Judul: Karakteristik Kulit Kaki Ayam yang Disamak dengan Krom dan Mimosa serta Ekstrak Kulit Buah Salak (Salacca Edulis Reinw)
Abstrak: Leather tanning is a process to transform the unstable raw skin into more stable form. The aim of this research was to determine characteristics of chicken foot’s skin which tanned using mineral (chromium) and vegetable tanning material (mimosa and salak peel’s extract). This research used chicken foot’s skin tanned with one control and 3 treatments. Each treatment used similar materials, namely; chromium, mimosa and salak peel’s extract, with different concentration. Control treatment consisted of 100% chromium; treatment 1 consisted of tanning material with ratio of 70:20:10; treatment 2 with ratio of 60:20:20 and treatment 3 with ratio of 50:20:30. Each treatment had 3 replications. The observed variables were tensile strength, elongation and tear endurance. Data were analyzed by using analysis of variance. The results showed that tensile strength, elongation and tear endurance of chicken foot’s skin tanned with each treatment showed not significant different (P> 0.05) with the best treatment ratio was 50:20:30.
Keyword: tanning, salak peel, chicken claw’s skin, Bogor Agricultural University (IPB)

Judul: Karakteristik Kulit Ceker Ayam yang Disamak dengan Kombinasi Krom dan Mimosa serta Ekstrak Daun Jambu Biji (Psidium guajava Linn.)
Abstrak: Tanning is the process of converting protein rawhide into leather which stable and not easily decompose. Tanning can be performed on the skin of chicken claw because it has a protein content that is not different from the protein skin of cattle about 23%. The use of chromium can be overcome with vegetable tanning materials that derived from plants and environmentally friendly. The purpose of this study was to determine the characteristics of the tanned skin of chicken claw with a combination of chrome, mimosa and guava leaf extract. Observed variables consisted of tensile strength, elongation, and tear endurance with repetition performed 3 times. The results showed that the concentration of guava leaf extract different effect on tensile strength, but has no effect on elongation and tear endurance of leather. Chrome and mimosa still give effect to the tanning process, but the addition of guava leaf extract as much as 10% showed optimum ability to help increase the tensile endurance of leather.
Keyword: tanning, Bogor Agricultural University (IPB), guava leaf, chicken claw

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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