High Density Polyethylene （HDPE） composites reinforced with treated bio-filler from Argan-Nut Shell （ANS） at various filler contents are prepared by extrusion and injection molding processes. The microstructures o...High Density Polyethylene （HDPE） composites reinforced with treated bio-filler from Argan-Nut Shell （ANS） at various filler contents are prepared by extrusion and injection molding processes. The microstructures of the composites are charac- terized by Fourier Transform Infrared Spectroscopy （FTIS） and Scanning Electron Microscopy （SEM）; the thermal stability is analyzed by Thermogravimetric Analysis （TGA）, and their mechanical properties are investigated by dynamical mechanical analysis and rheological testing. The morphological and structural results indicate an improvement in adhesion between the ANS fillers and HDPE matrix upon alkali treatment. The mechanical properties of the composites show a significant increase in young＇s modulus with the addition of filler, a gain of 58% is marked compared to neat polymer, Thermal analysis reveals that the incorporation of bio-filler in polymer results in a decrease in decomposition temperatures. This research offers an ecological alternative to upgrade the valorization of abundant and unexploited Moroccan resources. In addition, the possibility of finding uses for ANS in composite manufacturing will help open new markets for what is normally considered waste or for use in low value products.展开更多
Background:Fever of unknown origin(FUO)in developing countries is an important dilemma and further research is needed to elucidate the infectious causes of FUO.Methods:A multi-center study for infectious causes of FUO...Background:Fever of unknown origin(FUO)in developing countries is an important dilemma and further research is needed to elucidate the infectious causes of FUO.Methods:A multi-center study for infectious causes of FUO in lower middle-income countries(LMIC)and lowincome countries(LIC)was conducted between January 1,2018 and January 1,2023.In total,15 participating centers from seven different countries provided the data,which were collected through the Infectious DiseasesInternational Research Initiative platform.Only adult patients with confirmed infection as the cause of FUO were included in the study.The severity parameters were quick Sequential Organ Failure Assessment(qSOFA)≥2,intensive care unit(ICU)admission,vasopressor use,and invasive mechanical ventilation(IMV).Results:A total of 160 patients with infectious FUO were included in the study.Overall,148(92.5%)patients had community-acquired infections and 12(7.5%)had hospital-acquired infections.The most common infectious syndromes were tuberculosis(TB)(n=27,16.9%),infective endocarditis(n=25,15.6%),malaria(n=21,13.1%),brucellosis(n=15,9.4%),and typhoid fever(n=9,5.6%).Plasmodium falciparum,Mycobacterium tuberculosis,Brucellae,Staphylococcus aureus,Salmonella typhi,and Rickettsiae were the leading infectious agents in this study.A total of 56(35.0%)cases had invasive procedures for diagnosis.The mean qSOFA score was 0.76±0.94{median(interquartile range[IQR]):0(0–1)}.ICU admission(n=26,16.2%),vasopressor use(n=14,8.8%),and IMV(n=10,6.3%)were not rare.Overall,38(23.8%)patients had at least one of the severity parameters.The mortality rate was 15(9.4%),and the mortality was attributable to the infection causing FUO in 12(7.5%)patients.Conclusions:In LMIC and LIC,tuberculosis and cardiac infections were the most severe and the leading infections causing FUO.展开更多
AIM:To evaluate the impact of long term permanent hypoxemia noticed in patients with non operated congenital cyanogenic cyanotic cardiopathy on liver stiffness.METHODS:We included ten adult patients with non operated ...AIM:To evaluate the impact of long term permanent hypoxemia noticed in patients with non operated congenital cyanogenic cyanotic cardiopathy on liver stiffness.METHODS:We included ten adult patients with non operated inoperate cyanotic cardiopathy and ten matched patients for age and gender admitted to the gastroenterology department for proctologic diseases;Clinical and laboratory data were collected[age,gender,body mass index,oxygen saturation,glutamate oxaloacetate transaminase(GOT),glutamate pyruvate transaminase(GPT),glycemia and cholesterol].Measurement of hepatic stiffness by transient elastography was carried out in all patients using the Fibroscan device.All patients underwent an echocardiography to eliminate congestive heart failure.RESULTS:Among the patients with cyanotic cardiopathy,median liver stiffness 5.9±1.3 kPa was greater than control group(4.7±0.4 kPa)(P=0.008).Median levels of GOT,GPT,gamma-glutamyltransferase,glycemia and cholesterol were comparable in cardiopathy and control group.In regression analysis including age,gender,body mass index,oxygen saturation,GOT,GPT,glycemia,cholesterol showed that only oxygen saturation was related to liver stiffness(r=-0.63 P=0.002).CONCLUSION:Chronic permanent hypoxemia can induce mild increase of liver stiffness,but further studies are needed to explore the histological aspects of liver injury induced by chronic permanent hypoxemia.展开更多
In this paper,a detailed investigation of water(Pr=7.0)convection in a chemical condenser is carried out.Two openings are located along one side of the cavity.The Navier-Stokes equations are solved in the frame of a c...In this paper,a detailed investigation of water(Pr=7.0)convection in a chemical condenser is carried out.Two openings are located along one side of the cavity.The Navier-Stokes equations are solved in the frame of a control volume method using the SIMPLEC algorithm to implement adequate coupling of pressure and velocity.Special emphasis is given to the influence of the Reynolds number,the tilt of the channel and the Rayleigh number on the convective heat transfer.Results are presented and discussed allowing the control parameters to span relatively wide intervals:Rayleigh number(10^(4)≤Ra≤5×10^(5)),channel inclination(0°≤90°)and Reynolds number(10≤Re≤1000).On the basis of these results,a new correlation of the Nusselt number is elaborated.展开更多
Purpose: Surgical treatment of chronic anterior shoulder instability is a difficult therapeutic challenge for contact athletes. The aim of our study is to evaluate the clinical and radiological results of 40 cases of ...Purpose: Surgical treatment of chronic anterior shoulder instability is a difficult therapeutic challenge for contact athletes. The aim of our study is to evaluate the clinical and radiological results of 40 cases of chronic anterior shoulder instability treated in our institution by Latarjet technique. Methods: We report our experience with the intervention of Latarjet modified by the analysis of a retrospective study of 40 cases. They were all young athletic men, with an average age of 29 years with a predominance of the dominant shoulder. Results: Eighty percent had bone lesions, the first dislocation being traumatic (plating). One patient had a recurrence of his instability due to a new trauma and 67% resumed sport within an average period of eight months, some of whom still had functional discomfort in sports practice (9 patients). After an average follow-up of 75 months, 93% of patients were satisfied with their intervention. Only two mechanical complications were observed. Conclusion: Chronic anterior shoulder instability is pathology of young and active subjects. The preregulenoid coracoid block according to Latarjet represents the therapeutic method of choice in the treatment of chronic anterior instabilities of the shoulder, especially in young and athletic subjects. The result of this intervention remains good despite the complications that can occur such as pseudarthrosis, osteoarthritis, lysis or mobility of the screw.展开更多
