Judul: Efikasi Sipermetrin Terhadap Larva Caplak Anjing (Rhipicephalus sanguineus
Abstrak: The usage of dogs among the people of Indonesia is currently increasing. Usually, dogs are used as playmate, guard and police partner. Ectoparasite that often cause problem in dog was Rhipicephalus sanguineus ticks. Cypermethrin insecticide is a chemical that can be used to control of ticks on dogs. Ticks larvae were divided into 4 treatment groups and one control group. Each group was divided into 3 repititions with the number of ticks larvae were 20 per repeated. The concentration for each treatment group were 0.5 g/L, 1 g/L; 1.5 g/L, 2 g/L, and a control group using water. Fabric drabbled with different concentrations of cypermethrin were prepared and the ticks larvae were put on it. Observation on larval mortality was done on 1, 2, 3, 4, 5, 6, 12, 24, and 48 hours post treatments. The result showed that the effective concentration of cypermethrin was 2 g/L, because this concentration was able to kill 93.33% of tick larvae at 24 hours post treatment.
Keyword: Rhipicephalus sanguineus, larvae, insecticide, ectoparasites, Cypermethrin

Judul: Efikasi Larutan Cuka Apel sebagai Insektisida terhadap Larva Caplak Anjing (Ixodidae: Rhipicephalus sanguineus)
Abstrak: Caplak Rhipicephalus sanguineus merupakan satu di antara jenis ektoparasit yang kerap ditemukan menyerang anjing. Penggunaan bahan alami yang berpotensi membunuh caplak pada anjing dan lingkungan merupakan hal yang perlu diteliti. Penelitian ini bertujuan (1) menentukan efikasi larutan cuka apel sebagai bioinsektisida terhadap larva caplak anjing (Rhipicephalus sanguineus) (2) menentukan dan menganalisis konsentrasi optimum dari pemberian larutan cuka apel yang dapat mematikan larva caplak. Larva caplak yang digunakan berasal dari hasil penetasan caplak dewasa kenyang darah di laboratorium. Larva caplak dibagi ke dalam 4 kelompok perlakuan (5%, 10%, 15%, dan 20%) dan 2 kelompok kontrol positif (fipronil) dan negatif (aquadest). Setiap kelompok terdiri atas 4 pengulangan dengan total 20 larva tiap pengulangan. Cara pengujian dilakukan dengan mencelupkan larva caplak yang telah dibungkus dalamkain linen ke dalam setiap konsentrasi selama 1 menit. Pengamatan terhadap kematian larva caplak dilakukan pada jam ke-1, 2, 3, 4, 5, 6, 12, 24, dan 48 jam pasca perlakuan. Hasil penelitian menunjukkan larutan cuka apel pada konsentrasi berbeda-beda berpengaruh secara signifikan terhadap kematian larva caplak anjing. Semakin tinggi persentase konsentrasi kadar larutan cuka apel, maka semakin cepat dan tinggi jumlah larva caplak yang mengalami kematian. Hasil analisis statistik menunjukkan konsentrasi optimum larutan cuka apel yang efektif mematikan larva caplak adalah larutan cuka apel 20%. Angka rata-rata kematian larva caplak tersebut adalah sebesar 93,75% pada 12 jam dan 100% pada 24 jam pasca perlakuan. Nilai lethal time 50 pada larutan cuka apel 3,5 jam, sedangkan lethal time 90 sebesar 14,7 jam.
Keyword: Apple vinegar, bioinsecticide, tick larvae, Rhipicephalus sanguineus

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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