Potential use of recycled cork as aggregates for lightweight self-compacting concrete production

This work questions the possibility of using expanded black cork aggregates (EBCA), for the production of lightweight self-compacting concrete. Five concrete mixtures were tested: concrete made entirely with natural aggregate as a control concrete and four concrete mixtures made with cork recycled aggregate (5, 25, 50 and 75% replacement in volume of natural aggregate). The estimation of the success of the formulations was judged by studying the properties of concrete in the fresh state by the slump flow, T500, L-box and the sieve stability tests. In the hardened state, the properties of the concrete produced have been determined by compressive and flexural strengths and bulk density tests. The experimental results showed that as the replacement level of natural aggregates by EBCA increased, the flowability of the concrete decreased. However, a good flowability was obtained for concrete mixtures containing EBCA until 50%, satisfying the recommendations of self-compacting concrete given by EFNARC 2002. The obtained results indicate the possible use of EBCA for the production of lightweight self-compacting concrete, the replacement of 50% of natural aggregates by EBCA allows obtaining a formulation which corresponds to a lightweight self-compacting concrete with a density of 1750kg/m3 and a compressive strength of 8MPa

Quelques particularités linguistiques dans l’œuvre de Belaid At Ali

AgzulDeg tezrawt-agi, ad ɛerdeɣ ad selḍeɣ kra tulimisin n tutlayt yessexdem Belaid At-Ɛli deg uḍris-is Lwali n udrar. Mebla ma muqqleɣ ɣer udem aseklan d wudem uɣnib, ad ɛerdeɣ ad d-sekneɣ lewṣayef n tutlayt n umaru-agi.AbstractI propose to examine in this text some particularities of a linguistic nature, noted here and there in the work of Belaid, in Lwali n udrar in particular. Beyond the literary and / or stylistic considerations, I will content myself with describing certain linguistic facts

Le jeu pédagogique au service de l’enseignement/apprentissage de la lecture au cycle primaire.

S’inspirant des théories d’apprentissage socioconstructivistes, cet article présente les résultats d’une recherche menée à l’aide d’entrevue semi-dirigée auprès de cinq enseignantes de la quatrième année du primaire.L’approche qualitative et interprétative adoptée vise à identifier les pratiques pédagogiques d’enseignement de la lecture utilisées par les participantes. L’analyse des données, nous révèle l’impact des pratiques ludiques sur le processus d’apprentissage de la lecture et ce, en intégrant le jeu pédagogique comme technique pédagogique offrant au pédagogue à la fois le moyen d’une meilleure connaissance de l’enfant et celui d’un renouvellement des méthodes pédagogiques en classe de français langue étrangère (FLE)

A Comparative Study of the Evaluation Strategies in the LMD and Classic Systems

إن تطبيق نظام" ل م د" في التعليم العالي في الجزائر مشروع طموح و لا سيما في مجال تعليم اللغات الحية و خصوصا الانجليزية,  فهو يكتسي  إذن  أهمية كبرى في المسيرة التعليمية ة التربوية. مع نظام "ل م د" جاءت دروس لم نعهدها في النظام الكلاسيكي و لا سيما فيما يخص مستوى السنة الأولى. كما يولي نظام "ل م د" أهمية قصوى للتقييم المستمر/التكويني على غير النظام الكلاسيكي، في حين هذا النوع من التقييم إجباري في النظام الجديد ل.م.د ، فهو اختياري في النظام الكلاسيكي. و سؤالنا هنا هو إلى أي مدى يعتبر هذا التقييم ناجعا خاصة عندما يكون الطلبة واعين بمدى تأثيره على نجاحهم في كل مادة نهاية كل سداسي. من خلال هذه الورقة نتطرق إلى عدة نقاط أهمها مستوى الطلبة, نقطة الامتحانات, آراء الأساتذة, المناهج و الوقت المخصص. و للوصول إلى ما نصبو إليه فلقد اعتمدنا على شريحة معينة من الأساتذة ذوي الخبرة في تدريس طلبة السنة الأولى  لقسم الانجليزية في كلا النظامين. هذا و نركز على التقويم الذي يقوم به الأساتذة كأداة جديدة لبلوغ الأهداف المسطرة. في الأخير, فإننا استخلصنا أنه على الطلبة الانتباه أكثر إلى أهمية التقييم المستمر للتمكن من معالجة القصور المرتبط بهذا الأخير.            The implementation of the new system « LMD » in Algerian higher education is an ambitious project .In the field of foreign language and especially in English, it is of great importance to the teaching/learning process. Indeed, the LMD system introduces new courses that are not given in the classic one at the level of first year classes in particular. In addition, it gives more importance to the continuous/ formative evaluation than the classic one does. Whereas the formative evaluation is optional in the classic system, it is compulsory in the new system. The main question here is to which extent is that evaluation efficient in case that the students are aware of its impact on their success by the end of each course. The major aim of this paper is to examine the validity and effectiveness of the “formative evaluation” in the LMD system. To answer the question stated above, the present paper takes the following elements as its basis: the students’ level, exam grades, teachers of systems opinions, the common courses syllabi, and the time allotted. To give credit to our claims, this paper relies on a restricted population of teachers who have the experience in teaching 1st year students of the English language department in both systems LMD and Classic. The study spots the light on the teacher’s assessment of the new testing tool. At the end of this work, we come to the conclusion that students in the first place have to pay much more attention to the importance and validity of the continuous evaluation in order to remedy their deficiencies that are related to the latter

Strengthening of concrete beams by CFRP: Experimental study and finite element analysis

