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Ditemukan 5417 dokumen yang sesuai dengan query
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S. Abdulkareem
"This paper reports on
the investigation of thermal properties of Kapok, Coconut fibre and Sugarcane
bagasse composite materials using molasses as a binder. The composite materials were moulded into
12 cylindrical samples using Kapok, Bagasse, Coconut fibre, Kapok and Bagasse
in the ratios of (70:30; 50:50 and 30:70), Kapok and Coconut fibre in the
ratios of (70:30; 50:50 and 30:70), as well as a combination of Kapok, Bagasse
and Coconut fibre in ratios of (50:10:40; 50:40:10 and 50:30:20). The sample size is a 60 mm
diameter with 10?22 mm thickness compressed at a constant load of 180 N using a Budenberg
compression machine. Thermal conductivity and diffusivity tests were carried
out using thermocouples and the
results were read out on a Digital Multimeter MY64 (Model:
MBEB094816), while
a Digital fluke K/J thermocouple meter PRD-011 (S/NO 6835050) was used to obtain the
temperature measurement for diffusivity. It was observed that of all the twelve
samples moulded, Bagasse, Kapok plus Bagasse (50:50), Kapok plus Coconut fibre
(50:50) and Kapok plus Bagasse plus Coconut fibre (50:40:10) has the lowest
thermal conductivity of 0.0074, 0.0106, 0.0132, and 0.0127 W/(m-K) respectively
and the highest
thermal resistivity. In this regard, Bagasse has the lowest thermal
conductivity followed by Kapok plus Bagasse (50:50), Kapok plus Bagasse plus
Coconut fibre (50:40:10) and Kapok plus Coconut fibre (50:50)."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Abdulkareem S
"This paper reports on the investigation of thermal properties of Kapok, Coconut fibre and Sugarcane bagasse composite materials using molasses as a binder. The composite materials were moulded into 12 cylindrical samples using Kapok, Bagasse, Coconut fibre, Kapok and Bagasse in the ratios of (70:30; 50:50 and 30:70), Kapok and Coconut fibre in the ratios of (70:30; 50:50 and 30:70), as well as a combination of Kapok, Bagasse and Coconut fibre in ratios of (50:10:40; 50:40:10 and 50:30:20). The sample size is a 60mm diameter with 10mm – 22mm thickness compressed at a constant load of 180N using a Budenberg compression machine. Thermal conductivity and diffusivity tests were carried out using thermocouples and the results were read out on a Digital Multimeter MY64 (Model: MBEB094816), while a Digital fluke K/J thermocouple meter PRD-011 (S/NO 6835050) was used to obtain the temperature measurement for diffusivity. It was observed that of all the twelve samples moulded, Bagasse, Kapok plus Bagasse (50:50), Kapok plus Coconut fibre (50:50) and Kapok plus Bagasse plus Coconut fibre (50:40:10) has the lowest thermal conductivity of 0.0074, 0.0106, 0.0132, and 0.0127 W/(m-K) respectively and the highest thermal resistivity. In this regard, Bagasse has the lowest thermal conductivity followed by Kapok plus Bagasse (50:50), Kapok plus Bagasse plus Coconut fibre (50:40:10) and Kapok plus Coconut fibre (50:50)."
Depok: Faculty of Engineering, Universitas Indonesia, 2016
UI-IJTECH 7:6 (2016)
Artikel Jurnal  Universitas Indonesia Library
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H. Jodi
"Batteries on the market
today still use liquid-type electrolytes, which can result in safety issues
caused by electrolyte leakage. Therefore, studies that search for solid-state
electrolytes are important for resolving these issues. In this research, a
composite of lithium phosphate-montmorillonite-polyvinylidene fluoride (Li3PO4-MMT-PVDF)
has been characterized with the aim of detecting the electrochemical
performance of Li3PO4 with the addition of MMT. Li3PO4
samples were prepared through a solid-state reaction, which was then mixed with MMT, which had
a composition ranging from 5 wt% to 20 wt%, and 1 wt% PVDF as a binder. This
characterization was conducted with structural, morphological, and
electrochemical aspects. The structural test showed that the X-ray diffraction (XRD) pattern was dominated by Li3PO4 peaks and MMT aluminosilicates. The electrochemical characterization indicated
that the conductivity value of the composites was greater than that of Li3PO4.
