rss_2.0Materials Sciences FeedSciendo RSS Feed for Materials Scienceshttps://www.sciendo.com/subject/MShttps://www.sciendo.comMaterials Sciences Feedhttps://www.sciendo.com/subjectImages/Material_Sciences.jpg700700International Symposium "Technical Textiles - Present and Future"https://sciendo.com/book/9788366675735<DIV align=justify> <P>The „Technical Textiles-Present and Future” International Symposium is a scientific event that has become traditional in the field of textiles, since 2009, being organized by the Department of Engineering and Design of Textile Products within the Faculty of Industrial Design and Business Management from Gheorghe Asachi Technical University of Iasi, Romania. </P> <P>Over the years and from one edition to another, the symposium brought together leading researchers, textile experts from the industry, teachers from academia and vocational education, PhD students, and relevant stakeholders from the national and international scientific area to share their knowledge and the good practices regarding technical textiles. </P> <P>Reaching the seventh edition now, the TTPF symposium has become a scientific forum in the field of technical textiles, supporting the cross-disciplinary research fields, providing the participants a real opportunity for ideas exchanging, to present the latest achievements, and to discuss perspectives. </P> <P>With the focus on the latest scientific advances in technical textiles but also on the companies’ needs for innovative solutions, a new topic concerning environmental and sustainability issues for the technical textiles field was introduced for TTPF 2021, a topic which we hope will stir the interest of all participants. </P> <P>For the 7th TTPF International Symposium, the topics are: Technical Textiles for Agrotech, Buildtech, and Geotech Applications; Technical Textiles for Clothtech and Hometech Applications; Technical Textiles for Indutech and Mobiltech Applications; Functional and Smart Textiles for Medtech, Protech, and Sportech Applications; Technical Textiles for Oekotech and Packtech Applications; Technical Textiles and Sustainability; Textile Education and Training for the Technical Textiles Field; The „Technical Textiles-Present and Future” International Symposium is a scientific event that has become traditional in the field of textiles, since 2009, being organized by the Department of Engineering and Design of Textile Products within the Faculty of Industrial Design and Business Management from Gheorghe Asachi Technical University of Iasi, Romania. </P> <P>Over the years and from one edition to another, the symposium brought together leading researchers, textile experts from the industry, teachers from academia and vocational education, PhD students, and relevant stakeholders from the national and international scientific area to share their knowledge and the good practices regarding the technical textiles. </P> <P>Reaching the seventh edition now, the TTPF symposium has become a scientific forum in the field of technical textiles, supporting the cross-disciplinary research fields, providing the participants a real opportunity for ideas exchanging, to present the latest achievements, and to discuss perspectives. </P> <P>With the focus on the latest scientific advances in technical textiles but also on the companies’ needs for innovative solutions, a new topic concerning environmental and sustainability issues for the technical textiles field was introduced for TTPF 2021, a topic which we hope will stir the interest of all participants. </P> <P>For the 7th TTPF  International Symposium, the topics are: Technical Textiles for Agrotech, Buildtech, and Geotech Applications; Technical Textiles for Clothtech and Hometech Applications; Technical Textiles for Indutech and Mobiltech Applications; Functional and Smart Textiles for Medtech, Protech, and Sportech Applications; Technical Textiles for Oekotech and Packtech Applications; Technical Textiles and Sustainability; Textile Education and Training for the Technical Textiles Field; Management and Entrepreneurship. </P></DIV>BOOKResearch Flights on Blue Origin's New Shepardhttps://sciendo.com/article/10.2478/gsr-2021-0005<abstract> <title style='display:none'>Abstract</title> <p>Blue Origin's New Shepard launch vehicle made its first flight above the Kármán Line, returning safely to Earth in November 2015. At the time when this paper is being written (February 2021), the system has conducted 14 flights, including 10 with research and education payloads aboard. More than 100 payloads have exercised a wide range of capabilities and interfaces, from small cubesat-form factor student payloads to large custom payloads of nearly 100 kg. Investigations have spanned a wide range of high-altitude and microgravity research objectives, as well as raising technology readiness level (TRL) on diverse hardware. This paper summarizes New Shepard's payload missions to date, and presents standardized and custom accommodations, both in the shirtsleeve cabin and directly exposed to the space environment.