Judul: Kecapi Seedlings (Sandoricum koetjape Merr.) Growth Response Under Different Spectrum and Intensities of Light Emitting Diode
Abstrak: Kecapi (Sandoricum koetjape Merr.) merupakan buah lokal dari famili Meliaceae yang sudah jarang dibudidayakan. Harga pasar buah ini tidak stabil akibat produksi dan kualitas tidak konsisten. Untuk memperbaiki sistem budidaya tanaman buah ini dapat dilakukan dengan modifikasi lingkungan yaitu penggunaan LED (Light Emitting Diode) sebagai cahaya buatan. Penelitian ini bertujuan mengetahui perubahan respons morfologi, fisiologi, dan anatomi terhadap perbedaan spektrum dan tingkat intensitas cahaya LED. Penelitian dilaksanakanberdasarkan Rancangan Acak Lengkap (RAL) dua faktor terdiri dari spektrum LED (ungu dan putih) dan intensitas cahaya (dua dan empat lampu). Hasil penelitian menunjukkan respons morfologi dan fisiologi terbaik pada perlakuan LED putih intensitas tinggi (WH). LED putih intensitas rendah (WL) meningkatkan kandungan klorofil daun dan laju fotosintesis. Respons anatomi terbaik pada perlakuan LED ungu intensitas rendah (PL). Peningkatan lebar daun pada LED ungu intensitas tinggi (PH). Kandungan glukosa menurun pada semua perlakuan dan peningkatan kandungan fruktosa hanya terjadi pada perlakuan LED ungu dengan intensitas rendah., Kecapi (Sandoricum koetjape Merr.) is a local fruit from the Meliaceae family that is rarely cultivated. The market price of this fruit is unstable due to inconsistent production and quality. Improving the cultivation system of this fruit plant can be done by modifying the environment, the use of LED (Light Emitting Diode) as artificial light. This study aims to determine changes in morphological, physiological, and anatomical responses to different spectra and intensity levels of the LED light. The research was conducted based on a two-factor completely randomized design (CRD) consisting of LED spectrum (purple and white) and light intensity (two and four lights). The results showed the best morphological and physiological responses in the treatment of high-intensity white LED (WH). Low-intensity white LED (WL) increased leaf chlorophyll content and photosynthesis rate. The best anatomical response was in the low-intensity purple LED (PL) treatment. Increased leaf width in high-intensity purple LED (PH). Leaf glucose content decreased in all treatments and an increase in fructose content only occurred in the low-intensity purple LED treatment.
Keyword: chlorophyll, glucose, intracellular CO2, photosynthesis, stomata

Judul: Response of Physiology and Growth Water Rose Apple (Syzygium aqueum) under Differences Intensities and Spectrum of Artificial Light Emitting Diode
Abstrak: Aplikasi 4 LED ungu + strip LED merah mampu meningkatkan pertumbuhan jumlah pucuk, tinggi tanaman, jumlah cabang, panjang ruas, diameter ruas, mempercepat waktu muncul pucuk pertama, namun tidak pada waktu perluasan daun. Perlakuan 4 LED ungu + strip LED biru mampu meningkatkan jumlah daun, panjang daun, dan lebar daun. Perlakuan 2 LED putih mampu meningkatkan diameter batang. Perlakuan 2 LED ungu + strip LED merah meningkatkan kandungan klorofil a dan klorofil b, sementara itu rasio klorofil a/b pada perlakuan 4 LED ungu + strip LED merah. Pada perlakuan 4 LED ungu + strip LED merah meningkatkan sintesis glukosa dan fruktosa paling banyak pada daun. Akumulasi kadar hara N, P, Mg, S, Fe, Cu, Zn, dan B dominan turun hampir di semua perlakuan, namun pada hara K, C-organik, Ca, Na, Mn, dan C/N rasio mengalami peningkatan. Perlakuan 4 LED ungu + strip LED merah mampu meningkatkan jumlah stomata, kerapatan stomata, bukaan stomata, laju transpirasi, laju fotosintesis, CO2 intraseluler dan konduktansi stomata, namun ketebalan daun pada perlakuan 4 LED putih + strip LED biru. Dominansi metabolit sekunder yang terbentuk dari penambahan LED berasal dari kelompok senyawa phenylpropanoids. LED biru meningkatkan produksi metabolit sekunder di daun jambu air dibandingkan perlakuan LED merah. Dengan demikian dari penelitian ini dominansi cahaya merah mampu meningkatkan pertumbuhan dan aspek fisiologis bibit jambu air., Results showed that 4 purple LED + red strip supported flush amount growth, crop height, branch amount, internode length, internode diameter, first leaf time flushing, but not leaf expansion time. 4 purple LED + blue strip increased leaves amount, leaf length, leaf width. 2 white LED enhanced stem diameter. 2 purple LED + red strip promoted chlorophyll-a and b synthesis, meanwhile ratio a/b synthesis in 4 purple LED + red strip. 4 purple LED + red strip synthesized more glucose and fructose. Almost all LED treatments showed reduction in N, P, Mg, S, Fe, Cu, Zn, and B content, but not in K, C-org, Ca, Na, Mn, and C/N ratio. 4 purple LED + red strip enhanced stomatal amount, stomatal density, transpiration rate, photosynthesis rate, CO2 intracellular, and stomatal conductance, meanwhile leaf thickness in 4 white LED + blue strip. Blue LED increases total amount of secondary metabolites in Water Rose Apple Madu deli leaves and mostly identified as phenylpropanoids group. In conclusion, the role of dominance red light LED can enhance growth and physiological aspects of water rose apple seedling.
Keyword: fruit crop, environment, LED, secondary metabolite, photosynthesis

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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