WorldWideScience
1

Influence of plasma nitriding on fatigue strength and fracture of a B-Mn steel  

Energy Technology Data Exchange (ETDEWEB)

The first part of a systematic investigation is presented of surface treatments affecting the fatigue behavior of smooth and notched quenched and tempered (Q and T) specimens made of a B-Mn SS2131 ({approx}AISI 15B21H) steel. In this part, the effects of plasma nitriding (nitriding temperature=480 C, time=24 h) on the fatigue strength and notch sensitivity were investigated. Constant stress amplitude plane reversed bending fatigue tests (R=-1) at 47 Hz were conducted using cylindrical plasma nitriding (PN) and Q and T steel specimens with K{sub t}=1.05 and 1.7. The compound layer was found to consists of {epsilon}-phase and {gamma}`-phase. S-N curves show that plasma nitriding improves the fatigue limit by 53 and 115% of Q and T smooth and notched specimens, respectively. The fatigue strength of smooth specimens is improved through the whole ...

1998-02-01

2

Metallurgical instabilities during the high temperature low cycle fatigue of nickel-base superalloys  

Energy Technology Data Exchange (ETDEWEB)

In this letter, examples of microstructural instabilities that can significantly affect the low crystal fatigue (LCF) life are pointed out.

1983-01-01

3

In situ observation of fatigue crack retardation in banded ferrite?pearlite microstructure due to crack branching  

British Library Electronic Table of Contents (United Kingdom)

This paper reports the results of in situ observation of fatigue crack growth in a ferrite?pearlite steel. Stress intensity factor range (?K) decreasing/increasing and constant-?K fatigue tests have been carried out. In banded pearlite orientation, intense crack branching was observed which leads to fatigue crack retardation. Crack closure during the test was monitored to understand the fatigue crack growth behaviour.

2006-01-01

4

The Effect of Applied Pressure During Feeding of Critical Cast Aluminum Alloy Components With Particular Reference to Fatigue Resistance  

Energy Technology Data Exchange (ETDEWEB)

the medium to long freezing range alloys of aluminum such as A356, A357, A206, 319 for example are known to exhibit dispersed porosity, which is recognized as a factor affecting ductility, fracture toughness, and fatigue resistance of light alloy castings. The local thermal environment, for example, temperature gradient and freezing from velocity, affect the mode of solidification which, along with alloy composition, heat treatment, oxide film occlusion, hydrogen content, and the extent to which the alloy contracts on solidification, combine to exert strong effects on the porosity formation in such alloys. In addition to such factors, the availability of liquid metal and its ability to flow through the partially solidified casting, which will be affect by the pressure in the liquid metal, must also be considered. The supply of molten metal will thus be ...

2003-06-30

5

Evaluation of the corrosion and corrosion-mechanical damage of the primary piping material of WWER-440/V213c units in operating conditions  

International Nuclear Information System (INIS)

The sensitivity of the primary circuit material was examined at the Mochovce and Dukovany NPPs. No significant sensitivity of the base material or the weld metal to the initiation of corrosion cracking was observed. Thermal aging was found to accelerate significantly the corrosion fatigue kinetics in the material of the heat affected zone. The threshold values of the double amplitudes of the stress intensity factor were below 8 MPa/m"2 for the materials examined, with a cycle asymmetry coefficient of 0.65. The tests revealed no appreciable sensitivity to general corrosion, pitting, or intergranular corrosion. (J.B.). 7 tabs., 26 figs., 11 refs.

6

Effect of protective coatings on the high-temperature fatigue of heat-resistant alloys  

Energy Technology Data Exchange (ETDEWEB)

The fatigue properties of EP539LM alloy with an Al-Nb-Si fused slurry coating and a Co-Cr-Al-Y electron-beam coating are investigated experimentally in vacuum and in air at 900 C. It is found that the protective coatings reduce the fatigue life of the specimens both in vacuum and in air, with the electron-beam coating affecting the fatigue life of the alloy to a lesser degree than the fused slurry coating. The negative effect of the coatings on the fatigue life of the alloy is attributed largely to the properties of the coating material. 7 references.

1986-08-01

7

Final report on low-cycle fatigue and creep-fatigue testing of salt-filled alloy 800 specimens  

Energy Technology Data Exchange (ETDEWEB)

Uniaxial low-cycle fatigue and creep-fatigue tests have been carried out on hollow alloy 800 specimens that were either filled with air or with a molten mixture of sodium nitrate, potassium nitrate and an oxidizer. Low-cycle fatigue tests were carried out at 1200/sup 0/F and 650/sup 0/F by cycling the strain continuously between equal mangitude of tensile and compressive values at a rate of 4 x 10/sup -3/sec/sup -1/ until failure. The creep-fatigue tests were carried out at 1200/sup 0/F. The loading cycle differed from that of low-cycle fatigue testing only in the imposition of a hold at the peak compressive strain in each cycle. Cracks always initiated on the inner surface of the hollow specimen, and therefore, corrosive effects on crack propagation and initiation were controlled by the environment within the specimen cavity. In common with tests carried out earlier on steam-filled ...

1982-05-01

8

Depression and chronic fatigue in the patient with chronic pain.  

Science.gov (United States)

Chronic benign pain is commonly associated with chronic fatigue and depression. Depression and chronic fatigue syndrome are also associated with each other and often include pain. Psychologic factors are prominent in these conditions, and they may share neurobiologic factors as well. Management requires separately addressing each component of patients' distress and usually includes physical rehabilitation, education, administration of nonhabituating medications and often counseling. Depression may be a favorable prognostic sign, as it suggests a treatable condition and provides incentive for recovery. PMID:1876618

1991-06-01

9

Effects of size and spacing of uniformly distributed pearlite particles on fatigue crack growth behavior of ferrite pearlite steels  

British Library Electronic Table of Contents (United Kingdom)

Fatigue crack growth tests of three ferrite-pearlite steels with different size and spacing of pearlite particles, which were uniformly distributed in the ferrite matrix, were carried out to investigate the effect of microstructure on fatigue crack growth behavior in the Paris regime. The fatigue crack growth rates for the three materials did not coincide with each other, even when the crack growth curves were arranged by the effective stress intensity factor range. From in situ observations, crack tip stress shielding phenomena, such as interlocking and branching, were found on the crack wake, which enhanced fatigue crack growth resistance. A small size and spacing of pearlite particle seemed to induce small but frequent crack deflections, which resulted in crack closure phenomena. On the...

2010-01-01

10

Load conditions and corrosion fatigue crack propagation behavior of high performance steel under seawater environment  

Energy Technology Data Exchange (ETDEWEB)

An effect of load conditions on Corrosion Fatigue Crack Propagation (CFCP) behavior of High Performance Steel (HPS) under seawater environment was investigated. Fatigue crack propagation tests under several load conditions including stress ratio and load frequency were conducted in air and 3.5% NaCl solution environments. Corrosion/fatigue ratio factor, C/F, particularly was defined to analyze the effect of such conditions. As shown in the results, a decrease of load ratio and frequency leads to an increase of C/F factor. Consequently, under lower loading frequency and stress ratio, the seawater condition causes much more significant effect on CFCP behavior of HPS.

2009-07-01

11

Effect of the fabrication process on fatigue performance of U3Si2 fuel plate with sandwich structure  

Science.gov (United States)

U3Si2 Al fuel plate is one of the dispersion fuel structure materials recently developed and widely used in research reactors. The mechanical properties of this structural material, especially the fatigue performance, are strongly dependent on its fabrication process. To investigate the effects of these processing technologies, the fatigue tests for the different specimens were carried out. The S N curves indicate that the fabrication processing technologies of U3Si2 fuel plate, such as the addition of U3Si2 particles into aluminum powder to form the fuel meat, holding and rolling the processes of meat and cladding of 6061-Al alloy, plays an important role in improving the mechanical properties and fatigue performance of this fuel plate. In addition, some factors that influence the crack initiation and propagation are summarized based on the fatigue images that are in situ ...

2005-06-01

12

Fatigue of magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

Magnesium alloys show a high specific strength and are therefore increasingly used for light-weight constructions in transportation industry.{sup [1,2]} To predict the behaviour of the material under the influence of cyclic loading it is vital to understand the fatigue behaviour of magnesium alloys. Only when understood properly, it is possible to fully apply the potential weight reduction by using magnesium alloys. A very important aspect in fatigue of magnesium alloys is the influence of a corrosive media and elevated temperatures, of which both are relevant in automotive applications. These two factors tend to have deleterious effects on magnesium alloys and therefore also have to be considered in investigations on the fatigue behaviour of magnesium alloys. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

2004-05-01

13

Research and Service Experience with Environmentally-Assisted Cracking in Carbon and Low-Alloy Steels in High-Temperature Water  

Energy Technology Data Exchange (ETDEWEB)

The most relevant aspects of research and service experience with environmentally-assisted cracking (EAC) of carbon (C) and low-alloy steels (LAS) in high-temperature (HT) water are reviewed, with special emphasis on the primary pressure boundary components of boiling water reactors (BWRs). The main factors controlling the susceptibility to EAC under light water reactor (LWR) conditions are discussed with respect to crack initiation and crack growth. The adequacy and conservatism of the current BWRVIP-60 stress corrosion cracking (SCC) disposition lines (DLs), ASME III fatigue design curves, and ASME XI reference fatigue crack growth curves, as well as of the GE EAC crack growth model are evaluated in the context of recent research results. The operating experience is summarized and compared to the experimental/mechanistic background knowledge. Finally, open questions and possible topics for further research are identified. ...

2005-11-15

15

Inhomogeneity of mechanical and fatigue properties of Al-Li alloys extrusions  

Energy Technology Data Exchange (ETDEWEB)

Aluminium-lithium extrusions possess high inhomogeneity of properties across the cross section. Mechanical properties such as R{sub p0,2}, R{sub m} and hardness, but also fatigue properties, change their value in dependence with the cross section position where test specimens were taken. Positions, where extreme values of properties are measured, are characteristic for a given extrusion shape. The positions with different properties have different structure and texture. Properties and structure inhomogeneity is affected mainly by extrusion shape and heat treatment parameters. (orig.)

1996-12-01

16

Slip and fatigue crack formation processes in an #alpha#/#beta# titanium alloy in relation to crystallographic texture on different scales  

International Nuclear Information System (INIS)

The purpose of this experimental study is to investigate the micromechanical fatigue behavior, in terms of slip nature and preferential cracking sites, of a commercial #alpha#/#beta#-forged Ti-6Al-4V alloy. Electron backscattering diffraction is extensively used to identify the deformation (prismatic, basal, pyramidal slip) and crack formation modes activated by fatigue at the surface of several hundred primary #alpha# nodules. Some fatal crack formation sites are also characterized. Cracking in basal planes is identified as the most critical damage mode leading to fracture. An explanation is proposed which involves the resolved shear stress, taking into account the Schmid factor and the normal stress in relation to the elastic anisotropy of the #alpha#-phase. Finally, the spatial distribution of the secondary cracks is analyzed according to the crystallographic textures (macrozones) present on a mesoscopic scale in the ...

2008-09-01

17

S-N curves for welded tubular joints  

Energy Technology Data Exchange (ETDEWEB)

The objective of the project was to develop a welded tubular joint database to assess the fatigue design curves (X and X{prime}) in the American Petroleum Institute design code (API RP2A). Changes in the curve-fitting method and screening criteria (primarily the exclusion of the very thin tubular joints) produced results different from those reported previously. The current results show that the X and X{prime} curves are too conservative and that a new curve should be adopted. The Department of Energy T{prime} curve was found to be consistent with the screened tubular joint air data and is recommended for use in API RP2A. The weldment size effect exponent (n) of 0.25 in the current version of API RP2A was found to be too small, and a higher value of 0.30 consistent with the Department of Energy recommendations is recommended. The fatigue test results for tubular joints tested in air and tubular joints tested in sea water with cathodic ...

1995-12-31

18

Effects on fatigue life of gate valves due to higher torque switch settings during operability testing  

Energy Technology Data Exchange (ETDEWEB)

Some motor operated valves now have higher torque switch settings due to regulatory requirements to ensure valve operability with appropriate margins at design basis conditions. Verifying operability with these settings imposes higher stem loads during periodic inservice testing. These higher test loads increase stresses in the various valve internal parts which may in turn increase the fatigue usage factors. This increased fatigue is judged to be a concern primarily in the valve disks, seats, yokes, stems, and stem nuts. Although the motor operators may also have significantly increased loading, they are being evaluated by the manufacturers and are beyond the scope of this study. Two gate valves representative of both relatively weak and strong valves commonly used in commercial nuclear applications were selected for fatigue analyses. Detailed dimensional and test data were available for both valves ...

1995-12-01

19

Pacification: The Overall Strategy in South Vietnam  

Science.gov (United States)

... implementation." 4 1 Factors Affecting Rural Construction. Two new factors profoundly modify today's pacification equa- tion. ...

1966-04-22

20

Occupational Asthma: Etiologies and Risk Factors  

UK PubMed Central (United Kingdom)

The purpose of this article is to critically review the available evidence pertaining to occupational, environmental, and individual factors that can affect the development of occupational asthma (OA)....Full Text Available

2011-07-01

21

Factors affecting the aggregation of Actinomyces naeslundii during growth and in washed cell suspensions.  

UK PubMed Central (United Kingdom)

Various factors affecting the aggregation of Actinomyces naeslundii strain 12104 were studied. When the pH of glucose-supplemented growth medium fell below 5.5, the cells aggregated and formed microbial...Full Text Available

1978-09-01

22

Factors affecting birth weight in sheep: maternal environment  

UK PubMed Central (United Kingdom)

Knowledge of factors affecting variation in birth weight is especially important given the relationship of birth weight to neonatal and adult health. The present study utilises two large contemporary...Full Text Available

2007-01-01

23

Microstructure/Mechanical property relationships in bar products of Beta-C trademark (Ti-3Al-8V-6Cr-4Mo-4Zr)  

International Nuclear Information System (INIS)

Beta-C trademark is a metastable beta titanium alloy which can be heat treated to achieve a good combination of properties such as tensile strength, fatigue strength, ductility and toughness, such as needed in aircraft fasteners. Variations in hot and cold processing parameters and solution heat treatment can affect the resultant grain structure which in turn affects subsequent aging response and mechanical properties. Several processing/heat treating routes on round bar are explored in this study to determine the effects on microstructure and various mechanical properties.

1993-02-21

24

Factors Affecting the Environmental Stability of Laminates,  

Science.gov (United States)

... The moisture content-dimension relationship of two laminate components, phenolic core and melamine overlay, are compared. (Author, modified). ...

1967-02-08

25

Creep and fatigue of alloy 800 in helium  

International Nuclear Information System (INIS)

Proposals for use of Alloy 800 as a H.T.R. boiler material have prompted studies of its creep and high temperature fatigue properties in impure helium with comparative tests in air. In impure helium, as expected in a H.T.R., reactions of potential importance are selective oxidation (of chromium, aluminium and titanium) and possibly carburisation from carbon monoxide or methane. In air, general oxidation will occur, possibly accompanied by nitridation. The effects of these reactions will depend on specimen geometry and the nature of the deformation. Two important possibilities are: (i) that environment affects the structure and properties of a surface zone of material undegoing uniform deformation (this may modify creep rate and crack nucleation); and (ii) that environment affects behaviour of a small region (e.g. at the root of a notch or ahead of a crack) in a specimen undergoing non-uniform deformation (this will modify ...

26

Analysis on Correlation between AE Parameters and Stress Intensity Factor using Principal Component Regression and Artificial Neural Network  

Energy Technology Data Exchange (ETDEWEB)

The aim of this study is to develop the methodology which enables to identify the mechanical properties of element such as stress intensity factor by using the AE parameters. Considering the multivariate and nonlinear properties of AE parameters such as ringdown count, rise time, energy, event duration and peak amplitude from fatigue cracks of machine element the principal component regression(PCR) and artificial neural network(ANN) models for the estimation of stress intensity factor were developed and validated. The AE parameters were found to be very significant to estimate the stress intensity factor. Since the statistical values including correlation coefficients, standard mr of calibration, standard error of prediction and bias were stable, the PCR and ANN models for stress intensity factor were very robust. The performance of ANN model for unknown data of stress intensity ...

2001-02-15

27

Environmentally assisted cracking in light water reactors. Semiannual report, October 1993--March 1994. Volume 18  

International Nuclear Information System (INIS)

This report summarizes work performed by Argonne National Laboratory (ANL) on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) during the six months from October 1993 to March 1994. EAC and fatigue of piping, pressure vessels, and core components in LWRs are important concerns in operating plants and as extended reactor lifetimes are envisaged. Topics that have been investigated include (a) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels, (b) EAC of wrought and cast austenitic stainless steels (SSs), and (c) radiation-induced segregation and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS after accumulation of relatively high fluence. Fatigue tests have been conducted on A302-Gr B low-alloy steel to verify whether the current predictions of modest decreases of fatigue life in simulated ...

2007-09-01

28

Examples of damaged aircraft engines; Beispiele fuer Schaeden an Flugtriebwerken  

Energy Technology Data Exchange (ETDEWEB)

Some of the smaller sports- und travel aircrafts are still propelled by piston engines. The first part of the article looks into some characteristic damage incidents that occur in aircraft engines. Not surprisingly, vibration fatigue failure happens most frequently. Apart from technical faults it is surprisingly lack of fuel that accounts for the high incidence of engine failure (one third). Flight turbines occasionally fail due to vibration fatigue of component parts. Added to this thermal fatigue cracks and damage due to overheating may occur in a gas turbine while the compressor parts may be affected by corrosion. (orig.) [German] Ein erheblicher Teil der kleineren Sport- und Reiseflugzeuge ist auch heute noch mit Kolbentriebwerken ausgestattet. Im ersten Teil des Aufsatzes werden daher einige charakteristische Schaeden an Flugmotoren vorgestellt. Als Versagensart dominiert erwartungsgemaess der ...

1998-07-01

29

Effects of extreme pressure additive chemistry on rolling element bearing surface durability  

Energy Technology Data Exchange (ETDEWEB)

Lubricant additives have been known to affect rolling element bearing surface durability for many years. Tapered roller bearings were used in fatigue testing of lubricants formulated with gear oil type additive systems. These systems have sulfur- and phosphoruscontaining compounds used for gear protection as well as bearing lubrication. Several variations of a commercially available base additive formulation were tested having modified sulfur components. The variations represent a range of ''active'' extreme pressure (EP) chemistries. The bearing fatigue test results were compared with respect to EP formulation and test conditions. Inner ring near-surface material in selected test bearings was evaluated on two scales: the micrometer scale using optical metallography and the nanometer scale using transmission electron microscopy (TEM). Focused-ion beam (FIB) techniques were used for TEM ...

2007-08-01

30

Crack growth in welded turbine materials at elevated temperatures  

International Nuclear Information System (INIS)

Due to thermal gradients and load changes steam-turbine casings suffer combined creep-fatigue loading. Creep and fatigue portions depend on service conditions. Special interest is focused on the behaviour of creep-fatigue cracks, originated from potential defects due to construction and manufacturing weldments, on residual lifetime assessment. The project deals with the crack-growth behaviour at 530deg C and r.t. of welded and unwelded heat-resistant cast steels: 1% CrMoV-cast (GS-17 CrMoV 5 11, two melts: low and high V-content) and 12% CrMoV-cast (G-X 22 CrMoV 12 1). The crack planes of CT-specimens investigated, taken from manual arc-welded plates, were situated in the heat-affected zone (HAZ). The fatigue, creep and combined creep-fatigue crack-growth behaviour was investigated by means of low-frequency (0.5 and 0.05 Hz) tests, holding-time (20 min) tests ...

1989-12-01

31

Development of risk benefit structural design method for innovative nuclear plants II, fatigue crack growth model  

International Nuclear Information System (INIS)

In order to develop competitive and reliable nuclear power generation systems, development of innovative structural design methods is indispensable and risk-based design approach based on the assessment of failure probability is being developed. Fatigue is commonly considered as an important contributor to failure probability in many components of reactor systems and its assessment gives a large influence on total reliability of the plants. In order to assess its effect on the reliability, propagation of cracks needs to be evaluated as well as their initiation and pre-existence probability. As a part of new design approach, efforts are being taken to develop a simplified estimation method for fatigue crack growth under cyclic application of thermal and thermo-mechanical loading. A simplified estimation method of J-integral based on reference stress method and elastic follow-up factor was developed based on many finite ...

2005-05-01

32

Osteocyte death and hip fracture.  

Science.gov (United States)

The viability of osteocytes can be demonstrated in sawn decalcified sections of bone by their lactate dehydrogenase activity. In the cancellous bone of the femoral head, the proportion of lacunae containing viable osteocytes decreased from 88 +/- 7% (mean +/- SD) at 10-29 years to 58 +/- 12% (P Ultimate compressive strength did not correlate with osteocyte viability. In the femoral head there is gradual, age-related reduction in osteocyte viability that can be more pronounced in hip fracture. Osteocyte death may affect bone quality by impairing repair of fatigue damage. PMID:8275364

1993-01-01

33

Self-management of fatigue in rheumatoid arthritis: a randomised controlled trial of group cognitive-behavioural therapy  

UK PubMed Central (United Kingdom)

ObjectivesTo investigate the effect of group cognitive behavioural therapy (CBT) for fatigue self-management, compared with groups receiving fatigue information alone, on fatigue...Full Text Available

36

Parental infertility and sexual maturation in children  

UK PubMed Central (United Kingdom)

BACKGROUNDThe reproductive health of children born of infertile couples may be affected by infertility treatment or factors associated with infertility. We examined sexual maturation...Full Text Available

2009-02-01

38

Mapping Deforestation and Land Use in Amazon Rainforest Using ...  

Science.gov (United States)

Jan 22, 2011 ... Abstract: Land use changes and deforestation in tropical rainforests are among the major factors affecting the overall function of the global ...

39

Factors Affecting Attrition Among Marine Corps Women  

Science.gov (United States)

... 2. Help women become accepted by providing job-related training, creating flexible work groups with good climates, and encourage supervisors to ...

1985-12-01

40

Evaluation of adhesive bonded sandwich panels for ...  

Science.gov (United States)

... content of the environment) are significant factors affecting the useful service life of adhesive bonded plastic composite sandwich panels at 650 F ...

1970-10-01

42

Consanguinity and fetal growth in Pakistani Moslems.  

UK PubMed Central (United Kingdom)

There is conflicting evidence about the effect of parental consanguinity on fetal growth. Previous studies have not always allowed for other factors that are known to affect birth weight, in particular,...Full Text Available

1987-03-01

43

The state of public power  

Energy Technology Data Exchange (ETDEWEB)

Opinions on factors affecting public power systems are presented. Social, economic, and political factors are discussed in terms of their impact on public power. Competition with investor-owned utilities is the primary focus of the paper. Privatization and regulations are other issues discussed.

1995-12-31

44

Temporal changes in key maternal and fetal factors affecting birth outcomes: A 32-year population-based study in an industrial city  

UK PubMed Central (United Kingdom)

BackgroundThe link between maternal factors and birth outcomes is well established. Substantial changes in society and medical care over time have influenced women's reproductive...Full Text Available

45

Improvement of the mechanical properties of austenitic stainless steel after plasma nitriding  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we report on a series of experiments designed to study the influence of plasma nitriding on the mechanical properties of austenitic stainless steel. Plasma nitriding experiments were conducted on AISI 304L steel in a temperature range of 375-475 C using pulsed-DC plasma with different N{sub 2}-H{sub 2} gas mixtures and treatment times. Firstly the formation and the microstructure of the modified layer will be highlighted followed by the results of hardness measurement, adhesion testing, wear resistance and fatigue life tests. The modified surface was analyzed directly after plasma nitriding as well as using a depth profiling method. The microhardness after plasma nitriding is increased up to 19 GPa, that is a factor of five higher compared to the untreated material (3.3 GPa). The adhesion is examined by Rockwell indentation and scratch test. No delamination of the treated layer could be observed. The wear rate after plasma ...

2000-11-01

46

Effect of the diameter and depth of pinholes on surface characteristics in the DC pulse plasma nitriding process  

International Nuclear Information System (INIS)

The ion nitriding treatment is a process widely used in steel alloys to improve the material's properties; such as surface hardness, resistance to wear, fatigue life and resistance to corrosion. But geometric changes in the components can produce during the nitriding process different effects on the behavior of the plasma, such as local variations in the electric field, an empty cathode effect, etc. These in turn can affect among other factors the local temperature and therefore the kinetics of the process, generating variations in the compound layer thicknesses and zone of diffusion, and micro-hardness profile. These heterogeneities limit the effectiveness of the plasma nitriding process, where control and duplication of the surface modification are most important. This work aims to study the effect of the geometry of the pieces treated with ionic nitriding, especially the effect of the orifices. An understanding of the ...

2006-12-01

47

Dynamic analysis of Darrieus vertical axis wind turbine rotors  

Science.gov (United States)

The dynamic response characteristics of the VAWT rotor are important factors governing the safety and fatigue life of VAWT systems. The principal problems are the determination of critical rotor speeds (resonances) and the assessment of forced vibration response amplitudes. The solution to these problems is complicated by centrifugal and coriolis effects which can have substantial influence on rotor resonant frequencies and mode shapes. This paper will describe and discuss the primary tools now in use at Sandia National Laboratories for rotor analysis. These tools include a lumped springmass model (VAWTDYN) and also finite-element based approaches. The discussion will center on the accuracy and completeness of current capabilities and plans for future research.

1981-01-01

48

Dynamic analysis of Darrieus vertical axis wind turbine rotors  

Science.gov (United States)

The dynamic response characteristics of the vertical axis wind turbine (VAWT) rotor are important factors governing the safety and fatigue life of VAWT systems. The principal problems are the determination of critical rotor speeds (resonances) and the assessment of forced vibration response amplitudes. The solution to these problems is complicated by centrifugal and Coriolis effects which can have substantial influence on rotor resonant frequencies and mode shapes. The primary tools now in use for rotor analysis are described and discussed. These tools include a lumped spring mass model (VAWTDYN) and also finite-element based approaches. The accuracy and completeness of current capabilities are also discussed.

1981-05-01

49

Thermal fatigue of HIPed W/Cr-bronze divertor small scale mock-ups  

International Nuclear Information System (INIS)

Thermal fatigue is one of the key factors governing the lifetime of the divertor plate. Tungsten is a promising candidate to cover the surface of the divertor plate in the design of the international thermonuclear experimental reactor (ITER). The W/Cr-bronze divertor small scale mock-ups were manufactured by hot isostatic pressing (HIPing) technique. Thermal fatigue tests of W/Cr-bronze divertor mock-ups have been carried out by an electron beam facility. The mock-ups were tested under a cyclic surface heat flux of 9 MW m"-"2 for 1000 cycles. The electron beam was loaded on the mock-up surface for 20 s and unloaded for 20 s, alternately. The flow rate of water coolant was 0.1 L s"-"1. The 0.3 mm diameter NiCr-NiSi thermocouples were used to monitor the temperature distribution of the mock-up. It was found that the maximum temperature of the tungsten surface was about 400 degree sign C. The saturated temperature at the joint ...

2004-11-15

50

Fatigue and creep crack growth behaviour at high temperatures for weld metals of Alloy 800 and Alloy 617  

International Nuclear Information System (INIS)

High temperature fatigue crack growth (FCG) and creep crack growth (CCG) experiments have been conducted in air on weld metal, heat affected zone (HAZ) and base metal of the austenitic Alloy 800 and the nickel base Alloy 617. Tests were performed on specimens machined from pipes, in the temperature range 550-900 deg. C. The crack propagation mode was examined. At all temperatures and for both materials, FCG of base metal was found to be the highest, whereas the weld metal exhibited the lowest FCG rate. The FCG rate in the HAZ was found to lie in between of those observed for base and weld metal. The crack propagation mode remained transgranular in base metal and transdendritic in weld metal at all temperatures. CCG behaviour could be described using the energy rate integral C*. Base metal and weld metal exhibited similar CCG rate at same C*. The crack propagation mode under CCG condition was found to be intergranular in base metal and HAZ and ...

1993-08-15

51

Investigation into the fatigue behaviour of wood laminates for wind energy converter blade design  

Energy Technology Data Exchange (ETDEWEB)

A thesis is presented on improving the understanding of the fatigue properties of wood and fatigue failure mechanisms in the design of wind turbine blades. Three main areas were researched: the effect of R ratio on fatigue life, the effect of moisture on fatigue life and the development of cumulative damage laws. Tests were carried out on mainly four-ply laminates. Recommendations to future work are outlined. (U.K.).

1987-01-01

52

Chronic Fatigue: Can Natural Remedies Boost My Energy?  

Science.gov (United States)

... Question Chronic fatigue: Can natural remedies boost my energy? Are there any natural remedies that reduce chronic ... AN01764 ">Chronic fatigue: Can natural remedies boost my energy? Guidelines for sites linking to MayoClinic.com ...

53

Impacts of grain structure and texture on the high-temperature fatigue in ODS superalloys; Einfluss der Kornstruktur und der Textur auf die Hochtemperaturermuedung von ODS-Superlegierungen  

Energy Technology Data Exchange (ETDEWEB)

The study examines the isothermal fatigue properties of novel ODS iron-base or nickel-base superalloys at temperatures of 850 C and 1050 C. The materials are different in grain structure and texture, so that particularly the effects of grain structures and textures can be studied. In order to also perform examinations of creep-fatigue interactions, various load cycles are applied. It is shown that the LCF-affected life of the grain structures of both alloy types is determined by the elastic modulus. The cyclic lifetimes determined by the conventional Manson-Coffin method for both alloy types exhibit differences of up to two orders of magnitude. Using the product of the total strain range and the elastic modulus, however, will yield precise life predictions. Under conditions of LCF stress only, the grain structure has no effect on the materials` service life, other than in the case of creep-fatigue, but ...

1995-12-31

54

Update on Environmental Risk Factors for Attention-Deficit/Hyperactivity Disorder  

British Library Electronic Table of Contents (United Kingdom)

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurobehavioral disorder affecting 5% to 10% of children. Although considered to be a highly familial disorder, ADHD heritability estimates of 60% to 80% highlight the considerable role that environmental factors may still play in disorder susceptibility. Proposed ADHD environmental risk factors include prenatal substance exposures, heavy metal and chemical exposures, nutritional factors, and lifestyle/psychosocial factors. This paper reviews the literature published in 2010 investigating the association between environmental risk factors and ADHD or related symptomatology. Sources of risk factor exposure and the proposed mechanism by which each exposure is linked to ADHD-related neurobehavioral changes are also reported. Metho...

2011-01-01

55

Analysis of effect factors-based stochastic network planning model  

British Library Electronic Table of Contents (United Kingdom)

Looking at all the indeterminate factors as a whole and regarding activity durations as independent random variables, the traditional stochastic network planning models ignore the inevitable relationship and dependence among activity durations when more than one activity is possibly affected by the same indeterminate factors. On this basis of analysis of indeterminate effect factors of durations, the effect factors-based stochastic network planning (EFBSNP) model is proposed, which emphasizes on the effects of not only logistic and organizational relationships, but also the dependent relationships, due to indeterminate factors among activity durations on the project period. By virtue of indeterminate factor analysis the model extracts and describes the quantitatively indeterminate effect f...

2008-01-01

56

Fatigue life prediction of cross-ply composite laminates  

Energy Technology Data Exchange (ETDEWEB)

To predict the fatigue life of fiber reinforced composites, fatigue process of CFRP laminates of [0 /90 ]{sub s} is investigated and the influence of damages occurring at fiber, matrix and fiber/matrix interface on the various critical strengths and the relationship between residual critical strength and failure are discussed. As a result, it was shown that fatigue strength (i.e. fatigue life) consisted of residual critical strength and stresses occurring at each layer (0 and 90 layers) and interlayer. Moreover, the fatigue failure occurred because the residual critical strength of each layer and interlayer decreased with dependence of their microdamage densities, so that the fatigue life can be predicted by evaluating microdamage behavior in fatigue process. (orig.) 14 refs.

1997-11-15

57

Fatigue Is a Predictor for Cardiovascular Outcomes in Patients Undergoing Hemodialysis  

UK PubMed Central (United Kingdom)

Background and objectives: Despite potential significance of fatigue and its underlying components in the occurrence of cardiovascular diseases, epidemiologic data showing the link are virtually limited....Full Text Available

2010-04-01

58

FATIGUE OF BIOMATERIALS: HARD TISSUES  

UK PubMed Central (United Kingdom)

The fatigue and fracture behavior of hard tissues are topics of considerable interest today. This special group of organic materials comprises the highly mineralized and load-bearing tissues...Full Text Available

2010-09-01

59

Effects of nitrogen fertilization on forest trees in relation to insect resistance and to red-listed insect species  

Energy Technology Data Exchange (ETDEWEB)

Ecosystems worldwide are experiencing unprecedented nitrogen enrichment through fertilization and pollution. While longterm ecological consequences are difficult to predict, it seems that plants and animals adapted to nitrogen-limited environments are at particular risk from these changes. This report summarizes the limited body of literature which addresses this important topic. From a herbivoreAes perspective, fertilization increases the nutritional quality of host plant tissues. In some cases fertilization has lead to decreased production of defensive compounds. How this affects populations of insects is unclear because fertilization affects not only herbivores but their natural enemies. This report outlines how fertilization affects tree processes such as growth, photosynthesis, and production of defensive compounds. The many factors that affect insect repsonse to fertilization ...

2001-10-01

60

Plasma surface engineering of low alloy steel  

Energy Technology Data Exchange (ETDEWEB)

The surface of low alloy steel (En40B) has been engineered in the plasma of a glow discharge via plasma nitriding and ion plating of titanium nitride (TiN) coatings on the nitrided substrates with the purpose of enhancing the surface properties and fatigue strength. The nitriding response of the steel has been accessed by the evaluation of phase composition, layer thickness, hardness profile, residual stresses and nitrogen and carbon distributions. The wear and fatigue characteristics of the plasma-nitrided steel have been investigated and simple models have been developed to describe the influence of such properties as depth and strength of the nitrided case on the fatigue limit and load-bearing capacity of the nitrided steel. In order to further improve the tribological properties and load-bearing capacity of the low alloy steel, a duplex plasma surface-engineering technique has been developed. This is achieved by plasma ...

1991-07-07

61

Fatigue tests on a ferritic-martensitic steel at 420 C: Comparison between in-situ and postirradiation properties  

Energy Technology Data Exchange (ETDEWEB)

Strain-controlled fatigue experiments under simultaneous irradiation have been performed to investigate the specific loadings of structural materials in next-step fusion devices. All irradiations were done on specimens made of the tempered ferritic/martensitic Cr steel MANET-I at 420 C using a 104 MeV [alpha]-particle beam. Continuous push-pull cycling (R=-1) has been applied with total strain ranges [Delta][epsilon][sub t] between 0.5 and 1.0%. Under in-beam conditions at e.g. [Delta][epsilon][sub t]= 0.5% a number of cycles to failure of N[sub f]=42000, a He concentration of 400 appm and a damage dose of 1.6 dpa has been reached. This N[sub f] is by about a factor of two below the average N[sub f]-value of unirradiated reference tests, but seven times higher than N[sub f] of comparable postirradiated specimens. It was found, that at least at 420 C conventional postirradiation tests are a conservative approach to in-situ conditions, and that ...

1994-09-01

62

Effects of matrix resin and fiber content on behavior of fatigue crack propagation in continuous-fiber-mat reinforced CP-resin composites; Renzoku sen`i mat kyoka CP resin fukugozai no hiro kiretsu denpa tokusei ni oyobosu bozai oyobi sen`i gan`yuritsu no eikyo  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the present work is to investigate the effects of matrix resin and fiber content on the behavior of fatigue crack propagation in continuous-glass-fiber-mat reinforced CP-resin composites. For this purpose, ductile matrix resin and brittle one are used. These two kinds of resins have the characteristic that the elastic modulus and tensile strength are nearly the same with each other while the elongation is different. The composite specimens are made of these resins and continuous grass fiber mat of 20 wt.% and 60 wt% fiber contents. The fatigue crack propagation test was conducted by using the tapered DCB specimens to control the stress intensity factor range, {delta}K, during the test. The results obtained are as follows; (1) The relation between the crack propagation rate, da/dN, and {delta}K for all the present materials is shown by a straight line in logarithmic representation. (2) For the composites of 20 ...

1996-05-15

63

Visual Genome-Wide RNAi Screening to Identify Human Host Factors Required for Trypanosoma cruzi Infection  

UK PubMed Central (United Kingdom)

The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy...Full Text Available

64

Untreated Poor Vision: A Contributing Factor to Late-Life Dementia  

UK PubMed Central (United Kingdom)

Ophthalmologic abnormalities have been described in patients with dementia, but the extent to which poor vision and treatment for visual disorders affect cognitive decline is not well defined. Linked...Full Text Available

2010-03-15

65

The future of dentistry: new challenges, new directions.  

UK PubMed Central (United Kingdom)

The challenge to our profession today is to improve the quality of oral health while overcoming both extrinsic and intrinsic factors which may adversely affect our progress toward this goal. The combined...Full Text Available

1990-05-01

66

Safety culture development at Daya Bay NPP  

International Nuclear Information System (INIS)

From view on Organization Behavior theory, the concept, development and affecting factors of safety culture are introduced. The focuses are on the establishment, development and management practice for safety culture at Daya Bay NPP. A strong safety culture, also demonstrated, has contributed greatly to improving performance at Daya Bay

2001-12-01

67

Milk fever and alert downer cows: Does hypophosphatemia affect the treatment response?  

UK PubMed Central (United Kingdom)

The purpose of this prospective cohort study was to identify factors that place a dairy cow with uncomplicated milk fever (MF) at significant risk of becoming an alert downer cow (ADC) and to verify...Full Text Available

2007-05-01

68

Membrane filtration of food suspensions.  

UK PubMed Central (United Kingdom)

Factors affecting the membrane filtration of food suspensions were studied for 58 foods and 13 membrane filters. Lot number within a brand, pore size (0.45 or 0.8 micrometer), and time elapsed before...Full Text Available

1979-01-01

69

Factors Affecting Daughter Cells' Arrangement during the Early Bacterial Divisions  

UK PubMed Central (United Kingdom)

On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed...Full Text Available

70

EFFECTS OF ALTERNATIVE NEW SOURCE PERFORMANCE STANDARDS ON FLUE GAS DESULFURIZATION SYSTEM SUPPLY AND DEMAND  

Science.gov (United States)

The report discusses the capabilities of equipment vendors to supply and install the quantity of flue gas desulfurization systems required to meet alternative standards for coal-fired steam generators. It analyzes limiting factors affecting supply capabilities (such as the availa...

71

Determinants of output in group and solo medical practice.  

UK PubMed Central (United Kingdom)

Certain structural and environmental factors other than technical combination of resources and firm size are hypothesized to affect medical practice output. Four groups of variables related to physician...Full Text Available

1976-01-01

72

Analysis of Failed Spinal Cord Stimulation Trials in the Treatment of Intractable Chronic Pain  

UK PubMed Central (United Kingdom)

ObjectiveThe purpose of this study is to identify the factors affecting the failure of trials (<50% pain reduction in pain for trial period) to improve success rate of spinal...Full Text Available

2008-02-01

73

Affective and Personality Risk and Cognitive Mediators of Initial Adolescent Alcohol Use*  

UK PubMed Central (United Kingdom)

Objective:This study examined the role of cognitive factors—such as expectancies regarding the consequences of not drinking and perceptions of peer drinking—in...Full Text Available

2010-07-01

74

Factors affecting costs and utilization of type 2 diabetes healthcare: a cross-sectional survey among 15 hospitals in urban China  

UK PubMed Central (United Kingdom)

BackgroundType 2 Diabetes mellitus (T2DM) affects persons of all ages, while also placing heavy economic burdens on national economies and healthcare systems. The study aims to investigate...Full Text Available

75

Methods for probabilistic design of wind turbines  

Energy Technology Data Exchange (ETDEWEB)

This report gives a brief introduction to the project `Probabilistic Design Tool for Wind Turbines` - PRODETO - which was carried out during the years 1996-98 with partial funding from the European Commission under the Non-Nuclear Energy Programme JOULE III. The report gives an overview of the objectives and motivation for the project, and the methodology used. In this context, an example of reliability-based wind turbine design against fatigue failure is outlined with emphasis on the various important steps herein, which include probabilistic load and resistance modelling, calculation of failure probability, and calibration of partial safety factors for use with a deterministic design code format. The results of the project are presented with emphasis on a developed computer program and its capabilities, and the various elements of an executed case study are outlined. A list of project reports concludes the report. (au)

1998-12-01

78

Relationship between microstructural evolution and low cycle fatigue behaviour at 550/sup 0/C of alloy 800 grade 2  

Energy Technology Data Exchange (ETDEWEB)

In this study, deformation modes and precipitations have been characterized in test pieces made of alloy 800, grade 2 hyper-hardened state and age-conditioned for 3000 h at 550/sup 0/C, used for steam generator tubes of the Super Phenix Reactor, after continuous fatigue and fatigue-relaxation tests in the oligocyclic range. This microstructural study has provided an interpretation of the fatigue behaviour of the material.

1989-01-01

82

Improvement of the fatigue strength of AISI 4140 steel by an ion nitriding process  

Energy Technology Data Exchange (ETDEWEB)

The influence of plasma nitriding on the fatigue behaviour of AISI 4140 low-alloy steel was investigated under varying process conditions of temperature (500-600 C), time (1-12 h), heat treatment before ion nitriding (quenched and tempered, normalized) and gas mixture (50% H{sub 2}-50% N{sub 2}). A rotating bending fatigue machine was used to determine the fatigue strength. It was found that the plasma nitriding improves the fatigue strength and increases the fatigue limit depending on the surface hardness of the case depth. The microstructure of surface and diffusion layers was examined by optical microscopy. The fracture surface of specimens and the origin of fatigue cracks were observed by scanning electron microscopy.

1995-06-01

83

High temperature fatigue example of creep life time prediction for grade 2 alloy 800 at 550 C  

Energy Technology Data Exchange (ETDEWEB)

Experimental data on the material characteristics of structures subjected to thermal and mechanical cycling are needed for designing structural parts for creep and creep-fatigue interaction. Moreover, high-temperature low-cycle fatigue data are not sufficient to predict the fatigue creep lifetime. In order to check the reliability of steam generators, tests on pipe materials are conducted under cyclic thermal loading. The tests have been performed on an iron-nickel chromium alloy (alloy 800). Isothermal low-cycle fatigue tests have been conducted at 550 C. 15 refs.

