The substantia nigra pars reticulata (SNR) represents an endogenous seizure suppressing system, which may be targeted to develop treatments for generalized or multifocal epilepsies. This review summarizes...Full Text Available
... que celle precedemment decrite, dont la formation peut etre causee par une trempabilite inadequate, un temps de maintien isotherme trop court ou ...
Full text of publication follows: The hydrogen mitigation system of 20 igniters and 6 PARs is installed to control the hydrogen in the containment during severe accidents and design basis accidents, respectively, in Shin-Wolsung 1 and 2 nuclear power plants. The igniters are primarily installed at the hydrogen source locations, and the PARs are installed in the open spaces. The PARs will maintain the hydrogen concentration within the containment atmosphere below the limit of 4 v/o in accordance with Regulatory Guide 1.7 during design basis accidents. The igniters will maintain the hydrogen concentration within the containment atmosphere below the limit of 10 v/o in accordance with 10CFR50.34(f) during severe accidents. In addition, the PARs can be used as a supplementary means to control the hydrogen concentration during severe accidents because of their inherent passive characteristics. This paper ...
The performance of five well-known photosynthesis-light equations is compared by presenting a wide range of solutions in the form of dimensionless nomographs for the case where photosynthetically available radiation (PAR) reduces exponentially down the water column and is distributed sinusoidally through the photoperiod. These provide a simple means of calculating daily photosynthesis at any depth (e.g. at a benthic layer), or through a water column, avoiding the need to perform complex integrations. An examination is made of the accuracy of common approximate methods for calculating daily photosynthesis, assuming constant PAR. For optically deep water a modification is proposed to Talling's planimetric solution, to enable daily photosynthesis to be calculated more accurately, yet simply, over the whole range of possible PAR values. The errors induced by approximating the daily PAR distribution ...
Nov 15, 2006 ... Sick leave and other types of non-vested leave ... For FERS employees, NASA makes contributions of 10.7 percent to the defined benefit plan, ...
Plants require solar radiation for photosynthesis and their growth is directly related to the amount received, assuming that other environmental parameters are not limiting. Therefore, precise estimation of photosynthetically active radiation (PAR) is necessary to enhance overall accuracies of plant growth models. This study aimed to explore the PAR radiant flux in the San Francisco Bay Area of northern California. During the growing season (March through August) for 2?years 2007?2008, the on-site magnitudes of photosynthetic photon flux densities (PPFD) were investigated and then processed at both the hourly and daily time scales. Combined with global solar radiation (R S) and simulated extraterrestrial solar radiation, five PAR-related values were developed, i.e., flux density-based PAR ...
Based on the enhanced cooperation between Republic of Korea (ROK) and International Atomic Energy Agency (IAEA), IAEA installed new safeguards equipment (Unattended Monitoring System, UMS) at Wolsung unit 2 on January, 2005. The UMS was utilized in parallel with traditional human surveillance during the transfer campaign of Wolsung unit 2 (7 March - 22 July). Installation of UMS at all Wolsung units will be decided on the basis of the result of this test. The transfer campaign with UMS at Wolsung units 2 and 4 was started from September 1, 2006 at the same time. Implementation of UMS to the transfer campaign in Wolsung site will be considerably reduced the IAEA's inspection effort and burden of operator.
Based on the enhanced cooperation between Republic of Korea (ROK) and International Atomic Energy Agency (IAEA), IAEA installed new safeguards equipment (Unattended Monitoring System, UMS) at Wolsung unit 2 on January, 2005. The UMS was utilized in parallel with traditional human surveillance during the transfer campaign of Wolsung unit 2 (7 March - 22 July). Installation of UMS at all Wolsung units will be decided on the basis of the result of this test. The transfer campaign with UMS at Wolsung units 2 and 4 was started from September 1, 2006 at the same time. Implementation of UMS to the transfer campaign in Wolsung site will be considerably reduced the IAEA's inspection effort and burden of operator.
Stability concerns of the Par Pond Dam, an embankment structure in the Savannah River Site complex, resulted in a comprehensive evaluation of the state of its integrity. Specifically, excessive seepage through the embankment, slope failure due to an earthquake event as well as liquefaction potential of the embankment and the foundation are addressed and the potential of failure is evaluated. Lastly, remedial benefits of the addition of a berm structure are also assessed.
French ... Title Synthese d'agregats metalliques par radiolyse de solutions aqueuses de sels simples ou complexes. Etude par M. E. du greffage des agregats sur membranes de carbone.
The basic principles of determination of the ash content of coal by the title methods are outlined. A brief technical characteristic of the ash meters and radionuclide X-ray fluorescence analyzers manufactured by the PAR company is presented. (Z.S.). 4 figs., 7 refs.
The substantia nigra pars reticulata (SNR) controls seizures in a sex-specific manner. At postnatal day 15 (P15), SNR infusion of GABAA receptor agonist muscimol have proconvulsant...Full Text Available
Extraction of copper-, nickel-, zinc- and cadmium complexes with 4-(2 pyridilazo)-resorcin (PAR) is studied in the presence of 2-aminopyridine (Am). Maximum optical densities of the extracts are attained at pH=7.5-8.0; 6.0-7.0; 6.5-7.0 and 7.0-8.0, respectively. The ratio of components in the complexes extractable by chloroform was defined by the method of isomolar series and equilibrium shift. It is established that nickel and copper are extracted to the organic phase as the NiAm(PAR)_2 and CuAmPAR complexes, and, in the case of zinc and cadmium, complexes of different composition are extracted, for example Zn(Am)_2PAR and ZnAm(PAR)_2. The light absorption spectra are studied and molar extinction coefficients of complex extracts are determined at lambdasub(max). It is shown that the general low of light absorption is observed within a sufficiently wide range of concentrations for ...
Scandium reacts with 4-(2-pyridylazo)resorcinol in the presence of monocarboxylic acids (X) to form mixed-ligand complexes with a Sc:PAR:x ratio of 1:2:2. The chemical nature of this interaction has been established, and the extraction of these mixed-ligand complexes has also been investigated; stability constants and molar extinction coefficients have been calculated. The values of the latter decrease in the order CH_3COOH > CH_2ClCOOH > CCl_3COOH. The formation and extraction of mixed-ligand complexes in Sc-PAR-HX systems make it possible to increase the sensitivity and selectivity of scandium determination in comparison with the use of the Sc-PAR mono-ligand complex.
and audio technology. The exhibition will travel to muse- ums and science centers in several U.S. cities over the next 5 years. Back in the classroom, ...
Background:The aim of present study is to determine the long-term results of patients who undergo pars plana vitrectomy after retained nucleus into the vitreous.Setting:Service...Full Text Available
Established Investigators (K18) (PAR-09-090) NIH: Career Enhancement Award for Stem Cell Research (K18) (PA-09-110) NIDCD: NIDCD Research Career Enhancement Award for Established...
The technique of air diffusion by shifting presents several advantages in terms of thermal comfort, indoor air quality and energy conservation. This book presents the principle, dimensioning, and implementation of air shifting diffusion systems. (J.S.)
Discusses methods for determining ash content in coal using backscattering in X-ray fluorescence. The following aspects are evaluated: principle of ash content determination, energy sources, factors that influence measurement accuracy, reliability. Types of X-ray fluorescence analyzers developed in Czechoslovakia and manufactured in the Czech Republic are comparatively evaluated. Operation of the RPM 113.1 radionuclide X-ray fluorescence analyzer developed by the PAR company and used for measuring ash content in coal and coal calorific value is discussed. 7 refs.
Canary Islands are normally interested by dominant North-East winds that, in some meteorological conditions, can transport sand at high altitude from the Sahara desert. The dust may affect the efficiency of the telescopes and decreases the transparency of the sky. In order to maximize the scientific return of the telescopes located at the ORM, we present an analysis of the atmospheric dust content and its effects on astronomical observations. B, V and I dust aerosol astronomical extinction are derived. Using a 5 years series database of data taken from the four channel TNG dust monitor, we compute a mean hourly and daily values of the dust content. We have detected particles having size 0.3, 0.5, 1.0 and 5.0 um. Using a power law we have derived the content of 10.0 um particles. We found a typical local dust concentration ranging from 3x10^6 particles per cubic meter at 0.3 um, to 10^3 at 5.0 um and 10 ...
The atomic masses of the alkali-metal isotopes "6Li,"2"3Na,"3"9","4"1K,"8"5","8"7Rb, and "1"3"3Cs have been obtained from measurements of cyclotron frequency ratios of pairs of ions simultaneously trapped in a Penning trap. The results, with one standard deviation uncertainty, are: M("6Li)=6.015 122 887 4(16)u,M("2"3Na)=22.989769 282 8(26)u,M("3"9K)=38.963 706 485 6(52)u,M("4"1K)=40.961 825 257 4(48)u,M("8"5Rb)=84.911 789739(9)u,M("8"7Rb)=86.909 180 535(10)u, and M("1"3"3Cs)=132.905 451 963(13)u. Our mass of "6Li yields an improved neutron separation energy for "7Li of 7251.1014(45) keV.
We present physical properties of two submillimeter selected gravitationally lensed sources, identified in the Herschel Astrophysical Terahertz Large Area Survey. These submillimeter galaxies (SMGs) have flux densities > 100 mJy at 500 um, but are not visible in existing optical imaging. We fit light profiles to each component of the lensing systems in Spitzer IRAC 3.6 and 4.5 um data and successfully disentangle the foreground lens from the background source in each case, providing important constraints on the spectral energy distributions (SEDs) of the background SMG at rest-frame optical-near-infrared wavelengths. The SED fits show that these two SMGs have high dust obscuration with Av ~4 to 5 and star formation rates of ~100 M_sun/yr. They have low gas fractions and low dynamical masses compared to 850 um selected galaxies.
It was agreed that both of the Republic Of Korea (ROK) and the International Atomic Energy Agency (IAEA) cooperate with the new approach using the Unattended Monitoring Systems (UMS), the mailbox declaration and the short notice inspections, which can decrease the agency inspection efforts and operator' s burden. As a result of the positive cooperation of ROK for applying new approach, the IAEA could accomplish a successful implementation of new safeguards approach during last transfer campaigns at Wolsung site. As of the end of Feb. 2007, the IAEA installed the UMS at Wolsung units 2, 3 and 4. The transfer campaigns at Wolsung units 2 and 4 are performing from April, 2007. The IAEA will install the UMS at Wolsung unit 1 by the end of 2007. Then agency will inspect all of transfer campaign at Wolsung units by using new approach with UMS, mailbox declaration and SNI. It is based on the SSAC full ...
It was agreed that both of the Republic Of Korea (ROK) and the International Atomic Energy Agency (IAEA) cooperate with the new approach using the Unattended Monitoring Systems (UMS), the mailbox declaration and the short notice inspections, which can decrease the agency inspection efforts and operator' s burden. As a result of the positive cooperation of ROK for applying new approach, the IAEA could accomplish a successful implementation of new safeguards approach during last transfer campaigns at Wolsung site. As of the end of Feb. 2007, the IAEA installed the UMS at Wolsung units 2, 3 and 4. The transfer campaigns at Wolsung units 2 and 4 are performing from April, 2007. The IAEA will install the UMS at Wolsung unit 1 by the end of 2007. Then agency will inspect all of transfer campaign at Wolsung units by using new approach with UMS, mailbox declaration and SNI. It is based on the SSAC full ...
Preliminary experiments have been performed to investigate the effects of radiative cooling on plasma jets. Thin (3 um - 5 um) conical shells were irradiated with an intense laser, driving jets with velocities > 100 km/s. Through use of different target materials - aluminium, copper and gold - the degree of radiative losses was altered, and their importance for jet collimation investigated. A number of temporally resoved optical diagnostics was used, providing information about the jet evolution. Gold jets were seen to be narrower than those from copper targets, while aluminium targets produced the least collimated flows.
Hypoxia causes abnormal neonatal pulmonary artery remodeling (PAR) and inhibition of alveolar development (IAD). Transforming growth factor (TGF)-β is an important regulator of lung development...Full Text Available
We present here for the first time the tele-robotics system for hot-cells MT200-TAO (TAO stands for Teleoperation Assistee par Ordinateur or Computer Assisted Tele-robotics), able to replace a conventional telescopic medium tele-manipulator (extension 4 m; capacity 20 kg). The system is currently under evaluation in COGEMA/AREVA- La Hague hot-cells. (authors)
Although matrix metalloproteinase-9 (MMP-9) is involved in cardiomyocytes contractility dysfunction, tissue inhibitor of metalloproteinase-4 (TIMP-4) mitigates the effect of MMP-9, and proteinase-activated...Full Text Available
This text presents the annotations of all different articles of the law text concerning the sustainable development of radioactive materials and wastes. (A.L.B.)
Using the SCUBA bolometer array on the JCMT, we have carried out a submillimetre survey of Broad Absorption Line quasars (BALQs). The sample has been chosen to match, in redshift and optical luminosity, an existing benchmark 850um sample of radio-quiet quasars, allowing a direct comparison of the submm properties of BAL quasars relative to the parent radio-quiet population. We reach a submm limit 1.5mJy at 850um, allowing a more rigorous measure of the submm properties of BAL quasars than previous studies. Our submm photometry complements extensive observations at other wavelengths, in particular X-rays with Chandra and mid-infrared with Spitzer. To compare the 850um flux distribution of BALQs with that of the non-BAL quasar benchmark sample, we employ a suite of statistical methods, including survival analysis and a novel Bayesian derivation of the underlying flux distribution. Although there are no strong grounds for ...
A thermohydraulic study of MTR fuel element is presented as a basic requirement for the development of an irradiation facility for testing fuel elements. A computer code named 'Thermo' has been developed for this purpose, which can stimulate different working conditions, such as, cooling, power elements and neutron flux, performing all pertinent thermohydraulic calculations. Thermocouples were used to measure the temperature gradients of the cooling fluid throughout the IEAR-1 reactor core. All experimental data are in good agreement with the theoretical model applied in this work. Finally, a draft of the proposed facility and its safety system is presented. (author)
The situation of natural gas in the Federal Republic of Germany is described, with particular emphasis on the advantages and consequences of natural gas supply. The brochure discusses the role of natural gas on the energy market, the reliability of natural gas supply, the environmental impacts, the energy-saving effect of natural gas, natural gas prices, the competitive strength of the German gas industry, and the long-term reliability of natural gas supply. (orig.) [German] Die Situation des Erdgases in der Bundesrepublik Deutschland wird beschrieben, wobei die wichtigsten Vorteile und Auswirkungen der Erdgasversorgung besonders hervorgehoben werden. Es geht um die Stellung des Erdgases im Energiemarkt, die Sicherheit der Energieversorgung, Umweltschutz, Energieeinsparung durch Erdgaseinsatz, Erdgaspreise, Leistungsfaehigkeit der deutschen Gaswirtschaft und um die langfristig gesicherte Erdgasversorgung. (orig.)
The contribution attempts a definition of the concepts of ``technical facilities`` and ``facility management``. [Deutsch] Um mit der Ueberschrift zu beginnen: Was ist Gebaeudetechnik? Die Antwort ist nicht ganz einfach. An der TU Berlin gibt es einen Ingenieur-Studiengang mit dieser Bezeichnung. Es hat etwas mit dem Gebaeude, aber nicht viel mit Architektur zu tun, wie manchmal faelschlich angenommen wird. Um solche Missverstaendnisse gar nicht erst aufkommen zu lassen, hat sich die Gruppe des Vereins Deutscher Ingenieure, die sich mit der Gebaeudetechnik beschaeftigt, als `VDI-Gesellschaft Technische Gebaeudeausruestung` bezeichnet. (orig.)
Acid mine drainage represents one of the most important environmental problem facing the mining industry. If the tailings contain sulphur, acid mine drainage will be generated as soon as the tailings are exposed to oxygen. In this paper, the authors discussed a technique for the storage of acid mine drainage generating tailings that delays and even eliminates the occurrence. It was suggested that tailings should be piled by incorporating, at regular intervals, compacted waste rock. Thermal convection and diffusion will prevent oxygen from reaching the tailings, and limit water circulation. The modelling of transfer processes (heat, water, oxygen) in a well known tailings dump, the Doyon Mine, was performed, and the results compared to the modelling where compacted waste rock had been incorporated at regular intervals. The results indicated that by remaining saturated, the layers acted as capillary barriers preventing oxygen from reaching the tailings, therefore reducing significantly ...
The interest of irradiation by carbon ions is in the fact that the carbon ions leave all their energy to a determined depth. ( phenomenon known under the name of Bragg peak)This high diffusion in tissue gives an RBE particularly high. The indications of this therapy are chordomas, and chondrosarcomas of the skull base, some cyst adenoid carcinomas, pulmonary cancer, sarcomas, hepato carcinomas, melanomas. In the light of results in term of efficiency, the place of irradiation by carbon ions should widen. (N.C.)
The UFIP (French Petroleum Industry Association) studies concerning polluted sites and soils and their rehabilitation are presented: characterization of the admissible maximum fuel or gas oil content in the ground, the issue of time effects, and the risks it may induce for public health; study on the various pollutant impacts on the environment (underground waters, biotope...); approach to the development of a dynamical model describing these phenomena and their influence on man, in order to derive consistent and reasonable decontamination objectives
This paper presents general considerations concerning the application of artificial neural networks algorithms, more specifically the back-propagation learning algorithm and feed-forward multi-layer networks, to several problems in power system. The main application in power systems is the load forecasting, and two solution methods are used to solve it. (author). 45 figs., 32 tabs., 144 refs.
The Forsmark and the Laxemar investigation areas are examined by the Swedish Nuclear Fuel and Waste Management Co. for a possible construction of a deep repository for nuclear waste. In the case of a future leakage of waste, the radioactive isotopes could end up in the ecosystems above the repository. The fate of the radionuclides and their possible radiological impacts are then highly determined by ecosystem carbon cycling. An important part of the carbon cycling is the soil carbon effluxes, and in the investigation areas soil carbon effluxes have been examined with the closed chamber technique. This paper is divided into two parts. Firstly, there were problems with the equipment measuring the soil carbon dioxide efflux, and the first part is a description of the problem, how it was corrected and its possible causes. The second part is a manual in how to analyse data and calculate annual estimates of soil carbon efflux. The field measurement by the EGM-4 is just an occasional estimate ...
