Variable Exponent Sobolev Spaces and Regularity of Domains

Indexación: Scopus.We study the embeddings of variable exponent Sobolev and Hölder function spaces over Euclidean domains, providing necessary and/or sufficient conditions on the regularity of the exponent and/or the domain in various contexts. Concerning the exponent, the relevant condition is log-Hölder continuity; concerning the domain, the relevant condition is the measure density condition.https://link.springer.com/article/10.1007%2Fs12220-020-00499-

Relationship between the Clinical Frailty Scale and short-term mortality in patients ≥ 80 years old acutely admitted to the ICU: a prospective cohort study.

BACKGROUND: The Clinical Frailty Scale (CFS) is frequently used to measure frailty in critically ill adults. There is wide variation in the approach to analysing the relationship between the CFS score and mortality after admission to the ICU. This study aimed to evaluate the influence of modelling approach on the association between the CFS score and short-term mortality and quantify the prognostic value of frailty in this context. METHODS: We analysed data from two multicentre prospective cohort studies which enrolled intensive care unit patients ≥ 80 years old in 26 countries. The primary outcome was mortality within 30-days from admission to the ICU. Logistic regression models for both ICU and 30-day mortality included the CFS score as either a categorical, continuous or dichotomous variable and were adjusted for patient's age, sex, reason for admission to the ICU, and admission Sequential Organ Failure Assessment score. RESULTS: The median age in the sample of 7487 consecutive patients was 84 years (IQR 81-87). The highest fraction of new prognostic information from frailty in the context of 30-day mortality was observed when the CFS score was treated as either a categorical variable using all original levels of frailty or a nonlinear continuous variable and was equal to 9% using these modelling approaches (p < 0.001). The relationship between the CFS score and mortality was nonlinear (p < 0.01). CONCLUSION: Knowledge about a patient's frailty status adds a substantial amount of new prognostic information at the moment of admission to the ICU. Arbitrary simplification of the CFS score into fewer groups than originally intended leads to a loss of information and should be avoided. Trial registration NCT03134807 (VIP1), NCT03370692 (VIP2)

Functional annotation of the cattle genome through systematic discovery and characterization of chromatin states and butyrate-induced variations

The functional annotation of genomes, including chromatin accessibility and modifications, is important for understanding and effectively utilizing the increased amount of genome sequences reported. However, while such annotation has been well explored in a diverse set of tissues and cell types in human and model organisms, relatively little data are available for livestock genomes, hindering our understanding of complex trait variation, domestication, and adaptive evolution. Here, we present the first complete global landscape of regulatory elements in cattle and explore the dynamics of chromatin states in rumen epithelial cells induced by the rumen developmental regulator—butyrate.https://doi.org/10.1186/s12915-019-0687-

New technologies basing on friction stir welding of metals

W pracy w znacznym skrócie przedstawiono aktualny stan wiedzy na temat dynamicznie rozwijanych w ostatnich latach nowych technologii wykorzystujących proces łączenia tarciowego materiałów. Omówiono metody: FSP (Friction Stir Processing) i FSW (Friction Stir Welding). Skoncentrowano się na tych zastosowaniach omawianych metod, w których zaobserwowano znaczny wzrost wytrzymałości zmęczeniowej i odporności korozyjnej konstrukcyjnych materiałów nośnych.The state-of-the art in the field of new manufacturing technologies developed in the last years, which are based on friction stir welding/processing of materials (FSP and FSW), is the subject of the paper. The main attention was focused on the application of these techniques in surface engineering which lead to materials and products with higher performance, higher fatigue strength, and corrosion toughness

Selected problems of the S235JR and S355JR steels enriching with chromium using a CO₂ continuous wave laser

