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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

Inheritance effects in the weathering of debris under hot arid conditions

Warke, Patricia A. January 1994 (has links)
No description available.
2

Structural Evolution of the Virgin Spring Phase of the Amargosa Chaos, Death Valley, California, USA

Castonguay, Samuel 10 October 2013 (has links)
The Amargosa Chaos and Fault of Death Valley are complex features that play important roles in various tectonic models. Some recent models claim the fault is a regional detachment accommodating 80 km of NW-directed transport that produced the Chaos in its hangingwall. I offer an alternative interpretation: the chaos is a product of multiphase deformation that likely spanned the late Mesozoic and Cenozoic. The Amargosa Fault represents just one of six deformation events. The accompanying map (supplemental file) shows the cross-cutting relationships among fault populations: (D1) 25% north-northwest directed shortening across an imbricate thrust and tight fold system; (D2) E-SE extension on five normal faults; (D3) extension-related folding, which folded the D2 faults; (D4) normal-oblique slip on the Amargosa Fault; (D5) E-W extension on domino faults; (D6) extension on the Black Mountains Frontal Fault. The D2 faults, not the Amargosa, created the enigmatic attenuation observed in the Chaos.
3

Chefers uppfattning och hantering av Death Valley vid organisationsförändring

Tesfamichael, Aron, Ferati, Alban January 2017 (has links)
Organisationsförändringar sker kontinuerligt och chefer måste beakta mycket vid genomförandet av förändring. En viktig faktor är individerna, chefer måste förstå medarbetare och deras reaktioner till förändringen för att den ska fungera. Death Valley är ett fenomen som kommer från psykologin, men som används flitigt i organisationsteori. Begreppet beskriver en känslomässig reaktionär process som leder till en tillfällig nedgång i individers prestation. Det är en del av individers förändringsprocess, som de genomgår under organisationsförändring. Hanteringen av Death Valley är av största vikt för chefer, då individer som befinner sig i Death Valley till viss del förlorar förmågan att utföra sitt arbete. Mycket teori finns kring hur individer tar sig igenom denna fas samt vilka känslor som upplevs under denna fas. Det saknas dock empiriskt stöd, främst kring hur chefer hanterar fenomenet samt hur chefer upplever det. Denna studie ämnar nu tillföra detta. Studien utgår ifrån en fenomenologisk ansats och ostrukturerade intervjuer används som metod. Resultatet har visat att chefers hantering av Death Valley främst sker genom kommunikation samt involvering. Cheferna uppfattar fenomenet som en fas där individer främst är frustrerade, osäkra samt uppgivna. Slutsatsen visar på att studien främst har skapat en större förståelse för hur fenomenet upplevs och hanteras bland chefer i en pågående organisationsförändring. / Organizational change happens continuously and managers must take into account much in the implementation of change. An important factor are the individuals, managers need to understand people and their reactions towards the change in able to make the change work. Death Valley is a phenomenon that comes from psychology, but is used extensively in organizational theory. It describes an emotional reactionary process leading to a temporary decline in individuals' performance. It is part of an individual's change process, which they undergo during organizational change. The ability to manage Death Valley is crucial for managers, as individuals who are in Death Valley cannot perform their work in a satisfactory manner. A vast amount of theory is available describing how people get through this phase, as well as the emotions experienced during this phase. However, there is a lack of empirical evidence, mainly around how managers handle the phenomenon and how managers perceive it. This study intends to provide some empirical support. The study is based on a phenomenological approach and unstructured interviews have been used for collecting data. The results showed that managers' handling of is mainly done through communication and employee involvement in the change. The managers perceive the phenomenon as a phase where people feel frustrated, insecure and exhausted. The study concludes that a greater understanding for how the phenomenon is perceived and managed by managers in an ongoing organizational change has been made.
4

Analysis of an Exposed Portion of the Badwater Turtleback Shear-zone, Death Valley, California, USA

Jarrett, Corey 10 April 2018 (has links)
The exposed shear zone within the footwall of the Badwater turtleback presents an excellent opportunity to explore the brittle-ductile transition. Within this shear zone, a variety of lithologies preserve the last stages of crystal-plastic deformation concurrent with exhumation of the turtleback. The included field study captures a snapshot of each lithologic element during the last stages of ductile deformation. The exposed shear zone's journey through the brittle-ductile transition is analyzed using the deformation mechanisms of calcite and quartz. A history of strain partitioning is constructed through comparison of the strain and temperature environments needed to facilitate each mechanism of crystal-plastic deformation. As the shear zone cooled, strain was partitioned from quartz-rich mylonitic gneiss to the calcite-dominated marbles and mylonites. Correlation of deformation temperatures with previous studies further constrains the timing of the last stage of ductile deformation to between 13 and 6 Ma.
5

Surviving Death Valley : A How-To Guide on Success for Small Ventures

Parfenova, Alina, Mikneus, Stephanie January 2012 (has links)
Small business creation is a vital factor to any economy, but there is little research done on the challenges faced during intermediate stages in the life of a business that may prevent the success of an organization. The goal of this investigation is to determine what controllable factors inhibit growth within an organization, and how to minimize these barriers in order to reach success. The research focus is on small businesses in operation for more than four years, since this is the period in which support from governmental and private institutions becomes scarce and the organization is forced tomake decisions; not only to survive, but to promote evolution for the firm. This thesis has been written on commission for SME consultation firm BCM-QMS.
6

Death Valley reconstruction new piercingpoints in the Panamint Mountains and Resting Springs Range /

Guerrero, Francisco Jesus. January 2008 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.
7

Origin of major springs in the Amargosa Desert of Nevada and Death Valley, California.

Winograd, Isaac Judah,1931- January 1971 (has links)
Studies of the hydrogeology of the southern Great Basin differ widely in their conclusions regarding the origin of major springs at Ash Meadows, in the Amargosa Desert, Nevada, and in the Furnace Creek- Nevares Spring area in Death Valley, California. The diversity of opinion reflects the following. First, ground water commonly moves between intermontane basins of the region via thick, highly fractured, and areally extensive Paleozoic carbonate rocks; the resulting lack of correspondence of topographic and ground-water divides precludes routine utilization of the water-budget method in the study of these basins. Second, subsurface hydraulic data for the regional carbonate aquifer are sparse and difficult to interpret because of the complex subsurface disposition of and hydraulic barriers within the aquifer. An analysis of hydrologic, geologic, geochemical, and isotopic data permits a first approximation of the subsurface watershed tributary to the cited spring groups. Water temperature, chemistry, isotope content, hydraulic head, and geologic relations indicate that the major springs at Ash Meadows and in the Furnace Creek-Nevares Spring area, though emerging from unconsolidated Quaternary strata, are fed by water moving directly from the underlying carbonate aquifer of Paleozoic age. Joint use of potentiometric, geologic, and isohyetal maps indicates that the subsurface watershed tributary to Ash Meadows is no smaller than 4,500 square miles. The Ash Meadows ground-water basin is bordered on the south and east by the Spring Mountains and Sheep Range, the principal recharge areas, and on the west by the Belted Range, Eleana Range, and Shoshone Mountain. A northern boundary was not definable, and some underflow from White River ground-water basin, 90 miles northeast of the springs, is probable. The hydrogeologic data do not support the conclusion of earlier studies that underflow from Pahrump Valley is the major source of the spring discharge at Ash Meadows; probably no more than a few percent of the total comes from that valley. Comparison of the size, climate, and discharge from the Ash Meadows basin with that of the surface watershed tributary to the Furnace Creek-Nevares Spring area indicates that most of the spring discharge in east-central Death Valley originates well beyond its confines. Disposition of the carbonate aquifer favors the movement of ground water into Death Valley from central Amargosa Desert. Water in the carbonate aquifer in the latter area may be derived from the Ash Meadows basin, from the overlying valley fill, or both. Five hydrochemical facies were distinguished by percentage of major cations and anions in ground water from 147 sources. The hydrochemical facies reflect both the mineralogy of strata within recharge areas and downward crossflow from a Tertiary tuff aquitard into the carbonate aquifer. The areal distribution of these facies provides evidence for a northeasterly source of the Ash Meadows discharge, absence of significant underflow from Pahrump Valley to Ash Meadows, and movement of water from the central Amargosa Desert to the Furnace Creek- Nevares Spring area. The data are also compatible with southwestward underflow into the Ash Meadows basin from the White River basin. The deuterium content of 53 water samples from 27 major valleylevel springs and selected wells falls into several areally distinct patterns which suggest that 35 percent of the Ash Meadows discharge is derived from the White River basin, that underflow from Pahrump Valley is unlikely, and that water discharging in the Furnace Creek-Nevares Spring area may be related to water in the carbonate aquifer within the Ash Meadows basin. However, other interpretations are possible indicating that unequivocal interpretations about the regional flow system cannot be made from isotopic data alone.
8

