Open Access. Powered by Scholars. Published by Universities.®

Catalysis and Reaction Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2024

Discipline
Institution
Keyword
Publication
Publication Type

Articles 31 - 60 of 87

Full-Text Articles in Catalysis and Reaction Engineering

2024 "Electrochemical Research Paradigms" Summer School Successfully Held, Editorial Office Of J.Electrochem. Aug 2024

2024 "Electrochemical Research Paradigms" Summer School Successfully Held, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.


Upcoming Meeting-The 1St Young Investigator Symposium On Electrosynthesis, Chinese Chemical Society, Chinese Society Of Electrochemistry (Cse) Aug 2024

Upcoming Meeting-The 1St Young Investigator Symposium On Electrosynthesis, Chinese Chemical Society, Chinese Society Of Electrochemistry (Cse)

Journal of Electrochemistry

No abstract provided.


Voltammetric Determination Of Hydrogen Peroxide At Decorated Palladium Nanoparticles/Poly 1,5- Diaminonaphthalene Modified Carbon-Paste Electrode, Ziad Khalifa, Mohamed Fathi Abo Oura, Magdi Abdelazzem, Ablah Hathoot Aug 2024

Voltammetric Determination Of Hydrogen Peroxide At Decorated Palladium Nanoparticles/Poly 1,5- Diaminonaphthalene Modified Carbon-Paste Electrode, Ziad Khalifa, Mohamed Fathi Abo Oura, Magdi Abdelazzem, Ablah Hathoot

Chemical Engineering

In this work, palladium nanoparticles (PdNPs)/p1,5-DAN/ carbon paste electrode (CPE) and p1,5-DAN/CPE sensors have been developed for determination of hydrogen peroxide. Both sensors showed a highly sensitive and selective electrochemical behaviour, which were derived from a large specific area of poly 1,5 DAN and super excellent electroconductibility of PdNPs. PdNPs/p1,5-DAN/CPE exhibited excellent performance over p1,5-DAN/CPE. Thus, it was used for detecting hydrogen peroxide (H2O2) with linear ranges of 0.1 to 250 μM and 0.2 to 300 μM as well as detection limits (S/N= 3) of 1.0 and 5.0 nM for square wave voltammetry (SWV) and cyclic voltammetry (C.V) techniques, respectively. …


Unveiling The Indoor Performance Of Perovskite/Silicon Tan‑Dem Solar Cells: A Comprehensive Exploration Through Numerically Modelled Energy Band Diagrams, Ziad Khalifa, Sameh O. Abdellatif, Alexander De-Bernardinis, Muath Alkadi, Mostafa Ganoud, Saif Qaid Aug 2024

Unveiling The Indoor Performance Of Perovskite/Silicon Tan‑Dem Solar Cells: A Comprehensive Exploration Through Numerically Modelled Energy Band Diagrams, Ziad Khalifa, Sameh O. Abdellatif, Alexander De-Bernardinis, Muath Alkadi, Mostafa Ganoud, Saif Qaid

Chemical Engineering

This paper delves into the indoor performance analysis of Perovskite/Silicon Tandem Solar Cells (PSSTC) through a detailed exploration utilizing numerically modeled energy band diagrams. The primary objective is to uncover the potential of PSSTC for solar energy conversion in indoor settings. Various tandem cell configurations are scrutinized under diverse artificial lighting spectra, with an innovative Li4Ti5O12/ CsPbCl3/MAPbBr3/CH3NH3PbI3/ Si architecture achieving an exceptional maximum power conversion efficiency of 25.25%. This represents a substantial efficiency enhancement of nearly 7% compared to standalone Silicon cells. The study underscores the significance of design optimization in maximizing performance. The energy band diagram analysis reveals a …


Investigation Of Heavy Metal Composition And Associated Health Risks From Selected Groundwater Wells In Temeke, Dar-Es-Salaam, Justin M. Jeremiah Aug 2024

Investigation Of Heavy Metal Composition And Associated Health Risks From Selected Groundwater Wells In Temeke, Dar-Es-Salaam, Justin M. Jeremiah

Tanzania Journal of Engineering and Technology (TJET)