The economic development of eastern Europe was associated during the last 15 years with the following average annual increases in energy consumption: Approximately 1% in the sectors industry, building and transport, almost 7% in the farming sector, approximately 3% in households, and nearly 4% in the municipal sector. This trend will not continue. As the economic system shifts from centrally planned to free economy and as the previously secluded economy is forced to face world market conditions as well as changed pars of exchange and conditions of payment, it not only experiences a transitory, sharp dip of economic growth in general but, in particular, drastic structural changes. - While there is to be expected, on the whole a slump in national economic growth, in tradiational branches of industry (e.g., metallurgy, the chemicals and textile industry) as well as in farming, such sectors as the service industry and small trade are expanding. (orig./UA).
The elastic behaviour of YBaCuO specimens has been studied by very low-frequency isothermal internal-friction measurements. A relaxation peak is observed which is attributed to oxygen atom jumps, between A(1/2 0 0) and B(0 1/2 0) sites, in the CuO planes of the orthorhombic phase. A limit relaxation time {tau}{sub 0}, 2.6 {center dot} 10{sup -15}s, and an activation energy, 1.3eV, have been obtained from the shift of the maximum damping frequency observed when the measurement temperature is changed. The proposed values for the limit relaxation time and the activation energy are in good agreement with those previously proposed in the literature.
The passive films formed on 316L stainless steel in various NaCl solutions have been investigated by capacitance measurements (Mott-Schottky). Pitting parameters have been determined using the galvano-kinetic polarisation method. The obtained results reveal the existence of a shallow and a deep donor level localised in the band gap of the semiconducting oxide film. These energy levels are due to iron ions in the tetrahedral and octahedral positions. It also appears that the participation of the deep donor level effects the electric field. The study developed allows us to compare characteristic parameters of the electronic structure of the passive film to those related to pitting susceptibility. (authors) 25 refs.
The report constitutes a first bibliographic study defining the environments the most adapted to the geological mineral in-situ sequestration of CO{sub 2}. For each environment the lithology and the rocks permeability and porosity are analyzed. Thus the possible rocks and deposits in France are presented. (A.L.B.)
A study was conducted to determine the fitting soil moisture for the normal growth of two-year-old W. sinensis (Sims) Sweets by using gas exchange technique. Remarkable threshold values of net photosynthetic rate (Pn), transpiration rate (Tr) and water use efficiency (WUE) were observed in the W. sinensis leaves treated by various soil moisture and photosynthetic available radiation (PAR). The fitting soil moisture for maintaining a high level of Pn and WUE was in range of 15.3%?26.5% of volumetric water content (VWC), of which the optimal VWC was 23.3%. Under the condition of fitting soil moisture, the light saturation point of leaves occurred at above 800?mol?m?2?s?1, whereas under the condition of water deficiency (VWC, 11.9% and 8.2%) or oversaturation (VWC, 26.5%), the light saturatio...
ResumeLa convergence des solutions faibles du systeme de Navier-Stokes-Fourier-Poisson compressible avec un terme de frottement est etudiee dans la limite dun frottement infini, la loi de pression incluant, comme cas particulier, celle correspondant aux particules de Fermi-Dirac. La limite se trouve etre une solution faible dun systeme de Smoluchowski-Poisson non isotherme, la temperature ne dependant que de la variable temporelle et etant determinee par la conservation de lenergie totale.
This study has been carried out in the framework of a collaboration between the laboratory of processes automation (LAP, Caen (France)), and Air Com, a monitoring network for the prevention of atmospheric pollution in Basse-Normandie. It aims at obtaining a medium and long term forecast of the ozone level above the Caen city. The expected goal is to foresee the pollution peaks exceeding the warning thresholds, but the rareness of such events make them more difficult to predict. In order to solve this kind of problem, a neural modeling method combined with a noise injection technique has been implemented in order to obtain a sufficiently performing model over the whole domain of operation. (J.S.)
Adjustment of the rf phase in a linear accelerator is crucial for maintaining optimal performance. If phasing is incorrect, the beam will in general have an energy error and increased energy spread. While an energy error can be readily detected and corrected using position readings from beam position monitors at dispersion locations, this is not helpful for correcting energy spread in a system with many possible phase errors. Uncorrected energy spread results in poor capture efficiency in downstream accelerators, such as the Advanced Photon Source's (APS's) particle accumulator ring (PAR) or booster synchrotron. To address this issue, APS has implemented beam-to-rf phase detectors in the linac, along with software for automatic correction of phase errors. We discuss the design, implementation, and performance of these detectors and how they improved APS top-up operations.
The renovation programme of the Phenix nuclear power plant (fast neutrons reactor situated at Marcoule) has for objective to ensure the reactor operation lengthening. In this frame, expertise and monitoring operation in situ of materials have been started. The presence of sodium and a temperature at the cold breakdown of the primary circuit between 150 and 180 degrees (Celsius) imply, for fast reactors, very special conditions. In this context, Framatome has realised three intervening in the area of nondestructive testing: the inspection of the cone-shaped support ring, the monitoring of the upper part of the primary vessel and the monitoring of the intermediary exchanger equipment. (N.C.)
Bargmann's superselection rule, which forbids the existence of superpositions of states with different mass and, therefore, implies the impossibility of describing unstable particles in non-relativistic quantum mechanics, arises as a consequence of demanding Galilean covariance of Schr\\"odinger's equation. However, the usual Galilean transformations inadequately describe the symmetries of non-relativistic quantum mechanics since they fail to take into account relativistic time contraction effects which can produce non-relativistic phases in the wavefunction. In this paper we describe the incompatibility between Bargmann's rule and Lorentz transformations in the low-velocities limit, we analyze its classical origin and we show that the Extended Galilei group characterizes better the symmetries of the theory. Furthermore, we claim that a proper description of non-relativistic quantum mechanics requires a modification of the notion of spacetime in the corresponding limit, which is ...
Even if there have been efforts to validate remote-sensing-based energy balance models, which provide evapotranspiration (ET) maps over a large spatial scale, few studies have been conducted to validate their performance in Korea. In this study, surface energy balance fluxes including ET were estimated and inter-compared with two different models using the Landsat-5 Thematic Mapper (TM) image over a watershed scale in Korea. While there were larger spatial discrepancies for net radiation, soil heat and sensible heat fluxes on a pixel-by-pixel basis between the two models, relatively smaller spatial discrepancies for the latent heat flux and daily ET were detected. The spatial discrepancies for the daily ET were larger in low topography and dense vegetation ranges. Despite the different par...
SPEOS takes advantage of a geological situation which apparently does not occur much in Switzerland. The SPEOS pilot installation, which was erected in 1982, is designed for the supply of heat for about 500 persons. In the course of 10 cycles, the possibilities and limits of the seasonal heat storage were displayed. It was demonstrated that large quantities of heat with temperatures of up to 75 C can be stored in an aquifer. The behaviour of such a storage can be predicted with sufficient accuracy with mathematical models. (author) 12 refs.
This research deals with in the study of the use of innovating magnetic sensors in eddy current non destructive inspection. The author reports an analysis survey of magnetic sensor performances. This survey enables the selection of magnetic sensor technologies used in non destructive inspection. He presents the state-of-the-art of eddy current probes exploiting the qualities of innovating magnetic sensors, and describes the methods enabling the use of these magnetic sensors in non destructive testing. Two main applications of innovating magnetic sensors are identified: the detection of very small defects by means of magneto-resistive sensors, and the detection of deep defects by means of giant magneto-impedances. Based on the use of modelling, optimization, signal processing tools, probes are manufactured for these both applications.
The aim of this work is the study of the heat transfer and of thermal behaviour of the HF (high frequency) components (in fact capacitors) of the ITER-proto-2005-FCI antenna. Preliminary results carried out with the Castem software show that it is possible to cool the hottest part of the antenna efficiently. A water flow (1 bar, 25 Celsius degrees) or an helium flow (10 bars, 50 Celsius degrees) permit to limit the maximal value of the temperature to 270 Celsius degrees. A second software Ansys has allowed the author to simulate capacitors with more complicated shapes. (A.C.)
As the main forestry species in the Canary Islands (Spain), Pinus canariensis is frequently used in afforestation programs. Several nursery techniques are commonly employed to modify its morphology and physiology with the aim of improving post-planting survival and growth. In this work, we studied how fertilization and light regime treatments applied during the nursery period modify biomass allocation patterns and produce effects in gas exchange and root hydraulic conductance. Seedlings were grown for a 6-month period in the nursery under two light regimes (full sunlight and 40% PAR reduction), and three fertilization levels were applied in each light regime. Morphology, biomass allocation patterns, leaf gas exchange and hydraulic conductance of the whole root system were evaluated. Fertil...
A classic sum rule by Das et al. is extended to seven of the low-energy constant K{sub i}, introduced by Urech, which parameterizes electromagnetic corrections at chiral order O(e{sup 2}p{sup 2}). Using the spurion formalism, a simple convolution representation is shown to hold and the structure in terms of the chiral renormalization scale, QCD renormalization scale and the QED gauge parameter is displayed. The role of the resonances is studied as providing rational interpolants to relevant QCD n-point functions in the Euclidean domain. A variety of asymptotic constraints must be implemented which have phenomenological consequences. A current assumption concerning the dominance of the lowest-lying resonances is shown clearly to fail in some cases. (author)
An exposure chamber is described for the quantifiable addition of fine and ultrafine aerosol particulate matter directly to cells and used to demonstrate the in vitro cytotoxicity of fine 1,4-naphthoquinone particles to murine lung epithelial cells. The electrostatic particulate dosage and exposure system (EPDExS) operates on the principle of electrostatic precipitation and is shown to deposit fine and ultrafine aerosol particles directly to cells with 100% efficiency for particle diameters in the range of 40-530nm. This range is not limited by the EPDExS, but rather by the aerosolization method used for this study. Numbers of particles deposited onto the cells are counted with a condensation particle counter, negating any need to calculate or estimate particle exposure. The process of par...
L'invention concerne un procede de triage de cristaux irradies. Ce procede non destructeur comporte l'irradiation des cristaux par un rayonnement ionisant pendant une duree et avec une intensite telles qu'il se forme des centres colores distinctifs dans les matieres contenant des ions aluminium. Les cristaux colores qui correspondent en teinte et en profondeur de couleur a des teneurs en aluminium en dehors de la teneur desiree peuvent etre separes. On peut isoler ainsi des matieres de quartz, de verre, de silicates exemptes d'aluminium dans un melange, ou bien on peut choisir des fractions de ces matieres, chacune contenant une teneur uniforme en aluminium.
The near infrared (NIR) upgrade to the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT), RSS/NIR, extends the spectral coverage of all modes of the visible arm. The RSS/NIR is a low to medium resolution spectrograph with broadband imaging, spectropolarimetric, and Fabry-Perot imaging capabilities. The visible and NIR arms can be used simultaneously to extend spectral coverage from approximately 3200 A to 1.6 um. Both arms utilize high efficiency volume phase holographic gratings via articulating gratings and cameras. The NIR camera is designed around a 2048x2048 HAWAII-2RG detector housed in a cryogenic dewar. The Epps optical design of the camera consists of 6 spherical elements, providing sub-pixel rms image sizes of 7.5 +/- 1.0 um over all wavelengths and field angles. The exact long wavelength cutoff is yet to be determined in a detailed thermal analysis and will depend on the semi-warm instrument cooling ...
There are 4 CANDU reactors at Wolsung site together with a spent fuel dry storage associated with unit 1. These CANDU reactors, classified as On-Load Reactor (OLR) for Safeguards application, change 16- 24 fuel bundles with fresh fuel in everyday. Especially, the spent fuel bundles are transferred from spent fuel bays to dry storage throughout a year because of the insufficient capacity of spent fuel pond. Safeguards inspectors verify the spent fuel transfer to meet safeguards purposes according to the safeguards criteria by means of inspector's presence during the transfer campaign. For the verification, 60-80 person-days of inspection (PDIs) are needed during approximately 3 months for each unit. In order to reduce the inspection effort and operators' burden, an Unattended Monitoring System (UMS) was designed and developed by the IAEA for the verification of spent fuel bundles transfers from wet storage to dry storage. Based on the enhanced ...
We report on recent progress and improvements in the metal-organic chemical vapor deposition (MOCVD) growth of mid-infrared lasers and using a high speed rotating disk reactor (RDR). The devices contain AlAsSb active regions. These lasers have multi-stage, type I InAsSb/InAsP quantum well active regions. A semi-metal GaAsSb/InAs layer acts as an internal electron source for the multi-stage injection lasers and AlAsSb is an electron confinement layer. These structures are the first MOCVD multi-stage devices. Growth in an RDR was necessary to avoid the previously observed Al memory effects found in conventional horizontal reactors. A single stage, optically pumped laser yielded improved power (greater than 650 mW/facet) at 80K and 3.8um. A multi-stage 3.8-3.9um laser structure operated up to T=170K. At 80K, peak power greater than 100mW and a high slope- efficiency were observed in gain guided lasers.
By joining the `climate association of European cities`, Frankfurt has agreed to reduce its CO{sub 2}-emissions by 50% by the year 2010. The so-called `climate offense 1991` was the first regulatory paper to be set up by a community to reach this goal over a long term. This report now represents the present level of the project. Main points are the development of houses with low entropy, the retrofitting of heating systems, water saving measures and energy management. (BWI) [Deutsch] Durch den Beitritt zum `Klima-Buendnis der Europaeischen Staedte` hat sich die Stadt Frankfurt/M. verpflichtet, die CO{sub 2}-Emissionen bis zum Jahr 2010 um 50% zu senken. Mit der sog. `Klimaoffensive 1991` wurde dann erstmals von einer Kommune in Deutschland ein detailliertes Regelwerk aufgestellt, um dieses Ziel langfristig erreichen zu koennen. Der vorliegende Bericht stellt den aktuellen Stand des Projektes dar. Kernpunkte sind die Entwicklung von ...
Ventilation systems must ensure high room air quality with minimum energy consumption in all states of operation. Systems for ventilation on demand are increasing their market share. (orig./MSK) [Deutsch] Oberste Aufgabe von Raumlufttechnischen Anlagen ist die Sicherstellung guter Raumluftqualitaet bei minimalem Energieverbrauch unter allen Betriebsbedingungen. Um dieses Ziel zu erreichen, setzt sich am Markt zunehmend die bedarfsgeregelte Lueftung durch. (orig./MSK)
3407 events were registrated up to a distance of 300 m during the period from 12.10.1989 to 31.12.1990, of which 385 could be precisely located. Activities were determined in areas surrounding the dam construction traversal drifts and boreholes at the 875 m level, near the large cavern at 975 m depth, in drifts and caverns above the 875 m level and in the vicinity of the rock salt/carnallitite transition zone to the south-east of the 875 m level. Energies and source parameters were calculated by means of spectres. Energy variations range from 10 J to 10{sup -4} J, the source radii from 3.5 m to 0.2 m, the source dislocations from 10{sup -6} m to 10{sup -8} m, and the stress drops from 10{sup 5} Pa to 0.06 10{sup 5} Pa. Magnitude and type of events observed are usual for mines. The microseismic activity provides an insight into the origin as well as changes of stress and rock mechanical material properties. (orig./HP). [Deutsch] Im Zeitraum 12.10.89 - 31.12.90 wurden 3407 Ereignisse bis ...
Resistance to thyroid hormone (RTH) is an autosomal dominant disease caused by mutations in the human thyroid receptor beta gene on chromosome 3. Individuals with RTH have an increased incidence of attention deficit hyperactivity disorder (ADHD). The purpose of this study was to search for developmental brain malformations associated with RTH. Forty-three subjects (20 affected males [AM], 23 affected females [AF]) with resistance to thyroid hormone and 32 unaffected first degree relatives (18 unaffected males [UM], 14 unaffected females [UF]) underwent MRI brain scans with a volumetric acquisition that provided 90 contiguous 2 mm thick sagittal images. Films of six contiguous images beginning at a standard sagittal position lateral to the insula were analyzed by an investigator who was blind with respect to subject characteristics. The presence of extra or missing gyri in the parietal bank of the Sylvian fissure (multimodal association cortex) and multiple Heschl`s ...
Faced with increasing indications for the use of iodine-131 labelled lipiodol in the treatment of hepatocellular carcinoma (HCC), it appears essential to develop an individualized dosimetrY so we can predict the potential effectiveness of this treatment and adjust the activity to be injected. We developed a dosimetric protocol based on imagery and dedicated to calculation of the tumoral dose during the treatment of hepatocellular carcinoma by iodine-131 labelled lipiodol. This concept was developed on a SPECT- CT gantry, and integrates corrections for the phenomena of attenuation, diffusion and dead time. The dose is calculated according to the formalism proposed by the Medical Internal Radiation Dose Committee (MIRD). This protocol was applied to a series of 41 patients in the framework of a retrospective study. The results obtained in terms of biodistribution are compatible with previously published data. The total biological response rate is 42% (n= 41) for the first treatment and ...
The University of Michigan (UM) is a member of a team of researchers, including the universities of Florida, Texas, and Tennessee, along with Oak Ridge National Laboratory, developing robotic for hazardous environments. The goal of this research is to develop the intelligent and capable robots which can perform useful functions in the new generation of nuclear reactors currently under development. By augmenting human capabilities through remote robotics, increased safety, functionality, and reliability can be achieved. In accordance with the established lines of research responsibilities, our primary efforts during 1991 will continue to focus on the following areas: radiation imaging; mobile robot navigation; three-dimensional vision capabilities for navigation; and machine-intelligence. This report discuss work that has been and will be done in these areas.
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... Project Details Title: Influence of increasing droplet concentrations on properties of stratocumulus clouds and climate Supervisor: Dr Alan Gadian Funded by: Engineering and Physical Sciences Research Council (EPSRC) Start date: October 2006 My project involves use of the UK Met Office Unified Model (UM) to calculate the global effect of modifying stratocumulus droplet concentrations on the earth's radiation balance, as well as use of ... Publications Latham, J; Rasch, P; Chen, CC; Kettles, L; Gadian, A; Gettelman, A; Morrison, H; Bower, K; Choularton, T (2008) Global temperature stabilization via controlled albedo enhancement of low-level maritime clouds, Philos. Trans. Roy. Soc. A, 366(1882), pp3969-3987. doi:10.1098/rsta.2008.0137 Current Students | Internal ...
This study describes the construction of a simple mathematical model its validation through the simulation in transient state of a real cycle performed by a solar refrigerator based on physical adsorption using an activated carbon/methanol pair. The deviation from experimental results was 4% for the cycled mass of methanol, 2.2 % for maximum collector average temperature, and 3 x 10{sup -3} for the theoretical cycle coefficient of performance. Additional simulations of the same cycle inputting values representing different types and larger amounts of activated carbon showed the possibility of increasing the cycled methanol mass up to about 150%. (author) 26 refs., 16 figs., 9 tabs.
