A full scale experiment was carried out to investigate the texture characteristics of the falling water of free falling and slope failing types. According to the increase of Reynolds number, the texture of falling water was classified into three categories for both types: stability of free surface, transition and whole turbulence. In the first category the stability of the free surface was related to the growth of minute disturbance. Surface tension works as a counter, force to the disturbance in free falling water, and gravity in slope falling water. 14 refs., 15 figs., 3 tabs.
In the Hokuriku area along the coast of the Japan Sea, thunderstorms often occurred not only in summer but also in winter, and this resulted in the shutdown of electricity supply or damage of equipment. This study was concerning the observation of the lightning channels in the Hokuriku area through a year by many still cameras equipped with liquid-crystal shutters. The following conclusions were obtained: Among 165 lightning incidents photographed during 2 years, there included 172 incidents of the falling thunderstorms and 23 incidents of simultaneously falling thunderstorms at multi-area. In the case of winter, frequency to occur simultaneously falling thunderstorms at multi-area was higher and the upward falling thunderstorms were more. There was a tendency that the duration time of the lightning current in winter was longer than in summer. In winter, frequency to occur the upward ...
The average angle of repose and the packing density of random planar heaps of hard disks falling ballistically onto a sticky base line, where the first layer of disks is quenched in random positions, are computed for heaps with a small fixed number of gaps in the base layer. The results we find appear to be almost independent of the size of the heap and they agree with those obtained from computer simulations of large systems.
Using data on libraries collected by the Association of Research Libraries (ARL) and the Association of College and Research Libraries (ACRL), as well as fall-to-fall retention rates obtained from the Integrated Postsecondary Education Data System (IPEDS) of the National Center for Education Statistics (NCES), this study employs statistical measures of association to analyze the relationship of both library expenditures and number of professional library staff to student persistence. The strongest relationships found were those between student retention and total library expenditures, total library materials costs, and serial costs for institutions categorized as baccalaureate colleges within the Carnegie Classification System. The most significant relationship between persistence and numb...
Fisheries co-managers of U.S. v Oregon supported and directed the construction and operation of acclimation and release facilities for Snake River fall Chinook from Lyons Ferry Hatchery at three sites above Lower Granite Dam. In 1996, Congress instructed the U.S. Army Corps of Engineers (USCOE) to construct, under the Lower Snake River Compensation Plan (LSRCP), final rearing and acclimation facilities for fall Chinook in the Snake River basin to complement their activities and efforts in compensating for fish lost due to construction of the lower Snake River dams. The Nez Perce Tribe (NPT) played a key role in securing funding and selecting acclimation sites, then assumed responsibility for operation and maintenance of the facilities. In 1997, Bonneville Power Administrative (BPA) was directed to fund operations and maintenance (O&M) for the facilities. Two acclimation facilities, Captain John Rapids and Pittsburg Landing, are located ...
A theory for the mass transfer process was developed. It was assumed that the largest convective motions in the flow control the rate of mass transfer. Measurements of mass transfer coefficients for the absorption of oxygen by water films were made for concurrent flows in a horizontal rectangular channel, and for concurrent and free-falling downflow in a one-inch pipe. The measured values of the Sherwood number for concurrent flows were up to three times as great as would be predicted from this relation. This increase in Sherwood number was correlated with a dimensionless group similar to a Martinelli parameter which is characteristic of two phase flows. An explanation for this effect is given in terms of the way that the scales of the convective motions are related to bulk flow parameters.
OBJECTIVESAlthough several studies suggest that slow gait speed is a predictor of falls, it may also be a protective mechanism to prevent falls. Further, fast walking...Full Text Available
This paper is concerned with the real time automatic discriminating of flaws from two categories; i. cracks (planar defect) and ii. Non-cracks (volumetric defect such as cluster porosity and slag) using pulse-echo ultrasound. The raw ultrasonic flaws signal were collected from a computerized robotic plane scanning system over the whole of each reflector as the primary source of data. The signal is then filtered and the analysis in both time and frequency domain were executed to obtain the selected feature. The real time feature analysis techniques measured the number of peaks, maximum index, pulse duration, rise time and fall time. The obtained features could be used to distinguish between quantitatively classified flaws by using various tools in artificial intelligence such as neural networks. The proposed algorithm and complete system were implemented in a computer software developed using Microsoft Visual BASIC 6.0 (author)
This paper addresses the problem of partitioning a local service region into nonoverlapping work areas in which pickups and deliveries are made throughout the day. For a fleet of homogeneous vehicles, a given set of customers, and expected demand for service, the objective is to find the least number of work areas or clusters that satisfy a variety of geometric and capacity constraints. Using rectangles as the basic shape, each cluster must have an aspect ratio that falls within certain bounds, as well as meet load and time requirements dictated by the capacity of a vehicle and the working hours in a day, respectively. The latter requirement presents a unique hurdle because travel times are a function of the actual routes followed by the drivers, and are not known, even in a probabilistic ...
Pregnant Swiss albino mice of 18 days post conception were exposed to 0.80 Gy, 0.40 Gy and 0.20 Gy of gamma rays from a Cobalt-60 source at different dose rates (.0584 Gy/min and .00091 Gy/min). Post irradiation variations in the cell population of crypts and villus of jejunum were studied in the F_1-generation at 1 day, 3 day and 1,2,4,6 and 12 weeks of post-partum age. In all the exposure groups at 1 day post-partum age, crypts show a decrease in total cells, mitotic figures and goblet cells on one hand and an increase in PNNC on the other hand in comparison to coeval controls. At this interval a decrease in the number of total cells as well as goblet cells/villus column was also noticeable. Dead cells which were prominently seen in crypts were totally absent in villi. The first signs of recovery can be observed on day 3 p.p. when total cell population, mitotic activity and goblet cells of crypt registered an increase while percentage of PNNC showed a ...
Background:Falls have been identified as a potential adverse event associated with the administration of psychotropic medications to older patients.Objective:The...Full Text Available
... the vertical beam measures the movement of the ... be measured because the particle velocity in ... During precipitation, if the hydrometeor fall velocity is ...
We describe an efficient procedure for proving stabilization of biological systems modeled as qualitative networks or genetic regulatory networks. For scalability, our procedure uses modular proof techniques, where state-space exploration is applied only locally to small pieces of the system rather than the entire system as a whole. Our procedure exploits the observation that, in practice, the form of modular proofs can be restricted to a very limited set. For completeness, our technique falls back on a non-compositional counterexample search. Using our new procedure, we have solved a number of challenging published examples, including: a 3-D model of the mammalian epidermis; a model of metabolic networks operating in type-2 diabetes; a model of fate determination of vulval precursor cells in the C. elegans worm; and a model of pair-rule regulation during segmentation in the Drosophila embryo. Our results show many orders of magnitude speedup ...
This study was initiated to provide empirical data and analyses on the dam passage timing, travel rate, survival, and life history variation of fall Chinook salmon that are produced in the Clearwater River. The area of interest for this study focuses on the lower four miles of the Clearwater River and its confluence with the Snake River because this is an area where many fish delay their seaward migration. The goal of the project is to increase our understanding of the environmental and biological factors that affect juvenile life history of fall Chinook salmon in the Clearwater River. The following summaries are provided for each of the individual chapters in this report.
...225J Einstein, Oppenheimer, Feynman: Physics in the 20th Century Fall 2002 8.231 Physics of Solids I Fall 2002 8.251 String Theory for Undergraduates Spring 2003 8.261J Introduction to Computational Neuroscience Spring 2002 8.282J Introduction to Astronomy Spring 2003 8.321 Quantum Theory I Fall 2002 8.322 Quantum Theory II Spring 2003 8.323 Relativistic Quantum Field Theory I Spring 2003 8.324 Quantum Field Theory II ...
The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach of the Columbia River. The evaluation, in the fifth year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fishes, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 2001 field season.
The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the fourth year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fishes, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 2000 field season.
The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the third year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fishes, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 1999 field season.
The Washington Department of Fish and Wildlife (WDFW) has been contracted through the Bonneville Power Administration (BPA) and the Grant County Public Utility District (GCPUD) to perform an evaluation of juvenile fall chinook salmon (Oncorhynchus tshawytscha) stranding on the Hanford Reach. The evaluation, in the second year of a multi-year study, has been developed to assess the impacts of water fluctuations from Priest Rapids Dam on rearing juvenile fall chinook salmon, other fish species, and benthic macroinvertebrates of the Hanford Reach. This document provides the results of the 1998 field season.
... water content according to the hydrometeor type. ... the documentation and the movement personnel and ... Dyer, RM, 1970: Particle fall speeds within ...
... rivers of the world, the Zaire is not an efficient transportation link because of many rapids and falls to negotiate between Kinshasa and the port city of Matadi. ...
ObjectiveThis study investigated transitions between drinking and nondrinking during the first 12 months following treatment and whether transitions in posttreatment...Full Text Available
HYPSOGRAPHY FOR THE FOLLOWING QUADS ALEXANDRIA, FALLS CHURCH, WASHINGTON WEST, MOUNT VERNON, ROCKVILLE, SENECA AND VIENNA. COVERAGE CONTAINS ATTRIBUTES DEFINING OWNERSHIP....
This chapter will review the literature on cobalamin- and corrinoid-containing enzymes. These enzymes fall into two broad classes, those using methylcobalamin or related methylcorrinoids as...Full Text Available
Studies were conducted to describe current habitat conditions in the White River basin above White River Falls and to evaluate the potential to produce anadromous fish. An inventory of spawning and rearing habitats, irrigation diversions, and enhancement opportunities for anadromous fish in the White River drainage was conducted. Survival of juvenile fish at White River Falls was estimated by releasing juvenile chinook and steelhead above the falls during high and low flow periods and recapturing them below the falls in 1983 and 1984. Four alternatives to provide upstream passage for adult salmon and steelhead were developd to a predesign level. The cost of adult passage and the estimated run size of anadromous fish were used to determine the benefit/cost of the preferred alternative. Possible effects of the introduction of anadromous fish on resident fish and on nearby Oak Springs Hatchery were ...
Stereotactic radiosurgery (SRS) precisely delivers high-dose radiation to a small target (usually less than 3-4 cm in diameter), in a single session with steep dose-fall, employing various radiation methods. SRS provides good tumor control for small brain metastases from various primary cancers, with minimal untoward effects on surrounding normal brain. This excellent tumor control prevents neurological death and maintains good activity of daily life. Although surgery with whole-brain radiation therapy (WBRT) remains an important option for patients with a solitary brain metastasis, SRS with or without WBRT should be considered in patients with a limited number of small tumors and a good prognosis. Many reports, as well as both retrospective and prospective reviews, have shown WBRT before or after SRS to improve local control and reduce new distant lesion emergence. However, upfront WBRT does not improve survival. There are two major delivery ...
The Monte Carlo method is used to analyse the dose fall-off at the exit surface of a megavoltage photon beam. The convolution/superposition method of dose calculation using Monte-Carlo-generated homogeneous photon kernels is shown to be in error for exit dose calculation. Instead, photon kernels that incorporate modelling of the exit surface were generated, also using Monte Carlo, to analyse the problem, and the calculated dose fall-off using these kernels agrees well with measured data. In addition, the physics underlying the characteristics of the dose fall-off is analysed based on complete Monte Carlo modelling. Practical improvements to the convolution/superposition method are suggested. (Author).
It is shown that the usual proof of the second law of black hole physics breaks down if there are tachyons present in the vicinity of a black hole. Explicit cases are discussed where a tachyon of positive energy falling into the Kerr singularity actually decreases the area of the Kerr black hole. (author).
Since membrane structures such as domes have been constructed in snowy regions, how to dispose snow on the roof has become a big problem. In the case of disposing snow on the roof by sliding off, it is required to know the distance and range of snow dispersion after the fall from the roof from the aspect of disaster prevention. This paper describes the experimental study on the effects of snow depth, sliding distance and angle on the distance and range of snow dispersion using an outdoor apparatus to slide the snow off which can adjust the conditions for sliding. As a result, the distance of snow dispersion was influenced not only by the sliding distance and angle but also the depth (as well as the weight) of the snow. When the snow was sliding on the membrane structure, it was neccesary to consider viscostic resisting force of water between the snow and the membrane in addition to kinetic friction force. After the fall from the roof, the ...
alpha-actinins are actin microfilament crosslinking proteins. Vertebrate actinins fall into two classes: the broadly-expressed actinins 1 and 4 (actn1 and actn4)...Full Text Available
Diseases of man caused by the virus of herpes simplex fall into two broad categories. The primary disease occurs only once in any individual's life and is caused by transmission of virus from an already...Full Text Available
The discussion of energy usage falls naturally into three parts. The first is a review of what the problem is, the second is a description of steps that can be taken to conserve energy at existing facilities, and the third is a review of the implications of energy consumption on future facilities.
Emissions of sulphur and nitrogen oxides are continuing to fall in Europe but rise in Asia, according to calculations based on individual countries' predictions of economic development. The upward trend is slower than in previous predictions. 2 refs., 2 figs., 2 tabs.
The torque-velocity relationship is known to be affected by ageing, decreasing its protective role in the prevention of falls. Interindividual variability in this torque-velocity relationship is partly...Full Text Available
Severance of the ureter beyond the renal papilla causes a fall in urinary osmolality, which suggests that exchange of water or solute between urine and renal parenchyma normally occurs in the intact...Full Text Available
BackgroundDiet is considered an important factor for bone health, but is composed of a wide variety of foods containing complex combinations of nutrients. Therefore we investigated...Full Text Available
... 45 SW Staff and NASA on movement, intensity, weather conditions, ...... a) All surfaces of the vehicle susceptible to precipitation particle impact have been ... hydrometeors falling through the 0 deg C level and beginning to melt. ...
On the problem of alarm when parts are falling in nuclear power plant, the artificial neural network (ANN) alarm method based on the signal time-frequency characteristics was developed. The method was realized by the improved BP algorithm, and demonstrated with the data from simulation experiments
Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.
Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.
A rigorous mathematical model is developed to describe chemical absorption of carbon dioxide in a falling-film micro-contactor. Contrary to previous models described in literature, hydrodynamics in both phases is accurately captured by the Navier-Stokes equations. By this means, backmixing effects can be accounted for. Furthermore, the interface position is determined directly using the level-set method. The developed model is validated with experimental data obtained from literature and a good agreement is established. With the validated model, detailed studies are performed to investigate the impact of process parameters.
Given a Schwarzschild black-hole, the frame sigma at rest with respect to the Schwarzschild metric are chosen as reference-frames. In this locally non-inertial frames, a free falling body is shown to reach the speed of light on the horizon and then to travel faster-than-light inside the horizon. The usual Szekeres-Kruskal (SK) coordinates represent themselves frames that (with respect to the frames sigma) travel at subliminal speed outside, at luminal speed on, and at superluminal speed inside the horizon (so that SK frames always describe any free falling body as a standard, slower-than-light object). At last, black-holes are shown to be possible sources of tachyons.
The Control Rod Drive(CRD) nozzles for PWR nuclear power plants(NPP) house the control rod drives. The number of nozzle penetrations range from the mid-30's to over 100 in each reactor head. The integrity of CRD nozzles is very important, because the primary pressure boundary is established with the J-groove weld joining the nozzle to the head clad surface. The Alloy 600 PWSC CRD nozzle leaks discovered in the fall of 2000 and spring of 2001 in several US plants. Therefore the NRC has recommended a more proactive effort by US utilities to inspect similarly susceptible nozzles in all US plants. The primary safety concern is circumferential cracks that can permit the nozzles to separate from the head at high velocity and produce a large-break leak in the reactor vessel. A secondary concern is head leakage from any through-wall cracks in the nozzle or J-groove weld area. Numerous inspection and repair tools have been developed to address ...
A possible receiver configuration is a cavity in which a falling sheet of solid particles is directly irradiated by the concentrated solar flux passing through the aperture. Regardless of the particular geometry, the radiative transfer within the falling particle curtain must be studied in order to determine the net radiative heating rate for the particles. A discrete ordinate radiative transfer model has been developed to predict the radiative coupling within the falling particle curtain. The model determines how much energy is absorbed by the particles, how much is transmitted to the rear wall of the receiver, and determines the effects of particle scattering and thermal emission on the net radiation absorbed by the particles. The model accounts for the directional nature of the radiation field, particle scattering, and the wavelength dependence of the optical properties. The discrete ordinate model has been used to ...
A voice-tracking algorithm was developed and tested for the purposes of electronically separating the voice signals of simultaneous talkers. Many individuals suffer from hearing disorders that often inhibit their ability to focus on a single speaker in a multiple speaker environment (the cocktail party effect). Digital hearing aid technology makes it possible to implement complex algorithms for speech processing in both the time and frequency domains. In this work, an average magnitude difference function (AMDF) was performed on mixed voice signals in order to determine the fundamental frequencies present in the signals. A time prediction neural network was trained to recognize normal human voice inflection patterns, including rising, falling, rising-falling, and falling-rising patterns. The neural network was designed to track the fundamental frequency of a single talker based on the training procedure. The output of the ...
The Idaho Falls quadrangle in southeastern Idaho lies at the juncture of the Snake River Plain, the Northern Rocky Mountains, and the Basin-Range Province. Quaternary basalts of the Snake River Plain occupy 70% of the quadrangle. The rest of the area is covered by uplifted Paleozoic, Mesozoic, and Cenozoic rocks of the Pre-Late Cenozoic Orogenic Complex. Magnetic data apparently show contributions from both shallow and deep sources. The apparent expression of intrusive and extrusive rocks of late Mesozoic and Cenozoic age tends to mask the underlying structural downtrap thought to exist under the Snake River Plain. The Idaho Falls quadrangle has been unproductive in terms of uranium mining. A single claim exists in the Sawtooth Mountains, but no information was found concerning its present status at the time of this study. A total of 169 anomalies are valid according to the criteria set forth in Volume I of this report. These anomalies are ...
Further improvement of dimensional tolerance and elimination of such post-processing as cutting work are required for the maximum exhibition of the features of sintered parts. Powder behavior in fall filling and leveling off is observed with the prototype of visual apparatus for observing powder filling. It is found that the delay in the replacement of powder by air in the die and the fall along the angle of repose are the causes for the occurrence of particle size segregation, and that the diagonal downward slide of powder in upper layer only in leveling off is the cause for nonuniformity of the density. As a result, it is found that improvement of powder flowability and minimization of shaking are important for uniform and rapid filling of powder in a thin walled and complicated shape die cavity, and a guide for developing uniform filling method is made clear. Based on the result, a new uniform filling method for powder is under development ...
Remotely sensed ocean color data and numerical modeling have been used to study the phenology of both spring and fall phytoplankton blooms (FPBs) in the Nova Scotian Shelf (NSS)-Gulf of Maine (GoM) region. The ocean color data reveal a general pattern of westward progression of the spring phytoplankton bloom (SPB), and an eastward progression of the FPB in the NSS-GoM region. The spatial pattern of mean chlorophyll concentration in spring is similar to that in fall, with a lower concentration in the NSS and higher in the GoM. Interannually, there is a weak but significant tendency for years with earlier (delayed) SPBs to be followed by delayed (earlier) FPBs, but the mean chlorophyll concentrations during SPBs are not correlated with those during FPBs. The interannual variability of SPB ti...
Numerous studies have shown that large, herbivorous waterfowl can reduce quantity of aquatic plants during the breeding or wintering season, but relatively few document herbivory effects at staging areas. This study was done to determine if feeding activities of tundra swans (Cygnus columbianus columbianus) and Canada geese (Branta canadensis) had a measurable additive influence on the amount of aquatic plants, primarily muskgrass (Chara vulgaris), wild celery (Vallisneria americana), and sago pondweed (Potamogeton pectinatus), removed during the fall migration period at Long Point, Lake Erie, Ontario. Exclosure experiments done in fall 1998 and 1999 showed that, as compared to ducks and abiotic factors, these two large herbivorous waterfowl did not have any additional impact on above or b...
This article comments on the fact that there are only 17 energy-from-waste installations in operation in the U.S. and in this respect it lags behind other industrialized nations. Explanations for this gap include the relatively inexpensive garbage disposal as landfill, operating difficulties of some early plants and the high cost of building such facilities. There has been a recent push to build resource-recovery plants and it is believed that chemical companies will probably buy energy products from such plants. Hooker Chemical Co's new energy-from-waste plant at Niagra Falls, N.Y. is described, other companies involved in resource-recovery projects are mentioned, and it is hoped that more companies will invest in such plants.
The decrease and subsequent lack of recovery of the North American scaup population has increased concerns about contaminants acquired during migration. We collected 189 fall- and spring-migrant lesser (Aythya affinis) and greater scaup (A. marila) on the lower Great Lakes (LGL) to determine if organic contaminants and trace elements in scaup livers were increased and to evaluate sources of variation in selenium (Se) burdens. We found that all organic contaminants were below toxic levels. Of 18 trace elements, only Se was detected at increased (>10-ppm dry-mass) levels. Se in lesser scaup increased but remained constant in greater scaup throughout fall; levels were increased in 14% of lesser scaup and 46% of greater scaup. During spring, Se increased in lesser scaup but decreased slightly ...
Biostimulation by nutrient application is a viable technology for restoring oil-contaminated beaches. Maximizing the nutrient residence time is key for achieving a rapid cost-effective cleanup. We considered the nutrient injection strategy through a perforated pipe at the high tide line and we simulated numerically beach hydraulics, which allowed us to estimate the optimal injection flow rate of nutrient solution. Our results indicate that the optimal application is one that starts following the falling high tide and lasts for half tidal cycle. The saturated wet-front of the nutrient solution on the beach surface would move seaward with the same speed of the falling tide keeping a constant distance with the tide line. The numerical results were generalized to beaches of wide ranges of hydr...
One mitigation goal of the Hungry Horse Dam fisheries mitigation program, funded by the Bonneville Power Administration, is to replace lost production of 100,000 adult kokanee in Flathead Lake. The mitigation program calls for a five-year test to determine if kokanee can be reestablished in Flathead Lake. The test consists. of annual stocking of one million hatchery-raised yearling kokanee. There are three benchmarks for judging the success of the kokanee reintroduction effort: (1) Post-stocking survival of 30 percent of planted kokanee one year after stocking; (2) Yearling to adult survival of 10 percent (100,000 adult salmon); (3) Annual kokanee harvest of 50,000 or more fish per year by 1998, with an average length of 11 inches or longer for harvested fish, and fishing pressure of 100,000 angler hours or more. Kokanee were the primary sport fish species in the Flathead Lake fishery in the early 1900s, and up until the late 1980s when the population rapidly declined in ...
Sprat Sprat in the Southwestern Baltic Sea (including Sound and Belt Sea) ...episodic salt water inflows which occur during autumn to spring.The last major inflow to the Baltic Proper ...The small inflows in spring 1986 and fall 1988 have had only effects on salinity and temperature
DescriptionMeasurements of halocarbons (CFCs and other halogen-containing compounds) in the tropical stratosphere will be made from a long duration MIR balloon. The balloon and instruments are capable of flying for three or more weeks in which time they will circum-navigate the globe. As the balloon rises each morning and falls each evening, measurements of halocarbons will be made every few hundred meters between about 20 and 30 km. In total it is hoped that over 40 such vertical profiles will be obtained [continued...
The motion of a test particle moving in an interior static spherically symmetric geometry is investigated. The author concludes that an oscillatory motion with the test particle changing its motion from a free fall towards the center to an outward radial motion can not exist for any static interior spherically symmetric model.
