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Articles 2491 - 2520 of 14122

Full-Text Articles in Engineering

Partially Oxidative Torrefaction Of Woody Biomass Pellets: Burning Behaviour And Emission Analysis, Sajid Riaz, Yasir M. Al-Abdeli, Ibukun Oluwoye Jan 2023

Partially Oxidative Torrefaction Of Woody Biomass Pellets: Burning Behaviour And Emission Analysis, Sajid Riaz, Yasir M. Al-Abdeli, Ibukun Oluwoye

Research outputs 2022 to 2026

Non-conventional torrefaction under partially oxidative conditions is an emerging cost-effective thermochemical pre-treatment method to improve the quality of biomass for energy applications. The literature lacks data on the combustion of biomass torrefied under oxygen-deficient atmosphere with actual reactor conditions (inevitable non-uniformities in the thermal environment). In this work, a dual mode fixed-bed biomass (torrefaction) reactor and combustor was operated on Australian biomass pellets, to torrefy the fuels at 275 °C for 30 min using partially oxidative atmosphere (O2: 5 vol %, balance N2) and then to combust them. Combustion behaviour with a particular focus on gaseous …

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Using Magnesium Oxide Nanoparticles In A Magnetic Field To Enhance Oil Production From Oil-Wet Carbonate Reservoirs, F. Amrouche, M. J. Blunt, Stefan Iglauer, M. Short, T. Crosbie, E. Cordero, D. Xu Jan 2023

Using Magnesium Oxide Nanoparticles In A Magnetic Field To Enhance Oil Production From Oil-Wet Carbonate Reservoirs, F. Amrouche, M. J. Blunt, Stefan Iglauer, M. Short, T. Crosbie, E. Cordero, D. Xu

Research outputs 2022 to 2026

Enhanced oil production can maximise yield from depleted reservoirs, and in the face of dwindling global oil reserves can reduce the need for exploratory drilling during the transition away from fossil fuels. A hybrid technique, merging a magnetic field (MF) and magnesium oxide (MgO) nanoparticles (NPs), was investigated as a potential method of enhancing oil production from oil-wet carbonate reservoirs. The impact of this hybrid technique on rock wettability, zeta potential, and interfacial tension was also investigated. Displacement experiments were carried out on oil-wet Austin chalk – a laboratory carbonate rock analogue – using MgO NPs in deionized water (DW) …

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Splitting Tensile Strength Of Recycled Tire Steel Fiber-Reinforced Alkali-Activated Slag Concrete Designed By Taguchi Method, Milad Eskandarinia, Mina Esmailzade, Farhad Aslani Jan 2023

Splitting Tensile Strength Of Recycled Tire Steel Fiber-Reinforced Alkali-Activated Slag Concrete Designed By Taguchi Method, Milad Eskandarinia, Mina Esmailzade, Farhad Aslani

Research outputs 2022 to 2026

Despite offering several benefits in terms of environment and economics, few studies were conducted on the ground granulated blast furnace slag (GGBFS) based alkali-activated concrete reinforced with recycled tire steel fibers (RTSFs). Therefore, this paper employed the Taguchi method to investigate and optimize the influence of GGBFS content, the alkaline solution to GGBFS content ratio, sodium hydroxide solution concentration, and RTSF volume fraction on splitting tensile strength (STS) of recycled tire steel fiber-reinforced alkali-activated slag concrete (RTSFR-AASC). The microstructural evaluation was done through scanning electron microscopy, and Fourier transform infrared spectroscopy (FTIR) analyses. The results indicated that the fiber content, …

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Size Distribution, Elemental Composition And Morphology Of Nanoparticles Separated From Respirable Coal Mine Dust, Shoeleh Assemi, Lei Pan, Xuming Wang, Titilayo Akinseye, Jan D. Miller Jan 2023

Size Distribution, Elemental Composition And Morphology Of Nanoparticles Separated From Respirable Coal Mine Dust, Shoeleh Assemi, Lei Pan, Xuming Wang, Titilayo Akinseye, Jan D. Miller