An effect of laser-cooling of water was observed for the first time with a temperature decrease dT = -2.2 K after irradiation of liquid water surface by a powerful Ar-Xe pulse laser with a pulse energy of about 1 J and wavelength L = 1.73, 2.63 and 2.65 um. The discovered effect can apparently be ascribed to the optical excitation of vibrational states of H2O molecules followed by an endothermic consolidation of chemically active excited molecules into a quasi-stable cluster-like structure. The measured time dependences of the cooling effect show that a typical life time of the new state of water amounts to hours. It has also been shown that the life time of the excited vibrational molecular states due to a radiation trapping effect can be estimated to at least hundreds of seconds.
The aim of this work is the implantation and characterization of a neutron radiography system that uses an electronic device for attainment of images in real time, for its implementation in the nuclear research reactor Argonauta at IEN/CNEN (Nuclear Engineering Institute of the Brazilian Nuclear Energy Commission). The Electronic Imaging System in Real Time is composed by a scintillator screen for neutron, a video camera (CCD), a digital plate and a computer with specific computational programs for digital processing of the images. The System in installed real time is apt to carry through neutron radiography inspections of static and dynamic events of several types of samples. (author)
The article describes the solar aircraft `Icare`` which was constucted in a joint project by engineers and scientists of Stuttgart university. The aircraft requires slightly more than one kW for staying up. The theoretical fundamentals are presented in the dissertation of Peer Frank, ``Aircraft design for minimum fuel consumption` (Institute of Aircraft Engineering, Stuttgart, 1992). (orig.) [Deutsch] Allein mit Sonnenkraft kann das Flugzeug `Icare` fliegen. Es entstand in Gemeinschaftsarbeit von Ingenieuren und Wissenschaftlern der Stuttgarter Universitaet. Das Solarflugzeug Icare benoetigt etwas ueber ein Kilowatt, um oben zu bleiben. In seiner Doktorarbeit `Die Auslegung von Flugzeugen mit geringstem Antriebsleistungsbedarf` (Institut fuer Flugzeugbau, Stuttgart, 1992) hat der Duesseldorfer Peer Frank die theoretischen Grundlagen dazu behandelt. (orig.)
Background/Purpose: Congenital esophageal stenosis (CES) is a rare malformation. Endoscopic dilations represent a therapeutic option. This study retrospectively evaluated the efficacy and safety of a conservative treatment of CES. Patients and Methods: Patients diagnosed with CES since 1980 by a barium study or endoscopy were reviewed. Endoscopic ultrasonography (Olympus UM-3R-20-MHz radial miniprobe, Olympus Corporation, Tokyo, Japan), available from 2001, allowed for the differential diagnosis of tracheobronchial remnants (TBR) and fibromuscular hypertrophy (FMH) CES. All children underwent conservative treatment by endoscopic dilations (hydrostatic and Savary). Results: Forty-seven patients (20 men) had CES. Fifteen were associated with esophageal atresia; and 8, with Down syndrome. Mea...
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m3 in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m2 in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
The urban zone needs clean air to assure public health. To achieve this goal several filter samples were collected in different sites in Algiers city. Toxic elements such as: Na, Mg, Cl, Sc, Cr, Ti, V, Fe, Co, Cu, Zn, Se, Br, Ag, Sb, Ce, La, Hf, Ta and Hg have been measured in the filters using neutron activation analysis technique. Irradiation of filter samples and standards were carried out in Es-Salem reactor. The experimental procedure and the results are discussed. We noted during this work that the upper limit values for suspended dusts and the high concentrations for some toxic elements found are due to the weather conditions and intense road traffic around collecting sites. (authors)
The report published in 2003 by the European committee on the risk of irradiation (C.E.R.I.) criticizes a part of the ICRP recommendations relative to the internal contaminations.Consequently, I.R.S.N. wishes to supply its own analysis. The present report points the questions linked to the internal contamination and to the difficulties inherent to the risk incurred after chronic exposure.Consequently it does not treat all the problems of the workers and populations radiation protection. (N.C.)
The control of nitrogen oxides (NO{sub x}) emissions will become a major challenge in the forthcoming years, in the domain of automotive industry or industrial burners. Pulsed combustion offers an imaginative solution which does not affect the combustion efficiency. In this paper, the efficiency of this method is demonstrated using the burner of a 20 kW domestic boiler. The actuator is simply installed on the air intake. Two types of actuators have been tested successfully: a loudspeaker and a rotative valve. Both can produce 100 to 1000 Hz frequencies and can lead to a reduction of 20% of NO{sub x} emissions. The feasibility of the concept is also demonstrated on a 840 kW liquid fuel-oil burner. The mechanisms involved during an excitation are explained using the CH{sup *} radical imaging. Results show an important reorganization of the flow and of the flame structure. During each excitation cycle, an annular swirl occurs at the leading edge of the flame catching and develops during ...
A new industrial process allowing to reach very high cooling rates in the cooling section after soaking of a continuous annealing line for steel sheets is presented. This process constitutes the successful conclusion of a long term research programme, jointly carried out at CRM and Arcelor Cockerill-Sambre for three years, including laboratory experiments, pilot scale trials and several industrial campaigns. It is running on from developments performed in the framework of the HOWAQ (Hot Water Quench) process. The process successively combines a moderate cooling step (600 deg C/s for 0.8 mm thick strips), in boiling water, and a faster cooling step (above 700 deg C/s), by impinging turbulent cold water in a box. Its main features are simplicity, resulting from advanced developments, soundness, flexibility and cooling homogeneity. As treated steel products are characterized by improved mechanical properties, outstanding surface quality (corrosion resistance) and exceptional flatness. The ...
This report prepared for the Swiss Federal Office of Energy (SFOE) describes the practical realisation and testing of a heat recovery system based on a one-stage organic Rankine cycle with R134a as the working fluid. The waste heat has a temperature of 95 {sup o}C and originates from a gas engine that powers a small co-generation plant fuelled with biogas produced on-site. Two similar cycles have been built, ORC1 with one and ORC2 with two turbines. Only ORC1 has been tested so far. The maximum efficiency measured in these tests was 6.64% (theoretical Carnot-efficiency: 17 %) and the electric power output was 5.0 kW. The problems encountered during commissioning are described and recommendations for further improvements are given.
Magnetic resonance imaging (MRI) has rapidly attained a major position among the examinations used in the diagnostic approach of multiple sclerosis because it is highly sensitive in demonstrating lesions. However, these lesional images may have several meanings, and there is the problem of distinguishing between oedema, which is said to reflect recent lesions, and gliosis which is thought to betray old lesions. The intrinsic MRI parameters studied (i.e. relaxation times) are unable to make this distinction, whereas it is provided by paramagnetic contrast media such as gadolinium. There is no correlation between the changes observed at MRI and the severity of the disease. Another problem is the accuracy of lesion localization, since visualization is predominantly macroscopic. This raises several questions about the demonstration of correlations between clinical signs and site of the lesion(s). At the moment, several teams of neuroradiologists are trying to find the most reliable method ...
This project of law concerns an additional protocol to the agreement of warranties signed on September 22, 1998 between France, the European atomic energy community and the IAEA. This agreement concerns the declaration of all information relative to the R and D activities linked with the fuel cycle and involving the cooperation with a foreign country non endowed with nuclear weapons. These information include the trade and processing of nuclear and non-nuclear materials and equipments devoted to nuclear reactors (pressure vessels, fuel loading/unloading systems, control rods, force and zirconium tubes, primary coolant pumps, deuterium and heavy water, nuclear-grade graphite), to fuel reprocessing plants, to isotope separation plants (gaseous diffusion, laser enrichment, plasma separation, electromagnetic enrichment), to heavy water and deuterium production plants, and to uranium conversion plants. (J.S.)
RESUME: Cet article propose une tude du r le croissant que joue l valuation dans la gouvernance des services domicile en Europe. L introduction de quasi march s dans plusieurs pays europ ens va de pair avec un processus d autonomisation de la fonction d valuation qui devient un v ritable outil de r gulation de la concurrence. Une analyse compar e des situations en Belgique, France et Royaume Uni, tant de la demande que de l offre de services, met en vidence les tensions r currentes dans les objectifs de l valuation (qualit des services, ma trise des budgets sociaux, cr ation d emploi), la faible prise en compte de la qualit de l emploi ainsi que les limites des dispositifs standardis s d valuation au regard de la rh torique du libre choix de l usager (consommateur).
Aim: The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise. Methods: Ten adults with T2D (age: 55.8+/-7.7 years; weight: 79.4+/-14.0kg; fasting glucose: 133.0+/-36.7mg.dL^-^1) underwent: (1) AER: 20min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO2, respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interve...
Vanadium doped manganese bi-oxide has been obtained from a solution containing both cations. The X-ray diffraction of this material indicates a rutile-type phase but the enlargement of some lines supports the existence of several lattice defects. Also the particle size of the doped material is significantly smaller than the one of the non-doped material obtained in the same conditions. The presence of pentavalent vanadium inside the lattice leads to a small amount of trivalent manganese. Electron microscopy shows the existence of defects which have a tendency of becoming well-ordered and to stabilize a sur-structure. At ambient temperature, the electrochemical behaviour of doped manganese bi-oxide is greatly improved when compared to the non-doped phase. This behaviour is due to the presence of numerous lattice defects and to the smaller size of crystallites. In polymer batteries, the behaviour is similar the one of the non-doped material for which the kinetics performances are ...
The confocal Raman micro-spectroscopy has been used for the study of a Lithium/polymer electrolyte-LiTFSI/V{sub 2}O{sub 5} type battery in which the polymer electrolyte thickness is of about 80 {mu}m. The analysis is performed on the side of the battery thanks to a specially designed cell which preserves all the characteristics of the real system. The analysis is performed on 20 points aligned between the anode and the cathode and with a depth of several tenth of {mu}m. The analysis of data obtained during charging/output cycles allows to evaluate the gradients of salt concentration inside the electrolyte, the pollutions of LiOH, Li{sub 2}CO{sub 3}, Li{sub 2}O and Li{sub 3}N -type at the lithium interface, but also the structural modifications of the cathode material. The in-situ study of concentration gradients inside the electrolyte is of prime importance for the understanding of dendrites growth. (J.S.) 11 refs.
This thesis enters the field of highly compressed materials equation of state studies. In particular, it focuses on the case of laser shock compressed iron. This work indeed aims at getting to the conditions of the earth's core, comprising a solid inner core and a liquid outer core. The understanding of phenomena governing the core's thermodynamics and the geodynamic process requires the knowledge of iron melting line locus around the solid-liquid interface at 3.3 Mbar. Several experiments were performed to that extent. First, an absolute measurement of iron Hugoniot was obtained. Following is a study of partially released states of iron into a window material: lithium fluoride (LiF). This configuration enables direct access to compressed iron optical properties such as reflectivity and self-emission. Interface velocity measurement is dominated by compressed LiF optical properties and is used as a pressure gauge. Using a dual wavelength reflectivity diagnostic, ...
ACRO, a NGO equipped with a laboratory to measure radioactivity, runs the Citizen Watchdog of Radioactivity in the Environment. Involving many volunteers, it monitors regularly the French coast of the Channel and many rivers of the North half of France. It also makes investigations in other places. Such an action is aimed to supplement the official monitoring, not to replace it, in order to answer to the worries of the population. This monitoring shows that some radioelements, such as iodine 129, cobalt 60, tritium, etc. released in the environment by nuclear facilities can be detected on very large areas. Carbon 14 was detected up to almost 4 times the background in vegetables around the reprocessing plant of La Hague. ACRO also sits in many official committees to transmit the point of view of the populations exposed to the radioactive pollution. It is lobbying for a decrease of the release authorization, especially for the elements that are discharged in large quantity in the ...
The partitioning of transuranium elements (TRUs) from high-level liquid waste (HLLW) through the use of pyrometallurgical technology has been underway since 1986, for the purpose of the improving the safety and public acceptance of the disposal of high-level vitrified waste. Prior to the pyrometallurgical partitioning process, the alkali metals can be separated at the denitration process for oxide conversion of HLLW, chlorination in a chloride salt bath can be used to effectively convert oxides to chlorides, and evaporated chlorides can be captured with high efficiency in another adopted chloride salt bath. The higher separation factors between actinides and rare earths are obtained in a LiCl-KCl/Bi system than in a LiCl-KCl/Cd system. Based on the results, we propose a practical process flow for partitioning TRUs from HLLW by pyrometallurgical technology. This process was demonstrated successfully using simulated purex waste. Each element of the TRUs was separated with an efficiency ...
Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited to describe our ...
180 deg magnet chamber is used in Folded Tandem Ion Accelerator for passage and 180 deg bending of ion beam. The chamber is placed between 180 deg terminal magnet (Electro-magnet), which is used for bending, and analysing the beams. Magnet with a particular magnetic field strength bends ions of only specified mass energy product through a precise path. There is also a space limitation in the direction of magnetic field. Both of them require the magnet chamber to be of a close tolerance. Accuracy of center distance between inlet and outlet port of the magnet chamber has to be at par with the concentricity of high energy and low energy beam line. To achieve this we started the fabrication of magnet chamber by following two methods: a) Circular rolling and bending of rectangular tube for 180 deg sector of magnet chamber b) Machining 180 deg sector in two half and welding. By first method we could not achieve the desired result although the method is very promising. ...
Le Club d’Orientation du CERN vous propose de venir participer à la cinquième étape de la coupe d’automne Genevoise. Celle-ci sera organisée samedi 16 octobre par le club de Lausanne-Jorat (Canton de Vaud). Un fléchage depuis le Mont-sur-Lausanne en direction de Cugy vous conduira au Chalet à Gobet. 5 circuits seront proposés sur la carte Le Flon. Les inscriptions et les départs se feront sur place de 13h à 15h. Il est prévu une initiation à 13h30 pour les débutants. Les deux dernières étapes de la coupe d’automne sont prévues pour vendredi 22 octobre au soir et samedi 23 octobre après-midi. Le Club d’Orientation du CERN Informations sur le site http://cern.ch/club-orientation
This work is based on the study of cesium ({sup 118,146}Cs) and francium ({sup 207-213}Fr,{sup 220-228}Fr) isotopes by hyperfine atomic spectroscopy and on the interpretation of these results from the nuclear physics point of view. The measured nuclear quantities are: the spin, the magnetic moment, the electric quadrupole moment and the mean square charge radius. The experimental method which is based on hyperfine optical pumping with a tunable laser, followed by magnetic analysis of the atoms is described in the first part. Results related to atomic physics are also presented. In the second part, these data are interpreted in the framework of nuclear models. The deformation of light cesium isomers are compared to values obtained from a theoretical self-consistent calculation. Heavy francium isotopes are situated in an area where the existence of static octupole deformations have been predicted. The odd-even staggering measured on the mean square radius is abnormal in this region. ...
This article, published in issue 80 of 'l'ACROnique du nucleaire', aims to retrace the early steps in the consideration of the possibility of a nuclear accident in France, with the inclusion of 'non-institutional' participants and applying the lessons learned in Belarus in the contaminated territories around the Chernobyl nuclear power plant. After a review of the origin of the involvement of the Association pour le Controle de la Radioactivite dans l'Ouest (ACRO) in addressing post-accident issues alongside the populations living in an environment polluted by radioactivity, it discusses, from the critical viewpoint of an NGO, the context and the working method adopted for this examination. This is followed by some key elements of the programme and unresolved questions about the available body of knowledge which motivates research and about the method adopted for the work. The conclusion, moderately optimistic, highlights some ...
Systemic sclerosis is an autoimmune connective tissue disorder characterized by a widespread microangiopathy, autoimmunity and fibrosis of the skin and of various internal organs. Microangiopathy is characterized by a reduced capillary density and an irregular chaotic architecture that lead to chronic tissue hypoxia. Despite the hypoxic conditions, there is no evidence for a sufficient compensative angiogenesis in SSc. Furthermore, vasculogenesis is also impaired. An imbalance between angiogenic and angiostatic factors might explain the pathogenetic mechanisms of SSc vasculopathy. As far as angiogenic factors are concerned, within the most important are vascular endothelial growth factor (VEGF) and its receptors, platelet derived growth factor (PDGF), transforming growth factor beta (TGF-?), fibroblast growth factor -2 (FGF-2), angiopoietin 1 (Ang-1), stromal cell-derived factor 1 (SDF-1/CXCL12), endothelin-1 (ET-1), monocyte chemoattractant protein -1 (MCP-1), urokinase type ...
Modelization of crack propagation and theoretical prediction of rupture are the two main objectives of researchers in stress corrosion cracking. Nevertheless, to reach this aim, the behavior of the passive film which appears spontaneously on the substrate in contact with an environment has to be known. This structural and mechanical characterization is all the more difficult because the number of parameters is important: crystallinity rate, defects concentration, thickness (about a few nanometers), electric field, chemical composition (a lot of oxides are present), peeling layers (atomic structure for example) and some hypothesis can be made about their multi-layer structure, their chemical composition or their epitaxial character... Passive films formed on 316L or 304L stainless steels in different aqueous solutions (in ambient air, in MgCl{sub 2} at 117 deg. C...) have been studied and some important remarks about their mechanical properties are made (brittle behavior, strong or weak ...
The spontaneous ionic polymerization of 4-vinyl-pyridine in presence of mono-tosylated or bromated short chains of poly(ethylene oxide)-(PEO) is used to prepare amorphous comb-like poly-cations with low Tg. The polymer electrolyte properties of these new structures have been studied without any addition of salts. The ionic conductivity of these fixed cation poly-electrolytes depends on the length of the grafted PEO and varies from 10{sup -7} to 10{sup -4} S/cm between 25 and 80 deg. C. It is only weakly dependent on the nature of the cation but it is controlled by the movements of the pyridinium cation which are facilitated by the plastifying effect of the POE chains which do not directly participate to the ionic transport. (J.S.) 17 refs.
Borehole stability is affected to a significant extent by the 3D local and regional stress field. Preliminary information on underground stress fields is provided by the World Stress Map, which shows N-NW stress at a depth of about 5000 m for the Voelkersen field. Earlier data analyses showed various directions in the range of 310-360 degrees. This was assumed to be a methodical error. An extensive study was carried out to evaluate and interpret all relevant information provided by borehole tests, borehole logs, and drill core measurements. [German] Standsicherheit und Stabilitaet von Bohrungen werden ganz wesentliche beeinflusst durch das umgebende dreidimensionale lokale und regionale Spannungsfeld. Fuer die Planung zukuenftiger (horizontaler) Bohrungen und die Erzeugung kuenstlicher Risse (''fracs'') spielt das Spannungsfeld eine bedeutende Rolle. Erste Hinweise ueber das regionale Spannungsfeld im Untergrund gibt die World Stress Map, in der ...
