-tional system. The high level of accidents (44.8% indicated that some precautions are needed to im-prove work safety.

  1. Evaluation of wet bulb globe temperature index for estimation of heat strain in hot/humid conditions in the Persian Gulf

    OpenAIRE

    Habibolah Dehghan; Seyed Bagher Mortazavi; Mohammad J Jafari; Mohammad R Maracy

    2012-01-01

    Background: Heat exposure among construction workers in the Persian Gulf region is a serious hazard for health. The aim of this study was to evaluate the performance of wet bulb globe temperature (WBGT) Index for estimation of heat strain in hot/humid conditions by the use of Physiological Strain Index (PSI) as the gold standard. Material and Methods : This cross-sectional study was carried out on 71 workers of two Petrochemical Companies in South of Iran in 2010 summer. The WBGT index, heart...

  2. Microbial ecology of artisanal Italian Cheese: environment and working conditions

    International Nuclear Information System (INIS)

    Dioguardi, L.; Colombo, E.; Franzetti, L.

    2009-01-01

    In agro-food sector the structural features of working environments and consequently their hygienic conditions are of primary importance for a safe and quality food production and to ensure comfortable and ergonomic working conditions. In particular, as regards high-mountain dairy production, the environment is important because it can affect the development of typical microbial ecosystem. (Author)

  3. Microbial ecology of artisanal Italian Cheese: environment and working conditions

    Energy Technology Data Exchange (ETDEWEB)

    Dioguardi, L.; Colombo, E.; Franzetti, L.

    2009-07-01

    In agro-food sector the structural features of working environments and consequently their hygienic conditions are of primary importance for a safe and quality food production and to ensure comfortable and ergonomic working conditions. In particular, as regards high-mountain dairy production, the environment is important because it can affect the development of typical microbial ecosystem. (Author)

  4. Two-branch Gas Experiments for Hot Gas Mixing of HTR-PM

    International Nuclear Information System (INIS)

    Zhou Yangping; Hao Pengefei; He Heng; Li Fu; Shi Lei

    2014-01-01

    A model experiment is proposed to investigate the hot gas mixing efficiency of HTR-PM reactor outlet. The test facility is introduced which is set at a scale of 1:2.5 comparing with the design of thermal mixing structure at HTR-PM reactor outlet. The test facility using air as its flow media includes inlet pipe system, electric heaters, main body of test facility, hot gas duct, exhaust pipe system and I&C system. Two-branch gas experiments are conducted on the test facility and the values of thermal-fluid parameters are collected and analyzed which include the temperature, pressure and velocity of the flow as well as the temperature of the tube wall. The analysis result shows the mixing efficiency is higher than the requirement of thermal mixing by steam generator even with conservative assumption which indicates that the design of hog gas mixing structure of HTR-PM fulfills the requirement for thermal mixing at two-branch working conditions. (author)

  5. Assessing the economic aspects of solar hot water production in Greece

    International Nuclear Information System (INIS)

    Haralambopoulos, D.; Kovras, H.

    1997-01-01

    The long-term performance of various systems was determined and the economic aspects of solar hot water production were investigated in this work. The effect of the collector inclination angle, collector area and storage volume was examined for all systems, and various climatic conditions and their payback period was calculated. It was found that the collector inclination angle does not have a significant effect on system performance. Large collector areas have a diminishing effect on the system's overall efficiency. The increase in storage volume has a detrimental effect for small daily load volumes, but a beneficial one when there is a large daily consumption. Solar energy was found to be truly competitive when the conventional fuel being substituted is electricity, and it should not replace diesel oil on pure economic grounds. Large daily load volumes and large collector areas are in general associated with shorter payback periods. Overall, the systems are oversized and are economically suitable for large daily hot water load volumes. (Author)

  6. Long working hours in Korea: results of the 2010 Working Conditions Survey.

    Science.gov (United States)

    Park, Jungsun; Kwon, Oh Jun; Kim, Yangho

    2012-01-01

    Long working hours adversely affect workers' safety and health. In 2004, Korea passed legislation limiting the working week to 40 h, to improve quality-of-life and to increase business competitiveness. In the present study, we explored the characteristics of work in Korea and compared our data of the second Korean Working Conditions Survey (KWCS) with those of the first KWCS. We found that the average number of hours worked weekly has been reduced but the proportions of workers who work for more than 48 h per week has increased over the 4 yr between the two Korean surveys in all categories studied (male, female, employee, self-employed, and employer). We also found that self-employed and employers work much longer hours than do employees, who are protected by the Labor Standards Act. This was particularly true in the accommodation and food service sectors. In conclusion, Korean workers work longer than do workers of EU countries. The use of average figures masks differences in the numbers of working hours among those engaged in various types of employment, or in certain work sectors. Therefore, the Korean government should not simply monitor reductions in average weekly working hours, but should identify employees working for over 60 h weekly, and reduce their working time.

  7. Analyzing Traffic Crash Severity in Work Zones under Different Light Conditions

    Directory of Open Access Journals (Sweden)

    Xinxin Wei

    2017-01-01

    Full Text Available Previous studies have investigated various factors that contribute to the severity of work zone crashes. However, little has been done on the specific effects of light conditions. Using the data from the Enhanced Tennessee Roadway Information Management System (E-TRIMS, crashes that occurred in the Tennessee work zones during 2003–2015 are categorized into three light conditions: daylight, dark-lighted, and dark-not-lighted. One commonly used decision tree method—Classification and Regression Trees (CART—is adopted to investigate the factors contributing to crash severity in highway work zones under these light conditions. The outcomes from the three decision trees with differing light conditions show significant differences in the ranking and importance of the factors considered in the study, thereby indicating the necessity of examining traffic crashes according to light conditions. By separately considering the crash characteristics under different light conditions, some new findings are obtained from this study. The study shows that an increase in the number of lanes increases the crash severity level in work zones during the day while decreasing the severity at night. Similarly, drugs and alcohol are found to increase the severity level significantly under the dark-not-lighted condition, while they have a limited influence under daylight and dark-lighted conditions.

  8. Fire preparedness measures in buildings with hot laboratories

    International Nuclear Information System (INIS)

    Oberlaender, B.C.

    2003-01-01

    Important hot laboratory safety issues are the general design/construction of the building with respect to fire, fire prevention, fire protection, administrative controls, and risk assessment. Within the network of the European Working Group Hot Laboratories and Remote Handling items concerning 'fire preparedness measures in hot laboratories' were screened and studied. Two questionnaires were sent to European hot laboratories; the first in November 2002 on 'fire preparedness measures, fire detection and fire suppression/extinguishing in lead shielded cells, concrete shielded cells' and the second in June 2003 on 'Fire preparedness measures in buildings with hot laboratories'. The questionnaires were filled in by a total of ten hot laboratories in seven European countries. On request of participants the answers were evaluated and 'anonymised' for presentation and discussion at the plenary meeting. The answers showed that many European hot laboratories are implementing improvements to their fire protection programmes to comply with more stringent requirements of the national authorities. The recommendations ('International guidelines for the fire protection of Nuclear Power Plants') given by the insurance pools are followed up with national variations. An ISO standard (ISO 17873) is in progress giving criteria for the design and the operation of ventilation systems as well as fire hazard management in nuclear installations others than reactors

  9. Sweatshop Working Conditions and Employee Welfare: Say It Ain’t Sew

    OpenAIRE

    J R Clark; Benjamin Powell

    2013-01-01

    This study surveys workers at two firms accused of being sweatshops by the National Labor Committee. We find that the wages and working conditions are superior to the workers’ prior employment. The mix of compensation between wages and working conditions reflects employee preferences and employees found their conditions less satisfactory when a firm capitulated to activist demands.

  10. Development of a pattern hot cell for production of injectable radiopharmaceuticals; Desenvolvimento de um modelo de cela para processamento de radiofarmacos injetaveis

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Fabio Eduardo de

    2010-07-01

    A controlled ambient should be established to the production/processing of materials susceptible to contamination, like injectable pharmaceuticals, in order to agree with normative and regulatory requirements. Considering medical but also toxic, radioactive and dangerous products, the ambient should work in special conditions to assure that the materials, which in same cases can be also volatile, do not escape to the external ambient, working in a selective, secure and controlled way. The conditions recommended by local and international rules in use, report an negative pressured ambient in relation to the adjacent areas. The technology related with the sizing of project to this kind of system is fully described in the literature, taking in account the rules that clearly describe the essential requirements. However, it is necessary to develop a controlled ambient for radiopharmaceutical production, in a way compatible with the concept of clean rooms and with the safety related to the manipulation of open radioactive wastes. In this work, some devices were created, methods and procedures were established making possible the classification of the ambient inside the hot cell, without physical barriers in the area, using ergonomic, flexible and practical conditions of work, that can results in the improvement of the productivity. The project resulted in the creation of a controlled ambient, in agreement with the normative requirements, using a pass through for entrance and exit of the materials, without compromise the internal air condition. The tight of the hot cell was obtained using doors with efficient sealing system and active joints. Tong manipulators were used to produce ergonomic and secure conditions, without compromise the internal conditions related to tight and classification in A and B grade, according to local and international rules. An efficient ventilation/exhaustion system was adopted to produce these results, composed by filters and special devices

  11. HOT 2011

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager 21 læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager 21 læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet....

  12. Impact of the crisis on working conditions in Europe

    OpenAIRE

    European Foundation for the Improvement of Living and Working Conditions

    2013-01-01

    The economic and financial crisis is affecting working conditions across EU Member States and Norway in different ways and scope. Yet the pattern is of less work, reduced overall working time, less overtime, rising job insecurity, less choice for workers, wage freezes and wage cuts. There is also greater work intensity, deterioration of work–life balance, increasing stress at work, greater risk of harassment/bullying, less absenteeism, growth in the informal economy and changes to migration p...

  13. Gender and Ageing at Work in Chile: Employment, Working Conditions, Work-Life Balance and Health of Men and Women in an Ageing Workforce.

    Science.gov (United States)

    Vives, Alejandra; Gray, Nora; González, Francisca; Molina, Agustín

    2018-04-18

    In Chile, working after retirement age has grown substantially over the last years. This, in addition to the country's current discussion about extending retirement age, motivates the need of generating evidence on the occupational health and safety of the working old, with a special focus on women, who are critically disadvantaged in Chile's labour market. The objective of this paper is to describe and compare the ageing workforce of women and men in Chile in terms of labour market participation, employment and working conditions, work-life balance, and health. The social determinants of health and employment sustainability frameworks guide this study. Cross-sectional data from three publicly available sources: the Chilean Labour Force Survey, NENE (2010); the first Chilean Employment and working conditions survey, ENETS (2009-2010) and the second National Health Survey, ENS (2009). Participation rates and employment conditions (NENE and ENETS), working conditions, occupational health and work-life balance (ENETS) and chronic health conditions (ENS) were described by 5-year age groups separately for women and men. Descriptions cover all age groups in order to identify trends and patterns characteristic of older workers. Rates of occupation decrease sharply after age 54 in women and 59 in men. Ageing women and men who continue to work are more likely to be in own-account (self-employed) work than younger workers; in the case of women, in households as domestic workers, and men, in agriculture. Social protection and workplace rights are markedly reduced in older workers. Part-time work increases from the age of 50 onwards, especially among women, but average working hours do not decrease under 30 h a week for either women or men. Interestingly, between ages 60 and 64, there is a peak increase of day and night shift-work among women, which co-occurs with a peak in domestic work, possibly corresponding to women working as caretakers of elderly people. Several

  14. Hot-wall corrosion testing of simulated high level nuclear waste

    International Nuclear Information System (INIS)

    Chandler, G.T.; Zapp, P.E.; Mickalonis, J.I.

    1995-01-01

    Three materials of construction for steam tubes used in the evaporation of high level radioactive waste were tested under heat flux conditions, referred to as hot-wall tests. The materials were type 304L stainless steel alloy C276, and alloy G3. Non-radioactive acidic and alkaline salt solutions containing halides and mercury simulated different high level waste solutions stored or processed at the United States Department of Energy's Savannah River Site. Alloy C276 was also tested for corrosion susceptibility under steady-state conditions. The nickel-based alloys C276 and G3 exhibited excellent corrosion resistance under the conditions studied. Alloy C276 was not susceptible to localized corrosion and had a corrosion rate of 0.01 mpy (0.25 μm/y) when exposed to acidic waste sludge and precipitate slurry at a hot-wall temperature of 150 degrees C. Type 304L was susceptible to localized corrosion under the same conditions. Alloy G3 had a corrosion rate of 0.1 mpy (2.5 μm/y) when exposed to caustic high level waste evaporator solution at a hot-wall temperature of 220 degrees C compared to 1.1 mpy (28.0 μ/y) for type 304L. Under extreme caustic conditions (45 weight percent sodium hydroxide) G3 had a corrosion rate of 0.1 mpy (2.5 μm/y) at a hot-wall temperature of 180 degrees C while type 304L had a high corrosion rate of 69.4 mpy (1.8 mm/y)

  15. The effects of annealing temperature and cooling rate on carbide precipitation behavior in H13 hot-work tool steel

    International Nuclear Information System (INIS)

    Kang, Minwoo; Park, Gyujin; Jung, Jae-Gil; Kim, Byung-Hoon; Lee, Young-Kook

    2015-01-01

    Highlights: • Unexpected Mo carbides formed during slow cooling from low annealing temperatures. • Mo carbides formed during the migration of Mo for a transition of Cr-rich carbide. • Mo carbides were precipitated at the boundaries of M 7 C 3 carbides and ferrite grains. • Annealing conditions for the precipitation of Mo carbides were discussed. - Abstract: The precipitation behavior of H13 hot-work tool steel was investigated as a function of both annealing temperature and cooling rate through thermodynamic calculations and microstructural analyses using transmission and scanning electron microscope and a dilatometer. The V-rich MC carbide and Cr-rich M 7 C 3 and M 23 C 6 carbides were observed in all annealed specimens regardless of annealing and cooling conditions, as expected from an equilibrium phase diagram of the steel used. However, Mo-rich M 2 C and M 6 C carbides were unexpectedly precipitated at a temperature between 675 °C and 700 °C during slow cooling at a rate of below 0.01 °C/s from the annealing temperatures of 830 °C and below. The solubility of Mo in both M 7 C 3 and ferrite reduces with decreasing temperature during cooling. Mo atoms diffuse out of both M 7 C 3 and ferrite, and accumulate locally at the interface between M 7 C 3 and ferrite. Mo carbides were form at the interface of M 7 C 3 carbides during the transition of Cr-rich M 7 C 3 to stable M 23 C 6

  16. Laser Cladding of CPM Tool Steels on Hardened H13 Hot-Work Steel for Low-Cost High-Performance Automotive Tooling

    Science.gov (United States)

    Chen, J.; Xue, L.

    2012-06-01

    This paper summarizes our research on laser cladding of high-vanadium CPM® tool steels (3V, 9V, and 15V) onto the surfaces of low-cost hardened H13 hot-work tool steel to substantially enhance resistance against abrasive wear. The results provide great potential for fabricating high-performance automotive tooling (including molds and dies) at affordable cost. The microstructure and hardness development of the laser-clad tool steels so obtained are presented as well.

  17. 29 CFR 1960.28 - Employee reports of unsafe or unhealthful working conditions.

    Science.gov (United States)

    2010-07-01

    ... make a report of the unsafe or unhealthful working condition to an appropriate agency safety and health... conditions, and within 20 working days for other than serious safety and health conditions. However, an... conditions. 1960.28 Section 1960.28 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND...

  18. Physical working conditions as covered in European monitoring questionnaires

    NARCIS (Netherlands)

    Tynes, T.; Aagestad, C.; Vester Thorsen, S.; Andersen, L.L.; Perkio-Makela, M.; García, F.J.P.; Blanco, L..; Vermeylen, G.; Parent-Thirion, A.; Hooftman, W.; Houtman, I.L.D.; Liebers, F.; Burr, H.; Formazin, M.

    2017-01-01

    Background. The prevalence of workers with demanding physical working conditions in the European work force remains high, and occupational physical exposures are considered important risk factors for musculoskeletal disorders (MSD), a major burden for both workers and society. Exposures to physical

  19. Crisis in the health sector: Impact on nurses' working conditions.

    Science.gov (United States)

    Granero-Lázaro, Alberto; Blanch-Ribas, Josep M; Roldán-Merino, Juan Francisco; Torralbas-Ortega, Jordi; Escayola-Maranges, Ana María

    In a context of economic crisis and policies to reduce the public deficit, the budgets of the Catalan Health Institute (CHI) were cut by 15.33% between 2010 and 2014. To assess the perceived impact on nurses' work conditions of measures to contain health spending. The study design was descriptive and transversal. A sample of 1,760 nurses from the province of Barcelona answered a questionnaire on the perceived impact of health spending containment measures implemented in their workplace during the early years of the crisis. Among the main aspects of the perceived impact of these measures, 86.6% of the nurses identified a pay cut and an increase in the following relevant parameters of their working conditions: number of hours worked (66.7%), final ratio of treated patients (35.2%), task complexity and workload (75.3%), rotation through various departments (31.5%), work shifts (21.4%) or work areas (23.4%), job insecurity (58.4%) and loss of employment by dismissal (6.6%) or non-renewal of contract (9%). The perceived impact of the crisis showed a triple negative component: Pay cut, work overload and job insecurity. As a combined effect of this multiple trend, the nurses acknowledged a deterioration in their working conditions and quality of working life. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  20. Equivalent circuit-level model of quantum cascade lasers with integrated hot-electron and hot-phonon effects

    Science.gov (United States)

    Yousefvand, H. R.

    2017-12-01

    We report a study of the effects of hot-electron and hot-phonon dynamics on the output characteristics of quantum cascade lasers (QCLs) using an equivalent circuit-level model. The model is developed from the energy balance equation to adopt the electron temperature in the active region levels, the heat transfer equation to include the lattice temperature, the nonequilibrium phonon rate to account for the hot phonon dynamics and simplified two-level rate equations to incorporate the carrier and photon dynamics in the active region. This technique simplifies the description of the electron-phonon interaction in QCLs far from the equilibrium condition. Using the presented model, the steady and transient responses of the QCLs for a wide range of sink temperatures (80 to 320 K) are investigated and analysed. The model enables us to explain the operating characteristics found in QCLs. This predictive model is expected to be applicable to all QCL material systems operating in pulsed and cw regimes.

  1. Effects of Niobium Microalloying on Microstructure and Properties of Hot-Dip Galvanized Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Mohrbacher, Hardy [NiobelCon bvba, Brussels (Belgium)

    2010-04-15

    Niobium microalloying is effective in hot-rolled and cold-rolled steels by providing a fine-grained microstructure resulting in increased strength. To optimize the strengthening effect, alloy design and hot-rolling conditions have to be adapted. As a key issue the dissolution and precipitation characteristics of Nb are discussed in particular with regard to the run-out table conditions. It is then considered how the hot-rolled microstructure and the solute state of Nb interact with the hot-dip galvanizing cycle. The adjusted conditions allow controlling the morphology and distribution of phases in the cold-rolled annealed material. Additional precipitation hardening can be achieved as well. The derived options can be readily applied to produce conventional HSLA and IF high strength steels as well as to modem multiphase steels. It will be explained how important application properties such as strength, elongation, bendability, weldability and delayed cracking resistance can be influenced in a controlled and favorable way. Examples of practical relevance and experience are given.

  2. Working Conditions-Aware Fault Injection Technique

    OpenAIRE

    Alouani , Ihsen; Niar , Smail; Jemai , Mohamed; Kuradi , Fadi; Abid , Mohamed

    2012-01-01

    International audience; With new integration rates, the circuits sensitivity to environmental and working conditions has increased dramatically. Thus, presenting reliable, less consuming energy and error resilient architectures is being one of the major problems to deal with. Besides, evaluating robustness and effectiveness of the proposed architectures is also an urgent need. In this paper, we present an extension of SimpleScalar simulation tool having the ability to inject faults in a given...

  3. Impact of chlorinated disinfection on copper corrosion in hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Montes, J. Castillo [Centre Scientifique et Technique du Bâtiment Nantes, 11 rue Henri Picherit, BP 82341, 44323 Nantes Cedex 03 (France); Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Hamdani, F. [Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Creus, J., E-mail: jcreus@univ-lr.fr [Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Touzain, S. [Laboratoire des Sciences de l’Ingénieur pour l’Environnement, UMR-CNRS 7356, Université de La Rochelle, Avenue Michel Crépeau, 17042 La Rochelle Cedex 1 (France); Correc, O. [Centre Scientifique et Technique du Bâtiment Nantes, 11 rue Henri Picherit, BP 82341, 44323 Nantes Cedex 03 (France)

    2014-09-30

    Highlights: • Impact of disinfectant treatment on the durability of copper pipes. • Synergy between disinfectant concentration and temperature. • Pitting corrosion of copper associated to the corrosion products formation on copper. - Abstract: In France, hot water quality control inside buildings is occasionally ensured by disinfection treatments using temperature increases or addition of sodium hypochlorite (between 0.5 ppm and 1 ppm residual free chlorine). This disinfectant is a strong oxidiser and it could interact with metallic pipes usually used in hot water systems. This work deals with the study of the impact of these treatments on the durability of copper pipes. The objective of this work was to investigate the influence of sodium hypochlorite concentration and temperature on the copper corrosion mechanism. Copper samples were tested under dynamic and static conditions of ageing with sodium hypochlorite solutions ranging from 0 to 100 ppm with temperature at 50 °C and 70 °C. The efficiency of a corrosion inhibitor was investigated in dynamic conditions. Visual observations and analytical analyses of the internal surface of samples was studied at different ageing duration. Corrosion products were characterised by X-ray diffraction and Raman spectroscopy. Temperature and disinfectant were found to considerably affect the copper corrosion mechanism. Surprisingly, the corrosiveness of the solution was higher at lower temperatures. The temperature influences the nature of corrosion products. The protection efficiency is then strongly depend on the nature of the corrosion products formed at the surface of copper samples exposed to the aggressive solutions containing different concentration of disinfectant.