Michigan Tech Publications, Part 1

Nanoparticles, defined as particles with one dimension below 100 nm, contribute little to the total mass concentration in respirable coal mine dust (RCMD) toxicological studies, but they could have a considerable part in the adverse health effects by RCMD inhalation. It has been shown that inhaled nanoparticles can penetrate deep into the lung and could plausibly contribute to acute and chronic pulmonary diseases by triggering oxidative stress formation and inducing inflammation. RCMD nanoparticles from samples collected in an underground mine in the United States were analyzed by a particle separation technique, field-flow fractionation (FFF), for size, morphology, and elemental composition. …

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Heterogeneous Microstructure And Mechanical Behaviour Of Al-8.3fe-1.3v-1.8si Alloy Produced By Laser Powder Bed Fusion, S. J. Yu, P. Wang, H. C. Li, R. Setchi, M. W. Wu, Z. Y. Liu, Z. W. Chen, S. Waqar, Lai-Chang Zhang Jan 2023

Heterogeneous Microstructure And Mechanical Behaviour Of Al-8.3fe-1.3v-1.8si Alloy Produced By Laser Powder Bed Fusion, S. J. Yu, P. Wang, H. C. Li, R. Setchi, M. W. Wu, Z. Y. Liu, Z. W. Chen, S. Waqar, Lai-Chang Zhang

Research outputs 2022 to 2026

The relationship between processing parameters, microstructure, and mechanical properties of Al-8.3Fe-1.3V-1.8Si alloy processed by laser powder bed fusion is seldom studied. Therefore, fully dense alloys with two parameters were selected to investigate this key issue. The results show that the alloy with low power and scanning speed (S200) shows fan-shell-shaped melt pools and laser tracks while another (S350) shows a deeper and wider melt pool. Both alloys obtain a heterogeneous microstructure without a secondary phase in melt pool (MP) and a nano-sized phase in melt pool boundary (MPB). The difference between solid-solution strengthening and Orowan strengthening in MP and MPB …

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Artifacts In Localised Multivariate Uniform Conditioning: A Case Study, Oscar Rondon, Hassan Talebi Jan 2023

Artifacts In Localised Multivariate Uniform Conditioning: A Case Study, Oscar Rondon, Hassan Talebi

Research outputs 2022 to 2026

Localised Multivariate Uniform Conditioning (LMUC) is a technique designed for spatially locating Selective Mining Unit (SMU) grades derived using Multivariate Uniform Conditioning (MUC) for the assessment of recoverable resources. LMUC has the advantage of producing SMU estimates conforming to the MUC panel-specific grade-tonnage curves while preserving the spatial grade distribution at the selective mining level. However, LMUC results have two severe artifacts. This paper documents both artifacts using four grades from a large nickel–cobalt laterite deposit in Western Australia.

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Natural Manganese Ores For Efficient Removal Of Organic Pollutants Via Catalytic Peroxymonosulfate-Based Advanced Oxidation Processes, Zhengxin Yao, Roufei Chen, Ning Han, Hongqi Sun, Ngie Hing Wong, Lusi Ernawati, Shaobin Wang, Jaka Sunarso, Shaomin Liu Jan 2023

Natural Manganese Ores For Efficient Removal Of Organic Pollutants Via Catalytic Peroxymonosulfate-Based Advanced Oxidation Processes, Zhengxin Yao, Roufei Chen, Ning Han, Hongqi Sun, Ngie Hing Wong, Lusi Ernawati, Shaobin Wang, Jaka Sunarso, Shaomin Liu

Research outputs 2022 to 2026

Peroxymonosulfate-based advanced oxidation processes (PMS-AOPs) for in situ persistent organic pollutant (POP) remediation in aqueous solutions can be a promising technology. However, this technology is constrained by its high toxicity and cost of metal oxide and non-metal catalysts for PMS activation. Here, we investigated the catalytic performance of a widely available natural mineral, manganese ore (MO), for PMS activation. A series of natural MO samples in an aqueous solution were prepared via the Fenton-like reaction. The samples' crystalline structure, surface morphology, textural properties, and other surface characteristics of the selected MO were systematically characterized. The effects of PMS concentration and …

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Photocatalytic Reforming Of Lignocellulose: A Review, Xinyuan Xu, Lei Shi, Shu Zhang, Zhimin Ao, Jinqiang Zhang, Shaobin Wang, Hongqi Sun Jan 2023

Photocatalytic Reforming Of Lignocellulose: A Review, Xinyuan Xu, Lei Shi, Shu Zhang, Zhimin Ao, Jinqiang Zhang, Shaobin Wang, Hongqi Sun

