Energy Technology Data Exchange (ETDEWEB)

For years rock bit performance has been progressively improved by many innovative changes to the design of both the bit cutting structure and the bearing. The changes have offered increased footage per bit and reduced cost per foot of hole through longer bit life and/or faster penetration rate. Efforts to assist the industry in drilling deeper thru hard abrasive rocks such as cherts of West Texas, conglomerated of the Rockies and bromides of Oklahoma led to a major breakthrough in rock bit design - the development of the tungsten carbide cutting structure. When properly applied the bit far exceeded that of the non-sealed ball and roller bearing being used at the time. The bearing failure mode was one of severe race spalling and abrasive wear influenced by the drilling fluid entering the bearing.

CERN Document Server

Typical receiver processing, targeting always the best achievable bit error rate performance, can result in a waste of resources, especially, when the transmission conditions are such that the best performance is orders of magnitude better than the required. In this work, a processing framework is proposed which allows adjusting the processing requirements to the transmission conditions and the required bit error rate. It applies a-posteriori probability receivers operating over multiple-input multiple-output channels. It is demonstrated that significant complexity savings can be achieved both at the soft, sphere-decoder based detector and the channel decoder with only minor modifications.

CERN Document Server

Inter-symbol interference (ISI) channels with data dependent Gauss Markov noise have been used to model read channels in magnetic recording and other data storage systems. The Viterbi algorithm can be adapted for performing maximum likelihood sequence detection in such channels. However, the problem of finding an analytical upper bound on the bit error rate of the Viterbi detector in this case has not been fully investigated. Current techniques rely on an exhaustive enumeration of short error events and determine the BER using a union bound. In this work, we consider a subset of the class of ISI channels with data dependent Gauss-Markov noise. We derive an upper bound on the pairwise error probability (PEP) between the transmitted bit sequence and the decoded bit sequence that can be expressed as a product of functions depending on current and previous states in the (incorrect) decoded sequence and the ...

CERN Document Server

Targeting always the best achievable bit error rate (BER) performance in iterative receivers operating over multiple-input multiple-output (MIMO) channels may result in significant waste of resources, especially when the achievable BER is orders of magnitude better than the target performance (e.g., under good channel conditions and at high signal-to-noise ratio (SNR)). In contrast to the typical iterative schemes, a practical iterative decoding framework that approximates the soft-information exchange is proposed which allows reduced complexity sphere and channel decoding, adjustable to the transmission conditions and the required bit error rate. With the proposed approximate soft information exchange the performance of the exact soft information can still be reached with significant complexity gains.

Science.gov (United States)

Internet bandwidth is in high demand, and one way that web sites lower the amount of bandwidth they use is by compressing their site's images. This lowers the amount of bandwidth used, and makes the site load much faster. There are of course many other useful applications for compressed images. Bit Plane Complexity Segmentation (BPCS) digital picture steganography is a technique to hide data inside an image file. BPCS achieves high embedding rates with low distortion based on the theory that noise-like regions in a bit-plane can be replaced with noise-like secret data without discernible loss in image quality. This is possible because the human eye, while very good at distinguishing anomalies in areas of homogenous texture, is bad at distinguishing anomalies in visually complex areas. However, BPCS is not a robust embedding scheme, and any lossy compression usually destroys the data. Wavelet image compression using the ...

CERN Document Server

We describe a scheme for quantum error correction that employs feedback and weak measurement rather than the standard tools of projective measurement and fast controlled unitary gates. The advantage of this scheme over previous protocols (for example Ahn et. al, PRA, 65, 042301 (2001)), is that it requires little side processing while remaining robust to measurement inefficiency, and is therefore considerably more practical. We evaluate the performance of our scheme by simulating the correction of bit-flips. We also consider implementation in a solid-state quantum computation architecture and estimate the maximal error rate which could be corrected with current technology.

CERN Document Server

The work identifies the first lattice decoding solution that achieves, in the general outage-limited MIMO setting and in the high-rate and high-SNR limit, both a vanishing gap to the error-performance of the (DMT optimal) exact solution of preprocessed lattice decoding, as well as a computational complexity that is subexponential in the number of codeword bits. The proposed solution employs lattice reduction (LR)-aided regularized (lattice) sphere decoding and proper timeout policies. These performance and complexity guarantees hold for most MIMO scenarios, all reasonable fading statistics, all channel dimensions and all full-rate lattice codes. In sharp contrast to the above manageable complexity, the complexity of other standard preprocessed lattice decoding solutions is shown here to be extremely high. Specifically the work is first to quantify the complexity of these lattice (sphere) decoding solutions and to prove the ...

Science.gov (United States)

A newly developed 220 Mbps free-space 4-ary pulse position modulation (PPM) direct detection optical communication system is described. High speed GaAs integrated circuits were used to construct the PPM encoder and receiver electronic circuits. Both PPM slot and word timing recovery were provided in the PPM receiver. The optical transmitter consisted of an AlGaAs laser diode (Mitsubishi ML5702A, lambda=821nm) and a high speed driver unit. The photodetector consisted of a silicon avalanche photodiode (APD) (RCA30902S) preceded by an optical interference filter (delta lambda=10nm). Preliminary tests showed that the self-synchronized PPM receiver could achieve a receiver bit error rate of less than 10(exp -6) at 25 nW average received optical signal power or 360 photons per transmitted information bit. The relatively poor receiver sensitivity was believed to be caused by the insufficient electronic bandwidth of the APD ...

Energy Technology Data Exchange (ETDEWEB)

The authors review two types of simulators for the analysis of cosmic ray neutron-induced soft errors (SE's). One of them is the neutron-induced soft error simulator (NISES). A recently proposed nuclear reaction theory forms the foundation for the nuclear reaction database used in NISES. The other simulator, the simplified simulator MBGR, is based on a modified version of the burst generation rate (BGR) model. Both simulators accurately simulate neutron-induced SE rates (SER's). MBGR actually provides an easier and quicker estimation of neutron-induced SER's than NISES. On the other hand, NISES covers more applications; it simulates neutron-induced charge collection, multiple-bit SE, and [alpha]-induced SE analysis.

Energy Technology Data Exchange (ETDEWEB)

Free Topology Network technology provides cost reduction benefits as well as flexibility in safeguards applications. Power line communications technologies have proven viability for transmission and reception of safeguards data, including surveillance photographs, the source of the largest data files. In the future, enhancements will be made to the technology that should boost both performance and flexibility. Work is already underway to achieve higher data rates over power line communications eventually, it should be possible to reach data rates of one million bits per second or higher. Also, the use of technologies such as Novell Embedded Systems Technology (NEST) and Echelon LON technology will allow a greater number of safeguards technologies to become resident on the Free Topology Safeguards Network.

International Nuclear Information System (INIS)

Based on proposed models for the tidal spin-up and magnetic braking of stars with a convective outer envelope, it is suggested that the rotation of secondaries in cataclysmic variables is not necessarily synchronized with the orbital revolution. This may provide an explanation for the observed large range in the mass transfer rate (at the same orbital period) of cataclysmic variables above the period gap. (author).

Energy Technology Data Exchange (ETDEWEB)

Metal oxide semiconductor (MOS) integrated circuits, with the benefits of low power consumption, represent the state of the art technology for implantable medical devices. Three significant sources of radiation are classified as having the ability to damage or alter the behavior of implantable electronics; Secondary neutron cosmic radiation, alpha particle radiation from the device packaging and therapeutic doses(up to 70 G{gamma}) of high energy radiation used in radiation oncology. The effects of alpha particle radiation from the packaging may be eliminated by the use of polyimide or silicone rubber die coatings. The relatively low incidence of therapeutic radiation incident on an implantable device and the use of die coating leaves cosmic radiation induced secondary neutron single event upset (SEU) as the main pervasive ionising radiation threat to the reliability of implantable devices. A theoretical model which predicts the susceptibility of a RAM cell to secondary neutron cosmic ...

Energy Technology Data Exchange (ETDEWEB)

This work considers the problem of controlling multiple nonholonomic vehicles so that they converge to a scent source without colliding with each other. Since the control is to be implemented on simple 8-bit microcontrollers, fuzzy control rules are used to simplify a linear quadratic regulator control design. The inputs to the fuzzy controllers for each vehicle are the (noisy) direction to the source, the distance to the closest neighbor vehicle, and the direction to the closest vehicle. These directions are discretized into four values: Forward, Behind, Left, and Right, and the distance into three values: Near, Far, Gone. The values of the control at these discrete values are obtained based on the collision-avoidance repulsive forces and the change of variables that reduces the motion control problem of each nonholonomic vehicle to a nonsingular one with two degrees of freedom, instead of three. A fuzzy inference system is used to obtain ...

Energy Technology Data Exchange (ETDEWEB)

FastBit is a software package designed to meet the searching and filtering needs of data intensive sciences. In these applications, scientists are trying to find nuggets of information from petabytes of raw data. FastBit has been demonstrated to be an order of magnitude faster than comparable technologies. In this brief report, we highlight how we work with a visualization team, a network security team and a DNA sequencing center to find the nuggets in their data.

International Nuclear Information System (INIS)

Quantum key distribution (QKD) can, in principle, provide unconditional security based on the fundamental laws of physics. Unfortunately, a practical QKD system may contain overlooked imperfections and may thus violate some of the assumptions in the security proofs of QKD. It is important to explore these assumptions. One key assumption is that the sender (Alice) can prepare the required quantum states without errors. However, such an assumption may be violated in a practical QKD system. In this paper, we perform a proof-of-principle experiment to demonstrate a technically feasible 'intercept- and-resend' attack that exploits such a security loophole in a commercial 'plug and play' QKD system. The resulting quantum bit error rate is 19.7%, which is substantially lower than the well-known 25% error rate for an intercept-and-resend attack in BB84. The attack we utilize is the phase-remapping attack (Fung et al 2007 Phys. Rev. ...

Energy Technology Data Exchange (ETDEWEB)

The environment - external or internal degrees of freedom coupled to the object of interest - can, in effect, monitor some of its observables. As a result, the eigenstates of these observables decohere and behave like classical states. Continuous destruction of superpositions leads to the effective environment-induced superselection (einselection), which is beginning to be recognized as a key step in the transition from quantum to classical. We investigate it here in the context of quantum chaos. I show that the evolution of a chaotic macroscopic system is not just difficult to predict (requiring accuracy exponentially increasing with time) but quickly ceases to be deterministic in principle as a result of the Heisenberg uncertainty (which limits the available resolution). This happens after a time t{sub {Dirac_h}} which is only logarithmic in the Planck constant. For example, various components of the solar system are chaotic, with the Lyapunov timescales ranging from a ...

UK PubMed Central (United Kingdom)

BackgroundAn earlier study showed that a week of yoga practice was useful in stress management after a natural calamity. Due to heavy rain and a rift on the banks of the Kosi river,...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

This paper employs a new approach in order to investigate the underlying relationship between stock markets and exchange rates. Current approaches suggest that the relative equity market performance of two countries is linked to their exchange rate. In contrast, this study proposes an alternative approach where one global variable - global equity market returns - is believed to have an effect on exchange rates, with the relative interest rate level of a currency determining the sign of the relationship. Our empirical findings suggest that exchange rates and global stock market returns are strongly linked. The value of currencies with higher interest rates is positively related with global equity returns, whereas the value of currencies with lower interest rates is negatively related with g...

Science.gov (United States)

... The measured elastic modulus was fairly close to the predicted value, but the ultimate compressive strength (UCS) was quite a bit below the MSC ...

Energy Technology Data Exchange (ETDEWEB)

The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high ...

Energy Technology Data Exchange (ETDEWEB)

The effects of the heating rate from 0.6 up to 50{sup o}C.s{sup -1} on the thermoluminescence of {alpha}-Al{sub 2}O{sub 3}:C are very intensive. The material rapidly loses its high sensitivity as the heating rate increases. The peak shape characteristics, peak maximum and full width at half maximum agree only qualitatively with those theoretically predicted. The trapping parameters calculated by the curve fitting method, the peak shape method, the variable heating rate method and the initial rise method, were found to decrease as the heating rate increases. The validity of the results are discussed in the framework of the kinetic models. (author).

Energy Technology Data Exchange (ETDEWEB)

As part of developing efforts for physical exploration technologies for oil reservoirs, this paper describes development of an active seismic while drilling (SWD). The SWD is a seismic exploration method to acquire records equivalent to VSP using seismic waves generated from a bit executing excavation, and is capable of detection and control on a real time basis during the excavation. However, the drawback is that it is subjected to a limitation in the bit. To eliminate this limitation, an artificial seismic source method was devised. In other words, this is an SWD utilizing an artificial seismic source. The contrivance is such that a shot sub containing a magnetic distortion oscillator is attached directly above a bit to generate vibration artificially, and try to utilize larger seismic energy by combining this vibration with that generated from the excavating bit. Frequency band in the seismic source ...

