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Articles 5221 - 5250 of 16774

Full-Text Articles in Materials Science and Engineering

Synthesis And Optical Properties Of Forsterite Ceramic Pigments Using Mirror Wastes As A Flux, Niti Yongvanich, Natchaya Lithira, Nitchakarn Nuniead, Wanchalerm Chauyarsa Jan 2021

Synthesis And Optical Properties Of Forsterite Ceramic Pigments Using Mirror Wastes As A Flux, Niti Yongvanich, Natchaya Lithira, Nitchakarn Nuniead, Wanchalerm Chauyarsa

Journal of Metals, Materials and Minerals

Cobalt-doped forsterite ceramic pigments based on the formula (Mg2-2xCo2x)SiO4 (x = 0, 0.05, 0.1, 0.2) were synthesized using mirror wastes as a flux. Addition of this flux enhanced forsterite phase formation at lower temperature by as much as 200℃. The resulting pigment particles were in a micron range which is suitable for use in a ceramic glaze. The host structure (Mg2SiO4) could accommodate cobalt cations up to 20 at%. Investigation on the chemical distribution revealed that no chemical species from the flux reacted with pigment grains. Optical properties were examined by UV-vis spectroscopy and colorimetry. Technical performance of the obtained …

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Deformation Manifold Learning Model For Multi Walled Carbon Nanotubes, Shashank S. Pathrudkar Jan 2021

Deformation Manifold Learning Model For Multi Walled Carbon Nanotubes, Shashank S. Pathrudkar

Dissertations, Master's Theses and Master's Reports

Two-Dimensional (2D) materials are being studied widely by researchers due to their superior material properties over the bulk materials. Since the isolation of graphene in 2004, graphene has gained popularity amongst the 2D materials community. Graphene when rolled into sheets form Carbon Nanotubes (CNTs) which possess excellent mechanical and electrical properties. Concentric stacks of CNTs yield Multi-walled Carbon Nanotubes (MWCNTs) which are superior to CNTs in certain aspects. It has been well established that the deformation of CNTs and MWCNTs change their mechanical and electrical properties significantly. This has opened doors for CNTs into numerous applications and also piqued the …

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Modeling And Optimization Of Process Parameters In Face Milling Of Ti6al4v Alloy Using Taguchi And Grey Relational Analysis, Al Mazedur Rahman, S M Abdur Rob, Anil K. Srivastava Jan 2021

Modeling And Optimization Of Process Parameters In Face Milling Of Ti6al4v Alloy Using Taguchi And Grey Relational Analysis, Al Mazedur Rahman, S M Abdur Rob, Anil K. Srivastava

Manufacturing & Industrial Engineering Faculty Publications

Titanium alloys are extensively used in aerospace, missiles, rockets, naval ships, automotive, medical devices, and even the consumer electronics industry where a high strength to density ratio, lightweight, high corrosion resistance, and resistance to high temperatures are important. The machining of these alloys has always been challenging for manufacturers. This article investigates the combined effect of radial depth, cutting speed and feed rate on cutting forces, tool life, and surface roughness during face milling of Ti6Al4V alloy. This study focuses on the significance of radial depth of cut on cutting force, tool life and surface roughness compared to that of …

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Novel Design And Facile Synthesis Of Functional Nanostructures For Energy And Environmental Application, Zhuojun Wang Jan 2021

Novel Design And Facile Synthesis Of Functional Nanostructures For Energy And Environmental Application, Zhuojun Wang

Wayne State University Theses

Environmental pollution and energy crisis are two of the major obstacles in the development of a more sustainable society. It is an interesting but technically challenging task to design novel methods for the facile and scalable synthesis of multifunctional materials for applications in both energy storage and environmental remediation. In this thesis, I tried to design and synthesize novel nanostructured materials for energy and environmental applications, achieved highly promising results. I developed a facile electrochemical approach to synthesize the zinc oxide with the zinc element for photocatalytic reactions. It demonstrated dramatically improved performances in degradation of organic pollutant in water, …

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Uv-Ozone Oxide Treatments For High-Efficiency Silicon Photovoltaic Devices, Munan Gao Jan 2021

Uv-Ozone Oxide Treatments For High-Efficiency Silicon Photovoltaic Devices, Munan Gao

Electronic Theses and Dissertations, 2020-2023

Fabrication of solar cells with higher efficiency, simpler processes and lower cost is largely perceived as the ultimate goal for photovoltaic research. To reach such a goal each step needs to be refined and optimized. In this dissertation, a UV-ozone treatment is proposed as a simple and versatile process that can be applied to multiple fabrication steps for improvement. The UV-ozone cleaning method provides comparable surface cleaning quality to more expensive and hazardous industrial standard RCA clean with less chemical used. A good passivation quality was achieved on both n-type and p-type silicon wafer by a silicon oxide/aluminum oxide passivation …

