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 Degree Level: Master's
 Collection: UNT Theses and Dissertations
Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

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Date: May 2001
Creator: Hillin, Clifford K.
Description: This study utilized GIS and statistical methods to map the spatial variability of nitrate and related groundwater constituents in 30 counties above the Seymour Aquifer, analyze temporal patterns of nitrate pollution, identify probable sources of pollution, and recommend water development strategies to minimize exposure to nitrate and reduce future aquifer contamination. Nitrate concentrations in excess of 44 mg/L (US EPA limit) were commonly observed in the Seymour Aquifer region, especially in the central agricultural belt. Data indicated that this is an ongoing problem in the Seymour Aquifer and that agricultural activity and rural septic systems are the likely sources of the nitrate. Inconclusive results emphasized the need for a more comprehensive spatial and temporal water quality monitoring.
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Evaluation of MPLS Enabled Networks

Evaluation of MPLS Enabled Networks

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Date: May 2003
Creator: Ratnakaram, Archith
Description: Recent developments in the Internet have inspired a wide range of business and consumer applications. The deployment of multimedia-based services has driven the demand for increased and guaranteed bandwidth requirements over the network. The diverse requirements of the wide range of users demand differentiated classes of service and quality assurance. The new technology of Multi-protocol label switching (MPLS) has emerged as a high performance and reliable option to address these challenges apart from the additional features that were not addressed before. This problem in lieu of thesis describes how the new paradigm of MPLS is advantageous over the conventional architecture. The motivation for this paradigm is discussed in the first part, followed by a detailed description of this new architecture. The information flow, the underlying protocols and the MPLS extensions to some of the traditional protocols are then discussed followed by the description of the simulation. The simulation results are used to show the advantages of the proposed technology.
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Interspecimen Study of Bone to Relate Macromechanical, Nanomechanical and Compositional Changes Across the Femoral Cortex of Bone

Interspecimen Study of Bone to Relate Macromechanical, Nanomechanical and Compositional Changes Across the Femoral Cortex of Bone

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Date: May 2013
Creator: Nar, Mangesh
Description: Mechanics of bone is widely studied and researched, mainly for the study of fracture. This has been done mostly on a macro scale. In this work hierarchical nature of bone has been explored to investigate bone mechanics in more detail. Flexural test were done to classify the bones according to their strength and deflection. Raman spectroscopy analysis was done to map the mineralization, collagen crosslinking changes across the thickness of the bone. Nanoindentation was done to map indentation hardness and indentation modulus across femoral cortex of the bone. The results indicate that the composition of the bone changes across the thickness of the femoral cortex. The hypothesis is confirmed as increase in mineralization, carbonate to phosphate ratio and collagen crosslinking shows the effect as increased indentation hardness and modulus and decreased deflection.
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Investigating Postpartum Depression in Southern Rural Egypt and Effects of Sertraline on Fsh and Lh Gene Expression on Fathead Minnows Using Rt-pcr

Investigating Postpartum Depression in Southern Rural Egypt and Effects of Sertraline on Fsh and Lh Gene Expression on Fathead Minnows Using Rt-pcr

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Date: May 2013
Creator: Mohamed, Hagar Abdo
Description: Postpartum depression (PPD) is a major health problem that affects many women worldwide. In Egypt, PPD is neglected despite the expected high prevalence rate among women during the transition period after the Egyptian revolution. This research investigated the prevalence, risk factors, and interventions of postpartum depression in southern rural Egypt. Interviews were conducted with 57 participants recruited from public and private hospitals. Questionnaires and the Arabic version of the Edinburgh Postnatal Depression Scale were administered. The prevalence of PPD is 73.7%. PPD is associated with low income and age at childbirth. Most participants regarded screening mothers after childbirth for PPD as effective; in comparison to, antidepressants that were regarded by most participants as ineffective. Women in southern rural Egypt prefer high number of pregnancies, so investigating the influence of sertraline, an antidepressant medication, on female hormones becomes important. In this research, fathead minnows were exposed to 3 and 10 ppb sertraline for 7 days. Real-time Polymerase Chain Reaction was used to detect the change in gene expression of the Follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Results showed that a down regulation at the 10 ppb was evident on the LH and to a lesser extent on FSH. Our results ...
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My Crown Is in My Heart, Not on My Head: Heart Burial in England, France, and the Holy Roman Empire From Medieval Times to the Present

My Crown Is in My Heart, Not on My Head: Heart Burial in England, France, and the Holy Roman Empire From Medieval Times to the Present

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Date: May 2013
Creator: Duch, Anna M.
Description: Heart burial is a funerary practice that has been performed since the early medieval period. However, relatively little scholarship has been published on it in English. Heart burial began as a pragmatic way to preserve a body, but it became a meaningful tradition in Western Europe during the medieval and early modern periods. In an anthropological context, the ritual served the needs of elites and the societies they governed. Elites used heart burial not only to preserve their bodies, but to express devotion, stabilize the social order and advocate legitimacy, and even gain heaven. Heart burial assisted in the elite Christian, his or her family, and society pass through the liminal period of death. Over the centuries, heart burial evolved to remain relevant. The practice is extant to the present day, though the motivations behind it are very different from those of the medieval and early modern periods.
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Primary Cilia in the Oligodendrocyte Lineage