1994-04-01

84

Work-related complaints of arm, neck and shoulder among computer office workers in an Asian country: prevalence and validation of a risk-factor questionnaire  

UK PubMed Central (United Kingdom)

BackgroundComplaints of arm, neck and/or shoulders (CANS) affects millions of computer office workers. However its prevalence and associated risk factors in developing countries...Full Text Available

85

The Sigma Factor AlgU (AlgT) Controls Exopolysaccharide Production and Tolerance towards Desiccation and Osmotic Stress in the Biocontrol Agent Pseudomonas fluorescens CHA0  

UK PubMed Central (United Kingdom)

A variety of stress situations may affect the activity and survival of plant-beneficial pseudomonads added to soil to control root diseases. This study focused on the roles of the sigma factor AlgU...Full Text Available

2001-12-01

86

Fatigue behavior of Alloy 690 and Alloy 800 SG tubing at temperatures up to 330{sup o}C in very high cycle fatigue regime  

Energy Technology Data Exchange (ETDEWEB)

During the service in nuclear power plants, steam generator (SG) tubing will suffer from a vibration with a frequency from 30-40 Hz. This means that SG tubing will undergo a very high cycle fatigue process during the design life time (25 years=about 3x10{sup 10}cycles). The material degradation and the very high cycle fatigue life of SG tubing materials due to the vibration are therefore of concern. In this investigation, the fatigue properties of Alloy 690 and Alloy 800 SG tubing in the very high cycle fatigue regime (higher than 10{sup 7} cycles) and strain controlled fatigue at temperatures up to 330{sup o}C have been investigated. The fatigue properties of SG tubing of Alloy 690 are comparable to that of wrought material. The strain controlled fatigue properties of Alloy 690 and Alloy 800 are slightly better at 288{sup o}C than at room ...

2007-07-01

87

Fatigue behavior of Alloy 690 and Alloy 800 SG tubing at temperatures up to 330"oC in very high cycle fatigue regime  

International Nuclear Information System (INIS)

During the service in nuclear power plants, steam generator (SG) tubing will suffer from a vibration with a frequency from 30-40 Hz. This means that SG tubing will undergo a very high cycle fatigue process during the design life time (25 years=about 3x10"1"0cycles). The material degradation and the very high cycle fatigue life of SG tubing materials due to the vibration are therefore of concern. In this investigation, the fatigue properties of Alloy 690 and Alloy 800 SG tubing in the very high cycle fatigue regime (higher than 10"7 cycles) and strain controlled fatigue at temperatures up to 330"oC have been investigated. The fatigue properties of SG tubing of Alloy 690 are comparable to that of wrought material. The strain controlled fatigue properties of Alloy 690 and Alloy 800 are slightly better at 288"oC than at room temperature (RT). At ...

2007-08-19

88

Factors that can influence the economic feasibility of stand-alone and grid-connected photovoltaic systems: case studies using the software AVES-F  

International Nuclear Information System (INIS)

This paper presents case studies of economic feasibility of solar photovoltaic systems using the software AVES-F (Analysis of Economic Feasibility of Photovoltaic Systems), developed by the authors, considering cases of stand-alone and grid-connected systems. The software takes into account several factors that can influence the economic feasibility of these kind of systems, like load to be supplied, distance to the grid, the use regime of the system, applied subsidies and others. The main goal of this paper is to analyze some of these factors and to observe how they can affect the economics of PV systems for electricity generation. (authors)

2004-06-07

89

Area Factor Determinations for an Industrial Worker Exposed to a Concrete Slab End-State  

International Nuclear Information System (INIS)

The U.S. Department of Energy's (DOE) Savannah River Site (SRS) is decommissioning many of its excess facilities through removal of the facility structures leaving only the concrete-slab foundations in place. Site-specific, risk-based derived concentration guideline levels (DCGLs) for radionuclides have been determined for a future industrial worker potentially exposed to residual contamination on these concrete slabs as described in Jannik. These risk-based DCGLs were estimated for an exposure area of 100 m2. During deactivation and decommissioning (D and D) operations at SRS, the need for area factors for larger and smaller contaminated areas arose. This paper compares the area factors determined for an industrial worker exposed to a concrete slab end-state for several radionuclides of concern at SRS with 1) the illustrative area factors provided in MARSSIM, 2) the area correction factors provided in ...

2008-01-01

90

Influence of sea water on the fatigue strength and notch sensitivity of a plasma nitrided B-Mn steel  

Energy Technology Data Exchange (ETDEWEB)

Notched and smooth cylindrical plasma nitrided (PN) and quench and tempered (Q and T) steel specimens made of a B-Mn SS2131 ({approx}AISI 15B21H) steel have been exposed to constant amplitude plane reversed bending corrosion fatigue tests (R = -1) at 47 Hz in sea water. S - N curves show that sea water suppresses the fatigue limit and reduces fatigue strength (especially at long lives) of smooth and notched Q and T and PN specimens. Plasma nitriding improves the corrosion fatigue resistance of Q and T specimens; this is associated with the good corrosion resistance of {epsilon} and {gamma}`-phases, the enhancement of corrosion and fatigue by compressive residual stresses, and the consumption of H{sup +} ions during reduction of nitrogen. This improvement is more significant for smooth specimens and for long lives. Notch sensitivity of Q and T and PN specimens decreases with ...

1998-06-01

91

Development, dimensions, reliability and validity of the novel Manchester COPD fatigue scale  

DEFF Research Database (Denmark)

INTRODUCTION: Fatigue is a prominent symptom in chronic obstructive pulmonary disease (COPD) and it has distinctive features; however, there is a need for a robust scale to measure fatigue in COPD. METHODS: At baseline, 122 patients with COPD (forced expiratory volume in 1 s (FEV(1)) 52%, women 38%, mean age 66 years) completed a pilot fatigue scale covering a pool of 57 items and underwent a range of tests, including indicators of mood and a short general fatigue questionnaire. All patients responded to the 57-item scale and it was readministered to a subset of 30 patients. The pilot scale was first subjected to constructive validated shortening steps and then to a principal components analysis. RESULTS: The Manchester COPD fatigue scale (MCFS) consists of 27 items, loading into three dimensions: physical, cognitive and psychosocial fatigue. Internal ...

2009-01-01

92

Methods for preventing steam generator failure or degradation  

Energy Technology Data Exchange (ETDEWEB)

PWR steam generators have suffered from a variety of degradation phenomena. This paper identifies the corrosion-related defects and their probable causes and suggests approaches to correct and prevent corrosive activity. In the attempt to solve the degradation problems, research programs have concentrated on modifying materials, stresses, and the chemical environment in both new and operating steam generators. The following corrosion-related defects have been studied: tube wastage, denting, primary side (ID) intergranular stress corrosion cracking (IGSCC), OD-initiated intergranular attack (IGA), pitting, and corrosion fatigue. Plants affected by wastage have greatly reduced their problem by adopting an all volatile treatment (AVT). In the case of denting, a less aggressive chemical environment is recommended. Primary side IGSCC responds to temperature reduction, stress relief, and material improvements, while flushing and boric acid addition ...

1986-01-01

93

Methods for preventing steam generator failure or degradation  

International Nuclear Information System (INIS)

PWR steam generators have suffered from a variety of degradation phenomena. This paper identifies the corrosion-related defects and their probable causes and suggests approaches to correct and prevent corrosive activity. In the attempt to solve the degradation problems, research programs have concentrated on modifying materials, stresses, and the chemical environment in both new and operating steam generators. The following corrosion-related defects have been studied: tube wastage, denting, primary side (ID) intergranular stress corrosion cracking (IGSCC), OD-initiated intergranular attack (IGA), pitting, and corrosion fatigue. Plants affected by wastage have greatly reduced their problem by adopting an all volatile treatment (AVT). In the case of denting, a less aggressive chemical environment is recommended. Primary side IGSCC responds to temperature reduction, stress relief, and material improvements, while flushing and boric acid addition ...

94

Dislocation plasticity and complementary deformation mechanisms in polycrystalline Mg alloys  

Energy Technology Data Exchange (ETDEWEB)

Deformation mechanisms of Mg-Al-Zn (AZ31) alloys were investigated by performing tensile test at room temperature. In fine grain Mg alloys deformed at room temperature, nonbasal slip systems were found to be active as well as basal slip systems because of grain-boundary compatibility effect. Slip-induced grain-boundary sliding occurred as a complementary deformation mechanism to give rise to c-axis component of strain. With increasing grain size, the activation of the nonbasal slip systems was limited near grain boundaries. Instead of grain-boundary sliding, twinning occurred as a complementary deformation mechanism in large grained samples. Orientation analysis of twins indicated that twinning is induced by stress concentration due to the pile up of basal dislocations. The grain-size dependence on deformation mechanism was found to affect yielding behavior both microscopically and macroscopically which can influence various mechanical properties such as ...

2004-07-01

95

Reliability and validity of the PedsQL? Multidimensional Fatigue Scale in Japan  

British Library Electronic Table of Contents (United Kingdom)

Purpose To examine the reliability and validity of the Japanese-language version of the PedsQL? Multidimensional Fatigue Scale and to investigate the agreement between child self-reported fatigue and parent proxy-reported fatigue. Methods The Japanese-language version of the PedsQL? Multidimensional Fatigue Scale was administered to 652 preschoolers and schoolchildren aged 5?12 and their parents, and to 91 parents of preschool children aged 1?4. Results Internal consistency reliability was 0.62?0.87 for children and 0.81?0.93 for parents. Known-group validity was examined between a group of healthy samples (n?=?530) and chronic condition sample (n?=?102); the chronically ill group reported a significantly higher perceived fatigue problem. Correlations between child self- and parent proxy r...

2011-01-01

96

Organization and management activities in the nuclear power industry  

International Nuclear Information System (INIS)

The purpose of organization and management development activities in the commercial nuclear power industry is to foster high levels of power plant performance and safety through improved human performance. The NRC has been working to develop assessment tools to assay the effects of organizational factors on plant safety. The utility industry has been working on initiatives targeting individual accountability, the improvement of plant performance and the elimination of the items identified through the NRC assessment process. Organization and management activities do not focus on industry organizational charts, but on the personnel processes and dimensions (factors) that affect safety and economic performance. As individual terms these activities are often combined and referred to as organizational factors. As an area of study, organizational factors has become more prominent as the ...

1994-04-01

97

Visual impact evaluation of a wind park in a Greek island  

Energy Technology Data Exchange (ETDEWEB)

The visual impact of wind turbines is one of the main factors affecting public acceptance of wind parks. This paper evaluates the visual impact of a wind park in Chania, Crete, using the Spanish method of evaluation. The outcomes are combined with the psychometric testing of the residents by the use of questionnaires and with the values of the Spanish method about various scenarios concerning the size of the wind park (double, half, one wind turbine). The results of the study prove that the quantification of the potential visual impact could minimize this, apparently, main reason that affects public acceptance. (author)

2009-04-15

98

Landslides affecting sedimentary characteristics of reservoir basin  

British Library Electronic Table of Contents (United Kingdom)

Typhoons Aere (2004) and Matsa (2005) caused high nephelometric turbidity in the Shihmen reservoir in northern Taiwan, jeopardizing the operation of the reservoir for several days, and ultimately impacting the living conditions and economy of the downstream residents. The torrential rains caused landslides and debris flows in upland areas, and flowed into riverbeds, likely contributing significantly to the suspended sediment yields in the reservoir. This investigation elucidates how upland landslides affect sediment attributes in the reservoir basin. Study methods including field observations, spatial analysis in GIS and aerial photo interpretation are adopted to trace the sediment sources and contributing factors to the landslide. Torrential rains induced landslides and debris-flows uplan...

2010-01-01

99

Effect of polyacrylamide on the erodibility factor of a loam soil  

British Library Electronic Table of Contents (United Kingdom)

Despite the proven utility of the Universal Soil Loss Equation (USLE) to predict soil rainfall erosion, it has limited precision in predicting soil loss in some soil series. Also, runoff is a factor in rainfall erosion and some models, such as the modified USLE (USLE-M), include runoff in predicting soil erosion. The soil erodibility factor is an essential component in both models and this may be affected by application of soil conditioners, such as polyacrylamide (PAM). The objectives of this study were to determine the effects of different rates of PAM (0, 1, 2, 4, and 6kgha-1) applied with sprinkler irrigation water, followed by two sprinkler irrigations with no PAM, on the erodibility of a loam soil under a rainfall simulator in a laboratory. The range of erodibility factor Ku obtained...

2008-01-01

100

Psychological factors affecting public acceptance of nuclear energy. Comparative analysis focusing on regional characteristics and degree of knowledge  

International Nuclear Information System (INIS)

The purpose of this research is to clarify how psychological factors' impact on public acceptance of nuclear energy varies with where they live and their degree of knowledge. For this purpose, we carried out questionnaire survey about nuclear energy at three urban areas and two nuclear power plant siting areas. After collecting data, we applied factor analysis to the data, and found four factors which construct cognitive structure of nuclear energy. Using multiple regression analysis, we evaluated the impact of the four factors on two issues: the decision for or against nuclear policy and the reaction to nuclear power plant siting, and compared changes of the impact by where respondents live and their degree of knowledge. Consequently, we found that the impact of all four factors on the two issues varies with where respondents live. We also found that the impact of respondents' ...

2003-12-01

101

Exploring research of factors affecting public acceptance of nuclear energy. Result of a survey at Suginami ward, Tokyo  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this research is to clarify how psychological factor's impact on public acceptance of nuclear energy varies with people's degree of knowledge. For this purpose, we carried out questionnaire survey about nuclear energy at Suginami ward, Tokyo. After collecting data, we applied factor analysis to the data, and found 4 factors: Trust in the Authorities, Superiority of Nuclear Power Generation, Benefit for Nuclear Power Plants' Siting Areas, and Risk Perception about Nuclear Technology. In addition, using multiple regression analysis, we evaluated the impact of the 4 factors on 2 issues: the decision for or against nuclear policy and the reaction to nuclear power plant siting. Consequently, we found the change of impact of all 4 factors on the 2 issues. Especially, the impact of the 4 factors to the reaction to nuclear power ...

2003-03-01

102

Exploring research of factors affecting public acceptance of nuclear energy. Result of a survey at Suginami ward, Tokyo  

International Nuclear Information System (INIS)

The purpose of this research is to clarify how psychological factor's impact on public acceptance of nuclear energy varies with people's degree of knowledge. For this purpose, we carried out questionnaire survey about nuclear energy at Suginami ward, Tokyo. After collecting data, we applied factor analysis to the data, and found 4 factors: Trust in the Authorities, Superiority of Nuclear Power Generation, Benefit for Nuclear Power Plants' Siting Areas, and Risk Perception about Nuclear Technology. In addition, using multiple regression analysis, we evaluated the impact of the 4 factors on 2 issues: the decision for or against nuclear policy and the reaction to nuclear power plant siting. Consequently, we found the change of impact of all 4 factors on the 2 issues. Especially, the impact of the 4 factors to the reaction to nuclear power plant siting was ...

2003-03-01

103

The management of children with chronic fatigue syndrome-like illness in primary care: a cross-sectional study  

UK PubMed Central (United Kingdom)

BackgroundMost studies on children with chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) have been undertaken in tertiary care and little is known about their management...Full Text Available

2006-01-01

104

The Effect of O2, H2O, and N2 on the Fatigue Crack Growth Behavior of an Alpha + Beta Titanium Alloy at 24 C and 177 C  

Science.gov (United States)

To study the effects of atmospheric species on the fatigue crack growth behavior of an a+B titanium

2001-01-01

105

Stress Ratio Effects on Small Fatigue Crack Growth in Ti-6Al ...  

Science.gov (United States)

... in Ti-6Al-4V has been studied quite thoroughly [5-7], much of the work resulting from the Air Force-sponsored High Cycle Fatigue initiative [8]. In ...

2008-11-01

106

Sleep and Fatigue Symptoms in Children and Adolescents With CKD: A Cross-sectional Analysis From the Chronic Kidney Disease in Children (CKiD) Study  

UK PubMed Central (United Kingdom)

BackgroundAlthough symptoms of sleepiness and fatigue are common among adults with Chronic Kidney Disease (CKD), little is known about the prevalence of these symptoms...Full Text Available

2010-02-01

107

Fatigue and Functional Impairment in Early-Stage Non-Small Cell Lung Cancer Survivors  

UK PubMed Central (United Kingdom)

ContextFatigue is the most common sequela among non-small cell lung cancer (NSCLC) survivors 1–6 years post-treatment and is associated with functional limitations.Full Text Available

2011-02-01

108

Effect of physiological levels of caffeine on Ca2+ handling and fatigue development in Xenopus isolated single myofibers  

UK PubMed Central (United Kingdom)

The purpose of the present study was to determine whether exposure to exogenous physiological concentrations of caffeine influence contractility, Ca2+ handling, and fatigue development...Full Text Available

2009-05-01

109

Detecting Retroviral Sequences in Chronic Fatigue Syndrome  

UK PubMed Central (United Kingdom)

XMRV or xenotropic murine leukemia virus-related retrovirus, a recently discovered retrovirus, has been linked to both prostate cancer and chronic fatigue syndrome (CFS). Recently, the teams of Drs....Full Text Available

110

Correlates and Outcomes of Fatigue among Incident Dialysis Patients  

UK PubMed Central (United Kingdom)

Background & objectives: Fatigue is a debilitating symptom experienced by patients undergoing dialysis, but there is only limited information on its prevalence and its association with patient...Full Text Available

2009-11-01

111

Boiler and HRSG tube failures. Lesson 2. Corrosion fatigue  

Energy Technology Data Exchange (ETDEWEB)

Fatigue damage occurs in general when a boiler tube is subject to repeat cyclic or fluctuating loading although the stress produced is below the material yield strength. The types of fatigue damage include, e.g., corrosion, thermal, mechanical, vibration, and creep fatigue. It is important to determine which form of fatigue is active, because measures to avoid repeat failures differ as the case arises. In this lesson, the focus is exclusively on corrosion fatigue. Corrosion fatigue occurs by the combined synergistic actions of cyclic loading and a corrosive environment. It is a discontinuous process with crack initiation and growth during transient periods. The excessive stresses may be caused during boiler operation by the restraint at tube attachments and by load changes (in particular during cold starts or forced cools) or during shutdown or restart of ...

2009-10-15

112

Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions: reliability of a repeated sprint test  

UK PubMed Central (United Kingdom)

BackgroundPhysical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However...Full Text Available

113

Modeling of a self-excited pulse combustor and stability analysis  

British Library Electronic Table of Contents (United Kingdom)

The major bottleneck for popularization and utilization of the conventional mechanical valve pulse combustors is the self-priming mode of gas supply. An aerodynamic valve (as against mechanical valve) self-excited pulse combustor of the Helmholtz-type with continuous supply of gas and air was designed and a mathematical model was established in this paper. The theoretical model employed well-stirred reactor model and a single step Arrhenius chemistry, and took those factors which might affect the combustion stability into account. The factors include the variation of the mass rate of the reactants affected by the pressure in the combustion chamber, the convective and radiation heat loss in the combustion chamber, and the heat transfer and wall friction in the tailpipe. The effect of wall t...

2011-01-01

114

An empirical analysis of factors affecting adolescent attachment in adoptive families with homosexual and straight parents  

British Library Electronic Table of Contents (United Kingdom)

Data were collected on 154 adoptive families with gay/lesbian and straight adoptive parents (154 parent respondents and 210 adolescent respondents). This study was principally interested in factors affecting adolescent attachment including parent sexual orientation, adolescent and parent life satisfaction, and parent level of relationship satisfaction with their adopted child as well as other key parent, child and adoption characteristics. The results suggest that higher level of adopted adolescent attachment to parents is not related to adoptive parent sexual orientation. Adolescent attachment to parents is related to adolescent life satisfaction; parent level of relationship satisfaction with their adopted child, number of placements prior to adoption, and adolescent's current age. Adole...

2009-01-01

115

The Effect of Compressive Loading on the Fatigue Lifetime of ...  

Science.gov (United States)

... Coupon 119 * 52 Probability of Survival Versus Ultimate Compressive Strength for Un-notched Laminate 1 Coupon ipn ...

1979-10-01

116

Hollow Glass Filament Reinforced Plastics for Deep ...  

Science.gov (United States)

... Problems investigated in various basic hollowness ratios include ultimate compressive strength, fatigue properties, buckling characteristics, and ...

1966-02-08

117

Developing effective professional bus driver health programs: An investigation of self-rated health.  

Science.gov (United States)

The health of professional bus drivers is a critical factor in their driving performance; any impairment may lead to undesired consequences. In an attempt to develop and prioritize health and wellness programs, this study investigates the factors significantly affecting the health conditions of professional bus drivers, as well as the strength of these factors. This study uses self-rated health as the examination measurement. This simple assessment is an inclusive measure of health status for judging health trajectory, and is highly associated with changes in functional ability, including perceived control over driving. This study evaluates driver responses of self-rated health with ordered response models that consider factors such as the driver reported health problems, physical and psychological conditions, demographic factors, driving experience, and working ...

2011-06-24

118

Xenotropic murine leukaemia virus-related virus (XMRV) does not cause chronic fatigue.  

Science.gov (United States)

The xenotropic murine leukaemia virus-related virus (XMRV), a gammaretrovirus, was discovered in prostate cancer tumours by Virochip technology in 2006. It was subsequently detected in chronic fatigue patients in 2009. The association between XMRV and chronic fatigue has proved to be controversial. No study has confirmed these findings and many have refuted them. Here, we present the evidence for our contention that XMRV is not a human pathogen. PMID:21978843

2011-10-01

119

Thermal fatigue failure at the White Cliffs solar thermal power plant  

Energy Technology Data Exchange (ETDEWEB)

The failure of receivers has been one of the main operating problems at the White Cliffs solar thermal power plant. This Technical Note reports the results of an initial investigation that identifies the cause as having been their thermal fatiguing of the tube walls. The fatigue appears to be caused by unstable heat transfer at vapor qualities below the point where critical heat flux is generally exceeded. Methods for avoiding this problem are tested.

1995-02-01

120

Two-photon exchange at low Q{sup 2}  

Science.gov (United States)

We studied two-photon exchange for elastic electron-proton scattering at low Q{sup 2}. Compact approximate formulas for the amplitudes were obtained. Numerical calculations were done for Q{sup 2}{<=}0.1 GeV{sup 2} with several realistic form factor parametrizations, yielding similar results. They indicate that the corrections to the magnetic form factor can visibly affect the cross-section and proton radii. For low-Q{sup 2} electron-neutron scattering two-photon exchange corrections were shown to be negligibly small00.

2007-03-15

121

Some structural factors affecting the critical temperatures of superconductors  

Energy Technology Data Exchange (ETDEWEB)

A new empirical expression is presented for the T/sub c/ of A-15 compounds, T/sub c/ = 210 2R/sub A/-d/sub 0//R/sub B/..sqrt..M/sub A/ x R/sup 3//sub A/g-barZ-bary/sub B//RB/R/sup 3//sub B/n-baray/sub A//R/sub A/, from which the effects of some structural factors on T/sub c/ for high-T/sub c/ superconductors are obvious.

1981-07-01

122

Thermal-hydraulic limitations on water-cooled limiters  

Energy Technology Data Exchange (ETDEWEB)

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on current design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated conditions. Since the data ...

1984-08-01

123

Thermal-hydraulic limitations on water-cooled fusion reactor components  

Energy Technology Data Exchange (ETDEWEB)

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on conventional design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require unconventional shapes or heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated ...

1986-01-01

124

Thermal-hydraulic limitations on water-cooled fusion reactor components  

Energy Technology Data Exchange (ETDEWEB)

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on conventional design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require unconventional shapes or heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated ...

1987-01-01

125

Thermal-hydraulic limitations on water-cooled fusion reactor components  

International Nuclear Information System (INIS)

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on conventional design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require unconventional shapes or heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated ...

1986-12-07

126

Modified 9Cr-1Mo steel shows excellent potential for steam generator applications  

Energy Technology Data Exchange (ETDEWEB)

A 9Cr-1Mo steel with properties improved over other ferritics in the ranges from 9 to 12% Cr and 1 to 2% Mo and over the widely used 2 1/2 Cr-1Mo steel has recently been developed. The main changes in the modified alloy, compared with the standard alloy, include: addition of niobium and vanadium, to improve the alloy's elevated-temperature strength properties; a specified range for each element; and a specification for nitrogen, which is not listed for the standard 9Cr-1Mo. Microstructural work has indicated that the improved strength of the modified alloy comes from two factors: (1) fine M/sub 23/C/sub 6/ precipitate particles nucleate on Nb/C, N, which comes out first during the heat treatment; and (2) the vanadium enters M/sub 23/C/sub 6/ and retards its growth at the service temperature. Mechanical properties discussed were Charpy-impact, tensile, and creep properties. Other properties included were: thermal expansion coefficient, ...

1982-12-01

127

Factors affecting public and political acceptance for the implementation of geological disposal  

International Nuclear Information System (INIS)

The main objective of this paper is to identify conditions which affect public concern (either increase or decrease) and political acceptance for developing and implementing programmes for geologic disposal of long-lived radioactive waste. It also looks how citizens and relevant actors can be associated in the decision making process in such a way that their input is enriching the outcome towards a more socially robust and sustainable solution. Finally, it aims at learning from the interaction how to optimise risk management addressing needs and expectations of the public and of other relevant stakeholders. In order to meet these objectives, factors of relevance for societal acceptance conditions are identified, described and analysed. Subsequently these factors are looked for in the real world of nuclear waste management through cases in several countries. The analysis is conducted for six stages of a repository programme ...

2007-09-02

128

The effect of trace elements on the fatigue behaviour of a carbide-hardened Fe-Ni-Cr alloy. Der Effekt von Spurenelementen auf das Zeitstandverhalten einer karbidverfestigten Fe-Ni-Cr-Legierung  

Energy Technology Data Exchange (ETDEWEB)

Fatigue tests were accomplished with a series of specimens doped with trace elements of a hardened Fe-Ni-Cr alloy, cast and hardened with intermetallic phases for determining the influence of these elements on the high temperature strength properties. The results of extensive fatigue tests show that even small contents of Te, Bi, Se, Pb, Tl and Zn considerably influence the life and creep processes especially after longer running periods, when added individually or combinedly. In contrast to this, the fatigue ductility is reduced by trace element additions even with short running periods. The order in which the metallic trace elements influence the fatigue properties nearly correlates with earlier work concerning Ni- and Co-superalloys. (orig.)

1993-01-01

129

Selective surface aging to improve fatigue behavior in a high-strength beta titanium alloy  

International Nuclear Information System (INIS)

Smooth and notched fatigue behavior is presented for an age-hardenable metastable #beta#-titanium alloy (Ti-3Al-8V-6Cr-4Mo-4Zr). The as-solution heat treated condition exhibits low fatigue limits and high ductility, while the high-strength condition has higher fatigue limits, but poor ductility. A new thermomechanical technique employs shot peening and heat treating to selectively age-harden only the surface. The fatigue limit is improved to levels well above that of the high strength condition, while retaining appreciable ductility, since the bulk material remains in the solution heat treated condition. (orig./MM).

130

Investigation into corrosion fatigue of stainless steels in high concentrated sulfuric acid  

Energy Technology Data Exchange (ETDEWEB)

Four commercial stainless steels (mat. Nos. 1.4539, 1.4586, 1.4571 and 1.4462) were tested in 96% and 90% sulfuric acid of 80/sup 0/C as to their corrosion fatigue strength by subjecting notched round bars to the rotary bending test. At the same time, the efficiency of anodic protection was examined. With all four steels, the alternating bending strength obtained in the air is essentially reduced. The semiaustenitic steel Nr. 1.4462 shows a lower corrosion fatigue strength than the three austenitic steels. Although making the corrosion fatigue strength of steels better calculable, anodic protection proves insufficient to completely prevent notched round bars from corrosion fatigue in concentrated sulfuric acid.

1982-09-01

131

Fatigue and creep-fatigue testing of steam filled tubular Alloy 800 specimens  

Energy Technology Data Exchange (ETDEWEB)

A test program was conducted under contract to Sandia National Laboratories to investigate water/steam effects on elevated temperature low cycle fatigue and creep-fatigue of Alloy 800. This report presents interpretation and analysis of the test results. Tubular specimens with water sealed inside were cycled to failure under strain control. Tests were conducted to 616K (650/sup 0/F) and 922K (1200/sup 0/F); some at 922K included tensile or compressive hold periods to simulate creep-fatigue conditions. The tubular specimens showed significantly lower lives than solid bar specimens cycled at equivalent strain ranges. Rough internal surfaces contributed to early crack initiation with these specimens. Inclusion of hold periods caused further large reductions in cycles to failure.

1982-05-01

132

The Challenge Ahead for Rural Schools.  

Science.gov (United States)

Describes general trends in the quality of rural education: equivalent rural and urban performance on national standardized tests and high school graduation rates but continuing rural deficits in college attendance and teacher qualifications. Discusses the below-average performance of southern rural schools, factors affecting rural students' college attendance, and the influence of changing labor markets. (SV)

1999-12-01

133

Solar-powered humidification dehumidification desalination system  

Energy Technology Data Exchange (ETDEWEB)

Presented are some preliminary studies made in preparation for the design of a solar powered loop for desalination by humidification - dehumidification process. The studies concentrated on the evaluation of different parameters affecting the performance of the combination of different components in such a loop in the hope of outlining the most decisive factors for the choice or design of solar collectors or heat source. The results presented relate to the performance of two of the most important components in a loop of such purpose, that is: the humidifying and the dehumidifying columns or stacks. 4 refs.

1980-01-01

134

Scanning tip microwave near-field microscope  

Energy Technology Data Exchange (ETDEWEB)

A near-field microscope which operates in the rf/microwave frequency range is described. In this microscope, a scanning tunneling microscope (STM)-like tip rather than an aperture is used as a point-like evanescent field emitter. A spatial resolution of {approximately}5 {mu}m ({approximately}{lambda}/100000) is achieved in the current version. The design of the microscope as well as the principal factors which affect its performance are discussed. {copyright} {ital 1996 American Institute of Physics.}

1996-06-01

135

Rural Education in Tasmania.  

Science.gov (United States)

Addresses factors affecting rural education in Tasmania (Australia), including population trends, financial support, student enrollment, socioeconomic status of rural residents, and geographic isolation. Issues that need to be addressed include the status of small schools in Tasmania, costs associated with transporting students, staffing, low student retention, and limited availability of special services. (LP)

1996-12-01

136

Reductive dechlorination of chlorinated solvents by zero-valent iron, iron oxide and iron sulfide minerals  

Energy Technology Data Exchange (ETDEWEB)

The degradation of chlorinated solvents by reduction at the surface of zero-valent metals and bimetallic systems has emerged as an important approach to the in-situ remediation of ground water. Reduction by iron metal was studied in batch and column systems to develop a mechanistic understanding of the reaction chemistry and to determine the factors that affect dechlorination rate and long term performance in field applications.

1996-10-01

137

Friction between different wire-bracket configurations and materials.  

Science.gov (United States)

Friction opposes tooth motion whenever sliding mechanics is employed. Understanding what friction is and how to manage it is of paramount importance to the successful practitioner. In this article, the coefficients of friction are summarized between different arch wire-bracket couples as a function of material, geometric, and external parameters. From this vantage point, friction can then be evaluated within the context of other factors that affect sliding-binding and notching. PMID:9573878

1997-09-01

138

Factors affecting the tensile ductility of a metastable beta titanium alloy  

International Nuclear Information System (INIS)

The ductility of extruded heavy-section Ti-base--Mo--V--Fe--Al alloy was studied. Metallographic evidence for the large effect of grain size on ductility is presented. Fracture was found to occur in large-grain material after less deformation than in smaller grain size specimens.

139

Entrepreneurship in macroeconomics  

British Library Electronic Table of Contents (United Kingdom)

This paper reviews the main studies on entrepreneurship conducted during the past two decades that are relevant for the understanding of various macroeconomic issues. I organize the discussion by distinguishing three groups of contributions. The first group includes studies whose main purpose is to understand the factors that affect the decision to become an entrepreneur. The second group includes studies that look at the aggregate and distributional implications of entrepreneurship for savings and investment. The third group deals with issues of economic development and growth.

2009-01-01

140

Enhancing participation in kitchen waste collections  

Wastenet

...food waste recycling schemes; (3) Six in-depth site visits to authorities operating collection schemes in order to capture information on scheme design, operational issues and factors affecting public engagement. The case study areas were: Bexley, Cambridge, Fenland, Hackney, Taunton Deane and Weymouth & Portland;...

141

Differential decay of parent-of-origin-specific genomic sharing in cystic fibrosis-affected sib pairs maps a paternally imprinted locus to 7q34  

UK PubMed Central (United Kingdom)

Cystic fibrosis (CF) is a monogenic disease characterized by a high variability of disease severity and outcome that points to the role of environmental factors and modulating genes that shape the course...Full Text Available

2010-05-01

142

final report on low-cycle fatigue and creep-fatigue testing of steam-filled alloy 800 specimens  

Energy Technology Data Exchange (ETDEWEB)

Uniaxial low-cycle fatigue and creep-fatigue tests have been carried out on hollow alloy 800 specimens that were filled with steam. Two testing temperatures were employed, each with its own steam condition. These temperatures and steam conditions were 650/sup 0/F with saturated steam (5% liquid, 95% vapor) and 1200/sup 0/F with superheated steam at 2200 psi. The low-cycle fatigue tests were carried out at both 650/sup 0/F and 1200/sup 0/F by cycling the strain between equal tensile and compressive magnitudes until specimen failure or until it was no longer practical to continue the test. The creep-fatigue tests were carried out to failure by cycling the strain in the same fashion as in the low-cycle fatigue tests but with holds imposed at either the peak tensile strain or the peak compressive strain or at both peak tensile and compressive strains in each loading cycle.

1981-02-01

143

Advanced fuzzy logic controllers design and evaluation for buildings' occupants thermal-visual comfort and indoor air quality satisfaction  

Energy Technology Data Exchange (ETDEWEB)

The aim of this paper is to present and evaluate control strategies for adjustment and preservation of air quality, thermal and visual comfort for buildings' occupants while, simultaneously, energy consumption reduction is achieved. Fuzzy PID, fuzzy PD and adaptive fuzzy PD control methods are applied. The inputs to any controller are: the PMV index affecting thermal comfort, the CO{sub 2} concentration affecting indoor air quality and the illuminance level affecting visual comfort. The adaptive fuzzy PD controller adapts the inputs and outputs scaling factors and is based on a second order reference model. More specifically, the scaling factors are modified according to a sigmoid type function, in such a way that the measured variable to be as closer as possible to the reference model. The adaptive fuzzy PD controller is compared to a non-adaptive fuzzy PD and to an ON-OFF ...

2001-07-01

144

Rural Education and the Beginning Teacher.  

Science.gov (United States)

This paper addresses the major issues beginning teachers face in their first postings to rural areas in Australia. The issues go beyond pedagogy. Beginning teachers need to understand social factors affecting rural communities so they can link lessons to the realities experienced by students. Geographic isolation affects the provision of education in terms of time taken to travel, cost, terrain, and technology. Rural communities have groups that are socially isolated from each other and from the staff in schools. In order to teach effectively, teachers need to be aware of the social context of the community in which they live and work. Teachers in rural areas suffer from professional isolation and often confront teaching situations for which they have had little formal preparation. Communities in remote places often move quickly to adopt technological means to overcome their isolation. Teachers in rural areas need to ...

1992-02-01

145

Morphology of wood species affecting wood-thermoplastic interaction: microstructure and mechanical adhesion  

Scientific Electronic Library Online (English)

Abstract in english The main objective of the research presented here is to relate anatomical features of wood species that affect the interactions between polymeric phases and performance of wood plastic composites (WPC). These interactions are related to the probable interlocking volume and surface area for stress transfer in a WPC. Composites were produced from different wood species and analyzed using SEM (scanning electron microscopy). Results showed that wood species with high interfac (more) ial areas may increase mechanical interlocking, reflected in the viscous constant of the Maxwell model. A complicating factor is that the relation of cell wall thickness-lumen diameter and the interconnectivity between wood cells in a wood, affect the potential for cell collapse. When wood cells collapse, the penetration of the thermoplastic into the wood structure is almost always ceased. The collapse of wood cells during ...

2009-01-01

146

Do gender and torus mandibularis affect mandibular cortical index? A cross-sectional study  

Science.gov (United States)

BackgroundThe interactions between torus and several factors such as age, gender, and dental status have not been studied comprehensively. The purpose of this study was to determine the effect of gender on the mandibular cortical index (MCI) and to investigate a possible association between torus mandibularis (TM) and MCI.MethodsThe study consisted of 189 consecutive patients referred to Department of Oral Diagnosis and Radiology of Hacettepe University within 30 workdays. Patients who did not have systemic disorders affecting bone density were included; and the age, gender, dental status and existing TM of the patients were recorded. Morphology of the mandibular inferior cortex was determined according to Klemitti's classification on panoramic radiographs.ResultsMCI was affected by age and gender (P 0.05).ConclusionIn the study population, MCI was affected by age and gender. As age increased, ...

2007-10-30

147

Factors and Issues in Australian Rural Education: A Case for New Perspectives.  

Science.gov (United States)

New interest by Australians in the state of rural education requires new understanding of factors affecting rural education and its related issues. Educational programs have not been flexible enough to cope with rural diversity, a key element in the milieu. Standards such as "equality of opportunity" and "uniformity" have been misapplied to rural Australian education, which is made distinctive by the inter-relatedness of many factors. Three dimensions of isolation are discussed: (1) types of isolation (geographic, cultural, social, and professional isolation); (2) ways of coping with isolation (understanding isolation, developing a sense of community, developing awareness of options, training the isolated, application, and technology); and (3) conditions affecting educational changes in isolated communities (social and political climate, pedagogy, finance, and incentives for change). All these concerns ...

1982-12-01

148

Corrosion fatigue of magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

To study the fatigue life of extruded AZ31 (3%Al, 1%Zn, 0.3%Mn, Mg - the rest), AM50 (5%Al, 0.4%Mn, Mg - the rest) and ZK60 (5%Zn, 0.5%Zr, Mg - the rest) Mg alloys in air and NaCl-based solutions, corrosion fatigue tests were carried out using a rotating beam type fatigue machine. For the analysis of the corrosion fatigue behavior of Mg alloys in different environments, fitted N{sub sol}/N{sub air} ratio considered as a relative corrosion fatigue life is used. Here N{sub sol} and N{sub air} are the numbers of cycles to failure in the solution and in air, respectively. An extruded ZK60 alloy shows very high fatigue and corrosion fatigue properties in comparison with other alloys. However, ZK60 shows the lowest values of the relative fatigue life (N{sub sol}/N{sub air} {proportional_to}10{sup -3}-10{sup -2}) compared to ...

2003-07-01

149

Turbine blades from monocrystalline materials. Part-project: Thermomechanical and isothermal fatigue of the monocrystalline gamma-hardened nickel base superalloys CMSX-6 and SC 16. Final report; Turbinenschaufeln aus Einkristallwerkstoffen. Teilprojekt: Thermomechanisches und isothermes Ermuedungsverhalten der einkristallinen {gamma}`-gehaerteten Nickelbasis-Superlegierungen CMSX-6 und SC16 (Stichversuche). Abschlussbericht  

Energy Technology Data Exchange (ETDEWEB)

Nickel base superalloys for turbine construction are exposed to maximum thermal and mechanical stresses. owing to a change of materials by one of the project partners, the project only comprised analyses of the alloy CMSX-6. Isothermal tensile and fatigue tests provided basic data on the alloy. Thermomechanical fatigue tests showed that material life and microstructural changes are clearly, and to an extreme extent, dependent on the type of combination of the two stress factors `temperature interval` and `total strain amplitude`, while the damage to the material tends to be a function of the maximum stresses for a given stress path. On the one hand, these results make it possible to obtain information real stresses from the structures of real blades. On the other hand, constructional measures can be taken in order to better adapt the stresses to which alloys are exposed to their characteristic potential. (orig./AKF) ...

1997-12-31

150

Behaviour of heat resistant power plant steels undergoing variable long term loading conditions  

Energy Technology Data Exchange (ETDEWEB)

High temperature components of power plants are in many cases subjected to variable loading conditions such as cyclic creep or strain cycling. Therefore the cyclic behaviour of important heat resistant steels has been investigated under stress control and to a smaller extent under strain control. The behaviour under cyclic creep rupture conditions was determined in long term experiments covering a wide range of loading conditions. This behaviour can be described with the modified life fraction rule and a factor concept of relative life for single stage cycles and additionally with a multistep hypothesis for multi-stage cycles. The description can be adapted to estimate the life consumption under service type random conditions. The strain cycling behaviour was investigated in regard to the conditions of the heated surface of large components. To simulate this type of loading and to generate long term creep fatigue data, a service type strain ...

2000-01-01

151

Factors affecting public and political acceptance for the implementation of geological disposal  

International Nuclear Information System (INIS)

This publication identifies conditions which affect (either increase or decrease) public concern for and political acceptance of the development and implementation of programmes for geological disposal of long lived radioactive waste. It also looks at how interested citizens can be associated in the decision making process in such a way that their input enriches the outcome of a more socially robust and sustainable solution. The publication also considers how to optimize risk management, addressing the needs and expectations of the public and of other relevant stakeholders. Factors of relevance for societal acceptance conditions are identified for the different stages of a repository programme and implementation process, from policy development to the realization of the repository itself. Further, they are described and analysed through case studies from several countries, illustrating the added value of broadening the technical dimension with ...

2009-09-01

152

Study on regional production and economy of cobia Rachycentron canadum commercial cage culture  

British Library Electronic Table of Contents (United Kingdom)

In recent years, cobia has become an emerging farmed species in Asia due to its quick growth and high economic value. This study collects biological and economic data affecting the economic performance of cobia farming in three countries, namely Taiwan, China, and Vietnam. The data are collected by questionnaire sampling and analyzed by multivariate statistical analysis in order to compare the key factors affecting the production and economy of cobia farming in these three countries. The results show that Taiwan, China, and Vietnam have significant differences in input intensities and profitability. China has the highest input intensity (3372.42?TWD/m3), as its high stocking density increases feed input. Taiwan has the highest unit input cost (103.44?TWD/kg), as the high quality of the pro...

2011-01-01

153

Strikingly different penetrance of LHON in two Chinese families with primary mutation G11778A is independent of mtDNA haplogroup background and secondary mutation G13708A  

British Library Electronic Table of Contents (United Kingdom)

The penetrance of Lebers hereditary optic neuropathy (LHON) in families with primary mitochondrial DNA (mtDNA) mutations is very complex. Matrilineal and nuclear genetic background, as well as environmental factors, have been reported to be involved in different affected pedigrees. Here we describe two large Chinese families that show a striking difference in the penetrance of LHON, in which 53.3% and 15.0% of members were affected (Pin vivo mitochondrial oxidative metabolism as described in a previous study. Evolutionary analysis failed to indicate any putatively pathogenic mutation that cosegregated with G11778A in these two pedigrees. Our results suggest that the variable penetrance of LHON in the two Chinese families is independent of both their mtDNA haplotype background and a seconda...

2008-01-01

154

Investigation of factors affecting the diffusion of mobile telephone services: An empirical analysis for Vietnam  

British Library Electronic Table of Contents (United Kingdom)

This paper analyzes the diffusion of mobile telecommunications services in Vietnam and examines how telecommunications regulation and potential substitute/complement services affect the growth of the number of mobile telephone subscribers. Using a logistic diffusion model, it is found that fixed telephone services are a complement while data services have a negative relation to mobile telephone services in Vietnam. As for regulation, the policy of introducing competition has been found to be the most effective in influencing the adoption of mobile services. Another important result is that the estimated potential market is roughly 76% of the total population. The findings suggest that suitable regulation that guarantees competition in the mobile telecommunications market in a developing co...

