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2020

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Articles 481 - 510 of 725

Full-Text Articles in Materials Science and Engineering

Development Of B-Type And Multi-Ion Doped Carbonated Hydroxyapatite Bioceramics, Safarzadeh Marjan Apr 2020

Development Of B-Type And Multi-Ion Doped Carbonated Hydroxyapatite Bioceramics, Safarzadeh Marjan

Student Works (2020-2029)

The present research is aimed to investigate the effect of varying the carbonate to phosphate (CO32−/ PO43‒) molar ratios from 0.5 to 5 on the physical and mechanical properties of carbonated hydroxyapatite (CHA) synthesized by a wet chemical method. The sintering was performed under dry carbon dioxide atmosphere at 900 °C to maintain the B-type CHA structure. It was found that increases in CO32−/ PO43‒ ratio was accompanied by an increase in the c/a lattice ratio. The diffraction peaks of the synthesized 0.5-5 CHA powders exhibited a single phase material except for 5CHA which revealed the some minor calcite or …

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Poly(Vinyl Alcohol)/Α-Chitin/Nanocellulose Composites Developed From Oil Palm Empty Fruit Bunch (Opefb) For Removal Of Cationic Dyes, Chun Fah Mok Apr 2020

Poly(Vinyl Alcohol)/Α-Chitin/Nanocellulose Composites Developed From Oil Palm Empty Fruit Bunch (Opefb) For Removal Of Cationic Dyes, Chun Fah Mok

Student Works (2020-2029)

In search of an eco-friendly polymeric adsorbent for dye effluent treatment application, poly(vinyl alcohol) (PVA)/chitin/nanocellulose composites were synthesized. The composites were reinforced by oil palm empty fruit bunch fibers (OPEFB)-derived nanocrystalline cellulose (NCC). With addition of 1 wt.% NCC, a maximum improvement of 57.64% and 50.66% in tensile strength and Young’s Modulus were achieved, respectively. However, the PVA-based composites exhibited low resistance in aqueous medium. Hence, maleic acid (MA) was incorporated, in view of modifying PVA-based composites through cross-linking reactions. The effect of varying chitin content (10 wt.%-30 wt.%) and MA content (10%-50% based on total solid content of composite) …

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A Novel Method For Making Titanium Dioxide For Photocatalytic Applications, Gary Wilson Apr 2020

A Novel Method For Making Titanium Dioxide For Photocatalytic Applications, Gary Wilson

Graduate Theses & Non-Theses

Titanium dioxide possesses near-ideal properties for large-scale application as a photocatalyst. It is cheap and abundant, nontoxic, and environmentally safe. However, it still suffers from logistical problems preventing its application in industry: namely, rapid electron-hole recombination and inability to utilize visible light. For nearly five decades researchers in this booming field have made numerous attempts to address these problems, doping and combining titanium dioxide with a wide range of materials. A novel ambient-temperature approach to synthesis and doping/modification of anatase-form titanium dioxide was attempted using both oxygen-rich and oxygen deprived synthetic routes. Reactants were exposed to various wavelengths of ultraviolet …

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Ionic Conductivity And Electrochemical Properties Of Alginate–Nn4no3-Based Biopolymer Electrolytes For Edlc Application, Norfatihah Binti Mazuki, Nur Muhitul Jalilah Rasali, Bouchta Sahraoui, Ahmad Salihin Samsudin Apr 2020

Ionic Conductivity And Electrochemical Properties Of Alginate–Nn4no3-Based Biopolymer Electrolytes For Edlc Application, Norfatihah Binti Mazuki, Nur Muhitul Jalilah Rasali, Bouchta Sahraoui, Ahmad Salihin Samsudin

Makara Journal of Technology

In this work, alginate doped with various contents of ammonium nitrate (NH4NO3) as a solid biopolymer electrolyte (SBE) was prepared via casting by using distilled water as a solvent. Impedance studies on alginate–NH4NO3 SBE films were conducted via impedance spectroscopy. The lowest bulk resistance (Rb) showed that the maximum ionic conductivity of the sample containing 25 wt.% NH4NO3 at ambient temperature (303 K) was 5.56 × 10−5 S cm−1. The temperature dependence of ionic conductivity was evaluated, and results confirmed that electrolytes followed an Arrhenius behavior. The highest conducting sample was fabricated into an electrical double-layer capacitor and characterized in …