  4. Effect of unit size on thermal fatigue behavior of hot work steel repaired by a biomimetic laser remelting process

    Science.gov (United States)

    Cong, Dalong; Li, Zhongsheng; He, Qingbing; Chen, Dajun; Chen, Hanbin; Yang, Jiuzhou; Zhang, Peng; Zhou, Hong

    2018-01-01

    AISI H13 hot work steel with fatigue cracks was repaired by a biomimetic laser remelting (BLR) process in the form of lattice units with different sizes. Detailed microstructural studies and microhardness tests were carried out on the units. Studies revealed a mixed microstructure containing martensite, retained austenite and carbide particles with ultrafine grain size in units. BLR samples with defect-free units exhibited superior thermal fatigue resistance due to microstructure strengthening, and mechanisms of crack tip blunting and blocking. In addition, effects of unit size on thermal fatigue resistance of BLR samples were discussed.

  5. Development of hot and cool executive functions in middle childhood: Three-year growth curves of decision making and working memory updating.

    Science.gov (United States)

    Lensing, Nele; Elsner, Birgit

    2018-05-07

    Although middle childhood is an important period for the development of hot and cool executive functions (EFs), longitudinal studies investigating trajectories of childhood EF development are still limited and little is known about predictors for individual developmental trajectories. The current study examined the development of two typical facets of cool and hot EFs over a 3-year period during middle childhood, comparing a younger cohort (6- and 7-year-olds at the first wave [T1]; n = 621) and an older cohort (8- and 9-year-olds at T1; n = 975) of children. "Cool" working memory updating (WM) was assessed using a backward digit span task, and "hot" decision making (DM) was assessed using a child variant of the Iowa Gambling Task. Linear latent growth curve analyses revealed evidence for developmental growth as well as interindividual variance in the initial level and rate of change in both EF facets. Initial level of WM was positively associated with age (both between and within cohorts), socioeconomic status, verbal ability, and processing speed, whereas initial levels of DM were, in addition to a (potentially age-related) cohort effect, exclusively predicted by gender, with boys outperforming girls. None of the variables predicted the rate of change, that is, the developmental trajectories. However, younger children, as compared with older children, had slightly steeper WM growth curves over time, hinting at a leveling off in the development of WM during middle childhood. In sum, these data add important evidence to the understanding of hot and cool EF development during middle childhood. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Decoupling dehumidification and cooling for energy saving and desirable space air conditions in hot and humid Hong Kong

    International Nuclear Information System (INIS)

    Lee, W.L.; Chen Hua; Leung, Y.C.; Zhang, Y.

    2012-01-01

    Highlights: ► The combined use of dedicated ventilation and dry cooling (DCDV) system was investigated. ► Investigations were based actual equipment performance data and realistic building and system characteristics. ► DCDV system could save 54% of the annual energy use for air-conditioning. ► DCDV system could better achieve the desired space air conditions. ► DCDV system could decouple dehumidification and cooling. - Abstract: The combined use of dedicated outdoor air ventilation (DV) and dry cooling (DC) air-conditioning system to decouple sensible and latent cooling for desirable space air conditions, better indoor air quality, and energy efficiency is proposed for hot and humid climates like Hong Kong. In this study, the performance and energy saving potential of DCDV system in comparison to conventional systems (constant air volume (CAV) system with and without reheat) for air conditioning of a typical office building in Hong Kong are evaluated. Through hour-by-hour simulations, using actual equipment performance data and realistic building and system characteristics, the cooling load profile, resultant indoor air conditions, condensation at the DC coil, and energy consumptions are calculated and analyzed. The results indicate that with the use of DCDV system, the desirable indoor conditions could be achieved and the annual energy use could be reduced by 54% over CAV system with reheat. The condensate-free characteristic at the DC coil to reduce risk of catching disease could also be realized.

  7. IS WORK-FAMILY CONFLICT A MULTILEVEL STRESSOR LINKING JOB CONDITIONS TO MENTAL HEALTH? EVIDENCE FROM THE WORK, FAMILY AND HEALTH NETWORK.

    Science.gov (United States)

    Moen, Phyllis; Kaduk, Anne; Kossek, Ellen Ernst; Hammer, Leslie; Buxton, Orfeu M; O'Donnell, Emily; Almeida, David; Fox, Kimberly; Tranby, Eric; Oakes, J Michael; Casper, Lynne

    Most research on the work conditions and family responsibilities associated with work-family conflict and other measures of mental health uses the individual employee as the unit of analysis. We argue that work conditions are both individual psychosocial assessments and objective characteristics of the proximal work environment, necessitating multilevel analyses of both individual- and team-level work conditions on mental health. This study uses multilevel data on 748 high-tech professionals in 120 teams to investigate relationships between team- and individual-level job conditions, work-family conflict, and four mental health outcomes (job satisfaction, emotional exhaustion, perceived stress, and psychological distress). We find that work-to-family conflict is socially patterned across teams, as are job satisfaction and emotional exhaustion. Team-level job conditions predict team-level outcomes, while individuals' perceptions of their job conditions are better predictors of individuals' work-to-family conflict and mental health. Work-to-family conflict operates as a partial mediator between job demands and mental health outcomes. Our findings suggest that organizational leaders concerned about presenteeism, sickness absences, and productivity would do well to focus on changing job conditions in ways that reduce job demands and work-to-family conflict in order to promote employees' mental health. We show that both work-to-family conflict and job conditions can be fruitfully framed as team characteristics, shared appraisals held in common by team members. This challenges the framing of work-to-family conflict as a "private trouble" and provides support for work-to-family conflict as a structural mismatch grounded in the social and temporal organization of work.

  8. Thermodynamic performance analysis of ramjet engine at wide working conditions

    Science.gov (United States)

    Ou, Min; Yan, Li; Tang, Jing-feng; Huang, Wei; Chen, Xiao-qian

    2017-03-01

    Although ramjet has the advantages of high-speed flying and higher specific impulse, the performance parameters will decline seriously with the increase of flight Mach number and flight height. Therefore, the investigation on the thermodynamic performance of ramjet is very crucial for broadening the working range. In the current study, a typical ramjet model has been employed to investigate the performance characteristics at wide working conditions. First of all, the compression characteristic analysis is carried out based on the Brayton cycle. The obtained results show that the specific cross-section area (A2 and A5) and the air-fuel ratio (f) have a great influence on the ramjet performance indexes. Secondly, the thermodynamic calculation process of ramjet is given from the view of the pneumatic thermal analysis. Then, the variable trends of the ramjet performance indexes with the flow conditions, the air-fuel ratio (f), the specific cross-sectional area (A2 and A5) under the fixed operating condition, equipotential dynamic pressure condition and variable dynamic pressure condition have been discussed. Finally, the optimum value of the specific cross-sectional area (A5) and the air-fuel ratio (f) of the ramjet model at a fixed work condition (Ma=3.5, H=12 km) are obtained.

  9. Alpha-Gamma Hot-Cell Facility at Argonne National Laboratory East

    International Nuclear Information System (INIS)

    Neimark, L.A.; Jackson, W.D.; Donahue, D.A.

    1979-01-01

    The Alpha-Gamma Hot-Cell Facility has been in operation at Argonne National Laboratory East (ANL-E) for 15 years. The facility was designed for plutonium research in support of ANL's LMFBR program. The facility consists of a kilocurie, nitrogen-atmosphere alpha-gamma hot cell and supporting laboratories. Modifications to the facility and its equipment have been made over the years as the workload and nature of the work changed. These modifications included inerting the entire hot cell, adding four work stations, modifying in-loading procedures and examination equipment to handle longer test articles, and changing to a new sodium-vapor lighting system. Future upgrading includes the addition of a decontamination and repair facility, use of radio-controlled transfer carts, refurbishment of the zinc bromide windows, and the installation of an Auger microprobe

  10. Experimental optimization of temperature distribution in the hot-gas duct through the installation of internals in the hot-gas plenum of a high-temperature reactor

    International Nuclear Information System (INIS)

    Henssen, J.; Mauersberger, R.

    1990-01-01

    The flow conditions in the hot-gas plenum and in the adjacent hot-gas ducts and hot-gas pipes for the high-temperature reactor project PNP-1000 (nuclear process heat project for 1000 MW thermal output) have been examined experimentally. The experiments were performed in a closed loop in which the flow model to be analyzed, representing a 60deg sector of the core bottom of the PNP-1000 with connecting hot-gas piping and diverting arrangements, was installed. The model scale was approx. 1:5.6. The temperature and flow velocity distribution in the hot-gas duct was registered by means of 14 dual hot-wire flowmeters. Through structural changes and/or the installation of internals into the hot-gas plenum of the core bottom offering little flow resistance coolant gas temperature differentials produced in the core could be reduced to such an extent that a degree of mixture amounting to over 80% was achieved at the entrance of the connected heat exchanger systems. Thereby the desired goal of an adequate degree of mixture of the hot gas involving an acceptable pressure loss was reached. (orig.)

  11. Tribological Behavior of Laser Textured Hot Stamping Dies

    Directory of Open Access Journals (Sweden)

    Andre Shihomatsu

    2016-01-01

    Full Text Available Hot stamping of high strength steels has been continuously developed in the automotive industry to improve mechanical properties and surface quality of stamped components. One of the main challenges faced by researchers and technicians is to improve stamping dies lifetime by reducing the wear caused by high pressures and temperatures present during the process. This paper analyzes the laser texturing of hot stamping dies and discusses how different surfaces textures influence the lubrication and wear mechanisms. To this purpose, experimental tests and numerical simulation were carried out to define the die region to be texturized and to characterize the textured surface topography before and after hot stamping tests with a 3D surface profilometer and scanning electron microscopy. Results showed that laser texturing influences the lubrication at the interface die-hot sheet and improves die lifetime. In this work, the best texture presented dimples with the highest diameter, depth, and spacing, with the surface topography and dimples morphology practically preserved after the hot stamping tests.

  12. HOT 2014

    DEFF Research Database (Denmark)

    Lund, Henriette

    Undersøgelse af, hvad der er hot - og hvad der burde være hot på læseområdet med 21 læsekyndige. Undersøgelsen er gennemført siden 2010. HOT-undersøgelsen er foretaget af Nationalt Videncenter for Læsning - Professionshøjskolerne i samarb. med Dansklærerforeningen...

  13. Remarks on theoretical hot-atom chemistry

    International Nuclear Information System (INIS)

    Inokuti, Mitio

    1993-01-01

    The publication of the 'Handbook of Hot Atom Chemistry', following the earlier volume 'Recent Trend and Application', was a major milestone in physical chemistry. Theoretical treatments of hot atom chemistry must address two classes of problems. The first class concerns the individual collisions of hot atoms with other atoms or molecules. The second class concerns the description of the consequences of the many collisions of hot atoms and their chemical environment. Most of the remarks pertain to the problems of the first class. The central issue is the adiabaticity of nuclear motions versus electronic motions. To be precise, any atomic core motion should be mentioned rather than pure nuclear motion, because tightly bound core electrons are largely irrelevant to the chemistry. When nuclear motions are sufficiently slow, or for other reasons that can be regarded as adiabatic, the collision problem is basically straightforward, therefore, interatomic and intermolecular forces can be assumed, and their consequences for nuclear motions are calculable in principle. In the case of non-adiabaticity being important, much more difficult problems arise, and it is briefly discussed, and the work by Phelps is cited. (K.I.)

  14. Volcanic Gases and Hot Spring Water to Evaluate the Volcanic Activity of the Mt. Baekdusan

    Science.gov (United States)

    Yun, S. H.; Lee, S.; Chang, C.

    2017-12-01

    This study performed the analysis on the volcanic gases and hot spring waters from the Julong hot spring at Mt. Baekdu, also known as Changbaishan on the North Korea(DPRK)-China border, during the period from July 2015 to August 2016. Also, we confirmed the errors that HCO3- concentrations of hot spring waters in the previous study (Lee et al. 2014) and tried to improve the problem. Dissolved CO2 in hot spring waters was analyzed using gas chromatograph in Lee et al.(2014). Improving this, from 2015, we used TOC-IC to analysis dissolved CO2. Also, we analyzed the Na2CO3 standard solutions of different concentrations using GC, and confirmed the correlation between the analytical concentrations and the real concentrations. However, because the analytical results of the Julong hot spring water were in discord with the estimated values based on this correlation, we can't estimate the HCO3-concentrations of 2014 samples. During the period of study, CO2/CH4 ratios in volcanic gases are gradually decreased, and this can be interpreted in two different ways. The first interpretation is that the conditions inside the volcanic edifice are changing into more reduction condition, and carbon in volcanic gases become more favorable to distribute into CH4 or CO than CO2. The second interpretation is that the interaction between volcanic gases and water becomes greater than past, and the concentrations of CO2which have much higher solubility in water decreased, relatively. In general, the effect of scrubbing of volcanic gas is strengthened during the quiet periods of volcanic activity rather than active periods. Meanwhile, the analysis of hot spring waters was done on the anion of acidic gases species, the major cations, and some trace elements (As, Cd, Re).This work was funded by the Korea Meteorological Administration Research and Development Program under Grant KMIPA 2015-3060.

  15. Working conditions in mid-life and mental health in older ages.

    Science.gov (United States)

    Wahrendorf, Morten; Blane, David; Bartley, Mel; Dragano, Nico; Siegrist, Johannes

    2013-03-01

    This article illustrates the importance of previous working conditions during mid-life (between 40 and 55) for mental health among older retired men and women (60 or older) across 13 European countries. We link information on health from the second wave (2006-2007) of the Survey of Health, Ageing and Retirement in Europe (SHARE) with information on respondents' working life collected retrospectively in the SHARELIFE interview (2008-2009). To measure working conditions, we rely on core assumptions of existing theoretical models of work stress (the demand-control-support and the effort-reward imbalance model) and distinguish four types of unhealthy working conditions: (1) a stressful psychosocial work environment (as assessed by the two work stress models) (2) a disadvantaged occupational position throughout the whole period of mid-life, (3) experience of involuntary job loss, and (4) exposure to job instability. Health after labour market exit is measured using depressive symptoms, as measured by the EURO-D depression scale. Main results show that men and women who experienced psychosocial stress at work or had low occupational positions during mid-life had significantly higher probabilities of high depressive symptoms during retirement. Additionally, men with unstable working careers and an involuntary job loss were at higher risks to report high depressive symptoms in later life. These associations remain significant after controlling for workers' health and social position prior mid-life. These findings support the assumption that mental health of retirees who experienced poor working conditions during mid-life is impaired. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. [Arduous working conditions for beginners: when workplace prevention becomes an economic risk].

    Science.gov (United States)

    Latil, François

    2015-01-01

    The French law of 20.01.2014 recently instituted an arduous working conditions allowance. This innovated legislation is designed to improve the status of workers subject to arduous working conditions either by allowing lighter work schedules or job reclassification or early retirement. The impact of arduous working conditions on health has been clearly established, but no consensual solution has yet been proposed. Life expectancy without disability can differ by as much as 9 years between higher executives and manual workers, but the proposed solutions comprise a multitude of perverse effects. Workers may benefit from maintaining their arduous working conditions in order to preserve their right to early retirement. Companies do not necessarily have the desire or the resources to invest in prevention, which is the only consensually accepted effective measure, if they are also required to finance both training and retirement. In particular, management of the arduous working conditions allowance is very complex and entirely financed by companies. Consequently, company productivity can be impacted, leading to transfers of company headquarters, outsourcing to interim workers, replacement of jobs by automation. Unemployment could be the big winner of this conflict. Politically, arduous working conditions allowance appears to be very difficult to put into practice and can be considered to be more a promise by the government to the left and to the trade unions.

  17. Medical Services at an International Summer Camp Event Under Hot and Humid Conditions: Experiences From the 23rd World Scout Jamboree, Japan.

    Science.gov (United States)

    Watanabe, Takemasa; Mizutani, Keiji; Iwai, Toshiyasu; Nakashima, Hiroshi

    2018-06-01

    The 23rd World Scout Jamboree (WSJ) was a 10-day summer camp held in Japan in 2015 under hot and humid conditions. The attendees comprised 33,628 people from 155 countries and territories. The aim of this study was to examine the provision of medical services under such conditions and to identify preventive factors for major diseases among long-term campers. Data were obtained from WSJ medical center records and examined to clarify the effects of age, sex, and period on visit frequencies and rates. Medical records from 3215 patients were examined. Daytime temperatures were 31.5±3.2°C and relative humidity was 61±13% (mean±SD). The initial visit rates among scouts and adults were 72.2 and 77.2 per 1000 persons, respectively. No significant age difference was observed in the initial visit rate; however, it was significantly higher among female patients than male patients. Significant differences were also seen in the adjusted odds ratios by age, sex, and period for disease distributions of initial visit frequencies. In addition, a higher initial visit frequency for heat strain-related diseases was seen among the scouts. Initial visit frequencies for heatstroke and/or dehydration increased just after opening day and persisted until closing day. Our findings suggest the importance of taking effective countermeasures against heat strain, fatigue, and unsanitary conditions at the WSJ. Medical services staff should take attendees' age, sex, and period into consideration to prevent heat strain-related diseases during such camps under hot and humid conditions. Copyright © 2018 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  18. Characterization of hot dense plasma with plasma parameters

    Science.gov (United States)

    Singh, Narendra; Goyal, Arun; Chaurasia, S.

    2018-05-01

    Characterization of hot dense plasma (HDP) with its parameters temperature, electron density, skin depth, plasma frequency is demonstrated in this work. The dependence of HDP parameters on temperature and electron density is discussed. The ratio of the intensities of spectral lines within HDP is calculated as a function of electron temperature. The condition of weakly coupled for HDP is verified by calculating coupling constant. Additionally, atomic data such as transition wavelength, excitation energies, line strength, etc. are obtained for Be-like ions on the basis of MCDHF method. In atomic data calculations configuration interaction and relativistic effects QED and Breit corrections are newly included for HDP characterization and this is first result of HDP parameters from extreme ultraviolet (EUV) radiations.

  19. A quantitative sensitivity analysis on the behaviour of common thermal indices under hot and windy conditions in Doha, Qatar

    Science.gov (United States)

    Fröhlich, Dominik; Matzarakis, Andreas

    2016-04-01

    Human thermal perception is best described through thermal indices. The most popular thermal indices applied in human bioclimatology are the perceived temperature (PT), the Universal Thermal Climate Index (UTCI), and the physiologically equivalent temperature (PET). They are analysed focusing on their sensitivity to single meteorological input parameters under the hot and windy meteorological conditions observed in Doha, Qatar. It can be noted, that the results for the three indices are distributed quite differently. Furthermore, they respond quite differently to modifications in the input conditions. All of them show particular limitations and shortcomings that have to be considered and discussed. While the results for PT are unevenly distributed, UTCI shows limitations concerning the input data accepted. PET seems to respond insufficiently to changes in vapour pressure. The indices should therefore be improved to be valid for several kinds of climates.

  20. Working conditions, job dissatisfaction and smoking behaviours among French clerks and manual workers.

    Science.gov (United States)

    Peretti-Watel, Patrick; Constance, Jean; Seror, Valérie; Beck, François

    2009-03-01

    To study the relationships between working conditions, job dissatisfaction and smoking behaviors among clerks and manual workers. We used data from the French Health Barometer, a cross-sectional telephone survey conducted among a national random sample (N = 4825). Regarding working conditions, the questionnaire dealt with reported job satisfaction, psychological demands and mental workload, physical demands, latitude decision and work schedule. Manual workers and clerks who reported strong dissatisfaction toward unhealthy working conditions also reported more frequently current smoking, tobacco dependence, potential alcohol dependence and perceived stress. After adjusting for socio-demographic confounders, perceived working conditions and job dissatisfaction remained correlated with smoking and tobacco dependence. Poor working conditions may heavily contribute to health inequalities, as they are likely to fuel both stress and unhealthy behaviors, which combine to increase morbidity and mortality.

  1. [Working conditions, living conditions and physical health problems declared among penitentiary administration personnel in France].

