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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Air Surveillance for Smart Landing Facilities in the Small Aircraft Transportation System

Shea, Eric Joseph 25 April 2002 (has links)
The Small Aircraft Transportation System (SATS) is a partnership among various organizations including NASA, the FAA, US aviation industry, state and local aviation officials, and universities. The program objectives are intend to reduce travel times by providing high-speed, safe travel alternatives by making use of small aircraft and underused small airports throughout the nation. A major component of the SATS program is the Smart Landing Facility (SLF). The SLF is a small airport that has been upgraded to handle SATS traffic. One of the services needed at SLFs is air surveillance of the airspace surrounding it. This thesis researches the different surveillance techniques available for use at the SLFs. The main focuses of this paper are an evaluation of the Traffic Alert and Collision Avoidance System (TCAS) when used as a ground sensor at SLFs and the design of a Position and Identification Reporting Beacon (PIRB). The use of the TCAS ground sensor is modeled in Matlab and the results of that model are discussed. The PIRB is a new system that can be used in conjunction with the Automatic Dependent Surveillance-Broadcast (ADS-B) system or independently to provide position information for all aircraft using GPS based positioning. / Master of Science
2

[en] STUDY OF URANIUM COMPOUNDS SOLUBILITY IN THE NUCLEAR FUEL CYCLE IN LPS / [pt] ESTUDO DA SOLUBILIDADE DE COMPOSTOS DE URÂNIO DO CICLO DO COMBUSTÍVEL EM LPS

CINTIA MONTEIRO DE LIMA 01 September 2008 (has links)
[pt] O ciclo do combustível nuclear é o conjunto de etapas do processo industrial que transforma o mineral urânio até sua utilização como combustível nuclear. Em todas as etapas do ciclo os trabalhadores estão expostos a partículas contendo urânio. Para avaliar os riscos é necessário conhecer a taxa de deposição, a concentração e a cinética da partícula no trato respiratório. Os testes de solubilidade in vitro, permitem um estudo sistemático da solubilidade de qualquer composto. Nesse estudo foram utilizadas amostras de DUA, TCAU e UO2 em contato com o liquido pulmonar simulado e estas foram analisadas pela técnica de PIXE (Particle Induced X rays Emission) para determinação da fração de urânio solubilizada e pela técnica de 252 Cf-PDMS (Plasma Desorption Mass Spectrometry) para a determinação da especiação química. Os objetivos específicos foram: (i) Identificar os compostos de urânio na fração respirável do aerossol nas etapas selecionadas do ciclo de combustível nuclear; (ii) identificar e determinar a solubilidade dos compostos de urânio em líquido pulmonar simulado; (iii) Determinar os parâmetros de solubilidade dos compostos de urânio. Os valores dos parâmetros de solubilidade determinados neste estudo para o DUA, TCAU e UO2 são: fr, = 0,83; sr = 0,51 d -1 e ss = 0,0075 d -1 ; fr = 0,60; sr = 0,70 d -1 e ss = 0,00089 d -1 e fr = 0,19; sr = 0,47 d -1 e ss = 0,0019 d -1 , respectivamente. / [en] The nuclear fuel cycle is the industrial process that converts the uranium ore, to its use as fuel, inside of a nuclear power station. In all steps from the nuclear cycle workers are exposure to uranium dust particles. To evaluate the risk due particles incorporation data like deposition, concentration and kinetics of the particles in the respiratory tract must be know The in vitro solubility test allows a systemic understanding about the compound solubility. Samples of DUA, TCAU e UO2 and SLF was collected in different time interval and the uranium concentration was determined by PIXE (Particle Induced X rays Emissions) technique and the uranium compounds were identified by 252 Cf-PDMS (Plasma Desorption Mass Spectrometry). The specific objectives were: (i) identifying uranium compounds in the respirable fractions of aerosol (ii) identified and determinated the uranium coumpounds solubility in simulated lung fluid (iii) determinated the solubility parameters to this uranium compounds. The solubility parameters to DUA, TCAU and UO2 are: fr, = 0,83; sr = 0,51 d -1 and ss = 0,0075 d -1; fr = 0,60; sr = 0,70 d -1 and ss = 0,00089 d -1 e fr = 0,19; sr = 0,47 d -1 e ss = 0,0019 d -1, respectively.
3

Self-Incompatibility in African Lycium (Solanaceae)

