A back-up system is provided for a pumping plant or a pressure reservoir system used to maintain insulating oil under pressure in high voltage submarine power cables which includes a gas driven membrane pump to insure a small outflow of oil at a rupture point in the power cable to prevent water from penetrating the cable. The proper operation of the membrane pump is insured by introducing degasified oil at the drive side of the pump during the stand-by and test modes of operation of the back-up system. 11 drawings.
Purpose - Based upon the E-VALUE model developed, this paper aims to investigate the impact of e-commerce usage on business performance in the tourism sector. Design/methodology/approach - A cross-sectional survey is carried out on 165 Malaysian firms involved in the tourism sector (hotels, resorts, and hospitals engaged in health tourism) through the use of a structured questionnaire. Findings - The structural equation modeling results indicate that technology competency, firm size, firm scope, web-technology investment, pressure intensity, and back-end usage have significant influence on e-commerce usage. Among these variables, back-end integration is found to function as a mediator. E-commerce experience (in years) is found to moderate the relationship between e-commerce usage and busin...
Some bacteria move inside cells by recruiting the actin filaments of the host cells. The filaments are polymerized at the back surface of the bacteria, and they move away, forming a "comet" tail behind the bacterium, which consists of gel network. We develop a one-dimensional mathematical model of the gel based on partial differential equations which involve the number of filaments, the density and velocity of the gel, and the pressure. The two end-points of the gel form two free boundaries. The resulting free boundary problem is rather non-standard. We prove local existence and uniqueness.
This talk reviews the history of the Canadian nuclear-electric program highlighting Canada's first nuclear power station, the Nuclear Power Demonstration or NPD. NPD was commissioned and delivered electricity to Canadian consumers for the first time on june 4, 1962. The Canadian nuclear-electric program is based on the CANDU-PHW (Canadian Deuterium Uranium - Pressurized Heavy Water) concept which was conceived between 1955 and 1958 at the Chalk River Nuclear Laboratory (CRNL) of AECL, located a few miles from Deep River. This talk covers the history of the Canadian nuclear-electric activities dating back to 1939.
In the design of natural gas compressor stations, a check valve is a critical element which is commonly placed on the discharge side of the compressor to prevent reverse flow that can cause serious damage to the compressor itself and other components such as seals and bearings. One of the selection criteria of the check valve for this particular application is the valve flow characteristics in steady flow, and its dynamic characteristics in unsteady flow operation. With regards to steady flow valve characteristics, current models for the determination of the check valve open angle vs. mean flow velocity are based on semi-empirical data obtained from water tests, which were found to deviate from measurements in compressible flows. This paper presents results of steady compressible flow testing of an NPS 4 swing type check valve in air. Mean flow velocities vs. disc angles were measured together with several local pressure measurements at the ...
In the design of natural gas compressor stations, a check valve is a critical element which is commonly placed on the discharge side of the compressor to prevent reverse flow that can cause serious damage to the compressor itself and other components such as seals and bearings. One of the selection criteria of the check valve for this particular application is the valve flow characteristics in steady flow, and its dynamic characteristics in unsteady flow operation. With regards to steady flow valve characteristics, current models for the determination of the check valve open angle versus mean flow velocity are based on semi-empirical data obtained from water tests, which were found to deviate from measurements involving fluids of relatively higher compressibility. This paper presents results of steady flow testing of an NPS 4 swing-type check valve in air. Mean flow velocities versus disk angles were measured together with several local pressure measurements at the ...
Background: Measurements from pressure biofeedback units (PBUs) can be used to evaluate the activity of the transversus abdominis (TrA) muscle indirectly. These measurements can classify patients or monitor the progress of treatment programmes for people with low back pain. Objective: To systematically review studies on the measurement properties of PBUs for the assessment of TrA activity. Data sources: Eligible studies were identified through searches of PUBMED, CINAHL and BIREME (1990 to 2009). In addition, hand searches of journals and citation tracking were performed. Study selection: Full-text studies involving any type of clinimetric tests of PBU measurement for the assessment of TrA activity were selected. Data extraction: Two independent reviewers selected the studies, extracted th...
Aim: This study was performed: 1) to assess the relationship between blood flow velocity in the internal carotid artery (CBFICA) and pial artery pulsation (cc-TQ) and 2) to evaluate flow-induced changes in pial artery compliance. Methods: Experiments were performed on 10 crossbred male rabbits. Heart rate (HR), blood pressure (BP), left ventricle ejection fraction (LVEF), CBFICA, the systolic-diastolic blood volume fraction in the brain circulation (CBFSDF) and cc-TQ were recorded after glucagon and acetazolamide administration. cc-TQ was measured with near-infrared transillumination back scattering sounding (NIR-T/BSS), LVEF and CBFSDF with gated scintigraphy and BP and CBFICA with electromagnetic pressure and flow transducers, respectively. Doses of drugs were chosen to exert a haemodyna...
Wolsong 2,3 and 4 fuel channel analysis during a large break loss of coolant accident with loss of ECCS injection (LOCA/LOECC) is performed to obtain the heat load to moderator. Because the single channel analysis requires the establishment of the safety codes and their input decks, the present study follows the same safety analysis methodology found in FSAR of Wolsong 2,3 and 4. From this work we obtain the safety tools such as CATHENA MOD3.5b/Rev.1 and CHAN-II/A MOD2 codes, and their code modeling in a form of code input deck. The analysis consists of two parts: front-end (blowdown period) and back-end. For the front-end analysis the fuel and pressure tube (PT) temperatures, and PT circumferential strains at the end of front-end as well as fuel channel depressurization are calculated using CATHENA code and used as initial and boundary conditions for back-end analysis. The back-end period under the ...
A natural gas and diesel dual-fuel turbocharged compression ignition (CI) engine is developed to reduce emissions of a heavy-duty diesel engine. The compressed natural gas (CNG) pressure regulator is specially designed to feed back the boost pressure to simplify the fuel metering system. The natural gas bypass improves the engine response to acceleration. The modes of diesel injection are set according to the engine operating conditions. The application of honeycomb mixers changes the flowrate shape of natural gas and reduces hydrocarbon (HC) emission under low-load and lowspeed conditions. The cylinder pressures of a CI engine fuelled with diesel and dual fuel are analysed. The introduction of natural gas makes the ignition delay change with engine load. Under the same operating conditions, the emissions of smoke and NO{sub x} from the dual-fuel engine are both reduced. The HC and CO emissions for the ...
Throughout the last decades, plasma technology has been established in a series of surface treatment applications, e.g. for semiconductor processing or optical coatings. The majority of plasma assisted technologies is based on low pressure processes. In recent years, however, non-thermal atmospheric pressure discharges have attracted considerable interest because of their simplified technical devices for industrial applications as compared to low pressure processes which require vacuum equipment. Hence, batch processing can be avoided, thus facilitating the implementation of plasma process steps into production lines. Investment costs are cut down significantly. The use of atmospheric pressure plasmas for technical applications dates back to the ozone production with dielectric barrier discharges (DBD) by Siemens in 1857. Lately, the application of atmospheric ...
A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle is within 10 ?s with the backingpressure as high as 25 bar. With a nanosecond laser pulse focused on the gas jet about 1 mm below the nozzle, the actuation time is calculated to be about 15 ms by detecting the laser produced spark radiation, which reveals the existence of the gas jet and the relative gas density evolving with time. Consequently the gas density is estimated to be well above 1019 cm-3, compared with theoretical simulations from the nozzle parameters.
The use of an extraction of the heme pigments hemoglobin and myoglobin as a test for the heat exposure of back bacon was investigated by treating back bacon at varying temperatures of 50-70 degrees...Full Text Available
The cold-worked Zr-2.5%Nb alloy is used as material for the pressure tubes in CANDU nuclear reactors. During the service life in reactor, diffusion of hydrogen and/or deuterium in the pressure tubes wall occur. Below a certain temperature, a stable hydride of zirconium is formed, as a brittle phase which can lead to catastrophic failures. For this reason, it is very important to be able to investigate the hydrogen effect on the micro structural properties of zirconium alloys. In the present paper a non-destructive testing technique is used, known as ultrasonic spectral analysis. When an ultrasonic signal traverses a medium, the frequency components associated with the input signal are altered. By frequency analysing the reflected signals, it is possible to study and compare the material properties. The two major parameters measured in ultrasonic spectroscopy are the attenuation and the velocity of the waves. Attenuation is determined by the ...
The recent attempt to degassify a self contained liquid filled (SCLF) cable in Ontario Hydro is described. In September 1989, there was a high pressure alarm on one phase of a SCLF 115 kV cable circuit. The direct buried cable circuit is about 1,890 m long with two joints and was installed in 1968. Oil samples from the cable had 10 to 12% gas content with high levels of hydrogen, methane, and ethane, and very low levels of carbon monoxide, carbon dioxide, and acetylene. From these results it was concluded that the gas was generated by low energy electrical discharges and the paper insulation was not degraded. Various utilities and cable manufacturers were contacted to find if they had experienced similar problems. The cable duct oil was flushed and gasified and the successive oil samples were analyzed in order to locate the gassing site. The joints were examined and oil samples were taken through holes drilled in the cable sheath. From the test results the problem ...
We explore a possibility that the daily sea-level pressure (SLP) over South Korea responds to the high-speed solar wind event. This is of interest in two aspects: First, if there is a statistical association this can be another piece of evidence showing that various meteorological observables indeed respond to variations in the interplanetary environment. Second, this can be a very crucial observational constraint since most models proposed so far are expected to preferentially work in higher latitude regions than the low latitude region studied here. We have examined daily solar wind speed ${\\rm V}$, daily SLP difference ${\\rm \\Delta SLP}$, and daily ${\\rm \\log(BV^{2})}$ using the superposed epoch analysis in which the key date is set such that the daily solar wind speed exceeds 800 ${\\rm kms^{-1}}$. We find that the daily ${\\rm \\Delta SLP}$ averaged out of 12 events reaches its peak at day +1 and gradually decreases back to its normal ...
Once again Brazil faces the possibility of an electricity shortage in the near future. The low level of rain and the consequent reduction of hydroelectric reservoirs (hydroelectric energy represents almost 80% the total Brazilian electricity generation) led to the dispatch of thermal plants based on natural gas and/or fuel oil. However, the recent crisis regarding the Bolivian natural gas supply to Brazil increased the risk of a shortage of this energy source. Hence, the uncertainty of the electricity supply scenario is pushing the electricity prices up in the near future. A possible alternative to increase the electricity supply is the maximization of the electricity surplus in sugarcane mills. Back in 1970's and 1980's, cogeneration plants in sugarcane mills were primarily designed to consume all bagasse, and produce steam and electricity to the process. The plants used medium pressure steam boilers (21 bar and 300 deg C) ...
BackgroundLow back pain (LBP) is the most prevalent musculoskeletal condition and one the most common causes of disability in the developed nations. Anecdotally, there is a general...Full Text Available
A patent is claimed for a process by which a low-hydrogen gas containing at least 90 percent by volume of methane which is suited for natural gas substitution is produced by transformation of vaporizable hydrocarbons with the aid of steam in the presence of a catalyst containing nickel, at temperatures of 350 to 600/sup 0/C and at increased pressure. Hydrocarbons and steam are supplied to the reaction in mixed form with recycle product gas. Per kilogramme of hydrocarbons to be converted in the high btu gas reactor, less than 1 kilogramme of fresh steam is needed. High btu gas is fed back from the high btu gas reactor to the input end of the same via a gas cycle comprising a cooler, a carbon dioxide absorption device, and a saturator. Between the carbon dioxide absorption device and the saturator a product gas is branched off which may pass a methanation device.
Deposition of hard coatings may influence the mechanical properties of the bulk material and its corrosion resistance. In this work we study the hardness of the coated and the back side of 100Cr6 steel plates. Electrochemical corrosion tests were performed in O{sub 2}-saturated acetate buffer of pH 5.6 at 25degC. Chromium nitride and titanium nitride coatings prepared by different physical vapour deposition processes, such as arc, thermionic arc evaporation, magnetron sputtering and ion-beam-assisted deposition (IBAD) were compared. The results show that, for sufficient corrosion protection, chromium nitride layers have to be thicker than 500 nm. An increased nitrogen partial pressure in the evaporation chamber of the IBAD process improves the corrosion resistance significantly. The hardness of the substrates was reduced in the case of thermoionic arc evaporation only, indicating a deposition temperature of more than 250degC. For this process, ...
Objective:To assess the efficacy of facet joint infiltrations for pain relief in 44 selected patients with chronic nonradicular low back pain (LBP).Materials...Full Text Available
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Five methods of personality assessment are evaluated to provide guidance for the psychological treatment of patients with chronic back pain. Patient pain drawings, pentothal pain studies, stress score...Full Text Available
The objective of this project is to increase oil recovery from fractured reservoirs through improved fundamental understanding of the process of spontaneous imbibition by which oil is displaced from the rock matrix into the fractures. Spontaneous imbibition is fundamentally dependent on the reservoir surface free energy but this has never been investigated for rocks. In this project, the surface free energy of rocks will be determined by using liquids that can be solidified within the rock pore space at selected saturations. Thin sections of the rock then provide a two-dimensional view of the rock minerals and the occupant phases. Saturations and oil/rock, water/rock, and oil/water surface areas will be determined by advanced petrographic analysis and the surface free energy which drives spontaneous imbibition will be determined as a function of increase in wetting phase saturation. The inherent loss in surface free energy resulting from capillary instabilities at the microscopic (pore ...
... mounted new operations against the TTP stronghold in ... was the fourth tranche of Pakistan's IMF-backed ... and brought the total funds received by ...
sabot: A device fitted around or in back of a projectile in a gun barrel or launching tube to support or protect the projectile or to prevent the escape of ...
Back pain from osteoporosis is commonly related to compression fractures. The patient with vertebral compression fractures additionally suffers from an ongoing risk of recurrent fractures and postural abnormalities that can result in impaired respiratory function, leading to increased risk of morbidity. Weakened back muscles, especially the back extensor group, are felt to contribute significantly to this risk. The combination of pharmacologic and nonpharmacologic interventions, through physical activity, exercise, and modalities, are potential interventions that could be used to help reduce the pain of osteoporotic compression fractures as well as potentially reducing recurrent fracture rates.
... It is well camouflaged and each individual has unique back pattern markings. It eats mainly spiders and insects. The Eastern Lined Earless Dragon is a small dragon lizard measuring up to 21cm in length. It is well camouflaged and each individual has unique back ... It is well camouflaged and each individual has unique back pattern markings. It eats mainly spiders and insects. It lives in and around grass tussocks as well as small holes in the ground that are also used by invertebrates such as wolf spiders and crickets....
The effect of severe plastic deformation by cold high pressure torsion (HPT) on radio frequency (RF) plasma nitriding of pure iron, as well as St2K50 and X5CrNi1810 steels was investigated. Nitriding was carried out for 3 h in a nitrogen atmosphere at a pressure of 10"-"5 bar and temperatures of 350 and 400 deg. C. Nitrided specimens were analysed by scanning electron microscopy (SEM), X-ray diffraction and micro hardness measurements. It was found that HPT enhances the effect of nitriding leading almost to doubling of the thickness of the nitrided layer for pure iron and the high alloyed steel. The largest increase in hardness was observed when HPT was combined with RF plasma nitriding at 350 deg. C. In the case of pure iron, the X-ray diffraction spectra showed the formation of #epsilon# and #gamma#' nitrides in the compound layer, with a preferential formation of #gamma#' at the expense of the #alpha#-phase at the higher nitriding ...
A modified accumulator was devised to measure surface radon flux from porous media. It consists of a collector hood accumulator with a homogenizer pump and a pressure balancer. The latter was used to compensate for any pressure changes produced during sample withdrawl and hence eliminate additional radon transport from media. Errors resulting from radon back diffusion due to decreasing concentration gradient with time across the interface were eliminated by measuring radon concentrations in the accumulator for two different periods of time and calculating the true radon flux, J(o), from the solution of a time-dependent radon transport equation. Core samples from the observation site were withdrawn for laboratory determination of porosity, moisture content, bulk and grain densities, Ra-226 source concentration and the fraction of Rn-222 produced in the void volume. The data were used to calculate the radon diffusion ...
For visible-light-emitting laser diodes, InGaAsP double heterostructures have been grown on GaAs substrates using liquid-phase epitaxy. As the growth temperature is as high as about 780 /sup 0/C, a large amount of phosphorus evaporates from the solutions for the cladding layers during the growth process. The phosphorus vapor disturbs the solution composition for the active layer, so that very thin and uniform active layers cannot be obtained. By using In-P-Sn solution and supplying the phosphorus partial pressure around the graphite boat, the influence of phosphorus vapor ambient for InGaAsP (lambda/sub P//sub L/ = 805 nm) growth is confirmed. When the phosphorus partial pressure increases, the surface of epitaxial layer becomes rough and the substrate is partly etched back. From x-ray diffraction and photoluminescence spectral measurements, the composition of the grown layer is also found to be changed. As a result of ...
Detonators are used to convert electrical or other energy into an explosive output. This output can then be used to initiate further explosive charges. To aid in the development of explosive systems, it is important to characterize the output of detonators, in particularly the pressure produced. Recent advances over the last five years in high-speed digitizing oscilloscopes and high-bandwidth photodiodes, driven primarily by the telecommunications industry, have enabled the development of a new type of interferometer for measuring high velocities, such as those found in detonics experiments. The Photonic Doppler Velocimeter (PDV) can be visualized as a fiber-based Michelson interferometer. The light from a single-mode fiber laser at 1550 nm is passed through a circulator, which acts to separate bi-directional light. The beam is then reflected via free-space optics off the surface of interest, and then focused back into the same fiber. This ...
A modified accumulator was devised to measure surface radon flux from porous media. It consists of a collector hood accumulator with a homogenizer pump and a pressure balancer. The latter was used to compensate for any pressure changes produced during sample withdrawl and hence eliminate additional radon transport from media. Errors resulting from radon back diffusion due to decreasing concentration gradient with time across the interface were eliminated by measuring radon concentrations in the accumulator for two different periods of time and calculating the true radon flux, J(o), from the solution of a time-dependent radon transport equation. Core samples from the observation site were withdrawn for laboratory determination of pkrosity, moisture content, bulk and grain densities, Ra-226 source concentration and the fraction of Rn-222 produced in the void volume. The data were used to calculate the radon diffusion ...
Liquid Zone Control (LZC) System is a 'first-of-its-kind' reactivity control device, designed and implemented at TAPP-3 and 4. The system provides zonal and bulk power control. The system consists of fourteen Zone Control Compartments (ZCCs) containing demineralised light water as neutron absorber. Reactivity control is achieved by varying the level of water in the compartments bi-directionally. Six in-core zircaloy assemblies, housing the fourteen ZCCs and an elaborate process system constitute the LZC system. Measurement of water levels in the ZCCs is done using helium bubbler method. Reliability of ZCC water level measurement is of paramount importance. Commissioning and operating the new system trouble free was a challenge, considering the complex nature of the system. While commissioning the system, level measurement of one of the ZCCs (ZCC - 1) was found erratic and inconsistent. Methodologies were developed to identify the problem and investigations revealed leakage of helium ...
An insulated letter drop plate comprises a back plate having an opening for the mail having two hinges at its upper part to attach a cover to; a frame for retaining a first insulation around its perimeter and around the opening; and suitable insulation. This back plate is also provided with an upper curved extension to cover and conceal said hinges. A cover is provided with two complementary hinges to be articulated with the first hinges on the back plate, and with a frame around the perimeter for the retention of a second insulation. A wire joins the first and second hinges, and a coil spring on the wire keeps the cover normally closed.
Dynamic response of pipelines buried in a back-filled rectangular trench in a semi-infinite medium has been investigated. The pipelines are modeled as long cylindrical shells of small thickness. By using the boundary integral representation and finite element method, we have studied the three-dimensional response to account for either pane P or SV wave incident at an arbitrary angle to the pipe-axis. In this paper numerical results are presented for the normal displacements, displacements along pipe-axis, and the hoop stresses in the pipe wall. It is shown that the response depends critically on the back-filled material as well as on the directions of propagation of the incident waves.
A numerical simulation of two-dimensional laminar natural convection in a fully open tilted square cavity with an isothermally heated back wall is conducted. The remaining two walls of the cavity are adiabatic. Steady-state solutions are presented for Grashof numbers between 10{sup 2} and 10{sup 5} and for tilt angles ranging from {minus}60{degree} to 90{degree} (where 90{degree} represents a cavity with the opening facing down). The fluid properties are assumed to be constant except for the density variation with temperature that gives rise to the buoyancy forces, which is treated by the Boussinesq approximation. The fluid concerned is air with Prandtl number fixed at 0.71. The governing equations are expressed in a normalized primitive variables formulation. Numerical predictions of the velocity and temperature fields are obtained using the finite-volume-based power law (SIMPLER: Semi-Implicit Method for Pressure-Linked Equations Revised) ...
Several different aspects of the influence of the target backing on in-beam electron spectra following compound nuclear reactions induced by accelerated ions at tandem energies irradiating backed targets are discussed in detail. This discussion is illustrated by a few typical examples, such as "1"2C"5"+ and "3"1P"1"0"+ beams at 4 MeV/u bombarding Sn(+Be), Sn(+Au), Pb(+C) backed targets. Moreover, the relative influence of electron backscattering, electron Doppler shift and Doppler broadening as well as #delta#-electron emission on the low energy electron spectra (E_e#<=#100 keV) obtained under such conditions are investigated in the frame of the available experimental data. (orig.).
Aug 26, 2011 ... The main article on the back of the poster explains star evolution in very simple terms (including the fate of our own Sun), and how a planetary ...
material may survive intact and mix back into interstellar gas clouds, helping to fuel the next generation of stars. NASA's Jet Propulsion Laboratory, Pasadena, Calif.,...
... the more the populace backs the TTP or, at ... the FATA, which does not wholly belong to Pakistan. ... While Congress authorizes and funds SA and the ...
and audio technology. The exhibition will travel to muse- ums and science centers in several U.S. cities over the next 5 years. Back in the classroom, ...
... mounted new operations against the TTP stronghold in ... was the fourth tranche of Pakistan's IMF-backed ... and brought the total funds received by ...
The traditional wing control surfacestrailing edge ailerons and the outboard leading edge flapsare used to provide the aerodynamic force needed to twist ...
BackgroundAdequate pain assessment is critical for evaluating the efficacy of analgesic treatment in clinical practice and during the development of new therapies. Yet the currently...Full Text Available
The effect of severe plastic deformation by cold high pressure torsion (HPT) on radio frequency (RF) plasma nitriding of pure iron, as well as St2K50 and X5CrNi1810 steels was investigated. Nitriding was carried out for 3 h in a nitrogen atmosphere at a pressure of 10{sup -5} bar and temperatures of 350 and 400 deg. C. Nitrided specimens were analysed by scanning electron microscopy (SEM), X-ray diffraction and micro hardness measurements. It was found that HPT enhances the effect of nitriding leading almost to doubling of the thickness of the nitrided layer for pure iron and the high alloyed steel. The largest increase in hardness was observed when HPT was combined with RF plasma nitriding at 350 deg. C. In the case of pure iron, the X-ray diffraction spectra showed the formation of {epsilon} and {gamma}' nitrides in the compound layer, with a preferential formation of {gamma}' at the expense of the {alpha}-phase at the ...
Purpose: To improve the reliability of control rod drive mechanisms for use in BWR type reactors by preventing erroneous insertion of control rods caused by the increase in the coolant pressure. Constitution: A pressure-releaf valve mechanism is provided which opens its valve when a detected difference between the pressure of the coolants flowing through coolant pipeways and the reactor pressure exceeds a predetermined pressure difference. If the coolant pressure increases abnormally, coolants in the coolant pipeway are released to lower the pressure. (Aizawa, K.).
Full text of publication follows: The TUV NORD e.V. is an independent Technical Support Organisation (TSO) performing safety assessments in almost every field of technology. In nuclear safety the TUV can look back on more than 40 years of experience. In the last years in Germany PWR safety analyses were focussed on boron dilution events with the potential of reactivity transients. The possibility of coolant with a low boron concentration collected in localized areas of the reactor coolant system (RCS) can be caused by injection of coolant with less boron content from interfacing systems (external dilution) as well as separation of borated reactor coolant into highly concentrated and diluted fractions (inherent dilution). Inherent dilution can e.g. occur after reflux-condenser heat transfer after a small break loss of coolant accident (SBLOCA) with a limited operability of the emergency core cooling (ECC) systems. The TUV Nord e.V. was charged by German supervisory ...
A new controlled-clearance pressure balance is under development with the aim of improving the hydraulic high-pressure standard up to 1 GPa. This pressure balance consists of three parts: (i) a pressure generation device up to 1 GPa, (ii) a weight-loading unit which can load/unload weights automatically and independently, (iii) a controlled-clearance piston-cylinder which is designed to allow the jacket pressure to be applied independently. Some adjustments were made for loading heavy weights on/off the piston safely, keeping them in balance, then generating the pressure stably. Stability of the generated pressure was checked for several piston-cylinders, and it was found that pressure fluctuation was less than a few parts per million. The jacket pressure coefficient of a 500 MPa controlled-clearance ...
The aim of this review is to evaluate the role of inflammatory spine disease in patients with chronic back pain. The contribution of imaging modalities for the diagnostic evaluation of back pain is discussed. A systematic literature search based on the classification of seronegative spondyloarthropathies and rheumatoid arthritis was performed. The results of this search and the experiences in a large collective of rheumatological patients are analyzed. The prevalence of rheumatoid arthritis (1-2%) is comparable to that of spondyloarthropathies (1.9%). The etiology of these entities is not fully elucidated. Magnetic resonance imaging is increasingly used for early detection and surveillance of therapy with TNF-#alpha# antagonists. Bone marrow edema, which is only detectable with MRI, represents an early sign of inflammation. Therapy with TNF-#alpha# antagonists is based on clinical and laboratory criteria, and signs of inflammation in MRI. MRI ...
We describe a case of sacral perineural cyst presenting with complaints of low back pain with neurological claudication. The patient was treated by laminectomy and excision of the cyst. Tarlov cysts...Full Text Available
More than 30 years ago, human beings looked back from the Moon to see the magnificent spectacle of Earth-rise. The technology that put us into space has since been used to assess the damage...Full Text Available
The juxtacapsular BNST (jcBNST) is activated in response to basolateral amygdala (BLA) inputs through the stria terminalis and projects back to the anterior BLA and to the central nucleus of...Full Text Available
A procedure for long lasting general anaesthesia in gulls (Larus sp.) is described. It is based on an initial basal intramuscular dose of pentobarbital sodium, supplemented if necessary by intravenous injection to effect of the same agent. Additional intr...
It is still a vision at the time being, but wind power and electric cars may complement each other efficiently: Batteries are charged when the power demand of the grid has been saturated. In case of sudden demand peaks, the stored power is transmitted back into the grid. (orig.)
