Judul: Diafragma Sensor Akustik Serat Optik Berbasis Komposit Chitosan-Polivinil Alkohol
Abstrak: Diafragma dengan material komposit chitosan merupakan inspirasi baru dalam pengembangan sensor akustik serat optik. Karakteristik unik yang dimiliki film berbasis komposit chitosan, seperti modulus elastisitas, respon dinamik dan sensitivitas terhadap gelombang akustik merupakan potensi besar material sensor akustik serat optik berbasis bahan organik. Tujuan penelitian ini adalah mengembangkan diafragma dengan material komposit chitosan dan polivinil alkohol untuk aplikasi pada sensor akustik serat optik. Formulasi komposisi larutan material dasar meliputi masing-masing larutan PVA 5% dengan chitosan konsentrasi 0%, 1%, dan 2% proporsi 1:1. Pengujian yang dilakukan untuk memprediksi sensitivitas sensor akustik serat optik, meliputi karakterisasi morfologi dan mekanik diafragma. Performa optimum diperoleh pada komposit dengan chitosan 2%, dengan ketebalan 242,55 μm, kelembapan relatif 67,9%, serta dapat mentransmisikan cahaya sebanyak 29-76%. Diafragma komposit dengan konsentrasi chitosan 2% memiliki modulus Young 4,89×104 N/m2, respon dinamik terhadap gelombang akustik dengan amplitudo 0,013 V, serta sensitivitas sebesar 3,28 mV/Pa pada frekuensi 1 kHz.
Keyword: chitosan, diafragma, komposit, sensor akustik, serat optik

Judul: Material Medis Penambal Membran Timpani Berbasis Komposit Chitosan Melalui Pendekatan Mekanoakustik
Abstrak: Perforation patch scaffold organic model-based on chitosan through mechano-acoustical approach to assess the perforation enclosure quality in terms of sound pressure quantity is the new inspiration of perforation closure method. The objectives of this research was to develop a model of composite chitosan as medical patch material of tympanic membrane through mechanoacoustical approach. Chitosan composite membrane formulated with polyvinyl alcohol (PVA) only (A00), 3% chitosan-3% glycerol (B33), and 5% chitosan-1% glycerol (C51). Optimum formulation is obtained on a composite chitosan, glycerol, and PVA with 3%/4%/5% ratio (B33) had characteristics of 622,29 kg/m3 in density, 160,70 μm in thickness, 1.43×10-2 g/mm a day in water vapour transmission rate. Its formed varied pores, granule, and hygroscopic condition on composite membrane due to the addition of chitosan and glycerol on varied ratio. Mechanoacoustical test results of composite membranes with the formula had 0,30×106.N/m2 in Young's modulus; 0,18 cm-1 in sound absorption coefficient; 0,22×102 m/s in velocity on medium; 203,52 dBSPL in membrane sensitivity; and 94% of sound attenuation rate.
Keyword: tympanic membrane perforation., mechanoacoustical, composite, chitosan

Judul: Infection Of Babesia Bigemina In Cattle And Methods Of Control
Abstrak: Babesia bigemina is the species which occurs mostly through out the tropics and subtropical areas. It gains access to the susceptible cattle through the bite of an· ig fected tick and penetrates an erythrocyte. The pathogenesis of B. bigemina is considered to be as highly pathogenic and may cause heavy mortality in susceptible stock. Infecied cattle rapidly become dull and listless and lose their appetite, the erythrocytes are destroyed resulting anaemia, icterus, emaciation, weakness, and a drop in milk production. Death and loss of productivity due to B. bigemina account for the economic loss.
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