Sorbitol, a product primarily derived from glucose hydrogenation, has extensive applications in the pharmaceutical, chemical and other industries. Amino styrene-co-maleic anhydride polymer ...encapsulated on activated carbon (Ru/ASMA@AC) catalysts were developed for efficient glucose hydrogenation and were prepared and confined Ru by coordination with styrene-co-maleic anhydride polymer (ASMA). Through single-factor experiments, optimal conditions were determined to be 2.5 wt.% ruthenium loading and a catalyst usage of 1.5 g, 20% glucose solution at 130 °C, reaction pressure of 4.0 MPa, and a stirring speed of 600 rpm for 3 h. These conditions achieved a high glucose conversion rate of 99.68% and a sorbitol selectivity of 93.04%. Reaction kinetics testing proved that the hydrogenation of glucose catalyzed by Ru/ASMA@AC was a first-order reaction, with a reaction activation energy of 73.04 kJ/mol. Furthermore, the catalytic performance of the Ru/ASMA@AC and Ru/AC catalysts for glucose hydrogenation were compared and characterized by various detection methods. The Ru/ASMA@AC catalyst exhibited excellent stability after five cycles, whereas the traditional Ru/AC catalyst suffered from a 10% decrease in sorbitol yield after three cycles. These results suggest that the Ru/ASMA@AC catalyst is a more promising candidate for high-concentration glucose hydrogenation due to its high catalytic performance and superior stability.
Tension stress in steel-concrete composite is widely observed in engineering design. Based on an experimental program on tension performance of three square concrete-filled tubes (SCFT), the tension ...theory of SCFT is proposed using a mechanics-based approach. The tension stiffening effect, the confining strengthening effect and the confining stiffening effect, observed in tests of SCFTs are included in the developed tension theory model. Subsequently, simplified constitutive models of steel and concrete are proposed for the axial tension performance of SCFT. Based on the MSC.MARC software, a special fiber beam-column element is proposed to include the confining effect of SCFTs under tension and verified. The proposed analytical theory, effective formulas, and equivalent constitutive laws are extensively verified against three available tests reported in the literature on both global level (e.g., load-displacement curves) and strain level. The experimental verification proves the accuracy of the proposed theory and formulations in simulating the performance of SCFT members under tension with the capability to accurately predict the tensile strength and stiffness enhancements and realistically simulate the fractal cracking phenomenon.
(1) Background: A balanced life is related to good health in young people, one of the groups most affected by confinement and social distancing measures during the COVID-19 pandemic. This study aims ...to explore the occupational balance of young adults during home confinement and its association with different sociodemographic factors. (2) Methods: A cross-sectional study was designed, and an online survey was disseminated to collect sociodemographic and occupational balance data, using the Occupational Balance Questionnaire (OBQ). The statistical analysis was performed using the SPSS statistical software package version 24.0. (3) Results: 965 young adults between 18 and 30 years old participated in the study. A predictive model showed that the main predictors of a lower occupational balance were a negative self-perception (β= 0.377; p = <0.0001), student status (β = 0.521; p = 0.001), not receiving enough information (β = 0.951; p = 0.001) and long periods of quarantine (β = 0.036; p = 0.007). (4) Conclusions: Considering people’s occupational health and related factors could lessen many of the psychosocial consequences of isolation and contribute to the well-being of young people.
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A series of fracture geometries of an artificially tensile fractured sandstone, measured during the hydraulic tests at increasing confine stresses, were adopted to build 3D fracture ...models. At each stress level, four groups of flow simulations with increasing injection flow rates were conducted, to examine how voids and contact alterations due to stress changes affect the flow characteristics within the fracture. The results show that the simulated normalized apparent transmissivity matched well with that measured from hydraulic tests, and both them decreases nonlinearly with increasing confine stress. The alterations in fracture geometries due to stress changes increase the heterogeneities of flow characteristics in 3D fractures, including flow rates, streamlines, water pressure. The streamlines become more channeled with observable tortuosity under high stress. The stress induced increase in contact and the occurrence of eddy flow enhance the non-linearity of pressure drop. The decrease of both apertures and sharp geometries under high stress reduces the range of eddy flows, which delays the occurrence of significant inertial effects and results in the increase of critical Reynolds numbers. These features are demonstrated well using an idealized 3D representative geometric including both the asperity contacts and voids.
