Judul: Analysis of Breakfast Habits and Breakfast Nutrients Contribution of Elementary School Students in Cijeruk, Bogor District
Abstrak: Sarapan merupakan waktu makan yang penting bagi siswa. Saat ini masih banyak masalah sarapan pada anak usia sekolah yaitu kebiasaan sarapan yang kurang baik serta kualitas yang rendah. Penelitian ini bertujuan menganalisis kebiasaan dan kontribusi gizi sarapan pada siswa sekolah dasar di Cijeruk, Kabupaten Bogor. Desain penelitian ini adalah cross sectional study menggunakan data sekunder penelitian Hardinsyah et al. (2019) di 16 sekolah dasar dengan subjek penelitian sebanyak 915 siswa. Data yang dikumpulkan meliputi karakteristik subjek serta konsumsi makanan dan minuman, termasuk sarapan melalui metode food recall 3x24 jam. Asupan energi dan 11 zat gizi diolah menggunakan daftar kandungan gizi pangan dan kebutuhan zat gizi dihitung untuk setiap siswa. Kebiasaan sarapan meliputi frekuensi sarapan selama seminggu terakhir, jenis makanan minuman dan tipe sarapan. Hasil penelitian menunjukkan sebagian besar subjek rutin sarapan selama seminggu terakhir dengan jenis sarapan berupa pangan protein dan minuman manis. Pada umumnya tipe sarapan adalah pangan karbohidrat, pangan protein dan minuman. Kontribusi sarapan berkisar dari 5,6±4,8% (vitamin B9) sampai 27,9±17,3% (zat besi). Terdapat perbedaan signifikan pada kontribusi protein dan air antara subjek laki-laki dan perempuan. Tidak terdapat perbedaan signifikan kontribusi gizi makro dan mikro berdasarkan kondisi sosek keluarga subjek., Breakfast is an important meal time for school children. Neverthless, there are still many problems of breakfast in children including low quality and poor breakfast habit. The objective of this study was to analyze breakfast habits and its contribution in elementary school children in Cijeruk, Bogor. The design of this study was a cross sectional study using secondary data from Hardinsyah et al. (2019) at 16 elementary schools with 915 subjects. Data was collected such as subject characteristic, food and beverage consumption included breakfast by food recall 3x24 hours. Energy and 11 nutrients intake were processed using food nutrients composition and nutriens requirements were calculated for each students. Breakfast habits such as breakfast frequency, type of food and beverage, and type of breakfast. The results showed that most of the subjects was always had breakfast frequently for the past week with type of food that consumed during breakfast was protein food and sweet drink. In general, type of breakfast consumption was carbohydrate, protein food, and beverage. Breakfast contribution about 5,6±4,8% (vitamin B9) until 27,9±17,3% (iron). There was significant differences (p<0.05) between the contribution of protein and water from breakfast in male and female students. There was no significant differences (p>0.05) for the contribution of macro and micronutrients between socioeconomic subject.
Keyword: breakfast, nutrients contribution, school students

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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