Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam

Accumulation Heavy Metal on Shrimp White (Litopenaeus Vannamei) at the River Mouth of Ketahun, North Bengkulu

Rinda Fitri Handayani — 2024-11-20

Heavy metals are poisonous materials capable of causing damage to the normal aquatic organisms in the community around the Ketahun River estuary. The entry of heavy metals into the waters of the Ketahun River estuary is allegedly from various activities such as bathing, washing, toilet use, palm oil plantations, coal mining, and the disposal of gold mine waste. This is the background for conducting research to analyze the content of Hg, Cd, Pb, and As in Litopenaeus vannamei in the Ketahun River estuary. The determination of sampling locations was done using a purposive method, and the samples were tested using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The ecology of the river estuary was measured using a thermometer, pH meter, Dissolved Oxygen Meter, and Total Dissolved Solid Meter. The research results were analyzed using a descriptive qualitative method. According to the findings of the study, the metal content in Litopenaeus vannamei exceeds the quality standard with an analysis result of 0.2328 mg/kg, while the quality standard is 0.20 mg/kg, which has health implications. For sediment, the heavy metal that exceeds the quality standard is mercury at 0.5921 mg/kg, while the quality standard is 0.15 mg/kg. The ecology of the river estuary continues to be an ideal environment for living biota.

Comparison of Ordinal Logistic Regression and Geographically Weighted Ordinal Logistic Regression (GWOLR) in Predicting Stunting Prevalence among Indonesian Toddlers

Silfiana Lis Setyowati — 2024-12-09

Ordinal logistic regression is a type of logistic regression used for response variables with an ordinal scale, containing two or more categories with levels between them. This method is an extension of logistic regression where the observed response variable is ordinal with a clear order. It addresses spatial effects that can cause variance heterogeneity and improve parameter estimation accuracy compared to logistic regression. Geographically Weighted Regression (GWR) is a statistical analysis technique designed to account for spatial heterogeneity. GWOLR is an extension of OLS and GWR models that incorporates spatial elements into regression with categorical variables. This study compares the effectiveness of OLR and GWOLR in analyzing stunting prevalence in toddlers. Comparing OLR and GWOLR can help assess the spatial impact on stunting prevalence. This analysis could reveal that certain regions have a higher tendency for stunting prevalence, while others might have lower tendencies, thus helping in understanding regional disparities. Toddler height is a key indicator of health and nutrition in early growth. The prevalence of stunting for toddlers, according to WHO, is categorized into four levels: low, moderate, high, and very high. The Ordinal Logistic Regression model is better suited for modeling toddler stunting prevalence in Indonesia than the GWORL model. The Ordinal Logistic Regression model and the GWOLR both have a classification accuracy of 85.7%, but the OLR model has a lower AIC value. The GWOLR model is not suitable for analyzing stunting prevalence among Indonesian toddlers due to the lack of spatial variability in the data. The Breusch-Pagan test results indicate that there is no spatial heterogeneity in the data on stunting prevalence among Indonesian toddlers, as the p-value is less than the significance level of 0.05. The prevalence of undernourished toddlers is the main factor influencing stunting among Indonesian toddlers.

Effectiveness of Lime Leaves (Citrus aurantifolia) as a Natural Mosquito Repellent

Rahmi Garmini — 2024-12-09

The tropical climate gives rise to various kinds of tropical diseases, one of which can be caused by mosquitoes. The aim of this research was to determine the effectiveness concentration of lime leaf extract (Citrus aurantifolia) in repelling the Aedes aegypti mosquito. The research method used was an experiment by observing the effect of lime leaf extract as a natural mosquito repellent. Data processing used the one way anova statistical test, namely by using treatment plus 1 control in each treatment with 3 repetitions of the experiment. The results of this research were that there were differences in the treatment of orange leaf extract with a p-value (0.0005). The conclusion of the research is that the significant extract group is the 60 mg - 40 mg, 60 mg - 50 mg treatment, meaning that 60 mg of orange leaf extract treatment is the most effective as a natural insecticide.

