Deterioration of concrete, which is mainly due to ignorance of environmental and service conditions, causes considerable costs for the construction industry. With this in mind, in this paper, results of investigation into the major causes of concrete deterioration in the Urumie Lake are presented. For the purposes of this investigation, samples were obtained by mixing two types of cement (OPC t...

Effects of surface chemical modification with sodium silicate on the gas-sensing properties of F-doped SnO2 gas sensor designed and fabricated employing micro-electro mechanical system (MEMS) technology were investigated. Gas sensing properties of the sensor were checked against combustible gases like H2, CO, CH4 and C3H8 at a heater voltage of 0.7 V. The H2 sensitivity of the surface modified ...

Abstract Estimation of water saturation, S w , in shaly sandstone is an intricate process. The surface conduction clay minerals adds up to the electrolyte pore spaces, thus generating high formation conductivity that overshadows hydrocarbon effect. In each resistivity-based saturation model, key parameter factor, F which typically derived from Archie’s Law. Referring a log–log plot between fact...

Light weight materials coupled to the need for cost-effective processing have combined to create a significant opportunity for aluminium powder metallurgy as its increasing interest. Aluminium alloy (AA 2219) metal matrix composite reinforced with multi walled carbon nanotube (MWCNT) produced by powder metallurgy (P/M) technique was analysed and CNTs dispersion were traced. The micro hardness a...

Deterioration of concrete, which is mainly due to ignorance of environmental and service conditions, causes considerable costs for the construction industry. With this in mind, in this paper, results of investigation into the major causes of concrete deterioration in the Urumie Lake are presented. For the purposes of this investigation, samples were obtained by mixing two types of cement (OPC t...

Germanium micro-strip sensors were selected as the sensor technology to take data in energy dispersive X-ray spectroscopy experiments at Extremely Brilliant Source (EBS) Grenoble (FR). It is important for this experimental technique use with a large uniform area and fine pitch. The former determines range of detectable single sensor. latter improves spectral resolution. A high stopping power al...

S U M M A R Y We propose a new, simple and efficient method to image electrical resistivity between a set of wells. Our procedure consists of two steps: first, we map the interfaces between various subsurface formations using seismoelectric conversions; second, we derive the formation resistivity using image-guided cross-well electric tomography. In the first step, we focus seismic energy at a ...

because of urgent needs of groundwater resources in the tochal region of north tehran, an integration of electric and electromagnetic methods was applied to investigate the location and the direction of water bearing fractures. first, the vlf electromagnetic profiling was performed on suitable places and two locations were detected for supplementary resistivity surveys. then, a number of vertic...