This paper describes new test methodologies to obtain data used to evaluate the ultimate seismic strength of Nuclear Power Plant (NPP) equipment related to nuclear safety. The paper first reviews existing equipment seismic test data from the viewpoint of the evaluation of their ultimate seismic strength and/or seismic design margins, and extracts the issues in the existing data with regard to their applicability to the evaluation. Then, the paper proposes new test methodologies for the equipment to evaluate their ultimate seismic strength. The test methodology of the equipment employs a vibration amplification system to a shaking table and enhances its applicable maximum acceleration up to 6g. The test methodology herein is cost effective for obtaining test data that is indispensable for evaluating proper seismic margins of NPPs. (author)
Experiments contributing to the understanding of the aerodynamics of airfoils operating in the vertical axis wind turbine (VAWT) environment are described. These experiments are ultimately intended to reduce VAWT cost of energy and increase system reliability. They include chordwise pressure surveys, circumferential blade acceleration surveys, effects of blade camber, pitch and offset, blade blowing, and use of sections designed specifically for VAWT application.
The possible parameters of a photon linear collider at its ultimate luminosity, based on the VLEPP physics and technology V.E. Balakin et al., Proc. 6th Nat. Conf. on Accelerators, Dubna, 1978; V.E. Balakin, Proc. 4th Int. Workshop on Next Generation Linear Colliders, Garmisch, 1992, are presented. At a photon energy of 100x100 GeV the maximum achievable luminosity is about 1x10{sup 36} cm{sup -2} s{sup -1}. Beam parameters, luminosity characteristics, and ways to reduce the background are considered as well. ((orig.)).
Ultimate compressive strength in the longitudinal direction. (3. Ultimate tensile strength in the transverse direction. U'. Ultimate compressive strength in ...
The most important aim of the title program is to investigate the possibility to convert long-lived actinides and mobile fission products in short-lived and stable isotopes by means of nuclear transmutation and recycling. First, an overview is given of the present situation regarding fission material waste, the origin of such waste in light water reactors and the options for interim and ultimate storage. Next, attention is paid to the aim of the the RAS program, the working method and the results so far of national and international research on the transmutation of actinides and fission products. Speculative expectations for the future are briefly outlined. The report also contains four appendices with technical aspects of the title subject: the RAS program of ECN, chemical aspects of reprocessing fission material, transmutation in fission reactors and in accelerators. 12 figs., 7 tabs., 4 appendices, 57 refs.
A working visit was made to the National Laboratory for High Energy Physics, Tsukuba, Japan, during the time periods May 16, 1988--June 15, 1988 for the purposes of further evaluation of the high intensity plasma sputter negative ion source and to test the response of the University of Tsukuba 13-MV tandem accelerator to mA intensity level pulsed mode heavy negative ion beams. During the visit, the traveler worked in collaboration with Japanese scientists in installing and testing of the source on the University of Tsukuba tandem electrostatic accelerator injector. During the course of preliminary testing of the ion source and prior to actual injection into the accelerator, sparking began in one or more tube sections, which ultimately led to the decision to replace the damaged tube sections. This problem led to postponement of the scheduled tandem accelerator tests. The traveler ...
The Earth`s troposphere and hydrosphere contain abundant naturally generated dust. The ultimate source materials from which the terrestrially produced dust is generated are the various rock types exposed at the Earth`s surface. Natural dust is a composite of (1) lithic, primary mineral grains; (2) mineral grains formed by secondary chemical reactions; (3) volcanic ash and dust; (4) salts from sea sprays; (5) extra-terrestrial dust; and (6) biologic materials. In this paper the various pathways to the natural generation of dust (via the hydrologic cycle) will be discussed, and two geologically well-known natural dust sources will be described, paying particular attention to quantitative measurements of the dusts from these areas. General dust studies that provide data on possibly global background levels will be presented as well.. A few general aspects of the mineralogical characterization of dust particles and a discussion of some of the ...
As with science, so with security--in both arenas, the extraordinary sensitivity of cryogenic sensors enables high-confidence detection and high-precision measurement even of the faintest signals. Science applications are more mature, but several national and international security applications have been identified where cryogenic detectors have high potential payoff. International safeguards and nuclear forensics are areas needing new technology and methods to boost speed, sensitivity, precision and accuracy. Successfully applied, improved nuclear materials analysis will help constrain nuclear materials diversion pathways and contribute to treaty verification. Cryogenic microcalorimeter detectors for X-ray, gamma-ray, neutron, and alpha-particle spectrometry are under development with these aims in mind. In each case the unsurpassed energy resolution of microcalorimeters reveals previously invisible spectral features of nuclear materials. Preliminary results of ...
This paper deals with two common problems and then considers major aspects of chemistry in the atmospheres of Mars and Venus. (1) The atmospheres of the terrestrial planets have similar origins but different evolutionary pathways because of the different masses and distances to the Sun. Venus lost its water by hydrodynamic escape, Earth lost CO"2 that formed carbonates and is strongly affected by life, Mars lost water in the reaction with iron and then most of the atmosphere by the intense meteorite impacts. (2) In spite of the higher solar radiation on Venus, its thermospheric temperatures are similar to those on Mars because of the greater gravity acceleration and the higher production of O by photolysis of CO"2. O stimulates cooling by the emission at 15@mm in the collisions with CO"2. ...
Abstract Despite the fact that oxidation is the second most frequent degradation pathway for pharmaceuticals, means of evaluating the oxidative stability of pharmaceutical solids, especially effective stress testing, are still lacking. This paper describes a novel experimental method for peroxide-mediated oxidative stress testing on pharmaceutical solids. The method utilizes urea-hydrogen peroxide, a molecular complex that undergoes solid-state decomposition and releases hydrogen peroxide vapor at elevated temperatures (e.g., 30C), as a source of peroxide. The experimental setting for this method is simple, convenient, and can be operated routinely in most laboratories. The fundamental parameter of the system, that is, hydrogen peroxide vapor pressure, was determined using a modified spect...
Ultimate compressive strength and failure modes were studied using 24- ... to 81 % of the average ultimate compressive strength (UCS). Figure 1 (a) is the failure ...
... In fact, for dynamic loading, the ultimate compressive strength can be more than doubled (Bischoff and Perry 1991), whereas the ultimate uniaxial ...
A shock wave appears when the release of accumulated energy is instantaneous. For instance, it accompanies gunpowder explosion, electric discharge, laser beam convergence, collision of high-speed objects, release of high-pressure gas, and supersonic flight. The shock wave research center of Institute of Fluid Science, Tohoku University, is engaged in researches to elucidate the basics of various shock wave phenomena and to apply the fruit to engineering, science, and medicine. In this report, some examples of recent application studies at the center are described, and the trend of shock wave researches in the future is introduced. The ultimate state of the stagnation point of a nozzle flow simulating a reentry into the atmosphere is produced by shock wave compression in a free piston shock tube which is a ground-borne experimental apparatus. Los Alamos National Laboratory, U.S., succeeded in generating metallic hydrogen of a crystalline structure by subjecting ...
Primordial black holes are unique probes of cosmology, general relativity, quantum gravity and non standard particle physics. They can be considered as the ultimate particle accelerator in their last (explosive) moments since they are supposed to reach, very briefly, the Planck temperature. Upper limits on the primordial black hole number density of mass $M_{\\star} = 5 10^{14}$ g, the Hawking mass (born in the big-bang terminating their life presently), is determined comparing their predicted cumulative $\\gamma$-ray emission, galaxy-wise, to the one observed by the EGRET satellite, once corrected for non thermal $\\gamma$-ray background emission induced by cosmic ray protons and electrons interacting with light and matter in the Milky Way. A model with free gas emissivities is used to map the Galaxy in the 100 MeV photon range, where the peak of the primordial black hole emission is expected. The best gas emissivities and additional model ...
The insulating oil used in a transformer is a critical component, as its service life is typically 20 years with possibly little or no maintenance. Partial discharges (PD), thermal overloads and static discharges continually subject the oil to chemical deterioration during its operating life. To ensure equipment reliability during service, it is important that the initial quality of the new insulating oil should meet the required acceptance specifications and preferably be pre-tested before use. Accelerated aging tests have been devised to determine the life expectancy of oil in service by using forced air or oxygen flow into the oil, the presence of a copper catalyst, and at elevated temperatures. The more important standards relating to transformer application are discussed and highlights of the more important aspects of the oxidation chemistry of hydrocarbons are included. The ultimate aim of the project is the formulation of better standard ...
Beams may be viewed as directed and focussed flow of energy and information, carried by particles and electromagnetic radiation fields (ie, photons). Often, they interact with each other (eg, in high energy colliders) or with other forms of matter (eg, in fixed targets, sychrotron radiation, neutron scattering, laser chemistry/physics, medical therapy, etc.). The whole art and science of beams revolve around the fundamental quest for, and ultimate implementation of, mechanisms of production, storage, control and observation of beams -- always directed towards studies of the basic structures and processes of the natural world and various practical applications. Tremendous progress has been made in all aspects of beam physics and technology in the last decades -- nonlinear dynamics, superconducting magnets and rf cavities, beam instrumentation and control, novel concepts and collider praradigms, to name a few. We illustrate this progress with a few examples and ...
... and testing of unidirectional composites, there are serious doubts about the possibility of obtaining a true ultimate compressive strength for this kind ...
The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a ...
Because every cell within the body has the same genetic information, a significant problem in biology is to understand how cells within a tissue express genes selectively. A sophisticated network of physical and biochemical signals converge in a highly orchestrated manner to bring about the exquisite regulation that governs gene expression in diverse tissues. Thus, the ultimate decision of a cell to proliferate, express tissue-specific genes, or apoptose must be a coordinated response to its adhesive, growth factor, and hormonal milieu. The unifying hypothesis examined in this overview is that the unit of function in higher organisms is neither the genome nor the cell alone but the complex, three-dimensional tissue. This is because there are bidirectional connections between the components of the cellular microenvironment (growth factors, hormones, and extracellular matrix) and the nucl2048 These connections are made via membrane-bound receptors and transmitted to ...
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 ...
This Remedial Investigation (RI) Work Plan specifically addresses Chestnut Ridge Operable Unit 1, (OU1) which consists of the Chestnut Ridge Security Pits (CRSP). The CRSP are located {approximately}800 ft southeast of the central portion of the Y-12 Plant atop Chestnut Ridge, which is bounded to the northwest by Bear Creek Valley and to the southeast by Bethel Valley. Operated from 1973 to 1988, the CRSP consisted of a series of trenches used for the disposal of classified hazardous and nonhazardous waste materials. Disposal of hazardous waste materials was discontinued in December 1984, while nonhazardous waste disposal ended on November 8, 1988. An RI is being conducted at this site in response to CERCLA regulations. The overall objectives of the RI are to collect data necessary to evaluate the nature and extent of contaminants of concern (COC), support an ecological risk assessment (ERA) and a human health risk assessment (HHRA), support the evaluation of remedial alternatives, and ...
SummaryThe Hippo tumor-suppressor pathway controls tissue growth in Drosophila and mammals by regulating cell proliferation and apoptosis. The Hippo pathway includes...Full Text Available
While autophagy has been shown to act as an anti-viral defense, the Picornaviridae avoid and, in many cases, subvert this pathway to promote their own replication. Evidence indicates...Full Text Available
The importance of cancer metabolism has been appreciated for many years, but the intricacies of how metabolic pathways interconnect with oncogenic signaling are not fully understood. With a clear understanding...Full Text Available
Ultimate Compressive Strength of Short Sheet-Stringer Panels With Special. Reference to the Influence of the Riveted Connection Between Sheet and. Stringer ...
... Problems investigated in various basic hollowness ratios include ultimate compressive strength, fatigue properties, buckling characteristics, and ...
Four-enzyme section of the shikimate pathway (Aro B, D, E, and K) of Streptococcus pneumoniae has been studied. Kinetic properties of the individual enzymes and three- and four-enzyme linked reactions have been characterized in vitro. On the basis of the data measured in spectrophotometric and LC-MS experiments, kinetic mechanisms of the enzymes have been suggested and all kinetic parameters have been identified. Kinetic models for these three- and four-enzyme sections of the shikimate pathway have been constructed and validated. The model of the four-enzyme section of shikimate pathway has been employed to design an inhibition-sensitive reconstituted pathway for a high-throughput screening effort on the shikimate pathway. It was demonstrated that using the model it was possible to optimize this reconstituted pathway in such a way to provide equal sensitivity of ...
The main physical processes allowing negative ion production by surface sputtering for further acceleration in tandem acceleration are briefly reviewed. The sputtering yield and the probability of negative ion ejection are discussed. The properties of negative ion beams for an efficient acceleration in tandem accelerators are also discussed, with an emphasis on space charge problems. The main features and performances of the heavy negative ion injector of the Bucharest tandem accelerator are given.
Future insertion quadrupoles with large apertures and high gradients will be required for the Phase II luminosity upgrade (10{sup 35} cm{sup -2}s{sup -1}) of the Large Hadron Collider (LHC). Although improved designs, based on NbTi, are being considered as an intermediate step for the Phase I upgrade, the Nb{sub 3}Sn conductor is presently the best option that meets the ultimate performance goals for both operating field and temperature margin. As part of the development of Nb{sub 3}Sn magnet technology, the LHC Accelerator Research Program (LARP) developed and tested several 1-meter long, 90-mm aperture Nb{sub 3}Sn quadrupoles. The first two series of magnet used OST MJR 54/61 (TQ01 series) and OST RRP 54/61 (TQ02 series) strands. The third series (TQ03) used OST RRP 108/127 conductor. The larger number of sub-elements and the consequent reduction of the effective filament size, together with an increased fraction of copper and a lower Jc were ...
Pipe whip restraints are used in nuclear power plants in order to limit the consequences of ruptured pipe whip effects and are thus an important part of the plant safety concept. The design of these devices is based on the choice of adequate construction and computational analysis supported by experimental investigation. Pipe whip restraints should, by means of deforming components, be able to absorb the energy of a ruptured pipe accelerated by the fluid reaction force. Since the elastic deformation of the restraint material is not sufficient for this purpose, or would result in excessive anchor loads, pipe whip restraints must generally be designed to work in the plastic range. Two types of restraints are presented in this paper, including the description of their mode of operation, design and computation. A comparison and critical evaluation of the calculation methods presently available are also given. The range of methods covers those developed for very simple ...
The worldwide oil shale resources are extremely large. As an example, the calculated recoverable oil from just the Green River Formation in the tri-state area of Colorado-Utah-Wyoming is as large as the estimated ultimate total conventional oil production from the entire world. In addition there are significant resources in other parts of the USA and in other countries. Despite the great potential, the peace of western oil shale development took a general downturn in 1982 because of a combination of factors led by an uncertainty concerning short to intermediate term pricing for crude oil, a lesser demand for petroleum products, and increased projected costs for development. An example is Exxon's announcement that the Exxon/TOSCO multi-billion dollar project would be discontinued and most of its support equipment sold. In the eastern part of the country, Paraho decided not to move its project to Kentucky unless additional financial support could be ...
Breakdowns occurring in rf accelerating structures will limit the ultimate performance of future linear colliders such as the Compact Linear Collider (CLIC). Because of the similarity of many aspects of dc and rf breakdown, a dc breakdown study is underway at CERN to better understand the vacuum breakdown mechanism in a simple setup. Measurements of the field enhancement factor ? show that the local breakdown field is constant and depends only on the electrode material. With copper electrodes, the local breakdown field is around 10.8GV/m, independent of the gap distance. The ? value characterizes the electrode surface state, and the next macroscopic breakdown field can be well predicted. In breakdown rate experiments, where a constant field is applied to the electrodes, clusters of consecutive breakdowns alternate with quiet periods. The occurrence and lengths of these clusters and quiet periods depend on the evolution of ?. The application of ...
... the high current induction linear accelerator of the nanosecond range, meant to be used as injector in the collective ion accelerator, are presented. ...
If you missed the ARTE programme entitled "L'Ultime Particule" broadcast in February, you have another chance to catch it in CERN's Main Auditorium on 13 March. "L'Ultime Particule" is a documentary by the French director Michel Andrieu that seeks to explain particle physics through a contemplative quest for the research physicists of matter of today and yesteryear. Invariably kitted out in a red parka and a soft hat, the programme's investigator scours the planet and the archives in search of the research physicists who are stalking the ultimate particle, the Higgs boson, in their quest to understand the structure of matter. Naturally enough, CERN is an important stage of his journey where Michel Andrieu and his team spent several days last year. Both from the physics and metaphysical points of view, "L'Ultime Particule" is worth seeing. The film's director, Michel Andrieu, will introduce his ...
Summary: The KEGG PATHWAY database provides a widely used service for metabolic and nonmetabolic pathways. It contains manually drawn pathway maps with information about the genes, reactions and relations contained therein. To store these pathways, KEGG uses KGML, a proprietary XML-format. Parsers and translators are needed to process the pathway maps for usage in other applications and algorithms. We have developed KEGGtranslator, an easy-to-use stand-alone application that can visualize and convert KGML formatted XML-files into multiple output formats. Unlike other translators, KEGGtranslator supports a plethora of output formats, is able to augment the information in translated documents (e.g. MIRIAM annotations) beyond the scope of the KGML document, and amends missing components to fr...
In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa < 1), increases as R/sup -2/, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring ...
... 500 ppm, boron increases the 0.2% offset strength; results show that boron doping does not appreciably affect ultimate compressive strength; for 0 ...
... by the boron doping in most of the alloys except for Al66Mn9Zr25 + 50 ppm B alloy; permanent deformation at ultimate compressive strength is not ...
Ultimate Compressive Strength of Short Sheet - Stringer Panels With Special. Reference to the Influence of the Riveted Connection Between Sheet and Stringer ...
Cutaneous scarring can cause patients symptoms ranging from the psychological to physical pain. Although the process of normal scarring is well described the ultimate cause of pathological scarring...Full Text Available
... The measured elastic modulus was fairly close to the predicted value, but the ultimate compressive strength (UCS) was quite a bit below the MSC ...
This paper presents extensive non-linear finite element (FE) analysis and formulation development work carried out on the ultimate compressive strength of plates and stiffened panels of ship structures. A review of contemporary designs for large ships was carried out. The existing formulae for plate ultimate compressive strength were reviewed and compared with non-linear FE analysis results. A semi-analytical formula for ultimate compressive strength assessments of stiffened panels was proposed and is described. The developed formula was verified against results using ABAQUS non-linear FE software for a series of 61 stiffened panels and a good agreement between the proposed formula and FE results were achieved. The method was verified against a large number of published FE results and was ...
The most frequent ultimate cause of death is myocardial arrest. In many cases this is due to myocardial hypoxia, generally arising from failure of the coronary macro- and microcirculation to deliver...Full Text Available
The purpose of this paper is to evaluate a complete set of environmental pathways for disposal options and conditions that the Nuclear Regulatory Commission (NRC) may analyze for a low-level radioactive waste (LLW) license application. The regulations pertaining In the past, shallow-land burial has been used for the disposal of low-level radioactive waste. However, with the advent of the State Compact system of LLW disposal, many alternative technologies may be used. The alternative LLW disposal facilities include below- ground vault, tumulus, above-ground vault, shaft, and mine disposal This paper will form the foundation of an update of the previously developed Sandia National Laboratories (SNL)/NRC LLW performance assessment methodology. Based on the pathway assessment for alternative disposal methods, a determination will be made about whether the current methodology can satisfactorily analyze the pathways and phenomena ...
