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Articles 211 - 240 of 993
Full-Text Articles in Applied Mathematics
Chemical Kinetic Investigation: Exploring The Impact Of Various Concentrations Of Hho Gas With A 40% Biodiesel/Diesel Blend On Hcci Combustion, Mai H. Aboubakr, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi, Ayman Refat Abd Elbar
Chemical Kinetic Investigation: Exploring The Impact Of Various Concentrations Of Hho Gas With A 40% Biodiesel/Diesel Blend On Hcci Combustion, Mai H. Aboubakr, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi, Ayman Refat Abd Elbar
Journal of Engineering Research
This study uses the Chemkin software program to evaluate the effect of different quantities of oxyhydrogen gas [HHO] added to 40% biodiesel and diesel mix [B40], including B40, B40+5HHO, B40+10HHO, and B40+15HHO, on the HCCI combustion process's efficiency. The information collected includes cylinder pressure, cylinder temperature, accumulated gas phase heat release, heat loss rate, UHC, and mole fractions of O2, CO, CO2, diesel [NC7H16], biodiesel [C5H10O2], and oxyhydrogen [H2O]. The finding is that, when compared to a blend of biodiesel and diesel, using oxyhydrogen in the biodiesel/diesel mix boosts the properties of the HCCI engine.
Exploring The Influence Of Various Factors, Including Initial Temperatures, Equivalence Ratios, And Different Biodiesel/Diesel Blend Ratios, On Homogeneous Charge Compression Ignition (Hcci) Combustion, Mai H. Aboubakr, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi, Ayman Refat Abd Elbar
Exploring The Influence Of Various Factors, Including Initial Temperatures, Equivalence Ratios, And Different Biodiesel/Diesel Blend Ratios, On Homogeneous Charge Compression Ignition (Hcci) Combustion, Mai H. Aboubakr, Medhat Elkelawy Prof. Dr, Eng., Hagar Alm-Eldin Bastawissi, Ayman Refat Abd Elbar
Journal of Engineering Research
This paper discusses the impact of three study cases that change with different values: the first case is four initial temperature values [313, 323, 333, and 343 K], the second case is three equivalence ratios [0.2, 0.3, and 0.4], and the third case uses various concentrations of biodiesel and diesel mixes [D100, B20, B40, B60, B80, and B100]. The purpose is to use the Chemkin software program to determine the effectiveness of each case in the HCCI combustion process. The results included cylinder pressure, cylinder temperature, accumulated gas phase heat release, heat loss rate, UHC, and mole fractions of O …
Survey And Analysis Of Safety Components And Costs In Construction Projects In Egypt, Emad E. Etman Prof., Haytham Sanad Prof., Asmaa Ibrahim Khater
Survey And Analysis Of Safety Components And Costs In Construction Projects In Egypt, Emad E. Etman Prof., Haytham Sanad Prof., Asmaa Ibrahim Khater
Journal of Engineering Research
The difficulty of determining the factors that achieve safety on Egyptian construction sites as a result of multiple and different criteria and different relative weights of the criteria represents a challenge to achieve safety and a secure environment on construction sites. This issue has been of interest for many decades and continues to be a topic of discussion today because of construction project management is rapidly modernizing. The paper aims to identify the safety standards most commonly used on construction sites, and determine their relative weights as seen by the target audience and also estimate the cost of safety measures …
Enhancing Decision In Information System Through Weighted Preliminary Pretopology Analysis, Mustafa Elsayed, Rifet Agassi
Enhancing Decision In Information System Through Weighted Preliminary Pretopology Analysis, Mustafa Elsayed, Rifet Agassi
Journal of Engineering Research
It is clear from adequate study of the past decades that there has been rapid growth in the information system, which relies mainly on programming systems. This has led to the necessity of dealing with high efficiency with the information system necessary for decision support. Information systems are a mixture of software and hardware to store and process all the data required and are presented in a useful form to extract information by applying topological concepts. In this paper a pretopological space from an information system is to be constructed. The computation of decision accuracy stands as a pivotal stage …
تحسين كفاءه التوازن الحرارى لمستخدمى الفراغات السكنيه, Alamera Kamal Elden Elfeky, Elamira Elfeky, Walaa Ahmed Nour, Lobna Abdallah Agha
تحسين كفاءه التوازن الحرارى لمستخدمى الفراغات السكنيه, Alamera Kamal Elden Elfeky, Elamira Elfeky, Walaa Ahmed Nour, Lobna Abdallah Agha
Journal of Engineering Research
human belonging to nature Considered innate, and known as Biophilie, it has direct and strong relation with human heath and his welfare which affected by quality of internal environment where we Live and work as we spend most of our time in this environment. Biophelic design Aim to improve heath and welfare of human. natural. and reconnect him with his natural environment beside achieving the aesthetic aspect of his place.
