Jurnal ILMU DASAR
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Growth Pattern and Degradation Activity of Caffeine-degrading Bacteria Consortium
Full text linkCaffeine-degrading bacteria can be used as agents to degrade caffeine, thereby reducing the concentration of caffeine in organic waste. The decomposition process is carried out by a single bacterium or a consortium of bacteria. Caffeine-degrading bacteria from Sempol, Bondowoso, namely Acinetobacter gerneri KAFS 47, Paracoccus denitrificans KAFS 16 and Pseudomonas plecoglossicida KAFS 34, could be used as a bacterial consortium to promote caffeine degradation. The aim of this study was to analyze associations between caffeine-degrading bacteria isolates, bacterial resistance to antibiotics, growth patterns, and caffeine degradation of a consortium of caffeine-degrading bacteria, and the correlation of bacterial growth with caffeine degradation. The research method used is an analysis of the association between isolates, the development of bacterial consortium growth patterns, and their analysis based on antibiotic resistance, patterning of caffeine degradation, and correlation test (Pearson) of bacterial growth with caffeine degradation. The result of the association test between bacteria showed that the three bacteria had the potential to be used as a consortium of caffeine-degrading bacteria. A. Gerneri, P. denitrificans, and P. plecoglossicida were resistant to the antibiotic cefixime (100 ppm), erythromycin (50 ppm), lincomycin (50 ppm), metronidazole (50 ppm), and sanprima (50 ppm). The growth of the bacterial consortium (54.779 CFU/mL) was higher than that of P. plecoglossicida (49.277 CFU/mL) and lower than that of A. gerneri (93.481 CFU/mL) and P. denitrificans (84.940 CFU/mL) in incubation time of 4 days. However, the consortium of bacteria and P. plecoglossicida were able to degrade caffeine 24 hours faster (3 days) than the other two single isolates (4 days) to degrade 2.5 g/L caffeine in media to 0%. Bacterial growth due to caffeine degradation has a perfect correlation value (>0. 950) and is negative
The Application of Cows Rumen for Electricity Generation Through The Implementation of A Ceramic-Based Microbial Fuel Cell System
Full text linkThe growth in population is not adequately matched by the corresponding increase in energy demand. The imperative for prioritizing the exploration of alternative energy sources that possess attributes of safety, affordability, and ample access to raw materials cannot be overstated. An energy source with significant potential is a microbial fuel cell (MFC)-based energy source. This study aims to investigate the utilization of cow rumen as a substrate and source of nutrition in the bioenergy system of microbial fuel cells (MFCs). The present study aims to investigate the impact of substrate concentration and bacterial incubation duration derived from bovine rumen bacteria on the attainment of optimal power density. The research employed a Dual Chamber Microbial Fuel Cell (MFC) device using a Proton Exchange Membrane (PEM) constructed from ceramic materials. Daily observations were conducted over a period of 30 days. The performance of MFC was assessed utilizing the polarization technique. The findings indicated that altering the proportion of bovine rumen bacterial substrates and the duration of bacterial incubation had an impact on the power density seen in the Microbial Fuel Cell (MFC) system. The optimal conditions were attained when the substrate concentration reached 3640 ppm and after 7 days, resulting in a maximum power density of 864 mW/m2
Variations of Coconut Shell, Rice Husk, and Bagasse as an Alternative of Briquettes Materials
Full text linkThe current energy condition is getting thinner meanwhile people's daily lives still use a lot of energy derived from fossil fuels so that its use is increasing with limited availability. An alternative to reduce the use of fossil energy is by utilizing waste biomass as an energy source one of them is briquetts. This study aims to analyze the characteristics of briquettes from a variety of briquette mixtures made from coconut shells, rice husks, and bagasse. The method used is survey and experimental. The survey of sampling coconut shells was carried out in the Seberang Ulu I area, rice husks in the Pegayut area, and bagasse was obtained at the ice cane traders in the Seberang Ulu I area. The data obtained were presented in graphical form and analyzed descriptively. The results obtained are the water content in the variation of the combination of briquette-making materials ranging from 4.23 - 5.13%, ash content of 7.6 - 7.86%, the density value obtained is 0.55 - 0.59 g/cm3, the compressive strength value is 25.67 - 37.33 kg/cm2, and the calorific value is 4756 - 4865 cal/gr. The results showed there is not significant differences in moisture content, ash content, and compressive strength, while the density and calorific value showed significant differences
