Science.gov (United States)

Unsteady impinging jets are systematically controlled with respect to their time dependence in order to investigate the influence of unsteadiness on the heat transfer performance. This is achieved by a special mass flow control device, which allows almost arbitrary shapes of unsteadiness to be imposed onto the impinging jet. Three different standard signals (sinusoidal, triangular, rectangular) and two specially designed signals are applied and their influence on heat transfer is determined in terms of an enhancement factor. Heat transfer augmentation up to 30% was found and could be physically explained with the help of PIV and hot-wire measurements of the flow field.

International Nuclear Information System (INIS)

When decontaminated with continuously replenished CAN-DECON reagent in a once-through system, carbon steel contaminated with "6"0Co during exposure to reducing coolant in stainless steel loops loses up to 90 percent of its radioactivity in the first few minutes. Afterwards, the rate of removal falls to much lower values which persist for many hours to the end of the experiment. The effects of flow rate, temperature and reagent concentration on the initial rates of decontamination indicate that mass transfer in the liquid is an important factor in the decontamination. The decontamination factor is influenced by the initial rate.

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Short communication. 1 ref., 4 figs.

Energy Technology Data Exchange (ETDEWEB)

The electrogeometric model cannot consider the influence of some parameters on the screening of the wire conductor of the H.V. lines. For analysing the influence of these parameters (the conductor potential, the influence of the distance from phase conductor to earth wire, the influence of the reducing factor of the striking earth distance, the earth slope, etc.), the Monte Carlo method is preferable. The influence of the earth slope on the screening effect of the wire conductor for different conditions is presented in this paper. (author)

UK PubMed Central (United Kingdom)

This paper deals with the indications for prostatectomy; the differential diagnosis of the symptomatology of bladder neck obstruction; and the factors influencing the choice of operation....Full Text Available

International Nuclear Information System (INIS)

The population of the hyporheic interstice and moss cushions by meso- and macroinvertebrates as found at the three measuring points along the Alte Riefensbeek and the Grosse Soese, respectively, in the period from March 1987 to May 1988 is studied and evaluated together with chemical measurements performed between 1987 and 1990. The six measuring points are positioned along an acidification gradient ranging from non-acid to severely acidified. Chemical and biological paramerters are studied with regard to their suitability as indicators of acidification. A model is presented which decribes the influence of abiotic anthropogenic and natural factors on invertebrate species diversity and populations and which can serve as a basis for the calculation of critical deposition burdens. (orig.).

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 ...

British Library Electronic Table of Contents (United Kingdom)

Program decisions by symphony orchestra management are influenced by various factors. To examine these factors, we create an objective index of the propensity of a symphony orchestra to perform the standard repertoire. We use regression analysis to examine factors that influence programming decisions of 64 US symphony orchestras in 2006?2007, including public and private sources of funding. We find that increased funding from ticket sales, endowments, and local government increases the likelihood that an orchestra will perform nonstandard repertoire. In addition, the results suggest that a symphony orchestra?s music director does not have a significant impact on the degree of program conventionality.

Energy Technology Data Exchange (ETDEWEB)

The problem of buried steelwork in cargo hold insulation has been investigated by several using empirical methods. These efforts have resulted in correction factors that serve as a useful aid in the complex task of estimating the K-value of a ship`s cargo holds for the correct dimensioning of the refrigeration plant. Today, the advent of the digital computer has established numerical methods of analysis as a common working tool among practicing engineers. For estimating the flow in cases of buried steelwork that cannot be handled by correction factors, this is an effective approach. This study is an analytical/numerical investigation of the effect that buried steelworks have on the heat leakage across cargo hold walls. It aims at providing enlightenment on the physical significance of the parameters influencing the problem and developing practically simple methods for predicting the heat leakage across ...

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows:In order to practice a design-by-analysis of thermohydraulics design of BWR fuel rod bundles, the subchannel analysis would play a major role. There, the immediate concern is improvement in its predictive capability of CHF due in particular to the film dryout (boiling transition phenomena: BT) on the fuel rod surface. Constitutive equations in the subchannel analysis formulation are responsible for the quality of calculated results. The constitutive equations are a result of integration of the local and instantaneous description of two-phase flows over the subchannel control volume. In general, they are expressed in terms of subchannel-control-volume- as well as area-averaged two-phase flow state variables. In principle the information on local and instantaneous physical phenomena taking place inside subchannels must be counted for in the algebraic form of the equations on the basis of a more mechanistic ...

UK PubMed Central (United Kingdom)

There are many factors that can influence glucose uptake by contracting skeletal muscle during exercise and although one may be intramuscular glycogen content, this relationship is at present not fully...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundPeak bone mass, attained by early adulthood, is influenced by genetic and life-style factors. Early infant feeding and duration of breastfeeding in particular, associate...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundProfessionalism is a critical quality for physicians to possess. Physician professionalism has received increased attention in recent years, with many authorities suggesting...Full Text Available

UK PubMed Central (United Kingdom)

Background:Prolonged mechanical ventilation is increasingly common. It is expensive and associated with significant morbidity and mortality. Our objective is to comprehensively characterize...Full Text Available

UK PubMed Central (United Kingdom)

Techniques for culturing, harvesting, and testing bacteria to evaluate bactericidal chemicals for swimming pools are described. Concentrations of 25, 50, and 100 mg of the chlorine stabilizer cyanuric...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundPerichondrium is recognized as a tissue with chondrogenic potential yielding cells which can be used for osteochondral repair. Factors which influence the proliferative...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundPolymorphisms in Epidermal Growth Factor Receptor (EGFR) gene may influence EGFR production and/or activity, thereby modulating susceptibility to lung...Full Text Available

International Nuclear Information System (INIS)

For the layout of a pressure suppression system of a light water cooled reactor (boiling water reactor) it is important to know the time dependent behavior of the vent clearing transient after a loss-of-coolant accident for two main reasons: time of the end of the vent clearing transient influences strongly the pressure and temperature maxima in the drywell and wetwell. Time-dependent behavior of the vent clearing transient influences pressure loads in the condensation pool of the wetwell and therefore pressure induced stresses to the structure. The time-dependent behavior of the water masses in the vent pipes and wetwell are described by the basic equations for a nonstationary incompressible friction flow: momentum equation, continuity equation and a correlation for the variation of the state of the gas volume in the wetwell above the water level. After many algebraic operations and integrations along the ...

Science.gov (United States)

airborne separation assistance systems (ASAS) to ... operations should be limited to the outer traffic flow ...... AGARD Meeting on Machine Intelligence in Air ...

Energy Technology Data Exchange (ETDEWEB)

The performance of PAN-based composite absorbers was evaluated in dynamic experiments at flow rates ranging from 25--100 bed volumes (BV) per hour. Composite absorbers with active components of ammonium molybdophosphate (AMP) PAN and K-Co ferrocyanide (KCoFC) PAN were used for separating Cs from a 1 M HNO{sub 3} + 1 M NaNO{sub 3} + 2 {times} 10{sup {minus}5} M CsCl acidic simulant solution. KCoFC-PAN and two other FC-based composite absorbers were tested for separating Cs from alkaline simulant solutions containing 0.01 M to 1 M NaOH and 1 M NaNO{sub 3} + x {times} 10{sup {minus}4} M CsCl. The efficiency of the Cs sorption on the AMP-PAN absorber from acidic simulant solutions was negatively influenced by the dissolution of the AMP active component. At flow rates of 50 BV/hr, the decontamination factor of about 10{sup 3} could be maintained for treatment of 380 BV of the feed. With the KCoFC-PAN ...

Energy Technology Data Exchange (ETDEWEB)

The concepts of general flow and thermal boundary conditions are introduced to treat the interaction between indoor and outdoor thermal environments in computational fluid dynamics (CFD) simulations. The results from a multi-zone model are used to supply the general flow boundary conditions. The energy balance equation at wall-air interfaces is used to supply the general thermal boundary conditions. An example calculation in a 13-room building shows that infiltration influences indoor air flow patterns considerably. The air flow in a room ventilated by displacement is measured and simulated. Two surface coatings are considered, i.e. black walls and aluminum walls. Implementation of these two boundary conditions is essential in predicting air flow patterns, air quality, and thermal comfort in a real building. (author)

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, ...

Science.gov (United States)

The biological age (BA) of the majority of the liquidators of the consequences of the radiation accidents in the Navy and of the liquidators of the Chernobyl' APS accident exceeds the medium standard and the DBA (due BA). The index of the BA can be a characteristic of the influence of the social-hygienic factors on the health condition of the Special Risk Subunit--the liquidators of the consequences of the radiation accidents. It was established, that the radiation influence concerns to the factors dramatically increasing the BA and the rate of senescence of the liquidators of the consequences of the radiation accidents. PMID:21809627

Energy Technology Data Exchange (ETDEWEB)

The report deals with: (1) two-phase flow regime transitions, (2) liquid entrainment in break flow, (3) vapor pull-through, and (4) CCFL in horizontal ducts. The first three processes influence the mass flow through the break, whereas the fourth one imposes a limit on liquid flow from the steam generator through the hot leg break into the core. Correlations available in the literature which deal with these processes are presented and applied to a hot leg of a PWR, LOFT and Semiscale for quantitative estimates, as well as for determining the scale distortion in the latter two facilities.

Science.gov (United States)

When induced by bottom heating in a horizontal fluid layer which is characterized by forced motion or solute stratification, buoyancy-driven flows may assume a variety of forms. The flows, which are examples of mixed or double-diffusive convection, can strongly influence heat tranfer or the entrainment of stratified fluid. General aspects of each form of convection are reviewed, and emphasis is placed on mixed convection in a horizontal rectangular channel and on double-diffusive convection due to thermally driven mixed-layer development in a solutally stratified fluids. Flow conditions are described, and experimental and theoretical results are presented for related heat-transfer and entrainment parameters.

Energy Technology Data Exchange (ETDEWEB)

Radium is known to be taken up by aquatic animals, and tends to accumulate in bone, shell and exoskeleton. The most common approach to estimating the uptake of a radionuclide by aquatic animals for use in health and environmental risk assessments is the concentration factor method. The concentration factor method relates the concentration of a contaminant in an organism to the concentration in the surrounding water. Site specific data are not usually available, and generic, default values are often used in risk assessment studies. This paper describes the concentration factor method, summarizes some of the variables which may influence the concentration factor for radium, reviews reported concentration factors measured in marine environments and presents concentration factors derived from data collected in a study in coastal Louisiana. The ...

CERN Document Server

The stock market has been known to form homogeneous stock groups with a higher correlation among different stocks according to common economic factors that influence individual stocks. We investigate the role of common economic factors in the market in the formation of stock networks, using the arbitrage pricing model reflecting essential properties of common economic factors. We find that the degree of consistency between real and model stock networks increases as additional common economic factors are incorporated into our model. Furthermore, we find that individual stocks with a large number of links to other stocks in a network are more highly correlated with common economic factors than those with a small number of links. This suggests that common economic factors in the stock market can be understood in terms of deterministic ...

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 ...

International Nuclear Information System (INIS)

An experimental study was undertaken to determine for the turbulent regime the heat transfer and fluid flow characteristics of a heat exchange array of unperforated, and perforated brass plates with 33% of the plate area open. In both cases, the plates were aligned parallel to the flow direction. For the flow conditions examined, the results showed enhancement of heat transfer and friction factor for the perforated array.

UK PubMed Central (United Kingdom)

BackgroundClinical studies suggest that local wall shear stress (WSS) patterns modulate the site and the progression of atherosclerotic lesions. Computational fluid dynamics (CFD)...Full Text Available

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 ...

Energy Technology Data Exchange (ETDEWEB)

The heat transfer augmentation effect by the unsteady heat conduction between the particles and heat transfer surface is one of the main factors, causing the heat transfer augmentation around the stagnation point in the gas-solid two-phase impinging jet flow. By separating and evaluating that effect, material influence on it was studied of particles and heat transfer surface, together with change by the jet flow condition. That effect enlarged with enlarging in heat capacity, multiplied by the heat conduction coefficient, of both the particles and heat transfer surface, and if both of them were constant in material combination, was dominated by the contact frequency of particles per unit time. Therefore in case of lading solid particles, equal in weight, that effect enlarges with diminishing in particle diameter. Such a heat transfer augmentation mechanism model is universally applicable to the data by ...