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Current Status Of Hydrothermal Treatment For Energy And Material Recovery Toward A Sustainable Post-Consumer Material Cycle, Baskoro Lokahita, Muhammad Aziz, Fumitake Takahashi Apr 2020

Current Status Of Hydrothermal Treatment For Energy And Material Recovery Toward A Sustainable Post-Consumer Material Cycle, Baskoro Lokahita, Muhammad Aziz, Fumitake Takahashi

Makara Journal of Technology

The demand for energy-efficient and environmentally friendly municipal solid waste (MSW) processing has increased in developing countries. The thermochemical process offers a fast and reliable solution to reutilize or reduce the volume of MSW. Hydrothermal treatment is a novel MSW treatment technology that is compatible with high-moisture-content feedstock. It involves the thermal degradation of MSW in pressurized water or steam, which promotes the disintegration of cellulosic and polymer materials. Recent advances have shown effective MSW conversion into homogenous solid hydrochar with higher energy density. Alkali and chlorine content, which causes issues in combustors, was successfully removed due to the washing …

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Synthesis Of Sic Resin For 3d Printing Of Sic Ceramics By Digital Light Processing, Kevin Zhao, Bai Cui Apr 2020

Synthesis Of Sic Resin For 3d Printing Of Sic Ceramics By Digital Light Processing, Kevin Zhao, Bai Cui

UCARE: Research Products

Silicon carbide (SiC) resin is produced through shear mixing 0.1-1 μm SiC powders with Tethon’s high load Genesis resin base. Resins of varying SiC vol.% were synthesized to test the loading limit of the resin base; 10, 20, and 30 vol.% of SiC were made with the resin base handling the higher loads quite well. Several attempts were made at printing using the Tethon Bison 1000 DLP printer with higher loads of SiC showing better results even with lower intensity UV lights andtimes.

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Questaal: A Package Of Electronic Structure Methods Based On The Linear Muffin-Tin Orbital Technique, Dimitar Pashov, Swagata Acharya, Walter R.L. Lambrecht, Jerome Jackson, Kirill Belashchenko, Athanasios Chantis, Francois Jamet, Mark Van Schilfgaarde Apr 2020

Questaal: A Package Of Electronic Structure Methods Based On The Linear Muffin-Tin Orbital Technique, Dimitar Pashov, Swagata Acharya, Walter R.L. Lambrecht, Jerome Jackson, Kirill Belashchenko, Athanasios Chantis, Francois Jamet, Mark Van Schilfgaarde

Kirill Belashchenko Publications

This paper summarises the theory and functionality behind Questaal, an open-source suite of codes for calculating the electronic structure and related properties of materials from first principles. The formalism of the linearised muffin-tin orbital (LMTO) method is revisited in detail and developed further by the introduction of short-ranged tight-binding basis functions for full-potential calculations. The LMTO method is presented in both Green's function and wave function formulations for bulk and layered systems. The suite's full-potential LMTO code uses a sophisticated basis and augmentation method that allows an efficient and precise solution to the band problem at different levels of theory, …

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Estimation Of Lubrication Layer Thickness And Composition Through Reverse Engineering Of Interface Rheometry Tests, Alexis Salinas, Dimitri Feys Apr 2020

Estimation Of Lubrication Layer Thickness And Composition Through Reverse Engineering Of Interface Rheometry Tests, Alexis Salinas, Dimitri Feys

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

During concrete pumping, a lubrication layer is formed near the pipe wall. Extensive research has been performed on measuring and modeling the properties of this layer and using these values to predict pumping pressures. However, there are numerous discussions in the literature about the composition and thickness of this layer: can it be considered mortar, a micromortar, or is it cement paste? In this paper, possible solutions for the thickness and composition of the lubrication layer are derived from interface rheometry tests. It is assumed that the lubrication layer is composed of one or more concentric layers of paste or …

