WorldWideScience
1

Generalized quantum theory of recollapsing homogeneous cosmologies  

International Nuclear Information System (INIS)

A sum-over-histories generalized quantum theory is developed for homogeneous minisuperspace type A Bianchi cosmological models, focusing on the particular example of the classically recollapsing Bianchi type-IX universe. The decoherence functional for such universes is exhibited. We show how the probabilities of decoherent sets of alternative, coarse-grained histories of these model universes can be calculated. We consider in particular the probabilities for classical evolution defined by a suitable coarse graining. For a restricted class of initial conditions and coarse grainings we exhibit the approximate decoherence of alternative histories in which the universe behaves classically and those in which it does not. For these situations we show that the probability is near unity for the universe to recontract classically if it expands classically. We also determine the relative probabilities of quasiclassical trajectories for initial states of ...

2004-06-15

2

Beam stability study based on the beam trajectory jitter in the KEKB injector linac  

International Nuclear Information System (INIS)

... Tsukuba, Ibaraki (Japan) 389 p. PARTICLE ACCELERATORS beam monitoring

2001-08-01

3

Naltrexone and Combined Behavioral Intervention Effects on Trajectories of Drinking in the COMBINE study  

UK PubMed Central (United Kingdom)

ObjectiveCOMBINE is the largest study of pharmacotherapy for alcoholism in the United States to date, designed to answer questions about the benefits of combining...Full Text Available

2010-03-01

4

Delineation of the Middle Longitudinal Fascicle in Humans: A Quantitative, In Vivo, DT-MRI Study  

UK PubMed Central (United Kingdom)

Experimental and imaging studies in monkeys have outlined various long association fiber bundles within the temporoparietal region. In the present study the trajectory of the middle longitudinal fascicle...Full Text Available

2009-04-01

5

Evolutionary Trajectories of Beta-Lactamase CTX-M-1 Cluster Enzymes: Predicting Antibiotic Resistance  

UK PubMed Central (United Kingdom)

Extended-spectrum beta-lactamases (ESBL) constitute a key antibiotic-resistance mechanism affecting Gram-negative bacteria, and also an excellent model for studying evolution in real time. A shift in...Full Text Available

2010-01-01

6

Numerical prediction of flow field and particle trajectory in a hard disk drive  

Energy Technology Data Exchange (ETDEWEB)

A flow field and particle trajectory in a HDD (Hard Disk Drive) between two rotating disks in axisymmetric enclosures is investigated using CFD code FLUENT/UNS. The RNG k-{epsilon} model is used as a turbulent model. In this study, the flow field between two disks are symmetric, and the flow field near the enclosure is very complex. Cross stream vectors are shown both for blowing and no blowing from the hub. The larger a particle, the more fast the particle deposits at the walls. In the case of blowing from the hub, the more fast the particle deposits at the walls. (author). 9 refs., 12 figs., 1 tab.

1999-11-01

9

Use of the parmbsc0 force field and trajectory analysis to study the binding of netropsin to the DNA fragment (5'CCAATTGG)2 in the presence of excess NaCl salt in aqueous solution  

British Library Electronic Table of Contents (United Kingdom)

The parmbsc0 force field was applied to study in detail the binding of netropsin, at a salt concentration of 0.28M Na^+, to the minor groove of an 8-mer (5'CCAATTGG)2 DNA duplex forming a netropsin.DNA complex which previously has been characterized by X-ray crystallography, albeit with the use of closely related DNA duplexes. The X-ray structure revealed that the terminal guanidinium and amidinium groups of netropsin interact with the extreme ends of the palindromic AATT sequence of the receptor DNA. The parmbsc0 parameters of B-DNA and AMBER v9 parameters of netropsin generated a stable 6ns molecular dynamics (MD) trajectory for a 1:1 class I binding motif of this complex. Trajectory analysis for the salt and hydration effects on the binding of netropsin to the 8-mer DNA duplex revealed ...

2011-01-01

10

The optimal path of piston motion for Otto cycle with linear phenomenological heat transfer law  

British Library Electronic Table of Contents (United Kingdom)

An Otto cycle engine with internal and external irreversibilities of friction and heat leakage, in which the heat transfer between the working fluid and the environment obeys linear phenomenological heat transfer law [q ?? ?(T ?1)], is studied in this paper. The optimal piston motion trajectory for maximizing the work output per cycle is derived for the fixed total cycle time and fuel consumed per cycle. Optimal control theory is applied to determine the optimal piston trajectories for the cases of with and without piston acceleration constraint on each stroke and the optimal distribution of the total cycle time among the strokes. The optimal piston motion with acceleration constraint for each stroke consists of three segments, including initial maximum acceleration and final maximum decel...

2009-01-01

11

The high-density regime of kinetic-dominated loop quantum cosmology  

CERN Document Server

We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These moments back-react on the trajectories of the expectation values of the state and hence alter the energy density at the bounce. This analysis is performed for isotropic loop quantum cosmology coupled to a scalar field with a small but non-zero constant potential, hence in a regime in which the kinetic energy of matter dominates. Analytic restrictions on the existence of dynamical coherent states and the meaning of semi-classicality within these systems are discussed. A numerical investigation of the trajectories of states that remain semi-classical across the bounce demonstrates that, at least for such states, the bounce persists and that its properties are similar to the standard case, ...

2010-01-01

12

Relativistic D-brane scattering is extremely inelastic  

Energy Technology Data Exchange (ETDEWEB)

We study the effects of quantum production of open strings on the relativistic scattering of D-branes. We find strong corrections to the brane trajectory from copious production of highly-excited open strings, whose typical oscillator level is proportional to the square of the rapidity. In the corrected trajectory, the branes rapidly coincide and remain trapped in a configuration with enhanced symmetry. This is a purely stringy effect which makes relativistic brane collisions exceptionally inelastic. We trace this effect to velocity-dependent corrections to the open string mass, which render open strings between relativistic D-branes surprisingly light. We observe that pair-creation of open strings could play an important role in cosmological scenarios in which branes approach each other at very high speeds. (author)

2005-02-01

13

Nonlinear dynamic analysis of a hybrid squeeze-film damper-mounted rigid rotor lubricated with couple stress fluid and active control  

British Library Electronic Table of Contents (United Kingdom)

The hybrid squeeze-film damper bearing with active control is proposed in this paper and the lubricating with couple stress fluid is also taken into consideration. The pressure distribution and the dynamics of a rigid rotor supported by such bearing are studied. A PD (proportional-plus-derivative) controller is used to stabilize the rotor-bearing system. Numerical results show that, due to the nonlinear factors of oil film force, the trajectory of the rotor demonstrates a complex dynamics with rotational speed ratio s. Poincare maps, bifurcation diagrams, and power spectra are used to analyze the behavior of the rotor trajectory in the horizontal and vertical directions under different operating conditions. The maximum Lyapunov exponent and fractal dimension concepts are used to determine ...

2010-01-01

14

Existence of a complex closed trajectory in a three-dimensional dynamical system  

British Library Electronic Table of Contents (United Kingdom)

The DN-tracking method is used to prove the existence of a closed trajectory in a quadratic system of ordinary differential equations in three dimensions.

2011-01-01

15

The interaction of fast N"+_2 ions with a Ni(111) surface  

International Nuclear Information System (INIS)

In the context of sputtering experiments, studying the back-scattering of fast ion beams is a useful way to study inelastic ion-surface interactions, since then the trajectories and energies of the particles are well defined. This same argument holds for the scattering of fast molecular ions. We give a short account of our experiment where N"+_2 was scattered from a Ni(111) surface. The measured energy distributions of scattered N atoms are discussed with regard to vibrational and rotational energy transfer during scattering. (G.Q.).

1986-02-01

17

On the optimal taxation of common-pool resources  

British Library Electronic Table of Contents (United Kingdom)

Recent research developments in common-pool resource models emphasize the importance of links with ecological systems and the presence of non-linearities, thresholds and multiple steady states. In a recent paper Kossioris et al. (2008) develop a methodology for deriving feedback Nash equilibria for non-linear differential games and apply this methodology to a common-pool resource model of a lake where pollution corresponds to benefits and at the same time affects the ecosystem services. This paper studies the structure of optimal state-dependent taxes that steer the combined economic-ecological system towards the trajectory of optimal management, and provides an algorithm for calculating such taxes.

2011-01-01

18

Meteorological and air quality impacts of increased urban albedo and vegetative cover in the Greater Toronto Area, Canada  

Energy Technology Data Exchange (ETDEWEB)

The study described in this report is part of a project sponsored by the Toronto Atmospheric Fund, performed at the Lawrence Berkeley National Laboratory, to assess the potential role of surface property modifications on energy, meteorology, and air quality in the Greater Toronto Area (GTA), Canada. Numerical models were used to establish the possible meteorological and ozone air-quality impacts of increased urban albedo and vegetative fraction, i.e., ''cool-city'' strategies that can mitigate the urban heat island (UHI), significantly reduce urban energy consumption, and improve thermal comfort, particularly during periods of hot weather in summer. Mitigation is even more important during critical heat wave periods with possible increased heat-related hospitalization and mortality. The evidence suggests that on an annual basis cool-city strategies are beneficial, and the implementation of such measures is currently being ...

2002-04-30

19

Invertebrates and the Restoration of a Forest Ecosystem: 30 Years of Research following Bauxite Mining in Western Australia  

British Library Electronic Table of Contents (United Kingdom)

Abstract Restoration needs to consider more than just soils and plants. The role of terrestrial invertebrates in the restoration of Alcoa's bauxite mines in the Jarrah (Eucalyptus marginata) forest of Western Australia has been the subject of over 20 individual studies. Projects range from arthropods in soil and leaf litter, to the understorey vegetation, and the tree canopy. Moreover, projects span a range of trophic groups, including decomposers (e.g., springtails and termites), predators (e.g., ants and spiders), and herbivores (e.g., true bugs and ants preying on seeds). Elucidation of recolonization trajectories uses both space-for-time substitutions and long-term regular sampling. Importantly, many studies are at species level rather than coarser taxonomic ranks. This paper provides ...

2007-01-01

20

Semiclassical calculation of photon-stimulated Schwinger pair creation  

International Nuclear Information System (INIS)

We consider the electron-positron pair creation by a photon in an external constant electric field. The presented treatment is based on a purely quasiclassical calculation of the imaginary part of the on-shell photon polarization operator. By using this approach we find the pair production rate for photons with polarization parallel as well as orthogonal to the external electric field in the leading order in the parameter eE/m"2, which has been recently found by other methods. For the orthogonal polarization we also find a new contribution to the rate, which is leading in the ratio of the photon energy to the electron mass #omega#/m. We also reproduce by a purely geometrical calculation the exponential factor in the probability of the stimulated pair creation at arbitrary energy of the photon.

2010-04-15

21

Nuclear fission with mean-field instantons  

CERN Document Server

We present a description of nuclear spontaneous fission, and generally of quantum tunneling, in terms of instantons - periodic imaginary-time solutions to time-dependent mean-field equations - that allows for a comparison with more familiar and used generator coordinate (GCM) and adiabatic time-dependent Hartree-Fock (ATDHF) methods. It is shown that the action functional whose value for the instanton is the quasiclassical estimate of the decay exponent fulfils the minimum principle when additional constraints are imposed on trial fission paths. In analogy with mechanics, these are conditions of energy conservation and the velocity-momentum relations. In the adiabatic limit the instanton method reduces to the time-odd ATDHF equation, with collective mass including the time-odd Thouless-Valatin term, while the GCM mass completely ignores velocity-momentum relations. This implies that GCM inertia generally overestimates instanton-related decay rate. The very ...

2007-01-01

22

Magnetic-field-induced phase transitions in Wigner molecules  

Energy Technology Data Exchange (ETDEWEB)

A theoretical analysis of formation and symmetry transformations is presented for Wigner molecules with N = 2,..., 20 electrons confined in quantum dots at high magnetic fields. Using the unrestricted Hartree-Fock method with the multicentre Gaussian basis, we have found that Wigner molecules with N {>=} 6 abruptly change their shape and symmetry with an associated jump in the first derivative of the ground-state energy, i.e. they undergo phase transitions. In particular, the phases of the Wigner molecules obtained just after emerging from the maximum-density droplet (MDD) phase possess a different symmetry from that formed at a high magnetic field. We show that the properties of the electron-electron interaction energy demonstrate very well both the breakdown of the MDD and the quasi-classical character of the Wigner molecule in the high magnetic field. Possible mechanisms of the MDD decay are discussed.

2003-06-25

23

A Trajectory Correction based on Multi-Step Lining-up for the CLIC Main Linac  

CERN Document Server

In the CLIC main linac it is very important to minimise the trajectory excursion and consequently the emittance dilution in order to obtain the required luminosity. Several algorithms have been proposed and lately the ballistic method has proved to be very effective. The trajectory method described in this Note retains the main advantages of the latter while adding some interesting features. It is based on the separation of the unknown variables like the quadrupole misalignments, the offset and slope of the injection straight line and the misalignments of the beam position monitors (BPM). This is achieved by referring the trajectory relatively to the injection line and not to the average pre-alignment line and by using two trajectories each corresponding to slightly different quadrupole strengths. A reference straight line is then derived onto which the beam is bent by a kick obtained by moving the ...

1999-01-01

24

Technological evolution and interdependence in China's emerging biofuel industry  

British Library Electronic Table of Contents (United Kingdom)

This study uses the European Patent Office worldwide patent database and applies two-stage interactive data collection methods to reveal the evolving technological interdependence for China's emerging biofuel industry. Three findings are excerpted from our empirical results. First, due to dominant patterns of business ownership, China's biofuel technology is seen as largely based on the evolutionary strength of the foodstuff and chemical fields. Second, China's biofuel technology development has evolved in the mode of 'forward engineering', led by Chinese universities rather than initiated by the public research institutes as in the experience of other East Asian latecomers. Third, our patent map and technology trajectory analyses illustrate that China's biofuel technology tends to be appl...

2011-01-01

25

Spontaneous radiation from relativistic electrons in a taper undulator. Technical report  

Science.gov (United States)

The spectrum, angular distribution, polarization and coherence properties of the radiation emitted by relativistic electrons undulating through a quasiperiodic tapered magnetic field are studied. Tapering the wavelength and/or field strength along the undulator's axis has the effect of spreading the spectral line to higher frequencies; interference over this broader spectral range results in a more complex line shape. The angular dependence, on the other hand, is not affected by the amount of taper. The polarization of the radiation in the forward direction is determined by the transverse polarization of the undulator, but the polarization changes off axis. The radiation patterns predicted here are distinct from those of untapered undulators, and their detection is now feasible. They will provide useful diagnostics of electron trajectories and threshold behavior in free-electron-laser oscillators using tapered undulators.

1983-06-01

26

Oil Spill Simulation and Validation in the Arabian (Persian) Gulf with Special Reference to the UAE Coast  

British Library Electronic Table of Contents (United Kingdom)

The use of numerical modeling in oil spill incidents is a well established technique that has proven to provide cost-effective and reasonable estimates of oil surface drift. Good predictability of such models depends highly on the quality of the input data of the incident and on the model calibration effort. This paper presents the results of simulating oil spillage trajectory in the Arabian (Persian) Gulf. The study employed a 3-D rectilinear hydrodynamic model combined with oil spill model. Typical representative environmental conditions of the Arabian Gulf were first setup into a hydrodynamic circulation model using data from various sources. The performance of the hydrodynamic model was then tested against measurements of tidal fluctuation and sea currents at selected locations. The sp...

2007-01-01

27

Geometry of elastic hydrofracturing by injection of an over pressured non-Newtonian Fluid  

CERN Document Server

The nucleation and propagation of hydrofractures by injection of over pressured fluids in an elastic and isotropic medium are studied experimentally. Non-Newtonian fluids are injected inside a gelatine whose mechanical properties are assumed isotropic at the experimental strain rates. Linear elastic theory predicts that plastic deformation associated to breakage of gelatin bonds is limited to a small zone ahead of the tip of the propagating fracture and that propagation will be maintained while the fluid pressure exceeds the normal stress to the fracture walls (Ch\\'avez-\\'Alvarez,2008) (i.e., the minimum compressive stress), resulting in a single mode I fracture geometry. However, we observed the propagation of fractures type II and III as well as nucleation of secondary fractures, with oblique to perpendicular trajectories with respect to the initial fracture. In the Video (http://hdl.handle.net/1813/14122) experimental evidence shows that ...

2009-01-01

28

A model of episodic memory: mental time travel along encoded trajectories using grid cells.  

Science.gov (United States)

The definition of episodic memory includes the concept of mental time travel: the ability to re-experience a previously experienced trajectory through continuous dimensions of space and time, and to recall specific events or stimuli along this trajectory. Lesions of the hippocampus and entorhinal cortex impair human episodic memory function and impair rat performance in tasks that could be solved by retrieval of trajectories. Recent physiological data suggests a novel model for encoding and retrieval of trajectories, and for associating specific stimuli with specific positions along the trajectory. During encoding in the model, external input drives the activity of head direction cells. Entorhinal grid cells integrate the head direction input to update an internal representation of location, and drive hippocampal place cells. Trajectories are encoded by Hebbian ...

2009-07-15

29

Computer modeling of oil spill trajectories with a high accuracy method  

Energy Technology Data Exchange (ETDEWEB)

This paper proposes a high accuracy numerical method to model oil spill trajectories using a particle-tracking algorithm. The Euler method, used to calculate oil trajectories, can give adequate solutions in most open ocean applications. However, this method may not predict accurate particle trajectories in certain highly non-uniform velocity fields near coastal zones or in river problems. Simple numerical experiments show that the Euler method may also introduce artificial numerical dispersion that could lead to overestimation of spill areas. This article proposes a fourth-order Runge-Kutta method with fourth-order velocity interpolation to calculate oil trajectories that minimise these problems. The algorithm is implemented in the OilTrack model to predict oil trajectories following the 'Nissos Amorgos' oil spill accident that occurred in the Gulf of Venezuela in ...

1999-07-01

30

Trajectory generation for car-like robots  

Energy Technology Data Exchange (ETDEWEB)

Autonomous robots or remotely operated vehicles have raised high hopes in the military and industrial communities because of the potential safety improvement and gain of productivity they may provide. Waste management on nuclear sites, pallet manipulation in factories, interventions on battle-fields, etc., are actively studied. A lot of these applications require powerful four-wheel vehicles, the kinematics of which is similar to that of a car. Such vehicles have three degrees of freedom: the (x,y) positions in a plane and the orientation of the vehicle. Path planning is often understood as only changing the position of the vehicle, whereas the tasks performed by this kind of robot requires a perfect orientation of the vehicle: forklifting a pallet or docking at a loading or unloading station requires accuracy in the orientation of the vehicle. It is this requirement and the kinematic constraints of the motion mode which have led to the path-planning algorithm ...

