Introduction: Lead (Pb) is of great concern in environment because of its toxicity to animals and humans.Lead is a cumulative toxin and known carcinogen. Although, plants do not require Pb for growth, the bioaccumulation index of Pb in plants exceeds that of most other trace elements. It is therefore important to control Pb concentration in plants, especially in the edible parts of crops to ensure food safety. …

In the last decades, extensive research works have been devoted to bitumen and asphalt modification by using polymeric thermoplastic-elastomers. In this research a physical thermoplastic elastomer was prepared by mixing polystyrene (PS) and polybutadiene (PB) for bitumen modification purposes. These blends were introduced into bitumen for making polymer-bitumen mixtures. Then, stabilization mechanism and mechanical properties of the mixture were studied by optical microscopy and conventional tests such as: Frass test, softening point, penetration, performance grade and penetration index. The PS/PB (75/25) blend forms larger PS droplets and shows minimum stability among the blends. The co-continuous composition of PS/PB blend (27/73) is stable and PS droplets are very well dispersed and its particle sizes are the lowest. In the next step, PS/PB/SBR compatibilized blend was mixed with bitumen and than further studies were carried out. The results show that mechanical properties and elastic recovery of these blends are highly improved as compared with the former non-compatibilized blend admixtures.

The temperature dependence of ac susceptibility of (Bi-Pb)2223 polycrystalline samples was measured as a function of frequency and ac field amplitude. Analysis of the temperature dependence of the AC susceptibility near the transition temperature (Tc) has been done employing Beans critical state model. The observed variation of intergranular critical current densities (Jc) with temperature indicates that the weak links are superconductor- normal metal-superconductor (SNS) type for this sample. The frequency effect on AC susceptibility was also measured. As the frequency increases, (Tp) shifts to higher temperatures. This effect can be interpreted in terms of flux creep. The temperature T, and field, Hac dependence of activation energy obtained from the Arrhenius plot for the frequency ( f) and (Tp) , can be described as: U(Hac,T) =U0(1- T/Tc)H-0.18ac

B ackground: Most of studies assessed the effect of Pb-exposure on serum total magnesium (tMg). The hypomagnesium condition depended on protein concentration in the sample and influence of lifestyle factors. This study assessed the effect of Pb-exposure on serum tMg, corrected Mg (cMg), ionized Mg (iMg), percentage of iMg from tMg, and percentage of iMg from cMg with contemplation of lifestyle factors. Study design: Case control study. Methods: The serum magnesium fractions were assessed in 176 male Pb-exposed workers in the year 2015 at Tamil nadu in India and 80 control subjects with no occupational exposure of Pb. The serum tMg and albumin concentrations were estimated using diagnostic kit methods. Blood lead levels (BLLs) were estimated using atomic absorbtion spectrophotometer method. The fraction of cMg and iMg were calculated from serum tMg and albumin concentration among individual subjects. Results: The BLLs was significantly (P<0. 001) increased in the study group as compared to control. Serum tMg, cMg, iMg, % of iMg from tMg and % of iMg from cMg concentrations were not significantly decreased in the study group as compared to control. Pb-exposure was significantly associated with abnormal frequency distribution of serum iMg (P=0. 048) and % of iMg from tMg (P=0. 016). Smoking habit was significantly associated with cMg (P=0. 039) and % of iMg from cMg concentration (P=0. 018). The alcohol consumption was significantly (P=0. 049) associated with cMg. Conclusion: The Pb-exposure and lifestyle factor such as smoking and alcohol consumption were associated with alteration of serum magnesium fractions.

Most of the studies assessed the effect of Pb-exposure on serum total calcium and phosphorus. This study assessed the effect of Pb-exposure on serum total calcium (TCa2+) and phosphorus (P) components such as corrected calcium (CCa2+), ionized calcium (ICa2+), percentage of ICa2+from TCa2+, percentage of ICa2+from CCa2+, ratios of TCa2+: P, CCa2+: P, ICa2+: P and product of Ca2+ and P in workers of different category of Pb-exposure. This study enrolled 176 male Pb-exposed workers and categorized into two groups based on blood lead levels (BLLs) recommended by BEI-ACGIH. The low Pb-exposure group is 86 workers with their BLLs is ≤ 30 μ g/dL and high Pb-exposure is 90 workers with their BLLs is > 30 μ g/dL). 80 healthy workers with no occupational exposure to Pb were included them as control for the comparison. The serum calcium, phosphorus and albumin concentrations were done by using diagnostic kit methods. BLLs were estimated by using the flame atomic absorption spectrometric method. The serum TCa2+, CCa2+ and ICa2+ were significantly decreased in low and high Pb-exposure groups as compared to control. The ratios of TCa2+: P, CCa2+: P, ICa2+: P was significantly decreased in the high Pb-exposure as compared to low Pb– exposure and controls. Product of TCa2+X P was significantly increased in the high Pb-exposure group as compared to low Pb-exposure. A negative association was noted between BLLs and serum TCa2+, ICa2+and CCa2+ in a high Pb-exposure group. The components of serum calcium and phosphorus were significantly altered in Pb-exposed workers.

Phytoremediation potential of Populus alba clone 44.9 to Pb-contaminated soil (concentrations of 0, 100, 500, 1000 mg Pb kg-1 soil) was investigated in greenhouse as completely randomized design. The results indicated that at the end of growing season, in the soil polluted with 1000 mg Pb kg-1, survival, stem length and stem collar diameter, and in the soil polluted with 500 and 1000 mg Pb kg-1, root/shoot ratio, biomass of organs (root, stem and leaf) and total biomass were significantly decreased in comparison with control. With increasing the Pb concentration of soil, Pb concentration of plant organs also increased whereas the highest Pb concentration of root, stem and leaf (212.38, 95.03 and 42.1, respectively) was observed in 1000 mg Pb kg-1. In all Pb concentrations the greatest and the lowest values allocated to root and leaf, respectively. Translocation factor increased in Pb-polluted soils (compared with control) and the greatest value (0.74 and 0.72) was observed in 100 and 500 mg Pb kg-1. Tolerance indices of shoot (min. 80%) and root (min. 45%) revealed that this clone has a relatively good tolerance even to maximum concentration of Pb heavy metal (1000 mg kg-1). Regarding to satisfactory survival, desirable growth, relatively good tolerance index and suitable Pb accumulation in seedling organs, it is concluded that this clone has a high phytoremediation potential to Pb-contaminated soil (till 1000 mg Pb kg-1). So, in further investigations for phytoremediation of Pb-contaminated soils (especially in field trials and with higher Pb concentration) this clone can be considered by researchers.

The studied Roudbar and Abhar plutons are located in the western Alborz zone and Taroum subzone. These intrusive bodies show metaluminous and shoshonitic nature and they cut the Eocene volcanic and sedimentary rocks. In the studied plutons, monzonite and quartz monzonite terms are dominant. According to geochemistry, these plutons were crystallized from non-primary magma, and have been experienced fractional crystallization. In the primary mantle normalized spider diagrams and chondrite normalized REE diagrams, studied samples show clear enrichment in the LREE and LILE and depletion in the HFSE. The primary magma originated from 1-5% partial melting of phlogopite bearing lithospheric mantle with spinel lherzolite composition that metasomatized by subduction agents. According to U-Pb SHRIMP dating, these plutons were intruded during 37.8 to 38.9 Ma in the late Eocene and in a post-collision tectonic setting.

During previous research studies, Pb- 2Sn-0.08Ca alloy was found to be the most suitable composition among Lead-Tin-Calcium compositions for fabricating anode electrodes for use in copper electro winning cells from the viewpoints of mechanical properties and corrosion resistance. In this paper the electro-catalytically behavior of the selected lead alloy is studied within a set range of applied current densities together with kinetics and reversibility capabilities of oxidation-reduction processes and the effect of CO3+ ions on reduction of over voltage of H2O anodic reaction during copper electro winning process using cyclic voltammeter technique (1 to 7 cycles), in applied potential range of -1300 to 2600 mV (vs. SCE) and at various scan rates. Then, the chemical phases of oxide layers formed over the Lead Anode surface within the applied potential range when inside 180 g/l H2S04 solution, was determined via XRD analysis. The obtained results indicate that the electrolyte resistively increases simultaneously, as the porous complex of Oxy- Sulphate Lead film is formed. Also at potentials more than 1.4V (vs. SCE), PbO2 film forms which has a good electro-catalytic property and high electrical conductivity. It is also true to say that this film (PbO2) is responsible for protecting the base metal from corrosion during copper electro winning process. In addition it has been shown that the kinetic of oxidation process, which yields to the formation of protective oxide layer is faster than the reduction process responsible for degradation of the protective film. Also the presence of Co3+ ions at 100ppm concentration can reduce the over voltage of H2O anodic reaction to as much as 200 mV.