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Articles 1831 - 1860 of 3655
Full-Text Articles in Engineering
Synthesis And Characterization Of Ball-Milled Eggshell And Al2o3 Reinforced Hybrid Green Composite Material, Shrawan Kumar, Shashi Prakash Dwivedi, Vijay Kumar Dwived
Synthesis And Characterization Of Ball-Milled Eggshell And Al2o3 Reinforced Hybrid Green Composite Material, Shrawan Kumar, Shashi Prakash Dwivedi, Vijay Kumar Dwived
Journal of Metals, Materials and Minerals
Eggshell is a by-product (a secondary product derived from a production process) which produces lots of environment pollution. However, some environment pollution can be reduced by utilizing this waste. In the present investigation, an attempt was made to utilize eggshell as the reinforcement material with alumina (Al2O3) in the development of composite material. Carbonized eggshell particles and Al2O3 ceramic particles were ball-milled up to 100 hours to obtain a uniform particle size of reinforcement particles. Results showed that by using Al2O3 with eggshell in the development of aluminium based composite material after the ball-milling, mechanical properties were significantly improved. However, …
Production Of Silica-Based Ceramics Sintered Under Nitrogen Atmosphere From Rice Husk And Sugarcane Bagasse Ash, Wiphawan Khopthong, Benya Cherdhirunkorn
Production Of Silica-Based Ceramics Sintered Under Nitrogen Atmosphere From Rice Husk And Sugarcane Bagasse Ash, Wiphawan Khopthong, Benya Cherdhirunkorn
Journal of Metals, Materials and Minerals
Nitride silica-based ceramics were prepared by sintering under nitrogen atmosphere using rice husk ash and bagasse ash as raw materials. X-ray Fluorescence Spectrometry (XRF) and X-ray Diffractometor (XRD) studies revealed that the main phase of rice husk ash (after calcined at 600C for 6 h.) was amorphous silica, whereas the sugarcane bagasse ash contained quartz and CaCO3. Thus, both ashes would be a good source for silica. Two batches of the 100 wt% rice husk ash (RHA100) and the mixture of 50 wt% rice husk ash and 50 wt% bagasse ash (RHA50BA50) were wet milled using planetary ball milling machine, …
Green-Based Corrosion Protection For Mild Steel In 3.5% Nacl And Distilled Water Medias: Jatropha Curcas And Roselle Extracts, Muhammad A. Afandi, Safaa N. Saud, Esah Hamzah
Green-Based Corrosion Protection For Mild Steel In 3.5% Nacl And Distilled Water Medias: Jatropha Curcas And Roselle Extracts, Muhammad A. Afandi, Safaa N. Saud, Esah Hamzah
Journal of Metals, Materials and Minerals
In this study, the natural sources of Jatropha curcas and Hibiscus Sabdariffa calynx (Roselle) extracts as green corrosion inhibitors were employed to improve the corrosion resistance of mild steel in simulated (3.5% NaCl) and distilled water medias. The inhibiting performance of two types of extracts was studied by visual inspection, microscope analysis, and various electrochemical measurements and the data of corrosion rate were statistically analyzed. The main phenolic compounds of Jatropha and Roselle extracts were confirmed via a liquid chromatography-mass spectrometry. Meanwhile, the functional groups of active phytochemical compounds were characterized via attenuated total reflection spectroscopy (ATR). The results of …
Properties Of Wood-Plastic Composites Based On Pvc/Pla/Pbat Ternary Blend, Laksamon Raksaksri, Phasawat Chaiwutthinan, Amnouy Larpkasemsuk, Saowaroj Chuayjuljit, Anyaporn Boonmahitthisud