Zagadnieniem rozważanym w pracy jest wzbogacanie warstwy wierzchniej stali kadłubowych S235JR i S355J2 chromem w celu zwiększenia ich odporności na działania korozyjne wody morskiej. Podjęto próbę wyjaśnienia mechanizmu tworzenia stabilnych struktur w głębi warstw dyfuzyjnych przy domieszkowaniu stali chromem. Jako modelowego aktywatora termodynamicznych zjawisk, zachodzących podczas tego procesu z zastosowaniem zmodyfikowanej metody zgrzewania tarciowego FSP (Friction Stir Processing), użyto wiązki promieniowania laserowego. Analizowano dyfuzyjny transport masy, który jest pierwotnym i dominującym zjawiskiem w przemianach fazowych zachodzących w mikroobszarach o znacznym gradiencie temperatury w procesie tworzenia cienkich warstw antykorozyjnych. Przedstawiono rozkłady stężenia chromu w warstwie dyfuzyjnej stali, wynikające ze wzorów analitycznych podanych w pracy i z własnych pomiarów doświadczalnych, otrzymanych przy wydłużonym i skróconym czasie nagrzewania wiązką laserową powłoki galwanicznego chromu osadzonej na podłożu stalowym.The paper deals with the problem of the S235JR and S355J2 hull steels enriching with chromium in order to improve their corrosive resistance against sea water. The attempts were undertaken to explain the mechanism of formation of durable layers inside the diffusion zone while the steel alloying process is providing. In the research to model the process of surface layer steel modification by means of modified friction stir processing (FSP), a continuous wave CO₂ laser beam was served as a model activator of thermodynamical phenomena appearing there. Mainly, diffusive mass transport was considered in the work as it being the original and basic phenomenon affected in the phase transformations. The theoretical and experimental concentration distributions of chromium inside the diffusive layers being diffused from galvanic coating of steel matrix were performed in the paper for short and long laser exposition time. Thanks determining in the work the conditions for collaboration of the concentration diffusion component as well the complex thermodiffusive mass transport, it is possible to design the structure and the thickness of diffusive layers in the matrix

Model of Fe-Cr type diffusion layer formation in a thermal field

W artykule przedstawiono model tworzenia warstw dyfuzyjnych na przykładzie chromu, jako elementu nasycającego, i żelaza jako elementu nasycanego w polu laserowej inicjacji cieplnej z zastosowaniem lasera CO₂ emitującego wiązkę o normalnym rozkładzie gęstości mocy w trybie pracy ciągłej. Zamieszczone w pracy wyniki badań weryfikacyjnych dokumentują istnienie termodyfuzyjnego strumienia masy w strefie nagrzewanego materiału. Proces ten jest dominujący w pierwszym, wyodrębnionym w tym modelu etapie tworzenia warstwy, to jest w czasie nagrzewania materiału. Obserwowane efekty oddziaływania tego strumienia na strukturę w modyfikowanej warstwie uzależnione były w pierwszym rzędzie od czasu realizacji procesu oraz od parametrów cieplno-geometrycznych obszaru wpływu ciepła, takich jak: głębokość przetopienia i grubość zastosowanej powłoki chromu nałożonego galwanicznie. Przy spełnieniu odpowiednich warunków relacji pomiędzy wymienionymi parametrami, rozkłady stężenia chromu posiadały maksima w głębi warstw, a nie na powierzchni, jak ma to miejsce w konwencjonalnych procesach dyfuzyjnych realizowanych przy stałej temperaturze.In the paper, the model of formation of the Fe-Cr diffusion layer on a carbon steel substrate in the thermal field produced by continuous laser beam with normal power density distribution is presented. Here, the enclosed results of verification investigations prove that thermodifusional mass transport is a dominant phenomenon in the first stage of the diffusion layer formation process when the chromium galvanic surface layer is under heating. The effect of the thermodiffusion flux action depends on the heating period as well as on thermo-geometrical parameters of the heat affected zone such as melting depth and the thickness of the chemical chromium layer coating on the steel substrate. While the particular relations between the above mentioned parameters of heat affected zone are satisfied then the maximum values of chromium concentration distribution can be found in the depth of diffusion layer. It seems to be on contrary to the conventional diffusion process running under constant temperature whereas the maximum concentration of chromium metal is found on the surface of diffusion layer

Laser cladding of Inconel 625-based composite coatings

Artykuł prezentuje wyniki badań procesu napawania laserem diodowym warstw wierzchnich kompozytowych na osnowie stopu niklu Inconel 625 wzmacnianych cząstkami WC oraz Cr3C2. Określono wpływ energii linowej napawania oraz morfologii cząstek fazy umacniającej (FU) na stopień jej rozpuszczenia w osnowie warstwy. Ponadto, określono wpływ morfologii cząstek FU na odporność erozyjną warstw.Inconel 625-based composite coatings reinforced by WC and Cr3C2 particles have been produced via a diode laser cladding process. The effect of heat input level and morphology of the reinforcing particles on the degree of their dissolution has been established. Additionally, the influence of the morphology of the reinforcing particles on the erosive wear behaviour of the coatings was studied

The effect of storage time on selected mechanical properties of potatoes

This paper describes a the effect of storage time on selected mechanical properties of potatoes, method for determining the impact strength and dynamic shear strength of potatoes on a test stand designed by the authors. The results of preliminary tests examining the effect of storage time on the average impact bending strength and shear strength values of potatoes cv. Irga are also presented. The above parameters and changes in their values during storage time have to be determined to support the optimization of technological processes in the food processing industry, including the production of French fries and potato chips