Jurnal Teknosains
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Coloration study heat-cured polymer materials for denture base
No full textThe color of denture base material is important in dentistry to achieve a natural gingival aesthetic. No universal standard for denture base color, due to it difficult for dentists and dental laboratory technicians to achieve consistent results. This study proposes a method for identifying the color of artificial gums made from heated cure polymers with coloring agents. This study also examined the effect adding color agent on the hardness of denture base material and the effect of artificial saliva immersion on coloring. New coloring agents, namely pink (P), red (M), and purple (U), were added to create new colors in this study. Seven specimens from light to dark colors were made. The resulting specimens were photographed and analyzed using Adobe Photoshop software to obtain the L*, a*, and b* values for each specimen, which were then analyzed using the CIELAB formula. The results of the material hardness test showed a significant change between the immersion and non-immersion groups (p-value 0.000.05). In materials without added color, the hardness value is 85.3 - 86.3 HSD, while in materials with added color, the hardness value increases to 85.5 - 87.7 HSD. The results of the saliva immersion test showed changes in the range of 2.51 - 5.98 for 10 days of immersion and 0.85 - 4.22 for 20 days of immersion. Based on these results, most of the color changes are still below the clinical acceptance threshold of less than 4.1. Therefore, it can be concluded that the color changes that occur after soaking are still clinically acceptable
Potential of baroma rice as anti-cancer food candidate via cell cycle arrest and apoptosis
No full textCancer is a condition where the body's cells continue to divide without control. Often, this cancer is detected when it has entered an advanced stage, making it difficult to treat. Rice is a staple food widely used by more than half of Indonesia's population. The position of rice, which is a staple food, can be used as a prospective treatment to overcome the increasing number of cancer cases, especially in cases of colon cancer. Rice is reported to have many beneficial chemical contents. In cytotoxicity testing using WiDr colon cancer cells, the IC50 of the ethanolic extract of baroma rice is 316.01µg/ml. Stovetop cooked baroma rice showed an IC50 value of 672 µg/ml, while magic com cooked rice showed an IC50 value of 1232 µg/ml. Raw and stove-cooked baroma rice extracts are not strong enough to trigger apoptosis in cancer cells and can arrest the cell cycle at the G1 stage. This research shows that baroma rice extract has cytotoxic properties against WiDr colon cancer cells and various other evidence regarding the advantages of baroma rice. It is hoped that this rice can become a food that can prevent colon cancer
Characterization and mechanical properties of biocomposite of cantula fiber reinforced nano-ha/magnesium/shellac for bone screw material
No full textAccidents are a major cause of fractures in Indonesia. One of treatments for fractures is bone screws with support plates that are placed on broken bone. Currently, many biomaterials for bone screws are being developed which have biodegradable properties so that post-operative bone healing is not required. The purpose of this study was to determine the effect of cantula fiber addition on tensile strength, wear rate, and crystallinity of nano-HA/magnesium/Shellac biocomposite for bone screw materials. Nano-HA/magnesium/Shellac/cantula fiber materials were mixed using a blender. The material was mixed with a magnesium/hydroxyapatite ratio of 70/30 and cantula fiber is added with variations of 0%, 10%, 20% and 30% of total volume. After that, the material mixture was compacted with a pressure of 300 MPa for 10 minutes. Then the sintering process was carried out at a temperature of 140 ̊C for two hours. The results showed that the highest tensile strength value was 7.86 MPa at 30% variation. The lowest wear rate was 0.31 x 10-3 mm3/Nm at 30% variation. The highhest crystallinity in XRD observations was obtained at 30% variation, which was 79.65%
Performance of moving bed biofilm and lamella clarifier hybrid technology to improve hospital wastewater quality
No full textSurface water pollution caused by the discharge of domestic wastewater, including that from hospitals, is a serious issue that threatens public health and environmental quality. Hospital wastewater typically contains high concentrations of organic matter (COD, BOD), suspended solids (TSS), and pathogenic compounds that may exceed the quality standards set by the Ministry of Environment and Forestry, as outlined in Regulation No. 68 of 2016. This study aims to evaluate the performance of a combination of a Moving Bed Biofilm Reactor (MBBR) using Kaldness K1 media and a Lamella Clarifier in reducing COD, BOD, and TSS levels, as well as stabilizing the effluent pH of hospital wastewater at the laboratory scale. The research employed an experimental approach, utilizing a laboratory wastewater treatment plant design comprising MBBR and Lamella Clarifier units. Wastewater samples were collected by grab sampling from the hospital treatment plant inlet, then diluted to varying concentrations of 20%, 30%, and 50%, and subjected to a 24-hour retention time. The analyzed parameters included COD, BOD, TSS, and pH. The treatment results were statistically analyzed using a paired t-test to assess the significance of concentration reductions before and after treatment. The results indicated that the combination of these two units achieved average reductions of BOD by 56%, COD by 34%, and TSS by 53%, with effluent pH between 7.3 and 7.6, meeting quality standards. Statistical analysis revealed significant differences (p < 0.05) between inlet and outlet conditions, indicating the system's effectiveness. Therefore, the integration of MBBR and Lamella Clarifier is considered a viable solution for efficient, stable, and regulation-compliant hospital wastewater treatment
Effect of garlic extract as a natural preservative based on protein profile of red snapper
No full textRed snapper (Lutjanus bitaeniatus) is a source of animal protein with a high-water content, making it prone to spoilage. Spoilage can be prevented through preservation. Garlic can be used as a natural preservative for fish because it contains antibacterial substances, including allicin, which plays a role in inhibiting and killing spoilage bacteria, as well as other antimicrobial compounds such as alkaloids, flavonoids, saponins, and tannins. This study aims to determine the effect of garlic extract as a natural preservative on the protein profile of red snapper. The research design was divided into five parts: fresh red snapper stored for 24 hours without soaking, and three parts soaked in garlic extract at concentrations of 5%, 10%, and 20%, respectively. This type of research was experimental. The research method was the preparation of garlic extract at concentrations of 5%, 10%, and 20%. Protein concentration was calculated using the Bradford method, followed by SDS-PAGE to separate proteins based on their molecular weight. The SDS-PAGE results were analyzed using the GelAnalyzer 19.1 application to calculate the molecular weight of the proteins and the protein profiles of the treatments compared to fresh fish. The results showed that the highest protein concentration was found in the 5% garlic extract treatment compared to the 10% and 15% concentrations. The protein profiles of fresh snapper and the 5% garlic extract treatment were not significantly different from fresh red snapper, with 13 protein bands (9 major bands and four minor bands). In contrast, fresh red snapper had 16 protein bands (13 major and three minor bands). This study concludes that garlic extract immersion treatment can be used as a natural preservative, with the optimal concentration being 5% garlic extract
Production and characterization of lactic acid bacteria biofilms synthesized using tofu wastewater
No full textBiofilms serve to protect microbes from environmental conditions. Biofilms produced by lactic acid bacteria (LAB) can even inhibit the growth of pathogens. Medium de Man Ragosa Sharpe (MRS) is a specific medium for LAB growth and biofilm formation; however, it is not effective on an industrial scale due to its high cost. Tofu wastewater serves as an alternative medium because it contains complete nutrients that support the formation of LAB biofilms. This study aimed to determine the effect of C and N formulation in tofu wastewater on the production and characterisation of biofilms produced by four Lactobacillus (LAB) strains, including Enterococcus casseliflavus F4IS5, E. casseliflavus F14IS5, and E. casseliflavus F14IS6. Glucose and ammonium sulfate were added to the tofu wastewater as carbon and nitrogen sources, respectively. The biofilm-forming ability of LAB was tested by the biofilm assay method. The LAB biofilm characteristics were tested based on adhesion, while the exopolysaccharide concentration, a component of the biofilm, was analysed using the dry weight method. The inhibitory activity of LAB biofilms against the growth of pathogenic bacteria, specifically Escherichia coli and Staphylococcus aureus, was tested using the microplate method. The highest LAB biofilm production was obtained from the E. casseliflavus F6IS4 isolate in a tofu wastewater medium supplemented with 2% glucose and 1% ammonium sulfate, with an incubation time of 48 hours. The biofilm produced was categorised as a strong biofilm, which also exhibited strong adhesion; the separate cells accounted for only 19.25%. Besides, the EPS production by the strain was 63.4%. The biofilm of E. casseliflavus F6IS4 in tofu wastewater, supplemented with 2% glucose and 1% ammonium sulfate, also exhibited the highest inhibitory activity against E. coli and S. aureus, at 2.7% and 2.1%, respectively
Optimizing the density of ultrafine bubbles fluid by time and production volume in a closed-loop system
No full textUltrafine bubbles (UFBs) play a crucial role as catalysts in water treatment, pharmaceuticals, biomedical engineering, and industrial processes, particularly those involving heat transfer mechanisms. Several researchers in Indonesia have explored ultrafine bubble fluids' potential as a heat transfer medium in passive cooling system models. In this context, changes in the density of ultrafine bubble fluids serve as the primary driver for flow. Since ultrafine bubbles increase in diameter when heated, examining an optimal production model is essential to ensure their availability in the flow. This study aims to optimize the production of ultrafine bubble fluids with the lowest possible density compared to the base fluid (reference). The research investigates the effect of production time and volume variations on ultrafine bubble density in a closed-loop system. Production times of 30, 60, 90, 120, 150, and 180 minutes are tested across tank volumes of 20, 40, 50, and 60 liters. The closed-loop production model utilizes hydrodynamic cavitation to maintain continuous fluid flow, with sample collection occurring at 15-minute intervals after the initial production time to allow for stable bubble size. Observations and statistical analysis using the Response Surface Method (RSM) reveal a nonlinear relationship between production time and ultrafine bubble fluid density. The optimal density is achieved with a production time of 60 minutes for a 40-liter volume. Additionally, this closed-loop model increases the temperature of the ultrafine bubble fluid to 54.3 °C in a 20-liter volume. Heat accumulation occurs due to the continuous pump-driven flow without additional cooling systems
Noise analysis of grinding machine in the material cutting process
No full textThe handheld grinding machine used for cutting materials has generated noise that may affect the operator and individuals nearby. The noise produced by this machine needs to be analyzed to prevent potential health impacts. This study aims to measure the noise levels the handheld grinding machine generates while cutting materials such as ceramic, metal, and natural stone. Noise measurements were taken at the noise source and distances of 2 meters, 3 meters, and 4 meters from the source. A sound level meter was used for the noise measurements. The study's results indicate that the type of material being cut using the handheld grinder does not significantly affect the noise level produced. The highest noise level was recorded when cutting the plate, with an equivalent continuous sound level (Leq) of 91.6 dB at the source. The lowest noise level was recorded when cutting ceramic material, with a Leq of 89.7 dB. Statistical tests on the distance and measurement locations at 2 meters, 3 meters, and 4 meters from the source showed that the distance does not significantly affect the noise level. At distances of 2 meters and 3 meters, the average Leq for all materials was the same, ata 94.2 dB, while at 4 meters, the average Leq was slightly lower, at 93.9 dB
Effect of extraction, ratio, and solvent concentration on total flavonoid content and antioxidant activit of singkel (premna serratifolia linn.) using dpph method
No full textSingkel (Premna serratifolia Linn.) is a medicinal plant commonly found in tropical regions, including Indonesia, which contains flavonoids, alkaloids, polyphenols, and triterpenoids. Flavonoids in singkel leaves act as antioxidants that can prevent oxidative stress, which is a causative factor of degenerative and chronic diseases such as cancer, arthritis, and cardiovascular diseases. This study aims to determine the effects of total flavonoid content and IC50 values in singkel leaves based on extraction methods, solvent concentration, and the ratio of extract to solvent. The methods used include maceration, soxhlet extraction, and Microwave-Assisted Extraction (MAE), with ethanol solvent concentrations of 60%, 70%, 80%, and 96%, and extract-to-solvent ratios of 1:10, 1:20, and 1:30. Antioxidant activity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method with UV-Vis spectrophotometry. The results showed that the soxhlet extraction method yielded the highest total flavonoid content of 24.56±1.81 mgQE/g with an IC50 value of 20.31±1.58 μg/mL. The 96% solvent concentration provided the best results with a total flavonoid content of 26.12±0.06 mgQE/g and an IC50 value of 15.51±2.17 μg/mL. In the solvent ratio testing, the 1:20 ratio showed the highest total flavonoid content of 19.37±0.5 mgQE/g, while the 1:10 ratio provided the best IC50 value of 11.99±1.02 μg/mL. In conclusion, the extraction method, solvent concentration, and solvent ratio significantly affect the flavonoid content and antioxidant activity of singkel leaves
Numerical simulation of layer thickness optimization in perovskite solar cells for enhanced power conversion efficiency
No full textPerovskite solar cells (PSCs) have gained significant attention due to their remarkable power conversion efficiency (PCE) and potential for low-cost, scalable production. Despite this progress, further efficiency enhancement requires systematic optimization of device architecture, particularly the thickness of functional layers. This study presents a numerical simulation using the OGMANANO simulation platform to investigate the influence of layer thickness variation, specifically in the perovskite absorber layer, electron transport layer (ETL), and hole transport layer (HTL), on the performance of planar PSCs. The simulation models a typical n-i-p structured device under standard AM1.5G illumination, evaluating key photovoltaic parameters such as short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and overall PCE. Results indicate that the optimal absorber thickness lies in the 500–600 nm range, with a peak efficiency of 22.7% achieved at 550 nm. Furthermore, ETL and HTL show optimal performance at 50 and 60 nm, respectively, minimizing recombination losses and enhancing charge transport. The study concludes that precise layer thickness control is critical for maximizing PSC efficiency. The use of OGMANANO proved effective in simulating multilayer perovskite structures, providing a reliable tool for pre-fabrication optimization in advanced solar cell design.