Judul: Pemanfaatan Karet Alam Sebagai Aditif Pada Mortar Untuk Meningkatkan Mutu Jalan Semen Beton
Abstrak: Nowadays, natural rubber consumption in Indonesia is relatively low. By diversification of natural rubber uses as additional mixture for concrete road is expected to increase its consumption. At this time, concrete road doesn’t use latex, so it will less flexible and susceptible to crack. Also this matter can’t make concrete road comfortable to use. Therefore, with admixture of latex to the cement may be able to increase flexural strength. The objectives of this research were to know type and dose of stabilizing agent for suitable admixture of latex and cement, and to know the effect of type of latex and rubber dose as additional mixture for mortar. This research consisted of two steps. First step was preliminary research which used type (Emal, Emulgen and Casein) and dose (1, 3, 5 and 7%) of stabilizing agents to determine a suitable admixture of latex and cement. Second step was main research where the effects of latex on mortar was determined. Types of latex tried were Centrifuge Latex (LP), Double Centrifuge Latex (LDS) and Deproteinized Natural Rubber Latex (LDPNR). Rubber doses of 0 (control), 1, 3, 5, 7 and 9 were used. When latex was mixed with cement, it agglomerated. Therefore, suitable type and dose of stabilizing agent was needed. The best stabilizing agent was Casein of 7% because it could maintain the setting time to almost 210 minutes. This combination was used in main research. The highest initial weight was obtained from LDS, i.e. 261.25 g, whereas final weight, i.e. 266.70 g. Rubber dose of 1% gave the highest initial weight, i.e. 268.70 g and final weight, i.e. 272.83 g. Final weight would be heavier than initial weight. The more rubber dose used in mixture mortar, the less weight of mortar produced. Mortar added by latex showed lighter weight than its control. LDS gave a significant effect on mortar’s compressive strength, whereas LDPNR didn’t have significant effect. LDS gave the highest compressive strength, i.e. 176.60 kg/cm2. Rubber dose of 1% gave the highest compressive strength, i.e. 200.67 kg/cm2. The more rubber dose used, the less compressive strength of mortar produced. LDS gave highest flexural strength than LP and LDPNR, i.e. 33.62 kg/cm2. Rubber dose of 1%, i.e. 36.77 kg/cm2 gave the highest flexural strength. LDS dose of 7% gave the highest flexural strength, but its compressive strength was low. Therefore, to produce strong and flexible mortar could be used LDS with dose of 1%.
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Judul: Pemanfaatan Lateks Karet Alam Sebagai Bahan Pemodifikasi Aspal Untuk Meningkatkan Mutu Perkerasan Jalan Aspal.
Abstrak: Indonesia is the second largest producer of natural rubber in the world after Thailand. Indonesia's natural rubber production in 2007 reached 2.55 million tons per year. However, Indonesia's natural rubber production has decreased due to the global crisis that occurred in 2008. One of the sectors directly affected by the crisis is the automotive industry which is the largest consumer of natural rubber in the world. On the other hand, economic growth will increase the traffic load in terms of quantity, weight and speed. The burden of heavy traffic, road surface temperature reaches 70oC, high rainfall and the poor drainage, causing the road can be easily damaged. Therefore, paving way’s modification is required to fulfill those needs, one with the latex modified asphalt. The purposes of this study were to determine the effect of types and additional doses of latex in the asphalt toward penetration value and softening point which affecting the quality of asphalt pavement and to get the best mixture of asphalt to improve the quality of asphalt road pavement. This research methodology consiststed of two stages, namely preparation of raw materials (determination of the nature and characteristics of latex and latex depolymerization process) and the main research (the mixing process of latex into the asphalt and testing). Experimental design used in this study was Complete Random Factorial design with two replications for each treatment. Factors that influence were types and additional doses of latex rubber in the asphalt with each level of 8 and 3. There were two types of latex used in this study, namely concentrated latex which have dry rubber content (DRC) and depolimerization latex (latex which has decreased due to the molecular weight of polymer bonds break). Depolimerization latex in this study employed chemical methods with reduction-oxidation reaction (redox) with hydrogen peroxide (H2O2) as an oxidant and sodium hypochlorite (NaClO) as a reductant. In general, asphalt modification which has produced fulfill the quality requirements or quality standards for asphalt polymer at the value of penetration and softening point. Quality standard of penetration value is 50-75 dmm, whereas minimum value for softening point is 54oC. Modification of asphalt penetration values ranged from 49.33 to 61.25 dmm. There are two types of asphalt modifications outside the standard value, namely the modification of asphalt with a penetration of 49.52 and 49.33. Softening point value of asphalt modification ranged from 56.11oC to 65.27oC. The best asphalt modification was L5K5 sample (depolimerization latex with 5% additional doses of rubber in asphalt). Selection of the best asphalt modification was not only determined by the suitability of the penetration value and softening point with quality standard, but also was determined by homogenity between the asphalt dan rubber.