As far as I can see, there is a real place that actualise, better than any other one, the double nature meant by the term 'border' - a sort of oxymoron, in terms of etymology: the trench. Similarly, ...it does exist an author who experienced, comprehended and cried that duplicity out: Giuseppe Ungaretti. Forced to live a dramatic experience within the boundary line, he succeeded in crossing the historical, political, ideological and existential boundary between himself and 'the other'. Furthermore, he did it without any constriction, as it was a 'natural' and unavoidable 'step', as a result of his human nature. Crossing the boundary inevitably meant the reformulation of the relationship with 'the other', where 'the other' means person, landscape and 'absolute'; likewise, this led the author to a deep reconsideration of the current linguistic and literary conventions. The traditional poetical language had proved to be completely inadequate in front of the dramatic condition of the modern man. In order to demonstrate the relevant role of the border in this evolution, it will be made a comparison between Ungaretti's experience and the one of other two Italian intellectuals. Those, despite of living similar – even though not identical – war experiences, didn't come to the same conclusion as our poet, neither ideological nor literary. Beyond the natural differences in their personality and artistic sensitivity, as far as Giani Stuparich is concerned, it is another real border to make the difference: the boundary line between Italy and Austro-Hungarian Empire. Despite belonging to 'there', he felt himself 'here'. On the contrary, talking about Carlo Emilio Gadda, what appears relevant is the role he played in the Army during the war: he was an officer and he didn't live in the trenches. That seems to have influenced his conception of the war and to have prevented him from 'crossing the boundary'.
Rationally designing sulfur host which allows fast redox kinetics and can confine soluble polysulfides (PSs) is crucial for high‐performance lithium‐sulfur batteries (LSBs). Herein, N‐doped hollow ...porous carbon spheres (NHPCS) with large specific surface area (1526 m2 g−1) and strong interaction toward PSs were fabricated by a template method and applied as an efficient sulfur host. Benefiting from the hollow porous structure and function design, the NHPCS shows a high sulfur loading of 78.9 wt.% and improved adsorption capacity for PSs. Finally, the LSBs with the S@NHPCS as the cathode exhibit higher initial capacity of 1263 mAh g−1 at 0.2 C and lower decay rate (0.07 % per cycle) than S@CNT after 500 cycles at 1 C.
Phosphite-based fungicides are increasingly used to control fungi-like plant pathogens from the Oomycetes group. A rapid, precise, and cost-effective suppressed conductivity high performance ion ...chromatography (HPIC) method was developed to assess the concentrations of soluble phosphites (Phi) and phosphates (Pi) in plant samples. This technique was used to determine the amount of Phi and Pi in leaves and tubers of potato plants following foliar applications of the Phi-based fungicide Confine™. High amounts of Phi were determined in both leaves and tubers indicating that potato plants efficiently uptake and translocate the fungicide. The number of applications of Confine™ and its concentration were found to be directly proportional with the amount of Phi detected in potato plants and inversely proportional with the development of Phytophthora infestans (Mont.) de Bary in these plants. Levels of Phi comparable to those determined in plants were found to strongly inhibit the growth of P. infestans in vitro. The simultaneous estimation of the in planta Phi concentration and of the sensitivity of P. infestans to Phi represent the most comprehensive approach of assessing the efficacy of Phi-based fungicides in controlling late blight development in potatoes.
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•We describe a method for estimating phosphites (Phi) in plants by ion chromatography.•This technique was used to determine the amount of Phi in potato plants.•Potato plants efficiently uptake and translocate phosphite-based fungicides.•Several applications of Phi are needed to suppress Phytophthora infestans' development in potatoes.•The amount of Phi needed to inhibit P. infestans' growth was tested in vitro.