1990-01-01

31

On restricted Analytic Gradients on Analytic Isolated Surface Singularities  

CERN Document Server

Let (X,O) be a real analytic isolated surface singularity at the origin o of a real analytic manifold M equipped with a real analytic metric g. Given a real analytic function f:(M,O) --> (R,0) singular at O, we prove that the gradient trajectories for the metric g|(X,O) of the restriction f|X escaping from or ending up at the origin O do not oscillate. Such a trajectory is thus a sub-pfaffian set. Moreover, in each connected component of X\\O where the restricted gradient does not vanish, there is always a trajectory accumulating at O and admitting a formal asymptotic expansion at O

2011-01-01

32

Nonlinear dynamics of a flexible rotor supported by turbulent journal bearings with couple stress fluid  

Energy Technology Data Exchange (ETDEWEB)

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

2008-08-15

33

Nonlinear dynamics of a flexible rotor supported by turbulent journal bearings with couple stress fluid  

International Nuclear Information System (INIS)

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

2008-08-01

34

Chaos and bifurcation of a flexible rotor supported by porous squeeze couple stress fluid film journal bearings with non-linear suspension  

Energy Technology Data Exchange (ETDEWEB)

This study presents a dynamic analysis of a flexible rotor supported by two porous squeeze couple stress fluid film journal bearings with non-linear suspension. The dynamics of the rotor center and bearing center are studied. The analysis of the rotor-bearing system is investigated under the assumptions of non-Newtonian fluid and a short bearing approximation. The spatial displacements in the horizontal and vertical directions are considered for various non-dimensional speed ratios. The dynamic equations are solved using the Runge-Kutta method. The analysis methods employed in this study is inclusive of the dynamic trajectories of the rotor center and bearing center, power spectra, Poincare maps and bifurcation diagrams. The maximum Lyapunov exponent analysis is also used to identify the onset of chaotic motion. The numerical results show that the stability of the system varies with the non-dimensional ...

2008-01-15

35

Chaos and bifurcation of a flexible rotor supported by porous squeeze couple stress fluid film journal bearings with non-linear suspension  

International Nuclear Information System (INIS)

This study presents a dynamic analysis of a flexible rotor supported by two porous squeeze couple stress fluid film journal bearings with non-linear suspension. The dynamics of the rotor center and bearing center are studied. The analysis of the rotor-bearing system is investigated under the assumptions of non-Newtonian fluid and a short bearing approximation. The spatial displacements in the horizontal and vertical directions are considered for various non-dimensional speed ratios. The dynamic equations are solved using the Runge-Kutta method. The analysis methods employed in this study is inclusive of the dynamic trajectories of the rotor center and bearing center, power spectra, Poincare maps and bifurcation diagrams. The maximum Lyapunov exponent analysis is also used to identify the onset of chaotic motion. The numerical results show that the stability of the system varies with the non-dimensional ...

2008-01-01

36

Stability and Change in Family Structure and Maternal Health Trajectories  

UK PubMed Central (United Kingdom)

Recent increases in births to unmarried parents, and the instability surrounding these relationships, have raised concerns about the possible health effects associated with changes in family...Full Text Available

2008-04-01

37

Real Time Trajectory Planning for Groups of Unmanned ...  

Science.gov (United States)

... kinematic model for the robots and designed ... theoretic approach for modeling mobile robot teamn formations". ... "UUV teams, control from a biological ...

2005-08-22

38

Enhanced Algorithms for EO/IR Electronic Stabilization, Clutter ...  

Science.gov (United States)

... coordinates to allow for multisensor fusion, trajectory ... of an image processing toolkit (iPTK ... effectiveness of data-driven registration processing, spatial ...

2009-09-01

39

Bioprocess control from a multivariate process trajectory.  

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 ...

2003-09-05

40

Development of magnetic separation system of magnetoliposomes  

Energy Technology Data Exchange (ETDEWEB)

The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and the filter consisting of ferromagnetic particle. By doing so, we confirmed that Fe{sub 3}O{sub 4} of 20 nm in diameter was trapped in the magnetic filter under an external magnetic field of ...

2009-10-15

41

Spinning tachyons as particle constituents  

International Nuclear Information System (INIS)

The motions of a classical free spinning point particle are extended to include the range of superluminal velocities. There is no formal change in the constraint-dependent functional relationship between observable mass and spin, i.e., trajectory, accompanying this extension. However, the theory now permits the specification, for superluminal velocities, of a linearly rising trajectory and naturally yields tachyon confinement. Therefore, unlike their subluminal counterparts, these tachyons can be considered candidates for elementary particle constituents.

42

Attractors for nonlinear reaction-diffusion systems in unbounded domains via the method of short trajectories  

CERN Document Server

We consider a nonlinear reaction-diffusion equation settled on the whole euclidean space. We prove the well-posedness of the corresponding Cauchy problem in a general functional setting, namely, when the initial datum is uniformly locally bounded in L^2. Then we adapt the short trajectory method to establish the existence of the global attractor and, if the space dimension is at most 3, we also find an upper bound of its Kolmogorov's entropy.

2009-01-01

43

Analysis of a manipulator in relation to collision between a link and an object  

British Library Electronic Table of Contents (United Kingdom)

In this article, equations of motion of a manipulator are derived after consideration of the characteristics of the driving source. By considering a collision between a link and an object, and considering the active motion to absorb the kinetic energy of the object, the trajectories for saving energy are calculated by the iterative dynamic programming (IDP) method. The dynamic characteristics of manipulator control based on the trajectory for saving energy are also analyzed theoretically and investigated experimentally.

2011-01-01

44

ADAPTATION OF THE ADVANCED STATISTICAL TRAJECTORY REGIONAL AIR POLLUTION (ASTRAP) MODEL TO THE EPA VAX COMPUTER - MODIFICATIONS AND TESTING  

Science.gov (United States)

The Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model simulates long-term transport and deposition of oxides of and nitrogen. t is a potential screening tool for assessing long-term effects on regional visibility from sulfur emission sources. owever, a rigorou...

45

Minimal Curvature Trajectories: Riemannian Geometry Concepts for Model Reduction in Chemical Kinetics  

CERN Document Server

In dissipative ordinary differential equation systems different time scales cause anisotropic phase volume contraction along solution trajectories. Model reduction methods exploit this for simplifying chemical kinetics via a time scale separation into fast and slow modes. The aim is to approximate the system dynamics with a dimension-reduced model after eliminating the fast modes by enslaving them to the slow ones via computation of a slow attracting manifold. We present a novel method for computing approximations of such manifolds using trajectory-based optimization. We discuss Riemannian geometry concepts as a basis for suitable optimization criteria characterizing trajectories near slow attracting manifolds and thus provide insight into fundamental geometric properties of multiple time scale chemical kinetics. The optimization criteria correspond to a suitable mathematical formulation of "minimal relaxation" of chemical ...

2009-01-01

46

Experiences in batch trajectory alignment for pharmaceutical process improvement through multivariate latent variable modelling  

British Library Electronic Table of Contents (United Kingdom)

The primary objective of batch data as trajectory alignment (or synchronization) is to standardize the data sampling per batch according to the evolution of the process, and secondarily to homogenize the samples per run. The use of an indicator variable performs both objectives well. Two examples from the pharmaceutical sector are discussed to illustrate the different ways to deal with uneven samples across batches and across variables in the same batch. Since trajectory alignment requires large time investment, a simple triage approach is proposed to assess the need to analyze the dynamics of a given process and hence perform alignment. The presented examples are representative of a broad variety of batch processes that are operated by recipe in the pharmaceutical sector. In our experienc...

2011-01-01

47

A new strategy of counterattacking anti-satellite based on motion camouflage  

Science.gov (United States)

Motion Camouflage (MC) is illuminated as a novel strategy in counterattacking anti-satellite by way of stealth trajectory scheduling. The dynamics model of MC in space is developed and a quadratic function with three boundary constraints is employed for trajectory determination. Based on the model a scenario is set to run the simulation. The results indicate given the designed acceleration input, the predator will be moved following a prescribed route, which precisely locates the predator between two objects at each time instant. In the last approaching phase, the motion is achieved with a big bumping rate which guarantees the power of this striking. Methods for deriving minimum fuel cost in the fixed approaching duration and the minimum approaching duration in limited acceleration input are proposed and are verified in the simulation. At last, camouflage is recognized as a multi-faceted affair, in which stealth trajectory ...

2010-08-01

48

Theory of chemical reaction dynamics. Volume 3  

Energy Technology Data Exchange (ETDEWEB)

This book examines some of the basic principles behind chemical reaction kinetics. Topics considered include the classical trajectory approach to reactive scattering; periodic orbits and theory of reactive scattering; and semiclassical reactive scattering.

1985-01-01

49

Social Change and Socioeconomic Disparities in Health over the Life Course in China: A Cohort Analysis  

UK PubMed Central (United Kingdom)

This article examines social stratification in individual health trajectories for multiple cohorts in the context of China’s dramatically changing macro-social environment. Using data...Full Text Available

2010-02-01

50

Neuronal nets in robotics  

International Nuclear Information System (INIS)

The paper gives a generic idea of the solutions that the neuronal nets contribute to the robotics. The advantages and the inconveniences are exposed that have regarding the conventional techniques. It also describe the more excellent applications as the pursuit of trajectories, the positioning based on images, the force control or of the mobile robots management, among others

51

Food meanings in HIV and AIDS caregiving trajectories: Ritual, optimism and anguish among caregivers in Lesotho  

UK PubMed Central (United Kingdom)

The article describes the caregiving responsibility to provide food for chronically ill family members and the meanings attached to food and eating when ill created stress for family caregivers. The...Full Text Available

2011-02-05

52

Trajectory of virtual, bound and resonant Efimov states  

International Nuclear Information System (INIS)

The pole trajectory of Efimov states for a three-body ??? system with ?? unbound and ?? bound is calculated using a zero-range Dirac-? potential. It is shown that a three-body bound state turns into a virtual one by increasing the ?? binding energy. This result is consistent with previous results for three equal mass particles. The present approach considers the n-n-18C halo nucleus. However, the results have good perspective to be tested and applied in ultracold atomic systems, where one can realize such three-body configuration with tunable two-body interaction. Presented at the 20th Few-Body Conference, Pisa, Italy, 10-14 September 2007. (author)

53

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

Science.gov (United States)

The health of professional bus drivers is a critical factor in their driving performance; any impairment may lead to undesired consequences. In an attempt to develop and prioritize health and wellness programs, this study investigates the factors significantly affecting the health conditions of professional bus drivers, as well as the strength of these factors. This study uses self-rated health as the examination measurement. This simple assessment is an inclusive measure of health status for judging health trajectory, and is highly associated with changes in functional ability, including perceived control over driving. This study evaluates driver responses of self-rated health with ordered response models that consider factors such as the driver reported health problems, physical and psychological conditions, demographic factors, driving experience, and working environment. Analysis of a sample of 785 ...

2011-06-24

54

Validation of the Canadian atmospheric dispersion model for small exclusion area boundaries  

International Nuclear Information System (INIS)

AECL is undertaking the validation of ADDAM, an atmospheric dispersion and dose code based on the Canadian Standards Association model CSA N288.2. The key component of the validation program involves the comparison of air concentrations predicted by the model with measured values. Measurements are available from field studies at two Canadian reactor sites and from a wind tunnel study of the CANDU site at Wol song, Korea. The measurements were obtained close enough to the release points to test the model for exclusion area boundaries as small as 500 m. Model predictions were higher than the observations almost 75 percent of the time and the magnitude of the over predictions was typically much larger than the magnitude of the under predictions. The effect of the topography at the Wol song site was limited to small changes in plume trajectory due to channeling in valleys and a small reduction in the lateral spread of the ...

1999-11-04

55

Theory of low voltage annular beam free-electron lasers  

Energy Technology Data Exchange (ETDEWEB)

An nonlinear analysis of an annular beam propagating through a cylindrical waveguide in the presence of a helical wiggler and an axial guide field is presented. The analysis is based upon the ARACHNE simulation which is a non-wiggler-averaged slow-time-scale simulation code in which the electromagnetic field is represented as a superposition of the TE and TM modes in a vacuum waveguide, and the beam space-charge waves are represented as a superposition of Gould-Trivelpiece modes. The DC self-electric and self-magnetic fields are also included in the model. ARACHNE has been extensively benchmarked against experiments at MIT and NRL in the past with good agreement, but all of these experiments have dealt with solid electron beams and beam voltages in excess of 200 kV. In seeking to reduce the beam voltage requirements we now consider the effect of operation with an annular beam. One advantage to be obtained by using an annular beam is that, for a fixed beam current, the effect of the DC ...

1995-12-31

56

Microwave axial free-electron laser with enhanced phase stability  

International Nuclear Information System (INIS)

Free-electron laser (FEL) amplifiers have demonstrated high efficiencies and high output power at microwave wavelengths. However, measurements and simulations have indicated that the present level of phase stability for these devices is not sufficient for driving linear accelerators. Fluctuations in the diode voltage, which is needed to accelerate the electron beam, are the largest cause of the shifts in the phase of the output power. Pulse-power technology cannot keep the voltage fluctuations less than 1/4%. However, we have found a scheme that will make the output phase much less sensitive to these fluctuations by exploiting the traveling wave nature of the FEL interaction. In this paper we study the phase stability issue by analyzing the dispersion relation for an axial FEL, in which the rf field is transversely wiggled and the electron trajectories are purely longitudinal. The advantage of using the axial FEL interaction instead of the ...

1995-08-21

57

The combustion aerodynamics of a pulverized coal low NO{sub x} swirl burner in an industrial boiler  

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-31

58

Stabilizing effect of the electron-beam self-fields on the phase-space trajectory in a self-amplified spontaneous emission free-electron laser operating in ultraviolet and x-ray spectral ranges  

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the FEL interaction grows exponentially.

2004-02-28

59

The semiclassical approximation for L- and M-shell Coulomb ionization by heavy charged particles  

International Nuclear Information System (INIS)

The semiclassical approximation with straight-line trajectories is applied to the Coulomb ionization of K, L and M shells by heavy charged particles. The calculational aspects are discussed in detail. Scaling relations for the experimentally relevant quantities are derived. The theoretical predictions are compared with experiment. The relation of the present work to the earlier results of the semiclassical approximation and partial-wave Born approximation is discussed in detail. (author).

60

Tachyons and cosmology  

International Nuclear Information System (INIS)

The propagating of tachyons in an expanding universe is discussed. It is shown that a primordial tachyon in the big-bang universe cannot survive unless it had very large energy initially. In an indefinitely expanding universe the tachyon trajectory turns back in time. This time barrier is found to exist even in the quantum mechanical discussion of tachyons. This property is used to set limits on the mass of a tachyon. The possible astronomical checks on the hypothesis that neutrinos or photons may be tachyonic are also discussed. (author).

61

Tachyons and cosmology  

International Nuclear Information System (INIS)

The propagation of tachyons in an expanding universe is discussed. It is shown that a primordial tachyon in the big bang universe cannot survive unless it had very large energy initially. In an indefinitely expanding universe the tachyon trajectory turns back in time. This time barrier is found to exist even in the quantum mechanical discussion of tachyons. This property is used to set limits on the mass of a tachyon. The possible astronomical checks on the hypothesis that neutrinos or photons may be tachyonic are also discussed.

62

Spin resonance strength calculations  

Energy Technology Data Exchange (ETDEWEB)

In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.

2008-10-06

63

Bragg curve spectroscopy detector for particle identification  

International Nuclear Information System (INIS)

The operation principle, construction and characteristics of the Bragg curve spectroscopy detector (BCS detector) are described. The electric field of the BCS detector is parallel to the particle trajectories. The detector was tested by 8.78 MeV and 6.02 MeV #alpha# particles from a ThC-ThC's source. The energy resolutions are 1.5% and 2.6% respectively for two groups of #alpha# particles, and the charge resolution is 2.7%. Further test experiments with heavy ions will be arranged.

64

Aerosol composition, chemistry, and source characterization during the 2008 VOCALS Experiment  

Energy Technology Data Exchange (ETDEWEB)

Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only ~0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the ...

2010-03-15

65

The frequency map for billiards inside ellipsoids  

CERN Document Server

The billiard motion inside an ellipsoid $Q \\subset \\Rset^{n+1}$ is completely integrable. Its phase space is a symplectic manifold of dimension $2n$, which is mostly foliated with Liouville tori of dimension $n$. The motion on each Liouville torus becomes just a parallel translation with some frequency $\\omega$ that varies with the torus. Besides, any billiard trajectory inside $Q$ is tangent to $n$ caustics $Q_{\\lambda_1},...,Q_{\\lambda_n}$, so the caustic parameters $\\lambda=(\\lambda_1,...,\\lambda_n)$ are integrals of the billiard map. The frequency map $\\lambda \\mapsto \\omega$ is a key tool to understand the structure of periodic billiard trajectories. In principle, it is well-defined only for nonsingular values of the caustic parameters. We present four conjectures, fully supported by numerical experiments. The last one gives rise to some lower bounds on the periods. These bounds only depend on the type of the caustics. We ...

2010-01-01

66

TTF HOM Data Analysis with Curve Fitting Method  

Energy Technology Data Exchange (ETDEWEB)

To investigate the possibility of using HOM signals induced in SC cavities as beam and cavity diagnostics, narrow band (20 MHz) data was recorded around the strong TE111-6(6{pi}/9-like) dipole modes (1.7 GHz) in the 40 L-band (1.3 GHz) cavities at the DESY TTF facility. The analyses of these data have so far focused on using a Singular Value Decomposition (SVD) technique to correlate the signals with each other and data from conventional BPMs to show the dipole signals provide an alternate means of measuring the beam trajectory. However, these analyses do not extract the modal information (i.e., frequencies and Q's of the nearly degenerate horizontal and vertical modes). In this paper, we described a method to fit the signal frequency spectrum to obtain this information, and then use the resulting mode amplitudes and phases together with conventional BPM data to determine the mode polarizations and relative centers and tilts. Compared with the SVD ...

2009-07-14

67

Ozone transport from stratosphere to troposphere  

International Nuclear Information System (INIS)

"7Be produced by the interaction of cosmic rays with oxygen and nitrogen, predominantly in the stratosphere, has been used to identify and measure stratospheric ozone at the ground level. Simultaneous measurements at Whiteface Mountain, New York, in July 1975 show that the maximum "7Be concentrations are accompanied by increased ozone concentrations. Peaks in "7Be concentrations occurred on July 5-6, 11-12, 16-17, 23, and 27. Ozone peaks were observed on July 7-9, 11, 18, 24, and 27. Isentropic trajectory calculations also showed that the trajectories reaching Whiteface Mountain on July 11-12, 15-16, 23, and 27 had stratospheric origin. One-day delay in ozone peaks on July 7-9, 18, and 24 is attributed to increased tropospheric ozone production. The observed relationship between "7Be and ozone is used to deduce an upper limit of 37 ppb stratospheric ozone at Whiteface Mountain during July 1975. Thus, even during midsummer months, when ...

68

Jacobi stability of the vacuum in the static spherically symmetric brane world models  

International Nuclear Information System (INIS)

We analyze the stability of the structure equations of the vacuum in the brane world models, by using both the linear (Lyapunov) stability analysis, and the Jacobi stability analysis, the Kosambi-Cartan-Chern theory. In the brane world models the four-dimensional effective Einstein equations acquire extra terms, called dark radiation and dark pressure, respectively, which arise from the embedding of the three-brane in the bulk. Generally, the spherically symmetric vacuum solutions of the brane gravitational field equations have properties quite distinct as compared to the standard black hole solutions of general relativity. We close the structure equations by assuming a simple linear equation of state for the dark pressure. In this case the vacuum is Jacobi stable only for a small range of values of the proportionality constant relating the dark pressure and the dark radiation. The unstable trajectories on the brane behave chaotically, in the sense that after a ...

2008-05-15

69

Exploring Neutrino Mixing with Low Energy Superbeams  

CERN Document Server

We explore as clearly as possible the features of neutrino oscillation which are relevant for measurements of the CP violating Kobayashi-Maskawa phase delta and the sign of \\Delta m^2_{13}. We focus on the so called low-energy option and discuss principles for optimizing experimental parameters to measure these two quantities simultaneously. Toward the goal, we first formulate a method for obtaining a bird-eye view of the phenomenon of neutrino oscillation by introducing a new powerful tool called the ``CP trajectory diagram in bi-probability space''. It allows us to represent pictorially the three effects separately in a single diagram; effect from genuine CP violation due to the sin delta term, effect from the CP conserving cos delta term, and the fake CP violating effect due to earth matter. By using the CP trajectory diagram we observe that there is a two-fold ambiguity in the determination of delta which is related with the sign of Delta ...

2001-01-01

70

Effect of velocity variation on secondary-ion-emission probability: Quantum stationary approach  

Energy Technology Data Exchange (ETDEWEB)

The ion-velocity dependence of the ionization probability for an atom ejected from a surface is examined by using a quantum approach in which the coupled motion between electrons and the outgoing nucleus is followed along the whole trajectory by solving the stationary Schroedinger equation. We choose a very-small-cluster-model system in which the motion of the atom is restricted to one dimension, and with energy potential curves corresponding to the involved channels varying appreciably with the atom position. We found an exponential dependence on the inverse of the asymptotic ion velocity for high emission energies, and a smoother behavior with slight oscillations at low energies. These results are compared with those obtained within a dynamical-trajectory approximation using either a constant velocity equal to the asymptotic ionic value, or expressions for the velocity derived from the eikonal approximation and from the classical limit of the ...

1989-11-01

71

[Special cases of vascular injuries by war projectiles].  

Science.gov (United States)

The author resumes what is actually known about the behaviour of war projectiles in the target (wound ballistics). This is function of their nature, their velocity, their air trajectory. The difference between lesions due to slow moving bullets and these due to projectiles with a high kinetic energy is outlined. The last ones create, through the temporary cavitation effect, lesions at distance from the residual visible tract, particularly in the vascular conduits. The therapeutic conclusions, which derive from those ballistic behaviours, are briefly described in matter of repair of vascular war injuries [Acta chir. belg., 1982, 82, 457-461]. PMID:7148288

72

The use of a mesoscale numerical model for evaluations of pollutant transport and diffusion in coastal regions and over irregular terrain  

Energy Technology Data Exchange (ETDEWEB)

A modelling approach is presented that appears to have the potential to provide reliable assessments of pollution concentration in coastal zones and complex terrain, where the assumptions behind current operational air quality models often are inadequate. With the use of a numerical mesoscale model (NMM), physically consistent flow fields can be predicted, thereby providing higher spatial and temporal resolution in the meteorological fields than would be available from a limited number of observation points. These predictions are used to calculate mean trajectories of pollutant parcels, as well as to provide quantitative estimates of pollution concentration using two techniques.

1983-03-01

73

Tachyon cosmology, supernovae data, and the big brake singularity  

International Nuclear Information System (INIS)

We compare the existing observational data on type Ia supernovae with the evolutions of the Universe predicted by a one-parameter family of tachyon models which we have introduced recently [Phys. Rev. D 69, 123512 (2004)]. Among the set of the trajectories of the model which are compatible with the data there is a consistent subset for which the Universe ends up in a new type of soft cosmological singularity dubbed big brake. This opens up yet another scenario for the future history of the Universe besides the one predicted by the standard #LAMBDA#CDM model.

2009-04-15

74

Modeling the Effects of Velocity, Spin, Frictional Coefficient, and Impact Angle on Deflection Angle in Near-elastic Collisions of Phenolic Resin Spheres  

CERN Document Server

A simple model is outlined to describe the collision of cast phenol-formaldehyde resin spheres such as the balls used in the parlor game of pocket billiards, based in part on the famous analysis of elastic collisions developed by Heinrich Hertz over 100 years ago. The analysis treats the normal and tangential components of the initial sphere's velocity independently as it collides with a stationary identical second sphere. The collective effects of these and other parameters on the trajectory of the second sphere are provided in the conclusions.

2004-01-01

75

Mixed convection flow in a horizontal rectangular channel subjected to a horizontal thermal gradient  

British Library Electronic Table of Contents (United Kingdom)

This paper deals with a mixed convection water flow in a horizontal rectangular duct, uniformly heated from one lateral vertical wall and thermally insulated elsewhere. The supplied heat flux induces a secondary flow, which structure is constituted of one longitudinal roll in the considered aspect ratio (??=?1.9), embedded into a return flow of possibly large stream wise extension (up to twenty channel heights). Such situation induces helicoidal trajectories for the fluid flow particles, which contributes to a heat transfer enhancement compared to purely forced convection flow.

2011-01-01

76

Mixed convection flow in a horizontal rectangular channel subjected to a horizontal thermal gradient  

Science.gov (United States)

This paper deals with a mixed convection water flow in a horizontal rectangular duct, uniformly heated from one lateral vertical wall and thermally insulated elsewhere. The supplied heat flux induces a secondary flow, which structure is constituted of one longitudinal roll in the considered aspect ratio (? = 1.9), embedded into a return flow of possibly large stream wise extension (up to twenty channel heights). Such situation induces helicoidal trajectories for the fluid flow particles, which contributes to a heat transfer enhancement compared to purely forced convection flow.

2011-04-01

77

Method for the approximate solution of a two-phase stefan problem with reverse motion of the front  

Science.gov (United States)

Determination of the trajectory of a phase transition front moving in a forward or reverse direction is reduced to the solution of an ordinary differential equation. A numerical check of the results shows the method to be highly accurate. The method was used recently over a period of several years to solve various problems connected with the thawing of frozen rocks and their refreezing; among the problems considered was that of the ablation of rocks during the channeling of well, in which the method invariably proved its effectiveness. This furnishes a basis for recommending it for broader usage.

1988-03-01

78

Bragg-curve spectroscopy detector  

Energy Technology Data Exchange (ETDEWEB)

In an ionization chamber with the electric field parallel to the particle trajectories, the time dependence of the anode signal contains all the information about the energy and the nuclear charge of the ionizing particle. By proper pulse shaping with a long and a short time constant the total ionization charge and the ionization charge integrated around the Bragg maximum, respectively, can be obtained. The former signal is proportional to the total energy, whereas the latter allows the nuclear charge to be deduced directly. An energy resolution of 0.4% and a Z resolution ..delta..Z/Z = 1/82 was achieved for 130 MeV /sup 32/S ions and argon-methane as the stopping medium.

1982-02-01

79

Beam position monitor readout and control in the SLC linac  

Energy Technology Data Exchange (ETDEWEB)

A beam position monitoring system has been implemented in the first third of the SLC linac which provides a complete scan of the trajectory on a single beam pulse. The data is collected from the local micro-computers and viewed with an updating display at a console or passed on to application programs. The system must operate with interlaced beams so the scans are also interlaced, providing each user with the ability to select the beam, the update rate, and the attenuation level in the digitizing hardware. In addition each user calibrates the hardware for his beam. A description of the system architecture will be presented. 6 refs., 4 figs.

1985-04-01

80

Ancient cosmological tachyons in the present-day world  

Energy Technology Data Exchange (ETDEWEB)

The geodesic equation for space-like objects moving along a circular trajectory in the expanding universe is considered. Our analysis leads to the conclusion that ancient cosmological tachyons may exist in the present-day world and may play an important role in (i) the internal structure of hadrons conceived as nonlocal objects called strings, (ii) the T-symmetry violation observed in the weak K-decays, (iii) the multidimensional unified field theories of Kaluza-Klein type, and in (iv) the classical models of charged particles which combine ordinary electromagnetism with a self-interacting version of Newtonian gravity. 18 refs.

1993-06-01

81

Ancient cosmological tachyons in the present-day world  

International Nuclear Information System (INIS)

The geodesic equation for space-like objects moving along a circular trajectory in the expanding universe is considered. Our analysis leads to the conclusion that ancient cosmological tachyons may exist in the present-day world and may play an important role in (i) the internal structure of hadrons conceived as nonlocal objects called strings, (ii) the T-symmetry violation observed in the weak K-decays, (iii) the multidimensional unified field theories of Kaluza-Klein type, and in (iv) the classical models of charged particles which combine ordinary electromagnetism with a self-interacting version of Newtonian gravity. 18 refs.

82

A multiple sampling proportional counter for particle identification of relativistic heavy ions  

Energy Technology Data Exchange (ETDEWEB)

A multiple sampling dE/dx counter using a multiwire proportional chamber equipped with catbode pads was constructed for the multiple detection of dE/dx values along a particle trajectory. For low-energy particles this counter was proved to be useful as a Bragg-curve detector. At relativistic energies around E=14.6 GeV/nucleon good particle identification was obtained by cathode pad signals as well as anode signals for the range of projectile fragments from Z=1 (minimum ionization) up to a beam charge of Z=14. (orig.).

1990-11-15

83

Final technical report for ''Frontiers in Plasma Kinetic Theory''  

International Nuclear Information System (INIS)

This report summarizes the results and activities funded by this three-year award. The principal goal of this project was to determine the thermal conductivity in clusters of galaxies. Intracluster plasmas possess chaotic magnetic fields. Since charged particles are constrained to move primarily along magnetic field lines, the topology of intracluster magnetic fields slows particle diffusion relative to the non-magnetized case, thereby reducing the thermal conductivity. Our first approach to this problem was to employ the static-magnetic-field approximation. In reality, intracluster magnetic field lines are constantly moving, since they are advected by turbulent intracluster motions. The turbulent velocities, however, are much smaller than the rapid speeds of thermal electrons, which make the dominant contribution to the thermal conductivity. In the static-field approximation, one neglects turbulent motions of field lines, and calculates the diffusion coefficient of thermal electrons ...

2007-02-01

84

Numerical ray tracing of electrons in different 3D fringing fields of spherical deflectors  

Science.gov (United States)

This paper presents the results of numerical investigations on electron trajectories in different 3D fringing fields of spherical defectors. We start with a chosen set of geometrical values for the electrodes such as radius of curvature, electrode gap, angle between entrance and exit face. We do a first numerical calculation of the spatial potential distribution using a 3D electron optics program based on the finite difference method (FDM). Ray tracing through this potential distribution is then performed using another program, which also gives the potential and the electric field strength along the curved beam path. In the next step we estimate the position and the geometry of the field clamp using Herzog's formulae assuming the entrance of a parallel plate condenser to be a good approximation for the entrance of the spherical deflector in first order. For the consecutive numerical recalculations of the real potential distribution of the spherical deflector with ...

1999-11-01

85

Dynamical Cycles in Charge and Energy for Iron Ions Accelerated in a Hot Plasma  

Science.gov (United States)

We consider a unified model of Fe ion acceleration in the solar corona. The model comprises charge-changing processes, Coulomb energy losses, and both regular and stochastic acceleration. At a given acceleration scenario, the type of acceleration is found to have a minor effect on the mean charge states, but the shapes of the charge-state distributions produced by regular acceleration and by stochastic acceleration are different. During a continual acceleration at coronal temperatures, iron ions typically follow rising trajectories on the charge-energy plane. These trajectories are situated below the mean equilibrium charge curve defined from the balance of ionization and recombination at fixed energy. During stopping, the iron ions cross the equilibrium charge curve and run through a series of charge states above the mean equilibrium charge at current energy, because the Coulomb deceleration rate significantly exceeds the rate of the ion ...

2001-08-01

86

Energy optimal synthesis of perodic motions in multibody systems; Energieoptimale Synthese periodischer Arbeitsbewegungen in Mehrkoerpersystemen  

Energy Technology Data Exchange (ETDEWEB)

In robotics inverse dynamics is a standard control concept for highly nonlinear multibody systems. It is shown, however, that inverse dynamics results in a high energy demand. Therefore, linear energy efficient state feedback controllers are designed in a way that a performance index representing the energy consumption is minimized. At the same time inequality constraints such as control error and limited input variables have to be met. For the control design an analytical solution by pole placement is presented as well as a numerical controller optimization. This control design includes small motions in the neighborhood of the operating point. Then, linear controllers are tested with respect to control error and energy consumption when undergoing large displacement motion. It is shown that linear state feedback can only save energy if large control errors are accepted. Therefore, nonlinear systems are optimized as a whole by implementation of springs as local energy storage. Two ...

2006-07-01

87

Three-dimensional, three-component wall-PIV  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert's law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle's projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional artificial data set simulating a rotating sphere. (orig.)

2010-06-15

88

Risk analysis in oil spill response planning  

Energy Technology Data Exchange (ETDEWEB)

Tiered response is a basic approach to emergency plans, including oil spill response (OSR). This paper delineates a huge set of accidental scenarios within a certain tier of response generated by a computer during risk assessment. Parameters such as the amount of oil spilled, duration of discharge and types of losses should be provided in OSR scenarios. Examples of applications include offshore installations, sub sea or onshore pipelines, and localized onshore facilities. The paper demonstrates how to use risk analysis results for delineating all likely spills into groups that need a specific tier response. The best world practices and Russian regulatory approaches were outlined and compared. Corresponding algorithms were developed and their application in pipelines was presented. The algorithm combines expert's skills and spill trajectory modeling with the net environmental benefit analysis principle into the incident specific emergency response planning. ...

2005-07-01

89

Radiation electromagnetic effect in germanium crystals under high-energy #alpha#-particle irradiation  

International Nuclear Information System (INIS)

Results of experimental investigation into radiation electromagnetic effect (REM) in samples of germanium crystals under approximately 40 MeV #alpha#-particle irradiation in a cyclotron are presented. A high level of excitation, volumetric character of generation of non-equilibrium carriers and formation of defects as well as the form of their spatial distribution are shown to result in some peculiarities of the EMF of the REM effect on the particle flux, fluence and sample parameters. Agreement of theoretical calculations, conducted with account of specificity of #alpha#-particle interaction with a crystal, and experimental data is obtained. It is revealed that the REM effect can be applied in obtaining data on spatial distribution of non-equilibrium carrier concentrations along the particle trajectory in the crystal.

90

Pseudospectral method calculation of tidal field and particle random walk simulation of radionuclides in Daya Bay  

International Nuclear Information System (INIS)

Presented here is the calculation results of tidal field of Daya Bay by using pseudospectral method. According to the calculation results about the tidal field and measured value of wind in Daya Bay area, the diffusion of radionuclide from Daya Bay Nuclear Power Plant is simulated by using particle random walk model. The simulation results about the relative concentration distribution of the radionuclides and the trajectory of the distribution centrode are obtained, taking account of tidal current, wind and turbulent current. These results can provide information not only for the reasonable discharge of the radionuclides from Daya Bay Nuclear Power Plant, but also for understanding the potential effect on environment due to the normal operation of Daya Bay Nuclear Power Plant. (authors)

2009-11-01

91

Proton-proton scattering above 3 GeV/c  

Energy Technology Data Exchange (ETDEWEB)

A large set of data on proton-proton differential cross sections, analyzing powers and the double-polarization parameter A{sub NN} is analyzed employing the Regge formalism. We find that the data available at proton beam momenta from 3GeV/c to 50GeV/c exhibit features that are very well in line with the general characteristics of Regge phenomenology and can be described with a model that includes the {rho}, {omega}, f{sub 2}, and a{sub 2} trajectories and single-Pomeron exchange. Additional data, specifically for spin-dependent observables at forward angles, would be very helpful for testing and refining our Regge model. (orig.)

2010-09-15

92

Precipitation of ions induced by nonadiabatic motion in the outer cusp region  

Science.gov (United States)

The transport of magnetospheric particles in the outer cusp region is examined by means of three-dimensional single particle codes. It is shown that, at high altitudes, particles can experience nonadiabatic motions leading to significant magnetic moment changes. It is demonstrated that this nonadiabatic behavior can be interpreted, at least partly, by the action of an impulsive centrifugal force perturbing the particle gyromotion. Systematic trajectory calculations reveal that plasma sheet ions which ExB convert toward the magnetopause from low L-shells in the dayside sector are subjected to such nonadiabatic motions. As a result of magnetic moment damping, a number of them are injected into the loss cone and subsequently precipitate near the cusp equatorward edge.

93

Online monitoring of steel casting processes using multivariate statistical technologies: From continuous to transitional operations  

British Library Electronic Table of Contents (United Kingdom)

This paper describes a state-of-the-art online monitoring system using multivariate statistical technologies for continuous steel casting process, which was commissioned at Dofasco's No. 2 caster to provide consistent indication of process health for caster's start-up, continuous production and transitional operations. The paper particularly focuses on development of a novel scheme to synchronize process trajectories for monitoring specific transitional operations such as equipment or steel product grade changes. The proposed scheme is demonstrated by several industrial examples with the results showing good detectability of various process abnormalities. With the aid of this fully integrated, innovative monitoring system, Dofasco has generated significant value through improved productivi...

2006-01-01

94

Numerical modeling of a Global Navigation Satellite System in a general relativistic framework  

CERN Document Server

In this article we model a Global Navigation Satellite System (GNSS) in a Schwarzschild space-time, as a first approximation of the relativistic geometry around the Earth. The closed time-like and scattering light-like geodesics are obtained analytically, describing respectively trajectories of satellites and electromagnetic signals. We implement an algorithm to calculate Schwarzschild coordinates of a GNSS user who receives proper times sent by four satellites, knowing their orbital parameters; the inverse procedure is implemented to check for consistency. The constellation of satellites therefore realizes a geocentric inertial reference system with no \\emph{a priori} realization of a terrestrial reference frame. We show that the calculation is very fast and could be implemented in a real GNSS, as an alternative to usual post-Newtonian corrections. Effects of non-gravitational perturbations on positioning errors are assessed, and methods to reduce them are ...

2010-01-01

95

Multi-GeV electron spectrometer  

Energy Technology Data Exchange (ETDEWEB)

The advance in laser-plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1nC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence present unprecedented challenges in the design and construction ...

2010-11-11

96

Local binary pattern based features for sign language recognition  

British Library Electronic Table of Contents (United Kingdom)

In this paper we focus on appearance features describing the manual component of Sign Language particularly the Local Binary Patterns. We compare the performance of these features with geometric moments describing the trajectory and shape of hands. Since the non-manual component is also very important for sign recognition we localize facial landmarks via Active Shape Model combined with Landmark detector that increases the robustness of model fitting. We test the recognition performance of individual features and their combinations on a database consisting of 11 signers and 23 signs with several repetitions. Local Binary Patterns outperform the geometric moments. When the features are combined we achieve a recognition rate up to 99.75% for signer dependent tests and 57.54% for signer indep...

2011-01-01

97

Invariant asymptotic observers  

CERN Document Server

This paper presents three non-linear asymptotic observers corresponding to three examples of engineering interest: a chemical reactor, a non-holonomic car, and an inertial navigation system. For each example, the design is based on physical symmetries. This motivates the theoretical development of invariant observers, i.e, symmetry-preserving observers. We consider an observer to consist in a copy of the system equation and a correction term, and we give a constructive method (based on the Cartan moving-frame method) to find all the symmetry-preserving correction terms. They rely on an invariant frame (a classical notion) and on an invariant output-error, a less standard notion precisely defined here. For each example, the convergence analysis relies also on symmetries consideration with a key use of invariant state-errors. For the non-holonomic car and the inertial navigation system, the invariant state-errors is shown to obey an autonomous differential equation independent of the ...