Posterior spinal ligament pathology is becoming increasingly recognized as a significant cause of low back pain. Despite the growing clinical importance of interspinous ligament degeneration in low...Full Text Available
The indications, contra-indications and technique of caudal epidural injections in the treatment of low back pain and sciatica are described. Of 201 patients treated by epidural injection, about 56%...Full Text Available
Late last year the Wolsung Candu in Korea suffered an incident which resulted in heavy water being released from the primary system into the containment. With the unit now back at full power, this article examines the causes of the incident and the action which is being taken to prevent it happening again.
... Hospital & University Hospital Basel) If I Had - Pre-diabetes - Dr. Venkat Narayan, MD, MSc, MBA, Rollins School ... School, Massachusetts General Hospital, Discusses the Treatment of Diabetes Back to Home Page If I Had - A ...
tact materials ate Ti-Pd-Ag and the back surface reflector is formed from evaporated .... Ti-Pd-Ag, Dielectric Wraparound. BSR. Evaporated Aluminum ...
Lumbar epidural anesthesia is useful in a variety of chronic benign pain syndromes, including lumbar radiculopathy, low back pain syndrome, spinal stenosis, and vertebral compression fractures. Given...Full Text Available
Objectives. To assess the feasibility of treating musculoskeletal pain in the lower back and/or lower extremities in persons with Parkinson's disease (PD) with cranial electrotherapy...Full Text Available
Low back pain is common during pregnancy. However, the prevalence of symtomatic lumbar disc herniation is rare, and cauda equina syndrome due to disc herniation during pregnancy is even rarer. We report...Full Text Available
BackgroundAcute low back pain is a very common symptom and reason for many medical consultations. In some unusual circumstances it could be linked to a rare aetiology.Case...Full Text Available
A closed loop control process assures that a system performs within control limits. In closed loop control, the system's output feeds back directly to change the system's inputs. We describe an approach...Full Text Available
Reciprocal mass crosses and back-crosses were performed between two homogeneous strains of the housefly (Musca domestica L.), representing the extremes in susceptibility and resistance...Full Text Available
This paper reviews some of the mining equipment exhibited at the Chicago Minexpo exhibition. The exhibits include: large mining trucks; tractor with impact ripper; haulers; shuttle roof bolter; and monitoring systems for vehicles or mining machines. 2 figs.
In the last 40 years, significant advances have been made in the understanding of the neurophysiologic processes involved in the experience of trauma and pain. This knowledge, together with the rapid growth and understanding in the behavioral health sciences, has expanded to include a much better appreciation of how these fields are converging and contribute to a process called neuroplasticity. These basic mechanisms common to all patients have important implications for clinical outcome and for improving clinical practice. This article is written for clinicians who manage patients with sacroiliac joint dysfunction, a specific type of nonspecific low back pain.
To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that (1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; (2) approximately equal detection rates were obtained for the three X-ray ...
To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that 1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; 2) approximately equal detection rates were obtained for the three X-ray ...
Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LIQ) or ambient-temperature compressed hydrogen (CH2). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.
When withdrawing a fluid sample (for additional chromatographic analyses) from an apparatus operated at a reduced pressure, a typical syringe proves to be ineffective (even if it is equipped with a gas tight plunger). It simply does not create enough pressure differential to remove a fluid sample from a reduced pressure environment. We encountered such a situation as part of efforts to extend the operation of the advanced distillation curve protocol to reduced pressures. The problem was solved by the development of a pressure balance syringe that allows reliable and precise sampling from an apparatus operating at sub-ambient pressures. This new device uses an external vacuum source to evacuate a syringe barrel, allowing a user to withdraw fluid samples from environments with pressures as low as 0.5kPa. To demonstrate the operation of the ...
Singlet oxygen generators are multiphase flow chemical reactors used to generate energetic oxygen to be used as a fuel for chemical oxygen iodine lasers. In this paper, a theoretical model of the generator is presented along with its solutions over ranges of parameter space and oxygen maximizing optimizations. The singlet oxygen generator (SOG) is a low-pressure, multiphase flow chemical reactor that is used to produce molecular oxygen in an electronically excited state, i.e. singlet delta oxygen. The primary product of the reactor, the energetic oxygen, is used in a stage immediately succeeding the SOG to dissociate and energize iodine. The gas mixture including the iodine is accelerated to a supersonic speed and lased. Thus the SOG is the fuel generator for the chemical oxygen iodine laser (COIL). The COIL has important application for both military purposes--it was developed by the US Air Force in the 1970s--and, as the infrared beam is readily absorbed by ...
The results of the thermo-hydro-mechanical (THM) study of the FEBEX bentonite performed during FEBEX II are presented. The laboratory test program continued in part with the works carried out during FEBEX I, particularly in activities related to tests aimed to the calibration of the models, the acquisition of parameters by back-analysis and the improvement of the knowledge on the behaviour of expansive clays. But the program has also included tests on new areas: investigations about the influence of the microstructure changes in bentonite, of temperature and of the solute concentration on the behaviour of clay. Besides, several tests were proposed in order to understand the unexpected behaviour observed in the mock-up test, towards the end of year 2. Temperature effects on water retention curves in confined and unconfined conditions were determined, and swelling pressure, hydraulic conductivity and swelling and consolidation strains as a ...
Sexual pressure among young urban women represents adherence to gender stereotypical expectations to engage in sex. Revision of the original 5-factor Sexual Pressure Scale was undertaken in...Full Text Available
A new method is described for continuously measuring cell turgor pressure (P), hydraulic conductivity (Lp), and volumetric elastic modulus (ε) in higher plant cells, using a pressure...Full Text Available
Purpose: To enable safety reactor shut down upon occurrence of an abnormal excess pressure in a hydraulic control unit. Constitution: The actuation pressure for a pressure switch that generates a scram signal is set lower than the release pressure set to a pressure release valve. Thus, if the pressure of nitrogen gas in a nitrogen container increases such as upon exposure of the hydraulic control unit to a high temperature, the pressure switch is actuated at first to generate the scram signal and a scram valve is opened to supply water at high pressure to control rod drives under the driving force of the nitrogen gas at high pressure to rapidly insert the control element into the reactor and shut down it. If the pressure of the nitrogen gas still increases after the scram, the ...
OBJECTIVE: The risk of cardiovascular and renal diseases has been shown to be higher for systolic blood pressure than diastolic blood pressure. The aim of this study was to assess the differential control...Full Text Available
A technique for quantitative determination of cephalothin and desacetylcephalothin in serum using a method based on high-pressure liquid chromatography is described. Both compounds were quantitatively...Full Text Available
The hydraulic characteristics of flow control multiorifice plate assemblies designed for the FFTF reactor were investigated. The pressure drop flowrate characteristics determined in the test are presented. (JWR)
We describe the stabilization by pressure of enzymes, including a hydrogenase from Methanococcus jannaschii, an extremely thermophilic deep-sea methanogen. This is the first published...Full Text Available
When withdrawing a fluid sample (for additional chromatographic analyses) from an apparatus operated at a reduced pressure, a typical syringe proves to be ineffective (even if it is equipped with a gas tight plunger). It simply does not create enough pressure differential to remove a fluid sample from a reduced pressure environment. We encountered such a situation as part of efforts to extend the operation of the advanced distillation curve protocol to reduced pressures. The problem was solved by the development of a pressure balance syringe that allows reliable and precise sampling from an apparatus operating at sub-ambient pressures. This new device uses an external vacuum source to evacuate a syringe barrel, allowing a user to withdraw fluid samples from environments with pressures as l...
SUMMARYThe aim of this study was to determine middle ear pressure changes during the operation performed under anaesthesia induced by isoflurane or desflurane. This was a prospective,...Full Text Available
It is an object of the present invention to provide an improved installation having a pressurized fluid circuit incorporating fluidic brakes for restricting fluid flow through a breach of the installation. (author).
Background:Cemented hip arthroplasty is an established treatment for femoral neck fracture in the mobile elderly. Cement pressurization raises intramedullary pressure and...Full Text Available
aerodynamic force and moment values. Only the solid and the 25 percent porous dishes were tested for the static pressure values used primarily to determine ...
In this paper, we investigate the relationship between the subprime asset-backed collateralized debt obligations (CDO) market and Large Complex Financial Institutions (LCFIs). We attempt to account for the dynamics between the ABX index returns and the banks' equity returns through conditioning our analysis on the historical correlation between the variables. Three key results emerge from the analysis. First, we find a positive correlation between movements of the ABX index and the equity returns for all the LCFIs. Second, the volatility of ABX index returns tend to be transmitted to the volatilities of the equity returns of the financial institutions. Third, ABX prices changes lead equity returns changes of the European-based LCFIs. For the US LCFIs a two-way linkage emerges.
Few major mandates were won or lost in the first quarter of 1993, as the energy industry adopted a conservative approach to its financing needs. However, indications are that energy companies are coming back to the syndicated loan market after this quiet first quarter. Already, Enron, Shell Oil and Coastal have mandated substantial new facilities. Many more companies are expected back in the market over the new few months, including at least one jumbo for a major international name. A number of the industry's top names report that pricing is once again getting more aggressive in response to the high level of liquidity among lenders and a shortage of new mandates over the last few months. (Author)
Maldives comprise some of the most characteristic and significant atoll systems, but the meiobenthic assemblages of these islands are still largely unknown. A study on meiofauna was conducted on three Maldivian sandy back-reef platforms differently exposed to stronger westerly monsoons. Clear high energy effects of the waves causing currents and erosions were observed at the completely exposed and isolated offshore reef of Thoddoo Island. Wave energy of medium intensity was confirmed at Rasdhoo by depositional structures (finolhu), while a medium to low energy level was recorded at Gulhi on the basis of the presence of a low sandy bar. The meiofaunal assemblage counted 17 major taxa. Copepods and nematodes were dominant, followed by platyhelminthes and polychaetes. The nematode assemblage ...
Making use of a lead slowing-down spectrometer coupled to a 46 MeV electron linear accelerator and a back-to-back type double fission chamber, the fission cross sections of Am-241, Am-242m and Am-243 have been measured relative to that of U-235 from 0.1 eV to 10 keV with the energy resolution of about 40 % full width at half maximum. Each of the measured result has been compared with (1) the evaluated nuclear data in ENDF/B-VI and JENDL-3.2, and (2) the existing experimental data, for which the evaluated and the experimental data were broadened by the energy resolution function of the spectrometer. (author)
Making use of a back-to-back type double fission chamber and a lead slowing-down spectrometer driven by a 46 MeV electron linear accelerator, the fission cross sections of Am-241, Am-242m and Am-243 have been measured relative to that of U-235 from 0.1 eV to 10 keV with the energy resolution of about 40 % full width at half maximum. Each of the measured result has been compared with (1) the evaluated nuclear data in ENDF/B-VI and JENDL-3.2, and (2) the existing experimental data, whose evaluated and measured data were broadened by the energy resolution function of the spectrometer.
Making use of a back-to-back type double fission chamber and a lead slowing-down spectrometer driven by a 46 MeV electron linear accelerator, the fission cross sections of Am-241, Am-242m and Am-243 have been measured relative to that of U-235 from 0.1 eV to 10 keV with the energy resolution of about 40% full width at half maximum. Each of the measured result has been compared with (1) the evaluated nuclear data in ENDF/B-VI and JENDL-3.2, and (2) the existing experimental data, whose evaluated and measured data were broadened by the energy resolution function of the spectrometer. (author)
Timely detection of the pneumatic system problems is important in industry. Many techniques have been employed to solve this problem. In this paper, Genetic Algorithm (GA) based optimal configuration of neural networks is proposed for fault diagnostic of bottle filling systems. Back-propagation is used for neural networks algorithm. The back-propagation algorithm had six inputs and one output. A fitness function was designed to the minimize execution time of ANN model by keeping the number of hidden layer(s) and nodes as low as possible while the mean square error of estimated output error is minimized. The designed GA-ANN combination and the graphical user interface (GUI) eliminate the trial and error process for selection of the fastest and most accurate configuration. The performance of...
The plastic deformation behavior of formed CICC for the superconducting Tokamac fusion device was examined and appropriate manufacturing information was provided. A relation between travel of the bending roller and spring back displacement was obtained via virtual manufacturing. The radius of CICC after forming was expressed as a function of the bend-roll travel. The maximum von Mises stress after spring back was also monitored for the SAGBO prediction. Next, the variation of the CICC cross-sectional area was examined during the first turn and during conduit bending with the largest curvature. Finally, the coil radius was measured and compared with the data generated from the virtual manufacturing. The measured data showed similar pattern as predicted one. Using the mapping function found to match with the real data, the data from the virtual manufacturing may facilitate accurate manufacturing.
The plastic deformation behavior of formed CICC for the superconducting Tokamac fusion device was examined and appropriate manufacturing information was provided. A relation between travel of the bending roller and spring back displacement was obtained via virtual manufacturing. The radius of CICC after forming was expressed as a function of the bend-roll travel. The maximum von Mises stress after spring back was also monitored for the SAGBO prediction. Next, the variation of the CICC cross-sectional area was examined during the first turn and during conduit bending with the largest curvature. Finally, the coil radius was measured and compared with the data generated from the virtual manufacturing. The measured data showed similar pattern as predicted one. Using the mapping function found to match with the real data, the data from the virtual manufacturing may facilitate accurate manufacturing.
Recently, applying the novel data mining techniques for evaluating enterprise financial distress has received much research alternation. Support Vector Machine (SVM) and back propagation neural (BPN) network has been applied successfully in many areas with excellent generalization results, such as rule extraction, classification and evaluation. In this paper, a model based on SVM with Gaussian RBF kernel is proposed here for enterprise financial distress evaluation. BPN network is considered one of the simplest and are most general methods used for supervised training of multilayered neural network. The comparative results show that through the difference between the performance measures is marginal; SVM gives higher precision and lower error rates.
Hydrogen (H) plasma treatment, oxygen (O) plasma treatment and water (H_2O)-vapor heat treatment for polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) have been analyzed by separately extracting trap density at a front silicon-oxide interface (D_F) and trap density at a back interface (D_B). It is found that the H plasma treatment is apt to generate D_F and D_B. The O plasma treatment reduces D_F, while the H_2O-vapor heat treatment reduces both D_F and D_B. Improvement of transistor characteristics of poly-Si TFTs depends on understanding these results.
Fermented sausages were produced with 25%, 50%, 75% or 100% of their pork back fat content replaced by amorphous cellulose gel. The sausage production was monitored with physical, chemical and microbiological analyses. The final products were submitted to a consumer study, and the volatile compounds of the final products were extracted by solid-phase microextraction and analyzed by GC/MS. The reformulated fermented sausages had significant reductions in fat and cholesterol, and the volatile compounds derived from lipid oxidation were also reduced in the final products. These results suggest that the substitution of up to 50% of the pork back fat content by amorphous cellulose gel can be accomplished without a loss of product quality, enabling the production of fermented sausages with the l...
In the year 2008, the high pressure partial turbine and two low pressure partial turbines in the hard coal power station Bergkamen (Federal Republic of Germany) were modernized. A three-dimensional blade design and innovative seals were used. This resulted into a distinct increase in efficiency among other things.
We report resistivity and thermopower measurements of the heavy fermion compound CePd{sub 2}Si{sub 2} at pressures up to 56 kbar. At pressures from 21 to 34.5 kbar, we measured the resistivity down to 30 mK, for all other pressure steps the temperature range was 1.2-300 K. (orig.).
We report resistivity and thermopower measurements of the heavy fermion compound CePd_2Si_2 at pressures up to 56 kbar. At pressures from 21 to 34.5 kbar, we measured the resistivity down to 30 mK, for all other pressure steps the temperature range was 1.2-300 K. (orig.).
... This course is jointly taught between the School of Civil Engineering and the Environment and the School of Ocean and Earth Sciences. Scholarships 2 UK/EU fees only Scholarships are available for the academic year 2010/11. Awards will be given on the basis of merit. Flexible part-time study route available Back to top Home | About Us | Prospective Students |...
Several systems have been developed to accomplish vehicle location. The systems consist of three types: Dead Reckoning, Satellite, and LORAN C. If the information is to be sent back to a central location, some type of radiocommunication system is needed. One can use the existing voice radio or add a radio system just for transmitting the data.
In a funded program at the Lawrence Livermore National Laboratory new materials and novel designs are being incorporated into a new approach to an old concept -- flywheel energy storage. Modular devices, dubbed ``electromechanical batteries`` (EMB) are being developed that should represent an important alternative to the electrochemical storage battery for use in electric vehicles or for stationary applications, such as computer back-up power or utility load-leveling.
BackgroundHamstring injuries are the most common injury in Australian Rules football. It was the aims to investigate whether a sports chiropractic manual therapy intervention protocol...Full Text Available
The propagating of tachyons in an expanding universe is discussed. It is shown that a primordial tachyon in the big-bang universe cannot survive unless it had very large energy initially. In an indefinitely expanding universe the tachyon trajectory turns back in time. This time barrier is found to exist even in the quantum mechanical discussion of tachyons. This property is used to set limits on the mass of a tachyon. The possible astronomical checks on the hypothesis that neutrinos or photons may be tachyonic are also discussed. (author).
The propagation of tachyons in an expanding universe is discussed. It is shown that a primordial tachyon in the big bang universe cannot survive unless it had very large energy initially. In an indefinitely expanding universe the tachyon trajectory turns back in time. This time barrier is found to exist even in the quantum mechanical discussion of tachyons. This property is used to set limits on the mass of a tachyon. The possible astronomical checks on the hypothesis that neutrinos or photons may be tachyonic are also discussed.
... Although the rest of the country is less affected, if UK annual feeding and milling volumes of wheat are approximately 120,000t the drought will inevitably result in a shortfall. Looking back at the 2010 season the organic arable market performed strongly, with average feed wheat values since Christmas of 𧷐/tonne - 䀆/t higher then the same period last year. This provided a profitable ...
During their life, intervertebral discs undergo degenerative changes which need not necessarily become lesions. Conventional X-rays do not provide information on the condition of the intervertebral discs, so MRT or CT are recommended as primary techniques as they are non-invasive. Invasive methods like myelography and especially discography should not be used unless a case is highly problematic. In infants with pains in the back, MRT should be carried out as early as possible as there is nearly always an organic cause. (orig.)
The objective of this project is the development of a new class of metalloporphyrin materials used as catalsyts for use in fuel cell applications. The metalloporphyrins are excellent candidates for use as catalysts at both the anode and cathode. The catalysts reduce oxygen in 1 M potassium hydroxide, as well as in 2 M sulfuric acid. Covalent attachment to carbon supports is being investigated. The computer-aided molecular design is an iterative process, in which experimental results feed back into the design of future catalysts.
How far can a stack of $n$ identical blocks be made to hang over the edge of a table? The question dates back to at least the middle of the 19th century and the answer to it was widely believed to be of order $\\log n$. Recently, Paterson and Zwick constructed $n$-block stacks with overhangs of order $n^{1/3}$, exponentially better than previously thought possible. We show here that order $n^{1/3}$ is indeed best possible, resolving the long-standing overhang problem up to a constant factor.
In the 21st century, eighty years after William Baer presented his groundbreaking work treating bone and soft tissue infections with live maggots, thousands of therapists around the globe have rediscovered...Full Text Available
... In order to produce organic livestock feed, feed mills must be inspected and certified. If they produce both organic and non-organic feed, they must implement procedures, backed up by records, to prevent the commingling of organic and non-organic feed. This includes steps to clean storage bins and mixing and bagging equipment prior to producing batches of organic feed. Organic feed mills also must prevent ...
Late last year the Wolsung Candu in Korea suffered an incident which resulted in heavy water being released from the primary system into the containment. With the unit now back at full power, this article examines the causes of the incident and the action which is being taken to prevent it happening again. (author).
Implementation of an adaptive power system stabilizer (PSS) based on linear optimal control is described in this paper. The generator is identified in real time, and a special 3rd order discrete Riccati equation is solved in each sample interval. Because the output of the generator is fed back directly, the controller can track the system very fast. Experimental studies on a physical model of a power system demonstrate the effectiveness of the proposed adaptive optimal controller.
This paper presents general considerations concerning the application of artificial neural networks algorithms, more specifically the back-propagation learning algorithm and feed-forward multi-layer networks, to several problems in power system. The main application in power systems is the load forecasting, and two solution methods are used to solve it. (author). 45 figs., 32 tabs., 144 refs.
We attempt to image the rupture propagation of the 2004 M6.0 Parkfield earthquake by analyzing records from the USGS Parkfield seismic array (UPSAR) and other strong-motion stations. The UPSAR array consists of 12 stations distributed over about one square kilometer at a distance of 10~km from the San Andreas fault near Parkfield, California. We employ a method that uses reverse time migration to stack the seismograms at back-projected locations along the fault. We use waveform cross-correlation to align the initial P-wave arrivals and correct for small static time shifts in the records. This forces a coherent image at the hypocenter at the quake origin time. Initial results at later time steps show some evidence of the expected rupture propagation to the north. However, the resolution of the back-projection is limited by the small aperture of the UPSAR array. Records from other strong-motion stations can improve the theoretical resolution ...
First Solar made 9 CdTe PV devices; found two front- and one back-side structures that show improved Jsc and Voc, respectively, compared to base device structure; best cell efficiency was 14.13%.
The purpose of this study was to investigate the feasibility and the optimal conditions of radiofrequency (RF) ablation by using the stent-type electrode upon the saphenous vein of goats for the endovenous treatment of varicose veins. A self-expandable nitinol stent electrode (6 mm diameter, 2 cm length, cell size; 1.3 x 2 mm) was designed to expose the distal 1 cm segment to allow for contact with the venous wall. The proximal part of the electrode was connected to the RF generator by insulated copper wires located within the stent electrode introducer. Initially, to optimize the power setting, ablation of 6 saphenous veins in 3 goats was performed with power settings of 10, 20 and 30 W. Pull back rate of the electrode was 2 and 4 cm/min for each power level, respectively. The goats were sacrificed 4-6 weeks later and histologic examinations of the saphenous veins were done. For the second part of the experiment, RF ablation of 4 saphenous veins from 2 goats was ...
This booklet familiarizes the reader with DOE's Quality Assurance Rule and Order. Underlying this Training Briefing is the premise that the Rule and Order have antecedents going back to the original Quality Assurance Programs that were written when nuclear power was just being developed for commercial purposes. While a lot has changed since then, much has not.
In connection with the Public Inquiry into the CEGB proposal to build a pressurised water reactor at Sizewell in Suffolk, the case for nuclear power is examined under the headings: the economics of nuclear power - how they would like them to be; systems analysis - net effective cost; CEGB prejudices the results (comparison with coal-fired plants; forecasting on various assumptions); discounting future costs; back-end costs soar (reprocessing); real reprocessing costs; AGR costs balloon.
Several recently introduced 'new' techniques in computed tomography - iterative reconstruction, gated cardiac CT, multiple-source, and dual-energy CT - actually date back to the early days of CT. We review the historic origins and evolution of these techniques, which may provide some insight into the latest innovations in commercial CT systems. (orig.)
Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4? geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon.
Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4{pi} geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon. (orig.).
Ionization counters employing Bragg curve spectroscopy have been constructed for use in a 4#pi# geometry. These detectors compare very favorably in terms of both energy and charge resolution with small solid angle devices. These detectors have a large dynamic range because they are backed by scintillation detectors, and are thus capable of detecting and identifying particles with energies from 1 MeV/nucleon up to 200 MeV/nucleon. (orig.).
... There is an evident, growing public discontent among supervisors and regulators with quantitative risk evaluation techniques, including Value-at-Risk and similar methods, so it is surprising to see the same authorities now advocating their use in more doubtful circumstances to risk weight bonuses. Deferrals and claw backs ...
A novel approach is presented to extract relevant parameters associated with the energy loss of ejectiles from nuclear reactions obtained by digitizing the signals of a Bragg curve spectrometer. New and more powerful computational paradigms allow a more thorough pulse-shape analysis. This is fulfilled using a back-propagation artificial neural network as a pattern identifier. The known problem of over-training is discussed.
Here we show that self-propulsion in quantum vacuum may be achieved by rotating or aggregating magneto-electric nano-particles. The back-action follows from changes in momentum of electro-magnetic zero-point fluctuations, generated in magneto-electric materials. This effect may provide new tools for investigation of the quantum nature of our world. It might also serve in the future as a "quantum wheel" to correct satellite orientation in space.
Abstract. The pathogenesis of normal (intraocular) pressure glaucoma has remained unclear so far. As hospital-based studies showed an association of normal-pressure glaucoma with low systemic blood pressure, particularly at night, and with vasospastic symptoms, it has been hypothesized that a vascular factor may play a primary role in the pathogenesis of normal-pressure glaucoma. That assumption may, however, be contradicted by the morphology of the optic nerve head. Eyes with normal-pressure glaucoma and glaucomatous eyes with high-intraocular pressure can show a strikingly similar appearance of the optic nerve head, including a loss of neuroretinal rim, a deepening of the optic cup, and an enlargement of parapapillary atrophy. These features, however, are not found in any (other) vascula...
The relationship of lead exposure to blood pressure has been examined in a longitudinal study of a cohort of 89 Boston, Massachusetts, policemen. At the baseline examination, subjects had a blood lead determination and three consecutive blood pressure measurements. Triplicate blood pressure measurements were also taken at years 3, 4, and 5. Multivariate analysis revealed that, after correction for previous systolic blood pressure, body mass index, age, and smoking, a high level of blood lead was a significant predictor of subsequent elevation of systolic pressure. Bootstrap simulations of these models provided supporting evidence for the observed associations. These data suggest that lead exposure can significantly affect systolic pressure.
Experiments have been conducted to study the effect of injection pressure on the combustion process and exhaust emissions of a direct injection diesel engine fueled with Orange Skin Powder Diesel Solution (OSPDS). Earlier investigation by the authors revealed that 30% OSPDS was optimum for better performance and emissions. In the present investigation the injection pressure was varied with 30% OSPDS and the combustion, performance and emissions characteristics were compared with those of diesel fuel. The different injection pressures studied were 215bar, 235bar and 255bar. The results showed that the cylinder pressure with 30% OSPDS at 235bar fuel injection pressure, was higher than that of diesel fuel as well as at other injection pressures. Similarly, the ignition delay was longer and wi...
Material degradation of pressure tubes, which are the most important components in CANDU fuel channel, can only be evaluated by removing and examining them(material surveillance). This study aimed at establishment of overall evaluation technology including the evaluation of the material degradation for the integrity of pressure tubes of Wolsung units. Material tests for pressure tubes were performed as follows; (1) Evaluation on life limiting factors of pressure tubes (2) Review on leak-before-break and integrity maintenance technology of pressure tubes (3) Survey on selection criteria for tubes to be inspected and on related regulations for material surveillance (4) Analysis of material surveillance test procedure (5) Basic examinations of Wolsung unit 1 pressure tube material(TEM, texture, chemical component etc) (6) Manufacture of test equipments and test ...
Two-phase pressure drop and fluctuating static pressures were measured in a small horizontal rectangular channel (hydraulic diameter = 5.44 mm). The two-phase fluid was an air/water mixture at atmospheric pressure tested over a mass flux range of 50 to 2,000 kg/m[sup 2] [center dot] s. Two-phase flow patterns were identified and an objective method was found for determining the flow pattern transition from bubble or plug flow to slug flow. The method is based on an RMS static pressure measurement. In particular, it is shown that the transition is accompanied by a clear and abrupt increase in the RMS pressure when plotted as a function of mass quality. Use of the RMS pressure as a two-phase flow pattern transition indicator is shown to have advantages over pressure-versus-time trace evaluations reported in the literature. The transition is ...
