Recovery, Recrystallization, and Grain-Growth

This is a brief review of the important phenomena of recovery, recrystallization as well as grain-growth. The three mentioned phenomena are the mechanisms by which metals and alloys fix the structural damage introduced by the mechanical deformation and, as a consequence, in the physical and mechanical properties. These rehabilitation mechanisms are thermally activated. For this process, the materials have to be heated and any such heat-treatment is meant to reduce deformation-induced break is termed annealing. Other or different heat-treatments lead to recovery and recrystallization. It is rather strange that, though these phenomena are extremely important in metallurgical science and engineering, not so much work has been done as that in corrosion and shape memory technologies. An attempt has been made here to summarize all important aspects of these phenomena for the benefits of students of metallurgy, chemistry and solid state more

Iqra Zubair Awan

Procaine detection using hybrids of cobalt-metalloporphyrin with gold and silver nanoparticles

Two organic-inorganic nanomaterials derived from Co(II)-tetra(3-hydroxyphenyl)porphyrin (Co-3OHPP) and noble metal nanoparticles, namely: Co-porphyrin-nanoAu (Co-3OHPP/nAu) and Co-porphyrin-nanoAg (Co-3OHPP/nAg) were obtained and tested for their capacity to detect procaine. Both hybrids present changes in UV-vis spectroscopy after interaction with procaine, in the same range of procaine concentration. The silver colloid is more easily obtainable and more economically affordable and its hybrid has a wider range of procaine detection from 5.39 x 10-5 mol l-1 to 28.04 x 10-5 mol l-1 concentration, thus being useful for the monitoring of the anesthesic remanence in patients’ plasma. Besides, the plasmonic band of the hybrid is more clearly defined. AFM studies were performed to compare the morphology of the two hybrid materials, Co-3OHPP/nAu and Co-3OHPP/nAg after being exposed to procaine. Both materials display triangular geometries that in case of Co-3OHPP/nAg are not very well defined taking also the form of kvatarons and these two coexisting forms generate pyramidal more

Anca Lascu, Anca Palade, Mihaela Birdeanu and Eugenia Fagadar-Cosma

Characterization of Some Chemical and Physical Properties of Lithium Borate Glasses Doped With CuO and/or TeO2

Glasses used in this study are prepared economically at a relatively low melting temperature (650-750oC). Presence of alkalis such as Na2O works as a flux and enhances the melting process. A Simple comparative study between the effect of doping Cu2+ and/or Te4+ ions in lithium borate glasses before and after gamma irradiation has been discussed. Density, molar volume, optical UV transmittance, optical band gap energies, DC electrical conductivity and chemical durability of the prepared glasses are measured. It is found that doping with Cu2+ ions makes a disruption in the glassy network by increasing the number of non-bridging oxygens (NBO) forming a more open network structure. While doping with the fourfold Te4+ ions enhances the crosslinking of the glassy network giving more rigid structure since the relatively high molecular weights of Te4+ ions allow them to bond strongly with the glassy network. The last two assumptions can elucidate results obtained from the last more

E. M. Abou Hussein

Characterization of the Corallina Elongata Alga and Study of its Biosorption Properties for Methylene Blue

Biosorbents can be an alternative to activated carbon. They are derived from agricultural by-products or aquatic biomass. They are low cost and they may have comparable performances to those of activated carbon. The present study focuses on the characterization of the Corallina Elongata (CE) alga and its adsorption performance for Methylene Blue (MB), this alga is found in abundance at the Mediterranean coast of the city of Jijel in eastern Algeria. The dried alga was characterized using various characterization techniques such as DTA, TG, FTIR, XRD, SEM and EDX, which showed that the material consists essentially of a calcite containing magnesium. Batch adsorption studies were carried out and the effect of experimental parameters Such as pH, initial dye concentration, temperature, adsorbent dose and contact time, on the adsorption of MB was studied. The kinetic experimental data were found to conform to the pseudo-second-order model with good correlation and equilibrium data were best fitted to The Langmuir model, with a maximum adsorption capacity of 34.4 mg/g. The adsorption isotherms at various temperatures allowed the determination of certain thermodynamic parameters (ΔG, ΔH and ΔS). Finally, the adsorption results showed a good affinity between CE and MB with a high adsorption more

