Judul: Pendugaan Limpasan atau Run-off di DAS Ciliwung Hulu dengan Menggunakan Artifical Neural Network
Abstrak: Dalam daur hidrologi, hujan merupakan komponen penting sebagai masukan terutama di dalam Daerah Aliran Sungai. Karakteristik hujan yang berpengaruh terhadap terjadinya limpasan atau Run-off adalah intensitas hujan. Intensitas hujan yang melebihi laju infiltrasi menyebabkan terjadinya limpasan permukaan. Dengan memahami komponen-komponen yang mendukung limpasan tersebut dapat dilakukan pendugaan. Pengembangan terhadap pendugaan Run-off tersebut dapat dibuat suatu model pendugaan Run-off. Alternatif pendugaan masih banyak perlu dilakukan untuk dapat menghasilkan ketelitian dan ketepatan yang tinggi.
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Judul: Pendugaan Debit Sungai Berdasarkan Hujan dengan Mnggunakan Model Tangki di Das Cibanau, Serang
Abstrak: Hiljan merupakan salah satu unsur iklim yang berpengaruh pada suatu DAS (Daerah Aliran Sungai). Pengaruh langsung yang dapat diketahui yaitu potensi sumber daya air. Besar kecilnya sumber daya air pada suatu DAS sangat tergantung dari jumlah curah hujan yang ada pada DAS. Potensi sumber air suatu DAS dapat diketahui dengan mengetahui limpasan total (debit) sungai. Model hidrologi limpasan (run-off model) yaitu model tangki dapat digunakan untuk menentukan besamya debit sungai. Penelitian ini bertujuan memodifikasi model tangki untuk menduga besamya limpasan total berdasarkan kejadian hujan dan membandingan secara langsung data keluaran model dengan data debit aktual. Modifikasi dilakukan terhadap DAS Cidanau yang terletak di Kabupaten Serang, Jawa Barat. DAS Cidanau dibagi menjadi 4 bagian tangki dengan tangki pertama mewakili daerah danau dengan luas 1500 ha, tangki kedua mewakili daerah hulu dengan luas sebesar 5000 ha, tangki ketiga mewakili daerah kebun dengan luas sebesar 13400 ha dan tangki keempat mewakili daerah sawahlrendah dengan luas 2720 ha.
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Judul: Enhancement of photon absorbtion on BaxSr1-xTiO3 thin films semiconductor using photonic crystals.
Abstrak: In this research, has been conducted BaxSr1-xTiO3 (BST) thin films manufacturing for mole fraction x = 0.25, 0.35, 0.45, and 0.55; and concentration of 1 molar using chemical solution depositon (CSD) method. The materials, which are used in this research, are barium acetate [Ba(CH3COO)2, 99%], strontium acetate [Sr(CH3COO)2, 99%], titanium isopropoxide [Ti(C12O4H28), 97.999%], gallium trioxide [Ga2O3], 2-methoxyethanol [H3COOCH2CH2OH, 99%] and 1 x 1 cm of transparent conductive oxide (TCO) glass as substrate. Two BST thin films are made that for BST thin films which are doped by 10% galium (BGST) as p-type layer and pure BST solution as n-type. BST solution is made by reacting barium acetate [Ba(CH3COO)2, 99%], strontium acetate [Sr(CH3COO)2, 99%] and titanium isopropoxide [Ti(C12O4H28)] into 2-methoxyethanol solvent [H3COOCH2CH2OH, 99%] in accordance with mass gram for each x value. While, BGST solution is made in the same way as BST solution, plus adding gallium at 10% of the mass of BST. Once all materials are reacted, then vibrated using ultrasonic for 90 minutes, and followed by coating BGST / BST on the TCO substrate. Once the layer is formed, then annealed for 15 hours at temperature of 500 °C with increasing rate of 1.67 oC/minute. Characterizations of BST thin films with or without photonic crystals include the absorbance and transmittance in the visible light spectrum, as well as the electrical photoconductivity characterizations. From BST thin films without photonic crystals indicate that our thin films have light absorption area on almost the entire range of the visible light spectrum even to the infrared range with absorption value over than 67.6%, in addition, it can be seen that the maximum absorbance of BST thin films for all mole fractions lie in blue to green light spectrum region, 457 nm ≤ λ ≤ 570 nm and the minimum in yellow to red light spectrum region, 570 nm ≤ λ ≤ 678 nm. The largest absorbance is found at x = 0.25 with average absorbance value of 92.04% and maximum and minimum absorbance peaks at wavelength of 500.89 and 657.72 nm, respectively. At x = 0.35, average absorbance value decreased to 83.55% with maximum and minimum peaks at 505.73 and 613.68 nm, respectively. Then increased to 91.16% at x = 0.45 with maximum and minimum peaks at 506.04 and 618.56 nm, respectively. At x = 0.55, average absorbance value decreased to 80.12% with maximum and minimum peaks at 507.85 and 608.79 nm, respectively. Moreover, it can be seen that the addition of barium mole fraction leads to wider maximum absorbance or minimum transmittance peaks and narrower minimum absorbance or maximum transmittance peaks in the same range of the green and blue & red light spectrums, respectively. BST thin films with photonic crystals show increasing in absorption for all x values in the range of 3.04 into 13.33%. At x = 0.25, average absorbance percentage increased 3.96% from 92.4 into 95.68%, for x = 0.35 average percentage increased 7.07% into 89.45 from 83.55%. Furthermore, average absorbance of BST thin films at x = 0.45 increased 3.04% from 91.16 into 93.93% and x = 0.55 has
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