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Jurnal Penelitian Saintek

saintek
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Published by Universitas Negeri Yogyakarta

ISSN : 14123991 EISSN : 25287036 DOI : 10.21831

Core Subject : Science,

Decision Sciences, Operations Research & Management

Arjuna Subject : -

Articles 286 Documents

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APPLICATION OF NISBAH FUNCTION IN ELECTRODYNAMICS Bambang Ruwanto; Maryanto Maryanto
Jurnal Penelitian Saintek Vol 7, No 1: April 2002
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Analyzes about characteristics of quotient function Q(x) = (1- x)/(l + x) have been done, where x was scalar variable. The result of the analyzes showed that quotient function had inverse character and it can be developedfor two variables of multiplication or more. Application of quotient function in electrodynamics for calculation of reflection coefficient on reflection wave on boundary plane produces simpleformulation for r TE and r TM. The result is very useful, because mathematics calculation can be done easily.

DETERMINATION OF GAS-CONDENSATED FACTORS BASED ON COMPOSITION WITH NEWTON-RAPHSON ITERATION METHOD Supahar Supahar
Jurnal Penelitian Saintek Vol 6, No 1: Saintek 2001
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

The purpose of this research was to determine z-factor of gascondensate system using an iterative Newton-Raphson method to solve the Soave-Redlich-Kwong cubic equation of state (SRK CEOS). In this study, some influencingfactors were observed, i.e., compositions of hydrocarbon, temperature, and pressure of the gas condensate system. The research method involves determination process of the Hepthane plus characteristic. i.e. Critical Temperature of C7+ (T; C7+), critical pressure of C7+ (PcC7+). and acentricfactor of Cv; (COC7+) using Riazi and Duabert equation; and the flash liberation process to determine the compositions of hydrocarbon gas at certain pressure (P) and temperature (T). Comparison of the z-factors calculated using Newton-Raphson method to solve the SRK-CEOS with modified Dranchuk Abou-Kassem equation and Standing-Katz method yield an average different of 0.3419 percent and 1.13 percent.

TiO2 DISPERSION TO IN SiO2-MONTMORILLONIT: EFFECT OF PRECURSOR TYPE Is Fatimah
Jurnal Penelitian Saintek Vol 14, No 1: April 2009
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Dispersion of titanium dioxide into montmorilonite pillared silica (SiO2-montmorillonite) was performed in order to gain homogeneous dispersion of TiO2 in solid support having high specific surface area, thermal stability and chemical stability. In this research, effect of titanium precursor to the physicochemical character of material was studied. Three different precursors : TiCl4, TiOCl2 and titanium tetraisopropoxide (TTIP) were dispersed on SiO2-montmorillonite at the concentration of 5% followed by calcination at 400oC for 3 h. Evaluation on material character was studied based on XRD, surface area analyzer and spectrophotometer Diffuse Reflectance UV-Visible (DRUV-Vis) measurements.Result of research show that there is a strong dependency between material properties and tittanium precursor. By three kind of precursors, it can be concluded that main factor playing role in determination of dispersion homogeneity is pH of the system in that TiCl4 cause structure delamination of SiO2-montmorillonite. Based on physicochemical characters, it can remarkably concluded that the success of dispersion by variation of titanium precursors as follow: TTIPTiOCl2TiCl4 .

TESTING OF PROCESSING OIL WASTE TO BE BIODIESEL AS A FUEL ALTERNATIVE MOTOR DIESEL Dwi Widjanarko; Abdurrahman Abdurrahman; Hadromi Hadromi
Jurnal Penelitian Saintek Vol 15, No 1: April 2010
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

The objectives of this research are to desain and to test the biodiesel processing unit from waste cooking oil, to examine the characteristics of processed biodiesel, and to apply the biodiesel on diesel engine to ensure that there will not be a problem on the tested diesel engine. This research is an experiment research carried out by several steps, designing waste cooking-biodiesel processing unit, examining the characteristics ofbiodiesel made, and applying the biodiesel on diesel engine. The result showed that the biodtesel processing unit that was made could work well to produce biodiesel. The biodiesel characteristics are comparable with diesel oil and the biodiesel is applicable on diesel engine without any problems accured. Keywords: biodiesel, waste cooking oil, alternative fuel, diesel engine

THE EFFECTIVENESS OF NATURAL ZEOLITE AS METAL ABSORBENT COPPER(II) IN POOL WATER WITH COLOUMN ADSORPTION METHOD - Suyanta; Cerry Reggiani Catri
Jurnal Penelitian Saintek Vol 21, No 2: Oktober 2016
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

