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2018

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Articles 271 - 285 of 285

Full-Text Articles in Engineering

Assessment Of The Physical And Chemical Qualities Of Brine And The Application Of Nano Zerovalent Iron For The Treatment Of Brine Effluent, M. J. Alegbe, O. S. Ayanda, P. Ndungu, O. O. Fatoba, A. Nechaev, L. F. Petrik Jan 2018

Assessment Of The Physical And Chemical Qualities Of Brine And The Application Of Nano Zerovalent Iron For The Treatment Of Brine Effluent, M. J. Alegbe, O. S. Ayanda, P. Ndungu, O. O. Fatoba, A. Nechaev, L. F. Petrik

Mining Engineering Faculty Research & Creative Works

The arbitrary discharge of brine effluent from reverse osmosis treatment plants impacts negatively to the environment due to its high salinity. In the present study, brine effluent obtained from eMalahleni treatment plant, South Africa, was analyzed by pH, electrical conductivity and total dissolved solids measurements. The ion chromatography and the inductively coupled plasma optical emission spectroscopy were also used to examine the anion and cation content of the brine effluent. The analysis of major cations and anions indicated that the brine water quality was above the target water quality range for potable water. Geochemical modelling of the brine effluent classified …


Improving Workers' Safety And Health In The Zimbabwean Mining And Quarrying Industry, Bernard Mabika Jan 2018

Improving Workers' Safety And Health In The Zimbabwean Mining And Quarrying Industry, Bernard Mabika

Walden Dissertations and Doctoral Studies

Lack of effective occupational safety and health (OSH) strategies is a reason that

workplace accidents in the mining and quarrying industry remain high, making the

industry one of the riskiest operations worldwide. The purpose of this multiple case study

was to explore successful strategies mining and quarrying leaders in Zimbabwe used to

improve OSH. The key research question addressed successful strategies leaders in the

mining and quarrying industry use to improve employee occupational safety and health in

Zimbabwe. Six successful business leaders from 3 mining and quarrying mines in

Zimbabwe demonstrated an exception to unsafe practices, particularly through their

exceptional …


Relationship Between Airline Category, Geographical Region, And Safety Performance, Peter Simpson Jan 2018

Relationship Between Airline Category, Geographical Region, And Safety Performance, Peter Simpson

Walden Dissertations and Doctoral Studies

Passengers rank safety as a key factor in airline choice. Thus, safety performance impacts an airline's ability to attract customers. The purpose of this correlational study was to examine the relationship and difference between airline category low-cost carriers (LCCs) and full-service carriers (FSCs), geographical region, and safety performance measured by accident rates. The target population comprised all airlines in all countries that had an accident during the 14-year period 2004 to 2017. Data consisted of archival data of all global airline accidents and airline departure frequencies for the 14-year period. The theory of organizational accidents in complex sociotechnical systems explains …


Impact Of Mortgage Characteristics On Retail Mortgage Transaction Completion Time, Kareem Atalla Tannous Jan 2018

Impact Of Mortgage Characteristics On Retail Mortgage Transaction Completion Time, Kareem Atalla Tannous

Walden Dissertations and Doctoral Studies

In the mortgage industry, many mortgage lenders cannot manage mortgage workflow systems while meeting and exceeding organizational objectives. Organizations with an above-industry average turnaround time (ATT) to complete a retail mortgage transaction (RMT) from origination to funding experience revenue losses. Grounded in the proposition that mortgage loan purpose (MLP), mortgage loan type (MLT), and subject property type (SPT) impact ATT to complete an RMT, the purpose of this causal-comparative study was to assess the impact of MLP, MLT, and SPT on ATT to complete an RMT. Using archival data records (N = 146) from a selected mortgage institution in the …


Hydraulic Fracture Design Optimization For Nubian Sandstone Formation In Libya, Housameddin Mohamed Sherif Jan 2018

Hydraulic Fracture Design Optimization For Nubian Sandstone Formation In Libya, Housameddin Mohamed Sherif

Masters Theses

There is growing interest in developing unconventional oil and gas reserves in Libya, such as the tight portions of the Nubian sandstone.

