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  • 1
    Online Resource
    Online Resource
    Multistage Optimization of Occupational Safety for Cotton Fabric Screen Printing Press Operators
    Informa UK Limited ; 2023
    In:  Journal of Natural Fibers Vol. 20, No. 1 ( 2023-04-24)
    Details
    In: Journal of Natural Fibers, Informa UK Limited, Vol. 20, No. 1 ( 2023-04-24)
    Type of Medium: Online Resource
    ISSN: 1544-0478 , 1544-046X
    URL: Article
    DOI: 10.1080/15440478.2023.2192543
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2023
    detail.hit.zdb_id: 2187542-X
    SSG: 23
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  • 2
    Online Resource
    Online Resource
    Estimation of Seams in Paraglider Wing
    Walter de Gruyter GmbH ; 2022
    In:  Autex Research Journal Vol. 22, No. 4 ( 2022-12-01), p. 383-390
    Details
    In: Autex Research Journal, Walter de Gruyter GmbH, Vol. 22, No. 4 ( 2022-12-01), p. 383-390
    Abstract: The aim of the article is to analyze the seams connecting the covering textiles in paraglider wing and estimate their physical strength. The most extreme flight parameters (the angle of attack and velocity) in the numerical model of the wing allow the determination of the mean pressure inside the contour and the maximal difference between the pressures on the inner and the outer material surfaces. The preprocessing stage and numerical calculations in Ansys environment consider three different covering materials. The tool Porous Media is used to create the objects of a given value of air permeability. The estimated parameter of seam is the maximal pressure difference between both sides of the covering material, which that interacts with the test results. The quality index of the seam is defined by the maximal force to seam rupture and relative elongation during rupture. The obtained results indicate that the seams are resistant to the pressure difference caused by the most extreme flight parameters.
    Type of Medium: Online Resource
    ISSN: 2300-0929
    URL: Article
    DOI: 10.2478/aut-2020-0054
    Language: English
    Publisher: Walter de Gruyter GmbH
    Publication Date: 2022
    detail.hit.zdb_id: 2646010-5
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  • 3
    Online Resource
    Online Resource
    Textile Cover Effect on Aerodynamic Characteristics of a Paraglider Wing
    Walter de Gruyter GmbH ; 2019
    In:  Fibres and Textiles in Eastern Europe Vol. 27, No. 1(133) ( 2019-2-28), p. 78-84
    Details
    In: Fibres and Textiles in Eastern Europe, Walter de Gruyter GmbH, Vol. 27, No. 1(133) ( 2019-2-28), p. 78-84
    Abstract: Defined herein are the two PA-fabrics covering a paraglider wing, with the comparative object being permeable clothing material. The material parameters of textiles are applied in numerical simulations of aerodynamic characteristics using the program ANSYS. The state variable is the pressure within the airfoil profile. The space model of a paraglider wing and plane model of its cross-section in the symmetry plane are analysed. The model was approximated by the coordinates of crucial points and smoothed by the spline-curves. The visualisation of stream filaments shows that it is advisable to cover the wing with the impermeable fabric.
    Type of Medium: Online Resource
    ISSN: 1230-3666
    URL: Journal
    URL: Article
    DOI: 10.5604/12303666
    DOI: 10.5604/01.3001.0012.7511
    Language: English
    Publisher: Walter de Gruyter GmbH
    Publication Date: 2019
    detail.hit.zdb_id: 2125292-0
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  • 4
    Online Resource
    Online Resource
    Assessment of sleep disorders and use of psychoactive drugs among Polish students
    Komitet Redakcyjno - Wydawniczy Polskiego Towarzystwa Psychiatrycznego ; 2020
    In:  Psychiatria Polska Vol. 54, No. 5 ( 2020-10-31), p. 1007-1024
    Details
    In: Psychiatria Polska, Komitet Redakcyjno - Wydawniczy Polskiego Towarzystwa Psychiatrycznego, Vol. 54, No. 5 ( 2020-10-31), p. 1007-1024
    Abstract: Sleep disorders in the form of insomnia or excessive daytime sleepiness have their health and social consequences. The aim of the study was to evaluate the frequency of sleep disorders, quality of life and the pattern of psychoactive substance use among the students of Polish universities using CAVI method. Methods The Athens Insomnia Scale, the Epworth Sleepiness Scale, and the Manchester Short Assessment of Quality of Life were used. The study was conducted using anonymous and voluntary questionnaires distributed via the Internet. Results Most of the respondents (N = 5,342) were women (74%). A high percentage ( 〉 51%) of sleep disorders was found in women. Daytime sleepiness occurred in 28% of respondents, which correlated with sleep disorders. The use of psychoactive drugs is very common (94%) among Polish students of both sexes and (apart from alcohol) significantly affects the quality of life (p = 0.000). In the assessment of the psychoactive substance use pattern, the students of medical universities only slightly differ from students of other majors. The quality of life of people affected by sleep disorders is much lower than of the healthy student population. Conclusions The great scale of the sleep disorder phenomenon and the use of psychoactive substances among Polish students require further exploration with particular emphasis on preventive and therapeutic activities.