Farida Bouremmad, Abdennour Bouchair, Sorour Semsari Parapari, Shalima Shawuti and Mehmet Ali Gulgun

Effect of L-Arginine on the Carbon Microsphere Forming under Hydrothermal Carbonization

Carbon microspheres (CMs) with a diameter of 5-10 μm have been synthesized by hydrothermal carbonization of starch and L-arginine. The surface property and structure of CMs were examined by FT-IR spectra, N2 adsorption-desorption isotherms and SEM images. These characterizations indicated that the L-arginine does not connect into the CMs but it promotes the starch hydrolysis and polymerization-condensation reaction of intermediate, which accelerates the formation of CMs and improves the yield in shorter time. The surface property of CMs determines adsorption capacity for acetic acid. By contrast, the porosity resulted from the carbonization at 500 °C dominates the adsorption capacity for acetic more

Jilei Liang, Mengmeng Wu, Hongmei Cai, Hao Wang, Hua Huang, and Xiaorong Lu

Optimization of Zinc Ions Removal by Modified Phoenix Dactylifera L. Seeds Using Response Surface Methodology

The current study investigates the role of Phoenix Dactylifera L. (date palm) seeds as an effective biosorbent for removing Zn+2, a toxic heavy metal pollutant usually found in the waste streams of industries like fertilizer, mining and galvanizing etc. Date palm seeds were washed, dried, crushed in 170-300 um and modified by acidic treatment (0.1 MHNO3). The effect of most important parameters i.e., pH (3.5-6.1), initial zinc ion concentration (5-100mg/l), biosorbent dosage (0.1-1g) and contact time (0.5-60sec) have been studied via design expert software (version 8.0.6) of response surface methodology. The Box-Bhenken Design (BBD) was used in Response Surface Methodology (RSM) for designing the experiments and a number of 29 experiments were run. The model suggested by the design expert software was quadratic as it had maximum R2- value (0.9235) which indicated that the predicted values of quadratic model were best fitted to the experimental values. The significance of the factors was indicated by Analysis of Variance (ANOVA). The results showed that the metal uptake increased by increasing initial zinc concentration and decreasing in biosorbent dosage and pH while the contact time had negligible effect on the response surface. The parameters were numerically optimized and the optimum input parameters obtained were pH = 3.52, initial zinc ion concentration = 59.11ppm, biosorbent dosage = 0.1g and contact time = 60min with a metal uptake of 26.84mg/g. Therefore, (Phoenix Dactylifera L.) seeds substantially removed zinc ions under optimum more

Ainy Hafeez, Syed Mohsin Ali Kazmi, Muhammad Sulaiman, Chaudhry Haider Ali and Nadeem Feroze

Plasma-Treated Ce/TiO2-Palygorskite Catalyst for the NH3-SCR of NOx

Ce/TiO2-Palygorskite ternary composites were fabricated as an efficient catalyst for medium and low temperature NH3-SCR reaction and the optimal mass proportion (Ti:Pal=1:3) of this catalyst was confirmed by the catalytic performance test, in order to improve the surface dispersion , which needed to be further disposed by the Non-thermal plasma , after that, it was activated by thermal treatment at 400⁰C for 4 h. Based on the results obtained by XRD, FE-SEM, TEM, NH3-TPD, UV-vis (DRS), XPS, the treatment of plasma was much essential for the transformation from Ce4+ to Ce3+ on the surface of Ce/TiO2-palygorskite, to increase surface chemisorbed oxygen, and the improved dispersion, which were highly favorable for denitration. At about 350⁰C, the best NO conversion was respectively 90.59 % and 96.78 % for the untreated and treated catalysts, the latter possessed higher N2 selectivity. Besides, according to the research results on alkali metals poisoning resistance of these catalysts, it was discovered, the treated-catalyst poisoned by sodium salt had the best resistance performance, which might be related with the modification of the Non-thermal plasma, leading to more dispersed surface acid sites, to get more active sites, meanwhile, the toxicity of K was stronger than more