Energy Technology Data Exchange (ETDEWEB)

Methane (CH{sub 4}) produced microbially in sediments of marshes is emitted to the atmosphere primarily by flowing through and out of emergent aquatic plants. The magnitude of such emission rates and factors controlling those rates are not well understood. We evaluated CH{sub 4} emission from the widely distributed aquatic emergent plant cattail (Typha latifolia L.) in several wetlands in the United States using a field gas-exchange system that concurrently estimated stomatal aperture (i.e., conductance) on the surface of leaves and net photosynthesis. We compared gas exchange among plants of different age and from sites with different soil and atmospheric conditions. The mean rate of CH{sub 4} emission was 0.22{mu}mol m{sup -2} [leaf] s{sup -1}, which is 940 mg CH{sub 4} m{sup -2} d{sup -1} on a ground-area basis, with individual rates ranging from 0.01 to 1.49 {mu}mol m{sup -2} [leaf] s{sup -1}. For individual plants, we found emission rates ...

Energy Technology Data Exchange (ETDEWEB)

Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10{sup 6}n/cm{sup 2}-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,{integral}dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow ...

Energy Technology Data Exchange (ETDEWEB)

A semi-mechanistic model for calculating solid radionuclide release rates from bubbling pools of sodium was developed. The influence of particle spacial and size distributions on the decontamination of the releases was analysed and found significant. Decontamination factors are shown as a function of pool depth, bubbling characteristics and particle size distribution. The calculation of a decontamination factor for estimating the source term of large scale hypothetical core disruptive accidents is presented. The decontamination factor for a large scale accident was found to be two orders of magnitude greater than results obtained from small scale experiments conducted with uniform particle distributions.

Energy Technology Data Exchange (ETDEWEB)

The influence of bowl offset on motored mean flow and turbulence in a direct injection diesel engine has been examined with the aid of a multi-dimensional flow code. Results are presented for three piston geometries. The bowl geometry of each piston was the same, while the offset between the bowl and the cylinder axis was varied from 0.0 to 9.6% of the bore. The swirl ratio at intake valve closing was also varied from 2.60 to 4.27. It was found that the angular momentum of the air at TDC was decreased by less than 8% when the bowl was offset. Nevertheless, the mean (squish and swirl) flows were strongly affected by the offset. In addition, the distribution of turbulent kinetic energy (predicted by the /delta/-e model) was modified. Moderate increases (10% or less) in mass averaged turbulence intensity at TDC with offset were observed.

Energy Technology Data Exchange (ETDEWEB)

The authors study, in forced convection, the evaporation of an Ostwaldian film flowing over an isothermal inclined plane surface to determine the influence of the behaviour index of the liquid on the dynamic and thermal characteristics of liquid-air system. The liquid flow is considered partially two-dimensional whereas for the air it is two-dimensional. The coupled equations with the interfacial conditions are solved using a fully implicit finite differences method. From the study, it appears that the behaviour index influences considerably the transfers which are more important for pseudo-plastic liquids than for dilatant ones. (authors)

UK PubMed Central (United Kingdom)

Sixty-five patients operated with total pancreatectomy were reviewed with respect to factors influencing operative mortality and morbidity, long-term survival, and metabolic sequelae. The diagnoses...Full Text Available

UK PubMed Central (United Kingdom)

Before the influence of divergent factors on gross efficiency (GE) [the ratio of mechanical power output (PO) to metabolic power input (PI)] can be assessed, the variation in GE between days, i.e. the...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundSupport groups have proved to be effective in reducing the burden on family caregivers of dementia patients. Nevertheless, little is known about the factors that influence...Full Text Available

UK PubMed Central (United Kingdom)

Purpose: This paper reviews and reassesses the internationally accepted niches or ‘targets’ in bone marrow that are sensitive to the induction of leukaemia and primary...Full Text Available

UK PubMed Central (United Kingdom)

The outcome of patients admitted to intensive care units is known to be influenced by such factors as age, previous health status, severity of disease, and diagnosis. To estimate the outcome of such...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundLittle is known about the acceptability of internet and telephone treatments, or what factors might influence patient interest in receiving treatments via...Full Text Available

UK PubMed Central (United Kingdom)

Typically, modern economics has steered away from the analysis of sociological and psychological factors and has focused on narrow behavioural assumptions in which expectations are formed on the basis...Full Text Available

UK PubMed Central (United Kingdom)

Tissue culture conditions and transformation have been established for both aspen and poplar. The use of previously described culture conditions resulted in shoot tip necrosis in the shoot cultures...Full Text Available

UK PubMed Central (United Kingdom)

The occurrence of outbreaks of cholera in Africa in 1970 and in Latin America in 1991, mainly in coastal communities, and the appearance of the new serotype Vibrio cholerae O139 in...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundParents of chronically ill children are at risk for a lower Health Related Quality of Life (HRQoL). Insight in the dynamics of factors influencing parental HRQoL is necessary...Full Text Available

International Nuclear Information System (INIS)

Full text: Chemical-technology approaches allowing to intensification the prevention processes of gas hydrates formation at motion of gas-liquid stream of natural gas in system natural gas well - gas wire have been worked up. Technological regimes of treatment of gas stream have been determined. Linear correlation dependences inhibitor electrolytes contained hydrated ions with different ion radii and charges of subgroups of alkali elements with one - type electron configuration were obtained. Important physico-chemical parameters of electrolytes have been determined: activity; coefficients of activity, viscosity, diffusion; density; heat capacity; heat conductivity; surface tension and freezing-point. The features of continuous influence of inhibitory factors on process of gas flow at low temperatures and relatively high pressure differences ?P have been studied by using of technological installation modulating the system ...

Science.gov (United States)

The melting unit, consisting of a water-cooled cupola furnace, afterburner, heat exchanger, air preheater, consumes most of the supplied energy in the rockwool process. The report maps the energy flows and defines factors of merit according to thermodynam...

UK PubMed Central (United Kingdom)

Obesity is a risk factor for stroke and neurodegenerative disease. Excess body fat has been linked to impaired glucose metabolism, insulin resistance, and impulsivity and may be a precursor to decline...Full Text Available

International Nuclear Information System (INIS)

Mitsubishi is developing a new type of accumulator incorporating the technology of fluidics as one of the seeds for the improved safety of the newly constructed pressurized water reactor plants. This accumulator employs a vortex flow control device, called a vortex damper, as a fluidic device to simplify the safety systems. A fundamental experimental study with a one-fifth scale model and confirmation tests with a one-third scale model to develop the vortex damper have been carried out, and satisfactory results have been achieved. The results of the confirmation tests under the prototype pressure conditions agree well with the basic tests. The flow rate ratio can be 5 to 6. The pressure loss coefficient in the large flow rate period is 8. A cavitation factor is the main parameter of the flow rate coefficient.

Energy Technology Data Exchange (ETDEWEB)

Pitting corrosion is localized accelerated dissolution of metal that occurs as a result of a breakdown of the otherwise protective passive film on the metal surface. This paper provides an overview of the critical factors influencing the pitting corrosion of metals. The phenomenology of pitting corrosion is discussed, including the effects of alloy composition, environment, potential, and temperature. A summary is then given of studies that have focused on various stages of the pitting process, including breakdown of the passive film, metastable pitting, and pit growth. 120 refs.

International Nuclear Information System (INIS)

Many factors influence radon-222 influx and radon-daughter concentrations in underground uranium mines. A brief review of some of these factors is presented. Current radon-222 and radon-daughter control principles and practices for US underground uranium mine atmospheres are discussed and a brief review of the applicability of other possible control methods such as rock sealants, radon-222 removal, and radon-daughter removal is given.

Science.gov (United States)

This investigation concerns the nonlinear dynamics of heat transfer from a surface using an upstream eddy promoter. A numerical model is developed for the coupled fluid flow and heat transfer process based on a modified MacCormack scheme. Numerical simulations are carried out to determine the response and heat transfer enhancement due to the promoter. The average heat transfer from a cavity floor is seen to be increased by a factor of approximately five over the unpromoted'' flow. Another interesting feature of the study is the nonlinear viscous flow dynamics from the cylinder-wall interaction which differ significantly from the familiar cylinder-free stream patterns.

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...

Energy Technology Data Exchange (ETDEWEB)

The form factor for excitation of the 1/sup +/ state at 3.48 MeV in /sup 88/Sr by inelastic electron scattering has been measured for momentum transfers q = 0.24-0.62 fm/sup -1/. Neither its magnitude nor shape can be described employing the best available nuclear wave functions. We demonstrate with a schematic model that the observed reduction of the form factor may be understood by taking into account a renormalization of the M1-operator due to virtual ..delta..-hole excitations.

Energy Technology Data Exchange (ETDEWEB)

Experimental investigation was carried out for friction factor and heat transfer coefficient in the case of a rotating tube with a twisted-tape insert for heat transfer augmentation. The data obtained were compared with existing data for a stationary tube with a twisted-tape insert. It has been observed that the enhancement in heat transfer offsets the rise in friction factor due to rotation, with respect to a plain tube under stationary conditions. A correlation has been proposed for the data obtained.

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: The heat transfer and flow in narrow channels has lots of advantages such as compact structure, high efficiency, design flexibility and so on. So it is widely used in the fields such as the new reactor core plate elements, the once-through stream generator, compact heat exchangers as well as electronic components. In recent years, more strong attentions have been attracted to the thermal-hydraulic characteristics and mechanism of the two-phase flow in narrow channels. As the flow regime characteristics of two-phase flow is fundamental one of them, the research on the two-phase flow regimes and the regime transitions in horizontal rectangular narrow heated channels can provide theoretical foundation and engineering directions to the whole research on the thermal-hydraulic characteristics and mechanism of the two-phase flow in ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

The need to increase efficiency of volumetric receivers for use in solar power plants by reducing reradiation losses and increasing the ``volumetric effect`` has promoted the idea of a receiver with tapered ducts. These seems to be very promising since higher efficiency and considerable saving of material can be achieved, as compared to conventional receivers perforated with ducts of constant cross-section. A finite element program is being developed to calculate stationary heat transfer in the tapered ducts by free and forced convection in the gas flow, conduction in walls and in the gas, and solar and thermal radiation. Gas and wall temperatures are considered to be varying only in the flow direction. In order to perform the highly nonlinear calculations of radiative exchange, the exact knowledge of the view factors is necessary. The aim of the present work is to evaluate analytically the view factors ...

Energy Technology Data Exchange (ETDEWEB)

Due to the high investment and operation costs incurred by dryers up to 50% of the proceeds from the cultivation of medicinal plants have to be spent on drying. This study was conducted in order to determine whether these costs can be lowered when solar energy is used. As little is known about the drying behaviour of medicinal plants even today one selected sage and camomile in order to study the influence of temperature, relative humidity, and drying air velocity on drying time and drug quality. Laboratory results were used as a basis for developing a solar hothouse dryer for medicinal plants which uses the whole roof surface as solar collectors with a batch dryer set up within the hothouse. In contrast to dryers of this type used up to now a foil green house with a gable roof was used. Installation of a central heating system helps to avoid bottlenecks, allows drying at night and increases plant flow by a factor of 3. The ...

International Nuclear Information System (INIS)

The unsteady flow and heat transfer are simulated using LES and DNS for a channel with two angled ribs as a vee-shaped vortex generator to augment heat transfer. The vortex generators are attached on the bottom wall of the channel and their angles in respect to the main flow are between 10"o and 30"o. The Prandtl number is 0.71 and the Reynolds numbers based on the inflow velocity and the height of channel are from 200 to 2000. Based on the results of this work, the variations of the Nusselt number, pressure coefficient, bulk temperature, friction factor and Colburn factor with the Reynolds numbers and the incidence angles are provided. The relation between the key parameters of the velocity (friction factor f) and thermal (Colburn factor J) boundary layers is calculated for all cases and their values are compared with the predicted values by the Chilton-Colburn ...

