Chemical Engineering Commons^™

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 …

Synthesis Algorithm Of Control System Based On Neural Network For The Gas And Oil Process, Jasur Sevinov, Abdishukurov Maqsudovich Shavkat, A.Z. Shodiyorov

Chemical Technology, Control and Management

Automatic control systems in the oil and gas processing are considered. After extraction of natural gas condensate, management of technological parameters plays an important role in its processing. Among the parameter of regulating algorithms, control based on neural network technology was considered. These control systems are created on the basis of algorithms of neural network technology. There are several structures of neural networks according to their structure. Differences in the process of information processing of these branching structures are considered.

Synthesis Of Local Control Systems For Underwater Units Cleaning Bottom Sediments In Reservoirs, Yuriy Gennadiyevich Shipulin, Zebiniso Akmalovna Zayniddinova

Chemical Technology, Control and Management

The article discusses the issues of synthesizing local control systems for underwater units for cleaning bottom sediments in reservoirs. It is shown that the protection and rational use of natural reservoirs and the fight against their premature siltation is becoming an urgent task.

It is proposed to use small-sized underwater units, consisting of information and measuring devices, to carry out search work for cleaning bottom sediments under water; control systems; actuators and means of communication with humans.

It is shown that the task of controlling the loading of an underwater unit (UU) requires maintaining optimal performance while simultaneously taking into …

Dynamic Characteristics Of Magnetoelectric Linear Actuators Of Control Systems, Мakhmudjon Muxamedovich Аbdullayev, Rasul Ernazar Ogli Abdiev

Chemical Technology, Control and Management

This paper presents the results of studies carried out on magnetoelectric drives that carry out linear movement, models of drives are built and, on their basis, studies of the main indicators associated with the movement of a linear armature are carried out, such as: speed of movement, acceleration, current values, voltage and traction force of the armature. Also presented are the results of a study of magnetoelectric linear motion drives based on an analysis of graphs of their dynamic characteristics.

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

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

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

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.% …

Valorization Of The Polymeric Constituents In Plastic Wastes Through Thermo-Chemical Processes By Using Viable Metal Oxides Additives, Labeeb Ali

Thesis/ Dissertation Defenses

The rapid accumulation of different types of plastic waste necessitates the development of effective and economically viable waste management operations. Such a process should ideally not only mitigate associated environmental burdens but also recycle and recover value-added products. Through incineration or pyrolysis, thermal processing has emerged as a mainstream approach to waste management of the ever-increasing loads of different categorized plastic wastes. Throughout the work of the thesis, we have utilized a multitude of complementary techniques spanning material characterizations, catalysis, kinetic modelling, and density functional theory (DFT) to comprehend the complex chemistry that underpins catalytic chemical recycling of plastic wastes. …

Study Of Kinetics Of Hydrocarbon Gas Purification With Composite Absorbents, Oybek Aripdjanov, Shavkat Nurullaev, Shodiyakhon Azimova

CHEMISTRY AND CHEMICAL ENGINEERING

The aim of the work is to improve the process of natural gas purification from acidic components using a composite absorbent. To study the sorption of acidic components in the gas composition, a chromatographic analysis method was used. The kinetics and rate of corrosion of carbon steel grade st.10 when using composite absorbents MDEA +DEA + AVRP have been studied. The results of the study show that the volume of absorption increased from 0.55 mol/mol to 0.65 mol/mol, and the amount of H₂S in the purified gas decreased from 0.022 g/m³ to 0.014 g/m³. Corrosion …

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 …

Modeling And Performance Analysis Of Solid Oxide Fuel Cell, Mariya Pecherskaya, Khakimjan Butanov, Suhrob A. Ibodullaev, Olim Ruzimuradov, Shavkat Mamatkulov

CHEMISTRY AND CHEMICAL ENGINEERING

A three-dimensional numerical model of the system configurations of various types of solid oxide fuel cells (SOFCs) is used and the effect of parameters on SOFC performance is numerically investigated using COMSOL Multiphysics. The effect of parameters such as support layer thickness, operating temperature, and electrode porosity are shown in the polarization and power curves for each model. The results of the study showed the advantages of the anode-supported SOFC compared to cathode- and electrolyte-supported SOFC.

Theoretical calculations demonstrate the highest output power density in the anode-supported SOFC at 900 ℃, and reach a value of 0.585 W cm^{-2 …}

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 …

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, 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 …

A Tilted Broad Plume Underneath The Greenland Cratonic Keels, Dan Wang, Stephen S. Gao, Yangyang Liao, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To advance our comprehension of the complex geological history and mantle dynamics in the north atlantic region, we employ all available broadband seismic data recorded in greenland to reveal an abnormal mantle transition zone (mtz) structure. Central and eastern greenland exhibits depressed 410 and 660 km discontinuities (d410 and d660, respectively) bordering the mtz, indicative of a substantial thermal anomaly associated with an underlying plume, surpassing the 1,800°c threshold for post-garnet phase transitions at the d660. Variations in mtz thickness across greenland stem from differing temperature anomalies at the d410 and d660, possibly linked to a tilted plume within the …

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.

Transforming Fermentation Residues From Date Fruit Pomace For The Synthesis Of Bioadsorbent Material In An Integrated Biorefinery Framework, Sabeera Haris

Thesis/ Dissertation Defenses

In the pursuit of enhanced waste management solutions, this comprehensive research delves into the untapped potential of date fruit pomace (DFP), an abundant byproduct from the date syrup industry that is currently underutilized, leading to environmental concerns. The study emphasizes the need for proper waste management and valorization strategies to mitigate the environmental impact of DFP and promote sustainability within the date processing industry. The initial phase involves characterizing DFP from Emirati varieties, highlighting its compositional and functional properties. The analysis reveals that DFP is rich in total dietary fiber (45.5%), residual sugars (35.3%), protein (10.6%), ash (4.1%), and fat …

A Synergistic Approach To Outreach And Teaching: Combining Service Learning At The College Level With A Summer Hands-On Outreach Program In Chemical And Biomolecular Engineering For High School Girls, Geeta Verma, Sogol Asaei, Jacob D. Hostert, Rebecca Ahn, Julie N. Renner

Faculty Scholarship

A synergetic approach to combine service learning at the university level with a high school outreach program is described. A holistic view is presented by discussing the importance of outreach and service learning, survey results, and outcomes. Overall, it was found that the unique program increased the self-efficacy (belief about one’s abilities) of students ranging from high school to graduate level, and positively impacted the social responsibility attitudes of university student participants.

Research Of The Influence Of Physical And Chemical Properties Of Coal On The Gasification Process Using The Example Of Angren Brown Coal, Murodjon Mamitbekovich Kavkatbekov, Rakhimzhan Pachekhanovich Babakhodzhaev

Technical science and innovation

The influence of the properties of Angren brown on the process of layered gasification was studied. The dependence of the calorific value of the resulting gas on the quality characteristics of coal when using air as a gasifying agent has been established. Methods are shown for increasing the calorific value of gas obtained during the gasification process when using coal with different moisture content and different fractional composition. The features of technological processes in the reaction zones of a laboratory gas generator have been studied. Based on generally accepted methods, the volume fractions of flammable components, as well as the …