Judul: Response of Shade and Fertilizer Dosage on Growth and  Yield of Katuk (Sauropus androgynus (L.) Merr.).
Abstrak: Katuk (Sauropus androgynus (L.) Merr.) adalah salah satu jenis sayuran indigenous di Indonesia yang memiliki potensi untuk dikembangkan sebagai sayuran alternatif untuk memenuhi kebutuhan nutrisi. Penelitian ini bertujuan untuk mengetahui pengaruh intensitas naungan dan dosis pupuk yang sesuai guna meningkatkan pertumbuhan dan hasil produksi katuk. Percobaan dilakukan menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) faktor Split plot dengan petak utama adalah naungan dan anak petak adalah dosis pemupukan. Intensitas naungan terdiri dari 4 taraf, yaitu N0 (tanpa naungan), N1 (naungan 55%), N2 (naungan 65%), dan N3 (naungan 75%). Dosis pemupukan juga terdiri dari 4 taraf, yaitu P1 (50 kg ha-1), P2 (100 kg ha-1), P3 (150 kg ha-1), dan P4 (200 kg ha-1). Penelitian dilakukan dengan 3 ulangan sehingga diperoleh 16 kombinasi, dengan 48 satuan percobaan. Hasil penelitian menunjukkan tidak terdapat interaksi antara naungan dan dosis pemupukan. Perlakuan tunggal dosis pemupukan tidak memberikan pengaruh terhadap seluruh parameter pengamatan. Perlakuan naungan berpengaruh terhadap seluruh peubah pengamatan kecuali pada diameter batang saat pengamatan 2 MST dan 3 MST. Bobot panen komersial yang dipanen pada 8 MST mencapai hasil optimum pada aplikasi naungan 65%. Kata kunci: paranet, sayuran indigenous, dan sayuran komersial, Katuk (Sauropus androgynus (L.) Merr.) is one of the indigenous vegetables in Indonesia which has the potential to be developed as an alternative vegetable to meet nutritional needs. This study aims to determine the effect of shade intensity and appropriate dose of fertilizer to increase growth and yield of katuk production. The experiment was carried out using a completely randomized block design (RKLT) with split plot factors with the main plot being shaded and sub-plots being the dose of fertilization. Shade intensity consisted of 4 levels, namely N0 (without shade), N1 (55%), N2 (65%), and N3 (75% shade). The fertilization dose also consisted of 4 levels, namely P1 (50 kg ha-1), P2 (100 kg ha-1), P3 (150 kg ha-1), and P4 (200 kg ha-1). The study was conducted with 3 replications so that 16 combinations were obtained, with 48 experimental units. The results showed that there was no interaction between shade and fertilization dose. Single treatment of dose fertilization did not give effect on all parameter of observation. Shade treatment affected all observation variables except for stem diameter at 2 WAP and 3 WAP. Commercial harvest weights harvested at 8 WAP achieved optimum yields at 65% shading applications. Keywords: commercial vegetable, indigenous vegetable, and paranet
Keyword: commercial vegetable, indigenous vegetable, paranet

Judul: Effect of Fertilization Dosage on Growth and  Production of Katuk (Sauropus androgynus) Cuttings Using Fertigation Through  Drip Irrigation
Abstrak: Keberadaan tanaman indigenous dapat menambah pilihan jenis sayuran sebagai konsumsi masyarakat. Salah satu tanaman yang masuk dalam tanaman indigenous adalah katuk. Untuk menunjang pertumbuhan tanaman katuk yang maksimal diperlukan adanya aplikasi pemupukan dan penyiraman yang efisien. Penelitian ini bertujuan mengetahui dosis pemupukan yang optimal pada budidaya katuk. Kegiatan penelitian dilaksanakan mulai bulan November 2022 hingga April 2023 di Kebun Percobaan Leuwikopo. Percobaan dilakukan dengan metode rancangan kelompok lengkap teracak sebanyak tiga kali ulangan. Penelitian terdiri dari faktor tunggal yaitu dosis pupuk N, P, dan K dengan lima taraf dosis (0%, 50%, 100%, 150%, 200%). Hasil penelitian menunjukkan bahwa pengaruh dari pemupukan tidak memberikan respon yang nyata, kecuali pada peubah tinggi cabang pada umur tanaman 10-13 MST. Meskipun tidak berpengaruh nyata, terdapat indikasi bahwa bobot basah, bobot daun, dan produktivitas total akan meningkat seiring peningkatan dosis pupuk yang diberikan., The existence of indigenous plants can increase the choice of vegetables for public consumption. One of the indigenous plants is katuk. To support the maximum growth of katuk plants, efficient fertilization and watering applications are needed. This study aims to determine the optimal dose of fertilization in katuk cultivation. Research activities were carried out from November 2022 to April 2023 at the Leuwikopo Experimental Garden. The experiment was conducted using a randomized complete group design method with three replications. The research consisted of a single factor, namely the dose of N, P, and K fertilizers with five dose levels (0%, 50%, 100%, 150%, 200%). The results showed that the effect of fertilization did not give a real response, except for the variable of branch height at plant age 10-13 weeks after planting. Although not significantly affected, there are indications that wet weight, leaf weight, and total productivity will increase as the dose of fertilizer applied increases.
Keyword: indigenous vegetables, inorganic fertilizer, productivity

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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