The effect of the die materials on the fracture strength of CAD/CAM monolithic ceramic crowns was studied in this research. Three different types of die materials (dentin, Ni-Cr alloy, epoxy resin) were prepared. The monolithic crowns were fabricated using a CAD/CAM System; CEREC 4. The CAD/CAM crowns were cemented to dies using a resin cement. The specimens were tested under compressive load a...

The asymmetric unit of the title compound, [Ni(C(12)H(8)N(2))(3)][Cr(2)O(7)]·4H(2)O, contains one cation, one anion and four water mol-ecules, three of which are disordered over two sites with equal occupancies. In the cation, the metal centre is coordinated by six N atoms from three 1,10-phenanthroline ligands in a distorted octa-hedral geometry. The [Cr(2)O(7)](2-) anion exhibits a staggered ...

Epidemiology has indicated a possible increase in lung cancer among stainless steel welders. Chromium (Cr) is a primary component of stainless steel welding fume. There is an initiative to develop alternative welding consumables [nickel (Ni)- and copper (Cu)-based alloys] that do not contain Cr. No study has been performed to evaluate the toxicity of fumes generated from Ni- and Cu-based consum...

Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. While federal regulations have reduced permissible worker exposure limits to Cr(VI), this is not always practical considering that welders may work in confined spaces an...

The temporal distribution of trace elements in a sediment core (SK117/GC-08) indicates minor changes oxygenation during the last 100 kilo years bottom waters deeper eastern Arabian Sea. high values Mn, Co, Cu, Mn/Al, Co/Al, Cu/Al, V/Cr, and V/(V + Ni) sediments interglacials interstitials collectively indicate oxic conditions warm periods. Cr, Ni, V, Mo, Cr/Al, Ni/Al, Ni/Co glacials stadials dy...

Concentrations of the elements Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, N, Ni, P, Pb, and Zn were measured in needles and bark of Taxus baccata from the urban environment of Wrocław, Poland, and from a control site relatively free from pollution. In Wrocław the concentrations of N, P, K, and Mg in needles were significantly higher than in bark, but concentrations of Cd, Co, Cr, Cu Fe, Ni, and Zn were...

During a period of 60 days assays were carried out with the moss Pohlia nutans transplanted from an uncontaminated control site to a dump consisting of a heavily polluted mine and smelter wastes located near wałbrzych in southwestern Poland. within the same period also samples of native P. nutans growing on the dump substrate were collected together with the same species from a control site. Co...

In vitro tensile bond strengths were determined for three adhesive cements and two resin-bonded bridge cements to two alloys, each prepared by two methods: sandblasted Ni-Cr-Be alloy (I), electro-etched Ni-Cr-Be alloy (II), sandblasted Type IV gold alloy (III), and tin-plated Type IV gold alloy (IV). Storage conditions of 24 hours at 37 degrees C and 30 days at 70 degrees C were evaluated. The ...

Several electroplating industry including agricultural sector industries, sewage treatment and mining operations all combine to generate hazardous waste water containing enormous amounts of toxic heavy metals. The accumulation of toxic heavy metals in human beings and animals cause many metabolic disorders. Heavy metal concentration was estimated in sewage, sludge and electroplating wastewater ...

Surface soil samples were collected from 52 sites around Guanting Reservoir in Beijing, China, and contents of 'total' metals (Cu, Zn, Pb, Cd, As, Ni and Cr) were determined. The results indicate that the degree of heavy metal pollution in the soils declines in the order of Cd>Cr>Zn>As>Cu>Ni>Pb. Based on the results of a combination of multivariate statistics and geostatiscal analyses, it was c...