2006-01-01

98

Experimental investigations of plasma bullets  

International Nuclear Information System (INIS)

Recently several investigators reported on various means of generating cold plasma jets at atmospheric pressure. More interestingly, these jets turned out to be not continuous plasmas but trains of small high velocity plasma packets/bullets. However, until now little is known of the nature of these 'bullets'. Here we present experimental insights into the physical and chemical characteristics of bullets. We show that their time of initiation, their velocity and the distance they travel are directly dependent on the value of the applied voltage. We also show that these bullets can be controlled by the application of an external electric field. Using an intensified charge coupled device camera we report on their geometrical shape, which was revealed to be 'donut' shaped, therefore giving an indication that solitary surface ionization waves may be responsible for the creation of these bullets. In addition, using emission spectroscopy, we follow the evolution of various species along the ...

2009-03-07

99

Effect of Kerr nonlinearity on an Airy beam  

International Nuclear Information System (INIS)

The effect of Kerr nonlinearity on an Airy beam is investigated by using the nonlinear Schroedinger equation. Based on the moments method, the evolution of the Airy beam width in the rms sense is analytically described. Numerical simulations indicate that the central parts of the major lobe of the Airy beam initially give rise to radial compression during propagation in a focusing medium, even though the rms beam width broadens. The partial collapse of the center parts of the major lobe of the beam appear below the threshold for a global collapse. The evolutions of the field distributions of the Airy beams are different during propagation in different Kerr media while the beams still travel along the parabolic trajectory just as the beam propagates in free space.

2010-10-01

100

Diversity of Tropical Tree Seedling Responses to Drought  

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT Drought is an important seedling mortality agent in dry and moist tropical forests, and more severe and frequent droughts are predicted in the future. The effect of drought on leaf gas exchange and seedling survival was tested in a dry-down experiment with four tree species from dry and moist forests in Bolivia. Seedlings were droughted and wilting stage and gas exchange were monitored. Drought led to a gradual reduction of photosynthesis and stomatal conductance over time, whereas respiration and photosynthetic water-use efficiency initially increased with drought and then declined. Seedlings gradually went through the different wilting stages, until they eventually died, but the trajectory differed for the four species. The strong relationship between wilting stage and photosynt...

2007-01-01

101

Development of the Weapon Borne Sensor parachute system  

Energy Technology Data Exchange (ETDEWEB)

A parachute system was designed and prototypes built to deploy a telemetry package behind an earth-penetrating weapon just before impact. The parachute was designed to slow the 10 lb. telemetry package and wire connecting it to the penetrator to 50 fps before impact occurred. The parachute system was designed to utilize a 1.3-ft-dia cross pilot parachute and a 10.8-ft-dia main parachute. A computer code normally used to model the deployment of suspension lines from a packed parachute system was modified to model the deployment of wire from the weapon forebody. Results of the design calculations are presented. Two flight tests of the WBS were conducted, but initiation of parachute deployment did not occur in either of the tests due to difficulties with other components. Thus, the trajectory calculations could not be verified with data. Draft drawings of the major components of the parachute system are presented.

1998-06-01

102

Development of a 1D neutron transport code employing the method of characteristics  

International Nuclear Information System (INIS)

To investigate the 2D/1D fusion core analysis method, a 1D neutron transport problem solver, PEACH-ID, is developed. It is a code of method of characteristics (MOC), both the usual fiat-source step characteristics (SC) scheme and linear source (LS) approximation scheme are adopted for tracking calculation along the neutron flying trajectory. Exponential function interpolation table and fission source extrapolation are adopted as two major methods to accelerate the computational process. Numerical results demonstrate that PEACH-1D is accurate and efficient, and the proposed LS scheme is able to handle quite larger mesh division and deserves much more application in the MOC codes. (authors)

2009-09-01

103

Computer simulations of reacting particle-laden jet mixing applied to SO_2 control by dry sorbent injection  

International Nuclear Information System (INIS)

A particle-laden turbulent reacting flow model is described and applied to in-furnace, dry SO_2 control in boilers. Sulfur capture by calcium-based sorbents is represented by a shrinking core model which accounts for surface areas loss and product layer diffusion. Sorbent particle trajectories and dispersion are followed with cloud statistics in a Lagrangian framework. The turbulent fluid mechanics and chemical reactions are coupled, and solutions obtained for mean and fluctuating velocity, composition, and particle position. Comparisons are made with data from an US EPA laboratory reactor. Practical implications for SO_2 control are examined including the effects of jet velocity, sorbent injection location, boiler load and thermal profiles.

1992-11-01

104

Coherent Smith-Purcell radiation in the far-infrared region from a short-bunched electron beam  

International Nuclear Information System (INIS)

Coherent Smith-Purcell radiation, emitted from short-bunched electrons passing by a lamellar-type grating of aluminum, has been observed in the millimeter wave region. The energy of the electrons is either 42 MeV when they are accelerated by an L-band linear accelerator or 150 MeV accelerated by an S-band one. The intensity of the radiation is proportional to the square of the beam current. The radiation is linearly polarized, and the electric vector of the radiation is in the plane defined by the observing point and the beam trajectory. The intensity decreases with the beam height, i.e. the distance of the beam from the surface of the grating, in accordance with the modified Bessel function of zeroth order. copyright 1996 American Institute of Physics.

1995-09-28

105

Beam emittance measurements of ORNL negative ion sources  

Energy Technology Data Exchange (ETDEWEB)

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

1989-01-01

106

Application of chaos theory in identification of two-phase flow patterns and transitions in a small, horizontal, rectangular channel  

Energy Technology Data Exchange (ETDEWEB)

Various measurement tools that are used in chaos theory were applied to analyze two-phase pressure signals with the objective of identifying and interpreting flow pattern transitions for two-phase flows in a small, horizontal rectangular channel. These measurement tools included power spectral density function, autocorrelation function, pseudo-phase-plane trajectory, Lyapunov exponent,s and fractal dimensions. It was demonstrated that the randomlike pressure fluctuations characteristic of two-phase flow in small rectangular channels are chaotic, and governed by a high-order deterministic system. The correlation dimension is potentially a new approach for identifying certain two-phase flow patterns and transitions.

1996-06-01

107

Antimatter production in supernova remnants  

CERN Document Server

We calculate the energy spectra of cosmic rays (CR) and their secondaries produced in a supernova remnant (SNR), taking into account the time-dependence of the SNR shock. We model the trajectories of charged particles as a random walk with a prescribed diffusion coefficient, accelerating the particles at each shock crossing. Secondary production by CRs colliding with gas is included as a Monte Carlo process. We find that SNRs produce less antimatter than suggested previously: The positron/electron ratio and the antiproton/proton ratio are a few percent and few $\\times 10^{-5}$, respectively. Moreover, the obtained positron/electron ratio decreases with energy, while the antiproton/proton ratio rises at most by a factor of two above 10 GeV.

2011-01-01

108

Abscisic Acid in Soil Facilitates Community Succession in Three Forests in China  

British Library Electronic Table of Contents (United Kingdom)

Plants release secondary metabolites into the soil that change the chemical environment around them. Exogenous abscisic acid (ABA) is an important allelochemical whose role in successional trajectories has not been examined. We hypothesized that ABA can accumulate in the soil through successional processes and have an influence on forest dynamics. To this end, we investigated the distribution of ABA in forest communities from early to late successional stages and the response of dominant species to the gradient of ABA concentrations in three types of forests from northern to southern China. Concentrations of ABA in the soils of three forest types increased from early to late successional stages. Pioneer species? litters had the lowest ABA content, and their seed germination and seedling ea...

2011-01-01

109

A principle of charged particle trapping by RF electromagnetic field in the spherical cavity  

Energy Technology Data Exchange (ETDEWEB)

A new principle of particle trapping in the simple spherical cavity using both electric and magnetic components of radiofrequency electromagnetic field is proposed. The electric component of H {sub 12} oscillating mode drives the fast particle oscillations, while the magnetic component synchronously bends the trajectories to the cavity center. A specially developed theory of particle stability predicts dense and energetic electron cluster in the trap. Numerical simulations of particle dynamics in the complete electromagnetic field taking into account both space charge and particle-induced magnetic field are in good agreement with the analytic results, giving a density of 2.6*10{sup 1} electrons/cm{sup 3} and an average kinetic energy of around 30 keV at an operating frequency of 3 GHz. Being used at lower frequency, spherical cavity can trap protons and heavier ions too, but with lower density and kinetic energy.

2005-11-21

110

A novel approach for measuring the radial distribution of charge in a heavy ion track  

International Nuclear Information System (INIS)

The energy deposited by the passage of a single, energetic, heavy-ion through a semiconductor produces dense electron-hole (eh) pair concentrations near the ion trajectory. The size, shape, and charge density of an ion track represent critical parameters for many models of single event phenomena. The authors describe the design and uses of possible semiconductor test structures for measuring the initial radial distribution of charge and subsequent charge transport in a high energy, heavy-ion track. Numerical simulations show how the test structure can resolve different radial distributions of charge within an ion track. The test structure simulations also show the importance of accurately representing ion track structure in single event effects simulations.

1994-07-18

111

Fiscal 1996 report on the results of the subsidy operation under the Sunshine Project on the development of a geothermal water use power plant, etc. Development of the binary cycle power plant (development of the measurement while drilling system for geothermal wells); 1996 nendo New Sunshine keikaku hojo jigyo seika hokokusho. Nessui riyo hatsuden plant nado kaihatsu (binary cycle hatsuden plant no kaihatsu (chinetsusei kussakuji kotei joho kenchi system no kaihatsu))  

Energy Technology Data Exchange (ETDEWEB)

The R and D were carried out of a detecting system for measurement of data on the bottom of geothermal well, data transmission and signal processing, and an analysis system for well drilling trajectory control and well assessment while geothermal well drilling based on the data obtained by the detecting system. The paper reported the results of the technology development in fiscal 1996. In the development of the detecting system, improvement/design were conducted on a mud pulse generator constituting sonde, well bottom signal processing equipment, mode switch and inclined information sensor, and the system equivalent to the actual one was manufactured to conduct a running test at high temperature/pressure. Moreover, a test to confirm heat resistance of electronic parts was made for further improvement in heat resistance of the sonde, in order to obtain the data. In the development of an analysis system, conducted were enhancement of operability of the ...

1997-03-01

112

Visions of tomorrow: a focus on national space transportation issues; Proceedings of the Twenty-fifth Goddard Memorial Symposium, Greenbelt, MD, Mar. 18-20, 1987  

Science.gov (United States)

The present conference on U.S. space transportation systems development discusses opportunities for aerospace students in prospective military, civil, industrial, and scientific programs, current strategic conceptualization and program planning for future U.S. space transportation, the DOD space transportation plan, NASA space transportation plans, medium launch vehicle and commercial space launch services, the capabilities and availability of foreign launch vehicles, and the role of commercial space launch systems. Also discussed are available upper stage systems, future space transportation needs for space science and applications, the trajectory analysis of a low lift/drag-aeroassisted orbit transfer vehicle, possible replacements for the Space Shuttle, LEO to GEO with combined electric/beamed-microwave power from earth, the National Aerospace Plane, laser propulsion to earth orbit, and a performance analysis for a laser-powered SSTO vehicle.

1987-01-01

113

Trishear fault-propagation folding  

Energy Technology Data Exchange (ETDEWEB)

Previous models of fault-propagation folding used kink-band geometries to approximate folding in front of propagating thrusts. However, kink-band kinematics cannot replicate the curved fold surfaces and complex strain patterns innatural and experimental fault-propagation folds, which also occur in front of steeper reverse and normal faults. Fault-propagation fold hinges tighten and converge downward, forming a triangular zone of penetrative deformation focused on the tip of the propagating fault. The downward convergence of deformation in fault-propagation folds can be modeled as triangular shear zones. Trishear, here defined as distributed, strain-compatible shear in a triangular (in profile) shear zone, provides an alternate kinematic model for fault-propagation folds. Trishear is analogous to simple shear in a tabular shear zone except that area balance in a triangular shear zone requires curved displacement oblique to the fault slip direction. Incremental computer models of ...

1991-06-01

114

Three-dimensional power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

Power system stabilizers (PSSs) are used to enhance damping of power system oscillations through excitation control of synchronous generator. The objective of the PSS is to generate a stabilizing signal, which produces a damping torque component on the generator shaft. Conventional PSSs are designed with the phase compensation technique in the frequency domain and include the lead-lag blocks whose parameters are determined according to a linearized power system model. The performance of conventional PSSs (CPSSs) depends upon the generator operating point and the system parameters, but a reasonable level of robustness can be achieved depending on the tuning method. This paper presents a new three-dimensional PSS (3D PSS), which uses rotor speed deviation, rotor acceleration and load angle deviation as input signals. The 3D PSS attempts to return the generator to the state-space origin, based on the generator's trajectory in state-space and the achievement ...

2010-07-15

115

Three-Dimensional Wing Kinematics and Aerodynamic Characteristics of a Beetle in Free Flight  

Science.gov (United States)

Detailed three dimensional wing kinematics and aerodynamic characteristics are experimentally presented for the free flight of a beetle, Allomyrina dichotoma, which has a pair of elytra (fore wings) and hind wings. The kinematic parameters of the wing motion, such as the wing tip trajectory, angle of attack, torsion angle, and camber deformation, are obtained from a 3D reconstruction technique that involves the use of two or three synchronized high-speed cameras to digitize various points marked on the wings. Our data show outstanding characteristics of wing deformation and flexibility in the free flight of the beetle. To find out the mechanism of aerodynamic force, the leading edge vortex (LEV) and trailing edge vortex (TEV) on both elytron and hind wing were observed by using smoke wire visualization and digital particle image velocimetry (DPIV) technique. Qualitative smoke lines in the region of the most intent vortex shedding demonstrate clearly the interaction ...

2010-11-01

116

Residence time probability analysis of sulfur concentrations at Grand Canyon National Park  

Energy Technology Data Exchange (ETDEWEB)

A statistical method is developed to determine the locations of major pollutant sources affecting a distant downwind receptor, provided that air trajectories can be estimated. Probability density functions are estimated which indicate the overall residence time of air parcels over a given geographic region as they travel toward a receptor and residence time for the case of high pollutant concentrations at the receptor. These functions are used to estimate a conditional probability function which indicates the potential for a source region to contribute to high air pollution concentrations. Finally, a source contribution function is formulated to indicate the relative contribution of different source regions to high concentrations at the receptor. The method is tested using data collected at Grand Canyon National Park in 1980. The dominant pathway for air masses arriving at Grand Canyon during this period was southern California. A lesser pathway was from the border ...

1985-01-01

117

Ray Tracing Simulations of Weak Lensing by Large-Scale Structure  

CERN Document Server

We investigate weak lensing by large-scale structure using ray tracing through N-body simulations. Photon trajectories are followed through high resolution simulations of structure formation to make simulated maps of shear and convergence on the sky. Tests with varying numerical parameters are used to calibrate the accuracy of computed lensing statistics on angular scales from about 1 arcminute to a few degrees. Various aspects of the weak lensing approximation are also tested. For fields a few degrees on a side the shear power spectrum is almost entirely in the nonlinear regime and agrees well with nonlinear analytical predictions. Sampling fluctuations in power spectrum estimates are investigated by comparing several ray tracing realizations of a given model. For survey areas smaller than a degree on a side the main source of scatter is nonlinear coupling to modes larger than the survey. We develop a method which uses this effect to estimate the mass density ...

2000-01-01

118

Radio Frequency Plasma Applications for Space Propulsion  

Energy Technology Data Exchange (ETDEWEB)

Recent developments in solid-state radio frequency (RF) power technologies allow for the practical consideration of RF heated plasmas for space propulsion. These technologies permit the use of any electrical power source, de-couple the power and propellant sources, and allow for the effcient use of both the propellant mass and power. Effcient use of the propellant is obtained by expelling the rocket exhaust at the highest possible velocity, which can be orders of magnitude higher than those achieved in chemical rockets. Handling the hot plasma exhaust requires the use of magnetic nozzles, and the basic physics of ion detachment from the magnetic eld is discussed. The plasma can be generated by RF using helicon waves to heat electrons. Further direct heating of the ions helps to reduce the line radiation losses, and the magnetic geometry is tailored to allow ion cyclotron resonance heating. RF eld and ion trajectory calculations are presented to give a reasonably ...

1999-09-13

119

Precise characterisation of nanochannels in track etched membranes by SAXS and SANS  

Energy Technology Data Exchange (ETDEWEB)

Poster session: Abstract is full text. Track membranes are thin polymer foils irradiated by heavy ions. The defects created by the heavy ions are located along the ions trajectory, the track. It is possible to open channels by etching with a chemical agent. These channels are very uniform. Small Angle Scattering (of X rays and neutrons) give global information about the characteristics of the channel shape. As the nanochannels are strictly parallel, an excellent sample orientation is required to obtain interpretable spectra. Then shoulders due to the oscillations of the Bessel function (radial part of the channel shape Fourier transform) are easily seen in the scattered intensity in the PXY data treatment software of SAS spectra allow to determine the channel diameter with its dispersion law, to demonstrate the existence of a wall thickness with a linearly varying density, and to assess the roughness. PXY can also detect non cylindric shapes like single or double ...

2003-05-01

120

Numerical calculations on flow and behavior of pulverized coal and ash particles in 2-stage entrained-flow gasifier  

Energy Technology Data Exchange (ETDEWEB)

Flow fields, temperature distributions, and particle trajectories in a 2-stage entrained-flow gasifier are calculated using a CFD code, FLUENT. Realizable k- {epsilon} model is used as a turbulent model. Because of swirling flow there appear recirculation regions near the burners. The characteristics of flow fields and temperature distributions in the gasifier are dependent on the swirl number of the system. Mean residence time of the particles in the reductor is inversely proportional to particle size, particle density and swirl number. As the swirl number is increasing, the particles injected from the combustor burners approach the wall near the combustor burners, which prevents the particles from entering the reductor and thus attaching the reductor wall. If the lower combustor burner angle is larger than the higher combustor burner angle for a given swirl number, the particles may move toward the reductor and cause ash/slag deposition problem. (author). 19 ...

2001-07-01

121

Motor Proteins Have Highly Correlated Brownian Engines  

CERN Document Server

Two headed motor proteins, such as kinesin and dynein, hidrolyze environmental ATP in order to propel unidirectionally along cytoskeletal filaments such as microtubules. In the case of kinesin, protein heads bind primarily on the alpha tubulin site of asymmetric alpha-beta 8nm-long tubulin dimers that constitute the microtubular protofilaments. Kinesin dimers overcome local binding forces up to 5pN and are known to move on protofilaments with ATP concentration-dependent speeds while hydrolizing on average one ATP molecule per 8nm step. The salient features of protein trajectories are the distinct abrupt usually 8nm-long steps from one tubulin dimer to the next interlaced with long quiescent binding periods at a tubulin site. Discrete walks of this type are characterized by substantially reduced variances compared to pure biased random walks, and as a result rule out flashing-type ratchet models as possible mechanisms for motor movement. On the other hand, simple ...