Energy Technology Data Exchange (ETDEWEB)

Tests have been conducted on a special compression ignition research engine to investigate the effects of gaseous fuels on the ignition delay in dual fuel engines. Diesel oil, n-heptane, or cetane were used as pilot fuels, and hydrogen, carbon monoxide, or methane were inducted in the intake manifold. Induction of nitrogen was used as a reference to eliminate the influence of changes in oxygen concentration and specific heats. Helium was inducted in additional tests. From the results of a number of parameter variations, the cylinder charge temperature (determined by intake temperature and compression ratio), the pilot fuel amount, and the flow of combustible gas were found to have the most significant influence on the ignition delay.

Science.gov (United States)

Turbulent flow in a 2D channel with repeated rectangular rib roughness was numerically simulated using a low Reynolds number form of the k-epsilon turbulence model. Friction factors and average Stanton numbers were calculated for various pitch to rib height ratios and bulk Reynolds numbers. Comparisons with experiment were generally adequate, with the predictions of friction superior to those for heat transfer. The effect of variable properties for channel flow was investigated, and the results showed a greater effect for friction than for heat transfer. Comparison with experiment yielded no clear conclusions. The turbulence model was also validated for a related problem, that of flow downstream of an abrupt pipe expansion.

International Nuclear Information System (INIS)

Purpose: To provide a feedwater control device capable of minimizing the adverse response of steam drum level at low power. Consitution: In order to perform feedwater control at low power by the substantial control of three factors, that is, main steam flow rate, feedwater flow rate and steam drum level, the main steam flow rate is determined from the reactor output and feedwater rate is determined from the changes in the feedwater temperature due to the mixing of waters in the reactor clean up system and feedwater. If a difference is resulted between these flow rates, a starting feedwater regulator is controlled instantly to eliminate the difference. The water level in the steam drum is used for amending the difference from the final set value of the drum water level, by which the adverse response of the steam drum level can be minimized. (Seki, T.).

International Nuclear Information System (INIS)

In the present study, a subcooled boiling loop with an annular flow on the electrically heated rod was used to make an experimental approach to investigate the effects of induced instability by the subcooled boiling on vibration of the rod in different subcooled conditions. The results show the intensive subcooled-boiling-induced vibration (SBIV) which is highly depend on dynamic force generated by fast vapor bubbles growth and collapse whilst they still attach to, or slide along, the heating surface at high loading heat fluxes. These behaviors were strongly influenced by the conditions of subcooling temperature, flow rate and linear power density. (author)

Energy Technology Data Exchange (ETDEWEB)

Experimental investigation of heat transfer and friction factor characteristics of circular tube fitted with full-length helical screw element of different twist ratio, and helical screw inserts with spacer length 100, 200, 300 and 400mm have been studied with uniform heat flux under laminar flow condition. The experimental data obtained are verified with those obtained from plain tube published data. The effect of spacer length on heat transfer augmentation and friction factor, and the effect of twist ratio on heat transfer augmentation and friction factor have been presented separately. The decrease in Nusselt number for the helical twist with spacer length is within 10% for each subsequent 100mm increase in spacer length. The decrease in friction factor is nearly two times lower than the full length helical twist at low Reynolds number, and four times lower than the full length ...

Energy Technology Data Exchange (ETDEWEB)

This research investigated the influence of stearic acid on the injection molding of alumina, by varying the concentration of stearic acid. The interaction between stearic acid and alumina was identified using transmission infrared spectroscopy, indicating stearic acid preferentially adsorbed onto the alumina powder surface. In addition to slightly modifying the intrinsic binder viscosity, stearic acid adsorbed onto the powder surface changed the flow behavior of the mixtures from dilatant flow to pseudoplastic flow at low temperatures. As a result, inhomogeneous distribution of binder in the injection-molded parts was minimized with increased stearic acid concentration. However, the possibility of forming bubbles in the mixtures arising from vaporization of stearic acid was enhanced. Additionally, the binder burnout temperature range was broadened with the increase of stearic acid concentration.

Science.gov (United States)

Applying an underfeed system, the underfeed circulating spouted bed was designed as a desulfurization reactor. The main objective of the technology is to improve the mixing effect and distribution uniformity of solid particles, and therefore to advance the desulfurization efficiency and calcium utility. In this article, a series of experimental studies were conducted to investigate the fluidization behavior of the solid-gas two-phase flow in the riser. The results show that the technology can distinctly improve the distribution of gas velocity and particle flux on sections compared with the facefeed style. Analysis of pressure fluctuation signals indicates that the operation parameters have significant influence on the flow field in the reaction bed. The existence of injecting flow near the underfeed nozzle has an evident effect on strengthening the particle mixing.

Energy Technology Data Exchange (ETDEWEB)

Three dimensional computational fluid dynamic (CFD) calculations of a typical prismatic very high temperature gas-cooled reactor (VHTR) were conducted to investigate the influence of gap geometry on flow and temperature distributions in the reactor core using commercial CFD code FLUENT. Parametric calculations changing the gap width in a whole core length model of fuel and reflector columns were performed. The simulations show the effects of core by-pass flows in the heated core region by comparing results for several gap widths including zero gap width. The calculation results underline the importance of considering inter-column gap width for the evaluation of maximum fuel temperatures and temperature gradients in fuel blocks. In addition, it is shown that temperatures of core outlet flow from gaps and channels are strongly affected by the gap width of by-pass flow in the reactor ...

Energy Technology Data Exchange (ETDEWEB)

The aerodynamic forces and wake structure of the non-rotating downstream circular cylinder, of which the uniform free stream flow is interfered with another spinning upstream cylinder having the same diameter that is located upstream in a line have been investigated experimentally. When the spin rate of the downstream cylinder defined as the ratio of tangential surface velocity of the spinning cylinder to the free stream velocity increases gradually from zero to 1.4, the change of surface pressure distribution, aerodynamic forces of the non-rotating downstream cylinder were measured in case of several distance ratios of 1.5, 3.0, and 4.5 defined as the ratio of distance between the centers of two cylinders to the diameter. The wake flow patterns behind the cylinder were also investigated in each case. From the present experiments, it has been found that the spin rate significantly influences the aerodynamic forces and ...

Energy Technology Data Exchange (ETDEWEB)

Details are given of the Sasol operation in South Africa. Flow sheets are provided for Sasol 1 and Sasol 2 and 3. The Sasol 1 plant produces waxes, liquid fuels, pipeline gas and chemicals; the Sasol 2 and 3 plants primarily produce ethylene, gasoline and diesel fuel. The versatility of the process is emphasized. The product selectivities of the fixed bed and Synthol reactors are shown and the properties of the products are compared. The influence of the catalyst on selectivity is examined.

Energy Technology Data Exchange (ETDEWEB)

Four subprojects were completed: development and evaluation of die coatings, accelerated die life characterization of die materials, evaluation of fluid flow and solidification modeling programs, selection and characterization of Al-based die casting alloys, and influence of die materials and coatings on die casting quality.

British Library Electronic Table of Contents (United Kingdom)

In the field of international human resource management, studies have seldom examined organizational justice, social exchange, and psychological contract together as important factors in influencing the expatriate adjustment process. The purpose of this research is to fill the research gap by examining these factors and their relationships with expatriate adjustment. The researcher conducted a survey of Taiwanese business expatriates during the first quarter of 2007, collecting 219 valid samples for analysis. A hierarchical regression model was used to test the research framework hypotheses, which showed that expatriates' perception of organizational justice has a positive influence both on their perceptions of social exchange and on their psychological contract fulfillment. Expatriates' p...

International Nuclear Information System (INIS)

In this study based on the mass transfer theory, experiments for the evaporation rates depending on various conditions were carried out through the operation of the existing Natural Evaporation Facility in KAERI. Evaporation media were made of the cotton and polyester. Air circulation in the facility was forced by exhausting fans. The evaporation rate and the decontamination factor were calculated by the result of experiment. The evaporation rate increased as the flow rate of air supply, the feed rate of liquid waste, and the temperature of supplied air increased. As for the humility of supplied air, the evaporation rate was getting higher as the humidity was getting lower. As the result of this study, operation conditions of the Natural Evaporation Facility are optimized as follows; The air temperature above 8C .deg., the air humidity below 70%, the air flow rate 1.14-1.47 m/sec, and the liquid waste feed rate 4.6l/hr.m"2. ...

Energy Technology Data Exchange (ETDEWEB)

Film boiling is the mode if boiling during which the hot surface is separated from the vaporizing liquid by a nearly continuous film vapor. Film boiling is usually considered a very undesirable boiling regime since it is a relatively quiet and inefficient mode of heat transfer, particularly as compared to nucleate boiling. It is customary to analyze the two-phase flow regime of laminar flow film boiling by assuming the two-phase flow regime of laminar flow film boiling by assuming an idealized vapor film flow characterized by a smooth liquid-vapor interface. However, during stable flow film boiling, the wavy nature of the liquid-vapor interface and its role in local heat and mass transport have been largely ignored. The vapor interface is rarely stationary. Interfacial waves may substantially augment the heat transfer rates throughout the layer. The present ...

British Library Electronic Table of Contents (United Kingdom)

Information technology allows national and local governments to satisfy the needs of citizens in a cost effective way. Unfortunately, citizens still tend to prefer traditional, more costly channels, such as the front desk, phone and mail. Through pilot projects government agencies attempt to influence this behavior of citizens, directing them towards the online channel. With this paper we provide insight into the possibility to influence citizens' behavior in the complex landscape of multi-channel service provision. The paper systematically compares five pilot projects using a framework that is based on organizational and marketing literature. The results show that socio-psychological factors are crucial in multi-channel management, much more than the technology itself. We conclude that ci...

International Nuclear Information System (INIS)

Scattered radiation generated in patient and imaging system has to be considered when quality-assurance tests involve dose detection or image-quality estimations. Measurement of automatic-exposure control dose can be altered by backscattering from intensifying screens of more than 10% and the equipment transmission factor can be overestimated up to a factor of 10 when only primary radiation is used. The sensitivity of intensifying screens depends on the angle of incidence of the radiation and so primary and scattered radiation are detected differently. The quality-control aspects of anti-scatter grids are discussed. (author).

CERN Document Server

Knowledge management is controlling the transfer, distribution, and availability of knowledge. Traditionally, knowledge management processes are predefined; e.g. it is laid out in detail which document template, data structure, system, or work flow steps have to be used in order to manage knowledge. But knowledge management itself is complex. It is simply not possible to predefine the typical flow of work in knowledge intensive processes in advance. So rather than trying to determine the procedures it is more promising to analyze which factors can be used in order to control the outcome of t

Science.gov (United States)

Enhanced heat transfer in curved rectangular channels depends on at least two geometric factors, the radius of curvature of the duct and the aspect ratio, which is the width/depth ratio of the duct. In this work, an expression for optimum aspect ratio is derived mathematically from a correlation that includes both aspect ratio and bend curvature parameters. Enhancement factors are developed that show optimal, near-optimal, and nonoptimal aspect ratios for curved rectangular ducts. Predicted enhancements are within 25% of published literature results for individual designs, two of which show heat transfer enhancement of 200% over that of a straight duct with turbulent flow. The theoretical maximum enhancement is shown to be about 480% over a straight-duct, turbulent-flow situation. This is not achievable in practice, but near-optimal solutions are achievable, yielding enhancements on the order of ...

Energy Technology Data Exchange (ETDEWEB)

A two-cycle process using O{Phi}CMPO and HDEHP as extractants to achieve an alpha decontamination factor of HLLW greater than 10{sup 3} together with a reduction of the lanthanides/americium weight ratio by a factor of about 200 is considered. Experimentally measured distribution ratios have been employed as input data of a suitable computer code to define operating conditions and M/S stage numbers of a process flow-sheet able to meet the above-mentioned objectives.

