A new industrial process allowing to reach very high cooling rates in the cooling section after soaking of a continuous annealing line for steel sheets is presented. This process constitutes the successful conclusion of a long term research programme, jointly carried out at CRM and Arcelor Cockerill-Sambre for three years, including laboratory experiments, pilot scale trials and several industrial campaigns. It is running on from developments performed in the framework of the HOWAQ (Hot Water Quench) process. The process successively combines a moderate cooling step (600 deg C/s for 0.8 mm thick strips), in boiling water, and a faster cooling step (above 700 deg C/s), by impinging turbulent cold water in a box. Its main features are simplicity, resulting from advanced developments, soundness, flexibility and cooling homogeneity. As treated steel products are characterized by improved mechanical properties, outstanding surface quality (corrosion resistance) and exceptional flatness. The ...
We present and characterize a very efficient optical device that employs the plasma mirror technique to increase the contrast of high-power laser systems. Contrast improvements higher than 104 with 50% transmission are shown to be routinely achieved on a typical 10 TW laser system when the pulse is reflected on two consecutive plasma mirrors. Used at the end of the laser system, this double plasma mirror preserves the spatial profile of the initial beam, is unaffected by shot-to-shot fluctuations, and is suitable for most high peak power laser systems. We use the generation of high-order harmonics as an effective test for the contrast improvement produced by the double plasma mirrors. (authors)
T_2 weighted ultra-short turbo spin echo sequences were used in five individuals with variations in echo times, delayed triggering and echo intervals. To reduce movement artifacts all examinations were carried out with ECG and respiratory triggering. The sequences giving optimal image quality were then employed in 19 patients having various pulmonary abnormalities. Image resolutions, artifacts, image contrasts and diagnostic value were then judged by two observers and compared with CT. In the first study, a diastole-triggered UTSE sequence with the shortest echo proved optimal (T_E=90 ms, T_R=2-4 s, echo=9 ms, turbo factor=19). In the patient series studied, MRT was inferior to CT with regard to resolution and number of artifacts, but better in respect of contrast and diagnostic value. Using UTSE of the lung, MRT can produce images of good quality. Compared with CT, contrast is better with MRT, offering ...
Ultra-high resolution radiographs can be obtained using synchrotron X-rays. A collaboration team consisting of K-JIST, POSTECH and YUMC has recently commissioned a new beamline (5C1) at Pohang Light Source (PLS) in Korea for medical applications using phase contrast radiology. Relatively simple image acquisition systems were set up on 5C1 beamline, and imaging studies were performed for resolution test patterns, mammographic phantom, and animals. Resolution test patterns and mammographic phantom images showed much better image resolution and quality with the 5C1 imaging system than the mammography system. Both fish and mouse images with 5C1 imaging system also showed much better image resolution with great details of organs and anatomy compared to those obtained with a conventional mammography system. A simple and inexpensive ultra-high resolution imaging system on 5C1 beamline was successfully implemented. The authors were ...
French English ... Orig. Title Imagerie IRM des lesions focales hepatiques avec les antennes de surface en reseau phase (phased array): apnee ou imagerie haute resolution?.
T{sub 2} weighted ultra-short turbo spin echo sequences were used in five individuals with variations in echo times, delayed triggering and echo intervals. To reduce movement artifacts all examinations were carried out with ECG and respiratory triggering. The sequences giving optimal image quality were then employed in 19 patients having various pulmonary abnormalities. Image resolutions, artifacts, image contrasts and diagnostic value were then judged by two observers and compared with CT. In the first study, a diastole-triggered UTSE sequence with the shortest echo proved optimal (T{sub E}=90 ms, T{sub R}=2-4 s, echo=9 ms, turbo factor=19). In the patient series studied, MRT was inferior to CT with regard to resolution and number of artifacts, but better in respect of contrast and diagnostic value. Using UTSE of the lung, MRT can produce images of good quality. Compared with CT, contrast is better ...
This short paper (abstract) describes the characteristics and performances of prototypes of ultra-thin lithium micro-batteries (thickness < 0.2 mm) which can be incorporated into microelectronic circuits. (J.S.)
Detecting a camouflaged target in a visually noisy background depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels can act as a masking source by compromising or reducing the observer's ability to resolve differences in the visual scene. Previous research has examined this concept by investigating laser flash effects on: acuity (size discrimination); tracking (motion discrimination); visual sensitivity (color); and contrast sensitivity functions (luminance contrast). In all cases, flashes from continuous-wave (CW) sources have proven more effective visually than pulsed (Q-switched) sources, when compared on peak-energy criteria (i.e., MPE), even though Q-switched lasers induce damage at lower energy doses. Additionally, the inherent safety of ultra-short laser pulses has been questioned. Past animal research has shown ...
Ultra-shallow junction formation in deep submicron Si devices is limited by anomalous diffusion of the dopant, which is related to the release of interstitials from defect clusters formed during the implantation of energetic ions or the subsequent annealing. The work described in this dissertation is concerned with the effects of low energy B ion implantation, especially damage formation, clustering and its annealing. After a review of the stopping and ranges of energetic ions in Si, the formation of implant damage, in particular of point defects, their migration, agglomeration and annihilation, including the involvement of dopant ions, is considered. A description of the Salford ultra low energy implanter is given and the main analysis technique, medium ion energy scattering (MEIS) reviewed. Additional analytical techniques used, such as secondary ion mass spectrometry (SIMS), 4-point probe and cross section transmission microscopy (XTEM) as ...
Ultra-low pure Pt-based electrodes (0.04-0.12 mg_P_t/cm"2) were prepared by dual ion-beam assisted deposition (dual IBAD) method on the surface of a non-catalyzed gas diffusion layer (GDL) substrate. Film thicknesses ranged between 250 and 750 A, these are compared with a control, a conventional Pt/C (1.0 mg_P_t_(_M_E_A_)/cm"2, E-TEK). The IBAD electrode constituted a significantly different morphology, where low density Pt deposits (largely amorphous) were formed with varying depths of penetration into the gas diffusion layer, exhibiting a gradual change towards increasing crystalline character (from 250 to 750 A). Mass specific power density of 0.297 g_P_t/kW is reported with 250 A IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V. This is contrasted with the commercial MEA with a loading of 1 mg_P_t_(_M_E_A_)/cm"2 where mass specific power density obtained was 1.18 g_P_t/kW (at 0.65 V), a value typical of ...
Ultra low loading noble metal (0.04-0.12 mg_P_t/cm"2) based electrodes were obtained by direct metallization of non-catalyzed gas diffusion layers via dual ion beam assisted deposition (IBAD) method. Fuel cell performance results reported earlier indicate significant improvements in terms of mass specific power density of 0.297 g_P_t/kW with 250 A thick IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V in contrast to the state of the art power density of 1.18 g_P_t/kW using 1 mg_P_t_(_M_E_A_)/cm"2 at 0.65 V. In this article we report the peroxide radical initiated attack of the membrane electrode assembly utilizing IBAD electrodes in comparison to commercially available E-TEK (now BASF Fuel Cell GmbH) electrodes and find the pathway of membrane degradation as well. A novel segmented fuel cell is used for this purpose to relate membrane degradation to peroxide generation at the electrode/electrolyte interface ...
CIGRE has set up a new working group - Insulated High Voltage Cables - under the auspices of Study Group 21. The working group will examine the various techniques used for the installation of HV and EHV cables and the design parameters to be applied. Twelve installation techniques are known, but only three of these ar used at present. Following an international study carried out by the working group, a clear picture of the state of the art in 1998 has emerged. It has also been possible to identify future trends in the design of buried circuits. (authors)
This document presents the activity of KiloFarad International (KFI), a trade association for the promotion of the interests of the international ultra-capacitor industry through education and representation. KFI provides a forum for the ultra-capacitor industry to work on non-competitive activities (standards, working groups, test procedures etc..). The rest of the document presents some informations about ultra-capacitors technology and some advanced applications in the automotive and telecommunication industries. (J.S.)
Three HQE (High Quality of the Environment) realizations are presented to illustrate the environmental quality in the architecture, and to see how the natural gas answers the demands of the HQE. (A.L.B.)
In the framework of the feasibility study of radioactive waste disposal in deep geologic formations, a clay formation (named 'argilite de l'Est') has been selected in the Meuse-Haute Marne region (France) for the construction of an underground laboratory. The percolation of alkaline solutions through the argilite has been studied using column experiments with short residence times (30 min). These experiments simulate the leaching of a cement which could be used in the building materials of the laboratory. The alkaline solutions used are mono-cationic solutions of calcium, sodium and strontium. The behaviour of calcium is differentiated from the other cations. For all alkaline solutions (NaOH, Ca(OH){sub 2} or Sr(OH){sub 2}) chemical reactions consuming both hydroxide ions and their associated cations have been evidenced. These reactions are heterogenous reactions of surface adsorption by site ionization. The calcium has a different ...
This report presents the main conclusions of 15 years of researches managed by the CEA. This report is the preliminary version of the 2005 final report. It presents the main conclusions of the actions on the axis 1 and 3 of the law of the 30 December 1991. The synthesis report on the axis 1 concerns results obtained on the long lived radionuclides separation and transmutation in high level and long lived radioactive wastes. the synthesis report on the axis 3 presents results obtained by the processes of conditioning and of ground and underground long term storage. (A.L.B.)
Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.
The Segmented Rail Phased Induction Motor (SERAPHIM) is a compact, pulsed linear induction motor (LIM) offering a unique capability for very high speed train propulsion. It uses technology developed for the Sandia coilgun, an electromagnetic launcher designed to accelerate projectiles to several kilometers per second. Both aluminum cylinders and plates were accelerated to a kilometer per second (Mach 3) by passing through a sequence of coils which were energized at the appropriate time. Although this technology was developed for ultra-high velocity, it can be readily adapted to train propulsion for which, at sea level, the power required to overcome air resistance limits the operational speed to a more modest 300 mph. Here, the geometry is reversed. The coils are on the vehicle and the ``projectiles`` are fixed along the roadbed. SERAPHIM operates not by embedding flux in a conductor, but by excluding it. In this propulsion scheme, pairs of closely spaced coils on ...
A historical review on insulated cables for power transmission, is presented, beginning with impregnated paper insulation, oil filled cables and natural rubber cables. High density and chemically reticulated polyethylene were then used for high voltage and very high voltage cables; the advantages of polyethylene compared to impregnated paper cables are discussed, which led to research programs at EDF on various themes concerning the optimization of polyethylene cables: dielectric properties and reliability, thermomechanical behaviour, thermal ageing of materials, testing methods (acceptance dielectric test and long duration temperature test); utilization of low- and high-density and chemically reticulated polyethylene for 225 kV cables is discussed
The aim of the safety calculation is to quantify through numerical modelling the radiological impact (molar flow, human dose) of a potential repository for radioactive waste on the Meuse/Haute Marne site at Bure. A selection process is underway for safety scenarios and their phenomenological and numerical conceptual models upstream from the safety calculation. This involves defining and quantifying the geometric and dimensional representations of the repository for each scenario plus the physical, mathematical and numerical models that reflect its behaviour and the uncertainties associated with all the parameters required to quantify the impact. A summary will be given of these various aspects. The numerical simulations are then performed on the Alliances platform which integrates the various computer codes required for the physical representation of the system. (authors)
As a consequence of the close integration of cattle into the food chain of humans, forensically relevant cases involving cattle (Bos taurus) DNA analysis are common. However, scientific publications reporting the information content of the commonly used bovine short tandem repeat (STR) loci remains scarce. Population studies were performed for 16 polymorphic STR loci (BM1818, BM1824, BM2113, CSRM60, CSSM66, ETH3, ETH10, ETH225, HAUT27, ILSTS006, INRA023, SPS115, TGLA53, TGLA122, TGLA126, and TGLA227) including 4,162 randomly selected cattle representing 20 distinct breeds. The power of parental exclusion, expected and observed heterozygosity, probability of identity, and non-amplifying (?null?) allele frequencies were calculated. Major differences existed in the information content between...
The law of the 30 December 1991 on the high activity long lived radioactive wastes reached the end. This synthesis final document presents the scientific and technological results, obtained still the end of 2005, on the separation and the transmutation of long lived radionuclides of high activity long lived radioactive wastes. It is organized in five chapters: a presentation of the context and the historical aspects, the researches, the objectives and the strategy of the axis 1, the researches results on the advanced separation, the researches results on the transmutation, the scenario of separation-transmutation and their environmental, technical and economical impacts. (A.L.B.)
The electrochemical performances of orthorhombic LiMnO{sub 2} compounds are analyzed in order to find a structural and/or morphological origin to the differences of electrochemical behaviours observed in compounds with different size of crystallites and different amounts of lattice defects. Energy capacity performances of 200 Ah/kg are reached for materials with crystallites of about 10{sup 7} Angstrom{sup 3} and with about 7% of defects, while energy capacities of only 80 Ah/kg are obtained for materials with ten times bigger crystallites. (J.S.) 3 refs.
The aim of this work is the study of the heat transfer and of thermal behaviour of the HF (high frequency) components (in fact capacitors) of the ITER-proto-2005-FCI antenna. Preliminary results carried out with the Castem software show that it is possible to cool the hottest part of the antenna efficiently. A water flow (1 bar, 25 Celsius degrees) or an helium flow (10 bars, 50 Celsius degrees) permit to limit the maximal value of the temperature to 270 Celsius degrees. A second software Ansys has allowed the author to simulate capacitors with more complicated shapes. (A.C.)
The NREL Sensitized Solar Cell (SSC) Core Program supports the Solar America Initiative by: (1) targeting new devices and processes for commercialization by 2015 that are less expensive, more efficient, highly reliable, and environmentally benign; (2) collaborating with DOE OS/BES to conduct basic research targeting breakthroughs in key areas, such as ultra-high efficiency and/or ultra-low cost materials and devices.
BackgroundContrast-induced nephropathy is the leading cause of in-hospital acute renal failure. This side effect of contrast agents leads to increased morbidity, mortality, and health...Full Text Available
A wet air oxidation (WAO) process was applied to four selected pharmaceuticals (metoprolol, naproxen, amoxicillin, and phenacetin) individually dissolved in ultra-pure water, varying the temperature and oxygen pressure. Due to the moderate (amoxicillin) or low (metoprolol, naproxen, and phenacetin) efficiency found in the oxidation of these pollutants, a catalytic wet air oxidation (CWAO) process was then tested using a platinum catalyst supported on multi-walled carbon nanotubes (CNT). In this CWAO process, the pharmaceuticals were dissolved together in ultra-pure water and in four natural water matrices-a reservoir water, a groundwater, and two waters from different municipal wastewater treatment plants. On the basis of the measurements of their removals, a discussion is given of the inf...
This paper deals with an experimental study of ultra-precision diamond cutting of magnesium alloy (AZ31). In order to investigate the machinability such as the cutting force and the surface integrity and understand the problems in a micro cutting, the experiments on the diamond cutting of magnesium alloy and pure aluminum with an ultra-precision turning machine has been carried out. The machinability of magnesium alloy was compared with that of pure aluminum and discussed. Consequently, both the thrust force component and the surface roughness obtained by cutting of magnesium alloy became larger than that of pure aluminum. It was also found that the inclusions or the defects in the work material caused to generate the scratches on the finished surface and influenced the integrity of mirror surface. (orig.)
The determination of the oxidation state of ultra-trace elements in the environment, especially in the case of actinides, is of importance in many ways. Speciation techniques using radiation may comprise methods based on the detection of the nuclear and atomic radiations emitted in radioactive decay or methods using external sources of excitation. In the former instance, information can be obtained from the energy and intensity of radiation, but at present the partition method is still the most commonly used, although its reliability is questionable. Excitation with intense laser beams, as is currently being used for trace element analysis in photoacoustic and thermal lensing spectroscopic techniques, could conceivably be applied under suitable conditions to ultra-trace elements with a sensitivity approaching that of the radiochemical methods.
A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (~;;10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10^13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.
An Ultra-Low-Carbon 19% Cr-11% Ni Stainless Steels used in nuclear fuel reprocessing plants where highly corrosion resistance in nitric acid is required has been developed. This steel has optimized the chemistry composition to decrease inclusions and deformation-induced martensitic transformation. The formation of deformation-induced martensite has the potential danger of accelerating corrosion in nitric acid. In this paper, effects of cold reduction and martensitic transformation on corrosion resistance of Ultra-Low-Carbon Stainless Steels in nitric acid are discussed. The developed steel showed excellent corrosion resistance during long-term exposure to nitric acid. (author).
Ultra-short-pulse reflectometry is studied by means of the numerical integration of a one-dimensional full-wave equation for ordinary modes propagating in a plasma. The numerical calculations illustrate the potential of using the reflection of ultra-short-pulse, microwaves as an effective probe of the density profile even in the presence of significant density fluctuations. The difference in time delays of differing frequency components of the microwaves can be used to deduce the density profile. The modification of the reflected pulses in the presence of density fluctuations is examined and can be understood based on considerations of Bragg resonance. A simple and effective profile-reconstruction algorithm using the zero-crossings of the reflected pulse and subsequent Abel inversion is demonstrated. The robustness of the profile reconstruction algorithm in the presence of a sufficiently small amplitude density perturbation is assessed.
In a previous survey we revealed uncertainty among responders about (a) whether or not to perform hemodialysis in patients with severely reduced renal function who had received contrast medium; and (b) when to perform hemodialysis in patients on regular treatment with hemodialysis or continuous ambulatory dialysis who received contrast medium. Therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and to issue guidelines. The committee performed a Medline search. Based on this, a report and guidelines were prepared. The report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy. Hemodialysis and peritoneal dialysis safely remove both iodinated and gadolinium-based contrast media. The effectiveness of hemodialysis depends on many factors including blood and dialysate flow rate, permeability of ...
In Nuclear Magnetic Resonance (NMR) imaging, contrast is dependent on the emission of radiofrequency waves by atomic nuclei, balanced by several parameters. The high information content of NMR images is due to the multiplicity of its parameters. However, this advantage introduces a difficulty in the interpretation of the contrast. There are three contrast parameters for each tissue: hydrogen nuclei density; relaxation time T1; relaxation time T2. Contrast may be enhanced towards any of these parameters by increasing the emission of radiowaves by atomic nuclei using particular pulse sequences.
Understanding human brain function, brain development and brain dysfunction is one of the great challenges of the twenty first century. Biomedical imaging has now run up against a number of technical constraints that are exposing limits to its potential. In order to overcome the current limits to high-field magnetic resonance cerebral imaging (MRI) and unleash its fullest potential, the Cea has built NeuroSpin, an ultra-high-field neuroimaging facility at its Saclay centre (in the Essonne). NeuroSpin already boasts three fully operational MRI systems. The first is a 3-tesla high-field system and the second is a very-high-field 7-tesla system, both of which are dedicated to clinical studies and investigations in humans, while the third is an ultra-high-field 17.65-tesla system designed for studies on small animals. In 2011, NeuroSpin will be commissioning an 11.7-tesla ultra-high-field system of unprecedented power that is ...
The advanced technologies of Ka-Band systems such as high gain spot .... sometimes used based on link requirements for a specific application. .... received at NASA LeRC from a Ku-band satellite and retransmitted to the USAT at Ka-Band. .... and to the Office of Management and Budget, Paperwork Reduction Project ...
A railgun has an armature driven between two rail-like conductors. In other words, it is a linear drive device system that drives airframes by using the Lorentz`s force. The system is expected as a next-generation high-speed transport means, or as a means to create such ultimate fields as ultra-high pressures, ultra-high temperatures, and ultra-ferromagnetic fields. This paper is a report on investigations on the relevant technological trends as surveyed by the investigation committee at the Institute of Electrical Engineers of Japan using research reports published inside and outside the country. The reported themes cover explanations from the construction to the pulse power supply that forms the core of the technology, problems in switching, recent status of research and development, and to application fields. Compatibility in the high-level electrical and mechanical performances demanded in the railgun is not as easy as ...
In order to understand how matter 15 billion years ago in the form of quarks, gluons and leptons at a temperature of 2 (times) 10(sup 12) (degrees)K evolved to become today's Universe, the goal of relativistic and ultra-relativistic heavy ion physics is t...
BackgroundMimivirus, a giant dsDNA virus infecting Acanthamoeba, is the prototype of the mimiviridae family, the latest addition to the family of the nucleocytoplasmic...Full Text Available
Iodized oil has been used as a contrast agent in lymphangiography. One of the commercially available compounds is Lipidol Ultra-fluid(LUF) which contains 38% iodine by weight. Nakakuma et al(1979) reported that LUF was selectively retained in the hypervascular hepatocellular carcinoma when injected directly into the ligated hepatic artery. Since that time, it has been widely utilized in the detection as well as the therapeutic attempts of hepatocellular carcinoma, where it has been mixed with chemotherapeutic agents or labeled with radioactive I-131. Like all significant advances, the mechanism of lipid retention within the hepatocellular carcinoma is not clearly understood, and also there is a lack of information about the biodistribution and kinetics of I-131 Lipiodol. The apparent safety of this technique require confirmation. The present study was aimed to assess the biodistribution and kinetics of intraarterially injected I-131 Lipiodol ...
Conventional gas-filled high voltage circuit breakers have the disadvantages of needing means to compress the arc-extinguishing gas and means for storing a significant amount of energy for operating the breaker. This invention has the object of providing a circuit breaker which does not need a gas compression means and whose energy of operation is very low. The principle of operation used in this circuit breaker consists of creating an arc voltage higher than that of the network. The difficulty of creating a high enough arc voltage in the SF{sub 6} gas normally used in a circuit breaker is resolved according to the invention by dividing the initial arc into a large number of elementary arcs by means of metal plates. The arc voltage of each elementary arc is from 20 to 40 volts, depending on the type of metal used. In a particular embodiment, the circuit breaker contains means for displacing the arc and giving it a solenoidal form. 11 figs.
For many years, {beta} radioactivity has been used to label molecules and follow them in various biological processes. {beta} imaging is obtained by autoradiography. Classically made on films or on photographic emulsions, autoradiography is now supplanted by radio-imagers which are very performing. The phosphor-imager, {beta}-imager and {mu}-imager are the systems mainly used today and their operating principles and properties are compared. The great advantages of these imagers are: their rapidity to obtain results and their reliability for absolute quantification. All emitters ({beta}{sup -}, {beta}{sup -} -{gamma} and {beta}{sup +}) are detectable as well as the gamma emitters of nuclear medicine, by means of their low energy electrons ejected during y emission. Phosphor-imager is well suited to energetic tracers and large series of experiments. Real time radio-imagers ({beta}-imager and {mu}-imager) are preferred to verify experimental conditions. The {beta}--imager and s-imager are ...
Increasingly stringent pollution regulations have spurred a broad interest in the reduction of engine emissions. Two strategies can be considered: after-treatment or engine emissions reduction. For Diesel engines, after-treatment has a high cost induced by the required technology and implementation issues. In this context, the Highly Premixed Combustion combustion mode (HP C) has emerged as a topic of major interest in recent years. It represents one of the most promising ways for new generation of CI engines using high Exhaust Gas Recirculation (EGR) rates. Experimentation on the test bench brought the proof of significant emission reduction. However, actual vehicle implementation implies frequent transient which fall far beyond steady state experimentation on the test bench. Several key challenges have to be addressed. With this combustion technology; accurate torque balancing at all engine modes is a requirement. Even slight unbalance between the cylinders can have dramatic ...
We have developed a transportable container based direct detection Doppler lidar based on the double-edge molecular technique. The pulsed solid state system was built at the University of Geneva. It was used to make range resolved measurements of the atmospheric wind field as part of the VALID campaign at the Observatoire de Haute Provence in Provence, France in July 1999. Comparison of our lidar wind measurements, which were analyzed without knowledge of the results of rawinsonde measurements made under the supervision of ESA, show good agreement with these rawinsondes. These are the first Doppler lidar field measurements made with an eyesafe direct detection molecular-based system at 355 nm and serve as a demonstrator for future spaceborne direct detection wind systems such as the Atmospheric Dynamics mission. Winds are an important contributor to sea surface temperature measurements made with the Tropical Rainfall Measuring Mission (TRMM) and also affect the ...
The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles...Full Text Available
Several fixed classification experiments test the hypothesis that F1, f0, and closure voicing covary between intervocalic stops contrasting...Full Text Available
Background and Objectives:Sound enamel manifests peak transparency in the near-IR (NIR) at 1310-nm, therefore the near-IR is ideally suited for high contrast imaging...Full Text Available
The passage of a vascular-injected paramagnetic contrast reagent (CR) bolus through a region-of-interest affects tissue 1H2O relaxation and thus MR image intensity. For longitudinal...Full Text Available
The distribution and activity of communities of sulfate-reducing bacteria (SRB) and methanogenic archaea in two contrasting Antarctic sediments were investigated. Methanogenesis dominated in freshwater...Full Text Available
Variation of CT units, in organs, before and after using contrast enhancing medium was reviewed and personal experience was presented. In the normal brain CT units was little changed by contrast enhancement (CE), whereas remarkable change was observed at lesions. No difference of CT units was observed between the normal liver and hepatomas. The normal kidney had higher CE effect than hypernephromas suggesting an increase of the sensitivity. CE was not found in cysts or necrosis. The changes of CT units in the cases of cerebral diseases are tabled with various contrast medium and scanners.
Double-contrast barium enema has a reduced sensitivity in patients with severe sigmoid diverticulosis. Therefore a carboxy methyl cellulose enema was employed after the conventional double-contrast examination in 15 patients with sigmoid diverticulosis. A significant increase in lumen diameter and a superior removal of barium residue from the diverticulas facilitated the interpretation of the sigmoid loops. Conclusion: The addition of methyl cellulose enema to double-contrast barium imaging improves diagnostic imaging in diverticulosis by expanding the lumen and emptying the diverticulas. (orig.).
Phase-contrast imaging with a practical cone-beam X-ray tube has been realized for clinical use in digital mammography using computed radiography (CR). To perform phase-contrast imaging, the X-ray detector must be distanced from an object so that the phase-contrast image achieves magnification; in a mammography unit dedicated to phase-contrast imaging, the magnification ratio is 1.75. When using an X-ray tube with a 0.1-mm focal spot, it appears that the penumbra in magnification blurs both projected images and the phase contrast, which generates an edge effect. However, where the sampling pitch of the CR plate is 43.75 {mu}m, the blur stretches the width of the phase contrast so that unit pixels in the detector can capture it. Note that the width of an ideal phase contrast using an X-ray point source results in a phase ...
Recently there has been growth, in interest in non-equilibrium interaction of half-period long optical pulses with matter. To date the optical pulses have been produced by chopping out a half-period long segment from a longer pulse using a semiconductor switch driven by a femtosecond laser. In this paper we present new methods for producing tunable ultra-short optical pulses as short as half an optical period using a free-electron laser driven by electron bunches with a duration a fraction of an optical period. Two different methods relying on the production of coherent spontaneous emission will be described. In the first method we show that when a train of ultra-short optical pulses as short as one half period. We present calculations which show that the small signal gain is unimportant in the early stages of radiation build up in the cavity when the startup process is dominated by coherent spontaneous emission. To support our proposed method ...
The advent, in the near future, of compact X-ray sources like Thomson Back-Scattering (TBS) will allow the clinical application of advanced X-ray imaging techniques, such as phase contrast, with higher sensitivity and lower impact in terms of dose delivery. In this work, we theoretically investigated the possibility of using such sources for phase contrast imaging of micro-calcifications included in a breast tissue. In our study we analyzed the phase and amplitude distribution of the TBS source and we showed that this source can be used for phase contrast imaging since the source coherence at the sample position is sufficiently high for achieving good contrast and micrometer spatial resolution. Indeed the spatial coherence of a TBS source is closer to that of a synchrotron radiation source, and much better than that of a laboratory source. Moreover, we showed the advantages of phase imaging with respect ...
There is a growing interest in using {sup 242m}Am as a nuclear fuel. The advantages of {sup 242m}Am as a nuclear fuel derive from the fact that {sup 242m}Am has the highest thermal fission cross section. The thermal capture cross section is relatively low and the number of neutrons per thermal fission is high. These nuclear properties make it possible to obtain nuclear criticality with ultra-thin fuel elements. The possibility of having ultra-thin fuel elements enables the use of these fission products directly, without the necessity of converting their energy to heat, as is done in conventional reactors. There are three options of using such highly energetic and highly ionized fission products. - Using the fission products themselves for ionic propulsion. - Using the fission products in an MHD generator, in order to obtain electricity directly. - Using the fission products to heat a gas up to a high temperature for propulsion purposes. In this ...
The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU's evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky trademark pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of ...
In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P{sup +}/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B{sup +} and BF{sub 2}{sup +} ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF{sub 3} as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit ...
In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P"+/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B"+ and BF_2"+ ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF_3 as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit coming from PLAD ...
Ultra-luminous infrared galaxies are among the most luminous objects in the local universe and are thought to be powered by intense star formation. It has been shown that in these objects the rotational spectral lines of molecular hydrogen observed at mid-infrared wavelengths are not affected by dust obscuration, leaving unresolved the source of excitation of this emission. Here I report an analysis of archival Spitzer Space Telescope data on ultra-luminous infrared galaxies and demonstrate that star formation regions are buried inside optically thick clouds of gas and dust, so that dust obscuration affects star-formation indicators but not molecular hydrogen. I thereby establish that the emission of H_2 is not co-spatial with the buried starburst activity and originates outside the obscured regions. This is rather surprising in light of the standard view that H_2 emission is directly associated with star-formation activity. Instead, I propose ...
The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V{sub GS} = V{sub DS}/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted ...
The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V_G_S = V_D_S/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted in ...
A cell calculation code SLAROM-UF has been developed for fast reactor analyses to produce effective cross sections with high accuracy in practical computing time, taking full advantage of fine and ultra-fine group calculation schemes. The fine group calculation covers the whole energy range in a maximum of 900-group structure. The structure is finer above 52.5 keV with a minimum lethargy width of 0.008. The ultra-fine group calculation solves the slowing down equation below 52.5 keV to treat resonance structures directly and precisely including resonance interference effects. Effective cross sections obtained in the two calculations are combined to produce effective cross sections over the entire energy range. Calculation accuracy and improvements from conventional 70-group cell calculation results were investigated through comparisons with reference values obtained with continuous energy Monte Carlo calculations. It was confirmed that ...
We investigated the electrical characteristics and the junction depth of ultra-shallow junctions formed by using the plasma-doping method. Compared with ultra-low energy boron-ion implantation at 500 eV, the junctions formed with the plasma-doping process exhibited shallow junction depths and low sheet resistances. The junction depths of the plasma-doped samples were 150 A and 330 A after annealing for 10 s at 900 .deg. C and 950 .deg. C, respectively. For the same junction depth, the sheet resistance of the B{sub 2}H{sub 6} plasma-doped sample was an order of magnitude less than that of the 500-eV B-ion implanted sample. Cross-sectional transmission electron microscopy and deep level transient spectroscopy showed that the defects formed by the B{sub 2}H{sub 6} plasma-doping process could be removed by annealing at 950 .deg. C for 10 s. The scaling of metal-oxide-semiconductor field-effect-transistor (MOSFET) device channel lengths for ...
We investigated the electrical characteristics and the junction depth of ultra-shallow junctions formed by using the plasma-doping method. Compared with ultra-low energy boron-ion implantation at 500 eV, the junctions formed with the plasma-doping process exhibited shallow junction depths and low sheet resistances. The junction depths of the plasma-doped samples were 150 A and 330 A after annealing for 10 s at 900 .deg. C and 950 .deg. C, respectively. For the same junction depth, the sheet resistance of the B_2H_6 plasma-doped sample was an order of magnitude less than that of the 500-eV B-ion implanted sample. Cross-sectional transmission electron microscopy and deep level transient spectroscopy showed that the defects formed by the B_2H_6 plasma-doping process could be removed by annealing at 950 .deg. C for 10 s. The scaling of metal-oxide-semiconductor field-effect-transistor (MOSFET) device channel lengths for high-speed application ...
