Judul: Nutrients Intake and Lifestyle With Adolescent Nutritional Status During The Covid-19 Pandemic
Abstrak: Masa pandemi Covid-19 menimbulkan pembatasan aktivitas di luar rumah termasuk belajar secara daring yang mempengaruhi asupan zat gizi dan gaya hidup (screen time, durasi tidur, aktivitas fisik) terutama kelompok usia remaja. penelitian ini bertujuan menganalisis hubungan antara asupan zat gizi dan gaya hidup (screen time, durasi tidur, aktivitas fisik) dengan status gizi remaja. Desain penelitian cross sectional study dengan subjek sebanyak 99 orang yang dilakukan pada Desember 2020 hingga Januari 2021 di MTsN 5 Kuningan. Subjek dipilih secara purposive dengan pengumpulan data primer melalui kuesioner dan wawancara. Subjek berusia 13-15 tahun dengan sebagian besar (83,84%) memiliki status gizi baik. Selama pandemi Covid-19 subjek mengalami penurunan durasi tidur (44,4%) dan kebiasaan olahraga (53,6%), serta peningkatan screen time (57,6%) dan konsumsi camilan (44,4%). Durasi tidur tidak memiliki hubungan signifikan dengan screen time, aktivitas fisik, dan asupan zat gizi. Screen time juga tidak memiliki hubungan dengan aktivitas fisik dan asupan zat gizi. Sementara itu, status gizi memiliki hubungan negatif signifikan dengan kecukupan energi, protein, dan karbohidrat, namun kecukupan lemak dengan status gizi tidak memiliki hubungan signifikan. Status gizi subjek juga tidak memiliki hubungan dengan screen time, durasi tidur, dan aktivitas fisik., The Covid-19 pandemic period has caused restrictions on activities outside the home, including online learning which affects nutrient intake and lifestyle (screen time, sleep duration, physical activity), especially adolescent age group. This research aimed to analyze the correlation between nutrient intake and lifestyle (screen time, sleep duration, physical activity) with adolescent nutritional status. The research design used cross sectional study with total of 99 subjects, which was conducted from December 2020 to January 2021 at MTsN 5 Kuningan. Subjects were selected purposively by collecting primary data through questionnaires and interviews. Subjects aged 13-15 years with most (83,84%) had good nutritional status. During the Covid-19 pandemic, subjects experienced a decrease in sleep duration (44,4%) and exercise habits (53,6%), as well as an increase in screen time (57,6%) and snack consumption (44,4%). Sleep duration didn’t have a significant correlation with screen time, physical activity, and nutrient intake. Screen time also has no correlation with physical activity and nutrient intake. Meanwhile, nutritional status had a significant negative correlation with energy, protein, and carbohydrate adequacy, but fat adequacy with nutritional status didn’t have a significant correlation. The nutritional status of the subjects also had no correlation with screen time, sleep duration, and physical activity.
Keyword: nutrients adequacy level, nutritional status, physical activity, screen  time, sleep duration

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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