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Correction To: Recommendations Of Rilem Tc 260-Rsc For Using Superabsorbent Polymers (Sap) For Improving Freeze–Thaw Resistance Of Cement-Based Materials (Materials And Structures, (2019), 52, 4, (75), 10.1617/S11527-019-1375-4), Viktor Mechtcherine, Christof Schröfl, Michaela Reichardt, Agnieszka J. Klemm, Kamal Khayat Apr 2020

Correction To: Recommendations Of Rilem Tc 260-Rsc For Using Superabsorbent Polymers (Sap) For Improving Freeze–Thaw Resistance Of Cement-Based Materials (Materials And Structures, (2019), 52, 4, (75), 10.1617/S11527-019-1375-4), Viktor Mechtcherine, Christof Schröfl, Michaela Reichardt, Agnieszka J. Klemm, Kamal Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Agnieszka J. Klemm is affiliated to Glasgow Caledonian University, Glasgow, UK.

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Compaction And Residual Stress Modeling In Composite Manufactured With Automated Fiber Placement, Von Clyde Jamora Apr 2020

Compaction And Residual Stress Modeling In Composite Manufactured With Automated Fiber Placement, Von Clyde Jamora

Mechanical & Aerospace Engineering Theses & Dissertations

Automated fiber placement is a state-of-the-art manufacturing process that allows for complex layup patterns and can quickly place, cut, and restart composite tows. However, with this type of manufacturing process layup defects are inevitable, and manufacturing defects propagate after curing. Process modeling is the considered approach for exploring the defect prediction. Two different but related works were conducted, which are the thermochemical and hyperelastic model and the residual deformation model. For the model before cooling, a hyperelastic model and a thermo-chemical were made to simulate the compaction and heat transfer. Temperature dependent properties that are a function of degree of …

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Energy Conservation With Open Source Ad Blockers, Joshua M. Pearce Mar 2020

Energy Conservation With Open Source Ad Blockers, Joshua M. Pearce

Michigan Tech Publications, Part 1

Internet-related electricity consumption is rising rapidly as global Internet users spend more than 6.5 h per day online. Open source ad blockers have the potential to reduce the time and thus electricity spent using computers by eliminating ads during Internet browsing and video streaming. In this study, three open source ad blockers are tested against a no-ad blocker control. Page load time is recorded for browsing a representative selection of the globally most-accessed websites, and the time spent watching ads on videos is quantified for both trending and non-trending content. The results show that page load time dropped 11% with …

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Influence Of Glass Fiber Reinforced Polymer Wraps On Corrosion Progression Of Bridge Piles In Marine Environments, Shayan Yazdani Mar 2020

Influence Of Glass Fiber Reinforced Polymer Wraps On Corrosion Progression Of Bridge Piles In Marine Environments, Shayan Yazdani

USF Tampa Graduate Theses and Dissertations

The Friendship Trail Bridge connecting Tampa to St. Petersburg was demolished in 2016. Thirteen 20 inches. by 20 inches. reinforced concrete piles supporting its superstructure were part of research studies conducted between 2004 and 2008 to explore the role of glass fiber reinforced polymers (GFRP) in corrosion repair. During demolition, piles were typically cut at the pile cap and in the splash zone. The resulting segments varied in length between 3 to 4 ft. These remnants were transported to the University of South Florida (USF) campus for postmortem analysis. The overarching goal was to establish the role of GFRP in …

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Dynamic Micromechanical Fabry-Perot Cavity Sensors Fabricated By Multiphoton Absorption Onto Optical Fiber Tips, Jeremiah C. Williams Mar 2020

Dynamic Micromechanical Fabry-Perot Cavity Sensors Fabricated By Multiphoton Absorption Onto Optical Fiber Tips, Jeremiah C. Williams

Theses and Dissertations

This research leveraged two-photon polymerization microfabrication to integrate dynamic mechanical components with Fabry-Perot resonators onto the ends of low-loss optical fibers to prototype 3 micro-optic devices. The first device featured a multi-positional mirror that enabled thin-film deposition onto cavities of any length with mirrors of significant curvature, for refractive index sensing. The second device combined an FP cavity with a spring body featuring easily scalable stiffness for pressure sensing. The third device presented a high-speed rotating micro-anemometer for measuring a wide range of gas flows. All devices represent a significant reduction in size and weight over commercially available devices.

