Judul: Identifiaction of Changes in Land Cover and Rainfall in Bogor in 1991-2020 using Cloud Computing Technology
Abstrak: Perubahan tutupan lahan bervegetasi menjadi lahan terbangun berdampak pada cuaca disekitarnya, salah satunya adalah curah hujan. Penelitian ini mengidenfikasi perubahan tutupan lahan dan curah hujan di Bogor pada rentang tahun 1991-2020. Identifikasi perubahan tutupan lahan menggunakan data satelit Landsat 5, 7, dan 8 yang diolah dengan Google Earth Engine (GEE). Data hujan yang digunakan merupakan data hasil pengamatan di stasiun BMKG Citeko dan Dramaga. Analisis perubahan tutupan lahan menggunakan statistik deskriptif dan uji akurasi kappa. Hasil penelitian menunjukkan perubahan tutupan lahan terbangun memiliki tingkat akurasi sebesar 86,79% dan indeks kappa 0,8. Tren lahan terbangun bernilai positif, sedangkan tutupan vegetasi negatif. Tren curah hujan pada kedua stasiun bernilai negatif. Tutupan lahan terbangun mengalami peningkatan seluas 845 km2 dari tahun 1991-2020 dan tutupan vegetasi berkurang seluas 838 km2 . Perubahan tutupan lahan berhubungan dengan perubahan curah hujan melalui faktor-faktor meteorologis yang berperan dalam proses fisis kejadian hujan. Faktor meteorologis tersebut antara lain adalah suhu udara, radiasi, kecepatan dan arah angin. Hasil ini dapat memberikan informasi dan meningkatkan wawasan kepada para pihak terkait tentang dampak dari perubahan lahan terhadap kondisi iklim. Penelitian lebih lanjut perlu melakukan analisis kuantitatif hubungan antara unsur-unsur cuaca dengan tutupan lahan., Changes in vegetated land cover to built-up land have an impact on the surrounding weather, one of which is rainfall. This study identified changes in land cover and rainfall in Bogor in the 1991-2020 range. Identification of land cover changes using Landsat 5, 7 and 8 satellite data processed with the Google Earth Engine (GEE). The rain data used is observational data at the BMKG Citeko and Dramaga stations. Analysis of land cover change using descriptive statistics and kappa accuracy test. The results showed that changes in built-up land cover had an accuracy rate of 86.79% and a kappa index of 0.8. The trend of built-up land is positive, while the vegetation cover is negative. Rainfall trends at both stations are negative. The built-up land cover increased by 845 km2 from 1991-2020 and the vegetation cover decreased by 838 km2 . Changes in land cover are related to changes in rainfall through meteorological factors that play a role in the physical processes of rain events. These meteorological factors include air temperature, radiation, wind speed and direction. These results can provide information and increase insight to related parties about the impact of land use change on climate conditions. Further research needs to carry out a quantitative analysis of the relationship between weather elements and land cover.
Keyword: Google Earth Engine, land cover, Landsat, rainfall, supervised  classification

Judul: Dampak Dinamika Perubahan Tutupan Lahan Terhadap Suhu Udara di Kota dan Kabupaten Bogor
Abstrak: Perkembangan suatu kota yang sangat pesat mengakibatkan terjadinya perubahan dalam penggunaan lahan, yang mengakibatkan banyaknya perubahan pada lahan non terbangun beralih menjadi lahan terbangun seperti pembangunan infrastruktur fisik yang pesat dan tidak terencana membuat berkurangnya sebaran vegetasi. Penelitian ini bertujuan mengidentifikasi perubahan tutupan lahan dan dampaknya terhadap suhu udara di Kota Bogor dan Kabupaten Bogor. Perubahan tutupan lahan di Kota Bogor didominasi perubahan lahan vegetasi pohon berkurang berkisar 16,99% menjadi menjadi lahan bervegetasi campuran bertambah menjadi 7,04% dan lahan terbangun bertambah 10,6%, sementara kelas badan air mengalami penurunan hanya 0,65%. Dampak dari perubahan tutupan lahan terhadap suhu udara di Kabupaten Bogor masih lebih rendah dibandingkan Kota Bogor, karena tutupan lahan yang didominasi vegetasi pohon dan non pohon masih banyak ditemukan dan tidak memiliki perubahan yang signifikan jika dibandingkan dengan Kota Bogor yang memiliki jumlah tutupan lahan terbangun yang luas jika dibandingkan dengan vegetasi pohon dan non pohon., The very rapid development of a city results in changes in land use, which results in many changes in non-built land turning into built-up land such as the rapid and unplanned development of physical infrastructure that reduces the distribution of vegetation. This study aims to identify changes in land cover and their impact on temperature. air in the Bogor City and Regency of Bogor. Changes in land cover in Bogor City were dominated by land changes, tree vegetation decreased by 16.99% to mixed vegetation, increased to 7.04% and built-up land increased by 10.6%, while the class of water bodies decreased by only 0.65%. The impact of land cover changes in Regency of Bogor is still lower than Bogor City, because land cover dominated by tree and non-tree vegetation is still widely found and does not have significant changes when compared to Bogor City which has a large amount of built-up land cover compared to tree and non-tree vegetation.
Keyword: air temperature, change, land cover

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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