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44 results on '"Wahyudi, Tatang"'

3. The effects of carbon fiber surface treatment by oxidation process for enhanced mechanical properties of carbon fiber/epoxy composites for biomedical application

Author

Roseno, Seto, primary, Ammarullah, Muhammad Imam, additional, Rohman, Saeful, additional, Kurniawati, Fitri, additional, Wahyudi, Tatang, additional, Wargadipura, Agus Hadi Santosa, additional, Masmui, Masmui, additional, Budiyanto, Dwi, additional, Effendi, Mochammad Dachyar, additional, Wahyudin, Wahyudin, additional, Kalembang, Eryanti, additional, Hernawan, Hernawan, additional, Subari, Subari, additional, Habibie, Sudirman, additional, Simanjuntak, Tarida Priskila Hasian, additional, Santoso, Heru, additional, Ahmad, Ahmad, additional, and Juwono, Ariadne Laksmidevi, additional

Published
2024
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4. An optimized chitosan/alginate-based microencapsulation of lime peel essential oil and its application as an antibacterial textile.

Author

Indriyani, Nastiti Nur, Al-Anshori, Jamaludin, Wahyudi, Tatang, Nurzaman, Mohamad, Nurjanah, Sarifah, Permadi, Nandang, and Julaeha, Euis

Subjects
ESSENTIAL oils, MICROENCAPSULATION, ESCHERICHIA coli, SODIUM tripolyphosphate, ALGINATES, CHITOSAN, SODIUM phosphates, CHITIN, TERPENES
Abstract

A functional textile immobilized by microcapsules of the lime peel essential oils of C. aurantifolia (LPEO) was prepared and characterized. A varied amount of Chitosan/Alginate (CH/AG) ratios, followed by a mass of LPEO and concentration of sodium tripolyphosphate (STPP) crosslinker, was optimized sequentially to coacervate LPEO using a Tween 80 emulsifier. An antibacterial assay against both Gram-positive and Gram-negative bacteria was further evaluated for the embedded microcapsules. The LPEO (0.2 g) was effectively coacervated by CH/AG (5:3) crosslinked by 2% of STTP to give a yield, oil content (OC), and encapsulation efficiency (EE) of 53.45 ± 2.16%, 65.08 ± 2.60% and 85.04 ± 0.70% respectively. A rough spherical shape of LPEO microcapsules was homogeneously observed with an average particle size of 0.757 mm. An Avrami's kinetic model revealed the release mechanism of the core following zero-order kinetics (k = 1.11 ± 0.13 × 10−9 s−1, Ea = 70.21 kJ/mol). The LPEO microcapsules demonstrated good thermal stability up to 122 °C and maintained 38% OC at ambient temperature for four weeks. A 70.34 ± 4.16% of the LPEO microcapsules were successfully overlaid onto the gauze with citric acid binder and sodium phosphate catalyst. Overall, the immobilized microcapsules exhibited strong inhibition against S. aureus and moderate against S. epidermidis, E. coli, and K. pneumonia. [ABSTRACT FROM AUTHOR]

Published
2024
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7. Effect of roasting and injection of H2O2 on recovery of gold cyanidation.

Author

Oediyani, Soesaptri, Triana, Tiara, Sidik, Giar Maulana, and Wahyudi, Tatang

Subjects
SULFIDE minerals, ROASTING (Metallurgy), GOLD ores, SULFIDE ores, GOLD, ROASTING (Cooking)
Abstract

Gold ores in Tasikmalaya region, West Java, are commonly found in the form of sulfide ores. Sulfide minerals generally include chalcopyrite, pyrite, galena, sphalerite, and chalcocite. These sulfide minerals would obstruct the extraction of gold through cyanidation process. According to XRF test, it is obtained that Tasikmalaya ores contain 83.68% of silica. Cyanidation of gold was carried out in three conditions. The first condition was done by roasting the gold ores before cyanidation. The second one was conducted by adding H2O2 and the last one by doing cyanidation process without roasting and H2O2 addition. The cyanidation process was carried out along 48 hours with cyanide concentrations varied of 300, 500, and 700 ppm. The highest gold recovery of 95.86% was achieved through H2O2 addition with 700 ppm of cyanide concentration. [ABSTRACT FROM AUTHOR]

Published
2023
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43. An optimized chitosan/alginate-based microencapsulation of lime peel essential oil and its application as an antibacterial textile.

