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INDONESIA
Jurnal Sains Dasar
ISSN : 20859872     EISSN : 24431273     DOI : 10.21831
Core Subject : Education,
Arjuna Subject : -
Articles 216 Documents
Identifikasi bifurkasi kodimensi-2 pada sistem flutter dengan menggunakan kriteria Routh Hartono, Hartono; Krisnawan, Kus Prihantoso
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (290.032 KB) | DOI: 10.21831/jsd.v3i1.2779

Abstract

In this paper, the codimension-2 bifurcation of a 2-parameter flutter system is identified using Routh’s criterion. Routh’s criterion is a tool to determine the number of roots of a real polynomial in the right half-plane. Based on this criterion, the regions borders of each parameter are determined in order to make the roots of flutter system characteristic equation have negative or positive real parts. A point is taken from each region and the phase portraits of the system are drawn. Based on the Routh’s table and the phase portraits, different dynamical structure that showing a pitchfork-hopf bifurcation is acquired. Key words: pitchfork-hopf bifurcation, flutter system, Routh’s criterion
Isolasi dan uji aktivitas enzim lipase termostabil dari bakteri termofilik pasca erupsi Merapi Drajat Pramiadi; Evy Yulianti; Anna Rakhmawati
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (399.462 KB) | DOI: 10.21831/jsd.v3i1.2780

Abstract

The usage of enzyme which comes from microorganism is more advantageous because it is easier to be multiplied in a relatively short time and does not need a large space, including lipase enzyme, which is often used in industries. The objective of this research is to isolate thermo stable lipase enzyme from thermophilic bacteria and to understand specific ativities. The thermophilic bacteria isolation is done using pour plate method. Selection of the bacteria producing lipase is shown from the presence of the biggest translucent zone around the colony on the olive oil medium with 0.1% Rhodamine-B. Two isolate produced by the biggest translucent zone are then continued by lipase enzyme isolation and activity tests. From 253 isolate, 43 isolate can grow on the medium that contains olive oil and 2 isolate shows translucent zone around the isolate, that is isolate 361 and isolate 213. The growth curve measurement for 24 hours shows that the exponential time is reached at the 10th hour for both isolates. The result of this research shows that temperature, pH, and enzyme isolate variation effects the enzyme activities. The enzyme activity tests show that on isolate 361, the best enzyme activities is obtained from incubation temperature of 50⁰C with pH 7, whereas for isolate 213, the best enzyme activities is reached when incubation temperature is 70⁰C with pH 6.   Key words: lipase, olive oil, thermophilic bacteria, thermo stable enzyme, enzyme activities
Application of matrix diagonalization on Markov chain Bidayatul hidayah; Rahayu Budhiyati; Putriaji Hendikawati
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (78.36 KB) | DOI: 10.21831/jsd.v3i1.2781

Abstract

Markov chain is a series of events in which the conditional probability upcoming events only depend on the current events and do not depend on the previous occurrence. Transition probabilities at the steady state level (steady state probability) is a transition probability that has reached equilibrium, so that it will not change with time or phase changes that occur. This paper determines the eigenvalue states ​​and diagonalization to determine the steady state. The solution is obtained by peeling definitions and theorems. Key words: matrix, matrix diagonalization, Markov chain
The password agreement method based on matrix operation over Min-Plus algebra for safety of secret information sending Musthofa Musthofa; Dwi Lestari
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (208.648 KB) | DOI: 10.21831/jsd.v3i1.2782

Abstract

Key agreement protocol is a method in cryptography. Key agreement protocol is used to overcome the problem of sending secret information over communication lines. A secret key, called password, is needed to secure t he information. Both parties who exchange confidential information must agree on the same key. In this method, both parties exchange mutual general parameters that everyone can see, however from the general parameters the same passwords can be formed and not publicly known. One method that has been used is applying a series of matrix multiplication operation defined over a finite field. In this study, we constructed an algorithm in the form of a key agreement protocol that can be used in the password agreement method which the level of security based on algebraic problem of matrix operation over Z- min plus algebra. Min Plus algebra over Z, that is Z È { + ¥ } with Z is the set of all integers equipped with the minimum and addition operation,  is called idempotent semiring. The results showed that the application of matrix operation over min plus algebra can be used as key agreement protocol in securing secret information.   Key words: secret information, password, Min-Plus algebra
Optimization of condensation reaction time between vanillin and p-nitroacetophenone in acid catalysts Indyah Sulistyo Arty Sulistyo Arty; Dini Rohmawati
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (91.856 KB) | DOI: 10.21831/jsd.v3i1.2783

