Applied Mathematics Commons^™

Optimization Pump As Turbine Coupled To A Self-Excited Induction Generator Using Multi-Objective Genetic Algorithm, Emanuel J. Nyirenda

Tanzania Journal of Engineering and Technology (TJET)

As a way of accelerating the deployment of affordable and clean renewable energy generation technologies, applying a pump working as a turbine coupled to a self-excited induction generator is gaining popularity in various areas including energy recovery and micro hydro systems. However, it is currently challenging to predict the performance of the PAT-SEIG system and there is no agreed-upon rule on the selection of the appropriate system to be installed at a particular site. This paper has presented multi-objective optimization to select the best operating point of the PAT-SEIG system. The results show that the peak efficiencies for the PAT …

Evaluation Of Cybersecurity In Remote Working Settings For Mobile Network Operators, Victoria Mahabi

Tanzania Journal of Engineering and Technology (TJET)

Cybersecurity has increasingly been a primary concern to people as technology advances and allows them to work remotely. This study thus evaluated the cybersecurity posture for organisations that have opted for remote working culture, whereas emerging cyber threats, practices to combat them, and appropriate guidelines for managing cyber threats were discussed. The study used a descriptive design with a quantitative approach from 118 information technology personnel working for Tanzania's three major mobile network operators (MNOs). SPSS analysed the collected data. The study revealed that predominant cyber-threats affecting MNOs in remote working include human errors, phishing attacks, malicious domains, denial of …

Sol-Gel Synthesis And Microstructure Characterization Of Nio-Tio2 Semiconductor, Godlisten N. Shao

Tanzania Journal of Engineering and Technology (TJET)

NiO-TiO2 is a fascinating p-n semiconducting binary metal oxide with unique electronic and optical properties. The NiO-TiO2 has been synthesized using complicated preparation methods and expensive precursors that hamper their large-scale production. The present study reports the preparation of NiO-TiO2 semiconductor with improved physicochemical properties. NiO-TiO2 samples were prepared through one-pot sol-gel synthesis process followed by sintering of the as-synthesized materials at temperatures ranging from 600 to 1000 °C. The role of thermal treatment and NiO content on the microstructures was exquisitely studied. The microstructure of the NiO-TiO2 samples was examined by Raman spectroscopy, XRD, XRF, SEM-EDAX, high resolution TEM, …

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 …

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 …

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 …

A 2-D Numerical Model For Evaluating Daylight Penetration In Short Tunnels For Enhanced Driver Safety, Joachim James

Master's Theses

It is commonly assumed that daylight will adequately penetrate short tunnels, leading to the misconception that artificial lighting is unnecessary during the daytime. Past studies revealed higher frequency of crashes in short tunnels and despite that there is lack of national guidelines warranting artificial lighting for short tunnels. Inadequately lit tunnels pose safety risks, while excessive lighting can be costly. Hence, it becomes crucial to investigate the extent of daylight penetration in short tunnels and identify disappearance zones within these tunnels. This research can help determine the necessity of artificial lighting, and which specific areas of the tunnel require lighting. …

Mathematical Modeling For Dental Decay Prevention In Children And Adolescents, Mahdiyeh Soltaninejad

Dissertations

The high prevalence of dental caries among children and adolescents, especially those from lower socio-economic backgrounds, is a significant nationwide health concern. Early prevention, such as dental sealants and fluoride varnish (FV), is essential, but access to this care remains limited and disparate. In this research, a national dataset is utilized to assess sealants' reach and effectiveness in preventing tooth decay, particularly focusing on 2nd molars that emerge during early adolescence, a current gap in the knowledge base. FV is recommended to be delivered during medical well-child visits to children who are not seeing a dentist. Challenges and facilitators in …

Exploration Of Characteristic Curve In Fox Float 3 Shock Dampers To Expedite Shock Damp Tuning., Joshua R. Moore

Honors College Theses

The shock absorber is an integral part of a vehicle suspension system and has a strong influence on its performance, especially in the case of motorsports. It is important to study the force versus velocity relationship, commonly known as the characteristic curve of the shock absorber both during compression and rebound. Vendor-supplied characteristics often reflect the behavior of the shock absorber in a particular setting. However, during the installation, the settings inside the shock absorber are adjusted to increase the human comfort level and performance of the vehicle. This may change the characteristic curve of the shock. The available data …

Localized Collocation Meshless Method For Modeling Transdermal Pharmacokinetics In Multiphase Skin Structures, Eduardo Divo

Math Department Colloquium Series

The human skin has a complicated structure with many multi-scale, biophysical effects impacting the propagation of skin-injected substances, such as partitioning, metabolic reactions, adsorption and elimination. An extended version of Fick’s second law governing the process of the compound diffusion in various skin layer is employed in the current work by considering the conservation of mass of the substance and the metabolic reaction of the substance in viable skin. Additionally, a model assuming linear coupling between the substance concentrations that are bound and unbound with blood was developed. Using such a model, a set of coupled partial differential equations are …

Enhancing Rotating Machinery Fault Diagnosis: A Dual-Head Attention Mechanism In Deep Learning Neural Networks, Qing Snyder

Dissertations

Rotating machinery is crucial to production efficiency and safety in manufacturing industries for an extended time. Ensuring machinery reliability necessitates effective diagnostic systems, particularly for rotating bearings, the key components of such equipment. Fault diagnosis in rotating machinery is essential to prevent failures and minimize downtime, thereby playing an important role in industrial operations. The application of advanced neural network techniques in industry has risen recently. Among these, attention-based neural networks, especially the Transformer models, are originally noteworthy for their sequential data handling capability. This research delves into attention-based algorithms for rotating machinery fault diagnosis, signifying a substantial advancement in …

Analyzing The Influence Of Design And Operating Conditions On Combustion And Emissions In Premixed Turbulent Flames: A Comprehensive Review, Medhat Elkelawy Prof. Dr. Eng., E. A. El Shenawy Prof. Dr., Hagar Alm-Eldin Bastawissi, Ibrahim Ali Mousa Eng., Mohamed M. Abdel-Raouf Ibrahim Dr. Eng.

Journal of Engineering Research

Recently, premixed combustion has dominated the field of combustion research worldwide. The current work is a review that addresses the effects of design and operating regimes on the combustion and emission characteristics of premixed turbulent flames. The study accounts for recent developments aimed at overcoming combustor operability issues that influence emissions and flame stability. Various experimental setups have been utilized in investigations, with results pertaining to performance and emissions concerning premixed turbulent flames. Thus, the objective of this paper is to provide a comprehensive review of the effects of swirl vane angles and equivalence fuel-air ratios for tests conducted both …

Building For Safety: Design Considerations For Refuge Areas In Tall Buildings From Quality Management Perspective, Enass. A. Salama, Heba. M. Gaber, Ahmed. M. Selim

Journal of Engineering Research

New El Alamein City is one of the largest urban projects in Egypt, and the largest project on the north coast. Tall buildings (super high-rise buildings) are considered the prevailing trend by architectural designers to obtain the maximum view of the Mediterranean Sea. The provision of safety evacuation in emergencies for these buildings’ occupants is a crucial challenge from the Quality management point of view. In contrast, there are no sufficient architectural design guidelines for the tall buildings provided by the Egyptian code for protecting buildings from fire, especially the design of the refuge areas. This study aims to investigate …

Effect Of Organic Compounds Additives For Biodiesel Fuel Blends On Diesel Engine Vibrations And Noise Characteristics, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi Prof. Dr. Eng., E. A. El Shenawy Prof. Dr., Mahmoud Soliman Eng.

Journal of Engineering Research

The extensive consumption of petroleum fuel directly correlates with both hazardous exhaust emissions affecting human health and contributing to global warming. Initially, biodiesel fuels were proposed as a viable alternative to address these issues. This perspective finds support in numerous published studies that highlight how the significant catalytic effect of nanoparticles allows for their integration into biodiesel blends, resulting in improved combustion characteristics, reduced exhaust emissions, and enhanced performance. This study investigates the impact of additives on biodiesel fuel properties and its effects on engine performance metrics such as brake power, brake thermal efficiency, exhaust gas concentration, engine vibration, and …

Investigation Into The Impact Of Ammonia Hydroxide On Performance And Emissions In Compression Ignition Engines Utilizing Diesel/Biodiesel Blends, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi, Mohammed Osama Elsamadony Dr. Eng., Abdallah Salem Abdalhadi

Journal of Engineering Research

In recent times, there has been a surge in scientific endeavors aimed at combating global warming. Various methods have been employed to address this issue, including the substitution of fossil fuels with more environmentally sustainable alternatives and the combination of different fuel types. This can be achieved through the integration of innovative injection systems and the simultaneous combustion of alternative fuels alongside fossil fuels, or by modifying fuel injection systems such as in the PCCI, RCCI, or HCCI systems. In a particular research investigation, a blend of ammonia hydroxide and diesel, with volume percentages of 7.5% and 92.5% respectively, was …

Enhancing Diesel Engine Performance By Directly Injecting Blends Of Ammonium Hydroxide And Including Liquid Petroleum Gas As A Partially Premixed Charge, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi, Mohammed Osama Elsamadony Dr. Eng., Abdallah Salem Abdalhadi

Journal of Engineering Research

Recently, scientists have made significant strides in addressing or mitigating environmental issues. Researchers have adopted various approaches to tackle these issues, such as replacing fossil fuels with more environmentally friendly alternatives or blending multiple fuel types. This can be achieved by either integrating these two trends through the use of new injection systems and simultaneous combustion of alternative fuels with fossil fuels or by modifying fuel injection systems, exemplified by the PCCI, RCCI, or HCCI systems. Consequently, these methods have proven effective in reducing environmental pollutants, enhancing thermal efficiency, and decreasing specific fuel consumption. In this study, ammonia hydroxide and …

Experimental Investigation On Combustion And Emission Characteristics Of Co-Combustion Of Pulverized Biomass With Diesel Fuel In An Industrial Burner, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi, Ahmed Abou El-Yazied Prof. Dr., Saad El-Malla Dr. Eng.

Journal of Engineering Research

This study presents the combustion and emission results obtained from a laboratory furnace equipped with a 35 kW industrial burner that utilizes co-combustion of pulverized biomass and diesel fuel. The experiment compared the co-combustion of pulverized biomass and diesel fuel with diesel fuel alone. Three different loading ratios of pulverized biomass from residual beet samples were used. Temperatures were measured at various positions inside the furnace to analyze combustion performance. It was observed that increasing the biomass loading ratios led to higher flame temperatures and improved combustion compared to diesel fuel alone. The concentrations of pollutants such as Co, HC, …

Cfd Study On Two-Phase Flow Patterns In A Pipe With 90º Elbow In Different Operating Conditions, Hagar Alm-Eldin Bastawissi, Mohammed Ahmed Khafagy, E. A. El Shenawy Prof. Dr., Ahmed M. Salem Dr

Journal of Engineering Research

Recently, CFD has offered a technological solution for modelling multi-phase flow in which we can make endless simulations with reduced expenses and effort in high accuracy results; we shall also mention that experimental studies have limitations for safety considerations when experimenting with flow in high temperature or pressure values or medium nature as in nuclear or chemical flows.In this paper, we used the ANSYS FLUENT CFD program to simulate the two-phase flow in a pipe to study the effect of attaching a 90-degree elbow fitting to the piping system, seeking to find out the change in the pattern and resulting …

تقنيات الاضاءة الصناعية وتأثيرها فى الفراغ السكنى على السلوك الانسانى, Samah Kamal Elfeky, Walaa Ahmad Nour, Lobna Abdelfatah Agha

Journal of Engineering Research

* Lighting is considered of main items in daily life begining from natural Lighting to industrial lighting. with all of it's different shapes . it is considerdone of the most important data that point Blank spaces and works to show architectural spaces, aesthetic values through being sharp and weak, ensure borders show texture or hide Features, suggest wideness, narrowness of space as the most beautiful design don't see beautiful without good lighting which designed carefully.Due to diversity of human activities, architictums spaces and it is wideness. Increased dependence on industrial Lighting to strengthen Job of performance, beauty of internal, external …