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Microstructural Development Of Inconel 625 Nickel-Based Superalloy As Function Of Laser Powder Bed Fusion Parameters, Sofia Nucci Jan 2021

Microstructural Development Of Inconel 625 Nickel-Based Superalloy As Function Of Laser Powder Bed Fusion Parameters, Sofia Nucci

Electronic Theses and Dissertations, 2020-2023

Additive manufacturing (AM) allows fabrication of complex components with features that are impractical or impossible to achieve through conventional methods. Selective laser melting (SLM) powder bed fusion AM technology was selected for this study on Inconel 625, a widely utilized high-temperature alloy that is hard to machine. The present work investigates impact of laser power and scanning speed variations on the resulting characteristics of fabricated IN625 samples. Gas atomized metallic alloy powders were acquired and analyzed through laser diffraction to verify acceptable size distribution. Cubic samples were built with a range of laser scan speeds in 200 mm/s intervals for …

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Investigation Of Cation Exchange Behaviors Of FaXMa1-XPbl3 Films Using Dynamic Spin Coating, Hyang Mi Yu, Byeong Geun Jeong, Dae Young Park, Seong Chu Lim, Gon Namkoong, Mun Seok Jeong Jan 2021

Investigation Of Cation Exchange Behaviors Of FaXMa1-XPbl3 Films Using Dynamic Spin Coating, Hyang Mi Yu, Byeong Geun Jeong, Dae Young Park, Seong Chu Lim, Gon Namkoong, Mun Seok Jeong

Applied Research Center Publications

In this study, we fabricated and characterized uniform multi-cation perovskite FAxMA1−xPbI3 films. We used the dynamic spin-coating method to control the cation ratio of the film by gradually increasing the FA+, which replaced the MA+ in the films. When the FA+ concentration was lower than xFA ~0.415 in the films, the stability of the multi-cation perovskite improved. Above this concentration, the film exhibited δ-phase FAPbI3 in the FAxMA1−xPbI3 films. The formation of δ-phase FAPbI3 disturbed the homogeneity of the photoluminescence spatial distribution and suppressed the absorption spectral bandwidth …

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Detection Of Subsurface, Nanometer-Scale Crystallographic Defects By Nonlinear Light Scattering And Localization, Farbod Shafiei, Tommaso Orzali, Alexey Vert, Mohammad-Ali Miri, Pui Yee Hung, Man Hoi Wong, Andrea Alù, Gennadi Bersuker, Michael C. Downer Jan 2021

Detection Of Subsurface, Nanometer-Scale Crystallographic Defects By Nonlinear Light Scattering And Localization, Farbod Shafiei, Tommaso Orzali, Alexey Vert, Mohammad-Ali Miri, Pui Yee Hung, Man Hoi Wong, Andrea Alù, Gennadi Bersuker, Michael C. Downer

Publications and Research

Heteroepitaxial crystalline films underlie many electronic and optical technologies but are prone to forming defects at their heterointerfaces. Atomic-scale defects such as threading dislocations that propagate into a film impede the flow of charge carriers and light degrading electrical/optical performance of devices. Diagnosis of subsurface defects traditionally requires time-consuming invasive techniques such as cross-sectional transmission electron microscopy. Using III–V films grown on Si, noninvasive, bench-top diagnosis of subsurface defects have been demonstrated by optical second-harmonic scanning probe microscope. A high-contrast pattern is observed of subwavelength “hot spots” caused by scattering and localization of fundamental light by defect scattering sites. Size …

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การเตรียมบล็อกปูทางเท้าพรุนน้ำจากเศษเซรามิกโดยใช้เคลือบเซรามิกเป็นวัสดุเชื่อมประสาน, พิมพ์รัมภา กิติธรากุล Jan 2021