Properties Of Wood-Plastic Composites Based On Pvc/Pla/Pbat Ternary Blend, Laksamon Raksaksri, Phasawat Chaiwutthinan, Amnouy Larpkasemsuk, Saowaroj Chuayjuljit, Anyaporn Boonmahitthisud
Journal of Metals, Materials and Minerals
The objective of this work was to improve mechanical properties, thermal resistance, and biodegradability of poly(vinyl chloride) (PVC) by the addition of poly(lactic acid) (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and wood flour (WF). The samples made from a mixture of PVC/PBAT exhibited the highest impact and tensile properties, while properties of the samples made from PVC/PLA had the highest flexural and thermal properties, PVC/PLA/PBAT mixed samples exhibited average mechanical properties. The addition of WF to all the blends increased impact strength, flexural properties, Young's modulus, thermal resistance, and biodegradability of the samples in comparison to those of the neat PVC and …
Synthesis Of Hydroxyapatite From Cuttlebone Under Various Ph Conditions: An Approach For Medical Materials, Sineenart Kangkan, Premjit Arpornmaeklong, Sarute Ummartyotin
Synthesis Of Hydroxyapatite From Cuttlebone Under Various Ph Conditions: An Approach For Medical Materials, Sineenart Kangkan, Premjit Arpornmaeklong, Sarute Ummartyotin
Journal of Metals, Materials and Minerals
To support the bio-based economy, development on hydroxyapatite from cuttlebone was investigated. Cuttlebone is naturally occurring source of calcium. We calcined it at 700°C for 4 h to form a calcium oxide powder. Hydroxyapatite was coprecipitated with calcium oxide powder and phosphoric acid. The effect of the pH ranging from 6 - 10 was controlled by adding ammonium hydroxide. Fourier transform infrared and X-ray diffraction were employed to characterize the structural properties of the hydroxyapatite. Changes in pH did not affect the structural properties of the hydroxyapatite. Thermogravimetric analysis revealed that the hydroxyapatite was thermally stable up to 700°C. At …
Xas Analysis Of Copper Binding In Soils, Wapakorn Siriwong, Penphitcha Amonpattaratkit, Wantana Klysubun
Xas Analysis Of Copper Binding In Soils, Wapakorn Siriwong, Penphitcha Amonpattaratkit, Wantana Klysubun
Journal of Metals, Materials and Minerals
Ecological distribution of copper from soil is depended on its bioavailability and mobility. Copper binding on heterogeneous soil composition is a key information for understanding the long-term fate benefiting suitable management practice for copper in the environment. X-ray absorption spectroscopy (XAS) techniques were used to provide microscopic scale information of copper-binding on different soils. Soil samples containing 14.9-56.6% clay and 0.5-3.4% organic matter were studied. Dry-powder soil samples containing approximated 0.3% copper from batch equilibrated equilibrium experiments were analyzed. Copper K-edge spectrum were collected at the Synchrotron light research institute (SLRI), Thailand in X-ray absorption near edge structure (XANES) and …
Preparation Of Alginate/2-Hydroxyethyl Methacrylate Composite Beads: Role Of Fillers And Characteristics Of Bead Formation, Somkiet Urusetthanon, Somchai Udon, Boonsri Kusuktham
Preparation Of Alginate/2-Hydroxyethyl Methacrylate Composite Beads: Role Of Fillers And Characteristics Of Bead Formation, Somkiet Urusetthanon, Somchai Udon, Boonsri Kusuktham
Journal of Metals, Materials and Minerals
