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2017

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Articles 2491 - 2520 of 8353

Full-Text Articles in Engineering

Vetë-Shërimi I Betonit Me Anë Të Baktereve, Endrit Koçinaj Jul 2017

Vetë-Shërimi I Betonit Me Anë Të Baktereve, Endrit Koçinaj

Theses and Dissertations

Betoni është materiali më i përdorur në botën e ndërtimit. Rezistenca e lartë në shtypje dhe çmimi i lirë e bëjnë atë shumë të kërkuar në botën e ndërtimit. Humbja e vetive kryesore të tij dhe paraqitja e plasaritjeve janë probleme që kërkojnë studime të vazhdueshme. Kjo temë studion përmirësimin e performancës së betonit me ndihmën e baktereve të ndryshme pas paraqitjes së plasaritjeve. Përdorimi i baktereve në beton, ka arritur në zhvillimin e një betoni të posaçëm që arrinë t’i mbyll plasaritjet vetëvetiu me aktivizimin e këtyre baktereve. Hulumtimet e deri tanishme na kanë dhënë rezultate shumë të mira. …


Projekti I Shfrytëzimit Të Gëlqerorëve Në Vendburimin ,,Gryka”-Shalë, Armend Aliu Jul 2017

Projekti I Shfrytëzimit Të Gëlqerorëve Në Vendburimin ,,Gryka”-Shalë, Armend Aliu

Theses and Dissertations

Punimi me titull “Projekti i shfrytëzimit të gëlqerorëve në vendburimin Gryka”-Shalë, përshkruan më hollësisht projektin e vendburimi të gëlqeroreve me pikat gjeodezike sipas hartës së situacioni. Ky guri gëlqerore që nxirren nga ky vendburim, është i nevojshëm për punët ndërtimore në ndërtimtari, posaçërisht në infrastrukturën e rrugëve dhe punimeve tjera sipas kërkesave të tregut. Në ketë punim kemi marre për bazë, analizën e mineralit, testimet gjeomekanike, karakteristikat gjeolo-inxhinierike, kualitetin dhe rezervat, përshkrimin teknik, këndet e shkalleve të gurores sipas standardeve Gjeoteknike, Faktorin e sigurisë Fs ngarkimin dhe transportin, masat mbrojtëse, pjesën ndërtimore, rregullimin e punishtes, trajtimin e ujërave sipërfaqësorë dhe …


Prodhimet Nga Argjila Të Prodhuesit “Brickos”, Vigan Kastrati Jul 2017

Prodhimet Nga Argjila Të Prodhuesit “Brickos”, Vigan Kastrati

Theses and Dissertations

Kjo temë ka për qëllim shtjellimin e punëve dhe proceseve që marrin pjesë në prodhimin e materialeve argjilore, saktësisht bllokave në fabrikën “BRICKOS”, e cila ndodhet në Kamenicë.Si fillim kemi shtjelluar pjesën teorike të materialeve argjilore, të cilën e kemi marrë nga literatura të ndryshme të cilat janë të cekura në fund tek referencat.Më pas kemi filluar me punën konkrete e cila është zhvilluar në fabrikën e lartë cekur, ku me ndihmën e teknologut të asaj fabrike kam fituar njohuri të shumta mbi zhvillimin e proceseve të prodhimit të produkteve argjilore. Ne aty kemi përcjellë të gjitha proceset teknologjike që …


Analysis Of Time-Dependent Bearing Capacity Of A Driven Pile In Clayey Soils By Total Stress Method, Lin Li, Jingpei Li, De'an Sun, Weibing Gong Jul 2017

Analysis Of Time-Dependent Bearing Capacity Of A Driven Pile In Clayey Soils By Total Stress Method, Lin Li, Jingpei Li, De'an Sun, Weibing Gong

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This paper proposes an analytical approach to evaluate the time-dependent bearing capacity of a driven pile in clayey soils by taking the pile installation and subsequent reconsolidation effects into consideration. The process of pile installation is modeled by undrained expansion of a spherical cavity at the pile tip and a cylindrical cavity around the pile shaft. The cavity expansion solution, which is based on a K0-consolidated anisotropic modified Cam-clay model (K0-AMCC), is used to capture the pile installation effects. After pile installation, the dissipation of the excess pore water and the increase of the effective stress in the surrounding soil …