Energy Technology Data Exchange (ETDEWEB)

Expressions for the spatial moments and macrodispersion tensor for sorbing solutes in heterogeneous formations were presented using a probabilistic model of a fluid residence time coupled with the particle position analysis. The fluid residence time was defined as a fraction of the actual time during which the particle stayed in the mobile fluid phase of the aquifer. The fluid residence time is a random variable whose variability comes as a result of the non-equilibrium sorption properties. The sorbing solute was assumed to be governed with first-order linear kinetics. The closed-form expressions were based on the stationarity in the kinetic process and on the first-order approximation in the hydraulic conductivity field and in the fluid residence time. The non-equilibrium effects were presented as a function of the spatial variability in hydraulic conductivity and temporal variability in the fluid ...

International Nuclear Information System (INIS)

To evaluate the diagnostic performance of commercially available CRT monitors used in a teleradiology system by determining the rate of detection of simulated lung nodules. Three types of CRT monitors were tested in the observation study. They had matrix sizes of 1024 x 768 (16 inches, color), 1024 x 768 (20 inches, color) and 1600 x 1125 (24 inches, black and white). Twenty chest radiographs were obtained by Fuji computed radiography (FCR) of an anthropomorphic chest phantom with ten simulated nodules on its surface. These FCR films were digitized by a film digitizer with 125 DPI (1024 x 1024 matrix sizes) and 12 bit gray scales, and the image data were transferred from Shinshu University Hospital to other hospitals where interpretation was carried out by the radiologists. Ten radiologists of three hospitals were asked to interpret independently both the original FCR films and the images shown on the CRT monitors and to indicate the presence ...

British Library Electronic Table of Contents (United Kingdom)

Recent advances in nanoscience have raised interest in the minimum bit size required for classical information storage. This bit size is determined by the necessity for bistability with suppressed quantum tunnelling and energy barriers that exceed ambient temperatures. In the case of magnetic information storage, much attention has centred on molecular magnets with bits consisting of about 100 atoms, magnetic uniaxial anisotropy energy barriers of about 50?K and very slow relaxation at low temperatures. Here, we draw attention to the remarkable magnetic properties of some transition-metal dimers, which have energy barriers approaching 500?K with only two atoms. The spin dynamics of these ultrasmall nanomagnets is strongly affected by a Berry phase, which arises from quasi-degen...

Science.gov (United States)

A multivariate bioprocess control approach, capable of tracking a pre-set process trajectory correlated to the biomass or product concentration in the bioprocess is described. The trajectory was either a latent variable derived from multivariate statistical process monitoring (MSPC) based on partial least squares (PLS) modeling, or the absolute value of the process variable. In the control algorithm the substrate feed pump rate was calculated from on-line analyzer data. The only parameters needed were the substrate feed concentration and the substrate yield of the growth-limiting substrate. On-line near-infrared spectroscopy data were used to demonstrate the performance of the control algorithm on an Escherichia coli fed-batch cultivation for tryptophan production. The controller showed good ability to track a defined biomass trajectory during varying process dynamics. The robustness of the control was high, despite ...

Energy Technology Data Exchange (ETDEWEB)

The two-phase annular regime is characterized by a high velocity gas stream flowing through the core of the tube surrounded by a thin, highly agitated liquid film flowing concurrently along the tube wall. Part of the liquid may be entrained as droplets in the gas phase. The specific goals of this study were to measure fully developed rates of interchange and entrained fraction over a wide range of flow variables in the upward configuration of the annular regime, to obtain a more fundamental understanding of liquid interchange phenomena via studies of liquid film characteristics and to develop an improved design correlation for the entrained fraction. Towards this end, air-water experiments were conducted in two vertical pipe lines, 2.54 and 4.20 cm in diameter. Air velocities ranging from 20 to 120 m/s and total liquid flow rates ranging from 10 to 100 g/s were investigated. Two models for the rate of ...

Energy Technology Data Exchange (ETDEWEB)

We present the runtime comparison of the two versions of Super LU{_}DIST, using up to 128 processors of the IBM SP at NERSC. One version provides the global input interface, and another provides the distributed input interface. The comparison includes the total runtime of the solver with both 32-bit and 64-bit addressing modes, the time breakdown for different phases of the solver. We also present an in-depth comparison off our sparse matrix-vector multiplication methods in the context of iterative refinement. Finally, we describe our Fortran 90 interface that enhances the usability of the software.

Science.gov (United States)

We analyse the capacity of a simultaneous quantum secure direct communication scheme between the central party and other M parties via M+1-particle GHZ states and swapping quantum entanglement. It is shown that the encoding scheme should be secret if other M parties wants to transmit M+1 bit classical messages to the centre party secretly. However, when the encoding scheme is announced publicly, we prove that the capacity of the scheme in transmitting the secret messages is 2 bits, no matter how large M is.

Energy Technology Data Exchange (ETDEWEB)

A real-time neutron radiography imaging system has been installed at the Texas A and M University Nuclear Science Center. The system employs a scintillating screen viewed by a low-light TV camera with a front surface mirror placed at 45deg to the neutron beam. The key components of the system are the neutron camera and the image capture and processing unit. The neutron camera uses an NE 426 scintillating screen (ZnS), front surface mirror, remote focus and zoom lens, intensified relay optics (IRO) and monochrome CCD television camera. The image capture and processing unit consists of an IBM PC AT-compatible computer, arithmetic frame grabber, frame processor and high-resolution color monitor. The neutron camera is similar to others using a silicon intensified target (SIT) television camera to provide a TV image of the low-level light from a NE 426 screen. The IRO and CCD camera are used in place of the SIT camera. The computer digitizes the TV image (512x512x8 bit) ...

Energy Technology Data Exchange (ETDEWEB)

For InAs-GaAs based quantum dot lasers emitting at 1300 nm, digital modulation showing an open eye pattern up to 12 Gb s{sup -1} at room temperature is demonstrated, at 10 Gb s{sup -1} the bit error rate is below 10{sup -12} at -2 dB m receiver power. Cut-off frequencies up to 20 GHz are realised for lasers emitting at 1.1 {mu}m. Passively mode-locked QD lasers generate optical pulses with repetition frequencies between 5 and 50 GHz, with a minimum Fourier limited pulse length of 3 ps. The uncorrelated jitter is below 1 ps. We use here deeply etched narrow ridge waveguide structures which show excellent performance similar to shallow mesa structures, but a circular far field at a ridge width of 1 {mu}m, improving coupling efficiency into fibres. No beam filamentation of the fundamental mode, low a-factors and strongly reduced sensitivity to optical feedback are observed. QD lasers are thus superior to QW lasers for any system or network. ...

CERN Document Server

Starting from the original collective Hamiltonian of Bohr and separating the beta and gamma variables as in the X(5) model of Iachello, an exactly soluble model corresponding to a harmonic oscillator potential in the beta-variable (to be called X(5)-$\\beta^2$) is constructed. Furthermore, it is proved that the potentials of the form $\\beta^{2n}$ (with n being integer) provide a ``bridge'' between this new X(5)-$\\beta^2$ model (occuring for n=1) and the X(5) model (corresponding to an infinite well potential in the beta-variable, materialized for n going to infinity. Parameter-free (up to overall scale factors) predictions for spectra and B(E2) transition rates are given for the potentials $\\beta^2$, $\\beta^4$, $\\beta^6$, $\\beta^8$, corresponding to E(4)/E(2) ratios of 2.646, 2.769, 2.824, and 2.852 respectively, compared to the E(4)/E(2) ratios of 2.000 for U(5) and 2.904 for X(5). Hints about ...

International Nuclear Information System (INIS)

This paper proposes an integrated method for using experimental data and CFD modeling to develop engineering correlations for atrium smoke management. Part I focused on the experimental program and validation of a CFD model of the experimental facility. Part II describes the extension of this model to a parametric study of balcony spill plumes. Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production or mass flow rate of the buoyant fire plume. One design issue is the mass flow rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes (BSPs) are based on a combination of one-tenth scale test data and theoretical analysis. The suitability of ...

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation of a humidification-dehumidification desalination (HDD) process using solar energy at the weather conditions of Suez City, Egypt, is presented. A test rig is designed and constructed to conduct this investigation under different environmental and operating conditions. The test rig consists of a solar water heater (concentrator solar collector type), solar air heater (flat plate solar collector type), humidifier tower and dehumidifier exchanger. Different variables are examined including the feed water flow rate, the air flow rate, the cooling water flow rate in the dehumidifier and the weather conditions. Comparisons between the experimental results and other published results are presented. It is found that the results of the developed mathematical model by the same authors are in good agreement with the experimental results. The tested results show that the productivity ...

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation of a humidification-dehumidification desalination (HDD) process using solar energy at the weather conditions of Suez City, Egypt, is presented. A test rig is designed and constructed to conduct this investigation under different environmental and operating conditions. The test rig consists of a solar water heater (concentrator solar collector type), solar air heater (flat plate solar collector type), humidifier tower and dehumidifier exchanger. Different variables are examined including the feed water flow rate, the air flow rate, the cooling water flow rate in the dehumidifier and the weather conditions. Comparisons between the experimental results and other published results are presented. It is found that the results of the developed mathematical model by the same authors are in good agreement with the experimental results. The tested results show that the productivity ...

Science.gov (United States)

The effects of 0.2 and 0.5 mL/kg Innovar (a neuroleptic analgesic) on cardiovascular functions and reflexes in rabbits were measured. We recorded the effects of Innovar on arterial pressure, heart rate, respiration rate, ventricular contractility, arterial oxygen tension, as well as the drug's effects on the bradycardia and vasoconstrictor response to cigarette smoke stimulation of the nose (the so-called "nasopharyngeal reflex"). In animals given 0.2 mL/kg Innovar, all steady state cardiovascular variables had returned to pre-Innovar levels in 45 min, as had the efficacy of the nasopharyngeal reflex. In animals given 0.5 mL/kg Innovar, all steady state cardiovascular variables, except PaO2, were slightly but significantly depressed for up to 135 min after injection. The nasopharyngeal reflex returned to normal within 90 min. Because of the calmative and analgesic effects of Innovar, and its only ...

Science.gov (United States)

Staggered arrays of dimples printed on opposite surfaces of a cooling channel is formulated numerically and optimized with hybrid multi-objective evolutionary algorithm and Pareto optimal front. As Pareto optimal front produces a set of optimal solutions, the trends of objective functions with design variables are predicted by hybrid multi-objective evolutionary algorithm. The problem is defined by three non-dimensional geometric design variables composed of dimpled channel height, dimple print diameter, dimple spacing, and dimple depth, to maximize heat transfer rate compromising with pressure drop. Twenty designs generated by Latin hypercube sampling were evaluated by Reynolds-averaged Navier-Stokes solver and the evaluated objectives were used to construct Pareto optimal front through hybrid multi-objective evolutionary algorithm. The optimum designs were grouped by k-means clustering technique and some of the clustered ...

Energy Technology Data Exchange (ETDEWEB)

As an application of ART2 neural networks, computer aided monitoring of pump efficiency is successfully examined for an industrial waste-liquid treatment process with measured data of valve openness and liquid flow rates. By running the neural networks in parallel, we confirm that accuracy to detect system changes is good, and the adjustment of classifier parameters is relatively easy. Investigating the resulting classes carefully, frequency of each class is correlated with pump efficiency. The relative amount of variables are also related to the classes. (author)

British Library Electronic Table of Contents (United Kingdom)

A web-based decision support tool, zone mapping application for precision farming (ZoneMAP, External Reference Not Shown ), has been developed to automatically determine the optimal number of management zones and delineate them using satellite imagery and field data provided by users. Application rates, such as of fertilizer, can be prescribed for each zone and downloaded in a variety of formats to ensure compatibility with GPS-enabled farming equipment. ZoneMAP is linked to Digital Northern Great Plains, a web-based application which hosts an archive of satellite imagery, as well as high resolution imagery from airborne sensors. Management zones created by ZoneMAP mapped natural variation of the soil organic matter and other nutrients relatively well and were consistent with zone maps cre...

Energy Technology Data Exchange (ETDEWEB)

An algorithm for solving the extended security constrained economic dispatch (ESCED) problem with real-time economic dispatch grade speed and reliability is presented. The ESCED problem is formulated by adding regulating margin and ramp rate constraints to the network security constrained economic dispatch problem previously solved by the CEDC algorithm. Starting with Newton`s method to optimize the Lagrangian, the ESCED is developed by superimposing on Newton`s method eight major components called Tracking Start Initialization, Hessian Pre-Elimination, Implicit Dual Variable Calculations, Regulating Margin Sensitivity Coefficient Calculations, Traumatic Event Evaluation, Constraint Relaxation, Implicit Ramp Rate Constraint Implementation, and Relaxed Incremental Cost Calculations. Test results are also presented.

