Université Mouloud Mammeri de Tizi Ouzou (UMMTO): Research Review of Sciences and Technologies
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Performance comparison of hyperbolic paraboloidal shell footing with its flat counterpart
Full text linkWhile traditional flat footings are commonly used in construction, hyperbolic paraboloidal shell footings present potential benefits in load distribution and settlement reduction. The study encompasses two primary aspects: the design of both footing types in accordance with Indian standard practices, followed by a comparative analysis of their performance utilizing finite element methodology. Performance comparison is carried out concentrating on vertical settlement, stress distribution, and the amount of concrete required under centric gravity loads. The hyperbolic paraboloidal shell footing was modeled with curved surfaces, and the underlying soil was treated as nonlinear using the Mohr-Coulomb yield criteria. The amount of concrete required for a hyperbolic paraboloidal shell footing is significantly less, calculated to be 0.61 times that of a flat footing.
A study on post-fire durability performance of concrete
Full text linkConcrete structures are often exposed to fire hazards, which can significantly affect their durability and structural integrity. Post-fire durability assessment is crucial to understanding the residual strength and long-term performance of concrete after exposure to elevated temperatures. Limited research has concentrated on durability attributes, with the majority examining primarily mechanical aspects. We have thus initiated the endeavor. This study aims to evaluate the post-fire durability characteristics of concrete, focusing on strength retention, microstructural changes, and degradation mechanisms. This investigation adapted concrete compositions containing 75% recycled marble aggregate (RMA) to the mix. We exposed the prepared concrete to various temperature conditions, including 200°C, 400°C, 600°C, and 800°C. The study examined the concrete's durability features, including their acid, chloride, and carbonation resistance. This investigation revealed that the fire significantly impacted the mechanical and durability properties of the concrete. The results show that fire, in any temperature environment, significantly reduces both the mass and strength of concrete. This is true regardless of the temperature environment. Regardless of temperature, fire has a greater impact on chloride penetration in concrete. Though it was still higher than concrete mixed at ambient temperature, RMA concrete did better than the reference concrete mix. Limiting chloride penetration in the RMA concrete mixture depends critically on the alumina concentration of RMA
Study on Mechanical and Tribological Characterization of Titanium Diboride (TiB2) Reinforced Al7075 Composites by Taguchi Technique
Full text linkThree distinct titanium diboride (TiB2) weight percentages 3%, 6%, and 9% were incorporated into Al7075-TiB2 composites by stir casting. Al7075-TiB2 composites' wear and mechanical characteristics were evaluated. The microstructural investigation titanium diboride verified the stable interfacial bond between the matrix and reinforcing material as well as the uniform distribution of TiB2 particles. Superior mechanical properties were noted when comparing the 9% TiB2 composites to the 3 and 6% TiB2 composites. The tensile strength was increased by 11.94% for 9% TiB2 reinforced Al composites. Dry sliding wear was measured with pin-on-disc device. Measurements of the samples' wear loss as well as coefficient of friction (COF) showed that the cumulative wear loss for each composite varied linearly with load. As seen by the optical microscope, all specimens within the prescribed tension and sliding distance appear to have oxidative wear on the worn-out surfaces of the wear mechanism. Wear rate is most affected by weight percentage TiB2 (48.43%), followed by load (19.08%), according to the ANOVA. The wt. % of TiB2, at 37.68%, has the biggest effect on the COF, followed by sliding distance (20.54%). Taguchi technique validates the beneficial impact of weight percentage TiB2 on wear loss and COF. The composite reinforced with 9% TiB2 has the finest tribological and mechanical properties
في شعريّة المعنى لدى المتنبّي، أوْ بين بناء القلعة وبناء القصيدة
