Science and Technology Indonesia最新文献_第10页

Isolation of Cellulase from Selected Fungal Strains and Its Use for Manufacture Microcrystal Cellulose from Kapuk Cortex (Ceiba Pentandra (L.) Gaertn) 从真菌菌株中分离纤维素酶及其在木犀皮微晶纤维素生产中的应用

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.227-234

Mi'rajunnisa Mi'rajunnisa, H. Suryadi, Sutriyo Sutriyo, Y. Lestari

{"title":"Isolation of Cellulase from Selected Fungal Strains and Its Use for Manufacture Microcrystal Cellulose from Kapuk Cortex (Ceiba Pentandra (L.) Gaertn)","authors":"Mi'rajunnisa Mi'rajunnisa, H. Suryadi, Sutriyo Sutriyo, Y. Lestari","doi":"10.26554/sti.2023.8.2.227-234","DOIUrl":"https://doi.org/10.26554/sti.2023.8.2.227-234","url":null,"abstract":"This study aims to obtain cellulase enzymes from selected molds for microcrystalline cellulose preparation from ????-cellulose of kapok cortex. Alpha-cellulose was obtained by biodelignification, and the purified cellulase was obtained from the selected mold. The Microcrystalline cellulose obtained from enzymatic hydrolysis was then identified FTIR and DSC, followed by characterization of microcrystalline cellulose, Particle Size and Distribution Analysis (PSA), and Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX), Loss on drying, pH, bulk density, tapped density, and flow rate. Biodelignification produced 14.88% ????-cellulose, Penicillium sp. the selected mold had the highest cellulase activity, with a cellulolytic index of 4.83. FTIR identification was similar to Avicel PH 101 with a melting point of 244.580°C. Loss on drying was 3.74%, pH was 7.0, particle size ranged from 13.06 to 196.79 ????m, bulk density and tapped density were 0.11 g/cm3 and 0.23 g/cm3, respectively flow rate character is quite good. SEM-EDX was showed that the morphological shape of the microcrystalline cellulose of the kapok cortex is elongated. Microcrystalline cellulose has shown a quite similar in character and can be furthered.","PeriodicalId":21644,"journal":{"name":"Science and Technology Indonesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44689449","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}

引用次数: 0

Interlayer Modification of West Java Natural Bentonite as Hazardous Dye Rhodamine B Adsorption 西爪哇天然膨润土对有害染料罗丹明B吸附的层间改性

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.160-169

S. Priatna, Yusuf Mathiinul Hakim, Sahrul Wibyan, Siti Sailah, R. Mohadi

{"title":"Interlayer Modification of West Java Natural Bentonite as Hazardous Dye Rhodamine B Adsorption","authors":"S. Priatna, Yusuf Mathiinul Hakim, Sahrul Wibyan, Siti Sailah, R. Mohadi","doi":"10.26554/sti.2023.8.2.160-169","DOIUrl":"https://doi.org/10.26554/sti.2023.8.2.160-169","url":null,"abstract":"This work reports the modification of West Java natural bentonite as an effective adsorbent for rhodamine B dye. The modification was finished by sodium intercalation at room temperature to get low-energy preparation. Characterization of bentonite-modified adsorbent was used SEM, XRD, FTIR, and BET analysis. The material pore size and surface area were increased by 0.303 nm and 178.710 m2/g on Na-bentonite. The adsorption mechanism conformed well with the Freundlich isotherm model and pseudo-second-order kinetics equations. The adsorption process by thermodynamic analysis was endothermic and advantageous. Under the optimum condition of pH 6 (confirmed by pHpzc), initial dye concentration of 125 mg/L, and the adsorbent dosage of 0.09 g for 65 minutes, the Na-bentonite has a larger adsorption capacity (Qm) of 142.86 mg/g, while the different adsorbent dosages of 0.11 g for 75 minutes, the adsorption capacity of natural bentonite (Qm) reaches 140.85 mg/g. This work provides a method for establishing a low-energy preparation adsorbent of bentonite-based on Na intercalant as a low-cost and valuable adsorbent for waste dye removal.","PeriodicalId":21644,"journal":{"name":"Science and Technology Indonesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49612816","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}