Energy Technology Data Exchange (ETDEWEB)

The real thermodynamic inefficiencies in a thermal system are related to exergy destruction and exergy loss. An exergy analysis identifies the system components with the highest exergy destruction and the processes that cause them. However, only a part of the exergy destruction in a component can be avoided. A minimum exergy destruction rate for each system component is imposed by physical, technological, and economic constraints. The difference between the total and the unavoidable exergy destruction rate represents the avoidable exergy destruction rate, which provides a realistic measure of the potential for improving the thermodynamic efficiency of a component. The calculation of avoidable cost rates associated with both exergy destruction and capital investment is described in the paper and is applied to the exergoeconomic evaluation of an externally fired combined cycle power plant. For each plant ...

Energy Technology Data Exchange (ETDEWEB)

Corrosion probes are being developed and combined with an existing measurement technology to provide a tool for assessing the extent of corrosion of metallic materials on the fireside in coal-fired boilers. The successful development of this technology will provide power plant operators the ability to (1) accurately monitor metal loss in critical regions of the boiler, such as waterwalls, superheaters, and reheaters; and (2) use corrosion rates as process variables. In the former, corrosion data could be used to schedule maintenance periods and in the later, processes can be altered to decrease corrosion rates. The research approach involves laboratory research in simulated environments that will lead to field tests of corrosion probes in coal-fired boilers. Laboratory research has already shown that electrochemically-measured corrosion rates for ash-covered metals are similar to actual mass loss ...

DEFF Research Database (Denmark)

Udgivelsesdato: 1995-Nov

CERN Document Server

Computing the topology of an algebraic plane curve $\\mathcal{C}$ means to compute a combinatorial graph that is isotopic to $\\mathcal{C}$ and thus represents its topology in $\\mathbb{R}^2$. We prove that, for a polynomial of degree $n$ with coefficients bounded by $2^\\rho$, the topology of the induced curve can be computed with $\\tilde{O}(n^8(n+\\rho^2))$ bit operations deterministically, and with $\\tilde{O}(n^8\\rho^2)$ bit operations with a randomized algorithm in expectation. Our analysis improves previous best known complexity bounds by a factor of $n^2$. The improvement is based on new techniques to compute and refine isolating intervals for the real roots of polynomials, and by the consequent amortized analysis of the critical fibers of the algebraic curve.

Energy Technology Data Exchange (ETDEWEB)

Proactive qualification is today an integral part of the development process for steam turbines used in steam and combined cycle power plants. By providing experimentally based `random` variables, such as the steam path efficiency and blading reliability, it makes a valuable contribution to the economic `random` variables of the power plant, e.g. the rate of return, as viewed by the customer. One of the areas in which proactive product and process qualification plays an important role is the development of LP steam paths. (orig.) [Deutsch] Die proaktive Qualifikation ist heute fester Bestandteil des Entwicklungsprozesses bei Dampfturbinen, die fuer den Einsatz in Dampf- und Kombikraftwerken bestimmt sind. Sie leistet mit Hilfe experimentell ermittelter `Zufalls`-Variablen, wie z.B. Wirkungsgrad der Fluten und Zuverlaessigkeit der Beschaufelungen, einen wertvollen Beitrag zu den fuer die Kunden wichtigen wirtschaftlichen ...

Energy Technology Data Exchange (ETDEWEB)

A characteristic of filled elastomers is their ability to undergo very large deformations without damaging their internal structure. The material behaviour is mainly elastic, however, elastomers show hysteresis effects leading to damping properties, which are quite important as regards their applications in various fields of mechanical engineering.A series of experiments (tension, torsion and combinations of both) was carried out on cylindrical bars made of a carbon-black filled rubber mixture. In addition to a pronounced nonlinear rate-dependence, relaxation and viscosity properties are observed as being influenced by the process histories.The behaviour of elastomeric materials is modelled on the basis of a free energy function and evolution equations for additional internal variables. Incorporating or disregarding the very small rate-independent hysteresis, the constitutive modelling may be classified under ...

Science.gov (United States)

Enzymatic reactions in non-aqueous media have been shown to be effective in carrying out chemical transformation where the reactants are insoluble in water or water is a byproduct limiting conversion. Ionic liquids, liquid organic salts with infinitesimal vapor pressure, are potentially useful alternatives to organic solvents. It is known that the thermodynamic water activity is an important variable affecting the activity of enzymes in non-aqueous solvents. This study investigated the influence of water activity on the esterification of geraniol with acetic acid in ionic liquid [bmim]PF6 catalyzed by immobilized Candida antarctica lipase B. The conversion of geraniol in [bmim]PF6 was significant although the reaction rate was slower than in organic solvents. The profile of initial reaction rate-water activity was determined experimentally, and differed from the data reported for other non-aqueous solvents. A maximum in the ...

Energy Technology Data Exchange (ETDEWEB)

The proton therapy gives an irradiation adapted to the shape and the depth of tumors ( eyes, head and neck) with a millimetric, even sub millimetric precision for the ophthalmological tumors. It is equally an excellent tool for the pediatrics tumors. For numerous treatments in France the proton therapy is associated to the photons treatments (x radiation). however, others physical treatments could modulate the medical offer, such thermal therapy or treatments by ultrasonic waves. (N.C.)

UK PubMed Central (United Kingdom)

An 8-year-old child presented with severe chest pain and respiratory distress after he accidentally bit an automobile tyre tube which burst into his mouth. The chest radiograph revealed left-sided pneumothorax....Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Objectives: Acupuncture has served as a major complementary and alternative therapy that supplements conventional medicine and is the subject of growing public interest. This study was conducted to estimate the usage rate of acupuncture as a supplemental treatment in acute ischaemic stroke patients and to identify factors associated with the choice to use this therapy. Methods: Using the registry of stroke patients admitted to an academic medical centre in Korea, the use of acupuncture therapy was recorded and analysed, along with the patients' socio-demographic characteristics, hospital access variables, risk factors for ischaemic stroke and clinical characteristics. The data were analysed using descriptive statistics, chi-square tests and multiple logistic regression analyses. Results: O...

International Nuclear Information System (INIS)

An investigation of decay heat removal by the reflux boiling process was performed on a 1/18 linear-scaled test facility simulating the Three Mile Island (TMI-2) primary system. The objective was to clarify reflux boiling phenomena and core cooling effectiveness. Principal test variables included: core power, primary system water and gas inventories, and steam generator secondary-side coolant flow rate. Of 49 tests conducted, 43 achieved a steady-state heat rejection mode within 3 hours. Subsequent analyses identified two distinct reflux boiling modes. Based upon our current understanding, reflux boiling appears to be an effective process for removing decay heat in a broad range of the conditions investigated for a plant of the TMI configuration.

British Library Electronic Table of Contents (United Kingdom)

A detailed knowledge about the dynamics of phytoplanktonic photosynthesis and respiration is crucial for the determination of primary productivity in open oceans as well as for biotechnological applications. The dynamics are best studied in photobioreactors that are able to simulate natural conditions in such, that light can be modulated not only diurnally but also mimicking effects of solar elevation angle from sunrise to sunset, variable cloudiness, light modulation in refractory sun flecks due to water waves, or light intermittence due to turbulent flow in dense suspensions. In addition, high performance photobioreactors ought to be able to monitor in real time photosynthetic and respiratory activities as well as culture growth. Here, we demonstrate performance of a newly designed bench...

CERN Document Server

Numerical results on the translocation of long biopolymers through mid-sized and wide pores are presented. The simulations are based on a novel methodology which couples molecular motion to a mesoscopic fluid solvent. Thousands of events of long polymers (up to 8000 monomers) are monitored as they pass through nanopores. Comparison between the different pore sizes shows that wide pores can host a larger number of multiple biopolymer segments, as compared to smaller pores. The simulations provide clear evidence of folding quantization in the translocation process as the biopolymers undertake multi-folded configurations, characterized by a well-defined integer number of folds. Accordingly, the translocation time is no longer represented by a single-exponent power law dependence on the length, as it is the case for single-file translocation through narrow pores. The folding quantization increases with the biopolymer length, while the rate of translocated beads at each ...

Energy Technology Data Exchange (ETDEWEB)

Strain transient dip tests have been conducted on two commercial heats of Alloy 800 at 922 K. Tests were conducted on both a servo-controlled hydraulic machine and a specially designed dip test machine. Using measured maximum strain changes during dips allowed unambiguous definition of a kinematic variable. The several other methods of interpreting dip test data by attempting to measure strain rates shortly after the unloading decrements were found not to be satisfactory. The nature of the instantaneous unloading strains and the strain transients following unloading are also discussed in terms of the mechanisms of deformation in Alloy 800. 9 figures, 3 tables.

CERN Document Server

We consider the exact path sampling of the squared Bessel process and some other continuous-time Markov processes, such as the CIR model, constant elasticity of variance diffusion model, and hypergeometric diffusions, which can all be obtained from a squared Bessel process by using a change of variable, time and scale transformation, and/or change of measure. All these diffusions are broadly used in mathematical finance for modelling asset prices, market indices, and interest rates. We show how the probability distributions of a squared Bessel bridge and a squared Bessel process with or without absorption at zero are reduced to randomized gamma distributions. Moreover, for absorbing stochastic processes, we develop a new bridge sampling technique based on conditioning on the first hitting time at zero. Such an approach allows us to simplify simulation schemes. New methods are illustrated with pricing path-dependent options.

Science.gov (United States)

Digital audio sampling is explained, and some of its implications in digital sound applications are discussed. Digital sound equipment is rapidly replacing analog recording devices as the state-of-the-art in audio technology. The philosophy of digital recording involves doing away with the continuously variable analog waveforms and turning the patterns into numbers. A digital recording device rapidly samples the incoming sounds, quantifying the signal into a series of numerical values (binary codes). Although digital sound eliminates many of the traditional analog problems, digital signal processing presents key problems in sampling rates and synchronization. Careful control is necessary to check signals through each step in the audio chain. The advantages of digital audio processing include increased signal-to-noise ratio, no flutter, transparent generation of copies, and sound manipulation. These benefits come with increased quality control ...

Energy Technology Data Exchange (ETDEWEB)

Combustion characteristics of Korean anthracite in a circulating fluidized bed and freeboard were investigated. A test coal was selected with heating value of 4,429kcal/kg and ash content of 38%. Characteristics of combustion, sorbent effect on desulphurisation and emission of SO{sub x} and NO{sub x} were monitored by varying process variables such as feed rate, (Ca+K)/S ratio, and excess air ratio at the given properties of coal. Optimum operating conditions were studied by analysing: axial profiles of temperature, effect of excess air ratio, characteristics of loopseal and bag filter ashes, and emission of toxic gases. 9 refs., 9 figs., 3 tabs.

Science.gov (United States)

The vigilance reinforcement hypothesis (VRH) asserts that errors in signal detection tasks are partially explained by operant reinforcement and extinction processes. VRH predictions were tested with a computerized baggage screening task. Our experiment evaluated the effects of signal schedule (extinction vs. variable interval 6 min) and visual field complexity (dial vs. baggage x-ray) on search behavior rates. There was a main effect for signal schedule [F (1, 20) = 14.0, p = 0.001, p[subscript rep] = 0.99], but no effects for field complexity or interaction. The VRH suggests that performance errors in visual screening work may be reduced through operant conditioning of search behaviors by intensive management of artificially planted signals. (Contains 1 table and 3 figures.)

Energy Technology Data Exchange (ETDEWEB)

A series of OSL properties of fragments from split feldspar grains have been investigated. These are (1) the response to a radiation dose, (2) the recycling of corrected induced luminescence (L{sub i}/T{sub i}), (3) the corrected natural luminescence (L{sub N}/T{sub N}), (4) the corrected thermal transfer luminescence (termed herein L{sub tt}/T{sub tt}) and, (5) the rate of anomalous fading ('g'). It was found that the parameters of different parts of the same grain are the same. The relative uncertainty, at the 2 sigma level, at which we can claim that the measured parameters are correlated, is generally less than 5% but is ca 40% for the anomalous fading rate due to measurement uncertainty. For young partially bleached sediments, the result is that one could use one fragment to evaluate the equivalent dose and another to assess the contribution of thermal transfer resulting from preheating the natural luminescence.

Energy Technology Data Exchange (ETDEWEB)

Simplifying hypotheses are required when combustion and aerodynamic phenomena are considered simultaneously. In this paper, a turbulent combustion model is proposed, in which the combustion chemistry is reduced to a single reaction. In this way, only two variables are needed to describe the problem and combustion can be characterized by the consumption of one of the two reactive species. In a first step, the instantaneous consumption rate is obtained using the Lagrangian form of the mass fraction equation of the species under consideration, and by considering the equilibrium state only. This state is determined in order to preserve the consistency with results that should be obtained using a complete kinetics scheme. In a second step, the average rate is determined using the instantaneous consumption term and a probabilistic density function. This model was tested on various configurations and in particular on an ...

