Chemical Engineering Commons^™

Damage Stability Study Of A 500 Dw Ro-Ro Ferry Vessel, Zulfaidah Ariany, Budhi Santoso, Sarwoko Sarwoko, Nauval Abdurrahman Prasetyo

Makara Journal of Technology

The development of the crossing transportation industry is currently increasing in the island areas. The use of Ro-Ro type ferry boats is extremely efficient in moving people, goods, and vehicles. The current research focuses on the damage stability of the 500 DWT Ro-Ro ferry, which aims to meet the needs of the Ro-Ro ferry in the archipelago area. The previously existing initial design of a barge hull with a main size Lpp = 40.15 m, B = 12 m, H = 3.2 m, and T = 2.15 m was used to analyze the damage stability condition further. First, the drawings …

Deep Learning Of Microstructures, Amir Abbas Kazemzadeh Farizhandi

Boise State University Theses and Dissertations

The internal structure of materials also called the microstructure plays a critical role in the properties and performance of materials. The chemical element composition is one of the most critical factors in changing the structure of materials. However, the chemical composition alone is not the determining factor, and a change in the production process can also significantly alter the materials' structure. Therefore, many efforts have been made to discover and improve production methods to optimize the functional properties of materials. The most critical challenge in finding materials with enhanced properties is to understand and define the salient features of the …

Carbon Fibers From Bio-Based Precursors Derived From Renewable Sources, Sagar Kanhere

All Dissertations

Carbon fibers have the highest strength and modulus among all known fibers and are used as reinforcements in high-performance composites [1]. Carbon fibers also have a very low density relative to metals. Therefore, carbon fibers possess ultrahigh specific strength and modulus, which make them desirable for high-performance light-weight composites. A vast majority of commercial carbon fibers are produced from PAN precursors that are expensive, which limits the use of PAN-derived carbon fibers to aerospace applications (e.g., airplanes). However, for costsensitive applications, there is a need for low-cost, moderate performance carbon fibers. Lignin is a low-cost by-product of pulping and biorefining …

Insight Into The Effects Of Cation Disorder And Surface Chemical Residues On The Initial Coulombic Efficiency Of Layered Oxide Cathode, Jin-Li Liu, Han-Feng Wu, Zhi-Bei Liu, Ying-Qiang Wu, Li Wang, Feng-Li Bei, Xiang-Ming He

Journal of Electrochemistry

Lithium layered oxide LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) is one of the most promising cathode materials in high-energy lithium-ion batteries for electric vehicles. However, one drawback for NCM622 is that its initial coulombic efficiency (ICE) is only about 87%, which is at least 6% lower than that of LiCoO₂ or LiFePO₄. In this work, we investigated the effects of surface chemical residues (e.g., LiOH and Li₂CO₃) and Li/Ni cation disorder resulted during the sintering on the ICE. We found that the ICE of the as-prepared samples could be boosted …

Sustainable Material For Urea Delivery Based On Chitosan Cross-Linked By Glutaraldehyde Saturated Toluene: Characterization And Determination Of The Release Rate Mathematical Model, Jayanudin Jayanudin, Retno S. D. Lestari, Indar Kustiningsih, Dandi Irawanto, Rozak Rozak, Reyonaldo L. A. Wardana, Fakhri Muhammad

Karbala International Journal of Modern Science

The aims of this study were to characterize the urea-loaded chitosan microspheres and determine the release kinetic constants and diffusion coefficients. An emulsion cross-linking method was used to prepare the urea-loaded chitosan microspheres. Urea was dissolved in a solution of chitosan then put into vegetable oil and stirred to form an emulsion. Glutaraldehyde saturated toluene (GST) was added into the emulsion dropwise while continuously stirring for the solidification process. Chitosan microspheres filled with urea were washed, dried, and then analyzed. Characterization of the urea-loaded chitosan microspheres was conducted using a scanning electron microscope (SEM), Raman spectroscopy, X-ray diffraction, and particle …

Synthesis Of A Phosphorus-Based Epoxy Reactive Flame Retardant Analog To Diglycidyl Ether Of Bisphenol A (Dgeba) And Its Behavior As A Matrix In A Carbon Fiber Composite, Mustafa Mukhtar

Chemical and Materials Engineering Faculty Publications

This paper describes the synthesis of a phosphorus-based flame retardant that is a chemical analog of diglycidyl ether of bisphenol A (DGEBA), as well as its incorporation as a matrix into carbon fiber laminates. Carbon fiber composites, if used for structural applications in mass transport vehicles (aircraft, trains), will require some aspects of improved fire performance to be used safely in those applications. The first phase of work involved the development of two separate synthesis routes to produce the flame retardant monomer, referred to as Phosphorus-DGEBA or simply P-DGEBA. The second step was to determine the viability of the compound's …

