Judul: Greenhouse Gas Emissions from Beef Cattle  Manure in Semangke Hamlet, Jenu District, Tuban Regency
Abstrak: Emisi gas rumah kaca (GRK) merupakan salah satu penyebab utama perubahan iklim. Peternakan, dengan kontribusi besar terhadap emisi GRK seperti CO2, CH4 dan N2O, turut berperan dalam masalah ini. Penelitian ini fokus pada emisi metana (CH4) yang dihasilkan oleh peternakan sapi potong di Dusun Semangke, Kecamatan Jenu. Menggunakan metode IPCC AFOLU Tier-2, total populasi ternak sebanyak 32,05 satuan ternak di Dusun Semangke diperkirakan dapat menghasilkan emisi GRK sebesar 23,00 Gg CO2-e tahun-1 . Emisi tersebut terdiri dari tiga komponen utama: fermentasi methan fermentasi entirik sebesar 22,31 Gg CO2-e tahun-1 , emisi methane dari pengelolaan ternak sebesar 0,67 Gg CO2-e tahun-1 , dan emisi N2O dari pengelolaan kotoran sebesar 0,02 Gg CO2-e tahun-1 , Meskipun demikian, sektor pertanian di Dusun Semangke memiliki kapasitas penyerapan karbon sebesar 1239,50 Gg CO2-e tahun-1 , yang melebihi emisi yang dihasilkan dari populasi ternaknya. Bersasarkan surplus serapan karbon sebesar 1216,50 Gg CO2-e tahun-1 , dapat disimpulkan bahwa kondisi ini bisa terus ditingkatkan melalui program mitigasi seperti manajemen pakan, pengelolaan kotoran dan penanaman hijauan pakan., Greenhouse gas (GHG) emissions are one of the main drivers of climate change. With significant contributions to GHG emissions such as CO2, CH4, and N2O, livestock play a role in this issue. This study focused on methane (CH4) emissions from beef cattle farming in Semangke Hamlet, Jenu Sub-district. Using the IPCC AFOLU Tier-2 method, the total livestock population of 32,05 livestock units in Semangke Hamlet emitted 23,00 Gg CO2-e year-1 of GHGs. These emissions consisted of three main components: enteric fermentation methane emissions of 22,31 Gg CO2-e year-1 , methane emissions from livestock management of 0,67 Gg CO2-e year-1 , and N2O emissions from manure management of 0,02 Gg CO2-e year-1 . Despite this, the agricultural sector in Semangke Hamlet has a carbon sequestration capacity of 1239,50 Gg CO2-e year-1 , which exceeds the emissions generated by its livestock population. With a carbon sequestration surplus of 1216,50 Gg CO2-e year-1 , it can be concluded that this condition can be further improved through mitigation programs such as feed management, manure management, and forage planting.
Keyword: beef cattle, IPCC, greenhouse gas, Tier 2

Judul: Pendugaan emisi gas metan dan dinitrogen oksida dari berbagai jenis ternak di Kabupaten Bogor
Abstrak: The aim of these research was to observe the level of emission greenhouse gases from livestock sector in Bogor Regency. Various animal species used in this research were dairy cow, beef cattle, buffalo, swine, horse, and poultry. Data of livestock’s population in Bogor Regency were used for basic calculation. The data were collected from literature and direct observation collection through survey of animal characterization and manure management, inventory equation of emission greenhouse gas based on Intergovernmental Protocol of Climate Change (IPCC). Data were processed by Microsoft Excel. Model of calculation consist of model I and model II. Model I used IPCC default data, meanwhile model II used literature and survey data. Methane and dinitrogen oxide which was produce from livestock converted into carbon dioxide based on value of Global Warming Potential (GWP). The greenhouse gases emission in Bogor Regency were 201.46 Gg CO2 eq by model I and 170.21 Gg CO2 eq by model II. Animal which was produced GHG from the highest to the lowest by (model I and model II) were sheep (33% and 39%), dairy cow (21% and 9%), buffalo (16% and 18%), goat (12% and 17%), beef cattle (10%), poultry (6% and 7%), swine (1% and 0%), and horse (0%). The highest level of greenhouse gases emission was produced by Pamijahan District as many as 17.63 Gg CO2 eq (8.75%) by model I and 12.1 Gg CO2 eq (7.03%) by model II.
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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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