The paper discusses the use of multiclustering statistical analysis in the assessment of domestic wastewater filtration effectiveness. Calculations included data collected over four months of experiments with using waste as filling material of vertical flow filters for domestic sewage treatment. The effectiveness of pollutants removal was analysed in case of me-chanically shredded waste in the form of PET flakes, PUR foam trims, shredded rubber tires and wadding. The organic compounds (CODcr, BOD5) removal, suspend solids, biogens (as NH4+, PO43– ions) and oxygen saturation changing com-pared with sand filling was analysed. Multiclustering statistical analysis allowed to divide pollutants removal efficiency of analysed materials into 3 clusters, depending on the hydraulic loading. The first group consisted in quality parameters of treated sewage: the highest reduction of BOD5 and NH4-N. It included the values of quality parameters and indicators for the filtrates obtained at the lowest hydraulic load from columns filled with 60 cm of rubber tires or sand. The second group comprised the results for fillings containing foam, PET and rubber tires (the other hydraulic loads).It featured the highest reduction of total suspended solids and PO43–. Removal of easily biodegradable organic compounds was at a similar level in both cluster groups. The filter filled with polyester waste (wadding), which was as effective as 30 cm layer of sand, and the filters filled with 60 cm of sand working at the highest hydraulic load. Third group showed the lowest values of parameters and indicators for analysed filtrates.

The main objective of this study was to evaluate the intensity and character of the inflammatory reaction caused by an innovative polyester-polyurethane vascular prosthesis implanted into the abdominal aorta of 9 Beagle dogs aged 1-3 years. At 6 and 12 months post implantation the prostheses were removed and tissues samples were examined using 2 methods: histology and immunohistochemistry (IHC). Histology slides stained with hematoxylin and eosin (H&E) were evaluated for the intensity of inflammation by observing the density of inflammatory cells and graded 1 to 4 (1- light inflammation, 4 – severe inflammation). The pro-inflammatory mediator tumor necrosis factor-alpha (TNFα) and two anti-inflammatory mediators, interleukin 1 receptor antagonist (IL1ra), and interleukin 10 (IL10), were also assessed in the tissue samples by IHC methods. Mean (n=5) inflammation grade in H&E slides at 6 months post-implantation (6Mpost) was 2 and mean (n=4) inflammation grade at 12 months (12Mpost) was almost 3. IHC staining showed that TNFα and IL1ra in tissue samples obtained from 6Mpost dogs were expressed at the same intensity indicating equal pro- and anti-inflammatory cytokine levels. However, in the 12Mpost tissues TNFα was expressed more intensely than IL1ra and IL10. Moreover, in 2 dogs at 12Mpost, there were signs of infection assessed on the basis of neutrophil infiltration in the prostheses. In conclusion, the assessment of pro-inflammatory mediators such as TNFα and anti-inflammatory mediators, such as IL1ra and IL10, can help to interpret the intensity of the inflammatory process directed at synthetic prostheses.

Poly(glycerol succinate) – PGSu – is one of glycerol polyesters which has focused nowadays the interest of scientists developing new biomaterials. Probably the polyester could be used as a drug carrier or as a cell scaffold in tissue engineering. Due to its potential use in medicine, it is extremely important to develop a synthesis and then optimize it to obtain a material with desired properties. In this work one flask two-step polycondensation of glycerol and succinic anhydride to PGSu is presented. Synthesis was optimized with the simplex method and also described using a second-degree equation with two variables (temperature and time) to better find the optimum conditions. PGSu was characterized by FTIR spectroscopy, NMR spectroscopy, degree of esterification was determined, and also molecular weight was calculated for each experiment using Carothers equation. A new synthesis route was developed and optimized. Temperature and time influence on molecular weight and esterification degree of obtained polyester are presented. Based on experiments conducted in this work, it was possible to obtain poly(glycerol succinate) with molecular weight of 6.7 kDa.

In high technologies today, wearable devices have become popular. Wearable technology is a body sensing system that supports application of health observance and tracking through a wearable Global Positioning System (GPS). The design of the patch antennas is highly significant for the brilliance of the wearable patch antennas. This paper focuses on analyzing the bending effect on return loss and frequency between three types of GPS patch antenna. Types of GPS patch antennas that have been designed in this project are with different substrates and different designs. The wearable patch antenna has been designed and analyse using CST software. As a result, able to analysis the reflection coefficient (S11), radiation patterns, and analytical approach for patch antenna bending effect were obtained.