British Library Electronic Table of Contents (United Kingdom)

A numerical study has been conducted to examine the heat transfer from a metal foam-wrapped solid cylinder in cross-flow. Effects of the key parameters including the free stream velocity and characteristics of metal foam such as porosity, permeability, and form drag coefficient on heat and fluid flow are examined. Being a determining factor in pressure drop and heat transfer increment, the porous layer thickness is changed systematically to observe that there is an optimum layer thickness beyond which the heat transfer does not improve while the pressure drop continues to increase. This has been verified by the application of Bejan?s Intersection of Asymptotes method. Results have been compared to those of a finned-tube heat exchanger to observe much higher heat transfer rate with reasonab...

Energy Technology Data Exchange (ETDEWEB)

In a breeder-type nuclear power plant, liquid metal is used as a coolant due to the high heat capacity factor. Also, some proposals for fusion reactor blanket design include liquid metal as a possible coolant. In both cases the understanding of natural circulation of liquid-metal flow behavior is an integral part of the thermal hydraulic analysis, especially under two-phase flow conditions. Experimental investigations have been conducted to study a liquid metal two-phase natural circulation flow system. A lead-bismuth (PbBi) eutectic mixture is used as a working fluid in a heated metal walled natural circulation loop. Gas injection induces natural circulation through the gas-lift mechanism. A real-time neutron radiography system is used to visualize the two-phase mixture, specifically the interface and the flow regime. Measurements of void fraction, void fluctuation and bubble ...

Energy Technology Data Exchange (ETDEWEB)

The two-phase heat-transfer and pressure-drop characteristics of offset-strip-fin heat-exchanger geometries are examined using both experimental and analytical modeling techniques. Newly-obtained boiling-flow heat-transfer data are presented for two large-scale offset fin geometries at low-to-moderate wall-superheat conditions. Data for which nucleate boiling appeared to be completely suppressed were analyzed together with similar results for other offset fin surfaces to study the effects of channel dimensions on the convective evaporation component of the local heat transfer coefficient. Although these data were found to be well correlated in terms of modified forms of the F and Martinelli parameters used in previous studies of round-tube flows, a single F-factor correlation valid for all combinations of fin and channel dimensions did not appear to exist. The two-phase pressure-drop characteristics of offset-fin surfaces ...

Energy Technology Data Exchange (ETDEWEB)

A unique method, previously proposed by the author, was applied to the heat transfer augmentation in the flow boiling field. In this method a screen sheet was put on the horizontal heated surface where bubble nucleation occurred. Generated vapor bubbles were trapped between the screen and the wall, became flat and moved along the surface. This restricted bubble behavior caused the heat transfer enhancement. Three types of the screen were tested in the present experiment and the effect of the screen was investigated on the heat transfer and two-phase flow characteristics. In two cases of them, the screen was displaced upward by the bubble nucleation. Compared with the ordinary flow boiling case, heat transfer was enhanced by a factor of 1.2 to 6 within the present experimental range. By using a simple flow model, it was made clear that the effect of the height of the displaced screen ...

Energy Technology Data Exchange (ETDEWEB)

Plasma arc welding processes are used in off-shore industry for construction and maintenance in the wet surrounding of underwater structures and pipelines. In greater water depth the density of the plasma gas increase because of the greater hydrostatic pressure. This causes the increase of conductive heat losses to the wet surrounding. To keep up the energy flux to the workpiece to be welded, the plasma arc has to burn in a local dry area with an inside pressure of 1 bar. This requirement can be fulfilled by a rotating cylinder with a liquid film flowing down the inner wall. The flow around the rotating cylinder to create a local dry area around the plasma arc under water is experimentally investigated. The rotating cylinder is placed above the work surface which is simulated by a flat plate. According to the centrifugal forces of the rotating flow inside the gap between the lower end of the cylinder and the flat plate the ...

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)

Energy Technology Data Exchange (ETDEWEB)

In this article, the authors recall the factors apt to influence image quality in NMR Imaging and present the european works that have been developed in MRIQA to set 5 quality assurance tests: EUROSPIN 1 to 5.

International Nuclear Information System (INIS)

It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

International Nuclear Information System (INIS)

The Moessbauer emission spectrum of "2"4"1Am metal was investigated for influences of radiation self damage. Samples were kept continuously for 230 h at 4.2 K and spectra were taken each 10 to 20 h. No change in f-factor was observed, while the linewidth increased monotonically and reached saturation after approximately 180 h. The original width could be reproduced by a brief warming to room temperature. The increase in width reflects the change in quadrupole interaction due to the creation of lattice defects. The constancy of the f-factor indicates that the basic crystalline structure is retained.

CERN Document Server

In this paper we will report on the operation and the performance of the ATLAS data-flow system during the 2010 physics run of the Large Hadron Collider (LHC) at 7TeV. The data-flow system is responsible for reading out, formatting and conveying the event data, eventually saving the selected events into the mass storage. By the second quarter of 2010, for the first time, the system will be capable of the full event building capacity and improved data-logging throughput. We will in particular detail the tools put in place to predict and track the system working point, with the aim of optimizing the bandwidth and the computing resource sharing, and anticipate possible limits. Naturally, the LHC duty cycle, the trigger performance, and the detector configuration influence the system working point. Therefore, numerical studies of the data-flow system capabilities have been performed considering different ...

International Nuclear Information System (INIS)

A new miniature high-frequency (HF) plasma source intended for bio-medical applications is studied using nitrogen/oxygen mixture at atmospheric pressure. This plasma source can be used as an element of a plasma source array for applications in dermatology and surgery. Nitric oxide and ozone which are produced in this plasma source are well-known agents for proliferation of the cells, inhalation therapy for newborn infants, disinfection of wounds and blood ozonation. Using optical emission spectroscopy, microphotography and numerical simulation, the gas temperature in the active plasma region and plasma parameters (electron density and electron distribution function) are determined for varied nitrogen/oxygen flows. The influence of the gas flows on the plasma conditions is studied. Ozone and nitric oxide concentrations in the effluent of the plasma source are measured using absorption spectroscopy and electro-chemical ...

British Library Electronic Table of Contents (United Kingdom)

Keratinocyte growth factor receptor (KGFR) and fibroblast growth factor receptor (FGFR) 2c share identical amino acid sequences, except for a 46-amino acid domain in the extracellular region. Monoclonal antibodies (MAbs) specific to KGFR have not been reported nor are commercially available. In this study, we generated murine MAbs specific to KGFR in non-obese diabetic (NOD) mice using a modified Repeated Immunizations at Multiple Sites (RIMMS) technology. Stable cell lines expressing the full-length human KGFR or FGFR2c were produced to facilitate the identification of KGFR-specific MAbs. Following the initial screening of hybridoma clones with a fluorescence-based, confocal cell detection method and ELISA, KGFR-specific MAbs were selected and confirmed by flow cytometry and Western blot ...

Energy Technology Data Exchange (ETDEWEB)

The Filtra-MVSS for filtered venting of containment overpressure is a flexible system capable of covering a wide range of hypothetical design basis events for BWRs and PWRs. The system encompasses a number of special features, can be optimized for a specified decontamination factor, and can accommodate a wide range of off-gas flow rates.

British Library Electronic Table of Contents (United Kingdom)

For optimal performances, proton exchange membrane fuel cells require fine water and thermal management. Accurate modelling of the physical phenomena occurring in the fuel cell is a key issue to improve fuel cell technology. Here, an analytic steady state diphasic 2D model of heat and mass transfer is presented. Through this model, the aim of this work is to study the influence of local events on the global performances of a fuel cell. A part of the complete model is a microscopic representation of the coupling between water transport and charge transfers in the electrodes. The thickness of the liquid layer around the reactive agglomerates is deduced from the saturation. The evolution of the quantity of water within the catalyst layer is monitored and its influence on the global performanc...

International Nuclear Information System (INIS)

Fly ash from Lagisza power station with addition of kaolin and calculated amount of carbon was reacted in flowing nitrogen at 1520"oC in order to obtain #beta#-sialon. The resulted powder was sintered with and without Y_2O_3 addition. Examinations show that it is possible to sinter that material without any sintering additives, however additive of Y_2O_3 decreases sintering temperature of about 100"oC. Sintering temperature influences the final mechanical properties like: flexural strength, microhardness, Young elastic modulus (E) and fracture toughness (K_I_c). (author)

Energy Technology Data Exchange (ETDEWEB)

Measurements of smoke and NO emissions from a direct-injection diesel engine have shown that they are indeed influenced by inlet port design, even though the swirl numbers for the ports may be identical. The swirl numbers of the three ports used (tangential port, helical port and helical port with masked valve) were measured on a steady-state test rig using a paddle-wheel anemometer and impulse swirl meter. Flow measurements were carried out under motoring conditions with a constant-temperature, hot-wire anemometer. Is was possible to find a correlation between flow data and exhaust data as far as the in-cylinder air motion over a certain time interval is concerned.

International Nuclear Information System (INIS)

To evaluate safety of horizontal steam generator used in passive safety system, it is needed to make clear flooding characteristics in U bend pipe. In this study, two-phase flow experiment in a horizontal U bend pipe was carried out to make clear the influence of the length of horizontal pipe and the radius of U bend. Flooding in the U bend pipe was observed in the condition of lower gas or liquid volumetric flux than that in the horizontal pipe or the vertical pipe. Flooding and carry-up in the U bend pipe is hardly change with increasing the length between the water inlet and the U bend, but greatly related with the length from the water inlet to the lower tank and the shape of the U bend inlet. (author).

Energy Technology Data Exchange (ETDEWEB)

The catalytically stabilised thermal combustion (CST) of lean hydrogen-air mixtures was investigated numerically in a turbulent channel flow configuration using a two-dimensional elliptic model with detailed heterogeneous and homogeneous chemical reactions. Comparison between turbulent and laminar cases having the same incoming mean properties shows that turbulence inhibits homogeneous ignition due to increased heat transport away from the near-wall layer. The peak root-mean-square temperature and species fluctuations are always located outside the extent of the homogeneous reaction zone indicating that thermochemical fluctuations have no significant influence on gaseous combustion. (author) 4 figs., 6 refs.

International Nuclear Information System (INIS)

Heat transfer augmentation in narrow rectangular channels in a target system is a very important method to remove high heat flux up to 12 MW/m"2 generated at target plates of a high-intensity proton accelerator of 1.5 GeV and 1 mA with a proton beam power of 1.5 MW. In this report, heat transfer coefficients and friction factors in narrow rectangular channels with one-sided rib-roughened surface were evaluated for fully developed flows in the range of the Reynolds number from 6,000 to 1,00,000; the rib pitch-to-height ratios (p/k) were 10,20 and 30; the rib height-to-equivalent diameter ratios (k/De) were 0.025, 0.03 and 0.1 by means of previous existing experimental correlations. The rib-roughened surface augmented heat transfer coefficients approximately 4 times higher than the smooth surface at Re=10,000, p/k=10 and k/De=0.1; friction factors increase around 22 times higher. In this case, higher heat flux up to 12 MW/m"2 ...

International Nuclear Information System (INIS)

Saturated flow boiling and convective condensation experiments for oil-free refrigerant R22 been carried out with a micro fin tube of new design and with a smooth tube. Both tube have the same outer diameter of 9.52 mm and are horizontally operated. Two-phase flow pattern data have been obtained in addition of heat transfer coefficient and pressure drops; more-over, adiabatic tests have been also performed in order for flow pattern map to cover even adiabatic flows. Data are for mass fluxes ranging from about 90 to 400 Kg/s m"2. In boiling tests, the nominal saturation temperature is 5 degree C, with inlet quality varying from 0.2 to 0.6 and the quality change ranging from 0.1 to 0.5. In condensation, results are for saturation temperature equal to 35 degree C, with inlet quality between 0.8 and 0.4, and quality change within 0.6 and 0.2. The comparison shows a large heat transfer augmentation with a ...

Energy Technology Data Exchange (ETDEWEB)

A numerical investigation of a humidification dehumidification desalination (HDD) process using solar energy is presented. The HDD system consists mainly of a concentrating solar water heating collector, flat plate solar air heating collector, humidifying tower and dehumidifying exchanger. Two separate circulating loops constitute the HDD system, the first for heating the feed water and the second for heating air. A mathematical model is developed, simulating the HDD system, to study the influence of the different system configurations, weather and operating conditions on the system productivity. The model validity is examined by comparing the theoretical and experimental results of the same authors. It is found that the results of the developed mathematical model are in good agreement with the experimental results and other published works. The results show also that the productivity of the unit is strongly influenced by the air ...

