Judul: Chemical Induction of Prunus Cerasoides D. Don Gum  using Methyl Jasmonate and Etefon
Abstrak: Gum dan saluran gum merupakan sifat anatomi yang umum dijumpai pada pohon daun lebar dan juga dapat terbentuk akibat diinduksi oleh stimulus eksternal. Pada penelitian ini, induksi kimia dilakukan untuk menstimulasi produksi gum Prunus cerasoides D. Don oleh metil jasmonat dan etefon dengan berbagai variasi konsentrasi, yakni 0.1%, 1%, 2%, 5%, dan 10% (b/b), dan lanolin murni sebagai kontrolnya. Perlakuan induksi dengan hormon eksogen ini dilakukan sebanyak 5 kali pengulangan. Setelah 21 hari pemberian penginduksi, gum tereksudasi akibat perlakuan metil jasmonat semua konsentrasi, kecuali konsentrasi 5% (b/b). Berbeda hal dengan induksi etefon, gum tereksudasi pada konsentrasi 2%, 5%, dan 10% (b/b). Eksudat gum yang dihasilkan kemudian dilakukan analisis sifat fisik dan analisis komposisi senyawa kimia dengan LC-MS/MS dan FTIR. Saluran gum terbentuk pada lingkar kambium karena adanya perlakuan kimiawi. Ukuran saluran gum terbesar terbentuk pada konsentrasi metil jasmonat 10% (b/b) yakni 38.386 µm. Hasil pengujian gum dengan LC-MS/MS menunjukan gum dari P. cerasoides mengandung 28 jenis senyawa kimia, dengan 5 senyawa berkonsentrasi tertinggi dari kelompok sukrosa (lauril sukrosa), ester, asam karboksilat, triterpenoid, dan peptida. Hasil ini didukung oleh spektrum FTIR yang mengkonfirmasi keberadaan polisakarida dalam gum eksudat, yaitu ditunjukkan dengan adanya daerah fingerprint pada 800–1200 cm-1 . Lebih lanjut lagi, gum eksudat diduga mengandung protein yang ditunjukkan oleh pita lebar ⎯NH, Amida A dan Amida I pada puncak serapan 3395.381 cm-1 dan 1618.18 cm-1 . Kata kunci: etefon, gum, metil jasmonat, polisakarida, Prunus cerasoides., Gum and gum ducts are important anatomical traits usually present in broad-leaved trees, and are also induced by external stimuli. In this research, the chemical induction to stimulate the production of Prunus cerasoides D. Don gum was conducted using methyl jasmonate and ethephon with various concentrations of 0.1%, 1%, 2%, 5%, and 10% (w/w). After 21 days of treatment, methyl jasmonate induced the gum exudation at all of concentration, except 5% (w/w). In other hand, ethephon induced the gum exudation at the concentration of 2%, 5%, and 10% (w/w). The exudate gum was physically analyzed and then subjected to LC-MS/MS and FTIR analysis. The treated shoots were then analyzed histometrically through the standard procedure. The gum ducts were developed in the cambium circumference after the chemical treatments. The largest gum duct diameter was observed at about 38.386 µm after 10% (w/w) methyl jasmonate treatment. The analysis of the gum by LC-MS/MS indicated the presence of sugars (e.g lauryl sucrose), carboxylic acid,ester, triterpenoid, and peptide analog. Furthermore, the spectrum resulting from FTIR investigation demonstrated that the exudate gum was mainly composed of polysaccharides, as indicated by the fingerprint region of 800-1200 cm-1 . In addition, the gum was assumed to contain protein, ⎯NH, its peak at 3100-3500 cm-1 and 1600 cm-1 . Key words: ethephon, gum, methyl jasmonat, polysaccharides, Prunus cerasoides
Keyword: ethephon, gum, methyl jasmonat, polysaccharides, Prunus cerasoides

Judul: Kajian Pemanfaatan Getah Pinus (Pinus merkusii) Sebagai Bahan Baku Perekat
Abstrak: Pine merkusii included to multipurpose tree species that developed and expanded continually to produce timber, gums, and as conservation land. Almost all parts of the tree can be utilized. Part of the tree that has high values is the pine gum. Processing of pine resin is widely used in printing ink industry, coating industry, and adhesive industry. Adhesive substance is a material that can be joined with the same or different type of object through bonding process or surface contact, so the body of joint object is resist to separation effort. In the production of pine gum adhesive substance, esterification process carried out to improve the adhesive power. This research aims to study the process of making adhesive substance from pine gum esters, and also to determine the effect of acid number, ester number, glycerol number and catalyst concentration on adhesive strength of the adhesive products. Stages of this research is the characterization of pine gum raw materials; esterification using KOH catalyst with concentration 1.5 and 10% by weight of pine gum, and moles of glycerol 1.1, 1.5, and 2 mol; making of the adhesive substance and determination of the best adhesive substance based on its best adhesive strength. Conducted preliminary research is the characterization of raw materials of pine gum, and then continued with the main research that is esterification of pine gum using alkaline catalyst (KOH), and making of the adhesive substance of the pine gum esterification. The treatment that used is the concentration of KOH catalyst (1%, 5%, and 10%) and the mole of glycerol (1.1 mol, 1.5 mol, and 2 mol). The esterification results of the pine gum tested through acids numbers, esters numbers, and free glycerol levels by comparing between the unwashed pine gum esters and the washed. The esterification results are made into adhesive substance. Then the surface area of adhesive strength and the adhesive strength of adhesive substance tested with shear stress (shear strength) of the adhesive strength and test. Based on preliminary research results, the characteristics of pine gum that was obtained is a liquid, slightly yellow color, soluble in ethanol solvent ratio of 90 percent with 1 ml of pine resin:1 ml of ethanol, acid number 125.66, and viscosity Cp 8693.14. The results of measurements showed that the adhesive substance with the code C22 (with KOH catalyst 5%, 1.5 mol glycerol, washed) gives a better adhesive strength. The characteristics of adhesive substance with the code C22 are: acids numbers 109.21 and esters numbers 21:18. Based on the observations, it can be concluded that the adhesive substance that was processed with 5% catalyst and 1.5 mole of glycerol with the code C22 is the best adhesive substance compared with others based on its adhesive strength.
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Judul: Uji Robust T2-Hotelling dengan Menggunakan Penduga Minimum Covariance Determinant
Abstrak: Hotelling’s T2 statistic is a good statistic for inference about the mean of a multivariate normal population. In Hotelling’s T2 statistic, approximation with Bonferroni confidence intervals provides shorter interval than T2 confidence intervals. Therefore, to find the mean of a multivariate normal population, simultaneous t-intervals based on the Bonferroni method is often applied. However, hypothesis test and confidence intervals based on T2 statistic can be significantly affected by outliers in a set of multivariate normal data. Therefore, to find a good estimator for the mean of a multivariate normal population, the Minimum Covariance Determinant (MCD) estimator is used. To increase the efficiency of the MCD estimator, this test statistic is applied using the reweighted MCD which gives weights to the mean and covariance based on the robust of the observations.
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