12 research outputs found

    Hybrid flexible (HyFlex) seminar delivery – A technical overview of the implementation

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    This paper investigates a new technology for Hybrid flexible delivery (known as HyFlex), as implemented at King's College London. The relatively novel character of HyFlex, of mixing synchronously on-line and in-room teaching, and the recent changes due to the COVID-19 pandemic mean this use of the technology and teaching model is largely new to the UK. This research evaluated audio quality in the context of a HyFlex technical environment. The paper provides a high-level overview of the process of designing a HyFlex solution and presents a detailed evaluation of the impact of reverberation in relation to the accuracy of automatically generated subtitles and the influence of microphone selection. The paper shows that there was a significant relationship between the reverberation, the audio quality, and the subtitling system, which is important as past studies highlighted audio quality is key for the students' experience. It presents a viable and simple methodology to estimate the audio quality on installed HyFlex systems to improve the students experience in a hybrid teaching environment

    Nowa kronika wałbrzyska, t. 3

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    Wałbrzych i jego słynny „złoty pociąg”, od pierwszej wzmianki na jego temat, zajmuje obecnie szczególne miejsce w wielu informacjach publicystycznych i naukowych. Na nowo rozbudzona ciekawość historyczna naszym miastem i regionem zbiegła się z siedemdziesiątą rocznicą przejęcia miasta przez władze polskie. Każdy niemalże mieszkaniec Wałbrzycha odczuwa ten pozytywny wzrost zainteresowania. Przygraniczne położenie, wielonarodowe wpływy w rozwoju politycznym, gospodarczym i kulturalnym odcisnęły swoje piętno na dziejach miasta, widzianych przez nas jako ciągłość od czasów najdawniejszych po czasy współczesne. I właśnie ta różnorodność stała się nagle niezwykle atrakcyjnym elementem dla przybywających tu turystów zaintrygowanych tajemniczymi historiami. Kolejny, trzeci tom Nowej kroniki wałbrzyskiej stara się jak zwykle uwzględnić wyniki najnowszych prac naukowych lokalnych badaczy, jak i wykorzystać te ustalenia, które posiadają istotną wartość poznawczą. Jak pisze Andrzej Garlicki „Najtrudniejsze w historii jest zrozumienie. Czyli odpowiedź na pytanie, dlaczego wydarzenia potoczyły się tak, a nie inaczej”, dlatego też staramy się zapewnić Czytelnikom szerokie spectrum poruszanych problemów oraz różne wątki wałbrzyskiej historii, podzielone na cztery części.Elżbieta Kwiatkowska-Wyrwis

    Hybrid flexible (HyFlex) teaching and learning: climbing the mountain of implementation challenges for synchronous online and face-to-face seminars during a pandemic.

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    In 2020, King's College London introduced HyFlex teaching as a means to supplement online and face-to-face teaching and to respond to Covid-19 restrictions. This enabled teaching to a mixed cohort of students (both online and on campus). This article provides an outline of how such an approach was conceptualized and implemented in a higher-education institution during an intense three-month period over that summer and prior to the limited re-opening of the university campus. This was a new approach that offers a number of pointers for reflection and provides key insights in on this novel learning environment and the physical and pedagogical contexts in which learning can occur. Technical implementation factors are detailed, along with both reflections on challenges and solutions. Pedagogical issues such as cognitive load, social presence, and resolving the issues of a cohort spread across two locations are discussed. While we should be mindful of the limitations of this relatively-specific research, and shouldn't therefore over-extrapolate our findings, one key finding is that delivering Hyflex is associated with a higher cognitive load. Further, the audio quality of our implementation enhanced the feeling of presence in the learning environment. We recommend providing appropriate technical and pedagogical training, as well as audio-visual and digital education support. [Abstract copyright: © The Author(s) 2022.

