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The aim of this study is to utilize fly ash from various sources on chemical and physical properties of cement type I (OPC). Utilization of fly ash can improve the strengthness of the cement. It can reduce the waste of fly ash by utilization into cement process. The procedure has been carried out on cement type I (OPC) with the addition of fly ash additives from various sources with concentration variations such as 10% and 20%. Utilization of fly ash as additives substance in cement works to improve the quality of cement. The main parameter in determining the quality of cement is determined by the compressive strength. The results of the compressive strength test showed that the addition of fly ash with a concentration of 10% had a higher effect on the compressive strength than the addition of a concentration of 20%. 5 types fly ash from various sources, fly ash from PT Sinar Mas gives greater compressive strength at 28 days. the addition of fly ash additives to OPC cement mixture has chemical and physical properties which are not much different from properties of PCC cement.

The Modified Phenanthroline Method (MPM) has been validated for determination of antioxidant content in herb samples. Validation was done using Relative Standard Deviation (RSD) and percentage of recovery. The RSD and percentage of recovery for herb samples are 3.13% and 98.6%, respectively. Based on these values, MPM method is valid for determining antioxidant content in herb samples. T test shows no significant differences of antioxidant content using any of these methods, MPM, PM, FRAP or DPPH, at a 95% confidence level. MPM method shows a very strong correlation with PM and FRAP method. While with DPPH and TPC shows is strong.

The corrosion of steel and its alloys is an important problem in industry, especially in acidic environments. Mild steel is one of the important alloys of iron which has many industrial applications because of its excellent mechanical properties, but mild steel is susceptible to corrosion. Corrosion problems need to be a concern and must be handled properly. Hydrochloric acid is widely used for pickling, cleansing, decomposition and metal etching, on the other hand also contributes to corrosion of metal surfaces. Plant extracts investigated the properties, mechanisms of adsorption and efficiency of inhibition as environmentally friendly corrosion inhibitors for various steel materials in different acidic media. The efficiency of corrosion inhibition of steel from plant extracts analyzed ranged from 72-98% and generally as a mixed-type inhibitor. Most of the inhibitors are adsorbed on the steel surface through a physisorption mechanism.

This research aims to obtain reactor design photocells that can convert light energy into electrical energy space. Room light energy derived from sunlight that comes into the room and fluorescent light irradiation. Photocells reactor using a panel of copper oxide (Cu2O/CuO) of calcined Cu plate and filler electrolyte Na2SO4 0.5 N. The design of the geometry of the reactor photocells covering thickness of the glass pane, the distance between the electrodes, the interface layer, layer and coating reflector panels, and junction type np used. Reactor photocells 1 (R1) and 2 (R2) is identical in geometry to the thickness of the glass panel 3 mm thick reactor 15 mm without anti reflector, but the difference at the junction of type n, (R1 = plate Cu; R2 = plate Aluminum) generate 182.82 mW/m2 and 21119644.3 NW/m2. Design R3 (junction-type n = plate Cu) and R4 (junction-type n = plate Al), a panel thickness of 15 cm and has a layer anti reflector provide power 214.95 mW/m2 and 24163298.3 NW/m2. Design Reactor 5 (R5 = Cu) and R6 (Al), thickness of 9 mm, the distance between the electrodes 0:30 mm, using anti reflector carbon, giving each the power of 277.36 mW/m2 and 31258420.91 NW/m2. The most optimum reactor design is the design of R6 with 2:14% conversion capabilities (Intensity = 90.21 foot candles) for the sunlight into the room.

ABSTRACT Determination of kinetic analysis of Co(II) ion transport through bulk liquid membranes by consecutive method have been study. The optimum condition was obtained at pH 4 for the intermediate phase and receiving phase at pH near zero, while the source phase at pH 7, oxine concentration in chloroform at source phase is 2.10 M, methyl red concentration in chloroform at receiving phase is 3.10 M. It was found that Co(II) ion receiving phase at optimum condition as 4.40%. Evaluation of Co(II) ion kinetic transport shows k1 as 0.0116 minutes-1 and k4 0.0113 minutes-1. Kinetic transport process of Co(I1) ion through bulk liquid membranes by consecutive method followed first order consecutive irreversible reaction rate low. Consecutive method can used as an alternative method in determination the optimum condition of metals ion transport and kinetic evaluation of mentioned transport metals ion. Keywords : bulk liquid membranes, consecutive, cobalt

ABSTRACT A research aimed to study the influence of ZnO white powder on photodegradation of methylene blue using Merkuri lamp (l = 365 nm) as light source have been reached. A suspension of ZnO (40 mg) mixed with 25 mL of methylene blue solution (initial concentration of 0.015 mM) then was illuminated for 60 minutes showed degradation and quantum yield amounting 23.84% and 3.55 molecules photon-1, respectively. These results mean that by using ZnO as photocatalyst there is about four times efficiency than the one without ZnO either in case of time consumed or the number of photon applied. In kinetic study, it has been observed that such semiconductor-catalyzed photochemical reaction obeys the first order rule where rate constant and half time consecutively were 0.0029 minute-1 and 231 minutes. Keywords : photodegradation, photocatalyst, quantum yield, semiconductor, photochemical reaction.