Author

Indriyani NN, Al-Anshori J, Wahyudi T, Nurzaman M, Nurjanah S, Permadi N, and Julaeha E

Subjects
Calcium Compounds chemistry, Drug Compounding, Microbial Sensitivity Tests, Escherichia coli drug effects, Polyphosphates chemistry, Polyphosphates pharmacology, Particle Size, Chitosan chemistry, Chitosan pharmacology, Alginates chemistry, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Textiles, Oils, Volatile chemistry, Oils, Volatile pharmacology, Capsules
Abstract

A functional textile immobilized by microcapsules of the lime peel essential oils of C. aurantifolia (LPEO) was prepared and characterized. A varied amount of Chitosan/Alginate (CH/AG) ratios, followed by a mass of LPEO and concentration of sodium tripolyphosphate (STPP) crosslinker, was optimized sequentially to coacervate LPEO using a Tween 80 emulsifier. An antibacterial assay against both Gram-positive and Gram-negative bacteria was further evaluated for the embedded microcapsules. The LPEO (0.2 g) was effectively coacervated by CH/AG (5:3) crosslinked by 2% of STTP to give a yield, oil content (OC), and encapsulation efficiency (EE) of 53.45 ± 2.16%, 65.08 ± 2.60% and 85.04 ± 0.70% respectively. A rough spherical shape of LPEO microcapsules was homogeneously observed with an average particle size of 0.757 mm. An Avrami's kinetic model revealed the release mechanism of the core following zero-order kinetics ( k  = 1.11 ± 0.13 × 10 -9 s -1 , Ea = 70.21 kJ/mol). The LPEO microcapsules demonstrated good thermal stability up to 122 °C and maintained 38% OC at ambient temperature for four weeks. A 70.34 ± 4.16% of the LPEO microcapsules were successfully overlaid onto the gauze with citric acid binder and sodium phosphate catalyst. Overall, the immobilized microcapsules exhibited strong inhibition against S. aureus and moderate against S. epidermidis, E. coli, and K. pneumonia .

Published
2024
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44. Microencapsulation of Citrus aurantifolia essential oil with the optimized CaCl 2 crosslinker and its antibacterial study for cosmetic textiles.

Author

Pratiwi L, Eddy DR, Al Anshori J, Harja A, Wahyudi T, Mulyawan AS, and Julaeha E

Abstract

A functional fabric immobilized by the microcapsules of C. aurantifolia lime essential oil (LO) was prepared and characterized. A varied amount of CaCl 2 crosslinker was optimized to coacervate LO using alginate-gelatin biopolymers and Tween 80 emulsifier. A further evaluation of the immobilized LO microcapsules for the antibacterial effect against both Gram-positive and Gram-negative bacteria was conducted. The optimized alginate/gelatin-based microcapsules were effectively crosslinked by 15% CaCl 2 with an yield, oil content (OC), and encapsulation efficiency (EE) of 39.91 ± 3.10%, 78.33 ± 7.53%, and 90.27 ± 5.84%, respectively. A spherical shape of LO microcapsules was homogeneously found with an average particle size of 1.394 μm. A first-order kinetics mechanism for the release of LO out of the microcapsules was modeled by Avrami's kinetic equation ( k = 1.60 ± 3.68 × 10 -5 s -1 ). The LO microcapsules demonstrated good thermal stability up to 100 °C and maintained 51.07% OC and 43.56% EE at ambient temperature for three weeks. Using a pad dry method and citric acid binder, LO microcapsules were successfully immobilized on a cloth with a % add on 30.60 ± 1.80%. The LO microcapsules and the immobilized one exhibited a moderate ZoI of bacterial growth for Gram-positive S. aureus and S. epidermidis as well as Gram-negative E. coli and K. pneumonia . Further washing test toward the functional fabric showed that the LO microcapsules incorporated into the fabric were resistant to five cycles of normal washing with a mass reduction of 22.01 ± 1.69%., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Published
2022
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