Judul: Analysis of Covid-19 Knowledge, Intake, Eating Behavior,  Stress Level, and Quality of Life in Students during Pandemic
Abstrak: Penelitian ini bertujuan menganalisis hubungan tingkat pengetahuan terkait Covid-19, asupan makanan, perilaku makan, tingkat stres, dan kualitas hidup mahasiswa saat pandemi. Desain penelitian ini adalah studi cross sectional dengan jumlah subjek sebanyak 81 mahasiswa Gizi Masyarakat, Institut Pertanian Bogor yang dipilih secara purposif. Penelitian dilakukan pada bulan Juli 2022–September 2022. Pengumpulan data melalui wawancara dan kuesioner online. Tingkat pengetahuan terkait Covid-19 pada subjek tergolong dalam kategori sedang (60%). Rata-rata skor perilaku makan pada subjek paling banyak yaitu perilaku makan external eating. Sebagian besar (46%) subjek mengalami stres sedang. Hasil analisis menunjukkan bahwa terdapat hubungan yang signifikan antara tingkat stres dengan emotional eating, domain hubungan sosial dan domain lingkungan pada kualitas hidup (p<0,05). Selain itu, terdapat hubungan yang signifikan juga antara variabel uang saku dengan tingkat stres (p<0,05). Tidak ada hubungan yang signifikan antara pengetahuan Covid-19 dengan tingkat stres (p>0,05). Hal ini juga terjadi hubungan yang tidak signifikan antara variabel jenis kelamin, usia, tempat tinggal, ketersediaan internet, dan angkatan dengan tingkat stres (p>0,05). Begitupula dengan variabel tingkat stres dengan tingkat kecukupan zat gizi makro dan mikro, perilaku makan external eating dan restrained eating, serta domain fisik dan psikologis pada kualitas hidup (p>0,05) yang juga menunjukkan tidak adanya hubungan yang signifikan., The aims of this study is to analyze the correlation between Covid-19 knowledge, food intake, eating behavior, stress level, and quality of life during pandemic. The design of this research is cross sectional study with 81 subjects of community nutrition, IPB University students selected by purposive sampling. This research was conducted in July 2022–September 2022. Data was collected through interview and online questionnaire. The level of Covid-19 knowledge of the subjects is in the medium category. The average score of eating behavior in the most subjects is external eating. Most of the subjects (46%) experienced moderate stress. The result showed that there was significant correlation between stress level with emotional eating, social relationship and environmental health in quality of life (p<0.05). There was a significant correlation between allowance with stress levels (p<0.05). There was no significant correlation between Covid-19 knowledge with stress level (p>0.05). Also, there was no significant correlation between gender, age, residence, internet network, and years of college with stress level (p>0.05). The same for variables of stress levels with the level of adequacy of macro and micro nutrients, external eating and restrained eating, physical and psychological in quality of life (p>0.05) also showed no significant correlation.
Keyword: Covid-19 knowledge, Eating behavior, Nutrient adequacy level, Stress  level, Quality of life

Judul: Correlation between Stress Level, Emotional Eating, Snacking Habit, and Nutrients Intake among College Students during Covid-19 Pandemic
Abstrak: Penelitian ini bertujuan menganalisis hubungan tingkat stres dengan emotional eating, kebiasaan snacking, serta asupan zat gizi mahasiswa selama pandemi Covid-19. Penelitian ini merupakan cross sectional study melibatkan 98 mahasiswa yang berdomisili di Jabodetabek. Pengambilan data dilakukan secara daring pada Januari–Februari 2021 melalui kuesioner daring dan wawancara daring. Penentuan tingkat stres menggunakan kuesioner Perceived Stres Scale 10, sedangkan emotional eating dengan Dutch Eating Behavior Questionnaire-Emotional. Uji normalitas menggunakan uji Kolmogorov-Smirnov serta analisis hubungan antara tingkat stres dengan emotional eating menggunakan uji korelasi Spearman dan hubungan antara tingkat stres dengan kebiasaan snacking dan asupan zat gizi menggunakan uji korelasi Pearson. Hampir ¾ subjek (70,4%) mengalami stres sedang, sekitar separuh (52,0%) berperilaku emotional eater, dan hampir 2/3 (60,4%) mengonsumsi camilan >3 kali/hari. Sebanyak 2/5 subjek (39,7%) memiliki kecukupan protein defisit dan 36,7% berlebih untuk lemak. Mayoritas subjek memiliki tingkat kecukupan energi (49,0%) dan karbohidrat (70,4%) yang tergolong defisit. Tidak terdapat hubungan signifikan (p>0,05) antara tingkat stres dengan kebiasaan snacking dan asupan zat gizi, namun penelitian ini menemukan hubungan positif (p=0,04; r=0,21) antara tingkat stres dengan emotional eating, artinya semakin berat tingkat stres maka subjek semakin berperilaku emotional eating., This study aims to analyze the correlation of stress level, emotional eating, snacking habit, and nutrients intake among college students during Covid-19 pandemic. This study was a cross-sectional study, involves 98 college students in Jabodetabek. Data collection was carried out in January–February 2021 through an online questionnaire and interviews. Determining the stress level by Perceived Stress Scale 10, while emotional eating by Dutch Eating Behavior Questionnaire-Emotional. The normality test used the Kolmogorov-Smirnov, analysis of the correlation between stress level and emotional eating using Spearman while snacking habit and nutrient intake using Pearson. Almost ¾ of the subjects (70,4%) experienced moderate stress, about half (52,0%) were emotional eater, and almost 2/3 (60,4%) consumed snacks >3 times/day. A total of 2/5 subjects (39,7%) had a protein adequate level was classified as deficit and 36,7% excess for fat. The majority of the subjects had adequate levels of energy (49,0%) and carbohydrates (70,4%) which were classified as severe deficits. There was no significant correlation (p>0,05) between perceived stress with snacking habits and nutrients intake, but this study found a positive correlation (p=0,04; r=0,21) between stress level and emotional eating, that means the higher the stress level, the subjects more emotional eating.
Keyword: College students, Emotional eating, Nutrients intake, Snacking habit, Stress level

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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