in our present time, gap appeared in relation between human and environment as a result of modern design solution, as it has negative effect on human heath and safety, to …
Towards Environmentally Sustainable Preservation Of Heritage Buildings, Rozal Rozal Yousef Hanna1, Ayman Gamal El-Din Abd El- Tawab2, Walaa Abou El- Haggag Mehanna3
Towards Environmentally Sustainable Preservation Of Heritage Buildings, Rozal Rozal Yousef Hanna1, Ayman Gamal El-Din Abd El- Tawab2, Walaa Abou El- Haggag Mehanna3
Journal of Engineering Research
The construction industry, characterized by its intricate processes and extensive stakeholder networks, stands at the cusp of a digital revolution. The adoption of blockchain-smart contract (BCSC) technology is at the heart of this transformation. This research delves deep into the BCSC within the construction arena to provide comprehensive insight into its probable applications, inherent challenges, and potential future trajectories. Leveraging the PRISMA analysis technique, a curated collection of relevant academic research articles was assembled, shedding light on the existing body of knowledge regarding the application of BCSC technology in construction. The authors developed an innovative user interface tool customized to …
Review: Protection Of Wooden Structures With Nano-Titanium Dioxide Coating, Zienab Zienab A. Ahmed1*, And M. M. Mosallem2
Review: Protection Of Wooden Structures With Nano-Titanium Dioxide Coating, Zienab Zienab A. Ahmed1*, And M. M. Mosallem2
Journal of Engineering Research
Wood is widely used for various purposes with good performance. Wood works as the main material for furniture, monuments, decorations and constructions. which has the close relationship with human. Durability of wood is important in ensuring an appropriate life for the structure being designed. Wooden construction deteriorates easily due to UV radiation and weather conditions. Many of wood types need a preservative treatment. Several compounds are available for chemical protection, but not all are completely safe for human health. New technologies with low environmental impact and economically feasible are developed, which improves the life cycle of wood. Titanium dioxide is …
Urbanism Strategies For Linking Existing And New Cities, Naglaa J. Q. Mo’Men Abdel-Qader Ebrahim1, Mohsen Bayad2
Urbanism Strategies For Linking Existing And New Cities, Naglaa J. Q. Mo’Men Abdel-Qader Ebrahim1, Mohsen Bayad2
Journal of Engineering Research
New cities, designed for urban growth outside existing metropolitan regions, face challenges in street infrastructure due to rapid expansion. Efficient control of mobility is crucial as cities grow. Sustainable transportation involves factors like infrastructure, public transit, delivery networks, affordability, efficiency, air quality, health, and reduced emissions. Commuting between established and new urban areas is common, leading to issues like urban sprawl, longer travel times, and congestion in developing countries. The challenge is to improve accessibility while addressing air quality, traffic, congestion, noise, built environment, emissions, and sprawl. This study aims to explore factors influencing mobility choices in Egypt, focusing on …
The Impacts Of Dimensionality, Diffusion, And Directedness On Intrinsic Cross-Model Simulation In Tile-Based Self-Assembly, Daniel Hader, Matthew J. Patitz
The Impacts Of Dimensionality, Diffusion, And Directedness On Intrinsic Cross-Model Simulation In Tile-Based Self-Assembly, Daniel Hader, Matthew J. Patitz
Computer Science and Computer Engineering Faculty Publications and Presentations
Motivated by applications in DNA-nanotechnology, theoretical investigations in algorithmic tile-assembly have blossomed into a mature theory. In addition to computational universality, the abstract Tile Assembly Model (aTAM) was shown to be intrinsically universal (FOCS 2012), a strong notion of completeness where a single tile set is capable of simulating the full dynamics of all systems within the model; however, this construction fundamentally required non-deterministic tile attachments. This was confirmed necessary when it was shown that the class of directed aTAM systems, those where all possible sequences of tile attachments result in the same terminal assembly, is not intrinsically universal (FOCS …
