1,721,012 research outputs found
UniMAP Researcher Receive Endeavour Leadership Australia Research Fellowship Award 2019
Full text linkPenyelidik dari Pusat Pengajian Kejuruteraan Bahan, Universiti
Malaysia Perlis (UniMAP), Prof. Madya Dr. Ong Hui Lin terpilih sebagai penerima
Anugerah Fellowship Kepimpinan Penyelidikan Endeavour Australia Cheung Kong
Research 2019
Thermal properties of biocomposites based on sea mango fibers
No full textAccess is limited to UniMAP community.The effect of sea mango (SM) filler loading and the effect of amount used of polypropylene-graft-maleic anhydride (PP-g-MA) added as a compatibilizer on thermal properties and flow behavior of biocomposites were studied. The compounding of
polypropylene/sea mango biocomposites was carried out using different in weight
percentage of sea mango filler based on composite and different weight percentage of PPg-
MA based on weight of polypropylene (PP). Polypropylene/sea mango filler
biocomposites were compounded using a heated two roll mills at 165 °C and rolls rotating
speed of 10 rpm for 15 minutes. Then mixed samples were then compressed by using a
hydraulic hot press to form sheet samples of biocomposites at 1 mm of the thickness. The
result shows the effect of increment in filler loading were slightly increased in degradation
temperature, and slightly decreased in thermal stability, melting temperature, crystalline
temperature and percentage of crystallinity, and reduction melt flow index. It was also
found that the addition of PP-g-MA offer better processability and flow properties in
polypropylene/sea mango filler with PP-g-MA biocomposites than polypropylene/sea
mango biocomposites without PP-g-MA
The durability of modified silica/polypropylene nanocomposites : weathering resistance and creep behavior
No full textMaster of Science (Material Engineering)In this research, the modified silica (SiO2)/polypropylene (PP) nanocomposites were prepared. The accelerated weathering and creep behavior of nanocomposites were investigated. Neat PP with 2 wt% of nanosilica and 3 wt% of modifiers (aminopropyl triethoxysilane (APTES), polypropylene grafted maleic anhydride (PP-g-MA) and polypropylene-methyl polyhedral oligomeric silsesquixone (PP-POSS)) were melt blended in the internal mixer Brabender with rotor speed 60 rpm for 10 minutes. The nanocomposites characterizations were determined by Fourier transform infrared analysis (FTIR) and field emission scanning electron microscope (FESEM). While the mechanical properties of the nanocomposites were determined using a tensile test instrument according to ASTM D638 and thermal behavior through thermalgravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively, before and after exposure to accelerated weathering test (AWT). The durability behavior of nanocomposites was tested under creep test instrument according to ASTM D2990. From the FTIR analysis, weathered nanocomposites with the PP-POSS showed less carbonyl group which related to the degradation phenomenon to the material comparing to the nanocomposites with APTES, PP-g-MA and without modifiers. Moreover, FESEM images showed less cracking and deformation on the tensile fractured surface of weathered nanocomposites with PP-POSS validating the efficiency of the modifiers. While, from tensile results, the weathered nanocomposites especially with the presence of PP-POSS followed by PP-g-MA and APTES have higher tensile strength but moderate reduction in elongation at break than the weathered nanocomposites without the modifiers. In the terms of thermal behavior, PP-POSS showed good thermal stability compared to other nanocomposites. While for the durability test, the presence of modifiers in the modified silica/PP nanocomposites exhibited good resistance to the creep. PP-POSS provided better improvement creep resistance compared to the nanocomposites with PP-g-MA, APTES and without modifier. This can be concluded that the addition of modifiers improved the weather resistance and creep resistance of nanocomposites
Tensile and thermal properties of tapioca starch/sugarcane bagasse cellulose biocomposite films
No full textAccess is limited to UniMAP community.Cellulose was extracted from raw sugarcane bagasse (SCB) through chemical
route such as alkaline treatment and bleaching process. Cellulose obtained was
characterized and compared by Fourier transform infrared (FTIR) spectroscopy, X-ray
diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric
analysis (TGA). FTIR results show the reducing peak that related to non-cellulosic
components after chemical treatment. XRD analysis showed that cellulose has higher
crystallinity compared to raw SCB. SEM images illustrated the reducing in diameter of
fibre and increasing of roughness after undergoing chemical treatment. TGA analysis
revealed that cellulose has better thermal stability than raw SCB. The composite film of
tapioca starch and cellulose had been characterized and tested by XRD, SEM, TGA, and
tensile testing. XRD results show that composite with 5 phr cellulose has highest
intensity and crystallinity. SEM images of tensile surface fracture proved the good
interaction between filler and matrix for 5 phr cellulose content composite. TGA results
