Judul: Budidaya tebu (Saccharum officinarum L.) lahan kering di PG Madukismo PT Madubaru Yogyakarta dengan aspek khusus pemupukan beberapa kategori tanaman tebu lahan kering
Abstrak: The internship was conducted at PG Madukismo PG Madubaru Yogyakarta beginning 14 February 2012 to 15 Mei 2012. The special purpose is study fertilization of some category of upland sugarcane at PG Madukismo PT Madubaru Yogyakarta. Fertilization in PG Madukismo is important because one in order to achieve high productivity is a good fertilizer. Most of the fields in the PG Madukismo was upland. There are two types of cultivated sugar cane that is PC (Plant Cane) and RC (Ratoon Cane) Fertilizer used in PG Madukismo is the dose recommended by the P3GI and considered by PG Madukismo and farmers. Parties responsible for the extraction of manure from the barn to the application to sugarcane was foreman and field assistant. Dosage fertilizer for PC (Plant Cane) are 11 ku/ha Madros, 5 ku/ha ZA and 5 ku/ha Phonska while for RC (Ratoon Cane) are 5 ku/ha ZA and 5 ku/ha Phonska. The data obtained were analyzed using t-test. From the results obtained for plants PC or RC I obtained the best productivity of sugarcane grown on land that has a typology mild soil type, irrigation well (pump) and the current drainage there are Kledokan field in Magelang which have productivity 598 ku /ha and Sikendal field in Temanggung which have productivity 693 ku/ha.
Keyword: 

Judul: Sugarcane Management (Saccharum officinarum L.) at Madukismo Sugar Factory with Special Aspects Inorganic Fertilization Efficiency
Abstrak: Gula merupakan salah satu komoditas penting yang keberadaannya sangat dibutuhkan dari skala rumah tangga sampai skala industri. Budidaya tebu yang baik akan berpengaruh terhadap produksi gula yang optimal. Pupuk menjadi salah satu input penting dalam kegiatan budidaya tebu, sehingga aplikasi dosis pemupukan harus dilakukan dengan baik sehingga menciptakan efisiensi yang diinginkan. Magang ini bertujuan meningkatkan kemampuan profesional dalam memahami proses kerja nyata dan menganalisis efisiensi pemupukan anorganik pada budidaya tebu lahan kering. Dilaksanakan di PT Madubaru PG Madukismo, Bantul, Kasihan, Yogyakarta dari 24 Januari sampai 24 Mei 2022. Dosis pemupukan yang dilakukan tidak berbeda nyata pada ketiga varietas (PS 862, KK, dan BL). Nilai efisiensi teknis tertinggi terdapat pada kebun dengan varietas BL dengan dosis total pupuk 940 kgha-1, setiap satu kg pupuk efisien terhadap peningkatan 0,654 ku hasil. Efisiensi biaya menurut analisis usaha tani menunjukkan bahwa kebun dengan varietas BL paling efisien dengan nilai R/C 1.47.
Keyword: dosis pemupukan, efisiensi pemupukan, nilai R/C

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: