cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Is Fatimah
Contact Email
eksakta@uii.ac.id
Phone
+6282326298724
Journal Mail Official
eksakta@uii.ac.id
Editorial Address
Faculty of Mathematics and Natural Sciences Universitas Islam Indonesia Jl. Kaliurang Km 14, Ngaglik, Sleman, Yogyakarta, 55584
Location
Kab. sleman,
Daerah istimewa yogyakarta
INDONESIA
EKSAKTA: Journal of Sciences and Data Analysis
Published by Universitas Islam Indonesia
ISSN : 27160459     EISSN : 27209326     DOI : 10.20885
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Materials Science & Nanotechnology
Ekstakta is an interdisciplinary journal with the scope of mathematics and natural sciences that is published by Fakultas MIPA Universitas Islam Indonesia. All submitted papers should describe original, innovatory research, and modelling research indicating their basic idea for potential applications. The Journal particularly welcomes submissions that focus on the progress in the field of mathematics, statistics, chemistry, physics, biology and pharmaceutical sciences.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 10 Documents
 1 
Search results for , issue "VOLUME 2, ISSUE 2, August 2021" : 10 Documents clear
Implementation of Minkowski-Chebyshev Distance in Fuzzy Subtractive Clustering Annisa Eka Haryati; Sugiyarto Surono; Suparman Suparman
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art1

Abstract

Clustering is a method of the grouping which is done by looking at the similarities between data in a data set. Fuzzy clustering is a clustering method that uses fuzzy set membership values as the basis for grouping data. Fuzzy Subtractive Clutering (FSC) is a fuzzy clustering method where the number of clusters to be formed is unknown. The concept of FSC is to determine the highest data density and the data with the most number of neighbors will be selected as the center of the cluster. Thus, the size of the proximity or distance between points is needed to determine the members of each cluster. The distance used in this study is a combination of the Minkowski and Chebyshev distances. The number of clusters formed will be evaluated using the Partition Coefficient (PC) value where the highest PC value indicates the best number of clusters. The results obtained indicate that the best clusters are three clusters with a PC value of 0.7422
Prediction of Outstanding Claims Liability in Non-Life Insurance: An Application of Adaptive Grey Model Mujiati Dwi Kartikasari; Hani’atul Maghfuroh
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art4

Abstract

In order to assess the solvency of non-life insurance companies, the prediction of outstanding claims liability is very important. Prediction of outstanding claims liability is usually done by using a run-off triangle data scheme. However, if data are not available to form the scheme, the prediction of outstanding claims liability cannot be made. Another alternative for predicting of outstanding claims liability is to use time series analysis. This research uses an adaptive grey model that has the advantage of being free of assumptions of data patterns and a minimum amount of data used to predict is small (at least 4 data). To determine the accuracy of the adaptive grey model, we compare the prediction of outstanding claims liability using a grey model classic. Based on the analysis results, the adaptive grey model is better than the classic gray model in predicting outstanding claims liability.
Composite of Polylactic Acid/Chitosan/Ag-Hydroxyapatite Synthesized Using Turmeric Leaves Extract-Mediated Silver Nanoparticle and Snail Shell as Antibacterial Material Rahmania Audita; Khoirunisa khoirunisa; Hasna' Azizah Azzahra'; Bambang Hernawan Nugroho; Habibi Hidayat; Is Fatimah
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art5

Abstract

The development of an antibacterial composite of polylactic acid/chitosan/silver nanoparticle-doped hydroxyapatite has been synthesized. The composite was prepared using the silver nanoparticles (AgNPs) green synthesized by using turmeric (Curcuma longa Linn) leaves extract-mediated AgNPs and snail shell as biogenic calcium for hydroxyapatite synthesis. The precipitation method of hydroxyapatite by the doping of AgNPs was the first step, followed by composting with polylactic acid and chitosan as the polymer binder. Physicochemical characterization of the material was studied by using XRD, SEM, and FTIR analyses, and the antibacterial catalytic performance was examined against Escherichia coli (E. coli). The results showed that the synthesized AgNPs are within the <100 nm range in size and not significantly influence the crystallinity of the Ag/HAp. The composite materials maintained the antibacterial activity against E. coli.
Microwave and Ultrasound Irradiations for the Intensification on Biodiesel Productions: a Mini Review Suresh Sagadevan; Amri Yahya; Is Fatimah
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art6