</p> </abstract>ARTICLE2021-03-20T00:00:00.000+00:00Using Tapered Channels to Improve LAD Performance for Cryogenic Fluids: Suborbital Testing Resultshttps://sciendo.com/article/10.2478/gsr-2021-0009<abstract> <title style='display:none'>Abstract</title> <p>Improvement of cryogenic fluid storage and transfer technology for in-space propulsion and storage systems is required for long-term space missions. Screened channel liquid acquisition devices (LADs) have long been used with storable propellants to deliver vapor-free liquid during engine restart and liquid transfer processes. The use of LADs with cryogenic fluids is problematic due to low temperatures associated with cryogenic fluids. External heat leaks will cause vapor bubbles to form within the LADs that are difficult to remove in the existing designs. A tapered LAD channel has been proposed to reliably remove vapor bubbles within the device without costly thrusting maneuvers or active separation systems. A model has been developed to predict bubble movement within tapered LAD channels, and subsequent ground testing was completed with a simulant fluid to provide model validation data. Suborbital microgravity testing of tapered LAD technology was recently completed with two different simulant fluids and demonstrated that the concept can passively expel vapor bubbles within the channel. Two additional suborbital flights have been funded to further develop this technology by investigating the performance of larger scale versions of the design.</p> </abstract>ARTICLE2021-06-26T00:00:00.000+00:00Shared Metabolic Remodeling Processes Characterize the Transcriptome of within Various Suborbital Flight Environmentshttps://sciendo.com/article/10.2478/gsr-2021-0002<abstract> <title style='display:none'>Abstract</title> <p>The increasing availability of flights on suborbital rockets creates new avenues for the study of spaceflight effects on biological systems, particularly of the transitions between hypergravity and microgravity. This paper presents an initial comparison of the responses of Arabidopsis thaliana to suborbital and atmospheric parabolic flights as an important step toward characterizing these emerging suborbital platforms and their effects on biology. Transcriptomic profiling of the response of the Arabidopsis ecotype Wassilewskija (WS) to the aggregate suborbital spaceflight experiences in Blue Origin New Shepard and Virgin Galactic SpaceShipTwo revealed that the transcriptomic load induced by flight differed between the two flights, yet was biologically related to traditional parabolic flight responses. The sku5 skewing mutant and 14-3-3κ:GFP regulatory protein overexpression lines, flown in the Blue Origin and parabolic flights, respectively, each showed altered intra-platform responses compared to WS. An additional parabolic flight using the F-104 Starfighter showed that the response of 14-3-3κ:GFP to flight was modulated in a similar manner to the WS line. Despite the differing genotypes, experimental workflows, flight profiles, and platforms, differential gene expression linked to remodeling of central metabolic processes was commonly observed in the flight responses. However, the timing and directionality of differentially expressed genes involved in the conserved processes differed among the platforms. The processes included carbon and nitrogen metabolism, branched-chain amino acid degradation, and hypoxic responses. The data presented herein highlight the potential for various suborbital platforms to contribute insights into biological responses to spaceflight, and further suggest that in-flight fixation during suborbital experiments will enhance insights into responses during each phase of flight.</p> </abstract>ARTICLE2021-01-29T00:00:00.000+00:00A Rapid Fabrication Methodology for Payload Modules, Piloted for the Observation of Queen Honey Bees () in Microgravityhttps://sciendo.com/article/10.2478/gsr-2021-0008<abstract> <title style='display:none'>Abstract</title> <p>Microgravity experiment modules for living organisms have been instrumental to space research, yet their design remains complex and costly. As the private space sector enables more widely available payloads for researchers, it is increasingly necessary to design experimental modules innovatively so that they are proportionately accessible. To ease this bottleneck, we developed a rapid fabrication methodology for producing custom modules compatible with commercial payload slots. Our method creates a unified housing geometry, based on a given component layout, which is fabricated in a digital design and subtractive manufacturing process from a single lightweight foam material. This module design demonstrated a 25–50% reduction in chassis weight compared with existing models, and is extremely competitive in manufacturing time, simplicity, and cost. To demonstrate the ability to capture data on previously limited areas of space biology, we apply this methodology to create an autonomous, video-enabled module for sensing and observing queen and retinue bees aboard the Blue Origin New Shepard 11 (NS-11) suborbital flight. To explore whether spaceflight impacts queen fitness, results used high-definition visual data enabled by the module's compact build to analyze queen-worker regulation under microgravity stress (n = 2, with controls). Overall, this generalizable method for constructing experimental modules provides wider accessibility to space research and new data on honey bee behavior in microgravity.</p> </abstract>ARTICLE2021-06-01T00:00:00.000+00:00Pioneering the Approach to Understand a Trash-to-Gas Experiment in a Microgravity Environmenthttps://sciendo.com/article/10.2478/gsr-2021-0006<abstract> <title style='display:none'>Abstract</title> <p>The Orbital Syngas/Commodity Augmentation Reactor (OSCAR) project investigated hardware and engineering development for waste conversion operations related to trash deconstruction and repurposing for long duration space missions. Operations of the trash-to-gas system were investigated to compare microgravity (μg) and Earth gravity environments. The OSCAR system has been demonstrated in other μg platforms, but here the performance and results on the Blue Origin New Shepard Suborbital Vehicle are discussed. The OSCAR suborbital operation demonstrated the introduction of trash into a high temperature reactor for solid to gas conversion, ignition of mixed trash feedstock, combustion during μg, and subsequent gas collection processes in a flight automated sequence. An oxygen (O<sub>2</sub>)- and steam-rich environment was created within the reactor for ignition conditions, and the product gases were quantified to verify the reaction product composition. This paper focuses on the chemistry processes of the reactor, and gas and solid product analysis of the μg and gravity conditions. The gas production, reactor thermal profile, and mass and carbon conversion results validated confidence in the system design to continue the advancement of this technology for future spaceflight implementations.</p> </abstract>ARTICLE2021-05-24T00:00:00.000+00:00The Impact of Hindlimb Suspension on the Rat Eye: A Molecular and Histological Analysis of the Retinahttps://sciendo.com/article/10.2478/gsr-2021-0007<abstract> <title style='display:none'>Abstract</title> <p>The Spaceflight Associated Neuro-ocular Syndrome (SANS) is hypothesized to be associated with microgravity-induced fluid shifts. There is a need for an animal model of SANS to investigate its pathophysiology. We used the rat hindlimb suspension (HS) model to examine the relationship between the assumed cephalad fluid shifts, intraocular (IOP) pressure and the molecular responses in the retina to the prolonged change in body posture. Long evans rats were subjected to HS up to 90 days. Animals completing 90-day suspension were further studied for recovery periods up to 90 additional days in normal posture. With respect to baseline, the average IOP increase in HS animals and the rate of change varied by cohort. Transcriptomics evidence supported a response to HS in the rat retina that was affected by age and sex. Several molecular networks suggested stress imposed by HS affected the retinal vasculature, oxidative and inflammation status, pigmented epithelium and glia. The CSNK1A1-TP53 pathway was implicated in the response in all cohorts. Sex-specific genes were involved in cytoprotection and may explain sex-dependent vulnerabilities to certain eye diseases. These results support the hypothesis that changes in the biology of the retina subjected to simulated microgravity involve both the neural and vascular retina.