Tibial pilon fractures are rare injuries most often associated with soft tissue injuries, occurring during high-energy trauma. Surgical treatment represents the therapy of choice and must ensure anatomical reconstruct...Tibial pilon fractures are rare injuries most often associated with soft tissue injuries, occurring during high-energy trauma. Surgical treatment represents the therapy of choice and must ensure anatomical reconstruction of the joint surface while respecting the surrounding tissues. The evolution of our results showed a majority of good functional clinical radio results by the open treatment which showed its superiority compared to the closed treatment and the combined treatment.展开更多
Fractures of the humeral paddle, common to young adults, are most often complex, linked to violence and an increase in road accidents. The objective of our work is to evaluate our functional results, in the medium ter...Fractures of the humeral paddle, common to young adults, are most often complex, linked to violence and an increase in road accidents. The objective of our work is to evaluate our functional results, in the medium term, correlated with a review of the literature. This is a retrospective study of 63 patients, carried out in the traumatology-orthopedics department 1 of the IBN EL JAZZAR hospital in KAIROUAN, over a period of 7 years from January 2015 to December 2021. The average age of patients was 39 years (17 - 68 years). Predominantly male. The etiologies are dominated by falls and accidents on public roads. Fractures are classified according to the Müller and Allgöwer classification where type C is found in 51% of cases. All our patients undergo an olecranon osteotomy in 71% of cases. Osteosynthesis using a Lecestre plate combined with screwing or plugging is used in 84% of cases. The evolution is marked by complications observed in eight patients (16%), including two cases of sepsis, four cases of elbow stiffness (8%), one case of joint callus and one case of pseudarthrosis. Our results are evaluated according to the Mayo Elbow Performance Score, they are excellent and good in 71% of cases, average in 18% of cases and poor in 11% of cases. Fractures of the humeral paddle are fractures with a satisfactory functional prognosis, requiring ad integrum anatomical restoration and solid osteosynthesis allowing early rehabilitation of the elbow. One case of joint callus and one case of pseudarthrosis.展开更多
The generalized travelling salesman problem(GTSP),a generalization of the well-known travelling salesman problem(TSP),is considered for our study.Since the GTSP is NP-hard and very complex,finding exact solutions is h...The generalized travelling salesman problem(GTSP),a generalization of the well-known travelling salesman problem(TSP),is considered for our study.Since the GTSP is NP-hard and very complex,finding exact solutions is highly expensive,we will develop genetic algorithms(GAs)to obtain heuristic solutions to the problem.In GAs,as the crossover is a very important process,the crossovermethods proposed for the traditional TSP could be adapted for the GTSP.The sequential constructive crossover(SCX)and three other operators are adapted to use in GAs to solve the GTSP.The effectiveness of GA using SCX is verified on some GTSP Library(GTSPLIB)instances first and then compared against GAs using the other crossover methods.The computational results show the success of the GA using SCX for this problem.Our proposed GA using SCX,and swap mutation could find average solutions whose average percentage of excesses fromthe best-known solutions is between 0.00 and 14.07 for our investigated instances.展开更多
This paper is devoted to the homogenization of a semilinear parabolic equation with rapidly oscillating coefficients in a domain periodically perforated byε-periodic holes of size ε. A Neumann condition is prescribe...This paper is devoted to the homogenization of a semilinear parabolic equation with rapidly oscillating coefficients in a domain periodically perforated byε-periodic holes of size ε. A Neumann condition is prescribed on the boundary of the holes.The presence of the holes does not allow to prove a compactness of the solutions in L2. To overcome this difficulty, the authors introduce a suitable auxiliary linear problem to which a corrector result is applied. Then, the asymptotic behaviour of the semilinear problem as ε→ 0 is described, and the limit equation is given.展开更多
The incorporation of graphite particles into AA6016 aluminum alloy matrix to fabricate metal/ceramic composites is still a great challenge and various parameters should be considered. In this study, dense AA6016 alumi...The incorporation of graphite particles into AA6016 aluminum alloy matrix to fabricate metal/ceramic composites is still a great challenge and various parameters should be considered. In this study, dense AA6016 aluminum alloy/（0-20 wt%） graphite composites have successfully been fabricated by powder metallurgy process. At first, the mixed aluminum and graphite powders were cold compacted at 200 MPa and then sintered at 500 ℃ for 1 h followed by hot extrusion at 450 ℃. The influence of ceramic phases（free graphite and in-situ formed carbides） on microstructure, physical and mechanical properties of the produced composites were finally investigated. The results show that the fabricated composites have a relative density of over 98%. SEM observations indicate that the graphite has a good dispersion in the alloy matrix even at high graphite content. Hardness of all the produced composites was higher than that of aluminum alloy matrix. No cracks were observed at strain less than 23% for all hot extruded materials.Compressive strength, reduction in height, ultimate tensile stress, fracture stress, yield stress, and fracture strain of all Al/graphite composites were determined by high precision second order equations. Both compressive and ultimate tensile strengths have been correlated to microstructure constituents with focusing on the in-situ formed ceramic phases, silicon carbide（SiC） and aluminum carbide（Al4 C3）. The ductile fracture mode of the produced composites became less dominant with increasing free graphite content and in-situ formed carbides. Wear resistance of Al/graphite composites was increased with increasing graphite content. Aluminum/20 wt% graphite composite exhibited superior wear resistance over that of AA6016 aluminum alloy.展开更多
