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...     

Continuous Flow–Assisted Polyol Synthesis of Citric Acid Functionalized Iron Oxide Nanoparticles

Journal of Superconductivity and Novel Magnetism - The synthesis of nanoparticles by the continuous flow process is of great interest since it allows extensive control over reaction conditions with...     

Effect of magnetic treatment on fatigue life of AISI 4140 steel

The effect of magnetic field with different intensities on fatigue life of AISI 4140 steel has been investigated. For this purpose, unnotched and notched specimens were prepared from AISI 4140 steel. It was obtained that when the magnetic field especially was applied to the specimens at the stage of fatigue crack initiation, the fatigue life improved by reason of delaying formation time of slip bands due to regular direction and distribution of magnetic domains. And, it was observed that magnetic field was applied from the beginning of fatigue test up to occur the fatigue fracture, it was detrimental on the fatigue life because of over heating of the specimens.     

Experimental investigations of air and liquid injection by venturi tubes

The venturi system creates a pressure differential that forms a vacuum. As water flows through the tapered venturi orifice, a rapid change in velocity occurs. This velocity change creates a reduced pressure (vacuum), which draws air and liquid to be injected into the system. The air and liquid injection rates vary with the pressure differential across the venturi. Typical applications of venturi tubes are for injecting fertilizers, chemicals, ozone gas, air or oxygen into pressurized water systems. In this paper, experimental studies were conducted to investigate the effects of inlet and throat diameters of the venturi tube, pipe length downstream of the venturi tube, diameter of the suction pipe at the throat portion of the venturi tube, angle of the pipe downstream of the venturi tube, flow velocity at the inlet portion of the venturi tube and density and viscosity of the liquid injected into the venturi tube on air and liquid injection rate. It was observed from the results that venturi tubes had high air and liquid injection efficiencies.     

Stochastic dynamic response of masonry minarets subjected to random blast and earthquake‐induced ground motions

This paper presents the stochastic seismic response analysis of masonry minarets subjected to random underground blast and earthquake‐induced ground motions by using a three‐dimensional finite element model. The random blast and earthquake‐induced ground motions are represented by the power spectral density function and applied to each support point of the three‐dimensional finite element model of the masonry minaret system. This research conducted a parametric study to estimate the effects of the blast‐induced ground motion on the stochastic response of the minaret. Therefore, the analyses were carried out for the different values of the charge weight and the distance from the charge centre. In addition, in order to investigate the effect of earthquake‐induced ground motion on the stochastic response of the masonry minaret, three different soil conditions—soft, medium and firm soils—are considered in the analyses. Finally, it is noted that underground blast and earthquake effects cause the stochastic behaviour of minaret to change considerably. Copyright © 2009 John Wiley & Sons, Ltd.     

Dynamic oscillatory shear properties of O/W model system meat emulsions: Linear viscoelastic analysis for effect of temperature and oil concentration on protein network formation

Effects of oil concentration (57.50%, 58.75%, 60.00% and 61.25%) and temperature (5, 10 and 15 °C) on O/W model system meat emulsions were analyzed using oscillatory dynamic shear tests, allowing all emulsion systems to be characterized as linear viscoelastic solids exhibiting a pseudoplastic flow. The emulsion systems were characterized as weak gel-like macromolecular dispersions with G′ much greater than G″, exhibiting a plateau region. A modified Cox-Merz rule was applicable using shift factors. Frequency dependence of complex modulus (G^∗) was studied to measure strength of cross-linking protein network of the emulsion systems by calculating a practically constant order of the relaxation function (α = 0.10) and a concentration dependent stiffness parameter (A_α) using Friedrich and Heymann theory. It was concluded that the viscoelastic characteristics and strength of the emulsion systems increased with increasing oil level, but decreased with temperature. Different mathematical models were successfully constructed to predict the rheological parameters.     

