Predicting The Influence Of Aggregate Size And Distribution On Cementitious Concrete Properties: A Review,
2025
Department of Mechanical and Industrial Engineering, University of Dar es Salaam, P.O Box 35131, Dar es Salaam, Tanzania
Predicting The Influence Of Aggregate Size And Distribution On Cementitious Concrete Properties: A Review, Innocent J. Macha
Tanzania Journal of Engineering and Technology (TJET)
Cement concrete has been in use for centuries as one of the primary construction materials. Its demand in the construction industry is expected to continue for several centuries before the full development of alternative products. However, one of the main areas of research interest is understanding how its constituents can be tailored to make its properties predictable to reduce risks associated with structural failures, reconstruction and reduced durability. These hindrances associated with cementitious concrete result from several attributes, including constituent material characteristics, mixing ratios and workmanship. Understanding the predictability of cement concrete properties requires computer modelling tools to provide reliable …
Optimizing The Processing Temperature For Synthesis Of Silver Nanoparticles Within Cellulose-Wool Keratin Supramolecular Matrix Using Butylmethylimmidazolium Chloride Ionic Liquid,
2025
Department of Mechanical and Industrial Engineering, College of Engineering and Technology, University of Dar es Salaam, P.O Box 35131, Dar es Salaam, Tanzania
Optimizing The Processing Temperature For Synthesis Of Silver Nanoparticles Within Cellulose-Wool Keratin Supramolecular Matrix Using Butylmethylimmidazolium Chloride Ionic Liquid, Ngesa E. Mushi
Tanzania Journal of Engineering and Technology (TJET)
To date, the synthesis of silver nanoparticles on the surface of cellulose and wool keratin biopolymer, while dissolved in ionic liquid, is attractive because of its biomedical potential. However, the optimal processing temperature for the nanoparticle formation is unclear. The previously reported temperature of approximately 120°C gives unpredictable results. The current study employs a combination of 50% cellulose and 50% keratin, along with 69 mg of silver chloride, in Butylmethylimidazolium Chloride BMImCl ionic liquid, using a single-pot process to produce a supramolecular film via non-derivatized mechanochemical interactions. The primary objective is to experimentally establish the processing temperature to achieve stable …
Vacuum Consistent Electrochemistry In Ionic Liquid Combined With Oxide Epitaxy,
2025
School of Engineering, Tohoku University, 6-6-7, Aramaki Aza Aoba, Aoba-ku, Sendai, 980-8579, Japan
Vacuum Consistent Electrochemistry In Ionic Liquid Combined With Oxide Epitaxy, Yuji Matsumoto
Journal of Electrochemistry
We introduce our state-of-the art of “vacuum consistent electrochemistry” to an investigation of the interfaces between oxides and ionic liquid (IL). Pulsed laser deposition (PLD) has been one of the powerful and sophisticated techniques to realize nanoscale preparation of high-quality epitaxial oxide thin films. On the other hand, electrochemistry is a simple, very sensitive, and non-destructive analysis technique for solid-liquid interfaces. To ensure the reproducibility in experiment of the interfaces of such epitaxial oxide films, as well as bulk oxide single-crystals, with IL, we employ a home-built PLD-electrochemical (EC) system with IL as an electrolyte. The system allows one to …
Pm Irras Studies Of Organized Molecular Films At A Gold Electrode Surface,
2025
Department of Chemistry, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
Pm Irras Studies Of Organized Molecular Films At A Gold Electrode Surface, Zhang-Fei Su, Ai-Cheng Chen, Jacek Lipkowski
Journal of Electrochemistry
This feature article illustrates the potential of polarization modulation infrared reflection absorption spectroscopy (PM IRRAS) to provide molecular-level information about the structure, orientation and conformation of constituents of thin films at electrode surfaces. PM IRRAS relies on the surface selection rules stating that the p-polarized IR beam is enhanced, while the s-polarized beam is attenuated at the metal surface. The difference between p- and s-polarized beams eliminates the background of the solvent and provides IR spectra at a single electrode potential. In contrast, two other popular in situ IR spectroscopic techniques, namely, subtractively normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS) …
Ambient Co2 Capture And Valorization Enabled By Tandem Electrolysis Using Solid-State Electrolyte Reactor,
2025
Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai 200438, China
Ambient Co2 Capture And Valorization Enabled By Tandem Electrolysis Using Solid-State Electrolyte Reactor, Yan-Bo Hua, Bao-Xin Ni, Kun Jiang
Journal of Electrochemistry
Electrocatalytic carbon dioxide reduction is a promising technology for addressing global energy and environmental crises. However, its practical application faces two critical challenges: the complex and energy-intensive process of separating mixed reduction products and the economic viability of the carbon sources (reactants) used. To tackle these challenges simultaneously, solid-state electrolyte (SSE) reactors are emerging as a promising solution. In this review, we focus on the feasibility of applying SSE for tandem electrochemical CO2 capture and conversion. The configurations and fundamental principles of SSE reactors are first discussed, followed by an introduction to its applications in these two specific areas, …
Cyclic Combustion Pressure Dynamics Of A Diesel Engine Operating On Waste Frying Oil Biodiesel Blends Using Wavelets,
2025
Mechanical Power Engineering Departments, Faculty of Engineering, Tanta University, Tanta, Egypt.
