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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.
421

Appropriate energy design guidelines for new desert housing in Egypt: "A case study for cluster houses at Sadat City".

Chalfoun, Nader Victor. January 1989 (has links)
The tremendous increase of population in Egypt has caused the Egyptian government to rethink its settlement policy by planning for the development of new desert communities in remote arid regions outside of the Nile Valley. Presented here is a methodology for generating appropriate energy design guidelines for desert housing in these new communities. The methodology also takes into account the culture, climate and economy of the country. This interdisciplinary study starts by examining the current government national policy for regional and urban development in Egypt with emphasis on the new desert settlement programs in general and on the Sadat City in particular. The criteria which determines human thermal comfort requirements for the indigenous people of Egypt is then presented. This part of the study also includes a climatic analysis of Egypt showing the major climatic components, the factors modifying the climate, the country's major climatic zones, and microclimatic considerations. In the next chapter on energy analysis, the concepts and the mathematical basis of the methodology are presented. The process is based on balancing the incremental cost/benefit of conservation and passive solar designs in an optimum mix yielding the best performance and economic advantages for any given set of weather characteristics. Finally, the method is generalized and reduced to a set of formulas which generate energy guidelines for conservation levels with selected passive solar system(s). A computer model of the method is developed and energy guidelines for six major locations in Egypt are illustrated. In conclusion, a preliminary design for low-energy cluster houses at the new desert community Sadat City is developed using the computer generated guidelines for that region. The energy results are then validated using the CalPas3 energy simulation program, and a matrix is also developed for assessing the socio-cultural aspects of the design model.
422

Soil, water, and man in the desert habitat of the Hohokam culture: an experimental study in environmental anthropology

El-Zur, Arieh,1914- January 1965 (has links)
The proposition that environment is of equal importance to time and space in the study of culture suggests that a three-dimensional approach may be a useful method for studying the process of cultural evolution. This possibility is tested by detailed investigations into the history and natural habitat of the prehistoric Hohokam Culture. This culture developed an extensive system of irrigation agriculture in the Gila River valley of southern Arizona about A. D. 1-1400. The study is carried out on the processual as well as analytical level of enquiry whereby primary attention was given to the relationship between environment and culture. This emphasis is particularly relevant in the case of the arid conditions of the region in which the Hohokani Culture developed. The interaction of the primary environmental agents, water and soil, and the cultural agent, prehistoric man, is delineated in terms of the natural processes of soil development and movement of water in the region as well as the cultural process of irrigation agriculture. During all phases of the River liohokarn Culture the relationship between soil, water, and man was interdependent and their functional interaction was exposed to the forces of the active environment, which may have become critical. An attempt is made to arrive at an interpretation along these lines for the terminal period of the Hohokam Culture at Snaketown, a major prehistoric site near Chandler, Arizona. While no definite conclusions are derived, the evidence, presented by means of inferential analysis, points strongly towards environmental causation. The impact of the prevailing climatic conditions at the end of the 13th century may have upset the precarious balance between water and soil and thus the livelihood of the desert dwellers. These events led inevitably to the termination of the Hohokam Culture.
423

Papago fields : arid lands ethnobotany and agricultural ecology

Nabhan, Gary Paul January 1983 (has links)
Papago Indian fields located in southern Arizona and northern Sonora, Mexico are examples of a food production strategy that was developed within the constraints of a water-limited environment. Although only a small percentage of the fields cultivated at the turn of the century remain in cultivation, extant fields are vestiges of an agricultural tradition that has persisted in arid lands for centuries. An examination of the documentary history of non-Indian observations of Papago agriculture and water control from 1697 to 1934 reveals numerous practices and features that are no longer apparent within or around remaining fields. Yet by learning from oral historical accounts of elderly Papago, and analyzing O'odham lexemes (native Papago terms) which guide farmers' management of fields, it is possible to gain a sense of folk science which Papago developed to successfully farm without permanent surface water reserves. Selected concepts from the folk science of the Papago are used as a point of departure in understanding the ecological processes which function within their fields. Standard field ecology methods were adapted to empirically test certain hypotheses relating to these ecological processes. Results include confirmation that Papago fields are situated in a variety of physiographic positions, and that ‘ak-ciñ arroyo mouth' farming is a misnomer. Papago crops exhibit many of the same drought-escaping adaptations as wild summer desert ephemerals for seed production during the brief summer rainy season, which varies from year to year in the date of its initiation. These adaptations greatly contribute to crop success. There are no significant differences in the diversity of herbaceous plants found in Papago fields compared to the diversity found in adjacent, uncultivated environments. Of the many nutrients analyzed in cultivated and uncultivated floodplain soils, only potassium was significantly richer in fields than in uncultivated floodplains; other differences were statistically insignificant. Floodwashed organic detritus, rather than the floodwaters themselves, appear to play the major role in renewing field soil fertility in certain localities. It is concluded that indigenous concepts which have long guided the management of traditional agricultural systems are of heuristic value in understanding how these farming systems function ecologically.
424