The optical pressure exerted o a thin film, which is locked in the evanescent field formed at the plane interface with a totally-reflected Gaussian beam, is investigated. Some calculations of the pressure on the film caused by the evanescent field are presented in the different conditions of film thickness, film position, incident angle and polarization of a gaussian beam. The results show that the pressure exertion on the thin film can change from pushing to pulling as the parameters are varied. In particular, we find that the direction of optical pressure can act oppositely at the different positions of the film surface in the evanescent field.
To improve operational safety of the fuel channel for Wolsung units the recommended primary heat transport system (PHTS) operating guidelines were developed, which provides a safe operation window in terms of pressure and temperature to maintain fuel channel integrity, which is similar to pressure-temperature curves used for primary pressure boundary integrity in PWRs and deterministic Leak-Before Break (LBB) analyses were conducted using recent understanding of delayed hydride cracking (DHC) mechanism. In addition, a comparative assessment of LBB analysis was made using the procedures of Fitness For Service Guidelines(FFSG) for pressure tubes rev. 0 and rev. 1.
Several fast neutral pressure gauges have been installed on NSTX [National Spherical Torus Experiment] to measure the vessel and divertor pressure during inductive and coaxial helicity injected (CHI) plasma operations. Modified, PDX [Poloidal Divertor Experiment]-type Penning gauges have been installed on the upper and lower divertors. Neutral pressure measurements during plasma operations from these and from two shielded fast Micro ion gauges at different toroidal locations on the vessel mid-plane are described. A new unshielded ion gauge, referred to as the In-vessel Neutral Pressure (INP) gauge is under development.
A cellular membrane exchanges substances into and from the cell and protects the cell interior by maintaining semi-fluidity rather than be being solid. It is known that microorganisms maintain the fluidity in correspondence with varying environmental temperatures by changing and adjusting the composition of fatty acids which constitute the cellular membrane lipids. As part of the studies to elucidate the pressure withstanding mechanism in deep-sea bacteria, this paper investigates what variations the fatty acid composition, which constitutes cellular membranes of the DSS12 strain, a pressure withstanding bacterium growing well under either normal pressure or high pressures, will show under different culturing temperatures and pressures. Culture under low temperatures and culture under high pressures increase content of unsaturated fatty acids including ...
A new two-phase friction multiplier correlation has been developed to predict the pressure profile in two-phase flow with heat addition. The main difference from other pressure drop prediction routines is that in addition to the effect of quality, the effects of system pressure, heat and mass flux on the two-phase multiplier are included. The inception of two-phase flow is defined to occur at the onset of significant void in the subcooled boiling regime instead of the boundary between negative and positive thermodynamic equilibrium quality. Pressure drop data from an experiment with a fully segmented 6-metre long, 37-element fuel string were used to optimize the constants and exponents of this correlation for the friction multiplier. This pressure drop prediction technique was shown to successfully predict the measured pressure profiles. The more than one ...
In the early sixties it was decided to investigate salt formations on its suitability to host heat generating radioactive waste in Germany. In the reference repository concept consequently the emplacement of vitrified waste canisters in deep vertical boreholes inside a salt mine was considered whereas spent fuel should be disposed of in self shielding casks (type POLLUX) in horizontal drifts. The POLLUX casks, 65 t heavy carbon steel casks, will be laid down on the floor of a horizontal drift in one of the disposal zones to be constructed in the salt dome at the 870 m level. The space between casks and drift walls will be backfilled with crushed salt. The transport, the handling und the emplacement of POLLUX casks were subject of successfully performed demonstration and in situ tests in the nineties and resulted in an adjustment of the atomic law. The borehole disposal concept comprises the emplacement of unshielded canisters with vitrified HLW in boreholes with a diameter of 60 cm and ...
The pressure dependence of the photoluminescence (PL) transition associated with the fundamental band gap of ZnO nanowires has been studied at pressures up to 15 GPa. ZnO nanowires are found to have a higher structural phase transition pressure around 12 GPa as compared to 9.0 GPa for bulk ZnO. The pressure-induced energy shift of the near band-edge luminescence emission yields a linear pressure coefficient of 29.6 meV/GPa with a small sublinear term of -0.43 meV/GPa{sup 2}. An effective hydrostatic deformation potential -3.97 eV for the direct band gap of the ZnO nanowires is derived from the result.
Fresh and fresh-cut tomatoes have been associated with numerous outbreaks of salmonellosis in recent years. One effective post harvest treatment to reduce Salmonella enterica in tomatoes may be high pressure processing (HPP). The objectives of the study were to determine the potential for HPP to reduce S. enterica serovars Newport, Javiana, Braenderup and Anatum in tryptic soy broth (TSB) and to determine the effect of HPP to reduce the most pressure resistant of the four serovars from fresh diced and whole tomatoes. To evaluate pressure resistance, TSB containing 8 log CFU/ml of one of the four serovars was packaged in sterile stomacher bags and subjected to one of three different pressures (350, 450 or 550MPa) for 120s. The most pressure resistant S. enterica serovar evaluated was Braend...
A method is described for controlling fuel injection in a diesel engine having a fuel injection nozzle, comprising the steps of: detecting an idling state of the diesel engine and pressure in a combustion chamber; obtaining a pressure increment rate from the pressure detected by the detecting step; selecting a valve opening pressure of the fuel injection nozzle at a relatively low level when the idling state is detected by the detecting step, thereby setting a two peaks characteristics of a fuel injection rate; and controlling the fuel injection nozzle in response to the pressure increment rate so that the pressure increment rate in the combustion chamber is maintained within a predetermined value by changing a fuel injection quantity of a pilot injection from the fuel injection nozzle.
Measurements of the statistical characteristics of channel wall static pressure fluctuations in parallel one-component boiling flow are reported. The measurements span a wide range of local subcooling and vapor volume fraction, and correspond to flow regimes ranging from highly subcooled bubbly to saturated slug-annular. Vapor volume fraction measurements at the pressure measurement station are also reported in conjunction with visual observation of the flow structure. Variation of static pressure fluctuation intensity and spectral content with local thermal-hydraulic condition is demonstrated. Finally, it is suggested that diagnosis of local two-phase flow regime on the basis of (i) statistical characteristics of the pressure data, and (ii) time trace of pressure signal, may be possible. 15 refs.
Ab initio lattice dynamics based on linear response method are performed for high pressure phase of yttrium to describe electron-phonon coupling and subsequent superconducting behavior. The critical temperature Tc in fcc-Y increases monotonically with pressure up to 9.25 K at 31 GPa, which is quantitatively in excellent agreement with two quasihydrostatic experiments and is qualitatively compatible with recent experiments. The excellent agreement with experiments gives us a better understanding of the effective pseudopotential ?* as well as spectral function ?2(?)F(?) in yttrium. These results demonstrate that there exists strong electron-phonon coupling in Y within the studied pressure regime, and for lower pressure electron correlation becomes stronger. Generally, it is found that superconductivity in yttrium under pressure can be described quantitatively within standard theory of ...
Many older homes are equipped with mercury-containing gas regulators that reduce the pressure of natural gas in the mains to the low pressure used in home gas piping. Removal of these regulators can...Full Text Available
OBJECTIVE--To examine the effect of a reduced sodium and increased potassium and magnesium intake on blood pressure. DESIGN--Randomised double blind placebo controlled trial. SETTING--General population...Full Text Available
A combination of degenerate four-wave mixing spectroscopy and a low-pressure sampling technique has been studied for isotopic analysis in an air-acetylene flame. Hyperfine spectra of D lines of sodium and several mixtures of lithium isotopes obtained in this way are presented.
This patent describes a nuclear system comprising a containment airspace in which a nuclear reactor pressure vessel is disposed there being a reactor core within the pressure vessel. It comprises a heat exchanger elevated a distance above the pressure vessel; a pool of water surrounding the heat exchanger; means for venting the pool of water to an environment outside the containment; a heat exchanger entry conduit within the containment, the entry conduit having an open lower end communicating with the containment space, and an upper end connected to the heat exchanger, water-containing heated fluid present in the containment airspace incident a pressure vessel loss of coolant event entering and flowing through the entry conduit into the heat exchanger for cooling the fluid to convert water vapor therein to a condensate and separate non-condensable gasses therefrom; a gravity driven cooling water ...
ObjectiveTo evaluate the effectiveness of a community pharmacist–based home blood pressure (BP) monitoring program.DesignTrial of a high-intensity...Full Text Available
INTRODUCTION:Gynura procumbens has been shown to decrease blood pressure via inhibition of the angiotensin‐converting enzyme. However, other mechanisms that...Full Text Available
Purpose.To determine the effects of vasodilators on intraocular pressure (IOP) and the protein content of sheep aqueous humor (AH), because the vasodilators may increase fluid leakage...Full Text Available
A rise in blood pressure associated with oral contraceptives is well established but the frequency with which it develops is not known. Early results from a controlled long-term prospective study have...Full Text Available
AbstractX-ray diffraction analysis of pressure-induced structural changes in the Aequorea yellow fluorescent protein Citrine reveals the structural basis for the continuous...Full Text Available
Cells of the terrestrial plant species bromegrass (Bromus inermis L.) are not naturally adapted to withstand the hydrostatic pressures encountered in aquatic environments. However,...Full Text Available
On the basis of the analysis of chemical components of the natural limestones from different deposits in China, the pore structures of the typical limestones, with the different CaCO3 content, were examined. The reactivity of the limestones was investigated by sulfuric acid titration and gas-liquid absorption methods. The research results showed that the specific surface area of the natural limestones studied in this work was about 1.8 m2/g. It was seen that the pH of the limestone slurry rapidly decreased and then back up when the sulfuric acid was added. The higher the CaCO3 content was, or the smaller the particle size was, the larger the pH back-up rate was, and similarly the faster the SO2 concentration of the reactor outlet increased. The Reactivity of the limestone obtained by the sulfuric acid titration had the same features as that obtained by the gas liquid absorption. Compared with the specific surface area, the CaCO3 content had ...
In January 2001, Husky Oil Operations Limited (Husky), in joint-venture with Petro-Canada submitted a Development Application (DA) to the Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB) for the White Rose Development. This DA was prepared following the Canada-Newfoundland Atlantic Accord Implementation Act and the Canada-Newfoundland and Labrador Atlantic Accord Implementation Newfoundland and Labrador Act. In December 2001, the C-NLOPB approved the White Rose DA. This document outlined a proposed amendment to the original Development Plan involving an expansion of its White Rose Development in the Jeanne d'Arc Basin on the Grand Bank. The expansion will consist of a subsea tie-back to the Floating Production, Storage and Offloading (FPSO) vessel through the existing Southern Glory Hole (SGH) and utilizing a new glory hole constructed approximately 4 km south of the SGH. The document presented an overview of the development; geology, ...
Pain is necessary for survival but chronic pain is disabling and causes significant health and economic problems. This study provides an understanding of the future for spinal cord stimulation. Stimulation by means of chronically implanted electrodes, was carried out in 200 patients with pain of varied benign organic etiology. In 177 of them, pain was confined to the failed back syndrome. Most patients were referred by a Pain Management Service. 226 epidural implants were used: 80 unipolar, 59 Resume, 12 bipolar, and 75 quadripolar. Patients were followed for periods of 6 months to 12 years, with a mean follow-up of 44 months. 84 patients (42%) were able to control their pain by stimulation alone, 22 patients (11%) needed occasional analgesic supplements along with their stimulation program. Pain secondary to failed back syndrome, multiple sclerosis, peripheral vascular disease, sympathetic dystrophy and diabetic neuropathy responded favorably. ...
Tripartite efflux systems are responsible for the export of toxins across both the inner and outer membranes of Gram negative bacteria. Previous work has indicated that EmrAB-TolC from Escherichia coli is such a tripartite system, comprised of EmrB an MFS transporter, EmrA, a membrane fusion protein and TolC, an outer membrane channel. The whole complex is predicted to form a continuous channel allowing direct export from the cytoplasm to the exterior of the cell. Little is known, however, about the interactions between the individual components of this system. Reconstitution of EmrA + EmrB resulted in co-elution of the two proteins from a gel filtration column indicating formation of the EmrAB complex. Electron microscopic single particle analysis of the reconstituted EmrAB complex revealed the presence of particles approximately 240 x 140 A, likely to correspond to two EmrAB dimers in a back-to-back arrangement, suggesting the dimeric EmrAB form is the ...
In the development of the man-made island siting technology of nuclear power plants, assessing the stability of the seawall against large ocean waves and earthquakes is indispensable. Concerning with the seismic stability of the seawall, prediction of the deformation like sliding and settlement of the seawall during earthquake including the armour units in front of the caisson becomes important factor. For this purpose, the authors have developed the two-dimensional DEM-FEM coupled analysis method (SEAWALL-2D) to predict the deformation of the seawall covered with the armour units during earthquake. In this method, movements of the armour units are calculated in DEM analysis part and deformation of the caisson, rubble moundsand seabed and back fill are calculated in FEM analysis part taking the nonlinearity of the soil materials based on the effective stress into account. Numerical simulations of dynamic centrifuge model tests of the seawall are conducted to verify ...
After the construction of its wastewater treatment plants, the City of Quebec began to implement overflow control in wet weather to ultimately meet the effluent discharge objectives, i.e. no more than two overflows per summer season in the St. Lawrence River and no more than four in the St-Charles River. After several years of studies to determine which management strategies would best suit the purpose, and to propose optimum solutions, a first project to implement optimal and predictive management in real time, called "Pilot", came to life in 1999. Construction in phases soon followed and the work was completed in the fall of 2009. As a result, requirements with regard to environmental rejects were met in two sectors, namely the St-Charles River and the Jacques-Cartier Beach, and aquatic recreational activities could resume. Meanwhile, the City also worked at giving back access to the water courses to the public by developing sites at the Jacques-Cartier Beach and ...
Dutch-style fermented sausages were manufactured with 15% and 30% pork back-fat substitution by pure or commercial encapsulated fish oil, either added as such or as pre-emulsified mixture with soy protein isolate. Adding commercial encapsulated fish oil was the most important factor influencing the chemical composition. The fat content was not significantly different between products (p>0.05). The n-6/n-3 ratio decreased from 8.49 in controls to 0.90-2.47 in modified products. Lipid oxidation parameters (propanal and hexanal) showed much higher values for sausages with pure fish oil than for products with encapsulated oil. For the latter, lipid oxidation was similar to controls. Products with encapsulated or pre-emulsified oil were significantly firmer than products from other treatments i...
A new method for the preconcentration and determination of trace amounts of lead at the {mu}g/L level in natural waters has been established based on the formation of the thenoyltrifluoroacetone (TTA) complex with dibenzo-18-crown-6 (DB18C6) by means of synergistic extraction and back-extraction combined with atomic absorption spectrometry (AAS). The effect of various factors (synergism with TTA and DB18C6, shaking time, preconcentration factor, composition of the extracted species, and foreign ions etc.) on the extraction and back-extraction of lead has been investigated in detail. The lead-TTA chelate in o-dichlorobenzene forms a stable adduct with DB18C6 as Pb(TTA){sub 2} DB18C6. The stability constant ({beta}) of the adduct determined by curve fitting method was log {beta} = 4.2. The amount of lead in natural waters such as tap water (Kanazawa University) and Kakehashi river (Komatsu City) determined by the present method was found to be ...
Clinical circumstances often demand flexibility in electrodiagnostic procedures. We present a clinical case that required alteration of our routine full-field electroretinography technique. The patient presented with reports of allergy to Xylocaine (lidocaine) and refused the use of any type of topical anesthetic drops. This conflicted with our routine ERG method that combines the use of the Henkes Lovac hard contact lens and the topical anesthetic Alcaine (proparacaine hydrochloride). We acquired a successful electroretinogram without topical anesthesia by using a "piggy-back" system involving the interposition of a soft hydrophilic contact lens between the cornea and the recording hard lens. The procedure yielded excellent ERG recordings and was well tolerated. This non-routine technique was also compared to our standard ERG technique using a normal volunteer. It appears that this proposed "piggy-back" technique is a useful alternative to ...
It has by now been established that standard QCD factorization using transverse momentum dependent parton distribution functions fails in hadro-production of nearly back-to-back hadrons with high transverse momentum. The essential problem is that gauge invariant transverse momentum dependent parton distribution functions cannot be defined with process-independent Wilson line operators, thus implying a breakdown of universality. This has led naturally to proposals that a correct approach is to instead use a type of "generalized" transverse momentum dependent factorization in which the basic factorized structure is assumed to remain valid, but with transverse momentum dependent parton distribution functions that contain non-standard, process dependent Wilson line structures. In other words, to recover a factorization formula, it has become common to assume that it is sufficient to simply modify the Wilson lines in the parton correlation functions for each separate ...
A single-crystal x-ray study under pressure reveals a phase transition from an in-plane 2x2 commensurate potassium superstructure to a new ..sqrt..3x..sqrt..3 commensurate superstructure. This is the first such transition to be observed; it is related to the recently discovered staging transition of KC/sub 8/ under pressure. In addition this staging transition was observed to occur more slowly and at much lower pressures than in the reported neutron-scattering experiment on highly oriented pyrolytic graphite samples. 13 references, 2 figures.
... Although other authors had made cross-spectral density measurements, Corcos pointed to the importance of this function as indicative of the true ...
Isosteric heats and adsorption isotherms of methane on nanometer active carbon were measured at supercritical temperature (273-373 K) and pressure from 0 to 10 MPa. The measured data agreed well with Dubinin-Astakhov (DA) model at lower pressure but failed when pressure exceeded a special range. General Freundlich (GF) equation was used to modify the DA equation at high pressure and thus formed a combined bisection model GFDA. The adsorption mechanism of methane on nanometer active carbon was raised according to GFDA model and the heterogeneous energy distribution of the adsorbent was analyzed.
extravehicular activity; an exploding bridgewire firing unit for rocket engines ; a pressure transducer that can withstand the 6000 OF temperiiture ...
Solar heating of gas turbine plants steps back more and more into the focus of current research. The mainly instationary operation of solar turbine power plants can only be predicted with sufficient accuracy if the transient behaviour of the receiver for the solar radiation is known. Therefore the transient behaviour of cavity receivers of different design is investigated. The mathematical model used for the simulation of the heat transfer and energy storage processes is illustrated. Computed results for receivers with various inner lining are compared and evaluated concerning their use in practice.
Solar heating of gas turbine plants is moving back to the focus of current research. The mainly unsteady operation of solar turbine power plants can only be predicted with sufficient accuracy if the transient behavior of the solar radiation receiver is known. Therefore the transient behavior of cavity receivers of different designs is investigated. The mathematical model used to simulate heat transfer and energy storage is illustrated. Computed results for two receivers with different inner lining are compared and evaluated concerning their use in practice.
In the context of sputtering experiments, studying the back-scattering of fast ion beams is a useful way to study inelastic ion-surface interactions, since then the trajectories and energies of the particles are well defined. This same argument holds for the scattering of fast molecular ions. We give a short account of our experiment where N"+_2 was scattered from a Ni(111) surface. The measured energy distributions of scattered N atoms are discussed with regard to vibrational and rotational energy transfer during scattering. (G.Q.).
Alexander the Great founded Alexandria in 331 BC. The newly founded town was conceived as an orthogonal grid based on a main longitudinal axis, later called Canopic Road. We analyse here the astronomical orientation of the project and propose that the main axis was deliberately oriented towards the rising sun on the day of birth of Alexander the Great. The argument is admittedly speculative as any Archaeoastronomy argument not backed up by written sources. However, it is nested accurately into the archaeological records and into what is known on the foundation of the town. Further, a topographical analysis is given to sustain the thesis.
A nitrogen liquefier and computer controlled valving system have been added to the Bevatron cryoliner vacuum system to cut operating costs by reducing liquid nitrogen consumption. The computer and interface electronic systems, which control the temperatures of twenty-eight liquid nitrogen circuits, have been chosen and designed to operate in the Bevatron's pulsating magnetic field. The nitrogen exhaust is routed back to a liquefier, of about five kilowatt capacity, liquefied, and rerouted through the cooling circuits. A description of the system and operating results are presented.
This letter describes a new simple fabrication process, developed recently for blue response'' improvement in low-cost polycrystalline silicon solar cells. A selective emitter is created by heavily doping the emitter, followed by a wet etching-back of the cell area between the fingers. An improvement up to 17 mV in {ital V}{sub oc}, 1.5 mA/cm{sup 2} in {ital J}{sub sc}, and 1% (absolute value) in {eta} is obtained. Effective phosphorus gettering, self-alignment, and application in a low-cost full screenprinting technology are the main advantages of the proposed process.
Repair and maintenance for equipment used in the Belchatow brown coal mine and organizational models of repair services in the mine are discussed. Maintenance of earthmoving equipment, spreaders, bucket wheel excavators, loaders and other coal handling equipment, belt conveyors and drive systems for belt conveyors is discussed. Repair shops in the mine also manufacture about 35% of spare parts and elements for equipment used in the mine. Reliability of mining equipment, repairs and repair capacity of the shops are discussed. Organizational models of repair services, equipment used by these services and repair personnel are described. Effects of repair services on operation of the mine are evaluated.
Innate immune responses are regulated by microorganisms and cell death, as well as by a third class of stress signal from the nervous and endocrine systems. The innate immune system also feeds back, through the production of cytokines, to regulate the function of the central nervous system (CNS), and this has effects on behaviour. These signals provide an extrinsic regulatory circuit that links physiological, social and environmental conditions, as perceived by the CNS, with transcriptional 'decision-making' in leukocytes. CNS-mediated regulation of innate immune responses optimizes total organism fitness and provides new opportunities for therapeutic control of chronic infectious, inflammatory and neuropsychiatric diseases.
During the last few years radio and X-ray astronomers have produced high-resolution imagery of the remnant of Cas A. Since the most recent published optical photographs of Cas A date back to 1975 it seemed worthwhile to present new optical results based on plates obtained with the 5-m Hale telescope in 1976, 1977, and 1980. The major changes that have taken place in Cas A during the last decade are: (1) A broken shell of fast-moving knots has formed along the southern and SW rim of the remnant and (2) A number of blue (oxygen-rich) filaments have developed to the north of the centre of Cas A. (Auth.).
The paper deals with Hawking radiation related to non-static spherically symmetric black hole. Quantum corrections are incorporated using Hamilton-Jacobi method beyond semi-classical approximation. It is found that different order correction terms satisfy identical differential equation as the semiclassical action and are solved by a typical technique. It has been shown that with proper choice of the proportionality factors, one loop back reaction effect in the space time can be obtained. Finally, using the law of black hole mechanics, a general modified form of the black hole entropy is obtained considering modified Hawking temperature.
In the prevention of atmospheric pollution by sulfur dioxide emissions from acid absorbers in contact process sulfuric acid plants in which the unconverted SO/sub 2/ is accumulated by adsorption in a zeolite adsorbent bed and desorbed back into the acid production system, it is found that ambient moist air, after partial dehydration in an acid scrubber is suitably used both to cool down and hot purge desorb the zeolite beds. In addition the pure water derived from the ambient air is advantageously used in the acid-making system.
In this paper following a brief outline of the geological background in Greece, as related to geothermal exploration, the prospective areas for low enthalpy fluids are classified into four groups. These are the Tertiary grabens associated with Lithospheric stretching and crustal subsidence, the Arc of the Aegean Plio-Quaternary volcanism induced by the subduction of the African plate, Central Aegean islands of distensive tectonism bordering back-arc marine basins and finally Tertiary-Quaternary sedimentary basins of various types, not classified as grabens. The geothermal regime in each of these groups is outlined, and the current status of exploration is reviewed.
...The RSPB: Birds by family: Owls E-mail to a friendE-newsletterContact us Home England Northern Ireland Scotland Wales About Overview Awards & recognition Contact ...Birds by family PrintHome Birds and wildlife Bird guide Birds by family Owls Owls Owls are specialised birds with round heads and rather flat ...or dished faces, with forward-facing eyes and a short, hooked bill. Most are nocturnal or crepuscular (active at dawn and dusk)... Owls are found all over the temperate and tropical parts of the world. Barn owl With heart shaped face, buff back ...
The micropulse lidar (MPL) is a ground-based optical remote sensing system designed primarily to determine the altitude of clouds overhead. The physical principle is the same as for radar. Pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is infered. Besides real-time detection of clouds, post-processing of the lidar return can also characterize the extent and properties of aerosol or other particle-laden regions.
Spinal cord stimulation (SCS) is frequently used for relief of chronic benign pain resistant to conservative therapies. Clinical practice suggests, at least in patients with failed back surgery syndrome (FBSS), the possibility that SCS significantly improves motor performances. We present here the case of a 41-years-old female patient with FBSS, who showed a clear improvement in muscle strength after SCS, persisting at 6-months follow-up. We speculate that the electrical stimulation of posterior columns could potentiate the caudal, segmental spinal reflexes resulting in a facilitation of motoneurons activation. PMID:16175150
An improved acousto-optic laser Q-switch uses a chirped fm pulse in the acousto-optic cell to diffract and focus the input beam into a resonating high-Q mode. When the rf acoustic pulse is not wholly within the cell, the beam is diverted to the output. A reflective surface is placed on the cell to yield only one output beam and to yield a retroflective beam back into the cavity for a high Q condition whenever a correctly generated chirp acoustic wave is in the proper postion within the cell.
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The High Exposure Facility is a collimated high-level gamma irradiator that is located in the basement of the 318 building. It was custom developed by PNNL back in 1982 to meet the needs for high range radiological instrument calibrations and dosimeter irradiations. At the time no commercially available product existed that could create exposure rates up to 20,000 R/h. This document is intended to pass on the design criteria that was employed to create this unique facility, while maintaining compliance with ANSI N543-1974, "General Safety Standard for Installations Using Non-Medical X-Ray and Sealed Gamma-Ray Sources, Energies up to 10 MeV."
A #gamma##gamma# collider would extend and complement the physics capability of a linear collider; e.g. it would be suitable for direct measurement of the partial decay width of a Higgs boson into two gamma quanta. This paper discusses choice of laser parameters, luminosity optimization, electron and laser parameters for a gamma- gamma collider as a second interaction region for the Next Linear Collider, laser path, and the lasers. It is concluded that a gamma- gamma collider is technically feasible; however it will require a significant investment in preparatory R ampersand D.
The various factors that affect the open-circuit voltage ([ital V][sub oc]) of a two-terminal GaInP[sub 2]/GaAs tandem cell are examined. These include a) an anomalous problem associated with the GaAs bottom cell and b) back surface passivation of the thin GaInP[sub 2] top cell. Solutions to these problems are presented and yield tandem [ital V][sub oc]s close to the practical theoretical limits.
Recreational Programming (RecPro) is the discipline that encourages the study of computer programming through ludic problems. Problems that are typically studied within this discipline are similar to those of Recreational Mathematics (RecMat), which sometimes leads to the confusion of these two disciplines. The objective for RecPro is to write programs, while RecMat practitioners can use these programs to state (and prove if possible) conjectures about the solution. This interaction leads to a mathematical quality production. In an educational framework, problems in elemental number theory (those that are formulated with a basic knowledge of arithmetic) are very interesting, leading to the revision of classical unsolved problems. One of these problems is the general form of Zumkeller numbe...