CERN Document Server

For purposes of designing targeted cataclysmic variable (CV) detection surveys and interpreting results of other projects with many CV detections such as the ChaMPlane Survey, we have created a model of the CV distribution in the Galaxy. It is modeled as a warped, flared exponential disk with a gaussian vertical distribution. Extinction is based on a detailed Galactic dust and gas model. A luminosity function for CVs is also incorporated, based on a smoothed version of published data. We calculate predicted field detection rates as a function of the limiting magnitude expected for the detecting system (i.e. WIYN/Hydra or NOAO 4m/Mosaic). Monte-Carlo techniques are used to assess statistical fluctuations in these rates. We have created maps of the expected CV distribution for the full non-bulge Galactic plane (20

Energy Technology Data Exchange (ETDEWEB)

The basic principle of the green building philosophy is to design buildings that consider environmental performance. Residential and commercial buildings in Canada consume about 30 per cent of the total secondary energy use and are responsible for approximately 29 per cent of carbon dioxide equivalent greenhouse gas emissions and many other wastes. An optimization model was developed which minimizes life cycle cost and life cycle environmental impact. The model distinguishes different energy sources and incorporates their impacts, such as resource depletion, global warming and acidification. The model also considers design variables such as window type, orientation, building orientation, window-to-wall ratio, wall type and roof type. The model can be used to identify optimum green building designs for given conditions. The model uses expanded cumulative exergy consumption as the indicator for life cycle environmental performance. As such, it can be simplified by ...

Energy Technology Data Exchange (ETDEWEB)

Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production rate of the buoyant fire plume. One design issue is the smoke production rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes are based on a combination of one-tenth scale test data and theoretical analysis. Questions have arisen over the suitability of these correlations for real-scale designs. A combined program of full-scale experimentation and CFD modeling is being conducted to analyze the accuracy of these correlations. A full-scale experimental facility was constructed with a 5 m by 5 m by 15 m fire compartment connected to a four-story atrium. Propane fires in the ...

International Nuclear Information System (INIS)

Perspectives from industry, academe, and the NRC are brought together in this report and used to develop a logical framework that links management and organization factors and safety in nuclear power plant performance. The framework focuses on intermediate outcomes which can be predicted by organizational and management factors, and which are subsequently linked to safety. The intermediate outcomes are efficiency, compliance, quality, and innovation. The organization and management factors can be classified in terms of environment, context, organizational governance, organizational design, and emergent processes. Initial empirical analyses were conducted on a limited set of hypotheses derived from the framework. One set of hypotheses concerned the relationships between one of the intermediate outcome variables, efficiency, as measured by critical hours and outage rate, and safety, as measured by 5 NRC indicators. Results of the analysis suggest ...

Energy Technology Data Exchange (ETDEWEB)

A quantum computer would put the latest PC to shame. Not only would such a device be faster than a conventional computer, but by exploiting the quantum-mechanical principle of superposition it could change the way we think about information processing. However, two key goals need to be met before a quantum computer becomes reality. The first is to be able to control the state of a single quantum bit (or 'qubit') and the second is to build a two-qubit gate that can produce 'entanglement' between the qubit states. (U.K.)

Science.gov (United States)

With major D&D projects ongoing or being planned, and also with the daily management of radwaste from nuclear facilities, the potential role of transport packagings has often been overlooked: here will one rely essentially on drums, there several local waste processing units are built, elsewhere decommissioned facilities are cut in small bits to fit into small containers by far less efficient. The present paper proposes to illustrate how integrating a transport system from the start may influence operational choices of waste management.

KoreaScience (Korea)

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KoreaScience (Korea)

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International Nuclear Information System (INIS)

... biological variability body distribution kidneys labelled compounds lead 203

International Nuclear Information System (INIS)

We revisit our original papers on the burst mode of accretion by incorporating a detailed energy balance equation into a thin-disk model for the formation and evolution of circumstellar disks around low-mass protostars. Our model includes the effect of radiative cooling, viscous and shock heating, and heating due to stellar and background irradiation. Following the collapse from the prestellar phase allows us to model the early embedded phase of disk formation and evolution. During this time, the disk is susceptible to fragmentation, depending upon the properties of the initial prestellar core. Globally, we find that higher initial core angular momentum and mass content favors more fragmentation, but higher levels of background radiation can moderate the tendency to fragment. A higher rate of mass infall onto the disk than that onto the star is a necessary but not a sufficient condition for disk fragmentation. More locally, both the Toomre Q-parameter needs to be ...

International Nuclear Information System (INIS)

The formation and evolution of the circumstellar disk in unmagnetized molecular clouds is investigated using three-dimensional hydrodynamic simulations from the prestellar core until the end of the main accretion phase. In collapsing cloud cores, the first (adiabatic) core with a size of #approx#>3 AU forms prior to the formation of the protostar. At its formation, the first core has a thick disk-like structure and is mainly supported by the thermal pressure. After the protostar formation, it decreases the thickness gradually and becomes supported by the centrifugal force. We found that the first core is a precursor of the circumstellar disk with a size of >3 AU. This means that unmagnetized protoplanetary disk smaller than <3 AU does not exist. Reflecting the thermodynamics of the collapsing gas, at the protostar formation epoch, the first core (or the circumstellar disk) has a mass of #approx#0.005-0.1 M_s_u_n, while the protostar has a mass of #approx#10"-"3 M_s_u_n. Thus, ...

International Nuclear Information System (INIS)

Attention is given to the folowing topics: population I and II variable stars; LP variables, the sun, and mass determination; and predegenerate and degenerate variables. Particular papers are presented on alternative evolutionary approaches to the absolute magnitude of the RR Lyrae variables; the evolution of the Cepheid stars; nonradial pulsations in rapidly rotating Delta Scuti stars; dynamical models of dust shells around Mira variables; and pulsations of central stars of planetary nebulae.

Energy Technology Data Exchange (ETDEWEB)

The aim of the thesis is to validate concepts used in hydrocarbon generation and migration models; the model considered is the Temispack model developed by IFP, and the validation is based on the investigation of the thermal and hydraulic evolution in various sedimentary basins. It is shown that, in general, the thermal history of sediments is influenced by external processes (sedimentation rates, lithology, climate changes, regional-scale groundwater circulations) which frequently overprint internal processes (variations of crustal/mantle heat flow). It is found that external processes can frequently explain past thermal events that were erroneously attributed to internal causes (tectonic-thermal events). The origin of over-pressures in young basins with high sedimentation rates is shown to be generally related to compaction disequilibrium. Shale permeability values calibrated against overpressure profiles are consistent with experimental ...

Energy Technology Data Exchange (ETDEWEB)

The temporal evolution of linear toroidal ion temperature gradient (ITG) modes is studied based on a kinetic integral equation including an initial condition. It is shown how to evaluate the analytic continuation of the integral kernel as a function of a complex-valued frequency, which is useful for analytical and numerical calculations of the asymptotic damping behavior of the ITG mode. In the presence of the toroidal {nabla}B-curvature drift, the temporal dependence of the density and potential perturbations consists of normal modes and a continuum mode, which correspond to contributions from poles and from an integral along a branch cut, respectively, of the Laplace-transformed potential function of the complex-valued frequency. The normal modes have exponential time dependence with frequencies and growth rates determined by the dispersion relation while the continuum mode, which has a ballooning structure, shows a power law decay {proportional_to} t{sup -2} in ...

Energy Technology Data Exchange (ETDEWEB)

There are a number of characteristics exhibited by ceramic materials that may provide potential benefits for the reciprocating internal combustion engine. However, the brittle nature of these materials together with a variability in strength has created difficulties in applying ceramic materials to the engine environment. Although a wide range of physical properties is available from contemporary ceramic materials, a material offering consistently high strength has yet to be developed. For sliding-contact applications, desirable characteristics include good wear resistance, low friction, ability to join metals and good heat dissipation. Test results have shown that cam/follower components with cast iron cam sliding on a silicon nitride follower exhibit very low wear rates. The application of silicon carbide to face seals has also shown substantial reductions in both friction and wear when compared with conventional materials. The use of ceramic ...

International Nuclear Information System (INIS)

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking and ignition limits are presented as torque output at the onset of knocking and ignition failure. Experimental investigation on the dual fuel engine revealed the noise generated from combustion, knocking and ignition limits for all gases at different design and operating conditions. A Ricardo E6 Diesel version engine is converted to run on dual fuel of Diesel and the tested gaseous fuel and is used throughout the work. The engine is fully computerized, and the cylinder pressure data, crank angle data and engine operating variables are stored in a PC for off line ...

Energy Technology Data Exchange (ETDEWEB)

A spectral element method embodying Large Eddy Simulation based on Re- Normalization Group theory for simulating Sub Grid Scale viscosity was chosen for this work. This method is embodied in a computer code called NEKTON. NEKTON solves the unsteady, 2D or 3D,incompressible Navier Stokes equations by a spectral element method. The code was later extended to include the variable density and multiple reactive species effects at low Mach numbers, and to compute transport of large particles governed by inertia. Transport of small particles is computed by treating them as trace species. Code computations were performed for a number of test conditions typical of flow past a deep tube bank in a boiler. Results indicate qualitatively correct behavior. Predictions of deposition rates and deposit shape evolution also show correct qualitative behavior. These simulations are the first attempts to compute flow field results at realistic flow Reynolds numbers ...

International Nuclear Information System (INIS)

A pilot project was started in 1977 over the Lake Superior basin to measure water storage on the land area using aerial gamma-ray spectrometry to provide hydrologic information for forecasting inflow to the lake. Two airborne surveys were made, respectively in November 1977 and March 1978 which provided estimates of the increase in snow water equivalent between these surveys. The basin is located on the Canadian Shield and consequently, the gamma radiation count rate is quite variable. The airborne results are compared with ground measurements on selected flight lines and show generally good agreement. Two equipment calibrations in the Ottawa area provided inconsistent parameter values which are consequently also reflected in the results over the Lake Superior basin. The project has demonstrated to-date that the technique can be developed into an operational system for measuring snow cover water equivalent of this vast and remote area by using ...

British Library Electronic Table of Contents (United Kingdom)

Fresh tree root decomposition induced by tillage is an important source of soil nutrients in agroforestry systems. Here we examined the effects of tree species, root size and soil N enrichment on fresh root decomposition under laboratory conditions. Fresh roots with two diameters (<2 and 2?5?mm) of Populus euramericana cv. ?N3016? (poplar) and Pinus tabulaeformis (pine) collected from agroforestry systems in Northeast China were used in the experiment. For each root treatment, four N levels (0, 50, 100 and 150??g?N g?1 soil) were added. We recognized N concentration and C/N ratio as the root quality variables, and determined decomposition rates as cumulative CO2 production and mass loss. Poplar roots had higher N concentration and lower C/N ratio and decomposed faster than pine roots, and ...

Energy Technology Data Exchange (ETDEWEB)

In this paper, an empirical model is developed for electricity consumption of the Jordanian industrial sector based on multivariate linear regression to identify the main drivers behind electricity consumption. In addition, projection of electricity consumption for the industrial sector based on time series forecasting is presented. It was found that industrial production outputs and capacity utilization are the two most important variables that affect demand on electrical power and the multivariate linear regression model can be used adequately to simulate industrial electricity consumption with very high coefficient of determination. To illustrate the importance of integrating energy efficiency within national energy plans, the impact of implementing high-efficiency motors was investigated and found to be significant. Without such basic energy conservation and management programs, electricity consumption and associated GHG emissions for the industrial sector are ...

Energy Technology Data Exchange (ETDEWEB)

The proper selection of materials of construction is necessary to provide process equipment with optimum performance and corrosion resistance. If properly chosen, the selected material should deteriorate at a uniform, predictable rate, which will allow for maintenance or replacement at scheduled intervals. This concept of risk assessment for predictive maintenance is a minimum requirement for proper materials selection. Materials selection is based on prior service history, field corrosion tests, pilot-plant tests, and laboratory bench-top tests--in that relative order of usefulness. Corrosion test methods are usually divided into two groups: laboratory and field (plant-site) tests. The main difference between the two is that field test specimens are exposed to actual process conditions will all of the variables involved, while laboratory tests are a simulation of field conditions, even if actual process fluids are involved. The paper ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes the design and feasibility tests of a 570 mm bore 4 stroke low pressure (L.P.) dual fuel engine rated at 20.9 bar BMEP meant for the propulsion of LNG carriers. The basic design features which are to be in accordance with classification societies safety rules are described: individual electro hydraulic valves located in the air manifold ducts, pilot injection, monitoring system etc. The engine capability to burn variable liquid/gas fuel proportions have been investigated with diesel oil and heavy fuel and possible running zones are defined. This ensures the possibility of the engine to cope with the different boil off gas quantity emanating from the ship`s tank during her loaded - and ballast - journeys. With the very lean setting of this engine, no adverse influence of the high ash lube-oil additives were found during the tests. Further tests are necessary to confirm that possible more significant fouling of the combustion ...

Energy Technology Data Exchange (ETDEWEB)

A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. (Several attributes that make CBCF particularly suitable for the heat source application have been identified.) These include light weight, low thermal conductivity, chemical compatibility, and hightemperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific properties of the CBCF were tailored by adjusting ...

British Library Electronic Table of Contents (United Kingdom)

One method of increasing juvenile fish escapement from net cod-ends is to encourage fish to approach the netting by placing an active stimulating device (ASD) in the cod-end. Two types of ASD were tested inside model cod-ends to generate variable visual stimuli. One was a free-end flag-like net panel and the other consisted of an array of free-ended ropes. Escape responses of juvenile red seabream were observed in a circulating water channel using a cod-end fitted with the ASD, and they were compared with responses to conventional polyethylene multi-ply, high-contrast cod-ends with and without ASD made from either 28- or 43-mm mesh under three light conditions. With the ASD attached, the retention rate was significantly lower, 20%, than for conventional cod-ends except in dim light with 28...

Energy Technology Data Exchange (ETDEWEB)

The role played by planetary boundary layer (PBL) in the development and evolution of a severe convective storm is studied by means of meso-scale modeling and surface and upper air observations. The severe convective precipitation event that occurred on 14 September 1999 in the northeast of the Iberian Peninsula was simulated by means of the mesoscale model MM5 (version 3) using three different PBL schemes. The numerical results show a large impact of the PBL schemes on the precipitation fields associated to the convective storm. The schemes are based on different physical assumptions: the nonlocal first order medium-range forecast (MRF) and blackadar (BLA) scheme and the local, one-and-a-half order ETA scheme. Surface and radar observations are used to validate the model results. The comparison focuses on three aspects: the evolution, the spatial distribution and the 24-h accumulated precipitation. The comparison with rain gauge observations shows that the MRF, BLA and ETA schemes ...

International Nuclear Information System (INIS)

An experimental investigation of the effect of nickel content on irradiation hardening of reactor pressure vessel steels was conducted. The alloys studied, with nickel contents ranging from 0 to 1.7%, included five sets of steels representing variations in copper contents and other metallurgical variables. Various subsets of the alloys were irradiated at selected combinations of flux, fluence, and irradiation temperature. Irradiation hardening was measured by either changes in the uniaxial yield stress or diamond pyramid hardness. Higher hardening rates with increasing nickel were observed in controlled experiments on commercial-type steels containing high copper concentrations (0.4% Cu). The effect of nickel increased with increasing fluence and decreasing temperature. At high fluence (>10"1"9 n/cm"2) the hardening increased with nickel at an average rate of about 100 MPa/%Ni. There also appeared to be an influence of ...

International Nuclear Information System (INIS)

The HT-28 and 29 irradiation capsules are part of a cooperative agreement between GA and ORNL designed to evaluate irradiation performance of unbonded BISO and TRISO coated ThO_2 fertile fuel particles. The capsules will contain a total of 44 different positions uniformly divided between each capsule. The positions in HT-29 are designated for operation at 900"0C over a fast fluence increment between 5.4 to 10.7 x 10"2"1 n/cm"2 (E > 0.18 MeV)/sub HFIR/. Positions in HT-28 are divided into two sections: 11 positions at 1250"0C to receive a fast fluence exposure between 7.8 and 8.6 x 10"2"1 n/cm"2 (E > 0.18 MeV)/sub HFIR/ and 11 positions at 900"0C designed for a 4.3 to 6.9 x 10"2"1 n/cm"2 (E > 0.18 MeV)/sub HFIR/ fast fluence exposure. Both capsuls are to serve as an evaluation test to characterize the performance of BISO OPyC coatings deposited from mixed-gas (acetylene-propylene). The OPyC variables tested will be density, coating ...

Energy Technology Data Exchange (ETDEWEB)

The physical structure of a limestone or dolomite to be used in in-bed sulfur capture in fluidized bed boilers has great impact on the efficiency of sulfur capture and sorbent use. Therefore in process optimization and model calculations parameters describing the pore structure of these sorbents must be included. In this study an unreacted shrinking core model with variable effective diffusivity is applied to sulfation test data from a pressurized thermogravimetric apparatus (P-TGA) for various limestone and dolomite samples. The particle size was 250--300 {micro}m for all sorbents. The tests were done under typical conditions for a pressurized fluidized bed combustor, i.e. 850 C or 950 C, 15 bar, and were reported earlier at the 12th International Conference on Fluidized Bed Combustion. At these conditions the limestone remains uncalcined, while the dolomite is half-calcined. The sorbents were characterized by chemical composition analysis, particle density ...

International Nuclear Information System (INIS)

I present an exact calculation of free-electron-laser (FEL) eigenmodes (fundamental as well as higher order modes) in the exponential-gain regime. These eigenmodes specify transverse profiles and exponential growth rates of the laser field, and they are self-consistent solutions of the coupled Maxwell-Vlasov equations describing the FEL interaction taking into account the effects due to energy spread, emittance and betatron oscillations of the electron beam, and diffraction and guiding of the laser field. The unperturbed electron distribution is assumed to be of Gaussian shape in four dimensional transverse phase space and in the energy variable, but uniform in longitudinal coordinate. The focusing of the electron beam is assumed to be matched to the natural wiggler focusing in both transverse planes. With these assumptions the eigenvalue problem can be reduced to a numerically manageable integral equation and solved exactly with a kernel ...

Science.gov (United States)

Medetomidine and fentanyl-droperidol (Innovar-vet) were assessed over a three hour period in 80 healthy dogs. Following physical examination, electrocardiogram (ECG), arterial blood sample analysis, and dynamometer pressure threshold (analgesia score), the dogs were randomly assigned to one of four treatments: Miv--medetomidine (750 micrograms/M2) administered intravenously (IV), Mim--medetomidine (1000 micrograms/M2) administered intramuscularly (IM), Iiv--Innovar-vet IV (0.05 mL/kg) or Iim--Innovar-vet IM (0.1 mL/kg). All assessments were carried out by a single individual unaware of the treatment used. Objective assessments included temperature, heart and respiratory rates, analgesia score, arterial blood gases, acid-base and lactate levels. Subjective evaluation included degree of sedation, response to various clinical procedures, noise responsiveness, posture, and the incidence of side effects. Onset and duration of effect were also recorded. The ECG strips ...

Energy Technology Data Exchange (ETDEWEB)

In large samples, the {gamma}-ray count rate of a prompt gamma neutron activation analysis system is a multi-variable function of the elemental dry composition, density, water content and thickness of the material. The experimental calibration curves require tremendous laboratory work, using a great number of standards with well-known compositions. Although a Monte Carlo simulation study does not avoid the experimental calibration work, it reduces the number of experimental calibration standards. This paper is part of a feasibility study for a PGNAA system for on-line continuous characterisation of cement raw material conveyed on a belt (Oliveira, C., Salgado, J. and Carvalho, F. G. (1997) Optimisation of PGNAA instrument design for cement raw materials using the MCNP code. J. Radioanal. Nucl. Chem. 216(2), 191-198; Oliveira, C., Salgado, J., Goncalves, I. F., Carvalho, F. G. and Leitao, F. (1997a) A Monte Carlo study of the influence of ...

UK PubMed Central (United Kingdom)

Variability in motor performance decreases with practice but is never entirely eliminated, due in part to inherent motor noise. The present study develops a method that quantifies how performers...Full Text Available

UK PubMed Central (United Kingdom)

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and...Full Text Available

UK PubMed Central (United Kingdom)

This work reports the design of and experimentation with a topographically patterned cell culture substrate of variable local density and anisotropy as a facile and efficient platform to guide...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundIn cancer research, most clinical variables have already been investigated and are now well established. The use of transcriptomic variables has raised two problems: restricting...Full Text Available

ScienceCinema

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

Science.gov (United States)

We present a quantum secure direct communication scheme achieved by swapping quantum entanglement. In this scheme a set of ordered Einstein-Podolsky-Rosen (EPR) pairs is used as a quantum information channel for sending secret messages directly. After insuring the safety of the quantum channel, the sender Alice encodes the secret messages directly by applying a series local operations on her particle sequences according to their stipulation. Using three EPR pairs, three bits of secret classical information can be faithfully transmitted from Alice to remote Bob without revealing any information to a potential eavesdropper. By both Alice and Bob's GHZ state measurement results, Bob is able to read out the encoded secret messages directly. The protocol is completely secure if perfect quantum channel is used, because there is not a transmission of the qubits carrying the secret message between Alice and Bob in the public channel.

Science.gov (United States)

Based on the idea of dense coding of three-photon entangled state and qubit transmission in blocks, we present a multiparty controlled quantum secret direct communication scheme by using Greenberger Horne Zeilinger state. In the present scheme, the sender transmits three bits of secret message to the receiver directly and the secret message can only be recovered by the receiver under the permission of all the controllers. All three-photon entangled states are used to transmit the secret message except those chosen for eavesdropping check and the present scheme has a high source capacity because Greenberger Horne Zeilinger state forms a large Hilbert space.

International Nuclear Information System (INIS)

The purpose of the present study is to develop a new method for chemical state analysis by means of EPMA(Electron probe microanalyser). The measured X-ray intensity of Si-K#beta# characteristic X-ray spectra were read-out by a 16 bit microcomputer with a RS-232C interface. And using the curve fitting method the quantitative analysis of chemical compositions in a ternary compound that constituted of the same element has been established. The present method was applied to analyse of the friction and wear properties of Si-base ceramics sliding materials. It was found that the wear debris contains both the compositions of the sliding materials and SiO_2, and the SiO_2 contents in wear debris was changed with relative humidity. The results clearly showed that the proposed method is very useful for determing the compositions in the ternary compound. (author).

Science.gov (United States)

In this paper an efficient quantum secure direct communication (QSDC) scheme with authentication is presented, which is based on quantum entanglement and polarized single photons. The present protocol uses Einstein-Podolsky-Rosen (EPR) pairs and polarized single photons in batches. A particle of the EPR pairs is retained in the sender's station, and the other is transmitted forth and back between the sender and the receiver, similar to the ``ping-pong'' QSDC protocol. According to the shared information beforehand, these two kinds of quantum states are mixed and then transmitted via a quantum channel. The EPR pairs are used to transmit secret messages and the polarized single photons used for authentication and eavesdropping check. Consequently, because of the dual contributions of the polarized single photons, no classical information is needed. The intrinsic efficiency and total efficiency are both 1 in this scheme as almost all of the instances are useful and each EPR pair can be ...

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Recent developments in the analysis of Mira atmosphere, the determination of the pulsation mode, the problem of mass loss, and the evolution of the Mira variables are covered. Model atmospheres for Mira variables, including the opacities of the molecules expected in very late M-type atmospheres are discussed. The pulsation constant for Omicron Ceti is evaluated using T(eff) = 2900 + or - 200 K, and it is concluded that Miras are fundamental mode pulsators. The importance of molecular opacity to the driving of mass loss is evaluated, and it is pointed out that the radiation pressure on molecules is not a major factor in driving mass loss from Mira. Mass loss is considered as a factor in the calculations of the periods for Mira variables. 30 refs.

Science.gov (United States)

... AIR TRAFFIC, TERMINAL FLIGHT ... FLIGHT, RANDOM VARIABLES, STOCHASTIC PROCESSES ... COMPUTER PROGRAMS, QUEUEING THEORY. ...

CERN Document Server

In this paper, we derive the moderate deviation principle for stationary sequences of bounded random variables with values in a Hilbert space. The conditions obtained are expressed in terms of martingale-type conditions. The main tools are martingale approximations and a new Hoeffding inequality for non adpated sequences of Hilbert-valued random variables. Applications to Cramer-Von Mises statistics, functions of linear processes and stable Markov chains are given.

International Nuclear Information System (INIS)

In recent years there has been a renewed interest in the treatment of quantum mechanics in terms of joint distribution functions, i.e. functions of momentum and position coordinates p and q. The author considers j.d.f. in the sense of classical probability theory of a stochastic variable. The j.d.f. is then interpreted as the probability that the variables p and q have certain values, the variables being considered as a property possessed by the object system. This formalism is used to provide a unified description of bradyons and tachyons. (Auth.).

Science.gov (United States)

A methodology and hypothetical case study are presented for incorporation of uncertainty and variability into calculations of human health risk appropriate for regional, or basin-scale, groundwater management problems. Uncertainty in well water concentration is introduced through complex contaminant migration patterns in the subsurface. Variability is considered in parameters related to individual behavior patterns and biological effects and to groundwater extraction and distribution networks. A joint uncertainty and variability (JUV) analysis is used to generate a two-dimensional distribution or risk surface that spans both transport uncertainty as well as individual variability. Cuts in this distributional surface (fractiles of variability and percentiles of uncertainty) are presented and discussed. Comparisons with alternative approaches based upon deterministic transport models ...

