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Communications in Science and Technology
ISSN : 25029258     EISSN : 25029266     DOI : -
Core Subject : Engineering,
Communication in Science and Technology [p-ISSN 2502-9258 | e-ISSN 2502-9266] is an international open access journal devoted to various disciplines including social science, natural science, medicine, technology and engineering. CST publishes research articles, reviews and letters in all areas of aforementioned disciplines. The journal aims to provide comprehensive source of information on recent developments in the field. The emphasis will be on publishing quality articles rapidly and making them freely available to researchers worldwide. All articles will be indexed by Google Scholar, DOAJ, PubMed, Google Metric, Ebsco and also to be indexed by Scopus and Thomson Reuters in the near future therefore providing the maximum exposure to the articles. The journal will be important reading for scientists and researchers who wish to keep up with the latest developments in the field.
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Articles 234 Documents
Isotherm adsorption characteristics of carbon microparticles prepared from pineapple peel waste Nandiyanto, Asep Bayu Dani; Santiuly Girsang, Gabriela Chelvina; Maryanti, Rina; Ragadhita, Risti; Anggraeni, Sri; Fauzi, Fajar Miraz; Sakinah, Putri; Astuti, Asita Puji; Usdiyana, Dian; Fiandini, Meli; Dewi, Mauseni Wantika; Al-Obaidi, Abdulkareem Sh. Mahdi
Communications in Science and Technology Vol 5 No 1 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1227.71 KB) | DOI: 10.21924/cst.5.1.2020.176

Abstract

The objective of this study was to investigate isotherm adsorption of carbon microparticles from pineapple peel waste. Carbon microparticles were prepared by carbonizing pineapple peel waste at 215-250°C and grinding using a saw-milling process. To investigate adsorption properties of carbon microparticles, experiments were done by evaluating adsorption of curcumin (as a model of adsorbate) in the ambient temperature and pressure under constant pH condition. To confirm the adsorption characteristics, carbon particles with different sizes (i.e., 100, 125, and 200 ?m) were tested, and the adsorption results were compared with several standard isotherm adsorption models: Langmuir, Freundlich, Temkin, and Dubinin- Radushkevich. To support the adsorption analysis, several characterizations (i.e., optical microscope, sieve test, and Fourier transform infrared analysis) were conducted. The adsorption test showed that the adsorption profile is fit to the Freundlich model for all variations, indicating the multilayer adsorption process on heterogeneous surfaces and interactions between adsorbate molecules. The results from other isotherm models also confirmed that the adsorption process occurs physically via Van der Waals force in binding adsorbate on the surface of adsorbent.
Thin film composite polyelectrolyte multilayer nanofiltration membrane fabricated using spin assisted layer by layer assembly: Application of solution diffusion film model Alghamdi, Ahmad; Fadhillah, Farid
Communications in Science and Technology Vol 5 No 1 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (998.886 KB) | DOI: 10.21924/cst.5.1.2020.177

Abstract

Thin Film Composite (TFC) Polyelectrolyte Multilayer (PEM) Nanofiltration (NF) membrane consisting of multilayer of Poly(diallyl dimethyl ammonium chloride) (PDAC) and Poly(sodium 4-styrenesulfonate) (PSS) deposited on polyethersulfone (PES) support was prepared using spin-assisted layer by layer assembly (SA-LbL). This work is an effort to discover new material having better characteristics and performance than commercial polyamide (PA) NF membrane. Two main operating conditions namely temperature and salt concentration were investigated and the effect of both on membrane performance was studied. Solution-diffusion Film Model (SDFM) membrane employing two fitting parameters i.e. membrane salt permeability (PS) and stagnant layer salt permeability PS(d), was used to explain membrane transport across the membrane. The result showed an good agreement between experimental and observed rejection rate suggests PEM membrane behaves similar to typical solution diffusion-type composite membrane and SDFM can be used to predict the membrane performance and behavior.
Antifungal activity of microcapsule propolis from Tetragonula spp. to Candida albicans Pratami, Diah Kartika; Indrawati, Teti; Istikomah, Iis; Farida, Siti; Pujianto, Paksi; Sahlan, Muhamad
Communications in Science and Technology Vol 5 No 1 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (591.231 KB) | DOI: 10.21924/cst.5.1.2020.178

