Digital Commons Network^™

A Developmental Cycle Masks Output From The Circadian Oscillator Under Conditions Of Choline Deficiency In Neurospora, Mi Shi, Luis F. Larrondo, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

In Neurospora, metabolic oscillators coexist with the circadian transcriptional/translational feedback loop governed by the FRQ (Frequency) and WC (White Collar) proteins. One of these, a choline deficiency oscillator (CDO) observed in chol-1 mutants grown under choline starvation, drives an uncompensated long-period developmental cycle ( approximately 60-120 h). To assess possible contributions of this metabolic oscillator to the circadian system, molecular and physiological rhythms were followed in liquid culture under choline starvation, but these only confirmed that an oscillator with a normal circadian period length can run under choline starvation. This finding suggested that long-period developmental cycles elicited by nutritional stress …

Nesting And Foraging Characteristics Of The Black Carpenter Ant Camponotus Pennsylvanicus (Degeer) (Hymenoptera: Formicidae), Donald Oswalt

All Dissertations

Potential nesting sites of Camponotus pennsylvanicus (DeGeer) were investigated in South Carolina to determine if nesting sites features could be characterized by habitat features for black carpenter ant nests. Environmental data from forested plots showed large-scale habitat features such as vegetation density and canopy cover were not useful as indicators for the presence or absence of nests. Small-scale individual nest characteristics such as diameter at breast height of trees, log length, tree defect type or tree species were better indicators of occupied nests. In my study, C. pennsylvanicus preferred mature hardwood (Quercus spp.) trees approximately 30 cm in diameter and …

A Pilot Study On The Effects Of Temperature On The Material Properties Of Prestressed Concrete And The Use Of Thermogravimetric Analysis In The Assessment Of Heat-Affected Concrete, Kacie Caple

All Theses

An understanding of the material property changes in building materials due to exposure to a fire is needed for accurate damage assessment of a structure. Discussion pertaining to material property changes and the bond between concrete and prestressing steel following elevated temperature exposures is presented. Evaluation of the use of thermogravimetric analysis (TGA) as a post-fire analysis tool to determine the maximum temperature exposure of concrete is also included.
Heated concrete cylinders were tested to determine the compressive strength and modulus of elasticity changes of concrete. Heated steel prestressing strands were tested in tension to determine changes in the ultimate …

Sensitivity Of Half-Cell Potential Measurements To Properties Of Concrete Bridge Decks, Thad Marshall Pinkerton

Theses and Dissertations

Half-cell potential testing has been recommended as a non-destructive method for assessing the corrosion potential of reinforcing steel in concrete bridge decks. The technique is particularly useful because it can be utilized to evaluate the probability of corrosion before damage is evident at the surface of a bridge deck. The specific objective of this research was to quantify the effects of age, chloride concentration, concrete cover thickness, spatial position, temperature, and presence or condition of epoxy coating on half-cell potential measurements of concrete bridge decks typical of those in Utah. The laboratory testing associated with this research followed a full-factorial …

Temperature Effects On Metabolic Rate Of Juvenile Pacific Bluefin Tuna Thunnus Orientalis, Jason M. Blank, Jeffery M. Morrissette, Charles J. Farwell, Mathew Price, Robert J. Schallert, Barbara A. Block

Biological Sciences

Pacific bluefin tuna inhabit a wide range of thermal environments across the Pacific ocean. To examine how metabolism varies across this thermal range, we studied the effect of ambient water temperature on metabolic rate of juvenile Pacific bluefin tuna, Thunnus thynnus, swimming in a swim tunnel. Rate of oxygen consumption (M_O2) was measured at ambient temperatures of 8–25°C and swimming speeds of 0.75–1.75 body lengths (BL) s^–1. Pacific bluefin swimming at 1 BL s^–1 per second exhibited a U-shaped curve of metabolic rate vs ambient temperature, with a thermal minimum zone between …

Increased Performance Of Battery Packs By Active Equalization, Jonathan W. Kimball, Brian T. Kuhn, Philip T. Krein

Electrical and Computer Engineering Faculty Research & Creative Works

Battery packs for most applications are series strings of electrochemical cells. Due to manufacturing variations, temperature differences, and aging, the individual cells perform differently. When a complete pack is charged and discharged as a single two-terminal circuit element, some cells are chronically overcharged, undercharged, or overdischarged, all of which act to reduce cell life. The performance and life of the complete pack is limited by the weakest cell. Many methods have been proposed and explored to mitigate this problem. In the present work, a switched-capacitor converter is shown to be a simple and effective method to maintain equal cell or …

