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 231 Documents
 3   4   5   6   7 
Semiempirical Study On Electronical Transition Spectra Of Ethyl Pmethoxycinnamate (EPMS) From Kencur (Kaempferia Galanga) For Sunscreen Component Salmahaminati Salmahaminati; Mokhammad Fajar Pradipta
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 15, ISSUE 1-2, 2015
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol15.iss1-2.art4

Abstract

Telah dilakukan analisis in silico senyawa tabir surya Etil Para Metoksi Sinamat (EPMS) berdasarkan data transisi elektronik molekul senyawa yang bertujuan untuk memperkirakan EPMS sebagai senyawa tabir surya perisai alami UV-B. Kajian dilakukan dengan membuat model molekul senyawa tabir surya standar Isopropil Para Metoksi Sinamat (IPMS) yang dioptimasi geometri menggunakan metode semiempirik AM1 dan dilanjutkan optimasi analisis spektra transisi elektronik dengan metode ZINDO/S, ZINDO 1, PM3, dan AM1. Analisis spektra transisi elektronik difokuskan pada UV-B (290-315 nm). Hasil kajian secara umum menunjukkan analisis spekta transisi elektronik terbaik adalah ZINDO/s. Perhitungan dengan metode ZINDO/S pada IPMS menunjukkan λmax yaitu 290,77 nm dan senyawa EPMS diperoleh nilai λmax 292,41 nm. Hasil ini menunjukkan bahwa EPMS dapat dimanfaatkan sebagai perisai alami UV-B.
Decreasing in Acid Number of Patchouli Oil by Different Natural Adsorbent and Variation of Contact Time Tri Esti Purbaningtias; Bayu Wiyantoko; Puji Kurniawati; Mustika Kusuma Sari
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 14, ISSUE 1, February 2014
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

One way for improving (of improving atau to improve) the quality of patchouli oil was to reduce the acid number. Acid number could be reduced with the use of natural adsorbents. The decreasing percentage acid number of patchouli oils using adsorbents zeolites, bentonite, rub ash, and activated carbon, respectively 4.71 %; 1.45%; 7,84%; and 4.64%. The contact time could influence the decrease in acid number of patchouli oil. The longer the contact between adsorbent and oil could caused a decrease in acid number. Maximum contact time for rub ash was 15 hours with a maximum adsorption capacity of 14,34% for 0.1 gram adsorbent
The Implementation Of Apriori Algorithm And Chi-Square Test In Determining Pattern Of Relationship Among The Rawi Hadis Rahmadi Yotenka
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 17, ISSUE 1, February 2017
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol17.iss1.art3

Abstract

In this research apriori algorithm was implemented on rawi data of hadits to find out pattern of relationship among the rawi hadits in shahih bukhori book. The analogy that can be compared is by assuming that series or chain of rawi in every sanad of hadis may be regarded as transaction, while rawi hadis were items in transaction. Data mining is the method that was used to analyze with association rule technique. Association rule technique is used to find a pattern rule between a combination of items. To find out association rule by using association rule application, it is used apriori algorithm by observing three important measurement, namely support, confidence, and lift values. The analysis result of apriori algorithm showed that for minimum support 0.03 and minimum confidence 0.9 having 9 strong association pattern based on the sequence of rawi hadis of its sanad. Every rule of association which was strong, then tested by chi-square to prove that the rawis that were in the rule were truly connected or statisticly significance
Formulation and Evaluation of Kaptopril Tablets Using Threaded Amylum Tubes and HPMC as Fillers and Binders of the Direct Method Ahmad Sastra Kelana; Aris Perdana Kusuma; Oktavia Indrati
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 18, ISSUE 1, February 2018
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol18.iss1.art2

