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All Journal ASEAN Journal of Systems Engineering EKSAKTA: Journal of Sciences and Data Analysis English Review: Journal of English Education Chimica et Natura Acta Indonesian Journal of Chemistry IJCER (International Journal of Chemistry Education Research) JKPK (Jurnal Kimia dan Pendidikan Kimia) IJCR (Indonesian Journal of Chemical Research) Khazanah: Jurnal Mahasiswa

Riyanto Riyanto

Chemistry Department, Universitas Islam Indonesia

Author-ID : 4303704

Religion Agriculture, Biological Sciences & Forestry Arts Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Economics, Econometrics & Finance Education Electrical & Electronics Engineering Engineering Environmental Science Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mechanical Engineering Medicine & Pharmacology Public Health Social Sciences

Published : 17 Documents Claim Missing Document

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IMPACTS OF CLASSROOM’S MOBILE LEARNING: CAN SMARTPHONE SUPPORT STUDENTS’ COLLABORATION? Didik Rinan Sumekto; Riyanto Riyanto; Avin Fadilla Hilmi; Nursyabani Purnama
English Review: Journal of English Education Vol 8, No 1 (2019)
Publisher : University of Kuningan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25134/erjee.v8i1.2146

The trend of facilitating technological devices for students in the classroom still becomes controversial among teachers, whether these devices can be effectively applied or conversely. This study aims at revealing students’ collaboration effectiveness using smartphones. 528 teachers of primary and secondary schools in Sleman District, Indonesia involved as the respondents. Data collection used self-rated questionnaire indicating teachers’ perceptions and was analyzed by descriptive and factor analysis tests. The results confirmed that learning and discussion with peer, comfortableness with learning activity, dynamic learning atmosphere, mutual appreciation when giving feedback, mutual respect with peer, and collective usage encourages a good habit of learning descriptively engaged students’ collaboration effectiveness, whereas one factor, peer’s social relationships with teachers gain better showed its ineffectiveness. Further, the principal component sequentially adjudged the position of seven perceived factors with the Eigenvalue and the factorial analyses affirmed two rooted components with a total factor of 72.97%, where component 1 gained 67.16% and component 2 gained 5.81%. Using smartphones coherently need an exploration and an engagement through the social mechanism to support students’ learning activities.

Pengolahan Limbah Industri Tekstil Berbasis Green Technology Menggunakan Metode Gabungan Elektrodegradasi dan Elektrodekolorisasi dalam Satu Sel Elektrolisis Zaina Rohayati; Mega M. Fajrin; Jumardin Rua; Yulan Yulan; Riyanto Riyanto
Chimica et Natura Acta Vol 5, No 2 (2017)
Publisher : Departemen Kimia

Limbah tekstil mengandung berbagai bahan kimia berbahaya jika langsung dibuang ke lingkungan. Metode lain penanganan limbah memiliki kelemahan yaitu menghasilkan banyak lumpur, serta biaya operasional yang mahal. Metode penanganan limbah cair yang lebih menguntungkan adalah elektrolisis yang merupakan metode ramah lingkungan karena tidak memerlukan bahan kimia tambahan. Pada metode elektrolisis degradasi anode akan mudah terjadi sehingga mengurangi konsentrasi senyawa organik (elektrodegradasi) dan kepekatan warna limbah (elektrodekolorisasi). Penelitian ini terdiri beberapa tahap, yaitu analisis komposisi elektrode, elektolisis limbah tekstil pada variasi waktu serta analisis persentase degradasi dan penurunan nilai Kebutuhan Oksigen Kimia (COD) limbah tekstil secara spektrofotometri. Hasil penelitian menunjukkan bahwa elektrode stainless steel memiliki komposisi kadar besi (72,2%), krom (18,9%), nikel (7,6%) dan silika (1,4%). Setelah dielektrolisis pada variasi waktu dan analisis persentase degradasi secara spektrofotometri didapatkan waktu optimum selama 60 menit dengan degradasi sebesar 98,56%. Persentase penurunan nilai COD limbah tekstil yang dielektrolisis pada waktu optimum adalah sebesar 50,3834.

