ALBERT

Description: Results are presented of an investigation of gasification and clean fuels from coal. Factors discussed include: coal and coal transportation costs; clean liquid and gas fuel process efficiencies and costs; and cost, performance, and environmental intrusion elements of the integrated low-Btu coal gasification system. Cost estimates for the balance-of-plant requirements associated with advanced energy conversion systems utilizing coal or coal-derived fuels are included.

Description: The microwave spectrometer on the Nimbus 5 earth observatory satellite has been used to measure thermal radiation in five frequency bands between 22.235 and 58.8 GHz. Clouds were observed to affect less than 0.5% of the temperature profile soundings. Most such effects occur in the intertropical convergence zone and alter the inferred temperature profile by less than a few degrees Centigrade. These effects are evident as cold spots at 53.65 GHz and can be identified by virtue of their small spatial extent, in contrast to smooth variations characteristic of normal atmospheric temperature fields. These effects at 53.65 GHz are sufficiently well correlated with inferred liquid water abundances that they can be used for detecting major storm systems over both land and sea.

Description: Analysis of pressure on flat plate near jet exhausting transverse to plate by inviscid flow models

Description: We present an active learning algorithm for inferring extended finite state machines (EFSM)s, combining data flow and control behavior. Key to our learning technique is a novel learning model based on so-called tree queries. The learning algorithm uses the tree queries to infer symbolic data constraints on parameters, e.g., sequence numbers, time stamps, identifiers, or even simple arithmetic. We describe sufficient conditions for the properties that the symbolic constraints provided by a tree query in general must have to be usable in our learning model. We have evaluated our algorithm in a black-box scenario, where tree queries are realized through (black-box) testing. Our case studies include connection establishment in TCP and a priority queue from the Java Class Library.

Description: Microscopic thermal-contact pads that include carpet-like arrays of carbon nanotubes have been invented for dissipating heat generated in integrated circuits and similarly sized single electronic components. The need for these or other innovative thermal-contact pads arises because the requisite high thermal conductances cannot be realized by scaling conventional macroscopic thermal-contact pads down to microscopic sizes. Overcoming limitations of conventional thermal-contact materials and components, the carbon-nanotube thermal-contact pads offer the high thermal conductivities needed to accommodate the high local thermal power densities of modern electronic circuits, without need for large clamping pressures, extreme smoothness of surfaces in contact, or gap-filling materials (e.g., thermally conductive greases) to ensure adequate thermal contact. Moreover, unlike some conventional thermal-contact components, these pads are reusable. The figure depicts a typical pad according to the invention, in contact with a rough surface on an electronic component that is to be cooled. Through reversible bending and buckling of carbon nanotubes at asperities on the rough surface, the pad yields sufficiently, under relatively low contact pressure, that thermal contact is distributed to many locations on the surface to be cooled, including valleys where contact would not ordinarily occur in conventional clamping of rigid surfaces. Hence, the effective thermal-contact area is greater than that achievable through scaling down of a macroscopic thermal-contact pad. The extremely high longitudinal thermal conductivities of the carbon nanotubes are utilized to conduct heat away from potential hot spots on the surface to be cooled. The fibers protrude from a layer of a filler material (Cu, Ag, Au, or metal-particle- filled gels), which provides both mechanical support to maintain the carbon nanotubes in alignment and thermal conductivity to enhance the diffusion of concentrated heat from the nanotubes into the larger adjacent volume of a heat sink. The array of carbon nanotubes, the filler material, and the heat sink are parts of a unitary composite structure that is fabricated as follows: 1. Using techniques that have been reported previously, the array of substantially perpendicularly oriented carbon nanotubes is grown on a metal, silicon, or other suitable thermally conductive substrate that is intended to become the heat sink. 2. By means of chemical vapor deposition, physical vapor deposition, plasma deposition, ion sputtering, electrochemical deposition, or casting from a liquid phase, some or all of the interstitial volume between carbon nanotubes is filled with the aforementioned layer of mechanically supporting, thermally conductive material. 3. To cause the carbon nanotubes to protrude the desired length from the filler material, an outer layer of filler is removed by mechanical polishing, chemical mechanical polishing, wet chemical etching, electrochemical etching, or dry plasma etching.

Description: Passive microwave sensing techniques can be used to obtain the temperature of the atmosphere, and to infer liquid water, water vapor and other molecular species over ocean or above the troposphere. The use of satellite-borne passive microwave radiometers is discussed along with the future use of the instrument on Nimbus-G and on the space shuttle.

Description: No abstract available

Description: Systems engineering involves both the integration of the system and the integration of the disciplines which develop and operate the system. Integrating the disciplines is a sociological effort to bring together different groups, who often have different terminology, to achieve a common goal, the system. The focus for the systems engineer is information flow through the organization, between the disciplines, to ensure the system is developed and operated will all relevant information informing system decisions. The practical application of the sociology in systems engineering brings in various organizational development concepts including the principles of planned renegotiation and the application of principles to address information barriers created by organizational culture. Concepts such as specification of ignorance, consistent terminology, opportunity structures, role-sets, and the reclama (reconsideration) process are all important sociological approaches that help address the organizational social structure (culture). In bringing the disciplines together, the systems engineer must also be wary of social ambivalence, social anomie, social dysfunction, and insider-outsider behavior. Unintended consequences can result when these social issues are present. These issues can occur when localized subcultures shift from the overarching organizational culture, or when the organizational culture prevents achievement of system goals. These sociological principles provide the systems engineer with key approaches to manage the information flow through the organization as the disciplines are integrated and share their information and provides key sociological barriers to information flow through the organization. This paper will discuss the practical application of sociological principles to systems engineering.

Description: Recent drought events in California and legislation passed with the goal of increasing the sustainability of groundwater supplies have led to increased interest in tools to optimize irrigation schedules and increase on-farm water used efficiency. With more than 400 different crops produced in California, evapotranspiration-based irrigation scheduling is a promising and well-established approach. However, there is a need for accurate methods to estimate crop evapotranspiration (ET(sub c)) across the diverse range of crops grown, coupled with cost-effective methods for quantifying the accuracy of these tools. In this study, we evaluated remotely sensed estimates of ET(sub c) and associated crop water requirements from NASA's Satellite Irrigation Support (SIMS) system for two vegetable crops and measured crop evapotranspiration ET(sub c) using multiple methods, including weighing lysimeters, eddy covariance towers (EC), and surface renewal stations. We compared ET(sub c) data from these measurements with remotely sensed basal crop evapotranspiration (ET(sub cb)) data from SIMS as well as ET(sub c) data from a standard FAO-56 crop coefficient approach. Studies were conducted for sugar beets in Five Points, CA from 2014 to 2015 and studies are ongoing for fresh market tomatoes in Firebaugh, CA. We present results from these intercomparison studies and describe implications for future studies to quantify the accuracy of remotely sensed measures of ET(sub c). Highlights from results to date include strong correlations between ET measured with both surface renewal instrumentation and eddy covariance calculations using a 3D sonic anemometer and ET(sub c) data measured with the weighing lysimeter, with respective R2 values of 0.7964 (surface renewal) and 0.8034 (eddy covariance). This study provides insights into agreement between different approaches for monitoring evapotranspiration and provides another reference point for the community working to develop accurate and cost-effective tools that support growers in optimizing irrigation management.

Description: Off-axis incident radiation, resulting from misalignment of a concentrator relative to incident solar flux, can potentially result in high flux concentrations at positions other than the design focal point. It is suggested that the impact of these concentrations should be considered when choosing materials and thermal control strategies for structures adjacent to the concentrator. A numerical (ray tracing) analysis of the effects of off-axis radiation on the proposed solar concentrator for the Space Station Freedom is performed. The magnitude and position of the reflected flux peaks are identified for a matrix of off-axis angles and target distances. The principles of geometric optics are presented to illustrate that the results of the numerical study are justified, and these results are explained in terms of these basic optical principles. A method that allows prediction of the reflected flux field for a generalized parabolic reflective concentrating system is presented.