Fully Codon-Optimized Luciferase Uncovers Novel Temperature Characteristics Of The Neurospora Clock, Van D. Gooch, Arun Mehra, Luis F. Larrondo, Julie Fox, Melissa Touroutoutoudis, Jennifer J. Loros, Jay C. Dunlap

Dartmouth Scholarship

We report the complete reconstruction of the firefly luciferase gene, fully codon optimized for expression in Neurospora crassa. This reporter enhances light output by approximately 4 log orders over that with previously available versions, now producing light that is visible to the naked eye and sufficient for monitoring the activities of many poorly expressed genes. Time lapse photography of strains growing in race tubes, in which the frq or eas/ccg-2 promoter is used to drive luciferase, shows the highest levels of luciferase activity near the growth front and newly formed conidial bands. Further, we have established a sorbose medium colony …

The Bertalanffy Growth Equation: Theory Of Paulys Auximetric Plots, Eric L. Charnov

Biology Faculty & Staff Publications

No abstract provided.

Process Optimization And Consumable Development For Chemical Mechanical Planarization (Cmp) Processes, Subrahmanya R. Mudhivarthi

USF Tampa Graduate Theses and Dissertations

Chemical Mechanical Planarization (CMP) is one of the most critical processing steps that enables fabrication of multilevel interconnects. The success of CMP process is limited by the implementation of an optimized process and reduction of process generated defects along with post CMP surface characteristics such as dishing and erosion. This thesis investigates to identify various sources of defects and studies the effect of factors that can be used to optimize the process. The major contributions of this work are: Understanding the effect of temperature rise on surface tribology, electrochemistry and post CMP pattern effects during the CMP process; investigating the …

The Impact Of Temperature Change On Energy Demand: A Dynamic Panel Analysis, Enrica De Cian, Elisa Lanzi , Roberto Roson

Fondazione Eni Enrico Mattei Working Papers

This paper presents an empirical study of energy demand, in which demand for a series of energy goods (Gas, Oil Products, Coal, Electricity) is expressed as a function of various factors, including temperature. Parameter values are estimated econometrically, using a dynamic panel data approach. Unlike previous studies in this field, the data sample has a global coverage, and special emphasis is given to the dynamic nature of demand, as well as to interactions between income levels and sensitivity to temperature variations. These features make the model results especially valuable in the analysis of climate change impacts. Results are interpreted in …

Variations In Diurnal Temperature Range In The Southeast United States Due To Land Use/Land Cover Classification, 1995-2004, Kelsey Nicole Scheitlin

Theses and Dissertations

Daily temperature variations across an area can often be attributed to differences in land use/land cover (LULC). This study focuses on the relationships between the diurnal temperature ranges (DTRs) of 145 weather stations, classified as urban, agriculture, evergreen forests, deciduous forests, pine forests, and mixed forests. Paired samples t-tests were employed to test for significant DTR differences due to LULC type, season, and air mass type. Conflicting with previous research, agricultural areas reported the lowest DTRs, which may be due to the vegetation or to other physiographic variables. The forest types showed very few significant DTR differences. All of the …

Improved Techniques For Nonlinear Electrothermal Fet Modeling And Measurement Validation, Charles Passant Baylis Ii

USF Tampa Graduate Theses and Dissertations

Accurate transistor models are important in wireless and microwave circuit design. Large-signal field-effect transistor (FET) models are generally extracted from current-voltage (IV) characteristics, small-signal S-parameters, and large-signal measurements. This dissertation describes improved characterization and measurement validation techniques for FET models that correctly account for thermal and trapping effects.

Demonstration of a customized pulsed-bias, pulsed-RF S-parameter system constructed by the author using a traditional vector network analyzer is presented, along with the design of special bias tees to allow pulsing of the bias voltages. Pulsed IV and pulsed-bias S-parameter measurements can provide results that are electrodynamically accurate; that is, thermal and …

Climate Justice: The Next Movement [Outline], Richard J. Lazarus

The Climate of Environmental Justice: Taking Stock (March 16-17)

Presenter: Richard J. Lazarus, Professor of Law, Georgetown University Law Center

2 pages.

