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Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Andalas Kampus Universitas Andalas Limau Manih Padang 25163
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INDONESIA
Jurnal Riset Kimia
Published by Universitas Andalas
ISSN : 1978628X     EISSN : 24768960     DOI : -
Core Subject : Science,
Chemistry
Arjuna Subject : -
Articles 554 Documents
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EFFECT OF PRE- γ-IRRADIATION DOSE ON THE DURABILITY OF THE SULFONATED ETFE-G-POLYSTYRENE CONDUCTING MEMBRANES Septiani, Upita; Kubota, Hitoshi
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.221

Abstract

The influence of pre-g-irradiation dose on durability of the poly(ethylene-co-tetrafluoroethylene) (ETFE) film-based radiation-grafted polymer electrolyte membrane was investigated. The durability of membrane was found to be strongly influence by g-ray pre-irradiation dose. The durability was tested in a 3% H2O2 aqueous solution at 60°C. The durability of the polymer electrolyte membrane with a degree of grafting of about 30% prepared by lower pre-irradiation dose was more stable than that of the membrane prepared with higher pre-irradiation dose.
PENGGUNAAN FRONTIER ORBITAL MOLEKUL SEBAGAI DESKRIPTOR PADA ANALISIS HUBUNGAN KUANTITATIF STRUKTUR AKTIVITAS (HKSA) TOKSIK SENYAWA KHLOROFENOL Emdeniz, -
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.211

Abstract

Quantitative structure-activity relationship (QSAR) methods have been applied to prediction of the toxicity of certain chemical compound. In this research a QSAR descriptor used frontier molecular orbital (LUMO energy (EL), HOMO energy (EH), and band gap (ΔE) and its derivatives were obtained from density functional theory (DFT) (chemical hardness (η) chemical potential (μ) or absolute electronegativity (χ) and global electrophicility indeks (ω)). Frontier molecular orbital (EL and EH) was calculated by ab initio quantum methods. This research found the correlation between the experimental ecotoxicological data of chlorophenols and toxicity prediction were calculated based on the best QSAR equation model of all equation model which have been studied. The best QSAR equation model using parameter LUMO energy (EL), and global electrophilicity index (ω) as descriptor on QSAR toxic of chlorophenol compounds against Bacilus sp TL81 is - log IC50 = 11,022 - 1,767 EL - 5,687 ω, and it has the coefficient of determination (R2) = 0,581 and standard deviation (SD) = 0,6111.
PENGOLAHAN LIMBAH POLIPROPILEN MENJADI BAHAN BAKAR CAIR MELALUI METODE PIROLISIS Bemis, Restina; Jamarun, Novesar; Arief, Syukri
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.217

Abstract

Plastics become the biggest environmental problem when it accumulate in landfills because its non-biodegradable properties. To handle the problems, the plastics were processed to produce liquid fuels by means pyrolysis method which was in this case with and without a catalyst. In this work, polypropylene was used as a precursor and SiO2, zeolites, CaO, Fe as catalysts. FTIR spectrum of pyrolized polypropylene with and without catalysts both have shown C = C functional group at 1648 cm-1. GCMS analysis confirmed the availability of chain length of hydrocarbon between C7 -C27 which is mixture of kerosene and diesel fractions. Catalysts can lower the temperature and time reaction of pyrolysis process as they increase rendement (%) of product. Liquid fuels that produced from polypropylene pyrolysis without catalyst was 72.06%, and with catalysts were 79.59% (SiO2), 74.76%, (zeolite), 76.80% (CaO), and 76.83% (Fe).
PENARIKAN ION Cu2+ (CuSO4) DARI LARUTAN AIR MELALUI PROSES ELEKTROLISIS SECARA FOTOVOLTAIK DENGAN SEMIKONDUKTOR LAPISAN OKSIDA CuO DAN ZnO DARI KUNINGAN Alif, Admin; Suyani, Hamzar
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.222