Abstract

Indonesia is a tropical country which has many potential plants as excipients, likestarches and tubers. Amylum of taro tuber (Colocasia esculenta) has the potential to be developed into excipient but its use is limited. The purpose of this study was to optimize the formulation and to evaluate the characteristics of captopril tablets by using amylum of taro tuber and HPMC modified as filler and binder on direct compression method. Amylum of taro tuber was obtained by extraction process, then combined with HPMC by partial pregelatination and co-process method. Variation of the starch was divided into five formulation. The main test included friability test, hardness test, dissolution test, and assay. The data analysis was done by theoretical approach between the evaluation result and the literature to observe the result of the modification formulation. It indicated that the combination of equal amount of taro amylum and microcrystalline cellulose (MCC) pH 102 (50% : 50%) has the best result among others. Friability percentage was 0.17 ± 0.07%, disintegration time was 12.09 ± 0.52 minutes, assay was 97.88 ± 1.71% and dissolution test results was 90.65 ± 4.81%.
Perbandingan Metode Regresi Spline Truncated dengan Regresi Linear Sederhana untuk Kasus Harga Saham Perusahaan Pertambangan di Indonesia Edy Widodo; Adisti Nurul Irmayanti
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 19, ISSUE 2, August 2019
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol19.iss12.art5

Abstract

Saham merupakan surat berharga  yang dapat dibeli dan dijual oleh perorangan atau badan usaha sebagai tanda penyertaan kepemilikan seseorang maupun badan usaha dalam suatu perusahaan atau perseroan. Salah satu saham yang mengalami dampak dari fenomena krisis ekonomi global adalah perusahaan pertambangan. Harga saham dipengaruhi oleh kurs rupiah. Data harga saham dan kurs rupiah masuk ke dalam kategori data longitudinal. Untuk menangani data longitudinal dibutuhkan analisis yang tepat, salah satunya dengan menggunakan pendekatan nonparametrik regresi spline truncated untuk mengetahui bagaimana pengaruh kurs rupiah terhadap harga saham. Model terbaik pada metode ini bergantung pada penentuan titik knot optimal, yaitu titik knot yang memiliki nilai GCV minimum. Model regresi spline truncated terbaik terletak pada orde 2 dengan 3 titik knot untuk PT Adaro Energy Tbk. dan PT Aneka Tambang Tbk., sedangkan untuk PT Indo Tambangraya Megah Tbk. berada pada orde 3 dengan 2 titik knot. Dengan pembanding nilai MAPE, hasil prediksi dengan menggunakan regresi spline truncated lebih baik daripada regresi linear sederhana Adapun nilai MAPE yang dihasilkan adalah 7,81% untuk PT Adaro Energy Tbk., 8,51% untuk PT Aneka Tambang Tbk., dan 12,74% untuk PT Indo Tambangraya Megah Tbk.
Prediction Using Distributed Lagged Subset Model Suparman Suparman
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 12, ISSUE 1, February 2011
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

This  article  examines  the  problem  of  determining  the  future  value  of  the  dependent variable in the distributed lagged subset model. Unlike a distributed lag model in general, which assumes that all coefficients are not zero. In a distributed lagged subset model, some coefficients may be zero. The purpose of  this  study was  to determine  the predictive value of  the dependent variable in a distributed lagged subset model. The approach used to estimate the parameters of a distributed lagged subset model is the least square method and Ck statistic. Least squares method is used to determine the estimators of the coefficient of a distributed lagged subset model. Ck Statistic is used to select the best distributed lagged subset model. Some  simulations are delivered and prove  the efficiency of  this approach. Furthermore, this approach is implemented in real economic data.  Keywords : Distributed lagged subset model, Prediction, Least square method, Ck Statistic.  
Hepatoprotective Effect of Corn Silk Infusion in Male Wistar Rats Arba Pramundita Ramadani; Hady Anshory Tamhid; Tika Luthfi Sadrina; Jasno Jasno; Mabrurotul Mustafidah
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 1, ISSUE 1, February 2020
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol1.iss1.art8