2009-01-01

155

Crop diversification and trade liberalization: Linking global trade and local management through a regional case study  

British Library Electronic Table of Contents (United Kingdom)

Some models anticipate that liberalized agricultural trade will lead to increased crop diversity, while other models make the opposite claim. These positions were explored in southwestern British Columbia, Canada where, between 1992 and 1998, government subsidies and other measures designed to protect horticultural farmers were lifted, exposing these farmers to foreign competition. Public hearings on the future of agriculture provided an opportunity to tap the knowledge and experience of people affected by this transition. Analysis of transcripts from these hearings, which was confirmed by industry data, shows that trade liberalization has led to the loss of the local fruit and vegetable processing industry. Stakeholders saw the loss as a major factor affecting the choice of crops grown lo...

2006-01-01

156

The effect of the changing microstructure on the fatigue behaviour during cyclic rolling contact loading  

Energy Technology Data Exchange (ETDEWEB)

During rolling contact fatigue of the inner rings of ball bearings three stages of material response can be distinguished, in terms of the volume that is plastically deformed upon overrolling. After a first stage of material strengthening during which a decrease occurs for the volume that is deformed plastically, an effectively stationary, second stage is entered which is eventually succeeded by a third stage exhibiting a pronounced increase of the volume that is deformed plastically upon overrolling, which leads to failure. It is suggested that carbon diffusion induced by local temperature peaks occurring at the moment of overrolling is the key mechanism leading to fatigue damage. The amount of decomposed retained austenite is a useful, practical parameter to assess fatigue life. It is shown that published ideas about the role of certain components of residual stress in enhancing fatigue life are not ...

1997-04-01

157

Microstructure fracture toughness and fatigue crack growth rate in titanium alloys; Proceedings of the 1987 TMS-AIME Annual Symposium, Denver, CO, Feb. 24, 25, 1987  

Science.gov (United States)

The papers contained in this volume provide an overview of recent theoretical and experimental research related to the fracture toughness and fatigue crack growth characteristics of titanium alloys. Topics discussed include room temperature fatigue crack propagation in beta-titanium alloys, fatigue crack growth rate acceleration in alpha+beta Ti alloys, influence of transformed beta microstructures on fatigue crack growth rates in Ti-6Al-4V, and the role of inclusion and pore content on the fracture toughness of powder processed blended elemental Ti-10V-2Fe-3Al. Papers are also presented on fatigue crack growth measurements in an alpha-beta titanium alloy, the effects of thermal processing variation on the properties of Ti-6Al-4V, and the effect of microstructure on ductility and fracture toughness of alpha+beta titanium alloys.

1987-01-01

158

Microscopic investigations of microcrack formation in two ferritic-martensitic steels in nonirradiated and irradiated conditions; Mikroskopische Untersuchung der Bildung von Ermuedungsrissen an zwei ferritisch-martensitischen Staehlen im unbestrahlten und vorbestrahlten Zustand  

Energy Technology Data Exchange (ETDEWEB)

The low-cycle fatigue properties of the ferritic-martensitic steels MANET I and II and F82H-mod, have been investigated at a temperature of 200 C. The strain-controlled fatigue has been performed with strain ranges between 0,4% and 1,0% and at a strain rate of 8.10{sup -4} s{sup -1}. The steel F82H-mod, is characterised by a higher plastic strain amplitude compared to MANET I and II. Some of the specimens have beenirradiated with a 104 MeV {alpha}-particle beam. The homogeneous implantation of 400 appm He leads to a hardening of the material. At the beginning of the fatigue tests the stress response of the irradiatedspecimens is higher compared to the unirradiated specimens. In general, thematerial shows softening during fatigue. The softening of irradiated material, which is fatigue tested with a high total strain amplitude, is higher than that of the unirradiated material. The ...

1997-09-01

159

Fatigue crack detection in aircraft skin structures using eddy current array technique  

International Nuclear Information System (INIS)

Detection of fatigue damage cracks in aircraft skin structures is an ongoing NDT challenge. Cracks growing rate is difficult to predict, and for this reason, it is important to detect them as soon as possible to avoid a catastrophic break. Eddy current methods are known and well-accepted techniques which are relatively simple to carry out. However, with conventional inspection of airframe structures using standard driver-pickup eddy current probes, it is difficult to detect small fatigue cracks initiated in the second layer of the skin and in the shadow region at fastener holes. Such difficulty is related to fasteners length and their spacing which reduces test sensitivity. This report explains the development of improved eddy current probe/technique to detect and visualize fatigue cracks in fasteners. In this study, an eddy current array probe was evaluated and new coil design was suggested. Several tests were conducted on ...

2004-01-01

160

Effect of fatiguing exercise on longitudinal bone strain as related to stress fracture in humans.  

Science.gov (United States)

Muscular fatigue in the training athlete or military recruit has been hypothesized to cause increased bone strain that may contribute to the development of a stress fracture. Under normal circumstances, muscles exert a protective effect by contracting to reduce bending strains on cortical bone surfaces. In vivo strain studies in dogs show that muscle fatigue following strenuous exercise elevates bone strain and changes strain distribution. However, a similar experiment has yet to be performed in humans. The purpose of this work was to test the hypothesis in humans that strenuous fatiguing exercise causes an elevation in bone strain. It was also hypothesized that this elevation is greater in younger people than in older people due to the decline in muscle strength and endurance that normally occurs with age. To test these hypotheses, strain in the tibiae of seven human volunteers was measured during walking before and after ...

161

Alloy 800: Low cycle fatigue curves as the basis for design against fatigue failure of HTR components  

Energy Technology Data Exchange (ETDEWEB)

For a reliable design against fatigue failure of high-temperature components of different types of the heat resistant material Alloy 800, verified parameters of the low-cycle fatigue (LCF) behaviour are required. These parameters were obtained by a scatterband evaluation of the results of low-cycle fatigue tests, using a computerized data bank which includes all available actual data sets. The results of the evaluation are presented as mean fatigue curves with the upper and lower boundary limits of the scatterbands. For the type Alloy 800 in the recrystallization annealed condition, the results cover a temperature range from 20 to 750deg C; for the solution annealed types they cover a temperature range from 20 to 950deg C. Specimens tested in HTR helium at high temperatures had longer lives than specimens tested in air. This effect was represented quantitatively by the ratio of the total strain ranges ...

1990-05-01

162

On the fatigue threshold behaviour of two ferrite-pearlite microalloyed steels  

Energy Technology Data Exchange (ETDEWEB)

Long crack fatigue threshold ({delta} K{sub th}) and crack closure behaviour of two thermomechanically processed microalloyed (MA) ferrite-pearlite steels are reported. {delta} K{sub th} and crack closure were measured using a dynamic compliance measurement technique. Crack closure was observed at low load ratios (R < 0.5) and the fatigue thresholds decreased with increasing load ratio. In both steels, the closure-free intrinsic threshold ({delta} K{sub eff} {sub th}) was found to be independent of the load ratio. (orig.)

2000-07-01

163

Lifetime and fatigue limit prediction for components of high strength steels; Vorhersage der Lebensdauer und Dauerfestigkeit von Bauteilen aus hochfesten, durchhaertenden Staehlen  

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N-curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle-fatigue, crack initiation was most likely caused by inclusions like Titanium Carbonitrides or Aluminium Oxides. A model was developed to describe the influence of the magnitude of these inclusions on the lifetime. A weakest link model, using the statistical distribution of inclusions and surface flaws, was used to describe the fatigue limit. (orig.)

2000-07-01

164

Characteristics of U-tube assembly design for CANDU 6 type steam generators  

Energy Technology Data Exchange (ETDEWEB)

Since the first operation of nuclear steam generator early 1960s, its performance requirements have been met but the steam generator problems have been met but the steam generator problems have been major cause of reducing the operational reliability, plant safety and availability. U-tube assembly of steam generator forms the primary system pressure boundary of the plant and have experienced several types of tube degradation problems. Tube failure and leakage resulting from the degradation will cause radioactive contamination of secondary system by the primary coolant, and this may lead to unplanned plant outages and costly repair operations such as tube plugging or steam generator replacement. For the case of steam generators for heavy water reactors, e.g. Wolsong 2, 3, and 4 NPP, a high cost of heavy water will be imposed additionally. During the plant operation, steam generator tubes can potentially be subject to adverse environmental conditions which will cause damages to U-tube ...

1996-06-01

165

Physiological Considerations of Fatigue  

Science.gov (United States)

your eye to the SCN in your brain, so that light ... Owls are individuals who go to bed late, like to get up late in the moming. And the moming types, ...

166

NATIONALAIIVISBRY COMMITTEE Ffltt AERONAUTICS - NASA Technical ...  

Science.gov (United States)

Watkins,. Charles. E. : Effect of Aspect. Ratio on the Air ...... Grover,. H. 3. ; Bishop,. S. M. ; and. Jackson,. L. R. : Fatigue. Strengths of Aircraft ...

167

Experimental Investigation into the Fatigue Life of Hybrid ...  

Science.gov (United States)

... asymmetric versions of two different methods of joining GRP composite sandwich panels 3with steel were obtained (see Figure 1.7), the idea being ...

2008-06-01

168

A Magnetic Suspension and Excitation System for Spin Vibration ...  

Science.gov (United States)

High Cycle Fatigue Initiative Workshop -Active Vibration. Control/Engine. Health Monitoring Session December 10,. 1996. The presentation was titled "Active ...

169

Influence of organizational factors on performance reliability  

International Nuclear Information System (INIS)

This is the first volume of a two-volume report. Volume 2 will be published at a later date. This report presents the results of a research project conducted by Brookhaven National Laboratory for the United States Nuclear Regulatory Commission, Office of Nuclear Regulatory Research. The purpose of the project was to develop a general methodology to be use in the assessment of the organizational factors which affect performance reliability (safety) in a nuclear power plant. The research described in this report includes the development of the Nuclear Organization and Management Analysis Concept (GNOMIC). This concept characterizes the organizational factors that impact safety performance in a nuclear power plant and identifies some methods for systematically measuring and analyzing the influence of these factors on safety performance. This report is divided into two parts; Part 1 presents an overview of ...

170

Development of the heated length to diameter correction factor on critical heat flux using the artificial neural networks  

Energy Technology Data Exchange (ETDEWEB)

With using artificial neural networks (ANNs), an analytical study related to the heated length effect on critical heat flux (CHF) has been carried out to make an improvement of the CHF prediction accuracy based on local condition correlations or table. It has been carried out to suggest a feasible criterion of the threshold length-to-diameter (L/D) value in which heated length could affect CHF. And within the criterion, a L/D correction factor has been developed through conventional regression. In order to validate the developed L/D correction factor, CHF experiments for various heated lengths have been carried out under low and intermediate pressure conditions. The developed threshold L/D correlation provides a new feasible criterion of L/D threshold value. The developed correction factor gives a reasonable accuracy for the original database, showing the error of -2.18% for average and 27.75% for RMS, ...

1998-12-31

171

Structural Equation Modeling for High School Principals' Data-Driven Decision Making: An Analysis of Information Use Environments  

Science.gov (United States)

Background: Accountability demands are increasingly pushing school leaders to explore more data and do more sophisticated analyses. Data-driven decision making (DDDM) has become an emerging field of practice for school leadership and a central focus of education policy and practice. Purpose: This study examined principals' DDDM practices and identified the factors influencing DDDM using the theoretical frame of information use environments. Participants: Participants were 183 public high school principals in a Midwestern state. Research Design: The research design was cross-sectional survey research. Data Collection and Analysis: Survey instruments were developed and administered to principals. Structural equation modeling was conducted to determine what factors significantly affect principals' DDDM practices in different leadership dimensions. Findings: Principals used data more frequently in instructional and organization ...

2007-12-01

172

Understanding the determinants of cloud computing adoption  

British Library Electronic Table of Contents (United Kingdom)

Purpose - The purpose of this paper is to investigate the factors that affect the adoption of cloud computing by firms belonging to the high-tech industry. The eight factors examined in this study are relative advantage, complexity, compatibility, top management support, firm size, technology readiness, competitive pressure, and trading partner pressure. Design/methodology/approach - A questionnaire-based survey was used to collect data from 111 firms belonging to the high-tech industry in Taiwan. Relevant hypotheses were derived and tested by logistic regression analysis. Findings - The findings revealed that relative advantage, top management support, firm size, competitive pressure, and trading partner pressure characteristics have a significant effect on the adoption of cloud computing...

2011-01-01

173

Teaching medicine and allied disciplines in the 21st century--lessons from Ireland on the continuing need for reform  

Energy Technology Data Exchange (ETDEWEB)

This article identifies the imperatives behind the need to move away from teaching based on the transmission of a lot of facts to teaching that enables students to become lifelong learners. It reminds us that the over-riding goal is an education process that maximizes the ability of teachers to teach well and of students to learn effectively. It argues that the necessary reform process can only be successful if the three components of an education programme--the curriculum, teaching strategies and assessment--are reformed simultaneously to ensure that each is designed to produce more effective teaching and learning. It points to the literature that tells us what we know about factors affecting student behaviour and, in particular, notes the crucial factor of student perception of the requirement of the assessment regime. It recommends that Biggs' model of constructive alignment is used as the organizing principle ...

2005-02-01

174

Prognostic patients with value of some factors in therapy of patients with reticulosarcoma Ewing's sarcoma and solitary myeloma of pelvic bones  

International Nuclear Information System (INIS)

Effect of different factors on survival of patients with Ewing sarcoma (20 people), primary bone reticulosarcoma (43) and myeloma (10) of pelvic bones, has been studied. Independently of the method of treatment, the rate of 3-year survival from reticulosarcoma start constituted (31.5+-7.1)%, Ewing sarcoma - (33.0+-10.8)%, myeloma - (36.0+-15.9)%. Index of 5-year survival in case of reticulosarcoma constituted (20.9+-6.4)%, Ewing sarcoma - (23.6+-11.0)%, myeloma - (36.0+-15.9)%. Improvement of delayed results after prophylactic therapy courses is pointed out. Degree of pelvic bone affection is of a very important prognostic value.

175

Factors affecting the intentions of customers in Malaysia to use mobile phone credit cards  

British Library Electronic Table of Contents (United Kingdom)

Purpose - Mobile phones have provided an opportunity for banking institutions to introduce new services to the public. The latest service, which is now available in Malaysian banking institutions, is the mobile phone credit card. The purpose of this paper is to provide a preliminary investigation of the factors that determine whether Malaysia's bank customers will use the new mobile phone credit card technology. Design/methodology/approach - This paper extends the applicability of the technology acceptance model (TAM) to mobile phone credit cards and includes "perceived credibility (PC)", the "amount of information about mobile phone credit cards (AIMCs)" and "perceived expressiveness (PE)", in addition to "perceived usefulness (PU)" and "perceived ease of use (PEOU)". Findings - The resul...

2008-01-01

176

Economic comparison of clean coal generating technologies with natural gas-combined cycle systems  

International Nuclear Information System (INIS)

This paper reports that there are four combustion technologies upon which U.S. electric utilities are expected to rely for the majority of their future power generating needs. These technologies are pulverized coal- fired combustion (PC); coal-fired fluidized bed combustion (AFBC); coal gasification, combined cycle systems (CGCC); and natural gas-fired combined cycle systems (NGCC). The engineering and economic parameters which affect the choice of a technology include capital costs, operating and maintenance costs, fuel costs, construction schedule, process risk, environmental and site impacts, fuel efficiency and flexibility, plant availability, capacity factors, timing of startup, and the importance of utility economic and financial factors.

1990-04-23

177

Chronic and non-communicable diseases: a critical challenge for nurses globally  

British Library Electronic Table of Contents (United Kingdom)

ALLEYNE G., HANCOCK C. & HUGHES P. (2011) Chronic and non-communicable diseases: a critical challenge for nurses globally. International Nursing Review58, 328-331 Background:- Chronic and non-communicable diseases (NCDs) are a growing and enormous challenge that faces countries across the world. Low- and middle-income countries are disproportionately affected. Contributory factors:- Three risk factors - tobacco use, poor diet (including excessive alcohol intake) and lack of physical activity - contribute to four major chronic diseases - cardiovascular, chronic obstructive pulmonary disease, diabetes and some cancers, which are responsible for over 50% of deaths worldwide. Potential solutions:- International governmental and non-governmental agencies are becoming increasingly concerned and ...

2011-01-01

178

Chemical plant factors affecting resistance in sugarcane in against Scirpophaga Nivella f  

International Nuclear Information System (INIS)

The study was conducted during 2000 to determine the role of various chemical plant factors viz., total minerals, nitrogen, fat contents, carbohydrate, macro an micro nutrients in the leaves of five genotypes of sugarcane i.e., BF-162, SPSG-26, L-118, CP-43/33 and CP-72/2086 by correlating the infestation of top borer, Scirpophaga Nivella F. at tillering stage. None of the genotype was found completely resistant to the pest. CP-43/33 and BF-162 proved susceptible and resistant varieties, respectively. Total mineral, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents played a positive and significant role. Phosphorous, carbohydrates, fats and zinc contents played a significant and negative effect on the pest infestation at tillering stage. (author)

179

Activity of ginsenoside Rh2 on the growth of mice splenic lymphocytes investigated by microcalorimetry and factor analysis  

British Library Electronic Table of Contents (United Kingdom)

The power?time curves of mice splenic lymphocytes growth at 37??C affected by ginsenoside Rh2 were determined by microcalorimetry using a 3114/3236 TAM air bioactivity monitor with ampoule mode. Then, the minimal inhibitory concentration (MIC) of Rh2 on splenic lymphocytes growth was determined by serial dilution method. From factor analysis (FA) on six quantitative thermokinetic parameters from the power?time curves, the activity of Rh2 on splenic lymphocytes could be quickly evaluated by analyzing the changes in the two main parameters: growth rate constant k, and maximum heat-output power, P m. The results showed that Rh2 had strong inhibitory activity on splenic lymphocytes growth, and this inhibitory activity was strengthened with increasing concentration of Rh2 in the concentration r...

2011-01-01

180

A numerical study of expected accuracy and precision in Calibration-Free Laser-Induced Breakdown Spectroscopy in the assumption of ideal analytical plasma  

British Library Electronic Table of Contents (United Kingdom)

Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experi...

2007-01-01

181

Mechanisms mediating the trophic effect of nerves during vertebrate limb regeneration  

Energy Technology Data Exchange (ETDEWEB)

Salamanders regenerate their appendages after amputation and nerves are required for this process. Experiments were designed to test the idea that one way nerves could affect blastema cell proliferation is by influencing the metabolism of extracellular matrix (ECM) components and to identify neurotrophic factors which promote blastema cell mitosis. Temporal and spatial differences of glycosaminoglycans (GAGs) synthesis is innervated and denervated limbs were examined. Hyaluronic acid (HA) was found to be the major GAG produced during the proliferative period and chondroitin sulfate during differentiation. Denervation reduced synthesis of both these components by half. Dorsal root ganglia and fibroblast growth factor (FGF), a brain-derived mitogen, similarly doubled GAG synthesis in cultured blastemas, the FGF-effect being primarily on HA production. Histochemical and autoradiographical results confirmed the biochemical ...

1986-01-01

182

Washington: a guide to geothermal energy development  

Energy Technology Data Exchange (ETDEWEB)

A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

1980-01-01

183

Thermal degradation and crystallisation studies of reactively compatibilised polymer blends  

British Library Electronic Table of Contents (United Kingdom)

The thermal degradation and crystallisation behaviours of polyamide12/isotactic polypropylene (PA12/PP) blends were studied. Effects of blend ratio and compatibiliser concentration on the thermal degradation properties of the blends were analysed. The activation energy for degradation in compatibilised and uncompatibilised blends computed using Horowitz-Metzger equation was reported. The blend ratio as well as the presence of compatibiliser has significant effect on the thermal stability of the blends. Phase morphology was found to be one of the decisive factors that affected the thermal stability of both uncompatibilised and compatibilised blends. Melting and crystallisation behaviours of the blends in the presence and absence of compatibiliser were evaluated. It was observed that blendin...

2008-01-01

184

The root cause analysis of 9DVN002ZV fan failure in Daya Bay Nuclear Power Station  

International Nuclear Information System (INIS)

Extensive investigations and detailed analysis of the failure reason of 9DVN002ZV fan in Daya Bay Nuclear Power Station showed that the fan destroy was caused by the failure of non-drive end bear. The direct cause of this bearing' failure was its improper assembly caused by improper maintenance procedure, and the root cause was too small internal radial clearance after mounting. The factor affecting bearing internal radial clearance, the relationship between clearance and operating life time and fan failure process were discussed. (authors)

2005-09-01

185

Snake River Fall Chinook Salmon Life History Investigations, Annual Report 2008.  

Energy Technology Data Exchange (ETDEWEB)

This study was initiated to provide empirical data and analyses on the dam passage timing, travel rate, survival, and life history variation of fall Chinook salmon that are produced in the Clearwater River. The area of interest for this study focuses on the lower four miles of the Clearwater River and its confluence with the Snake River because this is an area where many fish delay their seaward migration. The goal of the project is to increase our understanding of the environmental and biological factors that affect juvenile life history of fall Chinook salmon in the Clearwater River. The following summaries are provided for each of the individual chapters in this report.

2009-09-15

186

Passive dosimetry of radon and its daughters using solid state nuclear track detectors (SSNTDs)  

Energy Technology Data Exchange (ETDEWEB)

Indoor radon is a potential health hazard for the general public, especially in buildings with poor ventilation. A variety of dosemeters have been developed and used in surveys of radon concentration measurements. In this article the passive dosemeters which are based on solid state nuclear track detectors are reviewed. The principle of passive dosimetry and the factors affecting their performance are discussed. The characteristics of SSNTD materials in relation to their behaviour under different environmental conditions are tabulated and discussed. Results of radon surveys from selected studies are also presented. (Author).

1993-01-01

187

Multiple stress aging of solid-dielectric extruded dry-cured insulation systems for power transmission cables  

Energy Technology Data Exchange (ETDEWEB)

A detailed examination of the aging processes that may take place in solid-dielectric extruded-type high voltage transmission cables under dry conditions is presented. Particular emphasis is placed on the aging process as affected by the separate and simultaneous action of four main aging factors, namely the electrical, mechanical and thermal stresses, and the physical and chemical environment. A number of pertinent aging models are considered and their validity and applicability to accelerated aging tests on solid-type transmission cables are discussed.

1994-01-01

188

Measuring preferences for low-carbon energy technologies in South-East England: the case of electricity generation  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a survey on public preferences in SE England for the use of wind, biomass and nuclear power in electricity generation. Using a labelled CE the perceived importance (value) to the public of distance and the energy options' impacts on biodiversity, emissions, land occupation and household cost was explored. Results suggest that impacts, technology name, demographic characteristics, attitudes towards the environment, knowledge and experience with the technologies were significant choice determinants. Considering the current debate about the development of nuclear power and biomass in UK and worldwide, this survey provides an insight into the factors affecting public acceptability

2008-07-01

189

GaInP[sub 2]/GaAs tandem cells: Problems and solutions  

Energy Technology Data Exchange (ETDEWEB)

The various factors that affect the open-circuit voltage ([ital V][sub oc]) of a two-terminal GaInP[sub 2]/GaAs tandem cell are examined. These include a) an anomalous problem associated with the GaAs bottom cell and b) back surface passivation of the thin GaInP[sub 2] top cell. Solutions to these problems are presented and yield tandem [ital V][sub oc]s close to the practical theoretical limits.

1992-12-01

190

Design standards No. 4: Electrical apparatus and systems. Chapter 1. General considerations for power, pumping, and pumped-storage plants. Final report  

Energy Technology Data Exchange (ETDEWEB)

The purpose of the chapter is to explain briefly the various considerations that enter into determining the general layout or arrangement of typical hydroelectric powerplants, pumping plants, and pumped-storage plants. Some of the important factors that affect or determine the location, type, and layout of the plant and the selection of the major items of equipment included in the installation are outlined in this chapter. The first consideration in the design of a powerplant, pumping plant, or pumped-storage plant is that it adequately perform its function and be structurally safe. The structure is also designed to give a pleasing architectural appearance.

1985-05-01

191

Computer Simulation of Factors Affecting Rural Education.  

Science.gov (United States)

Computer simulations of agricultural finance and management may be helpful to students preparing for agricultural careers. Simulations would provide problem definition and problem solving in realistic interactions with complex and ambiguous situations similar to those encountered in farming. The paper describes a major financial problem for farmers, explores the implications of that problem for students, and outlines a computer-based simulation model which would give students experience in dealing with the problem. Data sources for simulations, potentials of interactive exercises among students, and advantages of using real data with existing ambiguities are described. The board game "AGRICULTURE" is discussed as a prototype for simulation. (LFL)

1986-02-01

192

Automatic fuzzy decision making system with learning for competing and connected businesses  

British Library Electronic Table of Contents (United Kingdom)

We study uncertainties surrounding competition on business networks and board games. We investigate these uncertainties using concepts of fuzzy logic and game theory. We investigate how the payoff of the players is affected by a number of factors. These include the level of connectivity or number of links, the number of competitors, possible constraints on the networks and on the boards, as well as choice of strategy adopted by competitors. We introduce one fuzzy player in the game. This player uses fuzzy rules to make strategic decisions. We introduce learning to train and analyze how the fuzzy player adapts over time during the game.

2011-01-01

193

Alaska: a guide to geothermal energy development  

Energy Technology Data Exchange (ETDEWEB)

A brief overview is given of the geological characteristics of each region of the state as they relate to potential geothermal development. Those exploration methods which can lead to the siting of a deep exploration well are described. Requirements and techniques needed for drilling deeper higher temperature exploration and production wells are presented. Electrical generation, direct utilization, and indirect utilization are reviewed. Economic factors of direct use projects are presented. A general guide to the regulatory framework affecting geothermal energy development is provided. The general steps necessary to gain access to explore, develop, distribute, and use geothermal resources are outlined. (MHR)

1980-06-01

194

A high stopping power, large acceptance Bragg curve spectrometer for heavy ion detection  

Energy Technology Data Exchange (ETDEWEB)

A large acceptance, high stopping power Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. Factors affecting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

1991-05-01

195

A high stopping power, large acceptance Bragg curve spectrometer for heavy ion detection  

International Nuclear Information System (INIS)

A large acceptance, high stopping power Bragg curve spectrometer has been developed for use in coincidence experiments with heavy ions. The electron collection fields are radial and position information is obtained from a resistive anode. The detector is 60 cm deep and operates at pressures of up to 2.5 atm of P-10 gas. It is mated to a scattering chamber which allows it to be moved out of plane during coincidence measurements. Factors affecting the performance of the detector are discussed, and results obtained with the detector are presented. (orig.).

196

A conceptual model for laboratory ventilation greenhouse gas planning  

British Library Electronic Table of Contents (United Kingdom)

There is increasing pressure to operate laboratory facilities in environmentally and financially sustainable ways. A key factor in achieving this goal is careful consideration of how energy is used by the buildings' ventilation system, both for conditioning air supplied to the laboratories and the energy used moving air through the building. Traditionally, laboratory energy use is treated as an engineering concern within the scope of the building's overall design and operation. However, this approach limits the involvement of key stakeholders in many important decisions and can lead to unexpected safety concerns for the laboratory's users. We believe that a broad view of the parties affected by a laboratory building's operations is necessary to avoid having the various stakeholders working...

2011-01-01

197

Moving Towards Inclusive Education Policies and Practices? Basic Education for AIDS Orphans and Other Vulnerable Children in Zambia  

Science.gov (United States)

The global spread of HIV and AIDS has presented a major threat to development, affecting the health of the poor and many aspects of social and economic development. The greatest impact of the epidemic has been felt in sub-Saharan Africa, and Zambia ranks among the worst hit countries. The Free Basic Education Policy in Zambia upholds the right of all children to a universal basic education. This study explored staff and student perceptions of the impact of the epidemic on access to, and the quality of, basic education for AIDS-affected children, orphans and other vulnerable children (OVCs) in the Copperbelt Province of Zambia, where the HIV/AIDS prevalence rate ranges from 34 to 40%, and life expectancy has dropped to 33 years. Data were collected from education personnel in six districts of the Copperbelt with the highest prevalence of HIV and AIDS and from staff and students in six schools. The data indicated a range of ...

2007-07-01

198

Percutaneous transluminal angioplasty and thrombolysis in the management of insufficient hemodialysis access: Long-term patency rates and factors affecting patency rates  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the success rates, long-term patency rates and factors affecting the patency rates of percutaneous transluminal angioplasty(PTA) and thrombolysis in the management of insufficient access during hemodialysis. Between January 1991 and March 1995, 37 insufficient shunts(23 native fistulae and 14 graft fistulae) were treated in 31 patients. PTA was performed in 24 shunts, and thrombolysis in 13;in seven of these latter, thrombolysois was followed by PTA. The success and long-term patency rates of PTA and thrombolysis were evaluated. Shunts were subdivided according to a patient's age, type and age of the shunt, and number and length of the stenosis, and the degree of residual stenosis and in each subgroup, patency rates was compared. The overall success rate of PTA and thrombolysis for insufficient hemodialytic access was 78.4%(29/37). The success rates of PTA and thrombolysis were 91.7%(22/24) and 53.8%(7/13), respectively. ...

1997-10-01

199

Chronic fatigue syndrome, XMRV and blood safety  

British Library Electronic Table of Contents (United Kingdom)

In the past few months, there has been public discussion relating to a new perspective on blood safety and specifically upon measures to prevent or discourage donation by individuals with a diagnosis of myalgic encephalopathy-chronic fatigue syndrome. This reflects an intriguing interplay between science, public health and public concern and illustrates some of the difficulties of making decisions in the face of uncertainty and inadequate information.

2011-01-01

200

Thermal fatigue of stainless steel  

Energy Technology Data Exchange (ETDEWEB)

Two austenitic steels, 316 Stainless Steel and Alloy 800, have been examined under conditions of both isothermal low cycle fatigue (LCF) and thermomechanical fatigue (TMF). The TMF tests were conducted between 649 and 360/sup 0/C with a carefully controlled triangular waveform. The LCF tests were performed at 649/sup 0/C and both kinds of tests were subjected to a strain range of 0.5%. TMF shortened life to 40% for 316 Stainless Steel and to 5% for Alloy 800. The microstructural evolution occurring in both alloys has been examined and we conclude these do not play a role in the life shortening caused by TMF. The TMF does produce asymmetric hysteresis loops with large tensile peak stresses in tests where the maximum temperature corresponded with the peak compressive stress. The influence of TMF on fatigue crack growth rates has been measured and it was found that TMF accelerated crack growth in Alloy 800 and slowed it down ...

1987-12-01

201

Prediction of fatigue crack growth behaviour of an #alpha#-#beta# titanium alloy in Paris-regime using LCF properties  

International Nuclear Information System (INIS)

A model has been developed in the recent past to predict fatigue crack growth (FCG) behaviour in the Paris-regime of various steels by employing low cycle fatigue (LCF) properties. The model forms its basis on the assumption that the cyclic damage process immediately ahead of a crack-tip, restricted in a small zone termed as process zone, is identical to those experienced in the LCF loading of a smooth specimen. Within the process zone, fatigue damage has been assumed in terms of product of stress and plastic strain which is analogous to the plastic strain energy density of the smooth specimen under fatigue loading. In this paper the model developed by Kujawski and Ellyin has been used to predict the FCG behaviour of an #alpha#-#beta# titanium alloy in the Paris-regime by employing the experimentally obtained LCF properties. The FCG behaviour thus theoretically predicted was compared with the ...

202

In-situ and post-irradiation fatigue properties of the ferritic-martensitic steel Manet at T=250 C  

Energy Technology Data Exchange (ETDEWEB)

Strain controlled fatigue experiments on the modified ferritic-martensitic 12% Cr-steel Manet have been performed during, after and without irradiation. Continuous push-pull cycling of the hollow fatigue specimens with a cycle ratio R=-1, an axial strain rate of 8.10{sup -4} s{sup -1} and total strain ranges {Delta}{epsilon}{sub t} between 0.42% and 1.0% has been applied in vacuum (5.10{sup -3} Pa) at T=250 C. For the irradiation, a 104 MeV {alpha}-particle beam was used. Compared to unirradiated specimens, in-beam specimens undergo irradiation hardening at an advanced fatigue/implantation stage. Post-irradiation specimens show significantly higher total stress amplitudes and reduced fatigue lives. TEM investigations of in-beam and post-irradiation specimens reveal helium bubbles with different diameters on internal surfaces and in the matrix. (orig.).

1996-10-01

203

Fatigue properties of magnesium alloy under biaxial stress  

Energy Technology Data Exchange (ETDEWEB)

Machines and structures, such as automobiles are usually subjected to biaxial or three-axial stresses instead of uniaxial stress. However, research on a fatigue failure under multi-axial stress has not been fully presented because such experiments are difficult. To solve this problem, we developed the servo biaxial fatigue-testing machine. In this research, we performed the biaxial fatigue tests of a magnesium alloy in order to clarify the effects from different heat treatments. Magnesium alloy is the lightest in weight among metal materials for structural use. The fatigue characteristics of a magnesium alloy are indispensable in order to create the design which ensures the reliability and the safety of the vehicles especially in long-distance run. The main conclusions are summarized as follows; (1) The mechanical property of magnesium alloy AZ31B falls by heat treatment at low temperature. (2) The ...

2004-07-01

204

Fatigue crack growth in steam turbine rotor steels in near realistic media  

International Nuclear Information System (INIS)

In this study, growth measurements of fatigue cracks in air and various simulated media for steam turbines were made by means of rupture-mechanical methods. In this connection, it was detected that even pure water leads to a clear increase in the fatigue crack rates of low-pressure rotor steels. In this connection, it was striking to observe that the crack propagation velocities at 100"0C were higher than at 160"0C. It is probable that the kinetics of the film formation at the crack tip was of importance. The inhibiting effect of the alkaline solutions is explained by the increasing stability of a film of Fe(OH)_2 at an increased pH value. Neither the frequency response nor the fractographic result indicate an influence of the stress crack corrosion. This can be explained by the fact that the incubation period (= the period to initiate an intercrystalline crack caused by stress crack corrosion at a transcrystalline fatigue ...

1988-03-17

205

The effects of surface damage on RF cavity operation  

Energy Technology Data Exchange (ETDEWEB)

We describe a model of damage in rf cavities and show how this damage can limit cavity operation. We first present a review of mechanisms that may or may not affect the ultimate fields that can be obtained in rf cavities, assuming that mechanical stress explains the triggers of rf breakdown events. We present a method of quantifying the surface damage caused by breakdown events in terms of the spectrum of field enhancement factors, Beta, for asperities on the surface. We then model an equilibrium that can develop between damage and conditioning effects, and show how this equilibrium can determine cavity performance and show experimental evidence for this mechanism. We define three functions that quantify damage, and explain how the parameters that determine this performance can be factored out and measured. We then show how this model can quantitatively explain the dependence of cavity performance on material, frequency, ...

2006-04-14

206

Spectral Cross-calibration of the Konus-Wind, the Suzaku/WAM, and the Swift/BAT Data using Gamma-Ray Bursts  

CERN Document Server

We report on the spectral cross-calibration results of the Konus-Wind, the Suzaku/WAM, and the Swift/BAT instruments using simultaneously observed gamma-ray bursts (GRBs). This is the first attempt to use simultaneously observed GRBs as a spectral calibration source to understand systematic problems among the instruments. Based on these joint spectral fits, we find that 1) although a constant factor (a normalization factor) agrees within 20% among the instruments, the BAT constant factor shows a systematically smaller value by 10-20% compared to that of Konus-Wind, 2) there is a systematic trend that the low-energy photon index becomes steeper by 0.1-0.2 and Epeak becomes systematically higher by 10-20% when including the BAT data in the joint fits, and 3) the high-energy photon index agrees within 0.2 among the instruments. Our results show that cross-calibration based on joint spectral analysis is an important step to ...

2010-01-01

207

Plant protection i willow plantations - Insects. Final report; Vaextskydd i Salixodlingar - Insekter. Slutrapport  

Energy Technology Data Exchange (ETDEWEB)

Attacks by herbivorous insects reduce biomass production in willow plantations. The long-term goal of our research is to develop sustainable plant protection against these insect pests. Two lines of research are pursued. The first concentrates on identifying factors involved in the regulation of leaf-eating beetles. These insects vary in density among plantations, sometimes reaching outbreak levels resulting in complete defoliation. Mortality factors of eggs and larvae in plantations with low and high beetle densities have been investigated. The importance of plant resistance has also been investigated. The second line of research considers the mechanisms behind an earlier demonstrated resistance in certain willow clones against a gall midge. By using molecular techniques we have searched for markers of resistance. Promising results have been found concerning so called PR proteins; in particular chitinase seems to be present in high activities ...

2000-04-01

208

An investigation of the factors controlling the pyrolysis product yield of Greek wood biomass in a fluidized bed  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of Greek fir wood samples in a fluidized bed reactor was studied. The experimental conditions selected control the yield of gaseous, liquid and solid products. The factors examined were: pyrolysis temperature, mean particle size, pressure, residence time of volatiles, lignin content of biomass and moisture content. The experiments were performed on the basis of a 12-run Plackett-Burman fractional factorial design. Statistical analysis of the data showed that the pyrolysis temperature is the main factor affecting the distribution of the yields of liquids, their phenolic fraction and gases in the range of experimental conditions tested. Empirical expressions were obtained from linear regression giving the yields of liquids, phenols and gases in terms of temperature. The maximum predicted yields were 56 and 12 wt.% on a moisture-free basis at 520 C and 545 C for liquids and phenols, respectively. The yield of gases ...

1990-11-01

209

Accelerated aging tests with a resid hydrotreating catalyst  

Energy Technology Data Exchange (ETDEWEB)

The deactivation rate of a resid hydrotreating catalyst is determined by a complex set of factors involving both chemical and physical changes in the catalyst structure. The various chemical changes that are associated with resid conversion involve thermal and catalytic steps of relatively large molecular weight species with the overall rates significantly affected by mass transfer limitations. The deposition of coke and the variation in the effective promoter level by the accumulation of metals deposited from the resid are the principal factors governing deactivation. The relative importance of mass transfer restrictions on activity and catalyst deactivation can be observed in studies where the average pore diameter of the catalyst has been varied. Several models have been proposed to characterize the deactivation of resid hydroprocessing catalysts. In this paper, the authors discuss some accelerated aging tests with a ...

1987-04-01

210

Influence of two changes in the composition of an acrylic bone cement on its handling, thermal, physical, and mechanical properties.  

Science.gov (United States)

This study is a contribution to the growing body of work on the influence of changes in the composition of an acrylic bone cement on various properties of the curing and cured material. The focus is on one commercially-available acrylic bone cement brand, Surgical Simplex P, and three variants of it and a series of properties, namely, setting time, maximum exotherm temperature, activation energy and frequency factor for the polymerization reaction, diffusion coefficient for the uptake of phosphate buffered saline, at 37 degrees C, ultimate compressive strength (UCS), plane-strain fracture toughness, fatigue life (under fully-reversed tension-compression stress), hardness (H) and elastic modulus (both determined using quasi-static nanoindentation), and the variation of the storage and loss moduli with frequency of the applied force in a dynamic nanoindentation test. It was found that (a) a 68% reduction in the volume of the activator, N,N ...

2007-05-05

211

An overview of the development of the first wall and other principal components of a laser fusion power plant  

International Nuclear Information System (INIS)

This paper introduces the JNM Special Issue on the development of a first wall for the reaction chamber in a laser fusion power plant. In this approach to fusion energy a spherical target is injected into a large chamber and heated to fusion burn by an array of lasers. The target emissions are absorbed by the wall and encapsulating blanket, and the resulting heat converted into electricity. The bulk of the energy deposited in the first wall is in the form of X-rays (1.0-100 keV) and ions (0.1-4 MeV). In order to have a practical power plant, the first wall must be resistant to these emissions and suffer virtually no erosion on each shot. A wall candidate based on tungsten armor bonded to a low activation ferritic steel substrate has been chosen as the initial system to be studied. The choice was based on the vast experience with these materials in a nuclear environment and the ability to address most of the key remaining issues with existing facilities. This overview paper is divided ...

2005-12-15

212

The Results of Curative Concurrent Chemoradiotherapy for Anal Carcinoma  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the predictive factors for treatment response and prognostic factors affecting survival outcomes after concurrent chemoradiotherapy (CCRT) for patients with anal squamous cell carcinoma. Medical records of forty two patients with histologically confirmed analsquamous cell carcinoma, who had complete CCRT between 1993 and 2008, were reviewed retrospectively. Median age was 61.5 years (39-89 years), and median radiotherapy (RT) dose was 50.4 Gy (30.0-64.0 Gy). A total of 36 patients had equal to or less than T2 stage (85.7%). Fourteen patients (33.3%) showed regional nodal metastasis, 36 patients (85.7%) were treated with 5-fluorouracil (5-FU) plus mitomycin, and the remaining patients were treated by 5-FU plus cisplatinum. The median follow--up time was 62 months (2-202 months).The 5-year overall survival, locoregional relapse-free survival, disease-free survival, and colostomy-free survival rates were 86.0%, ...

2010-11-15

213

Ionization-chamber-dependent factors for calibration of megavoltage X-ray and electron beam therapy machines  

International Nuclear Information System (INIS)

When exposure-calibrated ionization chambers are used to calibrate megavoltage X-ray and electron beam therapy machines, the calibration factor can be divided into a chamber-dependent and a chamber-independent component. Until recently, only the chamber-independent part, which has been derived theoretically, has been used; the chamber-dependent component has been ignored. Recent experimental and theoretical considerations, however, have indicated that the dependent component must be taken into account and can affect the calibration by as much as 4%. The calibration can change due to (i) the thickness of the chamber wall, (ii) the chamber wall composition, i.e. whether the chamber is constructed of air-equivalent material, or tissue- or water-equivalent material, and (iii) the size of the chamber changing the displacement factor. Theoretical and experimental evidence indicates that the third factor ...

214

Development of low-level liquid-waste treatment systems: April-September 1982  

Energy Technology Data Exchange (ETDEWEB)

A preliminary investigation was conducted on ion specific membranes. This investigation concentrated on testing candidate organic compounds for transporting cesium ions through a membrane composed of the organic compound supported on a substrate. Solid PVC membranes were initially tried, but were found to be too slow. Thereafter, only liquid membranes were tested. These were faster and cesium concentration factors up to 2.96 were achieved in a single membrane cell. A cell with two membranes achieved a cesium concentration factor of 4.19. Cesium precipitation with sodium tetraphenyl borate in high sodium concentrations was explored. No interference from sodium was found until the sodium nitrite concentration reached 4.5 moles. Concurrently, cesium concentrations as high as 5.4 g/L were precipitated. Potassium tetraphenyl borate is being investigated for use in exchange columns for the removal of cesium from solutions. Initial investigations show ...

1982-12-22

215

Development of low-level liquid-waste treatment systems: April-September 1982  

International Nuclear Information System (INIS)

A preliminary investigation was conducted on ion specific membranes. This investigation concentrated on testing candidate organic compounds for transporting cesium ions through a membrane composed of the organic compound supported on a substrate. Solid PVC membranes were initially tried, but were found to be too slow. Thereafter, only liquid membranes were tested. These were faster and cesium concentration factors up to 2.96 were achieved in a single membrane cell. A cell with two membranes achieved a cesium concentration factor of 4.19. Cesium precipitation with sodium tetraphenyl borate in high sodium concentrations was explored. No interference from sodium was found until the sodium nitrite concentration reached 4.5 moles. Concurrently, cesium concentrations as high as 5.4 g/L were precipitated. Potassium tetraphenyl borate is being investigated for use in exchange columns for the removal of cesium from solutions. Initial investigations show ...