Full text linkThis brief study seeks to elucidate the poetics of meaning in the poetry of Abu al-Tayyib al-Mutanabbi by analyzing a selected verse that has long captivated our attention. This verse has enticed us to explore the secrets of its artistic uniqueness and the depth of its thematic significance. The reason for this fascination is that, whenever we reflect upon this line with our students in the course of discussing a particular aspect of Al-Mutanabbi’s poetry, a pressing question emerges: Does this verse depict a single agent who builds the fortress of the event with the edge of the sword? Or does it simultaneously suggest the presence of a second agent who constructs the poem with the edge of the word, immortalizing this pivotal historical moment in the life of the early Arab Muslims?To phrase the question more precisely: Does the poetics of meaning in this verse rest on a dual construction? One construction is visible—the physical building of the fortress, representing the historical event that prompted Al-Mutanabbi to praise Sayf al-Dawla al-Hamdani, the architect of the stronghold in reality. The other construction, however, remains hidden within the text, only revealed through meticulous analysis. This second construction is that of Al-Mutanabbi the artisan, who sculpted from language an image of the towering fortress and, in doing so, created a magnificent poem. The verse in question, composed in the Ṭawīl meter, reads: Banāhā fa-aʿlā wa-l-qanā taqraʿu l-qanā Wa-mawju l-manāyā ḥawlahā mutalāṭim("He built it and raised it high while spears clashed against spears, And the waves of death surged turbulently around it.")This verse, in our humble estimation, is particularly worthy of study, as it demonstrates how Al-Mutanabbi distilled poetic meaning from the depths of his verse while simultaneously maintaining the surface-level praise of Sayf al-Dawla. The latter had liberated the fortress from the rule of the foreign military commander al-Damastuq, who had wronged its inhabitants and broken his oaths with them.Most studies of this poem—and of this verse in particular—have focused on the praised figure, Sayf al-Dawla, and his actions while neglecting the true architect of poetic meaning: Al-Mutanabbi the artist. Therefore, this article redirects its analytical gaze toward this dual construction, examining how the act of building is shared between the commander of the army and the master of poetry. Through this analysis, we uncover the interplay of two architectural feats: the construction of the fortress and the composition of the poem
Strengthening of Deficient Drop-in-ends with Near Surface Mounted (NSM) Steel Bars under static and repeated loading
Full text linkThe present research work, presented the results of eight drop-in-ends specimens tested experimentally to investigate the efficiency of the NSM steel bars technique in strengthening the drop-in-ends including internal miss detailing, under static and repeated loading. Two values of shear span/depth (a/d) ratios was considered, namely are 1.0 and 1.5. Several variables were considered including (a/d) ratio, effect of deficient nib reinforcement (by about 40%) and the type of loading. The behaviour has been discussed in terms of cracking load, failure load, cracking pattern, load-deflection curve and failure mode. Results revealed that increasing a/d ratio from 1.0 to 1.5 yielded a reduction in capacity and the corresponding deflection by 33% and 5%.Moreover, capacity reduced by 11% and 5% for the two values of a/d respectively, when the nib steel reduced by (40%).Furthermore, it was found that the strengthening by NSM steel bars resulted in increasing capacity by 15% and 14% for the two a/d ratio respectively. Regarding the repeated loading tests, it was found that capacity and corresponding deflection reduced by 25% and 42% for a/d =1.0 relative to the strengthened specimen and tested under static loading ,while the respective values for a/d =1.5 were 5% and 3%. In addition, it was obtained that the capacity was reduced by 16% when increasing a/d ratio from 1.0 to 1.5
A Multi-Layer Perceptron (MLP) Neural Network Approach for Predicting Pressuremeter (PMT) Test Results in Geotechnical Engineering
Full text linkThis study proposes a hybrid machine learning approach using a Multi-layer Perceptron Neural Network (MLP) to predict soil pressuremeter parameters, leveraging a database of 120 soil samples from the Algeria railway line project. The MLP model demonstrated superior performance, achieving a high coefficient of determination (R² 0.93) and low RMSE, indicating strong agreement between predicted and experimental values. Comparative analysis with multiple regression highlighted the MLP’s efficiency in prediction speed and accuracy, though its "black-box" nature limits interpretability of individual parameter influences. While regression provided explicit equations for variable effects, the study underscores the importance of expanding the database with representative inputs to further enhance predictive reliability. The results support MLP as a robust tool for geotechnical forecasting, balancing precision with computational efficiency
حجاجية البديع في كتاب: (جمهرة خطب العرب في عصور العربية الزاهرة) لأحمد زكي صفوت