Energy Technology Data Exchange (ETDEWEB)

Squeeze film dampers (SFD) are devices utilized to control vibrations of the shafts of high-speed rotating machinery. The SFD - squirrel cage combination is probably the most used system for tuning the stiffness and damping of the supports for rotors installed on ball bearings. Squeeze film dampers are essentially hydrodynamic bearings which contain the ball bearings housings of ball-bearings supported shafts. Consequently, the oil film within the SFD are influenced only by the precession and nutation of the shaft, that is the flow of the oil within the damper is not directly influenced by the spin of the rotor. However, in the classical theory, the flow in the thin film is also governed by the Reynolds equation. In this paper, some of the limits of the classical theory of the SFD are discussed and theoretical and experimental studies, which illustrate the ideas presented herein, are presented as well. ...

Energy Technology Data Exchange (ETDEWEB)

The Idaho National Engineering Laboratory (INEL) has been conducting geothermal reservoir research and testing sponsored by the US Department of Energy (DOE) since 1983. The INEL research program is primarily aimed at the development of reservoir engineering techniques for fractured geothermal reservoirs. Numerical methods have been developed which allow the simulation of fluid flow and heat transfer in complex fractured reservoirs. Sensitivity studies have illustrated the importance of incorporating the influence of fractures in reservoir simulations. Related efforts include fracture characterization, geochemical reaction kinetics and field testing.

Science.gov (United States)

This case study, conducted from an interpretive paradigm, illuminates contextual factors related to the tutor experience when senior undergraduate dental hygiene students served as tutors for beginning undergraduate dental hygiene students, or sophomores, in a 1-semester, 2-hour long problem-based learning (PBL) course in a Baccalaureate Dental Hygiene (BDH) curriculum during the spring semester of 2008. Data were collected using various sources and methods. Six tutors and three administrators were interviewed, tutees completed an anonymous questionnaire, the tutorial process and tutor training sessions were observed, and related documents were examined. Data analysis included open and axial coding, creation of tutor profiles, and identification of patterns. Tutor behaviors varied with respect to the nature of intervention (e.g., telling, asking, clarifying, acknowledging), emphasis (process, content, social), and facilitation style (directive, suggestive, ...

British Library Electronic Table of Contents (United Kingdom)

In this work, the antibacterial effect of fluoroquinolones (FQs) upon Escherichia coli (E.coli) was measured with and without application of 40kHz ultrasound (US) stimulation. The research results demonstrated that simultaneous application of 40kHz US apparently enhanced the antibacterial effectiveness of FQs. That is, the synergistic effect was observed and the bacterial viability was reduced when FQs and US were combined. In addition, various influencing factors, such as FQs drug concentration, US irradiation time and solution temperature, on the inhibition of E.coli were also investigated. The antibacterial activity was enhanced apparently with increasing of FQs drug concentration, US irradiation time and solution temperature. Furthermore, we discussed preliminarily the mechanism of US ...

British Library Electronic Table of Contents (United Kingdom)

Perceptions of sensation and pain in healthy people are believed to be the net result of sensory input and descending modulation from brainstem and cortical regions depending on emotional and cognitive factors. Here, the influence of attention on neural activity in the spinal cord during thermal sensory stimulation of the hand was investigated with functional magnetic resonance imaging by systematically varying the participants' attention focus across and within repeated studies. Attention states included (1) attention to the stimulus by rating the sensation and (2) attention away from the stimulus by performing various mental tasks of watching a movie and identifying characters, detecting the direction of coherently moving dots within a randomly moving visual field and answering mentally-...

Energy Technology Data Exchange (ETDEWEB)

The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi/m/sup 2/ s by application of covering layers of soils and clays. These covers present a radon diffusion barrier, which sufficiently increases the time required for radon passage from the tailings to the atmosphere to allow for decay of /sup 222/Rn within the cover. The depth of cover necessary to reduce the escaping radon flux to the prescribed level is to be determined by calculation, and requires precise knowledge of the radon diffusion coefficient in the covering media. A Radon Attenuation Test Facility was developed to determine rates of radon diffusion through candidate cover materials. This paper describes this facility and its application for determining the influence of physical properties of the soil column on the radon diffusion coefficient.

CERN Document Server

Multiphase reacting flows

Energy Technology Data Exchange (ETDEWEB)

There are few studies on coke's micro-pore structure in recent years, however, micro-pore structure of foundry coke determines its macroscopically quality index and reactivity in cupola furnace. Effect of such factors on micro-pore structure were investigated under different carbonization conditions with certain ratio of raw materials and material forming process in this article as charging temperature (A); braised furnace time (B); heating rate of the first stage (C)and the second stage (D) and holding time of ultimate temperature (E). Research showed that charging temperature was the most influential factor on the coke porosity, pore volume, pore size and specific surface area. It is suggested that formation of plastic mass and releasing rate of volatile during carbonization period are two main factors on microstructure of foundry coke while charging temperature contributes most to the above ...

International Nuclear Information System (INIS)

The aim of this paper is to investigate the fluid dynamic behaviour of a commercial hydraulic proportional valve in order to evaluate and justify its global performances and, in particular, to analyze the effects of some additional design features on the reduction of the force required to maintain the valve open. The proposed analysis has been performed by applying the commercial computational fluid dynamics (CFD) code, Fluent, to the solution of the three dimensional turbulent flow field through a circumferential sector of the entire valve for different spool strokes. The reliability of the employed modelization is demonstrated by the comparison between the computed flow rate curve and the corresponding experimental data provided by the manufacturer. With regard to the metering edge design, it is shown that the cylindrical hole provided on the top of the hemi-spherical notch to improve metering at small valve openings has no ...

International Nuclear Information System (INIS)

As part of on-going study of acid mine drainage (AMD), a comprehensive ecological risk assessment was conducted in the Leading Creek Watershed in southeast Ohio. The watershed is influenced by agriculture and active and abandoned coal-mining operations. This work presents a broad overview of several quantitative measures of hydrology and hydraulic watershed properties available for in risk assessment and evaluates their relation to metrics of ecology. Data analysis included statistical comparisons of metrics of ecology, ecotoxicology, water quality, and physically based parameters describing land use, geomorphology, flow, velocity, and particle size. A multiple regression analysis indicated that abandoned mining operations dominated impacts upon aquatic ecology. It also indicated low flow velocity measurements and a ratio of maximum velocity to average velocity at low flow where helpful in describing ...

Energy Technology Data Exchange (ETDEWEB)

A one-way coupling system between the plant simulator TRAC/BF1-ENTREE and the subchannel code with the improved cross flow model, NASCA, has been developed. Based on a scenario of turbine trip tests in the Peach Bottom Unit 2, the wide and rapid reactivity insertion transient induced by the system pressure rise was calculated. The pin power distribution in hot bundles was re-constructed considering heterogeneity of the fuel bundle. When the neighboring control blade is withdrawn, NASCA predicted that the steady-state bundle exit void distribution was nearly flat with regardless of the pin power distribution. However, void distributions in the middle and lower bundle regions became complicated depending on the pin power and the two-phase flow regime in each subchannel. The pin power distribution rapidly changed according to traveling of control blades. However, influence in the void distribution was delayed and damped due to ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

An experimental study of forced convection heat transfer at the inner tube wall of a double pipe heat exchanger with coiled wire inserts as heat transfer augmentation devices was performed over a turbulent flow region. The test results from twelve augmented tubes with inserts of different combinations of wire diameters (0.813, 1.016 and 1.575 mm) and pitches (2.82, 3.63, 5.08 and 8.47 mm) indicate that the turbulence promoters studied improve heat transfer by a factor of 1.4 to 2.24 compared with a smooth tube, although at a cost of 10-30 times increase in friction factor. A formula for presenting dimensionless exergy losses in a tubular heat exchanger is derived first and then the thermohydrodynamic optimum instead of economic optimum is found by minimizing the exergy losses in the system. From the heat transfer improvement number defined, it is observed that coiled wire turbulence promoters are more effective at Reynolds ...

British Library Electronic Table of Contents (United Kingdom)

A solvent extraction method was developed to obtain methanolic extracts rich in antioxidants from banana peel. Central composite design ''2^3+star'' and response surface methodology were used in order to optimise the number of extraction steps, extraction temperature and extraction time. The number of extractions was statistically the most significant factor in scavenging activity against both DPPH? and ABTS?^+ radicals and in the inhibition of TBARS formation, while the extraction temperature had an important impact on the capacity to prevent b-carotene bleaching. However, the effect of the extraction time on antioxidant activity was less important. The optimum values of the factors that influence the capacity to scavenge DPPH? and ABTS?^+ radicals or to inhibit b-carotene bleaching were ...

Energy Technology Data Exchange (ETDEWEB)

A variety of observations suggest that the Universe had a hot dense origin and that the pregalactic composition of the Universe was determined by nuclear reactions that occurred in the first few minutes. There is no unique hot Big Bang theory, but the simplest version produces a primeval chemical composition that is in good qualitative agreement with the abundances deduced from observation. Whether or not any Big Bang theory will provide quantitative agreement with observations depends on a variety of factors in elementary particle physics (number and masses of stable or long-lived particles, half-life of neutron, structure of grand unified theories) and from observational astronomy (present mean baryon density of the Universe, the Hubble constant and deceleration parameter). The influence of these factors on the abundances is discussed, as is the effect of departures from homogeneity and isotropy in the early Universe.

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the application of a Computational Fluid Dynamics (CFD) code (FLUENT) to predict temperature and velocity profiles, and particle trajectories in an industrial fired by a low NO{sub x} pulverized coal swirl burner. The predictions of the code were compared to experimental measurements of gas temperature, particle size distribution, and particle velocities. The diagnostics employed were a suction pyrometer and a Particle Counter Sizer Velocimeter Probe (PCSV-P). Good agreement was found between the temperature predictions and the measurements. In situ particle size distributions were predicted accurately using the Baum and Street model with a swelling factor of zero. The numerical modeling indicated that the Type II flow issued from the burner could be transformed into Type III flow, by eliminating swirl from the primary air stream, which provided the preferred particle trajectories and increased the ...

British Library Electronic Table of Contents (United Kingdom)

Detailed geothermal studies of deep drill holes provide insights to heat transfer processes in the crust, and allow separation of different factors involved, such as palaeoclimatic and structural conductive effects as well as advective fluid flow effects. We present high resolution geothermal results of the 2516m deep Outokumpu Deep Drill Hole in eastern Finland drilled in 2004-2005 into a Palaeoproterozoic formation with metasedimentary rocks, ophiolite-derived altered ultramafic rocks and pegmatitic granite. The down-hole temperatures have been logged five times after end of drilling and extend to day 948 after drilling. The hole is completely cored (79% core coverage) and thermal conductivity measurements were done at 1m intervals. The geothermal results on temperature gradient, thermal...

Energy Technology Data Exchange (ETDEWEB)

In this work, a comprehensive model has been developed for the absorption of carbon dioxide into promoted hot potassium carbonate solution. The model, which is based on penetration theory, incorporates an extensive set of important reactions and takes into account the coupling between mass transfer and chemical kinetics. The penetration theory provides an appropriate absorption rate and enhancement factor for the chemical absorption. Operating data for carbon dioxide absorption into DEA-hot potassium carbonate solution has been compared with model predictions. The impact of parameters such inlet temperature of lean solution, promoter concentration, liquid split fraction, hot feed location and type of promoter on the performance of a split-flow absorber have been examined. The use of other promoters is an efficient way to enhance the carbon dioxide absorption, which has been discussed in this paper.

Energy Technology Data Exchange (ETDEWEB)

An analysis of the passive films formed on amorphous alloys of the system Fe-10% Cr-5% Mo-P-metalloid and Fe-10% Cr-5% Mo-B-Si revealed that they are more markedly enriched with chromium in silicon-free alloys. In silicon-containing amorphous alloys the passive films were highly enriched with silicon, which occurred in these films in the form of a corrosion product close to SiO/sub 2/. As shown by the investigations of a study of the anodic behavior of Fe/sub 40/Ni/sub 40/P/sub 14/B/sub 6/ and Fe/sub 40/Ni/sub 38/Mo/sub 4/B/sub 18/, phosphorus facilitates the passivation of amorphous alloys by reducing the solution current in the active state and enriching the surface layers of the metal in the form of a black prepassivation film which also contains nickel and iron. The behavior of Fe-Ni amorphous alloys containing only boron as metalloid additive differs little from that of crystalline alloys of similar composition but without the boron. The authors note that in this survey they have ...

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 ...

CERN Document Server

Not long ago primary census data became available to publicity. It opened qualitatively new perspectives not only for researchers in demography and sociology, but also for those people, who somehow face processes occurring in society. In this paper authors propose using Data Mining methods for searching hidden patterns in census data. A novel clustering-based technique is described as well. It allows determining factors which influence people behavior, in particular decision-making process (as an example, a decision whether to have a baby or not). Proposed technique is based on clustering a set of respondents, for whom a certain event have already happened (for instance, a baby was born), and discovering clusters' prototypes from a set of respondents, for whom this event hasn't occurred yet. By means of analyzing clusters' and their prototypes' characteristics it is possible to identify which factors ...

Energy Technology Data Exchange (ETDEWEB)

In the groundwater flow modelling part of this work the effective dilution volume in the well scenario was estimated by means of transient simulations of groundwater flow and transport, which are coupled due to the varying salinity. Both deep, drilled wells and shallow surface wells in the vicinity of the repository were considered. The simulations covered the time period from the present to 1000 years after the present. Conceptually the fractured bedrock consists of planar fracture zones (with a high fracture density and a greater ability to conduct water) and the intact rock (in which the fracture density and the hydraulic conductivity are low). For them the equivalent-continuum model was applied separately. Thus, the fractured bedrock was considered as piecewise homogeneous (except for the depth dependence) and isotropic continuum with representative average characteristics. A generic simulation model for groundwater ...

International Nuclear Information System (INIS)

The influence of the main factors on device efficiency of pulsed liquid jet pump with gas-liquid piston is analysed, the theoretical equation and its time-averaged solution of pulsed liquid jet pump device efficiency are derived. The theoretical and experimental results show that the efficiency of transmission of energy and mass to use pulsed jet is greatly raised, compared with steady jet, in the same device of liquid jet pump. The calculating results of time-averaged efficiency of pulsed liquid jet pump are approximately in agreement with the experimental results in our and foreign countries

Energy Technology Data Exchange (ETDEWEB)

Factors influencing the rooting-potential of stem cuttings of conifers were studied for the purpose of improving methods of rapid vegetative propagation. Within the bounds of hereditary limits, root regeneration depends, to a considerable extent, on the qualities of rooting-media, date of cutting excision, age and physiological conditions of the stock plant, age of the cutting-wood, its position on the plant, and chemical treatment. Hardwood cuttings, which have a relatively high content of endogenous auxin and carbohydrates, and morphological root initials, gave the best results. This method made it possible to increase the growth rate of cuttings 2.5-5 times that of cuttings taken from shoots of current growth. (Refs. 21).

International Nuclear Information System (INIS)

Presented are the results of the investigation of the kinetics and micromechanism of the failure in impact bending of oriented-crystallized specimens having the eutectic composition Ni_3Al-Ni_3Nb and of the bimetal composed of 45 steel + M3 copper. The failure kinetics was studied by high-speed filming, whereas the fractures were studied by electron fractography. The particularities of the failure of the laminar-type composite materials were found. Analyzed was the effect of the kinetic factors and the mechanism of failure upon its energy consumption.

British Library Electronic Table of Contents (United Kingdom)

This research investigates the impact of national culture and several institutional factors on the safety performance of society and establishes statistically significant relationships between those variables. As expected, the research results reveal that some cultural variables such as uncertainty avoidance, gender orientation and institutional variables such as the degree of law avoidance can directly influence the safety performance of the society. The findings also support the inverted u-curve (Safety Kuznet curve) hypothesis indicating even if we expect a negative trend at the beginning stage of industrialization, we can expect a positive trend in safety performance as their income level continues to improve beyond a certain point.

Science.gov (United States)

We proposed and numerically investigated the influence of spatial symmetry on the terahertz frequency region response of composite planar metamaterials based on deformed split ring resonators. Compared with the original simple structures, the composite metamaterials with different spatial symmetries exhibited exotic electromagnetic properties. The electromagnetic response of a specific configuration with C4 symmetry was identical to the structure with simple lattice. Especially, for configurations with broken symmetry, very sharp Drude-like resonances with high quality factor were observed. The electric field and current distribution associated the resonances were analyzed for deep understanding of the underlying physical properties.

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.

Energy Technology Data Exchange (ETDEWEB)

Discusses methods for determining ash content in coal using backscattering in X-ray fluorescence. The following aspects are evaluated: principle of ash content determination, energy sources, factors that influence measurement accuracy, reliability. Types of X-ray fluorescence analyzers developed in Czechoslovakia and manufactured in the Czech Republic are comparatively evaluated. Operation of the RPM 113.1 radionuclide X-ray fluorescence analyzer developed by the PAR company and used for measuring ash content in coal and coal calorific value is discussed. 7 refs.

International Nuclear Information System (INIS)

This work presents analsysi of the eddy current brake. It presents a new formula for the braking force when the actual width of the pole is considered. This formula is suitable for both thin and thick discs and may be employed for wide range of working speed. This force is obtained by solving a two dimensional field problem for magnetic vector potential and then by employing Lorentz force equation. A comture program is constructed to calculate the braking force and to study the effect of various factors influencing the brake performance. The results are summarised in a group of curves which may be useful for design purposes.

British Library Electronic Table of Contents (United Kingdom)

Anesthetic techniques vary widely in the endovascular repair of abdominal aortic aneurysms (EVAR). Previous studies have demonstrated the feasibility of using local anesthesia. However, the ideal anesthetic technique has not been determined. This study examines whether anesthesic technique influences the outcomes of EVAR. Data regarding demographics, risk factors, procedural characteristics, recovery characteristics, treatment complications, acute ( 0.05, ANOVA). From these results we concluded that EVAR with local anesthesia is a safe and efficacious method that may reduce recovery times and postoperative medical morbidity compared to use of genera1 or spinal/epidural anesthesia.

Energy Technology Data Exchange (ETDEWEB)

This paper reported on a study that evaluated the energy consumption of cotton gins used in Australia. The average electricity use is 52.3 kWh per bale. In practicality, the electricity consumption for different gins is correlated linearly with the bale numbers produced. The cost of electricity is therefore important in cotton ginning operations. The power factor in all the gins monitored in this study was greater than 0.85. The study showed that the use of gas dryers was highly influenced by the cotton moisture and regulated drying temperature. In general, electricity and gas consumption comprised 61 and 39 per cent of total energy use respectively. The study showed that 60.38 kg of carbon dioxide are emitted for ginning each bale of cotton. This paper described a newly developed method for monitoring the energy performance in cotton gins. Detailed monitoring and analysis carried out at 2 gin sites revealed that electricity consumption is not ...

International Nuclear Information System (INIS)

Tests on the scrubbing column have led to the following results: Use of a scrubbing column with Raschig rings is only meaningful for the sedimentation of particles exceeding diameters of 0.5 #mu#m; drops of diameter size 1.5 #mu#m are formed in the column; more efficient drop precipitators in the column air flow ease the load on subsequent suspended material filters thereby contributing to a longer life of these filters even at higher sodium ion concentrations in the washing water; with distillate of an 8% rather than 0.8% salt solution a decontamination factor greater than 10 can be calculated since larger particles precipitate more readily. This only applies, however, under the condition that the washing water is renewed regularly, if necessary daily where higher aerosol concentrations are present. If not, the decontamination factor will be reduced through the salt-containing secondary aerosols from the washing water. ...

International Nuclear Information System (INIS)

Solid state nuclear track detectors (SSNTD) are widely used for radon measurements and CR-39 is one of the most popular SSNTD. In this work it was determined the calibration factor for radon concentration measurements through the passive method with CR-39 detectors. The detectors were put in a proper device (an adapted Lucas cell) and exposed to the standard radon concentration through the Pylon Model RN-150 flow through radon gas source. After exposure, the detectors were etched for 5.5 hours in a KOH solution at 80 deg C in a bath at a constant temperature. The track density was read in an Axiolab-Zeiss optical microscope, with nominal magnification of X10 connected to a video camera and to a personal computer. The calibration factor was obtained through the relation between standard radon concentration, track density and exposure time. (author)

Energy Technology Data Exchange (ETDEWEB)

E-35 reported the specific air flow analysis program using a CFSV model (including a human body model) to develop a high-accuracy evaluation simulator for heterogeneous thermal environment based on human thermal physiological conditions. E-36 reported development of the radiation heat transfer analysis module by using a numerical integral method to calculate shape factors. Radiation heat transfer characteristics every body part were clarified quantitatively by this module. E-37 reported the results on continuous measurement of physiological conditions and thermal environment factors every monitor under controlled indoor thermal environment, to collect measurement data necessary for improving the accuracy of a prediction program for human body temperatures. E-38 reported the study result on physiological reaction and subjective evaluation through an examinee experiment in a blood controlled region, to collect basic data for ...

Energy Technology Data Exchange (ETDEWEB)

The atrial myocardium has been barely visible with thallium-201 myocardial scintigraphy. This is probably related to the difference in size, distance from anterior chest wall, and small coronary blood flow of the atrium, compared with the ventricle. We have encountered eight cases of visualization of the right atrial appendix (RAA). The RAA was identified from multiple projections in all cases and sometimes confirmed by radionuclide angiocardiography. Evidence derived from ECG, chest radiographs, and cardiac catheterization, indicated that the most important factor in the visualization might be the displacement of the RAA to a more anterior position.

Energy Technology Data Exchange (ETDEWEB)

A weak shift of the isotope concentration ratio Li{sup 6}/Li{sup 7} was measured in the coexisting phases of the miscibility gap of lithium-ammonia solutions. Li{sup 6} is slightly enriched in the concentrated metallic phase (enrichment factor {alpha} = 1.009 {+-} 0.002). This effect can be enhanced in a counter-current column to yield any desired enrichment of the two isotopes. The counter current system and its operation were tested succesfully with a sodium-potassium-ammonia solution.

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: ...

Energy Technology Data Exchange (ETDEWEB)

In this study based on the mass transfer theory, experiments for the evaporation rates depending on various conditions were carried out through the operation of the existing Natural Evaporation Facility in KAERI. Evaporation media were made of the cotton and polyester. Air circulation in the facility was forced by exhausting fans. The evaporation rate and the decontamination factor were calculated by the result of experiment. The evaporation rate increased as the flow rate of air supply, the feed rate of liquid waste, and the temperature of supplied air increased. As for the humility of supplied air, the evaporation rate was getting higher as the humidity was getting lower. As the result of this study, operation conditions of the Natural Evaporation Facility are optimized as follows; The air temperature above 8C .deg., the air humidity below 70%, the air flow rate 1.14-1.47 m/sec, and the liquid waste feed rate ...

International Nuclear Information System (INIS)

Nowadays, computational fluid dynamics is being applied in many fronts to improve the understanding of the flow and heat transfer behaviour in engineering applications. Unfortunately, there are not so many computational investigations regarding the ventilation and temperature distribution in discs-brakes. In this respect, this study presents a (CFD) analysis is carried out to investigate temperature distributions and flow patterns through disc brakes. The final goal is the development of shapes that optimize heat dissipation rates dictating the stopping capability of disc brakes. High performance discs brakes have a variety of cooling channels and the optimization of these passages is a challenging task for the manufacturing industry. High values of heat transfer coefficients of disc-brake configurations, are the most critical quantities during the design phase of new braking systems. In this context, a parametric study of the ...