Lumbar epidural anesthesia is useful in a variety of chronic benign pain syndromes, including lumbar radiculopathy, low back pain syndrome, spinal stenosis, and vertebral compression fractures. Given the increased number of epidural nerve blocks being performed, some have reported unexplained complications of a transient or permanent nature and with varying degrees of severity. However, no case has been reported of a broken epidural needle tip retained in the lumbar facet joint area. This represents the first reported case presentation of foraminal stenosis developing in a patient after a retained epidural needle tip. PMID:21286465
Financing space solar power generation programmes has several inherent difficulties. Such large-scale projects are usually easily defined with an expected economic return, construction time, useful service life and defined management structure. As yet, solar power satellites for power generation possess none of these as the idea exists conceptually and the technology still needs to be developed. Methods for overcoming these uncertainties and securing financial backing are described. Venture capital could finance a research/marketing firm. US Government support through a cost plus short-term monopoly to facilitate private debt financing could provide an answer. (UK)
In the framework of the Low Emittance Gun (LEG) project, high gradient acceleration of a low emittance electron beam will be necessary. In order to achieve this acceleration, a -500 kV, 250 ns FWHM, pulse will be applied between two electrodes. Those electrodes should sustain the pulsed field without arcing, must not outgas and must not emit electrons. Ion back bombardment, and dark current will be damaging to the electron source as well as for the low emittance beam. Electrodes of commercially available OFE copper, aluminium, stainless steel (SS), titanium and molybdenum were tested, following different procedures including plasma glow discharge cleaning.
Electron beam therapy has often been used for radiation therapy of carcinomas of the buccal mucosa, though side effects, including stomatitis and dermatitis, are known to exist. We experimented using the additional back scatter and transit with the phantom under a lead plate within the irradiation field, in order to better focus the dose on the target volume moreover, we fabricated a mouthpiece fitted with a lead plate shaped to the target volume, and with respect to the influence of the mouthpiece on stomatitis and dermatitis, obtained good clinical results. (author).
Electron beam therapy has often been used for radiation therapy of carcinomas of the buccal mucosa, though side effects, including stomatitis and dermatitis, are known to exist. We experimented using the additional back scatter and transit with the phantom under a lead plate within the irradiation field, in order to better focus the dose on the target volume moreover, we fabricated a mouthpiece fitted with a lead plate shaped to the target volume, and with respect to the influence of the mouthpiece on stomatitis and dermatitis, obtained good clinical results. (author).
A novel way to extract relevant parameters associated with the outgoing ions from nuclear reactions, obtained by digitizing the signals provided by a Bragg curve spectrometer (BCS) is presented. This allowed the implementation of a more thorough pulse-shape analysis. Due to the complexity of this task, it was required to take advantage of new and more powerful computational paradigms. This was fulfilled using a back-propagation artificial neural network (ANN) as a pattern identifier. Over training of ANNs is a common problem during the training stage. In the performance of the ANN there is a compromise between its size and the size of the training set. Here, this effect will be illustrated in relation to the problem of Bragg Curve (BC) identification. (Author)
Two patients are described in whom sunburn and electron beam radiodermatitis, respectively, were critical determinants in localizing the initial presentation of drug eruptions. In the first instance, a severe sunburn of the back and thighs was followed 7 months later by the appearance of a toxic epidermal necrolysis drug reaction to trimethoprim-sulfamethoxazole in the exact sites of the previous bullous sunburn reaction. In the second patient, a radiodermatitis of the left upper arm due to electron beam therapy for metastatic breast cancer was followed 7 weeks later by a codeine drug reaction confined to the area of the radiodermatitis. In both instances, oral rechallenge with the offending drug reproduced the eruption.
In the development of a geothermal heat pump a water source heat pump was connected to a 1-1/2'' water line, 2200' long, buried in an endless loop 10' deep. The system is closed, circulating the same water continuously through the heat pump back to the field again. This water line 10' deep is the geothermal heat source. No matter how cold the air temperature gets on a winter day the water temperature to the heat pump will always be above 45/sup 0/F. This system has efficiently heated our house the past year using no supplemental heat.
The exergy method is used to compare different production processes and various methods for emission abatement with respect to their overall environmental impact. Some ammonium nitrate production processes are studied as examples, because the pollutants (ammonia and ammonium nitrate), emitted from these processes into the air and/or into the water, are really a feedstock and a product from the production process. Therefore, the essential result of the waste flows treatment is the recycling of the pollutants (ammonia and ammonium nitrate) back into the production process, decreasing simultaneously the exergy input and cumulative exergy consumption. (author)
This paper deals with an artificial neural network (ANN) based adaptive conventional power system stabilizer (PSS). The ANN comprises an input layer, a hidden layer and an output layer. The input vector to the ANN comprises real power (P) and reactive power (Q), while the output vector comprises optimum PSS parameters. A systematic approach for generating training set covering wide range of operating conditions, is presented. The ANN has been trained using back-propagation training algorithm. Investigations reveal that the dynamic performance of ANN based adaptive conventional PSS is quite insensitive to wide variations in loading conditions.
The multicell proportional chambers at the backing calorimeter of the ZEUS experiment at the storage ring HERA are supplied with a gas mixture of Ar/CO[sub 2] by an open gas system. Flow proportional counters with the build-up [sup 55]Fe sources are used as gas system monitoring detectors. The ZEUS experiment is planned to collect data for about 10 years. Therefore, the lifetime of the Ar/CO[sub 2] mixture should be known. In this paper, the results of laboratory tests and preliminary measurements of the aging effects for monitoring counters are presented. ((orig.))
The technical development of electric cables in the history of the Berlin electric utilities looks back on more than one century of continuous progress from jute-insulated direct-voltage cables, to 30 kV paper-insulated mass-impregnated cables, 110 kV plastic-insulated cables, 380 kV oil-filled cables, and 380 kV XLPE cables which are increasingly used today. A brief review informs about the major stages of power cable development. (orig.).
SC-CO/sub 2/ extraction of oil from peanuts is an alternative to hexane extraction or the mechanical oil press. Oil was successfully extracted using SC-CO/sub 2/ at temperatures of 25-120/sup 0/C and pressures of 140 -690 Bar. Pressure, temperature and particle size affected the extraction of oil. In the range studied, the highest values of temperature and pressure gave highest solubilities.
A method is described for increasing pressure in geologic oil-bearing structures by gas production due to microbial activity. There is added to an oil-bearing structure an anaerobic micro-organism (Methanobacterium termoautotroficum), a culture medium and formic acid. The formic acid is converted to carbon dioxide and methane gases resulting in increased pressure in the structures. Methanobacterium termoautotroficum cannot split formic acid into CO/sub 2/ and H/sub 2/ but it can produce methane from these 2 gases. 4 claims.
The synthesis of experimental data concerning the effect of jet stagnation conditions on the drag of various afterbodies is presented. Jet pressure ratio effect on boattail pressure and on boundary layer separation is analyzed. This study is made for several values of the boundary layer thickness, taking into account the fact that some test rigs make its control possible by means of tangential blowing.
The requirements of high-pressure compressors increase. The customers wish still larger quantities of delivery with smaller employment of achievement, minimal oil consumption, service amenability, long intervals of maintenance and so forth. For this, the author of the contribution under consideration presents two series of modular developed high-pressure compressors in compact design for industrial air and technical gases which exactly fulfil these requirements.
The results of research on the evaluation of the half-bead weld repair method for use on nuclear reactor components are reviewed from data obtained on thick-section test pieces and intermediate-size pressure vessels. Material properties, the magnitude of residual stresses and the structural behavior of flawed pressure vessels are being obtained to determine the adequacy of the weld repair method for application in thick-section components.
The use of oil-filled high-pressure electric cables has increased significantly. In recent years, the electric cable industry has developed new designs, manufacturing technology, and has mastered the production of 110 to 220 kV cables without using a temporary lead sheath. The design, fabrication, and performance of high-pressure electric cables for power systems are discussed.
A new method for the separation and determination of trace amounts of cadmium and zinc in water as their thenoyltrifluoroacetone (TTA) complexes with dibenzo-18-crown-6 (DB18C6) in o-dichlorobenzene has been established by means of synergistic extraction and back-extraction combined with atomic absorption spectrometry. The effect of various factors (synergism with TTA and DB18C6, shaking time, composition of the extracted species, and mutual separation etc.) on the extraction and back-extraction of cadmium and zinc has been in- vestigated. When the mixtures were extracted for 4 min at pH 4.9, only zinc was extracted quantitatively, whereas cadmium remained in the aqueous phase. After the phases were separated, cadmium was again extracted quantitatively at pH 7.5. Then, the two phases were each shaken with 0.05-0.1 mol/l HCl in order to back-extract cadmium and zinc from the organic phases; the ions were determined ...
In January 2001, Husky Oil Operations Limited (Husky), in joint-venture with Petro-Canada, submitted a Benefits Plan for the White Rose Development to the Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB). It was prepared following the Canada-Newfoundland and Labrador Atlantic Accord Implementation Act and the Canada-Newfoundland and Labrador Atlantic Accord Implementation (Newfoundland) Act. In December 2001, the C-NLOPB approved the White Rose Benefits Plan. This document described the work that Husky proposes to undertake within its significant discovery license areas 1043 and 1044 for the development of the South White Rose Extension (SWRX) Tie-back to the White Rose Floating Production, Storage and Offloading (FPSO) vessel as it will require an amendment to the original White Rose Development Plan and is subject to the review and approval of the C-NLOPB. The statutory requirements as well as the actual policies and procedures were identified ...
We present an image of the rupture propagation of the 2004 M6.0 Parkfield earthquake using records from a dense network of local strong motion stations. We back-propagate high-frequency waveforms in 3D with a method, similar to reverse time migration, to obtain an estimate of the distribution of radiated high-frequency seismic energy in space and time. The image is forced to be coherent at the known hypocenter location and the quake origin time by applying small static time shifts obtained using waveform cross-correlation. We observe that the Parkfield earthquake radiated a distinct secondary high-frequency phase, which is located about 12.5~km northwest of the hypocenter with an onset of seismic radiation about 5~s after the rupture initiation. The time history of the back-projection suggests a rupture velocity of 2.5~km/s between hypocenter and subevent. The back-projection result is confirmed by inversion of picked ...
Raman and infrared spectroscopy of para-H{sub 2} to pressures in excess of 200GPa and to 8K using new ultrapure synthetic diamond anvils reveals numerous new vibrational excitations in the three high-pressure phases. Highly resolved Raman-active librons indicate differences in orientational ordering between phasesII and III, including evidence for changes within phaseII. The librons in phaseIII are strongly pressure dependent and reflect a substantial increase in ordering with pressure. Multiple vibrons in all three phases (I, II, and III) are observed. The results place new bounds on predicted crystal structures and dynamics of the dense molecular solid. {copyright} {ital 1997} {ital The American Physical Society}
Nanocrystalline powders of GaN with grain sizes ranging from 2 to 30 nm were examined under high external pressures by in situ diffraction techniques in a diamond anvil cell at DESY (HASYLAB, Station F3). The experiments on densification of pure powders under high pressure were performed without a pressure medium. The mechanism of generation and relaxation of internal strains and their distribution in nanoparticles was deduced from Bragg reflections recorded in situ under high pressures at room temperature. The microstrain was calculated from the full-width at half-maximum (FWHM) values of the Bragg lines. It was found that microstrains in GaN crystallites are generated and subsequently relaxed by two mechanisms: generation of stacking faults and change of the size and shape of the grains occurring under external stress. (author)
Lithium phosphorous oxynitride(Lipon) thin films as a lithium ion conductive electrolyte were prepared by radio frequency reactive sputtering in N2 plasma. The properties of the amorphous Lipon solid electrolyte were investigated as a function of N2 pressure during reactive sputtering. The ionic conductivity and the electrochemical stability of Lipon thin films improved drastically as the N2 pressure decreased. The ionic conductivity closed to 10?6 S cm?1 and obtained a stability window of 1.0?5.0 V with an N2 pressure of 5 mTorr, where the number of nitrogen bonds between the phosphate groups were more than those formed at higher pressure. It was possible to fabricate the Li//LiCoO2 complete thin film battery using this Lipon solid electrolyte, which exhibited excellent discharge characte...
Purpose: To secure the reactor operation safety by the provision of a fluid pressure detecting section for control rod driving fluid and a control rod interlock at the midway of the flow pass for supplying driving fluid to the control rod drives. Constitution: Between a driving line and a direction control valve are provided a pressure detecting portion, an alarm generating device, and a control rod inhibition interlock. The driving fluid from a driving fluid source is discharged by way of a pump and a manual valve into the reactor in which the control rods and reactor fuels are contained. In addition, when the direction control valve is switched and the control rods are inserted and extracted by the control rod drives, the pressure in the driving line is always detected by the pressure detection section, whereby if abnormal pressure is resulted, the alarm generating device is ...
BackgroundWave reflection during the systole increases left ventricular (LV) pressure, tension-time index (TTI) and myocardial oxygen requirement. The purpose of this study was to extract that component of extra myocardial oxygen requirement that is due to early systolic wave reflection, define it as wasted effort (?Ew), and examine its relationship to LV hypertrophy (LVH).MethodsRadial artery pressure waveforms were recorded using applanation tonometry and central aortic waveforms generated in 98 patients with untreated hypertension. Aortic augmentation index (AIa), wave reflection amplitude (i.e., aortic augmented pressure (AG)) and systolic duration (ED?Tr), ejection duration (ED) and round-trip travel time of the pressure wave (Tr) were calculated from the aortic waveform, a...
The method is related to hydrodynamic methods for studying wells and may be used in the prospecting and mapping of gas and gas condensate deposits and formations. The method consits of drilling exploratory wells and measurement of the physical parameters of the stratum liquid. The piezometric levels are periodically determined simultaneously in all the observation wells during a change in the atmospheric pressure, and the presence of a remoteness of the gas deposit from the well is judged from the size of the increments in the piezometric levels intime. The determinations of the piezometric levels in the wells are conducted during an abrupt change in atmospheric pressure, for instance, during the replacement of a cyclone by an anticyclone or the reverse. The atmospheric pressure is measured by a barograph, while the piezometric levels are measured by high precision level meters or pressure gauges of low ...
Experiments have been conducted to study the effect of injection pressure on the combustion process and exhaust emissions of a direct injection diesel engine fueled with Orange Skin Powder Diesel Solution (OSPDS). Earlier investigation by the authors revealed that 30% OSPDS was optimum for better performance and emissions. In the present investigation the injection pressure was varied with 30% OSPDS and the combustion, performance and emissions characteristics were compared with those of diesel fuel. The different injection pressures studied were 215 bar, 235 bar and 255 bar. The results showed that the cylinder pressure with 30% OSPDS at 235 bar fuel injection pressure, was higher than that of diesel fuel as well as at other injection pressures. Similarly, the ignition delay was longer and with shorter combustion duration with 30% OSPDS at 235 bar injection ...
In massive star formation (gsim 40 M sun) by core accretion, the direct stellar radiation pressure acting on the dust particles exceeds the gravitational force and interferes with mass accretion at the dust sublimation front, the first absorption site. Ram pressure generated by high accretion rates of 10-3 M sun yr-1 is thought to be required to overcome the direct stellar radiation pressure. We investigate the direct stellar irradiation on the dust sublimation front, including the inner accretion disk structure. We show that the ram pressure of the accretion disk is lower than the stellar radiation pressure at the dust sublimation front. Thus, another mechanism must overcome the direct stellar radiation pressure. We suggest that the inner hot dust-free region is optically thick, shielding the dust sublimation front from direct stellar irradiation. Thus, ...
San Francisco bus drivers have an increased prevalence of hypertension. This study examined relationships between blood lead concentration and blood pressure in 342 drivers. The analysis reported in this study was limited to subjects not on treatment for hypertension (n = 288). Systolic and diastolic pressure varied from 102 to 173 mm Hg and from 61 to 105 mm Hg, respectively. The blood lead concentration varied from 2 to 15 ..mu..g/dL. The relationship between blood pressure and the logarithm of blood lead concentration was examined using multiple regression analysis. Covariates included age, body mass index, sex, race, and caffeine intake. The largest regression coefficient relating systolic blood pressure and blood lead concentration was 1.8 mm Hg/ln (..mu..g/dL). The coefficient for diastolic blood pressure was 2.5 mm Hg/ln (..mu..g/dL). These findings suggest effects of lead ...
Transients induced in nuclear power plants from many sources result in one or more fluid conditions changing with time. Fluid conditions of pressure, inlet temperature, inlet flow, or even system power many change separately or in conjunction with each other. The result of the condition change may be one which induces departure from nucleate boiling. An experimental investigation of transient which were intended to achieve Critical Heat Flux was performed at the Heat Transfer Research Facility of Columbia University for Siemens Nuclear Power Corporation. The transients were set up to include broad ranges of flow and pressure conditions near the operating range of pressurized water reactors. Transient events were dominated by varying single conditions and measuring the response of the system and of the rod thermocouples. Because of coupling effects within the test loop, secondary conditions would also vary. In order to ...
In relation to coal gasification and combustion under high pressure as highly efficient coal utilization, the effect of total pressure and sintering on the SO2 capture ability of Ca-ion exchanged coal and other desulfurizing agents were studied. In experiment, specimens were filled into a small pressurized reactor to heat them under high-pressure N2 atmosphere. After the completion of combustion reaction of char at 850{degree}C, SO2, CO2 and CO gases were measured at an outlet while flowing SO2/N2. As the experimental result, all of the S content in Ca-ion exchanged coal was not absorbed by Ca content in coal during pyrolysis and combustion, resulting in discharge of 36% of the S content. Since Ca-ion exchanged coal is fast in combustion reaction, most of the S content was desulfurized by coal ash. The ash content yielded from Ca-ion exchanged coal was more excellent in SO2 capture ability than ...
The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU's evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky trademark pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is ...
TaC and TaC-1wt.% B4C powders were consolidated using spark plasma sintering (SPS) at 1850^oC and varying pressure of 100, 255 and 363MPa. The effect of pressure on the densification and grain size is evaluated. The role of nano-sized B4C as sintering aid and grain growth inhibitor is studied by means of XRD, SEM and high resolution TEM. Fully dense TaC samples were produced at a pressure of 255MPa and higher at 1850^oC. The increasing pressure also resulted in an increase in TaC grain size. Addition of B4C leads to an increase in the density of 100MPa sample from 89% to 97%. B4C nano-powder resists grain growth even at high pressure of 363MPa. The formation of TaB2/Carbon at TaC grain boundaries helps in pinning the grain boundary and inhibiting grain growth. The effect of B4C addition on...
Several observational studies suggest that solar wind dynamic pressure fluctuations can drive magnetospheric ultra-low frequency (ULF) waves on the dayside. To investigate this causal relationship, we present results from Lyon-Fedder-Mobarry (LFM) global, three-dimensional magnetohydrodynamic (MHD) simulations of the solar wind-magnetosphere interaction. These simulations are driven with synthetic solar wind input conditions, where idealized ULF dynamic pressure fluctuations are embedded in the upstream solar wind. In three of the simulations, a monochromatic, sinusoidal ULF oscillation is introduced into the solar wind dynamic pressure time series. In the fourth simulation, a continuum of ULF fluctuations over the 0-50 mHz frequency band is introduced into the solar wind dynamic pressure time series. In this numerical experiment, the idealized solar wind input conditions allow us to study only the ...
In the atmospheric pressure coal combustion area, the Internally Circulating Fluidized Bed Boiler (ICFB) had already been proven to possess superior performance features in terms of the ease with which load conditions can be controlled and because of its low pollution level. Based on the particular merits of the ICFB furnace and the application of this technology to pressurized fluidized bed boiler technology, it was possible to achieve a pressurized fluidized bed boiler with superior ease of operation, reliability and low-pollution characteristics. From fiscal 1992, the authors have conducted extensive research work, including cold model tests and computer simulations to investigate the possibility of applying ICFB technology to the pressurized fluidized bed boiler technology in an attempt to develop the Pressurized Internally Circulating Fluidized Bed Boiler (PICFB). Based on the ...
In an existent emergency reactor core cooling device, if a ruptures should occure in a pipeline of a gravitational dropping type reactor core cooling system pool (GDCS) due to some or other causes, a portion of GDCS pool water was flown out of the ruptured port and could not be used for reactor core cooling. Then, a difference pressure detector is disposed to a GDCS pipeline at the inlet of a reactor pressure vessel. When it is judged by the detector, that coolants flow to the outside of the injection pipeline, an injection value disposed to the GDCS pipeline is closed by the difference pressure signal. Even if a rupture should occur on the side of the pressure vessel at downstream to the check value of the GDCS pipeline, since backflow is caused at the pressure container inlet of the GDCS pipeline with the rupture port, the rupture is detected by the difference ...
The effect of atmospheric pressure on tracking resistance of organic insulating materials were investigated in the range of 500 to 1007 hPa. The tracking resistance for Polycarbonate (PC), Modified Polyphenylene Oxide (M-PPO) and Paper Base Phenolic Resin Laminate (PL) increase with the decrease in atmospheric pressure. The scintillating discharges on these samples surface lead to the ignition. The tracking failure on these results from the ignition on the surface. For Polybutylene Terephthalate (PBT) and Polyethylene Terephthalate (PET), the tracking resistance decrease with the decrease in atmospheric pressure. The discharges observed on the these surface are the glow-like. The discharge area spreads on the surface between the electrodes at the lower pressure. The failure on this group results from the carbonization by the discharges on the surface. However, the tracking resistance for Unsaturated ...
This study investigated the effectiveness of dealing with biological waste by composting. In particular, it examined the feasibility of recovering excess thermal energy produced in the process of composting biological waste in terms of mass and energy transport parameters required in the aerated compost bed. An experiment was performed in which a 100 dm{sup 3} adiabatic, leak-tight reactor equipped with a controlled aeration system was constructed to study the temperature and pressure distribution in the bed. Sensors were used to determine the amount and humidity of emitted gases under variable external physical conditions. The perforated bottom of the reactor allowed for bed aeration. As such, the humidity and heat were transported upwards, forced by the air pumped in and by natural convection. In terms of pressure distribution inside the composted and aerated bed, the study results showed that there were considerable differences in ...
The development of KNGR (Korean Next Generation Reactor) is now in progress. KAERI is developing KNGR which is a advanced active PWR (pressurized water reactor) and 1350 MW electric capacities and is by based on UCN(Ulchin) 3 and 4 nuclear power plant which is a Korean standard PWR. In this report, the PZR (pressurizer) and Related System Design Features for KNGR which include PZR volume, PPCS (pressurizer safety valve)were analyzed. First, the Design Parameters between KNGR compared to UCH 3 and 4 were compared, and second, advanced design features of KNGR compared to UCN 3 and 4 were analyzed. After the present analysis, it has been concluded that the safety margins for the PZR level and pressure of KNGR were more increased by the larger PZR volume than those of UCN 3 and 4, for PZR minimum water level at reactor/turbine trip and PZR maximum pressure at LOCV(loss of condenser ...
We report here a new approach to introduce the effect of chemisorption in the Monte-Carlo simulation procedure for studying the segregation behaviour in bimetallic nanoparticles at low pressures. A coordination-dependent pair interaction energy is constructed in terms of partial bond energies and the exchange energy where the partial bond energy can be empirically calculated from the experimental values of dimer energy, the pressure-dependent surface energy and the bulk cohesive energy of the constituent metals. The advantage of this procedure is the ability to estimate the pressure-dependent surface composition of the nanoparticles. The method has been applied to oxygen-adsorbed Pd-Ag systems; and it is found that while Ag segregate in clean particles, at higher oxygen pressures Pd atoms segregate to the surface. The present technique has been argued to be suitable for higher ...
In this paper we consider the adsorption of argon on the surface of graphitized thermal carbon black and in slit pores at temperatures ranging from subcritical to supercritical conditions by the method of grand canonical Monte Carlo simulation. Attention is paid to the variation of the adsorbed density when the temperature crosses the critical point. The behavior of the adsorbed density versus pressure (bulk density) shows interesting behavior at temperatures in the vicinity of and those above the critical point and also at extremely high pressures. Isotherms at temperatures greater than the critical temperature exhibit a clear maximum, and near the critical temperature this maximum is a very sharp spike. Under the supercritical conditions and very high pressure the excess of adsorbed density decreases towards zero value for a graphite surface, while for slit pores negative excess density is possible at extremely high ...
The objective of this research was to determine improved thermal, epithermal, and fast fluxes and several responses at mechanical test surveillance location keys 2, 4, 5, and 7 of the pressure vessel of the Oak Ridge National Laboratory High Flux Isotope Reactor (HFIR) for the beginning of the fuel cycle. The purpose of the research was to provide essential flux data in support of radiation embrittlement studies of the pressure vessel shell and beam tubes at some of the important locations.
This paper reports on the electron current to a Langmuir probe in a moving high-pressure plasma. The plasma is an atmospheric-pressure propane flame, and the probe's speed relative to the plasma is varied from 10 to 30 ms"-"1. The current is linearly dependent on the speed and appears to be comprised of two components - one driven by diffusion and the other by convection. A model is devised which can be used to measure the electron density. By comparing the density computed from this model to that measured from the ion current, it has been possible to measure the electron mobility in the flame gases. The value obtained here is in good agreement with theoretical calculations found in the literature.
A high pressure waterjet has been used to study the surface roughening of superalloys as preparation for thermal spraying. Designed experiments for Mar-M 509 and Rene 80 were carried out for the effects of jet pressure and mass of water delivered per unit area. Comparisons were made of several superalloys in terms of erosion, surface roughness and topology. The mechanism of jet erosion of Rene 80 was studied in relation to its metallurgical microstructure. An MCrAlY coating by shrouded plasma spray was made over a waterjet prepared surface with excellent bonding and having an ideally clean interface.
Sigma 1) examines ways to reduce the number of breakdowns of pressure-regulating stations and to minimize the energy consumed in warming the gas, 2) determines the optimal gas temperatures upstream from the pressure reduction, and 3) shows the dependence of energy consumption upon the water dewpoint. The method of calculating the optimal input temperature relies on Mollier's diagram. Tables and nomographs for natural gas and water dewpoint at 19/sup 0/F and 580 psi (-7/sup 0/C and 4 MPa) are useful in achieving the desired gas temperatures. Heating the regulators' control valves is important.
Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition-rate measurements using molecular beam scattering and a very low-pressure cold-wall reactor. The RSCs have nonlinear Arrhenius temperature dependencies and decrease with increasing flux at low (710 /sup 0/C) temperatures. Several simple models are proposed to explain these observations. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction and low-pressure chemical vapor deposition-rate measurements.
