Energy for rural development : a case study in Bihar, India

Hurst, Christopher UMI 1983 국내박사

A hardware controlled parallel processing system

Hurst, D. C [BRITS] 1981 국내박사

Characterization of the lignin residue from hydrolysis of sweetgum wood with superconcentrated hydrochloric acid

Winston, Marsha Hurst University Microfilms International 1987 국내박사

Molecular-beam epitaxial growth of low-dark-current avalanche photodiodes

Hurst, Jeffrey Byron The University of Texas at Austin 2007 해외박사(DDOD)

The quaternary material system InxGa1-xAs yP1-y is an important material system for optoelectronic devices, specifically covering optimum fiber optic wavelengths. Among the limitations of using this material system concerning photodetector performance is generation of carriers due to material defects and impurities. This dissertation reports on the growth optimization of InGaAs using molecular-beam epitaxy for low-dark-current avalanche photodiodes through the study of the effects of the growth conditions on dark current. An optimum growth temperature of 545°C and arsenic beam equivalent pressure of 2x10-5 Torr was found for producing the lowest dark current density. Avalanche photodiodes were implemented with a dark current density 80 mA/cm2 at 90% of the breakdown voltage.

Interpreting Richard Strauss's "Der Kraemerspiegel" from the perspectives of the performers and the audience

Hurst, Michael Shane University of North Texas 2007 해외박사(DDOD)

The purpose of this document is to examine Richard Strauss's 1918 song cycle Der Kramerspiegel in order to discern compositional intent and to address problems performers may face in communicating the work to a contemporary audience. Examining the existing literature, it is never clearly stated why Strauss composed such an anomalous song cycle that defied aesthetic and generic norms of the day. The premise taken in this study is that Strauss, who was litigiously forced to write the work in order to fulfill a contract with the publisher Bote & Bock, composed certain difficulties into the cycle to make it less marketable and thus less profitable for the firm. Furthermore, he commissioned a text that lampooned the publishing industry in general and certain firms and individuals in particular. Following a brief history of Strauss's involvement with the publishing industry, general considerations for interpretation are examined. The individual songs are then explored, keeping in mind the text's word play and parody, Strauss's use of self-quotation, and the challenges performers and audiences face when confronting Kramerspiegel. Finally, the individual songs are explored, and suggestions for preparation and performance of Kramerspiegel are given suggesting a more operatic understanding of the piece, especially given the cycle's relationship to Strauss's opera Der Rosenkavalier.

Sequential optimization for low power digital design

Hurst, Aaron Paul University of California, Berkeley 2008 해외박사(DDOD)

The power consumed by digital integrated circuits has grown with increasing transistor density and system complexity. One of the particularly power-hungry design features is the generation, distribution, and utilization of one or more synchronization signals (clocks). In many state-of-the-art designs, up to 30%-50% of the total power is dissipated in the clock distribution network. In this work, we examine the application of sequential logic synthesis techniques to reduce the dynamic power consumption of the clocks. These optimizations are sequential because they alter the structural location, functionality, and/or timing of the synchronization elements (registers) in a circuit netlist. A secondary focus is on developing algorithms that scale well to large industrial designs. The first part of the work deals with the use of retiming to minimize the number of registers and therefore the capacitive load on the clock network. We introduce a new formulation of the problem and then show how it can be extended to include necessary constraints on the worst-case timing and initializability of the resulting netlist. It is then demonstrated how retiming can be combined with the orthogonal technique of intentional clock skewing to minimize the combined capacitive load under a timing constraint. The second part introduces a new technique for inserting clock gating logic, whereby a clock's propagation is conditionally blocked for subsets of the registers in the design that are not actively switching logic state. The conditions under which the clock is disabled are detected through the use of random simulation and Boolean satisfiability checking. This process is quite scalable and also offers the potential for additional logic simplification.