</p> </abstract>ARTICLE2021-09-18T00:00:00.000+00:00Space Flight Cultivation for Radish () in the Advanced Plant Habitathttps://sciendo.com/article/10.2478/gsr-2021-0010<abstract> <title style='display:none'>Abstract</title> <p>In preparation of a flight experiment, ground-based studies for optimizing the growth of radishes (Raphanus sativus) were conducted at the ground-based Advanced Plant Habitat (APH) unit at the Kennedy Space Center (KSC), Florida. The APH provides a large, environmentally controlled chamber that has been used to grow various plants, such as Arabidopsis, wheat, peppers, and now radish. In support of National Aeronautics and Space Administration (NASA)'s goals to provide astronauts with fresh vegetables and fruits in a confined space, it is important to extend the cultivation period to produce substantial biomass. We selected Raphanus sativus cv. Cherry Belle as test variety both for preliminary tests and flight experiments because it provides edible biomass in as few as four weeks, has desirable secondary metabolites (glucosinolates), is rich in minerals, and requires relatively little space. We report our strategies to optimize the growth substrate, watering regimen, light settings, and planting design that produces good-sized radishes, minimizes competition, and allows for easy harvesting. This information will be applicable for growth optimization of other crop plants that will be grown in the APH or other future plant growth facilities.</p> </abstract>ARTICLE2021-08-23T00:00:00.000+00:00APL JANUS System Progress on Commercial Suborbital Launch Vehicles: Moving the Laboratory Environment to Near Spacehttps://sciendo.com/article/10.2478/gsr-2021-0003<abstract> <title style='display:none'>Abstract</title> <p>Multiple private companies are building suborbital reusable launch vehicles possessing vastly different designs. Many of these companies originally focused on space tourism; however, revolutionary applications for scientific and engineering research as well as technology demonstrations and instrument development are emerging. The dramatic reduction in cost over traditional launch systems as well as a guaranteed (and rapid) safe payload return enable many new launch vehicle applications. These new capabilities will essentially move the laboratory environment up to the edge of space. To make use of these novel launch vehicles, the John Hopkins University Applied Physics Laboratory has established a Commercial Suborbital Program with a core system (JANUS) to support and enable many future suborbital missions. This program has already conducted six suborbital flight missions to establish vehicle interfaces and analyze the suitability and limits of each flight environment. Additionally, this program has also been selected by the NASA Flight Opportunities Program for five additional operational suborbital missions. Here we present the results of our completed missions as well as descriptions of future selected missions scheduled for 2021–2023.</p> </abstract>ARTICLE2021-01-29T00:00:00.000+00:00The Adhesive Response of Regolith to Low-Energy Disturbances in Microgravityhttps://sciendo.com/article/10.2478/gsr-2021-0001<abstract> <title style='display:none'>Abstract</title> <p>Small, airless bodies are covered by a layer of regolith composed of particles ranging from μm-size dust to cm-size pebbles that evolve under conditions very different than those on Earth. Flight-based microgravity experiments investigating low-velocity collisions of cm-size projectiles into regolith have revealed that certain impact events result in a mass transfer from the target regolith onto the surface of the projectile. The key parameters that produce these events need to be characterized to understand the mechanical behavior of granular media, which is composed of the surfaces of small bodies. We carried out flight and ground-based research campaigns designed to investigate these mass transfer events. The goals of our experimental campaigns were (1) to identify projectile energy thresholds that influence mass transfer outcomes in low-energy collision events between cm-size projectiles and μm-size regolith, (2) to determine whether these mass transfer events required a microgravity environment to be observed, and (3) to determine whether the rebound portion of these collision events could be replicated in a laboratory drop tower environment. We found that (1) mass transfer events occurred for projectile rebound accelerations &lt;7.8 m/s<sup>2</sup> and we were unable to identify a corresponding impact velocity threshold, (2) mass transfer events require a microgravity environment, and (3) ourdrop tower experiments were able to produce mass transfer events. However, drop tower experiments do not exactly reproduce the free-particle impacts and rebound of the long-duration microgravity experiments and yielded systematically lower amounts of the overall mass transferred.