In 9 over 12 patients who underwent cardiac transplantation computed tomography was performed. In 5 of them CT was obtained also before the surgical treatment. In all patients angio-CT technique was performed, while the ECG-gated technique was employed only before surgery. CT shows changes in morphology of both atria but over all of the right one, and rotation of the heart on the longitudinal axis. The conditions of the pericardium are particulary well demonstrated: in 5 cases pericardial effusion was observed, 3 times localized and 2 times diffuse. Only in 1 patient a small thrombus in the right atrium was demonstrated. CT allows the possibility to obtain simultaneously information on mediastinum, lung and pleura. Pleural effusion, pulmonary infections and mediastinal complications are easily demonstrated.
Purpose: To quantify left ventricular function derived from retrospectively ECG-gated multislice spiral CT (MSCT) data sets in comparison to MRI. Materials and Methods: In 16 patients (14 males, 2 females, mean age 56.8 #+-# 11.5 years), retrospectively ECG-gated MSCT angiography of the coronary arteries and breath-hold steady state free precession cine MRI were performed. From MSCT data-sets, 20 axial image series were reconstructed every 5% of the RR interval. Multiplanar images were reformatted in the short axis orientation from axial images. End-systolic and end-diastolic images were selected. From these images end-systolic volume (ESV), end-diastolic volume (EDV) and stroke volume (SV) as well as the ejection fraction (EF) and myocardial mass (MM) were determined using the Simpson's method and compared with MRI. Furthermore, image quality was assessed for both imaging modalities using a four point grading scale. Results: All parameters ...
The standard protocol in multislice spiral CT (MSCT) angiography for coronary arteries with fixed tube current-time settings leads to an overexposure and thus to an unnecessary high radiation dose in patients with lower weight when compared to heavier patients. The purpose of this study was to estimate the effect of reducing the radiation dose by adapting the tube current-time settings individually. Fifty patients underwent retrospectively ECG-gated MSCT of the heart. In 25 patients (group A{sub 1}) a standard protocol with constant tube current-time settings was used (4 x 1-mm collimation, 120 kV, 400 mAs{sub eff}). Subsequently, artificial image noise was added to the data of these patients simulating a directive for weight-adapted tube current-time settings (group A{sub 2}). In the other 25 patients (group B) an alternative protocol with individually weight-adapted tube current-time settings was applied. The data of all groups were evaluated by a regression ...
The standard protocol in multislice spiral CT (MSCT) angiography for coronary arteries with fixed tube current-time settings leads to an overexposure and thus to an unnecessary high radiation dose in patients with lower weight when compared to heavier patients. The purpose of this study was to estimate the effect of reducing the radiation dose by adapting the tube current-time settings individually. Fifty patients underwent retrospectively ECG-gated MSCT of the heart. In 25 patients (group A_1) a standard protocol with constant tube current-time settings was used (4 x 1-mm collimation, 120 kV, 400 mAs_e_f_f). Subsequently, artificial image noise was added to the data of these patients simulating a directive for weight-adapted tube current-time settings (group A_2). In the other 25 patients (group B) an alternative protocol with individually weight-adapted tube current-time settings was applied. The data of all groups were evaluated by a regression analysis. The ...
This perspective view of Venus, generated by computer from NASA's Magellan data and color-coded with emissivity, shows part of the lowlands to the north 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 ...
The CO{sub 2} emissions can be reduced by using economic instruments, like carbon tax. This project included two specific questions related to CO{sub 2} taxation. First one was the economic effects of increasing CO{sub 2} tax and decreasing other taxes. Second was the economic adjustment costs of reducing net emissions instead of gross emissions. A computable general equilibrium (CGE) model was used in this analysis. The study was taken place in Helsinki School of Economics
The report describes a computer model developed by TVA to simulate the performance and determine the economics of coal cleaning, or coal cleaning combined with flue gas desulfurization (FGD), for power plant emission control processes over a wide range of user-specified condition...
Fugitive dust emissions from stockpiles in the open storage yards of industrial zones and the subsequent atmospheric dust dispersion have brought about many ecological and economical problems. This paper introduces a new approach to reduce pollutant emissions by simply changing pile configuration and without affecting the operational activity on these parks. Flow around piles of different geometries and for various wind conditions was studied using previously validated Computational Fluid Dynamic (CFD) simulations. Different pile height scenarios were investigated corresponding to a constant material volume and a fixed angle of repose under various wind magnitudes. The results obtained were integrated in order to evaluate the rate of dust emissions for the various configurations considered. It was found that, for the range of wind conditions and pile dimensions tested, an optimal geometry exists which ...
BackgroundIn primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emissioncomputed tomography (Tc99m-MIBI-SPECT) for localizing pathological...Full Text Available
To determine the diagnostic accuracy of iofetamine hydrochloride I 123 (IMP) with single photon emissioncomputed tomography in Alzheimer's disease, we studied 58 patients with AD and 15 age-matched healthy control subjects. We used a qualitative method to assess regional IMP uptake in the entire brain and to rate image data sets as normal or abnormal without knowledge of subjects'clinical classification. The sensitivity and specificity of IMP with single photon emissioncomputed tomography in AD were 88% and 87%, respectively. In 15 patients with mild cognitive deficits (Blessed Dementia Scale score, less than or equal to 10), sensitivity was 80%. With the use of a semiquantitative measure of regional cortical IMP uptake, the parietal lobes were the most functionally impaired in AD and the most strongly associated with the patients' Blessed Dementia Scale scores. These ...
This demonstration project uses modern simulation techniques to illustrate the important technologies and design variables that an auto-designer would consider in production a high efficiency, low emissions vehicle. Simulation and modeling techniques use the idea of capturing the relationships between real components of the systems with mathematical equations. These equations are then solved on a computer to simulate the behavior or performance of the system under various conditions. In the current demonstration project, we focus on many variations of a hydrogen-powered vehicle.
It is a traditional method to diagnose electron-cyclotron-resonance (ECR) plasma source, using a single probe to measure the current-voltage curve of the plasma, based on which and theoretic formula the plasma density can be computed. The article adopts a Langmuir probe having a role of emission electrons to measure two different current-voltage curves with and without emission. It is ease to get the plasma potential via the inflexion of the two curves and compute directly various physical quantities by the assistant computer, such as electron temperature, electron/ion density, plasma potential etc. The deviation is about percent 1.8 between the measurement results by traditional and the new method, but the latter has higher efficiency. (authors)
A link is made in this paper between proposed low energy scenarios for different Western European countries and the amount of pollutants that may result from these scenarios. Air pollutant emissions are calculated for the ten countries for which low energy scenarios are available. These scenarios emphasize stringent energy efficiency, maximizing the use of renewable (other than nuclear) energy, and minimizing the use of fossil fuels. Under these low energy scenarios, the average per capita energy use (year 2030) in the ten countries is estimated as 97 GJ/person, which is a decrease of 38% relative to 1980. Using the energy consumption figures from the low energy scenarios, together with sector- and fuel-specific emission factors from Europe, the resulting emissions of SO_2 , NO_x , and CO_2 were computed. These estimates do not take into account any add-on pollution controls over and above what was in ...
The linear integral equation based computer code (RON: Roger Oleg Nikolai), which was recently developed at Argonne National Laboratory, was used to calculate the self-amplified spontaneous emission (SASE) performance of the free-electron laser (FEL) being built at Argonne. Signal growth calculations under different conditions are used for estimating tolerances of actual design parameters. The radiation characteristics are discussed, and calculations using an ideal undulator magnetic field and a real measured magnetic field will be compared and discussed.
A multi-zone computational model in conjunction with some engine tests are used to examine the combustion process of gas fueled diesel engines common known as dual fuel engine to provide information about details of the production of exhaust emissions, especially at light load when very lean mixtures are employed. Detailed chemical reaction kinetic simulation is employed for each of these individual combustion zones so as to establish the associated temporal variations in the concentrations of reacting species right to the exhaust stage. The influence of changes in major operating and design parameters such as the concentration of the gaseous fuel in the cylinder charge, intake temperature and the size of the diesel pilot fuel employed on the production of the exhaust emissions are examined. It is demonstrated in general that any measure that tends to increase the size of the combustion regions within the overly lean ...
A multi-zone computational model in conjunction with some engine tests are used to examine the combustion process of gas fueled diesel engines commonly known as dual fuel engine to provide information about details of the production of exhaust emissions, especially at light load when very lean mixtures are employed. Detailed chemical reaction kinetic simulation is employed for each of these individual combustion zones so as to establish the associated temporal variations in the concentrations of reacting species right to the exhaust stage. The influence of changes in major operating and design parameters such as the concentration of the gaseous fuel in the cylinder charge, intake temperature and the size of the diesel pilot fuel employed on the production of the exhaust emissions are examined. It is demonstrated in general that any measure that tends to increase the size of the combustion regions within the overly lean ...
A phenomenological model based on the multizone method is described. The model requires a relatively low amount of central processing unit (CPU) time and memory for each run and, consequently, is useful for parameter studies. The flame morphology predicted by the model is compared to that recently uncovered in experimental studies. As a demonstration of its utility, the model is used to study the effect of the oxygen content in intake air on the emission of particulate matter (PM) and NO{sub x} from a direct injection diesel engine. A parametric study reveals that while oxygen-enriched intake air is useful for reducing PM, the reduction comes with a large increase in NO{sub x} emission. The PM-NO{sub x} trade-off curve for the oxygenated intake air is worse than that for the baseline air case. (Author)
Performance and emissions data were gathered on a normally aspirated single cylinder DI engine with various combinations of ceramic coatings installed. Thin ceramic thermal barrier coatings were applied to the piston crown and bowl, the head and valves, and the cylinder liner. The coated piston and head were run singly and in combination with the cylinder liner to investigate the effects of these different coated surfaces on emissions and performance. Coating the piston crown alone results in generally lower cylinder pressure, lower brake specific fuel consumption and lower NO(x) emission compared to the baseline engine. Soot emission is typically increased below 2000 RPM and decreased above 2000 RPM. Coating the head alone reduces cylinder pressure, but generally increases specific fuel consumption and NO(x) and soot emission. The KIVA-II code was used to model the Hydra engine ...
The work described in the following is a portion of the MEET project (Methodologies for Estimation Air Pollutant Emissions from Transport). The overall goal of the MEET project is to consolidate and present methodologies which can be used to estimate air pollutant emissions from various types of traffic sources. One of the goals of MEET is to provide methodologies to be used in the COMMUTE project also funded by DG VII. COMMUTE is developing computer software which can be used to provide emissions inventories on the European scale. Although COMMUTE is viewed as a prime user of the information generated in MEET, the MEET results are intended to be used in a broader area, and on both smaller and larger spatial scales. The methodologies and data presented will be useful for planners on a more local scale than a national or continental basis. While most attention in previous years has been concentrated on ...
RADSOLVER is a computer program which calculates the radiation energy transport in cavity type receivers having an arbitrary number of apertures through which collimated beams of solar radiation enter. In contrast to the common assumption of gray (or semi-gray) surfaces used in the modeling of radiation transport, RADSOLVER accounts for the wavelength-dependence of emission, absorption and reflection with a band model of the radiative properties. It is intended that this report serve both as an instruction manual for the use of the RADSOLVER code and a vehicle for presenting the underlying theory. Illustrative examples along with input and output are presented.
Absorption with aqueous amine solvents is at present the most viable technology for CO{sub 2} capture. While this is a proven technology, efforts are ongoing to improve it in order to make it a more attractive technology for large scale use to reduce CO{sub 2} emissions. Finding solvents with better properties is one approach to improving the technology. In this thesis methods in computational chemistry are used to improve the understanding of the chemistry of CO{sub 2} absorption in amine-water systems. The work is also intended to provide models that can be used to predict the performance of new solvents. Such predictive models are intended to facilitate the screening for new solvents
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 ...
A review is made of the various brain imaging agents utilised in the post few years with their own characters and respective advantages: cerebral blood volume tracers, non diffusible tracers, diffusible tracers among which gases and lipophilic agents. Our results with IAMP and SPECT are presented in two different clinical application fields: normal pressure hydrocephalus and cerebral ischemia.
A review is made of the various brain imaging agents utilised in the post few years with their own characters and respective advantages: cerebral blood volume tracers, non diffusible tracers, diffusible tracers among which gases and lipophilic agents. Our results with IAMP and SPECT are presented in two different clinical application fields: normal pressure hydrocephalus and cerebral ischemia.
Scintigraphic imaging of dementia relies today essentially on the study of brain Single Photo EmissionComputed Tomography (SPECT) perfusion, after intravenous injection of 99mTc radio-pharmaceutic. This paper is based on the guidelines published in October 2001 by the European Association of Nuclear Medicine (http://eanm.org/). (author)
In developing new receptor-site specific brain imaging agents labeled with I-123 for single photon emissioncomputed tomography (SPECT), an analog of raclopride, 3-["1"2"5I]-iodo-N-[(1-ethyl-2-pyrrolidinyl)-methyl]-2-hydroxy-6-me-thoxy benzamide (IBZM), was prepared using a method similar to that reported for raclopride and its derivatives. (author).
An exhaustive compendium of normal and abnormal imaging is presented. The following systems and procedures are illustrated by over 2800 captioned illustrations: liver, spleen, and hepatobiliary imaging; perfusion and ventilation lung imaging; thyroid imaging; salivary gland imaging; bone imaging; brain imaging; radionuclide cisternography; blood flow studies; gallium imaging; nuclear cardiology; and renal imaging. Not included in the atlas are adrenal imaging procedures and emissioncomputed tomography. (ERB)
The Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model simulates long-term transport and deposition of oxides of and nitrogen. t is a potential screening tool for assessing long-term effects on regional visibility from sulfur emission sources. owever, a rigorou...
An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.
Neutrino emission drives neutron star cooling for the first several hundreds of years after its birth. Given the low energy ($\\sim$ keV) nature of this process, one expects very few nonstandard particle physics contributions which could affect this rate. Requiring that any new physics contributions involve light degrees of freedom, one of the likely candidates which can affect the cooling process would be a nonzero magnetic moment for the neutrino. To illustrate, we compute the emission rate for neutrino pair bremsstrahlung in neutron-neutron scattering through photon-neutrino magnetic moment coupling. We also present analogous differential rates for neutrino scattering off nucleons and electrons that determine neutrino opacities in supernovae. Employing current upper bounds from collider experiments on the tau magnetic moment, we find that the neutrino emission rate can exceed the rate through neutral ...
Oil and gas resources in the offshore areas of the US constitute a significant portion of US recoverable hydrocarbon resources. The exploration, development and production of these offshore resources in California, however, could have significant air quality implications for coastal air basins. This study was developed to address a problem that frequently arises with offshore air quality assessments. Typically, such assessments are performed for a specific activity scenario (e.g., a Federal OCS Lease Sale involving a projected number of drilling rigs, platforms, pipelines, etc.) and assume a projected (but uncertain) level of recoverable oil and gas resources. This study enables interested parties to estimate air emissions and impacts for a wide range of OCS-related development scenarios. The modular emission calculation procedure and the generic impact assessment provide for maximum flexibility in reassessing the emissions ...
Until now policy makers and researchers considered the problem of uncertainty and verification to be of minor importance for the Kyoto process. However, the first studies that recently appeared on uncertainty estimation of carbon accounting reveal that uncertainties of the reported emissions on the country level are large. In an environment of such large uncertainties, verification of emission reductions must be viewed as a crucial mechanism to secure the very functioning of the Protocol. The paper provides a set of tools to strategically deal with the problem of uncertainty and verification under the Kyoto Protocol. This is done by: providing an overview of the instruments to deal with verification (no-, trend-, level- and top-down/bottom-up verification under PCA and FCA); compute costs scenarios for those instruments under various flexibility scenarios; and providing a short discussion on practical steps and crucial ...
Existing oil reservoirs might be more fully exploited if the properties of the flow of oil and water in porous media were better known. In laboratory experiments it is important to collect as much information as possible to make a descriptive model of the system, including position imaging and chemical binding information. This thesis develops nuclear methods for obtaining position image and chemical binding information from flow experiments of porous media. A combined positron emission tomography and single photon emissioncomputed tomography system to obtain position images, and a time-differential perturbed angular correlation system to obtain chemical binding information, have been built and thoroughly tested. 68 refs., 123 figs., 14 tabs.
From self-consistent band structure calculations using the 'augmented plane wave'(APW) method, the density of states can be decomposed into local partial (according to azimuthal quantum number l) components, the l-character densities. Within the APW formalism the intensity of X-ray emission spectra is determined by radial transition probabilities and l-character densities of such valence states, which reside inside the same atomic sphere as the core vacancy and whose quantum number l differs by +-1 from the one corresponding to the core state. By taking into account lifetime broadening of the core and valence states and also the instrumental broadening the computed spectra (non-metal K-, vanadium K- and Lsub(III)-spectra) agree well with experiment. (orig.).
Atomic ensembles, comprising clouds of atoms addressed by laser fields, provide an attractive system for both the storage of quantum information and the coherent conversion of quantum information between atomic and optical degrees of freedom. We describe a scheme for full-scale quantum computing with atomic ensembles, in which qubits are encoded in symmetric collective excitations of many atoms. We consider the most important sources of error-imperfect exciton-photon coupling and photon losses-and demonstrate that the scheme is extremely robust against these processes: the required photon emission and collection efficiency threshold is #approx#>86%. Our scheme uses similar methods to those already demonstrated experimentally in the context of quantum repeater schemes and yet has information processing capabilities far beyond those proposals.
The ventilation requirements for decontamination are normally determined with a static calculation method. In some cases, the pollutant emission is intermittent, for example in the car park of an office building, where all the cars enter and leave the place nearly at the same time. Generally, in such a case, the volume of the garage is large, consequently the time constant of the system has a high value. So a static approach would no longer stay accurate and a dynamic evaluation is needed. With the help of some assumptions, calculations remain rather simple and results can be plotted on nomographs or computed on a programmable handheld calculator. The amount of energy saved may appear very large in some cases. A sizing optimization will be required but also remains easy to compute. The paper presents the method of calculation for a single ventilation level and the optimization of a two-level ventilation.
The piston bowl design is one of the most important factors that affect the air-fuel mixing and the subsequent combustion and pollutant formation processes in a direct-injection diesel engine. The bowl geometry and dimensions, such as the pip region, bowl lip area, and toroidal radius, are all known to have an effect on the in-cylinder mixing and combustion process. In order to understand better the effect of re-entrant geometry, three piston bowls with different toroidal radii and lip shapes were investigated using computational fluid dynamics engine modelling. KIVA3V with improved submodels was used to model the in-cylinder flows and combustion process, and it was validated on a high-speed direct-injection engine with a second-generation common-rail fuel injection system. The engine's performance, in-cylinder flow, and combustion, and emission characteristics were analysed at maximum power and maximum torque conditions and at ...
We study from a critical perspective several quantum-electrodynamic phenomena commonly related to vacuum electromagnetic (EM) fluctuations in complex media. We compute the resonance-shift, the spontaneous emission rate, the local density of states and the van-der-Waals-Casimir pressure in a dielectric medium using a microscopic diagrammatic approach. We find, in agreement with some recent works, that these effects cannot be attributed to variations on the energy of the EM vacuum but to variations of the dielectric self-energy. This energy is the result of the interaction of the bare polarizability of the dielectric constituents with the EM fluctuations of an actually polarized vacuum. We have found an exact expression for the spectrum of these fluctuations in a statistically homogeneous dielectric. Those fluctuations turn out to be different to the ones of normal radiative modes. It is the latter that carry the zero-point-energy (ZPE). ...
The performance of a thermophotovoltaic (TPV) converter for solar energy is compared with that of direct solar energy conversion by silicon and germanium solar cells. The optical selectivity of an intermediate emitter is computed. Experimental results on selective emission, based on selectively emitting materials and on antireflection coatings on metals, are reported. For a TPV converter equipped with silicon solar cells, no selective emitter is found to yield better results than would be obtained by direct conversion. A TPV converter with germanium cells operating with a ThO/sub 2/-coated tungsten emitter, however, may achieve a conversion efficiency superior to that of direct solar energy conversion by either silicon or germanium solar cells.
Positron-emission tomography (PET) and PET/CT (computed tomography) are becoming increasingly important for diagnosis and treatment of cancer. Clinically relevant changes can sometimes be seen on PET that are not seen on other imaging modalities. However, PET is not suitable for guiding biopsy as the images are not obtained in real-time. Therefore, our research group has begun developing a concept for PET/CT-guided interventional procedures. This paper presents the rationale for this concept, outlines our research plan, and includes an initial study to evaluate the relative sensitivity of CT and PET/CT in detecting suspicious lesions. (orig.)
Positron emission tomography (PET) and X-ray computed tomography (CT) performed with PET/CT cameras allow us to obtain concurrently information on the presence and degree of alterations of myocardial perfusion and metabolism and on coronary arteries calcification. Furthermore, by gated myocardial perfusion studies, PET may provide crucial information on regional coronary blood flow reserve and endothelial dysfunction. A number of recent papers provide some insight on the potential of PET/CT in cardiology and in the assessment of various cardiovascular diseases including various types of vasculitis and metabolic diseases.
This book presents the basic ideas of the physics of non-gravitational perturbations and the mathematics required to compute their orbital effects. It conveys the relevance of the different problems that must be solved to achieve a given level of accuracy in orbit determination and in recovery of geophysically significant parameters. Selected Contents are: Orders of Magnitude of the Perturbing Forces, Tides and Apparent Forces, Tools from Celestial Mechanics, Solar Radiation Pressure-Direct Effects: Satellite-Solar Radiation Interaction, Long-Term Effects on Semi-Major Axis, Radiation Pressure-Indirect Effects: Earth-Reflected Radiation Pressure, Anisotropic Thermal Emission, Drag: Orbital Perturbations by a Drag-Like Force, and Charged Particle Drag.
Knock limitations are investigated using natural gas, with diesel pilot ignition, as a fuel for the 3406 DI-TA Caterpillar diesel engine. Thermodynamic properties at TDC are generated by computer and compared with experimental results. Exhaust emissions are analyzed. A comparison is made of dual-fuel operation relative to diesel. Observations are made to determine the onset of knock. The onset of knock is characterized as a function of engine speed, load, inlet manifold temperature, and air-fuel ratio (A/F). The conditions at the inset of knock are determined using cylinder pressure data. The most efficient operating range is determined with knock avoidance as a prime parameter.
Single photon emissioncomputed tomography (SPECT) of lung perfusions permits to map functioning lung parenchyma with higher sensitivity than CT. Delivering higher radiations doses it used to increase local control in lung carcinoma; this strategy is based on radiobiological and clinical studies. Lung parenchyma is a dose-limiting tissue in patients irradiated for lung cancer. Functional mapping based on SPECT and CT findings permits to design radiation beams such as to minimize irradiation of functioning lung.
We describe the development of a fully coupled climate model configuration where the Community Climate System Model (CCSM) has been coupled with the VERDE (Visualizing Energy Resources Dynamically on the Earth) analysis modules that compute the response of the electric grid to temperature drivers. The VERDE model includes datasets characterizing the 26,500 sub-stations and 6,000 power generation stations fuel mix, efficiency, service areas, and future performance and these have been geo-located on a 1.4 degree latitude by 1.4 degree longitude CCSM grid (T85). The total electric customers have been computed using conversions derived from economic structure and population data. The carbon emissions per customer and the power generation in megawatts electric (MWe) have also been placed on reconciled 1 km, 4 km and the T85 climate model grid. The CCSM temperature for the present and future have been extracted from the climate ...
During a number of years research and development projects have been made to present methods of monitoring the grate in a grate fired boiler. The monitoring is interesting in order to be able to increase efficiency, increase burn-out of ash, improve the status of emissions, improve transportation of ash and fuel through the furnace, reduce costs for operation and maintenance, handle greater loads etc. Improvement of the combustion has been concentrated to the development of the gas phase combustion. In the past few years the computer development has progressed rapidly and the use of optical monitoring methods have been made possible for monitoring grates. To analyse state of the art of optical grate monitoring systems three different methods have been used, literature search, inquiry where plant owners were asked if they have used grate monitoring systems and if so what experiences they have, and interviews with scientists and users. The ...