The highest conductivity was achieved with a 15 wt% MMT addition, with a
dielectric-constant value of 74.9 at a frequency of 10 kHz."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Korb Srinavin
"It is widely use of
air-conditioning systems in Thailand due to its location. It is located in a
tropical zone with relatively high temperatures all year round, with high
humidity and high intensity of sunlight. In order to save electrical energy for
air-conditioning systems, preventing heat transfer into the building is
required. The objective of this study is to investigate the physical and
thermal properties of concrete blocks. An attempt is made to increase heat
resistance of concrete blocks. Foam beads (0-0.30% by weight) and kaolin (0-70% by weight) were
added in concrete block mixture to increase discontinuous voids in concrete.
Compressive strength and water absorption of concrete blocks were tested. The
testing results indicated that compressive strength decreased when foam beads
and kaolin were added. Water absorption increased when foam beads were added.
In contrast, the more kaolin added the less water absorption. The thermal
conductivity coefficient of concrete blocks was also investigated. The results
confirmed that the higher the amount of foam beads or kaolin added, the higher
the thermal resistance of concrete blocks. Thermal time-lag behavior was also
investigated. The results indicated that concrete block with kaolin took the
longest time in heating and took the shortest time in cooling. These properties
are good for heat prevention in hot climate regions. These concrete blocks
which were developed and tested in this research conform to the Thai Industrial
Standard. Finally, it can be concluded that because of its thermal behavior,
concrete block with kaolin is a suitable energy-saving concrete block for hot
and humid climates."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Nirattisak Khongthon
"The definition of the physical and mechanical
properties of sugarcane trash pellets were necessary for the design
considerations relating to storage, handling and
processing equipment. The mixing ratios of ground
sugarcane trash:cassava starch:water content (1.0:0.25:0.85 and 1.0:0.25:1.40 by weight) and pelleting speeds (100, 120, 140, and 160 rpm) were considered to determine their effects on bulk
density, true density, porosity, durability and compressive strength. The results show that the mixing ratio by
weight of 1.0:0.25:0.85 and pelleting speed of 120
to 140 rpm were optimum for producing the sugarcane trash pellets. At the moisture content of 12.01% (wb), the bulk density, true density, durability and compressive strength
of biomass pellets were in the range of
330.93 to 365.00 kg/m3, 860.38 to 918.43 kg/m3, 99.34 to 99.46 % and 5.15 to 6.43 MPa, respectively."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Ali Awaludin, author
"Cold formed
steel has relatively high width-to-thickness ratio elements, which causes it to
buckle easily. Combining it with timber laminas would be an effective solution
for reducing this buckling problem. This research focuses on the connection
system of a cold formed steel-timber composite, which was obtained
by attaching several timber laminas to the web part of cold formed
steel using screws. The connection used two bolts that were 8 mm in diameter,
as well as two different kinds of side plates: steel and plywood. Cold formed
steel 75Z08 and Swietenia mahagoni
(moisture content 12.2%; specific gravity 0.77) were used for connections and
were loaded in parallel and perpendicular directions. In addition, the
connections of cold formed steel (without timber laminas) using
self-drilling screw fasteners were tested until failure. Numerical analysis
predicting the load-slip curve and apparent yield load of the composite joints was
carried out using the DOWEL program and the European Yield Theory,
respectively. The test results showed that the connection system with steel
side plates is capable of accommodating the strength increase of composite
member, as it has a maximum load carrying capacity and initial slip modulus of
about 4.5 and 2 times larger than those of the cold formed steel connections, respectively. In the case
of a connection system with plywood side plates, its joint properties are
similar to those of the cold formed steel connection, except that it has larger
joint deformation."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Siti Farhanah SM Johan
"Ballast is one of the
main structures for the railway tracks. It can resist the lateral movement
under dynamic loading transferred by the passing trains with repeatedly. Under
some circumstances, ballast can suffer degradation or breakdown due to the
repeated loading and maintenance. Ballast is easily exposed to the weather
because it is laid on the track. Acid rain affects the performance of the
railway track near the industrial and urban
area. As a result, it starts to foul and the small chips from ballast filled
the void, as well as reduce the shear strength of ballast particles. This
situation can contribute into the increasing of maintenance frequency and
costing. This paper examines the potential of rubber inclusions in increasing
the shear resistance of rubber-ballast composites in simulated water and acid soaked
conditions with several configuration. This lab-based exploratory work is only static load simulation in conventional shear box
setup measuring 60 mm × 60 mm.
