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MECHANICAL AND DURABILITY PROPERTIES OF GEOPOLYMER CONCRETE – A REVIEW
Get PDFOwing to the ongoing increase in human population, there is a need for more construction projects including residential buildings and other amenities. Concrete is by far the dominant material used in construction and cement is a main ingredient. Cement manufacture is an energy intensive process and emit large amounts of carbon dioxide into the atmosphere. A reduction in the amount of cement used in construction is greatly beneficial. The use of geopolymer or alkali activated materials can serve this purpose as it attempts to totally replace cement in concrete. Geopolymers are materials that consist mainly of silica and alumina materials and activated using alkali such as sodium silicate and sodium hydroxide. This paper attempts to review recent articles on the production and properties of geopolymers and alkali activated materials. Different hardened, structural, and durability properties are studied. These include; compressive strength, flexural strength, modulus of elasticity, ultrasonic pulse velocity, shrinkage, expansion, creep, weight loss, carbonation, sulfate, and corrosion
RELIGIOSITY AND SUBJECTIVE WELL-BEING IN THE ARAB CONTEXT
Get PDFThis is a quick review of Ahmed Abdel-Khalek’s seminal collection of studies on religiosity and psychology, entitled Religiosity and Subjective Well-being in the Arab Context, publish in 2018 by Cambridge Scholars Publishing, UK. The review gives a quick introduction to the topic and proceeds to describe the contents of the work
MEMORIES, A PROCESS OF RESILIENCE IN THE FACE OF CAPTIVITY
Get PDFResilience is the ability to withstand adversity, trauma, stress, and other problems such as depression, family problems and difficult situations in order to be able to survive regardless of the types of shocks suffered. In his novel, Tous les hommes n’habitent pas le monde de la même façon (All men do not inhabit the world in the same way), the French writer Jean-Paul Dubois (Goncourt price-2019) narrates the story of Paul Hansen, locked down in Montreal prison where he shares a 6 square meters cell with Patrick Horton, convicted for murder. Paul Hansen passes time recalling the greatest moments of his life and conversing with ghosts from his past. Remembering the past in this way, helps him to resist and to become more resilient. He escapes his present to fantasize a world where he travels from Toulouse to the North of Denmark, to Skagen, passing through the North of Canada. But how does the narrator explain Paul Hansen\u27s resilience? How memory become imperative does to escape one\u27s present? How do memories become a self-healing tool? This paper will explore the possible answers to these questions as depicted in the novel
ROLE OF 3D PRINTED GREEN WALLS IN HEALING ARCHITECTURE
Get PDFThree-dimensional (3D) printing has become a fundamental issue in modern global technology, touching practically every element of modern human life.Three-dimensional (3D) printing (also known as additive manufacturing) is an advanced manufacturing technology that can autonomously manufacture complicated shape geometries from a 3D computer-aided design model without the use of equipment or fixtures.However, there is a friction between traditional designs and the rise of 3D printed technology when it comes to architectural healing approaches, and this adaptability is hurting human healing tactics that are dependent on the relationship between space and environment.Due to its capacity to create products in a wide range of materials rapidly and at a lower cost, additive manufacturing is having a significant impact on production in a variety of areas. Even though it encompasses a wide range of techniques and applications, additive manufacturing (AM) may be described as a system for converting solid model data from a computer-based model into a physical prototype by the incremental addition of material via layer superposition. Therefore, this research aims to examine the 3d printed green walls as new proposed design elements that can upgrade the natural healing architecture. To achieve this goal, the study begins with a literature review that includes scientific methodology based on principles that assist architects dealing with advanced tools in transforming their intentions from digital to analogue means as part of a controlled system intended to innovate design and construction principles of the use of 3D printed green walls. It will also assist in the quest for a concept design that confronts the regeneration of a new spatial delineation ideology
ASSESSING THE INFLUENCE OF OVERWEIGHT AXLES ON RUTTING LIVES IN FLEXIBLE PAVEMENTS USING PARAMETRIC SURVIVAL ANALYSIS
Get PDFThe existence of rutting or permanent deformation on flexible pavement layers has always been a concern that negatively affects the performance of roads by reducing the lifespan of pavement structure and by posing a safety risk for vehicles over the road. Traffic overloading is one of the primary factors that accelerates the deterioration of flexible pavement. This study aims to determine the time to failure of the flexible pavement structures associated with rutting, to indicate the most significant factors affecting rutting, and to assess the influence of overweight axles on pavement rutting life using parametric survival analysis. The data used in this study are extracted from the LTPP program. The outcomes provide researchers and agencies with a good knowledge of the relations between several predictors including overweight axles and pavement performance and hence increase the ability of pavement to continue functioning properly over the design lifetime. The results indicated the factors that have a significant effect on pavement rutting life. Also, the results revealed that a 1% increase in the percentage of overweight axles can be related to a 16.24% increase in the hazard rate of rutting failure. Moreover, the survival time of rutting life can be reduced by up to 63% with the increase of the percentage of overloaded axles from 0% to 20%
