Risk Analysis Commons^™

General Hydrogeochemical Characterization Of Groundwater In Coastal Aquifers Of Kilwa Kisiwani Oceanic Island, South East Tanzania, Simon R Melchioly

Tanzania Journal of Engineering and Technology (TJET)

The main objective of this study was to determine the hydrogeochemical processes controlling the groundwater chemistry on the Island and assess its suitability for human consumption and irrigation. The methodology used in the study include hydrogeological assessment of the study area and laboratory analysis for general physico-chemical parameters of groundwater. Other parameters such as Soluble sodium percentage (SSP) or % Na+, Sodium Adsorption Ratio (SAR), Magnesium adsorption ratio (MAR), Residual sodium carbonate (RSC), hydrochemical facies classification, and Water Quality Index (WQI) were calculated using empirical formulae. The effects of salinization of groundwater were classified using the chloride-Bicarbonate (Cl/HCO3) and the …

Developing More Useful Equity Measurements For Flood-Risk Management, Adam Pollack, Casey Helgeson, Carolyn Kousky, Klaus Keller

Dartmouth Scholarship

Decision-makers increasingly invoke equity to motivate, design, implement and evaluate strategies for managing flood risks. Unfortunately, there is little guidance on how analysts can develop measurements that support these tasks. Here we analyse how equity can be defined and measured by surveying 167 peer-reviewed publications that explicitly state an interest in equity in the context of flood-risk management. Our main result is a taxonomy that systematizes how equity has been, and can be, defined and measured in flood-risk research. The taxonomy embodies how equity is a pluralistic and unavoidably ethical concept. Despite this, we find that most quantitative studies fail …

Assessment Of Risk Factors Related To Body Pain Complaints In Tanzania Construction Industry, Fatma K. Mohamed

Tanzania Journal of Engineering and Technology (TJET)

The construction industry is associated with risks that can result in musculoskeletal diseases. Although young male workers who are presumed to be healthy dominate the industry in Tanzania, body pain complaints have been widely reported. The aim of this study is to assess the prevalence and causes of body pains in workers. A cross-sectional study involving 396 workers was conducted. A chi square test was used for testing association of independent categorical variables and binary logistic regression analysis was used to determine predictors for body pain complaints. The results show that all study participants complained of at least one form …

Comparison Of Meteorological Drought Indices In Tanzania Using The Meteorological Drought Monitoring Software Package, Paul Ts Limbu

Tanzania Journal of Engineering and Technology (TJET)

Low precipitation, substantial evaporation, and an unequal distribution of precipitation throughout the area are the characteristics of drought, a climatic abnormality. This study used the Meteorological Drought Monitoring (MDM) software and monthly rainfall data from the Tanzania Meteorological Authority (TMA) to examine and compare the Deciles Index (DI), Standardised Precipitation Index (SPI), Percent of Normal Index (PNI), Rainfall Anomaly Index (RAI), Z-Score Index (ZSI), China-Z Index (CZI), and Modified China-Z Index (MCZI) for drought monitoring in Tanzania from 1988 to 2017. It was found that ZSI represented the dry years better than other indices, followed by DI, RAI, PNI, SPI, …

Study Of The Effects Of Thermal Aging Coupled With Shot-Peening Treatment Of Carbonitrided Din 1.6587 Low Alloy Steel On Retained Austenite And Residual Stresses, Richard J. Katemi

Tanzania Journal of Engineering and Technology (TJET)

This work investigated the effects of thermal aging and shot-peening of carbonitrided 1.6587 steel grade on retained austenite and residual stresses. After carbonitriding samples contained maximum of 0.87% carbon, 0.34% nitrogen and 50 mass. -% retained austenite. Thermal aging conditions investigated were -30°C, 90°C and 150°C while the aging period were 14, 96 and 720 hours. After thermal aging, some of the samples were subjected to shot-peening treatment using standard cut wire shots StD – G3 - 0.6 mm VDFI 8001 with intensity in the range of 0.25 to 0.30 mmA and coverage of 1.00 to 1.24 x 98%. It …

Causes And Consequences Of Inefficient Drilling And Blasting In Mine Development Headings: A Case Study Of Hard Rock Gold Mining Operations In Northern Tanzania, George Bennett

Tanzania Journal of Engineering and Technology (TJET)

Despite the introduction of the perimeter blasting technique at the Tulawaka Gold Mine, the mine continued to suffer from an overbreak of mine development headings, with an average overbreak of 24% every 22 m, which is approximately twice the acceptable 10% overbreak. The causes of this problem include ineffective drilling practices and uneven and excessive charging of explosives, resulting in a slightly high powder factor of 3.94 kg/m3 instead of 3.8 kg/m3, as per the design. The problem of overbreak resulted in ore dilution, a longer mine development cycle time and additional costs of approximately US$ 45 per cut, especially …