    Science.gov (United States)

    Goldberg, P; Landre, M F; David, S; Goldberg, M; Dassa, S; Marne, M J

    1996-06-01

    A cross-sectional epidemiological survey was conducted among prison staff in France to investigate the relationships between working conditions and health. The sample included men and women 20 to 64 years old belonging to all categories of prison personnel: prison guards, administrative staff, socioeducational workers, technicians, health care workers, and managers (n = 4587, response rate 45.7%). A mailed self-administered questionnaire was used to assess sociodemographic characteristics, working conditions, and physical and mental disorders. Multiple logistic regression analyses were conducted to determine the effects of working conditions and social relationships on health of prison staff. However, the results reported here only concern 17 health disorders: body mass index, sick leave, medication use, accidents, digestive disorders, lower extremities and back disorders, hypertension, hemorrhoids, arthritis, skin disorders, urinary infections, chronic bronchitis, cholesterol, gastric ulcer, respiratory infections, ocular disorders. The living non professional conditions mostly associated with health disorders were financial difficulties (OR: 1.9 for digestive disorders, 1.8 for gastric ulcer, 1.7 for medication use) and irregularity of meals (OR = 1.5 for digestive disorders, and hypertension). In the occupational environment, the factors most associated with health disorders are seniority (OR = 4.2 for arthritis, 2.3 for cholesterol) and constraints (OR = 1.7 for lower extremities disorders). In spite of some limits associated to this kind of study, relationships between occupational and non occupational factors and physical health conditions were observed; the results also pointed out the protective role of the social relationships for health conditions.

  2. High-power UV-LED degradation: Continuous and cycled working condition influence

    Science.gov (United States)

    Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

    2015-09-01

    High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

  3. Investigation of hot ductility in Al-killed boron steels

    International Nuclear Information System (INIS)

    Chown, L.H.; Cornish, L.A.

    2008-01-01

    The influence of boron to nitrogen ratio, strain rate and cooling rate on hot ductility of aluminium-killed, low carbon, boron microalloyed steel was investigated. Hot tensile testing was performed on steel samples reheated in argon to 1300 deg. C, cooled at rates of 0.3, 1.2 and 3.0 deg. C s -1 to temperatures in the range 750-1050 deg. C, and then strained to failure at initial strain rates of 1 x 10 -4 or 1 x 10 -3 s -1 . It was found that the steel with a B:N ratio of 0.19 showed deep hot ductility troughs for all tested conditions; the steel with a B:N ratio of 0.47 showed a deep ductility trough for a high cooling rate of 3.0 deg. C s -1 and the steel with a near-stoichiometric B:N ratio of 0.75 showed no ductility troughs for the tested conditions. The ductility troughs extended from ∼900 deg. C (near the Ae 3 temperature) to ∼1000 or 1050 deg. C in the single-phase austenite region. The proposed mechanism of hot ductility improvement with increase in B:N ratio in these steels is that the B removes N from solution, thus reducing the strain-induced precipitation of AlN. Additionally, BN co-precipitates with sulphides, preventing precipitation of fine MnS, CuS and FeS, and forming large, complex precipitates that have no effect on hot ductility

  4. Improving significantly the failure strain and work hardening response of LPSO-strengthened Mg-Y-Zn-Al alloy via hot extrusion speed control

    Science.gov (United States)

    Tan, Xinghe; Chee, Winston; Chan, Jimmy; Kwok, Richard; Gupta, Manoj

    2017-07-01

    The effect of hot extrusion speed on the microstructure and mechanical properties of MgY1.06Zn0.76Al0.42 (at%) alloy strengthened by the novel long-period stacking ordered (LPSO) phase was systematically investigated. Increase in the speed of extrusion accelerated dynamic recrystallization of α-Mg via particle-stimulated nucleation and grain growth in the alloy. The intensive recrystallization and grain growth events weakened the conventional basal texture and Hall-Petch strengthening in the alloy which led to significant improvement in its failure strain from 4.9% to 19.6%. The critical strengthening contribution from LPSO phase known for attributing high strength to the alloy was observed to be greatly undermined by the parallel competition from texture weakening and the adverse Hall-Petch effect when the alloy was extruded at higher speed. Absence of work hardening interestingly observed in the alloy extruded at lower speed was discussed in terms of its ultra-fine grained microstructure which promoted the condition of steady-state defect density in the alloy; where dislocation annihilation balances out the generation of new dislocations during plastic deformation. One approach to improve work hardening response of the alloy to prevent unstable deformation and abrupt failure in service is to increase the grain diameter in the alloy by judiciously increasing the extrusion speed.

  5. Impacts of Implosion Asymmetry And Hot Spot Shape On Ignition Capsules

    Science.gov (United States)

    Cheng, Baolian; Kwan, Thomas J. T.; Wang, Yi-Ming; Yi, S. Austin; Batha, Steve

    2017-10-01

    Implosion symmetry plays a critical role in achieving high areal density and internal energy at stagnation during hot spot formation in ICF capsules. Asymmetry causes hot spot irregularity and stagnation de-synchronization that results in lower temperatures and areal densities of the hot fuel. These degradations significantly affect the alpha heating process in the DT fuel as well as on the thermonuclear performance of the capsules. In this work, we explore the physical factors determining the shape of the hot spot late in the implosion and the effects of shape on Î+/-particle transport. We extend our ignition theory [1-4] to include the hot spot shape and quantify the effects of the implosion asymmetry on both the ignition criterion and capsule performance. We validate our theory with the NIF existing experimental data Our theory shows that the ignition criterion becomes more restrictive with the deformation of the hot spot. Through comparison with the NIF data, we demonstrate that the shape effects on the capsules' performance become more explicit as the self-heating and yield of the capsules increases. The degradation of the thermonuclear burn by the hot spot shape for high yield shots to date can be as high as 20%. Our theory is in good agreement with the NIF data. This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.

  6. IS WORK-FAMILY CONFLICT A MULTILEVEL STRESSOR LINKING JOB CONDITIONS TO MENTAL HEALTH? EVIDENCE FROM THE WORK, FAMILY AND HEALTH NETWORK

    Science.gov (United States)

    Moen, Phyllis; Kaduk, Anne; Kossek, Ellen Ernst; Hammer, Leslie; Buxton, Orfeu M.; O’Donnell, Emily; Almeida, David; Fox, Kimberly; Tranby, Eric; Oakes, J. Michael; Casper, Lynne

    2015-01-01

    Purpose Most research on the work conditions and family responsibilities associated with work-family conflict and other measures of mental health uses the individual employee as the unit of analysis. We argue that work conditions are both individual psychosocial assessments and objective characteristics of the proximal work environment, necessitating multilevel analyses of both individual- and team-level work conditions on mental health. Methodology/approach This study uses multilevel data on 748 high-tech professionals in 120 teams to investigate relationships between team- and individual-level job conditions, work-family conflict, and four mental health outcomes (job satisfaction, emotional exhaustion, perceived stress, and psychological distress). Findings We find that work-to-family conflict is socially patterned across teams, as are job satisfaction and emotional exhaustion. Team-level job conditions predict team-level outcomes, while individuals’ perceptions of their job conditions are better predictors of individuals’ work-to-family conflict and mental health. Work-to-family conflict operates as a partial mediator between job demands and mental health outcomes. Practical implications Our findings suggest that organizational leaders concerned about presenteeism, sickness absences, and productivity would do well to focus on changing job conditions in ways that reduce job demands and work-to-family conflict in order to promote employees’ mental health. Originality/value of the chapter We show that both work-to-family conflict and job conditions can be fruitfully framed as team characteristics, shared appraisals held in common by team members. This challenges the framing of work-to-family conflict as a “private trouble” and provides support for work-to-family conflict as a structural mismatch grounded in the social and temporal organization of work. PMID:25866431

  7. Single-collision studies of hot atom energy transfer and chemical reaction

    International Nuclear Information System (INIS)

    Valentini, J.J.

    1991-01-01

    This report discusses research in the collision dynamics of translationally hot atoms, with funding with DOE for the project ''Single-Collision Studies of Hot Atom Energy Transfer and Chemical Reaction,'' Grant Number DE-FG03-85ER13453. The work reported here was done during the period September 9, 1988 through October 31, 1991. During this period this DOE-funded work has been focused on several different efforts: (1) experimental studies of the state-to-state dynamics of the H + RH → H 2 R reactions where RH is CH 4 , C 2 H 6 , or C 3 H 8 , (2) theoretical (quasiclassical trajectory) studies of hot hydrogen atom collision dynamics, (3) the development of photochemical sources of translationally hot molecular free radicals and characterization of the high resolution CARS spectroscopy of molecular free radicals, (4) the implementation of stimulated Raman excitation (SRE) techniques for the preparation of vibrationally state-selected molecular reactants

  8. Association of Maternal Working Condition with Low Birth Weight ...

    African Journals Online (AJOL)

    Background: The socioeconomic conditions have made more job opportunities available to women. This has created interest to conduct studies on the effect of working lifestyle on pregnancy outcomes. Aim: This study was conducted with the aim to assess the relationship between mothers' working status as a social ...

  9. Multicriteria ranking of workplaces regarding working conditions in a mining company.

    Science.gov (United States)

    Bogdanović, Dejan; Stanković, Vladimir; Urošević, Snežana; Stojanović, Miloš

    2016-12-01

    Ranking of workplaces with respect to working conditions is very significant for each company. It indicates the positions where employees are most exposed to adverse effects resulting from the working environment, which endangers their health. This article presents the results obtained for 12 different production workplaces in the copper mining and smelting complex RTB Bor - 'Veliki Krivelj' open pit, based on six parameters measured regularly which defined the following working environment conditions: air temperature, light, noise, dustiness, chemical hazards and vibrations. The ranking of workplaces has been performed by PROMETHEE/GAIA. Additional optimization of workplaces is done by PROMETHEE V with the given limits related to maximum permitted values for working environment parameters. The obtained results indicate that the most difficult workplace is on the excavation location (excavator operator). This method can be successfully used for solving similar kinds of problems, in order to improve working conditions.

  10. Getting into hot water Problematizing hot water service demand: The case of Old Cairo

    Science.gov (United States)

    Culhane, Thomas Henry

    proxies for assets in the built environment, are significant in model 2. With this information about how infrastructure affects consumer choice, and predictors from our models of the average family's willingness to spend discretional income on a new heater, we might suggest that policy aiming at improving the water delivery infrastructure might make a difference. With the right policies enforced, what are now "cold-water flats" could safely, inexpensively and reliably accommodate technologies that provide differentiated water temperatures in separate pipelines. This analysis of consumer choice regarding hot water as a combined water and energy and technological utility contributes to our understanding of redevelopment policy in three ways. First, it provides insights into what is really being valued in terms of amenities at the household level and the self-help strategies people employ to achieve desired end utility. Second, it identifies non-traditional issues, often overlooked in neighborhood improvement scenarios that may help make slum renovation programs more successful. Third, the study reveals the complexities involved in obtaining standard amenities, such as hot water, for low-income groups. Paradoxically, government subsidies for water and energy intended to help the poor may have hurt them by locking them into patterns of behavior which, coupled with architectural decisions sanctioned by the government, severely limit the ability of the poor to take advantage of new opportunities or avoid being constrained by changing conditions at a time of rising energy and resource costs. The findings from this dissertation show that we can not make the assumption that consumers in these areas will move increasingly toward conventional water heating appliances under current conditions; in fact many families have had such units and abandoned them for economic, utility and safety reasons. A rethink is necessary of how government, the private sector, NGOs and individual

  11. Modeling Hot-Spot Contributions in Shocked High Explosives at the Mesoscale

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-12

    When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with modeling, but now scientists are realizing their importance and new modeling systems that can accurately model hot spots are underway.

  12. Microbial ecology of hot desert edaphic systems.

    Science.gov (United States)

    Makhalanyane, Thulani P; Valverde, Angel; Gunnigle, Eoin; Frossard, Aline; Ramond, Jean-Baptiste; Cowan, Don A

    2015-03-01

    A significant proportion of the Earth's surface is desert or in the process of desertification. The extreme environmental conditions that characterize these areas result in a surface that is essentially barren, with a limited range of higher plants and animals. Microbial communities are probably the dominant drivers of these systems, mediating key ecosystem processes. In this review, we examine the microbial communities of hot desert terrestrial biotopes (including soils, cryptic and refuge niches and plant-root-associated microbes) and the processes that govern their assembly. We also assess the possible effects of global climate change on hot desert microbial communities and the resulting feedback mechanisms. We conclude by discussing current gaps in our understanding of the microbiology of hot deserts and suggest fruitful avenues for future research. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. HOT 2010

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010....

  14. HOT 2013

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010.......En undersøgelse af, hvad der er hot - og burde være hot på læseområdet. I undersøgelsen deltager en række læsekyndige fra praksisfeltet, professionshøjskolerne og forskningsområdet. Undersøgelsen er gentaget hvert år siden 2010....

  15. Surveillance and radiological protection in the Hot Cell laboratory

    International Nuclear Information System (INIS)

    Ramirez, J.M.; Torre, J. De la; Garcia C, M.A.

    2004-01-01

    The Hot Cells Laboratory (LCC) located in the National Institute of Nuclear Research are an installation that was designed for the management at distance of 10,000 Curies of Co-60 or other radioactive materials with different values in activity. The management of such materials in the installation, implies to analyze and to determine the doses that the POE will receive as well as the implementation of protection measures and appropriate radiological safety so that is completed the specified by the ALARA concept. In this work it is carried out an evaluation of the doses to receive for the POE when managing radionuclides with maximum activities that can be allowed in function of the current conditions of the cells and an evaluation of results is made with the program of surveillance and radiological protection implemented for the development of the works that carried out in the installation. (Author)

  16. Suppression of sawtooth oscillations due to hot electrons and hot ions

    International Nuclear Information System (INIS)

    Zhang, Y.Z.; Berk, H.L.

    1989-01-01

    The theory of m = 1 kink mode stabilization is discussed in the presence of either magnetically trapped hot electrons or hot ions. For instability hot ion requires particles peaked inside the q = 1 surface, while hot electrons require that its pressure profile be increasing at the q = 1 surface. Experimentally observed sawtooth stabilization usually occurs with off-axis heating with ECRH and near axis heating with ICRH. Such heating may produce the magnetically trapped hot particle pressure profiles that are consistent with theory. 17 refs., 2 figs

  17. Nuclear track radiography of 'hot' aerosol particles

    International Nuclear Information System (INIS)

    Boulyga, S.F.; Kievitskaja, A.I.; Kievets, M.K.; Lomonosova, E.M.; Zhuk, I.V.; Yaroshevich, O.I.; Perelygin, V.P.; Petrova, R.; Brandt, R.; Vater, P.

    1999-01-01

    Nuclear track radiography was applied to identify aerosol 'hot' particles which contain elements of nuclear fuel and fallout after Chernobyl NPP accident. For the determination of the content of transuranium elements in radioactive aerosols the measurement of the α-activity of 'hot' particles by SSNTD was used in this work, as well as radiography of fission fragments formed as a result of the reactions (n,f) and (γ,f) in the irradiation of aerosol filters by thermal neutrons and high energy gamma quanta. The technique allowed the sizes and alpha-activity of 'hot' particles to be determined without extracting them from the filter, as well as the determination of the uranium content and its enrichment by 235 U, 239 Pu and 241 Pu isotopes. Sensitivity of determination of alpha activity by fission method is 5x10 -6 Bq per particle. The software for the system of image analysis was created. It ensured the identification of track clusters on an optical image of the SSNTD surface obtained through a video camera and the determination of size and activity of 'hot' particles

  18. Performance analysis of organic Rankine cycles using different working fluids

    Directory of Open Access Journals (Sweden)

    Zhu Qidi

    2015-01-01

    Full Text Available Low-grade heat from renewable or waste energy sources can be effectively recovered to generate power by an organic Rankine cycle (ORC in which the working fluid has an important impact on its performance. The thermodynamic processes of ORCs using different types of organic fluids were analyzed in this paper. The relationships between the ORC’s performance parameters (including evaporation pressure, condensing pressure, outlet temperature of hot fluid, net power, thermal efficiency, exergy efficiency, total cycle irreversible loss, and total heat-recovery efficiency and the critical temperatures of organic fluids were established based on the property of the hot fluid through the evaporator in a specific working condition, and then were verified at varied evaporation temperatures and inlet temperatures of the hot fluid. Here we find that the performance parameters vary monotonically with the critical temperatures of organic fluids. The values of the performance parameters of the ORC using wet fluids are distributed more dispersedly with the critical temperatures, compared with those of using dry/isentropic fluids. The inlet temperature of the hot fluid affects the relative distribution of the exergy efficiency, whereas the evaporation temperature only has an impact on the performance parameters using wet fluid.

  19. Effect of external hot EGR dilution on combustion, performance and particulate emissions of a GDI engine

    International Nuclear Information System (INIS)

    Xie, Fangxi; Hong, Wei; Su, Yan; Zhang, Miaomiao; Jiang, Beiping

    2017-01-01

    Highlights: • Effect of hot EGR on combustion and PN emission is investigated on a GDI engine. • Appropriate addition of hot EGR can reduce fuel consumption, NO_x and PN emission. • Relationship between BSFC and emissions of hot EGR is better than cooled EGR. • Condition with low-medium speeds and medium loads are more suitable for hot EGR. - Abstract: In this paper, an experimental investigation about the influence of hot EGR addition on the engine combustion, performance and particulate number emission was conducted at a spark-ignition gasoline direct injection (GDI) engine. Meanwhile, the different effects between cooled and hot EGR addition methods were compared and the variations of fuel consumption and particle number emissions under six engine operating conditions with different speeds and loads were analyzed. The research result indicated that increasing hot EGR ratio properly with adjustment of ignition timing could effectively improve the relationship among brake-specific fuel consumption (BSFC), NO_x and particle number emissions. When hot EGR ratio increased to 20%, not only BSFC but also the NO_x and particle number emissions were reduced, which were about 7%, 87% and 36% respectively. Compared with cooled EGR, the flame development and propagation speeds were accelerated, and cycle-by-cycle combustion variation decreased with hot EGR. Meanwhile, using hot EGR made the engine realize a better relationship among fuel consumption, NO_x and particle number emissions. The biggest improvements of BSFC, NO_x and particle number emissions were obtained at low-medium speed and medium load engine conditions by hot EGR addition method. While engine speed increased and load decreased, the improvement of engine fuel consumption and emission reduced with hot EGR method.

  20. Hot laboratory in Saclay. Equipment and radio-metallurgy technique of the hot lab in Saclay. Description of hot cell for handling of plutonium salts. Installation of an hot cell

    International Nuclear Information System (INIS)

    Bazire, R.; Blin, J.; Cherel, G.; Duvaux, Y.; Cherel, G.; Mustelier, J.P.; Bussy, P.; Gondal, G.; Bloch, J.; Faugeras, P.; Raggenbass, A.; Raggenbass, P.; Fufresne, J.

    1959-01-01

    Describes the conception and installation of the hot laboratory in Saclay (CEA, France). The construction ended in 1958. The main aim of this laboratory is to examine fuel rods of EL2 and EL3 as well as nuclear fuel studies. It is placed in between both reactors. In a first part, the functioning and specifications of the hot lab are given. The different hot cells are described with details of the ventilation and filtration system as well as the waste material and effluents disposal. The different safety measures are explained: description of the radiation protection, decontamination room and personnel monitoring. The remote handling equipment is composed of cutting and welding machine controlled with manipulators. Periscopes are used for sight control of the operation. In a second part, it describes the equipment of the hot lab. The unit for an accurate measurement of the density of irradiated uranium is equipped with an high precision balance and a thermostat. The equipment used for the working of irradiated uranium is described and the time length of each operation is given. There is also an installation for metallographic studies which is equipped with a manipulation bench for polishing and cleaning surfaces and a metallographic microscope. X-ray examination of uranium pellets will also be made and results will be compared with those of metallography. The last part describes the hot cells used for the manipulation of plutonium salts. The plutonium comes from the reprocessing plant and arrived as a nitric solution. Thus these cells are used to study the preparation of plutonium fluorides from nitric solution. The successive operations needed are explained: filtration, decontamination and extraction with TBP, purification on ion exchangers and finally formation of the plutonium fluorides. Particular attention has been given to the description of the specifications of the different gloveboxes and remote handling equipment used in the different reaction steps and

  1. Psychosocial working conditions and depressive symptoms among Swedish employees

    DEFF Research Database (Denmark)

    Magnusson Hanson, Linda L; Theorell, Töres; Bech, Per

    2009-01-01

    Survey 2003. Work demands, decision authority, support and conflicts at work were measured in 2003. Depressive symptoms were recorded in 2006 by a short version of the depression subscale of the Symptom Checklist 90 (SCL-90). Linear regression analyses were performed. RESULTS: After adjusting......PURPOSE: To investigate prospective associations between working conditions and depressive symptoms in Swedish men and women. METHODS: The study was based on SLOSH (N = 5,985), a follow-up of a representative sample of gainfully employed Swedes 16-64 years of age from the Swedish Work Environment...... authority, support and conflicts at work are predictive of depressive symptoms in the general Swedish working population....

  2. Changes in working conditions for home healthcare workers and impacts on their work activity and on their emotions

    Directory of Open Access Journals (Sweden)

    Corinne Van De Weerdt

    2015-06-01

    Full Text Available Home healthcare is steadily growing in many countries. Nevertheless, it is known that home healthcare workers are frequently exposed to a variety of potentially serious occupational hazards. Working conditions have changed to become more emotionally and physically demanding on workers. Emotional labor is increasingly high in this profession. Time pressure is increasingly common. This paper describes an ergonomic study analyzing the working conditions of nursing assistants and nurses, as well as the impacts of their work in terms of job satisfaction, emotions at work, relationships with the others, and occupational stress. The study shows that changing working conditions are making it increasingly difficult for home healthcare workers to do their work properly. We can confirm that such workers use strategies to try to cope. They use individual strategies to preserve the relational dimension of their work activity. These strategies are specifically centered around preserving the relationships with patients, and coping with the demands of the job. The study also shows that workers use strategies to express emotions and to conceal them from others. Finally, the paper presents the recommendations that were discussed with the manager and workers for improving working conditions and that led to practical proposals: e.g. implementing certain items of equipment better suited to difficult care, encouraging assistance between workers when operations so require through appropriate organizational measures, extending emotion-focused work discussion groups with management involvement.