QUANTIFYING RECHARGE DURING THE LAST GLACIAL MAXIMUM IN THE DEATH VALLEY REGIONAL FLOW SYSTEM

Hecker, Joel W. 06 August 2012 (has links)
No description available.
9

LIFE IN THE RAIN SHADOW: UNDERSTANDING SOURCES OF RECHARGE, GROUNDWATER FLOW, AND THEIR EFFECTS ON GROUNDWATER DEPENDENT ECOSYSTEMS IN THE PANAMINT RANGE, DEATH VALLEY, CALIFORNIA, USA

Carolyn L. Gleason (5930639) 16 January 2019 (has links)
<div> <p>Despite its location in the rain shadow of the southern Sierra Nevada, the Panamint Range within Death Valley National Park, CA hosts a complex aquifer system that supports numerous springs. These springs, in turn, support unique groundwater-dependent ecological communities. Spring emergences range in elevation from 2434 m above sea level (within the mountain block) to 77 m below sea level (in the adjacent basins). Waters were collected from representative Panamint Range springs and analyzed for environmental isotopes and geochemical tracers to address the following questions: 1) What is the primary source of recharge for the springs? How much recharge occurs on the Panamint Range? 2) What groundwater flowpaths and geologic units support springflow generation? and 3) What are the residence times of the springs? The stable isotopic composition (δ<sup>18</sup>O and δ<sup>2</sup>H) of spring water and precipitation indicate that localized high-elevation snowmelt is the dominant source of recharge to these perennial springs, though recharge from rainfall is not wholly insignificant. Geochemical evolution was evaluated using principle component analysis to compare the concentrations of all major spring cations and anions in a multidimensional space and group them according to dominant geochemical signatures. These resulting geochemical groups are controlled primarily by topography. The Noonday Dolomite and other carbonate units in the range are identified as the water-bearing units in the mountain block based on the <sup>87</sup>Sr/<sup>86</sup>Sr of spring waters and rock samples. These units also offer higher hydraulic conductivities than other formations and are chemically similar. Radiocarbon- and <sup>3</sup>H derived residence times of these spring waters range from modern to approximately 1840 years, with the shortest residence times at higher altitudes and Hanaupah Canyon and increasing residence times with decreasing altitude. This residence time-altitude relationship is likewise likely topography-driven though there are significant disparities in mountain block storage between the various canyons of the range resulting in variable residence times between drainages. Lower Warm Springs A and B, however, are the exceptions to this trend as they emerge at lower altitudes (750m above sea level) and are likely driven by the transport of groundwater to the surface along faults which increases both the temperature and groundwater residence times of waters from these springs. Benthic macroinvertebrates and benthic and planktonic microbes were also sampled for each spring studied. BMI and microbial community structure in the Panamint Range is likewise topography-controlled with more tolerant communities at lower elevations (within more chemically evolved waters) and less tolerant species in the unevolved waters at higher elevations.</p></div>

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