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Engineering Science and Materials Commons™
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- 2.25Cr-1Mo steel; Inconel 625; Hot-wire TIG; Cladding; Corrosion behaviors (1)
- 2D composite; MXene; Dielectrics; Structural; Morphology (1)
- 316L stainless steel; Plastic deformation; Surface relief; Contact angle; Surface free energy (1)
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Articles 361 - 390 of 502
Full-Text Articles in Engineering Science and Materials
The Influence Of Different Crystal Modifiers On Ultra-Low Embodied Energy Curing Fiber-Reinforced Cement Composites, Passakorn Sonprasarn, Wichit Prakaypan, Sureerat Polsilapa, Nuntaporn Kongkajun, Edward A. Laitila, Nutthita Chuankrerkkul, Parinya Chakartnarodom
The Influence Of Different Crystal Modifiers On Ultra-Low Embodied Energy Curing Fiber-Reinforced Cement Composites, Passakorn Sonprasarn, Wichit Prakaypan, Sureerat Polsilapa, Nuntaporn Kongkajun, Edward A. Laitila, Nutthita Chuankrerkkul, Parinya Chakartnarodom
Journal of Metals, Materials and Minerals
Fiber-reinforced cement composites (FRCC) are widely used in the construction of houses and commercial buildings in many countries such as the United States, the United Kingdom, the European countries, and the Asian countries such as China, India, and Thailand. Conventionally, the FRCC is manufactured from Portland cement, silica sand, and cellulose fiber using the so-called autoclaved curing under a designate hydrothermal condition to accelerate the hydration reaction resulting in superior properties. However, the autoclave-curing process needs a huge investment and generates highly environmental impact specially greenhouse gases due to its heavy energy consumption. Hence, this research aims to develop the …
Sequential Injection Analysis For Mercury Ion With Modified Screen – Printed Carbon Electrode, Eakkasit Punrat, Naphat Piyasart, Chalinee Auanphui, Rutanachai Thaipratum, Shoji Motomizu, Wanida Wonsawat
Sequential Injection Analysis For Mercury Ion With Modified Screen – Printed Carbon Electrode, Eakkasit Punrat, Naphat Piyasart, Chalinee Auanphui, Rutanachai Thaipratum, Shoji Motomizu, Wanida Wonsawat
Journal of Metals, Materials and Minerals
In this study, we developed a simple high-throughput and cost-effective method for monitoring toxic metal ion in an environmental aqueous sample. Mercury ion determination with Sequential Injection Analysis system (SIAs) coupled with the electrochemical detection on the modified screen-printed carbon working electrode (SPCE) is an alternative green analysis of mercury ion. The gold film was used as the modified material for improved mercury ion analysis in the automated system without memory effect on the electrode. Mercury oxidation signal was found at the potential of 0.7 V in 0.1 M HNO3 and 1.0 M HCl with the concentration low to 0.25 …
Effect Of A-Site Modification On Structural And Microwave Dielectric Properties Of Calcium Titanate, Shailendra Rajput, Sunita Keshri
Effect Of A-Site Modification On Structural And Microwave Dielectric Properties Of Calcium Titanate, Shailendra Rajput, Sunita Keshri
Journal of Metals, Materials and Minerals
This article presents studies on characteristics properties of CaTiO3, Ca0.8Sr0.2TiO3, and Ca0.6La0.8/3TiO3 ceramics. These ceramics were synthesized using the solid-state reaction process. Structural examination revealed that the grown ceramics have an orthorhombic structure with the Pbnm space group. The random distribution of particle size was shown through morphological investigation. Apparent density of developed ceramics was determined using the Archimedes technique and found to be ˂ 90%. The microwave dielectric properties of grown ceramics are compared on the basis of ionic polarizability. It is observed that partial replacement of Ca-ions by Sr-ions provides a high permittivity value (er = 168.93), higher …
Hole Transport Layers In Organic Solar Cells: A Review, Riva Alkarsifi, Jörg Ackermann, Olivier Margeat
Hole Transport Layers In Organic Solar Cells: A Review, Riva Alkarsifi, Jörg Ackermann, Olivier Margeat
Journal of Metals, Materials and Minerals
Thanks to huge research efforts, organic solar cells have become serious candidates in the field of renewable energy sources, with reported power conversion efficiencies above 19% and operating lifetime surpassing decades. In the thin film stack composing the organic solar cell, the transport layers at interfaces play a key role, as important as the photoactive material itself. Both electron (ETL) and hole (HTL) transport layers are indeed directly involved in the efficiency and stability of the devices, due to the very specific properties required for these interfaces. Focusing on the HTL interface, a large number of materials has been used …
Research Progress Of Novel Zirconium Alloys With High Strength And Toughness, Na Zhang, Chaoqun Xia, Jiaqian Qin, Qiang Li, Xinyu Zhang, Riping Liu
Research Progress Of Novel Zirconium Alloys With High Strength And Toughness, Na Zhang, Chaoqun Xia, Jiaqian Qin, Qiang Li, Xinyu Zhang, Riping Liu
Journal of Metals, Materials and Minerals
Atoms of zirconium (Zr) are often known as "first metals of the atomic age". Because of its low cross section for thermal neutron absorption, excellent corrosion resistance, and good mechanical and processing properties, it is extensively used in the nuclear industry. As the properties requirements of materials in chemical, medical and aerospace fields turn out to be higher, the application of Zr alloys in these non-nuclear fields has become more and more widespread due to their excellent properties. In addition to having a high melting point, Zr alloys also have a high specific strength and low thermal expansion coefficient. Therefore, …
Rice Husk Ash Utilization, Composition And Properties: A Brief Review, Vignesh Nayak Ullal, Shivaramu H. T., Aveen K. P.
