12 research outputs found

    Coenzyme Q10 and Its Therapeutic Potencies Against COVID-19 and Other Similar Infections: A Molecular Review

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    Purpose: New lethal coronavirus disease 2019 (COVID-19), currently, has been converted to a disastrous pandemic worldwide. As there has been found no definitive treatment for the infection in this review we focused on molecular aspects of coenzyme Q10 (CoQ10) and possible therapeutic potencies of CoQ10 against COVID-19 and similar infections. Methods: This is a narrative review in which we used some authentic resources including PubMed, ISI, Scopus, Science Direct, Cochrane, and some preprint databases, the molecular aspects of CoQ10 effects, regarding to the COVID-19 pathogenesis, have been analyzed and discussed. Results: CoQ10 is an essential cofactor in the electron transport chain of the phosphorylative oxidation system. It is a powerful lipophilic antioxidant, anti-apoptotic, immunomodulatory and anti-inflammatory supplement which has been tested for the management and prevention of a variety of diseases particularly diseases with inflammatory pathogenesis. CoQ10 is a strong anti-inflammatory agent which can reduce tumor necrosis factor-α (TNF-α), interleukin (IL)- 6, C-reactive protein (CRP), and other inflammatory cytokines. The cardio-protective role of CoQ10 in improving viral myocarditis and drug induced cardiotoxicity has been determined in different studies. CoQ10 could also improve the interference in the RAS system caused by COVID-19 through exerting anti-Angiotensin II effects and decreasing oxidative stress. CoQ10 passes easily through blood–brain barrier (BBB). As a neuroprotective agent CoQ10 can reduce oxidative stress and modulate the immunologic reactions. These properties may help to reduce CNS inflammation and prevent BBB damage and neuronal apoptosis in COVID-19 patients. Conclusion: CoQ10 supplementation may prevent the COVID-19-induced morbidities with a potential protective role against the deleterious consequences of the disease, further clinical evaluations are encouraged

    Brittle fracture prediction of key-hole notched specimens by means of J-integral expression

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    The main goal of the present research is to check if J-integral criterion is capable of predicting the onset of brittle fracture in key-hole notched isostatic poly-granular graphite plates. In this way, this article provides the prediction of fracture loads in several key-hole notched rectangular graphite specimens with five different notch tip radii subjected to pure mode I loading condition, which has been previously reported in the literature by Lazzarin et al. (2013). The fracture load predictions for five dimensional cases were obtained through the J-integral calculations. It is revealed that the J-integral criterion is capable of predicting well the fracture loads of graphite key-hole notched specimens, independent of the size of key-hole notch

    Application of EMC-J criterion to fracture prediction of U-notched polymeric specimens with nonlinear behaviour

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    The main purpose of the present research paper is to investigate applicability of a new energy‐based failure prediction model, called EMC‐J criterion, to predict the critical loads of U‐notched polymeric samples having a ductile behaviour and loaded under symmetric 3‐point bending. The evaluated polymeric single edge notch bending samples containing U‐notches failed by considerable plastic deformations around the notch border, making it inappropriate to directly use classic linear elastic‐based formulations. Due to the elastic‐plastic behaviour of the tested polymeric material, EMC‐J criterion is applied to avoid using complex and extremely time‐consuming nonlinear analysis for failure load predictions. Finally, it is shown that EMC‐J criterion can provide a good consistency between the experimental and theoretical results with an average discrepancy of about 10%

    Monitoring and Characterizing the Finger Patterns Developed by Miscible Displacement in Fractured Heavy Oil Systems

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    This work concerns experimentally quantifying finger behavior during miscible displacements in fractured porous media. A series of miscible tests were performed on five-spot fractured micromodels which were initially saturated with heavy crude oil, and the developed finger patterns were quantified using an image analysis technique. The results revealed that the numbers of macro fingers formed is well correlated with the square root of dimensionless time, while the rate of finger initiation is independent of fracture characteristics. The level of bypassed oil linearly decreases with dimensionless distance traveled by front precisely. The transient fractal dimension behavior experiences a minimum due to advancement of front in fractures, and subsequently, growth of side fingers. Variable transient behavior of fingers fractal dimension may suggest that miscible injection in fractured media does not obey fractal theory. Therefore, more care is required for upscaling of miscible displacements in fractured media using fractal characteristics

    Fracture assessment of U-notched graphite specimens by means of cohesive zone model