The phosphatidylinositol pathway is implicated in the regulation of numerous cellular functions and responses to extracellular signals. An important branching point in the pathway is the phosphorylation...Full Text Available
Inhibiting insulin/IGF-1 signalling extends lifespan and delays age-related disease in species throughout the animal kingdom. This life-extension pathway, the first to be defined, was discovered through...Full Text Available
Six species having characteristics of plants with the C4 dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon...Full Text Available
Six genes involved in the heparan sulfate and heparin metabolism pathway, DSEL (dermatan sulfate epimerase-like), EXTL1 (exostoses (multiple)-like 1), HS6ST1...Full Text Available
Background & Aimsβ-catenin signaling within the canonical Wnt pathway is essential for pancreas development. However, the pathway is normally down-regulated...Full Text Available
The specific white matter location of all the spinal pathways conveying penile input to the rostral medulla is not known. Our previous studies using rats demonstrated the loss of low but not high threshold...Full Text Available
In this study we compared the molecular signalling elicited by rexinoids, selective retinoid X receptor (RXR)-activators, in several organs (i.e. liver, kidney,...Full Text Available
Purpose:The goal of this study was to use two separate databases to evaluate the clinical outcomes and the economic impact of adherence to Level I Pathways, an evidence-based oncology...Full Text Available
The insulin/IGF-1 signaling (IIS) pathway is a conserved regulator of longevity, development, and metabolism. In Caenorhabditis elegans IIS involves activation of DAF-2 (insulin/IGF-1...Full Text Available
Hematopoiesis is the cumulative result of intricately regulated signaling pathways that are mediated by cytokines and their receptors. Studies conducted over the past 10 to 15 years have revealed that...Full Text Available
Chlorazole fast pink 2BL inhibited the classical complement pathway in rat serum both in vivo and in vitro. The in vitro potency of chlorazole fast pink against the alternative pathway could not be...Full Text Available
AIM: To investigate atrial natriuretic peptide (ANP) secretion from gastric mucosa and the relationship between the ANP/natriuretic peptide receptor type A (NPR-A) pathway and diabetic gastroparesis.METHODS:...Full Text Available
Detailed chemical kinetic reaction mechanisms are developed for combustion of all nine isomers of heptane (C{sub 7}H{sub 16}), and these mechanisms are tested by simulating autoignition of each isomer under rapid compression machine conditions. The reaction mechanisms focus on the manner in which the molecular structure of each isomer determines the rates and product distributions of possible classes of reactions. The reaction pathways emphasize the importance of alkylperoxy radical isomerizations and addition reactions of molecular oxygen to alkyl and hydroperoxyalkyl radicals. A new reaction group has been added to past models, in which hydroperoxyalkyl radicals that originated with abstraction of an H atom from a tertiary site in the parent heptane molecule are assigned new reaction sequences involving additional internal H atom abstractions not previously allowed. This process accelerates autoignition in fuels with tertiary C-H bonds in the ...
Biomass tensile and shear ultimate failure stresses were measured with the aim of identifying biomass 'weakest mode of failure' or 'natural fracture point' as a basis for future grinder designs. Switchgrass (Panicum virgatum L.) ultimate stresses were determined for Alamo and Kanlow varieties over ranges in maturity and moisture content. Alamo had greater ultimate tensile stress than Kanlow (P=0.0091), with mean values of 97.8 and 89.7MPa, respectively. Alamo had greater ultimate shear stress than Kanlow (P=0.0091), with mean values of 20.5 and 17.9MPa, respectively. Shear was the 'weakest mode of failure'. Grinders that use knives, shear bars, and mechanical pinch points that apply opposed-sliding actions are expected to be more energy efficient. Mean ultimate tensile stress and shear stress were significantly different between ...
In the present paper, a possible interaction region layout of the VLEPP based Photon Linear Collider (PLC) with ultimate luminosity is discussed. In order to remove spent electron beams, the crab-crossing scheme is used. The detector is protected from produced pairs and secondary particles by means of the detector magnetic field and a shielding mask. ((orig.)).
The concept of preliminary transmutation of minor actinides before placement to the long-term storage is considered. The purpose of such preliminary transmutation before ultimate storage is to incinerate a part of actinides and to transform another part into new actinides providing low level of radiotoxicity accumulated in the storage. Modes of transmutation in reactors of PWR, PHWR (CANDU), and Superfenix types are compared. Among power reactors, heavy-water PHWR type reactor is most acceptable for preliminary transmutation. (author)
The behavior of melter feed (a mixture of nuclear waste and glass-forming additives) during waste-glass processing has a significant impact on the rate of the vitrification process. We studied the effects of silica particle size and sucrose addition on the volumetric expansion (foaming) of a high-alumina feed and the rate of dissolution of silica particles in feed samples heated at 5 C/min up to 1200 C. The initial size of quartz particles in feed ranged from 5 to 195 {micro}m. The fraction of the sucrose added ranged from 0 to 0.20 g per g glass. Extensive foaming occurred only in feeds with 5-{micro}m quartz particles; particles {ge}150 {micro}m formed clusters. Particles of 5 {micro}m completely dissolved by 900 C whereas particles {ge}150 {micro}m did not fully dissolve even when the temperature reached 1200 C. Sucrose addition had virtually zero impact on both foaming and the dissolution of silica particles. Over 100 sites in the United States are currently tasked with the storage ...
In this paper, an amount of confining reinforcement required for the sufficient flexural ductility of reinforced concrete column was investigated. An equation to calculate the required confining reinforcement ratio was deduced from the analytical investigation and examination on the previous experimental data as to the effects of various factors on the required confining reinforcement ratio. The rotation angle required in plastic hinges, the axial force ratio, the material properties such as concrete strength, and the ratio of core area to the whole area of column sections were employed as the factors. From the examination of the equation, it was shown that the ultimate rotation in plastic hinges calculated by the equation was more conservative than the ultimate rotaion angle of members obtained by test column specimens. It was also indicated that the ultimate rotation angle of members of columns failed in shear was smaller ...
Abstract The Hippo pathway is an evolutionally conserved protein kinase cascade involved in regulating organ size in vivo and cell contact inhibition in vitro by governing cell proliferation and apoptosis. Deregulation of the Hippo pathway is linked to cancer development. Its first core kinase Warts was identified in Drosophila more than 15 years ago, but it gained much attention when other core components of the pathway were identified 8 years later. Major discoveries of the pathway were made during past several years. The core kinase components Hippo, Salvador, Warts, and Mats in the fly and Mst1/2, WW45, Lats1/2, and Mob1 in mammals phosphorylate and inactivate downstream transcriptional co-activators Yorkie in the fly, Yes-associated protein (YAP) and transcriptional co-activator with ...
Intervertebral disc (IVD) cell apoptosis has been suggested to play an important role in promoting the degeneration process. It has been demonstrated that IVD cell apoptosis occurs through either death receptor, mitochondrial or endoplasmic reticulum (ER) pathway. Our study aimed to explore the relationship among these three pathways and grade of IVD degeneration (IVDD). IVDs were collected from patients with lumbar fracture, vertebral tumor, disc herniation or spondylolisthesis. IVDs were distinguished by MRI and histomorphological examination, cell apoptosis was detected by TUNEL staining. Biomarkers of these three apoptosis pathways were detected by RT-PCR and Western blot. Furthermore, the correlation between apoptosis pathways biomarkers and disc pathology were analyzed. Nucleus pulpo...
As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modeling approaches for geosphere performance assessment for a single hypothetical site. The hypothetical site, arbitrarily named Aberg is based on parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The Aberg model domain, boundary conditions and canister locations are defined as a common reference case to facilitate comparisons between approaches. This report presents the results of a discrete fracture pathways analysis of the Aberg site, within the context of the SR 97 performance assessment exercise. The Aberg discrete fracture network (DFN) site model is based on consensus Aberg parameters related to the Aespoe HRL site. Discrete fracture pathways are identified from canister locations in a ...
The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as 'FreedomCAR' (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieving the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993 through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the FreedomCAR and Vehicle Technologies Program provides support and guidance ...
Optimization of radiation shielding for a medium energy accelerator with 60 MeV alpha ions is carried out using the cost-benefit approach. Cost optimum shield thicknesses are estimated for different operating conditions of the accelerator. (author). 5 refs, 1 tab.
Based on the assumption that an accelerated proliferation process prevails in tumour cell residues after surgery, the possibility that treatment acceleration would offer a therapeutic advantage in postoperative...Full Text Available
A general model for wakefield-generated instabilities in linear accelerators, originally developed for cumulative beam breakup [1], is applied to the resistive wall instability. The general solution for various bunch charge distributions and application to various accelerator configurations are presented.
Ion acceleration has now been demonstrated with the IFA-2 collective ion accelerator system. The IFA-2 system is described, photoionization experiments are summarized, and ion results are presented. Using a 1 MeV electron beam and a 30 cm acceleration length, IFA-2 has produced 5 MeV H/sup +/, 10 MeV D/sup +/, and 20 MeV He/sup + +/. This means that accelerating fields of 33 MV/m over 30 cm have been achieved with a controlled collective accelerator for the first time.
The bone mineral content of 109 lumbar vertebrae from 36 different subjects was determined by dual photon absorptiometry. The mean age of the subjects was 58.5 years (range, 31 to 79 years). The ultimate strength of the vertebral bodies was determined during axial compression. Bone mineral content and ultimate compressive strength were correlated (r = 0.86) and the strength was found to increase linearly with increasing amounts of bone mineral content. No differences in this correlation were found in the four vertebral levels (L-4) included in the study, but a difference in this correlation was found between specimens taken from male and female subjects. The results make it possible to estimate the strength of a vertebral body from the knowledge of its bone mineral content as determined by dual photon absorptiometry and provide a basis of estimations of normal and abnormal amounts of bone mineral content in the vertebrae of the lumbar spine. ...
The major projects of the Los Alamos National Laboratory's Accelerator Technology Division are discussed, covering activities that occurred during the first six months of calendar 1982.
Several enzymes of the metabolic pathways responsible for metabolism of cytosolic ribonucleotides and deoxyribonucleotides are located in mitochondria. Studies described in this paper suggest dysfunction of the mitochondria to affect these metabolic pathways and limit the available levels of cytosolic ribonucleotides and deoxyribonucleotides, which in turn can result in aberrant RNA and DNA synthesis. Mitochondrial dysfunction has been linked to genomic instability, and it is possible that the limiting effect of mitochondrial dysfunction on the levels of nucleotides and resulting aberrant RNA and DNA synthesis in part can be responsible for this link. This paper summarizes the parts of the metabolic pathways responsible for nucleotide metabolism that can be affected by mitochondrial dysfunction.
Binding of epidermal growth factor (EGF) to the EGF receptor (EGFR) initiates signal transduction, ultimately leading to altered gene expression. Ligand-activated EGFR is also rapidly internalized...Full Text Available
Compliance mismatch is a significant challenge to long-term patency in small-diameter bypass grafts because it causes intimal hyperplasia and ultimately graft occlusion. Current engineered grafts...Full Text Available
Retinitis pigmentosa (RP) is a heterogeneous group of inherited retinal dystrophies characterised ultimately by the loss of photoreceptor cells. We have recently identified a new gene (EYS) encoding...Full Text Available
Although functional organ stem cells persist in the old, tissue damage invariably overwhelms tissue repair, ultimately causing the demise of an organism. The poor performance of stem cells in an aged...Full Text Available
Most hospitals today are quickly developing special programs and services that are designed to compete for physicians and patients, and ultimately fill unoccupied beds. In an attempt to attract physicians...Full Text Available
SUMMARYTestosterone and estrogen are essential for male behaviors in vertebrates. How these two signaling pathways interact to control masculinization of the brain and behavior...Full Text Available
Political leaders in numerous nations argue for an upper limit of the global average surface temperature of 2 K above the pre-industrial level, in order to attempt to avoid the most serious impacts of climate change. This paper analyzes what this limit implies in terms of radiative forcing, emissions pathways and abatement costs, for a range of assumptions on rate of ocean heat uptake and climate sensitivity. The primary aim is to analyze the importance of ocean heat uptake for radiative forcing pathways that temporarily overshoot the long-run stabilization forcing, yet keep the temperature increase at or below the 2 K limit. In order to generate such pathways, an integrated climate-economy model, MiMiC, is used, in which the emissions pathways generated represent the least-cost solution o...
Myriad genetic and epigenetic alterations are required to drive normal cells toward malignant transformation. These somatic events commandeer many signaling pathways that cooperate to endow aspiring...Full Text Available
This manuscript discusses the physiology of the autonomic nervous system (ANS). The following topics are presented: regulation of activity; efferent pathways; sympathetic and parasympathetic divisions;...Full Text Available
BackgroundThe monolignol biosynthetic pathway interconnects with the biosynthesis of other secondary phenolic metabolites, such as cinnamic acid derivatives, flavonoids and condensed...Full Text Available
Pathway analyses are regarded by National Plant Protection Organizations as a very efficient way to address the risks posed by invasive alien species. Data on import of aquatic plants was obtained from 10 EPPO countries (Austria, Czech Republic, Estonia, France, Germany, Hungary, the Netherlands, Latvia, Switzerland and Turkey) and aggregated in order to consider whether invasive or potentially invasive alien plants could be introduced in the EPPO region through this pathway. This study highlights that this pathway mainly consists of the import of tropical plants for use in aquaria, and which do not represent a risk due to their climatic requirements. However, a few species require thorough attention owing to the threats they cause. Of the 247 species recorded as imported, only 10 are curr...
Ethane oxidation was studied in ethane-grown resting cells (mycelia) of an Acremonium sp. and in cell-free preparations of such mycelia. From resting cell experiments evidence was found for a pathway...Full Text Available
The Liver Carcinogenesis Section uses the modern technologies of molecular biology, cell biology, protein chemistry and genetics to investigate the biochemical and genetic pathways involved in human liver cancer.
In animal models, single-gene mutations in genes involved in insulin/IGF and target of rapamycin signalling pathways extend lifespan to a considerable extent. The genetic, genomic and epigenetic influences...Full Text Available
The SHARP cannon. Hydrogen is compressed in the tube on top, the gun barrel is on bottom. When Jules Verne wrote in 1865 "From Earth to the Moon" he ...
Turbine Afterword The SHARP cannon. Hydrogen is compressed in the tube on top, the gun barrel is on bottom. When Jules Verne wrote in 1865 "From Earth to the Moon" he envisioned...
Substances cross the blood-brain barrier (BBB) by a variety of mechanisms. These include transmembrane diffusion, saturable transporters, adsorptive endocytosis, and the extracellular pathways. Here,...Full Text Available
Pathways of salicylic acid (SA) biosynthesis and metabolism in tobacco have been recently identified. SA, an endogenous regulator of disease resistance, is a product of phenylpropanoid metabolism formed...Full Text Available
The ability of a number of mycobacteria and some of their components to activate complement was examined. Mycobacterium bovis BCG (Glaxo strain), Mycobacterium leprae, Mycobacterium lepraemurium, and...Full Text Available
The load-carrying capacity and ultimate deformation capacity of timber-concrete composite systems can be significantly influenced by the ductility of the connection between the two materials. The use of more ductile connections can increase the load-carrying capacity of the composite system as well as its ultimate deformation capacity. In this work, the potential increase that might be expected for these two parameters due to the use of ductile connections will be assessed through numerical simulations, taking the non-linear behaviour of the connections into account. Furthermore, the connection ductility required to achieve the maximum load capacity depends on the mechanical properties of the connection as well as on the geometric and mechanical properties of the composite system. There ar...
We have made preliminary estimates of charged particles background at the 100x100 GeV Photon Linear Collider with ultimate luminosity. The charged particles background due to electromagnetic processes is located mainly in the small-angle range of the detector. At large angles, the number of background particles is much smaller. Analysis of the background (at least, in the range under consideration) shows that background conditions for the VLEPP-based Photon Linear Collider are better than at the VLEPP electron-positron collider. ((orig.)).
We review the status of free electron laser (FEL) research being conducted at LBL and LLNL as part of a broader program of research on two beam accelerators (TBAs). Induction accelerator-driven FELs for use as power sources for high-gradient accelerators are discussed, along with preliminary cost estimates for this type of power source. Finally, a promising new version of an FEL/TBA is described. 25 refs., 1 fig., 3 tabs.
Linearly polarized laser radiation accelerates electrons to very high velocities and these electron form a sheath layer on the rear side of thin targets where preferentially protons are accelerated. When mass-limited targets are used, the lateral transport of the absorbed laser energy is reduced and the accelerating field is enhanced. For targets consisting of two ion species, heavier ions facilitate formation of quasi-monoenergetic bunch of lighter ions. For circularly polarized light, fast electron production is suppressed by the absence of the oscillatory component of the ponderomotive force. Ions are accelerated on the front side by the separation field and very thin foil can be accelerated as one massive quasi-neutral block. As all ion species acquire the same velocity, this acceleration mechanism is preferred for heavier ions.
In Korea, the Proton Engineering Frontier Project (PEFP) is building a proton linear accelerator facility with energy up to 100MeV and a beam current of 20mA. In this study, a radiation field after shutdown in the accelerator facility of the PEFP was evaluated for the purpose of the radiation shielding by using MCNPX code. A facility modeling was performed for the accelerator tunnel building, accelerator chain, target rooms and beam experiment hall. And radiation source terms were evaluated in the facility. With this facility, model and radiation source terms, the concentration of 41Ar was evaluated and the cooling time satisfying regulation in Korea was calculated.
The current status of research and development in the realm of physics and technology of collective ion acceleration in systems with a virtual cathode (VC) is reviewed. Three major acceleration methods and devices developed on their basis are considered: reflex triodes and their modifications, gas-filled vircators, and vacuum vircators with a Luce diode. Experimental data are outlined and the principal physical models interpreting these data are described. New ion acceleration techniques whose realization involves the production and disappearance of the VC are also discussed. All methods of collective ion acceleration are compared and the possible ways for the further development of this promising scientific field are highlighted. (reviews of topical problems)
Glucose metabolism through glycolysis and hexosamine pathway has been shown to be altered in type 2 diabetes. However, its fate through the pentose phosphate pathway (PPP) is currently unclear....Full Text Available
The rates of synthesis of a class of both secreted and intracellular degradative enzymes in Bacillus subtilis are controlled by a signal transduction pathway defined by at least four regulatory genes:...Full Text Available
2,4-Dichlorophenoxyacetic acid (2,4-D) promotes the accumulation of tryptophan-derived indole-3-acetic acid (IAA) in carrot cell cultures during callus proliferation by a biosynthetic pathway that is...Full Text Available
Immune challenge induces behavioral changes including reduced ingestion of palatable food. Multiple pathways likely contribute to this effect, including viscerosensory pathways controlling hypothalamic...Full Text Available
The insulin signaling pathway, involving protein kinase B (PKB) and mitogen-activated protein kinase (MAPK), mediates the biological response to insulin and several growth factors and cytokines. To investigate the correlation between glucose transporter (Glut) biosynthesis and the insulin signaling pathway activated by novel compounds of Liriope platyphylla (LP9M80-H), alterations in Glut and key protein expression in the insulin signaling pathway were analyzed in the liver and brain of ICR mice treated with LP9M80-H. An in vitro assay showed that the highest level of insulin concentration was observed in the LP9M80-H-treated group, followed by the LP-H, LP-M, LP-E, and LP9M80-C-treated groups. Therefore, LP9M80-H was selected for use in studying the detailed mechanism of the insulin signaling pathway in animal systems. In an in vivo experiment, LP9M80-H induced a significant increase in glucose levels ...
A multiple comparison approach using whole genome transcriptional arrays was used to identify genes and pathways involved in calorie restriction/dietary restriction (DR) life span extension in Drosophila....Full Text Available
Six species having characteristics of plants with the C(4) dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon L. (Bermuda grass), Kyllinga brevifolia Rottb., Amaranthus tricolor L. cv. Early splendour, Kochia childsii Hort., and Portulaca grandiflora Hook (rose moss), responded decisively to 0.1 milliequivalent per liter NaCl supplied to their culture solutions initially containing less than 0.08 microequivalent per liter Na. Chlorosis and necrosis occurred in leaves of plants not receiving sodium. Portulaca failed to set flower in the sodium-deficient cultures. Under similar conditions Poa pratensis L. (Kentucky blue grass) having characteristics of the C(3) photosynthetic pathway made normal growth and did not respond to the addition of sodium. It is concluded from these results and previously reported work that sodium is generally essential for species having the C(4) ...
