Judul: The Correlation between Nutritional Knowledge, Eating Habits, and Physical Activity with Nutritional Status among Student of SMAN 1 Kebumen
Abstrak: Prevalensi remaja gemuk usia 16-18 tahun di Indonesia meningkat pada tahun 2018. Kegemukan pada remaja dapat menimbulkan dampak negatif terkait aspek kesehatan dan psikososial. Penelitian ini bertujuan menganalisis hubungan pengetahuan gizi dengan kebiasaan makan, hubungan kebiasaan makan dengan status gizi, dan hubungan aktivitas fisik dengan status gizi siswa SMAN 1 Kebumen. Penelitian dilakukan pada Mei 2023 menggunakan desain cross sectional, melibatkan 30 remaja normal dan 30 remaja gemuk yang dipilih secara purposive. Data primer diperoleh melalui pengisian kuesioner dan wawancara berupa data karakteristik individu, karakteristik keluarga, pengetahuan gizi, aktivitas fisik, dan kebiasaan makan. Hasil uji beda menunjukkan tidak terdapat perbedaan signifikan (p>0,05) pengetahuan gizi, aktivitas fisik dan duduk, tingkat kecukupan energi dan zat gizi, asupan gula, serta kebiasaan pangan sumber gula dan lemak antara kedua kelompok subjek, namun kelompok subjek gemuk signifikan lebih banyak asupan lemaknya (p<0,05). Hasil uji korelasi menunjukkan hubungan signifikan positif antara asupan lemak dengan status gizi (p=0,01). Tidak terdapat hubungan signifikan pengetahuan gizi dengan kebiasaan pangan sumber gula dan lemak, asupan gula dan lemak, serta tingkat kecukupan energi dan zat gizi. Tidak terdapat perbedaan signifikan kebiasaan pangan sumber gula dan lemak, asupan gula, tingkat kecukupan energi dan zat gizi, dan aktivitas fisik dengan status gizi (p>0,05)., Prevalence obese adolescents aged 16-18 years in Indonesia increased in 2018. Obesity in adolescents have negative impacts related to health and psychosocial. This study aims to analyze correlation nutritional knowledge and eating habits, correlation eating habits and nutritional status, and correlation physical activity and nutritional status students at SMAN 1 Kebumen. Study was conducted in May 2023 using a cross-sectional design, involving 30 normal and 30 obese adolescents that selected purposively. Primary data was obtained through questionnaires and interviews with individual characteristics, family characteristics, nutritional knowledge, physical activity, and eating habits. There was no significant difference (p>0.05) nutritional knowledge, physical activity and duration of sitting, energy and nutrients adequacy level, sugar intake, and eating habits of food sources sugar and fat between two subject, but obese subjects had significantly higher fat intake (p<0.05). There was a significant positive correlation fat intake and nutritional status (p=0.01). There was no significant correlation nutritional knowledge with eating habits of food sources sugar and fat, intake sugar and fat, also energy and nutrients adequacy level (p>0.05). There was no significant correlation eating habits of food sources sugar and fat, sugar intake, energy and nutrients adequacy level, and physical activity with nutritional status (p >0.05).
Keyword: eating habits, nutritional knowledge, nutritional status, normal and obes adolescents, physical activity

Judul: Correlation between Fat Intake, Vegetables and Fruits Consumption, and Physical Activity with Overweight and Obesity in Adolescents
Abstrak: Prevalensi remaja kegemukan terus meningkat selama satu dekade terakhir. Peningkatan tersebut didorong oleh kebiasaan remaja yang kurang baik dalam mengonsumsi pangan dan aktivitas fisik yang kurang. Oleh karena itu, penelitian ini bertujuan untuk menganalisis keterkaitan antara asupan lemak, konsumsi sayur dan buah, serta aktivitas fisik dengan status gizi remaja. Penelitian dengan desain studi comparative cross-sectional ini, melibatkan 46 subjek gemuk dan 46 subjek status gizi normal. Hasil penelitian menunjukkan terdapat 29,3% subjek dari kedua kelompok memiliki asupan lemak berlebih. Seluruh subjek dari kedua kelompok dinilai kurang mengonsumsi sayur dan buah. Sebanyak 77,2% subjek dari kedua kelompok memiliki tingkat aktivitas fisik kategori ringan. Asupan lemak subjek gemuk signifikan lebih tinggi daripada subjek status gizi normal (p=0,015). Hasil uji korelasi menunjukkan bahwa asupan lemak berkorelasi positif dengan status gizi (p=0,050; r=0,205), sedangkan aktivitas fisik berkorelasi negatif dengan status gizi (p=0,032; r=-0,224). Tidak ditemukan korelasi yang signifikan antara konsumsi sayur dan buah dengan status gizi (p>0,05), namun rata-rata konsumsi sayur buah subjek status gemuk dinilai lebih rendah daripada subjek status normal. Hasil tersebut mengindikasikan bahwa penting untuk mengontrol asupan lemak, meningkatkan konsumsi sayur buah, dan aktivitas fisik untuk mencapai status gizi normal., The prevalence of overweight and obesity in adolescents has been steadily increasing over the past decade. This was driven by adolescents’ poor eating habits and lack of physical activity. Therefore, this study aimed to analyze the correlation between fat intake, vegetables and fruits consumption, and physical activity with adolescents’ nutritional status. This comparative cross-sectional study design involved 46 overweight obese subjects and 46 normal nutritional status subjects. There were 29,3% subjects of both groups that had excessive fat intake. All subjects were considered not consuming enough vegetables and fruits. There were 77,2% subjects of both groups that had a mild level of physical activity. Fat intake of overweight obese subjects was significantly higher than normal subjects (p=0,015). The correlation test results showed that fat intake was positively correlated with nutritional status (p=0,050; r=0,205), while physical activity was negatively correlated with nutritional status (p=0,032; r=-0,224). No significant correlation was found between vegetables and fruits consumption with nutritional status (p>0.05), but the average vegetable fruit consumption of normal nutritional status subjects was higher than overweight obese subjects. These results indicated that it is important to control fat intake, increase fruits and vegetables consumption, and physical activity to get normal nutritional status.
Keyword: fat intake, overweight and obesity, physical activity, vegetable and 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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