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Communications in Science and Technology
Published by Komunitas Ilmuwan dan Profesional Muslim Indonesia
ISSN : 25029258     EISSN : 25029266     DOI : -
Core Subject : Engineering,
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.
Arjuna Subject : -
Articles 234 Documents
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Preparation, synthesis and characterizations of La0.7Sr0.3Mn(1-y)Ni(y)O3 alloy Setiawan, Jan; Susetyo, Ferry Budhi; Nanto, Dwi; Simbolon, Silviana; Notonegoro, Hamdan Akbar; Al Farizi, Taufiq; Yunasfi; Tihera, Dinda; Ramlan
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1361

Abstract

Nickel (Ni) doped in the perovskite manganite could result in superior properties. The effect of the Ni on the morphology, crystallographic orientation, and magnetic properties of La0.7Sr0.3Mn(1-y)Ni(y)O3 alloy (y = 0.1, 0.3, 0.5, and 0.7), therefore, was undertaken. La0.7Sr0.3Mn(1-y)Ni(y)O3 alloy was firstly processed using a ball milling process, and again processed through heat treatment and crushing at the end of the synthesis process. Powder alloy was then investigated using a scanning electron microscope equipped with scanning electron microscope and energy dispersive spectroscopy (SEM-EDS), x-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The particle size became smaller and agglomerated as the amount of Ni doping increased. The polycrystal structure phase formed would become more complex when the Ni doping was 0.5 and 0.7, where the dominant phase formed was La2NiO4 even though the La0.7Sr0.3Mn(1-y)Ni(y)O3 phase was still formed. The magnetic characteristics showed that the Ni doping of 0.1 had a higher magnetization value around 4.2 emu/g at room temperature.
Characterization and electrochemical properties analysis of reduced graphene oxide from corncob carbon as an electrode candidate: Synthesized using modified Hummers method Eka Anggriani Odja; Raya, Indah; Maming; Muhammad Zakir; Abd. Karim; Djabal Nur Basir
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1365

Abstract

This research aims to synthesize and characterize reduced graphene oxide (RGO), as well as analyse its electrochemical properties. The synthesis of RGO material from corn cobs went through several stage: carbonization, oxidation and reduction. The synthesis of RGO used a modified Hummer method, and was reduced using the reducing agent ascorbic acid. The synthesized RGO was then characterized using Fourier Transform Independent Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). Electrochemical analysis using the cyclic voltammetry method, the specific capacitance value obtained showed that RGO had a higher capacitance value than GO. The research results showed that carbon from corn cobs, which has not been utilized optimally, can be synthesized as a basic material for making RGO as a quite promising material.
Block-based optimization for enhancing reversible watermarking using reduce difference expansion Arham, Aulia; Adi Nugroho, Hanung
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1368

Abstract

In recent years, reversible watermarking has emerged as a promising technique that safely embeds data in digital images without compromising their originality. This method is particularly useful for sensitive images such as military, art, and medical images, where each pixel contains important information requiring authentication. Researchers have been attempting to develop this method further to increase payload capacity while maintaining visual quality and low computational complexity. In this study, we developed a reversible watermarking with block-based optimization based on Reduced Difference Expansion (RDE) applied to 3×3 pixel blocks, allowing for the embedding of 8?bit data. Based on experimental results from tests conducted on 2 common images and 3 medical images, our method could consistently achieve a payload capacity of up to 0.8924 bpp with a PSNR of 41.077 dB while maintaining good visual quality across various image categories, outperforming previous approaches.
Enhancing bioelectricity generation through co-cultivation of bacteria consortium and microalgae in photosynthetic microbial fuel cell Chaijak, Pimprapa; Kongthong, Alisa
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1372

Abstract

This study investigates the effect of microbial configuration on the electrochemical performance of photosynthetic microbial fuel cells (PMFCs). The PMFC configuration incorporating both bacteria and microalgae exhibited the highest open-circuit voltage (OCV) of 397.95 ± 31.53 mV, significantly higher than that of the OCVs obtained in the sterile control (C1) and the microalgae-only configuration (C2), which were 32.47 ± 22.43 mV and 284.59 ± 12.63 mV, respectively. Furthermore, the PMFC containing only microalgae achieved a current density (CD) of 20.96 ± 0.18 mA/m³ and a power density (PD) of 0.40 ± 0.01 mW/m³ under room temperature conditions. Notably, the combined bacteria and microalgae configuration demonstrated a substantial performance improvement, yielding a significantly higher CD of 49.33 ± 0.36 mA/m³ and PD of 0.78 ± 0.01 mW/m³ at room temperature. This configuration also achieved a maximum decolorization of 93.57 ± 0.10% with a corresponding algal biomass recovery of 134.90 ± 2.69 mg/L. These findings highlighted the critical role of microbial composition in PMFC performance. The combination of bacteria and microalgae yielded superior results compared to other configurations under the investigated conditions.
Physico-chemical characteristics of Ca/P ratio on the composition and structure of oxygenated apatite Jerdioui, S.; Bouammalia, H.; Mejdoubi, E.; Touzani, R.; Azzaoui, K.; Hammouti, Belheir; Sabbahi, R.; Nandiyanto, Asep Bayu Dani; Elansari, L. L.
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1385

