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This report presents third-year findings from an evaluation of the School Choice Scholarships Foundation Program. In 1997, this program provided scholarships via a lottery to low-income, New York City children in grades 1 through 4 that allowed them to transfer to private schools. The evaluation compared scholarship to control students, using test score, survey, and school-level data collected in the year 2000. On standardized tests, students offered scholarships performed similarly to control students. Those who ever attended private schools did not outperform those who never attended private schools. Patterns of impact for Hispanic students differed markedly from patterns for African American students in regard to test scores. Parents reported that schools and classes attended by scholarship students were smaller than those attended by public school students. Private schools were more orderly than public schools. Parents of children who switched to private schools were much more satisfied with their schools than parents of public school students. Among students offered scholarships, 53 percent used them to attend private schools for 3 full years. Parents who declined scholarships generally did so because they could not afford the added tuition and expenses. Five appendixes include research data and findings. (Contains 26 tables and 38 references.) (SM)

This report on the short-term effects of Upward Bound, a federal pre-college program designed to help economically disadvantaged students complete high school and gain access to post-secondary education, presents interim findings from the Longitudinal Effectiveness Study of Upward Bound based on data on approximately 2,800 students during the first year or two of high school. At present, there are more than 600 Upward Bound projects; they offer intensive instructional programs and are usually hosted by 2-year and 4-year colleges. The study found that: (1) Upward Bound has early positive impacts on students' educational expectations and academic course-taking; (2) students with lower educational expectations initially benefit more from Upward Bound; (3) Hispanic students initially benefit most from Upward Bound; and (4) many students (about 37 percent) who enter Upward Bound leave the program during the first year. After an executive summary and introductory chapter, Chapter 2 presents data on persistence in Upward Bound, and on the Upward Bound services offered. Chapter 3 details short-term impacts of Upward Bound, including the average impact of the program and groups benefitting most. The concluding chapter summarizes findings, compares them to previous findings, and draws implications for program improvement. Eight appendices provide additional detail on research methodology, data interpretation, and statistics. (Contains 18 references.) (DB)

This monograph presents the executive summary of a study evaluating the first-year impacts and program operations of Upward Bound, a federal pre-college program designed to help economically disadvantaged students complete high school and gain access to post-secondary education. In 1996, 45,000 students participated in the program through projects offered by 601 grantees; the average cost per student was $3,800. Most students enter Upward Bound in ninth or tenth grade and participate in a multi-year program of weekly activities during the school year and an intensive summer program that simulates college. The study found two major impacts of Upward Bound--first, participating students expect to complete more schooling than similar students not in the program and, second, the program has a positive impact on the number of academic courses participants take. Other findings included: students who benefited most initially were those with lower academic expectations; Hispanic students appeared to benefit most from the program among racial/ethnic groups examined; the program showed no impact in the first year on participants' high school grades; many students left the program in the first year; and most Upward Bound projects focused on providing a rich and challenging program. (DB)

This report investigates the practical usage of hybrid structures for rotorcraft gearing. The primary driver for utilizing hybrid structures for rotorcraft gearing is to reduce the drive system weight. The hybrid structure concept featured in this study for rotorcraft gearing consists of a metallic gear tooth-rim, a web section manufactured from composite materials, and a metallic hub. The metallic gear tooth-rim is manufactured from conventional gear steel alloys, such as AISI 9310. The gear tooth-rim attaches to the outer diameter of the web section made from composite materials. The inner diameter of the composite web can then attach to a metallic hub, completing the assembly. It is assumed that areas of the shafting or hub where rolling element bearings may ride must remain as gear steel alloys for this study.

This paper presents a replication of previous research which estimated a structural equation model relating elementary school age students' achievement to the number of parents and maternal work. The research presented here focuses on secondary school age students, and provides partial support for previous findings in which elementary school age students were analyzed. The effects of maternal work were found to be similar in both the elementary and secondary school samples (e.g., negative total effects on student's achievement in two parent families and positive total effects in one-parent, black families), but the total effect of number of parents on student's achievement for secondary school age students tended to be negligable. (Author)