Water quality continues to be the challenge to residents in Dar es Salaam due to various anthropogenic activities in the city. This study was conducted to assess groundwater quality by determining concentrations of heavy metals. Both probability and Nonprobability sampling techniques were used to collect samples from 40 groundwater wells in 24 wards of Temeke municipal and analysed using Microwave Plasma Atomic Emission Spectrometer (Agilent 4210 MP-AES) at the Geochemistry Laboratory of the University of Dar es Salaam. Results indicated varying heavy metal concentrations ranging from 0.71 ± 0.08 to 6.64 ± 0.21 mg/l for As, 0.02 ± 0.01 to …


Professor Yong Yang, The Editorial Board Member Of Journal Of Electrochemistry, Is Elected As A Fellow Of The Electrochemical Society, Editorial Office Of J.Electrochem. Jul 2024

Professor Yong Yang, The Editorial Board Member Of Journal Of Electrochemistry, Is Elected As A Fellow Of The Electrochemical Society, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.


First Announcement Of 76th Annual Meeting Of The International Society Of Electrochemistry, International Society Of Electrochemistry (Ise) Jul 2024

First Announcement Of 76th Annual Meeting Of The International Society Of Electrochemistry, International Society Of Electrochemistry (Ise)

Journal of Electrochemistry

No abstract provided.


Series Reports From Professor Wei’S Group Of Chongqing University: Advancements In Electrochemical Energy Conversions (1/4): Report 1: High-Performance Oxygen Reduction Catalysts For Fuel Cells, Fa-Dong Chen, Zhuo-Yang Xie, Meng-Ting Li, Si-Guo Chen, Wei Ding, Li Li, Jing Li, Zi-Dong Wei Jul 2024

Series Reports From Professor Wei’S Group Of Chongqing University: Advancements In Electrochemical Energy Conversions (1/4): Report 1: High-Performance Oxygen Reduction Catalysts For Fuel Cells, Fa-Dong Chen, Zhuo-Yang Xie, Meng-Ting Li, Si-Guo Chen, Wei Ding, Li Li, Jing Li, Zi-Dong Wei

Journal of Electrochemistry

Two major challenges, high cost and short lifespan, have been hindering the commercialization process of low-temperature fuel cells. Professor Wei’s group has been focusing on decreasing cathode Pt loadings without losses of activity and durability, and their research advances in this area over the past three decades are briefly reviewed herein. Regarding the Pt-based catalysts and the low Pt usage, they have firstly tried to clarify the degradation mechanism of Pt/C catalysts, and then demonstrated that the activity and stability could be improved by three strategies: regulating the nanostructures of the active sites, enhancing the effects of support materials, and …


Kai Wu, The Editorial Board Member Of Journal Of Electrochemistry And Chief Scientist Of Catl, Receives The National Science And Technology Progress Award, Editorial Office Of J.Electrochem. Jul 2024

Kai Wu, The Editorial Board Member Of Journal Of Electrochemistry And Chief Scientist Of Catl, Receives The National Science And Technology Progress Award, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.


Sorbitol-Electrolyte-Additive Based Reversible Zinc Electrochemistry, Qiong Sun, Hai-Hui Du, Tian-Jiang Sun, Dian-Tao Li, Min Cheng, Jing Liang, Hai-Xia Li, Zhan-Liang Tao Jul 2024

Sorbitol-Electrolyte-Additive Based Reversible Zinc Electrochemistry, Qiong Sun, Hai-Hui Du, Tian-Jiang Sun, Dian-Tao Li, Min Cheng, Jing Liang, Hai-Xia Li, Zhan-Liang Tao

Journal of Electrochemistry

The unstable zinc (Zn)/electrolyte interfaces formed by undesired dendrites and parasitic side reactions greatly hinder the development of aqueous zinc ion batteries. Herein, the hydroxy-rich sorbitol was used as an additive to reshape the solvation structure and modulate the interface chemistry. The strong interactions among sorbitol and both water molecules and Zn electrode can reduce the free water activity, optimize the solvation shell of water and Zn2+ ions, and regulate the formation of local water (H2O)-poor environment on the surface of Zn electrode, which effectively inhibit the decomposition of water molecules, and thus, achieve the thermodynamically stable …


Optoelectronic And Morphological Surface Resistance Evaluation Of Laser-Induced Graphene Counter Electrodes For Potential Applications In Cesium Lead Halide Perovskite Solar Cells, Ziad Khalifa, Sameh Osama Abdellatif, Rami Ghannam Jul 2024