Cyclic Combustion Pressure Dynamics Of A Diesel Engine Operating On Waste Frying Oil Biodiesel Blends Using Wavelets, Shady Elmozy, Ahmed Khaira Dr., Elshenawy Elshenawy Prof. Dr., Ali Mohamed Dr., Medhat Elkelawy Prof. Dr,
Journal of Engineering Research
This paper investigates the cyclic combustion pressure dynamics of a single-cylinder diesel engine burning waste frying oil biodiesel blends, employing statistical analysis and continuous wavelet transform (CWT) to evaluate combustion stability. Experiments were conducted at a constant engine load (90%) and speed (1500 rpm), with in-cylinder pressure data collected over 400 consecutive cycles for conventional diesel (RD) and biodiesel blends (UB10, UB30, UB50). Results demonstrate that biodiesel blends marginally reduce average peak cylinder pressure (PP) by 0.3–3.8% while lowering PP variability, evidenced by declining coefficients of variation (COV-PP: 1.27–1.48%), attributed to biodiesel’s elevated viscosity promoting consistent fuel-air mixing. Conversely, mean …
Combustion Characteristics And Cycle-To-Cycle Variations In A Diesel Generator Fueled With Used Frying Oil Biodiesel Blends,
2025
Faculty of Engineering, Tanta University, Tanta, Egypt.
Combustion Characteristics And Cycle-To-Cycle Variations In A Diesel Generator Fueled With Used Frying Oil Biodiesel Blends, Shady Elmozy, Ahmad Khira Dr., E. A. El Shenawy Prof. Dr., Medhat Elkelawy Prof. Dr, Eng.
Journal of Engineering Research
This paper investigates the combustion characteristics and cycle-to-cycle variations in a stationary direct-injection diesel generator fueled with biodiesel derived from used frying oil (UFO) blended with conventional diesel. Used frying oil methyl ester (UFOME), referred to as UB100, was produced through a single-step alkali transesterification process and blended with diesel fuel in varying proportions (UB10, UB20, UB30, UB40, and UB50). Experiments were conducted on a single-cylinder, naturally aspirated diesel engine operating at a constant speed of 1500 rpm under five different load conditions: 0%, 25%, 50%, 75%, and 90%. In-cylinder pressure data from 400 consecutive cycles were analyzed to determine …
Chemical Recycling Of Pet Plastic Waste,
2025
California Polytechnic State University, San Luis Obispo
Chemical Recycling Of Pet Plastic Waste, Charlie Parker, Benjamin Puga, Jake Verschoor
Materials Engineering
The growing accumulation of plastic waste, specifically polyethylene terephthalate (PET), has driven the need for more efficient and scalable chemical recycling methods. This study investigated the methanolysis of PET using zinc oxide (ZnO) nanoparticles as a catalyst and tetrabutylammonium chloride (NBu₄Cl) as an ionic liquid, aiming to reduce methanol consumption while achieving high PET conversion efficiency. ZnO nanoparticles were synthesized via wet chemistry and characterized using Dynamic Light Scattering (DLS), which showed an average particle size of 13.5 nm with a polydispersity index of 0.1556, indicating a moderately-high monodisperse distribution of particles sufficient for reactions. The main conversion product, dimethyl …
Effect Of Household Oil Contamination And Agricultural Soil Contamination On Phyllosilicate Nanocatalyst Performance During Pyrolysis Of Polyolefins,
2025
California Polytechnic State University, San Luis Obispo
Effect Of Household Oil Contamination And Agricultural Soil Contamination On Phyllosilicate Nanocatalyst Performance During Pyrolysis Of Polyolefins, Joey Velasquez
Master's Theses
The effect of household oil and agricultural soil contamination on catalyst performance during polyolefin pyrolysis was simulated on mixed virgin plastic pellets by evaluating contamination influence on mixed plastic degradation temperatures. Three phyllosilicate nanocatalysts including Fulcat435, Fulcat22F and Y-Zeolite were evaluated in this work based on a literature review of catalyzed plastic pyrolysis and these catalysts’ ability to lower plastic decomposition temperature by 50 °C – 100 °C. These findings were confirmed in this research through thermogravimetric analysis of a polyolefin mixture and further developed in furnace experiments containing household oil and agricultural contamination. Household oil contamination deactivated each of …