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Wideband Metasurface Antenna, Thomas A. Lepley Mar 2020

Wideband Metasurface Antenna, Thomas A. Lepley

Theses and Dissertations

This effort explored design of metasurface antennas and evaluated their suitability for ultra-wideband applications (2 to 18 GHz). Six unit cell types were characterized. Eigenmode simulations produced frequency vs. phase data for the unit cells, from which impedance vs. gap size data was computed. A holographic design equation was used to generate the metasurface antenna designs. The unit cell simulations revealed that the assumption of single mode operation is a constraint for wideband designs. An 8" by 8" metasurface antenna with a Rogers 3010 dielectric and a design frequency of 10 GHz was fabricated and tested. It had a 1.5:1 …

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Alternate Materials For High-Speed Projectile Casing, Andrew W. Beard Mar 2020

Alternate Materials For High-Speed Projectile Casing, Andrew W. Beard

Theses and Dissertations

A high-speed projectile impact is a highly complex dynamic problem that can be simplified with the use of finite element analysis solvers. Abaqus/Explicit was used to evaluate the impact of various projectiles using a plane strain setup. Using a baseline stainless steel projectile, the proposed sandwich construction design was analyzed and compared to the baseline projectile. The overall goal was to see if a new composite casing could perform similarly to the simple baseline projectile. The sandwich construction used stainless steel, tungsten, and silicon-carbide reinforce aluminum as outer and inner shell materials. The core material was created using additive manufacturing …

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Investigation Of Ultem 9085 For Use In Printed Orbital Structures, William R. Gallagher Mar 2020

Investigation Of Ultem 9085 For Use In Printed Orbital Structures, William R. Gallagher

Theses and Dissertations

Additive manufacturing is revolutionizing industries ranging from medicine to space. However, the structural characteristics of plastic parts created by these methods are not as well understood as their more established counterparts. This research explored two relevant areas: how the structural characteristics of ULTEM 9085 plastic behaved after exposure to orbital conditions and the design of the cross-sectional area of a beam to be 3-D printed in microgravity based on the expected loads from the printer. To study orbital effects, ULTEM 9085 was printed into 1/4th scale ASTM D638- 14 dogbones using a Stratasys 450mc printer. These dogbones were placed in …

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Structural And Electronic Properties Of The Pure And Stable Elemental 3d Topological Dirac Semimetal Α-Sn, Maya N. Nair, Ivan Madarevic, Umamahesh Thupakula, Gertjan Lippertz, Niels Claessens, Pin-Cheng Lin, Harsh Bana, Sara Gonzalez, Giovanni Di Santo, Luca Petaccia, Lino M.C. Pereira, Chris Van Haesendonck, Margriet J. Van Bael Mar 2020

Structural And Electronic Properties Of The Pure And Stable Elemental 3d Topological Dirac Semimetal Α-Sn, Maya N. Nair, Ivan Madarevic, Umamahesh Thupakula, Gertjan Lippertz, Niels Claessens, Pin-Cheng Lin, Harsh Bana, Sara Gonzalez, Giovanni Di Santo, Luca Petaccia, Lino M.C. Pereira, Chris Van Haesendonck, Margriet J. Van Bael

Advanced Science Research Center

In-plane compressively strained α-Sn films have been theoretically predicted and experimentally proven to possess non-trivial electronic states of a 3D topological Dirac semimetal. The robustness of these states typically strongly depends on purity, homogeneity, and stability of the grown material itself. By developing a reliable fabrication process, we were able to grow pure strained α-Sn films on InSb(100), without heating the substrate during growth nor using any dopants. The α-Sn films were grown by molecular beam epitaxy, followed by experimental verification of the achieved chemical purity and structural properties of the film’s surface. Local insight into the surface morphology was …

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Cyclic Regeneration Of Nanostructured Composites For Catalytic Applications, Fatih Dogan Mar 2020

Cyclic Regeneration Of Nanostructured Composites For Catalytic Applications, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