Research outputs 2022 to 2026

Biomass has been considered as a promising energy resource to combat the exhaustion of fossil fuels, as it is renewable, sustainable, and clean. Photocatalytic reforming is a novel technology to utilize solar energy for upgrading biomass in relatively mild conditions. This process efficiently reforms and recasts biomass into hydrogen and/or valuable chemicals. To date, lignocellulose, including cellulose, hemicellulose and lignin, has attracted extensive studies in facile photocatalytic valorisation. This review summarizes and analyzes the most recent research advances on photoreforming of lignocellulose to provide insights for future research, with a particular emphasis on the reformation of lignin because of its …

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Role Of Air Staging In A Batch-Type Fixed Bed Biomass Combustor Under Constant Primary Air, Awais Junejo, Yasir M. Al-Abdeli, Jacobo Porteiro Jan 2023

Role Of Air Staging In A Batch-Type Fixed Bed Biomass Combustor Under Constant Primary Air, Awais Junejo, Yasir M. Al-Abdeli, Jacobo Porteiro

Research outputs 2022 to 2026

Staged combustion of biomass is the most suitable thermo-chemical conversion for achieving lower gaseous emissions and higher fuel conversion rates. In a staged fixed bed combustion of biomass, combustion air is supplied in two stages. In the first stage, primary air is provided below the fuel, whereas in the later stage, secondary air is supplied in the freeboard region. The available literature on the effects of air staging (secondary air location) at a constant primary air flow rate on combustion characteristics in a batch-type fixed bed combustor is limited and hence warrants further investigations. This study resolves the effect of …

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Experimental Study On The Mechanical Controlling Factors Of Fracture Plugging Strength For Lost Circulation Control In Shale Gas Reservoir, Chengyuan Xu, Lingmao Zhu, Feng Xu, Yili Kang, Haoran Jing, Zhenjiang You Jan 2023

Experimental Study On The Mechanical Controlling Factors Of Fracture Plugging Strength For Lost Circulation Control In Shale Gas Reservoir, Chengyuan Xu, Lingmao Zhu, Feng Xu, Yili Kang, Haoran Jing, Zhenjiang You

Research outputs 2022 to 2026

The geological conditions of shale reservoir present several unique challenges. These include the extensive development of multi-scale fractures, frequent losses during horizontal drilling, low success rates in plugging, and a tendency for the fracture plugging zone to experience repeated failures. Extensive analysis suggests that the weakening of the mechanical properties of shale fracture surfaces is the primary factor responsible for reducing the bearing capacity of the fracture plugging zone. To assess the influence of oil-based environments on the degradation of mechanical properties in shale fracture surfaces, rigorous mechanical property tests were conducted on shale samples subsequent to their exposure to …

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Evaluating The Impact Of Increased Cycling On Thermal Power Plants Due To Wind Energy Penetration In The Midwest: A Case Study, Joscelyne Larson Jan 2023

Evaluating The Impact Of Increased Cycling On Thermal Power Plants Due To Wind Energy Penetration In The Midwest: A Case Study, Joscelyne Larson

Electronic Theses and Dissertations

One of the most significant shifts in the mix of U.S. electricity generation over the past few years has been the rapid expansion of renewable energy resources, especially solar and wind. However, fossil fuels are still necessary to fulfill the world’s energy requirements. Despite efforts to increase the use of renewable energy sources, these sources can be at times unreliable, causing countries around the world to continue to rely on base load units such as coal and natural gas. This decrease in fossil fuels and increase in renewable energy sources presents many complex issues in terms of power system planning, …

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Development Of Polymeric Sorbents As Reusable Filtration Systems For Remediation Of Pfas Contaminated Water, E. Molly Frazar Jan 2023

Development Of Polymeric Sorbents As Reusable Filtration Systems For Remediation Of Pfas Contaminated Water, E. Molly Frazar

Theses and Dissertations--Chemical and Materials Engineering

Decades of use of per- and polyfluoroalkyl substances (PFAS) in a multitude of consumer and industry-based products have led to a devastating amount of soil and water contamination. Although these chemicals and compounds possess advantageous qualities – such as that of PFAS in the role of fire-fighting foams that have no doubt saved countless lives and homes, we must take responsibility for the anthropogenic hazards that threaten our global health. This entails being able to cost-effectively remediate problems created in the past from overuse of toxic substances that could negatively impact our future, and in this case, the future of …