Interaction Of Liquid Phase Diisopropyl Methyl Phosphonate (Dimp) With Material Surrogates For Components Of Soil And Combustion Products Of Metal Fuels,
2025
New Jersey Institute of Technology
Interaction Of Liquid Phase Diisopropyl Methyl Phosphonate (Dimp) With Material Surrogates For Components Of Soil And Combustion Products Of Metal Fuels, Khushi Sunil Patel
Theses
Combustion products of three different Al-based materials, Al-CaCO3, Al-SiO2, and Al-Fe2O3 , have been produced to understand their interaction with liquid diisopropyl methyl phosphonate (DIMP), a surrogate for chemical weapon agents. The purpose of this is to see which materials were more effective at DIMP adsorption and decomposition at different temperatures. Prepared materials were characterized using electron microscopy, x-ray powder diffraction, and nitrogen adsorption. Prepared powders were submerged in DIMP and heated in a thermal analyzer, tracking the mass changes as a function of temperature. Surfaces of the recovered materials were studied using …
Preparation And Modification Of Mxene Composites For Application In Electrochemical Energy Storage,
2025
a School of Science, Xi’an Polytechnic University, No. 19 of Jinhua South Road, Beilin District, Xi’an 710048, PR China
Preparation And Modification Of Mxene Composites For Application In Electrochemical Energy Storage, Zhang-Hai You, Ding-Ze Lu, Kiran Kumar Kondamareddy, Wen-Ju Gu, Peng-Fei Cheng, Jing-Xuan Yang, Rui Zheng, Hong-Mei Wang
Journal of Electrochemistry
With the acceleration of advanced industrialization and urbanization, the environment is deteriorating rapidly, and non-renewable energy resources are depleted. The gradual advent of potential clean energy storage technologies is particularly urgent. Electrochemical energy storage technologies have been widely used in multiple fields, especially supercapacitors and rechargeable batteries, as vital elements of storing renewable energy. In recent years, two-dimensional material MXene has shown great potential in energy and multiple application fields thanks to its excellent electrical properties, large specific surface area, and tunability. Based on the layered materials of MXene, researchers have successfully achieved the dual functions of energy storage and …
Theoretical Insights Into The Atomic And Electronic Structures Of Polyperyleneimide: On The Origin Of Photocatalytic Oxygen Evolution Activity,
2025
International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an, China
Theoretical Insights Into The Atomic And Electronic Structures Of Polyperyleneimide: On The Origin Of Photocatalytic Oxygen Evolution Activity, Yi-Qing Wang, Zhi Lin, Ming-Tao Li, Shao-Hua Shen
Journal of Electrochemistry
Polymeric perylene diimide (PDI) has been evidenced as a good candidate for photocatalytic water oxidation, yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration. Herein, with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern, the electronic structure is theoretically illustrated by the first-principles density functional theory calculations, suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI. It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal …
Three-Dimensional Melamine Carbon Sponge/Nai As Cathode Materials For Sodium-Ion Batteries,
2025
a School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, Guangdong, PR China
Three-Dimensional Melamine Carbon Sponge/Nai As Cathode Materials For Sodium-Ion Batteries, Qian-Ying Huang, Yue Liu, Zi-Xin Lin, Shu-Yi Zheng, Ting-Ting Mei, Yu-Ting Tang, Ying-He Zhang, Jun Liu
Journal of Electrochemistry