การเตรียมบล็อกปูทางเท้าพรุนน้ำจากเศษเซรามิกโดยใช้เคลือบเซรามิกเป็นวัสดุเชื่อมประสาน, พิมพ์รัมภา กิติธรากุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัญหาน้ำท่วมขังหลังจากที่เกิดฝนตกหนัก มักเป็นปัญหาใหญ่สำหรับพื้นที่ในเขตเมืองหลวง ซึ่งส่งผลกระทบโดยตรงกับผู้คนที่สัญจรบนท้องถนน การนำบล็อกพรุนที่มีความสามารถในการระบายน้ำได้มาใช้ทำเป็นพื้นสำหรับทางเดินสามารถแก้ไขปัญหาดังกล่าวได้ โดยทั่วไปแล้วบล็อกพรุนที่มีความสามารถในการระบายน้ำที่สูงมักจะทำให้ค่าความแข็งแรงต่ำ เนื่องจากมีรูพรุนอยู่ในโครงสร้างของชิ้นงานมาก ดังนั้นในงานวิจัยนี้จึงสนใจนำเศษเซรามิกเนื้อสโตนแวร์ ที่แตกหักเสียหายจากอุตสาหกรรมเซรามิกประเภทเครื่องใช้บนโต๊ะอาหารที่ผ่านการบดและคัดขนาด 2 - 5 มิลลิเมตร มาใช้เป็นมวลรวมหยาบสำหรับการทำบล็อกพรุนและเลือกใช้เคลือบเซรามิกขาวทึบมาเป็นวัสดุเชื่อมประสาน โดยใช้กระบวนการขึ้นรูปด้วยมือในแม่พิมพ์ และได้ศึกษาปัจจัยที่ส่งผลต่อสมบัติทางกายภาพของบล็อกพรุน พบว่ามีปัจจัยหลัก 4 ที่ส่งผลต่อสมบัติทางกายภาพของบล็อกพรุน ได้แก่ อุณหภูมิที่ใช้ในการเผาบล็อกพรุน อัตราส่วนระหว่างมวลรวมและวัสดุเชื่อมประสาน ขนาดของเศษเซรามิกที่ใช้เป็นมวลรวม และความเข้มข้นของเคลือบที่ใช้เป็นวัสดุเชื่อมประสาน นอกจากนี้ยังได้หาเงื่อนไขที่เหมาะสมต่อการขึ้นรูปบล็อกพรุนที่ให้อัตราการไหลซึมผ่านของน้ำและค่าความแข็งแรงที่เหมาะสม ซึ่งพบว่าบล็อกพรุนปูทางเท้าที่ประกอบด้วยเศษเซรามิกขนาด 2 – 5 มิลลิเมตร ปริมาณร้อยละ 80 โดยน้ำหนัก วัสดุเชื่อมประสานปริมาณร้อยละ 20 โดยในวัสดุเชื่อมประสานประกอบด้วยสัดส่วนผงเคลือบแห้งต่อน้ำ ร้อยละ 71.43 : 28.57 โดยน้ำหนัก และเผาที่อุณหภูมิ 1200 °C ซึ่งให้ค่าความแข็งแรงต่อแรงอัดที่ 24.57 MPa ความหนาแน่น 1.64 g/cm3 ค่าความพรุนตัว 30.43% และอัตราการไหลซึมผ่านของน้ำ 897.74 L/m2·min

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การผลิตฟิล์มดูดกลืนยูวีจากลิกโนซัลโฟเนตที่สังเคราะห์จากลิกนินในน้ำดำของการผลิตเยื่อชานอ้อยด้วยวิธีโซดา, ชลธิดา บุญตามส่ง Jan 2021

การผลิตฟิล์มดูดกลืนยูวีจากลิกโนซัลโฟเนตที่สังเคราะห์จากลิกนินในน้ำดำของการผลิตเยื่อชานอ้อยด้วยวิธีโซดา, ชลธิดา บุญตามส่ง