Solvent Based 3d Printing Of Biopolymer/Bioactive Glass Composite And Hydrogel For Tissue Engineering Applications, Krishna Kolan, Yong Liu, Jakeb Baldridge, Caroline Murphy, Julie A. Semon, D. E. Day, Ming-Chuan Leu Jul 2017

Solvent Based 3d Printing Of Biopolymer/Bioactive Glass Composite And Hydrogel For Tissue Engineering Applications, Krishna Kolan, Yong Liu, Jakeb Baldridge, Caroline Murphy, Julie A. Semon, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Three-dimensional (3D) bioprinting is an emerging technology in which scaffolding materials and cell-laden hydrogels may be deposited in a pre-determined fashion to create 3D porous constructs. A major challenge in 3D bioprinting is the slow degradation of melt deposited biopolymer. In this paper, we describe a new method for printing poly-caprolactone (PCL)/bioactive borate glass composite as a scaffolding material and Pluronic F127 hydrogel as a cell suspension medium. Bioactive borate glass was added to a mixture of PCL and organic solvent to make an extrudable paste using one syringe while hydrogel was extruded and deposited in between the PCL/borate glass …


Understanding The Surface Fouling Mechanism Of Ultrananocrystalline Diamond Microelectrodes Using Microfluidics For Neurochemical Detection, An-Yi Chang Jul 2017

Understanding The Surface Fouling Mechanism Of Ultrananocrystalline Diamond Microelectrodes Using Microfluidics For Neurochemical Detection, An-Yi Chang

Doctoral Dissertations

Electrochemical methods are widely used for chronic neurochemical sensing, but thus far, the organic solution redox reactions fouled the electrodes' surface. It caused the reduction of sensitivity and the electrodes' lifetime.

Here, we present the boron-doped nanocrystalline diamond microelectrodes (BDUNCD) as the next generation electrode material for neurochemical sensor development. To aid in long-term chronic monitoring of neurochemicals, they have a wide window of electrochemical potential, extremely low background current, and excellent chemical inertness. The main research goal is to reduce the rate of electrode fouling due to the reaction by-products, and significantly extend their useful lifetime.

We systematically characterize …


Solubility And Thermodynamic Modeling Of Carcinogenic Nitrosamines In Aqueous Amine Solvents For Co2 Capture, Jesse Thompson, Naser Matin, Kunlei Liu Jul 2017

Solubility And Thermodynamic Modeling Of Carcinogenic Nitrosamines In Aqueous Amine Solvents For Co2 Capture, Jesse Thompson, Naser Matin, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

A better understanding of key fundamental properties of nitrosamines, including their solubility in aqueous amine solvents, is needed to understand and accurately model the vapor-phase emission levels from operating CO2 capture systems. In this work, the first experimental Henry's volatility coefficient of a nitrosamine was obtained with a novel method using static headspace solid phase micro extraction (SPME) and gas chromatography mass spectrometry (GC/MS). The experimentally determined Henry's volatility coefficient of nitrosopyrrolidine (NPY) was found to be around 0.02 (dimensionless) at 25 °C, and falls in the range of a semi-volatile compound. A linear temperature dependency of the Henry's …


Techno-Economic Analysis Of A Secondary Air Stripper Process, J. R. Heberle, Heather Nikolic, Jesse Thompson, Kunlei Liu, Lora L. Pinkerton, David Brubaker, James C. Simpson, Song Wu, Abhoyjit S. Bhown Jul 2017

Techno-Economic Analysis Of A Secondary Air Stripper Process, J. R. Heberle, Heather Nikolic, Jesse Thompson, Kunlei Liu, Lora L. Pinkerton, David Brubaker, James C. Simpson, Song Wu, Abhoyjit S. Bhown