ISOLASI, IDENTIFIKASI DAN PEMURNIAN SENYAWA 1,8 SINEOL MINYAK KAYU PUTIH (Malaleuca leucadendron) Rizqi Helfiansah; Hardjono Sastrohamidjojo; Riyanto -
ASEAN Journal of Systems Engineering Vol 1, No 1 (2013): ASEAN Journal of Systems Engineering
Publisher : Master in Systems Engineering

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (403.54 KB)

Cajuput oil is one of the essential oils that widely used as materials for medical or pharmaceutical products, this makes the cajuput oil become the most wanted products in essential oils industries. Cajuput oil demand is currently increasing with the growing variety of utilization of cajuput oil. Cajuput oil productions in Indonesia run into fluctuations and tend to decrease. There are several factors that affect production and quality of cajuput oil, and one of them is distillation technique. Moreover fractionation or isolation of the 1,8-cineol compound also have not been done by the cajuput oil entrepreneurs, whereas this is important in order to use 1.8 cineol compound further.Distillation of cajuput leaves is done by three distillation methods, namely water distillation, water steam distillation and steam distillation. Calculating the yield after cajuput oil obtained and then testing the physical and chemical properties of cajuput oil in accordance with the Indonesia National Standard (SNI 06-3954-2006). And then doing fractionation of cajuput oil to obtain at least 85% 1,8 Cineol compound. The results showed that water steam distillation method produces the highest yield, the yield is 2.5%, followed by water distillation method, the yield is 1.8% and then steam distillation method, the yield is 1.5%. Physical and chemical properties that exist on cajuput oil that produced by water and steam distillation method and steam distillation method are appropriate with the Indonesia National Standard. After doing fractination processes for two time, the fractination process produced 1.8 cineol compound 79.90% in first fraction, 87.90% at second fraction and then 89.78% at third fraction.

STUDI PERBANDINGAN PERLAKUAN BAHAN BAKU DAN METODE DISTILASI TERHADAP RENDEMEN DAN KUALITAS MINYAK ATSIRI SEREH DAPUR (Cymbopogon citratus) Slamet -; Supranto -; Riyanto -
ASEAN Journal of Systems Engineering Vol 1, No 1 (2013): ASEAN Journal of Systems Engineering
Publisher : Master in Systems Engineering

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (469.769 KB)

Indonesia is rich in plant biodiversity. Indonesia volatile oil development efforts through increased development of one plant of lemon grass, which is one of the essential oil producing plants known as Cymbopogon citratus. Lemongrass essential oil in the chemical industry used as raw materials in the manufacture of cosmetics, perfume, deodorant, deodorant soap, floor cleaners and detergents.The purpose of this study was to determine the highest yield of lemongrass essential oil distillation using the method of water distillation, water-steam, and steam to the treatment of intact leaves and chopped leaves and know the quality of essential oil of lemongrass with the treatment of raw materials and different methods of distillation, the design used by two factors: variation in the treatment of raw material (whole leaves and chopped leaves) and the distillation process variation (distilled water (boiled), water-steam distillation and steam distillation. Data obtained from the analysis of yield, specific gravity, refractive index, and oil content of the compound citral essential (lemongrass oil).This study uses three methods of distillation, the distillation of water, water-steam distillation and steam distillation is carried out on samples of intact leaves and chopped leaves of fresh lemongrass. The results yield calculation and testing of physics and chemistry, as well as in the method of analysis SPSS One-Sample Test Statistics for the lemongrass essential oil products.Based on the results of research on the treatment of raw materials and distillation methods can be concluded that the treatment of raw materials lemongrass intact leaves with water distillation method (boiled) at both the content yield 0.52%, 71.84% citral, specific gravity 0.8967 g/mL, and the refractive index of 1.4905. It is appropriate to mention that SNI 06-39-53-1995 yield 0.3%, the specific gravity of 0.8731 g/mL, and the refractive index of 1.4586. But the content of citral not meet SNI standards are 76.1%, but according to Guenther (2006) which states citral content of between 65% to 85%.