This work presents an experimental study on the mechanical behavior of structural concrete reinforced by carbon fiber reinforced polymer (CFRP). The main purpose of this study is to test the applicability of this method of reinforcement in the beams to improve the behavior of concrete: strength and ductility. An experimental characterization of mechanical behavior by tensile test by three point bending is achieved, namely, the reinforcement of the lower part of the beam (15x15x75) cm3 with composite material, Based on the ANSYS simulation, a model was developed to validate the different results obtained experimentally. The experimental results show that the reinforced concrete offered a great improvement in strength and ductility; in effect an influence directly on the failure mode is observed and then read by the value of strength and ultimate deformation. The tensile bending of beams reinforced by CFRP is more than 295% in comparison with that of non-reinforced beams. The gain maximum of ductility is 247%. The experimental results have been compared with the theoretical models, a good correlation was obtained

The factor influencing the developpement of a digital culture : A case study directions of Ministry of commerce

تهدف هده الورقة البحثية إلى التعرف على العوامل المؤثرة في بناء الثقافة الرقمية وتتضمن الدراسة عرضا للجانب النظري حول دور الثقافة الرقمية و أهمية العوامل المقترحة في بنائها  وجانب تطبيقي يتناول مدى استجابة المنظمة محل الدراسة و المتمثلة في  وزارة التجارة بمختلف مديرياتها المركزية و الولائية  للعوامل المؤثرة التي تساعدها في إرساء ثقافة رقمية و نجاح خطة التحول الرقمي لديها .تم جمع البيانات حول الممارسة التطبيقية لهده العوامل عن طريق استبيان الكتروني تحصلنا من خلاله على 264 إجابة من 35 مديرية ولائية ومن مديريات مركزية تابعة للوزارة، بعد عملية فرز للإجابات اعتمدنا على 216 إجابة قمنا بمعالجتها باستخدام برنامج SPSS والنمذجة البنائية لAMOS. توصلت نتائج الدراسة إلى إبراز  دور الانفتاح نحو التغيير كوسيط جزئي يربط العوامل المقترحة لبناء ثقافة رقمية في حين غاب دور القيادة التحويلية الرقمية كوسيط ثاني حيث من الملاحظ أنه مازال هدا المفهوم غائب في الميدان لكن أثبتنا نظريا نجاعته وأهميته في قيادة التغيير بالمنظمة.This research paper aims to identify the factors affecting to building digital culture. The study includes a presentation of the theoretical aspect about the role of digital culture and the  importance of the proposed factors building a digital culture and an applied aspect that addresses the extent of the ministry’s response in its various central and state directorates to influencing factors that help it establish a digital culture And the success of the digital transformation plan that you strive for, We collected 264 answers from 35 state departments and central directorates of the Ministry After the sorting process, the answers were216, We processed it using a program SPSS and by the structural modeling of the program. The results of the study reached the theoretical side of the field reality through the role of openness towards change as a partial medium linking the proposed factors to build a digital culture while the role of digital transformative leadership as a second medium is absent, it is noted that this concept is still absent in the field but we have theoretically demonstrated its efficacy and importance in driving change Therefore, one of the most important recommendations was the necessity for organizations to respond to the new concepts of managers and employees as a whole

Inspecting a seasonal ARIMA model with a random period

This work proposes a class of seasonal autoregressive integrated moving average models whose period is an independent and identically distributed random process valued in a finite set. The causality, invertibility, and autocovariance shape of the model are first revealed. Then, the estimation of the parameters which are the model coefficients, the innovation variance, the probability distribution of the period, and the (unobserved) sample-path of the period, is carried out using the expectation-maximization algorithm. In particular, a procedure for random elimination of seasonality is proposed. An application of the methodology to the annual Wolfer sunspot numbers is provided

Detection of superparamagnetic nanoparticles for immunoassays

International audienceWe develop a completely integrated Lab-on-Chip (LoC) for easy, rapid and cost-effective immunoassays. The pathogen sensing system is composed of a microfluidic channel surrounded by planar microcoils which are responsible for the emission and the detection of magnetic fields. The system allows the detection and quantification of superparamagnetic beads used for immunoassays in a “sandwich” antigen-antibody configuration. We successfully tested this device with different concentrations of nanoparticles and determine the limit of detection of the prototype. These results are promising and are a step toward the creation of a portable pathogen sensing device

Effect of Natural Pozzolan and Calcined Paper Sludge as Pozzolanic Additions on the Physicals and Mechanicals Properties of Heat Treated Self-Compacting Mortars

The aim of this research work was to investigate the effect of thermal treatment on strength development of self-compacting mortars (SCMs) based on two pouzolanic materials: Natural Pozzolan and calcined paper waste sludge, were used in the binders of SCMs. To evaluate the effect of heat treatment, a serial of the specimens were exposed to room temperature and another serial were exposed to heating regime (at temperature 60°C for a period of 14 h).  The fresh and hardened properties of all mortars were evaluated. the obtained result show that the mechanical strength at 14 days of all mortar treated are almost similar or sometimes better to those not treated mortars tested at 28 days, which reduces the curing time for precast elements

Interval Estimation for Linear Switched System

International audienceIn this paper, the problem of state estimation is investigated for linear switched system, a subclass of hybrid systems. It will be shown that the interval observer is very often exists under moderate conditions at least in discrete time instants from continuous-time measurements. The novelty consists in proposing new conditions of cooperativity for switched systems in discrete time instants, which guarantee errors nonnegativity of interval observation. The efficiency of the interval observers is shown through simulation examples