Center for Applied Energy Research Faculty and Staff Publications

We present results of an initial techno-economic assessment on a post-combustion CO2 capture process developed by the Center for Applied Energy Research (CAER) at the University of Kentucky using Mitsubishi Hitachi Power Systems’ H3-1 aqueous amine solvent. The analysis is based on data collected at a 0.7 MWe pilot unit combined with laboratory data and process simulations. The process adds a secondary air stripper to a conventional solvent process, which increases the cyclic loading of the solvent in two ways. First, air strips additional CO2 from the solvent downstream of the conventional steam-heated thermal stripper. This extra stripping …


Thermal Degradation Pathways Of Aqueous Diamine Co2 Capture Solvents, Jesse Thompson, Henry Richburg, Kunlei Liu Jul 2017

Thermal Degradation Pathways Of Aqueous Diamine Co2 Capture Solvents, Jesse Thompson, Henry Richburg, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

Diamines have shown promise as CO2 capture solvents, yet very little is known about their pathway for thermal degradation. In this study, diamine thermal degradation was quantitatively monitored in lab-scale experiments on four aqueous diamine solvents; ethylenediamine (EDA) 1,2-propanediamine (1,2-DAP), 1,3-diaminopropane (1,3-DAP) and N-methyl-1,2-ethanediamine (NMEDA), to gain a more comprehensive understanding of their degradation pathway(s). The major degradation products were identified by high resolution time-of-flight mass spectrometry (TOF-MS). Degradation pathways were proposed showing that the primary thermal degradation route for this class of amine are through carbamate formation followed by intermolecular cyclization to form an imidazolidinone or nucleophilic attack …


Anion Exchange Membrane Capacitive Deionization Cells, Ayokunle Omosebi, Xin Gao, Nicolas Holubowitch, Zhiao Li, James Landon, Kunlei Liu Jul 2017

Anion Exchange Membrane Capacitive Deionization Cells, Ayokunle Omosebi, Xin Gao, Nicolas Holubowitch, Zhiao Li, James Landon, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

The electrochemical response of capacitive deionization (CDI) employing a single anion exchange membrane (AEM-CDI) is contrasted to conventional two-membrane CDI (MCDI) formed with complementary anion and cation exchange membranes. Pristine activated carbon cloth electrodes that possess native positive surface charge in solution were used as both anode (positive electrode) and cathode (negative electrode) in these cells. In a separate set of tests to investigate the impact of surface charge modification on deionization responses, the single and dual membrane cells were formed with asymmetric electrodes (AEM-aCDI and aMCDI) consisting of nitric acid oxidized electrodes that possess negative surface charge as the …


Solvent Degradation And Emissions From A 0.7mwe Pilot Co2 Capture System With Two-Stage Stripping, Jesse Thompson, Heather Nikolic, Megan Combs, Saloni Bhatnagar, Jonathan Pelgen, Keemia Abad, Kunlei Liu Jul 2017

Solvent Degradation And Emissions From A 0.7mwe Pilot Co2 Capture System With Two-Stage Stripping, Jesse Thompson, Heather Nikolic, Megan Combs, Saloni Bhatnagar, Jonathan Pelgen, Keemia Abad, Kunlei Liu

Center for Applied Energy Research Faculty and Staff Publications

The UKy-CAER team successfully tested an advanced 0.7 MWe post-combustion CO2 capture system on a coal-fired power plant using a heat integration process combined with two-stage stripping to enhance the CO2 absorber performance. One of the unique feature of the UKy-CAER integrated process is a two-stage stripping unit for solvent regeneration. The secondary stripper is empowered by the heat rejection from a conventional steam-heated (primary) stripper. The secondary stripper outlet stream at the commercial scale can be used as boiler secondary combustion air, consequently enriching the flue gas with CO2, resulting in less energy penalty required …


Task Assignment And Path Planning For Multiple Autonomous Underwater Vehicles Using 3d Dubins Curves, Wenyu Cai, Meiyan Zhang, Y. Rosa Zheng Jul 2017

Task Assignment And Path Planning For Multiple Autonomous Underwater Vehicles Using 3d Dubins Curves, Wenyu Cai, Meiyan Zhang, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates the task assignment and path planning problem for multiple AUVs in three dimensional (3D) underwater wireless sensor networks where nonholonomic motion constraints of underwater AUVs in 3D space are considered. The multi-target task assignment and path planning problem is modeled by the Multiple Traveling Sales Person (MTSP) problem and the Genetic Algorithm (GA) is used to solve the MTSP problem with Euclidean distance as the cost function and the Tour Hop Balance (THB) or Tour Length Balance (TLB) constraints as the stop criterion. The resulting tour sequences are mapped to 2D Dubins curves in the X − …


Synthesis, Characterization And Photocatalytic Activity Of Ag Metallic Particles Deposited Carbon-Doped Tio2 Nanocomposites Supported On Stainless Steel Mesh, J. O. Tijani, T. C. Totito, O. O. Fatoba, O. O. Babajide, L. F. Petrik Jul 2017

Synthesis, Characterization And Photocatalytic Activity Of Ag Metallic Particles Deposited Carbon-Doped Tio2 Nanocomposites Supported On Stainless Steel Mesh, J. O. Tijani, T. C. Totito, O. O. Fatoba, O. O. Babajide, L. F. Petrik

Mining Engineering Faculty Research & Creative Works

Abstract: In this present work, post deposition of metallic Ag nanoparticles on carbon-doped TiO2 nanocomposites supported on stainless steel mesh was achieved via a combination of sol–gel and thermal evaporation techniques. Poly acrylonitrile dissolved in dimethyl formamide, and titanium tetra chloride was used as a carbon and titanium precursor, respectively. The photocatalytic activity of the prepared supported catalysts was evaluated by the degradation of an aqueous solution of methylene blue as a model pollutant under ultra-violet light irradiation. The prepared photocatalysts were characterized by several analytical techniques such as high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, Brunauer–Emmett–Teller …


Effect Of Wall Cooling On Boundary-Layer-Induced Pressure Fluctuations At Mach 6, C. Zhang, Lian Duan, M. Choudhari Jul 2017

Effect Of Wall Cooling On Boundary-Layer-Induced Pressure Fluctuations At Mach 6, C. Zhang, Lian Duan, M. Choudhari

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.


Design And Analysis Of Adaptive Control Systems Over Wireless Networks, Ali Albattat, Benjamin Gruenwald, Tansel Yucelen Jul 2017

Design And Analysis Of Adaptive Control Systems Over Wireless Networks, Ali Albattat, Benjamin Gruenwald, Tansel Yucelen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this paper, we study the design and analysis of adaptive control systems over wireless networks using event-triggering control theory. The proposed event-triggered adaptive control methodology schedules the data exchange dependent upon errors exceeding user-defined thresholds to reduce wireless network utilization and guarantees system stability and command following performance in the presence of system uncertainties. Specifically, we analyze stability and boundedness of the overall closed-loop dynamical system, characterize the effect of user-defined thresholds and adaptive controller design parameters to the system performance, and discuss conditions to make the resulting command following performance error sufficiently small. An illustrative numerical example is …


Novel Layered Double Hydroxides-Hydroxyapatite/Gelatin Bone Tissue Engineering Scaffolds: Fabrication, Characterization, And In Vivo Study, Fateme Fayyazbakhsh, Mehran Solati-Hashjin, Abbas Keshtkar, Mohammad Ali Shokrgozar, Mohammad Mehdi Dehghan, Bagher Larijani Jul 2017

Novel Layered Double Hydroxides-Hydroxyapatite/Gelatin Bone Tissue Engineering Scaffolds: Fabrication, Characterization, And In Vivo Study, Fateme Fayyazbakhsh, Mehran Solati-Hashjin, Abbas Keshtkar, Mohammad Ali Shokrgozar, Mohammad Mehdi Dehghan, Bagher Larijani