Abstract

Photovoltaic is a method that can convert sunlight energy into electrical energy. One use ofphotovoltaic electrolysis can be used for metal ions contained in the liquid waste. The research aims electrolyzing Cu2+ ions from aqueous solution using a series of photovoltaic cells with semiconductor CuO and ZnO oxide layer of brass with Na2SO4 electrolyte. The series of photovoltaic cells is associated with an electrolysis cell containing Cu2+ ions to be electrolysed. Semiconductor electrodes made with brass burning in a furnace in a few repetitions at a temperature of 400°C for 1 hour. U-shaped electrolysis cells glass tube containing a solution of CuSO4 1.25 g/L using a carbon rod as anode and cathode. Electrolysis of Cu2+ ions results were analyzed by Atomic Absorption Spectrofotometer (AAS). The results showed that the optimum conditions Na2SO4 electrolyte concentration 0.8 N with semiconductor double-furnace with a strong current 0.829 mA and a voltage of 0.241 mV, the value of efficiency of conversion of solar energy into electrical energy is 0.599%. Electrolysis of Cu2+ ions for 4 weeks could reduce Cu2+ ions concentration of 35 mg/L to 15.909 mg/L (45.45%). CuO and ZnO electrodes was relatively less stable and cause strong currents and voltage drop along the length of the process.
PEMBUATAN KOMPOS DARI LIMBAH PADAT (SLUDGE) PABRIK PULP DAN PAPER Sembiring, Maria Peratenta; Irianty, Rozanna Sri
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.213

Abstract

One of the method to use pulp and paper mill sludge was convert it become a compost. This research result showed that time variation of compost have different physical and organic matter properties. In physical properties, 3 months of compost had 12.57% moisture content, while organic matter contain 10.56% carbon, 1.07% nitrogen, and 9.87 C/N ratio. For 4 months compost had 6.79% moisture content, 11.88% carbon, 0.91% nitrogen, and 13.05 C/N ratio. Nutrients content from both composts appropriate with the standard value of National Standarisation Body.
PENGARUH KONSENTRASI INHIBITOR EKSTRAK DAUN GAMBIR DENGAN PELARUT ETANOL-AIR TERHADAP LAJU KOROSI BESI PADA AIR LAUT Irianty, Rozanna Sri; Sembiring, Maria Peratenta
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.218

Abstract

The important properties to overcome the corrosion are safe, available, biodegradable, low cost, and environmental friendly. Gambier leaves extract is one of the inhibitor that have environmental friendly properties. This study aims to determine the effectiveness of extract using ethanol-water to reduce the corrosion rate. Soaking of ferrous iron plate samples in seawater media have done for corrosion test. Agitator and aerator motors at turn-on and conducted a series of immersion with varying contact time 5, 10, 15, and 20 days. After the time up next ferrous iron plate samples were cleaned, dried, and weighed. Experiment was repeated by adding a inhibitor heavy leaves gambier extract with varying leaves gambier extract, 1000, 3000, and 5000 ppm. Soaking iron plate samples performed at varying pH at 3(acid), 6 (netral), and 9 (alkaline). Calculation is then performed and the rate of corrosion inhibition efficiency gambier leaves extract with ethanol-water solvent. On the immersion of iron plate without inhibitor, the result that the longer the contact time, the weight of the iron plate was reduced. The results showed the addition of inhibitors of leaves extract gambier with ethanol-water solvent into the corrosive media can reduce the rate of corrosion. Inhibitor of leaves extract gambier using ethanol-water solvent effective to reduce the rate of corrosion inhibitor at a concentration of 5000 ppm and contact time of 20 days with the lowest value of the corrosion rate is 0.000503 g/cm2 days in seawater media at initial pH 7.9. Gambier extracts gave greatest inhibition efficiency about 60.345% obtained at a concentration of 5000 ppm inhibitor and 20 days contact time.
PENENTUAN TINGKAT KANDUNGAN AMONIAK, NITRIT, DAN NITRAT PADA REMBESAN SAMPAH LOKASI PEMBUANGAN AKHIR (LPA) AIR DINGIN KOTA PADANG Zilfa, -; Zulfarman, -; Hariyanti, -
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.223