Exploring Human Aging Proteins Based On Deep Autoencoders And K-Means Clustering, Sondos M. Hammad, Mohamed Talaat Saidahmed, Elsayed A. Sallam, Reda Elbasiony

Journal of Engineering Research

Aging significantly affects human health and the overall economy, yet understanding of the underlying molecular mechanisms remains limited. Among all human genes, almost three hundred and five have been linked to human aging. While certain subsets of these genes or specific aging-related genes have been extensively studied. There has been a lack of comprehensive examination encompassing the entire set of aging-related genes. Here, the main objective is to overcome understanding based on an innovative approach that combines the capabilities of deep learning. Particularly using One-Dimensional Deep AutoEncoder (1D-DAE). Followed by the K-means clustering technique as a means of unsupervised learning. …

Casar Public Lecture: "Women & Stem Education In Egypt & The Us: Stepping Into A Man's World Of Science & Technology", The Prince Alwaleed Center For American Studies And Research Casar, Yasmeen El Ghazaly, Mark W. Deets

Performances, Events, and Presentations

In celebration of International Women's Day this Month, we held a public lecture titled: "Women & STEM Education in Egypt & the US : Stepping into a Man's World of Science & Technology " on Thursday March 28th, 2024 from 12:15 pm to 1:15 pm (assembly hour) – Conference and Visitor Center, Mary Cross Hall AUC New Cairo Despite a plethora of advances made by women in the world we live in today, they are still woefully underrepresented in the realm of STEM education and the associated career paths. At this event, we uncovered the history, reasons & challenges women …

Resource Optimization For Air Mobility Under Emergency Situations, Yongxin (Jack) Liu

Math Department Colloquium Series

This project aims to improve air traffic management in emergencies. We first developed a GRU neural network to forecast weather-related airport capacity constraints using historical data, underscoring the value of real-time data analysis. We then optimized emergency evacuation air travel using Particle Swarm Optimization, demonstrating the ability to quickly aggregate evacuation flight resources cost-effectively. Finally, we provided a hybrid model combining a genetic algorithm with a neural network for evacuation planning, we show that neural network can be integrated accelerate genetic algorithms for efficient and performance assured system optimization.

Utilization Of Caputo Fractional Derivative In Mhd Nanofluid Flow With Soret And Thermal Radiation Effects, Harshad Patel, Gopal Nanda

Applications and Applied Mathematics: An International Journal (AAM)

In existence of heat diffusion and thermal radiation, an analytical equation is found for unsteady MHD flow past an exponentially accelerating vertical plate in optically thick water based nanofluid. The governing equations are made dimensionless by similarity transformation. A definition of Caputo fractional derivative is applied to generalize governing system of partial differential equations. Laplace transform techniques are applied and obtained the analytical solutions of proposed problems. For a physical point of view, numerical results are obtained using MATLAB software and presented via graphs. From the results, it is concluded that magnetic fields tend to reduce velocity. It is also …

Absorbance Enhancement Of A Treated Tanzanian Kaolin For Removal Of Synthetic Dyes From Water, Samwel Paul Mziray

Tanzania Journal of Engineering and Technology (TJET)

The absorbance efficiency of local kaolin clay from Tanzania (Pugu kaolin) has been enhanced to improve its utilization in removal of textile dyes from water. The clay was acid-activated using H2SO4, after calcination at 750oC. Characterization by XRF, XRD, ATR-FTIR and Porosimeter showed kaolinite [Al2Si2O5(OH)4], silica (SiO2) and microcline [KAlSi3O8] as the main phases. Upon acid treatment, silica increased from 44.18% to 58.81% due to the appearance of tridymite, and alumina decreased from 26.70% to 12.74% due to disappearance of the kaolinite. Surface area increased from 15.36 to 149.61 m2/g due to removal of acid-soluble impurities. The chemical composition showed …

