Direct steam generation (DSG) in parabolic trough solar collectors is a feasible option for economic improvement in solar thermal power generation. Three-dimensional Eulerian two-fluid simulations are performed under OpenFOAM to study the turbulent flow in the evaporation section of the parabolic trough receiver and investigate the phase change, and pressure drop of water as a heat transfer fluid. First, the model's validity has been tested by comparing the numerical results of a laboratory scale boiler with the available correlations and semi-correlations of boiling flows from the literature. Simulations agreed well with Rouhani–Axelsson correlation for horizontal tubes, with a mean relative error of less than 7.1% for all studied cases. However, despite a mean relative error of less than 13.19% compared to the experimental data in the literature, the reported pressure drop factor remains valid; overprediction remains tolerable for most engineering applications. Second, the scaling effect on the mathematical model, from laboratory to commercial-scale configuration, was tested with experimental data of the DISS test loop in Platforma Solar de Almeria, Spain. The Monte Carlo Ray Tracing method under the Tonatiuh package allowed for obtaining the nonuniform heat flux distribution. Due to the large size of the evaporation section in the DISS loop (eight collectors), each collector is considered independently in the simulations. Thus, simulations follow each other, taking the numerical results of each collector output as input data in the next collector and so on until the last. The numerical results showed an excellent agreement for the void fraction with 3.53% against the Rouhani–Axelsson correlation. Frictional pressure losses are within a 17.06% error of the Friedel correlation, in the range of previous work in the literature, and the heat loss is less than 4.69% error versus experimental correlation.

We consider a system of transmission of the wave equation with Neumann feedback control that contains a distributed delay term and that acts on the exterior boundary. We prove under some assumptions that the solutions decay exponentially in an appropriate energy space. To establish this result, we introduce a suitable energy function and use multipliers technique method and compactness-uniqueness argument.

Due to the high degree of randomness in the microstructure of real closed-cell foams, many reported numerical models in the literature are not able to capture precisely the local morphological features found in solid foams geometry. This is still the main impediment that restricts the investigation of this novel material and motivates the development of a sophisticated 3D solid model, which describes properly the complex geometry of real closed-cell foams. In this regard, this paper presents an original approach to generate a realistic and accurate 3D computational model of irregular closed-cell foams with relative density control and detailed finite element analysis of their mechanical performance under quasi-static loading up to densification. The solid model is constructed based on spherical particles inflation simulation. It resembles the real foams in terms of local features such as cell walls irregularities and thickness variation. The modeling approach was successfully verified by comparing cell-morphological details of the generated models with those produced experimentally available in the literature and by the high-quality of obtained 3D printed models containing complex shapes and irregular cell wall thickness distribution. The evolution of spherical particles during the inflation process is analyzed based on finite element (FE) simulations. It was found that it can produce varying relative densities of foam due to the gradual decrease in the gap between the inflated particles, this makes the geometrical model of the foam suitable for studying the effect of local morphological characteristics on the mechanical performance of closed-cell foam material. To demonstrate that the compressive performance of the proposed closed-cell foam models can be controlled by relative density, 3D foam models were extracted from different inflation times and then subjected to quasi-static compression tests up to densification using the Abaqus software. The results confirm that the plateau stress can be expressed as a function of foam relative density, its accuracy is validated by comparing it to the closed-cell aluminum foam power law equation existing in the literature. The new design method offers suitable numerical models for AM technology, plenty of experimental works on closed-cell foam can be reduced for engineering applications.