In this research, alginate composite beads were prepared. The objective was to study the effect of particle size of fillers on the viscosity of alginate solution and bead formation. The sodium alginate solution with and without 2-hydroxyethyl methacrylate was dropped into calcium chloride to form the beads. The polymerization of the 2-hydroxyethyl methacrylate in the alginate matrix was occurred by using potassium persulphate as an initiator and N,N/-methylenebisacrylamide as a crosslinking agent and N,N,N/,N/ -tetramethylethylenediamine in the calcium chloride solution as an accelerator. For the preparation of the composite beads, the cotton dust, and sawdust at various ratios were mixed …
Effect Of Polystyrene Molecular Weight And Zinc Oxide Concentration On Dewetting Behavior Of Polymeric Thin Films, Kattaleeya Sujaroon, Phanawan Whangdee, Nampueng Pangpaiboon
Effect Of Polystyrene Molecular Weight And Zinc Oxide Concentration On Dewetting Behavior Of Polymeric Thin Films, Kattaleeya Sujaroon, Phanawan Whangdee, Nampueng Pangpaiboon
Journal of Metals, Materials and Minerals
The separation between ultra-thin polymer film on metal oxide substrate is called dewetting. Dewetting causes the polymer films to loss their stability and other important properties, for example, the films may short circuit or reduce their transparency. Therefore, the stability of polymer thin films on substrate need to be improved. Addition of nanoparticles is one of the most popular technique used to increase the stability of polymer thin films. The correlation between the different of molecular weight and ZnO concentration on dewetting behavior was studied in this research. The appropriate concentration of ZnO on dewetting suppression in each molecular weight …
Effects Of Sodium Silicate As Liquid Phase Sintering Additives On Properties Of Alumina Ceramics, Kanyapak Siriphaisarntavee, Charusporn Mongkolkachit, Mateekul Jiarawattananon, Karn Serivalsatit, Thanakorn Wasanapiarnpong
Effects Of Sodium Silicate As Liquid Phase Sintering Additives On Properties Of Alumina Ceramics, Kanyapak Siriphaisarntavee, Charusporn Mongkolkachit, Mateekul Jiarawattananon, Karn Serivalsatit, Thanakorn Wasanapiarnpong
Journal of Metals, Materials and Minerals
This research focused on the production of high-performance alumina products. The feasibility of using soluble alkali silicate in liquid phase sintering of alumina was studied. Liquid soluble alkali silicate was used to enhance the plastic forming of alumina and formed liquid phase sintering to attain fired alumina products with high strength, high alumina content and low water absorption. The methodology consisted of the mixing of organic binder with sodium silicate (Na2SiO3), used as liquid phase sintering additive, of 0-15 wt%. Magnesium carbonate (MgCO3), used as the grain growth inhibitor, of 0-1 wt% were added and followed by alumina powders. The …
Synthesis And Fabrication Of Polyaniline/Eggshell Composite In Ammonia Detection, Nurul Aqilla Mazlan, Jamil M. Sapari, Kavirajaa Pandian Sambasevam
Synthesis And Fabrication Of Polyaniline/Eggshell Composite In Ammonia Detection, Nurul Aqilla Mazlan, Jamil M. Sapari, Kavirajaa Pandian Sambasevam
Journal of Metals, Materials and Minerals
This study focuses on the measurement and performance of bio-filler composite based on polyaniline (PANI)/chicken eggshell (CES). The composite films were prepared via ex-situ polymerisation using DBSA as its dopant. The PANI solution was distributed equally before mixing it with three different ratios of CES powder. Characterisations of the composite films were analysed using Fourier-transform infrared spectroscopy (FTIR) and Ultraviolet-visible spectroscopy (UV-Vis), Scanning electron microscope/energy dispersive x-ray (SEM/EDX) and multimeter. PANI film that contained 20mg CES filler possessed the highest conductivity and the fastest time to achieve 90% of sensitivity. The film was also very selective towards ammonia gas and …