    Type of Medium: Online Resource
    ISSN: 0033-2674 , 2391-5854
    Uniform Title: Ocena zaburzeń snu i stosowania środków psychoaktywnych wśród polskich studentów
    URL: Article
    DOI: 10.12740/PP/111751
    Language: Polish
    Publisher: Komitet Redakcyjno - Wydawniczy Polskiego Towarzystwa Psychiatrycznego
    Publication Date: 2020
    detail.hit.zdb_id: 2833968-X
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  • 5
    Online Resource
    Online Resource
    Experimental and Numerical Determination of Strength Characteristics Related to Paraglider Wing with Fourier Transform Infrared Spectroscopy of Applied Materials
    MDPI AG ; 2022
    In:  Materials Vol. 15, No. 20 ( 2022-10-18), p. 7291-
    Details
    In: Materials, MDPI AG, Vol. 15, No. 20 ( 2022-10-18), p. 7291-
    Abstract: The aim of paper is to determine experimentally and numerically the strength characteristics related to the paraglider wing with Fourier transform infrared spectroscopy of applied materials. The applied method consists in theoretical modeling supplemented by the tests of material parameters. First, the set of 10 lightweight fabrics was selected for the tests; the samples are representative for these structures. The materials were tested using the spectroscopy to determine the FTIR spectra. The samples differ in the content of certain characteristic groups. Air permeability change of the materials was determined for the different pressure drops. The air permeability of almost all the analyzed samples was close to zero with the exception of only one material. The tensile strength and elongation at the break of samples were determined on the testing machine. The paraglider samples were characterized by slightly decreased mechanical properties compared to the parachute fabrics. The material characteristics determined during the tests are the input data for the theoretical analysis. The numerical model of the paraglider wing is based on a 3D geometry from previous research, but the stress, strain, and deformation were determined using the ANSYS Structural program and the finite elements method. To determine the strength correctly, we introduce two basic values: the absolute maximal and the representative values that are the biggest repetitive values of stress, strain, and deformation. The stress value was determined by the main factors: (i) the thinner the material, the bigger the stresses that were accumulated; (ii) the stronger the material, the bigger the stresses that were accumulated. The results are similar for all materials and differ mainly by the values. The biggest stresses were observed inside the material contacting the ribs, whereas the biggest deformation and strain were in the regions between ribs, and the smallest were in the contact areas with the fixed supports. Their highest intensity was observed on the leading edge of the paraglider. We conclude that the obtained stresses were far from the breaking level for the wing.
    Type of Medium: Online Resource
    ISSN: 1996-1944
    URL: Article
    DOI: 10.3390/ma15207291
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2487261-1
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  • 6
    Online Resource
    Online Resource
    Sensitivity of Aerodynamic Characteristics of Paraglider Wing to Properties of Covering Material
    Walter de Gruyter GmbH ; 2022
    In:  Autex Research Journal Vol. 22, No. 1 ( 2022-03-01), p. 64-72
    Details
    In: Autex Research Journal, Walter de Gruyter GmbH, Vol. 22, No. 1 ( 2022-03-01), p. 64-72
    Abstract: The paper is theoretically oriented. The main goal is to analyze the sensitivity of aerodynamic characteristics to the properties of the material used for paraglider wing. The paraglider of considerable dimensions is designed without stiffening elements. Thus, the covering material yields adequate pressure distribution between the external and internal parts of the wing. The problem is solved using a geometrical model approximated by the dimensionless coordinates of crucial points and smoothed by spline curves. The finite volume mesh is defined using the Ansys Meshing program. Numerical analysis uses five different covering materials, ranging from the air-impermeable covering to the covering subjected to hydrolytic—mechanical degradation. Optimization of properties of the covering material improves the lift force and the aerodynamic characteristics of the wing. Moreover, numerical modeling is more beneficial and efficient than prototype tests. The obtained pressure distributions and other parameters explain the aerodynamic safety of the paraglider during dynamic conditions of flight.