216

Strikingly different penetrance of LHON in two Chinese families with primary mutation G11778A is independent of mtDNA haplogroup background and secondary mutation G13708A  

Energy Technology Data Exchange (ETDEWEB)

The penetrance of Leber's hereditary optic neuropathy (LHON) in families with primary mitochondrial DNA (mtDNA) mutations is very complex. Matrilineal and nuclear genetic background, as well as environmental factors, have been reported to be involved in different affected pedigrees. Here we describe two large Chinese families that show a striking difference in the penetrance of LHON, in which 53.3% and 15.0% of members were affected (P < 0.02), respectively. Analysis of the complete mtDNA genome of the two families revealed the presence of the primary mutation G11778A and several other variants suggesting the same haplogroup status G2a. The family with higher penetrance contained a previously described secondary mutation G13708A, which presents a polymorphism in normal Chinese samples and does not affect in vivo mitochondrial oxidative metabolism as described in a previous study. ...

2008-08-25

217

Strikingly different penetrance of LHON in two Chinese families with primary mutation G11778A is independent of mtDNA haplogroup background and secondary mutation G13708A  

International Nuclear Information System (INIS)

The penetrance of Leber's hereditary optic neuropathy (LHON) in families with primary mitochondrial DNA (mtDNA) mutations is very complex. Matrilineal and nuclear genetic background, as well as environmental factors, have been reported to be involved in different affected pedigrees. Here we describe two large Chinese families that show a striking difference in the penetrance of LHON, in which 53.3% and 15.0% of members were affected (P < 0.02), respectively. Analysis of the complete mtDNA genome of the two families revealed the presence of the primary mutation G11778A and several other variants suggesting the same haplogroup status G2a. The family with higher penetrance contained a previously described secondary mutation G13708A, which presents a polymorphism in normal Chinese samples and does not affect in vivo mitochondrial oxidative metabolism as described in a previous study. Evolutionary ...

2008-08-25

218

Ecological risk assessment of the east branch, Finniss River  

International Nuclear Information System (INIS)

Quantitative ecological risk assessment (ERA) is a means whereby the risk posed by a toxicant in any system can be evaluated by comparing the distribution of its measured or modelled concentrations (water quality data (WQD)) with available information on the range of concentrations that are known to adversely affect biota within that, or similar, habitats (dose-response data (DRD)). Initially, the WQD are compared with regulatory criteria (e.g. ANZECC and ARMCANZ, 2000). If they fail this test, then, on the assumption that both data sets comprise subsets of the entire range of concentrations, probability density functions are derived assuming a standard distribution form a typically log-normal. In this paper, AQUARISK has been used to estimate the risk posed by copper in effluent from the Rum Jungle mine site, pre- and post-remediation, and the proportion of taxa likely to be affected in the East Branch (EB) of the Finniss River downstream of ...

2002-03-01

219

Mechanical properties and structure of low-alloy ultra-high strength steels  

Energy Technology Data Exchange (ETDEWEB)

Mechanical properties of P-LDHA and V-ROL N steels of the Czech production are compared with other ultra-high strength steels produced in the world. The most important results can be summarized into following points: 1. Optimally heat treated P-LDHA steel exhibits substantially better strength characteristics then the V-ROL N steel. 2. Optimal tempering temperature of the P-LDHA steel is 300 C. 3. Basic mechanical properties of P-LDHA steel belong to the top of the UHS steels ranking and are well comparable with those of American 300 M steel. 4. In the low-cycle fatigue region, the P-LDHA steel exhibits slightly better fatigue resistance then the 300 M steel. On the other hand, the high-cycle fatigue resistance of 300 M steel is slightly better then that of the P-LDHA steel. (orig.)

2000-07-01

220

Low-cycle fatigue behaviour and microstructure of copper and alpha-brass under biaxial load paths  

Energy Technology Data Exchange (ETDEWEB)

The low-cycle fatigue behaviour of copper and a-brass CuZn30 was investigated in uniaxial and biaxial tests. Planar biaxial fatigue tests were carried out using cruciform samples with proportional stain paths with and without phase shift between the two axes. Microcharacterisation was performed by electron microscopy as well as by high-resolution X-ray line profile analysis. The biaxial cyclic stress-strain curves show good agreement with the uniaxial ones using the von Mises equivalent strain hypothesis. The dislocation densities and microhardness values of the biaxial case, however, show significantly lower values compared to the uniaxial case at equivalent von Mises stresses.

2010-07-01

221

High-temperature low-cycle fatigue and tensile properties of Hastelloy X and alloy 617 in air and HTGR-helium  

Energy Technology Data Exchange (ETDEWEB)

Results of strain controlled fatigue and tensile tests are presented for two nickel base solution hardened alloys which are reference structural alloys for use in several high temperature gas cooled reactor concepts. These alloys, Hastelloy X Inconel 617, were tested at temperatures ranging from room temperature to 871/sup 0/C in air and impure helium. Materials were tested in the solution annealed as well as in the pre-aged condition where aging consisted of isothermal exposure at one of several temperatures for periods of up to 20,000 h. Comparisons are also given between the strain controlled fatigue lives of these alloys and several other commonly used alloys all tested at 538/sup 0/C.

1981-01-01

222

Fracture mechanics: proceedings of the 12th national symposium on fracture mechanics  

Energy Technology Data Exchange (ETDEWEB)

The conference proceedings contains 30 papers of which five are abstracted separately. The subjects covered include fatigue crack growth in aircraft materials, fractographic measurements, fatigue cracks in nylon 66 blends, cyclic inelastic deformation aspects, prestressing, tensile cracks in creeping solids, creep-crack-growth in 304 stainless steel, high-temperature fatigue, parallel impact loading, numerical fracture dynamic code, J-resistance curves, specimen geometry effects, reactor piping systems, temperature dependence of fracture toughness, small-scale yielding, compact specimens, power hardening materials, semi-empirical fracture analyses, pipeline girth welds, wrought steels, and A36 bridge steels.

1980-01-01

223

Development of SDT sensor based eddy current probe for detection of deep fatigue cracks in multi-layer structure  

British Library Electronic Table of Contents (United Kingdom)

The detection and characterization of deeply buried fatigue damage in thick, multi-layer airframe components pose significant technical challenges to the aviation safety community. Currently, no nondestructive evaluation technique is available to reliably detect such potential damage from the exterior of the airframe, which is highly desirable in light of inspection cost as well as avoidance of structure damage. Recent technological advances in high-sensitivity magnetic sensors, i.e., spin-dependent tunneling (SDT) sensors, make it feasible to employ electromagnetic inspection techniques for deep fatigue crack inspection. In this work, we report on the development and fabrication of a low frequency eddy current probe based on a magnetically shielded SDT pickup sensor concentrically located...

2010-01-01

224

Analysis of deteriorating processes in primary circuit facilities and determination of their priorities and relevance to the lifetime of the main primary circuit components  

International Nuclear Information System (INIS)

The major degradation mechanisms acting during the aging of selected WWER-440/213 primary circuit facilities were assessed critically. The analysis gave evidence that such mechanisms include radiation and fatigue damage of the reactor pressure vessel (effect of the neutron flow, cyclic fatigue promoted by the corrosive medium, effect of thermal aging), corrosion-mechanical and thermo-mechanical (fatigue) damage of the steam generator (stress corrosion cracking, erosion corrosion, thermal aging, wear), thermal and dynamic aging of the pressurizer, and corrosion-mechanical damage of the primary circuit piping (thermal aging, corrosion). (J.B.). 5 tabs., 1 fig., 62 refs.

225

Public perceptions of wind energy developments: Case studies from New Zealand  

Energy Technology Data Exchange (ETDEWEB)

Although the public generally hold positive attitudes towards wind energy, proposals for the construction of new wind farms are often met with strong resistance. In New Zealand, where the government has recently introduced ambitious policy targets for renewable energy generation, negative perceptions of wind farms are increasingly evident and have the potential to prevent the achievement of these targets. This research sets out to examine what influences social resistance to wind farms in New Zealand. Drawing from public submissions on three wind farm proposals, a framework developed by Devine-Wright [Devine-Wright, P., 2005a. Beyond NIMBYism: towards an integrated Framework for Understanding Public Perceptions of Wind Energy. Wind Energy 8, 125-139.] was used as the basis for identification of factors affecting public perceptions of wind farms. The research found firstly that there was no apparent relationship between the proximity of ...

2009-09-15

226

Public perceptions of wind energy developments. Case studies from New Zealand  

Energy Technology Data Exchange (ETDEWEB)

Although the public generally hold positive attitudes towards wind energy, proposals for the construction of new wind farms are often met with strong resistance. In New Zealand, where the government has recently introduced ambitious policy targets for renewable energy generation, negative perceptions of wind farms are increasingly evident and have the potential to prevent the achievement of these targets. This research sets out to examine what influences social resistance to wind farms in New Zealand. Drawing from public submissions on three wind farm proposals, a framework developed by Devine-Wright [Devine-Wright, P., 2005a. Beyond NIMBYism: towards an integrated Framework for Understanding Public Perceptions of Wind Energy. Wind Energy 8, 125-139.] was used as the basis for identification of factors affecting public perceptions of wind farms. The research found firstly that there was no apparent relationship between the proximity of ...

2009-09-15

227

Experimental parameters differentially affect the humoral response of the cholera-toxin-based murine model of food allergy  

DEFF Research Database (Denmark)

Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle immunomodulating factors or factors effective during response initiation, this maximal response-based model is less suitable due to a lack of sensitivity. Therefore, in attempts to identify essential parameters to fine-tune the immune response towards a submaximal level, potentially more sensitive, we were interested in characterizing the individual effects of the parameters in the CT-based model: CT dose, antigen type and dose, and number of immunizations. Methods: BALB/c mice were orally sensitized weekly for 3 or 7 weeks with graded doses of CT and various food antigens (soy-trypsin inhibitor, ovalbumin or ovomucoid). Antigen-specific lgG1, IgG2a, IgA and IgE ...

2003-01-01

228

Water Repellency Microstructure Oligomer Formulation Cured with Electron Beam  

International Nuclear Information System (INIS)

Water repellency en the microstructure super-hydrophobic cured surface is important for research and industrial purposes. This microstructure film can be cured on polyethylene terephthalate PET surface by electron beam (EB) at different irradiation doses 10-100 kGy. The microstructure formulation composed from hydrophobic acrylate oligomer (EB 244) and monomer (SR 440). The irradiation induced cross linking of the prepared microstructure was proved by FTIR spectroscopy and the adhesion force by abrasion test. Some factors affecting the adhesion force of the prepared microstructure film such as oligomer/monomer composition ratio and the thickness of the microstructure cured film were studied. The contact angles (8) were measured on cured surfaces before and after adding the super hydrophobic nanoparticles (Zonyl 9361). The super-hydrophobic cured surface showed the self-cleaning property. The volume of water droplet affected ...

229

Space effect on liquid film flow in a BWR fuel bundle  

Science.gov (United States)

Critical power at boiling transition is an important factor in a boiling water reactor (BWR) fuel bundle design. Boiling transition under high quality accounts for dryout as the result of the complete disappearance of film flow on a fuel rod. This liquid film vanishing process can be calculated by the liquid film model, which takes into account the evaporation due to heat from the rod surface, liquid film entrainment by steam flow, and liquid droplet deposition. It is known that spacers affect liquid film entrainment and liquid droplet deposition, so the detailed study of spacer effects on hydrodynamic characteristics is necessary for critical power prediction based on the film flow model. Many studies have been conducted to examine spacer effects on liquid film flow. However, most of them are restricted to simple test sections such as a rectangular conduit. There are a few reports on fuel bundle geometry; however the bundle studied was only a ...

1991-01-01

230

Neutrino emission in neutron matter from magnetic moment interactions  

CERN Document Server

Neutrino emission drives neutron star cooling for the first several hundreds of years after its birth. Given the low energy ($\\sim$ keV) nature of this process, one expects very few nonstandard particle physics contributions which could affect this rate. Requiring that any new physics contributions involve light degrees of freedom, one of the likely candidates which can affect the cooling process would be a nonzero magnetic moment for the neutrino. To illustrate, we compute the emission rate for neutrino pair bremsstrahlung in neutron-neutron scattering through photon-neutrino magnetic moment coupling. We also present analogous differential rates for neutrino scattering off nucleons and electrons that determine neutrino opacities in supernovae. Employing current upper bounds from collider experiments on the tau magnetic moment, we find that the neutrino emission rate can exceed the rate through neutral current electroweak interaction by a ...

2004-01-01

231

Mechanisms of ozone tolerance in rice: characterization of two QTLs affecting leaf bronzing by gene expression profiling and biochemical analyses  

British Library Electronic Table of Contents (United Kingdom)

High surface ozone concentration is increasingly being recognized as a factor that negatively affects crop yields in Asia. However, little progress has been made in developing ozone-tolerant genotypes of rice-Asias major staple crop. This study aimed to identify possible tolerance mechanisms by characterizing two quantitative trait loci (QTLs) that were previously shown to influence visible leaf symptoms under ozone exposure (120 nl l-1, 7 h d-1, 13 d). Two chromosome segment substitution lines (SL15 and SL41) that carried introgressions of the QTLs OzT3 and OzT9, respectively, were exposed to ozone at 120 nl l-1 along with their parent Nipponbare. In accordance with the expected QTL effect, SL15 showed stronger visible symptoms of ozone damage than Nipponbare, whereas SL41 had fewer sympt...

2010-01-01

232

Graphite Technology Development Plan  

Energy Technology Data Exchange (ETDEWEB)

This technology development plan is designed to provide a clear understanding of the research and development direction necessary for the qualification of nuclear grade graphite for use within the Next Generation Nuclear Plant (NGNP) reactor. The NGNP will be a helium gas cooled Very High Temperature Reactor (VHTR) with a large graphite core. Graphite physically contains the fuel and comprises the majority of the core volume. Considerable effort will be required to ensure that the graphite performance is not compromised during operation. Based upon the perceived requirements the major data needs are outlined and justified from the perspective of reactor design, reatcor performance, or the reactor safety case. The path forward for technology development can then be easily determined for each data need. How the data will be obtained and the inter-relationships between the experimental and modeling activities will define the technology development for graphite R&D. Finally, the ...

2007-09-01

233

Effect of powder characteristics on oral tablet disintegration.  

Science.gov (United States)

This report describes an investigation of the factors affecting disintegration time in the mouth (DTM) of rapidly disintegrating tablets. The relation between DTM and stationary time of upper punch displacement (STP) was examined using a tableting process analyzer (TabAll). Results indicated that the bulk density of mixed excipient powder used for tablet preparation affects both DTM and STP. As the value of bulk density increased, STP became longer and DTM shorter. The results of a combination of granules and powder with or without a drug showed liner relation between apparent volume (reciprocal of bulk density) and DTM (r(2)=0.7332). For a DTM less than 60 s, a formulation with a bulk density greater 0.5 g/mL should be chosen with a compression force of 5 kN. The hardness of tablets could be greater than 3 kg if at least one high-compressibility excipient was used in the formulation. PMID:18804156

2008-08-29

234

Distinct spatial characteristics of industrial and public research collaborations: Evidence from the 5th EU Framework Programme  

CERN Document Server

This study compares the spatial characteristics of industrial R&D networks to those of public research R&D networks (i.e. universities and research organisations). The objective is to measure the impact of geographical separation effects on the constitution of cross-region R&D collaborations for both types of collaboration. We use data on joint research projects funded by the 5th European Framework Programme (FP) to proxy cross-region collaborative activities. The study area is composed of 255 NUTS-2 regions that cover the EU-25 member states (excluding Malta and Cyprus) as well as Norway and Switzerland. We adopt spatial interaction models to analyse how the variation of cross-region industry and public research networks is affected by geography. The results of the spatial analysis provide evidence that geographical factors significantly affect patterns of industrial R&D collaboration, while in the public ...

2010-01-01

235

Development of advanced residential cooktop burner with low NOx emissions. Annual report on phase 1, Feb 82-Oct 83  

Science.gov (United States)

This report describes the result of work completed during February, 1982 to October 1983. The aim of the work was to develop a low NO(x) emission range top burner. Discussed is the development of a flame insert modification to an existing burner which reduces NO(x) emission by 45 percent and NO2 emission by 25 percent. This relatively simple burner add-on device appears to be an economically viable low NO(x) burner. It was developed in cooperation with a major range manufacturer. The levels of NO(x) (NO2) reduction achieved should significantly reduce the impact of a gas range to indoor quality. The report also discusses the results of a literature search that preceeded the burner development. The search helped to direct the burner development by reviewing the state-of-the-art of low NO(x) burner design and covered factors which affect the indoor impact of range emissions such as air infiltration and ventilation trends, air quality standards, ...

1983-11-01

236

A global geographic information system data base of storm occurrences and other climatic phenomena affecting coastal zones  

Energy Technology Data Exchange (ETDEWEB)

This document describes the contents of a digital climatological data set that may be used by raster or vector geographic information systems (GISs). The primary focus of the data set is the quantification of the occurrence of synoptic storms and other climatological factors that affect coastlines. However, recent demands for new and/or improved climatologies of storm events as well as an increase in the availability of source data have made it useful to extend the domain of most of the data variables to that of regional and/or global coverage. The expansion of the data makes the data set applicable in several areas of climatic research. The data set contains eight data groups. Spatial coverage of data varies by data group. All data groups except one are referred to 1{degree} {times} 1{degree} or 5{degree} {times} 5{degree} grid cells of latitude and longitude. (Data group (3) is referenced by state.) 19 refs., 12 figs., 26 tabs.

1991-05-01

237

Role of Calcitonin Gene-Related Peptide in Bone Repair after Cyclic Fatigue Loading  

UK PubMed Central (United Kingdom)

BackgroundCalcitonin gene related peptide (CGRP) is a neuropeptide that is abundant in the sensory neurons which innervate bone. The effects of CGRP on isolated bone cells have been...Full Text Available

238

Return of Postural Control to Baseline After Anaerobic and Aerobic Exercise Protocols  

UK PubMed Central (United Kingdom)

Context:With regard to sideline concussion testing, the effect of fatigue associated with different types of exercise on postural control is unknown.Objective:To...Full Text Available

2008-09-01

239

Probabillistic Sensitivity Analysis in Life-Prediction of an alpha + beta Titanium Alloy.  

Science.gov (United States)

Probabilistic sensitivities using the score function method are developed for a lifing analysis of an alpha + beta titanium alloy in a round bar under axial fatigue load. Sensitivities with respect to the statistical inputs of the crack initiation size (a...

2008-01-01

240

Plasma nitriding of austenitic stainless steel in N_2 and N_2/H_2 gas admixture  

International Nuclear Information System (INIS)

Plasma nitriding in glow discharge is a process of modifying surface properties of a material by which surface hardness, corrosion resistance, fatigue strength etc. of a material can be improved

2004-09-01

241

Origin of XMRV and its Demise as a Human Pathogen Associated with Chronic Fatigue Syndrome  

UK PubMed Central (United Kingdom)

Retroviruses are well known pathogens of mammals, birds and fish. Their potential to induce cancer in chickens was already described almost 100 years ago and murine retroviruses have been a subject...Full Text Available

242

Monotonic and Low-Cycle Fatigue Response of a Maraging Steel and Metastable Beta Titanium Alloy under Torsional Loading.  

Science.gov (United States)

This study deals with the torsional response of Ti-8823 and 18Ni (200) maraging steel. The effect of different heat treatments and the subsequent change in microstructure are investigated. In the case of the Ti-8823, a comparison was made between the solu...

1977-01-01

243

Large-Scale Advanced Propfan ... - NASA Technical Reports Server  

Science.gov (United States)

STRESS. VIBRATION DISTRIBUTION FATIGUE FOD. BLADE. X. X. X. X. HUB. X. X. X. SPINNER. X. X. X. Figure 21. - Large scale component test matrix. ...

244

Environmentally assisted cracking in light-water reactors: Semi-annual report, January--June 1997. Volume 24  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors from January 1997 to June 1997. Topics that have been investigated include (a) fatigue of carbon, low-alloy, and austenitic stainless steels (SSs) used in reactor piping and pressure vessels, (b) irradiation-assisted stress corrosion cracking of Types 304 and 304L SS, and (c) EAC of Alloys 600 and 690. Fatigue tests were conducted on ferritic and austenitic SSs in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during various portions of a tensile-loading cycle is equally effective in decreasing fatigue life. Slow-strain-rate-tensile tests were conducted in simulated boiling water reactor (BWR) water at 288 C on SS specimens irradiated to a low fluence in the Halden reactor and the results ...

1998-04-01

245

Effects of Manufacturing Defects and Scaling on Glass Fiber Composite Sandwich Panels in General Aviation Aircraft Structures.  

Science.gov (United States)

This report documents the collaborative effort between the United States and Canada to investigate the impact of process-induced defects on strength and stiffness under static and fatigue loading and for low-cost composite aircraft structures, in particul...

2009-01-01

246

Wear and machining of engineering ceramics by abrasive waterjets  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this investigation was to simulate a machining front from an abrasive waterjet and its movements in a ceramic material. Wear factors affecting the abrasive waterjet nozzle were also to be established. Therefore, a low inclination angle (9[degree]) was used between the nozzle and test sample, simulating a moving machine front. A standard nozzle with an inner diameter of 0.76 mm was used in the test, and it was placed close to the samples. The outer diameter of the abrasive nozzle was 9.5 mm. The high wear rate from abrasive waterjets makes it possible to machine hard ceramics-including dense alumina, titanium boride, silicon nitride, and composites-at high machining speeds.

1993-08-01

247

The diffusion bonding and theoretical model including void growth mechanism in magnesium alloys  

Energy Technology Data Exchange (ETDEWEB)

There are many factors affecting diffusion bonding in order to obtain high quality joining. Therefore, in the beginning, we constructed diffusion bonding model based on void growth mechanism to predict bonding pressures and times. In addition, in order to compare theoretical values with experimental values, diffusion bonding tests were carried out by using commercial AZ31 magnesium alloy sheets with different grain sizes, 16 and 130 {mu}m. The present AZ31 alloys were successfully diffusion bonded at several conditions, and the bonding strength was more than 0.8 of each parent materials. The experimental bonding conditions in high quality joining, times and pressures, were good agreed with prediction analysis. (orig.)

2003-07-01

248

Temporal variations of fluoride concentration in Isparta public water system and health impact assessment (SW-Turkey)  

British Library Electronic Table of Contents (United Kingdom)

Water?rock interaction is one of the prime factors affecting the fluoride contents of surface and groundwater. If fluoride concentration of drinking water has been neglected, excess fluoride can cause serious dental and medical problems on human health, which is well known at Golcuk-Isparta region. In the research area, Egirdir lake, Golcuk lake and surrounding springs have been utilized as drinking water sources. Golcuk lake water and surrounding groundwaters have high fluoride content (1.4?4.6?mg/l), which is above the WHO standards. Fluoride is predominantly supplied by dissolution of fluoride within the fluormicas of volcanics during the circulation of water. Fluoride concentrations of waters have shown variations for dry and rainy seasons depending on the degree of interaction between...

2008-01-01

249

Study of technetium chemistry. Pt.10: Qsar analysis of "9"9Tc"m-labelled N_2S_2 analogues of brain imaging agents  

International Nuclear Information System (INIS)

Quantitative structure activity relationship (QSAR) analysis of the correlations between initial brain uptake and structure parameters, for example lipophilicity F_r, molar refractivity MR and electronic parameters #sigma#_1 of the "9"9Tc"m-N_2S_2 complexes have been studied with multiple regression analysis method. The main structural factors which affect the initial brain uptake of this kind of brain imaging agents have been discussed. The results may give some theoretical information for designing new brain imaging agents

1998-02-01

250

Structural design at the polymer surface interface in nanoporous silica polyamine composites  

British Library Electronic Table of Contents (United Kingdom)

The factors affecting the rate of silica leaching in alkaline aqueous media from surface silanized, nanoporous, amorphous, silica gels and from silanized silica gels that have been modified with polyamines to form the previously reported silica polyamine composites (SPCs), BP-1 and BP-2 have been investigated. Silanization with alkyl trichlorosilanes slows the rate of silica leaching relative to the unmodified silica gels. The use of bulkier aryl silanes somewhat decreases the silica leaching under the same conditions. Interestingly, after modification of the silanized silica with poly(allylamine) (PAA) to make BP-1, the leaching increases, but subsequent modification of the SPC with chloroacetic acid to make BP-2, quenches this increase. A mechanism explaining these results is discussed. ...

2011-01-01

251

Smart pigs root out pipeline problems  

Energy Technology Data Exchange (ETDEWEB)

In the world of pipeline maintenance, there are pigs and there are intelligent pigs. Intelligent pigs, when launched into a pipeline, carry instrumentation onboard which enables them to gather and record information about problems such as denting, corrosion, and cracking. More basic pigs, on the other hand, look after the routine internal maintenance chores such as cleaning and swabbing, or else perform operational duties such as batching different types of product along the line. The harsh environment in which pigs often operate is described. Aside from the mechanical shocks they undergo when passing welds, bends, and other fittings, they may have to contend with hostile conditions such as hydrogen sulfide environments. High pressure is another factor to consider. In crude oil lines, significant paraffin deposits also can cause problems if they affect the sensors ability to maintain good contact with the pipe wall. In spite of these ...

1983-12-01

252

Serological Reactivity to Borrelia burgdorferi Sensu Lato in Dogs and Horses from Distinct Areas in Romania  

British Library Electronic Table of Contents (United Kingdom)

Abstract Lyme disease is a perfect model of the complex relationship between host, vector, and the vector-borne bacteria. Both dogs and horses in Romania are exposed to infection. The aim of the present study was to assess the seroreactivity against Borrelia burgdorferi sensu lato in dogs and horses from different regions of Romania. 276 samples from dogs and 260 samples from horses located in different regions of Romania were analyzed by ELISA and IFA, respectively. The effect of several factors potentially affecting seroreactivity (location, age, gender, occupation, and vector exposition risk) was evaluated using Fisher's exact test (R 2.12.0). The overall prevalence of anti-Borrelia antibodies was 6.52% (18/276) in dogs, with a significantly higher positivity (46.15%, 6/13, p=0.0005) re...

2011-01-01

253

Science at the Theater: Hot Technology, Cool Science  

ScienceCinema

...global warming um ? know he's been right into our our ...who was a little bit about global warming and cooling ...global warming ...america uh we can help ? global warming and reduce the demand for electricity and and ...now means that those who immediately combat global warming ? ...global warming ...global warming ...global warming by ...we ? in terms of the contribution to global warming is a small i mean anything else ...global warming and ...among scientists are speaking out about global warming the only thing they really talk about a year to ...the other factors that affect global warming and i i just feel that ...problem of global warming would have to ...global warming ...global warming ...

254

Restoring Jarrah Forest Trees after Bauxite Mining in Western Australia  

British Library Electronic Table of Contents (United Kingdom)

Abstract The overstory of the jarrah forest is dominated by Jarrah (Eucalyptus marginata) with a smaller proportion of Marri (Corymbia calophylla). There are also several smaller tree species in the areas where Alcoa mines. Alcoa's restoration aims to restore all these species at densities similar to the unmined forest. This paper describes the establishment, survival, and growth of these trees with particular focus on Jarrah. Factors affecting the growth and form of Jarrah are also discussed. Establishment of Jarrah from seed in restored sites is variable (mean 10%), and once established, survival is high over two summer droughts (96%) and still high (mean 83%) after about a decade regardless of the presence of the Jarrah dieback disease Phytophthora cinnamomi. High establishment densitie...

2007-01-01

255

Relationships between number and space processing in adults with and without dyscalculia  

British Library Electronic Table of Contents (United Kingdom)

A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding atypical math development. Adults with a diagnosis of dyscalculia (DYS) during childhood were compared to adults with average or high abilities in mathematics across two bisection tasks. Participants were presented with Arabic number triplets and had to judge either the number magnitude or the spatial location of the middle number relative to the two outer numbers. For the numerical judgment, adults with DYS were slower than both groups of control peers. They were also more strongly affected by the factors related to number magnitude such as the range of the triplets or the distance between t...

2011-01-01

256

Radon measurements at the FEMP  

Energy Technology Data Exchange (ETDEWEB)

Environmental radon monitoring activities at the DOE Fernald Environmental Management Project (FEMP) have been conducted extensively since the early 1980`s. Monitoring has been conducted at ambient concentration levels (< 1 pCi/L Rn-222), inside buildings, and at significantly elevated levels (hundreds of thousands pCi/L Rn-222) within the K-65 silo that store concentrated radium bearing wastes. The purpose of this paper/presentation is to present and discuss some of the difficulties encountered/solutions (e.g. reliability, detection limits, affects of environmental factors, data transfer, etc.) that have been discovered while taking measurements using both alpha track-etch passive integrating detectors and alpha scintillation real-time detectors. A short summary and conclusion section is provided following each topic presented.

1993-08-01

257

Prospective assessment of body weight and body composition changes in patients with psoriasis receiving anti-TNF- treatment  

British Library Electronic Table of Contents (United Kingdom)

Abstract Tumor necrosis factor (TNF)- is a pro-inflammatory cytokine associated with psoriasis pathogenesis. Anti-TNF- therapies are effective in psoriasis. A significant weight gain has been reported in patients treated with anti-TNF- agents. The aim of the present study was to evaluate the body composition changes in psoriatic patients receiving anti-TNF- therapies according with disease phenotype. Forty patients affected with psoriasis were followed up for 24 weeks and divided into two groups: psoriasis vulgaris (PsO) and psoriatic arthritis (PsA). Anthropometric, blood biochemical, body composition parameters, resting metabolic rate, and disease activity indexes were measured at baseline and at week 24. After 24 weeks of anti-TNF- administration, the disease activity indexes and concen...

2011-01-01

258

Production of carrier free 188Re radioisotope generator based on aluminum tungstate matrix  

British Library Electronic Table of Contents (United Kingdom)

Improved radionuclide generator include a substantially insoluble salt of a radioactive parent which may be directly packed in column for subsequent elution of the daughter radionuclide. An improved 188Re generator was prepared by reacting a radioactive tungsten (188W) as parent radionuclide incorporated with aluminum chloride to obtain an insoluble radioactive aluminum tungstate matrix. The investigated matrix was characterized on the basis of the chemical composition, IR, thermal analysis and mechanical stabilities. The factors affecting the elution performance were studied such as influence of pH, molar ratio and drying temperature. From the obtained data, the molar ratio W:Al was 1.5:1 at pH?=?4, the matrix dried at 105??C for 2 h. Chromatographic and multichannel analysis has been cur...

2010-01-01

259

Problem of blast furnace coke quality  

Science.gov (United States)

A brief discussion on the effects of moisture on the quality of metallurgical coke was presented. Factors affecting the moisture content of coke were discussed. The adsorption of moisture by coke at 20/sup 0/C and 120-130/sup 0/C and the desorption of moisture from coke at 200/sup 0/C were investigated with respect to dynamics. It was concluded that the moisture content of coke should not be used as a rejection index, but should be used for computations by the user. Also, it was determined that work should continue to achieve a coke moisture range of 4-6%. The desorption of moisture from coke is an order of magnitude greater at 200/sup 0/C than at 20/sup 0/C, and increases with temperature.

1982-01-01

260

Preparation and Characterization of a Novel Polyamide Charged Mosaic Membrane  

British Library Electronic Table of Contents (United Kingdom)

A novel composite charged mosaic membrane (CCMM) was prepared via interfacial polymerization (IP) of polyamine [poly(epichlorohydrin amine)] and trimesoyl chloride (TMC) on the polyethersulfone (PES) support. Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and water contact angle analysis were applied to characterize the resulted CCMM. The FT-IR spectrum indicates that TMC reacts sufficiently with polyamine. ESEM and AFM pictures show that the IP process produces a dense selective layer on the support membrane. The water contact angle of the CCMM is smaller than that of the substrate membrane because of the cross-linked hydrophilic polyamine network. Several factors affecting the IP reaction and the performan...

2010-01-01

261

Predicting urban forest growth and its impact on residential landscape water demand in a semiarid urban environment  

British Library Electronic Table of Contents (United Kingdom)

We present an innovative approach to estimating residential irrigation water demand for a large metropolitan area using GIS data, weather station data, and a water budget modeling approach commonly used by plant scientists and landscape management professionals. An important question addressed by our study is how a growing urban forest affects the overall irrigation water demand of a semiarid metropolitan area. To estimate the amount of water required by residential landscaping, we consider water demand to be a function of the areal extent of residential landscaping (i.e. tree/shrub or turf grass), the water-loss rate for different landscaping types, the efficiency with which the landscape is irrigated, and local climatic factors (i.e. reference evapotranspiration and precipitation). We es...

2011-01-01

262

Perception of anesthesia safety and postoperative symptoms of surgery patients in Ho Chi Minh City, Vietnam: a pioneering trial of postoperative care assessment in a developing nation  

British Library Electronic Table of Contents (United Kingdom)

Objectives Vietnamese patients? views on healthcare are changing as surgical interventions become more commonplace, but their views on perioperative care have remained largely unstudied during this period of rapid change. This study assesses Vietnamese patients? impression of anesthesia safety and postoperative pain in relation to clinical outcomes with the aim of improving patient-centered perioperative care. Methods The study cohort consisted of 180 hospitalized patients who were followed for 24?h following abdominal surgery. The assessments of these patients on the use of anesthesia and postoperative pain were measured by means of a 5-point Likert scale survey. Perioperative events were recorded on standardized forms by medical staff. The relationship between relevant factors affecting ...

2010-01-01

263

Ozone risk for crops and pastures in present and future climates  

British Library Electronic Table of Contents (United Kingdom)

Ozone is the most important regional-scale air pollutant causing risks for vegetation and human health in many parts of the world. Ozone impacts on yield and quality of crops and pastures depend on precursor emissions, atmospheric transport and leaf uptake and on the plant?s biochemical defence capacity, all of which are influenced by changing climatic conditions, increasing atmospheric CO2 and altered emission patterns. In this article, recent findings about ozone effects under current conditions and trends in regional ozone levels and in climatic factors affecting the plant?s sensitivity to ozone are reviewed in order to assess implications of these developments for future regional ozone risks. Based on pessimistic IPCC emission scenarios for many cropland regions elevated mean ozone lev...

2009-01-01

264

Optimization of extraction of high-ester pectin from passion fruit peel (Passiflora edulis flavicarpa) with citric acid by using response surface methodology  

British Library Electronic Table of Contents (United Kingdom)

A central composite design was employed to optimize the extraction of pectin with citric acid. The independent variables were citric acid concentration (0.086-2.91% w/v) and extraction time (17-102min). The combined effect of these variables on the degree of esterification was investigated. Results have shown that the generated regression models adequately explained the data variation and significantly represented the actual relationship between the independent variables and the responses. Besides that, the citric acid concentration was the most important factor to affect the degree of esterification, as it exerted a significant influence on the dependent variable. Lower citric acid concentration increased the pectin degree of esterification. The surface response showed the relationships b...

2008-01-01

265

On the problem of magnitude calibration of palaeoearthquakes  

British Library Electronic Table of Contents (United Kingdom)

Some factors affecting the accuracy of magnitude calibration of palaeoearthquakes are discussed. The general problem is illustrated by two case studies. First, the 2003 strong earthquake in the Altai region (Russia-Mongolia border), which has generated co-seismic surface faulting is considered. An analysis is conducted to determine how accurately its magnitude could be defined after 2000 years based on surface faulting parameters, retrieved when future palaeoearthquake studies are launched. This example demonstrates that accurate evaluation of magnitude is possible if specific regional seismotectonic features are taken into account and surface faulting parameters are measured over a dense grid. Next, the Muya earthquake that occurred in the Baikal seismic region in 1957 is studied with res...

2011-01-01

266

Nylon 66/polyester hybrid cords: 1. Design and investigation of properties  

British Library Electronic Table of Contents (United Kingdom)

In this study, Nylon 66/Polyester (Ny 66/PET) hybrid cord design and production was investigated to obtain new cord with better performance than conventional cord. The factors affecting cord properties and cord production process were examined. Taguchi design of experiment method was implemented in order to minimize the required number of experiments. Different sets of 4 reference cords conventionally used in tyre industry were prepared and resorcinol-formaldehyde-latex (RFL) treated in order to make a comparison of performance. Mechanical and thermal properties of hybrid cords were measured and compared with the values of reference cords. It was found that the twist level of high modulus PET component in the hybrid cords should be the same or above of the nylon in order to obtain maximum ...

2011-01-01

267

NEW SLAG-BASED CONCRETES  

Environmental Research Database

ObjectivesTo determine the reaction rate of slag during curing and factors affecting reactivity.~%~~%~To measure the rates of chloride ingress into concrete and the extent of chloride binding.~%~~%~To determine conditions for pitting corrosion and the nature of corrosion products.~%~~%~To characterise the reactions in slag-calcium alumina cement hydration and the nature of the products.~%~DescriptionBlast-furnace slag has latent hydraulic properties, giving considerable potential for commercial use in addition to its widespread use as a partial replacement for Portland cement, notably in alkali-activated slag (AAS) and slag-calcium alumina cement (CAC) concretes. Use of AAS concretes is already well-established in China and the former USSR, but their further application is hindered by lack of research into setting, hydration and durability, Slag/CAC blends are new materials whose chemistr ...

1999-01-09

268

Modeling of drug release from bulk-degrading polymers  

British Library Electronic Table of Contents (United Kingdom)

This paper aims to provide a comprehensive review of the various models or simulations for predicting drug release from bulk-degrading systems. A brief description of bulk degradation processes and factors affecting the degradation rate, and consequently the release kinetics, is presented first. Next, several important classical models, often used as the basis for subsequent model development, are discussed. Both mathematical models and Monte-Carlo based simulations have been developed for controlled release from bulk-degrading systems. The mathematical models can be further subdivided into two categories. First, the diffusion-based models whose transport mechanism is mainly governed by diffusion, but with degradation-dependent diffusion coefficients. These are generally simpler and easier...

2011-01-01

269

Minimizing radiation dose to patient and staff during fluoroscopic, nasoenteral tube insertions  

Energy Technology Data Exchange (ETDEWEB)

Since the fluoroscopic image during nasoenteral tube placements is used for guidance and not for diagnosis, a lower contrast image with increased quantum mottle can be easily tolerated. The three methods to reduce the radiation dose rate investigated consisted of removing camera from the image intensifier output phosphor, and setting the fluoroscopic mA to the minimum value so that the kVp could be maximized. Fluoroscopic frozen video frames of a clinical tube insertion comparing the images with and without the dose-saving techniques are presented. Measurements of the radiation dose rates using a Plexiglas phantom show that the dose for patient and staff during fluoroscopic-guided nasoenteral tube placements can be reduced by over a factor of 10 without significantly adversely affecting the actual placement procedure. (author).

1992-02-01

270

Mineral-wool industry: opportunities for natural gas technologies. Topical report, January-July 1987  

Science.gov (United States)

To quantify the opportunities for natural gas and identify technological advances needed to capture such opportunities, the mineral-wool industry was analyzed with respect to the principal companies, their capabilities, and markets. The mineral-wool industry is stable with a slightly declining market. Of its market segments, only commercial acoustic insulation (which is currently dominant) is likely to be affected by growth in the next ten years. The principal process is based on treatment of blast-furnace slags in a cupola furnace using coke as the fuel and reducing agent. Expanded use of gas, as a substitute for coke, would eliminate environmental problems and expand the latitude of suitable raw materials. The study provides insights into the mineral-wool industry and identifies factors that may constitute bases for future usage of natural gas.

1988-05-01

271

Microstructural characteristics and creep rupture behavior of electron beam and laser welded AISI 316L stainless steel  

Energy Technology Data Exchange (ETDEWEB)

AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ``parting`` region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ``parting`` region of the welds. (orig.).

1995-12-01

272

Microstructural characteristics and creep rupture behavior of electron beam and laser welded AISI 316L stainless steel  

International Nuclear Information System (INIS)

AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ''parting'' region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ''parting'' region of the welds. (orig.).

273

Mechanical properties of single- and double-gated injection moulded short glass fibre reinforced PBT/PC composites  

British Library Electronic Table of Contents (United Kingdom)

Tensile and flexural properties of single-gated (SG) and double-gated (DG) injection moulded blend of polybutylene terephthalate (PBT) and polycarbonate (PC) and its composites containing 15, 20 and 30?wt.% short glass fibres were investigated. In the DG mouldings, a weldline was formed by direct impingement of two opposing melt fronts (i.e. cold weld). It was found that tensile modulus was not affected by the weldline but flexural modulus decreased in the presence of weldline. For both specimen types, modulus increased linearly with volume fraction of fibres (? f), according to the rule-of-mixtures for moduli. The weldline integrity (WIF) factor for flexural modulus decreased linearly with increasing ? f. Results showed that tensile and flexural strengths for SG mouldings increase with in...

2008-01-01

274

Magnetic resonanse imaging in otorhinolaryngology. With special reference to the influence of factors upon NMR parameters and differential diagnosis of otorhinolaryngic lesions  

Energy Technology Data Exchange (ETDEWEB)

MRI diagnosis for malignant tumors are made possible by direct comparison to the results obtained by the brain and it seems possible to differentiate malignant tumors from other benign lesions. Cystic lesions, and mycotic sinusitis sometimes resemble malignant tumors in MR Image. In the present report, we investigated the relationships between the biochemical contents of cystic lesions and NMR-parameters to clarify why some inflammatory lesions appeared similar to malignant tumors in MRI. The variation of relaxation time depends upon the amount of protein in the cystic contents and the amount of glucose affects the relaxation time. We conclude that NMR-parameters are useful for the differential diagnosis of malignant tumors, cystic lesions and mycositic sinusitis by using the multiple variation analysis.

1987-07-01

275

Large scintillation cells for high sensitivity radon concentration measurements  

Energy Technology Data Exchange (ETDEWEB)

Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alpha source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm diameter plexiglass cell can be extended to at least 50 cm length without difficulty from ...

1983-07-01

276

Large scintillation cells for high sensitivity radon concentration measurements  

International Nuclear Information System (INIS)

Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alphy source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm diameter plexiglass cell can be extended to at least 50 cm length without difficulty from ...

277

Genetic Variation of Lodgepole Pine, Pinus contorta var. latifolia, Chemical and Physical Defenses that Affect Mountain Pine Beetle, Dendroctonus ponderosae, Attack and Tree Mortality  

British Library Electronic Table of Contents (United Kingdom)

Plant secondary chemistry is determined by both genetic and environmental factors, and while large intraspecific variation in secondary chemistry has been reported frequently, the levels of genetic variation of many secondary metabolites in forest trees in the context of potential resistance against pests have been rarely investigated. We examined the effect of tree genotype and environment/site on the variation in defensive secondary chemistry of lodgepole pine, Pinus contorta var. latifolia, against the fungus, Grosmannia clavigera (formerly known as Ophiostoma clavigerum), associated with the mountain pine beetle, Dendroctonus ponderosae. Terpenoids were analyzed in phloem samples from 887, 20-yr-old trees originating from 45 half-sibling families planted at two sites. Samples were coll...