Abstract

This study was an experimental study aimed to obtain the optimal time in the synthesis of chalcone compounds through cross aldol condensation reaction. The starting materials used were vanillin, p-nitroacetophenone, and acid catalyst. The study began by reacting vanillin and p-nitroacetophenone in HCl catalyst and the flow of nitrogen. The optimalization of reaction time was done in some variation of time, 3 hours, 5 hours and 7 hours. The reaction products were recrystallized with solvents mixture aquades: ethanol (1:1). Recrystallization product then checked by TLC using mixed eluents n-hexane: ethyl acetate (4:1). The products of the study were powder with the appropriate weight range and yield of the reaction time (3 hours, 5 hours and 7 hours) was 0.16 g: 5.387%, 0.48 grams: 16.162% and 0.43 grams: 14.478%. the optimum time for this reaction was 5 hours.   Key words: condensation, vanillin, p-nitroacetophenone, acid catalyst
Singing bio acoustic profile of Cicadidae around the enviroment of Mathematics and Natural Sciences Faculty Yogyakarta state University Hidayati, Sukarni; Subiantoro, Agung W.
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (484.947 KB) | DOI: 10.21831/jsd.v3i1.2785

Abstract

This research is done to identify and describe the singing bio acoustic profile of Cicadidae in the environment of Mathematics and Natural Sciences, Yogyakarta State University. This research is a descriptive research through naturalistic observation. The research sample is determine using sampling scan technique for sound which has a highest trending sound intensity on three spots or observation area. The research variables consist of emergence time and Cicadidae singing bio acoustic characteristic. The research instrument used is the Cicadidae singing (sound) audio recorder to obtain Cicadidae singing recording and also the emergence time interval, and bio acoustic (audio) sound analysis software to analyze physical-digitally the characteristic of Cicadidae singing bio acoustic. The data analysis of Cicadidae singing bio acoustic is done descriptively through the analysis results of spectrogram and oscillogram description to show the Cicadidae singing audio characteristic pattern.   Key words: bio acoustic proifle, singing, Cicadidae
Condition optimization of sea pandan leaves biosorben synthesis and adsorptivity test on chromium and lead metal ions in different kinds of waste Susila Kristianingrum; Endang Dwi Siswani; Annisa Fillaeli
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1129.971 KB) | DOI: 10.21831/jsd.v3i1.2786

Abstract

This study aims to determine whether or not biosorben synthesized from sea pandanus leaves, the influence of the type of acid used, the optimum adsorption efficiency of Cr and Pb metal ions from various wastes, as well as the synthesis results of biosorben character. The subjects were biosorben of sea pandanus Pandanus tectorius types of Java's southern coast. The objects are adsorptive properties and the character of the pandanus sea biosorben synthesized before and after activation. Purposive sampling is used as the sampling technique. The independent variables are the type of activator (HCl and H2SO4) and waste water. The dependent variables are the adsorptive nature and character of the sea pandanus biosorben synthesis results. The study was conducted in three phases, namely the manufacture of biosorben sea pandan leaves, characterization and determination of adsorption efficiency (Ep) biosorben synthesized on metal ions of Cr and Pb in batik waste, leachate, and oil. Qualitative and quantitative analysis are done using Atomic Absorption Spectrophotometer instrument at a wavelength of 357.9 nm for Cr and 217 nm for Pb. Biosorben characterization was conducted on the moisture content, ash content, volatile content, and carbon content compared with SNI 06-3730-1995 and analyzed by FTIR spectra. It is also seen biosorben surface area of synthesized both before and after activation by porosimetry. Biosorben of pandanus sea has to be synthesized. Biosorben synthesized with 5% H2SO4 solution produced optimum Ep for Cr and Pb metal ions from waste leachate obtained are 75.831% and 98.714%. Character biosorben activation results in a solution of 5% HCl and H2SO4 by FTIR have almost similar spectra. Moisture content, ash content, volatile content, and carbon content of biosorben synthesized with 5% HCl and 5% H2SO4 in accordance with SNI 06-3730-1995. Porosimetry characterization of biosorben synthesized before activation is 3.5756 m2 / g, whereas after activation with HCl 5% to 770.7636 m2/g, and after activation with 5% H2SO4 solution become 153.7002 m2/g. Keywords: biosorben, sea pandanus, adsorptivity test, chromium, lead
Callus induction of binahong leaves (Anredera cordifolia L.) for the development of traditional medicinal plant Lili Sugiyarto; Paramita Cahyaningrum Kuswandi
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (426.665 KB) | DOI: 10.21831/jsd.v3i1.2787