The sodium-iodine (Na-I) battery exhibits significant potential as an alternative energy storage device to the lithium-ion battery. However, its development is hindered by inadequate electrical and thermal stability, as well as the dissolution and shuttling of polyiodide. In this study, we report a preparation method for melamine carbon sponge (MC) via carbonizing a commercially available kitchen sponge. It was revealed that the as-prepared MC, composed of unique self-growing carbon nanotubes, could provide both physical and chemical adsorption capabilities for intermediate polyiodides to improve the electrochemical performance of NaI. Consequently, the NaI/MC electrode effectively minimized polyiodide dissolution and reduced the electrochemical …
Understanding The Morphology And Mass Transport Resistance Of Mesoporous Carbon-Supported Pemfc Based On Modeling Analysis,
2025
Shanghai Hydrogen Propulsion Technology Co., Ltd., Shanghai, China
Understanding The Morphology And Mass Transport Resistance Of Mesoporous Carbon-Supported Pemfc Based On Modeling Analysis, Hao Deng, Jia Liu, Zhong-Jun Hou
Journal of Electrochemistry
Mesoporous carbon supports mitigate Pt sulfonic poisoning through nanopore-confined Pt deposition, yet their morphological impacts on oxygen transport remain unclear. This study integrates carbon support morphology simulation with an enhanced agglomerate model to establish a mathematical framework elucidating pore evolution, Pt utilization, and oxygen transport in catalyst layers. Results demonstrate dominant local mass transport resistance governed by three factors: (1) active site density dictating oxygen flux; (2) ionomer film thickness defining shortest transport path; (3) ionomer-to-Pt surface area ratio modulating practical pathway length. At low ionomer-to-carbon (I/C) ratios, limited active sites elevate resistance (Factor 1 dominant). Higher I/C ratios improve …
Zn–Assisted Synthesis Of M (Mn/Fe/Co/Ni)-N-C Catalysts For Multifunctional Electrochemical Activity,
2025
Pittsburg State University
Zn–Assisted Synthesis Of M (Mn/Fe/Co/Ni)-N-C Catalysts For Multifunctional Electrochemical Activity, Kemila A. Chaudhary
Electronic Theses & Dissertations
The design and development of atomically dispersed M-N-C catalysts (metal (M) supported on an nitrogen-carbon (NC) matrix with high multifunctional electrocatalytic performance is desirable but proved to be very challenging. Herein, we synthesized M-N-C catalysts (M = Fe, Co, Mn, and Ni) using Zn-assisted high temperature treatment and characterized using various techniques. The prepared catalysts were tested for their electrocatalytic performance towards oxygen and hydrogen evolution reaction (OER and HER) as well as oxygen reduction reaction (ORR) in alkaline media. The results indicated that Mn-N-C catalyst showed higher performance towards both the ORR (E1/2 = 0.90 V) and …
Ultrafast Laser Surface Structuring For Wettability Control On Copper,
2025
Clemson University
Ultrafast Laser Surface Structuring For Wettability Control On Copper, Akshay Arvind Nagvenkar
All Theses
Wettability is a crucial surface property influencing various phenomena, including heat transfer, cell adhesion, and corrosion. Engineering devices can achieve superior performance by precisely manipulating surface wettability. As a result, extensive research has focused on developing surfaces that exhibit either extreme water attraction (superhydrophilic) or strong water repellency (superhydrophobic). Tailoring surface wettability paves the way for numerous applications, such as drag reduction in marine vessels, controlled drug delivery, efficient water collection, advanced liquid transport systems, oil-water separation, anti-corrosion coatings, friction reduction, and self-cleaning materials. Ultrafast laser surface structuring is a promising approach for engineering multifunctional surfaces, effectively modifying material properties …
The Effect Of Catalyst Choice On Biodiesel Yield And Quality Using Waste Cooking Oil As A Feedstock,
2025
University of Tennessee at Chattanooga
The Effect Of Catalyst Choice On Biodiesel Yield And Quality Using Waste Cooking Oil As A Feedstock, Neka Long
