The experimental investigations performed within the scope of the present contribution are carried out in a lab scale filter test rig, which is built according to German VDI guideline 3926. The filter coupon (15 cm diameter) under investigation is mounted parallel to the crude gas channel which enables cross flow filtration as experienced in filter housings. Besides the photometric concentration monitor and the control device, an optical measuring system is mounted on the filter test rig opposite the filter coupon. This measuring system enables the full-field in situ measurement of the dust cake height distribution on the surface of the filter medium. From these measurements, we obtain the overall frequency of regeneration as well as the local frequencies of regeneration and the patch size distribution, as discussed later. In addition, we investigate the influence of the regeneration behavior on the filtration performance (time dependence of filtration cycle times and residual pressure drop) of the filter medium.

The amplitude dependent mechanical loss due to bosing of an idealized Frank-Read Source is studied using both simulation and analytical techniques. Dislocations are modeled within isotropic elasticity theory, and are assumed to be in the over-damped limit.

The purpose of this paper is to analyze the increasing mechanism of cohesive and adhesive force of ash powders from a coal combustion system at high-temperature conditions, a new observation system, which was composed of computer controlled FE-SEM and chamber unit for the heat treatment, was developed. By using this system, the liquid phase formation on the surface of pressurized fluidized bed coal combustion ash samples was observed after heat treatment at 1123 K, which temperature was corresponding to the rapid increasing temperature of adhesion behavior of ash powder samples.

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Primary issues for the fluidized-bed/transport reactor process are high attrition resistant sorbent, its high sorption capacity and regenerability, durability, and cost. The overall objective of this project is the development of a superior attrition resistant zinc oxide-based sorbent for hot gas cleanup in integrated coal gasification combined cycle (IGCC). Sorbents applicable to a fluidized-bed hot gas desulfurization process must have a high attrition resistance to withstand the fast solid circulation between a desulfurizer and a regenerator, fast kinetic reactions, and high sulfur sorption capacity. The oxidative regeneration of zinc-based sorbent usually initiated at greater than 600 C with highly exothermic nature causing deactivation of sorbent as well as complication of sulfidation process by side reaction. Focusing on solving the sorbent attrition and regenerability of zinc oxide-based sorbent, we have adapted multi-binder matrices and direct incorporation of regeneration promoter. The sorbent forming was done with a spray drying technique that is easily scalable to commercial quantity.

Alternative alloys derived from the wide array of aerospace superalloys will be developed for hot gas filtration to improve on both ceramic filters and ''first-generation'' iron aluminide metallic filter materials. New high performance metallic filters should offer the benefits of non-brittle mechanical behavior at all temperatures, including ambient temperature, and improved resistance to thermal fatigue compared to ceramic filter elements, thus improving filter reliability. A new powder processing approach also will be established that results in lightweight metallic filters with high permeability and weldability for enhanced capability for filter system manufacturing.

Coal gasification produces residual particles of coal char, coal ash, and sorbent that are suspended in the fuel gas stream exiting the gasifier. In most cases, these particles (referred to, hereafter, simply as char) must be removed from the stream prior to sending the gas to a turbine, fuel cell, or other downstream device. Currently, the most common approach to cleaning the gas stream at high temperature and pressure is by filtering the particulate with a porous ceramic or metal filter. However, because these dusts frequently have small size distributions, irregular morphology, and high specific surface areas, they can have very high gas flow resistance resulting in hot-gas filter system operating problems. Typical of gasification chars, the hot-gas filter dustcakes produced at the Power Systems Development Facility (PSDF) during recent coal gasification tests have had very high flow resistance (Martin et al, 2002). The filter system has been able to successfully operate, but pressure drops have been high and filter cleaning must occur very frequently. In anticipation of this problem, a study was conducted to investigate ways of reducing dustcake pressure drop. This paper will discuss the efficacy of adding low-flow-resistance particulate matter to the high-flow-resistance char dustcake to reduce …

Stable operation, characterized by a succession of uniform filtration cycles with acceptable duration and pressure increase, remains a key issue in high temperature gas filtration. Ceramic filters are known to sometimes become instable. This is somehow related to ''patchy cleaning'', but cause-and-effect relationships have been difficult to identify. The objective of this contribution is to investigate incomplete regeneration patterns in detail, to try to classify them, and to identify relationships between the residual cake patterns and the form of successive filtration cycles. The work comprises both modeling and experiments at room temperature and high temperature conditions on ceramic media using quartz dust and bark ash.