BackgroundMany emergency ambulance calls are for older people who have fallen. As half of them are left at home, a community-based response may often be more appropriate than hospital...Full Text Available
Corn stover is typically left behind in the field after grain harvest. Although part of the stover should remain in the field for soil organic matter renewal and erosion protection, half of the stover could be removed sustainably. This represents about one million t dry matter (DM) of stover per year in the province of Quebec. Stover harvested in the fall is very wet. While there are applications for wet stover, the available markets currently require a dry product. Preliminary measurements have shown that stover left in the field throughout the winter becomes very dry, and a considerable amount would still be harvestable in the spring. In the spring of 2009, corn stover was harvested at 2 sites, each subdivided into 2 parcels. The first parcel was cut and raked in the fall of 2008 (fall parcel), while the second parcel was cut and raked in spring 2009. Fibre from both parcels was baled in the spring 2009. At the first ...
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.
A quadruply redundant synchronous fault tolerant processor (FTP) is now under fabrication at the C.S. Draper Laboratory to be used initially as a trip monitor for the Experimental Breeder Reactor EBR-II operated by the Argonne National Laboratory in Idaho Falls, Idaho. The real time operating system for this processor is described.
A study is made of the mechanical properties of vanadium irradiated with fast neutrons up to dose 8.6.10"-"4 dpa, as a function of the temperature of post-radiation annealing. The radiation-annealing hardening (RAH) effect is observed at 300"oC, in agreement with previous studies. It is established for the first time that RAH is accompanied by fall in ductility. A phenomenological model is described which explains the dependence of RAH on radiation dose and temperature, as well as on the content of chemically active alloying impurities. (author).
Biological motors generally fall into two categories: (1) those that convert chemical into mechanical energy via hydrolysis of a nucleoside triphosphate, usually adenosine triphosphate, regarded as life's chemical currency of energy and (2) membrane bound motors driven directly by an ion gradient and/or membrane potential. Here we argue that electrostatic interactions play a vital role for both types of motors and, therefore, the tools of physics can greatly contribute to understanding biological motors.
An overview of emissive display technologies is presented. Display types briefly described include: cathode ray tubes (CRTs), field emission displays (FEDs), electroluminescent displays (ELDs), and plasma display panels (PDPs). The critical role of phosphors in further development of the latter three flat panel emissive display technologies is outlined. The need for stable, efficient red, green, and blue phosphors for RGB fall color displays is emphasized.
Eastern Oregon cattle distribution was studied with global positioning (GPS) collars for 2 years on the Zumwalt prairie in the spring and fall and Hells Canyon during the winter to determine distribution and habitat selection differences between Spanish bred (Corriente X Longhorn) and English bred c...
It is shown that observations of the lithium isotope ratio in high surface temperature Population II stars may be critical to cosmological nucleosynthesis models. In particular, decaying particle scenarios as derived in some supersymmetric models may stand or fall with such observations. 18 references.
The development of electric cars always met with the difficulty in storing energy and in recovering it in the form of electric power. Research work done for the last two decades in the field of materials and of new technologies oriented mainly towards aeronautical and space applications have led to designing, realizing and experimenting with flywheels rotating at high speed in magnetic bearings. The results obtained represent openings that, now, fall in with different industrial fields and in particular with application to electric cars.
This paper reports that Sen. Bennett Johnston (D-La.) has vowed if Congress enacts an omnibus energy bill in the fall, it will not include a restriction on states' rights to proration natural gas production. Johnston, Senate energy committee chairman, will lead Senate conferees in their negotiations with members of the House of Representatives. The House energy bill has an antiproration amendment. The Senate's bill does not. Oklahoma's and Texas' recent actions to proration gas production prompted the federal legislation.
Evaluation procedures used to produce sets of evaluated data for the 33 heavy isotopes that fall in the range Z = 90 to Z = 98 are described. At the beginning of the discussion for each individual isotope, a computer-generated listing is given which summarizes the main properties of the data sets that are contained in the evaluation. (RWR)
The report describes tests to demonstrate the feasibility of using a vertical-tube, falling-film, vapor-compression evaporator to concentrate waste water from a flue gas desulfurization (FGD) process. Tests showed that waste water from the Chiyoda FGD process can be concentrated ...
In recent years the 'Nowcasting Wake Vortex Impact Variables' model NOWVIV has been developed at the Deutsches Zentrum fuer Luft- und Raumfahrt, DLR, to forecast weather parameters in airport environments. The German Meteorological Service, DWD, employs his COSMO-DE model (COnsortium for Small scale Modelling-DEutschland) for operational forecasts in Germany. A systematic comparison of model output from NOWVIV and a derivate of COSMO-DE, named COSMO-FRA, is presented. Both models are centred at Frankfurt Airport with horizontal resolutions of 2.1 km and 2.8 km, respectively. In the DLR Project Wetter and Fliegen the COSMO-FRA model will replace the NOWVIV model and become a key component in the future rapid update cycle for adverse weather predictions at the airports of Frankfurt and Munich. The forecast vertical profiles of runway crosswind, head/tail wind, temperature, and turbulent kinetic energy (TKE) are validated against Wind and Temperature Radar (WTR/RASS) ...
... Hale, Markku Kulmala, 373.43 EUR; 225.00 USD; 276.00 GBP... More Journals » MAGAZINES & JOURNALS Journal of Water Supply: Research &Technology -... Journal of Water Supply: Research and Technolog... Environmental Quarterly - 2009 Fall Trinity`s Environmental Quarterly (EQ) magazine co... ...
... Boreal Forest and Climate Change Pertti Hari, Liisa Kulmala, 160.45 EUR; 209.00 USD; 135.00 GBP... More Journals » MAGAZINES & JOURNALS Journal of Water and Health The journal represents a joint commitment to pr... Environmental Quarterly - 2009 Fall Trinity`s Environmental Quarterly (EQ) magazine co... ...
Nutrient elements contained in litter fall flux, that of uptake flux and turnover rate had generally tended to increase with the increase in the Warmth Index, while the amount of nutrient in the A[sub 0] horizon and nutrient use efficiency did not. However, it is suggested that topographic and climatic aridity, and the amount of available and exchangeable phosphorus, calcium and magnesium greatly affect the nutrient dynamics in a each forest ecosystem as the Warmth Index increases. (J.P.N.).
Asymptotic estimates for the typical number of irreducible coverings and the typical length of an irreducible covering of a Boolean matrix are obtained in the case when the number of rows is no less than the number of columns. As a consequence, asymptotic estimates are obtained for the typical number of maximal conjunctions and the typical rank of a maximal conjunction of a monotone Boolean function of variables defined by a conjunctive normal form of clauses. Similar estimates are given for the number of irredundant coverings and the length of an irredundant covering of an integer matrix (for the number of maximal conjunctions and the rank of a maximal conjunction of a two-valued logical function defined by its zero set). Results obtained previously in this area are overviewed.
We present the results of an isophotal shape analysis of three samples of galaxies in the Coma cluster. Quantitative morphology, together with structural and photometric parameters, is given for each galaxy. Special emphasis has been placed on the detailed classification of early-type galaxies. The three samples are: i) a sample of 97 early-type galaxies brighter than m_B = 17.00 falling within one degree from the center of the Coma cluster; these galaxies were observed with CCD cameras, mostly in good to excellent resolution conditions; ii) a magnitude complete sample of 107 galaxies of all morphological types down to m_B = 17.00 falling in a circular region of 50 arcmin diameter, slightly offcentered to the North-West of the cluster center; the images for this and the next sample come from digitized photographic plates; iii) a complete comparison sample of 26 galaxies of all morphological types down to m_R = 16.05 (or m_B \\simeq 17.5), also ...
Machines and structures, such as automobiles are usually subjected to biaxial or three-axial stresses instead of uniaxial stress. However, research on a fatigue failure under multi-axial stress has not been fully presented because such experiments are difficult. To solve this problem, we developed the servo biaxial fatigue-testing machine. In this research, we performed the biaxial fatigue tests of a magnesium alloy in order to clarify the effects from different heat treatments. Magnesium alloy is the lightest in weight among metal materials for structural use. The fatigue characteristics of a magnesium alloy are indispensable in order to create the design which ensures the reliability and the safety of the vehicles especially in long-distance run. The main conclusions are summarized as follows; (1) The mechanical property of magnesium alloy AZ31B falls by heat treatment at low temperature. (2) The crack progress speed becomes quick by the fall ...
Presently no one knows whether electromagnetic fields (EMFs) play a role in human cancer or other ailments, though epidemiological studies over the years have suggested that possibility. A study by the Electric Power Research Institute attempted to quantify everything it could about the magnetic environment of a home, identifying not only major sources of magnetic fields, but also their frequencies, strengths, and how they fall off with distance. Sources of a homes magnetic environment include appliances, overhead powerlines, and grounding connections to metallic water pipes. Fields will vary over time, depending on how much current is passing through the electrically conductive sources. Additional contributors to a home's magnetic background may include unusual wiring in the walls, underground power lines, and near-by high voltage transmission lines. This paper summarizes the study results, indicating weak, persistant EMFs may dominate, but small magnetic field ...
Two US DOE projects in the Pacific Northwest offer unique on-the-scene training opportunities at sodium-cooled fast-reactor plants: the Fast Flux Test Facility (FFTF) near Richland, Washington, which has operated successfully in a wide range of irradiation test programs since 1980; and the Experimental Breeder Reactor II (EBR-II) near Idaho Falls, Idaho, which has been in operation for approximately 20 years. Training programs have been especially designed to take advantage of this plant experience. Available courses are described.
Industrial activities in the river basin of the Elbe have a very long tradition, and have been resulting in the contamination of sediments for centuries. Contamination lasted until the fall of the iron curtain; since then, the situation has improved significantly. In the transition zone between freshwater systems and the marine environment, ports like Hamburg still have to bear this burden of history. An overall (contaminated) management strategy should be developed in the context of the European Water Framework Directive with the emphasis on source control. (orig.)
When decontaminated with continuously replenished CAN-DECON reagent in a once-through system, carbon steel contaminated with "6"0Co during exposure to reducing coolant in stainless steel loops loses up to 90 percent of its radioactivity in the first few minutes. Afterwards, the rate of removal falls to much lower values which persist for many hours to the end of the experiment. The effects of flow rate, temperature and reagent concentration on the initial rates of decontamination indicate that mass transfer in the liquid is an important factor in the decontamination. The decontamination factor is influenced by the initial rate.
Although rovs (remotely operated vehicles) and AUVs (autonomous underwater vehicles) are playing ever increasing roles in the development of underwater fields, surprise is expressed that oil companies are not supporting the necessary research and development. The situation was discussed at this year's annual Association of Diving Contractors and Marine Technology Society in Houston. Some of the technical problems associated with operating the vehicles in deeper and deeper water were discussed. Although demand for the vehicles is falling in the North Sea, the Gulf of Mexico is seen as the next growth area. (uk)
This study reconceptualizes the native/nonnative dichotomy and provides a powerful lens to examine linguistic identities. In a study of 25 linguistically diverse teacher candidates in Canada, the respondents' native and nonnative self-ascription and self-assessed level of proficiency was juxtaposed with the judgment of their instructors. This process revealed that the native/nonnative dichotomy falls short in capturing the multifaceted nature of individuals' diverse linguistic identities and tends to misrepresent them. Within the specific social context under investigation, 6 linguistic categories that better represented the true linguistic identity of participants were identified. This inquiry reconceptualizes the controversial native/nonnative dichotomy by suggesting that linguistic iden...
An accelerator has limited dynamic range: a chain of accelerators is required to reach high energy. A combination of septa and kicker magnets is frequently used to inject and extract beam from each stage. The kicker magnets typically produce rectangular field pulses with fast rise- and/or fall-times, however the field strength is relatively low. To compensate for their relatively low field strength, the kicker magnets are generally combined with electromagnetic septa. The septa provide relatively strong field strength but are either DC or slow pulsed. This paper discusses injection and extraction systems with particular emphasis on the hardware required for the septa.
The present invention is a device for a solar heating system having a solar collector, a storage tank connected to the solar collector, a pump for circulating liquid from the tank to the solar collector, a supply of liquid at a temperature above freezing and a connection from the supply of liquid to the solar collector for replacing any liquid lost from said solar collector. The device comprises a sensor for sensing the temperature of liquid in the solar collector, and a valve for bleeding liquid from the solar collector when the sensed temperature falls below a predetermined minimum whereby cool liquid in the solar collector is automatically replaced by liquid at a temperature above freezing.
This report describes the activities conducted with DOE funds at Oregon Health Sciences University between 9/15/94 and 9/29/99. The activities fall into four major categories: Information Technology, Information Services and Support, Medical Informatics and Outcomes Research, and collaboration with other institutions. The focus of these activities was to implement and maintain a regional healthcare information network.
Most papers appearing in the surgical literature dealing with wound ballistics concern themselves with wound management in the civilian setting. The pathophysiology of modern war wounds is contrasted with ballistic wounds commonly encountered in peacetime, but it should be noted that even in peacetime the modern terrorist may have access to sophisticated military weaponry, and that patients injured by them may fall within the catchment area of any civilian hospital. Management problems associated with both wound types are highlighted; areas of controversy are discussed. The orthodox military surgical approach to ballistic wounds is expounded and defended. PMID:1996857
It is experimentally demonstrated that a relatively strong ion-rich sheath formed at a fixed negative bias of the grid can be changed to a rather weak ion sheath (sheath potential weakly retards electrons) only by increasing the discharge voltage in the system. At sufficiently high negative grid bias, an increase of discharge voltage enhances the ion collection current at the grid. An explanation is put forward in support of this experimental observation. A slight density enhancement with a fall in plasma electron temperature is also observed with the increasing negative grid bias. (authors)
In an ideal system the surface of the dish is perfectly parabolic (no contour flaws are present), and the sun rays fall on the dish surface parallel to the focal axis (no sun tracking flaws are present). These two conditions are not realizable in practice; in this case, the parabolic dish system is called real system. In this paper a procedure for analysing the flux distribution on the receiver internal surfaces is presented for a cavity receiver with a real parabolic dish collector. First, the theoretical principles are discussed. Then the effect of the inaccuracy in the collector and in the sun tracking on the insolation pattern is described using an example.
This article describes innovations in new-boiler startups, based on experiences at United Development Group`s 50-MW Niagra cogeneration facility, Niagra Falls, NY. The plant comprises: a circulating coal fluidized bed boiler supplying steam to a nearby factory and electricity to the grid. Before operation the system was flushed with demineralized water, and the boiler degreased, the steam blow relied on a new procedure involving a continuous flow of steam. Startup was then initiated, following manufacturers heatup rate and soak times closely. After startup boiler tube sections were checked, and cleaned if necessary. 1 fig.
The foils of various materials were irradiated with "6"0Co with an activity of 11,538 TBq. The minimum radiation dose was 25 kGy. Changes in chemico-physical properties were evaluated by infrared spectroscopy and were not detected after irradiation with 25 kGy. Packing foils were subjected to the following tests: mechanical tests, tests of weld strength, tests of impact resistance, free fall tests, permeability tests for water vapour and microbiological tests. The results of all tests were tabulated. The tests showed that the foils are impermeable for microorganisms and provided the welds are airtight the packed products remain sterile. (J.P.).
A proposal is made to test Newton's inverse-square law using the perihelion shift of test masses (planets) in free fall within a spacecraft located at the Earth-Sun L2 point. Such an Artificial Planetary System In Space (APSIS) will operate in a drag-free environment with controlled experimental conditions and minimal interference from terrestrial sources of contamination. We demonstrate that such a space experiment can probe the presence of a "hidden" fifth dimension on the scale of a micron, if the perihelion shift of a "planet" can be measured to sub-arc-second accuracy. Some suggestions for spacecraft design are made.
The asymptotic functions are a new type of generalized functions. But they are not functionals on some space of test-functions as the distributions of Schwartz. They are mappings of the set denoted by A into A, where A is the set of the asymptotic numbers introduced by Christov. On its part A is a totally-ordered set of generalized numbers including the system of real numbers R as well as infinitesimals and infinitely large numbers. Every two asymptotic functions can be multiplied. On the other hand, the distributions have realizations as asymptotic functions in a certain sense. (author).
New surface photometry of all known elliptical galaxies in the Virgo cluster is combined with published data to derive composite profiles of brightness, ellipticity, position angle, isophote shape, and color over large radius ranges. These provide enough leverage to show that Sersic log I #propor to# r "1"/"n functions fit the brightness profiles I(r) of nearly all ellipticals remarkably well over large dynamic ranges. Therefore, we can confidently identify departures from these profiles that are diagnostic of galaxy formation. Two kinds of departures are seen at small radii. All 10 of our ellipticals with total absolute magnitudes M_V_T #<=# -21.66 have cuspy cores-"missing light"-at small radii. Cores are well known and naturally scoured by binary black holes (BHs) formed in dissipationless ("dry") mergers. All 17 ellipticals with -21.54 #<=# M_V_T #<=# -15.53 do not have cores. We find a new distinct component in these galaxies: all coreless ellipticals in our sample have ...
The thermochemical calculations performed with a large number of elements to describe the chemical system in a Phebus FP test allow the following conclusions: The metallic absorber materials play a significant role in fission product speciation. At around 1000 C and above, silver iodide is the dominant iodine carrier in a full steam atmosphere in both FPT0 and FPT1. At lower temperatures, cadmium iodide takes over. In a reduced environment, indium iodide becomes important. Caesium iodide does certainly appear; at certain test conditions it becomes the major iodine transporting vehicle. But its role is not greater than that of the other iodides. It has more chances in FPT1 than in FPT0. Chlorine, which was present in FPT0 as a contaminant in relatively large amounts, does not prevent the iodine from forming Csl. Both share the caesium like partners. The evolution of caesium chloride and iodide proceeds in parallel. When CsCl is abundant, Csl is strong, too. Should ...
The aim of the current investigation was to study the effects of sevelamer hydrochloride (RenaGel) on serum phosphate, intact parathyroid hormone levels (iPTH), and lipid profiles in stable hemodialysis patients. Hemodialysis patients maintained on calcium containing phosphate binders were enrolled in this study. Following two weeks of washout of the phosphate binders, serum phosphate rose from 6.4 +/- 0.6 to 10.5 +/- 0.7 mg/dl (p <0.001). After 8 weeks of titration with sevelamer hydrochloride, serum phosphate fell by 4.5 +/- 0.3 to 6.3 +/- 0.7 mg/dl (p <0.0001). Serum calcium levels fell during washout (9.8 +/- 0.4 to 8.9 +/- 0.3 mg/dl, p <0.004) and were unaffected by sevelamer hydrochloride. Sevelamer hydrochloride administration was associated with a 23.0 +/- 3.1% fall in total cholesterol, a 35.9 +/- 3.0% fall in LDL cholesterol, and a 35.2 +/- 5.3% fall in the LDL:HDL cholesterol ratio (p <0.001). There ...
...of stations and a number of components, and meta information on air quality monitoring networks and stations. Access the database Producer Europe Environment Agency Content ...of stations and a number of components, and meta information on air quality monitoring networks and stations. Coverage National (Europe) Number of records...
Copy number variants (CNVs) are an important component of genomic variation in humans and other mammals. Similar de novo deletions and duplications, or copy number changes (CNCs), are now known to be...Full Text Available
Changes in the number of chromosomes, but also variations in the copy number of chromosomal regions have been described in various pathological conditions, such as cancer and aneuploidy, but also in...Full Text Available
The transport and partitioning of {sup 129}I has been examined for a shallow groundwater flow system at Sturgeon Falls in northeastern Ontario. Recharge into a sandy surficial postglacial deltaic aquifer occurs in the vicinity of a seasonally-wet boreal forest. Concentrations of stable iodine, {sup 129}I, tritium, radiocarbon, stable isotopes and major ions were measured on samples of groundwater and precipitation. The present-day tritium profile delineates the position of the early 1960's above-ground nuclear weapons pulse at a depth of approximately 12 m. The concentrations of stable iodine for groundwaters above, near and below the above-ground nuclear weapons pulse range from 0.07 to 1.7 ppb. Over that same interval {sup 129}I concentrations decreased from 1.9 x 10{sup 6} atoms/L at 9 m, to approximately 1.9 x 10{sup 5} atoms/L in tritium-depleted waters at 35 m, below the present-day depth of the recharging above-ground nuclear weapons peak at ...
A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding atypical math development. Adults with a diagnosis of dyscalculia (DYS) during childhood were compared to adults with average or high abilities in mathematics across two bisection tasks. Participants were presented with Arabic number triplets and had to judge either the number magnitude or the spatial location of the middle number relative to the two outer numbers. For the numerical judgment, adults with DYS were slower than both groups of control peers. They were also more strongly affected by the factors related to number magnitude such as the range of the triplets or the distance between t...
Numerical solutions given by a vorticity-velocity method are presented for combined free and forced laminar convection in the thermal entrance region of a horizontal rectangular channel without the assumptions of large Prandtl number and small Grashof number. The channel wall is heated with a uniform wall heat flux. Typical developments of temperature profile, secondary flow, and axial velocity at various axial positions in the entrance region are presented. Local friction factor and Nusselt number variations are shown for Rayleigh numbers Ra = 10{sup 4}, 3 {times} 10{sup 4}, 6 {times} 10{sup 4}, and 10{sup 5} with the Prandtl number as a parameter. The solution for the limiting case of large Prandtl number and small Grashof number obtained from the present study confirms the data of existing literature. It is observed that the large Prandtl ...
We present a Poincare covariant Faddeev equation, which enables the simultaneous prediction of meson and baryon observables using the leading order in a truncation of the Dyson-Schwinger equations that can systematically be improved. The solution describes a nucleon's dressed-quark core. The evolution of the nucleon mass with current-quark mass is discussed. A nucleon-photon current, which can produce nucleon form factors with realistic Q{sup 2} evolution, is described. Axial-vector diquark correlations lead to a neutron Dirac form factor that is negative, with r{sub 1}{sup nu}>r{sub 1}{sup nd}. The proton electric-magnetic form factor ratio falls with increasing Q{sup 2}.
High levels of unemployment are a permanent feature in the urban areas of many developing countries. South Africa is no exception in this regard. Poverty and hardship caused by unemployment force many participants in the labour market to venture into the urban informal economy in order to survive. The activities of the waste pickers fall within the urban informal economy. In spite of the fact that waste pickers are a common sight in the urban areas of Pretoria and other South African cities, remarkably little is known about them and scant attention is paid to them. The aim of the study was to establish a socio-economic profile of the street waste pickers in Pretoria and to describe the social interaction and relationship dynamics between the waste pickers and their families, each other, th...
The following thermal-neutron fission cross sections have been measured in the thermal column of the Materials "Testing Reactor at Idaho Falls, Idaho: Pu/ sup 238/, 18.4 plus or minus 0.9 b; Am/sup 241/, 3.13 plus or minus 0.15 b; Am/sup 245/, 6390 plus or minus 500 b; Am/sup 243/, <0.072 b Cm/sup 243/, 690 plus or minus 50 b; Cm/sup 245/, 1880 plus or minus 150 b. In addition, a pile neutron capture cross section of 520 plus or minus 40 b has been measured for Pu/sup 238/. (auth)
A stratigraphic and geochemical study of alpine soils, which formed in later Pleistocene (late glacial) and Neoglacial deposits in the Wind River Mountains of western Wyoming, indicates that these soils are affected by air-fall in flux of inorganic pollutants. Arsenic, bromine and antimony appear to have been deposited in surface soils by incorporation of aeolian materials which were presumably transported by winds from industrial sources, including coal-burning operations. As vanadium was not found in surface soils at concentrations above site-specific background levels, oil-fired energy generating stations were not found to be significant sources of surface soil pollution in the region. Acid-rain effects were not observed in the soils. (author) 32 refs.; 2 figs.; 3 tabs.