Objective: To determine the optimal contrast injection protocol for 64-MDCT coronary angiography. Materials and methods: One hundred and fifty consecutive patients scheduled to undergo retrospectively electrocardiographically gated 64-MDCT. Each 30 patients were assigned to use a different contrast protocol: group 1: uniphasic protocol (contrast injection without saline flush); group 2: biphasic protocol (contrast injection with saline flush); group 3A, 3B and 3C: triphasic protocol (contrast media + different saline diluted contrast media + saline flush). Image quality scores and artifacts were compared and evaluated on both transaxial and three-dimensional coronary artery images among each contrast protocol. Results: Among the triphasic protocol groups, group 3A (30%:70% contrast media-saline mixture was used in second ...
The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For protons or deuterons in the neighborhoods of surfaces of condensed matter metallic hydride cathodes, such conversions are determined in part by the collective plasma modes of the participating charged particles, e.g. electrons and protons. The radiation energy required for such low energy nuclear reactions may be supplied by the applied voltage required to push a strong charged current across a metallic hydride surface employed as a cathode within a chemical cell. The electroweak rates of the resulting ultra low momentum neutron production are computed from these considerations.
Tailor die quenching in the hot stamping of quenchable steel sheets was developed to produce ultra-high strength steel formed parts having strength distribution. Local portions of the heated sheet were quenched by holding grooved tools at the bottom dead centre during the stamping. Non-contact portions were generated in the sheet by grooving the tools, and thus the strength in the contact portions is high owing to the quenching and that in the non-contact portions is low owing to the lack of the quenching. Hat-shaped products having a tensile strength of approximately 1.5GPa only at four corners were formed.
Polyethylene (UHMWPE) wear in current knee prosthesis causes prosthesis loosening after no more than 15 years. In this work, a steady state one-dimensional lubrication model with non- Newtonian fluid, porous elastic layer on tibial component, ultra-filtration mechanism of fluid and some features of the surface roughness is studied through a numerical technique based on the Finite Element Method. The results show that the UHMWPE stiffness makes difficult the lubrication mechanism of the artificial joint and promotes abrasive and fatigue wear. Nevertheless, the use of compliant porous materials on the tibial component could reduce friction and wear. Moreover, the ultra-filtration mechanism promotes efficiency on the joint.
A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity RbCl product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant RbCl is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.
A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity RbCl product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant RbCl is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.
The conventional Calzination-Reduction-Carburization (CRC) process offers the potential to manufacture commercial WC powders with median SEM grain sizes below 0.5 pm (ultra fine grades). Strict process control and a high degree of automation have led to increased powder uniformity and high lot-to-lot reliability. The high potential and flexibility of the CRC process is shown by the development of tailor made WC powders with regard to subsequent alloy manufacturing. R and D powders have successfully been processed in full-scale units exhibiting SEM grain sizes of 0.15 - 0.20 pm. This paper discusses the powder characteristics of various ultra fine WC powder grades, stemming from the conventional CRC process. Analytical characterization include also field-emission SEM, bright field TEM, EDX analysis and XRD-line broadening. (author)
Mechanical properties of P-LDHA and V-ROL N steels of the Czech production are compared with other ultra-high strength steels produced in the world. The most important results can be summarized into following points: 1. Optimally heat treated P-LDHA steel exhibits substantially better strength characteristics then the V-ROL N steel. 2. Optimal tempering temperature of the P-LDHA steel is 300 C. 3. Basic mechanical properties of P-LDHA steel belong to the top of the UHS steels ranking and are well comparable with those of American 300 M steel. 4. In the low-cycle fatigue region, the P-LDHA steel exhibits slightly better fatigue resistance then the 300 M steel. On the other hand, the high-cycle fatigue resistance of 300 M steel is slightly better then that of the P-LDHA steel. (orig.)
This paper describes how hydrogen transport affects the severity of hydrogen embrittlement in 300 M and AerMet100 ultra high strength steels. Slow strain rate tests were carried out on specimens coated with electrodeposited cadmium and aluminium-based SermeTel 1140/962. Hydrogen diffusivities were measured using two-cell permeation and galvanostatic charging methods and values of 8.0 x 10{sup -8} and 1.0 x 10{sup -9} cm{sup 2} s{sup -1} were obtained for 300 M and AerMet100, respectively. A two-dimensional diffusion model was used to predict the hydrogen distributions in the SSR specimens at the time of failure. The superior embrittlement resistance of AerMet100 was attributed to reverted austenite forming around martensite laths during tempering.
We present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide under TE{sub 01} mode, performing switching by injecting carriers into the bulk silicon. Our current design uses a CMOS compatible process and the device was fabricated at SNF (Stanford Nanofabrication Facility). 300 ns switching time has been observed, while the switching speed can be improved further with 3-D device structure and faster driving circuit. Power handling capacity of the switch is at the level of 10 MW. The switch was designed for active X-band RF pulse compression systems--especially for NLC, but it is also possible to be modified for other applications and other frequencies.
In this paper, the design of large thin PIN detector with a membrane stress avoidance configuration is proposed, and the related device fabrication process is developed. Ultra-thin PIN detector {approx} 1.13 cm{sup 2} in area is fabricated on a thin ( {approx} 35{mu}m) silicon membrane, and characterized. Detector performance improvement has been successfully demonstrated. With the membrane stress avoidance design, the improved detector exhibits a leakage of 6nA, which is at least 5 times lower than that of detector of identical junction area. The new detector features a full depleted capacitance of 110 pF, and a FWHM of 40.86 keV energy resolution for 5.486 MeV alpha particle spectrography.
Bacterial cellulose produced by the gram-negative bacterium Gluconacetobacter xylinum was found to be an excellent native starting material for preparing shaped ultra-lightweight cellulose aerogels. The procedure comprises thorough washing and sterilization of the aquogel, quantitative solvent exchange and subsequent drying with supercritical carbon dioxide at 40 degreeC and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg cm-3 which is comparable to the most lightweight silica aerogels and distinctly lower than all values for cellulosic aerogels obtained from plant cellulose so far. SEM, ESEM and nitrogen adsorption experiments at 77 K reveal an open-porous network structure that consists of a comparatively high percentage of large mesopores and small...
The interpretation of solution hydrodynamic data in terms of macromolecular structural parameters is not a straightforward task. Over the years, several approaches have been developed to cope...Full Text Available
High and ultra-high strength steels for pipelines are produced by properly handling the steel microstructure. The metallurgical principles involved in the microstructure control are presented, with emphasis on TMCP processing, that comprises conventional controlled rolling followed by accelerated cooling. (author)
A cell calculation code SLAROM-UF was developed to improve calculation accuracy of effective cross sections for various fast reactor types. SLAROM-UF has a capability to calculate effective cross sections in ultra fine groups of about 100,000 below 50keV and in fine groups above the energy (maximum 900 groups). Resonance interaction among the fuel, the coolant, and the structure materials can be treated accurately even in a heterogeneous cell structure. Temperature can be set up freely in a cell by the ultra fine group calculation. Improvement in nuclear characteristics was observed in the analysis of JUPITER critical experiment, as 0.1% for criticality, 4% for sodium void reactivity, several % for radial reaction rate distribution, when SLAROM-UF was used instead of the typical cell calculation code. The effect of the ultra fine group calculation is remarkable in the non-leakage term of sodium void reactivity, and that of ...
Conference abstract book contains seven sections: Plenary-4 abstracts; Chemical-9 abstracts; Radiation-7 abstracts; Ultra Low Doses and Medicine-6 abstracts; Biomedical-11 abstracts; Risk Assessment-5 abstracts and Poster Sessions-25 abstracts. Each abstract was provided by the author/presenter participating in the conference.
Overcoming the limiting constraints of stimulated Raman scattering (SRS) and stimulated Brilluoin scattering (SBS) poses serious fibre design challenges for increasing the output power of optical amplifiers and lasers. New fibre amplifier designs are proposed to break out of these limitations to reach several kWs CW powers. (Author)
Channel plasmon polaritons (CPPs) propagating along the bottom of subwavelength grooves cut into a metal surface were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realisation of ultra-compact photonic components. Here, the results of our investigations of CPP guiding by V-grooves cut into gold are presented, demonstrating efficient large-angle bending and splitting of radiation as well as waveguide-ring resonators and Bragg grating filters.
The invention relates to a pulsed laser ablation method of metals and/or dielectric films from the surface of a wafer, printed circuit board or a hybrid substrate. By utilizing a high-energy ultra-short pulses of laser light, such a method can be used to manufacture electronic circuits and/or electro-mechanical assemblies without affecting the material adjacent to the ablation zone.
By means of an audio frequency plasma polymerisation ultra-thin gradient plasma polymer layers were deposited on zinc and zinc-coated iron. The aim was to generate an interfacial polymeric layer which bonds to an oxidised metal as well as to a subsequently applied organic coating and acts as an interfacial barrier layer for ions and water. Surface modifications were done in an in situ plasma cell with infrared reflection absorption spectroscopy (IRRAS). The zinc surface was first activated by an oxygen plasma to provide a freshly oxidised and contamination free oxide surface. The intermediate stages of the surface reactions could be revealed. Carbon dioxide molecules as oxidation products adsorbed on the growing zinc oxide and were desorbed at a later stage. An organosilicon plasma polymer was deposited directly on top of the oxide layer from a hexamethyldisilane (HMDS) plasma. Afterwards a cyclohexene (CHEX)/hexamethyldisilane co-plasma polymer was deposited. The ...
Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed. (author).
Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed.
A method based on the collection of [sup 99]Tc from 500 l sea water samples by anion exchange and further extraction of TcO[sub 4][sup -] into 5% triisooctylamine-xylene has been improved to include a decontamination factor 6.5x10[sup 5] for uranium. The detection limit for [sup 99]Tc is thereby reduced to 3 mBq/m[sup 3].
An 'electron-bridge' mechanism of nuclear reaction in an atom or ion by ultra-intense laser fields is presented. A preliminary estimate of the intensity dependence of the rate of disintegration reaction of deuteron nucleus in deuterium atom is made for 800 nm laser fields. For intensities below 5x1021 W/cm2, the rate of disintegration by the 'electron-bridge' mechanism is found to be small, but it rises sharply and becomes large already for ?1022 W/cm2.
We present two new techniques that enhance conventional focused ion beam (FIB) system capabilities for integrated circuit (IC) analysis: in situ electrical biasing and voltage contrast imaging. We have used in situ electrical biasing to enable a number of advanced failure analysis applications including (1) real time evaluation of device electrical behavior during milling and deposition, (2) verification of IC functional modifications without removal from the FIB system, and (3) ultraprecision control for cross sectioning of deep submicron structures, such as programmed amorphous silicon antifuses. We have also developed FIB system voltage contrast imaging that can be used for a variety of failure analysis applications. The use of passive voltage contrast imaging for defect localization and for navigation on planarized devices will be illustrated. In addition, we describe new, biased voltage contrast ...
Objective To investigate value of magnetic resonance cholangiopancreatography (MRCP) using oral diluted gadolinium (Gd)-diethylenetriamine penta-acetic acid (DTPA) as negative contrast materials in diagnosis of juxtapapillary duodenal diverticulum with atypical imaging features. Methods Nineteen patients with juxtapapillary duodenal diverticula of which imaging findings were atypical underwent MRCP using oral diluted Gd-DTPA as negative contrast materials after conventional MRCP without any oral contrast materials. Results Twenty diverticula were revealed in the 19 patients. At conventional MRCP, the diverticula appeared as rounded lesion with high signal intensity. After oral administration of diluted Gd-DTPA, they disappeared at MRCP. These entities were diagnosed as duodenal diverticula...
Abstract The authors provide a survey of how images are used in radiation therapy to improve the precision of radiation therapy plans, and delivery of radiation treatment. In contrast...Full Text Available
The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte...Full Text Available
BackgroundIt is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission...Full Text Available
Fuji Computed Radiography (FCR) utilizes imaging plates of scanning lazer stimulated luminescence. FCR can be used for intravenous digital subtraction angiography (IVDSA) and for intraarterial studies because of tis high contrast and spatial resolution. Pixel size of the imaging plates for angiography is 0.2 mm. Experimentally, it could demonstrate a vessel 1 mm in diameter with a contrast of 0.1, when opacified with a contrast medium of 3 % iodine concentration, and could image a vessel 3 mm in diameter with contrast of 0.1, when opacified with 1 % contrast medium. A 20 % stenosed portion of a vessel 3 mm in diameter was identified when opacified with 3 % contrast medium, and a 20 % stenosed portion of a vessel 2 mm in diameter was identified when opacified with 10 % contrast medium. In 105 IVDSA examinations of 75 patients, FCR was ...
Purpose To investigate the influence of timolol maleate 0.5% gel-forming solution and brinzolamide 1% ophthalmic suspension on contrast sensitivity, ocular higher-order aberration (HOA), and corneal surface light scattering. Design Prospective, comparative study. Participants Forty normal volunteers were enrolled in this study. Methods We evaluated contrast sensitivity, ocular HOA, and corneal light scattering before and 2, 5, 10, and 15 minutes after instillation of antiglaucoma eyedrops. Contrast sensitivity function was assessed with the CSV-1000RN chart (Vector Vision Co., Greenville, OH). Higher-order aberration was measured for a 4-mm pupil using the Hartmann-Shack aberrometer (KR-9000PW; Topcon, Tokyo, Japan). Corneal surface light scattering was quantitatively evaluated by using th...
In contrast to the increasing availability of information pertaining to the care of children with chronic kidney disease (CKD) from large-scale observational and interventional studies, epidemiological...Full Text Available
Emerging evidence indicates that impaired cellular energy metabolism is the defining characteristic of nearly all cancers regardless of cellular or tissue origin. In contrast to normal cells, which...Full Text Available
CT of the gastrointestinal tract is commonly performed after administration of a high-density diluted iodinated oral contrast material. However, because if inadequate mixing of the contrast material with the gastrointestinal contents, pseudotumor and poor mucosal visualization are frequently shown on abdominal CT. To overcome these problem, 10% corn oil emulsion (COE) is tested as an alternative oral contrast agent in 40 patients. We analyse patients tolerance, gastric mucosal visualization and discrimination of pancreas from the duodenal C-loop to 10% COE in 40 patients compared with those obtained from 35 patients, who was received high-density diluted iodinated oral contrast agent (gastrografin). The results are as follows : 1. Patients' tolerance to 10% COE is similar to that to conventional oral contrast agent. 2. Image of the gastric mucosa from patients receiving 10% ...
CT of the gastrointestinal tract is commonly performed after administration of a high-density diluted iodinated oral contrast material. However, because if inadequate mixing of the contrast material with the gastrointestinal contents, pseudotumor and poor mucosal visualization are frequently shown on abdominal CT. To overcome these problem, 10% corn oil emulsion (COE) is tested as an alternative oral contrast agent in 40 patients. We analyse patients tolerance, gastric mucosal visualization and discrimination of pancreas from the duodenal C-loop to 10% COE in 40 patients compared with those obtained from 35 patients, who was received high-density diluted iodinated oral contrast agent (gastrografin). The results are as follows : 1. Patients' tolerance to 10% COE is similar to that to conventional oral contrast agent. 2. Image of the gastric mucosa from patients receiving 10% COE is ...
The aim of this work is to develop an industrial process for the synthesis of an extrusible electrolyte polymer for lithium batteries. From literature data and precise specifications the high molar mass EO/OP copolymers synthesis by coordinative catalysis has been studied in order to reach a high productivity and to minimize the treatment steps. Two catalytic systems have been studied: the aluminium alkoxide-based Vandenberg-type catalysis and the calcium alcoholate amides catalysis. The first catalysis performed in solution gives excellent results. Its adaptation to silicon supported catalysis leads to a directly usable polymer in suspension but the productivity falls down and remains to be optimized. The calcium amide catalysis in heptane suspension generates acceptable productivities but also a too high proportion of low molar masses. Various approaches have been studied to minimize this proportion due to the presence of secondary sites that generate a cationic mechanism. The two ...
The aim of this study concerns the use of numerical methods for the resolution of the Reynolds Averaged Navier Stokes equations adapted to the simulation of the cooling of the trailing edge of a stator in a high pressure turbine. These methods, based on the elsA solver developed at ONERA, use a four steps Runge Kutta time discretization scheme and a Jameson centered space discretization scheme. The scheme is applied through a finite volume approach on control volume centered on the cells of a multi-block structured mesh. Turbulence is simulated either through the algebraic Michel model, or through the one-transport-equation Spalart-Allmaras model, or through the two-transport-equations k 1, k {omega} and k {epsilon} models, and through ASM model. A simulation of the flow in a bidimensional stator, without cooling, is carried out. The cooling, which is realized with trailing edge slots, is then simulated on a bidimensional stator. Because the slot is represented by meshes overlapping ...
Durability of 28 days compressive strength concrete of 20 to 120 MPa has been studied. The ability of concrete to transport aggressive agents has been determined for four properties: the air permeability, the chloride diffusivity, the water absorption and the carbonation. A chloride migration test for high and very high strength concrete (HSC and VHSC) has been built. The relationship between transport properties and the compressive strength after one and 28 days of humid curing has always the same shape: transport decreases when strength increases. However, transport properties often vary in the ordinary concrete field. Beyond, the domain is much more limited. The relationship between transport properties and strength valid for ordinary concrete can not be simply extrapolated for HSC and VHSC. To determine the part of microcracking of HSC and VHSC, concrete behaviour stored in two mediums has been studied: the ones shaming the storing condition of concrete in auto-desiccation, the ...
The increasing complexity of the real-time data acquisition and processing systems (TDAQ: the so called Trigger and Data AcQuisition systems) in high energy physics calls for an appropriate evolution of development tools. This work is about the interplay between in principle specifications of TDAQ systems and their actual design and realization on a concrete hardware and software platform. The basis of our work is to define a methodology for the development of TDAQ systems that meets the specific demands for the development of such systems. The result is the detailed specification of a 'methodological framework' based on the Unified Modeling Language (UML) and designed to manage a development process. The use of this UML-based methodological framework progressively leads to the setting up of a 'home-made' framework, i.e. a development tool that comprises reusable components and generic architectural elements adapted to TDAQ systems. The main parts of ...
The aim of this work is to account for the effects of the high temperature oxidation of metals on their microstructure and their mechanical properties. 'Model' materials like pure nickel, pure iron and the Ni-20Cr alloy are studied. Nickel foils have been oxidised at 1000 C on one side only in laboratory air, the other side being protected from oxidation by a reducing atmosphere. After the oxidation treatment, the unoxidized face was carefully examined by using an Atomic Force Microscope (AFM). Grain boundaries grooves were characterised and their depth were compared to the ones obtained on the same sample heat treated in the reducing atmosphere during the same time. They are found to be much deeper in the case of the single side oxidised samples. It is shown that this additional grooving is directly linked to the growth of the oxide scale on the opposite side and that it can be explained by the diffusion of the vacancies produced at the oxide scale - metal interface, ...
An accident of misidentification has brought to light the interesting system HD 191588, a new RS CVn-type spectroscopic binary. A radial-velocity study of the primary star, the only seen component, carried out at the Observatoire de Haute-Provence with the Coravel instrument and subsequently at the Cambridge Observatories with a similar one, reveals two orbital motions: a short-period orbit (60 days) and a long-period one (about 4.5 years), so this star is a triple system. The following orbital elements are obtained: (1) for the long-period orbit P = 1667+/-17 days, T = 50901 +/-67 MJD, Gamma = +2.09 +/-0.07 km/s, K = 2.51 +/-0.13 km/s, e = 0.18 +/-0.04, omega = 228deg +/- 14 deg, a1 sin i = 56.7 +/- 3.0 Gm, f(m) = 0.0026 +/-0.0004 M_sun, and (2) for the short-period orbit P = 60.0269 +/-0.0016 days, T = 50482.6 +/-3.3 MJD, gamma is var., K = 24.03 +/- 0.09 km/s, e = 0.012 +/-0.004, omega = 233 deg +/-19deg, a1 sin i = 19.83 +/-0.07 Gm, f(m) = 0.0865 +/-0.0009 ...
Gadolinium (Gd) based contrast agents (GBCAs) in magnetic resonance imaging (MRI) are used in daily clinical practice and appear safe in most patients; however, nephrogenic systemic fibrosis...Full Text Available
An analyzer-based X-ray phase-contrast imaging (ABI) setup has been mounted at the Brazilian Synchrotron Light Laboratory (LNLS) for multiple imaging radiography (MIR) purposes. The algorithm employed for treating the MIR data collected at LNLS is described, and its reliability in extracting the distinct types of contrast that can be obtained with MIR is demonstrated by analyzing a test sample (thin polyamide wire). As a practical application, the possibility of studying ophthalmic tissues, corneal sequestra in this case, via MIR is investigated.
We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.).
A method for elucidating complex abnormalities of CSF circulation by using a positive contrast medium (metrizamide) and computer tomography is described. The technique for the method, the results and their clinical significance is demonstrated. The value of this method is compared with traditional ventriculography and with computer tomography without the use of contrast medium. It is shown that the technique represents an important extension of the scope of computer tomography.
Gold and silver nanoparticles display extraordinarily large apparent refractive indices near their plasmon resonance (PR) wavelengths. These nanoparticles show good contrast in a narrow spectral band but are poorly resolved at other wavelengths in differential interference contrast (DIC) microscopy. The wavelength dependence of DIC contrast of gold/silver nanoparticles is interpreted in terms of Mie's theory and DIC working principles. We further exploit this wavelength dependence by modifying a DIC microscope to enable simultaneous imaging at two wavelengths. We demonstrate that gold/silver nanoparticles immobilized on the same glass slides through hybridization can be differentiated and imaged separately. High-contrast, video-rate images of living cells can be recorded both with and without illuminating the gold nanoparticle probes, providing definitive probe identification. Dual-wavelength ...
Purpose: To evaluate contrast-enhanced CT scan in the diagnosis of intrahepatic cholangiocarcinoma by correlating the CT appearance with pathologic specimens. Materials and methods: Twenty-eight patients with pathologically proven intrahepatic cholangiocarcinoma were examined. Unenhanced abdominal CT study were performed in 28 patients; conventional contrast-enhanced CT in 27 patients. Enhanced CT scan including fast injection, fast scan and delayed scan at the largest section of the lesion was done in 7 patients. Contiguous 10 mm CT scans of the surgical specimens were also obtained in 8 patients. The preoperative and specimen CT scans in these 8 patients were compared with the corresponding pathological sections. A total of 103 areas of the pathological sections was compared with the CT appearances. Results: All lesions contained areas of delayed contrast enhancement and/or no enhancement on CT examinations. The areas of ...
This report summarizes the findings of a five-month LDRD project funded through Sandia's NTM Investment Area. The project was aimed at providing the foundation for the development of advanced functional materials through the application of ultrathin coatings of microporous or mesoporous materials onto the surface of substrates such as silicon wafers. Prior art teaches that layers of microporous materials such as zeolites may be applied as, e.g., sensor platforms or gas separation membranes. These layers, however, are typically several microns to several hundred microns thick. For many potential applications, vast improvements in the response of a device could be realized if the thickness of the porous layer were reduced to tens of nanometers. However, a basic understanding of how to synthesize or fabricate such ultra-thin layers is lacking. This report describes traditional and novel approaches to the growth of layers of microporous materials on silicon wafers. The ...
This paper describes high speed rolling and gauge control in cold tandem mill for ultra-thin gauge strip at the Chiba Works of Kawasaki Steel Corporation. To improve the plate-out property of rolling oil, cationic polymeric coagulant was prepared. Rolling oil with cohesion independent of inorganic inclusions or phosphatide was developed, to improve the lubrication for cold rolling, remarkably. In addition, a low-cost Ti-enhanced work roll having high wear resistance and excellent grindability was developed. Rolling can be conducted at the optimal rolling roughness and operation can be performed at the highest rolling speed independent of the rolling treatment amount. Rolling speed at 2800 m/min was confirmed by developing the rolling oil with excellent lubrication and the work roll having high wear resistance. For the improvement of strip thickness accuracy at the steady state rolling, use of the backup roll as roller bearing was more effective rather than the ...
Potassium atoms in selected high-lying np Rydberg states (80 #<=# n #<=# 400) are being used as a tool to examine electron-polar molecule collisions at ultra-low energies (#approx#80 #mu#eV - 1 meV). This energy regime has not been investigated previously and is of interest because the corresponding electron de Broglie wavelength is large, #approx#1300 - 330 Angstrom, and because the collision time is comparable to the period of molecular rotation. A variety of target molecules has been studied, including simple rotors such as HF, and more complex species such as NH_3, CH_3I, CH_2Br_2 and C_6H_5NO_2. These targets encompass a range of dipole moments and rotational behavior, but analysis of the data shows that in each case the cross section #sigma#(#epsilon#) for rotationally-inelastic electron-polar molecule scattering varies approximately as 1/#epsilon# where #epsilon# is the electron energy. Such threshold behavior is not predicted by the Born approximation ...
Fluorine is known to have a beneficial role for the B diffusion reduction in preamorphized Si, and is promising for the realization of ultra-shallow junctions. Thus, we studied the F incorporation in Si during the solid phase epitaxy (SPE) process, pointing out the effects of the implanted F energy and fluence and the role played by the possible presence of dopants. The incorporation of fluorine proceeds by F segregation at the amorphous-crystalline interface, with a kinetics driven by the SPE rate. In fact, the quicker the SPE rate, the higher is the F fluence retained. Moreover, we demonstrated that F incorporated in Si layers does not appreciably affect the Is emission from spatially separated end-of-range (EOR) defects. The modification, induced by the presence of F, of the point defect density (Is and Vs) was also studied by means of B and Sb spike layers, used as local markers for Is and Vs, respectively. We showed that F is not only able to completely ...
In an attempt to enhance the electrical and mechanical properties of the high temperature superconducting oxides, high T(sub c) composites were prepared composed of the 123 compounds and AgO. The presence of extra oxygen due to the decomposition of AgO at high temperature is found to stabilize the superconducting 123 phase. Ag is found to serve as clean flux for grain growth and precipitates as pinning center. Consequently, almost two orders of magnitude enhancement in critical current densities were also observed in these composites. In addition, these composites also show much improvement in workability and shape formation. On the other hand, proper oxygen treatment of Y5Ba6Cu11Oy was found to possibly stabilize superconducting phase with T(sub c) near 250 K. I-V, ac susceptibility, and electrical resistivity measurements indicate the existence of this ultra high T(sub c) phase in this compound. Detailed structure, microstructure, electrical, magnetic and thermal ...
We have investigated and modeled the boron diffusion in silicon following ultra-low-energy implantation (500 eV). It is well known that reducing implant energies is an effective way to eliminate transient enhanced diffusion due to the excess of interstitials from the implant. However, for sub-keV B implants diffusion remains enhanced. This enhancement is linked to the presence of a silicon boride layer located at the silicon surface which creates interstitials. This phenomenon is named 'boron enhanced diffusion' (BED). The BED effect is of obvious interest since it counteracts the advantage obtained by reducing the ion implantation energy. For these reasons, we have investigated the diffusion of low-energy boron implanted in crystalline silicon and tested a complete simulation program, which takes into account the effect of boron precipitation and the effect of the silicon boride layer as a source of self-interstitials. Experimental results have ...
Supermetal with critical characteristics is under advanced investigation for further improvement of metal materials. Although iron is most frequently used as structural material among various metals, it should be used more carefully and effectively because of resource limitation and global environmental problem. It is essential to draw various excellent properties much more from iron and to improve recyclability. In particular, the best way to meet these requirements is achievement of more fine structure and higher purity. Since the lowest crystalline grain size is now limited to nearly 10{mu}m, metallic structure composed of grains below 1{mu}m is expected by mesoscopic control. Various methods have been studied to achieve ultra-fine crystalline structure, and study of precise heat treatment control and ultra-strength metallurgy is required. Heat treatment in magnetic field and layered structure by mechanical alloying are also promising. ...
Gamma-ray burst (GRB) is one of the candidates of high-energy cosmic-ray acceleration sites. They may be also ultra-high-energy (above 3 EeV) cosmic-ray (UHECR) sources. In this paper, we discuss possibilities and implications of high-energy cosmic-ray acceleration in GRBs. (1) First, we show that not only protons but also heavier nuclei can be accelerated up to ultra-high energies in both usual high-luminosity (HL) and low-luminosity (LL) GRBs by using the Geant4. LL GRBs may also make a significant contribution to the observed UHECR flux if they form a distinct population, and we investigate cosmic-ray acceleration in LL GRBs in detail. (2) Second, we discuss implications of the GRB-UHECR hypothesis (and Hypernova-UHECR hypothesis) to cosmic-ray astronomy. HL GRBs and LL GRBs will lead to different source number densities as UHECR sources, so that the determination of the number density of UHECR sources and strength of the mean extragalactic ...
Gemini North adaptive optics imaging spectroscopy is presented for the Galactic ultra-compact HII (UCHII) region K3-50A. Data were obtained in the K-band using the Near-infrared Integral Field Spectrograph (NIFS) behind the facility adaptive optics module ALTAIR in natural guide star mode. The NIFS data cube reveals a complex spatial morphology across the 0.1 pc scale of the 3'' UCHII region. Comparison of the nebular emission to Cloudy ionization models shows that the central source must have an effective temperature between about 37000 K and 45000 K with preferred values near 40000 K. Evidence is presented for sharp density variations in the nebula which are interpreted as a clearing of material nearest the central source. High excitation lines of FeIII and SeIV show that the ionization of the nebula clearly changes with distance from the central source. A double lobed kinematic signature (+/- 25 kms) is evident in the Br gamma line map which may be related to ...
A 19.1 metre wind turbine blade was subjected to static tests. The purpose of the test series was to verify the abilities of different types of sensors to detect damage in wind turbine blades. Prior to each of the static test-series an artificial damage was made on the blade. The damage made for each test-series was surveyed during each series by acoustic emission, fiber optic micro bend displacement transducers and strain gauges. The propagation of the damage was determined by use of ultra sonic and X-ray surveillance during stops in the test series. By use of acoustic emission it was possible to measure damage propagation before the propagation was of visible size. By use of fiber optic micro bend displacement transducers and strain gauges it was possible to measure minor damage propagation. By use of both ultra sonic, and X-ray NDT-equipment it were possible to determine the size of propagated damage. (au)
In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics demonstrated that the ...
In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics demonstrated that the ...
Experimental discussions were given on effect of V and W addition on the high temperature strength properties of 12% Cr-15% Mn austenite steels. The test samples were added with W at 0% to 3.5% and V at 0% to 0.5% in addition to C and N, and were given aging treatment or solution treatment. This paper describes the following matters on the results of high-temperature strength measurements and structural observation: A remarkable trend was observed that M23 Cb type carbides precipitate in the aging treatment, wherein aging hardening appears prominently which is attributable to ultra-fine deposits of vanadium nitride (VN) in the V-added material; the V addition is very effective in increasing the high-temperature tensile strength and creep fracture strength as compared with single W addition, wherein the said carbides that accelerate the precipitation as a result of the V addition make a large contribution, in addition to that by ultra-fine VN ...
In the development of the specific mathematical modeling for heavy and ultra heavy petroleum fractions in a molecular distiller is very important the definition of physical and chemical parameters as density and specific heat of the mixture, the enthalpy of vaporization, among others, since they are used in the energy balance. Information on these properties and their variation with temperature are found in the open literature for mixture with few components (simple mixtures). However, for multicomponent solutions consisting of complex mixtures such as oil and its heavy and ultraheavy fractions, available data are few, or are limited to low temperatures. The specific heat is an important property in the energy balance. This property can be measured by Differential Scanning Calorimetry (DSC), which gives results with great sensitivity and accuracy. This paper presents the variation of specific heat with the temperature of ultra-heavy oil ...
In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray photoelectron spectroscopy is reported for both the as-deposited and ...
We report measurements for coherent rho^0 production, AuAu->AuAu rho^0, and coherent rho^0 and e^+e^- pair production accompanied by mutual nuclear Coulomb excitation, AuAu->Au*Au* rho^0 and AuAuee, in ultra-peripheral relativistic gold-gold collisions (UPC). We discuss transverse momentum, mass, and rapidity distributions. The two photon-process of e^+e^- pair production is an important probe of strong field QED because of the large coupling Z*alpha=0.6. At sqrt{s}=200GeV, the e^+e^- production cross section agrees with lowest order QED calculations. The cross sections for coherent rho^0 production at sqrt{s}=130 and 200GeV are in agreement with theoretical predictions. The calculations for both, coherent e^+e^- and rho^0 production treat nuclear excitation as independent process.
An extremely sensitive stripping voltammetric procedure for ultra-trace determination of iridium(III) is reported. The method is based on the interfacial accumulation of the iridium(III)-CTAB complex onto the glassy carbon electrode, followed by the catalytic reduction of the adsorbed complex in the presence of bromate. 0.3molL^-^1 acetate buffer pH 4.7+6.9x10^-^2molL^-^1 NaBrO3+2.7x10^-^5molL^-^1 cetyltrimethylammonium bromide (CTAB)+0.2molL^-^1 KCl was employed as the supporting electrolyte. The analytical procedure was verified by the analysis of the standard reference materials: Sea Water BCR-CRM 403 and Fresh Water NIST-SRM 1643d. The accuracy, expressed as relative error e%, was satisfactory, being lower than 6%, while precision as repeatability, expressed as relative standard deviat...
The object of this research is the evaluation of the performance of ultra high speed relays (UHSR's) used for protection of a-c transmission lines. For purposes of this report, these are relays whose response time is less than a quarter of a cycle of the 60 Hz wave (i.e. 4.167 ms.). To identify relaying schemes that may comply with this definition, a literature survey was undertaken. The selected relays were studied in detail and modeled on a digital computer. A theoretical description of these relays is presented. Records of real transient data as well as of simulated data were used as input to the digital models of relays. The real data were recorded by means of monitoring stations connected to the Florida Power and Light Company transmission lines. The simulated data were obtained by modeling the relevant parts of the utility's transmission system using a University of British Columbia simplified version of the well known Electromagnetic ...
The main driver in ultra-shallow formation for the 65 nm technology node and beyond is to find solutions that both reduce boron transient enhanced diffusion and can be integrated in the CMOS process flow. To this end, many studies have recently focused on using co-doping techniques with fluorine and most recently with carbon. In most cases, one or both of these is co-implanted with a dopant specie in pre-amorphized silicon. In this work, we show a comparative study of fluorine or carbon co-implanted with low-energy boron to form source and drain extension junctions for PMOS devices. We will show that by a systematic optimization of germanium, boron, fluorine or carbon energies and doses, spike annealing technology can be extended to the 65 nm node. These results will be used to discuss how the different formed junctions offer potential solutions for either low-power or high-performance PMOS device fabrication.
Overhead persistent surveillance systems are becoming more capable at acquiring wide-field image sequences for long time-spans. The need to exploit this data is becoming ever greater. The ability to track a single vehicle of interest or to track all the observable vehicles, which may number in the thousands, over large, cluttered regions while they persist in the imagery is very desirable. Typically, this imagery has many thousands of pixels on a side and is characterized by lower resolutions (e.g. {approx}0.5 meters/pixel to {approx}2.0 meters/pixel) and lower frame rates (e.g. {approx} sub-Hz to several Hz). We describe our ultra-scale capable implementation of a multiple-vehicle tracking algorithm for overhead persistent surveillance imagery. This work builds upon an earlier report, where now the algorithm has been modified for improved performance and has been substantially improved to handle much larger datasets in a much shorter time.
A nuclear battery based on the direct energy conversion of the fission products is presented. Such energy conversion is possible by using a nuclear reactor with ultra-thin fuel elements of 0.2 {mu}m of {sup 242m}Am. The amount of nuclear fuel is 376 g and the dimensions of the battery are 2.4x2.4x2.4 m{sup 3} (including the vacuum spacing), with a BeO moderator and Be electrodes. The total power of the reactor is 10.6 MW and the electrical power is 0.652 MW.
There is growing interest in using {sup 242m}Am as a nuclear fuel for space reactors and nuclear batteries. In this paper, we discuss different {sup 242m}Am enrichments, as well as fuel weight requirements, to produce a critical reactor. It was found that relatively low enrichments of {sup 242m}Am, about 10 w/o, are enough to guarantee criticality. Such low enrichments might eliminate the need for a {sup 242m}Am enrichment process. It was also found that the best results for low {sup 242m}Am requirements are obtained with a moderator to fuel volume ratio of 10,000.
This is a study done in collaboration with Deidre Hunter at Lowell Observatory studying star formation in two luminous spiral galaxies NGC 801 and UGC 2885. We used ultra-deep H? images taken at the KPNO 2.1 m telescope. We compare these data to stellar images at various wavelengths and to HI maps to determine the extent of star formation activity into the outer disk in these galaxies and its relationship to the gas and older stars. TW is grateful for an REU internship during the summer of 2010 at Northern Arizona University, funded by NSF through grant AST-1004107.
Energy deposition process by relativistic fast electrons produced by ultra-intense laser pulses is discussed. The process is calculated with a two dimensional Fokker-Planck simulation code including binary and collective collisions coupled with electromagnetic field. We focused on Velocity Distribution Function (VDF) dependence in the simulation. The results show that the spread angle of the fast electrons distribution affects energy deposition area and deposited energy is concentrated in the vicinity of the propagation axis of the fast electrons. It may be also suggested that self-pinch effect of a fast electron beam causes large deposition energy. (author)
This feature articles described a concept and technical problems of geological disposal of high-level radioactive waste in the civil engineering. It consists of six papers such as the present statues and subjects of geological disposal by KITAYAMA Kazumi, the diastrophism, igneous activity, and upheaval and erosion by YAMAZAKI Haruo, the groundwater flow and evaluation of nuclear transfer by IJIRI Yuji, evaluation of alteration of cement materials in the ultra-long period by HAGA Kazuko, The Mizunami Underground Research Laboratory in course of construction by SAKAMAKI Masanori, and interview of the ninetieth president of JSCE (Japan Society of Civil Engineers), he places his hope on JSCE and civil engineers by KISHI Kiyoshi. (S.Y.)
Zeolite Y is the active component of most commercial cracking catalysts. Interaction of H[sub 3]PO[sub 4] with extraframework aluminum of ultra-stable zeolite (USY) leads to the formation of different types of aluminum phosphates, while there is no indication of the formation of SAPO zeotype structures. The total acidity of USY slightly decreases upon the H[sub 3]PO[sub 4] treatment, while the maximum in the distribution of acid strength is shifted to milder acidities. Dealumination of the zeolite and creation of POH sites associated with AIPO[sub 4] are responsible for the modifications observed. 37 refs., 8 figs., 3 tabs.
We are investigating a novel insulator concept which involves the use of alternating layers of conductors and insulators with periods less than 1 mm. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We present our ongoing studies investigating the degradation of the breakdown electric field resulting from surface roughness, the effect of gas pressure, and the performance of the insulator structure under bi-polar stress. Further, we present our initial modeling studies.
In this paper it is described how a martensitic steel sheet with tensile strength of 1400 MPa is heat treated locally. The sheet is then formed in the heat treated regions in a way that would be impossible with the untreated material. Mechanical properties and forming limit diagrams of the heat treated material are determined and the forming operations are simulated, which shows that the method can be used by designers. Although the method has been known for decades, it remains to be industrialised and the work presented here is to be seen as a contribution to this development. (orig.)
Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that the performance of absorption and desorption systems can be ...
In the quest to understand the ultimate nature of WIMPs, we propose the use of a hybrid detection technique: cylinders filled with liquefied noble gasses, acting as targets, are immersed inside a tank of Gd-doped ultra-pure water that provides an active and efficient veto against neutrons. The evaluation of the background rejection capabilities and physics potential of this instrument have been carried out through a full GEANT4 simulation, assuming the detector will be located at the Canfranc underground laboratory (in the Spanish Pyrenees). Our results compare very favourably with existing or planned experiments in the field. This technique is scalable and will allow to reach target masses of few tonnes in the next future.
When searching for anisotropies in the arrival directions of Ultra High Energy Cosmic Rays, one must estimate the number of events expected in each direction of the sky in the case of a perfect isotropy. We present in this article a new method, developed for the Auger Observatory, based on a smooth estimate of the zenith angle distribution obtained from the data itself (which is essentially unchanged in the case of the presence of a large scale anisotropy pattern). We also study the sensitivity of several methods to detect large-scale anisotropies in the cosmic ray arrival direction distribution : Rayleigh analysis, dipole fitting and angular power spectrum estimation.
It is shown that all contracting, spatially homogeneous, orthogonal Bianchi cosmologies that are sourced by an ultra-stiff fluid with an arbitrary and, in general, varying equation of state asymptote to the spatially flat and isotropic universe in the neighbourhood of the big crunch singularity. This result is employed to investigate the asymptotic dynamics of a collapsing Bianchi type IX universe sourced by a scalar field rolling down a steep, negative exponential potential. A toroidally compactified version of M*-theory that leads to such a potential is discussed and it is shown that the isotropic attractor solution for a collapsing Bianchi type IX universe is supersymmetric when interpreted in an 11-dimensional context.
It is reported about the adsorptive stripping voltammetric determination of uranium, antimony, tin, vanadium and molybdenum using chloranilic acid as complex forming reagent. The determination limits are in the l{sup 1}-range. (orig.) [Deutsch] Es wird ueber die Bestimmung von Uran, Antimon, Zinn, Vanadium und Molybdaen durch Adsorptions-Stripping-Voltammetrie mit Chloranilsaeure als Komplexbildner berichtet. Die Bestimmungsgrenzen liegen im ng l{sup -1} Bereich. (orig.)
Ultra High Vacuum (UHV) test setup for electron gun testing has been developed. The development of next generation light sources and accelerators require development of klystron as a radio frequency power source, and in turn electron gun. This UHV electron gun test setup can be used to test the electron guns ranging from high average current, quasi-continuous wave to high peak current, single pulse etc. An electron gun has been designed, fabricated, assembled and tested for insulation up to 80 kV under the programme to develop high power klystron for future accelerators. Further testing includes the electron emission parameters characterization of the cathode, as it determines the development of a reliable and efficient electron gun with high electron emission current and high life time as well. This needs a clean ultra high vacuum to study these parameters particularly at high emission current. The cathode emission current, work function and ...
Scanning ion microscopy with polarization analysis (SIMPA) is used to study the spin-resolved surface magnetic structure of nano-sized magnetic systems. SIMPA is utilized for in situ topographic and spin-resolved magnetic domain imaging as well as for focused ion beam (FIB) etching of desired structures in magnetic or non-magnetic systems. Ultra-thin Co films are deposited on surfaces of Si(1 0 0) substrates, and ultra-thin, tri-layered, bct Fe(1 0 0)/Mn/bct Fe(1 0 0) wedged magnetic structures are deposited on fcc Pd(1 0 0) substrates. SIMPA experiments clearly show that ion-induced electrons emitted from magnetic surfaces exhibit non-zero electron spin polarization (ESP), whereas electrons emitted from non-magnetic surfaces such as Si and Pd exhibit zero ESP, which can be used to calibrate sputtering rates in situ. We report on new, spin-resolved magnetic microstructures, such as magnetic 'C' states and magnetic vortices, found at surfaces of ...
Current dewatering methods for ultra-fine coal suspensions are inadequate and usually require subsequent expensive thermal drying. This unique dewatering method is based on pressurized electroosmosis, the movement of water by an electrical field through a porous medium, under modest pressure, e.g., 110 psi. More ultra-fine coal can be utilized since an effective dewatering process can be realized by combining known filtration techniques with electroosmosis. The dewatering efficiency can be significantly improved, the residual moisture of the cake can be substantially reduced and handling problems can be eliminated. Bench-scale testing is being used to optimize the parameters which influence pressurized electroosmotic dewatering (PED) of ultra-fine coal suspensions. Particle size distribution is being addressed to obtain a maximum density for a given pressure such that pore saturation is maintained allowing electroosmosis to ...
Our objective was to evaluate the feasibility of ultra-low-dose scanning for multislice CT colonography in the detection of colorectal lesions. Twenty-seven patients (14 men, 13 women) with clinical indication for conventional colonoscopy were recruited. Multislice spiral CT (Somatom Plus 4 Volume Zoom, Siemens, Germany) examinations were performed after standard oral colonoscopic preparation and colonic distension with room air. Images were acquired using 2.5-mm collimation, 3.0-mm slice thickness, standard reconstruction kernel, 140 kVp, and 10 mAs. Supine and prone acquisitions were obtained in all patients. Images were analyzed on a workstation by two gastrointestinal radiologists. Conventional colonoscopy was performed on the same day in all patients and represented the standard of reference. Total radiation exposure was also calculated. All colorectal cancers were correctly identified at CT colonography (9 of 9, sensitivity 100%). The CT colonography also ...
A computed tomography (CT) cut-off for differentiating neoplastic lesions (polyps/carcinoma) from normal colon in contrast-enhanced CT colonography (CTC) relating to the contrast phase and lesion size is determined. CT values of 64 colonic lesions (27 polyps <10 mm, 13 polyps {>=}10 mm, 24 carcinomas) were determined by region-of-interest (ROI) measurements in 38 patients who underwent contrast-enhanced CTC. In addition, the height (H) of the colonic lesions was measured in CT. CT values were also measured in the aorta (A), superior mesenteric vein (V) and colonic wall. The contrast phase was defined by xA + (1 - x)V using x as a weighting factor for describing the different contrast phases ranging from the pure arterial phase (x=1) over the intermediate phases (x=0.9-0.1) to the pure venous phase (x=0). The CT values of the lesions were correlated with their height ...
In a fluoroscopic imaging system, image quality and patient dose are both affected by the optical system linking the image intensifier with the video camera. The effect on patient exposure of increasing the optical iris aperture size over that required for other procedures performed on the same imaging system was investigated for the air-contrast barium enema examination. Using a large-area transmission ionisation chamber to monitor the Roentgen-area-product of entrance exposure, a decrease in fluoroscopic radiation of greater than 50% was clinically documented for a fluoroscopic system utilising kVp and mA variable automatic brightness control. For this iris change, the video image was of acceptable quality for positioning and monitoring the patient, and no deleterious effect was detected in the conduct of the air-contrast exam. The availability of a variable-sized operator-selectable iris diaphragm would permit this dose-reduction approach to ...
Magnetization transfer contrast (MTC) on fast spin echo (FSE) images was evaluated in normal brain tissue as well as in brain tumors to better understand contrast of FSE images. On multislice FSE images, attenuation of the signal intensity of brain tissue due to MTC is observed. The rate of MTC (MTR) is obtained by comparing with additional single slice images. The effect of signal attenuation is greater on images with smaller interslice gap, larger number of slices, and longer echo train length. MTR of brain tumors is less than that of normal brain tissue. Among them, meningiomas have relatively high MTR, and cavernous malformation has relatively low MTR. Determination of MTC can be easily specified by obtaining multislice and single slice FSE images, and it may help differentiate brain tumors. (author).
Purpose We evaluated low-contrast injection protocols for coronary computed tomography angiography (CTA) using a 64-detector scanner and the test bolus technique. Materials and methods We randomly assigned 60 patients undergoing coronary CTA to one of two contrast material (CM) injection protocols. For the lowcontrast dose protocol (Plow), the patients received injections of iohexol-350 [0.7 ml/kg body weight (BW)] during 9 s, and the test-bolus technique was used. Under the conventional protocol (Pconv), they received iohexol-350 (1.0 ml/kg BW) during 15 s, and bolus tracking was used. We compared the protocols for attenuation values in the ascending aorta and coronary arteries and for the amount of CM required. Results There was no significant difference in the mean CT attenuation of the...
Purpose: To compare the diagnostic quality and adverse events of the water-soluble, non-ionic, iso-osmolar, dimeric contrast media iodixanol and iotrolan in hysterosalpingography (HSG). Material and Methods: One hundred and twenty patients participated in a double-blind randomized parallel-group phase-III study. Questionnaires and patient interviews were used. Diagnostic quality was assessed using a visual analogue scale and the quality in specific regions was rated using a categorical scale. Results: Overall diagnostic quality was equal for the two groups. There was no statistically significant difference between the two groups in diagnostic quality in the specific regions of interest. No differences between the contrast media were found with regard to adverse events. Conclusion: Both contrast media provided images of high diagnostic quality in HSG. (orig.)
Active contrast material extravasation can be recognized with conventional CT scanners, though it has been considered a rare finding. Helical CT seems to increase the detection rate and especially to boost the radiologist's confidence in this diagnosis. Though active bleeding is defined in severely-injured subjects requiring urgent intervention and may be associated with findings of hypovolaemic shock, it should not be considered itself as a negative prognostic factor. Contrast extravasation is due to ongoing hemorrhage and its detection is critical for urged treatment. Accurate anatomical location permits to choose surgical management or transcatheter embolization and thus decreases time consumption for precis e bleeding site identification.
Gelatine is a reliable tissue simulant in wound ballistic experiments. The projectile penetrating the gelatine transfers energy and causes radial cracks according to the temporary cavity. Thus the crack length is a function of the energy spent in the medium. In practice the fissures are poorly contrasted for which reason an enhancement of contrast was searched. A series of six shoots with expanding bullets (9mmx19 Action-5, 9mmx19 Quick Defense 1, 5.56mmx45 Styx Action) was realized on 10% gelatine blocks at 4^oC temperature. Three blocks were marked with acryl paint on the front, three blocks were shot native. The blocks were cut in slices of 1cm thickness and optically scanned. The evaluation was performed according to Fackler's wound profile, the total crack length method and the polygo...
Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1 mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a potential for medical application of this ...
BackgroundIn humans, myocardial infarction is characterized by irreversible loss of heart tissue, which becomes replaced with a fibrous scar. By contrast, teleost fish and urodele...Full Text Available
The purpose of this study was to synthesize biocompatible polyvinylpyrrolidone (PVP)-coated iron oxide (PVP-IO) nanoparticles and to evaluate their efficacy as a magnetic resonance imaging (MRI)...Full Text Available
Background: In North America and Europe, 80% of invasive skin cancers are basal cell carcinoma while 20% are squamous cell carcinoma (SCC). In contrast, African studies reveal a preponderance...Full Text Available
The anatomy of the labyrinth and the structure of the macula utriculi of the teleost fish (burbot) Lota vulgaris was studied by dissection, phase contrast, and electron microscopy....Full Text Available
Trichloroethylene (TCE) is both acutely toxic and carcinogenic to the mouse lung following exposure by inhalation. In contrast, it is not carcinogenic in the rat lung and is markedly less toxic following...Full Text Available
Mice and rats are important mammalian models in biomedical research. In contrast to other biomedical fields, work on sexual differentiation of brain and behavior has traditionally utilized comparative...Full Text Available
A new strain of mouse hepatitis virus (MHV) was isolated from pooled gut suspensions from an epizootic of lethal enteritis in newborn mice. Negative-contrast electron microscopy showed an abundance...Full Text Available
We investigated a method of analyzing the hemodynamics of the lung mass by contrast enhanced dynamic computed tomography (dynamic CT) to determine the difference in vascular supply between the pulmonary artery and bronchial artery using an experimental model. Our experimental model consisted of two injectors connected to two tubes, representing the pulmonary artery and bronchial artery, which were further connected to a chamber representing the lung mass. Following infusion of contrast medium into each tube with some delay time, dynamic CT scans were performed to obtain time density curves of the two tubes and the chamber. Using the time-density curve of contrast passage, flow rates from the two tubes into the chamber were calculated by the curve fitting method. Calculated values correlated well with the adopted flow rates of fluid from the injectors (r=0.893) in the experiment. The results indicate our method of ...
We investigated a method of analyzing the hemodynamics of the lung mass by contrast enhanced dynamic computed tomography (dynamic CT) to determine the difference in vascular supply between the pulmonary artery and bronchial artery using an experimental model. Our experimental model consisted of two injectors connected to two tubes, representing the pulmonary artery and bronchial artery, which were further connected to a chamber representing the lung mass. Following infusion of contrast medium into each tube with some delay time, dynamic CT scans were performed to obtain time density curves of the two tubes and the chamber. Using the time-density curve of contrast passage, flow rates from the two tubes into the chamber were calculated by the curve fitting method. Calculated values correlated well with the adopted flow rates of fluid from the injectors (r=0.893) in the experiment. The results indicate our method of ...
Anatomical specimens and normal persons were studied by gradient echo MR imaging to determine the influence of different echo times (TE) on bone marrow contrast. First of all, six normal persons were studied to determine specific echo times for in-phase and opposed-phase states. Using different sequences bone marrow contrast in isolated femoral bones was determined and compared to results of pathological exams. Red bone marrow had no signal on opposed-phase images; contrast between red and yellow marrow was higher on opposed-phase than on in-phase images. Bone marrow lesions can be expected to be visualised with high signal on opposed-phase images; this technique should be especially suited for MR imaging of bone marrow. (orig.).
ObjectiveUsing high resolution cardiovascular magnetic resonance (CMR), we aimed to detect new details of left ventricular (LV) systolic and diastolic function, to explain the twisting...Full Text Available
We have characterized the kinetic response of gene targets throughout the murine genome to transcriptional modulation by the glucocorticoid receptor (GR). In contrast to a model in which multiple genes...Full Text Available
BackgroundCavernous hemangiomas are the most frequent neoplasms of the liver and in routine clinical practice they often need to be differentiated from malignant tumors and other...Full Text Available
Iodixanol is a new nonionic dimer, isotonic with blood at all clinically relevant concentrations. Iodixanol (270 mg I/ml) was compared in a double-blind, randomized, parallel-group, phase-III study to the monomeric nonionic iohexol (300 mg I/ml) for evaluation of safety, tolerability and radiographic efficacy during cerebral CT. One hundred adult patients scheduled to undergo contrast-enhanced cerebral CT were randomly allocated to receive either iodixanol or iohexol. All completed the trial. Safety was evaluated by recording discomfort and other adverse events, tolerance by assessing intensity and incidence of discomfort. Radiographic efficacy was assessed from the diagnostic information and the radiographic density. No serious adverse events occurred. One patient (2 %) in the iodixanol group and one patient (2 %) in the iohexol group experienced a transient reddening at the neck and lower neck-line, respectively. Both contrast agents were ...
... protein is abundant in cytosolic portions of malignant epithelial tissue (Fig. 3A). In contrast, the degree of CCTβ staining in normal epithelial tissue (Fig. 3B) or connective tissues was much weaker ......
Spinocerebellar ataxia 10 (SCA10) is an autosomal dominant disease caused by large-scale expansions of the (ATTCT)n repeat within an intron of the human ATXN10 gene. In contrast...Full Text Available
RATIONALE AND OBJECTIVESNon-invasive longitudinal imaging of tumor vasculature could provide new insights into the development of solid tumors, facilitating efficient...Full Text Available
Little change was observed in primates fed 75 mg/kg adenine over the four-week period. Minimal tissue pathology was encountered upon completion of the study. In contrast to earlier studies in which oral feeding of adenine to dogs caused severe symptoms, a...
Background:There is a need for simple imaging parameters capable of predicting therapeutic outcome.Methods:This retrospective study analysed 50 patients...Full Text Available
AIM: To improve the diagnosis of heterotopic pancreas by the use of contrast-enhanced computed tomography (CT) imaging and CT virtual endoscopy (CTVE).METHODS: A total of six patients with heterotopic...Full Text Available
Objective. For the multislice CT (MSCT) systems with a larger number of detector rows, it is essential to employ dose-reduction techniques. As...Full Text Available
Low kVp settings provide high conspicuity of contrast materials at CT but may result in high image noise, particularly in larger patients. Material decomposition at dual energy CT can differentiate...Full Text Available
In voltage-gated Na+, K+, and Ca2+ channels, four voltage-sensor domains operate on a central pore domain in response to membrane voltage. In contrast, the voltage-gated...Full Text Available
NG2 chondroitin sulfate proteoglycan is a surface marker of oligodendroglial progenitor cells (OPCs) in various species. In contrast to well-studied rat OPCs, however, we found that purified...Full Text Available
BackgroundMost retinal ganglion cells (RGCs) convey contrast and motion information to visual brain centers. Approximately 2% of RGCs are intrinsically photosensitive (ipRGCs), express...Full Text Available
A focused ion beam (FIB) technique was applied to cross-sectional specimen preparation to observe an interface between a plasma sprayed coating and an aluminum (Al) substrate by transmission electron microscopy (TEM). The surface of the sprayed coating film has a roughness of several tens of microns. Sputter rates for the coating film and the substrate are greatly different. The rough surface and the difference in sputter rate cause problems in making TEM specimens with smooth side walls. The top surface of the coating film was planerized by the FIB before fabricating the TEM specimen. The interfaces were investigated by TEM and energy-dispersive X-ray (EDX) analysis. The TEM observation revealed that there is a 10 nm thick amorphous layer at the interface between the coating film and substrate. The coating film consists of two kinds of sublayers with bright and dark contrast. The bright contrast sublayers were amorphous layers with thickness ...
The extensive diversity of Plasmodium falciparum antigens is a major obstacle to a broadly effective malaria vaccine but population genetics has rarely been used to guide vaccine design....Full Text Available
The ability to adapt and respond to nutrients is an ancient cellular function, conserved from unicellular to the most complex multicellular organisms, including mammals. Mammals adapt to changes...Full Text Available
The mammalian neocortex consists of six layers. By contrast, the reptilian and avian cortices have only three, which are believed to be equivalent to layers I, V and VI of mammals. In mammals, the majority...Full Text Available
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
Colour television is examined as an attempt to imitate the human visual system in image formation, spectral sensitivities, adaptation, contrast effects, signal processing, signal modulation, signal...Full Text Available
Activatable or “smart” magnetic resonance contrast agents have relaxivities that depend on environmental factors such as pH or enzymatic activity, but the MR signal depends on...Full Text Available
It is well established that changes to the chemical environment can impair development, physiology and reproductive biology; by contrast, impacts on communication have not been widely reported. This...Full Text Available
Even in healthy individuals, aging leads to deterioration in visual acuity, contrast sensitivity, visual field, and dark adaptation. Little is known about the neural mechanisms that drive the...Full Text Available
Eighty-seven subtraction images of FCR were compared with subtraction images of conventional angiography. Although FCR images with reduced exposure dose (25 % of regular dose) and with diluted contrast material (150 mgI/ml, 50 % of usual concentration) were slightly inferior to the images of conventional angiography, most clinically important vessels were adequately visualized. As FCR has wider dynamic range and higher contrast resolution than conventional angiography, FCR may take over conventional angiography. (author).
The methods introduced for the field of cleaning waste water can be classified under various processes. Chemical oxidation is done with ozone, hydrogen peroxide and ultraviolet irradiation with subsequent biological decomposition. Another method is ultra-filtration with recovery of valuable materials or waste water ponds with algae biomass to decompose ammonium compounds, nitrates and phosphates. (EF) [Deutsch] Die auf dem Gebiet der Abwasserreinigung vorgestellten Methoden kann man in verschiedene Verfahren einordnen. Die chemische Oxidation erfolgt mit Ozon, Wasserstoff-Peroxid, UV Bestrahlung und anschliessenden biologischen Abbau. Eine andere Methode ist die Ultrafiltration mit Rueckgewinnung von Wertstoffen oder Abwasserteiche mit Algenbiomasse zum Abbau von Ammoniumverbindungen, Nitraten und Phosphaten. (EF)
The formation, migration and agglomeration in silicon of fluorine-vacancy complexes have been monitored by single-detector Doppler broadening spectroscopy. After electronics engineers found that fluorine ion implantation effectively eliminated the transient-enhanced diffusion of dopants in the creation of ultra-shallow junctions, a vital step in the further miniaturization of device structures, positron beams have played a pivotal role in providing an insight into the mechanisms underlying this phenomenon, being able to detect FV complexes in implanted and annealed samples. Secondary Ion Mass Spectrometry has provided complementary information on fluorine concentrations so that the nature of the F{sub m}V{sub n} complexes can be further assessed. New results on Si and SiGe structures are presented.
Faserbewehrter Beton wird heute zunehmend auch bei Tunnelbauwerken (Tunnelinnenschalen, Tubbinge) eingesetzt. Wesentliche Vorteile sind das hohe Tragvermogen, das daraus entstehende Einsparungspotential an herkommlicher stabformiger Bewehrung (Biegebewehrung, Bugelbewehrung in der Randzone), die Aufnahme von Spaltzugbeanspruchungen durch die Fasern, Rissbreitenbegrenzung, erhohte Dauerhaftigkeit, verbesserter Brandwiderstand (insbesondere bei Verwendung von Kunststofffasern), Optimierung der Arbeitsablaufe etc. Neue Entwicklungen in der Betontechnologie haben in den letzten Jahrzehnten den faserbewehrten ultrahochfesten Beton (engl. UHPFRC - Ultra High Performance Fibre Reinforced Concrete) hervorgebracht. Im Rahmen dieser Arbeit wird der Einsatz des ultrahochfesten, stahlfaserbewehrten Be...
The use of high-performance ion exchangers allows a trace-matrix-separation (SMT) directly followed by an ion chromatographic (IC) separation of the analytes. Based on the principles described in Part 1, a combined procedure IC-SMT-IC for metallic impurities in Mo and W is presented. Up to 12 metal traces (Fe, Cu, Pb, Zn, Ni, Co, Cd, Ca, Mn, Sr, Mg and Ba) can be determined in one run with 35 min. A special method for traces of U and Th is also given. Detection limits are typically 10-100 ng g{sup -1} in the metal sample. (author). 14 refs.; 10 figs.; 6 tabs.
A new high strength titanium alloy has been developed primarily intended for fastener applications. While Ti-6Al-4V is used extensively as a fastener alloy in the aerospace industry, its shear strength allowable is limited to 655 MPa (95 ksi). For higher shear strength requirements, various steels or nickel-based alloys are used (up to 860 MPa (125 ksi)), but with the attendant density penalty. This new alloy is intended to provide the 860 MPa shear strength at roughly a 40% weight savings. After screening various alloy systems, the optimum chemistry has been selected as follows: Ti-6.0V-6.2Mo-5.7Fe-3Al. In light of its 125 ksi shear strength goal, the alloy has been designated TIMETAL reg-sign 125.
The study aimed to determine the chemical effects on the K and L X-ray intensity ratios and the K and L X-ray production cross sections for gold compounds. The K shell fluorescence yields and L shell average yields were also investigated. The samples were excited by 59.5keV ?-rays from an 241Am annular radioactive source and 123.6keV ?-rays from a 57Co annular radioactive source. K and L X-rays emitted from samples were counted by an Ultra-LEGe detector with a resolution of 0.150keV at 5.9keV. The experimental values were compared with theoretical, the semi-empirical and other experimental values.
The conductive ultra thin films were fabricated from mixed monolayers containing stearic acid and Head-to-Tail poly(3-alkylthiophene). These films exhibited well-defined layered structures as determined by optical absorption and X-ray diffraction measurements. The UV-Vis absorption spectra of these films showed lower energy absorption shifts of 48 nm from that of the random poly(3-alkylthiophene)/stearic acid LB films. The blue shift of absorption maximum of the LB film is attributed to the increase of {pi}-conjugation length caused by no steric hindrance of alkyl side chains. The conductivity of the Head-to-Tail poly(3-hexylthiophene)/stearic acid LB films was greatly improved in the range of 67-100 S/cm. (orig.)
The goal of this research program is to determine whether pulsed laser deposition is an effective alternative method for growing TiCN thin films. Pulsed laser deposition (PLD) is chosen because of its well-documented capability for growing uniform, stoichiometric films in ultra-high vacuum or gaseous environments. Processing of thin films by PLD is also achieved at relatively low temperatures compared with CVD processing. Given these attributes, the primary objectives in this article are to determine whether nitrogen may be readily incorporated into films resulting from the laser-ablation of TiC in an N{sub 2} environment, determine what effect nitrogen has on mechanical properties, and determine whether nitrogen incorporation is strongly influenced by processes unrelated to laser deposition (e.g., thermally-activated surface reactions).
Accelerator mass spectrometry (AMS) represents a powerful technique for the detection of long-lived radionuclides through ultra-low isotope ratio measurements. In many cases, counting atoms rather than decays yields much higher sensitivities. The potential of AMS will be demonstrated on typical radionuclides of interest with half-lives between some tens of years up to a hundred million years. The precise measurement of the 27Al(n,2n)26Al excitation function will be exemplified. Lack of information exists for a list of nuclides as pointed out by nuclear data requests. A brief overview on detection limits and some applications for selected long-lived radionuclides is given.
After irradiation at 254nm of aqueous solutions of the antipsychotic drug flupentixol, the structures of the photodegradation products were determined by ultra high performance liquid-chromatography linked to mass spectrometry. Fragmentation patterns of the parent ions were established on a hybrid linear ion trap-orbitrap mass spectrometer allowing accurate mass measurements of both parent and daughter ions. This allowed to propose plausible structures for the main photolysis products of flupentixol. A total of nine photoproducts were detected after irradiation of the drug. The main photoproduct is generated following the addition of a hydroxyl group on the double bond adjacent to the thioxanthene ring. Secondary photoproducts were also observed.
A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function...
Pre-amorphization of ultrashallow implanted boron in Silicon-on-insulator is optimized to produce an abrupt box-like doping profile with negligible electrical deactivation and significantly reduced transient enhanced diffusion. The effect is achieved by positioning the as-implanted amorphous/crystalline interface close to the buried oxide interface, to minimize interstitials whilst leaving a single-crystal seed to support solid-phase epitaxy. Based on a simple physical model of our results, we estimate that the interface between the Si overlayer and the buried oxide is an efficient interstitial sink with a recombination length of the order of 10nm or less under our experimental conditions. (author)
The roughness length at air-sea interface during free convection (Z0fc) is mainly related to the convective velocity (w) rather than the friction velocity (u). The parameterization of Z0fc with (w)2/g as proposed by Abdella and D'Alessio (2003) is evaluated. It is shown that the field measurements at MM Lab, Tarapur Maharashtra Site (TMS) coastal site using Metek GmbH, Ultra sonic anemometers are consistent with the proposed formula. In order to avoid self-correlation by using u, a new parameterization of w with ?u and ?v and gustiness parameter as given by Fairall et al. (1996) is used. The mean values of w and Z0fc estimated using new parameterization were observed to be 0.97 m/s and 2.3E-4 m respectively for the year 2009 at TMS. (author)
Radiation damage is considered to be the major problem that still prevents imaging an individual biological molecule for structural analysis. So far, all known mapping techniques using sufficient short wave-length radiation, be it X-rays or high energy electrons, circumvent this problem by averaging over many molecules. Averaging, however, leaves conformational details uncovered. Even the anticipated use of ultra-short but extremely bright X-ray bursts of a Free Electron Laser shall afford averaging over 10^6 molecules to arrive at atomic resolution. Here we present direct experimental evidence for non-destructive imaging of individual DNA molecules. In fact, we show that DNA withstands coherent low energy electron radiation with deBroglie wavelength in the Angstrom regime despite a vast dose of 10^8 electrons/nm^2 accumulated over more than one hour.
Availability of a natural gas-powered van that meets California`s ultra low emission vehicle requirements and has a 300-km range was reported. A similar van with an electric system giving a range of 240 km was also within sight. Regarding the limitations of electric batteries it was suggested that a super capacitor may allow systems to achieve higher energy densities; a refuelable zinc-air battery could be considered for vehicle use. While the prospect for emissions improvement of gasoline vehicles has clearly improved in recent years, the relative costs of infrastructure, vehicle and fuel for the the alternative fuels compared with gasoline demonstrate the difficulty the alternative fuels have in taking market share from gasoline. For the next decade, gasoline, propane and CNG are expected to be the dominant fuels for vehicles. After that, the leading fuel will be the one that has been most extensively researched and developed during the decade. 17 refs.
Protein motions on all timescales faster than molecular tumbling are encoded in the spectral density. The dissection of complex protein dynamics is typically performed using relaxation rates determined at high and ultra-high field. Here we expand this range of the spectral density to low fields through field cycling using the nucleocapsid protein of the SARS coronavirus as a model system. The field-cycling approach enables site-specific measurements of R{sub 1} at low fields with the sensitivity and resolution of a high-field magnet. These data, together with high-field relaxation and heteronuclear NOE, provide evidence for correlated rigid-body motions of the entire {beta}-hairpin, and corresponding motions of adjacent loops with a time constant of 0.8 ns (mesodynamics). MD simulations substantiate these findings and provide direct verification of the time scale and collective nature of these motions.
Nanowires, films, and membranes comprising ordered porous manganese oxide-based octahedral molecular sieves, and methods of making, are disclosed. A single crystal ultra-long nanowire includes an ordered porous manganese oxide-based octahedral molecular sieve, and has an average length greater than about 10 micrometers and an average diameter of about 5 nanometers to about 100 nanometers. A film comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is stacked on a surface of a substrate, wherein the nanowires of each layer are substantially axially aligned. A free standing membrane comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is aggregately stacked, and wherein the nanowires of each layer are substantially axially aligned.
Ultra-thin, uniform, pinhole-free solid polymer electrolyte films having a fixed carboxylic ester group of approximately 1 {mu}m thickness were prepared by polymerization of methyl acrylate and tris(2-methoxyethoxy)vinylsilane in a glow discharge plasma. The carboxylic ester group of the plasma polymer were transformed to lithium carboxylate groups by treatment with lithium iodide. This process give a single lithium ion conductive film. These solid polymer electrolyte films showed ionic conductivities of the order of 10{sup -8} S cm{sup -1} (10{sup 4} {omega} cm{sup 2} resistance per unit area) at room temperature. (orig.).
ABSTRACT New observations from the Hubble Ultra Deep Field suggest that the star formation rate at Formula Not Shown drops off faster than previously thought. Using a newly determined star formation rate for the normal mode of Population II/I (PopII/I) stars, including this new constraint, we compute the Thomson scattering optical depth and find a result that is marginally consistent with Wilkinson Microwave Anisotropy Probe 5 results. We also reconsider the role of Population III (PopIII) stars in light of cosmological and stellar evolution constraints. While this input may be needed for reionization, we show that it is essential in order to account for cosmic chemical evolution in the early universe. We investigate the consequences of PopIII stars on the local metallicity distribution fu...
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional and multi-component seismic area is being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil-in-place will result in additional oil production by primary and enhanced recovery processes.
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil in place will result in additional oil recovery by primary and enhanced recovery processes.
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil in place will result in additional oil recovery by primary and enhanced recovery processes.
In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector.
The automotive industry desires to optimize safety and lightweight construction for the production of cars and trucks. The resulting task for steel suppliers is to make steel grades available that can fulfil these requirements. Different projects have shown optimistic outlooks for optimization of safety and reduction of the weight of automobile bodies by using different high strength and ultra high strength steels. In the last group the dual phase steels play the lead. In recent years different steel grades have been developed and optimized for these applications. On one hand developing the mechanical properties as well as joining and forming of dual phase steels is one of the first steps. On the other hand different coated surfaces for various applications of dual phase steels is another step. Starting with characteristic production conditions for cold rolled hot dip galvanised dual phase steels, the mechanical properties for joining and forming will be deduced ...
Discovery of better biomarkers for diagnosis, prognosis, and therapy-response prediction is the most critical task of a scientific quest aimed at developing newly designed, tailor-made therapies for patients with cancer. Consequently, a proteome wide analysis, in addition to genomic studies, is an absolute requirement for a complete functional understanding of tumor biology. Ultra-sensitive, high-performance Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) currently holds an important role in fulfilling the demands of biomarker discovery. In this review, we describe the applicability of FTICR MS for breast cancer proteomics, particularly for the analysis of complex protein mixtures obtained from a limited number of cells typically available from clinical specimens.
In this book over 250 alloys are organized by AISI number into 10 major sections: Irons, Carbon Steels, Alloy Steels, Low Alloy Constructional Steels, Ultra High Strength Steels, Tool Steels, Maraging Steels, Wrought Stainless Steels, Heat Resistnat Casting Alloys, and Iron Based Rought Superalloys. Each alloy record lists the designation, specifications, UNS number, composition, product forms and a comment on the high-temperature properties and applications. Referenced data is then given for physical properties such as density, specific heat, thermal conductivity, thermal expansion, electrical conductivity, Poisson's ratio, moduli of elasticity and rigidity, etc. Mechanical properties follow, and include tensile properties, shearing and bearing properties, impact properties, creep, stress rupture and stress relaxation and fatigue properties. The last part of the alloy record gives other effects of temperature, such as hot hardness, corrosion, and growth.
A qualitative method, involving supported liquid?liquid extraction (SLE) and ultra high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS?MS), was developed for the rapid tentative identification of various drugs of abuse in urine. In this study, 28 drugs and metabolites were covered by the screening procedure. Before analysis, urine samples were extracted by SLE and good extraction recoveries were obtained for most investigated compounds. The UHPLC strategy was then selected for the rapid separation of amphetamines, cocaine, opiates and related compounds in urine. Using columns packed with sub-2??m particles, analysis time was reduced down to 2?min, while maintaining acceptable performance. Finally, the detection was by tandem MS operating in the single reaction...
In many drug dispensing devices, such as syringes and inhalers, an elatomeric gasket is used to prevent the formulation from leaking from the chamber. During device actuation, the seal is subjected to friction, which in turn causes its deformation and can cause unintentional leakage, thus dose variability. Additionally, friction of seal is responsible for a host of potential problems such undue effort required for actuation and potential wear. The mechanism of friction generation in the seal conjunction is complex, arising from adhesion of rubber in contact with the moving interface, viscous action of a thin film of fluid and deformation of seal asperities. Therefore, the first step in understanding the conjunctional behaviour of rubber seals is a fundamental study of mechanisms of frictio...
Using ultra-high-frequency data extracted from the order flows of 23 stocks traded on the Shenzhen Stock Exchange, we study the empirical regularities of order placement in the opening call auction, cool period and continuous auction. The distributions of relative logarithmic prices against reference prices in the three time periods are qualitatively the same with quantitative discrepancies. The order placement behavior is asymmetric between buyers and sellers and between the inside-the-book orders and outside-the-book orders. In addition, the conditional distributions of relative prices in the continuous auction are independent of the bid-ask spread and volatility. These findings are crucial to build an empirical behavioral microscopic model based on order flows for Chinese stocks.
Development of a front end system for a high energy proton accelerator is in progress at Korea Atomic Energy Research Institute (KAERI) for basic science and industrial applications. The proper vacuum components has been installed and operated successfully between ion source and RFQ. The reliable operation of the accelerator has been completed at vacuum system in the high and ultra high vacuum range under operating conditions. Proper control system for the vacuum instruments, based on PC operated by Windows, has been designed and constructed by control group at PAL. As PC operated by windows with inherent instability does not proper, embedded system can be replaced for reliable operation system, such as VME system operated by vxWorks.
Objectives1. We will use reduction of lysosomal stability as an indicator of cell injury induced by C-60 fullerenes and carbon nanotubes in the liver analogue or digestive gland (hepatopancreas) of marine mussels. Molluscan hepatopancreatic digestive cells are key to normal function and are a sensitive key interface with the environment. Reduction of lysosomal stability is mechanistically linked with impaired health of the whole animal. 2. We will also test the hepatopancreatic digestive cells for evide [continued...]DescriptionNanotechnology is a major innovative scientific and economic growth area, which may present a variety of hazards for environmental and human health. The surface properties and very small size of nanoparticles and nanotubes provides surfaces that may bind and transport toxic chemical pollutants, as well as possibly being toxic in their own right by generating reactive oxygen species (ROS). There is a wealth of evidence for the harmful effects of nanoscale ...
The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)
The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)
At present the cooler synchrotron COSY a synchrotron and storage ring for medium energy physics is being commissioned at Juelich. The construction of the ring was finished during September 1992. The cooler ring will deliver protons in the momentum range from 270 to 3300 MeV/c. The phase density of the circulating protons will be increased with electron cooling at injection and with stochastic cooling at momenta between 1500 and 3300 MeV/c. High luminosity internal experiments as well as high resolution external experiments will be possible. Details of the lattice, to match the different ion optical requirements for cooling, acceleration, internal experiments and ultra-slow extraction will be discussed. An overview of the performance of the ion sources, the injector cyclotron, the ring, the injection beamline are given. The realization status of the extraction beamlines to the external experimental area is given. The experience on the commissioning of the cooler ...
Reducing implant energy is an effective way to eliminate transient enhanced diffusion (TED) due to excess interstitials from the implant. It is shown that TED from a fixed Si dose implanted at energies from 0.5 to 20 keV into boron doping-superlattices decreases linearly with decreasing Si ion range, virtually disappearing at sub-keV energies. However, for sub-keV B implants diffusion remains enhanced and x{sub j} is limited to {ge} 100 nm at 1,050 C. The authors term this enhancement, which arises in the presence of B atomic concentrations at the surface of {approx} 6%, Boron-Enhanced-Diffusion (BED).
In the present study, human neonatal fibroblasts were isolated from a two-month-old human male. The purpose of the present investigation was the analysis of the morphology (light and transmission electron microscopy), karyotype and growth characteristics of the human neonatal fibroblast cell culture B-HNF-1. Moreover, STR typing and mitochondrial DNA amplification and sequencing was also performed. Analysis of chromosomes count showed that B-HNF-1 cell culture is diploid and has normal male karyotype 46, XY, which was stable during cultivation. The transmission electron microscopy demonstrated the ultra-structure of the B-HNF-1 cells; they have typical morphological features of proteosynthesis-active cells. Large number of fibroblasts bearing different shapes and surface characteristics ad...
The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this PDR document and the set of SDD documents will define and ...
Recently the association of a rare disease named ''nephrogenic systemic fibrosis'' (NSF) with the administration of gadolinium-containing contrast media, especially gadodiamide (Omniscan, GE-Healthcare), was described. NSF is a scleroderma-like disease characterised by widespread tissue fibrosis. Until now, NSF cases were observed only in patients with kidney disease. Almost all patients were suffering from chronic renal insufficiency, 90 % of them required renal replacement therapy. The true incidence of the disease is unknown. First retrospective analyses of selected collectives of patients with end-stage renal disease showed 2 - 5 % cases of NSF after administration of Gadolinium-containing contrast agents with an odds ratio of 20 - 50 in comparison to non-exposed controls. NSF is a serious adverse reaction, which may result in severe disabilities and even death. Therefore all radiologists applying ...
The purpose of this study was to assess experimentally and clinically the usefulness of Fuji Computed Radiography (FCR) in angiographic examinations. FCR had a spatial resolution with much lower X-ray exposure doses, although the resolution of FCR was generally inferior to conventional films. When a contrast medium of 1% iodine concentration was used, FCR pinpointed a mass 1.5 mm in diameter; and conventional film could detect a mass 2.2 mm in diameter. The contrast of iodine in FCR examinations was stable. A high sensitivity of imaging plate allowed a wide range of visualization. In 148 selective angiographic examinatinons for 138 patients, FCR-subtraction images were superior to conventional film angiography for contrast resolution; it had a high sensitivity in detecting areas, such as the mediastimun and left lobe of the liver, and tumor stains in capillary phase. The capability of FCR arteriogram was as good as film ...
The purpose of this study was to assess experimentally and clinically the usefulness of Fuji Computed Radiography (FCR) in angiographic examinations. FCR had a spatial resolution with much lower X-ray exposure doses, although the resolution of FCR was generally inferior to conventional films. When a contrast medium of 1% iodine concentration was used, FCR pinpointed a mass 1.5 mm in diameter; and conventional film could detect a mass 2.2 mm in diameter. The contrast of iodine in FCR examinations was stable. A high sensitivity of imaging plate allowed a wide range of visualization. In 148 selective angiographic examinatinons for 138 patients, FCR-subtraction images were superior to conventional film angiography for contrast resolution; it had a high sensitivity in detecting areas, such as the mediastimun and left lobe of the liver, and tumor stains in capillary phase. The capability of FCR arteriogram was as good as film ...
The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated with ...
The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast{sup TM} 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated ...
The development of new steels is always a challenge for the manufacturer of filler metals. In many cases it is obvious that some properties of the base metal cannot be fulfilled with matching filler metals. In some cases, dissimilar filler metals can solve the problem in some cases, there is no chance to meet the requirements of the base metal (for example yield strengths of new ultra high strength steels). This paper deals with different kinds of new steels and the requirements for the weld metal with examples from motor car industry (Mangan Austenite), crane (Ultra high strength steels), earthmoving machinery (Wear-resistant steels) and offshore (Supermartensitic steels). Specific problems will be discussed and best solutions will be highlighted. These examples make clear that the success of new kinds of steels in the market depends on solving the joining problems of these steels. (Abstract Copyright [2007], Wiley Periodicals, Inc.) [German] ...
A sodium-water reaction drove from the single tube break in steam generator of FBR might overheat labor tubes rapidly under internal pressure loadings. If the temperature of tube wall becomes too high, it has to be evaluated that the stress of tube does not exceed the material strength limit to prevent the propagation of tube rupture. This study clarified the tensile and creep properties of Mod.9Cr-1Mo steel at ultra-high temperature which will be used in evaluation of the tube burst by sodium-water reaction. The strain rates for tensile test are from 10%/min to 10%/sec, and creep-rupture time is maximum 277sec. The range of test temperature is 700degC to 1300degC. The main results obtained were as follows; (1) The evaluation data on the relationship between tensile strength and strain rate and creep-rupture strength in shorter time on Mod.9Cr-1Mo steel were acquired. (2) Short-term mechanical properties of Mod.9Cr-1Mo steel were evaluated based on the results of ...
Research highlights: {yields} The use of resonant photoemission in its 'core-hole clock' expression for the study of the dynamical charge transfer across hybrid organic-inorganic interfaces and for the intermolecular charge transfer in the bulk of organic thin films is reviewed. {yields} The electronic coupling to the substrate and the efficiency of charge transport across hybrid interfaces is different for individual electronic subsystems of the molecular adsorbate. {yields} The intermolecular charge transfer in the bulk of discotic liquid crystals occurs on the order of a few femtoseconds and is faster than expected from the macroscopic charge transport characteristics of the material. -- Abstract: The focus of this brief review is the use of resonant photoemission in its 'core-hole clock' expression for the study of two important problems relevant for the field of organic electronics: the dynamical charge transfer across hybrid organic-inorganic ...
The high-strength and ultra high-strength steels developed and produced by Thyssen Krupp Stahl make a major contribution to automotive lightweighting. Proven and newly-developed coatings are used to meet increasingly important corrosion protection requirements. Design for materials, optimized forming and joining processes and the use of modern simulation techniques help to exploit the potential of the new steels. Future development work will focus on reducing the density of steels without compromising their well-known advantages - in particular their strength. The use of high-strength and ultra high-strength steels in the automotive industry is on the increase. Steel will remain the material of choice for auto manufacture, above all due to its potential for cost-efficient lightweight construction and its full recyclability. (orig.) [German] Einen wesentlichen Beitrag zum Leichtbau im Automobil leisten die von Thyssen Krupp Stahl entwickelten ...
A simple and rapid laser fluorometric determination of trace and ultra trace level of uranium in a wide variety of low uranium content materials like soil, basic and ultra basic rocks, plant ash, coal fly ash and red mud samples is described. Interference studies of some common major, minor and trace elements likely to be present in different geological materials on uranium fluorescence are studied using different fluorescence enhancing reagents like sodium pyrophosphate, orthophosphoric acid, penta sodium tri-polyphosphate and sodium hexametaphosphate. The accurate determination of very low uranium content samples which are rich in iron, manganese and calcium, is possible only after the selective separation of uranium. Conditions suitable for the quantitative single step extraction of 25 ng to 20 #mu#g uranium with tri-n-octylphosphine oxide and single step quantitative stripping with dilute neutral sodium pyrophosphate, which also acts as ...
The steroidogenic factor 1 (SF-1, also known as NR5A1) is a transcription factor belonging to the nuclear receptor superfamily. Whereas most of the members of this family have been extensively characterized, the therapeutic potential and pharmacology of SF-1 still remains elusive. Described here is the identification and characterization of selective inhibitory chemical probes of SF-1 by a rational ultra-high-throughput screening (uHTS) strategy. A set of 64,908 compounds from the National Institute of Health's Molecular Libraries Small Molecule Repository was screened in a transactivation cell-based assay employing a chimeric SF-1 construct. Two analogous isoquinolinones, ethyl 2-[2-[2-(2,3-dihydro-1,4-benzodioxin-7-ylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate (SID7969543) and ethyl 2-[2-[2-(1,3-benzodioxol-5-ylmethylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate and (SID7970631), were identified as potent submicromolar inhibitors, yielding ...
A comprehensive understanding of dopant activation mechanisms in crystalline Si is required in order to form shallow junctions. In this paper, we will review several experimental assessments on boron clustering and novel methods to form shallow junctions. Boron marker-layer structures have been used to investigate the fundamental aspects of formation and ripening boron-interstitial clusters (BICs) and their influence on the associated transient enhanced diffusion (TED). The samples were damaged by Si implants at different doses in the sub-amorphizing range and annealed at high temperatures. We found that BICs act as a sink for interstitials at supersaturations values S(t)>10{sup 4}. This implies that silicon self-interstitial defects are the primary source of interstitials driving TED, and that BICs act as a secondary 'buffer' for the interstitial supersaturation. These clusters are less sensitive to the ripening process than pure interstitial clusters do, so ...
Lipiodol Ultra-Fluid (Lipiodol) is widely applied in the transcatheter arterial embolization (TAE). We studied signal intensity, the T1 relaxation time and the T2 relaxation time of Lipiodol itself using Siemens Magnetom H15-2 T (1.5 Tesla) and Magnetom M10 (1.0 Tesla). Lipiodol showed higher signal intensity than saline solution on the T1-weighted images (short TR, short TE technique in spin echo method). On the T2-weighted images (long TR, long TE technique in spin echo method), Lipiodol showed lower signal intensity than saline solution. The T1 relaxation time of Lipiodol, measured at 1.0 T, was 201 msec and 218 msec at 1.5 T. The T2 relaxation time of Lipiodol, measured at 1.0 T, was 127 msec; and 167 msec at 1.5 T. The signal intensity of Lipiodol at 1.0 T was higher than the intensity at 1.5 T. Shorter T1 relaxation time of Lipiodol at 1.0 T is probably responsible for the higher intensity at 1.0 T. When MRI is performed after TAE with Lipiodol, the signal ...
The WEGA stellarator is used to confine low temperature, overdense (densities exceeding the cut-off density of the heating wave) plasmas by magnetic fields in the range of B=50-500 mT. Microwave heating systems are used to ignite gas discharges using hydrogen, helium, neon or argon as working gases. The produced plasmas have been analyzed using Langmuir and emissive probes, a single-channel interferometer and ultra-high resolution Doppler spectroscopy. For a typical argon discharge in the low field operation, B=56 mT, the maximum electron density is n{sub e}{proportional_to}10{sup 18} m{sup -3} with temperatures in the range of T=4-12 eV. The plasma parameters are determined by using Langmuir probes and are cross-checked with interferometry. It is demonstrated within this work that the joint use of emissive probes and ultra-high resolution Doppler spectroscopy allows a precise measurement of the radial electric field. The focus of this work is ...
The objective of this 3.5 year project is to develop a commercially competitive vehicle powered by ethanol (or ethanol blend) that can meet California`s ultra-low emission vehicle (ULEV) standards and equivalent corporate average fuel economy (CAFE) energy efficiency for a light-duty passenger car application. The definition of commercially competitive is independent of fuel cost, but does include technical requirements for competitive power, performance, refueling times, vehicle range, driveability, fuel handling safety, and overall emissions performance. This report summarizes a system design study completed after six months of effort on this project. The design study resulted in recommendations for ethanol-fuel blends that shall be tested for engine low-temperature cold-start performance and other criteria. The study also describes three changes to the engine, and two other changes to the vehicle to improve low-temperature starting, efficiency, and emissions. ...
To accomplish the environmental radiological surveillance need of India's ambitious nuclear power programme, Health Physics Division is infusing new technologies and improved analytical techniques for day to day measurements of various radionuclides in different environmental matrices. It is essential to have techniques for measuring the concentration of radionuclides just above the background level since the discharges from the nuclear facilities are very low i.e. in the range of 5-10% of the prescribed discharge limits by the regulatory bodies. In view of developing ultra-sensitive techniques, the aim of ongoing programmes of the division is to meet the challenges of measuring ultra trace level of radioactivity by adopting state of art new instrumentation and improved sample processing techniques. This will allow us to measure the lowest level of radioactivity (3H, 90Sr, 137Cs, 239+240Pu, etc.) in the environment and thereby estimating the ...
The theoretical analysis of a partially-ionized hydrogen gas flow (gas temperatures of approximately 10,000 to 20,000 K) through a particular class of magnetohydrodynamic (MHD) generators and the preliminary design of these MHD generators as open cycle, electric power supplies are performed. Analysis of the gas flow through these ultra-high temperature MHD generators requires a coupled gas dynamics/radiative heat transfer solution. Gas dynamics are modeled by a set of quasi-one-dimensional, nonlinear differential equations which account for friction, convective and radiative heat transfer and the interaction between the ionized gas and applied magnetic field. Radiative heat transfer is modeled using non-gray, absorbing-emitting two- and three-dimensional P-1 approximations which permit an arbitrary variation of the spectral absorption coefficient with frequency. Gas dynamics and radiative heat transfer are coupled through the energy equation, and through the ...
Superparamagnetic MFe{sub 2}{sup 3+}O{sub 4} (M=Mn{sup 2+}, Fe{sup 2+} and Co{sup 2+}) inverse spinel ferrite (ISF) nanoparticles with narrow size distribution having average diameters of 6-8 nm were synthesized by a diol reduction of organic metals and the surface was modified to be hydrophilic by coating with succimer. Magnetic resonance imaging (MRI) contrast enhancement by dipolar coupling defined interactions between the synthesized ISFs and protons in the bulk water was investigated with initial susceptibility, magnetization and anisotropy of the succimer-coated ISFs. The relaxivity ratios, r{sub 2}/r{sub 1}, for MnFe{sub 2}O{sub 4}, Fe{sub 3}O{sub 4} and CoFe{sub 2}O{sub 4} were measured to be 12.2, 23.1 and 62.3, respectively, which demonstrate the potential usefulness of these magnetic nanoparticles as T{sub 2} contrast agents for MRI.
Superparamagnetic MFe23+O4 (M=Mn2+, Fe2+ and Co2+) inverse spinel ferrite (ISF) nanoparticles with narrow size distribution having average diameters of 6-8 nm were synthesized by a diol reduction of organic metals and the surface was modified to be hydrophilic by coating with succimer. Magnetic resonance imaging (MRI) contrast enhancement by dipolar coupling defined interactions between the synthesized ISFs and protons in the bulk water was investigated with initial susceptibility, magnetization and anisotropy of the succimer-coated ISFs. The relaxivity ratios, r2/r1, for MnFe2O4, Fe3O4 and CoFe2O4 were measured to be 12.2, 23.1 and 62.3, respectively, which demonstrate the potential usefulness of these magnetic nanoparticles as T2 contrast agents for MRI.
X-ray imaging using asymmetric Bragg reflection in the hard x-ray regime opens the way to improve the spatial resolution limit below 1 #mu#m by magnifying the image before detection, simultaneously providing a strong phase contrast. A theoretical formalism of the imaging process is established. Based on this algorithm, numerical simulations are performed and demonstrate that both Fresnel propagation and Bragg diffraction contribute to contrast formation. The achievable resolution of this technique is investigated theoretically; the results obtained can be used to improve future experimental setups. Furthermore, the minimum detectable phase gradient is estimated, for comparison with other phase sensitive imaging techniques. Results from biological objects demonstrate that the technique is viable for imaging both in two and three dimensions. Refraction contrast images are extracted from experimental projection images by an ...
60 patients between 17 and 72 years of age were investigated. First, an enteroclysis was performed in typical manner. The applicated methylcellulosis was blended with positive oral MR contrast media (Magnevist oral, Schering). After enteroclysis, MRI of the abdomen was performed using T1- and T2-weighted breathhold sequences (Flash 2D pre- and postcontrast and TSE) in axial and coronal planes. The length of the affected bowel and the stenosis seen with enteroclysis correlated well with the visible thickening of the small bowel wall and the stenosis seen in MRI. Using MRI, additional findings could be obtained in 28 patients, such as fistulas, abscesses or a hydronephrosis, or a better assessment of the stenosis was possible with MRI, because of the avoidance of overshadowing of the affected bowel loop with MRI. A brilliant MR-tomographic imaging of the small bowel is possible under the condition, that the small bowel contrast is optimal. The ...
Magnetic resonance (MR) images of 18 cases of hilar cholangiocarcinoma were evaluated to compare the effectiveness of Gd-DTPA with that of high dose contrast enhancement computed tomography (HCE-CT) in detecting the primary tumor. The primary tumor was demonstrated as having slightly low intensity compared with liver parenchyma and high intensity compared with the delated bile duct on T1-weighted images. In contrast, MRI using Gd-DTPA, which was carried out in five cases, revealed intense enhancement of the tumor. As the differentiation between cholangiocarcinoma and dilated bile duct was difficult, it was concluded that the use of Gd-DTPA improves the efficacy of MRI in diagnosing cholangiocarcinoma. Gd-DTPA was also effective in differentiating the growth pattern of the tumor: the infiltrating type was demonstrated as thickening of the wall of the bile duct, the polypoid type as a soft tissue mass in the bile duct. ...
The effects of the contrast of the pump field interference pattern, that is, the effectiveness of the dynamic amplitude-phase grid, and various optical arrangements on the lasing efficiency and tuning range of a dynamic distributed-feedback dye laser are investigated. It is shown that the proper choice of prism apex angle, prism material and dye solvent in a laser in the range 400-1000 microns pumped by two beams of different intensity directed through the congruent sides of an isosceles prism in contact with the active medium solution on its third side can lead to optical losses of less than 2% from the boundaries of the prism. Measurements of polymethine dye laser efficiency and tuning range as a function of the relative intensity of the two ruby-laser pump beams reveals that as the contrast of the pump beam interference pattern decreases, the tuning range remains practically constant and the efficiency increases in the nonlinear (saturation) ...
Monoclonal antibodies (MAbs) 19-9 and 73-3 specific for human colon adenocarcinoma were labelled with a high number of gadolinium atoms. Twenty five DTPA were chelated per MAb, with only slight loss of immunoreactivity. The NMR contrast agent Gd-25 DTPA-MAb 19-9 or 73-3 ((Gd) 17 mumole/kg, (MAb) 60 microM) was injected into nude mice bearing human colon adenocarcinoma (SW948). Tumors were removed 24 hr after injection and T1 was measured in vitro. T1 relaxation time varied according to MAb specificity against tumour targets; T1 decreased 20% for MAb 19-9 and MAb 73-3 with SW948 tumor. Imaging was performed with this model. Very good contrast was obtained 24 hr after Gd-25 DTPA-MAb injection.
Molecular imaging represents a modern research area that allows the in vivo study of molecular biological process kinetics using appropriate probes and visualization methods. This methodology may be defined- apart from the contrast media injection - as non-abrasive. In order to reach an in vivo molecular process imaging as accurate as possible the effects of the used probes on the biological should not be too large. The contrast media as important part of the molecular imaging can significantly contribute to the understanding of molecular processes and to the development of tailored diagnostics and therapy. Since more than 15 years PTB is developing optic imaging systems that may be used for fluorescence based visualization of tissue phantoms, small animal models and the localization of tumors and their predecessors, and for the early recognition of inflammatory processes in clinical trials. Cellular changes occur during many diseases, thus the ...
Selective alveolo-bronchography (SAB) has been routinely used to evaluate anatomical changes in the bronchiole and its distal air spaces. A narrowing of the bronchiole and abnormal pooling of contrast medium in the destroyed air space are the prime findings. Since the object of radiography is extremely thin, direct magnification radiography is mandatory to obtain radiologic details. However, the problem with this technique is that radiographic quality varies depending upon the size of the patient and the concentration of contrast medium to be introduced in the lung. This study had two goals. One was to improve the image quality of SAB by Fuji Computed Radiography (FCR). FCR provides radiographs with a good contrast and stable density throughout a wide range of exposure factors which occur in the use of SAB. The other goal was to separately evaluate morphological abnormalities in the outer and inner zones of the lung using ...