Purpose: Cardiomyopathy is one of the major complications of {beta} thalassaemia major as a result of transfusion iron overload. The aim of our study is to evaluate with MR if there is any difference of iron deposition signal intensity (SI) or distribution between non-cardiopatic and cardiopatic thalassaemic patients in order to establish if there is a relationship between cardiopathy and iron deposition. Materials and methods: We studied 20 patients affected by {beta} thalassaemia major, of whom 10 cardiopatic and 10 non-cardiopatic, and 10 healthy volunteers as control group. Serum ferritin and left ventricular ejection fraction were calculated in thalassaemic patients. All patients were examinated using a 1.5 MR unit with ECG-gated GE cine-MR T2*-weighted, SE T1-weighted and GE T2*-weighted sequences. In all cases, using an adequate ROI, the myocardial and skeletal muscle signal intensity (SI), the myocardial/skeletal muscle signal intensity radio (SIR) and the ...
The release of any potential radioactive pollutant to the environment during routine operation of a Nuclear Power Plant should be the subject of appropriate controls and assessments. It is impossible to monitor directly the dose contribution of normal releases because the environmental radioactivity levels are very small but source monitoring provides a means of assessing the radiation exposure of population groups, critical groups and individual members of the public. Derived emissions limits ( DELs ) are used to quantify the relationship between releases of radioactivity and doses to public - critical groups. CNE Cernavoda DELs are based on a pathway analysis conducted for Cernavoda site specific conditions and they were computed using a compartment transfer model. Annual air and water emissions for the most significant radionuclides between 1997 and 2008 are presented in terms of doses and can be observed that population ...
This paper describes Fuji computed radiography (FCR) of Fuji Film for NDT (non-destructive testing). Imaging plate (IP) is a two-dimensional detector of X-ray, and shows higher photographic sensitivity than X-ray film. The output emission of IP provides a good linear relationship to X-ray intensity in a wide intensity range. When this emission can be digitized, the X-ray intensity can be also digitized. IP is applied to NDT as an inspection using X-ray. FCR provides higher photographic sensitivity than the conventional X-ray film method, which results in one-fifth to one-twentieth of irradiation time. Images with stable density can be obtained independent of the intensity. Since IP has a wide dynamic range, the variation of X-ray intensity of 1:500 can be expressed in a single image by single shot. High density record including 1000 images can be done using a 5.25 inch optical disk through the digital image processing and ...
The auroras on Jupiter and Saturn can be studied with a high sensitivity and resolution by the Hubble Space Telescope (HST) ultraviolet (UV) and far-ultraviolet (FUV) Space Telescope spectrograph (STIS) and Advanced Camera for Surveys (ACS) instruments. We present results of automatic detection and segmentation of Jupiter's auroral emissions as observed by HST ACS instrument with VOronoi Image SEgmentation (VOISE). VOISE is a dynamic algorithm for partitioning the underlying pixel grid of an image into regions according to a prescribed homogeneity criterion. The algorithm consists of an iterative procedure that dynamically constructs a tessellation of the image plane based on a Voronoi Diagram, until the intensity of the underlying image within each region is classified as homogeneous. The computed tessellations allow the extraction of quantitative information about the auroral features such as mean intensity, latitudinal and longitudinal ...
Hidden Markov models (HMMs) are probabilistic functions of finite Markov chains, or, put in other words, state space models with finite state space. In this paper we examine subspace estimation methods for HMMs whose output lies a finite set as well. In particular we study the geometric structure arising from the non-minimality of the linear state space representation of HMMs, and consistency of a subspace algorithm arising from a certain factorisation of the singular value decomposition of the estimated linear prediction matrix. For this algorithm we show that the estimates of the transition and emission probability matrices are consistent up to a similarity transformation, and that the m-step linear predictor computed from the estimated system matrices is consistent, i.e. converges to the true optimal linear m-step predictor.
A new theory has been developed to calculate the steady state temperature profile in a cylindrical sample positioned along the entire axis of a cylindrical microwave cavity. Temperature profiles were computed for alumina rods of various radii contained in a cavity excited in one of the TM{sub 0n0} modes with n = 1, 2 or 3. Calculations were also performed with a concentric outer cylindrical tube surrounding the rod to investigate hybrid treating. The parametric studies of the total sample center and surface temperatures were performed as a function of the total power transmitted into the cavity. Also, the total hemispherical emissivity was varied at boundaries of the rod, surrounding tube, and cavity walls. The results are discussed in the context of controlling the average rod temperature and the temperature distribution in the rod during microwave processing.
Study Type - Therapy (case series)Level of Evidence 4 OBJECTIVE To present our experience of retroperitoneoscopic partial adrenalectomy (RPA) for small adrenal tumours, as with modern imaging methods small adrenal lesions are being diagnosed more commonly, and retroperitoneoscopic adrenal surgery for small adrenal tumours (PATIENTS AND METHODS We retrospectively reviewed the records of 389 consecutive retroperitoneoscopic adrenalectomies from September 2005 to December 2008, 88 of which were small adrenal tumours and treated by RPA. Ultrasonography and computed tomography (CT) were used in all patients before RPA, and magnetic resonance imaging or positron emission tomography/CT in some patients. We used RPA for adrenal tumours and total adrenalectomy for adrenal cancer. During the surgery...
In developing new brain imaging agents for single photon emissioncomputed tomography (SPECT), we synthesized eleven radioiodinated phenoxyacetic acid derivatives and investigated the relationship between the chemical structure and in vivo characteristics. Biodistribution studies in mice revealed high initial brain uptake for all the compounds. Blood radioactivity level depended markedly upon the chemical stability of the compound. The alpha,alpha-dimethylester derivative, amide derivatives and diamine derivatives, which were stable to hydrolysis, showed low blood activity levels following intravenous administration. Disappearance of the ester and amide compounds from the brain was rapid. However, the diamine derivatives displayed improved retention in the brain. Compounds 3a and 4 possessed the best combination of high brain uptake and sufficient retention to be useful as potential brain imaging radiopharmaceuticals with SPECT devices.
A series of four 125I-labeled 1-substituted-4-phenylpiperazines were prepared and evaluated in rats as potential brain imaging agents. The compounds were labeled using (125I)iodide/chloramine-T or iodine monochloride and isolated in 48-60% radiochemical yields. The tissue distribution studies indicated that a butyrophenone derivative demonstrated the best overall brain-imaging properties. Compared with the compounds having other 1-substituents this agent had a more prolonged retention of activity in the brain and higher brain-to-blood ratios over the 4-h period studied. The in vivo behavior of this agent is comparable to that of radioiodinated N-isopropyl-p-iodoamphetamine, and, because it can be labeled directly via electrophilic methods, it has substantial potential for use in brain imaging with single photon emissioncomputed tomography.
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...
Selective catalytic reduction (SCR) is a method of reducing the emissions of nitrogen oxides into the atmosphere. Peerless Manufacturing Co. specialises in designing and building SCR systems. The company uses fluid flow modelling to design systems, creating physical and/or numerical flow models to normalise the flow and eliminate potential problems. Computational fluid dynamics (CFD) is used to visualise fluid flow within SCR units and other types of equipment involving phase separators, air intake systems etc. An example is given of use of the commercial CFD code FLUENT to create a full-scale model of an SCR unit so its design could be modified for optimum performance. 1 fig., 1 photo.
Efforts in industry concerning pollution abatement up to nowadays were aimed at: solid particles contained in gaseous effluents, SO_2 effluent reduction, nitrogen oxide effluent limitation through combustion technology enhancement. Various CO_2 emission scenarios with different energy production means (same or increased nuclear plant number, energy consumption reduction) show that energy conservation schemes for the developed countries are the best solution to CO_2 control. Different solutions for greenhouse gas abatement from industrial plant are reviewed: effluent processing, burner technological enhancement, heat transfer optimization on industrial processes, computer assisted management for industrial processes, plasma technic for refining, substitution of gas to oil in chemistry, etc.
Particle accelerators are constructed and operated for a wide variety of applications. In particle physics - the branch of physics that studies the elementary constituents of matter and forces between them - high energy accelerators are used to look deep into the structure of matter. Medical particle accelerators are used for example in medicine to treat tumours [31], in imaging techniques such as Positron Emission Tomography (PET) [24], or for the radio-isotopes production. They also serve in many other industrial branches, e.g. geology, radiocarbon dating [39], molecular complex spectroscopy, lithography, food preservation etc. The eld of accelerator technology draws knowledge and expertise from a wide range of scientic disciplines and uses the latest technical knowledge. The incomplete list of covered disciplines includes mathematics, physics, electronics, computing, electromagnetic eld technology, microwave technology, cryogenics, vacuum ...
Two-dimensional simulations of the coarsening process of the isotropic/smectic-A phase transition are presented using a high-order Landau-de Gennes type free energy model. Defect annihilation laws for smectic disclinations, elementary dislocations, and total dislocation content are determined. The computed evolution of the orientational correlation length and disclination density is found to be in agreement with previous experimental observations showing that disclination interactions dominate the coarsening process. The mechanism of smectic disclination movement, limited by the absorption and emission of elementary dislocations, is found to be facilitated by curvature walls connecting interacting disclinations. At intermediate times in the coarsening process, split-core dislocation formation and interactions displaying an effective disclination quadrupole configuration are observed. This work provides the framework for further understanding of ...
We study D-branes in a two-dimensional lorentzian orbifold R{sup 1,1}/{gamma} with a discrete boost {gamma}. This space is known as Misner or Milne space, and includes big crunch/big bang singularity. In this space, there are D0-branes in spiral orbits and D1-branes with or without flux on them. In particular, we observe imaginary parts of partition functions, and interpret them as the rates of open string pair creation for D0-branes and emission of winding closed strings for D1-branes. These phenomena occur due to the time-dependence of the background. Open string 2{yields}2 scattering amplitude on a D1-brane is also computed and found to be less singular than closed string case.
Nowadays, diamond and the nitrogen-vacancy (NV) colour centres constitute the best solid-state system in view of quantum-computing applications. It has also been shown recently that single NV centres could be used as nanoscale magnetic sensors. Such applications require the creation of single NV centres with very high resolution and with a high efficiency. The nano-implanter at the university of Bochum provides low energy nitrogen ions which can be implanted through a hole pierced in the tip of an atomic force microscope. Ultrapure diamond samples have been implanted with spot sizes of 50nm and less. Stimulated Emission Depletion (STED) microscopy has been used to characterise and resolve the implanted spots.
In order to optimize the production of "2"0"1Tl and "6"7Ga using the (p, xn) reactions on enriched "2"0"3Tl and "6"8Zn targets we established a new set of cross section curves for the most relevant reactions. Target stacks made of up to 15 thin (50 #mu#m) natural Tl or Zn foils interleaved with brass degradation foils were irradiated with incident proton energies from 42 to 10 MeV in overlapping experiments. Yields for "2"0"0","2"0"1","2"0"2"m","2"0"3","2"0"4"mPB and "6"6","6"7","6"8Ga were computed from measured #gamma# emission rates. Where possible, cross section curves for the nuclear reactions involved were computed. Thick target yields and contamination ratios for enriched targets were derived and show good agreement with results from actual production runs. (orig.).
Selective alveolo-bronchography (SAB) has been routinely used to evaluate anatomical changes in the bronchiole and its distal air spaces. A narrowing of the bronchiole and abnormal pooling of contrast medium in the destroyed air space are the prime findings. Since the object of radiography is extremely thin, direct magnification radiography is mandatory to obtain radiologic details. However, the problem with this technique is that radiographic quality varies depending upon the size of the patient and the concentration of contrast medium to be introduced in the lung. This study had two goals. One was to improve the image quality of SAB by Fuji Computed Radiography (FCR). FCR provides radiographs with a good contrast and stable density throughout a wide range of exposure factors which occur in the use of SAB. The other goal was to separately evaluate morphological abnormalities in the outer and inner zones of the lung using X-ray CT. This idea was derived from our ...
To assess the diagnostic capability Fuji computed radiography (FCR) using a dual side reading system was compared to the conventional radiography using a film-screen system. Twenty-eight patients with lung cancer were examined with a new FCR system (FCR 5501D) and a conventional screen-film system concurrently. FCR utilizes a reading system that detects emissions from dual sides of imaging plate. Chest X-rays were obtained with same exposure factors in both systems. Image qualities of both systems were compared by two radiologists using a five-level score. There were no lesion that FCR images were inferior to film-screen images. The frequency of score +1 or +2 that FCR images were superior to film-screen images was 31% in large nodular shadows, 40% in accompanying shadows with a nodule, 67% of small nodular shadows, and 43% of the lymph node swelling in the hilum of the lung or mediastinum. In large nodular shadows which were the most frequent ...
Cardiac disease research relies increasingly on small animal models and non-invasive imaging methods such as positron emission tomography (PET) and magnetic resonance imaging (MRI). Delayed enhancement magnetic resonance imaging (DE-MRI) using gadolinium-based contrast agents appear to be a visualizing infracted myocardium with high spatial resolution. Polar map (or bull's-eye image) was used to determination of the myocardial infarction area. Polar map is a comprehensive interpretation of the left ventricle. The infarct size was computed as the fraction of the total polar map areas. The threshold was computed as the percentage of mean intensity of the normal region. In other study, 50% predefined threshold value in varying range (30?70%) was most commonly use. However, predefined threshold value isn't acceptance in all case. The purpose of this study was to investigate methodological approach for automatic measurement of ...
A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF{sub 2}, and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In addition, the new model ...
A unified physically based ion implantation damage model has been developed which successfully predicts both the impurity profiles and the damage profiles for a wide range of implant conditions for arsenic, phosphorus, BF_2, and boron implants into single-crystal silicon. In addition, the amorphous layer thicknesses predicted by this new damage model are also in excellent agreement with experimental measurements. This damage model is based on the physics of point defects in silicon, and explicitly simulates the defect production, diffusion, and their interactions which include interstitial-vacancy recombination, clustering of same type of defects, defect-impurity complex formation, emission of mobile defects from clusters, and surface effects for the first time. New computationally efficient algorithms have been developed to overcome the barrier of the excessive computational requirements. In addition, the new model has ...
Computational fluid dynamics are applied to the study of three-dimensional fluid flow in a dense medium plasma reactor (DMPR) under different operating conditions. Reaction mechanisms and rates for the removal of methyl t-butyl ether (MTBE) in a DMPR are developed from experimental data to determine the plasma volume, the rate of interphase mass transfer and the photolysis rate of MTBE via UV emission from the plasma. The simulations utilize the plasma volume determined from the kinetic data to show that the volume of fluid in contact with the plasma in the DMPR only constitutes a maximum of approximately 10% of the fluid intended to be cycled through the plasma tubules. The simulations also predict appreciable pressure gradients on the surface of the pin electrodes, resulting in a small discharge area located away from the region in which the electric field strength is a maximum. This result has been confirmed indirectly through observation in ...
An essential part of fire risk assessment is the analysis of fire hazards and fire propagation. In this work, models and tools for two different aspects of numerical fire simulation have been developed. The primary objectives have been firstly to investigate the possibility of exploiting state-of-the-art fire models within probabilistic fire risk assessments and secondly to develop a computationally efficient solver of thermal radiation for the Fire Dynamics Simulator (FDS) code. In the first part of the work, an engineering tool for probabilistic fire risk assessment has been developed. The tool can be used to perform Monte Carlo simulations of fires and is called the Probabilistic Fire Simulator (PFS). In Monte Carlo simulation, the simulations are repeated multiple times, covering the whole range of variability of the input parameters and thus resulting in a distribution of results covering what can be expected in reality. In practical applications, advanced ...
Sources of industrial emissions of 1,3-butadiene are discussed both by process (production, consumers) and type (equipment leaks, point sources). Quantification of the emissions are presented, as reported...Full Text Available
It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emissioncomputed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have selected the key areas which ...
Lawrence Livermore, Sandia Livermore and Los Alamos National Laboratories have a joint project to develop an optimized hydrogen fueled engine for series hybrid automobiles. The major divisions of responsibility are: system analysis, engine design and kinetics modeling by LLNL; performance and emission testing, and friction reduction by SNL; computational fluid mechanics and combustion modeling by LANL. This project is a component of the Department of Energy, Office of Utility Technology, National Hydrogen Program. We report here on the progress on system analysis and preliminary engine testing. We have done system studies of series hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. The impact of various on-board storage options on fuel economy are evaluated. Experiments with an ...
Lawrence Livermore, Sandia Livermore and Los Alamos National Laboratories have a joint project to develop an optimized hydrogen fueled engine for series hybrid automobiles. The major divisions of responsibility are: system analysis, engine design and kinetics modeling by LLNL; performance and emission testing, and friction reduction by SNL; computational fluid mechanics and combustion modeling by LANL. This project is a component of the Department of Energy, Office of Utility Technology, National Hydrogen Program. We report here on the progress on system analysis and preliminary engine testing. We have done system studies of series hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. The impact of various on-board storage options on fuel economy are evaluated. Experiments with an ...
The Kyoto Protocol foresees emission trading but does not yet specify verification of (uncertain) emissions. This paper analyses a setting in which parties can meet their emission targets by reducing emissions, by investing in monitoring (reducing uncertainty of emissions) or by (bilaterally) trading permits. We derive the optimality conditions and carry out various numerical simulations. Our applications suggest that including uncertainty could increase compliance costs for the USA, Japan and the European Union. Central Europe and the Former Soviet Union might be able to gain from trading due to higher permit prices. Emissions trading could also lower aggregate uncertainty on emissions.
Full text: Radiotherapy treatment planning (RTP) relies heavily on medical imaging. Until recently, the most important planning tool was the treatment simulator. The kilovoltage radiographic capabilities in a treatment simulator enabled the boundaries of treatment fields to be visualized with respect to bony anatomic landmarks. Perhaps the most important advance in treatment planning in recent years is the ability to visualize the passage of the beams with respect to a more accurate geometrical representation of the tumor and other soft tissue structures. This 'virtual simulation' uses a computer-based representation of a patient to determine the extent of the disease and the location of radiation sensitive normal tissue. Computer tomographic (CT) imaging produces a high-resolution three-dimensional representation of anatomy that can be correlated with other image sets such as magnetic resonance images (MRI) of function. Positron ...
Jun 16, 2011 ... The research is part of a team effort to help the hardwood sawmill industry automate with computer vision systems, and computer-aided or ...
Currently, x-ray mammography is the method of choice in breast cancer screening programmes. As the mammography technology moves from 2D imaging modalities to 3D, conventional computational phantoms do not have sufficient detail to support the studies of these advanced imaging systems. Studies of these 3D imaging systems call for a realistic and sophisticated computational model of the breast. DeBRa (Detailed Breast model for Radiological studies) is the most advanced, detailed, 3D computational model of the breast developed recently for breast imaging studies. A DeBRa phantom can be constructed to model a compressed breast, as in film/screen, digital mammography and digital breast tomosynthesis studies, or a non-compressed breast as in positron emission mammography and breast CT studies. Both the cranial-caudal and mediolateral oblique views can be modelled. The anatomical details inside the phantom ...
The 8 papers in the report deal with the following areas: Introduction to diesel particulate emissions, alternative fuels, and the transit industry; Technical problems and policy issues associated with the 1991 bus emissions standards; Reducing transit bus emissions: comparative costs and benefits of methanol, particulate traps, and fuel modification; Effects of applying emissions averaging, trading, and banking to transit buses; Strategic review of heavy-duty engine emission regulations and alternate fuels; Meeting bus emissions standards--a perspective; Economic evaluation of bus maintenance contracting; Objectives for a transit-bus-fleet management data, information, and knowledge exchange.
The use of the ratio of the characteristic intensity to the continuum background intensity (P/B ratio) of the X-ray spectrum for a quantitative ion microprobe (IMP) or PIXE (particle induced X-ray emission) analysis of thin biological specimens was proposed previously. The IMP analysis of thick biological specimens is also of considerable practical use. In this paper, the possibility of using the P/B ratio to quantify minor elements in thick biological specimens is investigated. The epoxy resin based standards with gradual concentrations of KCNS up to 0.6 mol/kg and NBS bovine liver were analyzed by a 27 MeV {alpha} particle microprobe. The measured peak to background ratios (between 4.4 to 5.7 keV) agreed well with the theoretical calculations. The calculations showed that the concentration dependence of the P/B ratios was determined mainly by the absorption of X-rays in specimens. The results indicate that the P/B method is useful for IMP analysis of thick ...
The introduction of positron emission tomography (PET)/magnetic resonance (MR) systems into medical practice in the foreseeable future may not only lead to a gain in clinical diagnosis compared to PET/computed tomography (CT) imaging due to the superior soft-tissue contrast of the MR technology but can also substantially reduce exposure of patients to ionizing radiation. On the other hand, there are also risks and health effects associated with the use of diagnostic MR devices that have to be considered carefully. This review article summarizes biophysical and biological aspects, which are of relevance for the assessment of health effects related to the exposure of patients to both ionizing radiation in PET and magnetic and electromagnetic fields in MR. On this basis, some considerations concerning the justification and optimization of PET/MR examinations are presented - as far as this is possible at this very early stage. Current safety ...
In developing new brain imaging agents for single photon emissioncomputed tomography (SPECT), we synthesized eleven radioiodinated phenoxyacetic acid derivatives and investigated the relationship between the chemical structure and in vivo characteristics. Biodistribution studies in mice revealed high initial brain uptake for all the compounds. Blood radioactivity level depended markedly upon the chemical stability of the compound. The #alpha#,#alpha#-dimethylester derivative (1e), amide derivatives (2a-c) and diamine derivatives (3a, b, 4), which were stable to hydrolysis, showed low blood activity levels following i.v. administration. Disappearance of the ester and amide compounds from the brain was rapid. However, the diamine derivatives displayed improved retention in the brain. Compounds 3a and 4 possessed the best combination of high brain uptake and sufficient retention to be useful as potential brain imaging radiopharmaceuticals with ...
To address the need for integrated models of advanced power generation systems and for improved analysis techniques, the US Department of Energy (DOE), through the Morgantown Energy Technology Center (METC), has supported the development of performance, emissions, and cost models of several advanced power generation systems, including integrated gasification combined cycle (IGCC), externally-fired combined cycle (EFCC) and pressurized fluidized bed combustion (PFBC) concepts. Simultaneously, numerical methods for simulation of uncertainties and optimization of process flowsheets have been implemented in the DOE`s public version of ASPEN. The new process models and computational capabilities have been applied to demonstrate the benefits of quantitative approaches to dealing with uncertainty and for optimizing technologies in the face of uncertainty. This paper focuses on modeling and assessment of the EFCC system concept. The purpose of the ...
A computer model of cryogenic system for storing solid antimatter is used to explore the radiative cooling-power requirements for long-term antimatter storage. If vacuum-chamber pressures as low as 10 to -18th power torr can be reached, and the rest of the large set of assumptions is valid, milligram quantities of solid antimatter could be stored indefinitely at 1.5 K using cooling powers of less than a microwatt. Many of the assumptions made are problematic and need verification, as they could potentially change the results greatly. The system modeled is a sphere of solid anti-parahydrogen at 1.5 K or below levitated in a spherical cryogenic vacuum chamber. The free matter gas in the chamber is assumed to be molecular hydrogen, and sublimation of both matter and antimatter is assumed to be negligible. The antihydrogen is assumed to be in thermal equilibrium, although annihilation-energy deposition is localized and hydrogen's thermal-impulse response time ...
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with prototype animal PET/MRI ...
We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessive current in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K < 1, for spontaneous radiation emitted along the axis of the system. The emission at harmonics f > 1 is greatly enhanced for the approximate square-wave magnetic profile: the ratio of the ...