Abstract

Phosphocalcic apatites have osteoconductive and bioactive properties that make them suitable for bone reconstruction. But, they are inactive against pathogenic microorganisms that can infect bone tissue. To overcome this limitation, we synthesized oxygen-doped phosphocalcic apatites that can release molecular oxygen as a bioactive molecule. We investigated how the calcium-to-phosphorus ratio (Ca/P) gave impacts on the chemical and structural composition of the oxygen-doped phosphocalcic apatites. We here used the double decomposition method, which involved mixing calcium nitrate and diammonium phosphate solutions in an ammonia buffer. We then characterized the products using several analysis, including infrared absorption spectroscopy, X-ray diffraction, thermal analysis, nitrogen adsorption-desorption, and elemental chemical analysis. It was found that the oxygen-doped phosphocalcic apatites were calcium-deficient and had a well-defined crystallinity at room temperature. After calcination at 900°C, the crystallinity improved further. The thermal analysis showed two mass losses: one at 50°C due to water adsorption and another at 450°C due to CO2 release. The specific surface area was about 100 ± 2 m2/g without any change with the Ca/P ratio. The quantity of molecular oxygen increased with the Ca/P ratio and reached an optimal value of the order of 3.6 ×10-4 mol for Ca/P=1/65 with the chemical formula of Ca9.9(PO4)6(OH)1.25(O2)0.74(CO3)0.01. It is important to make further analysis to know more about the properties of oxygenated apatite, and to combine this apatite with polymers purposely to have biomedical composites. It then can be concluded that the oxygen-doped phosphocalcic apatites could be a promising biomaterial for bone infection prevention and treatment. This research highlights an oxygenation treatment of phosphocalcic apatite and brings new ideas and possibilities for future research and development to get better understanding of the behavior of these biomaterials to be more effective, especially in the biological field. As a perspective, improving the biological properties in these biomaterials needs to be further explored, including experimental parameters for the obtainment of more conclusive results.
Study in the impact of quaternized graphene oxide (QGO) composition as modifier on the chemical, physical, mechanical, and performance properties of polyvinylidene fluoride (PVDF)-based nanocomposite membrane Ashabul Kahfi; Kusumawati, Nita; Setiarso, Pirim; Supari Muslim; Sinta Anjas Cahyani; Nafisatus Zakiyah
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1393

Abstract

Polyvinylidene Fluoride (PVDF) membranes were modified with quaternized graphene oxide (QGO) synthesized from graphene oxide and quaternized ammonium groups. PVDF/QGO membranes were created by blending PVDF and 0.01-0.05 g QGO via phase inversion. FTIR confirmed the successful QGO incorporation. PVDF/QGO membranes exhibited increased mechanical stiffness. Meanwhile, SEM revealed asymmetric morphology with surface and internal pores. AFM showed the membrane with 0.05 g and QGO had the highest surface roughness of 101.2 nm, which increased filtration area and flux. QGO improved hydrophilicity through hydroxyl and quaternary ammonium groups, enhancing water flux up to 1208 Lm?2h?1 for 0.05 g QGO. Cu2+ rejection increased to 75% for 0.05 g QGO membrane due to chelation and adsorption effects. PVDF/QGO membranes displayed bacterial growth inhibition, unlike pristine PVDF. The inhibition zone diameter increased with more QGO, indicating improved antibacterial activity. Overall, this study demonstrated that QGO improved PVDF membranes' hydrophilicity, antibacterial properties, and mechanical strength.
Evaluating 3-D positioning infrastructure quality and utilization: The potential improvement with multi-GNSS methods Atunggal, Dedi; Widjajanti, Nurrohmat; Aditya, Trias
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1403