Rice Husk Ash Utilization, Composition And Properties: A Brief Review, Vignesh Nayak Ullal, Shivaramu H. T., Aveen K. P.
Journal of Metals, Materials and Minerals
Asian countries rely massively on rice to feed and sustain its massive population. For long the staple food has provided nourishment to the masses and the classes. Rice is grown in large quantities in Asian countries. A by-product of its cultivation is its husk. The husk of the rice grain is mainly utilized as a fuel for the boilers in the rice mills. The uncontrolled burnt rice husk referred to as rice husk ash consists majorly of silica. silica is used in a wide variety of commercial and industrial applications. Use of rice husk ash in various products serves to …
Extraction Of Lutein Dye From Tagetes Erecta Garland Waste For Green Dyeing Of Hemp Fabric Using Response Surface Methodology, Pisutsaran Chitichotpanya, Nattaya Vuthiganond, Thitirat Inprasit, Benjamas Klaykruayat, Seranee Srisuk
Extraction Of Lutein Dye From Tagetes Erecta Garland Waste For Green Dyeing Of Hemp Fabric Using Response Surface Methodology, Pisutsaran Chitichotpanya, Nattaya Vuthiganond, Thitirat Inprasit, Benjamas Klaykruayat, Seranee Srisuk
Journal of Metals, Materials and Minerals
Large quantities of discarded flowers from religious observances are left at temples and other places of worship, causing global disposal and environmental issues. Recycling and transforming such organic waste into value-added products is one of the most effective and beneficial solutions to the problem. The main goal of this study is to convert the most abundant temple wastes of marigold (Tagetes erecta) flowers into an eco-friendly dyestuff for the textile industry. Our study assessed the suitability of dye extract from garland waste for dyeing hemp fabric and valuated indicators including color strength (K/S) and fastness properties using tannic …
Development Of Fexoy Particle Onto Bacterial Cellulose Network By Forced Hydrolysis And Its Electrical Conductivity, Prompong Khamwongsa, Poramed Wongjom, Andi Magattang Gafur Muchlisc, Chun Che Lin, Seranee Srisuk, Sarute Ummartyotin
Development Of Fexoy Particle Onto Bacterial Cellulose Network By Forced Hydrolysis And Its Electrical Conductivity, Prompong Khamwongsa, Poramed Wongjom, Andi Magattang Gafur Muchlisc, Chun Che Lin, Seranee Srisuk, Sarute Ummartyotin
Journal of Metals, Materials and Minerals
FexOy particle and bacterial cellulose composite sheet was successfully prepared by forced hydrolysis. The presence of Fe3+ ions in bacterial cellulose suspension significantly provided the positive charge due to electrostatic force as reported by Zeta potential. With the pH of 12 of bacterial cellulose suspension, particle was nucleated between bacterial cellulose networks. Fourier transform infrared exhibited Fe-O stretching. X-ray diffraction reported that the mixture of Fe2O3 and Fe3O4 was existed onto bacterial cellulose composite. Scanning electron microscope reported that FexOy particle was randomly distributed in bacterial cellulose network. Intensity of Fe was qualitatively observed by energy dispersive analysis. With the …
Morphology And Electrochromic Property Of Chemical Bath Deposited Nio Films At Different Niso4 Concentration, Watcharaporn Thongjoon, Kamon Aiempanakit, Itsarapong Chuasontia, Chantana Aiempanakit
Morphology And Electrochromic Property Of Chemical Bath Deposited Nio Films At Different Niso4 Concentration, Watcharaporn Thongjoon, Kamon Aiempanakit, Itsarapong Chuasontia, Chantana Aiempanakit
Journal of Metals, Materials and Minerals
In this study, nickel oxide (NiO) films were prepared on indium tin oxide (ITO) glass by a chemical bath deposition (CBD) at different nickel sulfate (NiSO4) concentrations. The NiO films were verified for their structural properties with field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) while the optical properties were investigated using a spectrophotometer. Moreover, the NiO films were studied to assess their electrochemical properties by cyclic voltammetry in potassium hydroxide (KOH) electrolyte. The results showed that annealed NiO films exhibited the dominant crystal structure of the (111) plane. Meanwhile, the NiSO4 concentration controlled morphological structure between dense …
Optimized Parameter Of Dissimilar Joining Between Al6061-T6 And Height-Strength Steel With Friction Stir Spot Welding Process (Fssw), Anusak Silachai, Suriya Prasomthong
Optimized Parameter Of Dissimilar Joining Between Al6061-T6 And Height-Strength Steel With Friction Stir Spot Welding Process (Fssw), Anusak Silachai, Suriya Prasomthong
Journal of Metals, Materials and Minerals
High-strength steel and aluminum alloys are used to manufacture modern vehicles. The objective was to reduce the weight and fuel consumption of the vehicles. In this study the optimum parameters for the friction stir spot welding (FSSW) process between Al6061-T6 aluminum alloy and HSS590 high-strength steel were determined. Response surface methodology based on central composite design (CCD) with three parameters, five levels, and 19 runs was used to conduct experiments and develop mathematical regression models. The three joint parameters were tool speed, welding feed, and dwell time. Analysis of variance was then performed to examine the adequacy of the developed …
Synthesis And Characterization Of Hybrid Shell Microcapsules For Anti-Corrosion Ni-Co Coating, Hamed Sadabadi, Saeed Reza Allahkaram, Omid Ghader, Pradeep K. Rohatgi
Synthesis And Characterization Of Hybrid Shell Microcapsules For Anti-Corrosion Ni-Co Coating, Hamed Sadabadi, Saeed Reza Allahkaram, Omid Ghader, Pradeep K. Rohatgi
Journal of Metals, Materials and Minerals
This paper presents the results of the study of microcapsules synthesized using a novel hybrid shell of polyureaformaldehyde/SiO2 (PUF/SiO2) and a core of linseed oil. The synthesis was accomplished by facial polymerization combined with sol-gel of TEOS, and urea-formaldehyde resin to form the hybrid shell under optimal process parameters. The microcapsules were embedded in a metal coating using the electrodeposition method. Microcapsules were characterized by scanning electron microscope (SEM, FE-SEM), energy-dispersive spectroscopy (EDS), particle size analyzer (PSA), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The experimental results indicated that the average size of capsules synthesized umder the optimum processing …
Dyeing Of Curcumin And Durable Press Finishing With Citric Acid On Cotton Fabric Using One Step Process, Supannee Boonroeng, Piyaporn Kampeerapappun
Dyeing Of Curcumin And Durable Press Finishing With Citric Acid On Cotton Fabric Using One Step Process, Supannee Boonroeng, Piyaporn Kampeerapappun
Journal of Metals, Materials and Minerals
Cotton is an affordable and durable option for clothing. However, cotton garments tend to wrinkle easily. Therefore, cotton fabrics were studied to improve their wrinkle resistance properties. In this work, curcumin was mixed in an aqueous solution of citric acid and its catalyst and applied to cotton fabric using pad-dry-cure process for both the dyeing and finishing properties. Aloe vera extract and chitosan were used to compare for the reaction of their functional groups with carboxyl groups of citric acid on cotton fabrics. The mixture of curcumin and citric acid solution showed anti-wrinkle properties on the treated cotton. There were …
Mineralogical Studies And Optimization Of Tabling Parameters Of Low Grade Chromite Ore By Box Behnken Design Of Experiments, Amit Kumar Bhandary, Siddhartha Mukherjee, Rajib Dey, Mahua Ghosh Chaudhuri
Mineralogical Studies And Optimization Of Tabling Parameters Of Low Grade Chromite Ore By Box Behnken Design Of Experiments, Amit Kumar Bhandary, Siddhartha Mukherjee, Rajib Dey, Mahua Ghosh Chaudhuri
Journal of Metals, Materials and Minerals
