Judul: Land Cover Change in Leuwiliang District, Bogor  Regency During 2015 and 2020 Using Landsat Image 8
Abstrak: Pertambahan jumlah penduduk mengakibatkan perubahan pemanfaatan tata guna lahan yang ada di Kecamatan Leuwiliang. Perubahan pemanfaatan tata guna lahan dapat diketahui dengan cara menganalisis perubahan tutupan menggunakan citra Landsat 8 (OLI) perekaman tahun 2015 dan 2020. Metode klasifikasi tutupan lahan dilakukan menggunakan klasifikasi terbimbing yang kemudian dilakukan analisis perubahan tutupan lahan dengan cara membandingkan hasil klasifikasi tahun 2015 dan 2020. Klasifikasi tutupan lahan menghasilkan 8 kelas tutupan lahan yang dapat terindentifikasi berupa badan air, pertanian lahan basah, pertanian lahan kering, lahan terbangun, lahan kosong, perkebunan, hutan, dan semak belukar. Hasil klasifikasi menunjukkan nilai akurasi yang tinggi sebesar 94,49% pada Kappa Accuracy. Perubahan peningkatan luas kelas tutupan lahan paling tinggi terjadi pada kelas pertanian lahan kering sebesar 1481,42 ha, sedangkan perubahan penurunan luas kelas tutupan lahan paling tinggi terjadi pada kelas hutan sebesar 2503,14 ha., Increased population in Leuwiliang District has resulted in changes in land usage. Changes in land use can be detected by studying cover changes between 2015 and 2020 using Landsat 8 (OLI) data. The land cover classification process is carried out using a supervised classification, which is then compared to the results of the 2015 and 2020 classifications to determine land cover changes. Land cover classification provides 8 different land cover classes: water bodies, wetland agriculture, dry land agriculture, developed land, vacant land, plantations, forests, and shrubs. The categorization findings indicate a high level of accuracy, with a Kappa Accuracy of 94.49%. The greatest change in land cover class occurred in the dry land agricultural class, which encompassed 1481.42 ha, whereas the greatest change in land cover class occurred in the forest class, which encompassed 2503.14
Keyword: citra satelit resolusi sedang, klasifikasi terbimbing, Leuwiliang, uji akurasi

Judul: Land Using Sentinel-2 Imagery in Sukamakmur District, Bogor Regency from 2018-2023
Abstrak: Pertumbuhan penduduk yang pesat mengakibatkan tingkat kebutuhan masyarakat terhadap lahan semakin meningkat sehingga menyebabkan terjadinya perubahan tutupan lahan. Penelitian ini bertujuan untuk mengidentifikasi dan menganalisis perubahan tutupan lahan di Kecamatan Sukamakmur Kabupaten Bogor menggunakan Citra Sentinel-2 tahun 2018–2023. Terdapat 9 kelas tutupan lahan yaitu hutan, sawah, kebun campuran, pertanian lahan kering, pemukiman, lahan terbuka tanah, semak, sungai, dan danau. Kelas tutupan lahan yang mengalami peningkatan adalah tutupan lahan hutan (83,40 ha), pertanian lahan kering (48,94 ha), sawah (6,35 ha), dan permukiman (1,08 ha). Sedangkan kelas tutupan lahan yang mengalami penurunan adalah kelas tutupan lahan semak belukar (80,97 ha), lahan terbuka (40,01 ha), dan perkebunan campuran (18,79 ha). Perubahan tutupan lahan yang terjadi di Kecamatan Sukamakmur Kabupaten Bogor menunjukkan sebesar 73,86% mengalami perubahan ke arah positif dan 26,14% mengalami perubahan ke arah negatif. Perubahan ke arah positif yang lebih besar menunjukkan bahwa cadangan karbon di Kecamatan Sukamakmur semakin meningkat sehingga tanaman mampu menyerap CO2 dari atmosfer lebih banyak dan menyimpannya dalam bentuk biomassa tanaman., Rapid population growth results in the level of people's need for land increasing, causing changes in land cover. This research aims to identify and analyze changes in land cover in Sukamakmur District, Bogor Regency using Sentinel-2 Imagery in 2018–2023. There are 9 land cover classes, namely forest, rice fields, mixed gardens, dry land agriculture, settlements, open land, bushes, rivers, and lakes. The land cover classes that experienced an increase were forest land cover (83.40 ha), dry land agriculture (48.94 ha), rice fields (6.35 ha), and settlements (1.08 ha). Meanwhile, the land cover classes that experienced a decline were the land cover classes of shrubs (80.97 ha), open land (40.01 ha), and mixed plantations (18.79 ha). Land cover changes that occurred in Sukamakmur District, Bogor Regency showed that 73.86% experienced changes in a positive direction and 26.14% experienced changes in a negative direction. Changes in a greater positive direction indicate that carbon reserves in Sukamakmur District have increased so that plants are able to absorb more CO2 from the atmosphere and store it in the form of plant biomass.
Keyword: tutupan lahan, sentinel-2, Sukamakmur

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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