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในขั้นตอนการผลิตเยื่อกระดาษด้วยวิธีโซดาจะเกิดของเสียขึ้นเรียกว่า น้ำดำ ซึ่งมีลิกนินเป็นองค์ประกอบหลัก ลิกนินที่ได้นั้นสามารถนำไปสังเคราะห์เป็นลิกโนซัลโฟเนตซึ่งมีสมบัติเป็นสารอิมัลซิไฟเออร์และสามารถดูดกลืนรังสียูวี งานวิจัยนี้จึงได้ศึกษาการผลิตแผ่นฟิล์มดูดกลืนยูวีจากลิกโนซัลโฟเนตที่สังเคราะห์จากลิกนินในน้ำดำที่ได้จากการผลิตเยื่อชานอ้อยด้วยวิธีโซดา โดยเริ่มจากการศึกษาผลของความเข้มข้นของโซเดียมไฮดรอกไซด์ในกระบวนการผลิตเยื่อต่อการสกัดลิกนิน โดยทดลองใช้ความเข้มข้นของโซเดียมไฮดรอกไซด์ในการต้มเยื่อที่ร้อยละ 12, 14, 16 และ 18 ของน้ำหนักเยื่อแห้ง เนื่องจากลิกนินมีความสามารถในการละลายที่ต่ำในตัวกลางที่เป็นกรด จึงได้ทำการแยกลิกนินโดยวิธีการเติมกรดซัลฟิวริกในน้ำดำ พบว่าลิกนินที่ได้จากความเข้มข้นของโซเดียมไฮดรอกไซด์แตกต่างกันจะมีโครงสร้างเหมือนกันและเมื่อเพิ่มความเข้มข้นของโซเดียมไฮดรอกไซด์ในการต้มเยื่อจะได้ปริมาณลิกนินที่เพิ่มขึ้น การใช้ความเข้มข้นของโซเดียมไฮดรอกไซด์ที่ร้อยละ 12 ให้อัตราส่วนลิกนินต่อสารเคมีสูงที่สุดจึงได้เลือกลิกนินที่ได้จากภาวะนี้ไปตกตะกอนและนำไปสังเคราะห์เป็นลิกโนซัลโฟเนตผ่านปฏิกิริยาเมทิลซัลโฟเนชันโดยใช้ฟอร์มาลดีไฮด์และโซเดียมซัลไฟต์ พบว่าลิกโนซัลโฟเนตที่สังเคราะห์ได้ภายในงานวิจัยมีโครงสร้างคล้ายกับลิกโนซัลโฟเนตเชิงการค้า จากนั้นได้นำลิกโนซัลโฟเนตที่สังเคราะห์ได้ผสมกับพอลิเมอร์ที่สามารถย่อยสลายได้ เพื่อศึกษาสมบัติต่างๆ ของฟิล์ม ลักษณะของฟิล์มที่ได้มีความเป็นเนื้อเดียวกันแสดงถึงความเข้ากันได้ระหว่างลิกโนซัลโฟเนตและพอลิเมอร์ ฟิล์มที่ผสมลิกโนซัลโฟเนตสามารถดูดกลืนรังสีในช่วงยูวีได้ทั้งหมด เนื่องจากมีหมู่โครโมฟอร์ซึ่งมีความสามารถในการดูดกลืนยูวีอยู่ในโครงสร้าง ฟิล์มที่ผสมลิกโนซัลโฟเนตนั้นผิวหน้าของฟิล์มจะมีความชอบน้ำมากขึ้น การเติมลิกโนซัลโฟเนตที่สังเคราะห์ในงานวิจัยสามารถปรับปรุงสมบัติเชิงกลของฟิล์มได้โดยจะไปเพิ่มความต้านทานแรงดึงของฟิล์มและค่ายังมอดูลัส จากการศึกษาสภาวะที่เหมาะสมโดยวิธีพื้นที่ผิวตอบสนองพบว่าความเข้มข้นที่เหมาะสมต่อการผลิตฟิล์มที่ต้านทานยูวีได้ร้อยละ 97 พบว่าต้องผสมลิกโนซัลโฟเนตที่ความเข้มข้นร้อยละ 0.29 โดยน้ำหนักต่อปริมาตร ปริมาณพอลิไวนิลแอลกอฮอล์ที่ความเข้มข้นร้อยละ 0.89 โดยน้ำหนักต่อปริมาตร และกลีเซอรอลร้อยละ 0.89 โดยปริมาตร

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Dual-Functional Phosphorene Nanocomposite Membranes For The Treatment Of Perfluorinated Water: An Investigation Of Perfluorooctanoic Acid Removal Via Filtration Combined With Ultraviolet Irradiation Or Oxygenation, Joyner Eke, Lillian Banks, M. Abdul Mottaleb, Andrew J. Morris, Olga V. Tsyusko, Isabel C. Escobar Jan 2021

Dual-Functional Phosphorene Nanocomposite Membranes For The Treatment Of Perfluorinated Water: An Investigation Of Perfluorooctanoic Acid Removal Via Filtration Combined With Ultraviolet Irradiation Or Oxygenation, Joyner Eke, Lillian Banks, M. Abdul Mottaleb, Andrew J. Morris, Olga V. Tsyusko, Isabel C. Escobar

Internal Medicine Faculty Publications

Nanomaterials with tunable properties show promise because of their size-dependent electronic structure and controllable physical properties. The purpose of this research was to develop and validate environmentally safe nanomaterial-based approach for treatment of drinking water including removal and degradation of per- and polyfluorinated chemicals (PFAS). PFAS are surfactant chemicals with broad uses that are now recognized as contaminants with a significant risk to human health. They are commonly used in household and industrial products. They are extremely persistent in the environment because they possess both hydrophobic fluorine-saturated carbon chains and hydrophilic functional groups, along with being oleophobic. Traditional drinking water …

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Data-Driven Discovery Of Material States In Composites Under Fatigue Loads, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider Jan 2021

Data-Driven Discovery Of Material States In Composites Under Fatigue Loads, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