Optoelectronic And Morphological Surface Resistance Evaluation Of Laser-Induced Graphene Counter Electrodes For Potential Applications In Cesium Lead Halide Perovskite Solar Cells, Ziad Khalifa, Sameh Osama Abdellatif, Rami Ghannam

Chemical Engineering

This study investigates the physicochemical, optical, and electrical characterization of laser-induced graphene (LIG) samples for integration as counter electrodes in cesium lead halide perovskite solar cells. The impact of laser processing parameters on electrode performance is explored, including laser power, laser speed, and beam defocus. Density functional theory (DFT) computational modeling is employed for atomistic investigation and work function estimation, demonstrating the density of states (DOS), quantum capacitance of the graphene sheets, and energy work function. NiO is utilized as a hole transport layer, and the energy work function of LIG is tuned accordingly. SEM measurements estimate thin film porosity, …


Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe Jul 2024

Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe

Markey Cancer Center Faculty Publications

Werner syndrome (WS) is an autosomal recessive disease caused by loss of function of WRN. WS is a segmental progeroid disease and shows early onset or increased frequency of many characteristics of normal aging. WRN possesses helicase, annealing, strand exchange, and exonuclease activities and acts on a variety of DNA substrates, even complex replication and re- combination intermediates. Here, we review the genetics, biochemistry, and probably physiological functions of the WRN protein. Although its precise role is unclear, evidence suggests WRN plays a role in pathways that respond to replication stress and maintain genome stability particularly in telomeric regions.


Preparation Of Β-Ni (Oh)2 Nanosheet–Modified Glassy Carbon For Pseudocapacitors, Muhammad Buchari Setia Putra, Aliyah Aliyah, Afiten Rahmin Sanjaya, Respati Kevin Pramadewandaru, Hoeil Chung, Tribidasari Anggraningrum Ivandini Jun 2024

Preparation Of Β-Ni (Oh)2 Nanosheet–Modified Glassy Carbon For Pseudocapacitors, Muhammad Buchari Setia Putra, Aliyah Aliyah, Afiten Rahmin Sanjaya, Respati Kevin Pramadewandaru, Hoeil Chung, Tribidasari Anggraningrum Ivandini

Makara Journal of Science

β-Nickel hydroxide (Ni(OH)2) nanosheet–modified glassy carbon for pseudocapacitors was successfully prepared. The nanosheets were synthesized via a conventional growth seeding method combined with hydrothermal treatment. Transmission electron microscopy (TEM) characterization indicated the hexagonal structure of the nanosheets of around 15 nm in size, and X-ray diffraction (XRD) pattern confirmed the β-phase lattice crystal. These nanosheets used to modify the glassy carbon surface, increased the electroactive surface area by around 15 times. Furthermore, electrochemical investigation of the modified glassy carbon revealed an excellent performance and a specific capacitance of 628.01 F g−1 at a 1 A g−1 …


Activity Descriptors As Tools For Designing Highly Efficient Electrocatalysts For Water Splitting, Aya Gomaa Jun 2024

Activity Descriptors As Tools For Designing Highly Efficient Electrocatalysts For Water Splitting, Aya Gomaa

Theses and Dissertations

There is an uprising urge to design efficient, active, and durable catalysts to achieve sustainable hydrogen production. The unambiguity of which material should be used pushed the scientific community to devote enormous efforts in exploring different elements with different ratios on trial and error bases. However, the bridge between the theoretical calculation and the experiments introduced a new realm of designing efficient catalysts by introducing the concept of activity descriptors. In the first part of the thesis, the ability to convert waste stainless steel (SS) 316L meshes into highly efficient and durable oxygen evolution reaction (OER) catalysts is demonstrated. The …


Electrochemical Nitrate Reduction To Ammonia On Cu Based Nanoparticles Using Quantum Mechanical Simulations, Kathan Bhavin Shukla May 2024

Electrochemical Nitrate Reduction To Ammonia On Cu Based Nanoparticles Using Quantum Mechanical Simulations, Kathan Bhavin Shukla

