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Eksakta : Berkala Ilmiah Bidang MIPA

eksakta
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Published by Universitas Negeri Padang

ISSN : - EISSN : 25497464 DOI : https://doi.org/10.24036/eksakta/

Core Subject : Science, Education, Agriculture, Social, Engineering,

Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Mechanical Engineering

Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464) is an open access journal and peer-reviewed that publishes either original article or reviews. The journal is dedicated towards dissemination of knowledge related to the advancement in scientific research. The prestigious interdisciplinary editorial board reflects the diversity of subjects covered in this journal. Under the realm of science and technology, the coverage includes environmental science, pure and applied mathematics, agricultural research and engineering, biology, biotechnology, bioinformatics, Healthcare sciences (including clinical medicine, preventive medicine & public health), physics, biophysics, computer science, chemistry and bioengineering, to name a few. This Journal Is Published at 3 Month intervals on January-Marc, April-June, July-September and October-December

Arjuna Subject : Umum - Umum

Articles 310 Documents

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EKSTRAKSI DAN KARAKTERISASI INULIN DARI UMBI DAHLIA (Dahlia sp.L) SEGAR DAN DISIMPAN Hevi Horiza; Minda Azhar; Jon Efendi
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 18 No. 01 (2017): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Inulin is a natural polymer composed of monomers fructose, which is connected with the linear bonding ?-2,1-fruktosil-fructose. One source of inulin is the dahlia tubers (65.700%). The purpose of this study was to determine the water content, degree of purity inulin and how the value of the degree of polymerization inulin from dahlia tubers fresh and stored 4 weeks kinds of decorative strands formal crimson crown. This research was conducted experiments in Chemistry Research Laboratory UNP. The object of research was a kind of decorative dahlia tubers formal crimson obtained in the area of Aia Tawa, Kampung Batu nature, Solok. Inulin was characterized by using GC (Gas Chromatograpy) and HPLC(High-PerformanceLiquidChromtography). Determination of water content by using method of the AOAC(Associationof Official of Analytical Chemist).The results showed that the water content of dry weight percent (bk) inulin from dahlia tubers fresh is 2.123%, Inui figure is not much different than the inulin from dahlia tubers stored 4 weeks 2.003%. Based on the GC spectrum can be analyzed qualitatively that inulin extracted from dahlia tubers have a degree of polymerization of smaller than commercialinulin. Chicory Based on the spectrum of HPLC showed that inulin extracted from the tubers of dahlias has a purity level is almost the same as inulin commercial Chicory merck Fluka.

PENGOLAHAN CITRA SATELIT ALOS PALSAR MENGGUNAKAN METODE POLARIMETRI UNTUK KLASIFIKASI LAHAN WILAYAH KOTA PADANG Farah Sarjani; Josaphat Tetuko Sri Sumantyo; Yohandri Yohandri
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 18 No. 01 (2017): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

The image processing of Alos PalSAR satellite data level 1.1 for land classification in Padang City is described in this work. The full polarimetry method is adopted in classification process which can receive and process all combinations of the four polarizations of HH, HV, VH, and VV. Yamaguchi Decomposition is applied in polarimetry method and four classification objects are obtained. Based on the modification of class simplification, the surface scattering is presented in blue color which generally describes the waters on the surface of the earth, green color for volumetric scattering, which describes about plants and forest, red or pink for the double bounce scattering depicting the settlement, urban and building and yellow for helix scattering which is the same as double bounce but the helix will more clearly identify the plant-covered settlements.

MODEL ESTIMASI GARCH DALAM MENGUKUR KINERJA NILAI TUKAR RUPIAH Imelda Saluza
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 18 No. 02 (2017): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

The exchange rate is determined by the demand and supply relationship of the currency. If the demand for a currency increases, while the supply remains or even decreases, then the exchange rate will rise vice versa. The ups and downs of exchange rates on the money market indicate the magnitude of the volatility that occurs in the currency of a State against the currencies of other countries. The volatility phenomenon indicates difficulty in analyzing the exchange rate. Increasing volatility indicates an even greater movement of currency exchange rates even if currency exchange rates experience extreme volatility resulting in economic instability both from the micro and macro sides. The high volatility seen from the pattern of price movements that occur in financial markets, and the impact that can be generated from the high volatility data is the error that will have a variance that is not constant. That is, a relatively high data variability at a time indicates the presence of heteroscedasticity. Heteroscedasticity can lead to errors in drawing a conclusion to the estimated model obtained. Therefore, we need a model that is able to solve the problem that is Generalized Autoregressive Conditional Heteroscedasticity (GARCH) model in order to get more accurate estimation model to estimate exchange rate. From the simulation result, all data contain the volatility seen from the result of heteroscedasticity test, and obtained estimation model for all data.