A cermet catalyst material, defining a matrix having interconnected open pores, the matrix selected from the group consisting of YSZ and CGO and defining a substrate, a ceramic coating having a general formula AyBnOx at least partially coating the pores, and a plurality of metal particles A at least partially embedded in the ceramic coating. A is selected from the group consisting of Co, Cu, Ce, Ni, Ti, and combinations thereof and B is selected from the group consisting of Mo, W, Ce, and combinations thereof. When the coating is in a first oxidizing atmosphere …

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A Novel Self-Healing System: Towards A Sustainable Porous Asphalt, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen Mar 2020

A Novel Self-Healing System: Towards A Sustainable Porous Asphalt, Shi Xu, Xueyan Liu, Amir Tabakovic, Erik Schlangen

Articles

Self-healing asphalt, aimed to produce a sustainable asphalt pavement using green technology, has been studied in the past two decades. Technologies including encapsulated rejuvenator and induction heating have been proposed, demonstrated in the laboratory, and gradually evaluated in field application. This paper looks into the synergy effect of the above two technologies, where induction heating serves as the asphalt damage repair mechanism, requiring just 2 min heating time and encapsulated rejuvenator will replenish (rejuvenate) aged asphalt binder and reinstate bitumen’s healing ability. Moreover, the increased temperature from induction heating could in turn accelerate the diffusion process of rejuvenator into aged …

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Characterization Of A Sagnac Loop Mirror-Based Hybrid Passive Variable Optical Coupler/Attenuator, Simeon Bikorimana, Muhammad A. Ummy, Abdullah Hossain, Richard Lin, Roger Dorsinville Mar 2020

Characterization Of A Sagnac Loop Mirror-Based Hybrid Passive Variable Optical Coupler/Attenuator, Simeon Bikorimana, Muhammad A. Ummy, Abdullah Hossain, Richard Lin, Roger Dorsinville

Publications and Research

The implementation and performance of a unidirectional all-single mode fiber hybrid passive variable optical coupler/attenuator based on a Sagnac loop mirror with a continuous variable coupling ratio using off-the-shelf optical sub-components are discussed. Parameters of two output ports of the unidirectional hybrid passive variable optical coupler/attenuator, such as maximum coupling ratio, insertion loss, excess loss, and wavelength-dependent return loss over the C-band at room temperature are reported. The reflectivity of the Sagnac loop mirror continuously varies from 0.1% to 99.9% by adjusting retarders of a polarization controller. The 3-dB coupling ratio (i.e., 50:50) between the two output ports of the …

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Selection Of Blowing Agent For Metal Foam Production: A Review, Ankur Bisht, Brijesh Gangil, Vinay Kumar Patel Mar 2020

Selection Of Blowing Agent For Metal Foam Production: A Review, Ankur Bisht, Brijesh Gangil, Vinay Kumar Patel

Journal of Metals, Materials and Minerals

Metal foams are cellular solids in which gas is uniformly distributed throughout the metal matrix. One of the cheapest ways of evolving the gas is introducing the blowing agent in parent metal in liquid state. A blowing agent is defined as a material that decomposes under the presence of heat and releases gas which then propels the foaming process. The quality of final foam is influenced by several parameters such as composition, size and volume fraction of the blowing agent used. Different chemicals which can evolve gases such as carbonates and metal hydrides fit into the description of blowing agent. …

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An Approach To Search The Potentiality Of Node In Bamboo Strip Reinforced Composites, Mohammad Irfan Iqbal, Rashed Al Mizan, Ayub Nabi Khan Mar 2020

An Approach To Search The Potentiality Of Node In Bamboo Strip Reinforced Composites, Mohammad Irfan Iqbal, Rashed Al Mizan, Ayub Nabi Khan

Journal of Metals, Materials and Minerals

Bamboo has recently entered the composite sector with some attractive labels such as 'green'. The current commercial manufacturing method of bamboo composite removes the node's portion of bamboo culm during bamboo processing. This method generates a high amount of solid waste materials along with processing complexity and the scientific merit of this practice is also questionable. This research investigates the effects of culm nodes on bamboo based composite properties. In this study an approach to produce bamboo strips reinforced epoxy composites and their mechanical properties (e.g. tensile, flexural and impact properties) were reported. It was demonstrated that mechanical properties of …

