Development of a ninety string solar array simulator

A power source was developed to support testing for the Space Station Freedom Power Management and Distribution (PMAD) DC Testbed. The intent was to simulate as closely as possible the steady-state and transient responses of a solar array. Several breadboards and one thermal prototype were built and tested. Responses were successfully verified and improved upon during successive breadboards. The completed 90-string simulator consists of four power MOSFETs, four 25 watt source resistors, and four 250 watt drain source bypass resistors per string, in addition to the control circuitry

Legal Rights of Students in the Public Schools: A Descriptive Case Study of the Center for the Study of Student Citizenship, Rights and Responsibilities in Dayton

The Center for the Study of Student Citizenship, Rights and Responsibilities was established in Dayton, Ohio in October of 1970. This Center was one of the first student advocacy centers to be established in the nation, and was to assume the posture of investigating and providing answers to many problems that students and parents were being confronted with in the public school system in Dayton, Ohio. Financial support received from Legal Services Division of Research and Demonstration Programs of the United States Office of Economic Opportunity enabled the Center to function more effectively in achieving its primary task, that of informing students of their rights and responsibilities within the school system. Major objectives of this study were: (1) to identify major actors influential in the establishment of the Center and to determine major events that led up to the Center\u27s establishment; and (2) to analyze the Center\u27s initial period of operation from November 7, 1970 through. June 30, 1971, Within the general framework of these overall objectives a number of specific purposes have emerged. First, through analysis of written documents, correspondence materials , and newspaper accounts , and through use of interviews, the investigator has (1) identified and described major actors influential in the establishment of the Center, and (2) identified the major events that led up to and influenced the establishment of the Center. Second, through an analysis of grant proposal, reports, correspondence materials, demographic data and through use of interviews and on-site observations the investigator has: (1) identified procedures used in the operation of the Center and the roles of the various personnel and (2) described and analyzed major Center activities. The review of the related literature focused upon the following four topics: (1) the social upheaval in our society during the past two decades, (2) the declining organizational health of our public schools, (3) educational reform in America, and (4) literature related to students\u27 rights activities in America. Although many people were involved in the establishment of the Center, the following provided the major influence in the design and establishment of the Dayton Center: Arthur Thomas, Dr. Edgar Cahn, Mrs. Jean Camper Cahn, Dr. Ruth Burgin, Mr. Terry Lenzner, and Mr. Michael Kantor. In addition, members of two local agencies (Model Cities Planning Council and Community School Councils) assisted greatly in the establishment. In analyzing the major program thrust during the first year, the Center activities have been organized into the following categories: (1) development of inter-agency and community relationships, (2) development of dissemination materials, (3) design and implementation of ombudsmen training program, (4) description of selected case studies and potential areas of litigation, and (5) operation of a student board of inquiry into high school discipline. In summary, the following facts emerged: (1) workshops held have drawn over 1,100 people, (2) case referalls have totaled 125, with 105 parents accompanying students, (3) a written, cooperative relationship document has been developed with the administration of the Dayton Board of Education, (4) Student Rights Handbook has been developed and distributed, (5) ten parent ombudsmen have been trained to provide Center services to parents and students, (6) Center secured additional $10,000 grant from the United States Office of Education to develop a rights handbook for parents, (7) eight video tapes have been developed for training, (8) with the National Urban League, the Center secured a planning grant for an experimental school, (9) Center is working with Ohio State Legal Services to protect rights of students through analysis of pending legislation. The investigation focused primarily upon documentation and analysis of the emergence and initial year\u27s operation of the Center for the Study of Student Citizenship, Rights and Responsibilities. It is important to note that the Center is still in the embryonic stages of developing a new process the provisions of basic rights for students in Dayton, Ohio

Designing Improved Sediment Transport Visualizations

Monitoring, or more commonly, modeling of sediment transport in the coastal environment is a critical task with relevance to coastline stability, beach erosion, tracking environmental contaminants, and safety of navigation. Increased intensity and regularity of storms such as Superstorm Sandy heighten the importance of our understanding of sediment transport processes. A weakness of current modeling capabilities is the ability to easily visualize the result in an intuitive manner. Many of the available visualization software packages display only a single variable at once, usually as a two-dimensional, plan-view cross-section. With such limited display capabilities, sophisticated 3D models are undermined in both the interpretation of results and dissemination of information to the public. Here we explore a subset of existing modeling capabilities (specifically, modeling scour around man-made structures) and visualization solutions, examine their shortcomings and present a design for a 4D visualization for sediment transport studies that is based on perceptually-focused data visualization research and recent and ongoing developments in multivariate displays. Vector and scalar fields are co-displayed, yet kept independently identifiable utilizing human perception\u27s separation of color, texture, and motion. Bathymetry, sediment grain-size distribution, and forcing hydrodynamics are a subset of the variables investigated for simultaneous representation. Direct interaction with field data is tested to support rapid validation of sediment transport model results. Our goal is a tight integration of both simulated data and real world observations to support analysis and simulation of the impact of major sediment transport events such as hurricanes. We unite modeled results and field observations within a geodatabase designed as an application schema of the Arc Marine Data Model. Our real-world focus is on the Redbird Artificial Reef Site, roughly 18 nautical miles offshor- Delaware Bay, Delaware, where repeated surveys have identified active scour and bedform migration in 27 m water depth amongst the more than 900 deliberately sunken subway cars and vessels. Coincidently collected high-resolution multibeam bathymetry, backscatter, and side-scan sonar data from surface and autonomous underwater vehicle (AUV) systems along with complementary sub-bottom, grab sample, bottom imagery, and wave and current (via ADCP) datasets provide the basis for analysis. This site is particularly attractive due to overlap with the Delaware Bay Operational Forecast System (DBOFS), a model that provides historical and forecast oceanographic data that can be tested in hindcast against significant changes observed at the site during Superstorm Sandy and in predicting future changes through small-scale modeling around the individual reef objects

