The type of lightweight aggregate and its volume fraction in a mix determine the density of lightweight concrete. Minimizing the density obviously requires a higher volume fraction, but this usually causes aggregates segregation in a conventional mixing process. This paper proposes a two-stage casting process to produce a lightweight concrete. This process involves placing lightweight aggregate...

Quantitative studies of complex formation from the determination of stability constants of the binary complexes of metal (II)/(III)alizarin and also the mixed complexes of metal (II)/(III)alizarin-NTA have been described using paper electrophoretic technique. The stability constant of metal-(II)/(III)-alizarin are found to be 105.14, 104.84, 104.44 and 104.14 and mixed complexes of metal (II)/(...

shape-selective methylation of naphthalene (naph) over sapo-11 zeolite was carried out in a fixed-bed flow reactor under atmospheric pressure. some zeolites, such as h-beta (hβ), husy and zsm-5 were also evaluated for comparison with sapo-11 zeolite.the results showed that sapo-11 exhibited higher stability, higher selectivity of  2,6-dimethylnaphthalene (2,6-dmn), and higher 2,6-/2,7-dmn ratio...

In this research, two series of ultra-low cement high alumina refractory castables containing 0 and 0.4 wt.% of nano-titania were prepared using different amounts of polycarbonic acid (DOLAPIX FF 26) as a dispersant. Several characteristics including microstructure, flowability, mechanical strength, bulk density and apparent porosity of the samples were analyzed. The results showed that the opt...

introduction: one of the clinical problems in orthodontics is the bonding of brackets tocomposite restorations. the aim of this study was to evaluate the shear bondstrength of brackets bonded to composite restorations using excite. methods:forty brackets were bonded to composite surfaces, which were embedded inacrylic resin. one of the following four protocols was employed for surfacepreparatio...

In this paper, we introduce the production of ductile iron crankshaft of the engine status quo and development. Ductile iron crankshaft discussed smelting process, alloying and manufacturing process mode. This paper focuses on the application of isothermal hardened spheroidal graphite cast iron in the crankshaft, especially its application in the power of the engine crankshaft. We also introduc...

The results of experimental investigations on the study of concrete with partial replacement of cement are presented in this paper. The concrete grade of M30 has been selected and designed as per Indian Standard method. The specimens based on control mix have been cast without fly ash and silica fume. Cement was replaced by 0%, 10%, 20%, 30%, 40%, 50% and 60% of fly ash by the weight. 20 % of s...

a flow injection method is reported for the determination of ascorbic acid based on amperometric detection, using a cobalt(ii) phthalocyanine (copc) modified graphite-epoxy electrode. the amperometric respons was evaluated with regard to ph, ionic strength of the electrolyte, flow rate of the carrier solution, injected sample volume and conditioning time of the electrode. the limit of detection...

Polydimethylsiloxane (PDMS) elastomers are extensively used for soft lithographic replication of microstructures in microfluidic and micro-engineering applications. Elastomeric microstructures are commonly required to fulfil an explicit mechanical role and accordingly their mechanical properties can critically affect device performance. The mechanical properties of elastomers are known to vary ...