Judul: Variasi Diurnal Cuaca Ekstrem Selama Periode Intensive Observational Period (IOP) 2015 (Studi Kasus: Bogor Jawa Barat).
Abstrak: Hujan lebat, badai, kekeringan, dan puting beliung merupakan fenomena cuaca ekstrim yang pernah terjadi di Indonesia. Hujan ekstrem adalah fenomena cuaca yang sering dibahas karena dapat menyebabkan kerugian dalam berbagai jenis aspek kehidupan. Proses terjadinya hujan ekstrem dapat dianalisis menggunakan kondisi atmosfer wilayah setempat dengan melakukan pengamatan udara atas. Tujuan dari penelitian ini adalah menjelaskan variasi diurnal cuaca ekstrem selama Intensive Observational Period (IOP) tahun 2015, menentukan parameter RAOB yang paling berpengaruh terhadap pembentukan hujan ekstrem, dan menjelaskan hubungan hujan di Bogor dengan banjir di DKI Jakarta. Data yang digunakan adalah Data Rawinsonde selama IOP 2015 di Bogor dari tanggal 1 sampai dengan 19 Februari 2015 dengan waktu pengamatan 00, 06, 12, 18 UTC dan Data Curah Hujan (AWS) perjam dari Stasiun BMKG Dramaga dan Citeko, Bogor. Parameter kondisi atmosfer yang perlu dikaji secara intensif untuk melakukan prediksi jangka pendek meliputi ketinggian tropopouse dengan kontribusi sebesar 50%, ketinggian puncak awan dilihat dari tinggi LFCEL dan CCLEL berturut-turut sebesar 67% dan 50%, tebal awan sebesar 67%, stabilitas atmosfer dilihat dari nilai Lifted Index (LI) dan K-Index (KI), serta besarnya kecepatan parsel udara naik ke atas (Mvv) masing-masing sebesar 83%. Kondisi angin juga mempengaruhi terjadinya hujan di suatu daerah. Saat terjadi hujan, arah angin di atmosfer bawah (dari permukaan sampai level 500 mb) tidak teratur, sedangkan saat tidak terjadi hujan arah angin di atmosfer bawah teratur. Hasil analisis menunjukkan bahwa selama IOP 2015 kondisi atmosfer tidak ekstrem, tetapi ada dua hari yaitu tanggal 9 dan 18 Februari yang cukup mendukung terjadinya hujan lebat skala lokal (setempat). Banjir besar yang terjadi di daerah DKI Jakarta dan sekitarnya pada periode IOP disebabkan oleh curah hujan ekstrem lokal di DKI Jakarta dan bukan banjir kiriman dari Bogor.
Keyword: cuaca ekstrem, kondisi atmosfer, variasi diurnal, rawinsonde, IOP

Judul: Analisis Curah Hujan Harian Maksimum dan Ekstrim di Kabupaten Bogor
Abstrak: The impact of extreme rainfall often cause serious problems for human being. However, the study of extreme rainfall is needed, so the impact of such extreme events can be anticipated as early as possible. This research aims to know the changes of extreme and maximum daily rainfall at some stations of Bogor Regency, and analyze the relationship between maximum daily rainfall with IOD condition (Indian Ocean Dipole) and SOI (Southern Oscillation Index). The analysis which used in this study are trend test using the Spearman Rank statistics and the probability distribution to acquire the probability of extreme rainfall and analyze maximum daily rainfall data with exceedence probability 5%, 10%, 25% and 50%. Correlation analysis was used to test the relationship between maximum daily rainfall with SOI and IOD. The results show that extreme rainfall occur in January, February and March, even occur in April. The most statistical distribution describes the maximum daily rainfall data in Bogor regency is Normal and Lognormal distribution. In some stasion, 3-Parameter Lognormal distribution, Gamma and Weibull can describes maximum daily rainfall data in dry season. The probability of extremes rainfall based on consecutively three day rainfall in region of this study is high enough, that is 0.80 at Gunung Mas, 0.23 at Katulampa, and 0.13 at Empang stasion. Generally, SOI and IOD significantly correlated and consistent on the maximum daily rainfall patterns in Bogor area in dry season and inconsistent in rainy season.
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Judul: Synthesis of Apatite - Chitosan Composite Using Duck Eggshell and Chitosan with Temperature and pH Control
Abstrak: Composite of apatite-chitosan was prepared by using chitosan as polymer matrix. Calcium phosphate was prepared from CaO and (NH4)2HPO4, which the ratio Ca : P had to be 1.67. Chitosan is produced by deacetilase from biopolymer chitin. Duck eggshell (95% CaCO3) as starting material was converted to be calcium oxide (CaO) through calcinations with temperature 1000oC for 5 hours. In-situ and ex-situ methods were prepared from apatite and chitosan (dissolved with acetate acid 2%). Calcium phosphate prepared for bone implantation, but it is too fragile and brittle to be implant into the body. So addition of chitosan can decrease crystalinity and increase mechanic characteristic (tougher). Composite apatite-chitosan was resulted by fast precipitation. Fast precipitation was held in a breaker glass with nitrogen atmosphere, under controlled temperature at 37oC and pH 7, in order to increase amount of hydroxyapatite. Precipitation with CaO which was dropped by (NH4)2HPO4. Hydroxyapatite and chitosan were appearing at samples with in-situ and ex-situ methods which indicating by peak matching of XRD (closed lattice parameter, crystal size), overlapping at FTIR spectra and supporting by SEM picture (homogenous and agglomerated particle). However, it still needs further research to examine biocompatibility osteoconductive degree of sample by in-vivo and in-vitro test.
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