International Nuclear Information System (INIS)

Gyrokinetic particle simulation of edge pedestal formation and plasma rotation dynamics will be presented, and compared with experimental observations. Realistic tokamak edge geometry is used which include separatrix/X-point and material wall from EFIT g-eqdsk data. In order to handle adequately the spatially inhomogeneous electric potential in the scrape-off region, the full-f electron technique is used, in addition to the full-f ions. Monte Carlo neutral particles with wall recycling coefficient will be included self-consistently with the plasma kinetics. Ion-ion Coulomb collisions will be particle, momentum and energy conserving. Energy source for the pedestal and scrape-off plasmas is the heat flow from the core plasma, and the particle source is the ionization of the neutral atoms which are either wall recycled and/or gas puffed. The simulation will be self-consistent with the first principles nonlinear neoclassical and (electrostatic so far) turbulence ...

International Nuclear Information System (INIS)

Ferrofluids have promising potential for heat transfer applications, since advective transport in a ferrofluid can be readily controlled by using an external magnetic field. However, unlike conventional free or forced convection, ferrohydrodynamic convection is not yet well characterized. A full understanding of the relationship between an imposed magnetic field, the resulting ferrofluid flow, and the temperature distribution is a prerequisite for the proper design and implementation of applications involving thermomagnetic convection. The literature variously assumes constant magnetic fields, does not completely represent the variation in the imposed field, or its descriptions are inaccurate, since the fields do not comply with the Maxwell's equations of electromagnetism. We address this by simulating two-dimensional forced convection heat transfer in a channel with a ferrofluid that is under the influence of a two-dimensional magnetic field ...

International Nuclear Information System (INIS)

The medical applications of radiation comprise three main fields namely: Diagnostic Radiology, Radiotherapy and Nuclear Medicine. With the new weighting factors of ICRP (IC91a) the effective dose due to medical applications can be established. I is common to separate the effective dose into the genetic part and the somatic part, SED. In dealing with gonad doses it is important to account for the age of the person at the time of exposure as this will influence the number of children still to be expected from that person. The resulting dose will then be called the genetically significant dose, GSD. In a similar fashion this age factor will be important in considering the chance of tumor induction. The age of patients differs considerably from the average age of the general population. This age difference has to be accounted for if a comparison is to be made with other sources of radiation. This justifies establishing a ...

International Nuclear Information System (INIS)

The main problems arising in decommissioning nuclear-powered submarines (NPS) relate to choosing a concept of handling reactor compartments followed by handling technology development. Reactor compartments (RC) are characterized with extremely space-saving or integral layout of large-size power equipment and systems, restricted access for dismantling, high radiation dose rates in a number of bays of RC. The above RC features pose a problem to find optimum option of RC utilization which on the one hand would be the most cost efficient, and the safest as possible on the other, i.e. dose commitments of personnel involved should be minimum, and effect on population and environment should be negligible. The main radiation factors specifying safety in RC handling at any decommissioning stage are as follows: (1) total radioactivity integrated in reactor facility (RF); (2) distribution of this radioactivity through RF equipment and structures; (3) forms the radioactivity ...

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 and implementation ...

International Nuclear Information System (INIS)

The term 'Post-CHF' was generally used in the two-phase flow regime in tube flow occurring downstream of the CHF. It has various other names such as dispersed flow, liquid-deficient flow, mist flow and film boiling because the two-phase regime is characterized by a continuous vapor phase with discrete liquid drops and a non-wetted heated surface. The regime has been adopted in a lot of applications including nuclear power plants, fossil power plants, steam generators, refrigeration systems and spray cooling, In particular, this regime has a considerable importance in the areas of light water reactor(LWR) accident analysis (off-normal operating conditions) and design in heat exchangers operating in the once-through mode where subcooled liquid enters the exchanger and superheated vapor exits. Recently, innovative PWRs adopt very high power density increases and so require increased ...

International Nuclear Information System (INIS)

Three simulated low-level reactor wastes were dried using a spray dryer-baghouse system. The three aqueous feedstocks were sodium sulfate waste characteristic of a BWR, boric acid waste characteristic of a PWR, and a waste mixture of ion exchange resins and filter aid. These slurries were spiked with nonradioactive iron, cobalt, and manganese (representing corrosion products) and nonradioactive cesium and iodine (representing fission products). The throughput for the 2.1-m-diameter spray dryer and baghouse system was 160-180 kg/h, which is comparable to the requirements for a full-scale commercial installation. A free-flowing, dry product was produced in all of the tests. The volume reduction factor ranged from 2.5 to 5.8; the baghouse decontamination factor was typically in the range of 10"3 to 10"4. Using an overall system decontamination factor of 10"6, the activity of the off-gas was calculated to ...

Energy Technology Data Exchange (ETDEWEB)

The present work reports an experimental study on the behavior of a jet flame surrounded by a shroud of combustion air. Measurements focussed on the flame length and the emissions of NO{sub x}, total unburned hydrocarbons, CO{sub 2}, and O{sub 2}. Four different fuel flow rates (40.0, 78.33, 138.33, and 166.6 cm/s), air flow rates up to 2500 cm{sup 3}/s and four different air injector diameters (0.079 cm, 0. 158 cm, 0.237 cm, and 0.316 cm) were used. The shroud of combustion air causes the flame length to decrease by a factor proportional to 1/[p{sub a}/p{sub f} + C{sub 2}({mu}{sub a}Re,a/{mu}{sub f}Re,f){sup 2}]{sup {1/2}}. A substantial shortening of the flame length occurred by increasing the air injection velocity keeping fuel rate fixed or conversely by lowering the fuel flow rate keeping air flow rate constant. NO{sub x} emissions ranging from 5 ppm to 64 ppm were observed and ...

Energy Technology Data Exchange (ETDEWEB)

The influence of location of airborne particle source, ventilation rate, air inlet size, supply air velocity, air outlet location, and heat source on the distributions of airborne particle concentration and draught risk in an operating room is investigated. The investigation is carried out by using a flow program with the k-[epsilon] model of turbulence. Based on a standard case, five cases, each with one changed parameter, are computed, and the detailed field distributions of air velocity, temperature, airborne particle concentration, and draught risk are presented. The parametric study concludes that, for a better air quality and thermal comfort, it is desirable to use a higher inflow rate, a larger inlet area, and a uniform velocity profile of supply air. Outlet location and heat source have little influence on the distributions of the particle concentration in the room. It has also been found that the distributions of ...

Energy Technology Data Exchange (ETDEWEB)

We intend to solve equations governing turbulent plane-vertical isotherm and non isotherm jets by taking into account inflow conditions at the exit of the nozzle. The analysis is focused on the influence of these conditions on this type of flow. Two cases are considered (uniform and parabolic velocity and temperature profiles). A finite difference scheme is developed to solve the governing equations. This numeric model allows us to show that the region of fully developed regime begins much nearer the nozzle for the turbulent case than for the laminar flow case. Indeed, the turbulence increases the mixing between the incoming gas from the nozzle and the ambient fluid, and consequently the size of the potential core zone decreases. The results are compared to other works introducing mathematical variables based on the energy conservation for the case of the mixed convection and the momentum conservation for the forced ...

International Nuclear Information System (INIS)

This study presents a dynamic analysis of a rotor supported by two turbulent flow model journal bearings and lubricated with couple stress fluid under nonlinear suspension. The dynamics of the rotor center and bearing center is studied. The dynamic equations are solved using the Runge-Kutta method. The analysis methods employed in this study is inclusive of the dynamic trajectories of the rotor center and bearing center, power spectra, Poincare maps and bifurcation diagrams. The maximum Lyapunov exponent analysis is also used to identify the onset of chaotic motion. The results show that the values of dimensionless parameters l* strongly influence dynamic motions of bearing and rotor centre. It is found that couple stress fluid improve the stability of the system when l* > 0.4 even if the flow of this system is turbulent. We also demonstrated that the dimensionless rotational speed ratios s and the dimensionless ...

Science.gov (United States)

A "hemispheres-in-cell" geometry is provided for prediction of colloid retention during transport in porous media. This new geometry preserves the utilities provided in the Happel sphere-in-cell geometry; namely, the ability to predict deposition for a range of porosities, and representation of the influence of neighboring collectors on the fluid flow field. The new geometry, which includes grain to grain contact, is justified by the eventual goal of predicting colloid deposition in the presence of energy barriers, which has been shown in previous literature to involve deposition within grain to grain contacts for colloid:collector ratios greater than approximately 0.005. In order to serve as a platform for predicting deposition in the presence of energy barriers, the model must be shown capable of quantitatively predicting deposition in the absence of energy barriers, which is a requirement that was not met by previous grain to grain contact ...

International Nuclear Information System (INIS)

The aim of this report was to assess the usefulness of cerebral blood flow (CBF) scanning utilising the SPECT technique in forensic medicine cases in the area of civil law cases. CBF SPECT scanning was performed in four patients utilising "9"9"mTc-ECD and a triple-head gammacamera. In the analysis both the asymmetry index and cerebellar normalisation were applied. Reference values were obtained by studying 30 healthy volunteers. In those cases CBF SPECT scanning played an important role in forensic argument. It influenced the sentence and the amount of financial compensation. CBF SPECT scanning may provide valuable information in forensic medicine argument in civil law cases, but only when taken together with psychometric tests and other neuroimaging methods (CT, MRI). The value of CBF SPECT scanning alone may be limited in judicial proceedings. (author)

Energy Technology Data Exchange (ETDEWEB)

Stainless steels can get pitting corrosion in halide containing solution, which make them a big risk in industrial production. Many investigations were made in the past in order to understand processes involved in pitting corrosion, pit initiation and pit growth. Results about the influence of alloying elements, their contents, the state of the structure, the condition of the surface, the content of chloride, the temperature, the pH-value, the velocity of flow and of the oxidizer on the chloride induced pitting corrosion of passive stainless steels are presented. Electrochemical measurements and the application of surface analytical methods (SEM, SAM, XPS) with high lateral resolution are carried out. A part of the samples received a diffusion annealing in order to obtain reproducible results. Pitting Resistance Equivalents (PRE) - Pitting Index - with different multipliers are given and discussed critical. An electrochemical method for ...

CERN Document Server

The Eady problem of baroclinic instability as applicable to quasi-geostrophic oceanic flows with zero internal PV gradients is revisited by introducing a mild slope and Ekman pumping on the lower boundary. The solution behaviour is determined by the isopycnal slope relative to either the bottom slope or the ratio of Ekman depth to horizontal wavenumber. Attention is paid to the physical interpretation of the growing, decaying and stable disturbances, with emphasis on the intimate connection between the quasigeostrophic edge waves and Eady waves, and the role of the isopycnal slope for the stability properties as opposed to the bottom density gradient. The disturbance structure is found to be strongly influenced by the boundary conditions. For a sloping bottom boundary, the growth rate is enhanced for the most unstable waves if the isopycnals tilt in the same direction as the bottom, but in general non-standard boundary conditions tend to retard ...

Energy Technology Data Exchange (ETDEWEB)

Charge transport in disordered organic semiconductors is generally described as thermally activated hopping in a gaussian distribution of localized states. The presence of charge traps is critical to the performance of organic electronic devices, since trapped charge carriers do no longer contribute to the current flow. The trap distribution in the polymer poly(3-hexylthiophene) (P3HT) is investigated by applying the fractional thermally stimulated current technique. Thereby, a low temperatur double-peak distribution has been revealed. One of the peaks is believed to belong to the tail of the intrinsic density of states, whereas the other trap is strongly affected by exposure to oxygen. We discuss the influence of oxygen exposure time on the trap distribution.

British Library Electronic Table of Contents (United Kingdom)

After presenting a geochemical model for the interaction between calcite and varying environmental conditions, the paper discusses the experimental results of long duration electrokinetic tests, run on a natural clayey soil in unbuffered conditions. Local measurements of electrical potential, temperature and water flow were performed during the tests, while pH and fluid conductivity were measured locally once the tests had been dismantled. Sharp change of pH and reduction of the soil electrical conductivity, that in pure clays usually occur in the proximity of the cathode, were observed in the region close to the anode. As well, the soil in the anode area systematically tended to develop fractures, that mostly persisted until the end of the experiments. The features observed, that are not ...

