Geopolymer is an inorganic form of alumina-silica that synthesized through materials containing lots silica (Si) and alumina (Al) originating from nature or industrial by-products. The geopolymer binder a two-component system consisting solid components have sufficient amounts SiO2 Al2O3 to compounds such as fly ash, rice straw pozzolan, laterite soil, slag, etc. This study aims analyze the com...

The effect of specimen aging on the recovery of mercury from urine samples was investigated. It was found that in some aged specimens the addition of concentrated sulfuric acid to the urine without cooling resulted in a large loss of mercury. This phenomenon is presumed to be due to enhanced volatility of the mercury caused by bacterial action. This loss can be avoided by adding a suitable pres...

We compared results for the liquid-chromatographic determination of free norepinephrine and epinephrine in urine after purifying the catechols by the following methods: (a) acid-washed alumina, (b) weak cation-exchange resin (WCX), (c) a combination of weak cation-exchange resin followed by alumina (WCX-alumina), and (d) commercially available phenylboronic acid adsorbent. We evaluated analytic...

The expense of repair and maintenance of private and public sewage systems in Germany runs to about 100 billion US $. This primarily affects concrete pipes and brickwork sewers. Approximately 40 per cent of the damage can be attributed to corrosion by biogenous sulfuric acid attack as a result of long flow periods and insufficient ventilation of waste water. The report deals with investigations...

Electrolytic manganese dioxide (EMD) was prepared by using gas diffusion electrode (GDE) instead of traditional hydrogen evolution cathode. Sulfate acid’s effects on the cell voltage, the current efficiency, the electro-catalytic activity and the lifetime of GDE are studied. The results show that as the concentration of sulfuric acid increases, the current efficiency increases, while the cell v...

nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. the catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. the size of nanoparticles were observed with sem.all prepared compounds w...

the silica boron sulfuric acid nanoparticles (sbsans) as an efficient heterogeneous solid acid catalyst with both brønsted and lewis acidic sites catalyzed the preparation of bis-4-hydroxycoumarin derivatives using reaction of aldehydes and 4-hydroxycoumarin under mild and solvent-free condition at room temperature. this new and efficient methodology has advantages in comparison with currently ...