Judul: Comparation of Satiety Index between Purple Sweet Potato and Red Bean Flakes with Commercial Cereals in Normal and Obese Adults
Abstrak: Obesitas terjadi akibat penumpukan lemak berlebih dalam tubuh, yang dapat dipengaruhi oleh pola makan. Salah satu cara untuk mencegah obesitas adalah mengonsumsi makanan dengan indeks kenyang yang tinggi. Penelitian ini bertujuan untuk membandingkan indeks kenyang antara flakes ubi dengan sereal komersial, serta mengevaluasi profil indeks kenyang antara subjek normal dan obesitas. Penelitian melibatkan 16 subjek dengan status gizi normal dan 16 subjek obesitas, menggunakan metode semi-crossover study. Data yang dikumpulkan meliputi skor kenyang dan indeks kenyang. Skor kenyang dihitung dengan mengukur area di bawah kurva (AUC), sedangkan indeks kenyang dihitung dengan membandingkan AUC makanan uji dengan roti putih dan mengalikannya dengan 100%. Makanan uji dalam penelitian ini adalah roti putih, flakes ubi ungu, flakes ubi ungu dengan kacang merah, dan sereal komersial. Hasil penelitian menunjukkan perbedaan waktu yang dibutuhkan untuk perubahan rasa kenyang menjadi lapar pada subjek obesitas, yaitu roti putih pada 120 menit, sereal komersial pada 115 menit, flakes ubi ungu dengan kacang merah pada 176 menit, dan serpihan ubi ungu pada 180 menit. Penelitian ini mengungkapkan tidak ada perbedaan signifikan pada indeks kenyang antara flakes ubi ungu dan sereal komersial, mendukung bahwa orang obesitas dapat memiliki indeks kenyang yang serupa dengan orang normal dengan mengonsumsi flakes dengan susu., Obesity occurs due to the accumulation of excess fat in the body, which can be influenced by diet. One way to prevent obesity is by consuming foods with a high satiety index. This study aimed to compare satiety index between developed tuber flakes with commercial one. This study also evaluated the profile of satiety index between normal and obesity subjects. The study involved 16 subjects with normal nutritional status and 16 obese subjects, using a semi-crossover study method. Data collected included satiety scores and the satiety index. Satiety scores were calculated by measuring the area under the curve (AUC) using the trapezoid method, while the satiety index was calculated by comparing the AUC of test foods with that of white bread and multiplying by 100%. The test foods in this study were white bread, purple sweet potato flakes, purple sweet potato flakes with red beans, and commercial cereal. The results showed differences in the time it took for the feeling of fullness to change to hunger in obese subjects, white bread at 120 min, commercial cereal at 115 min, purple sweet potato flakes with red beans at 176 min, and purple sweet potato flakes at 180 min. Currents study reveals that there was no significant satiety index between tuber flakes and commercial one. This founding support the obese people to have a similar satiety index as normal people by consuming flakes with milk.
Keyword: obesity, satiety index, satiety score

Judul: Comparison of the Satiety Index of White Bread, White Rice, and Ready-to-Eat Cereal in Normal and Obese Adults
Abstrak: Obesitas merupakan masalah gizi yang diakibatkan oleh overcaloric nutrition intake yang berpengaruh pada tingginya komposisi lemak dalam tubuh. Penelitian ini bertujuan membandingkan indeks kekenyangan orang normal dengan orang yang mengalami obesitas serta mengkaji hubungan indeks massa tubuh dengan indeks kekenyangan. Penelitian ini melibatkan responden sebanyak 16 subjek normal dan 16 subjek obesitas dengan metode semi crossover design study. Indeks kekenyangan yang dimaksud terdiri dari skor satiety dan satiety index. Skor satiety diperoleh dengan menghitung luas area di bawah kurva VAS dengan menggunakan metode trapezoid. Satiety index dihitung dengan membandingkan skor satiety pada indeks kenyang pangan uji dengan roti tawar dikalikan 100. Pangan uji yang digunakan dalam penelitian ini adalah roti tawar, nasi putih, dan sereal komersial. Terdapat perbedaan antara subjek normal dan obesitas pada pangan uji roti tawar (skor satiety indeks lapar [p=0,002] dan kuantitas makan [p=0,030]) dan nasi putih (skor satiety index rasa lapar [p=0,008], rasa kenyang [p=0,016], keinginan makan [p=<0,001], kuantitas makan [p=0,023], dan satiety index [p=0,020]). Perbedaan tidak ditemukan pada indikator satiety lainnya. Hasil penelitian ini juga menunjukkan bahwa terdapat hubungan antara indeks massa tubuh dengan skor satiety indeks rasa lapar (p=0,015) dan kuantitas makan (p=0,015). Perbedaan tidak ditemukan untuk percent body fat dan indikator satiety lainnya., Obesity is a nutritional problem caused by overcaloric nutrition intake which affects the high composition of fat in the body. This study aims to compare the satiety index of normal people with obese people and examine the relationship between body mass index and satiety index. This research involved 16 normal and 16 obese subjects using semi-crossover design study method. The data discussed consists of satiety score and satiety index. Satiety score is obtained by calculating the area under the VAS curve using trapezoid method. Satiety index is calculated by comparing the satiety score on the satiety index of test food with white bread multiplied by 100. The test foods used in this study were white bread, white rice, and ready-to-eat cereal. There were differences between normal and obese subjects in the white bread (hunger index score [p=0.002] and prospective consumption [p=0.030]) and white rice (hunger satiety index score [p=0.008], satiety [p =0.016], desire to eat [p=<0.001], quantity of eating [p=0.023], and satiety index [p=0.020]). This study's results also showed a relationship between body mass index and satiety scores, hunger index (p=0.015), and quantity of food (p=0.015). Differences were not found for percent body fat and other satiety indicators.
Keyword: obesity, satiety index, satiety score, staple food

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.
Keyword: