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PRODUCTION AND ENERGY PARTITION OF LACTATING DAIRY GOATS FED RATIONS CONTAINING DATE FRUIT WASTE Yuniarti, Endah; Evvyernie, Dwierra; Astuti, Dewi Apri
Media Peternakan Vol. 39 No. 1 (2016): Media Peternakan
Publisher : Faculty of Animal Science, Bogor Agricultural University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (669.563 KB) | DOI: 10.5398/medpet.2016.39.1.27

Abstract

Dates fruit waste (DFW) is a by-product of dates juice industry that contains high energy. So, it is suitable for an energy source in dairy goat ration. This study was conducted to observe the effect of DFW utilization in the ration on energy partition and productivity of lactating dairy goats. The experimental design was randomized block design using 9 primiparous lactating dairy goats. There were three types of ration as treatments used in this study, i.e. R0= 35% forage + 65% concentrate, R1= 35% forage + 55% concentrate + 10% DFW, and R2= 35% forage + 45% concentrate + 20% DFW. Data were analyzed using ANOVA and polynomial orthogonal test. The evaluated variables were dry matter intake (DMI), energy partition including energy intake, digestible and metabolizable energy, fecal and urine energy, energy in methane gas, and energy in milk, milk production and quality. The results showed that the linear decreased of DMI, energy intake, digestible energy, metabolizable energy, and urine energy with the increased of DFW level in the rations. The use of 10% DFW (R1) showed the lowest energy loss through feces and methane gas of all treatments about 1089.57 kcal/head/d and 2.36 kcal/head/d, respectively. The use of DFW did not affect energy retention in milk. The utilization of DFW in ration did not significantly prevent the decline of milk production and milk quality. It can be concluded that DFW can be used as an alternative feed for the lactating dairy goat up to 10% in the ration.
Initial Modelling of Bird Strike by Numerical Simulation in Varied L/D Ratio of Bird Geometry Yuniarti, Endah; H, Simon Shindu; Sitompul, Sahril Afandi
SENATIK STT Adisutjipto Vol 4 (2018): Transformasi Teknologi untuk Mendukung Ketahanan Nasional [ ISBN 978-602-52742-0-6 ]
Publisher : Sekolah Tinggi Teknologi Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (699.363 KB) | DOI: 10.28989/senatik.v4i0.165

Abstract

This research studies influence of bird geometry on impact pressures during bird strike, namely Hugoniot and Stagnation pressure through initial modelling by numerical simulations. Bird geometry is capsule or cylinder with hemisphere end. The geometry is simulated with different L/D ratio, 1.4, 1.6, 1.8 and 2.0. Elastic-plastic hydrodynamic material model is used in simulation. Bird model simulation are using lagrangian method and initial velocities are 200 m/s. The results show variation of L/D ratio provide Hugoniot pressure 10-19 times higher than stagnation pressure in L/D = 1.4, 8-18 times in L/D = 1.6, 9-17 times in L/D = 1.8 and 4-16 times in L/D = 2. Hugoniot pressures show higher in ratio L/D = 1.8 and lower in ratio L/D = 1.6. Stagnation pressure show higher in ratio L/D = 2.0 and lower in ratio L/D 1.4.
EFFECT OF FLAT AND HEMISPHERICALLY ENDED CYLINDER BIRD MODEL WITH FINITE ELEMENT MODELLING OF BIRD STRIKE Yuniarti, Endah
Jurnal Teknologi Dirgantara Vol. 17 No. 1 Juni 2019
Publisher : Lembaga Penerbangan dan Antariksa Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.jtd.2019.v17.a3061