Six species having characteristics of plants with the C4 dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon L. (Bermuda grass), Kyllinga brevifolia Rottb., Amaranthus tricolor L. cv. Early splendour, Kochia childsii Hort., and Portulaca grandiflora Hook (rose moss), responded decisively to 0.1 milliequivalent per liter NaCl supplied to their culture solutions initially containing less than 0.08 microequivalent per liter Na. Chlorosis and necrosis occurred in leaves of plants not receiving sodium. Portulaca failed to set flower in the sodium-deficient cultures. Under similar conditions Poa pratensis L. (Kentucky blue grass) having characteristics of the C3 photosynthetic pathway made normal growth and did not respond to the addition of sodium. It is concluded from these results and previously reported work that sodium is generally essential for species having the C4 ...
In summary, a scaling analysis of a water-cooled Reactor Cavity Cooling System (RCCS) system was performed based on generic information on the RCCS design of PBMR. The analysis demonstrates that the water-cooled RCCS can be simulated at the ANL NSTF facility at a prototypic scale in the lateral direction and about half scale in the vertical direction. Because, by necessity, the scaling is based on a number of approximations, and because no analytical information is available on the performance of a reference water-cooled RCCS, the scaling analysis presented here needs to be 'validated' by analysis of the steady state and transient performance of a reference water-cooled RCCS design. The analysis of the RCCS performance by CFD and system codes presents a number of challenges including: strong 3-D effects in the cavity and the RCCS tubes; simulation of turbulence in flows characterized by natural circulation, high Rayleigh numbers and low Reynolds numbers; validity of heat transfer ...
The collaboration between the Los Alamos National Laboratory and the National Bureau of Standards (NBS), started in 1979, has led to the development of an advanced c-w microtron accelerator design. The four 2380-MHz NBS accelerating structures, containing a total of 184 accelerating cavities, have been fabricated and delivered. New fabrication methods, coupled with refinements of hydrogen-furnace brazing techniques described in this paper, allow efficient production of side-coupled structures. Success with the NBS RTM led to Los Alamos efforts on similar 2450-MHz accelerators for the microtron accelerator operated by the Nuclear Physics Department of the University of Illinois. Two accelerators (each with 17 cavities) have been fabricated; in 1986, a 45-cavity accelerator is being fabricated by private industry with some assistance from Los ...
The development and occurrence of new electron accelerators and applications are according to the human society development law, as a whole. The period of economic standstill is generating an intense creative activity in the domain of science and engineering which also resulting in great achievements in the field of electron accelerators. This paper presents the basic principle of the electron beam applications and the accelerators required characteristics for their present and potential applications in the domains: radiation sources, diagnostics, radiation processing, energetics, environment, defense and basic sciences. All these are correlated to the new generation of accelerators which, for the acceleration process, may employ electromagnetic fields generated by standard sources, atomic lasers, free electron lasers, Cerenkov effect, Smith - Purcell effect, electron beams, plasma, ...
The United States Department of Energy (U.S. DOE) has recently implemented a series of strategic initiatives to address long-term radiological surveillance needs at former U.S. nuclear test sites in the Marshall Islands. The plan is to engage local atoll communities in developing shared responsibilities for implementing radiation protection monitoring programs for resettled and resettling populations in the northern Marshall Islands. Using the pooled resources of the U.S. DOE and local atoll governments, individual radiological surveillance programs have been developed in whole body counting and plutonium urinalysis in order to accurately assess radiation doses resulting from the ingestion and uptake of fallout radionuclides contained in locally grown foods. Permanent whole body counting facilities have been established at three separate locations in the Marshall Islands including Rongelap Atoll (Figure 1). These facilities are operated and maintained by Marshallese technicians with ...
Within the framework of the cluster approach and the semiempirical SCF MO LCAO method in the CNDO/BW valence approximation, possible pathways have been compared for the dehydroxylation of aluminosilicate systems. It has been shown that dehydroxylation as a result of splitting of a water molecule from an acidic bridge hydroxyl group and a more basic terminal group Al-OH is the most energyfavorable. Apparently, such a dehydroxylation pathway is primarily characteristic for amorphous aluminosilicates. Typical of crystalline aluminosilicates at moderate heat-treating temperature is dehydroxylation through splitting of a water molecule from an acidic bridge hydroxyl group and a neutral Si-OH group; at higher temperatures, there is a possible pathway of dehydroxylation of highsilica zeolites as a result of condensation of two acidic surface hydroxyls.
Purpose - The article discusses how care programmes and integrated care pathways can be linked, finding ways to improve healthcare process professional and logistical quality from a supply chain and a network point-of-view. Design/methodology/approach - The authors argue that owing to cost containment goals and increasing healthcare demand, healthcare services systems are challenged to improve service quality, whilst at the same time finding ways to improve delivery processes. It explores if the combination of two instruments, care programmes and integrated care pathways, can meet both goals. This combination is illustrated by an example from the Institute of Mental Health Care Eindhoven en de Kempen. Findings - Analysis suggests that care programmes can be combined with integrated care pa...
The cyclic voltammetry indicated that the oxygen reduction reaction (ORR) proceeded by the four-electron pathway mechanism on larger Ag particles (174 nm), and that the ORR proceeded by the four-electron pathway and the two-electron pathway mechanisms on finer Ag particles (4.1 nm), simultaneously. The kinetics towards ORR was measured at a rotating disk electrode (RDE) with Ag/C electrode. The number of exchanged electrons for the ORR was found to be close to four on larger Ag particles (174 nm) and close to three on finer Ag particles (4.1 nm). The zinc-air battery with Ag/C catalysts (25.9 nm) was fabricated and examined. (author)
"American dominance in the study and development of high-energy particle physics may be seriously compromised, according to a report issued by the National Academy of Sciences, unless efforts are made to ensure that the next high-energy particle accelerator - the International Linear Collider (ILC) - will be constructed in the U.S.
Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy...Full Text Available
We describe the lethal, recessive accelerated-cell-death11 Arabidopsis mutant (acd11). Cell death in acd11 exhibits characteristics of animal apoptosis...Full Text Available
A linear induction accelerator that produces a beam of energetic heavy ions (T -- 10 GeV, A -- 200 amu) is a prime candidate as a driver for an inertial fusion power plant. Some early perceptions were that heavy-ion drive fusion would not be cost-competitive with other power sources because of the high cost of the accelerators. However, improved understanding of the physics of heavy-ion transport and acceleration (supported by experimental results), combined with advances in accelerator technology, have resulted in accelerator design costs -- 50% of previous estimates. As a result, heavy-ion drive fusion power plants are now projected to be cost-competitive with other conceptual fusion power plants. A brief formulation of transport and acceleration physics is presented here, along with a description of the induction Linac cost optimization code LIACEP. Cost ...
A linear induction accelerator that produces a beam of energetic heavy ions (T #approx =# 10 GeV, A #approx =# 200 am#mu#) is a prime candidate as a driver for an inertial fusion power plant. Some early perceptions were that heavy-ion driven fusion would not be cost-competitive with other power sources because of the high cost of the accelerators. However, improved understanding of the physics of heavy-ion transport and acceleration (supported by experimental results), combined with advances in accelerator technology, have resulted in accelerator design costs -- 50% of previous estimates. As a result, heavy-ion driven fusion power plants conceptual fusion power plants. A brief formulation of transport and acceleration physics is presented here, along with a description of the induction Linac cost optimization code LIACEP. Cost trends are presented and discussed, ...
This paper describes the needs, reasoning, approaches, and technical details to establish a practical accelerated weathering test (AWT) protocol for indoor testing of the photothermal stability of encapsulation materials and encapsulated solar cells and minimodules.
A simple beam-forming system is described for the electrostatic accelerator of the Scientific-Research Institute of Nuclear Physics of Moscow State University. The system allows the beam to be focused on targets at various distances for a conductor potential of from 1 to 4 MV and beam currents of up to 35 #mu# A.
The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of 14C/C ratio, independent of chemical separation procedures....Full Text Available
The major projects of the Los Alamos National Laboratory's Accelerator Technology Division are discussed, covering activities that occurred during the first six months of calendar 1982.
There are several on-going projects of e"+e"- colliders. If they are constructed, we can convert them into photon-photon (#gamma#-#gamma#) colliders by converting electron beams into #gamma# beams, irradiating laser beams just before the interaction point. In this report we discuss the technical issues on the accelerator.
OBJECTIVE: To increase cost-efficiency while maintaining the standard of medical care, an accelerated surgical stay program for patients having breast surgery was instituted. SUMMARY BACKGROUND DATA:...Full Text Available
Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting the joint project integrating both the Neutron Science Project (NSP) of JAERI and the Japan Hadron Facility Project (JHF) of KEK for comprehensive studies on basic science and technology using high-intensity proton accelerator. This document describes the joint project prepared by the Joint Project Team of JAERI and KEK to construct accelerators and research facilities necessary both for the NSP and the JHF at the site of JAERI Tokai Establishment. It was originally written in English and translated into Japanese with some corrections. (author)
Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2#pi#/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is photo excited with short (6 psec) laser pulses giving design peak currents of a few hundred amperes. The system will be utilized to carry out infra-red FEL studies and investigation of new high gradient accelerating structures.
The two model MP Tandem Van de Graaff accelerators at Brookhaven have been used in a four-stage accel-decel configuration to produce highly stripped low energy heavy ions. The performance in this mode of operation has now been substantially improved by modifications of the second accelerator. The inclined field acceleration tube electrodes at the exit of this accelerator were replaced by straight electrodes, the vacuum was improved and the maximum negative terminal potential was increased. Higher intensity beams of heavier highly stripped ions can now be produced at lower energies than before.
The motivation for using a tandem electrostatic accelerator as an electron accelerator for a free electron laser (FEL) is presented. The adaptation of the HVEC EN tandem at the Weizmann Institute for this purpose, electron beam optics and nonlinear FEL computation relevant for this FEL realization are described. In the tandem configuration the terminal is held at a positive potential. The electron beam is accelerated from ground potential to the terminal in one beam tube and then decelerated down the other beam tube. The FEL wiggler and cavity are at the terminal. Due to the beam energy recovery this scheme produces a high power beam at the terminal with a small investment in electrical power. (orig.).
Ni-free shape memory alloys are promising functional materials for medical applications. A newly developed Ti-Mo based shape memory alloy shows superelasticity after thermomechanical treatment. However, the microstructure evolution and precipitation during thermomechanical processes are still not well understood. In the present paper, compressive deformation behavior at a series of temperatures of 298K - 973K and tensile deformation behavior of the alloy after aged at 573K - 973K have been investigated systematically. It is found that the compressive yield stress and ultimate compressive strength change with the deformation temperature. The ultimate tensile strength and yield stress of aged specimens also change with the aging temperature following a non-linear relationship. Microstructures of aged specimens as well as effects of lattice softening and aging-induced precipitates on the deformation behavior have been investigated and discussed.
Tthe acceleration of a liquid from a cylindrical container by the products of instantaneous detonation of a superimposed explosive charge (implosion method) is studies numerically in a two-dimensional formulation. Analytical formulas for the asymptotic velocities of liquid expansion and acceleration of the container body were obtained using numerical calculations in a one-dimensional approximation. The effect of the fracture of the body on the velocity of liquid expansion was studied in a two-dimensional formulation.
The SciDAC2 accelerator project at SLAC aims to simulate an entire three-cryomodule radio frequency (RF) unit of the International Linear Collider (ILC) main Linac. Petascale computing resources supported by advances in Applied Mathematics (AM) and Computer Science (CS) and INCITE Program are essential to enable such very large-scale electromagnetic accelerator simulations required by the ILC Global Design Effort. This poster presents the recent advances and achievements in the areas of CS/AM through collaborations.
A prototype of a muffin-tin accelerating structure operating at 32 times the SLAC frequency (2.856 GHz) was built for research in high gradient acceleration. A traveling-wave design with single input and output feeds was chosen for the prototype which was fabricated by wire electrodischarge machining. Features of the mechanical design for the prototype are described. Design improvements are presented including considerations of cooling and vacuum.
The original purpose of this research was an investigation into the use of slow space charge waves on weakly relativistic electron beams for ion acceleration. The work had three main objectives namely, the development of a suitable ion injector, the growth and study of the properties of slow space charge waves on an electron beam, and a combination of the two components parts into a suitable proof of principle demonstration of the wave accelerator. This work focusses on the first two of these objectives.
Growing evidence suggests the Wnt family of secreted glycoproteins and their associated signaling pathways, linked to development, are recapitulated during wound repair and regeneration events. However,...Full Text Available
The central nervous system regulates peripheral immune responses via the vagus nerve, the primary neural component of the cholinergic anti-inflammatory pathway. Electrical stimulation of the...Full Text Available
Forward and reverse genetic experiments have both played important roles in revealing critical aspects of mammalian signal transduction pathways in cell culture experiments. Only recently have we begun...Full Text Available
Subcellular-fractionation techniques were used to characterize the endocytic pathway followed by ricin in rat liver in vivo and tentatively identify the site(s) at which the ricin interchain disulphide...Full Text Available
The lesion bypass pathway, which is regulated by monoubiquitination of proliferating cell nuclear antigen (PCNA), is essential for resolving replication stalling due to DNA lesions. This process is...Full Text Available
While it has been established that microRNAs (miRNAs) play key roles throughout development and are dysregulated in many human pathologies, the specific processes and pathways regulated by individual...Full Text Available
Temperature sensing is crucial for homeotherms, including human beings, to maintain a stable body core temperature and respond to the ambient environment. A group of exquisitely temperature-sensitive...Full Text Available
Purpose of ReviewThe vertebrate cap’n’collar family transcription factor Nrf2 and its invertebrate homologs SKN-1 (in worms) and CncC (in flies) function...Full Text Available
FRAXA is one of a number of fragile sites in human chromosomes that are induced by agents like fluorodeoxyuridine (FdU) that affect intracellular thymidylate levels. FRAXA coincides with a >200...Full Text Available
p53 is one of the most mutated tumor suppressors in human cancers and as such has been intensively studied for a long time. p53 is a major orchestrator of the cellular response to a broad array...Full Text Available
SummaryIn vivo tumor cell migration through integrin-dependent pathways is key to the metastatic behavior of malignant cells. Using quantitative in vivo...Full Text Available
The target of rapamycin (TOR) pathway regulates cell growth and aging in various organisms. In Saccharomyces cerevisiae, silent information regulator 2 (Sir2) modulates cellular senescence. Moreover,...Full Text Available
BackgroundThermogenic brown adipose tissue has never been described in birds or other non-mammalian vertebrates. Brown adipocytes in mammals are distinguished from the more common...Full Text Available
The canonical Wnt/β-catenin pathway plays a pivotal role in regulating embryogenesis and tumorigenesis by promoting cell proliferation. BAMBI (BMP and activin membrane-bound inhibitor) has...Full Text Available
In honor of the 50th anniversary of the “organizational hypothesis,” this paper reviews work on sexual differentiation of the spinal cord and peripheral nervous system....Full Text Available
The p53 tumour suppressor plays a pivotal role in the prevention of oncogenic transformation. Cancers frequently evade the potent antitumour surveillance mechanisms of p53 through mutation of the TP53...Full Text Available
Syndrome X is a combination or co-occurrence of several known cardiovascular risk factors (including central obesity, dyslipidemias, fatty liver disease, hyperinsulinemia, insulin resistance,...Full Text Available
Dal82p binds to the UISALL sites of allophanate-induced genes of the allantoin-degradative pathway and functions synergistically with the GATA family Gln3p and Gat1p transcriptional...Full Text Available
Understanding the mechanisms whereby information encoded within patterns of action potentials is deciphered by neurons is central to cognitive psychology. The multiprotein complexes formed by...Full Text Available
Cysticercosis is an infection with larval cysts of the cestode Taenia solium. Through pathways that are incompletely understood, dying parasites initiate a granulomatous reaction that,...Full Text Available
Somatic embryogenesis (SE) is the developmental restructuring of somatic cells towards the embryogenic pathway and forms the basis of cellular totipotency in angiosperms. With the availability of full-length...Full Text Available
Photosynthetic (Ps) electron transport pathways often contain multiple electron carriers with overlapping functions. Here we focus on two c-type cytochromes (cyt) in facultative phototrophic...Full Text Available
French scientists think they have discovered one of the key steps in the methanol-to-gasoline reaction pathway and their British counterparts have learned a new way of converting methanol into acetic acid without carbon monoxide.
The prevalence of obesity among children, adolescents and adults has been dramatically increasing worldwide during the last several decades. The obesity epidemic has been recognized as one of...Full Text Available
The ubiquitin–proteasome pathway is the principal system for extralysosomal protein degradation in eukaryotic cells, and is essential for the regulation and maintenance of basic cellular processes,...Full Text Available
SUMMARYSmall bowel epithelium is at the frontline of intestinal barrier function. Restitution is considered to be the major determinant of epithelial repair as function recovers...Full Text Available
Rapamycin inhibits the mTOR (target of rapamycin) pathway and extends lifespan in multiple species. The tuberous sclerosis complex (TSC) protein is a negative regulator of mTOR. In humans, loss of the...Full Text Available
Previous studies in several different trigeminal nerve injury/inflammation models indicated that the hyperexcitability of primary afferent neurons contributes to the pain pathway underlying mechanical...Full Text Available
Human longevity is in part genetically determined, and the insulin/IGF-1 signal transduction (IIS) pathway has consistently been implicated. In humans, type 2 diabetes is a frequent disease that results...Full Text Available
... Weiss, S., D. Kobiler, H. Levy, H. Marcus, A. Pass, N. Rothschild, and Z ... of Bacillus anthracis spores conferred by a protective antigen-based vaccine in rabbits ...
Three homeologous genes encoding a sucrose (Suc) transporter (SUT) in hexaploid wheat (Triticum aestivum), TaSUT1A, 1B, and 1D, were...Full Text Available
BackgroundIn Saccharomyces cerevisiae galactose is initially metabolized through the Leloir pathway after which glucose 6-phosphate enters glycolysis. Galactose...Full Text Available
While specific signalling cascades involved in aging, such as the insulin/IGF-1 pathway, are well-described, the actual metabolic changes they elicit to prolong lifespan remain obscure. Nevertheless,...Full Text Available
OBJECTIVE—Identification of arterial genes and pathways altered in obesity and diabetes.RESEARCH DESIGN AND METHODS—Aortic gene expression profiles of...Full Text Available
considers a wide range of pathways to advance the nation's current capabilities. The present ... opment of new energy sources, aging infrastruc- ture and ... and manufacturing TA strategic roadmap as brief- ..... pellant storage and transport. ...
...this pathway study the following two focus modules (in addition to the six core modules) and carry out a research investigation within this theme: Agricultural Production Systems Considers the type of farming systems that have evolved globally in relation to the prevailing agro-climatic zones, the influences of economic factors ...
Microorganisms in the environment can often adapt to use xenobiotic chemicals as novel growth and energy substrates. Specialized enzyme systems and metabolic pathways for the degradation of man-made...Full Text Available
BackgroundThe zebrafish is recognized as a versatile cancer and drug screening model. However, it is not known whether the estrogen-responsive genes and signaling pathways that are...Full Text Available
BackgroundIsopentenyl diphosphate (IPP), a common biosynthetic precursor to the labdane diterpene forskolin, has been biosynthesised via a non-mevalonate pathway. Geranylgeranyl...Full Text Available
As part of the study of cytokinin metabolic pathways, an enzyme, adenosine phosphorylase (EC 2.4.2.-), which catalyzed the ribosylation of N6-(Δ2-isopentenyl)adenine,...Full Text Available
Melanoma is one of the most aggressive cancers, and its incidence is increasing. These tumors derive from the melanocyte lineage and remain incurable after metastasis. Here we report that SONIC HEDGEHOG...Full Text Available
Spike-timing-dependent plasticity (STDP), a form of Hebbian plasticity, is inherently stabilizing. Whether and how GABAergic inhibition influences STDP is not well understood. Using a model neuron driven...Full Text Available
The identification of predictive biomarkers is at the core of modern toxicology. So far, a number of approaches have been proposed. These rely on statistical inference of toxicity response from either...Full Text Available
Hematopoietic stem and progenitor cell (HSPC) expansion is regulated by intrinsic signaling pathways activated by cytokines. The intracellular kinase JAK2 plays an essential role in cytokine signaling,...Full Text Available
Blindness leads to a major reorganization of neural pathways associated with touch. Because incoming somatosensory information influences motor output, it is plausible that motor plasticity occurs in...Full Text Available
Dysregulation of the alternative pathway of complement activation, caused by mutations or polymorphisms in the genes encoding factor H, membrane co-factor protein, factor I or factor B, is associated...Full Text Available
BackgroundSerine proteinase inhibitors (Serpins) are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in...Full Text Available
Summary.? It is widely believed that hepatocellular cancer (HCC), especially HBV associated HCC, is highly resistant to chemotherapy. To investigate the molecular influence of HBx protein on multidrug resistance (MDR) in HCC and the potential role of the NF-?B pathway in this process. We established HBx-expressing cells by liposome-mediated transfection of the HBx into the HepG2 cell line. We found that HBx expression in HCC cells induces drug resistance against multiple drugs, a significantly lower apoptosis ratio in HepG2-HBx and HepG2.2.15 cells, compared with HepG2 and HepG2-3.1 cells (P?HCC cells were downregulated by IMD-0354 treatment, which is the NF-?B pathway inhibitor. Taken together, these results suggest that HBx protein might be one of the causes for the occurrence of MDR in HCC, and the NF-?B pathway might be involved in this change. PMID:21914061
All molybdenum enzymes except nitrogenase contain a common molybdenum cofactor, whose organic moiety is a novel pterin called molybdopterin (MPT). To assist in elucidating the biosynthetic pathway of...Full Text Available
Salicylic acid (SA) is an important component of systemic-acquired resistance in plants. It is synthesized from benzoic acid (BA) as part of the phenylpropanoid pathway. Benzaldehyde (BD), a potential...Full Text Available
To define the import pathway for apoiso-1-cytochrome c in vivo, the coding region for bacterial chloramphenicol acetyltransferase (CAT) or yeast copper metallothionein (CuMT) was fused to the carboxy...Full Text Available
The intramembrane aspartyl protease γ-secretase plays a fundamental role in several signaling pathways involved in cellular differentiation and has been linked with a variety of human diseases,...Full Text Available
During a study on the mTor pathway in the rat kidney we observed a striking increase of the phosphorylation of the S6 kinase in mitosis. In cryostat sections of perfusion-fixed tissue mitotic cells...Full Text Available
Auxin modulates diverse plant developmental pathways through direct transcriptional regulation and cooperative signaling with other plant hormones. Genetic and biochemical approaches have clarified...Full Text Available
The compromised abilities to localize sounds and to understand speech are two hallmark deficits in aged individuals. The auditory cortex is necessary for these processes, yet we know little...Full Text Available
The supramammillary nucleus (SuM) provides substantial projections to the hippocampal formation. This hypothalamic structure is involved in the regulation of hippocampal theta rhythm and therefore...Full Text Available
Chronic colonization of the human stomach by Helicobacter pylori, a Gram-negative bacterium, is the major cause of chronic gastritis, peptic ulcers and gastric cancer. Recent...Full Text Available
Purpose of reviewSevere congenital neutropenia (SCN) is a primary immunodeficiency in which lack of neutrophils causes inadequate innate immune host response to bacterial...Full Text Available
Exteriorized phosphatidylserine (PS) residues in apoptotic cells trigger rapid phagocytosis by macrophage scavenger receptor pathways. Mimicking apoptosis with liposomes containing PS may represent...Full Text Available
All eukaryotes require mitochondria for survival and growth. The origin of mitochondria can be traced down to a single endosymbiotic event between two probably prokaryotic organisms. Subsequent evolution...Full Text Available
A prevailing theory proposes that the brain's two visual pathways, the ventral and dorsal, lead to differing visual processing and world representations for conscious perception than those for action....Full Text Available
BackgroundNeurofibromatosis type 1 (NF1) is a common monogenic tumor-predisposition disorder that arises secondary to mutations in the tumor suppressor gene NF1....Full Text Available
The aromas of fruits, vegetables, and flowers are mixtures of volatile metabolites, often present in parts per billion levels or less. We show here that tomato (Lycopersicon esculentum...Full Text Available
Glioblastoma, the most common malignant brain tumor, is among the most lethal and difficult cancers to treat. Although epidermal growth factor receptor (EGFR) mutations are frequent in glioblastoma,...Full Text Available
Acetaminophen (APAP), a widely used analgesic and antipyretic that is considered to be relatively safe at recommended doses, is the leading cause of drug-induced liver failure in the United States....Full Text Available
The p21-activated kinases (PAKs), immediate downstream effectors of the small G-proteins of the Rac/cdc42 family, are critical mediators of signaling pathways regulating cellular behaviors and...Full Text Available
mRNA is sequestered and turned over in cytoplasmic processing bodies (PBs), which are induced by various cellular stresses. Unexpectedly, in Saccharomyces cerevisiae, mutants of the...Full Text Available
It has previously been established that muscles become active in response to deviations from a threshold (referent) position of the body or its segments, and that intentional motor actions result from...Full Text Available
BackgroundMammalian antimicrobial peptides (AMPs) are effectors of the innate immune response. A multitude of signals coming from pathways of mammalian pathogen/pattern recognition...Full Text Available
Carbohydrate/citrate cometabolism in Lactococcus lactis results in the formation of the flavor compound acetoin. Resting cells of strain IL1403(pFL3) rapidly consumed citrate while...Full Text Available
The mitogen-activated protein kinase/extracellular regulated kinase (MAPK/ERK) pathway plays a key role in mediating estrogen actions in the brain and neuronal sensitization during inflammation....Full Text Available
Store-operated Ca2+ entry (SOCE) is a ubiquitous Ca2+ influx pathway involved in control of multiple cellular and physiological processes including cell proliferation. Recent evidence...Full Text Available
Klebsiella pneumoniae is able to grow anaerobically with citrate as a sole carbon and energy source by a fermentative pathway involving the Na+-dependent citrate...Full Text Available
BackgroundAs the first pathway-specific enzyme in carotenoid biosynthesis, phytoene synthase (PSY) is a prime regulatory target. This includes a number of biotechnological approaches...Full Text Available
Recently, CID755673 was reported to act as a highly selective inhibitor of protein kinase D (PKD). In the course of experiments using CID755673, we noticed that it exerted unexpected stimulatory...Full Text Available
In most insect species, juvenile hormones regulate critical physiological processes such as metamorphosis and reproduction. In insects, these sesquiterpenoids are synthesized by retrocerebral endocrine...Full Text Available
Tyrosinase or polyphenol oxidase (EC 1.14.18.1) is the key enzyme in melanin biosynthesis and in the enzymatic browning of fruits and vegetables. The role of tyrosinase in the secondary metabolism of...Full Text Available
BackgroundNetwork visualization would serve as a useful first step for analysis. However, current graph layout algorithms for biological pathways are insensitive to biologically...Full Text Available
Autophagy is an evolutionarily conserved degradative pathway that has been implicated in a number of physiological events important for human health. This process was originally identified as a response...Full Text Available
IntroductionBRAF (v raf murine sarcoma viral oncogene homologue B1) is a serine-threonine kinase involved in the mitogen-activated protein kinase (MAPK) signalling pathway, known...Full Text Available
Muscarinic cholinergic receptors modulate dopaminergic function in brain pathways thought to mediate cocaine's abuse-related effects. Here, we sought to confirm and ...Full Text Available
Lovatt et al. (1979 Plant Physiol 64: 562-569) have previously demonstrated that end-product inhibition functions as a mechanism regulating the activity of the orotic acid pathway in...Full Text Available
We used tryptophan auxotrophs of the dicot Arabidopsis thaliana (wall cress) to determine whether tryptophan has the capacity to serve as a precursor to the auxin, indole-3-acetic acid (IAA). Quantitative...Full Text Available
Anxiety may cause adverse outcomes through physiologic pathways in patients with cardiac disease. The purpose of this dissertation was to investigate anxiety and its correlates in persons with acute myocardial infarction (AMI) and heart failure (HF). The ...
The chlorophyll fluorescence characteristics of mesophyll and bundle-sheath thylakoids from plant species with the C4 dicarboxylic acid pathway of photosynthesis were investigated using flow cytometry....Full Text Available
Physical system conceptual models are developed to illustrate the various interconnecting pathways of metal flow. Economic use of mercury and cadmium, as representative toxic heavy metals, is inventoried,...Full Text Available
BackgroundGenomics has substantially changed our approach to cancer research. Gene expression profiling, for example, has been utilized to delineate subtypes of cancer, and facilitated...Full Text Available
Atherosclerosis is an inflammatory process leading to enhanced cellular proliferation, apoptosis, and vasa vasorum (VV) neovascularization. While both diabetes mellitus (DM) and hypercholesterolemia...Full Text Available
A remarkable discovery of recent years is that, despite the complexity of ageing, simple genetic interventions can increase lifespan and improve health during ageing in laboratory animals. The pathways...Full Text Available
Twenty-four patients with infective endocarditis (IE) are described, fourteen with Staph. aureus and ten with other organisms. Despite the acute nature of the infection, ten of the fourteen with Staph....Full Text Available
Normal urinary bladder function requires contraction and relaxation of the detrusor smooth muscle (DSM). The DSM undergoes compensatory hypertrophy in response to partial bladder outlet obstruction...Full Text Available
BackgroundThe pH is an important parameter controlling many metabolic and signalling pathways in living cells. Recombinant fluorescent pH indicators (pHluorins) have come into vogue...Full Text Available
In addition to inducing new transcriptional activities that lead within a few hours to the accumulation of heat shock proteins (Hsps), heat shock activates within minutes the major signaling transduction...Full Text Available
Redd1, a recently discovered stress-response gene, is regulated by hypoxia via hypoxia-inducible factor 1 (HIF-1) and by DNA damage via p53/p63; however, the signaling pathway by which its expression is induced by hypoxia has not been elucidated. We demonstrated that the up-regulation of Redd1 transcription by hypoxia and high cell density (HCD) depends on cooperation between Sp1 and HIF-1#alpha# downstream of the PI3K/Akt pathway.
Schemata for modelling combustion processes do not yet include reaction rates for oxygenated fuels like methylal (DMM) which is considered as an additive or replacement for diesel due to its low sooting propensity. Density functional theory (DFT) studies of the possible reaction pathways for different dissociation steps of methylal are presented. Cleavage of a hydrogen bond to the methoxy group or the central carbon atom were simulated at the BLYP/6-311++G{sup **} level of theory. The results are compared to the experiment when dissociating and/or ionising DMM with femtosecond pulses. (author) 1 fig., 1 tab., 1 ref.
Macroautophagy is a multistep, vacuolar, degradation pathway terminating in the lysosomal compartment, and it is of fundamental importance in tissue homeostasis. In this review, we consider macroautophagy in the light of recent advances in our understanding of the formation of autophagosomes, which are double-membrane-bound vacuoles that sequester cytoplasmic cargos and deliver them to lysosomes. In most cases, this final step is preceded by a maturation step during which autophagosomes interact with the endocytic pathway. The discovery of AuTophaGy-related genes has greatly increased our knowledge about the mechanism responsible for autophagosome formation, and there has also been progress in the understanding of molecular aspects of autophagosome maturation. Finally, the regulation of au...
The dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL) uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system is capable of accelerating any charge to mass ratio particle. Applications of high gradient proton and electron versions of this accelerator will be discussed. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, photoconductive switches and compact proton sources.
Inhibition of the phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway is an appealing method for decreasing the immunoresistance and augmenting T cell-mediated immunotherapy. A major impediment to this strategy is the impact of conventional PI3K/mTOR pathway inhibitors on T cell function. In particular, rapamycin, is a well-known immunosuppressant that can decrease the activity of the PI3K/mTOR pathway in tumor cells, but also has a profound inhibitory effect on T cells. Here we show that Honokiol, a natural dietary product isolated from an extract of seed cones from Magnolia grandiflora, can decrease PI3K/mTOR pathway-mediated immunoresistance of glioma, breast and prostate cancer cell lines, without affecting critical proinflammatory T cell functions. Specifically, we show that at doses sufficient to down-regulate levels of phospho-S6 and the negative immune regulator B7-H1 ...
Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. ...
We consider a unified model of Fe ion acceleration in the solar corona. The model comprises charge-changing processes, Coulomb energy losses, and both regular and stochastic acceleration. At a given acceleration scenario, the type of acceleration is found to have a minor effect on the mean charge states, but the shapes of the charge-state distributions produced by regular acceleration and by stochastic acceleration are different. During a continual acceleration at coronal temperatures, iron ions typically follow rising trajectories on the charge-energy plane. These trajectories are situated below the mean equilibrium charge curve defined from the balance of ionization and recombination at fixed energy. During stopping, the iron ions cross the equilibrium charge curve and run through a series of charge states above the mean equilibrium charge ...
Compact dielectric wall (DWA) accelerator technology is being developed at the Lawrence Livermore National Laboratory. The DWA accelerator uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. Its high electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The DWA concept can be applied to accelerate charge particle beams with any charge to mass ratio and energy. Based on the DWA system, a novel compact proton therapy accelerator is being developed. This proton therapy system will produce individual pulses that can be varied in intensity, energy and spot width. The system will be capable of being sited in a conventional linac vault and provide intensity modulated rotational therapy. The status of the developmental new ...
When biomass is used as fuel for thermal conversion plants, minerals from the fuel can be responsible for major problems. Generally, these problems are associated with the existence and development of low melting compounds or eutectics, which form sticky layers. In a fluidised bed, this can result in bed-agglomeration and defluidisation. This causes local high temperature, which often accelerates the process. It ultimately can lead to a completely sintered bed content with a glassy phase gluing the bed particles together and shut-down of the plant. The main objective of the title project is to develop a methodology to predict ash/bed agglomeration and sintering problems, to indicate related problems and, furthermore, to identify solution methods to make different types of biomass streams more viable for energy production. Within the present study, selected fuels are subjected to different existing methods together with some new ones, in order ...
Efficient and economical utilization of wind power will require the ability to measure and ultimately predict the effects fluctuations in the incident wind will have on a wind turbine. In order to quantitatively assesss these effects, experimental techniques have been developed which allow analysis of full-scale performance of wind turbines with particular emphasis on the effects caused by turbulence in the incident wind. Examples of these techniques are presented using data from the DOE/Sandia Vertical Axis Wind Turbine (VAWT) program.
To the crushed ore leaching is applied. The resulting solid-liquid mixture is fed to a hydro-cyclon grading facility; here the superfine grain is separated before the concentrated mixture can be filtered or centrifuged. The grading is done in several steps. From the liquid, ultimately ridded of the solid, uranium compounds are precipitated and the yellow cake is obtained. (DG).
An AHR (Advanced HANARO Reactor) based on the HANARO has been conceptually developed for the future needs of research reactors. Generally, a natural convection cooling in nuclear installations is an ultimate heat removal mechanism as an inherent safety feature. This paper presents the preliminary thermal hydraulic characteristics and safety margins for a natural convection cooling in the AHR.
Certain transition metal chalcogenides are promising materials for use as cathodes in nonaqueous lithium batteries involving the intercalation into these layered compounds. The electrochemical behavior of the chalcogenides depends on various properties such as structure, stoichiometry, electrical conductivity, crystal morphology, etc. The influence of these properties and of the ultimate practical application of the battery on the selection of cathode material is discussed. Battery performance of selected cathode materials is discussed and life limitations due to the limited cycle life of lithium anodes are outlined. 15 refs.
The mechanical properties of TS 6 (Ti--10 percent Cr--7 percent V--3.5 percent Mo--3 percent Al) alloy were studied. Results are presented in plots showing yield stress vs cold work, notched tensile strength vs unnotched tensile strength, and ultimate tensile strength vs test temperature.
An energy frontier or QCD Explorer ep and collider can be realized by colliding high-energy photons generated by Compton backscattered off a CLIC electron beam, at either 75 GeV or 1.5 TeV, with protons or ions stored in the LHC. In this study we discuss a performance optimization of this type of collider by tailoring the parameters of both CLIC and LHC. An estimate of the ultimately achievable luminosity is given.
The Tank Waste Remediation System (TWRS) Information Systems Definition architecture evaluated information Management (IM) processes in several key organizations. The intent of the study is to identify improvements in TWRS IM processes that will enable better support to the TWRS mission, and accommodate changes in TWRS business environment. The ultimate goals of the study are to reduce IM costs, Manage the configuration of TWRS IM elements, and improve IM-related process performance.
This document defines the requirements for the GPRS (General Packet Radio Service) infrastructure as part of the Dutch Smart Meter Specification. In this document all requirements originating from the NTA 8130, or additionally surveyed by a delegation of the Dutch grid operators, are presented in tables. Each requirement is tightly connected to one or more business use cases presented in the document. The ultimate goal of this procedure is to reduce ambiguity of the requirements due to a better understanding of the requirements.
... and pathogen transmission. Because the ultimate object of stem cell research is cell-based clinical therapy, hES cells should ... 4%) Supported by grants (SC12021 and SC11012) from Stem Cell Research...
The added incentive to modify electric use under hourly versus monthly market-based pricing is small for most mass market customers in Upstate New York. If the ultimate policy goal of demand-response programs is to reduce peak load, then promoting conservation measures under monthly market-based pricing holds more promise. (author)
The aim is to provide accurate data on elevation change due to mining activity, via the application of interferometry with ERS SAR data. Ultimately, these elevation changes can then be fed into subsidence models. Interferometry results are presented showing initial evidence of subsidence occurring within the 35 day repeat orbit period of the ERS satellites. The result of extending the monitoring period beyond 35 days is also shown.
Radiation-and-thermal-combined degradation of ethylene-propylene rubber (EP rubber) and chlorosulfonated polyethylene (CSM) as cable insulating and jacketing materials were evaluated by accelerated aging tests and a method to assess the lifetime of these materials under practical application was studied. EP rubber and CSM of experimental formulation were degraded at accelerated rates, that are 50 [approx] 1000 times the degradation rate under a standard condition (1Gy/h, 50degC). The degradation was investigated by measuring the tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for both EP rubber and CSM were in proportion to increase in accelerated rate. Behaviors of elongation changes showed little difference with accelerated rate. EP rubber lifetime estimated from sequential aging test had a tendency to extend beyond that from ...
Radiation-and-thermal-combined degradation of ethylene-propylene rubber (EP rubber) and chlorosulfonated polyethylene (CSM) as cable insulating and jacketing materials were evaluated by accelerated aging tests and a method to assess the lifetime of these materials under practical application was studied. EP rubber and CSM of experimental formulation were degraded at accelerated rates, that are 50 #approx# 1000 times the degradation rate under a standard condition (1Gy/h, 50degC). The degradation was investigated by measuring the tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for both EP rubber and CSM were in proportion to increase in accelerated rate. Behaviors of elongation changes showed little difference with accelerated rate. EP rubber lifetime estimated from sequential aging test had a tendency to extend beyond that from ...
Particle physics is driven by five great topics. Neutrino oscillations and masses are now at the fore. The standard model with extensions to supersymmetry and a Higgs to generate mass explains much of the field. The origins of CP violation are not understood. The possibility of extra dimensions has raised tantalizing new questions. A fifth topic lurking in the background is the possibility of something totally different. Many of the questions raised by these topics require powerful new accelerators. It is not an overstatement to say that for some of the issues, the accelerator is almost the experiment. Indeed some of the questions require machines beyond our present capability. As this volume attests, there are parts of the particle physics program that have been significantly advanced without the use of accelerators such as the subject of neutrino oscillations and many aspects of the particle-cosmology interface. At this ...
A study was conducted under the auspices of the Coordinating Research Council, Inc. (CRC) to assess the potential effects of gasoline octane quality on vehicle acceleration performance. Twelve participating laboratories, representing both the oil and the automotive industries, tested a total of 182 vehicles as part of the 1989 CRC Octane Number Requirement Survey. The vehicles consisted of 78 with electronic knock control systems and 104 without. All testing was performed using the 1989/1990 CRC FBRU fuel series. The results showed that acceleration performance of vehicles with knock sensors was significantly affected by gasoline octane quality. Octane effects on acceleration performance were most pronounced at maximum-throttle (detent) conditions and at octane levels below the vehicles' octane requirements; however, some knock-sensor vehicles did show improved acceleration performance with ...