Premature fusion of multiple cranial sutures has been associated with increased intracranial pressure and the potential for mental impairment. Isolated craniosynostosis, however, is considered a benign condition primarily reconstructed for aesthetic purposes. A comparative analysis, to assess the differences between pre- and post operatory cerebral perfusion of patients who underwent surgery for simple cranisynostosis, was performed using single positron emissioncomputed tomography ''SPECT'' Images. Cerebral blood flow studies were performed using "9"9"mTc-HMPAO SPECT in children with simple cranisynotoses. The subjects were 8 children with craniosynostosis (age, 2 months-9 years). Preoperative revealed regional hypovascularity in the cerebral hemisphere in 5 cases (62%). In 6 patients the cerebral blood flow normalized or increased after craniofacial reconstruction. We demonstrated the presence of regional hypovascularity in the cerebral ...
Modern imaging technologies visualize different aspects of disease in a non-invasive way. Considerable progress has been made in the fusion of images from different imaging modalities using software approaches. One goal of fusion software is to align anatomical and functional images and allow improved spatial localization of abnormalities. The resulting correlation of the anatomical and functional images may clarify the nature of the abnormality and help diagnose or stage the underlying disease. Whereas successful image fusion software has been developed for the brain, only limited success has been achieved for image alignment in other parts of the body. The development and current status of alternative approaches are presented. Dual-modality imaging is described with devices where two modalities are combined and mounted in a single gantry. The use of existing scanner technology ensures that no compromises are made in the clinical efficacy of either the anatomical or functional imaging ...
Chemical looping combustion (CLC) is a process in which an oxygen carrier is used for fuel combustion instead of air or pure oxygen as shown in the figure below. The combustion is split into air and fuel reactors where the oxidation of the oxygen carrier and the reduction of the oxidized metal occur respectively. The CLC system provides a sequestration-ready CO2 stream with no additional energy required for separation. This major advantage places combustion looping at the leading edge of a possible shift in strict control of CO2 emissions from power plants. Research in this novel technology has been focused in three distinct areas: techno-economic evaluations, integration of the system into power plant concepts, and experimental development of oxygen carrier metals such as Fe, Ni, Mn, Cu, and Ca. Our recent thorough literature review shows that multiphase fluid dynamics modeling for CLC is not available in the open literature. Here, we have modified ...
In the search for new brain imaging agents for use with single photon emissioncomputed tomography (SPECT), quantitative structure activity relationship (QSAR) analysis of the correlations between initial brain uptake and physicochemical parameters like lipophilicity, log P, molecular weight, log MW and log U/D (undissociated/dissociated), of the {sup 99m}Tc-DADT (diaminedithiol) complexes and {sup 99m}Tc-PAO (propyleneaminoxime) complexes have been analyzed. High correlations are found for both the {sup 99m}Tc-DADT complexes (r = 0.94) and for the {sup 99m}Tc-PAO complexes (r = 0.83) which are significant at 99.9 and 99.5 percentile level, respectively. These results will help the further design of better ligands for {sup 99m}Tc in brain imaging. (author).
The results of an experimental investigation of the performance of a small bore engine with a swirl chamber when operating as a dual fuel engine with commercial methane as the gaseous fuel were presented in this paper. The experiment involved using a 3-dimensional computational fluid dynamics model to predict the performance of the engine. A detailed chemical kinetics for the gaseous fuel component, consisting primarily of methane and a reduced detailed chemical kinetics for the diesel fuel while considering the turbulent combustion processes an associated performance of a dual fuel engine with a swirl chamber were incorporated in the simulation. The study experimentally and numerically investigated the effects of changes in the quantities of the liquid fuel pilot and gaseous fuels on the combustion processes, engine performance, cyclic variations, and emissions. The paper discussed the experimental approach and results. It also discussed the ...
Integration of positron emission tomography (PET) and magnetic resonance (MR) has become a topic of increasing interest to the imaging community over the past two years. In this text, the authors attempt to distinguish facts from fiction concerning such integrated systems. Analysis of existing information of combined imaging on existing brain PET/MR systems and imaging experience with PET-computed tomography (CT) is reviewed. Various types of system integration of PET and MR are discussed with completely independent systems on one hand and completely integrated systems with the possibility of simultaneous data acquisition on the other hand. Furthermore, it is discussed, what simultaneous data acquisition with nuclear imaging systems combined with MR or CT really means, as technical simultaneity may not be relevant in light of the pharmacokinetics of the nuclear tracers used. The authors conclude that combining PET/MR is an interesting research ...
Quantum computers hold great promises for the future of computation. In this paper, this new kind of computing device is presented, together with a short survey of the status of research in this field. The principal algorithms are introduced, with an emphasis on the applications of quantum computing to physics. Experimental implementations are also briefly discussed.
The resulting emissions of the firing of ceramic products of all type are described, the factors are enumerated to diminish the emissions in the kilns and the technologies applied in the kilns to reduce these emissions while carrying out energy saving are described briefly. (author)
To evaluate the role of positron emission tomography-computed tomography (PET-CT) in staging and determining early treatment response to chemotherapy in children with neuroblastoma (NB) and its correlation with the final outcome. Patients and Methods: Seventeen patients of NB with mean age of 51.5 months (age range 2-132 months; 14 males, 3 females) underwent serial "1"8F-fluorodeoxyglucose (FDG) PET-CT imaging. All 17 patients were for staging before any treatment. Twelve of 17 patients underwent "1"3"1I meta-iodobezylguanidine (MIBG) scan and bone scan. MIBG uptake was seen in the primary lesion in 11/12 patients. MIBG uptake in bones was seen in 3/12 patients. All bone lesions were concordant on MIBG and bone scan. Early response to chemotherapy was evaluated after two cycles using PET-CT. A 30% reduction in longest diameter was taken as cut-off value for response on CT based on the response evaluation criteria in solid tumors criteria. ...
Colerectal cancer (CRC) is the second commonest cancer in the Western World. Successful treatment relies significantly on accurate detection and staging of primary disease as well as the early identification of the presence and extent of recurrence. Morphological imaging techniques, particularly computed tomography (CT), are well established and widely available to carry out these tasks in addition to predicting and monitoring response to therapy. This review analyses the current inadequacies for imaging CRC and critically assesses the potential role of functional imaging with positron emission tomography (PET). It was reviewed the current literature, to use the experience from the firs 1000 PET studies carried out at the institution and the perspective of surgical colleagues. It was found little evidence for the use of 2-["1"8F]fluoro-2-deoxy-D-glucose (FDG)-PET for screening asymptomatic individuals and current modalities appear better suited ...
Tumor-targeted monoclonal antibodies (mAb) might be useful as diagnostic or therapeutic agents when linked to cytotoxic or imaging reagents. Our group is working to test this hypothesis by linking cytocidal and image-producing isotopes to mAb and testing the utility of the radioimmunoconjugates formed in animal model systems. Radioiodines were first employed for these purposes,but unfavorable nuclear properties (half-lives, #gamma#-ray and #beta#-particle energies) and chemical reactivity (deiodination in vivo) limit their utility. Labeling immunoproteins with metallic radionuclides offers more versatility in that the selection of potentially useful radiometals spans the periodic table.Of the metallic radionuclides with physical properties most suited for use with mAb in nuclear medicine, few are more available or desirable than those of bismuth ("2"1"2Bi) and lead ("2"0"3Pb, "2"1"2Pb), as listed in Table 1. "2"1"2Bi or "2"1"2Pb could serve as sources for highly cytocidal ...
Iron is one of the main constituents of stainless steel which is used as a structural material in nuclear reactors. In fast and conceptual fusion and fusion-fission hybrid systems the primary energy range of neutron interaction lies between 1 and 20 MeV which opens up several reaction channels. The reaction cross-sections in this energy range are important for dosimetry, radiation damage, neutronics and safety studies of nuclear reactors. Keeping this in view Nuclear Data Section of the International Atomic Energy Agency has sponsored a Research Co-ordination Programme on Methods for the Calculation of Fast Neutron Nuclear Data for Structural Elements. Under this programme we propose to study (n,n'), (n,2n), (n,3n), (n,p), (n,np), (n,pn), (n,#alpha#), (n,n#alpha#), (n,#alpha#n) and (n,#gamma#) reaction cross-sections. Besides these, total, elastic and discrete level inelastic scattering cross-sections, angular distributions of neutron production cross-sections, neutron ...
In its current configuration, the IECM provides a capability to model various conventional and advanced processes for controlling air pollutant emissions from coalfired power plants before, during, or after combustion. The principal purpose of the model is to calculate the performance, emissions, and cost of power Plant configurations employing alternative environmental control methods. The model consists of various control technology modules, which may be integrated into a complete utility plant in any desired combination. in conuwt to conventional deterministic models, the IECM offers the unique capability to assign probabilistic values to all model input parameters, and to obtain probabilistic outputs in the form of cumulative distribution functions indicating the likelihood of different costs and performance results. The most recent version of the IECM, implemented on a Macintosh II computer and containing a number of ...
In its current configuration, the IECM provides a capability to model various conventional and advanced processes for controlling air pollutant emissions from coalfired power plants before, during, or after combustion. The principal purpose of the model is to calculate the performance, emissions, and cost of power Plant configurations employing alternative environmental control methods. The model consists of various control technology modules, which may be integrated into a complete utility plant in any desired combination. in conuwt to conventional deterministic models, the IECM offers the unique capability to assign probabilistic values to all model input parameters, and to obtain probabilistic outputs in the form of cumulative distribution functions indicating the likelihood of different costs and performance results. The most recent version of the IECM, implemented on a Macintosh II computer and containing a number of ...
This paper summarizes the current scientific and technological knowledge about greenhouse gas emissions from various agricultural practices and the manufacturing of food. The study also provides estimates that compare agriculture-related alternatives for reducing greenhouse gas emissions.
In this study, a regional dynamical model (WRF) is used to drive biogenic emission models to calculate high resolution (10 x 10 km) biogenic emissions of isoprene (C_5H_8), monoterpenes (C_1H_1_6), and nitric oxide (NO) in China. This high resolution biogenic inventory will be available for the community to study the effect of biogenic emissions on photochemical oxidants in China. The biogenic emissions are compared to anthropogenic emissions to gain insight on the potential impact of the biogenic emissions on tropospheric chemistry, especially ozone production in this region. The results show that the biogenic emissions in China exhibit strongly diurnal, seasonal, and spatial variations. The isoprenoid (including both isoprene and monoterpenes) emissions are closely correlated to tree density and strongly vary with ...
Three independent studies have been conducted for assessing the impact of rocket launches on the earth`s environment. These studies have addressed issues of acid rain in the troposphere, ozone depletion in the stratosphere, toxicity of chemical rocket exhaust products, and the potential impact on global warming from carbon dioxide emissions from rocket launches. Local, regional, and global impact assessments were examined and compared with both natural sources and anthropogenic sources of known atmospheric pollutants with the following conclusions: (1) Neither solid nor liquid rocket launches have a significant impact on the earth`s global environment, and there is no real significant difference between the two. (2) Regional and local atmospheric impacts are more significant than global impacts, but quickly return to normal background conditions within a few hours after launch. And (3) vastly increased space launch activities equivalent to 50 U.S. Space Shuttles or ...
The kraft recovery boiler is of critical importance for the paper and pulp industry. From only energy point of view, kraft recovery boilers supply more than 50% of total thermal energy consumed in the paper and pulp industry. A kraft recovery boiler has two main functions: firstly to recover the inorganic cooking chemicals in the black liquor for reuse in the pulping process, and secondly to make use of the chemical energy in the organic portion of the black liquor to generate super-heated steam for the plant. The twin objectives of recovering chemicals and energy makes the recovery boiler design and operation more complex than virtually any other boiler application. Thus there is a demand for development of an analytical tool that can be used to predict the performance of a kraft recovery boiler. This paper presents the results achieved from a project jointly financed by Swedish National Energy Administration and the industry (Iggesund Paperboard). In this project, a three-dimensional ...
Gamma scanning measurements are used to determine the radioactive nuclides from an irradiated fuel rod in a hot cell which is a routine task in the Irradiated Materials Examination Facility (IMEF) of the Korea Atomic Energy Research Institute (KAERI), Total gamma spectra of radioactive nuclides and the atomic ratio of {sup 134}Cs to {sup 137}Cs in a few segments of a single fuel rod are measured by the present gamma scanning system. For the purpose of determining the radioactive nuclide's distribution in detail within a fuel rod quantitatively, we attempt to upgrade the present gamma scanning system in this paper, therefore, an investigation of the feasibility of the tomographic gamma scanning (TGS) technique, which is one of the promising nondestructive assay (NDA) methods is proposed. The TGS technique is an efficient method and it has an accurate precision for the characterization of several fuel parameters. In this paper, a principle and an emission ...
As a continuation of its efforts to provide methodologies and tools to Member States to carry out comparative assessment and analyse priority environmental issues related to the development of the electric power sector, the IAEA has completed a new version of the Wien Automatic System Planning (WASP) Package WASP-IV for carrying out power generation expansion planning taking into consideration fuel availability and environmental constraints. This manual constitutes a part of this work and aims to provide users with a guide to use effectively the new version of the model WASP-IV. WASP was originally developed in 1972 by the Tennessee Valley Authority and the Oak Ridge National Laboratory in the USA to meet the IAEA needs to analyse the economic competitiveness of nuclear power in comparison to other generation expansion alternatives for supplying the future electricity requirements of a country or region. Previous versions of the model were used by Member States in many national and ...
A specific application of single photon emission tomography to the relative quantitation of the pituitary region is described together with the results obtained in 19 patients with pituitary adenoma...Full Text Available
activities, including the combustion of diesel fuel in heavy-duty vehicles and jet fuel in aircrafts. Current details on emissions from the transportation and other...
Quantum computing is a quickly growing research field. This article introduces the basic concepts of quantum computing, recent developments in quantum searching, and decoherence in a possible quantum...Full Text Available
We present interactive computer programs for the analysis of nucleic acid sequences. In order to handle these programs, minimum computer experience is sufficient. The nucleotide sequence of the human...Full Text Available
USGS geologists Peter Triezenberg and William Danforth sit with WHOI/LDEO Computer Technician Tom Bolmer in the Healy computer lab. This was during a scientific expedition to map the Arctic seafloor....
A new model for computations is considered which combines the quantum computer with the chaotic dynamics amplifier, based on the logistic map. We discuss the satisfiability problem and argue that the problem can, in principle, be solved in polynomial time if one uses the new model for computations.
One of the central questions of molecular biology is the discovery of the semantics of DNA. This discovery relies in a critical way on a variety of expensive computations. In order to solve these computations, both parallel computers and special-purpose hardware play a major role.
An overview of emissive display technologies is presented. Display types briefly described include: cathode ray tubes (CRTs), field emission displays (FEDs), electroluminescent displays (ELDs), and plasma display panels (PDPs). The critical role of phosphors in further development of the latter three flat panel emissive display technologies is outlined. The need for stable, efficient red, green, and blue phosphors for RGB fall color displays is emphasized.
In this report is described the sources to nitrogen emission and how the emission have changed over time. The cost and effect of the proposals given by the Swedish Environmental Protection Agency to cope with the emission of nitrogen to the sea is also treated. A separate chapter describes what we know today about phosphorus and eutrophication Basic document to report SNV--4735. 25 figs, 11 tabs
Proper estimation of shipping emissions is essential for an impact assessment of shipping on air quality and health in port cities and coastal regions. In the Netherlands shipping is an important source of particulate matter. This report provides an internationally accessible and transparent summary and description of the methodologies used in the Netherlands Pollutant Release and Transfer Register (PRTR) to estimate PM emissions from shipping, including recently implemented updates.
This article analyses the role of energy intensity and the relationship between CO{sub 2} emissions and primary energy in order to explain the evolution of CO{sub 2} emissions by unit of real GDP. It also distinguishes two different meanings of CO{sub 2} emissions Kuznets curve hypothesis: the weak and the strong sense. It considers the case of Spain in the period 1972-1997 as an example in which there is not any evidence supporting this hypothesis in either sense. (author)
This paper reviews emission standards, technologies to control emissions, and the cost of these controls. It is concluded that international bodies will increasingly set minimum emissions, these standards will continue to be reduced, and in addition new substances will be controlled. The cost of this control will likely not exceed 0.5 cents per kWe-hr. 4 refs., 3 tabs.
Pollutant emissions due to fossil fuel and biomass energy utilization in Turkey have been estimated. Standard emission factors were used for estimating the levels of particulate matter, sulfur oxides, nitrogen oxides, carbon monoxide, volatile organic compounds, and aldehydes. The results are presented for different fuels and energy-consuming sectors for the reference year 1987. Total Turkish emissions vs energy consumption are presented for every fifth year since. 1960. (author).
Computer And Network Security: Information For Everyone: This presentation was originally prepared as the 14th talk in a series known as "The Programmer's ...
The costs of greenhouse gas emission-reductions vary among countries depending on emission levels, technologies used, past emission-reduction achievements, path of economic development, fuel mix, and initial endowment of hydrocarbon resources. The criterion of cost-effectiveness therefore suggests that the ways should be found to encourage emission reductions in the countries where the required costs of reduction of additional unit of emissions are the lowest. These countries usually face crucial capital constraints and have other development priorities than investing in reduction of greenhouse gas emissions. Developed countries could invest their resources in the former Soviet Union and the east European countries to achieve the same level of reduction of greenhouse gases with lower costs than they could in their own countries.
Proposed features of the competitive electricity market in Ontario were reviewed. The speaker predicted that demand for renewable energy in Ontario`s competitive electricity market will be affected by green power, emissions trading, labelling, and renewables portfolio standard. Under current regulations retailers can charge customers a premium for purchasing electricity generated by `green` sources. The existing limits on emissions of sulphur dioxide, nitrogen oxides and carbon dioxides will remain in place, but an emissions cap and trading program for all Ontario-based generation is an option to consider. Ontario`s Market Design Committee (MDC) has recommended the implementation of emissions trading for electricity-related air pollutants for all generators located in Ontario. The complex mechanics of emission trading are explained. The MDC recommendation of the use of standard ...
This report focuses on air quality at the Nevada Test Site (NTS) for 1994. A general description of the effluent sources are presented. Each potential source of NTS emissions was characterized by one of the following: (1) by monitoring methods and procedures previously developed at NTS; (2) by a yearly radionuclide inventory of the source, assuming that volatile radionuclides are released to the environment; (3) by the measurement of tritiated water concentration in liquid effluents discharged to containment ponds and assuming all the effluent evaporates over the course of the year to become an air emission; or (4) by using a combination of environmental measurements and CAP88-PC to calculate emissions. Appendices A through J describe the methods used to determine the emissions from the sources. These National Emission Standards for Hazardous Air Pollutants (NESHAP) ...
This study investigates the carbon dioxide (CO2) emissions patterns in coordination with the economic development of Taiwan. The resulting quadratic relationship between emissions and income are partly due to the structural change of energy supply in Taiwan, with the introduction of nuclear energy in 1980 to 1986. This relationship is quite unique and different from the N-shaped relationships in some developed countries (de Bruyn and Opschoor, 1997; Friedl and Getzner, 2003). The CO2 emissions in Taiwan increase with the increasing imports of raw materials for economic activities and the increasing use of electricity. There is no evidence that the substantial increase of Taiwan's service sector contributed to slowing its CO2 emissions.
Method for determining the concentration of atomic species in gases and solids. Measurement of at least two emission intensities from a species in a plasma containing the species after a sufficient time period has elapsed after the generation of the plasma and during a second time period, permits an instantaneous temperature to be established within the sample. The concentration of the atomic species to be determined is then derived from the known emission intensity of a predetermined concentration of that species in the sample at the measured temperature, a quantity which is measured prior to the determination of the unknown concentration, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known concentration within the sample.
There is a need to reduce air pollutant emissions in some U.S. urban regions to meet federal and state air quality guidelines. Opportunities exist for reducing pollutant emissions from natural gas appliances in the residential sector. A cost-benefit analysis on various pollutant-reducing strategies is needed to evaluate these opportunities. The effectiveness of these pollutant-reducing strategies (e.g., low-emission burners, energy conservation) can then be ranked among themselves and compared with other pollutant-reducing strategies available for the region. A key step towards conducting a cost-benefit analysis is to collect information on pollutant emissions from existing residential natural gas appliances. An extensive literature search was conducted to collect data on residential natural-gas-appliance pollutant emission factors. The literature primarily describes laboratory ...
The Computation Directorate at Lawrence Livermore National Laboratory has four major areas of work: (1) Programmatic Support -- Programs are areas which receive funding to develop solutions to problems or advance basic science in their areas (Stockpile Stewardship, Homeland Security, the Human Genome project). Computer scientists are 'matrixed' to these programs to provide computer science support. (2) Livermore Computer Center (LCC) -- Development, support and advanced planning for the large, massively parallel computers, networks and storage facilities used throughout the laboratory. (3) Research -- Computer scientists research advanced solutions for programmatic work and for external contracts and research new HPC hardware solutions. (4) Infrastructure -- Support for thousands of desktop computers and numerous LANs, ...
Ion Beam Induced Luminescence (IBIL) and Ion Beam Induced Charge Collection (IBICC) have been applied in the study of the luminescence emission efficiency and investigation of the homogeneity of the luminescence emission in phosphors. The IBIL imaging was performed by using sharply focused ion beams or broad/partially-focused ion beams. The luminescence emission homogeneity in samples was examined to reveal possible distributed crystal-defects that may lead to the inhomogeneity of the luminescence emission in samples.The purpose of the study is to search for suitable luminescent thin films that have high homogeneity of luminescence emission, large IBIL efficiency under heavy ion excitation, and can be placed as a thin layer on the top of microelectronic devices to be analyzed with Ion Photon Emission Microscopy (IPEM). The emission yield was ...
The objectives of this study were to characterize the changes of VOC material emission profiles over time and develop a method to account for such changes in order to enhance a source identification technique that is based on the measurements of mixed air samples and the emission signatures of individual building materials determined by PTRMS. Source models, including powerlaw model, doubleexponential decay model and mechanistic diffusion model, were employed to track the change of individual material emission signatures by PTRMS over a ninemonth period. Samples of nine typical building materials were tested individually for nine months and later in combination to obtain actual mixture emissions. VOC emissions from each material were measured in a 50liter smallscale chamber. Chamber air was sampled by PTRMS over a 28day period to determine their emission rate ...
To predict air quality properly at a given location, it is necessary to identify all emission sources that will have significant impact at that location. Furthermore, the atmospheric pollutants that are emitted by these sources must be identified and quantitatively characterized. Once the air-quality predictions have been made, it is desirable to have some historical air-quality data for comparison. An efficient means of obtaining this information is through the use of detailed emission inventories and an inventory of air-quality-monitoring stations. Therefore, as part of the Alberta Government/Industry Acid Deposition Research Program (ADRP), three comprehensive inventories have been developed, namely: a sulfur dioxide (SO/sub 2/) emission inventory, a nitrogen oxides (NOx) emission inventory, and an inventory of air-quality-monitoring stations. Volume 2, Design of the Emission ...
This publication describes the modification of the road traffic exhaust emission calculation model LIISA and presents the new calculation results. The model has already established its position as the most important inventory tool for regional road traffic emissions in Finland. The LIISA model calculates road traffic emissions as a whole. The system comprises of three separate models: 1. a model for calculating automobile emissions for the years 2001-2021, 2. a model for calculating emissions backwards for the years 1980-2000, 3. a model for calculating the emissions of motorcycles and mopeds. All three parts have been modified. The LIISA model is one of the submodels of the comprehensive LIPASTO calculation system developed at VTT Building and Transport. The LIPASTO model is an inventory tool for emissions regarding all traffic modes in ...
Environmental computer science is a new partial discipline of applied computer science, which makes use of methods and techniques of information processing in environmental protection. Thanks to the inter-disciplinary nature of environmental problems, computer science acts as a mediator between numerous disciplines and institutions in this sector. The handbook reflects the broad spectrum of state-of-the art environmental computer science. The following important subjects are dealt with: Environmental databases and information systems, environmental monitoring, modelling and simulation, visualization of environmental data and knowledge-based systems in the environmental sector. (orig.).