Polyester coatings are among the most commonly used types of powder paints and present a wide range of applications. Apart from its decorative values, polyester coating successfully prevents the substrate from environmental deterioration. This work investigates the cavitation erosion (CE) resistance of three commercial polyester coatings electrostatic spray onto AW-6060 aluminium alloy substrate. Effect of coatings repainting (single- and double-layer deposits) and effect of surface finish (matt, silk gloss and structural) on resistance to cavitation were comparatively studied. The following research methods were used: CE testing using ASTM G32 procedure, 3D profilometry evaluation, light optical microscopy, scanning electron microscopy (SEM), optical profilometry and FTIR spectroscopy. Electrostatic spray coatings present higher CE resistance than aluminium alloy. The matt finish double-layer (M2) and single-layer silk gloss finish (S1) are the most resistant to CE. The structural paint showed the lowest resistance to cavitation wear which derives from the rougher surface finish. The CE mechanism of polyester coatings relies on the material brittle-ductile behaviour, cracks formation, lateral net-cracking growth and removal of chunk coating material and craters’ growth. Repainting does not harm the properties of the coatings. Therefore, it can be utilised to regenerate or smother the polyester coating finish along with improvement of their CE resistance.

Damage occurring on a reinforced concrete beam (e.g. spalling) can reduce beam’s capacity to withstand external loads. The damage becomes more critical if it is occurred in the shear span since it may lead to shear failure. Patching to the damage zone by suitable patch repair material could be the best option in restoring the shear capacity of the beam. This research investigates the shear recovery of patched reinforced concrete beams with web reinforcement. The patching material used is unsaturated polyester resin mortar. The shear recovery is assessed on the basis of the patched beam’s behavior under flexure-shear load in comparison with those of normal beams. The behavior observed include cracking failure mode, strains of the reinforcements, and load-deflection behavior. The results indicate that the UPR mortar is capable to restore the strength of the damage reinforced concrete beam. The characteristic of UPR mortar (low elastic modulus and high strength) can be the origin of the overall behavior of the patched reinforced concrete beams.

The scope of the paper is to determine the mechanical properties of the Precontraint 1302 polyester coated fabric under uniaxial and biaxial tensile tests. The results are compared for Precontraint 1302 fabric and other types of coated fabrics. The author applied an orthotropic model and a dense net model to reflect the polyester coated fabric performance under uniaxial and biaxial tensile tests. Material parameters are specified for both constitutive models. In order to observe the variation of immediate mechanical properties, the biaxial cyclic tests are performed for different load ratios. During uniaxial and 1:1 biaxial tensile tests it is barely observable to recognize warp or weft directions on the stress-strain curves. Load history acts strongly on the mechanical properties of the Precontraint 1302 polyester fabrics. The cyclic loads cause variation of immediate longitudinal stiffness with a comparison of values determined for unloaded coated fabrics. The paper can provide scientists, engineers, and designers an experimental and theoretical basis in the field of polyester coated fabrics.

This research aims to determine the influence of water-soaking on polyester-based coated woven fabrics for ultimate tensile strength and elongation at break under uniaxial tensile tests. The paper begins with a short survey of literature concerning the investigation of the determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of a flat grip to establish the values of the ultimate tensile strength of groups of specimens treated with different moisture conditions. SEM fractography is performed to determine the cross-section structures of coated woven fabrics. The change in the mechanical properties caused by the influence of water immersion has not been noticed in the performed investigations.

Composite materials are a constantly evolving group of engineering materials, which has significantly changed their current, and potential role as structural materials over the past decades. Composites offer greater strength, stiffness, and less deformation to structural designers than previously available engineering materials. Resin matrix composites are widely used in the transportation, marine, aerospace, energy, and even sports industries. The manufacturing stage has a profound influence on the quality of the final product. This paper presents the production of composite materials by gravity casting in silicone moulds, using an epoxy/polyester resin matrix reinforced with wood chips and shredded glass fiber reinforced composite from recycled wind turbine blades. Some of the fabricated samples were degassed in a reduced-pressure chamber. The mechanical properties of the produced material were then examined. It was noted that the silicone moulds did not affect the resin self-degassing due to the large surface area to weight ratio, and the remaining small air bubbles had a limited effect on the mechanical properties of the samples. The filler used also played a significant role. Composites filled with crushed GFRC showed better strength properties than composites filled with wood chips. The conducted research is aimed at selecting materials for further testing with a view to their use in the manufacture of next-generation wood-based composite structural materials.