1998-01-01

122

Magnetic Fields in Massive Stars. II. The Buoyant Rise of Magnetic Flux Tubes Through the Radiative Interior  

CERN Document Server

We present results from an investigation of the dynamical behavior of buoyant magnetic flux rings in the radiative interior of a uniformly rotating early-type star. Our physical model describes a thin, axisymmetric, toroidal flux tube that is released from the outer boundary of the convective core, and is acted upon by buoyant, centrifugal, Coriolis, magnetic tension, and aerodynamic drag forces. We find that rings emitted in the equatorial plane can attain a stationary equilibrium state that is stable with respect to small displacements in radius, but is unstable when perturbed in the meridional direction. Rings emitted at other latitudes travel toward the surface along trajectories that largely parallel the rotation axis of the star. Over much of the ascent, the instantaneous rise speed is determined by the rate of heating by the absorption of radiation that diffuses into the tube from the external medium. Since the time scale for this heating varies like the ...

2003-01-01

123

Investigation of natural circulation two-phase flow behaviour in header manifold using CFD code  

Energy Technology Data Exchange (ETDEWEB)

The three-dimensional (3-D), multiphase, computational fluid dynamic (CFD) code FLUENT is used to simulated two-phase flow behaviour in a CANDU header manifold under low (natural circulation) flow conditions. This behaviour was previously inferred from experimental data. The CFD simulations reported here are being used to support these inferences and to obtain a better understanding of phase distribution in the header manifold. The simulations seem to show that the vapor-water mixture models in the FLUENT code do not capture properly phase separation in the header and proper phase branching at the header-feeder connections that have been observed in experiments at low flows. The simulations using discrete-phase model in FLUENT, which tracks the pathlines of the individual vapor bubbles in the water continuum phase, show interesting, complicated and, in some cases, unexpected bubble trajectories from the point of injection of the bubbles at a feeder connection to ...

2006-07-01

124

Hemispheres-in-cell geometry to predict colloid deposition in porous media.  

Science.gov (United States)

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

2009-11-15

125

Global and trajectory attractors for a nonlocal Cahn-Hilliard-Navier-Stokes system  

CERN Document Server

The Cahn-Hilliard-Navier-Stokes system is based on a well-known diffuse interface model and describes the evolution of an incompressible isothermal mixture of binary fluids. A nonlocal variant consists of the Navier-Stokes equations suitably coupled with a nonlocal Cahn-Hilliard equation. The authors, jointly with P. Colli, have already proven the existence of a global weak solution to a nonlocal Cahn-Hilliard-Navier-Stokes system subject to no-slip and no-flux boundary conditions. Uniqueness is still an open issue even in dimension two. However, in this case, the energy identity holds. This property is exploited here to define, following J.M. Ball's approach, a generalized semiflow which has a global attractor. Through a similar argument, we can also show the existence of a (connected) global attractor for the convective nonlocal Cahn-Hilliard equation with a given velocity field, even in dimension three. Finally, we demonstrate that any weak solution fulfilling the energy inequality ...

2011-01-01

126

Fuel spray evolution; Comparison of experiment and CFD simulation of nonevaporating spray  

Energy Technology Data Exchange (ETDEWEB)

Detailed spray characteristics were obtained for a small-capacity, pressure-swirl atomizer using an Aerometrics phase-Doppler particle analyzer. Measurements included drop size and velocity distributions, liquid volume fluxes, and air velocities at four axial locations, 25,50,75, and 100 mm, with complete radial traverses at each location. Drop size results were compared with measurements from a Malvern laser-diffraction instrument, and integrated liquid volume fluxes were compared with measured flow rates to estimate measurement uncertainties. Drop sizes measured by the two independent techniques and area-weighted-averaged over the radial traverses at each of the four axial stations varied on average by less than 4 percent. Integrated volume flux measurements by the phase-Doppler instrument at four axial stations differed from the nozzle flow rate by at most 19 percent, with some of the difference due to evaporation. The phase-Doppler data were used to begin an evaluation of ...

1989-01-01

127

Direct energy conversion for IEC fusion for space applications  

Energy Technology Data Exchange (ETDEWEB)

The paper describes a concept of extracting fusion power from D-{sup 3}He fueled IEC (Inertia Electrostatic Configuration) devices. The fusion system consists of a series of fusion modules and direct energy converters at an end or at both ends. This system of multiple units is linear and is connected by a magnetic field. A pair of coils anti-parallel to the magnetic field yields a field-null domain at the center of each unit as required for IEC operation. A stabilizing coil installed between the coil pairs eliminates the strong attractive force between the anti-parallel coils. Accessible regions for charged particle trajectories are essentially isolated from the coil structure. Thus, charged particles are directed along magnetic field lines to the direct energy converter without appreciable losses. A direct energy converter unit designed to be compatible to this unique system is also described. It basically consists of a separator and a traveling wave converter. A ...

2000-08-01

128

Beam stabilization in SPring-8 linac for top-up injections into storage rings  

International Nuclear Information System (INIS)

The SPring-8 linac has been improved to realize stable top-up injection into the SPring-8 and the NewSUBARU storage rings. The beam energy instability of 0.02% rms in the long term was achieved by means of reducing RF variations, providing beam energy compensation, reinforcement of monitor systems and introduction of beam feedback controls: Variations in the RF power and phase have been reduced by improving the voltage regulation system for the klystron modulator, and by stabilizing the temperature drift of the atmosphere and cooling water in order to reduce the phase variation. A new synchronous oscillator synchronizes a beam trigger pulse and a 2856 MHz reference signal, reducing variation in the beam charge. A beam energy compression system (ECS) was installed to compensate for accidental energy variation and reduce the energy spread. Beam feedback controls compensate for residual long-term variations of beam trajectory and energy. (author)

2006-03-01

129

Backward pion photoproduction  

Energy Technology Data Exchange (ETDEWEB)

We present a systematic analysis of backward pion photoproduction for the reactions {gamma}p{yields}{pi}{sup 0}p and {gamma}p{yields}{pi}{sup +}n. Regge phenomenology is applied at invariant collision energies above 3GeV in order to fix the reaction amplitude. A comparision with older data on {pi}{sup 0}- and {pi}{sup +}-photoproduction at {theta}=180 indicates that the high-energy limit as given by the Regge calculation could be reached possibly at energies of around {radical}(s){approx_equal}3 GeV. In the energy region of {radical}(s){<=}2.5 GeV, covered by the new measurements of {gamma}p{yields}{pi}{sup 0} p differential cross-sections at large angles at ELSA, JLab, and LEPS, we see no clear signal for a convergence towards the Regge results. The baryon trajectories obtained in our analysis are in good agreement with those given by the spectrum of excited baryons. (orig.)

2009-04-15

130

Air liquefaction and enrichment system propulsion in reusable launch vehicles  

Energy Technology Data Exchange (ETDEWEB)

A concept is shown for a fully reusable, Earth-to-orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high-speed acceleration, both using liquid hydrogen for fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90% pure liquid oxygen as its oxidizer that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. This article shows an approach and the corresponding technology needs for using air liquefaction and enrichment system propulsion in a single-stage-to-orbit (SSTO) vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, in a direct substitution for ...

1994-07-01

131

A new direct calculation method of response matrices using a Monte Carlo calculation  

Energy Technology Data Exchange (ETDEWEB)

A novel direct calculation method of response matrices on heterogeneous lattices by using the Monte Carlo method is proposed. These direct response matrices (DRMs) can be used in core calculations in place of the conventional homogenized lattice constants. The DRMs are formalized by four sub response matrices (sub-RMs) in order to respond to a core eigenvalue, k; thus the DRMs can be re-evaluated on each outer iteration in the core calculations. The sub-RMs can be evaluated by analyzing each neutron's trajectory from ordinary lattice calculations with the Monte Carlo code. Since these sub-RMs are calculated directly under an actual complex assembly geometry, i,e., without a homogenization process, intra-assembly heterogeneous effects can be reflected on global partial current balance calculations. With using two of the sub-RMs, which deal with neutron production probabilities for each fuel pin, and the obtained partial current balance, pin-wise neutron ...

1999-10-01

132

A combined cycle engine test facility  

Energy Technology Data Exchange (ETDEWEB)

Rocket-Based Combined-Cycle (RBCC) engines intended for missiles and/or space launch applications incorporate features of rocket propulsion systems operating in concert with airbreathing engine cycles. Performance evaluation of these types of engines, which are intended to operate from static sea level take-off to supersonic cruise or accerlerate to orbit, requires ground test capabilities which integrate rocket component testing with airbreathing engine testing. A combined cycle engine test facility has been constructed in the General Applied Science Laboratories, Inc. (GASL) Aeropropulsion Test Laboratory to meet this requirement. The facility was designed to support the development of an innovative combined cycle engine concept which features a rocket based ramjet combustor. The test requirements included the ability to conduct tests in which the propulsive force was generated by rocket only, the ramjet only and simultaneous rocket and ramjet power (combined cycle) to evaluate ...

1995-09-01

133

A Bragg curve counter with an internal production target for the measurement of the double-differential cross-section of fragment production induced by neutrons at energies of tens of MeV  

Energy Technology Data Exchange (ETDEWEB)

A Bragg curve counter equipped with an internal production target was developed for the measurements of double-differential cross-sections of fragment production induced by neutrons at energies of tens of MeV. The internal target permitted a large detection solid angle and thus the registration of processes at low production rates. In this specific geometry, the detection solid angle depends on the emission angle and the range of the particle. Therefore the energy, atomic number, and angle of trajectory of the particle have to be taken into account for the determination of the solid angle. For the selection of events with tracks confined within a defined cylindrical volume around the detector axis, a segmented anode was applied. The double-differential cross-sections for neutron-induced production of lithium, beryllium, and boron fragments from a carbon target were measured at 0 deg. for 65 MeV neutrons. The results are in good agreement with theoretical ...

2009-11-11

134

Zero-G two phase flow regime modeling in adiabatic flow  

Energy Technology Data Exchange (ETDEWEB)

Two-phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitions, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two-phase systems. This work is concerned with microgravity, two-phase flow regime analysis. The data come from a recent sets of experiments. The experiments were funded by NASA Johnson Space Center (JSC) and conducted by NASA JSC with Texas A M University. The experiment was on loan to NASA JSC from Foster-Miller, Inc., who constructed it with funding from the Air Force Phillips Laboratory. The experiment used R12 as the working fluid. A Foster-Miller two phase pump was used to circulate the two phase mixture and allow separate measurements of the vapor and liquid flow streams. The experimental package ...

1993-01-15

135

Zero-G two phase flow regime modeling in adiabatic flow  

International Nuclear Information System (INIS)

Two-phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitions, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two-phase systems. This work is concerned with microgravity, two-phase flow regime analysis. The data come from a recent sets of experiments. The experiments were funded by NASA Johnson Space Center (JSC) and conducted by NASA JSC with Texas A ampersand M University. The experiment was on loan to NASA JSC from Foster-Miller, Inc., who constructed it with funding from the Air Force Phillips Laboratory. The experiment used R12 as the working fluid. A Foster-Miller two phase pump was used to circulate the two phase mixture and allow separate measurements of the vapor and liquid flow streams. The experimental ...

1993-01-10

136

The China Clipper - fast advective transport of radon-rich air from the Asian boundary layer to the upper troposphere near California  

Energy Technology Data Exchange (ETDEWEB)

A series of upper tropospheric radon concentration measurements made over the eastern Pacific and west coast of the United States during the summers of 1983 and 1984 has revealed the occurrence of unexpectedly high (>16 pCi/SCM) radon concentrations for 9 of the 61 measurements (and 6 of the 13 flights). A frequency distribution plot of the set of 61 observations shows a distinct bimodal distribution, with approximately 2/5 of the observations falling close to 1 pCi/SCM, and 3/5 falling in a high concentration mode centered at about 11 pCi/SCM. Trajectory and synoptic analyses for two of the flights on which such high radon concentrations were observed indicate that this radon-rich air originated in the Asian boundary layer, ascended in cumulus updrafts, and was carried eastward in the fast moving air on the anti-cyclonic side of the upper tropospheric jet. Transit times were of the order of 3 days; however, in one instance, transport from China to a point a few ...

1990-02-01

137

Strong ionizing events distributed along medium energy #alpha# particle tracks recorded in nuclear emulsion  

International Nuclear Information System (INIS)

Track analysis of medium energy #alpha# particle trajectories recorded in fine grain nuclear emulsion submitted to specific intensifying treatments led to the observation of strong ionizing events (SIE) sticking out of the primary's track core. Preliminary determinations showed that the number of SIEs increases with the primary's energy, and that their production is of more than one order of magnitude higher than the number of Rutherford recoils. The presence of SIEs on monoenergetic #alpha# tracks also has a significant influence on the measured range distribution, which, expressed in terms of energy loss, results in a mean contribution to the total energy loss of far reaching (SIEs (radial spread >= 0.458 #mu#m) of proportional 25 keV per 13.6 MeV #alpha# particle, instead of 0.75 keV in the case where only the Rutherford interactions are taken into account. Measurements carried out in detectors enriched with gelatin indicate an increase in the number of SIEs ...

138

Statistical description and estimation of ocean drift ice environments  

Energy Technology Data Exchange (ETDEWEB)

Part I of this thesis is on long-term iceberg collision-risk assessment methods for fixed offshore structures. Estimates for the long-term probability that an iceberg will hit a fixed offshore structure are based on estimates of the total volume of produced iceberg, a model for the size distribution of icebergs and a description of how iceberg trajectories ``fill`` the plane (the ocean`s surface). Part II of the thesis discusses methods for analysis of low resolution data in the sense that the size of the area covered by each pixel is not small compared to the dominating floes. Still, this type of data can provide estimates of the ice extent (and hence the ice edge) and ice concentration. The estimates of the ice edge (at least) seem to be physically significant in the sense that ``in some way`` they can reflect ice drift in an image time sequence. A priori this is far from obvious. A central idea is that the ``ice edge`` is close to a transition zone between two ...

1991-04-01

139

Scaling method for fast Monte Carlo simulation of diffuse reflectance spectra from multilayered turbid media  

Science.gov (United States)

A scaling Monte Carlo method has been developed to calculate diffuse reflectance from multilayered media with a wide range of optical properties in the ultraviolet-visible wavelength range. This multilayered scaling method employs the photon trajectory information generated from a single baseline Monte Carlo simulation of a homogeneous medium to scale the exit distance and exit weight of photons for a new set of optical properties in the multilayered medium. The scaling method is particularly suited to simulating diffuse reflectance spectra or creating a Monte Carlo database to extract optical properties of layered media, both of which are demonstrated in this paper. Particularly, it was found that the root-mean-square error (RMSE) between scaled diffuse reflectance, for which the anisotropy factor and refractive index in the baseline simulation were, respectively, 0.9 and 1.338, and independently simulated diffuse reflectance was less than or equal to 5% for ...

2007-04-01

140

Make Markets Work for Climate. Background Document  

Energy Technology Data Exchange (ETDEWEB)

Climate change is no longer questioned. Meeting growing global energy needs - while limiting the rate of climate change over the long term - will require both developed and developing countries to move to fuels with lower emissions of greenhouse gases and to adopt more energy-efficient technologies. Investment decisions made today will be pivotal in determining the path of global energy consumption for decades to come. Energy markets, financial markets, and the markets in which greenhouse gas emissions are traded - the so-called 'carbon markets' - together determine which technologies are adopted, and how quickly. Over the next half-century, energy demand will grow almost four times as rapidly in developing countries as in developed countries. Consequently, finding ways to increase investment in cleaner energy technologies in rapidly-growing economies in the developing world will be an essential component of global efforts to alter the path of greenhouse gas ...

2006-07-01

141

INTERACTING BINARIES WITH ECCENTRIC ORBITS. III. ORBITAL EVOLUTION DUE TO DIRECT IMPACT AND SELF-ACCRETION  

International Nuclear Information System (INIS)

The rapid circularization and synchronization of the stellar components in an eccentric binary system at the onset of Roche lobe overflow is a fundamental assumption common to all binary stellar evolution and population synthesis codes, even though the validity of this assumption is questionable both theoretically and observationally. Here we calculate the evolution of the orbital elements of an eccentric binary through the direct three-body integration of a massive particle ejected through the inner Lagrangian point of the donor star at periastron. The trajectory of this particle leads to three possible outcomes: direct accretion onto the companion star within a single orbit, self-accretion back onto the donor star within a single orbit, or a quasi-periodic orbit around the companion star, possibly leading to the formation of a disk. We calculate the secular evolution of the binary orbit in the first two cases and conclude that direct impact accretion can increase ...

2010-11-20

142

Heavy fuel oil combustion in a cylindrical laboratory furnace: measurements and modeling  

Energy Technology Data Exchange (ETDEWEB)

The finite-volume based commercial CFD-code Fluent was used to simulate the reacting flow in a heavy fuel oil fired laboratory furnace. Both the standard {kappa}-{epsilon} turbulence model and the Reynolds stress model (RSM) were tested. The combustion model was based on the conserved scalar (mixture fraction) and prescribed probability density function approach. The heavy fuel oil droplet trajectories were predicted by solving the momentum equations for the droplets using the Lagrangian treatment. The soot distribution in the furnace was calculated by solving a transport equation for the soot mass fraction. Simple expressions for the soot formation and oxidation rates were employed. The radiation heat transfer equation was solved using the finite volume method. The formation of thermal NO from molecular nitrogen was modeled according to the extended Zeldovich mechanism. Fuel-based NO was modeled assuming that all the nitrogen in the fuel is released as hydrogen ...

2005-03-01

143

Greater Green River Basin production improvement project, Phase 1: Site characterization report  

Energy Technology Data Exchange (ETDEWEB)

Several tight, naturally-fractured, gas-productive formations in the Greater Green River Basin (GGRB) in Wyoming have been exploited using conventional vertical well technology. Typically, hydraulic fracture treatments must be performed in completing these wells to increase gas production rates to economic levels. However, with the maturation of horizontal drilling technology hydraulic fracture treatments may not be the most effective method for improving gas production from these tight reservoirs. Two of the most prolific tight gas reservoirs in the Green River Basin, the Frontier and the Mesaverde, are candidates for the application of horizontal well completion technology. The objective of the proposed project is to apply the DOE`s technical concept to the Second Frontier Formation on the western flank of the Rock Springs Uplift. Previous industry attempts to produce in commercial quantities from the Second Frontier Formation have been hampered by lack of understanding of both the ...

1996-05-01

144

General-purpose heat source development: Extended series test program SRB fragment/fuselage tests  

Energy Technology Data Exchange (ETDEWEB)

General-Purpose Heat Source radioisotope thermoelectric generators (GPHS-RTGs) will provide electrical power for the NASA Galileo and European Space Agency (ESA) Ulysses missions. Each GPHS-RTG comprises two major components: GPHS modules, which provide thermal energy, and a thermoelectric converter, which converts the thermal energy into electrical power. Each of the 18 GPHS modules in a GPHS-RTG contains four /sup 238/PuO/sub 2/-fueled capsules. LANL conducted a series of safety verification tests on the GPHS-RTG before the scheduled May 1986 launch of the Galileo spacecraft to assess the ability of the GPHS modules to contain plutonia in potential accident environments. As a result of the Challenger 51-L accident in January 1986, NASA postponed the launch of Galileo; the spacecraft launch vehicle was reconfigured and the spacecraft trajectory modified. These actions prompted NASA to reevaluate potential mission accidents and the extended series safety test ...