Optimization of Domestic Wastewater Treatment Using a Mixture of Coconut Shell Activated Carbon Adsorbent and Fly Ash

Ikbal Oktaviansyah — 2024-12-09

Utilization of solid waste raw materials in the form of coconut shells and fly ash as adsrobents for domestic wastewater treatment. This study aims to optimize the effect of coconut shell activated carbon and fly ash with variations in mass ration and stirring time on changes in pH, COD, BOD, ammonia, TSS, and total coliform by adsorption on domestic liquid waste to meet waste quality standards. The research method includes the preparation of activated carbon from coconut shell, SEM characterization and experiments of a mixture of coconut shell activated carbon mass and fly ash (5:10, 10:5, 5:15, 15:5 grams) with variations in stirring time (30 minutes, 60 minutes). The results of the study, the most optimal mixture for changes in pH, ammonia, TSS, COD, BOD, total coliform parameters in domestic wastewater was a mixture of coconut shell activated carbon adsorbent mass of 15 grams and fly ash of 5 grams with a stirring time of 60 minutes.

Analysis Corrosion Rate Carbon Steel by Mg Anode and Na2Cr2O7 in Musi River Water Media

M Ali Komaini — 2024-12-10

This study aims to analyze and optimize the effect of Mg anode and sodium dichromate sacrificial protection on the corrosion rate of carbon steel in Musi River water media. The research involved carbon steel pipes (½ inch, 1 cm length) with an ID of 18.20 mm and OD of 18.80 mm. Four variables were tested: A (no corrosion prevention), B (Na2Cr2O7), C (Mg anode), and D (Na2Cr2O7 with Mg anode), each immersed in 150 ml of Musi River water for periods of 20, 30, 40, 50, and 60 days. Results showed the highest pH drop in variation A, where the initial pH of 6.87 decreased to 4.13 after 60 days. Variation A also showed the greatest increase in Fe concentration, rising from 1.47 mg/L to 4.89 mg/L, and turbidity from 80.8 NTU to 88.3 NTU after 60 days. Corrosion rate analysis indicated that carbon steel without corrosion prevention had the highest corrosion rate, reaching 0.0000025746 mpy after 60 days. In comparison, carbon steel with Na2Cr2O7 and Mg anode protection exhibited significantly lower corrosion rates. These findings highlight carbon steel pipes without corrosion protection experience higher degradation in Musi River water, while sodium dichromate and Mg anode treatments effectively reduce corrosion.

Differences in Fasting Total Cholesterol Levels in Serum and Plasma Edta Samples Using Biosystem Ba200

Aristoteles — 2024-12-10

Examination of total cholesterol levels in serum samples is more often used as an examination material, but serum samples often encounter difficulties due to insufficient blood volume or the condition of the serum being lysed due to poor sampling. Many studies have been conducted to look at total cholesterol levels using the anticoagulants EDTA, Sodium Citrate, and Sodium Oxalate to look at differences in total cholesterol levels, but not many studies have looked at tests of differences in total cholesterol test results during fasting with serum and EDTA. This study aims to determine differences in total cholesterol levels in the fasting state of EDTA serum and plasma samples using the BA200 biosystem. The type of research used was cross sectional, which was carried out at the Hematology Laboratory of the Palembang Muhammadiyah Institute of Health Sciences and Technology and the Palembang Health Laboratory Center. A sample of 30 people was taken purposively, female, and fasting for 10 hours. Based on the results of examining total cholesterol levels in a fasting state using the Biosystem BA200, the average result for serum samples was 4.8 mmol/L and the average for plasma samples was 4.7 mmol/L. Analysis was carried out using an independent sample T-test and the result was p = 0.00, the hypothesis was accepted. This research can conclude that there is a difference between the results of examining total cholesterol levels in fasting serum and EDTA plasma samples using the BA200 biosystem.