The main pollutants from marine diesel engines are oxides of nitrogen (NOx), sulfur oxides (SOx) and particulates (soot). However, the proposed marine diesel engine emission regulations will primarily focus on the levels of NOx and SOx. In the future, once the proposed regulations are met, the limits and levels of other emissions will come under increasing scrutiny, such as particulates, hydrocarbons and carbon monoxide. Regardless of the type of pollutant, there are generally two classes of emission control: (1) techniques that reduce the amount of pollutant formed in the combustion process, or (2) prevent the pollutants from reaching the atmosphere. Unfortunately, some of these control techniques will not be able to meet the incoming regulations. Therefore, this paper identifies the diesel engine emissions of concern, the impending regulations, and the merits of current and future ...
Air toxics from the industrial wastewater treatment plants (IWTPs) impose serious health concerns on its surrounding residential neighborhoods. To address such health concerns, one of the key challenges is to quantify the air emissions from the IWTPs. The objective here is to characterize the air emissions from the IWTPs and quantify its associated uncertainty. An IWTP receiving the wastewaters from an airplane maintenance facility is used for illustration with focus on the quantification of air emissions for benzyl alcohol, phenol, methylene chloride, 2-butanone, and acetone. Two general fate models, i.e., WATER9 and TOXCHEM+V3.0 were used to model the IWTP and quantify the air emissions. Monte Carlo and Bootstrap simulation were used for uncertainty analysis. On average, air emissions fr...
Surgical resection is the only curative treatment strategy for intrahepatic cholangiocarcinoma (CC). Therefore, accurate staging is essential for appropriate management of patients with CC. We assessed the usefulness of 2-["1"8F]fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the staging of CC. We undertook a retrospective review of FDG PET images in 21 patients (10 female, 11 male; mean age 57 years) diagnosed with CC. Ten patients had hilar CC and 11, peripheral CC. Patients underwent abdominal magnetic resonance imaging (MRI) (n=20) and computed tomography (CT) (n=12) for the evaluation of primary tumours, and chest radiography and whole-body bone scintigraphy for work-up of distant metastases. For semi-quantitative analysis, the maximum voxel standardised uptake value (SUV_m_a_x) was obtained from the primary tumour. All peripheral CCs showed intensely increased FDG uptake, and some demonstrated ring-shaped uptake ...
The Asia-Pacific region will see tremendous growth in demand for electricity in the next few decades and will be an important market for generation equipment and associated services. The Association of Southeast Asian Nations (ASEAN) countries alone anticipate additional power demand of more than 37,000 NM by the year 2000, with an estimated total expenditure of US $85 billion. Trends in recent years show natural gas-fired combined cycle in plants to be fast gaining in popularity over conventional thermal plants. The advantages include increased primary energy conversion efficiency coupled with significant reduction in pollutant emissions, shorter construction times, faster loading rates and reduced staffing requirements. In the computer model used for generation capacity expansion planning in Tenaga Nasional Berhad, clean coal technology models are not used as candidate plants. In the opinion of the authors, this results from a lack of ...
The WAND (Waste Assay for Nonradioactive Disposal) system can scan thought-to-be-clean, low-density waste (mostly paper and plastics) to determine whether the levels of any contaminant radioactivity are low enough to justify their disposal in normal public landfills or similar facilities. Such a screening would allow probably at least half of the large volume of low-density waste now buried at high cost in LANL`s Rad Waste Landfill (Area G at Technical Area 54) to be disposed of elsewhere at a much lower cost. The WAND System consists of a well-shielded bank of six 5-in.-diam. phoswich scintillation detectors; a mechanical conveyor system that carries a 12-in.-wide layer of either shredded material or packets of paper sheets beneath the bank of detectors; the electronics needed to process the outputs of the detectors; and a small computer to control the whole system and to perform the data analysis. WAND system minimum detectable activities (MDAs) for point sources ...
Coronary angiography provides anatomical information whereas thellium myocardial scintigraphy measures resistive tissue perfusion. Because of this fundamental difference. The authors question the validity of using coronary angiography as the gold standard to judge thellium myocardial scintigraphy. The authors studied 20 patients undergoing elective percutaneous coronary angioplasty who fulfilled the following criteria: (1) history of chest pain; (2) angiographically significant single vessel disease (>50% stenosis); (3) no prior myocardial infarction. All patients underwent maximal exercise thallium single photon emissioncomputed tomography (T1-SPECT). Tl-SPECT was scored visually according to a 0 to 3 scale (0=absent uptake; 1=markedly decreased uptake; 2=minimally decreased uptake; 3=normal uptake). Translesional gradient and percent stenosis were measured before and after angioplasty. The authors found that significant linear ...
The design considerations and computational fluid dynamics (CFD) modeling of a high efficiency, low emissions, hydrogen-fueled engine for use as the prime mover of a series hybrid automobile is described. The series hybrid automobile uses the engine to generate electrical energy via a lightweight generator, the electrical energy is stored in a power peaking device (like a flywheel or ultracapacitor) and used as required to meet the tractive drive requirements (plus accessory loads) through an electrical motor. The engine/generator is stopped whenever the energy storage device is fully charged. Engine power output required was determined with a vehicle simulation code to be 15 to 20 kW steady state with peak output of 40 to 45 kW for hill climb. Combustion chamber and engine geometry were determined from a critical review of the hydrogen engine experiments in the literature combined with a simplified global engine model. Two different engine ...
This study was performed to evaluate the diagnostic usefulness of double-phase Tc-99m MIBI parathyroid scintigraphy with single photon emissioncomputed tomography (SPECT) in patients with hyperparathyroidism. We also evaluated the relationship between Tc-99m MIBI uptake and oxyphil cell contents in parathyroid glands. The subjects were 28 parathyroid glands of 10 patients who underwent Tc-99m MIBI parathyroid scintigraphy and parathyroidectomy for clinically suspected hyperparathyroidism. Early and delayed pinhole images were obtained at 15 minutes and 2 hours after injection of Tc-99m MIBI, and SPECT images were followed. The weight and oxyphil cell contents of parathyroid tissue were obtained from pathologic specimen, and the scintigraphic findings were compared with histopathology. In surgical histopathology, 6 parathyroid adenomas and 9 parathyroid hyperplasias were confirmed. The sensitivity, specificity, and positive predictive value of ...
Regional cerebral blood flow (rCBF) was assessed with single photon emissioncomputed tomography (SPECT), "1"2"3I-N-isopropyl-iodoamphetamine ("1"2"3I-IMP), and the Table-Look-Up method in 51 children (27 boys, 24 girls) considered neurologically normal and aged 1 month to 15 years (mean age, 4 years 1 month; standard deviation (SD) 3 years 11 months) divided into seven age groups. The rCBF was measured in cortical regions, the cerebellum, thalamus, and the head of the caudate nucleus. Curves for reference values and standard deviations were defined for each region. The rCBF rapidly increased until 2 years of age, reaching maximum values during the third to fifth periods (2 to 10 years of age) in each region. The rCBFs then decreased, reaching adult levels at 10 to 15 years of age. The rCBF reached maximum values later in the frontal region than in other regions. The rCBF during the early period increased most prominently in the occipital ...
Residual radioactive material guidelines for uranium in soil were derived for the Colonie site located in Colonie, New York. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the U.S. Department of Energy (DOE). The site became contaminated with radioactive material as a result of operations conducted by National Lead (NL) Industries from 1958 to 1984; these activities included brass foundry operations, electroplating of metal products, machining of various components using depleted uranium, and limited work with small amounts of enriched uranium and thorium. The Colonie site comprises the former NL Industries property, now designated the Colonie Interim Storage Site (CISS), and 56 vicinity properties contaminated by fallout from airborne emissions; 53 of the vicinity properties were previously remediated between 1984 and 1988. In 1984, DOE accepted ownership of the CISS property from NL ...
Recent advances in self-amplified spontaneous emission (SASE) experiments stimulate interest in quantitative comparison of measurements with theory. In this paper we show that the widely used simulation code TDA3D, developed by Tran and Wurtele [Comput. Phys. Commun. 54, 263 (1989)] even though a single frequency code, can be used to determine the output power in the SASE process with excellent approximation in the exponential growth regime. The method applies when the gain is not very high, which is a special advantage, because when the gain is not very high, the analytical calculation is particularly difficult since the exponential growing term does not dominate. The analysis utilizes a scaling relation between the output power and the number of simulation particles in the code TDA3D: left-angle P right-angle=N_#lambda#"'/N_#lambda# left-angle P"'right-angle, where left-angle P right-angle is the output power and N_#lambda# is the line ...
The effect of anode length and operating gas pressure on the x-ray emission from a nitrogen-filling modified plasma focus device has been investigated. The time-resolved investigation of x ray was carried out by using a five-channel photodiode x-ray spectrometer. The maximum x-ray yield is seen to increase with the increase in the anode length from 110 to 125 mm. Further increase in the anode length to 130 mm causes the x-ray yields to decrease. The highest x-ray yield of 4.5 J into 4#pi# sr was found for 125 mm anode length, which is 0.2% of the input energy. The average x-ray photon energy was estimated by using half-value thickness method and found to be 8.4 keV. The electron temperature of the plasma was estimated to be around 3 keV by x-ray intensity ratio method. The space-resolved x-ray-emitting zones for all the anodes were captured by a pinhole-based x-ray imaging camera and the images were scanned for different gray levels by using a MATLAB ...
Medical imaging using single gamma-ray-emitting radionuclides typically makes use of parallel hole collimators or pinholes in order to achieve good spatial resolution. However, a tradeoff in sensitivity is inherent in the use of a collimator, and modern preclinical single photon emissioncomputed tomography (SPECT) systems detect a very small fraction of emitted gamma rays, often less than 0.1%. A system for small animal SPECT imaging which uses no collimators could potentially achieve very high sensitivity-several tens of percent-with reasonably sized detectors. This would allow two significant improvements in preclinical studies: images could be obtained more rapidly, allowing higher throughput for screening applications, or for dynamic processes to be observed with very good time resolution; and images could be obtained with less radioactive tracer, making possible the in vivo imaging of low-capacity receptor systems, aiding research into ...
Quantum computers hold the promise of solving certain computational tasks much more efficiently than classical computers. We review recent experimental advances towards a quantum computer with trapped ions. In particular, various implementations of qubits, quantum gates and some key experiments are discussed. Furthermore, we review some implementations of quantum algorithms such as a deterministic teleportation of quantum information and an error correction scheme.
Over the past two decades, quantum computing has become a popular and promising approach to trying to solve computationally difficult problems. Missing in many descriptions of quantum computing is just how probability enters into the process. Here, we discuss some simple examples of how uncertainty and probability enter, and how this and the ideas of quantum computing challenge our interpretations of quantum mechanics. It is found that this uncertainty can lead to intrinsic decoherence, and this raises challenges for error correction. (viewpoint)
For Stage II of the European Dioxin Project the following objectives were set: - Amendment of existing emission data collected for most relevant emission sources in order to reduce uncertainties of emission estimates. Collecting first emission data from countries not yet performing dioxin emission measurement programs. Extending the inventory of dioxin emissions to ambient air produced in Stage I by a complementary study on emissions to land and water. Extending the regional scope of data collection to countries in Central Europe. The report of Stage II of the European Dioxin Project is presented in 3 Volumes. Volume 1 contains an overview on the background and approach of different activities carried out and on the results obtained. These results are put into a broader view regarding the dioxin reduction measures in Europe leading to ...
Research reported here reveals that the reduction of CO{sub 2} emissions into the atmosphere, is mainly dependent on the decrease of the use of fossil fuels, but also on the development of environment-friendly technology and greening of the environment. 2 refs.
An improved method of counting acoustic emission (AE) events from water-stressed stems of cedar (Thuja occidentalis L.) is presented. Amplified AEs are analyzed on a real time basis...Full Text Available
Measurements are reported of ultrasonic acoustic emissions (AEs) measured from sapwood samples of Thuja occidentalis L. and Tsuga canadensis (L.) Carr. during air dehydration....Full Text Available
An ASTER (advanced spaceborne thermal emission and reflection radiometer) is one of the image sensors. It is to be installed in an earth survey polar orbit platform satellite, EOS-AM1, which is to be launched in 1998, and it is going to start its operation. Data observed by the thermal infrared remote sensing of ASTER include the spectral emissivity, and the spectral emission reflectivity which is expressed by the function of temperature. It is required to overcome technical problems how to extract the spectral emissivity from the observed data. The spectral emissivity extracted from the remote sensing data by the MMD method, measured for samples collected in Cuprite area, Nevada, and/or measured at sampled points were compared to each other and discussed. The hemisphere spectral reflectivity, which is indirect spectral emissivity, agreed well with the direct ...
In order to investigate the effects ethanol-diesel blends and altitude on the performance and emissions of diesel engine, the comparative experiments were carried out on the bench of turbo-charged diesel...Full Text Available
A historical prospective mortality study was conducted on a cohort of 34 156 male members of a heavy construction equipment operators union with potential exposure to diesel exhaust emissions. This...Full Text Available
The Natural Gas Vehicle Challenge `92, organized by Argonne National Laboratory and sponsored by the US Department of Energy, the Energy, Mines, and Resources - Canada, the Society of Automotive Engineers, and many others, resulted in 20 varied approaches to the conversion of a gasoline-fueled, spark-ignited, internal combustion engine to dedicated natural gas use. Starting with a GMC Sierra 2500 pickup truck, donated by General Motors, teams of college and university student engineers strived to optimize Chevrolet V-8 engines operating on natural gas for improved emissions, fuel economy, performance, and advanced design features. This paper focuses on the results of the emission event, and compares engine mechanical configurations, engine management systems, catalyst configurations and locations, and approaches to fuel control and the relationship of these parameters to engine-out and tailpipe emissions of regulated ...
In VHTGR (Very High Temperature Gas-cooled Reactor), the radiation plays an important role in heat transfer through the cavity in RCCS (Reactor Cavity Cooling System). We performed the series of experiments to measure the emissivity using the infrared thermometer with wavelength range of 8#approx#14 #mu#m. As the first step, the transmittance of Zinc Selenide (ZnSe) window was measured to estimate the emissivity that can compensate the attenuation effect of window. The kind of gas with various concentrations in the cavity will be released during postulated accidents to the coolant type, so it is essential to estimate the effects of gas on the measurement of emissivity. In this manner we measured the emissivity with the air, the helium and the steam inside chamber. The results represent that the concentration of the air and the helium do not affect the emissivity significantly while ...
Spontaneous radiation by an atom in a Rydberg state is inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous radiation emission is observed to turn off abruptly at the cutoff frequency of the waveguidelike structure, and the natural lifetime is measured to increase by a factor of at least 20.
Simulations with a regional chemical transport model show that anthropogenic emissions of volatile organic compounds and nitrogen oxides (NOx = NO + NO2) lead to a dramatic diurnal...Full Text Available
Emissions of sulphur and nitrogen oxides are continuing to fall in Europe but rise in Asia, according to calculations based on individual countries' predictions of economic development. The upward trend is slower than in previous predictions. 2 refs., 2 figs., 2 tabs.
Proper assessment of the hypothesis which correlates polycyclic aromatic hydrocarbons (PAHs) with the unidentified infrared emission bands requires additional experimental laboratory data. In order to address this need, thermal infrared emission studies were performed on a subset of PAHs suggested to be of astrophysical importance. It was proposed that infrared emission from interstellar PAHs occurs following absorption of an ultraviolet photon. Since energy transfer to the ground electronic state can be rapid for a species in which intersystem crossing is negligible, the emission spectrum may be viewed as resulting from an equilibrium vibrational temperature (Leger and d'Hendecourt, 1987). This has been the basis for using infrared absorption spectra to calculate the corresponding emission spectra at various temperatures. These calculations were made using room temperature infrared ...
Air pollution abatement measures are not an end in themselves, and undesirable side effects should be taken into account. The proposed emission index takes into account the total emissions caused by a technical project as well as the effects of the individual pollutants.
The pharmacokinetic concepts of bioavailability and biotransformation are introduced into the assessment of public health risk from experimental data concerning the emissions of potentially mutagenic...Full Text Available
This study was undertaken to collect emissions performance data for Canadian and comparable American refineries. The objective was to examine parameters that affect refinery air emissions performance and develop methods or correlations to normalize emissions performance. Another objective was to correlate and compare the performance of Canadian refineries to comparable American refineries. For the purpose of this study, benchmarking involved the determination of levels of emission performance that are being achieved for generic groups of facilities. A total of 20 facilities were included in the benchmarking analysis, and 74 American refinery emission correlations were developed. The recommended benchmarks, and the application of those correlations for comparison between Canadian and American refinery performance, were discussed. The benchmarks were: sulfur oxides, nitrogen oxides, ...
A survey of various mechanisms for particle emission in hydrodynamics is presented. First, in the case of sudden freeze out, the problem of negative contributions in the Cooper-Frye formula and ways out are presented. Then the separate chemical and thermal freeze out scenario is described and the necessity of its inclusion in a hydrodynamical code is discussed. Finally, we show how to formulate continuous particle emission in hydrodynamics and discuss extensively its consistency with data. We point out in various cases that the interpretation of data is quite influenced by the choice of the particle emission mechanism.
The production of and emission factors for the air-polluting matters sulfur dioxide, nitrogen oxides, carbon monoxide, hydrocarbons (esp. benz(a)pyrene), aldehyde and soot with regard to natural gas, excluding process furnaces, are dealt with. The comparison with other fuels indicates that only as to nitrogen oxides and carbon monoxide are emission factors equal in order of magnitude. As a summary measure of all air-polluting matters the emission index as proposed already in 1972 is applied. It shows emissions with single-room furnaces for heating oil EL to be six times as high as with natural gas; with black-coal briquettes the factor is at least 33, with wood chimneys about 200.
The Federal Republic of German (FRG) had uniquely strict emission legislation for particulates SO_2 and NO_X from fossil-fired power plants. The 13th Regulation to the Federal Emission Control Act required that by 1 July 1988 all large furnaces fired with solid or liquid fuels that would not be decommissioned by 1993 be retrofitted with SO_2 control technology. The emission limits are 15 per cent of the sulphur introduced with the fuel (400 mg/m"3 maximum) at thermal capacities above 300 MW. 1 ref., 9 figs, 15 bibliographies.
The emission of light charged particles from heavy fragments of uranium fission induced by 153-MeV protons is studied. The probability of their emission is 2.7 x 10{sup - 2} per fission event. It is found that these particles affect the distribution of angles of fragment divergence and the angular distribution of heavy fragments with respect to the primary-proton beam. Experimental results suggest that the preequilibrium emission of particles is correlated with fission. Two mechanisms of interaction between 153-MeV protons and uranium nuclei are considered. 13 refs., 10 figs., 1 tab.
In this paper, the control scheme of a liquefied petroleum gas (LPG)-diesel dual-fuel engine with electronic control is illustrated, the external characteristics and load characteristics of the LPG-diesel dual-fuel engine and the diesel engine are compared and analysed, and the results of automobile road tests are also given. The experimental results show that, compared with diesel, the output performance of dual fuel is not reduced, while smoke emission of dual fuel is significantly reduced, NO{sub x} emission of dual fuel is hardly changed, but HC emission and CO emission of dual fuel are increased and fuel consumption of dual fuel is reduced. (Author)
In a new approach to medical computer based education (CBE) students at several U.S. and Canadian health professions schools have been using an optical videodisc under computer control to study basic...Full Text Available
This contribution is intended to introduce the principles of quantum computing to those who always wanted to know about quantum computing but never dared to ask. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
During the entire performance period, from 12 May 2003 through 31 December 2006, we have conducted theoretical and computational research on quantum control problems central to quantum computation. In particular we completed a thorough and rigorous analys...
Following a brief description of the SSC, the computing needs are discussed for both the accelerator design and the experimentation. The computing power required is considerably beyond that being used at present facilities, and parallel processing is expected to play an important role in supplying these needs.
With the advent of powerful, widely-available mathematical software, combined with ever-faster computer hardware, we are approaching a day when both the discovery and proof of mathematical facts can be done in a computer-assisted manner. his article presents several specific examples of this new paradigm in action.
... in this paper is aimed at developing a computer vision system that will be used to automatically grade rough hardwood lumber. The purpose of the computer vision system is to locate and identify grading def...
The effect of atmospheric radioactive emissions from United Kingdom nuclear installations on acid deposition is assessed. Nitrogen oxide and ozone production resulting from and associated with discharges of airborne radioactivity, comparison with conventional emissions, and the direct effects of radioactive emissions on trees, are all discussed. (UK).
One requirement of a thermophotovoltaic (TPV) radiator is to efficiently emit photons at high temperatures to TPV cells for conversion to electric power. Because many candidate radiator materials with adequate structural properties display low emissivity, coatings or other surface modifications are required for enhancement of emissivity. Six plasma sprayed coatings and one textured surface demonstrated adequate thermal stability and emittance values of 0.8 or greater. Promising attributes of modified surfaces are identified.
This article, with 25 references, reviews the soil sources and sinks of carbon dioxide, methane, and nitrous oxide. The mitigation of greenhouse gas releases is discussed covering reduction of carbon dioxide emissions by a change in land use, the use of alternative waste disposal methods such as composting or recycling to reduce methane emissions, and management of nitrogen fertiliser applications to reduce nitrous oxide emissions. (Author)
Designing efficient policies for curbing greenhouse gas (GHG) emissions is of particular interest for todays policy makers, in view of global climate change threats. This paper analyses the options Switzerland has for curbing its CO{sub 2} emissions. Using MARKAL and MARKAL-NACRO models, it investigates, in particular effects of national and international carbon taxes. (author) 3 figs., 1 tab., 6 refs.
The report summarizes the results of a dioxin/furan emissions test of a secondary copper recovery cupola furnace equipped with an afterburner for hydrocarbon emissions control and two baghouses for particulate emissions control. The cupola furnace is used...
Greenhouse gas emissions from international maritime transport are exempt from liabilities under the Kyoto Protocol. Research into quantifying these emissions is ongoing, and influences policy proposals to reduce emissions. This paper presents a cargo-based analysis of fuel consumption and greenhouse gas emissions from New Zealand's international maritime transport of goods. Maritime transport moves 99.5% (by mass) of New Zealand's internationally traded products. It is estimated that 73% of visiting vessels' activity can be directly attributed to the movement of goods in and out of New Zealand. A cargo-based methodology was used to estimate that the international maritime transport of New Zealand's imports and exports consumed 2.5 million tonnes (Mt; 2.6 billion litres) of fuel during the year 2007, which generated 7.7 Mt of carbon dioxide (CO_2) emissions. Double-counting of ...
The method of life-cycle assessment (LCA) has been applied to cars with different power trains. As an example, the results for greenhouse gas (GHG) emissions are presented. They show possibilities and limits for the reduction of these emissions in the transportation sector by means of advanced technology. (author) 2 figs., 4 refs.
The method for calculating emissions to air has been revised, which has led to adjustments. Because of this, emissions in 1999 cannot yet be compared with previous years. Emissions in 1990 - 1998 are being recalculated now using the new method and are expected to be ready during 2001. Emissions to air of carbon dioxide (CO_2) in Sweden was 56.58 million tonnes in 1999, not including emissions from biofuels and international bunkers. The major sources of CO_2 emissions are the combustion of fossil fuels and the use of fuels for mobile sources. Total emissions to air of sulphur dioxide (SO_2) and nitrogen oxides (NO_x, counted as NO_2) in Sweden was 66 000 and 263 000 tonnes respectively in 1999. International bunkers are not included. The major source of SO_2 emissions is combustion of fossil fuels. Road traffic is the ...
The Baldwin Effect, a negative correlation between emission-line equivalent width and luminosity in active galactic nuclei, is still of interest as a diagnostic of accretion physics nearly thirty years after its discovery. This review examines recent developments in the study of correlations between line and continuum emission in AGNs, as measured both in ensembles and in individual sources.