Tribology, Mechanical Properties And Coloration Of A Mica Glass-Ceramic, Sahadsaya Prasertwong, Sukanda Angkulpipat, Thapanee Srichumpong, Kallaya Suputtamongkol, Chanchana Thanachayanont, Ramona Sola4, Greg Heness, Cristina Leonelli, Duangrudee Chaysuwan
Tribology, Mechanical Properties And Coloration Of A Mica Glass-Ceramic, Sahadsaya Prasertwong, Sukanda Angkulpipat, Thapanee Srichumpong, Kallaya Suputtamongkol, Chanchana Thanachayanont, Ramona Sola4, Greg Heness, Cristina Leonelli, Duangrudee Chaysuwan
Journal of Metals, Materials and Minerals
The research employed pigments, Fe2O3 and CeO2, into the glass frit for adjustable mechanical properties and coloration. Disc samples were prepared to determine microstructures and mechanical properties in terms of tribology and nano-indentation hardness as well as biaxial flexural strength. The glass system presented the crystalline phases, by XRD, of phlogopite Ca-mica, fluorapatite, stishovite, anorthite and strontium apatite. Furthermore, SEM micrographs revealed rod-like microstructures and parent glass phase in all specimens 1) GC, 2) GC + 1wt% CeO2, 3) GC + 0.1wt% Fe2O3 and 4) GC + 1wt% CeO2 + 0.1wt% Fe2O3. For the tribology test, specimens were tested by …
Dry-Sliding Wear Of The 316l/H-Bn Composites Produced Under Crack Ammonia Atmosphere, Ekkarat Chusong, Panya Kansuwan, Naoto Ohtake, Pongsak Wila, Nattaya Tosangthum, Ruangdaj Tongsri
Dry-Sliding Wear Of The 316l/H-Bn Composites Produced Under Crack Ammonia Atmosphere, Ekkarat Chusong, Panya Kansuwan, Naoto Ohtake, Pongsak Wila, Nattaya Tosangthum, Ruangdaj Tongsri
Journal of Metals, Materials and Minerals
Wear is one of different problems in mechanical failures of moving components. When a component encounters friction force on its surface, crack initiation tends to occur and wear follows crack propagation. Thus, the moving parts of automobiles should have proper wear resistance for long-time services, in addition to having high strength and hardness for heavy load operation. A self-lubricating material with compromised tribological and mechanical properties is important for some moving components. In this work, self-lubricating composites, metal matrix composites embedded with a solid lubricant, made from 316L stainless steel powder mixed with different hexagonal boron nitride (h-BN) contents of …
Selection Of Blowing Agent For Metal Foam Production: A Review, Ankur Bisht, Brijesh Gangil, Vinay Kumar Patel
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. …
An Approach To Search The Potentiality Of Node In Bamboo Strip Reinforced Composites, Mohammad Irfan Iqbal, Rashed Al Mizan, Ayub Nabi Khan
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 …
Preparation And Characterization Of Lake Pigments From Sappan Wood Using Thai Local Clays, Jitnapa Sirirak, Nattawan Worawannotai, Cheewita Suwanchawalit, Supanee Chayabutra
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 …
Poly(Ester Urethane)-Crosslinked Carboxymethylchitosan As A Highly Water Swollen Hydrogel, Nunthiya Deepuppha, Apiwat Kadnaim, Boonjira Rutnakornpituk, Metha Rutnakornpituk
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 …
The Luminescence, Optical, And Structural Properties Of Srmoo4:Ce3+ Phosphor For Photonics Material Applications, Eakgapon Kaewnuam, Nuanthip Wantana, Sasithorn Saikaew, Jakrapong Kaewkhao