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Mechanical And Adhesive Properties Of Supramolecular, Mussel-Inspired Hydrogels, Daniel Darby Jan 2023

Mechanical And Adhesive Properties Of Supramolecular, Mussel-Inspired Hydrogels, Daniel Darby

Theses and Dissertations--Chemical and Materials Engineering

The exceptional mechanical and adhesive properties of mussel byssal threads come from supramolecular interactions of ligands found in the proteins comprising them. Ligands can form hydrophobic interactions, π-π stacking interactions, and hydrogen bonds, but the strongest supramolecular interaction they demonstrate is metal-ligand coordination. Specifically, Histidine (His-) and nitrodopamine (nDOPA) ligands coordinate to metals in a bidentate fashion and take on tris-, bis-, and mono- modalities (3, 2, or 1 ligand per ion, respectively). The distribution of these modalities is controlled by equilibrium thermodynamics. These same ligands can be used as crosslinks in supramolecular hydrogel networks. Supramolecular hydrogel networks are dissipative, …

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Molecular Understanding Of Zwitterions And Quantum Computing For Sustainability, Manh Tien Nguyen Jan 2023

Molecular Understanding Of Zwitterions And Quantum Computing For Sustainability, Manh Tien Nguyen

Theses and Dissertations--Chemical and Materials Engineering

The sustainable development of society needs sustainable energy solutions and the mitigation of greenhouse gas emissions. One key subject in this area is the development of safe and efficient ion-based batteries. Moreover, CO2 capture is a crucial pathway in mitigating emissions from the combustion of fossil fuels. Ongoing efforts are to improve both technologies' safety and efficiency. This thesis presents our efforts to conduct computational research on understanding advanced zwitterionic electrolytes and CO2 capture. Chapters 2-4 illustrate the computational research to understand ionic solvation in zwitterionic electrolytes. Solid-state electrolytes are essential for safer batteries. While solid polymer electrolytes …

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Developing And Modeling Tunable Nanofiltration And Functionalized Membranes For The Separation Of Organics And Inorganics From Water: Per- And Polyfluoroalkyl Substances, Lanthanides, And More, Francisco Cecil Leniz-Pizarro Jan 2023

Developing And Modeling Tunable Nanofiltration And Functionalized Membranes For The Separation Of Organics And Inorganics From Water: Per- And Polyfluoroalkyl Substances, Lanthanides, And More, Francisco Cecil Leniz-Pizarro

Theses and Dissertations--Chemical and Materials Engineering

In a world where clean water predictability is challenged by both global warming and the contamination of our natural resources, it is our responsibility to advance water separation technologies into more efficient processes and to lessen their environmental footprint. Pore and surface functionalization of membranes can enhance the separation of ions from water and even help overcome intrinsic challenges that some current separation technologies possess. If we begin with a complete fundamental understanding of the nanoscale interactions that occur in the process of separating ions from water, then we can engineer new functionalized composite membranes to provide alternative processes keeping …

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Leveraging Cell-Substrate Adhesion And Cell Migratory Properties In Skeletal Muscle Constructs And Cancer Metastasis Assays, Lauren E. Mehanna Jan 2023

Leveraging Cell-Substrate Adhesion And Cell Migratory Properties In Skeletal Muscle Constructs And Cancer Metastasis Assays, Lauren E. Mehanna

Theses and Dissertations--Chemical and Materials Engineering

Volumetric muscle loss (VML) remains one of the few skeletal muscle injuries without a reliable and repeatable treatment. In large volume muscle injuries, muscle fibers as well as the surrounding connective tissue are damaged, preventing therapeutic muscle stem cells, called myogenic progenitor cells (MPCs), from reaching the injury site and initiating repair. There is a clinical need to rapidly fabricate in vitro muscle tissue constructs that mimic the native tissue organization, with aligned myotubes, for insertion and integration at the patient’s injury site. In this dissertation, we utilize the MPC’s natural propensity to close gaps across an injury site to …

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Model Based Systems Engineering Approaches To Chemicals And Materials Manufacturing, Quang Le Jan 2023

Model Based Systems Engineering Approaches To Chemicals And Materials Manufacturing, Quang Le

