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: Pengaruh Suplementasi Biochar Kulit Buah Kakao Terhadap Performa Ayam Kampung (Gallus gallus Domesticus)
Abstrak: Penelitian ini bertujuan untuk mengevaluasi pengaruh suplementasi biochar dari kulit buah kakao terhadap performa ayam kampung. Sebanyak 160 ayam Sentul terseleksi sejak umur sehari (DOC) telah dipelihara hingga dipanen pada umur 9 minggu. Penelitian ini terdiri dari 4 perlakuan yaitu P0 (pakan komersial sebagai kontrol positif), P1 (pakan penelitian tanpa biochar), P2 (pakan penelitian mengandung biochar 1%), dan P3 (pakan penelitian mengandung biochar 2%). Penelitian menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 4 ulangan. Peubah yang diamati yaitu bobot badan (BB), pertambahan bobot badan (PBB), konsumsi pakan, konversi pakan (FCR), income over feed and chick cost (IOFCC), dan juga mortalitas pada ayam kampung. Hasil penelitian menunjukkan bahwa suplementasi biochar sebanyak 1% dan 2% pada pakan tidak mempengaruhi performa ayam pada umur 9 minggu. Bobot badan pada penelitian ini memiliki hasil yang berkisar antara 830,00 g-931,70 g, kemudian nilai PBB yang dihasilkan berkisar antara 801,00 g-902,72 g, lalu konsumsi pakan yang dibutuhkan yaitu sebesar 3.788,46 g-3.832,38 g, sehingga nilai FCR berkisar antara 4,10-4,66. Perlakuan P0 memiliki nilai performa dengan hasil yang terbaik pada peubah BB, PBB, konsumsi, dan FCR, akan tetapi nilai IOFCC tertinggi dihasilkan oleh perlakuan P2 yaitu pakan penelitian dengan penambahan biochar 1% sebesar Rp2.484,35 per ekor dengan perolehan nilai performa yang mendekati perlakuan kontrol., This study aimed to examined the effects of biochar from cocoa shell waste as additive on feed concerning to the performances of native chickens. A total of 160 selected Sentul native chickens from the age of one day had been reared until they got harvested at the age of 63 days (9 weeks). This study consisted of 4 treatments, named P0 (commercial feed as positive control), P1 (feed contain non-biochar), P2 (feed contain 1% biochar), and P3 (feed contain 2% biochar). The experiment used was a completely randomized design (CRD) with four treatments and four designed replications. Measurement of the observed variables were included body weight, body weight gain, feed consumption, feed conversion rate (FCR), income over feed and chick cost (IOFCC), and also mortality percentage of native chickens. The results of this study indicated that the supplementation of 1% and 2% bio-charcoal in feed didn’t affected the chicken performances by the age of 63 days (9 weeks). The body weight in this research had resulted the range between 830.00 g-931.70 g, then body weight gain resulted the range between 801.00 g-902.72 g, then the feed consumption needed was ranged between 3,788.46 g-3,832.38 g, so the feed conversion rate resulted the range between 4.10-4.66. The treatment of P0 had the best performance result on the body weight, body weight gain, feed consumption, and feed conversion rate variable, while the highest IOFCC value was resulted by the treatment of feeding with 1% biochar, which was Rp2,484.35 per head with the performance value approached the control treatment value.
Keyword: biochar, native chicken, performance

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.
Keyword: