Pressurized fluidized-bed combustors (FBC) are becoming very popular, efficient, and environmentally acceptable replica for conventional boilers in Coal-fired and chemical plants. In this paper, we present neural network-based methods for chaotic behavior monitoring and control in FBC systems, in addition to chaos analysis of FBC data, in order to localize chaotic modes in them. Both of the normal and abnormal mixing processes in FBC systems are known to undergo chaotic behavior. Even though, this type of behavior is not always undesirable, it is a challenge to most types of conventional control methods, due to its unpredictable nature. The performance, reliability, availability and operating cost of an FBC system will be significantly improved, if an appropriate control method is available to control its abnormal operation and switch it to normal when exists. Since this abnormal operation develops only at certain times due to a sequence of transient behavior, then an appropriate abnormal behavior monitoring method is also necessary. Those methods has to be fast enough for on-line operation, such that the control methods would be applied before the system reaches a non-return point in its transients. It was found that both normal and abnormal behavior of FBC systems are chaotic. However, …

Polymer degradation occurs when polymer chains are broken under the influence of thermal, mechanical, or chemical energy. Chain-end depolymerization and random- and midpoint-chain scission are mechanisms that have been observed in liquid-phase polymer degradation. Here we develop mathematical models, unified by continuous-mixture kinetics, to show how these different mechanisms affect polymer degradation in solution. Rate expressions for the fragmentation of molecular-weight distributions (MWDs) govern the evolution of the MWDs. The governing integro-differential equations can be solved analytically for realistic conditions. Moment analysis for first-order continuous kinetics shows the temporal behavior of MWDs. Chain-end depolymerization yields monomer product and polymer molecular-weight moments that vary linearly with time. In contrast, random- and midpoint-chain scission models display exponential time behavior. The mathematical results reasonably portray experimental observations for polymer degradation. This approach, based on the time evolution of continuous distributions of chain length or molecular weight, provides a framework for interpreting several types of polymer degradation processes.

An estimate of the design capacity for Spent Nuclear Fuel Project systems producing Multi-Canister Overpacks is developed based on completing fuel processing in a two year period. The design basis capacity for systems relates the desired annual processing rate to potential operating inefficiencies which may be actually experienced to project a design capacity for systems. The basis for estimating operating efficiency factors is described. Estimates of the design basis capacity were limited to systems actually producing the Multi-Canister Overpack. These systems include Fuel Retrieval, K Basin SNF Vacuum Drying, Canister Storage Building support for Staging and Storage, and Hot Vacuum conditioning. The capacity of other systems are assumed to be derived from these system capacities such that systems producing a Multi-Canister Overpack are not constrained.

Measurements of the linewidths of submicrometer features made by different metrology techniques have frequently been characterized by differences of up to 90 nm. The purpose of the work reported here is to address the special difficulties that this phenomenon presents to the certification of reference materials for the calibration of linewidth-measurement instruments. Accordingly, a new test structure has been designed, fabricated, and undergone preliminary tests. Its distinguishing characteristics are assured cross-sectional profile geometries with known side-wall slopes, surface planarity, and compositional uniformity when it is formed in mono-crystalline material at selected orientations to the crystal lattice. To allow the extraction of electrical linewidth, the structure is replicated in a silicon film of uniform conductivity which is separated from the silicon substrate by a buried oxide layer. The utilization of a Silicon-On-Insulator (SKI) substrate further allows the selective removal of substrate material from local regions below the reference features, thus facilitating measurements by optical and electron-beam transmission microscopy. The combination of planar feature surfaces having known side-wall slopes is anticipated to eliminate factors which are believed to be responsible for methods divergence in linewidth measurements, a capability which is a prerequisite for reliable certification of the linewidths of features on reference …

Currently, there is a widespread search for additional heterogeneous reactions or combination of heterogeneous and homogeneous (gas-phase) reactions that could catalytically reduce ozone to observed levels. In 1992, Burley and Johnston proposed that nitrosyl sulfuric acid (NSA) NOHSO{sub 4}, is a promising heterogeneous reactant for activating HCl in sulfuric acid particles. They list several sources for producing it in the stratosphere and they carried out thermodynamic and chemical kinetic calculations at one stratospheric altitude and at one latitude. NSA has been overlooked in all previous stratospheric model calculations, even though it has been observed in stratospheric sulfate aerosols. This study makes large scale atmospheric model calculations to test the proposal by Burley and Johnston that a promising heterogeneous process for activating HCl in sulfuric acid particles is a catalytic coupled based on nitrosyl sulfuric acid (NSA). This mechanism is examined under non-volcanic and volcanic conditions representative of the recent eruption of Mt. Pinatubo. The calculations set firm limits on the range of kinetic parameters over which this heterogeneous processes would be important in the global ozone balance, and thus is a guide for where laboratory work is needed. In addition, they have derived a preliminary time-dependent integration (1980--1994) to represent …

This document details the Software Acceptance Testing of gas characterization systems. The gas characterization systems will be used to monitor the vapor spaces of waste tanks known to contain measurable concentrations of flammable gases.

