Judul: Uji Efikasi Ekstrak Tanaman Suren ( Toona sinensis Merr.)  Sebagai Insektisida Nabati Dalam Pengendalian Hama Daun  (Eurema spp. dan Spodoptera litura F.)
Abstrak: Indonesia kaya akan keanekaragaman hayati (biodiversity) termasuk jenis tumbuhan yang mengandung bahan aktif pestisida, bahkan terdapat lebih dari 1.100 jenis tumbuhan yang mengandung bahan insektisida. Salah satu tumbuhan yang berpotensi untuk dikembangkan sebagai bahan insektisida nabati dalam pengendalian hama daun adalah genus Toona (suren) yang termasuk famili Meliaceae dan belum banyak dimanfaatkan. Penggunaan insektisida sintetik dalam pengendalian hama memiliki beberapa keunggulan, diantaranya dapat mengendalikan hama sasaran dengan cepat. Selain memiliki keuntungan, penggunaan insektisida sintetik juga dapat menimbulkan dampak negatif, diantaranya dapat menyebabkan resistensi dan resurjensi hama, terbunuhnya musuh alami dll. Dampak negatif insektisida sintetik memicu reaksi balik masyarakat yang pada akhirnya memunculkan sikap keraguan terhadap insektisida sintetik. Keraguan tersebut menyebabkan orang mencari cara atau sarana pengendalian alternatif yang lebih aman.
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Judul: Critical Review of the Potential of Preparations of Twenty Species from Fourteen Plant Families for Crop Pest Control
Abstrak: Serangan hama tanaman dapat menimbulkan kerugian yang besar sehingga harus dikelola dengan tindakan pengendalian yang tepat. Insektisida sintetik yang sering digunakan petani dapat menyebabkan berbagai dampak samping yang tidak diinginkan terhadap organisme bukan sasaran dan lingkungan. Insektisida nabati merupakan salah satu alternatif potensial untuk mengendalikan hama tanaman. Kajian pustaka ini dilakukan untuk meninjau secara kritis publikasi tentang sediaan insektisida nabati 20 spesies dari 14 famili tumbuhan. Potensi insektisida nabati tersebut dievaluasi berdasarkan ketersediaan, kefektifan, keamanan terhadap organisme bukan sasaran, dan potensi pemasyarakatannya. Publikasi daring yang relevan ditelusuri melalui database seperti Google, Google Scholar, ResearchGate, PubMed, National Center for Biotechnology Information, dan IPB Repository, dengan tambahan beberapa materi cetak. Hasil analisis literatur menunjukkan bahwa di antara 20 spesies tumbuhan yang dievaluasi, hanya 5 spesies yang ekstrak pelarut organik atau minyak atsirinya memiliki bioaktivitas yang sangat kuat terhadap setidaknya satu spesies hama sasaran. Kelima spesies tumbuhan tersebut ialah Allium sativum, Azadirachta indica, Curcuma longa, Dysphania ambrosioides, dan Nicotiana tabacum. Sementara itu, sediaan A. sativum, A. indica, dan Citrus limon yang disiapkan dengan pelarut air juga memiliki aktivitas insektisida yang sangat kuat. Data yang tersedia menunjukkan bahwa insektisida nabati aman bagi organisme bukan sasaran dan lingkungan. Peningkatan penggunaan insektisida nabati dapat dilakukan dengan mengintegrasikan pemasyarakatan dan penggunaannya dalam program pengelolaan hama yang relevan., Crop losses due to pest organisms can be substantial and should be managed by applying proper crop protection measures. Synthetic insecticides commonly used by farmers could cause some undesirable side effects to non-target organisms and the environment. Botanical insecticides represent one of the potential alternatives to synthetic insecticides for controlling crop pests. This literature study was carried out to critically review published papers on botanical insecticide preparations of 20 species from 14 plant families. Those botanical insecticides were assessed based on their availability, effectiveness, safety to non-target organisms, and dissemination potential. Relevant publications were searched through online databases such as Google, Google Scholar, ResearchGate, PubMed, National Center for Biotechnology Information, and IPB Repository, in addition to some printed materials. Results of the literature analysis showed that among the 20 plant species studied, only 5 species yielded organic solvent extracts or essential oils that had very strong insecticidal activity against at least one target pest species. Those five plant species were Allium sativum, Azadirachta indica, Curcuma longa, Dysphania ambrosioides, and Nicotiana tabacum. Meanwhile, A. sativum, A. indica, and Citrus limon aqueous extracts also had very strong insecticidal activity. Available data indicated that botanical insecticides are safe to nontarget organisms and the environment. Enhancement of use of botanical insecticides can be done by integrating their dissemination and use in relevant pest management programs.
Keyword: botanical insecticides, crop pests, feasibility, safety, dissemination

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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