Honors Theses
Biodiesel is one current area of interest as a replacement for traditional diesel fuel. Benefits of biodiesel include that it can be derived from renewable resources, and it possesses properties similar to that of traditional diesel fuel. Biodiesel is often produced through a catalyzed transesterification process, which involves the use of a catalyst to aid in the conversion of triglycerides into alkyl esters. A method called the transesterification double step process (TDSP) was researched and used in this project due to the success seen using this method for the conversion of waste cooking oil to biodiesel. In this project, four …
Assessment Of Factors Contributing On Early Rotting Of Chromated Copper Arsenate Treated Utility Power Distribution Wood Poles In Tanzania,
2025
Department of Mechanical and Industrial Engineering, University of Dar es Salaam, P.O Box 35131, Dar es Salaam, Tanzania
Assessment Of Factors Contributing On Early Rotting Of Chromated Copper Arsenate Treated Utility Power Distribution Wood Poles In Tanzania, Innocent J. Macha
Tanzania Journal of Engineering and Technology (TJET)
The study aimed to assess the factors contributing to the premature decay of Chromated Copper Arsenate (CCA) treated utility power distribution wooden poles in Tanzania. Deteriorated poles samples from various regions in Tanzania were analyzed using handheld X-ray spectrometry to quantify the retention of CCA preservative chemicals. The ages of these poles were estimated based on annual growth rings. The findings indicated that premature failure of CCA treated wooden poles is attributed to an imbalance in the chemical composition of the preservative solution. The study found that CuO retention in most samples ranged between 10-18 kg/m3, significant lower that the …
Effect Of The Cao Catalyst Concentration Based On Barnacle Shells (Tetraclita Squamosa) On Biodiesel Production From Coconut Oil,
2025
Department of Chemical Engineering, Faculty of Engineering, Tanjungpura University, Pontianak 78124, Indonesia
Effect Of The Cao Catalyst Concentration Based On Barnacle Shells (Tetraclita Squamosa) On Biodiesel Production From Coconut Oil, Rinjani Rakasiwi, Sri Rezeki, Nurul Hafiza, Wivina Diah Ivontianti
Makara Journal of Technology
Barnacle shells are a source of the calcium oxide (CaO) catalyst, which is nontoxic, highly alkaline, and biodegradable. This study aims to determine the characteristics and the effect of the CaO catalyst concentration obtained from the calcination of barnacle shell particles at a temperature of 900 ℃ for 2 and 4 h on the transesterification reaction of biodiesel from coconut oil. Transesterification was conducted at 65℃ for 2 h with a methanol/coconut oil molar ratio of 6:1. The concentration of the CaO catalyst was varied (i.e., 1wt%, 3wt%, 5wt%, 7wt%, and 9wt%) for coconut oil. The results of the characterization …
Production Of Potassium-Rich Biofertilizer From Composted Banana Peels And Watermelon Rinds,
2025
Department of Chemical and Process Engineering, College of Engineering and Technology, University of Dar es Salaam, P.O. Box 35091, Dar es Salaam, Tanzania
Production Of Potassium-Rich Biofertilizer From Composted Banana Peels And Watermelon Rinds, Neema O. Msuya
Tanzania Journal of Engineering and Technology (TJET)
This study investigated the production of biofertilizer from composted banana peels and watermelon rinds, focusing on the mineral content and its impact on plant growth. The process involved characterizing raw materials, producing biofertilizer, analyzing mineral concentrations (potassium, nitrogen and phosphorus), and evaluating its quality through Spiny Amaranth seed growth. A compost bin with three compartments was designed, testing three composting ratios of banana peels to watermelon rinds (2:1, 1:2 and 1:1). Composting was monitored on moisture content, pH, organic matter, and temperature for 37 days. The 1:1 ratio had the lowest temperature (33.45°C) and highest pH (7.08), while the 2:1 …
