Synthesis Of Internal Acetylene Alcohols Based On The Sonogashira Reaction Of Terminal Acetylene Alcohols And Benzolchloride,
2024
Chirchik State Pedagogical University, Chirchik, Uzbekistan
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,
2024
University of Dar es Salaam
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,
2024
Department of Physics, University of Dar es Salaam, P.O. Box 35063, Dar es Salaam, Tanzania
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,
2024
Department of Chemical and Process Engineering, College of Engineering and Technology, University of Dar es Salaam, P.O. Box 35131, Dar es Salaam, Tanzania
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,
2024
Department of Natural Sciences, The State University of Zanzibar, P.O. Box 146, Zanzibar, Tanzania
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,
2024
Department of Chemistry, Mkwawa University College of Education, University of Dar es Salaam, P.O. Box 2513 Iringa, Tanzania
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, …
Sediment Characteristics And Hydrocarbon Composition Of Makukwa Seep In Southern Tanzania: Potential Implications For Subterranean Hydrocarbon Accumulation,
2024
University of Dar es salaam
Sediment Characteristics And Hydrocarbon Composition Of Makukwa Seep In Southern Tanzania: Potential Implications For Subterranean Hydrocarbon Accumulation, Makungu M. Madirisha
Tanzania Journal of Engineering and Technology (TJET)
Exploring the interplay between natural seeps and nearby sediment and hydrocarbon properties is key to unlocking subsurface hydrocarbon potential. This study presents findings on the hydrocarbon composition and sediment characteristics of the Makukwa seep in southern Tanzania, providing insight into subterranean hydrocarbon accumulation. Sediment analysis across areas A and B, located approximately 20 m apart, showed a decrease in porosity with depth, indicative of typical sandstone formations. Area A, near the seeps, exhibited porosity ranging from 23% to 36%, whereas Area B, further away, showed porosity ranging from 22% to 38%. This suggests that a lower cretaceous sandstone layer may …
Production Of Biofertilizer From Fruit And Garden Waste,
2024
Department of Chemical and Process Engineering, College of Engineering and Technology, University of Dar es Salaam, P.O. Box 351313, Dar es Salaam, Tanzania
Production Of Biofertilizer From Fruit And Garden Waste, Neema Msuya
Tanzania Journal of Engineering and Technology (TJET)
The project focused on the production of bio-fertilizer from fruit and garden waste, with a specific emphasis on utilizing pineapple tops in the composting process. The objective was to produce and assess the properties of the bio fertilizer obtained from this process and evaluate its potential application in agriculture. In this study, the composting process was done in a 0.7 m long, 0.85 wide and 1.1 m high vessel, and 0.238 m3 pineapple top wastes, resulting in 0.35 m3 of biofertilizer. The bio fertilizer produced exhibited favorable characteristics, including a moisture content of 36%, pH of 7.1, and a total …
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,
2024
Department of Mining and Mineral Processing Engineering, School of Mines and Geosciences, University of Dar es Salaam, P.O. Box 35052, Dar es Salaam, Tanzania
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 …
Study Of Reactive Distillation Equipment For Eterification Process,
2024
Shahrisabz Branch of the Tashkent Institute of Chemical Technology, Shakhrisabz, Uzbekistan
Study Of Reactive Distillation Equipment For Eterification Process, Abbos Elmanov, Abdulaziz Bakhtiyorov, Adham Norkobilov, Olimjon Maksudov, Zarif Oripov
CHEMISTRY AND CHEMICAL ENGINEERING
The purpose of this work is to study the chemical technological processes for eterification processes, and the reactive distillation unit, which carries out the reaction and separation process in one device, was chosen as the object of research. А reаctive distillаtion system is exаmined to produce for the production of Ethyl Acetate (EtAc) viа eterificаtion of acetic acid (HAc) with ethаnol. Optimizаtion methods using sensitivity analysis аre аlso conducted. Cаlculаtion of vаpor liquid equilibrium of the mixture system is done using UNIFАC model. Heat integration from the distillate stream of the column to the acid feed stream and from bottom …
Alkynylation Of Benzaldehyde And Its R-Substituted Derivatives Based On Lithium Phenylacetylenide,
2024
University of Economics and Pedagogy, Karshi, Uzbekistan