In coke-oven operations flue-gas valves are used to switch the regenerator function from rich gas firing to lean gas firing. Compared with the simple geometry of the other parts of the flow path, which comprise flues and regenerators, the narrow and winding passages of the flue-gas valves give rise to relatively high losses in pressure. Without the construction of high (and therefore expensive) chimneys, this means that operating problems may well arise due the inadequate suction capacity. The project focused on the theoretical and experimental analysis of a coke-oven flue-gas valve. The primary aim was to reduce the pressure drop through the valve without modifying its external geomerty. The internal flow characteristics created by different valve geometries under a variety of operating conditions were simulated using the commercial CFD code Fluent/UNS, which provided velocity and pressure distributions. A half-scale model valve was constructed in order to characterise the internal ...
Compared to the reference year of 1990, CO{sub 2} emissions of the Federal Republic of Germany have been curbed by about 12%, primarily as a result of industrial backfitting and pollution abatement measures accomplished in the industrial infrastructure of the new Federal Laender of Germany. Federal Government policy sticks to the previous commitment, to reduce carbon dioxide emissions by 25% by the year 2005. Current forecasts and scenarios of future greenhouse gas emissions show that only immediate adherence to a very stringent reduction policy might ensure that this ambitious goal will be achieved. In this context, any change of the baseline data and scenarios hitherto used for progonostic assessments is a crucial factor, so that the article here discusses the impacts of a change in the nuclear generation scenario, as recently ventilated by the German Federal Government, and expected effects on public power supply. (orig./CB) [Deutsch] Ausgehend von dem Bezugsjahr 1990 sind die ...
Alter both oil crisis, of 1973 and 1979, a bad effect of the elevated costs and continuously increment of the oil prices was noted, for this reason, the interest for renewable energies sources widely available in developing countries was increased. All over the world, governments have formulated main objectives for energies savings and search for friendly technologies, taking into account the effects related with the environment. The imminent scarcity of fossil fuels has made humanity the rational use of primary energies, as a result of these; new plants with improved technology have been conceived taking into account energy savings and efficiency improvement. In this context, biomass gasification technologies are important, since they consist in techniques of parallel production of electricity and heat from just one fuel. This work consists in the development of a gasifier down draft of 100 kW for an internal combustion engine, which includes its sizing process and its energy ...
Expression of IGF-2 and changes in its expression in response to systemic endocrine alterations have not been demonstrated for adipocytes. Adipocytes were induced to develop within cultures of 3T3-L1 cells using a medium containing 0.5mM isobutylmethylxanthine, 1uM insulin and 100ng hydrocortisone/ml for 48 hours of exposure. Cultures containing developing adipocytes were incubated with 10% pig serum and 1 uM insulin for several days. The resultant adipocyte cultures were then treated with either 10% pig serum, diabetic pig serum or hypophysectomized pig serum in DMEM for 48 hours. Adipocytes within the cultures were separated from undifferentiated cells using percoll density gradient centrifugation. Total RNA was isolated from adipocytes and dot blotted. Blots were probed with a {sup 32}P-cDNA probe for rat IGF-2. IGF-2 was expressed by the adipocytes and the pattern of expression showed specific differences between serum treatments; IGF-2 ...
...and welcome to ...lab also known as berkeley lab my name is jeff miller and ...and a public affairs i'd like to ? ...but space is science center and ...berkeley albany high school science department and berkeley high school science department and oakland high school science ...be a q. and ...here please use and because we wanna make sure that your questions are here ...heard of also for the latest developments on science and technology ...guy we're going to be any more and more new features i hope ...and change ...thank you ? much and thank you for coming on the welcome to my world of and mayotte science journalist and what i've done for the last almost thirty years ...people about things about which there passionate and national religion tonight and ...people to explain the science and and i asking the question so what ...and ...worldwide and what it does best ? uh ...bench science and turn it into reality what do you scientists and ...uh they take scientific theory and they turn ...
The report describes the processing of TiSi{sub 2}, MoSi{sub 2} and Ti{sub 5}Si{sub 3} by means of metal injection molding (MIM). First, the sintering activities of the three materials were investigated. After this, the viscosities of different mixtures of organic binder and powders of the three materials were determined, and in the final stage, components were produced by injection molding, the binder was removed, and the components were sintered. TiSi{sub 2} in powder form could be sintered to more than 95% of its theoretical density after 4 h at 1386 C. Metallographic analyses proved leaktightness of the component at this density. In the case of Ti{sub 5}Si{sub 3}, it was found that this material requires very long sintering times and high sintering temperatures for sintering to about 94% of its theoretical density. Metallographic analyses showed that only about 90% of the theoretical density was reached. MoSi{sub 2} in powder form could be sintered to only 90% of its theoretical ...
CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the inner ear and cerebello-pontine angle. HRCT best depicts osseous ...
The project is intended to yield information on the transfer factors describing the transfer of ingested radionuclides to breast milk for the following elements: antimony, cerium, chromium, cobalt, gallium, lanthanum, molybdenum, niobium, radium, ruthenium, silver, thorium, titanium, and uranium. Those yet unknown or poorly known transfer factors are required in order to be able to develop a reliable model for description and assessment of the transfer of the radionuclides and the possibly resulting hazardous doses to infants, and for subsequent formulation of recommendations for radiological protection of the population. (orig./CB) [German] Ziel des Projektes ist die Ermittlung von Transferfaktoren fuer den Uebergang von Radionukliden aus der Nahrung der Muetter in die Muttermilch fuer die Elemente Antimon, Cer, Chrom, Cobalt, Gallium, Lanthan, Molybdaen, Niob, Radium, Ruthenium, Silber, Thorium, Titan und Uran. Um die Exposition und damit die moegliche Gefaehrung ...
By retrofitting the existing steam turbine dual purpose power plant with a gas turbine plant and a secondary waste heat boiler the Technische Werke Ludwigshafen AG have considerably improved the energy generation in energetic, economic and ecological terms. The extension of the existing system to a combined cycle process has lead to this positive effect. The erection of a boiler plant during the first two construction phases has fully met the optimistic expectations. (orig.) [Deutsch] Mit der Nachruestung eines vorhandenen Dampfturbinen-HKW um eine Gasturbinenanlage mit nachgeschaltetem Abhitzekessel haben die Technischen Werke Ludwigshafen AG ihre Energieerzeugung entscheidend in energetischer, oekonomischer und oekologischer Sicht optimiert. Insbesondere die Erweiterung des vorhandenen Systems zu einem GuD-Prozess fuehrt zu dieser positiven Bilanz. Die Errichtung der Kesselanlage in den ersten beiden Bauabschnitten hat die optimistischen Erwartungen voll ...
Hard surface finishing represents the final manufacturing step for functional areas of machine elements in state-of-the-art production. Raceways of rolling bearing rings are ground and honed to the required low roughness. Plastic deformation is restricted to a narrow edge zone of the hardened steel. Reheating of the machined components below the martensite tempering or bainite transformation temperature results in a marked decrease of the XRD line width on the surface. The investigated samples are made of through-hardened standard bearing steel 100Cr6 (international denotation: SAE 52100). On the basis of a material model that explains the effect as a complex diffusion process of dislocational carbon segregation, i.e. static strain aging, the measured kinetics of the XRD line width reduction is simulated by an Arrhenius-type equation, which describes the rate-controlling reaction step of temper carbide dissolution. The formation of a small white-etching surface layer of around 1 ...
Licensing procedures are of great importance in the entire decision-making and planning process for erection of cogeneration power plants. The paper presented is a condensed version of the ASUE guide published in May 1999 and gives compact and topical information about legal and procedural aspects for orientation of people not yet familiar with the licensing procedures. An initial outline lists and characterises the procedures involved, which then are explained in greater detail, accompanied by flowsheets and diagrams. (orig./CB) [German] Genehmigungsverfahren besitzen im Entscheidungs- und Planungsprozess eine grosse Bedeutung. Um Planern, Bauherren und Behoerden hierzu einen kompakten und aktuellen Ueberblick bieten zu koennen, wurde dieses Referat als Kurzfassung der im Mai 1999 veroeffentlichten ASUE-Broschuere zusammengestellt. Sie bietet vor allem denjenigen eine Hilfestellung, die noch keine Erfahrungen mit den Genehmigungsverfahren gesammelt haben. ...
This article describes a methodology to determine the best strategy in an open bid, where oil and gas fields are the targets for exploration. Based upon the previous bid rounds for a given specific area - the Campos Basin, for that matter -, the data were statistically treated to fit a probability density function, modelling the value of bids offered by the competing companies. By means of techniques and concepts pertaining to Game Theory a balance matrix was built for values of bids made by companies as a function of the company alone in assumed bid rounds. At the end of each british auction, participants of this simultaneous game, using the rationality principle, aimed at winning the tender on the oil field aimed for, through the use of better answers with respect to its rival competitor. The game goal was maximize return on investment purchase in the decisions of lease blocks purchases in the auctions, or to try minimize its opponents gains. Proceeding with the work, this time, ...
Biodiesel can be produced from numerous materials, including by-products of animal chain. In this scenario, the chicken's oil, that is located and an environment not explored for biodiesel production, can be a good alternative in South and Southeast Brazilian Region, where they are slaughtered around 9.100.000 chickens per day. In order to determine the specific consumption from a generator set with single cylinder 6.6 kW of power and generation capacity of 5 kW, using chicken oil biodiesel (B-100), were performed the bench test using a auxiliary tank, precision scale and an energy analyzer. Were conducted four treatments (25%, 50%, 75% and 100% of generating capacity). The worst SC was the engine at 25% of generation capacity (1.5 kW) and better with 75% of maximum load (3.75 kW) with a mean of 479.34 g kWh{sup -1}. By Turkey's test ant 5% probability there was a significant difference only for the first treatment. (author)
Wider coal lines and larger power plant units necessitate measures for increasing the capacity of the mills without driving up power consumption and installation costs. The result of this development is the modern ALSTOM bowl mill. This paper indicates the stages of development which were necessary for this and the experience which could be accumulated through these measures. The paper also describes in detail the areas of flow in the mills, of design of milling equipment, of mill power supply and of grading in this development. (orig.) [Deutsch] Breitere Kohlebaender und groessere Kraftwerkseinheiten zwingen zu Massnahmen, um die Leistung der Muehlen zu vergroessern, ohne jedoch den Kraftbedarf und die Installationskosten in die Hoehe zu treiben. Das Ergebnis dieser Entwicklung ist die moderne ALSTOM-Schuesselmuehle. Der Beitrag zeigt, welche Entwicklungsschritte hierzu erforderlich waren und welche Erfahrungen mit den Massnahmen gesammelt werden konnten. Im ...
Melting in a cokeless cupola furnace fuelled with natural gas is a novel, energy-saving and environment-friendly process. In order to be able to monitor the processes inside the furnace with detailed mass and heat balances, an experimental furnace with an efficient measuring system was constructed in the framework of a research project financed by the BMFT and Messrs. Eisenwerke Dueker GmbH und Co. KG, Laufach, Germany. (orig./HS) [Deutsch] Das Schmelzen im kokslosen erdgasgefeuerten Kupolofen ist ein neues, energiesparendes und umweltfreundliches Verfahren. Um die Vorgaenge im Ofen mit umfassenden Stoff- und Waermebilanzen erfassen zu koennen, ist im Rahmen eines vom BMFT und der Firma Eisenwerke Dueker GmbH und Co. KG, Laufach, finanzierten Forschungsvorhabens, ein Versuchsofen mit umfangreicher Messeinrichtung gebaut worden. (orig./HS)
The principle of radiodiagnosis consists in the fact the X-ray beam is attenuated at different degrees by distinct tissues. For this reason, the anatomical structures have distinct radiological opacities, that produce the radiographic image. The progresses in radiology are related to the development if new radiographic image formation systems that enable an amplification in the quality, with low dose and/or risk to the patient. The objective of this work is the sensitometric valuation of a screen-film combination, that is still the most used, for the standardization, of radiographic images. Thinking about this, were constructed homogeneous phantoms of the chest, skull and pelvis, for the calibration of X-ray beams, with the purpose of obtaining radiographic images of good quality, basing in the routine of a radiodiagnosis service and in the scientific knowledge. Questions were approached about the choice of the suitable equipment, that allow the obtention of k Vp and m As combinations, ...
The current discussion on worldwide climate change suggests that the current situation is unusual or extreme, and that climate changes never - or hardly ever - occurred in the centuries before. The author discusses whether this is really the case, and whether air pollution abatement measures can really help. His answers are based on the findings of palaeoclimatology. [German] Verfolgt man die Diskussion um den derzeitigen Klimawandel, so gewinnt man den Eindruck, Aussergewoehnliches und Extremes wuerde geschehen, und man bekommt zudem ueber Beratungsgremien und Medien vermittelt, dass sich in den Jahrhunderten vor dem heutigen Klimawandel das Klima nicht oder nur wenig geaendert hat. Es wird auch der Eindruck erweckt, man koenne das Klima stabilisieren und durch Emissionsminderungsmassnahmen das Klima schuetzen. Ist Klimaschutz eine loesbare Herausforderung oder ueberschaetzen wir Menschen unsere Moeglichkeiten? Man kann versuchen, sich an die Beantwortung dieser ...
A heat transfer (condenser) of a domestic freezer was tested in a vertical channel in order to study the influence of the chimney effect in the optimization of the heat transfer coefficient. The variation of the opening of the channel, position and the heating power of the heat exchanger in the heat transfer coefficient was considered. The influence of the surface emissivity on the heat transfer by thermal radiation was studied with the heat exchanger testes without paint and with black paint. The air velocity entering the channel was measured with a hot wire anemometer. In order to evaluate the chimney effect, the heat exchanger was testes in a open ambient. This situation simulates its operational conditions when installed on the freezer system. The variables collected in the experimental procedures was gathered in the form of dimensionless parameters as Nusselt, Rayleigh, Grashof and Prandtl numbers, and dimensional parameters of the convection. The results showed that the highest ...
Much of the current technology on 3D-prestack depth migration is based on the Kirchhoff method and the traveltime information needed for this purpose is obtained by the ray-theory approximation. The main motivation driving these options is to reduce computations but it can also have an adverse effect on the quality of results. Experience with real data indicates that the corresponding poststack data migrated by the reverse-time method often yields superior results. Considerable computational efficiency can be obtained by employing nonuniform coarse grid spacing during the reverse-time migration. We followed this strategy for developing a parallel scheme for doing 3D- prestack depth migration. However, we worked only on a small subset of shot gathers whose determined by the Quasi-Monte Carlo method. The results were indistinguishable from those obtained by using a much larger population of uniformly spaced shot gathers. We present examples of migration of 3-D data. (author)
The onshore Potiguar basin has nowadays around 5.000 artificial lifting petroleum wells, distributed into 80 fields located on the states of Rio Grande do Norte and Ceara, representing approximately 8% of the national oil production. For that, well maintenance service, realized by Workover Rigs, is essential to preserve the oil productivity of the reservoirs on these fields. However, as the number of rigs is lower than to the number of wells needing maintenance, the task of administrating the management of such equipment according to the demand created by the wells, generates an optimization problem. The decision for a rig intervention on a well depends on parameters such as flow rate, depth, wasted time on intervention, distance from the rig to the next well, type of operation, rig capacity, environmental risks, etc. The objective of this paper is to present an interactive Computational System for Support Decision to the optimized management of the wells attended by the rig fleet. ...
To study the biogeochemical behaviour, mobility and transport of trace metals in seawater (Se, Mo, Cd, Pb, Hg, Cu, Co, Fe, Ni, Zn), in suspended particulate matter (Mo, Cd, Pb, Cu, Co, Fe, Ni, Zn, Al, Mn) and in sediments of the inner and outer coastal regions, samples were collected on 3 separate cruises during a one year period (Mai 1993 - April 1994) at 20 stations in the coastal area of Mecklenburg-Vorpommern. Standard hydrographic parameters, nutrients and dissolved oxygen were also measured. Priority was taken to establish the methods for the determination of molybdenum and selenium. To study the behaviour of these two elements in detail, longterm measurements were carried out weekly between January 1993 and June 1994 at the `Messsteg/Warnemuende`. Because of parallel measurements correlations to biological, chemical and hydrographic parameters have been tested. The total database is summarized in the Appendix. The results are presented in 30 figures and 13 tables and are ...
Clinical studies have proved the effectiveness of local ablading methods in pations with non-resectable liver metastases of a colorectal carcinoma. RF ablation and LITT are a potentially curative therapy option and an alternative to systemic chemotherapy; the latter is carried out primarily for reducing tumour size with the goal of secondary resectability. The number of R0-sesectable metastases can be enhanced by a combined therapy of surgery and local ablading methods, e.g. by preoperative, intraoperative or postoperative ablasion of further non-resectable tumours during surgery. Systemic chemotherapy combined with surgery as an adjuvant method is not recommended unless in cases of non-abladable tumour recidivation. Currently, systemic chemotherapy is used as a neo-adjuvant therapy for tumour size reduction with the goal of secondary resectability or, in case of inoperability, local ablation. (orig.) [German] Abladierende Verfahren. Klinische Studien belegen die Effektivitaet der ...
The study examines the isothermal fatigue properties of novel ODS iron-base or nickel-base superalloys at temperatures of 850 C and 1050 C. The materials are different in grain structure and texture, so that particularly the effects of grain structures and textures can be studied. In order to also perform examinations of creep-fatigue interactions, various load cycles are applied. It is shown that the LCF-affected life of the grain structures of both alloy types is determined by the elastic modulus. The cyclic lifetimes determined by the conventional Manson-Coffin method for both alloy types exhibit differences of up to two orders of magnitude. Using the product of the total strain range and the elastic modulus, however, will yield precise life predictions. Under conditions of LCF stress only, the grain structure has no effect on the materials` service life, other than in the case of creep-fatigue, but the grain structure has a decisive influence on the damage mechanisms and the course ...
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A study conducted at the IHS had the aim to obtain basic information on whether it is possible to build flow turbines following the free jet principle that are on a par with, or superior to, the conventional design, especially in terms of performance and the efficiency curve. Several inflow contours with a ventilated free jet and a conventional flow turbine were studied. The direct comparison of these variants revealed a slightly enhanced peak load efficiency and a very distinct superiority of the free jet contour during partial load. But the efficiency of all variants failed to attain the values claimed by commercial manufacturers. As compared to the initial contour, peak load efficiency was enhanced by 5 per cent. During partial load, the variants studied showed a distinct superiority of the free jet concept over the contour of conventional flow turbines. (orig.) [Deutsch] Am IHS wurde eine Untersuchung mit dem Ziel durchgefuehrt, grundlegende Aussagen zu ...
