Propagation of waves in magneto-thermo-viscoelastic solids subjected to a uniform magnetic field

The propagation of magneto-thermo-mechanical (MTM) plane waves in electrically and thermally conductive magneto-thermo-viscoelastic (MTVE) unbounded solids is investigated with account for the mutual effects of the magnetic, thermal and strain fields. Concerning the mutual and thermo-electric effects in isotropic solids the governing equations are first linearized. In the linearization, the material is assumed to be subjected to a uniform and primary magnetic field in any direction while the material undergoes infinitesimal deformations. It is shown that the governing equations at the intermediate state are fulfilled by the presumed MTM-fields. Furthermore, the dispersion relation which allows us to consider the entire frequency range, the effect of the magnetic field and some nondimensional material parameters is obtained. Therefore, several modes of MTM-waves arise depending upon the direction of the magnetic field such as the uncoupled magnetic and mechanical S-mwaves, the coupled S-wave, the modified mechanical $\text{P}$-and thermal waves, and the modified and coupled MTM-waves. It is seen that all modes of the wave are dispersive and dissipative due to the conductivity and the viscosity of the material. Then the phase velocities and the attenuation constants for the coupling modes are obtained, and some limiting values are discussed. From the expressions follow, in particular, the results for the elastic case, the propagation of mechanical waves in nonconductive materials.     

Plane waves in electrically conducting and magnetizable viscoelastic isotropic solids subjected to a uniform magnetic field

The propagation of plane electromagneto-mechanical (EM M) waves in homogeneous, initially unstressed and isotropic, electrically conductive magnetoviscoelastic solids in a uniform primary magnetic field is investigated. Depending upon the direction of the applied magnetic field, several modes of the waves arise such as coupled mechanical (M) and electromagnetic (EM) waves. The phase velocities and the attenuations of the waves are obtained both analytically and numerically. Some interesting behavior of the phase velocities and the attenuations are, in particular, detected for certain frequencies, intensity and direction of the primary magnetic field, viscoelastic parameters and conductivity. For example, there are anomalous dispersions of the coupled modes of EM- and M-waves depending upon the intensity of the primary magnetic field, viscoelastic parameters and the conductivity of the material.     

Tenuous boundaries: women, domesticity and nationhood in 1930s Turkey

In the 1930s modern architecture was highly popularised in Turkey mostly through the widespread promotion of the modern house. In the early stages of nation building, the modern house became one of the most potent symbols of the modern nation, which aspired to enter the European economic, cultural and political milieu as an equal partner. The image of the modern Turkish woman played a somewhat similar role, her increasing access to various aspects of the public sphere being highly publicised as the success of Turkish modernisation. Despite obvious links between women and architecture, ranging from their active promotion as suitable images for the new nation to the physical appearance of women in public spaces, issues of gender and sexuality remained conspicuously absent from the architectural historiography of modern Turkey. In this paper, I offer critical readings of contemporaneous representations that relate the modern house and modern Turkish woman to uncover the complicated and contradictory levels that constitute the seemingly coherent narrative of architectural and cultural modernisation. The analysis of the relationship between sexuality, space and architectural discourse effectively complicates the architectural historiography of modern Turkey and shows the active participation of architecture in the production of the social/cultural realm.     

Municipal solid waste management and practices in coastal cities of the Eastern Black Sea: a case study of Trabzon City, NE Turkey

Each day some 400–450 ton solid waste is dumped on land and in the sea and rivers in the coastal cities of the eastern Black Sea, creating serious environmental problems. The paper reports the engineering geological studies of a proposed landfill site for Trabzon, a major city in the region. Fieldwork included scan-line and seismic surveys as well as boreholes and in-situ testing. Water absorption tests indicated permeabilities in the order of 10⁻⁸ m/s.      

Development of spring-in angle during cure of a thermosetting composite

The development of spring-in angle during cure of AS4/8552 thermosetting composite is investigated by using a cure quench technique. C-shaped preforms are cured on the inner wall of an aluminium tube. The cure is interrupted at various points during the Manufacturer's Recommended Cure Cycle (MRCC) by quenching the tool tube into water. The diameters of the specimens cured in this way are measured and the spring-in angles for a 90° arc of the specimens are calculated. The test data show that the samples quenched at earlier stages of cure exhibit a larger spring-in and the spring-in angle reduces as the specimen is further cured.

A cure kinetics simulation is performed to understand the development of cure throughout the MRCC. It has been found that the vitrification of the specimen occurs approximately 45 min after the start of the 180 °C dwell period, and the specimens quenched before vitrification are observed to have larger spring-in.

An explanation of this observation is the fact that, before vitrification the specimen is in the rubbery state during the temperature range between the cure temperature and the instantaneous glass transition temperature, and in this state it has a larger thermal expansion coefficient compared to that in the glassy state, causing more contraction in the through-the-thickness direction, hence more spring-in.

The cure quench experiment provides an insight into the relative importance of the thermal contraction above and below the glass transition temperature and the cure shrinkage.     

Bacterial and fungal microbiota of mould-ripened cheese produced in Konya

Bacterial and fungal diversities of 24 mould-ripened cheeses originating from Konya-Türkiye were examined by metagenomic analysis. Firmicutes phylum, Enterococcus, Clostridium sensu stricto and Lactobacillus (Levilactobacillus) genera were the dominant bacteria. Ascomycota phylum and Penicillium and Pichia genera and Penicillium roqueforti and Pichia membranifaciens species were dominant fungi. Enterococcus faecium (n = 30) and Enterococcus faecalis (n = 6) were identified, and all strains were susceptible to penicillin, ampicillin, vancomycin, teicoplanin, chloramphenicol and linezolid. The highest resistance (n = 14) was against rifampin. Tetracycline resistance was determined in two strains. Biofilm-forming ability was found in nine E. faecium and 1 E. faecalis. E. faecium strains revealed 40–88.9%, and E. faecalis showed 59.2–100% homology by pulsed field gel electrophoresis.     