Alkynylation Of Benzaldehyde And Its R-Substituted Derivatives Based On Lithium Phenylacetylenide, Sanat B. Samatov, Odiljon E. Ziyadullayev, Abduvakhab Ikramov
CHEMISTRY AND CHEMICAL ENGINEERING
The purpose of this research work is for the first time the synthesis of the corresponding acetylene alcohols based on the alkynylation reaction of isolated benzaldehyde and its R-substituted derivatives in the BuLi/TGF system. The study proposed the reaction stages for the synthesis of acetylene alcohols in the selected BuLi/TGF system, the influence of factors influencing the process, including temperature, reaction duration and nature selected solvents. The structure of the synthesized acetylene alcohols was confirmed by modern methods of physicochemical analysis (1H NMR, 13C NMR). In addition, the effect of substituents in benzaldehyde and its R-substituted derivatives …
Electrocatalytic Cyclopropanation Of Active Methylene Compounds,
2024
State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory of Chemical Biology of Fujian Province, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China
Electrocatalytic Cyclopropanation Of Active Methylene Compounds, Liang-Hua Jie, Hai-Chao Xu
Journal of Electrochemistry
The development of novel strategies to access cyclopropanes has become increasingly important due to the vital role of these three-membered ring structures in synthetic intermediates, natural products, and pharmaceuticals. Herein, we present an electrocatalytic method for the synthesis of cyclopropanes through intermolecular dehydrogenative annulation of active methylene compounds and arylalkenes. This electrochemical process requires no chemical oxidants, allowing for a speedy access to various functionalized cyclopropanes from inexpensive and readily available materials.
Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors,
2024
Faculty of Environment & Life, Beijing University of Technology, Beijing 100124, China
Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors, Li-Yuan Lan, Yang-Ye Jiang, Raymond Daniel Little, Cheng-Chu Zeng
Journal of Electrochemistry
Aryl-substituted benzothiophene and phenanthrene are important structural units in medicinal chemistry and materials science. Although extensive effort has been devoted to prepare these compounds and a variety of approaches have been developed to construct the 2-substituted benzothiophene core structure, environmental-friendly and efficient synthetic means are still desired. Based on our previous electrochemical Minisci-type arylation reaction with aryl diazonium salt as the aryl precursor, as well as the work from König’s group, herein, we described the use of paired electrolysis to achieve 2-aryl benzothiophenes and 9-aryl phenanthrenes employing benzenediazonium salts as the aryl radical precursors. Initially, 2-methylthiobenzendiazonium salt 1a and 4-methylbenzene …
Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants,
2024
a School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants, Ju-Cai Wei, Juan Yi, Xu Wu
Journal of Electrochemistry
Zero-emission of desulfurization wastewater is one of the main demands for coal-fired power plants. As typical high salinity wastewater, it is hard to purify the desulfurization wastewater from coal-fired power plants through traditional physicochemical treatment or biochemical treatment, e.g., COD and Cl–. A high concentration of Cl– ion in desulfurization wastewater restricts wastewater reuse and zero-emission. Electrochemical technology is an attractive method for high salinity wastewater zero-emission, which provides a versatile, efficient, cost-effective, easily automatable, and clean industrial process. For advanced treatment of effluent after triple box process treatment in power plants, this paper reports an electrochemical …
Cfd Study On Two-Phase Flow Patterns In A Pipe With 90º Elbow In Different Operating Conditions,
2024
Faculty of Engineering, Tanta University
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 …
Recent Advances In Solar Photo(Electro)Catalytic Nitrogen Fixation,
2024
State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China
Recent Advances In Solar Photo(Electro)Catalytic Nitrogen Fixation, Jun-Bo Ma, Sheng Lin, Zhiqun Lin, Lan Sun, Chang-Jian Lin
Journal of Electrochemistry
Ammonia (NH3) is an essential chemical in modern society. It is currently produced in industry by the Haber-Bosch process using H2 and N2 as reactants in the presence of iron-based catalysts at high-temperature (400–600 oC) and extremely highpressure (20–40 MPa) conditions. However, its efficiency is limited to 10% to 15%. At the same time, a large amount of energy is consumed, and CO2 emission is inevitably. The development of a sustainable, clean, and environmentally friendly energy system represents a key strategy to address energy crisis and environmental pollution, ultimately aiming to achieve carbon neutrality. …