Our community has a widespread knowledge on the damage tolerance and durability of the composites, developed over the past few decades by various experimental and computational efforts. Several methods have been used to understand the damage behavior and henceforth predict the material states such as residual strength (damage tolerance) and life (durability) of these material systems. Electrochemical Impedance Spectroscopy (EIS) and Broadband Dielectric Spectroscopy (BbDS) are such methods, which have been proven to identify the damage states in composites. Our previous work using BbDS method has proven to serve as precursor to identify the damage levels, indicating the beginning of …

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Ordinary Differential Equations With Machine Learning For Prediction Of Smart Composite Fracture Toughness, Relebohile George Qhobosheane, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan Jan 2021

Ordinary Differential Equations With Machine Learning For Prediction Of Smart Composite Fracture Toughness, Relebohile George Qhobosheane, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

This work in on the development of an ordinary differential equation (ODE) model coupled with statistical methods for the prediction of fracture toughness of a magnetostrictive, piezoelectric smart self-sensing Fiber Reinforced Polymer (FRP) composite. The smart composite with sensing properties encompasses Terfenol-D alloy nanoparticles and Single Walled Carbon NanoTubes (SWCNT). To explore various configurations the of nanoparticle constituents’ effect on fracture toughness within the FRP composite, the ODE model developed within a finite element analysis (FEA) environment is considered to attain fracture observations across the solution space. The acquired FEA data is then used to feed the machine-learning (ML) algorithms …

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Effects Of Surface Characteristics On Mechanical And Dielectric Properties Of Adhesively Bonded Carbon Fiber Composites, Minhazur Rahman, Gayathri Kola, Monjur Morshed Rabby, Muthu Ram Prabhu Elenchezhian, Relebohile George Qhobosheane, Vamsee Vadlamudi Jan 2021

Effects Of Surface Characteristics On Mechanical And Dielectric Properties Of Adhesively Bonded Carbon Fiber Composites, Minhazur Rahman, Gayathri Kola, Monjur Morshed Rabby, Muthu Ram Prabhu Elenchezhian, Relebohile George Qhobosheane, Vamsee Vadlamudi

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

The rapid rise of fiber reinforced composite usage in aircraft, spacecraft and automobile industries made the proper comprehension of repair and joining of these materials a crucial aspect. Adhesive bonding is one of the most advantageous and desirable joining and repair technique for fiber reinforced composites. However, the heterogeneity of fiber reinforced composites and the complex interfacial nature of the adhesive bonds, makes most non-destructive evaluation and assessment techniques ineffective to assess the state of the bond. Different manufacturing and surface preparation techniques impart different surface characteristics to the adherends, hence proper understanding of the state of bonds is dependent …

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Tailoring Texture, Microstructure, And Shape Memory Behavior Of Niti Alloys Fabricated By L-Pbf-Am, Sayed Ehsan Saghaian N.E. Jan 2021

Tailoring Texture, Microstructure, And Shape Memory Behavior Of Niti Alloys Fabricated By L-Pbf-Am, Sayed Ehsan Saghaian N.E.

Theses and Dissertations--Mechanical and Aerospace Engineering

Laser Powder Bed Fusion (L-PBF) is one of the most promising Additive Manufacturing (AM) methods to fabricate near net-shape metallic materials for a wide range of applications such as patient-specific medical devices, functionally graded materials, and complex structures. NiTi shape memory alloys (SMAs) are of great interest due to a combination of unique features, such as superelasticity, shape memory effect, high ductility, work output, corrosion resistance, and biocompatibility that could be employed in many applications in automotive, aerospace, and biomedical industries. Due to the difficulties with traditional machining and forming of NiTi components, the ability to fabricate complex parts, tailor …

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Viscoelasticity Of Ptfe-Based Face Seals, Bo Tan Jan 2021

Viscoelasticity Of Ptfe-Based Face Seals, Bo Tan

Theses and Dissertations--Mechanical and Aerospace Engineering

PTFE-based materials are widely used in areas of tribology, particularly in seal and bearing applications because of their outstanding self-lubricating properties. Often in dynamic seal applications there is a need for ultra-low mechanical friction loss between the sealing surfaces. Due to its extremely low friction coefficient, there is interest in employing Polytetrafluoroethylene (PTFE) materials in such applications. One challenging aspect of employing PTFE is that these materials are viscoelastic and plastic. This dissertation concentrates on the modeling of viscoelastic material response when used as mechanical face seals with a focus on PTFE-based materials. First, the viscoelastic characteristics are measured through …

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Thermomechanical Mechanisms That Cause Adhesion Of Aluminum High Pressure Die Castings To The Die, Alex Monroe Jan 2021

Thermomechanical Mechanisms That Cause Adhesion Of Aluminum High Pressure Die Castings To The Die, Alex Monroe