Nowadays,materials with a limited impact on the environment are required in the construction sector.Considering the interesting properties of natural elements such as natural fibers,it seems advantageous to use them t...Nowadays,materials with a limited impact on the environment are required in the construction sector.Considering the interesting properties of natural elements such as natural fibers,it seems advantageous to use them to reinforce materials while protecting the environment and guaranteeing economic gain.Along these lines,this research was devoted to studying the effect of untreated natural fibers extracted from the Juncus maritimus plant(from Southern Morocco)on plaster.First,the effect of the percentage of added fibers on the fluidity of the plaster was evaluated by means of the Marsh’s cone method,that is,by measuring the time taken by a known volume of plaster to flow from a cone through a short tube.Then,the highly porous microstructure of the plaster was observed using a scanning electron microscope(SEM).The diffractogram of Juncus maritimus fibers was built by means of a X-ray diffraction(XRD)method.The values obtained for the wet thermal conductivity of the composites decreased from 0.4853 W/m.K for the reference specimen to 0.4324 W/m K for a fiber volume content of 40%.The densities were calculated to determine the lightness of each composite.The mechanical strengths[flexural and compressive]were evaluated for different percentages of rush fibers.The addition of 20%volume fiber was found to improve the flexural strength to 3.63 MPa compared to the sample without fiber(3.36 MPa),thereby ensuring good toughness of the considered material.Nevertheless,a reduction in compressive strength was observed,due to the poor adhesion between the fibers and the plaster matrix.展开更多
The development of bio-sourced materials is essential to ensuring sustainable construction;it is considered a locomotive of the green economy.Furthermore,it is an abundant material in our country,to which very little ...The development of bio-sourced materials is essential to ensuring sustainable construction;it is considered a locomotive of the green economy.Furthermore,it is an abundant material in our country,to which very little attention is being given.This work aims to valorize the waste of the trunks of banana trees to be used in construction.Firstly,the physicochemical properties of the fiber,such as the percentage of crystallization and its morphology,have been determined by X-ray diffraction tests and scanning electron microscopy to confirm the potential and the impact of the mode of drying on the quality of the banana fibers,with the purpose to promote the use of this material in construction.Secondly,the results obtained with the gypsum matrix allowed us to note a preponderant improvement in the composite’s thermal properties thanks to the variation of the banana fiber additive.Thirdly,the impact of the nature of the banana fiber distribution(either fiber mixed in matrix or fiber series model)on the flexural and compressive strengths of the composites was studied.The results obtained indicate that the insulation gain reaches up to 40%.It depends on the volume fraction and type of distribution of the banana fibers.However,the thermal inertia of the composites developed,represented by thermal diffusivity and thermal effusivity,was studied.Results indicate a gain of 40%and 25%,respectively,in terms of thermal diffusivity and thermal effusivity of the developed composites compared to plaster alone.Concerning the mechanical properties,the flexural strength depends on the percentage of the volume fraction of banana fibers used,and it can reach 20%more than the flexural strength of plaster;nevertheless,there is a significant loss in terms of the compressive strength of the studied composites.The results obtained are confirmed by the microstructure of the fiber banana.In fact,the morphology of the banana fibers was improved by the drying process.It reduces the amorphous area and improves the cellulosic crystalline surfaces展开更多
The modeling of an efficient classifier is a fundamental issue in automatic training involving a large volume of representative data.Hence,automatic classification is a major task that entails the use of training meth...The modeling of an efficient classifier is a fundamental issue in automatic training involving a large volume of representative data.Hence,automatic classification is a major task that entails the use of training methods capable of assigning classes to data objects by using the input activities presented to learn classes.The recognition of new elements is possible based on predefined classes.Intrusion detection systems suffer from numerous vulnerabilities during analysis and classification of data activities.To overcome this problem,new analysis methods should be derived so as to implement a relevant system to monitor circulated traffic.The main objective of this study is to model and validate a heterogeneous traffic classifier capable of categorizing collected events within networks.The new model is based on a proposed machine learning algorithm that comprises an input layer,a hidden layer,and an output layer.A reliable training algorithm is proposed to optimize the weights,and a recognition algorithm is used to validate the model.Preprocessing is applied to the collected traffic prior to the analysis step.This work aims to describe the mathematical validation of a new machine learning classifier for heterogeneous traffic and anomaly detection.展开更多
This paper presents a numerical study on natural convection and heat transfer using a hybrid nanofluid within a three-dimensional cavity under the influence of a magnetic field.The primary objective of this research i...This paper presents a numerical study on natural convection and heat transfer using a hybrid nanofluid within a three-dimensional cavity under the influence of a magnetic field.The primary objective of this research is to analyze how various magnetic field conditions affect the thermal performance of the hybrid nanofluid,particularly in terms of heat transfer and fluid motion.Specific objectives include evaluating the effects of the Rayleigh number,nanoparticle volume fraction,and Hartmann number on the dynamic and thermal fields,as well as the overall heat transfer efficiency.The transport equations were discretized using the finite volume method,and the SIMPLEC algorithm was employed to couple the velocity and pressure fields.The vertical walls of the cavity were subjected to different heating conditions,while the horizontal walls were assumed to be adiabatic.The results,presented in the form of isotherms,streamlines,and Nusselt numbers,indicate that at low Hartmann numbers,heat transfer is enhanced due to better fluid circulation and more effective thermal dissipation,particularly with increasing Rayleigh numbers and nanoparticle volume fractions.However,at higher Hartmann numbers,the magnetic field’s influence becomes dominant,significantly reducing heat transfer efficiency.In conclusion,the study shows that the hybrid nanofluid outperforms pure water and simple nanofluids in terms of thermal performance at low magnetic field strengths.However,its effectiveness diminishes as the Hartmann number increases.These findings suggest the need for alternative strategies to improve heat transfer in industrial applications involving strong magnetic fields,such as in particle accelerators or nuclear magnetic resonance(NMR)devices.展开更多