Several difficulties and critical problems are facing the modern designers especially the unexpected damages. For such critical issues, the steel behavior’s investigation presents a significant point to predict fatigue life through avoiding sudden damage. An experimental study has been conducted to evaluate the AISI 1045 steel fatigue behavior using three specimens’ shapes: the first one is the conventional shape according to the ASTM E466-07 standard, the second one is performed in a notched shape, and the last specimen according to the pre-loading process. To complete the comparison among the three cases studied, a mandatory checking of the chemical compositions such as carbon content 0.45%, as well as the mechanical properties, have been investigated by preformed a tensile test in order to determine the maximum stress and the yield strength. The staircase method is employed to estimate and compare the endurance limit and its standard deviations for the three shapes. Moreover, and considered that the fatigue life expectancy of the AISI 1045 steel is a crucial step, the Stromeyer model has been proposed to predict the fatigue life which appears to be more effective, considering the average error for all cases compared to the experimental model.

The short circuit is among one of the most dangerous electrical faults in induction motors, which leads to serious implications on the motor operation and its performance. The present paper deals with the influence of the stator short circuit fault in its early stage in terms of performanceand service continuity of an electric vehicle (EV) using a dual induction motor’s structure piloted by Backstepping control. An equivalent induction motor model with turn-to-turn fault on one stator phase, without already assuming the temperature effect through an intrinsic model, is investigated. Afterward,its impacts on electric vehicle performance using simulation tests are presented anddiscussed.

The magnetohydrodynamic pump is an attractive solution, in particular for biomedical applications. In an MHD pump, an electromagnetic force is created by the applied magnetic field, which causes the fluid movement. The main advantage of the MHD pump is there are no mobile (mechanical) parts and it can place directly on veins. The present paper deals with the blood behaviour in the MHD micropump. A neodymium permanent magnet is used for applying a magnetic field to the channel in the MHD micropump. The numerical study examines the influence of the channel dimensions, the flux magnetic density and the electrode potentials on the blood velocity. This micropump can be easily controlled by a low voltage source. The numerical simulation analysis for the adopted model was implemented in order to verify the micropump operation. The magnetic and electrical fields have a strong influence on blood velocity in the MHD micropump. Finite element modelling software was used for this process. The second objective of this work is the possibility to exploit the properties of this pump in hemodialysis to pump blood and cleaning fluid.

Background A positive Patient Safety Culture (PSC) is considered as the main barrier to adverse events (AEs) that affect healthcare quality and safety. Thus, the assessment of PSC became a priority for healthcare providers in order to identify problematic areas that need improvement actions. Method A cross sectional multi-center study was conducted to evaluate quantitatively PSC in 10 Algerian healthcare establishments (HEs) within the framework of the Algerian Observatory of Safety Culture (ASCO Project). The French version of the HSOPSC was used as a measurement tool where it was administered to participants (N = 1370) using convenience sampling. Results A total of 1118 respondents, all professional categories included, participated in this study. The response rate was estimated at 69% of the sample size (N = 1370). After statistical processing, 950 questionnaires were retained. Internal consistency was above 0.7 for all dimensions. Problematic PSC dimensions were identified, mainly ‘Non-punitive response to error’, ‘Staffing’ and ‘Communication openness’. Conclusions This article sheds light on the critical situation of PSC in the Algerian national health system. Quantitative findings were introduced in the framework of the Algerian Safety Culture Observatory project that will serve as a baseline for different stakeholders to guide long-term promotion actions.

In the context of the industrial process safety, the domino effect has become a topical issue for scientists and managers of companies given the diversity of factors that contributed to the aggravation of this phenomenon such as; proximity to industrial facilities, transport networks, development of industrial complexes, storage of hazardous substances and population growth. The purpose of this article is the MICDE method (Method of Identification and Characterization of Domino Effects) application on industrial zone of LPG storage in SONATRACH-Algeria Group for analyzes the domino effects caused by a major industrial accident. Our study is adopted on the MICDE method which constitutes an aid in the integration of the domino effects problem in hazard studies and safety studies. In our application, it aims to formalize the points relating to the domino effects due to the BLEVE (Boiling Liquid Expanding Vapor Explosion) phenomenon of an LPG storage sphere. The results obtained show that the hazardous equipment in the vicinity is seriously affected by the thermal and overpressure effect of the main accident, and may be seats in a new accident. The MICDE method is a promising method can be applied in several fields since it studies the phenomenon. This method facilitates decision-making in the prevention of domino effects for the sustainability facilities