Fabrication Of Thin-Film Composite, Reverse-Osmosis Membranes With Polyethylenimine Modifications For Enhancing Membrane Fouling Resistance, Stephanie N. Hamilton

Master's Theses

Increasing water reuse opportunities for communities has become increasingly important as access to clean water is becoming more scarce. Reverse Osmosis (RO) is an advanced treatment technology used in water recycling wastewater for potable reuse applications. RO is a promising technology; however, the membranes have limitations including their high energy demand and their susceptibility to membrane fouling. The main objective of this study was to develop a reproducible method for the fabrication of RO membranes with enhanced flux and reduced susceptibility to fouling. Literature contains numerous publications on fabrication of thin film composite (TFC) RO membranes with high performance. However, …

Alkaline Water Electrolysis For Efficient Hydrogen Production, Wen-Fu Xie, Ming-Fei Shao

Journal of Electrochemistry

Hydrogen production from water electrolysis is a sustainable and environmentally benign strategy in comparison with fossil fuel-based hydrogen. However, this promising technique suffers from the high energy consumption and unsatisfactory cost due to the sluggish kinetics of both half reaction and inferior stability of electrocatalysts. To address this challenge, herein, we present a timely and comprehensive review on advances in alkaline water electrolysis that is already commercialized for large scale hydrogen production. The design principles and strategies with aiming to promote the performance of hydrogen generation are discussed from the view of electrocatalyst, electrode, reaction and system. The challenges and …

Electrochemical Syntheses Of Nanomaterials And Small Molecules For Electrolytic Hydrogen Production, Jia-Qi Wei, Xiao-Dong Chen, Shu-Zhou Li

Journal of Electrochemistry

Hydrogen is a clean, efficient, renewable energy resource and the most promising alternative to fossil fuels for future carbon-neutral energy supply. Therefore, sustainable hydrogen production is highly attractive and urgently demanded, especially via water electrolysis that has clean, abundant precursors and zero emission. However, current water electrolysis is hindered by the sluggish kinetics and low cost/energy efficiency of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this regard, electrochemical synthesis offers prospects to raise the efficiency and benefit of water electrolysis by fabricating advanced electrocatalysts and providing more efficient/value-adding co-electrolysis alternatives. It is an eco-friendly and facile …

Catalytic Effect Of Disordered Ru-O Configurations For Electrochemical Hydrogen Evolution, Xue Sun, Ya-Jie Song, Ren-Long Li, Jia-Jun Wang

Journal of Electrochemistry

Phase engineering is considered as an effective method for modulating the electronic structure and catalytic activity of catalysts. The disordered conformation of amorphous materials allows flexible reforming of the surface electronic structure, showing their attractiveness as catalysts for hydrogen evolution reaction (HER). Herein, we designed and developed an amorphous ruthenium dioxide (a-RuO₂) catalyst with a disordered Ru-O configuration. The conformational relationship between Ru-O ordering and HER performance is established by combining advanced electron microscopic techniques with detailed electrochemical tests. Specifically, the disordered Ru-O coordination significantly enhanced the HER catalytic activity in both acidic and alkaline media, ultimately leading …

Alkaline Seawater Electrolysis At Industrial Level:Recent Progress And Perspective, Tao Zhang, Yi-Pu Liu, Qi-Tong Ye, Hong-Jin Fan

Journal of Electrochemistry

Industrial hydrogen generation through water splitting, powered by renewable energy such as solar, wind and marine, paves a potential way for energy and environment sustainability. However, state-of-the-art electrolysis using high purity water as hydrogen source at an industrial level would bring about crisis of freshwater resource. Seawater splitting provides a practical path to solve potable water shortage, but still faces great challenges for large-scale industrial operation. Here we summarize recent developments in seawater splitting, covering general mechanisms, design criteria for electrodes, and industrial electrolyzer for direct seawater splitting. Multi-objective optimization methods to address the key challenges of active sites, reaction …

A Self-Supported Ru-Cu3P Catalyst Toward Alkaline Hydrogen Evolution, Zi-Xuan Wan, Chao-Hui Wang, Xiong-Wu Kang

Journal of Electrochemistry

Transition metal phosphide (TMP) is a kind of effective catalysts toward hydrogen evolution reaction (HER) in alkaline electrolytes. However, the performance of TMP catalysts is strongly limited by water splitting. In this work, we developed a method to prepare a copper foam (CF) supported Ru-doped Cu₃P catalyst (Ru-Cu₃P/CF) by a consecutive growth of Cu(OH)₂ nanoarrays, soaking in RuCl₃ solution and phosphorization. A large surface area was obtained by the self-supported catalysts with the appropriative Ru doping. As an excellent HER catalyst, it exhibited a low overpotential of 95.6 mV at a current density of …