  3. Hot interstellar matter in elliptical galaxies

    CERN Document Server

    Kim, Dong-Woo

    2012-01-01

    Based on a number of new discoveries resulting from 10 years of Chandra and XMM-Newton observations and corresponding theoretical works, this is the first book to address significant progress in the research of the Hot Interstellar Matter in Elliptical Galaxies. A fundamental understanding of the physical properties of the hot ISM in elliptical galaxies is critical, because they are directly related to the formation and evolution of elliptical galaxies via star formation episodes, environmental effects such as stripping, infall, and mergers, and the growth of super-massive black holes. Thanks to the outstanding spatial resolution of Chandra and the large collecting area of XMM-Newton, various fine structures of the hot gas have been imaged in detail and key physical quantities have been accurately measured, allowing theoretical interpretations/predictions to be compared and tested against observational results. This book will bring all readers up-to-date on this essential field of research.

  4. Technology Change And Working Conditions – A Cultural Perspective

    DEFF Research Database (Denmark)

    Sørensen, Ole Henning

    2004-01-01

    When technology change improves working conditions, the success is often attributed to skilful change agents. When it is not, the blame is on “resistance to change” and “resilient cultures”. How can these failures be understood differently? A cultural perspective on technology change might be a way...... to facilitate technology change processes that lead to improved working conditions. The research based project described here has developed a special homepage that explains how this might be achieved. The homepage is targeted at working life professionals. The homepage presents theoretical explanations...... of the concept of organizational culture, a model for analysis and several practical case stories. This paper explains how the project tries to reach a broad spectrum of professionals in order to facilitate their use of a cultural perspective. It also discusses the ethical consequences of the cultural...

  5. Long-lived hot-carrier light emission and large blue shift in formamidinium tin triiodide perovskites

    NARCIS (Netherlands)

    Fang, Hong-Hua; Adjokatse, Sampson; Shao, Shuyan; Even, Jacky; Loi, Maria Antonietta

    2018-01-01

    A long-lived hot carrier population is critical in order to develop working hot carrier photovoltaic devices with efficiencies exceeding the Shockley-Queisser limit. Here, we report photoluminescence from hot-carriers with unexpectedly long lifetime (a few ns) in formamidinium tin triiodide. An

  6. The optimization of production and control of hot-electron plasmas

    International Nuclear Information System (INIS)

    1989-01-01

    The present project was initially undertaken to develop a number of innovative concepts for using electron cyclotron heating (ECH) to enhance tokamak performance. A common feature of the various applications under consideration is efficient, spatially-localized generation of hot-electron plasmas; and the first phase of the work addressed the basic aspects of an approach to achieving this Upper Off-Resonant Heating (UORH) and open-resonator couplers to confine the weakly damped microwave power to the particular region where the hot electrons are to be generated. The results of the first year's work provided strong evidence that hot-electron plasmas with electron energies of hundreds of keV could be generated using multiple-frequency ECH and fully-toroidal open-resonator couplers. The evidence was sufficiently compelling to suggest that the project be focused on a suitable near-term application to the TEXT device

  7. Jumping-droplet electronics hot-spot cooling

    Science.gov (United States)

    Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; Yin, Sabrina L.; Rentauskas, Michelle; Neely, Jason; Pilawa-Podgurski, Robert C. N.; Miljkovic, Nenad

    2017-03-01

    Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm × 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobic surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25 °C air temperature, 20%-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm) and applied heat flux (demonstrated to 13 W/cm2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm2. This work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.

  8. Jumping-droplet electronics hot-spot cooling

    International Nuclear Information System (INIS)

    Oh, Junho; Birbarah, Patrick; Foulkes, Thomas; Yin, Sabrina L.; Rentauskas, Michelle

    2017-01-01

    Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method to achieve active hot spot cooling in electronic devices. To test the viability of EFE condensation, we developed an experimental setup to remove heat via droplet evaporation from single and multiple high power gallium nitride (GaN) transistors acting as local hot spots (4.6 mm x 2.6 mm). An externally powered circuit was developed to direct jumping droplets from a copper oxide (CuO) nanostructured superhydrophobic surface to the transistor hot spots by applying electric fields between the condensing surface and the transistor. Heat transfer measurements were performed in ambient air (22-25°C air temperature, 20-45% relative humidity) to determine the effect of gap spacing (2-4 mm), electric field (50-250 V/cm), and heat flux (demonstrated to 13 W/cm"2). EFE condensation was shown to enhance the heat transfer from the local hot spot by ≈ 200% compared to cooling without jumping and by 20% compared to non-EFE jumping. Dynamic switching of the electric field for a two-GaN system reveals the potential for active cooling of mobile hot spots. The opportunity for further cooling enhancement by the removal of non-condensable gases promises hot spot heat dissipation rates approaching 120 W/cm"2. Finally, this work provides a framework for the development of active jumping droplet based vapor chambers and heat pipes capable of spatial and temporal thermal dissipation control.

  9. Hot corrosion testing of Ni-based alloys and coatings in a modified Dean rig

    Science.gov (United States)

    Steward, Jason Reid

    Gas turbine blades are designed to withstand a variety of harsh operating conditions. Although material and coating improvements are constantly administered to increase the mean time before turbine refurbishment or replacement, hot corrosion is still considered as the major life-limiting factor in many industrial and marine gas turbines. A modified Dean rig was designed and manufactured at Tennessee Technological University to simulate the accelerated hot corrosion conditions and to conduct screening tests on the new coatings on Ni-based superalloys. Uncoated Ni-based superalloys, Rene 142 and Rene 80, were tested in the modified Dean rig to establish a testing procedure for Type I hot corrosion. The influence of surface treatments on the hot corrosion resistance was then investigated. It was found that grit-blasted specimens showed inferior hot corrosion resistance than that of the polished counterpart. The Dean rig was also used to test model MCrAlY alloys, pack cementation NiAl coatings, and electro-codeposited MCrAlY coatings. Furthermore, the hot corrosion attack on the coated-specimens were also assessed using a statistical analysis approach.

  10. Experimental evidence of hot carriers solar cell operation in multi-quantum wells heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Rodière, Jean; Lombez, Laurent, E-mail: laurent.lombez@chimie-paristech.fr [IRDEP, Institute of R and D on Photovoltaic Energy, UMR 7174, CNRS-EDF-Chimie ParisTech, 6 Quai Watier-BP 49, 78401 Chatou Cedex (France); Le Corre, Alain; Durand, Olivier [INSA, FOTON-OHM, UMR 6082, F-35708 Rennes (France); Guillemoles, Jean-François [IRDEP, Institute of R and D on Photovoltaic Energy, UMR 7174, CNRS-EDF-Chimie ParisTech, 6 Quai Watier-BP 49, 78401 Chatou Cedex (France); NextPV, LIA CNRS-RCAST/U. Tokyo-U. Bordeaux, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

    2015-05-04

    We investigated a semiconductor heterostructure based on InGaAsP multi quantum wells (QWs) using optical characterizations and demonstrate its potential to work as a hot carrier cell absorber. By analyzing photoluminescence spectra, the quasi Fermi level splitting Δμ and the carrier temperature are quantitatively measured as a function of the excitation power. Moreover, both thermodynamics values are measured at the QWs and the barrier emission energy. High values of Δμ are found for both transition, and high carrier temperature values in the QWs. Remarkably, the quasi Fermi level splitting measured at the barrier energy exceeds the absorption threshold of the QWs. This indicates a working condition beyond the classical Shockley-Queisser limit.

  11. Low cycle fatigue behavior of hot-bent 347 stainless steel in a simulated PWR water environment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Ho; Seo, Myung Gyu; Jang, Chang Heui [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Hong, Jong Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Tae Soon [Central Research InstituteKorea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of)

    2016-11-15

    The effect of hot bending on the Low cycle fatigue (LCF) behavior of 347 SS was evaluated in Room temperature (RT) air and simulated Pressurized water reactor (PWR) water environments. The LCF life of 347 SS in PWR water was shorter than that in RT air for the as-received and hot-bent conditions. The LCF life of hot-bent 347 SS was relatively longer than that of the as-received condition in both RT air and PWR water. Microstructure analysis indicated development of dislocation structure near niobium carbide particles and increase in dislocation density for the hot-bent 347 SS. Such microstructure acted as barriers to dislocation movement during the LCF test, resulting in minimal hardening for the hot-bent 347 SS in RT air.

  12. HOT DUST OBSCURED GALAXIES WITH EXCESS BLUE LIGHT: DUAL AGN OR SINGLE AGN UNDER EXTREME CONDITIONS?

    Energy Technology Data Exchange (ETDEWEB)

    Assef, R. J.; Diaz-Santos, T. [Núcleo de Astronomía de la Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército Libertador 441, Santiago (Chile); Walton, D. J.; Brightman, M. [Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, D.; Eisenhardt, P. R. M.; Tsai, C.-W. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-236, Pasadena, CA 91109 (United States); Alexander, D. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Bauer, F. [Departamento de Astronomía y Astrofísica, Pontificia Universidad Católica de Chile, Casilla 306, Santiago 22 (Chile); Blain, A. W. [Physics and Astronomy, University of Leicester, 1 University Road, Leicester LE1 7RH (United Kingdom); Finkelstein, S. L. [The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712 (United States); Hickox, R. C. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, NH 03755 (United States); Wu, J. W., E-mail: roberto.assef@mail.udp.cl [UCLA Astronomy, P.O. Box 951547, Los Angeles, CA 90095-1547 (United States)

    2016-03-10

    Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (AGN) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high AGN obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the AGN by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured AGN in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13–050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed AGN, and is strongly inconsistent with the presence of a secondary unobscured AGN. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M{sub ⊙} yr{sup −1}. Deep polarimetry observations could confirm the reflection hypothesis.

  13. HOT DUST OBSCURED GALAXIES WITH EXCESS BLUE LIGHT: DUAL AGN OR SINGLE AGN UNDER EXTREME CONDITIONS?

    International Nuclear Information System (INIS)

    Assef, R. J.; Diaz-Santos, T.; Walton, D. J.; Brightman, M.; Stern, D.; Eisenhardt, P. R. M.; Tsai, C.-W.; Alexander, D.; Bauer, F.; Blain, A. W.; Finkelstein, S. L.; Hickox, R. C.; Wu, J. W.

    2016-01-01

    Hot dust-obscured galaxies (Hot DOGs) are a population of hyper-luminous infrared galaxies identified by the Wide-field Infrared Survey Explorer (WISE) mission from their very red mid-IR colors, and characterized by hot dust temperatures (T > 60 K). Several studies have shown clear evidence that the IR emission in these objects is powered by a highly dust-obscured active galactic nucleus (AGN) that shows close to Compton-thick absorption at X-ray wavelengths. Thanks to the high AGN obscuration, the host galaxy is easily observable, and has UV/optical colors usually consistent with those of a normal galaxy. Here we discuss a sub-population of eight Hot DOGs that show enhanced rest-frame UV/optical emission. We discuss three scenarios that might explain the excess UV emission: (i) unobscured light leaked from the AGN by reflection over the dust or by partial coverage of the accretion disk; (ii) a second unobscured AGN in the system; or (iii) a luminous young starburst. X-ray observations can help discriminate between these scenarios. We study in detail the blue excess Hot DOG WISE J020446.13–050640.8, which was serendipitously observed by Chandra/ACIS-I for 174.5 ks. The X-ray spectrum is consistent with a single, hyper-luminous, highly absorbed AGN, and is strongly inconsistent with the presence of a secondary unobscured AGN. Based on this, we argue that the excess blue emission in this object is most likely either due to reflection or a co-eval starburst. We favor the reflection scenario as the unobscured star formation rate needed to power the UV/optical emission would be ≳1000 M ⊙ yr −1 . Deep polarimetry observations could confirm the reflection hypothesis

  14. Workplace Rehabilitation and Supportive Conditions at Work: A Prospective Study

    OpenAIRE

    Ahlstrom, Linda; Hagberg, Mats; Dellve, Lotta

    2012-01-01

    Purpose To investigate the impact of rehabilitation measures on work ability and return to work (RTW), specifically the association between workplace rehabilitation/supportive conditions at work and work ability and RTW over time, among women on long-term sick leave. Methods Questionnaire data were collected (baseline, 6 and 12?months) from a cohort of women (n?=?324). Linear mixed models were used for longitudinal analysis of the repeated measurements of work ability index (WAI), work abilit...

  15. Performance investigation of low – Concentration photovoltaic systems under hot and arid conditions: Experimental and numerical results

    International Nuclear Information System (INIS)

    Yousef, Mohamed S.; Abdel Rahman, Ali K.; Ookawara, S.

    2016-01-01

    Highlights: • Influence of cooling on the performance of photovoltaic systems. • A comprehensive model (optical, thermal, and electrical) was developed. • Experimental measurements were conducted under hot climate conditions. • For conventional photovoltaic with cooling, about 11% more power was obtained. • For concentrated photovoltaic with cooling, about 15% more power was obtained. - Abstract: In this study, a comparative performance analysis was performed between a conventional photovoltaic system and a low-concentration photovoltaic system. Two typical photovoltaic modules and two compound parabolic concentrating photovoltaic systems were examined. A Cooling system was employed to lower the temperature of the solar cells in each of the two configurations. Experimental and numerical investigations of the performance of the two arrangements with and without cooling were presented. Experiments were conducted outdoors at the Egypt-Japan University of Science and Technology, subjected to the hot climate conditions of New Borg El-Arab City, Alexandria, Egypt (Longitude/Latitude: E 029°42′/N 30°55′). A comprehensive system model was established, which comprises an optical model, coupled with thermal and electrical models. The coupled model was developed analytically and solved numerically, using MATLAB software, to assess the overall performance of the two configurations, considering the concentration ratio of the concentrated photovoltaic system to be 2.4X. The results indicated that cooling the solar panels considerably improved the electrical power yield of the photovoltaic systems. By employing cooling, the temperatures of the conventional photovoltaic system and the concentrated photovoltaic system were effectively lowered by approximately 25% and 30%, respectively, resulting in a significant enhancement in the electrical power output of the photovoltaic system by 11% and that of the concentrated photovoltaic system by 15%. Furthermore, the

  16. Psychosocial working conditions and cognitive complaints among Swedish employees.

    Directory of Open Access Journals (Sweden)

    Cecilia U D Stenfors

    Full Text Available BACKGROUND: Cognitive complaints involving problems with concentration, memory, decision-making and thinking are relatively common in the work force. The sensitivity of both subjective and objective cognitive functioning to common psychiatric conditions, stress levels and to cognitive load makes it plausible that psychosocial working conditions play a role in cognitive complaints. Thus, this study aimed to test the associations between psychosocial work factors and cognitive complaints in nationally representative samples of the Swedish work force. Cross-sectional (n = 9751 and prospective (n = 3644; two time points two years apart sequential multiple regression analyses were run, adjusting for general confounders, depressive- and sleeping problems. Additional prospective analyses were run adjusting for baseline cognitive complaints. CROSS/SECTIONAL RESULTS: High quantitative demands, information and communication technology (ICT demands, under qualification and conflicts were positively associated with cognitive complaints, while social support, good resources at work and over qualification were negatively associated with cognitive complaints in all models. Skill discretion and decision authority were weakly associated with cognitive complaints. Conflicts were more strongly associated with cognitive complaints in women than in men, after adjustment for general confounders. PROSPECTIVE RESULTS: Quantitative job demands, ICT demands and under qualification were positively associated with future cognitive complaints in all models, including when adjusted for baseline cognitive complaints. Decision authority was weakly positively associated with future cognitive complaints, only after adjustment for depressive- and sleeping problems respectively. Social support was negatively associated with future cognitive complaints after adjustment for general confounders and baseline cognitive complaints. Skill discretion and resources were negatively

  17. Labour market specific institutions and the working conditions of labour migrants:

    DEFF Research Database (Denmark)

    Arnholtz, Jens; Hansen, Nana Wesley

    2013-01-01

    Based on a respondent driven sampling survey with 500 Polish migrant workers in Denmark, this article argues that specific labour market institutions and sector differences need to be taken into account when explaining the working conditions of migrant workers. Comparing the working conditions...... of Polish and Danish workers, it is shown that labour market institutional arrangements provide a better explanation for the differences found between the two groups than differences in individual characteristics of the migrants and the Danish workforce. In addition, the article argues that factors...... such as institutionalized wage variability within sectors and the decentralized regulation of working conditions are important when assessing the potential implication of migrant workers in the labour market....

  18. Parametric analysis of a combined dew point evaporative-vapour compression based air conditioning system

    Directory of Open Access Journals (Sweden)

    Shailendra Singh Chauhan

    2016-09-01

    Full Text Available A dew point evaporative-vapour compression based combined air conditioning system for providing good human comfort conditions at a low cost has been proposed in this paper. The proposed system has been parametrically analysed for a wide range of ambient temperatures and specific humidity under some reasonable assumptions. The proposed system has also been compared from the conventional vapour compression air conditioner on the basis of cooling load on the cooling coil working on 100% fresh air assumption. The saving of cooling load on the coil was found to be maximum with a value of 60.93% at 46 °C and 6 g/kg specific humidity, while it was negative for very high humidity of ambient air, which indicates that proposed system is applicable for dry and moderate humid conditions but not for very humid conditions. The system is working well with an average net monthly power saving of 192.31 kW h for hot and dry conditions and 124.38 kW h for hot and moderate humid conditions. Therefore it could be a better alternative for dry and moderate humid climate with a payback period of 7.2 years.

  19. Microstructures and recrystallization behavior of severely hot-deformed tungsten

    International Nuclear Information System (INIS)

    Mathaudhu, S.N.; De Rosset, A.J.; Hartwig, K.T.; Kecskes, L.J.

    2009-01-01

    When coarse-grained (CG) tungsten (W) is heavily worked by equal-channel angular extrusion (ECAE), the grain size is reduced to the ultrafine-grained/nanocrystalline regimes (UFG/NC) and the strength and ductility increase. Because of the brittle nature of CG W, the material must be hot-extruded, and, if the temperatures are near the recrystallization temperature (T rc ), gains in properties may not be maximized. In this study, the recrystallization behavior of ECAE-processed CG W is examined as a function of the imparted strain (i.e., number of extrusions) and the hot-working extrusion temperature. Up to four ECAE passes were performed in tooling with a 90 deg. channel intersection, and at temperatures of 1000 deg. C or 1200 deg. C. Subsequent 60 min annealing of the worked material to 1600 deg. C allowed for the determination of T rc . Vickers microhardness measurements and scanning electron microscopy, were used to characterize the microstructures in the as-worked and recrystallized states. The ECAE-processed W shows increased microstructural break-up and refinement with increasing strain and decreasing hot-working temperature in the fully worked state. T rc was determined to be ∼1400 deg. C, which is nearly independent of the number of extrusions and the working temperature. These results show that if ECAE is accomplished below 1400 deg. C (i.e., at 1000 deg. C or lower) the attractive properties of the UFG/NC-worked W may be retained. Specifically, below 1000 deg. C, with increasing strain imparted to the material, high hardness values with a concomitant grain size refinement (∼350 nm) could be expected

  20. Measurements of hot spots and electron beams in Z-pinch devices

    International Nuclear Information System (INIS)

    Deeney, C.

    1988-04-01

    Hot spots and Electron Beams have been observed in different types of Z-pinches. There is, however, no conclusive evidence on how either are formed although there has been much theoretical interest in both these phenomena. In this thesis, nanosecond time resolved and time correlated, X-ray and optical diagnostics, are performed on two different types of Z-pinch: a 4 kJ, 30 kV Gas Puff Z-pinch and a 28 kJ, 60 kV Plasma Focus. The aim being to study hot spots and electron beams, as well as characterise the plasma, two different Z-pinch devices. Computer codes are developed to analyse the energy and time resolved data obtained in this work. These codes model both, X-ray emission from a plasma and X-ray emission due to electron beam bombardment of a metal surface. The hot spot and electron beam parameters are measured, from the time correlated X-ray data using these computer codes. The electron beams and the hot spots are also correlated to the plasma behaviour and to each other. The results from both devices are compared with each other and with the theoretical work on hot spot and electron beam formation. A previously unreported 3-5 keV electron temperature plasma is identified, in the gas puff Z-pinch plasma, prior to the formation of the hot spots. it is shown, therefore, that the hot spots are more dense but not hotter than the surrounding plasma. Two distinct periods of electron beam generation are identified in both devices. (author)

  1. [Occupational differences in exposure to hazardous work conditions].