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 …
Defects Of The Steel Billet In Continuous Casting, Anh-Hoa Bui, Van-Hung Nguyen
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 …
Sm3+ Ions Doped Zinc Barium Tellurite Oxyfluoride Glasses For Laser Materials, Yaowalak Yamsuk, Patarawagee Yasaka, Jakrapong Kaewkhao, Narong Sangwaranatee
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 (4G5/26H7/2) 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 …
The Water Permeability Properties Of Re-Vibrated Lightweight Concrete, Muayad Mohammed Kassim
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 …
Physical Property And Compressive Strength Of Fired Clay Bricks Incorporated With Paper Waste, Anuwat Srisuwan, Nonthaphong Phonphuak
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 900-1100C 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 …
Structural Studies Of Natural Zeolites And Optimizations For Water Hardness Softening Media, Tesfamariam Teklu Gebretsadik, Teklit Kidane Gebremedhin
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 …
Development Of Sr/Cao Catalyst Derived From Cuttlebone (Sepia Officinalis) For Biodiesel Production, Napat Tomano, Apisit Prokaew, Supakorn Boonyuen, Sarute Ummartyotin
Development Of Sr/Cao Catalyst Derived From Cuttlebone (Sepia Officinalis) For Biodiesel Production, Napat Tomano, Apisit Prokaew, Supakorn Boonyuen, Sarute Ummartyotin
Journal of Metals, Materials and Minerals
Cuttlebone (Sepia officinalis) was used as a source of calcium oxide for biodiesel catalyst. The objective of this work is to present the bio-based catalyst prepared from cuttlebone. 1, 3, 5 and 10 %wt of strontium was loaded into calcium oxide powder derived from cuttlebone. Structural properties of Sr/CaO catalyst were evaluated by Fourier transform infrared and X-ray diffraction, respectively. There is no change on morphological properties of catalyst between Sr/CaO and pristine CaO. The homogeneous distribution of strontium was confirmed by EDX mapping technique. The specific surface area of powder was estimated to be 10-30 m2 ·g-1. The thermal …
Investigation Of Crosslink Structure Of Natural Rubber During Vulcanization Using X-Ray Absorption Near Edge Spectroscopy, Kanoktip Boonkerd, Wanwisa Limphirat
Investigation Of Crosslink Structure Of Natural Rubber During Vulcanization Using X-Ray Absorption Near Edge Spectroscopy, Kanoktip Boonkerd, Wanwisa Limphirat
Journal of Metals, Materials and Minerals
The X-ray absorption near edge spectroscopy technique (XANES) has been applied to determine the crosslinking structure of natural rubber (NR) during sulfur vulcanization process. The NR samples were prepared using DCBS as an accelerator at different sulfur to DCBS ratios (from 0.26 to 6.67). The results showed that with increasing cure time from tc50 to tc70, tc90 and tc100 the position of sulfur peak shifted to higher energy. This implied that the amount of polysulfidic crosslink gradually decreased with increasing cure time. This result supported the crosslinking mechanism proposed in the literature at which the polysulfidic crosslink is dominating at …
Influence Of Poly(Butylene Terephthalate) And Wollastonite On Properties Of Recycled Poly(Ethylene Terephthalate) Preforms, Phasawat Chaiwutthinan, Thaksaporn Riyaphan, Athapon Simpraditpan, Amnouy Larpkasemsuk
Influence Of Poly(Butylene Terephthalate) And Wollastonite On Properties Of Recycled Poly(Ethylene Terephthalate) Preforms, Phasawat Chaiwutthinan, Thaksaporn Riyaphan, Athapon Simpraditpan, Amnouy Larpkasemsuk
