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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 209 Documents
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Tuning the magnetic states in AA-stacked bilayer zigzag graphene nanoribbons Prayitno, Teguh Budi
Communications in Science and Technology Vol 7 No 1 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.1.2022.823

Abstract

Available reports mentioned that the magnetic ground state in the AA-stacked bilayer zigzag graphene nanoribbons is the non-magnetic state. As a consequence, it is impossible to exploit magnetism for future electronic devices. This paper aims to show how to generate magnetism in the AA-stacked bilayer zigzag graphene nanoribbons by employing ?rst-principles calculations. As we stacked different ribbon widths, the magnetic ground states appeared for all the thicknesses. In general, the G-type antiferromagnetic state, which is the antiferromagnetic alignment between both intraplane- and interplane-edge carbon atoms, is the ground state for all the thicknesses. We also found that the degenerate magnetic ground states and excited states may appear under certain thicknesses, thus yielding the richness of the magnetic state. As hole-electron doping was applied, a phase transition of magnetic ground state emerged for certain thicknesses, indicating that a new magnetic ground state in the AA-stacked bilayer zigzag graphene nanoribbons can be tuned by the doping.
Mg/Cr-(COO)22- layered double hydroxide for malachite green removal Palapa, Neza Rahayu; Badri, Arini Fousty; Mardiyanto; Mohadi, Risfidian; Taher, Tarmizi; Lesbani, Aldes
Communications in Science and Technology Vol 7 No 1 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.1.2022.851

Abstract

Mg/Cr layered double hydroxide (LDH) was prepared and modified using an intercalation of oxalate anions ((COO)22-) to form Mg/Cr-(COO)22. The materials were then investigated to malachite green removal to determine the adsorption ability. Furthermore, the desorption process and regeneration of adsorbent were systematically conducted. The adsorption of green malachite on Mg/Cr- LDH and Mg/Cr-(COO)22- materials fitted to the pseudo-second-order (PSO) kinetic model and Freundlich isotherm model with an adsorption capacity of 33.784 mg/g (333K) for Mg/Cr LDH and 64.516 mg/g (333K) for Mg/Cr-(COO)22-. Thermodynamic data showed that the adsorption process was spontaneous and endothermic. Also, the appropriate reagent desorption study was found as hydrochloric acid and material regeneration studies exhibited a good recycling performance after 3 times cycles and, the Mg/Cr-oxalate showed a good performance for malachite green adsorption. It can be concluded that Mg/Cr--(COO)22- can adsorb the dye stuffs effectively.
Fabrication and characterization of fly ash-based geopolymer and its performance for immobilization of heavy metal cations Iqbal, Rendy Muhamad; Supriadi, Warih; Burhan, R.Y. Perry; Nurherdiana, Silvana Dwi; Hidayati, Ririn Eva; Subaer, Subaer; Bayuaji, Ridho; Fansuri, Hamzah
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.868

Abstract

In this study, the geopolymer from fly ash as based-raw material has been examined on the ability of several heavy metal ions immobilization. The fly ash has been provided from PT IPMOMI which firstly analyzed the physical and chemical properties. Fly ash and heavy metals were mixed with an activator base until homogeneous, then cast into a cylindrical shape mold following ASTM C 39-86 and left for 7 days. After that, the geopolymer was characterized by SEM, FTIR, XRD, compressive strength test and TCLP. The diffractogram of PT. IPMOMI fly ash exhibited the existence of mullite, alumina and iron oxide phase, which were suitable with XRF result. From FTIR spectra, the vibration on finger print area appeared indicating the vibration of T-O-T from geopolymer network. The observation revealed that the addition of Pb2+ cations caused microcracking from SEM image and affected the compressive strength of the geopolymer. Sr2+ was an ion that was very easilyleached compared to other three ions, and it caused a weak interaction between Sr2+ and geopolymer network. The higher amount of metal ions into the geopolymer network reduced the compressive strength of geopolymer. Sr2+-geopolymer had a lower compressive strength compared to Pb2+, Cd2+, and Co2+.
Study of green reductant effects of highly reduced graphene oxide production and their characteristics Chasanah, Uswatul; Trisunaryanti, Wega; Triyono; Oktaviano, Haryo Satriya; Santoso, Iman; Fatmawati, Dyah Ayu
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.906

