Judul: Uji Pemberian Paraquat, Difenoconazole DanButylphenylmethyl Carbamate (BPMC) Terhadap Emisi CO2 dan CH4, serta Perubahan Konsentrasi Asam-Asam Fenolat Di Tanah Gambut
Abstrak: Pesticides are widely used in agriculture land, including agricultural land with peat soil. The Study concerning pesticide and CO2 emission has not been done in Indonesia. The objectives of this study were to analyze the effect of paraquat, difenoconazole, butylphenylmethyl carbamate (BPMC) on CO2 and CH4 emission and concentration of phenolic acids in peat soil. The study was conducted at the Laboratory of Soil Chemistry and Fertility, Department of Soil Science and Land Resource, IPB. Soil Sample was collected in District of Pulang Pisau, Central Kalimantan. Peat soil was treated with paraquat, difenoconazole dan butylphenylmethyl carbamate (BPMC) and incubated for 24, 48, 96, 120 and 168 hours. The results showed that the application of pesticides at the recommendation rates increased CO2 emission compared to that of control. Concentration of total phenolic acid of all treatments decreased sharply compared to that of initial data where the concentration of total phenolic acids of treated ones were lower than those of control except BPMC. The results suggested that CO2 emission were from Carbon of degraded phenolic acid and pesticides. The application of pesticides with recommendation rate decreased CH4 emission compared to that of control.
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Judul: Pengaruh Pemberian Paraquat, Difenoconazol, dan BPMC (Buthylphenylmethyl Carbamate) Terhadap CO2 yang Dilepaskan dari Bahan Gambut dengan Inkubasi Tertutup dan Terbuka
Abstrak: The use of pesticides in agriculture is considered practically to eradicate the pests and plant diseases. However there are woried about the impact of environmental pollution on soil and water. In addition, other important environmental issues from the peat soil is carbon emissions. Peat soils have high organic carbon, so that when the carbon is lost through oxidation process, it will be speed up the release of the carbon emitted into the atmosphere. However, the organic material from peat soil is able to absorb the active materials of pesticides. Therefore, the application of pesticides in peat soils can be expected reduce the carbon release. This study aimed to find out the effect of Paraquat, Difenoconazol, and BPMC (Buthylphenylmethyl Carbamate) on CO2 release from Peat in the form of concentrations and fluxes Materials with Opened and Closed Incubation. Incubation time consists of 1 day, 2 days, 4 days, 5 days, and 7 days. The time was selected according with the retention of pesticides is less than 2 weeks. CO2 concentration and flux measurements is used by IRGA (Infrared Gas Analysis) type LI-802. Gases from a closed chamber flowed into the IRGA by using a pump and CO2 concentration directly read by IRGA every second for approximately 2,5 minutes. The study consisted of closed and opened incubation. In a closed incubation measured of CO2 concentrations, while the open incubation measured of CO2 flux . The results showed in the first seven days of closed incubation, can be increased of the CO2 concentration. In a closed incubation treatment of paraquat, difenoconazol, and BPMC CO2 concentration measured at 6.282,98 ppm, ppm 5.043,72, and 5.112,69 ppm. While control of soil is equal to 4.716,70 ppm. In the opened incubation treatment of paraquat, difenoconazol, and BPMC CO2 flux measured is 0,009 mg/m2/sec, 0,005 mg/m2/sec, and 0,015 mg/m2/sec and control of soil has 0,001 mg/m2/sec. The low rate application of pesticide has not impacted significantly on reducing CO2 concentrations and the relatively short time of application.
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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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