Chromite ore is geologically associated with gangue materials which have lower density compared to pure chromite (FeO.Cr2O3). Gravity separation techniques are very suitable for beneficiation of low grade chromite ore. In the present study mineralogical analysis of the sample has been carried out by using Wavelength dispersive x-ray fluorescence (WDXRF), X-ray powder diffraction (XRD), Scanning electron microscopy (SEM) and Energy dispersive X-ray (EDX). The beneficiation of low grade (Cr2O3% 26.88) chromite ore has been investigated using wilfley table. Optimization has been carried out using box-behnken statistical design (BBD). The experimental parameters selected are: tilt angle, water flow rate and pre-heat …
Magnetic Nanoparticles Coated With Zwitterionic Copolymer As An Advanced Material For Rapid And Instrument-Free Biomolecular Detection In Human Serum, Supannika Boonjamnian, Varunee Sadsri, Voravee P. Hoven, Piyaporn Na Nongkhai
Magnetic Nanoparticles Coated With Zwitterionic Copolymer As An Advanced Material For Rapid And Instrument-Free Biomolecular Detection In Human Serum, Supannika Boonjamnian, Varunee Sadsri, Voravee P. Hoven, Piyaporn Na Nongkhai
Journal of Metals, Materials and Minerals
The traditional agglutination assays especially those based on polystyrene beads have been recognized as convenient tools for disease diagnosis despite their limited detection range and low sensitivity. Unlike other particles namely polystyrene beads, SiO2 and gold nanoparticles having insignificant magnetic properties, magnetic nanoparticles (MNPs) offer unique advantages as their magnetic properties for agglutination methods. In the presence of magnet, not only can they be used to enrich the samples, but also their aggregation can also be induced, providing sensitive and rapid measurements. This work aims to develop MNPs for aggregation-based biomolecular detection. The MNPs were surface-modified with PMAMPC via an …
Gas Pressure And Coating Distance For Nanohydroxyapatite Deposition On Stainless Steel 316l Using Flame Spray Technique, Angga Saputra, Utami Dyah Syafitri, Toto Sudiro, Gerald Ensang Timuda, Yessie Widya Sari
Gas Pressure And Coating Distance For Nanohydroxyapatite Deposition On Stainless Steel 316l Using Flame Spray Technique, Angga Saputra, Utami Dyah Syafitri, Toto Sudiro, Gerald Ensang Timuda, Yessie Widya Sari
Journal of Metals, Materials and Minerals
Metal implant coating engineering is needed to improve the surface biocompatibility properties of metals. For this, coating metal surfaces with bioactive and biocompatible biomaterials will be an option. Having high biocompatibility as well as similarity in chemical properties, nanohydroxyapatite may be a candidate as biomaterials for coating the metal implant. The key to the success of metal implant plating is the formation of pores which increase the bioactivity and biocompatibility properties of the implant. In this study, nanohydroxyapatite was used to be coated on stainless steel type 316L (SS316L). To ensure that the coating works properly on the surface, an …
Analysis Of The Impact Factors From The Friction Stir Welding Process For Dissimilar Butt Joints Between Semi-Solid Cast Aluminum 356 And Aisi 1018 Carbon Steel, Worapong Boonchouytan, Jaknarin Chatthong, Rommador Burapa
Analysis Of The Impact Factors From The Friction Stir Welding Process For Dissimilar Butt Joints Between Semi-Solid Cast Aluminum 356 And Aisi 1018 Carbon Steel, Worapong Boonchouytan, Jaknarin Chatthong, Rommador Burapa
Journal of Metals, Materials and Minerals
This research aimed to study the impacts of three different rotation speeds of 710, 1000, and 1400 rpm and three welding speeds of 40, 56, and 80 mm·min-1, on dissimilar butt joints between semi-solid aluminum 356 and AISI 1018 carbon steel. Welding tools were made from tungsten carbide material, and the offset was 0 mm. It was found that an increase in the rotation speed and welding speed caused accumulated heat, which led to the appropriate changes in the metallurgical structure. The rotation speed and welding speed factors had the impact on the greater blending of the two metals at …
Laser Powder Bed Fusion Of Ti6al4v-Xcu: Process Parameters, Thywill Ccphas Dzogbewu
