• Composites Research
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• v.21 no.5
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• pp.23-30
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• 2008

Stab threats using sharp edged or pointed Instruments could be easily encountered by police officers or soldiers. In this study, the shear thickening fluids (STF) was impregnated into Kevlar fabrics to improve the stab protection and the resistance of STF impregnated Kevlar fabrics was experimentally investigated. The puncture and cut resistance were tested using a drop test machine withspike and knife indenters fabricated based on the National Institute of Justice (NIJ) standard. The STF was filled with spherical $SiO_2$ particles having an average diameter of 100nm, 300nm, and 500nm. The effect of particle size on puncture and cut resistance of STF impregnated Kevlar fabrics was also investigated. The measured impact load histories showed that STF impregnation into fabric leads to withstand higher peak loads than that of neat fabrics under spike test. The test results showed that Kevlar impregnated with STF exhibit remarkable improvements in puncture resistance while it is slightly influential on the cut resistance. Specifically, particle size is the one of the dominant factors controlling fabric resistance to puncture under spike impact test.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.4
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• pp.591-596
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• 1994

Chemical composition and nutritive values of napier grass (Pennisetum purpureum Schum.) silages subjected to two cutting intervals were studies; 1st harvest in July (A), and 2nd (B) and 1st (C) harvests in November. Each forage was ensiled with 4% molasses in plastic bags and stored for 5 or 9 months. A feeding experiment with castrated goats was conducted from April to June of the following year. Dry matter (DM) and crude protein (CP) content of the harvests varied from 9.5 to 22.8% and 6.6 to 13.6% of DM, respectively. The dry matter content of the silages fed to the goats were 13.0 to 24.4%, because some effluent was removed from each silage before the feeding trial. The pH values of the silages were between 4.03 and 4.29. Goats were given sufficient silage to meet maintenance nitrogen requirements from napier grass silage. Silage C was not completely consumed, and the silage had low digestibilities of DM, CP, hemicellulose and cellulose. Nitrogen balance was slightly positive for goats consuming silage B and was negative for goats consuming silages A and C. Nitrogen utilization was discussed in terms of ruminal $NH_3-N$ and volatile fatty acid concentration in the rumen fluids. It is concluded that goats could not maintain N-equilibrium not only when a younger forage was consumed at a level of N requirement by a restricted feeding, but also when an older forage could not be consumed enough for N requirement because of feed intake limitation.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.321-328
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• 2003

The epithermal gold and base metal deposit of the Tanggeung district of West Java consists of four major veins(Celak, Cigodobras, Cilangkap and Pasirbedil) with NS to N10$^{\circ}$∼20$^{\circ}$E and N75$^{\circ}$W strikes. The veins occur within fractures cutting the crystal and lithic tuff of Jampang Formation(Oligo-Miocene) in and around the Mt. Subang of the western Java, Indonesia. The ore mineralization is characterized by the occurrence of pyrite, sphalerite, galena, chalcopyrite, and small amounts of bornite and Fe-oxides. Hydrothermal alteration, associated with the mineralization, was dominantly silicified and enveloped by the phyllitic(sericitic), argillic and propylitic alteration containing the disseminated pyrite. Gangue minerals consist of interstratified smectite-illite, chlorite, sericite, and minor kaolinite. The presence of vapor-rich fluid inclusions in quartz veins suggests that boiling occurred locally throughout ore deposition. Fluid inclusion studies suggest that the ore fluid evolved from initial high temperatures(〓34$0^{\circ}C$) to later lower temperatures(〓19$0^{\circ}C$). Salinities range from 0.0 to 8.3 wt percent NaCl equiv. The relatively high increase in salinity(up to 8.3 wt percent NaCl equiv) might be explained by a local boiling and by a participation of magmatic fluids, supported by the sulfur isotope results. Evidence of fluid boiling suggests that the pressure decreased from 200 bars to 120 bars. This corresponds to the depths of approximately 750 to 1,200 m in a hydrothermal system that changed from lithostatic to hydrostatic conditions. Using homogenization temperatures and paragenetic constraints, the calculated $\delta$$^{34}$ S values of $H_2S$ in ore fluid are -0.2 to 1.8 permil close to the 0 permil isotopic value of magmatic sulfur.