One of the most remarkable features of string theories is that they seem to provide a framework for a consistent theory of quantum gravity which is unified with all other forces. String theories fall into the two basic, a priori equally interesting, categories of open and closed string theories. For the past five years virtually all attention has been focused on purely closed string theories even though the reincarnation of string theory began with the discovery of anomaly cancellation and finiteness in the Green-Schwarz open superstring. It is the authors' purpose in this essay to rekindle interest in open string theories as potential theories of nature, including gravity. All string theories naively contain a massless dilaton which couples with the strength of gravity in direct violation of experiment. They present a simple mechanism for giving the dilaton a mass in unoriented open bosonic string theories.
One hypothesis for the decline of the North American greater (Aythya marila) and lesser (A. affinis) scaup population is that contaminant burdens acquired on wintering or staging areas impair reproduction or cause lethal or sublethal health effects. Recent studies have found increased selenium (Se) concentrations in scaup but have focused on the fall and spring staging periods. From January to March 2006 and December to March 2006 and 2007, we analyzed liver tissues collected from greater scaup wintering in western Lake Ontario for 16 trace elements. We also measured Se concentrations in greater scaup blood and Dreissenid mussel tissue. Se was the only trace element that occurred at increased concentrations (>10??g/g liver dry weight) in a substantial proportion (99%) of greater scaup live...
Throughout much of the 1980s, deforestation in Brazil eliminated more than 15,000 square kilometers (9000 square miles) of forest per year. Data gathered by several satellites in the Landsat series of spacecraft shows enormous tracts of forest disappearing in Rondonia, Brazil from 1975 through 2001. The human phenomenon of deforestation starts, especially in the dense tropical forests of Brazil, when systematic cutting of a road opens new territory to potential deforestation by penetrating into new areas. Clearing of vegetation along the sides of those roads then tends to fan out to create a pattern akin to a fish skeleton. As new paths appear in the woods, more areas become vulnerable. Finally, the spaces between the skeletal bones fall to defoliation.
Recent research findings of epidemiologist Alice Stewart suggest that nuclear workers may be at risk of contracting cancer even though their measured occupational doses fall within current safety standards. It is argued that these standards are inappropriate as they are based on extrapolations of studies on survivors of the Hiroshima and Nagasaki explosions. These individuals received single doses of radiation, whereas today's nuclear industry personnel are exposed to low-level ionizing radiation over the length of their working lives. Stewart's team linked low dose occupational exposure to ionizing radiation with an increased risk of cancer in respiratory, digestive and blood-forming tissues. The nuclear industry and United States government agencies hotly contest these assertion with their potentially damaging political and economic consequences. (UK).
Recent research findings of epidemiologist Alice Stewart suggest that nuclear workers may be at risk of contracting cancer even though their measured occupational doses fall within current safety standards. It is argued that these standards are inappropriate as they are based on extrapolations of studies on survivors of the Hiroshima and Nagasaki explosions. These individuals received single doses of radiation, whereas today's nuclear industry personnel are exposed to low-level ionizing radiation over the length of their working lives. Stewart's team linked low dose occupational exposure to ionizing radiation with an increased risk of cancer in respiratory, digestive and blood-forming tissues. The nuclear industry and United States government agencies hotly contest these assertion with their potentially damaging political and economic consequences. (UK).
Since 1970, officers on the Seattle campus have regularly patrolled the hallways of dormitories of the University of Washington. It is a community-policing strategy, a low-key way to engage students. However, the practice might cease this fall. In June, the state's Court of Appeals ruled that students have the same right to privacy in dormitory hallways as they do in their rooms. Therefore, the court concluded, campus police officers lack the legal authority to randomly patrol residence halls. Although the closely watched ruling bears on only one state, it reveals the tension between privacy and security in dormitories everywhere. Residence halls are legally complex spaces, where crime often creeps in and where residents, perhaps more than ever, expect administrators and police officers to ensure their safety.
Capital investment in extra heavy crude production is expected to increase from $6 billion to $25 billion by 2005. In response to this forecast, producers are focusing their efforts on improving the quality of extra heavy crude right at the production sites to reduce their dependence on diluent, reduce pipelining costs, and to receive a higher return for their investment. Their efforts would also minimize environmental impacts at production sites. This slide presentation also proposed a solution to the problem associated with stability and incompatibility of thermal upgrading by taking advantage of the inherent incompatibility of extra heavy crudes and paraffinic diluents and using diluents to perform selective decarbonization (or the partial removal of asphaltene) to reduce heavy crude viscosity and density. A pilot-scale test has been conducted and a bench-scale unit will be carried out in Fall 2000.
A 100-bit slitlike aperture array spatial light modulator has been developed using 8.8/65/35 PLZT for a high-bit-density 1-D hologram memory. The most desirable characteristics, such as distortion-free diffraction-limited Fourier transform patterns and good uniformity of displayed bit patterns over 100 bits, have been realized. The lowest SNR was 86, and rise time and fall time have been 30 microsec and 8 microsec, respectively, at 190-V halfwave voltage. One-dimensional holographic storage experiments have been successfully performed using this PLZT spatial light modulator. PMID:20216813
MINER?A is a high resolution, fully active detector designed to study neutrino interactions on nuclei in the NuMI beam at Fermi National Accelerator Laboratory. The active volume of the detector consists of 3 tons of plastic scintillator and includes embedded targets of 4He, C, H2O, Fe and Pb. The MINER?A collaboration expects to perform precision, A-dependent neutrino cross section measurements in the 1?10 GeV region, measure the axial form factor, and study nuclear shadowing of F2, quark-hadron duality and coherent pion production, among other topics. MINER?A began data taking in the fall of 2009. This paper describes the MINER?A experiment and provides an overview of the physics objectives along with estimated uncertainties of the measurements and the tentative projected schedule of dat...
In contrast to language, where pitch patterns consist of continuous and curvilinear contours, musical pitch consists of relatively discrete, stair-stepped sequences of notes. Behavioral and neurophysiological studies suggest that both tone-language and music experience enhance the representation of pitch cues associated with a listener's domain of expertise, e.g., curvilinear pitch in language, discrete scale steps in music. We compared brainstem frequency-following responses (FFRs) of English-speaking musicians (musical pitch experience) and native speakers of Mandarin Chinese (linguistic pitch experience) elicited by rising and falling tonal sweeps that are exemplary of Mandarin tonal contours but uncharacteristic of the pitch patterns typically found in music. In spite of musicians' unf...
SUMMARY Spontaneous potentials associated with volcanic activity are often interpreted by means of the electrokinetic potential, which is usually positive in the flow direction (i.e. Zeta potential of the rock is negative). The water-rock interactions in hydrothermal zones alter the primary minerals leading to the formation of secondary minerals. This work addresses the study of calcite precipitation in a sand composed of 98 per cent quartz and 2 per cent calcite using streaming potential measurements. The precipitation of calcite as a secondary mineral phase, inferred by high calcite saturation indices and by a fall in permeability, has a significant effect on the electrokinetic behaviour, leading to a significant reduction in the Zeta potential (in absolute value) and even a change in si...
This poster presentation details the procedure that was followed for the development of the Mine Environment Neutral Drainage (MEND) manual. This manual was developed to provide a detailed summary of the important results obtained through studies sponsored by the MEND program and other studies conducted on topics related to acid mine drainage. The manual was divided into volumes dealing with topics such as summary, sampling and analysis, predictions, prevention and control, treatment, and monitoring. Details concerning the format, research conducted under the auspices of MEND, utilization and limitations, methodology, variations, costs, and references were also discussed. The author stated that the manual is to be used as a guide. The proposed English publication dates for the volumes were indicated, and they ranged from the fall of 2000 for volumes 3, 5, and 6, to the CD-ROM publication in March 2001. The French publication is expected to be in print by mid 2001. ...
The energy cost of compressors accounts for up to 90% of the total cost. Oil-free compressors could reduce the cost almost by half, i.e. annual savings of 112,500 DM would be achievable. [German] Ueber die Gesamtlaufzeit betrachtet, machen die Energiekosten bei Verdichtern bis zu 90% der Gesamtkosten aus. Deshalb muss bei der Auswahl von Kompressoren dem Energieverbrauch besondere Aufmerksamkeit geschenkt werden. Mit oelfreien Kolbenkompressoren liessen sich in einem speziellen Fall die Kosten fast halbieren, was jaehrlichen Einsparungen von 112 500 DM entspricht. (orig.)
Two sodium cooled reactors are currently being operated in the United States of America for the US Department of Energy. These are Experimental Breeder Reactor 11, EBR-11, and the Fast Flux Test Facility, FFTF. EBR-11 is located near Idaho Falls, Idaho, and the FFTF is near Richland, Washington. These reactors are currently engaged in a wide range of testing including fuels and materials tests, and plant system performance and safety development. The US DOE program also includes designs of a next generation sodium cooled power reactor. The FFTF and EBR-11 communities are providing input to these designs. This paper discusses the efforts to develop and operate cover gas systems for the sodium cooled nuclear reactor program in the USA.
The Linac Coherent Light Source [1] (LCLS) at SLAC National Accelerator Laboratory is preparing for the arrival of its first scientific users in the fall of 2009. LCLS is the world's first free-electron in the spectral range 800-8,000 eV, producing intense, sub-picosecond pulses of Xrays with very high spatial coherence. The accelerator facility has been commissioned in stages, beginning in April 2007 [2] with the injector linac and culminating in December 2008 [3] with the first transport of electrons through the complete beam path. On April 10, 2009, the LCLS Project team was rewarded for years of planning, design, construction, and checkout with a dream-come-true: as undulators were placed on the beam path one-by-one, the laser simply turned on without drama in the course of one hour [4...
The authors determined migration timing and abundance of juvenile spring chinook salmon Oncorhynchus tshawytscha and juvenile steelhead/rainbow trout O. mykiss from three populations in the Grande Ronde River basin. Based on migration timing and abundance, two distinct life-history strategies of juvenile spring chinook and O.mykiss could be distinguished. An early migrant group left upper rearing areas from July through January with a peak in the fall. A late migrant group descended from upper rearing areas from February through June with a peak in the spring.
This paper studies the electrical characteristics of hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs) under flat and bending situations after AC/DC stress at different temperatures. Stress temperature was varied from 77K to 400K, and threshold voltage shifts were extracted to analyze degradation mechanisms. It was found that high temperature and mechanical bending played important roles under AC stress, with an enhanced stress effect resulting in a more serious degradation. This study also discusses the dependence between the accumulated sum of bias rising and falling time and the threshold voltage shifts under AC stress.
Outcome from trauma, surgery, and a variety of other medical conditions has been shown to be positively affected by providing treatment at facilities experiencing a high volume of patients with those conditions. An electronic literature search was made to identify English-language articles available through March 2011, addressing the effect of patient treatment volume on outcome for patients with subarachnoid hemorrhage. Limited data were identified, with 16 citations included in the current review. Over 60% of hospitals fall into the lowest case-volume quartile. Outcome is influenced by patient volume, with better outcome occurring in high-volume centers treating >60 cases per year. Patients treated at low-volume hospitals are less likely to experience definitive treatment. Furthermore, t...
Graphical Abstract A Southward view of the Dead Sea western coast. The steep western escarpment of the Dead Sea basin, composed mainly of Upper Cretaceous limestone and dolomite, can be seen on the right. Beach terraces left by the shrinking lake run parallel to the shore. The larger part of the area between the present water line and the mountains was still under Dead Sea water just 50?60?years ago. The current fall of the lake?s stand is around 1?m?year?1. Three on-shore sinkholes can be seen in the front of the photo, as well as two submerged ones near its lower left corner. These were caused by dissolution of a Holocene salt layer located tens of meters below the surface, resulting in the collapse of the overlying sediments. The retreat of the Dead Sea in recent years was followed by e...
Stellar rotation velocities and velocity dispersions have been measured along the major and minor axes of NGC 4594 with the Canada-France-Hawaii Telescope. The observations show the kinematic signature of a nuclear disk of stars superposed on the bulge (Fig. 1). Apart from its larger size, this is similar to the nucleus of M31. It rotates rapidly: the apparent rotation curve reaches an inner maximum of V 231 #+-# 7 km s"-"1 at r = 5.''0. The apparent velocity dispersion falls from #sigma# = 250 #+-# 7 km s"-"1 at the center to 181 #+-# 6 km s"-"1 at r = 3.''7. (author).
Geometrical shapes and diameter of nuclear tracks changes continuously during the process of etching for various incident angles. Besides, there is also a marked difference amongst their profiles, as evidenced by the SEM analysis, when the incoming particles fall on the detector at different angles of incidence. This work outlines this aspect of fission fragment tracks in a glass detector and has set out a few empirical relationships between the mean track diameter, d-bar and the etching time, t, within experimental limits. This study, therefore, sheds some light in the follow up the origins and characteristics of heavy ions in some terrestrial and extra-terrestrial materials and also in studying the collimation accuracy of heavy ion bombardments. The implications of the results in discerning the measurements of incident angles of various types of ions are described in detail in the paper.
Modern day accelerator development encompasses a myriad technologies required for their diverse needs. Whereas RF, high voltage, vacuum, cryogenics etc., technologies meet their functional requirements, high finish lapping processes, ceramic-metal joining, oven brazing, spark erosion or wire cutting etc., are a must to meet their fabrication requirements. Electromagnetic (EM) forming technique falls in the latter category and is developed as a special technology. It is currently catering to the development as a nuclear reactor technology, but has the potential to meet accelerator requirements too. This paper highlights the general principle of its working, simple design guidelines, advantages, and suggests some specific areas where this could benefit accelerator technologies
Increasing the end coking temperature to 850 C has a marked effect on both the physico-mechanical and physico-chemical properties of formed coke, and although subsequent rise in temperature leaves the mechanical strength largely unaltered, it appears to increase hardness, real density and conductivity at the expense of diminished reactivity. Formed coke strength can be slightly improved by extending the coking time by an isothermal residence period at end temperatures of 650 and 750 C. Structural change in the formed coke tends to concentrate in the 450 to 650 C range where carbon increases by 6.98-8.27% as compared with hydrogen and oxygen which fall 2.40-3.53 and 3.50-4.62% respectively.
Applied science may once again play a decisive role in changing the face of armed conflict, and the rest of human affairs, by shifting the battlefield to our very brains. The national-security establishment--and particularly the Pentagon's Defense Advanced Research Projects Agency (DARPA)--supports research at the intersection of neuroscience and national security that could ultimately enable authorities to do things like enhance (or muddle, or erase) memory, monitor crowds for individuals whose brain patterns correlate with aggressive behaviors, or control weapons from afar merely with thoughts. What are the dangers of such information falling into "the wrong hands," and are there any "right hands" for this kind of knowledge? Is any extension of human abilities justified by the need for government to protect its society? PMID:15986543
A reference design was used in preparing a mathematical model of a fusion power plant with a tokamak reactor to investigate the extent to which the uncertainty still inherent in the physical reactor parameters affects the power costs. While only limited reductions of the power costs are achieved by improvements of the reference values for the reactor burn time, power density in the torus and load on the first wall, the power costs rise in keeping with the extent to which these parameters fall short of the reference values. As the results obtained in present-day experiments are still well below the reference values, a great deal of effort is still required in the fields of plasma physics and materials research to achieve an economically operating fusion power plant. (orig.).
Cathode materials for rechargeable rocking chair or lithium-ion batteries, are reviewed. The emphasis is placed on the comparison between specific capacities and rechargeability of lithium-containing high voltage cathode materials such as manganese oxides and LiMO{sub 2} compounds, where M is Co or Ni. It is generally found that the maximum reversible capacities for the most promising materials fall in the range 100-120 mAh/g, and decaying to around 75 mAh/g after several hundred cycles. The rechargeability is similar for the most commonly considered materials: LiMn{sub 2}O{sub 4}, LiCoO{sub 2} and LiNiO{sub 2}. No improvements in capacity or rechargeability, beyond what have been found for these materials, is observed by substitution of other elements into these compounds
The pair $(G_H,\\cdot)$ is called a special loop if $(G,\\cdot)$ is a loop with an arbitrary subloop $(H,\\cdot)$. A special loop $(G_H,\\cdot)$ is called a second Smarandache Bol loop(S$_{2^{{\\tiny\\textrm{nd}}}}$BL) if and only if it obeys the second Smarandache Bol identity $(xs\\cdot z)s=x(sz\\cdot s)$ for all $x,z$ in $G$ and $s$ in $H$. The popularly known and well studied class of loops called Bol loops fall into this class and so S$_{2^{{\\tiny\\textrm{nd}}}}$BLs generalize Bol loops. The basic properties of S$_{2^{{\\tiny\\textrm{nd}}}}$BLs are studied. These properties are all Smarandache in nature. The results in this work generalize the basic properties of Bol loops, found in the Ph.D. thesis of D. A. Robinson. Some questions for further studies are raised.
The Monte-Carlo method and experimental methods were used to determine the neutron fluxes in the irradiation channels of the Ghana Research Reactor -1. The MCNP5 code was used for this purpose to simulate the radial and axial distribution of the neutron fluxes within all the ten irradiation channels. The results obtained were compared with the experimental results. After the MCNP simulation and experimental procedure, it was observed that axially, the fluxes rise to a peak before falling and then finally leveling out. Axially and radially, it was also observed that the fluxes in the centre of the channels were lower than on the sides. Radially, the fluxes dip in the centre while it increases steadily towards the sides of the channels. The results have shown that there are flux variations within the irradiation channels both axially and radially. (au)
Calcaneus quantitative ultrasound (QUS) assessment is a safe and reliable method for evaluating skeletal status. Until now, considerable data have been accumulated on the distribution of QUS in Caucasian populations, whereas such data are still insufficient in Asian populations, especially in Chinese mainland. The present study aimed to obtain the distribution characteristic of calcaneus QUS in healthy Chinese women, and to further investigate the distribution of low bone mass by QUS stiffness index (SI). This study included 2,498 healthy Chinese females aged 10-87 yr. The QUS exhibited a characteristic mild rise and then fall pattern with increasing age. Age, body height, and weight were significant influencing factors on SI, especially age and weight. The prevalence of osteoporosis detec...
Last year, 1991, was a difficult one for Finland's oil and chemicals company, Neste Corporation. The sharp fall in the international price of chemicals products had a significant impact on the corporation's overall result. Neste was, however, able to improve its competitive position, move ahead with numerous investments, and develop new businesses. This was particularly evident in two areas that have received significant emphasis within Neste in recent years: oil exploration and the Baltic region where a network of modern service stations in Neste livery and stretching from Vyborg on the Finnish-Russian border, through St. Petersburg, Tallinn, and the Baltic countries to Warsaw, is currently taking shape. The majority of the western-style stations in this network will be located along the route of the M12 highway, which has been dubbed the Via Baltica.
Villarrica (Chile) is one of the most active volcanoes in South America having erupted about 60 times in the last 460years. Although its historical eruptive activity has been mainly effusive and weakly explosive, it had strong explosive behaviour in postglacial times. Chaimilla (<3.1ka) is one of the best exposed and widely dispersed pyroclastic deposits, related to both fall and flow activity. The deposit is dispersed over an area of 250km^2 and consists of 8 units (A-H) which were grouped into four sequences. Stratigraphic data suggest that the eruption had a relatively short duration and evolved from i) an Opening phase, dispersing ash, lapilli clasts, accretionary lapilli, blocks and bombs, to ii) a Pulsatory phase, originating a series of magmatic explosions, to iii) a Collapsing phas...
The lower continental slope of the northwestern Gulf of Mexico is characterized by a hummocky topography with shallow salt masses interspersed by numerous salt-withdrawal basins containing thick Plio-Pleistocene and older sediments. Analysis of over 7500 km of multichannel seismic reflection data from the Keathley Canyon Area and vicinity defined the Wisconsinan-Holocene sequence and its seismic facies. In interbasinal areas and in the southern part of the study area where salt is shallow, the Wisconsinan-Holocene sequence consists mainly of low-amplitude (LA) facies underlain by strong basal-reflection (SBR) facies. The LA facies occasionally show subtle onlaps against SBR facies and grade upward into a draping pattern. Onlapping LA facies are interpreted to be a lowstand systems tract deposited by widespread low-energy turbidity currents. Draping LA facies at the top may consist of hemipelagic or pelagic sediments. The SBR facies are interpreted to consist of condensed sections ...
A series of upper tropospheric radon concentration measurements made over the eastern Pacific and west coast of the United States during the summers of 1983 and 1984 has revealed the occurrence of unexpectedly high (>16 pCi/SCM) radon concentrations for 9 of the 61 measurements (and 6 of the 13 flights). A frequency distribution plot of the set of 61 observations shows a distinct bimodal distribution, with approximately 2/5 of the observations falling close to 1 pCi/SCM, and 3/5 falling in a high concentration mode centered at about 11 pCi/SCM. Trajectory and synoptic analyses for two of the flights on which such high radon concentrations were observed indicate that this radon-rich air originated in the Asian boundary layer, ascended in cumulus updrafts, and was carried eastward in the fast moving air on the anti-cyclonic side of the upper tropospheric jet. Transit times were of the order of 3 days; however, in one instance, transport from ...
The regenerator of Stirling cycle machines has an relatively unknown potential for thermal shorting, because the thermal flow path within the solid of a randomly stacked wire mesh, which is defined by its 'connectivity', is unknown. Earlier publications have shown two principles of experimental techniques to quantify connectivity. One quantifies connectivity as a function of axial pressure using the electric current analogy, the other measures connectivity via the temperature gradients along a regenerator and a series-connected reference body of known conductivity. Both papers offer preliminary results of reduced usefulness related to the testing method or setup. This contribution describes a new setup and its technique, which results from the practical knowledge and experience of the first two attempts, and aims for an improved determination of connectivity of the original representative Stirling regenerators with and without housing. Please contact the author for ...
The Buntsandstein facies outcrops along a 12 km long, 150 m thick cuesta near Ayllon (Central Spain). The outcrop study is based on vertical sedimentological sections and continuous photo paneling, and demonstrates the presence of two depositional systems: an alluvial fan system in the lower half of the outcrop, and a straight and braided river system in the upper part of the outcrop. This overall evolution is probably related to base-level fall to base-level rise cycle, in which the reservoir architecture is linked to genetic units stacking pattern: during the base-level fall, the alluvial fan is prograding over sand flat and sandy alluvial plain deposits. Coarse and pebbly proximal sandsheets are interbedded with finer reddish distal deposits. Reservoirs units are laterally continuous, but silty alluvial plain deposits constitute vertical permeability barriers, during base-level stillstand, erosive channels and sandsheets are vertically ...