Purpose The objective of this article is to carry out an exploratory study on the emergence of health and safety committees (HSC) in Algerian companies. Design/methodology/approach The methodology chosen, governed by the systemic approach, is centered on the exploration of HSC emergence factors in companies. Findings The suggested method consists in defining hypotheses found in the literature on the emergence of HSC in order to affirm or refute them in the case of Algerian companies. Research limitations/implications Despite the fact that a good number of Algerian industrial companies were solicited; the number of respondents was limited. This limitation confirms the difficulty commonly encountered in exploratory studies by questionnaire. Practical implications The results of this exploratory study serve as a basis for the elaboration of a national action plan dedicated to HSC emergence in Algerian companies. Originality/value This is the first study conducted in Algerian companies on HSC emergence. The identification of emergence problems allows drawing up an effective action plan to solve them.

Purpose Workplace violence is a universal phenomenon that is constantly increasing. In this regard, this study aims to investigate the prevalence of violence committed against Algerian health professionals. Design/methodology/approach A cross-sectional survey, based on an anonymous, self-administered questionnaire, was conducted in healthcare settings of eastern Algeria (where 144 respondents participated in this study). Besides, socio-demographic characteristics and data related to violence, including its prevalence, different forms, perpetrators, reporting and the way it is handled, were analyzed using descriptive and inferential statistics. Findings Half of the respondents were victims of violence. More specifically, 90.1% of them were verbally abused. Compared to physical violence, verbal violence was significantly perpetrated against women and young health professionals (p < 0.05). However, nurses and those with less than or equal to five years of work experience were the most vulnerable to both types of violence (p < 0.05). Moreover, the main perpetrators were the patients’ relatives (70%) followed by the patients themselves (51.4%). In terms of risk treatment, aggressors were verbally warned (60%). For violence reporting, 31% of the respondents observe such a fact as not being important. Finally, 65.7% of the participants reported that their employers had provided them with security measures (guards). Originality/value This is the first study conducted in Algeria that examines the prevalence of violence and its relationship with socio-demographic characteristics. Authorities must react effectively to solve this problem by implementing preventive and anticipatory strategies.

Fire safety barriers installed in atmospheric storage tanks have an important role in the prevention and the mitigation of accident scenarios triggered by lightning strike. The aim of the present study is the integration of the role of fire safety barriers in the probabilistic analysis of accident scenarios triggered by lightning strike on atmospheric storage tanks of flammable liquids. A statistical analysis of past similar accidents was performed to show their importance with respect to other naturel events such as floods and earthquakes. Depending on the tank type, different event trees are provided to describe the possible event sequences and consequences following lightning impact. Fault tree method was used to quantify the expected availability of fire safety barriers, which are integrated in event trees. The event tree related to external floating roof tanks and fault trees of safety barriers have been converted to an equivalent Bayesian network for performing sensitivity analysis, in order to identify the most critical basic elements of fire safety barriers that need to be improved. The application of the methodology to a real case study proved the importance of the integration of all relevant safety barriers performance and the influence of amelioration measures on the annual probability of lightning-triggered accidents.

Purpose The purpose of this paper is to highlight the interest of focusing public policies for wildfire management on behavioral changes supported by sustainable development projects dedicated to the Algerian forest heritage. Thus, the Aurès region in the eastern part of Algeria will be used as an example to illustrate the proposed new strategy. Design/methodology/approach The proposed method, guided by projects’ management in sustainable development, consists of developing a responsible citizenship strategy focused on behavioral changes of citizens. Therefore, the title of the proposed method: The Construct of Responsible Citizenship. Findings In order to cope with forest fires, the proposed approach highlights the interest of promoting responsible citizenship. Likewise, it outlines a tool for sustaining behavioral changes based on the principle of continuous improvement and field follow-up using a multicriteria approach known as “goal programming.” Practical implications The proposed new forest fire protection plan addresses the shortcomings in Algeria’s current forest fire management policy, which appears unable to deal with the increasing severity of forests’ fire risk that the country has been experiencing in recent decades. Originality/value The aim is to highlight the interest of investment in forest fires prevention within the framework of the sustainable development of Algerian forest heritage, specifically, to work toward citizen subcontracting of the Algerian forest heritage.