Theses and Dissertations

Model-based systems engineering (MBSE) is part of a long-term trend toward model-centric approaches adopted by many engineering disciplines. This work establishes the need for an MBSE approach by reviewing the importance, complexity, and vulnerability of the U.S. chemical supply chains. The origins, work processes, modeling approaches, and supporting tools of the systems engineering discipline (SE) are discussed, along with the limitations of the current Process Systems Engineering (PSE) framework. The case is made for MBSE as a more generalizable and robust approach. Systems modeling strategies for MBSE are introduced, as well as a novel MBSE method that supports the automation …

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Mechanisms Of Emulsion Destabilization: An Investigation Of Surfactant, Stabilizer, And Detergent Based Formulations Using Diffusing Wave Spectroscopy, Jordan N. Nowaczyk Jan 2023

Mechanisms Of Emulsion Destabilization: An Investigation Of Surfactant, Stabilizer, And Detergent Based Formulations Using Diffusing Wave Spectroscopy, Jordan N. Nowaczyk

Theses and Dissertations

Conventional approaches for studying emulsions, such as microscopy and macroscopic phase tracking, present challenges when it comes to establishing detailed mechanistic descriptions of the impact of emulsifier and stabilizer additives. Additionally, while a combination of sizing methods and macroscopic phase tracking can provide insights into droplet size changes and concentration, the use of multiple measurements can be cumbersome and error-prone. It is the focus of this work, to present a new method for studying water in oil (W/O) emulsions that involves using diffusing wave spectroscopy (DWS) to examine the impact of three different surface stabilizing additives at varying concentrations. By …

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Thermal Analysis Of Thermal Shield For Pip-Ii Ssr1 Cryomodule, Victor Aguado Rodriguez Jan 2023

Thermal Analysis Of Thermal Shield For Pip-Ii Ssr1 Cryomodule, Victor Aguado Rodriguez

Graduate Research Theses & Dissertations

Fermilab's PIP-II project plans to enhance the onsite accelerator into the world's most intense neutrino beam, bringing Fermilab into the next generation of particle accelerators. The five different types of cryomodules are vital parts of the PIP-II project and each requires numerous engineering analyses to prove operation. For example, the thermal shield of the Single Spoke Resonator-1 (SSR1) cryomodule required a thermal analysis to ensure the design was operating as intended before fabrication commenced. The thermal shield is cooled by the supercritical helium inside of the extrusion and must remain between 45 and 80 Kelvin. The main purpose of the …

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Outstanding Advantages, Current Drawbacks, And Significant Recent Developments In Mechanochemistry: A Perspective View, Silvina Pagola Jan 2023

Outstanding Advantages, Current Drawbacks, And Significant Recent Developments In Mechanochemistry: A Perspective View, Silvina Pagola

Chemistry & Biochemistry Faculty Publications

Although known since antiquity, mechanochemistry has remained dormant for centuries. Nowadays, mechanochemistry is a flourishing research field at the simultaneous stages of gathering data and (often astonishing) observations, and scientific argumentation toward their analysis, for which the combination of interdisciplinary expertise is necessary. Mechanochemistry’s implementation as a synthetic method is constantly increasing, although it remains far from being fully exploited, or understood on the basis of fundamental principles. This review starts by describing many remarkable advantages of mechanochemical reactions, simplifying and “greening” chemistry in solutions. This description is followed by an overview of the current main weaknesses to be addressed …

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More On The Demons Of Thermodynamics, Daniel P. Sheehan, Garret Moddel, James W. Lee Jan 2023

More On The Demons Of Thermodynamics, Daniel P. Sheehan, Garret Moddel, James W. Lee

Chemistry & Biochemistry Faculty Publications

No abstract provided.

