Engineering 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 …

Experimental And Numerical Studies On The Compressive Strength Test Of Recycled Aggregate Concrete Using Digital Image Correlation, Bastian Okto Bangkit Sentosa, Joshua Ferdinand, Nuraziz Handika

Makara Journal of Technology

The utilization of recycled aggregate (RA) as substitute of natural aggregate in concrete contributes to the research of sustainable building construction materials. Many applications of RA have been studied worldwide. However, the application of RA with a specific range of strength and specific damage behavior requires further study. This research aims to examine the mechanical characteristics of RA concrete, particularly its load–displacement response and crack pattern, through the experimental and numerical studies of compressive strength test. Laboratory concrete waste from cylindrical sample with 30–35 MPa strength was chosen as RA. The digital image correlation (DIC) method was applied throughout 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 …

Hybrid Method Neighbor Node Discovery In Wireless Sensor Networks: A Framework, Sagar Mekala, Shahu Chatrapati Kaila, Jyothi Rani Matang

Makara Journal of Technology

Wireless devices are now being adapted for diverse purposes, such as healthcare, agriculture, transportation, and tactical operations, which present challenges in network formation owing to high device mobility. Current methods rely on discovery techniques for forming wireless sensor networks (WSNs); however, the existing research has been criticized for its high time complexity and redundant neighbor discovery process. In this study, we provide a hybrid strategy to effectively handle the difficulties of locating neighboring nodes in WSNs. Our method combines several strategies to produce precise and effective neighbor detection. Herein, shared memory–based discovery, a beacon technique, and range and distance overlap …

Sediment Characteristics And Hydrocarbon Composition Of Makukwa Seep In Southern Tanzania: Potential Implications For Subterranean Hydrocarbon Accumulation, Makungu M. Madirisha

Tanzania Journal of Engineering and Technology (TJET)

Exploring the interplay between natural seeps and nearby sediment and hydrocarbon properties is key to unlocking subsurface hydrocarbon potential. This study presents findings on the hydrocarbon composition and sediment characteristics of the Makukwa seep in southern Tanzania, providing insight into subterranean hydrocarbon accumulation. Sediment analysis across areas A and B, located approximately 20 m apart, showed a decrease in porosity with depth, indicative of typical sandstone formations. Area A, near the seeps, exhibited porosity ranging from 23% to 36%, whereas Area B, further away, showed porosity ranging from 22% to 38%. This suggests that a lower cretaceous sandstone layer may …

Optimal Load Shedding During Service Restoration In Electrical Secondary Distribution Network Based On Reinforcement Learning, Rukia J. Mwifunyi

Tanzania Journal of Engineering and Technology (TJET)

Increased stress in traditional power systems results in blackouts due to voltage instability attributed to a mismatch between available capacity and load demand, especially in distribution networks. Service restoration schemes are designed to return power supply to the affected parts of the networks. The availability of insufficient supply is a complex problem that requires operational experience or an automatic system. The stochastic nature of load demand significantly impacts service restoration as it results in increased restored demand in case a fault occurs during off-peak hours and helps reduce overload if the fault occurs during peak hours. The study adopts an …

Production Of Biofertilizer From Fruit And Garden Waste, Neema Msuya

Tanzania Journal of Engineering and Technology (TJET)

The project focused on the production of bio-fertilizer from fruit and garden waste, with a specific emphasis on utilizing pineapple tops in the composting process. The objective was to produce and assess the properties of the bio fertilizer obtained from this process and evaluate its potential application in agriculture. In this study, the composting process was done in a 0.7 m long, 0.85 wide and 1.1 m high vessel, and 0.238 m3 pineapple top wastes, resulting in 0.35 m3 of biofertilizer. The bio fertilizer produced exhibited favorable characteristics, including a moisture content of 36%, pH of 7.1, and a total …

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 …

Synthesis Of Local Control Systems For Underwater Units Cleaning Bottom Sediments In Reservoirs, Yuriy Gennadiyevich Shipulin, Zebiniso Akmalovna Zayniddinova

Chemical Technology, Control and Management

The article discusses the issues of synthesizing local control systems for underwater units for cleaning bottom sediments in reservoirs. It is shown that the protection and rational use of natural reservoirs and the fight against their premature siltation is becoming an urgent task.

It is proposed to use small-sized underwater units, consisting of information and measuring devices, to carry out search work for cleaning bottom sediments under water; control systems; actuators and means of communication with humans.