Infective endocarditis (IE) is a frequent complication in chronic hemodialysis patients (CHD). The repeated placement and manipulation of central venous catheters, underlying valvulopathies, and immunosuppression are ...Infective endocarditis (IE) is a frequent complication in chronic hemodialysis patients (CHD). The repeated placement and manipulation of central venous catheters, underlying valvulopathies, and immunosuppression are the main predisposing factors for these patients to develop IE. We aimed to highlight the clinical and microbiological specificities of IE in CHD patients, detail the therapeutic management in these patients and identify the risk factors for in-hospital mortality. We included 28 CHD patients in whom the diagnosis of IE was established according to modified Duke criteria. The mean age was 47 ± 17 years. Among them, 57% were hypertensive and 39% were diabetic. The average duration of hemodialysis was 3.5 ± 7 years. The vascular access was a tunnelled jugular catheter, arteriovenous fistula, and temporary catheter in 54%, 28%, and 18% of patients, respectively. Half of the patients presented with heart failure at admission. Methicillin-sensitive Staphylococcus is the most commonly implicated pathogen. Transthoracic echocardiography revealed vegetation in all patients. In 60% of cases, the lesion is located on the mitral valve, and in 35% it is on the tricuspid valve. Patients initially received empirical antibiotic therapy, which was adjusted according to bacteriological results. Valve surgery was indicated in 12 patients, with aortic valve replacement being the most performed procedure followed by tricuspid annuloplasty. The in-hospital mortality rate was 32%. Factors associated with mortality were severe mitral insufficiency (p = 0.036), heart failure (p = 0.043), and the presence of Methicillin-resistant Staphylococcus in blood cultures (p = 0.047). IE is a complication with high morbidity and mortality. Its increasing incidence, specificities in chronic CHD patients, and the complexity of its management require a rigorous preventive strategy. A multidisciplinary collaboration between nephrologists, infectious disease specialists, cardiologists, and surgeons is crucial to optimize therapeutic manag展开更多
Introduction: Systemic lupus erythematosus is a multifactorial autoimmune disease characterised by its clinical polymorphism and its course in flares. The aim of our study was to determine the effects of pregnancy on ...Introduction: Systemic lupus erythematosus is a multifactorial autoimmune disease characterised by its clinical polymorphism and its course in flares. The aim of our study was to determine the effects of pregnancy on lupus and vice versa. Material and Methods: This is a retrospective study conducted over a period of 14 years from 2002 to 2015. We included cases of systemic lupus erythematosus associated with pregnancy followed at the obstetrics and gynecology department “C” of the Ibn Rochd University Hospital in Casablanca. Results: The mean age of our parturients was 31.4 years. All our patients were known to have lupus and were followed up. Pregnancy was terminated in six (20%) cases. We noted one (3%) case of intrauterine fetal death, four (13%) cases of intrauterine growth retardation, and five (16%) cases of prematurity. Lupus flare during pregnancy occurred in 16 (52%) cases, including one (3%) patient who developed superimposed pre-eclampsia, had a renal relapse in the third trimester requiring an abortion at 32 weeks of gestation with three sessions of hemodialysis, and another patient who developed eclampsia. Conclusion: A better understanding of the aggravating factors and compatible treatments has led to a more widespread authorization of pregnancy.展开更多
Conventional orthogonal polynomial approach can solve the multilayered plate only when the material properties of two adjacent layers do not change significantly. This paper de- veloped an improved orthogonal polynomi...Conventional orthogonal polynomial approach can solve the multilayered plate only when the material properties of two adjacent layers do not change significantly. This paper de- veloped an improved orthogonal polynomial approach to solve wave propagation in multilayered plates with very dissimilar material properties. Through numerical comparisons among the exact solution, the results from the conventional polynomial approach and from the improved poly- nomial approach, the validity of the improved polynomial approach is illustrated. Finally, it is shown that the conventional polynomial approach can not yield correct continuous normal stress profiles. The improved orthogonul polynomial approach has overcome this drawback.展开更多
Introduction: Type 1 cardiorenal syndrome (CRS 1) is characterized by acute impairment of cardiac function leading to acute renal dysfunction. CRS1 is present in 25% of patients admitted for heart failure. The objecti...Introduction: Type 1 cardiorenal syndrome (CRS 1) is characterized by acute impairment of cardiac function leading to acute renal dysfunction. CRS1 is present in 25% of patients admitted for heart failure. The objective of our study is to analyze the epidemiological, clinical, therapeutic profile and the risk and prognostic factors of these patients. Materials and Methods: We identified 120 patients with cardiorenal syndrome (CRS) over a one-year period to determine the prevalence and risk factors for developing CRS 1. We analyzed the clinical, biological, and evolutionary profiles of patients with CRS 1 and determined the risk factors for the occurrence of acute kidney injury (AKI) as well as the mortality factors in these patients. Résultats: The average age of our patients with CRS1 is 58 ± 9 years, with a sex ratio of 1.4. The average eGFR of our patients is 35 ± 6.5 ml/min/1.73m2. Diabetes was found in 17% of our patients and hypertension in 14%. The etiology of cardiac impairment is predominantly acute coronary syndrome (ACS), followed by rhythm disorders. Renally, all our patients have acute kidney injury (AKI), with 86% having functional acute renal failure and 14% having acute tubular necrosis. Therapeutically, 50% of our patients are on diuretics, 42% receive beta-blocker treatment, and RAAS blockers are used in 29% of cases. Renal replacement therapy (RRT) sessions were required in 13.8% of cases. In univariate analysis, male gender, tachyarrhythmia, and hypertension are associated with the early onset of acute kidney injury (AKI). The use of diuretics, anemia, and low left ventricular ejection fraction (LVEF) are linked to a higher risk of developing CRS 1 (p = 0.021, p = 0.037, p = 0.010 respectively). In multivariate analysis, advanced age is significantly associated with increased mortality risk in CRS 1 patients (p = 0.030), while beta-blocker use is considered a protective factor (p = 0.014). Conclusion: Our study identifies several key factors associated with outcomes in type 1 CRS. Male gend展开更多
Online Social Networks(OSNs)are based on the sharing of different types of information and on various interactions(comments,reactions,and sharing).One of these important actions is the emotional reaction to the conten...Online Social Networks(OSNs)are based on the sharing of different types of information and on various interactions(comments,reactions,and sharing).One of these important actions is the emotional reaction to the content.The diversity of reaction types available on Facebook(namely FB)enables users to express their feelings,and its traceability creates and enriches the users’emotional identity in the virtual world.This paper is based on the analysis of 119875012 FB reactions(Like,Love,Haha,Wow,Sad,Angry,Thankful,and Pride)made at multiple levels(publications,comments,and sub-comments)to study and classify the users’emotional behavior,visualize the distribution of different types of reactions,and analyze the gender impact on emotion generation.All of these can be achieved by addressing these research questions:who reacts the most?Which emotion is the most expressed?展开更多