The Bonneville Power Administration (BPA) initiated the Augmented Fish Health Monitoring project in 1986. This project was a five year interagency project involving fish rearing agencies in the Columbia Basin. Participating agencies included: Washington Department of Fisheries (WDF), Oregon Department of Fish and Wildlife, Idaho Department of Fish and Game, and the US Fish and Wildlife Service (USFWS). This is the final data report for the Augmented Fish Health Monitoring project. Data collected and sampling results for 1990 and 1991 are presented within this report. An evaluation of this project can be found in Augmented Fish Health Monitoring, Volume 1, Completion Report.'' May, 1991. Pathogen detection methods remained the same from methods described in Augmented Fish Health Monitoring, Annual Report 1989,'' May, 1990. From January 1, 1990 to June 30, 1991 fish health monitoring sampling was conducted. In 1990 21 returning adult stocks were ...
are you exchanging data or metadata through specific agreements with a defined number of partners? or are you intending to make data or metadata available in a more "open" environment, with the expectation that it may be used by a potentially unlimited number of services? ...
Background and AimsTrade-offs are fundamental to life-history theory, and the leaf size vs. number trade-off has recently been suggested to be of importance to our understanding...Full Text Available
BackgroundDue to the increased accuracy of Copy Number Variable region (CNV) break point mapping, it is now possible to say with a reasonable degree of confidence whether a gene...Full Text Available
The scaling of reproductive parameters to body size is important for understanding ecological and evolutionary patterns. Here, we derived allometric relationships for the number and mass of seeds, eggs...Full Text Available
Various energy sources and motors of divers types can be used in electric cars with operating modes subjected to a number of particular constraints. As a result, the possible structures of the converters, that are analysed in detail, are about a dozen in number. Also considered is the use of solid-state components - thyristors, power transistors and new components.
Objectives:Copy number variants (CNVs) have been recognized as a source of genetic variation that contributes to disease phenotypes. Alzheimer disease (AD) has high heritability...Full Text Available
The number of nuclear pore complexes (NPCs) in individual nuclei of the yeast Saccharomyces cerevisiae was determined by computer-aided reconstruction of entire nuclei from electron...Full Text Available
This report describes how Nigeria, a country that at one time had the highest number of cases of dracunculiasis (Guinea worm disease) in the world, reduced the number of cases from more than 653,000...Full Text Available
BackgroundRecently, the discovery of copy number variation (CNV) led researchers to think that there are more variations of genomic DNA than initially believed. Moreover, a certain...Full Text Available
The effect of transverse magnetic field parameter (Hartmann number, Ha) Reynolds number (Re) and Prandtl number (Pr) on the mixed convection flow past a semi-infinite vertical porous plate in a non-Darcian porous medium with variable viscosity and porosity, viscous dissipation and fluid-solid thermal conductivity ratio in the presence of plate transpiration (lateral mass flux) is investigated theoretically and numerically using Keller`s implicit finite difference scheme. It is shown that the Harmann number acts as a retarding force and increases the momentum boundary layer thickness, analogous to the flow against a positive pressure gradient, simultaneously decreasing local skin friction (shear stress). The heat transfer rate is however enhanced by the magnetic field (for positive values of the Eckert number) since the fluid is heated and temperature gradients become reduced between ...
The improvement of startability achieved by chemical ignition promotion at low temperature was studied theoretically and experimentally in terms of compression ratio and cetane number using a small direct injection diesel engine. The findings are as follows: The compression ratio and cetane number vary almost linearly. When the compression ratio increases by 1, the cetane number decreases by about 9. Since almost the same ignition condition at starting can be achieved by adjusting the number of cranking cycles, there is almost no influence of compression ratio and cetane number on ignition delay. When the soak temperature is -10{sup 0}C and the compression ratio is 18, the influence of the cetane number is almost negligible. Given the same starting time, the influence produced by an increase in compression ratio by 1 is equivalent to the influence produced by a ...
Structural variants which cause changes in copy numbers constitute an important component of genomic variability. They account for 0.7% of genomic differences in two individual genomes, of which...Full Text Available
of increasing numbers of vortices as a function of the thickness. Vortices are these whirlpool shaped structures. They are interesting because they come paired with...
The laminar incompressible hydrodynamically fully developed and thermally developing flow is studied in a curved square duct with four longitudinal fins. The duct is successively subjected to constant wall temperature, to circumferentially uniform temperature and axially linearly or exponentially varying temperature. The local and fully developed Nusselt numbers are examined for various values of the Dean number and it is found that the heat transfer rate increases for high fins. The parameters that affect the entry length are studied and the fluctuations of the local Nu that appear in the entrance region are investigated. Temperature contour plots are presented for the visualization of the temperature field and functional relations for the Nusselt number are proposed in terms of the Dean and Prandtl numbers. (orig.)
We apply the generalised concept of witness operators to arbitrary convex sets, and review the criteria for the optimisation of these general witnesses. We then define an embedding of state vectors and operators into a higher-dimensional Hilbert space. This embedding leads to a connection between any Schmidt number witness in the original Hilbert space and a witness for Schmidt number two (i.e. the most general entanglement witness) in the appropriate enlarged Hilbert space. Using this relation we arrive at a conceptually simple method for the construction of Schmidt number witnesses in bipartite systems.
In connection with some applications of asymptotic numbers and asymptotic functions, proposed by Khr.Khristov, the problem of describing subsets of asymptotic numbers closed with respect to algebraic operations arises. The algebraic operations with asymptotic numbers are defined by classes of their representatives. All trivial or noncharacteristic solutions are avoided. A procedure for constructing sets of elements closed under action of an algebraic operation or a combination of two or more of them is given. It turns out that the closed sets are given by their kernels, the last being the minimal subsets which generate the whole set by the introduced algebraic operations. It is proved that such kernels exist always. . The closed sets are described by their correspondence with the kernels. (S.P.).
... of drag measurements with the AGARD Nozzle Afterbody ... are discussed separately from flows with a ... bubbles introduce typical flow phenomena that ...
hicle [UUV (essentially, a small ex- ploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warm- ...
We give a general local central limit theorem for the sum of two independent random variables, one of which satisfies a central limit theorem while the other satisfies a local central limit theorem with the same order variance. We apply this result to various quantities arising in stochastic geometry, including: size of the largest component for percolation on a box; number of components, number of edges, or number of isolated points, for random geometric graphs; covered volume for germ-grain coverage models; number of accepted points for finite-input random sequential adsorption; sum of nearest-neighbour distances for a random sample from a continuous multidimensional distribution.
... Soviet standard or specification number for each reinforced plastic is included ... The tabular data contains general applications of reinforced plastics. ...
In this paper we establish a fundamental structural result for formal series encoding the total non-archimedean masses of quadratic lattices of varying determinant squareclasses, but with fixed rank $n$ and signature over any fixed number field. We conclude with some local computations for $n=2$, and use these to derive an analytic class number formula for CM extensions.
Experimental and analytical studies in convection cooling and boiling cooling conditions have been performed on natural convection heat transfer with solidified crust formation in the molten metal pool. The present experimental results on the relationship between the Nusselt number and Rayleigh number in the molten metal pool were compared with existing correlations on Rayleigh-Bebard natural convection in an enclosure. A new correlation on the relationship between the Nusselt number and Rayleigh number in the molten metal pool with crust formation has been developed using the experimental data. The experimental results were verified by the analytical study. The experimental study has shown that the bottom surface temperature of the molten metal layer, in all experiments, is the major influential parameter in the crust formation, due to the natural convection flow. The Nusselt ...
In this paper the thermal equilibrium number of solitons in DNA as a function of absolute temperature and the number of base pairs is calculated. These calculations are effected by modeling DNA as a Toda lattice with parameters chosen to match experimentally measured properties of DNA. It is found that a significant number of solitons is generated at physiological temperature. 23 refs., 2 figs.
The double diffusive convection in a horizontal couple stress fluid saturated anisotropic porous layer, which is heated and salted from below, is studied analytically. The modified Darcy equation that includes the time derivative term is used to model the momentum equation. The critical Rayleigh number, wavenumber for stationary and oscillatory modes, and frequency of oscillations are obtained analytically using linear theory. The effect of anisotropy parameter, solute Rayleigh number, Lewis number, couple stress parameter, and Vadasz number on the stationary, oscillatory, and finite amplitude convection is shown graphically. It is found that the thermal anisotropy parameter, couple stress parameter, and solute Rayleigh number have stabilizing effect on the stationary, oscillatory, and fin...
Complex numbers are an intrinsic part of the mathematical formalism of quantum theory and are perhaps its most characteristic feature. In this article, we show that the complex nature of the quantum formalism can be derived directly from the assumption that a pair of real numbers is associated with each sequence of measurement outcomes, with the probability of this sequence being a real-valued function of this number pair. By making use of elementary symmetry conditions, and without assuming that these real number pairs have any other algebraic structure, we show that these pairs must be manipulated according to the rules of complex arithmetic. We demonstrate that these complex numbers combine according to Feynman's sum and product rules, with the modulus-squared yielding the probability of a sequence of outcomes.
An attempt is made to generalize the spaces of numbers and functions in order to consider certain problems in quantum mechanics, especially in the cases, where wave functions appear which do not belong to the Hilbert space L"2. Often the Soboljev - Schwartz distributions are used but they are not always the appropriate tool because they cannot be multiplied. A modification of the definition of generalized functions PSI(x vector) is proposed by particular conditions. Such conditions imposed on the wave function of a free particle seems to be the most natural by means of physics. It appears, however, that for all spaces with a real norm these conditions are contradictory. This implies together with the extension of the space of functions, an extension of the space of numbers with so called asymptotic numbers A. The four algebraic operations - addition, subtraction, multiplication and division are defined in the set A. To ...
In Graph Theory a number of results were devoted to studying the computational complexity of the number modulo 2 of a graph's edge set decompositions of various kinds, first of all including its Hamiltonian decompositions, as well as the number modulo 2 of, say, Hamiltonian cycles/paths etc. While the problems of finding a Hamiltonian decomposition and Hamiltonian cycle are NP-complete, counting these objects modulo 2 in polynomial time is yet possible for certain types of regular undirected graphs. Some of the most known examples are the theorems about the existence of an even number of Hamiltonian decompositions in a 4-regular graph and an even number of such decompositions where two given edges e and g belong to different cycles (Thomason, 1978), as well as an even number of Hamiltonian cycles passing through any given edge in a regular odd-degreed graph ...
Early effects of 100 Kilorads of X-rays on muscle cell membrane properties have been measured in sartorius muscles from Leptodactylus ocellatus. Threshold strength for rectangular current pulses increased 10% after irradiation, and action potential propagation velocity decreased 10%. Passive membrane parameters were calculated from potential responses to sub-threshold current pulses, assuming conventional cable theory. Specific membrane conductance increased to 18% after irradiation, membrane capacitance increased 14%, and length constant decreased 10% but membrane time constant was unchanged. Cell diameter decreased 5%, and resting membrane potential decreased 8%. Membrane parameters during an action potential were also evaluated by the phase-plane and current-voltage plot techniques. Irradiation significantly decreased the action potential amplitude, the excitation potential, and the maximum rates of rise and fall of membrane potential. Increases were observed in ...
This work describes the use of volatile halocarbons in a pulp mill effluent, including chloroform, bromodichloromethane, and tri- and tetrachloroethylene, as tracers for the distribution and movements of effluent currents in a receiving water bay (Jackfish Bay) on the northern shore of Lake Superior. The results indicate the simplicity and usefulness of the technique and the significantly improved resolution of effluent plume delineation over the customary use of conductance profiles. Concentration patterns of the effluent volatiles suggest counterclockwise circulation of bay water that mixes with inflowing lake water at the eastern reach of the outer bay. The distribution of volatile contaminants is governed by the thermal regime of the receiving waters. During the summer months, the effluent plume wedges between the thermocline and epilimnion, mixing into the surface waters as the distance from the input source increases. In the fall, the colder effluent plume ...
Census and environmental surveillance information on waterfowl that use the Hanford Site 200 Area waste water ponds are described and evaluated. Physical features of the ponds are discussed in relation to their use and suitability for waterfowl. Seasonal distributions observed for the years 1971 through 1974 indicate that the highest use by waterfowl occurs during the spring and fall migratory periods. Base population estimates are 300 to 400 resident waterfowl with a few tens of pairs nesting during the summer. Environmental surveillance data on "1"3"7Cs in muscle tissue are presented for the years 1971 through 1977. Comparisons are made between Columbia River and waste water pond waterfowl, between waterfowl groups, and among ponds. Waterfowl collected from ponds frequently have easily detected levels of "1"3"7Cs in muscle tissue. However, those waterfowl collected from the Columbia River seldom show a "1"3"7Cs level above that expected from worldwide fallout. ...
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 recommended because of the outdoor environment where the testing ...
We argue that closed string tachyons drive two spacetime topology changing transitions - loss of genus in a Riemann surface and separation of a Riemann surface into two components. The tachyons of interest are localized versions of Scherk-Schwarz winding string tachyons arising on Riemann surfaces in regions of moduli space where string-scale tubes develop. Spacetime and world-sheet renormalization group analyses provide strong evidence that the decay of these tachyons removes a portion of the spacetime, splitting the tube into two pieces. We address the fate of the gauge fields and charges lost in the process, generalize it to situations with weak flux backgrounds, and use this process to study the type 0 tachyon, providing further evidence that its decay drives the theory sub-critical. Finally, we discuss the time-dependent dynamics of this topology-changing transition and find that it can occur more efficiently than analogous transitions on extended supersymmetric moduli spaces, ...
We argue that closed string tachyons drive two spacetime topology changing transitions--loss of genus in a Riemann surface and separation of a Riemann surface into two components. The tachyons of interest are localized versions of Scherk-Schwarz winding string tachyons arising on Riemann surfaces in regions of moduli space where string-scale tubes develop. Spacetime and world-sheet renormalization group analyses provide strong evidence that the decay of these tachyons removes a portion of the spacetime, splitting the tube into two pieces. We address the fate of the gauge fields and charges lost in the process, generalize it to situations with weak flux backgrounds, and use this process to study the type 0 tachyon, providing further evidence that its decay drives the theory sub-critical. Finally, we discuss the time-dependent dynamics of this topology-changing transition and find that it can occur more efficiently than analogous transitions on extended supersymmetric moduli spaces, ...
The kinetics of calcium sulfate crystal growth is of importance in various fields, such as geochemistry, desalination technology, petroleum industry, and water and wastewater treatment. The seeded crystal growth rate of calcium sulfate dihydrate was measured as a function of supersaturation in NaCl electrolyte solutions from 0 to 6 m at temperatures of 25, 50, 70, and 90 C. The growth followed a second-order parabolic rate law with activation energies greater than 53 kJ/mol which suggested the surface reaction as the rate-limiting step. It was observed that the rate constant and the activation energy are solution composition dependent. The rate constant increases with NaCl concentration up to 3 molal and then begins to fall slightly. The activation energy dropped from 61 kJ/mol in the pure Ca-SO[sub 4]H[sub 2]O system to 53 kJ/mol in 3.0 m NaCl solutions. The electrolyte effect was similar to the crystal solubility behavior in aqueous electrolyte solutions ...
The covariant quark model is shown to allow a phenomenological description of the neutron electric form factor, G{sub E}{sup n}(Q{sup 2}), in the impulse approximation, provided that the wave function contains minor ({approx}3%) admixtures of the lowest energy sea-quark configurations. While that form factor is not very sensitive to whether the q{sup -} in the qqqqq{sup -} component is in the P-state or in the S-state, the calculated nucleon magnetic form factors are much closer to the empirical values in the case of the former configuration. In the case of the electric form factor of the proton, G{sub E}{sup p}(Q{sup 2}) a zero appears in the impulse approximation close to 10 GeV{sup 2}, when the q{sup -} is in the P-state. That configuration, which may be interpreted as a pion loop ('cloud') fluctuation, also leads to a clearly better description of the nucleon magnetic moments. When the amplitude of the sea-quark admixtures are set so as to describe the electric ...
This book constitutes a portion of the primary documentation for the 1992 Pacific Northwest Residential Energy Survey, Phase I. The complete 33-volume set of primary documentation provides information needed by energy analysts and interpreters with respect to planning, execution, data collection, and data management of the PNWRES92-I process. Thirty of these volumes are devoted to different ``views`` of the data themselves, with each view having a special purpose or interest as its focus. Analyses and interpretations of these data will be the subjects of forthcoming publications. Conducted during the late summer and fall months of 1992, PNWRES92-I had the over-arching goal of satisfying basic requirements for a variety of information about the stock of residential units in Bonneville`s service region. Surveys with a similar goal were conducted in 1979 and 1983. This volume contains a follow-up study of non-respondents to the original survey. The information is ...
The bright gamma-ray burst GRB050525a has been detected with the Swift observatory, providing unique multiwavelength coverage from the very earliest phases of the burst. The X-ray and optical/UV afterglow decay light curves both exhibit a steeper slope ~0.15 days after the burst, indicative of a jet break. The timing of the jet break combined with the total gamma-ray energy of the burst constrains the opening angle of the jet to be 2.5 degrees. We derive an empirical `time-lag' redshift from the BAT data of z_hat = 0.69 +/- 0.02, in good agreement with the spectroscopic redshift of 0.61. Prior to the jet break, the X-ray data can be modelled by a simple power law with index alpha = -1.2. However after 300s the X-ray flux brightens by about 30% compared to the power-law fit. The optical/UV data have a more complex decay, with evidence of a rapidly falling reverse shock component that dominates in the first minute or so, giving way to a flatter forward shock ...
The paper evaluates standardization of regulations on safety of electrical equipment for underground coal mines in the USSR. Factors increasing hazards of electrical failures of equipment in underground coal mines are analyzed: reduced lighting, increased humidity and dusts, damage caused by falling rocks or damage during haulage in underground workings, installation of electrical equipment in places easily accessible to untrained personnel. Standards on safety of electrical equipment for underground coal mining valid in the USSR are reviewed: the PIRNEh regulations on production of electrical equipment for coal mines developed by the VNIIVEh Institute, and the GOST national standards. International cooperation within the COMECON on safety of mining electrical equipment (the Interelectro Committee of the COMECON) is described. Certification of electrical equipment for coal mines is discussed on the example of electrical insulation types used in underground coal ...
Sprengel deformity is a congential malformation with usually unilateral elevation and medial rotation of the scapula. An omovertebral bone is generally present. Associated skeletal malformations are frequently present. Though functional impairment is mild, the cosmetic and psycho-social impairment can be considerable. The prognosis of early surgical therapy is good. The presented case also justifies surgical correction in the older child. (orig.) [German] Die Sprengel-Deformitaet ist eine angeborene Fehlbildung mit meist einseitiger Elevation und Medialrotation der Skapula. Meist ist ein Os omovertebrale vorhanden. Assoziierte skelettale Fehlbildungen sind haeufig. Obgleich funktionell wenig einschraenkend, ist die kosmetische und psycho-soziale Beeintraechtigung oft erheblich. Die Prognose der fruehen operativen Therapie ist gut. Der vorliegende Fall ermutigt zur operativen Therapie auch im hoeheren Kindesalter. (orig.)
Slope stability can be a major problem during the construction of surface facilities. Cutting into existing ground disturbs the mechanics of the surrounding area, which can result in landslides and rock falls. This practical reference gives you the comprehensive information you need for slope stability analysis, suitable methods of analysis with and without the use of computers, and examples of common stability problems and stabilization methods for cuts and fills. It includes detailed discussions of methods used in slope stability analysis, including the Ordinary Method of Slices, Simplified Janbu Method, Simplified Bishop Method, Spencer`s Method, other limit equilibrium methods, numerical methods, total stress analysis, effective stress analysis, and the use of computer programs to solve problems. Chapters include: General Slope Stability Concepts; Engineering Geology Principles; Groundwater Conditions; Geologic Site Exploration; Laboratory Testing ...
In this paper the authors describe the ways poststructuralist discourses assisted us to reading and reflection on data collected as part of a traditional survey-style research study. The study--generated in response to widespread concern about falling male enrolment rates at the authors' regional university--focused upon factors affecting rural male school-leavers' decisions about postschool destinations, and upon these students' attitudes to higher education. In the paper that follows, the authors contest the dominant discourses that are frequently drawn on to explain differences in male and female higher education enrolment trends. They then focus upon the features of two of the more dominant stories that students told to explain this 'difference': stories about 'real men', and stories about the value of the 'practical' over the 'theoretical'. In addition, they present another story that draws upon girls' views of higher education. Together, these stories ...
In the case where sources and receivers are not distributed on a 2-D plane, seismic tomography inversion was studied. In tomography experiments, the existing wells are generally used. In such case, sources and receivers are frequently not distributed on a 2-D plane. The 2.5-D analysis method including 2-D structure and 3-D ray-tracing was thus developed. This method is featured by less memory necessary for ray-tracing calculation, and the same algorithm for velocity determination as 2-D analysis method. In previous methods, since analysis is generally carried out by projecting sources and receivers on a certain assumed 2-D plane, it can derive correct results in the case of constant velocity and straight ray, however, in the other case, it derives incorrect results. Application of 3-D tomography requires a large amount of memory, and falls into poor convergence because of various parameters. The 2.5-D analysis method can avoid these demerits. This analysis method ...
The Task Force solicited comments on its Draft Final Report from a variety of sources. Letters were sent to over 400 individuals who had expressed interest in the interest in the Department`s radioactive waste, management programs, a notice was placed in the Federal Register, the morning session of the January 1993 meeting of the full Secretary of Energy Advisory Board was given over to discussion of the draft, and Task Force members and staff presented the effort at several professional meetings. Altogether 32 written comments were received. They are reproduced here, followed in each case by the Task Force`s response to specific suggestions made to improve the draft. (The panel did not respond to comments that simply reflected policy preferences or that praised the group`s effort.) With one exception, those specific suggestions are highlighted and given a letter designation from {open_quotes}A{close_quotes} to {open_quotes}Z{close_quotes}. The Task Force`s responses, written in the ...
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 ...
Catalytic reactions of 3-methylpentane and 2,3-dimethylbutane on HY, amorphous silica-alumina, and HZSM-5 have been studied at 500{degree}C. Both kinetic phenomena and product selectivities have been reported. Cracking reactions an HZSM-5 can be attributed to initiation through protonation occurring at Bronsted sites. Bimolecular processes leading to chain reaction via hydride transfer are restricted within the narrow pore pentasil zeolite. On HY and amorphous silica-alumina, initiation of cracking also occurs at Bronsted sited. No direct evidence was found for participation of Lewis acid sites on the catalyst framework itself. Following initiation, reactions on these catalysts are accelerated through a chain process occurring at Lewis sites generated by adsorption of product olefins at Bronsted sites. The resulting change in the dominant cracking mechanism is reflected in the product selectivity, illustrated here by a falling off in formation of molecular hydrogen ...
One of the major achievements of the magnet R&D program for the Superconducting Super Collider (SSC) is the fabrication and test of a series of 20 5-cm aperture, 15-m long dipole magnet prototypes. The ramp rate sensitivity of these magnets appears to fall in at least two categories that can be correlated to the manufacturer and production batch of the strands used for the inner-coil cables. The first category, referred to as type-A, is characterized by a strong quench current degradation at high ramp rates, usually accompanied by large distortions of the multipole fields and large energy losses. The second category, referred to as type-B, is characterized by a sudden drop of quench current at low ramp rates, followed by a much milder degradation at larger rates. The multipole fields of the type-B magnets show little ramp-rate sensitivity, and the energy losses are smaller than for the type-A magnets. The behavior of the Type-A magnets can be explained in terms ...