Abstract

Determination of amoniac, nitrite, and nitrate content in seepage waste water in landfill area in cold water, Padang have been done using spectrophotometric method. Sample took from sequencing ofseepage waste water treatment process. The results showed that the ammonia, nitrite, and nitrate content in seepage waste water were 137.612 to 400.298 mg/ L, 0.34 to 0.756 mg/ L, and 0.682 to5.842 mg/ L, respectively. The differences of ammonia, nitrite, and nitrate content in seepage waste water and ammonia and nitrite contents tend to decrease while the nitrate content tends to increase. The rate of ammonia degradation in water seepage was different for each sampling place where the rate of degradation was greatest in seepage water waste treatment II. This degradation is expected to reduce the level of pollution on the environment.
PENGARUH HIDROLISIS ENZIMATIS TERHADAP PRODUKSI BIOETANOL DARI UMBI TALAS (Colocasia gigantea Hook F) Salim, Marniati; Mardiah, Elida; Febrizal, Febby
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.214

Abstract

Umbi talas (Colocasia gigantea Hook F) are rich of starch (77.9%), that could be fermentated to form bioethanol for reneweable energy. The ethanol were produced by fermenting the hydrolised enzymaticly by α-amylase and glucoamylase at the variation 4, 5, 6, 7, and 8 mL for 1, 2, 3, 4, and 5 hours. The glucose produced was measured by Somogy-Nelson methode. The product of hydrolysed were optimum with 6 mL α-amylase and 7 mL glucoamylase for 4 hours wich gave 64,222 g/L of reducing sugar. The product of ethanol were analyzed by Gas Chromatography (GC). The maximum bioethanol production obtained after 5 days fermentation was 4.0123%.
PENGARUH INHIBITOR EKSTRAK DAUN PEPAYA TERHADAP KOROSI BAJA KARBON SCHEDULE 40 GRADE B ERW DALAM MEDIUM AIR LAUT DAN AIR TAWAR Handani, Sri; Elta, Megi Septia
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.219

Abstract

The inhibition effect of Carica papaya leaves exctract on the corrosion of carbon steel schedule 40 grade B ERW in fresh and sea water medium was investigated using weight loss method of monitoring a corrosion rate. The leaves were dried and ground to powder. The extract concentration used was 15%. The inhibition efficiency of 78,49% and 78,63% was obtained in fresh and sea water, respectively. The obtained results indicated that Carica papaya leaves exctract could be used as inhibitor against the corrosion of medium carbon steel in both fresh and sea water.
THE OPTIMATION SIMULTANEUOS DETERMINATION OF LEAD(II) AND CADMIUM(II) BY ADSORPTIVE STRIPPING VOLTAMMETRY (ADSV) -, Deswati; Suyani, Hamzar; Loekman, Umiati; Sari, Nilam
Jurnal Riset Kimia Vol 5, No 2 (2012): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i2.198

Abstract

A selective and sensitive adsorptive stripping voltammetric (AdSV) method for simultaneous determination of lead(II) and cadmium(II) were proposed. The aim of this study was to get the optimum condition for simultaneuos determination of lead(II) and cadmium(II). The parameters were studied such as: variation of accumulation potential, accumulation time, pH, and variation ofcalcon concentration. In this case, the optimum conditions were reached at accumulation potential –0.7 V, accumulation time 80 s, concentration of 0.12 mM calcon, and pH 7.0. At the optimumconditions the relative standard deviation were 2.90% and 1.46% for Pb(II) and Cd(II) respectively for eight replicates (n = 8) measurements. The method was applied for the direct determination of Pb(II) and Cd(II) in sea water around Bungus, Padang City. Concentration Pb(II) and Cd(II) insample were 9.918 μg/L – 27.320 μg/L for Pb(II) and 7.997 μg/L - 32.521 μg/L for Cd(II), with recovery of 99.48%, and 103.28 for Pb(II), and Cd(II) respectively.

Page 15 of 56 | Total Record : 554

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