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Developing Porous Biodegradable Scaffolds through Simple Methods is One of the Main Approaches of Bone Tissue Engineering (BTE). in This Work, a Novel BTE Composite Containing Layered Double Hydroxides (LDH), Hydroxyapatite (HA) and Gelatin (GEL) Was Fabricated using Co-Precipitation and Solvent-Casting Methods. Physiochemical Characterizations Showed that the Chemical Composition and Microstructure of the Scaffolds Were Similar to the Natural Spongy Bone. Interconnected Macropores Ranging over 100 to 600 Μm Were Observed for Both Scaffolds While the Porosity of 90 ± 0.12% and 92.11 ± 0.15%, as Well As, Young's Modulus of 19.8 ± 0.41 and 12.5 ± 0.35 GPa Were …


Proposal For Monitoring Concrete Painting As A Preventive Maintenance Tool (Abutments And Pier Caps), Danny Wells, Sudhir Palle, Theodore Hopwood Ii Jul 2017

Proposal For Monitoring Concrete Painting As A Preventive Maintenance Tool (Abutments And Pier Caps), Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

One of the growing number of preventive bridge maintenance activities conducted by the Kentucky Transportation Cabinet (KYTC) is washing and applying thin film protective coatings to bridge abutments and piers. Previous work conducted by Kentucky Transportation Center (KTC) under KYSPR 10-406 documented increased chloride contamination of these bridge components and the need for protective coatings. KYTC Contract ID 162952 includes, among other tasks, cleaning and coating specific concrete elements of eighteen bridges in Anderson and Woodford counties (District 7). These elements are interior faces of the barrier walls, pier caps, and abutment seats. The contract was let on July 29, …


Proposed Testing Of Concrete Sealers, Danny Wells, Sudhir Palle, Theodore Hopwood Ii Jul 2017

Proposed Testing Of Concrete Sealers, Danny Wells, Sudhir Palle, Theodore Hopwood Ii

Kentucky Transportation Center Technical Assistance Report

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the Kentucky Transportation Cabinet (KYTC) can result in problematic levels of chloride at steel reinforcing depths in a relatively short amount of time. With the advent of liquid applied pre-treatment deicing chemicals, testing performed in Kentucky indicate chloride levels in bridge decks at a depth of two inches have increased significantly.

Chlorides, in sufficient concentrations, will cause corrosion of steel reinforcement in bridge decks. Previous studies have shown that de-icing chemicals and practices used by the …


Kinetic Energy Investigation, Mike Jackson Jul 2017

Kinetic Energy Investigation, Mike Jackson

High School Lesson Plans

Students will build a mouse trap powered car that converts elastic potential energy contained in the trap’s spring to linear kinetic energy of the car. The release of this energy results in a net force which leads to linear acceleration. This acceleration can be measured with Vernier Logger Pro®, and using Newton’s Second Law of Motion, the net force can be calculated. Finally, using the concept of work, the final kinetic energy of the car can be calculated. Once students become familiar with the calculation of work and energy, the teacher will challenge the students to modify their cars to …


Stair Negotiation Made Easier Using Novel Interactive Energy-Recycling Assistive Stairs, Yun Seong Song, Sehoon Ha, Hsiang Hsu, Lena H. Ting, C. Karen Liu Jul 2017

Stair Negotiation Made Easier Using Novel Interactive Energy-Recycling Assistive Stairs, Yun Seong Song, Sehoon Ha, Hsiang Hsu, Lena H. Ting, C. Karen Liu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Here we show that novel, energy-recycling stairs reduce the amount of work required for humans to both ascend and descend stairs. Our low-power, interactive, and modular steps can be placed on existing staircases, storing energy during stair descent and returning that energy to the user during stair ascent. Energy is recycled through event-triggered latching and unlatching of passive springs without the use of powered actuators. When ascending the energy-recycling stairs, naive users generated 17.4 ± 6.9% less positive work with their leading legs compared to conventional stairs, with the knee joint positive work reduced by 37.7 ± 10.5%. Users also …


Collection And Analysis Of 2013-2014 Travel Time Data, Mei Chen, Xu Zhang Jul 2017

Collection And Analysis Of 2013-2014 Travel Time Data, Mei Chen, Xu Zhang

Kentucky Transportation Center Research Report

This report documents the findings of Planning Study 27, Collection and Analysis of 2013-2014 Travel Time Data, which is a continuation of Planning Study 24, Analysis of Historical Travel Time Data. The main scope is to analyze newly acquired link-referenced speed data on Kentucky roads from 2013 and 2014.

