Université Mouloud Mammeri de Tizi Ouzou (UMMTO): Research Review of Sciences and Technologies
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Production and Strength Evaluation of Sandcrete Hollow Blocks Using Fine sand and Crushed Periwinkle shell
Get PDFWalls are fundamental in building construction, with sandcrete blocks being the most common unit in Nigeria. Sandcrete blocks are made of natural sand, water, and cement. Due to rising material costs, importation issues, and sub-standard materials that do not meet quality specifications in terms of strength, durability, or composition, there is a need to find cost-effective alternatives. This research explores using Crushed Periwinkle Shell (CPWS) to partially replace fine sand. A 1:12 mix ratio was chosen for its cost-effectiveness and suitability for non-load bearing applications. This mix was tested with 0%, 10%, 20%, 30%, 40%, and 50% CPWS, maintaining a constant water-cement ratio of 0.5. Ninety blocks (450mm x 225mm x 150mm) were molded and cured for 28 days. The compressive strength of seventy-two blocks was evaluated at 7, 14, 21, and 28 days. Blocks with 40% and 50% CPWS had high compressive strength values of 2.55 N/mm² and 2.67 N/mm² at 28 days, within the Nigeria Industrial Standard (NIS) range of 2.5-3.4 N/mm². These results suggest CPWS is suitable for partial sand replacement. Additionally, eighteen blocks were tested for water absorption at 14, 21, and 28 days, showing increased absorption with higher CPWS content but decreasing with curing time
Instability phenomenon at municipal solid waste landfills in Vietnam: Case study at Cam Ly landfill, Da Lat City, Lam Dong Province
Get PDFIn Vietnam, poor management of municipal solid waste (MSW), combined with changes in its physical and mechanical properties over time, increases the risk of instability in landfills. The instability poses significant environmental pollution risks and adversely affects infrastructure, production activities, and livelihoods of people living near these landfills. This study focuses on the Cam Ly MSW landfill in Da Lat City, Lam Dong Province, Vietnam, where the geotechnical properties of MSW and soil layers were determined through both in situ and laboratory tests. The findings showed that MSW typically has low resistivity values ( 30 Ωm), suggesting that geophysical survey is a useful tool for determining the thickness and distribution of MSW, providing valuable data for assessing landfill stability and post-closure planning. The instability type and causes at Cam Ly were analyzed using the Limit Equilibrium Method (LEM) through Geoslope/W software and the Finite Element Method (FEM) through Plaxis 2D software. The type of landfill instability identified is of the slip surface within the waste pile. The main causes of instability at the landfill were steep terrain, inadequate compaction of the MSW, and saturation due to prolonged heavy rain. Research on MSW landfill instability is essential for improving landfill management, reducing environmental impact, and safeguarding nearby communities
Analysis of the inelastic lateral - torsional buckling resistances of steel truss members with global and local imperfections
Get PDFThe local and global imperfections of I-shaped steel beams are known to significantly impact the load-carrying capacity of the structure. This is particularly critical for structures subjected to heavy loads, where these factors must be meticulously controlled to prevent potential failures. Therefore, the objective of this project is to describe a numerical analysis that was conducted to evaluate the influence that initial global and local flaws have on the inelastic buckling resistances of steel truss members that are used in steel bridges. These numerical studies are based on Abaqus, and they have been validated quite well against the data that are now available. After that, the numerical models are utilized in order to assess the inelastic buckling resistances of the system, taking into consideration four distinct sorts of initial global and local imperfections which are feasible. The numerical results are compared to the standard evaluations, which are also examined and evaluated. In addition, parametric investigations of the impact of the thicknesses of the web and flange on the inelastic buckling resistances are carried out as part of the current research. The strengthening techniques assessed in this research can serve as a foundation for engineers to implement in actual steel beam structures
Finite Element Analysis of RC Beams Retrofitted and Strengthened with CFRP
Get PDFThis study aims to develop a finite element model for accurately predicting the behavior of RC beams retrofitted and strengthened with CFRP strips. Two types of CFRP layout are modelled, CFRP wraps at the bottom without any anchorage, and CFRP strips with CFRP wrap as anchorage. The developed numerical models are validated by experimentally testing RC beam models for four-point bending. The concrete damage plasticity model is used for introducing non-linearity in concrete. The non-linear tensile and compressive parameters are taken from the ABAQUS manual specifications. The interface between the CFRP and RC beam surface was replicated using a perfect bond between the two. The results show that the developed numerical model accurately predicts the strength of retrofitted and strengthened beams. Though numerical models show higher initial stiffnesses and cracking load, especially in the case of a retrofitted specimen, where the initial stiffness is as high as 75%
مرجعيات التخييل التراثية في شعر ابن فركون الأندلسي