Fuel irradiation leads to a swelling resulting from the formation of gaseous (Kr, Xe) or solid fission products which are found either in solution or as solid inclusions in the matrix. This phenomena has to be evaluated to be taken into account in fuel cladding Interaction. Fuel swelling was studied as a function of burn up by measuring the corresponding cell constant evolution by X-Ray diffraction. This study was realized on Mixed Oxide Fuels (MOX) irradiated in a Pressurized Water Reactor (PWR) at different burn-up for 3 initial Pu contents. Lattice parameter evolutions were followed as a function of burn-up for the irradiated fuel with and without an annealing thermal treatment. These experimental evolutions are compared to the theoretical evolutions calculated from the hard sphere model, using the fission product concentrations determined by the APPOLO computer code. Contribution of varying parameters influencing the unit cell value is discussed. Thermal treatment effects were ...
The oxide colloidal route, developed in the laboratory for mono-metallic catalysts, consists in preparing a metallic oxide hydro-sol which leads to the supported catalyst after deposition onto a support and an activation stage. In this work, this method has been adapted to the preparation of alumina supported bimetallic Pd-Sn catalysts to determine its interest for the control of the properties of the bimetallic phase (size, composition and structure). In the preliminary study concerning tin oxide sols, SnO{sub 2} (size=2,3 nm) and Sn{sub 6}O{sub 4}(OH){sub 4} (size = 25 nm) nano-particles were synthesized by neutralization respectively for tin(IV) and tin(H). The control through the pH of the aggregation of the PdO and SnO{sub 2} particles revealed that increasing oxide solubility promotes integral re-dispersion of the oxide particles. To synthesize oxide bimetallic sols, three strategies were defined. Copolymerization (formation of a mixed oxide nano-sol by cross condensation of both ...
The aim of this work is to simulate the reduction by hydrogen of the tri-uranium octo-oxide U{sub 3}O{sub 8} (obtained by uranium trioxide calcination) into uranium dioxide. The kinetics curves have been obtained by thermal gravimetric analysis, the hydrogen and steam pressures being defined. The geometrical modeling which has allowed to explain the trend of the kinetics curves and of the velocity curves is an anisotropic germination-growth modeling. The powder is supposed to be formed of spherical grains with the same radius. The germs of the new UO{sub 2} phase appear at the surface of the U{sub 3}O{sub 8} grains with a specific germination frequency. The growth reactivity is anisotropic and is very large in the tangential direction to the grains surface. Then, the uranium dioxide growths inside the grain and the limiting step is the grain surface. The variations of the growth reactivity and of the germination specific frequency in terms of the gases partial pressures and of the ...
This work presents a study of the {sup 1}P{sup 0} excited states of He that can be reached by absorption of a single photon carrying an energy close to the double ionization threshold (DIT) (79 eV). Above the DIT, these states are the double continuum states; below, they are the double excited states. These two types of states are tightly coupled to the single continuum states with or without excitation of the residual ion He{sup +}, owing to their degeneracy in energy. In a one-photon process, these states can only be formed owing to the electronic correlations in the system which must be well described to obtain quantitative good results. Our study is a part of the work which aims at a united description of all these doubly excited, ionized-excited, and double continuum states. We use the Hyperspherical R-Matrix with Semiclassical Outgoing Waves (HRM-SOW) method, initially dedicated to double photoionization studies. We extend it to extract information on the single continuum. This ...
This dissertation deals with the control of active power flow, or load flow in electric power systems. During the last few years, interest in the possibilities to control the active power flows in transmission systems has increased significantly. There is a number of reasons for this, coming both from the application side - that is, from power system operations - and from the technological side. where advances in power electronics and related technologies have made new system components available. Load flow control is by nature a multi-input multi-output problem, since any change of load flow in one line will be complemented by changes in other lines. Strong cross-coupling between controllable components is to be expected, and the possibility of adverse interactions between these components cannot be rejected straightaway. Interactions with dynamic phenomena in the power system are also a source of concern. Three controllable components are investigated in this thesis, namely the ...
This paper is dedicated to the numerical study of natural ventilation in a room through a large external opening using the CFD code Fluent. Bidimensional numerical simulations are performed for wind speeds up to 5.55 m-s{sup -1} (20 km-h{sup -1}). We propose a two-step solution procedure with grid refinement. When combined with appropriate thermal boundary conditions, this technique appears very efficient at limiting local convergence problems. Through an analysis of the flow pattern in the cavity, we qualitatively explain those results and define a critical Archimedes number. Calculated air change rates are compared to values deduced from empirical correlations of the literature. Agreement is in general poor, which can be explained by the differences between the conditions of our simulations and those of the experiments that lead to those correlations. However, from our simulations, we derived very clear correlations between the air change coefficient and the Archimedes number. In the ...
The aim of this work is to be able to describe transformations, occurring when solids and gases are in non isothermal and non isobaric conditions, with kinetic models. A methodology has been used. Two essential processes have to be taken into account: the germination and the growth. The germs are supposed to be formed (at constant temperature and pressure) in the grains surface with a constant velocity by surface unit, (gamma), called germination surface frequency (number of germs.m{sup -2}.s{sup -1}. The growth velocity is characterized by a growth surface reactivity, (phi) (in mol.m{sup -2}.s{sup -1}). With an appropriate transformation model, it is possible to obtain the variations of (gamma) and (phi) in terms of the temperature and pressure which are then used in the calculation of the velocity in non isothermal and non isobaric conditions. In order to validate the developed method, two reactions have been studied. For the first one, the kaolinite de-hydroxylation, an anisotropic ...
Due to its important hydroelectric power generation facilities (about 525 plants with a total power of 13,314 MW producing about 35.3 TWh annually) Switzerland plays an important role in the interconnected European power system. Large artificial storage lakes in the Swiss Alps can generate peak power during hours of highest demand: 9700 MW are available from accumulated energy and the total power of pumped-storage facilities amounts to 1700 MW. The latter allow refilling the reservoirs at periods of low power demand and generating power at periods of peak demand. In the case of favorable conditions, the yearly average power production could be increased by 6% and the production during the winter period (October to March) by 20% by the year 2020. However, looking forward to the year 2050, the annual production is expected to decrease by 3% despite a possible extension of hydropower. This decrease is due to the enforcement of the minimum residual water flow rates required by a new ...
The electrochemical intercalation of non-solvated lithium in different graphited materials has been performed in LiClO{sub 4}-ethylene carbonate (EC) medium. The irreversible capacity observed during the first output is mainly due to the formation of a passivation layer made of electrolyte reduction products. These products have been characterized for different electrode reduction potentials using transmission electron microscopy (image, diffraction) and electron energy loss spectroscopy (EELS). EC reduction on the electrode surface in presence of LiClO{sub 4} leads to the formation of Li{sub 2}CO{sub 3} for potentials close to 0.8 V vs Li{sup +}/Li. For lower potentials, the electrolyte reduction reaction goes on with the formation of different lithium alkyl-carbonates. In LiClO{sub 4}-propylene carbonate (PC) medium, the interface phenomena are different. The reduction of a graphite electrode is characterized by the exfoliation phenomenon which hinders lithium intercalation. On the ...
One of the Eddy Current Testing issues in aeronautics is the inspection of fastened structures to detect flaws nearby rivets which can grow because of mechanical stress. EADS and the CEA LIST have started a collaborative work with the support of the Ile-de-France Region to develop a simulation tool of EC fastened structures testing, integrated to the CIVA platform, aimed at conceiving testing methods, optimizing and qualifying it. The volume integral method using the Green dyadics formalism has been chosen in order to get a fast resolution of Maxwell equations. A first milestone was to build a simulation model of multilayer structures testing, thanks to the use of the multilayer Green dyads. Because of the rivet volume, 60 times bigger than the one of a typical flaw, a large number of discretization cells are needed. Therefore an iterative method has been developed in order to numerically solve large calculation zones. Finally, the flaw response simulation mostly has to cope with a ...
As the jump from 2D to 3D, seismic exploration lives a new revolution with the use of converted PS waves. Indeed PS converted waves are proving their potential as a tool for imaging through gas; lithology discrimination; structural confirmation; and more. Nevertheless, processing converted shear data and in particular determining accurate P and S velocity models for depth imaging of these data is still a challenging problem, especially when the subsurface is anisotropic. To solve this velocity model determination problem we propose to use reflection travel time tomography. In a first step, we derive a new approximation of the exact phase velocity equation of the SV wave in anisotropic (TI) media. This new approximation is valid for non-weak anisotropy and is mathematically simpler to handle than the exact equation. Then, starting from an isotropic reflection tomography tool developed at Lt-'P, we extend the isotropic bending ray tracing method to the anisotropic case and we ...
To accomplish the environmental radiological surveillance need of India's ambitious nuclear power programme, Health Physics Division is infusing new technologies and improved analytical techniques for day to day measurements of various radionuclides in different environmental matrices. It is essential to have techniques for measuring the concentration of radionuclides just above the background level since the discharges from the nuclear facilities are very low i.e. in the range of 5-10% of the prescribed discharge limits by the regulatory bodies. In view of developing ultra-sensitive techniques, the aim of ongoing programmes of the division is to meet the challenges of measuring ultra trace level of radioactivity by adopting state of art new instrumentation and improved sample processing techniques. This will allow us to measure the lowest level of radioactivity (3H, 90Sr, 137Cs, 239+240Pu, etc.) in the environment and thereby estimating the lowest doses to the members of public. ...
Results are presented from a series of studies conducted at the Department of Energy (DOE) Savannah River Plant (SRP) with the NASA Airborne Oceanographic Lidar (AOL). These studies included a topographic survey of a {approximately}1000 acre lake basin (presently designated L Lake) which had been excavated for use as a cooling pond for L Reactor; a study of the movement of discharged cooling water in Pond C and the warm arm of Par Pond using Rhodamine WT dye as a tag; initial baseline studies of the vegetation cover of the Steel Creek corridor (through which the outflow of L Lake is carried to the Savannah River); and a demonstration of potential forestry applications of the AOL. These investigations were conducted over a 3-day period in June 1985. The AOL is an advanced airborne laser system capable of making temporal or time history measurements of laser backscatter (bathymetry mode) or spectral measurements of laser induced fluorescence from waterborne ...
Magnetic resonance imaging (MRI) as a diagnostic imaging tool relies on the generation of magnetic fields, whereas the computerized tomography (CT) uses X-radiation. The fundamental principle of MRI is the magnetic resonance of paramagnetic atomic nuclei. These nuclei, as e.g. protons (= hydrogen nuclei), are aligned in required orientation by application of a strong magnetic field. Upon simultaneous application of an electromagnetic high-frequency field perpendicular to the axis of the basic magnetic field, and in response to periodical changing of the electromagnetic field at a given frequency, the originally aligned paramagnetic nuclei are forced into a movement similar to that of a ``whipping top``. When the resonance frequency is shut off, the nuclei return to their former, aligned positions, inducing a weak signal in a coil. The series of signals generated by multiple repetition of this process of excitation of nuclei and their return to aligned rest is used as input to a ...
{gamma} Ti-Al have a higher temperature potential than commercial titanium alloys and a 50 percent lower density than nickel base superalloys. Application temperatures in aircraft turbines are 750 C and above. The authors investigated the high-temperature performance of {gamma} TiAl, i.e. isothermal high-temperature fatigue and the type and importance of damage. LCF experiments were made in the temperature range of brittle/ductile transition in air and vacuum. Damage mechanisms were characterized by microstructural investigations. [German] Unter den modernen Hochtemperaturwerkstoffen kommt den Legierungen auf Basis von {gamma}-TiAl eine zunehmend wichtige Bedeutung zu, da diese Werkstoffe ein hoeheres Temperaturpotential als alle kommerziellen Titanlegierungen haben und eine im Vergleich zu den Nickelbasis-Superlegierungen um ca. 50% geringere Dichte aufweisen. TiAl-Werkstoffe, die z.B. fuer Schaufeln und Gehaeuse in Flugzeugturbinen eingesetzt werden sollen, ...
The further optimisation and improvement of the efficiency of internal combustion engines require the realisation of new technologies leading to a distinctively faster warm-up behaviour of the coolant and lubricants as well as of the engine components after a cold start. In order to achieve reduced fuel consumption and exhaust gas emissions with the help of heat management, the design criteria of innovative cooling systems need to be reflected and adapted to future requirements. The use of intelligent components within the cooling system, such as the 'Stand Alone Rotary Valve' as a thermostat's substitute or the use of coolant pumps with a rotary valve integrated into the pump's inlet chamber, offer new ways to realise in a decisively quicker and more flexible way the appropriate heating up and cooling down procedures at varying driving conditions. A description of both of the intelligent components for the cooling system is given in this paper. The ...
This assessment is a feasibility study according to ISO 14024. It deals with the question whether an ecolabel is suitable for wood pellet heating systems and how concrete criteria for an ecolabel for wood pellet heating plants could be specified. The study begins with a comprehensive market analysis in order to identify possible plants for which an ecolabel would make sense. In the main part of the study, the environmental relevance of the chosen plants is analysed. For this analysis, plant manufacturers were interviewed and a comparison between wood pellet heating systems and heating systems which use gas, oil or wood was carried out. On the basis of this analysis, it was possible to derive a number of criteria which were discussed with company representatives and other experts in this field. As a result of this dialogue and the investigation process as a whole, the introduction of an ecolabel for wood pellet heating plants can be recommended. Wood pellet heating systems are ...
The responses of ramets of hybrid poplar (Populus spp.) (HP) clones NE388 and NE359, and seedlings of red maple (Acer rubrum, L.) to ambient ozone (O_3) were studied during May-September of 2000 and 2001 under natural forest conditions and differing natural sunlight exposures (sun, partial shade and full shade). Ambient O_3 concentrations at the study site reached hourly peaks of 109 and 98 ppb in 2000 and 2001, respectively. Monthly 12-h average O_3 concentrations ranged from 32.3 to 52.9 ppb. Weekly 12-h average photosynthetically active radiation (PAR) within the sun, partial shade and full shade plots ranged from 200 to 750, 50 to 180, and 25 to 75 #mu#mol m"-"2 s"-"1, respectively. Ambient O_3 exposure induced visible foliar symptoms on HP NE388 and NE359 in both growing seasons, with more severe injury observed on NE388 than on NE359. Slight foliar symptoms were observed on red maple seedlings during the 2001growing season. Percentage of total leaf area ...
The activity concentrations of potassium, uranium and thorium in minerals and soil samples from a mining site in Ibadan, Southwestern Nigeria were measured using gamma ray spectroscopy method. Effective dose per annum has been calculated from the activity concentrations of dominant gamma-emitting natural radionuclides, potassium, uranium and thorium. Samples collected include minerals (beryl, quartz and feldspar), soil samples from the mining pits, heaps and undisturbed land around the mining site. The activity concentrations of {sup 40}K, {sup 238}U and {sup 232}Th, respectively in Bq kg-1 in the mineral samples were as follows: 1985 +- 16, 4.8 +- 0.9 and 11.8 +- 5.8 for beryl sample, 115.1 +- 27.9, 5.0 +- 1.3 and 6.3 +- 5.0 for feldspar samples and 1421 +- 122, <4.8 and 20.1 +- 3.5 for quartz samples. For the soil samples, the mean activity concentrations of {sup 40}K, {sup 238}U and {sup 232}Th, respectively, were 314.2 +- 5.7, 27.7 +- 2.6 and 11.5 +- 5.9 Bq kg-1 for soil ...
Physico-chemical characterizations performed on samples of 100Cr6 steel implanted both with boron and nitrogen revealed the formation of boron nitride along with the following new phases: Fe{sub 1-x}(B, N), Fe{sub 2-x}(B, N) and Fe{sub 3-x}(B, N). A thorough analysis of boron NITRIDE (5BN) indicates that a low ion current density (3 {mu}A.cm{sup -2}) in the case of the boron plus nitrogen sequence favours the formation of sp{sup 2} bonds (hexagonal-BN) while a higher ion current density (6{mu}A.cm{sup -2}) promotes sp{sup 3} bonds (cubic-BN) in the opposite sequence. Tribological tests carried out on these samples revealed that nitrogen and boron implantations do not lead to any significant improvement of friction and wear at variance with the results obtained by others authors. However, on a set samples accidentally contaminated with carbon during implantation, we noticed a considerable improvement of these tribological parameters. As this pollution is commonly encountered in surface ...
Damage survey of protective coats of modern gas turbine blade shows that most damages are not due to classic wear mechanisms such as oxydation or high-temperature corrosion but caused by foreign bodies, poor coating during manufacturing, or operation-caused cracks. Mere visual inspection of cracks is often not sufficient to tell whether cracks are superficial or whether they have already progressed into the base material. Non-destructive methods such as ultrasonic inspection or eddy-current testing are helpful tools but there is not yet a fully matured testing concept at hand. Metallographical tests can give important information about crack mechanisms and thermal, chemical and mechanical stresses.(orig.) [German] Die Schadenerfahrung mit Schutzschichten moderner Gasturbinenschaufeln zeigt, dass die meisten Schaeden nicht auf die klassischen Verbrauchsmechanismen wie Oxydation und Hochtemperaturkorrosion zurueckzufuehren sind, sondern durch Fremdkoerper, herstellungsbedingte ...
The interdiffusion behaviour of MCrAlY-coats on polycrystalline and single-crystalline materials of a similar composition (IN 738 LC/SC 16)shows similar interdiffusion characteristics. TCF-tests, where stress is generated by temperature and sample geometry at the edges of a disk-shaped sample, show that it is possible to differentiate betwee crack resistance of coated and uncoated samples. This method is also suitable for screening tests with different coat thicknesses. Coating of the edge area must, however, be done with great diligence in order to prevent coat thickness variation as results would then not be reproducable. Contrary to TCF (thermal cycle fatigue) TMF-tests (thermal mechanical fatigue)allow to set the stress states that one wishes to test. This method is therefore well suited for testing under operating conditions.(orig.) [German] Im Rahmen dieser Arbeit wurde gezeigt, dass das Interdiffusionsverhalten von MCrAlY-Schichten auf polykristallinen bzw. ...
The nozzle-group regulation of steam turbines plays furtheron an important role in the operation of power stations owing to modern, adaptable control-technical valve timing possibilities. New procedures for a choice-connection of different nozzle areas via the control valves as well as the use of valve laps require, however, a differentiated consideration of the loss mechanism in the inlet area of the turbine, in order to be able to assess and minimize its specific heat consumption also at the operational points outside the layout- and calculation-technically fixed guarantee or valve points, respectively. The basic technical-physical stages to this are explained. (orig.) [Deutsch] Die Duesengruppenregelung von Dampfturbinen nimmt nicht zuletzt dank moderner, anpassungsfaehiger leittechnischer Ventilansteuerungsmoeglichkeiten weiterhin eine bedeutende Stellung beim Betrieb von Kraftwerken ein. Neue Verfahren zur wahlweisen Zuschaltung unterschiedlicher Duesenflaechen ueber die ...