International Nuclear Information System (INIS)

Quantitative evaluation of CRT and CR observations in indentification of malignancy using phantom and clinical data. A breast phantom and a total of 40 patients were imaged by Fuji computed radiography (FCR). The images were interpreted twice by six radiologists both on CR film (2510 x 2000 pixels x 10 bits, 0.1 mm spatial resolution) and on a CRT monitor (1568 x 1152 pixels x 10 bits, 0.1 mm pixel size with double expansion) with image processing parameters of a toutine (RN 1.0, RE 0.2), for a calcification (RN 9.0, RE 4.0) and for a mass (RN 7.0, RE 2.0). The forty clinical cases included breast diseases with calcifications, masses, and normal breasts. Two-tailed t-test was performed to analyze interpretation of simulated microcalcifications and masses in the phantom. The receiver operating characteristic (ROC) analysis was performed to evaluate clinical cases. In all interpretation studies using both breast phantom and clinical cases, there ...

Energy Technology Data Exchange (ETDEWEB)

It has often been proposed that track diameter in etched detectors can be used for energy spectrometry. To test this proposition, the relationship between track diameter and energy of alpha particles, in the range 0.1-5.5 MeV, incident on CR-39 was studied. Two sets of detectors were irradiated by a collimated normally-incident beam of {alpha}-particles of different energies, using an Am-241 source. Different foils of the first set were etched for variable lengths of time in such a way that, in each case, the etchant reached the end of the latent track. Foils in the second set were etched for a fixed 'short' time of 2 h, for all {alpha}-energies. The linear rate of energy loss as well as the residual range of {alpha}-particles was determined by using Henke and Benton's computer program. It is found that, for 'short' etching times, the track diameter mimics the 'Bragg curve', i.e., ...

Energy Technology Data Exchange (ETDEWEB)

The SGTR project has been carried out within the fifth EURATOM Framework Programme (Contract No FIKS-CT-1999-0007). Its main objective was to provide an experimental database and to develop and/or verify models to support definition of accident management measures in the hypothetical case of a Steam Generator tube Rupture (SGTR) sequence. The project addressed both vertical and horizontal steam generator designs. This report summarises the main results obtained in the intermediate scale experimentation that addressed Western type steam generators. The specific goal of this test programme was to investigate aerosol retention in the break stage of the secondary side of a water-empty steam generator. The test matrix consisted of 12 tests that explored the influence of variables such as break type and orientation and inlet gas flow rate. This work was performed in the PECA facility of the Laboratory for Analysis of Safety Systems (LASS). Aerosol ...

International Nuclear Information System (INIS)

Purpose: To evaluate the results of radiotherapy in cholangiocarcinoma patients managed with various combinations of chemotherapy and surgical resection with selective liver transplantation. Methods and Materials: From January 1990 to December 1995, 61 patients with histologically confirmed biliary duct adenocarcinoma were seen in the Radiation Oncology Department of the University of Pittsburgh. Median follow-up was 22 months (1 to 91 months). The extent of surgery was complete resection in 23 patients (including 17 with orthotopic liver transplant), partial resection in 4, and biopsy in 34. All patients had radiotherapy; median dose was 49.5 Gy. Thirty patients received chemotherapy: 5-fluorouracil (5-FU)-leucovorin with interferon alpha (IFN#alpha#) in 27, and taxol in 3. Results: The median survival was 20 months (95% CI 15-25 months). The 5-year actuarial survival was 23.8 #+-# 6.8%. The only significant variable in multivariate analysis was achieving a ...

Energy Technology Data Exchange (ETDEWEB)

The reactions of CF{sub 3}O radicals with (1) NO and (2) NO{sub 2} were studied using two different experimental techniques. A laser photolysis/LIF detection method was applied for measuring the rate constants as a function of temperature (T=222-302 K) and total pressure (p{sub tot}=7-107 mbar). Whereas the reaction with (1) NO was found to be independent of temperature and pressure with k{sub 1}=(4.5{+-}1.2) x 10{sup -11} cm{sup 3}s{sup -1}, the reaction with (2) NO{sub 2} was found to be dependent on both of these variables. The temperature dependence of k{sub 2} in the high pressure limit can be given by the expression k{sub 2{infinity}}{sup -}(T)=(8{+-}5) x 10{sup -13} exp ((863{+-}194) K/T) cm{sup 3}s{sup -1}. The product distributions of the two reactions were determined in separate experiments using steady-state photolysis combined with FTIR spectroscopy. For reaction (1) only CF{sub 2}O was found as a reaction product with a yield of ...

Energy Technology Data Exchange (ETDEWEB)

Coal may be used to generate electrical energy by any of several processes, most of which involve combustion or gasification. Combustion in a coal-fired boiler and power generation using a steam- cycle is the conventional conversion method; however, total energy conversion efficiencies for this type of process are only slightly over 30{percent}. Integration of a gas-cycle in the process (combined cycle) may increase the total conversion efficiency to 40{percent}. Conversion processes based on gasification offer efficiencies above 50{percent}. H{sub 2}S is the predominant gaseous contaminant in raw coal gas. Problems arise due to the corrosive nature of H{sub 2}S on metal components contained in these cycles. Because of this, H{sub 2}S concentrations must be reduced to low levels corresponding to certain power applications. An advanced process for the separation of hydrogen sulfide (H{sub 2}S) from coal gasification product streams through an electrochemical membrane is being developed ...

Energy Technology Data Exchange (ETDEWEB)

Cassava is cultivated almost all over the world and it is considered one of the most important nutritious sources of calories in the human diet. Cassava is a viable food against starvation in several poor areas of the world because it is an extremely resistant culture and may reach satisfactory economical yield. We utilized vacuum packed industrialized cassava irradiated with 0,1 kGy, 3kGy and 5kGy and stored under refrigeration for 1, 21, 30 and 50 days. Our objective was to analyse the synergistic effect of vacuum packing, irradiation and refrigeration on the preservation of minimally processed cassava. The samples were analyzed for pH, acidity, weight, humidity, texture and color. The irradiation did not affect the chemical characteristics of the cassava. Neither the pH nor the acidity, the most relevant variables to verify deterioration in cassava, presented significant alterations during the period of storage. Comparing the irradiated treatments, the dose of ...

Energy Technology Data Exchange (ETDEWEB)

The accurate measurement of a stress level is one of the most important issues in a stress diagnosis and its measurement could be of great value in clinical medicine. Stress has a potent effect on the spirit and physical condition of an individual. There are various methods available for its measurement. Some of the commonly used techniques for the diagnosis of a stress level include analysis of the body fluids, questionnaire assessments, psychophysiological evaluations and by determining heart rate variability (HRV) of subjects. However, the existing diagnostic methods have several defects like, a low sensitivity, inaccuracy and long of operation time. In this report, we present a diagnostic technology to detect a stress level which is the origin of various diseases. This method can be of great help in providing an early diagnosis through a biosensor and might play a vital role in preventing diseases like hypochondria and hypertension. ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

Energy Technology Data Exchange (ETDEWEB)

Tectonically active basins may host a spectrum of sequence stratigraphic expressions previously considered to be spatially mutually exclusive. In low accommodation areas with high sediment supply, fourth order eustatic cyclicity results in high frequency sequence sets while within rapidly subsiding areas, time-equivalent Type-2 sequences are expressed by highly asymmetrical coarsening upward successions, resembling large parasequences. In the shallow marine Fulmar Formation, of the U.K. North Sea Central Graben a sequence boundary and overlying lowstand deposits, which illustrate the effects of laterally variable subsidence rate and intrabasinal topography on the expression of a eustatic sea-level fall, lie between the Glosense and Serratum (J54a and J54b) maximum flooding surfaces. The syn-rift physiography comprises major tilted fault blocks, with the Central Graben dipping parallel to the major faults, simulating a ramp setting. Where the ...

Energy Technology Data Exchange (ETDEWEB)

Dimensional variability studies and published dimensional variability standards have been used by the foundry industry for years as an indicator of the casting process` ability to produce uniform parts. These studies are an extremely useful tool in the continuous ``dimensional dialogue`` between foundries and customers. The nature of these studies, and of the current tolerancing systems used by casting designers, leaves room for some misinterpretation and misuse of these study results. This paper contains two important discussions. The first part explains exactly what these studies represent. Following this is a brief explanation on dimensional and geometric tolerances and how they communicate dimensional requirements.

Energy Technology Data Exchange (ETDEWEB)

In this talk, we explore the feasibility of quantum computation using continuous-variable systems by means of local measurements only. In the first part of the talk, we will identify crucial limitations that arise when starting from Gaussian cluster states. This is done by resorting to a Gaussian projected entangled pair picture as well as to notions of continuous-variable quantum repeater networks. In the second part, we look at instances in which these limitations can be overcome, and how suitable encodings of qubits in oscillators and feasible non-Gaussian resource states give rise to universal schemes for quantum computing.

UK PubMed Central (United Kingdom)

Background and ObjectivePulsed dye laser (PDL) treatment of cutaneous vascular lesions is associated with variable and unpredictable efficacy. Thus, alternative treatment...Full Text Available

International Nuclear Information System (INIS)

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

Science.gov (United States)

... and operation of marine structures and to estimate coastal sediment transport. While the timely collection and report of high ... ...

UK PubMed Central (United Kingdom)

Brains are usually described as input/output systems: they transform sensory input into motor output. However, the motor output of brains (behavior) is notoriously variable, even under identical sensory...Full Text Available

CERN Document Server

In this paper we present a complete solution to the problem of multifractal analysis of multiple ergodic averages in the case of symbolic dynamics for functions of two variables depending on the first coordinate.

Science.gov (United States)

Jul 25, 2011 ... Koji Mukai's Bibliography. Invited Reviews. Mukai, K. 1994, "ASCA PV Phase Observations of Cataclysmic Variables," in "New Horizon of X-ray ...

UK PubMed Central (United Kingdom)

Background and AimsAnnonaceae are one of the largest families of Magnoliales. This study investigates the comparative floral development of 15 species to understand the basis for...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Knowledge on environmental variability and how it is affected by disturbances is crucial for understanding patterns of biodiversity and determining adequate conservation strategies. The aim of this study is to assess environmental variability in patches undergoing post-fire vegetation recovery, identifying trends of change and their relevant drivers. We particularly evaluate: the value of three spectral indices derived from Landsat satellite data [Normalized Burn Ratio (NBR), Normalized Difference Vegetation Index (NDVI) and Wetness Component of the Tasseled Cap Transformation (TCW)] for describing secondary succession; the effectiveness of three metrics (diversity, evenness and richness) as indicators of patch variability; and how thematic resolution can affect the perception of environme...

British Library Electronic Table of Contents (United Kingdom)

Climate variability greatly affects animals through direct and indirect effects. Animals with slow reproductive adaptation to ecological changes such as large mammals are likely to have evolved mechanisms to anticipate early such impacts of climate variability on the environment. One of the adaptive mechanisms between reproductive costs and benefits in mammals affects parental investment through biases in sex ratio. Deer might be likely to show an early detection of climate variability because conception takes place in early autumn, but the main raising cost in deer concerns lactation, which takes place at the end of the following spring. The aim of this paper is to assess whether there is a relationship between global indices of climate variability such as El Ni?o-Southern Oscillation (EN...

UK PubMed Central (United Kingdom)

The study of genetic variability within natural populations of pathogens may provide insight into their evolution and pathogenesis. We used a Mycobacterium tuberculosis high-density...Full Text Available

Science.gov (United States)

measure meteorological variables and bulk water temper- ature. The locations of the buoys are given in Table 1. TB2 and TB3 were moved slightly farther south ...

Science.gov (United States)

... Direct Search (SMOMADS) and Paciencia's NMADS [45] based on Kim and de Weck's ... Todd Paciencia for his foundational contributions. ...

Energy Technology Data Exchange (ETDEWEB)

Thermal and mechanical properties for geothermal formations are tabulated for a range of temperatures and stress conditions. Data was obtained from the technical literature and direct contacts with industry. Thermal properties include heat capacity, conductivity, and diffusivity. Undisturbed geothermal profiles are also presented. Mechanical properties include Youngs modulus and Poisson ratio. GEOTEMP thermal simulations of drilling, production and injection are reported for two geothermal regions, the hot dry rock area near Los Alamos and the East Mesa field in the Imperial Valley. Actual drilling, production, and injection histories are simulated. Results are documented in the form of printed GEOTEMP output and plots of temperatures versus depth, radius, and time. Discussion and interpretation of the results are presented for drilling and well completion design to determine: wellbore temperatures during drilling as a function of depth; bit temperatures over the ...