Abstract

Propolis is a mixture of resin and saliva of Tetragonula spp. that have antifungal activity. The purpose of this study was to develop spray-dried microcapsule propolis (SDMP) and to analyze its antifungal activity to Candida albicans. The SDMP was obtained using a spray drying method by maltodextrin and gum arabic coating. The antifungal activity of SDMP of rough propolis (taken from the outside beehive) and smooth propolis (taken from the inside beehive) was analyzed. The macroscopic characterization showed that SDMP has a powder form with brownish-yellow color. The microscopic characterization showed SDMP has a spherical uniform particle shape with particle size 9.32 - 14.61 µm. The encapsulation efficiency of smooth and rough SDMP was 81.22% and 83.04%; moisture content 5.58% and 5.84%; water solubility 98.19% and 98.31%, respectively. The microbial inhibitory concentration to C. albicans was the diameter of 6.33±1.5 to 10±2.5 mm. SDMP displayed remarkable activity in the assays against C. albicans.
Utilization of extracellular polymeric substances (EPS) immobilized in epoxy polymer as double ion exchanger biosorbent for removal of chromium from aqueous solution Kistriyani, Lilis; Salimin, Zainus; Chafidz, Achmad
Communications in Science and Technology Vol 5 No 1 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (688.555 KB) | DOI: 10.21924/cst.5.1.2020.179

Abstract

Cation and industrial pollutant anions are removed from wastewater using organic cation and anion exchange resin. "Extracellular Polymeric Substance" (EPS) from bacterial extraction can accumulate cation and anion elements through biosorption by adsorption mechanism, ion exchange, formation of complex compounds and hydrogen bonds. EPS can be used as an biosorbent and ion exchange bioresin replacing organic resins, because EPS contains organic functional groups that are negatively charged (RCOOH, ROPO3H, ROPO3Na, ROSO3H, ROSO3Na, etc.) cation absorbers and positively charged (ROH, RCNH2HCOOH, etc.) anion absorber. EPS consists of 40-95% polysaccharide compounds, protein 1-60%, nucleic acids 1-10%, lipids 1-10% and the remaining amino acid polymers and other compounds. The tannery industry produces trivalent (Cr+3) chromium pollutants at levels of 15.2 ppm and hexavalent (CrO4-2 or Cr2O7-2) levels of 0.77 ppm which exceeds the standard quality for a total Cr of 0.6 ppm. Cr pollutants are very dangerous for human health. Research had been done on the use of immobilized EPS bioresin in epoxy polymers for chromium binding. EPS was extracted from bacterial activated sludge by centrifugation at 9000 rpm for 20 minutes at 4°C, the filtrate was EPS. The analysis showed EPS content were 16% fat, 12% carbohydrate, and 16% protein. The functional group analysis results with infrared ray spectroscopy (FTIR) showed EPS containing chemical bonds such as -CH, -OH, -NH, and -C=O which proved that EPS extraction contained RCOOH, ROH, and RCNH2HCOOH functional components which were exchanging components cations and anions. Epoxy polymers were prepared by mixing bisphenol A monomers and 1: 1 ratio epichlorohydrin. Immobilized EPS double ion exchange biorecin in epoxy polymers was prepared by mixing 200 mg EPS and 1800 mg epoxy. The binding of chromium ions in the resin was carried out by recirculating the chromium solution through a burette column filled with 2 rams of bioresin at pH 5, 6 and 7. The optimum results gave chromium ion absorption efficiency of 89.20% at pH 5. Column operations could be optimized by varied the amount of bioresin used.
Three-dimensional pore structure of activated carbon monolithic derived from hierarchically bamboo stem for supercapacitor application Taer, Erman; Pratiwi, Lini; Apriwandi, Apriwandi; Mustika, Widya Sinta; Taslim, Rika; Agustino, Agustino
Communications in Science and Technology Vol 5 No 1 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1000.712 KB) | DOI: 10.21924/cst.5.1.2020.180

