Purpose: This study focuses on determining the best possible structure of the orthosis made with FDM 3D printing technology. To produce the samples, a thermoplastic PLA material was selected that met the conditions of biodegradability, biocompatibility and non-toxicity. The samples produced were subjected to a tensile strength test and corrosion resistance. Design/methodology/approach: Studies based on FEM analysis were carried out using the advanced engineering software CAE - Inventor. The samples were designed in the CAD system, while the G-Code path was generated using the PrusaSlicer 2.5.0 program dedicated to the Prusa i3 MK3S+ printer, which was used to create the models. Surface morphology observations of PLA were carried out with a Zeiss SUPRA 35 scanning electron microscope (SEM). The static tensile test was performed on the Zwick/Roell z100 device based on the PN-EN ISO 527:1 standard. Electrochemical corrosion tests were carried out using the Autolab PGSTAT302N Multi BA potentiostat in Ringer solution at a temperature of 37ºC. Findings: The research allowed the appropriate structure of the orthosis made of PLA polymer material using 3D FDM printing technology. The static tensile test, SEM and corrosion tests confirmed the correct application of this material for the selected purpose. It was possible to determine that samples with holes of 10 mm had the highest strength properties. Due to the tensile tests, the average tensile strength of those samples was around 61 MPa. The corrosion parameters of PLA were determined using Tafel analysis. Research limitations/implications: The research methodology proposed in work can be used to study other biomedical materials. The results presented can be the basis for further tests in order to search for the best orthopaedic stabiliser. Originality/value: The innovative part of the article are three different versions of structures intended for making orthoses used in medicine.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Podwyższone stężenia wielu zanieczyszczeń powietrza, zarówno w środowisku zewnętrznym, jak i wewnętrznym, notowane są w wielu krajach i przyczyniają się m.in. do podwyższonej zachorowalności na choroby układu oddechowego oraz krążenia, a nawet zwiększonej śmiertelności wywołanej przez nie bezpośrednio, jak i pośrednio. Z kolei depozycja (osiadanie) zanieczyszczeń powietrza na powierzchniach naturalnych i sztucznych przyczynia się do szkód w środowisku przyrodniczym, jak również w materiałach wytworzonych przez człowieka. Dotyczy to również urządzeń wentylacyjnych, których prawidłowe funkcjonowanie może również wpływać z kolei na zdrowie i jakość powietrza wewnątrz budynków. Podwyższone stężenia zanieczyszczeń powietrza mogą przyczyniać się do strat ekonomicznych. W przypadku wpływu na zdrowie związane są one przede wszystkim z kosztami nieobecności w pracy, kosztami leczenia czy przedwczesnym zgonem. Obniżenie plonowania roślin uprawnych i ozdobnych lub przyrostu biomasy drzewa mogą być kolejnym czynnikiem przyczyniającym się do strat ekonomicznych poza szkodnikami, patogenami czy ekstremalnymi zjawiskami przyrodniczymi. Uszkodzenia i degradacja urządzeń konstrukcyjnych, wentylacyjnych i innych materiałów przyczynia się natomiast do zwiększenia kosztów ich utrzymania.
EN
Higher concentrations of many air pollutants, both in the outdoor and indoor environments, are recorded in many countries and contribute, among the others, to increased incidence of respiratory and cardiovascular diseases and even increased mortality caused by them directly as well as indirectly. In addition, deposition of air pollutants on natural and artificial surfaces contributes to damage to the natural environment, as well as to man-made materials. This is also valid for ventilation systems, which proper functioning might be also affected on indoor air quality and human health. Elevated air pollution concentrations might also cause economic losses. In the case of health impacts, they are primarily related to the cost of absence from work, medical costs, or premature death. Reduced crop yields or tree biomass growth can be another factor contributing to economic losses in addition to pests, pathogens or weather extremes. The damage of construction materials, ventilation system and other materials might also cause an increase in the cost of their maintenance.