show neat starch film has highest thermal stability while tensile testing revealed
composite with 5 phr cellulose have the highest tensile strength and modulus of
elasticity
The durability of modified Silica/Polypropylene nanocomposites: weathering resistance and creep behavior
No full textIn this research, the modified silica (SiO2)/polypropylene (PP) nanocomposites were
prepared. The accelerated weathering and creep behavior of nanocomposites were
investigated. Neat PP with 2 wt% of nanosilica and 3 wt% of modifiers (aminopropyl
triethoxysilane (APTES), polypropylene grafted maleic anhydride (PP-g-MA) and
polypropylene-methyl polyhedral oligomeric silsesquixone (PP-POSS)) were melt blended
in the internal mixer Brabender with rotor speed 60 rpm for 10 minutes. The
nanocomposites characterizations were determined by Fourier transform infrared analysis
(FTIR) and field emission scanning electron microscope (FESEM). While the mechanical
properties of the nanocomposites were determined using a tensile test instrument according to ASTM D638 and thermal behavior through thermalgravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively, before and after exposure to accelerated weathering test (AWT). The durability behavior of nanocomposites was tested under creep test instrument according to ASTM D2990. From the FTIR analysis, weathered nanocomposites with the PP-POSS showed less carbonyl group which related to the degradation phenomenon to the material comparing to the nanocomposites with APTES,PP-g-MA and without modifiers. Moreover, FESEM images showed less cracking and deformation on the tensile fractured surface of weathered nanocomposites with PP-POSS validating the efficiency of the modifiers. While, from tensile results, the weathered nanocomposites especially with the presence of PP-POSS followed by PP-g-MA and APTES have higher tensile strength but moderate reduction in elongation at break than the weathered nanocomposites without the modifiers. In the terms of thermal behavior, PPPOSS showed good thermal stability compared to other nanocomposites. While for the durability test, the presence of modifiers in the modified silica/PP nanocomposites exhibited good resistance to the creep. PP-POSS provided better improvement creep resistance compared to the nanocomposites with PP-g-MA, APTES and without modifier. This can be concluded that the addition of modifiers improved the weather resistance and creep resistance of nanocomposites
Synthesis, characterization and properties of low density polyethylene filled with reduced graphite oxide
No full textDoctor of Philosophy in Materials EngineeringGraphite based materials have become promising candidates in polyolefin
nanocomposites in widening the application such as a packaging material. However, the
utilization of these combination exhibits a doubt on how was the effect once heat is
applied onto the nanocomposites. Herein, a systematic study has been carried out to
investigate the effect of reduced graphite oxide (rGO) towards low density polyethylene
(LDPE). A simple solvent casting method was carried out in fabricating low density
polyethylene / reduced graphite oxide (LDPE/rGO) nanocomposites with the filler
contents of 0.05 – 1 wt%. Without any modification between LDPE and rGO, several
characterizations have been implemented towards the nanocomposites. Optical
properties through UV-visible spectroscopy were effectively identifying the
transparency of the nanocomposites, where the transparency decreased with the
increased of rGO. The tensile test was also carried out in order to determine the tensile
properties of the fabricated film. Thin film with 0.3 wt% of rGO content has showed
highest tensile strength compared to the rest of the nanocomposites film. Gas barrier
together with the dielectrical properties of the nanocomposites were studied in depth.
Transmission electron microscopy (TEM) was employed to observe the dispersion and
morphology of the rGO in LDPE. Further, thermal decomposition of the
nanocomposites was investigated through thermogravimetric analysis (TGA). Kinetic
studies on the degradation nanocomposites had concluded that Flynn-Wall-Ozawa
(FWO) model is one step higher compared to Kissinger (K) model. In order to identify
the elements that decomposed, gas chromatography (GC) and mass spectroscopy (MS)
coupled with TGA were used to separate the evolved compounds into alkane, alkene
and aromatic groups, respectively. Where, toxic gaseous will only being released out
when the nanocomposites was heated up to 460 °C. With the addition of rGO in the
LDPE matrix, the degradation behaviour of the nanocomposites was identifying
through UV radiation. There is only slight difference on the thin film’s properties after
360 hours of UV-B radiation. Based on the analysis, the studies clearly indicated that
the feasibility of incorporating rGO into the LDPE matrix had improved the optical,
mechanical, thermal and dielectric properties. This has widened the application of
LDPE/rGO nanocomposites in serving as a packaging material
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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