one of the most important dimention of the industrial structure is the concentration. in order to determine concentration in iranian industries from 2000 to 2005, the 5-firm concentration ratio is used in terms of sale value, production, value added and employment variables. the results indicate high correlation among concentration ratios in terms of sale, employment, value added and production...

The technical feasibility of using calcium oxide (CaO) as a sorbent for CO2 and Fe-Cr as a catalyst for the water-gas shift (WGS) reaction using syngas for the steam gasification of biomass was investigated. The effects of temperature, steam to biomass mass ratio, CaO to biomass molar ratio, and Fe-Cr WGS catalyst on gas composition were studied. Within a temperature range of 250 C to 550 C, ...

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the brain, and plays a key role in brain development. However, the in vivo levels of brain GABA in early life are unknown. Using edited MRS, in vivo GABA can be detected as GABA+ signal with contamination of macromolecule signals. GABA+ is evaluated as the peak ratio of GABA+/reference compound, for which creatine (Cr) o...

Background: Due to difficulty of obtaining a 24h urine (especially in children), a random urine calcium sample is recommended to detect of hypercalciuria. However, recent studies have shown that the urinary calcium/creatinine ratio varies with age and geographic areas. So, the aim of this study was determining the normal value of urinary calcium to creatinine ratio in healthy adolescent’s...

The long-term effects of different influent Cr(VI) concentrations (0–0.5 mg L−1) on the nitrification activities and microbial community structures of nitrifying activated sludge system were investigated in this study. Results showed that the performance of ammonia oxidation was significantly inhibited, and the effluent concentration of ammonia nitrogen (NH4-N) increased markedly when the influ...

Recent measurements of the positron/electron ratio in the cosmic ray (CR) flux exhibits an apparent anomaly1, whereby this ratio increases between 10 and 100 GeV. In contrast, this ratio should decrease according to the standard scenario, in which CR positrons are secondaries formed by hadronic interactions between the primary CR protons and the interstellar medium (ISM)2. The positron excess i...

Adsorption behavior of chromium, Cr(VI) from wastewater has been investigated using clarified sludge (a steel plant waste material), rice husk ash and sawdust as non-conventional adsorbents. The studies were carried out at room temperature (30C) following batch adsorption technique in a reciprocating shaker. Factors affecting the adsorption characteristics such as agitation time, initial metal ...

Concentration levels of hexavalent chromium in contaminated soil and in Zea mays plant parts were determined and Cr(VI) bioaccumulation and bioconcentration capacity of this plant were discussed. Zea mays seeds were sown in 40 mg Cr(VI)/kg dw polluted soil. After harvesting it was observed that hexavalent chromium concentrations in plant organs decreased in the following order: roots > stems > ...

abstract  background: despite the long-standing association of macrophage migration inhibitory  factor (mif) with delayed-type hypersensitivity response, the potential role  of mif in chronic allograft nephropathy is unknown. the association between upregulation of mif expression, macrophage and t cell infiltration and the severity of  chronic allograft nephropathy suggests that mif may be an i...