Judul: Nutritional Knowledge, Eating Habits and Lifestyle  Change, with Nutritional Status of IPB University Student During Covid-19  Pandemic
Abstrak: Pandemi Covid-19 mengakibatkan perubahan kebiasaan makan dan gaya hidup. Perubahan terjadi karena pembelajaran daring dari rumah dan meningkatnya kesadaran hidup lebih sehat. Ilmu kesehatan erat kaitannya dengan kurikulum gizi, sehingga mahasiswa gizi diharapkan dapat menerapkan ilmu tersebut di kehidupan sehari-hari. Tujuan penelitian yaitu menganalisis hubungan pengetahuan gizi, perubahan kebiasaan makan dan gaya hidup, dengan status gizi mahasiswa IPB saat pandemi Covid-19. Desain penelitian cross sectional study yang dilaksanakan pada bulan April sampai Juli 2021. Data primer diperoleh dari pengisian kuesioner, wawancara, dan self report data antropometri. Hasil penelitian menunjukkan sebagian besar subjek berstatus gizi normal (54,7%). Tingkat pengetahuan gizi subjek tergolong baik dan cukup dengan rata-rata skor 82,5. Persentase perubahan kebiasaan makan terbesar terjadi pada peningkatan konsumsi buah dan sayur (66,7%). Persentase perubahan gaya hidup terbesar terjadi pada kebiasaan pemakaian masker setiap beraktivitas diluar rumah (94,7%). Hasil uji korelasi Spearman menunjukkan tidak terdapat hubungan yang signifikan (p value>0,05) antara skor pengetahuan gizi, skor perubahan kebiasaan makan, dan skor perubahan gaya hidup dengan Indeks Massa Tubuh (IMT)., Covid-19 pandemic impact to eating habits and lifestyle changes. Its occured due to online learning from home and the increasing of health awareness. Health science closely related to the nutrition curriculum, therefore nutrition student are expected to imply their knowledge in daily life. The aim of this research is to analyze the relation of nutritional knowledge, changes in eating habits and lifestyle to nutritional status of IPB University students during the pandemic. This research design was a cross sectional study that carried out from April until July 2021. Primary data obtained by filling out questionnaires, interview, and self reporting anthropometric data. The results of this research showed that most of the subject had normal nutritional status (54,7%). The level of subject nutritional knowledge is good and adequate with average score 82,5. The largest percentage of changes in eating habits is the increase of fruit and vegetable consumption (66,7%). The largest percentage of changes in lifestyle is the increase of wearing masks habit everytime the subject go outside (94,7%). The results of Spearman correlation test showed that was no significant relationship (p value>0,05) between score of nutritional knowledge, eating habit, and lifestyle changes with the Body Mass Index (BMI).
Keyword: Covid-19 pandemic, eating habits change, lifestyle change, nutritional knowledge level, nutritional status

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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