It is shown that the task of controlling the loading of an underwater unit (UU) requires maintaining optimal performance while simultaneously taking into …

Information Model Based On Parameters Of A Combined Soil Preparation Until For Planting, Azmuddin Sadriddinov, Anvar Abdazimov, Faxraddin Mavlanov, Hursand Madrakhim Ugli Rakhimov

Technical science and innovation

The article describes in detail the development of a combined pre-sowing machine as a result of the literature analysis of the scientific research conducted on pre-sowing tillage machines and its use and working process. In addition, the article provides scientifically based information about the factors affecting the leveler-softener and previous work on their improvement. The current state of tillage before planting in Uzbekistan and the size of the tilled fields are studied and tabulated. In order to optimize the parameters of the developed machine and minimize costs, as well as to increase its efficiency, it is devoted to the creation …

Modernization Of Water Flow Measurement In Open Irrigation Systems Using The Slope-Area Method, R.M. Aliev, Djalilov Anvar

Chemical Technology, Control and Management

This article describes two methods for determining water flow in open irrigation systems: “speed - area” and “slope - area”. The authors considered the problem of its modernization using the existing method for determining water flow “slope - area” in open irrigation systems. The essence of the issue is the remote transfer of parameters necessary for calculating water flow in open irrigation systems and improving the means of their processing. In scientific studies conducted by the authors, the required hydraulic parameters were studied using the “slope - area” and “speed - area” water flow methods. Based on experimentally obtained data, …

Synthesis Algorithm Of Control System Based On Neural Network For The Gas And Oil Process, Jasur Sevinov, Abdishukurov Maqsudovich Shavkat, A.Z. Shodiyorov

Chemical Technology, Control and Management

Automatic control systems in the oil and gas processing are considered. After extraction of natural gas condensate, management of technological parameters plays an important role in its processing. Among the parameter of regulating algorithms, control based on neural network technology was considered. These control systems are created on the basis of algorithms of neural network technology. There are several structures of neural networks according to their structure. Differences in the process of information processing of these branching structures are considered.

Effects Of Bending And Re-Bending On Mechanical Properties Of Locally-Manufactured Steel Rebars, Patrick W. Waruhiu, Simon I. Marandu, Mussa I. Mgwatu

Tanzania Journal of Science

Steel rebars experience deformation when subjected to bending and re-bending operations. Subsequently, their microstructures are impaired thus affecting the mechanical properties and leading to failure. This study establishes the effects of bending and re-bending the steel rebars on the mechanical properties. Experiments were conducted to determine the effects of bending and re-bending of the steel rebars. Testing was conducted on Ten virgin and Thirty specimens which were bent and re-bent at 45º, 90º, and 180º, and followed by tensile tests. Yield strength, ultimate tensile strength, elongation, and ultimate tensile strength to yield strength ratio (Rm/Re), were recorded. Results showed the …

Characterizing Brain And Skull Mechanics In The Minipig Using Magnetic Resonance Elastography, Shuaihu Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Computational models and simulation are important tools to investigate the mechanisms underlying traumatic brain injury (TBI); their accuracy depends strongly on accurate model parameters, including the mechanical properties of the brain and its interactions with the skull. However, most existing TBI modeling studies are performed using material properties derived from animal tissue obtained after death. Magnetic resonance elastography (MRE) provides a non-invasive method for estimating the mechanical properties of soft tissue. The overall objective of this thesis is to characterize the biomechanical properties of brain tissue and brain-skull interface in the minipig by using MRE. This was achieved through pursuit …

Improving Technology For Producing Complex Fertilizer From Low-Grade Phosphorites Of The Central Kyzylkum, A.Zh. Allamuratova, A.U. Erkaev, A.M. Reimov, Saparbay Kazakhbaev, Dilshodbek Kurbiyazov

Chemical Technology, Control and Management

The methods of nitric acid processing of phosphate raw materials are analyzed. A technology has been developed for the nitric acid processing of phosphate raw materials into nitrogen-phosphorus fertilizer with the implementation of the process in a condensed pulp by adding sulfuric acid. A technology for producing complex fertilizers with a wide range of N:P₂O₅:K₂O ratios with improved physico-chemical parameters due to the introduction of various potassium salts into the process is proposed.

Results Of Experimental Study Of Solar Collector Efficiency, Shakhnoza Sultanova, Ajargul Mambetsheripova, Jasur Safarov

Chemical Technology, Control and Management

The article considers the influence of ambient temperature on the drying efficiency depending on the incident solar radiation, changes in the average temperature of the absorber plate depending on the absorbed power, as well as the thermal efficiency of the collector at significant values of coolant flow.