We discuss models of computing that are beyond classical. The primary motivation is to unearth the cause of nonclassical advantages in computation. Completeness results from computational complexity theory lead to the identification of very disparate problems, and offer a kaleidoscopic view into the realm of quantum enhancements in computation. Emphasis is placed on the `power of one qubit' model, and the boundary between quantum and classical correlations as delineated by quantum discord. A recent result by Eastin on the role of this boundary in the efficient classical simulation of quantum computation is discussed. Perceived drawbacks in the interpretation of quantum discord as a relevant certificate of quantum enhancements are addressed.
Computation and information processing are among the most fundamental notions in cognitive science. They are also among the most imprecisely discussed. Many cognitive scientists take it for granted that cognition involves computation, information processing, or both ? although others disagree vehemently. Yet different cognitive scientists use ?computation? and ?information processing? to mean different things, sometimes without realizing that they do. In addition, computation and information processing are surrounded by several myths; first and foremost, that they are the same thing. In this paper, we address this unsatisfactory state of affairs by presenting a general and theory-neutral account of computation and information processing. We also apply our framework by analyzing the relatio...
The role of computers has become increasingly important for oil and gas field research and operations support. Today, the computer network is an integral part of the increasingly complex computing environment that exists in many companies. Computer networks allow users to efficiently share information, software, and hardware to support critical global communication needs. Because users are able to share software and hardware, the use of computer networks can also result in significant cost savings. This paper describes typical network loading and demand levels for shared software applications on a computer network that has been used for several years.
A register transfer language is used to present the basic concepts of computer hardware architecture. Material needed for understanding computer organisation, design, and programming is included. The various functional units of digital computers (central processor, microprogram control; arithmetic algorithms; input-output; and memory organisation), are examined. A basic computer is developed to demonstrate the components of computer hardware and software architecture. Parallel processing and multiprocessor systems are discussed. Numerous MSI and LSI digital functions are introduced with explanations of their characteristics. Cache memory and the hardware requirements for a memory management unit are covered.
BackgroundThe WINPEPI computer programs for epidemiologists are designed for use in practice and research in the health field and as learning or teaching aids. The programs are free,...Full Text Available
The results of this research centered on the experimental studies of a single superconducting persistent current qubit, the implementation of type-II algorithms using these qubits, and the proposal for adiabatic quantum computing using these qubits. The m...
... exercises and biotechnology labs and didactic material. It includes sessions on computer and media ... computers, and learn how IPT activities and materials can help meet their curriculum objects ...
we have a colloquium scheduled. Computing: register your machine and check our network security and visitor computer policies. For Our Information: Once arranged, please let us...
We survey results in lattice quantum chromodynamics from groups in the USQCD Collaboration. The main focus is on physics, but many aspects of the discussion are aimed at an audience of computational physicists.
The general goals of this research effort is to explore the potential applications and performance of fine grained computer architectures for vision. The body of this report gives a brief overview of the results of the research during the first twelve mon...
Sep 1, 2011 ... 2005. Computer simulation modeling of recreation use: current status, case studies, and future directions. Gen. Tech. Rep. RMRS-GTR-143. ...
There is considerable interest in the use of silicon devices as qubits for quantum computing. The existence of nuclear spin in a silicon isotope and the complex band structure of silicon are unfavourable for this application of silicon devices. (viewpoint)
... Society Physics Press Release 05-175Korea Joins International Computing Infrastructure ... connectivity with Korea in a ceremony last month. Facilitated by the Korea Institute for Science and ...
Explore security settings for home equipment, learn how to browse safely and securely, and keep your computer up to date and secure. Explore different account ...
Over the past decade, dramatic increases in computational power and improvement in image analysis algorithms have allowed the development of powerful computer-assisted analytical approaches...Full Text Available
Speaking to thousands of attendees at Oracle's customer and partner conference, Chairman and CEO Larry Ellison launched Oracle's Grid Computing initiative (1/2 page).
The economics of medical computer networks are presented in context with the patient care and administrative goals of medical networks. Design alternatives and network topologies are discussed with...Full Text Available
A case of intrathoracic lipoma in a child is presented. The diagnosis was made before operation by means of computer-assisted tomography, a non-interventional procedure.
USGS scientists Ellyn Montgomery and William Danforth discuss incoming data in a computer lab on U.S. Coast Guard Cutter Healy. This was during a scientific expedition to map the Arctic seafloor....
Disclosed in this proposal are plans to construct a patent pending wrist module with computer control, configurable to form high-dexerity telerobotic arms ...
138 unselected head tomographies of children by computer are reported and analysed. The major aspect stressed by the authors is the excellent precision of this radiological technique.
High-throughput genomic and proteomic technologies have generated a wealth of publicly available data on ageing. Easy access to these data, and their computational analysis, is of great importance in...Full Text Available
He said, I had heard of Cloud Computing when I was in grad school, but they had presentations on it at EclipseCon. I was sold that it was something that ...
Many family physicians are considering purchasing a computer in the near future. This article explains some of the jargon of the computer industry and describes the various specifications that will...Full Text Available
Sep 1, 2011 ... Publication Information. Bookmark and Share. Title: Arc Habitat Suitability Index computer software. Author: Juntti, Thomas M.; Rumble, Mark A. ...
This report presents estimates of the annual anthropogenic UK emissions of greenhouse gases for the years 1990-93 for submission under the Framework Convention on Climate Change. The gases considered are carbon dioxide, methane, nitrous oxide, nitrogen oxides, carbon monoxide and non-methane volatile organic compounds. Emissions of all the gases have declined since 1990. In particular, those of carbon dioxide have fallen by 4%; those of methane by 8% and those of nitrous oxide by 28%. Emission estimates are reported in the IPCC Standard Tables format disaggregated by source category and fuel. The methodology used for the estimates and how they relate to the UK National Atmospheric Emissions Inventory is discussed in an appendix. (author)
The document presents an overview on atmospheric pollution in Lebanon, with an analysis of sources of pollution, their impact on local and global environment and their control.Local causes of pollution are mainly: -Thermal power plants of electric power production which produce 75% SO_2 emission and 60% dust - Industries, especially cement industry - Land transportation which produces 70% NOX emission and 50% CO_2 A description of air pollution caused by these three sectors is revealed. Pollutants derived from fuel combustion are analyzed. It is estimated that in 2010, Co_2 emission will reach 5204450 tons, SO_2 emission will be 136470 tons, NOX emissions 96870 and dust estimated to 4130 tons. CFC consumption and measures of control according to Montreal Protocol are described. Recommendations for control of air pollution in Lebanon within a national policy are presented.
The production of atmospheric pollutants in combustion processes depends on plant characteristic, combustion conditions and fuel quality. The influence of fuel quality on the emission of sulphur oxides, nitrogen oxides, carbon monoxide, dust and carbon dioxide and on the emission of some toxic pollutants, such as heavy metals and polycyclic aromatic hydrocarbons, is analysed. The comparison between the emission limits, fixed by the Italian legislation, and the uncontrolled pollutant emissions, produced by fossil fuel combustion in power plants and industrial use, shows that, in order to comply with the limits, a reduction of pollutant emissions is required through the use of abatement systems and cleaner fuels where natural gas has a primary role. The use of cleaner fuels is particularly required in heating plants and appliances for the residential sector, where the development of ...
This patent describes a low emission duel fuel engine system. It comprises: a dual fuel engine having a combustion chamber; a fuel oil supply connected to the engine; a fuel gas supply connected to the engine; and means connected between the fuel oil supply and the engine for injecting fuel oil into the engine. The means connected between the engine and fuel oil supply limiting the injection of fuel oil to the combustion chamber to pilot ignition quantities only, wherein the limiting means includes means for limiting the injection of fuel oil such that the exhaust emission of NO{sub x} is at an emission rate of less than 1 GM/PH-HR, whereby the exhaust emission performance of the dual fuel engine is enhanced.
The formaldehyde surface emission monitor (FSEM) has been developed for passive non-destructive measurement of formaldehyde (CH/sub 2/O) emission rates from CH/sub 2/O resin-containing materials. It is envisaged as a potential quality control and in-situ monitoring technique. For quality control applications to pressed-wood products, strong correlations between the results of the FSEM and environmentally controlled (small scale) chamber tests were observed. The FSEM is used to measure the cumulative CH/sub 2/O emission from a finite area of pressed-wood product during a fixed test period. The final result is reported as an average CH/sub 2/O emission rate (mg CH/sub 2/O/m/sup 2/h).
Investigations were conducted on the range of emission rates of NO, NO[sub 2], CO and hydrocarbons, and the thermal efficiencies produced by each burner on three production cookers, supplied by different Australian manufacturers. It was found that the emissions and efficiencies were markedly affected by (1) the thermal input, both with and without a load on the burner, and (2) the load-height to flame-length ratio, with a load on the burner. The effect of hydrocarbon leakage into the secondary/dilution air was investigated, to explain the observed correlation of hydrocarbon emission rate with dilution air flow. The hydrocarbons were found to arise from two sources: -leakage from the stabilisation ports at the base of the burner, which was found to be significant at the higher thermal input; -incomplete combustion of the fuel in the premix, which was the dominant source of hydrocarbons emissions at the ...
This report documents radionuclide air emission from the Hanford Site in 1997, and the resulting effective dose equivalent to the maximally exposed member of the public, referred to as the MEI. The report has been prepared in accordance with reporting requirements in the Code of Federal Regulations, Title 40, Protection of the Environment, Part 61, National Emissions Standards for Hazardous Air Pollutants, Subpart H, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities. This report has also been prepared in accordance with the reporting requirements of the Washington Administrative Code Chapter 246-247, Radiation Protection-Air Emissions. The effective dose equivalent to the MEI from the Hanford Site`s 1997 point source emissions was 1.2 E-03 mrem (1.2 E-05 mSv), which is well below the 40 CFR 61 ...
Using a sample of 30,000 quasars from SDSS-DR7, we explore the range of properties exhibited by high-ionization, broad emission lines, such as CIV 1549. Specifically we investigate the anti-correlation between L_UV and emission line EQW (the Baldwin Effect) and the "blueshifting" of high-ionization emission lines. The blueshift of the CIV emission line is nearly ubiquitous, with a mean shift of 810 km/s for radio-quiet (RQ) quasars and 360 km/s for radio-loud (RL) quasars, and the Baldwin Effect is present in both RQ and RL samples. Composite spectra are constructed as a function of CIV emission line properties in attempt to reveal empirical relationships between different line species and the SED. Within a two-component disk+wind model of the broad emission line region (BELR), where the wind filters the continuum seen by the disk component, we find that RL ...
Activities of the Referenzlaboratorium Reinhaltung der Luft at Magdeburg as well as existing air pollution standards in the German Democratic Republic are reviewed. The laboratroy coordinates research and standardization in the field of industrial air pollution for the Ministry of Health. The standards provide orientation for emission control by state district health inspectorates. Emission limits (in g/m/sup 3/) which are international standards for 15 selected industries are listed. Emission limits (in g/m/sup 3/) of GDR standards, issued between 1971 and 1984 are also provided. They concern emission of brown coal dust from coal preparation plants, dust and chemical compound emission from metallurgical plants, dust emission from plants of the limestone and cement industry as well as from cupola furnace plants, boiler plants, plants of the wood industry and ...
Magnetically driven non-stationary acceleration of jets in active galactic nuclei results in the leading parts of the flow being accelerated to much higher Lorentz factors than in the case of steady-state acceleration with the same parameters. The higher Doppler-boosted parts of the flow may dominate the high-energy emission of blazar jets. We suggest that highly variable GeV and TeV emission in blazars is produced by the faster moving leading edges of highly magnetized non-stationary ejection blobs, while the radio data trace the slower-moving bulk flow. Thus, the radio and gamma-ray emission regions have different, but correlated, Doppler factors. High-energy emission is generated, typically within the optically thick core, in the outer parts of the broad-line emission region, avoiding the radiative drag on the faster parts of the flow. The radio emission ...
This guide explained the requirements for Off-Road Compression Ignition Engine Emission Regulations established under the Canadian Environmental Protection Act. The regulations are enforced by Environment Canada, which authorizes and monitors the use of the national emissions mark. The regulations prescribe standards for off-road engines that operate as reciprocating, internal combustion engines, other than those that operate under characteristics similar to the Otto combustion cycle and that use a spark plug or other sparking device. The regulations apply to engines that are typically diesel-fuelled and found in construction, mining, farming and forestry machines such as tractors, excavators and log skidders. Four different types of persons are potentially affected by the regulations: Canadian engine manufacturers; distributors of Canadian engines or machines containing Canadian engines; importers of engines or machines for the purpose of ...
This guide explained the requirements for Off-Road Compression Ignition Engine Emission Regulations established under the Canadian Environmental Protection Act. The regulations are enforced by Environment Canada, which authorizes and monitors the use of the national emissions mark. The regulations prescribe standards for off-road engines that operate as reciprocating, internal combustion engines, other than those that operate under characteristics similar to the Otto combustion cycle and that use a spark plug or other sparking device. The regulations apply to engines that are typically diesel-fuelled and found in construction, mining, farming and forestry machines such as tractors, excavators and log skidders. Four different types of persons are potentially affected by the regulations: Canadian engine manufacturers; distributors of Canadian engines or machines containing Canadian engines; importers of engines or machines for the purpose of ...
This paper describes the development and a detailed analysis carried out on the luminescence characteristics of Pr"3"+ doped ZrF_4-BaF_2-LaF_3-YF_3-AlF_3-NaF glasses. In the present work our objectives are to elucidate the possible mechanisms that are responsible for NIR to red upconversion process and yellow to blue upconversion emission in terms of energy level schemes from the praseodymium containing fibre optical glass composition. We have studied their different physical and optical properties. Besides our investigation on the upconversion emission of these glasses, normal fluorescence studies have also been undertaken in explaining the mechanisms in demonstrating bright red and blue emissions upon excitations at visible and UV wavelengths. Besides these measurements works, a bright blue colour emission was observed under an UV source (202 nm) and upconverted prominent red ...
Measurements of ion-induced electron emission have been performed with helium and argon ions with energies between 300 and 900 eV on W, W with 10% Ti, Al, Al with 1% Cu, Al with 1% Si, Si, and Be. This article describes many of the important surface characteristics that influence the ion-induced electron emission. For low-energy ions, the substrate material was found to be less important as the velocity of the incident ion decreased. In the case of incident Ar"+ the substrate material had a negligible effect on the emission for this energy range. The presence of an adsorbed layer enhanced emission in all cases. Heating the substrates resulted in oxidation of the surfaces and a subsequent increase in emission. The electron emission from aluminum samples with smaller grain sizes was higher than samples of identical composition with larger grains. This effect is ...
With regard to polybrominated diphenyl ether (PBDE), there is few scientific knowledge on the emission patterns into the environment and exposure pathways to humans, and basic information is insufficient to consider what measures effective are. For the purpose of promoting risk reduction of target substances more effectively and efficiently, it is desirable to comprehend accurately the causal chain from the target substances utilization to the risk intake, and to evaluate the measures covering the whole applications of target substances. As the existing researches on the PBDE emission inventory, there are EU risk assessment report (European Chemical Bureau 2000, 2002, 2003), Danish EPA (1999), Palm et al.(2002) and Alcock et al. (2003). In addition, emissions of DecaBDE are published in TRI (Toxic Release Inventory) of US EPA. However, the primary information of the previous inventories is often the same and estimations ...
The increasing diffusion of small-scale energy systems within the distributed generation (DG) paradigm is raising the need for studying the environmental impact due to the different DG solutions in order to assess their sustainability. Addressing the environmental impact calls for building specific models for studying both local and global emissions. In this framework, the adoption of natural gas-fueled DG cogeneration technologies may provide, as a consequence of cogeneration enhanced overall energy efficiency and of natural gas relatively low carbon content, a significant reduction of global impact in terms of CO2 emissions with respect to the separate production of electricity and heat. However, a comprehensive evaluation of the DG alternatives should take into account as well the impact due to the presence of plants spread over the territory that could increase the local pollution, in particular due to CO and NOx, and thus could worsen the ...
This study tried to reduce NO{sub x} and particulate emissions simultaneously in a high speed direct-injection diesel engine. Fuel-rich combustion was used to reduce NO{sub x} emission at initial combustion stage and high turbulence combustion was used to reduce particulate emission at diffusion combustion stage. Experiments were carried out to investigate the effects of high squish combustion chambers with small throat on combustion process and exhaust emissions. Results showed that in the high squish combustion chamber, both NO{sub x} and particulate emissions reduced with retarded injection timing. Endoscopic high speed photography was employed to analyze experimental results. In the original combustion chamber at the early combustion stage, the high luminosity flame tended to spread out of the cavity. Fuel-rich mixture burned slowly over the piston crown. In the high squish ...
Heavy-duty trucks and buses are substantial contributors to the atmospheric oxides of nitrogen (NO_x) inventory, but prediction of their emissions in real use remains inchoate. Continuous emissions of NO_x were recorded from Chassis dynamometer testing of eight vehicles using a variety of transient cycles, including the Central Business District schedule. NO_x data were treated to account for sampling time lag and presented against instantaneous vehicle axle power. Data were repeatable from run to run and test schedule, but vehicle type and test cycle both influenced the instantaneous emissions rates. However, the resulting correlations may be used for mobile source NO_x contribution estimation when combined with vehicle activity data. The emissions data were also presented as NO_x/CO_2, which are valuable for comparison with remote sensing emissions data. The overall average ratio ...
Another difference lies in the speed of star evolution. 2. Computation of Stellar Structure and Their Evolution. The structure of stars at certain instants ...
In 15 children (in age 2 weeks - 15 years) the computer tomography beside radiological examination was done because of mediastinal diseases. In all cases the computer tomography was valuable. In 4 cases obtained results have changed diagnostic conclusions. The examples are described showing the usefulness of the computer tomography as supplementary diagnostic method in mediastinal diseases in children.
Inspired by the work of Feynman, Deutsch, We formally propose the theory of physical computability and accordingly, the physical complexity theory. To achieve this, a framework that can evaluate almost all forms of computation using various physical mechanisms is discussed. Here, we focus on using it to review the theory of Quantum Computation. As a preliminary study on more general problems, some examples of other physical mechanism are also given in this paper.
The basic objective of this project was to consider a large class of matrix computations with particular emphasis on algorithms that can be implemented on arrays of processors. In particular, methods useful for sparse matrix computations were investigated. These computations arise in a variety of applications such as the solution of partial differential equations by multigrid methods and in the fitting of geodetic data. Some of the methods developed have already found their use on some of the newly developed architectures.
... Note that the terminal ... Probability and Statistics with Reliability, Queueing, and Computer ... Weiss, G., "Stochastic Bounds on Distributions of Optimal ...
In a joint study conducted by the University Clinic of Radiology, Graz, and the Medical University Clinic, Innsbruck, the results of computer tomography examinations of the abdomen and pelvis in 23 cases of tumours in children are discussed. In children computer tomography resents special difficulties on account of the very poorly developed fatty layers between the organs and the increased incidence of movement artifacts. The importance of computer tomography for the diagnosis of abdominal and pelvic tumours is discussed.
A method for elucidating complex abnormalities of CSF circulation by using a positive contrast medium (metrizamide) and computer tomography is described. The technique for the method, the results and their clinical significance is demonstrated. The value of this method is compared with traditional ventriculography and with computer tomography without the use of contrast medium. It is shown that the technique represents an important extension of the scope of computer tomography.
Computed tomographic findings in developmental brain anomalies are more easily classified when the system used is based on embryogenesis related to morphology. Analysis of computed tomographic findings in a series of 154 patients with brain anomalies (Chiari malformation not included) revealed that specific examples of abnormalities occurring in major stages of brain development may be recognized by computed tomography. This paper deals with a group of patients with abnormalities that reflect a disturbance in neuronal migration. (orig.).
This book deals with advanced computing applications in physics, and in particular in high energy physics environments. The main subjects covered are networking; vector and parallel processing; and embedded systems. Also examined are topics such as operating systems, future computer architectures and commercial computer products. The book presents solutions that are foreseen as coping, in the future, with computing problems in experimental and theoretical High Energy Physics. In the experimental environment the large amounts of data to be processed offer special problems on-line as well as off-line. For on-line data reduction, embedded special purpose computers, which are often used for trigger applications are applied. For off-line processing, parallel computers such as emulator farms and the cosmic cube may be employed. The analysis of these topics is ...
Due to recent advancements in mobile computing and communication technologies, mobile ad hoc computational Grids are emerging as a new computing paradigm, enabling innovative applications through sharing of computing resources among mobile devices without any pre-existing network infrastructure. Energy-efficient resource allocation is one of the key issues in mobile ad hoc computational Grids due to limited battery life of mobile nodes. To reduce energy consumption, we propose a hybrid power-based resource allocation scheme for allocation of interdependent tasks to nodes within mobile ad hoc computational Grid. The basic idea is to exploit dependencies and task type, and allocate interdependent tasks to nodes accessible at minimum transmission power. We also propose a power-based algorithm...
Computers have a direct impact on our lives nowadays. Human's interaction with the computer has modified with the passage of time as improvement in technology occurred the better the human computer interaction became. Today we are facilitated by the operating system that has reduced all the complexity of hardware and we undergo our computation in a very convenient way irrespective of the process occurring at the hardware level. Though the human computer interaction has improved but it's not done yet. If we come to the future the computer's role in our lives would be a lot more rather our life would be of the artificial intelligence. In our future the biggest resource would be component of time and wasting time for a key board entry or a mouse input would be unbearable so the need would be of the computer interaction environment that along ...
Nuclear medicine and magnetic resonance imaging (MRI) are widely used in cardiac diagnostics. Both techniques have been carefully evaluated and are equivalent for the assessment of regional and global wall motion as well as the evaluation of ejection fraction and cardiac volumes, though MRI is herein currently seen as gold standard. For evaluation of myocardial perfusion, extensive data exist for nuclear imaging, that, next to high diagnostic accuracy for evaluation of coronary artery disease, show incremental prognostic information and allow for independent risk stratification. Because of rapid technical advance, myocardial perfusion imaging has also become feasible with cardiac MRI. Results of recent studies are promising, but the data are few compared to perfusion scintigraphy. For viability assessment in patients with ischemic cardiomyopathy, positron emission tomography (PET) with FDG is currently seen as gold standard. However, single photon ...
This paper deals with estimating aircraft landing and take-off (LTO) emissions (HC, CO, NO_x, SO_2) at 40 Turkish airports including the biggest airports, i.e. Ataturk International Airport (AIA) in Istanbul, Antalya Airport in Antalya and Esenboga Airport in Ankara in 2001. The calculation model is based on flight data recorded by the State Airports Authority. The flight data include the type and number of aircraft, number of passengers, amount of cargo etc., which depend on day-time and date. For the emission calculations the International Civil Aviation Organization (ICAO)-Engine emission data bank, which includes minimum and maximum values for both fuel flow rates and emissions factors, is used. By using first the minimum and then the maximum values from the data bank, two estimations of aircraft LTO emissions at Turkish airports are calculated: i.e. minimum and maximum ...
In order to consider some procedures to prevent errors in radiotherapy based in learned lessons of accidental expositions and in accordance with information contained in international reports elaborated by International Atomic Energy Agency (IAEA) and of the data base availability by the European group Radiation Oncology Safety Information System (ROSIS) on the events, a research of the occurred errors was performed. For the evaluation of the incidents a data base based in the ROSIS and added plus a parameter was created 'type of error'. All the stored data make possible the evaluation of the 839 incidents in terms of frequency of the type of error, the process of detention, the number of reached patients and the degree of severity. Of the 50 types of found errors, the type of error more frequently was 'incorrect treatment coordinate', confirmed with the data of literature and representing 28,96 por cent of the total of the incidents. The results ...
