<span>Komposit merupakan sejumlah sistem multi fasa sifat gabungan, yaitu gabungan antara bahan matriks atau pengikat dengan penguat. Penelitian ini dilakukan menggunakan metode kuantitatif dengan rancangan penelitian eksperimental serta membandingkan hasil pengujian pada metode elemen hingga yang dilakukan penelitian di laboratorium. Objek penelitian berupa serat tempurung kelapa yang dipilih karena melimpahnya sumber daya alam tersebut. Spesimen matriks resin dibuat dengan standar ASTM D 638 M-84 dengan bahan resin epoksi dan katalis menggunakan metode pengecoran. Teknik pengumpulan data yang digunakan adalah teknik pengujian laboratorium. Instrumen yang digunakan berupa lembar pencatatan. Dari hasil penelitian yang dilakukan didapatkan kekuatan tarik komposit tertinggi dengan tata letak random sebesar 3,38 kgf/mm2 dan perpanjangan sebesar 0,38 mm, <em>Cross</em> sebesar 3,03 kgf/mm2 dan perpanjangan sebesar 0,86 mm, <em>continuous</em> sebesar 2,24 kgf/mm2 dan perpanjangan sebesar 1,03 mm, <em>woven</em> sebesar 1,64 kgf/mm2 dan perpanjangan sebesar 0,64 mm. Bentuk patahan menunjukan bahwa hasil pengujian tarik mengalami patahan getas, karena ujung patahan terdapat patahan 900 dan kasar di karenakan adanya mekanisme <em>fiber pull out</em>.</span>
Bahan bakar fosil merupakan sumber energi utama untuk aktivitas industri, transportasi, produksi listrik dan kegiatan pertambangan. Emisi gas hasil pembakaran bahan bakar fosil secara teoritis mengandung polutan emisi gas yang terdiri dari gas-gas CO<sub>x</sub>, NO<sub>x</sub>, HC, O<sub>x</sub>, SO<sub>2</sub> dan logam-logam berat. Pembakaran bahan bakar fosil pada sektor transportasi berkontribusi paling besar terhadap polusi yang dihasilkan oleh emisi gas buang mesin otomotif. Oleh karena itu perlu dilakukan penanganan yang tepat terhadap emisi gas mesin otomotif ini. Hal ini telah dirancang bentuk geometris alat yang berfungsi sebagai media adsorbsi emisi gas mesin otomotif yang disebut bed reactor (BR). Bentuk geometris dari BR dirancang merujuk kepada bentuk geometris dari knalpot (muffler) kenderaan mobil mini bus. BR yang dirancang terdiri dari 2 (dua) jenis BR yaitu jenis aliran laminar dan aliran turbulen. Bentuk geometris BR, berbentuk penampang elips dengan sumbu mayor = 192 mm, sumbu minor = 125 mm, dan panjang muffler = 320 mm, untuk jenis aliran laminar. Sedangkan BR jenis aliran turbulen berbentuk penampang elips dengan sumbu mayor 192 mm dan sumbu minor 125 mm, dan panjang muffler L = 350 mm. Daya adsorbsi BR telah diuji dengan bantuan alat uji emisi gas jenis anycar autochek gas & smoke versi 1.5.1.E-1. Daya adsorbsi BR maksimum untuk jenis aliran laminar terhadap gas CO<sub>2</sub> = 47,76 % dan untuk aliran turbulen CO = 42,72 % & gas HC = 35,40 %, masing-masing BR diisi zeolit alam dengan besar butir 10 mesh.
Recycle compressor used at PT. Lotte Chemical Titan Nusantara utilizes a four-stage piston compressor type. The compressor increases the gas pressure from the S-425 degasser at 0.3 bar to the R-400 reactor with a pressure of 22 bars. Evaluation of a compressor performance encompasses assessment over a number of aspects such as the capacity and volumetric efficiency of each stage, mechanical efficiency, compressor power, and cost saving. Performance analysis on the C-470 compressor implied a decrease in a performance marked by a decrease in mechanical efficiency from the design at 96.43% to the actual condition at 79.72%, along with the decrease in volumetric efficiency from the initial design to the actual efficiency for each stage. The differences occurred due to the changes in pressure and temperature of the input and output fluid at each stage. However, the compressor still appropriates to save the cost up to 99.7% with actual efficiency of 79.72%.
Bamboo is a renewable material widely used as a reinforced composite. One of the steps in making bamboo composites is soaking or heating using NaOH. The process is intended to eliminate small animals that may live in the bamboo. The attainment of strength and toughness is the most crucial requirement in structural material. This study compared the Apus, Atter, and Black bamboo fiber‘s strength by administering several methods and applying three different extraction times. The methods are the 5% NaOH chemical extraction method at a temperature of 70°C (heated), the 5% NaOH chemical extraction method (permeated) at room temperature, and the extraction method without treatment nor administering heat. The highest tensile strength among the three methods for each Apus, Atter, and Black bamboo is 194.25 N/mm2, 142.67 N/mm2, and 178.46 N/mm2, respectively. Among the mothed used in this research, heating the bamboo in 5% NaOH solution with a 70°C temperature is more effective than soaking it at room temperature. The strength was increased up to 112%, 98%, and 190% for Apus, Atter, and Black bamboo. Black bamboo shows a significant improvement by using a chemical extraction process.
One of the analytical tools that can be used to help, parse, identify and map traffic accident problems in an area is a Geographic Information System (GIS). GIS is used to create clusters of traffic accident events. The level of accident vulnerability in this paper is obtained by calculating the density of the number of incident points where the accident occurred, namely Depok and Kalasan Districts, Sleman Regency on a road segment length of 1,000 m per year. The clustering methods used are kernel density and k-medoids methods. Comparison of the identification of traffic accident-prone levels in Depok and Kalasan sub-districts using the Kernel Density and K-Medoids methods with a road length of 1,000 meters using the Kernel Density and K-Medoids methods in 2018 there is the same difference, namely 6.17% with the medium level classification and low level classification. For 2019 it is 0.01% with a high level classification, 1.85% for the medium level and 1.86% for the low level. For 2020 there is the same difference, namely 1.23% with medium and low level classifications. For 2021 there is no difference for high level classification but there is the same difference for medium and low level classification which is 3.7%.
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