Iskanje po katalogu digitalne knjižnice

Opis: With their unique physicochemical properties, such as metallic-like conductivity, favorable (electro)catalytic properties, electrochemical stability, and ease of functionalization, pyrochlores have found applications in various fields such as solid oxide fuel cells, batteries, thick film resistors, and temperature sensors; however, there are no reports on their application in electrochemical immunosensing. In this study, we exploited the (electro)catalytic nature and stability of the pyrochlore Bi2Ru2O7 clusters silanized with (3-aminopropyl)triethoxysilane (APTES) to demonstrate their potential for the effective stacking of functional proteins. Characterization of the clusters by XPS disclosed a dual environment of Bi, also indicating the presence of Bi2O3 alongside APTES-Bi2Ru2O7 clusters and, importantly, the predominant involvement of pyrochlore moieties in subsequent protein stacking. After stacking protein A and antibodies, the immunosensor revealed a nearly interference-free operation, high sensitivity, a detection limit of 118 fM SARS-CoV-2 spike protein, and operation in a wide examined concentration range of 10−5−10−1 μg mL−1 with an r2 of 0.98. In combination with a short incubation time of 30 min, the pyrochlore-based immunosensor provides a solid platform for future point-of-need applications.
Ključne besede: Bi2Ru2O7 pyrochlore, APTES, SARS-CoV-2, spike protein, immunosensors, electrochemical
Objavljeno v DKUM: 23.04.2025; Ogledov: 0; Prenosov: 0
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Opis: Au nanoparticles supported on ZrO2 enhance its surface acidic/basic properties to produce a high yield of methanol via the hydrogenation of CO2. Amorphous ZrO2-supported 0.5–1 wt.% Au catalysts were synthesized by two methods, namely deposition precipitation (DP) and impregnation (IMP), characterized by a variety of techniques, and evaluated in the process of CO2 hydrogenation to methanol. The DP-method catalysts were highly advantageous over the IMP-method catalyst. The DP method delivered samples with a large surface area, along with the control of the Au particle size. The strength and number of acidic and basic sites was enhanced on the catalyst surface. These surface changes attributed to the DP method greatly improved the catalytic activity when compared to the IMP method. The variations in the surface sites due to different preparation methods exhibited a huge impact on the formation of important intermediates (formate, dioxymethylene and methoxy) and their rapid hydrogenation to methanol via the formate route, as revealed by means of in situ DRIFTS (diffuse reflectance infrared Fourier transform spectroscopy) analysis. Finally, the rate of formation of methanol was enhanced by the increased synergy between the metal and the support.
Objavljeno v DKUM: 10.04.2025; Ogledov: 0; Prenosov: 3
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Opis: Young people play a pivotal role in instigating and driving significant changes. The impact of individuals’ involvement in environmental conservation, community development, and social change initiatives for sustainable value creation is of considerable importance in the pursuit of the sustainable development goals (SDGs). The objective of this study is to examine the contribution of youth engagement in the creation of sustainable value by analyzing their comprehension and prioritization of the 17 SDGs, with the goal of achieving sustainable development and sustainability. The researchers conducted a study on a sample of 1085 individuals between the ages of 14 and 30, who were selected from three distinct countries within the Western Balkan region—the Republic of Serbia, Bosnia and Herzegovina, and the Republic of Northern Macedonia. The data were analyzed using factor analysis in conjunction with descriptive and inferential statistics. The survey findings indicate that poverty, hunger, and access to adequate healthcare are the primary SDGs and societal challenges confronting the youth in these nations. Furthermore, it emphasizes the significance of both formal and informal education among youth as a catalyst for societal transformation for sustainable value creation.
Ključne besede: youth, youth participation, sustainable value creation, sustainable development goals, prioritization of sustainable development goals
Objavljeno v DKUM: 07.04.2025; Ogledov: 0; Prenosov: 2
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Opis: Quantitative analysis of visual arts has recently expanded to encompass a more extensive array of artworks due to the availability of large-scale digitized art collections. Consistent with formal analyses by art historians, many of these studies highlight the significance of encoding spatial structures within artworks to enhance our understanding of visual arts. However, defining universally applicable, interpretable, and sufficiently simple units that capture the essence of paintings and their artistic styles remains challenging. Here, we examine ordering patterns in pixel intensities within two-by-two partitions of images from nearly 140,000 paintings created over the past 1,000 years. These patterns, categorized into 11 types based on arguments of continuity and symmetry, are both universally applicable and detailed enough to correlate with low-level visual features of paintings. We uncover a universal distribution of these patterns, with consistent prevalence within groups, yet modulated across groups by a nontrivial interplay between pattern smoothness and the likelihood of identical pixel intensities. This finding provides a standardized metric for comparing paintings and styles, further establishing a scale to measure deviations from the average prevalence. Our research also shows that these simple patterns carry valuable information for identifying painting styles, though styles generally exhibit considerable variability in the prevalence of ordinal patterns. Moreover, shifts in the prevalence of these patterns reveal a trend in which artworks increasingly diverge from the average incidence over time; however, this evolution is neither smooth nor uniform, with substantial variability in pattern prevalence, particularly after the 1930s.
Ključne besede: spatial patterns, complexity, esthetic measure, art history, social physics
Objavljeno v DKUM: 01.04.2025; Ogledov: 0; Prenosov: 3
Celotno besedilo (9,19 MB)
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Opis: In filling lines equipped with membrane separation devices in the form of filters energy, consumption is only one of the important working parameters, the other being sustainable filter performance in terms of separation efficiency. As the filling line is typically equipped with a valve, intermittent operation of the filter is an important form of its use. Whereas the overall energy consumption of the filtration process is governed by the continuous operation mode, the intermittent mode, characterised by opening/closing of the valve, contributes most to problems of filter failure, i.e., the breakthrough of filtered particles through the membrane. A model for determination of the energy intake of a microfiltration membrane during the opening and closing of a valve is presented in this work. The model is based on computational analysis of the pressure wave signals recorded during the opening/closing of the valve using Fourier transform, and expressed in a nondimensional filter area specific energy intake form. The model is applied to a case of constant pressure dead-end microfiltration with three filter types: a single membrane filter, a stacked filter and a pleated filter with filtration surface areas ranging from 17.7 cm2 to 2000 cm2. Both clean filters, as well as partially clogged filter cases are taken into account. Second order polynomial models of the energy intake are developed and evaluated based on extensive analysis of the experimental data. The analysis of energy intake results show that the largest energy intake was observed for the clean filter case. When membrane fouling occurs at the constant flow rate values it leads to larger energy intake, however, due to a decreasing specific flow rate during fouling these values do not exceed the clean filter case.
Ključne besede: membrane filtration, water hammer effect, membrane energy intake, filter clogging
Objavljeno v DKUM: 28.03.2025; Ogledov: 0; Prenosov: 1
Celotno besedilo (4,01 MB)
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