2011-01-01

278

Factors affecting the development of the pressure differential in Upper Paleozoic gas reservoirs in the Sulige and Yulin areas of the Ordos Basin, China  

British Library Electronic Table of Contents (United Kingdom)

The Sulige gas field and the Yulin gas field are located in the north of the Ordos Basin. Reservoir pressure in the Sulige area is subnormal, whereas reservoirs in the Yulin area have normal hydrostatic pressure. This paper provides an explanation of this difference. The characteristics of reservoir sediment and formation water chemistry in the gas reservoirs of these two areas were analyzed. The results showed that both reservoirs have good sealing ability. Data of numerical simulation showed that tectonic uplift resulted in a great reduction in formation pressure in the northern Ordos Basin during the late Cretaceous period, and the decrease was greater in the Yulin gas field than in the Sulige gas field. However, because the total hydrocarbon-generating intensity of the Sulige area (<24...

2011-01-01

279

Esterification process to synthesize isopropyl chloroacetate catalyzed by lanthanum dodecyl sulfate  

International Nuclear Information System (INIS)

Isopropyl chloroacetate has been synthesized by esterification of chloroacetic acid and isopropanol, using lanthanum dodecyl sulfate (LDDS) as the catalyst. Various factors that affected the esterification have been investigated, such as reaction time, different water-carrying agent and the amount of catalyst. Under the condition of 1.2/1 molar ratio of isopropanol to chloroacetic acid, 1.0% catalyst (molar percent of chloroacetic acid), 2.5 h reaction time, 5 mL cyclohexane as water-carrying agent and reflux temperature, the esterification conversion of isopropyl chloroacetate reaches 98.3%. The catalytic activity of LDDS is almost equal to that of a Bronsted acid. LDDS, as one kind of water-tolerant Lewis acid, is an excellent catalyst compared to the traditional Lewis acid. (author)

280

Effective diffusion coefficient of radon in concrete, theory and method for field measurements  

International Nuclear Information System (INIS)

A linear diffusion model serves as the basis for determination of an effective radon diffusion coefficient in concrete. The coefficient was needed to later allow quantitative prediction of radon accumulation within and behind concrete walls after application of an impervious radon barrier. A resolution of certain discrepancies noted in the literature in the use of an effective diffusion coefficient to model diffusion of a radioactive gas through a porous medium is suggested. An outline of factors expected to affect the concrete physical structure and the effective diffusion coefficient of radon through it is also presented. Finally, a field method for evaluating effective radon diffusion coefficients in concrete is proposed and results of measurements performed on a concrete foundation wall are compared with similar published values of gas diffusion coefficients in concrete. (author).

281

Effect of On-Chip Magnetic Shielding for TES Microcalorimeters  

British Library Electronic Table of Contents (United Kingdom)

We investigated the magnet field dependence of the X-ray pulse height and the critical current of a Ti/Au bilayer TES micro-calorimeter. The pulse height was strongly affected by the magnetic field intensity applied perpendicularly to the TES surface. We found that the critical current at zero temperature, I c0, decreased by a factor of two by applying a magnet field of ?10??T. Our data are consistent with a TES sensitivity proportional to (I/I c0)?2/3, as predicted by the Ginzburg-Landau theory. This fact implies that the shape of the R?T curve of the TES is partly determined by the critical current of the superconductor. In order to make our TES microcalorimeters less sensitive to the external magnetic field, we fabricated devices equipped with on-chip magnetic shielding. One device has ...

2008-01-01

282

Detection of Visual Deficits in Aging DBA/2J Mice by Two Behavioral Assays  

British Library Electronic Table of Contents (United Kingdom)

Purpose: The DBA/2J mice have been used as an animal model for human pigmentary glaucoma. However, these mice develop various degrees of disease symptoms at different ages, making it difficult to detect pathological changes of retinal degeneration at glaucoma onset. The purpose of this study is to develop a non-invasive assay to identify individual mice that develop visual deficits. Materials and Methods: We apply two behavioral tests, a swimming test of visual discrimination and a test of optomotor response, to identify glaucomatous DBA/2J mice. We then examine whether the elevation of intraocular pressure (IOP), the common risk factor for glaucoma, affects visual performances of the DBA/2J mice. We further compare the retinal ganglion cell death, one of the signature glaucoma symptoms, i...

2011-01-01

283

Cost and sensitivity analysis for photovoltaic station in Kuwait  

Energy Technology Data Exchange (ETDEWEB)

A full analysis is shown in this paper for the cost of kWh generated from photovoltaic station located in Kuwait. By using a 21 years weather data for Kuwait, the yearly generated energy was found by proposing the PV station capacity with known panels tilt angle. The cost of kWh generated from PV station was compared with the kWh generated from conventional units in the country. A sensitivity analysis was done to some factors, capital cost per installed PV peak watt, discount rate, and operating peak hours, which affect the cost of kWh production from both PV and conventional units. If the PV station is proposed to be installed in Kuwait, the capital cost per PV installed peak watt must be less than today`s prices. (author)

1996-05-01

284

Climatic change and river ice breakup  

Energy Technology Data Exchange (ETDEWEB)

An overview of climatic factors and impact relative to river ice engineering and science is presented. An explanation of the fundamentals of climatic change is followed by a review of direct and indirect climatic influences that govern river ice breakup and related trends. Known responses of river ice to climatic change and potential future changes to ice breakup processes are described along with the probable ecological and socio-economic consequences of these changes. Changes in engineering approaches to accommodate the present ice regime and predicted changes in climatic variables that affect river ice processes and reduce the vulnerability of infrastructure and ecosystems to climatic change are examined. Future research on the links between river ice and stream ecology is suggested to identify ecological concerns that may result from changes in river ice regimes induced by climatic change. 60 refs., 3 figs.

2003-07-01

285

Biopolymer system for permeability modification in porous media  

Energy Technology Data Exchange (ETDEWEB)

New technologies are needed to reduce the current high rate of well abandonment. Improved sweep efficiency, reservoir conformance, and permeability modification can have a significant impact on oil recovery processes. Microorganisms can be used to selectively plug high-permeability zones to improve sweep efficiency and impart conformance control. Studies of a promising microbial system for polymer production were conducted to evaluate reservoir conditions in which this system would be effective. Factors which can affect microbial growth and polymer production include salinity, pH, temperature, divalent ions, presence of residual oil, and rock matrix. Flask tests and coreflooding experiments were conducted to optimize and evaluate the effectiveness of this system. Nuclear magnetic resonance imaging (NMRI) was used to visualize microbial polymer production in porous media. Changes in fluid distribution within the pore system of the core were ...

1995-12-31

286

Beam emittance measurements of ORNL negative ion sources  

Energy Technology Data Exchange (ETDEWEB)

The emittances of hydrogen and deuterium negative ion beams produced by volume ion sources have been measured in a transverse plane normal to the beam trajectory. The extraction voltage was varied from 10 to 40 kV, and the transverse magnetic field in the Penning discharges was varied from 0.1 to 0.2 T. Measurements were made on beams with current densities up to 60 mA/cm/sup 2/ at Oak Ridge National Laboratory with an emittance scanner originally developed at Los Alamos National Laboratory. The beam profile at the scanner can be used to improve the accuracy of the emittance measurements. Other factors affecting emittance measurements are discussed. This analysis may be applicable to other ion sources. 6 figs.

1989-01-01

287

Assessing vineyard water status using the reflectance based Water Index  

British Library Electronic Table of Contents (United Kingdom)

In the Mediterranean arc, vines for wine production are mainly grown without the support of irrigation. Under such conditions, site variables affecting the extent and seasonal timing of water deficits are the dominant environmental constraints for grape production. Moreover, water availability and vine water status are the factors most comprehensively determining fruit composition and, thus, wine quality. Therefore, monitoring the extent of water stress in vines might be a valuable tool for the optimisation of grape yield and quality. The objective of this study was to evaluate the feasibility of using the reflectance based Water Index (WI) to estimate vine water status at the leaf and canopy levels. The study was conducted on Vitis vinifera cv. Chardonnay potted plants submitted to contra...

2010-01-01

288

Application of Risk Management for Control and Monitoring Systems  

CERN Document Server

This paper presents an application of the state of the art and new trends for risk management of safety-related control and monitoring systems, currently applied in the industry. These techniques not only enable to manage safety and reliability issues but they also help in the control of quality and economic factors affected by the availability and maintenance of the system. The method includes an unambiguous definition of the system in terms of functions and a systematic analysis of hazardous situations, undesired events and possible malfunctions. It also includes the identification and quantification of the risk associated to the system. The required risk reduction is specified in terms of safety integrity levels. The safety integrity level results in requirements, preventive measures, possible improvements and recommendations to assure the satisfactory management of the risk.

2001-01-01

289

Analysis of nonisothermal injection and falloff tests in layered reservoirs  

Energy Technology Data Exchange (ETDEWEB)

The effects of reservoir layering and gravity segregation on nonisothermal injection and falloff tests are investigated. Results show that layering does not affect injection or falloff data if all the layers are permeable and accept fluids from the wellbore. In such cases, the average permeability, skin factor, and distance to the thermal front can be calculated using the techniques developed for homogeneous reservoirs. Special considerations have to be taken for cases where several layers are impermeable or are permeable but do not accept fluids of the well face. In the first case (impermeable layers), knowledge of the total thickness of the permeable layers is required for the existing techniques to be applied successfully. In the second case, the existing techniques cannot be applied, but characteristic responses from injection and falloff test are seen; therefore, this case can be identified easily. 13 refs., 8 figs.

1985-03-01

290

A study on the degradation of coating and corrosion of ship`s hull based on the probabilistic approach  

Energy Technology Data Exchange (ETDEWEB)

Corrosion is said to be the most dominant factor which affects the physical life of ships and offshore structures. In order to secure the structural safety of ships and offshore structures, it is necessary to take measures to corrosion based on the prediction of condition of progressive corrosion. But such prediction is difficult because the behavior of corrosion`s progress is probabilistic. In this paper, probabilistic model, which could evaluate the degradation of coatings and the successive corrosion of steel members, was proposed in order to explain the tendency of the actual corrosion conditions of existing ships. Then, statistical inferences on the proposed model were made by applying the actual data on plate thickness measurements of Bulk Carriers` Cargo Hold. And validity of the proposed model was verified.

1996-12-31

291

The impact of fatigue strength considerations for the lifetime management for pumped-storage power plants  

Energy Technology Data Exchange (ETDEWEB)

Due to changed operational conditions and because of the increasing age of several hydro power plant components, there is an increasing risk of damages and the control of degradation mechanisms is of increasing significance. Therefore lifetime considerations for safety relevant components in pumped-storage plants become more and more important. The development of a lifetime management system, in conjunction with monitoring systems and specific surveillance for a group of pumped-storage power plants of different ages and in a wide range of power output is presented. The special focus is on the impact of fatigue strength considerations within this framework. The applied procedure will be described for typical mechanical components in pumped-storage plants exemplarily. (orig.)

2010-07-01

292

The elastic plastic behaviour of a 1/2% Cr Mo V steam turbine steel during high strain thermal fatigue  

International Nuclear Information System (INIS)

High strain fatigue problem in steam turbine. Cyclic stress strain hysteresis loops and stress relaxation behaviour in 16 h dwell period tests. Variation of stress and strain during tests under nominally strain controlled conditions. Definition of test conditions and of criteria for crack initiation and failure. Comparison of reverse bend and push pull failure data. (orig.) 891 RW/orig. 892 RKD.

293

The EU HT test programme of ITER primary wall small scale mock ups  

International Nuclear Information System (INIS)

This paper summarises the main results obtained so far in the frame of the EU Home Team test programme of ITER primary wall small scale mock ups. It describes briefly the fabrication method of the mock ups, the test conditions and the main results obtained with high heat flux and thermal fatigue tests of Cu alloy/stainless steel and beryllium/Cu alloy/stainless steel mock ups. The results obtained so far show good thermal fatigue performance and operation margin of the ITER primary first wall concept. (author)

1998-09-07

294

Results of UT training for defect detection and sizing technique using specimens with fatigue crack and SCC  

International Nuclear Information System (INIS)

At the importance increase of UT (ultrasonic testing) with the application of rules on fitness-for-service for nuclear power plants, JAPEIC (Japan power engineering and inspection corporation) started education training for defect detection and sizing technique. Weld joints specimen with EDM (Electro-Discharged Machining) notches, fatigue cracks and intergranular stress corrosion cracks were tested and practiced repeatedly based on a modified ultrasonic method and the defect size measuring accuracy of the trainees was surely improved. Results of the blind test confirmed effectiveness of education training. (T. Tanaka)

2005-04-01

295

Residual Stress Field Analysis and Prediction in Nitrided Tool Steel  

British Library Electronic Table of Contents (United Kingdom)

Residual stresses are present in engineering components as an unintended consequence of manufacturing processes, but they are also deliberately introduced to beneficial effect during surface engineering procedures. Plasma nitriding is a process of particular importance for forming tools and dies, giving significant advantages in wear, and fatigue resistance through the generation of near-surface compressive residual stresses. A precise knowledge of the level and distribution of residual stresses that exist in engineering components is necessary for an accurate design and prediction of a component's fatigue resistance. However, measurement of residual stresses is not always possible, which is especially true for forming tools. Therefore, other methods for residual stress evaluation and pred...

2011-01-01

296

Oster | Best sexual wellness info  

Wastenet

...Oster | Best sexual wellness info Best sexual wellness info Home Posts Tagged Oster Oster Professional 103 Stim-U-Lax Massager Reviews Made of 100% ball bearing construction Traditional frame design with special frame contour to fit hand and reduce hand fatigue Chrome housing and rubber hand pad Heavy-duty, single speed UL approved 120v This lightweight therapeutic massager combines the advantages of hand and mechanical massage. Its special contoured design reduces hand fatigue and its universal ...

297

Main achievements of the EU HT test programme of ITER primary wall small scale mock ups  

International Nuclear Information System (INIS)

This paper presents the main achievements of the European Home Team (EU HT) test programme of ITER primary wall small scale mock ups. It describes briefly the fabrication method of the mock ups, the test conditions and the main results obtained with high heat flux and thermal fatigue tests of Cu alloy/stainless steel and beryllium/Cu alloy/stainless steel mock ups. The results obtained so far show very good thermal fatigue performance and operation margin of the ITER primary first wall concept.

2000-11-01

298

Low cycle fatigue behaviour of a 4th generation Ni-base single-crystal superalloy TMS-138  

Energy Technology Data Exchange (ETDEWEB)

Low cycle fatigue (LCF) of a fourth-generation single-crystal (SC) Ni-base superalloy TMS-138 was studied by comparison with a typical third-generation (TMS-75) and a second-generation (CMSX-4) Ni-base SC superalloys. TMS-138 exhibits improved LCF behaviour under a condition of the R ratio of 0 at temperatures of 1073 K and 1173 K. The addition of refractory elements resulted in a remarkable improvement of the LCF properties compared to those of the reference superalloys due to the different microstructure developed in TMS-138. (orig.)

2004-07-01

299

Effect of intense plastic straining on microstructure and mechanical properties of an Al-Mg-Sc alloy  

International Nuclear Information System (INIS)

An Al-5%Mg-0.18%Mn-0.2%Sc-0.08%Zr-0.002%Be was subjected to equal-channel angular extrusion up to true strains of #approx#3 and #approx#8, that resulted in the formation of partially recrystallized and fully recrystallized structure, respectively. It was shown that the alloy with partially recrystallized structure exhibits highest strength and ductility. The material with fully recrystallized structure showed lowest fatigue crack growth rate and highest value of fracture toughness. Reasons of this unusual effect of microstructure on crack propagation resistance under fatigue are discussed.

2010-07-01

300

Damage mechanism in high temperature fatigue of alloy 800 H  

Energy Technology Data Exchange (ETDEWEB)

In order to investigate the influence of grain boundary cavities on the life time of Alloy 800 H various fatigue tests have been performed at 800/sup 0/C. Cavity formation has been observed only in asymmetrical tests. Compared to the corresponding symmetrical tests, the cyclic life time is shorter. As the cavitation damage increases, the ratio of life times in vacuum and in air steadily decreases from an initial value of 5. In extreme cases it can reach a value close to 1. In this case, cavitation damage dominates over the usual damage mechanism, which is cracks from the surface.

1986-09-01

301

Pump application desk book  

Energy Technology Data Exchange (ETDEWEB)

The large number of forms and types of pump equipment in common use have different purposes and varying application requirements. This text has been prepared to bring together necessary information for those who are required to select and apply pumps in systems for all kinds of fluids and purposes. It is not a design manual. It limits the discussion of design to those factors which are necessary for an understanding of pump operation. The book contains not only descriptive information of many types of designs, but also the effect of design variation on use, economy, and reliability. Systems, an integral part of application, are discussed, so that the user of such equipment may properly select and install machines to reliably and economically satisfy his requirements. Reading of appropriate sections of the text will indicate possible problems to be avoided, and economics to be gained. The engineering design of pumps is a science; their proper application is an art. ...

1990-01-01

302

Modeling of electricity consumption in the Asian gaming and tourism center - Macao SAR, People's Republic of China  

Energy Technology Data Exchange (ETDEWEB)

The use of electricity is indispensable to modern life. As Macao Special Administrative Region becomes a gaming and tourism center in Asia, modeling the consumption of electricity is critical to Macao's economic development. The purposes of this paper are to conduct an extensive literature review on modeling of electricity consumption, and to identify key climatic, demographic, economic and/or industrial factors that may affect the electricity consumption of a country/city. It was identified that the five factors, namely temperature, population, the number of tourists, hotel room occupancy and days per month, could be used to characterize Macao's monthly electricity consumption. Three selected approaches including multiple regression, artificial neural network (ANN) and wavelet ANN were used to derive mathematical models of the electricity consumption. The accuracy of these models was assessed by using the ...

2008-05-15

303

Effects of the Temperature Lag on Thermoluminescence Analysis with Hoogenstraaten's Heating Rate Method  

International Nuclear Information System (INIS)

Hoogenstraaten's heating rate method has generally been considered as a reliable method for determining thermoluminescence trapping parameters of first order glow peaks. However, experience has shown that in some cases the deviation between the heating rate method and glow curve fitting method can be quite significant (considering only the linear part of the heating rate plot, of course). In this study it is shown that one of the main reasons for this deviation can be a systematic increase of a temperature lag between the measured and real temperature of the sample with increasing heating rate. It appears that this systematic increase of the temperature lag affects the method in the range of low heating rates (linear part of the heating rates plots) more than has been previously realised. The effect of the temperature lag on Hoogenstraaten's heating rate method is a decrease in activation energy and frequency factor and is more important for ...

1998-07-05

304

Effects of the Temperature Lag on Thermoluminescence Analysis with Hoogenstraaten's Heating Rate Method  

Energy Technology Data Exchange (ETDEWEB)

Hoogenstraaten's heating rate method has generally been considered as a reliable method for determining thermoluminescence trapping parameters of first order glow peaks. However, experience has shown that in some cases the deviation between the heating rate method and glow curve fitting method can be quite significant (considering only the linear part of the heating rate plot, of course). In this study it is shown that one of the main reasons for this deviation can be a systematic increase of a temperature lag between the measured and real temperature of the sample with increasing heating rate. It appears that this systematic increase of the temperature lag affects the method in the range of low heating rates (linear part of the heating rates plots) more than has been previously realised. The effect of the temperature lag on Hoogenstraaten's heating rate method is a decrease in activation energy and frequency factor and is ...

1999-07-01

305

Desorption of polycyclic aromatic hydrocarbons (PAH`s) from calcite and quartz sediments to seawater  

Energy Technology Data Exchange (ETDEWEB)

Polycyclic aromatic hydrocarbons (PAH`s) are ubiquitous hydrophobic organic pollutants in the marine environment. Many of the PAM`s are classified as possible carcinogens or mutagens, therefore they are of considerable concern to human and environmental health. The highest concentrations are found in coastal regions due to anthropogenic activities including oil spills, tanker operations, incomplete fossil fuel combustion and runoff. The sources and distribution of PAM`s in sediments are fairly well known, while the fate and transport of PAH`s in the marine environment are less known. Desorption is an important factor influencing the fate and transport of hydrophobic molecules at the seawater/sediment interface. The desorption of PAH`s from contaminated marine sediments to the water column/pore water affects the availability of the pollutant to biota. The sorption of PAH`s is determined in part by the organic carbon content of the sediments. The ...

1996-12-31

306

5,10 Methylenetetrahydrofolate reductase genetic polymorphism as a risk factor for neural tube defects  

Science.gov (United States)

Persons with a thermolabile form of the enzyme 5,10 methylenetetrahydrofolate reductase (MTHFR) have reduced enzyme activity and increased plasma homocysteine which can be lowered by supplemental folic acid. Thermolability of the enzyme has recently been shown to be caused by a common mutation (677C{sup {r_arrow}}T) in the MTHFR gene. We studied 41 fibroblast cultures from NTD-affected fetuses and compared their genotypes with those of 109 blood specimens from individuals in the general population. 677C{sup {r_arrow}}T homozygosity was associated with a 7.2 fold increased risk for NTDs (95% confidence interval: 1.8-30.3; p value: 0.001). These preliminary data suggest that the 677C{sup {r_arrow}}T polymorphism of the MTHFR gene is a risk factor for spina bifida and anencephaly that may provide a partial biologic explanation for why folic acid prevents these types of NTD. 13 refs., 1 fig., 1 tab.

1996-06-28

307

Rainfall effect on single-vehicle crash severities using polychotomous response models.  

Science.gov (United States)

As part of the Wisconsin road weather safety initiative, the objective of this study is to assess the effects of rainfall on the severity of single-vehicle crashes on Wisconsin interstate highways utilizing polychotomous response models. Weather-related factors considered in this study include estimated rainfall intensity for 15 min prior to a crash occurrence, water film depth, temperature, wind speed/direction, stopping sight distance and deficiency of car-following distance at the crash moment. For locations with unknown weather information, data were interpolated using the inverse squared distance method. Non-weather factors such as road geometrics, traffic conditions, collision types, vehicle types, and driver and temporal attributes were also considered. Two types of polychotomous response models were compared: ordinal logistic and sequential logistic regressions. The sequential logistic regression was tested with forward and backward ...

2009-08-14

308

Factors Associated with Iowa Rural Hospitals' Decision to Convert to Critical Access Hospital Status  

Science.gov (United States)

Context: The Balanced Budget Act (BBA) of 1997 allowed some rural hospitals meeting certain requirements to convert to Critical Access Hospitals (CAHs) and changed their Medicare reimbursement from prospective to cost-based. Some subsequent CAH-related laws reduced restrictions and increased payments, and the number of CAHs grew rapidly. Purpose: To examine factors related to hospitals' decisions to convert and time to CAH conversion. Methods: Eighty-nine rural hospitals in Iowa were characterized and observed from 1998 to 2005. Cox proportional hazards models were used to identify the determinants of time to CAH conversion. Findings: T-test and one-covariate Cox regression indicated that, in 1998, Iowa rural hospitals with more staffed beds, discharges, and acute inpatient days, higher operating margin, lower skilled swing bed days relative to acute days, and located in relatively high density counties were more likely to convert later or not convert before 2006. ...

2008-12-01

309

Computational fluid dynamic analysis of core bypass flow phenomena in a prismatic VHTR  

International Nuclear Information System (INIS)

The core bypass flow in a prismatic very high temperature reactor (VHTR) is an important design consideration and can have considerable impact on the condition of reactor core internals including fuels. The interstitial gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The occurrence of hot spots in the core and lower plenum and hot streaking in the lower plenum (regions of very hot gas flow) are affected by bypass flow. In the present study, three-dimensional computational fluid dynamic (CFD) calculations of a typical prismatic VHTR are conducted to better understand bypass flow phenomena and establish an evaluation method for the reactor core using the commercial CFD code FLUENT. Parametric calculations changing several ...

2010-09-01

310

Computational Fluid Dynamic Analysis of Core Bypass Flow Phenomena in a Prismatic VHTR  

Energy Technology Data Exchange (ETDEWEB)

The core bypass flow in a prismatic very high temperature gas-cooled reactor (VHTR) is one of the important design considerations which impacts considerably on the integrity of reactor core internals including operating fuels. The interstitial gaps are an inherent presence in the reactor core because of tolerances in manufacturing the blocks and the inexact nature of their installation. Furthermore, the geometry of the graphite blocks changes over the lifetime of the reactor because of thermal expansion and irradiation damage. The occurrence of hot spots in the core and lower plenum and hot streaking in the lower plenum (regions of very hot gas flow) will be affected by the bypass flow. In the present study, three-dimensional computational fluid dynamic (CFD) calculations of a typical prismatic VHTR are conducted to understand better the bypass flow phenomenon and establish the evaluation method in the reactor core using commercial CFD code FLUENT. Parametric ...

2010-09-01

312

Thermomechanical fatigue of coated single-crystalline materials; Thermomechanische Ermuedung beschichteter Einkristallwerkstoffe  

Energy Technology Data Exchange (ETDEWEB)

The interdiffusion behaviour of MCrAlY-coats on polycrystalline and single-crystalline materials of a similar composition (IN 738 LC/SC 16)shows similar interdiffusion characteristics. TCF-tests, where stress is generated by temperature and sample geometry at the edges of a disk-shaped sample, show that it is possible to differentiate betwee crack resistance of coated and uncoated samples. This method is also suitable for screening tests with different coat thicknesses. Coating of the edge area must, however, be done with great diligence in order to prevent coat thickness variation as results would then not be reproducable. Contrary to TCF (thermal cycle fatigue) TMF-tests (thermal mechanical fatigue)allow to set the stress states that one wishes to test. This method is therefore well suited for testing under operating conditions.(orig.) [German] Im Rahmen dieser Arbeit wurde gezeigt, dass das Interdiffusionsverhalten von MCrAlY-Schichten auf ...

1998-07-01

313

Mechanics and mechanisms of cyclic fatigue-crack propagation in transformation-toughened zirconia ceramics  

Energy Technology Data Exchange (ETDEWEB)

Damage and cyclic fatigue failure under alternating loading in transformation-toughened zirconia ceramics is reviewed and compared to corresponding behavior under quasi-static loading (static fatigue). Current understanding of the role of transformation toughening in influencing cyclic fatigue-crack propagation behavior is examined based on studies which altered the extent of the tetragonal-to-monoclinic phase transformation in MG-PSZ through subeutectoid aging. These studies suggest that near-tip computations of the crack-driving force (in terms of the local stress intensity) can be used to predict crack-growth behavior under constant amplitude and variable-amplitude (spectrum) loading, using spatially resolved Raman spectroscopy to measure the extent of the transformation zones. In addition, results are reviewed which rationalize distinctions between the crack-growth behavior of preexisting, long'' (> ...

1992-05-01

314

Long-term high temperature fatigue properties of new structural materials for nuclear reactors  

Energy Technology Data Exchange (ETDEWEB)

This study aims to evaluate fatigue strength properties at long-term high temperature of 316FR steels developed for structural materials applied to high temperature components in the 21st Century such as Demonstration FBR, and to obtain design indicators on high temperature strength properties arranged on chemical composition and grain size on a base of 316FR stainless steels. As results obtained by the study, it could be found that as a result of systematic examinations on temperatures and strain rate dependence on symmetric triangular strain waveform of 316FR steels between 500 to 600degC, temperature of fatigue life, and strain rate dependence can be integrally evaluated by a parameter analysis method developed by authors and life prediction at ultra low strain rate of less than 10{sup -6}/s and its experimental verification could be carried out. And, it was also found that as a result of evaluation of creep fatigue life ...

2003-01-01

315

Long-term high temperature fatigue properties of new structural materials for nuclear reactors  

International Nuclear Information System (INIS)

This study aims to evaluate fatigue strength properties at long-term high temperature of 316FR steels developed for structural materials applied to high temperature components in the 21st Century such as Demonstration FBR, and to obtain design indicators on high temperature strength properties arranged on chemical composition and grain size on a base of 316FR stainless steels. As results obtained by the study, it could be found that as a result of systematic examinations on temperatures and strain rate dependence on symmetric triangular strain waveform of 316FR steels between 500 to 600degC, temperature of fatigue life, and strain rate dependence can be integrally evaluated by a parameter analysis method developed by authors and life prediction at ultra low strain rate of less than 10"-"6/s and its experimental verification could be carried out. And, it was also found that as a result of evaluation of creep fatigue life and ...

2003-01-01

316

High temperature strength properties of Mod.9Cr-1Mo steel forging weld zone  

International Nuclear Information System (INIS)

In the feasibility study on commercialized FBR systems, the application of 12Cr steel, with its physical properties and high-temperature strength properties, as structural material is considered in order to greatly reduce construction costs by compacted instruments and structures. In this report, creep, fatigue and the creep-fatigue properties of Mod.9Cr-1Mo steel forging (thickness 550mm) weld, representing conventional steels, were evaluated in order to obtain the needed basic data for the evaluation of the high-temperature strength of 12Cr steel weld. The results obtained are as follows: (1) Metal suitable for HAZ was made by applying thermal treatment to simulate the thermal hysteresis during welding to clearly define creep and fatigue properties in a HAZ softened zone. (2) Creep strength of the weld metal and the welded joint was equal to that of the base metal. However, the welded joint ruptured in the HAZ softened ...

317

Significance of common cause failures in level-l PSA and techniques for reducing its impact on core damage frequency  

International Nuclear Information System (INIS)

Failure of multiple components due to a common cause represents one of the most important issues in evaluation of system reliability or unavailability. The frequency of such events has relatively low expectancy, when compared to random failures, which affect individual components. However, in many cases the consequence is a direct loss of safety system or mitigative safety function. For this reason, the modeling of a common cause failure (CCF) and its presentation in fault tree structure is of the uttermost importance in probabilistic safety analyses (PSA). Amongst the different techniques available to reduce the impact of common cause failures, the most important operations related technique, is that of staggered testing. In the TAPP 3,4 Level-1 PSA it was found that the contribution of Common Cause Failures to the Core Damage Frequency (CDF) was significant. The Common Cause Failures were modeled using the Alpha Factor Model. This model is ...

2005-12-01

318

Thermal-mechanical test on ITER primary first wall mock-ups  

International Nuclear Information System (INIS)

In 1998, in the frame of the ITER EDA phase, an European R and D Programme for the Blanket Design was implemented for developing and selecting the materials and the relevant fabrication procedures for manufacturing the shielding modules of the ITER Primary Wall. The fabrication of several Beryllium armored small scale mock-ups, reproducing representative portions of a Primary Wall panels, was also launched (Fusion Technol. (1998) 195). Further experimental activities were also programmed for investigating the thermal-mechanical behavior of these mock-ups at high heat flux and under thermal fatigue tests. In 2001, the ITER European Home Team decided to assign to ENEA a contract for the thermal fatigue testing of six mock-ups aiming at verifying the reliability of the Beryllium/Dispersion Strengthened Copper alloy/Stainless Steel and Beryllium/Precipitation hardened Copper alloy/Stainless Steel joints manufactured by solid Hot Isostatic Pressing ...

2002-11-01

319

Results of reliability test program on light water reactor piping  

Energy Technology Data Exchange (ETDEWEB)

The Japan Atomic Energy Research Institute has conducted a piping reliability test program to demonstrate the safety and reliability of light water reactor primary piping. In this program, pipe fatigue test, leak-before-break (LBB) verification test and pipe rupture test were carried out to examine the integrity of piping, to verify the LBB and to demonstrate the effectiveness of protective measures against jet impingement and pipe whip loads under a pipe rupture event.In the pipe fatigue test, a procedure to predict the fatigue crack growth was developed, and the integrity of piping during the plant service life was evaluated. In the LBB verification test, the pipe fracture test and the leak rate test were performed to verify the LBB in the primary piping.In the pipe rupture test, the influence of jet impingement on the target disk and the deformation behavior of whipping pipe and restraint were investigated. Using the ...

1994-12-01

320

Overview of reliability test program on primary coolant piping of light water reactors  

Energy Technology Data Exchange (ETDEWEB)

Upon request by the Science and Technology Agency of Japanese Government, the Japan Atomic Energy Research Institute has conducted Piping Reliability Test Program to demonstrate the safety and reliability of light water reactor primary pipings. In this report, the results of the program are summarized. In the test program, pipe fatigue tests, Leak-Before-Break (LBB) verification tests and pipe rupture tests were carried out to examine the integrity of pipings, to verify the LBB concept and to demonstrate the effectiveness of the protective measures against jet impingement and pipe whip under pipe rupture event, respectively. In the pipe fatigue tests, a procedure to predict the fatigue crack growth was developed and the integrity of piping during plant service life was demonstrated. In the LBB verification tests, pipe fracture tests and leak rate tests were performed using cracked pipes. Based on the test results, LBB in ...

1993-10-01

321

Manufacturing and testing of monoblock tungsten small-scale mock-ups  

Energy Technology Data Exchange (ETDEWEB)

In the frame of the European Technology R and D program for ITER, and in the area of High Heat Flux plasma facing Components (HHFC), representative small-scale mock-ups were manufactured and tested to compare different concepts and joining technologies (i.e. active brazing, Hot Isostatic Pressing (HIPping), diffusion bonding, etc.). On the basis of the results obtained by thermal fatigue tests, the monoblock concept resulted to be the most promising one, particularly when the HIPping manufacturing technology is used. Within this program, ENEA manufactured tungsten monoblock mock-ups by using the HIPping technology. The mock-ups were tested with respect to thermal fatigue and, upon screening tests, the best performance obtained was 15 MW/m{sup 2} for 200 cycles. One of these mock-ups was enclosed in the 'Paride' neutron irradiation campaign. This campaign has the scope of enlarging the available database on the performance ...

2001-10-01

322

Manufacturing and testing of monoblock tungsten small-scale mock-ups  

International Nuclear Information System (INIS)

In the frame of the European Technology R and D program for ITER, and in the area of High Heat Flux plasma facing Components (HHFC), representative small-scale mock-ups were manufactured and tested to compare different concepts and joining technologies (i.e. active brazing, Hot Isostatic Pressing (HIPping), diffusion bonding, etc.). On the basis of the results obtained by thermal fatigue tests, the monoblock concept resulted to be the most promising one, particularly when the HIPping manufacturing technology is used. Within this program, ENEA manufactured tungsten monoblock mock-ups by using the HIPping technology. The mock-ups were tested with respect to thermal fatigue and, upon screening tests, the best performance obtained was 15 MW/m"2 for 200 cycles. One of these mock-ups was enclosed in the 'Paride' neutron irradiation campaign. This campaign has the scope of enlarging the available database on the performance degradation of prototypical ...

2001-10-01

323

Fatigue and creep crack growth of Alloy 800 and Alloy 617 at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

A common evaluation is given for creep crack growth and fatigue crack growth experiments which have been performed at the companies ABB, Siemens-KWU and KFA. The materials under investigation were X10NiCrAlTi32 20 (Alloy 800) and NiCr22Col2Mo (Alloy 617). Several production lots and semi-finished materials as well as welded materials have been tested. Testing techniques differed at the different labs. In order to eliminate the influence of individual testing techniques, material from some production lots was investigated at different labs. The given data cover fatigue crack growth (the materials were tested between room temperature and 1050[sup o]C; the influence of temperature, R-ratio, and frequency was investigated) and creep crack growth (Alloy 800 was tested between 550sup(o)C and 900sup(o)C, Inconel 617 between 800sup(o)C and 1000sup(o)C; the evaluation was done on the basis of the fracture mechanics parameters Ksub(1) and Csup(*)). ...

1992-01-01

324

Fatigue and creep crack growth of Alloy 800 and Alloy 617 at high temperatures  

International Nuclear Information System (INIS)

A common evaluation is given for creep crack growth and fatigue crack growth experiments which have been performed at the companies ABB, Siemens-KWU and KFA. The materials under investigation were X10NiCrAlTi32 20 (Alloy 800) and NiCr22Col2Mo (Alloy 617). Several production lots and semi-finished materials as well as welded materials have been tested. Testing techniques differed at the different labs. In order to eliminate the influence of individual testing techniques, material from some production lots was investigated at different labs. The given data cover fatigue crack growth (the materials were tested between room temperature and 1050"oC; the influence of temperature, R-ratio, and frequency was investigated) and creep crack growth (Alloy 800 was tested between 550sup(o)C and 900sup(o)C, Inconel 617 between 800sup(o)C and 1000sup(o)C; the evaluation was done on the basis of the fracture mechanics parameters Ksub(1) and Csup(*)). (Author).

325

Crack tip oxidation of a superalloy in molten nitrate salt  

Energy Technology Data Exchange (ETDEWEB)

Alloy 800 has been proposed for use in the receiver tube panel arrays of advanced solar central receiver (SCR) designs. In this application the alloy will be exposed to a molten mixture of sodium and potassium nitrate salts at temperatures ranging up to approximately 600/sup 0/C While these salts are routinely used in a variety of applications including metal heat treating and process heat transfer, common industrial experience has been limited to maximum temperatures of 400/sup 0/C - 450/sup 0/C. There is, therefore, considerable interest in the compatibility of these salts with containment alloys at the higher temperatures associated with SCR designs. Additionally, the containment alloy may be subject to thermally induced fatigue damage resulting from intermittent cloud cover and diurnal cycling. Previous work has found that slower near-threshold fatigue crack growth rates (FCGR) in Alloy 800 result when it is tested in molten nitrate salt at ...

1983-04-01

326

A comparison of the low-cycle fatigue behavior of Alloy 800 and Alloy 800H  

International Nuclear Information System (INIS)

At 650"0C, the low-cycle fatigue life was essentially the same for the two alloys on the basis of strain amplitude, but Alloy 800H had a longer life on the basis of stress amplitude. A 500"0C, Alloy 800 and 800H exhibited longer fatigue lifetime than at 650"0C, with Alloy 800 exhibiting a 2-3 times longer life than Alloy 800H when compared on the basis of plastic strain range, whereas the difference was less pronounced when compared on the basis of stress amplitude. When a creep effect was introduced either by way of a hold time or a reduced frequency, Alloy 800 exhibited a greater reduction in life than did Alloy 800H. The dislocation structure changed from planar to cellular with increase in strain range, and extensive precipitation of M_2_3C_6 was noted within the grains for Alloy 800H and along grain boundaries for both alloys. (Auth.).

327

A comparison of the low cycle fatigue behavior of alloy 800 and alloy 800H  

International Nuclear Information System (INIS)

The low cycle fatigue testing was carried out to provide a basis for comparison of the behavior of the two kinds of Alloy 800 (low carbon Alloy 800 and high carbon Alloy 800H). The testing was done at temperatures of 500"0C and 650"0C either with or without hold. The results obtained were as follows: (1) At 650"0C, the low-cycle fatigue life was essentially the same for the two alloys on the basis of strain amplitude, but Alloy 800H had a longer life on the basis of stress amplitude. (2) At 500"0C, the two alloys exhibited longer lives than at 650"0C, with Alloy 800 exhibiting 2-3 times longer life than Alloy 800H when compared on the basis of plastic strain range. At this temperature the stress range showed the maximum for Alloy 800H. (3) When a creep effect was introduced either by way of a hold time or a reduced frequency, Alloy 800 exhibited a greater reduction in life than in Alloy 800H. (4) At lower temperature the strain aging phenomena ...

1979-06-01

328

Aging of Pentaerythritol Tetranitrate (PETN)  

Science.gov (United States)

Pentaerythritol tetranitrate (PETN) is a relatively sensitive explosive used in many electroexplosive devices as well as in medicine. Of primary interest to LLNL is its use in items such as exploding bridgewire (EBW) detonators and exploding bridge foil initiators (EFI). In these devices the crystalline powder is pressed into a granular, low-density compact that can be initiated by an exploding wire or foil. The long-term stability of this pressed compact is of interest to weapon stockpile lifetime prediction studies. Key points about potential aging mechanisms can be summarized as follows: (1) There are a number of factors that can contribute to PETN instability. These include particle size, polymorphic phase transitions, crystal structure, impurities, moisture, occlusions, chemical incompatibility and biological (microorganism) action. of these factors the most important for long-term aging of high surface area powders used in detonators ...

2009-04-22

330

The role of fatigue variability in life prediction of an #alpha#+#beta# titanium alloy  

International Nuclear Information System (INIS)

The fatigue life variability of the #alpha#+#beta# titanium alloy, Ti-6Al-2Sn-4Zr-6Mo increased with decreasing stress level. The variability in life was found to be due to segregation of lives due to two failure mechanisms. A bimodal cumulative distribution model was shown to accurately describe the combined failure modes. The nominal failure processes for the two regimes were similar, with crack nucleation occurring in equiaxed #alpha#p particles, irrespective of life or stress level. However the variability in life was not controlled by the size of the crack-nucleating #alpha#p, but rather by the ability of the material to distribute deformation and avoid early crack nucleation.

2004-06-10

331

Surge-line thermal stratification: Displacements and fatigue damage computations  

Energy Technology Data Exchange (ETDEWEB)

Slow, unexpected displacements have been experienced in most pressurized water reactor (PWR) surge lines. Sometimes, these displacement lead to gap closure at the pipe whip restraints. These movements occur because of thermal stratification. This movement has the potential to increase stresses to valves, which may exceed the material yield stress. To understand this phenomenon, Framatome, Commissariat a l'Energie Atomique, and Electricite de France have undertaken large programs for the study of (1) thermal-hydraulic tests with a half-scale Plexiglas surge line, (2) thermal-hydraulic computations of permanent states and transients with a two-dimensional model, and (3) mechanical analysis of displacements and computation of fatigue damage due to stratification. This paper deals with the last subject. Avoiding stratification in piping by process modifications is difficult because of the high flow rate needed. Alternative solutions for coping with ...

1989-01-01

332

Structure transformation and gain in properties of cast high-temperature T-6242 alloy by thermo-hydrogen treatment  

International Nuclear Information System (INIS)

Thermohydrogen treatment effect on microstructure and mechanical properties is studied for a cast heat resistant pseudo-#alpha#-titanium alloy Ti-6242 (Ti-6Al-2Sn-4Zn-2Mo) widely used as a heat resistant material with operating temperature up to 500 deg C. It is shown that reversible hydrogen alloying is a promising alternative to thermomechanical treatment for transformation of (#alpha#+#beta#)-titanium alloy structure. The application of thermohydrogen treatment is noted to be of particular efficiency for shaped casting technology as it allows a noticeable increase of mechanical properties at a lower cost. The alloy after thermohydrogen treatment and subsequent heat treatment in the (#alpha#+#beta#) - range possesses high values of yield strength fatigue properties, creep resistance and has a satisfactory ductility. A consideration is also given to thermohydrogen treatment effect on fatigue crack propagation and impact strength

333

No detectable XMRV in subjects with chronic fatigue syndrome from Quebec  

British Library Electronic Table of Contents (United Kingdom)

We investigated the presence of XMRV in a cohort of Quebec patients with chronic fatigue syndrome (CFS). DNA was purified from activated peripheral blood mononuclear cells (PBMCs) and PCR was used to detect XMRV gag and env in 72 patients. Anti-XMRV antibodies were searched in sera of 62 patients by Western blot analysis. Attempts to detect XMRV antigens was made, using immunofluorescence with Gag anti-p30 antiserum on activated PBMC from 50 patients. Plasma viremia was measured by RT-PCR on 9 subjects. Finally, detection of infectious virus in 113 CFS subjects was made by co-culture of PHA+IL-2 activated PBMC with human LNCaP carcinoma cells, and by infecting the same susceptible cells with plasma, using a reverse transcriptase (RT) assay as a readout in both experiments. No detection of ...

2011-01-01

334

Identification of fatigue damage in cortical bone by diffraction enhanced imaging  

International Nuclear Information System (INIS)

In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.