This study was aimed at separating copper(II)ions contained in the pool water by coloumn adsorption method. The coloumn was ﬁ lled up with natural zeolite taken from Gunungkidul. The inﬂ uence of zeolite size in particular contact time toward the effectiveness of the zeolite to adsorb metal ions of copper (II) ions were studied in this research. The effectiveness of zeolite adsorption was based on the efﬁ ciency value which is the ratio between the concentration of metal ions of copper (II) adsorbed by the metal ion concentration of copper (II) prior to adsorption. Copper metal ion concentrations were determined using Atomic Absorption Spectroscopy (AAS). The results show that the ability of the column adsorption system in the separation of metal ions of copper (II) was quite high. Column with zeolite 1 (size 10 mesh) can lower copper consentration up to 37.1698%, while the zeolite column 2 (size 5 mesh) can lower the consentration up to 35.9976%. These results indicate that the copper ions in the pool water can be separated quite well.

MODIFICATION OF CONVENTIONAL CONFLICTING SYSTEMS INTERNATIONAL EQUIPMENT Hendrik J.R. Sumarauw
Jurnal Penelitian Saintek Vol 17, No 1: April 2012
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Modifikasi sistem pengapian konvensional menjadi pengapian elektronik telah diselidiki. Tujuan penelitian adalah untuk mendapatkan sistem pengapian konvensional menjadi sistem pengapian elektronik sehingga daya motor lebih optimal dan menghemat konsumsi bahan bakar. Pengumpulan data dilakukan dengan observasi langsung di lapangan (mesin 5-K) dan kemudian membuat rangkaian modifikasi sistem pengapian. Hasil penelitian menunjukkan bahwa transistor bekerja dengan mengirim dan menerima signal pengapian menjadi lebih tepat dan menghasilkan daya yang efektif. Sudut dwell yang semakin besar menghasilkan pengapian dan daya yang maksimal besar karena persentase arus primer yang mengalir semakin lama. Daya motor semakin meningkat dengan meningkatnya putaran mesin karena banyaknya langkah kerja yang dilakukan oleh torak dalam waktu yang sama tetapi terbalik dengan waktu sudut dwell.Kata kunci: Konvensional, pengapian, elektronik, hemat bahan bakar

THE CHLOROFORM EXTRACT OF SOURSOP (ANNONA MURICATA LINN) LEAVES AS ANTIBIOTIC TOWARDS PROPIONIBACTERIUM ACNES Dian Riana Ningsih
Jurnal Penelitian Saintek Vol 22, No 2: Oktober 2017
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

Propionibacterium acnes (P. acnes) was bacterium commonly found in acne. P. acne was microaerophilic bacterium which can be as a normal fl ora as inhabitants of skin but also is a facultative pathogen. Soursop was a plant that can be used for acne, wounds ulcers, convulsions, and lice cure. This study was aimed to determine the antibacterial activity of soursop leaves against P. acnes bacteria using chloroform solvent. Antibacterial activity test was performed by well diffusion method. The inhibition activity of soursop leaves chloroform extracts was indicated by the appearance of clear zone. The results show that the extract of chloroform at a concentration of 1000, 2000, 3000, and 4000 ppm is able to inhibit the growth of P. acnes bacteria with the inhibition zone of 8.86, 12.12, 12.42, and 15.48 mm respectively. The greater the inhibition zone, the higher the concentrations of n-hexane extract of the soursop leaves.

DYNAMICS SYSTEM ANALYSIS AND MODELING ON CRANE BRAND THREE DIMENSIONS (3D) WITH LOADING COSTS Moh Khairudin
Jurnal Penelitian Saintek Vol 18, No 2: Oktober 2013
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

This paper presents the development of a dynamic modelling of a three-dimensional (3D) crane with payload. A 3D crane with simultaneous travelling, traversing, and hoisting is considered. The dynamic equations of motion of the crane system are derived using the Lagrange’s method and represented in nonlinear differential equations. Simulation is performed using Matlab/Simulink to investigate the dynamic behaviour of the system both in time and frequency domains. System responses including positions of rail, trolley and payload, and payload sway angle are obtained and analyzed. The results show for sway angle, exhibits significant and persistent sway angle of ±0.09 rad. On the other hand, the sway angle, shows a significant initial sway angle of ±0.07 rad. Then the system coscillates with a persistent angle of ± 0.009 rad.

