Judul: Growth Responses of 5 Rambutan Varieties (Nephelium lappaceum L.) to Addition of Artificial Light LED (Light Emitting Diode)
Abstrak: Rambutan (Nephelium lappaceum L.) merupakan buah yang cocok ditanam di daerah tropis dan Indonesia menjadi negara dengan plasma nutfah terbesar di dunia. Menjaga kekayaan hayati ini perlu adanya teknik baru untuk memperbanyak dan mengoptimalkan pertumbuhan tanaman rambutan. Penelitian ini menggunakan rancangan petak tersarang (nested) dua faktor yaitu cahaya LED (Light Emitting Diode) dan varietas. Cahaya LED yang digunanakan yaitu merah, biru, dan putih sedangkan varietas yang diteliti Sikoneng, Parakan, Cilebak, Kerikil, dan Garuda. Tanaman rambutan yang diberi tambahan LED biru memiliki kandungan klorofil dan gula daun yang lebih tinggi sedangkan LED merah dapat menpengaruhi pertumbuhan morfologi seperti tinggi tanaman, diameter batang, dan ukuran daun. LED merah berperan dalam proses pemanjangan dan penguatan sel sehingga daun menjadi lebih tebal. Penambahan LED putih dapat memunculkan banyak senyawa metabolit pada dua varietas yaitu Garuda dan Parakan tetapi, penambahan LED putih 1- 4 µmol m-2 s-1 dapat menyebabkan stres pada tanaman sehingga tanaman mengalami kematian dan rontok daun. Varietas Garuda lebih tahan dan lebih baik pertumbuhanya dibandingkan dengan varietas lain., Rambutan (Nephelium lappaceum L.) is a fruit that planted in tropical areas and Indonesia is the country with the largest germplasm in the world. Maintaining this biological wealth requires new techniques to reproduce and optimize the growth of rambutan plants. This study used a two-factor nested design, namely LED (Light Emitting Diode) and varieties. The LED light source were red, blue, and white, while the varieties studied included Sikoneng, Parakan, Cilebak, Kerikil, and Garuda. Rambutan plants that are given additional blue LEDs have higher chlorophyll and leaf sugar content while red LEDs can affect morphological growth such as plant height, stem diameter, and leaf size. Red LED plays a role in the process of elongation and strengthening of cells so that the leaves become thicker. The addition of white LEDs can generate many metabolite compounds on two varieties, namely Garuda and Parakan, but the addition of 1- 4 µmol m-2 s-1 white LEDs can cause stress on plants so that plants experience death and leaf loss. Garuda variety is more resistant and grows better than other varieties
Keyword: chlorophyll, glucose, LEDs, Nephelium lappaceum L., secondary metabolite, Varieties

Judul: The Influence of Differences in Spectrum and Intensity of Artificial Light on the Growth of Jackfruit (Artocarpus heterophyllus Lam.) Kandel Cultivar in Nurseries.
Abstrak: Nangka (Artocarpus heterophyllus Lam.) dikenal sebagai salah satu buah terbesar di dunia yang dapat dimakan dan bernilai gizi tinggi. Pada awalnya, nangka dikategorikan sebagai tanaman buah lokal yang kurang dimanfaatkan. Namun, saat ini nangka semakin mendapatkan popularitas secara global. Upaya peningkatan pertumbuhan tanaman harus dilakukan untuk mendukung permintaan pasar salah satunya dengan rekayasa lingkungan. Penelitian ini bertujuan untuk mengetahui respons morfologi, fisiologi, dan anatomi bibit nangka terhadap perbedaan spektrum dan intensitas cahaya buatan LED (Light Emitting Diode). Penelitian ini dilaksanakan berdasarkan Rancangan Acak Lengkap (RAL) dua faktor, yaitu spektrum LED (ungu dan putih) dan intensitas cahaya (dua dan empat lampu). Penambahan LED pada pembibitan nangka dapat memengaruhi respons morfologi, fisiologi, dan anatomi. LED ungu dengan intensitas tinggi (PH) berpengaruh positif terhadap laju pertumbuhan tinggi tanaman, jumlah cabang, diameter batang, dan konduktansi stomata. LED putih dengan intensitas tinggi (WH) memiliki pengaruh positif terhadap kandungan klorofil, pertumbuhan dan perkembangan daun. Perlakuan dengan intensitas cahaya yang tinggi memiliki pengaruh positif terhadap jumlah stomata, bukaan stomata, kerapatan stomata, dan ketebalan daun., Jackfruit (Artocarpus heterophyllus Lam.) is known as one of the largest edible fruits in the world with high nutritional value. Initially, jackfruit was categorized as an underutilized local fruit plant. However, it is now gaining global popularity. Efforts to enhance plant growth must be made to support market demand, one of which is through environmental engineering. This study aims to determine the morphological, physiological, and anatomical responses of jackfruit seedlings to different spectra and intensities of artificial LED (Light Emitting Diode) light. This research was conducted based on a Completely Randomized Design (CRD) with two factors: LED spectrum (purple and white) and light intensity (two and four lamps). The addition of LEDs in jackfruit seedling nurseries can affect morphological, physiological, and anatomical responses. High-intensity purple LEDs (PH) positively influence the growth rate of plant height, number of branches, stem diameter, and stomatal conductance. High-intensity white LEDs (WH) positively impact chlorophyll content, leaf growth, and development. High light intensity treatments positively influence the number of stomata, stomatal aperture, stomatal density, and leaf thickness.
Keyword: clorophyll, full-spectrum LEDs, glucose, photosynthesis, stomata

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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