Judul: Land Cover Changes Identification Using Sentinel-2 with Change Vector Analysis (CVA) Method.
Abstrak: Tutupan lahan diartikan sebagai kenampakan komponen biofisik permukaan bumi serta dideskripsikan menjadi tingkatan kelas yang menunjukan kumpulan biotik maupun abiotik dominan pada suatu wilayah. Perubahan tutupan lahan terjadi seiring dengan perkembangan zaman. Change Vector Analysis (CVA) merupakan metode yang menggunakan Normalized Difference Vegetation Index (NDVI) dan Normalized Difference Bare Land Index (NDBI) yang merupakan pengembangan dari metode image differencing. Penginderaan jauh pada penelitian ini menggunakan citra Sentinel-2 untuk foto perekaman wilayah Kabupaten-Kota Bogor. Tujuan penelitian ini untuk menganalisis perubahan tutupan lahan di Kabupaten-Kota Bogor tahun 2017 sampai 2022, mengidentifikasi besaran dan arah perubahan, dan menentukan nilai ambang batas setiap kelas perubahan. Metode CVA dapat mendeteksi besar dan arah perubahan dengan nilai magnitude dibawah 0,193 adalah no changes. Dengan periode waktu pengamatan yang hanya 5 tahun, perubahan ke arah vegetasi tidak terlalu signifikan., Land cover is defined as the appearance of the biophysical components on the earth's surface and is described into class levels that indicate the dominant biotic and abiotic groups in an area. Land cover changes occur over time. Change Vector Analysis (CVA) is a method that uses Normalized Difference Vegetation Index (NDVI) and Normalized Difference Bare Land Index (NDBI) in detecting dynamic changes in multi-time images which are the development of the image differencing method. Remote sensing in this study used Sentinel-2 imagery for photos of the Bogor Regency and City area. The purpose of this study was to analyze land cover change in Bogor Regency-City from 2017 to 2022, identify the magnitude and direction of change, and determine the threshold value for each class of change. The CVA method can detect the magnitude and direction of changes with a magnitude value below 0,193 is no changes. With an observation period of only 5 years, the change towards vegetation is not too significant.
Keyword: Tutupan Lahan, Change Vector Analysis, Sentinel-2, Kabupaten-Kota Bogor

Judul: Monitoring Perubahan Penggunaan/Tutupan Lahan di Kabupaten Bogor Periode 2000-2017 Menggunakan Teknik Change Vector Analysis (CVA)
Abstrak: Penelitian ini bertujuan untuk mengetahui dinamika perubahan/tutupan lahan (Land use/Land cover change/LULC) di Kabupaten Bogor, dengan mengidentifikasi besaran, arah, pola LULC selama periode tahun 2000 hingga 2017, menggunakan teknik Change Vector Analysis (CVA) dan menentukan threshold pada jenis LULC yang terjadi secara manual. Data yang digunakan adalah, Citra Landsat 5-TM dan Landsat 8-OLI TIRS, dan peta LULC di Kabupaten Bogor. Dari perubahan penggunaan/tutupan lahan dieroleh 36 jenis perubahan. Kelas penggunaan/tutupan lahan yang mengalami penambahan luas terbesar adalah tanah kosong/gundul. Kelas penggunaan/tutupan lahan yang mengalami penurunan luas paling besar adalah tegalan/ladang. CVA dapat mengidentifikasi LULC serta mampu menentukan besaran sekaligus arah perubahannya. Jenis perubahan dengan besaran besar perubahan tertinggi terjadi pada jenis LULC vegetasi non budidaya lainnya menjadi tegalan/ladang sebesar 0,33. Lahan yang tidak mengalami perubahan memiliki nilai besar besaran perubahan < 0,21. Arah perubahan yang terdeteksi adalah tidak berubah, vegetasi menjadi non vegetasi, non vegetasi menjadi vegetasi. Rentang nilai threshold tertinggi berdasarkan nilai magnitude terdapat pada jenis perubahan tegalan/ladang menjadi vegetasi non budidaya yaitu sebesar 0,31. Threshold berdasarkan kriteria direction lahan yang tidak berubah berada diantara 0,18 dan 0,22, lahan bervegetasi menjadi non vegetasi berada di antara 0,05 dan 0,23, dan non vegetasi menjadi bervegetasi berada diantara -0,05 dan 0,23., This study aims to determine the dynamics of Land use/Land cover change (LULC) in Bogor Regency, by identifying the magnitude, direction, pattern of LULC during the period 2000 to 2017, using the Change Vector Analysis (CVA) technique and determining thresholds on LULC types that occur manually, with Landsat 5-TM and 8-OLI TIRS image data, as well as, LULC maps. There were 36 types of LULC. The land use/land cover class that the largest area increase was wasteland. The land use/cover class that the largest decrease in area was moor. CVA can identify LULC and determine the magnitude of its directional changes The type of change with the highest magnitude of change occurred in the type of LULC of other vegetation to moor of 0,33. Land that does not change has a value of the magnitude of change < 0,21. The direction of change detected is unchanged, vegetation to non-vegetation, non vegetation to vegetation. The highest threshold value range based on the magnitude value is in the type of change from moor to other vegetation, which is 0,31. Threshold based on land direction criteria that does not change is between 0,18 and 0,22, vegetation to non-vegetation is between 0,05 and 0,23, and non-vegetation to vegetation is between -0,05 and 0,23.
Keyword: CVA, Perubahan penggunaan/tutupan lahan, Threshold, Vegetasi, Land use/cover change, Vegetation

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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