Abstract

The study of the green reductant effects to produce reduced graphene oxide (rGO) has been completed successfully. The reduction of graphene oxide (GO) was carried out chemically using various reductants such as ascorbic acid (rGO-AA), gallic acid (rGO-AG), and trisodium citrate (rGO-NS). The GO was prepared using the Tour method at a temperature of 65 ? for 6 hours with potassium permanganate: graphite weight ratio 1:3.5. The results showed that rGO-AA had the highest electrical conductivity value of 755.70 S/m, with characteristics such as a surface area of 255.93 m2/g, a pore volume of 0.61 cm3/g, an average pore diameter of 7.10 nm, ID/IG ratio of 1.93, and three graphene layers in the material nanostructure stack. Therefore, it can be concluded that the reduction of GO with ascorbic acid (rGO-AA) is the most effective in producing rGO.
Microwave-assisted biosynthesis of flower-shaped ZnO for photocatalyst in 4-nitrophenol degradation Sulistyo Rini, Ari; Aji, Arie Purnomo; Rati, Yolanda
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.937

Abstract

In this paper, the flower-shaped ZnO particles have been prepared via microwave-assisted biosynthesis technique using an aqueous extract of Sandoricum koetjape peel at various irradiation powers, i.e. 180, 360, 540, and 720 Watt. The synthesized flower-shaped ZnO particles were characterized using UV-Vis spectroscopy, x-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). The UV-vis spectra exhibited ZnO absorption peaks in the UV region with band gap energy in the range of 3.25 - 3.29 eV. XRD analysis confirmed the hexagonal wurtzite crystal with the high purity of ZnO particles. The flower-shaped morphology of ZnO was evident in FESEM images with the decrease of particle diameter as the radiation power increased from 257 to 447 nm. ZnO prepared at 720 Watt (Z-720) succeeded in degrading 4-nitrophenol with the highest efficiency of 84.8 % after 240 min. Consequently, biosynthesis ZnO will have a great opportunity to be applied in degrading wastewater pollutants.
Synthesis and characterization of plate-like vanadium doped SrBi4Ti4O15 prepared via KCl molten salt method Sari, Puspa; Himmah, Suci Noerfaiqotul; Hardian, Arie; Aini, Nur; Prasetyo, Anton
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.940

Abstract

SrBi4Ti4O15 is one of four-layered Aurivillius compound family member that can be used as photocatalyst material that works in the violet light region. To expand its work function range can be conducted by doped with metal elements to SrBi4Ti4O15 as results reduced its band gap energy. In this research, we synthesized vanadium doped SrBi4Ti4O15 (SrBi4Ti4-nVnO15 (n= 0, 0.05, 0.1, and 0.15)) by molten salt method (used KCl salt). The diffractogram sample showed that the target compounds SrBi4Ti4-nVnO15 (n= 0, 0.05, 0.1, and 0.15) had been successfully synthesized with the space group A21am without impurities. The SEM micrographs showed the particle shape of SrBi4Ti4-nVnO15 (n= 0, 0.05, 0.1, and 0.15) was plate-like (sheets) and V dopant did not cause agglomeration. The result of Kubelka-Munk equation calculation showed that the V dopant can reduced the band gap energy value from 3.04 eV (408 nm) to 2.84 eV (437 nm)
Techno-economic analysis of the process for obtaining Bioethanol from rice husks and whey Laborde, María Fernanda; Capdevila, Veronica Elisabeth; Ponce-Ortega, José María; Gely, María Cristina; Pagano, Ana María
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.951

Abstract

This work proposes a novel integrated process for second-generation bioethanol production with an approach simulated in Aspen HYSYS®. Rice husk and dairy whey were used to revalorize for this bioprocess. The energy recovery of the bioprocess was optimized using the Pinch method; savings of 45.45% and 100% were obtained for heating and cooling utilities, respectively, concerning the process without a heat exchange network (HEN). It was possible to compare the costs of mutually exclusive alternatives between the process alternatives with andwithout HEN. The capital investment with HEN was similar to the process without HEN. Instead, savings by 77.8% of utility costs per year was found in the process with HEN. A differential cash flow for ten years was generated, and a positive differential net present value (NPV) was determined. Therefore, HEN is an economically convenient and environmentally friendly option since energy consumption reduction canminimize environmental damage.
Assisted ultrasonic wave of vanillin derivatives synthesis and antioxidant activity using DPPH method Retnosari, Rini; Sari, Karina Kurnia; Marfu'ah, Siti; Sutrisno; Rachman, Ihsan Budi
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.963

