Monte Carlo analysis of ridged waveguides with transformation media

A computational model is presented for Monte Carlo simulation of waveguides with ridges, by combining the principles of transformation electromagnetics and the finite methods (such as finite element or finite difference methods). The principle idea is to place a transformation medium around the ridge structure, so that a single and easy‐to‐generate mesh can be used for each realization of the Monte Carlo simulation. Hence, this approach leads to less computational resources. The technique is validated by means of various finite element simulations in the context of 3D waveguides of uniform cross‐section. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

Evaluating the nursing academicians in Turkey in the scope of Web of Science: scientometrics of original articles

Scientometrics - Scientometrics, bibliometrics, webometrics, and informetrics are specific research fields that cover statistical analyses of a particular research field which summarize the...     

Offshoring manufacturing: Implications for engineering jobs and education: A survey and case study

One result of globalization is the rapid growth of offshoring, i.e., the outsourcing of functions and jobs to offshore locations. In the USA, offshoring has progressed to the point where it already affects everyday lives, from the cars we drive (of which a large portion of the work and components are outsourced) to computers (which are typically manufactured offshore and shipped back to the USA), to electronic diagnostics (where calls are answered overseas). This phenomenon has implications on our lives and on the jobs that engineers and scientists will assume both now and in the future. Further, it is something that all highly developed and even some lesser-developed countries must face. Consequently, the growth of outsourcing will have a major impact on the educational objectives of engineering programs and the resultant engineering curricula worldwide.

This paper presents recent data on product and job offshore migrations and discusses the various dimensions of this phenomenon. In addition to the potential loss of engineering and other high-end technical jobs, sociological and cultural aspects, intellectual property issues, strategic planning concerns, and macro-economic issues are presented. For example, the effects of offshoring on the societal fabric of the countries that are recipients of manufacturing and service center outsourcing, such as China and India, are significant, rapid, and controversial. Offshoring has also begun to change the way that engineering programs in these countries educate their students. In addition, intellectual property issues create a major risk to companies considering outsourcing to certain less-developed countries. These issues can be broadly categorized into: the robustness and strength of intellectual property laws, and the degree to which these laws are implemented and enforced. Further, such factors as currency fluctuations and geo-political conditions can substantially impact outsourcing decisions and profitability.

The phenomenon of offshoring, which is now affecting engineering careers, will play a major role in shaping engineering education worldwide. The next generation of engineers will need to possess the ability to work seamlessly across cultures, have outstanding communication skills and be familiar with the principles of project management, logistics, and systems integration. Some educational models that begin to address these requirements will be presented.     

Original Fuel‐Cell Membranes from Crosslinked Terpolymers via a “Sol–gel” Strategy

Hybrid organic/inorganic membranes that include a functionalized (‐SO₃H), interconnected silica network, a non‐porogenic organic matrix, and a ‐SO₃H‐functionalized terpolymer are synthesized through a sol–gel‐based strategy. The use of a novel crosslinkable poly(vinylidene fluoride‐ter‐perfluoro(4‐methyl‐3,6‐dioxaoct‐7‐ene sulfonyl fluoride)‐ter‐vinyltriethoxysilane) (poly(VDF‐ter‐PFSVE‐ter‐VTEOS)) terpolymer allows a multiple tuning of the different interfaces to produce original hybrid membranes with improved properties. The synthesized terpolymer and the composite membranes are characterized, and the proton conductivity of a hybrid membrane in the absence of the terpolymer is promising, since 8 mS cm^?1 is reached at room temperature, immersed in water, with an experimental ion‐exchange‐capacity (IEC_exp) value of 0.4 meq g^?1. Furthermore, when the composite membranes contain the interfaced terpolymer, they exhibit both a higher proton conductivity (43 mS cm^?1 at 65 °C under 100% relative humidity) and better stability than the standard hybrid membrane, arising from the occurrence of a better interface between the inorganic silica and the poly[(vinylidene fluoride)‐co‐hexafluoropropylene] (poly(VDF‐co‐HFP)) copolymer network. Accordingly, the hybrid SiO₂‐SO₃H/terpolymer/poly(VDF‐co‐HFP) copolymer membrane has potential use as an electrolyte in a polymer‐electrolyte‐membrane fuel cell operating at intermediate temperatures.     

