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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.
11

Using Sustainable Development as a Competitive Strategy

Spearman, Pat 01 January 2015 (has links)
Sustainable development reduces construction waste by 43%, generating 50% cost savings. Residential construction executives lacking adequate knowledge regarding the benefits of sustainable development practices are at a competitive disadvantage. Drawing from the diffusion of innovation theory, the purpose of this qualitative case study was to explore knowledge acquisition within the bounds of sustainable residential construction. The purposive sample size of 11 executive decision makers fulfilled the sample size requirements and enabled the extraction of meaningful data. Participants were members of the National Home Builders Association and had experience of a minimum of 5 years in residential construction. The research question addressed how to improve knowledge acquisition relating to the cost benefits of building green homes and increase the adoption rate of sustainable development among residential builders. Data were collected via semistructured telephone interviews, field observation, and document analysis. Transcribed data were validated via respondent validation, coded into 5 initial categories aligned to the focus of the research, then reduced to 3 interlocking themes of environment, competitive advantage, and marketing. Recommendations include developing comprehensive public policies, horizontal and vertical communications networks, and green banks to capitalize sustainable development programs to improve the diffusion of green innovation as a competitive advantage strategy. Business leaders could benefit from this data by integrating sustainable development practices into their business processes. Sustainable development reduces operational costs, increases competitive advantage for builders, and reduces greenhouse gas emissions. Implications for social change increase energy independence through conservation and developing a legislative policy template for comprehensive energy strategies. A comprehensive energy strategy promotes economic development, technological gains in all business sectors within the energy industry, and reduces energy costs for consumers.
12

Leadership Strategies for Maintaining Profitability in a Volatile Crude Oil Market

Braimoh, Lucky Anderson 01 January 2017 (has links)
Volatile crude oil prices significantly affect the profitability of crude oil firms. The purpose of this single case study was to explore strategies some crude oil and gas business leaders used to remain profitable during periods of crude oil price volatility. The target population comprised 8 crude oil and gas business leaders located in Calgary, Canada, whose company remained profitable despite crude oil price volatility. The transformational leadership theory formed the conceptual framework for the study. Data were collected through the use of semistructured face-to-face interviews, company reports, and field notes. Data analysis involved a modified Van Kamm method, which included descriptive coding, a sequential review of the interview transcripts, and member checking. Based on methodological triangulation and thematic analysis, 5 themes emerged from the study, including communication and engagement; motivation and empowerment; measurement, monitoring, and control; self-awareness and humility; and efficiency and optimization. The implications for social change include the potential for crude oil and gas companies in Calgary, Canada to manage production costs, ensure earnings and profitability, and thus improve the socioeconomic well-being of Calgary indigenes through improved employment opportunities.
13

Small Business Sustainability Strategies

Fillingim, Wayne A. 01 January 2018 (has links)
Small businesses provide 48% of private-sector jobs in the United States and play a vital role in the country's economic growth and development. Only half of U.S. small businesses survive for longer than 5 years. The purpose of this qualitative multiple-case study was to explore sustainability strategies managers of small oilfield service companies used to sustain their business for longer than 5 years. Data were collected from semistructured interviews with 10 managers--one manager from each of 10 different oilfield service companies located in the Rocky Mountain region of the United States and from review of publicly available documents and archived records. The conceptual framework for this study was the dynamic capability theory. Data analysis was conducted using Yin's 5-step data analysis process and methodological triangulation. Four themes emerged from the study: networking or relationship strategies, financial planning strategies, differentiation strategies, and education and experience strategies. The implications of this study for positive social change include the potential for small business managers to use these findings to develop strategies for profitability and sustainability resulting in job creation, poverty reduction, and socioeconomic development.
14

Retention Strategies for Oil and Gas Industry Managers

Gerard, Faye 01 January 2019 (has links)
The turnover cost of specialized employees in the oil and gas industry can exceed 400% of an employee's annual salary. The purpose of this multiple case study was to explore successful strategies that oil and gas company managers used to retain specialized employees. The specific population for the study was 8 managers from 4 oil and gas companies in a metropolitan city in the southern United States, which included 5 hiring managers and 3 engineering managers who had demonstrated success in retaining specialized employees. The conceptual lens used in this research study was the job embeddedness theory. Study data were collected through semistructured interviews, observations of participants' nonverbal cues, a review of company documents, and organizational websites. The interview data were analyzed using Yin's 5 steps for qualitative data analysis. The analysis resulted in 3 themes: (a) leadership engagement improved specialized employee retention, (b) flexibility through work–life balance improved specialized employee retention, and (c) monitoring and assessing retention through research tools and data analysis improved specialized employee retention. The implications of this study for positive social change include the potential to provide successful strategies for oil and gas company managers to retain specialized employees, which may contribute to improving promotion from within the oil and gas industry, reducing the study location area unemployment rates, and improving local job economies.
15