Abstract

This research studies influence of bird model on impact pressures during bird strike, namely Hugoniot and Stagnation pressure through initial modelling by numerical simulations using finite element method. Finite element simulation of bird strike have primarily modelled the bird as either a flat or hemispherically ended cylinder. The geometry is simulated with different L/D ratio, 1.4, 1.6, 1.8 and 2.0. Elastic-plastic hydrodynamic material model is used in simulation. Bird model simulation are using lagrangian method and initial velocities are 100, 200 and 300 m/s. Simulation results of hemispherically ended cylinder bird models show variation of L/D ratio provide Hugoniot pressure 10-19 times higher than stagnation pressure in L/D = 1.4, 8-18 times in L/D = 1.6, 9-17 times in L/D = 1.8 and 4-16 times in L/D = 2. The Hugoniot pressure shows a lower value at an L/D ratio of 1.6 compared to other ratios and the Stagnation pressure is higher at L/D ratio 2. As for cylindrical bird model show variation of L/D ratio provide Hugoniot pressure 35-38 times higher than stagnation pressure in L/D = 1.4, 30-47 times in L/D = 1.6, 31-52 times in L/D = 1.8 and 28-48 times in L/D = 2. The Hugoniot pressure shows a lower value at an L/D ratio of 1.4 and 1.6 compared to other ratios and the Stagnation pressure is higher at L/D ratio 2.
ESTIMASI DISTRIBUSI BERAT SAYAP DAN DISTRIBUSI LIFT UNTUK OPTIMASI BENDING MOMENT DENGAN SISTEM FUEL TRANSFER PADA PESAWAT BOEING 737-500 Arifin, Mufti; Yuniarti, Endah; Sari, Rafika Arum; Said, Ahmad Akmal
JTK: JURNAL TEKNOLOGI KEDIRGANTARAAN Vol 4, No 2 (2019): JURNAL TEKNOLOGI KEDIRGANTARAAN
Publisher : JTK: JURNAL TEKNOLOGI KEDIRGANTARAAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1101.347 KB) | DOI: 10.35894/jtk.v4i2.310

Abstract

Aside from being a manufacturer of lift force, a wing is functioning hold the load that occurs in the structure of the aircraft, such as the shear load, twist and bending. Of all the load the load bending is the greatest burden are received by the wings. Setting the load bending is one of the major factors in reducing the burden experienced by the wing. However, the optimal value indicated opposite between on land and in the air, to take advantage of the situation to use fuel system transfers the load alleviation. Fuel transfer load alleviation is a system that automatically move the fuel more in the tank at the time in part on land and are on the outside of the tank at the time in the air so that the effect of the load bending bending loads can be reduced, which generated as the result of addition between the weight distribution and the distribution of lift that occurs on the wings so as to calculate the bending data needed weight distribution and the distribution of lift on the wing. This research aims to know the weight distribution occurs on the wings of the Boeing 737-500. The value of the weight distribution and distribution of lift yield optimization moment on two States namely, on land and in the air with three variations of the fuel transfer that is, constant with a value of 40134.53 N, linear with a value of 48059.53 N, and the maximum value of 172386.50 N.
ANALISIS NUMERIK PENGARUH GEOMETRI BURUNG TERHADAP TEKANAN IMPAK PADA KASUS BIRD STRIKE DENGAN SMOOTHED PARTICLE HYDRODYNAMICS (SPH) MODEL Yuniarti, Endah; Sitompul, Sahril Afandi; Warsiyanto, Budi Aji
JTK: JURNAL TEKNOLOGI KEDIRGANTARAAN Vol 5, No 1 (2020): Jurnal Teknologi Kedirgantaraan
Publisher : JTK: JURNAL TEKNOLOGI KEDIRGANTARAAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35894/jtk.v5i1.426

Abstract

Penelitian ini mempelajari pengaruh geometri burung terhadap tekanan impak pada kasus tabrak burung, yaitu tekanan hugoniot dan stagnasi. Geometri burung berbentuk capsule atau silinder dengan kedua ujung setengah bola. Geometri disimulasikan dengan rasio L/D yang berbeda yaitu 1,5; 1,7; dan 1,9. Model material burung elastis, plastis, hidrodinamik digunakan pada simulasi. Simulasi model burung dilakukan dengan metode Smooth Particle Hydrodynamics (SPH) pada variasi kecepatan 100 m/s, 200 m/s, dan 300 m/s. Hasil simulasi menunjukkan dengan variasi rasio L/D diperoleh nilai tekanan Hugoniot jauh lebih tinggi sekitar 14-25 kali lipat tekanan stagnasi pada L/D = 1.5, 12-25 kali pada L/D = 1.7, dan 11-34 kali pada L/D = 1.9. Tekanan Hugoniot menunjukkan nilai yang meningkat dari L/D 1.5 sampai 1.9 pada kecepatan 100 m/s. Namun, untuk tekanan Hugoniot pada kecepatan 200 m/s menunjukkan nilai yang menurun dari L/D 1.5 sampai 1.9. Tekanan stagnasi rasio L/D 1.9 lebih rendah dibandingkan L/D 1.5 dan 1.7 pada kecepatan impak 100 dan 200 m/s.