The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here.
This paper describes the results obtained from two large experimental facilities built at Sandia National Laboratories in Albuquerque, NM. FLAME (Flame Acceleration Measurements and Experiments) is a large horizontal rectangular channel designed to study flame acceleration, transition to detonation, simulation of combustion in containment geometries, component heating, and other problems in hydrogen combustion relevant to reactor safety. The Heated Detonation Tube has been designed to study detonations in hydrogen-air-steam mixtures. Both facilities have been in operation for just over a year. 12 figures.
This paper describes the results obtained from two large experimental facilities built at Sandia National Laboratories in Albuquerque, NM. FLAME (Flame Acceleration Measurements and Experiments) is a large horizontal rectangular channel designed to study flame acceleration, transition to detonation, simulation of combustion in containment geometries, component heating, and other problems in hydrogen combustion relevant to reactor safety. The Heated Detonation Tube has been designed to study detonations in hydrogen-air-steam mixtures. Both facilities have been in operation for just over a year. 12 figures.
Analytical and numerical calculations are presented for a reflexing electron beam type of collective ion accelerator. These results are then compared to those obtained through experiment. By constraining one free parameter to experimental conditions, the self-similar solution of the ion energy distribution agrees closely with the experimental distribution. Hence the reflexing beam model appears to be a valid model for explaining the experimental data. Simulation shows in addition to the agreement with the experimental ion distribution that synchronization between accelerated ions and electric field is phase unstable. This instability seems to further restrict the maximum ion energy to several times the electron energy.
A one parameter family of iterative methods for the simultaneous approximation of simple complex zeros of a polynomial, based on a cubically convergent Hansen-Patricks family, is studied. We show that the convergence of the basic family of the fourth order can be increased to five and six using Newtons and Halleys corrections, respectively. Since these corrections use the already calculated values, the computational efficiency of the accelerated methods is significantly increased. Further acceleration is achieved by applying the Gauss-Seidel approach (single-step mode). One of the most important problems in solving nonlinear equations, the construction of initial conditions which provide both the guaranteed and fast convergence, is considered for the proposed accelerated family. These cond...
and propels the projectile to a velocity sufficient to reach ..... CLF3 + N2 4 .... 5 inches or greater accelerates a finned projectile to the veloc ...
The superconducting Tevatron accelerator at Fermi National Accelerator Laboratory (Fermilab) has surpassed twenty years of operation. The Tevatron is still the highest energy particle accelerator in the world and will remain so until the commissioning of the LHC in Europe later this decade. The Tevatron has operated in a Fixed Target mode, accelerating a proton beam into stationary targets/detectors, as well as a Colliding Beam mode, continuously colliding counter rotating beams of protons and antiprotons. Upon completion, the Tevatron cryogenic system became the world's largest helium refrigeration system. In 1993, the Tevatron cryogenic system was given the designation of International Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers. The operational history, experiences and statistics of the Tevatron, with an emphasis on the cryogenic system, is ...
We study a two-level atom in interaction with a real massless scalar quantum field in a spacetime with a reflecting boundary. The presence of the boundary modifies the quantum fluctuations of the scalar field, which in turn modifies the radiative properties of atoms. We calculate the rate of change of the mean atomic energy of the atom for both inertial motion and uniform acceleration. It is found that the modifications induced by the presence of a boundary make the spontaneous radiation rate of an excited inertial atom oscillate near the boundary and this oscillatory behavior may offer a possible opportunity for experimental tests for geometrical (boundary) effects in flat spacetime. While for accelerated atoms, the transitions from ground states to excited states are found to be possible even in a vacuum due to changes in the vacuum fluctuations induced by both the presence of the boundary and the acceleration of atoms, ...
An almost linear optimization problem of importance in vibration isolation has been identified and algorithms were developed to minimize the forced vibrational response of structural systems. The constraints can be either displacements of accelerations. T...
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.
Particle accelerators are constructed and operated for a wide variety of applications. In particle physics - the branch of physics that studies the elementary constituents of matter and forces between them - high energy accelerators are used to look deep into the structure of matter. Medical particle accelerators are used for example in medicine to treat tumours [31], in imaging techniques such as Positron Emission Tomography (PET) [24], or for the radio-isotopes production. They also serve in many other industrial branches, e.g. geology, radiocarbon dating [39], molecular complex spectroscopy, lithography, food preservation etc. The eld of accelerator technology draws knowledge and expertise from a wide range of scientic disciplines and uses the latest technical knowledge. The incomplete list of covered disciplines includes mathematics, physics, electronics, computing, electromagnetic eld technology, ...
Modern day accelerator development encompasses a myriad technologies required for their diverse needs. Whereas RF, high voltage, vacuum, cryogenics etc., technologies meet their functional requirements, high finish lapping processes, ceramic-metal joining, oven brazing, spark erosion or wire cutting etc., are a must to meet their fabrication requirements. Electromagnetic (EM) forming technique falls in the latter category and is developed as a special technology. It is currently catering to the development as a nuclear reactor technology, but has the potential to meet accelerator requirements too. This paper highlights the general principle of its working, simple design guidelines, advantages, and suggests some specific areas where this could benefit accelerator technologies
A compact proton accelerator for medical applications is being developed at Lawrence Livermore National Laboratory. The accelerator architecture is based on the dielectric wall accelerator (DWA) concept. One critical area to consider is the switch region. Electric field simulations and thermal calculations of the switch area were performed to help determine the operating limits of rmed SiC switches. Different geometries were considered for the field simulation including the shape of the thin Indium solder meniscus between the electrodes and SiC. Electric field simulations were also utilized to demonstrate how the field stress could be reduced. Both transient and steady steady-state thermal simulations were analyzed to find the average power capability of the switches.
Mini-LIA is a miniature of a linear induction accelerator developed by China Academy of Engineering Physics and Tsinghua University in 2007. It has been constructed with a thermionic cathode in an electron injector and a metglas core in the induction accelerator cavities. A double-pulsed electron beam was produced for the first time in China on the Mini-LIA with a thermionic cathode in the electron gun and a metglas core in the induction accelerator cavities. A double-pulsed beam current of more than 1.1A was obtained on condition of 80 kV double-pulsed high voltage produced by pulsed power system supplying to the injector and accelerating modules. Some primary experiments for measuring the parameters of Mini-LIA has been performed, and some beam characterizations of Mini-LIA are presented. Further improvement is underway. (authors)
Government policies that encourage exploitation--in particular excessive logging and clearing for ranches and farms--are largely to blame for the accelerating destruction of tropical forests. This paper surveys the problem in detail and briefly recommends potential solutions.
FELs require tight control of the amplitudes and phase of the fields in two linear accelerator tanks to obtain stable lasing. The accelerator control loops must establish constant, stable, repeatable amplitudes and phases of the rf fields and must have excellent bandwidth to control high-frequency noise components. A model of the feedback loops has been developed that agrees well with measurements and allows easy substitution of components and circuits, thus reducing breadboarding requirements. The model permits both frequency and time-domain analysis. The accelerator control scheme and model are described and the control of noise in feedback loops is discussed, showing how low-frequency-noise components (errors) can be corrected, but high-frequency-noise components (errors) are actually amplified by the feedback circuit. Measurements of noise in both open- and closed-loop modes is shown and comparison is made with results ...
The next generation of particle accelerator is currently being designed at CERN. An understanding of the market forces in the computer industry will play a crucial role in the success of the project.
added to provide resistance to UV degradation, and vulcanization control. ...Sulphur is used to vulcanize the rubber ...additives and solvents age resistors, processing aids, accelerators, vulcanizing agents, softeners and fillers
This volume is based on the proceedings of the CERN Accelerator School's course on Applied Geodesy for Particle Accelerators held in April 1986. The purpose was to record and disseminate the knowledge gained in recent years on the geodesy of accelerators and other large systems. The latest methods for positioning equipment to sub-millimetric accuracy in deep underground tunnels several tens of kilometers long are described, as well as such sophisticated techniques as the Navstar Global Positioning System and the Terrameter. Automation of better known instruments such as the gyroscope and Distinvar is also treated along with the highly evolved treatment of components in a modern accelerator. Use of the methods described can be of great benefit in many areas of research and industrial geodesy such as surveying, nautical and aeronautical engineering, astronomical radio-interferometry, metrology of ...
magnet research at several national laboratories through its Advanced Accelerator Technology Program. The HEP Conductor Development Program, a collaboration among national...
An overview of different Ion Beam Analysis (IBA) techniques is given. Examples of applications of the PIXE techniques to various types of samples are presented. (author)
High salinity is one of the main factors limiting cotton growth and productivity. The genes that regulate salt stress in TM-1 upland cotton were monitored using microarray and real-time PCR (RT-PCR) with samples taken from roots. Microarray analysis showed that 1503 probe sets were up-regulated and 1490 probe sets were down-regulated in plants exposed for 3h to 100mM NaCl, and RT-PCR analysis validated 42 relevant/related genes. The distribution of enriched gene ontology terms showed such important processes as the response to water stress and pathways of hormone metabolism and signal transduction were induced by the NaCl treatment. Some key regulatory gene families involved in abiotic and biotic sources of stress such as WRKY, ERF, and JAZ were differentially expressed. Our transcriptome analysis might provide some useful insights into salt-mediated signal transduction pathways in cotton and offer a number of candidate genes as potential ...
A statistical method is developed to determine the locations of major pollutant sources affecting a distant downwind receptor, provided that air trajectories can be estimated. Probability density functions are estimated which indicate the overall residence time of air parcels over a given geographic region as they travel toward a receptor and residence time for the case of high pollutant concentrations at the receptor. These functions are used to estimate a conditional probability function which indicates the potential for a source region to contribute to high air pollution concentrations. Finally, a source contribution function is formulated to indicate the relative contribution of different source regions to high concentrations at the receptor. The method is tested using data collected at Grand Canyon National Park in 1980. The dominant pathway for air masses arriving at Grand Canyon during this period was southern California. A lesser ...
Operations at the Savannah River Site (SRS) result in releases of small amounts of radioactive materials to the atmosphere and to the Savannah River. For regulatory compliance purposes, potential offsite radiological doses are estimated annually using computer models that follow U.S. Nuclear Regulatory Commission (NRC) Regulatory Guides. Within the regulatory guides, default values are provided for many of the dose model parameters but the use of site-specific values by the applicant is encouraged. A detailed survey of land and water use parameters was conducted in 1991 and is being updated here. These parameters include local characteristics of meat, milk and vegetable production; river recreational activities; and meat, milk and vegetable consumption rates as well as other human usage parameters required in the SRS dosimetry models. In addition, the preferred elemental bioaccumulation factors and transfer factors to be used in human health exposure calculations at SRS are documented. ...
The C isotopic composition of CH4 emissions are strongly influenced by the pathway of CH4 formation. Contrary to data from other freshwater systems, soil gas and surface flux measurements made in the tropical rain forests of Puerto Rico strongly suggest that CH4 produced in these environments was derived from CO2 reduction, rather than from acetate consumption. This study explored the effects of bacterial competition for acetate, pH, and soil structure on the pathways of CH4 formation in tropical rain forest soils. Our goal was to test two principal hypotheses: (1) ferric iron-reducing bacteria out-competed methanogens for acetate, resulting in greater CO2 reduction rather than aceticlastic methanogenesis, and (2) the low pH of tropical rain forest soils favors CO2 reduction rather than aceticlastic methanogenesis. In addition, this study also investigated the effect of destroying soil aggregate structure on the pathways ...
In order to simplify the coke manufacturing process, a coke production mechanism in coal pyrolysis was discussed. Australian bituminous coal which can produce good coke was used for the discussion. At a temperature raising rate of 50{degree}C per minute, coal weight loss increases monotonously. However, in the case of 3{degree}C, the weight loss reaches a peak at a maximum ultimate temperature of about 550{degree}C. The reaction mechanism varies with the temperature raising rates, and in the case of 50{degree}C per minute, volatiles other than CO2 and propane increased. Weight loss of coal at 3{degree}C per minute was caused mainly by methane production at 550{degree}C or lower. When the temperature is raised to 600{degree}C, tar and CO2 increased, and so did the weight loss. Anisotropy was discerned in almost of all coke particles at 450{degree}C, and the anisotropy became remarkable with increase in the maximum ultimate temperature. Coke and ...
The ultimate compressive strength and modulus of elasticity of femoral cortical bone from adult geese (Anser anser), were determined by sex and by quadrant by compressing small right circular cylinders which were 2.4 mm in height and 0.8 mm in diameter. The average ultimate compressive strength was 183 +/- 29 MPa. The average modulus of elasticity was 13.2 +/- 3.4 GPa. The bending strength and bending modulus of elasticity were determined by a three point bend test on rectangular prisms which had the approximate dimensions 0.75 mm X 0.75 mm X 25 mm. The average bending strength was 263 +/- 44 MPa while the average bending modulus was 19.6 +/- 3.1 GPa. The calcium content was determined by atomic absorption spectrophotometry and no correlation was found with the mechanical properties. The histology of the cortical bone was examined both quantitatively and qualitatively. A unique type of Haversian bone is described. Goose bone was found to be ...
Results from ultimate analysis, proximate and petrographic analyses of a wide range of Kentucky coal samples were used to predict coal rank parameters (vitrinite maximum reflectance (R{sub max}) and gross calorific value (GCV)) using multivariable regression and artificial neural network (ANN) methods. Volatile matter, carbon, total sulfur, hydrogen and oxygen were used to predict both R{sub max} and GCV by regression and ANN. Multivariable regression equations to predict R{sub max} and GCV showed R{sup 2} = 0.77 and 0.69, respectively. Results from the ANN method with a 2-5-4-2 arrangement that simultaneously predicts GCV and R{sub max} showed R{sup 2} values of 0.84 and 0.90, respectively, for an independent test data set. The artificial neural network method can be appropriately used to predict R{sub max} and GCV when regression results do not have high accuracy. (author)
Relationships of ultimate and proximate analysis of 4540 US coal samples from 25 states with gross calorific value (GCV) have been investigated by regression and artificial neural networks (ANNs) methods. Three set of inputs: (a) volatile matter, ash and moisture (b) C, H, N, O, S and ash (c) C, H{sub exclusive} {sub of} {sub moisture}, N, O{sub exclusive} {sub of} {sub moisture}, S, moisture and ash were used for the prediction of GCV by regression and ANNs. The multivariable regression studies have shown that the model (c) is the most suitable estimator of GCV. Running of the best arranged ANNs structures for the models (a) to (c) and assessment of errors have shown that the ANNs are not better or much different from regression, as a common and understood technique, in the prediction of uncomplicated relationships between proximate and ultimate analysis and coal GCV. (author)
The effects of key metallurgical variables on the low fluence hardening in a set of A533B model steels were evaluated over a wide range of irradiation temperatures. Above about 163 degrees C hardening increased with higher copper and nickel contents, as is typical of the pressure vessel operating regime around 290 degrees C. However, at 121 degrees C the hardening was generally lower and unaffected by copper and nickel variations. This observation of decreased hardening with lower temperature (e.g. an open-quotes invertedclose quotes temperature dependence) is tentatively attributed to a reduced contribution of copper precipitation. Tensile data for a set of commercial steels with a range of (uncontrolled) compositions also showed minimal sensitivity to copper variations at 121 degrees C. Unlike the hardness data no systematic reductions in the yield stress increases were observed between 163 and 121 degrees C. However, the ultimate tensile strength did decrease at ...
ObjectivesThe aim of this study was to evaluate the relationship between micro-tensile bond strength (mTBS) and ultimate tensile strength (UTS) of resin composite restorations in cavities filled by a bulk or incremental technique using the micro-tensile test.MethodsClass I cavities (4mm long, 3mm wide, 3mm deep) were prepared into dentine of sixteen human molars. All cavities were bonded with Clearfil SE Bond and restored with AP-X composite with either a bulk or incremental technique. After storage in water for 24h, the teeth were vertically sectioned to yield two slabs. Each slab was sectioned into three sticks. Sticks of one slab were trimmed into an hourglass of 0.7mm2 area at resin-dentine interface for bond strength measurement while the other sticks were trimmed at the centre of the...
Photosynthetic carbohydrates from the leaves are exported through the phloem to growing tips, roots, flowers and fruits. If sucrose labelled with {sup 14}C is applied to the leaves of bean plants, the pathway for sugar movement may be readily observed by autoradiography. Students apply the labelled sucrose during class time and return the next day to press their plants. During the next class, the pressed and dried plants are placed against X-ray film and left in the dark for four weeks. the film is then developed, examined for presence of label and compared to the pressed plants. Source to sink movement is clearly illustrated and information about the mechanism of phloem transport and loading is gained through experimental treatments, which include blocking the phloem pathway and inhibiting energy production.
Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the elderly accounting for the vast majority of dementia. Recently, many studies have implicated the role of inflammatory response, especially neuroinflammatory response in the development and progression of AD. However, the underlying mechanism of how inflammatory response induces AD is unknown. Kynurenine pathway is a major route of the amino acid tryptophan catabolism, resulting in the production of nicotine adenine dinucleotide and other neuroactive intermediates: quinolinic acid (QA) and kynurenic acid (KA). QA exerts different toxic effects, including over-activation of N-methyl-d-aspartate (NMDA) receptor and excitotoxicity, synaptic dysfunction and neuronal death. On the other hand, KA is identified as the only...
Background and purpose: The aims of this study were to investigate the anti-cancer activity of SZ-685C, an anthracycline analogue isolated from marine-derived mangrove endophytic fungi, and to explore the molecular mechanisms underlying such activity. Experimental approach: The effect of SZ-685C on the viability of cancer cell lines was investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. SZ-685C-induced apoptosis was assessed by Annexin V-fluorescein isothiocyanate/propidium iodide staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling assay and analysis of caspase activation. The effect of SZ-685C on the Akt/FOXO pathway was studied using Western blotting analysis, and the in vivo anti-tumour efficacy was examined in ...
The pore structure of volcanic clasts is examined using measurements of porosity, permeability, and electrical properties. Permeability varies by several orders of magnitude among volcanic clasts and does not depend solely upon porosity. Electrical property measurements of saturated volcanic samples illustrate the influence of pathway tortuosity and pore shape on permeability. For equivalent eruption conditions, silicic samples show higher tortuosities, smaller vesicle sizes, and lower permeabilities than mafic samples. These differences are largely due to variations in vesiculation and crystallization history. Differences between explosive and effusive samples reflect the relative ability of bubbles to form and maintain connected pathways during bubble expansion and collapse. Isotropic sa...
This issue of Carbon Market Perspectives on 'Pathways for implementing REDD+: Experience from carbon markets and communities' discusses the role of carbon markets in scaling up investments for REDD+ in developing countries. Nine articles authored by experienced negotiators on REDD+, carbon market actors, project developers and other leading experts share experiences and make suggestions on the key elements of a future international REDD+ regime: Architecture and underlying principles, measuring, reporting and verification (MRV), private-sector involvement, the rights of indigenous people and local communities, biodiversity conservation and environmental integrity. The articles are grouped under three main topics: the lessons of existing REDD+ projects; the future REDD+ regime and the role of carbon markets; and experiences and ideas about the involvement of indigenous people and local communities. (LN)
This paper reviews the molecular biology of the renin-angiotensin system. The renin gene structure is analyzed in detail, including an examination of the putative regulatory regions. The combined action of these regulatory sequences would result in the complex, tissue-specific expression and regulation observed in vivo. The expression of the tissue renin-angiotensin systems, which may have important physiological functions, is also described. In addition, the pathway of renin biosynthesis and secretion is reviewed. This includes speculation on the fate of circulating prorenin and the physiological role of multiple renin forms and secretory pathways. The molecular approaches described in this paper have greatly advanced our knowledge of the biology of the renin-angiotensin system. Future studies using these and other approaches should provide further insight into this complex system.
