Judul: Pengetahuan, Sikap, dan Tindakan Petani Sayuran dalam Penggunaan Pestisida di Kabupaten Pandeglang, Banten.
Abstrak: Pesticide is common techniques used by farmers to control plant pests and diseases. Improper and excessive uses of pesticides often occur in pesticide application due to low farmer’s knowledge and skill. The aim of this study was to obtain information and analyze of the knowledge, attitude, and practice of vegetable farmers in pesticide use in Pandeglang Regency, Banten. This study has been conducted by using direct survey using structured questionnaires to obtain a primary data, while secondary data was obtained from local government and literature study. The survey location was determined by purposive sampling. The number of respondents were 150 vegetables farmers. The data was presented descriptively and analyzed using the χ2 (chi-square) test to analyze the relationship between each characteristic tested. Knowledge, attitude, and practices of vegetable farmers in Jiput, Pulosari, and Menes districts showed some differences. Generally, the farmers at Pulosari district have low rational attitude in the use of pesticides compared with two other districts. Many factors influence the knowledge, attitude, and practices of vegetable farmers in three districts in the use of pesticides. Based on the analysis and relationship tests, factors of age and income of farmers showed influence unsignificantly compared with two other variables such as education and participation of farmers in farmer groups.
Keyword: knowledge, pesticides types, plant pests and diseases, vegetable farmer

Judul: Knowledge and Practice of Rice Farmers in Pesticide Use in Lamongan Regency, East Java
Abstrak: Penggunaan pestisida merupakan cara yang umum dilakukan oleh petani untuk mengendalikan hama dan penyakit pada tanaman. Aplikasi pestisida harus mengikuti anjuran/rekomendasi yang telah ditentukan. Pengabaian anjuran penggunaan yang benar dapat menyebabkan berbagai dampak negatif. Penelitian ini bertujuan mengetahui tingkat pengetahuan dan tindakan petani padi dalam menggunakan pestisida di Lamongan, Jawa Timur. Penelitian dilaksanakan pada bulan Maret hingga Juni 2021. Penelitian dilakukan dengan metode survei langsung di lapangan menggunakan kuesioner terstruktur untuk mendapatkan data primer. Penentuan lokasi pengambilan contoh dilakukan secara terpilih (purposive) yang didasarkan pada populasi penduduk yang bekerja sebagai petani di tiga kecamatan terpilih lebih banyak daripada kecamatan lainnya. Jumlah petani responden sebanyak 60 petani yang tersebar di tiga kecamatan. Data yang diperoleh dianalisis secara deskriptif untuk mendeskripsikan tingkat pengetahuan dan tindakan petani dalam penggunaan pestisida. Analisis data menggunakan program Microsoft Excel yang disajikan dalam bentuk grafik dan tabulasi. Berdasarkan hasil survei, sebagian besar petani menggunakan pestisida sintetik karena dapat mengendalikan hama dan penyakit lebih cepat. Secara umum para petani memiliki pengetahuan yang baik dalam penggunaan pestisida, namun praktik yang dilakukan petani tidak sesuai dengan pengetahuan mereka. Hal ini dapat disebabkan oleh tingkat pendidikan dan pengalaman bertani responden.
Keyword: negative impact, pesticide use, pest and diseases

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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