The solar radiation absorbed by photovoltaic panels is not fully utilized in the production of electricity. When the photovoltaic panels are exposed to solar radiation, part of the energy of the incident radiation is transformed into heat accumulated inside these panels. The heat accumulated inside the photovoltaic panels causes two types of losses. The first type of losses is the increase in the operating temperature of the panels and the deterioration of their efficiency and life span. The second type of losses explains that part of the energy of the incident radiation is transformed into heat inside the panels and does not contribute to the production of electrical energy. There are several cooling systems that have been applied to photovoltaic panels for the purpose of regulating their temperature including air, water, and nanofluid cooling systems, which are mostly done by placing a solar collector in the back side of the photovoltaic panels (PV/T). There is also a recently used system that uses phase change material (PCM) in cooling. This paper provides a comprehensive review of several cooling methods and their improvements that researchers have focused on. Through this review, it is clear that the best improvement in the performance of the photovoltaic panel occurs when using PCM because of the high heat transfer coefficient of these materials. Performance improves more when the addition of nanoparticles to the phase change material (PCM-Np) and also when merging (PCM) with (PV/T).
Nowadays, additive manufacturing (AM) has surpassed traditional machining in the realm of emerging manufacturing. In the case of conventional machining, where the material is removed by different processes (subtractive manufacturing), there is a possibility of warping and internal stress development. Rapid prototyping is another option to avoid all the drawbacks of conventional machining in terms of manufacturing cost, time, accuracy, and quality. Rapid prototyping of a product by adding material (additive manufacturing) is gaining commercial traction. Additive manufacturing is frequently employed for the fabrication and bulk customization of all kinds of intricate geometrical designs those are absurd by traditional manufacturing techniques. Additive manufacturing techniques are broadly divided into four categories: (a) material extrusion, (b) chain polymerization, (c) laser or electron beam assisted sintering, and (d) direct writing-based processes. This article is a cutting-edge review that focuses on additive manufacturing processes and materials used in additive manufacturing. The process parameters for experimentation are chosen based on the application for which the part is designed. Some input process factors influence others for a specific response, and these critical process parameters are identified and optimized. This paper also gives a synopsis of failures associated with some additive manufacturing methods and their preventive actions.
Purpose: The issue of shaping the attitude of employee involvement in an organisation is a relatively new area of scientific interest. Shaping employees' attitudes, understood as a conscious influence to consolidate or change them so that they are conducive to the safe operation of building objects, should be of significant importance for any organisation. Attitude is related to behaviour, the most elementary form of human activity, which is externally observable. Design/methodology/approach: Statistical analysis. Findings: The issue of shaping organisational attitudes and behaviours is related to the need to consider the factors that trigger the change process. It is important to diagnose whether the engine of change is the person with a specific attitude or elements from his environment. Research limitations/implications: The article presents a theoretical introduction and the results of diagnostic tests. It proposes actions shaping the attitudes and behaviour of employees regarding the safe operation of buildings, based on the example of the University of Agribusiness in Lomza. Practical implications: The classical approach to the safety of buildings focuses primarily on the technical and engineering side of the building. Planners, designers, contractors, and users of buildings strive to make them the least hazardous to health and life, especially during the operation of the building. At the same time, it is important to bear in mind that safe operation is influenced by the behaviour of facility users, as they are the weakest link in management. Consequently, this is where the reserves for raising the health and safety of building users to a higher level still lie. Originality/value: One of the main factors significantly influencing how an individual will behave when placed in a risky situation is how they perceive the risks involved. People's beliefs about various things can influence their behaviour more strongly than objective reality. To activate the reserves hidden in human behaviour to improve the safety level of buildings, it is necessary to fully recognise the causes and mechanisms that lead users to risky actions. Those behaviours allow the application of appropriate training and supervision methods, and more broadly of management methods, which would induce users to behave safely and to react consciously, directly or indirectly, to emerging risks during the operation of the works.
8
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
Artykuł jest kontynuacją cyklu o materiałach stosowanych do wtórnej hydroizolacji budynków. Tym razem autor skupia uwagę na mineralnych zaprawach uszczelniających. Dokładnie opisuje możliwości ich zastosowania, właściwości, a także sposób aplikacji.
EN
The article is a continuation of the series on materials used for secondary waterproofing of buildings. This time, the author focuses on mineral sealing mortars and accurately describes the possibilities of their use, properties, and the method of application.