引用次数: 3

Malachite Green Dye Adsorption from Aqueous Solution using a Ni/Al Layered Double Hydroxide-Graphene Oxide Composite Material Ni/Al双层氢氧化物-氧化石墨烯复合材料对孔雀绿染料的吸附研究

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.280-287

Amri Amri, A. Lesbani, R. Mohadi

引用次数: 0

Experimental Investigation on Thermophysical and Stability Properties of TiO2/Virgin Coconut Oil Nanofluid TiO2/初榨椰子油纳米流体热物理及稳定性的实验研究

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.178-183

Barlin Oemar, A. Arifin, D. Bahrin, Astuti Astuti, D. Ramadhan, Muhammad Abil Rifqy, Muhammad Reza Tinambunan

{"title":"Experimental Investigation on Thermophysical and Stability Properties of TiO2/Virgin Coconut Oil Nanofluid","authors":"Barlin Oemar, A. Arifin, D. Bahrin, Astuti Astuti, D. Ramadhan, Muhammad Abil Rifqy, Muhammad Reza Tinambunan","doi":"10.26554/sti.2023.8.2.178-183","DOIUrl":"https://doi.org/10.26554/sti.2023.8.2.178-183","url":null,"abstract":"This paper shows experimental study results on the thermophysical and stability of nanofluids of Titanium oxide (TiO2) dispersed in high-purity of Virgin Coconut Oil (VCO). Nanofluid samples that functioned as a lubricant were prepared by a two-step preparation method at different volume fractions (0.1, 0.3, and 0.5 vol.%) and different temperatures (28, 40, and 100°C). The dynamic viscosity and density were performed using Falling Ball Viscometer and Pycnometer, respectively. The sedimentation photograph method using a digital camera was applied to analyze the stability. A maximum dynamic viscosity enhancement of 62.78% was recorded for TiO2/VCO nanofluid with 0.5% nanoparticle volume fraction and at the temperature of 100°C). Whereas, the highest density improvement was recorded for TiO2/VCO nanofluid with 0.5% nanoparticle volume fraction. Freshly prepared nanofluids did not show any significant change in stability. However, a trivial phase separation appeared in the samples after 8 days. The results indicated that adding TiO2 nanoparticles increased the dynamic viscosity and density. It can be concluded that the volume in fraction has the effect to enhance the thermophysical stability of TiO2/VCO nanofluids.","PeriodicalId":21644,"journal":{"name":"Science and Technology Indonesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42340986","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}

引用次数: 0

Characterization of Synthesized NiCo2O4 with Trisodium Citrate for Supercapacitor Material: A Preliminary Study 柠檬酸三钠合成NiCo2O4作为超级电容器材料的初步研究

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.245-251

Andriono Manalu, I. Manalu, M. Panjaitan, Ady Frenly Simanullang, Parlindungan Sitorus