The effects of nitrite on the survival of Clostridium sporogenes and the autoxidation properties of the Kavurma

Kavurma is a traditional cooked (fried) meat product manufactured to preserve meat. Some bacterial genera, e.g., clostridia are important in kavurma. The objective of this study was to determine the influence of nitrite and the traditional cooking process on the survival and proliferation of Clostridium botulinum and the autoxidation properties of the kavurma. For this purpose, Clostridium sporogenes having similar characteristics to C. botulinum was used, and the samples were inoculated with 10(6) CFU/g C. sporogenes cells before the traditional cooking. The final products were packaged and stored under refrigeration for 6 months, and then the oxidation parameters (TBA, peroxide and free fatty acid values) and C. sporogenes counts of samples were determined. It was observed that C. sporogenes could survive during the traditional cooking process and storage. However, counts decreased during storage; for example, nitrite containing samples initially had 3.21logCFU/g C. sporogenes and 2.73logCFU/g at the end of storage. While nitrite had a slight antimicrobial effect on clostridia, it significantly reduced the TBA, peroxide and FFA values of the samples. In conclusion, it is suggested that addition of 100ppm of nitrite might be useful in kavurma processing because of its role in limiting oxidation as well as its antimicrobial effect.     

Power parameters calculations based on wavelet packet transform

Power and power quality are of most importance in modern energy systems. The traditional method for power measurement and calculation uses Fourier transform. With Fourier transforms power calculations are performed in the time and frequency domains. However, it requires suitable windowing functions along with lengthy and complex (trigonometrically, exponentially, etc.) operations. In this study, a new approach which based on wavelet packet transform for power calculations of both fundamental and all harmonics of signals is proposed. The method is fast, efficient and overcomes limitations of the current techniques as mentioned above. The accuracy of the derived analytical equations is demonstrated via simulations implemented with the designed graphical user interface program and experimental works.     

3 Laser transmission joining in microtechnology

The laser is a joining tool which is particularly suitable for the application in microtechnology. The process variant laser transmission joining can be used both for welding thermoplastics and bonding of silicon and glass. The investigations presented in this paper cover detailed examinations of both processes. Concerning laser transmission welding of plastics it is examined how far the content of carbon black in the material influences the formation of the weld seam. It is shown that the optical depth of penetration, the weld seam width as well as the formation of the weld morphology differ with varying content of carbon black. Selective laser radiation bonding (SLB) is a novel method for joining silicon and glass based on the transmission heating of the interface of both joining partners and the thermo-chemical principles of silicon direct bonding. SLB shows advantages in reference to the thermal load of sensitive components like sensors and to the selectivity of the joining geometry. In this study the principle method of SLB and the latest advances like the integration of the thermal process control in the laser processing head will be presented. Also experimental test results of the process with constant laser power and thermal process control and the comparison of them will be shown.An erratum to this article can be found at     

Sensitivity of three pathogenic bacteria to Turkish cemen paste and its ingredients

Pastirma is a dry cured meat product which is pasted with cemen. This paste is prepared from ground fenugreek, garlic and red hot pepper (RHPP). In this study, the cemen mix/paste and all its ingredients were tested for their inhibitory effects on Escherichia coli, Staphylococcus aureus and Yersinia enterocolitica. All samples had a varying inhibitory effect against all the bacteria tested during 4 days of storage. Complete cemen paste showed the strongest inhibitory effect on the three pathogens compared to ingredients alone. Fenugreek and RHPP had a bacteriostatic effect while the cemen paste and garlic had a bactericidal effect. S. aureus was the most sensitive bacterium while Y. enterocolitica was the most resistant. The results of this study confirmed the protective effect of cemen paste and garlic in food preservation especially against E. coli, S. aureus and Y. enterocolitica proving safety for public health. Hence it might be concluded that cemen paste is the first hurdle to prevent bacterial contamination, and a low pH (～4.83) value would also add an additional barrier to secure safety of the product. Finally, it can be suggested that similar studies should be conducted on actual meat systems to confirm these findings.