Judul: Formulasi Surfaktan Metil Ester Sulfonat sebagai Oil Well Cleaning
Abstrak: Oil productivity reduction may be due to plugging in the oil rock formations. The plugging may be caused by the deposition of paraffin, asphaltene, and scale. Problem caused by the presence of the precipitate is the rock formation can be oil wet so that oil permeability decreases. The problem can be solved by well cleaning technique with surfactant formula. Surfactant MES is a type of anionic surfactant which has ability to lower the interfcial tension, surface tension, and able to change the properties of rock from oil wet to become water wet. Surfactant MES formula for well cleaning requires carrier agent. In this study, diesel oil and metil ester were used as carrying agent. Aromatic solvents were also needed. Xylene and toluene has ability to dissolve asphaltene that deposites in formation. Surfaktan formulation for well cleaning was done with several stages, those are determine the SMES concentration and aromatic solvents concentration. Surfactant performance tests for oil well cleaning were thermal stability, phase behavior, and wettability. The surfactant formula which gave the best performance was SMES 3% in metil ester carrying agent with xylene 15% as additive.
Keyword: methyl sulfonic esters, oil well cleaning, Asphaltene

Judul: Formulasi Surfaktan SMES sebagai Acid Stimulation Agent untuk Aplikasi di Lapangan Karbonat OK
Abstrak: Methyl Sulfonic Esters (MES) is one type of anionic surfactants which have advantages in terms of its hardness, resistance to deterjensi, the character of renewable and environmentally friendly. Excess MES this can be utilized as stimulation agent in oil wells, so can increase productivity an oil well. Increased productivity an oil well done by means of cleaning oil wells and pore a reservoir fromsediment of scale formed, enlarging the pores of rocks and can changing the nature of rocks being water-wet. This research was carried out to obtain the formula of solution of surfactants-based MES that can be applied as acid stimulation agent that is one method of IOR. Formula tested is a combination of surfactants sodium MES, HCl, and CH3COOH. The formulation is done by determining the optimum concentration of surfactant SMES and HCl gradually. The best results obtained from the solution of acid stimulation agent was with value of IFT < 10-2 dyne/cm with solubility of rock reaches 36%, and was can to change the contact angle of the reservoir rocks of the contact angle number 420 became 680 in formula SMES 6% + HCl 7% and CH3COOH 2%.
Keyword: acid well stimulation, IOR, IFT, Sodium Methyl Sulfonic Esters

Judul: Pengukuran Jantung Kelinci New Zealand White (Oryctolagus cuniculus) dengan Radiografi Toraks
Abstrak: This research was conducted to evaluate radiographs heart size of anaesthetized New Zealand White rabbits (Oryctolagus cuniculus) under different combination of ketamine and xylazine. The rabbits were divided into three groups. Group A were anaesthetized using a 35 mg/kg and 5 mg/kg combination of ketamine and xylazine (n=5). Group B were anaesthetized using a 40 mg/kg and 5 mg/kg combination of ketamine and xylazine (n=3) while group C were anaesthetized using 45 mg/kg and 5 mg/kg combination of ketamine and xylazine (n=3). Parameter of observation from left laterolateral view were: 1) the apicobasilar length of the heart (AB), 2) the width of the heart (CD), 3) the distance between the cranial edge of the fifth rib and the caudal edge of the seventh rib perpendicular to the spine (R5-7), and 4) the vertical depth of the toraks (H). Parameter of observation from dorsoventral view were: 1) the length of the heart (L), 2) the width of the heart (W), and 3) the width of the thorax (T). The result from the heart parameters observation that were measured in left laterolateral view and dorsoventral view shows theres no significantly differ among the groups (P > 0.05). The vertebrae heart size (VHS) values obtained from the sum of the length of the long and the short axes on left laterolateral view. The long axes mean values (A) were 4.35±0.26 v and the short axes mean values (B) were 3.59±0.30 v, therefore VHS mean values were 7.94±0.49 v. On the dorsoventral view, the length of the heart mean values (L) were 4.32±0.29 cm, the width of the heart mean values (W) were 3.33±0.26 cm, and the width of the thorax mean values (T) were 5.85±0.30 cm. In normal conditions, the width of the heart should be less than two-thirds the width of the thorax and values obtained of 3.33<3.72 it shows that the heart is in the normal range. The best ratio to calculated the normal heart dimension in the left laterolateral view was compared the long axes with the vertical depth of the thorax, whereas in dorsoventral view, the length of the heart was compared with the width of the heart.
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