This report presents the findings of a study that examined the impact of compensatory education services on children's academic achievement in grades 1 to 6. Examination of data from the 1976-79 Sustaining Effects Study of Title I revealed the following major conclusions: (1) small positive gains in reading achievement are related to participation in Title I programs; (2) the estimated impact of Title I on children's achievement is sensitive to the definition of a control group; and (3) teacher judgment may be included in the selection and achievement process. The results of the analysis do not clarify the issue examined; results are dependent upon the formulation of the control group: one formulation used in the study showed positive results of Title I on achievement while the other three used generally showed no effects. There are the following possible explanations for this inconsistency: (1) the specification of the process by which students are selected for Title I services is critical; and (2) the measurement of program participation ignores variety in the services provided and in the intensity of participation. Data are presented on seven tables and figures. Two appendices provide the technical models used. A list of references is included. (BJV)

The characteristics of schools defined as having low, medium, and high poverty concentration are examined. The following variables are examined for elementary schools: (1) school climate; (2) compensatory education related characteristics; (3) demographic characteristics; (4) student mobility; and (5) reading and math achievement. The following variables are examined for high schools: (1) school climate, specifically school misbehavior; (2) participation in Title I; (3) demographic characteristics; (4) reading and math achievement; and (5) dropout rates. Students enrolled in elementary and high schools with high concentrations of poverty are more likely to be Black or Hispanic, speak a language other than English, and have low achievement. The principals of these schools are more likely to report that student behavior is problematic than principals in low concentration of poverty schools. Students in high poverty concentration schools generally have lower achievement than those in low concentration schools even after taking into account student and family characteristics. However, achievement appears to increase at the same rate in both types of schools. Other than for students in the early grades, attending a school with a high concentration of poverty will not necessarily put a student further behind in achievement than his or her peers in low concentration schools; however, students in high concentration schools will continue to fall behind their peers in schools with relatively few students living in poverty. Data are presented on 14 tables and figures. A list of references is provided. (BJV)

The effect of changes in the achievement level of black high school students on their chances of attending postsecondary schools was assessed. Data from the High School and Beyond survey 1980 sophomore cohort were used to estimate the probability of attending two-year and four-year colleges for blacks and whites, given changes in black achievement levels. The analysis indicates that if the gap between blacks and whites was reduced by 50%, the chances of attending a postsecondary school for a black student with average achievement would increase by nine percentage points. If there was a 75% reduction in the achievement gap, black and white students would be about equally likely to attend postsecondary schools, and if the achievement gap was eliminated, there would be a higher attendance rate for blacks than for whites. Potential increases in attendance would be reflected primarily at four-year colleges, particularly at the higher achievement levels. The statistical model and procedures for calculating the impact of increasing achievement of blacks on postsecondary attendance are described. Data are included on the estimated simulated effects on college attendance as average reading and math achievement are increased for black students. (SW)

Composite materials are increasingly being considered and used for launch-vehicle structures. For shell structures, such as interstages, skirts, and shrouds, honeycomb-core sandwich composites are often selected for their structural efficiency. Therefore, it is becoming increasingly important to understand the structural response, including buckling, of sandwich composite shell structures. Additionally, small geometric imperfections can significantly influence the buckling response, including considerably reducing the buckling load, of shell structures. Thus, both the response of the theoretically perfect structure and the buckling imperfection sensitivity must be considered during the design of such structures. To address the latter, empirically derived design factors, called buckling knockdown factors (KDFs), were developed by NASA in the 1960s to account for this buckling imperfection sensitivity during design. However, most of the test-article designs used in the development of these recommendations are not relevant to modern launch-vehicle constructions and material systems, and in particular, no composite test articles were considered. Herein, a two-part study on composite sandwich shells to (1) examine the relationship between the buckling knockdown factor and the areal mass of optimized designs, and (2) to interrogate the imperfection sensitivity of those optimized designs is presented. Four structures from recent NASA launch-vehicle development activities are considered. First, designs optimized for both strength and stability were generated for each of these structures using design optimization software and a range of buckling knockdown factors; it was found that the designed areal masses varied by between 6.1% and 19.6% over knockdown factors ranging from 0.6 to 0.9. Next, the buckling imperfection sensitivity of the optimized designs is explored using nonlinear finite-element analysis and the as-measured shape of a large-scale composite cylindrical shell. When compared with the current buckling design recommendations, the results suggest that the current recommendations are overly conservative and that the development of new recommendations could reduce the acreage areal mass of many composite sandwich shell designs by between 4% and 19%, depending on the structure.