Theses

Nitrate reduction to ammonia (NRA) is critical for environmental remediation and energy conservation, as it can remove harmful nitrate (NO3-) from water sources while producing usable ammonia (NH3). Cu represents one of the most promising non-noble-metal NRA electrocatalysts. However, the intrinsic catalytic activity of Cu facets and their influence under different pH conditions remain unclear, particularly in the presence of ions commonly found in wastewater such as Cl-, Na+, Mg2+, and Ca2+. Using density functional theory (DFT) calculations, we evaluated the nitrate reduction to ammonia (NRA) pathways …


Recent Advance In Electrochemical Dehalogenative Deuteration, Peng-Fei Li, Guang-Sheng Kou, Li-Ping Qi, You-Ai Qiu May 2024

Recent Advance In Electrochemical Dehalogenative Deuteration, Peng-Fei Li, Guang-Sheng Kou, Li-Ping Qi, You-Ai Qiu

Journal of Electrochemistry

In recent years, the incorporation of deuterium atoms into organic compounds has emerged as a vital focus in the development of pharmaceutical molecules. This trend is driven by the increasing recognition of the significance of compounds containing deuterium atoms across various domains, including materials and biopharmaceuticals, where they have found widespread applications in mechanistic studies within the realms of chemistry and biology. Meanwhile, organic electrochemistry, as a relatively environmentally friendly catalytic mode with broad adaptability to redox reactions, has emerged as a crucial alternative to traditional halogen-deuterium exchange in the context of the reduction deuteration of halides. This approach circumvents …


Comparison Of Ligands In Palladium-Catalyzed Electrochemical Allyl 4-Pyridinylation, Wei-Jie Ding, Chun-Hui Yang, Zhong-Tao Feng, Shi-Rong Lu, Xu Cheng May 2024

Comparison Of Ligands In Palladium-Catalyzed Electrochemical Allyl 4-Pyridinylation, Wei-Jie Ding, Chun-Hui Yang, Zhong-Tao Feng, Shi-Rong Lu, Xu Cheng

Journal of Electrochemistry

4-CN-pyridine is a widely applied 4-pyridinylation reagent for diverse transformations. Conventionally, the reaction proceeds via an open-shell radical cross-coupling pathway. Following our previous study, in this work, we report the Pd-catalyzed allyl 4-pyrinylation reaction under electrochemical conditions. The reaction proceeds via radical-polar crossover pathway in which the role of phosphine ligand in reactivity and selectivity was extensively investigated.


Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei May 2024

Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei

Journal of Electrochemistry

β-Amino acids have a wide range of applications in the field of pharmaceuticals. Utilizing a combination strategy of nickel catalysis and paired electrolysis, a catalytic α-arylation protocol of carbonyl compounds has been developed. This protocol affords various a-aryl-a-cyanoacetates, which can be reduced to high-value-added α-aryl-β-amino acids. The cross-coupling reaction of electron-deficient aryl bromides with a-cyanoacetates achieves the expected products with good yields and functional group compatibility under mild conditions. Excessive electron-richness in initial aryl bromides facilitates the self-coupling of desired products. DFT calculations confirm that the presence of electron-rich aryl substitutions decreases the reduction potentials of the product anions, making …


A Comprehensive Review Of Fischer-Tropsch Synthesis Processes To Produce Sustainable Diesel And Aviation Fuel, Joseph C. Steinagel May 2024

A Comprehensive Review Of Fischer-Tropsch Synthesis Processes To Produce Sustainable Diesel And Aviation Fuel, Joseph C. Steinagel

Honors College Theses

The greatest threat known to humankind today is global warming. It affects every nation on the planet and the natural order of all living things. Consequently, this ongoing crisis necessitates action to scientifically revolutionize important areas of society, including researching modern adaptations of the transportation industry. In that regard, it has been determined that an effective short-term answer to eliminating carbon emissions is to produce sustainable fuels that run cooperatively with the well-established machines of today. Sustainable aviation fuel (SAF) is one such topic of interest, and the Fischer-Tropsch synthesis process is an effective way of producing SAF. To that …


Ionic Conductivity, Li+ Transference Number, And Diffusion Coefficient Of A Solid-State Electrolyte Composite, Lizbeth Zurita May 2024

Ionic Conductivity, Li+ Transference Number, And Diffusion Coefficient Of A Solid-State Electrolyte Composite, Lizbeth Zurita

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The design of solid-state electrolyte (SSE) composites involves the fundamental study of transport properties, such as ionic conductivity. This transport property is influenced by the transport mechanisms of the charge species inside the composite, such as diffusion and migration. In this work, we perform the measurement of these three parameters through defined techniques. The resulting parameters were: ionic conductivity, the diffusion coefficient, and the Li+ transference number.


