Judul: Demografi Kumbang Penyerbuk Kelapa Sawit, Elaeidobius kamerunicus (Coleoptera : Curculionidae)
Abstrak: Oil palm is a specific host plant for the weevil E. kamerunicus. These weevils can only eat, lay eggs, and breed in oil palm male flowers. This study aimed to study demographics of E. kamerunicus as oil palm pollinators, such as biology, life table, and the survivorship. A pair of E. kamerunicus were reared in the box contained male flowers spikelet. At the base of spikelet were immersed by water at film bottle. Body and sex ratio were observed during development of egg to adult. Demographic study were analyzed based on gross reproductive rate (G), net reproductive rate (R0), generation time (T), and intrinsic growth rate (r). In average life cycle of E. kamerunicus was 33 days i.e. 2.5 days of egg, 12 days of larvae, 5 days of pupae, and 15 days of male and 18 day of female adult, respectively. Demography of the weevil were: gross reproductive rate was 6 individuals, net reproductive rate was 3 individuals, generation time was 15 days, and intrinsic growth rate was 0.06. In a life cycle, fecundity of E. kamerunicus was 27 eggs and mortality from egg to adult was 72.9%. Based on the survivorship curve, mortality in early phase was constant and increase at adult phase.
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Judul: Demografi dan Perbanyakan Kumbang Elaeidobius kamerunicus sebagai Penyerbuk Kelapa Sawit Elaeis guineensis Jacq
Abstrak: The aim of the research were to study demography and rearing of E. kamerunicus in oil palm (E. guineensis Jacq) male flower. Each phase in life cycle i.e egg, larva, pupa, and imago were observed. The life table and statistic demography were constructed base on the life cycle data. The result showed that the life cycle of E. kamerunicus was 34 days, the egg, pupa, and imago development time were 3, 10, 3, and 18 days, respectively. Demography of E. kamerunicus obtained were: gross rate of reproduction (G) was 7 female/cohort, the net of reproduction (R0) was 3,82 female/cohort, the generation time (T) was 18 days, the intrinsic rate of population was (r) 0.074, and the sex ratio of male and female was 5:7. From age phase observed result that the highest death proportion was in larva period. From the observation of E. kamerunicus egg laying distribution, weevils prefered 1-3 cm from the terminal part to lay eggs. Rearing of the weevils can produce progeny 15,55 individual and male/female sex ratio was 4:3. Good and fresh of male flower can affect the number of living imago.
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Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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