A computer-aided detection (CAD) system was evaluated for its ability to detect microcalcifications and masses on images obtained with a digital phase-contrast mammography (PCM) system, a system characterised by the sharp images provided by phase contrast and by the high resolution of 25-{mu}m-pixel mammograms. Fifty abnormal and 50 normal mammograms were collected from about 3,500 mammograms and printed on film for reading on a light box. Seven qualified radiologists participated in an observer study based on receiver operating characteristic (ROC) analysis. The average of the areas under ROC curve (AUC) values for the ROC analysis with and without CAD were 0.927 and 0.897 respectively (P = 0.015). The AUC values improved from 0.840 to 0.888 for microcalcifications (P = 0.034) and from 0.947 to 0.962 for masses (P = 0.025) respectively. The application of CAD to the PCM system is a promising approach for the detection of breast cancer in its ...
CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the ...
A protocol adapter ideally suited to enable enterprises to gradually transition from SOAP Web Services to RESTful HTTP Web Services without impacting existing clients is presented in this paper. The inherent advantage of such a transition is the visibility of RESTful HTTP messages to Web intermediaries such as caches. In contrast, SOAP messages are opaque, which disables Web intermediaries. While both approaches can use HyperText Transfer Protocol (HTTP) for message transfer, the paradigms contrast sharply. SOAP uses an interface specific approach whereas RESTful HTTP uses a Uniform Interface approach. SOAP marks up its payload with eXtensible Markup Language (XML) whereas in certain situations RESTful HTTP requires no XML. We present the disadvantages of the SOAP approach and outline how ...
MRI findings in 13 patients with monolateral parotid tumor were compared with US, sialographic and CT findings. MRI did not allow an accurate diagnosis in 2 patients with diffuse chronic parotitis. MRI was superior to CT in 1 case in defining the intraglandular site of the lesion, and in 2 patients in showing the extraglandular involvement. MRI proved to be superior to CT thanks to its contrast resolution and to multiplanar imaging. MRI high contrast resolution made it possible to demonstrate neoplastic lesions of 4 mm in diameter. The lesion has low signal intensity on T1-weighted images and high signal intensity on T2-weighted. Parotid tumors cannot be characterized by signal intensity alone: only morphology allows to discriminate between benign and malignant lesions. To conclude, US is a screening method, while MRI is helpful in detecting multifocal lesions and in evaluating the tumor extent.
Abstract A large remaining source of uncertainty in global model predictions of future climate is how ecosystem carbon (C) cycle feedbacks to climate change. We conducted a field manipulative experiment of warming and nitrogen (N) addition in a temperate steppe in northern China during two contrasting hydrological growing seasons in 2006 [wet with total precipitation 11.2% above the long-term mean (348 mm)] and 2007 (dry with total precipitation 46.7% below the long-term mean). Irrespective of strong intra- and interannual variations in ecosystem C fluxes, responses of ecosystem C fluxes to warming and N addition did not change between the two growing seasons, suggesting independence of warming and N responses of net ecosystem C exchange (NEE) upon hydrological variations in the temperate ...
We present a novel fabrication route yielding Raney-platinum film electrodes intended as glucose oxidation anodes for potentially implantable fuel cells. Fabrication roots on thermal alloying of an extractable metal with bulk platinum at 200^oC for 48h. In contrast to earlier works using carcinogenic nickel, we employ zinc as potentially biocompatible alloying partner. Microstructure analysis indicates that after removal of extractable zinc the porous Raney-platinum film (roughness factor ~2700) consists predominantly of the Pt3Zn phase. Release of zinc during electrode operation can be expected to have no significant effect on physiological normal levels in blood and serum, which promises good biocompatibility. In contrast to previous anodes based on hydrogel-bound catalyst particles the ...
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...
Between 1983 and 1986, 35 of 90 patients with acquired immunodeficiency syndrome (AIDS) had double-contrast esophagograms to rule out opportunistic esophagitis. The radiographs were reviewed without knowledge of the clinical or endoscopic findings. Candida esophagitis was diagnosed radiographically in 17 patients who had varying degrees of plaque formation and viral esophagitis in three who had discrete ulcers without plaques. All three patients with viral esophagitis (herpes in 2 and cytomegalo virus in one) and 15 of 17 with Candida esophagitis had endoscopic and/or clinical corroboration of the radiographic diagnosis. Thus, the authors' experience suggests that fungal and viral esophagitis can often be differentiated on double-contrast esophagography, so that appropriate antifungal or antiviral therapy can be instituted without need for endoscopic intervention.
In an extended case report, we discuss four cases with masses in the lacrimal fossa representing the most important entities in this region (lymphoma, pleomorphadenoma, inflammatory pseudotumor, and malignant epithelial tumor). The different indications for CT and MRI are explained. For the differential diagnosis of lacrimal gland lesions, the following imaging parameters are important: The shape of the lacrimal gland, the inner structure, the degree of contrast enhancement, and the surrounding bony structures. In the evaluation of the expansion of lacrimal gland lesions, CT in thin slices with multiplanar reconstructions is equal to MRI. However, the contrast-enhancement of lacrimal glands is better evaluated with MRI than with CT. The bony structures are better visualized on CT than on MRI. (orig.).
Fetal MRI examines non-invasively the unborn fetus. Ultrafast MRI sequences effectively suppress fetal motion. Multiple case reports and studies have shown that fetal MRI is particularly helpful in the evaluation of the central nervous system. The high contrast-to-noise ratio, the high spatial resolution, the multiplanar capabilities, the large field of view and the simultaneous visualisation of fetal and maternal structures have proven to be advantageous. Fetal MRI is particularly helpful in the evaluation of the normal and pathological development of the brain. Despite the fact that no side effects have been reported or are to be expected, the use of MRI during pregnancy is still limited to the second and third trimester of pregnancy. Magnetic resonance imaging contrast media are not to be used as it passes the placenta. Ultrasound remains the primary screening modality for fetal pathology; fetal MRI can serve as an adjunct or second-line ...
An iterative phase retrieval algorithm was previously investigated for in-line x-ray phase imaging. Through detailed theoretical analysis and computer simulations, we now discuss the limitations, robustness, and efficiency of the algorithm. The iterative algorithm was proved robust against imaging noise but sensitive to the variations of several system parameters. It is also efficient in terms of calculation time. It was shown that the algorithm can be applied to phase retrieval based on one phase-contrast image and one attenuation image, or two phase-contrast images; in both cases, the two images can be obtained either by one detector in two exposures, or by two detectors in only one exposure as in the dual-detector scheme.
Purpose. We report a case of Ewing's sarcoma in the right distal femur in a 6-year-old male to demonstrate how dynamic contrast-enhanced magnetic resonance imaging (DEMRI) findings predicted histopathology. Materials and methods. DEMRI was performed at presentation and during and after completion of chemotherapy and radiation therapy. Histopathologic studies were done at presentation, at 77 weeks (20 weeks after a pathological fracture), and from the en bloc resection at 104 weeks. Results. DEMRI predicted the early tumor response, absence of tumor recurrence, presence of necrosis and lack of fracture healing, confirmed by histopathology. Conclusion. DEMRI is a clinically useful tool in managing Ewing's sarcoma. (orig.)
Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction technique, and so on. For the real-time application a contouring operation and an averaging approach can also be utilized effectively.
Real-time neutron radiography (NTV) has been used for practical applications at the Kyoto University Reactor (KUR). At present, however, the direct image from the TV system is still poor in resolution and low in contrast. In this paper several image improvements are demonstrated, such as a frame summing technique, which are effective in increasing image quality in neutron radiography. Image integration before the A/D converter has a beneficial effect on image quality and the high quality image reveals details invisible in direct images, such as: small holes by a reversed image, defects in a neutron converter screen through a high quality image, a moving object in a contoured image, a slight difference between two low-contrast images by a subtraction technique, and so on. For the real-time application a contouring operation and an averaging approach can also be utilized effectively. (orig.).
Twenty-three patients with intracranial meningiomas were examined by means of magnetic resonance tomography (MRT). In 13 patients the paramagnetic contrast medium gadolinium DTPA was used. Meningiomas show only slight changes in signal intensity compared with brain in the spin-echo mode, the greatest contrast being found on photon density images (TR 1600 ms, TE 35 ms). In T1 images more than 50% of the patients showed a low signal margin between tumour and brain. Hyperostosis of the calvarium is easily recognised, but MRT is unreliable for showing tumour calcification. After intravenous injection of gadolinium DTPA, there was marked homogeneous uptake in the meningiomas. These signs are useful for the diagnosis of a meningioma by MRT. (orig.).
Forty-seven subtraction images of FCR were compared with subtraction images of conventional angiography of the head. Quality of the FCR images were equal or superior to that of conventional angiography. Antero-posterior projection of external carotid arteriography by FCR was most useful because of its wide dynamic range. As contrast resolution of FCR is superior to that of conventional angiography, only half diluted contrast media was needed. As for spacial resolution, FCR is slightly inferior to conventional angiography. However, most vessels which are clinically important were adequately demonstrated. A weak point of FCR which should be improved is relatively long time to process the images after radiation exposure. (author).
Kelvin-Helmholtz instability of short gravity waves is examined in order to explain the recent findings of the decrease in momentum transfer from hurricane winds to sea waves. A three-fluid configuration of a foam layer between the atmosphere and the ocean is suggested to provide signifficant stabilization of the system and shifting the marginal critical wavelength to the shortwave part of the spectrum. It is conjectured that such stabilization leads to the observed drag reduction. The high contrasts in three fluid densities provide a universal mechanism for stabilizing surface perturbations.
In contrast to plants based on formed coal where, for the purposes of calculating sorbent volume, only one activated charcoal design can be used in a filter layer, powder sorbent technology enables two variations to be used. This can be either a mixture of a number of different activated charcoal forms in one and the same filter layer, or the combination of a number of filter layers on top of each other, each containing a different activated charcoal form, in one and the same construction unit.
Ultrasound tomography is an attractive imaging method for the detection of breast cancer. The complex anatomy of the breast with its different spatial scales and material property contrasts make accurate reconstructions very challenging. This paper proposes a hybrid approach whereby Travel-of-Flight and Diffraction Tomography are combined together to achieve high-resolution and high-accuracy sound-speed reconstructions. The method is validated with several numerical phantoms.
The pressure of a 6:12 fluid is obtained from the Percus-Yevick theory at the temperature kT/? = 1.35. The energy equation results are in excellent agreement with machine calculation results in contrast to the pressure and compressibility equation results. Present address: Diffusion Research Unit, The Australian National University, Canberra, ACT, Australia.
Gas and stars in spiral galaxies are modelled with the DUAL code, using hydrodynamic and N-body techniques. The simulations reveal morphological differences mirroring the dual morphologies seen in B and K' band observations of many spiral galaxies. In particular, the gaseous images are more flocculent with lower pitch angles than the stellar images, and the stellar arm-interarm contrast correlates with the degree of morphological decoupling.
The wave equation of a spinless tachyon is studied in Schwarzschild space-time. In contrast to earlier approaches to the problem, it is shown that tachyonic static solutions satisfy a simple second-order linear differential equation regardless of the mass of the black hole and the mass parameter of the tachyon. Physical implication of the present approach is discussed. Using Langer modification of the WKB (Wentzel-Kramers-Brillouin) boundary condition an expression similar to the Bohr-Sommerfeld quantization condition is derived.
Here, we provide the first study of prolactin (PRL) and prolactin receptor (PRLR) expression during the nonseasonal murine hair cycle, which is, in contrast to sheep, comparable with the human scalp...Full Text Available
After slow progress in the efforts to develop phase plates for electron microscopes, functional phase plate using thin carbon film has been reported recently. It permits collecting high-contrast images...Full Text Available
To evaluate the usefulness of three-dimensional (3D) rotational angiography, cervical carotid or cerebral angiography was done without catheterizing the branches of the thoracic aorta. A 5-Fr pig-tail type catheter was passed into the ascending aorta via the radial artery or the femoral artery. Optimal carotid angiogram views were obtained using approximately 45 ml of contrast medium at a flow rate of 15 ml/sec. Optimal cerebral angiogram views were obtained using approximately 70 ml of contrast medium at a flow rate of 20 ml/sec. The contrast medium concentration was 300 to 350 mgI/ml. A satisfactory view could be obtained in 5 of 8 (63%) cases on cervical carotid 3D angiography and in 8 of 14 (57%) cases on cerebral 3D angiography. In all cases, no complications were noted. This method offers the advantages of requiring a relatively short procedure time and a decrease in radiation exposure. Further studies are needed to ...
A real-time neutron radiography facility was constructed including the capability of neutron tomography. The neutron beam was measured for total neutron flux ((1.0 +/- 0.2) x 10/sup 11/ m/(m/sup 2/-sec)), gold cadmium ratio (52 +/- 3) and effective neutron temperature (83/sup 0/C +/- 8/sup 0/C). The angular divergence or nonparallelism of the neutron beam was measured to be 2.3/sup 0/ +/- 0.1/sup 0/ thereby providing a means of quantifying the collimator effectiveness. The resolution capabilities of both static film and real-time neutron radiographs were quantified using a Fourier transform algorithm to calculate the modulation transfer function of both types of radiographs. The contrast sensitivity of both types of radiographs. The contrast sensitivity of both types of radiographs was measured as 3.1% for film and 4.0% for real-time radiographs. Two tomography algorithms, the simultaneous iterative reconstruction technique (SIRT) and the ...
A real-time neutron radiography facility was constructed including the capability of neutron tomography. The neutron beam was measured for total neutron flux ((1.0 +/- 0.2) x 10"1"1 m/(m"2-sec)), gold cadmium ratio (52 +/- 3) and effective neutron temperature (83"0C +/- 8"0C). The angular divergence or nonparallelism of the neutron beam was measured to be 2.3"0 +/- 0.1"0 thereby providing a means of quantifying the collimator effectiveness. The resolution capabilities of both static film and real-time neutron radiographs were quantified using a Fourier transform algorithm to calculate the modulation transfer function of both types of radiographs. The contrast sensitivity of both types of radiographs. The contrast sensitivity of both types of radiographs was measured as 3.1% for film and 4.0% for real-time radiographs. Two tomography algorithms, the simultaneous iterative reconstruction technique (SIRT) and the convolution method, were ...
The image processing system for the dynamic neutron radiography has been developed. It is based on the hardware subset, composed by the method of the pipe-line and use of algorithm of local statistics. The processing speed per one pixel is shorter than 100 n sec and video-rate processing can be executed on it. Some image processes for improving the quality of the real-time neutron image, noise reduction and contrast stretching would be attempted by the use of this system. (author).
Abstract An analytical model is developed to predict transient discharge flow into a tunnel drilled at various speeds through a heterogeneous formation. This model relies on simplifying assumptions commonly enforced in hydrogeologic engineering, and combines the convolution and superposition principles to account for composite sections with arbitrary parametric contrasts. An application to the data monitored during the exploratory drilling of an Alpine tunnel confirms the validity of the approach.
A pulsed field gradient spin echo sequence has been incorporated in a nuclear magnetic resonance (NMR) imaging experiment to provide an image contrast dependent on local molecular self-diffusion. The...Full Text Available
Endogenous fluorescence provides morphological, spectral, and lifetime contrast that can indicate disease states in tissues. Previous studies have demonstrated that two-photon autofluorescence microscopy (2PAM) can be used for noninvasive, three-dimensional imaging of epithelial tissues down to approximately 150 ?m beneath the skin surface. We report ex-vivo 2PAM images of epithelial tissue from a human tongue biopsy down to 370 ?m below the surface. At greater than 320 ?m deep, the fluorescence generated outside the focal volume degrades the image contrast to below one. We demonstrate that these imaging depths can be reached with 160 mW of laser power (2-nJ per pulse) from a conventional 80-MHz repetition rate ultrafast laser oscillator. To better understand the maximum imaging depths that we can achieve in epithelial tissues, we studied image contrast as a function of depth in tissue phantoms with a range of relevant ...
A new magnetic electron microscope, UEMB-100, was designed with an increased electron-optical parameter. The electron-optical system consists of an electron canon (the high voltage is supplied by armored lead) and condensed, objective, intermediate, and projection lenses. In contrast to other native apparatuses, the microscope has a high resolving property (up to 20A) snnd great universality. (tr-auth)
In Spiral CT, the pitch is the ratio of the distance to tabletop travels per 360 degrees rotation to nominal slice width, expressed in mm. Performing Spiral CT examination with pitch 2 allows to reduce examination time, exposure and contrast dose, and X-ray tube overload. The authors investigated the yield of pitch 2 in lung parenchyma studies, particular relative to diagnostic image quality.
Potential strategic missions for laser weapons, particularly those involving space-based lasers, are discussed. The functions of space-based lasers and the history of their conceptual development are summarized, and the problems of implementing such systems, including the building of a suitable laser and power source, and resolving the problem of optics, are discussed. Ongoing development programs are described, and the contrasting views of the necessity and usefulness of strategic laser systems are set forth.
Distribution of Lipiodol within hepatic tumor was evaluated using serial computed tomography. Imagistic Lipiodol transition into the tumor via hepatic artery was slower than that of water soluble contrast medium, spreading to central part first and turn to peripheral part of the tumor. This method was thought to be useful to clarify Lipiodol distribution in hepatic tumor and to decide the method or necessity of additional trans-arterial therapy. (author).
Iodixanol is a new nonionic dimer, isotonic with blood at all clinically relevant concentrations. Iodixanol (270 mg I/ml) was compared in a double-blind, randomized, parallel-group, phase-III study to the monomeric nonionic iohexol (300 mg I/ml) for evaluation of safety, tolerability and radiographic efficacy during cerebral CT. One hundred adult patients scheduled to undergo contrast-enhanced cerebral CT were randomly allocated to receive either iodixanol or iohexol. All completed the trial. Safety was evaluated by recording discomfort and other adverse events, tolerance by assessing intensity and incidence of discomfort. Radiographic efficacy was assessed from the diagnostic information and the radiographic density. No serious adverse events occurred. One patient (2 %) in the iodixanol group and one patient (2 %) in the iohexol group experienced a transient reddening at the neck and lower neck-line, respectively. Both contrast agents were ...
In this work, energy-based features for gear fault diagnosis and prediction are proposed. The instantaneous energy density is shown to obtain high values when defected teeth are engaged. Three methods are compared in terms of sensitivity, reliability and computation effectiveness. The Wigner Ville distribution is contrasted to the wavelet transform and the newly proposed empirical mode decomposition scheme. It is shown that all three methods are capable of a reliable prediction. An empirical law, which relates the energy content to the crack magnitude is established.
DescriptionFossil fuels have a detrimental effect on the environment. They lead to the increase in atmospheric carbon dioxide which has been documented over the last 150 years. In contrast, some sources of renewable energy are near carbon neutral. Renewable energy produced from biomass constitutes such a type of energy and so has many potential advantages. The Energy White Paper (DTI et al., 2003) identifies bioenergy as an important means of meeting the Government's energy and environment objectives, in [continued...
... (restricted)] 101-127 On the transmission of exchange rate fluctuations to the macroeconomy: Contrasting evidence for developing and developed countries by Magda Kandil [Downloadable! (restricted)] 2005, Volume 14, Issue 4 377-405 Predicting the poverty impacts of trade reform by Thomas Hertel & Jeffrey Reimer [Downloadable! (restricted)] 407-435 Sustaining imperfectly credible trade liberalization: Do the rate of tariff reduction ...
The Focused-Ion-Beam (FIB) is a powerful tool for fast, precision cross-sectioning and inspection of submicron defects in multilayered integrated circuit devices. However, the low contrast between the layers in FIB cross-sections can make the feature of interest difficult to observe, which has become a limitation for FIB cross-sectioning. A technique using plasma etch to decorate the FIB cross-sections has proven to be a simple solution to overcome this limitation.
In this study we extend the analysis of magnetopause crossings observed with Magnetospheric Plasma Analyzer measurements to examine a much larger statistical data set. This study examines 39 maiznetosheath/LLBL intervals from 79 spacecraft-months of observations: these observations were taken from a survey of data from the start of each spacecraft mission and extending through March 1993. In contrast to the previous findings, we find no evidence for a significant dawn/dusk asymmetry in geosynchronous magnetopause crossings.
Threshold pump intensity values leading to irreversible damage to colored laser elements based on elastic polymers were measured. The damage to colored elastomers is connected with absorbing microinclusions but is independent of molecular absorption. It is shown that damage to the elastomers has a pronounced threshold character in contrast to the microdamage accumulation effect in glassy polymers. The damage threshold for elastomers is 1.5 times higher, which is connected with the absence of microstresses (characteristics for organic glasses) in the specimens. 13 references.
We propose and construct a new type of extended superconformal algebra (ESA) based on the super Toda field theory. Both in the N = 1 ESA and in the N = 2 ESA, an arbitrary value of the central charge is allowed in contrast with the previously known super W-algebra. The generators of ESA are interpreted as the constants of motion in the super Toda field theory. (orig.).
Intravenous digital subtraction angiography using Fuji computed radiography system (FCR-DSA) was used to evaluate 57 preoperative patients with clinical manifestations of peripheral vascular disease of lower extremity. With its high contrast resolution and good special resolution, image of FCR-DSA could offer optimal information of vascular abnormality in lower extremity distal to midfoot for the diagnosis and the choice of management.
Intravenous digital subtraction angiography using Fuji computed radiography system (FCR-DSA) was used to evaluate 57 preoperative patients with clinical manifestations of peripheral vascular disease of lower extremity. With its high contrast resolution and good special resolution, image of FCR-DSA could offer optimal information of vascular abnormality in lower extremity distal to midfoot for the diagnosis and the choice of management. (orig.).
The endogenous reverse transcriptase reaction of equine infectious anemia virus (EIAV) has been studied, and conditions allowing synthesis of full-length minus-strand DNA have been determined. In contrast...Full Text Available
Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% ...
DescriptionThe importance of inorganic nitrate for the nutrition and growth of marine and freshwater autotrophic phytoplankton has long been recognised, in particularly because of the 'blooms' formed in nitrate and phosphate polluted water and their possible roles as carbon dioxide sinks. By contrast, the utilisation of nitrate by heterotrophic bacteria has historically received less attention. Up until now, the primary role of heterotrophic bacteria has classically been considered to be the decomposition [continued...
This paper discusses the concept of controllable subspace for open quantum dynamical systems. It is constructively demonstrated that combining structural features of decoherence-free subspaces with the ability to perform open-loop coherent control on open quantum systems will allow decoherence-free subspaces to be controllable. This is in contrast to the observation that open quantum dynamical systems are not open-loop controllable. To a certain extent, this paper gives an alternative control theoretical interpretation on why decoherence-free subspaces can be useful for quantum computation.
Computing Networks (CNs) are defined. These are used to generalize neural and swarm architectures, namely artificial neural networks, ant colony optimization, and particle swarm optimization. The description of these architectures as CNs allows their comparison, distinguishing which properties enable them to perform complex computations and exhibit complex cognitive abilities. In this context, the most relevant characteristics of CNs are the existence multiple dynamical and functional scales.
Forty-four patients with small cell carcinoma of the bronchus underwent CT and MR studies of the brain to detect cerebral metastases. All patients were studied with contrast-enhanced CT scans, short (T1-weighted) and long (T2-weighted), spin-echo (SE) and FLASH 90 grades sequences were also obtained. A quantitative comparison of the results was carried out to assess the sensitivity of the different techniques in the detection of brain metastases according to lesion diameter. Metastases were identified in 19/44 patients (43%). All techniques detected the lesions >2 cm; of the metastases <2 cm, 63/124 (51%) were detected only by GdDTPA SE-T1 and FLASH sequences and 11 more (9%) only by Gd-DTPA SE-T1 scans. All the lesions identified oh enhanced CT scans or on T2-weighted images were easily detected by Gd-DTPA scans. CT sensitivity was higher than that of pre-contrast SE-T1 and FLASH studies and only slightly lower than that of T2-weighted ...
A reciprocal relationship informing both research and practice is one of the primary goals in the emerging field of Mind, Brain, and Education (MBE), yet the field has little documentation and analysis of such collaborations. In this article, we present case studies of three research-practice partnerships taking place between scientists and educators. By comparing and contrasting these three partnerships we expect to illuminate common characteristics, challenges, and benefits that come with doing MBE work.
Fatty acid biosynthesis is crucial for all living cells. In contrast to higher organisms, bacteria use a type II fatty acid synthase (FAS II) composed of a series of individual proteins, making...Full Text Available
Venture capital has guaranteed the successful launch of biotechnology in the US since 1977. Established companies are then licensed to produce and distribute the latest inventions. By contrast in Japan established industrial companies are the leaders in biotechnology research, development and commercialization, building on existing technology and past experience and retraining staff. In the US electronics industry the acute shortage of electronic engineers combined with the high cost of capital and instability within venture capital companies to restrict the high level of innovation required looks likely to happen again in biotechnology.
An imaging detector for {gamma}-rays ({approx equal}1 MeV) based on minicell MWPCs with converters and a position resolution of {Delta}x=0.5 mm has been developed and tested. Very high rate capability (>10{sup 8}/cm{sup 2} s) and a special readout for suppression of scattered radiation are implemented allowing to enhance the measured contrast. The relevant physical processes are discussed and first pictures are presented. (orig.).
The Wannier threshold law for three-particle fragmentation is reviewed. By integrating the Schroedinger equation along a path where the reaction coordinate R is complex, anharmonic corrections to the simple power law are obtained. These corrections are found to be non-analytic in the energy E, in contrast to the expected analytic dependence upon E.
An integrated voltage regulator and power system stabilizer based on one step ahead prediction is presented. The fixed parameter predictive control scheme is shown capable of providing consistently good voltage response and contribution to system damping over a wide range of operating conditions and system configuration. This is in contrast to the case with conventional automatic voltage regulator and power system stabilizer where performance varies widely with the operating situation and can even cause system instability. (author)
Amyloid plaques are a characteristic feature in Alzheimer’s disease (AD). A novel non-toxic contrast agent is presented, Gd-DTPA-K6Aβ1–30, which is homologous to Aβ,...Full Text Available
In this talk I briefly summarize different models for #sigma#_2_#gamma#"t"o"t (e"+e"-#->##gamma##gamma##->#hadrons) and contrast model predictions with the data. I will then discuss the capability of the future e"+e"- and #gamma##gamma# colliders to distinguish between various models and end with an outlook for future work.
Silicon carbide (SiC) based electronic devices are of great importance for applications under the condition of high temperature, high power and high radiation. Schottky diodes of Palladium/SiC are good candidates for hydrogen and hydrocarbon gas sensors at elevated temperature. The detection sensibility of the diodes has been found heavily temperature dependent. In this work, the electrical and chemical properties of Pd/SiC Schottky contacts were studied by XPS and AES at different annealing temperatures. Schottky diodes were made by depositing ultra-thin palladium films onto a silicon carbide substrate. No significant change in the Schottky barrier height of the Pd/SiC contact was found in the temperature range of 300-673K. Palladium diffusion into SiC and the formation of palladium silicides were observed at room temperature and became significant at 300^oC and higher temperature. The mechanism of diffusion and reaction at the Pd/SiC interface will be discussed. ...
Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 by the irradiation. From these results we can find that irradiation with the X-ray ...
Recently the increase of steam temperature and pressure of power plant is required to enhance the thermal efficiency and reduce the CO{sub 2} emission. For the application to advanced USC (Ultra Super Critical) boiler with steam temperature around 700 C, the application of Ni-based alloy such as Alloy617 will be necessary. A new Ni-based alloy USC141 (20Cr-10Mo-2Ti-Al-bal.Ni) with excellent creep rupture strength and low thermal expansion has been developed by Hitachi Ltd. and Hitachi Metals Ltd. as the candidate material for 700 C USC turbine components. In present work, to investigate the possibility for boiler tube application of USC141, its weldability and high temperature strength properties were experimentally examined. The tested material as solution-treated condition shows higher creep rupture strength than that of Alloy617. GTAW (Gas Tungsten Arc Welding) trials of tubular specimen using NIMONIC263 filler wire were conducted successfully and the creep ...
The WIDeField telescope for Gamma-ray burst Early Timing (WIDGET) is used for a fully automated, ultra-wide-field survey aimed at detecting the prompt optical emission associated with Gamma-ray Bursts (GRBs). WIDGET surveys the HETE-2 and Swift/BAT pointing directions covering a total field of view of 62 degree x 62 degree every 10 secounds using an unfiltered system. This monitoring survey allows exploration of the optical emission before the gamma-ray trigger. The unfiltered magnitude is well converted to the SDSS r' system at a 0.1 mag level. Since 2004, WIDGET has made a total of ten simultaneous and one pre-trigger GRB observations. The efficiency of synchronized observation with HETE-2 is four times better than that of Swift. There has been no bright optical emission similar to that from GRB 080319B. The statistical analysis implies that GRB080319B is a rare event. This paper summarizes the design and operation of the WIDGET system and the simultaneous GRB ...
Critical experiments have been analyzed to verify a nuclear analysis system for fast reactors used in Japan Nuclear Cycle Development Institute (JNC). The experiments were performed in a collaboration work between JNC and the Institute of Physics and Power Engineering of Russia to dispose Russian surplus weapons plutonium, focusing on the effect of the introduction of uranium-plutonium mixed-dioxide (MOX) fuel and stainless steel reflector into the current BN-600 core that is comprised of UO_2 fuel and blanket. The analysis results agreed well with measured values on most of the nuclear characteristics. The accuracies are comparable to those obtained for the conventional MOX fueled fast reactors. It suggests that the JNC analysis system can analyze accurately nuclear characteristics in uranium fueled cores as well. A significant improvement was achieved on the sodium void reactivity by employing an ultra fine group cell calculation system. A change in adjoint ...
It is widely accepted that the prompt transient signal in the 10 keV - 10 GeV band from gamma-ray bursts (GRBs) arises from multiple shocks internal to the ultra-relativistic expansion. The detailed understanding of the dissipation and accompanying acceleration at these shocks is a currently topical subject. This paper explores the relationship between GRB prompt emission spectra and the electron (or ion) acceleration properties at the relativistic shocks that pertain to GRB models. The focus is on the array of possible high-energy power-law indices in accelerated populations, highlighting how spectra above 1 MeV can probe the field obliquity in GRB internal shocks, and the character of hydromagnetic turbulence in their environs. It is emphasized that diffusive shock acceleration theory generates no canonical spectrum at relativistic MHD discontinuities. This diversity is commensurate with the significant range of spectral indices discerned in prompt burst ...
'Full text:' The use of fuel cell technology in military applications will depend on safe, high energy density systems being developed. An important part of using this technology is also the development of alternative hydrogen producing fuels with high energy densities and are easy to transport. Fuel cells are now a very large R and D effort for several military applications around the world. The major reason is because of the high power demands needed requires electrical energy sources that far exceed the capabilities of batteries currently being fielded for portable applications. Fuel cells are regarded as highly efficient, tactical energy converters that can be adapted for wide range of power requirements. They are potentially the lowest weight power source when coupled with batteries or capacitors to form hybrid systems. Generally electrical power is needed to support a number of applications from ultra-high power for electrical pulses (radios, sensors) to ...
A 2-stage cold (non-tritium) PMR system was tested with the ITER mix in61 days of continuous operation. No decrease in performance was observed over the duration of the test. Decontamination factor (DF) was found to increase with decreasing inlet rate. Decontamination factors in excess of 1.4 {times} 10{sup 5} were obtained, but the exact value of the highest DF could not be determined because of analysis limitations. Results of the 61-day test were used to design a 2-stage PMR system for use in tritium testing. The PMR system was scaled up by a factor of 6 and built into a glovebox in the Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory. This system is approximately 1/5th of the expected full ITER scale. The ITER mix was injected into the PMR system for 31 hours, during which 4.5 g of tritium were processed. The 1st stage had DF = 200 and the 2nd stage had DF = 2.9 {times} 10{sup 6}. The overall DF = 5.8 {times} 10{sup 8}, which is greater than ITER ...
A 2-stage cold (non-tritium) PMR system was tested with the ITER mix in 61 days of continuous operation. No decrease in performance was observed over the duration of the test. Decontamination factor (DF) was found to increase with decreasing inlet rate. Decontamination factors in excess of 1.4x10"5 were obtained, but the exact value of the highest DF could not be determined because of analysis limitations. Results of the 61-day test were used to design a 2-stage PMR system for use in tritium testing. The PMR system was scaled up by a factor of 6 and built into a glovebox in the Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory. This system is approximately 1/5"t"h of the expected full ITER scale. The ITER mix was injected into the PMR system for 31 hours, during which 4.5 g of tritium were processed. The 1"s"t stage had DF =200 and the 2"n"d stage had DF=2.9x10"6. The overall DF=5.8x10"8, which is greater than ITER requirements. 3 refs., 10 figs.