Determination of Lead in Waste Water Using Cyclic Voltammetry by Platinum Wire Electrode Riyanto Riyanto
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.art3

Determination of lead in waste water using cyclic voltammetry by platinum wire electrode has been carried out. The cyclic voltammetry method was performed in a three electrodes system using platinum wire as a working electrode, an Ag/AgCl (saturated KCl) as reference electrode and platinum plate as the counter electrode. PGSTAT 100 N 100 V/250 mA type (Metrohm Autolab) was used for electroanalysis measurements. Electroanalysis of lead in waste water was performed in 0.1 M KClas an electrolyte. From this research showed that the developed electroanalysis lead in waste water using platinum wire electrode are accurate, precise, reproducible and inexpensive with acceptable correlation of determination (R2 = 0.999), LOD = 0.9029 mg/L , LOQ = 3.0098 mg/L and recovery = 100,67%. The methods can be used for the analysis of lead in waste water. This method is simplicity of sample preparation and use of low cost reagents are the additional benefit.

A Highly Sensitive Electrochemical Glucose Sensor By Nickel-Epoxy Electrode With Non-Enzymatic Sensor Riyanto Riyanto
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 16, ISSUE 1, February 2016
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol16.iss1.art1

The preparation of new sensor for glucose was based on the fact that glucose can be determined by non-enzymatic glucose oxidase. The Ni metals (99.98% purity, 0.5 mm thick, Aldrich Chemical Company) was used to prepare Ni-Epoxy electrode. The Ni-epoxy electrodes were prepared in square cut of 1 cm and 1 mm by length and wide respectively. The Ni metal electrodes were connected to silver wire with silver conducting paint prior covered with epoxy gum. The prepared of nickel-epoxy modified electrode showed outstanding electro catalytic activity toward the oxidation of glucose in alkaline solution. The result from this research are correlation of determination using Nickel-Epoxyelectrode for electroanalysis of glucose in NaOH was R2 = 0.9984. LOQ, LOD and recovery of the Nickel-Epoxy electrode towards glucose were found to be 4.4 μM, 1.48 μM and 98.19%, respectively. The Nickel-Epoxy wire based electrochemical glucose sensor demonstrates good sensitivity, wide linear range, outstanding detection limit, attractive selectivity, good reproducibility, high stability as well as prominent feasibility use of non-enzymatic sensor for monitoring glucose in human urine owing to its advantages of low cost, simple preparation and excellent properties for glucose detection.

Application of Electro-Oxidation Method for Treatment of Dye Textile Wastewater Using Stainless Steel Electrode: Study of Electrolyte Concentration Effect to Color Removal Jumardin Rua; Mega Maghfirotul Fajrin; Zaina Rohayati; Riyanto Riyanto
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 17, ISSUE 2, August 2017
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol17.iss2.art6

The increasing number of textile industries has created a new problem of environmental pollution from waste produced. Entering of concentrated wastewater that containing of complex organic compounds to agricultural land and rivers has caused loss to humans or the environment. Treatment of dye textile wastewater by electro-oxidation method using stainless steel electrode has been done. This research consists of several stages: analysis of electrode composition with SEM-EDX, electrolysis of wastewater at variation of electrolyte concentration and analysis of electrolyte concentration effect to color removal percentage of wastewater. The result shows that the electrode composition consisted of iron, chromium, nickel and silica with the main composition of iron in the amount of 72.2%. After electrolysis on variations of electrolyte concentration and analysis of color removal percentage of wastewater, obtained that the largest of color removal percentage on the use of electrolyte concentration of 3% in the amount of 98.81%

Conversion of Carbon Dioxide to Ethanol by Electrochemical Synthesis Method Using Brass as A Cathode Septian Ramadan; Riyanto Riyanto
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 17, ISSUE 2, August 2017
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol17.iss2.art1

The effect of potential and gas flow rate were investigated to determine the optimum conditions of the electrochemical synthesis process to convert carbon dioxide to ethanol. The conversion process is carried out using a NaHCO3 electrolyte solution in an electrochemical reactor equipped with a cathode and anode. As cathode is used brass, while as anode is used carbon. The result of the electrochemical synthesis process was analyzed by gas chromatography to determine the content of the compounds produced qualitatively and quantitatively. The optimum electrochemical synthesis conditions to convert carbon dioxide to ethanol are potential and gas flow rate are 3 volts and 0.5 L/minutes with ethanol concentration yielded 1.32%.