Predicting Hospitalization Risk Of Schizophrenia Patients In Missouri, Arun Kumar

Theses

Understanding the factors that contribute to the risk of hospitalization among individuals with schizophrenia is crucial for optimizing treatment strategies and improving patient outcomes. In this study, we used recent Medicaid adminis trative claims data in Missouri (from 2016 to 2019) and predicted the risk of hospitalization of patients diagnosed with Schizophrenia (N=143446). We ana lyzed the association between previous hospitalizations and the likelihood of future hospitalizations. We developed machine learning techniques, including logistic re gression and decision tree classifiers, to predict the risk of hospitalization based on demographic factors, clinical variables, and historical hospitalization records. Our findings reveal that …

Safety Evaluation Of Hawaii Dot Modified Type A-1 Flared Buried In Backslope Guardrail End Terminal, Sina Changizian

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The Hawaii Department of Transportation (HDOT) desired to evaluate the crashworthiness of a guardrail end terminal design in which the upstream guardrail anchorage was connected to a block partially buried in a cut slope, known as a “Buried in Backslope” or BIB design. The HDOT BIB system used an upper W-beam with 8-in. deep blockouts attached to W6x9 steel posts and a lower W-beam rubrail located 3 in. below the upper rail. The system used two horizontal flares: 7.4:1 near the upstream anchor block and a 13:1 flare through the ditch.

Critical impact points (CIPs) were identified and recommended for …

Sustainable Water Treatment Systems In The La Vega Region Of The Dominican Republic, Hannah Fulton, Justina Thomae, Jorge Del Angel, Ramin Ansari, Karina Peate, Rylan Elliott, Adam Spieth, Thalia May, Morgan Jung, Ernest R. Blatchley Iii, Rebecca C. Johnson

Graduate Industrial Research Symposium

Purdue University's service-learning course, Water Supply in Developing Countries (WSDC) is dedicated to ensuring access to safe drinking water in the La Vega region of the Dominican Republic. The focus in the current academic year is to enhance the functionality, sustainability, and independence of community-based water treatment systems installed by previous WSDC students. Despite the construction of four water systems since 2012, operational challenges ensued, rendering them currently inoperable. Our objective is to learn from past mistakes, restore the systems and ensure their continuous functionality. During the fall semester, class members assessed repair needs in two communities with existing systems, …

Data-Driven Approaches For Enhancing Power Grid Reliability, Behrouz Sohrabi

Electronic Theses and Dissertations

This thesis explores the transformative potential of data-driven approaches in addressing key operational and reliability issues in power systems. The first part of this thesis addresses a prevalent problem in power distribution networks: the accurate identification of load phases. This study develops a data-driven model leveraging consumption measurements from smart meters and corresponding substation data to reconstruct topology information in low-voltage distribution networks. The proposed model is extensively tested using a dataset with more than 5,000 real load profiles, demonstrating satisfactory performance for large-scale networks. The second part of the thesis pivots to a crucial safety concern: the risk and …

Optimizing Hub And Spoke Selections For Adaptive Basing In Agile Combat Employment, Alan Heng

Theses and Dissertations

Advancing technologies and emerging competitors within the Indo-Pacific region have rendered the use of fixed installations for United States Air Force (USAF) operations less than optimal for generating airpower. The adoption of Agile Combat Employment (ACE) is imperative and emphasizes a hub-and-spoke model. However, the methodology for selection of contingency locations remains undecided. Current selection of optimal sites hinges on an optimization framework, employing either rank-based or mathematical approaches that consider various criteria to assess and quantify each location. These criteria are then addressed through objectives and constraints, forming the basis for an effective decision-making process. This paper introduces two …

Analyzing Cost Risk In Department Of Defense Program Office Estimates, Todd L. Millard

Theses and Dissertations

This research studies cost risk for Department of Defense (DoD) acquisition programs during development and has three overarching objectives: 1) analyze the degree of change in cost risk (quantified as risk dollars) as programs mature, 2) analyze the accuracy of cost risk estimates (quantified as risk error) as programs progress, and 3) adopt risk analysis techniques common in the commercial banking industry to analyze cost risk in DoD programs. For the first objective, some evidence of significant positive trends in relative risk dollars is found for ACAT 1, 2, and 3 programs. For the second objective, there is no strong …

Root Cause Analysis For Troop Construction Schedule Delays And Cost Overruns, Richard H. Wilkens

Theses and Dissertations

Troop construction can be an effective tool when a project is simple enough to execute projects in a timely and cost effective manner. However, underlying variables plague these projects causing them to miss anticipated deadlines which in return could make them more costly. Significant variables that convey impact to cost and schedule are Equipment Operating Issues, Edits During Construction, Design Flaws, Lack of Communication, Poor User Coordination, Improper Documentation, Inaccurate Submittals, Low Quality Control, and Lack of Experience. Project engineers and project managers must provide effective continuity as well as improve their own competence and situational awareness to effectively mitigate …