{"title":"Characterization of Synthesized NiCo2O4 with Trisodium Citrate for Supercapacitor Material: A Preliminary Study","authors":"Andriono Manalu, I. Manalu, M. Panjaitan, Ady Frenly Simanullang, Parlindungan Sitorus","doi":"10.26554/sti.2023.8.2.245-251","DOIUrl":"https://doi.org/10.26554/sti.2023.8.2.245-251","url":null,"abstract":"Supercapacitors can be called electrostatic double-layer capacitors (EDLCs) or pseudo-capacitors based on their energy storage mechanism. Pseudo-capacitors with metal oxide electrodes that transmit electric charge offer great application power but low stability. This study aims to characterize trisodium citrate (TSC) modified NiCo2O4/rGO electrodes as a preliminary study for the NiCo2O4 nanoparticle pseudo-capacitor. The materials were characterized using SEM (Scanning Electron Microscopy), XRD (X-Ray Diffractometer), FT-Raman (Fourier Transform Raman Spectroscopy), and FTIR (Fourier Transform Infrared Spectroscopy). All of these analyses confirmed that NiCo2O4 was manufactured successfully using TSC. At XRD, the angles of 2????, namely 45.04 and 53.34°, matched the plane of the cubic phase nanorod crystals of NiCo2O4 with values of 400 and 511, respectively. In the Raman examination, the presence of rGO, which increased the crystallinity of NiCo2O4 nanoparticles, was confirmed. FTIR analysis indicated that the 1550-1600 cm−1 corresponds to a C=C functional group in an aromatic ring or a C=O ????-???? structure, and the wavenumber of 2300 cm−1 corresponds to the OH group in TSC, an alkanoate derivative. SEM analysis determined that NiCo2O4 nanoparticles with 1 mmol TSC are the ideal material for supercapacitor electrodes, as the structure is the most uniform, soft, and tidy. Further analysis is needed to confirm the stability of the modified material.","PeriodicalId":21644,"journal":{"name":"Science and Technology Indonesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42527801","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}

引用次数: 0

Profiling of Active Compounds of Extract Ethanol, n-Hexane, Ethyl Acetate and Fraction Ethanol of Star Anise (Illicium verum Hook. f.) and Determination of Total Flavonoids, Total Phenolics and Their Potential as Antioxidants 八角茴香提取物乙醇、正己烷、乙酸乙酯和乙醇组分的活性成分分析。f.)和总黄酮、总酚类物质及其抗氧化剂潜力的测定

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.219-226

M. Syukur, Masitoh Suryaning Prahasiwi, Nurkhasanah Nurkhasanah, S. Yuliani, Y. Purwaningsih, E. Indriyanti

{"title":"Profiling of Active Compounds of Extract Ethanol, n-Hexane, Ethyl Acetate and Fraction Ethanol of Star Anise (Illicium verum Hook. f.) and Determination of Total Flavonoids, Total Phenolics and Their Potential as Antioxidants","authors":"M. Syukur, Masitoh Suryaning Prahasiwi, Nurkhasanah Nurkhasanah, S. Yuliani, Y. Purwaningsih, E. Indriyanti","doi":"10.26554/sti.2023.8.2.219-226","DOIUrl":"https://doi.org/10.26554/sti.2023.8.2.219-226","url":null,"abstract":"Profiling of chemical compounds on star anise extract and fractions showed the content and looked for active compounds. The main compounds in alkaloids, flavonoids, saponins, phenolics, and triterpenoid forms were identified based on phytochemical screening. FTIR and GC-MS analysis were used to purify the extract and fractions’ main compounds. After analyzing the main components of extract and fractions, a correlation was made between the total phenolic and flavonoid content. The total phenolic content was determined by adding folincalteau complexing solution converted to gallic acid equivalent (GAE), while the total flavonoid content was determined by AlCl3 complexing solution converted to Quercetin Equivalent (QE). The total phenolic yields for extract ethanol, n-hexane fraction, ethyl acetate fraction, and fraction ethanol were obtained at 106.45, 52.30, 93.46, and 148.97 mgGAE/g, respectively. Then the total flavonoid results were 107.45, 58.94, 148.99, 140.01 mgQE/g. The total content of phenolics and flavonoids illustrated the number of active compounds that have a role as free radical scavengers due to their group. Antioxidant activity was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) on extracts and fractions, with the best IC50 results obtained in the ethanol fraction 0.416 mg/mL.","PeriodicalId":21644,"journal":{"name":"Science and Technology Indonesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44475783","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}

引用次数: 0

Extension of Exponential Pareto Distribution with the Order Statistics: Some Properties and Application to Lifetime Dataset 具有阶统计量的指数Pareto分布的扩展：一些性质及其在寿命数据集中的应用

