Synthesis,electrochemical and spectroelectrochemical properties of highly soluble tetra substituted phthalocyanines with [4-(thiophen-3-yl)-phenoxy]

Zinc, oxo-titanium, cobalt, and manganese phthalocyanine derivatives substituted with nonperipheral 3-(tetra[4-(thiophen-3-yl)-phenoxy] moieties have been synthesized and characterized by elemental analysis, IR, ¹H NMR spectroscopy, electronic spectroscopy, and mass spectra. The compounds have good solubility in various polar and nonpolar organic solvents and not aggregated (in the same solvents) within a wide concentration range. Electrochemical and spectroelectrochemical measurements exhibit that incorporation redox active metal centers, Co^II, Ti^IVO and Mn^IIIOAc into the phthalocyanine core extend the redox richness of the Pc ring with the reversible metal-based reduction and oxidation couples of the metal centers in addition to the common Pc ring-based electron transfer processes.     

Investigation of spherisation in microstructures of aluminium casting alloys for thixoforging process

Thixoforging combined with low superheat casting (LSC) is a promising shaping process for aluminium casting alloys. LSC process is based on rapid solidification of an alloy which cast with low pouring temperature. With this method, a feedstock material is produced with non-dendritic microstructure that ready for spherisation in reheating sequence of further semi-solid process. Al-Si alloys are still castable even at low temperatures due to their excellent fluidities. This study subjects to present spherisation of A356 and A380 alloy billets cast with LSC process that provides appropriate beginning material with relatively high sphericity. Obtained billet parts were reheated for different times at a semi-solid state temperature. Some of these billets were directly quenched for observing the effects of reheating and the others were thixoforged. With sufficient reheating time, deformation of thixoforging process did not significantly affect on the spherical microstructure. Unnecessarily long reheating period caused excessive grain growth. A356 alloy had higher spherisation tendency than A380 alloy under similar process conditions.     

Evaluation of vibration characteristics of a hydroxyl (HHO) gas generator installed diesel engine fuelled with different diesel–biodiesel blends

There are two main reasons of alternative fuel search of scientists: environmental problems resulted from combustion of fossil fuels and limited reserves of crude oil. Biodiesel and Hydrogen (H₂) are two of the most promising alternative fuels with their environmental friendly combustion profiles. The aim of this study was to evaluate vibration level of a hydroxyl (HHO) gas generator installed and diesel engine using different kinds of biodiesel fuels. In this study, at different flow rates, the effect of HHO gas addition on engine vibration performance was investigated with a Mitsubishi Canter 4D34-2A diesel engine. HHO gas introduced to the test engine via its intake manifold with 2, 4 and 6 L per minute (LPM) flow rates when the engine was fuelled with sunflower, canola, and corn biodiesels. The vibration data was collected between 1200 and 2400 rpm engine speeds by 300 rpm intervals. Finally, artificial neural network (ANN) approach was conducted in order to predict the effect of fuel properties and HHO amount on engine vibration level.     

Availability of tuffs from northeast of Turkey as natural pozzolan on cement, some chemical and mechanical relationships

At Northeast of Turkey, it is possible to find plenty of volcanic origin rocks and rich natural pozzolan beds. In this study, the pozzolanic activities of six types of different tuff samples taken from Trabzon and Bayburt regions (Northeast of Turkey) were examined according to the related standard and it was determined that the compressive strengths were varying between 6.7–11.0 MPa. In addition, the chemical compositions of these samples, except one, were consistent with the related standard. On the other hand, the results obtained from these studies were that increase in the proportion of SiO₂ in the pozzolan increases the pozzolanic activity.     

Engine Performance and Exhaust Emission Tests of Sulfate Turpentine and No:2 Diesel Fuel Blend

Environmentally friendly, biobased fuel additives become more important when environmental concerns all around the world are considered. In this study, sulfate turpentine is investigated as a candidate diesel fuel additive. Engine performance tests were conducted on a 53 kW, 4000 rpm Peugeot XD 3P 157 type diesel engine for 3:97 turpentine and No:2 diesel fuel blend and similar results to No:2 diesel fuel were obtained. Significant reduction in exhaust emissions were observed as a result of using turpentine and No:2 diesel fuel blend.     

The effects of brine concentration and scalding on survival of some pathogens in urfa cheese: a traditional white-brined turkish cheese

The survival of Staphylococcus aureus (St. aureus), Bacillus cereus, Yersinia enterocolitica, Eschericia coli O157:H7, Shigella flexneri (Sh. flexneri) and Salmonella enteritidis (Sa. enteritidis) in urfa cheese (a traditional white‐brined Turkish cheese) which was stored in brine concentrations varying from 12.5 to 17.5% (wt/v) was tested. Two sets of cheeses were made, namely scalded and unscalded cheeses (scalding was done by heating at 95 °C for 3 min). The variations in the counts of pathogenic colonies were monitored throughout a 90‐day storage period at <10 °C. Results indicated that scalding caused statistically significant reductions in the colony counts of Y. enterocolitica, E. coli O157:H7, Sh. flexneri and Sa. enteritidis during the early periods of storage. In contrast, St. aureus and B. cereus were not generally affected by scalding and brine concentrations, although B. cereus in 17.5% (wt/v) brine was affected. In the unscalded cheeses, 12.5 and 15.0% (wt/v) brine concentrations seemed to be insufficient to eradicate the pathogenic organisms examined.     

Immitance data modelling via linear interpolation techniques: A classical circuit theory approach

With the advancement of the manufacturing technologies to produce new generation analog/digital communication systems, immitance data modelling has gained renewed importance in the literature. Specifically, models are utilized for behaviour characterization, simulation of physical devices or to design sub‐systems with active and passive solid‐state devices. Therefore, in this paper, new computer aided tools are presented to model one port immitance data by means of linear interpolation techniques. The basic philosophy of the new modelling tools is based on the numerical decomposition of the immitance data into its minimum and Foster parts. Computer algorithms are presented to model the minimum and the Foster parts of the given immitance data. Implementations of these algorithms are exhibited by means of examples. Depending on the application, modelling tools based on linear interpolation techniques may present ‘computational and practical’ advantages over the existing interpolation techniques, non‐linear curve fittings or regression methods. It is expected that the new modelling tools will be utilized to provide initial circuit topologies to the commercially available analysis/simulation and design packages. Copyright © 2004 John Wiley & Sons, Ltd.