Results of the analysis demonstrate the value of probe data in measuring and tracking the performance of roadways across several years. In addition, such data can help KYTC and MPOs identify bottlenecks in the network, prioritize improvement strategies, and assess the effectiveness of projects. As data collection techniques advance, …


Laser-Assisted Metal Organic Chemical Vapor Deposition Of Gallium Nitride, Hossein Rabiee Golgir Jul 2017

Laser-Assisted Metal Organic Chemical Vapor Deposition Of Gallium Nitride, Hossein Rabiee Golgir

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Due to its unique properties, gallium nitride is of great interest in industry applications including optoelectronics (LEDs, diode laser, detector), high power electronics, and RF and wirelss communication devices. The inherent shortcomings of current conventional deposition methods and the ever-increasing demand for gallium nitride urge extended efforts for further enhancement of gallium nitride deposition. The processes of conventional methods for gallium nitride deposition, which rely on thermal heating, are inefficient energy coupling routes to drive gas reactions. A high deposition temperature (1000-1100 °C) is generally required to overcome the energy barriers to precursor adsorption and surface adatom migration. However, there …


Investigating Diversity In Open Multiagent Team Formation, Pooja Ahuja Jul 2017

Investigating Diversity In Open Multiagent Team Formation, Pooja Ahuja

School of Computing: Dissertations, Theses, and Student Research

Team formation is the most rudimentary form of interactions in distributed AI and multiagent systems as it allows coherent collections of agents to work together in a beneficial manner towards a common goal of interest. Basically, individual expertise are assembled together in an additive fashion for accomplishing tasks together. A plethora of the related studies found in the literature often make several unrealistic assumptions such as coordination amongst the agents, or agents having knowledge of the whole environment, or agents and/or tasks are of the same kind, or a static environment setting. Against this background, we argue that there are …


Querying And Visualization Of Moving Objects Using Constraint Databases, Semere M. Woldemariam Jul 2017

Querying And Visualization Of Moving Objects Using Constraint Databases, Semere M. Woldemariam

School of Computing: Dissertations, Theses, and Student Research

Good querying and visualization of moving objects and their trajectories is still an open problem. This thesis investigates three types of moving objects. First, projectiles, whose parabolic motion is difficult to represent. Second, moving objects that slide down a slope. The representation of these objects is challenging because of their accelerating motion. Third, the motion of migrating animals. The motion of migrating animals is challenging because it also involves some spatio-temporal interpolation. The thesis shows a solution to these problems using ideas from physics and an implementation in the MLPQ constraint databases system. The MLPQ implementation enables several complex spatio-temporal …


Book Review - Dixie Highway: Road Building And The Making Of The Modern South, 1900-1930, Rebecca Rose Jul 2017

Book Review - Dixie Highway: Road Building And The Making Of The Modern South, 1900-1930, Rebecca Rose

Georgia Library Quarterly

No abstract provided.


Mechanical And Thermal Properties Of Eucalyptus Fiber Composites From Blend Between Biodegradable Poly(Butylene Succinate) And Recycled Pet, N Hongsriphan, P Dangmanee, M Mankrut, W Jantaraka Jul 2017

Mechanical And Thermal Properties Of Eucalyptus Fiber Composites From Blend Between Biodegradable Poly(Butylene Succinate) And Recycled Pet, N Hongsriphan, P Dangmanee, M Mankrut, W Jantaraka

Journal of Metals, Materials and Minerals

The goal of this study was to enhance rigidity and to reduce cost of the PBS-based composites by blending with recycled poly(ethylene terephthalate) (r-PET) and Eucalyptus fibers. Prior compounding, Eucalyptus fibers were treated with alkali and γ-methacryloxypropyl trimethoxysilane (MPS) solution for compatibility improvement. PBS and r-PET were melt blended in a twin-screw extruder with the weight ratio of 95/5, 90/10, and 80/20 wt%, and compounded with MPS treated Eucalyptus fibers using fiber loading of 3, 5, and 7 wt% of composites. Samples were characterized by tensile test, notched Izod impact test, SEM, NMR, and DSC. It was found that r-PET …