2005-08-11

335

Fatigue lifetime and endurance-limit prediction for high-strength steels; Vorhersage der Lebensdauer und Dauerfestigkeit von hochfesten, durchhaerteten Staehlen  

Energy Technology Data Exchange (ETDEWEB)

Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle fatigue, crack initiation was most likely caused by inclusions like Titanium Carbon nitrides or Aluminium Oxides. A micro mechanical model for the crack initiation by inclusions was developed. Another model was developed to describe the influence of these inclusions on the lifetime. A weakest-link model, using the statistical distribution of inclusions and surface flaws, was used to describe the endurance limit. (orig.)

2002-07-01

336

Experimental characterisation and modelling of crack initiation and short crack propagation for fatigue life prediction of a #beta#-titanium alloy  

International Nuclear Information System (INIS)

Up to 90% of the life time of cyclically loaded components is determined by short crack initiation and propagation. This stage of the fatigue damage process is strongly influenced by microstructural features, e.g. grain boundaries and crystallographic grain orientation. Therefore LEFM can not be applied in a reasonable manner explaining the demand for a mechanism-related modelling method. The present study deals with mechanical testing and microstructural examinations applied to the relatively new #beta#-titanium alloy LCB. The results are used as data base to develop a new short crack model that is based on the model of Navarro and de los Rios. By using various techniques such as electron back-scattered diffraction and finite-element calculations the origin of crack initiation is revealed and the characteristics of crack propagation is determined. (orig.)

2000-02-24

337

Detecting retroviral sequences in chronic fatigue syndrome.  

Science.gov (United States)

XMRV or xenotropic murine leukemia virus-related retrovirus, a recently discovered retrovirus, has been linked to both prostate cancer and chronic fatigue syndrome (CFS). Recently, the teams of Drs. Shyh-Ching Lo and Harvey Alter discovered the presence of sequences closely related to XMRV in the blood of 86.5% of patients with CFS [1]. These findings are important because since the initial discovery of XMRV in CFS, several studies have failed to find XMRV in specimens collected from CFS patients. While the current study also did not find XMRV in CFS, Lo et al. did detect sequences that belong to polytropic mouse endogenous retroviruses (PMV), which share considerable similarity with XMRV. Criteria for future studies that will help bring greater clarity to the issue of retroviral sequences in CFS are proposed below. PMID:21994623

2010-11-03

338

Analysis of cerebrospinal fluid from chronic fatigue syndrome patients for multiple human ubiquitous viruses and xenotropic murine leukemia-related virus  

British Library Electronic Table of Contents (United Kingdom)

Abstract Recent reports showed many patients with chronic fatigue syndrome (CFS) harbor a retrovirus, xenotropic murine leukemia-related virus (XMRV), in blood; other studies could not replicate this finding. A useful next step would be to examine cerebrospinal fluid, because in some patients CFS is thought to be a brain disorder. Finding a microbe in the central nervous system would have greater significance than in blood because of the integrity of the blood-brain barrier. We examined cerebrospinal fluid from 43 CFS patients using polymerase chain reaction techniques, but did not find XMRV or multiple other common viruses, suggesting that exploration of other causes or pathogenetic mechanisms is warranted. Ann Neurol 2011;

2011-01-01

339

Visualization study on the static flow field around a straight-bladed vertical axis wind turbine  

Science.gov (United States)

Visual experiments based on the smoke wire way were carried out on a small model of Straight-blade Vertical Axis Wind Turbine (SB-VAWT) to invest the relationship between the static flow field characteristics and the rotor azimuth angle. The test rotor had 3 blades with NACA0018 aerofoil. The rotor diameter and blade chord were 0.3m and 0.07m, respectively. Visual photos of the static flow path lines in and around the rotor were obtained at every 5 degrees of the azimuth angle. Further, numerical computations of the static flow filed were also carried out for comparison with the same situation as the visual tests and the static torques at different azimuth angles were calculated. According to the results of visual tests and computations, the dependence of the starting performance on the azimuth angle was discussed. The solidity is an important factor affecting the starting performance of the SB-VAWT.

2009-12-01

340

The result of Alanine/ESR dosimetry at Wolsung unit 1  

International Nuclear Information System (INIS)

It needs accurate estimation of radiation level for verifying machinery and cable in Nuclear Power Plant. Therefore, in this study, we used ESR(Electron Spin Resonance) system for estimate dose of Alanine dosimeter. Alanine/ESR dosimetry, already known as a dosimetric method in medical and industrial field, was applied to estimate dose quantity at cable locations within a nuclear power plant as a part of equipment qualification program. Alanine/ESR dosimetry of absorbed dose range is 1 - 100 KGy. The alanine dosimeter is not significantly affected by temperature and fading is limited to 1% per year. The alanine dosimeters were fixed on the targeted cable or nearest position to measure dose quantity to get accurate value. Alanine dosimeters were scanned by commercially used two different ESR systems, e-scan and EMX series for alanine dosimeters. To estimate more accurate dose, two environmental correction factors, irradiation temperature and ...

2008-10-01

341

The impact of accretion disk winds on the X-ray spectrum of AGN: Part 1 - XSCORT  

CERN Document Server

(abridged) The accretion disk in AGN is expected to produce strong outflows, in particular a UV-line driven wind. Despite providing a good fit to the data, current spectral models of the X-ray spectrum of AGN observed through an accretion disk wind are ad-hoc in their treatment of the properties of the wind material. In order to address these limitations we adopt a numerical computation method that links a series of radiative transfer calculations, incorporating the effect of a global velocity field in a self-consistent manner (XSCORT). We present a series of example spectra from the XSCORT code that allow us to examine the shape of AGN X-ray spectra seen through a wind, for a range of velocity and density distributions, total column densities and initial ionization parameters. These detailed spectral models clearly show considerable complexity and structure that is strongly affected by all these factors. The presence of sharp features in the ...

2007-01-01

342

The effects of sacrificial coatings on hydrogen embrittlement and re-embrittlement of ultra high strength steels  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an investigation of electrodeposited Zn-14% Ni and aluminium-based SermeTel 1140/962 coatings as possible replacements for cadmium. Slow strain rate tests were performed to measure the extent of direct hydrogen embrittlement of a high strength steel substrate as a result of the coating process and of hydrogen re-embrittlement caused by coating corrosion. The level of re-embrittlement was shown to depend on both the electrochemical potential of the coating and its barrier properties. Zn-14% Ni coatings caused the most re-embrittlement as they had the most active potential and contained through-thickness defects which left the steel exposed to hydrogen uptake. The microstructure of the high strength steel was also shown to be an important factor affecting the extent of embrittlement. AerMet 100 steel was more resistant than 300M steel and this was attributed to the presence of reverted austenite surrounding the martensite ...

2008-04-15

343

The effect of welding parameters on hydrogen distribution in pipeline welds  

Energy Technology Data Exchange (ETDEWEB)

There is currently considerable interest in identifying and quantifying the effects of welding procedure parameters and steel composition factors on the risk of cracking in pipeline girth welds that may be experienced during winter construction. Although low ambient temperatures, that may be experienced during winter construction, are generally assumed to increase the risk of cracking there has been little work to quantify the effects and to suggest how welding procedures should be modified for winter conditions. The present work was undertaken to calculate the effects of changes in welding parameters on the thermal cycle and the diffusion of hydrogen for a typical pipeline girth weld. A simple analytical method and the finite element method (FEM) were used. Both methods gave similar results but the simple method was very sensitive to the value of heat transfer coefficient. The results showed that the relation between the hydrogen diffusion parameter (tau) and ...

1990-03-01

344

The Outermost Ejecta of Type Ia Supernovae  

CERN Document Server

The properties of the highest velocity ejecta of normal Type Ia supernovae (SNe Ia) are studied via models of very early optical spectra of 6 SNe. At epochs earlier than 1 week before maximum, SNe with a rapidly evolving Si II 6355 line velocity (HVG) have a larger photospheric velocity than SNe with a slowly evolving Si II 6355 line velocity (LVG). Since the two groups have comparable luminosities, the temperature at the photosphere is higher in LVG SNe. This explains the different overall spectral appearance of HVG and LVG SNe. However, the variation of the Ca II and Si II absorptions at the highest velocities (v >~ 20,000 km/s) suggests that additional factors, such as asphericity or different abundances in the progenitor white dwarf, affect the outermost layers. The C II 6578 line is marginally detected in 3 LVG SNe, suggesting that LVG undergo less intense burning. The carbon mass fraction is small, only less than 0.01 near the ...

2007-01-01

345

The Mechanical Properties of Alumina Films Formed by Plasma Deposition and by Ion Irradiation of Sapphire  

Energy Technology Data Exchange (ETDEWEB)

This paper examines the correlation between mechanical properties and the density, phase, and hydrogen content of deposited alumina layers, and compares them to those of sapphire and amorphous alumina synthesized through ion-beam irradiation of sapphire. Alumina films were deposited using electron beam evaporation of aluminum and co-bombardment with O{sub 2}{sup +} ions (30-230 eV) from an electron cyclotron resonance (ECR) plasma. The H content and phase were controlled by varying the deposition temperature and the ion energy. Sapphire was amorphized at 84 K by irradiation with Al and O ions (in stoichiometric ratio) to a defect level of 4 dpa in order to form an amorphous layer 370 nm thick. Nanoindentation was performed to determine the elastic modulus, yield strength and hardness of all materials. Sapphire and amorphized sapphire have a higher density and exhibit superior mechanical properties in comparison to the deposited alumina films. Density was determined to be the primary ...

1999-07-16

346

Test of electron beam technology on Savannah River Laboratory low-activity aqueous waste for destruction of benzene, benzene derivatives, and bacteria  

Energy Technology Data Exchange (ETDEWEB)

High energy radiation was studied as a means for destroying hazardous organic chemical wastes. Tests were conducted at bench scale with a {sup 60}Co source, and at full scale (387 l/min) with a 1.5 MV electron beam source. Bench scale tests for both benzene and phenol included 32 permutations of water quality factors. For some water qualities, as much as 99.99% of benzene or 90% of phenol were removed by 775 krads of {sup 60}Co irradiation. Full scale testing for destruction of benzene in a simulated waste-water mix showed loss of 97% of benzene following an 800 krad dose and 88% following a 500 krad dose. At these loss rates, approximately 5 Mrad of electron beam irradiation is required to reduce concentrations from 100 g/l to drinking water quality (5 {mu}g/l). Since many waste streams are also inhabited by bacterial populations which may affect filtering operations, the effect of irradiation on those populations was also studied. {sup 60}Co ...

1993-08-01

347

Terrestrial Planet Formation in Extra-Solar Planetary Systems  

CERN Document Server

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational collapse from micron-sized dust grains in the thin disk midplane. Second, planetesimals coalesce to form Moon- to Mars-sized protoplanets, also called "planetary embryos". Finally, full-sized terrestrial planets accrete from protoplanets and planetesimals. This final stage of accretion lasts about 10-100 Myr and is strongly affected by gravitational perturbations from any gas giant planets, which are constrained to form more quickly, during the 1-10 Myr lifetime of the gaseous component of the disk. It is during this final stage that the bulk compositions and volatile (e.g., water) contents of terrestrial planets are set, depending on their feeding zones and the amount of radial mixing that occurs. The main ...

2008-01-01

348

Study of ethanol-lysozyme interactions using neutron diffraction  

International Nuclear Information System (INIS)

Single-crystal neutron diffraction has been used to observe the interactions between deuterated ethanol (CD3CD2OH) and lysozyme in triclinic crystals of hen egg white lysozyme soaked in 25% (v/v) ethanol solutions. A total of 6047 observed reflections to a resolution of 2 A were used, and 13 possible ethanol sites were identified. The three highest occupied sites are close to locations for bromoethanol found in an earlier study by Yonath et al. [Yonath, A., Podjarny, A., Honig, B., Traub, W., Sielecki, A., Herzberg, O., and Moult, J. (1978) Biophys. Struct. Mech. 4, 27-36]. Structure refinements including a model for the flat solvent lead to a final crystallographic agreement factor of 0.097. Comparison with earlier neutron studies on triclinic lysozyme showed that neither the molecular structure nor the thermal motions were affected significantly by the ethanol. A detailed analysis of the ethanol-lysozyme contacts showed 61% of these to be ...

349

Spontaneous transfer of ganglioside GM_1 between phospholipid vesicles  

International Nuclear Information System (INIS)

The transfer kinetics of the negatively charged glycosphingolipid II"3-N-acetylneuraminosyl-gangliotetraosylceramide (GM_1) were investigated by monitoring tritiated GM_1 movement between donor and acceptor vesicles. After appropriate incubation times at 45 "0C, donor and acceptor vesicles were separated by molecular sieve chromatography. Donors were small unilamellar vesicles produced by sonication, whereas acceptors were large unilamellar vesicles produced by either fusion or ethanol injection. Initial GM_1 transfer to acceptors followed first-order kinetics with a half-time of about 40 h assuming that GM_1 is present in equal mole fractions in the exterior and interior surfaces of the donor vesicle bilayer and that no glycolipid flip-flop occurs. GM_1 net transfer was calculated relative to that of ["1"4C]cholesteryl oleate, which served as a nontransferable marker in the donor vesicles. Factors affecting the GM_1 interbilayer transfer rate ...

350

Simulation of traffic flow and control using conventional, fuzzy, and adaptive methods  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the graphical simulation of a traffic environment. The environment includes streets leading to an intersection, the intersection, vehicle traffic, and signal lights in the intersection controlled by different methods. The simulation allows for the study of parameters affecting traffic environments and the study of different control strategies for traffic signal lights, including conventional, fuzzy, and adaptive control methods. Realistic traffic environments are simulated including a cross intersection, with one or more lanes of traffic in each direction, with and without turn lanes. Vehicle traffic patterns are a mixture of cars going straight and making right or left turns. The free velocities of vehicles follow a normal distribution with a mean of the ``posted`` speed limit. Actual velocities depend on such factors as the proximity and velocity of surrounding traffic, approaches to intersections, and human response ...

1992-06-01

351

Shifting Discourses about Gender in Higher Education Enrolments: Retrieving Marginalised Voices  

Science.gov (United States)

In this paper the authors describe the ways poststructuralist discourses assisted us to reading and reflection on data collected as part of a traditional survey-style research study. The study--generated in response to widespread concern about falling male enrolment rates at the authors' regional university--focused upon factors affecting rural male school-leavers' decisions about postschool destinations, and upon these students' attitudes to higher education. In the paper that follows, the authors contest the dominant discourses that are frequently drawn on to explain differences in male and female higher education enrolment trends. They then focus upon the features of two of the more dominant stories that students told to explain this 'difference': stories about 'real men', and stories about the value of the 'practical' over the 'theoretical'. In addition, they present another story that draws upon girls' views of higher education. Together, ...

2003-12-01

352

Proceedings of the CERI 2006 natural gas conference : North American markets : fragile, handle with care  

International Nuclear Information System (INIS)

This conference was attended by decision makers throughout the supply chain in the natural gas industry who face the continuing challenges of changes in market mechanisms, pricing options, and transmission alternatives. It provided an opportunity to review issues affecting producers, shippers, marketers, and end-users in an environment of tight energy markets and high, inelastic demand. The constraints on adequate energy supplies are influenced by economic factors, current and future resources, materials, equipment, skilled labour, technology and financial capital. The 8 sessions of the conference dealt with the tight North American gas supply; the slow development of new supplies; resource access issues, including politics and supply security; the geopolitics of natural gas; impacts of high prices on the North American economy; energy industry impacts of high natural gas prices; domestic politics and high natural gas prices; and, radical ...

2006-03-13

353

Precooling techniques and applications for horticultural products - a review  

Energy Technology Data Exchange (ETDEWEB)

One of the most important factors affecting the postharvest life and quality of horticultural crops is temperature. Quality loss after harvest occurs as a result of physiological and biological processes, the rates of which are influenced primarily by product temperature. As the maintenance of market quality is of vital importance to the success of the horticultural industry, it is necessary not only to cool the product but to cool it as quickly as possible after harvest. The process of precooling is the removal of field heat which arrest the deteriorative and senescence processes so as to maintain a high level of quality that ensures customer satisfaction. This paper provides a critical review to portray precooling as an intricate part of temperature management and to highlight the importance of its utilisation for extending the shelf life and maintaining the quality of horticultural products with emphasis on cut flowers. Various different ...

2001-07-01

354

Possible preparation of wood-plastic materials based on unsaturated polyester resins and methyl metacrylate, by radiation and chemical methods in combination  

Energy Technology Data Exchange (ETDEWEB)

The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the impregnation mixture flowing out of the wood, and without forming ...

1982-04-01

355

Possible preparation of wood-plastic materials based on unsaturated polyester resins and methyl metacrylate, by radiation and chemical methods in combination  

International Nuclear Information System (INIS)

The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the impregnation mixture flowing out of the wood, and without forming ...

1982-01-01

356

Physics of electron beam therapy  

International Nuclear Information System (INIS)

A book has been written to introduce the physical aspects of the radiotherapy electron beam by presenting a summary of the developments in this field. The first chapter is a brief introduction to the technology of medical accelerators with emphasis on the electron beam production facilities. Chapter 2 describes the interaction processes at the atomic level once the electron beam enters the medium. Chapter 3 is concerned with the various properties of the electron beam purely from the clinical point of view. The electron beam algorithms and models for distribution calculations are covered in Chapter 4 with inclusion of age diffusion and multiple scattering approaches. The factors affecting the beam distribution in a patient, with inhomogeneities, surface irregularities, backscattering etc. are discussed in Chapter 5. The last two chapters are devoted to electron beam dosimetry including various dosimetric methods, specification and measurement ...

357

On the optimal environmental liability limit for marine oil transport  

Energy Technology Data Exchange (ETDEWEB)

Recent changes in the US liability regime for oil pollution damage have intensified a policy debate about environmental liability limits. Economic theory suggests that some type of limit may be needed under certain conditions, and that such a limit should be set so that the marginal social benefit and cost are equal. However, it is unclear how a liability limit may be determined specifically for tanker shipping in US waters. We first examine conditions under which corner solutions (no liability or unlimited liability) are desirable. We then formulate a model to determine a socially optimal liability limit for oil pollution damage in US waters when a non-zero, finite liability limit is desirable. The model captures the tradeoff between less expensive energy supply and more stringent protection of the marine environment. Numerical simulations illustrate the properties of the model and major factors affecting the public policy decision regarding a ...

1999-07-01

358

Obsidians and tektites: Natural analogues for water diffusion in nuclear waste glasses  

Energy Technology Data Exchange (ETDEWEB)

Projected scenarios for the proposed Yucca Mountain repository include significant periods of time when high relative humidity atmospheres will be present, thus the reaction processes of interest will include those known to occur under these conditions. The ideal natural analog for the proposed Yucca Mountain repository would consist of natural borosilicate glasses exposed to expected repository conditions for thousands of years; however, the prospects for identifying such an analog are remote, but an important caveat for using natural analog studies is to relate the reaction processes in the analog to those in the system of interest, rather than a strict comparison of the glass compositions. In lieu of this, identifying natural glasses that have reacted via reaction processes expected in the repository is the most attractive option. The goal of this study is to quantify molecular water diffusion in the natural analogs obsidian and tektites. Results from this study can be used in ...

1991-11-01

359

Motion analysis of parallelly connected FPSO unit and LNG carrier  

Energy Technology Data Exchange (ETDEWEB)

Nowadays, the floating production, storage, and offloading (FPSO) units are used to marginal oil fields and deep seas, because of mobility and reduced lead time from discovery to first production. One of the methods for offloading is to moor a tanker alongside the FPSO unit. In this case motion response of the system becomes highly complex, and will be affected by many factors such as hydrodynamic interaction and mechanical connections between the vessels. In this study, a quite general method is developed which has taken into account the hydrodynamic interaction as well as the effects of connectors and mooring lines, in motion response analysis of a multi-body floating system. For this purpose, 3-D source distribution method is applied for hydrodynamic analysis, and linear stiffness matrices are introduced to represent the effect of connectors and mooring lines on the motion equations. The method has been used for motion analysis of a ...

1996-12-31

360

Microcephaly  

International Nuclear Information System (INIS)

Among in uterus exposed A-bomb survivors, fetal week is the most important factor to clarify the effects of A-bomb radiation on developmental process of the fetal brain. The study population of in utero exposed A-bomb survivors has first been established in 1953 in Hiroshima and in 1955 in Nagasaki. According to the estimated DS86 uterus absorption doses, fetal absorption doses obtained from the uterus doses, and intelligence quotient. Various studies on brain damage, including microcephaly, have been undertaken among in uterus exposed A-bomb survivors. Brain development has been shown to be affected during the fetal weeks 8-15 and 16-25. A review of the literature has revealed that 80% of the children with mental retardation and 15 of 18 cases of microcephaly (83%) were exposed in utero during the fetal week 8-15. Among children exposed at the fetal weeks 8-15 and 16-25, average learning was significantly decreased. The incidence of spasm was ...

361

Measurement of swirling flow in direct injection diesel engine (Part 2). Effect of piston cavity diameter and top clearance volume  

Energy Technology Data Exchange (ETDEWEB)

Swirling flow in a direct injection diesel engine was measured by a laser doppler velocimeter. Piston cavity diameter and top clearance volume were changed as factors affecting swirling flow to study the distribution of swirling flow speed. When using the same intake port and changing the opening ratio of piston cavity, the distribution of swirling flow speed was different by the cavity during intake process but these agree just after opening intake valve and then become again different by cavity. When increasing top clearance and decreasing compression ratio, the axial symmetry of flow during commpression process increases. When changing piston cavity, and also when changing intake port, the mean swirling ratio in inside and outside areas of combustion chamber has common tendency to increase and decrease respectively. The mean swirling flow in the combustion chamber may be capable to be predicted by devising a model which can describe this ...

1989-05-31

362

Measurement of swirling flow in direct injection diesel engine (Part 1). Effect of intake port geometry and engine speed  

Energy Technology Data Exchange (ETDEWEB)

Swirling speed in a direct injection diesel engine was measured by a laser doppler velocimeter. Intake port geometry and engine speed were changed as factors affecting the swirling flow to study the distribution of swirling flow speed. The distribution of swirling flow speed changes complicatedly owing to axial nonsymmetry during intake process but becomes simple shape of axial symmetry during compression process after closing intake valve. But if this is assumed as the rigid swirl shape, the difference due to each intake port cannot be expressed but also large error may be possible to appear close to the cylinder wall. The distribution of swirling flow speed during compression process changes similarly, nearly proportinal to engine speed. But the similarity is higher at the middle period in compression process than at the end period in compression period. Axial distribution of local swirling ratio during compression process is nearly uniform. ...

1989-05-31

363

Measured impact of neighborhood tree cover on microclimate  

Energy Technology Data Exchange (ETDEWEB)

In this paper we present results of our investigation into the relationship between urban microclimate and the local density of tree cover as measured in Sacramento, California. These results were obtained through analysis of data collected in a two-month long monitoring program with automatic weather stations installed at 15 residential locations throughout the city. Measured wind speeds showed a highly negative correlation with respect to tree cover. Daily peak air temperatures showed significant variation often differing from site to site by 2 to 4{degrees}C ({approx}3.5 to 7{degrees}F). A complex interaction between several competing factors is discussed leading to the conclusion that additional tree cover may actually increase urban air temperatures on synoptically cool days. It is suggested that this does not have a significant adverse affect in terms of overall summer urban cooling load. This is supported by an integrated analysis of the ...

1992-08-01

364

Integrated interpretation of AE clusters and fracture system in Hijiori HDR artificial reservoir; Hijiori koon gantai jinko choryuso no AE cluster to kiretsu system ni kansuru togoteki kaishaku  

Energy Technology Data Exchange (ETDEWEB)

With regard to a fracture system in the Hijiori hot dry rock artificial reservoir, an attempt was made on an interpretation which integrates different data. Major factors that characterize development and performance of an artificial reservoir are composed of a fracture system in rocks, which acts as circulating water paths, a heat exchange face and a reservoir space. The system relates not only with crack density distribution, but also with cracks activated by water pressure fracturing, cracks generating acoustic emission (AE), and cracks working as major flow paths, all of which are characterized by having respective behaviors and roles. Characteristics are shown on AE cluster distribution, crack distribution, production zone and estimated stress fields. Mutual relationship among these elements was discussed based on the Coulomb`s theory. The most important paths are characterized by distribution of slippery cracks. Directions and appearance frequencies of the ...

1997-05-27

365

Influence of anthropogenic stress on fitness and behaviour of a key-species of estuarine ecosystems, the ragworm Nereis diversicolor  

Energy Technology Data Exchange (ETDEWEB)

Fitness, (biometric measurements, reproduction) and behaviour that are ecologically relevant biomarkers in assessing the quality of estuarine sediments were studied by comparing the responses of the polychaete worm Nereis diversicolor - a key species in estuaries - along a pollution gradient. Intersite differences were shown for all the measured parameters: size-weight relationships, energy reserves as glycogen and lipids, sexual maturation patterns, total number of oocytes per female, total and relative fecundity, burrowing behaviour. The physiological and behavioural status of N. diversicolor was consistently disturbed in the larger, most contaminated estuaries (Loire and Seine, Fr.) compared to reference sites (Bay of Bourgneuf, Goyen estuary, Fr.). Many classes of potentially toxic chemicals present in these estuaries most likely contribute to these impairments but food availability may act as a confounding factor, interfering with the potential impact of ...

2010-01-15

366

In Vitro Fracture of Human Cortical Bone: Local Fracture Criteria and Toughening Mechanisms  

Energy Technology Data Exchange (ETDEWEB)

A micro-mechanistic understanding of bone fracture that encompasses how cracks interact with the underlying microstructure and defines their local failure mode is lacking, despite extensive research on the response of bone to a variety of factors like aging, loading, and/or disease. Micro-mechanical models for fracture incorporating such local failure criteria have been widely developed for metallic and ceramic materials systems; however, few such deliberations have been undertaken for the fracture of bone. In fact, although the fracture event in mineralized tissues such as bone is commonly believed to be locally strain controlled, until recently there has been little experimental evidence to support this widely held belief. In the present study, a series of in vitro experiments involving a double-notch bend test geometry are performed in order to shed further light on the nature of the local cracking events that precede catastrophic fracture in bone and to define ...

2004-08-18

367

How the user views visual displays  

Energy Technology Data Exchange (ETDEWEB)

Most designers are not schooled in the area of human-interaction psychology and therefore tend to rely on the traditional ergonomic aspects of human factors when designing complex human-interactive workstations. Unfortunately, by ignoring the importance of the integration of the user interface at the psychophysiological level, the result can be ineffective use of a system leading to an inherently error- and failure-prone system. Therefore, to minimize failures in a human-interactive system, it is essential that designers understand how each user`s processing characteristics affect how the user gathers and processes information. By understanding the significant processing characteristics of the user, designers can implement practical and effective visual displays (or any other type of system) that are more desirable to all users. The material presented in this paper is based on a general study that involved users` perspective views of how visual ...

1995-12-31

368

Health-related quality of life following percutaneous coronary intervention: the impact of age on outcome at 1 year.  

Science.gov (United States)

This study was performed to assess the possibility that patient age may independently affect improvements in health-related quality of life following percutaneous coronary intervention. One hundred five patients undergoing elective percutaneous coronary intervention at a single tertiary referral center between January 10, 2001 and January 6, 2002 were enrolled and prospectively evaluated. Health-related quality of life was assessed before and 1 year following percutaneous coronary intervention using Short Form-12 and the Seattle Angina Questionnaire. For the purpose of analysis, patients were divided according to age (younger than 60, 60-70, and older than 70 years). One hundred patients (95%) completed both questionnaires. Baseline characteristics among the age groups were similar in terms of gender, cardiac risk factors, and procedural details. All health-related quality-of-life indices demonstrated improvements with at least four variables ...

369

Formation of A-15 filaments in Cu-base alloys  

International Nuclear Information System (INIS)

Brittleness and poor low-temperature thermal conductivity of A-15 compounds remain the major obstacles preventing the effective use of these superconductors in large-scale engineering applications. In order to circumvent these difficulties, a new type of ductile superconducting filamentary alloy has been developed recently by a simple metallurgical process which consists of melting the constituent elements and subsequent cold working and appropriate heat treatment. These superconducting materials are essentially Cu-base alloys containing a few percent of A-15 phase such as Nb_3Sn or V_3Ga which is in the form of fine filaments embedded in the Cu matrix. The emphasis of this work is on the formation of the A-15 phase in the Cu-base alloys and its correlation with superconducting properties such as transition temperature and critical current density. The formation of Nb_3Sn, Nb_3Al, V_3Si, and V_3Ga will serve as examples to illustrate the importance of some features in the phase ...

370

Focused ion-beam line profiles: A study of some factors affecting beam broadening  

Energy Technology Data Exchange (ETDEWEB)

The current--density profile of a focused ion beam (FIB) has a central peak accompanied by broader ``wings`` that, while unimportant in lithographic applications, can lead to unwanted effects during an implantation operation. The origin of the wings, and hence the best way to minimize them, is not clear and needs further study. We have measured the line profiles of several of the ions available in our FIB machine as a function of a number of variables, under ultrahigh vacuum (UHV) conditions. No effects are observed from changes in emission current or deliberate defocusing of the objective lens. There are some changes with beam aperture and/or current, but the biggest differences seem to be associated with a change of source type and hence, possibly, with a change in the source/extractor configuration or in the alloy and the emission process. The wing amplitudes are appreciably lower than many previously observed, and their profiles, at least for the lighter ions studied (Be{sup ++}, ...

1995-11-01

371

Focused ion-beam line profiles: A study of some factors affecting beam broadening  

International Nuclear Information System (INIS)

The current--density profile of a focused ion beam (FIB) has a central peak accompanied by broader ''wings'' that, while unimportant in lithographic applications, can lead to unwanted effects during an implantation operation. The origin of the wings, and hence the best way to minimize them, is not clear and needs further study. We have measured the line profiles of several of the ions available in our FIB machine as a function of a number of variables, under ultrahigh vacuum (UHV) conditions. No effects are observed from changes in emission current or deliberate defocusing of the objective lens. There are some changes with beam aperture and/or current, but the biggest differences seem to be associated with a change of source type and hence, possibly, with a change in the source/extractor configuration or in the alloy and the emission process. The wing amplitudes are appreciably lower than many previously observed, and their profiles, at least for the lighter ions studied (Be"+"+, Be"+, ...

372

Factors affecting actions of ethanol on GABA-activated chloride channels  

International Nuclear Information System (INIS)

Effects of ethanol in vitro on membrane vesicles were evaluated by monitoring "3"6Cl"- influx. Different assay parameters were tested to determine increased or decreased action of ethanol on GABA-activated chloride channels. The ability of 30 mM ethanol to augment "3"6Cl"- flux was seen at 0 degree C, in the absence of GABA, and at 34 degree C in the presence of GABA, using two different assay procedures. Picrotoxin blocked the direct effects of ethanol suggesting GABA_a involvement. Endogenous GABA in the medium surrounding the microsacs was assayed at different temperatures both in the presence and absence of GABA and ethanol. The direct effect of ethanol did not appear to involve the action of endogenous GABA. In addition to temperature effects on the assay, time of membrane storage also influenced ethanol action. Microsacs stored on ice for 2 hours or more lost their ability to respond to ethanol but not to GABA, pentobarbital or flunitrazepam. When these drugs were tested on ...

373

Experimental investigations on the characteristics of melting processes of stearic acid in an annulus and its thermal conductivity enhancement by fins  

Energy Technology Data Exchange (ETDEWEB)

An experimental rig was set up to study the performance of a thermal storage unit using stearic acid as the heat storage medium. The unit mainly consists of an electrical heating rod and an outer tube, and the space between is an annulus that is filled with stearic acid. The thermal performance of the unit is measured, and the heat transfer characteristics of the melting processes of stearic acid are studied under different heat flux conditions to determine the influence of heat flux on the melting processes. A new type of fin is designed and fixed to the electrical heating rod to enhance the thermal response of the stearic acid. The experimental results show that the fin can improve the heat transfer of the melting process of the thermal storage unit greatly. The equivalent thermal conductivity of the PCM can be augmented by a factor up to 3. The analysis of the experimental results shows that the enhancement mechanism of the fin is attributed to its ability to ...

2005-04-01

374

Experimental investigations on the characteristics of melting processes of stearic acid in an annulus and its thermal conductivity enhancement by fins  

Energy Technology Data Exchange (ETDEWEB)

An experimental rig was set up to study the performance of a thermal storage unit using stearic acid as the heat storage medium. The unit mainly consists of an electrical heating rod and an outer tube, and the space between is an annulus that is filled with stearic acid. The thermal performance of the unit is measured, and the heat transfer characteristics of the melting processes of stearic acid are studied under different heat flux conditions to determine the influence of heat flux on the melting processes. A new type of fin is designed and fixed to the electrical heating rod to enhance the thermal response of the stearic acid. The experimental results show that the fin can improve the heat transfer of the melting process of the thermal storage unit greatly. The equivalent thermal conductivity of the PCM can be augmented by a factor up to 3. The analysis of the experimental results shows that the enhancement mechanism of the fin is attributed to its ability to ...

2005-04-01

375

Evaluation of spark ignition of a gas cooktop flame  

Science.gov (United States)

One of the energy-saving devices used on gas cooking appliances to eliminate the standing pilot is a spark ignition system. For safety, an ignition system must start promptly and be active whenever flowing gas is not ignited. To minimize noise and nuisance shock hazard, ignition must occur quickly and the sparking must be stopped as soon as ignition occurs and remain off as long as the flame is present. To accomplish both of these requirements, ignition systems have been devised which use the electrical current rectification property of a flame to sense it. These systems spark whenever the gas valve is on and a flame is not present. The factors affecting the performance of a spark ignition system are numerous, complex, and transient. All of these properties make quantification of performance difficult. A system is described which can evaluate the overall performance of ignition systems over significant periods of time and varieties of operating ...

1996-01-01

376

Efficient mitigation strategies for epidemics in rural regions  

CERN Document Server

Containing an epidemic at its origin is the most desirable mitigation. Epidemics have often originated in rural areas, with rural communities among the first affected. Disease dynamics in rural regions have received limited attention, and results of general studies cannot be directly applied since population densities and human mobility factors are very different in rural regions from those in cities. We create a network model of a rural community in Kansas, USA, by collecting data on the contact patterns and computing rates of contact among a sampled population. We model the impact of different mitigation strategies detecting closely connected groups of people and frequently visited locations. Within those groups and locations, we compare the effectiveness of random and targeted vaccinations using a Susceptible-Exposed-Infected-Recovered compartmental model on the contact network. Our simulations show that the targeted vaccinations of only 10% ...

2010-01-01

377

Effect on heat-transfer augmentation by channel width in a sinusoidal wave channel  

Energy Technology Data Exchange (ETDEWEB)

In the development of high performance heat transfer surface on a compact heat exchanger, it was clarified that how reattachment point heat transfer and fluid flow are affected by channel width, at the same time, an evaluation of heat transfer performance and an investigation of optimum channel width were carried out. The channel system used in the experiment is as follows; (1) blow-off type with rectangular section channel, (2) span length of 200 mm, (3) wave length (pitch) of 80 mm, and (4) channel length of 12.5 wave length. The channel Reynolds number was set at about 10/sup 4/ which is relatively higher than the current studies. The results of the experiment were summarized as follows. (1) The channel width H has relevance to the phase difference between the fluid flow in cone portion of main stream and wave shape, the flow patterns are divided roughly into three types. These boundaries exist at P/H 3.0 and 1.5 (P: pitch, H: width). (2) The reattachment point ...

1988-06-25

378

Effect of percutaneous transluminal angioplasty in insufficiency of arteriovenous fistula for hemodialysis  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the effectiveness of percutaneous transluminal angioplasty(PTA) and to determine the factors affecting the long-term patency rate in the management of insufficient hemodialytic arteriovenous fistula(AVF). Forty-nine cases of insufficient hemodialytic AVF were treated in 44 patients(native AVF:20, graft AVF:29, M:17, F:27, Age:22-70 years). In 28 thrombus patients, thrombolysis was performed with urokinase, and was followed by PTA. The initial success rate and complications of PTA were evaluated. According to the site and length of the stenosis, type and age of the AVF, the presence or abscence of thrombus, a history of diabetic mellitus, the patient's age, and the duration of renal failure, patency rates were compared within each subgroup using the Kaplan-Meier logrank test. The initial success rate of PTA for insufficient hemodialytic AVF was 88%(43/49), the patency rate of PTA was 67% at 6 months, and 50% at 12 months. ...

1999-06-01

379

Economic analysis of fuel recycle  

International Nuclear Information System (INIS)

Economic analysis was performed at KAERI with the assistance of US DOE to compare single reactor fuel cycle costs for a once-through option and a thermal recycle option to operate 1 GWe of a PWR plant for its lifetime. A reference fuel cycle cost was first calculated for each option with best estimated reference input data. Then a sensitivity analysis was performed changing each single value of such fuel cycle component costs as yellow cake price, enrichment charges, spent fuel storage cost, reprocessing cost, spent fuel disposal cost and reprocessing waste disposal cost. Savings due to thermal recycle in requirements of uranium, conversion, and enrichment were examined using formulas suggested by US DOE, while MOX fabrication penalty was accounted for. As a result of the reference fuel cycle cost analysis, it is calculated that the thermal recycle option is marginally more economical than the once-through option. The major factors affecting ...

1985-05-19

380

Development of generalized boiling transition analysis methodology applicable to a wide variety of BWR-type fuel bundle geometry -Mater plan and status of first year-  

Energy Technology Data Exchange (ETDEWEB)

As a three-year joint university-industry effort, development of a generalized boiling transition analysis method has been started in 2002 aiming at enhanced capabilities of subchannel analysis for a wide variety of BWR-type fuel bundle geometry from ordinary BWR to tight lattice fuel bundles. For this purpose, five dominant factors affecting boiling transition phenomena have been identified on which our efforts of experimentation and numerical analyses are focused. In this report, as the first-year achievement, we will describe a master plan of the development and contents for experimental approaches to construct thermal-hydraulic databases. The databases will be utilized for the developments of constitutive equations to describe the basic characteristics of the elementary processes. The planned experiments are divided into two groups. One is air-water experiments at atmospheric pressure, and the other is steam-water experiments up to 1 MPa. ...

2003-07-01

381

Development of generalized boiling transition analysis methodology applicable to a wide variety of BWR-type fuel bundle geometry -Mater plan and status of first year-  

International Nuclear Information System (INIS)

As a three-year joint university-industry effort, development of a generalized boiling transition analysis method has been started in 2002 aiming at enhanced capabilities of subchannel analysis for a wide variety of BWR-type fuel bundle geometry from ordinary BWR to tight lattice fuel bundles. For this purpose, five dominant factors affecting boiling transition phenomena have been identified on which our efforts of experimentation and numerical analyses are focused. In this report, as the first-year achievement, we will describe a master plan of the development and contents for experimental approaches to construct thermal-hydraulic databases. The databases will be utilized for the developments of constitutive equations to describe the basic characteristics of the elementary processes. The planned experiments are divided into two groups. One is air-water experiments at atmospheric pressure, and the other is steam-water experiments up to 1 MPa. ...

2003-10-05

382

Coolant rate distribution in horizontal steam generator under natural circulation  

International Nuclear Information System (INIS)

The interrelations between the factors causing the main effects on the primary circuit coolant flow rate distribution in the horizontal steam generator pipes in reactor facilities with the WWER type reactors under the modes with natural circulation are discussed. The criterion showing the presence or absence of coolant circulation reversal in bottom rows of the steam generator pipes is obtained. It is shown that large hydraulic non-uniformity in steam generator pipes operating in parallel under coolant natural circulation leads to decreasing the heat transfer surface efficiency under reactor facility emergency cooling, restricts its servicing capabilities. The circulation reverse in steam generator pipes under coolant natural circulation mode can give unfavourable effect on separate structural elements of the steam generators and as a result it can cause additional temperature strains in metal. The conclusion on provisions for improving the conditions for coolant ...

1997-09-01

383

Computational fluid dynamics study of the effects of the re-entrant lip shape and toroidal radii of piston bowl on a high-speed direct-injection diesel engine's performance and emissions  

Energy Technology Data Exchange (ETDEWEB)

The piston bowl design is one of the most important factors that affect the air-fuel mixing and the subsequent combustion and pollutant formation processes in a direct-injection diesel engine. The bowl geometry and dimensions, such as the pip region, bowl lip area, and toroidal radius, are all known to have an effect on the in-cylinder mixing and combustion process. In order to understand better the effect of re-entrant geometry, three piston bowls with different toroidal radii and lip shapes were investigated using computational fluid dynamics engine modelling. KIVA3V with improved submodels was used to model the in-cylinder flows and combustion process, and it was validated on a high-speed direct-injection engine with a second-generation common-rail fuel injection system. The engine's performance, in-cylinder flow, and combustion, and emission characteristics were analysed at maximum power and maximum torque conditions and at ...

2005-08-15

384

Comparison of radon exposure assessment results: {sup 210}Po surface activity on glass objects vs. contemporary air radon concentration  

Energy Technology Data Exchange (ETDEWEB)

Radon exposure assessment in case-control studies on radon and lung cancer is generally based on contemporary radon concentration measurements, which can be affected by significant changes in the building structures or in living habits. Another method to estimate the radon exposure of the subjects is the recently developed retrospective dosimetry technique based on the {sup 210}Po surface activity from glass objects. In order to compare the results obtained by the two methods, a study has been carried out in a sample of 26 dwellings in Rome, with radon concentration values ranging from 28 to 623 Bq m{sup -3}. Retrospective detectors based on CR-39 and LR 115 were exposed on 50 glass objects in bedrooms and living rooms. The correlation factor between the two sets of data, after removing six extreme values, is 0.67, which is similar to results obtained in other validation studies of similar sample size. The correlation increases to 0.83 if the ...

2003-06-01

385

Celastrol regulates innate immunity response via NF-@kB and Hsp70 in human retinal pigment epithelial cells  

British Library Electronic Table of Contents (United Kingdom)

Elevated nuclear factor kappa B (NF-@kB) activity and interleukin-6 (IL-6) secretion participates in the pathology of several age and inflammatory-related diseases, including age-related macular degeneration (AMD), in which retinal pigment epithelial cells are the key target. Recent findings reveal that heat shock protein 70 (Hsp70) may affect regulation of NF-@kB. In the current study, effects of Hsp70 expression on NF-@kB RelA/p65 activity were evaluated in human retinal pigment epithelial cells (ARPE-19) by using celastrol, a novel anti-inflammatory compound. Anti-inflammatory properties of celastrol were determined by measuring expression levels of IL-6 and endogenous NF-@kB levels during lipopolysaccharide (LPS) exposure by using enzyme-linked immunosorbent assays (ELISA). Cell viabil...

2011-01-01

386

Benchmarking of refinery emissions performance : Executive summary  

International Nuclear Information System (INIS)

This study was undertaken to collect emissions performance data for Canadian and comparable American refineries. The objective was to examine parameters that affect refinery air emissions performance and develop methods or correlations to normalize emissions performance. Another objective was to correlate and compare the performance of Canadian refineries to comparable American refineries. For the purpose of this study, benchmarking involved the determination of levels of emission performance that are being achieved for generic groups of facilities. A total of 20 facilities were included in the benchmarking analysis, and 74 American refinery emission correlations were developed. The recommended benchmarks, and the application of those correlations for comparison between Canadian and American refinery performance, were discussed. The benchmarks were: sulfur oxides, nitrogen oxides, carbon monoxide, particulate, volatile organic compounds, ammonia and benzene. For ...