Reaction Engineering International (REI) has established a project team of experts to develop a technology for combustion systems which will minimize NO x emissions and minimize carbon in the fly ash. This much need technology will allow users to meet environmental compliance and produce a saleable by-product. This study is concerned with the NO x control technology of choice for pulverized coal fired boilers, ?in-furnace NO x control,? which includes: staged low-NO x burners, reburning, selective non-catalytic reduction (SNCR) and hybrid approaches (e.g., reburning with SNCR). The program has two primary objectives: 1) To improve the performance of ?in-furnace? NO x control processes. 2) To devise new, or improve existing, approaches for maximum ?in-furnace? NO x control and minimum unburned carbon. The program involves: 1) fundamental studies at laboratory- and bench-scale to define NO reduction mechanisms in flames and reburning jets; 2) laboratory experiments ...
Single photon emissioncomputed tomography (SPECT) of lung perfusions permits to map functioning lung parenchyma with higher sensitivity than CT. Delivering higher radiations doses it used to increase local control in lung carcinoma; this strategy is based on radiobiological and clinical studies. Lung parenchyma is a dose-limiting tissue in patients irradiated for lung cancer. Functional mapping based on SPECT and CT findings permits to design radiation beams such as to minimize irradiation of functioning lung. [Italian] L'integrazione delle immagini diagnostiche aventi diverso contenuto informativo anatomico-funzionale puo' essere utilizzata nella radioterapia per migliorare le procedure diagnostiche e ottimizzare la geometria dell'irraggiamento. I sistemi per l'elaborazione di piani di radioterapia oggi in uso sono direttamente interfacciati con gli apparecchi di Tomografia Computerizzata (TC) e ...
Aim: The purpose of this prospective study was to evaluate the value of immunoscintigraphy (ISG) with anti-225.28S in clinically suspected ocular melanoma. Methods: For this purpose standardized ISG was performed in 36 patients using both planar acquisition and emissioncomputed tomography (ECT). Ocular melanoma was present in 31 patients. In 21 patients therapy was enucleation of the eye. These specimens were evaluated by histology and immunohistochemistry in 11 of 21 patients. Results: Regarding the clinical diagnosis, ISG was positive only in 15 of 31 patients with ocular melanoma, regarding histology in 11 of 21 and regarding immunohistochemistry in 5 of 6 patients with a positive immunoreaction. 5 patients showed no immunoreactivity, their ISG was negative. Conclusion: Thus a good correlation between ISG and immunohistochemistry was observed. However ISG using the cutaneous melanoma antibody 225.28S cannot be recommended for the diagnostic ...
Waste management has gone through a history of shifting problems, demands, and strategies over the years. In contrast to the long prevailing view that the problem could be solved by hiding or moving it, waste is now viewed as a problem ranging from local to global concern, and as being an integral part of several sectors in society. Decisive for this view has been society's increasing complexity and thus the increasing complexity of waste, together with a general development of environmental consciousness, moving from local focus on point emission sources, to regional and global issues of more complex nature. This thesis is about the development and application ORWARE; a model for computer aided environmental systems analysis of municipal waste management. Its origin is the hypothesis that widened perspectives are needed in waste management decision-making to avoid severe sub-optimisation of environmental performance. With a strong ...
Nuclear physics parameters of the Wolsung CANDU-PHW reactor are computed by use of the PHWCELL computer code that is an improved version of LATREP. The PHWCELL code mainly computes cell parameters of heavy water moderated reactors, and modeling scheme of heavy water reactor cell calculations has been developed with the PHWCELL computer code. The reactor operating conditions considered in the study are cold zero power (CZP) and hot full power (HFP) with equilibrium poison. The cell parameters are also computed as a function of fuel burnup and the numerical results are compared with the results in PSR of the Wolsung unit and in the previous study. (author).
We present a numerical method for computing diffusive transport on a surface derived from image data. Our underlying discretization method uses a Cartesian grid embedded boundary method for computing the volume transport in region consisting of all points a small distance from the surface. We obtain a representation of this region from image data using a front propagation computation based on level set methods for solving the Hamilton-Jacobi and eikonal equations. We demonstrate that the method is second-order accurate in space and time, and is capable of computing solutions on complex surface geometries obtained from image data of cells.
The method, use and results of computer-aided diagnosis of bone tumours and tumour-like skeletal abnormalities in childhood are described. One hundred and twentyone histologically verified cases were analysed and subjected to computer-aided diagnosis. Statistical methods were used, resulting in an accuracy of 96.7% and 91.7% respectively. In order to obtain additional confirmation of the diagnosis, a so-called growth rate was calculated by the computer. This proved to be a reliable criterion for evaluating the biological behaviour of tumours, irrespective of the histological diagnosis. The reasons for misdiagnosis were discussed. Attention is drawn to the importance of an accurate analysis of the radiographs and its input into the computer.
This paper presents an approach to comparing computer run time of building simulation programs. The computing run time of a simulation program depends on several key factors, including the calculation algorithm and modeling capabilities of the program, the run period, the simulation time step, the complexity of the energy models, the run control settings, and the software and hardware configurations of the computer that is used to make the simulation runs. To demonstrate the approach, simulation runs are performed for several representative DOE-2.1E and EnergyPlus energy models. The computer run time of these energy models are then compared and analyzed.
This is the homepage of "an Australian multi-university collaboration undertaking research on the fundamental physics and technology of building, at the atomic level, a solid state quantum computer in silicon together with other high potential implementations." Although attempts to develop a quantum computer have met with limited success, the centre has substantial resources invested in advancing toward practical uses of quantum computing technology. The site provides a very good introduction to the principles and implications of quantum computing, as well as details about various research projects underway at the Australian universities. Links to conference and journal papers produced by members of the centre, many from 2003, are also provided.
...BUBL LINK: Computer programming - visual basic BUBL LINK Catalogue of Internet Resources Home | Search | Subject Menus | Countries ...O | P | Q | R | S | T | U | V | W | X | Y | Z Computer programming - visual basic Titles ... Author: Microsoft Subjects: computer programming - visual basic DeweyClass: 005.133 Resource type: software SearchVB....com Subjects: computer programming - visual basic DeweyClass: 005.133 Resource type: index VB Helper Tutorials ...
This Statistical Report presents results from the physical Swedish Environmental and Economic Accounts for the years 1993 and 1995 according to the classification NACE. The Environmental Economic Accounts constitute an integrated and comprehensive system for environmental and economic statistics. Environmental data are systematically presented together with economic data in a common framework. The system can be used for analyses of various relationships between economy and environment. Data on emissions to air of carbon dioxide, sulphur dioxide, nitrogen oxides, carbon monoxide, methane, nitrous oxide and ammonia are presented for 39 industries, government services and private consumption. The use of energy commodities in monetary and physical terms are also presented for the same sectors. Economic, energy and emission data are also presented in environmental and economic profiles and indicators. Environmental and economic profiles provide an ...
The optical properties of divalent europium activated Ca-#alpha#-SiAlON were investigated and the excitation and emission processes were discussed. The emission wavelength is influenced by the activator concentration of Eu more than the codopant concentration of Ca, in case of the same matrix composition of #alpha#-SiAlON. The red-shift of emission increases when the concentration of Eu increases. In addition, it was revealed that the red-shift of emission would be caused by the construction of the package of optical device. The correlated color temperature becomes low by the red-shift for the white light-emitting diode (LED) lamp using Ca-#alpha#-SiAlON:Eu phosphor when the phosphor powder concentration increases in the transparent resin which coats the primary light source of a blue LED die. The additional red-shift can be observed when the excessive amount of phosphor coating is intentionally poured ...
To aid in the study of lower hybrid current drive as a means of current profile control, the radial profile and velocity distribution of the fast current-carrying electrons and their time evolution must be known. As part of the recent effort to understand this fast electron transport, a diagnostic has been installed on PBX-M to measure the electron cyclotron emission from the fast electrons. An oblique horizontal view of upshifted cyclotron emission in the midplane can give radial as well as velocity space information about the fast electrons. Emission in X mode frequencies refracted by the right-hand cutoff is radially localized. The observed emission at a specific frequency comes only from the radial region r_t_u_r_n=#0. Emission measured by this new diagnostic has been found to be radially localized as predicted. It is also expected that localized moments of the distribution ...
This presentation gives the results of a research programme aimed at evaluating exhaust emissions from ships moving within confined coastal zones, as in Piraeus harbour. The level of various exhaust emissions were estimated on the basis of a mathematical model applied for each sea traffic element (ship). Hourly and daily records of all ships` movements in different parts of the harbour were compiled, covering extended periods of time and associated with different shipping operational characteristics (peaks, lows, etc). In order to correlate the exhaust emissions from shipping with the quality of the air in the area of interest, land-based measurements for the same pollutants were carried out in selected locations, near the port and in the greater Athens area. This enabled the investigation of time and spatial diffusion of exhaust emissions from shipping within the area of interest, taking into account ...
The report gives results of a project conducted to create a file containing comprehensive data on all electric utilities in the US. The National Acid Precipitation Assessment Program's (NAPAP's) emissions inventory activities focus on the estimation of emissions from pollutants that contribute to acid deposition. Electric utilities, which emit a large share of total acid deposition precursor emissions, are important for modeling analyses. Data reported by states to the National Emissions Data System (NEDS) for the 1985 NAPAP Emissions Inventory and data reported to the U.S. Department of Energy (DOE) on EIA Form 759, EIA Form 767, FERC Form 423, and the Integrated Data Base System (IDBS) were matched and combined. The resulting 1985 National Utility Reference File (NURF) contains detailed unit level data for nearly 10,000 electricity generating plants.
This report is an assessment of emission-control costs for municipal-waste combustors (MWCs). The details of the cost estimates, including their development, components, and cost premises, are addressed. A model-plant approach was used in the sizing and costing of the emission control systems. Due to differences in the feed-waste characteristics, combustion parameters, and emissions, separate cost estimates were required for mass burning (MB), modular (MOD), refuse-derived fuel (RDF), and fluid-bed combustion (FBC) type furnaces. Cost estimates were developed for control of particulate matter (PM) emissions only and for control of both acid gas and PM emissions from the MWC model plants. Controlled PM emission levels of 0.03, 0.02, and 0.01 gr/dscf, corrected to 12% CO/sub 2/, and 90 and 70% reductions of HC1 and SO2, respectively, were used to develop the ...
We present the results of a study on the 1.4 GHz kpc-scale radio emission in the complete flux density limited MOJAVE sample, comprising 135 radio-loud AGNs. While extended emission is detected in the majority of the sources, about 7% of the sources exhibit only radio core emission. Many BL Lacs exhibit extended radio power and kpc-scale morphology typical of powerful FRII jets, while a substantial number of quasars possess radio powers intermediate between FRIs and FRIIs. This poses challenges to the simple radio-loud unified scheme, which links BL Lacs to FRIs and quasars to FRIIs. We find a significant correlation between extended radio emission and pc-scale jet speeds: the more radio powerful sources possess faster jets. This indicates that the 1.4 GHz (or low frequency) radio emission is indeed related to jet kinetic power. Various properties such as extended radio power and ...
The exhaust emissions of a Diesel direct injection Perkins engine fueled with waste olive oil methyl ester were studied at several steady-state operating conditions. Emissions were characterized with neat biodiesel from used olive oil and conventional Diesel fuel. Results revealed that the use of biodiesel resulted in lower emissions of CO (up to 58.9%), CO{sub 2} (up to 8.6%, excepting a case which presented a 7.4% increase), NO (up to 37.5%), and SO{sub 2} (up to 57.7%), with increase in emissions of NO{sub 2} (up to 81%, excepting a case which presented a slight reduction). Biodiesel also presented a slight increase in brake-specific fuel consumption (lower than 8.5%) that may be tolerated due to the exhaust emission benefits. Combustion efficiency remained constant using either biodiesel or Diesel fuel. The proposed alternative for Diesel fuel could significantly decrease the ...
The document gives statistics on the pollutive emissions from Danish power plants during the period 1987-1996, the main pollutants being sulphur dioxide, nitrogen oxides and carbon dioxide. Data on efficiency levels relative to the production of electricity and heating and on the power plants` contribution to the total emission of CO{sub 2}, NO{sub x}, and SO{sub 2} from energy consumption in Denmark, are presented, and also as corrected for the net import of electricity. Other data on the emission of each of these chemicals by power plants are presented as factual, and corrected in accordance with the net import of electricity, and as factual per consumed and produced energy unit at the power plants. Short notes on related Danish legislation are found in addition to information on sources, methods and definitions used as a basis for the production of this document. Emission from power stations is ...
Historically, the bulk production of electricity has been achieved by burning fossil fuels, with unavoidable gaseous emissions, including large quantities of carbon dioxide: an average-sized modern coal-burning power station is responsible for more than 10 Mt of CO{sub 2} each year. This paper details typical emissions from present-day power stations and discusses the options for their reduction. Acknowledging that the cuts achieved in the past decade in the UK CO{sub 2} emissions have been achieved largely by fuel switching, the remaining possibilities offered by this method are discussed. Switching to less-polluting fossil fuels will achieve some measure of reduction, but the basic problem of CO{sub 2} emissions continues. Of the alternatives to fossil fuels, only nuclear power represents a zero-carbon large-scale energy source. Unfortunately, public concerns over safety and radioactive waste have ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO2) and sulfur dioxide (SO2) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO2 emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO2 emissions. Furthermore, the causality results show that ...
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to 1200 (constant 2000 prices) or to 3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the ...
We study the emission zone in a single-layer polymer light-emitting diode. The emission zone is found by studying the angular distribution of the electroluminescence. The emission is modeled by accounting for optical interference. We account for birefringence of the anode layer in our model. The active polymer was, however, found to be isotropic. The anode consists of a single-layer of the conducting polymer complex poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate) (PEDOT-PSS), with enhanced conductivity. As a cathode we use plain aluminum. By using only PEDOT-PSS we avoid having a thin metal layer or indium-tin-oxide as the anode in the path of the escaping light. The active material is a substituted polythiophene with excellent film forming properties. A comparison between the experimental and calculated angular distribution of light emission from a single-layered polymer light-emitting ...
A method was developed in which the potential of various measures is assessed systematically with a view to meeting the future EU5 emission specifications. Varied boundary conditions are taken into account, and their influence on the PM-NOx tradeoff was investigated. The relative cost is compared to an existing EU4 injection system. It was attempted to apply these measures to the impending US regulations (Tier2 Bin5) and to offer an outlook to EU6. The result shows that it is possible in principle for a car of the 1600 kg class to reduce NOx emissions while maintaining the EU4-PM emission standards.In the case of envisaged serial application subject to emission standards like US Tier 2 and EU6, much work is still required in terms of system robustness and life. In higher-class vehicles, the NOx reduction potential is lower, and it will be more difficult to make do without NOx treatment, especially with ...
Deregulation of the electric power industry in Alberta holds the prospect of providing greater choice for customers. One such option will be `green power` which is provided by renewable energy technologies. The energy produced would be without environmental impacts such as air emissions, water pollution, flooding, thermal emissions or waste by-products. Wind power, small scale hydro power, photovoltaics and biomass technologies have been termed as `green power`. The choices that customers make will not be focused on price alone. Market forces are emerging to demand reduction in emissions which will result in a market for `green energy` products and facilitate achieving goals for a sustainable future.
Divergence between aircraft engine emission regulations proposed by EPA and ICAO is discussed. Every engine, upon entering service, requires a certificate as to its compliance with emission standards. It is shown that despite the large variability in the measurements, it is possible to devise a certification procedure requiring the testing of one engine only. Statistical modeling of such a test at the 5% significance level is described. Values of the parameter standard deviation/mean recommended as certification standards for various pollutants are given. Features of a rational certification scheme to be formulated are outlined.
The problem of spectra formation in hydrodynamic approach to A+A collisions is discussed. It is analyzed in terms of the two different objects: distribution and emission functions. We show that though the process of particle liberation, described by the emission function, is, usually, continuous in time, the observable spectra can be also expressed by means of the Landau/Cooper-Frye prescription. We argue that such an approximate duality results from some symmetry properties that systems in A+A collisions reach to the end of hydrodynamic evolution and reduction of the collision rate at post hydrodynamic stage
An important aspect, which has to be considered in terms of municipal solid waste (MSW) management, is the stage of collection. The emissions generated from these systems can arrive to values that are of the same order of magnitude of emissions from combustion of waste in waste-to-energy plants. The present work faces the problem of transport, from intermediate station to the center of final combustion, placing attention to the emissions from scenarios that has been selected between real systems of management. This analysis can lead to highlight some important elements that can be useful to minimize the impacts.
The focus of this study is on the preparatory detection of uncertain net greenhouse gas (GHG) emission changes (also termed emission signals) under the Kyoto Protocol. The crucial question to be addressed is: How well do we need to know net emissions if we want to detect a specified emission signal after a given time? No restrictions exist as to what concerns the net emitter, which may be any GHG source or sink. Annex I countries are chosen as net emitters, simply for reasons of data availability and because of the excellent possibility of comparing net emitters (inter-country comparison). The countries' emissions - in an increasing number of cases even their uncertainties - are available permitting the application of preparatory signal detection techniques, which are suited to address the aforementioned question. We currently discuss four hierarchically-ordered detection ...
Hydrogen piston engines can be simultaneously optimized for improved thermal efficiency and for extremely low emissions. Using these engines in constant-speed, constant-load systems such as series hybrid-electric automobiles or home cogeneration systems can result in significantly improved energy efficiency. For the same electrical energy produced, the emissions from such engines can be comparable to those from natural gas-fired steam power plants. These hydrogen-fueled high-efficiency, low-emission (HELE) engines are a mechanical equivalent of hydrogen fuel cells. HELE engines could facilitate the transition to a hydrogen fuel cell economy using near-term technology.
A finite three-dimensional layer-by-layer photonic crystal with planar defects in a layer is shown to drastically modify the spontaneous emission rate of an embedded dipole. Finite-difference time-domain calculations with one quarter symmetric boundary condition and perfectly matched layer demonstrate the strong enhancement effects induced by the cavity resonance of defect modes and band-edge resonant modes. Simulation shows that the emission spectra are quite different when the position or polarization of the dipole is changed. Moreover, the extraction efficiency is calculated to observe the percentage of light leakage through a substrate.
Emission spectra obtained for three irradiated granular quartz samples under 1.43 eV excitation exhibited the 2.2 and 3.1 eV emission bands characteristic of feldspars. Excitation spectra of these same samples and several others show the 1.44 eV resonance typical of feldspars. This provides convincing evidence that the 2.2 and 3.1 eV infrared stimulated luminescence observed in these granular quartz samples arises from feldspar inclusions.
As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.
This paper presents an analysis of the performance of a selective emitter using small particles of rare earth compounds stable at high temperatures in a low emittance inert gas stream. An expression for the spectral emissive power excluding radiation scattering was derived to include the radiation in the emission band, produced by electronic transitions of the rare earth ion, and the continuum radiation outside the emission band produced by the rare earth host. Preliminary results suggest that a selective emitter based on suspended rare earth oxide particles will have high efficiency and merits further experimental investigation. {copyright} {ital 1996 American Institute of Physics.}
The possibilities of using both selective heavy ion induced X-ray emission and secondary ion mass spectroscopy (SIMS), for the identification of impurities present at low concentrations in cadmium telluride are examined. The relative concentrations of the impurities along CdTe crystals have been determined by exciting the X-ray emission of the elements in several slices with Ar and Kr ions and by comparing the relative characteristic X-ray emission yields. As a consequence of the quasimolecular inner shell ionization mechanism in heavy ion-atom collisions, Ar and Kr ions allow a strong excitation of the main impurities seen by SIMS namely Si, Cl and Ge, As, with only a minor contribution of Cd and Te. From the changes of the concentrations of the various impurities along the crystal, informations about segregation coefficients and compensation can be obtained.
The Toxicological Evaluation of Realistic Emissions of Source Aerosols (TERESA) study involved withdrawal, aging, and atmospheric transformation of emissions of three coal-fired power plants. Toxicological evaluations were carried out in rats exposed to different emission scenarios with extensive exposure characterization. Data generated had multiple levels of resolution: exposure, scenario, and constituent chemical composition. Here, we outline a multilayered approach to analyze the associations between exposure and health effects beginning with standard ANOVA models that treat exposure as a categorical variable. The model assessed differences in exposure effects across scenarios (by plant). To assess unadjusted associations between pollutant concentrations and health, univariate analyses...
The introduction of oxygen in the vicinity of a metallic target surface, bombarded with positive argon ions of twenty kiloelectron-volts, increases the number of sputtered atoms in the excited state. This phenomenon of exaltation, very sensitive in the case of nickel and aluminium, is much less marked in the case of molybdenum. Moreover, the emission of excited particles coming from the beam's ions is not modified. A quantum-mechanical model of a kinetic emission process, which permits the interpretation of the clean metallic target's emission phenomena, seems insufficient to explain all of the results obtained in the presence of oxygen. In this last case one can therfore use a thermodynamic model in which excited metallic particles can be formed directly by chemical surface reactions of neutralization or reduction. (orig.).
Gas separation membranes with polydimethylsiloxane(PDMS)/polystyrene(PS) were prepared by using the sequential interpenetrating polymer network (IPN) method with various PS contents (10?70wt%). These gas separation membranes can be applied to reduce the smoke density in the emission gas of diesel engines. PS content has a pronounced effect on the membrane performance. It was found that the optimized PS contents in the final membrane were 50wt%. The emission capacities of diesel engines used in this study were 632 cc and 11,149 cc. When the oxygen separation membrane was used in the diesel engines, the smoke density of both diesel engines was remarkably reduced (35?73%). The oxygen concentration in the inlet air affects the composition of the emission gases. Especially, hydrocarbon (HC) dec...
The purpose of this statement of work (SOW) is to establish laboratory analytical criteria and requirements for radioactive airborne emissions measurement sample and/or analysis activities.
Corrosion of steam generator heat transfer tubes (SGHTT) is one of the important problems which affect safety operation of nuclear power plants (NPP), and the hazard of pitting corrosion of heat transfer tubes is the most serious. With an acoustic emission device, the signals during a corrosion test on SGHTT were collected and analyzed, and the corrosion points in the tubes were located accurately. The results show that pitting corrosion of heat transfer tubes has passed through three periods in its development: expansion phase, stationary phase and rapid developing phase. The corrosion damage of HTT can be found earlier with acoustic emission than any other non-destructive testing methods. Acoustic emission can be used for on-line and real-time monitoring of the safety and operation of the steam generator and has therefore a great significance. (orig.)
Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including ...
Global climate policy initiatives are now being proposed to compensate tropical forest nations for reducing carbon emissions from deforestation and forest degradation (REDD). These proposals have the potential to include developing countries more actively in international greenhouse gas mitigation and to address a substantial share of the world's emissions which come from tropical deforestation. For such a policy to be viable it must have a credible benchmark against which emissions reduction can be calculated. This benchmark, sometimes termed a baseline or reference emissions scenario, can be based directly on historical emissions or can use historical emissions as input for business as usual projections. Here, we review existing data and methods that could be used to measure historical deforestation and forest degradation reference scenarios including FAO ...
This paper summarizes the main features of four current REDD proposals: Compensated Reduction, Papua New Guinea et al; Joint Research Center; and Brazil. ... ...
The influence of engine operating variables on the performance, emissions and heat release in a compression ignition engine operating in normal diesel and dual-fuel modes (with natural gas fuelling) was investigated. Substantial reductions in NO{sub x} emissions were obtained with dual-fuel engine operation. There was a corresponding increase in unburned hydrocarbon emissions as the substitution of natural gas was increased. Brake specific energy consumption decreased with natural gas substitution at high loads but increased at low loads. Experimental results at fixed pilot injection timing have also established the importance of intake manifold pressure and temperature in improving dual-fuel performance and emissions at part load. (Author)
The factors influencing premixed burning and the importance of premixed burning on the exhaust emissions from a small high-speed direct-injection diesel engine were investigated. The characteristics of premixed and diffusion burning were examined using a single-zone heat-release analysis. The mass of fuel burned in premixed combustion was found to be linearly related to the product of engine speed and ignition-delay time and to be essentially independent of the total amount of fuel injected. Accordingly, the premixed-burned fraction increased with increasing engine speed, with decreasing fuel-air ratio and with retarding injection timing. The hydrocarbon emissions did not correlate well with the premixed-burned fraction. In contrast, the oxides of nitrogen emissions were found to increase with decreasing premixed-burned fraction, indicating that diffusion burning, and not premixed burning, is the primary source of oxides of ...