Well-X7 is a development well drilled to a TD of 13,005' penetrating the Upper Nubain Sandstone (UNSS) at 12,122'-12,207' and the Lower Nubain Sandstone (LNSS) at 12,524'-12,880' KB. Based on open hole logs, the UNSS has 71 ft of net pay and the LNSS was found to have 295 ft of net pay. Openhole logs also showed low permeabilities of 2.5 and 3 md for the UNSS and LNSS, respectively. The well was initially perforated in both zones …


Mitigation Of Environmental Hazards Of Sulfide Mineral Flotation With An Insight Into Froth Stability And Flotation Performance, Muhammad Badar Hayat Jan 2018

Mitigation Of Environmental Hazards Of Sulfide Mineral Flotation With An Insight Into Froth Stability And Flotation Performance, Muhammad Badar Hayat

Doctoral Dissertations

"Today's major challenges facing the flotation of sulfide minerals involve constant variability in the ore composition; environmental concerns; water scarcity and inefficient plant performance. The present work addresses these challenges faced by the flotation process of complex sulfide ore of Mississippi Valley type with an insight into the froth stability and the flotation performance. The first project in this study was aimed at finding the optimum conditions for the bulk flotation of galena (PbS) and chalcopyrite (CuFeS₂) through Response Surface Methodology (RSM). In the second project, an attempt was made to replace toxic sodium cyanide (NaCN) with the biodegradable chitosan …


Wildfire Emissions In The Context Of Global Change And The Implications For Mercury Pollution, Aditya Kumar Jan 2018

Wildfire Emissions In The Context Of Global Change And The Implications For Mercury Pollution, Aditya Kumar

Dissertations, Master's Theses and Master's Reports

Wildfires are episodic disturbances that exert a significant influence on the Earth system. They emit substantial amounts of atmospheric pollutants, which can impact atmospheric chemistry/composition and the Earth’s climate at the global and regional scales. This work presents a collection of studies aimed at better estimating wildfire emissions of atmospheric pollutants, quantifying their impacts on remote ecosystems and determining the implications of 2000s-2050s global environmental change (land use/land cover, climate) for wildfire emissions following the Intergovernmental Panel on Climate Change (IPCC) A1B socioeconomic scenario.

A global fire emissions model is developed to compile global wildfire emission inventories for major atmospheric …


Profile Analysis Of Mobile Application Security, Adetunji A. Olunuga Jan 2018

Profile Analysis Of Mobile Application Security, Adetunji A. Olunuga

UNF Graduate Theses and Dissertations

ABSTRACT

This thesis conducts profile analysis on the mobile application security using peer-review articles that were published from 2010 to 2018. From the analysis, we will identify prolific authors, intuitions, and geographic regions as well as the topics addressed by the articles. The profile analysis will reveal most frequently used research methods, research approaches (quantitative, qualitative and mixed), and theories used to study the field. This thesis reveals that none of the researchers have made significant contributions to the field, and researches are not collaborating to solve their research problems. The profile analysis shows that surveys and experiments are the …


Investigation Of The Hydrodynamics And Scale-Up Of Advanced Triso Nuclear Fuel Manufacturing Using Sophisticated Measurement Techniques, Thaar M. Aljuwaya Jan 2018

Investigation Of The Hydrodynamics And Scale-Up Of Advanced Triso Nuclear Fuel Manufacturing Using Sophisticated Measurement Techniques, Thaar M. Aljuwaya

Doctoral Dissertations

"The successful performance and safety of the Very-High-Temperature Nuclear Reactors (VHTR) extremely depend on the quality of the TRISO nuclear fuel coated particles. However, the coating of the TRISO particles is delicate process and impacted by the hydrodynamics of spouted beds. Therefore, in this work, we applied advanced non-invasive measurement techniques which are gamma-ray computed tomography (CT) and radioactive particle tracking (RPT), to investigate foremost the local parameters to advance the fundamental understanding of the hydrodynamics and scale-up of gas-solid spouted beds. The CT technique has been applied to study the effects of particle density, particle size, bed size, and …


Guayule Plant Extracts As Binder Modifiers In Flexible (Asphalt) Pavement Mixtures, Steven Michael Lusher Jan 2018

Guayule Plant Extracts As Binder Modifiers In Flexible (Asphalt) Pavement Mixtures, Steven Michael Lusher

