Judul: Boophilus microplusin beef cattle livestock at Jonggol  and  effectiveness  of  malation  and  deltametrin  to  these  ticks
Abstrak: Boophilus microplus merupakan ektoparasit pengisap darah yang penting pada sapi karena dapat menyebabkan anemia dan merupakan vektor dari babesiosis dan anaplasmosis. Penelitian ini bertujuan untuk mengetahui kepadatan larva caplak B. microplusdi peternakan sapi potong daerah Jonggol, Kabupaten Bogor serta uji efikasinya terhadap insektisida malation dan deltametrin. Pengamatan terhadap kepadatan larva caplak B. microplus dilakukan pada pagi hari dan menunjukkan hasil yang tinggi pada area yang telindungi dari sinar matahari. Caplak B. microplus yang dikoleksi dari lapangan dipelihara hingga bertelur dan menetas menjadi larva. Sebanyak 20 larva caplak B. microplus diletakan pada cawan petri yang berisikan kertas saring untuk diuji efikasinya terhadap malation dan deltametrin dengan metode spraying pada konsentrasi 2 g/L, 1.5 g/L, 1 g/L dan 0.5 g/L dan dilakukan tiga kali ulangan. Hasil pengujian menunjukkan kejatuhan larva yang cepat pada malation dan angka kejatuhan larva yang berfluktuasi pada pengujian dengan deltametrin. Kedua insektisida tersebut menyebabkan kematian larva lebih dari 90% pada jam ke-24 pengamatan, Boophilus microplus is one of significant blood-sucking ectoparasites in cattle because of its ability for causing anemia and also as a vector of babesiosis and anaplasmosis. The objective of this study were to determine the density of B. microplus ticks larvae in beef cattle livestock located at Jonggol, Bogor District. The effectiveness of two classes of insecticide (malation and deltametrin) to these tick were conducted also. Observation of B. microplus larvae density was conducted in the morning and showed a high density on area that unrevealed to the sunlight. B. microplus that have been collected from field were reared until laid eggs and hatched into larvae to tested in vitro against malation and deltametrin using spraying method in concentrations 2 g/L, 1.5 g/L, 1 g/L and 0.5 g/L. Testing conducted as much as three repetition on each group of 20 ticks larvae which were placed inside the insecticide impregnated paper. The result showed a rapid rate of knock down of larvae on testing with malation and the fluctuative knock down rate on testing with deltametrin. Both of insecticide caused more than 90% larval mortality at the 24 th hour of observation
Keyword: Boophilus microplus, deltametrin, efikasi insektisida, kepadatan larva, malation

Judul: Efektivitas insektisida terhadap larva caplak sapi (Boophilus microplus) peternakan sapi potong di Jonggol Kabupaten Bogor
Abstrak: Boophilus microplus cattle tick is important ectoparasites of cattle, especially because of its hematophagous and also as vector of babesiosis and anaplasmosis. Application of chemical insecticide is still mostly done for control these tick. This study aimed to determine the efficacy of cypermethrin and propoxur as larvicides to B. microplus larvae. Field observation was also conducted to determine the prevalence, degree of ticks infestation, as well as the distribution of ticks infestations in cattle body region, i.e head and neck, abdomen, back, legs, and tail. Tick eggs from field collection were hatched to be larvae and tested in vitro to cypermethrin and propoxur in gradual concentrations 0.5 g/L, 1 g/L, 1.5 g/L, and 2 g/L. Testing conducted as much as three repetition on each group of 20 ticks larvae which were placed inside the insecticide impregnated paper. Observation of knockdown time (KT) were held for 6 hours then 24 hours for tick larvae mortality. Efficacy test showed 100% tick larvae were death at the 24th hour on all treatments. Based on these results, cypermethrin and propoxur stated effective to B. microplus larvae. Field observation showed the prevalence of B. microplus infestation in the amount of 46.88%, with the highest infestation obtained in the region of the head and neck (38.02%) and the lowest in the region of the tail (4.15%).
Keyword: Bogor Agricultural University (IPB), propoxur, efficacy of insecticides, cypermethrin, Boophilus microplus

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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