Hardware Acceleration Of Numerical Methods For Solving Ordinary Differential Equations, Soham Bhattacharya
Hardware Acceleration Of Numerical Methods For Solving Ordinary Differential Equations, Soham Bhattacharya
Theses and Dissertations
Along with the advancement in technology, the role of hardware accelerators is increasing consistently, delivering advancements in scientific simulations and data analysis in scientific computing, signal processing tasks in communication systems, matrix operations, and neural network computations in artificial intelligence and machine learning models. On the other hand, several high-speed computer applications in this era of high-performance computing often depend on ordinary differential equations (ODEs); however, their nonlinear nature can present a challenge to obtaining analytic solutions. Consequently, numerical approaches prove effective in delivering only approximate solutions to these equations. This research discusses the implementation of a customized hardware accelerator …
Unconventional Computing With Photonic Oscillator Networks, Mostafa Honari Latifpour
Unconventional Computing With Photonic Oscillator Networks, Mostafa Honari Latifpour
Dissertations, Theses, and Capstone Projects
The ever-increasing demand for data processing and the challenges in scaling traditional computing architectures are driving intensive research into alternative computing paradigms. Optical computing has garnered renewed attention since the 2010s, driven by its potential to accelerate specialized computational tasks such as combinatorial optimization and neural networks.
Coherent light sources including lasers and parametric oscillators have been around for decades and become indispensable tools in modern technology, but these photonic oscillators are also nonlinear dynamical systems that can exhibit emergent, complex phenomena, especially when coupled in arrays. These nonlinear optical systems have recently been shown to be capable of doing …
Effect Of Recommending Users And Opinions On The Network Connectivity And Idea Generation Process, Sriniwas Pandey, Hiroki Sayama
Effect Of Recommending Users And Opinions On The Network Connectivity And Idea Generation Process, Sriniwas Pandey, Hiroki Sayama
Northeast Journal of Complex Systems (NEJCS)
The growing reliance on online services underscores the crucial role of recommendation systems, especially on social media platforms seeking increased user engagement. This study investigates how recommendation systems influence the impact of personal behavioral traits on social network dynamics. It explores the interplay between homophily, users’ openness to novel ideas, and recommendation-driven exposure to new opinions. Additionally, the research examines the impact of recommendation systems on the diversity of newly generated ideas, shedding light on the challenges and opportunities in designing effective systems that balance the exploration of new ideas with the risk of reinforcing biases or filtering valuable, unconventional …
Duality Of Ensemble Systems Through Moment Representations, Vignesh Narayanan, Wei Zhang, Jr-Shin Li
Duality Of Ensemble Systems Through Moment Representations, Vignesh Narayanan, Wei Zhang, Jr-Shin Li
Publications
Controlling large-scale dynamic population systems, known as ensemble control, is a pervasive and essential task in many emerging applications from diverse scientific domains. Previous focuses in the area of ensemble control have been placed on seeking open-loop control strategies due to unavailability of state feedback information for each individual system in the ensemble. In this paper, we develop a foundational framework for analysis and control of ensemble systems with closed feedback control loops. We introduce the notion of ensemble moments and construct moment systems associated with the ensemble systems. By extending the classical moment problem in mathematical analysis and statistics, …