It is demonstrated that highly dispersed molybdenum sulfide catalysts are prepared by using Mo(CO){sub 6} adsorbed on the support. The structure of ultradispersed molybdenum sulfide is suggested by EXAFS techniques to be different from that of MoS{sub 2}. The TOF of the thiophene HDS is almost invariant with the dispersion of molybdenum sulfide at a high molybdenum dispersion, whereas the TOF of the hydrogenation greatly increases with increasing dispersion. On the basis of the HDS activity and optimum Co/Mo ratio of Co-Mo/Al{sub 2}O{sub 3} catalysts having a variety of molybdenum dispersion fabricated by using carbonyl complexes, it is demonstrated that highly active HDS catalysts are prepared by highly dispersing molybdenum sulfide phases. Edge decorations of molybdenum sulfides by cobalt are suggested for the synergy generation between cobalt and molybdenum sulfides. (orig.) [Deutsch] Unter Verwendung von auf dem Traeger adsorbierten Mo(CO){sub 6} lassen sich hochdispergierte ...
Blades of modern steam turbines are designed for high efficiency and operational safety. Modern computer programs enable optimisation of design but factors like manufacturing, assembly, operation and downtimes still play an important role. Damage statistics show that blade damage still quite frequent. Selected cases from the Allianz damage assessment centre show some of the more frequent damage mechanisms. Damage is often caused when several factors come together. Prevention of follow-up damage requires early identification of beginning damage.(orig.) [German] Die Auslegung der Beschaufelung moderner Dampfturbinen hat die Vorgabe, einen hohen Wirkungsgrad bei gleichzeitig hoher Betriebssicherheit zu erreichen. Mit den heute zur Verfuegung stehenden Rechenprogrammen ist eine entsprechende Optimierung realisierbar. Fuer die langzeitige Betriebsbewaehrung haben aber Einflussgroessen aus Fertigung, Montage, Betrieb und Stillstand auch heute noch die gleiche Bedeutung wie in der ...
The aim of the study was to establish by means of a measuring programme how much energy for space heating can be saved by the installed hybrid system. Further, experience with the systems was to be gathered under practical use conditions. As user behaviour can influence space heating energy consumption to an extent having several times the effect of the contribution of the hybrid system, a fact that is also reported in literature, it is not sufficient to measure only space heating energy consumption. So, a unit in one of the terraced houses was scrupulously measured. In the three other terraced houses, only space heating energy consumption was measured.- This final report contains not only a description of the concepts of the buildings and hybrid system but also the energy consumptions measured, and detailed analyses of the budgets. (orig./AKF) [Deutsch] Mit Hilfe eines Messprogrammes sollte ermittelt werden, welche Heizwaermeeinsparung durch das installierte Hybridsystem praktisch ...
Heat pumps for residential space heating become an increasingly important alternative to the conventional heating system like gas or oil burner. They offer the opportunity to reduce CO{sub 2} emission associated with heating residential homes in Germany. High compressors efficiency and a wide operating map are required so that an economically viable heat pumps is achieved which meets the operational conditions for present and future heating systems. The design parameter of existing heating systems require relatively high condensing temperatures which can be achieved with dedicated compressor designs. The design of Scroll compressors specially adapted to these heat pumps is shown and their operation is explained. (orig.) [German] Waermepumpen fuer die Wohnraumheizung gewinnen an Bedeutung als Alternative zur konventionellen Gas- oder Oelheizung. Sie bieten die Moeglichkeit, die mit der Gebaeudeheizung verbundene Emission von Kohlendioxid in Deutschland zu reduzieren. Ein hoher ...
With the development of the latent heat store and its inclusion in the conventional heating control of cars, success has been achieved both in increasing comfort and in making an important contribution to safety of driving. Great store is set in development of the system on its environmental friendliness, for example by the thorough use of environmentally friendly and reusable materials. This also means the use of clean materials. It was shown that the latent heat store (apart from the aspects of comfort and safety of driving) can also make a contribution to saving fuel and reducing the exhaust gas. The sum total of the advantages makes it clear that the latent heat store introduced here is a very environmentally friendly system with multi-functional properties. (orig.) [Deutsch] Mit der Entwicklung des Latentwaermespeichers und seiner Einbindung in die konventionelle Heizungsregelung von Automobilen ist es gelungen, sowohl den Komfort deutlich zu erhoehen als auch einen wichtigen ...
The position paper will provide the basis for further strategies on offshore wind power development in consideration of ecological and conservation aspects. [German] Das Positionspapier des Bundesministeriums fuer Umwelt, Naturschutz und Reaktorsicherheit (BMU) einschliesslich des Umweltbundesamtes (UBA) und des Bundesamtes fuer Naturschutz (BfN) ist Ergebnis der Arbeiten der BMU-Projektgruppe 'Windenergienutzung im Offshore-Bereich im Hinblick auf die BMU-Anliegen'. Es beschreibt den derzeitigen Stand einer Strategie zur umwelt- und naturvertraeglichen Erschliessung der Windenergienutzung auf See (Offshore). Es bildet die Grundlage fuer die Weiterentwicklung dieser Strategie und dabei insbesondere zur Abstimmung mit den Anliegen anderer Bundesressorts und den Kuestenlaendern, sowie zur intensiveren Einbeziehung beteiligter Verbaende und Fachkreise. Vor dem Hintergrund der zur Genehmigung eingereichten Antraege fuer Offshore-Windparks, mangelnder Erfahrung der ...
More than two and a half years of monitoring of a passive house school and day-care centre in Frankfurt a. M. show comfortable indoor climate and good air quality. The space heat consumption is low and shows savings of approximately 90 % as compared to average existing schools. Excellent performance was also achieved in terms of primary energy. The results of further analyses of the efficient ventilation system with heat recovery, the perimeter insulation as an alternative to floor slab insulation and the influence of the air change due to the entrance door are presented. (Abstract Copyright [2008], Wiley Periodicals, Inc.) [German] Ueber zweieinhalb Jahre Monitoring einer Passivhaus-Schule und Kindertagesstaette (KiTa) in Frankfurt a.M. zeigt behagliche raumklimatische Bedingungen bei guten Luftqualitaeten. Die Heizwaermeverbrauchswerte liegen wie erwartet niedrig und zeigen Einsparungen um 90 % gegenueber dem Durchschnitt im Bestand. Auch primaerenergetisch ...
About 25 years after the last edification of a new large high voltage institute at Technical University of Karlsruhe and about 10 years afte the edification of the test lab at Kaiserslautern University, the Brandenburg Technical University of Cottbus had the opportunity to design new high voltage test facilities from the very beginning on and to realize it in a very short time. To review the project from the first ideas followed by the planning and realization phase and the final commissioning of the technical equipment, this book should be a contribution to spred the experiences made among interested people and to demonstrate the actual technical possibilities. To ensure an international exchange of these experiences, all co-authors to the trouble to translate their participation's also to the English language. (orig.) [German] Etwa 25 Jahre nach dem letzten grossen hochspannungstechnischen Institutsneubau in der deutschen Hochschullandschaft an der TH Karlsruhe, bzw. 10 ...
The purpose of the present study was to examine reactions between bromium atoms with {alpha}, {beta}-unsaturated carbonyls. Acrolein, methacrolein, and methyl vinyl zetone were chosen as representatives of this family. The latter two compounds, beside formaldehyde, belong to the main products of atmospheric oxidation of isoprene and have been detected in the troposphere at concentrations of up to almost 1 ppb. It is known that alkenes react with bromium via addition to form an instable adduct. This product can either decompose again into its educts or react with molecular oxygen. The aim of the study was to determine the velocities of the reactions between the three {alpha}, {beta}-unsaturated carbonyls and bromium and to clarify the involved reaction mechanisms by means of kinetic experiments and product analyses. (orig./SR) [Deutsch] In dieser Arbeit wurde die Reaktion von Bromatomen mit {alpha}, {beta}-ungesaettigten Carbonylen untersucht. Ausgewaehlt wurden Acrolein als einfachster ...
CNG vehicles suffer from an uncontrolled temperature rise of the gas inside the tank during the filling process and heat exchange with the environment leads to variable filling levels. A partly filled tank reduces the range of CNG vehicles and works as a impediment to the spreading of environmentaly more friendly CNG vehicles. The increase of the pressure inside the tank combined with a prolongation of the filling time beyond three minutes can reduce the deficit of the filling process. For economic reasons the time required for refuelling should be as short as possible without the need to operate the filling station with a critical pressure. To meet this target the current technique requires further improvement. (orig.) [Deutsch] Die betriebliche Praxis bei Tankvorgaengen von Erdgasfahrzeugen zeigt, dass waehrend des Tankvorganges die Temperatur des getankten Erdgases im Fahrzeugtank ansteigt. Waehrend und nach Beendigung des Tankvorganges findet ein Temperaturausgleich mit der ...
A process model is presented and used for identifying options for controlling the cupola furnace process and for investigating natural gas substitutes. Fuel substitution will affect temperature curves (i.e. tapping temperatures and melting capacity), outlet temperatures and gas mass flow out of the preheating zone. The contribution presents several process variations to overcome these problems and compares them with the natural gas process. [German] Mit dem Prozessmodell werden zunaechst Moeglichkeiten der Steuerung von Abstichtemperatur und Schmelzleistung, insbesondere unter Beruecksichtigung der Schrottqualitaet (spezifische Oberflaeche a{sub G}), untersucht. Es wird gezeigt, dass das Prozessmodell die Ergebnisse aus der Praxis wiedergibt. Daran anschliessend wird mit dem Prozessmodell die Substitution von Erdgas durch minderwertige Gase untersucht (Brennstoffsubstitution, Ressourcenschonung). Durch die Brennstoffsubstitution veraendern sich die Temperaturverlaeufe und damit auch ...
Molybdenum is an essential element for living organisms. Moreover its radionuclides may represent an incorporation risk for members of the public and/or radiation workers after a nuclear accident or a release of radioactive materials. However, only few reliable data on Mo biokinetics in humans were available. The results of recent tracer kinetic investigations with stable isotopes have shown several differences from the ICRP data with regard to the processes of intestinal absorption and of excretion. As a consequence, the dose coefficients calculated with a revised biokinetic model deviate from the ICRP estimates. By ingestion of {sup 99}Mo radionuclides with solid food, for example, the dose to the colon may be higher of a factor up to 1 order of magnitude, due to the fraction of non-absorbed material which traverses the gastro-intestinal tract. (orig.) [Deutsch] Molybdaen ist einerseits ein fuer Lebewesen essentielles Spurenelement, andererseits koennen radioaktive Mo-Isotope im ...
Metal hydrode stores are used as fuel tanks in vehicles or as stationary stores of high-purity hydrogen. Equilibrium isotherms at low pessures were measured in order to validate the laws of Henry or Sievert for hydrogen uptake of the alloy Ti{sub 0.98}Zr{sub 0.02}V{sub 0.43}Fe{sub 0.09}Cr{sub 0.05}Mn{sub 1.5} (patented by Daimler Benz AG, code DB5800). The laws were to provide information on whether hydrogen uptake is atomic or molecular and on the conditions in which isothermal measurements are possible. (orig.) [Deutsch] Metallhydridspeicher werden als Kraftstofftank in Fahrzeuge oder als stationaere Speicher zur Bereitstellung von Reinstwasserstoff verwendet. Fuer diese Arbeit wurden die Gleichgewichtsisothermen bei kleinen Druecken vermessen, um die Gesetze von HENRY oder SIEVERT fuer die Wasserstoffaufnahme in der Legierung Ti{sub 0.98}Zr{sub 0.02}V{sub 0.43}Fe{sub 0.09}Cr{sub 0.05}Mn{sub 1.5} zu pruefen. Anhand dieser Gesetze ist zu entscheiden, ob die ...
In order for fuel cells to be successful, a full-scale hydrogen infastructure is required. The HyTra concept is presented here (HYdrogen TRAnsform, Transfer and TRAnsport) involves combined production, storage and supply of hydrogen in a transportable trailer, i.e. it is both a hydrogen production unit and a mobile filling station. The trailer can be transported to the selected site, where it will produce gaseous hydrogen from electricity and water by electrolysis. A compressor pumps the gas into an internal pressure tank and compresses it to filling pressure. Filling takes place by the overflow principle via a flexible high-pressure line with a standardised H{sub 2} filling unit. (orig.) [German] Um die Marktdurchdringung der Brennstoffzellentechnik gewaehrleisten zu koennen, muss eine flaechendeckende Wasserstoffinfrastruktur aufgebaut werden. Das neue HyTra-Konzept (HYdrogen TRAnsform, TRAnsfer and TRAnsport) beruht auf der Kombination von Wasserstoff-Erzeugung, ...
The composition of alkaline and neutral boric acid containing evaporator concentrates resulting from the treatment of radioactive waste water in nuclear power plants with WWER reactors is described as well as the processing of these concentrates to a product suitable for final disposal. Tests with mock solutions of these evaporator concentrates have been performed at the laboratory and teststand scale to produce a dry residue by continuous thickening, which can be processed into a highly leach resistant product, suitable for final disposal, by cementation. Ca-compounds must be added to the evaporator concentrates prior to the drying in an rotary thin-film evaporator (RTFE). The tests showed that neutral evaporator concentrates can be dried in a RTFE with addition of small amounts of Ca-compounds. The alkaline evaporator concentrates with high boric acid and total salt load require a multiple amount of Ca-compounds and diluting water to perform the drying process. A brief description of ...
The externally fired combined cycle (EFCC) process utilises a high temperature heat exchanger to transfer the heat of a dirty flue gas to a clean working medium. In comparison to other combined cycle concepts, like integrated gasification combined cycle or pressurized pulverized coal combustion, the problems of hot gas cleaning are avoided. The first part of the publication (BWK 5/02) deals with the possible concepts and the efficiency potential of the externally fired combined cycle. The applicability of metallic and ceramic heat exchanger materials are discussed. The second part summarizes the state of the art and presents the basic design of a ceramic heat exchanger. [German] Der extern gefeuerte Gasturbinenprozess arbeitet mit einem Waermeuebertrager, um ein Arbeitsmedium auf Gasturbineneintrittstemperatur zu erhitzen. Im Vergleich zu Kombiprozessen mit integrierter Kohlevergasung oder Druckkohlenstaubfeuerung entfaellt damit die Heissgasreinigung. Der erste ...
The externally fired combined cycle (EFCC) process utilises a high temperature heat exchanger to transfer the heat of a dirty flue gas to a clean working medium. In comparison to other combined cycle concepts, like integrated gasification combined cycle or pressurized pulverized coal combustion, the problems of hot gas cleaning are avoided. The first part of the publication deals with the possible concepts and the efficiency potential of the externally fired combined cycle. The applicability of metallic and ceramic heat exchanger materials are discussed. The second part (BWK 6/02) summarizes the state of the art and presents the basic design of a ceramic heat exchanger. (orig.) [German] Der extern gefeuerte Gasturbinenprozess arbeitet mit einem Waermeuebertrager, um ein Arbeitsmedium auf Gasturbineneintrittstemperatur zu erhitzen. Im Vergleich zu Kombiprozessen mit integrierter Kohlevergasung oder Druckkohlenstaubfeuerung entfaellt damit die Heissgasreinigung. Der ...
Several technological alternatives have been studied taking into consideration that one of the biggest problems of the electric power companies is to provide electric power during the peak consumption periods, which largest contribution to the increase of the demand comes from the residential sector, especially by the use of electric showers. One of the most promising alternatives is the pre-water heating system for reduced power showers, developed by Universidade de Campinas and Companhia Paulista de Forca e Luz. The goal of this system is basically to reduce demand during the peak periods, in order to avoid heavy investments by the electric power companies in generation, transmission and distribution of electric power directed to low acquisitive power customers, a sector in which the electric power price is not enough to recover such investments. The objective of this paper is to evaluate the total energy required in the construction of one of these systems and compare it to the ...
Magnetic resonance imaging (MRI) in stroke makes it possible to visualize the initial infarct in cases of acute cerebral ischemia. Perfusion MRI serves to determine which tissues are additionally at risk of infarction due to persistent hypoperfusion. MRI also allows those examiners with limited experience to reliably confirm an infarct. The most important differential diagnosis of cerebral ischemia, intracerebral hemorrhage, can likewise be recognized with certainty using MRI. Although diffusion and perfusion MRI only demonstrate the pathophysiology of cerebral ischemia approximately, the method is suited for identifying those patients who would profit from reperfusion therapy. Whether MRI is also appropriate as an aid to reaching a prognosis on the risk of secondary hemorrhage has not yet been resolved. (orig.) [German] Die Schlaganfall-MRT ermoeglicht es, bei akuter zerebraler Ischaemie den bereits initial entstandenen Infarkt darzustellen. Mittels Perfusions-MRT kann erfasst werden, ...
The distribution of graphite particles in graphite containing copper alloy was further improved very significantly using several procedures and technological modifications. The developed techniques attacked the graphite distribution problem in two ways. Realizing that clustering of very fine (5um) graphite particles is one of the two major problems, a pretreatment process has been developed using aluminum powders to deagglomerate graphite particles. Along with this, a two-stage stirring technique was used to first incorporate and then to distribute uniformly the deagglomerated particles in the melt. During this year, based on these developments, several components were cast to evaluate the castability of Cu alloy-graphite melts. In addition, machinability tests were done to clearly established that addition of graphite particles improve the machinability of copper MMC alloys over and above that of monolithic copper alloys. The results show that the machining chip ...
Shortened excerpt from the head notes: The emission limits laid down in the TA Luft concretize the scope of the measures ordered by the law to provide for protection against harmful effects on the environment. Air pollution abatement measures imposed by the competent authority as post-licensing requirements based on the BImSchG (German Federal Emission Control Act) in general are in compliance with the principle of reasonableness considering the terms allowed by the TA Luft for backfitting measures. With this decision, the court qualified the emission limits defined in the TA Luft to be substantial and legally binding standards, to be applied by the competent authorities in licensing and post-licensing administrative procedures, also in order to fulfill the intended task of concretizing the less definite concepts of law laid down in the relevant legislation. (orig./CB) [Deutsch] Verkuerzte Zitierung aus den Leitsaetzen: Die in der TA Luft aufgestellten emissionsbegrenzenden ...
