Synthesis and characterization of water‐dispersed flame‐retardant polyurethane resin using phosphorus‐containing chain extender

In this research, a flame‐retardant water‐dispersed polyurethane resin was synthesized through incorporating phosphonate groups into the polyurethane structure in the chain‐extension step. A phosphorus‐containing reactive flame‐retardant compound was synthesized for this purpose. First, bis(4‐nitrophenyl)phenyl phosphine oxide was synthesized and then converted to bis(4‐amino phenyl)phenyl phosphine oxide (BAPPO) by reducing its nitro groups into amines. The obtained products were characterized by IR, ¹H‐NMR, and ³¹P‐NMR, and the thermal properties of the polymers were determined by DSC analysis. The BAPPO‐containing polyurethane showed physical properties that were almost similar to those of phosphorus‐free polyurethane and exhibited good flame resistance with a limiting oxygen index value of 27. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1314–1321, 2004     

Rapid prototyping of a miniaturized Electrospinning setup for the production of polymer nanofibers

Fabrication of polymeric micro/nanofibers with controllable size, density, orientation, and composition is required for their translation into functional devices and materials. Electrospinning (ES) is a frequently used fiber fabrication technique, where ES parameters such as the applied electric field strength, architecture of the setup, and solution composition are manipulated to control the fiber properties. Here, we present a bench‐top method for fabricating miniaturized, integrated, and highly tunable ES setups based on shrinkable polymer substrates. We show that using a combination of numerical modeling and controlling different parameters in the ES setup, including the spinneret to collector distance, and spinneret and collector designs, it is possible to tune the density, alignment, and orientation of electrospun fibers. In this way, we have produced 300–600 nm wide poly(ethylene oxide) fibers arranged as nonwoven mats on planar electrodes, aligned fibers on electrode edges, and individual suspended fibers spanning gaps between collector electrodes. The ability to rapidly prototype ES setups should enable us to study the effects of spinneret–collector configurations on fiber morphology, distribution, and conformation and to aid in the development of miniaturized ES setups designed to serve specific applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40629.     

Radiobiological and Treatment-Related Aspects of Spatially Fractionated Radiotherapy

The continuously evolving field of radiotherapy aims to devise and implement techniques that allow for greater tumour control and better sparing of critical organs. Investigations into the complexity of tumour radiobiology confirmed the high heterogeneity of tumours as being responsible for the often poor treatment outcome. Hypoxic subvolumes, a subpopulation of cancer stem cells, as well as the inherent or acquired radioresistance define tumour aggressiveness and metastatic potential, which remain a therapeutic challenge. Non-conventional irradiation techniques, such as spatially fractionated radiotherapy, have been developed to tackle some of these challenges and to offer a high therapeutic index when treating radioresistant tumours. The goal of this article was to highlight the current knowledge on the molecular and radiobiological mechanisms behind spatially fractionated radiotherapy and to present the up-to-date preclinical and clinical evidence towards the therapeutic potential of this technique involving both photon and proton beams.     

A conducting composite of polythiophene: synthesis and characterization

Conducting polymer composites of polythiophene, using a polyamide as the insulating matrix, were prepared via electrochemical methods. The characterization of the composite was done by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared and pyrolysis studies. The conductivities were measured by a four-probe technique. The cited methods revealed that the composites have properties different from those of simple mechanical mixtures of the two polymers.     

Valorisation of almond shell waste in ultrasonic biomordanted dyeing: alternatives to metallic mordants

An agroindustrial waste, outer green shell of almond fruit has been valorised as a novel natural dye using chemical solvent-free extraction, small amount of metallic mordants, one-bath biomordanted dyeing, ultrasonic medium, auxiliary-free dyeing and washing. The main objective of this study is to evaluate biomordants vs. metallic mordants depending on heating system both in extraction and dyeing and to reveal alternatives to metallic mordants. Effects of conventional- and ultrasound-assisted systems on dyeing and fastness properties were investigated. Wool fabrics dyed using metallic mordants (alum, iron II sulphate, copper II sulphate and potassium dichromate) were compared with the samples dyed in conjunction with biomordants [powder of valex (acorn of Quercus ithaburensis ssp. macrolepis), pomegranate (Punica granatum L.) rind, rosemary (Rosmarinus officinalis) and thuja (Thuja orientalis) leaves] in terms of colour yield, colour coordinates and fastness properties. Heating system had significant effects on dyeing and fastness results. Power ultrasound did not present any advantage in colour yield increment while it presented different effects on fastness values depending on mordant and process type of which ultrasound was applied. Some biomordants could be replaced with metallic mordants depending on their types and heating system. They could produce completely different colour gamuts just like metallic mordants.     