GRAFTING POLIPROPILENA DENGAN MALEAT ANHIDRIDA SEBAGAI PENGIKAT SILANG DENGAN INISIATOR BENZOIL PEROKSIDA Tengku Rachmi Hidayani
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 19 No. 1 (2018): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Padang 25171 (0751-7055053 – 081374388030) rachmihidayani@gmail.com ABSTRAK Telah dilakukan penelitian tentang fungsionalisasi polipropilena maleat anhidrida (MA) dengan inisiator benzoil peroksida (BPO) melalui metode refluks. Reaksi grafting dilakukan dengan metode refluks menggunakan pelarut xilena pada suhu 160oC dengan variasi komposisi (b/b) PP : MA : BPO, 97:1:2, 95:3:2, 92:6:2, 89:9:2, dan 86:12:2 . selanjutnya dilakukan penentuan derajat grafting dengan metode titrasi dan analisa spektra FTIR untuk menentukan adanya grafting maleat anhidrida pada rantai polipropilena. Hasil penelitian menunjukan bahwa proses grafting maleat anhidrida pada polipropilena dapat terjadi dan perbandingan berat campuran PP:MA:BPO (95:3:2) merupakan derajat grafting tertinggi maleat anhidrida.

PERTUMBUHAN STEK HORIZONTAL BATANG JARAK PAGAR (Jatropha curcas L.) YANG DIINTRODUKSI DENGAN PSEUDOMONAD FLUORESEN Linda Advinda
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 19 No. 1 (2018): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Jatropha curcas L. is one of the plants that can be developed as raw material of biodiesel. One of the efforts to increase the production of J. curcas is the propagation of stem cuttings horizontally. Efforts to stimulate root growth can be accomplished by adding Plant Growth Regulators (PGRs). PGRs can be obtained naturally or synthetically. Indole acetic acid (IAA) is one of PGRs, which is not only produced by plants but can also be produced by rhizobacteria. One such rhizobacteria is fluorescent pseudomonad. The objectives of the study were to know the response of growth of horizontal stem cuttings after being introduced with fluorescent pseudomonad. This research is an experimental research. Complete Randomized Design with 6 treatments and 4 replications. The treatments were soaking of J. curcas stem cuttings with fluorescent pseudomonad isolate suspension PfPj3 suspension concentration of 0% (without suspension), 5%, 10%, 15%, 20%, and 25%. Observation of the research is the beginning of the shoots, the number of shoots, and the length of the J. curcas stem shoot. The data obtained were analyzed using Anova and DNMRT significant level of 5%. The results showed that horizontal stem cuttings of J. curcas with fluorescent pseudomonad suspension influenced early shoot, shoot number, and shoot length. A 10% fluorescent pseudomonad concentration can cause shoots to appear early, while a concentration of 20% causes the largest number of shoots.

Modeling of Human Development Index Using Ridge Regression Method Ferra Yanuar; Mardha Tillah; Dodi Devianto
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 19 No. 2 (2018): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

This article aims to model factors affecting HDI (Human Development Index) in North Sumatera by 2015 using ridge regression method. This ridge regression method is used because in the IPM data there is a multicolinearity problem so that the least squares regression method, as regression method commonly used in statistical modeling, is not suitable for use any more. This study compares the models resulting from the use of the least squares method and the ridge regression method to the HDI data. This study proves that the ridge regression method produces a better model and can eliminate the multicolinearity effect, while the least squares method can not. The significant factors in affecting HDI on North Sumtera data in 2015 are Average School length and Total expenditure / capita / month. The indicator of the goodness of this ridge regression model is 81.81% which means that the model is good and could be accepted.

Preliminary Phytochemical Screening (Qualitative Analysis) of Cacao Leaves (Theobroma cacao L.) Hesty Parbuntari; Yona Prestica; Rizki Gunawan; Meri Novia Nurman; Fransiska Adella
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 19 No. 2 (2018): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

One of the important processes of cocoa plants growing is pruning. It aims to eliminate sick, broken, or the appearance of water buds disturbing the cacao production. The period of pruning is varios. The various periods of pruning lead to leave wide waste of leaves, stems, and twigs. Yet the waste would not been used to other activities, only a small portion of the waste used as natural fuel (stems and twigs) and cocoa leaves waste as animal feed. Phytochemicals naturally present in every part of plants range from leaves, stem bark, fruits to roots. Secondary metabolites are natural products from plants which include alkaloid, flavonoid, steroid, terpenoid, sapponin compounds, etc. This study performed some phytochemical characterisations. It have confirmed that cacoa leaves consist some of bioactives compounds which are potential for furhter activities in pharmaceutical disease.