Genetic algorithms(GAs)are very good metaheuristic algorithms that are suitable for solving NP-hard combinatorial optimization problems.AsimpleGAbeginswith a set of solutions represented by a population of chromosomes...Genetic algorithms(GAs)are very good metaheuristic algorithms that are suitable for solving NP-hard combinatorial optimization problems.AsimpleGAbeginswith a set of solutions represented by a population of chromosomes and then uses the idea of survival of the fittest in the selection process to select some fitter chromosomes.It uses a crossover operator to create better offspring chromosomes and thus,converges the population.Also,it uses a mutation operator to explore the unexplored areas by the crossover operator,and thus,diversifies the GA search space.A combination of crossover and mutation operators makes the GA search strong enough to reach the optimal solution.However,appropriate selection and combination of crossover operator and mutation operator can lead to a very good GA for solving an optimization problem.In this present paper,we aim to study the benchmark traveling salesman problem(TSP).We developed several genetic algorithms using seven crossover operators and six mutation operators for the TSP and then compared them to some benchmark TSPLIB instances.The experimental studies show the effectiveness of the combination of a comprehensive sequential constructive crossover operator and insertion mutation operator for the problem.The GA using the comprehensive sequential constructive crossover with insertion mutation could find average solutions whose average percentage of excesses from the best-known solutions are between 0.22 and 14.94 for our experimented problem instances.展开更多
文摘High Density Polyethylene （HDPE） composites reinforced with treated bio-filler from Argan-Nut Shell （ANS） at various filler contents are prepared by extrusion and injection molding processes. The microstructures of the composites are charac- terized by Fourier Transform Infrared Spectroscopy （FTIS） and Scanning Electron Microscopy （SEM）; the thermal stability is analyzed by Thermogravimetric Analysis （TGA）, and their mechanical properties are investigated by dynamical mechanical analysis and rheological testing. The morphological and structural results indicate an improvement in adhesion between the ANS fillers and HDPE matrix upon alkali treatment. The mechanical properties of the composites show a significant increase in young＇s modulus with the addition of filler, a gain of 58% is marked compared to neat polymer, Thermal analysis reveals that the incorporation of bio-filler in polymer results in a decrease in decomposition temperatures. This research offers an ecological alternative to upgrade the valorization of abundant and unexploited Moroccan resources. In addition, the possibility of finding uses for ANS in composite manufacturing will help open new markets for what is normally considered waste or for use in low value products.
文摘Background:Fever of unknown origin(FUO)in developing countries is an important dilemma and further research is needed to elucidate the infectious causes of FUO.Methods:A multi-center study for infectious causes of FUO in lower middle-income countries(LMIC)and lowincome countries(LIC)was conducted between January 1,2018 and January 1,2023.In total,15 participating centers from seven different countries provided the data,which were collected through the Infectious DiseasesInternational Research Initiative platform.Only adult patients with confirmed infection as the cause of FUO were included in the study.The severity parameters were quick Sequential Organ Failure Assessment(qSOFA)≥2,intensive care unit(ICU)admission,vasopressor use,and invasive mechanical ventilation(IMV).Results:A total of 160 patients with infectious FUO were included in the study.Overall,148(92.5%)patients had community-acquired infections and 12(7.5%)had hospital-acquired infections.The most common infectious syndromes were tuberculosis(TB)(n=27,16.9%),infective endocarditis(n=25,15.6%),malaria(n=21,13.1%),brucellosis(n=15,9.4%),and typhoid fever(n=9,5.6%).Plasmodium falciparum,Mycobacterium tuberculosis,Brucellae,Staphylococcus aureus,Salmonella typhi,and Rickettsiae were the leading infectious agents in this study.A total of 56(35.0%)cases had invasive procedures for diagnosis.The mean qSOFA score was 0.76±0.94{median(interquartile range[IQR]):0(0–1)}.ICU admission(n=26,16.2%),vasopressor use(n=14,8.8%),and IMV(n=10,6.3%)were not rare.Overall,38(23.8%)patients had at least one of the severity parameters.The mortality rate was 15(9.4%),and the mortality was attributable to the infection causing FUO in 12(7.5%)patients.Conclusions:In LMIC and LIC,tuberculosis and cardiac infections were the most severe and the leading infections causing FUO.
文摘AIM:To evaluate the impact of long term permanent hypoxemia noticed in patients with non operated congenital cyanogenic cyanotic cardiopathy on liver stiffness.METHODS:We included ten adult patients with non operated inoperate cyanotic cardiopathy and ten matched patients for age and gender admitted to the gastroenterology department for proctologic diseases;Clinical and laboratory data were collected[age,gender,body mass index,oxygen saturation,glutamate oxaloacetate transaminase(GOT),glutamate pyruvate transaminase(GPT),glycemia and cholesterol].Measurement of hepatic stiffness by transient elastography was carried out in all patients using the Fibroscan device.All patients underwent an echocardiography to eliminate congestive heart failure.RESULTS:Among the patients with cyanotic cardiopathy,median liver stiffness 5.9±1.3 kPa was greater than control group(4.7±0.4 kPa)(P=0.008).Median levels of GOT,GPT,gamma-glutamyltransferase,glycemia and cholesterol were comparable in cardiopathy and control group.In regression analysis including age,gender,body mass index,oxygen saturation,GOT,GPT,glycemia,cholesterol showed that only oxygen saturation was related to liver stiffness(r=-0.63 P=0.002).CONCLUSION:Chronic permanent hypoxemia can induce mild increase of liver stiffness,but further studies are needed to explore the histological aspects of liver injury induced by chronic permanent hypoxemia.
文摘In this paper,a detailed investigation of water(Pr=7.0)convection in a chemical condenser is carried out.Two openings are located along one side of the cavity.The Navier-Stokes equations are solved in the frame of a control volume method using the SIMPLEC algorithm to implement adequate coupling of pressure and velocity.Special emphasis is given to the influence of the Reynolds number,the tilt of the channel and the Rayleigh number on the convective heat transfer.Results are presented and discussed allowing the control parameters to span relatively wide intervals:Rayleigh number(10^(4)≤Ra≤5×10^(5)),channel inclination(0°≤90°)and Reynolds number(10≤Re≤1000).On the basis of these results,a new correlation of the Nusselt number is elaborated.