1989-06-01

145

Fifty years of jet in cross flow research  

Science.gov (United States)

The jet in cross flow (JICF) is a basic flowfield which is relevant to a wide variety of applications which are described to provide context for JICF investigations. Material consistent with the scope of topics presented at the 72nd AGARD Fluid Dynamics Panel Meeting and Symposium on Computational and Experimental Assessment of Jets in Cross Flow on 19-22 April 1993 in Winchester, U.K. is summarized. The JICF research was divided into three time periods: (1) early research - up to 1970, (2) research during the 1970's, and (3) research since 1980. The following areas of experimental activity are discussed; the definition of an effective correlation parameter; the jet flowfield including the jet trajectories, cross-section shape, and jet induced pressures; the effects of jet deflection angle, nozzle shape, pressure ratio, velocity decay, and temperature; and the effect of confined flowfield, ground effects, multiple jets, and adjacent surface geometry. In addition, ...

1993-11-01

146

Decoherence, chaos, quantum-classical correspondence and the arrow of time  

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 bit more then ...

1998-12-01

147

Basics of Ion Scattering in Nanoscale Materials  

Science.gov (United States)

Energetic ions interact with materials by collisions with the nuclei and electrons of the atoms that make up the material. In these collisions energy and momentum is transferred from the projectile particle which is a moving atom or ion, to the target particles (atomic nucleus or electron). Each collision leads to a slowing down of the moving projectile and also a deflection of the trajectory which gives rise to the term scattering which is often used synonymously to describe the energy transfer process. In this chapter, we introduce from an experimental viewpoint the underlying theory for interaction of ions for analysis and modification of nanometer scale materials. A more detailed theoretical overview of the topic can be found in the recent monographs by Sigmund. Detailed derivations of the formulae introduced will not be given here but can be found in standard texts that are indicated by references. The treatment here starts by considering an individual ...

2010-01-01

148

A novel method to characterize the MTF in 3D for computed mammotomography  

Science.gov (United States)

A novel phantom has been developed to measure the modulation transfer function (MTF) in 3D for x-ray computed tomography. The phantom consists of three tungsten wires, positioned nearly orthogonal to each other. Simultaneous measurements of the MTF are taken at various locations along the three orthogonal reconstructed planes. Our computed mammotomography (CmT) system uses a Varian Paxscan 2520 digital x-ray detector which can be positioned anywhere in ~2pi steradian band and can have arbitrary trajectories. With a half-cone beam geometry and with the phantom positioned near the center of rotation, projection images are acquired over 360 degrees. Various 3D orbits are evaluated including vertical axis of rotation and saddle. Reconstructions were performed using an iterative ordered-subsets transmission algorithm on rebinned projection images, using various numbers of iterations. Rotation of reconstructed slices isolated each wire into its own plane. At various ...

2006-03-01

149

Validation of the GROMOS force-field parameter set 45A3 against nuclear magnetic resonance data of hen egg lysozyme  

Energy Technology Data Exchange (ETDEWEB)

The quality of molecular dynamics (MD) simulations of proteins depends critically on the biomolecular force field that is used. Such force fields are defined by force-field parameter sets, which are generally determined and improved through calibration of properties of small molecules against experimental or theoretical data. By application to large molecules such as proteins, a new force-field parameter set can be validated. We report two 3.5 ns molecular dynamics simulations of hen egg white lysozyme in water applying the widely used GROMOS force-field parameter set 43A1 and a new set 45A3. The two MD ensembles are evaluated against NMR spectroscopic data NOE atom-atom distance bounds, {sup 3}J{sub NH{alpha}} and {sup 3}J{sub {alpha}}{sub {beta}} coupling constants, and {sup 1}5N relaxation data. It is shown that the two sets reproduce structural properties about equally well. The 45A3 ensemble fulfills the atom-atom distance bounds derived from NMR spectroscopy slightly less well ...

2004-12-15

150

A stochastic convolution/superposition method with isocenter sampling to evaluate intrafraction motion effects in IMRT  

International Nuclear Information System (INIS)

Current methods to calculate dose distributions with organ motion can be broadly classified as 'dose convolution' and 'fluence convolution' methods. In the former, a static dose distribution is convolved with the probability distribution function (PDF) that characterizes the motion. However, artifacts are produced near the surface and around inhomogeneities because the method assumes shift invariance. Fluence convolution avoids these artifacts by convolving the PDF with the incident fluence instead of the patient dose. In this paper we present an alternative method that improves the accuracy, generality as well as the speed of dose calculation with organ motion. The algorithm starts by sampling an isocenter point from a parametrically defined space curve corresponding to the patient-specific motion trajectory. Then a photon is sampled in the linac head and propagated through the three-dimensional (3-D) collimator structure corresponding to a particular MLC segment ...

2005-04-01

158
160

The study of antiprotons and positrons in cosmic rays with the PAMELA spectrometer  

CERN Document Server

The study of antiprotons and positrons in cosmic rays with the PAMELA spectrometer

1998-01-01

161

Studies on the Permeability to Lipids and Lipoproteins of ...  

Science.gov (United States)

... Accession Number : AD0769178. Title : Studies on the Permeability to Lipids and Lipoproteins of Inflamed Skin Capillaries,. ...

162

ELECTRON MICROSCOPE STUDIES INTO THE ...  

Science.gov (United States)

ELECTRON MICROSCOPE STUDIES INTO THE MORPHOLOGY AND LOCALIZATION OF OMSK HEMORRHAGIC FEVER VIRUS IN INFECTED ...

1966-08-01

164

In vivo range of motion of the lumbar spinous processes  

UK PubMed Central (United Kingdom)

The study design included an in vivo laboratory study. The objective of the study is to quantify the kinematics of the lumbar spinous processes in asymptomatic patients during un-restricted functional...Full Text Available

2009-09-01

175

Study of Tibial Shaft Fractures in Children  

Science.gov (United States)

Tibial Shaft Fractures in Children

2010-11-09

193

Gestational Diabetes Follow Up Study  

Science.gov (United States)

Diabetes, Gestational; Postpartum Period

2009-10-19

201

Corrosion and histopathological studies on anode materials for implantable power sources. [In vivo corrosion studies on anode material  

Science.gov (United States)

The biocompatibility and corrosion resistance of various materials for use as sacrificial anodes in in vivo hybrid fuel cells were studied. Aluminium, zinc, and magnesium alloy AZ31B were studied, and the results are discussed.

1974-01-01

224

Mathematical Modeling and Optimization Studies on ...  

Science.gov (United States)

... 1]. Results and Discussion A cross section of liquid feed direct borohydride fuel cell model was created and studied. The ...

2010-05-12

226

A Study of the Geographic Origin, Education, and Experience ...  

Science.gov (United States)

... by starting and remaining in that size hotel. Another early study, conducted by Nailon (1968) sampled three general managers ...

1993-04-01

227

The use of healthy volunteers instead of patients to inform drug dosing studies: a [11C]raclopride PET study  

British Library Electronic Table of Contents (United Kingdom)

Rationale Receptor occupancy study has been performed to evaluate pharmacokinetic profiles in new antipsychotic drug development. While these findings highlight the value of positron emission tomography (PET) for dose-finding study, what is unclear is if it is necessary to conduct these studies in patients with schizophrenia or whether studies in healthy volunteers are adequate. Objectives To determine if it is necessary to conduct dopamine receptor occupancy studies in patients with schizophrenia or whether studies in healthy volunteers are adequate for dose-finding study, we compared the concentration?occupancy relationship in terms of EC50 between patients and healthy volunteers. Methods Ten healthy volunteers and eight patients with schizophrenia participated in the study. We measured ...

2011-01-01

228

Methodological Quality of Studies on the Measurement Properties of Neck Pain and Disability Questionnaires: A Systematic Review  

British Library Electronic Table of Contents (United Kingdom)

Objective: The aim of this study was to obtain an overview of the methodological quality of studies on the measurement properties of neck pain and disability questionnaires and to describe how well various aspects of the design and statistical analyses of studies on measurement properties are performed. Methods: A systematic review was performed of published studies on the measurement properties of neck pain and disability questionnaires. Two reviewers independently rated the quality of the studies using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. This checklist was developed in an international Delphi consensus study. Results: A total of 47 articles were included on the measurement properties of 8 different questionnaires. The meth...

2011-01-01

229

(Feasibility study of the San Lorenzo River hydroelectric project)  

Science.gov (United States)

I travelled to San Jose, Costa Rica on July 8, 1990 to evaluate all of the completed elements of the ongoing feasibility study for the San Lorenzo River hydroelectric project. The feasibility study is being supported by ORNL under the Renewable Energy Applications and Training Project. The project is being studied for implementation by CONELECTRICAS, a consortium of rural electric cooperatives and the study itself is being conducted by BEL Engineering, a Costa Rican consulting firm under contract to CONELECTRICAS, USAID/PIC and NRECA.

1990-07-19

230

Using microarrays to identify positional candidate genes for QTL: the case study of ACTH response in pigs  

UK PubMed Central (United Kingdom)

BackgroundMicroarray studies can supplement QTL studies by suggesting potential candidate genes in the QTL regions, which by themselves are too large to provide a limited selection...Full Text Available

231

Using Geographic Information Systems for Exposure Assessment in Environmental Epidemiology Studies  

UK PubMed Central (United Kingdom)

Geographic information systems (GIS) are being used with increasing frequency in environmental epidemiology studies. Reported applications include locating the study population by geocoding addresses...Full Text Available

2004-06-01

232

Toxicity and carcinogenicity studies of boric acid in male and female B6C3F1 mice.  

UK PubMed Central (United Kingdom)

Toxicity and potential carcinogenicity studies of boric acid were investigated in mice to verify in a second rodent species that this was a noncarcinogenic chemical. Earlier chronic studies in rats...Full Text Available

1994-11-01

233

Theoretical Study of Tautomerization Reactions for the Ground and First Excited Electronic States of Adenine.  

Science.gov (United States)

Geometrical structures and energetic properties for different tautomers of adenine are calculated in this study, using multi-configurational wave functions. Both the ground and the lowest singlet excited state potential energy surfaces are studied. Four t...

2002-01-01

234

The Comprehensive Dialysis Study (CDS): A USRDS Special Study  

UK PubMed Central (United Kingdom)

Background and objectives: The Comprehensive Dialysis Study (CDS) aimed to understand factors contributing to physical, functional, and nutritional health status among patients starting dialysis.Design,...Full Text Available

2009-03-01

235

Study protocol. A prospective cohort study of unselected primiparous women: the pregnancy outcome prediction study  

UK PubMed Central (United Kingdom)

BackgroundThere have been dramatic changes in the approach to screening for aneuploidy over the last 20 years. However, the approach to screening for other complications of pregnancy...Full Text Available

236

Socio-demographic disparity in oral health among the poor: a cross sectional study of early adolescents in Kilwa district, Tanzania  

UK PubMed Central (United Kingdom)

BackgroundThere is a lack of studies considering social disparity in oral health emanating from adolescents in low-income countries. This study aimed to assess socio-demographic...Full Text Available

237

Prevalence of Ocular Fundus Pathology in Patients with Chronic Kidney Disease  

UK PubMed Central (United Kingdom)

Background and objectives: The objective of this study was to describe the prevalence of ocular fundus pathology in the Chronic Renal Insufficiency Cohort (CRIC) study, a multicenter, longitudinal study...Full Text Available

2010-05-01

238

Multicenter Case-Control Study on Restless Legs Syndrome in Multiple Sclerosis: the REMS Study  

UK PubMed Central (United Kingdom)

Study objectives:To verify the existence of a symptomatic form of restless legs syndrome (RLS) secondary to multiple sclerosis (MS) and to identify possible associated risk factors.Design:Prospective,...Full Text Available

2008-07-01

239

Most Antidepressant Use in Primary Care Is Justified; Results of the Netherlands Study of Depression and Anxiety  

UK PubMed Central (United Kingdom)

BackgroundDepression is a common illness, often treated in primary care. Many studies have reported undertreatment with antidepressants in primary care. Recently, some studies also...Full Text Available

240

Molecular and clinico-pathological markers in rectal cancer: a tissue micro-array study  

UK PubMed Central (United Kingdom)

AimsThe aims of the study were to study the effect of pre-operative treatment on the expression of tumour-related proteins and to correlate the expression of these...Full Text Available

2009-02-01

241

Measuring quality of care in psychiatric emergencies: construction and evaluation of a Bayesian index.  

UK PubMed Central (United Kingdom)

OBJECTIVE. This study was conducted to determine whether an index for measuring quality of care for psychiatric emergencies is reliable and valid. DATA SOURCES/STUDY SETTING. The study used primary...Full Text Available

1993-06-01

242

Gender differences in disability after sickness absence with musculoskeletal disorders: five-year prospective study of 37,942 women and 26,307 men  

UK PubMed Central (United Kingdom)

BackgroundGender differences in the prevalence and occupational consequences of musculoskeletal disorders (MSDs) are consistently found in epidemiological studies. The study investigated...Full Text Available

243

Exposure to dioxin and nonneoplastic mortality in the expanded IARC international cohort study of phenoxy herbicide and chlorophenol production workers and sprayers.  

UK PubMed Central (United Kingdom)

The authors studied noncancer mortality among phenoxyacid herbicide and chlorophenol production workers and sprayers included in an international study comprising 36 cohorts from 12 countries followed...Full Text Available

1998-04-01

244

Electrophysiological Study and Catheter Ablation with 3D Mapping  

Medline Plus

... see and electrophysiological study and catheter ablation with 3D mapping. During the procedure, doctors look at the ... perform a electrophysiology study with ablation, using our 3D mapping system. Keep in mind, that during the ...

245

Dietary factors related to body weight in adult Vietnamese in the rural area of Haiphong, Vietnam: the Korean Genome and Epidemiology Study (KoGES)  

UK PubMed Central (United Kingdom)

The objectives of this study were to examine the association between dietary factors and underweight and overweight adult Vietnamese living in the rural areas of Vietnam. A cross-sectional study of...Full Text Available

2010-06-01

246

Design and Operating Parameters for Emission Control Studies: ASARCO, El Paso, Copper Smelter.  

Science.gov (United States)

The report gives background design data for a specific copper smelter. The data is sufficiently detailed to allow air pollution control system engineering studies to be conducted. These studies will be concerned primarily with lean SO2 streams that curren...

1976-01-01

247

A critical review of studies of the association between demands for hospital services and air pollution.  

UK PubMed Central (United Kingdom)

Studies of the associations between air pollution and hospital admissions and emergency room use are reviewed, including studies of air pollution episodes, time-series analyses, and cross-sectional...Full Text Available

1993-07-01

248

The implications of tolerance system interpretation on past and present dimensional variability studies  

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.

1994-12-31

249

Conditional risk assessment of SNR 300 in case of an unprotected loss of flow accident  

International Nuclear Information System (INIS)

This paper gives a summary of a risk study assuming unprotected loss of flow (ULOF) in the SNR 300. This study was initiated in 1979/80 by the Karlsruhe Nuclear Research Center and performed in close cooperation with Science Applications Inc., Palo Alto, USA, and Interatom Company. Part of the results also was integrated in the 'Risk Related Analysis for the SNR 300' carried out by the Gesellschaft fuer Reactorsicherheit. The character of the study described here is similar to other risk studies like the Reactor Safety Study and the German Risk Study for Nuclear Power Plants. The objectives and the methodology of the analyses are described and its results are discussed. (orig./RW).

250

Chernobyl Studies Project. Working Group 7.0, environmental transport and health effects. Progress report, February 1994  

Energy Technology Data Exchange (ETDEWEB)

The focus of the Chernobyl Studies Project has now turned to the issue of health effects from the Chernobyl accident. Currently, we are involved in and making progress on the case-control and co-hort studies of thyroid diseases among Belarussian children. Dosimetric aspects are a fundamental part of these studies. We are working to implement similar studies in Ukraine. A major part of the effort of these projects is supporting these studies, both by providing methods and applications of dose reconstruction and by providing support and equipment for the medical teams.

1994-04-01

251

Study of the Electron Beam Dynamics in the Fermi @ Elettra Linac  

Energy Technology Data Exchange (ETDEWEB)

A study of the electron beam dynamics in the linac is conducted for the FERMI free electron laser (FEL) founded for construction at the Sincrotrone Trieste.

2006-07-19

252

Study of the Electron Beam Dynamics in the FERMI @ ELETTRALinac  

Energy Technology Data Exchange (ETDEWEB)

A study of the electron beam dynamics in the linac is conducted for the FERMI free electron laser (FEL) founded for construction at the Sincrotrone Trieste

2006-06-17

253

Studies for the Synthesis of Xenicane Diterpenes. A Stereocontrolled Total Synthesis of 4-Hydroxydictyolactone  

UK PubMed Central (United Kingdom)

The stereocontrolled total synthesis of 4-hydroxydictyolactone (4), a member of the xenicane diterpene family of natural products, is described. These studies feature the development...Full Text Available

2009-07-01

254

Prognostic Factors for Failure after Prostatectomy  

UK PubMed Central (United Kingdom)

Several randomized studies have been completed in prostate cancer that show a benefit to immediate postoperative treatment in patients undergoing prostatectomy. In one of the studies, there was even...Full Text Available

255

Prediction accuracy of a sample-size estimation method for ROC studies  

UK PubMed Central (United Kingdom)

Rationale and ObjectivesSample-size estimation is an important consideration when planning a receiver operating characteristic (ROC) study. The aim of this work was...Full Text Available

2010-05-01

256

Periodontal disease and spontaneous preterm birth: a case control study  

UK PubMed Central (United Kingdom)

BackgroundSeveral studies have suggested an association between periodontal disease and prematurity but this finding has not been consistently observed.MethodsCase...Full Text Available

257

Packaging, Storage, and Containerization Center: Reports ...  

Science.gov (United States)

... 9 SIMPLIFICATION STUDY RECOMMENDATIONS - MIL-STD-2073-1/2 ... SIMPLIFICATION STUDY RECOMMENDATIONS - MIL-STD-2073-1/2 ...

1993-12-01

258

Lunar Geology  

Science.gov (United States)

Lunar Geology is the study of the moons crust, rocks, strata, etc. Lunar Geology tends to cover two broad areas of study; Maria (and/or Basins) and Highlands. ...

259

In-situ micro-FTIR study of thermal changes of organics in Tagish ...  

Science.gov (United States)

FT-IR spectroscopic studies of major organic matter in carbonaceous chondrites using microscopic technique and comparison with terrestrial kerogen. ...

260

If I Had - A Family Member with Metabolic Syndrome  

Medline Plus

... elevated blood sugar levels, but not full-blown diabetes. What are the keys to preventing the disease? ... been well studied, in a study called The Diabetes Prevention Program, in several thousand people with this ...

261

Fundamental study of heat transfer augmentation of tube inside surface by cascade smooth surface-turbulence promoters  

Science.gov (United States)

Fundamental study of heat transfer augmentation of tube inside surface by cascade smooth surface-turbulence promoters

1987-03-01

262

Flue gas desulfurization pilot study: summary of phase I and phase II reports  

Science.gov (United States)

The initial phase of this study consisted of a survey of existing FGD systems used on larger combustion processes in the NATO countries and Japan.

