Fe3O4 nanoparticle decorated novel magnetic metal oxide microcomposites for the catalytic degradation of 4-nitrophenol for wastewater cleaning applications

Journal of Materials Science: Materials in Electronics - Co3O4, NiO and ZnO microparticles were decorated with Fe3O4 nanoparticles where novel Co3O4@Fe3O4, NiO@Fe3O4 and ZnO@Fe3O4 microcomposites...     

Titanium to steel joining by spark plasma sintering (SPS) technology

The bonding of Ti–6Al–4V to low alloy steel (AISI4330) using SPS technique in the 850–950 °C temperature range was examined. The formation of a thin (～1 μm) titanium carbide interfacial layer was observed with a thickness only slightly dependent on the joining temperature. This layer separates the joined metals and prevents the formation of Fe–Ti intermetallics in the bonding zone. The maximal tensile strength of the joints (of about 250 MPa) was achieved for bonding at 950 °C for 3.6 ks. The formation of the titanium carbide layer and its evolution are discussed based on the isothermal section of the ternary Fe–Ti–C phase diagram.     

Poly(vinyl phosphonic acid) (PVPA)–BaFe12O19 Nanocomposite

We present a method for the fabrication of PVPA/BaFe₁₂O₁₉ nanocomposite by in-situ polymerization of vinyl phosphonic acid, VPA in the presence of synthesized BaFe₁₂O₁₉ NPs. Nanoparticles and the nanocomposite were analyzed by XRD, FTIR, TGA, SEM, TEM, VSM, and conductivity techniques for structural and physicochemical characteristics. Nanoparticles, identified as BaFe₁₂O₁₉ from XRD analysis, were successfully coated with PVPA and the linkage was assessed to be via P?CO bonds. Electron microscopy analysis revealed aggregation of BaFe₁₂O₁₉ particles and dominantly platelet morphology upon composite formation. TGA analysis revealed the composition of the nanocomposite as 65% BaFe₁₂O₁₉ and 35% polymer. Magnetic evaluation revealed that adsorption of PVPA anions during the preparation of the nanocomposite strongly influenced the magnetic properties resulting in much lower saturation magnetization values. DC conductivity measurements were used to calculate activation energy of PVPA/BaFe₁₂O₁₉ nanocomposite and it was obtained as 0.37?eV.     

Effect of air distribution profile on selectivity at zinc cleaner circuit

Airflow rate to a cell is one of the main operating variables in flotation. In many plants, if measurements are available at all, they are typically made on a line common to several cells with valves to distribute as determined by the operator. In this study, air distribution throughout zinc cleaner circuit of CBI was adjusted to three different profiles. These are “as found” which was the original profile adjusted by operators, “decreasing” and “increasing” profiles which were adjusted for test. It was seen that air distribution profile significantly affected flotation selectivity. Selectivity between both sphalerite–pyrite and sphalerite–chalcopyrite increased with “increasing” profile. The effect of air distribution profile on flotation selectivity was also studied at mini pilot plant (MPP). Zinc rougher concentrate was taken as feed of MPP. Air distribution profile was adjusted and controlled by airflow meters of each cell. Three different air profiles; “balanced”, “decreasing” and “increasing”, were tested. The results of MPP tests also confirmed that “increasing” air distribution profile improved selectivity at zinc cleaner circuit.     

Low Temperature Plasma for decontamination of E. coli in milk

Raw milk is a natural, highly nutritious product and a quick and easy supplement for human dietary requirements. Elimination of bacteria in milk has been a problem for decades and new methods with regards to non-thermal applications which do not harm the chemical composition of milk, are currently under investigation. The objective of the study was to determine the potential use of a novel, Low Temperature Plasma (LTP) system for its capability of killing Escherichia coli in milk with different fat contents. The time dependent effect of atmospheric corona discharge generated with 9kV of AC power supply on E. coli ATCC 25922 dispersed in whole, semi skimmed and skimmed milk was examined. Plasma was applied at time intervals of 0, 3, 6, 9, 12, 15 and 20min. A significant 54% reduction in the population of E. coli cells after only 3min was observed regardless of the fat content of the milk. The initial pre-plasma bacterial count of 7.78 Log CFU/ml in whole milk was decreased to 3.63 Log CFU/ml after 20min of plasma application. LTP did not cause any significant change to the pH and color values of raw milk samples. No viable cells were detected after one week examination in whole milk samples and remained so over the 6week storage period. The findings of this study show that the novel LTP system tested was able to significantly reduce E. coli in milk by more than a 3 fold log reduction without significantly affecting pH or color properties.     

An investigation about comfort and protection performances of disposable and reusable surgical gowns by objective and subjective measurements

This study was conducted to investigate comfort and microbial protection performances of two reusable and two disposable surgical gowns by subjective wear trials conducted on eight healthy Dentistry faculty students under environmental conditions suitable for a surgical operation. Protection performances of the gowns were tested by a modified bacterial resistance test. Physiological and psychological data were obtained during wear trials. All objective and subjective results were evaluated in the light of standard physical, mechanical, permeability, and resistance (thermal and water vapor) characteristics of the fabrics. According to the results, thermal comfort performance of the woven gown produced from microfiber polyester was the best according to subjective wear trial and microbial resistance test results. Disposable nonwoven gowns had lower comfort performances despite their higher permeability and lower resistance values. Moreover, chest skin temperature, arm microclimate temperature, and arm relative humidity are the physiological parameters significantly correlated with subjective comfort evaluation results.     

Characterization of interlaminar shear strength of laminated woven E‐glass/epoxy composites by four point bend shear test

An experimental and numerical investigation was performed to study the interlaminar shear response of laminated woven E‐glass/epoxy composites. The interlaminar shear strength results obtained from four point bend shear tests were compared with the results obtained from American Society for Testing and Materials (ASTM) test standards D2344 (short beam strength). The test results reveal that the four point bend interlaminar shear test results at a span to thickness ratio of 8 is higher than the short beam shear test results at a span to thickness ratio of 4. Numerical simulations were performed with ANSYS® software. The experimental results and the corresponding numerical results are in good agreement. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Comparative study of conducting polyaniline/copper and polyaniline/nickel composites in the presence of surfactants

Polyaniline/copper and polyaniline/nickel composites were synthesized in the presence and absence of surfactants using ammonium persulfate as an initiator. The structural and surface characteristics of the composites were studied and compared using different techniques. The interfacial interactions and thermal stability of the composites were characterized using X‐ray diffraction and thermogravimetric analysis. Surface properties were investigated using scanning electron microscopy and energy‐dispersed X‐ray spectroscopy. The results indicate significant changes in the morphological and physicochemical properties of the composites when incorporating surfactants. The surfactant‐induced surface characteristics also have an effect on conductivity. Copyright © 2010 Society of Chemical Industry