Feliciano, Natalie M 01 January 2008 (has links) (PDF)
Chapter one of my thesis has been published in the May 2008 issue of the journal Evolution under the title “A TALE OF TWO CONTINENTS: BAKER’S RULE AND THE MAINTENANCE OF SELF-INCOMPATIBILITY IN LYCIUM (SOLANACEAE).” This chapter was co-authored by Dr. Jill S. Miller and Dr. Rachel Levin.
4

Automated Traffic Control for Smart Landing Facilities

Florin, Charles Henri 30 December 2002 (has links)
The Small Aircraft Transportation System (SATS) is a partnership between the FAA, the NASA, US aviation companies, universities and state and local aviation officials. The purpose of SATS is to develop a system to handle future increase in Air Traffic, reduce time-travel, develop automation in Air Traffic Control (ATC) and make better use of small aircraft and underused airports. The Smart Landing Facility (SLF) is an important part of the program. The SLF is a small airport upgraded with equipment to support SATS aircraft. Among the SLF equipment, SATS needs new detection equipment, and eventually automation. This thesis investigates different techniques to avoid data collision in aircraft radar responses, and to reduce delays between landings and take offs. First, the paper shows how and when the radar receiver can separate two overlapped radar responses. Second, to avoid transponders responses overlapping, requirements in terms of aircraft safety distance are computed, different conflicts in air traffic around the SLF are examined and a solution is proposed for each case. And finally, the thesis investigates how far SATS can go in developing an automatic ATC system and what the role of future human operator will be in ATC. / Master of Science
5

Separated Local Field NMR Spectroscopy In Partially Ordered Systems - New Methodologies And Applications

Das, Bibhuti Bibhudutta 04 1900 (has links)
Dipolar couplings are one of the major source of structural information. Due to their dependence on the distance between the nuclei and the angle of orientation of the dipolar vector with respect to the magnetic field, they provide significant insight into the geometry and topology of molecules. As the dipolar interactions are in general present in the solid phase of the compounds, solid state NMR experiments have gained significant popularity and is widely used. Separated Local Field NMR spectroscopy based on cross-polarization technique has been used to measure the heteronuclear dipolar couplings in solid state. However, the technique undergoes many experimental challenges and requires further development. This thesis is concerned mainly with the development of techniques to measure the dipolar couplings accurately in oriented molecules. In this regard, a method for fast data acquisition is also proposed. The first chapter briefly introduces the basics of NMR spectroscopy, methodologies applied for obtaining a high resolution NMR spectrum in the solid state. An introduction to liquid crystals is presented and the nature of NMR interaction in the liquid crystalline phases is described. In chapter-2, a new pulse scheme has been proposed that includes the X-nucleus polarization in the SLF experiments and is shown to provide better sensitivity and resolution. A quantitative analysis with simulation and experimental results are also presented. In chapter-3, the performance of various homonuclear decoupling pulse schemes incorporated into SLF experiments tested on oriented systems are compared. The proposed pulse schemes are shown to provide high resolution spectrum with accurate dipolar coupling measurement for natural abundant samples and for uniformly labeled compounds as well. Theoretical description with simulation and experimental results shown here are found to provide optimum results under several technical complications seen with respect to the conventional methods used for SLF experiments. Chapter-4, an attempt is made to reconstruct 2D J-resolved and 2D- SLF spectra from several 1D experimental data. This is achieved with the help of projection reconstruction method and is shown to provide high resolution 2D spectrum with saving of experimental time by an order of two. Chapter-5, high resolution spectra from SLF experiments under phase alternating pulses and using amplitude and time averaged nutation techniques are shown for accurate dipolar coupling measurement with a dramatic reduction in rf power. This is important as the use of low rf power leads to low sample heating and can be applied suitably for the study of liquid crystals and salty biomolecules. Chapter-6, attempts are made to characterize two novel thiophene based liquid crystals using both solution and solid state NMR spectroscopy. C-H dipolar couplings measured from SLF experiments are mainly used to find the order parameters and geometry of the molecules.
6

Determinants of Rural Household Food Security in Drought-Prone Areas of Ethiopia: Case study in Lay Gaint District, Amhara Region