Growing up in medieval Nubia: Health, disease, and death of a medieval juvenile sample from Mis Island

Hurst, Carolyn Victoria Michigan State University 2013 해외박사(DDOD)

This research investigates the lives and deaths of subadults in a medieval Nubian context. Using a sample from two medieval Christian cemeteries on the island of Mis, the mortuary treatment and skeletal health of subadults were analyzed to manifest age-related cultural practices and pathologies. The island of Mis was located in the Fourth Cataract of the Nile and was excavated prior to its inundation as part of the Merowe Dam Archaeological Salvage Project. The focus of this research was the archaeological and skeletal data of the subadult Christian burials of cemeteries 3-J-10 (n = 52) and 3-J-11 (n = 136). Within the historic and environmental context of these cemeteries, the patterns of morbidity and mortality of culturally significant age groups were utilized to understand the biological stressors and hardships that faced Mis Island inhabitants during the medieval period. The medieval period in Nubia has been known as a time of prosperity with peace and flourishing trade relations with the Muslim rulers in Egypt. The beginning of this era, however, was a time of instability, with the rise of new kingdoms, conversion to Christianity, and attacks from Muslim armies. A peace treaty between the Egyptian rulers and the medieval Nubian kingdoms in the mid-seventh century ushered in the golden era by guaranteeing peace and stimulating trade. This period of stability lasted until the twelfth century when the Christian kingdoms began to decline and eventually disappeared and the population of Nubia converted to the Muslim faith. In the kingdom of Makuria, despite being far removed from the capital in a seemingly inhospitable area, the island of Mis was inhabited from the pre-Christian Meroitic period through the end of Christianity. At the northeastern end of the island, cemetery 3-J-11 was used as a burial ground from AD 300 to 1400, spanning the entire Christian period, while cemetery 3-J-10 was consecrated in AD 1100 and was in use until AD 1400 when a change to Muslim burial practices occurred. Although Christian rites prescribe simple east-west graves for all individuals, the assessment of mortuary variables revealed significant differences in the burial contexts of infants and young children. Skeletal indicators of stress, including enamel hypoplasias, cribra orbitalia, porotic hyperostosis, periostitis, scurvy and tuberculosis were used to evaluate the health experiences in each age cohort and in comparison to adult groups. The patterns of affliction indicate scurvy, megaloblastic anemia, and tuberculosis were present in these populations, suggesting there was likely limited access to nutrients such as animal protein, fruits, and vegetables that offer protection against these conditions. Furthermore, the manifestation of pathological lesions in the youngest individuals suggests the biological experience of stress began early in life and contributed to the elevated levels of infant and child mortality. Comparisons of skeletal health within Mis Island revealed few significant differences between cemeteries except for higher levels of cribra orbitalia in the 3-J-11 sample. Significant differences were also found between Mis Island and the contemporary site of Kulubnarti. The results of this work show medieval Nubian communities had both age-related mortuary practices and biological stressors that varied across age cohorts, space, and time. This suggests that life experiences were not homogenous across Nubia and more work needs to be done to understand the variability that exists.

Roles of cytochromes P450 and microsomal epoxide hydrolase in drug-drug interactions involving valproic acid and its analogues

Hurst, Susan Irene University of Washington 1999 해외박사(DDOD)

Valproic acid (VPA) therapy is complicated by inhibition-based drug-drug interactions with other anticonvulsants. It was hypothesized that VPA may inhibit one or more cytochrome P450 isoforms. VPA was incubated with selective cytochrome P450 (1A2, 2A6, 2C9, 2C19, 2E1, and 3A4) probes in microsomes and the only isoform that exhibited pronounced inhibition (57%, 3000 <math> <f> <g>m</g></f> </math>M) was CYP2C9. VPA competitively inhibited CYP2C9 with a K_i value of 1209 ± 167 <math> <f> <g>m</g></f> </math>M. It also inhibited the <italic>in vitro</italic> metabolism of phenytoin and phenobarbital. Neither non-specific microsomal protein-binding, time-dependent inactivation, nor liver/plasma partition ratios (rat model) could be used to reconcile measured <italic>in vitro</italic> K_i values with the observed clinical interactions (e.g. phenytoin and phenobarbital) and the extensive plasma protein-binding of VPA. Several VPA derivatives were investigated for their ability to inhibit microsomal epoxide hydrolase (mEH). Neither valproylglycinamide nor its metabolite valproylglycine were potent inhibitors of mEH compared to the antiepileptic drugs VPA and valpromide. Also, N-methyl-tetramethylcyclopropane carboxamide was not a potent mEH inhibitor. Its metabolite, tetramethylcyclopropane carboxamide, exhibited greater inhibition of mEH, but with IC₅₀s at least 20-fold larger than the IC₅₀ for valpromide. The clinical interaction between dezinamide and carbamazepine was investigated via the effects of dezinamide on CYP3A4 and mEH. Dezinamide had either no effect (probe R-warfarin) or it increased the activity of CYP3A4 (probe carbamazepine). Dezinamide inhibited mEH via mixed inhibition at concentrations that are likely to be obtained <italic>in vivo</italic> (K_i of 18.8 to 20.8 <math> <f> <g>m</g></f> </math>g/ml using various probe mEH substrates). Thus the overall predicted effect would be an increase in the major metabolite of carbamazepine, carbamazepine-10,11-epoxide. There was no effect of mEH allelic variance (H113/H113 or R139/R139 mutations) on valpromide inhibition of mEH. As valpromide is primarily a competitive inhibitor of mEH, the findings suggest these mutations do not affect inhibitor binding at the active site. If they can be generalized to other primarily competitive mEH inhibitors, they also suggest that individuals homozygous for these mutations are not more susceptible to mEH inhibition. However, the present findings do not preclude effects of these mutations on another enzyme site, relevant to the binding of a noncompetitive inhibitor.