تهدف الدراسة الى معرفة أثر استخدام بعض الوسائل البصرية (صور وأفلام فيديو) المساعدة في تحسين مهارة التمرير من أعلى لدى تلاميذ التعليم المتوسط، وذلك من خلال مواقف تعليمية تعرض في درس التربية البدنية، لمعرفة مدى تحسن هذه المهارة بالنسبة لتلاميذ (10-11) سنة. وبعد تنفيذ البرنامج خاص بتعلم المهارة وإجراء الاختبارات القبلية والبعدية الحصول على البينات ومعالجتها إحصائياً والحصول على النتائج، وتوصل الباحثون إلى أهم الاستنتاجات وهي: كان لاستخدام بعض الوسائل البصرية أثر إيجابي وفعال في تحسن أداء مهارة التمرير من اعلى بالكرة الطائرة. وإن أفضلية نتائج الإختبارات البعدية في إختبار مهارة التمرير من أعلى التي حققتها المجموعة التجريبية على المجموعة الضابطة. ويوصي الباحثون بما يأتي: استخدام بعض وسائل البصرية في هذه المرحلة السنية تلعب دورا كبيرا في تحسين أداء مهارة التمرير من أعلى بالكرة الطائرة. وضرورة توفير الوسائل التعليمية والأدوات من أجل تسهيل عملية التحسين وتشويق الأطفال، وخلق جو من المرح أثناء العمل. وإجراء دورات تدريبية للقائمين بالعمل في مجال الرياضة، وكيفية التعامل مع التلميذ وكيفية تعليم الأنشطة الحركية.

تهدف هذه الدراسة للتعرف على العلاقة بين بعض المهارات الحياتية وكفايات التدريس عند أساتذة التربية البدنية، استخدمنا المنهج الوصفي، تكونت عينة الدراسة من 174 فرد، استعملنا إستمارة تقيس كفايات التدريس واستمارة تقيس بعض المهارات، توصلت الدراسة لوجود علاقة ارتباطية بين بعض المهارات الحياتية عند أساتذة التربية البدنية والرياضية وكفايات التدريس لديهم.

تهدف هذه الدراسة إلى التعرف على العلاقة بين السمات الشخصية للمدرب و تماسك الفريق الرياضي"، ولإنجاز هذه الدراسة تم استخدام المنهج الوصفي بأسلوبه الارتباطي، وذلك بتطبيق مقياس فرايبورغ لقياس السمات الشخصية الذي أعد نسخته العربية محمد حسن علاوي 1998، وكذلك مقياس التماسك الاجتماعي داخل الفريق الرياًّضي هو من تصميم محمد حسن علاوي 1994، على عينة تتكون من 60 مدربا و 900 لاعب موزعين على 60 فريقا في بعض ولايات الشرق الجزائري ( باتنة، قسنطينة، أم البواقي، خنشلة، تبسة) للموسم الرياضي 2018/2019. وضحت النتائج أن هناك علاقة ذات دلالة إحصائية عند مستوى الدلالة 0.05 بارتباط موجب قوي بين التماسك الاجتماعي و سمتي الاجتماعية والهدوء، وهناك ارتباط قوي عكسي بين التماسك الاجتماعي و سمتي العصبية و العدوانية، بينما لا يوجد أي ارتباط بين التماسك الاجتماعي وسمة الكف على ضوء هذه النتائج قدمت الدراسة مجموعة من التوصيات، أهمها الاهتمام بالجانب الاجتماعي داخل الفرق الرياضية، واعتماد النمط القيادي الديمقراطي في تسييرها. الكلمات المفتاحية: السمات الشخصية؛ تماسك الفريق الرياضي؛ أنماط القيادة؛ الفريق الرياضي؛ المدرب. 

