Sifat fisik dan mekanik material komposit partikel dipengaruhi oleh ukuran partikel. Variasi ukuran partikel akan membentuk sifat fisik dan mekanik yang berbeda. Variasi ukuran yang digunakan yaitu 100 mesh, 150 mesh, 200 mesh. Perbandingan matrix dan partikel yaitu 70% : 30 % menggunakan metode hand lay-up. Pengujiannya terdiri dari uji fisik yaitu kerapatan dan pengembangan tebal serta pengujian mekanik yang terdiri dari Modulus Of Rapture (MOR) dan Modulus Of Elastisity (MOE). Hasil pengujian fisik kerapatan berada pada nilai 0,93-1,02 g/cm3, kerapatan terbaik pada ukuran partikel 100 mesh dengan nilai 1,02 g/cm3. Sedangkan pengujian tebal diperoleh nilai yang berkisar 9,3-9,8 %, dengan pengembangan tebal tertinggi 9,8 % pada ukuran partikel 100 mesh. Sedangkan hasil pengujian mekanik sendiri seluruh variasi ukuran mesh memenuhi standar yaitu uji MOR tertinggi didapatkan pada variasi 100 mesh yaitu dengan nilai 341,15 kgf/cm2 sedangkan pada uji MOE tidak ada yang memenuhi standar SNI 03- 2105-2006 variasi mesh tertinggi didapatkan oleh mesh didapatkan pada mesh 100 yaitu 8072,49 kgf/cm2.
The mechanical properties of natural fibers are continuous development as the alternatively synthetic fibers because of the natural fibers are non-corrosive, lightweight, and environmental advantages. However, these fibers have poor interfacial adhesion properties as the fibers if used as bio-composite material. This problem can be solved by the surface modification method by the sodium hydroxide treatment used to improve the mechanical properties. A sodium hydroxide concentration which it used at 0 wt%, 5 wt%, 10 wt%, and 15 wt% and the sisal fibers were soaked in that a concentration for 2 hours. Furthermore, the bio-composite fabrication is conducted by hand lay-up technique which is using both sisals as the fibers and epoxy resin as the matrix. The tensile test RTG-1250 results show that the maximum mechanical properties, such as strains, Young's modulus, and elongation, was obtained at sodium hydroxide 5 wt% than others where the values of these mechanical properties were 25.334 MPa, 16.111 GPa, and 1.572%, respectively. The morphological evaluation carried out using a scanning electron microscope showed that the alkali sodium hydroxide treatment was improved interfacial adhesion between fiber and matrix. Finally, sodium hydroxide alkali treatment of more than 5% can be able to sisal fiber cracks so that the mechanical properties of bio-composite can decrease continuously.
Candlenut (Aleurites moluccana Wild) is an important versatile plant in Indonesia.Batulanteh Subdistrict, Batu Dulang Village is the highest candlenut producer in Sumbawa Regency, NTB with a land area of 595.7 ha and total production of 285.17 tons. Post-harvest candlenut handling at the farmer's level is still done traditionally where drying candlenuts on the floor or para-finished needs to be done with solar dryers. In this research, testing on absorbent plates is flat and corrugated as well as natural drying. The results showed that the corrugated heat absorber plate had the highest temperature average of 86.84 oC with a drying time of 8 hours with the amount of hazelnut water content of 6.12%. Making zinc absorbent plates is more effective and efficient used to dry candlenut in increasing the production of candlenuts. AbstrakKemiri (Aleurites moluccana Wild) adalah tanaman serbaguna yang penting di Indonesia. Kecamatan Batulanteh, Desa Batu Dulang adalah penghasil kemiri tertinggi di Kabupaten Sumbawa, NTB dengan luas lahan 595,7 ha dan total produksi 285,17 ton. Penanganan kemiri pasca panen di tingkat petani masih dilakukan secara tradisional dimana pengeringan kemiri di lantai atau parafin harus dilakukan dengan pengering surya. Dalam penelitian ini, dilakukan pengujian pada pelat penyerap datar dan bergelombang serta pengeringan alami. Hasil penelitian menunjukkan bahwa pelat penyerap panas bergelombang memiliki rata-rata suhu tertinggi 86,84 o C dengan waktu pengeringan 8 jam dengan jumlah kandungan air 6,12%. Pelat penyerap seng lebih efektif dan efisien digunakan untuk mengeringkan kemiri dalam meningkatkan produksi kemiri. Kata kunci: Kemiri, pengering surya, pelat penyerap, kadar air kemiri.
Single leaf spring is one of the suspension systems on vehicles that function as vibration dampers which usually use steel. One type of steel that is often used in making single leaf springs is 55Si7 steel. However, at this time composite materials began to be used as an alternative material to replace steel. One of the composite materials used as a substitute for steel is E-glass epoxy. This study aims to determine differences in the characteristics of steel leaf springs and e-glass epoxy composites. In addition, the effect of orientation of the fiber direction to deformation, stress, and safety factors on leaf springs was also carried out in this study. The analytical method used is finite element. The results showed that the composite leaf springs had lower stress than steel leaf springs. E-glass epoxy composite leaf springs variation D (fiber orientation 45º / -45º) showed the lowest stress and highest safety factor with values of 596 MPa and 1.4 respectively.
Flotasi merupakan proses ekstraksi logam berdasarkan perbedaan tegangan permukaan dari mineral di dalam air dengan cara mengapungkan mineral ke permukaan. Faktor yang mempengaruhi nilai perolehan kembali Tembaga antara lain ditentukan oleh ukuran partikel, jumlah persen padatan dan kondisi larutan. Pada penelitian ini akan dilakukan pengamatan terhadap perolehan kembali mineral tembaga dengan melakukan variasi ukuran partikel, variasi persen padatan pada jumlah 33%, 42% dan 47% dan variasi pH larutan pada kondisi basa yaitu pH 10, 10.3 dan 10.6. Pengecilan ukuran partikel dilakukan dengan proses Grinding sampai mendapatkan ukuran + 212 mikron. Selanjutnya, pH larutan dikontrol dengan penambahan kapur. Analisis perolehan kembali mineral tembaga secara kuantittatif dilakukan dengan karakterisasi AAS. Hasil penelitian menunjukkan bahwa ukuran partikel yang optimum didapat pada pada variasi 3% +212 mikron dengan nilai 95.12%. Sedangkan, jumlah persen padatan 42% memberikan nilai tertinggi yaitu 95.12%. Selanjutnya, diperoleh pH terbaik untuk memperoleh tembaga yang optimum yaitu pada pH 10.6 sebesar 95.12%
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.