The results of the creep performance studies at temperatures from 700-1000 C with welds of alloy 800 HT, the manual shielded metal arc welds made with Githerm 85 and Grini 209 filler metals, as well as the MIG pulsed arc welds made with the Nicrofer S 206 and Nicrofer S 5520 filler metals, proved to be in very good agreement with the calculated characteristic values published on VdTUeV sheet 434 in comparative assessments based on creep values valid for a service period of 10 000 hours. The MIG pulsed arc weld made with the Nicrofer S 5520 filler metal achieved by far the best results and strength values comparable to those of the base material, whereas the values of the other welds were corresponding to calculated strength values of the base material reduced by 20%. (orig./CB) [Deutsch] Die im Temperaturbereich von 700-1000 C an Alloy 800 HT und den Elektrodenhandschweissverbindungen mit den Schweisszusaetzen Gritherm 85 und Grini 209, sowie den MIG-Pulsed-Arc-Schweissungen mit den ...
Experiments for lifetime prediction of the first wall are being carried out within the framework of the European fusion reactor programme. Defects such as notches and cavities may develop in the first wall and may initiate under cyclic thermal stress cracking processes which may reduce the service life of the material. For examination of crack growth, specimens with defined initial notches were prepared and subjected to cyclic thermal loads. The paper shows that the eddy current method is suitable for detecting and revealing the crack growth processes even under conditions of complex geometry, as e.g. cracks in inner bores. The experiments indicated particularly susceptible, critical spots in the first wall and yielded crack growth rates of use for lifetime calculations. (orig./CB) [Deutsch] Im Rahmen des europaeischen Fusionsreaktorprogramms werden Untersuchungen zur Lebensdauervorhersage der Ersten-Wand durchgefuehrt. Die Erste-Wand kann Fehler in Form von Lunkern und Kerben ...
Pulmonary infections and tumors are a major cause of death in patients with AIDS. The combination of clinical, radiological, laboratory, and pathohistological data helps to narrow the spectrum of differential diagnoses or even allows a specific diagnosis in many patients. Nevertheless, an accurate diagnosis should be obtained as soon as possible during the clinical course of the illness to initiate treatment in time. Computed tomography (CT) has proven to provide promising results in the diagnosis of AIDS-related throacic diseases. The aim of this paper was to demonstrate the diagnostic capacities of CT in the context of particular AIDS-related thoracic pathologies. Additional information on the spectrum of pathological agents and on differential diagnostic signs is summarized. (orig.) [Deutsch] Pulmonale Infektionen und Tumore sind eine wesentliche Todesursache bei Patienten, die am erworbenen Immunmangelsyndrom AIDS leiden. In den meisten Faellen gelingt es, durch Zusammenschau ...
Isothermal reaction experiments were performed in the temperature range of 1000 - 1300 C in order to determine the chemical interactions between Zircaloy-4 fuel rod cladding and Inconel-718 spacer grids of Pressurized Water Reactors (PWR) under severe accident conditions. It was not possible to apply even higher temperatures since fast and complete liquefaction of the components occurred as a result of eutectic interactions during heatup. The liquid reaction products formed enhance and accelerate the degradation of the material couples and the fuel elements, respectively. Only small amounts of Inconel are necessary to liquefy large amounts of Zircaloy. Thin oxide layers on the Zircaloy surface delay the beginning of the chemical interactions with Inconel but cannot prevent them. In this work the reaction kinetics have been determined for the system: as-received and pre-oxidized Zircaloy-4/Inconel 718. The interactions can be described by parabolic rate laws; the Arrhenius equations for ...
The effect of the heavy particle irradiation on cell survival is different from that of X-ray irradiation. In Japan, heavy particles will be applied to cancer patients in the near future. This study was performed to determine the effect that carbon particle irradiation exerts to human monolayer cells in vitro, in comparison with the effect of 200 kVp X-ray. Two human cell lines, HeLaS3 and RMUG, were used. The irradiation was carried out by the RIKEN ring cyclotron and 200 kVp X-ray. The experimental procedure is explained. Also split dose experiment was carried out by applying equally divided doses at intervals of 2 - 4 hours. The Bragg curve of 135 MeV/n carbon beam through the lucite plates with different thickness is given. Thus the different LETs were obtained. The survival curves for 200 kVp X-ray and the various LETs of carbon beam are shown. The curves became steeper, and Do values decreased with increasing LETs in both cell lines. The relative biological effect (RBE) at 10% ...
Two spreading experiments were performed at the FARO facility with prototypical core melts of a UO{sub 2}/ZrO{sub 2} weight percentage of 80/20. The objective was to obtain data on the spreading at flow rates of about 2 l/s of more than 100 kg prototypic high temperature oxide melt on a dry and wet stainless steel plate. For the second spreading test a shallow water layer of 10 mm was added on the substrate. Solutions for an isothermal spreading with a constant volume flux boundary condition in a sector with an angle {phi} are used to analyse the FARO L-32S experiment and to identify the source of discrepancies between the code results (THEMA, CORFLOW) and the experimental findings. The observed spreading behaviour of both FARO experiments can only be explained if an initial melt temperature below the liquidus temperature, i.e. about 120 K lower than the temperature measured by the UTS sensors is assumed. (orig.) [German] Zwei Ausbreitungsexperimente mit einer UO{sub 2}/ZrO{sub 2} ...
Tumours lesions of the temporal bone and of the cerebello-pontine angle are rare.This tumours can be separated into benign and malignant lesions. In this paper the CT and MRI characteristica of tumours of the temporal bone and the cerebello-pontane angle will be demonstrated. High resolution CT (HRCT) as usually performed in the axial plane are using a high resolution bone window level setting, coronal planes are the reconstructed from the axial data set or will be obtained directly. With the MRI FLAIR sequence in the axial plane the whole brain will be scanned either to depict or exclude a tumour invasion into the brain. After this,T2-weighted fast spin echo sequences or fatsuppressed inversion recovery sequences in high resolution technique in the axial plane will be obtained from the temporal bone and axial T1-weighted spinecho sequences before and after the intravenous application of contrast material will be obtained of this region. Finally T1-weighted spinecho sequences in high ...
The transport-relevant basic data recorded within the framework of a federation-wide transport data survey made in 1986 are the best-founded source at present for determining the transport volume of other radioactive materials in different economic areas of the Federal Republic of Germany. Due to the high recording rates, a sufficiently complete survey can be provided in particular with regard to the transport volume (e.g.transports/consignments/cargos, transport distance) - with the exception of transport by ship - for the ranges of application in reserach, medicine and technology. However, as regards the radiologically relevant basic data and transport modalities, the information supplied by the transporting agencies is incomplete. A table gives a comprehensive survey of type and scope of the transport volume of other radioactive materials in the Federal Republic of Germany (excluding the GDR) for transport by road, rail and air. The table also includes data on the dose rate of ...
The Deutsche Post AG is a transport company that with approximately 55,000 vehicles owns one of the biggest fleets in Europe. Being aware of its responsibility in the field of environmental policy it is looking for an alternative solution of an environmentally friendly vehicle drive system that also takes into account economic efficiency. Extensive investigations have led to a new energy storage based on the zinc-air energy system that has been developed and manufactured by the Israeli Company Electric Fuel Ltd. First tests showed an extraordinarily high capacity potential, drive values and ranges, which had been considered as impossible until that point of time. After these tests the Deutsche Post AG decided together with other well-known partners at home and abroad to carry out a territorial test with the zinc-air energy system in order to obtain insight into the day-to-day capability, economic efficiency, environmental friendliness under real driving conditions and into the required ...
The ECOTEC is a mass-efficient gasoline DOHC 4-valve per cylinder engine with balance shafts, chain driven camshafts and roller finger followers with hydraulic lash adjusters for valve actuation. It has lightweight aluminium components such as camcover, cylinder head, cylinder block, lower crankcase and structural oil pan. Other features include composite intake manifold and a coil-on-plug ignition cassette. The ECOTEC combustion system and engine architecture are optimized for low engine out and tail pipe emissions. It also includes several designed-in 'green' features for environmental benefits. The product design, development and validation process drew upon the best knowledge and practices available worldwide both inside and outside General Motor. The manufacturing systems were also designed by leveraging the best available knowledge around the world resulting in implementation of world class processes and error proofing to achieve the competitive edge in product ...
Normally, the alloy NiMo28 is used in the solution annealed and quenched condition in which it has a face centred cubic matrix structure. The matrix of the material is supersaturated with molybdenum and, at temperatures above 800 C, has a tendency to form intermetallic precipitates such as the Ni{sub 4}Mo-ordered phase leading to the embrittlement of the NiMo28-ordered phase leading to the embrittlement of the NiMo28 alloy during hot working. For this reason, the aim of these investigations was to optimise the alloy by reducing its tendency to embrittle. The TEM-analyses carried out served to investigate the precipitation of the material as a function of its iron content after ageing at 700 C. The change in hardness and in the lattice constants of the NiMo28-specimens with iron content were also determined. To improve the hot working properties of this material it is recommended that the iron content be kept to about 3.2 mass % in order to reduce the tendency of the alloy to ...
Several components of high-temperature reactor units have roller bearings in order to carry out their motions without much friction. The use of such bearings poses friction and wear problems which cannot be mastered by commercial roller bearing technology. Possible improvements of coating, cage design and bearing materials as well as of their parameters were registered and studied. The service life of dry lubricated bearings was considerably improved. With a radial or axial load on the bearing of {>=} 10% of the static load, {approx_equal} 20x10{sup 6} rolling motions/actuations can be performed. The connections between surface compression and wear were determined, and optimum conditions for the transfer of lubricants from the cage onto the bearing race were worked out. Coating of corrosion-resistant roller bearing steels with the HRB-M{sub 0}S{sub 2} running-in coating could be proved. New cage designs and materials were tested with positive results. Alternative coatings (thin ...
The first working meeting of the SAPIERR project about regional final storage of radioactive waste in the European Union was held in Piestany, Slovak Republic, on February 19 and 20, 2004. SAPIERR stands for Support Action: Pilot Initiative for European Regional Repositories. This is an independent study supported financially by the European Union within the 6th Research Framework Program. The background to the project is the debate about the feasibility of regional repositories for radioactive waste in the European Union, which has come up again especially with a view to the new accession countries and the draft of a waste management directive within the framework of the Nuclear Package. The results of the SAPIERR Project will be presented in Brussels at a concluding international seminar, most probably in October 2005. The seminar will be open not only to the participating countries but also to other interested European and non-European states. (orig.) [German] Am 19. und 20. Februar ...
Sprayforming offers the possibility to produce a variety of preforms in a single step directly from the melt. Numerous processing parameters ensure high flexibility but require detailed knowledge concerning the microstructure of sprayformed material depending on chemical composition and processing parameters. Within the current study fundamental investigations using unalloyed and low alloy steel grades (C15, C105, 100Cr6) for sprayforming of plates and billets have been performed concerning the influence of chromium and carbon content and selected processing parameters. Sprayformed preforms revealed austenite grain sizes up to 500 {mu}m depending on the development of porosity. Different types of porosity have been detected which can be associated with incomplete densification due to high cooling rates, solidification shrinkage and entrapped nitrogen. Atomisation gas pressure and carbon content are parameters of primary importance. (Abstract Copyright [2003], Wiley Periodicals, Inc.) ...
For purposes of assessing the dumpability of wastes, Article 1 - Ordinance on the Environmentally Responsible Landfilling of Household Wastes (AbfAblV) - of the Ordinance on the Environmentally Responsible Landfilling of Household Wastes and Biological Waste Treatment Plants defines classificaton criteria for biologically and mechanically treated wastes destined for landfilling. The practical experiences that have been gathered with these classification criteria and values were evaluated in a questionnaire-based survey. This was done in particular for the purpose of verifying and validating proposals on the methodology of respiration and fermentation tests. A general finding has been that the application and implementation of the regulations of the AbfAblV is fraught with difficulties. This is evident for one thing in the frequency of analyses and for another in the difficulty of complying with the limit values of the classification criteria. The authors are in support of demands that ...
In the year 1996 the spheres of competence of several DLR-Institutes working in the areas of fluid dynamics, reaction kinetics, combustion, numerical methods and laser measuring techniques have been brought together while contributing to the internal DLR project 'combustion chamber modelling (BKM)', in order to proceed with the computational simulation of combustion processes in combustion chambers of gas turbines. The main issue was the development of a research code for numerical simulation of fluid flow in real combustion chambers. Here the development of computational models of physical and chemical processes was emphasized, among other processes the formation of soot was treated. Moreover, a worldwide outstanding database of measured data for the purpose of code validation has been created within the framework of the BKM project using the laboratory facilities of the DLR, which are in Germany unique for the experimental investigation of the various processes in ...
One part of the RWE measure catalogue in order to guarantee an environmental friendly and competitive electric power generation based on brown coal is to carry out measures improving the efficiency at existing steam turbines in RWE brown coal power plants. Since 1993 a total of 21 steam turbines with a gross capacity of 7,100 MW or net capacity of 6540 MW - this corresponds to approximately 70 % of the installed RWE brown coal power plant capacity - have been improved with an investment of approximately DM 500 million. The net block efficiency has been increased by 1.3 % on average. The planned net capacity increase of approximately 250 MW is still going to be achieved taking into account the pending enhancements. Nuclear power plant turbines have been successfully improved in the same way. Apart from the described retrofit programme measures to improve efficiency are carried out at further steam turbines of brown coal power plants. In the frame of this talk the measures taken are ...
Previous AIX development environment experience with ASC White and Early Delivery systems UV and UM was leveraged to provide a smooth and robust transition to the Purple development environment. Still, there were three major changes that initially caused serious problems for Purple users. The first was making 64-bit builds of executables the default instead of 32-bit. The second was requiring all executables to use large page memory. The third was the phase-out of the popular, but now defunct, third-party C++ compiler KCC, which required the migration of many codes to IBM's xlC C++ compiler. On Purple, the default build environment changed from 32-bit builds to 64-bit builds in order to enable executables to use the 4GB per processor (32GB per node) memory available, and in order for the MPI library to do collective optimizations that required the larger 64-bit address space. The 64-bit build environment was made default by setting the IBM environment ...
A part of the waste materials arising in iron and steel manufacture is utilised physically, either internally for the recovery of iron or externally for the production of cement and nonferrous metals. Most of these materials can be used without prior processing. Iron and steel-relevant waste materials which at present are still landfilled or disposed of as hazardous wastes are not immediately suitable for physical recycling as secondary raw material. These waste materials have to be processed without exception before they can be used again in the existing steel and iron manufacturing plants. The results of the authors` own studies have clearly shown that the cupola furnace is suited for the use of a wide variety of waste materials. [Deutsch] Ein Teil der bei der Eisen- und Stahlerzeugung anfallenden Abfallstoffe werden entweder intern zur Rueckgewinnung des Eisens oder extern in der Zement- bzw. Nichteisenmetallgewinnung stofflich verwertet. Dabei handelt es sich ueberwiegend ...
The nuclear structure of A {proportional_to} 100 nuclei has been studied in the frame of this thesis with a recently developed {beta} - {gamma} - {gamma} triple coincidence fast timing technique and different models such as shell model, hydrodynamic model, Nilsson and particle-rotor models. This technique which allows the measurement of the level lifetimes in the ps range has been applied at JOSEF at the research reactor DIDO of KFA Juelich in studes of the short-lived neutron-rich nuclei in the A {approx_equal} 100 region. Lifetimes of level in {sup 96},{sup 98},{sup 100} ZR, {sup 99},{sup 101}-{sup 104} Nb, {sup 100}-{sup 105} Mo have been measured, which are in many cases completely new, and otherwise more precise than previously published data. From the lifetimes of the members of rotational bands, the size of the nuclear deformations has been deduced. (orig./HSI). [Deutsch] Im Rahmen dieser Doktorarbeit wurde die Kernstruktur der A {proportional_to} 100 Kerne untersucht. Dazu ...
The transversus perinei profundus muscle is a well known structure in found anatomical textbook. Fibres of this muscle are believed to form the so-called external urethral sphincter (musculus sphincter urethrae). Recently histomorphologic investigations have shown that there is no muscular connection between the musculus sphincter urethrae (external sphincter) and the muscle system of the pelvic floor. Furthermore, the external sphincter was found to be divided into parts: The transversely striated part (musculus sphincter urethrae transversostriatus) and the smooth part (musculus sphincter urethrae glaber). Similar to histomorphologic investigations, contrast-enhanced MR imaging has shown the musculus sphincter urethrae to be surrounded by fatty and connective tissue only. Neither in MRI nor in anatomical slices can any connection between the urethral sphincter and the muscle system of the pelvic floor be found. Thus, on the basis of the results presented in this work it is concluded ...
60 patients between 17 and 72 years of age were investigated. First, an enteroclysis was performed in typical manner. The applicated methylcellulosis was blended with positive oral MR contrast media (Magnevist oral, Schering). After enteroclysis, MRI of the abdomen was performed using T1- and T2-weighted breathhold sequences (Flash 2D pre- and postcontrast and TSE) in axial and coronal planes. The length of the affected bowel and the stenosis seen with enteroclysis correlated well with the visible thickening of the small bowel wall and the stenosis seen in MRI. Using MRI, additional findings could be obtained in 28 patients, such as fistulas, abscesses or a hydronephrosis, or a better assessment of the stenosis was possible with MRI, because of the avoidance of overshadowing of the affected bowel loop with MRI. A brilliant MR-tomographic imaging of the small bowel is possible under the condition, that the small bowel contrast is optimal. The main prerequisite is a large filling volume ...
Pyrolysis and combustion of CH are investigated. In order to reduce the work required for the present combination of parameters, the following substances were selected: Hexachloroethane, hexachlorocyclohexane, hexachlorobenzene and hexachlorophene. The model substances were pyrolyzed or combusted in varying conditions, and the combustion or pyrolysis products were analyzed. Only the main products were of interest; trace components are important only as far as they may throw light on the reaction mechanisms. The furnace design resulted in incomplete combustion and pyrolysis reactions, so that products of all stages of combusition or pyrolysis were available for analysis. Reaction processes can be derived from the products. As an alternative to thermal treatment of refuse, biological degradation of chlorinated hydrocarbons was gone into. The efficiency of decomposition by microorganisms was to be compared with the efficiency of thermal destruction of chlorohydrocarbons. The ...