Journal of Metals, Materials and Minerals
Influence of poly(butylene terephthalate) (PBT) and wollastonite (WLN) on properties of recycled poly(ethylene terephthalate) (RPET) was investigated. RPET was first melt-mixed with PBT at five loadings (10-50 wt%) on a twin screw extruder, and then injection molded. Scanning electron micrographs showed the immiscible blends. The blends at 10-40 wt% PBT displayed droplet-matrix morphology, while the blend at 50 wt% PBT showed a matrix inversion. All blends showed a PBT-dosedependent increase in impact strength and Young's modulus with an expense of tensile strength and elongation at break. Among five RPET/PBT blends, the one at 40 wt% PBT exhibited the good balanced …
On The Corrosion Behaviour Of As-Cast And Heat-Treated Mg-Re Alloys In 0.9% Nacl Solution, Abdelkader Hanna, Lyacine Rabahi, Mohamed Amine Soualili, Achour Dakhouche, Djamel Bradai, Hiba Azzeddine
On The Corrosion Behaviour Of As-Cast And Heat-Treated Mg-Re Alloys In 0.9% Nacl Solution, Abdelkader Hanna, Lyacine Rabahi, Mohamed Amine Soualili, Achour Dakhouche, Djamel Bradai, Hiba Azzeddine
Journal of Metals, Materials and Minerals
The microstructure and corrosion behaviour of as-cast and heat-treated Mg-1.44Nd and Mg-1.43Ce (wt.%) alloys in 0.9% NaCl (wt.%) solution were investigated using electrochemical tests, X-ray diffraction (XRD) and scanning electron microscopy, combined with energy-dispersive X-ray spectroscopy (SEM-EDS). The as-cast microstructure of both alloys revealed the presence of second phases. Heat treatment at 535°C for 6 h led to a more uniform distribution of the second phases in Mg-1.44Nd alloy and their dissolution along the grains boundaries in the Mg-1.43Ce alloy. As a result, the corrosion resistance was improved in the heat-treated alloys. Accordingly, the corrosion resistance values for the heat-treated …
Numerical Modeling Of Longwall Top Coal Caving Method At Thar Coalfield, Niaz Muhammad Shahani, Zhijun Wan, Xigui Zheng, Li Guichen, Cancan Liu, Fahad Irfan Siddiqui, Gu Bin
Numerical Modeling Of Longwall Top Coal Caving Method At Thar Coalfield, Niaz Muhammad Shahani, Zhijun Wan, Xigui Zheng, Li Guichen, Cancan Liu, Fahad Irfan Siddiqui, Gu Bin
Journal of Metals, Materials and Minerals
Thar Coalfield in Pakistan is the largest reserve of lignite coal in the country, which is outlined by thick coal seams. The preferred mining method for these thick coal seams is the Longwall Top Coal Caving (LTCC). The connection of both the top coal caving and its compactness are still rare; therefore, the capability of top coal caving mechanism is the most significant factor in LTCC that must be adequately explained and examined. Moreover, in order to achieve the ideal coal production, a comprehensive modeling of deformation and induced stress is mandatory. In this study, a 12 m thick coal …
การปรับปรุงวิธีการจำแนกพรรณไม้ในเมืองด้วยภาพถ่ายทางอากาศความละเอียดสูง ด้วยการใช้รูปตัดตามแนวลองจิจูด และข้อมูลเสริมจากการสำรวจด้วยไลดาร์ทางอากาศ, สุภาภรณ์ รักษาล้ำ
การปรับปรุงวิธีการจำแนกพรรณไม้ในเมืองด้วยภาพถ่ายทางอากาศความละเอียดสูง ด้วยการใช้รูปตัดตามแนวลองจิจูด และข้อมูลเสริมจากการสำรวจด้วยไลดาร์ทางอากาศ, สุภาภรณ์ รักษาล้ำ
Chulalongkorn University Theses and Dissertations (Chula ETD)