    Science.gov (United States)

    Marinacci, Chiara; d'Errico, A; Cardano, M; Perini, F; Costa, G

    2005-01-01

    Few studies have been aimed at describing organizational and psychosocial conditions of the Italian workforce by occupational group, and they have been mainly conducted within specific occupations. The present study aimed at identifying specific groups of occupations which have unfavourable profiles from the point of view of exposure to specific organizational factors and psychosocial risks, and to physical, chemical and ergonomic risks, and analyzing their distribution by worker age. The analysis was conducted on a sample of 4,195 workers in the Piedmont Region who were members of the CGIL Trade Union (Italian General Confederation of Labour), who answered a self-administered questionnaire in 2000, aimed at assessing chemical, physical, and ergonomic risks, accidents, and psychosocial factors connected with work organization and work tasks. Psychosocial risks were assessed via three scales aimed at measuring the degree of control, psychophysical demands, and worker satisfaction. The proportion of workers exposed to the above mentioned risks was analysed according to occupational group. This group was then compared with all other groups taken together, according to prevalence of high strain condition (combination of high demand and low control) and HSUR condition (High Strain Unfairly Rewarded; combination of high strain and low satisfaction). Among males aged 25-44 years, restricted to the occupation groups with more than ten workers in high strain condition, significantly higher proportions of stress were observed in leather workers and shoemakers, paper factory workers, rubber workers, crane and bridge crane operators, plastic workers, painters, transport drivers and carpenters. For many of these groups, excesses were confirmed for the HSUR condition. Among subjects aged over 44 years, a higher risk for high strain was confirmed in rubber workers, transport drivers and carpenters. In addition, machine tool operators, assembly line and mechanical workers in this

  2. HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES

    International Nuclear Information System (INIS)

    Winn, Joshua N.; Albrecht, Simon; Fabrycky, Daniel; Johnson, John Asher

    2010-01-01

    We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T eff > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.

  3. Do psychosocial working conditions modify the effect of depressive symptoms on long-term sickness absence?

    DEFF Research Database (Denmark)

    Hjarsbech, Pernille U.; Christensen, Karl Bang; Andersen, Rikke Voss

    2013-01-01

    , but not psychosocial working conditions, predicted LTSA. Psychosocial working conditions did not statistically significantly modify the effect of depressive symptoms on LTSA. Conclusions: Psychosocial working conditions did not modify the effect of depressive symptoms on LTSA. The results, however, need......Background: The objective of this study was to investigate whether work unit-levels of psychosocial working conditions modify the effect of depressive symptoms on risk of long-term sickness absence (LTSA). Methods: A total of 5,416 Danish female eldercare workers from 309 work units were surveyed...... using questionnaires assessing depressive symptoms and psychosocial working conditions. LTSA was derived from a national register. We aggregated scores of psychosocial working conditions to the work unit-level and conducted multi-level Poisson regression analyses. Results: Depressive symptoms...

  4. Hospital nurses' working conditions in relation to motivation and patient safety.

    Science.gov (United States)

    Toode, Kristi; Routasalo, Pirkko; Helminen, Mika; Suominen, Tarja

    2015-03-01

    There is a lack of empirical knowledge about nurses' perceptions of their workplace characteristics and conditions, such as level of autonomy and decision authority, work climate, teamwork, skill exploitation and learning opportunities, and their work motivation in relation to practice outputs such as patient safety. Such knowledge is needed particularly in countries, such as Estonia, where hospital systems for preventing errors and improving patient safety are in the early stages of development. This article reports the findings from a cross-sectional survey of hospital nurses in Estonia that was aimed at determining their perceptions of workplace characteristics, working conditions, work motivation and patient safety, and at exploring the relationship between these. Results suggest that perceptions of personal control over their work can affect nurses' motivation, and that perceptions of work satisfaction might be relevant to patient safety improvement work.

  5. Netherlands EWCO CAR on Working conditions in the retail sector – National contribution

    NARCIS (Netherlands)

    Hooftman, W.; Houtman, I.; Kwantes, J.H.

    2012-01-01

    Based on the Netherlands Working Condition Survey (NWCS), this report exaines working conditions in the retail sector in the Netherlands. It concludes that the retail sector is a sector in which many young employees work. These employees often work part-time and have a temporary contract. The retail

  6. Forgeability test of extruded Mg–Sn–Al–Zn alloys under warm forming conditions

    International Nuclear Information System (INIS)

    Yoon, Jonghun; Park, Sunghyuk

    2014-01-01

    Highlights: • We compared forgeability of new developed TAZ alloys with conventional AZ alloys. • Forgeability was evaluated with a T-shape forging under hot forming condition. • TAZ alloys show the best performance in forgeability under hot forging condition. • Microstructures of the forged part were investigated with EBSD experiments. • YS and UTS of forged part with TAZ alloy are enhanced compared with AZ alloy. - Abstract: Magnesium (Mg) alloys have been thoroughly researched to replace steel or aluminum parts in automotives for reducing weight without sacrificing their strength. The widespread use of Mg alloys has been limited by its insufficient formability, which results from a lack of active slip systems at room temperature. It leads to a hot forming process for Mg alloys to enhance the formability and plastic workability. In addition, forged or formed parts of Mg alloys should have the reliable initial yield and ultimate tensile strength after hot working processes since its material properties should be compatible with other parts thereby guaranteeing structural safety against external load and crash. In this research, an optimal warm forming condition for applying extruded Mg–Sn–Al–Zn (TAZ) Mg alloys into automotive parts is proposed based on T-shape forging tests and the feasibility of forged parts is evaluated by measuring the initial yield strength and investigating the grain size in orientation imaging microscopy (OIM) maps

  7. A low temperature aluminizing treatment of hot work tool steel

    Energy Technology Data Exchange (ETDEWEB)

    Matijevic, B., E-mail: bozidar.matijevic@fsb.hr [University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Zagreb (Croatia)

    2010-07-01

    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to hot tool steel H13. The aluminizing treating temperature was from 550 to 620°C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the aluminized layer thickness and the oxide layer were studied. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), glow discharge optical spectroscopy (GDOS) were applied to observe the cross-sections and the distribution of elements. (author)

  8. A low temperature aluminizing treatment of hot work tool steel

    International Nuclear Information System (INIS)

    Matijevic, B.

    2010-01-01

    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to hot tool steel H13. The aluminizing treating temperature was from 550 to 620°C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the aluminized layer thickness and the oxide layer were studied. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), glow discharge optical spectroscopy (GDOS) were applied to observe the cross-sections and the distribution of elements. (author)

  9. First-Trimester Working Conditions and Birthweight: A Prospective Cohort Study

    NARCIS (Netherlands)

    Vrijkotte, Tanja G. M.; van der Wal, Marcel F.; van Eijsden, Manon; Bonsel, Gouke J.

    2009-01-01

    Objectives. We investigated the relationship between women's first-trimester working conditions and infant birthweight. Methods. Pregnant women (N=8266) participating in the Amsterdam Born Children and Their Development study completed a questionnaire gathering information on employment and working

  10. Hot cell renovation in the spent fuel conditioning process facility at the Korea Atomic Energy Research Institute

    Directory of Open Access Journals (Sweden)

    Seung Nam Yu

    2015-10-01

    Results and conclusion: Based on the considered refurbishment workflow, previous equipment in the M8 cell, including vessels and pipes, were removed and disposed of successfully after a zoning smear survey and decontamination, and new equipment with advanced functions and specifications were installed in the hot cell. Finally, the operating area and isolation room were also refurbished to meet the requirements of the improved hot cell facility.

  11. Small Is Not Always Beautiful – A Comparative Study Of Working Conditions

    DEFF Research Database (Denmark)

    Sørensen, Ole Henning; Hasle, Peter; Bach, Elsa

    2004-01-01

    When considering working conditions, the myth sometimes holds that small is beautiful. Some studies of occupational accidents show that small companies have fever accidents than large. This indicates that small companies have better working conditions than large. A Danish study based on a random...... sample of employees in the general industry rejects this myth. The figures show that physical working conditions become systematically worse the smaller the size of privately owned companies. The study also supports international data that small companies underreport accidents, and that this might...... be the reason why small seems beautiful....

  12. Time to B. cereus about hot chocolate.

    Science.gov (United States)

    Nelms, P K; Larson, O; Barnes-Josiah, D

    1997-01-01

    To determine the cause of illnesses experienced by employees of a Minneapolis manufacturing plant after drinking hot chocolate bought from a vending machine and to explore the prevalence of similar vending machine-related illnesses. The authors inspected the vending machines at the manufacturing plant where employees reported illnesses and at other locations in the city where hot chocolate beverages were sold in machines. Tests were performed on dry mix, water, and beverage samples and on machine parts. Laboratory analyses confirmed the presence of B. cereus in dispensed beverages at a concentration capable of causing illness (170,000 count/gm). In citywide testing of vending machines dispensing hot chocolate, 7 of the 39 licensed machines were found to be contaminated, with two contaminated machines having B. cereus levels capable of causing illness. Hot chocolate sold in vending machines may contain organisms capable of producing toxins that under favorable conditions, can induce illness. Such illnesses are likely to be underreported. Even low concentrations of B. cereus may be dangerous for vulnerable populations such as the aged or immunosuppressed. Periodic testing of vending machines is thus warranted. The relationship between cleaning practices and B. cereus contamination is an issue for further study.

  13. Effects of hot water pre-extraction on surface properties of bagasse soda pulp.

    Science.gov (United States)

    Cordeiro, Nereida; Ashori, Alireza; Hamzeh, Yahya; Faria, Marisa

    2013-03-01

    In this work, the effects of hot water pre-extraction of depithed bagasse on the soda pulping and surface properties were studied. The conditions of hot water pre-extraction were: maximum temperature 170 °C, heat-up time 90 min, time at maximum temperature 10 min, and solid to liquor ratio (S:L) 1:8. Consequently, the pre-extracted and un-extracted bagasse chips were subjected to soda pulping at 160 °C for 1h with 11, 14 and 17% active alkali charge and an S:L of 1:5. The results showed that the hot water pre-extraction increased bagasse surface texture porosity by hemicellulose degradation. Therefore, the delignification was faster for pulping of pre-extracted samples. At a certain charge of alkali, pre-extracted samples showed higher screened yield and lower Kappa number. For instance, at 17% alkali charge, pre-extracted bagasse gave 11.3% higher pulp yield compared with the un-extracted ones. Inverse gas chromatography (IGC) results showed that the hot water pre-extraction changed the active sites on the bagasse surface, decreasing the dispersive energy and the basicity character, and affected the particle morphology. The pulping process decreased the hydrophobicity and the basicity of the bagasse surface. The surfaces of un-extracted and pre-extracted bagasse pulps had similar properties but different morphology. The pulps present higher surface area and permeability with more reactive capacity. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. ESTIMATION OF THE IMPORTANCE OF BIOLOGICAL VALUE OF NUTRITION ALLOWANCES OF SPORTSMEN OF WEIGHTLIFTING IN THE CONDITIONS OF THE HOT CLIMATE

    OpenAIRE

    BAXROM TUHTAROV

    2011-01-01

    The work observes options of optimal average daily food diets for weightlifting athletes in a hot climate through measuring the biological value of diets. It is established, that balance of nutrientsin the changed nutrition background reached an optimum level and made 1:1.1:4.1, against 1:1.2:4.9 on actual food intake. The optimum ratio of nutrients in the average daily food rations of sportsmen on the changed nutrition background is reached byincreasing norms of proteins of animal origin, v...

  15. Psychosocial work conditions, social capital, and daily smoking: a population based study.

    Science.gov (United States)

    Lindström, M

    2004-09-01

    To investigate the associations between psychosocial conditions at work, social capital/social participation, and daily smoking. The 2000 public health survey in Scania is a cross sectional postal questionnaire study with a 59% participation rate. A total of 5180 persons aged 18-64 years that belonged to the work force and the unemployed were included in this study. Logistic regression models were used to investigate the associations between psychosocial factors at work/unemployment, social participation, and daily smoking. Psychosocial conditions at work were defined according to the Karasek-Theorell demand-control/decision latitudes into relaxed, active, passive, and jobstrain categories. The multivariate analyses included age, country of origin, education and economic stress. 17.2% proportion of all men and 21.9% of all women were daily smokers. The jobstrain (high demands/low control) and unemployed categories had significantly higher odds ratios of daily smoking among both men and women compared to the relaxed (low demands/high control) reference category. The passive (low demands/low control), jobstrain, and unemployed categories were also significantly associated with low social participation. Low social participation was significantly and positively associated with daily smoking within each of the psychosocial work conditions and unemployed categories. The positive association between low social capital/low social participation and daily smoking is well known. However, both social participation and daily smoking are associated with psychosocial work conditions and unemployment. Psychosocial work conditions and unemployment may affect daily smoking both directly and through a pathway including social participation.

  16. Analysis of working conditions and comportment of prevention in radiation protection

    International Nuclear Information System (INIS)

    Bouhnik, C.

    1992-01-01

    In this article, the author presents analysis methods of working conditions( environment of working stations, working stress, socio-technical environment, ability and, emotion and relation phenomena) that permit to understand how the prevention comportment is regulated

  17. Hot Carrier Generation and Extraction of Plasmonic Alloy Nanoparticles.

    Science.gov (United States)

    Valenti, Marco; Venugopal, Anirudh; Tordera, Daniel; Jonsson, Magnus P; Biskos, George; Schmidt-Ott, Andreas; Smith, Wilson A

    2017-05-17

    The conversion of light to electrical and chemical energy has the potential to provide meaningful advances to many aspects of daily life, including the production of energy, water purification, and optical sensing. Recently, plasmonic nanoparticles (PNPs) have been increasingly used in artificial photosynthesis (e.g., water splitting) devices in order to extend the visible light utilization of semiconductors to light energies below their band gap. These nanoparticles absorb light and produce hot electrons and holes that can drive artificial photosynthesis reactions. For n-type semiconductor photoanodes decorated with PNPs, hot charge carriers are separated by a process called hot electron injection (HEI), where hot electrons with sufficient energy are transferred to the conduction band of the semiconductor. An important parameter that affects the HEI efficiency is the nanoparticle composition, since the hot electron energy is sensitive to the electronic band structure of the metal. Alloy PNPs are of particular importance for semiconductor/PNPs composites, because by changing the alloy composition their absorption spectra can be tuned to accurately extend the light absorption of the semiconductor. This work experimentally compares the HEI efficiency from Ag, Au, and Ag/Au alloy nanoparticles to TiO 2 photoanodes for the photoproduction of hydrogen. Alloy PNPs not only exhibit tunable absorption but can also improve the stability and electronic and catalytic properties of the pure metal PNPs. In this work, we find that the Ag/Au alloy PNPs extend the stability of Ag in water to larger applied potentials while, at the same time, increasing the interband threshold energy of Au. This increasing of the interband energy of Au suppresses the visible-light-induced interband excitations, favoring intraband excitations that result in higher hot electron energies and HEI efficiencies.

  18. The Relation Between Alloy Chemistry and Hot-Cracking

    Science.gov (United States)

    Nunes, A. C., Jr.; Talia, J. E.

    2000-01-01

    Hot cracking is a problem in welding 2195 aluminum-lithium alloy. Weld wire additives seem to reduce the problem. This study proposes a model intended to clarify the way alloying elements affect hot-cracking. The brittle temperature range of an alloy extends wherever the tensile stress required to move the meniscus of the liquid film at the grain/dendrite boundaries is less than the bulks flow stress Sigma(sub B) of the grains: 2gamma/delta alloys outgas.) If the above condition is not met, the grains deform under stress and the liquid film remains in place. Curves of 2gamma/delta and sigma(sub B) vs. temperature in the range just below the melting temperature determine the hot cracking susceptibility of an alloy. Both are zero at onset of solidification. sigma(sub B) rises as the thermal activation of the slip mechanism is reduced. 2gamma/delta rises as the film thickness delta which can be estimated from the Scheil equation, drops. But, given an embrittled alloy, whether the alloy actually cracks is determined by the strain imposed upon it in the embrittled condition. A critical strain is estimated, Epsilon(sub C) on the order of Epsilon(sub C) is approximately delta/l where L = grain size and where the the volume increment due to the strain, concentrated at the liquid film, is on the order of the liquid film volume. In the early 80's an empirical critical strain cracking envelope Epsilon(sub C)(T) was incorporated into a damage criterion to estimate the effect of welding parameters on the formation of microfissures in a superalloy with good results. These concepts, liquid film decoherence vs. grain bulk deformation and critical strain, form the key elements of a quantitative theory of hot-cracking applicable for assessing the effect of alloying elements on hot-cracking during welding.

  19. Freezing Range, Melt Quality, and Hot Tearing in Al-Si Alloys

    Science.gov (United States)

    Uludağ, Muhammet; Çetin, Remzi; Dispinar, Derya

    2018-02-01

    In this study, three different aluminum-silicon alloys (A356, A413, and A380) that have different solidification morphology and solidification ranges were examined with an aim to evaluate the hot tearing susceptibility. T-shape mold and Constrained Rod Casting (CRC) mold were used for the characterization. Reduced Pressure Test (RPT) was used to quantify the casting quality by measuring bifilm index. It was found that bifilm index and solidification range have an important role on the hot tearing formation. As it is known, bifilms can cause porosity and in this case, it was shown that porosity formed by bifilms decreased hot tearing tendency. As the freezing range of alloy increases, bifilms find the time to unravel that reduces hot tearing. However, for eutectic alloy (A413), due to zero freezing range, regardless of bifilm content, hot tearing was never observed. A380.1 alloy had the highest tendency for hot tearing due to having the highest freezing range among the alloys investigated in this work.

  20. Presenteeism among self-employed workers: Korean working conditions survey.

    Science.gov (United States)

    Kim, Min-Su; Park, Jae Bum; Min, Kyoung-Bok; Lee, Kyung-Jong; Kwon, Kimin

    2014-01-01

    Presenteeism has become a public concern recently. Thus, we aimed to understand the relationship between self-employed workers and presenteeism using a nationally representative sample of Korean workers. Using data from the Korean Working Conditions Survey conducted in 2011, a total of 43,392 workers including paid employees and self-employed workers were analyzed. The effect of employment status on presenteeism was analyzed using logistic regression analysis. The independent variables were socioeconomic characteristics, working conditions, and working environments. Among the 43,392 workers, 34,783 were paid and 8,609 were self-employed. Self-employed workers were more likely to exhibit presenteeism than were paid workers. An elevated odds ratio of 1.27 (95% CI 1.19-1.36) was found for presenteeism among self-employed workers. Being self-employed was significantly related with exhibiting presenteeism. Additional research should investigate whether other factors mediate the relationship between employment status and presenteeism as well as ways to reduce presenteeism among self-employed workers.

  1. Working conditions as risk factors for disability retirement: a longitudinal register linkage study

    Science.gov (United States)

    2012-01-01

    Background Early retirement due to disability is a public health and work environment problem that shortens working careers. Transition to disability retirement is based on ill-health, but working conditions are also of relevance. We examined the contributions of work arrangements, physical working conditions and psychosocial working conditions to subsequent disability retirement. Methods The data were derived from the Helsinki Health Study cohort on employees of the City of Helsinki, Finland. Information on working conditions was obtained from the baseline surveys conducted in 2000, 2001 and 2002. These data were linked with register data on disability retirement and their main diagnoses obtained from the Finnish Centre for Pensions. Follow up by the end of 2008 yielded 525 disability retirement events. The analysed data included 6525 participants and 525 disability retirement events. Hazard ratios (HR) and 95% confidence intervals (95% CI) were calculated from Cox regression analysis. Results Several working conditions showed own associations with disability retirement before adjustment. After adjustment for all working conditions, the primary risk factors for all-cause disability retirement were physical workload among women (HR 2.02, 95% CI 1.57-2.59) and men (HR 2.00, 95% CI 1.18-3.38), and low job control among women (HR 1.60, 95% CI 1.29-1.99). In addition, for disability retirement due to musculoskeletal causes, the risk factors were physical workload and low job control. For disability retirement due to mental causes the risk factors were computer work and low job control. Furthermore, occupational class was a risk factor for disability retirement due to all causes and musculoskeletal diseases. Conclusions Among various working conditions, those that are physically demanding and those that imply low job control are potential risk factors for disability retirement. Improving the physical working environment and enhancing control over one’s job is likely

  2. Perceived unfairness in working conditions: The case of public health services in Tanzania

    Directory of Open Access Journals (Sweden)

    Massay Deodatus

    2011-02-01

    Full Text Available Abstract Background The focus on the determinants of the quality of health services in low-income countries is increasing. Health workers' motivation has emerged as a topic of substantial interest in this context. The main objective of this article is to explore health workers' experience of working conditions, linked to motivation to work. Working conditions have been pointed out as a key factor in ensuring a motivated and well performing staff. The empirical focus is on rural public health services in Tanzania. The study aims to situate the results in a broader historical context in order to enhance our understanding of the health worker discourse on working conditions. Methods The study has a qualitative study design to elicit detailed information on health workers' experience of their working conditions. The data comprise focus group discussions (FGDs and in-depth interviews (IDIs with administrators, clinicians and nursing staff in the public health services in a rural district in Tanzania. The study has an ethnographic backdrop based on earlier long-term fieldwork in the same part of Tanzania. Results The article provides insights into health workers' understanding and assessment of their working conditions. An experience of unsatisfactory working conditions as well as a perceived lack of fundamental fairness dominated the FGDs and IDIs. Informants reported unfairness with reference to factors such as salary, promotion, recognition of work experience, allocation of allowances and access to training as well as to human resource management. The study also revealed that many health workers lack information or knowledge about factors that influence their working conditions. Conclusions The article calls for attention to the importance of locating the discourse of unfairness related to working conditions in a broader historical/political context. Tanzanian history has been characterised by an ambiguous and shifting landscape of state regulation

  3. The Impact of Ceramic Shell Strength on Hot Tearing during Investment Casting

    International Nuclear Information System (INIS)

    Norouzi, Saeid; Farhangi, Hassan

    2011-01-01

    The effect of ceramic shell strength on hot tearing susceptibility during solidification was inspected practicing investment casting of the cobalt-base superalloy samples with the same casting conditions, but different ceramic shell systems. Results showed that the lower the ceramic shell strength upon using polymer additives, the lower the hindered contraction rate, and the lower the hindered contraction rate, the smaller the hot tearing tendency. Optical microscopy and electron microscopy scanning revealed that the hot tear propagated along the last solidified interdendritic phase, and that the hot tear surface had two major modes: 1) the ductile region in the outer layer; and 2) the inner region of liquid embrittlement.

