The Usage and Perception of Pedestrian Zones in Lithuanian Cities: Multiple Criteria and Comparative Analysis

As pedestrian zones are public spaces in urban areas, they are important in terms of meeting people’s needs. However, it is worth noting that attention should be paid not only to the development of the physical infrastructure, but also to a sustainable balance between the socio-economic and environmental aspects. To guide urban planning and management initiatives towards more sustainable patterns, it is essential to re-examine the already existing characteristics of cities, establishing how they are used and perceived by inhabitants. The present research suggests environmental, economic and social criteria that determine a greater vitality of pedestrian zones in cities and better life quality for the inhabitants. A questionnaire survey was used to assess common attitudes regarding the research topic in major cities in Lithuania. The multiple criteria decision-making COPRAS (COmplex PRoportional ASsessment) method was used for the formation of a priority queue. The research results showed the attitudes of inhabitants towards pedestrian zones in Vilnius, Kaunas and Klaip˙eda. The inhabitants of these three cities regarded social and environmental criteria groups as the most significant. Contrary to what was expected and anticipated, respondents do not consider economic criteria as playing a key role in the sustainable preservation and development of pedestrian zones

Silicone Rubber and Microcrystalline Cellulose Composites with Antimicrobial Properties

The goal of this study was to create polydimethylsiloxane (PDMS) and microcrystalline cellulose (MCC) composites with high mechanical properties and antimicrobial activity. Vinyl-terminated PDMS was mixed with bifunctional filler, which combines MCC stiffness and antimicrobial properties of silver nanoparticles. To provide antimicrobial properties the silver nanoparticles in situ were synthesized by chemical reducing method in MCC aqueous suspension. Silver nanoparticles (AgNPs) concentration deposited on MCC particles surface was varied. The morphology, antimicrobial activity and mechanical properties of PDMS/MCC composites and their components have been investigated. It was shown that the combination of MCC/AgNPs as a filler and PDMS as matrix advantages bring multifunctional properties to polymer matrix composite. DOI: http://dx.doi.org/10.5755/j01.ms.20.1.4397</p

UV-Curable Aliphatic Silicone Acrylate Organic–Inorganic Hybrid Coatings with Antibacterial Activity

The most effective means to protect against bacterial invasion and to reduce the risk of healthcare-associated infections are antibacterial components synthesis. In this study, a novel process for the synthesis of organic–inorganic hybrid coatings containing silver nanoparticles is presented. Silver nanoparticles and polymer formation proceeds simultaneously through the in situ photoreduction of silver salt to silver nanoparticles and UV-crosslinking of bifunctional aliphatic silicone acrylate. The nanocomposite films with 0.5–1.43 wt % of silver nanoparticles concentration were obtained and investigated. The formation of silver nanoparticles in polymer matrix was confirmed via UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy, scanning electron spectroscopy, and energy dispersive spectroscopy. Our investigations clearly show the formation of silver nanoparticles in silicone acrylate network. Direct photoreduction of silver salt by UV-radiation in the organic media produced silver nanoparticles exhibiting cubic crystal structure. The size of nanoparticles was determined to be near 20 ± 5 nm. The antibacterial activities of coatings were determined using the disc diffusion and direct contact methods. UV-curable silicone acrylate hybrid coatings exhibited antibacterial activity against harmful bacteria strains

Characteristics of passenger flow mapping (based on international bus routes)