An example of facade colour design of mass housing

The colours and architectural characteristics of building facades are the major factors affecting the general appearance of cities. When cities are examined from various perspectives, first impressions are obtained from the geometrical forms and facade colours of buildings. The facade colour arrangements should reflect the features of the region and buildings. In this context various features of natural and artificial environments such as plant life, water elements, climate, and historical texture should be examined, and a facade colour arrangement should be designed according to the examination results. In addition, the other factors effective in determining the colour and style of a building, such as social‐cultural background of the society and traditional and natural building materials, should not be forgotten because in some regions traditional buildings with special construction styles, materials, and colours create a specific identity for the settlements and cities. The aims of this article are to elucidate the colour contrast, colour arrangement, and colour design stages of mass housing and to explain the colour design of Bizimkent Mass Housing, which was constructed in a new dwelling zone in Istanbul, Turkey, as an example of such an arrangement. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 291–299, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10068     

Quantum transport of pseudospin-polarized Dirac fermions in gapped graphene nanostructures

We investigate the unusual features of the quantum transport in gapped monolayer graphene, which is in a pseudospin symmetry-broken state with a net perpendicular pseudomagnetization. Using these pseudoferromagnets (PFs), we propose a perfect pseudospin valve effect that can be used for realizing pseudospintronics in monolayer graphene. The peculiarity of the associated effects of pseudospin injection and pseudospin accumulation are also studied. We further demonstrate the determining effect of the sublattice pseudospin degree of freedom on Andreev reflection and the associated proximity effect in hybrid structures of PFs and a superconductor in S/PF and PF/S/PF geometries. In particular, we find a peculiar Andreev reflection that is associated with an inversion of the z component of the carriers pseudospin vector. Our results show that the gapped normal graphene behaves like a ferromagnetic graphene and the effect of the pseudospin degree of freedom in gapped graphene is as important as the spin in a ferromagnetic graphene.     

Neural network control for earthquake structural vibration reduction using MRD

Structural safety of building particularly that are intended for exposure to strong earthquake loads are designed and equipped with high technologies of control to ensure as possible as its protection against this brutal load. One of these technologies used in the protection of structures is the semi-active control using a Magneto Rheological Damper device. But this device need an adequate controller with a robust algorithm of current or tension adjustment to operate which is further discussed in the following of this paper. In this study, a neural network controller is proposed to control the MR damper to eliminate vibrations of 3-story scaled structure exposed to Tōhoku 2011 and Boumerdès 2003 earthquakes. The proposed controller is derived from a linear quadratic controller designed to control an MR damper installed in the first floor of the structure. Equipped with a feedback law the proposed control is coupled to a clipped optimal algorithm to adapt the current tension required to the MR damper adjustment. To evaluate the performance control of the proposed design controller, two numerical simulations of the controlled structure and uncontrolled structure are illustrated and compared.     

Second law analysis of wind turbine power plants: Cesme, Izmir example

In this study, the energy and exergy efficiency results of the Wind Turbine Power Plants (WTPPs) are presented. Exergy, energy and technical availability analysis are performed. The case study includes the actual system data taken from the system in Cesme, Izmir WTPP. General energy, exergy and other performance parameters are also presented. Investigated WTPP is Turkey’s first installed (1998) wind plant (1.50 MW) located in Izmir. Exergy efficiency of the power plant found to be between 0% and 68.20%. The monthly average technical availabilities are 96.11%, 98.71%, 98.52% for turbine 1, turbine 2, and turbine 3, respectively. Furthermore, authors developed some correlations, which are capable of predicting the values of exergy efficiencies of the WTPP for different power factor value.