2003-01-01

387

An examination of the ignition delay period in gas-fueled diesel engines  

Energy Technology Data Exchange (ETDEWEB)

Changes in the physical and chemical processes during the ignition delay period of a gas-fueled diesel engine (dual-fuel engine) due to the increased admission of the gaseous fuels and diluents are examined. The extension to the chemical aspects of the ignition delay with the added gaseous fuels and the diluents into the cylinder charge is evaluated using detailed reaction kinetics for the oxidation of dual-fuel mixtures at an adiabatic constant volume process while employing n-heptane as a representative of the main components of the diesel fuel. In the examination of the physical aspects of the delay period, the relative contributions of changes in charge temperature, pressure, physical properties, pre-ignition energy release, heat transfer, and the residual gas effects due to the admission of the gaseous fuels are discussed and evaluated. It is shown that the introduction of gaseous fuels and diluents into the diesel engine can substantially affect both the ...

1998-01-01

388

A one-pot synthetic approach to prepare palladium nanoparticles embedded hierarchically porous TiO2 hollow spheres for hydrogen peroxide sensing  

Science.gov (United States)

A simple one-step method to fabricate hierarchically porous TiO2/Pd composite hollow spheres without any template was developed by using solvothermal treatment. Pd nanoparticles (2-5 nm) were well dispersed in the mesopores of the TiO2 hollow spheres via in-situ reduction. In our experiment, polyvinylpyrrolidone played an important role in the synthetic process as the reducing agent and the connective material between TiO2 and Pd nanoparticles. HF species generated from solvothermal reaction leaded to the formation of TiO2 hollow spheres and Ostwald ripening was another main factor that affected the size and structure of the hollow spheres. The as-prepared TiO2/Pd composite hollow spheres exhibited high electrocatalytic activity towards the reduction of H2O2. The sensitivity was about 226.72 ?A mM-1 cm-2 with a detection limit of 3.81 ?M at a signal-to-noise ratio of 3. These results made the hierarchically porous TiO2/Pd composite a promising ...

2010-10-01

389

Effects of Acetate Competition, pH and Soil Structure on the Rates and Pathways of Methane Formation in Tropical Rain Forest Soils  

Science.gov (United States)

The C isotopic composition of CH4 emissions are strongly influenced by the pathway of CH4 formation. Contrary to data from other freshwater systems, soil gas and surface flux measurements made in the tropical rain forests of Puerto Rico strongly suggest that CH4 produced in these environments was derived from CO2 reduction, rather than from acetate consumption. This study explored the effects of bacterial competition for acetate, pH, and soil structure on the pathways of CH4 formation in tropical rain forest soils. Our goal was to test two principal hypotheses: (1) ferric iron-reducing bacteria out-competed methanogens for acetate, resulting in greater CO2 reduction rather than aceticlastic methanogenesis, and (2) the low pH of tropical rain forest soils favors CO2 reduction rather than aceticlastic methanogenesis. In addition, this study also investigated the effect of destroying soil aggregate structure on the pathways and rates of CH4 production. Ferric iron-reducing bacteria ...

2004-12-01

390

Submarine tsunamigenic landslides at Stromboli Volcano: characterization and estimation of recurrence time  

Science.gov (United States)

Seafloor mapping and morphometric analysis of landslide scars can provide useful insights for marine geo-hazard assessment, as demonstrated by several studies performed on different geological settings. The availability of high-resolution multibeam bathymetry and long-range side scan sonar data on the submarine portions of Stromboli Volcano allow us to map and characterize the main mass-wasting features that affect, on the whole, about the 90% of its submarine extension. In particular, two main kinds of tsunamigenic landslides have been recognized and analyzed. Large-scale sector collapses (Fig. 1) are catastrophic events that mobilize 1-2 cubic kilometers of material, generating huge tsunami waves that may affect Stromboli and propagate in surrounding areas; related hazard is not very high, as they show recurrence periods of some (or more) thousand years. Conversely, medium-scale landslides are more hazardous, as they occur at higher frequency ...

2010-12-01

391

Population dynamics of dechlorinators and factors affecting the level and products of PCB dechlorination in sediments  

Energy Technology Data Exchange (ETDEWEB)

Microbial dechlorination of polychlorinated biphenyls (PCBs) often stops although a significant number of removable chlorines remain. To determine the reason for the cessation, we investigated the limitation of organic carbon, PCB bioavailability, and inhibition by metabolic products. Enrichment with carbon sources did not induce additional chlorination, indicating the plateau was not due to depletion of organic carbon. The bioavailability was not limiting, since a subcritical micelle concentration of the surfactant, which enhanced desorption without inhibiting dechlorinating microorganisms, failed to lower the plateau. Neither was it due to accumulation of metabolites, since no additional dechlorination was detected when plateau sediments were incubated with fresh medium. Similarly, dechlorination was not inhibited in freshly spiked sediment slurries. Dechlorination ended up at the same level with nearly identical congener profiles, regardless of treatment. These results indicate that ...

1996-12-31

392

Magnetic resonance imaging of cerebral anomalies in subjects with resistance to thyroid hormone  

Energy Technology Data Exchange (ETDEWEB)

Resistance to thyroid hormone (RTH) is an autosomal dominant disease caused by mutations in the human thyroid receptor beta gene on chromosome 3. Individuals with RTH have an increased incidence of attention deficit hyperactivity disorder (ADHD). The purpose of this study was to search for developmental brain malformations associated with RTH. Forty-three subjects (20 affected males [AM], 23 affected females [AF]) with resistance to thyroid hormone and 32 unaffected first degree relatives (18 unaffected males [UM], 14 unaffected females [UF]) underwent MRI brain scans with a volumetric acquisition that provided 90 contiguous 2 mm thick sagittal images. Films of six contiguous images beginning at a standard sagittal position lateral to the insula were analyzed by an investigator who was blind with respect to subject characteristics. The presence of extra or missing gyri in the parietal bank of the Sylvian fissure (multimodal association cortex) ...

1995-06-19

393

Incident angle modifiers for flat-plate solar collectors: analysis of measurement and calculation procedures  

Energy Technology Data Exchange (ETDEWEB)

Existing test procedures for measuring and rating thermal performance require the determination of the angular response of collectors in order to account for nonnormal incident beam irradiance. Angular response measurements for four different types of collectors, each type tested by three different laboratories, are presented and analyzed. Substantial differences, both within and between laboratories, are reported for the same type collectors. An analysis of the measurement procedure shows that experimentally determined angular response parameters are subject to relatively large uncertainties. The problem results to a large extent from measuring collector efficiencies at non-normal incident angles where measurement uncertainty is of the same order of magnitude as the efficiency reduction attributable to these off-normal angles. Other factors which can affect angular response measurements and the method of correlating results are also discussed. ...

1982-11-01

394

Consideration on relationship between radon concentration in soil gas and distribution of hot springs. Radon nodo tokusei to onsen no bunpu tono kankei ni kansuru ichikosatsu  

Energy Technology Data Exchange (ETDEWEB)

This paper describes considerations given on factors affecting radon concentrations, and the radon concentration measurements in hot springs distributed in the northern part of Kumamoto Prefecture. As a result of analyzing radon concentration attenuation in the vertically upward direction using a diffusion equation, it was revealed that radon carrier gas velocities affect strongly the radon concentration, and the [sup 220]Rn source is limited to a very shallow bed below the ground surface. An inclined face was prepared against the [sup 222]Rn decay constant distribution using an inclined face analyzing method. The [sup 222]Rn concentration direction based on this inclined face harmonized approximately well with the hot spring distribution direction. Base rocks that well up hot springs were inferred to be granite from the concentration distribution and pH of chemical components in each hot spring. As a result of surveying ...

1993-02-01

395

Comparison of Ceramic, Metal and Polymer Crevice Formers on the Crevice Corrosopn Behavior of Ni-CR-Mo Alloy C22  

Energy Technology Data Exchange (ETDEWEB)

A necessary condition for crevice corrosion is that a crevice former create a sufficiently tight, restricted geometry on the metal surface to support the development of critical crevice chemistry. Crevice corrosion is affected by the crevice geometry (tightness) and the properties of the crevice former. The objective of this study is to determine the effect of the crevice former material on the evolution of localized corrosion-damage. A standard crevice corrosion test method is modified by (a) the use of ceramic, metal or polymer materials as the crevice former and (b) the variation of size and shape of the crevice. This study focuses on the post initiation stage of crevice corrosion and addresses factors that may limit the initiation of localized corrosion and also slow or stop the continued propagation of corrosion. Controlled crevice corrosion tests are performed under aggressive, accelerated conditions on Ni-Cr-Mo alloy C-22 and other ...

2006-05-08

396

Age and body mass index-dependent relationship between correction of iron deficiency anemia and insulin resistance in non-diabetic premenopausal women  

International Nuclear Information System (INIS)

No prospective studies have evaluated the effects of correction of iron deficiency anemia on insulin resistance in non-diabetic premenopausal women with iron deficiency anemia. All patients were treated with oral iron preparations. Insulin resistance was calculated with the Homeostasis Model Assessment formula. All patients were dichotomized by the median for age and BMI to assess how the relationship between iron deficiency anemia and insulin resistance was affected by the age and BMI. Although the fasting glucose levels did not change meaningfully, statistically significant decreases were found in fasting insulin levels following anemia treatment both in the younger age (<40 years) (P=0.40) women and in the low BMI (27 kg/m) (P=0.22) subgroups but not in the older age (>= 40 years) and the high BMI (>-27Kg/m) subgroups. Post-treatment fasting insulin levels were positively correlated both with BMI (r=0.386, P=0.004) and post-treatment hemoglobin levels. ...

397

Phase I Report: DARPA Exoskeleton Program  

Science.gov (United States)

The Defense Advanced Research Projects Agency (DARPA) inaugurated a program addressing research and development for an Exoskeleton for Human Performance Augmentation in FY!2001. A team consisting of Oak Ridge National Laboratory, the prime contractor, AeroVironment, Inc., the Army Research Laboratory, the University of Minnesota, and the Virginia Polytechnic Institute has recently completed an 18-month Phase I effort in support of this DARPA program. The Phase I effort focused on the development and proof-of-concept demonstrations for key enabling technologies, laying the foundation for subsequently building and demonstrating a prototype exoskeleton. The overall approach was driven by the need to optimize energy efficiency while providing a system that augmented the operator in as transparent manner as possible (non-impeding). These needs led to the evolution of two key distinguishing features of this team's approach. The first is the ''no knee ...

2004-01-21

399

Application of dose factors for decay chains  

International Nuclear Information System (INIS)

... dose rates inhalation iodine 134 krypton 88 nuclear decay quality factor

400

Tensile strength of eutectic, directionally solidified alloys based on the Co-Cr-C-system  

International Nuclear Information System (INIS)

The influence of various alloy elements on tensile strength of the eutectic, directionally solidified superalloy 73 C was determined. The tensile properties of the base alloy has been increased by Al, Y and C as alloying elements, while Ni and Ti showed a decreasing effect (alloy softening). However, ductility and thermo-fatigue behaviour had been influenced in a positive way by these elements. The specific meachanism caused by the different elements are discussed. (orig.).

1981-01-01

401

Tailored airfoils for vertical axis wind turbines  

Energy Technology Data Exchange (ETDEWEB)

The evolution of a family of airfoil sections designed to be used as blade elements of a vertical axis wind turbine (VAWT) is described. This evolution consists of extensive computer simulation, wind tunnel testing and field testing. The process reveals that significant reductions in system costs-of-energy and increases in fatigue lifetime may be expected for VAWT systems using these blade elements.

1984-11-01

402

Properties of Beta-C trademark (Ti-3Al-8V-6Cr-4Mo-4Zr)  

International Nuclear Information System (INIS)

Beta C trademark, a metastable beta titanium alloy developed by RMI Titanium Company, continues to be used in new applications due to its excellent mechanical properties and resistance to corrosion. New data in this paper include mechanical properties in large sections, cold drawn bar and welds. Fatigue crack growth and corrosion data are added to supplement previously published data.

1993-02-21

403

Plasma nitriding improvements of fatigue properties of nodular cast iron crankshafts  

Energy Technology Data Exchange (ETDEWEB)

Crankshafts of the pearlitic-sorbitic nodular cast iron type JUS NL.80 (similar to DIN GGG-80) heat treated to get a tensile strength of 820-900 GPa (i.e. a Vickers hardness of 268-295 HV) were plasma and ammonia gas nitrided. The glow discharge plasma nitriding was performed for 20 h at about 500degC in a gas mixture of 55% N{sub 2} and 45% H{sub 2}. The gas nitriding was performed for 28 h at 510degC in the ammonia gas. Evaluation of the nitrided surfaces was conducted by optical microscopy, X-ray diffractometry and microhardness measurements. Journal and crank pin dimensions and surface roughness were measured both before and after nitriding. Bending fatigue testing of crankshafts was performed using a fatigue testing rig. The fatigue limit was evaluated at 5.0x10{sup 6} cycles. The fractures happened at the transition radius of the journal with cracks starting beneath the nitrided layer. It was found that the nitrided ...

1991-07-07

404

Plan-view transmission electron microscopy of crack tips in bulk materials  

Energy Technology Data Exchange (ETDEWEB)

A focused ion beam (FIB) system has been applied to prepare a thin foil specimen of Si, MgO and alumina which contained cracks in the plan of foil. It was possible to observe a much larger area at and near a crack tip than has been hitherto possible. FIB was also applied to observation of microstructure near a crack tip evolved during severe rolling contact fatigue in a steel.

1996-12-01

405

Formation of interphase layers in titanium alloys under repeated loading  

International Nuclear Information System (INIS)

Cyclic strength of #alpha#+#beta#-titanium alloy BT3-1 is studied under load frequencies of 33 and 300 Hz. The increase in the cyclic strength with growing frequency is caused by formation of FCC interphase layers of titanium hydrides. Their formation is one of possible ways of raising the fatigue strength of titanium alloys. Peculiarities of FCC interlayer formation in #alpha#+#beta# phases under loading frequency variation are revealed.

406

Calculation of the cyclic fatigue strength of notched and multiaxially loaded specimens of the bainitic steel 100Cr6; Berechnung der Wechselfestigkeit von gekerbten und mehrachsig beanspruchten Proben des Stahls 100Cr6 im bainitischen Zustand  

Energy Technology Data Exchange (ETDEWEB)

High-strength, fully hardening steels are used in general for applications involving severe wear and frequently also additional cyclic stress. For the latter condition, the available information and experimental data for component dimensioning are insufficient. Work reported in the dissertation therefore was intended to establish experimental information showing the performance of the bainitic roller bearing steel 100Cr6 and deducing rules of applicability to components, of the fatigue strength data obtained with the specimens. Various models for calculating the fatigue strength are presented together with their application to the steel 100Cr6. The results show that the weakest link model is a good concept for fatigue strength calculation, taking into account multiaxial loading. (orig/CB) [Deutsch] Hochfeste durchhaertende Staehle unterliegen in der Regel hohen Verschleissbeanspruchungen und werden darueber hinaus oftmals ...

1998-12-01

407

Case studies: Experience in China [Factors affecting public and political acceptance for the implementation of geological disposal  

International Nuclear Information System (INIS)

China operates 10 nuclear power reactors and has 5 more under construction. A large extension of nuclear power is expected by 2020. Nuclear generated electricity accounts for 2% of the total electric power generation. The Chinese policy is to have spent fuel reprocessed in China. So, final disposal include vitrified waste and some CANDU spent fuel for direct disposal. There is a legal framework in place in China to manage HLW. The China Atomic Energy Authority (CAEA) has the responsibility for setting policy on HLW disposal and implementing the disposal programme, while the National Nuclear Safety Administration (NNSA) and the State Environment Protection Agency (SEPA) are the regulatory bodies, which are responsible for licensing and reviewing of environment impact assessment report. The China National Nuclear Corporation (CNNC) is considered to be the actual implementer, conducting the major activities for HLW management. In the 1980's, China started generic research and development ...

2007-10-01

408

Vitamins B2 and B6 and genetic polymorphisms related to one-carbon metabolism as risk factors for gastric adenocarcinoma in the European prospective investigation into cancer and nutrition  

DEFF Research Database (Denmark)

B vitamins and polymorphisms in genes coding for enzymes involved in one-carbon metabolism may affect DNA synthesis and methylation and thereby be implicated in carcinogenesis. Previous data on vitamins B2 and B6 and genetic polymorphisms other than those involving MTHFR as risk factors for gastric cancer (GC) are sparse and inconsistent. In this case-control study nested within the European Prospective Investigation into Cancer and Nutrition cohort, cases (n = 235) and controls (n = 601) were matched for study center, age, sex, and time of blood sampling. B2 and B6 species were measured in plasma, and the sum of riboflavin and flavin mononucleotide was used as the main exposure variable for vitamin B2 status, whereas the sum of pyridoxal 5'-phosphate, pyridoxal, and 4-pyridoxic acid was used to define vitamin B6 status. In addition, we determined eight polymorphisms related to one-carbon metabolism. Relative risks for GC risk were calculated ...

2010-01-01

409

Textured silicon nitride: processing and anisotropic properties  

International Nuclear Information System (INIS)

Textured silicon nitride (Si_3N_4) has been intensively studied over the past 15 years because of its use for achieving its superthermal and mechanical properties. In this review we present the fundamental aspects of the processing and anisotropic properties of textured Si_3N_4, with emphasis on the anisotropic and abnormal grain growth of #beta#-Si_3N_4, texture structure and texture analysis, processing methods and anisotropic properties. On the basis of the texturing mechanisms, the processing methods described in this article have been classified into two types: hot-working (HW) and templated grain growth (TGG). The HW method includes the hot-pressing, hot-forging and sinter-forging techniques, and the TGG method includes the cold-pressing, extrusion, tape-casting and strong magnetic field alignment techniques for #beta#-Si_3N_4 seed crystals. Each processing technique is thoroughly discussed in terms of theoretical models and experimental data, including the texturing mechanisms ...

2008-07-01

410

Synthesis, structural characterization, and performance evaluation of resorcinol-formaldehyde (R-F) ion-exchange resin  

International Nuclear Information System (INIS)

The 177 underground storage tanks at the DOE's Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. ...

2004-09-10

411

Surface-water-resources information for the Ho-Chunk Nation lands and vicinity, Wisconsin  

Science.gov (United States)

The Ho-Chunk Nation is interested in documenting water-quality conditions in streams adjacent to their Reservation lands in Wisconsin and developing management plans to protect these water resources. The Nation uses these waterways for recreation and as a source for food, and therefore, is dedicated to maintaining and restoring their quality. Ho-Chunk lands encompass more than 10,000 acres ranging primarily over 17 counties in Wisconsin. The study areas for this report include streams adjacent to Ho-Chunk Nation residential lands: Potch-Hah-Chee, Sandpillow, Mission, Bluewing, Chakh Hah Chee, Winnebago Heights, Indian Heights, and Ho-Chunk Village. These residential areas, or housing sites, are located along or near the Middle Branch Embarrass, Black, Lemonweir, and Wisconsin Rivers or their tributaries. Water-quality data were compiled and summarized, and basin maps showing land cover and previous sampling sites are presented. Qualitative assessments of factors ...

2003-01-01

412

Radwaste Drum Assay Technology by Segmented Gamma Scanning System  

Energy Technology Data Exchange (ETDEWEB)

Nuclear Act of Korea requires the manifest of low and intermediate level radioactive waste generated from nuclear power plants and other nuclear facilities prior to deliver to a disposal sites. Individual history records of the radioactive waste should be described the information about the activity of nuclides in the drum, total activity, weight, the type of waste. So a fully automated nuclide analysis assay system(non-destructive) of a radwaste drum was developed. For the nuclides that could not be analysed directly by MCA, the activities of the representative {gamma}-emitters(Cs-137, Co-60) contained in the drum were measured by using that system. Then the scaling factors were used to calculate the activities of {alpha} - and {beta}-emitters. This assay system divided a drum into 8 segments, a segment into 8 sectors to minimize analysis error, and used several methods(transmission ratio, differential peak absorption, mean density correction), with a individual ...

2009-01-15

413

Radiation exposure of children in pediatric radiology. Pt. 5. Organ doses in chest radiography; Zur Strahlenexposition von Kindern in der paediatrischen Radiologie. T. 5. Organdosen bei der Roentgenuntersuchung des Thorax  

Energy Technology Data Exchange (ETDEWEB)

Purpose: Reconstruction of organ doses of selected organs and tissues from radiographic settings and exposure data collected during chest X-ray examinations of children of various age groups performed in Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007. Materials and Method: The dosimetric data of all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 119 150 chest radiographs of all age groups. Reconstruction of organ doses in 40 organs and tissues in X-ray examinations of the chest was performed based on the conversion factor concept. Results: The radiation exposure of organs in projection radiography is determined by the exact site of the organs relative to the edges of the X-ray field and the beam direction of ...

2009-05-15

414

Radiation 2006. In association with the Polymer Division, Royal Australian Chemical Institute. Incorporating the 21st AINSE Radiation Chemistry Conference and the 18th Radiation Biology Conference, conference handbook  

International Nuclear Information System (INIS)

Full text: The general population is daily exposed to chronic, low doses of ionizing radiation (IR) from both natural and artificial sources. The biological consequences of acute, high dose IR exposure can be readily determined; however, the nature and significance of low dose, low dose-rate IR effects are still the subject of debate. Confounding the issue, are the phenomena collectively referred to as the Radiation-induced Bystander Effect (RIBE). The RIBE describes a collection of in vitro observations that suggest the presence of a soluble, transmissible factor(s) released from irradiated cells that can induce a biological response in un-irradiated cells. The induction, nature and magnitude of the RIBE varies between cell culture systems, radiation sources and end-points measured. Efforts to confirm the presence of the RIBE in vivo have been confined to in vivo-like culture systems and limited work with tumour and bone-marrow transplantation models. Validation ...

2006-01-01

415

Proceedings of the CEMA reclamation workshop on creating wetlands in the oil sands : final report  

Energy Technology Data Exchange (ETDEWEB)

The Creating Wetlands in the Oil Sands Reclamation workshop was held to solicit expert views from leading authorities in a number of disciplines related to the creation and study of wetlands, as well as to investigate challenges in the creation of wetlands in reclaimed oil sands landscapes. This document provided a detailed transcript of each presentation and all discussions that followed. The workshop was divided into 5 sessions: (1) wetlands background information; (2) groundwater conditions and boreal wetlands; (3) creating wetland types; (4) wildlife in boreal wetlands and traditional environmental knowledge; and (5) treatment wetlands. An expert panel overview provided presentations on post-mining restoration of boreal landscapes in oil sands regions; the creation of fens, marshes and shallow water wetlands at oil sands sites and the restoration of damaged peatlands. A outline of the physical scale of the oil sands mining disturbances was provided during the first session, as well ...

2006-08-15

416

Pathogenesis of trypanosome infections in cattle  

International Nuclear Information System (INIS)

The potential application of radioisotopes are not discussed in this review of trypanosome pathogenesis in cattle. Initially, structural changes in the lymphoid system are characterized by marked proliferation and germinal centre formation, whereas in long-standing infections the lymphoid organs become depleted. These changes appear associated with immunodepression. Anaemia dominates the clinical disease syndrome in bovine trypanosomiasis. It develops with the onset of parasitaemia and is largely haemolytic, resulting from increased red blood cell destruction by phagocytosis. Several factors may be involved in this process including haemolysins produced by the trypanosome, immunological mechanisms, fever, disseminated intravascular coagulation and an expanded and active mononuclear phagocytic system. During this phase of the disease, cattle respond well to chemotherapy. However, in later phases of the disease, when trypanosomes cannot be detected, the anaemia ...

1979-05-11

417

Nerve growth factor actions on the brain  

International Nuclear Information System (INIS)

We examined the effect of the trophic protein, nerve growth factor (NGF), on cultures of fetal rat neostriatum and basal forebrain-medial septal area (BF-MS) to define its role in brain development. Treatment of cultures with NGF resulted in an increase in the specific activity of the cholinergic enzyme choline acetyltransferase (CAT) in both brain areas. CAT was immunocytochemically localized to neurons. In the BF-MS, NGF treatment elicited a marked increase in staining intensity and an apparent increase in the number of CAT-positive neurons. Moreover, treatment of BF-MS cultures with NGF increased the activity of acetylcholinesterase, suggesting that the cholinergic neuron as a whole was affected. To begin defining mechanisms of action of NGF in the BF-MS, we detected NGF receptors by two independent methods. Receptors were localized to two different cellular populations: neuron-like cells, and non-neuron-like cells. Dissociation studies with ...

418

Hydrogen systems analysis, education, and outreach. Annual report, August 1996--September 1997  

Energy Technology Data Exchange (ETDEWEB)

The set of activities performed by SENTECH, Inc. addressed the specific recommendations provided to the Department of Energy (DOE) by its advisors, including the Hydrogen Technical Advisory Panel and the review panel members of the DOE Annual Hydrogen Program Review. SENTECH`s efforts were conducted under five tasks: Task 1: Technology and Process Analysis; Task 2: Hydrogen Information Development and Transfer; Task 3: Educational Products; Task 4: Systems Analysis; and Task 5: Life Cycle Costs. SENTECH activities were executed in two broad areas--analysis and technology transfer. The analytical tasks undertaken in FY97 were focused on two types of analysis--systems analysis and technical/economic assessments. These analytical activities benefit DOE by providing data that allow it to define the strategic goals of the hydrogen R and D program. By collecting analysis of the energy efficiency, environmental externality, and economic competitiveness factors of hydrogen ...

1997-11-01

419

How the Performance of a Superconducting Magnet is affected by theConnection between a small cooler and the Magnet  

Energy Technology Data Exchange (ETDEWEB)

As low temperature cryocoolers become more frequently used to cool superconducting magnets, it becomes increasingly apparent that the connection between the cooler and the magnet has an effect on the design and performance of the magnet. In general, the use of small coolers can be considered in two different temperature ranges; (1) from 3.8 to 4.8 K for magnet fabricated with LTS conductor and (2) from 18 to 35 K for magnets fabricated using HTS conductor. In general, both temperature ranges call for the use of a two-stage cooler. The best method for connecting a cooler to the magnet depends on a number of factors. The factors include: (1) whether the cooler must be used to cool down the magnet from room temperature, (2) whether the magnet must have one or more reservoirs of liquid cryogen to keep the magnet cold during a loss of cooling, and (3) constraints on the distance from the cooler cold heads and the magnet and its shield. Two methods ...

2005-09-08

420

Effect of mutations in HNF-1#alpha# and HNF-1#beta# on the transcriptional regulation of human sucrase-isomaltase in Caco-2 cells  

International Nuclear Information System (INIS)

Mutations in transcription factors hepatocyte nuclear factors (HNF)-1#alpha# and HNF-1#beta# cause maturity-onset diabetes of the young (MODY) types 3 and 5, respectively. HNF-1#alpha# and HNF-1#beta# mutations are well studied in some tissues, but the mechanism by which HNF-1#alpha# and HNF-1#beta# mutations affect sucrase-isomaltase (SI) transcription in the small intestine is unclear. We studied the effects of 13 HNF-1#alpha# mutants and 2 HNF-1#beta# mutants on human SI gene transcription, which were identified in subjects with MODY3 and MODY5, respectively. Transactivation activity of 11 HNF-1#alpha# and 2 HNF-1#beta# mutants was significantly lower than that of wild (wt)-HNF-1#alpha# and wt-HNF-1#beta#. Furthermore, in co-expression studies with mutant (mu)-HNF-1#alpha#/ wt-HNF-1#beta# and wt-HNF-1#alpha#/mu-HNF-1#beta#, the combination of mu-HNF-1#alpha# (P379fsdelCT and T539fsdelC)/wt-HNF-1#beta# impaired SI ...

2004-12-03

421

Contaminant assimilation in newly created prairie wetlands  

Energy Technology Data Exchange (ETDEWEB)

Increased use of wetlands for habitat and water quality improvement emphasize the need for further study of abiotic-biotic interactions in these systems. This research examined contaminant assimilation within the water column of two newly created Colorado prairie wetlands (RMA3 and RMA4). To examine the influence of abiotic factors (e.g., alkalinity, suspended solids), ten chronic toxicity tests were performed from December 1991 through November 1993. In the first set of tests, Ceriodaphnia dubia were exposed to water from the two wetlands which was spiked with various concentrations of zinc. These tests suggested that water from RMA4 had higher contaminant assimilative capacity than water from RMA3. Preliminary analysis suggested suspended solids, pH, conductivity, and temperature were important factors affecting neonate production by C. dubia when exposed to zinc-spiked wetland water. To test the importance of suspended ...

1994-12-31

422

Consumer attitudes and decision-making with regard to genetically engineered food products: A review of the literature and a presentation of models for future research  

DEFF Research Database (Denmark)

Executive summary 1. Few studies have to date explained consumer attitudes and purchase decisions with regard to genetically engineered food products. However, the increased marketing of genetically engineered food products and the considerable concern that consumers seem to express with regard to the technology call for the development of a theoretical basis for research into these issues. 2. The aim of the paper is to present three models which we have developed to explain consumer attitudes, buying behaviour and attitude change with regard to genetically engineered food products. All three models build on established consumer behaviour theory and on existing and comparable research in the field. 3. Consumer attitudes toward genetic engineering in food products are explained in an attitude model that builds on Fishbein's multiattribute attitude model. The model deviates from Fishbein's model in a number of ways: there is an explicit distinction between perceived benefits and risks ...

1998-01-01

423

Analysis of Thermally Induced Permeability Enhancement in Geothermal Injection Wells  

Energy Technology Data Exchange (ETDEWEB)

Reinjection of spent geothermal brine is a common means of disposing of geothermal effluents and maintaining reservoir pressures. Contrary to the predictions of two-fluid models (two-viscosity) of nonisothermal injection, an increase of injectivity, with continued injection, is often observed. Injectivity enhancement and thermally-affected pressure transients are particularly apparent in short-term injection tests at the Los Azufres Geothermal Field, Mexico. During an injection test, it is not uncommon to observe that after an initial pressure increase, the pressure decreases with time. As this typically occurs far below the pressure at which hydraulic fracturing is expected, some other mechanism for increasing the near-bore permeability must explain the observed behavior. This paper focuses on calculating the magnitude of the near-bore permeability changes observed in several nonisothermal injection tests conducted at the Los Azufres Geothermal Field. In order to ...

1987-01-20

424

Acclimation of tree function and structure to climate change and implications to forest carbon and nutrient balances  

Energy Technology Data Exchange (ETDEWEB)

Before large-scale anthropogenetic emissions the environmental factors have been rather stable for thousands of years, varying yearly, seasonally and daily in rather regular manners around some mean values. In this century the emissions of CO{sub 2}, sulphur and nitrogen from society to atmosphere are changing both atmospheric and soil environment at rates not experienced before. The fluxes to soil affect the contents of plant available nutrients and solubility of toxic compounds in the forest soil. Additionally, the chemical state of soil environment is coupled to tree growth, litter production and nutrient uptake as well as to the activity of biological organisms in soil, which decompose litter and release nutrients from it. Trees have developed effective regulation systems to cope with the environment during the evolution. The resulting acclimations improve the functioning of the trees if the environmental factors remain ...

1996-12-31

425

A study of passive and inherent safety design concepts for advanced light= water reactors  

Energy Technology Data Exchange (ETDEWEB)

The five thermal-hydraulic concepts chosen for conceptual study of advanced PWR systems have been studied as follows: (1) Critical Heat Flux in passive PWR Conditions: review of previous works (various of correlations, analysis of parametric trends) on CHF, assessment and improvement of CHF prediction models for round tubes, development of the prediction model on bundle CHF with considering the correction factor calculated from the tube data base, design and construction of the intermediate-pressure CHF experimental loop, extension of CHF data base by performing the experiments at low-flow, and low-quality conditions (2) Passive Cooling Concepts for Concrete Containment Systems: Selection of the external condenser by comparing and reviewing between passive cooling concepts for concrete containment system concepts, survey and review of previous studies (theoretical mechanism of condensation heat transfer and effect of non-condensable gases) on the condensation ...

1997-07-01

426

A pilot-scale jet bubbling reactor for wet flue gas desulfurization with pyrolusite.  

Science.gov (United States)

MnO2 in pyrolusite can react with SO2 in flue gas and obtain by-product MnSO4 x H2O. A pilot scale jet bubbling reactor was applied in this work. Different factors affecting both SO2 absorption efficiency and Mn2+ extraction rate have been investigated, these factors include temperature of inlet gas flue, ration of liquid/solid mass flow rate (L/S), pyrolusite grade, and SO2 concentration in the inlet flue gas. In the meantime, the procedure of purification of absorption liquid was also discussed. Experiment results indicated that the increase of temperature from 30 to 70 K caused the increase of SO2 absorption efficiency from 81.4% to 91.2%. And when SO2 concentration in the inlet flue gas increased from 500 to 3000 ppm, SO2 absorption efficiency and Mn2+ extraction rate decreased from 98.1% to 82.2% and from 82.8% to 61.7%, respectively. The content of MnO2 in pyrolusite had a neglectable effect on SO2 absorption ...

2005-01-01

427

A numerical study of expected accuracy and precision in Calibration-Free Laser-Induced Breakdown Spectroscopy in the assumption of ideal analytical plasma  

Energy Technology Data Exchange (ETDEWEB)

Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy ...

2007-12-15

428

A numerical study of expected accuracy and precision in Calibration-Free Laser-Induced Breakdown Spectroscopy in the assumption of ideal analytical plasma  

International Nuclear Information System (INIS)

Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) has been proposed several years ago as an approach for quantitative analysis of Laser-Induced Breakdown Spectroscopy spectra. Recently developed refinement of the spectral processing method is described in the present work. Accurate quantitative results have been demonstrated for several metallic alloys. However, the degree of accuracy that can be achieved with Calibration-Free Laser-Induced Breakdown Spectroscopy analysis of generic samples still needs to be thoroughly investigated. The authors have undertaken a systematic study of errors and biasing factors affecting the calculation in the Calibration-Free Laser-Induced Breakdown Spectroscopy spectra processing. These factors may be classified in three main groups: 1) experimental aberrations (intensity fluctuations and inaccuracy in the correction for spectral efficiency of a detection system), 2) inaccuracy ...

2007-12-01

429

Imaging-based dust sensors: equipment and methods  

Science.gov (United States)

Dust detection and control in real time, represent one of the most challenging problem in all those environments where fine and ultrafine airborne particulate solids products are present. The presence of such products can be linked to several factors, often directly related and influenced by the working-production actions performed. Independently from the causes generating dust, airborne contaminants are an occupational problem of increasing interest as they are related to a wide number of diseases. In particular, airborne dusts are well known to be associated with several classical occupational lung diseases, such as the pneumoconiosis, especially at high levels of exposure. Nowadays there is also an increasing interest in other dust related diseases, from the most serious as cancer and asthma, to those related with allergies or irritation and other illnesses, also occurring at lower levels of exposure. Among the different critical factors ...

2004-05-01

430

Analytical study on integrity of BWR reactor internal structures against water hammer under RIA conditions  

Energy Technology Data Exchange (ETDEWEB)

The integrity of the RPV head and reactor internals was assessed by means of fluid-structural analyses using a coupled method to evaluate the water hammer phenomenon arising from high burnup fuel failure under RIA conditions. The fluid viscosity effect on the water column burst as well as the complex three-dimensional flow paths caused by a core shroud and standpipes were considered in this study. The three analysis scenarios were designed to investigate the above mentioned influential factors separately. In the first scenario, a two-dimensional axisymmetric reactor vessel model without any reactor internals was modeled to assess the influence of the fluid dynamics in the NSC RIA regulatory evaluation. This model has an actual RPV geometry and can be simply separated from other influential factors in order to concentrate only on investigation of the fluid viscosity effect. In the second scenario, a two-dimensional axisymmetric reactor vessel ...

2003-07-01

431

Synthetic Biology and Human Health: Potential Applications for Spaceflight  

Science.gov (United States)

Human space travelers experience a unique environment that affects homeostasis and physiologic

2011-01-01

434

Dept. of Labor  

Science.gov (United States)

... assistance for Iowa workers affected by layoffs at Electrolux [10/17/2011] DOL provides grant increment to ...

436

Possible health effects of working with VDUs.  

UK PubMed Central (United Kingdom)

A summary of the effects presented here is given in the table. The designation "factor present" implies that there is knowledge (from human or animal studies, or both) of a specific factor(s) present...Full Text Available

1989-04-01

437

Human Factors in Network Security  

Science.gov (United States)

... TITLE (Indlude Security Classifkcation) Human Factors in Network Security 12. ... FIELD GROUP SUBGROUP Human Factors, Network, Security 19. ...

1991-03-21

438

The language of pain: affective descriptors of pain are a better predictor of psychological disturbance than pattern of sensory and affective descriptors.  

Science.gov (United States)

The language used by chronic benign pain patients to characterize their pain complaint was analyzed to determine the best predictor of psychiatric disturbance. Using the 78 adjectives provided by the McGill Pain Questionnaire, the number of affective descriptors used was the best predictor of psychiatric disturbance. Addition of sensory descriptors either to augment the total number of descriptors used (magnitude) or as a pattern of sensory greater than affective or sensory less than affective failed to increase predictive strength. PMID:6877847

1983-06-01

440

Lack of association between polymorphisms in C4b-binding protein and atypical haemolytic uraemic syndrome in the Spanish population  

UK PubMed Central (United Kingdom)

Dysregulation of the alternative pathway of complement activation, caused by mutations or polymorphisms in the genes encoding factor H, membrane co-factor protein, factor I or factor B, is associated...Full Text Available

2009-01-01

441

Estrogen and brain-derived neurotrophic factor (BDNF) in hippocampus: complexity of steroid hormone-growth factor interactions in the adult CNS.  

UK PubMed Central (United Kingdom)

In the CNS, there are widespread and diverse interactions between growth factors and estrogen. Here we examine the interactions of estrogen and brain-derived neurotrophic factor (BDNF), two...Full Text Available

2006-12-01

442

Disulfide Bonds and the Quaternary Structure of Factor VIII/von Willebrand Factor  

UK PubMed Central (United Kingdom)

Human Factor VIII/von Willebrand factor, purified by calcium citrate-cellulose chromatography and 4% agarose gel filtration was subjected to sodium dodecyl sulfate gel electrophoresis on gels containing...Full Text Available

1978-09-01

444

SELECTIVE REMOVAL OF STRONTIUM AND CESIUM FROM SIMULATED WASTE SOLUTION WITH TITANATE ION EXCHANGERS IN A FILTER CARTRIDGE CONFIGURATION  

Energy Technology Data Exchange (ETDEWEB)

This report describes experimental results for the selective removal of strontium and cesium from simulated waste solutions using monosodium titanate (MST) and crystalline silicotitanate (CST)-laden filter cartridges. Four types of ion exchange cartridge media (CST and MST designed by both 3M and POROX{reg_sign}) were evaluated. In these proof-of-principle tests effective uptake of both Sr-85 and Cs-137 was observed. However, the experiments were not performed long enough to determine the saturation levels or breakthrough curve for each filter cartridge. POREX{reg_sign} MST cartridges, which by design were based on co-sintering of the active titanates with polyethylene particles, seem to perform as well as the 3M-designed MST cartridges (impregnated filter membrane design) in the uptake of strontium. At low salt simulant conditions (0.29 M Na{sup +}), the instantaneous decontamination factor (D{sub F}) for Sr-85 with the 3M-design MST cartridge measured 26, ...

2011-05-26

445

Visco-elastic energy dissipation in a SiAlON ceramic: Quantification and implications for fatigue resistance  

International Nuclear Information System (INIS)

In this letter a method to estimate the visco-elastic response of monolithic ceramics to cyclic loading conditions at high temperatures is proposed. A relation is observed between the visco-elastic energy dissipation measured for two silicon nitride materials, and the structural characteristics of their respective intergranular phases. Some consequences for the fatigue resistance of the tested materials, and of non-transforming monolithic ceramics in general, are discussed. Two batches (G for glassy and C for crystalline) of SiAlON have been studied. The G-batch is obtained by pressureless sintering of silicon nitride powder with Y_2O_3 (6 wt%) and 6AlN-SiO_2 (5 wt%) as sintering additives. The main phase after sintering is #beta#-sialon. Upon cooling from the sintering temperature the amorphous intergranular residues of the sintering additives and of SiO_2, which is unavoidably present as a thin layer on the silicon nitride powder, crystallize partially into YAM ...

446

VAWT (Vertical-Axis Wind Turbine) stochastic loads produced by atmospheric turbulence  

Science.gov (United States)

Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). A principal source of blade fatigue is thought to be the stochastic (i.e., random) aerodynamic loads created by atmospheric turbulence. This paper discusses the development of a model for the simulation of these stochastic loads, given the rotor geometry, operating conditions, and assumed turbulence properties. A Double-Multiple-Streamtube analysis is employed, which includes the effects of wind shear. Reynolds number variations, different airfoil sections and chord lengths along the blade span, and an empirical model for dynamic stall effects. Calculations are presented for the VAWT 34-m Test Bed currently being assembled at Bushland, Texas. Time histories of the loads, as well as their Fourier spectra, are presented and discussed. An unexpected finding is that the average output power is predicted to be more sensitive to ...

1987-01-01

447

The French design code: RCC-M status and on-going developments  

International Nuclear Information System (INIS)

Since 1978, an important effort has been on-going between Framatome and Electricite de France (EDF) to develop and update technical rules for the design and construction of nuclear power plants. Two design codes are developed, one for PWRs: RCC-M and one for FBRs: RCC-MR. After some comments on the organization of RCCM Commission, the paper presents: (1) the major differences with the ASME Section III Code for fatigue, plastic shakedown and rupture analysis; (2) the review of some important facts in terms of availability or maintenance costs (in-service inspection, replacements, repairs, etc.) of operating plants like underclad cracking, stratification, CRDM nozzles, cast elbows, steam generator tubes, etc.; (3) how can one take into consideration this operating feedback in RCC-M Code; and (4) few examples of major on-going developments for fracture analysis on different components and fatigue analysis of valves. In conclusion, the ...

1996-07-21

448

Self-lubricating performance and durability of ball bearings for the LE-7 liquid oxygen rocket-turbopump  

Energy Technology Data Exchange (ETDEWEB)

The durability of ball bearings, 32-mm- and 45-mm-bore, with a retainer or glass cloth-polytetrafluoroethylene (PTFE) laminate was tested under a high radial load at a speed of 20,000 rpm in LOX or LN2. The retainers were characterized as good self-lubricators because the abrasive glass-cloth fiber tips exposed on the retainer were chemicaly etched away with hydrofluoric acid (HF). During testing, the bearing-cartridge-acceleration was monitored to detect bearing damage. Testing in LOX for about 2.2 hr showed that excellent lubricating conditions were obtained for all bearings. Testing in LN2 for about 5.1 hr detected that the fatigue life of the bearing was about the same as the calculated B10 fatigue life. The HF chemical treatment resulted in a reacted fluoride-oxide material which remained in the etched part of the glass fiber. Several chemical products, particularly MgO, CaO, and CaCO3, enhanced adhesion of PTFE transfer film to the ...

