Marina Marzuki,Ts.
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/39297
This page provides access to scholarly publication by UniMAP Faculty members and researchers2024-03-29T07:35:27ZEffects of backpack’s weight on school children – a review
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/37347
Effects of backpack’s weight on school children – a review
Marina, Marzuki; Mohd. Asyraf, Che Doi; Rozie Nani, Ahmad
A review of literature was conducted to search what
are the past studies approach and observation related to the
effects of school backpack carrying on primary school children
below 12 years old and solutions in reducing the effects.
Engineering Village, Science Direct and Google Scholars were
searched with the following keywords: backpack, back pain,
load, children, adolescent and physical fitness for related articles.
Sixteen articles were reviewed to see the findings of past
researchers. From the review we came to the conclusion that
there are several factors which contributed to the risk of back
pain and the effects can be observed through their gait postures
response [3, 8, 9] physiological and psychological, [4, 7,10, 11, 16]
and the ground reaction force during walking [12, 14]
In summary, the change in postures include trunk
leaning forward developing a experience of back pain, he time
carrying pack may strongly contribute to back pain. Load should
not exceed 15% of body weight. When carrying load of 15% of
body weight, the children adopted a trunk inclination. This case
is worsened when the load increase to 20% of body weight. This
is because a significant effect was observed at load of 20% of
body weight, where the GRF and trunk inclination increased
almost three times.
National Symposium on Advancements in Ergonomics and Safety (ERGOSYM2009), 1st – 2nd December 2009, Perlis, Malaysia
2009-12-01T00:00:00ZComparison study in consolidation of yttria reinforced iron-chromium composites using conventional and microwave sintering technique
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/33589
Comparison study in consolidation of yttria reinforced iron-chromium composites using conventional and microwave sintering technique
Marina, Marzuki; Mohd Zamzuri, Mohammad Zain; Mohd Nazree, Derman, Dr.; Mohd Asri, Selamat; Nooraizedfiza, Zainon
This research is focused on studying the density and mechanical properties of iron-chromium composites consolidated by innovative rapid microwave sintering technology against conventionally sintered counterparts using slow heating crucible furnace. Another aim of this study is to assess the viability of yttria (Y2O3) ceramic particulates as reinforcement to the iron-chromium composites. Fabrication of iron-chromium-yttria composites consolidated in microwave furnace and conventional crucible furnace was successfully accomplished. Improvement of density is evident in microwave sintered composites. The Y2O3 addition significantly increases the hardness of the composite (118 Hv for microwave specimens as opposed to 110Hv for conventional specimens). The study also successfully established the viability of microwave sintering technique for consolidating iron based powder metallurgy composites by up to 80% reduction of sintering time.
Link to publisher's homepage at http://www.ttp.net/
2014-01-01T00:00:00ZCharacterization of PM Fe-Cr-Y₂O₃ composites prepared by microwave sintering technology
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/32668
Characterization of PM Fe-Cr-Y₂O₃ composites prepared by microwave sintering technology
Marina, Marzuki; Mohd Zamzuri, Mohammad Zain; Mohd Nazree, Derman, Dr.; Mohd Asri, Selamat; Wan Abdul Rahman Assyahid, Wan Ibrahim; Nooraizedfiza, Zainon
This research is focused on assessing the feasibility of the new and innovative microwave sintering technology for fabricating iron-chromium composites prepared via powder metallurgy route. Accordingly, the microwave sintered iron-chromium compacts was benchmarked against conventional sintered counterparts fabricated in other researches. We also studied the viability of yttria reinforcement to the iron-chromium composites with varying weight fraction from 5 to 20 %. Comparison on the end properties were also being made on the unreinforced iron-chromium matrix (0 wt. % of yttria). The result revealed that the microwave sintered iron-chromium composites possess improved density and micro hardness value. Process evaluation also revealed that microwave assisted sintering can lead to a reduction of 70 % of sintering time when compared to conventional sintering. The micro hardness property of microwave sintered iron-chromium was slightly improved with 5 wt. % addition of yttria, although the density and compressive strength were reduced with increasing content of the ceramic particulates. Most importantly, the study has established the viability of microwave sintering approach used in place of conventional sintering for iron based powder metallurgy composites.
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2014-01-01T00:00:00ZCharacteristics of Fe-yttria composites fabricated by powder metallurgy method
http://dspace.unimap.edu.my:80/xmlui/handle/123456789/23465
Characteristics of Fe-yttria composites fabricated by powder metallurgy method
Marina, Marzuki; Kartini, Alir; Wan Abdul Rahman Assyahid, Wan Ibrahim; Nooraizedfiza, Zainon; Mohd Asri, Selamat; Mohd Zamzuri, Mohammad Zain
This study is focused on fabricating and characterizing iron (Fe) composites prepared by powder metallurgy route reinforced with varying weight of Yttria (Y2O3). Composites were prepared based on 5 wt. % to 15 wt. % of reinforcement powder with particle size ranging from 1- 10μm. Pure Fe matrix composites were also prepared for comparison purpose. This paper will report the microstructure, bulk density and micro hardness values of the composites. Powder characterization and microstructures of the composites were examined using Scanning Electron Microscope (SEM) which indicated homogenous distribution of reinforcement particles in the metal matrix. Bulk density of the composites was calculated using standard Archimedean method showing decreasing values as the weight percentage of Y2O3 increases. Micro- hardness was measured using micro-Vickers hardness instrument. The data obtained shows that the Fe-Y2O3 composites samples possessed superior hardness value with the increasing quantity of reinforcement compared to the unreinforced Fe composite.
Link to publisher's homepage at http://www.ttp.net/
2013-01-01T00:00:00Z