Abstract

This article evaluates the quality of the national 3-D positioning infrastructure using multi-criteria decision making (MCDM) to simulate the potential application of multi-GNSS method. The MCDM evaluation used coverage and availability of Indonesia Continuous Operating Reference System (INACORS) services, distribution of survey pillars, and accuracy of height determination using the Indonesian Geoid Model (INAGEOID). The term multi-GNSS method refers to the utilization of PPP method as a complement to the conventional differential GNSS method for the production of mapping control points. The results of this evaluation were complemented by a questionnaire analysis on the utilization of positioning infrastructure by respondents from various professional backgrounds. The MCDM evaluation results showed that Java had nearly 100% good or excellent 3-D positioning infrastructure quality. Other regions in Indonesia still had significant areas of average, fair, or even poor quality. The questionnaire results showed that many users have faced some problems in areas with fair or poor infrastructure quality. The application of multi-GNSS method can contribute to reduce up to half of the area with fair and poor positioning infrastructure quality.
Utilizing Pometia Pinnata leaf extract in microwave synthesis of ZnO nanoparticles: Investigation into photocatalytic properties Sulistyo Rini, Ari; Rati, Yolanda; Maheta, Gema; Aji, Arie Purnomo; Saktioto
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1407

Abstract

In this work, ZnO photocatalyst has been synthesized using matoa (Pometia pinnata) leaf extract under various microwave irradiation powers at 360, 540, and 720 Watts for 3 minutes on each. The UV-Vis absorption spectra of ZnO exhibited a peak in the ultraviolet region 300-360 nm. UV-Vis absorption analysis revealed a decrease in the band gap energy from 3.15 eV to 3.10 eV as the irradiation power increased. Field emission scanning electron microscopy (FESEM) images displayed spherical and nanoplatelet morphology with a decrease in particle size observed from 773 to 709 nm with increasing irradiation power. X-ray diffraction (XRD) analysis confirmed the hexagonal wurtzite structure of ZnO with crystallite sizes in the range of ~18-20 nm. The synthesized ZnO nanoparticles was successfully employed as a photocatalyst in 4-nitrophenol degradation, achieving the highest degradation percentage of 82.7% at 540 Watts with a corresponding reaction rate constant of 0.0126/min. In conclusion, the microwave-assisted synthesis of ZnO using on matoa leaf extract demonstrated significant potential for the degradation of organic pollutants, thereby contributing to water purification efforts.
Improving the activity of CO2 capturing from flue gas by membrane gas – solvent absorption process Anwar Abdulla, Maysoon; Hamid Rajab, Mugdad; Humadi, Jasim I.; Noori Mohammed, Harith
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1409

Abstract

This work is focused on increasing the capturing efficiency of carbon dioxide (CO2) through flue gas purification systems. To maximize the CO2 capture process, many process variables such as temperature, flow rates, absorbent concentrations, and nanoparticles were investigated. This study describes the use of a polypropylene hollow fiber membrane contactor to separate CO2 from nitrogen using different solvents, including Potassium carbonate (K2CO3), N-methyl diethanolamine (MDEA), and monoethanolamine (MEA). Also, the presence of silica nanoparticles and piperazine (PZ) enhances the process performance. On the other hand, the amine and mixed amino absorbents MDEA-PZ and MDEA-MEA were prepared and compared based on the absorption capacity. The optimal order of amine absorbent performance when applied to CO2 membrane absorption is MDEA-MEA followed by MDEA-PZ. At a solute concentration of 9%, MDEA-MEA exhibits the highest CO2 removal efficiency, which is 74.12%. However, at a concentration of 11%, MEA, MDEA-PZ, and MDEA have the highest CO2 removal efficiencies of 80.15%, 75.13%, and 63.12%, respectively.
Predictive mapping of surface roughness in turning of hardened AISI 4340 using carbide tools Ginting, Armansyah; Masyithah, Zuhrina
Communications in Science and Technology Vol 9 No 1 (2024)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.9.1.2024.1417

Abstract

This study presents a novel approach to predict surface roughness in the hard turning of AISI 4340 steel using carbide tools, aimed to develop a comprehensive predictive map. The hypothesis that surface roughness can be accurately predicted using a linear regression model was tested and confirmed. Experimental results showed surface roughness in the range of 1.946 to 5.636 microns. Statistical analysis revealed a normal distribution of surface roughness data with linear regression as the best-fit model, significantly determined by feed rate and explaining 98.41% of the variance. Machine learning validated this model, achieving high prediction accuracy (R² = 96.91%, MSE = 0.058, RMSE = 0.242). The innovative predictive map, created using a full factorial design, demonstrated a strong agreement between predicted and validated values. This work highlights the potential of integrating statistical and machine learning techniques for precise surface roughness prediction, recommending industrial validation to enhance machining productivity.

Page 15 of 24 | Total Record : 234

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