Tensile specimens 60 ..mu..m thick of Ni-8 at. % Si have been bombarded at 475/sup 0/C to doses of 0.1 to 0.3 dpa with either 7 MeV proton or 28 MeV alpha particle beams. Deliberate embrittlement by high temperature (700/sup 0/C) preimplantation of helium was required to produce intergranular fracture. Depth profile sputtering and analysis in a Scanning Auger Microprobe was then used to study radiation-induced segregation of silicon both at the external surfaces and at internal interfaces. The external surfaces exhibited a strongly silicon-enriched zone for the first 10 to 20 nm followed by a broad (approx.200 nm), shallow silicon-depleted region. Segregation of silicon to grain boundaries varied from interface to interface and possibly from region to region on a given interface. In general, however, depth profiles of silicon content with distance from internal boundaries showed no noticeable depletion zone and a more gradual fall-off compared to the profiles from ...
The US Department of Energy (DOE) Defense Waste Management Plan has the objective of final disposal for high-level waste (HLW) generated from defense programs. The DOE sites that generate HLW are located at the Savannah River Operations Office in Aiken, South Carolina, the Hanford site in Richland, Washington, and the Idaho Operations Office in Idaho Falls, Idaho. The purpose in the development of a quality assurance (QA) specification for organizations involved in HLW production is to establish uniform requirements that ensure that radioactive waste is converted to a waste form and canistered in such a way that it is acceptable in a federal repository licensed by the US Nuclear Regulatory Commission (NRC). A QA specification has been developed that will be applied to those activities important to certification of the product. The basic requirements are defined in national consensus standards and DOE directives. The supplemental requirements identify the QA ...
A new rapid solidification process machine will be able to produce eight-inch diameter by six-inch thick finished cavities at the rate of one per hour - a rate that will change the tooling industry dramatically. Global Metal Technologies, Inc. (GMTI) (Solon, OH) has signed an exclusive license with Idaho National Engineered and Environmental Laboratories (INEEL) (Idaho Falls, ID) for the development and commercialization of the rapid solidification process (RSP tooling). The first production machine is scheduled for delivery in July 2001. The RSP tooling process is a method of producing production level tooling in prototype timing. The process' inventor, Kevin McHugh, describes it as a rapid solidification method, which differentiates it from the standard spray forming methods. RSP itself is relatively straightforward. Molten metal is sprayed against the ceramic pattern, replicating the pattern's contours, surface texture and details. After ...
The ruthenium decontamination factor in Purex process falls quickly in successive TBP cycles. So, it is necessary to change the chemical states of RuNO complexes in order to improve DF_R_u in the uranium purification cycle. Hydrazine nitrate is being used to transform RuNO complexes into in-extractable Ru(III)and Ru(IV). However, hydrazine nitrate may be inverted into hydrazoic acid which is dangerous and can bring an unstable factor. Pretreatment using U(IV) solution provides another method to improve the decontamination of ruthenium in Purex process. 0.02 mol/lU(IV) solution can transform RuNO complexes into inextricable species by heating in water bath. The D_R_u can be decreased by a factor of 10-20. U(IV) pretreatment does not bring any harmful chemical in process. The acidity has a very large influence on the effect of pretreatment. The higher the acidity is, the worse the effect will be.
Dominating factors in plasma nitriding and plasma condition that makes nitriding possible in plasma nitriding process of metals having hard oxide film were studied. In case of stainless steel, oxide film sputtering was easier comparing to nitriding layer. Three phenomena such as sputtering of oxide layer, formation of nitriding layer and sputtering of nitriding layer occurred simultaneously. Nitriding was achieved when the formation of nitriding layer reached the peak comparing to the removal of nitriding layer after the removal of oxide layer. Situations of metallic surface of stainless steel in surface nitriding were divided into four categories and they were, situation where oxide layer remained as it is, situation where nitriding layer was formed although oxide layer remained in some part, situation where only nitriding layer was formed and situation where sputtering was carried out. It was revealed that plasma situation causing nitriding was the cathode fall ...
In view of the effect of the acidity on the oxidation potentials of nitrous, arsenous, and arsenic acids, one should expect a complex relationship between the rate of arsenic (III) to arsenic (V) and the pH of the solution. They studied the kinetics of the reaction 2AsO/sub 2//sup -/ + O/sub 2/ ..-->.. 2AsO/sub 3//sup -/ as functions of concentrations (partial pressure) of all the components of the system NaAsO/sub 2/-HCl(HClO/sub 4/)-NaNO/sub 2/-KI-H/sub 2/O-O/sub 2/ and temperature. The study of the kinetics of arsenic(III) oxidation to arsenic(V) with oxygen in the presence of sodium nitrite and iodide ions showed that the reaction rate passes through a maximum at an acid content of 1.2-2.5 M and rises in proportion to the second exponent of the sodium nitrite concentration and to the first exponent of the iodide ion concentrations and partial oxygen pressure. A fall in the temperature facilitates intensification of the process and shifting of the maximum of ...
Optische Uhren nutzen die Anregung optischer Ubergange in neutralen Atomen oder Ionen. Deren Ubergangsfrequenz liegt bei etwa 1015 Hz, also funf Groenordnungen oberhalb der Gigahertz-Schwingungen heutiger Atomuhren. Das erlaubt eine bis zu tausendmal prazisere Zeitmessung. Fur die Genauigkeit ist es entscheidend, dass der Uhrenubergang eine schmale Linienbreite besitzt und seine Frequenz nicht verschoben wird. Dazu mussen die Atome oder Ionen moglichst ungestort und genau lokalisiert sein. Deshalb basiert ein Uhrentyp auf einem kalten Ion in einer Paul-Falle, ein anderer Uhrentyp arbeitet mit vielen kalten Neutralatomen in optischen Gittern. Der Metrologie sollen optische Uhren zunachst als sekundare Realisierung der Sekunde dienen. Derzeit ermoglichen sie bereits Frequenzmessungen mit 17 ...
The E and P industry has high levels of uncertainty and risk, which oil companies attempt to quantify before embarking on each individual E and P project. However, the actual return on investment often falls well short of the hurdle rate. This discrepancy has been attributed to systemic limitations in decision analysis processes and workflow, which result in repeated underestimation of risk and overestimation of the predicted production of the project. Well designed decision analysis processes in association with clearly defined, multi-scenario analyses of significant technical uncertainties are required. However, simulation of these uncertainties is not realistic given the performance and infrastructure limitations of conventional technology (Begg et al., 2001; Floris and Peersmann, 2000). During the past five years, more than 20 companies have attempted to map the requirements of new technology that is needed to improve uncertainty assessment and decision ...
In 1970, the Federal Power Commission predicted a fall from 46% to 27% in 1990 as a result of predicted increases in the use of nuclear power. Today, the Department of Energy expects coal to supply about 50% of electricity generation in 1990. About one-eighth of the world's annual hard coal production is used to make electricity in the United States. Power stations in the country used more coal in 1979 than was produced in the whole Western Europe that year. These 405,000,000 tons of coal equivalent were burned in 1257 individual utilities with an aggregate capacity of 235,000 megawatts. There are coal-fired power plants in 43 of the 50 states. Four factors will be most important in shaping the future development of coal-based electricity: prices, conservation, environmental regulations, and national security. The price differential between coal and oil has now reached a level where it is much more economic for a United States electric utility to build and ...
The extraction of cosmological parameters from microwave background observations relies on specific assumptions about the statistical properties of the data, in particular that the p-point distributions of temperature fluctuations are jointly-normal. Using a battery of statistical tests, we assess the multivariate Gaussian nature of the Wilkinson Microwave Anisotropy Probe (WMAP) 1st year data. The statistics we use fall into three classes which test different aspects of joint-normality: the first set assess the normality of marginal (one-point) distributions using familiar univariate methods; the second involves statistics that directly assess joint-normality; and the third explores the evidence of non-linearity in the relationship between variates. We applied these tests to frequency maps, `foreground-cleaned' assembly maps and all-sky CMB-only maps. The assembly maps are of particular interest as when combined with the kp2 mask, we recreate the region used in ...
Since 1958, the AlliedSignal Federal Manufacturing and Technologies (FM and T) Metrology Department has developed measurement technology and calibration capability in four major areas of measurement: mechanical; environmental, gas, liquid; electrical (D.C., A.C., RF/microwave); and optical and radiation. The capabilities developed include unique capabilities in many areas of measurement and engineering expertise to develop measurement techniques and resolve measurement problems in these major areas. FM and T Metrology was established in 1958 to provide a measurement base for the Department of energy`s Kansas City Plant. The Metrology Engineering Department provides the expertise to develop measurement capabilities for virtually any type of measurement which falls into the broad areas listed above. The engineering staff currently averages almost 16 years of measurement experience. A strong audit function has been developed to provide a means to evaluate the ...
A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole ...
In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuumchamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility of current-enhanced SASE schemes (ESASE) recently proposed for LCLS, that ...
In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuum-chamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility of current-enhanced SASE schemes (ESASE) recently proposed for LCLS, that ...
In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuum-chamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility of current-enhanced SASE schemes (ESASE) recently proposed for LCLS, that ...
Describes investigations into flow density, angle of repose, coefficients of friction and adhesion using poor quality anthracite culm (from the 50-letie Ukrainy mine) and anthracite slurry with a high ash content (from the Tsentral'naya and Partizanskaya mines) on samples of varying moisture content (2-22%). The results show that flow properties are impaired when anthracite has a moisture content of 8.5 to 9.5%; when these anthracites are used in electric power plants they should be stored in bunkers with walls with a slope of greater than 70 degrees (or dried) to prevent sticking. Results of investigations into internal and external friction, adhesion and cohesion varied for the different samples, but the highest coefficient of internal friction was found with concrete where it increases continuously with moisture content. With rubber, PVC, St. 3 steel and stainless steel, the friction coefficient increases with moisture content at first, then gradually ...
The ruthenium decontamination factor in Purex process falls quickly with recycles of TBP. So it is necessary to change the chemical states of RuNO complexes in order to improve DF_R_u in the uranium purification cycle. The retention of RuNO complexes in TBP-kerosenelaurohydroxamic acid is observed to be quite large in our previous work. Therefore, water-soluble short chain hydroxamic acid is used as complexing agent to decrease the distribution coefficient of Ru. Hydroxamic acid can transform RuNO complexes into in-extractable species by TBP-kerosene in certain conditions. The result of cascade experiment indicates that the ruthenium decontamination can be increased by a factor of 40-50. Acidity has more influence on the effect of pretreatment. The higher acidity is, the worse the effect will be. The pretreatment is first carried out in low acidic solution, then extractive acidity is increased. In this way, the distribution of Ru can be decreased obviously. After ...
Increasingly stringent pollution regulations have spurred a broad interest in the reduction of engine emissions. Two strategies can be considered: after-treatment or engine emissions reduction. For Diesel engines, after-treatment has a high cost induced by the required technology and implementation issues. In this context, the Highly Premixed Combustion combustion mode (HP C) has emerged as a topic of major interest in recent years. It represents one of the most promising ways for new generation of CI engines using high Exhaust Gas Recirculation (EGR) rates. Experimentation on the test bench brought the proof of significant emission reduction. However, actual vehicle implementation implies frequent transient which fall far beyond steady state experimentation on the test bench. Several key challenges have to be addressed. With this combustion technology; accurate torque balancing at all engine modes is a requirement. Even slight unbalance between the cylinders can ...
Each of the two LHC injection kicker magnet systems must produce a kick of 1.3 T.m with a flattop duration variable up to 7.86 microseconds, and rise and fall times of less than 900 ns and 3 microseconds, respectively. A kicker magnet system consists of four 5 Ohm transmission line magnets with matching terminating resistors, four 5 Ohm Pulse Forming Networks (PFN) and two Resonant Charging Power Supplies (RCPS). Nine PFNs, together with associated switch tanks, and dump switch terminating resistors have been built at TRIUMF and all have been tested at high voltage (54 kV) to ensure that the performance is within specification. This paper describes the HV measurements, compares these results with low voltage measurements and analyses the pulse performance of the PFNs. The measurements are compared with results from PSpice simulations and small discrepancies between the predictions and measurements are explained.
We report the arcsecond resolution SMA observations of the $^{12}$CO (2-1) transition in the massive cluster forming region G10.6-0.4. In these observations, the high velocity $^{12}$CO emission is resolved into individual outflow systems, which have a typical size scale of a few arcseconds. These molecular outflows are energetic, and are interacting with the ambient molecular gas. By inspecting the shock signatures traced by CH$_{3}$OH, SiO, and HCN emissions, we suggest that abundant star formation activities are distributed over the entire 0.5 pc scale dense molecular envelope. The star formation efficiency over one global free-fall timescale (of the 0.5 pc molecular envelope, $\\sim$10$^{5}$ years) is about a few percent. The total energy feedback of these high velocity outflows is higher than 10$^{47}$ erg, which is comparable to the total kinetic energy in the rotational motion of the dense molecular envelope. From order-of-magnitude estimations, we suggest ...
The Fast Flux Test Facility (FFTF) is a 400-MWt, sodium-cooled reactor located on the Hanford Site near Richland, Washington, USA. The FFTF is owned by the U.S. Department of Energy and is operated by the Westinghouse Hanford Company. The FFTF was designed to test fuels and materials for use in liquid metal reactors. Since initial operation in 1982, anticipated breaches of experimental fuel pins have released fission products, including cesium, into the primary sodium. Because of its high volatility, cesium vaporizes into the cover gas space, where it condenses on components and equipment and is transported into the cover gas outlet. Because of the long half-life of "1"3"7Cs, these deposits result in long-term, local radiation levels that make contact maintenance difficult. Thus, a cesium trap was installed in FFTF to reduce the cesium level in the sodium. The trap could also permit a Run Beyond Cladding Breach (RBCB) program without compromising the sodium purity. Approximately 12 ...
The distribution of environmental tritium and the correlation coefficients between tritium concentrations in several environmental samples and the emissions of tritiated water vapor from Wolsong NPP 1 were studied. The annual mean concentrations of atmospheric HTO were in the range 1#centre dot#31-29#centre dot#2 Bq m"-"3 and the long-term atmospheric dilution factors were in the range 10"-"7-10"-"6 s m"-"3. Annual mean concentrations of tritium in ground water were in the range 19#centre dot#2-27#centre dot#9 Bq l"-"1 at N-1 and 64#centre dot#1-189 Bq l"-"1 at S-2, and were generally less than 0#centre dot#2% of MPC_w (222 kBq l"-"1). The concentrations of tritium in precipitation decreased exponentially with distance from Wolsong NPP 1, falling to current global levels at about 25 km off-site. The highest concentration of tritium in soil moisture was observed in May and June, when the relative humidity was high. The concentrations of tritium in soil moisture were ...
The uptake of "9"9Tc by trees intercepting contaminated groundwater from a radioactive waste storage site was measured to identify the major "9"9Tc pools within the woodland ecosystem and to assess the relative mobility of "9"9Tc in the existing element cycle. The highest average "9"9Tc concentrations in vegetation were found in herbaceous plants. Tree wood was the major above-ground pool for "9"9Tc because of the high concentrations in wood as well as the large amount of wood relative to other biomass at the site. Technetium was not easily leached from the trees by rainfall and was not readily extractable from forest floor leaf litter by water. The relative importance of return pathways for "9"9Tc to the forest floor was leaf fall > stemflow > throughfall, indicating that "9"9Tc was conserved by the trees. Snails and millipedes from the leaf litter layer concentrated technetium 20- and 16-fold, respectively, above levels found in the soil. Pertechnetate was ...
To make the doubly labelled water method for determining energy expenditure more applicable in a free-living population, collection of a single daily urine or breath sample would have advantages compared to a 24-hr urine collection. Coward et al. reported the use of a single daily urine sample. In the previously described study, a single urine collection and a fasting morning breath sample were collected from four men during two 21-day periods (fall, F, spring, S) while maintaining their body wts. on controlled diets (20% calories from protein, 40% from fat, 60% from CHO [F]; 20% protein, 20% fat, 60% CHO [S]). Urine and breath samples were analyzed to determine disappearance rates of D and "1"8O for up to 21 days. Values were compared with metabolizable energy intake levels (EI), with or without corrections for estimated changes in body composition assessed by several methods. Preliminary evaluations suggest that the single daily urine sample values may ...
In the course of previous composite structures test programs, the need for and the feasibility of developing analyses for scale-up effects has been demonstrated. The analysis techniques for scale-up effects fall into two categories. The first category pertains to developing analysis methods independently for a single, unique failure mode in composites, and using this compendium of analysis methods together with a global structural model to identify and predict the response and failure mode of full-scale built-up structures. The second category of scale-up effects pertains to similitude in structural validation testing. In this latter category, dimensional analysis is used to develop scale-up laws that enable extrapolation of sub-scale component test data to full-scale structures. This viewgraph presentation describes the approach taken and some developments accomplished in the first category of analysis for scale-up effects. Layup dependence of composite material ...
Two types of evacuated tube solar collectors have been operated in space heating, cooling and domestic hot water heating systems in Colorado State University Solar House I. An experimental collector from Corning Glass Works supplied heat to the system from January 1977 through February 1978, and an experimental collector from Philips Research Laboratory, Aachen, which is currently in use, has been operating since August 1978. A flat absorber plate inside a single-walled glass tube is used in the Corning design, whereas heat is conducted through a single glass wall to an external heat exchanger plate in the Philips collector. In comparison with conventional flat-plate collectors, both types show reduced heat losses and improved efficiency. For space heating and hot water supply in winter, the solar delivery efficiency of the Corning collector ranged from 49% to 60% of the incident solar energy. The portion of the space heating and domestic hot water load carried by solar energy through ...
Recent data from the northwest Gulf of Alaska reveal a coastal current which flows westward along the Kenai Peninsula (mainly within 30 km of shore), enters Shelifof Strait, and exits to the southwest of Kodiak Island. This flow, which we call the Kenai Current, has a large seasonal variation in baroclinic transport and maximum surface speed; transport is typically about 0.3 x 10/sup 6/ m/sup 3//s but exceeds 1.0 x 10/sup 6/ m/sup 3//s in fall, with concurrent speed increases from 15--30 cm/s to over 100 cm/s. The coastal flow is clearly distinct from the offshore Alaskan Stream; its seasonal signal is mainly related to a cross-shelf pressure gradient, which responds to an annual hydrological cycle. Current records from Shelikof Srait substantiante the presence of an annual signal and indicate that wind forcing has maximum effect from December through February, but it does not appear to augment flow at other times.
The analyses were carried out using real climate data for the years 1987 and 1989. The course of the indoor climate for year-round free ventilation with a constant flow volume is discussed. Numerous diagrams inform on ambient temperature, water vapour content, the condition of space air, and temperature drops below dew point. For the event of heating of the central part of the church, space air condition, the annual air humidification requirement, and the temperature field in this part of the building are described. (MSK) [Deutsch] Die Untersuchungen wurden mit aktuellen Klimadaten fuer die Jahre 1987 und 1989 durchgefuehrt. Der Verlauf des Raumklimas bei ganzjaehrig freier Klimatisierung mit konstantem Foerderstrom wird erlaeutert. Dabei wird die Raumlufttemperatur, der Wasserdampfgehalt, der Raumluftzustand sowie die Taupunktunterschreitung in zahlreichen Diagrammen aufgezeigt. Weiter werden fuer den Fall der Beheizung des Hauptraums der Kirche der ...
Chandra and XMM surveys show that the fraction of obscured AGN decreases rapidly with increasing luminosity. Although this is usually explained by assuming that the covering factor of the central engine is much smaller at luminous QSOs, the exact origin of this effect remains unknown. We perform toy simulations to test whether photo-ionisation of the obscuring screen in the presence of a strong radiation field can reproduce this effect. In particular, we create X-ray spectral simulations using a warm absorber model assuming a range of input column densities and ionization parameters. We fit instead the simulated spectra with a simple cold absorption power-law model that is the standard practice in X-ray surveys. We find that the fraction of absorbed AGN should fall with luminosity as $L^{-0.16\\pm0.03}$ in rough agreement with the observations. Furthermore, this apparent decrease in the obscuring material is consistent with the dependence of the FeK$\\alpha$ ...
This paper constructs an analytic framework for calculating the assembly of galactic disks from the collapse of gas within dark matter halos, with the goal of determining the surface density profiles. Gas parcels (baryons) fall through the potentials of dark matter halos on nearly ballistic, zero energy orbits and collect in a rotating disk. The dark matter halos have a nearly universal form, as determined previously through numerical simulations. The calculation is first carried out for a variety of pre-collapse mass distributions and rotation profiles, including polytropic spheres in hydrostatic equilibrium with the halo potential. The resulting disk surface density profiles have nearly power-law forms, with well-defined edges. This idealized scenario is generalized to include non-spherical starting states and multiple accretion events (due to gas being added to the halo via merger events). This latter complication is explored in detail and considers a log-normal ...
Following the unexpected, but safely terminated, power and flow oscillations in the LaSalle-2 Boiling Water Reactor (BWR) on March 9, 1988, the Nuclear Regulatory Commission (NRC) Offices of Nuclear Reactor Regulation (NRR) and of Analysis and Evaluation of Operational Data (AEOD) requested that the Office of Nuclear Regulatory Research (RES) carry out BWR stability analyses, centered around fourteen specific questions. Ten of the fourteen questions address BWR stability issues in general and are dealt with in this paper. The other four questions address local, out-of-phase oscillations and matters of instrumentation; they fall outside the scope of the work reported here. It was the purpose of the work documented in this report to answer ten of the fourteen NRC-stipulated questions. Nine questions are answered by analyzing the LaSalle-2 instability and related BWR transients with the BNL Engineering Plant Analyzer (EPA) and by performing an uncertainty assessment ...
The goal of assembly sequencing is to plan a feasible series of operations to construct a product from its individual parts. Previous research has thoroughly investigated assembly sequencing under the assumption that parts have nominal geometry. This paper considers the case where parts have toleranced geometry. Its main contribution is an efficient procedure that decides if a product admits an assembly sequence with infinite translations that is feasible for all possible instances of the components within the specified tolerances. If the product admits one such sequence, the procedure can also generate it. For the cases where there exists no such assembly sequence, another procedure is proposed which generates assembly sequences that are feasible only for some values of the toleranced dimensions. If this procedure produces no such sequence, then no instance of the product is assemblable. Finally, this paper analyzes the relation between assembly and disassembly sequences in the ...
The flybys of Jupiter by the Voyager spacecraft in 1979, and over two decades later by Cassini in 2000, have provided us with unique datasets from two different epochs, allowing the investigation of seasonal change in the atmosphere. In this paper we model zonal averages of thermal infrared spectra from the two instruments, Voyager 1 IRIS and Cassini CIRS, to retrieve the vertical and meridional profiles of temperature, and the abundances of the two minor hydrocarbons, acetylene (C2H2) and ethane (C2H6). The spatial variation of these gases is controlled by both chemistry and dynamics, and therefore their observed distribution gives us an insight into both processes. We find that the two gases paint quite different pictures of seasonal change. Whilst the 2-D cross-section of C2H6 abundance is slightly increased and more symmetric in 2000 (northern summer solstice) compared to 1979 (northern fall equinox), the major trend of equator to pole increase remains. For ...
