A large lateral shearing distance of parallel beam-splitting prism is often needed in laser modulation and polarization interference. In this letter, we present an optimized design of parallel beam-splitting prism and...A large lateral shearing distance of parallel beam-splitting prism is often needed in laser modulation and polarization interference. In this letter, we present an optimized design of parallel beam-splitting prism and list some different cases in detail. The optimized design widens the use range of parallel beam-splitting prism. At the wavelength of 632.8 nm, the law that the enlargement ratio changes with the refractive index and the apex angle is verified.展开更多
A comparative analysis was performed on poly(lactic acid)(PLA),poly(caprolactone)(PCL),basalt fiber(BF)composites produced using two distinct approaches:direct blending and masterbatching.The limitations of PLA-BF com...A comparative analysis was performed on poly(lactic acid)(PLA),poly(caprolactone)(PCL),basalt fiber(BF)composites produced using two distinct approaches:direct blending and masterbatching.The limitations of PLA-BF composites with regard to distribution and adhesion are well-documented,as are chemical treatment methods(addition of compatibilisers,surface treatments,silanization).This work aimed to study an industrially relevant potential solution of utilising a PCL-BF masterbatch,prepared as a 50/50 wt.%blend using planetary roller extrusion(PEX)to both improve the distribution and homogeneity of the fibers as well as provide a secondary adhesion site to facilitate improved mechanical properties of the final PLA-PCL-BF composite.The resultant materials were injection moulded to prepare ISO standard test specimens and tested on the basis of their physical properties via tensile testing,impact strength testing,flexural analysis,Fourier transforminfrared spectroscopy and water absorption capability.The results displayed that the incorporation of PCL and BF led to an increase in ductility of the composite materials,allowing for improvements in the inherent brittleness of virgin PLA.Major increases in the impact strength were achieved with the utilisation of a 25% PCL/BF masterbatch,allowing for a greater than 50%increase.As an overall observation,the use of a masterbatching process,opposed to direct blending of the constituent materials allows for a greater consistency of composite to be achieved at the expense of increased gains.展开更多
Background: Erythrodermic psoriasis (EP) is a rare, severe variant of psoriasis characterized by widespread erythema, scaling, and systemic complications. Despite advances in systemic treatments, the management of EP ...Background: Erythrodermic psoriasis (EP) is a rare, severe variant of psoriasis characterized by widespread erythema, scaling, and systemic complications. Despite advances in systemic treatments, the management of EP remains challenging, particularly in patients with comorbidities or contraindications to standard therapies. Objectives: To evaluate the effectiveness of ozonated water as an adjunctive treatment for EP, delivered using a patented robotic therapy system designed for hygiene and infection prevention in non-self-sufficient patients. Methods: We report the case of a 90-year-old male patient with acute EP who received daily skin treatments with ozonated water in conjunction with supportive care, including rehydration and antibiotics. The intervention was facilitated by the robotic system “COPERNICO Surveillance & Prevention,” which ensured standardized hygiene practices and clinical documentation. Results: Within one week of treatment, the patient showed complete desquamation of necrotic skin, resolution of erythema, and significant metabolic recovery. Fever subsided, renal function improved, and the patient was discharged in stable condition. Follow-up confirmed sustained clinical improvement, and no adverse events were reported. Conclusions: Ozonated water demonstrated efficacy in alleviating the dermatological and systemic manifestations of EP in a high-risk elderly patient. This case highlights the potential of ozone therapy as a safe, cost-effective adjunctive treatment for EP and underscores the utility of robotic systems in managing complex dermatological conditions. Further research is warranted to validate these findings in larger cohorts.展开更多
Recently,numerous estimation issues have been solved due to the developments in data-driven artificial neural networks(ANN)and graph neural networks(GNN).The primary limitation of previous methodologies has been the d...Recently,numerous estimation issues have been solved due to the developments in data-driven artificial neural networks(ANN)and graph neural networks(GNN).The primary limitation of previous methodologies has been the dependence on data that can be structured in a grid format.However,physiological recordings often exhibit irregular and unordered patterns,posing a significant challenge in conceptualising them as matrices.As a result,GNNs which comprise interactive nodes connected by edges whose weights are defined by anatomical junctions or temporal relationships have received a lot of consideration by leveraging implicit data that exists in a biological system.Additionally,our study incorporates a structural GNN to effectively differentiate between different degrees of infection in both the left and right hemispheres of the brain.Subsequently,demographic data are included,and a multi-task learning architecture is devised,integrating classification and regression tasks.The trials used an authentic dataset,including 800 brain x-ray pictures,consisting of 560 instances classified as moderate cases and 240 instances classified as severe cases.Based on empirical evidence,our methodology demonstrates superior performance in classification,surpassing other comparison methods with a notable achievement of 92.27%in terms of area under the curve as well as a correlation coefficient of 0.62.展开更多