Synthesis And Assembly Of Polymer Materials At Interfaces, Xiaoshuang Wei

Doctoral Dissertations

The overarching goal of the thesis is to understand growth and assembly of polymer materials at interfaces. Chapter 2 and Chapter 3 study simultaneous polymer growth and assembly at fluid interfaces, where in-situ photopolymerization and vapor phase deposition were utilized to grow polymers, respectively. Chapter 4 leverages capillary condensation to pattern polymer growth at solid substrates. Chapter 1 provides background information on polymer materials at interfaces, and vapor phase deposition method (initiated chemical vapor deposition, iCVD) to grow polymers. This chapter also reviews polymer thin film wetting, and colloidal assemblies at interfaces. In Chapter 2, we demonstrate the preparation …

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …

Fluoride Technology For Processing Copper Production Slag At Almalyk Mmc And The Possibility Of Its Application For The Synthesis Of Highly Dispersed Silica Dioxide, M Sh Kurbanov, U M. Nuraliev, J A. Panjiev, S A. Tulaganov, M Ernazarov, L S. Andriyko

Technical science and innovation

A new pilot-plant equipment of an inclined rotary furnace for the processing of fluoroammonium silicon-containing materials has been developed and manufactured, which allowed sublimation of ammonium hexafluorosilicate, formed as a result of fluorination of processed raw materials, in two sections, with autonomous control of temperature and movement of raw materials. It is shown that the use of the created equipment for the processing of copper-smelting slags of the Almalyk MMC using fluoride technology makes it possible to separate amorphous silicon dioxide in the form of a dispersed powder from slags, extract iron and obtain a collective concentrate of precious, non-ferrous …

Selective Reduction Of Trivalent Iron In Zinc Ferrite Using Elemental Sulphur, B T. Berdiyarov, Sh T. Khojiev, J B. Ismailov, S T. Matkarimov, Sh O. Ismatov

Technical science and innovation

In this article, the process laws and technological aspects of the process of sintering the zinc-containing waste of a zinc plant with technical sulfur are considered. Zinc cake is obtained during the sulfuric acid leaching of calcined zinc ores and contains about 20% zinc and additional metals such as indium, cadmium, lead and copper. Copper cakes are somewhat difficult to work with because they contain ferrites and silicates belonging to acid-resistant spinels. Since the chemical and mineralogical composition of zinc production cakes consists of complex oxides, finding ways to process them is one of the actual topics of zinc metallurgy. …

Features Designing Special Clothing For The Hot Climate Of Uzbekistan, N Kh Mirtalipova, N A. Isaxujayeva

Technical science and innovation

This paper considers the issues of establishing the relationship between the properties of fabric, clothing design and the comfort of clothing; communication of the size of the human body, allowance for free fitting, modern design when developing the design of clothing; connection of the allowance for free fitting with a suitable air gap. A diagram is given that characterizes the dependence of the comfort of clothing on its design and properties of fabrics. A mathematical model of the processes of air exchange in the underwear space is considered, which will allow obtaining more complete information and establishing more stringent dependences …

Towards Environmentally Sustainable, High-Performance, Lightweight Composites For Automotive Applications, Jasmin Zamudio Vasquez

Theses and Dissertations

The increasing public demand in the world automotive industry to improve the environmental sustainability of their manufactured vehicles without sacrificing drivers' comfort and safety and the high cost of lightweight materials have driven researchers to reconsider materials used in the automotive application. Thus, this work aims toward the production of environmentally sustainable, high-performance, lightweight composites, utilizing recycled carbon fibers (RCFs) and pyrolyzed tire particles (PTPs) reclaimed from pyro-gasification of CFRP wastes and end-of-life tires (ELTs), respectively, as reinforcements for cardanol-based epoxy resins. The fabricated composites exhibited rubbery-like behavior at 25 °C. Spectroscopic, rheological, physical, thermal, thermomechanical, and mechanical characterizations were …

Preface To Special Issue On Water Electrolysis For Hydrogen Production, Li Li, Jin-Song Hu, Zi-Dong Wei

Journal of Electrochemistry

No abstract provided.