The phylogeny and water relations of pinyon pines in relation to the vicariance biogeography of the American southwest

Malusa, James Rudolph. January 1989 (has links)
Axelrod (1958) suggested that the late Tertiary shift in regional climate -- the elimination of summer rains -- had a profound influence on the evolution of biotic provinces in the American southwest. In particular, the taxa endemic to biotic provinces characterized by summer drought, e.g., the Mojave Desert, should be derived from ancestors that likely inhabited regions of summer rain, e.g., the Chihuahuan Desert. Further, the derived features of summer-drought taxa should be related to water stress. I examined Axelrod's thesis, using a combination of phylogenetic systematics, physiological ecology, and vicariance biogeography. The first chapter is a cladistic study of the pinyon pines, 13 taxa of small trees that range from the summer-wet regions of Mexico to the summer drought regions of Nevada and California. A parsimony analysis using twenty morphological characters showed that the most recently derived pinyons are from regions of summer drought. The "summer-drought" taxa are characterized by relatively few needles per fascicle. Because fewer needles per fascicle results in a reduction in the needle surface-to-volume ratio, Haller (1965) hypothesized that fewer needles in pines is an adaptation to reduce transpirational water loss. The second chapter reports on a two year study of the xylem pressure potentials of single- and double-needled fascicles of hybrid pinyons in central Arizona. The results showed no significant differences between single- and double-needles. I concluded that either needle morphology does not effect water relations, or that the relatively high precipitation during the study did not allow significant water stress to occur. The third chapter uses the methods of vicariance biogeography to search for a common pattern of relationship between southwestern biotic provinces, as indicated by the relationships of their endemic taxa. Using a biogeographic parsimony analysis, I compared the area cladograms of six taxa -- junipers, pinyon pines, the composite Palafoxia, hedgehog cactus, desert tortoises, and gecko lizards. The most parsimonious area cladogram supports Axelrod's (1958) hypothesis, but also shows that some taxa, notably the junipers, support other patterns of area relationships, e.g., summer-drought primitive. I suggest that there is no single pattern of area relationships because of the effects of the Pleistocene (including dispersal and extinction) and vicariance events other than the Tertiary climatic change, e.g., the separation of the Baja peninsula from mainland Mexico during the Miocene.
425

The Impact of Groundwater Development in Arid Lands: A Literature Review and Annotated Bibliography

Keith, Susan Jo January 1977 (has links)
No description available.
426

A Study to Explore the Use of Orbital Remote Sensing to Determine Native Arid Plant Distribution

McGinnies, W. G., Haase, E. F., Lepley, L. K., Conn, J. S., Musick, H. B., Foster, K. E. 08 1900 (has links)
"Last biannual progress report and final report describing work under NASA contract no. NAS5-21812."
427

The effect of moisture stress and salinity on germination and growth of grain amaranth Amaranthus cruentus L and Amaranthus hypochondriacus L

Reed, Mickey Lynn, 1952- January 1988 (has links)
The grain amaranths, Amaranthus cruentus and Amaranthus hypochondriacus have been promoted as grain-bearing plants of possible high productivity in saline or hot arid habitats. To investigate these claims, seeds of both species were germinated at 10, 15, 20, 25, 30, 35 and 40°centigrade. Germination percentage for both species was above 90% after four days at 20, 25, 30, and 35°C. Germination was negligible at 10 and 15°C and very low at 40°C. Seeds were germinated in isotonic solutions of PEG and NaCl at 0.0, -0.2, -0.4, -0.5, -0.6, -0.8, and -1.0 MPa osmotic potential at 30°C. Germination percentage was high in the range 0.0 to -0.4 MPa and dropped rapidly to zero in the -0.6 to -1.0 MPa range. Differences due to chemical effects were significant. Species differences were not. Radicles and hypocotyls were measured after six days in the above media. PEG was more inhibitory of seedling growth than was NaCl and generally inhibited A. cruentus more than A. hypochondriacus. This was also true of NaCl. All growth functions were slightly inhibited at 0.0 to -0.4 MPa and very inhibited above -0.6 MPa. PEG radically increased root/shoot ratio in both species.
428