Estimating the oil-water temperatures in flowlines is challenging especially in deepwater and ultra-deepwater offshore applications where issues of flow assurance and dramatic heat transfer are likely to occur due to ...Estimating the oil-water temperatures in flowlines is challenging especially in deepwater and ultra-deepwater offshore applications where issues of flow assurance and dramatic heat transfer are likely to occur due to the temperature difference between the fluids and the surroundings. Heat transfer analysis is very important for the prediction and prevention of deposits in oil and water flowlines, which could impede the flow and give rise to huge financial losses. Therefore, a 3D mathematical model of oil-water Newtonian flow under non-isothermal conditions is established to explore the complex mechanisms of the two-phase oil-water transportation and heat transfer in different flowline inclinations. In this work, a non-isothermal two-phase flow model is first modified and then implemented in the InterFoam solver by introducing the energy equation using OpenFOAM® code. The Low Reynolds Number (LRN) k-ε turbulence model is utilized to resolve the turbulence phenomena within the oil and water mixtures. The flow patterns and the local heat transfer coefficients (HTC) for two-phase oil-water flow at different flowlines inclinations (0°, +4°, +7°) are validated by the experimental literature results and the relative errors are also compared. Global sensitivity analysis is then conducted to determine the effect of the different parameters on the performance of the produced two-phase hydrocarbon systems for effective subsea fluid transportation. Thereafter, HTC and flow patterns for oil-water flows at downward inclinations of 4°, and 7° can be predicted by the models. The velocity distribution, pressure gradient, liquid holdup, and temperature variation at the flowline cross-sections are simulated and analyzed in detail. Consequently, the numerical model can be generally applied to compute the global properties of the fluid and other operating parameters that are beneficial in the management of two-phase oil-water transportation.展开更多
The past literature on the use of vegetable oils as fuel in diesel engine revealed that utilizing vegetable oil fuels in diesel engines may require property changes in the oil or perhaps, some minor engine modificatio...The past literature on the use of vegetable oils as fuel in diesel engine revealed that utilizing vegetable oil fuels in diesel engines may require property changes in the oil or perhaps, some minor engine modifications or operating changes. This study was conducted to search for the effect of atmospheric oxygen on the puffing and bursting phenomena that occur during vegetable oils droplet vaporization process in their use as fuel in diesel engine. The fiber-suspended droplet technique was used, and the normalized square droplet diameter as well as the temperature evolution vicinity the droplet was analyzed. The results show that puffing and bursting phenomena highly depend on oxygen. In presence of atmospheric oxygen, there is an increase of the puffing and bursting intensity and therefore the evaporation rate of the vegetable oil droplets, but in an inert environment or when the environment is oxygen-depleted puffing and bursting phenomena disappearing and make place of a series of explosions with lower magnitude. The lack of oxygen reduces the thermal degradation, polymerization and oxidation reactions and consequently the vaporization rate of vegetable oils droplets;and could therefore lead to the formation of deposits in the form of polymers. This is unsuitable for their use as a fuel in diesel engines. It can also be concluded that atmospheric oxygen has some positive effects on engine performance and emissions when operating with vegetable oil. These results help to address the challenge for the use of alternative fuels such as non-edible vegetable oils.展开更多
The aim of this paper is to seek the numerical solution of a class of variable order fractional integral-differential equation in terms of Bernstein polynomials.The fractional derivative is described in the Caputo sen...The aim of this paper is to seek the numerical solution of a class of variable order fractional integral-differential equation in terms of Bernstein polynomials.The fractional derivative is described in the Caputo sense.Four kinds of operational matrixes of Bernstein polynomials are introduced and are utilized to reduce the initial equation to the solution of algebraic equations after dispersing the variable.By solving the algebraic equations,the numerical solutions are acquired.The method in general is easy to implement and yields good results.Numerical examples are provided to demonstrate the validity and applicability of the method.展开更多
The mechanical behavior of geomaterials is studied using an XFEM (extended finite element method). Usually, the modeling of such heterogeneous material is performed either through an analytical homogenization approa...The mechanical behavior of geomaterials is studied using an XFEM (extended finite element method). Usually, the modeling of such heterogeneous material is performed either through an analytical homogenization approach, or numerically, especially for complex microstructures. For comparison, the effective properties are obtained using a classical finite element analysis (through the so-called unit cell method) and an analytical homogenization approach. The use of XFEM proposed here retains the accuracy oftbe classical finite element approach, allowing one to use meshes that do not necessarily match the physical boundaries of the material constituents. Thanks to such methods, it is then possible to study materials with complex microstructures that have non-simplified assumptions commonly used by other methods, as well as quantify the impact of such simplification. The versatility of XFEM in dealing with complex microstructures, including polycrystalline-like microstructures, is also shown through the role of shape inclusions on the overall effective properties o fan argillite rock. Voronoi representation is used to describe the complex microstructure of argillite.展开更多