Primary Cilia in the Oligodendrocyte Lineage

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Date: May 2013
Creator: Hao, Yung-Chia
Description: oligodendrocytes migrate from the corpus callosum into the overlying cortex. The incidence of cilia did not change markedly across age groups, and did not vary consistently with the number of processes per cell, which was used as an indication of the maturation stage of OPCs and young OLs. The mean percent of Olig1 immunopositive (Olig1+) cells having cilia across ages was 33.1% + 16.5%, with all ages combined. In O4+ cells of these mice, 56.7 + 3.6% had primary cilia. If it is the case that adult OLs do not have cilia, the point in the lineage when primary cilia are lost is still unknown. Adult mice that had been injected with cyclopamine to block cilia-dependent Shh signaling were examined to determine whether the rate of generating new OPCs was influenced. In the CC of control mice, the numerical density of Olig1+/BrdU+ cells was 1.29 + 0.07/mm2 was reduced to 0.68 + 0.38/mm2 in the cyclopamine-injected group, and the numerical density of all BrdU+ cells (including both Olig1+ and Olig1- cells) of 4.55 + 1.50/mm2 in the control group was reduced to 3.14 + 1.27/mm2 in the cyclopamine-injected group. However, there were only 2 mice in each group and the ...
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Effect of Retting on Surface Chemistry and Mechanical Performance Interactions in Natural Fibers for High Performance Polymer Composites

Effect of Retting on Surface Chemistry and Mechanical Performance Interactions in Natural Fibers for High Performance Polymer Composites

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Date: May 2013
Creator: Ramesh, Dinesh
Description: Sustainability through replacement of non-renewable fibers with renewable fibers is an ecological need. Impact of transportation costs from South-east Asia on the life cycle analysis of the composite is detrimental. Kenaf is an easily grown crop in America. Farm based processing involves placing the harvested crop in rivers and ponds, where retting of the fibers from the plant (separation into fibers) can take 2 weeks or more. The objective of this thesis is to analyze industrially viable processes for generating fibers and examine their synergistic impact on mechanical performance, surface topography and chemistry for functional composites. Comparison has been made with commercial and conventional retting process, including alkali retting, enzymatic retting, retting in river and pond water (retting occurs by natural microbial population) with controlled microbial retting. The resulting kenaf fibers were characterized by dynamic mechanical analysis (DMA), Raman spectroscopy (FT-Raman), Fourier transform infrared spectroscopy (FT-IR), polarized optical microscopy (POM), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) optical fluorescence microscopy, atomic force microscopy (AFM) and carbohydrate analysis. DMA results showed that pectinase and microbe treated fibers have superior viscoelastic properties compared to alkali retting. XPS, Raman, FT-IR and biochemical analysis indicated that the controlled microbial and pectinase retting was ...
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Mis Raices, Mi Hogar: My Roots, My Home

Mis Raices, Mi Hogar: My Roots, My Home

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Date: May 2001
Creator: Ramirez, Diana C.
Description: The lack of ancestral record instilled in me this desire to hold on to memories, and to leave my children with permanent records or memories of our family. My desire to work with metals was inspired by the need to encapsulate a record of memories through a more permanent means. The durability of steel, I feel, can be used as a diary, in the form of an artistic and lasting object, rather than written words. The need to leave behind a legacy inspired me to explore the use of lockets and containers that have some resemblance to a reliquary. My intent was not one of religious purpose, but rather to create a locket or container that would reflect or contain symbols of where one's roots begin, the home.
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Mechanical Properties of Polymer Modified Mortar

Mechanical Properties of Polymer Modified Mortar

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Date: August 2002
Creator: Palos, Artemio
Description: The mechanical properties of the polymer-modified mortar are markedly improved over conventional cement mortar. We utilized recycled ABS in powder form and a polymer latex emulsion, polymer percentage ranges from 0 to 25 percent by polymer/cement ratio were investigated. The mechanical properties investigated were compression strength and adhesion strength. Compression strength effects did not have an impact on adhesion strength. Adhesion strength was calculated with pullout testing apparatus designed by the author. Results indicate that recycled ABS had a lower adhesive strength than the acrylic latex emulsion and the base mortar, but did increase in adhesive strength when mixed with maleic-anhydride. The adhesive strength was investigated for a Fiber Reinforced Polymer (FRP) made of an "E" glass fiber that is a continuous strand roving oriented and pre-tensioned longitudinally in an isopthalic polyester matrix material. The FRP rebar was compared to standard steel rebars, and found that the standard steel corrugated rebar had a higher adhesive strength, due to mechanical interlocking. This was clarified by measurements using a smooth steel rebar. Characterization of the polymer-modified mortar was conducted by pore analysis and scanning electron microscopy. Scanning Electron Microscopy was implemented to view the polymer particles, the cement fibrils formed by the ...
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Implementation of Scalable Secure Multicasting

Implementation of Scalable Secure Multicasting

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Date: August 2002
Creator: Vellanki, Ramakrishnaprasad
Description: A large number of applications like multi-player games, video conferencing, chat groups and network management are presently based on multicast communication. As the group communication model is being deployed for mainstream use, it is critical to provide security mechanisms that facilitate confidentiality, authenticity and integrity in group communications. Providing security in multicast communication requires addressing the problem of scalability in group key distribution. Scalability is a concern in group communication due to group membership dynamics. Joining and leaving of members requires the distribution of a new session key to all the existing members of the group. The two approaches to key management namely centralized and distributed approaches are reviewed. A hybrid solution is then provided, which represents a improved scalable and robust approach for a secure multicast framework. This framework then is implemented in an example application of a multicast news service.
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