文摘Purpose: Surgical treatment of chronic anterior shoulder instability is a difficult therapeutic challenge for contact athletes. The aim of our study is to evaluate the clinical and radiological results of 40 cases of chronic anterior shoulder instability treated in our institution by Latarjet technique. Methods: We report our experience with the intervention of Latarjet modified by the analysis of a retrospective study of 40 cases. They were all young athletic men, with an average age of 29 years with a predominance of the dominant shoulder. Results: Eighty percent had bone lesions, the first dislocation being traumatic (plating). One patient had a recurrence of his instability due to a new trauma and 67% resumed sport within an average period of eight months, some of whom still had functional discomfort in sports practice (9 patients). After an average follow-up of 75 months, 93% of patients were satisfied with their intervention. Only two mechanical complications were observed. Conclusion: Chronic anterior shoulder instability is pathology of young and active subjects. The preregulenoid coracoid block according to Latarjet represents the therapeutic method of choice in the treatment of chronic anterior instabilities of the shoulder, especially in young and athletic subjects. The result of this intervention remains good despite the complications that can occur such as pseudarthrosis, osteoarthritis, lysis or mobility of the screw.
文摘Tibial pilon fractures are rare injuries most often associated with soft tissue injuries, occurring during high-energy trauma. Surgical treatment represents the therapy of choice and must ensure anatomical reconstruction of the joint surface while respecting the surrounding tissues. The evolution of our results showed a majority of good functional clinical radio results by the open treatment which showed its superiority compared to the closed treatment and the combined treatment.
文摘Fractures of the humeral paddle, common to young adults, are most often complex, linked to violence and an increase in road accidents. The objective of our work is to evaluate our functional results, in the medium term, correlated with a review of the literature. This is a retrospective study of 63 patients, carried out in the traumatology-orthopedics department 1 of the IBN EL JAZZAR hospital in KAIROUAN, over a period of 7 years from January 2015 to December 2021. The average age of patients was 39 years (17 - 68 years). Predominantly male. The etiologies are dominated by falls and accidents on public roads. Fractures are classified according to the Müller and Allgöwer classification where type C is found in 51% of cases. All our patients undergo an olecranon osteotomy in 71% of cases. Osteosynthesis using a Lecestre plate combined with screwing or plugging is used in 84% of cases. The evolution is marked by complications observed in eight patients (16%), including two cases of sepsis, four cases of elbow stiffness (8%), one case of joint callus and one case of pseudarthrosis. Our results are evaluated according to the Mayo Elbow Performance Score, they are excellent and good in 71% of cases, average in 18% of cases and poor in 11% of cases. Fractures of the humeral paddle are fractures with a satisfactory functional prognosis, requiring ad integrum anatomical restoration and solid osteosynthesis allowing early rehabilitation of the elbow. One case of joint callus and one case of pseudarthrosis.
基金the Deanship of Scientific Research,Imam Mohammad Ibn Saud Islamic University(IMSIU),Saudi Arabia,for funding this research work through Grant No.(221412020).
文摘The generalized travelling salesman problem(GTSP),a generalization of the well-known travelling salesman problem(TSP),is considered for our study.Since the GTSP is NP-hard and very complex,finding exact solutions is highly expensive,we will develop genetic algorithms(GAs)to obtain heuristic solutions to the problem.In GAs,as the crossover is a very important process,the crossovermethods proposed for the traditional TSP could be adapted for the GTSP.The sequential constructive crossover(SCX)and three other operators are adapted to use in GAs to solve the GTSP.The effectiveness of GA using SCX is verified on some GTSP Library(GTSPLIB)instances first and then compared against GAs using the other crossover methods.The computational results show the success of the GA using SCX for this problem.Our proposed GA using SCX,and swap mutation could find average solutions whose average percentage of excesses fromthe best-known solutions is between 0.00 and 14.07 for our investigated instances.
基金Project supported by the European Research and Training Network "HMS 2000" of the European Union under Contract HPRN-2000-00109.
文摘This paper is devoted to the homogenization of a semilinear parabolic equation with rapidly oscillating coefficients in a domain periodically perforated byε-periodic holes of size ε. A Neumann condition is prescribed on the boundary of the holes.The presence of the holes does not allow to prove a compactness of the solutions in L2. To overcome this difficulty, the authors introduce a suitable auxiliary linear problem to which a corrector result is applied. Then, the asymptotic behaviour of the semilinear problem as ε→ 0 is described, and the limit equation is given.
文摘The incorporation of graphite particles into AA6016 aluminum alloy matrix to fabricate metal/ceramic composites is still a great challenge and various parameters should be considered. In this study, dense AA6016 aluminum alloy/（0-20 wt%） graphite composites have successfully been fabricated by powder metallurgy process. At first, the mixed aluminum and graphite powders were cold compacted at 200 MPa and then sintered at 500 ℃ for 1 h followed by hot extrusion at 450 ℃. The influence of ceramic phases（free graphite and in-situ formed carbides） on microstructure, physical and mechanical properties of the produced composites were finally investigated. The results show that the fabricated composites have a relative density of over 98%. SEM observations indicate that the graphite has a good dispersion in the alloy matrix even at high graphite content. Hardness of all the produced composites was higher than that of aluminum alloy matrix. No cracks were observed at strain less than 23% for all hot extruded materials.Compressive strength, reduction in height, ultimate tensile stress, fracture stress, yield stress, and fracture strain of all Al/graphite composites were determined by high precision second order equations. Both compressive and ultimate tensile strengths have been correlated to microstructure constituents with focusing on the in-situ formed ceramic phases, silicon carbide（SiC） and aluminum carbide（Al4 C3）. The ductile fracture mode of the produced composites became less dominant with increasing free graphite content and in-situ formed carbides. Wear resistance of Al/graphite composites was increased with increasing graphite content. Aluminum/20 wt% graphite composite exhibited superior wear resistance over that of AA6016 aluminum alloy.