Background: Personal hygiene in non-self-sufficient patients is essential to prevent the proliferation and spread of bacteria from one patient to another, both through inanimate objects (fomites) and directly through ...Background: Personal hygiene in non-self-sufficient patients is essential to prevent the proliferation and spread of bacteria from one patient to another, both through inanimate objects (fomites) and directly through healthcare workers. The first 1000 bed hygiene treatments performed by the collaborative robot “COPERNICO Surveillance & Prevention” in 229 non-self-sufficient patients were analyzed. Materials and Methods: A total of 229 patients were included: 215 patients came from emergency contexts or home, and 14 from long-term care facilities;the presence of sepsis, venous or urinary catheters, non-invasive ventilation, bedsores, clinical condition at discharge, and treatment sessions performed were recorded. All patients were hospitalized in the Geriatrics, Medicine and Pneumology departments. The system is able to collect and process data in real time. Results: Seventy-one patients with community-acquired sepsis and fourteen with healthcare-associated infections were treated;sixty-two had pressure ulcers. The analysis of the first 1000 treatments shows the healing of almost all sepsis cases, positive evolution of pressure ulcers, and hospital stays comparable to those of the entire group of 1008 hospitalized in the same period. There was no onset of side effects or complications. Conclusions: Although the healthcare setting is not among those at greatest risk of infections, the clinical efficacy, along with excellent evaluations from patients, family members, and healthcare personnel and the absence of side effects and complications, makes the system exceptionally manageable and user-friendly for non-self-sufficient patients.展开更多
The everyday fluctuations of temperature and humidity lead to fluctuation of stress on the stones constituting many constructions and produce in long term some kinds of fatigue damage. This paper investigates the comb...The everyday fluctuations of temperature and humidity lead to fluctuation of stress on the stones constituting many constructions and produce in long term some kinds of fatigue damage. This paper investigates the combined role of stone properties variability and environmental conditions on the generation and the amplification of stress variation and fatigue. Thus, the randomness and spatial variability 0fthe mechanical, thermal and hydraulic properties are taken into account in a finite elements model of typical stone wall masonry of Chambord Castle. The quantification of the impact of this spatial variability on the variability of generated stress is performed.展开更多
Pop-up stores present many advantages to brands and customers.They take advantage of seasonality and events and manifest themselves in a relevant way in front of the targeted customer.Following a mixed-method approach...Pop-up stores present many advantages to brands and customers.They take advantage of seasonality and events and manifest themselves in a relevant way in front of the targeted customer.Following a mixed-method approach,semi-structured interview outcomes were used to enrich the proposed research model,which was then tested by a questionnaire.Our research’s results highlighted interesting components respective to the Lebanese market’s pop-up stores;test and experimentation,collection presentation,communication and buzz creation.Test results showed that Lebanese pop-up store atmospheres are characterized by their social dimension;customers are less affected by the aesthetics and more affected by the crowd who frequents the pop-up.Results showed that customers feel happier and are more likely to stay and to spend time in the store than to make purchases.展开更多
Finite element (FE) modelling methods were implemented to perform a weakly-coupled weld simulation activity on a series of simple plate welds, to determine the effects of altering the frequency of saving the thermal t...Finite element (FE) modelling methods were implemented to perform a weakly-coupled weld simulation activity on a series of simple plate welds, to determine the effects of altering the frequency of saving the thermal time-step result upon the mechanical results. By definition, the thermal results will be unaffected, but the mechanical results are calculated from the saved thermal results, hence can be changed when the frequency of saving thermal time-steps is altered. By default, most weakly-coupled thermal-mechanical solvers will save every single thermal time-step, for accuracy. Results indicated that during the welding operation, the thermal time-steps could be reduced to saving 1-in-every-2 thermal time-steps with minimal loss in mechanical accuracy. However, during the cooling operation, every time-step was required to be saved. Whilst this seems almost counter-intuitive that the time-step during the cooling operation is in some way more critical than during welding, it must be stated that the FE software employed for this exercise has a setting allowing the time-steps to become progressively large during cooling, when thermal gradients are much lower and as such both thermal and mechanical calculations are easier to converge.展开更多
