Judul: Pengetahuan Gizi dan Kesehatan, Keragaman Pangan serta Aktivitas Fisik Mahasiswa Gizi IPB selama Masa Pandemi Covid-19
Abstrak: Pencegahan terhadap Covid-19 merupakan hal yang penting dilakukan oleh semua orang, termasuk mahasiswa. Penerapan protokol kesehatan, mengonsumsi makanan beragam dan meningkatkan aktivitas fisik merupakan sebagian upaya yang dapat dilakukan untuk mencegah penularan Covid-19. Tujuan dari penelitian ini ialah menganalisis hubungan antara pengetahuan gizi dan kesehatan dengan keragaman pangan dan aktivitas fisik mahasiswa Gizi IPB. Desain penelitian adalah cross sectional dan melibatkan 65 subyek. Pengumpulan data dilakukan menggunakan google form dan wawancara melalui telepon. Hasil penelitian menunjukkan bahwa sebagian besar subyek (56,9%) memiliki pengetahuan gizi dan kesehatan yang tergolong sedang, hampir separuh subyek (49,2%) memiliki keragaman pangan yang baik dengan rata-rata konsumsi 5,57 ± 1,21 jenis pangan dan sebagian besar subyek (69,2%) memiliki aktivitas fisik ringan dengan rata-rata PAL sebesar 1,49 ± 0,128. Tidak terdapat hubungan yang signifikan (p>0,05) antara pengetahuan gizi dan kesehatan dengan keragaman pangan dan aktivitas fisik. Namun demikian, subyek dengan pengetahuan gizi dan kesehatan yang baik memiliki rata-rata skor keragaman pangan dan skor aktivitas fisik yang lebih tinggi dibandingkan subyek dengan pengetahuan kurang., Prevention of Covid-19 is an important thing to do by everyone, including student. Implementation of health protocols, eating a variety of foods and increasing physical activity are among of the efforts to prevent and/or control Covid-19 transmission. The purpose of this study was to analyze the relationship between nutrition and health knowledge with dietary diversity and physical activity among student at IPB University. This cross sectional study involved 65 subjects. Data collection carried out using google forms and telephone interviews. The results showed that most of the subjects (56.9%) had moderate category of knowledge of nutrition and health, about half of subjects (49.2%) had a good category of food diversity with an average consumption was 5.57 ± 1.21 types of food. and most of the subjects (69.2%) had light category of physical activity with an average PAL was 1.49 ± 0.128. There was no significant relationship (p>0.05) between knowledge of nutrition and health with food diversity and physical activity. However, subjects with a good category of nutrition and health knowledge had a slightly higher average of dietary diversity score and physical activity score than subjects with lower category of nutrition and health knowledge.
Keyword: dietary diversity, nutrition and health knowledge, physical activity

Judul: Correlation between Nutrition Knowledge, Physical Activity, and Eating Habits among College Students during COVID-19 Pandemic
Abstrak: Kondisi pandemi Covid-19 memengaruhi kebiasaan makan dan aktivitas fisik yang dapat beresiko obesitas, sehingga diperlukan pengetahuan gizi dan gaya hidup yang sehat. Penelitian ini bertujuan menganalisis hubungan pengetahuan gizi, aktivitas fisik dan kebiasaan makan mahasiswa selama pandemi Covid-19. Desain penelitian ini adalah cross sectional melibatkan 83 mahasiswa yang berdomisili di Jabodetabek. Data pengetahuan gizi dan aktivitas fisik dikumpulkan dengan self-administered menggunakan google form, sedangkan data kebiasaan makan melalui wawancara online. Hasil penelitian menunjukkan pengetahuan gizi 83,1% subjek tergolong baik. Tingkat aktivitas fisik hampir separuh subjek (43,4%) tergolong berat dan rata-rata waktu duduk subjek 6,8 jam/hari. Kebiasaan makan mahasiswa belum sesuai anjuran pedoman gizi seimbang. Tingkat kecukupan energi dan karbohidrat subjek tergolong defisit berat, tetapi tingkat kecukupan protein dan lemak tergolong normal. Hampir 2/3 subjek memiliki tingkat kecukupan zat gizi mikro tergolong kurang. Terdapat hubungan positif (<0,05) antara pendidikan ibu dengan tingkat kecukupan lemak dan vitamin E, serta konsumsi daging sapi, kangkung, selada, mangga, dan sosis. Pendapatan orang tua berhubungan positif dengan konsumsi roti gandum, kurma, dan tahu (p<0,05). Tidak terdapat hubungan (p>0,05) antara pengetahuan gizi dengan tingkat kecukupan gizi, namun berhubungan positif dengan konsumsi ubi, buncis, salak, dan sosis (p<0,05). Tidak terdapat hubungan antara aktivitas fisik dengan kebiasaan makan (p>0,05), The Covid-19 pandemic affects eating habits and physical activity that can risk obesity; therefore, knowledge of nutrition and a healthy lifestyle are needed. This study analyzes the correlation between nutrition knowledge, physical activity, and eating habits among college students during the Covid-19 pandemic. This study used a cross-sectional design involving 83 students in Jabodetabek. The data were collected via google form and through online interviews. The results showed 83,1% of subjects had good nutrition knowledge. The physical activity level of 43,4% of subjects was classified as high, and the average sitting time was 6,8 hours/day. Students' eating habits are not yet meet the nutrition guidelines. Energy and carbohydrate adequacy were severe deficits, but the protein and fat were normal. Almost 2/3 of the subjects had low micronutrient adequacy. There was a positive correlation (<0,05) between maternal education and fat and vitamin E adequacy and intake of several foods. Parental income was positively related to intake of frequence of some food (p<0,05). There was no correlation (p>0,05) between nutrition knowledge and nutrient adequacy, between physical activity and eating habits (p>0,05), but it was positively related to intake of several foods (p<0,05).
Keyword: College student, Covid-19 pandemic, Eating habits, Nutrition knowledge, Physical activity, Aktivitas fisik, Kebiasaan makan, Mahasiswa, Pengetahuan gizi

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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