This book presents the basic ideas of the physics of non-gravitational perturbations and the mathematics required to compute their orbital effects. It conveys the relevance of the different problems that must be solved to achieve a given level of accuracy in orbit determination and in recovery of geophysically significant parameters. Selected Contents are: Orders of Magnitude of the Perturbing Forces, Tides and Apparent Forces, Tools from Celestial Mechanics, Solar Radiation Pressure-Direct Effects: Satellite-Solar Radiation Interaction, Long-Term Effects on Semi-Major Axis, Radiation Pressure-Indirect Effects: Earth-Reflected Radiation Pressure, Anisotropic Thermal Emission, Drag: Orbital Perturbations by a Drag-Like Force, and Charged Particle Drag.
Measurements of the expansion rate of pure-electron plasmas have been performed on the Electron Diffusion Gauge (EDG) device at background helium gas pressures in the 5 x 10(superscript -8) Torr to 1 x 10(superscript -5) Torr range, where plasma expansion due to electron-neutral collisions dominates over plasma expansion due to trap asymmetries. It is found that the expansion rate, defined as the time rate of change of the particles' mean-square radius, scales approximately linearly with pressure and inversely as the square of the magnetic field strength in this regime, in agreement with classical predictions.
The study is concerned with the combined effect of high pressure and shear strain on the properties of the A-15 intermetallics Nb3Sn and Nb3Al0.75Ge0.25. The properties discussed are the superconducting transition temperature, the width and intensity of the X-ray diffraction lines, and the width and shape of the Mossbauer absorption lines. It is shown that the combined effect of high pressure and shear strain leads to an intense generation of defects in polycrystalline specimens; the size of the ordered regions does not exceed 300 A even under the least severe conditions. 5 references.
The outward radial expansion of a free liquid annulus is a common problem of both earlier and current ICF blanket design. Whether the annulus fractures or not depends on the internal pressure and surface stability. In this paper a model based on incompressible cylindrically symmetric flow is used to get a theoretical solution similar to that of the Rayleigh's solution for bubble dynamics. The pressure inside the annulus is found positive all time but the peak is lowering during the expansion. Besides, both surfaces are Taylor stable during such motion. Thus, it is concluded that an annulus in outward radial motion will not cavitate or breakup.
The aim of this review is to evaluate the role of inflammatory spine disease in patients with chronic back pain. The contribution of imaging modalities for the diagnostic evaluation of back pain is discussed. A systematic literature search based on the classification of seronegative spondyloarthropathies and rheumatoid arthritis was performed. The results of this search and the experiences in a large collective of rheumatological patients are analyzed. The prevalence of rheumatoid arthritis (1-2%) is comparable to that of spondyloarthropathies (1.9%). The etiology of these entities is not fully elucidated. Magnetic resonance imaging is increasingly used for early detection and surveillance of therapy with TNF-{alpha} antagonists. Bone marrow edema, which is only detectable with MRI, represents an early sign of inflammation. Therapy with TNF-{alpha} antagonists is based on clinical and laboratory criteria, and signs of inflammation in MRI. MRI ...
Engine flow simulation was provided by four separately mounted air ejectors connected to a high-pressure air supply. The engine nacelle center lines were ...
On all steam turbines operating with condensation the air leakage penetrating from the part of the plant which is under vacuum must be eliminated, in order to maintain the vacuum created by physical conditions. In order to attain effective air bleed-off, the water-steam-air mixture is conveyed via the super-cooling bundles in the condenser. In this way the steam partial pressure decreases and the air partial pressure increases at a constant condenser pressure. In this procedure the mixture is supercooled by about 4"0C compared with the saturate steam temperature appertaining to the condenser pressure. The values of volume of air leakage are the result of a year's experience on existing plant. (orig.).
... necessary to allow for the effata nr the finits size of the oressure tranaducer on both the root mean square and power spectral density measurements ...
Purpose - The purpose of this paper is to investigate the factors that affect the adoption of cloud computing by firms belonging to the high-tech industry. The eight factors examined in this study are relative advantage, complexity, compatibility, top management support, firm size, technology readiness, competitive pressure, and trading partner pressure. Design/methodology/approach - A questionnaire-based survey was used to collect data from 111 firms belonging to the high-tech industry in Taiwan. Relevant hypotheses were derived and tested by logistic regression analysis. Findings - The findings revealed that relative advantage, top management support, firm size, competitive pressure, and trading partner pressure characteristics have a significant effect on the adoption of cloud computing...
High-pressure, lean, premixed methane/air flames are investigated experimentally to determine turbulent flame speeds (s{sub T}). The results are based on the statistical analysis of single-shot OH-PLIF images. The influences of pressure (p = 5 - 14.4 bars) and equivalence ratio ( {phi} 0.43 - 0.56) on the turbulent flame speed are discussed. The analysis reveals that s{sub T} is independent of pressure and it depends strongly on equivalence ratio. The turbulent flame speed at {phi} = 0.56 is about 3 times higher than at {phi} = 0.43 because of the higher integral reaction rate caused by the higher fuel concentration and therefore higher adiabatic flame temperature. (author)
We report measurements of the electrical resistivity of the amorphous alloys Fe"4"0Ni"4"0P"1"4B"6 (Metglas 2826), Fe"3"2Ni"3"6Cr"1"4Pr"1"2B"6 (Metglas 2826A) Fe"8"0B"2"0 (Metgals 2605) and Fe"7"5B"2"5 as a function of pressure and temperature. The pressure is varied between 0 and 12 GPa, the temperature between 1.2 and 380 K. At low temperatures the pressure dependence yields additional information on the scattering mechanism. (orig.).
In a shipping terminal, the pipeline in the pier usually has a diameter smaller than the main pipeline diameter. This diameter reduction amplifies the effects caused by hydraulic transients. It was noticed during simulations that check valves placed in the pier may introduce some error in the maximum pressure when it was modeled in a conventional fashion. The dynamic check valve model had been added to a commercial pipeline simulation software and the results was compared with a similar model using the method of characteristics. Considering a real state shipping terminal case, it was proved even a pipeline that works with low pressure and smooth elevation profile needs a detailed valve modeling to prevent the calculation of unreal pressure values in the region with diameter reduction. (author)
The magnetic ordering temperature of some rare-earth-based heavy-fermion compounds is strongly pressure dependent and can be completely suppressed at a critical pressure, p{sub c}, making way for novel correlated electron states close to this quantum critical point. We have studied the clean heavy-fermion antiferromagnets CePd{sub 2}Si{sub 2} and CeIn{sub 3} in a series of resistivity measurements at high pressures up to 3.2 GPa and down to temperatures in the mK region. In both materials, superconductivity appears in a small window of a few tenths of a GPa on either side of p{sub c}. We present detailed measurements of the superconducting and magnetic temperature-pressure phase diagram, which indicate that superconductivity in these materials is enhanced, rather than suppressed, by the closeness to magnetic order. (author)
The magnetic ordering temperature of some rare-earth-based heavy-fermion compounds is strongly pressure dependent and can be completely suppressed at a critical pressure, p_c, making way for novel correlated electron states close to this quantum critical point. We have studied the clean heavy-fermion antiferromagnets CePd_2Si_2 and CeIn_3 in a series of resistivity measurements at high pressures up to 3.2 GPa and down to temperatures in the mK region. In both materials, superconductivity appears in a small window of a few tenths of a GPa on either side of p_c. We present detailed measurements of the superconducting and magnetic temperature-pressure phase diagram, which indicate that superconductivity in these materials is enhanced, rather than suppressed, by the closeness to magnetic order. (author)
The Nobel lecture of Chandrasekhar is printed in which he describes the basic processes that determine the life history of a star with particular emphasis on the roles of stellar mass and radiation pressure. (AIP)
Cardiovascular effects of positive end-expiratory pressure (PEEP) at 20 cmH2O were examined in six mongrel dogs (11.3-15.0 kg). The dogs were anesthetized through a combination of intramuscular Innovar and gaseous anesthesia (60% N2O-40% O2). For volume measurements, radiodense tantalum screws were placed on the endocardial surface of the left and right ventricle. Esophageal and left and right ventricular pressures were measured. With the use of this preparation, the effects of positive end-expiratory pressure (PEEP = 20 cmH2O) on cardiovascular function were examined. PEEP caused right ventricular transmural pressures to decrease, 3.4 +/- 1.0 to 2.0 +/- 1.0 mmHg end-diastolic (P less than 0.05) and 29.2 +/- 2.2 to 27.9 + 2.2 mmHg peak systolic; left ventricular transmural pressures decreased, 5.9 +/- 1.6 to 1.2 +/- 1.4 mmHg end-diastolic (P less than 0.05) and 117.2 +/- 8.0 to 76.2 ...
This renewal request for DOE grant DE-FG02-86ER45238, is dedicated to providing a complete thermodynamic profile of solids fluids, and fluid mixtures, over a wide range of temperatures and pressures. We are partially motivated by technological interest in detonation, combustion, superhard high pressure materials, and high temperature superconductors, which are important components of interest of various DOE laboratories. Our work on fluids and solids, composed of simple molecules, involves the determination of structures, phase transitions, pressure-volume relations, phonon, vibron, and libron modes of excitation, sound velocities, specific heats, thermal expansion, virial coefficients, sublimation energies, and orientational translational, and magnetic correlations. We hope that the study of these systems under extreme thermodynamic conditions will lead to exotic new materials of value, as well as enhanced fundamental ...
We demonstrate a novel cross-sectional deformation, called the radial corrugation, of multi-walled carbon nanotubes (MWNTs) under hydrostatic pressure. Theoretical analyses based on the continuum elastic approximation have revealed that MWNTs consisting of more than ten concentric walls undergo elastic deformations at critical pressure Formula Not Shown , above which the circular shape of the cross-section becomes radially corrugated. Various corrugation modes have been observed by tuning the innermost tube diameter and the number of constituent walls, which is a direct consequence of the core-shell structure of MWNTs. Cross-sectional views of MWNT under high hydrostatic pressure: elliptic deformation with the mode index n = 2 (left), and radial corrugations with n = 5 (center), and n = 6 ...
Red laser diodes emitting at 636 nm and 645 nm are studied as a function of pressure up to 20 kbar and temperature from 300 K down to 80 K. The 636 nm samples reveal anomalous L-I-V dependence at low temperatures and at high pressures. The 645 nm samples do not show these anomalies and can be tuned by pressure and temperature down to 575 nm, i.e., in the 70 nm range with powers above 200 mW and low threshold currents. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
A high pressure piezometer is described with which pVT-measurements on solutions of gases in liquids like oils can be performed at pressures and temperatures up to 2000 bar and 440 K, respectively. The present investigations deal mainly with the system squalaneCO/sub 2/ at different mole fractions, but also with squalaneN/sub 2/. The high accuracy of the measurements reveals a pronounced structure of the pV-curves in dependence on temperature and mole fraction. At larger mole fractions is the unequivocal assignment of the phases ambiguous, and the representation of the experimental data in terms of an equation of state not possible for the whole pressure and temperature range. However, for solutions with lower mole fractions could be determined the saturation pressures and the isothermal compressibility in the unsaturated region. Furthermore, the molar excess volumes of the mixture have been calculated ...
This site explains how temperature, pressure, and salinity work together to determine the density of ocean water. The three density layers of the ocean are described by means of text description and a graphic illustration.
Nomographs are presented that estimate the evaporation loss from external floating-roof tanks using tank diameter, type of seal, product vapor pressure, and wind velocity.
(e.g. enclosed cooktop with built in emissions capture and treatment) . " Test hardware in laboratory, reduced pressure and analog habitat. " Objective 1. ...
This study examined whether elevated intravascular pressure stimulates asynchronous Ca2+ waves in cerebral arterial smooth muscle cells and if their generation contributes to myogenic tone development. The endothelium was removed from rat cerebral arteries, which were then mounted in an arteriograph, pressurized (20 100 mmHg) and examined under a variety of experimental conditions. Diameter and membrane potential (VM) were monitored using conventional techniques; Ca2+ wave generation and myosin light chain (MLC20)/MYPT1 (myosin phosphatase targeting subunit) phosphorylation were assessed by confocal microscopy and Western blot analysis, respectively. Elevating intravascular pressure increased the proportion of smooth muscle cells firing asynchronous Ca2+ waves as well as event frequency. C...
This paper describes the methods and systems as utilized in an integrated experimental thermohydraulic/mechanics analysis test program on waterhammer pressure pulses within a revised feedwater sparger of a Loviisa generation VVER-440-type reactor. This program was carried out in two stages: (1) measurements with a strictly limited set of operating parameters at Loviisa NPP, and (2) measurements with the full set of operating parameters on a test article simulating the revised feedwater sparger. The experiments at Loviisa NPS served as an invaluable source of information on the nature of waterhammer pressure pulses and structural responses. These tests thus helped to set the objectives and formulate the concept for series of tests on a test article to study the water hammer phenomena. The heavily instrumented full size test article of a steam generator feedwater sparger was placed within a pressure vessel simulating the ...
Abstract Hybrid power plants consisting of a solid oxide fuel cell (SOFC) and a gas turbine show high electrical efficiencies, however require pressurisation of the SOFC to several bar. This paper presents a theoretical investigation of the pressure influence on SOFC performance and durability. A two-dimensional elementary kinetic model is used to predict the performance of a single cell in the pressure range of 1-20-bar. The influence of pressure on thermodynamics, reaction kinetics, porous electrode diffusion, channel transport and efficiency is assessed. It was found that polarisation resistance decreases with increasing pressure due to increased diffusion through porous electrodes and a higher electrode surface coverage with reactant species. Furthermore, open-circuit voltage increases...
A method is described for immobilizing or solidifying waste material, which includes blending the waste material with powdered metal and subjecting the mixture of waste material and powdered metal to high pressure. (author).
... In: Separated Flows, AGARD CP No. ... on thin wings in two-dimensional incompressible flow. ... fields in the region of separating and reattaching flows. ...
One of the more extensive uses of directional drilling anywhere in the world has been in the development of the East Wilmington Oil Field in Long Beach, California. The Measurement-While-Drilling (MWD) directional system has been tested on several wells and proven to provide the required accuracy, along with many advantages over past methods, used in the field development. Accurate transmission by MWD of bottom-hole measurements to the surface is provided by mud pressure pulses generated in the drill pipe downhole and detected by a pressure transducer includes the means for detecting, recording and processing these pressure pulses, to translate the information from the pressure pulses to rig floor displays usable by the drilling crew. 2 refs.
The Sulige gas field and the Yulin gas field are located in the north of the Ordos Basin. Reservoir pressure in the Sulige area is subnormal, whereas reservoirs in the Yulin area have normal hydrostatic pressure. This paper provides an explanation of this difference. The characteristics of reservoir sediment and formation water chemistry in the gas reservoirs of these two areas were analyzed. The results showed that both reservoirs have good sealing ability. Data of numerical simulation showed that tectonic uplift resulted in a great reduction in formation pressure in the northern Ordos Basin during the late Cretaceous period, and the decrease was greater in the Yulin gas field than in the Sulige gas field. However, because the total hydrocarbon-generating intensity of the Sulige area (<24...
The present paper deals with the experimental determination of pressure drop across a four-cusped vertical channel. This geometry represents, ideally, the blockage condition in a typical pressurized water reactor with core degraded by accident. Experiments were performed for both single and two-phase flow. Water was utilized for the single-phase measurements whilst simultaneous flow of air and water simulated the steam-water flow. Observation of the prevailing two-phase flow regime was carried out, so that its mechanism could be fully understood. The averaged void fraction was also measured, by the gamma-ray attenuation technique. A wide range of water and air mass flow rates was covered, so that all flow conditions, possible to exist in a reactor with LOCA, could be investigated. New correlations for pressure drop are proposed. (Author).
The intermediate valent behaviour of YbPd_2Si_2 has been studied under pressure in the temperature range from 1.2 K to 90 K by using the 84 keV Moessbauer transition in "1"7"0Yb. At 54 kbar and 4.2 K we obtain an increase of the electric field gradient (EFG) by a factor of #approx =# 3. In addition, the EFG varies strongly with temperature, in contrast to the behaviour at ambient pressure. At 1.2 K a change of the hyperfine pattern is observed indicating a magnetic character of the Yb ion. These results provide evidence of a pressure induced change of the valence state close to 3+. (orig.).
As usual a shipping terminal contains a header and its diameter is smaller than the main pipeline diameter. This diameter reduction amplifies the effects caused by hydraulic transients. It was noticed during simulations that check valves without dynamic modeling may introduce some error in the maximum pressure results without a dynamic model approach. The current paper uses commercial pipeline simulation software to model the dynamic behavior of the check valves. It was studied the header diameter influence and how the check valve model type may change the maximum pressure in the pipeline. It was proved that even a pipeline that works with low pressure and small elevation drop needs a detailed valve modeling to prevent the calculation of unreal pressure values in the region with diameter reduction. (author)
Abstract The recent paper by Heyer et al. indicates that observations of size, linewidth and column density of interstellar clouds do not agree with simple virial equilibrium (SVE) as a balance between gravitational and kinetic energies in the sense that the clouds either have too much kinetic energy or too little mass to be bound. This may be explained by violation of SVE as suggested by Dobbs et al., by observational underestimation of the masses as suggested by Heyer et al. or by an external pressure acting as an additional confining force as suggested earlier by Heyer et al. The data of Heyer et al. cannot be explained with a single value for the external pressure, but if different clouds in the sample have different external pressures in the range of Pe/k= 104-107 cm-3-K, then most of...
flow over the suction surface of a modern low- ..... the flow because of its proximity to the separation point ..... Pressure Turbines, AGARD Lecture Series 167, ...
In equipment industries, the equipments handling industrial water and pure water are numerous. In power generation including nuclear power generation, water serves as a working medium. Review is made on the experiences in the corrosion of iron and nickel base alloys in high temperature, high pressure water and the results of researches derived from them. Under high temperature and high pressure, carbon steel, low alloy steel, stainless steel and high nickel alloy cause corrosion even in pure water. But in the case of serious corrosion, chlorine, oxygen, alkali and others in water take part. The following matters are described: corrosion by steam; stress corrosion cracking in pure water; corrosion by impurities in high temperature, high pressure pure water, i.e. chlorine ions, dissolved oxygen, and alkali; corrosion under radiation. (J.P.N.).
Integrated Leakage Rate Test (ILRT) of containment system plays a very important role in safety of a Nuclear Power Plant. Containment system constitutes the last physical barrier to release of radioactivity from the core and is called upon to mitigate the consequences of not only accidents within the design basis, but also some of the highly unlikely severe accidents. Hence, leak tightness of containment becomes uttermost priority for the safety of plant personnel and public. The containment and associated ESFs are tested before the first criticality and there after periodically during service. The pre-operational integrated leakage rate is carried out at LOCA based design pressure, at periodic test pressure and at some intermediate pressure points to assess the leakage characteristics. This paper summarizes the various requirements and activities relevant to the ILRT of the Indian Pressurized Heavy ...
Biodegradable helicoidal stent prototypes made up of layers of poly-L-lactic acid (PLLA) and poly(L-lactic-co-glycolic acid) (PLGA) polymers were fabricated by temperature conditioning the stents at different stages of fabrication. The process incorporated elastic memory, or self-expandability in the stent, which is desirable to minimize stent recoil. The collapse pressures of such stents were studied, with and without in vitro degradation. The effects of thickness and the composition of each layer on the collapse pressure were modeled using the simple series model. Results of the in vitro studies for over 3 months showed that collapse pressure of the stents depended mainly on the degradation and other side-effects brought about by the degradation of different polymer compositions. General...
... and Cardiac Function test (including optional measurements of central venous pressure (CVP), via a peripherally inserted central catheter, and cardiac output ...
Experience gained with a wide variety of missile injuries of the brain is presented. Clinical signs and intracranial pressure (ICP) studied in the early post-injury period have been correlated with...Full Text Available
Hypertension affects most hemodialysis patients and is often poorly controlled. Adequate control of blood pressure is difficult with conventional hemodialysis alone but is important to improve...Full Text Available
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 ...
This study was carried out to evaluate the microbial contamination on pork carcasses after they had fallen on the floor in the cooler and also to evaluate the effectiveness of trimming and hot, high-pressure...Full Text Available
This paper discusses the economics of legumes irradiation such as Chickpea,Lupin,Kidny Bean and broad and the effect of various parameters on unit processing costs. It provides a model for calculating specific unit processing costs by correlating known capital costs with annual operation cost an annual throughputs. We analysed the cost-benefit of the proposed grain irradiation facility. We took into account the cost of the capital investment, operation and other additional parameters and then estimated the unit processing cost. The investment criteria utilized for commercial evaluation were internal rate of return (I.I.R), pay back period (P.B.P), and average rate of return (A.R.R). The irradiation cost and the additional income are also discussed. The results of this analysis showed that the installation of an irradiation unit for legumes processing in Egypt would be economically feasible.
We present our initial experience with a new biodegradable (BD) esophageal stent in two patients, one for a therapy-resistant benign esophageal stricture, and the other as a temporary measure during curative radiotherapy for oesophageal carcinoma. The BD stents need to be loaded into a conventional pull-back delivery system but are then placed in a standard fashion. Pre-dilatation should be avoided to reduce the risk of migration, however if migration occurs the stents can be left to dissolve in the stomach. The stents are radiolucent but easily identified on CT with minimal artefact and thus might even aid with radiotherapy planning. BD stents offer an exciting new strategy for therapy-resistant benign strictures as well as a supportive measure for oesophageal cancer undergoing non-surgical treatment. (orig.)
Abstract The past and future dynamical evolution of all 64 long-period comets having 1/aori 3.0-au and discovered after 1970 is studied. For this sample of Oort-spike comets we have obtained a new, homogeneous set of osculating orbits, including 15 orbits with detected non-gravitational parameters. The non-gravitational effects for 11 comets have been determined for the first time. This means that more than 50 per cent of all comets with perihelion distances between 3 and 4-au and discovered after 1970 show detectable deviations from purely gravitational motion. Each comet was then replaced with a swarm of 5001 virtual comets representing the observations well. These swarms were propagated numerically back and forth up to a heliocentric distance of 250-au, constitutin...
Seismic records, combined with dredged samples and a core, indicate that the Spratly Islands of the Dangerous Ground Province are constructed of presently active carbonate build-ups, known to extend back continuously at least to the Pleistocene and presumed to have initiated in the Miocene, most likely upon the crests of sea-floor cuestas that trend north-east-south-west parallel to the sea-floor spreading magnetic anomalies of the contiguous abyssal plain of the southern part of the South China Sea. The cuestas range from spectacular to subdued, constructed of Triassic and Cretaceous strata and no older rocks have been identified from dredges. The cuesta axes plunge towards the south-west away from the islands, suggesting that the reefs began colonising their more elevated parts, but the ...
Infinite loop space theory, both additive and multiplicative, arose largely from two basic motivations. One was to solve calculational questions in geometric topology. The other was to better understand algebraic K-theory. The Adams conjecture is intrinsic to the first motivation, and Quillen's proof of that led directly to his original, calculationally accessible, definition of algebraic K-theory. In turn, the infinite loop understanding of algebraic K-theory feeds back into the calculational questions in geometric topology. For example, use of infinite loop space theory leads to a method for determining the characteristic classes for topological bundles (at odd primes) in terms of the cohomology of finite groups. We explain just a little about how all that works, focusing on the central role played by E infinity ring spaces.
A wavelet transformation is performed over each of the spatial coordinates of the scalar wave equation. This transformed equation is solved directly with a finite-difference scheme for both homogeneous and smooth inhomogeneous media. Wavefield extrapolation is performed completely in the spatial wavelet domain without transforming back into the space domain at each time step. The wavelet coefficients are extrapolated, rather than the wavefield itself. The numerical solution of the scalar wave equation in the spatial wavelet domain is closely related to the finite-difference method because of the compact support of the wavelet bases. Poststack reverse-time migration is implemented as an application. The resolution spaces of the wavelet transform provide a natural framework for multigrid analysis. Migrated images are constructed from various resolution spaces.
Summary Objective Community-based information on the delivery and use of health interventions is important to monitor the effectiveness of the Roll Back Malaria programme. However, community surveys to determine coverage for insecticide-treated bed nets are time-consuming and costly. We wanted to assess whether schoolchildren's reports of household ownership of a bed net and coverage among high-risk groups monitored by schoolteachers through a questionnaire could be used as a proxy of household ownership of bed net and coverage at community level, for routine monitoring of malaria control programmes. Method 3602 schoolchildren in 39 randomly selected schools and 2798 heads of households in 39 villages were interviewed about their use of either insecticide-treated or untreated bed nets. Res...
Elastically deforming thin glass (thickness = 0.13 to 0.80 mm) provides an alternate method of forming a curved glass reflector which can eliminate some of the disadvantages of thicker glass. A concept is described where silvered thin glass is bonded to a steel backing to form a laminate with a reflectance greater than 93%. Subsequent bending of the flat reflector laminate to a concentrating profile produces compressive stresses throughout the glass if the laminate is properly designed. These compressive stresses enhance fracture resistance and the lamination provides protection for the silver. The design of the laminate is outlined for 0.25 and 0.51 mm thickness glass and fabrication procedures are discussed. Thermal/humidity cycling, hail impact, bond strength measurements and reflectance results are presented which demonstrate the performance capabilities of this reflector laminate concept.
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.
We have fabricated nanometer-spaced electrodes on electron-transparent silicon nitride membranes. A thin Cr/Au layer is evaporated on the backside of the membrane which serves as a gate electrode. Using these devices, we have performed three-terminal electron transport measurements on gold nano-particles at liquid helium temperature. Coulomb Blockade features have been observed and the capacitance to the gate has been extracted. After transport measurements, the Cr/Au back gate is removed and the devices are inspected with a transmission-electron microscope (TEM). TEM inspection reveals the presence of a few nano-particles in the nanogap, which is in agreement with the transport measurements. In addition, the nano-particle size as observed by TEM coincides with the one estimated from the gate capacitance value.
The advent, in the near future, of compact X-ray sources like Thomson Back-Scattering (TBS) will allow the clinical application of advanced X-ray imaging techniques, such as phase contrast, with higher sensitivity and lower impact in terms of dose delivery. In this work, we theoretically investigated the possibility of using such sources for phase contrast imaging of micro-calcifications included in a breast tissue. In our study we analyzed the phase and amplitude distribution of the TBS source and we showed that this source can be used for phase contrast imaging since the source coherence at the sample position is sufficiently high for achieving good contrast and micrometer spatial resolution. Indeed the spatial coherence of a TBS source is closer to that of a synchrotron radiation source, and much better than that of a laboratory source. Moreover, we showed the advantages of phase imaging with respect to standard absorption imaging, in the specific case of ...
We used a 13-year time series of abundance estimates of breeding Northern Saw-whet Owls (Aegolius acadicus), and of small mammals from central Ontario, Canada, to assess the numerical response of the owls to small-mammal prey species. We found that the finite rate of increase of breeding owls was directly related to estimates of red-backed vole (Myodes gapperi) abundance. Thus, it appeared that the owls were nomadic, and made decisions about where to breed based on vole supply. The owls showed a much weaker response to deer mouse (Peromyscus maniculatus) abundance. Across all years, 55% of variation in owl rate of increase could be uniquely attributed to vole abundance, whereas only 3% could be attributed to mouse abundance. Consistent with the model of nomadism, there was only a weak rela...