The false positive effect of residue of sulphur sources on dithiocarbamate analysis based on CS2 measurement

Turkey plays an important role in the international trade of apricots as it has the largest production rate in the world. Since the sulphurisation process is allowed to be used for different products, the effect of residual sulphur and its compounds (which can be found in products as pesticide residues or additive residues) on the positive detection of carbon disulphide (CS₂) still creates a big challenge in international trade. Therefore, the main objective of the present study was to investigate the effects of residues of sulphur or sulphur compounds on dithiocarbamate analysis methods based on CS₂ measurement. In this study, apricots were chosen since they contain sulphur residues as a result of the sulphurisation process. Sulphur dioxide and dithiocarbamate analyses were conducted on dried apricots prepared with the sulphurisation process (SA) and without the sulphurisation process (NSA); analysis was by two different accredited laboratories. No of pesticide was applied to either SA or NSA samples. Although some of the NSA samples had <LOQ values, approximately 70 ± 32 mg/kg SO₂ and 0.061 ± 0.021 mg/kg dithiocarbamate were detected for NSA samples. On the other hand, for the SA sample group, 927–2915 mg/kg of SO₂ and 0.265–0.825 mg/kg of dithiocarbamate were detected. Furthermore, a strong correlation between residual sulphur and dithiocarbamate values was observed. This study showed that the analysis method based on CS₂ measurement may lead to false positive results for dithiocarbamates when residues of sulphur or sulphur compounds are found in products as pesticide or additive residues. Therefore, residual sulphur compounds as a result of the sulphurisation process (which is not considered during the evaluation of products) must be taken into account during the evaluation of products for dithiocarbamates.     

Pilot study on lower nitrosamine smokeless tobacco products compared with medicinal nicotine.

Smokeless tobacco (ST) products have the potential to be used as a harm reduction method for cigarette smokers. These products can deliver significantly less toxicants than cigarettes, although they are not toxicant free nor harmless. It is important to examine potential health risks and benefits of these products. These two small pilot studies examined the effects of two different ST products (Exalt and Ariva) compared with medicinal nicotine, another potential harm reduction product. Dependent, healthy adult cigarette smokers, who were motivated to quit smoking, underwent 1 week of baseline smoking measurement. They were then asked to quit smoking and were randomly assigned to use either an ST product or a medicinal nicotine lozenge (MNL, Commit) for 2 weeks, then crossed over to use the other product for 2 weeks. In the last week, following the sampling phase, subjects could choose the product they wished to use. Assessments were made repeatedly during baseline cigarette use and throughout the 5 weeks of treatment. Outcome measures included biomarkers for tobacco exposure and subjective, physiological, and behavioral responses. Tobacco-specific carcinogen uptake was greater from Exalt than from the MNL, and was comparable between the MNL and Ariva. Physiological effects and subjective effects on withdrawal and craving were comparable among Exalt, Ariva, and the MNL. Ariva was preferred over the MNL, which was preferred over Exalt. With the exception of medicinal nicotine products, low-nitrosamine ST products have the greatest potential to result in reduced toxicant exposure compared with other combustible reduced exposure products and have promise for reducing individual risk for disease. However, the population effect of marketing of such products as reduced exposure/reduced risk is unknown. The need for further research in this area and regulation of tobacco products is evident.     

Effect of alkali metal hydroxides on the morphological development and optical properties of ceria nanocubes under hydrothermal conditions

Nanocrystalline cerium(LV) oxide (CeO2, ceria) particles were produced via the hydrothermal treatment of cerium nitrate hexahydrate with various alkali metal hydroxides (MOH: M = Li, Na, K). Experimental conditions such as [MOH], reaction temperature, and reaction time were studied. Particle morphology as well as size of crystallites was precisely controlled by choice of experimental conditions. While rod-shaped particles were obtained at 120 degrees C, well-defined nanocubes were formed at higher temperatures regardless of the choice of MOH. Examination of particle growth kinetics, in the final stages of crystallization, showed that particle growth rate is controlled by two different mechanisms. Grain boundary diffusion controls the particle growth in the presence of NaOH with an activation energy of 113.8 kj/mol and surface diffusion for LiOH ad KOH with the activation energy of 43.0-150.9 kj/mol, respectively. In addition, the particles exhibit strong violet and blue emissions at 400 nm and 370 nm. The former emission originates from excitation of a wide band gap of CeO2. The latter one is attributed to the trivalency of the cerium ion and appears to be sensitive to all the experimental conditions studied. Both extending reaction time and increasing temperature reduce the intensity of the 370 nm emission and increase the intensity of the 400 nm emission.     

Learning from traditional built environment of Cyprus: Re-interpretation of the contextual values

Last century witnessed the tragic results of ethnic separations between Turkish and Greek Cypriots, which were the two main communities of Cyprus Island. Both communities; that used to live mixed together on the same geography, shared the same history, culture, lifestyle and moreover the future. Nowadays, the bi-communal efforts on the Island, encouraged by the international society, provide the opportunity to union and heal the traces of the traumatic division. The new century promises a rapid increase in the welfare of Cypriots parallel to the solution of the political dispute. The sudden change in economical structure can increase the threat on the unique traditional environment as a result of unplanned and inevitable developments for fulfilling the rising demands. For the sake of having a contemporary living milieu, the traditional environment as the common architectural heritage of the Island can be revitalized, besides developing new appropriate architectural solutions in the light of the natural and cultural context. The Island's housing tradition bears the opportunity to be learned from the tried and evolved architectural solutions. Evaluating these values parallel to today's discourse, sustainable identity can be achieved by emphasizing especially the locality. In brief, this study tries to define the appropriate design principles for the contemporary housing developments and finds the ways of sustaining existing unique traditional patterns.