An Overview Of How To Measure The Kinetic Properties Of An Anode Material For The Chlorine Evolution Reaction, Cameron Vann May 2024

An Overview Of How To Measure The Kinetic Properties Of An Anode Material For The Chlorine Evolution Reaction, Cameron Vann

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

The process of generating chlorine gas using electrolysis in aqueous systems is well established. However, a new process requires chlorine to be generated at high temperatures using molten salt. This harsh environment requires a new study of anode materials for the chlorine evolution reaction. Anode materials can be compared by their kinetic parameters, the transfer coefficient α and the exchange current i0. The basic theory of these properties as they relate to the chlorine evolution reaction has been detailed and an analysis method for finding these effective parameters has been shown and demonstrated.


Synthesis Of Acetylene Diols With The Participation Of The Bu4noh/Dmso/H2o Catalytic Systems, Muyassar K. Salieva, Odiljon E. Ziyadullayev, Guzal K. Otamukhamedova, Rifkat F. Talipov, Lochin K. Ablakulov May 2024

Synthesis Of Acetylene Diols With The Participation Of The Bu4noh/Dmso/H2o Catalytic Systems, Muyassar K. Salieva, Odiljon E. Ziyadullayev, Guzal K. Otamukhamedova, Rifkat F. Talipov, Lochin K. Ablakulov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of this work in this study, acetylene alcohols containing heteroatomic substituents in their molecular composition- 2-(-thiophen-2-yl)but-3-yn-2-ol, 2-(3-methylthiophen-2-yl)but-3-yn-2-ol, 2-(furan-2-yl)but-3yn-2-ol, 2-(pyridin-4-yl)but-3-yn-2-ol, 2-(5-chlorothiophen-2-yl)but-3-yn-2-ol, 2-(5-bromothiophen-2yl)but-3-yn-2-ol acetylene diols were synthesized based on the reaction with acetone in a dimethyl sulfoxide solvent in the presence of the Bu4NOH/DMSO/H2O catalytic system. The influence of the molar ratio of starting materials, reaction duration, temperature, nature of the catalyst and solvents on the product yield was systematically studied. The composition, purity and structure of the new generation of synthesized acetylenediols have been confirmed by modern physicochemical methods. The mechanism of the reaction process …


Synthesis Of High Molecular Mass Resins Based On Furfuryl Alcohol, Boysayid U. Sayidov, Latif E. Jumanov, Muzaffar G. Alimukhamedov, Sherali A. Umarov, Farhod A. Magrupov May 2024

Synthesis Of High Molecular Mass Resins Based On Furfuryl Alcohol, Boysayid U. Sayidov, Latif E. Jumanov, Muzaffar G. Alimukhamedov, Sherali A. Umarov, Farhod A. Magrupov

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of the work is to study the process of synthesis of furfuryl oligomers with high molecular weight at various ratios of furfuryl alcohol and hydroxyl-containing polyether polyol. The influence of the process method on the yield of high-molecular furfuryl oligomer is shown - with a one-step synthesis method with an increase in the amount of furfuryl alcohol from 20 to 50 moles per 1 mole of polyether polyol, the yield of the final product decreases from 75% to 56%, apparently due to high exothermic effects, causing gelation systems. In contrast to the one-time introduction of the catalyst, its …


Synthesis And Technology Of Vinyl Esters Of Aromatic Carboxylic Acids Based On Vinyl Acetate, Askar B. Parmanov, Suvonkul E. Nurmanov, Saida S. Abdurakhmanova, Sarvinoz I. Tirkasheva, Begzod F. Adashev May 2024

Synthesis And Technology Of Vinyl Esters Of Aromatic Carboxylic Acids Based On Vinyl Acetate, Askar B. Parmanov, Suvonkul E. Nurmanov, Saida S. Abdurakhmanova, Sarvinoz I. Tirkasheva, Begzod F. Adashev

