Judul: Failure Analysis On Corrosion of Al-Zn Heat Reflector in Timber Dry Kiln
Abstrak: Al-Zn alloy coated steel sheet (JIS G3 141) was used as a heat reflector in timber dry kiln. After six months continuous service at 110 derajat celcius in moist condition, the heat reflector is corroded. Failure analysis method was used to analyze this corrosion phenomena. Macroscopic and microscopic examination with some characterizations have been performed to determine the elemental composition and corrosion products. The elemental composition of corroded heat reflector that were detected by SEM-EDS are sulphur, chloride, calcium, sodium and potassium. XRD analysis revealed the zinc aluminum carbonate hydroxide hydrate (Zn6Al2(OH)16CO3.4H2O) black rust staining and iron oxide (FeFe204), as corrosion product. Environmental condition in timber dry kiln with the existence of acid and alkaline elements make the corrosion process occur. Those elements came from the dried timber and steam that adhered on the heat reflector surface and they attacked the Al-Zn coating and base metal. The humidity and high temperature in timber dry kiln environment are factors that increase the corrosion rate of the heat reflector.
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Judul: Pengaruh Jenis Alkohol pada Rendemen Sintesis Zink Dialkilditiofosfat
Abstrak: Zinc dialkyldithiophosphate (ZDTP) is an organometallic compound used as an additive in lubrication system. ZDTP was composed of Zn atoms with two dialkyldithiophosphoric acid. The usefulness of ZDTP depends on alkyl content, as for antiwear, antioxidant, anticorrosive, and restrain extreme pressure. ZDTP can be synthesized through two step. Firstly, dialkyldithiophosphoric acid (ADTP) was made from diphosphorus pentasulphide (P2S5) with alcohol. Second, ADTP was reacted with zinc oxide (ZnO), producing ZDTP. The suitability of the ZDTP has been varied by using fourier transform infrared spectrophotometer (FTIR), atomic absorption spectrophotometer (AAS), and high performance liquid chromatography (HPLC). The yield of ZDTP 1-4 were 13.88%, 43.50%, 97.29%, and 77.35%, respectively. The result of FTIR characterization in ZDTP showed P-O-C group absorption at 1000􀵆980 cm-1, PS bond absorption at 650􀵆550 cm-1, and Zn-S bond absorption at 400􀵆300 cm-1 . AAS was used to determine the content of Zn in ZDTP 1-4 with the value of 16.16%, 28.82%, 11.81%, and 17.36%, respectively. Verification of compliance indicators ZDTP were measured by comparing the retention time and HPLC chromatograms. It showed that the measured ZDTP had similar retention time with and authentic commercial ZDTP on the same absorption band despite, low concentrations.
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Judul: Inseminasi buatan pada primata non manusia
Abstrak: Inseminasi buatan pada primata merupakan salah satu cara untuk meningkatkan populasi primata, agar hewan tersebut dapat dicegah kepunahannya, selain itu untuk kepen- tingan biomedis pada kedokteran manusia. Pubertas pada monyet betina terjadi kira-kira pada umur 2 sampai 4 tahun, sedangkan pada kera kira-kira pada umur 2 sampai 8 tahun. Menstruasi pertama terjadi pada umur 2,5 sampai 4 tahun pada monyet dan 9 tahun pada kera. Lamanya siklus menstruasi berkisar antara 28 sampai 35 hari dengan waktu ovulasinya terjadi kira-kira pada per- tengahan siklus menstruasi yaitu antara hari ke 11 sampai ke 15, pada saat inilah waktu yang tepat untuk melakukan. inseminasi buatan. Tehnik yang paling efisien dalam pengumpulan semen adalah dengan cara elektroejakulator, sedangkan metode. inseminasi dapat dilakukan secara intravaginal, intrasertival, intrauterin dan intraperitoneal. Inseminasi buatan dengan semen beku sudah berkembang di negara-negara maju, karena semen monyet yang kaya akan sperma dapat diencerkan dan dibekukan secara bertahap.
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