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Preparation And Characterization Of Lake Pigments From Sappan Wood Using Thai Local Clays, Jitnapa Sirirak, Nattawan Worawannotai, Cheewita Suwanchawalit, Supanee Chayabutra Mar 2020

Preparation And Characterization Of Lake Pigments From Sappan Wood Using Thai Local Clays, Jitnapa Sirirak, Nattawan Worawannotai, Cheewita Suwanchawalit, Supanee Chayabutra

Journal of Metals, Materials and Minerals

Thai local clays: Munpoo clay (MC) and Dindang clay (DC) were utilized as the adsorbents for preparation of the lake pigments from sappan wood. The lake pigment which was prepared by using MC as the adsorbent (L-MC) appeared reddish-brown while a deeper reddish-brown color of the lake pigment (L-DC) was obtained by using DC as the adsorbent. Characterization of MC, DC, L-MC, and L-DC was accomplished by XRD, SEM, FT-IR, BET, TGA and UV-Vis DRS. The effects of adsorbent dosage, pH of sappan wood extract and time on the adsorption were also investigated. The results revealed that silicon oxide and …

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Poly(Ester Urethane)-Crosslinked Carboxymethylchitosan As A Highly Water Swollen Hydrogel, Nunthiya Deepuppha, Apiwat Kadnaim, Boonjira Rutnakornpituk, Metha Rutnakornpituk Mar 2020

Poly(Ester Urethane)-Crosslinked Carboxymethylchitosan As A Highly Water Swollen Hydrogel, Nunthiya Deepuppha, Apiwat Kadnaim, Boonjira Rutnakornpituk, Metha Rutnakornpituk

Journal of Metals, Materials and Minerals

This work focused on the synthesis and characterization of carboxymethylchitosan (CMC)-based hydrogels modified with polyester-containing polyurethane (PU). The polyester was first synthesized from the condensation between 1,6-hexane diol and malonic acid, then reacted with an excess of 1,6-hexamethylene diisocyanate (HDI), and followed by the reaction with ethylene glycol as a chain extender to gain PU. CMC was chemically crosslinked with a water soluble crosslinker in the presence of 1-60 wt% of PU to obtain highly water swollen CMC hydrogels. Upon addition of PU, the CMC hydrogel showed excellent water swellability (up to 400 times of the dried weight), and it …

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The Luminescence, Optical, And Structural Properties Of Srmoo4:Ce3+ Phosphor For Photonics Material Applications, Eakgapon Kaewnuam, Nuanthip Wantana, Sasithorn Saikaew, Jakrapong Kaewkhao Mar 2020

The Luminescence, Optical, And Structural Properties Of Srmoo4:Ce3+ Phosphor For Photonics Material Applications, Eakgapon Kaewnuam, Nuanthip Wantana, Sasithorn Saikaew, Jakrapong Kaewkhao

Journal of Metals, Materials and Minerals

SrMoO4:Ce3+ phosphors with different Ce2O3 concentration were studied in the structure, optical and luminescence properties. The phosphor powders were synthesized by a solid-state reaction to investigate with the XRD, FTIR, absorption and emission spectra measurement. The XRD patterns confirm the tetragonal crystalline structure of SrMoO4 host composition. The FTIR spectra show the dominant vibrations of tetrahedral [MoO4]2- unit in powders. These phosphors absorb photons in the range of ultraviolet and visible light proved by the absorption spectra. The emission spectra represent the strongest emission at 421 nm wavelength of phosphors under 266 nm excitation. This emission occurred under the transition …

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Defects Of The Steel Billet In Continuous Casting, Anh-Hoa Bui, Van-Hung Nguyen Mar 2020

Defects Of The Steel Billet In Continuous Casting, Anh-Hoa Bui, Van-Hung Nguyen

Journal of Metals, Materials and Minerals

In continuous casting process, defects of the steel billet (e.g. crack, pinhole, blowhole, central shrinkage, slag entrapment and appearance deviation, etc.) negatively affect the quality and the yield of rolled products. This research has been carried out to investigate some defects which often occurred in Vietnamese steel plants. The experimental work was conducted in an industrial 4-strands continuous casting machine with the billet's cross-section of 130×130 mm2 . The position, generating cause identification of these defects and proper measures have been discussed. A change in the steel compositions and the water distribution during secondary cooling was applied to improve the …