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Investigation Of Recrosslinkable Preformed Particle Gels For Natural Gas Conformance Control, Ali Abdulmohsen Al Brahim Jan 2023

Investigation Of Recrosslinkable Preformed Particle Gels For Natural Gas Conformance Control, Ali Abdulmohsen Al Brahim

Doctoral Dissertations

"Recross linkable Preformed Particle Gel (RPPG) is a novel type of preformed particle gel in which particles can bond together to form a strong bulk gel system after being placed in the target formation. In this research, I systematically evaluated the feasibility of using this product to improve gas flooding conformance for mature reservoirs with conduits or fractures. Two RPPG systems were used for the experiment: a CO2- resistant RPPG (CR-RPPG) synthesized using acrylamide (AM) and 2-acrylamide-2- methylpropane sulfonate acid (AMPS), designed for CO2 flooding; and an acrylamide-co-acrylic acid-based RPPG (LT-RPPG), designed for water flooding. Different experimental apparatuses …

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Microencapsulation Of Holy Basil Oil Using Modified Starch By Spray Drying Method, Artima Lairattanakul Jan 2023

Microencapsulation Of Holy Basil Oil Using Modified Starch By Spray Drying Method, Artima Lairattanakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Holy basil is a local herb that can planted all over Thailand. It is the significant ingredient in Thai famous dish named “Pad ga prao” because of its unique scent which is released when cooked. Apart from the cuisine, its essential oil has been used in various industries including cosmetics, perfumery, and pharmaceuticals. However, their degradation under light, moisture, and high temperature during storage is the main problem of their utility. In this research, the encapsulation process is selected to prevent the problem. The modified starch was used as wall materials. Holy basil oil (HBO) has three main components: Eugenol, …

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Effect Of Rice Straw Loading On Morphological, Thermal, Gas Barrier, And Mechanical Properties Of Poly(Lactic Acid)/Poly(3-Hydroxybutyrate-Co-4-Hydroxybutyrate) Blend Films, Danaipat Tuangwattanasin Jan 2023

Effect Of Rice Straw Loading On Morphological, Thermal, Gas Barrier, And Mechanical Properties Of Poly(Lactic Acid)/Poly(3-Hydroxybutyrate-Co-4-Hydroxybutyrate) Blend Films, Danaipat Tuangwattanasin

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research focuses on enhancing the properties of polylactic acid (PLA), a biodegradable polymer known for its potential in mitigating waste accumulation issues. The inherent brittleness of PLA poses a significant challenge. To overcome this limitation, the study explores the incorporation of the biodegradable polymer poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB) into PLA. The PLA/P3HB4HB blend films were prepared by varying compositions from 100/0 to 60/40 wt/wt and using compression molding. The investigations indicated that the PLA/P3HB4HB 90/10 blend film exhibits superior properties, such as synergistic toughness and increased %strain. Rice straw (RS) fiber is introduced as a reinforcing fiber in the blends, expanding …

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Tarnish Resistance Of Silver Reinforced With Carbon Material To Artificial Sweat And Hydrogen Sulfide, Kunthida Chanthaban Jan 2023

Tarnish Resistance Of Silver Reinforced With Carbon Material To Artificial Sweat And Hydrogen Sulfide, Kunthida Chanthaban

Chulalongkorn University Theses and Dissertations (Chula ETD)

Due to its immense popularity, silver jewelry has undergone continual development, it an intriguing product. The most significant issue with silver jewelry is the tarnish of the silver metal's surface. Therefore, using a coin making technique, the study team evaluated the properties of silver metal reinforced by carbon materials. To evaluate the silver's to sweat and hydrogen sulfide tarnishing. Effects of adding carbon to samples after performing an artificial sweat test. It was discovered that the use of highly scattered carbon improved the ability to remove tarnish from fake sweat because it reduced the surface area of the silver (Ag) …

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Activity And Stability Of Tio2-Encapsulated Cspbbr3/Cs4pbbr6 For Photocatalytic Degradation Of Rhodamine B, Nutzeya Plainoen Jan 2023

Activity And Stability Of Tio2-Encapsulated Cspbbr3/Cs4pbbr6 For Photocatalytic Degradation Of Rhodamine B, Nutzeya Plainoen

Chulalongkorn University Theses and Dissertations (Chula ETD)

Due to the excellent optoelectronic performance of cesium lead bromide(CsPbBr3), it has shown promising potential as a photocatalyst for the degradation of organic compounds under sunlight. During the synthesis of CsPbBr3, Cs4PbBr6, another formation of CsPbBr3, is also produced, which exhibits desirable properties such as strong and narrow photoluminescence (PL) and enhanced thermal stability. In this study, we successfully synthesized a mixture of CsPbBr3/Cs4PbBr6 nanoparticles using a simple precipitation method. However, the stability of CsPbBr3/Cs4PbBr6 was found to be sensitive to high temperatures, moisture, and oxygen, which could affect its photocatalytic degradation performance. To enhance both stability and activity, we …

