Judul: Sifat Anti Rayap Zat Ekstraktif Kulit Kayu Mindi (Melia azedarach Linn.) terhadap Rayap Tanah Coptotermes curvignathus Holmgren
Abstrak: Melia azedarach Linn. yang dikenal dengan nama mindi adalah pohon cepat tumbuh yang banyak ditanam saat ini untuk kebutuhan bahan baku industri kayu. Tujuan penelitian ini adalah memperoleh kadar zat ekstraktif kulit kayu mindi dan mengetahui sifat bioaktivitasnya terhadap rayap tanah Coptotermes curvignathus Holmgren serta mengidentifikasi kandungan senyawa bioaktifnya. Hasil penelitian menunjukkan bahwa kandungan zat ekstraktif kulit mindi sebesar 7.54%. Ekstrak asetonnya difraksinasi bertingkat dengan pelarut n-heksan, etil eter, dan etil asetat. Uji sifat anti rayap menunjukkan bahwa semua fraksi (n-heksan, etil eter, etil asetat, dan residu) memiliki sifat anti rayap dengan fraksi teraktifnya adalah fraksi etil asetat. Persentase mortalitas fraksi etil asetat ini mencapai 100% pada konsentrasi 6%, 8%, dan 10% serta kehilangan berat kertas uji terendah sebesar 6.3% pada konsentrasi 10%. Berdasarkan analisis Pyrolysis Gas Chromatography Mass Spectrometry (Pyr-GCMS) diketahui bahwa ada 6 komponen utama yang terdapat dalam fraksi etil asetat, yaitu pirokatekol, asam asetat, katekol, dioktil ftalat, asam palmitat, sitosterol, dan kelompok asam lainnya seperti asam karbonat, asam sinamat, dan asam miristat.
Keyword: Coptotermes curvignathus Holmgren, ekstraktif, Melia azedarach Linn., sifat anti rayap

Judul: Sifat Antirayap Zat Ekstraktif Daun Mindi (Melia azedarach Linn.) terhadap Rayap Tanah Coptotermes curvignathus Holmgren
Abstrak: Chinaberry, M. azedarach, is one of the species of Meliaceae family recognized having insecticide properties. The objective of this research was to determine extractive substances percentage of chinaberry, and to test the antitermite activities against subterranean termites C. curvignathus Holmgren, as well as to analyze chemical substances extract quantitatively through Pyr-GC-MS. The extraction of chinaberry leaves used multilevel fractionation method where in there are four types of fractions obtained, namely n-hexane, ethyl ether, ethyl acetate, and the residue. Each fraction was made at concentration of 2%, 4%, 6%, 8%, and 10% for the termites test. The result showed the percentage of chinaberry leaves extractives was 10.53%. Ethyl ether fraction had the highest termite activity at all concentrations based on mortality and weight loss. At concentration of 8% and 10%, ethyl ether fraction resulted in mortality of up to 100% with a weight loss of 0.63% and 5.37%. Based on the analysis of GC-MS pyrolysis, leaves extract which was soluble in ethyl ether contained five compounds with the highest concentration, namely cinnamic acid, benzoic acid, benzenepropanoic acid, palmitic acid, and phytol
Keyword: extractives substances, Coptotermes curvignathus, chinaberry leaves, antitermite

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model