{"title":"Exploring the Acetone Evaporation and Airborne Neurotoxicity Bioassay against Adult Mosquito in the Enclosed Environment of Peet Grady Chamber","authors":"J. Kamaldin, Z. Jaal","doi":"10.14203/JKTI.V20I1.378","DOIUrl":"https://doi.org/10.14203/JKTI.V20I1.378","url":null,"abstract":"Mosquito has comprehensive and sensitive olfactory neuro-sensory located at antenna utilized for detecting airborne organic compounds in search of blood host. Mosquito is also known to have similar neurotransmitters function with human at neural synapses e.g. acetylcholinesterase, esterases and oxidases enzymes. Thus, there is potential use mosquito in predicting neurotoxicity of exogenic volatile organic compounds (VOC) e.g. manufactured acetone. Hence, the study evaluates the suitability to conduct bioassay of VOC neurotoxicity against mosquito in Peet Grady chamber that is commonly used for insecticidal bioassay. Acetone as the representative of VOC is easily evaporized at laboratory temperature of 26 to 29 °C without heating. The acetone evaporation profile on liquid surface and porous solid surface under the Peet Grady chamber is studied to ascertain the consistency of vaporization rate with homogenized distribution. The study showed the acetone has shown consistent vaporization rate of 23 mg/min from liquid surface and 116.3 mg/min from porous surface (filter paper) without heating, in a linear regression of very high positive correlation (r = 1.000) between time and mass of acetone vaporized. However, the non-homogenized distribution of acetone vapours in the Peet Grady chamber directly affected the accuracy to elucidate the neurotoxicity bioassay against mosquito in term of mosquito knockdown. The study suggests the positioning of mosquitoes in the Peet Grady chamber should be lower than the point of acetone vaporization, whereby the mosquitoes are knockdown by acetone vapours within the 20th minute upon reaching concentration of 170.3 to 196.1 ppm.","PeriodicalId":17694,"journal":{"name":"Jurnal Kimia Terapan Indonesia","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84259199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Triwahyuni, Y. Aristiawan, Novita Ariani, H. Abimanyu, T. Anindyawati
{"title":"The Evaluation of Substrates and Trichoderma sp. Isolates for Cellulase Production","authors":"E. Triwahyuni, Y. Aristiawan, Novita Ariani, H. Abimanyu, T. Anindyawati","doi":"10.14203/JKTI.V20I1.384","DOIUrl":"https://doi.org/10.14203/JKTI.V20I1.384","url":null,"abstract":"AbstractAs higher interest was on the lignocellulose-based or second generation bioethanol production, the research was then more focused on the production of cellulase, especially on the domestic enzyme. Trichoderma sp. is considered as one of the most efficient producer of cellulase. This study was conducted to investigate the performance of Trichoderma sp. on a variety of substrates to produce cellulase. Three types of substrate variations and three types of Trichoderma sp. were used in this experiment. The substrate used were wheat bran, rice bran and oil palm empty fruit bunches (EFBs), whereas Trichoderma sp. isolates were encoded as T004, T051 and T063. Production of cellulase was made by solid fermentation for 7 days. The analysis of cellulase activity was done by National Renewable Energy Laboratory (NREL) method for filter paper assay. The results showed that the type of substrate affected the performance of Trichoderma sp. All types of fungus produced cellulase on wheat bran substrate with activity of 0.52 FPU /ml for T004, 0.23 FPU/ml for T051 and 0.27 FPU /ml for T063. With the rice bran substrate and EFBs, only T004 could produce cellulase and the enzyme activity analyzed were 0.08 FPU /ml and 0.008 FPU/ml respectively. Optimation of the buffer addition on enzyme extraction process produces the highest activity 0.85 FPU/mL for T004 with wheat bran substrate. Keywords: cellulase, EFBs, rice bran , Trichoderma sp. , wheat bran","PeriodicalId":17694,"journal":{"name":"Jurnal Kimia Terapan Indonesia","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82273910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Analysis of Learning Problems in Chemistry at Eria Medan Private High School","authors":"Rafika Utami","doi":"10.14203/JKTI.V20I1.377","DOIUrl":"https://doi.org/10.14203/JKTI.V20I1.377","url":null,"abstract":"AbstractThe purpose of this study was to determine the learning process and to analyze the problem of learning chemistry in senior high school. The approach used in this study was a qualitative approach. This mini research was conducted at Eria Medan Private Senior High School in 2017. Research subjects were selected by purposive sampling of 35 Mathematic and Natural Science 1, students grade XI. Data were collected and recorded using observation sheet to measure teacher activities. Students responses were obtained using a questionnaire. The result identified some problems that may inhibit the learning process. Only 37,14 % students were happy to complete or practice with questions and 42.85% of students are actively involved in the learning process. In addition, 80% of students stated that the chemistry books used were less interesting and only 20% of students stated their chemistry book was interesting to read.This study also found that there are misconceptions in teaching concept in the subject of chemical equilibrium.","PeriodicalId":17694,"journal":{"name":"Jurnal Kimia Terapan Indonesia","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91180645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Wen, P. Jiang, Jieh-Ming Huang, A. Haryono, Jianneng Deng, Zhiliang Cao
{"title":"Preparation and Characterization of Polyhedral Octaphenylsilsesquioxane Modified Castor oil based Polyurethane","authors":"Y. Wen, P. Jiang, Jieh-Ming Huang, A. Haryono, Jianneng Deng, Zhiliang Cao","doi":"10.14203/jkti.v20i1.375","DOIUrl":"https://doi.org/10.14203/jkti.v20i1.375","url":null,"abstract":"Vegetable oil-based polyurethanes were synthesized using castor oil (CO) as feedstock, which were characterized by their environmental friendly and renewable properties. Aiming to compensate for shortcomings of these materials, a series of polyurethane/polyhedral octaphenylsilsesquioxane (OPS) hybrids with different OPS contents were prepared by physical mixing in the solutions. Thereafter?chemical structure?morphology and thermal properties of hybrids were characterized through Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), tensile test techniques and static contact angle. The results show that the hybrid polyurethanes display both enhanced glass transition temperatures (Tg), initial decomposition temperature (Td5) and tensile strength with low OPS contents. While with high contents?these values decline with the severe aggregation of nano-particles as shown in the SEM images. Meanwhile, the hybrid polyurethanes displayed enhanced surface hydrophobicity as the contact angle with water revealed","PeriodicalId":17694,"journal":{"name":"Jurnal Kimia Terapan Indonesia","volume":"222 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89157153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}