Non-Contact Wind Turbine Blade Crack Detection Using Laser Doppler Vibrometers, Ali Zabihi, Farhood Aghdasi, Chadi Ellouzi, Nand Kishore Singh, Ratneshwar Jha, Chen Shen
Non-Contact Wind Turbine Blade Crack Detection Using Laser Doppler Vibrometers, Ali Zabihi, Farhood Aghdasi, Chadi Ellouzi, Nand Kishore Singh, Ratneshwar Jha, Chen Shen
Henry M. Rowan College of Engineering Departmental Research
In response to the growing global demand for both energy and a clean environment, there has been an unprecedented rise in the utilization of renewable energy. Wind energy plays a crucial role in striving for carbon neutrality due to its eco-friendly characteristics. Despite its significance, wind energy infrastructure is susceptible to damage from various factors including wind or sea waves, rapidly changing environmental conditions, delamination, crack formation, and structural deterioration over time. This research focuses on investigating non-destructive testing (NDT) of wind turbine blades (WTBs) using approaches based on the vibration of the structures. To this end, WTBs are first …
Bidding Strategy For A Wind Power Producer In Us Energy And Reserve Markets, Anne Stratman
Bidding Strategy For A Wind Power Producer In Us Energy And Reserve Markets, Anne Stratman
Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research
Wind power is one of the world's fastest-growing renewable energy resources and has expanded quickly within the US electric grid. Currently, wind power producers (WPPs) may sell energy products in US markets but are not allowed to sell reserve products, due to the uncertain and intermittent nature of wind power. However, as wind’s share of the power supply grows, it may eventually be necessary for WPPs to contribute to system-wide reserves. This paper proposes a stochastic optimization model to determine the optimal offer strategy for a WPP that participates in the day-ahead and real-time energy and spinning reserve markets. The …
Cost-Risk Analysis Of The Ercot Region Using Modern Portfolio Theory, Megan Sickinger
Cost-Risk Analysis Of The Ercot Region Using Modern Portfolio Theory, Megan Sickinger
Master's Theses
In this work, we study the use of modern portfolio theory in a cost-risk analysis of the Electric Reliability Council of Texas (ERCOT). Based upon the risk-return concepts of modern portfolio theory, we develop an n-asset minimization problem to create a risk-cost frontier of portfolios of technologies within the ERCOT electricity region. The levelized cost of electricity for each technology in the region is a step in evaluating the expected cost of the portfolio, and the historical data of cost factors estimate the variance of cost for each technology. In addition, there are several constraints in our minimization problem to …
Modeling Vibration Stiffness: An Analytical Extension Of Hertzian Theory For Angular Contact Bearings With A Thin Viscoelastic Coating, Davis R. Burton
Modeling Vibration Stiffness: An Analytical Extension Of Hertzian Theory For Angular Contact Bearings With A Thin Viscoelastic Coating, Davis R. Burton
Honors Theses
This thesis considers the novel angular contact rolling-element bearings proposed by NASA’s Glenn Research Center, which are coated with a thin solid lubricant that exhibits viscoelastic behavior. Current analytical models for the dynamic stiffness matrix of angular contact bearings, critical for vibration analysis, lack the ability to model the effects of a solid coating, as well as the time dependencies inherent in viscoelastic theory. The author first presents an overview of the stiffness matrix derivation, followed by a treatment of the underlying Hertzian contact theory. An analytical extension of this theory is proposed which accounts for a thin elastic layer …
Representation Learning For Generative Models With Applications To Healthcare, Astronautics, And Aviation, Van Minh Nguyen
Representation Learning For Generative Models With Applications To Healthcare, Astronautics, And Aviation, Van Minh Nguyen
Theses and Dissertations
This dissertation explores applications of representation learning and generative models to challenges in healthcare, astronautics, and aviation.