Dissertations, Master's Theses and Master's Reports

In high pressure die casting (HPDC) of aluminum, cast material adhering to die is a significant defect. Adhesion occurs in two primary ways. The casting may stick preventing its removal from the die. Aluminum can also adhere to the die and buildup in local areas on the die surface with additional casting cycles. This second form of adhesion is called soldering. Lubricant is the best technology to control all forms of adhesion, but it comes at the cost of casting porosity, blisters, reduced die life, and increased die casting machine wear. New strategies to prevent adhesion are desired to eliminate …

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Atomistic Monte Carlo Simulation Study Of Phase Transitions In Metal Alloys, Xiaoxu Guo Jan 2021

Atomistic Monte Carlo Simulation Study Of Phase Transitions In Metal Alloys, Xiaoxu Guo

Dissertations, Master's Theses and Master's Reports

The atomic-scale Monte Carlo simulation study focuses on the intrinsic behaviors of a defect-free crystal that undergoes a cubic-to-tetragonal martensitic transformation. The quasi-spin variable associated with the lattice sites characterizes the local unit cells of the orientation variants of the ground-state martensite phase, which interact with each other through long-range elastic interactions. It is shown that the diffuse scattering in the premartensitic austenite state results from the spatial correlation of the atomic-scale heterogeneous lattice displacements and manifests the displacement short-range ordering. The effects of temperature, elastic anisotropy, and shear modulus softening on the diffuse scattering and displacement short-range ordering are …

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Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin Jan 2021

Establishing Independent Tunability Of The Mechanical And Transport Properties Of Polymer Gels, Lucas Rankin

Master’s Theses

Polymer gels can be used in the fabrication of materials for filtering liquid and gaseous media, solid-state electrolytes, and transdermal medical patches. This diverse range of applications primarily relies on the transport and mechanical properties of polymer gels. Both sets of properties have shown excellent tunability, but typically in a coupled fashion. Establishing the independent tunability of the transport and mechanical properties of polymer gels (using simple, cost-effective methods) is paramount if polymer gels are to be used to their full potential. Specifically, block copolymer gels self-assemble into organized nanoscale networks within the gel solvent, which allows for facile control …

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Synthesis And Catalytic Properties Of Metal-Organic Frameworks Mimicking Carbonic Anhydrase, Longji Li Jan 2021

Synthesis And Catalytic Properties Of Metal-Organic Frameworks Mimicking Carbonic Anhydrase, Longji Li

Mahurin Honors College Capstone Experience/Thesis Projects

The natural enzyme carbonic anhydrase has gained attention in recent years for its ability to catalyze the interconversion of aqueous carbon dioxide (CO2) and bicarbonate. However, it lacks the efficiency to qualify practical usage on a large scale due to its inherent deficiency and fragile nature. On the other hand, its active center can be used as an ideal model for the design of novel catalytic materials targeting carbon dioxide capture and sequestration. This study focused on the synthesis of a zinc-based metal-organic framework (Zn-MOF-1) mimicking the carbonic anhydrase using the solvothermal method. Important properties such as catalytic …

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On The Mechanical Properties Of Al/Cu-Grid/Al Intermetallic Composite, Hamza Essoussi, Said Ettaqi Jan 2021

On The Mechanical Properties Of Al/Cu-Grid/Al Intermetallic Composite, Hamza Essoussi, Said Ettaqi

Journal of Metals, Materials and Minerals

The present paper deals with the experimental investigation of new process combining static compression with high temperature as a simple way to prepare new Al/Cu-grid/Al metallic composite (MC) that consists of Aluminum matrix and Copper grid acting as ductile reinforcement stacked between the Al sheets. At the stage of composite fabrication, two different thermal cycles were tested to highlight the effect of processing temperature on the layers’ adherence and the mechanical properties of the prepared composites. Consequently, the microstructural and mechanical results revealed that the compression at 630℃ for 30 min, then furnace cooled to 450℃ followed by air cooling …

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Thermal Behavior Of Solid Acids In The Rb3h(So4)2-Rbhso4 System Under Ambient Atmosphere, Chatr Panithipongwut Kowalski, Permpoon Chaijaroen, Farook Kaewniyom Jan 2021

Thermal Behavior Of Solid Acids In The Rb3h(So4)2-Rbhso4 System Under Ambient Atmosphere, Chatr Panithipongwut Kowalski, Permpoon Chaijaroen, Farook Kaewniyom

Journal of Metals, Materials and Minerals

The thermal behavior of solid acids in the Rb3H(SO4)2-RbHSO4 system under ambient atmosphere has been studied in comparison to the previously reported high-temperature behavior of the same system under humidified atmosphere. The findings showed that, under this level of humidity, the transition of RbHSO4, the transition of Rb5H3(SO4)4, and the disproportionation of Rb3H(SO4)2, occurred at the same temperatures as those under humidified atmosphere. However, the results from differential scanning calorimetry did not reveal the reaction temperature between Rb3H(SO4)2 and RbHSO4 due to the slow process. The dehydration temperatures of Rb5H3(SO4)4 were surprisingly similar between the systems under low and high …

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Graphene Enhanced Linear Low-Density Polyethylene Nanocomposites By Premixing And Melt Compounding, Wan Nazri Wan Busu, Ruey Shan Chen, Muhammad Jefri Mohd Yusof, Sahrim Ahmad Jan 2021

Graphene Enhanced Linear Low-Density Polyethylene Nanocomposites By Premixing And Melt Compounding, Wan Nazri Wan Busu, Ruey Shan Chen, Muhammad Jefri Mohd Yusof, Sahrim Ahmad

Journal of Metals, Materials and Minerals

In this study, linear low-density polyethylene/graphene nanoplatelets (LLDPE/GNPs) nanocomposites were prepared from conventional melt-mixing method and our new approach; two-step premix mixing technique. Indirect mixing technique (IDT) was employed to fabricate a premix of LLDPE/ GNPs in the ratio of 80:20 wt%. The effects of GNPs loadings and the processing method of nanocomposites on the mechanical strength, decomposition temperature, crystallinity, electrical impedance and morphology were investigated. Irrespective of processing methods, the prepared nanocomposites exhibited crystalline structure due to the presence of GNPs whilst the degradation temperature was recorded to be increased with GNPs loadings that signified improved thermal stability. The …

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Preparation Of Transparent Alumina Thin Films Deposited By Rf Magnetron Sputtering, Busarin Noikaew Noikaew, Laksana Wangmooklang, Saisamorn Niyomsoan, Siriporn Larpkiattaworn Jan 2021

Preparation Of Transparent Alumina Thin Films Deposited By Rf Magnetron Sputtering, Busarin Noikaew Noikaew, Laksana Wangmooklang, Saisamorn Niyomsoan, Siriporn Larpkiattaworn

Journal of Metals, Materials and Minerals

Alumina (Al2O3) thin films were prepared by RF magnetron sputtering technique using Al2O3 ceramic target. Effects of sputtering powers and oxygen gas mixtures were investigated and the optimized coating condition was applied on semi-precious gemstones. RF sputtering powers were varied to optimize the transparency of the films. Besides, the oxygen gas mixtures were also studied at the optimized sputtering power with a constant sputtering pressure. Optical and physical properties of the thin films were investigated using UV-Vis Spectrophotometer, FESEM, XRF, GIXRD, XRR including a microscratch tester. The Al2O3 films were highly transparent in the visible region in form of an …

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Extraction Of Cellulose Nanofibers From Empty Palm Fruit Bunches Via Mechanical Defibrillation, Zi-Qian Tan, Takaomi Kobayashi, Duangdao Aht-Ong Jan 2021

Extraction Of Cellulose Nanofibers From Empty Palm Fruit Bunches Via Mechanical Defibrillation, Zi-Qian Tan, Takaomi Kobayashi, Duangdao Aht-Ong

Journal of Metals, Materials and Minerals

In recent years, there has been an increasing interest in finding alternative material to replace fossil-oil based product due to the environmental concern. Lignocellulosic biomass has emerged as the promising candidate due to its low-cost and sustainability. The objective of this work was to prepare cellulose nanofibers (CNFs) from empty palm fruit bunches (EPFB), which are the waste originating from palm oil industry. Cellulose fibers were first extracted from EPFB by chemical treatment, followed by mechanical disintegration using high-pressure homogenization. Fiber concentration and defibrillation time during mechanical treatment were studied to investigate their effects on the properties of produced nanofibers. …

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The Effect Of Phosphogypsum On Stabilizing Clay Soil And Improving Its Properties For Use As Foundation Soil, Mai Yahya Maaitah, Mus'ab Ziad Banat Jan 2021

The Effect Of Phosphogypsum On Stabilizing Clay Soil And Improving Its Properties For Use As Foundation Soil, Mai Yahya Maaitah, Mus'ab Ziad Banat

Journal of Metals, Materials and Minerals

Expansive soil covers large areas in a variety of regions in Jordan which is insufficient to meet the engineering specifications in construction. Phosphogypsum is considered to be the main by-product material which comes from phosphate rock deposits that is available in Jordan. The main purpose of this research is to study the effects of stabilization by phosphogypsum on expansive soil properties. Three Jordanian regions were chosen to represent the expansive soils, Irbid, Madaba, and Abu-Nusire city. Soils were mixed with phosphogypsum at different percentages by dry weight of soil. Some of the representative laboratory tests for swell properties were conducted: …

