Judul: Harvest Characteristics of Cucumber (Cucumis sativa L.) in Glasshouse at Tuinderij Hoevekestein BV, The Netherlands
Abstrak: Cucumber (Cucumis sativa L.) is an of important vegetable crop in Indonesia, yet it faces many challenges. The main challenges include low productivity, low quality, and high loss-rate after harvest. Therefore, better knowledge about cucumber cultivation as well as post-harvest management is of great importance. The objective of this internship was to gain experience and skill both in technical and managerial abilities in an agricultural enterprise. The specific objective of the internship was to study about harvest characteristics of cucumber (Cucumis sativa L.) in glasshouse at Tuinderij Hoevekestein BV. The study focus on this internship was the effect of different glasshouses condition on harvest characteristics. Quantitative data for harvest characteristics was analyzed by F-test followed by Tukey’s test. Two cucumber varieties: Proloog and Lausanna, were grown in three glasshouse. The data showed that cucumbers grown in glasshouse 1 had higher fruit-length, -diameter, and –weight than those grown in glasshouse 2 and 3. Glasshouse 1 differ from the other two glasshouse in glasshouse size. Qualitative analysis showed that all samples on both varieties was included in 1st class. Generally, Tuinderij Hoevekestein BV performs a good production to be marketed.
Keyword: CO2 concentration, cultivation, internship, production, vegetables

Judul: Performance of 20 Cucumber Varieties (Cucumis Sativus) in Indonesia.
Abstrak: Salah satu sayur yang banyak dikonsumsi di Indonesia dalam bentuk segar adalah mentimun (Cucumis sativus L.). Peningkatan produktivitas dan keragaman hasil panen merupakan dua strategi yang digunakan untuk mendongkrak produksi mentimun untuk memenuhi kebutuhan masyarakat. Penelitian ini bertujuan melihat keragaan kualitatif dan kuantitatif berbagai varietas di Indonesia. Penelitian dilaksanakan di Kebun Percobaan Leuwikopo Institut Pertanian Bogor pada bulan Maret 2021 sampai Mei 2022. Percobaan menggunakan rancangan kelompok lengkap teracak (RKLT) satu faktor yaitu varietas dengan empat ulangan dan dihasilkan 80 satuan percobaan. Hasil analisis sidik ragam menunjukkan bahwa perlakuan berpengaruh nyata dan sangat nyata terhadap 19 karakter kuantitatif diantaranya panjang biji, lebar biji, tebal biji, panjang 15 buku pertama, panjang batang satu ruas, diameter ruas batang, panjang dan lebar daun, panjang dan lebar bakal buah, bobot buah masak konsumtif, panjang dan diameter buah masak konsumtif, rasio panjang dan diameter buah, panjang leher buah masak konsumtif, panjang dan tebal tangkai buah masak konsumtif, dan ketebalan daging buah masak konsumtif. Hasil analisis juga menunjukkan adanya perbedaan di antara 19 karakter genotipe mentimun yang telah diuji.
Keyword: seed, fruit, genetic relationship

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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