Features Of Magnetoelastic Converters Of Mechanical Quantities Of Transformer Type, Sulton Amirov, Kamila Jurayeva

Chemical Technology, Control and Management

The article discusses the features of a magnetoelastic transformer type transducer. In magnetoelastic transformer-type transducers, mutual inductance is assumed as a variable value, which is a function of the value of the applied mechanical force. Hence, the transformation coefficients of such converters are also variable. There are also choke type converters in which a change in the magnetic permeability of the magnetic circuit leads to a change in the total electrical resistance of the choke. For further research, transformer-type converters were selected, which make it possible to widely implement techniques for improving basic characteristics.

Dynamic Characteristics Of Magnetoelectric Linear Actuators Of Control Systems, Мakhmudjon Muxamedovich Аbdullayev, Rasul Ernazar Ogli Abdiev

Chemical Technology, Control and Management

This paper presents the results of studies carried out on magnetoelectric drives that carry out linear movement, models of drives are built and, on their basis, studies of the main indicators associated with the movement of a linear armature are carried out, such as: speed of movement, acceleration, current values, voltage and traction force of the armature. Also presented are the results of a study of magnetoelectric linear motion drives based on an analysis of graphs of their dynamic characteristics.

Algorithms For Structural Synthesis Of Control Systems For Dynamic Objects Under Conditions Of Unmeasurable Disturbances, Husan Zakirovich Igamberdiev, Uktam Farkhodovich Mamirov, Bunyod Mamurjon Ugli Buronov

Chemical Technology, Control and Management

The paper talks about ways to use inverse dynamic models to structure a control system for moving objects when disturbances are not measured. To solve the main problems that arise when implementing the inverse dynamic model method, methods for synthesizing inverse systems with given dynamic characteristics are used. The solution to this problem is obtained based on the theory that dynamic observers are invariant to unmeasured input influences. We broke down the matrix operator on the right into elementary orthogonal rotation matrices and on the left into permutation matrices to get a stable answer to the equation of the current …

Artificial Neural Network Based Grain Moisture Measuring Device, Erkin Eljaev, Shohrux Nurali O‘G‘Li Narzullayev, Elyor Faxriddinovich Khudoyberdiev

Chemical Technology, Control and Management

To date, the intellectualization of solving technical issues in managing, controlling, and measuring technological processes in all branches of industrial production is considered an urgent task. In this regard, a class of intelligent devices and sensors has emerged. Intelligent devices and sensors differ from their analog counterparts in that they have functions such as automatic adjustment of the measurement range, self-calibration, data processing, and decision-making. The article discusses the development of intelligent measuring instruments based on a capacitive transducer for measuring the moisture content of grain and grain products.

Building Software At Scale: Understanding Productivity As A Product Of Software Engineering Intrinsic Factors, Gauthier Ingende Wa Boway

Master's Theses

During our education at KSU, we have learned about various factors that affect productivity such as schedule, budget, and risks, but those are often controlled outside of what we could learn as software engineering principles, patterns, or practices. On top of that, other off-work factors such as health conditions, emotional distress, or political climate, just to name a few, could drastically affect the productivity of a software engineering team. We see a demarcation between those factors that affect productivity in software engineering but are not inherent to the discipline itself, which we call resistance factors, and the factors that are …

Assessing The Cooling/Lubricating Agencies For Sustainable Alternatives During Machining Of Nimonic 80: Economic And Environmental Impacts, Mayur A. Makhesana, Harsh Vesuwala, Kaushik M. Patel, Ana Vafadar, Murat Sarikaya, Navneet Khanna

Research outputs 2022 to 2026

Developing sustainable manufacturing methods that balance environmental and economic aspects is challenging. A comprehensive analysis of the economics of machining and carbon emissions is essential to encourage adopting sustainable practices. This work presents the machinability and comparative sustainability analysis of Nimonic 80 superalloy when it is machined utilizing a novel, environmentally friendly vegetable oil-based hybrid nanofluid-minimum quantity lubrication (MQL) and liquid carbon dioxide (LCO2) technique. The main objective is to comprehend the efficacy of the proposed approach on tool life, surface roughness, power consumption, total machining costs, and carbon emissions. Compared to other machining conditions, the use of hybrid nanofluid-MQL …

Supporting Text And Data Analysis Across Campus From The Academic Library, Amy Kirchhoff, Hejin Shin Phd