Surface Structure Engineering Of Feni-Based Pre-Catalyst For Oxygen Evolution Reaction: A Mini Review, Jia-Xin Li, Li-Gang Feng

Journal of Electrochemistry

Oxygen evolution reaction (OER) is a significant half-reaction for water splitting reaction, and attention is directed to the high-performance non-precious catalysts. Iron nickel (FeNi)-based material is considered as the most promising pre-catalyst, that will be transferred to the real active phase in the form of high valence state metal species. Even so, the catalytic performance is largely influenced by the structure and morphology of the FeNi pre-catalysts, and lots of work has been done to optimize and tune the structure and chemical environment of the FeNi- based pre-catalysts so as to increase the catalytic performance. Herein, based on our work, …

Recent Development Of Low Iridium Electrocatalysts Toward Efficient Water Oxidation, Jing Ni, Zhao-Ping Shi, Xian Wang, Yi-Bo Wang, Hong-Xiang Wu, Chang-Peng Liu, Jun-Jie Ge, Wei Xing

Journal of Electrochemistry

Developing high-performance and low-cost electrocatalysts for oxygen evolution reaction (OER) is the key to implementing polymer electrolyte membrane water electrolyzer (PEMWE) for hydrogen production. To date, iridium (Ir) is the state-of-the-art OER catalyst, but still suffers from the insufficient activity and scarce earth abundance, which results in high cost both in stack and electricity. Design low-Ir catalysts with enhanced activity and stability that can match the requirements of high current and long-term operation in PEMWE is thus highly desired, which necessitate a deep understanding of acidic OER mechanisms, unique insights of material design strategies, and reliable performance evaluation norm, especially …

Perovskite-Type Water Oxidation Electrocatalysts, Xiao Liang, Ke-Xin Zhang, Yu-Cheng Shen, Ke Sun, Lei Shi, Hui Chen, Ke-Yan Zheng, Xiao-Xin Zou

Journal of Electrochemistry

The development of energy conversion/storage technologies can achieve the reliable and stable renewable energy supply, and bring us a sustainable future. As the core half-reaction of many energy-related systems, water oxidation is the bottleneck due to its sluggish kinetics of the four-concerted proton-electron transfer (CPET) process. This necessitates the exploitation of low cost, highly active and stable water oxidation electrocatalysts. Perovskite-type oxides possess diverse crystal structures, flexible compositions and unique electronic properties, enabling them ideal material platform for the optimization of catalytic performance. In this review, we provide a comprehensive summary for the crystal structures, electronic structures and synthetic methods …

The Rapid Preparation Of Efficient Mofeco-Based Bifunctional Electrocatalysts Via Joule Heating For Overall Water Splitting, Ao Zhou, Wei-Jian Guo, Yue-Qing Wang, Jin-Tao Zhang

Journal of Electrochemistry

Water electrolysis is an available way to obtain green hydrogen. The development of highly efficient electrocatalysts is a current research hotspot for water splitting, but it remains challenging. Herein, we demonstrate the synthesis of a robust bifunctional multi-metal electrocatalysts toward water splitting via the rapid Joule-heating conversion of metal precursors. The composition and morphology were well regulated via altering the ratio of metal precursors. In particular, the trimetal MoC/FeO/CoO/carbon cloth (CC) electrode revealed the outstanding bifunctional electrocatalytic performance due to the unique composition and large electrochemical active surface area. Typically, the MoC/FeO/CoO/CC catalyst needed low overpotentials of 121 and 268 …

A Co Porphyrin With Electron-Withdrawing And Hydrophilic Substituents For Improved Electrocatalytic Oxygen Reduction, Hong-Bo Guo, Ya-Ni Wang, Kai Guo, Hai-Tao Lei, Zuo-Zhong Liang, Xue-Peng Zhang, Rui Cao

Journal of Electrochemistry

Understanding factors that influence the catalyst activity for oxygen reduction reaction (ORR) is essential for the rational design of efficient ORR catalysts. Regulating catalyst electronic structure is commonly used to fine-tune electrocatalytic ORR activity. However, modifying the hydrophilicity of catalysts has been rarely reported to improve ORR, which happens at the liquid/gas/solid interface. Herein, we report on two Co porphyrins, namely, NO₂-CoP (Co complex of 5,10,15,20-tetrakis(4-nitrophenyl)porphyrin) and 5F-CoP (Co complex of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin), and their electrocatalytic ORR features. By simultaneously controlling the electronic structure and hydrophilic property of the meso-substituents, the NO₂-CoP showed higher electrocatalytic activity than …

Effect Of Current Density Ramping On The Anodic Reaction And Morphology Of Aerospace Aluminum Alloys, Peter Totaro Jr.