1980-04-01

263

Field studies among diverse biomes demonstrate that nitrogen ...  

Science.gov (United States)

Field studies among diverse biomes demonstrate that nitrogen concentration (% N) at leaf- and canopy-scales is strongly related to carbon uptake and cycling ...

264

Effects of phenoxybenzamine on bladder neck opening1  

UK PubMed Central (United Kingdom)

A study of the effects of the action of phenoxybenzamine on bladder neck opening during micturition is reported. Twenty patients with symptoms of prostatism but minimal prostatic enlargement were studied....Full Text Available

1980-05-01

265

ESR study in radiation damage in pyrimidines. 3-year comprehensive progress report  

International Nuclear Information System (INIS)

General mechanisms of radiation damage to biomolecules was studied by using substituted pyrimidines, particularly barbituric acid derivatives.

266

Department of the  

Wastenet

Waste Technology and Innovation Study Final Report ...Waste Technology and Innovation Study Final Report 21/18569/150554 ...Survey of waste and resource recovery related technology and innovation, including products and product uses

267

Coccygectomy with or without periosteal resection  

UK PubMed Central (United Kingdom)

The purpose of this study was to compare the clinical outcomes and wound complications in coccygectomy with or without subperiosteal resection. This retrospective study included 25 patients who underwent...Full Text Available

2010-04-01

268

Clinical Investigation Program, Reports Control Symbol MED ...  

Science.gov (United States)

... POG Cook, BA A Case Control Study of Childhood 147 8552(85) Rhabdomyosarcoma (0) POG COOK, BA Phase II Study of 6-Mercaptopurine ...

1988-10-01

269

Biomarker studies in northern Bohemia.  

UK PubMed Central (United Kingdom)

Studies were conducted in northern Bohemia to simultaneously evaluate personal exposures to air pollution in the form of respirable particles containing polycyclic aromatic hydrocarbons (PAHs) and biomarkers...Full Text Available

1996-05-01

270

Alternative fuel trucks case studies: Running line-haul trucks on ethanol  

Energy Technology Data Exchange (ETDEWEB)

This bulletin describes case studies of trucks operating on ethanol fuel. Cost, maintenance and repair, as well as fuel economy are discussed.

1996-10-01

271

Winter Air Quality Study  

Science.gov (United States)

... 15 minutes Time lapse video Time Lapse Recorder (Panasonic) SVHS 4-seconds

275

The studying of electron motion in crystal lattice by using computer  

International Nuclear Information System (INIS)

... 2007, 80 ?. 5. ?????? ?.?. Visual Basic-6.0, ??????, 2000, 449 ?. ????

2010-04-01

278

The beginning of a new science  

International Nuclear Information System (INIS)

The evolution of the study of extra-terrestrial neutrinos over the 45 years since their discovery.

281

The Application of Diffusion Approximations to the Study of ...  

Science.gov (United States)

... Descriptors : *QUEUEING THEORY, *APPROXIMATION ... MODELS, OPTIMIZATION, STOCHASTIC PROCESSES ... Categories : TERMINAL FLIGHT ...

286

Study on a limiting sensitivity of a betatron introscope  

International Nuclear Information System (INIS)

1975. USSR Zabrodskij, VA Nedavnij, SN INIS-mf--3677. Available from

1975-09-03

314

Progress in plasma research at IPJ and IPPLM, Poland  

International Nuclear Information System (INIS)

... E. The Andrzej Soltan Institute for Nuclear Studies, Otwock-Swierk (Poland)

2006-09-11

324

Magnetic forming studies  

Science.gov (United States)

Elastodynamic approach to measuring stress-strain relationship of uniaxially stressed wire, and

1967-01-01

326

Isopod Systematics and Evolution  

Science.gov (United States)

... inferences. Thatcher carries the banner for studies of isopod parasites of fishes of the Amazonian region. This fauna ... ...

331

High energy physics  

International Nuclear Information System (INIS)

The research of the CELLO collaboration is reviewed. After a description of the CELLO detector tests of QCD and hadronic final states by determination of the strong coupling constant and studies of inclusive production of electrons and muons in multihadronic events in e"+e"- annihilation are described. Then studies of deep inelastic e#gamma# scattering with lepton pair production and the study of the structure function of the photon are briefly described. Finally studies on QED processes are described together with tau decays. (HSI).

1983-11-01

334

Fundamental study on Fuji Computed Radiography (FCR) image  

International Nuclear Information System (INIS)

Japanese (Mar 1986). Japan Tomiyoshi, Tsukasa Kakoi, Iwao Fukushima,

1986-01-01

346

Environmental Economics  

Wastenet

environmental burden is studied by testing the Environmental Kuznets Curve hypothesis as well as application of statistical decomposition

349

Dynamic Study of Co-generator System Using EMTDC  

Energy Technology Data Exchange (ETDEWEB)

This paper deals with dynamic study of co-generator system with derived dynamic models of generator, excitation system, and turbine/governor from field tests. Mainly this study concentrates on frequency control by under-frequency relay. We simulates dynamic study of co-generator system using EMTDC. (author). 4 refs., 13 figs., 4 tabs.

2001-07-01

350

Diquarks in gamma-p Collisions at LHeC  

CERN Document Server

This note studies the single production of scalar or vector diquarks at the LHeC collider.

2011-01-01

361

Cell culture systems to study glial transformation  

Energy Technology Data Exchange (ETDEWEB)

The transformation of two different types of glial cells has been studied using an in vivo-/in vitro model and a complete in vitro model. The purpose of the study and to define in vitro model systems is to study the the neoplastic transformation of pure populations of glial cells. Data are presented to demonstrate that the transformed cells are glial and tumorigenic. (ACR)

1980-01-01

362

Breath Test for Chemicals (Volatile Organic Compounds)  

Science.gov (United States)

Breath Tests; Human Volunteers; Pilot Study

2011-09-16

363

Biology of lichen communities in Antarctica.  

Science.gov (United States)

-Ecophysiological and floristic study of the lichen communities in .... Plasticity of the Lichen Catillaria corymbosa in Different Microhabitats of the ...

365

BOOKMARKS:  

Wastenet

Environmental Study/Action Team (NEST), UIPO Box 22025, Ibadan, Oyo-State, Nigeria ; tel/fax: +234 (

366

BIOCHEMISTRY BRANCH ABSTRACTS  

Science.gov (United States)

... The anti-tumor drugs used for these studies were: busulfan, cyclophosphamide, metho- trexate, vinblastine and 6-mercaptopurine. ...

1968-01-01

372

AN AES/XPS STUDY OF THE CHEMISTRY OF PALLADIUM ...  

Science.gov (United States)

... AT THE INTERFACE, A THIN OXIDE LAYER IS OBSERVED ALONG WITH POSSIBLE PALLADIUM SILICIDES. PALLADIUM ...

1981-02-01

379
411

A STUDY TO DETERMINE THE DEFORMATION ...  

Science.gov (United States)

... crystals and polycrystals. Nevertheless, explosive forming, magnetic forming, etc., are all high-strain-rate processes that ...

1963-04-01

419

 

Medline Plus

... 2009) Arrhythmia Electrophysiological Study and Catheter Ablation with 3D Mapping (Mercy Hospital, Miami, FL, 11/15/2007) ...

420

Case studies and educational aids survey. A research report  

Energy Technology Data Exchange (ETDEWEB)

A survey was conducted to determine the sources of buildings energy conservation case studies and educational aids available in Canada. In total 785 consultants, educational institutions, building developers, manufacturers and government agencies were contacted. The results of this survey provide an indication of those agencies in Canada most actively involved with energy conservation in buildings, a listing of those agencies in Canada having case study information and/or educational aids materials available related to energy conservation in buildings, and a broad description of the subject area of the case studies and educational aids listed. The results of this study are intended to provide a source listing of energy conservation case studies and educational aids to the Buildings Energy Technology Transfer Program lead agencies and others conducting similar ...

1983-09-01

421

Brookhaven National Laboratory Coastal Meteorology Program, 1972-1983  

Energy Technology Data Exchange (ETDEWEB)

Research conducted at Brookhaven National Laboratory under the Coastal Meteorology and Diffusion Research Program from 1972 to 1983 is summarized by the following study areas: Diffusion Studies, Boundary Layer Studies, Coastal Meteorology Studies, Air-Sea Interaction Studies, Coastal Transport and Diffusion Climatology, Seabreeze Modeling and Instrument Development, all supported by the US Department of Energy. Studies supported by the Nuclear Regulatory Commission, the National Science Foundation and the American Petroleum Institute are also described. A summary of a Workshop on Coastal Atmospheric Transport Processes, an account of studies in progress, recommendations for future research and a description of facilities and instrumentation available are also included. A list of all publications and presentations prepared as part of the ...

1983-06-01

422

Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were proposed  

British Library Electronic Table of Contents (United Kingdom)

Objective: Results of reliability and agreement studies are intended to provide information about the amount of error inherent in any diagnosis, score, or measurement. The level of reliability and agreement among users of scales, instruments, or classifications is widely unknown. Therefore, there is a need for rigorously conducted interrater and intrarater reliability and agreement studies. Information about sample selection, study design, and statistical analysis is often incomplete. Because of inadequate reporting, interpretation and synthesis of study results are often difficult. Widely accepted criteria, standards, or guidelines for reporting reliability and agreement in the health care and medical field are lacking. The objective was to develop guidelines for reporting reliability and...

2011-01-01

423

Free radicals and their transformations in irradiated proteins  

International Nuclear Information System (INIS)

Experimental investigation data are systematized of free radical states and processes in irradiated proteins. The investigation is performed by the radiospectral methods. Results are discussed in detail of the study of free radicals electronic structure of amino acids, peptides and proteins formed by the action of ionizing radiation. The specificity is stressed of the study of monocrystalls of these compounds by the method of electronic paramagnetic resonance. The nature is also studied of primary centres formed under the effect of radiation on biologically important compounds and their subsequent reactions in solid and liquid solutions. Ion-radical states of different functional groups of the protein molecule are studied. Prospects of the study and the role of anion-radicals in biological processes are discusses.

424

Terror management among Taiwanese: Worldview defence or resigning to fate?  

British Library Electronic Table of Contents (United Kingdom)

Terror management theory (TMT) proposes that people who are reminded of their mortality should be motivated to defend their cultural worldview. Studies 1 and 2 examined whether the TMT worldview defence-buffering effect found in Western cultures could be generalized to Asians in Taiwan. No such effect was found in the present studies. This non-significant result was robust when either a stronger distraction task was used (study 1) or when a subliminal manipulation of mortality salience was utilized (study 2). A meta-analysis, including 24 TMT experiments in East Asia, was also conducted (study 3). The average effect size (d = 0.11, r = 0.055) of worldview defence among these experiments was not significantly different from zero. Study 4 found that mortality salience manipulation also did n...

2010-01-01

425

Technical design aspects of Feasibility Study-II  

Energy Technology Data Exchange (ETDEWEB)

Feasibility Study-II examined a high-performance Neutrino Factory providing 1 x 10{sup 20} neutrinos per year aimed at a long-baseline detector. The Study was sponsored jointly by BNL and the Neutrino Factory and Muon Collider Collaboration ration (MC) and is based on a 1 MW proton driver operating at 24 GeV, i.e., an upgraded version of the AGS accelerator. Compared with the earlier FNAL-sponsored study (Feasibility Study-I), there is a sixfold improvement in performance. Here we describe details of the implementation of Study-II concepts and discuss their efficacy. Alternative approaches that will be pursued in follow-on R and D activities are also described briefly.

2001-08-15

426

Scientific report 1997; Rapport scientifique 1997  

Energy Technology Data Exchange (ETDEWEB)

In this book are found technical and scientific papers on the main works of the Direction of the Fuel Cycle (DCC) in France. The study fields are: the up-side of the nuclear fuel cycle with theoretical studies (plasma simulation) and technological developments and instrumentation (lasers diodes, carbides plasma projection, carbon 13 enrichment); the down-side nuclear fuel cycle with theoretical studies (ion Eu{sup 3+} complexation simulation, decay simulation, uranium and plutonium diffusion study, electrolyser operating simulation), scenario studies ( recycling, wastes management), experimental studies; dismantling and cleaning (soils cleaning, surface-active agent for decontamination, fault tree analysis); analysis with expert systems and mass spectrometry. (A.L.B.)

1998-07-01

427

Industrial hazardous wastes in Finland - trends related to the waste prevention goal  

British Library Electronic Table of Contents (United Kingdom)

The objective of this study was to analyse one of the goals of the latest National Waste Plan of Finland: the relative reduction of hazardous waste (HW) generation by 15% over the period 1992 to 2005.Official statistics and a national database of the annual reports of HW generators were used as one basis for this study. A case study was focused on a selection of HW classes that were considered to be typical to the metal workshop industry. These HW classes were combined to form functional HW groups for the purpose of forming time series. Trends at the company level were studied by performing interviews and by studying the environmental permit documents of about 50 companies.The total amount of HW reported in Finland increased by 133% over the studied period. Meanwhile the GDP of Finland gre...

2008-01-01

428

Facial soft tissue response to anterior segmental osteotomies: A systematic review  

British Library Electronic Table of Contents (United Kingdom)

Bimaxillary protrusion is prevalent among Asians and anterior segmental osteotomies are commonly used for its surgical correction. The objective of this study was to evaluate the soft tissue changes resulting from anterior segmental osteotomies. The electronic databases PubMed, Scopus and ISI Web of knowledge were searched for potentially eligible studies using a set of predetermined keywords. Full texts meeting the inclusion criteria were retrieved and their references were manually searched for additional relevant articles. The study details and outcome data of these reports were extracted using spreadsheets for comparison. The methodological quality of each study was assessed. Eleven studies met the inclusion criteria. Lateral cephalometry was used in all studies. A reduction of the lab...

2010-01-01

429

Economic study of a rural underground transmission system: A site-specific case study: Final report  

Energy Technology Data Exchange (ETDEWEB)

This report presents the data and results of a site specific case study comparing costs of an overhead line with an underground circuit traversing the same route. The costs used for the overhead line are actual numbers for a line scheduled to be built by a utility. The underground circuit costs were developed using the same criteria of line rating, contingencies, and location. Often cost comparisons between overhead and underground lines are made using figures taken from studies with widely varying assumptions. This project attempts to provide a comparison by studying the costs of overhead and underground lines following the same route and using the same design assumptions. Caution must be used, however, in extending the results of this study beyond its original intent. It is site-specific and may be representative of only one area of the country. 9 refs., 23 figs., 18 tabs.

1987-10-01

430

Association and expression study of synapsin III and schizophrenia  

British Library Electronic Table of Contents (United Kingdom)

The synapsin III gene, SYN3, which belongs to the family of synaptic vesicle-associated proteins, has been implicated in the modulation of neurotransmitter release and in synaptogenesis, suggesting a potential role in several neuropsychiatric diseases. The human SYN3 gene is located on chromosome 22q12-13, a candidate region implicated in previous linkage studies of schizophrenia. However, association studies of SYN3 and schizophrenia have produced inconsistent results. In this study, four SYN3 SNPs (rs133945 (-631 C>G), rs133946 (-196 G>A), rs9862 and rs1056484) were tested in three sets of totally 3759 samples that comprise 655 affected subjects and 626 controls in the Irish Case-Control Study of Schizophrenia (ICCSS), 1350 samples incorporating 273 pedigrees in the Irish Study of High D...

2009-01-01

431

Utilization of Carbon Monoxide (CO) Of the Flue Gas of a Hot Air Cupola Furnace Used for Melting.  

Science.gov (United States)

In this study the technical and economical possibilities of burning carbon monoxide (CO) of the flue gas and utilizing of the released heat in hot air cupola furnace used for melting have been studied. As basis for examining was burning of cleaned furnace...

1986-01-01

432

Twenty Years of Public Health Research: Inclusion of Lesbian, Gay, Bisexual, and Transgender Populations  

UK PubMed Central (United Kingdom)

Objectives. This study determined to what extent lesbian, gay, bisexual, and transgender (LGBT) populations have been studied over the past 20 years of public health research.Methods....Full Text Available

2002-07-01

433

Trial of early nifedipine in acute myocardial infarction: the Trent study.  

UK PubMed Central (United Kingdom)

Over 30 months 9292 consecutive patients admitted to nine coronary care units with suspected myocardial infarction were considered for admission to a randomised double blind study comparing the effect...Full Text Available

1986-11-08

434

Transcriptional profile of isoproterenol-induced cardiomyopathy and comparison to exercise-induced cardiac hypertrophy and human cardiac failure  

UK PubMed Central (United Kingdom)

BackgroundIsoproterenol-induced cardiac hypertrophy in mice has been used in a number of studies to model human cardiac disease. In this study, we compared the transcriptional response...Full Text Available

435

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

UK PubMed Central (United Kingdom)

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

2006-01-01

436

The impact of water intake on energy intake and weight status: a systematic review  

UK PubMed Central (United Kingdom)

The effects of consuming water with meals rather than drinking no beverage or various other beverages remains under-studied. This systematic review of English language studies compared the effects...Full Text Available

2010-09-01

437

The Relationship between Intimate Partner Violence, Rape and HIV amongst South African Men: A Cross-Sectional Study  

UK PubMed Central (United Kingdom)

ObjectiveTo investigate the associations between intimate partner violence, rape and HIV among South African men.DesignCross-sectional study involving...Full Text Available

438

The Non-linear Relationship between Gait Speed and Falls: The MOBILIZE Boston Study  

UK PubMed Central (United Kingdom)

OBJECTIVESAlthough several studies suggest that slow gait speed is a predictor of falls, it may also be a protective mechanism to prevent falls. Further, fast walking...Full Text Available

2011-06-01

439

Taking social relationships seriously: Lessons learned from the informed consent practices of a vaccine trial on the Kenyan Coast  

UK PubMed Central (United Kingdom)

AbstractIndividual informed consent is a key ethical obligation for clinical studies, but empirical studies show that key requirements are often not met. Common recommendations to strengthen...Full Text Available

2008-09-01

440

Study of particles trapped by a magnetic field  

Science.gov (United States)

A new type of radiation which occurs when particles are accelerated in the field of a longitudinal wave and in a transverse magnetic field is studied. The characteristics of such spontaneous radiation are obtained, and the influence of collective effects on the radiation is analyzed. The application of the findings to the theory of free electron lasers is discussed. 8 references.

1986-01-01

441

Studies on micellar fatty acid uptake by rat intestine in vitro with reference to the role of bile  

UK PubMed Central (United Kingdom)

1. The uptake and esterification to trigylceride of oleic acid in micellar form was studied in rat intestine in vitro. Sacs of the upper half of the everted intestine taken from bile...Full Text Available

1973-03-01

442

Solid state and materials research: metal-semiconductor interactions  

International Nuclear Information System (INIS)

This section of the report is concerned with the study of the metallisation, oxidation and doping of materials which are of importance to the micro-electronics industry. The Van de Graaff accelerator and radioactive tracers are used for studying surface and sub-surface behaviour of these materials.

443

Risks of consumption of contaminated seafood: the Quincy Bay case study.  