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    Various types of graphite have gained interest in many industrial applications due to their high strength and excellent heat tolerance. However, due to the brittle nature of this material, presence of stress concentrators such as notches and geometrical discontinuities considerably re-duces the overall loading bearing of the graphite components. Here we evaluate the applicability of the Cohesive Zone Model (CZM) for the assessment of the fracture strength of experimentally tested U-notched specimens subject to mode I loading. The fracture loads of U-notched components with different notch tip radii can be predicted with an average discrepancy of ±7%

    Sustainable Pricing-Production-Workforce-Routing Problem for Perishable Products by Considering Demand Uncertainty; A Case Study from the Dairy Industry

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    International audienceThe production routing problem seeks to simultaneously optimize production, routing, and inventory decisions for the plant and the suppliers. In this article an integrated multi-objective sustainable pricing-production-workforce-routing problem is presented for perishable products. Total profit, workforce planning, and vehicle fuel consumption are considered as objective functions due to the importance of operational performance, social, and environmental concerns. The application of the proposed approach is investigated using real case data from a dairy product supply chain. Furthermore, a new solution approach, called Fuzzy Domination Self-Learning Non-Dominated Sorting Algorithm (FDSL-NSGA-II), is developed to solve the problem. The results show that the Pareto solutions of FDSL-NSGA-II outperform those of the classic NSGA-II. Moreover, the findings show that the proposed model can create a surpassing tradeoff between the various aspects of a supply chain, including production, distribution, and workforce planning. In addition, it concurrently optimizes the selling price and protects the environment from the negative impacts of greenhouse gas emissions (GHGs). A comprehensive analysis of the results reveals several managerial insights for decision makers in the logistics industry

    A strain-based criterion for failure load prediction of steel/CFRP double strap joints

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    One of the most effective approaches to improve the strength of steel structures is using the carbon fiber reinforced polymer (CFRP) as externally-bonded sheets. In this paper, a strain-based failure criterion, namely the critical normal strain (CNS) is employed to predict the failure load of adhesively bonded double strap joints which are made of CFRP and steel plates. According to this approach, the adhesive joint fails when the normal strain along the adhesive mid-line attains a critical value at a critical distance. This work is based on a two-dimensional linear elastic finite element analysis. Failure load capacities are estimated theoretically for steel/CFRP double strap joints with different bonding lengths. The predicted values of failure loads are compared with the experimental data reported in literature. It is shown that a good consistency exists between the experimental failure loads and the theoretical predictions based on the new strain-based criterion.submittedVersionThis is a submitted manuscript of an article published by Elsevier Ltd in Composite structures, 18 August 2018

    A strain-based criterion for failure load prediction of steel/CFRP double strap joints

    No full text
    One of the most effective approaches to improve the strength of steel structures is using the carbon fiber reinforced polymer (CFRP) as externally-bonded sheets. In this paper, a strain-based failure criterion, namely the critical normal strain (CNS) is employed to predict the failure load of adhesively bonded double strap joints which are made of CFRP and steel plates. According to this approach, the adhesive joint fails when the normal strain along the adhesive mid-line attains a critical value at a critical distance. This work is based on a two-dimensional linear elastic finite element analysis. Failure load capacities are estimated theoretically for steel/CFRP double strap joints with different bonding lengths. The predicted values of failure loads are compared with the experimental data reported in literature. It is shown that a good consistency exists between the experimental failure loads and the theoretical predictions based on the new strain-based criterion

    Energy-based ductile failure predictions in cracked friction-stir welded joints

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    This research aims to study the fracture behaviour in dissimilar aluminum alloys adjoined by friction stir welding (FSW). In this way, experimental data dealing with this topic was taken from the recent literature. In those experimental results, two metal sheets made of Al 7075-T6 and Al 6061-T6 were adjoined together by FSW in the form of well-known specimen, namely the cracked semi-circular bend (CSCB) and then they are tested under mixed mode I/II loading condition. Due to the fact that substantial plastic behavior exist in the welded material and consequently significant plastic deformations were observed around the crack tip, failure prediction of the mentioned specimens needs failure prediction models in the basis of the elastic-plastic fracture mechanics which can be realized as sophisticated operations inquiring long time. In this way, the Equivalent Material Concept (EMC) is utilized in this research and then coupled with two eligible energy-based criteria, namely the averaged strain energy density (ASED) and J-integral criteria. Thus, the critical failure load of the welded samples is predicted. Comparison between the empirical data and theoretical predictions from energy-based evaluations showed that this model has enough capability in estimating the critical failure load of the CSCB samples
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