Dissertations

Aluminum anodizing has been experimented with and studied over the last century because of its ability to form uniform, well ordered cellular coatings on aluminum alloys. Anodizing aerospace alloys has been problematic, due to the alloying elements used to add strength and resistance to stress cracking corrosion. These intermetallic compounds, i.e., copper and zinc, promote oxygen evolution and stress as they accumulate in and on the surface of the forming aluminum oxide. These inclusions lead to increased electrical resistance that forms porous and flawed coating, which can lead to industrial and field failures. The amount of voltage placed on the …

Evaluation Of Material Request Order To Support Sustainable Construction, Fajar Susilowati, Nur Nahdiah Anggraeni

Makara Journal of Technology

This study was conducted on one of Indonesia’s apartment projects, in which reinforced concrete is the main structure. Based on existing project data, this project experienced a decline in the construction work’s progress, thus reducing the project’s overall progress. This decline occurred because the delivery of concrete reinforcement material was delayed. This study aimed to determine the process of material request order and its relationship with the work implementation, as well as the factors that influenced the delayed arrival of concrete reinforcement material at the project site. The method used in this study was observation and interview. Data were analyzed …

Facile One-Step Solid-State Synthesis Of Ni-Rich Layered Oxide Cathodes For Lithium-Ion Batteries, Jing-Yue Wang, Rui Wang, Shi-Qi Wang, Li-Fan Wang, Chun Zhan

Journal of Electrochemistry

Nickel-rich layered oxide is one of the dominate cathode materials in the lithium ion batteries, due to its high specific energy density meeting the range requirement of the electric vehicles. Typically, the commercial Ni-rich layered oxides are synthesized from co-precipitated precursors, while precision control is required in the co-precipitation process to ensure the atomic level mixing of the cations such as Ni, Co and Mn, et.al. In this work, a one-step solid-state method was successfully applied to synthesize the Ni-rich layered oxide materials with ultra-high Ni content. By choosing the nickel hydroxides as the precursor with layered structure similar to …

Low-Crystallinity And Heterostructured Aupt-Ru@Cnts As Highly Efficient Multifunctional Electrocatalyst, Tuan-Jie Gan, Jian-Ping Wu, Shi Liu, Wen-Jun Ou, Bin-Ling Bin-Ling, Xiong-Wu Kang

Journal of Electrochemistry

The catalytic activity of the catalysts is strongly dependent on the structure of the catalysts, and the exploration of their correlation and structure-controlled synthesis of the high-performance catalysts are always at the central. Currently, platinum (Pt) is the optimum catalyst for hydrogen evolution reaction (HER), oxygen reduction reaction (ORR) and alcohol oxidation reaction, while ruthenium (Ru) behaves as the champion catalyst for oxygen evolution reaction (OER) during water splitting. Preparing alloy catalysts with these precious metals can modulate the catalytic activity of these catalysts from the perspective of strain effect, ensemble effect and ligand effect. Here, we developed a strategy …

Identification Of Lithocholic Acid As A Molecular Glass Host For Room-Temperature Phosphorescent Materials, John J. Flynn, Zachary M. Marsh, Douglas M. Krein, Steven M. Wolf, Joy E. Haley, Erick S. Vasquez, Thomas M. Cooper, Nicholas P. Godman, Tod A. Grusenmeyer

Chemical and Materials Engineering Faculty Publications

Lithocholic acid was identified as a molecular glass host material for room temperature phosphorescent (RTP) chromophores. Differential scanning calorimetry (DSC) was performed on a series of structurally similar, biologically sourced molecules, including lithocholic acid, β-estradiol, cholesterol, and β-sitosterol, in an effort to identify new amorphous molecular glasses independent of plasticizing additives. DSC analysis revealed lithocholic acid and β-estradiol form stable molecular glasses post thermal processing unlike neat cholesterol and β-sitosterol. The ability of lithocholic acid and β-estradiol to stabilize high wt. % loadings of d10-pyrene and a mixture of d10-pyrene and an iridium chromophore, bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate iridium(III) (FIr6), was also investigated. …

Biobased Packaging Materials From Cellulose Nanofibrils Produced From Virgin Wood Pulp Or Recycled Cardboard Pulp, Md Ikramul Hasan

Electronic Theses and Dissertations

Self-standing cellulose nanofibril (CNF) films are regarded as one of the promising alternatives to current petroleum-based packaging materials. The mechanical and barrier properties of CNF films are not yet up to the mark for certain applications, especially at high relative humidity. Those properties of CNF films can be tuned by the drying methods of films, degree of fibrillation, cross-linking, and controlled shrinkage. A comprehensive understanding of these processes and their influence on the structure and properties of CNF films have been presented in this thesis.

First, we prepared CNF films from CNF suspensions with two different degrees of fibrillation- standard …