A Two-Stage Based Life Cycle And Principal Component Analysis For Decision Support Of Potential Municipal Solid Wastes Management Scenarios, Case Study Dar Es Salaam, Tanzania, Edwin Richard Ndibalema Dr

Tanzania Journal of Engineering and Technology (TJET)

In most of the urban areas of Tanzania, poor and inadequate solid waste management is a growing environmental and public health concern. Despite an array of solid waste management options, choosing an appropriate one remains a challenge. This study applied a novel two-stage-based approach to assess the environmental impacts and sustainability performance of the 27 scenarios for municipal solid wastes (MSW) management of Dar es Salaam City, Tanzania. In the first stage, the study utilized a life cycle analysis (LCA) to quantify the environmental impacts of MSW scenarios. In the second stage, the study used the principal component analysis (PCA) …

Transfer Learning In The Era Of Foundational Models: Application To Diagnosis In Rheumatology, Prashant Shekhar

Math Department Colloquium Series

Problems with current synovitis grading procedures

• There has been a lack of reliability in grading these images in the medical community due to a lack of universally accepted diagnostic criteria [Momtazmanesh et al., 2022]
• The human/machine variability creates an additional challenge in an efficient automated scoring system [Ranganath et al., 2022]
• There is a lack of consistency between doctors in grading these images [Momtazmanesh et al., 2022]

Characterizing Linearizable Qaps By The Level-1 Reformulation-Linearization Technique, Lucas Waddell, Warren Adams

Faculty Journal Articles

The quadratic assignment problem (QAP) is an extremely challenging NP-hard combinatorial optimization program. Due to its difficulty, a research emphasis has been to identify special cases that are polynomially solvable. Included within this emphasis are instances which are linearizable; that is, which can be rewritten as a linear assignment problem having the property that the objective function value is preserved at all feasible solutions. Various known sufficient conditions for identifying linearizable instances have been explained in terms of the continuous relaxation of a weakened version of the level-1 reformulation-linearization-technique (RLT) form that does not enforce nonnegativity on a subset …

The Influence Of Green Building Design On Tourists' Intention To Stay In Eco-Friendly Hotels: A Study On Perceptions And Preferences, Enas Al Sayed Salama Dr., Gehad Nasr Abdelsalam Dr.

Journal of Engineering Research

Green building design involves integrating sustainable and environmentally friendly practices into the construction and operation of buildings, including hotels, with the goal of minimizing the adverse impact on the environment. This paper delves into the pivotal role of green building design and eco-service provision within the context of green hotels. The aim is to investigate the interconnections among tourists' environmental concerns, their perceived significance of green building design, and their intention to choose green hotels.

To enhance the understanding of tourist behavior and its implications for tourism in Egypt, a questionnaire was administered in Sharm El Sheikh, a prominent Egyptian …

Experimental Study Of Bent Glass Curtain Walls., Sarah Said Abd El Kariem, Moustafa El Shami, Mahmoud El Nagar

Journal of Engineering Research

A Bent Laminated Glass is commonly used in the residential and commercial structures, its methodology is not present in the curves and tables at the ASTM E1300. Therefore, it has become a need for architects to use basis for this type of glass. To the best of authors ‘knowledge, no one study the bent laminated glass in details. A variety of safety glass that has lately gained popularity in the construction sector is modern laminated glass. Given that it offers a safe failover capability, it is perfect for the automotive industry. Double-lite glass is produced using two or more …

Market Analysis And Bidding Strategy Of Hybrid Renewable Energy Systems Considering Emissions, Fatma Elzahraa, Mohamed Elnemr, Samir Dawoud

Journal of Engineering Research

The competition in the electricity markets makes it difficult to choose a suitable strategy for maximizing profit while reducing harmful emissions. To have an adequate energy price for consumers while minimizing the harmful emissions to the atmosphere and maximizing profits of all participants in the electricity market needs an aggressive bidding strategy. Developing these bidding strategies with the integration of renewable energy (RE) in the electricity market became important. This research studies various bidding strategies for maximizing profits in the deregulated energy market since participants are keen on developing bidding strategies considering emissions. These bidding strategies will consider the integration …