Experimental Study of High-Temperature Range Latent Heat Thermal Energy Storage

Wickramaratne, Chatura 14 November 2017 (has links)
Among all thermal energy storage (TES) systems, latent heat thermal energy storage (LHTES) attracts high interest due to its high energy density and high exergetic efficiency. Due to the high enthalpy of fusion and low cost, inorganic salts are becoming popular as phase change materials and are used as the storage media in LHTES systems. The main drawbacks for the inorganic salts are their low thermal conductivity and high reactivity above 500°C. Therefore, designing a cost-effective containment at these conditions with longevity is a challenge. Macro-encapsulation of the PCM is one way to solve both the PCM containment issue as well as the low thermal conductivity problem. However, finding a practically viable encapsulation technique is a challenge especially for temperatures above 500°C. In the present study, encapsulation techniques were investigated for two temperature ranges; 500°C – 600°C and 600°C above. Metallic encapsulation was adopted for the 500°C – 600°C temperature. Commercially available, low-cost carbon-steel tubes were used, and the encapsulation shape was cylindrical. A 200µm coating of Ni was applied to strengthen the corrosion resistance. For temperatures above 600°C, a novel approach involving the use of ceramic materials was investigated for encapsulating chloride based PCMs. Low-cost ceramics with excellent thermal and chemical stability under molten-salt conditions were identified as the encapsulants. The influence of sintering temperature on the reactivity of feldspar, ball clay, kaolin and the mixture thereof with molten sodium chloride was investigated. The results were used to develop an optimum ceramic capsule fabrication procedure, using a green ceramic body followed by sintering at 1190°C. An innovative sealing process of in-situ layered eutectic formation was introduced. Sealing was performed at a temperature above the eutectic melting point of the salt mixture but below the individual melting points of each salt. The fabricated capsule survived more than 500 thermal cycles without showing degradation in its thermo-physical properties. Alumina (99%) based capsule containing NaCl-KCl was tested successfully for 1000 thermal cycles with a PCM weight loss of less than 5%. A lab-scale setup was designed and constructed to test an industry scalable LHTES system suitable for supplementing heat to a steam-powered cycle. Metallic cylindrical capsules were used with a eutectic of sodium sulfate (Na2SO4) and potassium chloride (KCl), which melts at 515°C, as the PCM for energy storage. This system was modeled and validated with experimental measurements. The calculated ratio of exergy to energy efficiency was around 89% (for 380-535°C). Flow irregularities were found due to a bend in the flow channel. Therefore, flow conditioners were investigated. A modified system with the flow conditioners and radiation shields showed 98% exergy to energy efficiency ratio (for 495-535°C). The overall efficiency of the system, however, was found to be low due to the heat losses from the storage tank. Finally, a novel design of a TES system using spherical capsules is proposed with additional enhancement gained from the experimental work on the lab-scale LHTES system. The innovation of this design lies in the manufacturing process to forms multiple spherical capsules using sheet metals. The adoptability of this technique for higher or lower temperature LHTES applications depends on the properties of the selected sheet metal. Any formable sheet metal can be used depending on the compatibility with PCM and HTF.
16

A Cost Benefit Analysis of Using a Battery Energy Storage System (BESS) Represented by a Unit Commitment Model

Mihailovic, Nemanja 02 November 2018 (has links)
This thesis aims to provide a general overview of a cost and benefit analysis of incorporating a battery energy storage system within unit commitment model. The deregulation of the electricity market in the U.S. has only been around for the last two decades. With renewable energy and energy storage systems becoming less expensive, a decentralized market scheme is becoming more popular and plausible. The scope of this work is to provide a fundamental understanding of unit commitment and a cost analysis of applying a battery energy storage system to an already established power system. A battery energy storage system (BESS) was placed within a unit commitment schematic and modeled for a 7 day/168 hour forecast. Three models were generated, two with and one without the battery energy storage device (BESS). The comparison between the three systems was conducted to produce a visual economic justification to the feasibility of a BESS.
17

Organic Fluids and Passive Cooling in a Supercritical Rankine Cycle for Power Generation from Low Grade Heat Sources

