Judul: Utilization of Cocoa Skin Waste Biochar
(Theobrama cacao L) in Feed on Carcass Percentage, Commercial Cuts and
Chicken Giblet
Abstrak: Penelitian ini bertujuan untuk mengevaluasi penggunaan biochar limbah kulit kakao (Theobrama cacao L) dalam pakan terhadap persentase karkas, potongan komersial dan jeroan ayam kampung. Rancangan percobaan yang digunakan dalam penelitian ini yaitu Rancangan Acak Lengkap (RAL) dengan 4 perlakuan 4 ulangan. Perlakuan yang digunakan adalah P0: pakan komersial, P1: pakan penelitian ayam kampung tanpa biochar P2: pakan penelitian ayam kampung + 1% biochar, P3: pakan penelitian ayam kampung + 2% biochar. Peubah yang diamati dalam penelitian ini adalah bobot potong, persentase karkas, potongan komersil karkas serta jeroan meliputi hati, jantung dan ampela. Data dianalisis menggunakan Analisis Varians (ANOVA) oleh program SPSS versi 25.0 dan jika hasil pengujian ada yang berbeda nyata maka dilakukan uji lanjut dengan perbedaan nyata terkecil menggunakan metode uji Duncan. Hasil penelitian ini menunjukkan bahwa bobot potong, persentase karkas, sayap, dan jeroan tidak berpengaruh terhadap pakan perlakuan penambahan biochar, sedangkan persentase dada, punggung, dan paha berpengaruh terhadap pakan perlakuan.
Keyword: biochar, carcass, commercial cuts, giblet

Judul: Uji Sifat Fisik Biochar Limbah Kulit Kakao Dan Pengaruhnya Terhadap Saluran Pencernaan Ayam Kampung
Abstrak: Penelitian ini bertujuan menguji sifat fisik biochar dari limbah kulit kakao dan pengaruhnya terhadap saluran pencernaan ayam kampung. Sebanyak 160 ekor DOC ayam kampung jenis Sentul terseleksi yang dipelihara hingga panen umur 63 hari (9 minggu), sampel yang digunakan pada penelitian sebanyak 16 ekor yang terdiri dari 2 ekor ayam jantan dan 2 ekor ayam betina dari masing-masing perlakuan. Penelitian ini terdiri dari perlakuan P0 (pakan komersial), P1 (pakan penelitian tanpa biochar), P2 (pakan penelitian mengandung biochar 1%), dan P3 (pakan penelitian mengandung biochar 2%). Rancangan percobaan yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 4 ulangan. Pengukuran peubah yang diamati meliputi kadar air, aktivitas air, berat jenis, ukuran partikel dari biochar dan pakan perlakuan, serta bobot badan akhir, panjang dan bobot saluran pencernaan ayam kampung umur 63 hari. Hasil penelitian menunjukkan bahwa sifat fisik biochar limbah kulit kakao dan pakan perlakuan tidak berbeda nyata terhadap berat jenis. Hasil nilai kadar air yang berkisar antara 7,078%-10,78% dan aktivitas air yang berkisar antara 0,65-0,76 menunjukkan bahwa kadar air pada pakan penelitian ini masih dibawah standar dan aman untuk penyimpanan sesuai dengan standar SNI tahun 2013 yang menyatakan bahwa kadar air maksimum yaitu 14%, sedangkan nilai rataan aktivitas air, berat jenis dan ukuran partikel termasuk dalam kisaran normal. Pemberian pakan komersial, pakan mengandung biochar, dan pakan tanpa mengandung biochar tidak memberikan pengaruh pada panjang dan bobot saluran pencernaan ayam kampung., This study aimed to examine the physical properties of biochar from cocoa shell waste and its effect on the digestive tract of native chickens. A total of 160 selected Sentul native chicken DOCs were kept until harvest at 63 days (9 weeks), the sample used in this study consisted of 16 chickens consisting of 2 male chickens and 2 female chickens from each treatment. This study consisted of treatments P0 (commercial feed), P1 (research feed without biochar), P2 (research feed containing 1% biochar), and P3 (research feed containing 2% biochar). The experimental design used was a completely randomized design (CRD) with four treatments and four replications. Measurement of the observed variables included water content, water activity, specific gravity, particle size of biochar and treatment feed, as well as final body weight, length and weight of the digestive tract of native iv chickens aged 63 days. The results showed that the physical properties of cocoa husk waste biochar and treated feed were not significantly different with respect to specific gravity. The results of the water content values ranging from 7.078%- 10.78% and water activity ranging from 0.65-0.76 showed that the water content in the feed of this study was still below the standard and safe for storage according to the 2013 SNI standard which states that the maximum water content is 14%, while the average value of water activity, specific gravity and particle size are in the normal range. The treats of commercial feed, feed containing biochar, and feed containing non-biochar did not affected the length and weight of the digestive tract of native chickens.
Keyword: biochar, chicken digestive tract, cocoa shell, particle size

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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