International Nuclear Information System (INIS)

Praseodymium-doped Bi_4Ti_3O_1_2 (BIT) with various compositions of dopant, Pr (x = 0.5, 0.6, 0.7, 0.8) in Bi_4_-_xPr_xTi_3O_1_2 (BPT) were synthesized using a low temperature wet chemical technique. Powders calcined at 800 deg. C exhibit a single phase polycrystalline perovskite bismuth-layered structure. Randomly oriented plate-like structures were observed under Scanning Electron Microscope (SEM). A small amount of Pr doping (x = 0.5) resulted in dramatically reduced of grain size from 2 #mu#m to less than 50 nm in which Pr plays the role as a grain growth inhibitor. However, by increasing the composition of Pr, bigger grain size of up to 1 #mu#m was observed for x = 0.8 that was caused by diffusion of Pr in the perovskite structure. Dielectric properties showed that dielectric permittivity decreased with the addition of x = 0.50, and increasing with further addition of Pr. Dissipation factor (tan #delta#) followed the same trend as dielectric constant that was ...

Science.gov (United States)

PLZT-7/65/35 is a ferroelectric ceramic with strong electrooptic properties and memory; it is switched through transparent electrodes when mechanically strained. Matrix addressed x-y page composers for interfacing electrical and coherent optical systems are being fabricated with PLZT. Switching voltages are 50-300 V. Optical efficiencies greater than 40% have been achieved. Strains near 2.4 x 10(-3) mm/mm permit half-wave retardation switching in 100-micro-thick plates with 80-V read-in and 190-V erase levels (60 Hz hysteresis data). A 128 x 128 element array can operate at 10(7) bits/sec with 10-microsec switching in a row at a time mode. Half-select disturbances affect contrasts. Applications in displays are also feasible. PMID:20111514

CERN Document Server

In this paper we develop a general, systematic, microlocal framework for the Fredholm analysis of non-elliptic problems, including high energy (or semiclassical) estimates, which is stable under perturbations. This framework is relatively simple given modern microlocal analysis, and only takes a bit over a dozen pages after the statement of notation. It resides on a compact manifold without boundary, hence in the standard setting of microlocal analysis, including semiclassical analysis. The rest of the paper is devoted to applications. Many natural applications arise in the setting of non-Riemannian b-metrics in the context of Melrose's b-structures. These include asymptotically Minkowski metrics, asymptotically de Sitter-type metrics on a blow-up of the natural compactification and Kerr-de Sitter-type metrics. The simplest application, however, is to provide a new approach to analysis on Riemannian or Lorentzian (or indeed, possibly of other signature) conformally ...

Energy Technology Data Exchange (ETDEWEB)

The northeastern part of the Great Divide basin is a separate, unique, and until recently, little-explored subbasin sometimes called the Bison basin. It is bounded by the Wind River Mountains, Sweetwater-Granite Mountain foreland uplift, Lost Soldier-Wertz structure, and a little-studied very positive east-west structural arch approximately coincident with the Sweetwater-Fremont county line. A comprehensive seismic, Landsat, and subsurface geologic examination or, better, dissection of the Bison basin was initiated in 1978. Numerous oil and gas prospects were delineated by this study. Since this small, 12 by 40 mi (19 by 64 km) basin is bordered by known reserves of 260 million bbl of oil and 90 million bcf of gas, these prospects proved to be a popular target of the drill bit. At least one of these prospects appears to be productive; others are currently being drilled. The presence of major east-west wrench faults, a well-documented foreland uplift, until recently ...

Energy Technology Data Exchange (ETDEWEB)

Various main circuit equipment with large capacity GTO thyristors are outlined for AC and DC electric cars. The configuration of a PWM converter system is presented for the AC main motor drive system of the Shinkansen trains, and its following features are described: the high power factor control capable of keeping a power factor 100% constantly, energy saving by power regenerative braking, the small triple structure with large capacity reverse-conducting GTO thyristors of 4,500V/3,000A, and the reduction of equivalent interfering current and harmonic current by three phase-triple phase difference operation. Furthermore, a control logic equipment with 16 bit MPU and a main transformer are outlined, and the verification test results of the control logic equipment by an analog model simulation and the combinational test results of the commercial equipment are reported. Prototype VVVF inverter system for DC electric cars is also presented. 6 refs., 13 figs., 3 tabs.

International Nuclear Information System (INIS)

A physical model of free-electron laser (FEL) amplifier with variable-parameter wiggler magnets for one-dimensional numerical simulation is presented and a numerical example is given. The wiggler parameters, efficiency of energy conversion between electron beam and laser field, laser intensity, phase-space distributions and energy spectrum of electrons are computed. The period of synchronous oscillation and saturation value of laser intensity agree with estimated one.

Energy Technology Data Exchange (ETDEWEB)

This book contains the Proceedings of the Conference on Climate and Water under the following groupings: Impacts of climatic variability and change-resulting from the changes in hydrological variables; Aquatic environment; Terrestrial environment; Coastal zones and navigation; Urban and industrial water supply and drainage; Energy production; Intropogenic changes of climate and water management problems; Flood potential; Irrigation and land drainage.

Energy Technology Data Exchange (ETDEWEB)

Two major developments have given impetus to wider adoption of variable-speed turbine/generators in hydroelectric plants, both essentially environmental: (1) the need for stream-bed stability below river dams, and (2) the need to minimize fish damage. Also, the need to stabilize pumped-storage and generating efficiencies to match extreme changes in head levels has been a driving force. Variable-speed operation in hydro applications is relatively new to North America. In other parts of the world, it has been used in pumped-storage plants since 1971. In the US, and increasing potential exists for variable-speed hydro, considering the 30 pumped-storage plants already in operation and several river plants struggling with high head fluctuations--including four at stations operated by the Bonneville Power Administration. Several modifications to hydro-plant hardware and operating procedures are actively being considered at ...

International Nuclear Information System (INIS)

The effect of fetal distress on the neonatal brain was investigated by neonatal CT brain scan, FHR monitoring and mode of delivery. This study involved 11 cases of full term vertex delivery in which FHR was recorded by fetal direct ECG during the second stage labor. All infants weighed 2,500 g or more. FHR monitoring was evaluated by Hon's classification. Neonatal brain edema was evaluated by cranial CT histgraphic analysis (Nakada's method). 1) Subdural hemorrhage was noted in 6 of 7 infants delivered by vacuum extraction or fundal pressure (Kristeller's method). 2) Intracranial hemorrhage was demonstrated in all of 3 infants with 5-min. Apgar score 7 or less. 3) Two cases with prolonged bradycardia and no variability had intraventricular or intracerebral hemorrhage which resulted in severe central nervous system damage. 4) The degree of neonatal brain edema correlated with 5-min. Apgar score. 5) One case with prolonged bradycardia and no ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Abstract Anesthetics affect outcomes from central nervous system (CNS) injuries differently. This is the first study to show how two commonly used anesthetics affect continuously recorded hemodynamic parameters and locomotor recovery during a 2-week period after two levels of contusion spinal cord injury (SCI) in rats. We hypothesized that the level of cardiovascular depression and recovery of locomotor function would be dependent upon the anesthetic used during SCI. Thirty-two adult female rats were subjected to a sham, 25-mm or 50-mm SCI at T3-4 under pentobarbital or isoflurane anesthesia. Mean arterial pressure (MAP) and heart rate (HR) were telemetrically recorded before, during, and after SCI. Locomotor function recovered best in the 25-mm-injured isoflurane-anesthetized animals. There was no significant difference in locomotor recovery between the 25-mm-injured pentobarbital-anesthetized animals and the 50-mm-injured isoflurane-anesthetized animals. White ...

Energy Technology Data Exchange (ETDEWEB)

This interim technical report presented a summary of results obtained from Pit Lake models developed from different simulation models. The models were used to predict stratification in a hypothetical Pit Lake. Predictions were used to assess the hydrodynamic similarities and differences between the 2 models and to determine if the models would produce similar stratification profiles for the Pit Lakes to previous models. Results showed that the models produced similar results for both temperatures and salinities. The main difference between the RMA10 and CE-QUAL-W2 model used in a previous study was found to be run time. A sensitivity analysis of the RMA10 and CE-QUAL-W2 model predictions was completed to assess the effects of segmentation; time step; lake surface area; lake orientation; and model coefficients or parameters. Results showed that the selected time step and model segmentation were appropriate, as both led to modelling results that were stable. However, while the CE-QUAL-W2 ...

Energy Technology Data Exchange (ETDEWEB)

The data center in this study had a total floor area of 3,024 square feet (ft{sup 2}) with one-foot raised-floors. It was a rack lab with 147 racks, and was located in a 96,000 ft{sup 2} multi-story office building in San Jose, California. Since the data center was used only for testing equipment, it was not configured as a critical facility in terms of electrical and cooling supply. It did not have a dedicated chiller system but was served by the main building chiller plant and make-up air system. Additionally it was served by only a single electrical supply with no provision for backup power in the event of a power outage. The Data Center operated on a 24 hour per day, year-round cycle, and users had full-hour access to the data center facility. The study found that data center computer load accounted for 15% of the overall building electrical load, while the total power consumption attributable to the data center including allocated cooling load and lighting was 22% of the total ...

Energy Technology Data Exchange (ETDEWEB)

A remarkably simple argument successfully accounts for the rate of star formation in different galaxies. The snag is that the timescale is uncomfortably short.

Energy Technology Data Exchange (ETDEWEB)

To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and ...

British Library Electronic Table of Contents (United Kingdom)

In this article, we studied the effects of variable viscosity and thermal conductivity on an unsteady two-dimensional laminar flow of a viscous incompressible conducting fluid past a semi-infinite vertical porous moving plate taking into account the effect of a magnetic field in the presence of variable suction. The fluid viscosity is assumed to vary as an inverse linear function of temperature but the thermal conductivity is assumed to vary as a linear function of temperature. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The governing equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation ...

Energy Technology Data Exchange (ETDEWEB)

An automotive powertrain includes a conventional piston engine, a continuously variable ratio transmission, an engine speed sensor and a feedback control system. The control system adjusts both the transmission ratio and the throttle valve in the engine carburetor or fuel metering system in response to the position of the accelerator pedal and in response to the crankshaft speed as measured by the engine sensor. The transmission provides extreme overdrive gear ratios which allow the engine to be operated at wide open throttle even during moderate cruising, and, in addition, the engine carburetor or fuel metering system is calibrated to deliver to the engine a stoichiometric air-fuel mixture which is combined, before combustion, with a special proportion of recirculated exhaust gas. As a result of extensive wide open throttle engine operation with the above mentioned intake charge composition, combustion variables are optimized to produce ...

British Library Electronic Table of Contents (United Kingdom)

This paper analyses Italian interregional migration flows. The approach taken is to decompose labour mobility flows into short distance and long distance migration and to model the effects of economic variables, social capital and quality of life variables, and amenity variables, on the mobility behaviour of individuals. We estimate these different types of migration flows using a negative binomial model, augmented with instruments to control for potential endogeneity issues. Our findings demonstrate that long distance migration reflects a disequilibrium model of migration whereas short distance migration largely reflects an equilibrium model of migration. As such, attempts to model interregional migration in general will be mis-specified as the simultaneously-operating underlying mobility...

British Library Electronic Table of Contents (United Kingdom)

Various SST indices in the Indo-Pacific region have been proposed in the literature in light of a long-range seasonal forecasting of the Indian Summer Monsoon (ISM). However, the dynamics associated with these different indices have never been compared in detail. To this end, the present work re-examines the variabilities of ISM rainfall, onset and withdrawal dates at interannual timescales and explores their relationships with El Ni?o-Southern Oscillation (ENSO) and various modes of coupled variability in the Indian Ocean. Based on recent findings in the literature, five SST indices are considered here: Ni?o3.4 SST index in December?January both preceding [Nino(?1)] and following the ISM [Nino(0)], South East Indian Ocean (SEIO) SST in February?March, the Indian Ocean Basin (IOB) mode in ...

CERN Document Server

An interesting line of research is the investigation of the laws of random variables known as Dirichlet means. However, there is not much information on interrelationships between different Dirichlet means. Here, we introduce two distributional operations, one of which consists of multiplying a mean functional by an independent beta random variable, the other being an operation involving an exponential change of measure. These operations identify relationships between different means and their densities. This allows one to use the often considerable analytic work on obtaining results for one Dirichlet mean to obtain results for an entire family of otherwise seemingly unrelated Dirichlet means. Additionally, it allows one to obtain explicit densities for the related class of random variables that have generalized gamma convolution distributions and the finite-dimensional distribution of their associated L\\'{e}vy processes. ...

CERN Document Server

The central engine of Gamma Ray Bursts is hidden from direct probing with photons mainly due to the high densities involved. Inferences on their properties are thus made from their cosmological setting, energetics, low-energy counterparts and variability. If GRBs are powered by hypercritical accretion onto compact objects, on small spatial scales the flow will exhibit fluctuations, which could in principle be reflected in the power output of the central engine and ultimately in the high energy prompt emission. Here we address this issue by characterizing the variability in neutrino cooled accretion flows through local shearing box simulations with magnetic fields, and then convolving them on a global scale with large scale dynamical simulations of accretion disks. The resulting signature is characteristic, and sensitive to the details of the cooling mechanism, providing in principle a discriminant for GRB central engine properties.