This work analyzes the international bus passenger flows from Vilnius to European cities at 2015 - 2016 m. autumn/winter time using the cartographic methods. Passenger flow surveys are an important for passenger transport companies as a marketing part. Using these surveys, the information obtained helps to organize high-quality and efficient service to passengers: adjust the existing routes, or to open a new ones. Unfortunately, cartographic surveys of passenger flows, as a research object little analyzed and most of the passengers flow maps are drawn for statistical purposes and published atlases. The main aim of the final master paper is to contribute to passenger flow mapping diversity and quality improvement. Therefore, the specific aim of this work is to identify the potentiality of passenger flow mapping on international bus routes by creating a new one. To achieve the aim was formulated four tasks: to analyze the previous surveys about passengers flows, to analyze the cartographic techniques for passengers flow mapping, to create a passengers flow map from Vilnius to Europe cities in 2015 – 2016, and using created map to perform geographic analysis of passenger flow. Various working methods were used for the analysis such as literature analysis, cartographic analysis, logical modeling. In the theoretical part of the work was first introduced the methodology of literature analysis, this part explains the position of international bus routes in Lithuanian transport system, clarifies the concept of passenger flows and provides mapping techniques. The part also explains the past and the current situation about the international travels by bus in Lithuania. The second part of this theoretical analysis shows the overview of the previous non-cartographic and cartographic studies. The second part of the final master paper describes the methodology of passengers flow mapping. It was first described the collecting of statistics about passengers and primary data analysis techniques. In this part was also presented the stages of mapping and the cartographic techniques. The last part of this work consists of description of created maps and geographical analysis of passenger flows maps. As a result it was created two passenger flow maps using signs of movement method. The first map shows all passenger flows from Vilnius to Europe cities, the other - the largest passenger flows. Localized diagrams method in the maps shows the distribution of passenger flows by gender, age and nationality. The geographic analysis of the map revealed that the largest passenger flows from Vilnius in 2015 - 2016 was to Minsk, Riga, Ashmyany, Kiev, Warsaw, Berlin, Tallinn and Lvov. To Belarus and Ukraine mostly went Belarus and Ukraine citizens. To western countries and to Baltic states mostly went a variety of passengers according gender, age and citizenship

Epoxy Resin and Polyurethane Compositions from Glycolized Poly (ethylene terephthalate) Wastes

The possibility to use poly(ethylene terephthalate) (PET) bottles production waste as raw material for compositions with high adhesion ability has been investigated. PET waste was glycolyzed with polypropylene glycol and three kinds of oligoesters were formed after depolymerization reaction. The polydispersity of product formed was 1.05. The possibilities to use PET glycolysis products – oligoesters for epoxy resin and polyurethanes were studied. Two-step reaction of oligoesters with epichlorohydrin was chosen for epoxy resin synthesis, while glycolyzed PET reaction with aliphatic isocyanate was used for polyurethane synthesis. The structure and properties of the obtained polymers were investigated. <p>DOI: <a href="http://dx.doi.org/10.5755/j01.ms.19.3.5237">http://dx.doi.org/10.5755/j01.ms.19.3.5237</a></p

Control of Polydimethylsiloxane Surface Hydrophobicity by Plasma Polymerized Hexamethyldisilazane Deposition

The properties of a polydimethylsiloxane (PDMS) surface were modified by a one-step deposition of plasma polymerized hexamethyldisilazane (pp-HMDS) by the arc discharge method. Scanning electron microscopy, atomic force microscopy, and Fourier-transform infrared spectroscopy analytical techniques were employed for morphological, structural, and chemical characterization of the pp-HMDS modified PDMS surface. The changes in PDMS substrate wetting properties were evaluated by means of contact angle measurements. The unmodified PDMS surface is hydrophobic with a contact angle of 122&deg;, while, after pp-HMDS film deposition, a dual-scale roughness PDMS surface with contact angle values as high as 170&deg; was obtained. It was found that the value of the contact angle depends on the plasma processing time. Chemically, the pp-HMDS presents methyl moieties, rendering it hydrophobic and making it an attractive material for creating a superhydrophobic surface, and eliminating the need for complex chemical routes. The presented approach may open up new avenues in design and fabrication of superhydrophobic and flexible organosilicon materials with a self-cleaning function

Properties of UV-Curable Hyperbranched Urethane-Acrylate Modified Acrylic Monomer Coatings