Optimization of Palm Shell Drying to Enhance Adsorption Performance: A Kinetic Study and Exponential Model

Surya Hatina — 2024-12-12

Palm shell has great potential as an adsorbent material due to its porosity and thermal stability, but its high moisture content can affect its surface area and absorption capacity. This study aims to optimize the drying process of palm shells to enhance their adsorption performance by applying an exponential model. The drying process was carried out at a temperature of 80°C with time variations ranging from 1 to 6 hours. Parameters measured included wet and dry moisture content, Moisture Ratio (MR), and drying rate. The results showed that drying the palm shell for 4 hours yielded the best results, with a reduction in wet moisture content by 19-21% and dry moisture content by 23-28%. The exponential model analysis provided drying rate constants for the three samples of 0.0443, 0.0238, and 0.0159, respectively. The measured MR graph compared with the model predictions showed a very good fit, with an R² value close to 1, meaning the exponential model is effective in predicting the drying rate. Adsorption performance was tested using a Dylon dye solution with a concentration of 25 ppm, where the palm shell was able to adsorb up to 85% of the dye within 180 minutes.

Numerical Simulation of Run-Up Wave Using Nonlinear Shallow Water Equations with Staggered Grid at Canti Beach, South Lampung

Dear Michiko Mutiara Noor — 2024-12-16

Tsunamis, wave triggered by underwater earthquakes or volcanic eruptions, can achieve significant run-up heights upon reaching shore. Run-up refers to the maximum vertical distance a tsunami wave reaches above the normal sea level. This study employs a numerical model to simulate the run-up wave at Canti Beach, South Lampung Regency, during the 2018 Sunda Strait tsunami. The method approximates solutions to the shallow water model consisting of mass and momentum conservation equations using the finite difference method in staggered grid grids and incorporates the upwind method for nonlinear terms. Bathymetry data from GEBCO was projected in two dimensions using the haversine formula. The numerical scheme includes a wet-dry procedure for simulating run-up waves. Results indicate that waves with a 60-second period and 0.09-meter amplitude create a 40.0195-meter inundation area, although this amplitude is significantly lower than the observed data from the 2018 Sunda Strait tsunami. Additionally, a simulation with a 0.1-meter amplitude results in a 1.8299-meter run-up height, closely matching the observed data. This study demonstrates that nonlinear shallow water equations can effectively estimate run-up height and inundation area at Canti Beach.

A Study of Mathematical Problems as Control Agents in the Industrial Sector

Ulul Ilmi — 2024-12-17

PD Utama Jaya Plasindo, a company specializing in plastic pellet processing, faces several production challenges, such as fluctuating demand, raw material shortages, machinery downtime, and labor management. To address these issues and improve production planning, the company uses MATLAB's linprog tool, which is designed for Linear Programming (LP) and aims to maximize profits. The company's profit is calculated using the formula: Profit = 37A + 46B + 38C + 46D. This calculation takes into account seven constraints related to raw materials, machinery usage, labor hours, and product demand. With this method, PD Utama Jaya Plasindo earns a daily profit of Rp. 837,600 from its plastic buckle products, totaling Rp. 16,752,000 over 20 working days in a month. These profit figures, based on clear objectives and constraints, help ensure that production goals are met and facilitate the monitoring and optimization of production capacity. By leveraging MATLAB's linprog, the company can better manage demand fluctuations and optimize the use of raw materials, machinery, and labor.

Preliminary Study on the Measurement of Cadmium Levels in Scavenger Hair at Sukawinatan Landfill Palembang

Yunita Panca Putri — 2024-12-17

Cadmium (Cd) is a toxic heavy metal with the potential to contaminate the environment, particularly in landfill sites using open dumping systems, such as the Sukawinatan Landfill in Palembang. This study aims to measure Cd levels in scavengers’ hair as an indicator of heavy metal exposure. A cross-sectional study design was conducted in January 2024, with hair samples collected from five respondents using purposive sampling techniques. Cd levels were measured using the Atomic Absorption Spectrophotometry (AAS) method. The results showed that Cd levels in the scavengers' hair ranged from 0.31 to 0.99 ppm, exceeding the normal limit set which is <0.10 ppm. The duration of work as a scavenger was identified as the dominant factor influencing Cd levels, although anomalies were observed in younger scavengers with high exposure intensity. These findings suggest that the working environment at the landfill significantly contributes to the accumulation of Cd in the body. This study provides preliminary insights into the health risks faced by scavengers at the Sukawinatan Landfill, which can serve as a basis for developing policies and mitigation measures to improve scavengers' occupational health and safety.