CHEMISTRY AND CHEMICAL ENGINEERING

In this work the vinylation reactions of aromatic carboxylic acids with vinyl acetate, which contain various substituents, in the presence of 2-chloro-4,6-dimethoxy-1,3,5-triazine were studied for the first time. The influence of the nature of the starting materials, temperature, reaction duration, solvent and reagents - zinc triflate (Zn(OTf)2, 3,3-diphenylbinaphthol (3,3'-Ph2BINOL-2Li), tertiary potassium butylate (KOtrBu), butyllithium (BuLi) for the synthesis of vinyl esters. The synthesis of vinyl esters of aromatic carboxylic acids was carried out: benzoiс, 2-phenylacetic, 4-methylbenzoic, 4-methoxybenzoic, 3,4-dimethoxybenzoic, 2-brombenzoic, 4-brombenzoic, 4-fluorobenzoic, 3-nitrobenzoic, 4-nitrobenzoic, 4-tertiary butylbenzoic, 2-chlorobenzoic, 4-chlorobenzoic, 3-hydroxybenzoic and 4-hydroxybenzoic acids has been studied. …


Synthesis Of Internal Acetylene Alcohols Based On The Sonogashira Reaction Of Terminal Acetylene Alcohols And Benzolchloride, Guzal K. Otamukhamedova, Odiljon E. Ziyadullayev, Abduvahob Ikramov, Sarvinoz I. Tirkasheva May 2024

Synthesis Of Internal Acetylene Alcohols Based On The Sonogashira Reaction Of Terminal Acetylene Alcohols And Benzolchloride, Guzal K. Otamukhamedova, Odiljon E. Ziyadullayev, Abduvahob Ikramov, Sarvinoz I. Tirkasheva

CHEMISTRY AND CHEMICAL ENGINEERING

The purpose of the study is to develop a new catalytic system for the synthesis of internal acetylene alcohols from the Sonogastric coupling reaction of terminal acetylene alcohols and benzolchloride. For the first time in this work, internal acetylene alcohols have been synthesized based on reactions of some terminal acetylene alcohols – 3,4-dimethylpentin-1-ol-3, 3,4,4-trimethylpentin-1-ol-3, 1-ethynylcyclohexanol-1, 2-ethynyladamantanol-2, 2-phenylbutin-3-ol-2, 2-(naphthyl-2)butyn-3-ol-2, 2-(furanyl-2)butyn-3-ol-2 and 2-(pyridinyl-4)butyn-3-ol-2 with chloridebenzene. In order to achieve high product productivity in the Sonogashira reaction, alternative conditions have been identified by studying the molar ratios, spatial structure, induction effects of substituents, solvent and catalyst nature, as well as temperature, reaction duration …


Thermogravimetric Analysis And Chemical Kinetics Of Waste Tires, Mahir Mohammed Said Apr 2024

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.


Enhanced Post Deposition Annealing Conditions On The Fabrication Of High Quality Thermochromic Vanadium Dioxide Films, Nuru R. Mlyuka Apr 2024

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 …


Design And Optimization Of An Azeotropic Distillation Pilot Plant For The Production Of Pure Ethanol, Samwel V. Manyele Apr 2024

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 …


Effect Of Zr And W Doping On Microstructures, Transition Temperature And Solar Transmittance Modulation Of Thermochromic W/Zr Co-Doped Vo2 Thin Films, Haji F. Haji Apr 2024

Effect Of Zr And W Doping On Microstructures, Transition Temperature And Solar Transmittance Modulation Of Thermochromic W/Zr Co-Doped Vo2 Thin Films, Haji F. Haji

Tanzania Journal of Engineering and Technology (TJET)

Thermochromic W/Zr co-doped VO2-based thin films with different concentrations of Zr were successfully deposited on soda lime glass substrates by direct current (DC) magnetron sputtering of V(99)W(01) alloy and Zr targets at a substrate temperature of 425 °C. The films were characterized by x–ray diffraction (XRD), atomic force microscopy (AFM), Rutherford backscattering spectroscopy (RBS), two-point probe and UV/VIS/NIR spectroscopy. The film’s structural properties evolution was significantly influenced by Zr concentration in the films. The transition temperature and hysteresis loop widths of the films were found to decrease with increasing Zr concentration. For the Zr concentrations of 0.21 at.%, 0.23 at.% …


Sol-Gel Synthesis And Microstructure Characterization Of Nio-Tio2 Semiconductor, Godlisten N. Shao Apr 2024

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, …