Judul: Membran Komposit Kitosan-Nanopartikel Magnetik Fe3O4-Hidroksiapatit untuk Rekayasa Jaringan Tulang.
Abstrak: Composite membrane implants from biodegradable and biocompatible polymers such as chitosan, added with Fe3O4 magnetic nanoparticleshydroxyapatite (MHAP) is an alternative that is appropriate for bone tissue engineering. The MHAP was first synthesized using coprecipitation method with 3 different composition, with the ratio of Fe3O4 : hydroxyapatite is 3:7, 4:6, and 5:5 by mass. The composite membrane chitosan-MHAP (MK K-MHAP) was then synthesized by mixing a chitosan solution and the best MHAP composition (10, 20, 30, and 40% w/w of the mass of chitosan). Characterization using X-ray diffraction confirmed the formation of Fe3O4 and hydroxyapatite phase on the MHAP. The magnetic saturation value and size of Fe3O4 magnetic nanoparticles increase with the increasing Fe3O4 composition in MHAP and MK K-MHAP which characterized based on its magnetic hysteresis and particle size distribution curve, respectively. The morphology of the best composition of MHAP composite was analysed using transmission electron microscope. Molecular interactions in MK K-MHAP was characterized based on infrared spectra. Immersion test of MK K-MHAP showed optimum state at 30% mass MHAP composition in chitosan matrix with calcium concentration released about 1000 ppm within 144 hours.
Keyword: biomedical, chitosan, composite membrane, hydroxyapatite, magnetite

Judul: Sintesis Komposit Hidroksiapatit dengan Variasi 10-50% Kitosan
Abstrak: In medical cases, HAp/chitosan composite can be used as a synthetic implantation in bone. Addition of chitosan on HAp seems produce good composite. Chitosan can reduce the properties of brittle HAp. XRD characterization on all samples showed that pattern has formed apatite dominated by the peak of HAp. The peak of chitosan on the results of XRD was not visible. It is due to chitosan has spread all over the samples. On FTIR characterization, the appearance of phosphate group and hydroxyl group show that HAp was identified in samples, while chitosan was indicated by the appearance of a group of NH, CO and CH. The results of observations with an optic stereo microscope, samples morphology showed that HAp was well distributed in chitosan. Test results of shore A test showed the addition of chitosan on HAp proved able to eliminate brittle properties of HAp. A lot of chitosan in the samples will reduce the hardness of the composition of the HAp / chitosan
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Judul: Analisis pendapatan pedagang sayur keliling di kelurahan tegallega kota Bogor
Abstrak: Perdagangan kecil terdiri dari pedagang yang membuka tempat berjualan sederhana yang didatangi oleh konsumen atau pedagang keliling yang mendatangi konsumennya. Salah satu dari pedagang keliling yaitu pedagang sayur keliling. Pedagang sayur keliling adalah pedagang yang produknya berupa berbagai jenis sayuran yang dibawa kerumahrumah guna memenuhi kebutuhan konsumen. Kecamatan Bogor Tengah merupakan salah satu kawasan dengan penduduk terpadat di Kota Bogor. Hal ini menjadikan kecamatan Bogor Tengah sebagai salah satu sentra pedagang sayur keliling di Kota Bogor. Pedagang sayur keliling di Kelurahan Tegallega mendatangi konsumennya pada pagi sampai siang hari. Tidak jarang beberapa pedagang datang pada waktu yang sama dengan pedagang lainnya sehingga konsumen bebas memilih produk yang mereka butuhkan dari beberapa pedagang sekaligus. Produk yang ditawarkan oleh pedagang sayur keliling sesuai dengan kebutuhan konsumen dan harga yang dibeli juga tidak jauh berbeda dengan di pasar.
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