Abstract

A plant that has a good prospect in the development and cultivation as medicinal plant is binahong (Anredera cordifolia L.). Secondary metabolites have been used as coloring substance, food coloring, and medicine. Callus induction using tissue culture has been used to produce secondary metabolite with a higher concentration than obtained directly from the plant. The aim of this research was to induce callus from the leaf of Binahong using various concentrations of Plant Growth Hormones in MS media. The method used in the propagation of callus used the leaf explant of binahong with Completely Randomized Design (CRD). The leaf explants were planted on MS media with different 2,4-D concentrations (1;2;3 ppm), 0,5ppm IBA+0,5ppm BAP; 0,5ppm IBA+1,0 ppm BAP; and 1,0 ppm IBA+0,5 ppm BAP, each with 15 repetitions. The result showed that the addition of 2,4-D (1 and 2 ppm) was able to induce callus from Binahong leaves on 3 and 5 days after planting, and also 10 days after planting in the controlled and combination treatment. In the 2,4-D media (1 and 2 pm), the callus produced were watery white and compact, while in the 3 ppm 2,4-D media the callus were white and friable. In the media with a combination of BAP and INA the callus were green and compact. The highest average diameter of the callus after 8 weeks in the 1 ppm 2,4-D media reached 2.07 cm followed by the 2 ppm and 3 ppm 2,4-D media producing a diameter of 1.8 cm. In the combination media (BAP and IBA), the callus diameter was less than 0.3 cm. The highest percentage of callus formed was in the media MS+1 ppm 2,4-D and a combination of MS +0,5ppm IBA+0,5ppm BAP that reached 100%. The lowest was found in the control (MS) which reached only 20%. The optimum growth of callus was at 3 weeks and after  that it declined or stayed stagnant. The result of the analysis of variance (ANOVA) showed that there was no significant difference in the media used in this research. Key words: induction, binahong leaf, callus, plant growth
A Study of Partial Least Squares (Case Study: Cox-PLS Regression) Retno Subekti; Rosita Kusumawati
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (160.247 KB) | DOI: 10.21831/jsd.v3i1.2792

Abstract

Indication of multicollinearity in regression analysis will lead to wrong interpretation when interpreting the results. One of the handling of the case of multicollinearity is to use of PLS (partial least squares). The purpose of this study is to provide a general overview of PLS. The results of this study are in general PLS study along both the concept and the classification methodology and its application. PLS is generally divided into two branches, namely PLS regression and path analysis. In the application of PLS, the data used TB patient survival (tubercolosis) in Yogyakarta, which is obtained from a private hospital in Yogyakarta. The data were analyzed using Cox regression, but there is multicollinearity so then there is an error in the interpretation of the significance of the model. By using PLS-Cox regression, we obtained one PLS component consisting of one independent variable, namely class care.   Key words: PLS regression, PLS path modelling, Cox regression
The effect of foliar fertilizer dosage variations to the growth and productivity of some fruit vegetables exposed to manipulated grasshopper sound Ratnawati Ratnawati; Agus Purwanto; Budiwati Budiwati; Suratsih Suratsih; Rahma Ayu Maharani; Decy Lukitasari
Jurnal Sains Dasar Vol 3, No 1 (2014): April 2014
Publisher : Faculty of Mathematics and Natural Science, Universitas Negeri Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (556.251 KB) | DOI: 10.21831/jsd.v3i1.2794

Abstract

The study aims to investigate the optimal dosage of foliar fertilizer to the growth and productivity of  some fruit vegetables exposed to manipulated grasshopper sound  on the frequency of 4500 Hz. “Intan” variety tomato,“Kresna” variety chili and “parade tavi” variety snake bean was treated in 6 dosages of foliar fertilizer, This research is an experimental research using randomized blok design conducted from December,2012 to October, 2013 at Rowobayem, Kabupaten Purworejo, at Ngalas, Kabupaten Klaten, and at Kricaan, Mesir,  Salam Kabupaten Magelang. Parameters measured were the area of stomatal opening, leaf area, plant fresh weight, plant dry weight and the yield. Research results show that there is  a significant effect of dosage variation of foliar fertilizer on tomato plants  on the plant fresh weight, plant dry weight, and tomato weight; on chili plants  on leaf fresh and dry weight, dry weight of leaf and chili weight. Meanwhile,  the optimal dosage of foliar fertilizer for tomato plants is 1.75 cc/l, for chili plants is 1.25 g/l and that for snake bean plants is 1.25 g/l. Key words: sound wave, chili, tomato, snake bean, growth  

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