Current studies in plants suggest that the content of the coenzyme NAD is variable and potentially important in determining cell fate. In cases that implicate NAD consumption, re-synthesis must occur to maintain dinucleotide pools. Despite information on the pathways involved in NAD synthesis in plants, the existence of a mitochondrial nicotinamide mononucleotide adenylyltransferase (NMNAT) activity which catalyses NAD synthesis from nicotinamide mononucleotide (NMN) and ATP has not been reported. To verify the latter assumed pathway, experiments with purified and bioenergetically active mitochondria prepared from tubers of Jerusalem artichoke (Helianthus tuberosus L.) were performed. To determine whether NAD biosynthesis might occur, NMN was added to Jerusalem artichoke mitochondria (JAM)...
Many existing agents for diabetes therapy are unable to restore or maintain normal glucose homeostasis or prevent the eventual emergence of hyperglycemia-related complication. Therefore, agents based on novel mechanisms are sought to complement and extend the current therapeutic approaches. Based on the initial paper research, we focused on active STAT3 as an attractive pharmacological target for type 2 diabetes. The subsequent text mining with a unique query to identify suppressors but not activators of STAT3 revealed the ERK2/STAT3 pathway as a novel diabetes target. The description of ERK2 inhibitors as diabetes target had not been found in our text mining research at present. The mechanism-based peptide inhibitor for ERK2 was identified using the knowledge of the KIM sequence, which ha...
In three calves experimentally infected with Trypanosoma congolense the amounts of IgG1 and IgG2 were little changed and similar to those of normal animals. IgM increased in amount early in the infection and the amount of the increase appeared related to the parasite burden. The amounts of IgA and IgE were both much decreased and this also appeared related to the numbers of parasites in the blood. There was a decrease in the amounts of total haemolytic complement and complement components C1, C1q and C3 in the infected calves. Furthermore the amounts of properdin fluctuated with the cyclical changes in numbers of T. congolense parasites in the individual calves. No significant change in the amount of C8 was observed. It is considered that activation of both the alternative and the classical complement pathways occurs in trypanosome infected animals but that neither pathway goes to its terminal stages.
2-methylpropan-1-ol (isobutanol) is a leading candidate biofuel for the replacement or supplementation of current fossil fuels. Recent work has demonstrated glucose to isobutanol conversion through a modified amino acid pathway in a recombinant organism. Although anaerobic conditions are required for an economically competitive process, only aerobic isobutanol production has been feasible due to an imbalance in cofactor utilization. Two of the pathway enzymes, ketol-acid reductoisomerase and alcohol dehydrogenase, require nicotinamide dinucleotide phosphate (NADPH); glycolysis, however, produces only nicotinamide dinucleotide (NADH). Here, we compare two solutions to this imbalance problem: (1) over-expression of pyridine nucleotide transhydrogenase PntAB and (2) construction of an NADH-de...
It is uncertain if downregulation of ?-adrenoceptor signaling pathway is promoted by an enhanced adrenergic tone at an early stage of cardiac disease, or it develops secondary to detrimental local myocardial changes in advanced heart failure. We examined the integrity of ?-adrenoceptor signaling pathway upon chronic infusion of isoproterenol, a ?-adrenoceptor agonist, at a dose producing no structural left ventricular (LV) remodeling and systolic dysfunction. Subcutaneous isoproterenol infusion (400??g?kg?1?h?1 over 16?days) to guinea pigs using osmotic minipumps produced no change in cardiac weights, LV internal dimensions, myocyte cross-sectional area, extent of interstitial fibrosis, and basal contractile function. Isolated, perfused heart preparations from isoproterenol-treated guinea ...
Summary Background Sorafenib is an oral multikinase inhibitor that blocks cell proliferation via the ERK pathway and angiogenesis via the VEGF pathway. This phase II trial was conducted to determine the efficacy and tolerability of sorafenib for the treatment of patients with metastatic urothelial cancer (UC) who had not had prior chemotherapy for advanced disease. Patients and Methods Seventeen chemo-na?ve UC patients with adequate performance status and organ function were treated with sorafenib 400?mg twice daily on a continuous basis until progression or unacceptable toxicity. The primary endpoint was objective tumor response rate as measured by RECIST criteria. Secondary endpoints included rate of prolonged stable disease (>3?months), time to progression, median and 1?yr survival and ...
Objective: To establish a computer program for rapid calculation of internal committed effective close through inhalation and ingestion pathways under radiological emergency. Methods: Visual Basic 6.0 is used to compile the generic procedures of internal committed effective dose by inhalation and ingestion in IAEA-TECDOC-1162, Generic Procedures for Assessment and Response during a Radiological Emergency. Results: The assessment methodology of internal committed effective dose by inhalation and ingestion under radiological emergency in the report IAEA-TECDOC-1162 can be coded into a computer program. Conclusions: This research provides a rapid method of assessment for internal committed effective dose by inhalation and ingestion under radiological emergency, and it may provide needed dosimetry data for treatment under emergency response. (authors)
A range of 6-substituted imidazo[1,2-a]pyridines were synthesized using a multicomponent coupling reaction. Most of these compounds were found to exhibit excellent activity against the colon cancer cell lines HT-29 and Caco-2, whilst not showing significant toxicity against white blood cells. Our studies have shown that the proteolytic phase of apoptosis was initiated 2 h after treatment with these imidazo-[1,2-a]pyridines. The data suggests that the imidazo[1,2-a]pyridine-induced cell death in HT-29 and Caco-2 cells is mediated via pathway(s) that include the release of cytochrome c from the mitochondria to the cytosol and the activation of caspase 3 and caspase 8.
A detection theory is developed for point-contact metal-oxide-metal (MOM) systems. A system with heterogeneous oxide strongly bonded to the substrate is considered. It is shown that the form of the functional connection between the barrier heights and the ultimate compressive strength of the oxide has no substantial influence on the voltage-current characteristics of the system. Quantitative analysis indicates that a MOM system can behave as a tunnel diode and as a diode with a Schottky barrier. The model permits the determination of the optimum construction of long-life detectors based on MOM point-contacts.-
The bone mineral areal content and the ultimate compressive strength were determined in 109 lumbar vertebrae from 36 subjects. The bone mineral areal content was related to the number, shape, and localization of the Schmorl's nodes detected in the x-rayed and sectioned vertebral bodies. One type of node, irregular in shape and localization, occurred only in the vertebrae with low bone mineral areal content values and thus in vertebrae with relatively low compressive strength. A second type of Schmorl's nodes, regular in shape and localization, did not reflect any general weakness of the vertebral bodies. PMID:6623194
Strain rate effects for the high strength, metastable beta-titanium alloy Ti-8Mo-8V-2Fe-3Al are assessed in terms of tensile and fracture toughness behavior. It is shown that as the strain rate increases the yield strength, ultimate tensile strength, and ductility also increase. As a result of the decrease in the amount of intergranular fracture as the strain rate is increased, the dynamic fracture toughness values K/sub Id/ are greater than those obtained under static conditions as given by K/sub Q/.
The ultimate compressive strength of 36 thoracolumbar vertebrae was determined experimentally. In addition, the trabecular bone mineral content was measured by single energy quantitative computed tomography. The areas of fractured endplates were also determined by computed tomography. The results show that a linear relationship exists between the compressive strength and the product of bone density and endplate area. These data allow an in vivo prediction of vertebral body strength using a noninvasive method with a standard error of estimate amounting to less than 0.95 kN. PMID:3212488
The 'elementary' particle physics began in 1935, when Hideki Yukawa published his pioneering pi-meson theory, and the problem of strong interaction was finally solved 40 years later by the establishment of the Standard Model. The composite models of hadrons by the Sakata school and Sin-itiro Tomonaga's renormalization theory for quantum electrodynamics played essential roles for finding this beautiful solution. It is really surprising that it took only 40 years to solve such desperately difficult problem. The 'elementary' particle physics then split into two new fields, quark-hadron physics' and 'unified (ultimate) theory of particle physics', which are now 30 years old already. (author)
The viability of osteocytes can be demonstrated in sawn decalcified sections of bone by their lactate dehydrogenase activity. In the cancellous bone of the femoral head, the proportion of lacunae containing viable osteocytes decreased from 88 +/- 7% (mean +/- SD) at 10-29 years to 58 +/- 12% (P Ultimate compressive strength did not correlate with osteocyte viability. In the femoral head there is gradual, age-related reduction in osteocyte viability that can be more pronounced in hip fracture. Osteocyte death may affect bone quality by impairing repair of fatigue damage. PMID:8275364
In source coding, either with or without side information at the decoder, the ultimate performance can be achieved by means of random binning. Structured binning into cosets of performing channel codes has been successfully employed in practical applications. In this letter it is formally shown that various convolutional- and turbo-syndrome decoding algorithms proposed in literature lead in fact to the same estimate. An equivalent implementation is also delineated by directly tackling syndrome decoding as a maximum a posteriori probability problem and solving it by means of iterative message-passing. This solution takes advantage of the exact same structures and algorithms used by the conventional channel decoder for the code according to which the syndrome is formed.
Some results on mechanical property study of copper and titanium subjected to impact load and next to neutron irradiation are presented. It was shown that shock wave influence involves a substantial shape change of the stress-strain diagram and of respective mechanical characteristics. Yield- and ultimate strength were substantially increased, as well as hardness with a considerable drop of plasticity. Also a heat stability of copper and titanium specimens was studied after being treated with shock-waves and neutron radiation. Results are given of electron microscope study of titanium structure sfter explosion hardening, which caused decomposition of hydride segregations in titanium and increased dislocation density.
Typhoons Aere (2004) and Matsa (2005) caused high nephelometric turbidity in the Shihmen reservoir in northern Taiwan, jeopardizing the operation of the reservoir for several days, and ultimately impacting the living conditions and economy of the downstream residents. The torrential rains caused landslides and debris flows in upland areas, and flowed into riverbeds, likely contributing significantly to the suspended sediment yields in the reservoir. This investigation elucidates how upland landslides affect sediment attributes in the reservoir basin. Study methods including field observations, spatial analysis in GIS and aerial photo interpretation are adopted to trace the sediment sources and contributing factors to the landslide. Torrential rains induced landslides and debris-flows uplan...
The transfer of fish from field to laboratory facilities or their propagation in closed or restricted systems frequently results in bacterial infection and ultimately large-scale mortality. In attemps to alleviate this problem, we have added tetracycline hydrochloride to the water prophylactically (pretreating tanks before wild fish were added) and therapeutically (treating tanks after bacterial outbreaks were detected.) In the present study, we examined the effect of tetracyline hydrochloride on the critical thermal maximum (CTM) of the common shiner (Notropis cornutus).
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.
This essay, operating in a philosophical mode, continues and expands the discussion initiated by Amos Yong about the role of "spirit" in the theology-science dialogue. After a working definition, it explores Santayana's and Tillich's perspectives on the proximate derivation of human spirit before treating them further as representatives for naturalist and trans-naturalist camps regarding the spirit's ultimate source. Then a descriptive definition of "spirit" is advanced along with the concluding standpoint that while "spirit" is vague, even poetic, it remains for the foreseeable future a necessary and useful placeholder for what advances in neuroscience and future philosophical and theological research can help us unveil further.
Due mainly to competitive pressures, the practice of offering electric and telephone service under contracts or special tariffs negotiated individually between a utility and its customers has increased in importance in recent years. Moreover, the practice is likely to become still more widespread in the future. This creates questions of public policy that are of interest to regulators and ratepayers alike such as how to supervise the practice, how to encourage utilities to compete while preventing cross-subsidization and anticompetitive behavior, and how the practice will ultimately affect utilities and ratepayers. This report sheds light on the topic by describing approaches that have been taken by the various regulatory commissions and by providing a framework for analyzing such contractors.
Marburg virus belongs to the genus Marburgvirus in the family Filoviridae and causes a severe hemorrhagic fever, known as Marburg hemorrhagic fever (MHF), in both humans and nonhuman primates. Similar to the more widely known Ebola hemorrhagic fever, MHF is characterized by systemic viral replication, immunosuppression and abnormal inflammatory responses. These pathological features of the disease contribute to a number of systemic dysfunctions including hemorrhages, edema, coagulation abnormalities and, ultimately, multiorgan failure and shock, often resulting in death. A detailed understanding of the pathological processes that lead to this devastating disease remains elusive, a fact that contributes to the lack of licensed vaccines or effective therapeutics. This article will review the...
The theoretical alignment limit for focused ion beam (FIB) implantation was deduced from the calculated resolution for the detection of an alignment mark. The alignment resolution varies with the signal to noise ratio and there is an optimum current which gives the best resolution. The alignment resolution epsilon/sub sigma/ is approximately 0.006 ..mu..m for a 160 keV Si/sup ++/ beam from our FIB implanter. The measured alignment error is approximately 0.06 ..mu..m and the main reason of this discrepancy is vibration. The ultimate limit on the alignment error can be reached through improvements in the implanter system.
The Kootenay, Luscar/Manville, and Belly River Groups, and the Horseshoe Canyon and Scollard Coalspur Formations are the most important coal measures in Alberta. Estimated current resources and reserves are 89 and 35 billion tonnes, respectively. Ultimate resources and reserves are 2100 and 660 billion tonnes, respectively. Most of the reserves are subbituminous and require underground mining methods. Current production is approximately 39 million tonnes per year, primarily subbituminous coal that is used for domestic electrical generation. Bituminous coal is exported. Long-term development will depend on markets, price, and infrastructure. 11 refs., 4 figs.
The report is the second of three describing the geology of coal quality variations in the foothills and mountains region of Alberta. The Lower Cretaceous Luscar Group, Lower Paleocene Coalspur Formation, and the Upper Paleocene Paskapoo Formation (Obed-Marsh coal zone, which is classified as a foothills deposit) are evaluated. Data on proximate and ultimate analysis variables, calorific analysis, vitrinite reflectance, maceral analyses, and coal quality relationships are presented. The coals range from low volatile bituminous to subbituminous A. Regional and local in seam coal quality variations are examined. 49 refs., 39 figs., 6 tabs.
The Minami-Iwaki trunk line now under construction by Tokyo Electric Power Company is an UHV transmission line which covers 130km from the central region of the Abukuma highlands, Fukushima Prefecture, through the northern ridge of the Kanto Plain to Imaichi City, Tochigi Prefecture and has 235 steel towers. About 30% of the ground along the above route is mainly layers of sand and gravel. Accordingly it has become urgent to design rationally the pile foundations in the sand and gravel layers. Hence the company has studied an estimation method of the ultimate bearing power of cast-in-place piles penetrating the sand and gravel layers and the displacement of pile heads. In this report, the result of the above study is described. The company has so far used the equations in accordance to the Meyerhof equations for the estimations of the ultimate bearing power and this time, this equations have been examined for its application to the sand and ...
The reconstruction of segmental defect in long bone is a clinical challenge. Multiple surgeries are typically required to restore the structure and function of the affected defect site. In order to overcome this defect a biodegradable bone tissue engineering scaffold is used. This scaffold acts as a carrier of proteins and growth factors, while also supporting the load that the bone would normally sustain, until the natural bone can regenerate in its place. Work was done to optimize an existing solid free-form scaffold design. The goal of the optimization was to increase the porosity of the scaffold while maintaining the strength of a previously-tested prototype design. With this in mind, eight new designs were created. These designs were drawn using CAD software and then through the use of finite element analysis the theoretical ultimate compressive strength of each design was obtained. Each scaffold design was constructed by casting a thermal-curable ...
This paper extends the development of a new formulation of the theory of tachyons to encompass the dynamics of tachyons. Energy and momentum are discussed along with the proper mass of a tachyon. The transformation of force in extended relativity (ER) is derived. Acceleration in ER is also discussed, as well as the relationship between force and acceleration. Two simple examples relating to the motion of a charged tachyon are discussed, followed by a brief explanation of why tachyons cannot emit Cerenkov radiation in a vacuum. 13 refs., 3 figs.
Neutral beam systems for the next generation of magnetic fusion devices will be based on negative ions. Development are progressing steadily, and large negative ion-based systems are prepared for JT60-U and LHD, and are being considered for ITER. An overview of the physics of the production, acceleration and neutralization of large negative ion beams is given. the present state of the art in Research and Development is also surveyed. (author). 55 refs., 10 figs., 1 tab.
Neutral beam systems for the next generation of magnetic fusion devices will be based on negative ions. Developments are progressing steadily, and large negative ion-based systems are under preparation for JT60-U and LHD, and are being considered for ITER. An overview of the physics of the production, acceleration and neutralization of large negative ion beams is given. The present state of the art in R and D is also surveyed. (Author).
Lawrence Livermore National Laboratory (LLNL) has implemented a computer control system for operation of an FN tandem accelerator. The control software utilized is the Thaumaturgic Automated Control Logic (TACL) written by the Continuous Electron Beam Accelerator Facility and co-developed with LLNL. Details of the design philosophy, hardware configuration, control software, and special control algorithms will be presented. 2 refs., 4 figs.
The salient features of the near-infrared free-electron laser (FEL) that is under construction at the new Darmstadt superconducting 130-MeV electron accelerator are discussed. Special attention is given to the layout and the parameters of the accelerator, the layout of the planned FEL experiment, the characteristics of the electron gun, the subharmonic chopper-buncher system, and the hybrid undulator system of the Darmstadt FEL. A comparison of the planned Darmstadt FEL with conventional lasers, with respect to the pulse and wavelength region, is presented. 15 refs.
The motion of an accelerated charge in a vacuum is analyzed, via the superposition principle and Fourier analysis, into uniform-motion components, which include bradyonic as well as tachyonic contributions. It is shown that the former contribute only to the induction fields whereas the latter are the source of the radiation emitted by the charge, via the Sommerfeld-Cerenkov mechanism. This result calls for a reexamination of some recently formulated theories of superluminal particles.
The structure of the P-2, S-1 accelerator mode with one step, S-1, on double period, P-2 for systems, described by the Harper mapping as well as by standard mapping, is analyzed. Detailed analysis of stability criteria is given and comparison with the results of numerical analysis is performed. Three-period compression of the P-2, S-1 island is revealed in the standard mapping. Refs. 7, figs. 7.
Modern particle accelerators offer new opportunities to dramatically reshape the way we think about nuclear energy, and challenge some of the thorniest problems linked to its industrial use, e.g. nuclear waste. A powerful proton accelerator driving a sub-critical fission reactor could be used for producing energy more safely and burning up the extra spent fuel which so far has been stored in geological repositories.
High energy muon colliders, such as the TeV-scale conceptual designs now being considered, are found to produce enough high energy neutrinos to constitute a potentially serious off-site radiation hazard in the neighbourhood of the accelerator site. A general characterization of this radiation hazard is given, followed by an order-of-magnitude calculation for the off-site annual radiation dose and a discussion of accelerator design and site selection strategies to minimize the radiation hazard.
We report acceleration of electrons moving in free space near an active Nd:YAG slab. The power of a non-relativistic beam of electrons has increased by more than 30% when the medium was excited. It is demonstrated experimentally that the energy gained by the electrons is linearly proportional to the energy stored in the medium. Moreover, the energy gain traces closely the population inversion inferred by monitoring the spontaneous radiation.
This paper describes the conversion from an existing production control computer, an SEL 840, to a DEC VAX 11/780. The plan is to add a layer of hardware to accomplish a smooth and gradual transition from the 840 to the VAX while leaving the underlying equipment unchanged. The architecture of the control system software is discussed for a large linear accelerator from the standpoint of its requirements and the particular design philosophy chosen.
Two accelerated aging test procedures are proposed for use on solid dielectric extruded distribution cables under wet conditions. One test method is a fixed time duration test in which the degree of cable specimen aging is assessed in terms of breakdown tests, while the other test method is a time to breakdown test in which the cable specimens are voltage stressed until failure ensues.
This annual report describes research activities which have been performed with the JAERI tandem accelerator and the Van de Graaff accelerator from April 1, 2000 to March 31, 2001. Summary reports of 46 papers, and lists of publication, personnel and cooperative research with universities are contained. (author)
Free-electron-laser (FEL) oscillators require a train of high-brightness bunches. Conventional subharmonic bunchers are currently used with rf linacs to generate pulse trains, but the resulting dilution of the transverse phase space and lower beam brightness are unacceptable for high-performance FELs. Recent developments suggest that photoemitters of high quantum efficiency combined with rapid acceleration can produce pulse trains of higher brightness than has been achieved before.