Abstract

A three-dimensional pore structure on activated carbon derived from hierarchically bamboo stem was synthesized in the monolithic form for increased applicability as a supercapacitor electrode. The preparation involved two step carbonizations, using a chemical activation at different concentrations. Subsequently, the morphology, chemical content, specific surface area and pore size distribution, as well as crystalline degree were evaluated with scanning electron microscopy, energy X-ray (EDX), N2 sorption and X-ray diffraction, respectively. Therefore, cyclic voltammetry (CV) was used to assess the electrochemical performance, in a two electrode system. The result shows the significant impact of the three-dimensional structure on electrochemical performance, and the optimized sample exhibited specific capacitance of 168.8 F g-1, energy density of 23.44 Wh kg-1, and power density of 84.46 W kg-1.
Silylated-montmorillonite as co-adsorbent of chitosan composites for methylene blue dye removal in aqueous solution Saputra, Ozi Adi; Kurnia; Pujiasih, Septi; Rizki, Vanani Nur; Nurhayati, Betty; Pramono, Edi; Purnawan, Candra
Communications in Science and Technology Vol 5 No 1 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1045.12 KB) | DOI: 10.21924/cst.5.1.2020.182

Abstract

Industrialization plays important role in the economy of developing countries, including increasing community welfare. However, the presence of poorly industries waste disposal system has negative impact to the environment. Therefore, it is necessary to overcome this problem with low-cost technology, called adsorption. In this research, silylated-montmorillonite (sMMt) has been successfully prepared as supporting material for adsorption of methylene blue by chitosan. The sMMt was characterized by FTIR, XRD, and elemental mapping techniques. The chitosan/sMMt composites were prepared through dissolution-precipitation method and produced rod-like morphology as observed by SEM. The adsorption process was carried out in a batch method by studying the pH and the adsorption contact time. The adsorption kinetic mechanism of the chitosan/sMMt nanocomposite followed pseudo-second order rather than Lagergren model indicating chemisorption predominant. The addition of silylated-montmorillonite into chitosan enhanced the methylene blue dye removal performance, which evidenced by improving Qe values by 10% compared to chitosan.
Block cipher four implementation on field programmable gate array Kurniawan, Yusuf; Rizqulloh, Muhammad Adli
Communications in Science and Technology Vol 5 No 2 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.5.2.2020.184

Abstract

Block ciphers are used to protect data in information systems from being leaked to unauthorized people. One of many block cipher algorithms developed by Indonesian researchers is the BCF (Block Cipher-Four) - a block cipher with 128-bit input/output that can accept 128-bit, 192-bit, or 256-bit keys. The BCF algorithm can be used in embedded systems that require fast BCF implementation. In this study, the design and implementation of the BCF engine were carried out on the FPGA DE2. It is the first research on BCF implementation in FPGA. The operations of the BCF machine were controlled by Nios II as the host processor. Our experiments showed that the BCF engine could compute 2,847 times faster than a BFC implementation using only Nios II / e. Our contribution presents the description of new block cipher BCF and the first implementation of it on FPGA using an efficient method.
Role of Gd addition on machinability of Al-15%Mg2Si in-situ composite during dry turning Nanda, Is Prima; Ghandvar, Hamidreza; Idris, Mohd Hasbullah; Hanif, Auliya; Arafat, Andril
Communications in Science and Technology Vol 5 No 2 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.5.2.2020.186