  4. Effect of cryogenic treatment on microstructure, mechanical and wear behaviors of AISI H13 hot work tool steel

    Science.gov (United States)

    Koneshlou, Mahdi; Meshinchi Asl, Kaveh; Khomamizadeh, Farzad

    2011-01-01

    This paper focuses on the effects of low temperature (subzero) treatments on microstructure and mechanical properties of H13 hot work tool steel. Cryogenic treatment at -72 °C and deep cryogenic treatment at -196 °C were applied and it was found that by applying the subzero treatments, the retained austenite was transformed to martensite. As the temperature was decreased more retained austenite was transformed to martensite and it also led to smaller and more uniform martensite laths distributed in the microstructure. The deep cryogenic treatment also resulted in precipitation of more uniform and very fine carbide particles. The microstructural modification resulted in a significant improvement on the mechanical properties of the H13 tool steel.

  5. Work conditions and the food choice coping strategies of employed parents.

    Science.gov (United States)

    Devine, Carol M; Farrell, Tracy J; Blake, Christine E; Jastran, Margaret; Wethington, Elaine; Bisogni, Carole A

    2009-01-01

    How work conditions relate to parents' food choice coping strategies. Pilot telephone survey. City in the northeastern United States (US). Black, white, and Hispanic employed mothers (25) and fathers (25) randomly recruited from low-/moderate-income zip codes; 78% of those reached and eligible participated. Sociodemographic characteristics; work conditions (hours, shift, job schedule, security, satisfaction, food access); food choice coping strategies (22 behavioral items for managing food in response to work and family demands (ie, food prepared at/away from home, missing meals, individualizing meals, speeding up, planning). Two-tailed chi-square and Fisher exact tests (P restaurant meals, missed breakfast, and prepared entrees. Job security, satisfaction, and food access were also associated with gender-specific strategies. Structural work conditions among parents such as job hours, schedule, satisfaction, and food access are associated with food choice coping strategies with importance for dietary quality. Findings have implications for worksite interventions but need examination in a larger sample.

  6. LSTM-Based Temperature Prediction for Hot-Axles of Locomotives

    Directory of Open Access Journals (Sweden)

    Luo Can

    2017-01-01

    Full Text Available The reliability of locomotives plays a central role for the smooth operation of railway systems. Hot-axle failures are one of the most commonly found problems leading to locomotive accidents. Since the operating status of the locomotive axle bearings can be distinctly reflected by the axle temperatures, online temperature monitoring has become an essential way to detect hot-axle failures. In this work, we explore the feasibility of predict the hot-axle failures by identifying the temperature from predicted nominal values. We propose a data-driven approach based on the Long Short-Term Memory (LSTM network to predict the sensor temperature for axle bearings. The effectiveness of the prediction model was validated with operation data collected from commercial locomotives. With a prediction accuracy is within a few percent, the proposed techniques can be used as a dynamic reference for hot-axle monitoring.

  7. Hot-crack test for aluminium alloys welds using TIG process

    Science.gov (United States)

    Niel, A.; Deschaux-Beaume, F.; Bordreuil, C.; Fras, G.

    2010-06-01

    Hot cracking is a critical defect frequently observed during welding of aluminium alloys. In order to better understand the interaction between cracking phenomenon, process parameters, mechanical factors and microstructures resulting from solidification after welding, an original hot-cracking test during welding is developed. According to in-situ observations and post mortem analyses, hot cracking mechanisms are investigated, taking into account the interaction between microstructural parameters, depending on the thermal cycles, and mechanical parameters, depending on geometry and clamping conditions of the samples and on the thermal field on the sample. Finally, a process map indicating the limit between cracking and non-cracking zones according to welding parameters is presented.

  8. The Cabin Crew Blues. Middle-aged Cabin Attendants and Their Working Conditions

    Directory of Open Access Journals (Sweden)

    Ann Bergman

    2015-12-01

    Full Text Available This article examines how an airline company uses the labor of a group of middle-aged cabin attendants in an industry increasingly characterized by deregulation and competiveness. The study was based on in-depth interviews with seven women, all with between 24 and 30 years of work experience as cabin attendants. The article focuses on the women’s working conditions and well-being and the analysis reveals three key aspects—intensification of work, vulnerability, and aging—that affect the cabin attendants’ experiences and emotions in relation to the work. It is at the intersection of these three aspects that the cabin attendants’ concerns must be understood. The study’s findings indicated that positive emotions such as job satisfaction and commitment have diminished because of exploitative and otherwise poor working conditions. Taking the cabin attendants’ concerns as its point of departure, the article shows that there is a need to move away from a discussion about emotional labor toward a discussion of working conditions.

  9. DBAC: A simple prediction method for protein binding hot spots based on burial levels and deeply buried atomic contacts

    Science.gov (United States)

    2011-01-01

    Background A protein binding hot spot is a cluster of residues in the interface that are energetically important for the binding of the protein with its interaction partner. Identifying protein binding hot spots can give useful information to protein engineering and drug design, and can also deepen our understanding of protein-protein interaction. These residues are usually buried inside the interface with very low solvent accessible surface area (SASA). Thus SASA is widely used as an outstanding feature in hot spot prediction by many computational methods. However, SASA is not capable of distinguishing slightly buried residues, of which most are non hot spots, and deeply buried ones that are usually inside a hot spot. Results We propose a new descriptor called “burial level” for characterizing residues, atoms and atomic contacts. Specifically, burial level captures the depth the residues are buried. We identify different kinds of deeply buried atomic contacts (DBAC) at different burial levels that are directly broken in alanine substitution. We use their numbers as input for SVM to classify between hot spot or non hot spot residues. We achieve F measure of 0.6237 under the leave-one-out cross-validation on a data set containing 258 mutations. This performance is better than other computational methods. Conclusions Our results show that hot spot residues tend to be deeply buried in the interface, not just having a low SASA value. This indicates that a high burial level is not only a necessary but also a more sufficient condition than a low SASA for a residue to be a hot spot residue. We find that those deeply buried atoms become increasingly more important when their burial levels rise up. This work also confirms the contribution of deeply buried interfacial atomic contacts to the energy of protein binding hot spot. PMID:21689480

  10. Biomass gasification hot gas cleanup for power generation

    Energy Technology Data Exchange (ETDEWEB)

    Wiant, B.C.; Bachovchin, D.M. [Westinghouse Electric Corp., Orlando, FL (United States); Carty, R.H.; Onischak, M. [Institute of Gas Technology, Chicago, IL (United States); Horazak, D.A. [Gilbert/Commonwealth, Reading, PA (United States); Ruel, R.H. [The Pacific International Center for High Technology Research, Honolulu, HI (United States)

    1993-12-31

    In support of the US Department of Energy`s Biomass Power Program, a Westinghouse Electric led team consisting of the Institute of Gas Technology (IGT), Gilbert/Commonwealth (G/C), and the Pacific International Center for High Technology Research (PICHTR), is conducting a 30 month research and development program. The program will provide validation of hot gas cleanup technology with a pressurized fluidized bed, air-blown, biomass gasifier for operation of a gas turbine. This paper discusses the gasification and hot gas cleanup processes, scope of work and approach, and the program`s status.

  11. Tribological properties of anti-wear PVD coatings for elevated temperatures application deposited onto X37CrMoV5-1 type hot work steel

    International Nuclear Information System (INIS)

    Dobrzanski, L.A.; Polok, M.; Adamiak, M.

    2003-01-01

    The paper presents results of tribological and adhesion investigations of anti-wear PVD coatings TiN, TiN/(Ti,Al)N and CrN types deposited in ion plating PVD process onto X37CrMoV5-1 type hot work tool steel. It was found that damage mechanism during scratch test in all investigated coatings begins with multiple spallings located on the scratch edges followed by cracking and tool coatings delamination. Regarding to the coating types it can be seen different location of such damages and loads typical for them. According to this observations it can be stated that highest adhesion among investigated coating present, CrN monolayer coating and the lowest one multilayers Ti/(Ti,Al)N coating. The wear resistance was investigated by pin-on-disc method performed in room and elevated to 500 o C temperatures. It was found that the lowest wear in to fixed investigation conditions in both room and elevated temperatures shows TiN monolayer coating. Additionally one can see that TiN coatings application improve wear resistance some five times. (author)

  12. Results of work in the hot cells of Laboratory Testing Materials Irradiated Areva of Carina project for the expansion of the database of mechanical characteristics of fractures in materials of RPV German irradiated

    International Nuclear Information System (INIS)

    Barthelmes, J.; Schabel, H.; Hein, H.; Kein, E.; Eiselt, C.

    2013-01-01

    In the frame of the already completed research projects CARINA and its predecessor CARISMA a data base was created for pre-irradiated original RPV steels of German PWRs which allowed to examine the consequences if the Master Curve (T 0 ) approach instead of the RT N OT concept is applied to the RPV safety assessment. Furthermore in CARINA different irradiation conditions with respect to the accumulated neutron fluences and specific impact parameters were investigated. Besides a brief introduction of the CARINA project and an overview of the main results an overview on the requirements of the hot laboratory work in terms of specimen manufacturing and material testing is given and examples for realization are shown. (Author)

  13. Hot-electron nanoscopy using adiabatic compression of surface plasmons

    KAUST Repository

    Giugni, Andrea; Torre, Bruno; Toma, Andrea; Francardi, Marco; Malerba, Mario; Alabastri, Alessandro; Proietti Zaccaria, Remo; Stockman, Mark Mark; Di Fabrizio, Enzo M.

    2013-01-01

    Surface plasmon polaritons are a central concept in nanoplasmonics and have been exploited to develop ultrasensitive chemical detection platforms, as well as imaging and spectroscopic techniques at the nanoscale. Surface plasmons can decay to form highly energetic (or hot) electrons in a process that is usually thought to be parasitic for applications, because it limits the lifetime and propagation length of surface plasmons and therefore has an adverse influence on the functionality of nanoplasmonic devices. Recently, however, it has been shown that hot electrons produced by surface plasmon decay can be harnessed to produce useful work in photodetection, catalysis and solar energy conversion. Nevertheless, the surface-plasmon-to-hot-electron conversion efficiency has been below 1% in all cases. Here we show that adiabatic focusing of surface plasmons on a Schottky diode-terminated tapered tip of nanoscale dimensions allows for a plasmon-to-hot-electron conversion efficiency of ∼30%. We further demonstrate that, with such high efficiency, hot electrons can be used for a new nanoscopy technique based on an atomic force microscopy set-up. We show that this hot-electron nanoscopy preserves the chemical sensitivity of the scanned surface and has a spatial resolution below 50 nm, with margins for improvement.

  14. Hot-electron nanoscopy using adiabatic compression of surface plasmons

    KAUST Repository

    Giugni, Andrea

    2013-10-20

    Surface plasmon polaritons are a central concept in nanoplasmonics and have been exploited to develop ultrasensitive chemical detection platforms, as well as imaging and spectroscopic techniques at the nanoscale. Surface plasmons can decay to form highly energetic (or hot) electrons in a process that is usually thought to be parasitic for applications, because it limits the lifetime and propagation length of surface plasmons and therefore has an adverse influence on the functionality of nanoplasmonic devices. Recently, however, it has been shown that hot electrons produced by surface plasmon decay can be harnessed to produce useful work in photodetection, catalysis and solar energy conversion. Nevertheless, the surface-plasmon-to-hot-electron conversion efficiency has been below 1% in all cases. Here we show that adiabatic focusing of surface plasmons on a Schottky diode-terminated tapered tip of nanoscale dimensions allows for a plasmon-to-hot-electron conversion efficiency of ∼30%. We further demonstrate that, with such high efficiency, hot electrons can be used for a new nanoscopy technique based on an atomic force microscopy set-up. We show that this hot-electron nanoscopy preserves the chemical sensitivity of the scanned surface and has a spatial resolution below 50 nm, with margins for improvement.

  15. Compact Buried Ducts in a Hot-Humid Climate House

    Energy Technology Data Exchange (ETDEWEB)

    Mallay, Dave [Home Innovation Research Labs, Upper Marlboro, MD (United States)

    2016-01-07

    "9A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences; 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs; 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

  16. Sol Duc Hot Springs feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    1981-12-01

    Sol Duc Springs is located in the Olympic National Park in western Washington state. Since the turn of the century, the area has served as a resort, offering hot mineral baths, lodge and overnight cabin accommodations. The Park Service, in conjunction with the concessionaire, is in the process of renovating the existing facilities, most of which are approximately 50 years old. The present renovation work consists of removing all of the existing cabins and replacing them with 36 new units. In addition, a new hot pool is planned to replace the existing one. This report explores the possibility of a more efficient use of the geothermal resource to accompany other planned improvements. It is important to note that the system outlined is based upon the resource development as it exists currently. That is, the geothermal source is considered to be: the two existing wells and the hot springs currently in use. In addition, every effort has been made to accommodate the priorities for utilization as set forth by the Park Service.

  17. Part of the job: the role of physical work conditions in the nurse turnover process.

    Science.gov (United States)

    Vardaman, James M; Cornell, Paul T; Allen, David G; Gondo, Maria B; Muslin, Ivan S; Mobley, Robin N; Brock, Meagan E; Sigmon, Tracy L

    2014-01-01

    Retention of nursing staff remains an important issue for health care managers. Turnover research has focused primarily on motivational and social factors as keys to retention, whereas the role of the physical work conditions has received considerably less attention. However, work design theory suggests that physical work conditions may be an important factor in fostering retention among nursing staff. The aim of this study was to integrate work design theory with turnover process models to explore the influence of perceptions of physical work conditions on the development of turnover intentions among nursing staff. Drawing on two samples of registered nurses working in cancer units in metropolitan hospitals in the southeastern United States, this study explores the impact of perceptions of physical work conditions on turnover intentions using ordinary least squares regression. Hypotheses are tested in Study 1 and replicated in Study 2. A measure of perceptions of physical work conditions is also developed and validated using exploratory (Study 1) and confirmatory (Study 2) factor analyses. Perceptions of physical work conditions explain variance in turnover intentions above than that explained by motivational and social factors. Specifically, employee perceptions of noisy work conditions are found to significantly increase turnover intentions, whereas perceptions that work conditions facilitate tasks were found to significantly reduce turnover intentions. Perceptions of temperature and health hazard did not show significant effects. Results suggest that health care managers and scholars should re-examine the role of physical work conditions in the turnover process. Investments in upgrades that facilitate tasks may foster retention better than investments that simply improve employee comfort. Negative perceptions of work conditions may have no impact if they are considered a normal "part of the job," although negative perceptions of conditions that are viewed as

  18. Properties of Galvanized and Galvannealed Advanced High Strength Hot Rolled Steels

    Energy Technology Data Exchange (ETDEWEB)

    V.Y. Guertsman; E. Essadiqi; S. Dionne; O. Dremmailova; R. Bouchard; B. Voyzelle; J. McDermid; R. Fourmentin

    2008-04-01

    The objectives of the project were (i) to develop the coating process information to achieve good quality coatings on 3 advanced high strength hot rolled steels while retaining target mechanical properties, (ii) to obtain precise knowledge of the behavior of these steels in the various forming operations and (iii) to establish accurate user property data in the coated conditions. Three steel substrates (HSLA, DP, TRIP) with compositions providing yield strengths in the range of 400-620 MPa were selected. Only HSLA steel was found to be suitable for galnaizing and galvannealing in the hot rolled condition.

  19. Analysis on energy-saving path of rural buildings in hot summer and cold winter zone

    Science.gov (United States)

    Huang, Mingqiang; Li, Jinheng

    2018-02-01

    Since the reform and opening policy, the construction of rural area in China has become more and more important. The idea of establishing green villages needs to be accepted and recognized by the public. The hot summer and cold winter zone combines two contradictory weather conditions that is cold winter and hot summer. So the living conditions are limited. In response to this climate, residents extensively use electric heaters or air conditioning to adjust the indoor temperature, resulting in energy waste and environmental pollution. In order to improve the living conditions of residents, rural area energy conservation has been put on the agenda. Based on the present situation and energy consumption analysis of the rural buildings in the hot summer and cold winter zone, this article puts forward several energy saving paths from government, construction technology and so on

  20. Mechanical design and testing of a hot-gas turbine on a test facility

    International Nuclear Information System (INIS)

    Staude, R.

    1981-01-01

    Advanced calculation methods and specific solutions for any particular problem are basic requirements for the mechanical design of hot-gas components for gas turbines. The mechanical design contributes a great deal to the smooth running and operational reliability and thus to the quality of the machine. By reference to an expander, the present paper discusses the strength of hot components, such as the casing and the rotor, for both stationary and transient temperature distribution. Mechanical testing under hot-gas conditions fully confirmed the reliability of the rating and design of the hot-gas turbines supplied by M:A.N.-GHH STERKRADE. (orig.) [de

  1. Hot spot formation on different tokamak wall materials

    International Nuclear Information System (INIS)

    Nedospasov, A.V.; Bezlyudny, I.V.

    1998-01-01

    The thermal contraction phenomenon and generation of 'hot spots' due to thermoemission were described. The paper consider non-linear stages of heat contraction on the graphite, beryllium, tungsten and vanadium wall. It is shown that on the beryllium surface hot spot can't appear due to strong cooling by sublimation. For other materials the conditions of hot spot appearance due to local superheating of the wall have been calculated and their parameters were found: critical surface temperature, size of spots and their temperature profiles, heat fluxes from plasma to the spots. It have been calculated fluxes of sublimating materials from spots to the plasma. It is noticed that nominal temperature of the grafite divertor plate, accepted in ITER's project to being equal 1500 C, is lower then critical temperature of the development heat contraction due to thermoemission. (orig.)

  2. Construction of an external electrode for determination of electrochemical corrosion potential in normal operational conditions of an BWR type reactor for hot cells

    International Nuclear Information System (INIS)

    Aguilar T, J.A.; Rivera M, H.; Hernandez C, R.

    2001-01-01

    The behavior of the corrosion processes at high temperature requires of external devices that being capable to resist a temperature of 288 Centigrade and a pressure of 80 Kg/cm 2 , to give stable and reproducible results of some variable and resisting physically and chemically the radiation. The external electrode of Ag/AgCl fulfils all the requirements in the determination of the electrochemical corrosion potential under normal operational conditions of a BWR type reactor in hot cells. (Author)

  3. Work on the hot atom chemistry at the Institute of Nuclear Sciences Boris Kidric, Vinca, Yugoslavia; Hemija vruceg atoma

    Energy Technology Data Exchange (ETDEWEB)

    Veljkovic, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1969-07-01

    A survey of work on hot atom chemistry from the establishment of the Institute up to now, where the role of Prof. P. Savic, should be specially emphasized, is given. The investigations in this domain during the first period, were directed to solve various problems in production of radioactive isotopes. Today these investigations are closely associated with the work in radiochemistry, physical chemistry of liquid and solid systems and fast reaction kinetics improving the development of these branches (author) [Serbo-Croat] Daje se pregled rada na hemiji vruceg atoma od osnivanja Instituta do danas, pri cemu se narocito istice uloga koju je u tome imao prof. P. Savic. Dok su u prvom periodu istrazivanja u ovoj oblasti doprinosila resavanju raznih problema proizvodnje radioaktivnih izotopa, ona su danas tesno povezana sa radom u radiohemiji, fizickoj hemiji tecnih i cvrstih sistema, kinetici brzih reakcija, doprinoseci sa svoje strane razvoju tih oblasti (author)

  4. Hot electron plasma equilibrium and stability in the Constance B mirror experiment

    International Nuclear Information System (INIS)

    Chen, Xing.

    1988-04-01

    An experimental study of the equilibrium and macroscopic stability property of an electron cyclotron resonance heating (ECRH) generated plasma in a minimum-B mirror is presented. The Constance B mirror is a single cell quadrupole magnetic mirror in which high beta (β ≤ 0.3) hot electron plasmas (T/sub e/≅400 keV) are created with up to 4 kW of ECRH power. The plasma equilibrium profile is hollow and resembles the baseball seam geometry of the magnet which provides the confining magnetic field. This configuration coincides with the drift orbit of deeply trapped particles. The on-axis hollowness of the hot electron density profile is 50 /+-/ 10%, and the pressure profile is at least as hollow as, if not more than, the hot electron density profile. The hollow plasma equilibrium is macroscopically stable and generated in all the experimental conditions in which the machine has been operated. Small macroscopic plasma fluctuations in the range of the hot electron curvature drift frequency sometimes occur but their growth rate is small (ω/sub i//ω/sub r/ ≤ 10 -2 ) and saturate at very low level (δB//bar B/ ≤ 10 -3 ). Particle drift reversal is predicted to occur for the model pressure profile which best fits the experimental data under the typical operating conditions. No strong instability is observed when the plasma is near the drift reversal parameter regime, despite a theoretical prediction of instability under such conditions. The experiment shows that the cold electron population has no stabilizing effect to the hot electrons, which disagrees with current hot electron stability theories and results of previous maximum-B experiments. A theoretical analysis using MHD theory shows that the compressibility can stabilize a plasma with a hollowness of 20--30% in the Constance B mirror well. 57 refs

  5. Prediction of hot-ductility of steels during continuous casting using artificial neural networks

    International Nuclear Information System (INIS)

    Liu, W.J.; Emadi, D.; Essadiqi, E.