With urging problem of energy and pollution, smart grid is becoming ever important. By gradually changing the actual power grid system, smart grid may evovle into different systems by means of size, elements and strat...With urging problem of energy and pollution, smart grid is becoming ever important. By gradually changing the actual power grid system, smart grid may evovle into different systems by means of size, elements and strategies, but its fundamental requirements and objectives will not change such as optimizing production, transmission and consumption. Studying the smart grid through modeling and simulation provides us with valuable results which can not be obtained in real world due to time and cost related constraints. However, due to the complexity of the smart grid, achieving optimization is not an easy task, even using computer models. In this paper, we propose an complex system based approach to the smart grid modeling, accentuating on the optimization by combining game theoretical and classical methods in different levels. Thanks to this combination, the optimization can be achieved with flexibility and scalability, while keeping its generality.展开更多
This paper presents an analysis of the effect of two synthetic antioxidants on the vaporization processes of coconut and linseed oils for fuel use. Several studies agree on the effectiveness of synthetic or natural an...This paper presents an analysis of the effect of two synthetic antioxidants on the vaporization processes of coconut and linseed oils for fuel use. Several studies agree on the effectiveness of synthetic or natural antioxidants against the polymerization of vegetable oils. The principle of action of the latter is to increase the rate of vaporization, to the detriment of polymer formation. The droplet suspension technique where a fiber is used to hold a stationary droplet has been used. The vaporization was conducted within a closed chamber under ambient pressure conditions in an inert and oxidizing environment at temperatures of 703 K. The method involves monitoring the projected surface area of vegetable oil droplet blended with antioxidants. The projected area (mm2) of the droplet during the vaporization process as a function of time (s) has been used to determine the vaporization coefficient, or the residue formation rate. The main findings are that the two antioxidants used at 200 ppm and 500 ppm have no influence on the vaporization of saturated oils like coconut, while on unsaturated oils like linseed the two antioxidants appear to reduce slightly the deposition of residues which are identified as polymers and increase slightly vaporization rate. In practice, antioxidants could be used as additives in vegetable oils to facilitate their combustion in diesel engines, representing a potential solution for improving combustion efficiency. To enhance the reliability of the findings, it would be advisable to increase the number of antioxidants and extend the study to encompass a wider range of vegetable oils.展开更多
This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Kno...This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Knowing vegetable oils’ physical properties to these ranges of temperature is of fundamental importance when modeling their combustion in diesel engine. However, vegetable oils’ experimental physical properties data are rare in the literature for temperature above 523 K. This paper describes experimental measurements and estimation methods for density, dynamic viscosity, thermal conductivity and heat capacity of vegetable oils for this particular range of temperature. The methodology uses several correlative methods using group contribution approach for each property and compares experimental data with predicted one to select the more accurate model. This work has shown the rapeseed and jatropha oils’ physical properties can be satisfactorily predicted as a function of temperature using group contribution approach.展开更多
Background Alzheimer’s disease(AD)is the most prominent form of dementia worldwide.It is characterized by tau lesions that spread throughout the brain in a spatio-temporal manner.This has led to the prion-like propag...Background Alzheimer’s disease(AD)is the most prominent form of dementia worldwide.It is characterized by tau lesions that spread throughout the brain in a spatio-temporal manner.This has led to the prion-like propagation hypothesis implicating a transfer of pathological tau seeds from cell to cell.Human brain-derived extracellular vesicles(BD-EVs)isolated from the brain-derived fluid of AD patients contain seeds that contribute to this tau pathology spreading.Knowing the rich diversity of EVs,isolation of functional EV sub-populations is required to unravel their implication in the pathophysiology of AD.Methods Here,enriched-small EVs(eSEVs)and enriched-large EVs(eLEVs)were isolated from frozen tissues after collagenase enzymatic brain dissociation to guarantee the best EVs’integrity.Then proteomic profiling and tau seeding capacity testing were performed in vitro and in vivo.Results BD-EVs were stratified according to their size(eSEVs and eLEVs)and characterized to define new markers specific to EVs in AD.Both AD-derived eSEVs and eLEVs show the presence of GWAS-associated proteins and indicate a specific AD pathophysiological signature.Notably,AD eSEVs contain more proteins relative to the integrin-mediated synaptic signaling,while AD eLEVs proteins were more related to respiratory electron transport and brain immunity.Injection of these vesicles in transgenic mouse brain revealed that the AD-derived eSEVs are more prone than eLEVs to participate in the prion-like propagation and hence represent an interesting therapeutic target.Conclusion This study highlights the significant contribution of AD-derived EVs to tau propagation and provides new insights into different roles of EV sub-populations in AD.展开更多
文摘A large lateral shearing distance of parallel beam-splitting prism is often needed in laser modulation and polarization interference. In this letter, we present an optimized design of parallel beam-splitting prism and list some different cases in detail. The optimized design widens the use range of parallel beam-splitting prism. At the wavelength of 632.8 nm, the law that the enlargement ratio changes with the refractive index and the apex angle is verified.