    Type of Medium: Online Resource
    ISSN: 2300-0929
    URL: Article
    DOI: 10.2478/aut-2020-0010
    Language: English
    Publisher: Walter de Gruyter GmbH
    Publication Date: 2022
    detail.hit.zdb_id: 2646010-5
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  • 7
    Online Resource
    Online Resource
    Direct and indirect surface geochemical methods in petroleum exploration: a case study from eastern part of the Polish Outer Carpathians
    Springer Science and Business Media LLC ; 2020
    In:  International Journal of Earth Sciences Vol. 109, No. 5 ( 2020-07), p. 1853-1867
    Details
    In: International Journal of Earth Sciences, Springer Science and Business Media LLC, Vol. 109, No. 5 ( 2020-07), p. 1853-1867
    Abstract: The objective of this paper is to evaluate the relationship between the distributions of direct and indirect, surface geochemical indices in the selected part of the Outer Carpathians. The research included analysis of molecular composition of soil gas samples and calcite contents as well as the measurements of magnetic susceptibility and pH of soil samples. The survey contained 96 soil gas samples collected from 1.2 m depth and 96 soil samples taken from interval 0.7–0.8 m depth. The maximum concentrations of methane, total alkanes C 2 –C 5 and total alkenes C 2 –C 4 were: 2100, 10.43 and 0.772 ppm. The magnetic susceptibility values changed from 3.6 to 21.5 x 10 –8 m 3 /kg. The calcium carbonate contents varied from 0.02 to 29.92 wt% and the pH values measured in soil solutions obtained changed from 4.5 to 8.3. Although the results demonstrate no correlation between the direct soil gas anomalies and the indirect geochemical indicators, the integrated profiles in Fig. 7 suggest possible haloes in the calcite/magnetic data that could be related to hydrocarbons migrating from depth. There are, however, various independent mechanisms that might control the appearance of these mineral anomalies. Secondary changes of mineral composition of soils disclosed by the indirect methods, even if controlled by hydrocarbon migration throughout geological time, might cause some closure of migration pathways, influencing the location of active hydrocarbon migration pathways. Comprehensive interpretation of the results obtained by direct and indirect methods in this paper provides another positive example helping to better understand the complicated mechanism of hydrocarbon migration and the potential usefulness of indirect methods suitable for hydrocarbon exploration.
    Type of Medium: Online Resource
    ISSN: 1437-3254 , 1437-3262
    URL: Article
    DOI: 10.1007/s00531-020-01876-y
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2020
    detail.hit.zdb_id: 1477582-7
    detail.hit.zdb_id: 1477600-5
    detail.hit.zdb_id: 2075432-2
    SSG: 13
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  • 8
    Online Resource
    Online Resource
    Influence of Material Degradation on Deformation of Paraglider during Flight
    MDPI AG ; 2023
    In:  Materials Vol. 16, No. 15 ( 2023-08-01), p. 5396-
    Details
    In: Materials, MDPI AG, Vol. 16, No. 15 ( 2023-08-01), p. 5396-
    Abstract: The aim of this article is to determine experimentally and numerically the influence of material degradation on the deformation of a paraglider during flight. The presented method regards numerical modeling of pressure distribution over the wing and its effect on paraglider behavior; the considerations are preceded by experiments on three types of Polyamide 6.6 paraglider fabrics, subjected and not subjected to thermal, UV and flexing degradation. Scanning electron microscope (SEM) records allowed to determine the structural characteristics of the analyzed samples. Air permeability and mechanical tests are the input data for the computational simulations. When a pressure drop of 200 Pa is applied, all the analyzed samples are impermeable, except for those damaged by flexing. Thus, flexing damage has the greatest influence on the air permeability change among all considered aging factors. Aging caused by UV radiation has the greatest influence on mechanical properties. No major influence of thermal ageing on the mechanical properties of the considered samples is observed. Safety factors of the considered materials not subjected to degradation range between 3.94 and 6.00. Safety factor of fabric no. 1 subjected to the UV degradation is equal to 1.33; this result does not secure a safe usage of the considered material. The methodology described in this research can help to predict paraglider covering materials’ behavior in flight; it assumes many cases, i.e., applying a new material or the material at any point of its life cycle. Thus, the practical implications of this model supported by numerical methods may result in saving time and cost in producing prototypes, as well as potentially assessing the safety of used wings. Future research activity can introduce the application of different elastic–plastic damage models to determine the paraglider behavior during collapse.
    Type of Medium: Online Resource
    ISSN: 1996-1944
    URL: Article
    DOI: 10.3390/ma16155396
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2487261-1
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