The performance of selected small grain cultivars under an irrigation gradient

Ashley, Roger Orrin, 1953- January 1989 (has links)
Differential adaptations of barley (Hordeum vulgare L.) and wheat (Triticum spp.) genotypes suggest that they be evaluated under multi-environmental conditions. The objectives of this study were to determine if small grain genotypes, bred for various moisture conditions, respond differently in terms of yield, water use, and rooting pattern to contrasting moisture conditions. Eight small grain genotypes were compared under a gradient of water from 89 to 404 mm (plus 254 mm of stored water) in a field study at Marana, AZ. A barley bred for low input conditions had greater root density in the subsoil and used moisture earlier in the season when compared to a high input barley (WestBred Gustoe). The cultivars bred for high input conditions required more water for optimum yield compared to those bred for low input conditions.
429

Regionų unikalumo ekonominis vertinimas Europos integracijos procesų kontekste / Economic assessment of regional uniqueness in the context of European integration processes

Gedminaitė-Raudonė, Živilė 16 June 2014 (has links)
Disertacijoje vertinamos regiono unikalių išteklių panaudojimo galimybės regiono ekonominei socialinei raidai gerinti, įgyvendinant Europos Sąjungos regioninę politiką. Pagrindinis tyrimo objektas yra regioninės politikos sprendimų rengimo ir pagrindimo procesai, reikalaujantys adekvataus regionų unikalumo vertinimo, tame tarpe siekiant efektyviai panaudoti unikalius išteklius regiono socialinei ekonominei raidai. Pagrindinis disertacijos tikslas – sukurti teorinę koncepciją, skirtą kompleksiniams regionų unikalumo ekonominiams vertinimams bei parengti regionų unikalumo ekonominio vertinimo instrumentarijų, panaudotiną regioninės politikos sprendimams. Sukurto instrumentarijaus taikymo sritis – Europos Sąjungos ir nacionalinės regioninės politikos įgyvendinimas. / The dissertation investigates the issues of regional development and region possibilities to increase value added by using unique resources of the regions in the context of EU integration processes. The main object of research is regional policy decision-making processes requiring adequate economic assessment of regional uniqueness aiming effective use of unique resources of the region for social and economic development. This object is important not only to the state or regional level but also at the EU level with the aim to exploit regions basic skills and resources that can be unique from the perspective of other regions and to use competitive advantage. The primary purpose of this dissertation is building the theoretical concept that would serve as a base for the methodology creation of complex economic assessment of regional uniqueness that in the next stage would serve as an instrument for the implementation of EU regional policy.
430

Mutual Information Based Methods to Localize Image Registration

Wilkie, Kathleen P. January 2005 (has links)
Modern medicine has become reliant on medical imaging. Multiple modalities, e. g. magnetic resonance imaging (MRI), computed tomography (CT), etc. , are used to provide as much information about the patient as possible. The problem of geometrically aligning the resulting images is called image registration. Mutual information, an information theoretic similarity measure, allows for automated intermodal image registration algorithms. <br /><br /> In applications such as cancer therapy, diagnosticians are more concerned with the alignment of images over a region of interest such as a cancerous lesion, than over an entire image set. Attempts to register only the regions of interest, defined manually by diagnosticians, fail due to inaccurate mutual information estimation over the region of overlap of these small regions. <br /><br /> This thesis examines the region of union as an alternative to the region of overlap. We demonstrate that the region of union improves the accuracy and reliability of mutual information estimation over small regions. <br /><br /> We also present two new mutual information based similarity measures which allow for localized image registration by combining local and global image information. The new similarity measures are based on convex combinations of the information contained in the regions of interest and the information contained in the global images. <br /><br /> Preliminary results indicate that the proposed similarity measures are capable of localizing image registration. Experiments using medical images from computer tomography and positron emission tomography demonstrate the initial success of these measures. <br /><br /> Finally, in other applications, auto-detection of regions of interest may prove useful and would allow for fully automated localized image registration. We examine methods to automatically detect potential regions of interest based on local activity level and present some encouraging results.

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