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.265-279

A. O. Adeyemi, I. Adeleke, E. Akarawak

{"title":"Extension of Exponential Pareto Distribution with the Order Statistics: Some Properties and Application to Lifetime Dataset","authors":"A. O. Adeyemi, I. Adeleke, E. Akarawak","doi":"10.26554/sti.2023.8.2.265-279","DOIUrl":"https://doi.org/10.26554/sti.2023.8.2.265-279","url":null,"abstract":"The Exponential Pareto (EP) model has been extended by applied and theoretical statisticians for wider applications and new knowledge using different techniques but the Weibull-X technique has not been considered. This article proposed a new extension of the EP model called the Weibull-Exponential Pareto (WEP) distribution to provide better modeling that fits real-life datasets and to explore the statistical theory of order statistics from the proposed distribution. Statistical properties investigated include the Shannon and Renyi entropies; the moments and moment generating function. Distribution of order statistics and the moment of order statistics were derived including the mean and variance of order statistics. WEP distribution has unimodal, decreasing, and increasing failure rates; and it can be negatively or positively skewed and approximately symmetric with the potential for fitting platykurtic, mesokurtic, and leptokurtic lifetime data. The parameters of the distribution were estimated using the method of maximum likelihood estimation (MLE), which was examined for consistency through a simulation study. The performance of the proposed distribution was investigated by application to flood peaks exceedances and some lifetime datasets from engineering. The results from data analysis using the R-software revealed that the WEP distribution has the potential to provide a superior model that fits the three data sets better than some notable existing distributions and previous extensions of the EP model in the literature. The statistical property of order statistics extended in the study established some important results that characterized some notable lifetime distributions in the literature.","PeriodicalId":21644,"journal":{"name":"Science and Technology Indonesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46245905","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}

引用次数: 0

Best Proximity Point Results in Fuzzy Normed Spaces 模糊赋范空间中的最佳邻近点结果

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.298-304

Raghad I. Sabri, Buthainah A. A. Ahmed

引用次数: 1

Perturbed Trapezoid Like Inequalities 扰动类梯形不等式

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.205-211

W. Alshanti, I. Batiha, Ahmad Alshanty, A. Zraiqat, I. Jebril, Ma’mon Ahmad Abu

引用次数: 0

Spatial Autoregressive Quantile Regression with Application on Open Unemployment Data 空间自回归分位数回归及其在公开失业数据中的应用

Science and Technology Indonesia Pub Date : 2023-04-15 DOI: 10.26554/sti.2023.8.2.321-329

F. Yanuar, Tasya Abrari, Izzati Rahmi HG, A. Zetra

{"title":"Spatial Autoregressive Quantile Regression with Application on Open Unemployment Data","authors":"F. Yanuar, Tasya Abrari, Izzati Rahmi HG, A. Zetra","doi":"10.26554/sti.2023.8.2.321-329","DOIUrl":"https://doi.org/10.26554/sti.2023.8.2.321-329","url":null,"abstract":"The Open Unemployment Level (OUL) is the percentage of the unemployed to the total labor force. One of the provinces with the highest OUL score in Indonesia is West Java Province. If an object of observation is affected by spatial effects, namely spatial dependence and spatial diversity, then the regression model used is the Spatial Autoregressive (SAR) model. Quantile regression minimizes absolute weighted residuals that are not symmetrical. It is perfect for use on data distribution that is not normally distributed, dense at the ends of the data distribution, or there are outliers. The Spatial Autoregressive Quantile Regression (SARQR) is a model that combines spatial autoregressive models with quantile regression. This research used the data regarding OUR in West Java in 2020 from the Central Bureau of Statistics. This study develops to modeling the Open Unemployment Level in all province in Indonesia using modified spatial autoregressive model with the quantile regression approach. This study compares the estimation results based on SAR and SARQR models to obtain an acceptable model. In this study, it was found that the SARQR model is better than SAR at dealing with the problems of dependency and diversity in spatial data modeling and is not easily affected by the presence of outlier data.","PeriodicalId":21644,"journal":{"name":"Science and Technology Indonesia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47935615","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}

引用次数: 2