Digital Initiatives Symposium

The ability to comprehend and communicate with text-based data is essential to future success in academics and employment, as evidenced in a recent survey from Bloomberg Research Services which shows that nearly 97% of survey respondents now use data analytics in their companies and 58% consider data and text mining a business analytics tool (https://www.sas.com/content/dam/SAS/bp_de/doc/studie/ba-st-the-current-state-of-business-analytics-2317022.pdf). This has fueled a substantial growth in text analysis research (involving the use of technology to analyze un- and semi-structured text data for valuable insights, trends, and patterns) across disciplines and a corresponding demand on academic libraries to support text analysis pedagogy and text analysis …

Evaluating The Impact Of Hybrid Ventilation Strategies On Reducing The Cooling Load And Achieving Thermal Comfort Of Buildings: Regarding Arid Climate Of Uae By, Sheikha Mohammed Al Niyadi

Thesis/ Dissertation Defenses

The hybrid ventilation system has demonstrated significant promise in controlling indoor thermal comfort, maintaining indoor air quality, and using the least amount of energy possible. It accomplishes this by combining natural and mechanical ventilation. When natural ventilation is not possible, this system seamlessly switches to mechanical ventilation to maintain the best possible indoor thermal comfort levels. However, implementing this method in extremely dry regions is challenging due to the high energy consumption associated with air conditioning and cooling consume during the summer. In these regions, air conditioning and cooling alone account for approximately 60% of the urban energy use. The …

Valorization Of The Polymeric Constituents In Plastic Wastes Through Thermo-Chemical Processes By Using Viable Metal Oxides Additives, Labeeb Ali

Thesis/ Dissertation Defenses

The rapid accumulation of different types of plastic waste necessitates the development of effective and economically viable waste management operations. Such a process should ideally not only mitigate associated environmental burdens but also recycle and recover value-added products. Through incineration or pyrolysis, thermal processing has emerged as a mainstream approach to waste management of the ever-increasing loads of different categorized plastic wastes. Throughout the work of the thesis, we have utilized a multitude of complementary techniques spanning material characterizations, catalysis, kinetic modelling, and density functional theory (DFT) to comprehend the complex chemistry that underpins catalytic chemical recycling of plastic wastes. …

Study Of Kinetics Of Hydrocarbon Gas Purification With Composite Absorbents, Oybek Aripdjanov, Shavkat Nurullaev, Shodiyakhon Azimova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work is to improve the process of natural gas purification from acidic components using a composite absorbent. To study the sorption of acidic components in the gas composition, a chromatographic analysis method was used. The kinetics and rate of corrosion of carbon steel grade st.10 when using composite absorbents MDEA +DEA + AVRP have been studied. The results of the study show that the volume of absorption increased from 0.55 mol/mol to 0.65 mol/mol, and the amount of H₂S in the purified gas decreased from 0.022 g/m³ to 0.014 g/m³. Corrosion …

Study Of Reactive Distillation Equipment For Eterification Process, Abbos Elmanov, Abdulaziz Bakhtiyorov, Adham Norkobilov, Olimjon Maksudov, Zarif Oripov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this work is to study the chemical technological processes for eterification processes, and the reactive distillation unit, which carries out the reaction and separation process in one device, was chosen as the object of research. А reаctive distillаtion system is exаmined to produce for the production of Ethyl Acetate (EtAc) viа eterificаtion of acetic acid (HAc) with ethаnol. Optimizаtion methods using sensitivity analysis аre аlso conducted. Cаlculаtion of vаpor liquid equilibrium of the mixture system is done using UNIFАC model. Heat integration from the distillate stream of the column to the acid feed stream and from bottom …

Modeling And Performance Analysis Of Solid Oxide Fuel Cell, Mariya Pecherskaya, Khakimjan Butanov, Suhrob A. Ibodullaev, Olim Ruzimuradov, Shavkat Mamatkulov

CHEMISTRY AND CHEMICAL ENGINEERING

A three-dimensional numerical model of the system configurations of various types of solid oxide fuel cells (SOFCs) is used and the effect of parameters on SOFC performance is numerically investigated using COMSOL Multiphysics. The effect of parameters such as support layer thickness, operating temperature, and electrode porosity are shown in the polarization and power curves for each model. The results of the study showed the advantages of the anode-supported SOFC compared to cathode- and electrolyte-supported SOFC.

Theoretical calculations demonstrate the highest output power density in the anode-supported SOFC at 900 ℃, and reach a value of 0.585 W cm^{-2 …}