Accelerated aging tests such as high temperature burn-in, which are in current use on Bendix Kansas City Division's (BKC) purchased small and medium scale integrated circuits, were evaluated to determine if they are effective and necessary to ensure the required reliability. A theoretical analysis, a literature search, and a study of lot acceptance results were used to assess the value of integrated circuit burn-in.
Present-day requirements for radiotherapy equipment are considered. The recently developed linacs of LUE-5, LUE-25, LUE-15MM models, as well as a newly designed unified series of medical linacs of LUER-5M, LUER-20M, LUER-40M models are described in brief. The main scientific and technical problems that were solved during their construction, namely, development of accelerating structures, a radiation head, dosimetry equipment, a programming unit, a magnetic mirror etc. are described.
Characterization of the electron beam's properties will be a major task after the upgrade of the Los Alamos Free-Electron Laser (FEL) Facility with a photoelectric injector (PEI) and increased acceleration capability to 40 MeV. Adjustments to the previous diagnostics package that address the lower beam emittance, higher energy, and wakefield source reduction issues will be discussed. 6 refs., 8 figs., 1 tab.
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
This paper describes the problems and solutions in using 18 MeV linear accelerator, with minimum 6 MeV electron capability, for total skin irradiation for mycosis fungoides. The 6 MeV electron energy...Full Text Available
Using an anti-receptor mAb that blocks the attachment of echovirus 7 and related viruses (echoviruses 13, 21, 29 and 33), we have isolated a complementary DNA clone that encodes the human decay-accelerating...Full Text Available
Accelerators can not be improved without the development of adequate beam instruments and diagnostic tools. This year this statement is particularly right: a lot of contributions are dedicated to beam monitoring and to the design of new beam monitors based on original technologies. This document gathers about 100 contributions.
We argue that the occurrence of late-time acceleration can conveniently be described by first-order general relativity covariantly coupled to fermions. Dark energy arises as a gravitationally driven BCS condensate of fermions which forms in the early universe. At late times, the gap and chemical potential evolve to have an equation of state with effective negative pressure, thus naturally leading to acceleration.
The contribution of pulsar accelerated nuclei to the cosmic rays inside the Galaxy is calculated assuming that a significant part of the pulsar rotational energy is lost on acceleration of iron nuclei extracted from the surface of the neutron star. Different models of the galactic pulsar population are discussed. It is shown that the best description of the observed cosmic ray spectrum and the mass composition between a few 10{sup 15} eV and a few 10{sup 18} eV is obtained for the model B of Lorimer et al. (1993)
The accelerating flow of a lighter continuous phase through a heavier one is considered. Small nonuniformities grow into large ones due to the Rayleigh-Taylor instability. An experiment exemplifying the large bubble formation due to Rayleigh-Taylor instability was performed and simulated using the PHOENICS 84 computer code. The same numerical procedure was applied to the two-phase flow in a gun barrel. It shows that the acceleration provided by the movement of the projectile can cause initial nonuniformities to grow with time.
Proceeding from analysis of the influence of parameters of the target-filter system on radiation-physical characteristics of braking radiation, some recommendations were issued for assessment of the forming systems of medical accelerators of electrons. A new criterion - a coefficient of the forming system efficacy - was introduced, characterizing a beam formation tract with relation to a whole set of radiotherapeutic problems.
A bibliography is presented of unclassified published and in-house technical material written by members of the Accelerator Technology Division, Los Alamos National Laboratory, since its inception in January, 1978. The author and subject concordances in this report provide cross-reference to detailed citations kept in a computer database and a microfilm file of the documents. The citations include an abstract and other notes, and can be searched for key words and phrases.
Recent experiments have explored the use of a free-electron laser (FEL) as a buncher for a microwave two-beam accelerator, and the subsequent driving of a standing-wave rf output cavity. Here the authors present a deeper analysis of the longitudinal dynamics of the electron bunches as they are transported from the end of the FEL and through the output cavity. In particular, the authors examine the effect of the transport region and cavity aperture to filter the bunched portion of the beam.
An S-brane solution with two non-composite electric branes and a set of l scalar fields is considered. The intersection rule for branes corresponds to the Lie algebra A_2. The solution contains five factor spaces with the fifth one interpreted as ``our'' 3-dimensional space. It is shown that there exists a time interval where accelerating expansion of ``our'' 3-dimensional space is compatible with small enough value of effective gravitational ``constant'' variation.
There are several on-going projects of e{sup +}e{sup -} colliders. If they are constructed, we can convert them into photon-photon ({gamma}-{gamma}) colliders by converting electron beams into {gamma} beams, irradiating laser beams just before the interaction point. In this report we discuss the technical issues on the accelerator.
The applicability of Broyden's second method for accelerating the convergence of self-consistent electronic-structure calculations based on the linearized augmented-plane-wave method is discussed in terms of a W(001) surface calculation. It is found that its use results in a significant improvement in the convergence of the calculation, and based on this it is concluded that its use should increase the size of the systems for which such calculations are feasible.
The author discusses the accelerated aging tests performed using Hondo and Maya as aging resids with a commercial large pore hydrotreating catalyst. The results from these tests were compared with those obtained under a normal full life test. The test resid was a sample of a typical refinery charge and the activities for sulfur and vanadium removal were determined at 720"0F after successive brief periods of exposure to the heavier oils.
Safety-related instrument in nuclear power plants must be checked for reliability over their projected operating life. A method of conducting accelerated aging tests is presentd. It uses the Arrhenius activation energy concept and manipulation of the parameters of the test e.g. by raising test temperature, by relying on a model characterizing the chemical-related reactions of materials.
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 ...
Multi-beamlet focusing of an intense negative ion beam has been performed using the beamlet steering by the aperture displacement. The apertures of the grounded grid were displaced as all beamlets of 270 (18 x 15) in the area of 25 cm x 26 cm would be steered to a common point (a focal point) in both the two-stage and the single-stage accelerators. The multi-beamlets were successfully focused and the e-folding half width of 10 cm was achieved 11.2 m downstream from the ion source in both the accelerators. The corresponding gross divergence angle is 9 mrad. The negative ion beamlets are deflected by the magnetic field for the electron deflection at the extraction grid and the deflection direction oppositely changes line by line, resulting in the beam split in the deflection direction. This beamlet deflection was well compensated also using the beamlet steering by the aperture displacement of the grounded grid. The beam ...
Radiation-and-thermal-combined degradation of some kinds of cable insulating and jacketing materials was evaluated by accelerated aging tests. Plasticized polyvinyl chloride (PVC), silicone rubber, crosslinked and non-crosslinked halogen-free flame-retardant polyolefins (NH-XLPO and NH-PO) and ethylene-propylene rubber (EP rubber) of experimental formulation were degraded at accelerated rates, that are 50-1000 times the degradation rate under standard conditions (e.g.; 1Gy/h, 50degC), and a method to assess the lifetime of these materials under standard conditions was studied. The degradation was investigated by measuring tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for these materials were in proportion to the increase in accelerated rate. The PVC lifetime estimated from sequential aging tests had a tendency to extend beyond that from ...
The purpose of this paper is to present a summary of new methods, employing Lie algebraic tools, for characterizing beam dynamics in charged-particle optical systems. These methods are applicable to accelerator design, charged-particle beam transport, electron microscopes, and also light optics. The new methods represent the action of each separate element of a compound optical system, including all departures from paraxial optics, by a certain operator. The operators for the various elements can then be concatenated, following well-defined rules, to obtain a resultant operator that characterizes the entire system. This paper deals mostly with accelerator design and charged-particle beam transport. The application of Lie algebraic methods to light optics and electron microscopes is described elsewhere (1, see also 44). To keep its scope within reasonable bounds, they restrict their treatment of accelerator design and ...
c-Jun N-terminal kinase 2 (JNK2) isoforms are transcribed from the jnk2 gene and are highly homologous with jnk1 and jnk3 transcriptional products....Full Text Available
Studies of ribulose-1,5-bisphosphate (RuBP) carboxylase from taxonomically diverse plants show that the enzyme from C3 and crassulacean acid metabolism pathway species exhibits lower Km(CO2)...Full Text Available
DescriptionThis new research programme activity on Urban Atmospheric Science will deliver aspects of the NERC strategy: Next Generation Science for Planet Earth. It has been developed as part of the Environment, Pollution & Human Health theme. Research in the Environment, Pollution & Human Health theme is directed at elucidating key environmental processes that form part of a causal pathway between an environmental hazard and disease outcome, and providing a predictive capability of the risk to human heal [continued...
We tested the hypothesis that the basal release of nitric oxide (NO) from endothelial cells modulates contractile activity in the corpus cavernosum (CC) via inhibition of the RhoA/Rho-kinase signaling...Full Text Available
BackgroundBiodiesel or ethanol derived from lipids or starch produced by microalgae may overcome many of the sustainability challenges previously ascribed to petroleum-based fuels and first generation plant-based biofuels. The paucity of microalgae genome sequences, however, limits gene-based biofuel feedstock optimization studies. Here we describe the sequencing and de novo transcriptome assembly for the non-model microalgae species, Dunaliella tertiolecta, and identify pathways and genes of importance related to biofuel production.ResultsNext generation DNA pyrosequencing technology applied to D. tertiolecta transcripts produced 1,363,336 high quality reads with an average length of 400 bases. Following quality and size trimming, ~ 45% of the high quality reads were assembled into 33,307 isotigs with a 31-fold coverage and 376,482 singletons. Assembled sequences and singletons were subjected to BLAST similarity searches and annotated with Gene Ontology (GO) and ...
The presence of a high number of activated T cells in the bloodstream and spontaneous proliferation of peripheral blood mononuclear cells in vitro are striking characteristics of human T-cell leukemia...Full Text Available
Several early genes of murine cytomegalovirus (MCMV) encode proteins that mediate immune evasion by interference with the major histocompatibility complex class I (MHC-I) pathway of antigen presentation...Full Text Available
The aim of this work is to suggest steps and policies to increase the introduction of cost-effective energy in conservation measures in Brazil. This report first addresses the motivations for a policy of energy efficiency and summarizes experiences in Brazil. It then considers the roles and perspectives of the diverse agents and review the instruments of policy. It concludes with an overview of strategic needs and lines of action.
We present evidence that the role of tryptophan and other potential intermediates in the pathways that could lead to indole derivatives needs to be reexamined. Two lines of Lemna gibba...Full Text Available
The aim of this study is to determine the effects of silver nanoparticles (Ag-NP) on vascular endothelial growth factor (VEGF)-and interleukin-1 beta (IL-1β)-induced vascular permeability, and...Full Text Available
BackgroundWhen eukaryotic cells are deprived of amino acids, uncharged tRNAs accumulate and activate the conserved GCN2 protein kinase. Activated Gcn2p up-regulates the general amino...Full Text Available
The Wnt signaling pathway is a robust regulator of skeletal homeostasis. Gain-of-function mutations promote high bone mass, whereas loss of Lrp5 or Lrp6 co-receptors decrease bone mass. Similarly, mutations...Full Text Available
DescriptionThe recent sequencing of the complete genomes of several streptomycete species revealed the presence of a large number of cryptic' secondary metabolic gene clusters, and led to the realisation that these organisms have the ability to produce many more natural products than had previously been recognised. One of the aims of our work is to identify the physiological signals and regulatory mechanisms responsible for the activation of these 'cryptic' pathways, thus unleashing the full biosynthetic p [continued...
This study examined the life histories of a group of emerging scholars in the field of mathematics education who identify themselves as having a particular interest in and concern for issues of equity and diversity. Experiences of being the "other," "bearing witness" to "othering experiences," and "orienting experiences" in relation to issues of equity proved to be prominent themes in participants' life histories. These experiences were then linked to the positionality that these scholars now have in relation to their research in mathematics education.
The clinicopathologic features of 472 ovarian epithelial clear cell neoplasms (4 adenofibromas [AFs], 41 atypical proliferative [borderline] tumors [APTs], and 427 carcinomas [CAs]) were studied in...Full Text Available
The initiation and progression of several forms of retinal degenerations involve excessive, repetitive, and/or sustained oxidative stress that, in turn, mediate photoreceptor cell damage and...Full Text Available
Hyperthermia (HT) is a strong adjuvant treatment with radiotherapy and chemotherapy because it causes tumor reoxygenation. However, the detailed molecular mechanisms of how HT enhances tumor oxygenation...Full Text Available
The yeast phosphatidylinositol transfer protein (Sec14p) is required for biogenesis of Golgi-derived transport vesicles and cell viability, and this essential Sec14p requirement is abrogated by inactivation...Full Text Available
Despite intensive efforts, the intracellular signaling pathways that mediate apoptosis remain unclear. The human B lymphoma cell line, B104, possesses characteristics that make it an attractive model...Full Text Available
Stem-boring insects and methyl jasmonate (MeJA) are thought to induce similar complex chemical and anatomical defenses in conifers. To compare insect- and MeJA-induced terpenoid responses, we analyzed...Full Text Available
The food ingestion consequences due to radioactive particulates of an accidental release, scenario 1-RD-3, are evaluated for Savannah River Technology Center. The sizes of land areas requiring the protective action of food interdiction are calculated. The consequences of the particulate portion of the release are evaluated with the HOTSPOT model and an EXCEL spreadsheet for particulates.
BackgroundThe Ras and Notch signaling pathways are frequently activated during development to control many diverse cellular processes and are often dysregulated during tumorigenesis....Full Text Available
G protein-coupled receptors (GPCRs) are known to modulate intracellular effectors involved in cardiac function. We recently reported homocysteine (Hcy)-induced ERK-phosphorylation was suppressed...Full Text Available
Given the possibility of highly pathogenic H5N1 avian influenza arriving in North America and monitoring programs that have been established to detect and track it, we review intercontinental movements...Full Text Available
Growth differentiation factor-9 (GDF-9), an oocyte-secreted member of the transforming growth factor β superfamily, progesterone receptor, cyclooxygenase 2 (Cox2; Ptgs2), and the EP2 prostaglandin...Full Text Available
African bovine trypanosomiasis caused by Trypanosoma sp., is a major constraint on cattle productivity in sub-Saharan Africa. Some African Bos taurus breeds are highly tolerant of infection, but the potentially more productive Bos indicus zebu breeds are much more susceptible. Zebu cattle are well adapted for plowing and haulage, and increasing their tolerance of trypanosomiasis could have a major impact on crop cultivation as well as dairy and beef production. We used three strategies to obtain short lists of candidate genes within QTL that were previously shown to regulate response to infection. We analyzed the transcriptomes of trypanotolerant N'Dama and susceptible Boran cattle after infection with Trypanosoma congolense. We sequenced EST libraries from these two breeds to identify polymorphisms that might underlie previously identified quantitative trait loci (QTL), and we assessed QTL regions and candidate loci for evidence of selective sweeps. The scan of the EST sequences ...
The expression status of the estrogen receptor alpha (ERα) and that of the epidermal growth factor receptor Her-2/neu frequently correlate inversely in breast cancers. While ERα-dependent...Full Text Available
Rice, the world's major staple crop, is a poor source of essential micronutrients, including folates (vitamin B9). We report folate biofortification of rice seeds achieved by overexpressing two Arabidopsis thaliana genes of the pterin and para-aminobenzoate branches of the folate biosynthetic pathway from a single locus. We obtained a maximal enhancement as high as 100 times above wild type, with 100 g of polished raw grains containing up to four times the adult daily folate requirement.
Synthesis of the Streptococcus pneumoniae type 3 capsule requires the pathway glucose-6-phosphate (Glc-6-P) → Glc-1-P → UDP-Glc → UDP-glucuronic acid (UDP-GlcUA)...Full Text Available
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...
Cyclin-Dependent Kinase 1 (CDK1) is the major M-phase kinase known also as the M-phase Promoting Factor or MPF. Studies performed during the last decade have shown many details of how CDK1 is regulated...Full Text Available
In Borrelia burgdorferi (Bb), the Lyme disease spirochete, the alternative σ factor σ54 (RpoN) directly activates transcription of another alternative σ...Full Text Available
Surveys of the antigenic properties of a wide range of variants of the H3N2 (Hong Kong) influenza virus subtype have revealed complex patterns of variants cocirculating during each of the main epidemic...Full Text Available
Extracellular ATP has been proposed as a paracrine signal in rodent islets, but it is unclear what role ATP plays in human islets. We now show the presence of an ATP signaling pathway that enhances...Full Text Available
Arsenic trioxide (As2O3), used to treat promyelocytic leukemia, triggers cell death via unknown mechanisms. To further our understanding of As2O3-induced...Full Text Available
Ethylene (C2H4) is a unique plant-signaling molecule that regulates numerous developmental processes. The key enzyme in the two-step biosynthetic pathway of ethylene is 1-aminocyclopropane-1-carboxylate...Full Text Available
The construction of Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences was completed in December 1993. HIMAC consists of an injector linac, two synchrotron rings, a high energy beam transport system and a beam irradiation system. Its accelerator parameters are based on the medical requirement, and helium, carbon, neon, silicon and argon were selected as the accelerated ion species. It has 3 therapy rooms (A{approx}C). Room A has a vertical irradiation system, Room C horizontal and Room B both vertical and horizontal. Two rings can supply beams independently to the vertical and horizontal irradiation systems. Clinical trial started on June 21 1994, after several basic biological and physics experiments lasting about 2 months. Cancer is the top cause of death in Japan since 1981, and people expect good treatment results at HIMAC. Proton and heavy ion radiotherapy has the ...
An Otto cycle engine with internal and external irreversibilities of friction and heat leakage, in which the heat transfer between the working fluid and the environment obeys linear phenomenological heat transfer law [q ?? ?(T ?1)], is studied in this paper. The optimal piston motion trajectory for maximizing the work output per cycle is derived for the fixed total cycle time and fuel consumed per cycle. Optimal control theory is applied to determine the optimal piston trajectories for the cases of with and without piston acceleration constraint on each stroke and the optimal distribution of the total cycle time among the strokes. The optimal piston motion with acceleration constraint for each stroke consists of three segments, including initial maximum acceleration and final maximum decel...
The Tevatron is a proton anti-proton accelerator collider operating at the Fermi National Accelerator Laboratory. The machine is currently delivering beam for the CDF and D0 experiments, which expect increasing luminosity until the conclusion of Run II, planned for 2009. The Laboratory defined a plan for achieving higher luminosity, and one of the tasks is the upgrade of the accelerator's beam position monitor (BPM). The Tevatron was built during the early eighties and some of its control systems, including the BPMs, are still the original ones. This paper describes the front-end software of the Tevatron BPM upgrade, from the requirements to the implementation, and the underlying hardware setup. The front-end software designed is presented, emphasizing its modularity and reusability, allowing it to be applied to other Fermilab machines.
The discovery that the cosmic expansion is accelerating has been followed by an intense theoretical and experimental response in physics and astronomy. The discovery implies that our most basic notions about how gravity work are violated on cosmological distance scales. One simple fix is the introduction of a cosmological constant into the field equations for general relativity. However, the extremely small value of the cosmological constant, relative to theoretical expectations, has led theorists to explore a wide variety of alternative explanations that involve the introduction of an exotic negative-pressure fluid or a modification of general relativity. Here we briefly review the evidence for cosmic acceleration. We then survey some of the theoretical attempts to account for it, including the cosmological constant, quintessence and its variants, mass-varying neutrinos, and modifications of general relativity, such as scalar-tensor and $f(R)$ ...
The measurements performed at CERN on prototypes and first pre-series main dipole magnets confirm the need of an active control of the Large Hadron Collider to compensate the dynamic field changes during the proton beam injection and acceleration. This control requires in turn an accurate forecast of the magnetic field in the accelerator. We plan to predict the field on the basis of two elements: theoretical field models tailored through the accumulated knowledge of the main magnets during series tests, and an on-line measurement system running on few reference magnets tracking the LHC current cycle. Data coming from this "Multipoles Factory" will result from the fusion of the two sources. Based on this system we foresee to deliver calibration information for pre-defined accelerator cycles as well as real time information for the active control. In this paper we report the conceptual design of the system, and we discuss the ...