</p> </abstract>ARTICLE2021-01-29T00:00:00.000+00:00Liquid Propellant Mass Measurement in Microgravityhttps://sciendo.com/article/10.2478/gsr-2021-0004<abstract> <title style='display:none'>Abstract</title> <p>The Modal Propellant Gauging (MPG) experiment has demonstrated sub-1% gauging accuracy under laboratory conditions on both flight hardware and subscale tanks. Recently, MPG was adapted for flight on Blue Origin's New Shepard vehicle and has flown twice, achieving equilibrated, zero-g surface configurations of propellant simulant at three different fill fractions. Flight data from MPG missions on New Shepard P7 and P9 show agreement between known and measured propellant levels of 0.3% for the fill fractions investigated in the present study. Two approaches for estimating zero-g propellant mass are described here. Both approaches rely on measuring shifts in modal frequencies of a tank excited by acoustic surface waves and subject to fluid mass loading by the propellant. In the first approach, shifts in the lowest mode frequency (LMF) are measured and associated with liquid fill-level changes. In the second approach, 1-g modal spectra at a range of known fill levels are used in a cross-correlation calculation to predict fill levels associated with a zero-g modal spectrum. Flight data for both approaches are consistent with finite element predictions using a simple fluid–structure interaction model. In both settled and unsettled microgravity environments, MPG meets or exceeds NASA Roadmap goals for in-space propellant mass gauging.</p> </abstract>ARTICLE2021-02-26T00:00:00.000+00:00Utilizing technology to enhance compliance and oral health.https://sciendo.com/article/10.2478/asmj-2021-0001ARTICLE2021-06-12T00:00:00.000+00:00Efficiency of different instruments used for composite filling polishing.https://sciendo.com/article/10.2478/asmj-2021-0005<abstract> <title style='display:none'>Abstract</title> <p>Introduction: Improper finishing and polishing of fillings leads to surface roughness of the restoration which leads to excessive plaque accumulation, gingival irritation, increased surface staining and poor aesthetics of restored teeth. Therefore, it is essential to use polishing instruments and pastes as a final step of simple caries treatment in order to achieve optimal long-time results. The aim of this study is to evaluate the efficiency of 4 different finishing and polishing instruments used for surface smoothening of aesthetic restorative materials in vitro. Materials and methods: 40 composite (Reality X) samples were prepared in vitro. Their surface irregularities were measured along 3 diagonals before and after polishing. Sof-Lex discs (3M Espe), rubber cones (Kenda), Arkansas stone (Fino) and polishing paste and a professional toothbrush (Kerr) were used for polishing. Each sample was polished under 5N pressure for 30 seconds at 3000 rpm. The surface roughness was than measured using a profilometer. Statistic analysis was performed using ANOVA and unpaired T-tests, the significance level was set at a value of p&lt;0.05. Results: Based on the mean values, the smallest roughness was found in the control group- 0.11, while the highest in the rubber polishers and Arkansas stone group- 0.47 and 0.48. The values for the Sof-Lex disc group and the polishing paste-toothbrush group were 0.40 and 0.39. Statistical analysis showed no significant differences between the four groups. Conclusion: It is mandatory to use polishing tools in order to obtain a smooth surface of the restoration and avoid the unwanted long-term complications. Polishing using brush and abrasive paste produced the smoothest surface of the composite.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00The assessment of two-way relationship between periodontal diseases and diabetes mellitus.https://sciendo.com/article/10.2478/asmj-2021-0003<abstract> <title style='display:none'>Abstract</title> <p>Periodontal disease and diabetes mellitus have been said to have a two-way relationship, with diabetes leading to oral disease and periodontitis exacerbating hyperglycemia. The universal biologic mechanisms and demographic and behavioral risk drivers, underlying these associations in both directions, are also described.</p> <p>Both the diseases are chronic and they are affecting large population worldwide. Periodontitis is also recognized as the sixth major complication of diabetes, while diabetes mellitus is a metabolic disorder which has an impact on the global health and plays a crucial role in the pathogenesis of periodontitis.