Abstract

This mini review discusses the roles of intensification process in biodiesel production. Due to the Twelve Principles of Green Chemistry as a foundation for sustainability, the shorter time and efficient energy consumption highlighted the use of microwave and ultrasound irradiation for increasing conversion of biodiesel.The principles and some examples for the process are exhibited. It can be summarized that the intensifications are important innovations, but some optimization and life cycle analysis are required in applicable scales.
Evaluation of Heavy Metals Concentration in Milk Products by using Atomic Absorption Spectroscopy Nurul Auni Zainal Abidin; Nur Sofiah Abu Kassim Kassim; Sheikh Ahmad Izzadin; Sheikh Mohd Ghazali; Noor Hidayah Pungot; Siti Sufiana Kamni
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art7

Abstract

Milk products are essential food in the human diet because it contains many essential trace minerals such as calcium, magnesium, copper, zinc, sodium, potassium and phosphorous. The utilization of, milk is increasing at a large scale throughout the world. It is essential to maintain the good quality of milk during production and manufacturing because the presence of toxic metals in the milk becomes the cause of health disturbance in human life. Therefore, the present investigation was carried out to determine concentrations of lead, nickel, iron, copper, and chromium in powdered milk and fresh milk products by Atomic Absorption Spectroscopy. Different milk samples of products (two fresh milks and two powdered milks) were purchased from the local market. For the decomposition of the organic substances in milk samples, wet digestion was used with a mixture of nitric acid and sulfuric acid in volume proportions 1:3 (v/v). The analytical curve for all metals covered the linear range from 0.5 to 4.0 ppm with correlation coefficients higher than 0.9994. The limit of detection (LOD) for Pb, Ni, Fe, Cu, and Cr were found to be 0.25, 0.023, 0.012, 0.0067, and 0.073 ppm, respectively. While the limit of quantification (LOQ) in the range of 0.02 to 0.76 ppm. Of all the metals determined, Pb, Ni, and Fe were the most abundant with concentrations between 1.233 and 1.677 ppm while Cr was not detected in all the samples. The results showed that fresh milk samples have a higher concentration of heavy metals compared to powdered milk samples.
Utilization of Cassava Processing Liquid Waste as Raw Material for Making Biodegradable Plastics with the Addition of Glycerol Plasticizer Iswendi Iswendi; Iryani Iryani; Alpira Alpira; Regi Fadila Putra
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art2

Abstract

This study aimed to utilize cassava processing liquid waste into biodegradable plastic with glycerol as a plasticizer. This experimental study varies the amount of glycerol: (0, 1, 2, 3, 4, and 5) mL. The resulting biodegradable plastics were analyzed for physical properties consist of (water content and degree of swelling), mechanical properties consist of (tensile strength, elongation, elasticity), biodegradation, and structural properties. Fourier Transform Infra-Red and x-ray diffraction were employed for the studies. The results showed that the more glycerol added, the greater the percentage of water content and the degree of swelling were obtained. The optimum tensile of the biodegradable plastic was reached with 3 mL of glycerol, giving the strength of 27.49 N/mm2, elongation 0.107 N/mm2, elasticity 4.804 MPa. Biodegradable plastic with the addition of 5 mL of glycerol degraded up to 60.777%. The FTIR spectra showed almost the same peaks between plastics without the addition of glycerol and glycerol. Meanwhile, XRD data shows that the degree of crystallinity of plastic without glycerol is higher than that of plastic with the addition of glycerol.
Impacts of Human Development Index and Percentage of Total Population on Poverty using OLS and GWR models in Central Java, Indonesia Duhania Oktasya Mahara; Achmad Fauzan
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art8

Abstract

Central Java province is one of the provinces with the highest number of poor people on the island of Java, with the number of poor people in 2020 increasing by 0.44 million people from the previous year. Poverty is caused by several factors, one of which is the Human Development Index (HDI) and the Total Population level. Each region has different characteristics from other regions. These differences in characteristics cause more specific spatial effects, namely spatial heterogeneity. Geographically Weighted Regression (GWR) is a statistical method that can analyze spatial heterogeneity by assigning different weights and models to each observation location. This study aims to determine whether the HDI variable and percentage of total population significantly impact the number of poor people in Central Java Province in 2020 without eliminating the spatial effect. There are three groupings of variables that affect the Number of Poor People for GWR with the Adaptive Kernel Bisquare weighting function and four groups for the Adaptive Kernel Tricube weighting function. The Key Performance Indicators (KPI) used are Mean , Akaike Information Criterion (AIC), Absolute Error (MAE), Mean Square Error (MSE), and Mean Absolute Percentage Error (MAPE). Based on these KPIs, the GWR model with the Adaptive Kernel Bisquare weighting function provides better results when compared to the OLS model.
Hierarchical Clustering Approach for Region Analysis of Contraceptive Users Dina Tri Utari; Denesa Salma Hanun
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art3

