We Didn’t Fear the Reader: Embracing New Service Models With Staff and Patron Input

The book Transforming Acquisitions and Collection Services: Perspectives on Collaboration Within and Across Libraries explores new ways libraries can reach new standards in service, quality, and efficiency through cross-functional collaboration in acquisitions. Within libraries, the library acquisitions function can be combined with other units through close working relationships to support each group\u27s work. This chapter, titled We Didn\u27t Fear the Reader: Embracing New Service Models with Staff and Patron Input, details the organizational change and shifts in collection development philosophy at the Lehigh Libraries that led to more patron-centered policies and programs

The Fabrication, Testing and Simulation of Germanium Thermophotovoltaic Cells

This is the final report on NRL Contract N00173-79-C-0362. The purpose of this investigation was to fabricate germanium photovoltaic cells and to examine the feasibility of using them in a thermophotovoltaic system for the generation of electrical power in space. The energy source was to be solar. Systems aspects of the collection of solar energy and rejection of waste heat were not a part of this study. The strategy employed in this investigation was the following. 1. Fabricate germanium photodiodes. 2. Carefully characterize these photodiodes. 3. Simulate the performance of these photodiodes using a detailed numerical model of the cell and the illuminating spectra. 4. Use this simulation program to project the potential performance of germanium photodiodes in a thermophotovoltaic system under various assumptions about future improvements in diode performance and under various thermophotovoltaic spectral condition

Recommended Practice for Use of Faraday Probes in Electric Propulsion Testing

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143029/1/1.B35696.pd

Experimental observation and characterization of the magnetorotational instability

Differential rotation occurs in conducting flows in accretion disks and planetary cores. In such systems, the magnetorotational instability can arise from coupling Lorentz and centrifugal forces to cause large radial angular momentum fluxes. We present the first experimental observation of the magnetorotational instability. Our system consists of liquid sodium between differentially rotating spheres, with an imposed coaxial magnetic field. We characterize the observed patterns, dynamics and torque increases, and establish that this instability can occur from a hydrodynamic turbulent background.Comment: 4 pages, 5 figures. Final version, accepted for publication in Physical Review Letter

Effect of Background Pressure on the Plasma Oscillation Characteristics of the HiVHAc Hall Thruster

During a component compatibility test of the NASA HiVHAc Hall thruster, a number of plasma diagnostics were implemented to study the effect of varying facility background pressure on thruster operation. These diagnostics characterized the thruster performance, the plume, and the plasma oscillations in the thruster. Thruster performance and plume characteristics as functions of background pressure were previously published. This paper focuses on changes in the plasma oscillation characteristics with changing background pressure. The diagnostics used to study plasma oscillations include a high-speed camera and a set of high-speed Langmuir probes. The results show a rise in the oscillation frequency of the "breathing" mode with rising background pressure, which is hypothesized to be due to a shortening acceleration/ionization zone. An attempt is made to apply a simplified ingestion model to the data. The combined results are used to estimate the maximum acceptable background pressure for performance and wear testing

An efficient system for reliably transmitting image and video data over low bit rate noisy channels

This research project is intended to develop an efficient system for reliably transmitting image and video data over low bit rate noisy channels. The basic ideas behind the proposed approach are the following: employ statistical-based image modeling to facilitate pre- and post-processing and error detection, use spare redundancy that the source compression did not remove to add robustness, and implement coded modulation to improve bandwidth efficiency and noise rejection. Over the last six months, progress has been made on various aspects of the project. Through our studies of the integrated system, a list-based iterative Trellis decoder has been developed. The decoder accepts feedback from a post-processor which can detect channel errors in the reconstructed image. The error detection is based on the Huber Markov random field image model for the compressed image. The compression scheme used here is that of JPEG (Joint Photographic Experts Group). Experiments were performed and the results are quite encouraging. The principal ideas here are extendable to other compression techniques. In addition, research was also performed on unequal error protection channel coding, subband vector quantization as a means of source coding, and post processing for reducing coding artifacts. Our studies on unequal error protection (UEP) coding for image transmission focused on examining the properties of the UEP capabilities of convolutional codes. The investigation of subband vector quantization employed a wavelet transform with special emphasis on exploiting interband redundancy. The outcome of this investigation included the development of three algorithms for subband vector quantization. The reduction of transform coding artifacts was studied with the aid of a non-Gaussian Markov random field model. This results in improved image decompression. These studies are summarized and the technical papers included in the appendices