文摘Nowadays,materials with a limited impact on the environment are required in the construction sector.Considering the interesting properties of natural elements such as natural fibers,it seems advantageous to use them to reinforce materials while protecting the environment and guaranteeing economic gain.Along these lines,this research was devoted to studying the effect of untreated natural fibers extracted from the Juncus maritimus plant(from Southern Morocco)on plaster.First,the effect of the percentage of added fibers on the fluidity of the plaster was evaluated by means of the Marsh’s cone method,that is,by measuring the time taken by a known volume of plaster to flow from a cone through a short tube.Then,the highly porous microstructure of the plaster was observed using a scanning electron microscope(SEM).The diffractogram of Juncus maritimus fibers was built by means of a X-ray diffraction(XRD)method.The values obtained for the wet thermal conductivity of the composites decreased from 0.4853 W/m.K for the reference specimen to 0.4324 W/m K for a fiber volume content of 40%.The densities were calculated to determine the lightness of each composite.The mechanical strengths[flexural and compressive]were evaluated for different percentages of rush fibers.The addition of 20%volume fiber was found to improve the flexural strength to 3.63 MPa compared to the sample without fiber(3.36 MPa),thereby ensuring good toughness of the considered material.Nevertheless,a reduction in compressive strength was observed,due to the poor adhesion between the fibers and the plaster matrix.
文摘The development of bio-sourced materials is essential to ensuring sustainable construction;it is considered a locomotive of the green economy.Furthermore,it is an abundant material in our country,to which very little attention is being given.This work aims to valorize the waste of the trunks of banana trees to be used in construction.Firstly,the physicochemical properties of the fiber,such as the percentage of crystallization and its morphology,have been determined by X-ray diffraction tests and scanning electron microscopy to confirm the potential and the impact of the mode of drying on the quality of the banana fibers,with the purpose to promote the use of this material in construction.Secondly,the results obtained with the gypsum matrix allowed us to note a preponderant improvement in the composite’s thermal properties thanks to the variation of the banana fiber additive.Thirdly,the impact of the nature of the banana fiber distribution(either fiber mixed in matrix or fiber series model)on the flexural and compressive strengths of the composites was studied.The results obtained indicate that the insulation gain reaches up to 40%.It depends on the volume fraction and type of distribution of the banana fibers.However,the thermal inertia of the composites developed,represented by thermal diffusivity and thermal effusivity,was studied.Results indicate a gain of 40%and 25%,respectively,in terms of thermal diffusivity and thermal effusivity of the developed composites compared to plaster alone.Concerning the mechanical properties,the flexural strength depends on the percentage of the volume fraction of banana fibers used,and it can reach 20%more than the flexural strength of plaster;nevertheless,there is a significant loss in terms of the compressive strength of the studied composites.The results obtained are confirmed by the microstructure of the fiber banana.In fact,the morphology of the banana fibers was improved by the drying process.It reduces the amorphous area and improves the cellulosic crystalline surfaces
文摘The modeling of an efficient classifier is a fundamental issue in automatic training involving a large volume of representative data.Hence,automatic classification is a major task that entails the use of training methods capable of assigning classes to data objects by using the input activities presented to learn classes.The recognition of new elements is possible based on predefined classes.Intrusion detection systems suffer from numerous vulnerabilities during analysis and classification of data activities.To overcome this problem,new analysis methods should be derived so as to implement a relevant system to monitor circulated traffic.The main objective of this study is to model and validate a heterogeneous traffic classifier capable of categorizing collected events within networks.The new model is based on a proposed machine learning algorithm that comprises an input layer,a hidden layer,and an output layer.A reliable training algorithm is proposed to optimize the weights,and a recognition algorithm is used to validate the model.Preprocessing is applied to the collected traffic prior to the analysis step.This work aims to describe the mathematical validation of a new machine learning classifier for heterogeneous traffic and anomaly detection.
文摘This paper presents a numerical study on natural convection and heat transfer using a hybrid nanofluid within a three-dimensional cavity under the influence of a magnetic field.The primary objective of this research is to analyze how various magnetic field conditions affect the thermal performance of the hybrid nanofluid,particularly in terms of heat transfer and fluid motion.Specific objectives include evaluating the effects of the Rayleigh number,nanoparticle volume fraction,and Hartmann number on the dynamic and thermal fields,as well as the overall heat transfer efficiency.The transport equations were discretized using the finite volume method,and the SIMPLEC algorithm was employed to couple the velocity and pressure fields.The vertical walls of the cavity were subjected to different heating conditions,while the horizontal walls were assumed to be adiabatic.The results,presented in the form of isotherms,streamlines,and Nusselt numbers,indicate that at low Hartmann numbers,heat transfer is enhanced due to better fluid circulation and more effective thermal dissipation,particularly with increasing Rayleigh numbers and nanoparticle volume fractions.However,at higher Hartmann numbers,the magnetic field’s influence becomes dominant,significantly reducing heat transfer efficiency.In conclusion,the study shows that the hybrid nanofluid outperforms pure water and simple nanofluids in terms of thermal performance at low magnetic field strengths.However,its effectiveness diminishes as the Hartmann number increases.These findings suggest the need for alternative strategies to improve heat transfer in industrial applications involving strong magnetic fields,such as in particle accelerators or nuclear magnetic resonance(NMR)devices.
