Judul: Pengetahuan, Sikap, dan Perilaku Mencegah Terinfeksi Covid-19 pada Generasi Y di Kabupaten Ponorogo, Jawa Timur
Abstrak: Generasi Y memiliki jumlah proporsi tertinggi dalam kasus terinfeksi Covid-19. Hal ini disebabkan oleh tingginya mobilitas dan aktivitas di luar rumah. Penelitian ini bertujuan untuk menganalisis pengaruh karakteristik individu, pengetahuan, dan sikap terhadap perilaku mencegah terinfeksi Covid-19 di Ponorogo. Sampel dalam penelitian berjumlah 100 orang dengan rentang usia 2035 tahun dan jumlah responden berjenis kelamin laki-laki sebesar 16 orang dan perempuan sebanyak 84 orang. Teknik penarikan sampel menggunakan voluntary sampling. Kuesioner dibuat dalam bentuk gform dan link disebarkan pada pertengahan bulan April 2021. Analisis data menggunakan uji deskriptif dan SEM-PLS. Hasil SEM-PLS menunjukkan adanya pengaruh yang signifikan jenis kelamin terhadap pengetahuan dan perilaku mencegah terinfeksi Covid-19 serta sikap terhadap perilaku mencegah terinfeksi Covid-19. Hal ini menunjukkan bahwa perempuan memiliki pengetahuan dan perilaku menhadapi pandemi Covid19 lebih tinggi dari pada laki-laki serta sikap yang baik akan meningkatkan perilaku mencegah terinfeksi Covid-19. Sosialisasi dan perilaku mencegah terinfeksi Covid-19 perlu ditingkatkan terutama kepada generasi Y laki-laki. Kata kunci : Covid-19, Generasi Y, pengetahuan, perilaku mencegah, sikap, Generation Y has the highest proportion of cases infected with Covid-19. This is due to the high mobility and activities outside the home. This study aims to analyze the effect of individual characteristics, knowledge, and attitudes on behavior to prevent infection with Covid-19 in Ponorogo. The sample in the study amounted to 100 people with an age range of 20-35 years and the number of male respondents was 16 people and women were 84 people. The sampling technique used is voluntary sampling. The questionnaire was made in the form of a form and a link was distributed in mid-April 2021. Data analysis used descriptive tests and SEM-PLS. The results of the SEM-PLS show that there is a significant influence of gender on knowledge and behavior to prevent infection with Covid-19 as well as attitudes towards behavior in dealing with the Covid-19 pandemic. This shows that women have higher knowledge and behavior in dealing with the Covid-19 pandemic than men and a good attitude will increase behavior to prevent infection with Covid-19. Socialization and behavior in dealing with the Covid-19 pandemic need to be improved, especially for the male Y generation.
Keyword: Pengetahuan, Sikap, Perilaku Mencegah Terinfeksi, Covid-19, Generasi Y

Judul: Profile Clean and Healthy Lifestyle and Food Consumption of Adolescents to Prevent the Transmission of Covid-19
Abstrak: Penelitian bertujuan menganalisis profil Perilaku Hidup Bersih dan Sehat (PHBS) dan mempelajari konsumsi pangan remaja dalam mencegah penularan Covid-19. Desain penelitian ini adalah cross sectional dengan jumlah subjek 102 orang yang dipilih secara purposive sampling. Pengambilan data dilakukan dengan pengisian kuesioner dan FFQ self-administered secara daring dan wawancara Recall 2x24 Hours melalui telepon. Sikap subjek menghadapi Covid-19 sebagian besar tergolong baik (55,3%). PHBS subjek dalam mencegah Covid-19 memiliki persentase baik dan kurang baik yang sama (50%). Perilaku makan sebagian besar tergolong baik (57,8%). Tingkat kecukupan rata-rata energi, protein, lemak, karbohidrat, vitamin A, dan vitamin C subjek tergolong defisit, namun Fe dan Zn tergolong cukup Terdapat hubungan signifikan (p<0,05) antara sikap menghadapi Covid-19 dengan jenis kelamin (p=0,016), usia (p=0,038), dan pekerjaan ibu (p=0,042). Penerapan PHBS dalam mencegah Covid-19 memiliki hubungan signifikan (p<0,10) untuk pendidikan ibu (p=0,053), pekerjaan ayah (p=0,083), pekerjaan ibu (p=0,007), dan pendapatan keluarga (p=0,011). Terdapat hubungan sangat signifikan (p<0,01) antara perilaku makan dalam mencegah Covid-19 dengan status gizi (p=0,004). Tidak terdapat hubungan signifikan antara sikap subjek menghadapi Covid-19 terhadap PHBS dan perilaku makan, namun terdapat hubungan searah positif sangat signifikan (p<0,01) antara PHBS dan perilaku makan (p=0,000, r=0,414)., The research aims to analyze profile Clean and Healthy Life Style (PHBS) and food consumption of adolescents to prevent the transmission of Covid-19. The design of this study was cross-sectional with 102 subjects selected by purposive sampling. Data were collected by filling out self-administered online questionnaires and FFQ, and Recall 2x24 Hours by telephone. Most of the subjects' attitudes towards Covid-19 were good (55.3%). PHBS subjects to prevent Covid-19 have the same percentage 50% for good and not good. Most of the eating behavior is classified as good (57.8%). The average adequacy level of energy, protein, fat, carbohydrates, vitamin A, and vitamin C is classified as a deficit, but Fe and Zn are considered sufficient. There is a significant relationship (p<0.05) between attitudes towards Covid-19 with gender (p=0.016), age (p= 0.038), and mother's occupation (p=0.042). The implementation of PHBS to prevent Covid-19 had a significant relationship (p<0.10) between the mother's education (p=0.053), father's occupation (p=0.083), mother’s occupation (p=0.007) and family income (p=0.011). There is a significant relationship (p<0.01) between eating behavior to prevent Covid-19 and nutritional status (p=0.004). There is no significant relationship between the subject's attitude towards Covid-19 with PHBS and eating behavior, but there is a significant positive direction relationship (p<0.01) between PHBS and eating behavior (p=0.000, r=0.414).
Keyword: Adolescents, Covid-19, eating behavior, food consumption, PHBS

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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