The objective of this study is to evaluate the mechanical properties of the cylindrical ceramic filter elements under vibration. These vibrations with different frequencies and amplitudes occur particularly in up/down-turning periods and during pulse cleaning but even under regular operation conditions. The geometry of a filter element with a wall thickness of about 10 mm, an outer diameter of 60 mm and an overall length of about 1500 mm with a porous support structure is not typical for ceramic materials. Therefore the risk of mechanical fatigue is high. As a result of the theoretical calculations an optimization of the element geometry shall be achieved. The optimization has to take into account the possibilities for an industrial fabrication of the elements, the possibility of a substitution in existing filter systems and of course a high filter area similar to the usual geometry has to be guaranteed.

The primary research objective of this effort is to develop a portable, capillary electrophoresis microchip capable of sensitively and rapidly monitoring hazardous waste metal ions critical to the successful deactivation and decommissioning (D&D) of contaminated equipment and structures at various DOE sites. Hazardous waste metal ions to be adapted for sensing on the microchip include UO{sub 2}{sup 2+}, Be{sup 2+}, Cr{sup 6+}, Hg{sup 2+}, Pb{sup 2+}, Co{sup 2+}, Ni{sup 2+}, Cs{sup +}, and Sr{sup 2+}. Particular emphasis will be placed on developing viable, new extraction methods for metal ion sampling from both the air via a microimpinger which is integrated onto the microchip itself, and from contaminated surfaces, both techniques being amenable to on-line introduction onto the microchip. Two different detection methods for monitoring the electrophoretic separations taking place down the microchannel will be exploited in this research, indirect and direct detection. Special emphasis will be placed on maintaining the ultimate portability of the final microchip device through the careful selection of metallochromic dyes and fluorophores which are amenable to use of small, inexpensive light sources (e.g., LED's) and photodetectors.

The objective of this study is to evaluate changes in structure and mechanical properties of ceramic filter materials under simulated corrosive process conditions. Due to an analysis of the mechanisms of degradation firstly an optimization of materials shall be enabled and secondly a material selection for specific applications shall be relieved. This publication describes the investigations made on many ceramic support materials based on oxides and carbides. Both commercially available and newly developed support materials have been evaluated for specific applications in hot gas cleaning.

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The use of syngas from waste or biomass gasification to generate electricity is a way which is attracting increasing attention especially with regard to the demands of regenerable energy consumption and to the reduction of waste disposal. In order to feed the syngas to a gas motor or a gas turbine the gas has to be cleaned. In future also the coupling of biomass gasification with a fuel cell will be applied, which needs a very efficient gas cleaning. The decomposition of tars and the removal of particles from the gas are the key issues of gas cleaning. Up to now these two steps are performed in two separate units. Normally, the tars are decomposed in catalytic beds or honeycomb structures. The catalytic decomposition is achieved at temperatures between 750 C and 900 C depending on the catalyst used. Particles are removed by filtration of the hot gas. Filtration at high temperatures and with high efficiencies is possible when using ceramic filter elements. Ceramic hot gas filters are well established in advanced coal gasification, such as the integrated gasification combined cycle process, as well as in waste and biomass gasification and pyrolysis processes. Since the catalytic reaction requires high temperatures …

The present paper intended to present the results of parametric study of the formation of ammonia and tar under pressurized gasification conditions. By the use of multivariate data analysis, the effects of operating parameters were determined and their influences could be quantified. In order to deal with cases in which high levels of ammonia and tar were produced, study of catalytic hot gas cleaning was performed, aiming to discuss the removal efficiency and test catalysts.

OAK-B135 Metalloenzymes seem to ''come of age'' when their structures are known at atomic resolution, spectroscopic and catalytic properties are basically understood, and genetic expression systems are available. Such foundations allow detailed mechanistic and spectroscopic properties to be probed and correlated to structure. The objective of this article is to summarize what is known about the title group of enzymes, and show that, to a large degree, they have come of age.

This paper describes the procedures for setting up the transfer lines for the Spallation Neutron Source (SNS). The High Energy Beam Transfer (HEBT) is about 170 meters long and has two achromat sections, an energy corrector cavity, energy spreader cavity, and transverse and longitudinal collimators. The Ring to Target Beam Transfer (RTBT) line is about 150 meters long has an achromat, transverse collimators and a beam spreader section. It will be shown that with the available diagnostics one can first characterize the incoming beam in both lines and then, with types and locations of the diagnostics and beam tuning ''knobs'', set up to deliver an output beam with the desired properties.