EFFECT OF HOT WEATHER CONCRETING ON THE MECHANICAL AND DURABILITY PROPERTIES OF CONCRETE-A REVIEW
Get PDFNowadays, hot weather is an essential motivator that leads concrete to lose its special characteristics. The high loss of moisture by evaporation and rapid hardening encourage the cracking potential and placement operations. The fresh mixed and hardened concrete tend to be damaged due to several conditions such as: high concrete temperature, High ambient temperature, low relative humidity, and high wind speed. These circumstances accelerate the rate of moisture loss and cement hydration. This article briefly reviews hot weather concreting problems precautions, and curing methods and also discusses the role of incorporation SCMs in reducing the temperature of concrete and enhancing its mechanical and durability performance
STRUCTURAL AND MAGNETO CONDUCTIVITY STUDIES OF NIO/SMBA2CU3O7-Δ SUPERCONDUCTING COMPOSITE
Get PDFIn this work, we investigate the effect of NiO nanoparticles\u27 addition on the structure, superconductivity, and magneto conductivity for the SmBa2Cu3O7-δ phase. Composite nano/superconductor of (NiO)x/SmBa2Cu3O7-δ (0.00≤x≤0.12 wt.%) were prepared by conventional solid-state reaction technique and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The orthorhombic structure was maintained whereas the lattice parameters showed unsystematic variations with the NiO nanoparticles addition. The superconducting transition temperature Tc, determined from electrical resistivity measurements, showed an enhancement with x up to 0.04wt.% followed by a reduction with higher NiO additions. The Aslamazov–Larkin (AL) model was employed to analyze the magneto conductivity. The model allowed to determine the coherence lengths along c-axis ξc(0) and along ab plane ξab(0). Moreover, the anisotropy parameter Г increase with the increase of NiO nanoparticles addition
VALIDATION OF THE FACTOR STRUCTURE OF THE PARENT-ADOLESCENT RELATIONSHIP SCALE IN THE INDIAN CONTEXT
Get PDFParent-Adolescent Relationship (PAR) gets transformed during adolescence, and there is a significant relationship between the adolescent\u27s adjustment and quality of this relationship. A loving and caring relationship full of acceptance with parents offers a health-oriented atmosphere for the growth of the child\u27s abilities in multiple ways. The research findings indicated that the quality of Parent-Adolescent Relationship (PAR) associates with a broader range of positive outcomes, including emotional and mental Well-being, adjustment with the environment, and social competence. The present study was designed to adopt a Parent-Adolescent Scale, which examines the parent-adolescent relation among adolescents of India. In the present study, 13 items from the Parent-Adolescent Scale 21, developed by Husseini et al. (2016), were translated in the Hindi language and adopted in the Indian context. A total 1000 adolescent students from different Hindi speaking states of India responded to the PARS13. An Exploratory Factor Analysis and a Confirmatory Factor Analysis were performed to test the factorial structure of the PARS13, and the internal consistency of the scale was studied. The results supported scale multidimensionality. The obtained Cronbach’s alpha revealed satisfactory internal consistency with a value of 0.82. Based on the psychometric properties obtained, it is concluded that PARS13 is a reliable measure to assess adolescents\u27 parent-adolescent relationship in India
THE EFFECT OF LEADER-MEMBER EXCHANGE, CO-WORKER COOPERATION AND LOCUS OF CONTROL ON EMPLOYEE OUTCOMES IN LEBANESE SMES: PERCEPTIONS OF POLITICS AS A MEDIATOR
Get PDFPurpose – This study aims to investigate the nature of the relationships between three variables (leader-member exchange, locus of control and co-worker cooperation) and two employee outcomes (job satisfaction and turnover intention). It also examines whether these relationships are mediated by perceptions of politics.
Design/methodology/approach – Survey data was obtained from 300 employees from Lebanese SMEs located between Tripoli and Beirut. Mediation was tested using Baron and Kenny (1986)’s framework.
Findings – Results revealed that leader-member exchange and co-worker cooperation are positively related to job satisfaction and negatively related to turnover intention. Locus of control, on the other hand, is negatively related to job satisfaction and positively related to turnover intention. Also, perceptions of politics partially mediated some of these relationships while it fully mediated others.
Originality/value – This study extends research on organizational politics to Eastern cultures by examining SMEs in a country like Lebanon. It also attempts to explain inconsistency in the literature by adding a mediating variable to the model of determinants and employee outcomes. That is, it suggests that the effect of leader-member exchange, locus of control and co-worker cooperation on outcomes is through the mechanism of perceptions of politics
AUDIT REPORT LAG: DO COMPANY CHARACTERISTICS AND CORPORATE GOVERNANCE FACTORS MATTER? EMPIRICAL EVIDENCE FROM LEBANESE COMMERCIAL BANKS
Get PDFThe objective of this study is to investigate the determinants (company specific characteristics and corporate governance factors) of audit report lag (ARL) in a developing country, namely, Lebanon. This paper adds and contributes to the limited literature that investigated the determinants of ARL in the developing Middle East countries through focusing on the Lebanese context. The study is carried out depending on a sample of Lebanese commercial banks operating in Lebanon, covering the period from 2012 to 2017. The researchers used the multiple regression analysis to examine the impact of the explanatory variables on ARL. The results show a significant relationship between ARL and each of bank size, leverage, board independence, board diligence, audit committee (AC) independence, and AC diligence. The regression outcomes reveal that banks with longer ARL are smaller, have higher leverage, their boards and ACs are less diligence, their boards are more independent, and their ACs include less independent and non-executive members