文摘A comparative analysis was performed on poly(lactic acid)(PLA),poly(caprolactone)(PCL),basalt fiber(BF)composites produced using two distinct approaches:direct blending and masterbatching.The limitations of PLA-BF composites with regard to distribution and adhesion are well-documented,as are chemical treatment methods(addition of compatibilisers,surface treatments,silanization).This work aimed to study an industrially relevant potential solution of utilising a PCL-BF masterbatch,prepared as a 50/50 wt.%blend using planetary roller extrusion(PEX)to both improve the distribution and homogeneity of the fibers as well as provide a secondary adhesion site to facilitate improved mechanical properties of the final PLA-PCL-BF composite.The resultant materials were injection moulded to prepare ISO standard test specimens and tested on the basis of their physical properties via tensile testing,impact strength testing,flexural analysis,Fourier transforminfrared spectroscopy and water absorption capability.The results displayed that the incorporation of PCL and BF led to an increase in ductility of the composite materials,allowing for improvements in the inherent brittleness of virgin PLA.Major increases in the impact strength were achieved with the utilisation of a 25% PCL/BF masterbatch,allowing for a greater than 50%increase.As an overall observation,the use of a masterbatching process,opposed to direct blending of the constituent materials allows for a greater consistency of composite to be achieved at the expense of increased gains.
文摘Background: Erythrodermic psoriasis (EP) is a rare, severe variant of psoriasis characterized by widespread erythema, scaling, and systemic complications. Despite advances in systemic treatments, the management of EP remains challenging, particularly in patients with comorbidities or contraindications to standard therapies. Objectives: To evaluate the effectiveness of ozonated water as an adjunctive treatment for EP, delivered using a patented robotic therapy system designed for hygiene and infection prevention in non-self-sufficient patients. Methods: We report the case of a 90-year-old male patient with acute EP who received daily skin treatments with ozonated water in conjunction with supportive care, including rehydration and antibiotics. The intervention was facilitated by the robotic system “COPERNICO Surveillance & Prevention,” which ensured standardized hygiene practices and clinical documentation. Results: Within one week of treatment, the patient showed complete desquamation of necrotic skin, resolution of erythema, and significant metabolic recovery. Fever subsided, renal function improved, and the patient was discharged in stable condition. Follow-up confirmed sustained clinical improvement, and no adverse events were reported. Conclusions: Ozonated water demonstrated efficacy in alleviating the dermatological and systemic manifestations of EP in a high-risk elderly patient. This case highlights the potential of ozone therapy as a safe, cost-effective adjunctive treatment for EP and underscores the utility of robotic systems in managing complex dermatological conditions. Further research is warranted to validate these findings in larger cohorts.
文摘Recently,numerous estimation issues have been solved due to the developments in data-driven artificial neural networks(ANN)and graph neural networks(GNN).The primary limitation of previous methodologies has been the dependence on data that can be structured in a grid format.However,physiological recordings often exhibit irregular and unordered patterns,posing a significant challenge in conceptualising them as matrices.As a result,GNNs which comprise interactive nodes connected by edges whose weights are defined by anatomical junctions or temporal relationships have received a lot of consideration by leveraging implicit data that exists in a biological system.Additionally,our study incorporates a structural GNN to effectively differentiate between different degrees of infection in both the left and right hemispheres of the brain.Subsequently,demographic data are included,and a multi-task learning architecture is devised,integrating classification and regression tasks.The trials used an authentic dataset,including 800 brain x-ray pictures,consisting of 560 instances classified as moderate cases and 240 instances classified as severe cases.Based on empirical evidence,our methodology demonstrates superior performance in classification,surpassing other comparison methods with a notable achievement of 92.27%in terms of area under the curve as well as a correlation coefficient of 0.62.
