Judul: Adsorpsi biru metilena pada kaolin dan nanokomposit kaolin/TiO2 serta uji sifat fotokatalisis
Abstrak: Kaolin is rarely used as an adsorbent due to its small adsorption capacity. Therefore, kaolin was modified into a nanocomposite by physically mixing TiO2 powder with binder. Diffractometer X-ray characterization of Bangka Belitung kaolin (BNK) was done for comparison with Japan Clay Science Society (JCSS). The investigation showed the Bangka Belitung kaolin to have the same peaks as JCSS (2θ=12,36 and 24,88). Both kaolin and nanocomposite were tested for adsorption with methylene blue solution at concentrations of 25, 50, 75, 100, 150, 200, and 300 mg/L. Maximum adsorption capacity in both kaolins occurred at a concentration of 150 mg/L with a capacity of adsorption by Bangka Belitung kaolin of 28,93 mg/g, while that of the JCSS was lower (24,27 mg/g). The maximum concentration decreased for the nanocomposites as compared to the kaolin to 100 mg/L with the adsorption capacity for the BNK/TiO2 nanocomposite at 12,65 mg/g and JCSS/TiO2 nanocomposite at 8,58 mg/g. The photocatalytic properties of the nanocomposite was then tested using ultraviolet light (UV) at a wavelength of 254 nm. The test results with UV light showed that the nanocomposite could degrade methylene blue 12,5 mg/L, as indicated by the colorless filtrate and pale precipitate when compared with controls in the dark treatment. This result showed that nanocomposite can be used for adsorption-photodegradation of methylene blue.
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Judul: Nanokomposit kaolin-TiO2 dengan dopan urea untuk adsorpsi dan fotodegradasi zat warna biru metilena
Abstrak: Methylene blue is one type of dyes found as pollutant in Indonesia water system. Kaolin-TiO2 nanocomposite was synthesized and used to overcome this problem by utilizing its adsorption-photodegradation mechanism. Kaolin-TiO2 nanocomposite was made by mixing kaolin powder and TiO2 powder physically using ball milling and paste methods. The ball milling method is found to be simpler than paste method, and also resulting in smaller particle size. Smaller particle size also found to increase both adsorption and photodegradation activities. It is believed that ball milling method also generated a homogenous mixture. From 2 different sample compositions and 3 milling times used, it was found that synthesis kaolin-TiO2 nanocomposite requiring calciumbased binder with an optimum milling time of 5 hours. Kaolin-TiO2 nanocomposite was doped with urea by manual physical mixing followed by calsination at 300 °C for 2 hours. Urea doped-nanocomposite has larger activity than undoped nanocomposite in visible light zone. It means that the photocatalytic activity of urea doped-nanocomposite was successfully shifted to the red zone area of the visible light. Therefore, incident sunlight can be used as energy source in the adsorption-photodegradation process using nanocomposite Kaolin-TiO2.
Keyword: adsorption, ball milling, kaolin, methylene blue, photodegradation

Judul: Prolapsus vagina kronis, kausa dan teknik reposisinya
Abstrak: Prolapsus vagina kronis merupakan penyembulan bagian belakang hewan, khususnya lantai vagina melalui vulva, diikuti dengan perpindahan serviks dan uterus ke belakang. Pada sapi kejadian prolapsus vagina sering pada masa 2-3 bulan akhir kebuntingan, sedangkan pada domba dan hewan sejenisnya terjadi beberapa minggu sebelum melahirkan. Kasus prolapsus vagina kadang-kadang dapat terjadi setelah melahirkan, dan jarang terjadi tanpa ada hubungannya dengan kebuntingan atau kelahiran. Penyebab prolapsus vagina kronis belum dapat dipastikan, beberapa faktor umumnya ambil bagian. Faktor uta- ma adalah tingginya kadar hormon estrogen pada akhir kebuntingan. Faktor mekanis dengan meningkatnya tekanan intra abdominal dan gaya berat dari fetus dalam kandungan. Beberapa faktor predisposisi yang dapat menunjang terjadinya prolapsus vagina adalah: perlukaan saluran kelahiran, kelahiran yang rapat, makanan yang kurang baik, terbatasnya pergerakan, faktor lingkungan dan hereditas. Prolapsus vagina kronis umumnya hampir terjadi pada semua hewan piara, lebih sering pada sapi dan domba. Pada sapi sering terjadi pada sapi potong jenis Hereford ...
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