Loop plasma and metallic antennas for mobile entities

Amethod of estimating the specific conductivity and dielectric relative dielectric permittivity of plasma antennas with mercury admixture has been proposed and investigated in two different microwave ranges. Based on the obtained data of specific conductivity and relative dielectric permittivity the radiotechnical parameters (VSWR and the efficiency) were computed via simulation and calculation of antennas in the FEKO software environment using the integral equation method and the method of moments with or without due regard for the impact of mercury admixture. For comparison plasma and metallic antennas the characteristics of similar metallic antennas were also considered. A significant difference of the above characteristics was noted. The comparison of the calculation results of VSWR of plasma antennas with experimental data revealed their acceptable agreement. This is the evidence of an adequate approach to specifying the initial data in terms of the plasma parameters and the correct computer simulation of plasma antennas in the microwave range. The radiotechnical characteristics of an L-shaped loop plasma antenna bent for the purpose of reducing the aerodynamic resistance in case of mounting antenna at mobile entities were also investigated. It is recommended to reduce the amount of mercury introduced into plasma antennas for improving the ecological situation. The method proposed can be used for taking into account the impact of other admixtures introduced into plasma antennas.     

Effect of the structure of polymer inclusion membranes on zn(II) transport from chloride aqueous solutions

This article presents application of polymer inclusion membranes (PIM) containing polymer matrices: cellulose triacetate (CTA) or poly(vinyl) chloride (PVC), o‐nitrophenyloctyl ether (NPOE) as a plasticizer and phosphonium ionic liquids, i.e., trihexyltetradecylphosphonium chloride (Cyphos IL 101), bis(2,4,4‐trimethylpentyl)phosphinate (Cyphos IL 104) and tributyltetradecylphosphonium chloride (Cyphos IL 167), as carriers for Zn(II) transport from chloride medium. Cyphos IL167 application as an ion carrier in PIMs is reported for the first time. The membrane composition is found to affect Zn(II) transport significantly. SEM and AFM images show the differences in the surface morphology of PVC and CTA based membranes. Better transport abilities of CTA membranes (Zn(II) recovery factors exceed 80%) compared with those of PVC, indicate that the structural differences between the two polymers play a crucial role for the membrane permeability. The best initial flux and permeability coefficient are obtained for the membranes with Cyphos IL 101 and Cyphos IL 104 as carriers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42319.     

An evaluation tool for design quality: PFI sheltered housing

The complex procurement process entailed by the private finance initiative (PFI) means that clients need new capacities to manage their relationships with bidders and to assess project proposals if the desired level of design quality is to be achieved. To assist local authorities in their client role, a new Architectural Design Quality Evaluation Tool was developed. The aim was to improve the quality of design in residential sheltered housing, procured through the PFI. The tool was developed for and applied to a programme that will see the replacement of a local authority's entire sheltered housing stock. The tool has two functions: (1) to inform the client's assessment process and assist with the selection of the preferred bidding consortium through a series of stages in the PFI process; and (2) to improve the quality of all the submitted designs through an iterative process. Although several existing mechanisms are available for evaluating the performance attributes of buildings, few also tackle the less tangible amenity attributes, which are vital to the feeling of home. The new tool emphasizes the amenity attributes without neglecting performance.     

Polyurethane/Polylactide-Based Electrospun Nonwovens as Carriers for Human Adipose-Derived Stromal Stem Cells and Chondrogenic Progenitor Cells

Articular cartilage dysfunctions are major cause of pain and disability and lead to serious health complications. Cell-based therapies are proposed as treatment methods for cartilage regeneration. In this study, we proposed polyurethane/poly(L-lactide-co-D, L-lactide)-based electrospun nonwovens as carriers for the delivery of human adipose-derived stromal stem cells. We found that 6:4 and 8:2 polyurethane/poly(L-lactide-co-D, L-lactide) initially enhance proliferative rate of human adipose-derived stromal stem cells, shorten their population doubling time, promote creation of functional chondrogenic nodules during chondrogenic differentiation, improve the collagen-2-to-collagen-1 protein ratio, and upregulate the expression of collagen-2 and aggrecan genes.     

The effect of organofunctional nanosilica on the cross-linking process and thermal resistance of UF resin

The paper investigates the effect of surface modification of fumed nanosilica with (3-aminopropyl)triethoxysilane (APTES) on the kinetics and thermal stability of urea-formaldehyde (UF) resin. In the course of the investigation, nanoparticles were modified with APTES in the ratio 1, 2, 3, 4 and 5 part by weight (PBW) per 100 PBW of SiO₂. The parameters of curing kinetics of the resin, the conversion degree and its thermal stability were determined with use of differential scanning calorimetry (DSC) and thermogravimetric analysis (TG). The effect of nanosilica silanization on the curing process of resin was evaluated by determining the gel time at 100 °C and the activation energy (E_a) of the cross-linking process, the initial and final temperature of the reaction (T_onset, T_endset), the maximum value of the exothermic peak (T_p), the amount of emitted heat (ΔH_Tp) and the conversion degree (α_Tp) that responds to T_p. With the maximum level of silica modification, we have noted a decrease in the reactivity of the resin, which is manifested by a slightly longer gel time of the resin as well as an increase in the value of activation energy of the cross-linking process. It is accompanied by a slight decrease of resin conversion degree α_Tp. The modification of silica, regardless of the amount of silane inoculated on its surface, results in the increase in the thermal stability of UF resin.     

Applicability of Field Plate in Double Channel GaN HEMT for Radio-Frequency and Power-Electronic Applications

Silicon - In the present communication, for the first time, applicability of Field Plate (FP) for Double Channel (DC) AlGaN/GaNHEMT is demonstrated. Impact of design space parameters such as field...