Satellite-Derived Surface Current Divergence In Relation To Tropical Atlantic Sst And Wind, Robert W. Helber, Robert H. Weisberg, Fabrice Bonjean, Eric S. Johnson, Gary S. Lagerloef

Marine Science Faculty Publications

The relationships between tropical Atlantic Ocean surface currents and horizontal (mass) divergence, sea surface temperature (SST), and winds on monthly-to-annual time scales are described for the time period from 1993 through 2003. Surface horizontal mass divergence (upwelling) is calculated using surface currents estimated from satellite sea surface height, surface vector wind, and SST data with a quasi-linear, steady-state model. Geostrophic and Ekman dynamical contributions are considered. The satellite-derived surface currents match climatological drifter and ship-drift currents well, and divergence patterns are consistent with the annual north–south movement of the intertropical convergence zone (ITCZ) and equatorial cold tongue evolution. While the …

Understanding And Modeling The Effect Of Temperature And Daylength On Soybean Phenology Under High-Yield Conditions, T. D. Setiyono, Albert Weiss, James E. Specht, A. M. Bastidas, Kenneth G. Cassman, A. Dobermann

Department of Agronomy and Horticulture: Faculty Publications

Temperature and photoperiod can be used to simulate soybean (Glycine max [L.] Merr) phenology because they serve as surrogates for complex biochemical pathways leading to the appearance of certain developmental stages at the whole plant level. We developed a soybean phenology model (SOYDEV) which utilizes non-linear temperature and photoperiod functions and separates floral induction and post-induction for simulating time of flowering. This model accurately simulated the dynamics of vegetative development, final node number and the occurrence of major reproductive stages such as flowering (R₁), beginning pod (R₃), mid-pod elongation (R_3,5), beginning seed (R …

Banda Forearc Metamorphic Rocks Accreted To The Australian Continental Margin: Detailed Analysis Of The Lolotoi Complex Of East Timor, Carl Eldon Standley

Theses and Dissertations

Petrologic, structural and age investigations of the Lolotoi Complex of East Timor indicate that it is part of a group of thin metamorphic klippen found throughout the region that were detached from the Banda forearc and accreted to the NW Australian continental margin during Late Miocene to Present arc-continent collision. Metamorphic rock types are dominated by (in order of greatest to least abundance), greenschist, graphitic phyllite, quartz-mica schist, amphibolite and pelitic schist. Mineral, whole rock, and trace element geochemical analyses of metabasites indicate that protolith compositions are consistent with tholeiitic basalt and basaltic andesite with mixed MORB and oceanic arc …

Current-Sensed Interconnects: Static Power Reducation And Sensitivity To Temperature, Sheng Xu

Masters Theses 1911 - February 2014

Global on-chip interconnects in deep sub-micron CMOS present challenges in satisfying delay constraints in the presence of noise and dramatic temperature variations, while minimizing energy consumption due to leakage and static power. Although repeaters are typically used to reduce delay and maintain signal integrity in long interconnects, they introduce significant area, power (both dynamic and leakage), delay, noise and design overhead as well as exacerbating variations due to their local power supply noise and temperature. Current-Sensing is an alternative to repeaters that transfers signals with no intermediate circuits by sensing current rather than voltage at the end of a long …

The Effect Of Temperature On Development And Behavior Of Relict Leopard Frog Tadpoles (Rana Onca), Jeffrey Abraham Goldstein

UNLV Retrospective Theses & Dissertations

Relict Leopard frogs (Rana onca) are found in thermal springs with water temperatures in excess of 30°C at the source but it's unknown whether tadpoles require reintroduction sites with specific thermal conditions for development. Tadpole survivorship at 20, 25 and 30°C was 84, 93.8, and 66%, respectively, while none survived at 35°C. Time to metamorphosis was significantly shorter for 25°C acclimation group (62+/-8 days) followed by the 30° (106+/-51 days) and 20°C (260+/-47 days) acclimation groups. Development was arrested in the 15°C acclimated group and survivorship declined to 63.8% after 191 days. However, 80% of the surviving larvae completed metamorphosis …

Applying Of Mechanical Failure Criteria Of Brittle Material To The Design Of High Temperature Heat Exchanger, Taha Mohamed