1993-09-01

449

Sara: Service life prediction programme for surfaces of massive components under long-term creep fatigue load; Programm SARA fuer die Lebensdauerabschaetzung langzeitkriechermuedungsbeanspruchter Oberflaechen massiver Bauteile  

Energy Technology Data Exchange (ETDEWEB)

Computerized descriptions of isothermal, multi-stage creep fatigue load were established for one melt each of steels of the type 1%CrMoNiV and 12%CrMoV and were implemented in the service life prediction program SARA 2. SARA 2 predicts the time and number of cycles to incipient cracking for a given number of part cycles on the basis of rules for description of cyclic deformation and damage and of a generalized damage accumulation hypothesis. [German] Fuer je eine Schmelze der Staehle vom Typ 1%CrMoNiV and 12%CrMoV wurde eine rechnergestuetzte Beschreibung fuer isotherme mehrstufige Kriechermuedungsbeanspruchung erstellt und in ein Lebensdauerzaehlerprogramm SARA 2 implementiert. Auf der Grundlage von Regeln zur Beschreibung von zyklischer Verformung und Schaedigung unter Anwendung der verallgemeinerten Schadensakkumulationshypothese ermittelt SARA 2 fuer beliebig vorgebbare Teilzyklen einen Vorhersagewert fuer die Anrissdauer und die Anrisswechselzahl. (orig.)

2001-07-01

450

Progress on fatigue characterization of ITER primary first wall mock-ups  

International Nuclear Information System (INIS)

In 2001, EFDA has assigned to ENEA a contract for the thermomechanical testing of six mock-ups of the ITER primary wall module. These small scale mock-ups, reproducing representative portions of the reference ITER primary wall panels, were fabricated during ITER EDA phase by solid hot isostatic pressing (HIPping) of an AISI 316L stainless steel back structure to a alumina dispersion strengthened (DS)-Cu alloy heat sink armored with beryllium tiles. The experimental program, carried-out at ENEA Brasimone CEF 1-2 thermal hydraulic facility, was focused on the thermal mechanical testing of these mock-ups aiming at verifying which tile geometry and manufacturing procedure assures the required reliability of the beryllium/DS-Cu alloy/SS joints at high incident heat flux (>0.8 MW/m"2) both at steady state and under thermal fatigue tests. The paper presents the progress in the experimental activity of the first test campaign and the main thermomechanical FEM analyses ...

2003-09-01

451

On methods for improving the fatigue performance of the wrought magnesium alloys AZ31 and AZ80  

Energy Technology Data Exchange (ETDEWEB)

The tensile and compressive properties as well as LCF and HCF performance of the extruded magnesium alloys AZ31 and AZ80 were determined in extrusion (L) and long-transverse (T) directions. Owing to marked crystallographic textures, both alloys showed pronounced directional mechanical properties in monotonic as well as cyclic loading with strength values in L-direction being significantly superior to those in T-direction. Thermomechanical treatments such as pressing, swaging and rolling were found to increase yield stresses and HCF strengths and to alter the directionality in properties due to textural modifications. To further improve HCF strengths, mechanical surface treatments such as shot peening, roller-burnishing and deep rolling were utilized. The results indicate marked improvements provided that suitable process parameters are used. The improvement of the HCF strengths is explained by the process-induced changes in near-surface dislocation densities and the development of ...

2003-07-01

452

Modeling grain size during hot deformation of IN 718  

Energy Technology Data Exchange (ETDEWEB)

Aerospace gas turbine disks operate in an environment of relatively high stresses caused by centrifugal forces and elevated temperatures. These severe conditions necessitate the need for materials with high temperature strength and good low cycle fatigue resistance. One class of alloys used for this task is the nickel base superalloys, out of which, IN 718 is the most widely used in the aerospace industry. The properties of IN 718 are attributed to the combined effects of the chemistry, heat treatment, and microstructure. The chemistry is tailored not only for solid solution strengthening but also for precipitation hardening developed during heat treatment, which combined with a fine grained microstructure lead to excellent mechanical properties such as low cycle fatigue resistance and elevated temperature strength. The properties of a gas turbine disk are sensitive to the microstructure, in particular the grain size, which is dependent on the ...

1999-12-17

453

Microstructure and mechanical properties of a high strength bearing steel SAE 52100 produced by spray deposition; Gefuege und mechanische Eigenschaften eines durch Spruehkompaktieren hergestellten Stahles 100Cr6  

Energy Technology Data Exchange (ETDEWEB)

Spray depositing allows the production of steels having a structure which is free of any macro-segregation, homogeneous and equiaxed. Nevertheless the spray deposition of steels shows some effects that have to be regarded as disadvantages. A porous region at the billet border and a rather coarse-grained microstructure can be noticed. As a result, in the presented work the influence of a subsequent hot rolling and a following heat treatment on microstructure and mechanical properties has been investigated. For this purpose the bearing steel SAE 52100 has been used as master material. The initial microstructure has been transformed to a homogeneous equiaxed fine-grained pearlitic microstructure without any remaining porosity. To get use of the characteristic properties of this high-strength steel an isothermal bainitic hardening has been carried out. Information about the mechanical properties of this material has been gained by tensile and fatigue tests. For ...

2001-07-01

454

Manufacturing of small scale W monoblock mockups by hot radial pressing  

International Nuclear Information System (INIS)

In the frame of the European Technology R and D programme for International thermonuclear experimental reactor (ITER) and in the area of high heat flux plasma facing components (HHFC), representative small-scale mock-ups were manufactured and tested to compare different concepts and joining technologies (i.e. active brazing, hot isostatic pressing (HIPping), diffusion bonding, etc.). On the basis of the results obtained by thermal fatigue tests, the monoblock concept resulted to be the most robust one, particularly when the HIPping manufacturing technology is used. Within this programme, ENEA developed an alternative technique for manufacturing plasma-facing components with a monoblock geometry of the ITER machine. The basic idea of this technique, named hot radial pressing (HRP), is to perform a radial diffusion bonding between the cooling tube and the armour tile by pressurising the internal tube only and by keeping the process parameters within the range in ...

2003-09-01

455

High temperature fatigue damage in three austenitic alloys  

Energy Technology Data Exchange (ETDEWEB)

A series of cyclic strain controlled tests have been carried out at 600/sup 0/C on three high temperature austenitic iron-based alloys, AISI type 316 stainless steel, Alloy 800 H and Sandvik 253 MA. The tests were carried out under constant total strain control using a constant strain rate of 0.005 s/sup -1/. By considering the changes in modulus throughout the life of each specimen it was found that damage evolution could be successfully predicted as a function of plastic strain range despite the fact that each alloy had been chosen because of a different stress response at 600/sup 0/C. Although each alloy accumulated fatigue damage in a similar manner the longer lives of Sandvik 253 MA and Alloy 800 H at a given total strain range were due to a smaller plastic strain component and a reduced stage I crack propagation rate. In the 253 MA alloy, slip was predominantly planar with some cells occasionally forming at high strain ranges. Slip was localized in Alloy 800 ...

1988-01-01

456

Fault assessment in large welded- and cast iron parts; Fehlerbeurteilung in grossen Schmiede- und Gussteilen  

Energy Technology Data Exchange (ETDEWEB)

The results of these investigations can be summarised as follows: At simulated operating stress most naturally occuring faults in welded- and cast iron parts develop cracks and can be assessed for reliability under fatigue-,creep- and creep fatigue behaviour according to the laws of fracture mechanics. The empirically determined correlation between the real fault size and the ultrasonic inspection results (height of echo, echo dynamics, sound weakening) lead to better assessment of real fault extension in turbine components. It is very important to adapt the method of inspection and assessment to the type of possible fault.(orig.) [German] Die bei diesen Untersuchungen ermittelten Ergebnisse lassen sich wie folgt zusammenfassen: - Die Mehrzahl der untersuchten natuerlichen Fehlstellen in den Schmiede- und Gussstuecken verhalten sich unter den simulierten Betriebsbeanspruchungen rissartig und sind damit mittels den bruchmechanischen Gesetzen in ...

1998-07-01

457

Fatigue behavior of vertical axis wind turbine airfoils with two weld configurations  

Energy Technology Data Exchange (ETDEWEB)

Sandia National Laboratories contracted with Rockwell International Science Center to perform a series of narrowband, pseudo-random cyclic fatigue tests on sections of 6063-T651 aluminum, Darrius-type, vertical axis wind turbine (VAWT) airfoils. We designed and constructed a load member that was mounted within the frame of a rigid 200-kip servohydraulic, closed-loop test system to hold the VAWT section and permit cantilever bending along the shear centerline of the beam. A computer program was developed to synthesize a narrow band, pseudo-random load history with fixed root mean square (RMS) stress levels at a given bandwidth and central frequency. Six specimens each of two different weld configurations at the flange mounting plate were tested at several RMS stress levels with failure defined as visual observation of a 3-inch-long crack in the VAWT. In order to test at as great a frequency as possible, a 20-kip hydraulic ram with a 10-GPM servovalve was employed ...

1989-10-01

458

Effect of mean stress (stress ratio) and aging on fatigue-crack growth in a metastable beta titanium alloy, Ti-10V-2Fe-3Al  

International Nuclear Information System (INIS)

The effect of mean stress, or the stress ratio (R), on the fatigue-crack growth (FCG) behavior of #alpha#-aged and #omega#-aged microstructures of the beta titanium alloy Ti-10V-2Fe-3Al was investigated. While the mean stress had a negligible effect on the FCG behavior of the #alpha#-aged microstructure, a strong effect was observed in the #omega#-aged microstructure. In particular, the values of the threshold stress-intensity range (#DELTA#K_t_h) exhibited a strong dependence on R in the #omega#-aged microstructure, while this dependence was weak in the #alpha#-aged microstructure. These effects seem to arise primarily from fracture-surface roughness-induced crack closure. The crack closure levels for the #alpha#-aged microstructure were found to be very low compared to those for the #omega#-aged microstructure. Transmission electron microscopy and scanning electron microscopy studies of microstructures and fracture surfaces were performed to gain insight into the ...

2000-03-01

459

Characterization of coatings and the low cycle fatigue behaviour of 316L  

Energy Technology Data Exchange (ETDEWEB)

In the framework of the European Fusion Technology Programme ECN participates in a NET task PSM-8 `Coatings and Surface Effects on Stainless Steel 316L`. High emissivity coatings were developed for enhanced heat transfer from graphite tiles to a Stainless Steel First Wall. Four candidate materials, Cr{sub 2}O{sub 3}, Black Cr, Al{sub 2}O{sub 3}/TiO{sub 2} and TiC were tested as candidate high emissivity coatings. These coatings were manufactured by atmospheric and vacuum plasma spraying technique and the Black Chromium coatings were manufactured by a galvanic coating technique. The tests included total emissivity measurements and Low Cycle Fatigue (LCF) experiments. The total emissivity of two TiC coatings at 525 K appeared to be 0.62 and 0.64. The total emissivity of the TiC and 5 wt% TiO{sub 2}/Al{sub 2}O{sub 3} coating was about 0.7. (orig.)

1993-03-01

460

Molecular basis of factor VIII inhibition by human antibodies. Antibodies that bind to the factor VIII light chain prevent the interaction of factor VIII with phospholipid.  

UK PubMed Central (United Kingdom)

Most antibodies to factor VIII have recently been shown to react with discrete regions of the factor VIII light chain (within the C2 domain) and/or the factor VIII heavy chain (within the amino-terminal...Full Text Available

1989-06-01

461

Thermomechanical fatigue of ODS superalloys; Thermomechanische Ermuedung von ODS-Superlegierungen  

Energy Technology Data Exchange (ETDEWEB)

The ODS superalloys MA 6000 and MA 760 were investigated with regard to their behaviour under non-isothermal fatigue stress. For this purpose, strain-controlled thermomechanical and bithermal experiments with different phase relationships between strain and temperature were carried out on the one hand; on the other hand, the deformation behaviour under thermomechanical stress was modelled on the basis of isothermal cyclic creep data. The fatigue experiments show that a diamond-shaped cycle derived from the stress pattern of a turbine blade is clearly less critical than in-phase and out-of-phase cycles. The life of the diamond-shaped cycle is determined by oxidation-induced crack initiation and propagation and can be predicted easily with a suitable damage model. Important damage parameters required by the model can be obtained by the less complicated bithermal fatigue tests. Modelling of the TMF hystereses suggests that ...

1995-07-01

462

Replacement of bearing journals on heat transport pumps at the Wolsung nuclear generating station  

International Nuclear Information System (INIS)

The major details of the inspection and replacement of the bearing journals on each of the four heat transport pumps (HTPs) at Wolsung nuclear generating station in Korea are presented in this paper. Investigation following fracture of one of the journals in 1985 revealed that it was excessively hard. The journal material (ASTM A296 CA 40) is considered to be prone to stress corrosion fatigue if the hardness exceeds Rc 40. In 1986 May, during a planned outage, the HTPs were disassembled, the journals were inspected, found to be excessively hard, and all were replaced. At the same time, the pump to motor couplings were all refurbished to ensure proper alignment.

1987-11-22

463

Laboratory robotics systems at the Savannah River Laboratory  

International Nuclear Information System (INIS)

Many analytical chemistry methods normally used at the Savannah River site require repetitive procedures and handling of radioactive and other hazardous solutions. Robotics is being investigated as a method of reducing personnel fatigue and radiation exposure and also increasing product quality. Several applications of various commercially available robot systems are discussed involving cold (nonradioactive) and hot (radioactive) sample preparations and glovebox waste removal. Problems encountered in robot programming, parts fixturing, design of special robot hands and other support equipment, glovebox operation, and operator-system interaction are discussed. A typical robot system cost analysis for one application is given.

1983-11-16

464

LES benchmark study of high cycle temperature fluctuations caused by thermal striping in a mixing tee  

Energy Technology Data Exchange (ETDEWEB)

Thermal striping is identified as one of the causes of thermal fatigue failure in nuclear power plants. Numerical studies of thermal striping require three-dimensional, unsteady turbulent modeling that resolves both large and small-scale turbulent motions. Benchmark studies were carried out using the LES turbulence model solved by the commercial CFD code FLUENT. Two types of mixing tee configurations were modeled to evaluate the performance of the CFD code. The simulation results presented in normalized average temperature and normalized fluctuating temperatures are in good agreement with measurements.

2006-02-15

465

Fear, panic and prosperity consciousness: developing resilience as the paradigm shifts  

British Library Electronic Table of Contents (United Kingdom)

Purpose - The article shares insights from a program that was developed to address burnout, compassion fatigue and vicarious trauma. The program works from the premise that people and organizations thrive when they have shared values and common understandings. Design/methodology/approach - The approach draws together reflection at the organizational and person levels. Connecting business ethics and organizational analysis, improving understanding of the body's energy as well as inter-cultural understanding are all achievable while adopting the resilience development methods. Findings - The article concludes that reflective practice through the tools used on the program enhances understanding of the challenges faced by organizations and the individuals involved. It provides creative routes ...

2009-01-01

466

Fatigue and creep cracking of nickel alloys for 700 C steam turbines  

International Nuclear Information System (INIS)

Four materials of the types Inconel 706 (two heat treatment states), Inconel 617, and Waspaloy were tested as shaft materials for 700 to 720 C steam turbines. At an extrapolation time ratio of 10, Waspaloy was expected to have the highest creep strength (about 270 MPa at 700 C), with values of about 140 MPa at 700 C for Inconel 617. A preliminary evaluation of the 700 C creep rupture tests showed the highest creep rupture resistance for Inconel 617, followed by Waspaloy and Inconel 706.

2000-12-01

467

Evaluation of ultrasonic indications in steam turbine rotors by fracture mechanics analysis  

International Nuclear Information System (INIS)

The report summarizes ten years of experience in the analysis and evaluation of ultrasonic testing data measured in turbine and generator rotors. Apart from the information on type, position, size and distribution of flaws, the expert knowledge achieved in an interpretation of ultrasonic signals yields further insight, as e.g.: - Confirmation of assumptions taken as a basis for fracture-mechanical analysis of these flaws with regard to crack initiation and crack growth under low-cycle fatigue conditions (O=0.7-1 Rp 0.2, N<25.000 growth in length); - enhanced information on a correlation of ultrasonic testing data with the real flaw size. (orig.).

1990-10-04

468

Effects of high steam parameters on steam turbine materials; Einfluss hoher Dampfzustaende auf Werkstoffe von Dampfturbinen  

Energy Technology Data Exchange (ETDEWEB)

Higher efficiencies of steam power plants are achieved by raising the operating temperature and pressure. The use of ferritic steels helps to minimize the cost and enhance the flexibility (two-shift operation, frequent starting and stopping). The COST programme had the long-term goal of developing and testing 9- 12 % Cr steels with high fatigue strength and to produce,test and operate critical components for an advanced steam power plant (steam temperature 600 C and supercritical pressure). (orig.)

1996-12-31

469

Damage tolerance of metalic structures  

Energy Technology Data Exchange (ETDEWEB)

This Workpackage Report describes the introduction of fatigue cracks in bolts with ISO-metric threads M5x0.8, M8x1.0, M12x1.25 made from the materials Ti 6Al 4V, A-286 and INCONEL 718. Introdued cracks are verified by destructive testing. Results of the NDI of these bolts performed with special eddy current probes are reported. The detectability of cracks with a {>=} 0.65 and a/2c {approx equal} 0.3 located in the thread ground perpendicular to the load axis is demonstrated. (orig.).

1991-01-01

470

Corrosion resistance of modern austenitic-ferritic (duplex) stainless steel. Corrosion of special types. (Review)  

International Nuclear Information System (INIS)

Recent data on resistance of modern corrosion-resistant austenitic-ferritic steels to different types of corrosion are generalized. It is shown that these steels are characterized by high resistance to general corrosion in acid, alkali, chloride and other solutions, are not inclined to intercrystalline, pitting and crevice corrosion and are noted for high resistance to corrosion cracking and corrosion fatigue. All this is combined with technological and economical effectiveness. It is advisible to use these steels instead of highly-alloyed and expensive steels and alloys in chemical, power and other industries. 59 refs.; 2 tabs.

471

Brittle fracture problem in composite insulators  

Energy Technology Data Exchange (ETDEWEB)

The report traces the documented incidences of brittle fracture in composite suspension insulators for use on high voltage transmission lines, and presents the subsequent investigations. It describes the part played by electrical activity, stress corrosion and humidity, and compares similar failures that have taken place in electric traction insulators. It then goes on to review related work on the humidity effects, stress corrosion, fatigue and partial discharges in glass fiber reinforced plastics in general. The final section summarizes the present understanding of the problem and the various measures taken by different manufactures to avoid it in the future. The need for acceptance criteria in this respect is outlined.

1984-04-01

472

Automatic-control system for the 17-metre vertical-axis wind turbine (VAWT)  

Science.gov (United States)

The 17-metre DOE/Sandia VAWT began operation in March 1977. Since that time the turbine has been operated strictly by manual control for the purpose of data acquisition and performance analysis; this procedure has limited the VAWT operation time and power output. An automatic-control system has been designed and implemented to study automatic control of a VAWT and to better judge the fatigue life and reliability of the VAWT under what will be normal operating conditions for power production. This system, including the necessary hardware, is discussed in detail along with a simplified cost analysis.

1980-03-01

473

Risk-based inspection in ASME Section XI  

International Nuclear Information System (INIS)

By 1970 the first edition of the ASME Code Section XI, Inservice Inspection of Nuclear Reactor Coolant Systems was published. From its inception, the Section XI inservice inspection scope was based on a fundamental risk-based selection process. In other words the inservice inspection scope included components where the consequences of a pressure boundary failure were high. Once the consequence significant system boundaries were established, inspections would then be performed at locations believed to be most susceptible service induced failure. Current Section XI requirements require that inspection locations be selected on the basis of peak stress and fatigue usage values contained in the Design Reports. These original stress calculations were designed to qualify a design and assure that the plant would provide reliable service throughout its design life. For the most part, the fatigue usage values in these reports do not provide an accurate ...

1996-07-21

474

Long-term behaviour of heat-resistant steels and high-temperature materials. Langzeitverhalten warmfester Staehle und Hochtemperaturwerkstoffe  

Energy Technology Data Exchange (ETDEWEB)

This book contains 10 lectures with the following subjects: On the effect of thermal pretreatment on the structure and creep behaviour of the alloy 800 H (V. Guttmann, J. Timm); Material properties of heat resistant ferritic and austenitic steels after cold forming (W. Bendick, H. Weber); Investigations for judging the working behaviour of components made of alloy 800 and alloy 617 under creep stress (H.J. Penkalla, F. Schubert); Creep behaviour of gas turbine materials in hot gas (K.H. Kloos et al.); Effect of small cold forming on the creep beahviour of gas turbine blades made of Nimonic 90 (K.H. Keienburg et al.); Investigations on creep fatigue alternating load strength of nickel alloys (G. Raule); Change of structure, creep fatigue behaviour and life of X20 Cr Mo V 12 1 (by G. Eggeler et al.); Investigations on thermal fatigue behaviour (K.H. Mayer et al.); Creep behaviour of similar welds of the steels 13 Cr Mo 4 4, ...

1987-01-01

475

Early detection of damage and analysis of damage development in metal structural components. Schaedigungsfrueherkennung und Schadensablauf bei metallischen Bauteilen  

Energy Technology Data Exchange (ETDEWEB)

The topics of these short lectures on the subject of cyclic stress were: Microstructural mechanisms of damage accumulation under a multistage cyclic stress until incipient cracking; influence of surface decarbonizing phenomena on the failure behaviour of steel construction parts subjected to cyclic stress; thermocyclic fatigue of pipe samples of austenitic steel 1.4436; studies on surface structuring, microstructure and fatigue in LCF area. The short lectures on effects of quasi-static and creep stress were: Shear fracture in AlMg alloys as a result of local plastic instability; study of formation and growth of pores for an early recognition of damage and the course of damage in heat-resistant steels under creep test; experimental and numeric studies of the infuence of the microstructure on the course of damage during shear fractures of steel; numerical modelling of ductile fractures on the basis of micromechanical models. Under the topic of ...

1989-01-01

476

Brain SPECT of chronic fatigue syndrome (CFS): SPM analysis of two age groups  

International Nuclear Information System (INIS)

Full text: Chronic fatigue syndrome (CFS) is a complex disorder characterised by profound fatigue and neuropsychiatric dysfunction. Previous studies with cerebral perfusion SPECT (rCBF) scans were performed with inhomogeneous patient populations and were not analysed with Statistical Parametric Mapping (SPM). We have used SPM to study subjects with moderate CFS based on the Fukuda criteria, who were not on medication and not depressed, compared to age matched control subjects. An apparent bimodal age distribution has been observed in CFS. Subjects were therefore divided into two age groups: 16-35 or under 35 (17 CFS, 11 control) and 36-61 or over 35 (15 CFS, 15 control). HMPAO brain SPECT was acquired on a 3-head camera. After lower window scatter subtraction, reconstruction with attenuation correction (mu=0.15/cm) and editing of facial activity, scans were spatially normalised (affine + 2x3x2 nonlinear) to SPM's anatomical space. SPM ...

2002-05-04

477

Application of continuous casting steel 100Cr6 (SAE 52100) for bearing balls  

Energy Technology Data Exchange (ETDEWEB)

The objective of the investigation was to study the feasibility of applying continuous casting steel 100Cr6 (SAE 52100) for bearing balls. It was found that two of three continuous casted steel batches have longer or at least similar rolling contact fatigue lifetimes compared to one ingot casted batch. For one of the continuous casted batches, the rolling contact fatigue lifetime was 30% less. The micro- and macrostructure and the residual stresses below the surface of the balls were comparable. There is also no obvious difference between the four batches in the metallurgical parameters like contents of oxygen, titanium and sulfur as well as in the distribution of carbides and their network. The reason for the shorter lifetime of one batch finally was found to be due not to the continuous casting process itself. There was a difference in the cross section of the different casting moulds, and by this in the speed of solidification. As a ...

1998-12-31

478

Pain measurement: the affective dimensional measure of the McGill pain questionnaire with a cancer pain population.  

Science.gov (United States)

Two experiments used the McGill Pain Questionnaire (MPQ) to examine the affective dimension of pain in patients whose pain was secondary to malignancy. In experiment I, segregating groups of cancer patients on the basis of extreme scores (high versus low) on the MPQ failed to produce segregation on independent measures of affect and infirmity. This outcome contrasts with earlier work with chronic benign pain patients. Experiment II compared cancer pain patients matched with benign pain patients on intensity of pain report on the affective dimension of the MPQ. Cancer pain patients reported a reliably higher affective loading to their pain. These data suggest that cancer pain patients employ different criteria than benign pain patients in selecting affective pain descriptors. Possible explanations for this difference are discussed. PMID:7070825

1982-02-01

479

Crack growth behaviour of low alloy steels for pressure boundary components under transient light water reactor operating conditions (CASTOC)  

Energy Technology Data Exchange (ETDEWEB)

The CASTOC project addresses environmentally assisted cracking (EAC) phenomena in low alloy steels used for pressure boundary components in both Western type boiling water reactors (BWR) and Russian type pressurised water reactors (VVER). It comprises the four work packages (WP): inter-laboratory comparison test (WP1); EAC behaviour under static load (WP2), EAC behaviour under cyclic load and load transients (WP3); evaluation of the results with regard to their relevance for components in practice (WP4). The use of sophisticated test facilities and measurement techniques for the on-line detection of crack advances have provided a more detailed understanding of the mechanisms of environmentally assisted cracking and provided quantitative data of crack growth rates as a function of loading events and time, respectively. The effect of several major parameters controlling EAC was investigated with particular emphasis on the transferability of the results to components in service. The ...

2004-07-01

480

Analysis of the Semileptonic Decay D0 --> anti-K0 pi- mu+ nu  

Energy Technology Data Exchange (ETDEWEB)

This thesis describes the analysis of the semileptonic decay D{sup 0} {yields} {bar K}{sup 0} {pi}{sup -} {mu}{sup +}{nu} using FOCUS data. FOCUS is a fixed target experiment at Fermilab that studies the physics of the charm quark. Particles containing charm are produced by photon-gluon fusion from the collision of a photon beam on a BeO target. The experiment is characterized by excellent vertex resolution and particle identification. The spectrometer consists of three systems for track reconstruction (two silicon systems and one multiwire proportional chamber system) and two magnets of opposite polarity. The polarity of the magnet is such that the events of e{sup +}e{sup -} pairs produced in the target (which constitutes the main background) travel through a central opening in the detectors without interactions. Particle momentum is measured from the deflection angle in the magnets. Three multicell Cerenkov counters are used for charged particle identification (for e, {pi}, K, and ...

2004-11-01

481

Flexible responses to visual and olfactory stimuli by foraging Manduca sexta: larval nutrition affects adult behaviour  

UK PubMed Central (United Kingdom)

Here, we show that the consequences of deficient micronutrient (β-carotene) intake during larval stages of Manduca sexta are carried across metamorphosis, affecting adult behaviour....Full Text Available

2009-08-07

482

Role of radiation therapy in the management of nonmetastatic Ewing's sarcoma of bone. Report of the intergroup Ewing's sarcoma study  

International Nuclear Information System (INIS)

The role of radiation therapy in local tumor control and decreased incidence of pulmonary metastasis is reported in 271 patients who were entered into the Intergroup Ewing's Sarcoma Study with more than one year follow-up and on whom all radiotherapy records were reviewed. The majority of the patients were irradiated to the primary tumor with doses of 4500 to 6500 rad in five to six weeks in combination with systemic administration of three drugs (vincristine, actinomycin-D and cyclophosphamide) or four drugs (vincristine, actinomycin-D, cyclophosphamide and adriamycin). One of the groups of patients was treated with three drugs and bilateral pulmonary irradiation (1500 rad, uncorrected dose, in two weeks). Preliminary analysis shows an overall local primary tumor control of 89%. Patients with lesions in the pelvis had a local failure rate of 17% (9 of 52) and in the humerus 23% (7 of 31). Factors affecting local recurrences are analyzed in ...

483

Road traffic exhaust gas emissions in Finland. LIISA 2001.1 calculation model; Suomen tieliikenteen pakokaasupaeaestoet. LIISA 95 -laskentajaerjestelmae  

Energy Technology Data Exchange (ETDEWEB)

This publication describes the modification of the road traffic exhaust emission calculation model LIISA and presents the new calculation results. The model has already established its position as the most important inventory tool for regional road traffic emissions in Finland. The LIISA model calculates road traffic emissions as a whole. The system comprises of three separate models: 1. a model for calculating automobile emissions for the years 2001-2021, 2. a model for calculating emissions backwards for the years 1980-2000, 3. a model for calculating the emissions of motorcycles and mopeds. All three parts have been modified. The LIISA model is one of the submodels of the comprehensive LIPASTO calculation system developed at VTT Building and Transport. The LIPASTO model is an inventory tool for emissions regarding all traffic modes in Finland. The LIPASTO with its submodels will be updated yearly with new mileage and vehicle data. The models itself and their emission ...

2002-07-01

484

Redesigning standard retail tariffs for competition: New tools and strategies  

Energy Technology Data Exchange (ETDEWEB)

Utilities looking to thrive in increasingly competitive markets are reexamining their approach to pricing. To compete effectively, utilities will need to both control costs and offer customers pricing options that are competitive and reflect the diversity in their customer base. These price structures must reflect two key factors -- marginal costs, which will increasingly reflect market prices, and consumers` responsiveness to those price structures. To accomplish this requires the capability to forecast customers` response to price structures that often provide complex signals to customers about how changes in their energy consumption and maximum power demand affect their bill, and to calculate corresponding changes in utility profits and customer net benefits. Much discussion of competitive pricing focuses on innovative new rate structures. However, significant opportunities are present to improve matters by simply redesigning current ...

1996-03-01

485

Radioactive iodine absorbing properties of tetrathiafulvalene  

Energy Technology Data Exchange (ETDEWEB)

For the purpose of searching some effective absorbents of gaseous radioactive iodine, 16 substances considered as having an affinity for iodine were investigated with regular iodine and /sup 125/I. In a preliminary survey, only tetrathiafulvalene (TTF) was found to have satisfactory absorbing properties comparable to activated charcoal. A further detailed comparison of the properties between TTF and activated charcoal led us to the conclusion that the former has more preferable properties as absorbent of radioactive iodine than the latter in all points studied. The results are summarized as follows: (1) The absorption of iodine on TTF in atmosphere was about twice as much as that on activated charcoal. Desorption of iodine from saturatedly absorbed iodine on TTF was practically negligible except trace amount of initial desorption, while that on activated charcoal was considerable (3%/50h) even in the air at room temperature. (2) Absorbed amount of iodine on activated charcoal decreased ...

1989-05-01

486

Modelling of multifrequency IRMPD for laser isotope separation  

International Nuclear Information System (INIS)

The process of infrared multiple photon dissociation (IRMPD) of molecules is of great fundamental importance and has practical significance, such as isotope separation etc. Unfortunately, a clear insight into the process has been hindered by the bewildering array of important variables affecting MPD. The dissociation probability #gamma#(#phi#) i.e. the yield has been found to be a sensitive function of laser fluence #phi# along with numerous other parameters like laser frequency, gas pressure etc. We have shown that in single frequency IRMPD an accurate quantitative characterization of the dissociation probability can be adequately expressed by a 'power law' model with two fitting parameters namely critical fluence, #phi#c and multi photon order, m. This model was exploited in analysing our MPD results on various systems. However, the small isotope shift encountered in heavy elements and the sticking phenomenon observed in small light molecules restrict ...

2002-12-01

487

Glacier changes in the Siberian Altai Mountains, Ob river basin (1952-2006) estimated with high resolution imagery  

Energy Technology Data Exchange (ETDEWEB)

The Siberian Altai covers about 70% of the area of all south Siberian glaciers, which provide fresh water to the upper tributaries of the Ob and Yenisey rivers. The observed air temperature has increased by 1.2 deg. C over northern Eurasia during the last 120 years, affecting the degradation of the Siberian Altai glaciers. In this study, we estimated glacier area changes in the Aktru River basin (44.8 km{sup 2}), located in the central Altai mountains. We used the 1952, 1966, 1975 and 2006 remote sensed images with 0.6-3.0 m spatial resolution (aerial photographs, Corona and PRISM satellite images) and differential GPS (DGPS) data. From 1952 to 2006, the total glacier area in the Aktru basin shrank by 7.2% (1.2 km{sup 2}). During the last three decades, the rate of glacier area loss increased by a factor of 1.8, thus resembling trends in other mountain systems of Eurasia (Alps, Tien Shan). The glacier area changes were caused mainly by increase ...

2007-10-15

488

Glacier changes in the Siberian Altai Mountains, Ob river basin (1952-2006) estimated with high resolution imagery  

International Nuclear Information System (INIS)

The Siberian Altai covers about 70% of the area of all south Siberian glaciers, which provide fresh water to the upper tributaries of the Ob and Yenisey rivers. The observed air temperature has increased by 1.2 deg. C over northern Eurasia during the last 120 years, affecting the degradation of the Siberian Altai glaciers. In this study, we estimated glacier area changes in the Aktru River basin (44.8 km"2), located in the central Altai mountains. We used the 1952, 1966, 1975 and 2006 remote sensed images with 0.6-3.0 m spatial resolution (aerial photographs, Corona and PRISM satellite images) and differential GPS (DGPS) data. From 1952 to 2006, the total glacier area in the Aktru basin shrank by 7.2% (1.2 km"2). During the last three decades, the rate of glacier area loss increased by a factor of 1.8, thus resembling trends in other mountain systems of Eurasia (Alps, Tien Shan). The glacier area changes were caused mainly by increase of summer ...

489

Geothermal Heat Pump Profitability in Energy Services  

Energy Technology Data Exchange (ETDEWEB)

If geothermal heat pumps (GHPs) are to make a significant mark in the market, we believe that it will be through energy service pricing contracts offered by retailcos. The benefits of GHPs are ideally suited to energy service pricing (ESP) contractual arrangements; however, few retailcos are thoroughly familiar with the benefits of GHPs. Many of the same barriers that have prevented GHPs from reaching their full potential in the current market environment remain in place for retailcos. A lack of awareness, concerns over the actual efficiencies of GHPs, perceptions of extremely high first costs, unknown records for maintenance costs, etc. have all contributed to limited adoption of GHP technology. These same factors are of concern to retailcos as they contemplate long term customer contracts. The central focus of this project was the creation of models, using actual GHP operating data and the experience of seasoned professionals, to simulate the financial ...

1997-11-01

490

Gene Repressive Activity of RIP140 Through Direct Interaction with CDK8.  

Science.gov (United States)

Receptor interacting protein 140 (RIP140) is a coregulator for numerous nuclear receptors and transcription factors and primarily exerts gene-repressive activities on various target genes. We previously identified a spectrum of posttranslational modifications on RIP140 that augment its property and biological activity. In T(3)-triggered biphasic regulation of cellular retinoic acid binding protein 1 (Crabp1) gene along the course of fibroblast-adipocyte differentiation, we found TRAP220(MED1) critical for T(3)-activated chromatin remodeling whereas RIP140 essential for T(3)-repressive chromatin remodeling of this gene promoter. In this current study, we aim to examine whether and how RIP140 replaces TRAP220(MED1) on the CrabpI promoter in differentiating adipocyte cultures. We find increasing recruitment of RIP140 to this promoter, with corresponding reduction in TRAP220(MED1) recruitment during the T(3)-repressive phase. We also uncover direct interaction of ...

2011-08-25

491

Fluxes of methane and nitrogen oxides in various boreal mire ecosystems. Effects of land-use activities and environmental changes  

Energy Technology Data Exchange (ETDEWEB)

Atmospheric impact of peatlands is a sum of their gas fluxes. In contrast to carbon dioxide, peatlands are net sources for methane (CH{sub 4}). Methane is an end product in the anaerobic decomposition processes and it has greater capacity to absorb infrared radiation than carbon dioxide. Most of the data on the CH{sub 4} release from northern peatlands is from North America. The total amount of methane released from wetlands is calculated to be 110 Tg yr{sup -1} of which 34 percent (38 Tg yr{sup -1}) is estimated to be emitted from the northern peatlands. Peat with high content of nitrogen is a potential source for gaseous nitrogen oxides, i.e. nitrous oxide (N{sub 2}O) and nitric oxide (NO). However, the importance of peatlands in producing these trace gases is poorly known. Nitrous oxide and nitric oxide are important components in the atmospheric chemistry and N{sub 2}O also is an effective greenhouse gas. Land-use activities and environmental changes can affect ...

1996-12-31

492

Closed string tachyons, AdS/CFT, and large N QCD  

Energy Technology Data Exchange (ETDEWEB)

We find that tachyonic orbifold examples of AdS/CFT have corresponding instabilities at small radius, and can decay to more generic gauge theories. We do this by computing a destabilizing Coleman-Weinberg effective potential for twisted operators of the corresponding quiver gauge theories, generalizing calculations of Tseytlin and Zarembo, and interpreting them in terms of the large-N behavior of twisted-sector modes. The dynamically generated potential involves double-trace operators, which affect large-N correlators involving twisted fields but not those involving only untwisted fields, in line with large-N inheritance arguments. We point out a simple reason that no such small radius instability exists in gauge theories arising from freely acting orbifolds, which are tachyon free at large radius. When an instability is present, twisted gauge theory operators with the quantum numbers of the large-radius tachyons aquire vacuum expectation values, leaving a gauge ...

2001-10-15

493

Closed String Tachyons, AdS/CFT, and QCD  

Energy Technology Data Exchange (ETDEWEB)

We find that tachyonic orbifold examples of AdS/CFT have corresponding instabilities at small radius, and can decay to more generic gauge theories. We do this by computing a destabilizing Coleman-Weinberg effective potential for twisted operators of the corresponding quiver gauge theories, generalizing calculations of Tseytlin and Zarembo and interpreting them in terms of the large-N behavior of twisted-sector modes. The dynamically generated potential involves double-trace operators, which affect large-N correlators involving twisted fields but not those involving only untwisted fields, in line with large-N inheritance arguments. We point out a simple reason that no such small radius instability exists in gauge theories arising from freely acting orbifolds, which are tachyon-free at large radius. When an instability is present, twisted gauge theory operators with the quantum numbers of the large-radius tachyons acquire VEVs, leaving a gauge theory with fewer ...

2001-07-25

494

Choice of energy data in environmental assessment of the built environment  

Energy Technology Data Exchange (ETDEWEB)

Life cycle oriented methods are increasingly used for environmental assessments (EAs) of the built environment. However, many assumptions are made in such assessments, potentially influencing the results and making the assessment more ambiguous. To increase the reliability of EAs, consequences of the assumptions made have to be better understood. Since energy use in the operation and maintenance phase is an important factor decisive for the overall environmental performance of a building, the purpose of this study is to investigate how the selection of heat and electricity mix affects the assessed environmental performance of buildings. It also aims to suggest how to choose heat and electricity data in EAs of the built environment in general. Applying four different modes of electricity production and two different modes of heat production in a case study of three different buildings with different technical solutions for heat and electricity ...

2003-03-01

495

Cement-clay pastes for stabilization/solidification of 2-chloroaniline  

International Nuclear Information System (INIS)

Immobilization of a model liquid organic pollutant, i.e. the 2-chloroaniline (2-CA), into a cement matrix using organoclays as pre-sorbent agents was investigated. Five cement-clay pastes were prepared with different nominal water-to-cement ratios (w/c=0.40, 0.25 and 0.15 wt/wt) and various amounts of waste (waste-to-cement o/c=0.20, 0.60 and 1.00 wt/wt); for comparison, a neat cement paste was also prepared. Dynamic leach tests were performed on solidified monoliths in order to assess the successful immobilization of the 2-CA. In monoliths at constant w/c ratio (0.40) the total amount of pollutant released increases with its initial content, and ranges from 15 to 35% with respect to it. By lowering w/c from 0.40 to 0.15 at constant o/c, the performances improved (<25% released). The microstructure of the hardened cement-clay pastes was characterized by quantitative X-ray diffraction (QXRD) and electronic microscopy (SEM-EDS) techniques; hydration degree was estimated by means of ...

2004-01-01

496

C-14 release and transport from a nuclear waste repository in an unsaturated medium  

Energy Technology Data Exchange (ETDEWEB)

The release of {sup 14}C as {sup 14}CO{sub 2} from partly failed spent fuel containers has been analyzed by the flow of gases into and out of the containers. This flow of gases is driven by pressure differences, which are in turn caused by heating by the spent fuel. In this analysis, the timing and size of holes in the containers are assumed to be given. A better means of predicting the time distribution and sizes of penetrations in nuclear waste containers is needed. For the purposes of far-field transport calculations, we have adopted release rates that are shown to be bonding for the large range of hole sizes studied. The transport of released {sup 14}CO{sub 2} has been analyzed by transport in equivalent porous medium. The peak {sup 14}CO{sub 2} concentration in pore gas at 350 m above the repository does not depend on the time of hole occurrence, although the time of penetration obviously affects the arrival and duration of exposure to {sup 14}C. Nor does ...

1990-06-01

497

Brain mechanisms supporting the modulation of pain by mindfulness meditation.  

Science.gov (United States)

The subjective experience of one's environment is constructed by interactions among sensory, cognitive, and affective processes. For centuries, meditation has been thought to influence such processes by enabling a nonevaluative representation of sensory events. To better understand how meditation influences the sensory experience, we used arterial spin labeling functional magnetic resonance imaging to assess the neural mechanisms by which mindfulness meditation influences pain in healthy human participants. After 4 d of mindfulness meditation training, meditating in the presence of noxious stimulation significantly reduced pain unpleasantness by 57% and pain intensity ratings by 40% when compared to rest. A two-factor repeated-measures ANOVA was used to identify interactions between meditation and pain-related brain activation. Meditation reduced pain-related activation of the contralateral primary somatosensory cortex. Multiple regression ...

2011-04-01

498

Alteration of leached glass surface  

Energy Technology Data Exchange (ETDEWEB)

The leached glass is subject to leachant attack and results in surface layer alteration which greatly affects the corrosion progress of glass forms. This work studied the composition change, precipitation, pitting corrosion as well as surface layer break and spallation of the leached glass forms. 6 conclusions can be made: 1. The extent of surface layer alteration is related to many factors such as temperature, pH, leachant chemistry, flow rate and leach duration, etc. 2. The alkali element Na is seriously depleted and the elements like U.Ti,Fe, Ca and Mg are enriched in the surface layer. The influence of media has such order: Fe{sub 2}O{sub 3} > Na-bentonite > Zeolite. 3. The precipitate formed in leach test for 56 days at 90 {infinity}C is mostly amorphous, but after 91 days has crystallized. There is K - Ca - Al - Si crystal,the amount of Al, K and Si is increasing, but the amount of Ca is decreasing along with leaching time. ...

1997-07-01

499

A study of the importance of occupancy to building cooling load in prediction by intelligent approach  

International Nuclear Information System (INIS)

Research highlights: #-># The building occupancy affecting the cooling load prediction is studied. #-># PENN model is adopted in this study for predicting the building cooling load. #-># Statistical approach is adopted to result a less prejudice prediction performance. #-># Results show that occupancy data can significantly improve the prediction. -- Abstract: Building cooling load prediction is one of the key factors in the success of energy-saving measures. Many computational models available in the industry today have been developed from either forward or inverse modeling approaches. However, most of these models require extensive computer resources and involve lengthy computation. This paper discusses the use of data-driven intelligent approaches, a probabilistic entropy-based neural (PENN) model to predict the cooling load of a building. Although it is common knowledge that the presence and activity of building occupants have a ...

2011-07-01