Parallel imaging and echo sharing techniques have markedly reduced the acquisition times for MRI of large volumes. Dynamic 2 and 3-dimensional data sets of the chest with high temporal resolution (up to 10 images/s with single slice and 2 volume/s) allow an analysis of respiratory motion of the lungs and tumors. Time-resolved 2D series in preselected planes can be used to observe respiratory motion during free breathing or after respiratory commands, e.g. to exclude chest wall invasion by a tumor or for diagnosing impairment of respiratory mechanics. Time-resolved 3D-series (4D-MRI) allow monitoring of the spatial displacement of the lungs and tumors as a whole volume. Present limitations such as an overestimation of tumor size and an underestimation of displacement due to a limited temporal resolution are expected to be overcome with further technical developments. However, 4D-MRI already appears to be the appropriate tool to select patients for motion-adapted radiotherapy. In ...
In technical combustors, flow and combustion processes inside the combustion chamber determine the design and also the safety of the plant. A modelling technique was developed at TU Dresden which comprises both numerical simulations and experimental data and thus achieves a high degree of transparency in its visualisation of the processes inside the combustion chambers under investigation. With the experience gained, numerical models of commercial simulation software (FLUENT, CFX) can be validated by measured values, and potential applications of the programs can be investigated. The first stage of experimental modelling consisted in isothermal (cold) modelling in consideration of flow-relevant similarity characteristics. In the reactive, non-isothermal models, the fuel/air ratio and temperature conditions inside the original combustion chamber were modelled as well. In order to obtain detailed data on the combustion conditions at the burner, measurements were made on a separate ...
To determined precisely a possible connection between the amount of copper in tap-water and the risk of early childhood liver disease, it was attempted through an epidemiological survey, to determine the extent of excessive concentrations of copper in the tap-water of households with copper pipes. Water samples from 956 households were tested for copper, and the state of health of the infants in these households was documented. Infants who had been fed using water with a copper concentration of 0.8 mg/l or more received a paediatric examination with a blood serum analysis to rule out any liver damage. A copper level greater than 0.8 mg/l was found in only 2% of the households examined. Eight infants were examined by a paediatrician and their serum was analysed. These infants had either been breast-fed to the 12th week or had received more than 200 ml of tap water per day during first 12 months. None of the infants examined showed any signs of liver malfunction. From the results of the ...
On the basis of cylindrical roller thrust bearings it was systematically examined to what extent PVD-coatings are able to take over the function of EP/AW-additives. The bearings were tested under heavy-duty conditions in order to distinguish very fast the efficiency of different coating-substrate-systems. Several coatings were tested for their ability to protect an un-coated counterpart. So just the washers of the roller bearings were coated, the rollers stayed un-coated. Four Me-C:H-coatings showed the best performance and fulfilled the required criterion for roller bearings in the boundary friction: low loss of mass and hardly surface deviation. Material carryover from the carbonaceous coating to the 100Cr6 steel surface was developed by the Me-C:H-coatings during the tests. This mechanism was able to protect the un-coated rollers. Closer investigations were done with an ESMA analysis (electron beam micro range analysis) on ZrC{sub g}-coatings. It could be seen, that a reaction layer ...
Purpose: Budd-Chiari syndrome is a fairly uncommon disease in Europe. This often leads to its late diagnosis. The syndrome is characterised by portal hypertension and splanchnic congestion due to obstruction of hepatic venous outflow. This paper describes the treatment of three patients with Budd-Chiari syndrome by interventional therapeutic techniques and discusses alternative treatment modalities. Patients and Methods: The first patient presented with veno-occlusive disease and was treated by the placement of a transjugular intrahepatic portosystemic stentshunt. The second patient showed an occlusion of the major hepatic veins. After percutaneous recanalisation, a stent was placed in the right hepatic vein which remained patent. The third patient had a membranous obstruction of the right hepatic vein which was treated by percutaneous balloon dilatation. Results: In all patients the clinical symptoms resolved completely after treatment and no complications were encountered. ...
For a wider application of GaAs single crystals for semiconductor devices a cheaper process to grow crystals with high purity and low dislocation density is required. According to todays knowledge the Czochralski method with a hot wall vessel should be the choice. The temperature of the vessel has to be 700deg C to avoid condensation of arsenic which vapourizes from the 1240deg C hot melt. Arsenic vapour is very agressive against all metals. Therefore the corrosion resistance of metals and alloys with a high melting point and also ceramics has been tested. All the alloys under investigation are corroded severely so that they have to be excluded as a material for the vessel. The metals tantalum, molybdenum and tungsten are more resistent, titanium forms initially a thick protection layer and further corrosion is greatly reduced. The ceramics investigated (TiB{sub 2}; ALN; Makor; BN) are not attacked by arsenic though they may store some arsenic. (orig./MM). [Deutsch] Fuer breitere ...
Maintenance of power stations so far operated on the concept of using or extending the expected service life of a machine or plant as far as possible in order to avoid early and costly replacement. This was done by means of time-oriented maintenance, inspection and repair, otherwise called preventive maintenance. A European study on maintenance methods totals the cost of these measures at between 140 to 200 billion DM. One way of reducing these costs is 'predictive maintenance'. Estimated savings are about 8 percent or between 12 and 16 billion DM per year. Predictive maintenance identifies irregulaties of machine parts at an early point in time by means of condition monitoring and can help to cut costs: unplanned repairs can be avoided; repairs can be fitted into production schedules; production will not be disturbed to to unforeseen repairs, optimised spare part warehousing helps to cut costs. Predictive maintenance aims at keeping availability high, give maximum ...
The influence of a decarburisation process during austenitising of the through-hardenable rolling bearing steel 100Cr6 (SAE 52100) on the rim zone properties of the martensitic through-hardened material was investigated by means of material analysis and diffusion calculations. For this purpose, two specimens were prepared under defined heat treatment conditions, and the near-surface carbon distribution was determined micro-chemically by using secondary ion mass spectrometry (SIMS). In part 1 of the present work, these concentration profiles are compared with the depth variation of the micro-hardness and with the distance curves of the residual stresses and the line broadening ({l_brace}211{r_brace} {alpha}'-Fe diffraction line) both measured by X-ray diffraction (XRD). In addition, microstructure investigations were performed. In part 2, a refined kinetics model of a diffusion-controlled reaction based on the finite element method (FEM) will be applied to the decarburisation ...
The paper presents fundamental studies on natural biosorption to algae of heavy metals. The investigations were carried out by TU Berlin University in a special research project (Sfb 193, 'Biologische Behandlung industrieller und gewerblicher Abwaesser'). The chlorophyceae C. vulgaris was used as reference alga, and 38 further algae were analzyed with regard to their sorption characteristics for lead, cadmium, nickel and zinc. The most effective algae were the chlorophyceae C. salina, the cyanophyceae S. hofmani and L. taylorii. The biosorption characteristics of C. salina and L. taylorii were investigated in detail. L. taylorii was found to be exploitable successfully in a technical process, so the investigations were extended to include copper. Knowledge about the chemical processes of biosorption is important for any attempt to modify the biosorption characteristics. Experiments on the incorporation of additional functional groups in the cell wall polysaccharides ...
This report completes the documentation for the research project 'High Pressure Compressor - Preliminary Design as Basis for the Development of an Efficient and Environmentally Friendly Core Engine' which was funded by the Ministry of Economics of State Brandenburg. The objective of the project is to deliver a preliminary compressor aerodynamic design as well as design studies for an efficient, weight and cost improved compressor. The increase of stage pressure ratio and improved efficiency, whilst stage and blade count is reduced, has been achieved by advanced 3D methods. Compressor stability also at off-design conditions will be retained. The mechanical design focusses on a cost and weight optimised rotor not only for a conventional bladed discs but also for Blish stages. Various options for split casings have been developed and assessed. Alternative vortex reducers based on different design options have been carried out. The results from this project will be ...
Storing electrical energy in batteries is not a viable option for sustaining a country's energy economy. The mass and volume, as well as the costs, of electrochemical components required for this would be beyond all reason. Nevertheless, in certain applications the storage of electrical energy does have significant advantages over other technologies. For example, electrically powered road vehicles emit no exhaust fumes and very little noise at their place of operation. In this way they contribute substantially to air and noise pollution control in urban areas. Photovoltaic applications permit environmentally friendly electricity applications in places remote from the public grid where conventional solutions are prohibitively expensive. More than in the past, battery systems today have to meet a wide range of technical, economic and ecological requirements in order to be marketable. This is why the ''Zoxy'' zinc-air battery system was ...
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This thesis deals with the analysis of dominant loss mechanisms in direct methanol fuel cells (DMFC) and hydrogen fed polymer electrolyte membrane fuel cells (PEFC) by means of experimental characterization and modeling work. Due to different fuels used in these two fuel cell types, the dominant loss mechanisms are different in their nature. All in-situ characterization techniques that are used in this work are based on a novel test fuel cell with embedded reference electrodes. The first part of this work presents a new concept for realizing a reference electrode configuration in a polymer electrolyte membrane fuel cell by means of laser ablation. The laser beam is used to evaporate a small gap into the electrode surface of a catalyst coated membrane (CCM) to isolate the reference electrode from the working/counter electrode (WE/CE). This method enables the simultaneous ablation of the electrodes on both sides of the CCM because the membrane is transparent for the laser beam. ...
The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions caused by recurrent cholesteatoma, bony defects ...
To evaluate the current situation and implementation of embolization of uterine leiomyomas into the treatment concept in women with symptomatic uterine leiomyomas in Germany. A questionnaire addressing the clinical background of uterine myomas, recommended treatment concepts, preclinical evaluation, technical approach and complications was sent to 164 departments of gynecology and radiology in Germany. 33 radiological departments and 19 gynecological departments submitted a completed questionnaire. Only 7 departments of radiology reported to have own experience with embolization of uterine leiomyomas, while only 2 departments of gynecology considered embolization as an alternative treatment option in patients with symptomatic leiomyomas. 18/33 radiological departments offer this treatment option but get no patient referrals. Agreement was found concerning the indications for treatment, preclinical evaluation by ultrasound and MRI, preferable location of treatable fibroids, technical ...
The staging of patients with multiple myeloma demands sensitive imaging methods for the assessment of the skeletal system. MRI allows for direct visualization of the bone marrow which exhibits five different infiltration patterns in multiple myeloma: 1. normal appearance of the bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. ''salt and pepper'' pattern with inhomogeneous bone marrow signals due to multiple fat islands. The combination of T1w-SE and STIR sequences is best suited for detecting all infiltration patterns and for the differential diagnoses e. g. hemangiomas. With parallel imaging in MRI, acquisition times can be markedly reduced and whole-body screening of the bone marrow can be achieved within 30 min. MRI is superior to radiography for the detection of focal as well as diffuse infiltration. Multidetector computed tomography and especially 16- and 64-detector row ...
The experimental effect investigation programme on Zircaloy-4/air oxidation was pursued and expanded to isothermal specimen exposure and the comparison of the oxidation between the atmospheres Ar/O{sub 2} and air. In close connection with the EC project OPSA, which is meanwhile terminated, the investigation concerned specimen exposure in a thermobalance to flowing atmospheres, namely dry Ar/O{sub 2} of composition 80/20 or synthetic air, respectively. As test parameters the linear heat-up rate was varied in the range 5 to 40 K/min and the ramp or holding temperature between 800 and 1500 C. Mass increase and reaction rate were continuously recorded or evaluated in temperature/time dependence. The oxide scale growth was found to be accompanied by colour changes, crack formation and spalling of layers, as well as by dimensional substrate growth, which are the reasons for the observed kinetic results. The microstructural investigation confirms nitrogen to be essentially responsible for the ...
The aim of this work was the examination of the coarse grain recrystallisation of the {gamma}-free ODS nickel-based alloy PM 1000 depending on the various parameters due to the processing during heat treatment. After isotropic hot compacting (HIP) of the mechanically alloyed powder, one observes a homogeneous sub-microscopic fine grain structure which can coarsen during high temperature heat treatment, due to sufficiently high driving force from the grain boundary energy via abnormal grain growth to 600 times its size. The setting of the elongated high temperature resistant recrystallisation structure is, however, not connected with this. The dependence of the sucess of re-crystallisation on the re-forming parameters (re-forming temperature and degree of re-forming) was shown by a socalled re-forming card. In order to achieve re-crystallisation to a coarse and aligned grain structure, apart from a certain absolute minimum degree of re-forming, the re-forming must occur within a defined ...
The fundamental recommendations of the ICRP issued in its publication of 1990 stipulate the general principle of performance of dose measurements at regular intervals in the field of diagnostic radiology, for the purpose of equipment performance checking and optimization of radiological protection. In response to this requirement, the Federal Ministry, in cooperation with experts and the competent supervising authorities, has issued an order to install dose-area-product meters in angiographic examination systems, imaging systems and fluoroscopic screen devices primarily used for examining infants and children up to the age of 12. This is done in response to reported cases of adverse effects of radiation exposure and the high priority given to radiological protection in the examination of infants and children. In 1992, an expert group was convened to discuss and elaborate instructions for including dose-area product measurement in the dosimetry activities in medical diagnostic ...
Patients with haemarthros of the knee were examined by MRI and arthroscopy to identify the bleeding source and to determine surgical or conservative therapy. A prospective study was performed on 120 patients who underwent MRI and arthroscopy, point lesions and bleeding sources were documented separately on a standardised form. Arthroscopy demonstrated a ruptured anterior cruciate ligament in 86%, meniscal tears in 55%, disruption of collateral ligaments in 17%, osteochondral lesions in 5% and tears of capsule or plicae in 13%. Disruption of cruciate ligaments caused haemorrhage in all but three cases. In contrast, only meniscal tears located very adjacent to the meniscal basement had bled. Those types of osteochondral lesions caused haemorrhage characterised on MRI by destruction of the subchondral plate and overlying cartilage. Severe lesions of the knee were diagnosed by MRI in 71% to 100%, slight lesions in 13% to 40% of the cases. Single, combined and bland lesions were accurately ...
The R and D activities of the institute focused on two major projects, ``Molecular and cellular environmental toxicology``, and ``Biophysics of multi-cellular systems``. For assessment of health risks emanating from the uptake of heavy metal compounds, work performed under the first mentioned project studies the formation of allergy-inducing metabolic products from membrane lipids, and the effects of related cellular signaling processes. These studies are accompanied by an approach to quantify and classify the toxicity of environmental organometallic compounds. Another major task is research into the pathogenesis of lung disease induced by dusts, gases, and gas-dust mixtures and the liberation of inflammatory agents by immunological cell reactions (alveolar macrophages). Atomic force microscopy is the tool used to visualize the related dynamic changes in bronchial cells. Studies for detection of the localisation and structure of the Fe-Mo co-factor in nitrogenase by means of the method ...
Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager (`Vision`, Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of 6 images/s and an in-plane resolution of ...
A cooperative effort of the Center for Solar Energy and Hydrogen Research (ZSW) and Phototronics Solartechnik GmbH (PST) aimed at the transfer of highly efficient solar cells developed on a laboratory scale, to large-area thin-film solar modules suitable for production. This work was based on research and development at the Institute for Physical Electronics (IPE) of Stuttgart University and ZSW on one hand, and on the know-how of PST in regard to large-area module fabrication on the other hand. The various thin-film layers of the cells and modules comprize molybdenum as rear contact, copper-indium(gallium)-diselenide (CIGS) as absorber material, the combination of cadmium sulphide (CdS) and ZnO as window layer. To produce these layers on large areas (30x30 cm{sup 2}), equipment was constructed and procedures were developed. Monolithic series connection of cells, used in other thin-film technologies, was studied and optimized by suitable patterning procedures, such as laser-scribing, ...
This report describes work carried out in the context of TurboTech Interim for the development of a system for monitoring stationary gas turbines for approaching the stability limit of the compressor. The requirements for the system components were defined and the suitability of different types and positions of pressure sensors were examined and evaluated. It was found very early in the work that, due to the complexity of the object being monitored, one would not succeed in finding a simple criterion for monitoring the pump limit. Rather, apart from the selection of suitable sensors and optimum positions, one must analyse the present signals in different ways and create a decision matrix from this. Existing work on this subject is mostly concerned with the phenomena in the context of experiments on experimental compressors or is not suitable for the requirements of stationary industrial gas turbines. The project is being carried out in the context of TurboTech II with the main aims of: ...
Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. All data were blinded and separately read by ...
Main topic of the project was the manufacturing of highly efficient GaAs-solar cells and the fabrication of concentrator cells. During this process significant progress was made with the material preparation, the solar cell technology and the material and process characterisation. This succeeded in the following efficiencies: - GaAs solar cell made by MOVPE technology: 22.9% on 4 cm{sup 2} (AM1.5g) - GaAs solar cell made by LPE-ER process: 22.8% on 4 cm{sup 2} (AM1.5g) - GaAs concentrator solar cell made by LPE-ER process: 24.9% at C=100xAM1.5d - GaAs concentrator module with fresnel lenses: Module efficiency 20.1% (under irradiation of 793 W/m{sup 2}). Another main focus was the epitaxy of GaAs on Si substrate. Two different approaches were investigated. Together with the cooperation partner ASE, Heilbronn a selective growth technology was developed that led to a decreased crack formation. By a simultanous optimization of the other epitaxy and process parameters, the efficiency was ...
We report for the first time about a micromachined mass flow sensor directly integrated between the double guidance and the needle seat into the body of a Common Rail (CR) injection nozzle. The thermal measurement principle was chosen because gaseous as well as liquid mass flows can be determined fast and precisely. Additionally, with glass-ceramic materials fabricated in a low cost batch process, a high temperature and especially pressure stable substrate can be used. The flow sensitive thin film is realized by an e-beam evaporated 110 nm thick molybdenum (Mo) layer. The latter is electrically characterized by the resistivity of {rho} = 8.2 x 10{sup -7} {omega} m ({+-}2%) at room temperature as well as by the first {alpha}=4.5 x 10{sup -4} K{sup -1} ({+-}5%) and second {beta}=3.0 x 10{sup -6} K{sup -2} ({+-}12%) temperature coefficients of resistance up to 300 C. The static temperature field at and around the thin film sensor on the glass-ceramic substrate is investigated with an IR ...
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Low energy buildings promise significant energy savings and help climate preservation by cutting down on annual heating requirements to values below 70 kWh per m{sup 2} dwelling space. It is expected that low energy constructions will become the common standard by the year 2000 as a result of the forthcoming energy saving ordinance. For making the introduction and implementation of this standard successful, practical experience will be essential. For this reason, the state government of Hesse has supported respective pilot projects 1987. In 1989 the funding programme `30 low energy buildings in Hesse` has been established. Consecutively - between 1989 and 1993 - 29 buildings were erected. At first, the thermal quality of the crafted building construction including the ventilation systems was checked. Consecutively, energy consumption, indoor and outdoor temperatures were measured over a time span of several years. The experience of the inhabitants was surveyed. The `Institut Wohnen und ...