The performance requirements of the Advanced Photon Source (APS) challenge the control system in a number of areas. This paper will review a few applications of advanced technology in the control and monitoring of the APS. The application of digital signal processors (DSPs) and techniques will be discussed, both from the perspective of a large distributed multiprocessor system and from that of embedded systems. In particular, two embedded applications will be highlighted, a beam position monitor processor and a DSP-based power supply controller. Fast data distribution is often a requirement. The application of a high-speed network based on reflective memory will also be discussed in the context of the APS global orbit feedback system. Timing systems provide opportunities to apply technologies such as high-speed logic and fiber optics. Examples of the use of these technologies will also be included. Finally, every modern accelerator control system of any size ...
A free-electron laser (FEL) two-beam accelerator (TBA) is proposed, in which the FEL interaction takes place in a series of drive cavities, rather than in a waveguide. Each drive cavity is 'beat-coupled' to a section of the accelerating structure. This standing-wave TBA is investigated theoretically and numerically, with analyses included of microwave extraction, growth of the FEL signal through saturation, equilibrium longitudinal beam dynamics following saturation, and sensitivity of the microwave amplitude and phase to errors in current and energy. It is found that phase errors due to current jitter are substantially reduced from previous versions of the TBA. Analytic scalings and numerical simulations are used to obtain an illustrative TBA parameter set.
This Report includes copies of transparencies and notes from the presentations made at the Center for Accelerator Physics at Brookhaven National Laboratory Editing and changes to the authors` contributions in this Report were made only to fulfill the publication requirements. This volume includes notes and transparencies on nine presentations: ``The Energy Exchange and Efficiency Consideration in Klystrons``, ``Some Properties of Microwave RF Sources for Future Colliders + Overview of Microwave Generation Activity at the University of Maryland``, ``Field Quality Improvements in Superconducting Magnets for RHIC``, ``Hadronic B-Physics``, ``Spiking Pulses from Free Electron Lasers: Observations and Computational Models``, ``Crystalline Beams in Circular Accelerators``, ``Accumulator Ring for AGS & Recent AGS Performance``, ``RHIC Project Machine Status``, and ``Gamma-Gamma Colliders.``
Phosphate/chromate and accelerated chromate coatings were produced on commercially available aluminium. The Cr, P and Fe components of the conversion coatings were determined by radioactive tracer technique. The tracer technique was combined with ion-exchange and film-sectioning methods to determine the chromium(III)/total chromium ratio in the accelerated chromate coating. It was found that during the acidic dissolution of the conversion coating the chromium(III)/total chromium ratio may suffer changes. The film-forming components in the metal/bath interface are supersaturated and deposited onto the aluminium. The identified components of the accelerated chromate coatings are Cr(OH)sub(3), Cr(OH)CrOsub(4) and Crsub(4)(Fe(CN)sub(6))sub(3) and the chromium(III)/total chromium ratio was found to be cca. 2/3. (author). 11 refs.; 5 figs.
Polarized electron sources for high energy accelerators took a significant step forward with the introduction of a new laser-driven photocathode source for the SLC in 1992. With an electron beam polarization of >80% and with {approximately}99% uptime during continuous operation, this source is a key factor in the success of the current SLC high-energy physics program. The SLC source performance is used to illustrate both the capabilities and the limitations of solid-state sources. The beam requirements for future colliders are similar to that of the SLC with the addition in most cases of multiple-bunch operation. A design for the next generation accelerator source that can improve the operational characteristics and at least minimize some of the inherent limitations of present sources is presented. Finally, the possibilities for producing highly polarized electron beams for high-duty-factor accelerators are discussed.
This paper describes the design and operating experience with a high performance control system tailored to the requirements of the SuperHILAC accelerator. A large number (20) of the latest 16-bit microcomputer boards are used in a parallel-distributed manner to get a high system bandwidth. Because of the high bandwidth, software costs and complexity are significantly reduced. The system by its very nature and design is easily upgraded and repaired. Dynamically assigned and labeled knobs, together with touch-panels, allow a flexible and efficient operator interface. An X-Y vector graphics system provides for display and labeling of real-time signals as well as general plotting functions. This control system allows attachment of a powerful auxiliary computer for scientific processing with access to accelerator parameters.
Macroparticle acceleration driven by low current, high voltage cathode spots has been investigated for potential applications ranging from micrometeoroid simulation to nanoparticle deposition/implantation. Acceleration by this process was observed to occur when nanometer and micrometer-sized particles were exposed to a high voltage pulse in the presence of a plasma discharge. The applied negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provide the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. Cathode spot behavior was also documented. The particle impact craters observed at the surface of downstream witness badges were documented using scanning electron microscopy and light microscopy. The observed impacts suggest the presence of energetic macroparticles formed ...
The advance in laser-plasma acceleration techniques pushes the regime of the resulting accelerated particles to higher energies and intensities. In particular the upcoming experiments with the FLAME laser at LNF will enter the GeV regime with almost 1nC of electrons. From the current status of understanding of the acceleration mechanism, relatively large angular and energy spreads are expected. There is therefore the need to develop a device capable to measure the energy of electrons over three orders of magnitude (few MeV to few GeV) under still unknown angular divergences. Within the PlasmonX experiment at LNF a spectrometer is being constructed to perform these measurements. It is made of an electro-magnet and a screen made of scintillating fibers for the measurement of the trajectories of the particles. The large range of operation, the huge number of particles and the need to focus the divergence present unprecedented ...
Mineral carbonation is based on the reaction of carbon dioxide with metal-oxide bearing minerals, usually containing magnesium or calcium silicate, to form hardly soluble carbonates and other solid byproducts. The concept is based on acceleration of the naturally occurring rock weathering process. In the present work the calcium silicate is present in the mineral, wollastonite. To accelerate the process and make it potentially useful for practical applications, mineral carbonation is conducted here using an indirect two-step route in which the reactive component (Ca^2^+ ions in considered case) is first extracted from the mineral matrix and afterwards carbonated. Two solid byproducts are formed in this process: silica in the extraction step and calcium carbonate in the carbonation step. In...
The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the surface of neutron star and trigger the acceleration of particles. The charged particles are accelerated mainly in the field of magneto-dipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magneto-dipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.
The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL). To ensure the vitality of FEL lasing, it is critical to preserve the high quality of the electron beam during acceleration and compression. The peak current and final energy are very sensitive to system jitter. To minimize this sensitivity, a longitudinal feedback system on the bunch length and energy is required, together with other diagnostics and feedback systems (e.g., on transverse phase space). Here, we describe a simulation framework, which includes a realistic jitter model for the LCLS accelerator system, the RF acceleration, structure wakefield, and second order optics. Simulation results show that to meet the tight requirements set by the FEL, such a longitudinal feedback system is mandatory.
This paper describes the dielectric and accelerated aging tests on prototype {plus minus}500 kV dc oil-filled self-contained cables. The extensive test program was required to evaluate the High-Voltage cables for the St. Lawrence river crossing of the {plus minus}500 kV Quebec-New England HVDC power transmission system. The paper relates the main elements of the test program. It describes the required insulation levels, the characteristics of the cables supplied by three different manufacturers, as well as the cables' installation for the type tests and accelerated aging tests. Details of the test program and procedures followed to carry out the tests are given. Findings of the tests are also reported.
A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.
A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.
Coherent Smith-Purcell radiation, emitted from short-bunched electrons passing by a lamellar-type grating of aluminum, has been observed in the millimeter wave region. The energy of the electrons is either 42 MeV when they are accelerated by an L-band linear accelerator or 150 MeV accelerated by an S-band one. The intensity of the radiation is proportional to the square of the beam current. The radiation is linearly polarized, and the electric vector of the radiation is in the plane defined by the observing point and the beam trajectory. The intensity decreases with the beam height, i.e. the distance of the beam from the surface of the grating, in accordance with the modified Bessel function of zeroth order. copyright 1996 American Institute of Physics.
This presentation focuses on the steps taken by the Westinghouse Hanford Company to meet an accelerated schedule for configuration and implementation of the MULTI LIMS in a multiple laboratory environment. The Westinghouse Hanford Company purchased the MULTI LIMS Laboratory Information Management System in August, 1993. Hardware delivery began in October, 1993. Less than four months later, the initial configuration was released for use in two Westinghouse Hanford Company laboratories. Several major obstacles were overcome during implementation. These include information gathering for base table loading, user training, acceptance of the new system by users of a legacy system, and hardware configuration issues. In summary, steps needed to be taken to meet the accelerated implementation schedule of the MULTI LIMS at the Hanford Site. The obstacles faced were overcome through the in-depth knowledge and help of the vendor and the dedication and ...
Luminosity-driven channeling extraction has been observed for the first time in a 900 GeV study at the Fermilab Tevatron. This experiment, Fermilab E853, demonstrated that useful TeV level beams can be extracted from a superconducting accelerator during high luminosity collider operations without unduly affecting the background at the collider detectors. Multi-turn extraction was found to increase significantly the efficiency of the process. The beam extraction efficiency was about 25%. Studies of time dependent effects found that the turn-to-turn structure was governed mainly by accelerator beam dynamics. An investigation of a pre-scatterer using the accelerator flying wire system showed that a fiber could produce a significant extracted flux, consistent with expectations. Based on these results, it is feasible to construct a parasitic 5-10 MHz proton beam from the Tevatron collider.
Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. The main use of AMS has been in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications. In addition, AMS has been recently applied in biomedicine to study exposure of human tissues to chemicals and biomolecules at attomole levels. There is also a world-wide effort to analyse rare nuclides of heavier masses, such as long-lived actinides, with important applications in safeguards and nuclear waste disposal. The use of AMS is limited by the expensive accelerator technology required and there are several attempts to develop smaller and cheaper AMS spectrometers. 5 refs.
The available data of single X-ray pulsars, their wind nebulae, and the SNRs which are connected to some of these sources are analysed. It is shown that electric field intensity of neutron stars tears off charged particles from the surface of neutron star and triggers the acceleration of particles. The charged particles are accelerated mainly in the field of magnetodipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magnetodipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.
This paper shows how molecular theory paves the way for accelerated aging tests of safety-related equipment in nuclear power plants, as required by NRC qualification programs. Arrhenius' model, based on an equation, provides useful information regarding the extent of molecular change as a function of time and temperature. Critical to determining the aging characteristics and qualified life of organic materials is the activation energy concept, which is derived from information gathered when the molecular reaction of the material is documented over the entire life cycle. In accelerated-aging applications, the importance of the model lies in characterizing the chemical related reactions of materials. The problem with the Arrhenius approach is that, in generating a testing period of reasonable duration, a rather high test temperature must be selected which may lead to an added and unrelated environmental effect.
This paper evaluates the performance of asphalt membranes by examining the chemical and permeability changes experienced by the asphalt during aging tests. The aging process was accelerated by exposing the asphalt to elevated temperatures, high oxygen concentrations, and increased strengths of aqueous oxidizing agents. The synergistic effects of the variables are evaluated by using a fractional factorial experimental design. The installation costs for a catalytically airblown asphalt liner are roughly half that of the typical polymeric materials, and also less than the rubberized asphalt membrane. The results of the initial accelerated aging tests of the asphalt membranes indicate that this material will provide stable, long-term leachate isolation in a mill tailings environment.
It is necessary to identify those measurable soil parameters which dictate the severity of the corrosion problem for coated irons and steels. When this is done, meaningful accelerated aging tests can be designed to validate the reduced corrosion rate for the planned coating. The following discussion introduces the important concepts and measurement parameters in the (a) design of accelerated aging tests, and (b) evaluation of the planned installation site for corrosion potential. Certain combinations of soil oxidation reduction potential (ORP) or electric potential (Eh), acidity (pH), fertilizer, water table, and soil hydraulic conductivity can result in severe corrosion of buried steel/iron vessels. If there are power lines nearby, additional loss of vessel material to the soil will occur. These factors are discussed.
Collective methods of ion acceleration using intense relativistic electron beams (IREB) have stimulated a great deal of interest in the past few years. The main virtue of an IREB collective ion accelerator is the high internal electric field strength. The primary drawback has been an insufficient ion energy gain or inadequate scaleability. An extensive study for generating a high quality electron beam has been done and is presented in Section 2. In Section 3 an intense ion injector study was conducted by the method of computer simulation. The last addition to the proposal was a design for producing a toroidal magnetic field. This field will be needed in a future study of high energy and high current electron beams.
Both travelers were members of a nine-person US delegation that participated in an international workshop on accelerator-based 14 MeV neutron sources for fusion materials research hosted by the University of Tokyo. Presentations made at the workshop reviewed the technology developed by the FMIT Project, advances in accelerator technology, and proposed concepts for neutron sources. One traveler then participated in the initial meeting of the IEA Working Group on High Energy, High Flux Neutron Sources in which efforts were begun to evaluate and compare proposed neutron sources; the Fourth FFTF/MOTA Experimenters' Workshop which covered planning and coordination of the US-Japan collaboration using the FFTF reactor to irradiate fusion reactor materials; and held discussions with several JAERI personnel on the US-Japan collaboration on fusion reactor materials.
A new type of radiation which occurs when particles are accelerated in the field of a longitudinal wave and in a transverse magnetic field is studied. The characteristics of such spontaneous radiation are obtained, and the influence of collective effects on the radiation is analyzed. The application of the findings to the theory of free electron lasers is discussed. 8 references.
A description of the FEL experiment underway at the 10 kA, 5 MeV Experimental Test Accelerator (ETA) is described. The facility has been designed to investigate the high-gain operation of an FEL.
This section of the report is concerned with the study of the metallisation, oxidation and doping of materials which are of importance to the micro-electronics industry. The Van de Graaff accelerator and radioactive tracers are used for studying surface and sub-surface behaviour of these materials.
The automatic real-time system operating at the LU-10 linac and providing measurements of the parameters such as the beam current (average and pulse values), the electron energy, the linear density distribution of beam current, and also the conveyor speed is described in the paper.
The principal paradigm for gamma-ray bursts (GRBs) suggests that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper explores how GRB prompt emission spectra can constrain electron (or ion) acceleration properties at the relativistic shocks that pertain to GRB models. The array of possible high-energy power-law indices in accelerated populations is highlighted, focusing on how spectra above 1 MeV can probe the field obliquity in GRB internal shocks, and the character of hydromagnetic turbulence in their environs. When encompassing the MeV-band spectral break, fits to BATSE/EGRET burst data indicate that the preponderance of electrons responsible for the prompt emission reside in an intrinsically non-thermal population. This differs markedly from typical populations generated in acceleration simulations; potential resolutions of this conflict such as the action ...
It has been discovered that iron(III) chloride complexes supported on activated charcoal oxidize phosphine under normal conditions. The process accelerates as the concentration of the chloride ions and the proton acid increases.
The discussion of energy usage falls naturally into three parts. The first is a review of what the problem is, the second is a description of steps that can be taken to conserve energy at existing facilities, and the third is a review of the implications of energy consumption on future facilities.
The mechanism of chemotherapy-induced acceleration of ovarian aging is not fully understood. We used doxorubicin, a widely used cancer chemotherapeutic, in a variety of in vivo xenograft,...Full Text Available
Obesity and metabolic syndrome result from excess calorie intake and genetic predisposition and are mechanistically linked to type II diabetes and accelerated body aging; abnormal nutrient and insulin...Full Text Available
The non-thermal supernova remnant RX J1713.7-3946 (G347.3-0.5) has recently been shown to be a site of cosmic ray (CR) electron acceleration to TeV energies (Muraishi et al. 2000). Here we present evidence that this remnant is also accelerating CR nuclei. Such nuclei can interact with ambient interstellar gas to produce high energy gamma-rays via the decay of neutral pions. We associate the unidentified EGRET GeV gamma- ray source 3EG J1714-3857 with a massive (~3*10 5 Mo) and dense (~500 nucleons cm -3) molecular cloud interacting with RX J1713.7-3946. Direct evidence for such interaction is provided by observations of the lowest two rotational transitions of CO in the cloud; as in other clear cases of interaction, the CO(J=2-1)/CO(J=1-0) ratio is significantly enhanced. Since the cloud is of low radio and X-ray brightness, CR electrons cannot be responsible for the bulk of its GeV emission there. A picture thus emerges where both electrons ...
Hyperglycemia and hyperinsulinemia accelerate both aging and cancer. Antidiabetic biguanides such as metformin decrease glucose, insulin and IGF-1 level. Metformin increases lifespan and prevents cancer...Full Text Available
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 ...
The NRL Long Pulse Induction Linac is being employed in a Free Electron Laser (FEL) experiment. The authors present results of beam transport and focusing experiments as well as measurements of the output radiation generated by various magnetic wigglers. The electron gun of the accelerator presently has a 17-cmdiam. cold cathode which is located in a nearly zero magnetic field (B /SUB z/ less than or equal to 5 G). The gun voltage is flat to within approx. = + or - 5% for 1.5 #mu#sec with this graphite brush cathode. The beam is focused by a series of solenoidal coils as it propagates through the 4-m-long accelerator."2 A solenoidal field which can be varied from 1-10 kG confines the beam in the FEL interaction region. Previous experiments were limited by poor beam transport, focusing, and matching into the relatively large solenoidal field in the FEL region. By smoothing the axial magnetic field profile in the accelerator ...
Physics and technology of free electron laser (FEL) are reviewed. Mechanisms of stimulated emission in FEL and its present status and future prospects are presented. Electromagnetic wiggler, two stage FEL and so on are also interpreted. Finally, accelerators and wigglers for FEL, recent FEL experiments and FEL applications are noted. (author).
The head of KEK expressed his dismay that SLAC has entered into a collaboration with 3 other US labs and proposes to build the next linear collider at Fermilab, Ilinois. KEK wants the next accelerator to be built somewhere in the Asian Pacific region (1 page).
Following a brief description of the SSC, the computing needs are discussed for both the accelerator design and the experimentation. The computing power required is considerably beyond that being used at present facilities, and parallel processing is expected to play an important role in supplying these needs.
The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although...Full Text Available
Accelerated oxidation treatment technology is introduced for use in the treatment of poor quality water by ozone injected from the bottom of a pressurized ozone contact tank. Under study as oxidation accelerating processes using ozone center about an ozone/hydrogen peroxide treatment, ozone/UV treatment, ozone/hydrogen peroxide/UV treatment, etc. As the result of testing, important respects in accelerated oxidation are learned, which are stated below. In the ozone-aided treatment, there are some substances, such as chromatic matters, that can be removed more rapidly when in direct contact with gaseous ozone. In this case, the concentration of remnant ozone poses an important problem. In relation to the amount of injected hydrogen peroxide, what is important is the ozone/hydrogen peroxide injection ratio relative to the substance that is to be removed. In the use of UV rays, since the decomposition rate of dissolved ozone is ...
Biological membranes are lamellar structures composed of two leaflets capable of supporting different mechanical stresses. Stress differences between leaflets were generated during micromechanical experiments...Full Text Available
Based on preliminary studies, some conclusions can be drawn concerning the Accelerator Fuel Enricher and Fission Product Exterminator (APEX). APEX-1 and APEX-2 systems can destroy TU's, /sup 137/Cs, and /sup 90/Sr at acceptable cost and efficiency. The principal difference between APEX-1 and APEX-2 is the in-reactor and in-circuit inventory of /sup 137/Cs and /sup 90/Sr. Stable and low hazard wastes can be disposed of by burial. Accelerator breeders can effectively sustain a fission reactor economy indefinitely. Military waste can be blended into commercial fuel cycle for transmutation. Accelerator and target technologies appear practical and could be developed in a few years. More detailed studies are needed to better define the technical and economic features of the LAFER and APEX cycles, so that comparative assessments can be made between these cycles, as well as with other transmutation and waste disposal ...
The existence and importance of an accelerated adjacent segment disc degeneration (ASD) after lumbar fusion have previously not been demonstrated by RCTs. The objectives of this study were, to determine...Full Text Available
Frontotemporal lobar degeneration is a progressive neurodegenerative syndrome that is the second most common cause of early-onset dementia. Mutations in the progranulin gene are a major cause of familial...Full Text Available