Judul: Pengembangan indikator sistem peringatan dini dan teknik prakiraan debit banjir sungai Cimanuk, Development of some indicators of flood warning system and flood forecasting technique at Cimanuk river
Abstrak: This study was carried out in Cimanuk watershed, located in West Java. Cimanuk river flows through the district of Garut, Sumedang, Majalengka, and Indramayu. The river has three tributaries: Cilutung, Cimanukhulu, and Cipeles rivers; the outlets of each tributary are respectively at Kamun, Eretan and Warungpeti stations. The lowest flood monitoring station on Cimanuk river is at Monjot. The river caused annual floods to down stream and some of the floods caused serious damage. To reduce the damage and to anticipate floods it is necessary to develop a flood early warning system., This study was carried out in Cimanuk Watershed, located in West Java. Cimanuk river flows through the district of Garut, Sumedang, Majalengka, and Indramayu. The river has three tributaries: Cilutung, Cimanukhulu, and Cipeles rivers; the outlets of each tributary are respectively at Kamun, Eretan and Warungpeti stations. The lowest flood monitoring station on Cimanuk river at Monjot. The river caused annual the damage and to anticipate floods caused serious damage. To reduce the damage and to anticipate floods it is necessary to develop a flood early warning system.
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Judul: Indikator Sistem Peringatan Dini Banjir Subdas Citarik
Abstrak: SubDAS Citarik sebagai bagian dari DAS Citarum Hulu terus mengalami peningkatan kejadian banjir sehingga mengakibatkan kerugian yang cukup besar di berbagai sektor. Perlu adanya sistem peringatan dini banjir atau Flood early warning system (FEWS) guna mengurangi kerugian yang terjadi. Penelitian ini bertujuan untuk mengidentifikasi komponen yang dapat digunakan sebagai indikator peringatan dini banjir subDAS Citarik. Metode yang digunakan yakni analisis regresi linier berganda untuk mengetahui hubungan dan pengaruh curah hujan terhadap tinggi muka air (TMA) banjir. Sistem peringatan dini banjir subDAS Citarik belum dikembangkan ataupun diterapkan secara maksimal sehingga perlu dibangun indikator peringatan dini di daerah kajian. Sistem peringatan dini banjir subDAS Citarik belum dikembangkan ataupun diterapkan secara maksimal sehingga perlu dibangun indikator peringatan dini di daerah kajian. Sistem peringatan dini banjir subDAS Citarik dapat diidentifikasi oleh TMA banjir Bd. Cangkuang. Ambang batas TMA banjir Bd. Cangkuang sebesar 0.93 meter. Komponen yang mempengaruhi pembentukan TMA banjir Bd. Cangkuang adalah TMA tiga hari sebelum banjir sebesar 0.63 meter diiringi akumulasi curah hujan st. Rancaekek sebesar 77 mm. Komponen penyebab banjir tersebut dapat menjelaskan TMA banjir Cangkuang cukup signifikan yaitu sebesar 71%.
Keyword: Indikator FEWS, Regresi berganda, Banjir

Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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