Jurnal ILMU DASAR
Not a member yet
416 research outputs found
Sort by
Diversity of Echinoderms in Drini Beach Gunung Kidul, Yogyakarta
Full text linkResearch on the diversity of echinoderms at Drini Beach, Gunung Kidul, Yogyakarta has been conducted from December 2020 to July 2021. This study aimed to determine the Echinoderm diversity index. The method sampling technique used belt transect with determination by purposive sampling with three stations in the intertidal zone based on substrate variations. Station 1 had coral substrate type, station 2 had seagrass substrate type, and sand substrate type for station 3. The sample in this study was the species of Echinoderms found in the station area. After sampling, it obtained 7 species of Echinoderms consisting of 3 classes, classified into 4 orders, and 6 families. The diversity index at all stations is low, followed by a low evenness value and a high dominance value. The species Ophiocoma erinaceus was dominant at stations one and two, while the species Tripneustes gratilla was dominant at stations three. Moreover, the most common habitat for echinoderms is This is due to the availability of abundant food, laying places for echinoderms, and shelter to avoid predators. In addition, it is also supported by temperature, pH, salinity, strong currents, and a good depth for Echinoderm habita
Analysis of the Death Risk of Covid-19 Patients Using Extended Cox model
Full text linkGlobally, in 2021, there were 170,051,718 COVID-19 cases and 3,540,437 patients who died. The high mortality rate of patients infected with COVID-19 gives an idea to research the analysis of the factors that influence the death of Covid-19 patients. The data used in this study is data on Covid-19 patients obtained from the Mexican Government, with response variables namely time and status and predictor variables, namely patient laboratory results in the form of a history of illness that has been suffered by Covid-19 patients so that they adopt the extended model to evaluate the data. The data in this study are heterogeneous and large in number so that data clustering is carried out into 3 clusters, namely low emergency clusters, medium emergency clusters and high emergency clusters using K-means clustering. Because the study could not find the factors that influence the death of Covid-19 patients, two clusters were chosen, namely the medium emergency cluster and the high emergency cluster. So that the factors that influence the death of Covid-19 patients in the medium emergency cluster are sorted by the highest hazard ratio, namely pneumonia, old age, renal chronic, diabetes, Chronic Obstructive Pulmonary Disease (COPD), immune system, hypertension, cardiovascular, obesity, gender, and asthma. In the high emergency cluster, sorted by the highest hazard ratio is the immune system, renal chronic, cardiovascular, COPD, tobacco, hypertension, obesity, gender, and pneumonia
Antioxidant Assay and Total Flavonoid Determination of Ethanolic Extract of Walnut (Canarium indicum L.) Leaves and Its Fractions
Full text linkAntioxidants are compounds that inhibit free radicals. Many plants have antioxidant activity because they contain antioxidant compounds such as flavonoids. This study aimed to evaluate the antioxidant activity, phytochemical contents, total flavonoid content and to establish the relationship of total flavonoid content and antioxidant activity of extract and fractions of walnut (Canarium indicum L.) leaves. Antioxidant activity of ethanolic extract, n-hexane fraction, ethyl acetate fraction, and ethanolic-water fraction of walnut leaves was examined by using the DPPH method and determination of total flavonoid content was determined spectrophotometrically. The results showed that antioxidant activity of ethanolic extract, n-hexane fraction, ethyl acetate fraction, and ethanolic-water fraction based were 25.294 ± 0.055; 175.245 ± 0.4999; 20.135 ± 0.009; and 28.806 ± 0.0424 μg/ml, respectively. The phytochemical content of ethanol extract of walnut leaves are saponins, flavonoids, tannins, and polyphenols. The total flavonoid content of ethanolic extract, n-hexane fraction, ethyl acetate fraction and ethanolic-water fraction were 2.624 ± 0.012; 0.499 ± 0.023; 3.846 ± 0.006; and 1.596 ± 0.006 gram quercetin equivalent/gram extract, respectively. Correlation between antioxidant activity and total flavonoid content revealed that 63.2 % of antioxidant activity was influenced by the presence of flavonoid compounds
Microcellulose from Betel Husk Fiber as Filler in Bioplastic: Microsellulose from Betel Nut Husk Fiber As Filler in Bioplastic