文摘Estimating the oil-water temperatures in flowlines is challenging especially in deepwater and ultra-deepwater offshore applications where issues of flow assurance and dramatic heat transfer are likely to occur due to the temperature difference between the fluids and the surroundings. Heat transfer analysis is very important for the prediction and prevention of deposits in oil and water flowlines, which could impede the flow and give rise to huge financial losses. Therefore, a 3D mathematical model of oil-water Newtonian flow under non-isothermal conditions is established to explore the complex mechanisms of the two-phase oil-water transportation and heat transfer in different flowline inclinations. In this work, a non-isothermal two-phase flow model is first modified and then implemented in the InterFoam solver by introducing the energy equation using OpenFOAM® code. The Low Reynolds Number (LRN) k-ε turbulence model is utilized to resolve the turbulence phenomena within the oil and water mixtures. The flow patterns and the local heat transfer coefficients (HTC) for two-phase oil-water flow at different flowlines inclinations (0°, +4°, +7°) are validated by the experimental literature results and the relative errors are also compared. Global sensitivity analysis is then conducted to determine the effect of the different parameters on the performance of the produced two-phase hydrocarbon systems for effective subsea fluid transportation. Thereafter, HTC and flow patterns for oil-water flows at downward inclinations of 4°, and 7° can be predicted by the models. The velocity distribution, pressure gradient, liquid holdup, and temperature variation at the flowline cross-sections are simulated and analyzed in detail. Consequently, the numerical model can be generally applied to compute the global properties of the fluid and other operating parameters that are beneficial in the management of two-phase oil-water transportation.
文摘The past literature on the use of vegetable oils as fuel in diesel engine revealed that utilizing vegetable oil fuels in diesel engines may require property changes in the oil or perhaps, some minor engine modifications or operating changes. This study was conducted to search for the effect of atmospheric oxygen on the puffing and bursting phenomena that occur during vegetable oils droplet vaporization process in their use as fuel in diesel engine. The fiber-suspended droplet technique was used, and the normalized square droplet diameter as well as the temperature evolution vicinity the droplet was analyzed. The results show that puffing and bursting phenomena highly depend on oxygen. In presence of atmospheric oxygen, there is an increase of the puffing and bursting intensity and therefore the evaporation rate of the vegetable oil droplets, but in an inert environment or when the environment is oxygen-depleted puffing and bursting phenomena disappearing and make place of a series of explosions with lower magnitude. The lack of oxygen reduces the thermal degradation, polymerization and oxidation reactions and consequently the vaporization rate of vegetable oils droplets;and could therefore lead to the formation of deposits in the form of polymers. This is unsuitable for their use as a fuel in diesel engines. It can also be concluded that atmospheric oxygen has some positive effects on engine performance and emissions when operating with vegetable oil. These results help to address the challenge for the use of alternative fuels such as non-edible vegetable oils.
文摘The aim of this paper is to seek the numerical solution of a class of variable order fractional integral-differential equation in terms of Bernstein polynomials.The fractional derivative is described in the Caputo sense.Four kinds of operational matrixes of Bernstein polynomials are introduced and are utilized to reduce the initial equation to the solution of algebraic equations after dispersing the variable.By solving the algebraic equations,the numerical solutions are acquired.The method in general is easy to implement and yields good results.Numerical examples are provided to demonstrate the validity and applicability of the method.
文摘The mechanical behavior of geomaterials is studied using an XFEM (extended finite element method). Usually, the modeling of such heterogeneous material is performed either through an analytical homogenization approach, or numerically, especially for complex microstructures. For comparison, the effective properties are obtained using a classical finite element analysis (through the so-called unit cell method) and an analytical homogenization approach. The use of XFEM proposed here retains the accuracy oftbe classical finite element approach, allowing one to use meshes that do not necessarily match the physical boundaries of the material constituents. Thanks to such methods, it is then possible to study materials with complex microstructures that have non-simplified assumptions commonly used by other methods, as well as quantify the impact of such simplification. The versatility of XFEM in dealing with complex microstructures, including polycrystalline-like microstructures, is also shown through the role of shape inclusions on the overall effective properties o fan argillite rock. Voronoi representation is used to describe the complex microstructure of argillite.