Berlie, Arega Bazezew 21 January 2015 (has links)
This study examines rural household food security and its determinants in drought-prone Amhara Region of Ethiopia by focusing on Lay Gaint district as a case study site. A range of factors from physical environmental circumstances to policy and institutions-related issues determine households‟ vulnerability to food insecurity and livelihood outcomes. The survey results showed that the majority (74%) of the sampled households experienced food insecurity. The situation was worse among female-headed households such that 86% of them were food insecure. The study revealed that, despite the low level of productivity related to local environmental constraints, rural livelihoods remain undiversified with small scale rain-fed agriculture to provide the primary source of livelihood for the large majority of households (~93% of respondents). Only about 25% of the respondents participated in some form of non-farm or off-farm activities, but with only little contribution to their total annual incomes. Food insecurity is a chronic problem in that, on average, households in the study area consume from own production for only about six months. The study found out that the majority of households (about 80%) perceived annual rainfall to be inadequate to support the growing of crops and grazing of animals. The main adaptive strategies employed by the majority of households included diversifying livestock kept, planting trees and diversifying crops. The study revealed that incidence, depth and severity of food insecurity of the food insecure households showed that Woina-Dega and Kolla agro-ecologies are prone to vulnerability to food insecurity. This suggests that development interventions that are geographically differentiated; and build household assets will improve household food security in the study area, and in other similar environments in the country. / Geography
7

Determinants of Rural Household Food Security in Drought-Prone Areas of Ethiopia: Case study in Lay Gaint District, Amhara Region

Berlie, Arega Bazezew 21 January 2015 (has links)
This study examines rural household food security and its determinants in drought-prone Amhara Region of Ethiopia by focusing on Lay Gaint district as a case study site. A range of factors from physical environmental circumstances to policy and institutions-related issues determine households‟ vulnerability to food insecurity and livelihood outcomes. The survey results showed that the majority (74%) of the sampled households experienced food insecurity. The situation was worse among female-headed households such that 86% of them were food insecure. The study revealed that, despite the low level of productivity related to local environmental constraints, rural livelihoods remain undiversified with small scale rain-fed agriculture to provide the primary source of livelihood for the large majority of households (~93% of respondents). Only about 25% of the respondents participated in some form of non-farm or off-farm activities, but with only little contribution to their total annual incomes. Food insecurity is a chronic problem in that, on average, households in the study area consume from own production for only about six months. The study found out that the majority of households (about 80%) perceived annual rainfall to be inadequate to support the growing of crops and grazing of animals. The main adaptive strategies employed by the majority of households included diversifying livestock kept, planting trees and diversifying crops. The study revealed that incidence, depth and severity of food insecurity of the food insecure households showed that Woina-Dega and Kolla agro-ecologies are prone to vulnerability to food insecurity. This suggests that development interventions that are geographically differentiated; and build household assets will improve household food security in the study area, and in other similar environments in the country. / Geography
8

Results Measurement of Livelihood Interventions in the Humanitarian Field, using a Sustainable Livelihoods Framework (SLF) to analyze the Economic Rate of Return (ERR) of an income-generating activity (IGA) project in a post-disaster setting, in San Andres Osuna, Guatemala

Hörmander, Olof January 2023 (has links)
There is limited evidence-based data on income-generating interventions, both within thehumanitarian and the development field. Nevertheless, there is a growing and unavoidable nexus between the two fields, and therefore also, within their methodologies for measuring project intervention results, as well as their success rates. The challenge in many cases,however, is finding a measuring system which does not only account for a project’s expenditures, but can also tell something about a project’s effectiveness, which can then be compared to similar intervention’s results, and applied in future endeavors. Hence, this study analyzes the economic effectiveness of an Income Generating Activity (IGA) project in rural Guatemala as a case study, using an Economic Rate of Return (ERR) as the basis of measurement, which is acquired using a cost-benefit analysis (CBA). The study draws on the various viewpoints of scholars on the subject, taking into account different Monitoring and Evaluation (M & E) practices, particularly in the manners carried out by the United Nations and the World Bank, as they have long histories of M & E practices in the field. It especially lays emphasis on the Sustainable Livelihoods Framework (SLF), which is a tool which is often used within humanitarian work as well as in development to determine possible economic opportunities in communities. Although the study aims at IGA programs in the humanitarian sector, data within development projects is also explored in this thesis, because longer timeframes within development, allow for more careful study of long-term results, which is usually a requirement for the evaluation of livelihood. Results within the development sector allow for more careful study of results, and more certain conclusions than within the humanitarian sector, which due to its emergency settings, usually has a more difficult time collecting data.This study then makes an ex-ante analysis of the case study in question, which is a potential aquaponic fish tank project, with economic benefits, in the unattended, post-disaster settings of San Andrés Osuna, Guatemala, following the eruption of the Volcan de Fuego, in 2018. The study reveals that the project has a potential ERR of 280 percent, compared to other WorldBank projects which tend to have an ERR ranging between 15 and 25 percent. Nevertheless, other projects which have also been explored by this study, also offer results ranging ERRs of about 280 percent as well. Many times, projects utilize cost-efficiency analysis which make them more difficult tocompare and contrast to other projects than if they had used ERR results, to measure the projects’ success. This comparison of projects can help decision makers better allocate their resources to the most efficient income generating projects in the future, which can therefore better economic livelihoods of people in post-disaster settings. The World Bank has used this ERR as an indicator for their cost-benefit analyses for the past 70 years, but is increasingly utilizing it less and less, whilst other humanitarian and financial organizations, do not use it at all; making this a possible issue within the field.
9