Evaluation of Nitrite in Ready-Made Soups

As time is very important for today’s people, ready-made soups in different forms (powder, liquid, canned) are consumed highly. Nitrite has been implicated with a variety of long-term adverse effects and has been of interest to public health providers and governmental regulators for the last 40 years. The present study was aimed to assess nitrite levels in commercially available soups in powder form by using a spectrophotometric method and to evaluate the possible toxicological outcomes. For this purpose, 66 ready-made soups were randomly collected and divided into seven groups: tomato-, chicken-, yoghurt-, mushroom-, lentil-, meat-, and vegetable-based. The minimum–maximum and median levels of nitrite content of the soup groups are 28–2,091 (median, 108), 53–400 (median, 136), 26–129 (median, 47), 58–197 (median, 109), 12–225 (median, 38), 12–555 (median, 40), 184–1229 (median, 389) mg kg⁻¹, respectively. Meat- and tomato-based soups have the highest nitrite contamination among the groups. On the other hand, acceptable daily intake (ADI) of nitrite given by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and Scientific Committee on Food (SCF) is 0–0.07 mg kg⁻¹ (body weight, b.w.) per day, while Environmental Protection Agency (EPA) has set a reference dose (R_fD) of 0.10 mg nitrite nitrogen per kilogram b.w. per day (equivalent to 0.33 mg nitrite ion per kilogram b.w. per day). This means that the highest intake of nitrite a 70-kg person must be no more than 4.9 mg in 1 day according to JECFA and SCF and 7 mg kg⁻¹ b.w. per day according to EPA. However, nitrite intake from one portion (13 g) meat-based soups, when calculated with median daily intake levels (5.05 mg), exceeds the limit of JECFA and SCF. With long-term daily consumption of high nitrite levels exceeding ADI, the risk of mild to moderate methemoglobinemia would be increased, especially for susceptible populations such as young children and elderly. Besides, the higher intake of nitrite from foodstuff and other sources may induce the formation of carcinogenic nitrosamines which are formed endogenously from nitrites and nitrates. The first results of the study were presented as a poster at the 121st AOAC Annual Meeting & Exposition, held at Anaheim, California USA, September 16–20, 2007.     

How a new realistic mobility model can affect the relative performance of a mobile networking scheme

The validity of the mobility model used to evaluate a cellular network determines the validity of the evaluation. In the literature, unrealistic assumptions on mobility are exercised for the sake of simplicity. In this paper, we present a novel mobility model which is realistic in the sense that it captures the moving‐in‐groups, conscious traveling and inertial behaviours of the subscribers while respecting the non‐pass‐through feature of structures like households and preserving the autonomy of the subscribers. The mobility and call patterns of the subscribers are determined according to the locus of the subscriber over a real map. Thus, our model allows the subscribers to leave home or arrive home, walk or drive in the streets, get on the highways at specific entry points together with numerous hot and blind spots in the terrain, like city centers and lakes. The call pattern of a subscriber is affected by the type of structure he is in. The model can work on real maps to simulate the mobility patterns in real life. We have evaluated the proposed model against the well‐known way point mobility model. We also analyzed the effect of the mobility model on systems with and without guard channels. Copyright © 2004 John Wiley & Sons, Ltd.     

Oil recovery from lime‐treated wastewater of olive mills

Olive mill wastewater is a by‐product of olive oil production and generates a major environmental problem in the Mediterranean area. The amount of oil and grease, which is one of the parameters used for the characterization of this wastewater, cannot be determined easily using a standard method. Therefore some modifications of the standard method were investigated in this study. To this end wastewater was first treated with lime, without using diatomaceous‐silica, then acidified, filtered through muslin cloth only, and finally extracted with an organic solvent. However, the results obtained by the modified method didn't differ significantly from those obtained by the standard method. Furthermore some tests were conducted to recover the remaining oil, which may be economically important, in these waste products. The oil could be recovered in the range of 70.6 to 96.4% if the wastewater was treated with lime while air was passed through the mixture, filtered using a muslin cloth disk, dried, and extracted with an organic solvent.     

A new approach to increase weld line strength of incompatible polymer blend composites: selective filler addition

A ternary blend composite composed of two immiscible organic phases, polypropylene (PP) and polyamide-6 (PA), and talc as inorganic filler is studied in terms of weld line properties and morphology. Effects of different filler levels as well as compatibilizer on weld line strength under tensile loading condition of each polymeric phase are investigated. Special attention is paid to relate the nature of dispersed domains especially in weld line regions with final performance. It is observed from scanning electron microscopy (SEM) studies that addition of talc filler which is selectively wetted by dispersed PA phase dramatically reduces the elongated domain size in the weld line region and causes to much more homogeneous microstructure. The selective wetting of talc particles by PA phase, therefore, seems to be beneficial in increasing weld line strength via increasing the viscosity of the PA dispersed phase and consequently decreasing the elongated domains at weld line region. Compared to uncompatibilized blend composites, compatibilized ones represent much higher weld line strength for all levels of talc loading.