Optimization of thermal systems with sensitive optics, electronics, and structures

A strategy was investigated by which thermal designers for spacecraft could devise an optimal thermal control system to maintain the required temperatures, temperature differences, changes in temperature, and changes in temperature differences for specified equipment and elements of the spacecraft's structure. Thermal control is to be maintained by the coating pattern chosen for the external surfaces and heaters chosen to supplement the coatings. The approach is to minimize the thermal control power, thereby minimizing the weight of the thermal control system. Because there are so many complex computations involved in determining the optimal coating design a computerized approach was contemplated. An optimization strategy including all the elements considered by the thermal designer for use in the early stages of design, where impact on the mission is greatest, and a plan for implementing the strategy were successfully developed. How the optimization process may be used to optimize the design of the Space Telescope as a test case is demonstrated

Error control for reliable digital data transmission and storage systems

A problem in designing semiconductor memories is to provide some measure of error control without requiring excessive coding overhead or decoding time. In LSI and VLSI technology, memories are often organized on a multiple bit (or byte) per chip basis. For example, some 256K-bit DRAM's are organized in 32Kx8 bit-bytes. Byte oriented codes such as Reed Solomon (RS) codes can provide efficient low overhead error control for such memories. However, the standard iterative algorithm for decoding RS codes is too slow for these applications. In this paper we present some special decoding techniques for extended single-and-double-error-correcting RS codes which are capable of high speed operation. These techniques are designed to find the error locations and the error values directly from the syndrome without having to use the iterative alorithm to find the error locator polynomial. Two codes are considered: (1) a d sub min = 4 single-byte-error-correcting (SBEC), double-byte-error-detecting (DBED) RS code; and (2) a d sub min = 6 double-byte-error-correcting (DBEC), triple-byte-error-detecting (TBED) RS code

Towards a Phenomenology of Objects: Husserl and the Life-World

In this paper, I explore Edmund Husserl's account of the life-world for evidence that he posits it as the living flesh of the transcendental ego and thus as our primordial object-relation. In so doing, I attempt to rehabili­tate and defend Husserl's notion of transcendental subjectivity, of the a priori, by noting how one's embodiment in many concrete experiences calls for and bears witness to this transcendental foundation of itself. After developing my reading of Husserl's account of the life-world, I then turn to the phenomenological psychology of John Russon in his book Human Experience to show how Husserl's life-world as the pri­mordial object-relation opens us onto a very concrete vision of intersubjectivity

The Anatomy of Antiliberalism

A Review of The Anatomy of Antiliberalism by Stephen Holme

The National Solar Energy Research Institute: Function, Organization, and the First Six Months

The role of the Solar Energy Research Institute (SERI) in the national solar program is discussed. A brief history of developments leading to the formation of SERI is included. Functional responsibilities, organization and the current plans for staff and facilities growth are addressed

COSMOS 2044: Lung morphology study, experiment K-7-28

Researchers examined the effect of microgravity during spaceflight on lung tissue. The ultrastructure of the left lungs of 5 Czechoslovakian Wister rats flown on the 13 day, 19+ hour Cosmos 2044 mission was examined and compared to 5 vivarium and 5 synchronous controls at 1-g conditions, and 5 rats exposed to 14 days of tail suspension. Pulmonary hemorrage and alveolar adema of unknown origin occurred to a greater extent in the flight, tail-suspended, and synchronous control animals, and in the dorsal regions of the lung when compared with the vivarium controls. The cause of these changes, which are possibly due to an increase in pulmonary vascular pressure, requires further investigation

Study of a colliding laser-produced plasma by analysis of time and space-resolved image spectra

The interaction of two counter-propagating laser-produced plasmas was studied using simultaneous imaging and spectroscopic techniques. Spectrally-filtered time-gated ICCD imaging was used to obtain information about the spatial dynamics and temporal evolution of the collision process. While, time-resolved imaging spectroscopy was used to determine the spatial and temporal distributions of electron temperature and density within the interaction region. We examine specifically the interaction of plasmas whose parameters match those typically used in pulsed laser deposition of thin films. These low temperature plasmas are highly collisional leading to the creation of a pronounced stagnation layer in the interaction region

Methods of designing cascade blades with prescribed velocity distributions in compressible potential flows

By use of the assumption that the pres=sure-vohm.erelation is linear, a solution to the problem of designing a cascadefor a given turning and with.a prescribed relocity distribution along the blade in a potential$ow of a compressibleperfectfluid was obtained by a.method of correspondence betweenpokmtial$ows of mwnprewibkand incompressible$uids. The dew”gningof a-n i~olatedaifm”l un”th.a prescm”bedveloci~ydistn”butionalong the airfoil is considered as a.speet”alcase of the cascade. If the prescribed celocity distribution. is not theoretically attainable, the method prorides a means of modifying tlk dis-tribution so as to obtain a physically signi$cant bladeshape. Numerical examples are included