The objective of this collaboration between Argonne National Laboratory (ANL) and the Central Research Institute of Electric Power Industry (CRIEPI) is to evaluate the effects of long-term, low-dose neutron exposure on the mechanical properties, dimensional stability, and associated microstructural changes of reactor structural materials. ANL believes that material data obtained from components irradiated in EBR-II provide valuable information that is useful for LWR plant life extension. CRIEPI is currently conducting research on many aspects of materials aging of LWR components including irradiation damage. Therefore, ANL and CRIEPI have decided to perform the following joint work, which is of interest to both laboratories and continues the collaborative relationship between the two labs. The program was initiated in February of 1999. Samples were taken from two separate subassemblies, designated S1951 and S1952. These subassemblies were constructed of 20% cold-worked Type 316 stainless steel. The samples from these subassemblies were irradiated at temperatures from 371-390 C to doses up to 56 dpa. The examinations in this program included: immersion density, microhardness, microstructure, and tensile properties. The material history, test plan, results of measurements, and discussion of results are included in this report.

Natural gas transmission companies mark the right-of-way areas where pipelines are buried with warning signs to prevent accidental third-party damage. Nevertheless, pipelines are sometimes damaged by third-party construction equipment. A single incident can be devastating, causing death and millions of dollars of property loss. This damage would be prevented if potentially hazardous construction equipment could be detected, identified, and an alert given before the pipeline was damaged. The Gas Technology Institute (GTI) is developing a system to solve this problem by using an optical fiber as a distributed sensor and interrogating the fiber with an custom optical time domain reflectometer. Key issues are the ability to detect encroachment and the ability to discriminate among potentially hazardous and benign encroachments. The work performed in the third quarter of the project (2nd quarter of 2002) includes design of the diode laser driver and high-speed detector electronics and programming of the custom optical time domain reflectometer.

This is a summary of the talks presented in Session III ''Simulations of Electron-Cloud Build Up'' of the Mini-Workshop on Electron-Cloud Simulations for Proton and Positron Beams ECLOUD-02, held at CERN, 15-18 April 2002.

Assessing the impact of radioactive and hazardous chemical waste disposal on man is an important problem in environmental science and engineering. This report illustrates the mathematical evolution of the compartmental model from small to large systems and provides examples of the use of the compartmental approach in analysis of transport of radionuclide and chemical contaminants.

The Interstate Clean Transportation (ICTC) purpose is to develop a public-private partnership dedicated to accelerating the market penetration of clean, alternative fuel vehicles (AFVs) in interstate goods movement. In order to foster project development, the ICTC activity sought to increase awareness of heavy-duty AFVs among truck fleet operators.

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The Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Test Reactor (ATR), a DOE Category A reactor, was designed to provide an irradiation test environment for conducting a variety of experiments. The ATR Safety Analysis Report, determined by DOE to meet the requirements of 10 CFR 830, Subpart B, provides versatility in types of experiments that may be conducted. This paper addresses two general types of experiments in the ATR facility and how safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore this type of experiment is addressed with more detail in the safety basis. This allows individual safety analyses for these experiments to be more routine and repetitive. The second type of experiment is less defined and is permitted under more general controls. Therefore, individual safety analyses for the second type of experiment tend to be more unique from experiment to experiment. Experiments are also discussed relative to ''major modifications'' and DOE-STD-1027-92. Application of the USQ process to ATR experiments is also discussed.

Polycrystals of the intermetallic compound of the Dy{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} system, where x = 0, 0.25, 0.5, 0.625, 0.675, 0.725, 0.75, 0.775, 0.825, 0.875, and 1, have been prepared by electric-arc-melting on water-cooled copper hearth in an argon atmosphere. A study of phase relationships and crystallography in the pseudobinary system Dy{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} using X-ray powder diffraction data and optical metallography was completed. It revealed that silicides in the composition range from 0.825 to 1 crystallize in the Gd{sub 5}Si{sub 4}-type crystal structure: germanides in the composition range from 0 to 0.625 crystallize in the Sm{sub 5}Ge{sub 4}-type structure, and alloys with intermediate composition range from 0.675 to 0.775 crystallize in the monoclinic Gd{sub 5}Si{sub 2}Ge{sub 2}-type structure. The -{Delta}S{sub m} values were determined from magnetization measurements for 7 alloys. The alloys with a monoclinic crystal structure which belong to an intermediate phase region have large MCE value, which exceeds those observed in the other two phase regions by 300 to 500%. The nature of the observed magnetic and structural transformations in the Dy{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} system seems to be similar with those reported for the Gd{sub 5}(Si{sub x}Ge{sub 1-x}){sub 4} system. However, the …