This paper presents an experimental study on the mechanical behavior, particularly the tensile stiffness, of square concrete-filled steel tubes (SCFTs) under axial tension, from both the ...force/displacement-level and strain-level perspectives. A group of SCFT and hollow tube specimens are tested with extensive data of the steel tube strains measured. From the force/displacement-level perspective, it is found that the tensile stiffness of SCFTs is 31.8% higher than that of hollow tubes on average. It is proposed that tensile stiffness enhancement is a combined result of the confine-stiffening effect and tension-stiffening effect. The confine-stiffening effect is because of the biaxial tensile stress state of the steel tube due to the concrete-to-steel tube confinement of SCFTs. From the strain-level perspective, the existence of the concrete-to-steel tube confinement is proved by comparing the measured transverse-to-longitudinal strain ratio of the steel tube between SCFT and hollow tube specimens. Besides, the evidence for the tension-stiffening effect in SCFTs is also provided by the non-uniformly distributed longitudinal steel strain of the steel tube. In addition, the fractal cracking phenomenon is experimentally observed and quantitatively measured, indicating the interaction of the concrete-to-steel tube confinement and tension-stiffening effect. It is concluded that the tensile stiffness of SCFTs will be underestimated if the SCFTs under tension are simply treated as equal to the hollow tubes by neglecting the concrete-to-steel tube confinement and tension-stiffening effect; this underestimation may cause non-conservative inaccuracies in calculating the component internal forces, structural natural frequencies, and seismic effects in the design and analysis of structures.
•The tensile stiffness of SCFTs is 31.8% higher than that of hollow tubes.•The confine-stiffening effect reveals the mechanism of this stiffness enhancement.•The transverse-to-longitudinal strain ratio proves the confine-stiffening effect.•The fractal cracking phenomenon is observed and quantitatively studied.
Balancing the large surface area and high crystallinity of heterogeneous metal oxide catalysts is quite tricky. They are usually needed together to get both a large amount of active catalytic sites ...and high thermal stability. In this paper, the preparation of porous sulfate ZrO2 as solid acid catalysts is reported. The monolithic porous SiO2 created confined spaces in which porous ZrO2 was synthesized in it. The ZrO2 has excellent porous structure in which the specific surface area reaches 277 m2 g–1 and has good crystallinity. At the same time, they have high acid site loading (2.57 mmol g–1) upon sulfation. The sulfonic ZrO2 exhibits excellent catalytic performance when considering the dehydration of 5-HMF from d-fructose. The yield of 5-HMF is 87% for 60 min at 120 °C. Thus, this solid acid catalyst was a potential candidate for heterogeneous catalysis and biomass quick conversion.
In this research, complex emitting layers (EML) were fabricated using TCTA doping hole-transport material in the front half of a bipolar 26DCzPPy as well as PPT doping electron-transport material in ...the back half of 26DCzPPy. Blue dopant FIrpic was also mixed inside the complex emitting layer to produce a highly efficient blue phosphorescent organic light emitting diode (OLED). The hole and electron injection and carrier recombination rate were effectively increased. The fabricated complex emitting layers exhibited current efficiency of 42cd/A and power efficiency of 30lm/W when the luminance was 1000cd/m2, driving voltage was 4.4V, and current density was 2.4mA/cm2. A white OLED component was then manufactured by doping red dopant Os(bpftz)2(PPh2Me)2 (Os) in proper locations. When the Os dopant was doped in between the complex emitting layers, excitons were effectively confined within, increasing the recombination rate and therefore reducing the color shift. The resulting Commission Internationale de L’Eclairage (CIE) coordinates shifted from 4 to 10V is (Δx=−0.04, Δy=+0.01). The component had a current efficiency of 35.7cd/A, a power efficiency of 24lm/W, driving voltage of 4.6V and a CIEx,y of (0.31,0.35) at a luminance of 1000cd/m2, with a maximum luminance of 15,600cd/m2 at 10V. Attaching an outcoupling enhancement film was applied to increase the luminance efficiency to 30lm/W.
•Used the complex double emitting layers.•Respectively doped hole and electron transport material in the bipolar host.•Electrons and holes are effectively confined within EMLs to produce excitons.
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