UK PubMed Central (United Kingdom)

A recent EPA-sponsored study of sediment and seafood contamination in Quincy Bay revealed elevated levels of several complex organic pollutants frequently of concern in human health assessments. A seafood...Full Text Available

1991-01-01

444

Risk of hematological malignancies associated with magnetic fields exposure from power lines: a case-control study in two municipalities of northern Italy  

UK PubMed Central (United Kingdom)

BackgroundSome epidemiologic studies have suggested an association between electromagnetic field exposure induced by high voltage power lines and childhood leukemia, but null results...Full Text Available

445

Risk management in design engineering bids  

Energy Technology Data Exchange (ETDEWEB)

Accurate engineering cost estimates are critical in developing bids for new work, and for effective resource allocation and project control. This study reports on design estimating methods found in the literature, and on the results of two empirical studies of how estimating techniques are used in professional practice and their accuracy. The study found great reliance on a classic {open_quotes}activity analysis{close_quotes} approach to estimating design resources, and significant hazards in commonly used parametric techniques. The study found that project managers expect their estimates to be accurate (with 80% confidence interval) of between -10% to +25%. The study also found that actual bids between engineering firms had a much greater range (-40% to +45%) than can be explained by accuracy. Perhaps most importantly the study found that none of the sampled ...

1995-06-01

446

Reverse Engineering of Gene Regulatory Networks: A Comparative Study  

UK PubMed Central (United Kingdom)

Reverse engineering of gene regulatory networks has been an intensively studied topic in bioinformatics since it constitutes an intermediate step from explorative to causative gene expression...Full Text Available

2009-01-01

447

Retrospective identification and characterization of mild cognitive impairment from a prospective population cohort  

UK PubMed Central (United Kingdom)

ObjectivesMild Cognitive Impairment (MCI) case-finding criteria have low specificity in general population studies. The present study retrospectively identifies cases...Full Text Available

2010-08-01

448

Radiographic monitoring of incidental abdominal aortic aneurysms: a retrospective population-based cohort study  

UK PubMed Central (United Kingdom)

BackgroundAn abdominal aortic aneurysm (AAA) that is identified when the abdomen is imaged for some other reason is known as an incidental AAA. No population-based studies have...Full Text Available

449

Psychopathological features of irritable bowel syndrome patients with and without functional dyspepsia: a cross sectional study  

UK PubMed Central (United Kingdom)

BackgroundIrritable bowel syndrome (IBS) and functional dyspepsia (FD) show considerable overlap and are both associated with psychiatric comorbidity. The present study aimed to...Full Text Available

450

Properties of cellulose solutions in methylmorpholine N-oxide containing montmorillonite nanoparticles and of composite films thereof  

British Library Electronic Table of Contents (United Kingdom)

Rheological properties of moderately concentrated solutions of cellulose in methylmorpholine N-oxide-dimethylformamide mixtures containing hydrophilic montmorillonite nanoparticles were studied. Film composite materials were prepared, and their physicomechanical properties and structural organization were studied.

2011-01-01

451

Pregnant women's working conditions and their changes during pregnancy: a national study in France.  

UK PubMed Central (United Kingdom)

In a study of 2387 employed women who had worked for more than three months of their pregnancy the data were extracted from a survey carried out on a national sample of births in France in 1981. Manual,...Full Text Available

1987-04-01

452

Post traumatic stress symptoms and heart rate variability in Bihar flood survivors following yoga: a randomized controlled study  

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

453

Plasminogen-125I responses in dogs to a single injection of urokinase and typhoid vaccine and to vascular injury  

UK PubMed Central (United Kingdom)

In vivo plasminogen responses to various stimuli were studied. Plasminogen-125I was prepared and used first for metabolic studies of plasminogen in control dogs. The average results were:...Full Text Available

1972-06-01

454

Photochemical injury to the foveomacula of the monkey eye following argon blue-green panretinal photocoagulation.  

UK PubMed Central (United Kingdom)

PURPOSE: Visual loss following panretinal photocoagulation was found in the Diabetic Retinopathy and the Early Treatment Diabetic Retinopathy Studies. This study was designed to test the hypothesis...Full Text Available

2000-01-01

455

Pain and pain-related interference in adults with lower-limb amputation: Comparison of knee-disarticulation, transtibial, and transfemoral surgical sites  

UK PubMed Central (United Kingdom)

Pain and pain-related interference with physical function have not been thoroughly studied in individuals who have undergone knee-disarticulation amputations. The principal aim of this study...Full Text Available

2009-01-01

456

Ocular motility in alternating squints: an electro-oculographic study.  

UK PubMed Central (United Kingdom)

Ocular movements were studied electro-oculographically in 10 normal subjects and 10 patients with alternating strabismus. Fixation and pursuit movements and to a less extent the saccadic movements were...Full Text Available

1982-04-01

457

Myofibrillogenesis in the developing zebrafish heart: A functional study of tnnt2  

UK PubMed Central (United Kingdom)

Various hypotheses have been proposed to explain the molecule processes of sarcomere assembly, partially due to the lack of systematic genetic studies of sarcomeric genes in an in vivo...Full Text Available

2009-07-15

458

Modulation of leg muscle function in response to altered demand for body support and forward propulsion during walking  

UK PubMed Central (United Kingdom)

A number of studies have examined the functional roles of individual muscles during normal walking, but few studies have examined which are the primary muscles that respond to changes in external...Full Text Available

2009-05-11

459

Model Study of Instant Vehicular Camouflage.  

Science.gov (United States)

A feasibility study to determine what materials and geometric systems would be required for fabrication of a camouflage system that would instantaneously cover a military vehicle in order to disrupt its characteristic shape or outline. The program involve...

1973-01-01

460

Lin28a transgenic mice manifest size and puberty phenotypes identified in human genetic association studies  

UK PubMed Central (United Kingdom)

Recently, genome-wide association studies (GWAS) have linked the human LIN28B locus to height and timing of menarche [1-Full Text Available

2010-07-01

461

Innovation and survival: a case study in planning medical library services.  

UK PubMed Central (United Kingdom)

In the information age, information utilities like libraries are as sensitive to the stresses of change as any other organization. This article is a case study of a small, specialized medical library...Full Text Available

1998-10-01

462

In vivo study of chloroplast volume regulation.  

UK PubMed Central (United Kingdom)

This paper describes a new technique that can be used to study chloroplast volume regulation in vivo. Nuclear magnetic resonance spectroscopy was used to measure relative amounts of chloroplast water...Full Text Available

1992-05-01

463

Identifying barriers to Papanicolaou smear screening in Korean women: Korean National Health and Nutrition Examination Survey 2005  

UK PubMed Central (United Kingdom)

ObjectiveThis study was conducted to provide a nationwide analysis on barriers to cervical cancer screening in Korea.MethodsData used for this study...Full Text Available

2010-06-01

464

How Missing Information in Diagnosis Can Lead to Disparities in the Clinical Encounter  

UK PubMed Central (United Kingdom)

Previous studies have documented diagnostic bias and noted that its reduction could eliminate misdiagnosis and improve mental health service delivery. Few studies have investigated clinicians'...Full Text Available

2008-11-01

465

Health and function of participants in the Long Life Family Study: A comparison with other cohorts  

UK PubMed Central (United Kingdom)

Individuals from families recruited for the Long Life Family Study (LLFS) (n= 4559) were examined and compared to individuals from other cohorts to determine whether the recruitment targeting longevity...Full Text Available

466

Genetic association between the COMT genotype and urinary levels of tea polyphenols and their metabolites among daily green tea drinkers  

UK PubMed Central (United Kingdom)

Available in vitro and animal studies have shown cancer protective effects of tea polyphenols. Recent study suggests a greater protective effect of green tea intake on breast cancer...Full Text Available

467

Five year prospective study of plasma renin activity and blood pressure in patients with longstanding reflux nephropathy.  

UK PubMed Central (United Kingdom)

Eight of 100 normotensive children who had pyelonephritic scarring secondary to urinary infection and vesicoureteric reflux were found in an earlier study to have increased plasma renin activity (PRA)....Full Text Available

1987-07-01

468

Estimating Missing Heritability for Disease from Genome-wide Association Studies  

UK PubMed Central (United Kingdom)

Genome-wide association studies are designed to discover SNPs that are associated with a complex trait. Employing strict significance thresholds when testing individual SNPs avoids false positives at...Full Text Available

2011-03-11

469

Epidermal keratinocytes do not activate peripheral T-cells: interleukin-10 as a possible regulator  

UK PubMed Central (United Kingdom)

The immunogenicity of allogeneic cultured human epidermal keratinocytes (cHEKs) has been studied in several models with contradictory results. We studied human T-cell activation in an in vitro...Full Text Available

2008-11-01

470

Electron Spin Resonance Studies of Ionic Permeability Properties of Thylakoid Membranes of Beta vulgaris and Avicennia germinans1  

UK PubMed Central (United Kingdom)

Measurement of intrathylakoid aqueous volumes by electron spin resonance spectroscopy was used to study ionic permeability properties of thylakoid membranes isolated from Beta vulgaris...Full Text Available

1985-05-01

471

ESR studies of spin-labeled membranes aligned by isopotential spin-dry ultracentrifugation: lipid-protein interactions.  

UK PubMed Central (United Kingdom)

Electron spin resonance (ESR) studies have been performed on spin-labeled model membranes aligned using the isopotential spin-dry ultracentrifugation (ISDU) method of Clark and Rothschild. This method...Full Text Available

1994-12-01

472

Dual Beneficial Effects of (-)-Epigallocatechin-3-Gallate on Levodopa Methylation and Hippocampal Neurodegeneration: In Vitro and In Vivo Studies  

UK PubMed Central (United Kingdom)

BackgroundA combination of levodopa (L-DOPA) and carbidopa is the most commonly-used treatment for symptom management in Parkinson's disease. Studies have shown that concomitant...Full Text Available

473

Divorce, divorce rates, and professional care seeking for mental health problems in Europe: a cross-sectional population-based study  

UK PubMed Central (United Kingdom)

BackgroundLittle is known about differences in professional care seeking based on marital status. The few existing studies show more professional care seeking among the divorced...Full Text Available

474

Developing IT Infrastructure for Rural Hospitals: A Case Study of Benefits and Challenges of Hospital-to-Hospital Partnerships  

UK PubMed Central (United Kingdom)

This article presents a study identifying benefits and challenges of a novel hospital-to-hospital information technology (IT) outsourcing partnership (HHP). The partnership is an innovative response...Full Text Available

2008-07-01

475

Critical review of studies on atmospheric dispersion in coastal regions  

Energy Technology Data Exchange (ETDEWEB)

This study effort was required as a preliminary step prior to initiation of field measurements of atmospheric dispersion in coastal regions. The Nuclear Regulatory Commission (NRC) is in the process of planning an extensive field measurement program to generate data which will serve as improved data bases for licensing decisions, confirmation of regulations, standards, and guides, and for site characterizations. The study being reported here is an effort directed to obtaining as much information as is possible from existing studies that is relevant toward NRC's objectives. For this study, reports covering research and meteorological measurements conducted for industrial purposes, utility needs, military objectives, and academic studies were obtained and critically reviewed in light of NRC's current data needs. This report provides an interpretation of the extent of ...

1982-09-01

476

Common genetic variation and susceptibility to partial epilepsies: a genome-wide association study  

UK PubMed Central (United Kingdom)

Partial epilepsies have a substantial heritability. However, the actual genetic causes are largely unknown. In contrast to many other common diseases for which genetic association-studies have successfully...Full Text Available

2010-07-01

477

Cobalt-57-bleomycin scanning of hila and mediastinum in patients with bronchial carcinoma: a prospective study.  

UK PubMed Central (United Kingdom)

Because the results with cobalt-57-bleomycin (57Co-bleo) as a tumour-seeking agent in patients with pulmonary tumours were promising, a prospective study was carried out to test the sensitivity and...Full Text Available

1976-12-01

478

Clinical and laboratory studies in patients with leprosy and enthesitis.  

UK PubMed Central (United Kingdom)

In a combined clinical, radiological, and laboratory study of 77 patients throughout the leprosy spectrum, 10 patients had an enthesitis which has not been described previously as far as is known and...Full Text Available

1990-09-01

479

Chronic lymphatic leukaemia and engine exhausts, fresh wood, and DDT: a case-referent study.  

UK PubMed Central (United Kingdom)

The effect of potential risk factors for chronic lymphatic leukaemia was evaluated in a case-referent study encompassing 111 cases and 431 randomised referents, all alive. Information on exposure was...Full Text Available

1988-01-01

480

Childhood cancer and overhead powerlines: a case-control study.  

UK PubMed Central (United Kingdom)

A case-control study has been carried out to examine the occurrence of childhood cancer in relation to the proximity of overhead power lines to a child's home address at birth and to the calculated...Full Text Available

1990-12-01

481

Carboxymethylation of peat in 2-propanol  

British Library Electronic Table of Contents (United Kingdom)

The effects of the time and temperature of alkaline pretreatment and the time and temperature of the carboxymethylation of peat in 2-propanol on the concentration of carboxymethyl groups and the solubility of the resulting products in water and an aqueous alkali solution were studied. The viscosity characteristics of the aqueous and aqueous alkaline solutions of peat carboxymethylation products were studied.

2011-01-01

482

Candidate salivary biomarkers associated with alveolar bone loss: cross-sectional and in vitro studies  

UK PubMed Central (United Kingdom)

This cross-sectional study evaluated the association between radiographic evidence of alveolar bone loss and the concentration of host-derived bone resorptive factors (interleukin-1 beta, tumor...Full Text Available

2007-03-01

483

Association between skin diseases and severe bacterial infections in children: case-control study  

UK PubMed Central (United Kingdom)

BackgroundSepsis or bacteraemia, however rare, is a significant cause of high mortality and serious complications in children. In previous studies skin disease or skin infections...Full Text Available

484

Association between length of storage of red blood cell units and outcome of critically ill children: a prospective observational study  

UK PubMed Central (United Kingdom)

IntroductionTransfusion is a common treatment in pediatric intensive care units (PICUs). Studies in adults suggest that prolonged storage of red blood cell units is associated with...Full Text Available

2010-01-01

485

Association Study of Serine Racemase Gene with Methamphetamine Psychosis  

UK PubMed Central (United Kingdom)

Experimental studies have demonstrated that not only dopaminergic signaling but also glutamatergic/NMDA receptor signaling play indispensable roles in the development of methamphetamine psychosis. Our...Full Text Available

2011-03-01

486

Assessment of a bone biopsy technique for measuring tiludronate in horses: A preliminary study  

UK PubMed Central (United Kingdom)

This study assessed the feasibility of measuring tiludronate in horses using a minimally invasive bone biopsy technique. Eight horses were treated with intravenous (IV) tiludronate [1 mg/kg bodyweight...Full Text Available

2011-04-01

487

Army Corps as a Joint Task Force Headquarters.  

Science.gov (United States)

This study investigates the doctrinal guidance available to a corps headquarters if required to serve as ajoint task force headquarters and simultaneously be required to warfight the corps. The study contends that a corps being required to simultaneously ...

1997-01-01

488

Application of tumor, bacterial and parasite susceptibility assays to study immune alterations induced by environmental chemicals  

UK PubMed Central (United Kingdom)

Model systems to study the effects of chemicals of environmental concern on bacterial and parasitic diseases as well as the immunosurveillance and destruction of transplantable tumor cells were described...Full Text Available

1982-02-01

489

Antibody protects against lethal infection with the neurally spreading reovirus type 3 (Dearing).  

UK PubMed Central (United Kingdom)

The mammalian reoviruses have provided a valuable model for studying the pathogenesis of viral infections of the central nervous system (CNS). We have used this model to study the effect of antibody...Full Text Available

1988-12-01

490

An Evaluation of the Value of Choice with Preschool Children  

UK PubMed Central (United Kingdom)

The current study examined the reinforcing effects of choosing among alternatives in a four-part evaluation. In the first study, initial-link responses in a concurrent-chains arrangement resulted in...Full Text Available

2006-01-01

491

Amorphous to crystalline phase transformation in Metglas reg-sign studied by Moessbauer spectroscopy  

International Nuclear Information System (INIS)

The authors present differential scanning calorimetry (DSC) and in situ Moessbauer spectroscopy results for Metglas ribbons, to which different heat treatments were made. The Curie temperature of the amorphous phase is determined and the evolution of the magnetic field of this phase is studied as a function of temperature

1997-12-01

492

Ak-Chin Indian Community Biomass Feasiiblity Study  

Energy Technology Data Exchange (ETDEWEB)

Study of the conversion of chicken litter to biogas for the production of energy. There was an additional requirement that after extracting the energy from the chicken litter the nutrient value of the raw chicken litter had to be returned to the Ak-Chin Farms for use as fertilizer in a form and delivery method acceptable to the Farm.

2005-12-31

493

Addressing the Question of the Effect of RBC Storage on Clinical Outcomes: The Red Cell Storage Duration Study (RECESS) (Section 7)  

UK PubMed Central (United Kingdom)

The question of whether storage of red blood cells (RBCs) alters their capacity to deliver oxygen and affects patient outcomes remains in a state of clinical equipoise. Studies of the changes...Full Text Available

2010-08-01

494

A prospective randomised study on the long-term effect of lumbar fusion on adjacent disc degeneration  

UK PubMed Central (United Kingdom)

The existence and importance of an accelerated adjacent segment disc degeneration (ASD) after lumbar fusion have previously not been demonstrated by RCTs. The objectives of this study were, to determine...Full Text Available

2009-08-01

495

A nested case-control study of maternal-neonatal transmission of hepatitis B virus in a Chinese population  

UK PubMed Central (United Kingdom)

AIM: To examine the determinants of maternal-neonatal transmission of hepatitis B virus (HBV).METHODS: A nested case-control study was conducted in Changsha, Hunan, People’s Republic...Full Text Available

2011-08-21

496

A case cohort study of suicide in relation to exposure to electric and magnetic fields among electrical utility workers.  

UK PubMed Central (United Kingdom)

OBJECTIVES--This case cohort study examines whether there is an association between exposure to electric and magnetic fields and suicide in a population of 21,744 male electrical utility workers from...Full Text Available

1996-01-01

497

A Longitudinal Study of Incarceration and HIV Risk Among Methadone Maintained Men and Their Primary Female Partners  

UK PubMed Central (United Kingdom)

This study examines the longitudinal relationship between personal and sexual partner incarceration and subsequent HIV risk behaviors among drug-involved men and their primary female sexual...Full Text Available

2011-02-01

498

A Controlled Challenge Study on Di(2-ethylhexyl) Phthalate (DEHP) in House Dust and the Immune Response in Human Nasal Mucosa of Allergic Subjects  

UK PubMed Central (United Kingdom)

BackgroundFew studies have yet addressed the effects of di(2-ethylhexyl) phthalate (DEHP) in house dust on human nasal mucosa.ObjectivesWe investigated...Full Text Available

2008-11-01

499

A Comparative Study of 25 (OH) Vitamin D Serum Levels in Patients with Multiple Sclerosis and Control Group in Isfahan, Iran  

UK PubMed Central (United Kingdom)

Objectives:There is no study about correlation between vitamin D serum level and multiple sclerosis (MS) in Iran. So in this survey, we investigated the serum level of 25-hydroxy...Full Text Available

2010-01-01