Kaige Chen, Ruoyu Chen, Zhe Tang, Hui Cang, Qi Xu

Synthesis and characterization of Low Molecular Weight Organogelators derived from amide derivatives of N-acetylglycine.

Six new N-acetylglycine amides and bisamides were prepared by reacting N-acetylglycine with different isocyanates including, hexamethylene diisocyanate, bis(4-isocyanatophenyl)methane, toluene 2,4-diisocyanate, 1,3-bis(2-isocyanatopropan-2-yl)benzene, phenyl isocyanate and 2-naphthyl isocyanate to furnish amides 1-6. The gelation ability of compounds (1-6) was investigated using fourteen different solvents including polar, non-polar organic solvents. Only compound 1 solidified toluene. Characterization of compounds (1-6) was done using spectroscopic methods, HRESI-MS, FTIR, 1H- and 13C-NMR. The morphology of toluene organogel (as xerogel) was determined through scanning electron microscopy (SEM).read more

Firdous Imran Ali, Rabel Shaikh, Ahmed Bari, Umair Ahmad Khan, Shoaib Muhammad and Imran Ali Hashmi

Novel Approach for the Determination of Nitrogen Fixation in Cyanobacteria

Non-heterocystous nitrogen fixing strains of cyanobacteria were screened by their ability to grow in nitrogen deficient media. The selected nitrogen fixing cyanobacterial cells were then cultured in BG11 media supplemented with [15N]-labeled sodium nitrate. Under these growth conditions any organic [14N] found in the cyanobacterial cells would simply come from nitrogen fixation because [15N] was the only available source of nitrogen in the medium. Amino acids extracted after different time periods (after 15, 30, 40, 50 and 60 days of inoculation) were used for the determination of the 14N/15N ratio using GC-MS. Results from the present study support the conclusion that at stationary phase of growth cyanobacterial nitrogen fixation was no longer supplying a significant amount of nitrogen. This approach not only provided a detailed method for the evaluation of the nitrogen fixing potential of the cyanobacteria in culture, but also suggests novel approaches for the assessment of the ability of the strains to provide nitrogen enrichment to plants under co-cultivation more

Sumaira Mazhar, Jerry D. Cohen and Shahida Hasnain

Synthesis, Characterization and Anticancer Activity of Isonicotinylhydrazide Metal Complexes

This study focuses characterization of iron (II), iron (III), cobalt (II), copper (II) and nickel (II) complexes of Isoniazid (INH) and studying their spectroscopic as well as physiochemical properties. FTIR studies showed that INH binds the metal from oxygen of carbonyl group and nitrogen of amino group. The proton NMR spectra of the metal complexes confirmed the conversion of ligand molecules into their respective metal complexes. However, pattern of splitting and shapes of peaks was observed but the protons resonated in the expected region. XRD patterns may be concluded that the complexes are mostly comprised of nano-sized particles behaving like amorphous materials. Scanning electron microscopy (SEM) revealed marked changes in the morphology of complexes, and their degradation at higher temperature strengthens the hypothesis of the successful formation of complexes. The MTT cytotoxicity assay was used for the screening these complexes against four human cell lines but the results did not prove more

Mansoor Ahmed. Zi-Ning Lei, Mohsin Ali, Syed Imran Ali, Konatsu Kojima, Pranav Gupta, Majid Mumtaz, Dong-Hua Yang, Syed Moazzam Haider and Zhe-Sheng Chen