In this work it is suggested to modify trimethylolpropane ethoxylate triacrylate (TMPETA) with solvent born difunctional urethane acrylate oligomer (UA) of hyperbranched structure and high molecular weight. In this case the photopolymer composition initial UV-precuring was replaced by thermal action. Under heating at 70&nbsp;&deg;C temperature solvent (butyl acetate) evaporates and layer with proper deformation properties for microrelief embossing was obtained. After microrelief embossing UV-curing of photopolymer follows and photoinitiator initiated radical photopolymerization of TMPETA monomer and UA oligomer proceeds. The goal of this work - to investigate the influence of the acrylic composition on the UV-cured coating mechanical properties and on the geometrical parameters and optical properties of replicated microrelief. It was defined that coatings with UA oligomer possess higher deformation and mechanical properties due to the increase in layer flexibility. The replicated microrelief of geometrical parameters and diffraction efficiency close to those of master matrix to be used was obtained using compositions containing&nbsp; 30&nbsp;wt.&nbsp;%&nbsp;-&nbsp;40&nbsp;wt.&nbsp;% of&nbsp; UA.http://dx.doi.org/10.5755/j01.ms.17.4.772</p

Low-weight Impact Behaviour of Carbon Fibre Reinforced Methyl Methacrylate Nanocomposites

Inthis study, the carbon fibre reinforced methyl methacrylate (CF/MMA) compositetoecap for safety shoes was manufactured to increase the energy absorptioncapacity during impact. Different types of nanofillers such as organic andinorganic nanotubes, unmodified and organically modified nanoclays were appliedto modify matrix impact properties. The drop-weight impact tests of thenanocomposite toecap were performed with respect to nanofiller nature andcarbon fibre stacking sequence. It was found that the most influence on thestiffness and impact damage of the carbon fibre methyl methacrylatenanocomposite toecaps besides stacking sequence show organic and inorganic nanotubesor unmodified nanoclay.DOI: http://dx.doi.org/10.5755/j01.ms.21.2.7075</p

Effect of graphene oxide and silver nanoparticles hybrid composite on P. aeruginosa strains with acquired resistance genes

Background: In the last decades, nosocomial infections caused by drug-resistant Pseudomonas aeruginosa became a common problem in healthcare facilities. Antibiotics are becoming less effective as new resistant strains appear. Therefore, the development of novel enhanced activity antibacterial agents becomes very significant. A combination of nanomaterials with different physical and chemical properties enables us to generate novel multi-functional derivatives. In this study, graphene oxide and polyvinylpyrrolidone-stabilized silver nanoparticles hybrid nanocomposite (GO-Ag HN) were synthesized. The relation between antibiotic resistance and GO-Ag HN potential toxicity to clinical P. aeruginosa strains, their antibiotic resistance, and molecular mechanisms were assessed. Methods: Chemical state, particle size distribution, and morphology of synthesized GO-Ag NH were investigated using spectroscopy and microscopy techniques (UV-Vis, FTIR, XPS, TEM, SEM, AFM). Broad-spectrum antibiotic resistance of P. aeruginosa strains was determined using E-test. Antibiotic resistance genes were identified using polymerase chain reaction (PCR). Results: In this study, the toxicity of the GO-Ag NH to the isolated clinical P. aeruginosa strains has been investigated. A high antibiotic resistance level (92%) was found among P. aeruginosa strains. The most prevalent antibiotic resistance gene among tested strains was the AMPC beta-lactamase gene (65.6%). UV-vis, FTIR, and XPS studies confirmed the formation of the silver nanoparticles on the GO nanosheets. The functionalization process occurred through the interaction between Ag nanoparticles, GO, and polyvinylpyrrolidone used for nanoparticle stabilization. SEM analysis revealed that GO nanosheets undergo partial fragmentation during hybrid nanocomposite preparation, which remarkably increases the number of sharp edges and their mediated cutting effect. TEM analysis showed that GO-Ag HN spherical Ag nanoparticles mainly 9– 12 nm in size were irregularly precipitated on the GO nanosheet surface. A higher density of Ag NPs was observed in the sheets’ wrinkles, corrugations, and sharp edges. This hybrid nanocomposite poses enhanced antibacterial activity against carbapenem-resistant P. aeruginosa strains through a possible synergy between toxicity mechanisms of GO nanosheets and Ag nanoparticles. With incubation time increasing up to 10 minutes, the survival of P. aeruginosa decreased significantly. Conclusion: A graphene oxide and silver nanoparticles hybrid composite has been shown to be a promising material to control nosocomial infections caused by bacteria strains resistant to most antibiotics