The aggregates size is 10 times smaller than actual size of ballast. In order
to identify the shear resistance deterioration of rubber-aggregates mixture
under poor drainage conditions by soaked a batch of aggregates in water and
acid solution for 2 weeks to simulate accelerated weathering effects. The shear
resistance did not rise dramatically with the rubber reinforcement. This
susceptible shear strain plots indicate ductile behaviour on the
aggregates-rubber composites. This is evident by the linear rise of shear
stress with strain up to approximately 10% for the control samples (CS) until
it reaches a constant value. Note that all the specimens including CS are in a
loose state during the testing because there were no tamping been applied on
the samples. Overall the circular patch (CP) specimen was the most favourable
than the other configurations. Both mechanisms contributed to the reduced
overall subsistence, accompanied by an increase in the shear resistance. The
inclusion of rubber elements apparently prevented the dilation of the granular
material when approaching the shear failure and the reducing the settlement."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Nazia Hossain
"Commercialization of
bioethanol has recently intensified due to its market stability, low cost,
sustainability, alternative fuel energy composition, greener output and
colossal fossil fuel depletion. Recently, because of greenhouse intensity
worldwide, many researches are ongoing to reprocess the waste as well as
turning down the environmental pollution. With this scenario, the invention of
bioethanol was hailed as a great accomplishment to transform waste biomass to
fuel energy and in turn reduce the massive usages of fossil fuels. In this
study, our review enlightens various sources of plant-based waste feed stocks
as the raw materials for bioethanol production because they do not adversely
impact the human food chain. However, the cheapest and conventional
fermentation method, yeast fermentation is also emphasized here notably for
waste biomass-to-bioethanol conversion. Since the key fermenting agent, yeast
is readily available in local and international markets, it is more
cost-effective in comparison with other fermentation agents. Furthermore, yeast
has genuine natural fermentation capability biologically and it produces zero
chemical waste. This review also concerns a detailed overview of the biological
conversion processes of lignocellulosic waste biomass-to-bioethanol, the
diverse performance of different types of yeasts and yeast strains,
plusbioreactor design, growth kinetics of yeast fermentation, environmental
issues, integrated usages on modern engines and motor vehicles, as well as
future process development planning with some novel co-products."
2017
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Gowri Shankar
"The present work aims to improve the microstructure and hardness related
properties of age hardened Al6061-SiC reinforced composites produced by a two stage stir casting method. Three composites with
2, 4, and 6wt. % (35-40μm) of SiC reinforcement are subjected to
microstructural examination and hardness test at different locations to analyse
the uniform distribution of the reinforcements in the matrix. As-cast
composites are solution-treated at 558°C, followed by an aging treatment conducted at 100, 150, and 200°C, during which peak hardness values are noted. The peak aged
samples are subjected to hardness and wear tests. In line with the objectives, ranges from 80-100% and 120-145% additional increase in hardness
values are observed over as-cast alloy during the aging treatment conducted at 100, 150 and 200°C, respectively. Lower temperature aging shows
substantial improvement in hardness and wear resistance over high temperature
aging in each respective group. Also
higher weight percentages of reinforced composites show excellent wear
resistance, due to the presence of eroded iron particles from
the counter surface which is regarded as a beneficial effect during the wear test. The presence of SiC particles provides more sites for the nucleation of fine
precipitates. These fine precipitates hinder the movement of dislocation and
thus increases hardness as well as wear resistance after the precipitation hardening treatment."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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Pasawat Sanchumpu
"Recently, there was an
increase in demand of biomass pellets as an alternative energy source. However,
it is necessary to reduce the size of granular materials during the pelleting process.
The size reduction
of eucalyptus bark occurs in the industrial
processing of biomass pellets production, using a hammer mill
together with three sieve sizes of 3, 4, and 5 mm and the sieve speeds of 900, 1000, 1100, and 1200 rpm, respectively, which have been
examined at a feed rate of 80 kg/h. The aims of this study were to determine the
important parameters, namely rotational speed, to determine suitable sieve size
for reducing the size of eucalyptus bark, and to analyze energy usage in the
size reduction process by using a hammer mill. The results have shown that using a 5 mm sieve size at 900 rpm sieve
speed resulted in the best operating conditions in order to offer the highest
capacity and lowest specific energy consumption. Moreover, the average particle size of 0.15
mm was an acceptable value. This study could be very beneficial in the
development process to produce biomass pellets."
2016
J-Pdf
Artikel Jurnal  Universitas Indonesia Library
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