Resettlement and sustainable livelihoods in Ethiopia : a comparative analysis of Amhara and southern regions

Kassa Teshager Alemu 02 1900 (has links)
Resettlement as a development discourse has become a worldwide phenomenon. This phenomenon is mainly caused by population pressure, war or prolonged hostilities between countries or groups within the country, irreversible environmental degradation and development projects. While there are diverse causes of resettlement situations, this study focused on state sponsored resettlement programmes caused by socio-economic, political and environmental problems in Amhara and the southern regions of Ethiopia. The main objective of this empirical study was to analyse the effects of planned government intra-regional resettlement programme on the sustainable livelihoods of resettled households in Ethiopia. The central research question was: Does a planned intra-regional resettlement programme provide sustainable livelihoods for settler households in the two selected regions of Ethiopia? If it does, what chain of factors explains the livelihood security and sustainability? If it does not, what are the interacting variables and how have they generated a process of livelihood insecurity? To this end, the combination of Sustainable Livelihood Framework (SLF) and Impoverishment Risks and Reconstruction (IRR) models were used as the pillars of the theoretical and conceptual framework of the study. Mixed method design that combines both quantitative and qualitative data from primary and secondary sources were used in this study. Primary data were collected through a household survey, key informants interview, focus group discussion and field observation. A total of 250 households were surveyed and a total of 28 interviewees were contacted from the two regions. A total of 6 focus group discussions were also conducted with purposively selected participants. This study concludes that the effects of planned resettlement on the sustainable livelihoods of resettlers were mixed and challenged the generic representation of the scheme as a success or a failure. The adverse effects were mainly due to policy gaps, the mismatch between policy and practice, poor inter-sectoral and inter-regional integration and inadequate capacity building efforts. Recommendations were provided in line with these gaps. In addition, the knowledge documented through the application of SLF and IRR in mixed method design contributed to the methodological and theoretical advancement of resettlement and livelihood studies. / Development Studies / D. Litt. et Phil. (Development Studies)
10

Subjektellipsen in Koordinationsstrukturen. Theoretische Fundierung und empirische Erkenntnisse / Subjektlücken in Koordinationsstrukturen. Theoretische und empirische Untersuchungen der SLF-Koordination / Subject Ellipsis in Coordinative Structures. Theoretical foundation and empirical evidence / Subject Gaps in Coordinative Structures. An theoretical an empirical study of the SGF-coordination

Bonitz, Petra-Kristin 12 May 2014 (has links)
Subjektlücken in Koordinationsstrukturen sind nicht leicht zu analysieren, insbesondere Subjektlücken in Asymmetrischen Koordinationen wie die SLF-Koordination (Subjektlücken in finit-frontalen Strukturen). Die Dissertation gibt eine umfassende Übersicht über verschiedene linguistische Analysen solcher Strukturen. Desweiteren präsentiert die Arbeit empirische Daten zur SLF-Koordination, zur Asymmetrischen sowie auch zur Symmetrischen Koordination. Es konnte eine breite empirische Datengrundlage geschaffen werden, indem Akzeptabilitätsurteile über Online-Fragebogen gesammelt wurden, wobei die psycholinguistische Methode Magnitude Estimation Anwendung fand. Die Dissertation ist relevant für die deskriptive Grammatik, für psycholinguistische Fragestellungen und linguistische Analysen zu Subjektlücken in Koordinationsstrukturen.

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