A novel circularly polarized reader antenna design for UHF RFID applications

Wireless Networks - In this article, a novel ultra-high frequency radio frequency identification (UHF RFID) reader antenna is proposed and experimentally investigated. The proposed RFID antenna...     

Carbon dioxide emission from the Turkish electricity sector and its mitigation options

In this study, electricity generation associated CO₂ emissions and fuel-specific CO₂ emission factors are calculated based on the IPCC methodology using the data of fossil-fueled power plants that ran between 2001 and 2008 in Turkey. The estimated CO₂ emissions from fossil-fueled power plants between 2009 and 2019 are also calculated using the fuel-specific CO₂ emission factors and data on the projected generation capacity of the power plants that are planned to be built during this period. Given that the total electricity supply (planned+existing) will not be sufficient to provide the estimated demand between 2011 and 2019, four scenarios based on using different fuel mixtures are developed to overcome this deficiency. The results from these scenarios show that a significant decrease in the amount of CO₂ emissions from electricity generation can be achieved if the share of the fossil-fueled power plants is lowered. The Renewable Energy Scenario is found to result in the lowest CO₂ emissions between 2009 and 2019. The associated CO₂ emissions calculated based on this scenario are approximately 192 million tons lower than that of the Business As Usual Scenario for the estimation period.     

Fungal contamination of Kashar cheese in Turkey

Fifty random samples of Kashar cheese were collected from shops in different localities in Erzurum, all contained moulds. Mean count of total surface mould was 3.02 × 10¹⁰/g cheese and that of inner mould was 3.02 × 10³/g cheese. The genera Penicillium, Aspergillus, Mucor, Rhizopus and Geotrichum sp. were isolated from cheese samples. Aflatoxins were not detected in cheese samples. Potassium sorbate inhibited mould growth and sporulation in YES broth. The public health importance and economic significance of fungal contamination, and suggested measure for cheese quality are discussed.     

Using Java and JavaScript in the Virtual Programming Laboratory: a Web-based parallel programming environment

The Virtual Programming Laboratory (VPL) is a Web-based virtual programming environment built based on a client–server architecture. The system can be accessed on any platform (Unix, PC or Mac) using a standard Java-enabled browser. Software delivery over the Web imposes a novel set of constraints on design. We outline the tradeoffs in this design space, motivate the choices necessary to deliver an application, and detail the lessons learned in the process. We discuss the role of Java and other Web technologies in the realization of the design. VPL facilitates the development and execution of parallel programs. The initial prototype supports high-level parallel programming based on Fortran 90 and High Performance Fortran (HPF), as well as explicit low-level programming with the MPI message-passing interface. Supplementary Java-based platform-independent tools for data and performance visualization are an integral part of the VPL. Pablo SDDF trace files generated by the Pablo performance instrumentation system are used for post-mortem performance visualization. © 1997 John Wiley & Sons, Ltd.     

Transparent poly(methyl methacrylate‐co‐butyl acrylate) nanofibers

Nanofibers of n‐Butyl Acrylate/Methyl Methacrylate copolymer [P(BA‐co‐MMA)] were produced by electrospinning in this study. P(BA‐co‐MMA) was synthesized by emulsion polymerization. The structural and thermal properties of copolymers and electrospun P(BA‐co‐MMA) nanofibers were analyzed using Fourier transform infrared spectroscopy–Attenuated total reflectance (FTIR–ATR), Nuclear magnetic spectroscopy (NMR), and Differential scanning calorimetry (DSC). FTIR–ATR spectra and NMR spectrum revealed that BA and MMA had effectively participated in polymerization. The morphology of the resulting nanofibers was investigated by scanning electron microscopy, indicating that the diameters of P(BA‐co‐MMA) nanofibers were strongly dependent on the polymer solution dielectric constant, and concentration of solution and flow rate. Homogeneous electrospun P(BA‐co‐MMA) fibers as small as 390 ± 30 nm were successfully produced. The dielectric properties of polymer solution strongly affected the diameter and morphology of electrospun polymer fibers. The bending instability of the electrospinning jet increased with higher dielectric constant. The charges inside the polymer jet tended to repel each other so as to stretch and reduce the diameter of the polymer fibers by the presence of high dielectric environment of the solvent. The extent to which the choice of solvent affects the nanofiber characteristics were well illustrated in the electrospinning of [P(BA‐co‐MMA)] from solvents and mixed solvents. Nanofiber mats showed relatively high hydrophobicity with intrinsic water contact angle up to 120°. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4264–4272, 2013     