    The impact assessment of environmental conditions on the corrosion resistance of titanium alloy Ti6Al4V

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    W celu przeprowadzenia oceny wpływu zmian składu chemicznego środowiska biologicznego na odporność korozyjną popularnego w implantologii stopu tytanu Ti6Al4V, przeprowadzono badania elektrochemiczne. Jako podstawowe środowisko korozyjne wykorzystano roztwór Ringera (pH=6,5), w którym badano wymieniony powyżej stop metalu. Dla zaburzenia jego składu chemicznego dodano glukozę oraz kwas askorbinowy tworząc tym samym roztwory korozyjne o pH odpowiednio 6,2 i 3,5. Otrzymane wyniki wskazują, że zakwaszenie środowiska wskutek obecności w roztworze Ringera kwasu askorbinowego najefektywniej wpływa na odporność korozyjną Ti6Al4V.Titanium alloys are mainly used for the production of endoprosthesis, dental implants. This study presents the impact assessment of the physiological environment on a corrosion behavior of the titanium alloy Ti6Al4V. The corrosive environment consisted of three solutions with different pH: Ringer's solution (pH=6.5), Ringer's solution containing glucose (pH=6.2), Ringer's solution with ascorbic acid (pH=3.5). The study was carried out by using electrochemical researches. It included the measurement potential of the open circuit and the relation i=f(E). With the obtained results, it was found that Ti6Al4V alloy has the best corrosion resistance in acidic environment

    Assessment of selected structural properties of orthodontic arches

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    Badania eksploatacyjne dwuwirnikowej mini elektrowni wiatrowej

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    W artykule przedstawiono wyniki badań dwuwirnikowej mini elektrowni wiatrowej przeprowadzone w tunelu aerodynamicznym oraz w terenie. W pierwszym etapie testowano zbudowany w celu przeprowadzenia badań laboratoryjnych tunel aerodynamiczny o konstrukcji otwartej. Wyznaczony współczynnik nierównomierności strugi powietrza przy prędkości nominalnej wynosił 1,7%, natomiast wskaźnik intensywności turbulencji w całym zakresie pomiarowym zawierał się w granicach 1,2-1,8%. Budując mini elektrownię wiatrową wyposażono ją w wirniki w których zastosowano nową konstrukcję łopat. Zastosowane łopaty w porównaniu do zbliżonej konstrukcji łopat stosowanych w mini elektrowniach dostępnych na rynku charakteryzowały się sprawnością wynoszącą 0,28. Po wykonanych badaniach eksploatacyjnych w tunelu aerodynamicznym uzyskane wyniki poddano ocenie statystycznej z wykorzystaniem współczynników korelacji liniowej Pearsona oraz rangi Spearmana. Zbadano zależności między zmienną zależną (moc P) oraz zmiennymi niezależnymi (średnie prędkości strugi powietrza V, kąt zaklinowania łopat pierwszego wirnika α1, kąt zaklinowania łopat drugiego wirnika α2, odległości pomiędzy wirnikami l). Na podstawie analizy, zgodnie z oczekiwaniem, stwierdzono, że najsilniejsza korelacja występuje w odniesieniu do prędkości strugi powietrza. Wpływ na moc mają także kąty zaklinowania na obu wirnikach, natomiast nie stwierdzono takiego wpływu w przypadku zmian odległości pomiędzy wirnikami turbiny. Badania w terenie potwierdziły ustalenia i spostrzeżenia poczynione w tunelu aerodynamicznym.The article presents the results of wind-tunnel tests and field studies of a mini dual-rotor wind turbine. The first stage involved testing of an open-circuit wind tunnel built with the aim of performing laboratory tests. The coefficient of uneven air stream distribution at a rated speed was 1.7%, while the index of turbulence intensity in the entire measurement range was between 1.2 and 1.8%. The mini wind turbine was equipped with rotors with new design blades. Compared to the blade designs used in mini wind turbines available on the market, the blades used in the present study were characterized by an efficiency of 0.28. The results of performance tests in the wind tunnel were evaluated statistically using Pearson correlation coefficients and Spearman’s rank. We examined the relationship between a dependent variable (power P) and independent variables (average air stream speed V, incidence angle of the blades of the first rotor α1, incidence angle of the blades of the second rotor α2, and the distance between the rotors l). The analysis showed, as expected, that the strongest correlation was between power and speed of the air stream. While incidence angles of the two rotors also affected the turbine’s power, no such effect was observed for changes in the distance between the rotors. Field tests confirmed the findings and observations made in the wind tunnel

    Corneal pulsation and biomechanics during induced ocular pulse. An ex-vivo pilot study.