    2000-01-01

    During continuous casting, transversal cracks can be developed due to tensile stress in temperature regions where the steel exhibits a low ductility. The cracking tendency during continuous casting depends on the steel chemistry and the casting parameters such as lubrication, mold type, secondary cooling and bending/unbending temperatures. To prevent cracking one needs to predict the hot-ductility of a material under continuous-casting conditions. However, hot-ductility is one of the poorly understood material behaviors and cannot be readily modeled using conventional techniques. In the present study, we used an alternative method, namely Artificial Neural Networks (ANN), to model the ductility of a steel under continuous casting conditions. A hot-ductility database was established based on published literature. Several standard three-layer ANN models were then trained using data randomly selected from the database. The outputs of the ANN models were subsequently compared with the remaining data in the database. The results indicate that ANN is a suitable modelling technique for hot-ductility prediction. (author)

  6. Generation and use of process maps for hot extrusion of seamless tubes for nuclear applications

    International Nuclear Information System (INIS)

    Vaibhaw, Kumar; Jha, S.K.; Saibaba, N.; Jayaraj, R.N.

    2009-01-01

    Full text: Hot extrusion is known as significant bulk deformation step in manufacturing of seamless tube production. Elevated temperature deformation carried out above the recrystallization temperature would enable imposition of large strains in single step. This deformation causes a significant change in the microstructure of the material and depends on extrusion process parameters such as temperature and strain rate (Ram speed). Basic microstructure developed at this deformation stage has significant bearing on the final properties of the material fabricated with subsequent cold working steps. Zirconium alloys and special nuclear grade austenitic stainless steels are two important groups of materials used as structural and core components in thermal and fast reactors world wide respectively. The properties of former alloy are very sensitive to the thermo mechanical fabrication steps initiated with hot extrusion due to their anisotropic deformation behaviour. However, nuclear grade austenitic stainless steels have many variants from their commercial grades in terms of micro and macro alloy chemistry. Factors such as these significantly affect the workability of the materials and require proper selection of extrusion parameters especially working temperature and extrusion speed plays a key role in the quality of the product. Modern developments in processing technology envisage the application of processing maps based on dynamic material model for selection of hot extrusion parameters. The present paper is aimed at bringing out significance of the map in selection of working domain with respect to the industrial process conditions for both groups of nuclear materials mentioned earlier. Developed process maps of certain alloys suggest use of extremely slow strain rate and low temperature extrusion which can not be achieved during bulk processing due to design of equipment and heat transfer constraints in industrial scale production. Attempts are made to highlight

  7. "It's still a great adventure" - exploring offshore employees' working conditions in a qualitative study.

    Science.gov (United States)

    Mette, Janika; Velasco Garrido, Marcial; Harth, Volker; Preisser, Alexandra M; Mache, Stefanie

    2017-01-01

    Despite the particular demands inherent to offshore work, little is known about the working conditions of employees in the German offshore wind industry. To date, neither offshore employees' job demands and resources, nor their needs for improving the working conditions have been explored. Therefore, the aim of this study was to conduct a qualitative analysis to gain further insight into these topics. Forty-two semi-structured telephone interviews with German offshore employees ( n  = 21) and offshore experts ( n  = 21) were conducted. Employees and experts were interviewed with regard to their perceptions of their working conditions offshore. In addition, employees were asked to identify areas with potential need for improvement. The interviews were analysed in a deductive-inductive process according to Mayring's qualitative content analysis. Employees and experts reported various demands of offshore work, including challenging physical labour, long shifts, inactive waiting times, and recurrent absences from home. In contrast, the high personal meaning of the work, regular work schedule (14 days offshore, 14 days onshore), and strong comradeship were highlighted as job resources. Interviewees' working conditions varied considerably, e.g. regarding their work tasks and accommodations. Most of the job demands were perceived in terms of the work organization and living conditions offshore. Likewise, employees expressed the majority of needs for improvement in these areas. Our study offers important insight into the working conditions of employees in the German offshore wind industry. The results can provide a basis for further quantitative research in order to generalize the findings. Moreover, they can be utilized to develop needs-based interventions to improve the working conditions offshore.

  8. [Psychosocial working conditions and mental health status of the German babyboomer generation].

    Science.gov (United States)

    Tophoven, S; Tisch, A; Rauch, A; Burghardt, A

    2015-04-01

    The baby boomers are the first to be available to the German labour market up to the age of 67. A crucial premise for a long working life is good health. However, there is evidence that psychosocial working conditions are related to health. More and more employees report psychosocial stress at work. In addition, mental illness has become one of the main reasons for the entry into disability pension. Against this background this study considers the relationship between psychosocial work conditions and mental health exemplarily for two birth cohorts of the German baby boomers. For the analysis of the assumed relationships data of the lidA study "lidA - leben in der Arbeit - German Cohort Study on Work, Age and Health" is used (N=6 057). Mental health is assessed by the mental health scale of the SF-12. In addition, the items and the scales quantitative job requirements, work pace and support from colleagues from the Copenhagen Psychosocial Questionnaire (COPSOQ) are used. As further control variables cohort affiliation, level of education, occupational status and partnership are considered. Multivariate analyses of the relations between quantitative job requirements, work pace and the experienced support from colleagues show significant relationship to mental health. The increasing frequency of the requirement to work quickly and increasing quantitative job demands are negatively associated to mental health. However, support of colleagues shows a positive relationship to mental health. These results are similarly observed for women and men. For the regarded group of the German babyboomers, employees at the threshold to higher working age, it is clearly shown that psychosocial working conditions are related to mental health. Since this group still has to work up to 18 years given a statutory retirement age of 67, psychosocial working conditions should rather be in the focus of occupational safety. © Georg Thieme Verlag KG Stuttgart · New York.

  9. Dose levels in the hot cells area ININ

    International Nuclear Information System (INIS)

    Torre, J. De la; Ramirez, J.M.; Solis, M.L.

    2004-01-01

    The Laboratory of Hot Cells (LCC) located in the National Institute of Nuclear Research (ININ) is an institution, it is an area where radioactive material is managed with different activity values, in function of its original design for 10,000 curies of Co-60. Managing this materials in the installation, it implies to measure and to analyze the dose levels that the POE will receive as well as the implementation of appropriate measures of radiological protection and radiological safety, so that that is completed settled down by the concept ALARA. In this work they are carried out mensurations of the levels of the dose to receive for the POE when managing radionuclides with maximum activities that can be allowed in function of the current conditions of the cells and an evaluation of the obtained results is made comparing them with the effective international norms as well as the application of the program of surveillance and radiological protection implemented for the development of the works that are carry out in the installation. (Author)

  10. The development on electric discharge machine for hot cell usage

    International Nuclear Information System (INIS)

    Ahn, Sang Bok; Kim, Young Suk; Park, Dae Kyu; Choo, Yong Sun; Oh, Wan Ho

    1998-06-01

    The electric discharge machine(EDM) was developed for hot cell usages in IMEF. This machine will be used to fabricate specimen directly from irradiated components from NPP's. The detailed contents are as follows; 1. Outline of electric discharge machine 2. Specimen shape to be fabricated by EDM 3. Technical specification to manufacture EDM 4. Installation EDM in hot cell 5. Optimum discharge conditions to fabricate specimens from CANDU tube. (author). 4 tabs., 20 figs

  11. Performance of desiccant air conditioning system with geothermal energy under different climatic conditions

    International Nuclear Information System (INIS)

    El-Agouz, S.A.; Kabeel, A.E.

    2014-01-01

    Highlights: • The performance of the hybrid air conditioning system is studied. • The influence of important operating parameters are estimated. • The ventilation, makeup and mix cycles are investigated at different climate. • The highest COP of the hybrid air conditioning system is 1.03. • The hybrid system provides a human thermal comfort at different climates. - Abstract: Energy saving still and continue a major seek in our life, due to the continuous increase in energy consumptions. So, a desiccant air conditioning system with geothermal energy is conducted in the current study. The thermal analysis of air conditioning system with its different components desiccant wheel, solar collector, heat exchanger, ground heat exchanger and water spray evaporative cooler is presented. Three different air conditioning cycles are simulated in the current study for different zones like: hot-dry zone, warm-dry zone, hot-humid zone and the warm-humid zone. The results show that the desiccant air conditioning system successfully provides a better thermal comfort condition in different climates. This hybrid system significantly decreases the supplied air temperature from 12.7 to 21.7 °C at different climate zones. When ω in , air and T Reg increasing, COP decreases and the ventilation cycle provides the better COP. The highest COP value of the desiccant air conditioning system is about 1.03 while the lowest value is about 0.15. The SHR of makeup cycle is higher than that ventilation cycle at warm and hot-humid zone and vice versa at warm and hot-dry zone. The highest SHR value of the desiccant air conditioning system is about 0.99 while the lowest value is about 0.2. The T sup,air , ω sup,air , COP and SHR isolines may easily be used for pre-evaluating of various cooling cycles in different climates. The hybrid system provides a human thermal comfort at different climates

  12. Women's Learning in Contract Work: Practicing Contradictions in Boundaryless Conditions

    Science.gov (United States)

    Fenwick, Tara

    2008-01-01

    The general rise in contractors, particularly among knowledge workers negotiating "boundaryless" employment conditions, has generated interest in the nature and forms of contract work. This article explores the learning of contract workers as they negotiate these conditions, with a focus on women. Drawing from a qualitative study of…

  13. [Capacity of extensive green roof to retain rainwater runoff in hot and humid region.

    Science.gov (United States)

    Liu, Ming Xin; Dai, Se Ping; Zhou, Tian Yang; Ruan, Lin; Zhang, Qiao Song

    2017-02-01

    The water logging has become the environmental problem of major cities with the sharp increase of impermeable urban pavement as the contributing cause. Abroad, the green roof has been widely used as a practical measure to intercept rainwater, yet the capacity of green roof to retain rainwater varies with climate conditions. As the hot and humid climate zone features high temperature, humidity and precipitation, it is meaningful to study the capacity of green roof to retain rainwater under such climatic condition. In this research, 3 plat forms were set up in Guangzhou in rainy and hot summer to test the capability of simple green roof to retain rainwater runoff, and the efficiency of green roof to retain rainwater under local climate conditions was worked out based on the meteorological observation and data measurement during the 13-month test period. The results showed that the simple green roof with a substrate thickness of 30, 50 and 70 mm could retain 27.2%, 30.9% and 32.1% of precipitation and reduce the average peak value by 18.9%, 26.2% and 27.7%, respectively. Given an urban built-up area of 1035.01 km 2 in Guangzhou and a roof area percentage of approximately 37.3% and assuming the green roofs with 30 mm-thick substrate were applied within the area, the light, medium and heavy rain could be delayed at 72.8%, 22.6% and 17.4%, respectively. Accordingly, the rainwater retained could reach up to 14317×10 4 m 3 . It suggested the great potential of the simple green roof in retaining rainwater. The research could serve as reference for the hot and humid climate zone to alleviate water logging and visualize sponge city construction.

  14. [Young French neurosurgeons: Working conditions and outlook].

    Science.gov (United States)

    Pommier, B; Manet, R; Gay, E; Vassal, F; Nuti, C; Hladky, J-P

    2015-10-01

    Due to the increase in the number of French neurosurgeon residents the neurosurgical workforce is changing. The main objective of this survey was to assess working conditions and perspectives for young French neurosurgeons. An on-line survey was sent to young French neurosurgeons based on a mailing-list (219 mail addresses of Residents and Fellows obtained during previous meetings). The form contained questions about career, amount of work, salary, quality of life, teaching and university work. We received 78 replies from January to March 2014. A total of 56% from fellows saying they had undergone difficulties in obtaining a fellowship, although 78% were satisfied. Fellows considered a private career more often than residents. Overall, young neurosurgeons were worried about future employment. Some 33% admitted contemplating a different career from one they originally wanted. The average weekly working time of 76.8 hours was deemed to be excessive. Security rests after overnight shifts were lacking or incomplete in 91% of cases. The work atmosphere was good overall (3.7/5), and so was the quality of life (3.2/5). Theoretical teaching was unsatisfactory (2.43/5) as well as the time allowed for academic work (approximately 1.58 half-days per month). However, practical teaching was considered rewarding (3.63/5). This study provides some guidance for upcoming reforms, and should be considered again at a later date to evaluate progress. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  15. Plasticity of low carbon steel in a hot state

    Energy Technology Data Exchange (ETDEWEB)

    Konovalov, V P; Rizol' , A I; Shram, N N [Ural' skij Nauchno-Issledovatel' skij Inst. Chernykh Metallov, Sverdlovsk (USSR)

    1977-07-01

    The hot ductility (in tapered-specimen piersing test and the in wedge-shaped specimen rolling test) is studied of the Armeo-type low carbon steel produced by vacuum induction and open hearth techniques. The variations of the chemical composition within specified ranges, particularly as regards sulphur, oxygen and the Mn/S ratio, have a marked effect on the processing ductility. The temperature range of brittle fracture and acceptable hot working reductions as functions of the chemical composition have been revealed.

  16. Plasticity of low carbon steel in a hot state

    International Nuclear Information System (INIS)

    Konovalov, V.P.; Rizol', A.I.; Shram, N.N.

    1977-01-01

    The hot ductility (in tapered-specimen piersing test and the in wedge-shaped specimen rolling test) is studied of the Armeo-type low carbon steel produced by vacuum induction and open hearth techniques. The variations of the chemical composition within specified ranges, particularly as regards sulphur, oxygen and the Mn/S ratio, have a marked effect on the processing ductility. The temperature range of brittle fracture and acceptable hot working reductions as functions of the chemical composition have been revealed

  17. Associations of psychosocial working conditions and working time characteristics with somatic complaints in German resident physicians.

    Science.gov (United States)

    Fischer, Nina; Degen, Christiane; Li, Jian; Loerbroks, Adrian; Müller, Andreas; Angerer, Peter

    2016-05-01

    Somatic complaints (SC) are highly prevalent in working populations and cause suffering and extensive health-care utilization. Adverse psychosocial working conditions as conceptualized in the Job Demand-Control-Support Model (JDC-S) and adverse working time characteristics (WTC) are potential risk factors. This combination is particularly common in hospital physicians. This study examines associations of JDC-S and WTC with SC in resident physicians from Germany. A cross-sectional study was conducted among 405 physicians at the end of residency training. SC were measured using the Giessen Subjective Complaints List (GBB-24) containing the sub-categories exhaustion, gastrointestinal, musculoskeletal, and cardiovascular complaints. Data on working conditions were collected by a self-report method for work analysis in hospitals (TAA-KH-S) and by questions on WTC (i.e., working hours). Multivariable stepwise regression analyses were applied. Workload showed the most pronounced relationship with all sub-categories of SC except gastrointestinal complaints. Job autonomy was not significantly related to any SC sub-category. Social support at work was inversely associated with all SC sub-categories except for cardiovascular complaints. Free weekends were associated with reduced SC except for exhaustion. Shift work was related to an increased SC total score and musculoskeletal complaints. Working hours showed no association with SC. In resident physicians, high workload and shift work are associated with increased SC, while social support at work and free weekends are associated with decreased SC. These insights may inform the development of preventive measures to improve the health of this professional group. Prospective studies are needed though to corroborate our findings.

  18. Microstructure of Sinter Deposit Formed at Hot Springs in West Sumatera

    Science.gov (United States)

    Putra, A.; Inanda, D. Y.; Buspa, F.; Salim, A. F.

    2018-03-01

    Sinter deposit emerged and spread at several hot springs in West Sumatera is divided into three types, they are full silica, half silica-carbonate and full carbonate. This work intends to investigate the characteristic of each type by its crystalline structure and morphology and its correlation to surface temperature. The research is focused on Sapan Maluluang hot spring (full silica), Garara hot spring (half silica-carbonate) and Bawah Kubang hot spring (full carbonate). Crystalline structure is analyzed by X-Ray Diffraction (XRD) methods, it showed that deposit from Sapan Maluluang has opal-A structure, Garara has opal-CT structure and Bawah Kubang has crystalline structure. The Scanning Electron Microscopy (SEM) methods is applied to describe its morphology surface, in which spherical, almost rounded and irregular textured was formed at each deposit, respectively. Surface temperature of hot spring also has given impact on deposit texture.

  19. The Hottest Hot Jupiters May Host Atmospheric Dynamos

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, T. M. [Department of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne (United Kingdom); McElwaine, J. N. [Planetary Science Institute, Tucson, AZ 85721 (United States)

    2017-06-01

    Hot Jupiters have proven themselves to be a rich class of exoplanets that test our theories of planetary evolution and atmospheric dynamics under extreme conditions. Here, we present three-dimensional magnetohydrodynamic simulations and analytic results that demonstrate that a dynamo can be maintained in the thin, stably stratified atmosphere of a hot Jupiter, independent of the presumed deep-seated dynamo. This dynamo is maintained by conductivity variations arising from strong asymmetric heating from the planets’ host star. The presence of a dynamo significantly increases the surface magnetic field strength and alters the overall planetary magnetic field geometry, possibly affecting star–planet magnetic interactions.

  20. Design Report for ACP Hot Cell Rear Door

    Energy Technology Data Exchange (ETDEWEB)

    Ku, J. H.; Kwon, K. C.; Choung, W. M.; Cho, I. J.; Kook, D. H.; Lee, W. K.; You, G. S.; Lee, E. P.; Park, S. W

    2005-12-15

    A hot-cell facility was constructed at the IMEF building for the demonstrate ACP process. ACP hot-cell consists of process cell and maintenance cell, and each cell has rear door. Since this facility was constructed at basement floor, all process materials, equipment and radioactive materials are take in and out through the rear door. Also, this door can be an access route of workers for the maintenance works. Therefore ACP hot-cell rear doors must maintain the radiation shielding, sealing, mechanical and structural safety. This report presents design criteria, design contents of each part and driving part. It was confirmed that the rear doors sufficiently maintain the safety through the structural analysis and shielding analysis. Also, it was confirmed that the rear doors were constructed as designed by the gamma scanning test after the installation.

  1. Design Report for ACP Hot Cell Rear Door

    International Nuclear Information System (INIS)

    Ku, J. H.; Kwon, K. C.; Choung, W. M.; Cho, I. J.; Kook, D. H.; Lee, W. K.; You, G. S.; Lee, E. P.; Park, S. W.

    2005-12-01

    A hot-cell facility was constructed at the IMEF building for the demonstrate ACP process. ACP hot-cell consists of process cell and maintenance cell, and each cell has rear door. Since this facility was constructed at basement floor, all process materials, equipment and radioactive materials are take in and out through the rear door. Also, this door can be an access route of workers for the maintenance works. Therefore ACP hot-cell rear doors must maintain the radiation shielding, sealing, mechanical and structural safety. This report presents design criteria, design contents of each part and driving part. It was confirmed that the rear doors sufficiently maintain the safety through the structural analysis and shielding analysis. Also, it was confirmed that the rear doors were constructed as designed by the gamma scanning test after the installation

  2. Performance Characteristics of Hero's Turbine Using Hot Water as a Working Fluid

    OpenAIRE

    FUJII, Terushige; OHTA, Jun-ichi; AKAGAWA, Koji; NAKAMURA, Toshi; ASANO, Hitoshi

    1992-01-01

    From the viewpoint of energy conservation and the development of new energy resources,it is important to utilize geothermal resources and waste heat from factories. Among energy conversion device,there is a radial outflow reaction turbine,i.e.,Hero's turbine. Performance characteristics of Hero's turbine are analytically and experimentally clarified for flashing expansion of initially subcooled hot water. It is found that: (a)there is an optimum number of revolutions at which maximum tubine e...

  3. ELIPGRID-PC: A PC program for calculating hot spot probabilities

    International Nuclear Information System (INIS)

    Davidson, J.R.

    1994-10-01

    ELIPGRID-PC, a new personal computer program has been developed to provide easy access to Singer's 1972 ELIPGRID algorithm for hot-spot detection probabilities. Three features of the program are the ability to determine: (1) the grid size required for specified conditions, (2) the smallest hot spot that can be sampled with a given probability, and (3) the approximate grid size resulting from specified conditions and sampling cost. ELIPGRID-PC also provides probability of hit versus cost data for graphing with spread-sheets or graphics software. The program has been successfully tested using Singer's published ELIPGRID results. An apparent error in the original ELIPGRID code has been uncovered and an appropriate modification incorporated into the new program

  4. Nitrogen cycling in Hot Spring Sediments and Biofilms (Invited)

    Science.gov (United States)

    Meyer-Dombard, D. R.; Burton, M. S.; Havig, J. R.; Shock, E.