Full text linkBetel nut husk fiber has a reasonably high cellulose content. Meanwhile, bioplastics nowadays are mostly made of Poly Vinyl Alcohol (PVA), with one of its limitations being tensile strength and other properties regarding mechanical. Thus, this study aims to isolate microcellulose from areca nut fiber and use the fiber as a filler in bioplastic, where cellulose is combined with PVA. The intention is to understand the effect of adding microcellulose from betel nut fibers on the properties, including the biodegradability of PVA-based bioplastic films. This research has three steps: isolating cellulose from betel nut peel fibers by delignification, pulping, and bleaching. The next step is hydrolysis to obtain microcellulose. The last is the preparation of bioplastic films using the solution casting method, with five different ratios of microcellulose content in the bioplastic. The cellulose characterization from FTIR spectra shows the absorption of several peaks, such as O-H, C-H, and C-O functional groups. The mechanical testing results on the variation of bioplastic show that the bioplastic with the best characteristics was PL5, which has the highest microcellulose content, 8 MPa and 10.2% for tensile strength and elongation, respectively. The biodegradation test for bioplastic variation (PL5) was 82% within eight weeks, while in Indonesian National Standard (SNI) number 7188.7:2016, it is 100% within 60 days
The Robust Model Predictive Control Design for Linear Interconnected Systems
Full text linkIn this paper, we discuss the design of robust model predictive control for linear interconnected systems by several constraints. Linear interconnected system is a complex systems which consist of several subsystems and the dynamic of subsystem is influenced by the states or outputs of the other subsystems. The systems are controlled by formulating and applying the model predictive control on each subsystems. We formulate the optimization problem that minimize the cost function for each subsystems. The optimization problem is solved by gradient method to get the minimum cost function. Numerical simulation was conducted to show the effectiveness and performance of robust model predictive control. Based on the results of the numerical simulation and test the robustness, it can be shown that the robust model predictive control is effective to control the linear interconnected systems
The Diversity of Butterfly (Lepidoptera: Rhopalocera) in Triagle of Lakes Lumajang, East Java
Full text linkThe triangle of lakes which are Bedali Lake, Klakah Lake and Pakis Lake area serves as a sanctuary for many wildlife including butterflies. Butterfly spesies at Ranu Bedali has ecological functions as herbivors, pollination, detrivor, as well as bioindicator of ecosystem changes. The objective of this study was to identify the diversity of butterflies in triangle of lakes Lumajang Regency. The sampling technique used was Abundance Point Index Method. All spesies captured were identified and analyzed. The results showed that the composition of butterflies have been obtained consisted of 4 families and 37 species. The most abundant family with a huge of species is Nymphalidae while the least family is Lycaenidea. The diversity index (H’) for the butterflies in Pakis Lake, Klakah Lake and Bedali Lake were 2.56; 2.73 and 2.76 respectively. The evenness index (E) for the butterflies in Pakis Lake, Klakah Lake and Bedali Lake were 0.43; 0.47 and 0.48 respectively. Among the butterlies, it found Troides helena was classified at the list of Appendix I and Appendix II CITES (Convention on International Trade in Endangered)
Species Diversity of Bivalves and Gastropods at the Tanjung Rising Coastal, Bangka Belitung Island
Full text linkTanjung Rising Coastal, located in Dendang Village, Bangka Belitung Islands, has a large variety of substrates and organisms. One of the types of marine life studied is the Mollusk Phylum including the Bivalve and Gastropod classes. To find out the diversity of Bivalvia and Gastropoda, this study was carried out on Tanjung Rising Coastal, Bangka Belitung Islands. The study was conducted in December 2020-August 2021, using belt transect method with purposive sampling technique. Samples were collected at station 1 with a sandy substrate and station 2 with a muddy substrate. The results of this study found 1,372 individuals from the Bivalvia class consisting of 7 families and 12 species, while from the Gastropod class yielded 2,630 individuals consisting of 5 families and 7 species. The diversity and evenness index at both stations is relatively low which means that there are species that dominate, because both stations have good habitats for the dominating species. In addition, temperature, pH, salinity, depth, and strong currents showed good values for Bivalvia and Gastropoda habitat. In summary, Tanjung Rising Beach is still a good habitat for invertebrate animals, especially Bivalvia and Gastropoda