Study On Physical, Optical And Luminescence Of Er3+ In K2o-Cao-B2o3 Glasses For Photonic Application, N Wantana, S Insiripong, Y Ruangthaweep, J Kaewkhao Jul 2017

Study On Physical, Optical And Luminescence Of Er3+ In K2o-Cao-B2o3 Glasses For Photonic Application, N Wantana, S Insiripong, Y Ruangthaweep, J Kaewkhao

Journal of Metals, Materials and Minerals

In this work, potassium calcium borate glasses doped with of Er3+ ions (KCaBEr) have been prepared by a melt quenching technique. The glass physical, optical and luminescence properties have been investigated as a function of Er2O3 concentration. Density was measured by Archimedes' principle and brought to calculate the molar volume. The optical absorption spectra were measured in the ultraviolet, visible light and near-infrared regions. The emission and excitation spectra represents the strong emission from glass sample. All results indicate the potential to use KCaBEr glass in the photonic applications such as laser and optical amplification.


Eu3+ Doped Borosilicate Glass For Solid-State Luminescence Material, S Rakpanich, N Wantana, Y Ruangthaweep, J Kaewkhao Jul 2017

Eu3+ Doped Borosilicate Glass For Solid-State Luminescence Material, S Rakpanich, N Wantana, Y Ruangthaweep, J Kaewkhao

Journal of Metals, Materials and Minerals

The Eu3+ doped potassium borosilicate (KBSi:Eu3+) glasses were prepared by the melt quenching technique. The physical, optical and luminescence properties of glasses were investigated. Glass density and molar volume increase with increasing of Eu2O3 concentration. Glasses absorbed photons in the visible light and near infrared region. Since 394 nm excitation, glasses emitted the strong light with 613 nm in milliseconds of lifetime. CIE 1931 chromaticity diagram exhibits that emission from KBSi:Eu3+ glass is reddish-orange light. In summary, this KBSiEu glass performs the interesting property for using in the photonic devices such as solid-state laser and LEDs.


Antireflective Surface Of Nanostructures Fabricated By Cf4 Plasma Etching, W Somrang, S Denchitcharoen, P Eiamchai, M Horprathum, C Chananonnawathorn Jul 2017

Antireflective Surface Of Nanostructures Fabricated By Cf4 Plasma Etching, W Somrang, S Denchitcharoen, P Eiamchai, M Horprathum, C Chananonnawathorn

Journal of Metals, Materials and Minerals

In this research, the nanostructures surface were fabricated by the CF4 plasma etching process on the SiO2-based substrates for antireflection applications. The nickel films were firstly deposited on the substrates by the sputtering system. The prepared Ni layers were then annealed at 500°C for 1 minute in order to promote dewetting process to be used as metal masks. During the etching process, CF4 etching condition was performed for 15-60 min to create the SiO2 nanopillars. After the etching process, the samples were immersed in nitric acid for 5 min to remove the nickel masks. The SiO2 nanopillars without Ni were …


Effect Of Sputtering Power On The Structure Of Dc Magnetron Sputtered Vanadium Nitride Thin Films, A Buranawong, N Witit-Anun Jul 2017

Effect Of Sputtering Power On The Structure Of Dc Magnetron Sputtered Vanadium Nitride Thin Films, A Buranawong, N Witit-Anun

Journal of Metals, Materials and Minerals

Vanadium nitride (VN) thin films were deposited on Si substrates by reactive DC unbalanced magnetron sputtering. Effect of sputtering power on the structure of the as-deposited films was investigated. The crystal structure, thickness, roughness, surface morphology and chemical composition of the films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. The results showed that the as-deposited VN thin films had fcc structure with (111), (200) and (220) planes, varying with the sputtering power. The crystallite size and lattice constant of films were in the range …