    2010-12-01

    Over the past several decades, gene-targeted analyses have revealed that microbial communities in hydrothermal environments can be surprisingly diverse. However, we know shockingly little about basic ecological functions such as carbon and nitrogen cycling or community shifts over time, or environmental parameters such as growth criteria. Previous work has shown that carbon cycling in one hot spring in Yellowstone National Park [“Bison Pool”] and its associated runoff channel functions as a complex system. Analysis of carbon and nitrogen isotopes in biofilms across a temperature and chemical gradient at this location revealed that multiple autotrophic carbon fixation pathways are functioning in this system, and nitrogen fixation varies across the chemosynthetic/photosynthetic ecotone [1]. Further, sequencing of metagenomes from multiple locations at “Bison Pool” has indicated the presence of genes involved in carbon fixation [both phototrophic and autotrophic], and heterotrophy, as well as nitrogen fixation [2]. Studies from other Yellowstone locations have also found genetic evidence for carbon and nitrogen fixation [3-5]. The role of individual microbes in nitrogen cycling as environmental conditions vary over space and time is the focus of this study. Here, we explore the diversity of nifH [nitrogen fixation], nirK [nitrite reduction] and amoA [ammonia oxidation] genes across a variety of Yellowstone environments. Environmental nucleic acids were extracted, and the presence/absence of Bacteria and Archaea determined by PCR. In addition, PCR-directed screens reveal the presence or absence of the aforementioned functional genes, indicating genetic capacity for nitrogen cycling. We have examined the transition of genetic diversity and genetic capacity within sediments and biofilms at the chemosynthetic/photosynthetic ecotone in several hot springs spanning ranges of pH and geochemical conditions. By sampling across this ecotone, changes in the genetic

  5. [From 1878 to 2006 - working in hyperbaric conditions during tunnelling].

    Science.gov (United States)

    Le Péchon, Jean-Claude

    2006-01-01

    To review the impact of Paul Bert's researches on hyperbaric work in tunnelling, the status of the industry in 1878 is described. Mostly based on the application of Triger's machine it was used to mine coal below the water table or to dig foundations for bridges in rivers or close to rivers. The results and conclusions obtained by Paul Bert which are applicable in that particular field are listed. The major steps of research or remarkable achievements in construction between 1878 and 2006 are presented as well as the evolution of decompression tables. Improvement in safety and conditions of caisson workers has been continuous until the technical revolution resulting from the introduction and the development of tunnelling boring machines (TBM) in the late 80's. TBM technology has resulted in major changes in tunnel construction. Hyperbaric interventions have also changed completely since human operators no longer work in pressurized conditions. Only occasional inspections and repairs are carried out under pressure. Present performance in hyperbaric conditions are reported, and high pressures reached in the 2000's using saturation technology are described. The future of hyperbaric works is also discussed whether for very high pressure, or complete replacement of caisson workers in TBMs. These descriptions show that Paul Bert provides us with very clear directions to improve safety in hyperbaric conditions and that none of his recommendations were mistaken, most being still relevant.

  6. Hot-crack test for aluminium alloys welds using TIG process

    Directory of Open Access Journals (Sweden)

    Deschaux-beaume F.

    2010-06-01

    Full Text Available Hot cracking is a critical defect frequently observed during welding of aluminium alloys. In order to better understand the interaction between cracking phenomenon, process parameters, mechanical factors and microstructures resulting from solidification after welding, an original hot-cracking test during welding is developed. According to in-situ observations and post mortem analyses, hot cracking mechanisms are investigated, taking into account the interaction between microstructural parameters, depending on the thermal cycles, and mechanical parameters, depending on geometry and clamping conditions of the samples and on the thermal field on the sample. Finally, a process map indicating the limit between cracking and non-cracking zones according to welding parameters is presented.

  7. Sector surveys on working conditions : hotels and restaurants in the Netherlands

    NARCIS (Netherlands)

    Bossche, S.N.J. van den; Jettinghoff, K.; Houtman, I.L.D.

    2003-01-01

    The European Foundation for the Improvement of Living and Working Conditions has asked TNO Work & Employment to report on the quality of work and employment in the sector of Hotels & Restaurants in The Netherlands. Other research institutes were asked to do the same for the situation in the other

  8. A Study of Leadership Strategies and Their Impact on Teacher Working Conditions

    Science.gov (United States)

    Rosenbalm, Elizabeth M.

    2012-01-01

    Throughout this study, the researcher sought to find the key strategies needed to improve school culture and working conditions. These findings were measured by the 2010 and 2012 North Carolina Teacher Working Conditions Survey (NC TWCS) data, as well as staff focus-group dialogue at three selected schools. The participant groups consisted of an…

  9. EBSD study of purity effects during hot working in austenitic stainless steels

    International Nuclear Information System (INIS)

    El Wahabi, M.; Gavard, L.; Cabrera, J.M.; Prado, J.M.; Montheillet, F.

    2005-01-01

    The technique of electron back scattering diffraction (EBSD) is considered as a powerful instrument for the study of the microstructural changes during hot forming processes and gives the possibility to present the information in different ways (OIM, misorientation diagram and pole figures). The present work is focused on the observation by EBSD of the microstructure evolution during deformation at high temperature of three austenitic stainless steels: AISI-304H, AISI-304L and a high purity steel HP. The difference between the three steels is the content carbon and the presence of residual elements. To this aim compression tests were carried out at a constant strain rate of 0.001 s -1 and different temperatures. The study showed an increase of twin boundary fractions and a diminution of substructure (low angle densities boundaries) at increasing temperatures. On the other hand, increasing carbon content promotes lower twin boundary fractions and larger amounts of low angle boundaries. This effect can be explained by the reduction of grain boundary mobility caused by increasing carbon contents, which in turn reduces the migration rate and consequently the probability of twin boundary generation. Moreover, the increment of low angle boundaries with carbon content accelerates the twin character loss. It was also found that the dynamically recrystallized grain size decreased at increasing carbon content due to a typical drag effect. No important features on textures were found during DDRX

  10. Standing working posture compared in pregnant and non-pregnant conditions.

    Science.gov (United States)

    Paul, J A; Frings-Dresen, M H

    1994-09-01

    During pregnancy, an increase in body weight occurs together with changes in body weight distribution and in fit between body dimensions and workplace layout. These changes may cause alterations in working posture which may, in turn, have adverse consequences for the biomechanical load on the musculoskeletal system and so increase the risk of musculoskeletal disorders. Using photographic posture registration, the standing working posture was studied in 27 women during the last stage of pregnancy and after delivery (the experimental group). The women performed an assembly task while standing at various workplace layouts. The postural differences between the pregnant condition and the non-pregnant condition were studied and the effect of the various workplace layouts assessed. Ten non-pregnant controls were also studied twice to establish the effect of the time interval between the measuring occasions. We found that the women of the experimental group stood further from the work surface in the pregnant condition compared to the non-pregnant condition, the hips were positioned more backwards, and, in order to reach the tesk, they increased the flexion of the trunk, increased the anteflexion of the upper arms, and extended the arms more. At the workplace layout in which the work surface height was self-selected, the postural differences due to pregnancy were smallest or even absent, compared to the postural differences in the other workplace layouts studied. Ergonomists and workers in occupational health services should be alert to the consequences for the biomechanical load on the musculoskeletal system and the risk of development of health complaints caused by postural changes due to pregnancy. An adjustable workplace layout may prevent some problems.

  11. Nonplasmonic Hot-Electron Photocurrents from Mn-Doped Quantum Dots in Photoelectrochemical Cells.

    Science.gov (United States)

    Dong, Yitong; Rossi, Daniel; Parobek, David; Son, Dong Hee

    2016-03-03

    We report the measurement of the hot-electron current in a photoelectrochemical cell constructed from a glass/ITO/Al2 O3 (ITO=indium tin oxide) electrode coated with Mn-doped quantum dots, where hot electrons with a large excess kinetic energy were produced through upconversion of the excitons into hot electron hole pairs under photoexcitation at 3 eV. In our recent study (J. Am. Chem. Soc. 2015, 137, 5549), we demonstrated the generation of hot electrons in Mn-doped II-VI semiconductor quantum dots and their usefulness in photocatalytic H2 production reaction, taking advantage of the more efficient charge transfer of hot electrons compared with band-edge electrons. Here, we show that hot electrons produced in Mn-doped CdS/ZnS quantum dots possess sufficient kinetic energy to overcome the energy barrier from a 5.4-7.5 nm thick Al2 O3 layer producing a hot-electron current in photoelectrochemical cell. This work demonstrates the possibility of harvesting hot electrons not only at the interface of the doped quantum dot surface, but also far away from it, thus taking advantage of the capability of hot electrons for long-range electron transfer across a thick energy barrier. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Experimental Investigation of the Hot Water Layer Effect on Upward Flow Open Pool Reactor Operability

    International Nuclear Information System (INIS)

    Abou Elmaaty, T.

    2014-01-01

    The open pool reactor offers a high degree of reliability in the handling and manoeuvring, the replacement of reactor internal components and the suing of vertical irradiation channels. The protection of both the operators and the reactor hall environment against radiation hazards is considered a matter of interest. So, a hot water layer is implemented above many of the research reactors main pool, especially those whose flow direction is upward flow. An experimental work was carried out to ensure the operability of the upward flow open pool research reactor with / without the hot water layer. The performed experiment showed that, the hot water layer is produced an inverse buoyant force make the water to diffuse downward against the ordinary natural circulation from the reactor core. An upward flow - open pool research reactor (with a power greater than 20 M watt) could not wok without a hot water layer. The high temperature of the hot water layer surface could release a considerable amount of water vapour into the reactor hall, so a heat and mass transfer model is built based on the measured hot water layer surface temperature to calculate the amount of released water vapour during the reactor operating period. The effects of many parameters like the ambient air temperature, the reactor hall relative humidity and the speed of the pushed air layer above the top pool end on the evaporation rate is studied. The current study showed that, the hot water layer system is considered an efficient shielding system against Gamma radiation for open pool upward flow reactor and that system should be operated before the reactor start up by a suitable period of time. While, the heat and mass transfer model results showed that, the amount of the released water vapour is increased as a result of both the increase in hot water layer surface temperature and the increase in air layer speed. As the increase in hot water layer surface temperature could produce a good operability

  13. Experimental Investigation of the Hot Water Layer Effect on Upward Flow Open Pool Reactor Operability

    International Nuclear Information System (INIS)

    Abou Elmaaty, T.

    2015-01-01

    The open pool reactor offers a high degree of reliability in the handling and manoeuvring, the replacement of reactor internal components and the swing of vertical irradiation channels. The protection of both the operators and the reactor hall environment against radiation hazards is considered a matter of interest. So, a hot water layer implemented above many of the research reactors main pool, especially those whose flow direction is upward flow. An experimental work was carried out to ensure the operability of the upward flow open pool research reactor with / without the hot water layer. The performed experiment showed that, the hot water layer produced an inverse buoyant force making the water to diffuse downward against the ordinary natural circulation from the reactor core. An upward flow-open pool research reactor (with a power greater than 20 Mw) could not wok without a hot water layer. The high temperature of the hot water layer surface could release a considerable amount of water vapour into the reactor hall, so a heat and mass transfer model is built based on the measured hot water layer surface temperature to calculate the amount of released water vapour during the reactor operating period. The effects of many parameters like the ambient air temperature, the reactor hall relative humidity and the speed of the pushed air layer above the top pool end on the evaporation rate is studied. The current study showed that, the hot water layer system is considered an efficient shielding system against gamma radiation for open pool upward flow reactor and that system should be operated before the reactor start up by a suitable period of time. While, the heat and mass transfer model results showed that, the amount of the released water vapour is increased as a result of both the increase in hot water layer surface temperature and the increase in air layer speed. As the increase in hot water layer surface temperature could produce a good operability conditions from

  14. Birth, life and death of hot nuclei

    International Nuclear Information System (INIS)

    Suraud, E.; Tamain, B.; Gregoire, C.

    1989-01-01

    Intermediate energy heavy-ions (10-100 MeV/u) are the most powerful tool to study hot nuclear matter properties. In this paper we give a review of experimental and theoretical works which support this statement. The first challenge is to achieve hot nuclei formation. The second one is to study their properties. The formation step is governed by the relative influence of nucleon-nucleon collisions and mean field effects. Fundamental quantities such as excited matter decay time, thermalization time, relaxation time for collective modes are of major importance and are compared with typical collision times. It appears that semi-classical theories are able to give a reasonable description of the collision and that they are a good guide for defining further experiments. We show how it has been possible to experimentally establish that very hot equilibrated nuclei are really formed. Their decay properties are not basically different from decay properties at lower bombarding energy. However specific channels are open: in that sense, we take stock of the multifragmentation process. Moreover, compression effects may be an important feature of this energy range. Future studies will involve heavier projectiles around 30-50 MeV/u. They will be the best probe for hot and compressed nuclear matter studies

  15. Determination of the heating temperature of potholes surface on road pavement in the process of repairs using hot asphalt concrete mixes

    Directory of Open Access Journals (Sweden)

    Giyasov Botir Iminzhonovich

    2014-12-01

    Full Text Available In the process of roads construction the necessary transport and operational characteristics should be achieved, which depend on the quality of the applied, material and technologies. Under the loads of transport means and the influence of weather conditions on the road pavement deformations and destructions occur, which lead to worsening of transport and operational characteristics, decrease of operational life of the road and they are often the reason of road accidents. According to the data of the Strategic Research Center of "Rosgosstrah" more than 20 % of road accidents in Russia occur due to bad quality of road pavement. One of the main directions in traffic security control and prolongation of operational life for road pavement of non-rigid type is road works, as a result of which defects of pavement are eliminated and in case of timely repairs of high quality the operational life of the road increases for several years. The most widely used material for non-rigid pavement repairs is hot road concrete mixes and in case of adherence to specifications they provide high quality of works. The authors investigate the problems of hot asphalt concrete mixes for repairs of road surfaces of non-rigid type. The results of the study hot asphalt concrete mix’s temperature regimes are offered in case of repair works considering the temperature delivered to the work site and the ambient temperature depending on the type of mix and class of bitumen.

  16. Hot mechanical behaviour of dispersion strengthened Cu alloys

    International Nuclear Information System (INIS)

    Garcia G, Jose; Espinoza G, Rodrigo; Palma H, Rodrigo; Sepulveda O, Aquiles

    2003-01-01

    This work is part of a research project which objective is the improvement of the high-temperature mechanical properties of copper, without an important decrease of the electrical or thermal conduction properties. The general hypothesis is that this will be done by the incorporation of nanometric ceramic dispersoids for hindering the dislocation and grain boundaries movement. In this context, the object of the present work is the study of the resistance to hot deformation of dispersion-strengthened copper alloys which have prepared by reactive milling. Two different alloys, Cu-2,39wt.%Ti-0.56wt.%C and Cu-1.18wt.%Al, were prepared so as obtain a copper matrix reinforced with nanometric TiC y Al 2 O 3 particles with a nominal total amount of 5 vol.%. The particles were developed by an in-situ formation process during milling. The materials were prepared in an attritor mill, and consolidated by extrusion at 750 o C, with an area reduction rate of 10:1. The resistance to hot deformation was evaluated by hot compression tests at 500 and 850 o C, at initial strain rates of 10 -3 and 10 -4 s-1. To evaluate the material softening due temperature, annealing at 400, 650 y 900 o C during 1h were applied; after that, hardness was measured at room temperature. Both studies alloys presented a higher resistance to hot deformation than pure copper, with or without milling. Moreover, the Cu-Ti-C alloy presented a mechanical resistance higher than that of the Cu-Al one. Both alloys presented strain-stress compression curves with a typical hot-work shape: an initial maximum followed by a stationary plateau. The Cu-Ti-C alloy had a higher hardness and did not present a hardness decay even after annealings at the higher temperature imposed (900 o C), while the Cu-Al alloy did exhibit a strong decay of hardness after the annealing at 900 o C. The best behaviour exhibited by the Cu-Ti C alloy, was attributed to the formation of a major quantity of dispersoids that in the Cu-Al alloy. In

  17. [Job perception, work conditions and burnout in emergency workers].

    Science.gov (United States)

    Argentero, P; Setti, I

    2008-01-01

    The psychological syndrome of burnout in the helping professions has received much attention. Numerous studies have investigated the risk factors involved and their negative consequences for those whose work brings them into contact with people in states of physical and psychological suffering. In particular, emergency workers like police officers, fire-fighters and ambulance personnel who witness critical events are at high risk of developing negative psychological effects. Despite the ample literature investigating burnout in single emergency worker categories, currently there are few studies that deal with this topic from a comparative point of view, i.e. comparing the conditions of wellbeing of emergency workers across different organizations. The main aim of this pilot study was to compare different categories of emergency workers (83 ambulance workers, 42 operators of 118--free local health emergency service, 112 fire-fighters and 61 police officers) in order to identify which present a condition of wellbeing and which, on the contrary, may foster the burnout syndrome. Subjects were administered the Organizational Checkup System (OCS) to evaluate subjects' risk of burnout and their perception of their own work role and of their organizational environment. The second aim of this paper was to compare subjects on the basis of the main socio-demographic characteristics (gender, age and work seniority) in order to verify the presence of meaningful differences due, not just to the specific work category, but also to different subjective variables. The findings showed a condition of wellbeing, e.g. a high level of Energy and Involvement, in police officers as compared to 118 operators, who instead displayed a psychological state of burnout. Concerning the perception of organizational characteristics, fire-fighters displayed significant Control on tasks performed and good Social Integration in their work team. Furthermore, we noted the alignment of personal and

  18. Attitudes toward working conditions: are European Union workers satisfied with their working hours and work-life balance?

    Science.gov (United States)

    Matilla-Santander, Nuria; Lidón-Moyano, Cristina; González-Marrón, Adrián; Bunch, Kailey; Martín-Sánchez, Juan Carlos; Martínez-Sánchez, José M

    2017-12-23

    To describe the satisfaction with working hours and satisfaction with work-life balance and their association in the European Union (EU-28). This is a cross-sectional study based on data from the Flash Eurobarometer 398 among workers of the EU-28 from 2014 (n=13,683). We calculated percentages and their 95% confidence intervals (95%CI). We also applied a multi-level generalised linear model using the Poisson family, to calculate the adjusted prevalence ratios (aPR) of satisfaction with work-life balance based on working hours. All analyses were stratified by individual, employment and welfare regime country classification. The satisfaction with working hours and work-life balance was 80.62% and 74.48%, respectively, and was significantly higher among women. The highest percentages of satisfaction were found in the Nordic welfare regime countries (90.2% and 85.3%, respectively). There was a statistically significant association between satisfaction with working hours and work-life balance (aPR: 2.63; 95%CI: 2.28-3.04), and the magnitude of the association differed in individual, employment and welfare regime country classifications. The main reasons declared for dissatisfaction were "excessive working hours" (48.7%), "shift work" (27.9%), and "inability to influence the work schedule" (28.3%). Differences were observed according to sex and type of welfare regime. The differences found in the association between satisfaction with work-life balance and working hours according to sociodemographic characteristics and welfare regime show that there are inequalities in the working conditions in the EU countries. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Effect of microalloying elements (Nb, V and Ti) on the hot flow behavior of high-Mn austenitic twinning induced plasticity (TWIP) steel

    International Nuclear Information System (INIS)

    Reyes-Calderón, F.; Mejía, I.; Boulaajaj, A.; Cabrera, J.M.

    2013-01-01

    This research work studies the effect of microalloying elements such as Nb, V and Ti on the hot flow behavior of high-Mn austenitic TWIP steel. For this purpose, isothermal uniaxial hot compression tests were carried out at three temperatures (900, 1000 and 1100 °C) and four constant strain rates (10 −1 , 10 −2 , 10 −3 and 10 −4 s −1 ). Experimental results revealed that hot flow curves of microalloyed TWIP steels show single peak curves for all test conditions. Results are discussed in terms of the peak stress (σ p ) and peak strain (ε p ) and its dependence on the strain rate (ε) and temperature. The addition of microalloying elements such as Nb, V and Ti in TWIP steels generates a slight increase in the σ p value, and Ti microalloyed TWIP steel exhibits the highest σ p value. Hot deformed microstructures were analyzed by the Electron Back-Scattering Diffraction Technique (EBSD). The most important results of the austenitic recrystallized grain refinement were obtained for V and Ti microalloyed TWIP steels.

  20. Organizational commitment, work environment conditions, and life satisfaction among Iranian nurses.

    Science.gov (United States)

    Vanaki, Zohreh; Vagharseyyedin, Seyyed Abolfazl

    2009-12-01

    Employee commitment to the organization is a crucial issue in today's health-care market. In Iran, few studies have sought to evaluate the factors that contribute to forms of commitment. The aim of this study was to investigate the relationship between nurses' organizational commitment, work environment conditions, and life satisfaction. A cross-sectional design was utilized. Questionnaires were distributed to all the staff nurses who had permanent employment (with at least 2 years of experience in nursing) in the five hospitals affiliated to Birjand Medical Sciences University. Two hundred and fifty participants returned completed questionnaires. Most were female and married. The correlation of the total scores of nurses' affective organizational commitment and work environment conditions indicated a significant and positive relationship. Also, a statistically significant relationship was found between affective organizational commitment and life satisfaction. The implementation of a comprehensive program to improve the work conditions and life satisfaction of nurses could enhance their organizational commitment.