Abstract

Through increasing the use of contraceptives to limit births, the Family Planning (KB) Program is one of the government's efforts to control the rate of population growth. Klaten Districts is one of the regencies in Central Java Province with a relatively high number of births and relatively low coverage of active family planning. This study aimed to determine the grouping of sub-districts and these characteristics in the Klaten Districts in 2020. The method used in this study was a hierarchical cluster analysis method, with the best method being the centroid method. In this study obtained 3 clusters with cluster 1 consisting of 23 sub-districts, cluster 2 consists of 2 sub-districts and cluster 3 with 1 sub-district. The cluster characteristics based on the highest number of users of contraceptive methods are cluster 1-contraceptives injection, cluster 2- contraception implant, and IUDs in cluster 3
The Encapsulation Process of Flavonoid from Kepel Seeds (Stelechocarpus burahol) Umi Rofiqah; Diora Ananda; Ilhamy Nurrahmah
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art9

Abstract

Flavonoid contained in Kepel seeds was extracted and encapsulated using a crosslinker agent of natrium tripolyphosphate (NaTTP) aiming for protection of the flavonoid content as an antioxidant. Extraction was carried out in variation of ethanol concentration and time extraction to obtain the best extract flavonoid. Fourier Transform Infrared Spectrometry (FT-IR) method was used to determine the presence of flavonoids in the extract. Total flavonoids (TF) analysis was carried out using a UV-Vis spectrophotometer. The highest total flavonoid content was obtained in the extract with 50% ethanol concentration was 2.427% for one hour and 2.888% for two hours.
Effect of Virgin Coconut Oil from Green Coconut on High-Density Lipoprotein (HDL) Levels in Blood Serum of White Mice Iswendi Iswendi; Iryani Iryani; Regi Fadila Putra
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 2, ISSUE 2, August 2021
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol2.iss2.art10

Abstract

This study aims to determine the effect of High-Density Lipoprotein (VCO) dose on mice's blood serum High-Density Lipoprotein (HDL) levels. This study is an experimental study using 24 mice divided into four groups. Control (-), Control (+) were fed egg yolks 0.025 mL/g body weight, Dose 0.02 and Dose 0.025 were experimental groups, given egg yolks 0.025 mL/g mice body weight and VCO at a dose of 0.020 mL, and 0.025 mL/g body weight of mice. HDL levels were determined on days 7, 14, and 21 by enzymatic method using 20 D* spectrophotometry. The statistical test found that the length of time giving VCO significantly affected blood serum HDL levels in mice with Fcount > Ftable (Fcount = 7.128 and Ftable = 5.14). In contrast, variations in VCO dose did not significantly affect blood serum HDL levels. mice with Fcount < Ftable (Fcount = 3.33 and Ftable = 4.76). The highest HDL level was at a dose of 0.020 mL/g body weight of mice with a treatment period of 14 days, namely 164,033 mg/dL of blood.

Page 1 of 1 | Total Record : 10

 1 

Filter by Year

2021 2021


Reset
Filter By Issues
All Issue VOLUME 6, ISSUE 2, October 2025 VOLUME 6, ISSUE 1, April 2025 VOLUME 5, ISSUE 2, October 2024 VOLUME 5, ISSUE 1, April 2024 VOLUME 4, ISSUE 2, August 2023 VOLUME 4, ISSUE 1, February 2023 VOLUME 3, ISSUE 2, August 2022 VOLUME 3, ISSUE 1, February 2022 VOLUME 2, ISSUE 2, August 2021 VOLUME 2, ISSUE 1, February 2021 VOLUME 1, ISSUE 2, August 2020 VOLUME 1, ISSUE 1, February 2020 VOLUME 19, ISSUE 2, August 2019 VOLUME 19, ISSUE 1, February 2019 VOLUME 18, ISSUE 2, August 2018 VOLUME 18, ISSUE 1, February 2018 VOLUME 17, ISSUE 2, August 2017 VOLUME 17, ISSUE 1, February 2017 VOLUME 16, ISSUE 2, August 2016 VOLUME 16, ISSUE 1, February 2016 VOLUME 15, ISSUE 1-2, 2015 VOLUME 14, ISSUE 2, August 2014 VOLUME 14, ISSUE 1, February 2014 VOLUME 13, ISSUE 1-2, August 2013 VOLUME 13, ISSUE 1, February 2012 VOLUME 12, ISSUE 2, August 2011 VOLUME 12, ISSUE 1, February 2011 VOLUME 11, ISSUE 2, August 2010 VOLUME 11, ISSUE 1, February 2010 More Issue