The B-Factory which is constructed by National Laboratory for High Energy Physics is the device for elucidating the breakdown of symmetry of matter and antimatter by studying the behavior of B mesons which are generated in large quantity when the electrons and the positrons which are accelerated to light velocity level are collided. In order to maintain electron beam-positron beam bunch circling the ring at light velocity stably, the instability of the coupled bunch must be overcome. For this purpose, the ultrahigh speed beam position digital feedback control system was developed. This system is composed of the high speed input-output substrate using GaAs LSI, the feedback computation substrate using complementary metal oxide semiconductor and the memory mounted on it, and the real time operation device. The development of both substrates and their functions are explained. The real time data collection and the change of computation parameters for specific bunch in the real time ...
In this paper, we show that boron transient enhanced diffusion can be reduced to different extents by varying the distribution of nitrogen atoms in the junction. This is attributed to the relative location of nitrogen atoms with respect to boron profile and end-of-range defect band, affecting the interactions between dopants and defects upon annealing. In addition, variations in boron dopant activation and deactivation are also observed. Similar to fluorine co-implantation, it is proposed that nitrogen atoms react with vacancy point defects to form nitrogen-vacancy clusters that will trap the interstitials emitted from end-of-range defects. However, we report that the interstitial sink efficiency of nitrogen atoms is not as good as the co-implanted carbon atoms, which is noticed from the dopant deactivation curves. In terms of extended defect evolution, the results clearly indicate that end-of-range defects can be stabilized by choosing the optimized co-implant condition of N. Finally, ...
Abstract in english Frontal weapon is the term used to designate the apparatus consisting of frontal gland and associated structures that participate in the chemical defense of termite soldiers. The ultra structure of the frontal gland and the scanning microscopy of the soldier head was investigated in the termite Amiitermes euamignathus Silvestri, 1901.Campaniform sensilla was not observed but there were 80 to100 sensory bristles around the frontal pore. The glandular epithelium shows only (more) class 1 cells according 10 the classification of NOIROT & QUENNEDEY (1974, 1991). The glandular cells are characterized by apical microvilli, a basal labyrinth and a large quantity of smooth endoplasmic reticulum which forms dense zones throughout the cytoplasm. The secretion is concentrated mainly in the basal pole of the cell and consists of large lipid droplets. The secretory epithelium is covered by a thick apical cuticle composed of a thin outer epicuticle, a ...
This paper describes an investigation of electrodeposited Zn-14% Ni and aluminium-based SermeTel 1140/962 coatings as possible replacements for cadmium. Slow strain rate tests were performed to measure the extent of direct hydrogen embrittlement of a high strength steel substrate as a result of the coating process and of hydrogen re-embrittlement caused by coating corrosion. The level of re-embrittlement was shown to depend on both the electrochemical potential of the coating and its barrier properties. Zn-14% Ni coatings caused the most re-embrittlement as they had the most active potential and contained through-thickness defects which left the steel exposed to hydrogen uptake. The microstructure of the high strength steel was also shown to be an important factor affecting the extent of embrittlement. AerMet 100 steel was more resistant than 300M steel and this was attributed to the presence of reverted austenite surrounding the martensite laths in AerMet 100, which trapped absorbed ...
We analyse how the structure of the inner curst is influenced by the pairing correlations. The inner-crust matter, formed by nuclear clusters immersed in a superfluid neutron gas and ultra-relativistic electrons, is treated in the Wigner-Seitz approximation. The properties of the Wigner-Seitz cells, i.e., their neutron to proton ratio and their radius at a given baryonic density, are obtained from the energy minimization at beta equilibrium. To obtain the binding energy of baryonic matter we perform Skyrme-HFB calculations with zero-range density-dependent pairing forces of various intensities. We find that the Wigner-Seitz cells have much smaller numbers of protons compared to previous calculations. For the dense cells the binding energy of the configurations with small proton numbers do not converge to a well-defined minimum value which precludes the determination of their structure. We show that for these cells there is a significant underestimation of the ...
Full text. Here we present a status report of the Schenberg antenna, which started commissioning runs in September 2006 under the full support of FAPESP. In its first commissioning runs we tested three preliminary parametric transducer systems, which did not achieve a high enough performance for placing the antenna sensitivity in the range of the calibrator capacitor. Instead of improving the calibrator, making it capable of introducing a larger input force, we decided to go to a radical upgrading operation: replacing the three transducers for a complete set of six transducers, with better sensitivity and arranged according to the truncated icosahedron configuration, plus two extra ones; starting to install the dilution refrigerator; installing wires, cables, and amplifiers for the complete set of transducer circuits; and a new suspension and vibration isolation system for the cabling and microstrip antennas. We also have been developing a new set of transducers, microwave oscillators, ...
In this study, the effects of 325nm wavelength ultraviolet light irradiation on pitting corrosion behavior of type 340 stainless steel in a neutral chloride solution are studied. Further, the change of passive film with the light irradiation is analyzed using x-ray photoelectron spectroscopy. The mains results obtained therefrom are stated below. Pitting potential can be shifted in noble direction by the ultraviolet light irradiation. The effect of ultraviolet light irradiation is ore prominent in the pitting corrosion process than that in the passive film formation. The result of the analysis in terms of the birth and death stochastic probability process shows that pitting corrosion rate is decreased remarkably by the ultraviolet light irradiation at the formation of passive film, while the repassivation is slightly expedited by the ultraviolet light irradiation. On the other hand, the repassivation rate is increased a little by the ultraviolet light irradiation during the pitting ...
Several observational studies suggest that solar wind dynamic pressure fluctuations can drive magnetospheric ultra-low frequency (ULF) waves on the dayside. To investigate this causal relationship, we present results from Lyon-Fedder-Mobarry (LFM) global, three-dimensional magnetohydrodynamic (MHD) simulations of the solar wind-magnetosphere interaction. These simulations are driven with synthetic solar wind input conditions, where idealized ULF dynamic pressure fluctuations are embedded in the upstream solar wind. In three of the simulations, a monochromatic, sinusoidal ULF oscillation is introduced into the solar wind dynamic pressure time series. In the fourth simulation, a continuum of ULF fluctuations over the 0-50 mHz frequency band is introduced into the solar wind dynamic pressure time series. In this numerical experiment, the idealized solar wind input conditions allow us to study only the effect of a fluctuating solar wind dynamic pressure, while holding ...
We report the direct molecular dynamics simulations for molecular ball bearings composed of fullerene molecules (C{sub 60} and C{sub 20}) and multi-walled carbon nanotubes. The comparison of friction levels indicates that fullerene ball bearings have extremely low friction (with minimal frictional forces of 5.283 x 10{sup -7} and 6.768 x 10{sup -7} nN/atom for C{sub 60} and C{sub 20} bearings) and energy dissipation (lowest dissipation per cycle of 0.013 and 0.016 meV/atom for C{sub 60} and C{sub 20} bearings). A single fullerene inside the ball bearings exhibits various motion statuses of mixed translation and rotation. The influences of the shaft's distortion on the long-ranged potential energy and normal force are discussed. The phonic dissipation mechanism leads to a non-monotonic function between the friction and the load rate for the molecular bearings.
The ultra-precise photometric space satellite MOST (Microvariability and Oscillations of STars) will provide the first opportunity to measure the albedos and scattered light curves from known short-period extrasolar planets. Due to the changing phases of an extrasolar planet as it orbits its parent star, the combined light of the planet-star system will vary on the order of tens of micromagnitudes. The amplitude and shape of the resulting light curve is sensitive to the planet's radius and orbital inclination, as well as the composition and size distribution of the scattering particles in the planet's atmosphere. To predict the capabilities of MOST and other planned space missions, we have constructed a series of models of such light curves, improving upon earlier work by incorporating more realistic details such as: limb darkening of the star, intrinsic granulation noise in the star itself, tidal distortion and back-heating, higher angular resolution of the light ...
Studies are made on coal in terms of its effective utilization, coal cleaning, fluidization and production of new fuel, and issues globally raised. Coal is abundant in reserves and high in supply stability and economic efficiency. However, it is much in CO2 emission per calorific value. To control as much CO2 emission as possible, effective utilization such as increasing of power generation efficiency has been proceeded with. In addition to ultra supercritical pressure and fluidized bed combustion, cited are coal gasification combined cycle power generation and high temperature type fuel cell. Coal has 5-20% ash and impurities like sulfur/nitrogen. Coal should be used clean by pollution abatement measures such as dust collecting, desulfurization and denitrification. Japan is at a world top level of these technologies. Coal is solid, and therefore, is more difficult to handle than liquid fuel. To use it easily, coal is liquefied into slurry such as COM and CWM, and ...
Superplasticity of polycrystalline metallic materials is a phenomenon which shows hundreds to thousands of percents of large plastic deformation without necking in a steady state of low stress, when the uni-axial tensile loading is done in some special thermo-mechanical conditions (some limited ranges of properly high temperature and low strain rate). The main mechanism of superplastic phenomenon is the grain boundary sliding, while the main mechanism of usual plastic deformation is the trans-granular sliding. In this research, the possibility of superplastic deformation in a magnesium alloy (AZ31Mg alloy) was experimentally investigated, because generally speaking, the magnesium alloy whose atomic structure is hexagonal does not have enough formability in a form of trans-granular sliding mechanism. In this paper, the detail of experimental results are shown and discussed. Moreover, the constitutive equations of Mg alloy are proposed on the basis of the experimental results. These ...
Research and development has been performed on photochromic materials expected to be used in ultra-high density recording, high resolution indication and photoswitches. With regard to molecular orientation in the ternary system mixed LB film, the result of structural analysis by XPM spectrum revealed that the acceptor constituent in the LB film is so structured that it is separated and laminated with two other constituents, and that the sensitizer constituent and the donor constituent are not recognized of being separated definitely. Regarding the electron movement reaction in the solid phase system, a photo-current measuring experiment was carried out on the laminated film which is vacuum-deposited with the ternary system comprising of the donor, sensitizer, and acceptor. It was concluded that the observed photo-current reflects the electron movement reaction in the solid phase as it is. For the photo-current in the LB film, increase in the photo-current was ...
Concerning the coal liquefaction research under way at the National Institute for Resources and Development, its purpose, contents, achievements, problems, future tasks, etc., are recapitulated. At the meeting, the coal liquefaction research is explained and discussed. Study tours are conducted to a liquefaction plant site, hydrolytic liquefaction facilities, and liquefaction facilities involving ultra-strong acid. Explanations are given on sub-themes of research in and after fiscal 1992 and the future prospects, and discussion is held on general matters. Various views and opinions are expressed by the committee members. Some ask what the chemical structure of coal is and what the model substance that represents coal is. Another insists that basic research on coal structure and reactivity be reconstructed. Those whose goal is to put the technology to practical use express their opinions that a clear position be given the liquefaction technology in the industrial ...
The 380 MW combined cycle gas turbine power station in Peterborough changed its water supply from town mains to high purity reverse osmosis permeate in October 2000. The high purity water is produced from secondary treated sewage effluent using advanced membrane technology. Alpheus Environmental and British Gas staff have recently completed a study of the power station's demineralization plant to identify the differences in operating costs associated with the change in feedwater. The results show that the ultrapure water produced after the change to a high purity feed is of improved quality and that the demineralization plant regeneration operating costs have been reduced by over 90%. The demineralization plant availability has increased from 78 to 98% enabling almost 20% more ultra pure water to be produced. The change in feedwater has also improved the local environment by significantly reducing the amount of waste chemicals discharged from the site. ...
The 10.3-h /sup 165/Er, decaying by electron capture to stable /sup 165/Ho, offers an excellent promise for use in diagnostic nuclear medicine, especially in conjuction with multiwire proportional-counter cameras. Using an ultra-high-resolution Si(Li) photon spectrometer, L and K x-ray photon yields in /sup 165/Er decay have been measured. The ratio P/sub L//P/sub K/ of electron-capture probabilities in L and K shells is determined to be 0.196 +- 0.030, in good agreement with theory. Estimates of Auger electron yields and yields of very-low-energy electrons from Coster--Kronig transitions are presented. Levels of /sup 169/Er and /sup 171/Er radioactive impurities in the reactor-produced /sup 165/Er sample are experimentally determined. Whole-body dose estimates for /sup 165/Er are given. These compare favorably with /sup 99/Tc dose.
The 10.3-h "1"6"5Er, decaying by electron capture to stable "1"6"5Ho, offers an excellent promise for use in diagnostic nuclear medicine, especially in conjuction with multiwire proportional-counter cameras. Using an ultra-high-resolution Si(Li) photon spectrometer, L and K x-ray photon yields in "1"6"5Er decay have been measured. The ratio P/sub L//P/sub K/ of electron-capture probabilities in L and K shells is determined to be 0.196 +- 0.030, in good agreement with theory. Estimates of Auger electron yields and yields of very-low-energy electrons from Coster--Kronig transitions are presented. Levels of "1"6"9Er and "1"7"1Er radioactive impurities in the reactor-produced "1"6"5Er sample are experimentally determined. Whole-body dose estimates for "1"6"5Er are given. These compare favorably with "9"9Tc dose.
This paper discussed the potential of biofuels with particular reference to the situation in Germany and Europe. Emphasis was on technical potential, such as biofuel production, utilization and environmental aspects. The Institute of Agricultural Technology and Biosystems Engineering ran vTI emission tests on diesel engines to evaluate the environmental impacts of biofuels. This testing facility is able to drive heavy-duty diesel engines in both stationary and dynamic test cycles, such as the European ESC and ETC. Additional analyses were conducted to determine the fine and ultra-fine particles, polycyclic aromatic hydrocarbons (PAH), aldehydes, ketones, and the usual regulated exhaust gas compounds. Ames tests were conducted to assess the mutagenic potential of tailpipe emissions. Previous study results showed that neat vegetable oils can render the exhaust high in mutagenic potency. Some of the non-regulated exhaust gas compounds were found to vary nonlinearly ...
The main challenges for PMOS ultra shallow junction formation remain the transient enhanced diffusion (TED) and the solid solubility limit of boron in silicon. It has been demonstrated that low energy boron implantation and spike annealing are key in meeting the 90nm technology node ITRS requirements. To meet the 65nm technology requirements many studies have used fluorine co-implantation with boron and Si"+ or Ge"+ pre-amorphization (PAI) and spike annealing. Although using BF_2"+ can be attractive for its high throughput, self-amorphization and the presence of fluorine, many studies have shown that the fluorine successfully reduce TED, its energy needs to be well optimized with respect to the boron's, therefore BF_2"+ does not present the right fluorine/boron energy ratio for the optimum junction formation. In this work we optimize the fluorine energy for boron energies down to 200eV. We show the dependence of optimized junction on Ge"+ energies of 2keV and ...
The ability to monitor the corrosion degradation of key components in fossil fuel power plants is of utmost importance for Futuregen and ultra-supercritical power plants. Fireside corrosion occurs in the high temperature sections of energy production facilities due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Problems occur when equipment designed for either oxidizing or reducing conditions is exposed to alternating oxidizing and reducing conditions. This can happen especially near the burners. The use of low NOx burners is becoming more commonplace and can produce reducing environments that accelerate corrosion. One method of addressing corrosion of these surfaces is the use of corrosion probes to monitor when process changes cause corrosive conditions. In such a case, corrosion rate could become a process control variable that directs the operation of a coal combustion or coal gasification ...
We present an atomistic simulation of the Ostwald ripening of extrinsic defects (clusters, {l_brace}1 1 3{r_brace}s and dislocation loops) which occurs during annealing of ion implanted silicon. The model describes the capture and emission of Si interstitial atoms to and from extrinsic defects of sizes up to thousands of atoms and includes a loss term due to the flux of interstitials to the recombining surface. Key input parameters of the simulation are the variations of the formation energy and of the capture efficiency with the size of the different defects. This model shows that the kinetics of the well-known dissolution of {l_brace}1 1 3{r_brace} defects is only driven by the recombination efficiency at the surface and the distance from the defects to the sample surface. We have subsequently used this model to study defect evolution in low and ultra low energy (ULE) B implanted Si during annealing. Defect dissolution occurs earlier and at smaller sizes in the ...
We present an atomistic simulation of the Ostwald ripening of extrinsic defects (clusters, #left brace#1 1 3#right brace#s and dislocation loops) which occurs during annealing of ion implanted silicon. The model describes the capture and emission of Si interstitial atoms to and from extrinsic defects of sizes up to thousands of atoms and includes a loss term due to the flux of interstitials to the recombining surface. Key input parameters of the simulation are the variations of the formation energy and of the capture efficiency with the size of the different defects. This model shows that the kinetics of the well-known dissolution of #left brace#1 1 3#right brace# defects is only driven by the recombination efficiency at the surface and the distance from the defects to the sample surface. We have subsequently used this model to study defect evolution in low and ultra low energy (ULE) B implanted Si during annealing. Defect dissolution occurs earlier and at smaller ...
The present paper describes the development of ultra-fine grains on the surface of AZ31 alloys caused by hydrogenation and dehydrogenation treatment, so-called HDDR process. Upon hydrogenation process, disproportionation reaction occurred in forming of MgH{sub 2}, Mg{sub 0.42}Al{sub 0.58}, and Al phases. In the following desorption process, the three phases were re-solved into the AZ31 alloy. As a result of the HDDR phenomena, the grain size of AZ31 alloy powders was reduced down to about 100 nm after the heat treatment at 350 C under a hydrogen pressure of 7 MPa for 24 h. The grain size tended to be increased with increasing process temperatures. In addition, the HDDR process was also applied to AZ31 alloy plates. By the HDDR process at 450 C, the grain size was reduced to less than 500 nm, where hydrogenated layer thickness was limited to be in the range of about 20 {mu}m from the surface. The Vickers hardness of AZ31 alloy plates was increased from 51.9 to 59.4 ...
Ultra fine tungsten carbide and cobalt powders were milled by high energy planetary ball mill at different ball to powder weight ratios (BPR) to produce particles of WC-10wt%Co hard metal in nanometer scale size. Microstructural characterizations by TEM show that the particle size of tungsten carbide was achieved to 32nm after milling at 15 BPR during 10h. In order to reduce the WC grain growth during the sintering process, tantalum carbide was added to the hard metal as a WC grain growth inhibitor. The nano hard metal powders were compacted at 200MPa pressure and sintered at 1370-1450degreeC temperatures in a high purity hydrogen atmosphere. The results show that the addition of 0.6wt% of TaC improves the hardness and fracture toughness from 1493 HV30 and 11.8MPam (for TaC free sample) to...
Samples of ultra-high molecular weight polyethylene (UHMWPE) and nylon 66, of grades suitable for use in medical prostheses, were subjected to irradiation using a /sup 60/Co source. The effects of a 10 Mrad dose on percentage crystallinity, tensile behaviour and dynamic mechanical response were established 3 days after irradiation at intervals over a one year period. Crystallinity in UHMWPE was found to increase progressively during this period with consequent changes in mechanical behaviour. It is proposed that the observed ageing process arises from the breakdown of metastable groups in the polymer, which are formed on irradiation, with consequent release of long inter-lamella tie chains. This removes an inhibition to crystal perfection processes, which can occur at room temperature in polyethylene. Infra-red spectroscopic evidence supports the proposal that the metastable species is peroxy or hydroperoxy and that this decomposes on ageing to a carbonyl group, ...
Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was {epsilon} {approx}7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.
Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was #epsilon# #approx#7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.
Of the many ways of detecting high redshift galaxies, the selection of objects due to their redshifted Ly-alpha emission has become one of the most successful. But what types of galaxies are selected in this way? Until recently, Ly-alpha emitters were understood to be small star-forming galaxies, possible building-blocks of larger galaxies. But with increased number of observations of Ly-alpha emitters at lower redshifts, a new picture emerges. Ly-alpha emitters display strong evolution in their properties from higher to lower redshift. It has previously been shown that the fraction of ultra-luminous infrared galaxies (ULIRGs) among the Ly-alpha emitters increases dramatically between redshift three and two. Here, the fraction of AGN among the LAEs is shown to follow a similar evolutionary path. We argue that Ly-alpha emitters are not a homogeneous class of objects, and that the objects selected with this method reflect the general star forming and active galaxy ...
Laser frequency stabilization giving a 500-Hz Allan deviation for a 2-ms integration time with drift reduced to 7 kHz/min over several minutes was achieved at 1536 nm in the optical communication band. A continuously regenerated spectral hole in the inhomogeneously broadened "4I_1_5_/_2(1)#->#"4I_1_3_/_2(1) optical absorption of an Er"3"+:Y_2SiO_5 crystal was used as the short-term frequency reference, while a variation on the locking technique allowed simultaneous use of the inhomogeneously broadened absorption line as a long-term reference. The reported frequency stability was achieved without vibration isolation. Spectral hole burning frequency stabilization provides ideal laser sources for high-resolution spectroscopy, real-time optical signal processing, and a range of applications requiring ultra-narrow-band light sources or coherent detection; the time scale for stability and the compatibility with spectral hole burning devices make this technique ...
The detection limit of Instrumental Neutron Activation Analysis (INAA), about a few microgram per kg, is not sufficient to determine iridium concentrations in most geological samples. Use of the coincidence counting of the 316 and 468 keV gamma-rays emitted during the decay of {sup 192}Ir, improved the sensitivity (0.01 microgram per kg). The high iridium content of the clay layers from the Cretaceous-Tertiary transition (KTB) has been considered as an evidence of the extra-terrestrial origin of the KTB mass extinction. However some results indicate that a significant part of the iridium content in sediments has a volcanic origin. Radiochemical Neutron Activation Analysis (RNAA) in some KTB samples and in basic and ultra-basic rocks show that, unlike in volcanic products, no PGE (platinoids) fractionation appears in KTB samples. The nearby chondritic PGE pattern supports an extra-terrestrial origin for the KTB iridium anomaly. 2 figs., 2 tabs., 37 refs.
The key to improving transmission-network security is faster response to contingencies. Now a new breed of pumped-storage plant - designed for ultra-fast response - may soon provide a tool dispatchers can use to improve network security. This type of plant can also substantially increase the effective capacity of existing transmission lines and improve the performance of thermal generating units. The Mt. Hope Waterpower Project, planned for Rockaway Township, NJ, 35 miles west of New York City, lies strategically adjacent to major load centers at the eastern end of the PJM control area and near the interconnection point with the New York Power Pool (NYPP). This location also is in an area deficient in significant generating facilities. Maximum design capacity of the project is 2000 MW, provided by six reversible pump/turbines, each with a nominal 340-MW rating. The upper reservoir, with a surface area of only 60 acres, provides 5000 acre-ft of active storage volume ...
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional and multi-component seismic area is being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended- reach jetting lance and other ultra-short radius lateral technologies. Improved completion efficiency, additional wells at closer spacings better estimates of oil-in-place will result in additional oil production by primary and enhanced recovery processes. Technical progress is described for field ...
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the other hand, for thinner ...
Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the other hand, for thinner ...
In the advance of fuel cell electric vehicles (EV), hybrid electric vehicles (HEV) can contribute to reduced emissions and energy consumption of personal cars as a short term solution. Trade-offs reveal better emission control for series hybrid vehicles, while parallel hybrid vehicles with different drive trains may significantly reduce fuel consumption as well. At present, costs and marketing considerations favor parallel hybrid vehicles making use of small, high power batteries. With ultra high power density cells in development, exceeding 1 kW/kg, high power batteries can be provided by adapting a technology closely related to consumer cell production. Energy consumption and emissions may benefit from regenerative braking and smoothing of the internal combustion engine (ICE) response as well, with limited additional battery weight. High power supercapacitors may assist the achievement of this goal. Problems to be solved in practice comprise battery management to ...
A new organic-inorganic hybrid membrane has been prepared with exceptional performance in dewatering applications. The only precursor used in the sol-gel synthesis of the selective layer was organically linked 1,2-bis(triethoxysilyl)ethane (BTESE). The microporous structure of this layer enables selective molecular sieving of small molecules from larger ones. In the dehydration of n-butanol with 5% of water, the membrane shows a high separation factor of over 4000 and ultra-fast water transport at a rate of more than 20 kg m{sup -2} h{sup -1} at 150C. This can be related to the high adsorption capacity of the material and the sub-micron thickness of the selective layer. The selectivity has now remained constant over almost one and a half years under continuous process testing conditions. Apart from the hydrothermal stability, the membrane exhibits a high tolerance for acid contamination. A slow performance decline in flux and separation factor is only observed at a ...
A comparison between the concepts of the hybrid electric vehicle (HEV) and the ultra low emission vehicle (ULEV) was presented. The ULEV uses a much larger engine compared to the HEV, but it uses a lower Kw generator/motor and inverter/charger to use the latest engine and battery technology. The underlying goal of the ULEV is to supply auxiliary power under start-up and heavy load conditions and to remove indirect systems such as steering, starting and blower control from the engine via small electric drives. The challenge is to build a ULEV that is robust enough to withstand any environmental conditions. Since the ULEV engine is larger, it can experience compartment temperatures greater than 125 degrees C, which limits the use of conventional filter capacitors. Nippon Chemi-Con has recently developed U787D, the world's first continuous 150 degrees C rated aluminum electrolytic capacitor designed to meet the ambient, ripple currents and vibration ...
The global production of steel is predicted to increase rapidly to meet future demands. In order to conserve the natural resources, certain measures must be taken. These include perfecting the recycling of steel, improving the performance to extend the life of the material, and reduce the need for massive production of steel by increasing the strength of the material. This paper presented a design concept for ultrafine complex microstructure steel. The National Research Institute for Metals in Japan has worked on a project which investigated 800 MPa ferrite steel for welded structures with a chemical composition similar to 400 MPa-class plain carbon steel. The doubled strength was attributed to grain refinement. Novel welding techniques were also used for joining the ultrafine microstructure. In this study, low carbon Si-Mn ferrite-pearlite steels were subjected to a thermo-mechanical treatment to produce a microstructure of 1 micron order ultrafine grain ferrite plus finely dispersed ...
Infrared astronomical instruments require absorptive coatings on internal surfaces to trap scattered and stray photons. This is typically accomplished with any one of a number of black paints. Although inexpensive and simple to apply, paint has several disadvantages. Painted surfaces can be fragile, prone to shedding particles, and difficult to clean. Most importantly, the vacuum performance is poor. Recently a plasma enhanced chemical vapor deposition (PECVD) process was developed to apply thick (30 {micro}m) diamond-like carbon (DLC) based protective coatings to the interior of oil pipelines. These DLC coatings show much promise as an infrared black for an ultra high vacuum environment. The coatings are very robust with excellent cryogenic adhesion. Their total infrared reflectivity of < 10% at normal incidence approaches that of black paints. We measured outgas rates of <10{sup -12} Torr liter/sec cm{sup 2}, comparable to bare stainless steel.
Present and future ultra-high-energy-cosmic-ray facilities (e.g., the Pierre Auger Observatory with South and North components) and TeV-gamma-ray telescope arrays (e.g., HESS/VERITAS and CTA) have the potential to set stringent indirect bounds on the nine Lorentz-violating parameters of nonbirefringent modified Maxwell theory minimally coupled to standard Dirac theory. Theoretically, the most interesting case is isotropic Lorentz violation, which is described by a single parameter [taken to vanish for the case of the standard Lorentz-invariant theory]. It appears possible to obtain in the future an upper (lower) indirect bound on this single isotropic Lorentz-violating parameter at the +10^{-21} (-10^{-17}) level. Comparison is made with existing and future direct bounds from laboratory experiments. The possible physics implications of upper bounds at the 10^{-21} level are also briefly discussed.
A 25m wind turbine blade was tested to failure when subjected to a flapwise load. With the test setup, it was possible to test the blade to failure at three diffe-rent locations. The objective of these tests is to learn about how a wind turbine blade fails when exposed to a large flapwise load and how failures propagate. The report shows also results from ultra sonic scan of the surface of the blade and it is seen to be very useful for the detection of defects, especially in the layer between the skin laminate and the load carrying main spar. Acoustic emission was successfully used as sensor for the detection of damages in the blade during the test. The report contains measurements of the total deflection of the blade, the local deflection of the skin and the load carrying main spar and also measurement of strain all as a function of the applied load and up to failure of the blade. The 'post mortem' analysis and description of how the damages ...
Graphite fluoride (CF{sub x}) is investigated as an additive for WS{sub 2} thin films to reduce its sensitivity to moisture. The films are grown onto hardened 440C stainless steel disks by pulsed laser deposition using the 248 nm line from an excimer laser. Substrate temperature and additive concentration are varied to control film chemistry and crystal structure. The effect of relative humidity (i.e., < 1 to 85% RH) on friction is evaluated. Coatings grown at RT from targets with a low concentration of CF{sub x} exhibit ultra-low friction (ULF) behavior in dry air (i.e., {mu} {<=} 0.01), but friction increases with RH. Mechanisms for the ULF behavior are proposed which suggest that further reductions in friction are possible. Films grown at 300 C or with higher concentrations of CF{sub x} are relatively insensitive to humidity, but have more typical friction coefficients ({mu} {<=} 0.04) in dry air. (orig.)
Free-electron lasers as scientific instruments are reviewed. The present status and future prospects are delineated with attention drawn to the size, complexity, availability, and performance capability of this new tool. The Free-Electron Laser (FEL) was proposed by John Madey in 1970 (1), although earlier work, relevant to the concept, had been performed by Motz (2) and by Phillips (3). Experimental demonstration was achieved by Madey, et. al. in 1975 and 1976 (4). Since that time, FELs of diverse configurations have been operated at several laboratories around the world. At present, FEL development is focused in two directions: in constructing reliable FELs for scientific research and in extending FEL capability to vacuum ultra-violet (VUV) and even shorter wavelengths. In this article we shall only very briefly review the principles of an FEL, putting emphasis on those aspects that limit performance, after which we shall discuss the applications, present status ...
We have researched several new focused ion beam (FIB) micro-fabrication techniques that offer control of feature shape and the ability to accurately define features onto nonplanar substrates. These FIB-based processes are considered useful for prototyping, reverse engineering, and small-lot manufacturing. Ion beam-based techniques have been developed for defining features in miniature, nonplanar substrates. We demonstrate helices in cylindrical substrates having diameters from 100 {micro}m to 3 mm. Ion beam lathe processes sputter-define 10-{micro}m wide features in cylindrical substrates and tubes. For larger substrates, we combine focused ion beam milling with ultra-precision lathe turning techniques to accurately define 25-100 {micro}m features over many meters of path length. In several cases, we combine the feature defining capability of focused ion beam bombardment with additive techniques such as evaporation, sputter deposition and electroplating in order to ...
For rational use of energy resources, the process technology which allows harmonization and multiplication of conflicting characteristics was developed for development of new ceramic system materials. This paper summarizes the result in fiscal 1997. On a structural reaction process among creation technologies of ultra-reliable structure, study was made on structure control and hot-working technology through atmosphere control in ceramics synthesis. On basic technology for analysis and evaluation, study was made on the effect of particle bridging on strengthening and toughening of ceramic materials. Study was also made on a toughness expression mechanism, FEM model analysis of particle bridging, and crack growth resistance of ceramics. On control of solid solution precipitation, new alumina ceramics with high strength, hardness and wear resistance was obtained by transgranularly precipitating nano-size particles from a fine-grain high-density matrix through an ...
The UTST (University of Tokyo Spherical Tokamak) device was constructed for the purpose of exploring the formation of ultra-high beta ST (Spherical Tokamak) plasma using the double null plasma merging method. When two plasmas merge together to form a single plasma, magnetic field lines reconnect, and the magnetic field energy is converted to the plasma kinetic energy, increasing the plasma beta. The merging start-up has been demonstrated in the TS-3/4, START and MAST devices using coils inside the vacuum vessel and TS-3 plasma obtained 50% beta. In order to demonstrate the start-up in a more reactor relevant situation, UTST has all poloidal field coils outside the vacuum vessel. The first plasma experiment on the UTST was performed from December, 2007. In the result, the plasma obtained 10 kA by using only outer PF coils and single ST was generated at the lower area (z=-0.3 - -1.0[m]) close to a washer gun. This result suggests that another washer gun on the top of ...
