Psychosocial aspects of children and families treated with hemodialysis

Introduction: The aim of this study was to analyze the selected psychosocial aspects of chronic kidney disease in children treated with hemodialysis (HD). Methods: The study included 25 children treated with HD aged 2 to 18 years and their parents. Data concerning the illness and socio‐demographic parameters was collected. We used the Paediatric Quality of Life Inventory (PedsQL) for patients and for their parents the PedsQL‐proxy version, General Health Questionnaire (GHQ‐12), Berlin Social Support Scales (BSSS), and the Caregivers Burden Scale (CBS) to evaluate health‐related quality of life (QoL) of HD children and their primary caregivers. Findings: In the PedsQL test, the QoL of HD children was lower than in healthy children. Children treated with HD assessed their QoL on the PedsQL questionnaire higher than the primary caregivers, on all subscales as well as an overall health‐related QoL. Scoring below 2 on the GHQ‐12 test was reported in 56% of mothers, which may indicate that psychological symptoms have intensified. There was no correlation between BSSS, CBS, and GHQ‐12. Discussion: The assessment of QoL in pediatric patients would allow for the earliest possible identification of their nonsomatic problems and irregularities. This could, consequently, contribute to improving QoL in both children with chronic kidney disease and their families.     

Modelling concurrency with comtraces and generalized comtraces

Comtraces (combined traces) are extensions of Mazurkiewicz traces that can model the “not later than” relationship. In this paper, we first introduce the novel notion of generalized comtraces, extensions of comtraces that can additionally model the “non-simultaneously” relationship. Then we study some basic algebraic properties and canonical representations of comtraces and generalized comtraces. Finally we analyze the relationship between generalized comtraces and generalized stratified order structures. The major technical contribution of this paper is a proof showing that generalized comtraces can be represented by generalized stratified order structures.     

Analysis of fluid flow and energy transport in Czochralski's process

In this paper the conjugate fluid flow and energy transport problem (involving conduction-convection-radiation heat transfer) resulting from the Czochralski crystal growth process is analysed. The solidifying material is treated as a pure and semitransparent substance with material properties depending neither on temperature nor on the wavelength. The solution of the problem is obtained iteratively using two computer codes: FLUENT, a commercial CFD package, and BEM-based in-house code capable of analysing the radiative heat transfer in the entire computational domain.Obtained results not only show velocity field and temperature distribution within the bodies under consideration but also demonstrate the influence of thermal radiation on these quantities.     

Surfactant free fractions of metallic and semiconducting single-walled carbon nanotubes via optimised gel chromatography

We report the procedure of sorting/purification of carbon nanotubes by electronic type using chromatographic column with sodium dodecylsulfate (SDS) and sodium deoxycholate (DOC) solutions as the eluents. The non-commercial agarose gel in different concentrations has been tested in the process. It was found that in optimal gel concentration the fractionation resulted in ～96.2% yield of semiconducting species. Importantly, to get surfactant-free fractions the post-separation purification procedure has been carried out. The UV–vis–NIR and Raman spectroscopy have been utilised for the samples analysis. High resolution transmission microscopy and thermogravimetric analysis allowed to study the sample morphology and purity, respectively.     

Mechanism of MxOy nanoparticles/CNTs for catalytic carbonization of polyethylene and application to flame retardancy

Three kinds of metal oxide nanoparticles (Fe₃O₄, Co₃O₄, and Ni₂O₃) are produced on carbon nanotubes (CNTs). The synergistic effects rendered by the CNTs and metal oxide nanoparticles on carbonization of polyethylene (PE) are studied and applications to flame retardancy of PE are investigated systematically. The CNT‐Ni₂O₃ delivers the best performance and the mechanism pertaining to the enhanced flame retardancy is proposed and discussed. It is found that under the same conditions, the carbonization rate can be a factor to influence the flame retardancy performance. Among Fe, Co, and Ni, Ni has the fastest carbonation rate, which leads to the best flame retardancy performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45233.     

Unsaturated ester resins

Vinyl ester resins (VERs) are often described as a cross between unsaturated polyester resins and epoxy resins. VERs offer an upgrade to epoxy resins, and they tend to be selected when chemical and temperature resistance is required. This research was aimed at developing the synthesis of unsaturated ester resins (UERs), which are similar to VERs. UERs were synthesized by the addition of dihydrodicyclopentadienyl hydrogen maleate to the terminal epoxy groups in low‐molecular‐weight bisphenol A/epichlorohydrin epoxy resins. The effect of urethanization of UERs on the properties of the crosslinked polymer was also investigated. As crosslinking monomers, styrene and glycol dimethacrylates were used. The following properties of cured UERs were determined: the heat deflection temperature, alkali resistance, and the mechanical strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2627–2631, 2006