Doctoral Dissertations

"The guayule (pronounced, 'why-YOO-lee') plant is a woody perennial shrub that is native to areas of the southwestern United States and northern Mexico, and is a well-documented source of high-quality natural rubber. The U.S. needs a domestic source of natural rubber to allay concerns about its future availability. Cultivation of guayule in North America has been attempted many times since the late 19th century, and companies, including major tire manufacturers, are again investing in guayule research. However, full-scale commercialization of guayule rubber needs established markets for the two basic by-products of guayule rubber extraction: the plant resins (primarily non-rubber compounds) …


A New Signal Processing Method For Acoustic Emission/Microseismic Data Analysis, Charles Mborah Jan 2018

A New Signal Processing Method For Acoustic Emission/Microseismic Data Analysis, Charles Mborah

Doctoral Dissertations

"The acoustic emission/microseismic technique (AE/MS) has emerged as one of the most important techniques in recent decades and has found wide applications in different fields. Extraction of seismic event with precise timing is the first step and also the foundation for processing AE/MS signals. However, this process remains a challenging task for most AE/MS applications. The process has generally been performed by human analysts. However, manual processing is time consuming and subjective. These challenges continue to provide motivation for the search for new and innovative ways to improve the signal processing needs of the AE/MS technique. This research has developed …


Insulting Words: "They Are Animals!", Carolyn A. Ristau Jan 2018

Insulting Words: "They Are Animals!", Carolyn A. Ristau

Animal Sentience

As Chapman & Huffman state, creating divisive human categories has rationalized atrocities committed against the “other.” Labeling neighboring warring villagers as “animals” is considered a despicable insult. Yet contemporary scientific views of many animals grant them thinking and conscious faculties, and the capacity for impressive achievements, many unattainable by humans. Robots, too, can accomplish many similar feats. But the essential reason we must protect animals is not because of their admirable abilities, but their capacity for consciousness, for suffering. Robots are not conscious. Participants in the human-animal debate should not complain about changing criteria for determining human uniqueness. New and …


Micro-Scale Flood Hazard Assessment In Phnom Penh, Cambodia, Naichy Sea Jan 2018

Micro-Scale Flood Hazard Assessment In Phnom Penh, Cambodia, Naichy Sea

Chulalongkorn University Theses and Dissertations (Chula ETD)

Water-related disasters in urban area, especially urban floods have become more frequent and severe. This leads to loss of life, infrastructure damage, business interruption as well as difficulties in conducting daily activities. Phnom Penh, the capital city of Cambodia, has frequently experienced significant rainfall-flood events during rainy season. Without proper prevention and mitigation and management of urban drainage system, Phnom Penh is expected to confront with the current and future challenge of water-related disaster. To address this urban flood issue, flood modeling could be used to assess flood severity and make a visual representation of the urban flood hazard as …


Micro-Scale Flood Hazard Assessment In Phnom Penh, Cambodia, Naichy Sea Jan 2018

Micro-Scale Flood Hazard Assessment In Phnom Penh, Cambodia, Naichy Sea

Chulalongkorn University Theses and Dissertations (Chula ETD)

Water-related disasters in urban area, especially urban floods have become more frequent and severe. This leads to loss of life, infrastructure damage, business interruption as well as difficulties in conducting daily activities. Phnom Penh, the capital city of Cambodia, has frequently experienced significant rainfall-flood events during rainy season. Without proper prevention and mitigation and management of urban drainage system, Phnom Penh is expected to confront with the current and future challenge of water-related disaster. To address this urban flood issue, flood modeling could be used to assess flood severity and make a visual representation of the urban flood hazard as …


Investigation Of Ribbed Dome Including Tuned Mass Damper, Ali Parva Jan 2018

Investigation Of Ribbed Dome Including Tuned Mass Damper, Ali Parva

Civil & Environmental Engineering Master's Projects

This research report presents the outcome of an investigation of lightweight ribbed steel dome structure. The proposed ribbed dome structure is studied both numerically and experimentally under static, natural vibration, and base excitation conditions. The base excitation is considered in the form of a sinusoidal as well as seismic loading in the form of a scaled-down 1940 El Centro earthquake. A numerical study of the ribbed dome is also conducted including a tuned mass damper (TMD). The performance of the dome is also compared with that of a hexagonal vertical structure showing a superior response of the dome under seismic …