</p> <p>The aim of this article is to illustrate a systematic and comprehensive analysis of the literature, on the mutual relationship between diabetes mellitus and periodontal diseases, trying to identify if the prevalence of periodontitis is higher in diabetics or if the incidence of diabetes is greater in patients with periodontal disease. Moreover, our intention is to increase the level of awareness of diabetologists and dentists about the interaction between this two pathologies.</p> <p>Oral and periodontal health should be promoted as integral components of diabetes management. Dental professionals can detect unrecognized potential dysglycemia and refer for medical examination. Furthermore, the control of periodontal disease may enhance glycemic control which contributes to a better control of periodontal disease.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Fear and dental anxiety in children: a study of the contributing factors.https://sciendo.com/article/10.2478/asmj-2021-0006<abstract> <title style='display:none'>Abstract</title> <p>Introduction: Dental fear and anxiety are an important issue affecting children’s oral health and clinical management, and also an insufficiently studied subject in dentistry.</p> <p>Aim of the study: The aim of this study was to better understand the child patient - dentist versus dentist - child patient relationship and study the dental fear and anxiety of children in order to improve the dental office practice. Material and methods: In this study a personalized questionnaire was created and applied on a number of 333 children, in 4 schools from Mures county, Romania, on girls and boys between the ages of 8 and 13. The questionnaires used emoticons alongside words in order to better determine the state of anxiety created by the dental appointment and everything that it entails. All data and results obtained were analyzed using Excel and Graph Pad Prism 5.0 software.</p> <p>Results: Out of 333 patients, 133 subjects (40%) were 8-10-year-old, 143 subjects (42.9%) 11 - 13 years and 57 subjects (17.1%) were over 14 years. 175 girls (52.6%) and 158 boys (47.4%) demonstrated their courage and desire in participating in our study. It was determined that fear of dental appointments was caused in children over 14 years of age. The state of relaxation is generally enjoyed by urban children (45%) and those aged 11-13 years (37.1%); the percentage of boys in this category is an interesting aspect (40.5%).</p> <p>Conclusion: Dental anxiety is multifactorial and is far more complex than can be explained by a single contributing factor. The direct involvement of the child from the perspective of maintaining dental health, leads to the elimination of the state of fear and anxiety. Regular visits to the dental office, on the initiative of the child patient itself can reduce the anguish.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Contribution to the study of improving the aesthetics of the smile by repairing and reshaping the incisors with composite materials.https://sciendo.com/article/10.2478/asmj-2021-0004<abstract> <title style='display:none'>Abstract</title> <p>Introduction. Dental aesthetics, although it seems something relative and difficult to evaluate, it is governed by a series of laws and rules that connect the dental disciplines, creating a unitary whole. It is structured by rules, perfected by artistic sense and by the inclination towards beauty of all specialists in dento-facial cosmetics.</p> <p>The aim of the study is to highlight an overview of aesthetic factors to consider when restoring anterior teeth with direct composite materials.</p> <p>Material and methods. A total of 25 patients were included in the study where the anterior teeth were restored using Gradia Direct Anterior (from GC) and Filtek Z550 (from3M-ESPE) composite kits, in perfect isolation using rubber damn, with a separate appointment after 24 hours for the polishing step, for which Rainbow Kit Technic and polishing Platina Hi-Gloss (from Prevest) paste were used. While the replacement of the tooth defect, we ensured that the composite increment, which we used should not be more than 2mm in thickness, and light cured for 20 seconds as the producer recommends. In none of all tooth shape modification (elongation in incisal zone) we did not modify the occlusion, by eliminating all premature contacts. All patients included in the study have signed the informed consent and agreed to participate in this research.