Basic experimental investigations were carried out with an aqueous solution of a mixture of KOH and NaOH for use as an absorbent in absorption heat pumps. Due to its thermophysical properties this mixture allows temperature lifts from evaporator to absorber of more than 75 K (135 F) in a single-stage absorption chiller. Thermophysical and hydrodynamical properties of the solution were measured. Vapor-liquid-equilibrium data and specific heat capacities were determined for concentrations ranging from 35% up to 75% and temperatures up to 200 C (392 F). From these data the enthalpy of the solution was calculated. Additionally the crystallization temperatures, the density, and the viscosity of the solution were determined. The experimental equipment is described. The data are presented as polynomials and diagrams including experimental accuracy. An apparatus was constructed to measure heat and mass transfer coefficients of the absorption process with this solution. The apparatus is a model ...
The risk of cyber attacks on process control networks (PCN) is receiving significant attention due to the potentially catastrophic extent to which PCN failures can damage the infrastructures and commodity flows that they support. Risk management addresses the coupled problems of (1) reducing the likelihood that cyber attacks would succeed in disrupting PCN operation and (2) reducing the severity of consequences in the event of PCN failure or manipulation. The Network Security Risk Model (NSRM) developed in this article provides a means of evaluating the efficacy of candidate risk management policies by modeling the baseline risk and assessing expectations of risk after the implementation of candidate measures. Where existing risk models fall short of providing adequate insight into the efficacy of candidate risk management policies due to shortcomings in their structure or formulation, the NSRM provides model structure and an associated modeling methodology that ...
This dissertation describes a measurement of the rate ofnuclear muon capture by the proton, performed by the MuCap Collaborationusing a new technique based on a time projection chamber operating inultraclean, deuterium-depleted hydrogen gas at room temperature and 1 MPapressure. The hydrogen target's low gas density of 1 percent compared toliquid hydrogen is key to avoiding uncertainties that arise from theformation of muonic molecules. The capture rate was obtained from thedifference between the mu- disappearance rate in hydrogen--as determinedfrom data collected in the experiment's first physics run in fall2004--and the world averagefor the mu+ decay rate. After combining theresults of my analysis with the results from another independent analysisof the 2004 data, the muon capture rate from the hyperfine singlet groundstate of the mu-p atom is found to be Lambda_S = 725.0 +- 17.4 1/s, fromwhich the induced pseudoscalar coupling of the nucleon, ...
Purpose: To evaluate the success rates of the implantation of stent grafts in the treatment of peripheral aneurysms. Materials and methods: in 13 patients with 15 aneurysms at the common iliac artery (n = 6), external iliac artery (n = 1), hypogastric artery (n = 2), femoral artery (n = 2) or popliteal artery (n = 4), implantation of dacron-covered nitinol stents was performed. The patients were followed up for three to 20 months (mean, 8.8 months) with intravenous digital subtraction angiography, CT or colour-coded Doppler sonography. Results: In all cases, the aneurysm was successfully occluded after stent implantation. In one case with a popliteal aneurysm, kinking of the vessel caused thrombosis of the stent. The stent was successfully reopened. The aneurysm however, had to be surgically treated 9 months later. The primary and secondary patency rates at 6 months were 93% and 100%, respectively. Conclusion: The method described might be an alternative therapy to surgery. There are ...
The European Court of Justice has defined a clear means by which waste utilisation methods can be distinguished from waste disposal methods in a logical, well-understandable manner. With its stringent definition of ''utilisation'' this judgement points the way to quality-oriented waste management practices. We do not share the often voiced fear that this decision will lead to an increased incineration of compound wastes in industrial plants such as cement works. From the fact that, according to the decision by the European Court of Justice, wastes destined for utilisation fulfil a certain purpose and therefore, if not available in sufficient quantity must be replaced by primary raw materials, it follows that these wastes are required to fulfil specific quality criteria. This is rarely the case, if at all, with compound wastes. From the viewpoint of Luxembourg the decision by the European Court of Justice can be regarded as a positive impulse towards ...
Scour around offshore structures is well known. It is caused by the strong eddy formation at the base of the structures protruding from the sea bottom. The strong vortices result in an amplified effective shear stress working on the sea bottom surface adjacent to the structure. When the surrounding sea bottom is lowered the scour protection will end up being a cap on a small hill and when the slopes are getting too steep the scour protection will roll or slide down the sides. It will loose its cohesion and therefore its integrity. This will take place irrespective of the type of scour protection material and the type of scour protection. This report describes scour protections, which can deal with this particular problem. Such a scour protection must be able to sustain the following loads: Be able to follow the lowering of the seabed on its way down; Be resistant to edge scour (scour around the perimeter of the scour protection). The installation of scour protection is not ...
In a future power system with a high proportion of distributed and intermittent generation, it will be difficult and costly to ensure short-term security of supply if demand is unable to react to fluctuations on the supply side. At present, most power consumers in the EU, with the exception of the largest consumers such as energy intensive industries, buy their power on fixed tariffs. Fixed tariffs provide no incentives for consumers to alter their patterns of power consumption. This calls for more interaction between the supply and demand sides, which in turn would allow better matching of demand to intermittent supply. The development of cheap and reliable electronic communication technologies has made this a realistic option, so we are left with the general question of how the demand side can become more active in the future power market. Liberalisation of the wholesale power markets has introduced market-based pricing for the marginal electricity supply. Prices are set hourly, or ...
The authors report experimental results of heat transfer in the region of transition to turbulence. The augmentation was induced through deployment of periodically placed cylindrical eddy promoters in parallel plane channel flows. Eight different configurations were used. The presence of eddy promoters displaced the point of transition from Reynolds number values of 1500 for the plane channel to around 400 for the least stable case. The value of Nusselt number at the transition for eddy promoters cases was up to 2.5 times higher than the one for the plane channel at the transition. Furthermore, the lower the transition Reynolds number, the higher the Nusselt number at the transition. For the cases where the diameter of the promoters was small and/or the pitch large, the heat transfer results in the transition region were consistent with values obtained from the Reynolds analogy when the analogy was ...
Heat transfer enhancement in a heat exchanger tube by installing a baffle is reported. The effect of baffle size and orientation on the heat transfer enhancement was studied in detail. Three different baffle arrangements were considered. The results show that for the vertical baffle, an increase in the baffle height causes a substantial increase in the Nusselt number but the pressure loss is also very significant. For the inclined baffles, the results show that the Nusselt number enhancement is almost independent of the baffle inclination angle, with the maximum and average Nusselt number 120% and 70% higher than that for the case of no baffle, respectively. For a given baffle geometry, the Nusselt number enhancement is increased by more than a factor of two as the Reynolds number decreased from 20,000 to 5000. Simulations were conducted by introducing another baffle to enhance heat ...
The onset of double-diffusive convection in a couple-stress fluid-saturated horizontal porous layer is studied using linear and weak nonlinear stability analyses. The modified Darcy equation that includes the time derivative term and the inertia term is used to model the momentum equation. The expressions for stationary, oscillatory and finite-amplitude Rayleigh number are obtained as a function of the governing parameters. The effect of couple-stress parameter, solute Rayleigh number, Vadasz number and diffusivity ratio on stationary, oscillatory and finite-amplitude convection is shown graphically. It is found that the couple-stress parameter and the solute Rayleigh number have a stabilizing effect on stationary, oscillatory and finite-amplitude convection. The diffusivity ratio has a destabilizing effect in the case of stationary and finite-amplitude modes, with a dual effect in the case of ...
The onset of double-diffusive convection in a couple-stress fluid-saturated horizontal porous layer is studied using linear and weak nonlinear stability analyses. The modified Darcy equation that includes the time derivative term and the inertia term is used to model the momentum equation. The expressions for stationary, oscillatory and finite-amplitude Rayleigh number are obtained as a function of the governing parameters. The effect of couple-stress parameter, solute Rayleigh number, Vadasz number and diffusivity ratio on stationary, oscillatory and finite-amplitude convection is shown graphically. It is found that the couple-stress parameter and the solute Rayleigh number have a stabilizing effect on stationary, oscillatory and finite-amplitude convection. The diffusivity ratio has a destabilizing effect in the case of stationary and finite-amplitude modes, with a dual effect in the case of ...
High quality graphene sheets are synthesized through efficient oxidation process followed by rapid thermal expansion and reduction by H2. The number of graphene layers is controlled by tuning the oxidation degree of GOs. The higher the oxidation degree of GOs is getting, the fewer the numbers of graphene layers can be obtained. The material is characterized by elemental analysis, thermo-gravimetric analysis, scanning electron microscopy, atomic force microscopy, transmission electron microscopy and Fourier transform infrared spectroscopies. The obtained graphene sheets with single, triple and quintuplicate layers as anode materials exhibit a high reversible capacity of 1175, 1007, and 842 mA h g-1, respectively, which show that the graphene sheets with fewer layers have higher reversible capacity. -- Graphical abstract: The typical TEM images of the graphene sheets derived from GO3(a), GO2(b) and GO1(c). Display Omitted Highlights: ? With the ...
Survival curves were constructed from dose-incidence curves for apoptosis in the crypts of mouse small intestine, using the number of apoptotic cells after high doses (N{sub M}) as maximum cell population size. The mean lethal doses (D{sub 0}) for the dose range 0-0.5 Gy were calculated for each time of day. A circadian rhythm in both D{sub 0} and N{sub M} values was detected, indicating that both the number and sensitivity of radiation-induced apoptosis were changing throughout the day. (author).
During spring and autumn, the total number of amoebae and the number of acanthamoeba species able to grow at 37 degrees C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vito cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters.
Neutron deficient nuclei with mass numbers A {approx} 90 and 40 {<=} Z {<=} 44 have been studied making use of the Osiris and Nordball spectrometers. The high spin states of these nuclei and their electromagnetic decay properties are compared to shell model calculations based on the core {sup 88}Sr and using different parametrizations of the residual interaction. The dependence of the mean square deviations of experimental and theoretical level energies, branching ratios, and transition probabilities on the neutron numbers N = 46-50 and the validity of seniority as a good quantum number are discussed. (orig.).
This paper is devoted to investigate the influences of thermal dispersion and magnetic field on a hot semi-infinite vertical porous plate embedded in a saturated Darcy-Forchheimer-Brinkman porous medium. The coefficient of thermal diffusivity has been assumed to be the sum of the molecular diffusivity and the dynamic diffusivity due to mechanical dispersion. The effects of transverse magnetic field parameter (Hartmann number Ha), Reynolds number Re (different velocities), Prandtl number Pr (different types of fluids) and dispersion parameter on the wall shear stress and the heat transfer rate are discussed.
We study uncertainties surrounding competition on business networks and board games. We investigate these uncertainties using concepts of fuzzy logic and game theory. We investigate how the payoff of the players is affected by a number of factors. These include the level of connectivity or number of links, the number of competitors, possible constraints on the networks and on the boards, as well as choice of strategy adopted by competitors. We introduce one fuzzy player in the game. This player uses fuzzy rules to make strategic decisions. We introduce learning to train and analyze how the fuzzy player adapts over time during the game.
"ID# ","Measurement ID Number " "DATE ","Date " "JDATE ","Julian Date " "TIME ", "Local Time " "GMT ","Greenwich Mean Time " "BAND ","Dielectric Probe Band ...
... Accession Number : ADD815206. Title : Waterjet Cutting System Adds Value to Titanium Parts. Descriptive Note : Journal article. Corporate Author : ...
... Accession Number : AD0749455. Title : Uptake and Retention of Adenine Moiety by Stored Human Red Blood Cells. Descriptive Note : Interim rept.,. ...
PurposeThe purpose was to determine whether semantic set size, a measure of the number of semantic neighbors, influenced word learning, and whether the influence...Full Text Available
Momentum transfer through an air-water interface was studied in a horizontal rectangular channel through experimental and numerical analysis. The liquid flow Reynolds numbers, based on hydraulic diameters, were 11500 and 17000. The air flow Reynolds number varied from 0 to 3260. In experiments, velocity distribution was measured by hot-film and hot-wire probes. The effect of the liquid flow Reynolds number and the direction of interfacial shear stress was investigated by performing the cocurrent and countercurrent experiments. The modified k-{epsilon} model was able to reproduce these experimental results qualitatively. The range of applicability of the modified k-{epsilon} model was also discussed. (author).
Momentum transfer through an air-water interface was studied in a horizontal rectangular channel through experimental and numerical analysis. The liquid flow Reynolds numbers, based on hydraulic diameters, were 11500 and 17000. The air flow Reynolds number varied from 0 to 3260. In experiments, velocity distribution was measured by hot-film and hot-wire probes. The effect of the liquid flow Reynolds number and the direction of interfacial shear stress was investigated by performing the cocurrent and countercurrent experiments. The modified k-#epsilon# model was able to reproduce these experimental results qualitatively. The range of applicability of the modified k-#epsilon# model was also discussed. (author).
... changes in the wing shock/ separation patterns throughout ... to Reynolds number and tunnel flow quality before ... AGARD Conference Proceedings No ...
While both sperm number and quality are now recognized to be important in determining the outcome of sperm competition, very few studies have experimentally assessed the influence of these two parameters simultaneously. We studied the effect of sperm quality and number on competitive fertilization success in an internal-fertilizing fish, the guppy (Poecilia reticulata), which is characterized by high levels of sperm competition. We artificially inseminated virgin females with varying proportion of sperm from two competing males, while holding constant the total number of sperm transferred to the female. Sperm morphology and sperm swimming velocity were also determined prior to insemination. The paternity outcome of sperm competition trials was assessed through molecular analyses of the res...
Within the cardiac cell, the movements of calcium ions are tightly regulated by a number of regulatory proteins including pumps, and channels. The sarcoplasmic reticulum (SR) is in large part...Full Text Available
and the estimated parameter covariance matrix is. 5. (25) where p in this case is the number of elements in the vector . The parameter standard errors, ?, ...
... Accession Number : ADD135818. Title : Performance of Titanium in Flue Gas Desulfurization Scrubber Systems,. Descriptive Note : Journal Article,. ...
by the radionuclide X-ray fluorescence analysis into several groups according to the atomic number of the determined element. Table I documents this. ...
The kWh model finds the kWh outputs of each plant and reservoir capacities of hydro and pumped storage plants and minimizes the sum of fixed charges for constructing the reservoirs and generating facilities, also the fuel costs of thermal and nuclear plants. It is a linear programming problem whose constants are represented by nonlinear functions of kW running capacity of each plant. The optimal pattern of nuclear and thermal units is found by solving the linear programming problem derived for the pumped storage and hydroplants. Excluding the upper bound constraints, the number of constraint equations are few and do not increase with the number of units, although the number of variables increases. The computing time increases only in proportion to the number of groupings of generating units. Sensitivity analysis can be done easily. The detailed operational behavior of each generating unit can be taken ...
The available nuclear structure information for all nuclei with mass number A=242 is presented. Various decay and reaction data are evaluated. Adopted data, levels, spin and parity assignments are given.
a large number of polycrystalline materials, has the fot_ of the. Manson-Coffin- Basquin equation, wherein the exponents of the two power law terms are given ...
Lens-induced glaucoma comprises a number of different glaucomatous processes occurring in the elderly that share in common the role of the crystalline lens in the mechanism of increase in intraocular...Full Text Available
About a third of the population in the cities of developing countries live in slums and shanty towns. By the year 2000 it is estimated that this number will grow to 2200 million, and by 2025 about 57%...Full Text Available
... Accession Number : ADD431225. Title : Influence of Fiber Loading on Thermal Ablation of PTFE,. Corporate Author : Personal Author(s) : Letson,KN. ...
Background An increasing number of people have access to the Internet, and more people are seeking tobacco cessation resources online every year. Despite the...Full Text Available
... 1768 1475 360 to 3400 ... The TSC provided an independent assessment of SA based on ... Complexity of Situation Degree of complication (number of ...
A number of biological agents are available or being investigated for the treatment of asthma and rhinitis. The safety profiles of these biologic agents, which may modify allergic and immunological...Full Text Available
Genomic imprinting refers to the parent-of-origin-specific epigenetic marking of a number of genes. This epigenetic mark leads to a bias in expression between maternally and paternally inherited imprinted...Full Text Available
Motivation: DNA sequences can be represented by sequences of four symbols, but it is often useful to convert the symbols into real or complex numbers for further analysis. Several mapping...Full Text Available
Oberpfaffenhofen, Pedel"al aepublic of Gel1lany. A large number of European scientists have provided ex~eri- ments that will be cooducted in the Material ...
Gastric acid hypersecretory states are a group of disorders characterized by basal hypersecretion of gastric acid and historically include a number of disorders associated with hypergastrinemia,...Full Text Available
This paper addresses fuel cycle cost comparisons for a generic 10 MW reactor with HEU aluminide fuel and with LEU oxide and silicide fuels in several fuel element geometries. The intention of this study is to provide a consistent assessment of various design options from a cost point of view. Fuel cycle cost benefits could result if a number of reactors were to utilize fuel elements with the same number or different numbers of the same standard fuel plate. Data are presented to quantify these potential cost benefits. This analysis shows that there are a number of fuel element designs using LEU oxide or silicide fuels that have either the same or lower total fuel cycle costs than the HEU design. Use of these fuels with the uranium densities considered requires that they are successfully demonstrated and licensed.
Francisella tularensis is a Gram-negative bacterium capable of causing the zoonotic disease tularaemia in a large number of mammalian species and in arthropods. F. tularensis...Full Text Available
An experimental study was performed to investigate the heat transfer characteristics of the mixed convection flow through a horizontal rectangular channel where open-cell metal foams of different pore densities (10, 20 and 30 PPI) were situated. A uniform heat flux was applied at all of the bounding walls of the channel. For each of three values of the uniform heat flux, temperatures were measured on the entire surfaces of the walls. Results for the average and local Nusselt numbers are presented as functions of the Reynolds and Richardson numbers. The Reynolds number based on the channel height of the rectangular channel was varied from 600 to 33000, while the Richardson number ranged from 0.02 to 103, extending over forced, mixed and natural convection. Second important parameter that in...
Present paper is performed to investigate the heat and exergy transfer characteristics of forced convection flow through a horizontal rectangular channel where open-cell metal foams of different pore densities such as 10, 20 and 30PPI (per pore inches) were situated. All of the bounding walls of the channel are subjected to various uniform heat fluxes. The pressure drop and heat transfer characteristics are presented by two important parametric values, Nusselt number (NuH) and friction factor (f), as functions of Reynolds number (ReH) and the wall heat flux (q). The Reynolds number (ReH) based on the channel height of the rectangular channel is varied from 600 to 33 000, while the Grashof number (GrDh) ranged from approximately 105-107 depending on q. Based on the experimental data, new em...
A growing number of environmental toxicants found in pesticides, herbicides, and industrial solvents are believed to have deleterious effects on development by disrupting hormone-sensitive processes....Full Text Available
... of the loop filter based on ... algorithms, including delta-sigma approaches, routinely uses double-precision floating point number representations for ...
Diabetes mellitus is a metabolic disorder that leads to the development of a number of complications. The etiology of each diabetic complication is undoubtedly multifactorial. We will focus...Full Text Available
... assets, particularly against ballistic missiles with weapons of mass ... more con- ventional missile and gun weapon systems. ... Similarly, space-based ...
Due to the use of a limited number of species and subchronic exposures, current ecological hazard assessment processes can underestimate the chronic toxicity of environmental contaminants resulting...Full Text Available
Background Increasing numbers of cancer patients are using the Internet, but little is known about their attitudes toward online health care.Full Text Available
... earns money through receiving protection funds from embattled ... relationship between the TTP and LI ... relevant considering that Pakistan's military is ...
replacing the KDP crystal, and introducing computer programs for accumulation of an almost unlimited number of frames. The calibration procedure using solar ...
Budding yeasts are highly suitable for aging studies, because the number of bud scars (stage) proportionally correlates with age. Its maximum stages are known ...Full Text Available
... Standards Validation Group National Computer Systems Laboratory National Institute of Standards and Technology ... STANDARD. ... (See test Ci )i3A. ...
The ability of a number of mycobacteria and some of their components to activate complement was examined. Mycobacterium bovis BCG (Glaxo strain), Mycobacterium leprae, Mycobacterium lepraemurium, and...Full Text Available
In this paper, the unsteady MHD free convection heat and mass transfer of viscous fluid flowing through a Darcian porous regime adjacent to a moving vertical semi-infinite plate under Soret and Dufour effect have been examined. Viscous dissipation effects are included in the energy equation. A uniform magnetic field is applied transversely to the direction of the flow. The differential equations governing the problem have been transformed by a similarity transformation into a system of non-dimensional differential equations which are solved numerically by element free Galerkin method. The influence of Grashof number (Gr), magnetic parameter (M), heat absorption parameter (Q), permeability parameter (K), Schmidt number (Sc), Soret number (Sr), and Dufour number (Du) on the velocity, tempera...
BackgroundMitochondrial DNA (mtDNA) is being analyzed by an increasing number of laboratories in order to investigate its potential role as an active marker of tumorigenesis...Full Text Available
...The system recognises the name and confirms it before it starts to dial. To stop the number being dialled say 'cancel'. If ...of the conference : Press the Recall 'R' button and listen for holding dial tone. Select extension or outside number of the person to ...who is going to join the conference Press Recall 'R' to receive dial tone and select '*' and '4'. The call is ...line is faulty and should be reported to the switchboard operators by dialling '0' and giving full details of the fault, the extension ...
Because of good thermal insulation of advanced energetic buildings and their good airtightness the air hygiene is insufficient. A normal ventilation behaviour by window opening consumes too much heating energy. A calculation method is shown taking into account a required air change number, flow rate and indoor air quality as thermal comfort in the rooms occupied by different number of persons. (GL)
In contrast to plants based on formed coal where, for the purposes of calculating sorbent volume, only one activated charcoal design can be used in a filter layer, powder sorbent technology enables two variations to be used. This can be either a mixture of a number of different activated charcoal forms in one and the same filter layer, or the combination of a number of filter layers on top of each other, each containing a different activated charcoal form, in one and the same construction unit.
The authors solve the two-dimensional stefan problem of solidification in a half-space, where the heat flux at the wall is a slightly varying function of positioning along the wall, by means of a large Stefan number approximation (which turns out to be equivalent to a small time solution), and then by means of the Heat Balance Integral Method, which is valid for all time, and which agrees with the large Stefan number solution for small times. A representative solution is given for a particular form of the heat flux perturbation.
The steady-state advective flow in a long horizontal rectangular channel with rigid adiabatic boundaries in the presence of a uniform longitudinal pressure gradient is investigated. The stability of this flow with respect to perturbations of various types is studied. The dependence of the critical Rayleigh number on the Prandtl number is found for various aspect ratios.
Given a countable set X (usually taken to be the natural numbers or integers), an infinite permutation, \\pi, of X is a linear ordering of X. This paper investigates the combinatorial complexity of infinite permutations on the natural numbers associated with the image of uniformly recurrent aperiodic binary words under the letter doubling map. An upper bound for the complexity is found for general words, and a formula for the complexity is established for the Sturmian words and the Thue-Morse word.
In this paper we study the enumeration and the construction, according to the number of ones, of particular binary words avoiding a fixed pattern. The growth of such words can be described by particular jumping and marked succession rules. This approach enables us to obtain an algorithm which constructs all binary words having a fixed number of ones and then kills those containing the forbidden pattern.
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) ...
We study heavy physics effects on the Higgs production in #gamma##gamma# fusion using the effective Lagrangian approach. We find that the effects coming from new physics may enhance the standard model predictions for the number of events expected in the final states b-barb, WW, and ZZ up to one order of magnitude, whereas the corresponding number of events for the final state t-bart may be enhanced up to two orders of magnitude.