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Judul: Theileriosis pada domba dan kambing akibat infeksi theileria ovis dan theileria hirci
Abstrak: Theileriosis adalah penyakit menular yang disebabkan Boleh protozoa dari genus Theileria dan ditularkan melalui vektor caplak. Theileria ovis dan Theileria hirci pernah dimasukkan dalam genus Gonderia sehingga penyakit yang disebabkan oleh penyakit ini mempunyai beberapa nama diantaranya Benign Ovine and Caprine Gonderiosis atau Benign Ovine and Caprine Theileriosis (disebabkan oleh infeksi Theile- ria ovis). Sedang yang disebabkan oleh infeksi Theileria hirci diberi nama Malignant Ovine and Caprine Gonderiosis Malignant Ovine and Caprine Theileriosis (Levine, 1961). Soulsby (1982) dan Jensen (1983), memasukkan Theileria hirci dan Theileria ovis dalam genus Theileria, famili Theileriidae, ordo Piroplasmida, subklas Piroplasmia dan dalam kelas Sporozoa. Menurut hasil pemeriksaan theileriosis pada domba dan kambing di Indonesia periode 1 April 1981 sampai 31 Maret 1982 di Propinsi Sumatera Barat di Daerah Tingkat II Pasaman Kecamatan Talamun ditemukan pada 2 ekor kambing kacang, Kecamatan Sungai Beremas ditemukan pada 3 ekor kambing kacang dan di Daerah Tingkat II Padang Pariaman, Kecamatan Pariaman ditemukan pada 1 ekor kambing kacang (Informasi Keswan, 1982). Daerah penyebaran Theileria ovis yang pernah dilapor- kan adalah Afrika Tengah, Afrika Barat, Afrika Timur, Afrika Selatan, Perancis, Jerman, Hongaria, Sardinia dan diduga India. Sedangkan penyebaran Theileria hirci meli- puti Afrika Utara, Eropa Selatan, Irak dan Turki. Bentuk Theileria ovis dan Theileria hirci pada domba dan kambing dalam eritrosit disebut piroplasma dan bentuk dalam limfosit disebut Koch bodies atau skizon. Bentuk dalam vektor caplak adalah zigot dan kinet. Di dalam eritrosit parasit ini mempunyai beberapa macam bentuk yaitu, bentuk bulat, oval, batang, bentuk buah pir atau koma dan bentuk seperti anaplasma. Bentuk dalam limfosit berupa skizon yang terdiri dari makroskizon dan mikroskizon. Penularan Theileria ovis dan Theileria hirci dari hewan satu ke hewan lain secara alam dilakukan oleh vektor caplak secara stage to stage. Vektor dari Theileria ovis adalah caplak dari genus Rhipicephalus, Dermacentor, Hae- mophysalis dan Ornithodorus. Sedangkan vektor dari Thei- leria hirci yaitu caplak dari genus Rhipicephalus dan di- duga Ornithodorus. Penularan secara buatan dapat dilakukan dengan cara mekanik (penyuntikan dengan aplikasi intravena, subkutan dan intraperitoneal)…dst
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