UNLV Retrospective Theses & Dissertations

Previous studies have suggested using a ceramic high temperature heat exchanger as a sulfuric acid decomposer for hydrogen production within the sulfur iodine thermochemical cycle. The decomposer was manufactured using fused ceramic layers that allow the creation of channels with dimensions below one millimeter. The heat exchanger is expected to operate in the range of 950°C. Thermal stresses are however induced in the heat exchanger ceramic components. In this study, proper failure criteria are selected to evaluate the safety level of the ceramic components. A three-dimensional computational model is developed to investigate the fluid flow, heat transfer, stresses and chemical …

Numerical Study Of High Temperature Heat Exchanger And Decomposer For Hydrogen Production, Valery Ivanovich Ponyavin

UNLV Retrospective Theses & Dissertations

This dissertation deals with three-dimensional computational modeling of a high temperature heat exchanger and decomposer for hydrogen production based on sulfur-iodine thermochemical water splitting cycle, a candidate cycle in the U.S. Department of Energy Nuclear Hydrogen Initiative. The conceptual design of the shell and plate decomposer is developed by Ceramatec, Inc. The hot helium from a nuclear reactor (T=975°C) is used to heat the SI (sulfuric acid) feed components (H2O, H2SO4 , SO3) to get appropriate conditions for the SI decomposition reaction (T>850°C). The inner wall of the SI decomposition part of the decomposer is coated by a catalyst …

Effects Of Temperature, Strain Rate And Silicon Content On Dynamic Strain Ageing Of Modified Chromium-Molybdenum Steel, Pankaj Kumar

UNLV Retrospective Theses & Dissertations

Martensitic T91 grade steels exhibited a susceptibility to dynamic strain aging (DSA) by virtue of gradually reduced failure strain (ef) and formation of serrations within a susceptible temperature range, irrespective of the silicon (Si) content. Since DSA is a thermally-activated process involving diffusion of solute elements, the effects of temperature and strain rate have been investigated. The activation energy associated with the diffusion process was gradually enhanced with increasing Si content at comparable temperatures. A maximum dislocation density was determined at 400°C at which lowest ef was observed in the engineering stress versus engineering strain diagram. The resistance to plastic …

Mechanism Of Stabilization Of A Bacterial Collagen Triple Helix In The Absence Of Hydroxyproline, Angela Mohs, Teresita Silva, Takeshi Yoshida, Ravish Amin, Slawomir Lukomski, Masayori Inouye, Barbara Brodsky

Faculty & Staff Scholarship

No abstract provided.

Temperature Effect On Tert-Butyl Alcohol (Tba) Biodegradation Kinetics In Hyporheic Zone Soils, M. H. Greenwood, Ronald C. Sims, J. E. Mclean, W. J. Doucette

Biological Engineering Faculty Publications

Background

Remediation of tert-butyl alcohol (TBA) in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-butyl formate (TBF). The effect of temperature on TBA biodegradation has not been not been published in the literature.

Methods

Biodegradation of [U ¹⁴C] TBA was determined using hyporheic zone soil microcosms.

Results

First order mineralization rate constants of TBA at 5°C, 15°C and 25°C were 7.84 ± 0.14 × 10^-3, 9.07 ± 0.09 × 10^-3, and 15.3 ± 0.3 …

Ferroelectric Properties Of Bi3.25sm0.75v0.02t2.98o12 Thin Film At Elevated Temperature, Zhenxiang Cheng, Xiaolin Wang, S X. Dou, Kiyoshi Ozawa, Hideo Kimura

Australian Institute for Innovative Materials - Papers

The ferroelectric behavior in terms of electrical polarization and fatigue and dielectric properties at elevated temperature of the ferroelectric Bi_3.25Sm_0.75V_0.02T_2.98O₁₂ thin film fabricated by the pulsed laser deposition method were studied. Its switchable polarization increased at elevated temperature, and the coercive field decreased at the same time due to the strong domain depinning process at higher temperature. This film shows almost a polarization-fatigue-free character at room temperature, but the aggregation and diffusion of the thermally activated long-range oxygen vacancies caused strong domain pinning, and thus a poor fatigue resistance was observed …

