Despite the multiple and diverse types of school reform to influence instruction, curriculum and fiscal policies, many urban students have low educational success and attainment. A fundamental problem of school reform is that it fails to address the economic, social, physical and cultural challenges that plague urban communities, families and children. Many urban neighborhoods are plagued by violence, crime, homelessness, property damage, poverty and other ruinous and dire circumstances. The empirical literature on neighborhood effects has described a positive relationship between neighborhood conditions and youth developmental and behavioral outcomes. However, the results vary, and there is little consensus on which neighborhood characteristics is most important. The present study examines this issue by identifying several neighborhood characteristics that influence students' college-going behaviors and beliefs, specifically their college preparation, aspirations and enrollment. This study is difference from previous research in that it incorporates ideas from place-identity theory to conceptualize the individual experiences students face in have in their neighborhoods. To conceptualize or measure concepts related to place-identity theory, I use Geographic Information Systems (GIS) to create student-level measures of neighborhood characteristics. The main data source for this study is the Philadelphia Educational Longitudinal Study (PELS), a seven-wave, longitudinal investigation of high school students and their parents. For this study, PELS is utilized to describe students' background characteristics, educational aspirations, and academic engagement and to link students to school data. In addition, census and geographic data are used to measure neighborhood disadvantage and students' spatial relationship to neighborhood liquor and beer stores and drug crimes. Consistent with findings from other neighborhood effects studies, the results from this study are mixed. Specifically, the findings reveal that the presence of some types of liquor stores and indicators of neighborhood disadvantage predict students' college-related indicators. The finding also indicate the individual-level neighborhood characteristics, that is the neighborhood features encountered the events experienced and those things seen by students, are important. Overall, I conclude from this study that student' experiences outside of school matter. Furthermore, this research suggests that future neighborhood research should utilize theories that directly hone in on individual perspectives and development, rather than focus on macro theories that solely focus on neighborhood processes, relationship and aggregate characteristics. Furthermore, future studies should incorporate GIS technologies and spatial analyses. Finally, I recommend that school reform measures to alleviate educational gaps and shortfalls should not only focus on the schooling environment, but also should incorporate broader policies to directly confront urban neighborhood disadvantage and family challenges. / Urban Education

The major source of aircraft noise at take-off is jet noise. If jet noise is not adequately addressed environmental impact concerns will constrain the planned growth of the air transport system. A considerable amount of research worldwide has therefore been aimed at identifying ways to reduce jet noise including development of a predictive tool that can estimate the noise generated by new nozzle designs. Current noise prediction techniques, however, still require the input of empirically calibrated noise source models and their performance is still inadequate. In addition, development of detailed noise source identification measurements and the associated understanding of how to control (and reduce) the noise at the source has been limited. The fundamental turbulence property which acts as the source of propagating noise in shear layers is the two-point space-time velocity correlation (Rijkl). Very few measurements exist for this property to guide model development. It is therefore the aim of the work reported in this thesis to provide new experimental data that helps identify the turbulence sources located within the shear layer of jets. The technique of Partical Imaging Velocimetry (PIV) is used to capture directly the flowfield and all relevant turbulent statistics.

Historic geopolitics as method of spatial analysis allows the understanding of the internal relationships of time, space and society; explaining the socio-spatial transformations of the agrarian systems where there is the intervention of the physical environment, society and its economy within a given territory.Through these referees it is proposed to develop an historic characterization of the agrarian systems of the haciendas in the high basin of Río Lerma, State of México. Here I intend to explain the agrarian system functioning, the types of territorial production systems, crop systems, husbandry and agro forestry, the reproduction of agro economic systems and the technological management of the intervening resources in the agricultural production. In this way we offer substantive elements that allow understanding the historic evolution of the agrarian systems in the study basin, in order to take it in account when doing its future territorial planning. / La geografía histórica como método del análisis espacial permite el conocimiento de las relaciones entre tiempo, espacio y sociedad, explicando las transformaciones socioespaciales de los sistemas agrarios en los que intervienen el medio físico, la sociedad y su economía en un determinado territorio.A través de estos referentes se pretende desarrollar una caracterización histórica de los sistemas agrarios de las haciendas en la cuenca alta del río Lerma, estado de México, para explicar el funcionamiento del sistema agrario, los tipos de sistemas de producción territorial, sistemas de cultivo, ganadero y agroforestales, la reproducción de sistemas agroeconómicos y el manejo tecnológico de los recursos involucrados en la producción agrícola. De esta forma ofrecemos elementos sustantivos que permitan entender la evolución histórica de los sistemas agrarios en la cuenca de estudio, para su consideración en la mejor interpretación de su problemática presente y planeación territorial futura.