The first part investigates the use of Generative Adversarial Networks (GANs) to synthesize realistic electronic health record (EHR) data. An initial attempt at training a GAN on the MIMIC-IV dataset encountered stability and convergence issues, motivating a deeper study of 1-Lipschitz regularization techniques for Auxiliary Classifier GANs (AC-GANs). An extensive ablation study on the CIFAR-10 dataset found that Spectral Normalization is key for AC-GAN stability and performance, while Weight Clipping fails to converge without Spectral Normalization. Analysis of the training dynamics provided further …
System Identification For Motion Control Of Unmanned Aerial Vehicles Platform, Raj Ramesh Agarwal
System Identification For Motion Control Of Unmanned Aerial Vehicles Platform, Raj Ramesh Agarwal
Theses and Dissertations
Comprehensive research on Unmanned Aerial Vehicles (UAV) system identification for motion control parameters is presented in this thesis, with a focus on the necessity of precise control and improved performance. Using Pseudorandom Binary Sequence (PRBS) and Normally Distributed Random Numbers, it presents a unique technique for excitation of UAV dynamic systems. It also shows how effective random signals are in time-domain identification for precise control in a range of flying circumstances. The piece of research includes a thorough analysis and implementation of various approaches and its further improvements, highlighting the benefits and drawbacks of each. These approaches include the free …
Sol-Gel Synthesis And Microstructure Characterization Of Nio-Tio2 Semiconductor, Godlisten N. Shao
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
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 …
Thermogravimetric Analysis And Chemical Kinetics Of Waste Tires, Mahir Mohammed Said
Thermogravimetric Analysis And Chemical Kinetics Of Waste Tires, Mahir Mohammed Said
Tanzania Journal of Engineering and Technology (TJET)
The focus of this paper is to analyse the pyrolysis reaction of waste tires. The pyrolysis was studied experimentally using thermal and chemical kinetics. The tires were pyrolyzed using thermogravimetry at a temperature range of 200 to 600°C, with heating rates of 10, 20, and 50°C/min. The activating energy was observed to increase with increased temperature. The highest activating energy was 101.02 kJ/mol at a heating rate of 50°C/min.
Design And Optimization Of An Azeotropic Distillation Pilot Plant For The Production Of Pure Ethanol, Samwel V. Manyele
Design And Optimization Of An Azeotropic Distillation Pilot Plant For The Production Of Pure Ethanol, Samwel V. Manyele
Tanzania Journal of Engineering and Technology (TJET)
This study aimed to design an azeotropic distillation plant using Aspen Plus® V10 software and determine optimal process conditions for producing pure ethanol greater than 95% from pre-concentrated near-azeotropic ethanol-water solution. The non-random two-liquid Redlich-Kwong thermodynamic model was the base method for property analysis and performance prediction. Modelling and simulation of the converged process were conducted for fixed column variables (R = 5, N = 12 and p = 1 atm). Plant operating parameters were varied in the range of 0 to 1 for the pre-heater vapour fraction, 2 to 10 for the column feed plates (NFP), 2 to 6 …
Enhanced Post Deposition Annealing Conditions On The Fabrication Of High Quality Thermochromic Vanadium Dioxide Films, Nuru R. Mlyuka
Enhanced Post Deposition Annealing Conditions On The Fabrication Of High Quality Thermochromic Vanadium Dioxide Films, Nuru R. Mlyuka
Tanzania Journal of Engineering and Technology (TJET)
Sputter deposition of thermochromic VO2 thin films for smart window applications has been faced with several challenges including the need for high deposition temperature, extremely precise and narrow range of oxygen/argon flow ratio and target poisoning during sputtering. Deposition of VO2 at room temperature without oxygen followed by post-deposition annealing has been cited as one of the potential mitigations to the challenge. In this study, the effects of post-deposition annealing conditions on the structural, electrical and optical properties of VO2 thin films are reported. The films were prepared on soda lime glass substrates using DC magnetron sputtering of metallic vanadium …
Optimization Pump As Turbine Coupled To A Self-Excited Induction Generator Using Multi-Objective Genetic Algorithm, Emanuel J. Nyirenda
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 …
Optimal Load Shedding During Service Restoration In Electrical Secondary Distribution Network Based On Reinforcement Learning, Rukia J. Mwifunyi
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 …
Evaluation Of Cybersecurity In Remote Working Settings For Mobile Network Operators, Victoria Mahabi
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 …
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
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 …
A 2-D Numerical Model For Evaluating Daylight Penetration In Short Tunnels For Enhanced Driver Safety, Joachim James
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. …