Abstract

The use of medicinal plants in treating various disease has been reported since long time ago, including for hepatic disease. Corn silk contains phytochemicals of medical benefit such as flavonoids compounds which act as antioxidant agents and has been widely reported possess hepatoprotective effect. Using a model of carbon tetrachloride (CCl4)-induced hepatotoxicity in 36 male Wistar rats, this study investigated the effect of corn silk infusion and assessed using enzymes produced by the liver in plasma [alkaline phosphatase (ALP) and liver glutathione (GSH)]. The corn silk infusion (in 50, 100, and 200 mg/kg BW doses) were administered 24 hours after CCl4-induction liver damage with 3ml/kg BW CCl4 in olive oil (1:1, v/v), intraperitoneally for seven days. Along with corn silk groups, distilled water (0.2 mL/kg BW) and Curcumin (100 mg/kg BW) were given for induction and drug control, respectively. In the end of the study (8th day), the level of both ALP dan GSH were measured. The differences among groups for GSH and ALP level were statistically calculated using ANOVA method.  The result showed that the corn silk infusion is active at 200 mg/kg BW based on both ALP (18.74% decreased) and GSH (5-7% increased) level. Moreover, the flavonoid compound was detected on the infusion that may contribute on its hepatoprotective activity. In conclusion, corn silk infusion owned hepatoprotective effect in male Wistar rats.
Aktivitas Antimikroba Asam-3-Hidroksi-4-Metoksi Mandelat Muhamad Agus Wibowo; Lucy Arianie
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 12, ISSUE 2, August 2011
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Telah dilakukan uji antimikroba senyawa asam-3-hidroksi-4-metoksi mandelat terhadap bakteri Escherichia coli dan Bacillus subtilis. Hasil uji pada bakteri Escherichia coli menunjukkan bahwa senyawa uji mampu menghambat pertumbuhan bakteri Escherichia coli dengan zona hambat 1,90 cm (30 ppm), 1,96 cm (100 ppm) dan bersifat bakteriostatik. Pada uji dengan bakteri Bacillus subtilis menunjukkan bahwa senyawa uji mampu menghambat pertumbuhan bakteri Bacillus subtilis dengan zona hambat sebesar 1,60 cm (30 ppm), 1,85 cm (100 ppm) dan bersifat bakteriosid.   Kata kunci: asam-3-hidroksi-4-metoksi mandelat, aktivitas, antimikroba
Ethanol Concentration Effect of Mangoesten Pell Extract to Total Phenol Content Mustofa Ahda
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 14, ISSUE 2, August 2014
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol14.iss2.art6

Abstract

Telah penelitian tentang pengaruh konsentrasi etanol terhadap kandungan fenol total pada kulit manggis. Penelitian ini bertujuan sebagai effisiensi penggunaan pelarut yang digunakan dalam proses ekstraksi. Proses ekstraksi yang digunakan dalam penelitian ini menggunakan teknik maserasi. Penelitian ini dengan melakukan variasi konsentrasi etanol 100%, 80%, 50%, 20%, 0% sebagai pelarut yang digunakan dalam proses maserasi selama 24 jam disertai dengan pengadukan. Kemudian hasil ekstrak cair dievaporasi sampai mendapat ekstraks kental, dan selanjutnya ekstraks kental diuapkan sampai memperoleh ekstraks kering masing-masing pelarut tersebut. Hasil penelitian menunjukkan bahwa konsentrasi etanol 100% mampu melakukan proses ekstraksi yang optimal dengan kandungan total fenol sebesar 35,21% b/b yang equivalen terhadap asam galat.
Bootstrapping Residuals to Estimate the Standard Error of Simple Linear Regression Coefficients Muhammad Hasan Sidiq Kurniawan
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 16, ISSUE 2, August 2016
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol16.iss2.art1

Abstract

Regression models are the statistical methods that widely used in many fields. The models allow relatively simple analysis of complicated situations. The aim of the regression models is to analyze the relationship between the predictor and response. In order to do that, we have to estimate the regression coefficient. In case of simple linear regression, the method to estimate the regression coefficient is either least square method or maximum likelihood estimation. Also, the standard error of the regression coefficient is being estimated. In this paper, we apply the bootstrap method to estimate the standard error of the regression coefficient. We compare the result of the bootstrapping method with the least square method. From this study, we know that the standard error estimation value of regression model using the bootstrap method is close to the value if we use the least square method. So we can say that the bootstrap method can be used to estimate the standard error of another regression models coefficient which does not have the closed-form formula

Page 5 of 24 | Total Record : 231

 3   4   5   6   7 

Filter by Year

2010 2025


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