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Effect Of Type And Concentration Of Acid On Characteristics Of Functionalized Biochar And Its Performance In Converting Fructose To 5-Hmf, Pimlapas Bunwichian Jan 2023

Effect Of Type And Concentration Of Acid On Characteristics Of Functionalized Biochar And Its Performance In Converting Fructose To 5-Hmf, Pimlapas Bunwichian

Chulalongkorn University Theses and Dissertations (Chula ETD)

Biomass, with its high cellulosic content, represented renewable source capable of being converted into essential platform chemicals like 5-hydroxymethylfurfural, levulinic acid, formic acid, and furfural. Currently, conversion of fructose to 5-HMF was achievable through various acid homogeneous catalysts. Although these catalysts yield higher outputs, they might pose challenges in recycling and corrosion issues. This thesis's novel approach involved preparing heterogeneous catalysts through pyrolysis and hydrothermal treatment of watermelon rind to create watermelon rind biochar (WB). Subsequently, WB underwent functionalization using HCl, H2SO4, and H3PO4 at concentrations of 1.6, 3.2, and 4.8N, respectively, at temperatures of 150 °C. These treated WB …

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Carboxymethyl Cellulose As Artificial Solid/Electrolyte Interphases And Separator For Zn-Based Battery, Phonnapha Tangthuam Jan 2023

Carboxymethyl Cellulose As Artificial Solid/Electrolyte Interphases And Separator For Zn-Based Battery, Phonnapha Tangthuam

Chulalongkorn University Theses and Dissertations (Chula ETD)

As the quest for robust large-scale energy storage systems (EESs) intensifies, aqueous rechargeable zinc-based batteries are gaining traction for grid-scale applications due to their high theoretical capacity and safety. Despite this, their practical application is compromised by several zinc anode issues, including hydrogen evolution, corrosion, dendritic growth, and passivation. An artificial solid electrolyte interphase (ASEI) using polyelectrolytes, such as carboxymethyl cellulose (CMC), is emerging as a solution, offering economic and environmental advantages. CMC's structure, enriched with carboxyl groups, allows for the refined management of zinc ion distribution at the electrode surface, promising enhanced surface stability. This study delves into CMC's …

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A Comparative Study Of Sustainable Aviation Fuel Production From Hydroprocessing Process Between Hydrogen Recovery Unit From Steam Reforming And Hydrogen Generation Unit From Biomass Gasification, Praeva Pongsripipat Jan 2023

A Comparative Study Of Sustainable Aviation Fuel Production From Hydroprocessing Process Between Hydrogen Recovery Unit From Steam Reforming And Hydrogen Generation Unit From Biomass Gasification, Praeva Pongsripipat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Sustainable aviation fuel (SAF) can be generated using various processes. Among the well-established approaches, one that stands out is the hydrotreating of esters and fatty acids (HEFA). However, the HEFA process requires a source of hydrogen for the hydroprocessing reactions. Hydrogen is often considered as an expensive component, and its cost can have a significant impact on the overall economic viability of renewable aviation fuel production. In this work, the SAF process is developed using Aspen Plus simulation. There are 2 scenarios to be considered. Scenario 1 involves a plant in which the hydrotreating of palm oil is performed to …

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Effect Of Dispersion Of Carbon Nanotubes On Electrical Conductivity And Compressive Strength Of Cnt/Cement Composite, Rittikiat Wandaw Jan 2023

Effect Of Dispersion Of Carbon Nanotubes On Electrical Conductivity And Compressive Strength Of Cnt/Cement Composite, Rittikiat Wandaw

Chulalongkorn University Theses and Dissertations (Chula ETD)

Carbon nanotubes (CNTs) are promising nanomaterials due to their exceptional properties, including high electrical, mechanical, and stability characteristics. These advantageous features position CNTs as suitable candidates for diverse applications, particularly in additive formulations designed to enhance overall performance. One notable application is their use in cement composites to improve mechanical and electrical properties. However, the hydrophobic property of CNTs presents challenges for dispersion within the hydrophilic cement matrix. Consequently, methods have been developed to aid CNT dispersion in both water and cement matrices. In this thesis, Triton X-100 employed as a surfactant, was used to disperse CNTs in water using …

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