BUE
Exploring The Morphological Surface Resistance And Optical Absorption Of Thin Black Carbon Nanotube Films For Electronic And Optoelectronic Devices, Ziad Khalifa, Sameh Osama Abdellatif
Chemical Engineering
This study investigates the optical and electrical properties of thin black films of carbon nanotubes (CNTs) fabricated under various conditions to explore their potential integration as either a perfect broadband absorber or enhanced counter electrode. The study involves SEM measurements, surface resistance measurements, and UV–Vis. spectrometer analysis. The results show that the CNT thin films exhibit high electrical conductivity and strong light absorption across various wavelengths. Optically, we investigated the impact of varying the growth temperature and catalyst temperature on the absorption profile of the thin films. The fabricated and deposited CNTs showed broadband absorption spectra, reaching 92.8% of the …
The Roles Of Carbonaceous Wastes For Catalysis, Energy, And Environmental Remediation,
2024
Universiti Malaysia Sabah
The Roles Of Carbonaceous Wastes For Catalysis, Energy, And Environmental Remediation, Chi Huey Ng, Mohd Aizzan Mistoh, Siow Hwa Teo, Andrea Galassi, Hin Taufiq-Yap, Nancy Julius Siambun, Jurry Foo, Coswald Stephen Sipaut, Jeffrey Seay, Jidon Janaun
Chemical and Materials Engineering Faculty Publications
This article reviews recent studies about various generations of the carbon materials for their applications in energy and environmental remediation. The synthesis routes of the carbon materials including the condition parameters, interaction of precursors, dopants and carbon materials, as well as their physical/chemical properties are explicated first. Then, the application and mechanism of metal-free/metal-doped/non-metal-doped carbon materials are discussed in detail. Lastly, this review is ended with a summary and invigorating perspectives on the challenges and future directions at the forefront of the catalysis platform to take a step further for real application.
Biodiesel Transesterification Of Spent Coffee Grounds Using Dbu As A Catalyst: Using Dbu To Make Biodiesel From Coffee Grounds,
2024
Purdue University
Biodiesel Transesterification Of Spent Coffee Grounds Using Dbu As A Catalyst: Using Dbu To Make Biodiesel From Coffee Grounds, Christopher Stepherson, Pericles Karras, Amy Ha, Phuc Tan Nguyen, Abigail Pati, Jacob Hejazi, Soheil Hussain, Elizabeth De Young, Shuaicheng Fu
The Journal of Purdue Undergraduate Research
Coffee is one of the most universally consumed beverages. The world produces 60 million tons of spent coffee grounds (SCGs) as waste per year. Biodiesel made from SCGs is an eco-friendly alternative fuel but proves difficult to produce. 1,8-Diazabicyclo[ 5.4.0]undec-7- ene (DBU) was used as both a solvent and a catalyst with methanol to determine the efficiency of biodiesel production from SCGs. The process was completed by extracting coffee oil from acid-washed spent coffee grounds (AWSCGs) using hexane. The two extraction methods that were explored were Soxhlet and agitation. DBU is an interesting choice as a solvent and a catalyst …
Monodispersed Cu-Tcpp/Cu2O Hybrid Microspheres: A Superior Cascade Electrocatalyst Toward Co2 Reduction To C2 Products,
2024
New Energy Research Institute, School of Environment and Energy, South China University of Technology, Higher Education Mega Center, Guangzhou 510006, Guangdong, China
Monodispersed Cu-Tcpp/Cu2O Hybrid Microspheres: A Superior Cascade Electrocatalyst Toward Co2 Reduction To C2 Products, Zi-Xuan Wan, Aidar Kuchkaev, Dmitry Yakhvarov, Xiong-Wu Kang
Journal of Electrochemistry
The electrochemical conversion of carbon dioxide (CO2) into valuable chemicals is a feasible way to mitigate the negative impacts of overmuch CO2 emissions. Porphyrin-based metal organic frameworks (MOFs) are expected to be used for selective and efficient electrochemical CO2 reduction (ECR) with porous structure and ordered active sites. Herein, we report the synthesis of a monodispersed and spherical organic/inorganic hybrid Cu-TCPP@Cu2O electrocatalyst composed of Cu-TCPP (TCPP=tetrakis (4-carboxyphenyl) porphyrin) and Cu2O, where TCPP plays significant roles in regulating the morphology. In-situ formed Cu during ECR process in combination with Cu-TCPP (Cu-TCPP@Cu) can suppress …