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Sm3+ Ions Doped Zinc Barium Tellurite Oxyfluoride Glasses For Laser Materials, Yaowalak Yamsuk, Patarawagee Yasaka, Jakrapong Kaewkhao, Narong Sangwaranatee Mar 2020

Sm3+ Ions Doped Zinc Barium Tellurite Oxyfluoride Glasses For Laser Materials, Yaowalak Yamsuk, Patarawagee Yasaka, Jakrapong Kaewkhao, Narong Sangwaranatee

Journal of Metals, Materials and Minerals

The Sm3+ ions were doped tellurite glasses with composition (55-x) TeO2-10ZnF2- 35BaO-xSm2O3 (where x = 0.00, 0.05, 0.10, 0.50, 1.00 and 1.50 in mol%) to investigate the physical, the optical, the luminescence and structural properties. The functional groups can be identified using FT-IR spectra of Sm3+ in the glasses. The most intense peak from emission spectra is at 600 nm (4G5/26H7/2) corresponding to reddish-orange color. The oscillator strengths were resolved from the absorption spectra and then used to calculate the Judd - Ofelt (J - O) intensity parameters. The radiative properties were calculated by J - O intensity parameters for …

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The Water Permeability Properties Of Re-Vibrated Lightweight Concrete, Muayad Mohammed Kassim Mar 2020

The Water Permeability Properties Of Re-Vibrated Lightweight Concrete, Muayad Mohammed Kassim

Journal of Metals, Materials and Minerals

Re-vibration of sequential layers of relatively deep structural members after a particular time harms the strength and water permeability properties of the concrete. The harmful effects can be observed in lightweight concrete due to the floating tendency of lightweight aggregate. In this experimental study, the influence of adding retarder plasticizer and silica fume on water permeability properties of re-vibrated lightweight concrete was investigated. The effects of re-vibration at different time lags on compressive strength and permeable voids ratio were studied. Absorption, sorptivity, and water penetration depth under pressure were also studied. Results show that the addition of a retarder increased …

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Physical Property And Compressive Strength Of Fired Clay Bricks Incorporated With Paper Waste, Anuwat Srisuwan, Nonthaphong Phonphuak Mar 2020

Physical Property And Compressive Strength Of Fired Clay Bricks Incorporated With Paper Waste, Anuwat Srisuwan, Nonthaphong Phonphuak

Journal of Metals, Materials and Minerals

This research is intended to evaluate the effects of paper waste addition on the physical properties and strength of fired clay bricks. Paper waste was mixed with clay in the ratios of 2.5, 5.0, 7.5 and 10 wt%. Green bricks were fired with different variations of temperature from 900-1100C for1 h in air. Fired bricks were then analyzed for physical and mechanical properties. Porosity was increased with higher paper waste content. An increase in porosity relatedly created lower density and higher shrinkage values. Additionally, porous content in fired clay bricks correlated to the deterioration of the compressive strength, due to …

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Structural Studies Of Natural Zeolites And Optimizations For Water Hardness Softening Media, Tesfamariam Teklu Gebretsadik, Teklit Kidane Gebremedhin Mar 2020

Structural Studies Of Natural Zeolites And Optimizations For Water Hardness Softening Media, Tesfamariam Teklu Gebretsadik, Teklit Kidane Gebremedhin

Journal of Metals, Materials and Minerals

This study was aimed at investigating the mineralogical composition and structural features of natural zeolites using XRF, XRD, TGA, FT-IR and SEM. Natural zeolites were subjected to acid-activation and subsequently with NaCl salt to enhance surface area for water hardness softening applications. Peaks around 3560 and 1650 cm-1 belongs to O - H stretching and O - H bending vibrations which confirmed the presence of moisture within zeolite structures. This result was further supported by evolution of moisture above 108°C from thermogravimetric analysis. Fibrous structures which are full of rough texture were examined by SEM. The XRD pattern confirmed Stellerite …

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