Impact Of Sintering Temperature On The Physical Properties Of The Superconducting Ferromagnet: Rusr2eu1.5ce0.5cu2o10, Rashmi Nigam, Alexey V. Pan, S X. Dou

Faculty of Engineering - Papers (Archive)

We report the influence of the sintering temperature on the electromagnetic behavior for the RuSr₂Eu_1.5Ce_0.5Cu₂O₁₀ material, in which superconductivity and ferromagnetism coexist. The inadequate heat treatment results in the coexistence of the secondary Ru-1212 phase along with the dominant Ru-1222 phase. The presence of two phases leads to the magnetic superposition of the signals from both phases, which results in the observation of a small peak around 120–130 K. In the pure Ru-1222 no such magnetic anomaly is observed. In addition, the impure samples exhibit a double step superconductivity transition. In …

Amorphous Carbon-Coated Silicon Nanocomposites: A Low-Temperature Synthesis Via Spray Pyrolysis And Their Application As High-Capacity Anodes For Lithium-Ion Batteries, See How Ng, Jiazhao Wang, David Wexler, Sau Yen Chew, Hua-Kun Liu

Faculty of Engineering - Papers (Archive)

This article introduces an effective, inexpensive, and industrially oriented approach to produce carbon-coated Si nanocomposites as high-capacity anode materials for use in rechargeable lithium-ion batteries. Initially, nanosized Si particles (nm) were mixed in a citric acid/ethanol solution via ultrasonication. This mixture was further spray-pyrolyzed in air at low processing temperature (300-500 C), resulting in a homogeneous layer of carbon coating on the surface of the spheroidal Si nanoparticles. The effects of the processing temperature on the amorphous carbon content, the thickness of the carbon-coating layer, and the homogeneity of the carbon coating were studied in detail. These parameters strongly influenced …

High Water Regime Can Reduce Ammonia Volatilization From Soils Under Potato Production, Guodong Liu, Yuncong Li, A. K. Alva

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This research was conducted with Biscayne marl soil and Krome gravelly loam from Florida and Quincy fine sand and Warden silt loam from Washington to determine ammonia (NH₃) volatilization at various temperature and soil water regimes. Potassium nitrate (KNO₃), ammonium nitrate (NH₄NO₃), ammonium sulfate [(NH₄)₂SO₄], or urea were applied to the soil at a rate of 75 kg N ha^-1. Soil water regime was maintained at either 20% or 80% of field capacity (FC) and incubated at 11, 20, or 29 °C, which represented …

Homophones With Dual Interpretations As Affected By Temperature, Jamie Fritz

Undergraduate Psychology Research Methods Journal

This study investigated the effect of temperature on selection of neutral and negative connotations. Homophones, words with two meanings with the same pronunciations, with a neutral and negative connotation were used to detect differences in temperature environments (75 or 85 F). Homophones were selected based on their use in a study by J. B.Halberstadt, P.M. Niedenthal, and J. Kushner (1995) where homophone-meaning selection was affected by “happy” and “sad” music played during the experiment. The current study did not find statistical significance between the two temperatures to reject the null hypothesis, but demonstrated the need for further study in this …

Time-Temperature And Relative Humidity Profiles Of Chilled And Frozen Foods In Retail Outlets Nationwide, And Evaluation Of Related Practices, Caroline Garvan

Masters

Temperature abuse combined with poor operational practices are the dominant factors in the mishandling of food products which can result in outbreaks of food borne disease. The objective of this work was to determine efficacy of temperature and relative humidity control using recorded data and to assess the food safety management systems in operation in retail outlets in the Republic of Ireland. This study also aims to examine food safety risk to consumers as a result of inadequate temperature control and poor food hygiene practices using microbial analysis and predictive modelling. External air temperature, core temperature and relative humidity of …

Temperature Inside The Landfill: Effects Of Liquid Injection And Ambient Temperature, Amit Kumar

Electronic Theses and Dissertations

This study represents an analysis of comprehensive temperature and moisture content data collected from the anaerobic portion of a bioreactor landfill at the New River Regional Landfill, Florida, USA. The main focus of the study was the analysis of effects of the liquid injection on the temperature inside the landfill. When the leachate or groundwater at lower temperature than the landfilled waste is injected into the landfill, it has an initial cooling effect on the waste until the biological activity, enhanced by the additional moisture, releases heat. This cooling effect was tested in the study to determine whether it could …