هدف البحث إلى تصميم برنامج ألعاب صغيرة لتطوير بعض عناصر اللياقة البدنية (المداومة، السرعة، المرونة) لتلاميذ المرحلة الابتدائية بعمر(10-11) سنة ،فضلا عن معرفة تأثير هذه الألعاب ، وتم إجراء هذا البحث في المدة من 19/02 /2014 ولغاية 08/05/2014 وعلى عينة من تلاميذ مدرسة سلالي فرحات الابتدائية للعام الدراسي (2013-2014) وبلغ عددهم(30) تلميذ تم تقسيمهم إلى مجموعتين متساويتين إحداهما تجريبية عملت ببرنامج الألعاب الصغيرة والأخرى ضابطة عملت بالأسلوب التقليدي، وتكونت كل مجموعة من(15) تلميذ وفي ضوء هذه الاستنتاجات أوصى الباحث بضرورة تطبيق مجموعة الألعاب الصغيرة في درس التربية الرياضية بالمدارس الابتدائية وكذلك ضرورة تهيئة البيئة التعليمية بالإمكانات والأدوات اللازمة لتطبيق الألعاب الصغيرة مع إعداد ألعاب ترويحية تعليمية للأنشطة الرياضية المختلفة التي تعمل على تطوير عناصر اللياقة البدنية لدى تلاميذ هذه المرحلة. 

يهدف هذا البحث الى معرفة وجود فروق ذات دلالة إحصائية في مستوى تقدير الذات بين ذوي الإعاقة الوراثية والمكتسبة لدى اللاعبين كرة السلة على الكراسي المتحركة، وذلك باستخدام مقياس تقدير الذات على عينة قصدية متكونة من 45 لاعب معاق حركيا ذوي الإعاقة المكتسبة والوراثية منخرطين في مختلف الفرق المستوى الوطني الأول، ولقد استخدمنا المنهج الوصفي لملائمته هذا البحث متبعين أسلوب الاحصائي الوصفي باستخدام المتوسط الحسابي والانحراف المعياري معامل الارتباط بيرسون واختبار (ت)، و أسفرت النتائج البحث بعدم وجود فروق ذات دلالة إحصائية في متوسط الدرجات النمط الأول والثاني لتقدير الذات، وبوجود فروق ذات دلالة إحصائية في النمط الثالث والرابع لتقدير الذات بين اللاعبين ذوي الإعاقة الوراثية والمكتسبة لكرة السلة على الكراسي المتحركة، ومن بعض الاقتراحات والتوصيات التي يوصي بها الباحث، استخدام طرق ارشادية نفسية تساعد اللاعبين المعاقين حركيا على بلوغهم تقدير الذات الايجابي وتوفير الوسائل والأجهزة الخاصة منها الكراسي المتحركة ذات الجودة الرفيعة.

In this article, we propose a new class of search directions based on new kernel function to solve the monotone semidefinite linear complementarity problem by primal-dual interior point algorithm. We show that this algorithm based on this function benefits from the best polynomial complexity, namely O( √ n(log n) 2 log n ). The implementation of the algorithm showed a great improvement concerning the time and the number of iterations.

In this paper, we investigate linear codes over the ring R5,3 = F5 + u1F5 + u2F5 + u3F5, and we determine the homogeneous weight of this ring, to derive some properties corresponding to these codes.

This paper is about the study of the well-posedness of a stochastic Cahn-Hilliard equation driven by white noise induced by a Q-Brownian motion. The proof of the existence of a unique global solution relies on the Galerkin method together with a monotonicity method.