Abstract

In recent years, the need for compounds with antioxidant activities have expanded. Generally, the natures of these compounds involve the presence of conjugated double bonds, phenolic groups, and resonance effects on the structure. One of the compounds with the phenolic group is vanillin. It can be modified into the derivative of 1,8-dioxo-octahydroxantene compound due to its aldehyde content. Meanwhile, 1,8-dioxo-octahydroxantene compound has two 2- cyclohexenone rings bound in the pyran ring and one phenolic group, expected to carry more excellent antioxidant activity than vanillin. The 9-(4-hydroxy-3-methoxyphenyl)-3,4,5,6,7,9- hexahydro -1H-xantene-1,8(2H)-dione (Compound 1) was synthesized from 1,3- cyclohexanedione and vanillin through Knoevenagel's condensation reaction aided with an acid catalyst with a single reaction phase. Besides, green chemistry was adopted in this study using environmentally friendly catalysts from lime juice and ultrasonic wave. The synthesized compounds' structure was confirmed through the spectrophotometer IR, GC-MS, and 1H-NMR spectrometer, while its antioxidant activity was tested using the DPPH method. The reaction occurred with and without lime juice catalyst, producing yields of 6.65% and 70.58%, respectively. The results of the antioxidant activity test suggest that Compound 1 carries substantially robust antioxidant activities, with IC50 of 0.99 ppm.
Eco-friendly synthesis of magnetite based on tea dregs (Fe3O4-TD) for methylene blue adsorbent from simulation waste Rahmayanti, Maya; Yahdiyani, Atika; Afifah, Ika Qurrotul
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.965

Abstract

Methylene blue is a popular dye used in the batik industry; however, it potentially causes environmental problems in view of the residual MB content in the liquid waste, which is difficult to naturally degrade. This study aimed to synthesize Fe3O4-TD using tea dregs from household waste and its application as an adsorbent for methylene blue dye. The synthesis was carried out using the reverse co-precipitation method with water as a solvent at room temperature. Fe3O4-TD characterization using FTIR, XRD, and PSA. The adsorption of methylene blue (MB) on Fe3O4-TD was studied at various pH MB, reaction time, and concentration MB to determine the kinetic model and MB adsorption isotherm on Fe3O4-TD and the interactions that occur between MB and Fe3O4-TD. FTIR spectra and X-Ray diffractogram showed that the magnetite formed in a pure state did not mix with other iron oxides. The crystal and particle size of Fe3O4-TD is 18.92 nm and 26.70 µm, respectively. MB adsorption on Fe3O4-TD occurred well at pH > 3 and followed the Ho' pseudo-second-order kinetics model and the Freundlich isotherm model. The interactions between MB and Fe3O4-TD through electrostatic interactions, hydrogen bonds, and phi-phi interactions.
A review of biomaterial as an adsorbent: From the bibliometric literature review, the definition of dyes and adsorbent, the adsorption phenomena and isotherm models, factors affecting the adsorption process, to the use of typha species waste as adsorbent N'diaye, Abdoulaye Demba; Kankou, Mohamed Sid' Ahmed; Hammouti, Belkheir; Nandiyanto, Asep Bayu Dani; Al Husaeni, Dwi Fitria
Communications in Science and Technology Vol 7 No 2 (2022)
Publisher : Komunitas Ilmuwan dan Profesional Muslim Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21924/cst.7.2.2022.977

Abstract

This paper presents a review of adsorption isotherms of some dyes from aqueous solutions by biomaterial. In this paper, we reported Typha waste as a model of biomaterial classified as a low-cost adsorbent. The paper also briefly discusses about the literature information from the definition of dyes and adsorbents, bibliometric analysis, adsorption phenomena, adsorption isotherm models, and factors affecting the adsorption, to the use of Typha species waste as a low-cost adsorbent. The operational parameters factors are explained in terms of pH, adsorbent dosage, contact time, and initial dye concentration that will affect the process of removing textile dye. The solution of pH turns out to be the most important condition in the adsorption process for anionic dye, a low pH value are preferable in contrast to cationic dye where the suitable pH value is high. For the adsorbent dose, the adsorption capacity increase along with the increment of adsorbent dosage due to the increase of theavailable amount of adsorption site. The contact time between the adsorbent and dye affects the efficiency of dye removal where a strong attraction force will shorten the time. As for the effect of dye initial concentration, increasing the initial concentration enhances the increment of adsorbent surface area to adsorb dyes. Several isotherm models are described. The Langmuir model is frequently used to evaluate the adsorption capacity of the Typha species waste as adsorbents. This review paper suggested that the accuracy level obtained from adsorption processes is greatly dependent on the successful modeling of adsorption isotherms. Typha biomaterial wastes can be considered as the new useful low-cost natural adsorbents for dye clean-up operations in aquatic systems.

Page 10 of 21 | Total Record : 209

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