Vapor heat transfer in post-CHF region including the effect of thermodynamic non-equilibrium

Vapor phase heat transfer in the post-CHF region is modelled using momentum-transfer analogy and allowing for thermodynamic non-equilibrium. The vapor heat transfer coefficient is determined by momentum-transfer analogy, using an appropriate two-phase friction factor. The degree of thermodynamic non-equilibrium, denoted by the ratio of actual quality to equilibrium quality, is correlated in terms of a dimensionless temperature difference which includes the superheated vapor temperature. This correlation is solved simultaneously with a heat balance equation to determine the actual quality and the vapor temperature. Post-CHF vapor heat flux, calculated by this method, is compared to experimental tube data from eight different sources at pressures up to 2830 psia and over a wide range of mass fluxes. Results indicate an average deviation of 14.9% between measured and predicted heat fluxes for 2854 data points.     

Development of a multipurpose tile body: Phase and microstructural development

In this study, an attempt was made in order to develop a multipurpose tile body using a single formulation. In order to achieve this, several body recipes were prepared using mainly local raw materials with clearly defined physical and chemical properties at different sieve residues and single fast fired under industrial conditions in the first part of the study. In the second part, the most suitable formulations with the corresponding sieve residues were determined and further fired at different peak temperatures under laboratory conditions in order to establish their vitrification ranges and optimum firing temperatures. The tested peak firing temperatures were varied at 20 °C intervals from 1120 to 1200 °C for multipurpose wall tile body and from 1140 to 1220 °C for multipurpose floor tile body. The physical and thermal properties of the fired bodies such as water absorption, linear firing shrinkage, bulk density and linear thermal expansion coefficient were measured. The vitrification behaviour of the multipurpose bodies was also evaluated using a double-beam optical non-contact dilatometer. Furthermore, the fired bodies were subjected to colour measurements. Particular consideration was given to the phase and microstructural evolution of the developed tile bodies. X-ray diffraction (XRD) was used to analyse the phases formed before and after firing. Scanning electron microscopy (SEM) in combination with energy dispersive X-ray spectroscopy (EDS) was further employed in order to observe the microstructural and microchemical characteristics of the fired bodies with respect to peak firing temperature. The preliminary experimental results showed that it was possible to obtain a multipurpose body with the properties in accordance with ISO-EN 10545.     

Policy implications of trends in Turkey's meat sector with respect to 2023 vision

Turkey has become one of the leading emerging economies in the world being second after China as the highes ecoonomically growing country with 8.9% economic growth rate in 2010. Forecasting impacts of this development in coming 10 years might have very important policy implications for the meat sector in the framework of 2013 vision of Turkey. In this study, annual time series data which contain several key variables of meat sector in last 26 years (1987–2012) are used to forecast the variables of the coming twelve years (2013–2024) to drive policy implications by considering the impacts of high economic growths, crises and major policy changes. Forecasted future values of the variables for 2023 in the sector are assessed and compared with recent national and international values to drive policy implications. The results show that the economic growth results in the increase in per capita income and thus increased demand for meat seemed to foster the meat sector. Therefore, these macroeconomic indicators need to be better in addition to improvements at micro level for establishing competitive meat sector and thus reaching aimed consumption level of meat.     

Application of fuzzy extended AHP methodology on shipping registry selection: The case of Turkish maritime industry

Selection of the suitable shipping registry alternative for the existing fleet or new building ships is one of the critical decision milestones of the shipping business. The main aim of this paper is to structure a practical decision support mechanism on ensuring multiple criteria analysis of shipping registry selection. Fuzzy AHP methodology, based on Chang’s extent analysis, is determined to be utilized in order to model the shipping registry selection. After structuring the fundamental hierarchy, the model is performed with a case application on Turkish maritime industry to be able to obtain illustrative results. The shipping registries of Turkiye, Panama, and Malta are determined to evaluate as the potential alternatives for Turkish ship owners. When the literature was examined for the applications of analytical methodologies on maritime business, it was seemed that they were so rare. Therefore, the originality of this study appears on modeling of the critical process under multidisciplinary philosophy in ship management.     

Oxidative Processes in Muscle Systems and Fresh Meat: Sources,Markers, and Remedies

Oxidation of meat occurs under postmortem conditions and is inevitable. This oxidation includes the biochemical changes in meat leading to changes in color pigments and lipids. As a consequence, color deteriorates, and undesirable flavors and rancidity develop in meat thereby impacting on consumer appeal and satisfaction. Across carcasses, there is variation in the rate at which muscle undergoes chemical reactions under postmortem conditions that reflect inherent variation at the biochemical level. It is expected that this underlying biochemical variation will be reflected in living muscle through oxidative processes. The oxidative process of muscle tissues will vary according to an animal's immunity status, temperament, and ability to cope with stress, with all these affected by nutrition, genetics, management practices, and environmental conditions (hot and cold seasons). Identification of biomarkers that indicate the oxidative status levels of animals or muscle tissues in vivo could provide insight as to how the muscle will respond to the anoxic conditions that produce undesirable results in meat. This review outlines the potential use of 1 group of biomarkers, the isoprostanes, in the context of complex biochemical reactions relating to oxidative processes that take place in the biological systems of live animals (in vivo) and subsequently in meat (in vitro).     

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...     

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.     

Adsorption characteristics of ionic and nonionic surfactants on hydrophobic pigment in aqueous medium

The current study is based on the investigation of the adsorption properties of ionic and nonionic surfactants on an organic hydrophobic pigment powder, namely, β‐copper phthalocyanine, in aqueous medium. The nonionic surfactants, selected systematically to represent varying degrees of ethoxylation, are nonylphenol ethoxylates, whereas the ionic surfactant is sodium oleate, a carboxylate‐type anionic reagent. The adsorption of surfactants was assessed qualitatively by surface analysis of powders, before and after the adsorption of the surfactants. The experimental results were explained by the structural and other properties of the surfactants and the surface properties of the pigment. The specific adsorption of surfactants on pigments was verified by zeta potential measurements, as they altered the zeta potential values to a great extent. Nonionic surfactants decreased the absolute value of the zeta potential of the powder; whereas anionic surfactant sodium oleate shifted the zeta potential to more negative values. On the one hand, Fourier Transform–infrared and X‐ray diffraction examinations of the pigments did not show any noticeable evidence for surfactant untreated or treated copper phthalocyanine. On the other hand, thermal analysis (both thermogravimetric and differential thermal analysis) showed clear evidence of the surfactants on both pigments, as substantial changes in thermogravimetric curves were assessed.