文摘Infective endocarditis (IE) is a frequent complication in chronic hemodialysis patients (CHD). The repeated placement and manipulation of central venous catheters, underlying valvulopathies, and immunosuppression are the main predisposing factors for these patients to develop IE. We aimed to highlight the clinical and microbiological specificities of IE in CHD patients, detail the therapeutic management in these patients and identify the risk factors for in-hospital mortality. We included 28 CHD patients in whom the diagnosis of IE was established according to modified Duke criteria. The mean age was 47 ± 17 years. Among them, 57% were hypertensive and 39% were diabetic. The average duration of hemodialysis was 3.5 ± 7 years. The vascular access was a tunnelled jugular catheter, arteriovenous fistula, and temporary catheter in 54%, 28%, and 18% of patients, respectively. Half of the patients presented with heart failure at admission. Methicillin-sensitive Staphylococcus is the most commonly implicated pathogen. Transthoracic echocardiography revealed vegetation in all patients. In 60% of cases, the lesion is located on the mitral valve, and in 35% it is on the tricuspid valve. Patients initially received empirical antibiotic therapy, which was adjusted according to bacteriological results. Valve surgery was indicated in 12 patients, with aortic valve replacement being the most performed procedure followed by tricuspid annuloplasty. The in-hospital mortality rate was 32%. Factors associated with mortality were severe mitral insufficiency (p = 0.036), heart failure (p = 0.043), and the presence of Methicillin-resistant Staphylococcus in blood cultures (p = 0.047). IE is a complication with high morbidity and mortality. Its increasing incidence, specificities in chronic CHD patients, and the complexity of its management require a rigorous preventive strategy. A multidisciplinary collaboration between nephrologists, infectious disease specialists, cardiologists, and surgeons is crucial to optimize therapeutic manag
文摘Introduction: Systemic lupus erythematosus is a multifactorial autoimmune disease characterised by its clinical polymorphism and its course in flares. The aim of our study was to determine the effects of pregnancy on lupus and vice versa. Material and Methods: This is a retrospective study conducted over a period of 14 years from 2002 to 2015. We included cases of systemic lupus erythematosus associated with pregnancy followed at the obstetrics and gynecology department “C” of the Ibn Rochd University Hospital in Casablanca. Results: The mean age of our parturients was 31.4 years. All our patients were known to have lupus and were followed up. Pregnancy was terminated in six (20%) cases. We noted one (3%) case of intrauterine fetal death, four (13%) cases of intrauterine growth retardation, and five (16%) cases of prematurity. Lupus flare during pregnancy occurred in 16 (52%) cases, including one (3%) patient who developed superimposed pre-eclampsia, had a renal relapse in the third trimester requiring an abortion at 32 weeks of gestation with three sessions of hemodialysis, and another patient who developed eclampsia. Conclusion: A better understanding of the aggravating factors and compatible treatments has led to a more widespread authorization of pregnancy.
基金supported by the National Natural Science Foundation of China(No.11272115)
文摘Conventional orthogonal polynomial approach can solve the multilayered plate only when the material properties of two adjacent layers do not change significantly. This paper de- veloped an improved orthogonal polynomial approach to solve wave propagation in multilayered plates with very dissimilar material properties. Through numerical comparisons among the exact solution, the results from the conventional polynomial approach and from the improved poly- nomial approach, the validity of the improved polynomial approach is illustrated. Finally, it is shown that the conventional polynomial approach can not yield correct continuous normal stress profiles. The improved orthogonul polynomial approach has overcome this drawback.
文摘Introduction: Type 1 cardiorenal syndrome (CRS 1) is characterized by acute impairment of cardiac function leading to acute renal dysfunction. CRS1 is present in 25% of patients admitted for heart failure. The objective of our study is to analyze the epidemiological, clinical, therapeutic profile and the risk and prognostic factors of these patients. Materials and Methods: We identified 120 patients with cardiorenal syndrome (CRS) over a one-year period to determine the prevalence and risk factors for developing CRS 1. We analyzed the clinical, biological, and evolutionary profiles of patients with CRS 1 and determined the risk factors for the occurrence of acute kidney injury (AKI) as well as the mortality factors in these patients. Résultats: The average age of our patients with CRS1 is 58 ± 9 years, with a sex ratio of 1.4. The average eGFR of our patients is 35 ± 6.5 ml/min/1.73m2. Diabetes was found in 17% of our patients and hypertension in 14%. The etiology of cardiac impairment is predominantly acute coronary syndrome (ACS), followed by rhythm disorders. Renally, all our patients have acute kidney injury (AKI), with 86% having functional acute renal failure and 14% having acute tubular necrosis. Therapeutically, 50% of our patients are on diuretics, 42% receive beta-blocker treatment, and RAAS blockers are used in 29% of cases. Renal replacement therapy (RRT) sessions were required in 13.8% of cases. In univariate analysis, male gender, tachyarrhythmia, and hypertension are associated with the early onset of acute kidney injury (AKI). The use of diuretics, anemia, and low left ventricular ejection fraction (LVEF) are linked to a higher risk of developing CRS 1 (p = 0.021, p = 0.037, p = 0.010 respectively). In multivariate analysis, advanced age is significantly associated with increased mortality risk in CRS 1 patients (p = 0.030), while beta-blocker use is considered a protective factor (p = 0.014). Conclusion: Our study identifies several key factors associated with outcomes in type 1 CRS. Male gend
文摘Online Social Networks(OSNs)are based on the sharing of different types of information and on various interactions(comments,reactions,and sharing).One of these important actions is the emotional reaction to the content.The diversity of reaction types available on Facebook(namely FB)enables users to express their feelings,and its traceability creates and enriches the users’emotional identity in the virtual world.This paper is based on the analysis of 119875012 FB reactions(Like,Love,Haha,Wow,Sad,Angry,Thankful,and Pride)made at multiple levels(publications,comments,and sub-comments)to study and classify the users’emotional behavior,visualize the distribution of different types of reactions,and analyze the gender impact on emotion generation.All of these can be achieved by addressing these research questions:who reacts the most?Which emotion is the most expressed?
基金the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University(IMSIU)(Grant Number IMSIU-RP23030).
文摘Genetic algorithms(GAs)are very good metaheuristic algorithms that are suitable for solving NP-hard combinatorial optimization problems.AsimpleGAbeginswith a set of solutions represented by a population of chromosomes and then uses the idea of survival of the fittest in the selection process to select some fitter chromosomes.It uses a crossover operator to create better offspring chromosomes and thus,converges the population.Also,it uses a mutation operator to explore the unexplored areas by the crossover operator,and thus,diversifies the GA search space.A combination of crossover and mutation operators makes the GA search strong enough to reach the optimal solution.However,appropriate selection and combination of crossover operator and mutation operator can lead to a very good GA for solving an optimization problem.In this present paper,we aim to study the benchmark traveling salesman problem(TSP).We developed several genetic algorithms using seven crossover operators and six mutation operators for the TSP and then compared them to some benchmark TSPLIB instances.The experimental studies show the effectiveness of the combination of a comprehensive sequential constructive crossover operator and insertion mutation operator for the problem.The GA using the comprehensive sequential constructive crossover with insertion mutation could find average solutions whose average percentage of excesses from the best-known solutions are between 0.22 and 14.94 for our experimented problem instances.
