137 research outputs found
Static Buckling of FML Columns in Elastic-Plastic Range.
The paper deals with the elasto-plastic buckling of thin-walled Fiber Metal Laminates short columns/profiles subjected to axial uniform compression. Structures of open and hollow (closed) cross-sections are considered build of
at plate walls. Multilayered FML walls are considered as built of alternating layers of aluminum and fiber-glass composite. Three elastic-plastic theories are employed for constitutive relations description of aluminum layers i.e. fully elastic material behavior, the J2-deformation theory of plasticity and the J2 flow theory later both with Ramberg-Osgood formula application, whereas composite layers are assumed elastic within whole loading range. Some exemplary results determined with the application of own analytical-numerical method based on the Koiter's theory, in the Byskov and Hutchinson formulation are enclosed in the form of tables and plots
Static and Dynamic Thermomechanical Buckling Loads of Functionally Graded Plates.
In the paper the buckling phenomenon for static and dynamic loading (pulse of finite
duration) of FGM plates subjected to simultaneous action of one directional compression and thermal field is presented. Thin, rectangular plates simply supported along all edges are considered. The investigations are conducted for different values of volume fraction exponent and uniform temperature rise in conjunction with mechanical dynamic pulse loading of finite duration
Inuence of Foam Filling on Dynamic Response of Hemispherical Shell Subjected to Blast Pressure.
The paper aims to investigate the effect of aluminium foam filling of hemispherical steel shell on its dynamic response, accounting for the blast pressure modelling. The considered structures subjected to uniformly distributed pressure, rigidly connected with a steel plate, are considered. True material stress–strain curves for shell and foam filling are assumed in calculations. The problem is solved by FEM using ANSYS software. The time relations of strain energy and effective stresses for different simulations of blast pressure are determined and compared for steel shells and shells filled with aluminum foam
Introduction
The aim of this publication is to look at the problems of Polish rural areas from the perspective of the young generation of researchers, to show what problems they are interested in and what study methods and techniques they use to describe the phenomena occurring in Polish villages. The results of their studies were also presented to underscore the importance of these phenomena for the development of knowledge concerning the dynamic transformations in Polish rural areas. The Authors represent different fields of study (sociology, ethnography, economy and geography) from renowned academic centres such as University of Lodz, Institute of Rural and Agricultural Development, Polish Academy of Sciences (IRWiR PAN) in Warsaw, Life Science University of Poznan, Technical University in Warsaw, Institute of Urban Development in Krakow, and Maria Grzegorzewska University. What they have in common is interest in the problems of rural areas and their residents. They focus on the new model of rural development, very often identified with concepts such as multifunctional and sustainable development, on social innovation, the subject of transformations in rural residents' social roles, including rural women serving public roles, as well as on the strategies of coping with the reality used by residents of marginalized villages. The articles introduce the Readers to selected problems of development of Polish rural areas and help them to understand their complexity.Praca w części dofinansowana przez Polską Akademię Nauk / Polish Academy of Sciences IRWiR PAN / Institute of Rural and Agricultural Development, 00-330 Warszawa, ul. Nowy Świat 72, Poland
Coexistence of vitreomacular traction and exudative age-related macular degeneration. A case report
Vitreomacular traction is a common phenomenon causing a decrease in visual acuity, metamorphopsia, and disorders of central vision. The introduction of intravitreal ocriplasmin injection provided a new possibility of noninvasive treatment of this syndrome. The novelty of this case is that the ocriplasmin is a new treatment possibility and its combination with ranibizumab treatment has rarely been reported. The aim was to report a case of an 83-year-old man treated with intravitreal ocriplasmin and ranibizumab injections because of coexisting vitreomacular traction and exudative age-related macular degeneration. A patient was referred to our clinic due to complaints about progressive central visual acuity decrease and metamorphopsia in the right eye observed within the last year. Before intravitreal 125-μg ocriplasmin injection the patient underwent ophthalmic examinations including best corrected visual acuity, slit-lamp, and fundoscopy and optical coherence tomography. After diagnosing with exudative age-related macular degeneration the patient was referred to three loading doses of anti-VEGF therapy. Three weeks after ocriplasmin injection the patient’s best corrected visual acuity improved. Ophthalmic examinations revealed the occurrence of exudative age-related macular degeneration. After three loading doses of anti-VEGF therapy ophthalmic examinations disclosed vitreomacular traction release and retinal fluid absorption. Coexistence of vitreomacular diseases may be the reason for poor response to anti-VEGF treatment in patients with exudative age-related macular degeneration. Simultaneously, pharmacological vitreolysis using ocriplasmin injection may be an effective and safe method of vitreomacular traction treatment.
Static and dynamic buckling of functionality graded plates subjected to thermomechanical loading
Analysis of faecal bacteria isolated from air and seawater samples following an emergency sewage discharge into the Gulf of Gdansk in 2018 — preliminary study
Background: Knowing the numbers of bacteria in coastal atmospheric air as well as in coastal waters significantly contributes to a better understanding of the processes affecting the health of people who stay temporarily or permanently in areas where the synergistic effect of the atmospheric conditions and the aquatic environment on a human body is particularly strong.
Materials and methods: Seawater and air samples were collected from 22 May to 22 July 2018 in the seaside towns of Hel, Puck, Gdynia, Sopot, Gdansk-Brzezno, all located along the Gulf of Gdansk. The number of psychrophilic, mesophilic as well as coliform bacteria and Escherichia coli was determined in both the water and the ambient air samples. In total, 232 seawater and coastal air samples were collected for the study purposes.
Results: The study showed a deterioration of coastal waters and atmospheric air in the Gulf of Gdansk which may have resulted from an increase of potentially pathogenic mesophilic bacteria following the emergency discharge of raw sewage from the Gdansk-Wschod wastewater plant.
Conclusions: An increase in the number of coliform bacteria and Escherichia coli in the seawater and in the air across the Gulf of Gdansk is related to the emergency sewage discharge
Influence of foam filling on dynamic response of hemispherical shell subjected to blast pressure
OCT angiography as a novel diagnostic possibility in age-related macular degeneration
INTRODUCTION. The aim of the study is to compare classical vein imaging methods used to diagnose Age-related Macular Degeneration (AMD), like fluorescein angiography (FA), with non-invasive modern methods of ultrafast optical blood flow detection (Optical Coherence Tomography-angiography, Angio-OCT).
METHODS. Images obtained during examination using AF and Angio-OCT methods of four randomly selected patients treated for AMD in the Department of Ophthalmology Medical University of Silesia, Katowice, Poland were used for evaluation.
RESULTS. Images obtained during routine check-up of patients treated for AMD were compared.
CONCLUSIONS. Angio-OCT is a non-invasive, non-contact, fast, and safe examination of patients treated for AMD. Angio-OCT is a modern method that provides important information about the progression of the disease, and it is used to evaluate retinal and choroidal vessels in patients with AMD
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