IPTEK: The Journal for Technology and Science最新文献

{"title":"Free Radical Scavenging Activity of Chromolaena odorata L. Leaves","authors":"P. Maulida, D. A. Putri, S. Fatmawati","doi":"10.12962/j20882033.v30i3.5409","DOIUrl":"https://doi.org/10.12962/j20882033.v30i3.5409","url":null,"abstract":"Chromolaena odorata is one of the plants used by the community as traditional medicine. Some of community in Ambon, Indonesia used C. odorata leaves as wound medicine. This study aims to evaluate free radical scavenging activity from fraction of methanol extract of C. odorata. Methanol extract of C. odorata leaves is known have good free radical scavenging activity. The fractionation from methanol extract of the C. odorata leaves obtained A-E fraction, where fractions C, D and E showed inhibitory activity against DPPH radicals (2,2-difenill-1-pikrilhidrazil) with IC50 values 63,95; 64.38 and 202.15 μg/mL. Positive control, which is gallic acid, has an IC50 value of 5.29 μg/mL. KeywordsChromolaena odorata, Antioxidant, DPPH, IC50.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76282304","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":"6β-hydroxyipolamiide of Stachytarpheta jamaicensis Leaves","authors":"Y. Yuliana, Fithrotul Auwaliyah, S. Fatmawati","doi":"10.12962/j20882033.v30i3.5408","DOIUrl":"https://doi.org/10.12962/j20882033.v30i3.5408","url":null,"abstract":"Stachytarpheta jamaicensis is one species of Verbenaceae family that is used as a traditional medicine. 6β-hydroxyipolamiide is a natural occuring compound that was successfully isolated from S. jamaicensis leaves. The identification of compound was analyzed by using UV-Vis, Infra-Red (IR) spectrophotometry and Nuclear Magnetic Resonance (NMR) spectrometry. This is the first report that the compound has isolated from this plant.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81338725","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":"Experimental and Numerical Bending Analysis of Steel/Resin-Talk Sandwich Material","authors":"P. Arianto, A. Zubaydi, B. Piscesa, T. Tuswan","doi":"10.12962/j20882033.v30i3.5496","DOIUrl":"https://doi.org/10.12962/j20882033.v30i3.5496","url":null,"abstract":"Sandwich material can be used as the substitute for the ship conventional material. The core sandwich material used in this study consisted of a talk-resin-catalyst. The core mixture proportion is 90% resin and 10% talk. A thick steel plates is used as the face of the core sandwich material. Both experimental and numerical simulations are carried out to investigate the bending or flexural behavior of the proposed sandwich material. Three-point bending test has been carried out to determine the yield stress and maximum stress as well as the damage mechanism of the specimen up-to failure. From the investigation, the first failure process occurred at the mid-span as flexural cracks. As the load continue, these flexural cracks progressed until fully fracture of the core material take places. From the experimental investigation, it was found that the yield stress and maximum stress of the sandwich panel are 22.88 MPa and 28.63 MPa. On the other hand, numerical simulation is carried out using ABAQUS which has shown to be sufficient to predict the response of the sandwich-panel. However, a more sophisticated constitutive model is required to successfully model the experimental behavior in close agreement.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87564669","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":"Study of UV-B Mutation Effect on pH Resistance and Lipid Production of Microalgae Botryococcus braunii","authors":"Thea Prastiwi Soedarmodjo, Fanina Aulia Rachma, H. W. Aparamarta, A. Widjaja","doi":"10.12962/j20882033.v30i3.5475","DOIUrl":"https://doi.org/10.12962/j20882033.v30i3.5475","url":null,"abstract":"Microalgae Botryococcus braunii is a potential biodiesel producer as an alternative for fossil fuels due to its high lipid content. UV-B mutations were carried out to see the effect in microalgae growth at various pHs (3-8). Reduction of nitrogen levels was carried out to see the effect on the growth and lipid production of microalgae. UV-B mutation increased the ability of growth and resistance of B. braunii against low pH. Under low nitrogen conditions, the growth of B. braunii cells would not continue for a longer time. B. braunii which grow in nitrogen depletion medium produced lipid content greater than normal nitrogen. UV-B light mutation also increased the lipid content of B. braunii. At 7 days of incubation, the mutation not only increased lipid content, but also significantly increased the TAG content of B. braunii lipids.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84276966","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":"Activation of TFEB ameliorates dedifferentiation of arterial smooth muscle cells and neointima formation in mice with high-fat diet.","authors":"Yun-Ting Wang, Xiang Li, Jiajie Chen, Bradley K McConnell, Li Chen, Pin-Lan Li, Yang Chen, Yang Zhang","doi":"10.1038/s41419-019-1931-4","DOIUrl":"10.1038/s41419-019-1931-4","url":null,"abstract":"<p><p>Autophagy is recently implicated in regulating vascular smooth muscle cell (SMC) homeostasis and in the pathogenesis of vascular remodeling. Transcription factor EB (TFEB) is a master regulator of autophagy signaling pathways. However, the molecular mechanisms and functional roles of TFEB in SMC homeostasis have not been elucidated. Here, we surveyed the ability of TFEB to regulate autophagy pathway in SMCs, and whether pharmacological activation of TFEB favors SMC homeostasis preventing dedifferentiation and pathogenic vascular remodeling. In primary cultured