NEWTON's first law prohibits the coupling of free tachyons to ordinary matter, if it is interpreted as selection rule interdicting emission without change of the rest-mass of the emitting system.
This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.
(e.g. enclosed cooktop with built in emissions capture and treatment) . " Test hardware in laboratory, reduced pressure and analog habitat. " Objective 1. ...
Divergence betyveen aircraft engine emission regulations pro- posed by EPA and ICAO is discussed Every engine, upon entering service, requires a certificate ...
We have studied the nature of continuum emitted in the visible spectral range from a noncontracted positive column of discharge in a cesium vapor-xenon mixture at a pressure of 45 Torr and at a degree of ionization below 3 ? 10?6. The main contribution to the continuous emission under such conditions is due to electron-xenon atom bremsstrahlung. The intensity of emission has been experimentally and theoretically studied as a function of the electric field strength and electron density in the positive column. It is established that an increase in the visible emission intensity with the electric field strength is related to an increase in the number of hot electrons in plasma.
This paper reports extensive new optical and radio observations of NGC 5728, emphasizing the central regions. Deep photographs revealing detail in the faint spiral arms are briefly discussed. Broad-band UBV CCD images obtained to examine the colors of the stellar populations that comprise the bar and central ring are presented. The velocity field and emission maps obtained from imaging spectroscopic measurements in the H-alpha emission line are discussed. Conventional long-slit spectra covering the ionized gas in the nuclear region are described. Detailed maps of the radio emission in the central regions of NGC 5728 are presented. These combined data provide considerable evidence for the inflow of gas into the nuclear region, in response to the nonaxisymmetric gravitational potential of the bar. The possible relation of this phenomenon to the Seyfert nature of NGC 5728 is also considered. 48 references.
We report novel, high-angular resolution interferometric measurements that imply the near-infrared nuclear emission in NGC 4151 is unexpectedly compact. We have observed the nucleus of NGC 4151 at 2.2 microns using the two 10-meter Keck telescopes as an interferometer and find a marginally resolved source ~0.1 pc in diameter. Our measurements rule out models in which a majority of the K band nuclear emission is produced on scales larger than this size. The interpretation of our measurement most consistent with other observations is that the emission mainly originates directly in the central accretion disk. This implies that AGN unification models invoking hot, optically thick dust may not be applicable to NGC 4151.
The performance of the gaseous fuel supply and its influence on hydrocarbon (HC) emissions of dual-fuel engines have been investigated. A new design of manifold respirators with mixers is also presented in the paper. The design of the gaseous fuel supply system has a great influence on HC emissions in the dual-fuel engine at light load. The problem of scavenging is discussed and solved by using the manifold respirators in the dual-fuel engine. It performs the function of retarding the gaseous fuel entry timing from the moment of intake valve opening, and its delaying effects have been measured and tested. Experimental results show that the manifold respirator gives the best performance in reducing HC emissions compared with a common pipe mixer and a respirator with bo miser. In addition, the mixing effects are sensitive to the mixer configuration. (Author)
Ceramic coatings with high emission were fabricated on Ti6Al4V alloy by microarc oxidation (MAO) with additive FeSO4 into the electrolyte. The microstructure, chemical composition and chemical state of the coatings were determined by SEM, XRD, EDS and XPS, respectively. The bonding strength between the coating and substrate was studied by tensile strength test, together with the thermal shock resistance of the coating. The results showed that Fe content in the coating layer significantly affect its thermal emissivity. The relative content of Fe in the coatings surface increased at first and then decreased with increasing the concentration of FeSO4 in electrolytes, so does the emissivity of the coatings. The bonding strength became weaker with increasing the concentration of FeSO4. In addit...
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis.This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of "hot air" which is significant to the implementation of the Kyoto Protocol. In addition, through the ...
... non- emissive guidance and collision alert, automated transport in dynamic environments, and assembly and inspection. Foveal Vision, Autonomous Agents, ...
Biomass combustion is an important part in a sustainable energy system, but as well a source of submicron (particles < 1 #mu#m) particles in the air. Consequently, to obtain a good air quality together with increased biomass combustion there is a need for a better understanding of particle formation. This work is a part of a larger project about formation and emissions of particles from biofuel combustion. The report includes the work performed in the project during the year 2004. The aim of the project is to describe the release of inorganic components, which cause particle emissions, during combustion of single fuel particles of biofuel, e.g. wood pellets. The work is carried out by emission measurements, systematic combustion experiments and modelling work. The results are expected to contribute to the understanding of which parameters that influence the formation of fine particles and thus gain a better insight into ...
The report contains general information on aluminium and aluminium compounds concerning the existing standards, emissions, exposure levels and effect levels. The document is to be considered as a first evaluation to be used for the national discussion dur...
The iron foundry industry is considered to be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated the emission factors and total emission amounts of PCDD/Fs and dioxin-like polychlorinated biphenyls (DL-PCBs) from iron foundries in China. The concentrations and the World Health Organization toxicity equivalents (WHO-TEQs) are presented and the congener profiles are discussed in this paper. In the present work, 26 fly ash samples were collected and tested to quantify the PCDD/Fs and DL-PCBs generated by 14 plants of different scales, and five stack gas samples were collected from two (named as EFG and LFG) of those plants. The emission levels of PCDD/Fs and DL-PCBs indicated that hot-air cupolas had lower emissions than cold-air cupol...
The paper discusses a number of recent studies investigating into the energy conservation and environmental impacts of electric heating systems (off-peak storage systems). In future, i.e. in and after 1993, off-peak storage systems will be evaluated through comparative analyses of oil-fired heating systems, pollutant emission analyses, the eventual success of pollution abatement measures designed for power plant emissions to keep within the legal limiting values, and the possible abandonment of pollution abatement measures abroad. Opposing the electric heating studies submitted by the electric power industry the author refutes their favourable results referring to the palliative selection of inadequate or vague parameters. Assuming average power plant pollutant emissions of 180 mg/standard/sup 3/ the nitrogen oxide emissions of oil-fired heating systems (134.1 kg/Tj) are found to be below those of ...
Before the 1997 Kyoto Protocol on Climate Protection, the fluorinated greenhouse gases HFCs, PFCs, and SF6 (F-gases) aroused little public attention. Since then, the standards on surveying and reporting on national emissions have been rising constantly. Amongst others, the annual reporting to the UNFCCC secretariat makes detailed declarations on use and emissions of F-gases necessary, which have to be filled in specified formats for submission (Common Reporting Format = CRF). The scientific basis has been set out by the UNFCCC guidelines on reporting, in accordance with the instructions laid down in IPCC good practice guidance. Additionally, in Germany the Centralised System of Emissions (ZSE) shall provide a suitable tool to satisfy any quality needs of both activity data and emission factors. From 1995 onwards, activity data and emissions of each individual application sector ...
Los Alamos National Laboratory (the Laboratory) is subject to emissions reporting requirements for regulated air contaminants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73 (20 NMAC 2.73), Notice of Intent and Emissions Inventory Requirements. The Laboratory has the potential to emit 100 tons per year of suspended particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, and volatile organic compounds. For 1998, combustion products from the industrial sources contributed the greatest amount of criteria air pollutants from the Laboratory. Research and development activities contributed the greatest amount of volatile organic compounds. Emissions of beryllium and aluminum were reported for activities permitted under 20 NMAC 2.72 Construction Permits.
Although various legislation and regulations have been adopted to promote the use of alternative-fuel vehicles for curbing urban air pollution problems, there is a lack of systematic comparisons of emission control cost-effectiveness among various alternative-fuel vehicle types. In this paper, life-cycle emission reductions and life-cycle costs were estimated for passenger cars fueled with methanol, ethanol, liquefied petroleum gas, compressed natural gas, and electricity. Vehicle emission estimates included both exhaust and evaporative emissions for air pollutants of hydrocarbon, carbon monoxide, nitrogen oxides, and air-toxic pollutants of benzene, formaldehyde, 1,3-butadiene, and acetaldehyde. Vehicle life-cycle cost estimates accounted for vehicle purchase prices, vehicle life, fuel costs, and vehicle maintenance costs. Emission control cost-effectiveness presented in dollars ...
The properties of negative-ion beams are very important for designing negative-ion apparatus and applications of negative-ion beams, especially, electron detachment cross-sections at the interaction between negative-ion beams and gas particles in the transport system, and secondary-electron emission factors when negative ions are incident on solid surfaces. These properties of negative-ion beams were investigated experimentally as a function of the ion energy under 50 keV. The single electron detachment cross-sections are almost constant in the other of 10[sup -15] cm[sup 2] in this energy range, but double electron detachment cross-sections increase in proportion to the ion velocity and much smaller than the single one. As for the secondary-electron emission factor, the emission factors for negative-ion beam are found to be larger by 1 than those for positive-ion beams. (author).
The properties of negative-ion beams are very important for designing negative-ion apparatus and applications of negative-ion beams, especially, electron detachment cross-sections at the interaction between negative-ion beams and gas particles in the transport system, and secondary-electron emission factors when negative ions are incident on solid surfaces. These properties of negative-ion beams were investigated experimentally as a function of the ion energy under 50 keV. The single electron detachment cross-sections are almost constant in the other of 10"-"1"5 cm"2 in this energy range, but double electron detachment cross-sections increase in proportion to the ion velocity and much smaller than the single one. As for the secondary-electron emission factor, the emission factors for negative-ion beam are found to be larger by 1 than those for positive-ion beams. (author).
Experiments have been conducted to study the effect of injection pressure on the combustion process and exhaust emissions of a direct injection diesel engine fueled with Orange Skin Powder Diesel Solution (OSPDS). Earlier investigation by the authors revealed that 30% OSPDS was optimum for better performance and emissions. In the present investigation the injection pressure was varied with 30% OSPDS and the combustion, performance and emissions characteristics were compared with those of diesel fuel. The different injection pressures studied were 215bar, 235bar and 255bar. The results showed that the cylinder pressure with 30% OSPDS at 235bar fuel injection pressure, was higher than that of diesel fuel as well as at other injection pressures. Similarly, the ignition delay was longer and wi...
This standard specifies requirements for the flameproofing and the limiting of surface temperature and exhaust emission control of diesel engine systems for use in underground coal mines.
... 1-sigma ZOHF pixel-to-plxel statistical fluctuations ... Spatial frequency filtering shows distinct bands, but miss ... LOS emissivity at the point of closest ...
Fire-driven deforestation is the major source of carbon emissions from Amazonia. Recent expansion of mechanized agriculture in forested regions of Amazonia ...
on the range of available deforestation, forest degradation, ... Results: Deforestation estimates showed good agreement for multi-year trends of increasing ...
A computer was built for use with the NRU reactor to solve the problem of Xe/sup 135/ concentrations. The effect of any changes in reactor on Xe/sup 135/ concentration can be predicted and steps taken to avoid poisoning out. An electromechanical system was used for the computer to avoid the inherent disadvantages that electronic analog computers present for problems of very long solution times. The electromechanical analog computer has a high order of reliability and contains no vaccum tubes, commutators, slip rings, relays, or aluminum electrolytic capacitors. It is insensitive to transient disturbarce. In the event of failure of components or interruption of line voltage, it will retain existing information. The computer was designed for ~ 1% accuracy in Xe/ sup 135/ concentration readings. (W.D.M.)
This paper reports on a study to validate the Graphical Network Representation (GRPHREP) model which is being conducted on the Los Alamos National Laboratory Integrated Computer Network (ICN). The GRPHREP model is a software system application based on graph theory and object-oriented programming methodologies. It codified the Department of Energy (DOE) Order 5637.1, which is concerned with classified computer secret policy, restrictions, and requirements. The Los Alamos ICN is required to control access to and support large-scale scientific and administrative computing. Thus, large-scale scientific and administrative computing. Thus we felt that this large, complex, and dynamic network would provide a good test for the graphical and functional capabilities of the model. Furthermore, the ICN is composed of multiple partitions that reflect the sensitivity and classification of the ...
This study examines the effects of intravenous infusion of adenosine and sublingual nitroglycerin on coronary angiograms obtained by current-generation multidetector computed tomography. We assessed...Full Text Available
Discussed in this report is a wavefield simulation in the 3-dimensional seismic survey. With the level of the object of exploration growing deeper and the object more complicated in structure, the survey method is now turning 3-dimensional. There are several modelling methods for numerical calculation of 3-dimensional wavefields, such as the difference method, pseudospectral method, and the like, all of which demand an exorbitantly large memory and long calculation time, and are costly. Such methods have of late become feasible, however, thanks to the advent of the parallel computer. As compared with the difference method, the pseudospectral method requires a smaller computer memory and shorter computation time, and is more flexible in accepting models. It outputs the result in fullwave just like the difference method, and does not cause wavefield numerical variance. As the computation platform, the ...
...challenges faced by the industrial sector by implementing a Research Agenda for Embedded Computing Systems. The Artemis JU will manage and co-ordinate open ...5 billion research programme on Embedded Computing Systems. The programme is open to organisations within the EU Member States as well as Associated ...
Science and technology could be revolutionized by quantum computers, but building them from solid-state devices will not be easy. Robert W Keyes of IBM's research division outlines the challenges in scaling up the technology from lab experiments to practical devices. (U.K.)
Background and objectives: Management of incidental renal artery and kidney abnormalities in patients undergoing computed tomography scans is a clinical challenge because their frequency in healthy...Full Text Available
Aug 8, 2011 ... Panel > Cloudenomics 101 What Cloud Computing Really Means for NASA. 11:00 am in Collaboration, LiveCall by Lucas Cioffi (Moderator) ...
Feb 24, 2000 ... NASA computer experts have been using a supercomputer to improve the NASA/ DeBakey miniature heart assist pump, leading to on-going human ...
Motivation: The identification of gene regulatory modules is an important yet challenging problem in computational biology. While many computational methods have been proposed to identify...Full Text Available
We successfully reproduce one of the French pipe whip experiments with the computer code WIPS. The WIPS results are in excellent agreement with the experimental data and the French computer code TEDEL. This justifies the use of its pipe element in conjunction with its U-bar element in a simplified method of impact analyses.
The percentages of total airflows over the nasal respiratory and olfactory epithelium of female rabbits were calculated from computational fluid dynamics (CFD) simulations of steady-state inhalation....Full Text Available
This is a description of the preliminary local design specifications of the Central Computing Network Security Controller. The external interface to the Central Computing Network is not described, but the functions and services to be provided are included as justification for the local design.
User acceptance of a computer system depends on a number of factors, including broad social and professional concerns regarding the system's impact on the work environment. This observation is especially...Full Text Available
Cyber attacks on a hospital's computer network is a new crime to be reckoned with. Should your hospital consider internet insurance? The author explains this new phenomenon and presents a risk assessment for determining network vulnerabilities. PMID:11951384
OBJECTIVE--To review findings from studies of the influence of desktop computers on primary care consultations. DESIGN--Systematic review of world reports from 1984 to 1994. SETTING--The computerised...Full Text Available
Experience has shown that a list of tips provides designers and engineers with an effective guide in their areas of duties and concern. This list contains new and rare information on heat exchangers and heat recovery systems. The information presented can be used effectively with personal computers and pocket calculators and also conveniently translated into computer programs and nomographs.
PURPOSE We wanted to assess computer capabilities in a primary care practice-based research network and to understand how receptive the practices were to new ideas for automation of practice...Full Text Available
A quantum computer (QC) can operate in parallel on all its possible inputs at once, but the amount of information that can be extracted from the result is limited by the phenomenon of wave function...Full Text Available
AbstractThe present study aimed to compare the whole-cell protein profiles of Haemophilus parasuis field isolates by using a computer-based analysis, and evaluate the...Full Text Available
In the study three loss-of-feedwater type experiments which were preformed with the PACTEL facility has been calculated with two computer codes. The purpose of the experiments was to gain information about the behaviour of horizontal steam generator in a ...
For over 20 years advocates of computer assisted instruction (CAI) have been proclaiming impending revolutionary developments in the educational process, yet progress in acceptance has been slow. This...Full Text Available
ObjectiveThis study was conducted to evaluate a computer-imaging program called HAAIR (Help with Adjustment to Alopecia by Image Recovery) that was developed to provide...Full Text Available
'Within 15 years the energy consumption bottleneck has shifted from the supply side to emissions, i.e. to the waste side.' Reflecting this statement one may realize the importance of lending more weight to energy conservation but may also be induced to critically analyze the corresponding measures. First results of such reflections are given with regard to the payback periods of air pollution abatement measures relative to the additional emissions they cause. (orig.).
Lectures were held on forest and wood management, the forest as an energy source and the emission problem of wood combustion, future emission limitating regulations for wood firing, influence of firing technique on air pollution abatement and constructive and operational air pollution abatement measures with manually and continuously fuelled furnaces.
The emission of Cerenkov radiation by tachyons has been examined by using the reduced expansions of superluminal electromagnetic fields in terms of standard helicity representation of Poincare group. It has been shown that the tachyons emit Cerenkov radiation through their coupling only with subluminal electromagnetic fields and that a charged tachyon can emit Cerenkov radiation only in the media in which it travels with a velocity lower than that of light while in the usual medium in which its velocity is more than that of light, it will never emit Cerenkov radiation.
In this work, the principal continuum radiative emission processes, which occur during the penetration of ions in solids or gases, are resumed. The characteristics of the following processes are discussed: secondary electron bremsstrahlung (SEB), atomic bremsstrahlung (AB), and internuclear bremsstrahlung (INB). Recent advances of the ion channeling effects in crystal solids on the spontaneous radiative spectra are exposed. (A.C.A.S.).
In February 2001, the Minister of Environment Canada outlined a series of measures to be implemented over the next decades to reduce emissions from vehicles, engines and fuels. The agenda includes the development of new regulations under the authority of Part 7, Division 5 of the Canadian Environmental Protection Act (CEPA) to align Canada's emission standards for on-road vehicles with those of the United States Environmental Protection Agency. This paper presents a detailed summary of comments received by the interested parties that appeared at a public consultation in November 2001 to discuss and raise issues about the proposed regulations. The parties that provided submissions included: governments; the vehicle and engine manufacturing industry; the oil industry; other groups of associations such as the Canadian Trucking Alliance, David Suzuki Foundation, and West Coast Environmental Law; and, five private individuals. The report ...
In response to a need of the safeguards community, we have begun an evaluation effort to upgrade the recommended values of the prompt neutron emission multiplicity distribution, P/sub nu/ and its average value, nubar. This paper will report on progress achieved thus far. The evaluation of the uranium, plutonium, americium and curium nuclide's nubar values will be presented. The recommended values will be given and discussed. 61 references.
It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.
The present work reports an experimental study on the behavior of a jet flame surrounded by a shroud of combustion air. Measurements focussed on the flame length and the emissions of NO{sub x}, total unburned hydrocarbons, CO{sub 2}, and O{sub 2}. Four different fuel flow rates (40.0, 78.33, 138.33, and 166.6 cm/s), air flow rates up to 2500 cm{sup 3}/s and four different air injector diameters (0.079 cm, 0. 158 cm, 0.237 cm, and 0.316 cm) were used. The shroud of combustion air causes the flame length to decrease by a factor proportional to 1/[p{sub a}/p{sub f} + C{sub 2}({mu}{sub a}Re,a/{mu}{sub f}Re,f){sup 2}]{sup {1/2}}. A substantial shortening of the flame length occurred by increasing the air injection velocity keeping fuel rate fixed or conversely by lowering the fuel flow rate keeping air flow rate constant. NO{sub x} emissions ranging from 5 ppm to 64 ppm were observed and the emission of NO{sub x} decreased ...
The Clean Air Act establishes New Source Review (NSR) programs that apply to the construction or modification of major stationary emissions sources. In 2002 and 2003, the U.S. Environmental Protection Agency revised its rules to narrow the applicability of NSR to facility renovations. Congress then mandated a National Research Council study of the effects of the rules. An electricity-sector model - the Integrated Planning Model (IPM) - was used to explore the possible effects of the equipment replacement provision (ERP), the principal NSR change that was to affect the power-generation industry. The studies focused in particular on coal-fired electricity generating units, EGUs, for two reasons. First, coal-fired EGUs are important contributors of these pollutants, accounting for approximately 70 and 20% of nations SO{sub 2} and NOx emissions in 2004, respectively. Second, the shares of total capacity of large coal-fired EGUs that lack flue-gas ...
Auger-electron emission from different silicides has been studied for 4 and 10 keV Ar ion excitation. The intensity of the SiLMM Auger line changes significantly with channing concentration and atomic number of the metal-parthner. The experimental results can be explained in terms of a simple model based on the probability of Si-Si collision symmetric cascade in these binary compounds.
In this report statistical data are presented on a national level on emissions to air in Sweden in 1995 of sulphur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}, counted as NO{sub 2}) and carbon dioxide (CO{sub 2}). Corresponding data for 1980 and 1994 are presented as a comparison. For CO{sub 2} data for 1990 and 1994 are presented as a comparison. The total amount of SO{sub 2}-emissions to air in 1995 were 94 000 tons, which means a decrease by 3 percent since 1994. The total amount of NO{sub x}-emissions to air were 362 000 tons, a 3 percent decrease since 1993. The total amount of CO{sub 2}-emissions to air were 63 200 000 tons, an increase by 7 percent compared with 1990. Differentiated data are given for various sources of emissions, i.e. combustion of fuels, industrial processes and mobile sources. Further data are presented on emission of SO{sub 2} and ...
Experiments have been conducted to study the effect of injection pressure on the combustion process and exhaust emissions of a direct injection diesel engine fueled with Orange Skin Powder Diesel Solution (OSPDS). Earlier investigation by the authors revealed that 30% OSPDS was optimum for better performance and emissions. In the present investigation the injection pressure was varied with 30% OSPDS and the combustion, performance and emissions characteristics were compared with those of diesel fuel. The different injection pressures studied were 215 bar, 235 bar and 255 bar. The results showed that the cylinder pressure with 30% OSPDS at 235 bar fuel injection pressure, was higher than that of diesel fuel as well as at other injection pressures. Similarly, the ignition delay was longer and with shorter combustion duration with 30% OSPDS at 235 bar injection pressure. The brake thermal efficiency was better at 235 bar than ...
Due to the 'novel forest diseases' the political parties of the Federal Republic of Germany unanimously attend to the reduction of emissions. The transportation sector is considered to be a major emission source. A study discussed in the publication abstracted did therefore aim at giving a detailed account and description of the recently ratified technical requirements and tax credits expected to reduce vehicle exhaust gas air pollution. Moreover, the study researches into the regulations' importance as to the low emission properties of individual automobiles. Based on the results obtained the study arrives at assumptions as to emissions to be expected from the transportation sector. It tries to assess the financial import with respect to the individual citizen, overall internal revenues and federal motor vehicle taxes. The introductory chapter is followed by a review of ...
A large IMF- and event characterizing multidetector system (CHICSI) is under development for storage ring experiments. In ''test'' experiments with telescopes of CHICSI type the IMF production has been measured for "1"4N induced reactions at 14A and 32A MeV. Detailed information about the emission sources, particularly from the IMF yield in reactions with isotope separated targets and from isobaric yield ratios in the sub-Coulomb region is discussed. (orig.).
This study presents and applies a coherent methodological framework to compare biomass cascading chains, i.e. the subsequent use of biomass for materials, recycling and energy recovery, considering land use, CO2 emission reduction and economic performance. Example cascading chains of short rotation poplar wood are compared with each other on the basis of literature data. Results for these chains vary strongly, namely, from CO2 mitigation benefits of 200 euro/Mg CO2 to CO2 mitigation costs of 2200 euro/Mg CO2, and from net CO2 emission reductions per hectare of biomass production of 28 Mg CO2/(ha yr) to net CO2 emissions of 8 Mg CO2/(ha yr). Using a present-value approach to determine CO2 emissions and costs affects the performance of long-term cascading chains significantly, i.e. cost and CO2 emission reduction are decreased. In general, cascading has the potential to improve both ...