Standardization Of Risk Classifications For Unmanned Space Vehicle Missions, Collin A. Gwaltney

Theses and Dissertations

This paper seeks to model risk classification levels (A-D) for 122 Space Vehicle programs. Models include multinomial logistic regression as well as random forest, a machine learning technique based on decision trees. We use independent variables (IVs) which are theoretically correlated to risk class for the regression and one random forest model. We then include all IVs and allow the random forest technique to use those which provide the most information on risk class before paring down the number of IVs to only 7. We show that the accuracy of predictions increases from 62% to 87% by using random forest …

Radiological Decontamination Methodologies On Litter-Bound Patients In Arctic Environments, And The Associated Airborne Risks Posed To First Responders, Juan S. Alb

Theses and Dissertations

This study was conducted to determine if air-based decontamination (decon) methods would be effective at both treating patients exposed to dry, radiological contamination as well as reducing its re-aerosolization during the disrobing process, such that these methods could be applied on litter-bound patients in extreme cold environments. A litter-bound, full-size mannequin dressed in a set of standard military issue extreme cold weather jacket and pants coated in 27 g (1 Tbs) of Copper Oxide (density 6.315 g/cm³ ) was given one of three treatments for dry aerosol decon. The three cleaning treatments included high-efficiency particulate air (HEPA) vacuum, a …

Evaluation Of Environmental Management System For Small And Medium Enterprises In Dar Es Salaam, Tanzania, Juma M. Matindana

Tanzania Journal of Engineering and Technology (TJET)

A system that manages environmental issues of Small and Medium Enterprises (SMEs) from the time of acquisition of raw materials up to disposal of the product is not well clear, especially in Tanzania. Most of the studies have been conducted in the field of environment management but few of them address the evaluation of the management of SMEs activities with respect to the environment. Although the nature of activities of SMEs has little noticeable environmental implications at the individual level but the impact is large due to diversification and labour intensity of these SMEs. SMEs employ about 20% of the …

Reliability Improvement In The Traction System Of Tanzania Standard Gauge Railway, Yusufu Katuga

Tanzania Journal of Engineering and Technology (TJET)

In recent years, many African governments have been developing Standard Gauge Railway (SGR) to replace the old after becoming absolute, inefficient Meter Gauge System (MGR) to carry more loads at high mileage and speed while combating the oil and environmental crises. With the increase of SGR, the amount of traction systems has grown sharply, the service life of the traction system has increased gradually, and the components of the vehicle traction system have become worn and aged as a result. While Tanzania is transitioning to SGR with its gradually increasing traction systems, reliability improvement becomes a key for the sustainability …

An Overview Of Maternity Healthcare Monitoring In Developing Nations, Godphrey Kyambille

Tanzania Journal of Engineering and Technology (TJET)

A healthcare monitoring arrangement is essential for frequently monitoring a patient's health status. Specifically, maternal healthcare systems for tracking are utilized to evaluate the clinical status and monitor any abnormal condition changes during all three trimesters. This paper's objective is to conduct an extensive literature review and acknowledge earlier initiatives and studies conducted previously in maternal health care monitoring. This review focuses on accumulating information from earlier work and presents a general overview of previous studies concerning maternal health care monitoring (MHCM). The paper focuses on the maternal healthcare systems in developing countries accessed by pregnant women during the antenatal …

Sustainability Of Simplified Sewer Systems: A Case Study Of Vingunguti Urban Settlement, Dar Es Salaam Region In Tanzania, Neema Kijazi

Tanzania Journal of Engineering and Technology (TJET)

The universal access to safely managed sanitation remains one of the challenges to achieving the UN SDG target 6.2 in unplanned urban settlements including the Vingunguti area in Dar es Salaam City which is high-density populated. In an attempt to address this challenge, a simplified sewer system was piloted as an option for achieving safely managed sanitation in this particular area. The objective of this study was to assess the sustainability of the piloted simplified sewer system for its potentiality to up-scale and replication in areas with similar sanitation challenges in the country. Methodology involved collection of data on performance …

Going Airborne: Kent State's Pioneering Leap Into Integrated Advanced Air Mobility, Jason T. Lorenzon

National Training Aircraft Symposium (NTAS)

This proposal centers on the development of a Concept of Operations in Advanced Air Mobility (AAM). Kent State University's College of Aeronautics and Engineering is poised to pioneer the integration of drones and electric Vertical Takeoff and Landing (eVTOL) systems, bridging the gap between its campus and airport by transporting students and faculty the 3NM distance from campus to the airport and back by a UAV. Beyond a standard research initiative, this proposal signifies a groundbreaking effort to reshape the landscape of educational aeronautics and Advanced Air Mobility and Urban Air Mobility. Our overarching goal is to transcend conventional boundaries …