Laser Powder Bed Fusion Of Ti6al4v-Xcu: Process Parameters, Thywill Ccphas Dzogbewu
Journal of Metals, Materials and Minerals
The original intent of coating biomedical and surgical devices surface with antibacterial agents is to prevent infections. However, the difference in the material properties between the biomedical devices and the coating materials causes the coating material to spall from the biomedical devices. To address the situation, the current research focused on investigating the possibility of using laser powder bed fusion process a subset of additive manufacturing technology to in situ alloy 1 at% Cu with Ti6Al4V. In situ alloying 1 at% Cu with Ti6Al4V would lead to the production of medical and surgical devices with inbuilt antibacterial property. To determine …
Development Of Chemically Grafted Multiwall Carbon Nanotube Onto Cellulose Fiber Sheet And Polyurethane Based Resin Composite For An Active Paper, Siripassorn Sukhkhawuttigit, Sarute Ummartyotin, Yingyot Infahsaeng
Development Of Chemically Grafted Multiwall Carbon Nanotube Onto Cellulose Fiber Sheet And Polyurethane Based Resin Composite For An Active Paper, Siripassorn Sukhkhawuttigit, Sarute Ummartyotin, Yingyot Infahsaeng
Journal of Metals, Materials and Minerals
Cellulose fibers (CFs) and carbon nanotubes (CNTs) were successfully developed on polyurethane substrate as a flexible composite paper. With small amount of CNTs, the composite was prepared by a suction filtration method. The existence of CNT additive in cellulose matrix was investigated based on the correlation of mechanical properties, thermal stability, and electrical properties. Although the highly transparent cellulose sheets impregnated with polyurethane were successfully fabricated, the low transmittance was obtained as the increasing of CNT additive. However, the dielectric properties of composite were enhanced with an addition of CNTs in the composite paper. The electrical conductivity was increased from …
Influence Of Cooling Conditions On Microstructure And Mechanical Property Of Sn-0.3ag-0.7cu Lead-Free Solder, Prajak Jattakul, Tavee Madsa, Piyawan Sunasuan, Niwat Mookam
Influence Of Cooling Conditions On Microstructure And Mechanical Property Of Sn-0.3ag-0.7cu Lead-Free Solder, Prajak Jattakul, Tavee Madsa, Piyawan Sunasuan, Niwat Mookam
Journal of Metals, Materials and Minerals
This research has investigated the influence of cooling conditions on the microstructure and mechanical properties i.e., tensile strength and microhardness of Sn-0.3Ag-0.7Cu lead-free solder. In the experiments, casting was performed at 300℃ with comparison between copper and stainless steel molds under slow and fast cooled conditions. X-ray diffractometer confirmed the presence of Cu6Sn5 and Ag3Sn phases in the solder matrix. Lead-free solder solidified under slow cooled conditions exhibited -Sn matrix with larger grain growth as compared to the fast cooled solder. The eutectic area of intermetallic compound (IMC) was found to increase with cooling rate. The tensile strength of slow …
หุ่นยนต์ 3 มิติชนิดจับที่ปลายแบบรับรู้แรงเพื่อการฟื้นฟูรยางค์ส่วนบน, เกวลี อัศวะไพฑูรย์เสริฐ
หุ่นยนต์ 3 มิติชนิดจับที่ปลายแบบรับรู้แรงเพื่อการฟื้นฟูรยางค์ส่วนบน, เกวลี อัศวะไพฑูรย์เสริฐ
Chulalongkorn University Theses and Dissertations (Chula ETD)
งานวิจัยนี้มีวัตถุประสงค์เพื่อออกแบบต้นแบบหุ่นยนต์ 3 มิติชนิดจับที่ปลายแบบรับรู้แรงที่มีระบบควบคุมทางพลศาสตร์และโปรแกรมควบคุมการทำงาน เพื่อการประยุกต์ใช้ในการฟื้นฟูรยางค์ส่วนบน โดยงานวิจัยนี้ได้ออกแบบและพัฒนาต้นแบบหุ่นยนต์ที่มีชื่อว่าหุ่นยนต์ 3DEE (3D End-effector Manipulator Arm) ซึ่งเป็นหุ่นยนต์กายภาพบำบัดชนิดจับที่ปลายที่มีจุดสัมผัสอยู่ที่บริเวณข้อมือ มีลักษณะโครงสร้างเป็น 3-dimensional five-bar linkage manipulator ซึ่งสามารถเคลื่อนไหวใน 3 มิติได้และมีโครงสร้างที่ไม่ซับซ้อน อีกทั้งหุ่นยนต์ยังถูกออกแบบให้เหมาะสำหรับหุ่นยนต์กายภาพบำบัดและคำนึงถึงความปลอดภัยของผู้ใช้เป็นหลัก ระบบควบคุมที่ใช้ในงานวิจัยนี้เป็นระบบควบคุมกำแพงเสมือนแบบสปริงและตัวหน่วงสำหรับโปรแกรมอุโมงค์เสมือนที่เหมาะสำหรับให้ผู้ป่วยได้ออกแรงเคลื่อนไหวเองโดยมีหุ่นยนต์ประคองให้อยู่ในเส้นทางเท่านั้น โปรแกรมถูกออกแบบให้สามารถปรับค่าพารามิเตอร์ต่างๆ บันทึกข้อมูลและแสดงผลข้อมูลได้ การทดสอบหุ่นยนต์เริ่มจากการทดสอบความแม่นยำของส่วนชดเชยน้ำหนักของแขนหุ่นยนต์ก่อนซึ่งเป็นส่วนสำคัญส่วนหนึ่งของระบบควบคุม ซึ่งผลที่ได้นำมาสรุปได้ว่าส่วนชดเชยน้ำหนักของแขนหุ่นยนต์มีความแม่นยำที่มาก ตามด้วยการทดสอบประสิทธิภาพของระบบควบคุม ซึ่งผลที่ได้แสดงให้เห็นว่าระบบควบคุมนี้สามารถช่วยให้เคลื่อนไหวในเส้นทางที่กำหนดได้อย่างสะดวก อีกทั้งยังออกนอกเส้นทางได้ยาก