Identification of Rossby Atmosphere-Tropical Cyclone in Eastern Indonesian Waters
Full text linkRecent research has revealed that tropical cyclones can develop over eastern Indonesian waters influenced by marine heatwaves and Rossby waves in the atmosphere. However, there is no study documenting tropical cyclones that occur in conjunction with atmospheric Rossby waves (Rossby Atmospheric-Tropical Cyclones) and their association with increased sea surface temperatures in eastern Indonesian waters. This study aims to document the influence of Rossby waves in the atmosphere on the formation of tropical cyclones around the Indonesian region using 5 case studies in 2017-2022, namely: December 2017, January 2020, December 2020, December 2021, and April 2022. This study uses wind data, sea surface temperature, specific humidity, and temperature (2m) obtained from the European Re-Analysis (ERA5) with a temporal and spatial resolution of one hour and 0.25°×0.25°. The identification of Rossby waves is based on the Rossby index issued by the North Carolina Institute for Climate Studies (NCICS). In this study, the Rossby Atmosphere-Tropical Cyclone is grouped into three phases, namely: early phase, mature phase, and late phase, using composite and statistical methods to calculate anomalies. The results showed that in the early phase, the existence of Rossby waves was shown by two twin vortices over eastern Indonesia, which was supported by high specific humidity, warming sea surface temperature (>+0.4°C), and higher surface temperature (>+0.3°C) over Timor. In the mature phase, the twin vortices over eastern waters transformed into a tropical cyclone over the Philippines. In the final phase, specific humidity decreases, sea surface temperature cools (<-0.3°C), and surface temperature decreases (<-0.3°C). The results also prove the crucial role of Timor waters in forming Rossby waves that can grow into tropical cyclones around Indonesia
Early Detection of Microplastic Contamination in Fishes In The Sukamade Shoreline, Meru Betiri National Park
No full textMicroplastics (< 5 mm) have the potential to be a threat to organisms. However, the study of microplastic contamination in conservation areas, especially in Indonesia, is still limited. The Sukamade is a conservation area that is potentially contaminated by microplastic. This study aims to detect microplastic contamination in fish caught in the Sukamade shoreline as an early warning of the potential threat to biodiversity. The study was conducted from September to December 2022. The methods used include: 1). Fish sampling, 2). Dissection and removal of the gills and gastrointestinal tract; 3). Microplastic characterization based on sizes, shapes, and colors; 4). Data analysis. This is the first report that 451 microplastic particles were detected in four fish caught from the Sukamade shoreline: two individuals of Senangin fish (Eleutheronema sp.), one individual of Lemuru fish (Sardinella sp.), and one individual of Lowang totol fish (Trachinotus sp.). The presence of microplastic in the gastrointestinal tract of fishes shows the possibility of microplastic translocation in tissue and another tropic level, causing health problems in organisms and the community as a constituent of biodiversity
Diversity Species and Structure of Mangrove Vegetation in Conservation Forest and Angke Nature Park North Jakarta
Full text linkMangrove is important life support ecosystems in coastal and marine areas that have bio-ecological and socio-economic functions. Mangroves are found in tidal areas that have the ability to grow in salty waters and have a role as a barrier to abrasion. Mangrove plants have special adaptability to the environment such as adaptation to low oxygen levels, high salinity and less stable soils. Indonesia has the largest mangrove ecosystem and the highest biodiversity in the world. This study aims to determine the index of diversity and structure of mangrove communities in Hutan Lindung Angke-Kapuk (HLAK) and Taman Wisata Angke (TWA) Angke-Kapuk which is divided into 11 points. The research was carried out on November 15 to 30, 2021 using purposive sampling techniques based on the representation element, which took 5% of the total area and the shape of a square plot with a size of 50x50 meters. The results showed that 11 family, 12 genus and 15 species of mangroves were found, the type was divided into 8 species of true mangroves and 7 species of mangroves followed. The extinction rate of mangrove species in HLAK and TWA Angke-Kapuk amounted to 1.25. The level of type similarity between research points in the HL Angke-Kapuk and TWA Angke Kapuk areas in 2020 and 2021, showed a slight change in the level of type similarity at each point. The dominant type of seedling and sapling tree level is the Avicennia marina type. Mangrove diversity index (H’) in the area of HLAK and TWA Angke Kapuk is 1.6