We present an approach for fabrication of intentionally positioned epitaxial InAs QDs in a micron sized light emitting diode. For site-selective growth, a combination of molecular beam epitaxy (MBE) and focused ion beam (FIB) implantation technology in an all-ultra-high-vacuum (UHV) setup has been employed. Single dot occupancy of almost 55 % on FIB patterned nano-depressions was successfully achieved. Thereafter, carrier injection and subsequent radiative recombination from the positioned InAs/GaAs self-assembled QDs was investigated by embedding these QDs in the intrinsic part of a GaAs-based micron sized p-i-n junction device. Few or single dot are expected to be electrically addressed in these devices. We report results from electroluminescence (EL) measurement which proves the single dot characteristics of our device. The EL spectra consist of sharp emission lines and their dependence on injection current shows linear behavior for exciton and quadratic ...
CuAg core-shell nanoparticles are synthesized by ultra-high vacuum thermal evaporation. We show on this system how the Energy-Filtered Transmission Electron Microscopy (EFTEM) technique allows one to improve the characterization by precisely pointing out the formation of core-shell arrangements in bimetallic nanoparticle assemblies. A criterion to measure the shell thickness from EFTEM images on unique core-shell nanoparticles is defined, that can be used for core-shell nanoparticles of any sizes, with shell thicknesses over 1 nm. It is based on the intensity variation along a line drawn across a core-shell nanoparticle on a EFTEM image. This criterion has been validated by a close comparison of the shell thickness measurements performed in this work and the ones obtained by acoustic micro-Raman spectroscopy. Using this criterion, we report a strong correlation between the size of the Cu cores and the formation of the core-shell arrangements in the nanoparticle ...
In this study, the exhaust gas from a common-rail direct injection diesel engine was investigated both upstream and downstream warm-up catalytic converters (WCC). Three different types of ultra-low sulfur fuels (ethanol-diesel blend, ethanol-diesel blend with cetane improver and pure diesel) were tested in this study. The objective of the work was to study the engine performance and the formation of THC (total hydro carbon), CO (carbon monoxide), NO{sub x} (nitrogen oxides), smoke and PM (particulate matters) when using these fuels. THC and CO emissions of the ethanol-diesel blend fuels were slightly increased, and about 50-80% mean conversion efficiencies of THC and CO on catalysts were achieved in the ECE R49 13-mode cycle. Smoke was decreased by more than 42% in the entire ECE 13-mode cycles. From the measurement of scanning mobility particle sizer (SMPS) for the particle size range of 10-385 nm, the total number and total mass of the PM of the ethanol-diesel ...
The Centre's new structure, implemented in July 1997 is now operating well. CMTE Development Limited is now the legal entity for the CRC and replaces the previously unincorporated joint venture. CMTE has ten core participating organisations. Roche Highwall Mining Pty. Ltd., withdrew participation during the year. The annual report describes its structure and management and various cooperative links. It outlines research programs in the following areas: mining; geological sensing; automation; reliability and maintenance; and coal processing. Projects include: developing an ultra-short-radius drilling machine for drainage of methane gas from coal seams; developing techniques for improved drilling speed and accuracy to reduce costs for gas drainage holes in underground coal mining; developing draglines; developing geophysical logging tools; developing autonomous control of underground vehicles such as coal-haul-dump (LHD) and haulage trucks, developing tools ...
Most of the organic electronic devices are nowadays fabricated under poor vacuum conditions. In this regard, there is only little knowledge about the impact of contamination of the metal electrode on the charge injection barrier in this kind of electronic devices. In our study we have performed X-ray and ultra violet photoemission spectroscopy (XPS, UPS) on interfaces between the organic semiconductor -sexithiophene and sputter cleaned (ideal) metals as well as contaminated (realistic) metals. As metal substrates we have used silver, gold, palladium, and platinum. These metals provide us a wide range of metal work functions from 4.2 eV for silver up to 5.5 eV for platinum. For all interfaces of -sexithiophene and contaminated metals we have observed a reduction of the interface dipole and the hole injection barrier. The charge injection barrier in all four cases is almost independent of the underlying metal (within an error of 0.2 eV) and the interface dipole ...
The development of modern techniques for the cooling and the manipulation of atoms in recent years, and the possibility to create Bose-Einstein condensates and degenerate Fermi gases and to load them into regular optical lattices or disordered optical potentials, has evoked new interest for the disorder-induced localization of ultra-cold atoms. This work studies the transport properties of matter waves in disordered optical potentials, which are also known as speckle potentials. The effect of correlated disorder on localization is first studied numerically in the framework of the Anderson model. The relevant transport parameters in the configuration average over many different realizations of the speckle potential are then determined analytically, using self-consistent diagrammatic perturbation techniques. This allows to make predictions for a possible experimental observation of coherent transport phenomena for cold atoms in speckle potentials. Of particular ...
Ultra-fine ZnAl2O4 spinel hydrogel precursor synthesized from mixed salt solutions of Zn^2^+ and Al^3^+ ions using ammonium hydroxide-hexamethylenetetramine as basic media for co-precipitation was used as bonding material and sintering aid for pure alumina system. The hydrogel powder exhibited some well-defined ZnAl2O4 spinel phases at 800^oC. Alumina compacts were fabricated by incorporating small proportions of the precursor in alumina powder and firing at different temperatures (1350-1500^oC). The degree of densification was studied by measurement of fired shrinkage, apparent porosity, bulk density and cold crushing strength. Phase compositions and microstructural features of sintered samples were evaluated by XRD and SEM respectively. Addition of 0.2% hydrogel powder to alumina exhibit...
Tar sand bitumen is petroleum-based ultra-heavy oil, and has a great amount of reserve like coal. However, there are still a lot of problems for its highly effective utilization. This paper discusses whether the light components in bitumen show independent behavior during the thermal cracking of heavy components, or not. Solvent effect and reaction mechanism during the thermal cracking are also derived from the change of their chemical structures. Athabasca tar sand bitumen was separated into light and heavy fractions by vacuum distillation based on D-1660 of ASTM. Mixtures of the both fractions at various ratios were used as samples. Negative effect of the light fraction on cracking of the heavy fraction was observed with dealkylation and paraffin formation Polymerization of the dealkylated light fraction to the heavy fraction was suggested due to lack of hydrogen in the thermal cracking under nitrogen atmosphere, which resulted in the formation of polymer. 3 ...
The automotive paints could be generally differentiated by color, layer sequence and chemistry of the paint layers comprising each of the topcoat and the primer system. The successful identification of hit-and-run a and traffic accidental vehicles from evidential paint fragments is greatly facilitated with a comprehensive laboratory collection of reference paint samples and the technique for direct analysis without sample preparation. The Pyrolysis-Gas Chromatography(PGC) is a precise and reliable method for performing both quantitative and qualitative analysis of polymeric materials and forensic samples. Our Forensic Laboratory is conducting the examination and identification of 73 reference paint samples; 4 colors of each domestic automotive make that is poplar in Korea, by Curie Point Pyrolyzer(JHP-3) and GC with capillary column(ultra alloy-5). This method can be used not only to compare paint traces with their suspected sources, but also to identify the type, ...
Wastewater from a food-manufacturing plant with a low concentration of organic matter was treated at 37 centigrade in an anaerobic fluidized-bed reactor or in an upflow anaerobic sludge blanket. As the influent TOC (total organic carbon) concentration decreased, the TOC removal efficiency in these reactors decreased from 85% to 65%. The concentration of suspended solids in the effluent could be reduced to 20 mg/l, which corresponded to 7% of that in the influent. The effluent from both reactors was treated aerobically in a fixed-bed reactor. The TOC concentration and optical density of effluent from the aerobic treatment were reduced to 5 mg/l and 0.005, respectively. When the effluent treated anaerobically or aerobically was passed over an activated carbon column, the effluent TOC concentration was reduced to 2 to 3 mg/l. The conductivity in raw wastewater was remarkably reduced on an ion-exchange resin column. Ultra-pure water for industrial use was obtained by ...
The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this PDR document and the set of SDD documents will define and ...
Negative ion electrospray ionization (ESI) coupled with high field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) allows for the direct detection of acidic NSO compounds in petroleum. The technique requires no chromatographic separation, is able to distinguish 18 different compound classes (e.g., neutral nitrogen, carboxylic acids and oxygenates), and can identify {approx}14,000 distinct masses by ultra-high mass resolution and mass accuracy. We previously studied three crude oils from different geological origins [Organic Geochemistry 33 (2002b) 743-759]. Here, we expand our research by comparing two source-equivalent Smackover oils of different levels of thermal maturity. We observe clear differences in the distribution of NSO compound classes, types (number of rings plus double bonds within a class), and number of alkyl carbons. With increasing thermal stress, the relative amount of sulfur and oxygen containing compounds decreases, ...
Unipolar induction (UI) is a fundamental physical process, which occurs when a conducting body transverses a magnetic field. It has been suggested that UI is operating in RX J0806+15 and RX J1914+24, which are believed to be ultra-compact binaries with orbital periods of 5.4 min and 9.6 min respectively. The UI model predicts that those two sources may be electron cyclotron maser sources at radio wavelengths. Other systems in which UI has been predicted to occur are short period extra-solar terrestrial planets with conducting cores. If UI is present, circularly polarised radio emission is predicted to be emitted. We have searched for this predicted radio emission from short period binaries using the VLA and ATCA. In one epoch we find evidence for a radio source, coincident in position with the optical position of RX J0806+15. Although we cannot completely exclude that this is a chance alignment between the position of RX J0806+15 and an artifact in the data ...
Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas after a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are used at various beam ...
Early recognition of recurrence and work-up of clinically indeterminate lesions may be impaired after reconstruction with silicone implants due to superimposition of the implant or to scarring. This study was undertaken to evaluate the use of contrast-enhanced MRI in patients with silicone implant after breast cancer. Contrast-enhanded MRI was offered to 169 patients. Comparative two- to three-view mammography was also performed in 169 patients, as well as comparative sonography in 144 patients. Conventional imaging and clinical examination detected only 8/13 recurrences, whereas 12/13 were detected by MRI. One recurrence had been visible as a strongly enhancing 2-mm dot in a previous examination (2 years before), but was not called. It was therefore counted as false negative. In addition, multicentricity was detected by MRI alone in two of three cases. MRI correctly diagnosed scar tissue in all cases with indeterminate findings. However, due ...
Nerve growth factor (NGF), a survival factor for neurons enforces pain by sensitizing nociceptors. Also in the pancreas, NGF was associated with pain and it can stimulate the proliferation of pancreatic cancer cells. Hepatic stellate cells (HSC) respond to NGF with apoptosis. Transforming growth factor (TGF)-b, one of the strongest pro-fibrogenic activators of pancreatic stellate cells (PSC) induced NGF and its two receptors in an immortalized human cell line (ihPSC) and primary rat PSC (prPSC) as determined by RT-PCR, western blot, and immunofluorescence. In contrast to HSC, PSC expressed both NGF receptors, although p75NTR expression was weak in prPSC. In contrast to ihPSC TGF-b activated both Smad signaling cascades in prPSC. NGF secretion was diminished by the activin-like kinase (ALK)...
Variations in skin perfusion are easily detected by laser speckle contrast maps, but a robust interpretation of the information has been lacking. We show that multiple-exposure laser speckle methods produce the same spectral information as laser Doppler methods when applied to targets with embedded moving scatterers. This enables laser speckle measurements to be interpreted more quantitatively. We do this by using computer simulation of speckle data, and by experimental measurements on Brownian motion and skin perfusion using a laser Doppler system and a multiple-exposure laser speckle system. The power spectral density measurements of the light fluctuations derived using both techniques are exactly equivalent. Dermal perfusion can therefore be measured by laser Doppler or laser speckle contrast methods. In particular, multiexposure laser speckle can be rapidly processed to generate a full-field map of the perfusion index proportional to the ...
In a prospective study, 58 patients with carcinomas of the bladder were examined by CT and MRI; in 48, gadolinium-DTPA was administered intravenously. MRI provided exact staging in 89%, compared with 80% with CT. There was 13% over-staging with CT and 11% with MRI. MRI, unlike CT did not result in any under-staging. In 36 patients a quotient could be calculated from the signal intensity of the tumour and surrounding soft tissues both before and after the intravenous contrast medium and the increased quotient after contrast administration could be estimated. There was a significant increase in the tumour/muscle quotient with a mean of 72#+-#22% (minimum 43%, maximum 153%), corresponding to a marked increase of the signal form the tumour when compared with the precontrast images. This had the following advantages compared with CT: Accurate differentiation between superficial and intramural spread. MRI was better than CT at demonstrating tumours ...
With an objective to perform three-dimensional analysis with high accuracy in using the electromagnetic exploration method, characteristics in electromagnetic response were analyzed, and conditions for acquiring necessary data were discussed. The discussion defined a parameter called `response anomaly` which uses response from media to standardize response only from substances with abnormal resistivity. The receivers were located uniformly on the same plane, and the response anomaly was derived from electromagnetic response from each of the three horizontal and vertical components at each receiving point, which was expressed as a contour map. The parameter for the abnormal body was consisted of location and resistivity contrast with media. Discussions using the contour map were given on the response when these factors for the parameter were varied. As a result, it was found that the response anomaly appears in the form that reflects the abnormal body, and the ...
Most palladium thin film based hydrogen gas sensors have response and recovery times that are too long to make them useful in vehicular and stationary gas leak detection applications. In contrast, a palladium-silver thin film based microcantilever (MC) hydrogen gas microsensor is reported herein with near ideal response characteristics for use in these hydrogen economy related applications. Specifically, 3-10 second response and recovery times have been measured for these sensors in contrast to previous sensor response measurements of several to tens of minutes using Pd thin film and MC based sensing techniques. The much reduced response times observed in the present study are attributed to a wet chemical Pd-Ag thin film deposition technique and a gas conditioning protocol that produces a highly nanostructured, porous film that rapidly adsorbs and desorbs H2, allowing rapid equilibration with the H2 concentration in the surrounding air. The wet ...
The purpose of this project was to design, build, and characterize the performance of a volume breast ultrasound (VBUS) scanner that images the pendant breast. VBUS scanner design includes a: 1) clinical ultrasound scanner and transducer; 2) scanning table with a hole for the pendant breast; 3) rotational gantry; 4) probe mounting assembly; 5) compressionless breast stabilization device; 6) acquisition, control, reconstruction, and display software. Performance assessment characterized a variety of parameters including: spatial resolution, uniformity, and distortion using high and low contrast test objects in both horizontal and vertical scanning modes. The VBUS scanner modules have been constructed and initial performance evaluated. Approximately 300 scans are acquired over 360 degrees in 18 seconds. Reconstruction requires 25 ms per slice. Test object images depicted hyper- and hypo-echoic masses and demonstrated good resolution, soft tissue ...
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with prototype animal PET/MRI ...
Differentiating a benign from a malignant lesion by information such as density data, or signal intensities or echo gradients, is not possible with CT, nor MRI, nor ultrasonography. Only some lesions show characteristic signs. Inflammations cannot be difscriminated from malignant tumors. CTs of small tumors in particular are so poor in contrast that it is much more difficult to detect tumors or discriminate them from other lesions, as compared to MR images or ultrasonographs. CT does not detect surface tumors, but is more sensitive than MRI or US in detecting discrete cortical bone lesions. The same applies to small calcified tumors. MRI however is most sensitive in detecting tumor volumes in the yellow marrow, and is the best modality for evaluation of extraossal extension of tumors. CT yields better results than MRI if applied for simultaneous screening of lymph node metastases in the lower neck. MRI frequently is spoilt by movement artefacts. High-resolution, ...
Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 {mu}s exposure and spatial resolution of 10 {mu}m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were revealed. These include processes such as the initiation of nucleated melting and other ...
Heterogeneous gasless reactive systems, including high-energy density metal-nonmetal compositions, have seen increasing study due to their various applications. However, owing to their high reaction temperature, short reaction time, and small scale of heterogeneity, investigation of their reaction mechanisms and kinetics is very difficult. In this study, microstructural changes and the kinetics of product layer growth in the W-Si system was investigated using a high-speed x-ray phase-contrast imaging technique. Using the Advanced Photon Source of Argonne National Laboratory, this method allowed direct imaging of irreversible reactions in the W-Si reactive system at frame rates up to 36 000 frames per second with 4 #mu#s exposure and spatial resolution of 10 #mu#m. Details of the Si melt and reactions between W and Si, that are unable to be viewed with visible-light imaging, were revealed. These include processes such as the initiation of nucleated melting and other ...
We reported three cases of acute intracranial tuberculosis including miliary tuberculosis, basal meningitis, tuberculomas and neuritis of cranial nerves. All patients had native and contrast enhanced CT and MRI scans. MRI revealed more granulomas and a better imaging contrast in the detection of basal meningitis. Neuritis was diagnosed only with the MRI. MRI scans should be prefered as the imaging procedure in clinically presumed intracranial tuberculosis. (orig.) [Deutsch] Die Befunde von drei Patienten mit intrakranieller Tuberkulose (intrakranielle Miliartuberkulose, Meningitis tuberculosa, Neuritis und Tuberkulome) in der Magnetresonanztomographie (MRT) wurden mit der Computertomographie (CT) verglichen. Sowohl die MRT als auch die CT wurden nativ und nach Kontrastmittelgabe durchgefuehrt. Die MRT zeigte sich im Nachweis von Granulomen insbesondere im Bereich des Hirnstamms ueberlegen. Ebenso wurde ein hoeherer Bildkontrast bei der ...
The MRI and CT appearances in 48 patients with histologically confirmed benign and malignant pleural abnormalities were compared retrospectively. Abnormal pleural changes were shown in 47 out of the 48 patients by high signal intensity of the pleura in T_2-weighted sequences and in contrast enhanced T_1-weighted sequences on MRI. CT showed abnormalities in 45 out of 48 patients. Delineation of pleural and pulmonary changes by CT was possible in 13 out of 23 cases, and pleural disease from effusions in 15 out of 28 cases. T_2-weighted MRI was successful in 14 out of 23 and 4 out of 28 cases, respectively. T_1-weighted images after contrast were successful in 20 out of 23 and 22 out of 28 cases, respectively. Indications of malignant pleural disease were the presence of mediastinal or circumferential involvement or involvement of the entire pleura, thickness of more than 10 mm and nodular changes. The most reliable sign of malignancy was ...
Purpose. To evaluate injection-associated pain, safety, and efficacy with the isotonic contrast medium iodixanol (Visipaque 270 mg I/ml) compared with iopromide (Ultravist 300 mg I/ml) in femoral arteriography. Methods. A multicenter, double-blind, randomized, parallel-group clinical investigation was carried out in 54 hospitals in Europe. Of the patients evaluated, 1225 received iodixanol and 1227 iopromide in conventional and/or digital subtraction angiography. Results. The iodixanol group reported statistically significantly less injection-associated pain (0.9%) than the iopromide group (9.5%) (p<0.001). Further, 4.1% in the iodixanol group experienced pain and/or severe heat sensation vs 19.8% in the iopromide group (p<0.001). In the iodixanol group, 1.8% of the patients experienced contrast-related adverse events vs 2.4% in the iopromide group (p=NS). Overall diagnostic information was optimal for 94.1% in the iodixanol group and ...
Retention and/or reincorporation of plant residues increases soil organic nitrogen (N) levels over the long-term is associated with increased crop yields. There is still uncertainty, however, about the interaction between crop residue (straw) retention and N fertilizer rates and sources. The objective of the study was to assess the influence of straw management (straw removed [SRem] and straw retained [SRet]), N fertilizer rate (0, 25, 50 and 75kgNha^-^1) and N source (urea and polymer-coated urea [called ESN]) under conventional tillage on seed yield, straw yield, total N uptake in seed+straw and N balance sheet. Field experiments with barley monoculture (1983-1996), and wheat/barley-canola-triticale-pea rotation (1997-2009) were conducted on two contrasting soil types (Gray Luvisol [Typi...
Differential phase-contrast X-ray imaging has been performed in a Talbot-Lau configuration, where a multiline X-ray source was used instead of a combination of a hard-X-ray multiple slit and a normal focus X-ray generator. When the multiple slit is used, a high aspect ratio structure is needed and slit width should be below 10 ?m for its function. The fabrication and use of such a multislit can be omitted using the presented configuration. The multiline X-ray source was developed by making grooves on a tungsten rotating anode, which was irradiated by an electron beam to generate X-rays. An array of 10?m line sources with a pitch of 30?m was formed and combined with a 4.5 ?m pitch phase grating and a 5.3 ?m pitch amplitude grating to generate differential phase contrast. With a total exposure time of 40 s, a differential phase image depicting cartilages was obtained. (author)
The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly to both the results of the contrast sensitivity test ...
A technique was developed that permits fluid flow to be visualized even where the flow is completely shrouded by metal. The technique employs real-time neutron radiography, which is similar to x-ray radiography except a collimated beam of neutrons is used. Various combinations of neutron-opaque tracer materials were tested with neutron-transparent fluid. Neutron opaque tracers, such as solid particles, fluid droplets, and streaklines were imaged through metal walls as they convected in neutron-transparent ambient fluid. Visualization of bubbles/voids were evaluated for possible future applications. Surface-flow patterns were also imaged by using neutron-opaque tufts. These techniques were evaluated for image contrast, resolution, and the ability to accurately track fluid flow fields. The techniques were also modeled to optimize contrast in various flow configurations. Imaging techniques such as real-time video, high speed video, and ...
A technique was developed that permits fluid flow to be visualized even where the flow is completely shrouded by metal. The technique employs real-time neutron radiography, which is similar to x-ray radiography except a collimated beam of neutrons is used. Various combinations of neutron-opaque tracer materials were tested with neutron-transparent fluid. Neutron opaque tracers, such as solid particles, fluid droplets, and streaklines were imaged through metal walls as they convected in neutron-transparent ambient fluid. Visualization of bubbles/voids were evaluated for possible future applications. Surface-flow patterns were also imaged by using neutron-opaque tufts. These techniques were evaluated for image contrast, resolution, and the ability to accurately track fluid flow fields. The techniques were also modeled to optimize contrast in various flow configurations. Imaging techniques such as real-time video, high speed video, and ...
Purpose: With intracranial tumors a flat, contrast-enhancing, probably dural structure adjacent to the tumor can occasionally be observed on gadolinium-DTPA enhanced MR images. Therefore we have attempted to evaluate a tumor infiltration of this enthancement on MRI. Material and Methods: This study included 50 patients. 19 patients had a dural thickening at the tumor base (13 meningiomas and 6 metastases), while 31 patients did not (12 meningiomas and 19 metastases). Studies included plane T_2-weighted spin echo (SE) images as well as T_1-weighted axial, coronal, or sagittal plains with and without contrast agent. Histopathological examinations, were done on the tumor base adjacent to the dura mater. Results: 7 of 12 meningiomas showed a meningeal thickening on MRI with histopathologically proven tumor infiltration as did also 5 of 6 metastases. But 3 of 12 meningiomas and 15 of 19 metastases without dural thickening at the tumor base also ...
We developed a new breast surface coil for the supine position. The subjects consisted of 9 patients with breast cancer varying from 46 to 60 years of age (average: 52). The cancer image of the SPGR (CE+) method was compared with that of the FSMTC (MTC-SPGR (CE+)) method and that of the FSMTC (MTC-SPGR with fat-saturation (CE+)) method in the sagittal section after injection of Gd-DTPA (0.1 mmol/kg). Quantitative analyses were performed before and after injection of Gd-DTPA in 6 patients. Three patients were excluded from the quantitative analyses owing to the clear detection of tumors in the fat tissue. Signal intensity measurements were systematically performed in each region of interest (ROI), i.e. the cancer lesion, the surrounding mammary gland. Statistical analyses showed significant differences between the lesions using the FSMTC (MTC-SPGR (CE+)), and the FSMTC (MTC-SPGR with fat-saturation (CE+)) methods and the lesions using the SPGR (CE+) method after injection of ...
Described is the diagnosis for the cancer extension of cholangiocarcinoma by various imaging techniques and processes to support the current surgical procedure based on preoperative biliary drainage. The cancer tends to locally extend horizontally and/or vertically and its diagnosis is important for surgical indication. For the indication, multi-detector raw CT (MDCT) and MR cholangio-pancreatography (MRCP) are useful and particularly, the former can give multi-phase (arterial, portal and delayed) images to reconstruct multiplanar (MPR) and CT angiographic 3D images, which have made the previous invasive examinations like angiography and percutaneous transportal contrasting unnecessary. MDCT and MRCP can almost complete the diagnosis of the extension. The operative procedure is decided dependently on the site of the lesion, and of which diagnosis, whether it is hepatic hilar/on upper bile duct or middle/lower ductal, is different. MDCT-MPR and MRCP are virtually ...
CT scans were performed on 25 patients suspected of sustaining ranal trauma. The utility of CT in both detecting renal damage and appraising the gravity of injuries was assessed. Nowadays, in fact, nephrectomy or reserved for lesions devastanting the kidney parenchyma or rupturing the renal pedicle; so it is very important to identyfy both the purposes of a better planned therapeutic approach. CT does both, being more accurate than urography in the detection of renal fractures, intra or extraparenchymal hematomas and contrast media extravasation. Urography very often shows aspecific lesion patterns and sometimes it is also falsely negative. In the present series CT was more reliable than angiography itself, particulary in the diagnosis of extra-renal hematic collections, contrast media extravasation and injuries to the other abdominal organs. Although CT may arouse the suspicion of and sometimes correctly diagnose vascular lesions, such as ...
The aim of this study was to assess the body weight-tailored contrast material injection protocol for 64-detector computed tomography (CT) to maintain optimal coronary CT attenuation. A total of 60 patients who underwent CT coronary angiography were assigned to one of three groups: protocol A, total of 0.7 ml kg"-"1 with 300 mg I/ml iodine concentration; protocol B, total of 0.6 ml kg"-"1 with 350 mg I/ml; protocol C, total of 0.7 ml kg"-"1 with 350 mg I/ml. The injection duration was 10 s in all patients. The proportion of intracoronary attenuation values >325 Hounsfield unit (HU) was compared on a per-vessel and per-patient basis. The attenuation value was significantly more likely to exceed 325 HU with protocol C (95% for reader 1 and 90% for reader 2) than with protocol A or B on the per-vessel analysis (P325 HU) with 64-detector CT when using an injection duration of 10 s. (author)
Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, ...
Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, NPS and DQE can reveal small changes ...
The objective of this study was to develop a method for 3D subtraction CT angiography and to optimize the visualization after semiautomatic segmentation. Ten patients with aneurysms of the abdominal aorta were examined using spiral CT. To reconstruct the vessels, as well as adjacent organs such as the liver and kidneys, one image data volume was acquired before and after injection of the contrast agent. The CT scans were obtained with a Siemens Somatom Plus 4. To improve the results of automatic segmentation, as well as visualization by maximum intensity projection (i.e. removal of bony structures), subtraction of both image volumes is necessary. However, small translation shifts disturb the subtraction process and produce artificial contours. To calculate the disparities along the three coordinate axes of two corresponding image volumes, a cepstrum filter is applied to a pair of image volumes. After detection of the disparities, which manifest as bright spots, the ...
The 1.04 GeV-proton elastic scattering from /sup 40/Ca is studied in the framework of the coherent density fluctuation model (CDFM). The calculations are carried out in the Glauber theoretical scheme with three different charge densities. It is shown that: i) the account of the flucton correlations leads to results considerably different from those obtained in the independent particle Glauber approach (IPGA); ii) in contrast to the case of IPGA the use of a more realistic density improves the agreement of CDPM-results with the experimental data.
The 1.04 GeV-proton elastic scattering from "4"0Ca is studied in the framework of the coherent density fluctuation model (CDFM). The calculations are carried out in the Glauber theoretical scheme with three different charge densities. It is shown that: i) the account of the flucton correlations leads to results considerably different from those obtained in the independent particle Glauber approach (IPGA); ii) in contrast to the case of IPGA the use of a more realistic density improves the agreement of CDPM-results with the experimental data. (orig.).
In this letter we present a derivation, from the D0-brane picture, of the background monopole field and in general of the full dynamics of the Yang-Mills theory on the dielectric D2-brane of Myers. To do this we study the large N limit of the fuzzy sphere relevant to the dielectric solution. In contrast to the usual interpretation where the commutative D2-brane picture arises directly from the large N limit of the D0-brane picture, we find that a residual non-commutativity must be preserved in order to make the connection by means of the Seiberg-Witten map.
Summary The First Nations people of British Columbia experience reincarnation as a revitalization of their culture. This article documents the perseverance of reincarnation experiences among the Beaver, Witsuwit'en, and Gitxsan peoples of British Columbia, as well as my own growth in understanding such experiences. It recounts examples of rebirth cases. It explains what rebirth experiences mean to the First Nations people. It describes how these experiences are embedded in their perception of this world and embodied in their beliefs of spiritual realms, which include the interconnected and parallel worlds of fish and land animals, on this world and in spiritual dimensions. While the rebirth worldview contrasts with that of the Western scientific world, this is a worldview I have come to en...
Search engine researchers typically depict search as the solitary activity of an individual searcher. In contrast, results from our critical-incident survey of 150 users on Amazon's Mechanical Turk service suggest that social interactions play an important role throughout the search process. Our main contribution is that we have integrated models from previous work in sensemaking and information seeking behavior to present a canonical social model of user activities before, during, and after search, suggesting where in the search process even implicitly shared information may be valuable to individual searchers.
Major factors that contribute to maximized impact resistance of semicrystalline engineering polymers include increased matrix molecular weight, minimal rubber glass-transition temperature, and optimal rubber-particle size, which depends on matrix type. Additional constraints are posed by the limitations of available materials and commercial requirements. Expanding the understanding of impact-modified crystalline engineering polymers will further extend their property ranges and utility. This chapter describes the phenomenology of certain factors, illustrates a new technique to measure rubber particle size, and contrasts the fracture mechanisms of poly(butylene terephthalate), nylon 66, and polyacetal. 49 refs., 24 figs.
This document provides information and presents data on the energy situation in many regions of Canada. The first part deals with the petroleum and the bitumen shales of Alberta (reserves, exploitation and production, environmental impacts), the second part discusses with the hydroelectricity choice of Quebec and the 2004 crisis. The nuclear situation of Ontario is presented in the third part (nuclear park, programs, uranium reserves, research and development on Candu reactors), while the fourth part deals with the renewable energies (wind power and biomass). The canadian situation facing the Kyoto protocol is discussed in the last part. (A.L.B.)
Isothermal transformation kinetics of austenite to acicular ferrite and allotriomorphic ferrite were measured in reheated low alloy steel weld deposits with similar weld compositions and austenite grain size but different inclusion characteristics. Accelerated kinetics of transformation to acicular ferrite were observed in weld metal containing coarser and titanium-rich inclusions. In contrast, kinetics of transformation to allotriomorphic ferrite were not influenced by inclusion characteristics, but, rather, by the austenite grain size and carbon concentration.
The results of an investigation into the behavior of adhesively bonded doubler splices of two composite material sandwich panels are presented. The splices are studied from three approaches: analytical; numerical (finite elements); and experimental. Several parameters that characterize the splice are developed to determine their influence upon joint strength. These parameters are: doubler overlap length; core stiffness; laminate bending stiffness; the size of the gap between the spliced sandwich panels; and room and elevated temperatures. Similarities and contrasts between these splices and the physically similar single and double lap joints are discussed. The results of this investigation suggest several possible approaches to improving the strength of the sandwich splices.
Defects ~10 nm in size, with number densities ~10^{10} cm^{-2}, form spontaneously beneath ion-milled, etched, or HF-dipped silicon surfaces examined in our Ti-ion getter-pumped transmission electron microscope (TEM) after exposure to air. They appear as weakly-strained non-crystalline intrusions into silicon bulk, that show up best in the TEM under conditions of strong edge or bend contrast. If ambient air exposure is <10 minutes, defect nucleation and growth can be monitored {\\em in situ}. Possible mechanisms of formation are discussed.