BackgroundThe beta-defensin gene cluster (DEFB) at chromosome 8p23.1 is one of the most copy number (CN) variable regions of the human genome. Whereas individual DEFB CNs have been...Full Text Available
Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively.
The spontaneous evolution from ultracold Rydberg atoms to plasma is investigated in a caesium MOT by using the method of field ionization. The plasma transferred from atoms in different Rydberg states (n=22-32) are obtained experimentally. Dependence of the threshold time of evolving to plasma and the threshold number of initial Rydberg atoms on the principal quantum number of initial Rydberg states is studied. The experimental results are in agreement with hot-cold Rydberg-Rydberg atom collision ionization theory. (authors)
A numerical study of a natural convection in a rectangular cavity with the low-Reynolds-number differential stress and flux model is presented. The primary emphasis of the study is placed on the investigation of the accuracy and numerical stability of the low-Reynolds-number differential stress and flux model for a natural convection problem. The turbulence model considered in the study is that developed by Peeters and Henkes (1992) and further refined by Dol and Hanjalic (2001), and this model is applied to the prediction of a natural convection in a rectangular cavity together with the two-layer model, the shear stress transport model and the time-scale bound #upsilon#"2-f model, all with an algebraic heat flux model. The computed results are compared with the experimental data commonly used for the validation of the turbulence models. It is shown that the low-Reynolds-number differential stress and flux model predicts ...
The phenomenon of runaway electrons (REs) at high values of the ratio field intensity/gas number density {ital E}/{ital N} and {ital N} up to the Loshmidt number {ital N}{sub {ital L}}{approx_equal}2.7{times}10{sup 19} cm{sup {minus}3} is described. REs are shown to govern the breakdown and discharges at such condition. {copyright} {ital 1996 American Institute of Physics.}
Granted patents are an important source of information on the potential commercialization of augmented heat transfer technology. This report presents a bibliography of US patents pertinent to that technology. The total number of patents cited is 321. They are presented in three separate lists: by patent number, alphabetically by first inventor, and by augmentation techniques (with secondary arrangement according to mode of heat transfer).
The relative potencies of 20 polychlorinated biphenyls (PCBs) were studied in a chicken embryo hepatocyte system. The 20 congeners were selected according to a full 2{sup 4}-factorial design based on the principal properties of all 154 tetra- through heptachlorinated PCBs. The principal properties were obtained using principal component analysis (PCA) on a multitude of different physico-chemical properties of the PCBs. Toxic equivalency factors (TEFs) were determined for seven out of the twenty PCB congeners, viz. PCB{number_sign}41, PCB{number_sign}60, PCB{number_sign}78, PCB{number_sign}126, PCB{number_sign}169, PCB{number_sign}190, and PCB{number_sign}193, which elicit measurable catalytic ethoxyresorufin-O-deethylase (EROD) activity in the chicken hepatocytes. A multivariate quantitative structure-activity relationship (QSAR) was ...
Stable and accurate numerical analytical method even at high Rayleigh numbers is desired, and in addition flexibility and economical efficiency are very important for numerical analysis. Unsteady flows of natural convention in a square cavity are investigated using the GSMAC (generalized and simplified marker and cell) finite-element method at high Rayleigh numbers from 10 {sup 6} to 10 {sup 8}. Validities of the multi-pass algorithm and BTD (balancing tensor diffusivity), which are highly accurate solutions for finite-element method, are investigated by introducing them to the GSMAC finite-element method. As the result, it was found that the multi-pass algorithm has little effect for the GSMAC finite-element method. The steady solutions at the Rayleigh numbers of 10 {sup 5} and 10 {sup 7} agreed well with the bench mark solutions and numerical solutions. Complex transient phenomena at Rayleigh numbers ...
The unsteady flow and heat transfer are simulated using LES and DNS for a channel with two angled ribs as a vee-shaped vortex generator to augment heat transfer. The vortex generators are attached on the bottom wall of the channel and their angles in respect to the main flow are between 10"o and 30"o. The Prandtl number is 0.71 and the Reynolds numbers based on the inflow velocity and the height of channel are from 200 to 2000. Based on the results of this work, the variations of the Nusselt number, pressure coefficient, bulk temperature, friction factor and Colburn factor with the Reynolds numbers and the incidence angles are provided. The relation between the key parameters of the velocity (friction factor f) and thermal (Colburn factor J) boundary layers is calculated for all cases and their values are compared with the predicted values by the Chilton-Colburn analogy. A comparison between the DNS and ...
45{number_sign} steel, which has good mechanical strength and is relatively cheap, is a common constituent in industrial components, such as precision gears, piston columns of oil pumps, and so on. However, since the working environment of these industrial parts is sometimes quite harsh and unforgiving, they are vulnerable to wear and corrosion. Replacing 45{number_sign} steel with stainless or alloy steel increases the cost significant, and a better alternative is to improve its surface properties and lifetime using plasma immersion ion implantation (PIII). The authors have devised a variety of treatment processes using PIII, including radio-frequency (RF) plasma nitriding, RF plasma nitriding and nitrogen PIII, Ti deposition in conjunction with nitrogen PIII (IBED), as well as Cr deposition followed by nitrogen PIII (IBED). To assess the efficacy of the processes, the microhardness and mass loss due to wear were measured for both the ...
A suspension of bone marrow cells from femurs of female (CBA . C57B1)F1 mice was exposed to 2450 MHz CW microwaves in a specially designed waveguide exposure system. The temperature of the suspension rose, during exposure to microwaves, from 20/sup 0/C to 45/sup 0/C, and at an interval within 20/sup 0/C to 45/sup 0/C the number of haemopoietic stem cells (CFUs) was determined by the spleen exocolony method. The time of exposure of bone marrow cells to each temperature studied was 20 s. Control suspensions of bone marrow cells were exposed to a water bath temperature. There were no significant effects of the CFUs with the water bath temperature, while after exposure to microwaves the number of spleen colonies was elevated with a nadir at the temperature of 37/sup 0/C. With a microwave-induced increase of the temperature above 41/sup 0/C the number of CFUs in the bone marrow suspension decreased. The increase in the ...
A salient facet of Axelrod's model for culture dissemination or social influence is the existence of many multicultural absorbing states. The dependence of the number $C$ of different, coexisting cultures on the size $A$ of the territory or, equivalently, on the number of agents -- the culture-area relation -- is investigated through extensive simulations. This relation exhibits a strong qualitative dependence on the two parameters of the model, namely, the number $F$ of culture features and the number $q$ of values that each feature can take on. We find that a non-monotonous culture-area relation, for which the number of cultures decreases when the area grows beyond a certain size, occurs for $q$ smaller than a threshold value $q_c = q_c (F)$ provided that $F \\geq 3$. In the limit of infinite area, this threshold value signals the onset of a discontinuous phase transition between ...
Both linear and weakly nonlinear stability analyses are performed to study thermal convection in a rotating couple-stress fluid-saturated rigid porous layer. In the case of linear stability analysis, conditions for the occurrence of possible bifurcations are obtained. It is shown that Hopf bifurcation is possible due to Coriolis force, and it occurs at a lower value of the Rayleigh number at which the simple bifurcation occurs. In contrast to the nonrotating case, it is found that the couple-stress parameter plays a dual role in deciding the stability characteristics of the system, depending on the strength of rotation. Nonlinear stability analysis is carried out by constructing a set of coupled nonlinear ordinary differential equations using truncated representation of Fourier series. Sub-critical finite amplitude steady motions occur depending on the choice of physical parameters but at higher rotation rates oscillatory convection is found to be the preferred ...
Mixed convection heat transfer from longitudinal fins inside a horizontal channel has been investigated in the natural convection dominated region for a wide range of Rayleigh numbers and different fin heights and spacings. An experimental parametric study was made to investigate effects of fin spacing, fin height and magnitude of heat flux on mixed convection heat transfer from rectangular fin arrays heated from below in a horizontal channel. The optimum fin spacing to obtain maximum heat transfer has also been investigated. During the experiments constant heat flux boundary condition was realized and air was used as the working fluid. The velocity of fluid entering channel was kept nearly constant (0.02 {<=} w{sub in} {<=} 0.025 m/s) using a flow rate control valve so that Reynolds number was always about Re = 250. Experiments were conducted for modified Rayleigh numbers 3 x 10{sup 7} < Ra{sup *} ...
Collaborative Filtering (CF) is a popular method for personalizing product recommendations for e-Commerce and customer relationship management (CRM). CF utilizes the explicit or implicit product evaluation ratings of customers to develop personalized recommendations. However, there has been no in-depth investigation of the parameters of CF in relation to the number of ratings on the part of an individual customer and the total number of ratings for an item. We empirically investigated the relationships between these two parameters and CF performance, using two publicly available data sets, EachMovie and MovieLens. We conducted three experiments. The first two investigated the relationship between a particular customer?s number of ratings and CF recommendation performance. The third experim...
Turbulent flow in a 2D channel with repeated rectangular rib roughness was numerically simulated using a low Reynolds number form of the k-epsilon turbulence model. Friction factors and average Stanton numbers were calculated for various pitch to rib height ratios and bulk Reynolds numbers. Comparisons with experiment were generally adequate, with the predictions of friction superior to those for heat transfer. The effect of variable properties for channel flow was investigated, and the results showed a greater effect for friction than for heat transfer. Comparison with experiment yielded no clear conclusions. The turbulence model was also validated for a related problem, that of flow downstream of an abrupt pipe expansion.
A descriptive model and design procedure for the DC electromagnetic flow coupler is developed based on a quasi-one-dimensional analysis previously developed for the DC electromagnetic pump. It is shown that for a particular flow coupler geometry, the total efficiency and the pressure gradients through the pump and generator depend on two parameters - the Hartmann number and the ratio of the pump flow rate to generator flow rate. Thus, for a fixed Hartmann number the efficiency depends only on the flow ratio. However, for a fixed pressure rise through the pump it is shown that the efficiency depends only on the Hartmann number. Nomographs showing the operating characteristics and critical design points are presented. Example calculations for a full-size unit, suitable for use in a liquid-metal cooled fast breeder reactor, are also discussed using the design nomographs.
This study identifies new information on the recent distribution of an invasive bird species, the Cattle Egret Ardea ibis, in Algeria. Breeding and wintering distributions as well as breeding numbers were obtained from large-scale surveys in 1999 and 2007, and from historical data. Between 1999 and 2007, the total number of colonies found increased from 51 to 87, and most were located in the northern part of the country. The breeding distribution area, confined to the coastal areas in the 1970s, has shifted further south, and reached the northern part of the Sahara since the 2000s. Most colonies were established during the period 1980-1995. The oldest colonies were generally larger than the recent ones. The number of colonies increased by 83% between 1999 and 2007 in the 12 administrative ...
Simple, one-zone models for inhomogeneous chemical evolution of the Galactic halo are used to predict the number fraction of zero-metallicity, Population III stars, which currently is empirically estimated at < 4e-4. These analytic models minimize the number of free parameters, highlighting the most fundamental constraints on halo evolution. There are disagreements of at least an order of magnitude between observations and predictions in limiting cases for both homogeneous Simple Model and Simple Inhomogeneous Model (SIM). Hence, this demonstrates a quantitative, unambiguous discrepancy in the observed and expected fraction of Population III stars. We explore how the metallicity distribution of the parent enrichment events f(z_0) drives the SIM and predictions for the Population III fraction. The SIM shows that the previously-identified "high halo" and "low halo" populations are consistent with a continuous evolutionary progression, and ...
We obtain conformal invariant topological field theories with N = 2 supersymmetry by twisting Sevrin, Troost and Van Proeyen's SU(2) x SU(2) x U(1) extended N = 4 superconformal field theories. We expect that the number of physical states is finite although the original N = 4 theories have continuous spectra. It is shown that the number of physical states is actually finite when the central charge c < 6 in the corresponding N = 4 theories. The physical states inherit the structure of the chiral ring in N = 2 superconformal minimal series which is obtained by the reduction from N = 4 theories. We also show that the algebra contains the topological N = 4 superconformal algebra as subalgebra. Therefore a closed set of a finite number of physical states in the topological N = 1 superconformal algebra can also be obtained. (orig.).
A solvent extraction method was developed to obtain methanolic extracts rich in antioxidants from banana peel. Central composite design ''2^3+star'' and response surface methodology were used in order to optimise the number of extraction steps, extraction temperature and extraction time. The number of extractions was statistically the most significant factor in scavenging activity against both DPPH? and ABTS?^+ radicals and in the inhibition of TBARS formation, while the extraction temperature had an important impact on the capacity to prevent b-carotene bleaching. However, the effect of the extraction time on antioxidant activity was less important. The optimum values of the factors that influence the capacity to scavenge DPPH? and ABTS?^+ radicals or to inhibit b-carotene bleaching were ...
Coordination of CoCl2 solutions to the silica polyamine composite, WP-1, made with the branched polymer polyethylenimine (PEI) shows irreversible binding resulting from surface oxidation of the Co2+-Co3+. This is not the case for the silica polyamine composite BP-1 made with the linear polymer polyallylamine where reversible binding and no oxidation is observed. These observations suggested that oxidation of the cobalt was related to the greater coordination number available with the branched polyamine relative to the linear polyamine. A study of the kinetics of cobalt binding to WP-1 indicated initial loading of Co2+ at relatively low coordination number followed by desorption of Co2+ leading to oxidation and irreversible binding. Exclusion of oxygen from the composite-cobalt solution mix...
Mining association rules is a popular and well researched method for discovering interesting relations between variables in large databases. A practical problem is that at medium to low support values often a large number of frequent itemsets and an even larger number of association rules are found in a database. A widely used approach is to gradually increase minimum support and minimum confidence or to filter the found rules using increasingly strict constraints on additional measures of interestingness until the set of rules found is reduced to a manageable size. In this paper we describe a different approach which is based on the idea to first define a set of ``interesting'' itemsets (e.g., by a mixture of mining and expert knowledge) and then, in a second step to selectively generate rules for only these itemsets. The main advantage of this approach over increasing thresholds or filtering rules is that the number of ...
We introduce reflexive polytopes of index l as a natural generalisation of the notion of a reflexive polytope of index 1. These l-reflexive polytopes also appear as dual pairs. In dimension two we show that they arise from reflexive polygons via a change of the underlying lattice. This allows us to efficiently classify all isomorphism classes of l-reflexive polygons up to index 200. As another application, we show that any reflexive polygon of arbitrary index satisfies the famous "number 12" property. This is a new, infinite class of lattice polygons possessing this property, and extends the previously known sixteen instances. The number 12 property also holds more generally for l-reflexive non-convex or self-intersecting polygonal loops. We conclude by discussing higher-dimensional examples and open questions.
This study is an attempt to measure the quantities of elements in a composite by irradiating that composite with #gamma#-rays of various energies and detecting the transmitted radiation through the composite. A previous knowledge of the number of the elements and their attenuation coefficients is required. The quantities are calculated by solving the matrix of a linear system of equations. A computer program was developed to select the best combinations of the available energies. Five criteria were established to determine these energy combinations: (i) the determinant of the attenuation coefficient matrix; (ii) the condition number, (iii) the number of times the solution of the matrix leads to acceptable results; (iv) the indicator, (a new concept); (v) the standard deviations of the results. The intended application of this technique in medicine is to measure the bone mineral content of the skeleton. An examination of the ...
Finding interesting rule in the sixth strategy step about threshold control on generalized relations in attribute oriented induction, there is possibility to select candidate attribute for further generalization and merging of identical tuples until the number of tuples is no greater than the threshold value, as implemented in basic attribute oriented induction algorithm. At this strategy step there is possibility the number of tuples in final generalization result still greater than threshold value. In order to get the final generalization result which only small number of tuples and can be easy to transfer into simple logical formula, the seventh strategy step about rule transformation is evolved where there will be simplification by unioning or grouping the identical attribute. Our approach to measure interesting rule is opposite with heuristic measurement approach by Fudger and Hamilton where the more complex concept ...
A numerical investigation for forced convection in a constant-temperature parallel plate channel with porous cavity and block alternately emplaced on the bottom plate is presented in this work. The Brinkman-Forchheimer-extended Darcy model, which accounts for the effects of impermeable boundary and inertia, is used to characterize the flow field inside the porous region. Solutions of the coupled governing equations are carried out through the stream function-vorticity analysis. The characteristics of fluid flow and forced convection heat transfer have been obtained by the examinations of various governing parameters, such as the Reynolds number, Darcy number, inertial parameter, Prandtl number, and two geometric parameters. Several interesting phenomena such as the heat transfer augmentation in the channel were presented and discussed. The results of this investigation indicate that the size of recirculation caused by ...
This article explores how action research, design based research and interaction design can be combined and used in the development of educational robotic tools. Our case study is the development of Number Blocks and it combines physical interaction, learning, and immediate feedback. Number Blocks supports the children's understanding of place value in the sense that it allows them to experiment with creating large numbers. The development was done in collaboration with a class of 7-8 year old children and their mathematics teacher. The article argues that elements from different research methods allowed a structured approach to projects that combines educational research and innovation of new learning technologies. Key elements of this approach is acknowledging the users input, developing a theoretical pre-analysis and using an iterative approach.
The difference between the two nonclassical lights, i.e., the squeezed state and number-phase minimum uncertainty state (NUS) is discussed. The four different generation principles for NUS are described. They are: unitary evolution using self-phase modulation; nonunitary state reduction by the first kind measurement; controlled state reduction by quantum correlation measurement-feedback, and high saturated laser oscillation with suppressed-pump-noise. The constant current-driven semiconductor laser based on the last principle generated the NUS with photon number noise reduced below the standard quantum limit by 40 percent in the entire frequency region from dc to 1.1 GHz. Several applications of NUS including quantum communication, quantum mechanical computers and interferometric gravitational detection are discussed briefly. This presentation is represented by viewgraphs only.
The possibility of employing a number of adsorbents (polyphenylquinoxaline, Tenax GC, Carbopak C, graphitized thermal carbon black, silica gels modified with pyrocarbon or hexamethyldisilazane) for the trapping of organic traces from air has been investigated. Adsorption capacities of these adsorbents with respect to a number of volatiles released from certain plastics used as building material (polyvinylchloride, Relin, Acronal, etc.) have been measured. A number of the volatiles were identified by gas chromatography - mass-spectrometry after trapping on the adsorbents investigated. Chromatographic separation after trapping on the adsorbents was carried out on wall-coated open-tubular capillary columns as well as in capillary columns packed with graphitized thermal carbon black.
The coolant activity analysis to obtain the information about the fuel failure has been studied long before. And several codes have been developed to estimate the number of fuel failures through evaluating volatile and inert fission products release in coolant from the defective fuel. These codes use a fission product diffusion model coupled with a mass balance in the gap and coolant. But each code has a different model to assess fuel failure. In order to develop the model to estimate the number of fuel failures we analysis well-known code's models such as CHIRON, CADE, IODYNE, and CAAP and compare accuracy through Korean PWR activity data
Fundamental phenomena of condensation heat transfer at a steam-water interface have been studied related to the thermo-hydrodynamics of the emergency core cooling system for light water reactors. In this study temperature fluctuations near the interface and in the liquid phase were measured using fine thermocouples for a saturated steam-subcooled water co-current stratified two-phase flow in a nearly horizontal rectangular channel, and heat transfer coefficients were determined experimentally. The values of the condensation heat transfer coefficients in this experiment are from 6 to 40 kW/m{sup 2}K. In the regions of high Reynolds numbers, as the steam Reynolds numbers become larger, the average interfacial heat transfer coefficients tend to increase. The corelations of Nusselt numbers were obtained from the heat transfer data. (author)
Fundamental phenomena of condensation heat transfer at a steam-water interface have been studied related to the thermo-hydrodynamics of the emergency core cooling system for light water reactors. In this study temperature fluctuations near the interface and in the liquid phase were measured using fine thermocouples for a saturated steam-subcooled water co-current stratified two-phase flow in a nearly horizontal rectangular channel, and heat transfer coefficients were determined experimentally. The values of the condensation heat transfer coefficients in this experiment are from 6 to 40 kW/m"2K. In the regions of high Reynolds numbers, as the steam Reynolds numbers become larger, the average interfacial heat transfer coefficients tend to increase. The corelations of Nusselt numbers were obtained from the heat transfer data. (author)
Gastrointestinal patches represent a novel multiparticulate drug delivery system able to increase the intestinal absorption of drugs with poor bioavailability. The number of patches to administer is a critical issue since it is related to the surface and drug concentration at the absorption site. The objective of this article is to evaluate the effect of the number of administered patches on the final absorption of leuprolide, a peptide chosen as model drug, assuming complete adhesion of all the devices to the intestinal membrane. The same dose of leuprolide was encapsulated into 2, 4 and 6 patches; the resulting intestinal absorption profiles were measured with the Ussing chamber ex vivo experimental setup and compared between them. The results showed that varying the number of patches, t...
A numerical analysis is performed to clarify the heat transfer characteristics of combined convection around the tubes which form a single row perpendicularly arranged to a forced flow in the direction of gravity. A boundary-fitted coordinate transformation technique is adopted to solve the governing equations numerically. It is found in the case of liquid sodium that gravity-induced flow gives no substantial effect to heat transfer augmentation in a low Reynolds number region while it can be sufficiently expected in the ordinary fluids in the same Reynolds number region. This means that such heat transfer augmentation as expected in ordinary fluids can not be realized when crossflow-type heat exchangers installed for decay-heat removal operates in a low Reynolds number region.
The objective of this study was to evaluate the association between the number of blood cultures collected and the appropriateness of care for suspected bacteremic community-acquired urinary tract infection (UTI) in the elderly. We retrospectively evaluated the medical records of 129 patients with UTI >65?years old admitted to a large community-based training hospital in Japan from 1 January 2006 to 31 December 2009. We assessed the association between the number of blood cultures collected and the appropriateness of care received, as well as other factors. Two-thirds of the patients were women, and patients >85?years old accounted for 45.0% of the cases. Most of the organisms isolated from the urine and blood were Escherichia coli (65.4?67.0%). More than two blood cultures were collected ...
The field of micro unmanned aerial vehicles ({mu}UAVs) has advanced rapidly in recent years. This paper studies the design and construction of a small solar-powered aircraft near the size range of current {theta}UAVs. A number of aspects of their design were analysed, including structural, aerodynamic and propulsion system considerations. The effect of small-scale, low Reynolds number aerodynamics was investigated, and the performance of a range of candidate aerofoils was compared. The integration of a solar power source into the aircraft system was considered a key design issue. Consequently, a number of aircraft configurations were examined, with the intention of optimising the application of solar power in a miniature aircraft. Investigation of improved system components suggests that a practical solar-powered aircraft in the size range below 500 mm maximum linear dimension should be viable given modest technological ...
A numerical analysis is performed to clarify the heat transfer characteristics of combined convection around the tubes which form a single row perpendicularly arranged to a forced flow in the direction of gravity. A boundary-fitted coordinate transformation technique is adopted to solve the governing equations numerically. It is found in the case of liquid sodium that gravity-induced flow gives no substantial effect to heat transfer augmentation in a low Reynolds number region while it can be sufficiently expected in the ordinary fluids in the same Reynolds number region. This means that such heat transfer augmentation as expected in ordinary fluids can not be realized when crossflow-type heat exchangers installed for decay-heat removal operates in a low Reynolds number region. (author).
