Judul: Vegetable and Fruit Consumption Patterns During Covid-19 Pandemic in Adolencent in Pariaman City
Abstrak: Konsumsi sayur dan buah remaja masih tergolong kurang. Konsumsi sayur dan buah merupakan salah satu langkah pencegahan Covid-19 untuk meningkatkan imunitas tubuh. Penelitian ini bertujuan menganalisis hubungan jenis kelamin, pengetahuan dan sikap gizi, ketersediaan, dan preferensi konsumsi sayur dan buah serta tingkat kecemasan dengan konsumsi sayur dan buah remaja di masa pandemi Covid-19. Desain penelitian ini adalah cross-sectional study dengan 95 orang contoh yang dilakukan pada bulan Desember 2020－Januari 2021 di SMPN 2 Pariaman. Contoh dipilih secara purposive dengan pengumpulan data primer melalui kuesioner dan wawancara. Konsumsi sayur contoh dalam penelitian ini tergolong kurang (77,9%) dan konsumsi buah tergolong cukup (89,5%). Konsumsi sayur dan buah contoh dalam penelitian ini berhubungan secara signifikan dengan arah positif dengan sikap gizi contoh (P value=0,011). Sementara itu, pengetahuan gizi, tingkat kecemasan contoh selama pandemi Covid-19 tidak memiliki hubungan yang signifikan dengan konsumsi sayur dan buah. Ketersediaan sayur dan buah di rumah tidak berhubungan dengan preferensi konsumsi sayur dan buah dan preferensi contoh juga tidak berhubungan dengan konsumsi sayur dan buah contoh., Consumption of vegetables and fruit in adolescents is still relatively low. The Covid-19 pandemic has affected the habit of consuming vegetables and fruit. Consumption of vegetables and fruit is one of the steps to prevent Covid-19 to increase body immunity. This study aims to analyze the relationship between, nutritional knowledge and attitudes, availability, and preferences for consumption of vegetables and fruit as well as anxiety levels with the consumption of vegetables and fruit in adolescents during the Covid-19 pandemic. The design of this research is a cross-sectional study with 95 samples which was conducted in December 2020 －January 2021 at SMPN 2 Pariaman. Samples were selected purposively and used primary data through questionnaires and interviews. Consumption of vegetable samples in this study is classified as less (77,9%) and fruit consumption is quite adequate (89,5%). The consumption of vegetables and fruit samples in this study was significantly related to nutritional attitudes (P value = 0,011). Meanwhile, knowledge of nutrition, level of anxiety during the Covid-19 pandemic which did not have a significant relationship with consumption of vegetables and fruit. The availability of vegetables and fruit at home is not related to the consumption preferences of vegetables and fruit and sample preferences are also not related to the consumption of vegetables and fruit samples.
Keyword: Adolencent, factor that affect, vegetable and fruit consumption

Judul: Preference and Availability of Vegetable, Fruit, and Supplement Consumption at Adolescents in Jakarta During Covid-19 Pandemic
Abstrak: Konsumsi sayur dan buah yang cukup merupakan salah satu hal penting untuk memperkuat sistem daya tahan tubuh manusia terutama pada masa pandemi covid-19. Kebutuhan vitamin, mineral, dan serat dapat diperoleh dari makanan dan suplemen, karena tubuh tidak dapat memproduksinya secara cukup. Penelitian ini dilakukan dengan tujuan menganalisis preferensi dan ketersediaan terhadap konsumsi sayur, buah, dan suplemen pada remaja di Jakarta saat masa pandemi covid-19. Desain penelitian yang digunakan yaitu cross-sectional study. Pengumpulan data dilakukan dengan pengisian kuesioner dan FFQ secara daring self-administered. Pengambilan data dilakukan pada bulan Oktober 2020 dengan subjek sebanyak 64 orang. Hasil penelitian menunjukkan bahwa sebagian besar subjek memiliki preferensi yang baik terhadap konsumsi sayur, buah, dan suplemen (90,6%). Sebagian besar subjek memiliki ketersediaan yang baik terhadap sayur, buah, dan suplemen (95,3%). Laki-laki mengonsumsi sayur dan buah lebih baik (r=-0,219, p=0,080), selain itu semakin tua responden semakin kurang konsumsi sayur dan buahnya (r=-0,214, p=0,089). Semakin tinggi tingkat pendidikan subjek, semakin kurang konsumsi sayur dan buah (r=-0,298, p=0,017). Semakin baik preferensi seseorang, semakin sering mengonsumsi suplemen (r=0,902, p=0,016) dan semakin baik ketersediaan, semakin sering mengonsumsi suplemen (r=0,221, p=0,079), Sufficient consumption of vegetables and fruit is one of the important things to strengthen immune system mainly during covid-19 pandemic. Vitamin, mineral, and fiber requirements are attainable from food and supplement, because the body cannot produce them sufficiently. This research aimed to analyze the preference and availability of vegetable, fruit, and supplement consumption at adolescents in Jakarta during the covid-19 quarantine. The design of this research was a cross-sectional study. Data collection consisted of filling out online self-administered questionnaire and FFQ. The data was collected in October 2020 with 64 subject. The research represent that subjects mostly had a good preference for vegetable, fruit and supplement consumption (90,6%). Most of the subjects had a good availability of vegetable, fruit, and supplement (95,3%). Male were more often consumption of vegetable and fruit (r=-0,219, p=0,080), meanwhile the older subjects represent the less consumption of vegetable and fruit (r=-0,214, p=0,089). The higher level of education of the subject means less consumption of vegetable and fruit (r=-0,298, p=0,017). More better person's preference means more frequent the supplement (r=0,902, p=0,016) and more better availability of the subjects represent more frequent consume supplements (r=0,221, p=0,079).
Keyword: adolescent, availability, preference, supplement consumption, vegetable-fruit consumption

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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