We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These moments back-react on the trajectories of the expectation values of the state and hence alter the energy density at the bounce. This analysis is performed for isotropic loop quantum cosmology coupled to a scalar field with a small but non-zero constant potential, hence in a regime in which the kinetic energy of matter dominates. Analytic restrictions on the existence of dynamical coherent states and the meaning of semi-classicality within these systems are discussed. A numerical investigation of the trajectories of states that remain semi-classical across the bounce demonstrates that, at least for such states, the bounce persists and that its properties are similar to the standard case, in which the moments of the states are ...
The new oil price environment is sending industry engineers back to the drawing board. The search is on for cost effective and perhaps unconventional deepwater production systems. One candidate for Gulf of Mexico deepwater tracts is a tanker-based floating production, storage, and offloading (FPSO) system. Substantial experience with tanker-based FPSO systems has proven them to be cost effective when the field is remote from existing production facilities and pipelines. A tanker-based system offers the unique feature of integrating production, storage, and offloading capabilities into a single unit. Such systems can be installed in 12 to 15 months and can even be leased, significantly improving an operator's cash flow.
In the last few years the management of nuclear power plants as well as the supervising administration of the nuclear industry in Germany has focused more on emergency preparedness. The skills have been improved, but there are also improvements under way, yet. The study gives an overview about the status of emergency preparedness in German power plants, about the legal framework for emergency preparedness and about the elements of an effective emergency preparedness planning. However, it does not deal with technical accident management but with the organisational aspects of emergency planning. Also, the study gives a short outlook for future trends of development in the field of emergency preparedness in Germany. Major trends are the standardisation of organisational concepts, more training and more national and international feed back of know how on the topic. Yet, there is still some research work to be done, mainly to develop overall organisational standards and ...
This report describes the status of nuclear safety and radiation protection in the facilities of the AREVA group and gives information on radiation protection in the service operations, as observed through the inspection programs and analyses carried out by the General Inspectorate in 2007. Having been submitted to the group's Supervisory Board, this report is sent to the bodies representing the personnel. Content: 1 - A look back at 2007 by the AREVA General Inspector: Visible progress in 2007, Implementation of the Nuclear Safety Charter, Notable events; 2 - Status of nuclear safety and radiation protection in the nuclear facilities and service operations: Personnel radiation protection, Event tracking, Service operations, Criticality control, Radioactive waste and effluent management; 3 - Performance improvement actions; 4 - Description of the General Inspectorate; 5 - Glossary.
... The drop in pay, with mounting medical bills and a curve ball in their personal life, led Mr. Flake and his wife, Amy, to exhaust their savings. As they shifted spending to credit cards their debt mounted, and conversations about retirement ... In October 2008, they learned that a relative of hers with an 8-month-old son was going to prison. If the Flakes could not take the baby, he would be placed in foster care. The Flakes did some soul searching and decided to seek custody of ...) 1 2 Next Page »A version of this article appeared in print on March 24, 2011, on page F4 of the New York edition. Sign In to E-Mail Print Single Page Reprints Connect with The New York Times on Facebook. Get Free E-mail Alerts on These Topics Retirement Personal ...
The paper seeks to illuminate everyday work practices in the economic spaces of Malaysia's business process outsourcing (BPO) industry. It draws upon empirical evidence from call centre staff and promotes analytical sensitivity to the experience of labour and spatiotemporal relations within the offshore back offices of multinational corporations located in Cyberjaya, Malaysia. The analysis provides an empirical snapshot of how IT-facilitated work practices in the global information economy are embedded and socially reproduced in everyday settings. To this end, the paper engages anthropologically with BPO labour, and critiques -globalist- representations of economic and social transformation frequently articulated through an abstract, dehumanized space of networks and flows often seen to wa...
A simple method is presented for the separation of lead-203 from copper-backed thallium cyclotron targets. The procedure involves cation-exchange chromatography in hydrochloric acid and hydrochloric acid-acetone mixtures. Further purification involves anion-exchange chromatography in nitric acid-hydrobromic acid mixtures. A cation-exchange column containing 3.0 g of resin can handle as much as 15 g of thallium and 160 mg of copper. An anion-exchange column containing 3.0 g of resin can separate lead from up to 200 mg of thallium and 10 mg of copper. Separations are extremely sharp and less than 0.1 ..mu..g of thallium and less than 0.1 ..mu..g of copper remain in the lead-203 fraction.
A simple method is presented for the separation of lead-203 from copper-backed thallium cyclotron targets. The procedure involves cation-exchange chromatography in hydrochloric acid and hydrochloric acid-acetone mixtures. Further purification involves anion-exchange chromatography in nitric acid-hydrobromic acid mixtures. A cation-exchange column containing 3.0 g of resin can handle as much as 15 g of thallium and 160 mg of copper. An anion-exchange column containing 3.0 g of resin can separate lead from up to 200 mg of thallium and 10 mg of copper. Separations are extremely sharp and less than 0.1 #mu#g of thallium and less than 0.1 #mu#g of copper remain in the lead-203 fraction. (author).
A segmented focal plane detector for an Enge split-pole spectrograph has been developed for the study of breakup reactions at very low relative energies. It consists of a 61 cm long segmented position-sensitive parallel plate avalanche counter backed by a large Bragg curve detector. A segmented plastic scintillator is mounted behind the anode of the Bragg curve detector and is used for particle identification of low-ionizing particles. The dead space between the two sections of the focal plane detector is 2.5 mm. The intrinsic position resolution of the detector is 1 mm. The intrinsic energy resolution depends on the energy of the incident ion and can be as good as 0.55%. The nuclear charge and mass resolutions are 0.3 e and 0.3 u, respectively. (orig.).
A back-propagation neural network technique is used at JET to extract plasma parameters like ion temperature, rotation velocities or spectral line intensities from charge exchange (CX) spectra. It is shown that in the case of the C VI CX spectra, neural networks can give a good estimation (better than +-20% accuracy) for the main plasma parameters (Ti, V{sub rot}). Since the neural network approach involves no iterations or initial guesses the speed with which a spectrum is processed is so high (0.2 ms/spectrum) that real time analysis will be achieved in the near future. 4 refs., 8 figs.
This is a process for manufacturing a semi-rigid, folding solar generator manufactured from several coated solar cells (Cics), which has at least two folding parts connected together so as to turn by hinges, characterized by the following stages of the process: a) On the back of matrix subsections, in order to cover the connector, carbon fibre strips are glued on, which project over the upper or lower edge of each matrix subsection. b) The projecting ends of adjacent carbon fiber strips are connected with two carbon fibre strips. c) At least two matrix subsections are fixed in separately manufactured carbon fiber frames, and d) the carbon fiber frames, together with the matrix subsections are connected via hinges to a solar generator.
This is a process for producing calcium sulfate dihydrate during desulfurization of stack gases from power station boilers, where the stack gases are introduced into a washing tower and are treated with a washing water suspension containing lime in the washing tower, where oxygen in the form of air or of air enriched in oxygen is also blown into the washing tower, and where the washing water suspension drawn off from the washing tower is fed back to the washing tower at a temperature of 45 to 50/sup 0/C in the circuit and at least part of the flow goes via a thickener and where calcium sulfate dihydrate slurry is drawn off from the thickener.
The historical back ground of free electron laser (FEL) and the present status of development and utilization research of FEL facilities in the world are explained. Eight facilities such as Stanford Univ., UCSB, Duke Univ., Vanderbilt Univ., LANL AFEL (USA), FOM FELIX (Netherlands), N-lands LURE CLIO (France) and FELI (Japan) can be used. The principle of FEL generation process is that free electrons move in a zigzag direction to generate radio waves which interfere with each other to become monochromatic light and then free electron laser. The benefits of FEL, quality of electron beam, limit of wave length of FEL, problems and development of utilization technologies of FEL are explained. (S.Y.)
ERDMANN A.L., DE ANDRADE S.R., FERREIRA DE MELLO A.L., KLOCK P., DO NASCIMENTO K.C., SANTOS KOERICH M. & STEIN BACKES D. (2011) Practices for caring in nursing: Brazilian research groups. International Nursing Review58, 379-385 Background:- The present study considers the production of knowledge and the interactions in the environment of research and their relationships in the system of caring in nursing and health. Aim:- To elaborate a theoretical model of the organization of the practices used for caring, based on the experiences made by the research groups of administration and management in nursing, in Brazil. Methods:- The study is based on grounded theory. Twelve leaders of research groups, working as professors in public universities in the south and the south-east of Brazil, distri...
A new power system stabilizer (PSS) design method for single-machine infinite-bus systems is developed. This design method not only assigns the poles corresponding to the electro-mechanical oscillation modes in the system, but also located other system poles in suitable places in the s-plane. The design procedure is used first to translate a PSS design problem to an equivalent constant output feedback controller design problem for a single-input multi-output (SIMO) system. Then, a new algorithm developed in this paper is applied to design a constant output feedback controller to achieve the desired closed-loop system pole locations. Finally, the controller gains are transferred back to the parameters in the PSS. The extension of the method to multi-machine power systems is also illustrated. (Author).
This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained ...
This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained ...
The Pinellas Plant has been part of the Department of Energy`s (DOE) nuclear weapons complex since the plant opened in 1957. In March 1995, the DOE sold the Pinellas Plant to the Pinellas County Industry Council (PCIC). DOE has leased back a large portion of the plant site to facilitate transition to alternate use and safe shutdown. The current mission is to achieve a safe transition of the facility from defense production and prepare the site for alternative uses as a community resource for economic development. Toward that effort, the Pinellas Plant Environmental Baseline Report (EBR) discusses the current and past environmental conditions of the plant site. Information for the EBR is obtained from plant records. Historical process and chemical usage information for each area is reviewed during area characterizations.
A photoacoustic (PA) imaging system based on an ultrasonic Fresnel zone plate (FZP) transducer is developed for the purpose of imaging biological tissue. This FZP transducer has a two-zone negative zone plate piezoelectric material pattern, and an optical fibre is integrated with the transducer on the symmetric axis of the zone plates to deliver laser pulses to the sample. The focal characteristic of the FZP transducer is analysed by theoretical prediction and experimental measurement, and the measured results are in good agreement with the predicted results. The limited-field back-projection deconvolution algorithm combined with the coherence-factor weighting technique is used to reconstruct the optical absorption distribution. The experiments were performed with phantoms and the blood vessels of chicken embryo chorioallantoic membrane. The results demonstrate that PA imaging using the FZP transducer has the ability to image biological tissue and has potential ...
We have discovered a previously unidentified thermal explosion mode using the Los Alamos deflagration cylinder test (DFCT). The DFCT is a "pipe bomb"-style test similar to the detonation cylinder test (DTCT), which has been used for many years to calibrate detonation product equations of state. The shot is heated in an oven to a uniform test temperature. The pre-heated high explosive (HE) is triggered by a hot wire initiator on one end. The tube is back-illuminated by a bright light source, and its combustion-driven deformation and subsequent break-up are observed by a high-speed framing camera. Like the DTCT, the DFCT tube wall motion provides the primary diagnostic. A variety of reactive responses are possible, including quasi-steady deflagration and deflagration-to-detonation transition...
To determine the proportion of rheumatoid arthritis (RA) patients receiving preventive health care according to US Preventive Services Task Force recommendations compared with a community-based population sample, with emphasis on dyslipidemia testing, given the increased risk of cardiovascular disease (CVD) in RA patients. Patients with RA (ICD-9 code 714.0 at ?2 office visits with a rheumatologist) and a primary care physician (PCP) at the Geisinger Health System (GHS) were identified through electronic health records. The records were searched back from 3/31/08 for the length of time required to satisfy each outcome measure. Percentages were compared with population testing rates using the Pearson Chi-square test. Eight hundred and thirty-one RA patients were compared to 169,476 subjects...
Tata Electric Companies (TEC) are engaged in the generation of hydro and thermal energy. TEC, to minimise backing down of its thermal units in off peak hours and also to at least partially meet the growing deficit in the supply during peak hours is moving to install pumped storage plants (PSPs) utilising off-peak surplus energy for pumping the water from lower pond to the upper pond for subsequent utilisation for power generation during peak hours. In view of some of the infra structural facilities such as storage ponds, water conductor system, transmission lines, etc. being already available, at the existing hydro power stations owned by TEC, the pumped storage units are being proposed within the environs of existing hydro stations, i.e. a 150 MW pumped storage unit at Bhira and a 90 MW pumped storage unit at Bhivpuri. The projects are described and cost estimates is given. (author). 2 figs.
The problem in perturbation theory in general relativity is finding a natural gauge which simplifies the equations considerably. We solved the first and second order perturbation equations in the ''Lorentz gauge'' using the two-timing method. The equations were deduced from the equations of Einstein in the presence of a matter energy-momentum tensor of a perfect fluid with equation of state p = (#gamma#-1) rho. It is found that the 0--0 component of the first order equations together with the gauge conditions are consistent with the Bianchi type V model, without axial symmetry. It represents a ''ground state'' situation of the Bianchi type IX model (Mixmaster model.) The second order equations, describing the reaction back of the gravitational waves on the slowly varying background, give rise to rotation and will disturb the isotropization mechanism. The numerical solutions show all the features which are expected to appear. Moreover, it is found that the frequency ...
In vibration control field, magneto-rheological (MR) fluid dampers are semi-active control devices that have recently begun to receive more attention. This paper presents a nonlinear black-box model (BBM) and an inverse black-box model (IBBM) for the identification of a MR fluid damper and their application to design a novel force-sensorless control method for any damping system using that damper. The nonlinear model named 'black-box' is a simple direct modeling method which was designed based on fuzzy-neural technique. Characteristics of the damper in study are directly estimated through a fuzzy mapping system. In order to improve the model accuracy, neural network technique including back-propagation and gradient descent method were used to train the fuzzy parameters to minimize the mode...
Just below the Arctic Circle, about 200 kilometres off the Helgeland coastal region of Norway, lies the Skarv oil and gas field. Discovered in 1998, the greater Skarv development project now includes the Idun gas field. The Skarv development has begun to take shape, now roughly half-way to commencement, so Scandinavian Oil-Gas Magazine decided it was time to take a look at the project's progress thus far and what's left to do before production that's slated to begin in late summer, 2011. The Skarv Project include subsea wells connected to a floating production storage and offloading (FPSO) vessel to process oil and condensate and a gas export pipeline that ties back to the Aasgard Transport system. (AG)
...The RSPB: Great crested grebe A delightfully elegant waterbird with ornate head plumes which led to its being hunted for its feathers, almost leading to its extermination from the UK. E-mail to a friendE-newsletterContact us Home England Northern Ireland Scotland Wales About Overview Awards & recognition Contact us Facts and figures History How we are run Inspiring work Job vacancies Looking to the future Media centre Offices The RSPB view ...status: Green Listen Get Flash player Play sound 1 videoLatin name Podiceps cristatusFamily Grebes (Podicipedidae)Overview A delightfully elegant waterbird with ornate head plumes which led to its being hunted for its feathers, almost leading to its extermination from the UK. They dive to feed and also to escape, preferring this to flying. On land they are clumsy because their feet are placed so far back on their bodies. ...
Strain transient dip tests have been conducted on two commercial heats of Alloy 800 at 922 K. Tests were conducted on both a servo-controlled hydraulic machine and a specially designed dip test machine. Using measured maximum strain changes during dips allowed unambiguous definition of a kinematic variable. The several other methods of interpreting dip test data by attempting to measure strain rates shortly after the unloading decrements were found not to be satisfactory. The nature of the instantaneous unloading strains and the strain transients following unloading are also discussed in terms of the mechanisms of deformation in Alloy 800. 9 figures, 3 tables.
The total photoabsorption cross section on a free proton was measured at the GRAAL facility in the energy range E ? = 600?1500 MeV. The large-aperture LAGRAN?E detector and a liquid hydrogen target were used in the experiment performed with a back-scattered Compton gamma beam. To improve the accuracy, two alternative methods were employed. First, a subtraction method of using empty-target measurements allowed the cross section ? tot to be evaluated directly because of a low level of the electromagnetic background. Second, an algorithm for evaluating ? tot on the basis of summing the dominating partial cross sections was developed. Experimental results obtained for ? tot by the two methods are compared with existing data.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of sample preparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
The research committee of the Atomic Energy Society of Japan on water chemistry standard aims at establishing the private standard of water chemistry of nuclear power plants. The committee gathers up 'BWR water chemistry management manual', 'PWR primary system water chemistry management manual' and 'PWR water chemical analysis standard method', and furthermore aims at the standardization of those in future. Looking back on the committee's activities for the past four years, latest results of research of water chemistry mainly contributing to safe and reliable nuclear power plants were described with the future perspective of water chemistry and a demanded break-through. (T.T.)
This paper reports advances in the development of solar cells made from GaAs-on-Si structures prepared by metalorganic chemical vapor deposition (MOCVD). The use of concentrator cells, operating at [similar to]200 suns, has led to the efficiency achievements of 21.3% (AM1.5D) for a GaAs-on-Si solar cell, and 27.6 (AM1.5D) for a homoepitaxial GaAs cell. The development of epitaxial multilayer dielectric mirrors (Bragg reflectors), as back-surface reflectors in thin-film GaAs cells, on both Si and GaAs substrates, is shown to lead to modest efficiency increases, over that of conventional designs.
The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.
High-energy synchrotron x-ray diffraction (XRD) has been used to quantify load transfer in bovine plexiform bone. By using both wide-angle and small-angle XRD, strains in the mineral as well as the collagen phase of bone were measured as a function of applied compressive stress. We suggest that a greater proportion of the load is borne by the more mineralized woven bone than the lamellar bone as the applied stress increases. With a further increase in stress, load is shed back to the lamellar regions until macroscopic failure occurs. The reported data fit well with reported mechanisms of microdamage accumulation in bovine plexiform bone.
We discuss theoretically and numerically the intramolecular form factor $F(q)$ in dense polymer systems. Following Flory's ideality hypothesis, chains in the melt adopt Gaussian configurations and their form factor is supposed to be given by Debye's formula. At striking variance to this, we obtain noticeable (up to 20%) non-monotonic deviations which can be traced back to the incompressibility of dense polymer solutions beyond a local scale. The Kratky plot ($q^2F(q)$ {\\it vs.} wavevector $q$) does not exhibit the plateau expected for Gaussian chains in the intermediate $q$-range. One rather finds a significant decrease according to the correction $\\delta(F^{-1}(q)) = q^3/32\\rho$ that only depends on the concentration $\\rho$ of the solution, but neither on the persistence length or the interaction strength.
Work on the coke oven gas cleaning demonstration project (CCT-11) this quarter has focused on Phase IIB tasks, and include engineering, construction, and training. Additionally, plans for changes in the operating schedule of the coke plant that affect the demonstration project are described. The project Milestone Schedule and Log is shown. Planned Baseline Supplemental Monitoring activities described in the Environmental Monitoring Plan were completed. Testing of the mechanical systems began in June, 1991. The cold commissioning date has been moved back from October 1, 1991 to November 1, 1991 to allow float for miscellaneous finish-up items beyond the electrical contractor`s projected completion date of October 31, 1991.
This paper seeks to challenge the traditional way in which we assess the value of green buildings in terms of their environmental friendliness, energy efficiency and whole life cost. In the UK, quantity surveyors (or cost consultants) have a perception that more energy efficient and environmentally friendly buildings cost between 5% and 15% more to build from the outset. This common assumption is not backed up by recent research and should be questioned. Construction professionals need to be informed of the whole life cost and environmental impact of buildings so that they can encourage key stakeholders to make more sustainable choices. These emerging issues together with practical tools are considered with case studies from recent projects. (Author)
Indoor and soil gas Radon (222Rn) concentration measurements were accomplished in two stages in Sivas, a central eastern city in Turkey. In the first stage, CR-39 passive nuclear track detectors supplied by the Turkish Atomic Energy Authority (TAEA) were placed in the selected houses throughout Sivas centrum in two seasons; summer and winter. Before the setup of detectors, a detailed questionnaire form was distributed to the inhabitants of selected houses to investigate construction parameters and properties of the houses, and living conditions of inhabitants. Detectors were collected back two months later and analysed at TAEA laboratories to obtain indoor 222Rn gas concentration values. In the second stage, soil gas 222Rn measurements were performed using an alphameter near the selected h...
This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. With this arrangement, a high percentage of the solar power input is retained in the ...
This paper presents two imaging methods by using cross correlation. The one method images the subsurface by cross-correlation of the observed data and partial derivative seismograms calculated for a guessed model. The other method images the interface by use of cross-correlation of the virtual sources and the back propagated wave fields calculated from the observed data. Experimental tests show that both methods image subsurface interfaces well even if the guessed model is different from the true one. These imaging methods are reverse time migration that we perform cross-correlation as an imaging condition and have an advantage, as compared to conventional waveform inversion method, that images subsurface structure without iterative perturbation of the assumed model. (author). 18 refs., 15 figs.
In vibration control field, magneto-rheological (MR) fluid dampers are semi-active control devices that have recently begun to receive more attention. This paper presents a black-box model (BBM) for identification of a MR fluid damper and its application to vibrating control systems using that damper with self-sensing behavior. A model named ''black-box'' is a simple direct modeling method which is designed for a typical MR fluid damper using the self-tuning fuzzy technique. The characteristics of the researched damper are directly estimated through a fuzzy mapping system. In order to improve the accuracy of the proposed model, the back propagation algorithm and gradient descent method were used to train the fuzzy parameters to minimize the model error function. Consequently, the BBM with ...
A series of SiAlON materials with a cordierite-based matrix were annealed for different lengths of time to cause crystallization of the glass phase. Their fracture toughness, hardness, and elastic modulus were measured from room temperature up to 1100"0C. The fracture toughness generally decreased with temperature. Short time annealing raised toughness at lower temperatures, while further annealing lowered it back to the value for as-hot pressed materials. At higher test temperatures annealing had no effect on toughness. This annealing behavior is significantly different from that previously reported in the system SaAlON-YAG. Hardness decreased monotonically with temperature for all samples. Both hardness and the elastic modulus were not affected by the annealing treatment. At elevated temperatures appreciable scatter of modulus results allowed only a rough trend of decrease with temperature to be observed.
Midway Labs currently produces a 335x concentrator module that has reached as high as 19{percent} active area efficiency in production. The current production module uses the single crystal silicon back contact SunPower cell. The National Renewable Energy Lab has developed a multi junction cell using GalnP/GaAs technologies. The high efficiency ({gt}30{percent}) and high cell voltage offer an opportunity for Midway Labs to develop a tracking concentrator module that will provide 24 volts in the 140 to 160 watt range. This voltage and wattage range is applicable to a range of small scale water pumping applications that make up the bulk of water pumping solar panel sales. {copyright} {ital 1997 American Institute of Physics.}
Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces ideally mosaic crystals, and may account for the polymorphs'' of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes worm holes'' in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100[degrees]C lock in the mechanical twins.
Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces ideally mosaic crystals, and may account for the ``polymorphs`` of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes ``worm holes`` in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100{degrees}C lock in the mechanical twins.
We propose and analyze a novel regenerative amplifier free electron laser (FEL) to produce fully coherent x-ray pulses. The method makes use of narrow-bandwidth Bragg crystals to form an x-ray feedback loop around a relatively short undulator. Self-amplified spontaneous emission (SASE) from the leading electron bunch in a bunch train is spectrally filtered by the Bragg reflectors and is brought back to the beginning of the undulator to interact repeatedly with subsequent bunches in the bunch train. The FEL interaction with these short bunches not only amplifies the radiation intensity but also broadens its spectrum, allowing for effective transmission of the x-rays outside the crystal bandwidth. The spectral brightness of these x-ray pulses is about two to three orders of magnitude higher than that from a single-pass SASE FEL.
The so-called spectral dimension is a scale-dependent number associated with both geometries and field theories that has recently attracted much attention, driven largely though not exclusively by investigations of causal dynamical triangulations (CDT) and Horava gravity as possible candidates for quantum gravity. We advocate the use of the spectral dimension as a probe for the kinematics of these (and other) systems in the region where spacetime curvature is small, and the manifold is flat to a good approximation. In particular, we show how to assign a spectral dimension (as a function of so-called diffusion time) to any arbitrarily specified dispersion relation. We also analyze the fundamental properties of spectral dimension using extensions of the usual Seeley-DeWitt and Feynman expansions, and by saddle point techniques. The spectral dimension turns out to be a useful, robust and powerful probe, not only of geometry, but also of kinematics.
Organic/metal interface properties are of high interest for the application of molecular (sub)monolayers to modify surface properties. They are applied for, e.g., molecular electronics, chemical sensing, or the tuning of injection barriers in organic electronic devices. We present a joint theoretical and experimental study of F{sub 4}TCNQ adsorbed on Cu(111). The electronic and structural properties were determined by ultraviolet photoelectron spectroscopy (UPS) and X-ray standing wave (XSW) measurements. To better understand the complex process of binding, we modelled the system using density-functional theory. We find forward-donation from the lone pairs of the molecule into metallic states and back-donation from the metal into the LUMO of the molecule. The data on Cu(111) are compared to F4TCNQ on Au(111) and Ag(111) as well as to investigations of pyrenetetraone on various coinage metals.
Up to 90% of the life time of cyclically loaded components is determined by short crack initiation and propagation. This stage of the fatigue damage process is strongly influenced by microstructural features, e.g. grain boundaries and crystallographic grain orientation. Therefore LEFM can not be applied in a reasonable manner explaining the demand for a mechanism-related modelling method. The present study deals with mechanical testing and microstructural examinations applied to the relatively new #beta#-titanium alloy LCB. The results are used as data base to develop a new short crack model that is based on the model of Navarro and de los Rios. By using various techniques such as electron back-scattered diffraction and finite-element calculations the origin of crack initiation is revealed and the characteristics of crack propagation is determined. (orig.)
Abstract- In our reply to M. H. van IJzendoorn and M. J. Bakermans-Kranenburg (this issue) and R. A. Thompson (this issue), we highlight 2 challenges that attachment researchers face today: (a) closing the gap between the developmental and social psychological traditions and (b) connecting attachment theory to the broader field of evolutionary psychology. We contend that an evolutionary life history approach can contribute to both goals and argue that attachment researchers should consider moving beyond some of Bowlby's original formulations in order to permit further advancement of the field. Finally, we review van IJzendoorn and Bakermans-Kranenburg's criticism of the hypothesis that sex differences in attachment arise in middle childhood; we conclude that the claim that the hypothesis h...
Males and females display differences in physiology, behaviour and susceptibility to many diseases. Genome-wide transcription profiling studies have uncovered large-scale sex differences in autosomal gene expression in somatic tissues that are thought to underlie such 'sexual dimorphisms'. Because males and females differ genetically mainly in their sex chromosome complement, most sex differences can be traced back to the X and Y chromosomes. Although sex hormones are usually considered the main architects of sexual dimorphisms, recent studies have demonstrated that sex chromosomes can also induce sex differences in somatic gene expression in the absence of hormonal differences. The recent discovery of epigenetic sex differences that are not hormone-induced brings us closer to understandin...