Get PDFThis study aimed to reveal the extent of textual interdependence in the Diwan of the poet Ibn Farkun Al-Andalusi that shows the vast culture he enjoys, and the impact of this culture on his innovative poetic image, through the presence of absent texts and their various topics, whether religious, poetic or historical, and their ability to provide the new meaning, the research tried as much as possible to search for the components of the poet's imaginary texts and their connection to the moral, pictorial and rhythmic aspects, and the impression they left in the mind of the reader. The poet Ibn Farkun's invocation of many texts is to revive authentic ancient texts by overturning their meaning and presence to invoke a new meaning intended by the poet at the moment of poetic saying or transferring it with its original historical significance as a real document that is not fake, as most of his textual comments revolved in support of his ideas and significance
Multilingualism as a Key Factor Towards a Global Understanding: Case of CEIL Learners in The Departement of Foreign Languages
Get PDFPeople over the world used to get into contact and open discussions using distinct languages as media of communication. Consequently, the need to be fluent in more than one language arises to facilitate interaction between the participants. This paper tries to discover how does multilingualism facilitate intercultural dialogue between people from different cultural backgrounds and the main consequences of cultural and linguistic items exchange. To do so a set of informants were asked some questions to assess and discover the Mysteries of bi-communication between the two blocks, then, the results were analysed qualitatively and quantitatively . The results revealed that multilingual proficiency facilitates intercultural dialogue and decreases conflicts, ethnic and racial prejudice between different groups
Attachment Theory: Understanding the Impact of Early Relationships on Adult Life
Get PDFAttachment Theory, proposed by John Bowlby, emphasizes the importance of early emotional bonds between infants and their primary caregivers. This paper explores the key findings and insights of Attachment Theory and its significance in understanding the impact of early relationships on adult life. Secure attachments formed in early life provide a secure base for individuals to explore the world and establish positive relationships throughout their lifespan. In contrast, insecure attachment styles may lead to challenges in forming and maintaining healthy connections and can impact mental health outcomes. Interventions play a crucial role in promoting secure attachments and fostering positive changes in attachment patterns. Early interventions focus on parental support and nurturing environments, while school-based and adult interventions target social and emotional skills to enhance well-being. Recognizing the link between early attachments and adult life is vital for promoting emotional health and fostering fulfilling relationships
الاغترابُ في التراث العربي؛ أبو الفرج النهرواني وأبو حيّان التوحيدي نموذجيْن
No full textThis article sheds light on the Alienation phenomenon and its manifestations in Arab heritage through examples from the works of Abū al-Faraǧ al-Nahrawānī and Abū Ḥayyān al-Tawḥīdī. Upon examining the texts of these compositions, one can observe how the authors, when given the opportunity, readily expressed their perspectives on this experience and their positions towards it, along with the various and diverse reasons that contributed to its prominence in their writings. Therefore, this article seeks to highlight the manifestations of this phenomenon, and to reveal, through precise examples, the underlying reasons behind the authors' sense of alienation and how they dealt with it
Comparative analysis of corrosion mass loss of SKK490 and Q345 steel pipe piles in marine conditions
No full textVietnamese seawater, characterized by high chloride concentrations, presents unique challenges for corrosion in steel materials used in marine environments. This study conducts a comparative analysis of corrosion-induced mass loss in SKK490 and Q345 steels, commonly employed in steel pipe piles for coastal and offshore structures, under simulated Vietnamese seawater conditions. Accelerated corrosion tests were carefully designed with controlled factors, including temperature, humidity, and chloride concentration, using a simulated seawater solution containing 3.5% NaCl to replicate real-seawater conditions. Steel samples were partially immersed and connected to an external power source to accelerate the corrosion process over duration of 72 to 240 hours. The results show that Q345, containing protective elements like Nb, V, and Ti, exhibits better corrosion resistance, with a corrosion rate 1.32 times lower than SKK490. The findings underscore the need for material selection prioritizing corrosion-resistant steels or the application of protective measures such as coatings or cathodic protection. Additionally, the research provides valuable data for optimizing the design and durability of marine infrastructure in Vietnam. Future research should validate these results through long-term field studies and explore advanced anti-corrosion technologies
التّاريخانية الجديدة: تاريخيّة النصّ ونصيّة التّاريخ.
Get PDFIn this article, the researcher deals with the definition of a literary critical activity that emerged in the eighties of the twentieth century, and received great interest in the literary and critical circles, but it did not receive much attention in Arab criticism, so studies on it remained scarce, hence this article came to try to define this critical activity, and highlights Its intellectual references, and explains its most important procedural concepts contained in the books of its pioneers, especially those of its first pioneers Stephen Greenblatt