Judul: Desain Bangunan Spillway dan Bangunan Intake Situ Gede, Kota Bogor.
Abstrak: Bangunan pelimpah (spillway) adalah bangunan pelengkap suatu situ yang berfungsi untuk mengalirkan kelebihan air agar tidak membahayakan tubuh situ. Bangunan intake adalah suatu unit untuk mengambil air baku dari badan air sesuai dengan debit yang diperlukan. Tujuan penelitian ini adalah menganalisis debit andalan dan debit banjir, membuat kurva lengkung kapasitas, merancang dimensi bangunan intake dan spillway. Debit andalan dihitung dengan menggunakan metode Mock dan debit banjir menggunakan metode Rasional. Debit andalan yang didapat sebesar 1.66 l/det, dan debit banjir sebesar 32.3 m3/det yang dibagi ke dalam 5 daerah tangkapan air. Dari kurva lengkung didapat volume hidup situ sebesar 2662.84 m3 pada elevasi +174.05 m. Pada perancangan dipilih bangunan intake bertipe pipa distribusi (pipa intake) dengan dimensi panjang 128 m, dan beda ketinggian hulu-hilir sebesar 0.2 m serta terletak 1.25 m di bawah muka air situ maksimum. Bangunan intake dapat mengalirkan debit sebesar 0.0098 m3/det. Bangunan spillway dirancang dengan mempertimbangkan aspek estetika untuk memikat para wisatawan sehingga dipilih bangunan spillway tipe ogee. Bangunan spillway memiliki kedalaman dasar 1.5 m, panjang bentang 22 m membentuk setengah lingkaran, lebar 3 m, dan peredam energi sepanjang 2 m. Bangunan spillway dirancang untuk mengalirkan debit sebesar 11 m3/det.
Keyword: debit andalan, debit banjir, kurva lengkung kapasitas, tipe ogee

Judul: Kajian Dimensi Bangunan Spillway
Abstrak: Bangunan spillway merupakan bangunan hidrolika dari suatu bendungan yang berfungsi pada saat keadaan darurat (emergency), yaitu keadaan muka air pada saat volume tampungan banjir maksimum. Penelitian ini bertujuan untuk melakukan kaji ulang bangunan spillway pada Bendungan Randugunting berdasarkan kajian terhadap desain existing bangunan spillway, debit rencana bangunan spillway, kedalaman aliran kritis, dan profil muka air bangunan spillway. Tipe bangunan spillway yang direncanakan adalah tipe side spillway dengan tipe mercu Ogee. Hasil analisis luas catchment area Sungai Banyuasin adalah 17.39 km2 dengan panjang sungai 8.52 km. Nilai curah hujan rencana dengan periode ulang 1000 tahun adalah sebesar 180.40 mm. Hasil analisis debit rencana metode rasional sebesar 124.07 m3/det, sedangkan dengan metode HSS Nakayasu distribusi hujan 2 jam sebesar 207.40 m3 /det. Kedalaman aliran kritis di atas mercu bendung bangunan spillway diperkirakan setinggi 1.39 m. Elevasi muka air pada saat banjir maksimum adalah 95.66 mdpl di atas mercu bendung spillway, 88.78 - 90.11 mdpl di segmen saluran samping, 88.23 - 88.78 mdpl di segmen saluran transisi, 61.34 - 88.62 mdpl di segmen saluran peluncur, dan 66.28 mdpl di segmen akhir peredam energi., Spillway is a hydraulics building of a dam that functions during an emergency, when the water level of the maximum flood storage volume. This study aims to review the spillway building on the Randugunting Dam based on a study of the existing design of the spillway building, the design discharge of the spillway building, the critical flow depth, and the water level profile of the spillway building. The planned type of spillway building is a side spillway type with an Ogee crest type. The analysis of Banyuasin River catchment area are 17.39 km2 with the river length of 8.52 km. The result of the planned rainfall with a return period of 1000 years is 180.40 mm. The result of discharge with rational method is 124.07 m3/s, while with the Nakayasu HSS method the 2-hour rain distribution is 207.40 m3/s. The critical depth above the weir crest is estimated to be 1.39 m. The maximum water level during flooding is 95.66 masl above the spillway weir crest, 88.78 - 90.11 masl in the side channel segment, 88.23 - 88.78 masl in the transition channel segment, 61.34 - 88.62 masl in the drop channel segment, and 66.28 masl in the stilling basin segment.
Keyword: Critical flow depth, design discharge, water surface profile

Judul: Pengaruh Jumlah Bahan Pretanning dan Minyak Biji Karet (Hevea brasiliensis) Terhadap Mutu Kulit Samoa. Di
Abstrak: Animal hides or skins are the most valuable by product of the meat industry. Most of those hides are converted into leather by leather tanning process. Chrome based tanning is the most popular tanning process. At the chrome based tanning process, a lot of amount chrome are throw away into the environment that make a significant effect to the biological and ecological environment damaged. Due to concerns over the use and disposal of chromed tanned leather, the leather industry is now facing increasing scrutiny over its use of chrome as tanning agent. The use of non-chrome tannages has gradually become pre-eminent to producing leather, particularly in the European automotive leather markets. Chamois leather is one of leather product. It is produced from animal hides/skins by oil tanning process, usually with fish oil. High price and odour problems to the chamois leather that produced using fish oil motivate to do some research to solve that problems. Rubber seed oil is an oil that predicted can substitute fish oil. Pretanning process is needed to increase the oil penetration and protects the pelt from putrefying during oxidation periods (Khrisnan et al., 2005). Relugan GT 50 is the agent that used on this research. Relugan GT 50 is an aldehyde tanning agent, produced by BASF. This research was aimed to find out the effects of Relugan GT 50 concentration (offer) and rubber seeds (Hevea brasiliensis) oil to the chamois leather’s quality. Beside that, this research is also aimed to decide the best combination of the factors to produce chamois leather also to know the chamois leather characteristics. The preliminary research was carried out by analyzing the rubber seed’s kernel and eggshell as well as physico-chemical properties of the rubber seed oil. The main research was done by tanning the skin with Relugan GT 50 in concentrations of 1.5, 3.0 and 4.5% followed by rubber seed oil concentrations of 10, 20, and 30%. The experimental design used was completely randomize factorial design. The preliminary research shows that rubber seed’s kernel was 49% and rubber seed’s eggshell was 51%. The rubber seed’s oil characterstics were density of 0.94 (g/cm3), viscosity of 48,4 centistokes, colour of 2713 PtCo units, inodine value 113 g iod/ 100 g, peroxide value of 24 miliequivalent/1000 gram oil, acid value of 15 mg KOH/g oil and FFA content of 5.8%. The research shows that Relugan GT 50 concentration significantly affected shrinkage temperature (Ts) and pH; rubber seed oil concentration significantly affect the organoleptic properties of the leather. The optimum conditions for the tanning were Relugan GT of 3.0% concentration and 10% rubber seeds oil. The physical properties of the leather were shrinkage temperature of 75oC, thickness of 0.92 mm, tensile strength of 21.50 N/mm2, elongation at break of 144%, tear strength of 55.77 N/mm, water absorption of 266% (2 hours) and 299% (24 hours). The chemical properties were oil content of 2.5%, ash content of 1.2% and pH of 8. The organoleptic properties were softness of 7–8, colour of 8-9, and odour of 8-9.
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