Philosophy of science was once a much more socially engaged endeavor, and can be so again. After a look back at philosophy of science in the 1930s?1950s, I turn to discuss the current potential for returning to a more engaged philosophy of science. Although philosophers of science have much to offer scientists and the public, I am skeptical that much can be gained by philosophers importing off-the-shelf discussions from philosophy of science to science and society. Such efforts will likely look like efforts to do applied ethics by merely applying ethical theories to particular contexts and problems. While some insight can be gained by these kinds of endeavors, the most interesting and pressing problems for the actual practitioners and users of science are rarely addressed. Instead, I recom...
A new mathematical framework is formulated to derive the effective equations of motion for the constrained quantum system which possesses an internal clock. In the realm close to classical behavior, the quantum evolution is approximated by a finite system of coupled but ordinary differential equations adhered to the weakly imposed Hamiltonian constraint. For the simplified version of loop quantum cosmology in the Bianchi I model with a free massless scalar filed, the resulting effective equations of motion affirm the bouncing scenario predicted by the previous studies: The big bang singularity is resolved and replaced by the big bounces, which take place up to three times, once in each diagonal direction, whenever the directional density approaches the critical value in the regime of Planckian density. It is also revealed that back-reaction arises from the quantum corrections and modifies the precise value of the directional density at the bouncing epoch. ...
There are no specific diagnostic tests or a gold standard method for measuring disease activity and outcome in spondyloarthropathies (SpA). Many different methods have been developed to assess the signs and symptoms in SpA. The aim of this study was to evaluate the value of scintigraphy, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Bath Ankilosing Spondylitis Disease Activity Index (BASDAI) in the evaluation of disease activity in early axial SpA diagnosed with magnetic resonance imaging (MRI). Thirty early MRI-positive axial SpA patients (23 males, 7 females) with a median age of 35 (18?55) years and a median duration of inflammatory low back pain of 24 (8?60) months were included in the study. In the patients with sacroiliitis, the sensitivity, specificity, and pos...
Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene.
This paper reports on a flexible dimensionaly flush joint for 500kV aluminum-sheathed oil-filled cables capable of being assembled, pulled an installed in a similar manner to cables at site which has been developed. This joint is intended for use at intermediate points on long bridges or tunnels where local assembly and installation of conventional joints would be difficult. In developing the joint various novel and original techniques have been employed, including the flexible flush jointing of segmental conductors, the flexible jointing of paper insulation by a combination of wrapping-back and stepping methods, plus on-site aluminum sheath corrugating and sealing methods.
This paper presents the development of technical requirements for the design of aircraft-mounted sampling equipment for the airborne radioactivity monitoring. A design concept and internal equipments required for the sampling system will be described in detail to provide information for the development of technical requirements for aircraft-mounted sampling equipment. This will be followed by description of the exterior designing process. Difficulties of designing exterior of the sampling system lie in the fluid dynamics performance of the system. The objective of the design is to maximize the suction flow necessary for achieving high efficiency of radionuclide sampling, while minimizing disturbance to the aircraft which carries the system. The design optimization was performed with the computational fluid dynamics (CFD) code FLUENT. The design options considered here were (1) diameter to head ratio of top and back head, (2) nozzle length and (3) nozzle diameter of ...
Purpose - This study aims to design and test some fixed-wing micro aerial vehicles (MAV). Design/methodology/approach - The MAV wing planform in this study was designed based on previous results and the need to reduce the weight of the MAV. The MAV had a wing planform with a 6 percent Gottingen-329 camber airfoil, a 20 swept-back leading edge and a straight trailing edge. The fuselage was designed to contain a motor, an electronic control system and a video camera with a built-in transmitter. The battery was located outside the fuselage to trim the center of gravity and enable the battery to be changed easily when it has run out. Two exaggerated vertical stabilizers were installed to prevent the MAV from rolling. The materials, the power plant and the electronics used to fabricate the MAV ...
Conversion of Idaho National Engineering and Environmental Laboratory radioactive sodium-bearing waste into a single solid waste form by evaporation was demonstrated in both flask-scale and pilot-scale agitated thin film evaporator tests. A sodium-bearing waste simulant was adjusted to represent an evaporator feed in which the acid from the distillate is concentrated, neutralized, and recycled back through the evaporator. The advantage to this flowsheet is that a single remote-handled transuranic waste form is produced in the evaporator bottoms without the generation of any low-level mixed secondary waste. However, use of a recycle flowsheet in sodium-bearing waste evaporation results in a 50% increase in remote-handled transuranic volume in comparison to a non-recycle flowsheet.
Off-axis electron holography is used to characterize a linear array of transistors, which was prepared for examination in cross-sectional geometry in the transmission electron microscope (TEM) using focused ion beam (FIB) milling from the substrate side of the semiconductor device. The measured electrostatic potential is compared with results obtained from TEM specimens prepared using the more conventional 'trench' FIB geometry. The use of carbon coating to remove specimen charging effects, which result in electrostatic fringing fields outside 'trench' specimens, is demonstrated. Such fringing fields are not observed after milling from the substrate side of the device. Analysis of the measured holographic phase images suggests that the electrically inactive layer on the surface of each FIB-milled specimen typically has a thickness of 100 nm.
The construction and the development of a UV free electron laser have been started under the cooperation of Nihon U, KEK, PNC, ETL and Tohaku U. The project requires a 100MeV S-band electron linear accelerator to expand the oscillation of FEL using fundamental mode to the UV region. The injection system consists of a thermionic RF-gun with a LaB cathode and an {alpha} magnet for magnetic bunching. We are studying to reduce the back-bombardment electrons to realize the macropulse length of 20{mu}sec. Electron beams, up to the energy of 100MeV, are injected into the optical oscillators. Changing the accelerating energy and/or undulator parameters, this system will cover the range from infrared to ultraviolet for the applications in various fields.
Recent advances in our understanding of the higher-wave quarkonia have generated much interests in quarkonium physics. However most are devoted to inclusive decays and productions. Experimental data of several two-body exclusive decay channels of P-wave charmonia such as \\pi \\pi and p \\bar p are available and some have recently been re-measured by the BES collaboration. It is not clear from the outset that color octet is needed for these exclusive channels. Indeed only color singlet has been used in the past and reasonable agreement with data was found. Contrary to these old results, we provide theoretical arguments for the inclusion of color octet and perform explicit calculations to back this up.
In general relativity, the fields on a black hole horizon are obtained from those in the bulk by pullback and restriction. Similarly, in quantum gravity, the quantized horizon degrees of freedom should result from restricting, or pulling-back, the quantized bulk degrees of freedom. This is not yet fully realized in the - otherwise very successful - quantization of isolated horizons in loop quantum gravity. In this work we outline a setting in which the quantum horizon degrees of freedom are simply components of the quantized bulk degrees of freedom. There is no need to quantize them separately. We present evidence that for a horizon of sphere topology, the resulting horizon theory is remarkably similar to what has been found before.
Bioremediation technology is being evaluated for use on the Kwajalein Atoll, which is located in the Republic of the Marshall Islands. The study was undertaken by the Oak Ridge National Laboratory (ORNL) on behalf of the US Army Kwajalein Atoll (USAKA). During February of 1991, a team from ORNL and The University of Tennessee (UT) visited the USAKA. In addition to making on-site observations regarding microbial abundance and distribution of petroleum contaminants, they brought back to Oak Ridge various soil and water samples for detailed analyses. This report documents the biological studies of these samples and presents observations made during the period from February to April of 1991 by investigators at ORNL, UT, and the Oak Ridge Associated Universities.
In order to investigate the behaviour of the turbine control system during strong pendulum motions, an analysis is carried out using a digital computer program by which the reactor, the turbine, the generator and, in a simplified way, the network can be simulated to the necessary degree. Plotter pictures can show the main physical quantities. In all cases, the turbine control system should be able to distinguish between strong pendulum amplitude with acceleration of the rotational angles and sudden release criteria. This demand can be satisfied by a simple adjustment in the Kraftwerk Union turbine control system. Only a few seconds after shut-off of a severe network failure, the turbines are back to their rated power, thus contributing to reliability of supply in this critical network situation. (orig.).
We present a fully automated method for three-dimensional (3D) elemental analysis demonstrated using a ceramic sample of chemistry (Ca)MgTiO_x. The specimen is serially sectioned by a focused ion beam (FIB) microscope, and energy-dispersive X-ray spectrometry (EDXS) is used for elemental analysis of each cross-section created. A 3D elemental model is reconstructed from the stack of two-dimensional (2D) data. This work concentrates on issues arising from process automation, the large sample volume of approximately 17x17x10 #mu#m"3, and the insulating nature of the specimen. A new routine for post-acquisition data correction of different drift effects is demonstrated. Furthermore, it is shown that EDXS data may be erroneous for specimens containing voids, and that back-scattered electron images have to be used to correct for these errors.
The Elman artificial neural network (ANN) (feedback connection) was used for seismic data filtering. The recurrent connection that characterizes this network offers the advantage of storing values from the previous time step to be used in the current time step. The proposed structure has the advantage of training simplicity by a back-propagation algorithm (steepest descent). Several trials were addressed on synthetic (with 10% and 50% of random and Gaussian noise) and real seismic data using respectively 10 to 30 neurons and a minimum of 60 neurons in the hidden layer. Both an iteration number up to 4000 and arrest criteria were used to obtain satisfactory performances. Application of such networks on real data shows that the filtered seismic section was efficient. Adequate cross-validation test is done to ensure the performance of network on new data sets.
An enriched culture 48, capable of adapting to the reservoir conditions and fermenting molasses to produce gas and acid, was used as an inoculum for bio- huff-`n`-puff tests at Fuyu oil area of Jilin oil field. The production well was injected with water containing 4-6% (v/v) molasses and inoculum, and then shut in. After 15-21 days, the well was placed back in operation. A total of 44 wells were treated, of which only two wells showed no effects. The daily oil production of treated wells increased by 33.3-733.3%. Up to the end of 1994, the oil production was increased by 204 tons per well on average. Results obtained from various types of production wells were discussed.
The gliding modes of a duplex Ti-6Al-4V titanium alloy were investigated through in situ (scanning electron microscopy) tensile tests. A method based on electron back-scattering diffraction (EBSD) measurements was used to identify activated slip systems. The approach applied to a large number of grains allowed a statistical analysis of the nature (basal, prismatic, pyramidal) and distribution of the slip systems according to the crystallographic texture. A discussion concerning the pertinence of Schmid's law to explain the occurrence and succession of slip events is then proposed. The domain in favor of each type of slip system is finally presented by using inverse pole figures mapped with Schmid's factor iso-curves.
In this paper an efficient quantum secure direct communication (QSDC) scheme with authentication is presented, which is based on quantum entanglement and polarized single photons. The present protocol uses Einstein-Podolsky-Rosen (EPR) pairs and polarized single photons in batches. A particle of the EPR pairs is retained in the sender's station, and the other is transmitted forth and back between the sender and the receiver, similar to the ``ping-pong'' QSDC protocol. According to the shared information beforehand, these two kinds of quantum states are mixed and then transmitted via a quantum channel. The EPR pairs are used to transmit secret messages and the polarized single photons used for authentication and eavesdropping check. Consequently, because of the dual contributions of the polarized single photons, no classical information is needed. The intrinsic efficiency and total efficiency are both 1 in this scheme as almost all of the instances are useful and ...
A recently-developed BMT method combines a ''Perfusion Method'' (PM) for collecting bone marrow cells (BMCs) with the Intra-Bone Marrow (IBM) injection of BMCs (IBM-BMT). As distinct from the conventional aspiration method (AM), the PM allows rapid (within 1 h) collection of BMCs without T cell contamination (T cells < 10%). Therefore, no GvHD occurs. Moreover, the burden on donors, such as back pain, bleeding and infection, can be reduced. Full chimerism can be achieved even with only mild conditioning regimens if IBM-BMT is carried out, since IBM-BMT replaces not only the recipient's hemopoietic stem cells (HSCs) but also mesenchymal stem cells (MSCs) with donor-derived HSCs and MSCs. Using this method, we show that most currently intractable diseases are HSC or MSC disorders, and that t...
A recently developed hydrodistillation?solvent microextraction (HD?SME) method coupled to gas chromatography?mass spectrometry (GC?MS) was applied to the analysis of volatile components of aerial parts of Echinophora cinerea (Boiss). By the use of a simplex optimization method, the effects of extraction time, sample weight and microdrop volume on the extraction efficiency of the method were optimized. In the optimized conditions, 3??L of n-heptadecane was suspended in the headspace of 6?g of hydrodistillating sample, using a microsyringe. After 7?min, the solvent was retracted back into the syringe and directly injected into the GC?MS injection port. The HD?SME method was compared to a conventional hydrodistillation technique. In general, the extraction with HD?SME was relatively faster an...
Aims: This study sought to elucidate the effects of timolol and dorzolamide on intraocular pressure (IOP) and retinal ganglion cell (RGC) death in an experimental...Full Text Available
The completed ribbon-winding theory, including temperature loading of the high-pressure compound vessel, was proposed. The influence of the bending stress in the wound ribbon is taken into account. Internal core of the compound vessel consists of matrix and ring, made of different materials. The relations were derived in analytical form, describing the radial distribution of necessary tangential prestressing.
The high pressure discharges (pulsed or D C corona, barrier, gliding and the others), have been studied both experimentally and theoretically as sources of low temperature plasma for pollution control technologies. The potential of electrical discharge methods has been demonstrated for the decomposition of many types of VOC. The air or oxygen are used as a feed gas in which pollutant is diluted. The ozone production in air or oxygen in such discharges is also discussed
The pressure of a 6:12 fluid is obtained from the Percus-Yevick theory at the temperature kT/? = 1.35. The energy equation results are in excellent agreement with machine calculation results in contrast to the pressure and compressibility equation results. Present address: Diffusion Research Unit, The Australian National University, Canberra, ACT, Australia.
A radon detector with LR-115 nuclear track film was constructed for radon concentration measurements in soil. Temporal radon variations, as well as the barometric pressure, precipitation and temperature were measured for two years. Negative correlation between radon concentration in soil and barometric pressure was found. For some of the recorded earthquakes that occurred during the observation period, soil radon anomalies may be noticed one month before the quakes.
Graphite intercalation compounds, Rb{sub x}KC{sub 8}, Cs{sub x}KC{sub 8} and Na{sub x}KC{sub 8}, x{approx equal}1-1.3, are obtained under pressures up to 80 kbar using KC{sub 8} as the initial compound. Total contents of alkali metals in these compounds correspond to the formula MC{sub 3.5-4.0}. (orig.).
In combined cycle turbine power stations, soft material compensators are used which, if the full pressure fails, also withstand a small external pressure. Innovative forms of construction which guarantee useful life, are presented in relation to the design. Damaging effects, which limit the life of these special soft material compensators, are discussed. (orig.)
The paper deals with a model in which the motion of a gas in plasma accerators and high-curent discharges in the present of a skin effect is treated as expulsion by a 'magnetic piston' under the action of surface current flow. Specifically examined is the situation where the initial gas pressure is negligible in comparison with the magnetic pressure, and the motion of the gas may be treated as a self-simulating one. A system of hydrodynamic equations of the problem is derived and integrated by Adam's method. Results are plotted and discussed.
Calorimetry testing of Tri-n-butyl phosphate (TBP) saturated with strong nitric acid was performed to determine the relationship between vent size and pressure buildup in the event of a runaway reaction. These experiments show that runaway can occur in an open system, but that even when runaway is induced in the TBP/HN0{sub 3} system, dangerous pressure buildup will be prevented with practical vent size.
This rebuttal to a previous article provides new insight into the use of sprayed sealants in uranium mines. The author rejects the idea that the value of rock sealant on radon control is destroyed by changes in barometric pressure, showing that this is not necessarily true. The analyses described demonstrate that radon contamination resulting from changing barometric pressures is reduced by a rock coating. The overall use of coatings depends on their costs and effectiveness as compared with other radon control measures. 6 refs.
Since the first commercial operation in 1983, Wolsung unit 1 has experienced several aging phenomena, especially in pressure tubes and feeder pipes. In case of pressure tubes, in-service inspections (ISI) revealed that a major portion of inspected tubes was in contact with calandria tubes. The likelihood of blister formation was a safety concern because it is a potential threat to pressure tube integrity. Wolsung unit 1 was, therefore, subjected to the SLAR (Spacer Location And Reposition) work to separate the contacted pressure tubes from calandria tubes. In this paper, experience of in-service inspection to the pressure tubes will be discussed including the irradiation creep elongation and CIGAR (Channel Inspection and Gauging Apparatus for Reactors) examination of pressure tubes. On the other hand, the problem of wall thinning in the feeder pipes became of ...
Since the first commercial operation in 1983, Wolsung unit 1 has experienced several aging phenomena, especially in pressure tubes and feeder pipes. In case of pressure tubes, in-service inspections (ISI) revealed that a major portion of inspected tubes was in contact with calandria tubes. The likelihood of blister formation was a safety concern because it is a potential threat to pressure tube integrity. Wolsung unit 1 was, therefore, subjected to the SLAR (Spacer Location And Reposition) work to separate the contacted pressure tubes from calandria tubes. In this paper, experience of in-service inspection to the pressure tubes will be discussed including the irradiation creep elongation and CIGAR (Channel Inspection and Gauging Apparatus for Reactors) examination of pressure tubes. On the other hand, the problem of wall thinning in the feeder pipes became of ...
There is need of pressure surge analyses when valves or pumps are activated or piping systems fail (pipe rupture). Based on actual problems the influences of boundary conditions upon fluid simulation results are discussed. Hints concerning realistic dynamic analyses of piping systems are presented. Some of the simulations results are compared with measurements. (orig.)
We extend the analysis of a previous paper to the bosonic case and find the one-derivative effective action valid in the vicinity of rolling tachyons with an energy not larger than that of the original D-brane. For on-shell tachyons rolling down the well-behaved side of the potential in this theory, the energy is conserved and the pressure eventually decreases exponentially. For tachyons rolling down the 'wrong' side, the pressure instead blows up in a finite time. (author)
Partial Contents: Ternary Compounds; Granular Superconductors; Superconductivity in (SN)x and its Halogen Derivative (SNBr0.4)x; Studies of cuCl at Elevated Pressures; Superconducting Properties of Hydride Systems; Thin Film Superconducting Materials Research; Synthesis of Superconducting Nb3Si using High Pressures; Synthesis of Unstable A-15 Compounds by Epitaxial Recrystallization of Ion Implanted Layers; and Sputtering of Nb3Si.
High pressure experiments in a jet-stirred reactor have been performed to study the NO{sub x} formation in lean premixed combustion of methane/air mixtures. The experimental results are compared with numerical predictions using four well known reaction mechanisms and a model which consists of a series of two perfectly stirred reactors and a plug flow reactor. (author) 2 figs., 7 refs.
This investigation involves a study of the influence of key processing parameters on the heating of materials using microwave energy. Selective and localized heating characteristics of microwaves will be utilized in the sintering of ceramics without hydrostatic pressure. In addition, combustion synthesis will be studied for the production of powders, carbides, and nitrides by combining two or more solids or a solid and a gas to form new materials. The insight gained from the interaction of microwaves with various materials will be utilized in the mobilization and subsequent redeposition of uranium.
The authors propose an integrated indicator of pump-rod couplings that allows both the couplings and the pump operations to be appraised according to the given formula. (Formula provided). The dynamic relationships of rod operations were determined with nomographs. These relationships involve such factors as: the type and size of the sucker-rod string; the pressure load at the equalizer head and its correlation to threshold pressure at pump discharge; pump diameter; the rod weight and construction; and integral reliability indicators.
A mathematical model is proposed for three-phase filtering which is a particular case of a more general model of filtering multiple component mixtures and makes it possible to describe three-phase filtering flows under conditions where the pressure of saturation is variable in time and in space. In the proposed model, the system of unknown functions is selected so that it makes it possible to trace fairly simply the pressure of saturation and to compute the corresponding equation coefficients.
The purpose of this paper is to demonstrate how recent experimental results of "1"5"1Eu and "5"7Fe high pressure Moessbauer studies in 4f and 3d metallic magnetic systems can contribute to a deeper understanding of the nature of local moment (4f) and itinerant (3d) magnetism in these systems. Special emphasis is given on the comparison of the experimental results with related theoretical models. (orig.).
An advanced ceramic dome cavity receiver is discussed which heats pressurized gas to temperatures above 1800/sup 0/F (1000/sup 0/C) for use in solar Brayton power systems of the dispersed receiver/dish or central receiver type. Optical, heat transfer, structural, and ceramic material design aspects of the receiver are reported and the development and experimental demonstration of a high-temperature seal between the pressurized gas and the high-temperature silicon carbide dome material is described.
Plasma with a gas temperature below room temperature is not yet fully understood although it is expected to be an attractive tool for applications to material processing. In the present work, gas-temperature-dependent generation of a cryoplasma jet was studied. So far, we have generated a helium cryoplasma jet (296-5 K) under atmospheric pressure. At gas temperatures below 20 K, the helium excimer, He2, was observed clearly from by optical emission spectroscopy.
In the case of large capacity steam turbines the conventional nozzle group control is, for mechanical and thermodynamic reasons, diminishing more and more in importance in favour of variable pressure control. A design for constant-pressure operation as an alternative to nozzle group control is described; this demonstrates a series of important advantages compared with the latter. (orig.).
Transit time, the time from bridgewire burst until breakout of detonation from the output pellet of an exploding bridgewire detonator, was measured as a function of burst current. From this data, in conjunction with known equations for run distance versus pressure, unreacted explosive Hugoniots, and detonation properties of the initial pressing pellet, the run distance in the initial pressing explosive pellet and shock pressure from the exploding bridgewire were determined, both as a function of burst current.
An important advantage of carrying out enzymatic catalysis in organic media is the increased solubility of hydrophobic substrates. This study compares a model lipase catalyzed esterification of cholesterol using vinyl acetate (VA) in two such nontraditional media: high-pressure hexane and supercritical (SCF) ethane. The effect of using one of the reactants (VA) as a cosolvent to increase the solubility of the other reactant (cholesterol) in SCF ethane has been investigated. The thermodynamic activity of water (a(w)) in the reaction media was controlled by the direct addition of the salt hydrate pair Na(4)P(2)O(7)/Na(4)P(2)O(7).10H(2)O. The a(w) of the salt hydrate system is shown to be a function of pressure and its variation over the pressure range 104-173 bar has been estimated. The initial reaction rate in pressurized hexane was found to vary linearly with the cholesterol concentration. The reaction ...
After the completion of the 4MWth pilot plant of the Pressurizied Internally Circulating Fluidized-bed Boiler (PICFB), a total of 15 test runs, amounting to 2280 hours of operation, were concluded. The test results have confirmed the superior operating performance. Additionally, Ebara plans to develop a Pressurized Internally Circulating Fluidized-bed Gasifier (PICFG or Advanced PICFB). 8 figs.
This standard addresses the design bases for light water reactor, nuclear power plant structures and components essential for the protection of public health and safety from the potential adverse effects of pipe whip, jet impingement, pressurization of compartments outside containment, environmental conditions and flooding associated with a postulated pipe rupture. The design bases for missile protection and the design bases for containment pressurization are not within this standard.
A combined gas/steam turbine process includes a high-pressure furnace and a high pressure gasification unit with a mounted upstream of a combustion chamber there is a gas turbine with a waste heat system. Combustion heat which is not needed to heat the flue gas to combustion temperature is released from the furnace and transferred to ths combustion air going into the combustion chamber.
... Cholesterol High Blood Glucose High Blood Pressure Overweight Physical Activity Small Steps for Your Health Smoking Age, ... blood pressure, unhealthy cholesterol, and high blood glucose. Physical Activity Staying active helps manage your blood glucose, ...
The corrosion rate of low alloy steel SA-508 and carbon steel A-410b in simulated operation and shutdown conditions of pressurized water reactor has been determined Moreover potentiodynamic polarization curves and galvanic effect through coupling of AISI-304 have been carried out under shutdown simulated condition. (Author) 8 refs.
A physical explanation is given for the positive differential voltage-current characteristic seen at low current in weakly ionized, low-pressure positive column discharges in argon/mercury gas mixtures. {copyright} {ital 1996 The American Physical Society.}
This standard addresses the design bases for light water reactor, nuclear power plant structures and components essential for the protection of public health and safety from the potential adverse effects of pipe whip, jet impingement, pressurization of compartments outside containment, environmental conditions and flooding associated with a postulated pipe rupture. The design bases for missile protection and the design bases for containment pressurization are not within this standard.
The present invention is a fully connected feed forward network that includes at least one hidden layer 16. The hidden layer 16 includes nodes 20 in which the output of the node is fed back to that node as an input with a unit delay produced by a delay device 24 occurring in the feedback path 22 (local feedback). Each node within each layer also receives a delayed output (crosstalk) produced by a delay unit 36 from all the other nodes within the same layer 16. The node performs a transfer function operation based on the inputs from the previous layer and the delayed outputs. The network can be implemented as analog or digital or within a general purpose processor. Two teaching methods can be used: (1) back propagation of weight calculation that includes the local feedback and the crosstalk or (2) more preferably a feed forward gradient decent which immediately follows the output computations and which also includes the local feedback and the ...
Among KEPCO's 9 nuclear power units, Korea Nuclear Unit No. 3, the Wolsung Nuclear Power Plant is the only CANDU-PHWR Unit, while the rest of 8 others are PWR units. The unit was designed by Atomic Energy of Canada, Ltd. of Canada, who also performed overall project management for the plant construction under the provisions and arrangement of the relevant contracts. The gross electrical output of the plant is 678.7 MWe and thermal output of the reactor is 2061 MWth. While these figures lead to lower plant efficiency than LWR counterparts, unit energy cost for fuel is more favorable than LWRs because natural uranium is utilized for the fuel bundles, some of which are already being fabricated domestically. Annual capacity factors for 1983 and 1984 could have been improved, if two major planned outages for the modification works on steam generator internals and one major forced outage from the heavy water spill incident could be eliminated. The heavy water spill incident in ...
Full text: Semiconductor detectors coated with boron or lithium compounds have been studied for neutron detection for decades but, until recently, have been limited to thermal neutron detection efficiencies of less than 5%. We reported previously on development and simulation studies of perforated detectors whose perforations are filled with neutron-reactive material in order to produce higher detection efficiencies. Incorporation of bare and cadmium-backed detectors into battery-powered devices with low-power electronics enables us to produce compact personal neutron dosimeters that provide LED readout of counts, which can be related approximately to neutron dose. We report here on experimental studies with such compact devices; devices capable of direct readout in dose units are anticipated. The thermal and epithermal neutron flux densities from the tangential beam tube of the TRIGA Mark II reactor at Kansas State University were measured. Then, thermoluminescent ...
The transfer of 203Pb and/or 47Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). 203Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of 203Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of 203Pb by intestinal tissue but did accelerate 203Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased 47Ca tissue levels and increased 47Ca absorption. In rachitic chicks, the rate of absorption of 203Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in al segments was similar, indicting the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum greater than ileum. An acute dose of 1,25(OH)2D3 to rachitic chicks also enhanced both ...