การประยุกต์ใช้แผ่นที่ปรับค่าความแข็งด้วยลมเข้ากับมือจับแบบง่าย, เจตนิพิฐ อรุณรัตน์
การประยุกต์ใช้แผ่นที่ปรับค่าความแข็งด้วยลมเข้ากับมือจับแบบง่าย, เจตนิพิฐ อรุณรัตน์
Chulalongkorn University Theses and Dissertations (Chula ETD)
จากแนวคิดการใช้งานผิวหนังเทียมหรืออุปกรณ์ห่อหุ้มเพื่อเพิ่มความปลอดภัยและประสิทธิภาพในการทำงานของหุ่นยนต์ นำมาสู่การพัฒนาผิวหนังเทียมที่ติดตั้งบริเวณมือจับของหุ่นยนต์ โดยผิวหนังเทียมเหล่านี้จะมีค่าความแข็งที่แตกต่างกันตามการใช้งาน วิทยานิพนธ์เล่มนี้นำเสนอการออกแบบและขึ้นรูปแผ่นที่ปรับค่าความแข็งได้ (VSPs) ด้วยความดันลม ซึ่งทำหน้าที่เสมือนเป็นผิวหนังเทียมของมือจับ จากนั้นนำแผ่นดังกล่าวไปทดลองใช้กับมือจับแข็งเกร็งอย่างง่าย เพื่อหยิบจับวัตถุซึ่งไม่ทราบตำแหน่ง รูปทรงและความแข็งที่แน่ชัดด้วยวิธีการควบคุมอิมพีแดนซ์ VSPs สร้างขึ้นจากวัสดุอ่อนนุ่มประเภทซิลิโคน ซึ่งขึ้นรูปโดยใช้การหล่อและเสริมความแข็งแรงด้วยเส้นใยไฟเบอร์ มีโครงสร้างภายในเป็นทรงกระบอกเรียงตัวขนานกัน สามารถควบคุมค่าความแข็งผ่านการควบคุมค่าความดันโดยใช้ปั๊มเข็มฉีดยาร่วมกับตัวควบคุมแผนเลื่อน จากการทดลองประยุกต์ใช้ VSPs ร่วมกับมือจับแข็งเกร็งพบว่า VSPs ช่วยเพิ่มความปลอดภัยและความยืดหยุ่นในการทำงาน เนื่องจากสามารถปรับค่าความแข็งให้เหมาะสมกับการทำงานนั้น ๆ ได้ โดยการปรับค่าความแข็งเพิ่มจะช่วยลดระยะเวลาในการทำงาน หากลดค่าความแข็งจะช่วยเพิ่มความปลอดภัยและความเสถียรในการทำงานแทน
การระบายความร้อนของเเผ่นเรียบด้วยโครงสร้างเชือกดูดซับน้ำ, ชลธิชา แกล้วทนงค์
การระบายความร้อนของเเผ่นเรียบด้วยโครงสร้างเชือกดูดซับน้ำ, ชลธิชา แกล้วทนงค์
Chulalongkorn University Theses and Dissertations (Chula ETD)
การศึกษาครั้งนี้มีวัตถุประสงค์เพื่อศึกษาการประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์ งานวิจัยนี้ได้แบ่งการศึกษาออกเป็น 2 ส่วนด้วยกันคือ การศึกษาส่วนแรกเป็นการทดสอบผลของอุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์จำลอง และการศึกษาในส่วนที่ 2 เป็นการเสนอการประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์ ซึ่งได้นำเสนอต้นแบบการประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์โดยมี 3 รูปแบบ รูปแบบที่ 1 คือกรณีติดตั้งบนดาดฟ้าอาคารเรียบโดยใช้ระบบน้ำร่วมกับอาคาร รูปแบบที่ 2 คือกรณีติดตั้งบนดาดฟ้าอาคารเรียบโดยแยกระบบน้ำกับอาคาร และรูปแบบที่ 3 คือกรณีติดตั้งบนหลังคาที่มีความลาดเอียงโดยแยกระบบน้ำกับอาคาร และวิเคราะห์ความคุ้มค่าทางเศรษฐศาสตร์ โดยวิเคราะห์มูลค่าปัจจุบันสุทธิ (NPV) อัตราผลตอบแทนภายใน (IRR) วิเคราะห์ระยะเวลาคืนทุน (Payback Period) และวิเคราะห์ความอ่อนไหวของโครงการ การทดสอบอุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์จำลองแสดงให้เห็นว่าสำหรับกรณีฟลักซ์ความร้อน 205.8, 483.8 และ 661.8 W/m2 สามารถลดอุณหภูมิของแผงได้ถึง 5.9, 8.3 และ 11.3°C ซึ่งประมาณได้เป็นการเพิ่มประสิทธิภาพเซลล์แสงอาทิตย์ 2.95, 4.15 และ 5.65% ตามลำดับ และผลการวิเคราะห์ความคุ้มค่าทางเศรษฐศาสตร์ของประยุกต์อุปกรณ์ระบายความร้อนระเหยน้ำจากผ้ากับเซลล์แสงอาทิตย์ตัวอย่างที่ขนาดการติดตั้ง 6.6 kW ตลอดอายุโครงการ 25 ปี แสดงให้เห็นว่าการติดตั้งในรูปแบบที่ 1 คือกรณีติดตั้งบนดาดฟ้าอาคารเรียบโดยใช้ระบบน้ำร่วมกับอาคาร มีค่า NPV สูงสุด IRR มากสุด และระยะเวลาคืนทุนน้อยสุด ได้แก่ 109,112.11 บาท, 255.33% และ 0.39 ปี ตามลำดับ ในการวิเคราะห์ความอ่อนไหวโครงการที่พิจารณาผลกระทบจากการเปลี่ยนแปลงค่าไฟฟ้า ค่าน้ำ และค่าผลกระทบของอุณหภูมิต่อประสิทธิภาพเซลล์แสงอาทิตย์ พบว่า ค่าผลกระทบของอุณหภูมิต่อประสิทธิภาพที่เปลี่ยนไปส่งผลต่อ NPV, IRR และระยะเวลาคืนทุนมากที่สุด โดยที่การเปลี่ยนแปลงค่าน้ำมีผลกระทบน้อยที่สุด
A Numerical Study Of Flow Past Arrays Of Cylinders At Low Reynolds Number, Woraphon Wannaviroj
A Numerical Study Of Flow Past Arrays Of Cylinders At Low Reynolds Number, Woraphon Wannaviroj
Chulalongkorn University Theses and Dissertations (Chula ETD)