SMCs, TFEB activator trehalose induced nuclear translocation of TFEB and upregulation of TFEB-controlled autophagy genes leading to enhanced autophagy signaling. Moreover, trehalose suppressed serum-induced SMC dedifferentiation to synthetic phenotypes as characterized by inhibited proliferation and migration. These effects of trehalose were mimicked by ectopic upregulation of TFEB and inhibited by TFEB gene silencing. In animal experiments, partial ligation of carotid arteries induced downregulation of TFEB pathway in the media layer of these arteries. Such TFEB suppression was correlated with increased SMC dedifferentiation and aggravated high-fat diet (HFD)-induced neointima formation. Treatment of mice with trehalose reversed this TFEB pathway suppression, and prevented SMC dedifferentiation and HFD-induced neointima formation. In conclusion, our findings have identified TFEB as a novel positive regulator for autophagy pathway and cellular homeostasis in SMCs. Our data suggest that suppression of TFEB may be an initiating mechanism that promotes SMC dedifferentiation leading to accelerated neointima formation in vascular disorders associated with metabolic stress, whereas trehalose reverses these changes. These findings warrant further evaluation of trehalose in the clinical settings.</p>","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"25 1","pages":"676"},"PeriodicalIF":9.0,"publicationDate":"2019-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742653/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88524084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects CNG Injection Timing on Engine Performance and Emissions Of A Diesel Dual Fuel Engine","authors":"Moch. Aziz Kurniawan, Dori Yuvenda, B. Sudarmanta","doi":"10.12962/j20882033.v30i2.4996","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.4996","url":null,"abstract":" Sequential combustion process on diesel dual fuel engine with compressed natural gas (CNG) fuel was complex. The problems of diesel dual fuel with CNG gas are reduced thermal efficiency and resulting in high carbon monoxide (CO) and unburned hydrocarbon (HC) emissions. The right setting between combustion air, diesel pilot fuel, and CNG gas fuel can improvement the performance and emissions. The experiment was conducted with diesel fuel conventional and dual fuel mode with CNG fuel in a single cylinder, four strokes, constant speed (1500 rpm) diesel engine type diamond DI 800. Performance parameters such as thermal efficiency and specific fuel consumption (SFC), emissions such as CO, HC, and smoke density are determined at five starts of injection timing (SOI) CNG of 70CA, 90CA, 110CA, 130CA, dan 150CA ATDC with ECU programmable of Vemstune software. The results indicated that retarded CNG injection timings improved engine performance and emissions diesel dual fuel. Start of CNG injection timing optimization at 130CA ATDC with increased thermal efficiency 14,35% and decreased specific fuel consumption (SFC) 8,83 % . in addition, it decreased CO emissions 21,35%, HC emissions 17,93%, and PM emissions lower 34,98%. However, engine performance diesel dual fuel lower than a conventional diesel engine. KeywordsDiesel Dual Fuel, the Start of CNG Injection Timing, Engine Performance, Emissions.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74290226","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":"The Experimental Study of The Effect of Air Preheating in MSW Pellet Multi-Stage Downdraft Gasifier","authors":"D. R. Ependi, A. R. Saleh, B. Sudarmanta","doi":"10.12962/j20882033.v30i2.5005","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.5005","url":null,"abstract":"High municipal solid waste generation in Indonesia can be used to substitute fossil energy. MSW is converted into pellet form to uniform moisture content. This study aimed to improve the performance of gasified downdraft gasifier processes by heating air inlets in pyrolysis, oxidation, and reduction zones. Variations of air temperature inlet in these zones are 80 oC, 110 oC, 150 oC, and 210oC. The results of this study obtained the highest air temperature at 210 oC for 969 oC. The syn-gas compositions (CO and H2) at an increase in temperature of 80-210 oC increased from 21.4%, 9.99%, and 1.77% to 22.79%, 10.28%, and 1, 79% respectively. Cold gas efficiency increased by 5.13 % and the lowest tar level was 34.39 mg/Nm3. Based on the result of research, preheated air can improve the efficiency of gasification and reduce tar content in the syngas.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90072836","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":"Friend Relationship Weighting for Academic Performance Prediction on University Delegation at Following Competition","authors":"Eva Firdayanti Bisono, Tora Fahrudin, J. L. Buliali","doi":"10.12962/j20882033.v30i2.5007","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.5007","url":null,"abstract":" Academic performance is an important key to student success or failure. Therefore, academic performance prediction become a popular research on education. In general, several researches used GPA to predicting academic performance. However, there are some aspect that also plays a role in student academic performance, like friend relationship. So, this paper will analyze the correlation between academic performance and friend relationship. Friendship will be seen from communication frequency between students when become University delegation. Each students friend will have weight to show their closeness. In this paper, proposed method gives friendship weight based on communication frequency proportion between student among all student in one faculty. Indeed, close