Judul: Identifikasi Masalah Disain dan Uji Kinerja serta Operasi Mesin Pemecah Buah Nyamplung
Abstrak: Nyamplung dried fruit with an average weight of 4.15 g, 34 %moisture content and density 0.54 g/cm3 for each kilogram amounts to 242 pieces while the Nyamplung fresh fruit with an average weight of 4.96 g, 42 % moisture content and density 0.61 g/cm3 for each kilogram amounts to 202 pieces. The force required to break a nyamplung dried fruit is equal to 46.90 kgf while for wet nyamplung fruit amounted to 38.42 kgf. Based on engineering analysis conducted on Nyamplung fruit crusher found that the breaker cylinder shaft diameter 20 mm, 330388.15 hours bearing life already have the technical feasibility, but there are some parts that do not have the technically feasible as the blower shaft diameter 9.5 mm, belt length 1,895 m. Power requirements that need to perform the process of splitting is 0.227 hp. While the result of weighting for the performance test with cracking capacity parameters, the percentage of broken and dirt material, and cracking eficiency is obtained that the best treatment for dry matter is at 1.5 cm cylinder gap distance, while the best treatment for wet materials is at 1 cm and 1.5 cm cylinder gap distance. The problems occur during the engine operation is the fraction of nyamplung fruit that accumulate in the serrations wall and the stacking residual fractions of fruit in the sewer.
Keyword: performance test., engineering analysis, Nyamplung fruit crusher

Judul: Design Evaluation adn Performance Test of Extractor Machine in Date Processing
Abstrak: Buah kurma dapat langsung dikonsumsi ataupun diproses lebih lanjut menjadi produk lain, Di supermarket, pasar, toko atau tempat perbelanjaan lain jarang sekali ditemukan kurma yang sudah diolah melainkan hanya dijual dalam bentuk buah saja. Kebanyakan orang hanya mengonsumsi buah kurma utuh, padahal kurma dapat diolah menjadi produk yang menyehatkan dan praktis dengan diambil sari buahnya yang disebut sari kurma. Penelitian ini bertujuan mengevaluasi desain komponen utama mesin apakah spesifikasi komponen utama sudah memenuhi syarat dan kriteria yang dibutuhkan dalam proses produksi sari kurma di CV Vicomas dan melakukan uji kinerja alat untuk mengetahui kombinasi kecepatan putar pengaduk dan waktu kerja crusher yang paling optimal dalam proses produksi sari kurma di CV Vicomas. Berdasarkan hasil pengukuran dan perhitungan analisis teknik kelayakan didapatkan bahwa kebutuhan daya penggerak 0,4 hp atau 0,3 kWh dengan spesifikasi mesin telah memenuhi standar dengan daya 1 hp atau 0,75 kWh. Kebutuhan daya pencacahan 1,7 kWh atau 2,2 hp dengan spesifikasi mesin telah memenuhi standar dengan daya 3 kWh atau 3 hp. Volume total kurma pada 280 kg sebesar 368.660,108 cm3 sedangkan berdasarkan dimensi yang ada volume penyaring sebesar 377.142,857 cm3 sehingga dapat menampung bahan. Terdapat satu komponen yang kurang tepat untuk standar produksi yaitu ukuran saringan, hasil pengukuran mendapatkan nilai terkecil dari biji kurma 0,58 cm dan lebih kecil dari ukuran saringan dengan 0,6 cm sehingga terdapat kemungkinan biji kurma untuk lolos dari penyaringan yang dapat merusak hasil. Uji kinerja alat dilakukan dengan perlakuan kecepatan putar 22 rpm, 24 rpm, dan 30 rpm dikombinasikan dengan durasi pencacahan 8 menit dan 10 menit. Hasil penelitian menunjukkan perlakuan terbaik dihasilkan dengan kecepatan putar pengaduk 24 rpm dan durasi pencacahan 10 menit menghasilkan kadar air 24,31% yang masuk standar sari kurma, kapasitas kerja mesin mampu menghasilkan 9,20 kg/menit, konsumsi listrik sebesar 0,483 kWh, kehilangan hasil ekstraksi 19%, dan efisiensi ekstraksi 47,29%., Dates can be consumed directly or further processed into other products. In supermarkets, markets, shops or other shopping places, it is rare to find dates that have been processed but are only sold in fruit form. Most people only eat whole dates, even though dates can be processed into healthy and practical products by taking a fruit extract. This study has the goals of evaluating the design of the main components of the machine whether the specifications of the main components have met the requirements and criteria needed in the palm juice production process at CV Vicomas and to test the performance of the extraction machine to determine the combination of the most optimal rotation speed of the mixer and crusher working time in the dates extraction process at CV Vicomas. Based on measurements and technical analysis, it is known that the required stirrer power 0.4 hp or 0.3 kWh with the engine specifications already meeting the standard with a power of 1 hp or 0.75 kWh. The required crusher machine power 2.2 hp or 1.7 kWh with the engine specifications already meeting the standard with a power of 4 hp or 3 kWh. The total volume of dates at 280 kg is 368,660,108 cm3 while based on the existing dimensions
Keyword: performance test, date palm juice, extractor machine, stirrer rotational speed, design evaluation

Judul: Pengaruh vaksinasi terhadap dinamika populasi pada model SIR (Susceptible-Infected-Recovered)
Abstrak: SIR model can be used to model the spread of diseases in a closed population based on certain assumptions. In this research, the SIR model is formulated by including the factor of vaccination. As the result, the model has been shown to have two equilibrium points, i.e. disease free and endemic equilibrium. A simulation study is carried out to illustrate the model. The results show that some equilibrium points are asymptotically stable. Moreover, a minimum level of vaccination has been defined. For the vaccination level less than the minimum level, increase in the vaccination level results in decrease of the proportion of infected individuals in the corresponding equilibrium point. On the other hand, for the vaccination level greater than the minimum level, increase in the vaccination level results in decrease the proportion of susceptible individuals in the corresponding equilibrium point. Furthermore, when vaccination level is greater than the minimum level, it is found that the time needed for the disease to extinct is shorter.
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