Four /sup 125/I labeled mono- and diamines were prepared and evaluated as potential brain-imaging agents. The diamines are analogues of the previously reported /sup 75/Se labeled diamines, which show high brain uptake and retention. All of the radioiodinated amines display high initial brain uptake in rats after intravenous injection (1.7-2.4% dose/organ). The xylylenediamines show prolonged brain retention (t1/2 approximately 18 h), which is desirable for brain imaging. In contrast, the benzylamine is rapidly cleared from brain tissue (t1/2 approximately 15 min).
Intraspinal synovial cysts were diagnosed in six patients during a 5-year period and retrospectively studied. Plain films of the lumbar spine showed degenerative changes in all patients. Lumbar myelography showed a posterior and lateral defect caused by extradural compression. Using CT without contrast enhancement established the diagnosis in five of the six patients. In four cases MRI was performed, three before and after injection of gadolinium diethyline-triamine penta-acetic acid (Gd-DTPA). Including the patient with a false-negative CT, MRI was positive in all patients. (orig.)
We study the static potential of open bosonic membranes in the 1/d approximation, where d is the space-time dimensionality. For a fixed square boundary of side length R we find, in contrast to the string potential, no critical distance below which tachyons appear. Instead, we find a correction factor to the classical potential, V/sub cl/=kR/sup 2/, which for small distances shifts the perturbative ground state energy by a positive constant. We interpret the shift as the mass gap of this quantum membrane.
we report an ultrafast synchrotron x-ray phase contrast imaging study of the primary breakup mechanism of a coaxial air-assisted water jet. We demonstrate that there exist great similarities in the phenomenology of primary breakup with that of the secondary breakup. Especially, a membrane-mediated breakup mechanism dominates the breakup process for a wide range of air speeds. This finding reveals the intrinsic connections of these two breakup regimes and has deep implications on the unified theoretical approach in treating the breakup mechanism of high speed liquid jet.
We calculate the cross section for the resonance scattering of Lyman-..cap alpha.. radiation by spinless nonrelativistic hydrogen atoms in the ground state using a two-level model. A generalization of Dirac's resonance scattering theory is used together with the exact matrix elements for the electromagnetic interaction. In contrast to the usual treatments in which only the dipole approximation for the matrix elements are taken, the shift in position of the resonance is finite and has a value of 75% of the Lamb shift of the n=1 state. Whether this latter fact is significant in renormalization calculations is left open.
RADSOLVER is a computer program which calculates the radiation energy transport in cavity type receivers having an arbitrary number of apertures through which collimated beams of solar radiation enter. In contrast to the common assumption of gray (or semi-gray) surfaces used in the modeling of radiation transport, RADSOLVER accounts for the wavelength-dependence of emission, absorption and reflection with a band model of the radiative properties. It is intended that this report serve both as an instruction manual for the use of the RADSOLVER code and a vehicle for presenting the underlying theory. Illustrative examples along with input and output are presented.
This paper describes Z-contrast scanning transmission electron microscopy used to study the connection between dopant precipitation and phase transformation in high dose In"+ and Sb"+ implanted Si. In the case of In, the observations confirm a heterogeneous nucleation model. Images of the precursor precipitates give the first measurement of the diffusion coefficient in amorphous Si, with an enhancement of 10"7 over tracer crystalline values. With Sb"+ implants enhanced homogeneous nucleation is observed. The connection between these results and the transient enhanced diffusion observed in crystallized Si is discussed.
E. coli HB101 cells transformed to tetracycline resistance with the plasmids pMB9 or pBR322 display a 10/sup 5/-10/sup 6/-fold lower plating efficiency on agar containing 440 ..mu..M CdCl/sub 2/ than nontransformed cells. When DNA is inserted into the BamH1 site of the plasmid tet gene, or when DNA spanning the BamH1 site is deleted, tetracycline resistance and cadmium hypersensitivity are both lost. In contrast, insertion of DNA into the ampicillin resistance gene does not affect cadmium hypersensitivity.
Because of limitation on neutron-incident data, it is difficult to obtain global optical model potential for neutrons. In contrast, there are some global optical model potentials for proton in detail. It is interesting to convert the proton-incident global optical potentials into neutron-incident ones. In this study we introduce (N-Z)/A dependent symmetry potential terms into the global proton-incident optical potentials, and then obtain neutron-incident ones. The neutron potentials reproduce total cross sections in an acceptable degree. However, a comparison with potentials proposed by other authors brings about a confused situation in the sign of the symmetry terms. (author).
The paper develops a new class of financial market models. These models are based on generalized telegraph processes: Markov random flows with alternating velocities and jumps occurring when the velocities are switching. While such markets may admit an arbitrage opportunity, the model under consideration is arbitrage-free and complete if directions of jumps in stock prices are in a certain correspondence with their velocity and interest rate behaviour. An analog of the Black-Scholes fundamental differential equation is derived, but, in contrast with the Black-Scholes model, this equation is hyperbolic. Explicit formulas for prices of European options are obtained using perfect and quantile hedging.
Nucleon and meson effective masses in the nonlinear relativistic mean-field theory introducing a nonlinear {omega}-{rho} and {sigma} coupling motivated by the quark-meson coupling model is explored. It is shown that, in contrast to the usual Walecka model, not only the effective nucleon mass m{sub eff,N} but also the effective {sigma},{rho} meson masses (m{sub eff{sigma}},m{sub eff,{rho}}) and the effective {omega} meson mass m{sub eff,{omega}} are nucleon density dependent. (author)
Nucleon and meson effective masses in the nonlinear relativistic mean-field theory introducing a nonlinear #omega#-#rho# and #sigma# coupling motivated by the quark-meson coupling model is explored. It is shown that, in contrast to the usual Walecka model, not only the effective nucleon mass m_e_f_f_,_N but also the effective #sigma#,#rho# meson masses (m_e_f_f_#sigma#,m_e_f_f_,_#rho#) and the effective #omega# meson mass m_e_f_f_,_#omega# are nucleon density dependent. (author)
Neutron resonance interactions with /sup 100/Mo were studied at a time-of-flight facility. The transmission of two oxide samples (97.4% /sup 100/Mo) was measured at a 78.20 m flight path and the neutron capture cross section was measured at 40.12 m. Resonance analyses yielded parameters of 124 resonances. Capture ..gamma..-ray spectra from 11 resolved resonances were measured with a Ge(Li) detector at a 10.45 m flight path. In contrast to neighboring nuclei, partial radiation widths of strong p-wave resonances are not in agreement with valence model predictions.
Measurements of low-energy (#approx#10"- "1"0 J) femtosecond laser pulse durations have been carried out on the basis of second-order autocorrelation function analysis. The scheme of non collinear second harmonic generation realized in KDP crystal has been used for increasing of the measurement contrast and accuracy. Proposed scheme can be used for measurements in wide enough ranges of laser pulse durations (from tens femto seconds to hundreds picoseconds) and energies. (authors)
A low power polychromatic beam of microwaves is used to diagnose the behavior of turbulent fluctuations in the core of the JT-60U tokamak during the evolution of the internal transport barrier. A continuous reduction in the size of turbulent structures is observed concomitant with the reduction of the density scale length during the evolution of the internal transport barrier. The density correlation length decreases to the order of the ion gyroradius, in contrast to the much longer scale lengths observed earlier in the discharge, while the density fluctuation level remain similar to the level before transport barrier formation.
The magnetization of ultrathin bcc Fe films (two and three monolayers) on MgO was measured and compared with the behavior predicted for a two-dimensional ferromagnet. The experiment indicated that no hysteresis was present in the magnetization. Instead, the magnetization at low temperature was affected by a marked field cooling effect. These observations lead to the conclusion that films of Fe on MgO of such thickness exhibit superparamagnetic behavior as if they were not entirely continuous. In contrast, films thicker than five monolayers exhibit a magnetic response close to that of bulk iron.
To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10 kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape-off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge. (authors)
The central nervous system is involved in 10-20% of cases in Lyme disease. The neurological symptoms, time course of the disease and imaging findings are multifaceted. We report two patients with cervical radiculitis. Magnetic resonance imaging revealed strong enhancement of the cervical nerve roots on contrast-enhanced T1-weighted images. These imaging patterns of borrelia-associated radiculitis have not been reported before. Knowledge of these imaging features may help to diagnose neuroborreliosis, which presents with non-specific symptoms. (orig.)
Radioactive "1"4C sucrose was found to be an ideal marker for microleakage because it did not penetrate tooth tissue, dental cement, or mounting resin. The main finding is that the adhesive cements--the glass-ionomer and polycarboxylate--are significantly more effective at preventing microleakage than are the traditional phosphate cements--silicate and zinc phosphate. The differences can be as high as two orders of magnitude. The adhesive cements provide almost perfect and reliable seals. By contrast, the nonadhesive cements are erratic sealants with most of the restorations leaking.
Attention is paid to the production mechanisms of light scalars that reveal their nature. We reveal the chiral shielding of the \\sigma(600) meson. We show that the kaon loop mechanism of the \\phi radiative decays, ratified by experiment, points to the four-quark nature of light scalars. We show also that the light scalars are produced in the two photon collisions via four-quark transitions in contrast to the classic P wave tensor q\\bar q mesons that are produced via two-quark transitions $\\gamma\\gamma\\to q\\bar q$. The history of spontaneous breaking of symmetry in quantum physics is discussed in Appendix.
This paper describes industrial aspects of combined inventory management and routing in maritime and road-based transportation, and gives a classification and comprehensive literature review of the current state of the research. The literature is contrasted with aspects of industrial applications from a constructive, but critical, viewpoint. Based on the status and trends within the field, future research is suggested with regard to both further development of the research area and industrial needs. By highlighting the industrial aspects, practitioners will hopefully see the benefit of using advanced decision support systems in complex situations related to combined inventory management and routing in their business. In addition, a classification and presentation of the research should hel...
An improved method for the synthesis of (/sup 15/N) 16-Doxyl stearate, a fatty-acid spin label, is reported. The method requires only one mole of (/sup 15/N) 2-amino-2-methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1-3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.
Peripheral primitive neuroectodermal tumors (peripheral PNETs) are rare in the abdomen. We report the imaging findings of four peripheral PNETs arising in the abdomen. Three were ill-demarcated tumors and one was a well-demarcated tumor, with extensive local invasion and lymph node metastasis in two cases, respectively. The tumors are of inhomogeneous attenuation and heterogeneous enhancement after intravenous administration of contrast materials. Although their imaging manifestations cannot distinguish them from other sarcomas, recognition of these imaging features may be helpful in suggesting the possibility of peripheral PNETs in some cases.
By characterising the microstructure, quantitative image analysis allows to draw conclusions on the mechanical properties of materials. On fine microstructures with low contrast, e.g. of hardened steels, texture analysis has to be applied for quantification. Feeding texture parameters according to Haralick into a trained neural network, a correlation between the microstructure and the hardness of the steels C45 and 100Cr6 can be achieved. (orig.)
A 1.5-year-old male Belgian Malinosis Military Working Dog presented with a 1-month history of intermittent hematuria. Diagnostic ultrasound and contrast radiography demonstrated large blood clots in the urinary bladder and a filling defect in the right renal pelvis. At surgery, clotted blood was present in the right ureter and bladder. Following right nephrectomy, the dog returned to training. One month later, elevations in urea nitrogen and creatinine were noted. Hematuria recurred at 3 months and the dog was found dead in its kennel. Necropsy showed a blood-filled left renal pelvis and ureter. PMID:1454185
Magnetic resonance (MR) imaging and histopathology were used to diagnose an articular process synovial myxoma in a dog. On MR images, the tumor was characterized by distortion of the left L1-L2 articular process, widening of the articular process joint, and the presence of a mass contiguous with the synovium of the articular process that displaced the spinal cord. The tumor was T2-hyperintense, T1-hypointense, relative to muscle, and had mild contrast enhancement. The MR features of articular process synovial myxoma may be distinct from other diseases of the articular process joint.
This paper reports on high resolution electron microscopy used to investigate the effect of electron irradiation induced oxygen loss on the states of partial order in YBa_2Cu_3O_z. Contrast effects visible in the [001] zone image as a result of the degree of the out-of-plane correlation of these ordered states are investigated. Using statistical simulations to aid in the analysis of the HREM images, an interpretation based on a kinetically limited evolution of the variation of long range [001] ordering is proposed.
Weakly absorbing materials, such as biological, soft tissues, can be imaged by generating contrast due to the phase shift of X-rays. In the past decade, several methods for X-ray phase imaging were proposed and demonstrated. The performance of X-ray phase imaging is attractive in the field of medical imaging technology, and its development for practical use is expected. Many methods, however, have been developed under the assumption of the use of synchrotron radiation, which is an obstacle to practical use. The method based on Talbot (-Lau) interferometry enables us to use a compact X-ray source, and its development is expected as a breakthrough for medical applications. (author)
The use of Gadolinium-DTPA as a paramagnetic contrast agent in MRI with adults and juveniles concerning brain and spinal cord pathology is well proven since years. In the FRG it is only introduced for children over two years of age. Therefore this report deales with the experience in four infants and small children under the age of two. They all were suffering from neurological tumors and got additional diagnostic information in three cases. Clinical side-effects like urticaria, vomiting or convulsions had not been observed nor had pathologic changes of the biochemical parameters been noticed. (orig./GDG).
Most papers appearing in the surgical literature dealing with wound ballistics concern themselves with wound management in the civilian setting. The pathophysiology of modern war wounds is contrasted with ballistic wounds commonly encountered in peacetime, but it should be noted that even in peacetime the modern terrorist may have access to sophisticated military weaponry, and that patients injured by them may fall within the catchment area of any civilian hospital. Management problems associated with both wound types are highlighted; areas of controversy are discussed. The orthodox military surgical approach to ballistic wounds is expounded and defended. PMID:1996857
Chest radiograms obtained by using Fuji Computed Radiography (FCR) system were compared to conventional film/screen radiograms. The FCR images showed better image quality in diagnostic information than the conventional chest images. In FCR, the radiation exposure to patient for chest examination could be reduced up to one tenths of conventional chest examination. The main advantages or FCR were considered to depend on the contrast processing and frequency processing properties. The use of FCR in clinical work may improve both diagnostic quality and radiation exposure.
In this paper, we present FASE (Faster Asynchronous Systems Evaluation), a tool for evaluating the worst-case efficiency of asynchronous systems. The tool is based on some well-established results in the setting of a timed process algebra (PAFAS: a Process Algebra for Faster Asynchronous Systems). To show the applicability of FASE to concrete meaningful examples, we consider three implementations of a bounded buffer and use FASE to automatically evaluate their worst-case efficiency. We finally contrast our results with previous ones where the efficiency of the same implementations has already been considered.
We demonstrated that the intensity levels and lifetimes of two-photon autofluorescences (2PAF) in human liver tissues can be exploited to diagnose hepatocellular carcinoma (HCC). Excited by an infrared femtosecond laser, we suppressed the two-photon autofluorescences of most endogenous fluorophores and made red autofluorescences more specific to particular molecules in the cryo-sectioned human livers. Using such fluorescence contrast, we found HCC tissues have reduced levels of 2PAF and longer fluorescence lifetime.
A previously studied theory of gravitation in flat space-time is applied to homogeneous and isotropic cosmological models. There exist two different classes of models without singularities: (i) ever-expanding models, (ii) oscillating models. The first class contains models with hot big bang. For these models there exist at the beginning of the universe-in contrast to Einstein's theory-very high but finite densities of matter and radiation with a big bang of very short duration. After short time these models pass into the homogeneous and isotropic models of Einstein's theory with spatial curvature equal to zero and cosmological constant ALPHA >= O.
Twenty rheumatoid arthritis (RA) patients with involvement of the cranio-cervical junction (CCJ) were given CT scan. In most cases the myelo-CT technique with the lumbar injection of small quantities of non-ionic contrast medium was adopted; CT easily diagnosed the horizontal and vertical dislocations on the CCJ, the bone strcture lesions and the inflammatory masses. A high frequency of medullary compressions was also found in these patients. Myelo-CT appears to be the technique of choice for the precise definition of the various factors responsible for the neurological complications found in RA of the CCJ.
An alkali-like ion interaction with inner electrons of an alkali-like ion leads to a significant increase in the photoionization cross section of the outer s electron. This occurs not only for ground-state ions with one s electron in the outer shell, but also when the outer s electron is in an excited state. The reason for this amplification, in addition to coherent enhancement in summing of the correlation amplitudes, is that the zero in the direct amplitude occurs below threshold. This leads to a constructive interference with the correlation amplitude above the photoionization threshold, in contrast to a destructive interference in the case of a neutral atom with the same electronic configuration, for which the zero occurs above threshold. Results of this research were published.
We studied 129 AIDS patients with suspected or proved intracranial manifestations of the disease. The purpose of this study was to compare the diagnostic sensitivity of unenhanced and contrast enhanced CT and unenhanced T{sub 2}-weighted MR. Thus, in 20% of our patients MR but not CT was diagnostic. In another 20% MR provided additional diagnostic information. In conclusion, MR is recommended as the imaging modality of choice in AIDS patients with non-conclusive cranial CT. (orig./GDG).
This paper develops a model of nonlinear pricing with competition. The novel element is that each consumer's willingness to pay for quality is private information and is allowed to differ across brands. The consumer's preferences are represented by a multidimensional type containing the marginal value of quality for different products. Buyers with high willingness to pay for quality also display strong preferences for particular brands, and require higher discounts in order to switch away from their favorite product. Therefore, competition is fiercer for buyers with lower tastes for quality, and hence more elastic demands. This is in sharp contrast to earlier models in which competition is fiercer for higher-taste, more valuable buyers. In equilibrium, firms either compete intensively for ...
Marketing-led enterprise change management initiated by a major UK contractor is explored in this paper as a contrast to procurement-led changes to projects driven by clients. Procurement-led initiatives try to induce changes to behaviour through market governance. Relationship marketing and management proactively change organizational behaviour, the enterprise taking responsibility for its own destiny. Investment and resource allocation, and organizational behaviour have posed constraints, particularly concerning service continuity in construction. Overcoming these constraints offers opportunities for delivering service improvements and adding value for clients and yielding further increases in repeat business and increasing profitability. Relationship marketing is the conceptual starting...
The crossed electron-ion beams technique was used to measure absolute cross sections for single ionization of Ar"2"+, Kr"2"+ and Xe"2"+ ions at electron energies ranging from threshold to 2000 eV. In contrast to some previous measurements, the metastable contents of the ion beams were small even in the case of Xe"2"+. All measured cross section curves show significant contributions from excitation-autoionization and possibly direct ionization of inner-shell electrons. There is evidence for resonance-excitation-double-autoionization in the case of Xe"2"+. (author).
A new generation of quasimonochromatic high-flux X-ray sources, based on the X-ray radiation produced through Compton scattering between an electron beam and a laser beam, is under development. One of the possible applications of this source is inline phase contrast mammography, based on the observation of the edge-enhancement effect that can be observed at the border of structures inside the breast in images produced using a partially or totally coherent X-ray beam. In this work we present the results of a set of simulations of inline phase contrast mammography using typical inverse Compton scattering sources parameters. The simulated sample was a tumour-like mass having spherical shape, diameter between 200 {mu}m and 5 mm, placed inside a breast-like matrix, 4 cm thick, and a standard composition of 50% glandular tissue and 50% adipose tissue. We discuss the minimum requirements for mammography using inverse Compton scattering sources and we ...
Objective: To investigate the value ofMSCT in observing the direct findings of hilar cholangiocarcinoma1Methods Multislice helical CT studies were performed on the upper abdomen in 19 consecutive patientswith painless jaundice1 Precontrast and dynamic contrast enhanced (25 s phase and 60 s phase) scanswere conducted, and 3D imageswere reconstructed using enhanced raw data in 15 cases1 The direct CT findings of hilar cholangiocarcinoma were studied by three radiologists respectively in a 32scale strategy1 The morphological features and extension of bile duct involvement by hilar cholangiocarcinoma were analyzed1 All the 19 caseswere pathologically p roved as hilar cholangiocarcinoma by surgery (15 cases) and ERCP ( 4 cases) 1 Results The direct findings and extension of hilar cholangiocarcinoma could be demonstrated in 14 out of 15 3D reconstruction images, 8 out of 19 in 25 s phase, and 7 out of 19 in 60 s phase of contrast enhancement scans, ...
Aim of this retrospective study was to assess the capability of contrast-enhanced helical computerised tomography (CT) in sigmoid diverticulitis, especially relative to selection of the appropriate treatment. The findings of 41 patients were reviewed from 1998 to 1999 June. Contrast-enhanced helical CT is the imaging modality of choice in assessing mild or severe acute diverticulitis because it provides useful information for appropriate treatment planning in the emergency setting. This technique is most useful in questionable cases and in patients with suspected severe diverticulitis where a choice must be made between different treatment options. [Italian] Scopo di questo studio retrospettivo e' illustrare i molteplici aspetti radiologici della flogosi diverticolare sigmoidea con tomografia computerizzata (TC) spirale, con specifico riguardo alle implicazioni terapeutiche che scaturiscono dall'analisi e dal confronto dei ...
Active contrast material extravasation can be recognized with conventional CT scanners, though it has been considered a rare finding. Helical CT seems to increase the detection rate and especially to boost the radiologist's confidence in this diagnosis. Though active bleeding is defined in severely-injured subjects requiring urgent intervention and may be associated with findings of hypovolaemic shock, it should not be considered itself as a negative prognostic factor. Contrast extravasation is due to ongoing hemorrhage and its detection is critical for urged treatment. Accurate anatomical location permits to choose surgical management or transcatheter embolization and thus decreases time consumption for precis e bleeding site identification. [Italian] Lo stravaso attivo del mdc e' rilevabile anche con appropriate apparecchiature TC tradizionali, sebbene sia stato considerato raro. La TC sprirale sembra aumentare la frequanza ...
Sixty-three subjects, aged 6 months to 16 years, who were enrolled in a prospective, fully blinded, randomized parallel-group phase III clinical trial, received 0.1 mmol/kg doses of either Gd-BOPTA (n=29) or Gd-DTPA (n=34). The MR images were acquired before and within 10 min of contrast agent injection. The primary objective was to compare the difference from pre-dose to post-dose lesion visualization between Gd-BOPTA and Gd-DTPA. Lesion visualization was determined as the sum of individual scores for three criteria of lesion morphological characteristics (lesion border delineation, internal morphology, and contrast enhancement), each assessed qualitatively using 4-point scales. Quantitative evaluation compared changes in lesion-to-background (LBR) and contrast-to-noise (CNR) ratios and per cent enhancement. Monitoring for adverse events and evaluation of vital signs and laboratory values was performed. Pre-dose to ...
The aims of investigation were to follow the Sr transport in the food chain from the flora to the fauna and humans, and its dependence on the geological origin og the plant site, industrial emissions, the age and site of plants, the part of plant used for nutrition and the strontium content in the drinking water, to determine the Sr intake of humans with the help of the duplicate method, and to estimate the apparent absorption rate and balance of strontium depending on of the form of diet (mixed or ovolactovegetarian), sex, season, age, region (geological origin of the living space) and method of intake measurement (duplicate or basket method). Strontium, an ultra trace element widespread in the earth's crust, is not essential and only mildly toxic for plants, animals and man according to current knowledge. The biological essentiality of Sr has not been investigated yet. Amoeba species living in sea water use Sr for the formation of their skeleton instead of Ca. ...
In 2003, Vehicle Emissions Team of the Clean Air Strategic Alliance (CASA) decided to explore ways to reduce vehicle emissions such as particulate matter, nitrogen oxides, carbon monoxide, and hydrocarbons from diesel engines. One of the options for reducing emissions from diesel engines, a diesel particulate filter (DPF), is the subject of a demonstration project to test the effectiveness of the Johnson Matthey diesel particulate filter called Continuously Regenerating Technology (CRT) under cold weather conditions. The project involved filter testing between January 2003 and January 2004 on two diesel buses in Edmonton Transit System's (ETS) fleet. Vehicle exhaust emissions were tested for total hydrocarbons, nitrogen oxides, carbon monoxide, carbon dioxide, and particulate matter. The objectives of the project were to: prove the effectiveness of DPF under cold weather conditions in Alberta; provide an opportunity for hands-on installation experience and use of CRT ...
The integrated-gasification combined-cycle (IGCC) process is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of {open_quotes}as-generated{close_quotes} slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for {open_quotes}as-generated{close_quotes} slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more promising approach would be ...
Classical beam line ion implantation is limited to low energies and cannot achieve P+/N junctions requested for <45nm ITRS node. RTA (rapid thermal annealing) needs to be improved for dopants activation and damage reductions. Spike annealing process also induces a large diffusion mainly due to TED (transient enhanced diffusion). Compared to conventional beam line ion implantation limited to a minimum energy implantation of 200eV, plasma immersion ion implantation (PIII) is an emerging technique to get ultimate shallow profiles (as-implanted) due to no lower limitation of energy and high dose rate. On the another hand, laser thermal processing (LTP) allows to obtain very shallow junction with no TED, abrupt profile and activated depth control. In this paper, we show the implementation of the BF_3 PIII associated with the LTP. Ions from BF_3"+ plasma have been implanted in 200mm n-type silicon wafers with energies from 100eV to 1keV and doses from 3E14 to 5E15at/cm"2 using PULSION"(R) ...
An approach to the ductile fracture of ultra high strength steels has been evaluated. According to this approach the critical crack tip opening, delta/sub IC/, will scale with X/sub 0/(R/sub V//R/sub I/vertical bar/sub R//sub 0/. X/sub 0/ is an average inclusion spacing and (R/sub V/R/sub I/)vertical bar/sub R//sub 0/ is the void radius divided by the radius of the inclusion nucleating the void evaluated at the average inclusion size. AF1410 was selected to test this approach because it has exceptionally high fracture toughness on aging at 510/sup 0/C and because its toughness varies markedly with aging temperature. The results from this and earlier work showed a linear relationship exists between delta/sub IC/ and X/sub 0/(R/sub V//R/sub I/)vertical bar /sub R//sub 0/ for values of delta/sub IC/ ranging from about 8 ..mu..m to 60 ..mu..m. The values of (R/sub V//R/sub I/)vertical bar /sub R//sub 0/ for AF1410 aged at 425/sup 0/C and 510/sup 0/C differed by a ...
We have used polished stainless steel as a mirror substrate to provide focusing of soft x-rays in grazing incidence reflection. The substrate is bent to an elliptical shape with large curvature and high stresses in the substrate require a strong elastic material. Conventional material choices of silicon or of glass will not withstand the stress required. The use of steel allows the substrates to be polished and installed flat, using screws in tapped holes. The ultra-high-vacuum bender mechanism is motorized and computer controlled. These mirrors are used to deliver focused beams of soft x-rays onto the surface of a sample for experiments at the Advanced Light Source (ALS). They provide an illumination field that can be as small as the mirror demagnification allows, for localized study, and can be enlarged, under computer control,for survey measurements over areas of the surface up to several millimeters. The critical issue of the quality of the steel surface, ...
A set of advanced models implemented into the simulator Sentaurus Process was applied to simulate ultra shallow junction formation by flash lamp annealing (FLA). The full path transient enhanced diffusion model includes equations for small interstitial clusters (I_2, I_3, I_4), #left brace#3 1 1#right brace# defects and dislocation loops. A dopant-point defect clustering model is used for dopant activation simulation. Several cluster types are considered: B_2, B_2I, B_2I_2, B_3I, B_3I_2, B_3I_3 for boron and As_2, As_2V, As_3, As_3V, As_4, As_4V for arsenic. Different point defect and dopant-point defect pair charge states are taken into account to obtain accurate results in the high doping level region. The flux expressions in the three-phase segregation model include a dependence on the doping level and point defect supersaturation. The FLA process was performed at various peak temperatures in a Mattson Millios"T"M fRTP"T"M system. The measured wafer temperature ...
The Eiric Raude offshore drilling rig is a powerful machine that is suitable for drilling in harsh environments in ultra deep water. It has a total drilling depth of 8,200 to 10,000 metres and an operational displacement of 53,400 mt. The rig complies with the regulatory regimes of Norway, the United Kingdom and Canada. The Eiric Raude has drilled 5 deepwater wells offshore eastern Canada, 1 well offshore Cuba, 1 well west of Shetland, and 3 offshore Norway. The environmental criteria for extreme weather conditions consider wave, current and wind forces. The general operational guidelines were discussed along with key areas for prevention of environmental impact, including emissions from well testing, air emissions from diesel engines, cooling water, bunkering operations, discharges from drilling, accidental discharges, drain water, and domestic sewage. It was noted that the zero discharge philosophy is the basis for all activities. The original design was meant to ...
A bottom-up approach is used here to combine carbon nanotubes synthesized by CVD and organically capped platinum nanoparticles electrocatalyst exhibiting a direct electrochemical activity towards oxygen reduction. Both nano-objects are handled in liquid suspension and are associated together in a controlled way. The nanocomposite liquid dispersions can be precisely controlled in terms of platinum nanoparticles to carbon nanotubes weight ratios (NP/NT) which correspond to different coverages of nanotubes by nanoparticles. Electrodes with low to ultra-low platinum loadings can then be prepared on porous fuel cell carbon supports by filtration. The direct electrochemical activity towards aqueous oxygen reduction reaction (ORR) of electrodes with platinum loadings ranging from about 1 to 60 {mu}g/cm{sup 2} is reported without any activation step in order to keep the features of the nanoparticles intact. Before that, we studied the responses obtained when impregnating ...
The processes which are currently studied in the fabrication of B-doped ultra shallow junctions (USJ) usually involve a preamorphization step to reduce B channelling effect during implantation and to improve B electrical activation. At this stage a high amount of Si interstitial atoms (Is), which dramatically increases the B diffusivity, is introduced. The introduction of voids in Si is a promising tool to control B transient enhanced diffusion (TED), because of their ability to capture Is. In this work the efficiency of a cavity band to reduce B TED is checked in silicon interstitial supersaturation conditions, obtained by high dose Si implantation. He is implanted either at 10 keV or at 50 keV with a fluence of 5 x 10"1"6 cm"-"2. Conventional techniques to introduce and activate the B (conventional ion implantation and rapid thermal annealing (RTA)) are applied in order to have a better control of the technological process to focus on the benefit of the cavity ...
Due to the increasingly stricter regulations for deep reduction of fuel sulfur content, development of new deep desulfurization processes for liquid transport fuels has become one of the major challenges to the refining industry and to the production of hydrocarbon fuels for fuel cell applications. The sulfur compounds in the current transport fuels corresponding to the S level of 350-500 ppm account for only about 0.12-0.25 wt % of the fuel. The conventional hydrotreating approaches will need to increase catalyst bed volume at high-temperature and high-pressure conditions for treating 100 % of the whole fuel in order to convert the fuel mass of less than 0.25 wt %. In the present study, we are exploring a novel adsorption process for desulfurization at low temperatures, which can effectively reduce the sulfur content in gasoline, jet fuel and diesel fuel at low investment and operating cost to meet the needs for ultra-clean transportation fuels and for fuel cell ...
Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists' capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically, awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted light-emitting diode (LED), tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the extended illumination periods often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 g capable of wirelessly receiving power using a ...
Decaborane (B_1_0H_1_4) cluster ions were implanted into n-Si(100) substrates to fabricate shallow p"+/n junctions. Implant energies of 2 keV, 5 keV, and 20 keV, equivalent to implant energies of the monomer boron ion of 174 eV, 435 eV, and 1.74 keV, respectively, were used at dosages of 1 X 10"1"2 /cm"2 and 1 X 10"1"3 /cm"2. The implanted samples were then subjected to activation annealing at 800 .deg. C, 900 .deg. C, and 1000 .deg. C for 10 s. By using secondary ion mass spectrometry (SIMS) depth profiles, we determined that the depth of the shallow junction (D_s) at a dosage of 1 X 10"1"3 /cm"2 was in the range 12 nm - 45 nm after annealing at 1000 .deg. C. D_s and transient enhanced diffusion (TED) were greatly reduced at implant energies lower than 5 keV, but thermal diffusion (TD) smoothly decreased. In particular, TED was suppressed in the p"+/n junction implanted at 2 keV and a dosage of 1 X 10"1"3 /cm"2, and the formation of only a 5.6-nm ultra-shallow ...