Judul: Correlation between Eating Habits and Diet Quality with Learning Concentration of Adolescents in SMPN 2 Cibungbulang Bogor
Abstrak: Permasalahan gizi menyebabkan perkembangan otak kurang optimal, berdampak negatif pada fungsi kognitif, kemampuan belajar, konsentrasi dan produktivitas. Penelitian ini bertujuan menganalisis hubungan kebiasaan makan dan kualitas diet dengan konsentrasi belajar remaja di SMPN 2 Cibungbulang. Desain penelitian ini cross sectional study melibatkan 35 siswa kelas VII, dilaksanakan pada Februari-Mei 2024. Data asupan didapatkan melalui food recall 2x24 jam, kualitas diet diukur menggunakan Diet Quality Index for Adolescent (DQI-A), konsentrasi belajar menggunakan Digit Symbol Substitution Test (DSST). Hampir setengah subjek (42,9%) memiliki kebiasaan sarapan 5-7 kali/minggu. Kontribusi energi, protein dan lemak sarapan tergolong cukup, sedangkan karbohidrat kurang. Subjek memiliki kebiasaan makan 3 kali sehari dengan tingkat kecukupan energi, protein dan karbohidrat tergolong defisit, sedangkan lemak tergolong lebih dari rekomendasi. Sekitar tiga perempat subjek (77,1%) memiliki status gizi (IMT/U) baik. Rata-rata skor DQI-A subjek sebesar 36,41% ± 4,35% dan tergolong rendah. Rata-rata skor DSST 37,69 ± 9,37 dan tergolong kurang baik. Tidak terdapat hubungan signifikan antara kebiasaan makan dengan kualitas diet, kualitas diet dengan status gizi dan konsentrasi belajar (p>0,05). Hubungan signifikan ditemukan antara kontribusi energi, lemak dan karbohidrat sarapan serta tingkat kecukupan protein dengan konsentrasi belajar (p<0,05). Penelitian ini memberikan tambahan bukti pentingnya kebiasaan sarapan dan kualitas diet terhadap konsentrasi belajar., Nutritional problems can lead to suboptimal brain development which negatively impact cognitive function, learning ability, concentration, and productivity. This study aims to analyze the relationship between eating habits and diet quality with adolescent learning concentration at SMPN 2 Cibungbulang. The research design was a cross-sectional study involved 35 students of class VII and conducted in February-May 2024. Food intake was obtained through 2x24 hour food recall, diet quality was measured using the Diet Quality Index for Adolescent (DQI-A) and learning concentration using the Digit Symbol Substitution Test (DSST). Almost half of the subjects (42.9%) had breakfast 5-7 times/week. The breakfast energy, protein and fat contribution was adequate, while the breakfast carbohydrates contribution was inadequate. Subjects had the habit of eating 3 times a day with adequacy level of energy, protein and carbohydrates classified as deficit, while fat was classified as over the recommedation. Around three quarters of subject (77,1%) had good nutritional status (IMT/U). The average DQI-A score was 36.41% ± 4.35% and classified as low. The average DSST score was 37.69 ± 9.37 and classified as poor. There was no significant relationship between eating habits and diet quality and diet quality with nutritional status and learning concentration (p>0.05). On the other hand, a significant relationship was found between the breakfast energy, fat and carbohydrates contribution and adequacy level of protein with learning concentration (p<0.05). This research enrich the evidence the importance of breakfast habits and diet quality on learning concentration.
Keyword: Kebiasaan Makan, kualitas diet, Konsentrasi Belajar, DQI-A

Judul: Correlation between Breakfast Habits, Nutritional Status, and Sleep Quality with Study Concentration of Students
Abstrak: Konsentrasi merupakan kemampuan memusatkan pikiran atau perhatian pada suatu hal. Konsentrasi belajar sangat diperlukan siswa agar dapat memaksimalkan potensi dan mencapai hasil pendidikan yang lebih optimal. Penelitian ini bertujuan mengidentifikasi hubungan kebiasaan sarapan, status gizi, dan kualitas tidur dengan konsentrasi belajar siswa. Desain penelitian menggunakan cross sectional study dengan melibatkan 70 subjek yang dipilih secara purposive sampling. Data karakteristik subjek dan keluarga subjek diperoleh melalui pengisian kuesioner dan wawancara, kebiasaan sarapan menggunakan kuesioner kebiasaan sarapan dan food record selama 7 hari, status gizi diperoleh melalui pengukuran antropometri berat badan dan tinggi badan, kualitas tidur menggunakan kuesioner Pittsburgh Sleep Quality Indeks (PSQI), serta konsentrasi belajar menggunakan instrumen Digit Symbol Substitution Test (DSST). Frekuensi kebiasaan sarapan sebagian besar subjek (51,4%) tergolong selalu (setiap hari) dengan waktu sarapan sebelum pukul 09.00 pagi. Tingkat kecukupan energi, protein dan karbohidrat sarapan sebagian besar subjek tergolong cukup, namun tingkat kecukupan lemak sarapan tergolong kurang. Mayoritas subjek (68,6%) memiliki status gizi baik, 61,4% memiliki kualitas tidur yang tergolong buruk, serta konsentrasi belajar yang tergolong baik (51,1%). Hasil penelitian menunjukkan bahwa tidak terdapat hubungan yang signifikan (p>0,05) antara frekuensi sarapan, waktu sarapan, tingkat kecukupan energi, protein, lemak, dan karbohidrat, status gizi, serta kualitas tidur dengan konsentrasi belajar siswa.
Keyword: breakfast habits, nutritional status, sleep quality, study concentration

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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