design and optimization of a single crystalline silicon (c-si) solar cell is performed to achieve the maximum light conversion efficiency. various parameters such as doping concentration and thicknesses, and geometrical dimension of surface pyramids are studied. the inverted surface pyramid is used to increase the efficiency of the solar cell, and engineered oxide layer is used as the passivati...

objective: corrosion resistance is among the most important properties of metal alloys used in the oral cavity. consumption of acidic foods reduces the salivary ph and intensifies the corrosion of brackets and orthodontic wires. this study aimed to compare electro galvanic corrosion of different orthodontic brackets and wires and determine the amount of ions released into acidic artificial sali...

Divalent metal ions play a crucial role in catalysis by many RNA and protein enzymes that carry out phosphoryl transfer reactions, and defining their interactions with substrates is critical for understanding the mechanism of biological phosphoryl transfer. Although a vast amount of structural work has identified metal ions bound at the active site of many phosphoryl transfer enzymes, the numbe...

Sinorhizobium meliloti is an alpha-proteobacterium able to induce nitrogen-fixing nodules on roots of specific legumes. In order to propagate in the soil and for successful symbiotic interaction the bacterium needs to sequester metals like iron and manganese from its environment. The metal uptake has to be in turn tightly regulated to avoid toxic effects. In this report we describe the characte...

Membrane separation is a very well known technology having a large number of applications. Separation of metal ions by selective membrane transport is of great importance from both fundamental and practical viewpoints. According to IUPAC, a membrane is defined as a heterogeneous phase which acts as a barrier to the flow of molecules and ionic species in liquid or vapour phase. Membranes can be ...

Carbonic anhydrase contains one firmly bound zinc ion per enzyme molecule (1). The metal ion, which can be dissociated in the presence of a chelating agent, is essential for catalytic activity, and it has been suggested that it is a part of the active site (2). Some other divalent metal ions also activate the metal-free enzyme. For example, Co2+ gives 45oj, of the activity of the native enzyme ...

mn(tpp)cl catalyzes cooxidation of olefin in the singlet oxygenation of sulfid. mn(tpp)cl is able to transfer an oxygen atom from a peroxidic intermediate generated in singlet oxygenation of sulfide to a metal ion affording metal 0x0 species which is responsible for epoxidation. this system leads to allcenes epoxidation such as styrene and cyclooctene. epoxidation of cyclohexene produces cycloh...

Immobilized metal-ion affinity (IMA) adsorption is a collective term that is used to include all kinds of adsorptions where the metal ion serves as the characteristic and most essential part of adsorption center. Of all the IMA techniques, immobilized metal-affinity chromato graphy (IMAC) has been gaining popularity as the choice of purification technique for proteins. IMAC represents a separat...