ADS has developed an ion chromatographic method which enables low part-per-billion levels of analysis while minimizing liquid waste generation. This method incorporates several recent technical improvements in ion chromatographic instrumentation to achieve a ten- fold increase in sensitivity over existing ion chromatographic methods without additional analysis time or sample pre-concentration. This report outlines the method, establishes the precision and accuracy levels, and discusses the applicability of the method to waste minimization and radiation exposure reduction

Pressures are mounting for a regime to verify the dismantlement of US and Russian warheads, as well as a system of international control over the weapons` fissile materials to assure irreversibility. There are at least four motivating factors for these measures: (1) as the United States and Russia lower their numbers of nuclear weapons, each side seeks assurance that the warheads are actually being dismantled; (2) by accounting for the fissile materials and placing them under effective controls, the potential for smuggling and theft is reduced; (3) a fissile materials cutoff is being discussed at the Conference on Disarmament in Geneva; verification of a US-Russian cutoff, as well as substantial reductions in fissile materials stockpiles, are seen as integral to the cutoff; (4) calls for total nuclear disarmament have greatly increased; dismantlement verification and international control of fissile materials are widely viewed as requisite steps toward this goal. There are many questions to be answered before the United States can agree to a warhead verification regime and international control over excess fissile materials, let alone total nuclear disarmament. Two of the most important are: What are the prospects for effective verification? and How much fissile material can be declared as …

A remote measurement system has been constructed for in situ gamma and beta isotopic characterization of highly radioactive nuclear material in hostile environments. A small collimated, planar CdZnTe detector is used for gamma-ray spectroscopy. Spectral resolution of 2% full width at half maximum at 662 kiloelectronvolts has been obtained remotely using rise time compensation and limited pulse shape discrimination, Isotopc measurement of high-energy beta emitters was accomplished with a ruggedized, deeply depleted, surface barrier silicon dictator. The primary function of the remote nuclear screening system is to provide fast qualitative and quantitative isotopic assessment of high-level radioactive material.

Analysis of crosswell and three-component seismic data integrated with well logs have produced information on the distribution of subsurface heterogeneities below the In-Tank Precipitation facility at the Savannah River Site (SRS). The travel time P-wave tomogram and reflection imaging delineate lateral and vertical structural details of the formations. In particular, the high-resolution P-wave tomogram captures a low-velocity zone within the carbonates. This zone is surrounded by reflection events between depths of 150 and 200 ft. in the reflection imaging. The reflections are caused by the acoustic impedance contrast between the low velocity zone of `soupy` sand mixtures of unconsolidated materials and the more rigid and dense competent surrounded medium. The time-frequency analysis of full waveforms particle velocity identifies guided waves in form of leaky and normal modes at the depths of about 138 to 150 ft. This resulting change in lithology associated with the presence of guided waves is consistent with a velocity low observed in the vertical velocity profile determined from the inversion of three-component seismic data. This low-velocity zone intercepted by the wells H-BOR-34 and H-BOR-50 correlates with the conductive Griffins Landing Member, which is located above the carbonates. The result of the experiments demonstrate that the present …

Optical parametric oscillators (OPOS) are useful devices to generate tunable radiation. The tuning characteristics of OPOs can lead to their utility in remote sensing applications. We have investigated injection-seeded OPOs to generate narrow-band Mid-JR radiation for this purpose. OPOs exhibit a resonance structure similar to that of a laser`s cavity limiting the frequency choices available. Also, the coupling of the electric fields of the three interacting waves can generate cavity resonances for OPOs which have no cold cavity resonances (i.e. non-resonant OPOS). The potential for generating multiple frequencies simultaneously from a single OPO is discussed. The generation of multiple output frequencies is accomplished by injecting either multiple signal or multiple pump frequencies to the OPO. A seeded SRO is found to be well-suited to generating spectrally pure and stable multi-line output when the input pump field is multiple frequency. The generation of sideband frequencies during multiple seeding is also observed experimentally and addressed theoretically. The spectral purity of the OPO output is related to the frequency separation of the multi-line input as compared to the OPO cavity resonance structure.

The supporting safety documentation for subsurface construction of the canister storage building provides the safety documentation to support Key Decision 3b for the Canister Storage Building project.

This paper explores two issues on TOP performance over ATM networks: ABR parameter tuning and performance comparison of binary mode ABR with enhanced UBR services. Of the fifteen parameters defined for ABR, two parameters dominate binary mode ABR performance: Rate Increase Factor (RIF) and Rate Decrease Factor (RDF). Using simulations, we study the effects of these two parameters on TOP over ABR performance. We compare TOP performance with different ABR parameter settings in terms of through-puts and fairness. The effects of different buffer sizes and LAN/WAN distances are also examined. We then compare TOP performance with the best ABR parameter setting with corresponding UBR service enhanced with Early Packet Discard and also with a fair buffer allocation scheme. The results show that TOP performance over binary mode ABR is very sensitive to parameter value settings, and that a poor choice of parameters can result in ABR performance worse than that of the much less expensive UBR-EPD scheme.