1,720,973 research outputs found
Synthesis and mechanical properties of alumina slip casting from aluminum tri-hydrate (Al(OH)₃
No full textAccess is limited to UniMAP community.This experiment was done to investigate the mechanical properties of synthesized
Al(OH)₃ for slip casting process. The Al(OH)₃ precursor was synthesized by two process,
calcinations of Al(OH)₃ and leaching along with calcinations of Al(OH)₃. Ceramics bodies
were produced using those synthesized precursor by slip casting process with different sintering time and temperature. It is to see how the synthesized and sintering time and temperature governed the mechanical properties of ceramics bodies. The results showing that the mechanical properties of ceramics bodies by leached precursor produced better properties compared to ceramics bodies by calcined precursor. The mechanical properties were increase as the sintering temperature was increased but for sintering time the mechanical properties were dropping at longer sintering time and higher sintering
temperature
Production of self-compacting concrete containing limestone powder with the effect of internal and external salts
No full textMaster of Science in Materials EngineeringThis study aims at investigating the influence of different amounts of internal sulphate (CaSO4) and external salts on the properties of Self-Compacting Concrete (SCC). Three sets of mixes (No.1), (No.2) and (No.3) which are reference mix, mixes with internal sulphate and mixes exposed to external salts respectively are designed with the same mix proportion and maximum size of aggregate 10 mm. In order to determine the selfcompacting concrete, different tests are adopted such as Slump flow, V-funnel, L-box and U- box test. These tests are carried out to ensure that the mixes satisfy the requirement of SCC and to determine the effect of internal sulfate on the filling ability, passing and segregation resistance of SCC. The mechanical properties studied are the compressive strength, splitting strength, flexural strength, and modulus of elasticity.
These tests are to be investigated under the effect of salt attack . Furthermore, a non–
destructive test method is used, which is ultrasonic pulse velocity used to assess the
dynamic properties of concrete. At age 28 days, compressive strength for all mixes
ranges between (23.81-44.09) MPa for standard cubes measuring 150 mm and (16.56-
25.95) MPa for cylinders 150x300 mm, the compressive strength at 60 days, ranges
between ( 23.51-36.57) and ( 13.24-30.87) MPa for cubes and cylinder respectively. It
appears from the results that the compressive strength of mixes with external salts is
larger than the mixes with internal sulphates for ages 28,60 and 90 respectively except
that at age 180 days the mix L5 is the highest
Studied on the mechanically activated and thermally treated dolomite for adsorption application
No full textAccess is limited to UniMAP community.Dolomite from Chuping, Perlis was mechanically activated at different parameters of planetary milling (ball:powder ratio, miiling time and revolution speed) and thermally treated within temperature range 600-1000 °C. The changes of structural and modifications
undergone by dolomite, inherent to the mechanical activation and thermal treatment, were
investigated from X-ray diffraction patterns. The chemical composition and elemental
constituents of the raw dolomite samples was determined using X-ray fluorescence (XRF)
and energy dispersive X-ray spectroscopy (EDX). The results were also discussed using
scanning electronic microscopy and nitrogen adsorption. Thermogravimetric and
differential thermal analyses indicated that the dolomites undergo two stages of
decomposition during the calcination process. Results obtained showed that high revolution
speed and longer grinding duration have pronounced effect on the grindability, increase in
fineness, decrease in crystallite sizes and amorphization of Perlis dolomite. . SEM analysis
of calcined dolomite indicated that the morphological properties were profoundly affected.
SEM images of D-1000 (sample treated at 1000 °C) indicated that the original particle
shape of dolomite (presence of discrete grains having sharp edges with presence of
cleavages) was totally destroyed, leading to small spherical particles. From BET analysis, it
shows that the surface area and pore size increases as calcination temperature increases. As
the conclusion, structural and morphology of dolomite undergo changes and modifications
due to the mechanical activation process and thermal treatment
Lattice Imperfections in Intermetallic Ti-Al alloys: an X-Ray Diffraction study of the microstructure by the Rietveld method
No full textMicrostructure in intermetallic Ti-Al alloys with compositions of Al= 45, 50, 55, and 60%
in the homogenized bulk states has been extensively studied using Rietveld whole X-ray profile fitting technique, adopting the recently developed softwares, C-Rietan2000 and MAUD (Material Analysis Using Diffraction). The respective microstructures were observed under SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive
Spectroscopy). The Vickers microhardness and density values of the samples were determined. The analysis also considers the quantitative estimation of different phases and lattice defect related features of the evoluted microstructures, namely crystallite sizes and microstrains in the bulk homogenized state. The values of all the above defect parameters have been evaluated and compared for elucidating a better structure-property relationship
Solar Hydrogen Generator : Fuel for Future
No full textEkspo ini berlangsung di Dewan Sek. Men. Putra, Kangar, Perlis.Transport of ionic hydrogen species in the aqueous electrolyte. Transport of electronic charge carries within the electrodes and the external circuit
Preparation of Photoresponse n-TiO2 for hydrogen and oxygen evolution reactions in an electrochemical cell
No full textToday, energy crisis triggered by depletion and pollution aspect of fossil fuels, has urged the need to search of clean and renewable energy, which can effectively substitute petroleum. The use of hydrogen as an environmentally friendly fuel had been encouraged since the combustion of hydrogen results in the generation of water, which neither results in air pollution nor leads to the emission of greenhouse gases. A sol-gel method with powder methodology processing has been implemented in this experiment to prepare for the BST, BaxSr1-xTiO3 bulk film to evaluate the solar hydrogen energy generating in photo-electrochemical cell (PEC). The structure and morphology are the main factor in concern. Results showed that composition of Ba0.4Sr0.6TiO3 and Ba0.6Sr0.4TiO3 are good composition in generating the photo-voltage of solar hydrogen
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Skutterudite structure and thermoelectric property in MyFe4-xCoxSb12 (M=lanthanoid metal): Phonon Glass electron crystal
No full textOrganized by Kolej Universiti Kejuruteraan Utara Malaysia (KUKUM), 15th June 2006 at DKG 4 & DKG 5, Kubang Gajah, Arau, Perlis.From the simple CoSb3 to MyFe4-xCoxSb12 (M=lanthanoid metal) skutterudite compound has been studied in term of it structure and thermoelectric properties. The changes of structure within the insertion of different element of lanthanoid elements were discussed. The structure with phonon glass electron crystal (PGEC) model showed promising value to attain high thermoelectric properties for the compound. The classification of the materials to be in PGEC behavior led the understanding on the demanding properties for thermoelectric. Thus, relationship between the PGEC behavior and thermoelectric properties are also discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