Vidhi, Rachana 08 July 2014 (has links)
Low grade heat sources have a large amount of thermal energy content. Due to low temperature, the conventional power generation technologies result in lower efficiency and hence cannot be used. In order to efficiently generate power, alternate methods need to be used. In this study, a supercritical organic Rankine cycle was used for heat source temperatures varying from 125°C to 200°C. Organic refrigerants with zero ozone depletion potential and their mixtures were selected as working fluid for this study while the cooling water temperature was changed from 10-25°C. Operating pressure of the cycle has been optimized for each fluid at every heat source temperature to obtain the highest thermal efficiency. Energy and exergy efficiencies of the thermodynamic cycle have been obtained as a function of heat source temperature. Efficiency of a thermodynamic cycle depends significantly on the sink temperature. At areas where water cooling is not available and ambient air temperature is high, efficient power generation from low grade heat sources may be a challenge. Use of passive cooling systems coupled with the condenser was studied, so that lower sink temperatures could be obtained. Underground tunnels, buried at a depth of few meters, were used as earth-air-heat-exchanger (EAHE) through which hot ambient air was passed. It was observed that the air temperature could be lowered by 5-10°C in the EAHE. Vertical pipes were used to lower the temperature of water by 5°C by passing it underground. Nocturnal cooling of stored water has been studied that can be used to cool the working fluid in the thermodynamic cycle. It was observed that the water temperature can be lowered by 10-20°C during the night when it is allowed to cool. The amount of water lost was calculated and was found to be approximately 0.1% over 10 days. The different passive cooling systems were studied separately and their effects on the efficiency of the thermodynamic cycle were investigated. They were then combined into a novel condenser design that uses passive cooling technology to cool the working fluid that was selected in the first part of the study. It was observed that the efficiency of the cycle improved by 2-2.5% when passive cooling system was used.
18

A Multi-Period Mixed Integer Linear Programming Model for Desalination and Electricity Co-generation in Kuwait

Alqattan, Nael Abdulhameed 26 June 2014 (has links)
Water is the root of life and the engine that drives agriculture, industry, economy and services. The demand for water often necessitates desalination, particularly in arid coastal environments where there are several desalination technologies in use today such as Multi-Effect Distillation (MED) and Reverse Osmosis (RO). The key utility requirement for technologies such as desalination and population in general include energy in one form or another. Therefore, desalination and co-generation are often integrated. Another key utility is electricity which is generated from either renewable or non-renewable sources. The demands for water and electricity change over time and are subject to uncertainty. In this dissertation, a country-wide large-scale energy and water cogeneration planning model for Kuwait was proposed and solved. Five different plant technologies where the planning horizon used was set to 37 years starting in year 2014 and until 2050. A Mixed Integer Mathematical programming model was proposed and formulated using General Algebraic Modeling System (GAMS), the resulting model was solved using the CPLEX solver engine. In this research obtained detailed data on the consumption on water and energy in Kuwait and performed time series analysis of the population growth and individual behavior of water and energy consumption and novel method to represent cogeneration plants was implemented in the proposed mathematical programming model. ix A modeling framework that involves a data spreadsheet and a proprietary model was implemented. The data spreadsheet and the model were formulated as a template that can receive data from different applications. In addition, automation using Visual Basic for Application (VBA) was made to the data spreadsheets such that the data is sent to the model template, Gams-Cylix, and are written back to the spreadsheet. An analysis was made between oil-based plants, natural gas (NG) plants, and solar-based plants for co-generation. It was found that for water production solar-based plants can supply 50 percent or more of the demand during after period 2020 and after implementation and for electric power generation solar plants are limited. The results indicate the preferred technology for energy generation was NG-RO. With the implementation of solar based plants the electric power load is distributed among the technologies. NG-RO plants are more scalable and therefore were expanded to cope with the future demand. The percentage of the electric power supplied by solar plant was below 35 percent across the planning horizon. By the end of the planning horizon the percentage of electric power supplied by solar base plants was nearly 20 percent. Near 70 percent of the electric power was supplied by NG RO by period 2050. Other technologies had a representation of less than 10 percent by the end of the planning horizon.
19

Sustaining Rural Economies with Wind Development

Van Oss, Eric J. 01 January 2010 (has links)
This paper discusses the effects of wind development in rural areas. Areas of focus include: direct job creation, indirect job creation, tax revenue and government policies. The effects of state and federal renewable energy policies are discussed and well as the impacts to rural economies.
20

Environmental Critiques of Nuclear Energy

Hummel, William 01 May 2012 (has links)
This essay identifies and evaluates the most common environmental critiques made against nuclear energy development. Environmentalists articulate four major concerns: the destructive effects and health risks of uranium mining; the dangers posed by radiation releases and meltdowns; the difficult of nuclear waste disposal; and national security concerns, including nuclear weapons proliferation and the possibility of attack or sabotage. By characterizing and describing these concerns, we are better able to decide which problems are most compelling, and suggest possible policy-driven solutions.

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