Judul: Perubahan Kontraksi Otot Longitudinal  Usus Halus Kelinci Akibat Paparan  Medan Listrik Dan Magnet Secara In Vitro
Abstrak: Effects of electric and magnetic field on living tissue have drawn scientist’s attention because of it’s widespreads use on many major of life. In this experiment, static electric field 7,5, 15, 22,5, 30, 37,5, and 45 V/m and magnetic field strength from 30, 60, 90, 120, 150, and 180 Gauss were used to investigate contraction alteration on longitudinal smooth muscle contraction of rabbit small intestine. Electric field did not affect alteration of amplitude and contraction’s frequency on duodenum, jejenum, and ileum. Magnetic field exposure on duodenum and ileum had amplitude alteration pattern that increased in field power of 30 Gauss. This pattern is suspected related with hormesis phenomena. Duodenum amplitude’s alterations was not significant, jejenum amplitudes significantly decreased on 90 Gauss, while ileum amplitude significantly differed with control on 90, 120, and 180 Gauss, but magnetic field did not affect contraction’s frequency. Small intestine contract autonomically. Electric and magnetic fields are suspected influence ion transportation for contraction of small intestine such as Ca2+, Na+, K+ , ion channnel and neurotransmitter of intrinsic plexus that play a role in controlling smooth muscle contraction.
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Judul: Respon Otot Polos Ileum Kelinci Lokal Terhadap Medan Magnet 60 dan 420 Gauss Secara In Vitro dengan Variasi Suhu Tyrode
Abstrak: The digestive system in the living body involving the small intestinal organs, which included Na+, K+, and Ca2+ channels which play an important role in smooth muscle contraction. Observations on smooth muscle contraction performed on isolated ileum of rabbits that had just died and placed in a organbath that has been filled with tyrode 37 °C. Amplitude, frequency, and strength of contractions were measured using the Force Sensor Data Acquisition System with the application of ADInstruments Australia. Magnetic field of 60 and 420 Gauss can increase the amplitude and force of contraction, and reduce the frequency of contractions. Increasing magnetic field will decrease the contraction of smooth muscle in the body due to the weakening of ions performance in the body. However, when the temperature of tyrode is decreased from 20 to 40 °C the amplitude and force of contraction are increased. The frequency of contractions tend to be constant at any temperature, except for 20 °C where the frequency of contractions is very different compared to other temperatures. If the temperature is too low the contraction of ileum is not stable or even non-exist, which probably indicates the dead of the intestine.
Keyword: temperature, smooth muscle, the magnetic field

Judul: Katalis Eterifikasi Gliserol Berbasis Poli–(asam stirena sulfonat) dari Limbah Styrofoam.
Abstrak: Styrofoam waste can be converted to poly–(sulfonate styrene acid) (PSSA) that can be used as catalyst. The objective of this research is to get PSSA that can catalyze the etherification of glycerol and benzyl alcohol. The styrofoam waste was converted to PSSA by reacting with H2SO4 98% (as sulfonation agent) and P2O5 (as sulfonation catalyst) at 40 °C for 6 hours. Characterizations of PSSA included functional groups, sulfonation levels, water swelling, and thermal stability. The yield of PSSA was 40-55%. The success of sulfonated polystyrene was shown by –SO3H group absorption at 1157.29 cm-1. Etherification of glycerol and benzyl alcohol using PSSA catalyst was conducted at 110 °C for 12 hours. The conversion in producing mono–benzyl ether glycerol was 8.10%, 1,3–dibenzyletherglycerol 2.60%, and dibenzyl ether 9.80%. Therefore, the PSSA can be used as etherification catalyst.
Keyword: benzyl alcohol, etherification, glycerol, polystyrene, PSSA