This paper describes New York State Electric and Gas Corporation`s concept for a comprehensive, centrally located data system for management of their continuous emission monitoring systems (CEMS) data. The topics of the paper include the power system`s mix of generating units; data reporting requirements; data base management; nitrogen oxides compliance tracking; sulfur dioxide, nitrogen oxides, carbon dioxide and flow monitoring; and allowance tracking.
Characterization and optimization of electron-beam parameters are important aspects of optimizing free-electron laser (FEL) performance. The visible spontaneous emission ({lambda}{approximately}650 nm) from the 5-meter long undulator of the Boeing FEL experiment can be characterized in sufficient detail with a streak/spectrometer to deduce time-resolved electron-beam spatial position and profile, micropulse duration, and energy. 7 refs., 13 figs., 2 tabs.
Discussion is presented of world CO{sub 2} emissions and the effect rising population and population distribution has on this. Possible ways of decreasing emissions are presented, including potential for heat recovery, exhaust-air purification as an energy supply, shared power supply in industry, the use of cogeneration, and multiple use of heat in industry. 9 refs., 10 figs., 3 tabs.
We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.
In the last issue of 'L'Industrie ceramique et verriere', we presented the first part of this study. We describe in this issue the experimental procedure, the results and the conclusions of this work. (authors)
The paper investigates the controversial relation between the continuum luminosity and the C IV 1550 emission-line strength in the spectra of quasars, commonly referred to as the Baldwin effect, as a possible indicator of absolute luminosity. It is concluded that the Baldwin effect does represent a physical correlation between the continuum and the C IV 1550 equivalent width rather than a consequence of selection effects. In addition to the C IV results, a similar relation is found for the Lyman-alpha emission line. 38 refs.
This paper reviews three key initiatives undertaken in the historical city of Oxford to bring about reductions in energy-related CO_2 emissions on a city-wide scale. The author has been part of all the three initiatives. In 2002, a collaborative partnership between academia, industry and city council started the Oxford Solar Initiative (OSI) which uses a community-based approach to help households and organisations in Oxford, financially and technically, to install solar energy systems and energy efficiency measures in buildings. So far OSI has facilitated the installation of 80 active solar systems, over 450 energy efficiency measures and 3,000 low energy bulbs. The scientific basis of OSI is a GIS-based DECoRuM model which estimates and maps baseline energy use and CO_2 emissions on a house-by house level, identifies 'pollution' hotspots, predicts the potential for reductions in CO_2 emissions and monitors reductions ...
The authors present design methodology and initial experimental results for a high power microwave switch. The switch is designed for application to the pulse compression system associated with the Next Linear Collider Test Accelerator (NLCTA). The switch is based on the excitation of a plasma layer within a silicon wafer by either a laser or an electron beam. They investigate problems associated with high power operation of such a switch. They explore solutions to the problems of thermal runaway, avalanche breakdown, photo-emission, and secondary emission.
This critical review with 28 references examines absorption and emission in the v2 band of the carbon dioxide molecule at around the 15micron wavelength. The argument for additional infrared absorption, the enhanced greenhouse effect due to increased carbon dioxide concentrations, and radiation transport and increased emissions are discussed. Experiments studying the transmission spectra of pure carbon dioxide and carbon dioxide in nitrogen, and comparing them with the results of climate modelling using the HITRAN and GEISA databases, are described.
A standing challenge for the science of mind is to account for the datum that every mind faces in the most immediate - that is, unmediated - fashion: its phenomenal experience. The complementary tasks of explaining what it means for a system to give rise to experience and what constitutes the content of experience (qualia) in computational terms are particularly challenging, given the multiple realizability of computation. In this paper, we identify a set of conditions that a computational theory must satisfy for it to constitute not just a sufficient but a necessary, and therefore naturalistic and intrinsic, explanation of qualia. We show that a common assumption behind many neurocomputational theories of the mind, according to which mind states can be formalized solely in terms of instan...
sharing data and computational resources, and accessing information in digital libraries." Bill Wulf (1989) In a Collaboratory, the presentation/meeting concept embodied...
A quantum computer would put the latest PC to shame. Not only would such a device be faster than a conventional computer, but by exploiting the quantum-mechanical principle of superposition it could change the way we think about information processing. However, two key goals need to be met before a quantum computer becomes reality. The first is to be able to control the state of a single quantum bit (or 'qubit') and the second is to build a two-qubit gate that can produce 'entanglement' between the qubit states. (U.K.)
... Although other authors had made cross-spectral density measurements, Corcos pointed to the importance of this function as indicative of the true ...
A combination of computer codes such as LATREP, HWRAXAV and CITATION is utilized in an attempt to analyze the nuclear design characteristics of the CAXDU-PHWR of the Wolsung Unit 1. The major nuclear properties to be computed are the lattice properties of CANDU fuel channel and the core channel power distribution. The computed results are compared with the preliminary safety reports documentation for the Wolsung reactor. The observed discrepancies between our computations and the preliminary safety reports values are discussed in terms of incomplete information on the description of the core configuration in the preliminary safety reports and the different calculation methods. (author).
We study a quantum computing system using microwave photons in transmission line resonators on a superconducting chip as qubits. We show that linear optics and other controls necessary for quantum computing can be implemented by coupling to Josephson devices on the same chip. By taking advantage of the strong nonlinearities in Josephson junctions, photonic qubit interactions can be realized. We analyze the gate error rate to demonstrate that our scheme is realistic even for Josephson devices with limited decoherence times. As a conceptually innovative solution based on existing technologies, our scheme provides an integrated and scalable approach to the next key milestone for photonic qubit quantum computing.
The design of High-Voltage, Direct-Current transmission cables insulated with oil-impregnated cellulose paper is constrained by the maximum temperature and the maximum steady-state and transient stresses (voltage gradients) that the cable insulation can reliably withstand over the desired operating lifetime. Because the electrical stresses in the insulation are related in a very complex fashion to temperature, applied voltage and cable geometry, iterative techniques are required to compute the values of these stresses. Digital computers are ideally suited for these iterative techniques. This paper presents the principal equations and logic needed to develop suitable computer programs.
A progress report is presented on development of the WIPS computer code, a special purpose code for analysis of whip and impact in nuclear power piping. The computer code and final report are expected to be complete in December 1981. This progress report is an incomplete version of the final report, representing approximately 40% of the volume of the final report. Some sections in the report are complete, some are partially complete, and others are omitted. The report is intended to inform prospective WIPS users of the procedures, theories, and documentation standards which will be used for the computer code and the final report.
the progressive simplification of composite sandwich panels. The equations ... The thermal and structural behavior of composite sandwich panels with a ...
Objectives~%~ To quantify the volatile organic compound (VOC) emissions arising from the composting of a range of municipal and~%~ industrial wastes.~%~~%~ To relate the VOC emissions to the material being processed and the process conditions.~%~~%~ To confirm the findings of the above activites by monitoring full-scale composting operations.~%~~%~ To develop predictive models of VOC emissions in relation to waste feedstock and process conditions.~%~~%~ To produce guidance for plant designers, operators a [continued...]DescriptionA recent study of three composting plants undertaken for the Environment Agency has confirmed earlier work suggesting that waste composting can be a source of volatile organic compound (VOC) emissions. However, these experiments were restricted to garden and kitchen waste composting schemes and it was not ...
It is necessary to establish scenarios for reducing CO2 emissions and for developing CO2 emission control technologies to obtain a global consensus, using appropriate analytical models. For modification of the DNE-21 (Dynamic New Earth 21) model, it has a category designated as innovative technologies not involving CO2 emission and an optional consideration for the absorption of atmospheric CO2 by biomass. A global carbon circulation model, including vegetation in its scope, is also incorporated. Major results of the simulation are shown. When 20% reduction in CO2 emissions is required for only OECD countries after the year 2020, it has been demonstrated that CO2 concentration in the atmosphere will reach as high as about 900 ppm in 2100 due to CO2 emission by developing countries, and will not be a tolerable level. Under the condition that CO2 concentration in the atmosphere is ...
We propose to investigate the spontaneous emission of radiation arising out of the interaction of a relativistic electron beam with a metallic grating (the Smith-Purcell effect). The work will concentrate, primarily, in the 50-120 #mu#m part of the infrared spectrum and will be an extension of the work begun by the Oxford-Dartmouth-Essex collaboration; one of the early objectives of the project will be to develop a quantitative understanding of the power spectrum of the emitted radiation over a wide range of emission angles. In particular, the limits of relativistic peaking of forward directed emission will be investigated. The electron beam will be produced by laser irradiation of a metallic cathode in the terminal of a small Van de Graff accelerator located in the Technische Universitaet, Muenchen. Beam energies will be in the range of 2 - 4 MeV. Initial tests on photoproduction of electrons have yielded 10 mA pulses with ...
In order to establish the optimum fueling in a natural gas fueled dual fuel engine, tests were made for some operational parameters and their combination on the engine performances and the exhaust emissions. The results show that the gas oil quantity should be increased and gas oil injection timing should be advanced to suppress unburned hydrocarbon emission at middle and low output range, while the quantity should be reduced and the timing should be retarded to avoid onset of knock at high loads. The unburned hydrocarbon emission and the thermal efficiency are improved at the same load avoiding too lean natural gas premixture by restriction of intake charge air. However the improvement is limited because the ignition and initial combustion of pilot diesel fuel is deteriorated when the cylinder pressure is excessively lowered by throttling. The increase in pilot gas oil amount is effective for low-load operation and the ...
We aim to obtain a consistent description of non-thermal emissions from Abell 2256 and to give a prediction for a gamma-ray emission from this galaxy cluster. Assuming that a radio relic illuminates a localization of an ongoing merger, and that both radio and non-thermal part of hard X-ray emission are due to electron component of cosmic rays filling the relic, we derived from radio and hard X-ray properties of the relic in A2256 the magnetic field strength and number densities for relativistic electrons and protons. Due to the interpretation of the radio relic as a structure formed just where a shock front is, we discuss a gamma-ray emission at the cluster periphery. The estimated strength of the magnetic field in the relic is equal to 0.05 \\muG, while the amplitude of the electron number density varies from 3 x 10^{-4} to 3 x 10^{-5} cm^{-3} (respectively for the relic thickness of 50 to 500 kpc). We ...
Primordial black holes are unique probes of cosmology, general relativity, quantum gravity and non standard particle physics. They can be considered as the ultimate particle accelerator in their last (explosive) moments since they are supposed to reach, very briefly, the Planck temperature. Upper limits on the primordial black hole number density of mass $M_{\\star} = 5 10^{14}$ g, the Hawking mass (born in the big-bang terminating their life presently), is determined comparing their predicted cumulative $\\gamma$-ray emission, galaxy-wise, to the one observed by the EGRET satellite, once corrected for non thermal $\\gamma$-ray background emission induced by cosmic ray protons and electrons interacting with light and matter in the Milky Way. A model with free gas emissivities is used to map the Galaxy in the 100 MeV photon range, where the peak of the primordial black hole emission is expected. The best ...
For a direct injection diesel engine to exhibit its inherent low-emission characteristics, it is essential to improve control accuracy, in particular under transient operating conditions during which emissions are more noted. A model-based control system is established for exhaust gas recirculation (EGR) and air/fuel ratio, using a diesel-engine/vehicle model established on the CAD control system. Described herein are the results of simulation for optimizing control of transient conditions, and the emission-controlling effects confirmed by the field tests. The tests for verification of the established model have confirmed that there are good agreements between the simulated and observed results in terms of air/fuel ratio changing with EGR ratio, exhaust and intake gas and pressure levels, and vehicle speed. The model will be applicable to assessment of emission characteristics under varying conditions. ...
A detailed assessment of the consumption of mercury, divided into use areas, was carried out. Disposal and emissions to the environment were also qualified. The assessment is mainly based on data from 1992 - 1993. The most important source of emission of mercury to air is solid waste incineration which is assessed in particular to be due to the supply of mercury in batteries (most likely mercury oxide batteries from photo equipment) and to dental fillings. The second most important source of mercury emission to air is coal-fired power plants which are estimated to account for 200-500 kg of mercury emission p.a. Other mercury emissions are mainly related to waste treatment and disposal. The consumption of mercury is generally decreasing. During the period from 1982/83 - 1992-93, the total consumption of mercury in Denmark was about halved. This development is related to the fact that ...
A hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel was discussed in this presentation. A schematic diagram of the experimental study was first presented. The single cylinder, water-cooled, supercharged test engine was illustrated. Results were presented for the following: fuel energy and energy share (hydrogen and diesel fuel); pressure history and rate of heat release; engine performance and exhaust emissions; effect of nitrogen dilution on heat value per cycle; effect of N_2 dilution on pressure history and rate of heat release; and engine performance and exhaust emissions. This presentation demonstrated that smooth and knock-free engine operation results from the use of hydrogen in a supercharged dual-fuel engine for leaner fuel-air equivalence ratios maintaining high thermal efficiency. It was possible to attain mor3 than 90 per cent hydrogen-energy substitution ...
The United Nations Framework Convention on Climate Change (UNFCCC) was approved in 1992 to respond to the worl-wide concern about the warming of the planet. The primary target was the stabilization of the concentration of greenhouse gases in the atmosphere, in an attempt to reduce to the minimum the degradation of the environment caused by humans. By virtue of the Convention, the Parts2 are committed to reach their objectives in the reduction of the emissions. A Conference of the Parts was stablished to promote the effective application of the Convention. The third Conference of the Parts, celebrated in Kyoto (Japan, 1997) approved, by consensus, the denominated Kyoto Protocol, in which 39 developed countries and countries with economies in transition were committed to reduce their emissions of greenhouse gases between years 2008 and 2012 in a 5.2 global percent with respect to the 1990 levels. Three {sup f}lexibility mechanisms{sup w}ere ...
Context: The colliding-wind binary Eta Car exhibits soft X-ray thermal emission that varies strongly around periastron, and non-thermal emission seen in hard X-rays and gamma-rays. Aims: To definitively identify Eta Car as the source of the hard X-ray emission, to examine how changes in the 2-10 keV band influence changes in the hard X-ray band, and to understand more clearly the mechanisms producing the non-thermal emission using new INTEGRAL observations obtained close to periastron. Methods: A Chandra observation encompassing the ISGRI error circle was analysed, and all other soft X-ray sources (including the outer shell of Eta Car itself) were discarded as likely counter-parts. New hard X-ray images of Eta Car were studied close to periastron, and compared to previous observations far from periastron. Results: The INTEGRAL component, when represented by a power law (with a photon index of 1.8), ...
Ultra-luminous infrared galaxies are among the most luminous objects in the local universe and are thought to be powered by intense star formation. It has been shown that in these objects the rotational spectral lines of molecular hydrogen observed at mid-infrared wavelengths are not affected by dust obscuration, leaving unresolved the source of excitation of this emission. Here I report an analysis of archival Spitzer Space Telescope data on ultra-luminous infrared galaxies and demonstrate that star formation regions are buried inside optically thick clouds of gas and dust, so that dust obscuration affects star-formation indicators but not molecular hydrogen. I thereby establish that the emission of H_2 is not co-spatial with the buried starburst activity and originates outside the obscured regions. This is rather surprising in light of the standard view that H_2 emission is directly associated with star-formation ...
We present the results of a search for Extreme Ultraviolet emission in A4059, a cluster with an X-ray emitting cluster gas. Our analysis of Extreme Ultraviolet Explorer (EUVE) Deep Survey observations of this cluster shows that it is associated with diffuse EUV emission. Outside the central 2 arcmin radius the entire EUV emission detected is explained by the low energy tail of the X-ray emitting gas. Within the central 2 arcmin region of the cluster we find a deficit of EUV emission compared to that expected from the X-ray gas. This flux deficit is discussed in the context of the cluster's cooling flow. The results derived for A4059 are compared to EUVE results obtained for other clusters such as Coma, Virgo, A1795, and A2199. As part of the study we have carried out a detailed investigation of the stability of the EUVE Deep Survey detector background. Based on long integrations of blank sky over 27 ...
There is a great demand for the reduction of specific fuel consumption in diesel engines, and also of NO/sub x/ emission in especially those designed for use on land. However, while improving combustion, a problem arises in trying to reduce both simultaneously because the techniques required are contradictory. This series of experiments was done to study the correlation between specific fuel consumption and NO/sub x/ emission. The research was conducted under variations in engine parameters and operating conditions. The variations studied included effects of pressure, temperature and humidity of the charging air, temperature of the cooling water, timing and rate of fuel injection, fuel injection nozzle, EGR and water-emulsified fuel. The results of the tests clarified the characteristics of the specific fuel consumption and NO/sub x/ emission and indicated that the most-effective measures for the reduction of specific fuel ...
Los Alamos National Laboratory is subject to annual emissions-reporting requirements for regulated air contaminants under Title 20 of the New Mexico Administrative Code, Chapter 2, Part 73 (20.2.73 NMAC), Notice of Intent and Emissions Inventory Requirements. The applicability of the requirements is based on the Laboratory's potential to emit 100 tons per year of suspended particulate matter, nitrogen oxides, carbon monoxide, sulfur oxides, or volatile organic compounds. For calendar year 2001, the Technical Area 3 steam plant was the primary source of criteria air pollutants from the Laboratory, while research and development activities were the primary source of volatile organic compounds. Emissions of beryllium and aluminum were reported for activities permitted under 20.2.72 NMAC. Hazardous air pollutant emissions from chemical use for research and development activities were also reported.
This report describes results from emissions testing of a prototype diesel engine, developed by Volvo Truck Corporation of Sweden, which uses pilot injection of diesel fuel for compression ignition of alcohol fuel injection for main combustion. In addition to this dual-fuel engine, emission testing was also conducted on a heavy-duty diesel engine of similar design. Both engines were tested over the 1979 13-mode FTP, or shorter versions of this modal test, and over the 1984 Transient FTP as well as an experimental bus cycle. The dual-fuel engine was characterized with methanol, ethanol and ethanol with 30 percent water (wt %). An oxidation catalyst was also used with methanol and ethanol. Emission characterization included regulated emissions (HC, CO, and NOX) along with total particulate, unburned alcohols, individual hydrocarbons, aldehydes, phenols, and odor. The particulate matter was characterized ...
An experimental investigation was conducted to evaluate the effect of three different oxygenated compounds, diglyme, diethyl maleate and dibutyl maleate, on emissions from a Volkswagen 1.9 litre, turbocharged, direct injection diesel engine. Sampling was performed using a mini-dilution tunnel technique to obtain particulate matter and a Fourier transform infrared (FTIR) spectrometer for gaseous emissions. The particulate samples were analysed using thermal analysis and Soxhlet extraction to determine the fraction of volatile and soluble organic material respectively. All three oxygenated compounds were found to be effective at reducing particulate emissions, with the maleate compounds being more effective overall than the diglyme. Analysis of the relative contributions of changes in the soot and soluble organic fraction (SOF) to the reduction of particulate matter indicated that, for diethyl maleate and diglyme, reductions ...
This report describes the result of work completed during February, 1982 to October 1983. The aim of the work was to develop a low NO(x) emission range top burner. Discussed is the development of a flame insert modification to an existing burner which reduces NO(x) emission by 45 percent and NO2 emission by 25 percent. This relatively simple burner add-on device appears to be an economically viable low NO(x) burner. It was developed in cooperation with a major range manufacturer. The levels of NO(x) (NO2) reduction achieved should significantly reduce the impact of a gas range to indoor quality. The report also discusses the results of a literature search that preceeded the burner development. The search helped to direct the burner development by reviewing the state-of-the-art of low NO(x) burner design and covered factors which affect the indoor impact of range emissions such as air infiltration and ...
Biodiesel is an alternative fuel for internal combustion engines. It can reduce carbon monoxide (CO), hydrocarbon (HC) and particulate matter (PM) emissions, compared with diesel fuel, but there is also an increase in nitrogen oxides (NOx) emission. This study is aimed to compare the effect of applying a biodiesel with either 10% blended methanol or 10% fumigation methanol. The biodiesel used in this study was converted from waste cooking oil. Experiments were performed on a 4-cylinder naturally aspirated direct injection diesel engine operating at a constant speed of 1800 rev/min with five different engine loads. The results indicate a reduction of CO{sub 2}, NOx, and particulate mass emissions and a reduction in mean particle diameter, in both cases, compared with diesel fuel. It is of interest to compare the two modes of fueling with methanol in combination with biodiesel. For the blended mode, there is a slightly higher ...
In the framework of the European Fusion Technology Programme ECN participates in a NET task PSM-8 `Coatings and Surface Effects on Stainless Steel 316L`. High emissivity coatings were developed for enhanced heat transfer from graphite tiles to a Stainless Steel First Wall. Four candidate materials, Cr{sub 2}O{sub 3}, Black Cr, Al{sub 2}O{sub 3}/TiO{sub 2} and TiC were tested as candidate high emissivity coatings. These coatings were manufactured by atmospheric and vacuum plasma spraying technique and the Black Chromium coatings were manufactured by a galvanic coating technique. The tests included total emissivity measurements and Low Cycle Fatigue (LCF) experiments. The total emissivity of two TiC coatings at 525 K appeared to be 0.62 and 0.64. The total emissivity of the TiC and 5 wt% TiO{sub 2}/Al{sub 2}O{sub 3} coating was about 0.7. (orig.)
We present the X-ray properties of a sample of 17 radio sources observed with the Chandra X-ray Observatory as part of a project aimed at studying the X-ray emission from their radio jets. In this paper, we concentrate on the X-ray properties of the unresolved cores. The sample includes 16 quasars (11 core-dominated and 5 lobe-dominated) in the redshift range z=0.30--1.96, and one low-power radio-galaxy at z=0.064. No diffuse X-ray emission is present around the cores of the quasars, except for the nearby low-power galaxy that has diffuse emission on a scale and with a luminosity consistent with other FRIs. No high-amplitude, short-term variability is detected within the relatively short Chandra exposures. However, 1510-089 shows low-amplitude flux changes with a timescale of $\\sim$25 minutes. The X-ray spectra of the quasar cores are generally well described by a single power law model with Galactic absorption. However, ...
The major purpose of the work described in this report was to use diffusion modeling techniques to calculate the impact on ambient air quality of SO2 emissions from the ASARCO copper smelter in Tacoma, Washington for the existing smelter configuration (51-percent constant emissions control) and for 20 alternative smelter configurations with varying degrees of constant emissions control. The accuracy of the modeling techniques was established by the close correspondence obtained between calculated and observed short-term ground-level SO2 concentrations for 20 selected historical cases, when high hourly SO2 concentrations were measured in the area surrounding the smelter, as well as by the close agreement between calculated and observed annual average concentrations for 1972. The results of the model calculations show that the maximum allowable constant SO2 emission rate consistent with maintaining the ...
A sequential port injection, lean-burn, fully electronically-controlled compressed natural gas (CNG)/diesel dual-fuel engine has been developed based on a turbo-charged and inter-cooled direct injection (D.I.) diesel engine. During the optimisation of engine overall performance, the effects of pilot diesel and premixed CNG/air mixture equivalence ratio on emissions (CO, HC, NO{sub x}, soot), knocking, misfire and fuel economy are studied. The rich and lean boundaries of the premixed CNG/air mixture versus engine load are also provided, considering the acceptable values of NO{sub x} and THC emissions, respectively. It is interesting to find that there is a critical amount of pilot diesel for each load and speed point, which proved to be the optimum amount of pilot fuel. Any decrease in the amount of pilot diesel from this optimum amount results in an increase of NO{sub x} emissions, because the premixed CNG/air mixture must ...
Discusses alternative futures for distributing future personal computers, via data communications networks. The author scans and extrapolates some of the advances for impacting the emerging future of information utilities now sprouting up thoroughout the world. In particular he looks at the future of personal computers in the field of artificial intelligence,, for expert knowledge-based systems.