การศึกษาเรื่องการกระจายตัวของต้นไม้ และการจำแนกพรรณไม้ในพื้นที่เมืองมีความจำเป็นอย่างมาก ต่อการบริหารจัดการและติดตามดูแลสิ่งแวดล้อมในเขตเมืองอย่างยั่งยืน งานวิจัยนี้นี้มีวัตถุประสงค์เพื่อปรับปรุงวิธีการจำแนกพรรณไม้ในเมืองด้วยภาพถ่ายทางอากาศความละเอียดสูงด้วยวิธีการจำแนกแบบต้นไม้การตัดสินใจ (Decision Tree) โดยใช้รูปตัดตามแนวลองจิจูด (Longitudinal Profiles) และข้อมูลเสริมจากการสำรวจด้วยไลดาร์ (LiDAR) ทางอากาศเพื่อจำแนกต้นไม้ 7 ชนิดในพื้นที่ศึกษาบริเวณสวนสาธารณะสวนหลวง ร.9 กรุงเทพมหานคร พบว่าการปรับปรุงวิธีการดังกล่าวจากงานศึกษาเดิมสามารถจำแนกต้นไม้ที่มีลักษณะต้นเดี่ยวและกลุ่มทั้ง 7 ชนิดได้อย่างถูกต้อง โดยได้ค่าความถูกต้องโดยรวมเฉลี่ย (Overall Accuracy) 78.7% สังเกตได้ว่าค่าความถูกต้องโดยรวมของการจำแนกมีค่าน้อยกว่างานอ้างอิงที่รายงานค่าความถูกต้อง Overall Accuracy ที่ระดับ 88.9% เนื่องจากลักษณะทางกายภาพของต้นไม้ทั้ง 7 ชนิด มีลักษณะใกล้เคียงกันและแยกออกจากกันได้ยากกว่างานอ้างอิงที่ศึกษาต้นไม้ในพื้นที่ศึกษาเพียงแค่ 3 ชนิด ในอนาคตหากมีการปรับปรุงวิธีการจำแนกด้วยการลดอิทธิพลจากผู้ทดลองและใช้วิธีการเรียนรู้เชิงลึก (Deep Learning) คาดว่าจะสามารถช่วยหาเงื่อนไขของการจำแนกที่ดีที่สุด (optimal criteria) และสามารถจำแนกต้นไม้ที่มีลักษณะใกล้เคียงกันให้ถูกต้องมากยิ่งขึ้นได้ อย่างไรก็ตามลัพธ์ที่ได้จากการวิจัยครั้งนี้ให้ค่าความถูกต้องอยู่ในเกณฑ์ที่ยอมรับได้ ซึ่งสามารถนำไปใช้เพื่อช่วยการบริหารจัดการต้นไม้ในพื้นที่ศึกษาอื่นทีมีพืชคล้ายกันได้อย่างมีประสิทธิภาพ
Business Continuity Planning For A Medium-Sized Hotel Under Covid-19 Outbreak, Arunlak Tangtanapaiboon
Business Continuity Planning For A Medium-Sized Hotel Under Covid-19 Outbreak, Arunlak Tangtanapaiboon
Chulalongkorn University Theses and Dissertations (Chula ETD)
Business Continuity Planning is a subjective conceptual framework prominently used in operations related to supply chain, information technology, or governmental organizations. In this research, we have applied the concept of business continuity planning to a service business during the COVID–19 outbreaks, whose aim is to determine the business continuity objective with the maximum operational tolerable period. The proposed framework has been evaluated based on the ANOVA Test of a guest's service questionnaire of a hotel in Rayong, Thailand. We find that, by reducing business operating cost via staff working hours reduction and limiting service functions of the hotel to the …
การพัฒนาเมมเบรนเพื่อจับแก๊สคาร์บอนไดออกไซด์ด้วยกระบวนการเมมเบรนแก๊สแอบซอร์ปชัน, สุพิชญา ศรีสดใส
การพัฒนาเมมเบรนเพื่อจับแก๊สคาร์บอนไดออกไซด์ด้วยกระบวนการเมมเบรนแก๊สแอบซอร์ปชัน, สุพิชญา ศรีสดใส
Chulalongkorn University Theses and Dissertations (Chula ETD)
งานวิจัยนี้ศึกษาเกี่ยวกับปัจจัยในการขึ้นรูปของเมมเบรนชนิดแผ่นเรียบด้วยวิธีการเปลี่ยนวัฏภาคเพื่อทดสอบประสิทธิภาพการจับแก๊สคาร์บอนไดออกไซด์ด้วยกระบวนการเมมเบรนแก๊สแอบซอร์ปชันซึ่งในกระบวนการดังกล่าวมักพบปัญหาสำคัญที่เกิดจากการใช้งานคือการเปียกของเมมเบรน ซึ่งก่อให้เกิดความเสียหายต่อเมมเบรนและประสิทธิภาพของเมมเบรนในการจับแก๊สคาร์บอนไดออกไซด์ลดน้อยลง โดยในงานวิจัยนี้สนใจที่จะนำสาร 2 ประเภทคือ แอลกอฮอล์ (เมทานอลและเอทานอล) และคาร์บอนแบล็คมาใช้เป็นสารเติมแต่งให้กับสารละลายพอลิไวนิลลิดีนฟลูออไรด์เพื่อปรับโครงสร้างสัณฐานวิทยาและคุณสมบัติความไม่ชอบน้ำของเมมเบรน ผลการศึกษาพบว่าเมื่อเติมสารเติมแต่งประเภทแอลกอฮอล์แล้ว สามารถช่วยเพิ่มขนาดของรูพรุนและความพรุนบนพื้นผิวเมมเบรนได้ โดยเมื่อเติมสารเติมแต่งเมทานอลกับคาร์บอนแบล็ค 5 เปอร์เซ็นโดยน้ำหนักสามารถลดขนาดรูพรุนเฉลี่ยได้ ซึ่งมีค่าเท่ากับ 192.5 นาโนเมตรเนื่องจากสามารถลดค่าความเข้ากันได้ของตัวทำละลายและตัวไม่ละลาย (น้ำ) ที่มีผลต่อการเปลี่ยนวัฏภาคของเมมเบรนให้ช้าลงและเมื่อเพิ่มปริมาณของคาร์บอนแบล็คที่ความเข้มข้นแตกต่างกัน (2.5, 5, 7.5 เปอร์เซ็นโดยน้ำหนัก) ทำให้เพิ่มค่ามุมสัมผัสของความไม่ชอบน้ำของเมมเบรนจาก 79 องศาเป็น 88 องศาและความพรุนบนพี้นผิวของเมมเบรนที่เพิ่มมากขึ้น เมื่อนำไปทดสอบด้วยกระบวนการเมมเบรนแก๊สแอบซอร์ปชันโดยใช้โมโนเอทาโนลามีน 3 โมลาร์เป็นสารดูดซึม ได้ค่าฟลักซ์ของการดูดซึมแก๊สคาร์บอนไดออกไซด์ที่ 3.57±1.1 มิลลิโมลต่อตารางเมตรต่อวินาที