The Hydrogen Generator Performance of Sandwich Designed 4/4 Al-Cu Plates Rahadian Zainul; Sri Whayu Wardani
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 20 No. 1 (2019): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

This research aims to make a 4/4 plate Al-Cu plate-based hydrogen generator. The method used is design and engineering as well as testing the performance of the gas produced during the electrolysis process of water. The results obtained are hydrogen reactors that are capable of producing 7.5 mL of gas from water with a supporting voltage of 2 V and an electric current of 0.6 A. In sodium acetate (CH3COONa) material 144 mL of gas is produced at a supporting voltage of 2 V and an electric current of 0.6 A.

Antimicrobial Activities of Extract of Andalas Endophytic Bacterial Fermentation Products in Overcoming Oral Cavity Infection Dwi Hilda Putri; Ratih Rahayu; Dinda Sahara; Nurhelmi Nurhelmi; Violita Violita
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 20 No. 2 (2019): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Dental and oral infection problems can be overcome using natural antimicrobial compounds from bacterial endophytic resulted from bacterial fermentation. This study aims to determine the effectiveness of extracts of Andalas endophytic bacterial fermentation products in treating oral cavity infections. Fermentation products was extracted using maceration methods. Antimicrobial activity of Andalas endophytic bacterial fermentation product was evaluated to S. mutans and C. albicans by disk diffusion method. The study showed that the optimum concentration of extract in inhibiting microbial growth that causes oral cavity infections was at 12.5%.

Isolasi dan Karakterisasi Flavonoid dari Beras Ketan Hitam (Oryza Sativa L. Var Glutinosa) Sri Benti Etika; Iryani Iryani
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 20 No. 2 (2019): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

This study aims to isolate and characterize the isolated flavonoid compounds from glutinous rice (Oryza Sativa L. Var Glutinosa). The method that used was maserasi with methanol solvent, multilevel fractionation with n-hexane and ethyl acetate. The separation of chemical components using column chromatography and tested its purity by melting point test and TLC. Characterization of isolated flavonoids using color reagents (H2SO4, NaOH, Mg-HCl), KKt-2A, UV-Vis and FT-IR. The powder (amorphous) flavonoid isolation results have a melting point of 236.5-237.8 oC. Flavonoid powder added H2SO4 produces a yellow color, with NaOH producing a violet color, and Mg-HCl produces a red color. KKt-2A with a BAA developer has Rf 0.49 and 15% acetic acid having Rf 0.09. The UV-Vis spectrum shows maximum absorption at 532 nm wavelength. The results of powder analysis (amorphous) flavonoid using FT-IR showed absorption at wave number 3.330,40 cm-1, 2838,96 cm-1, 1,656,23 cm-1, 1,421,85 cm-1, 1,112,25 cm-1, 1,019,27 cm-1 and 697,76 cm-1. According to those data it can be concluded that flavonoids that isolated have the form of powder (amorphous) which belong to anthocyanin group that have o-diOH on ring B and have a conjugated double bond.Keywords- Black Sticky Rice, Flavonoid, Fractionation, FT-IR, Maserasi, UV-Vis.

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Rahadian Zainul

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Editorial Address
Jl Prof Dr Hamka Air Tawar Barat

Location
Kota padang,

Sumatera barat

INDONESIA

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Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name Rahadian Zainul

Contact Email rahadianzmsiphd@fmipa.unp.ac.id

Phone +6281261385385

Journal Mail Official eksakta@ppj.unp.ac.id

Editorial Address Jl Prof Dr Hamka Air Tawar Barat

Location Kota padang, Sumatera barat INDONESIA

Abstract

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Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Contact Name
Rahadian Zainul

Contact Email
rahadianzmsiphd@fmipa.unp.ac.id

Phone
+6281261385385

Journal Mail Official
eksakta@ppj.unp.ac.id

Editorial Address
Jl Prof Dr Hamka Air Tawar Barat

Location
Kota padang,

Sumatera barat

INDONESIA