British Library Electronic Table of Contents (United Kingdom)

Optimization of nonviral gene delivery typically focuses on the design of particulate carriers that are endowed with desirable membrane targeting, internalization, and endosomal escape properties. Topographical control of cell transfectability, however, remains a largely unexplored parameter. Emerging literature has highlighted the influence of cell-topography interactions on modulation of many cell phenotypes, including protein expression and cytoskeletal behaviors implicated in endocytosis. Using high-throughput screening of primary human dermal fibroblasts cultured on a combinatorial library of microscale topographies, we have demonstrated an improvement in nonviral transfection efficiency for cells cultured on dense micropit patterns compared to smooth substrates, as verified with flow...

International Nuclear Information System (INIS)

Heat transfer augmentation based on the process intensification concept in heat exchangers and thermal reactors has received much attention in recent years, mainly due to energy efficiency and environmental considerations. The concept consists of the development of novel apparatuses and techniques that, compared to those commonly used today, are expected to bring dramatic improvements in manufacturing and processing, substantially decreasing equipment size, energy consumption, and ultimately resulting in cheaper, sustainable technologies. The objective of this paper was to investigate the heat transfer characteristics of tubular thermal reactor using static mixing technology. Glycerin and water were used as the test fluids and water was used as the heating source. The results for heat transfer rate were strongly influenced by tube geometry and flow conditions.

British Library Electronic Table of Contents (United Kingdom)

Due to the advantages of the flexibility and economics in exploration and production of offshore liquefied natural gas (LNG), the floating production storage and offloading unit for liquefied natural gas (LNG-FPSO) has attracted wide attentions in recent years. The offloading system for LNG transportation from LNG-FPSO to LNG carrier is one of the most important parts in LNG-FPSO. The influences of the main parameters such as the mass flow rate and the height difference of the pipeline. on the performance of LNG offloading in offshore associated gas fields were investigated. A model based on a typical offshore LNG offloading system was first established and simulations were conducted. The governing equations were then used to evaluate the effects of parameters together with the simulation ...

CERN Document Server

Although hydrogen is the simplest of atoms, it does not form the simplest of solids or liquids. Quantum effects in these phases are considerable (a consequence of the light proton mass) and they have a demonstrable and often puzzling influence on many physical properties, including spatial order. To date, the structure of dense hydrogen remains experimentally elusive. Recent studies of the melting curve of hydrogen indicate that at high (but experimentally accessible) pressures, compressed hydrogen will adopt a liquid state, even at low temperatures. In reaching this phase, hydrogen is also projected to pass through an insulator-to-metal transition. This raises the possibility of new state of matter: a near ground-state liquid metal, and its ordered states in the quantum domain. Ordered quantum fluids are traditionally categorized as superconductors or superfluids; these respective systems feature dissipationless electrical currents or mass ...

Energy Technology Data Exchange (ETDEWEB)

Main results are summarised for a project carried out with the aim of increasing the knowledge of relations between handling characeristics and properties such as moisture content, particle size and shape etc. Handling characteristics that were studied: angle of repose, friction between fuel and different surfaces, the fuel`s tendency to bridge across openings, and its freezing characteristics. Some forty solid biomass fuels were studied, mainly wood fuels, with particle sized from 1 to 200 mm. New methods were developed for measurement of bridging across openings and freezing characeristics. The angle of repose varied between 25 and 55 deg. The particle shape had a significant influence, a high ratio of length/thickness gave a high angle of repose. When the fuel moisture content was increased the angle of repose first increased, then decreased, and finally increased again. The particle size had no influence. The friction depended more on the ...

International Nuclear Information System (INIS)

Important steady-state thermohydraulic parameters of the TRIGA research reactor operating under natural convection mode of coolant flow were investigated using NCTRIGA computer code. Neutronic parameters used in preparing the input of NCTRIGA were taken from the analysis performed by 3-D Monte Carlo code MCNP4C. Benchmarking of the NCTRIGA calculated results were performed against the experimental data measured by the thermocouples in the instrumented fuel element (IFE) during the steady state operation of the reactor under natural convection mode of coolant flow. Various thermohydraulic parameters like the coolant velocity, flow rate and mass flow rate were generated for the hot channel as well as for the two channels comprising instrumented fuels. Calculated peak fuel temperatures at different power levels were compared with the measured values and also with the calculations performed by PARET code. ...

Science.gov (United States)

... 65th AGARD Fluid Dynamics Symposium, Madrid, Spain, October ... of research programs on flow control ... separation, and delta wing flows formed the ...

International Nuclear Information System (INIS)

LEDF (Large Equipment Dismantling Facility) will be constructed for the purpose of decontaminating the high level #alpha# solid waste generated in oarai engineering center of JNC. And, main processing process of LEDF is incineration and melting system. LEDF will be intended to reduce the secondary waste that occurs along with the operation of the off gas processing equipment of incineration and melting system. It assumed that we are able to eliminate the adsorption tower using silica gel, if the decontamination factor to volatile ruthenium is able to expect in the packed scrubber that is established to remove harmful gas. Thereupon, we carried out this tests that eliminates the adsorption tower and reduces the secondary waste. The decontamination factor (DF) to the volatile ruthenium by the water scrubber is confirmed in the established institution which is in Tokai Works. However, decontamination factor differs and depends ...

Science.gov (United States)

impflrtant to the understanding of complex vortical flows. ... tions like the slender wing, flow separations are controlled in the s,. ...... 10, AGARD LS-121, Dec. ...

CERN Document Server

Industrial-process control valves Part2 : Flow capacity Section Four : Inherent flow characteristics and rangeability

Energy Technology Data Exchange (ETDEWEB)

The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of actuated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the water chemistry to decrease these risks are discussed. A special focus is put on zinc water chemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet ...

Science.gov (United States)

... Title : THE INFLUENCE OF GRAIN BOUNDARY CARBIDE DENSITY ON THE BRITTLE FRACTURE OF FERRITE PEARLITE STEELS. ...

Energy Technology Data Exchange (ETDEWEB)

In this study the greenhouse impact of the total Finnish forest sector was considered, which means that the estimated emissions and sink effects from exported forest products were also included. The forest biomass is and seems to be in the next decades the most important factor in the carbon balance of the total forest sector. The development alternatives of forest industries and waste management practices has still a remarkable influence on the greenhouse impact of the Finnish forest sector. The waste management practices in the future has an important influence on the emissions but the exact net greenhouse impact of the landfills is still uncertain. However, the methane emissions from existing landfills can be reduced essentially by gas recovery. Increased incineration and energy recovery of wood waste (and replacing fossil fuel use by it) is also a future alternative for reducing the greenhouse effects in the forest ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

This report aims to address the potential for solid polymer fuel cell (SPFC) systems to be successfully exploited in the combined heat and power (CHP) market. A number of market studies have been undertaken to look at the size and future potential for this CHP market as well as such issues as market forces and geographical locations. This study focuses on a different aspect, that of the technical and commercial requirement together with the development needs. In order to understand how an SPFC system will have to perform, it is first necessary to examine the criteria used to judge the commercial merits of a particular CHP scheme. Issues that must be addressed include: the investment criteria - time to pay back the investment or rate of return on the investment; the influence of external factors such as electricity cost tariffs, fuel price and regulatory requirements; the cost and performance of existing technology; and the ...

International Nuclear Information System (INIS)

The trifluoroacetate metal-organic decomposition route to YBa_2Cu_3O_7 film growth was investigated in order to bring new insights in the growth mechanism and its dependence on processing conditions and critical current density. Precursor films were processed on LaAlO_3 substrates at different total pressure, oxygen partial pressure, water vapor partial pressure, and volume gas flow rate keeping the growth temperature at 740 "0C. The influence of these various experimental parameters on the film growth rate, which was evaluated by in situ electrical resistance measurements, was studied thoroughly. It was found that the growth rate is nearly independent of the oxygen pressure and proportional to the square root of the water pressure. Additionally, the growth rate increases with a decrease of the total pressure or an increase of the gas flow rate. An empirical multi-exponential model simulates the experimental data, however, ...

CERN Document Server

The adjoint of an ocean general circulation model is used as a tool for investigating the causes of changes in ENSO SST indices. We identify adjoint Kelvin and Rossby waves in the sensitivities to sea level and wind stress at earlier times, which can be traced back for more than a year through western and weak eastern boundary reflections. Depending on the thermocline depth the first and second baroclinic modes are excited. The sensitivities to the heat flux and SST are local and decay in about a month. The sensitivities to the fluxes are converted into the influence of SST using the adjoint of a statistical atmosphere model. Focusing on SST perturbations in the index region itself, we recover, up to a scale factor, the delayed oscillator concept.

British Library Electronic Table of Contents (United Kingdom)

Abstract Normal human aging is accompanied by progressive brain tissue loss and cognitive decline; however, several factors are thought to influence brain aging. We applied tensor-based morphometry to high-resolution brain MRI scans to determine whether educational level or physical activity was associated with brain tissue volumes in the elderly, particularly in regions susceptible to age-related atrophy. We mapped the 3D profile of brain volume differences in 226 healthy elderly subjects (130F/96M; 77.9 3.6 SD years) from the Cardiovascular Health Study-Cognition Study. Statistical maps revealed the 3D profile of brain regions whose volumes were associated with educational level and physical activity (based on leisure-time energy expenditure). After controlling for age, sex, and physical...

British Library Electronic Table of Contents (United Kingdom)

Although past research has reported the benefits of intuition in new product decision-making (i.e., higher quality product; enhanced customer satisfaction), intuition has largely been studied as an individual phenomenon and little work has examined the role of intuition on new product development (NPD) project teams. Furthermore, in a turbulent environment, NPD project teams may rely more on intuitive judgments, and other factors such as experience and stress may also influence the relationship between team intuition and team decision making. Drawing from the organizational design literature on creativity in decision making, this study builds a conceptual model of NPD team intuition and its effect on the team's ability to generate creative new products. We then derive hypotheses regarding ...

British Library Electronic Table of Contents (United Kingdom)

Abstract The available surface equation of state for pure pulmonary surfactant monolayers is generalised to binary mixture monolayers by introducing a group of parameters, i(i-=-1-4) in the form of $x_{r}^{\\beta _{i} } $ to express the influence of the components in new mixing rules and a new factor, I $\\left[ { = \\left( {\\prod\\limits_{i = 1}^{4} {\\beta _{i} } } \\right)^{{\\raise0.5ex\\hbox{$\\scriptstyle 1$}\\kern-0.1em/\\kern-0.15em\\lower0.25ex\\hbox{$\\scriptstyle {4}$}}} } \\right]$, is defined to represent the interaction intensity between two different components. The ---A isotherms getting by the surface equations of state agree with the experimental data for protein-lipid binary monolayers, and the average deviation is about 11.41%. The result shows the order of the interaction intensity b...

International Nuclear Information System (INIS)

With the preeminence of A-15 superconducting multifilamentary wires in magnet technology, it has become important to understand the thermodynamic factors influencing the formation of these compounds under solid-state reaction conditions. The six systems Nb--Sn, Nb--Ga, Nb--Ge, Nb--Al, V--Si, and V--Ga were prepared as single filament bronze wires and heat treated in an attempt to precipitate the appropriate A-15 compound. The compounds observed to form were categorized using a formation temperature ratio (stability index) based on the melting temperatures of the constituents which make up the single filament composites. This study has led to several predictions regarding the formation of A-15 compounds using a solid-state bronze diffusion technique. The results of experimentation based on these predictions are presented.

International Nuclear Information System (INIS)

Bisaminoethanethiol (BAT) ligands with various gem-dimethyl and amide groups were prepared, and the corresponding neutral Tc-99m complexes were prepared and evaluated for their relative stabilities by ligand-exchange reactions. It was demonstrated that technetium complexes containing gem-dimethyl substituents have higher lipophilicities, whereas those with an amide group possess greater stability, which enhances ligand-exchange reaction. The most interesting observation was that the brain uptake in rats is not determined only by lipophilicity. Apparently, Tc-99m complexes with an amide functional group display lower brain uptakes in rats compared to those without an amide group. The brain uptake was strongly influenced by substituents on the BAT ligand. These factors are critically important and should be taken into consideration when designing Tc-99m-labeled agents for CNS receptor imaging.