THE EFFECT OF MICRO PARTICLE STEEL SLAG TOWARDS PHOSPOROUS AND HYDROGEN ON ANDISOLS Rosi Rosidah; Rina Devnita; Ridha Hudaya; Rachmat Haryanto
Jurnal Penelitian Saintek Vol 23, No 2: Oktober 2018
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

This study was aimed at determining the effect of steel slag micro particles on Phosphorus (p), p-available retention and interchangeable Hydrogen (h-dd) on Andisol. The material used in this study was Andisol and steel slag. The Andisol was obtained from PTPN VIII-Ciater tea plantations (1250 m asl) on the eastern slope of Tangkuban Perahu Mountain, Subang, West Java. The steps taken were soil sampling using disturbed soil extraction methods using Minipit technique, soil sample filtering, weighing, mixing soil samples with steel slag from PT Krakatau Steel Serang, refining done using the Top-Down method, incubating and then analyzing properties soil chemistry. The chemical properties of the soil analyzed were P, P-available and H-dd retention. P retention was analyzed by the Blackmore method, P-available was analyzed using the Bray I, Bray II, and Olsen methods. H-dd was analyzed by the Titration method. The data obtained were then carried out statistical tests with variance analysis (ANOVA) with RAL environmental design and Duncan test. The results showed that the micro-application of steel slag particles had an effect on available P and P retention but had no affect on H-dd.PENGARUH PARTIKEL MIKRO TERAK BAJA TERHADAP RETENSI FOSFOR DAN HIDROGEN PADA ANDISOLPenelitian ini bertujuan untuk mengetahui pengaruh partikel mikro terak baja terhadap retensi Fosfor (p), p-tersedia dan Hidrogen dapat dipertukarkan (H-dd) pada Andisol. Bahan yang digunakan dalam penelitian ini adalah andisol dan terak baja. Andisol didapat dari perkebunan teh PTPN VIII-Ciater (1250 m dpl) pada lereng bagian timur Gunung Tangkuban Perahu, Subang, Jawa Barat. Tahapan yang dilakukan adalah pengambilan sampel tanah menggunakan metode pengambilan tanah terganggu dengan teknik minipit, penyaringan sample tanah, penimbangan, pencampuran sampel tanah dengan terak baja yang berasal dari PT Krakatau Steel Serang, penghalusan yang dilakukan dengan metode Top-Down, penginkubasian dan kemudian penganalisaan sifat kimia tanah. Sifat kimia tanah yang dianalisi adalah retensi P, P-tersedia dan H-dd. Retensi P dianalisis dengan metode Blackmore, P-tersedia dianalisis menggunakan metode Bray I, Bray II, dan Olsen. H-dd dianalisi dengan metode titrasi. Data yang didapat selanjutnya dilakukan uji statistik dengan analisis sidik ragam (Anova) dengan rancangan lingkungan RAL dan uji Duncan. Hasil penelitian menunjukkan bahwa Aplikasi mikro partikel terak baja berpengaruh terhadap retetnsi P dan P-tersedia tetapi tidak berpengaruh terhadap H-dd.

SITOTOXIC TESTS OF SOME MONO COMPONENTS OF COCON HYDROXES ON CANCER CELL LINE T47D Retno Arianingrum; Indyah Sulistyo Arty; Sri Atun
Jurnal Penelitian Saintek Vol 16, No 2: Oktober 2011
Publisher : Institute of Research and Community Services, Universitas Negeri Yogyakarta

The aim of this research was to study cytotocix activity from some mono para hydroxy compounds (MPHC) i.e. MPHC A, MHPC B, MPHC MPHC D, and MPHC E against T47D cancer cell lines. Those compounds were synthesized from benzaldehyde derivatives and acetofenon derivates through cross aldol reaction under acid condition. Separation and purification of these compounds were conducted by recrystallization technique using suitable eluent. Identification and structure elucidation was done by comparing the data of thin-layer chromatography (TLC) with marker (compounds that have been found previously), and also used the data of IR spectrum. Each compound then was performed cytotoxicity test by in vitro against T47D cells using MTT assay. Observation of cell morphological changes was observed using phase contrast microscopy. The results showed that the compound MPHC A, MPHC B, MPHC C, and MPHC D had cytotoxic activity against T47D cancer cell line, while the compound MPHK E did not have cytotoxic activity. The highest toxicity was MPHK A with LC50= 66.44 Pg/mL. The presence of hydroxyl groups contributed to the enhancement of cytotoxic effect.

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