Coastal erosion along shorelines has increasingly been prevalent. A popular method for alleviating this problem is to use breakwaters, made of bamboo, known as “bamboo fencing”. The thesis numerically investigates steady, low-velocity flow past several geometrical configurations of bamboo fencings, modelled as array of cylinders using the ANSYS®-Fluent software. The Reynolds number based on incoming flow velocity (U∞), cylinder diameter (D), and fluid kinematic viscosity is Re = 100. Validation is done for mesh convergence and time-step size for the two-dimensional flow past a circular cylinder. For a pair of side-by-side arranged cylinders, it is found that the effect of …
Lightning Strike Response Of Composite Structures: A Review, Akhileshwar Pandey, Ashutosh Kumar Upadhyay, Karunesh Kumar Shukla
Lightning Strike Response Of Composite Structures: A Review, Akhileshwar Pandey, Ashutosh Kumar Upadhyay, Karunesh Kumar Shukla
Journal of Metals, Materials and Minerals
Wind turbines and aircraft are generally made of less conductive carbon/glass composites. Significant damages may occur to these materials if they are struck by high energy lightning strikes. Damage and structural response of composites is essentially a multiphysics domain, involving thermal, electrical, magnetic and structural analysis. In this article, the fundamental physics of lightning, multiphysics analysis, numerical implementation and experimental studies about composite materials are reviewed. The relevant international standards and possible characterization methods of lightning strike damage are also reproduced in this article. In addition to this, the current and prospective technologies, to protect composite from lightning strikes are …
Wear Behavior Of Aluminium 6061 Alloy Reinforced With Coated/Uncoated Multiwalled Carbon Nanotube And Graphene, Vijee Kumar, Kempaiah Ujjaini Nagegowda, Satish Babu Boppana, Ramesh Sengottuvelu, Palanikumar Kayaroganam
Wear Behavior Of Aluminium 6061 Alloy Reinforced With Coated/Uncoated Multiwalled Carbon Nanotube And Graphene, Vijee Kumar, Kempaiah Ujjaini Nagegowda, Satish Babu Boppana, Ramesh Sengottuvelu, Palanikumar Kayaroganam
Journal of Metals, Materials and Minerals
The current study deals with the fabrication and investigation of wear characteristics of Aluminium 6061(Al6061) hybrid metal matrix composites (MMCs) processed through powder metallurgy technique. Al6061 hybrid MMCs involving fixed 2 wt% of coated/uncoated multiwalled carbon nanotubes (MWCNTs) and varying weight percentages of graphene were fabricated through ball milling procedure. To enhance the scattering of MWCNTs in the matrix, MWCNTs were coated by means of copper through electroless deposition method. Dry sliding wear conduct of Al6061 MMCs was investigated using a pin-on-disc wear testing machine. It was found that at lower load, composites exhibited lower wear resistance than base alloy …
Improvement On Cost-Performance Ratio Of Fiberglass/Carbon Fiber Hybrid Composite, Nathawat Poopakdee, Warut Thammawichai
Improvement On Cost-Performance Ratio Of Fiberglass/Carbon Fiber Hybrid Composite, Nathawat Poopakdee, Warut Thammawichai
Journal of Metals, Materials and Minerals
Fiberglass composite (FG) is widely used as a metal substitute in general applications due to its corrosion and chemical resistance, relatively high strength, and low cost. Still, the FG is deficient in performance and relatively heavy for airframes. Carbon fiber composite (CF) is utilized instead as it has greater performance and lower weight. However, the CF is brittle and expensive. Thus, in this work, we combine FG and CF into two types of hybrid composites to achieve a cost-effective solution with greater or comparable mechanical properties to those of CF. The first one uses FG as core and CF as …
Efficiency Of Tri-N-Octylamine For The Liquid-Liquid Extraction Of Co (Ii) From Acidic Chloride Medium, Aishwarya Mishra, Nilam Swain, Sanghamitra Pradhan, Sujata Mishra
Efficiency Of Tri-N-Octylamine For The Liquid-Liquid Extraction Of Co (Ii) From Acidic Chloride Medium, Aishwarya Mishra, Nilam Swain, Sanghamitra Pradhan, Sujata Mishra
