Judul: Karakteristik Pangan Jajanan Anak Sekolah Dasar di Indonesia
Abstrak: The healthy level of food in elementary school could be the one of main obstacle for Indonesia to develop human resources in the future. Observation in periodic time must be done to minimalize the negative affect. National Agency of Drugs and Foods Control has already made a survey to collect detail of elementary school children food which sold in the school. The purpose of this research are (1) To explained the characteristics of elementary school children food in Indonesia; (2) To identify the food which not eligible to consume by elementary school children. This survey had been done in February till Mei 2012. Based on 7207 samples, fried food was the most and then followed by snacks, ice, noodles, meatballs, softdrink, and jelly. From these sample, testing of parameters was carried out to determine whether certain elementary school children food eligible to consume or not. Test results showed that there was food not eligible to consume by elementary school children because of excessive food additives and microorganism contamination. The main caused of elementary school children food becomed ineligible for ice, jelly, and softdrink was cyclamate. Meatballs and fried food were indicated contaminating by high bacterial based on total plate count testing parameter. Noodles were known containing any preservatives such as formaldehyde and snacks contained borax. Biplot analysis showed that Papua Maluku region have the highest number of ineligible elementary school children food and risk substance for ice, jelly, fried food, snacks, and noodles.
Keyword: elementary school children food, biplot analysis

Judul: Snacking Habits and Nutrients Contribution on Their Nutrient Requirement of Elementary School Students in Cijeruk, Bogor
Abstrak: Diperkirakan makanan jajanan semakin banyak dikonsumsi oleh masyarakat termasuk siswa usia sekolah. Penelitian ini bertujuan menganalisis kebiasaan mengonsumsi makan dan minum jajanan dan menganalisis kontribusi jajanan zat gizi makro dan mikro terhadap kebutuhan harian anak sekolah. Desain penelitian ini adalah cross sectional study dengan menggunakan data sekunder pada 915 subjek yang merupakan siswa dari 16 sekolah dasar di Kecamatan Cijeruk, Kabupaten Bogor yang dilakukan pada awal tahun 2020. Data yang dikumpulkan meliputi karakteristik subjek, konsumsi makanan dan minuman termasuk jajanan menggunakan metode food recall 3x24. Asupan energi dan 11 zat gizi diolah menggunakan daftar kandungan gizi pangan, dan kebutuhan zat gizi dihitung untuk setiap siswa. Kebiasaan makanan jajanan meliputi frekuensi, jenis, waktu makan dan tipe makanan jajanan. Hasil penelitian menunjukkan kebiasaan mengonsumsi makanan jajanan sebagian besar sebanyak 2 kali/hari yaitu pagi dan siang dengan jenis jajanan berupa gorengan dan minuman manis. Pada umumnya tipe makanan jajanan adalah pangan karbohidrat dengan minuman. Kontribusi makanan jajanan berkisar dari 5,26±5,82% (kalsium) sampai 23,6±11,4% (air). Hasil uji statistik menunjukkan terdapat hubungan yang signifikan antara kontribusi gizi dari jajanan dengan status gizi dan tidak ada perbedaan antar status sosial ekonomi., It is estimated that the community, including school-age students, increasingly consume snack foods. This study aimed to analyze snacking habits and to analyze macronutrients and micronutrient snacking contribution on their daily nutrient requirement of school students. This cross-sectional study utilizes secondary sources that involved 915 subjects, in this case, students from 16 elementary schools in Cijeruk, Bogor District that commenced in early year 2020. Data collected such as subject characteristic, food and beverage consumption included snacks by recall 3x24 hours. Energy intake and 11 nutrients were processed using a list of nutritional food contents, and nutrient requirements were calculated for each student. Snack food habits include frequency, type, mealtime and type of snack food. The results showed that the habit of consuming snack foods mainly was two times/day, namely in the morning and afternoon with the types of snacks in fried foods and sweet drinks. In general, the type of snack food is carbohydrate food with drinks. The contribution of snacks ranged from 5.26±5.82% (calcium) to 23.6±11.4% (water). The statistical tests showed a significant relationship between the nutritional contribution of snacks and nutritional status, and there was no difference between socioeconomic status.
Keyword: Contribution snack, School students, Snacking habits

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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