Maintains that the need for music educators to provide services for adult learners is increasing. Discusses modifying music teacher education programs to meet this need. Reviews theories of developmental education and the special needs and concerns of older learners. (CFR)

A numerical study on the effect of facesheet-core disbonds on the post-buckling response of curved honeycomb sandwich panels is presented herein. This work was conducted as part of the development of a damage tolerance approach for the next-generation Space Launch System heavy lift vehicle payload fairing. As such, the study utilized full-scale fairing barrel segments as the structure of interest. The panels were composed of carbon fiber reinforced polymer facesheets and aluminum honeycomb core. The panels were analyzed numerically using the finite element method. Facesheet and core nodes in a predetermined circular region were detached to simulate a disbond induced via low-speed impact between the outer mold line facesheet and honeycomb core. Surface-to-surface contact in the disbonded region was invoked to prevent interpenetration of the facesheet and core elements. The diameter of this disbonded region was varied and the effect of the size of the disbond on the post-buckling response was observed. A significant change in the slope of the edge load-deflection response was used to determine the onset of global buckling and corresponding buckling load.

Four honeycomb sandwich panels, representing 1/16th arc segments of a 10 m diameter barrel section of the heavy lift launch vehicle, were manufactured under the NASA Composites for Exploration program and the NASA Constellation Ares V program. Two configurations were chosen for the panels: 6-ply facesheets with 1.125 in. honeycomb core and 8-ply facesheets with 1.000 in. honeycomb core. Additionally, two separate carbon fiber/epoxy material systems were chosen for the facesheets: inautoclave IM7/977-3 and out-of-autoclave T40-800B/5320-1. Smaller 3- by 5-ft panels were cut from the 1/16th barrel sections. These panels were tested under compressive loading at the NASA Langley Research Center. Furthermore, linear eigenvalue and geometrically nonlinear finite element analyses were performed to predict the compressive response of the 3- by 5-ft panels. This manuscript summarizes the experimental and analytical modeling efforts pertaining to the panel composed of 8-ply, T40-800B/5320-1 facesheets (referred to as Panel C). To improve the robustness of the geometrically nonlinear finite element model, measured surface imperfections were included in the geometry of the model. Both the linear and nonlinear, two-dimensional (2-D) and three-dimensional (3-D), models yield good qualitative and quantitative predictions. Additionally, it was predicted correctly that the panel would fail in buckling prior to failing in strength.

Four honeycomb sandwich panels, representing 1/16th arc segments of a 10-m diameter barrel section of the Heavy Lift Launch Vehicle, were manufactured and tested under the NASA Composites for Exploration and the NASA Constellation Ares V programs. Two configurations were chosen for the panels: 6-ply facesheets with 1.125 in. honeycomb core and 8-ply facesheets with 1.0 in. honeycomb core. Additionally, two separate carbon fiber/epoxy material systems were chosen for the facesheets: in-autoclave IM7/977-3 and out-of-autoclave T40-800b/5320-1. Smaller 3 ft. by 5 ft. panels were cut from the 1/16th barrel sections and tested under compressive loading. Furthermore, linear eigenvalue and geometrically nonlinear finite element analyses were performed to predict the compressive response of each 3 ft. by 5 ft. panel. To improve the robustness of the geometrically nonlinear finite element model, measured surface imperfections were included in the geometry of the model. Both the linear and nonlinear models yielded good qualitative and quantitative predictions. Additionally, it was correctly predicted that the panel would fail in buckling prior to failing in strength. Furthermore, several imperfection studies were performed to investigate the influence of geometric imperfections, fiber angle misalignments, and three-dimensional effects on the compressive response of the panel.

Four honeycomb sandwich panels, representing 1/16th arc segments of a 10-m diameter barrel section of the heavy lift launch vehicle, were manufactured under the NASA Composites for Exploration program and the NASA Space Launch Systems program. Two configurations were chosen for the panels: 6-ply facesheets with 1.125 in. honeycomb core and 8-ply facesheets with 1.000 in. honeycomb core. Additionally, two separate carbon fiber/epoxy material systems were chosen for the facesheets: inautoclave IM7/977-3 and out-of-autoclave T40-800b/5320-1. Smaller 3.00- by 5.00-ft panels were cut from the 1/16th barrel sections. These panels were tested under compressive loading at the NASA Langley Research Center. Furthermore, linear eigenvalue and geometrically nonlinear finite element analysis was performed to predict the compressive response of the 3.00- by 5.00-ft panels. This manuscript summarizes the experimental and analytical modeling efforts pertaining to the panel composed of 8-ply, IM7/977-3 facesheets (referred to Panel A). To improve the robustness of the geometrically nonlinear finite element model, measured surface imperfections were included in the geometry of the model. Both the linear and nonlinear models yield good qualitative and quantitative predictions. Additionally, it was predicted correctly that the panel would fail in buckling prior to failing in strength. Furthermore, several imperfection studies were performed to investigate the influence of geometric imperfections, fiber misalignments, and three-dimensional (3 D) effects on the compressive response of the panel.

An innovative approach to gas turbine design involves mounting compressor and turbine blades to an outer rotating shell. Designated the exoskeletal engine, compression (preferable to tension for high-temperature ceramic materials, generally) becomes the dominant blade force. Exoskeletal engine feasibility lies in the structural and mechanical design (as opposed to cycle or aerothermodynamic design), so this study focused on the development and assessment of a structural-mechanical exoskeletal concept using the Rolls-Royce AE3007 regional airliner all-axial turbofan as a baseline. The effort was further limited to the definition of an exoskeletal high-pressure spool concept, where the major structural and thermal challenges are represented. The mass of the high-pressure spool was calculated and compared with the mass of AE3007 engine components. It was found that the exoskeletal engine rotating components can be significantly lighter than the rotating components of a conventional engine. However, bearing technology development is required, since the mass of existing bearing systems would exceed rotating machinery mass savings. It is recommended that once bearing technology is sufficiently advanced, a "clean sheet" preliminary design of an exoskeletal system be accomplished to better quantify the potential for the exoskeletal concept to deliver benefits in mass, structural efficiency, and cycle design flexibility.

A parametric weight assessment of advanced metallic panel, ceramic blanket, and ceramic tile thermal protection systems (TPS) was conducted using an implicit, one-dimensional (I-D) finite element sizing code. This sizing code contained models to account for coatings fasteners, adhesives, and strain isolation pads. Atmospheric entry heating profiles for two vehicles, the Access to Space (ATS) vehicle and a proposed Reusable Launch Vehicle (RLV), were used to ensure that the trends were not unique to a certain trajectory. Ten TPS concepts were compared for a range of applied heat loads and substructural heat capacities to identify general trends. This study found the blanket TPS concepts have the lightest weights over the majority of their applicable ranges, and current technology ceramic tiles and metallic TPS concepts have similar weights. A proposed, state-of-the-art metallic system which uses a higher temperature alloy and efficient multilayer insulation was predicted to be significantly lighter than the ceramic tile stems and approaches blanket TPS weights for higher integrated heat loads.

A tank and intertank sizing tool that includes effects of major design drivers, and which allows parametric studies to be performed, has been developed and calibrated against independent representative results. Although additional design features, such as bulkheads and field joints, are not currently included in the process, the improved level of fidelity has allowed parametric studies to be performed which have resulted in understanding of key tank and intertank design drivers, design sensitivities, and definition of preferred design spaces. The sizing results demonstrated that there were many interactions between the configuration parameters of internal/external payload, vehicle fineness ratio (half body angle), fuel arrangement (LOX-forward/LOX-aft), number of tanks, and tank shape/arrangement (number of lobes).

A parametric weight assessment of advanced metallic panel, ceramic blanket, and ceramic tile thermal protection systems (TPS) was conducted using an implicit, one-dimensional (1 -D) thermal finite element sizing code. This sizing code contained models to ac- count for coatings, fasteners, adhesives, and strain isolation pads. Atmospheric entry heating profiles for two vehicles, the Access to Space (ATS) rocket-powered single-stage-to-orbit (SSTO) vehicle and a proposed Reusable Launch Vehicle (RLV), were used to ensure that the trends were not unique to a particular trajectory. Eight TPS concepts were compared for a range of applied heat loads and substructural heat capacities to identify general trends. This study found the blanket TPS concepts have the lightest weights over the majority of their applicable ranges, and current technology ceramic tiles and metallic TPS concepts have similar weights. A proposed, state-of-the-art metallic system which uses a higher temperature alloy and efficient multilayer insulation was predicted to be significantly lighter than the ceramic tile systems and approaches blanket TPS weights for higher integrated heat loads.

Large-scale databases are an underutilized source of data for secondary analysis by researchers. Major government and private databases available to the public, the types of agencies developing them, and how to obtain and utilize them are described. A catalogue of 20 databases, their characteristics and sources is included. (BS)