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The Effect Of Artificial Defects On The Fatigue Characteristics Of Aisi 4340 Steel, Yakov B. Unigovski, Dmitry Fishman, Liat Fishman, Liron Shichman, Ofir Moshe, Roni Shneck, Emmanuel Gutman Jan 2021

The Effect Of Artificial Defects On The Fatigue Characteristics Of Aisi 4340 Steel, Yakov B. Unigovski, Dmitry Fishman, Liat Fishman, Liron Shichman, Ofir Moshe, Roni Shneck, Emmanuel Gutman

Journal of Metals, Materials and Minerals

This study examined the fatigue life (Nf) and fatigue limit (FL) of AISI 4340 steel in relation to surface roughness, artificial defects and shot peening. Artificial surface defects on fatigue specimens were obtained by electrical discharge machining (EDM) or by pre-corrosion in 3.5% NaCl and perchloric acid solutions, followed by a fatigue test. The presence of artificial defects of various sizes, taken into account by the area  parameter, led to a significant decrease in fatigue characteristics, while shot peening contributed to their noticeable improvement. Defects resulting from electrochemical corrosion had a much greater negative effect on fatigue …

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The Enhancement Of Ethanol Gas Sensors Response Based On Calcium And Zinc Co-Doped Lafeo3/Fe2o3 Thick Film Ceramics Utilizing Yarosite Minerals Extraction As Fe2o3 Precursor, Endi Suhendi, Zeany Luckyta Amanda, Muhamad Taufik Ulhakim, Andhy Setiawan, Dani Gustaman Syarif Jan 2021

The Enhancement Of Ethanol Gas Sensors Response Based On Calcium And Zinc Co-Doped Lafeo3/Fe2o3 Thick Film Ceramics Utilizing Yarosite Minerals Extraction As Fe2o3 Precursor, Endi Suhendi, Zeany Luckyta Amanda, Muhamad Taufik Ulhakim, Andhy Setiawan, Dani Gustaman Syarif

Journal of Metals, Materials and Minerals

A gas sensor is a renewed interest of research which has been developed to make a device that can be detected the harmful gases and applied in the several fields of industries. In this paper, we report the modified of gas sensor based thick film ceramic LaFeO3/Fe2O3 by added calcium and zinc co-doping prepared by screen-printed technique. In this work, yarosite mineral was utilized as Fe2O3 precursor. It aims to take the advantages of abundance natural resources in Indonesia to save a cost in gas sensor fabrication. Then, x-ray diffraction (XRD), scanning electron microscopy (SEM) and electrical properties characterization were …

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Wollastonite And Talc Reinforced Polypropylene Hybrid Composites: Mechanical, Morphological And Thermal Properties, Naruedee Putfak, Amnouy Larpkasemsuk Jan 2021

Wollastonite And Talc Reinforced Polypropylene Hybrid Composites: Mechanical, Morphological And Thermal Properties, Naruedee Putfak, Amnouy Larpkasemsuk

Journal of Metals, Materials and Minerals

This study focused on evaluating the mechanical, thermal, and morphological properties of polypropylene (PP) hybrid composites containing two different inorganic mineral fillers, namely wollastonite (WO) and talc. The composites were prepared by melt mixing process using a twin screw extruder and an injection molding machine. All composites contained a constant filler loading at 20 wt% with varying WO/talc weight ratios (20/0, 15/5, 10/10, 5/15, and 0/20). Melt flow index (MFI), mechanical properties (impact strength and tensile properties), heat distortion temperature (HDT) fractured surface morphology, and thermal behaviors of the resulting composites were investigated. The results revealed an enhancement in the …

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Effect Of Nitrocarburizing And Argon Admixing On Low Carbon Steel For Component Facility In Radiometallurgical Installation, Erwan Hermawan, Suprapto Suprapto, Usman Sudjadi, Siti Shaleha, Maman Kartaman Ajiriyanto Jan 2021

Effect Of Nitrocarburizing And Argon Admixing On Low Carbon Steel For Component Facility In Radiometallurgical Installation, Erwan Hermawan, Suprapto Suprapto, Usman Sudjadi, Siti Shaleha, Maman Kartaman Ajiriyanto

Journal of Metals, Materials and Minerals

Steel is an important component in the industrialized world with rising growth in world consumption. Steel has wide applications due to its high strength, durability, and cost-effectiveness. This has applications in the nuclear power plant. In Indonesian nuclear industry, low carbon steel is used not only for the fabrication of reactor components but also for the radiometallurgical facilities. However, to avoid the risk of premature failure and enhance the longevity of the components in the service condition, surface modification for the improvement of hardness has been realized. Amongst several methods, surface hardening by following nitrocarburizing has been found to be …

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