Full text linkAl-Badi' (figurative style) was studied in successive times as a verbal adornment whose purpose was to improve and entertain، but it was an incomplete lesson that was clearly mistaken. as it cannot be said about the manifestations of al-Badi' in the Qur'an and authentic poetry that they are Appearances of beauty and entertaining only، but the modern argumentative theory has returned the methods of al-Badi' to the ranks of important speech strategies، in terms of approaching them based on the fact that the process of deviation and choice is always loaded with an intended persuasive meaning. If the traditional Arabic sermon is an oral sermon with a limited persuasive status that requires condensation and focus، then the orator's deviation from the normal level of speech and his choice of the al-Badi' style must carry within it an additional meaning that strengthens the thesis and establishes it in the souls of the recipients، which is what this research attempts to clarify and stand on its truth
السياقات التاريخية والمرجعيات الفكرية للأدب العالمي المعاصر
No full textThis study aims to tracking the evolution of the concept of world literature and its shifts, because it is observed that this concept has known an evolution and expansion since its launching by Johann Wolfgang Goethe in 1827. This evolution allowed to expand the realm of world literature and become no more limited to masterpieces of literature, or centered in western Europe, as the saying of Goethe the openness, without a complex of superiority towards the diverse national literature, which were seen as inferior, in the framework of the colonial theories. This led to the expansion of the concept and the realm of the modern world literature, which acquired a universal nature. What helped in that is that this literature witnessed an evolution in its intellectual and literary references, resulted by the general contexts of the era which witnessed the fall of human civilization, which was reflected literary on most of the modern literary movements
الشعر الشعبي الجزائري بعد الاستقلال (عوائق وآفاق الدراسة)
No full textAfter independence, Algerian folk literature was not spared the political and ideological conflicts that plagued the country. These attempts to impose control over culturally charged literary production, which could be used to delve into individuals and groups in order to dominate them, were carried out by the ruling establishment or by the elite controlling the country at the time. Folk literature did not receive much study, especially given the authorities' prohibition of historical research and their rejection of certain disciplines, such as anthropology and sociology, which could reveal the people's mentality, history, and all their daily practices, including the arts of literary expression. This led to folk literature, and particularly folk poetry—considered the most capable of expression, due to its music and rhythm, which facilitate its memorization—remaining on the shelves or on the tongues of individuals and groups, without serious study according to modern methods that would allow us to delve into it, except for a limited amount compared to the last three decades. This is what I have attempted to clarify in this research
Investigating the effects of aggregate gradations on the compressive strength and the cost of concrete using two proportioning methods
Full text linkOptimizing aggregate gradation in concrete mixtures has an impact on concrete properties such as strength, durability and sustainability. Many aggregate proportioning methods have been proposed to solve aggregate gradation issues. The Tarantula Curve is a recently developed aggregate proportioning technique that can evaluate aggregate gradations and can give insights of the quality of the gradations. Since the Tarantula Curve have been having great success in the United States in producing concrete mixtures with outstanding performances and lower cost, this work aims to validate the gradation boundaries of the Tarantula Curve using local aggregates in Saudi Arabia by measuring the compressive strength and the workability. This work also provides a comparison between the Tarantula Curve method to the ACI 211. The results showed a reduction in the compressive strength and poor workability when the 20% limit is exceeded for the coarse aggregate retained on a single sieve. Similarly, as the limits of sieve sizes 150 µm and 75 µm were exceeded, the compressive strength decreased, and poor workability performance was observed in the mixtures. Harsher mixtures were produced as the 2.36 mm sieve limit was exceeded. It was found that the Tarantula Curve produced mixtures with a 35% higher in compressive strength and 6% lower in cost as opposed to the ACI 211 mixtures. These data and tests provide recommendations and framework for further comparative testing in the durability testing in the futur