Antibacterial Test of Kedondong Hutan Leaf (Spondias pinnata) Against Salmonella typhi
Full text linkKedondong hutan (Spondias pinnata) is a plant belonging to the Anacardiaceae family, plant that grows a lot in the Sulawesi area, one of which is in the Poso area, Central Sulawesi. The surrounding community uses this plant as a traditional food preparation which is often called the "Arogo Onco" by the community. Kedondong hutan contains active compounds that have the potential as antibacterial, namely flavonoids, saponins and tannins. The purpose of this study was to determine the potential of forest kedondong leaves in inhibiting the growth of Salmonella typhi bacteria. The extraction process was done the decoctation method using aquadest and while the antibacterial test was done using the diffusion method against three bacterial strains namely Salmonella typhi BPE 127.1 MC, BPE 122.4 CCA and NCTC 786. The results showed that the leaf extract of kedondong hutan (Spondias pinnata) contained flavonoids, saponins and tannins with the results of the analysis of total flavonoids 1514,9 mgQE/g, saponins 0.613% and tannins 8,94 mgTA/g. The results of the antibacterial test showed the greatest inhibitory power at a concentration of 100%. Salmonella typhi BPE 127.1 MC, BPE 122.4 CCA, NCTC 786, was the inhibition zone 17.67±0.58 mm, 15.67±0.58 mm and 20.33±0.58 mm were included in the category of strong inhibition zone
Analysis of Propeller Selection for Unmanned Aircraft
Full text linkUnmanned aircraft are usually used to perform missions, for example surveillance missions. This mission is not always carried out in a suitable location. Researchers must ensure that the aircraft can take off properly. For this reason, runway distance greatly affects the performance of the aircraft. The aircraft can fail to take off due to the lack of thrust generated by the propeller. The propeller diameter size of each unmanned aircraft can differ from one another and this difference in propeller diameter causes a difference in thrust force. Therefore, it is very important to determine the right propeller diameter to be used on an unmanned aircraft that is adjusted to the runway distance. This propeller selection analysis is carried out using experimental methods, which is tool testing and simulation with Propeller Power Calculator software. The results of this study can be seen that a propeller with a larger diameter will produce a greater thrust force. The size of the diameter and pitch and the number of blades of a propeller can also affect the amount of thrust generated. This will be a consideration for choosing a propeller to be used on an unmanned aircraft. So that the selected propeller can be used optimally by reviewing the amount of thrust that is influenced by the amount of diameter
Interleukin-6 as an Indicator for Acute Toxicity of DBL2β-PfEMP1 Recombinant protein as a Peptide-based Malaria Vaccine Candidate
Full text linkMalaria caused by Plasmodium spp is an important health problem, and vaccination could be essential for disease prevention. One potential protein candidate is the Duffy binding-like 2β (DBL2β)-Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1). The protein is responsible for malaria pathogenesis by mediating binding to intercellular adhesion molecule-1 (ICAM-1), a receptor on the host cells. This study aimed to investigate the acute toxicity of the DBL2β-PfEMP1 recombinant protein as a basis for developing a peptide-based malaria vaccine based on body weight and interleukin-6 (IL-6) concentration. The study used male and female Wistar rats, which were divided into treatment and control groups after two weeks of acclimatization. Rats in the treatment group were injected with 750 µg DBL2β-PfEMP1 recombinant protein, and the control group was injected with NaCl 0.9%. Any indications of clinical toxicity symptoms were closely monitored within 4 hours of injection up to 24 hours. Observations were conducted daily for 14 days and included body weight and toxicity symptoms such as rising fur, tremors, salivation, diarrhea, weakness, draping, excitability, twitching, and death. Blood was collected on days 5, 7, and 14 for IL-6 examination using the ELISA method. Rats were euthanized on day 14. Data were analyzed using an ANOVA test. There was no significant weight loss as well as weight gain and toxicity symptoms during 14 days after treatment in all groups. There was an increase IL-6 levels on day 14 in all groups. However, statistical analysis did not show a significant difference between the control and treatment groups (p>0.05). This study showed that the DBL2β-PfEMP1 recombinant protein has no acute toxicity in Wistar rats, implying its safety and potential as a peptide-based malaria vaccine