</p> <p>Results. From a total of 25 patients, we repaired 20 central incisors with the mesial (18 cases) or distal (2 cases) angles fractured, in different accidents, 5 cases with diastema by small shape of the crown or malposition of one of the central incisors.</p> <p>Conclusions. Restoring the incisal angle or the incisal edge and refining a natural and improved smile of the patient is e very frequent dental intervention, especially nowadays when aesthetics plays an important role in the social society.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Compendium of current ceramic materials used for the CAD/CAM dentistry.https://sciendo.com/article/10.2478/asmj-2021-0002<abstract> <title style='display:none'>Abstract</title> <p>Nowadays, patients require the highest quality of treatment, but generally prefer to spend as little time as possible in the dental chair. Therefore, there is significant benefit for using new technologies such as CAD/CAM (computer aided design/computer aided manufacturing), which provides both quality and speed. There is an increase in ceramic materials and ceramic blocks/discs available, with varying properties. This has resulted in some confusion and difficulty in making an informed decision about which material is best for a specific clinical situation. The objective of this review is to provide an overview and comparison of basic mechanical properties of currently used CAD/CAM ceramic materials based on a review of the currently available literature.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Improved rack and pinion drivehttps://sciendo.com/article/10.37705/TechTrans/e2021013<abstract> <title style='display:none'>Abstract</title> <p>A typical rack and pinion drive set is comprised of a rack and a pinion. There is an inter-tooth clearance between the mating teeth of the rack and the pinion, which has advantages and disadvantages. The disadvantage of this clearance is the errors that occur in the positioning of the machine tool during set-up. Elimination of clearance between teeth is possible by using a pinion drive with two pinions. This ensures continuous contact between the teeth, regardless of the direction of machine movement.</p> <p>These are found on new machines, while older machines do not have such a solution. This paper presents a solution with two pinions, which can be used in such older machines and which makes it possible to achieve qualitative parameters that were not possible before.</p> </abstract>ARTICLE2021-09-04T00:00:00.000+00:00Rzeszów as an example of a ‘new town’ tailored for the modern erahttps://sciendo.com/article/10.37705/TechTrans/e2021006<abstract> <title style='display:none'>Abstract</title> <p>The city life cycle is an issue that can be considered from many perspectives. Klaassen’s period cycle is the basic model of city life: urbanisation– suburbanisation–deurbanisation–reurbanisation. In each of these periods, cities develop by, building and transforming their structures. This article presents various approaches to shaping new urban spaces using the city of Rzeszów as an example. In the city’s history, three periods are distinguished during which structures referred to as the ‘new town’ were created in the 16<sup>th</sup> and 20<sup>th</sup> centuries and continue to be created now. After analysing the site-forming processes, the most important features of new-town urban systems are compared.</p> </abstract>ARTICLE2021-04-22T00:00:00.000+00:00The formation of zinc coatings in nanocrystallised zinc powdershttps://sciendo.com/article/10.37705/TechTrans/e2021009<abstract> <title style='display:none'>Abstract</title> <p>The kinetics of and mechanism for galvanising low-carbon steel (0.2% C) were examined in powder media which were pre-treated to obtain a fine nanostructured ZnO layer on the surface of zinc powder particles. The effective diffusion coefficient of Zn atoms through the ZnO shell was estimated to be in the order of 1·10<sup>−10</sup> m<sup>2</sup>·s<sup>−1</sup>. The contribution of the Zn-gas evaporation/condensation microprocesses, which could occur in relation to the above diffusion through a nanostructured surface layer, was evaluated with numerical calculations in the temperature range of 550–950 K and for an average particle size of ZnO up to 100 nm. Our results suggest that the outward diffusion of metallic zinc takes place from the core of powder microparticles across the nano-grain boundaries of their modified surface layer, and can be further intensified by the presence of other inter-phase defects, such as nano-porosity.</p> </abstract>ARTICLE2021-07-12T00:00:00.000+00:00en-us-1