文摘Background: Personal hygiene in non-self-sufficient patients is essential to prevent the proliferation and spread of bacteria from one patient to another, both through inanimate objects (fomites) and directly through healthcare workers. The first 1000 bed hygiene treatments performed by the collaborative robot “COPERNICO Surveillance & Prevention” in 229 non-self-sufficient patients were analyzed. Materials and Methods: A total of 229 patients were included: 215 patients came from emergency contexts or home, and 14 from long-term care facilities;the presence of sepsis, venous or urinary catheters, non-invasive ventilation, bedsores, clinical condition at discharge, and treatment sessions performed were recorded. All patients were hospitalized in the Geriatrics, Medicine and Pneumology departments. The system is able to collect and process data in real time. Results: Seventy-one patients with community-acquired sepsis and fourteen with healthcare-associated infections were treated;sixty-two had pressure ulcers. The analysis of the first 1000 treatments shows the healing of almost all sepsis cases, positive evolution of pressure ulcers, and hospital stays comparable to those of the entire group of 1008 hospitalized in the same period. There was no onset of side effects or complications. Conclusions: Although the healthcare setting is not among those at greatest risk of infections, the clinical efficacy, along with excellent evaluations from patients, family members, and healthcare personnel and the absence of side effects and complications, makes the system exceptionally manageable and user-friendly for non-self-sufficient patients.
文摘The everyday fluctuations of temperature and humidity lead to fluctuation of stress on the stones constituting many constructions and produce in long term some kinds of fatigue damage. This paper investigates the combined role of stone properties variability and environmental conditions on the generation and the amplification of stress variation and fatigue. Thus, the randomness and spatial variability 0fthe mechanical, thermal and hydraulic properties are taken into account in a finite elements model of typical stone wall masonry of Chambord Castle. The quantification of the impact of this spatial variability on the variability of generated stress is performed.
文摘Pop-up stores present many advantages to brands and customers.They take advantage of seasonality and events and manifest themselves in a relevant way in front of the targeted customer.Following a mixed-method approach,semi-structured interview outcomes were used to enrich the proposed research model,which was then tested by a questionnaire.Our research’s results highlighted interesting components respective to the Lebanese market’s pop-up stores;test and experimentation,collection presentation,communication and buzz creation.Test results showed that Lebanese pop-up store atmospheres are characterized by their social dimension;customers are less affected by the aesthetics and more affected by the crowd who frequents the pop-up.Results showed that customers feel happier and are more likely to stay and to spend time in the store than to make purchases.
文摘Finite element (FE) modelling methods were implemented to perform a weakly-coupled weld simulation activity on a series of simple plate welds, to determine the effects of altering the frequency of saving the thermal time-step result upon the mechanical results. By definition, the thermal results will be unaffected, but the mechanical results are calculated from the saved thermal results, hence can be changed when the frequency of saving thermal time-steps is altered. By default, most weakly-coupled thermal-mechanical solvers will save every single thermal time-step, for accuracy. Results indicated that during the welding operation, the thermal time-steps could be reduced to saving 1-in-every-2 thermal time-steps with minimal loss in mechanical accuracy. However, during the cooling operation, every time-step was required to be saved. Whilst this seems almost counter-intuitive that the time-step during the cooling operation is in some way more critical than during welding, it must be stated that the FE software employed for this exercise has a setting allowing the time-steps to become progressively large during cooling, when thermal gradients are much lower and as such both thermal and mechanical calculations are easier to converge.
文摘With urging problem of energy and pollution, smart grid is becoming ever important. By gradually changing the actual power grid system, smart grid may evovle into different systems by means of size, elements and strategies, but its fundamental requirements and objectives will not change such as optimizing production, transmission and consumption. Studying the smart grid through modeling and simulation provides us with valuable results which can not be obtained in real world due to time and cost related constraints. However, due to the complexity of the smart grid, achieving optimization is not an easy task, even using computer models. In this paper, we propose an complex system based approach to the smart grid modeling, accentuating on the optimization by combining game theoretical and classical methods in different levels. Thanks to this combination, the optimization can be achieved with flexibility and scalability, while keeping its generality.