Principal leadership-skill demands in a global context: A comparative study

Hurst, Kenneth C., Sr University of Southern California 2011 해외박사(DDOD)

The job of principals in the 21st century is to find the future and take their people to it, which will require them to keep an eye on the big picture of life to relentlessly ask, "For what kind of life are we preparing our students?" (Synder, Acker-Hocevar, & Synder, 2008). The purpose of this study was to examine principal leadership and the skill demands in a global context. This dissertation presents factors such as the failure of urban education, the impact of globalization on education, and the influence of changing demographics on education, as reasons why urban high school principals need to acquire new leadership skills. The hypothesis of this dissertation is that there are skills, professional development opportunities, and time priorities that urban high school principals can acquire and be involved in that will enable them to redesign schools that will prepare students to compete in a global context. This study utilized both inductive and deductive qualitative analysis approaches in determining the skills needed by urban high school principals. The study found eight significant skills needed by urban high school principals and four characteristics and attributes needed by urban high school principals. Additionally, the study found that most urban high schools principals do not receive the training necessary to prepare students to compete in a global context. However, the study revealed five significant findings regarding training needed by urban high school principals. Finally, the study found that the urban high school principals identified in this study are actively and knowledgeably demonstrating skills designed to extend learning into a global context.

Replication and silencing at the HMR-E compound origin in Saccharomyces cerevisiae

Hurst, Simi Thomas University of Illinois at Urbana-Champaign 2002 해외박사(DDOD)

This study investigated the relationship between two distinct biological processes, replication and silencing, as they occur from the <italic>HMR</italic> locus. Within this locus, an 868 base pair (bp) region termed <italic>HMR-E </italic> functions as both a silencer and an origin of DNA replication. Replication activity assays of the <italic>HMR-E</italic> region revealed that it consisted of not one, but a minimum of three independent subregions capable of ARS (autonomously replicating sequence) and chromosomal origin activity. Each subregion was also tested for silencing ability, and one was subsequently classified as the 138bp minimal silencer-origin to reflect its unique capacity to act as both an independent origin and an independent silencer. The other two subregions (L and R) were designated non-silencer origins. Accordingly, <italic>HMR-E </italic> was termed a compound origin to reflect its novel organization. To determine the relationship between silencing and replication at <italic> HMR</italic>, mutational analysis of the sequence of the minimal silencer-origin was performed. Mutation of a sequence is required for silencing improved initiation efficiency. Mutation of a gene encoding a silencing protein resulted in decreased silencing and increased initiation efficiency. Conversely, mutation of a gene encoding a replication protein resulted in decreased initiation and improved silencing. This report also addressed the influence the non-silencer origins might have upon replication and silencing. This line of inquiry revealed that the non-silencer origins contributed to both replication and silencing at the <italic>HMR</italic> locus. <italic>HMR-I</italic>, which is located approximately 3.0kb telomere proximal to <italic>HMR-E</italic>, also contributed to both replication and silencing at <italic>HMR</italic>. The investigation presented here revealed several key features about the <italic>HMR</italic> locus. Firstly, the origin at <italic>HMR-E</italic> has been redefined to include the L and R subregions, as well as the 138bp silencer-origin. Secondly, the silencer is larger than previously defined and may be coincident with the compound origin. Thirdly, the mutation of silencer sequence elements and genes encoding proteins that promote one process, results in the improvement of the other process. Based upon our examination of the relationship between replication and silencing at <italic>HMR-E</italic>, we hypothesize that the processes of replication and silencing may compete with one another at the <italic> HMR</italic> locus.