Preparation and Application of Platinum Composite Microelectrode (PCM) for the Routine Analysis of Acetaminophen in Pharmaceutical Products Riyanto Riyanto; Ahmad Safarudin
Indonesian Journal of Chemistry Vol 14, No 2 (2014)
Publisher : Universitas Gadjah Mada

Preparation and application of platinum composite microelectrode (PCM) for the routine analysis of acetaminophen in pharmaceutical products has been carried out. This electrode was prepare by Pt powder and PVC in 4 mL tetrahydrofuran (THF) solvent and swirled flatly to homogeneous followed by drying in an oven at 100 °C for 3 h. The mixture was placed in 0.5 cm diameter stainless steel mould and pressed at 10 ton/cm2. The cyclic voltammetry were performed in a three electrodes system using PCM as a working electrode, an Ag/AgCl (saturated KCl) as reference electrode and platinum wire as the counter electrode. Electroanalysis of acetaminophen was performed in 0.1 M H2SO4 as an electrolyte. The result of the study showed that the correlation of determination using PCM electrode for electroanalysis acetaminophen was R2 = 0.999. Precision, recovery, LOD and LOQ of the PCM towards acetaminophen were found to be 1.04%, 100.54%, 19.52 mg/L and 65.08 mg/L, respectively. As a conclusion, the methods can be used for routine analysis of acetaminophen in pharmaceutical product. Simplicity of sample preparation and use of low cost reagents are the additional benefit of this method.

ELECTROCHEMICAL OXIDATION OF ETHANOL USING Ni-Co-PVC COMPOSITE ELECTRODE Riyanto Riyanto; Mohamed Rozali Othman; Jumat Salimon
Indonesian Journal of Chemistry Vol 11, No 1 (2011)
Publisher : Universitas Gadjah Mada

The morphological characteristics and electrochemical behavior of nickel metal foil (Ni), nickel-polyvinyl chloride (Ni-PVC) and nickel-cobalt-polyvinyl chloride (Ni-Co-PVC) electrodes in alkaline solution has been investigated. The morphological characteristics of the electrode surface were studied using SEM and EDS, while the electrochemical behavior of the electrodes was studied using cyclic voltammetry (CV). It was found that composite electrodes (Ni-PVC and Ni-Co-PVC) have a porous, irregular and rough surface. In situ studies using electrochemical technique using those three electrodes exhibited electrochemical activity for redox system, as well as selectivity in the electrooxidation of ethanol to acetic acid. The studies also found that an electrokinetics and electrocatalytic activity behaviors of the electrodes prepared were Ni metal foil<Ni-PVC2/NiOOH and Co(OH)2/CoOOH catalysts which were determined by the XPS and cyclic voltammetry studies. A better electrokinetics and electrocatalytic activity behaviors electrodes, gave a better results in the electrooxidation of ethanol in alkaline solution.

Co-Authors Ahmad Safarudin Arum Muliandari Asrina Asfarina Avin Fadilla Hilmi Beta Wulan Febriana Didik Rinan Sumekto Hardjono Sastrohamidjojo Hardjono Sastrohamidjojo Herlena Ary Safitri Is Fatimah Jumardin Rua Jumardin Rua Jumat Salimon Marlia Ferdayanti Marlina Marlina Mega M. Fajrin Mega Maghfirotul Fajrin Mohamed Rozali Othman Noor Fitri Nursya’bani Purnama Rizqi Helfiansah Septian Ramadan Slamet - Supranto - Tatang Shabur Juliantoa Teguh Imam Handoko Wiharti Wiharti Yulan Yulan Yuyun Yunani Zaina Rohayati Zaina Rohayati

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