文摘This paper presents an analysis of the effect of two synthetic antioxidants on the vaporization processes of coconut and linseed oils for fuel use. Several studies agree on the effectiveness of synthetic or natural antioxidants against the polymerization of vegetable oils. The principle of action of the latter is to increase the rate of vaporization, to the detriment of polymer formation. The droplet suspension technique where a fiber is used to hold a stationary droplet has been used. The vaporization was conducted within a closed chamber under ambient pressure conditions in an inert and oxidizing environment at temperatures of 703 K. The method involves monitoring the projected surface area of vegetable oil droplet blended with antioxidants. The projected area (mm2) of the droplet during the vaporization process as a function of time (s) has been used to determine the vaporization coefficient, or the residue formation rate. The main findings are that the two antioxidants used at 200 ppm and 500 ppm have no influence on the vaporization of saturated oils like coconut, while on unsaturated oils like linseed the two antioxidants appear to reduce slightly the deposition of residues which are identified as polymers and increase slightly vaporization rate. In practice, antioxidants could be used as additives in vegetable oils to facilitate their combustion in diesel engines, representing a potential solution for improving combustion efficiency. To enhance the reliability of the findings, it would be advisable to increase the number of antioxidants and extend the study to encompass a wider range of vegetable oils.
基金A.S.Zongo expresses his gratitude to French Cooperation in Burkina Faso who,through the Service for Cooperation and Cultural Action(SCAC),financed this study by awarding an internship fellowship in 2017 at CIRAD Montpellier.
文摘This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Knowing vegetable oils’ physical properties to these ranges of temperature is of fundamental importance when modeling their combustion in diesel engine. However, vegetable oils’ experimental physical properties data are rare in the literature for temperature above 523 K. This paper describes experimental measurements and estimation methods for density, dynamic viscosity, thermal conductivity and heat capacity of vegetable oils for this particular range of temperature. The methodology uses several correlative methods using group contribution approach for each property and compares experimental data with predicted one to select the more accurate model. This work has shown the rapeseed and jatropha oils’ physical properties can be satisfactorily predicted as a function of temperature using group contribution approach.
基金supported by grants from the program Investissement d’Avenir LabEx(investing in the future laboratory excellence)DISTALZ(Development of Innovative Strategies for a Transdisciplinary Approach to Alzheimer’s Disease)+2 种基金France Alzheimer,Fondation pour la Recherche Medicale and ANR grants(TONIC,TauSeed)Our laboratories are also supported by LiCEND(Lille Centre of Excellence in Neurodegenerative Disorders)CNRS,Inserm,Metropole Europeenne de Lille,University of Lille,I-SITE ULNE,Region Hauts de France and FEDER.The OrganOmics platform of PRISM Inserm U1192 which is recognized and supported by the University of Lille and,the Infrastructure PROFI(https://www.profi prote omics.fr/)and the GIS IbiSA(https://www.ibisa.net/).The OrganOmics platform(Villeneuve d’Ascq,France)is also supported by Region Hauts de France and FEDER funding.
文摘Background Alzheimer’s disease(AD)is the most prominent form of dementia worldwide.It is characterized by tau lesions that spread throughout the brain in a spatio-temporal manner.This has led to the prion-like propagation hypothesis implicating a transfer of pathological tau seeds from cell to cell.Human brain-derived extracellular vesicles(BD-EVs)isolated from the brain-derived fluid of AD patients contain seeds that contribute to this tau pathology spreading.Knowing the rich diversity of EVs,isolation of functional EV sub-populations is required to unravel their implication in the pathophysiology of AD.Methods Here,enriched-small EVs(eSEVs)and enriched-large EVs(eLEVs)were isolated from frozen tissues after collagenase enzymatic brain dissociation to guarantee the best EVs’integrity.Then proteomic profiling and tau seeding capacity testing were performed in vitro and in vivo.Results BD-EVs were stratified according to their size(eSEVs and eLEVs)and characterized to define new markers specific to EVs in AD.Both AD-derived eSEVs and eLEVs show the presence of GWAS-associated proteins and indicate a specific AD pathophysiological signature.Notably,AD eSEVs contain more proteins relative to the integrin-mediated synaptic signaling,while AD eLEVs proteins were more related to respiratory electron transport and brain immunity.Injection of these vesicles in transgenic mouse brain revealed that the AD-derived eSEVs are more prone than eLEVs to participate in the prion-like propagation and hence represent an interesting therapeutic target.Conclusion This study highlights the significant contribution of AD-derived EVs to tau propagation and provides new insights into different roles of EV sub-populations in AD.