Responding to the Challenges and Opportunities of Workforce 2000

We report results of a national study examining the impact of demographic changes in the American workforce on small business management practices.    Telephone interviews with a national random sample of 94 small business owners explored a) if small business owners are aware of changing workforce demographics,  and b) if these small  business  owners are proactively responding to these changes by modifying their personnel practices.   Findings indicate that while small business managers are aware of changing workforce demographics, only a minority have changed their practices to take advantage of the new population available to them

Developing a cultural competence assessment tool for people in recovery from racial, ethnic and cultural backgrounds: the journey, challenges and lessons learned.

In 1997, Maryland implemented a new managed care mental health system. Consumer satisfaction, evaluation and cultural competency were considered high priorities for the new system. While standardized tools for measuring consumer satisfaction were readily available, no validated, reliable and standardized tool existed to measure the perception of people from minority groups receiving mental health services. The MHA*/MHP* Cultural Competency Advisory Group (CCAG) accepted the challenge of developing a consumer assessment tool for cultural competency. The CCAG, composed of people in recovery, clinicians and administrators used their collective knowledge and experiences to develop a 52-item tool that met standards for validity and reliability. Consultation from a researcher helped to further develop the tool into one possessing tremendous potential for statewide implementation within Maryland's Public Mental Health System. Recognizing the limitations of the study and the need for further research, this instrument is a work in progress. Strategies to improve the instrument are currently underway with the Mental Hygiene Administration's Systems Evaluation Center of the University of Maryland and several national researchers

Tunable Conductivity and Conduction Mechanism in a UV light activated electronic conductor

A tunable conductivity has been achieved by controllable substitution of a novel UV light activated electronic conductor. The transparent conducting oxide system H-doped Ca12-xMgxAl14O33 (x = 0; 0.1; 0.3; 0.5; 0.8; 1.0) presents a conductivity that is strongly dependent on the substitution level and temperature. Four-point dc-conductivity decreases with x from 0.26 S/cm (x = 0) to 0.106 S/cm (x = 1) at room temperature. At each composition the conductivity increases (reversibly with temperature) until a decomposition temperature is reached; above this value, the conductivity drops dramatically due to hydrogen recombination and loss. The observed conductivity behavior is consistent with the predictions of our first principles density functional calculations for the Mg-substituted system with x=0, 1 and 2. The Seebeck coefficient is essentially composition- and temperature-independent, the later suggesting the existence of an activated mobility associated with small polaron conduction. The optical gap measured remains constant near 2.6 eV while transparency increases with the substitution level, concomitant with a decrease in carrier content.Comment: Submitted for publicatio

Optical nulling apparatus and method for testing an optical surface

An optical nulling apparatus for testing an optical surface includes an aspheric mirror having a reflecting surface for imaging light near or onto the optical surface under test, where the aspheric mirror is configured to reduce spherical aberration of the optical surface under test. The apparatus includes a light source for emitting light toward the aspheric mirror, the light source longitudinally aligned with the aspheric mirror and the optical surface under test. The aspheric mirror is disposed between the light source and the optical surface under test, and the emitted light is reflected off the reflecting surface of the aspheric mirror and imaged near or onto the optical surface under test. An optical measuring device is disposed between the light source and the aspheric mirror, where light reflected from the optical surface under test enters the optical measuring device. An imaging mirror is disposed longitudinally between the light source and the aspheric mirror, and the imaging mirror is configured to again reflect light, which is first reflected from the reflecting surface of the aspheric mirror, onto the optical surface under test

How accurate are the non-linear chemical Fokker-Planck and chemical Langevin equations?

The chemical Fokker-Planck equation and the corresponding chemical Langevin equation are commonly used approximations of the chemical master equation. These equations are derived from an uncontrolled, second-order truncation of the Kramers-Moyal expansion of the chemical master equation and hence their accuracy remains to be clarified. We use the system-size expansion to show that chemical Fokker-Planck estimates of the mean concentrations and of the variance of the concentration fluctuations about the mean are accurate to order $\Omega^{-3/2}$ for reaction systems which do not obey detailed balance and at least accurate to order $\Omega^{-2}$ for systems obeying detailed balance, where $\Omega$ is the characteristic size of the system. Hence the chemical Fokker-Planck equation turns out to be more accurate than the linear-noise approximation of the chemical master equation (the linear Fokker-Planck equation) which leads to mean concentration estimates accurate to order $\Omega^{-1/2}$ and variance estimates accurate to order $\Omega^{-3/2}$. This higher accuracy is particularly conspicuous for chemical systems realized in small volumes such as biochemical reactions inside cells. A formula is also obtained for the approximate size of the relative errors in the concentration and variance predictions of the chemical Fokker-Planck equation, where the relative error is defined as the difference between the predictions of the chemical Fokker-Planck equation and the master equation divided by the prediction of the master equation. For dimerization and enzyme-catalyzed reactions, the errors are typically less than few percent even when the steady-state is characterized by merely few tens of molecules.Comment: 39 pages, 3 figures, accepted for publication in J. Chem. Phy