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    The purpose of this study was to ascertain the relationships between the amplitude of the corneal pulse (CP) signal and the parameters of corneal biomechanics during ex-vivo intraocular pressure (IOP) elevation experiments on porcine eyes with artificially induced ocular pulse cycles. Two experiments were carried out using porcine eyes. In the first one, a selected eye globe was subjected to three IOP levels (15, 30 and 45 mmHg), where changes in physical ocular pulse amplitude were controlled by infusion/withdrawal volumes (ΔV). In the second experiment, six eyes were subjected to IOP from 15 mmHg to 45 mmHg in steps of 5 mmHg with a constant ΔV, where corneal deformation parameters were measured using Corvis ST. In both experiments, at each IOP, the CP and IOP signals were acquired synchronically using a non-contact ultrasonic distance sensor and a pressure transmitter, respectively. Based on the amplitudes of the CP and IOP signals ocular pulse based corneal rigidity index (OPCRI) was calculated. Results indicate positive correlations between ΔV and the physical ocular pulse amplitude, and between ΔV and the corneal pulse amplitude (both p < 0.001). OPCRI was found to increase with elevated IOP. Furthermore, IOP statistically significantly differentiated changes in OPCRI, the amplitudes of CP and IOP signals and in most of the corneal deformation parameters (p < 0.05). The partial correlation analysis, with IOP as a control variable, revealed a significant correlation between the length of the flattened cornea during the first applanation (A1L) and the corneal pulse amplitude (p = 0.002), and between A1L and OPCRI (p = 0.003). In conclusion, this study proved that natural corneal pulsations, detected with a non-contact ultrasonic technique, reflect pressure-volume dynamics and can potentially be utilized to assess stiffness of the cornea. The proposed new rigidity index could be a simple approach to estimating corneal rigidity

    A Review on the Adaption of Alginate-Gelatin Hydrogels for 3D Cultures and Bioprinting

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    Sustaining the vital functions of cells outside the organism requires strictly defined parameters. In order to ensure their optimal growth and development, it is necessary to provide a range of nutrients and regulators. Hydrogels are excellent materials for 3D in vitro cell cultures. Their ability to retain large amounts of liquid, as well as their biocompatibility, soft structures, and mechanical properties similar to these of living tissues, provide appropriate microenvironments that mimic extracellular matrix functions. The wide range of natural and synthetic polymeric materials, as well as the simplicity of their physico-chemical modification, allow the mechanical properties to be adjusted for different requirements. Sodium alginate-based hydrogel is a frequently used material for cell culture. The lack of cell-interactive properties makes this polysaccharide the most often applied in combination with other materials, including gelatin. The combination of both materials increases their biological activity and improves their material properties, making this combination a frequently used material in 3D printing technology. The use of hydrogels as inks in 3D printing allows the accurate manufacturing of scaffolds with complex shapes and geometries. The aim of this paper is to provide an overview of the materials used for 3D cell cultures, which are mainly alginate–gelatin hydrogels, including their properties and potential applications

    A Review on the Adaption of Alginate-Gelatin Hydrogels for 3D Cultures and Bioprinting

    No full text
    Sustaining the vital functions of cells outside the organism requires strictly defined parameters. In order to ensure their optimal growth and development, it is necessary to provide a range of nutrients and regulators. Hydrogels are excellent materials for 3D in vitro cell cultures. Their ability to retain large amounts of liquid, as well as their biocompatibility, soft structures, and mechanical properties similar to these of living tissues, provide appropriate microenvironments that mimic extracellular matrix functions. The wide range of natural and synthetic polymeric materials, as well as the simplicity of their physico-chemical modification, allow the mechanical properties to be adjusted for different requirements. Sodium alginate-based hydrogel is a frequently used material for cell culture. The lack of cell-interactive properties makes this polysaccharide the most often applied in combination with other materials, including gelatin. The combination of both materials increases their biological activity and improves their material properties, making this combination a frequently used material in 3D printing technology. The use of hydrogels as inks in 3D printing allows the accurate manufacturing of scaffolds with complex shapes and geometries. The aim of this paper is to provide an overview of the materials used for 3D cell cultures, which are mainly alginate–gelatin hydrogels, including their properties and potential applications
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