ABSTRACT Peat water purification by filtration with perlite-cement-lime mixtures was preliminary studied. The filtration was realized under static condition without any pressure. From the experimental results obtained that perlite composition in the mixture plays an important role in the filtration processing. Otherwise the some physical properties of perlite-cement-lime mixture was also determined. Key words: peat water, perlite.

ABSTRACT Hydrogen is one of the promising alternative energy sources which is environmentally-friendly. Amongs several methods that have been used to produce hydrogen is a photolysis base on photochemical reaction which has been choosen and applied for this work. In this system where water was photolyzed in the present of TiO2 powder as photocatalyst and potassium iodide as sacrificial agent. The sample was prepared by addition various potassium iodide concentrations and then each sample was treated in the present and absent of air. The sample was placed in a quartz reactor which was then illuminated by a Philips low pressure vapoured mercury lamp (λ = 254 nm) as light source for 7 hours. Produced gas volume was measured by a method based on the movement of soap bubbles. The results showed that the maximum gas volume obtained at 0.006 g/L TiO2 and 0.1 g/L KI concentration (in the present and absent of air) were applied. Furthermore, the maximum volume of hydrogen gas was produced at the present of air. In the present of air, dissolved oxygen accelerated H2 gas productions which act as oxidation agent and electron carrier to H+. Keywords: Photolysis, Photocatalyst, Titania, Hydrogen, Sacrificial agent

ABSTRACT The research about bio-filtration of peat water using paddy chaff coated by carbon as filter biomaterial has been conducted. Iodimetry titration method was selected for determination of BOD and COD concentration, while gravimetry method and UV/Vis spectrophotometry is used to determinate TSS and humic acid containing in sample. The results of filtration with bio-filter lock up this paddy able to reduce organic compounds in peat water. The existence of coating carbon causing of BOD 22.37 mg/L (without carbon 27.73 mg/L), COD 54.30 mg/L (without carbon 86.02 mg/L), TSS 120 mg/L (without carbon 155 mg/L) concentration was decreasing, especially at the third step of filtration. Keywords : peat water, biofiltration, biomass

Vol 5 No 1 ABSTRACT The roselle flower and mangosteen pericarp dyes were applied as dye sensitizer for dye-sensitized solar cell. The solar cell was composed of a thin film TiO2 as working electrode, 2B pencil as controle electrode, and I-/I3- as electrode couple. The influence of dipping time of working electrode in dyes extract on the cell efficiency was investigated. The highest efficiency of roselle and mangosteen dye-sensitized solar cells was obtained at 60-minutes dipping, respectively as 0.017% and 0.032%. Characterization of both dyes extract by UV-Vis Spectrophotometry method showed that dyes adsorb in visible region. Keywords: Solar cell, sensitized, dyes, antosianin, TiO2

ABSTRACT Cacao beans contain many kinds of mineral, magnesium (Mg), calcium (Ca), Zinc (Zn), Phosphor (P) and etc. This study investigated magnesium (Mg) and calcium (Ca) in fermentation and non fermentation cacao beans by atomic absorption spectrophotometry. Mg and Ca, content in non fermentation cacao beans of green and red variety are 453 µg/g, 466 µg/g, and 491 µg/g, 445 µg/g. Mg and Ca, contents in fermentation cacao beans of green and red variety are, 596 µg/g, 528 µg/g, and 554 µg/g, 505 µg/g. Fermentation make magnesium (Mg) and calcium (Ca) content increase significantly. Keywords : Theobroma cacao Linn, fermentation, spectrophotometry.

ABSTRACT The selective transport of Ni(II) to Cd(II) through simultaneously liquid membrane technique has been investigated. The cell membrane was made by mixturing Ni(II) and Cd(II) ions at concentration as 3.41x10-4 M and 1.78x10-4 M respectively as source phase, oxine in chloroform as membrane phase and Na2EDTA solution as receiving phase. Concentration of recidual Ni(II) and Cd(II) ions in source phase transported to receiving phase was measured by Atomic Absortion Spectrofotometry (AAS). The results showed the at optimum condition of Ni(II) and Cd(II) transport occurred at source phase of pH 7, oxine concentration 0.001 M in chloroform and 0.04 M Na2EDTA solution pH 7. In this condition, Ni(II) and Cd(II) transport selectivity was found 80.89%. From the experiment, it was found that the transport rate constant from source phase to membrane phase (k1) for Ni(II) (0.7544 per hour) smaller than Cd(II) (1.3800 per hour ), on the other hand the transport rate constant from membrane phase to receiving phase (k2) Ni(II) (2.7580 per hour) greater than Cd(II) (1.3790 per hour). The phase-to-phase transport of Ni(II) and Cd(II) was consecutive first order reaction. Keywords : bulk liquid membrane, oxine, technique