Electrostatic self‐assembly dyeing of cotton fabrics

A new approach to the dyeing of cotton fabrics using an electrostatic self‐assembly method was evaluated. Cotton fabrics were pretreated with 2,3‐epoxypropyltrimethylammonuium chloride and cationic charges were produced on the fabric surfaces. For the dyeing of cotton fabric, reactive and acid dyes were used. Oppositely charged anionic reactive/acid dyes and cationic poly(diallyldimethylammonium chloride) were alternately deposited on the surface of cationised cotton fabrics. Ten multilayer films of dye/poly(diallyldimethylammonium chloride) were deposited on the cotton fabric surfaces using a padder. The build‐up of the multilayer films and the level of colour strength (K/S) achieved are discussed. Samples of cotton fabrics were also dyed with the same dyes, but using the exhaust method, and both types of dyed samples were compared. The washing, rubbing and light fastness properties were evaluated for the dyed fabrics.     

Structural modeling of end mills for form error and stability analysis

Structural modeling of end mills is crucial for predicting deflections and vibrations in milling processes. End mill geometry is very complex which makes the use of simple beam models inaccurate. Stiffness and frequency response function (FRF) measurements need to be performed to identify the static and dynamic properties experimentally. This can be very time consuming considering the number of tool–tool holder combinations in a production facility. In this paper, methods for modeling structural properties of milling tools are presented. Static and dynamic analysis of tools with different geometry and material are carried out by finite element analysis (FEA). Some practical equations are developed to predict the static and dynamic properties of tools. Receptance coupling and substructuring analyses are used to combine the dynamics of individual component dynamics. In this analysis, experimental or analytic FRFs for the individual components are used to predict the final assembly’s dynamic response. Clamping parameters between the tool and the tool holder may effect the results significantly. These parameters are also identified from the measurements. The effects of changes in tool parameters and clamping conditions are evaluated. The predictions are verified by the measurements for different conditions.     

Platelet‐in‐Box Colloidal Quantum Wells: CdSe/CdS@CdS Core/Crown@Shell Heteronanoplatelets

Here, the CdSe/CdS@CdS core/crown@shell heterostructured nanoplatelets (NPLs) resembling a platelet‐in‐box structure are developed and successfully synthesized. It is found that the core/crown@shell NPLs exhibit consistently substantially improved photoluminescence quantum yield compared to the core@shell NPLs regardless of their CdSe‐core size, CdS‐crown size, and CdS‐shell thickness. This enhancement in quantum yield is attributed to the passivation of trap sites resulting from the critical peripheral growth with laterally extending CdS‐crown layer before the vertical shell growth. This is also verified with the disappearance of the fast nonradiative decay component in the core/crown NPLs from the time‐resolved fluorescence spectroscopy. When compared to the core@shell NPLs, the core/crown@shell NPLs exhibit relatively symmetric emission behavior, accompanied with suppressed lifetime broadening at cryogenic temperatures, further suggesting the suppression of trap sites. Moreover, constructing both the CdS‐crown and CdS‐shell regions, significantly enhanced absorption cross‐section is achieved. This, together with the suppressed Auger recombination, enables the achievement of the lowest threshold amplified spontaneous emission (≈20 μJ cm^?2) from the core/crown@shell NPLs among all different architectures of NPLs. These findings indicate that carefully heterostructured NPLs will play a critical role in building high‐performance colloidal optoelectronic devices, which may even possibly challenge their traditional epitaxially grown thin‐film based counterparts.