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: Factors related to Stress Levels and Quality of Food Consumption of Overweight and Normal Hight school Adolecents during the Pandemic Period
Abstrak: Masa pandemi Covid-19 menimbulkan pembatasan aktivitas di luar rumah termasuk belajar secara daring yang memengaruhi stres akademik, konsumsi pangan dan gaya hidup (kebiasaan makan, kegiatan daring, aktivitas fisik). Penelitian ini bertujuan menganalisis faktor-faktor yang berhubungan dengan tingkat stres dan kualitas konsumsi pangan remaja SMA dengan status gizi overweight dan normal pada masa pandemi. Desain penelitian ini adalah comparative cross sectional study dengan subjek sebanyak 41 remaja dengan status gizi normal dan 41 remaja overweight. Subjek dipilih secara purposive dengan pengumpulan data primer melalui kuesioner dan wawancara. Berdasarkan hasil uji beda Mann-Whitney dan Independent Sample T-Test terdapat perbedaan yang signifikan (p<0,05) pada variabel waktu kegiatan daring (p=0,041), tingkat kecukupan energi (p=0,040), frekuensi konsumsi makanan pokok (p=0,004), protein nabati (p=0,021), dan minuman (p=0,003) antara subjek normal dan overweight. Hasil uji korelasi Spearman menunjukkan terdapat hubungan yang signifikan positif (p<0,05) antara tingkat kecukupan energi, protein, lemak, karbohidrat, dan vitamin C dengan kualitas konsumsi pangan. Variabel jenis kelamin berhubungan signifikan (p<0,05) dengan tingkat stres. Berdasarkan uji korelasi Spearman, tidak terdapat hubungan yang signifikan (p>0,05) antara tingkat stres dan kualitas konsumsi pangan dengan status gizi., The Covid-19 pandemic has caused restrictions on activities outside the home including online learning which affects academic stress, food consumption and lifestyle (eating habits, online activities, physical activity). This study aims to analyze factors related to stress levels and quality of food consumption Hight school Adolecent with overweight and normal nutritional status during the pandemic Period. The design of this study was comparative cross sectional study of 41 adolescents with normal nutritional status and 41 overweight adolescents selected by purposive sampling. Data was collected through questionnaires and interviews. Based on the results of the Mann-Whitney difference test and Independent Sample T-test, there were significant differences (p<0.05) in the online activity time variable (p=0.041), energy adequacy level (p=0.040), frequency of consumption of staple food (p=0.004), protein vegetable (p=0.021), and drinks (p=0.003) between normal and overweight subjects. The results of the Spearman correlation test showed that there was a significant positive relationship (p<0.05) between the level of adequacy of energy, protein, fat, carbohydrates, and vitamin C with the quality of food consumption. Gender variable has a significant relationship (p<0.05) with stress levels. Based on the Spearman correlation test, there is no significant relationship (p>0.05) between stress levels and the quality of food consumption with nutritional status.
Keyword: adolescents, level of nutritional adequacy, nutritional status, quality of food consumption, 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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