Judul: Pendugaan Limpasan Langsung dalam Penelusuran Banjir di Daerah Aliran Sungai Ciliwung
Abstrak: Debit aliran sungai sangat dipengaruhi oleh variasi hujan. Limpasan langsuug yang dimaksudkan adalah limpasan laugsung yaug meuyebabkan teijadinya banjir dalam suatu daerah tertentu, dengan meugasumsikan bahwa baujir yang terjadi disebabkau oleh curah hujan yang turun dalam daerah tersebut. Debit air sungai yang dikorelasikan deugan hujan dapat membantu perkiraan banjir. Untuk mendapatkan hubungan curah hujan deugan limpasan dapat dilakukan dengan menghubungkan besarnya limpasan langsung terhadap hujan-hujan yang mendahului. Model hidrologi limpasan (run-off model) yang digunakan dalam penelusuran banjir pada DAS menggunakan metode Muskingum dimana storage merupakan fungsi dari inflow dan outflow. Peuelitian ini bertujuan uutuk mempelajari besarnya limpasan langsung dalam penelusuran banjir pada DAS Ciliwung, dengan menggunakan model penelusuran metode Mushgum, dan menetapkau nilai parameter model
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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: Responses on Performance and Minerals Digestibility by Novel Consensus Bacterial 6-Phytase  Variant (PHY-G) Supplementation in Broiler Diet
Abstrak: Plant feedstuffs normally contain phytic acid which poorly hydrolized by monogastric especially broiler. Further, 80% of phosphorus (P) in plant feedstuff is complexed with phytic acid. In that case, high amount of inorganic P sources is needed to fulfill P requirement. Since it has capability to bind with some nutrients such as bi- or trivalent minerals and amino acids then phytase is widely utilized in poultry feed to improve the nutrient digestibility. Today, the use of 500-1000 FTU phytases in poultry feed is widely applied by feed industry and its capability releasing phytate-bound phosphorus is very well documented. Novel consensus bacterial 6-phytase variant (PHY-G) is newest 6-phytase derived from bacterial phytase gene Buttiauxella sp. expressed in Trichoderma reesei with enhanced functionality for better phytic acids degradation. The present research was conducted to evaluate the efficacy of PHY-G in different doses (1000, 1500 and 2000 FTU/kg) on high phytic acids content diets which at least contained 0.30% Phytate-P. A total 3,675 male broilers Indian River/IR (105 pens, 35 birds/pen) were provided mixed grain diets in seven treatments with fifteen replications, they were divided into two phases of rearing which were starter (1 – 21 d) and finisher (22 – 35 d). Treatments were positive control (PC) using standard diet following IR’s nutrient requirement, negative control 1 (NC1) with nutrient reduction at 0.21 percent unit calcium (Ca), 0.21 percent units available phosphorus (AvP), 0.34 percent unit crude protein (CP) and 66 kcal/kg AME, NC2 with nutrient reduction at 0.23 percent unit Ca & AvP, 0.45 percent unit CP and 75 kcal/kg AME, followed by NC3 with nutrient reduction at 0.24 percent unit Ca & AvP, 0.52 percent unit CP and 79 kcal/kg AME. PHY-G supplementation with dose 1000, 1500 and 2000 FTU/kg on top of NC1, NC2 and NC3 respectively. PHY-G supplementation at any level significantly improved body weight gain/BWG and corrected FCR/McFCR (P<0.05) on starter (1,083 – 1,093 g/bird) and overall phase (2,482 – 2,532 g/bird) compared to any NCs (1,063-1,084 g/bird on starter and 2,387 – 2,398 g/bird on finisher). No significant different were observed on mortality of all treatments but PHY-G supplementation significantly improved (P<0.05) broiler index/BI (444 - 463) versus NCs (427 - 430) and able to maintain it equivalent to PC (455). Toe ash was significantly improved (P<0.05) by all doses of PHY-G (13.28 – 13.56%) compared to NC (12.3 – 12.7%). Apparent ileal digestibility (AID) of Ca was not affected by PHY-G but 1000, 1500 and 2000 FTU/kg PHY-G supplementation significantly improvemed on AID of P (P<0.05) which were 64.97%, 75.60% and 78.29% compared to NCs (42.64%, 48.88% and 46.17% for NC1, NC2 and NC3 respectively). This These data indicated that PHYG supplementation effectively improved broiler growth performance, bone mineralization and P digestibility at any level of dose on high content of phytic acid in the diets.
Keyword: broiler, growth performance, phytase, phytic acid, toe ash