The aim of this study was to evaluate the automated urine test strip analyzer Aution Max AX 4280 which uses strips able to measure 12 urinary parameters. For precision study, we considered glucose, protein, blood, leukocytes, nitrite, and pH and the four first were compared with usual methods: chemical measurement or microscopic examination. Reproducibility of the semi quantitative results was determined as the proportion of results falling into the same concentration range. Within-run reproducibility assessed using urine specimens were between 83% and 96%. Between day on quality controlled materials, it was higher (96%), and leukocytes were shared between two classes 250 and 500 cells/microL. For glucose and proteins, linearity was good and comparison with quantitative methods yielded high correlation. The false negative fraction was low and there was no false positive results. For blood, fraction of false positive was 7.5% for 0.3 mg/L of hemoglobin compared with ...
Ontario's electricity industry restructuring program is reviewed, with a view to identify the reasons behind the failure of deregulation which was expected to create competition, to stabilize, or even reduce, prices to consumers, and attract serious private sector investment for the construction of new generating capacity. The report painstakingly reviews the series of events which resulted in a steep rise in electricity rates during the summer of 2002, immediately after deregulation came into effect, which led to freezing retail electricity rates and related charges by the then Conservative provincial government, and the reversal of that decision by the newly-elected Liberal government in the fall of 2003, and plans to bring back retail hydro rates that reflect the cost of production. The authors provide a discussion of policy options and a series of recommendations that are expected to create incentives to reduce and shift demand, encourage the use of ...
A whole sequence of the parameters of the combined heat and power system (KWK) is described which enables a comparison between the electricity and heat demand of a consumer and the energy availability through a combined heat and power system. Proceeding from this, a thermodynamic model of a steam and gas process with combined heat and power is introduced which is based on an exergetic balancing of the subsystems of the process. In this way, the varying thermodynamic quality of the energy flows occuring in the process will be taken into consideration so that the results of the model correspond in any case with the second law of thermodynamics. (orig.) [Deutsch] Es wird ein vollstaendiger Satz von Kenngroessen der Kraft-Waerme-Kopplung (KWK) beschrieben, mit dessen Hilfe der Strom- und Waermebedarf eines Verbrauchers mit der Energiebereitstellung durch eine KWK-Anlage verglichen werden kann. Darauf aufbauend wird ein thermodynamisches Modell des GuD-Prozesses mit Kraft-Waerme-Kopplung ...
The Plant Life Assessment Network (PLAN) is a Brite Euram Type II Thematic Network, initiated by the European Commission to facilitate structured co-operation between all cost shared action projects already funded by the Commission which fall under this common technical theme. The projects involved address a multiplicity of problems associated with plant life assessment and are drawn from Brite-Euram, Standards, Measurement and Testing, Nuclear Fission Safety and Esprit EC programmes. The main aim of the Network is to initiate, maintain and monitor a fruitful co-operation process between completed, ongoing and future EC R and D projects, thereby promoting improved cross fertilization and enhanced industrial exploitation of R and D results. As the project is in its infancy, this presentation covers the background to the initiative in some detail. In particular two key aspects are highlighted, namely, the requirement of the EC to launch such a network in the area of ...
The influence of high C martensite on the strength and impact behavior of C-Mn-Nb-Al steels has been determined for two distributions: films surrounding the ferrite grains and distinct colonies. In the former case, the impact behavior markedly deteriorated, this deterioration increasing with martensite level. The changes in impact behavior could be explained by regarding the films of martensite as being similar to the brittle grain boundary carbides that are present in ferrite-pearlite steels. These films readily crack, yet are always thick enough to produce a sufficient wide crack to render crack propagation easy. The critical event in fracture then becomes the ability to propagate the cracks through the grain boundaries. The greater the grain boundary coverage by these films, the easier this becomes and the worse is the impact behavior. When the martensite is present as colonies, again the impact performance is seriously impaired, but to a lesser extent than when the martensite is ...
The aim of this work is to develop an industrial process for the synthesis of an extrusible electrolyte polymer for lithium batteries. From literature data and precise specifications the high molar mass EO/OP copolymers synthesis by coordinative catalysis has been studied in order to reach a high productivity and to minimize the treatment steps. Two catalytic systems have been studied: the aluminium alkoxide-based Vandenberg-type catalysis and the calcium alcoholate amides catalysis. The first catalysis performed in solution gives excellent results. Its adaptation to silicon supported catalysis leads to a directly usable polymer in suspension but the productivity falls down and remains to be optimized. The calcium amide catalysis in heptane suspension generates acceptable productivities but also a too high proportion of low molar masses. Various approaches have been studied to minimize this proportion due to the presence of secondary sites that generate a cationic ...
Version III of the Salix Maskiner ``Bender`` coppice harvester was used to successfully harvest 11.2 hectares of short rotation poplar and willow coppice in February 1997. On a wide range of typical UK crop and site conditions, the Swedish harvester was shown to have productivity rates ranging from 4.28 to 7.97 odt/smh. Based on a total system cost of Pound 81.26 per scheduled machine hour, the Bender III is able to produce wood chip for between Pound 10.20 and pound 18.97 per dry tonne. The variation in machine productivity is dependent on crop productivity and working method, emphasising the importance of site design in optimising system efficiency. In willow crops the wood chip produced by the Bender III contained a significant amount of material greater than 75mm in length. The bulk of the chips however, fell into the 5-45mm category with only a very limited amount of fine materials less than 5mm in length. The chips from poplar crops were more uniform with the majority of material ...
This report is a review of waste form options for the immobilization of high-level-liquid wastes from the nuclear fuel cycle. This review covers the status of international research and development on waste forms as of May 1979. Although the emphasis in this report is on waste form properties, process parameters are discussed where they may affect final waste form properties. A summary table is provided listing properties of various nuclear waste form options. It is concluded that proposed waste forms have properties falling within a relatively narrow range. In regard to crystalline versus glass waste forms, the conclusion is that either glass of crystalline materials can be shown to have some advantage when a single property is considered; however, at this date no single waste form offers optimum properties over the entire range of characteristics investigated. A long-term effort has been applied to the development of glass and calcine waste forms. Several ...
We used the tissue distribution of ({sup 14}C)butanol to quantitate regional blood flow in the spinal cord (RSCBF) of pentobarbital-anesthetized, normothermic rats in which segmental local cooling pentobarbital-anesthetized, normothermic rats in which segmental local cooling of the spinal cord (to 25-28{degrees}C) at vertebral levels C4-C6 (n = 6) or T13-L1 (n = 6) was induced. Thirty minutes later, blood flow measurements were made at seven levels of the spinal cord and in the sciatic nerve trunks and biceps femoris muscles. Sham-cooled rats served as controls (n = 12). In control rats, RSCBF varied between 41.5 +/- 2.4 and 65.1 +/- 3.2 ml.min-1.100 g-1. Local cooling of the C4-C6 cord segment reduced RSCBF by 32%, from 65.1 +/- 3.2 to 44.4 +/- 3.5 ml.min-1.100 g-1 (P less than 0.01). Tissue vascular resistance (R) in the cooled C4-C6 segment was elevated versus control. There were no other changes in RSCBF at the other cord levels or in the cauda equina. Similarly, local cooling of ...
PWR primary circuit radiolysis model describes oxygen/hydrogen behavior in the Westinghouse Sizewell B 4-loop PWR (SNUPPS design). The effect of oxygen ingress have also been evaluated using the same model. There is clear agreement from experimental and modelling data that the dissolved hydrogen concentration required to suppress radiolysis decreases as the temperature increases. There is good evidence from the study at the Belleville PWR that {approx}5 cc(STP)kg{sup -1} H{sub 2} is sufficient to suppress radiolysis during power operation. Modelling indicates that the minimum hydrogen concentration is about 0.5 cc (STP)kg{sup -1} at PWR operating temperatures and that the presence of boric acid has little effect on this value, although it does increase the steady-state concentration of H{sub 2}O{sub 2}. Downstream of the core the concentrations of both oxygen and hydrogen peroxide fall by about two orders of magnitude at full power due to reaction with radicals ...
Previously, an analytical dose calculation algorithm for MLC-based radiotherapy was developed and commissioned, which includes a detailed model of various MLC effects as a unique feature [1]. The algorithm was originally developed as an independent verification of the treatment planning system's dose calculation and it explicitly modeled spatial and depth dependent MLC effects such as interleaf transmission, the tongue-and-groove effect, rounded leaf ends, MLC scatter, beam hardening, and gradual MLC transmission fall-off with increasing off-axis distance. Originally the algorithm was implemented in Mathematica trademark (Wolfram). To speed up the calculation time and to be able to calculate high resolution 2D dose distributions within a reasonable time frame (<2 s) the algorithm needs to be optimized and to be embedded in a user friendly environment. To achieve this goal, the dose calculation model is implemented in Visual Basic 6.0, which decreases the ...
The Mittelplate oilfield is located in the Waddensea tidelands 8 km off the north sea coast and represents Germany's largest oilfield. Since Mittelplate oil production has started in 1987, RWE Dea AG being the operator in a 50/50 joint venture with Wintershall AG, has continually implemented and improved the sophisticated technology required to exploit natural resources by using safe and environmentally compatible means in the sensitive tideland environment of Mittelplate. Besides the sucessful offshore operations from the man-made Mittelplate Drilling and Production Island, further onshore development has started in 2000 by producing from high-tech ERD wells drilled from onshore locations. The offshore oil production had been transported so far by specially designed tug and tow barges and had been restricted by weather and tide. To overcome this bottleneck and to enable an accelerated offshore drilling and production program a pipeline link between Mittelplate Island and ...
Large-eddy-simulations are performed for the heat transfer and the wake flow of a thin rotating disk subjected to an outer parallel passing stream of air. Above a critical value for the angular velocity of the disk, heat transfer augmentation sets on. This is strongly related to a flow instability that leads to a periodic vortex generation at the counter-moving disk side. The resulting phenomena are captured by the classical Landau model. For higher angular velocities the wake becomes fully turbulent, and here the transition to turbulence seems to be very abrupt. In this regime, a periodic vortex generation is observable at the co-moving disk side, too. (orig.) [German] Grobstruktur-Simulationen werden fuer die Waermeuebertragung und die Nachlaufstroemung fuer eine duenne rotierende Scheibe in einem aeusseren parallelen Luftstrom durchgefuehrt. Oberhalb eines kritischen Wertes fuer die Rotationsgeschwindigkeit setzt eine Verstaerkung der Waermeuebertragung ein. Dies ist eng mit einer ...
Lherzolite-bearing basanitic magmas of Quaternary age have erupted to form maars, lava/cinder cones and lava flows in two volcanic fields (Ventura and Santo Domingo) in the central Mexican state of San Luis Potosi. The systematics of the radiogenic isotopes of Sr, Nd, and Pb and the relationship between these parameters and elemental compositions are used to investigate the petrogenesis of the volcanic rocks and the nature of their mantle sources. Sr and Nd isotopic data are presented for 19 basanitic rocks, 5 kaersutites, and 6 lherzolitic xenoliths; Pb data presented for the same 19 volcanic rocks and 4 of the 5 kaersutites. The isotopic compositions for all of these samples fall within the mantle range defined by MORBs and OIBs. The basanites generally plot within the OIB field on isotopic diagrams; most of the kaersutites are displaced to slightly more-depleted (i.e. MORB-like) values than the volcanic samples and the xenoliths, with one exception, are ...
Molybdenum is an essential element for living organisms. Moreover its radionuclides may represent an incorporation risk for members of the public and/or radiation workers after a nuclear accident or a release of radioactive materials. However, only few reliable data on Mo biokinetics in humans were available. The results of recent tracer kinetic investigations with stable isotopes have shown several differences from the ICRP data with regard to the processes of intestinal absorption and of excretion. As a consequence, the dose coefficients calculated with a revised biokinetic model deviate from the ICRP estimates. By ingestion of {sup 99}Mo radionuclides with solid food, for example, the dose to the colon may be higher of a factor up to 1 order of magnitude, due to the fraction of non-absorbed material which traverses the gastro-intestinal tract. (orig.) [Deutsch] Molybdaen ist einerseits ein fuer Lebewesen essentielles Spurenelement, andererseits koennen radioaktive Mo-Isotope im ...
The biobaler was originally developed for short-rotation willow plantations, but can currently harvest a wide range of woody crops with a basal diameter up to 150 mm. The biobaler is an alternate approach to harvest woody crops as round bales, generally 1.2 m wide by 1.5 m diameter. In addition to harvesting trees, it can improve management of wild brush, forest understory vegetation and encroaching small trees on abandoned land. It allows easy handling, storage and transportation to sites where the biomass can be used for energy use or other applications. This paper reported on a study that was conducted in the fall of 2009 in which a third generation biobaler was used on 8 different sites across Minnesota, notably Waseca, Madelia, Faribault, Afton, Ogilvie, Hinckley, Aurora and Hibbing. A total of 160 bales were harvested from these sites. The average bale mass was 466 kg and average bale density was 296 kg/m{sup 3}. The moisture content averaged 44.9 per cent ...
Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is crucial in meeting the needs of these new markets. To address the gas storage needs of the natural gas industry, an ...
Martin Marietta Energy Systems, Inc. (Energy Systems) manages a closed hazardous waste disposal unit, Chestnut Ridge Security Pits (CRSP), in the form of two trenches and several auger-holes, located on top of the eastern portion of Chestnut Ridge at the Department of Energy (DOE) Oak Ridge Y-12 Plant in Tennessee. The groundwater monitoring system for the unit presently consists of a network of upgradient and downgradient monitor wells. To investigate the discharge of groundwater to springs and streams, Energy Systems, through Geraghty and Miller, Inc., conducted an initial dye-tracer study during the driest part of 1990. The dye was detected at some of the monitoring sites, but verification was necessary due to the proximity of some sites to extraneous dye sources. Based on the results of the initial study, Energy Systems recommended to the Tennessee Department of Environment and Conservation (TDEC) in the 1990 Groundwater Quality Assessment Report (GWQAR) (HSW 1991) for the CRSP ...
The effects of extended source-to-surface distance (SSD) on the electron beam dose profiles were evaluated for various electron beam energies - 6, 9, 12, 15 and 20 MeV - and the accuracy of various output correction methods was analysed on a Mitsubishi linear accelerator using a radiation field analyser (RFA). The dose fall-off region of the central axis depth-dose curves was nearly independent for SSDs up to 120 cm where as in the build-up region, a marginal reduction of surface dose was observed, particularly for lower energies and for smaller field sizes. Effective SSDs and virtual source distances were evaluated for field sizes ranging from 5x5 to 15x15 cm"2 for various energies. Curve fitting was done with the measured outputs with various equations and coefficients were evaluated. The accuracy of the derived output correction factors by effective SSD, virtual source distance and curve-fit methods was assessed by evaluating correlation coefficients between the ...
An attempt was made for early quantitative assessment of the severety of an injury, using the nuclear acids (NA) content as a biochemical indicator. Sexually mature male rats with body mass 160-180 g were irradiated with doses 0.5, 1, 2, 4 and 8 Gy of "1"3"7Cs source. Uneven irradiation was achieved by shielding the abdominal-lumbar area with lead rings, measuring 2,5/50 mm. A 28-30% fall of the dose beneath the shielded zone was thus provided. Dose-dependent quantitative changes in Na content were determined on hours 24 and 72 within the range from 0.5 to 8 Gy and followed up until day 30 after irradiation with nonlethal (2 Gy) and lethal (8 Gy) doses. The total NA content in the leucocytes was determined by the method of Kritski and Aleksandrov. The uneven irradiation of rats within the 0,5-8 Gy range induced early dose-dependent changes in NA content. The nature of their post-irradiation dynamics also depended on the radiation dose and adequately reflected the ...
The gotten concentrations of radon-222 in the installations of the IEN had been determined using the active and passive methods. The active method consisted on the use of the alpha spectrometry with a portable equipment Tracerlab Instruments WLM- Plus. In the determination for the passive method, one used detectors of nuclear strokes of type LEXAN. The raised values had been gotten in the wastes deposit and its annexes, room of the press and laboratory of wastes handling. It was observed, in this sector, an instantaneous measure of alpha spectrometry, concentrations around 1000 Bq.m-3, which had over all to the function of storage, the sector, a great volume of natural radioactive materials, especially of radium-226. This determination was carried through in an extreme situation of ventilation zero, where the gates had been kept closed during the execution of the same one. It was observed, however, a considerable fall, with values ten times inferior, after to ...
Detailed chemical kinetic reaction mechanisms are developed for combustion of all nine isomers of heptane (C{sub 7}H{sub 16}), and these mechanisms are tested by simulating autoignition of each isomer under rapid compression machine conditions. The reaction mechanisms focus on the manner in which the molecular structure of each isomer determines the rates and product distributions of possible classes of reactions. The reaction pathways emphasize the importance of alkylperoxy radical isomerizations and addition reactions of molecular oxygen to alkyl and hydroperoxyalkyl radicals. A new reaction group has been added to past models, in which hydroperoxyalkyl radicals that originated with abstraction of an H atom from a tertiary site in the parent heptane molecule are assigned new reaction sequences involving additional internal H atom abstractions not previously allowed. This process accelerates autoignition in fuels with tertiary C-H bonds in the parent fuel. In addition, the rates of ...
The carbon isotope profiles of shallow-marine carbonates from the Barremian-Aptian Kharaib and Shuaiba formations of the Arabian Gulf region range between 0.5 and 7{per_thousand} {delta}{sup 13}C PDB (Peedee belemnite). Systematic variations can be correlated with isotope profiles reported from Tethyan pelagic limestone sequences. The detailed correspondence between the isotopic signature of the relatively well-dated pelagic limestones and the poorly dated shallow-water limestones from the Arabian Gulf region suggests that global marine carbon isotope changes apparently affected deep-sea and shallow-water carbonate sediments similarly and at a similar time resolution. Although oxygen isotopes have been reset during diagenesis, carbon isotopes appear to have maintained their primary marine signature through time. No evidence has been found to connect carbon isotope trends to subaerial exposure or later meteoric diagenesis. In combination with other data, the investigated carbon isotope ...
Aim: To investigate interpretative accuracy and reporting time for radiologists performing computed tomography (CT) colonography in day-to-day non-academic clinical practice. Materials and methods: Thirteen radiologists from seven centres, who were reporting CT colonography in non-academic daily clinical practice, interpreted a dataset of 15 colonoscopically validated cases in a controlled environment. Ten cases had either a cancer or polyp >10 mm; one case had a medium polyp and four were normal. Correct case categorization and interpretation times were compared using analysis of variance to aggregated results obtained from both experienced observers and observers recently trained using 50 cases, working in an academic environment. The effect of experience was determined using Spearman's rank correlation. Results: Individual accuracy was highly variable, range 53% (95% CI 27-79%) to 93% (95% CI 68-100%). Mean accuracy overall was significantly inferior to experienced ...
During outbreaks, Microdiprion pallipes (Fall.) is the most destructive of the pine sawflies in Sweden. Its distribution includes most provinces, but damaging outbreaks have until recently occurred only in two inland areas in northern Sweden. These areas are characterised by high elevation, a harsh climate, and slow tree growth. The four recorded outbreak periods showed a 10 year periodicity. Outside these areas, a lesser outbreak occurred in 1988 to 1990, on the east coast (province of Uppland). Outbreak patterns, life history variation, and mortality factors were studied. Factors that may explain the distribution of outbreaks and the population patterns were identified.Experimental and observational evidence on the potential of various factors to influence fecundity, dispersal, and survival was evaluated. In the outbreak areas, there were few major population factors. Parasitism by Rhorus substitutor (Thunb.) was the largest cause of larval mortality and the only ...
An overview of the understanding of correlation between valence electron and the optical properties of binary (A{sup N}B{sup 8-N}) and ternary (A{sup N}B{sup 2+N}C{sub 2}{sup 7-N}) tetrahedral semiconductors is presented here. We have presented two expressions relating the dielectric constant and electronic polarizability for the transition metal chalcogenides and pnictides (A{sup II}B{sup VI} and A{sup III}B{sup V}) and chalcopyrites (A{sup I}B{sup III}C{sub 2}{sup VI} and A{sup II}B{sup IV}C{sub 2}{sup V}) with the product of valence electrons and nearest neighbour distance d (A). The dielectric constant and electronic polarizability of these solids exhibit a linear relationship when plotted on a log-log scale against the nearest neighbour distance d (A), but fall on different straight lines according to the valence electron product of the compounds. We have applied the proposed relation on these solids and found a better agreement with the experimental data as ...
Natural laminar-flow (NLF) airfoils are those which can achieve significant extents of laminar flow (greater than or equal to 30% chord) solely through favorable pressure gradients. Studies have shown that vertical-axis wind turbines (VAWTs) using NLF sections as blade elements have the potential of producing energy at a significantly lower cost (approx. =20%) than turbines of current design. Sandia National Laboratories (SNL) is now in the process of procuring a blade set for its 17-m-diameter research turbine which will use NLF sections as blade elements. This paper describes the design of this blade set. The blade set design began with the definition of a family of three approximately 50% chord NLF sections (15, 18, and 21% t/c). These definitions involved numerically establishing airfoil contours giving section characteristics anticipated to be favorable in the VAWT context and then screening these using a VAWT performance model. Field tests of the 15 and 18% t/c sections as ...
The process of implementing a damage detection strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring (SHM). Here damage is defined as changes to the material and/or geometric properties of these systems, including changes to the boundary conditions and system connectivity, which adversely affect the system's current or future performance. Our approach is to address the SHM problem in the context of a statistical pattern recognition paradigm (Farrar, Nix and Doebling, 2001). In this paradigm, the process can be broken down into four parts: (1) Operational Evaluation, (2) Data Acquisition, (3) Feature Extraction, and (4) Statistical Model Development for Feature Discrimination. When one attempts to apply this paradigm to data from 'real-world' structures, it quickly becomes apparent that data cleansing, normalization, fusion and compression, which can be implemented with either hardware or ...
A cryocondensation pump was designed for the baffle chamber of General Atomics DIII-D tokamak and will be installed in the fall of 1992. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long and located in the lower outer corner of the vacuum chamber of the machine. It consists of a 1 m{sup 2} liquid helium-cooled surface surrounded by a liquid nitrogen-cooled shield to limit the heat load on the helium-cooled surface. The liquid nitrogen-cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. A thermal enhancement coating was applied to the nitrogen shell to lower the maximum temperature of the shell. The coating is non-continuous to keep the toroidal electrical resistance high. The whole pump is supported off the water-cooled vacuum vessel wall. Supports for the pump were designed to ...
Steam generators (SG) are among the most critical components of pressurized water Nuclear Power Plants (NPP). SG tubes must provide a reliable pressure boundary between the primary and secondary cooling water. It is because that any leakage from tube defects could result in the release of radioactivity to the environment. Thus degradations of steam generators tubes should be monitored and inspected periodically under nuclear regulatory. In-service inspections of SG tubes are carried out using eddy current test (ECT) and the defected tubes are usually plugged. Because the radioactivity in the internal of SG chambers limits free access of human worker, remote manipulators are required. In South Korea, Manipulators such as the Zetec SM series and the Westinghouse ROSA series have been used. Such manipulators are rigidly mounted to manways or tube sheets of SG. Confusions for the inspected tubes may occur from deflection of the manipulators. To reduce the deflections of the manipulators ...