Journal of Metals, Materials and Minerals
Cobalt criticality is increasing as a function of time and this concern has impelled researchers to ascertain efficient recovery schemes of cobalt. In this paper, an extraction strategy for cobalt utilizing tri-n-octyl amine (TOA) in kerosene from acidic chloride media has been developed. The extraction percentage was found to be 76.7 using 1.5M TOA. The extracted species has been formulated as (R3NH) CoCl3 based on the findings of slope analysis. Influence of various salting out agents like NH4Cl, KCl, and NaCl on the percentage extraction has been analysed and KCl emerged as beneficial for extraction. The estimated values of enthalpy …
Microstructure And Properties Of Zirconia-Alumina Composites Fabricated Via Powder Injection Molding, Nalattaporn Saelee, Nutthita Chuankrerkkul, Panitarn Wanakamol
Microstructure And Properties Of Zirconia-Alumina Composites Fabricated Via Powder Injection Molding, Nalattaporn Saelee, Nutthita Chuankrerkkul, Panitarn Wanakamol
Journal of Metals, Materials and Minerals
This study aimed to fabricate zirconia-alumina composites via powder injection molding and investigated the effects of alumina addition on microstructure as well as physical properties of the composites. Zirconia-alumina composites were prepared using polyethylene glycol (PEG) and polyvinyl butyral (PVB) as binders. The powder loading was fixed at 38 vol%, and PEG: PVB binder weight ratio was fixed at 80:20. Alumina content within ceramic component was varied at 0, 10, 20, 30, 40 and 50 vol% to observe the effect of alumina on the composite structures and properties. The injection molding was done at 190℃ followed by water debinding of …
Enhancing Stability And Antioxidant Efficacy Of Fisetin By Encapsulating As Β-Cyclodextrin Inclusion Complex With Porous Polylactic Acid Film From Breath Figure, Charasphat Preuksarattanawut, Warinyupa Mangmee, Munchumas Prousoontorn, Ekasit Nisarattanaporn, Krisana Siraleartmukul
Enhancing Stability And Antioxidant Efficacy Of Fisetin By Encapsulating As Β-Cyclodextrin Inclusion Complex With Porous Polylactic Acid Film From Breath Figure, Charasphat Preuksarattanawut, Warinyupa Mangmee, Munchumas Prousoontorn, Ekasit Nisarattanaporn, Krisana Siraleartmukul
Journal of Metals, Materials and Minerals
This research aims to investigate the scope of fisetin (FIT)/β-cyclodextrin (β-CD) inclusion complexes with the ratios of 1:2 and 2:1 mole by means of freeze-drying, kneading and physical mixing methods (controlled process). Moreover, the complex compounds are analyzed by Fourier-Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). The results show that the most suitable preparation method of fisetin (FIT)/β-CD complex is the freeze-drying method with the fisetin (FIT) to β-CD ratio at 1:2. The emission of FIT/β-CD was investigated and it is found that the emission rate of freeze-dried FIT/β-CD in 1:2 ratio by freeze-drying method is lower than …
Study Of Mechanical Properties And Characteristics Of Eco-Fibres For Sustainable Children's Clothing, Siti Shukhaila Shaharuddin, Marzie Hatef Jalil, Kaveh Moghadasi
Study Of Mechanical Properties And Characteristics Of Eco-Fibres For Sustainable Children's Clothing, Siti Shukhaila Shaharuddin, Marzie Hatef Jalil, Kaveh Moghadasi
Journal of Metals, Materials and Minerals
The aim of this paper is to study the application of eco-fibres as a new approach to achieve the multifunctional design for children’s clothing toward sustainability in the clothing industry. In this regard, this study focuses on the evaluation of the fabrics’ mechanical properties including tensile strength and microstructural details as critical points for multifunctional children's clothing purposes. The eco-fibre fabrics studied are organic cotton twill and recycled polyester. Studies have proven that frequent laundering and dry-cleaning result in increased pilling. Furthermore, high quality of colour fastness properties was found in 100% organic woven cotton fabric and recycled polyester fabric …