friends have a higher weight than other friends. So, the friendship weight sorted into descending order to get the closest friend. Then, their GPA convert into academic label, i.e. cumlaude, excellent, very good, or drop out. Furthermore, label will be compared to obtaining validation of our hypotheses that friendship plays a role in academic performance achievement. We use scholar student delegation dataset in competition from year 2015 in 7 study programme with 160 scholar students. Experimental results showed that the proposed method can predict academic performance 43% from the total data","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"171 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73550020","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":"Performance Study of Installed an I-65o Type Cylinder at The Upstream of Returning Blade of Savonius Wind Turbine, Comparison With Conventional Savonius Wind Turbine","authors":"G. Sakti, T. Yuwono","doi":"10.12962/j20882033.v30i2.4991","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.4991","url":null,"abstract":"Savonius wind turbine has many advantages over others in that its constructions are simpler and cheaper; it is independent of the wind direction and has a good starting torque at lower wind speeds. However, this type of wind turbine has the lowest performance compared to others types of wind turbine. That is why various studies have been done to improve the performance of the turbine Savonius. This paper is proposed in order to increasing the performance of Savonius wind turbine experimentally by installing an I-65 type bluff body at the upstream of returning blade of the turbine. The experiments are carried out for free stream velocity (U) of 7 m/s corresponds to Reynolds number of about 127.000 (based on the characteristic length of d = 2D-e and free stream velocity (U) from fan used. The center to center distance between the I65 type cylinder and the returning blade turbine relative to turbine blade diameter S/D specified for 1.4. The diameter of I65 type cylinder relative to turbine blade diameter is 0.5. The result of experimental show that in general compared to conventional Savonius wind turbines, the placement of I-65 type cylinder in front of the returning blade of the Savonius wind turbine is effective for improving turbine performance. The results of this experiment show that for Re = 127,000, the power coefficient of the turbine with the I-65 type cylinder is greater than when the turbine has no I-65 type cylinder or conventional Savonius wind turbine. Where in this condition, the maximum coefficient of power the Savonius turbine (CP) with I-65 type cylinder can actually increase to 25.66 % compared to the turbine without the I-65 type cylinder; this is obtained for Tip Speed Ratio of 0.76. KeywordsI-65 Type Cylinder, Savonius Wind Turbine Performance, Upstream Of Returning Blade.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79697651","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":"The Effect of Water Contents to Diesel Fuel-Water Emulsion Fuel Stability","authors":"Joko Suryadi, S. Winardi, T. Nurtono","doi":"10.12962/j20882033.v30i2.4997","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.4997","url":null,"abstract":" The declining world oil and gas reserves along with increasing gas emissions from fossil fuel consumption has received serious attention as an urgent problem worldwide. The alternative solution to the problem uses emulsified fuel which is expected to provide better combustion efficiency and will contribute to emission reductions, such as NOx and particulate matter (PM). The one of most important factor in emulsion fuel is its stability. In this work, the effect of water contents to stability of diesel-water emulsion fuels has been investigated. The stability of emulsion fuel related to coalescence and sedimentation formation. The diesel fuel-water emulsification process was carried out in a standard stirred tank consisting of a cylinder tank (93 mm in diameter) and Rushton disk turbine (40 mm in diameter). Materials used consist of diesel oil (Pertamina DEX), demineralized water, surfactants (Lecithin, Triton X-100 and Tween 80). The surfactant used is a mixture of Lecithin Triton X-100 (76.6%: 23.4%) and Lecithin Tween 80 (45.5%: 54.5%) at 1% total volume of emulsion. The impeller set in constant speed at 1900 rpm. To reduce emulsification energy consumption, water is added gradually into the tank at 2 mL/min of flowrate. Water content varies at 5%, 10%, 20%, and 40% by total volume of emulsion. Physical properties of emulsion fuel such as viscosity and density at room temperature were investigated periodically. The characterization of emulsion fuel stability was measured by slope value of absorbance ratio at wavelength 450 nm and 850 nm. Sediment formation was periodically by visual observation as emulsion phase percentage. Emulsion droplet size was measured by Dynamic Light Scattering (DLS) method. Physical properties of emulsions such as density and viscosity tend to constant value in order of time. Emulsion fuel with 5% water content has the largest volume of emulsion phase in the rest of time, 83 % for L-T emulsion fuel and 95% for L-Tx. The lowest slope value shown by 5% emulsion fuel water content, 8.657×10 for 5% L-T emulsion fuel and -2,084 × 10 for 5% L-Tx emulsion fuel. Droplet size measurement of emulsion shown that different amount of added water caused the different droplet size of emulsion. KeywordsEmulsion Fuel, Mixed Surfactants, Low Energy Emulsification.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79956043","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}