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Author(s):  
Tricia Bogossian ◽  

In the wake of this pandemic, the Government took several preventive measures to contain its spread, mainly ensuring physical and social distance. Some of the initial measures included the partial blocking of commercial and social activities, closing of all educational institutions, suspension of all community services and political meetings, among others. Some of the initial measures also included: recommended and, in some cases, mandatory hand washing; deny students studying in China to return home; voluntary quarantine; mandatory institutional quarantine at own expense; suspension of public and private transport; and imprisonment for non-compliance with the measures


2021 ◽  
Author(s):  
Aleksey Platonov ◽  
A. Popov ◽  
Svetlana Snegireva ◽  
Ekaterina Kantieva

Fires have a significant impact on the structure and physical and mechanical properties of wood. The degree of this effect depends on the type of fire, its intensity and the duration of exposure to high temperature. The greatest impact on the wood occurs with a strong grassroots and general top fire. Gorenje fire is characterized by a high intensity of burning of forest floor and undergrowth, as well as the crown of trees. The effect of the high temperature of the fire on the tree trunk is different. As a result of the destruction of wood, there is a partial blocking of hydroxyl groups in the cellulose molecules and leads to a decrease in the hygroscopicity limit of wood. Of great practical interest is the change in the hygroscopicity of wood damaged by fire. The aim of this study is to determine the changes in the hygroscopicity of the core wood of Scots pine (Pinus sylvestris L.)after damage by a strong grassroots and general high-level fire. The studies were carried out on wood growing on the territory of the UOL in the Voronezh region, on samples of pine core wood cut from the clump, middle and apex parts of the trunk. It was experimentally established that the greatest decrease in the hygroscopicity of pine core wood occurred in the left part of the trunk, and the smallest in the middle part, after fire damage.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 635
Author(s):  
Rasmus Jonsson ◽  
Phuoc Hoang Ho ◽  
Aiyong Wang ◽  
Magnus Skoglundh ◽  
Louise Olsson

Hydrocarbon traps can be used to bridge the temperature gap from the cold start of a vehicle until the exhaust after-treatment catalyst has reached its operating temperature. In this work, we investigate the effect of zeolite structure (ZSM-5, BEA, SSZ-13) and the effect of La addition to H-BEA and H-ZSM-5 on the hydrocarbon storage capacity by temperature-programmed desorption and DRIFT spectroscopy. The results show that the presence of La has a significant effect on the adsorption characteristics of toluene on the BEA-supported La materials. A low loading of La onto zeolite BEA (2% La-BEA) improves not only the toluene adsorption capacity but also the retention of toluene. However, a higher loading of La results in a decrease in the adsorbed amount of toluene, which likely is due to partial blocking of the pore of the support. High loadings of La in BEA result in a contraction of the unit cell of the zeolite as evidenced by XRD. A synergetic effect of having simultaneously different types of hydrocarbons (toluene, propene, and propane) in the feed is found for samples containing ZSM-5, where the desorption temperature of propane increases, and the quantity that desorbed increases by a factor of four. This is found to be due to the interaction between toluene and propane inside the structure of the zeolite.


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 399
Author(s):  
Ana C. Barros ◽  
Ana Pereira ◽  
Luis F. Melo ◽  
Juliana P. S. Sousa

Reverse osmosis (RO) depends on biocidal agents to control the operating costs associated to biofouling, although this implies the discharge of undesired chemicals into the aquatic environment. Therefore, a system providing pre-treated water free of biocides arises as an interesting solution to minimize the discharge of chemicals while enhancing RO filtration performance by inactivating bacteria that could form biofilms on the membrane system. This work proposes a pretreatment approach based on the immobilization of an industrially used antimicrobial agent (benzalkonium chloride—BAC) into millimetric aluminum oxide particles with prior surface activation with DA—dopamine. The antimicrobial efficacy of the functionalized particles was assessed against Escherichia coli planktonic cells through culturability and cell membrane integrity analysis. The results showed total inactivation of bacterial cells within five min for the highest particle concentration and 100% of cell membrane damage after 15 min for all concentrations. When reusing the same particles, a higher contact time was needed to reach the total inactivation, possibly due to partial blocking of immobilized biocide by dead bacteria adhering to the particles and to the residual leaching of biocide. The overall results support the use of Al2O3-DA-BAC particles as antimicrobial agents for sustainable biocidal applications in continuous water treatment systems.


Author(s):  
Stepan Melnyk

Business conditions, which are characterized by high turbulence of changes in the operating environment for all enterprises, have become significantly more complicated within the last year, which was catalyzed by the latest pandemic COVID19. In order to stabilize the situation and save the lives of citizens, a number of restrictions were applied, which also affected business activities. It is wrong to consider only this factor as the main one that affected the financial security of industrial enterprises. Other external factors for the formation of adequate protective redoubts should not be ignored. In addition, the specifics of the functioning of each individual enterprise, which is characterized by the excellent influence of macro-, meso- and macro-level factors, need attention. The aim of the study was to form a methodological approach to determining the impact of external factors on the management of financial security of industrial enterprises. To form a methodological approach to determining the impact of external factors on the management of financial security of industrial enterprises used methods: multi-criteria choice of alternatives based on a fuzzy relationship of preference - to determine the priority of the impact of individual factors on financial security; abstract-logical - for theoretical generalizations and conclusions of the study. External factors that most significantly affect the financial security of industrial enterprises include: the onset of the financial crisis and the rapid devaluation of the national currency; unpredictable political events; Military conflicts and terrorist acts; natural disasters and catastrophes (including the COVID19 pandemic); the emergence of a monopoly structure in the market; raider capture; application of trade and financial sanctions; full or partial blocking of bank accounts. The systematization of external factors influencing the financial security management of industrial enterprises has been carried out, which involves the application of the method of multi-criteria selection of alternatives based on a fuzzy ratio of advantages, which allowed to justify priority areas for improving financial security management. The obtained results create the necessary analytical basis for the improvement of the management system based on the introduction of adaptive and antisipative types of financial security management of industrial enterprises.


Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1202 ◽  
Author(s):  
Wiersma ◽  
van Marion ◽  
Wüst ◽  
Houtkooper ◽  
Zhang ◽  
...  

Atrial fibrillation (AF), the most common progressive tachyarrhythmia, results in structural remodeling which impairs electrical activation of the atria, rendering them increasingly permissive to the arrhythmia. Previously, we reported on endoplasmic reticulum stress and NAD+ depletion in AF, suggesting a role for mitochondrial dysfunction in AF progression. Here, we examined mitochondrial function in experimental model systems for AF (tachypaced HL-1 atrial cardiomyocytes and Drosophila melanogaster) and validated findings in clinical AF. Tachypacing of HL-1 cardiomyocytes progressively induces mitochondrial dysfunction, evidenced by impairment of mitochondrial Ca2+-handling, upregulation of mitochondrial stress chaperones and a decrease in the mitochondrial membrane potential, respiration and ATP production. Atrial biopsies from AF patients display mitochondrial dysfunction, evidenced by aberrant ATP levels, upregulation of a mitochondrial stress chaperone and fragmentation of the mitochondrial network. The pathophysiological role of mitochondrial dysfunction is substantiated by the attenuation of AF remodeling by preventing an increased mitochondrial Ca2+-influx through partial blocking or downregulation of the mitochondrial calcium uniporter, and by SS31, a compound that improves bioenergetics in mitochondria. Together, these results show that conservation of the mitochondrial function protects against tachypacing-induced cardiomyocyte remodeling and identify this organelle as a potential novel therapeutic target.


Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2057 ◽  
Author(s):  
Arias-Serrano ◽  
Xie ◽  
Aguirre ◽  
Tobaldi ◽  
Sarabando ◽  
...  

Zinc oxide (ZnO) has being recognised as a potentially interesting thermoelectric material, allowing flexible tuning of the electrical properties by donor doping. This work focuses on the assessment of tantalum doping effects on the relevant structural, microstructural, optical and thermoelectric properties of ZnO. Processing of the samples with a nominal composition Zn1−xTaxO by conventional solid-state route results in limited solubility of Ta in the wurtzite structure. Electronic doping is accompanied by the formation of other defects and dislocations as a compensation mechanism and simultaneous segregation of ZnTa2O6 at the grain boundaries. Highly defective structure and partial blocking of the grain boundaries suppress the electrical transport, while the evolution of Seebeck coefficient and band gap suggest that the charge carrier concentration continuously increases from x = 0 to 0.008. Thermal conductivity is almost not affected by the tantalum content. The highest ZT~0.07 at 1175 K observed for Zn0.998Ta0.002O is mainly provided by high Seebeck coefficient (−464 V/K) along with a moderate electrical conductivity of ~13 S/cm. The results suggest that tantalum may represent a suitable dopant for thermoelectric zinc oxide, but this requires the application of specific processing methods and compositional design to enhance the solubility of Ta in wurtzite lattice.


Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 203 ◽  
Author(s):  
Almudena Parejas ◽  
Daniel Cosano ◽  
Jesús Hidalgo-Carrillo ◽  
José Ruiz ◽  
Alberto Marinas ◽  
...  

Aldol condensation of furfural and acetone (an important initial step to obtain diesel from biomass) was studied over MgAl mixed oxides. The influence of the utilization of microwaves and/or a surfactant (Pluronic 123) during the synthesis as well as the use of water (either pre-hydrating the solids before catalytic studies or in water/toluene mixtures as the reaction medium) is discussed. The combined use of Pluronic 123 and microwaves led to solids with bigger pore sizes, exhibiting lower basicity and higher acidity than the conventional synthetic method, thus resulting in an increase in the yield of the desired product of condensation, comprising two molecules of furfural and one of acetone (F2Ac). As for the influence of water, re-hydration of the mixed oxides was detrimental to activity, probably as a result of the partial blocking (solvation) of active sites. On the contrary, the increase in water percentage in the reaction medium resulted in higher conversions, though selectivity to F2Ac decreased. The weakening of the C=O bond of furfural in the presence of water as well as the higher solubility of the first condensation product (FAc) in toluene, as compared to water, could account for that. A 44.5% yield of F2Ac (66% conversion) after 16 h was obtained with the most active solid, which maintained the activity for three consecutive reactions.


2018 ◽  
Vol 33 (3) ◽  
pp. 348-366
Author(s):  
Paul Ezhilchelvan ◽  
Isi Mitrani

A cloud provider hosts virtual machines (VMs) of different types, with different resource requirements. There are bounds on the total amounts of each kind of resource that are available. Requests arrive in batches of different sizes. Under the ‘complete blocking’ policy, a request is accepted only if all the VMs in its batch can be accommodated. The ‘partial blocking’ policy would accept a request if there is room for at least one of the VMs in the batch. Blocked requests are lost, with an associated loss of revenue. The trade-offs between costs and benefits are evaluated by means of appropriate models, for which novel solutions based on fixed-point iterations are proposed. The applicability of those solutions is extended, by means of simplifications, to very large-scale systems. Numerical examples and comparisons with simulations are presented.


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