Abstract

Recently, Al-Mg2Si in-situ composites have achieved considerable attention due to their excellent physical and mechanical properties. In fact, there are some limitations of knowledge regarding the machinability characteristics of these composites - particularly when being inoculated with rare earth additions. This study in turn aimed to investigate the influence of machining parameters as well as Gd addition on the machinability of Al-15%Mg2Si composite. To examine the effect of modifier (1.0 wt. % Gd) and machining parameters (feed rate, cutting speed), microstructural evolution, surface roughness (Ra) and cutting force (Fc) were evaluated during dry turning. The results revealed that Gd addition as modifier element led to better surface roughness and higher cutting force owning to the modification of Mg2Si particle structure as well as the formation of Gd intermetallic compounds.
Techno-economic analysis for the production of LaNi5 particles Nandiyanto, Asep Bayu Dani; Maulana, Muhammad Irfansyah; Raharjo, Jarot; Sunarya, Yayan; Minghat, Asnul Dahar
Communications in Science and Technology Vol 5 No 2 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.5.2.2020.195

Abstract

LaNi5 is widely used in various applications. Many methods to produce LaNi5 particles have been reported but information for the large-scale production, so far, is less available. This study aimed to evaluate the project for the production of LaNi5 particles using combustion-reduction (CR) and co-precipitation-reduction (CPR) methods based on engineering and economic perspective. Engineering evaluation was conducted by evaluating the CR and CPR processes from stoichiometry. For the economic evaluation, several economic parameters were calculated in the ideal condition including gross profit margin (GPM), payback period (PBP), break-even point (BEP), cumulative net present value (CNPV), profitability index (PI), internal rate return (IRR), and return on investment (ROI). For the worst cases in the project, it was done by calculating both the internal problems (i.e., raw materials, sales, utility, labor, employee, fixed cost, variable cost, and production capacity) and the external issues (i.e., taxes and subsidiaries). The engineering analysis provided the information that CR and CPR projects are prospective for being able to be done using commercial apparatuses. The economic analysis from GPM, PBP, BEP, CNPV, and PI showed the positive results, while IRR and ROI showed the negative ones, indicating that the projects are acceptable for large-scale production, but it seems to be less attractive for industrial investors. The analysis also confirmed that the CR process was more prospective than the CPR process. This work has demonstrated the important of the projects for further developments.
Microalgae production using photo-bioreactor with intermittent aeration for municipal wastewater substrate and nutrient removal Afifah, Anshah Silmi; Suryawan, I Wayan Koko; Sarwono, Ariyanti
Communications in Science and Technology Vol 5 No 2 (2020)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.5.2.2020.200

Abstract

Microalgae has emerged as a promising approach for removing substrate and nutrient from wastewater with the concomitant biofuel production. The substrate and nutrient removal are influenced by several factors such as C/N ratio, F/M ratio, pH, and DO. This study aims to determine the efficiency of substrate and nutrient removal with the growth rates of microalgae and biomass by varying the addition of aeration and substrate. Intermittently aerated reactors were used with the flow rate of 14 L/minute. The batch reactors were prepared by adding glucose substrate of 50 mg/L (Ra0A), 100 mg/L (Ra0B), and 150 mg/L (Ra0C) without aeration; 50 mg/L (Ra12A), 100 mg/L (Ra12B), and 150 mg/L (Ra12C) with 12-hour aeration, and 50 mg/L (Ra24A), 100 mg/L (Ra24B), and 150 mg/L (Ra24C) with 24-hour aeration. The substrate removal, expressed as chemical oxygen demand (COD) in the reactor with aeration, showed the efficiency of 73.88% ± 2.05 (12-hour aeration), 75.2% ± 3.97 (24hours aeration), and 69.86% ± 5.69(without aeration). Nutrient removal as ammonia-N (NH3-N) gave high removal value of 98.3% ± 0.11 and the removal of nutrient as phosphate (PO3-4) showed the efficiency of 54.3% ± 0.1. The growth rate of microalgae and biomass exhibited the highest value in Ra24C reactor with the values of 0.0229/day and 0.1295/day, respectively. The pH values indicated a shift from normal to alkaline while DO values increased by the addition of 12 and 24-hour aeration.

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