British Library Electronic Table of Contents (United Kingdom)

This paper presents a study on Manasbal lake, which is one of the high altitude lakes in the Kashmir Valley, India. Eighteen water samples were analysed for major ions and trace elements to assess the variability of water quality of the lake for various purposes. Geostatistics, the theory of regionalized variables, was then used to enhance the dataset and estimate some missing spatial values. Results indicated that the concentration of major ions in the water samples in winter was higher than in summer. The scatter diagrams suggested the dominance of alkaline earths over the alkali elements. Three types of water were identified in the lake that are referred to as Ca?HCO3, Mg?HCO3 and hybrid types. The lake water was found to be controlled by rock?water interaction with carbonate lithology ...

International Nuclear Information System (INIS)

A variable gene delivery system has been developed based on conjugating chitosan to biotin through a functionalized poly(ethylene glycol) (PEG) spacer, which can be used to further bind different molecules on the outer layer of a polymer/DNA complex by streptavidin (SA)-biotin linkage. In this study, TAT-conjugated SA was used as the model molecule to prove the conjugation function of the prepared complex. In addition, low-molecular-weight poly(ethyleneimine) (PEI) was added into the polymer/DNA complex to increase the transfection efficiency. The results of the luciferase assay show that the transfection efficiency of the prepared complex was significantly correlated with the amount of PEI and was further enhanced when TAT was conjugated to the complex by SA-biotin linkage. Considered to have negligible cytotoxic effects, the variable gene delivery complex prepared in this study would be of considerable potential as carriers for in vitro ...

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We analyzed the effect of short-term water deficits at different periods of sunflower (Helianthus annuus L.) leaf development on the spatial and temporal patterns of tissue expansion...Full Text Available

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BackgroundTransposons, i.e. transposable elements (TEs), are the major internal spontaneous mutation agents for the variability of eukaryotic genomes. To address the general issue...Full Text Available

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Activation-induced deaminase (AID) initiates somatic hypermutation, gene conversion and class switch recombination by deaminating variable and switch region DNA cytidines to uridines. AID is predominantly...Full Text Available

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A previous report of high levels of members of the domain Archaea in Antarctic coastal waters prompted us to investigate the ecology of Antarctic planktonic prokaryotes. rRNA hybridization...Full Text Available

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Dependent variables in research on problem behavior typically are based on measures of response repetition, but these measures may be problematic when behavior poses high risk or when its occurrence...Full Text Available

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Dissecting the genes involved in complex traits can be confounded by multiple factors, including extensive epistatic interactions among genes, the involvement of epigenetic regulators, and the variable...Full Text Available

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Using the POLISH instrument, I am unable to reproduce the large-amplitude polarimetric observations of Berdyugina et al. (2008) to the >99.99% confidence level. I observe no significant polarimetric variability in the HD 189733 system, and the upper limit to variability from the exoplanet is Delta_P < 7.9 x 10^(-5) with 99% confidence in the 400 nm to 675 nm wavelength range. Berdyugina et al. (2008) report polarized, scattered light from the atmosphere of the HD 189733b hot Jupiter with an amplitude of two parts in 10^4. Such a large amplitude is over an order of magnitude larger than expected given a geometric albedo similar to other hot Jupiters. However, my non-detection of polarimetric variability phase-locked to the orbital period of the exoplanet, and the lack of any significant variability, shows that the polarimetric modulation reported by Berdyugina et al. (2008) cannot be due to the ...

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The sequence-dependent structural variability and conformational dynamics of DNA play pivotal roles in many biological milieus, such as in the site-specific binding of transcription factors to target...Full Text Available

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Despite the demonstrated clinical efficacy of CD20 monoclonal antibody (mAb) for lymphoma therapy, the in vivo mechanisms of tumor depletion remain controversial and variable. To identify the molecular...Full Text Available

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Simulations with a regional chemical transport model show that anthropogenic emissions of volatile organic compounds and nitrogen oxides (NO_x = NO + NO₂) lead to a dramatic diurnal...Full Text Available

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Random forest (RF) analysis of genetic data does not require specification of the mode of inheritance, and provides measures of variable importance that incorporate interaction effects. In this paper...Full Text Available

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In this review we attempt to reconstruct the evolutionary history of hominin life history from extant and fossil evidence. We utilize demographic life history theory and distinguish life history variables,...Full Text Available

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High speed experimental tests provided data on six parametric cylindrical roller bearings. Four bearing variables were evaluated and the results were correlated with the analytical model developed under Naval Air Propulsion Center Contract N00140-76-C-038...

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The systems for which the algebra of gauge transformations in the lagrangian formalism is closed, are considered. The hamiltonian BRST charge and the BRST-invariant hamiltonian are found explicitly. Their expansions in powers of the ghost variables contain, in general, an infinite number of terms. (orig.).

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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

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Exercise is essential for health, yet the amount, duration, and intensity that individuals engage in are strikingly variable, even under prescription. Our focus was to identify the locations and effects...Full Text Available

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The aim of the present study focuses on experimentally demonstrating the efficacy of using angularly-variable fiber geometry to achieve the desired tissue-layer selection and probing depths with the further objective of enhancing the sensitivity and specificity of spectral diagnosis in stratified architectures that resemble human cervical epithelia. The morphological and biochemical features of epithelial tissue vary in accordance with tissue depths; consequently, the accuracy of spectroscopic diagnosis of epithelial dysplasia may be enhanced by probing the optical properties of this tissue. When correlated to cellular dysplasia, layer-specific changes in tissue optical properties may be deciphered by reflectance spectroscopy coupled with angularly-variable fiber geometry. This study addresses the utility of using such angularly-variable fiber geometry for resolving spatially-specific spectral signatures of tissue ...

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... 1984; Martin-Mora et al., 1995), and parasitism (Rothschild and Rothschild, 1939; Pesigan et al., 1958; Moose, 1963; Pan, ... effects of digeneans are variable; they may enhance (Rothschild and Rothschild...

International Nuclear Information System (INIS)

Energy confinement in W7-AS has been analyzed in terms of dimensionally exact form free functions employing Bayesian probability theory. The confinement function was set up as a linear combination of dimensionally exact power law terms as already proposed very early by Connor and Taylor. Generation of this expansion basis is dictated by the basic plasma model which one assumes. Based upon data accumulated in W7-AS, which contains the energy content for a wide variety of variable settings, predictions for single variable scans are made. The scaling functions for density and power scans, respectively, are in quantitative agreement with data collected in W7-AS. The result of a single variable scan is therefore already hidden in the data obtained for arbitrary variable choices and can be extracted from the latter by a proper data analysis. Furthermore, the optimal model for the description of the global ...

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

Energy Technology Data Exchange (ETDEWEB)

In recent years the modelling of interannual climate variability has been studied, the atmospheric energy and water cycles, and climate simulations with the ECHAM3 model. In addition, the climate simulations of several models have been compared with special emphasis in the area of northern Europe

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In this report, the main emphasis is given to (1) the problems associated with the basic calibration of the spectroradiometer and (2) the year-to-year variability of the calibrations of the solar UV network radiometers. Also, the results from intercomparisons of the Brewer and OL 742 spectroradiometers are included

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An elliptic equation in a rectangle with coefficients depending on a fast variable and with its period being a small parameter is considered. An asymptotic expansion of the solution up to an arbitrary degree of the small parameter is constructed and substantiated by applying the two-scale expansion method.

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Visual assessment of the degree of renal artery stenosis on renal arteriography has a large inter- and intraobserver variability. This degree is usually estimated by the ratio between the most narrowed...Full Text Available

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Antiplatelet resistance has been proposed as a possible mechanism to explain recurrent cardiovascular events in patients who have coronary artery disease and who are undergoing dual antiplatelet therapy....Full Text Available

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BackgroundTraditionally in pediatric HIV, the CD4+ T-lymphocyte percent is used in monitoring disease progression due to the variability in absolute CD4+ T-lymphocyte...Full Text Available

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PurposeTo detail the highly variable ocular phenotypes of a French family affected with an autosomal dominantly inherited vitreoretinopathy and to identify the disease gene.MethodsSixteen...Full Text Available

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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

International Nuclear Information System (INIS)

A variable-dispersion electron spectrometer is being installed for use by the Stanford Superconducting Accelerator in conjunction with its Free Electron Laser program. The system has been designed to operate with electron beam energies from 20 MeV to 200 MeV, with a maximum energy resolution of 0.01% FWHM. The maximum energy acceptance is approximately #+-# 5%, as determined by the bending magnet aperture. Resolution is controlled by adjusting the focal conditions at the entrance to a 90 degree bending magnet, while the dispersion is controlled by changing the magnitude and polarity of the field in a quadrupole magnet which immediately follows the bending magnet. 4 refs., 5 figs.

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Divergence between aircraft engine emission regulations proposed by EPA and ICAO is discussed. Every engine, upon entering service, requires a certificate as to its compliance with emission standards. It is shown that despite the large variability in the measurements, it is possible to devise a certification procedure requiring the testing of one engine only. Statistical modeling of such a test at the 5% significance level is described. Values of the parameter standard deviation/mean recommended as certification standards for various pollutants are given. Features of a rational certification scheme to be formulated are outlined.

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For reliable operation and the optimization of production, industrial fermentation processes require appropriate tools for monitoring the process in real time. This work presents the structure and operation of a soft sensor for the on-line monitoring of biomass and product concentration during salinomycin and bacitracin fermentation in an industrial, 80-m^3 batch reactor; moreover it provides a tool for evaluation of batch production verified in industrial application. The process estimation algorithm consists of decoupled growth and product models, which ensures an unbiased convergence of the estimator and the robustness of the model. The production of secondary metabolites is described with a non-structured model upgraded with a variable forgetting factor that demonstrated a successful e...

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The marine ram-type blowout preventer deployed from an offshore drilling rig has one serious disadvantage, its inaccessibility. A development to promote reliability of the subsea ram-type preventer and reduce the excess running and pulling to charge out rams, is the variable bare ram (VBR). Unlike the standard ram, the VBR has the ability to pack off a range of pipe sizes. Interest in VBR's has been revived and research and development in this equipment goes on at each of three manufacturer's facilities in Houston.

International Nuclear Information System (INIS)

We consider the spin-up of the white dwarf in non-magnetic cataclysmic variables (CVs) during secular evolution. If this is unresisted, CVs are quenched as boundary-layer emitters once the binary period has decreased by #approx# 1 hr. Angular momentum loss in nova explosions may, however, prevent the star reaching breakup. If the explosions remove (1 + #epsilon#) x the mass accreted between outbursts, values 0.5 < #approx# #epsilon# < #approx# 1 allow CVs to be modest boundary-layer emitters for most of their lifetimes. Spectral effects will limit their detection as soft X-ray sources. (author).

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The effects of variable hardness, pH, alkalinity, humics, and suspended clay on the chemical speciation of copper and its toxicity to fathead minnow larvae in Lake Superior water were investigated. Two proposed methods (toxicity factors and chemical speciation) for predicting LC50 values in specific natural waters from laboratory toxicity data and the average site specific values of general water quality parameters were evaluated. The accuracy of the cupric ion-selective electrode in determining CU/sup +2/ activities in ambient and chemically altered Lake Superior water was also determined.

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In this project we determined primary production and optical variability in the shelf and slope waters off of Cape Hatteras, N.C. These processes were addressed in conjunction with other Ocean Margins Program investigators, during the Spring Transition period and during Summer. We found that there were significant differences in measured parameters between Spring and Summer, enabling us to develop seasonally specific carbon production and ecosystem models as well as seasonal and regional algorithm improvements for use in remote sensing applications.

Energy Technology Data Exchange (ETDEWEB)

A reliability approach for probabilistic modeling of one-dimensional non-reactive and reactive transport in porous media provides two important quantitative results: (1) an estimate of the probability that dimensionless concentration equals or exceeds some specified level and, (2) the sensitivity of the probabilistic outcome to likely changes in each uncertain variable. The reliability approach is particularly attractive because it can incorporate various marginal probability density functions (PDF) for any of the uncertain variables. In this work uncertain variables include: groundwater flow velocity, diffusion coefficient, dispersivity, distribution coefficient, porosity and bulk density. The primary objective is to examine how the probabilistic outcome is influenced by choice of marginal PDF, correlation and magnitude of uncertainty for the variables. Because little information exists concerning the ...

UK PubMed Central (United Kingdom)

A new analysis is presented which links real volume fractions, relaxation rates, and intracompartmental exchange rates directly with apparent volume fractions and relaxation rates obtained from biexponential...Full Text Available