The transfer of /sup 203/Pb and/or /sup 47/Ca across the intestinal epithelium of the chick was investigated, with emphasis given to the functional role of cholecalciferol (vitamin D-3). /sup 203/Pb, after introduction in the intestinal lumen, is rapidly accumulated by the intestinal tissue, and only a fraction of /sup 203/ Pb is translocated parenterally (absorbed). Cholecalciferol did not significantly affect the accumulation of /sup 203/Pb by intestinal tissue but did accelerate /sup 203/Pb movement across the basal-lateral membrane. In contrast, cholecalciferol both decreased /sup 47/Ca tissue levels and increased /sup 47/Ca absorption. In rachitic chicks, the rate of absorption of /sup 203/Pb was greater in the distal than in the proximal segments of the intestine; after cholecalciferol repletion, the degree of absorption in all segments was similar, indicating the order of cholecalciferol effectiveness as duodenum greater than or equal to jejunum > ileum. An acute dose of ...
Inelastic scattering of #alpha#-particles in 22-24 MeV energy range on "1"8o o, "1"9f, "2"0Ne, "2"2Ne nuclei is investigated. Measurements of excitation functions were conducted for the beam of Leningrad University cyclo otron at several angles in 15-165 deg range of laboratory system with 2.5 deg spacing. The error of determining absolute cross sections equals +-20% for "2"2Ne and +-12% for other nuclei. Angular distributions have the differaction character, are similar in form for all nuclei, the values of differential cross- -sections don't exceed the rutherford values. The dependence of integral cross-sections on the energy of level excitation is similar to the exponential d dependence of cross-sections of production of the given element isotopes on the gergy difference of masses of final nuclear products in the reactions of deeply inelastic transfers with heavy ions. The observed isotopic effect in the value of cross-sections of elastic and inelastic #alpha#-particle scattering ...
The electronic band structure, transport properties, and lattice dynamics in AuX_2 (X = Al, Ga and In) under high pressure have been extensively studied with full potential linearized augmented plane wave and pseudopotential plane wave methods. The theoretical results for the electronic band structure and Fermi surface reveal pressure-induced electronic topological transitions (ETTs) in AuGa_2 and AuIn_2, while they are absent in AuAl_2, in excellent agreement with the experimental observations. Moreover, calculations of the transport properties at different pressures reveal subtle changes in the band structure close to the Fermi surface of the three intermetallic compounds. It is clear that the anomalies in transport properties are due to ETTs. Interestingly, a pressure-induced soft transverse acoustic (TA) phonon mode is identified only in AuGa_2. The TA phonon instability at the Brillouin zone ...
In the heat exchangers of power plants, scale deposition may occur, especially at the leading edge of contraction. The growth of scale can lead to an increase in pressure and cause oscillation of the water level. In our previous study, the dependence of flow on contraction geometry was analyzed numerically and empirically. It was shown that the contraction ratio of hydraulic diameter of the flow path contributed greatly to the difference in pressure drop and turbulent kinetic energy at the leading edge of the flow path. In this study, the effect of contraction geometry and flow rate on scale adhesion was studied in AVT chemistry at 270degC using a high-velocity scale-adhesion test loop. The differential pressure and the amount of scale deposited due to scale adhesion at the leading edge of the flow path increased more in a quatrefoil-type flow path than in drill-type flow path. The differential pressure ...
We report the results of a linearized augmented-plane-wave calculation of the electronic structure of fcc La at three lattice constants corresponding to ambient pressure, 50, and 120 kbars. The Kohn-Sham-Gaspar approximation for exchange and correlation is used and the potential is allowed a fully non-muffin-tin form. The f bands lie approx.2--2.5 eV above the Fermi level and are approx.1 eV wide, resulting in a very small (0.05 electrons) localized f occupation. Under pressure the f bands rise and broaden appreciably, resulting in only a slight increase in f occupation. The rigid-muffin-tin approximation for the electron-phonon interaction lambda overestimates the superconducting transition temperature T/sub c/ by 40%, but we find that the drastic increase in T/sub c/ under pressure can be attributed primarily to changes in the electronic stiffness eta. Structural transitions which occur at 25 and 53 kbars may be related ...
In the atmospheric pressure coal combustion area, the internally circulating fluidized bed boiler (ICFB) has already been proven to possess superior performance features in terms of the ease with which load conditions can be controlled and its low pollution level. Based on the particular merits of the ICFB furnace and the application of this technology to pressurized fluidized bed boiler technology, it was possible to achieve a pressurized fluidized bed boiler with superior ease of operation, reliability and los pollution characteristics. Cold model tests and computer simulation have been carried out to investigate the possibility of applying ICFB technology to the pressurized fluidized bed boiler technology in an attempt to develop the pressurized internally circulating fluidized bed boiler (PICFB). Based on the results achieved in this research, a hot-model design and fabrication ...
A characteristic trait of Francis turbines operating at low-head is pressure pulsations that occur during certain load levels of the generator. These stem from pressure variations across the turbine due to pulsating flow in the draft-tube. This surging action of the water column is related to draft-tube geometry and flow-rate of water in the penstock. The pressure pulsations cause torque variations on the turbine and corresponding electric power pulsations. If electric power is used as a feedback signal to the Power System Stabilizer (PSS), then Mvar and terminal voltage pulsations will occur when the generator is operating in the ``rough zone``. This paper describes field test results for investigating feedforward control from the penstock, draft tube and spiral case pressure to reduce the effects of Mw pulsations on PSS output signals. This investigation involved a PSS with generator power as the ...
Following the successful application of hydrostatic pressure in mechanistic investigations of organic reactions, chemists have launched a vigorous effort to apply this tool to substitution reactions of coordination compounds. The authors began to study pressure effects in the NMR spectra of keton-lanthanide combination with the hope that the increase shifts anticipated might enhance the utility of the method, perhaps even expand its applicability to new classes of compounds. 5-Phenyl- and 5-tert-butyladamantan-2-one, piperidine, tetrahydrofuran, and cyclopentanol exhibited pressure-reduced lanthanide-induced shifts with Eu(fod)/sub 3/; Yb(fob)/sub 3/ and the shielding reagent Pr(fod)/sub 3/ showed the same effect with adamantanone. Solvent variations (CD/sub 2/Cl/sub 2/, CCl/sub 4/) caused minor changes in the magnitude of these shifts but did not reverse any. With the objective of learning whether these effects are due to ...
The current work focuses on the pressure drop, heat transfer and stability in two phase flow in microchannels with hydraulic diameter of less than one hundred microns. Experiments were conducted in smooth microchannels of hydraulic diameter of 45, 65 {mu}m, and a rough microchannel of hydraulic diameter of 70 {mu}m, with deionised water as the working fluid. The local saturation pressure and temperature vary substantially over the length of the channel. In order to correctly predict the local saturation temperature and subsequently the heat transfer characteristics, numerical techniques have been used in conjunction with the conventional two phase pressure drop models. The Lockhart-Martinelli (liquid-laminar, vapour-laminar) model is found to predict the two phase pressure drop data within 20%. The instability in two phase flow is quantified; it is found that microchannels of smaller hydraulic diameter ...
The purpose of this project was to investigate the origin of pressure fluctuations in fluidized bed systems. The study assessed the potential for using pressure fluctuations as an indicator of fluidized bed hydrodynamics in both laboratory scale cold-models and industrial scale boilers. Both bubbling fluidized beds and circulating fluidized beds were evaluated. Testing including both cold-flow models and laboratory and industrial-scale combustors operating at elevated temperatures. The study yielded several conclusions on the relationship of pressure fluctuations and hydrodynamic behavior in fluidized beds. The study revealed the importance of collecting sufficiently long data sets to capture low frequency (on the order of 1 Hz) pressure phenomena in fluidized beds. Past research has tended toward truncated data sets collected with high frequency response transducers, which miss much of the spectral ...
In the VEGA program on radionuclide release from irradiated fuel under severe accident conditions, 10 tests in total were performed at JAEA from 1999 to 2004 under inert and steam atmospheres including the highest pressure or temperature conditions. These tests showed the increase in release rate above 2,800 K or at the fuel liquefaction and the decrease in release rate under elevated pressure, which was a first observation in the world. The data on low-volatility radionuclide release, release from MOX fuel, effect of fuel oxidation, and eutectic reaction with cladding on release were obtained from the tests. The mechanism of pressure effect on release was examined and a new release model with pressure effect was proposed. In addition, the pressure effect on source term evaluation and effectiveness of accident management measures were investigated. This article summarizes the major ...
The authors investigated the harmful effect of compound grease on premium connections. The pressure buildup of compound grease trapped between threads was measured during and after makeup of the connection. The resulting hoop stress in the coupling and the reduction in the seal interference were also measured. Mathematical models were developed to calculate coupling stress and grease pressure. Results indicate that for the conventional API buttress-thread profile, the pressure of trapped compound grease remains permanently high after the connection is made up because of the small thread-clearance area. This high pressure results in a high coupling stress and a large reduction in seal interference diameter, thereby degrading the integrity of the connection. To solve this problem, the thread profile was redesigned with a thread-clearance area larger than that of conventional buttress thread. The ...
CeO{sub 2} undergoes a first-order phase transition from fluorite to {alpha}-PbCl{sub 2}-type structure under high pressure. To evaluate the changes in physical properties of CeO{sub 2} nanomaterials as the particle size decreasing, high-pressure Raman study under quasi-hydrostatic condition has been performed on CeO{sub 2} nanospheres self-assembled by 5 nm CeO{sub 2} nanoparticles at room temperature. Surprisingly, as the pressure elevate to 34 GPa, the CeO{sub 2} nanospheres still retain the cubic fluorite-type structure, indicating the sample is more stable than the bulk counterpart. Whereas, previous high-pressure studies show the phase transition at 22.3/26.5 GPa for 12 nm CeO{sub 2} nanoparticles, which is less stable than the bulk materials. The enhancement of phase stability might be attributed to the increase of surface energy of CeO{sub 2} nanospheres as the size of the building units ...
The dynamical signals of sound pressure oscillation in natural convective subcooled boiling system are obtained by using computer data acquisition technique. Through frequency-domain analysis of typical dynamical data, combined with study on the acquired time series of sound pressure, are observed and explained. The time-frequency phenomena, such as the onset of shock wave, frequency doubling relation of sound pressure, combination of sound frequency spectrum peaks etc., which describe the characteristics of natural convective subcooled boiling system are presented. Furthermore, based on frequency spectra of sound pressure, related eigen vectors are defined and established and with dynamical clustering method, regime recognition for the dynamical process of system is carried out. Results of recognition are consistent with that of qualitative analysis of time series, which is of great significance for ...
The objective of this project was to develop a explosion suppression system capable to confine and extinguish gas explosions of the type produced in sub level caving faces when blasting to the coal pillar. Existing systems, such as triggered barriers, were considered not to be valid because of size, weight, cost, and other operational constraints. The research activities have been focused in the development of a mixed water/air spray system that should be manually activated some second before blasting. Two prototypes have been developed and tested, the first one using nozzle operating at the standard ranges of pressure that are normally available in underground coal mines, and a second one based in high-pressure nozzles. In this case, bottles containing a pressurized air/water mixtures are required. The works carried out included theoretical studies, hydraulic nozzles characterization, and modelling of the explosion ...
The properties of polycrystalline (Ti, Al)N coatings deposited on non-nitrided, classically plasma-nitrided and low pressure plasma-nitrided AISI H11 steel samples were investigated. The plasma deposition and low pressure plasma nitriding were performed in a Z700-LH magnetron sputter ion plating unit, while a separate unit was used for plasma nitriding of specimens at a pressure of several millibars. The (Ti, Al)N coating was deposited onto all the samples using the same equipment as for the plasma deposition and low pressure plasma nitriding. For the characterization of the composite structures, the following methods were used: scratch test, X-ray diffraction analysis, scanning electron microscopy, scanning tunnelling microscopy and microhardness testing. It was found that plasma nitriding prior to coating deposition strongly affects the growth and properties of hard coatings, such as the ...
The effect of hydrostatic pressure applied at high temperature on photoluminescence of Si-implanted SiO_2 films was studied. A 'blue'-shift of PL spectrum from the SiO_2 films implanted with Si"+ ions to total dose of 1.2x10"1"7 cm"-"2 with increase in hydrostatic pressure was observed. For the films implanted with Si"+ions to a total dose of 4.8x10"1"6 cm"-"2 high temperature annealing under high hydrostatic pressure (12 kbar) causes a 'red'-shift of photoluminescence spectrum. The 'red' photoluminescence bands are attributed to Si nanocrystals while the 'blue' ones are related to Si nanocrystals of reduced size or chains of silicon atoms or Si-Si defects. A decrease in size of Si nanocluster occurs in result of the pressure-induced decrease in the diffusion of silicon atoms. (author)
Purpose: To evaluate the effect on dilatation of three types of covering materials used for endovascular stent-grafts.Methods: Stent-grafts with three types of covering material [0.1-mm polytetrafluoroethylene (PTFE), 0.2-mm PTFE, and 0.15-mm woven polyester] were placed in a fluid circuit. For the pulsatile pressure test, the luminal pressure of 190/130 mmHg was loaded up to 300,000 pulses. For the static pressure test, the luminal pressure was increased from 50 to 300 mmHg at 50-mmHg increments. The percent of dilatation of each stent-graft was compared.Results: The 0.1-mm PTFE stent-graft was significantly more dilated than the 0.2-mm PTFE and the 0.15-mm woven polyester stent-graft (p < 0.005) in both examinations. There was no significant difference between the 0.2-mm PTFE and the 0.15-mm woven polyester stent-grafts. The dilatation of the 0.1-mm PTFE stent-graft was irreversible.Conclusion: The ...
A study on development of magnetic drive packless valves for commercial purpose showed the results as follows; 1. Study on the radial rays effecting to the permanent magnets -Measurement of the strength of Nd-magnets according to irradiation of radial rays. 2. Effects of temperature on the magnetic driving device -Temperature dependency of the Nd-casting magnets. -Effects of temperature on the heat releasing fins of high-temperature valve. 3. Optimization of torque -Arranging method of permanent magnets -Measuring method and results of torque. 4. Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Calculation and design for the flat circular plates under pressure of the magnetic power transmitting device -Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Comparison of the characteristics between magnetic drive valve ...
The Institute of Gas Technology (IGT) has conducted a fundamental research program to determine the technical feasibility of a process concept that involves pressurized CO{sub 2}-coal gasification followed by a high-temperature CO{sub 2} removal step, using a MgO-based sorbent. To investigate a hot-CO{sub 2}-removal process, various MgO-containing materials were tested for their reactivity and capacity for removing CO{sub 2} from hot gas streams in a high-pressure thermobalance. No naturally-occurring materials were found to be acceptable, but a KOH-promoted magnesia was found to be sufficiently active for CO{sub 2} removal and to have a good capacity for CO{sub 2} absorption. Tests were conducted at pressures and temperatures in the ranges of 100--300 psig and 850{degree}--1170{degree}F. The CO{sub 2} absorption/desorption cycle was shown to be achievable by a simple pressure-swing operation between 0 ...
The theoretical and experimental investigation of the mechanism of SO2 and H2S removal by CaCO3 -based sorbents (limestones and dolomites) in pressurized uidized-bed coal combustors (PFBC) and high pressure gasiers, respectively, is the main objective of this study. It is planned to carry out reactivity evolution experiments under simulated high pressure conditions or in high pressure thermogravimetric and, if needed, uidized- bed reactor (high pressure) arrangements. The pore structure of fresh, heat-treated, and half-calcined solids (dolomites) will be analyzed using a variety of methods. Our work will focus on limestones and dolomites whose reaction with SO2 or H2S under atmospheric conditions has been studied by us or other research groups in past studies. Several theoret- ical tools will be employed to analyze the obtained experimental data including a variable diusivity ...
The Sulige gas field and the Yulin gas field are located in the north of the Ordos Basin. Reservoir pressure in the Sulige area is subnormal, whereas reservoirs in the Yulin area have normal hydrostatic pressure. This paper provides an explanation of this difference. The characteristics of reservoir sediment and formation water chemistry in the gas reservoirs of these two areas were analyzed. The results showed that both reservoirs have good sealing ability. Data of numerical simulation showed that tectonic uplift resulted in a great reduction in formation pressure in the northern Ordos Basin during the late Cretaceous period, and the decrease was greater in the Yulin gas field than in the Sulige gas field. However, because the total hydrocarbon-generating intensity of the Sulige area (< 24 x 10{sup 8} m{sup 3}/km{sup 2}) was less than that of the Yulin area (> 32 x 10{sup 8} m{sup 3}/km{sup 2}), the gas ...
Various kinds of decontaminations are carried out in atomic power plant. Here current decontamination technologies such as chemical decontamination with chemical solution or blast decontamination have a problem of reduction of secondary radioactive waste generated in the decontamination process. On the other hand, a low pressure arc plasma can remove metal oxide film on the metal substrate without heavy damage on the metal substrate when the object to be treated was set as a cathode. Dry surface decontamination technology with using low-pressure arc plasma can decrease secondary radioactive waste because low-pressure arc plasma does not need any chemical solution. In addition, the time required for treatment can be shorter, so it is possible for the low-pressure arc plasma decontamination technology to interpolate the current decontamination technologies such as spot decontamination technology etc. ...
Reinjection of spent geothermal brine is a common means of disposing of geothermal effluents and maintaining reservoir pressures. Contrary to the predictions of two-fluid models (two-viscosity) of nonisothermal injection, an increase of injectivity, with continued injection, is often observed. Injectivity enhancement and thermally-affected pressure transients are particularly apparent in short-term injection tests at the Los Azufres Geothermal Field, Mexico. During an injection test, it is not uncommon to observe that after an initial pressure increase, the pressure decreases with time. As this typically occurs far below the pressure at which hydraulic fracturing is expected, some other mechanism for increasing the near-bore permeability must explain the observed behavior. This paper focuses on calculating the magnitude of the near-bore permeability changes observed in several ...
A pump down model for a vacuum chamber with a reversibly adsorbed phase is presented. The outgassing equation which predicts the variation of coverage at the wall surface of a vacuum chamber with time is derived. Then the measured and the true outgassing rates are defined. The theoretical measured outgassing rate shows only a very weak dependence for pumping speed. This prediction is opposite to the experimental result that the measured outgassing rate depends significantly on pumping speed. It is discussed that the experimental measured outgassing rate must be described as the product of the effective pumping speed and the measured pressure in the pumped chamber, in which the measured pressure is equivalent to the equilibrium pressure of the wall surface described by the equilibrium adsorption isotherm as a function of the shifted surface coverage {theta}-{delta}{theta} by a small coverage {delta}{theta} from the coverage ...
Since some of the earliest evolutionary calculations it has been found that post main sequence stars become red giants (e.g. Sandage and Schwarzschild, 1952). However the exact physical processes that lead to and determine the rate of redward evolution are not completely understood. We hypothesized that the redward evolution might be due to an increase in radiation pressure somewhere in the star that causes the layers above it to be pushed outward, resulting in an expanded envelope and a cooler surface temperature. If the radiative luminosity somewhere in the star approached the Eddington limit, the outer layers would obviously expand. However, due to the presence of gas pressure, the critical value for expansion would be somewhat less than the Eddington limit.
The propagation of acoustic pressure perturbations in an adiabatic low-quality air/water flow were investigated both theoretically and experimentally. A linearized dispersion model is correlated with data to extract information on the behavior of interfacial momentum transfer controlled by the virtual volume coefficient. The dispersion model is examined in limiting cases of low and high frequency and related to current models for critical flow velocity. Fourier decomposition techniques are employed to predict the dispersion of measured pressure pulses and to relate data for standing waves and propagating pulses. The dispersion model is based on a two-fluid model and is the most complete model available in the literature at this time. The dispersion data presented herein is also the best available to date for low frequency (i.e., frequencies less than bubble resonance) sound propagation in bubbly air/water mixtures.
Several experimental runs have been carried out to study nucleate boiling of binary mixtures consisting of Freon-11 and lube oils such as SUNISO 3GS and 4GS in oil concentrations ranging from 0 to 24% by volume. The effect of the heating source temperature on the rate of boiling at various pressures has been studied and the boiling curves at different oil concentrations and pressures have been investigated at an excess temperature of up to 80/sup 0/C. The experimental data have been used to find the effect of pressure, oil concentration and excess temperature on the boiling heat transfer coefficient. The P-T relations for both kinds of mixtures have been measured at different oil concentrations. The heat lost to the atmosphere have also been studied as a function of oil concentration for both kinds of mixtures.
A metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments.
The cross-over from a magnetically ordered to a non-magnetic spin liquid state has been investigated in a series of resistance measurements under hydrostatic pressures of up to 30 kbar and at temperatures down to below 200 mK in the heavy fermion antiferromagnet CePd{sub 2}Si{sub 2}. The electrical resistivity changes dramatically with increasing pressure. Near the critical pressure, at which the magnetic ordering temperature is extrapolated to zero, it exhibits a quasi-linear variation over two orders of magnitude in temperature. This non-Fermi liquid form of {rho}(T) extends down to the onset of a new superconducting transition below 430 mK. (orig.).
The cross-over from a magnetically ordered to a non-magnetic spin liquid state has been investigated in a series of resistance measurements under hydrostatic pressures of up to 30 kbar and at temperatures down to below 200 mK in the heavy fermion antiferromagnet CePd_2Si_2. The electrical resistivity changes dramatically with increasing pressure. Near the critical pressure, at which the magnetic ordering temperature is extrapolated to zero, it exhibits a quasi-linear variation over two orders of magnitude in temperature. This non-Fermi liquid form of #rho#(T) extends down to the onset of a new superconducting transition below 430 mK. (orig.).
This invention is comprised of an improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as ...
The role of shear in determining the ideal MHD stability properties of tokamaks is discussed. In particular, we assess the effects of low shear within the plasma upon pressure-driven modes. The standard ballooning theory is shown to break down, as the shear is reduced and the growth rate is shown to be an oscillatory function of n, the toroidal mode number, treated as a continuous parameter. The oscillations are shown to depend on both the pressure and safety-factor profiles. When the shear is sufficiently weak, the oscillations can result in bands of unstable n values which are present even when the standard ballooning theory predicts complete stability. These instabilities are named ''infernal modes.'' The occurrence of these instabilities at integer n is shown to be a sensitive function of q-axis, raising the possibility of a sharp onset as plasma parameters evolve. 20 refs., 31 figs.
''Hybrid'' hydrogen storage, where hydrogen is stored in both the solid material and as a high pressure gas in the void volume of the tank can improve overall system efficiency by up to 50% compared to either compressed hydrogen or solid materials alone. Thermodynamically, high equilibrium hydrogen pressures in metal-hydrogen systems correspond to low enthalpies of hydrogen absorption-desorption. This decreases the calorimetric effects of the hydride formation-decomposition processes which can assist in achieving high rates of heat exchange during hydrogen loading-removing the bottleneck in achieving low charging times and improving overall hydrogen storage efficiency of large hydrogen stores. Two systems with hydrogenation enthalpies close to -20kJ/mol H2 were studied to investigate the h...
We demonstrate experimentally that the route to a jammed state for a set of bi-dispersed frictional disks, subjected to uni-axial compression from a random initial unjammed state, consists of a consolidation state, a fragile jammed state, and finally a rigid jammed state. In the consolidation regime, the pressure on the sides increases very slowly with the packing fraction {phi} and there are no detectable stress chains. In the fragile jammed state, stress chains are visible, the pressure increases exponentially with {phi}, and the fraction of moving disks drops exponentially. Eventually, a final regime where particle displacements are below our resolution and the pressure varies approximately linearly with {phi} is reached. We argue that this scenario is generic for ather mal frictional compressed particles.
The very low-pressure expansion tank of the title invention is connected to the water in the central heating installation via a connecting pipe with a pump and valves on one side, and on the other side the tank is connected via a connecting pipe with valve to the tap water mains, so that the supply of water can be regulated automatically. Within the expansion tank contact with the outside air is not possible because of an air/water separating floater. By means of recording and control (also remote) of the contents of the expansion tank, the installation pressure and the quantity of supplied water from the expansion tank and the tap water mains, failures and water damage are prevented. 4 figs.
Purpose: To obtain stabilized operation by preventing over heat in emergency cooling pumps upon accidents of flow regulators. Constitution: A pressure suppression chamber pool and a pressure vessel are communicated to each other with a pipeway and the water in the suppression pool is charged by a charging pump to the pipeway. The pipeway is interposed with an emergency cooling pump so as to feed water in the pipeway to the pressure vessel and a water source and the emergency cooling pumps are connected by way of a closed pipeway. Further, the closed pipeway and the pipeway interposed with the charging pump are communicated to each other by way of a connecting pipeway, to which are interposed an instrument for detecting the increase in the temperature of the emergency cooling pumps due to abnormality in the closed pipe (such as troubles in flow regulators) and outputting control signals and an electrically actuated valve ...
The scale-down of a liquid mini-pump (order of 10 mm) to a micrometre scale has been attempted using a novel valveless nozzle-diffuser design and new application of an organic physical vapor-deposited membrane. The micropump employs no moving parts other than the membrane and accomplishes the rectification of fluid flow due to pressure recovery differences in the nozzle and diffuser flow directions. More specifically, liquids flow with less resistance (i.e. conduct more fluid) in the diffuser direction than the nozzle direction, for a given pressure differential. At the micrometre scale, the fabrication of the critical nozzle and diffuser elements was performed by focused ion beam (FIB) microlithography of glass slides. Etched slides were sandwiched to make two-dimensional venturis. Sternme and Sternme noted the importance of a lower Reynolds Number linfit on the desired pressure recovery which challenged the fabrication of ...
Purpose: To remove excessive driving pressure applied to an unisolated control rod drive by returning excessive coolant to a condensed water storage tank or to the inlet side of a drive water pump using a coolant flow rate control pipe of a control rod driving hydraulic system. Constitution: Excessive water is returned to a condensed water tank while controlling the excessive coolant by a flow control valve in response to variations in the pressure difference between the reactor pressure and the driving water line when the control rods are isolated using a pipe from the outlet side of the drive water pump to the condensed water storage tank. Thus, the control rod to be isolated is prevented form being dropped. (Sekiya, K.).
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.
Regularities in the radiation cross-linking of low-density polyethylene under various conditions of ..gamma..-irradiation were studied. It is shown that at the 0.5 GPa pressure and 450 K the gel formation is initiated at doses of about 1 kGy, i.e. at doses 10 times as low as compared to normal conditions. Abnormally high rate of radiation cross-linking at high temperature and high pressure is an evidence of changes in the mechanism of polyethylene, radiation cross-linking, i.e. of the process transition from nonchain to chain conditions. Decrease in the potential barriers of macroradical reactions with macromolecules is the most probable reason of change in the polymer cross-linking nature.
As part of the EPRI Motor-Operated Valve (MOV) Performance Prediction Methodology, a System Flow Model (SFM) has been developed to determine the differential pressure (DP) across MOVs as they are stroked in typical power plant systems. Input to the SFM includes valve flow characteristics (such as flow coefficient) and system characteristics (such as pump head/flow curve). The primary output is differential pressure across the valve at each stroke position. The SFM was validated by comparison with test data from the EPRI Flow Loop Test Program. In this study, we calculated DP using SFM and performed DP test for four MOVs. Compared between calculated DP and test DP of four MOV, respectively good agreements are found. (author). 6 refs., 9 figs., 1 tab.