Polymeric materials and their composites in vehicles have experienced a real boom in the last 30 years, and their application is increasing with a tendency to further growth. The demands on the modern vehicle industry, whether they are trains, planes, or cars, are ever challenging - users want high-performance vehicles, but at the same time they are looking for improved reliability and safety, greater comfort, and low pricing. Changing the proportion of light-weight materials to steel in the construction of new vehicles helps make them lighter and more fuel or electrical energy efficient, resulting in lower greenhouse gas emissions. There is one family of materials that is responding to the challenge of these potentially conflicting demands: polymer materials. This includes relatively pure chemical materials as well as fibre-filled polymer composites.65 This article presents polymeric materials that are used for the production of vehicle parts today.
In this work, an attempt was made to apply laser surface technology for enhancement of the properties and strengthening the material with addition of ceramic phases in the form of silicon and tungsten carbide particles, leading to a remarkable increase in hardness. Thanks to rapid cooling caused by heat being transferred to the cold substrate, an advantageous, fine-grained structure develops, showing higher gradient morphology; furthermore, the surface layers obtained with laser alloying offer greater heat-resistance and anti-corrosion properties, as well as high wear resistance in addition to the aforementioned hardness, which increases by as much as 15% for the AlSi9Cu4 alloy compared with the alloy after standard heat treatment. Such an increase in the values of the mechanical properties makes it possible to use the investigated alloy in applications including, e.g., recyclable thermally exposed surfaces, such as pistons in internal combustion engines, which enables further decrease in the weight and the thermal expansion with simultaneous increase in the strength, reduction in fuel consumption, and increase in carrying load, speed, and range, which generates the need for further research into the area.
This article analyzes the planning features of small school spaces in different regions of Ukraine between the XIX - XX centuries. The main constructive decisions of typical residential architecture which manifested itself in school construction are identified. On the example of Ukraine, we trace a large number of stylistic and planning borrowings from typical residential architecture of the folk artists and architects from different regions, which manifested itself in rural school construction.
Celem artykułu było przedstawienie rozwoju dwóch szeroko stosowanych technik drukowania – fleksografii i wklęsłodruku, nazywanego też rotograwiurą. Opisano stadia rozwoju obu tych technik. Omówiono cechy charakterystyczne każdej z nich, przede wszystkim pod kątem jakości otrzymanych nadruków. Scharakteryzowano również farby drukowe stosowane w każdej z omawianych technik.
EN
The aim of this article was the demonstration of two important printing techniques – flexography and rotogravure. The development steps of both techniques are described. The properties characteristic for each of them are discussed, especially from the print quality point of view. The printing inks used in these techniques are characterized.
The Ir radiation System for High-Temperature Reactors (ISHTAR) thermostatic rig will be used to irradiate advanced core material samples in conditions corresponding to those prevailing in the high-temperature reactors (HTRs): these conditions include a stable temperature extending up to 1000°C in the helium atmosphere. Computational and experimental studies concerning the design have been conducted, proving the possibility of these conditions’ fulfi llment inside the rig while maintaining the safety limits for MARIA research reactor. The outcome is the thermostatic rig design that will be implemented in the MARIA reactor. Appropriate irradiation temperature will be achieved by a combination of electric heating with the control system, gamma heating, and a helium insulation gap with precisely designed thickness. The ISHTAR rig will be placed inside the vertical irradiation channel, which is located in the reactor pool. The device is being developed from scratch at the Nuclear Facilities Operation Department of the National Centre for Nuclear Research as a part of the GOSPOSTRATEG programme
14
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
W artykule przybliżono definicję tarasu wentylowanego, a także na przykładzie omówiono specyfikę i montaż tarasu na gruncie. Wymieniono etapy wykonywania robót oraz kryteria doboru odpowiednich materiałów.
EN
The paper gives a definition of a ventilated terrace and also discusses the specifics and installation of a terrace on the ground using an example. The stages of the work and the criteria for selecting appropriate materials are listed.
15
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
W artykule opisano poprawne wykonanie tarasu wentylowanego krok po kroku. Podkreślono również wagę warstwy hydroizolacyjnej i właściwego doboru materiałów.
EN
The article describes the correct execution of a ventilated terrace – step by step. The importance of the waterproofing layer and the correct selection of materials were also emphasized.