Showing 1177 results for Ahmad
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Well-being includes phenomena such as mental health, life satisfaction, positive attitude and feeling happiness. The present study deals with the relationship between language and well-being and claims that well-being factors are expressed in the words of the language. For example, the happiness factor in a language is reflected by certain words such as happy, happiness and satisfied. The theoretical framework of the present study is ecolinguistics. The method is corpus based. The data is extracted from the research of Secretariat of Emotional Intelligence of Tehran Education in 2017. In this study, the well-being status of 1095 high school students, the first and second period, girls and boys, public and private of District One of Tehran have been evaluated. The students' responses to the question about well-being criteria are the base of the present study. The corpus consists of 1161 words with a frequency of 35,455. The content words associated with the five Well-being factors of engagement (occupation and entertainment), perseverance, optimism, connectedness and happiness were extracted in the framework of the semantic map of Jiaqi Wu et al. (2017), by using top-down method. They were analyzed using Excel and SPSS soft-wares. Some examples of the words that represent the well-being factor of happiness are: “relaxation, facilities, happy, healthy, fun, health, happiness, excellent, pleasant, relaxed, happy, satisfied, faith, satisfaction, enjoyed, happiness, joy, and fun”. The research findings show 6845 words of the corpus (about35.7%) are related to well-being, and there is a significant relationship between well-being factors and produced words
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Language teacher professional identity refers to each individual’s understanding of their identity, helping them prepare for their professional lives and is affected by different factors. This study thus explored the reasons why language teachers chose this profession, their perceptions of the notion of language teacher professional identity (LTPI), the influential factors in the formation or change of professional identity, and the contribution of communities of practice. A 37-item questionnaire along with five open-ended questions was developed and administered to 109 English language teachers studying Teaching English as a Foreign Language (TEFL) at Iran University of Science and Technology (IUST). The outcome of the study revealed that language teachers perceived their professional identity mostly related to students, self-knowledge and awareness, and practice into knowledge. They stated that students, context, and disciplinary knowledge could greatly cause constant change in the progression and formation of professional identity. The research could shed more light into the improvement of language teachers’ professional development and teacher education programs.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
The present article aims to analyze six contemporary short stories based on Halliday and Matthiesen's systemic functional grammar framework (2014). In functional grammar, the message and textual meaning of clauses will not be revealed to the reader without identifying the topical themes and the discourse factors influencing to highlight them. Thus a perfect interpretation of the message will not be obtained. The study answers the question how the thematic structure in clauses helps highlight and convey the author's messages. The study hypothesis is: the thematic structure conveys the author's message by highlighting the topical themes by means of syntactic tools. the study corpus contains six contemporary short stories, comprising 3736 clauses. The descriptive- analytic method were used to analyze all the 3736 clauses based on thematic structure in textual metafunction. The data analysis showed that in unmarked clauses the topical themes were used in their natural place as subjects, mostly being participants to preserve and maintain the topic. However, when there were good discourse reasons such as new events, topic change and certain meaning, mostly preposed adjuncts were used as topical themes in marked declarative clauses. while the process was used as topical theme in imperatives to show the participants social status. Therefore, the readers by using the thematic structure and identifying the topical themes can understand the author's intended textual meaning and his message in unmarked and marked clauses.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Every country has different languages. Some are standard, while others are non-standard. This research looks at how often people in Iran use standard and non-standard language. It also looks at other factors like age, gender, education, occupation, and income. It also looks at how people feel about different language groups. The data were collected from 314 people in 10 Iranian ethnic groups living in Tehran. They were analyzed using SPSS software and Foucault's theories of power and discourse silence. The results show that people over 50 use their native language or dialect more because they have more social power. Men have replaced non-standard language with standard language. As education level rises, people use less non-standard language. Non-criteria type is more common among retirees than other occupations. Those with a strong financial status have replaced non-criteria type with the criterion type. Those with a weak financial status have the most non-criteria type speech silence. Speakers of languages with strong attitudes toward language use are less likely to speak up in many social situations. They often use non-standard language instead of standard language.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Today, the news media has a momentous role in shaping public opinion and social developments. Journalistic translation thus follows guidelines and standards in order to convey the message and objectives of its source material. The translation of the political press discourse surrounding the US and international sanctions on Iran is particularly sensitive, due to its high potential in impacting international relations and political affairs.
The objective of our research is to highlight the importance of methodologies used for the translation of political press discourse. For this purpose, we have analyzed two important news articles related to the aforementioned sanctions. First, we conduct a critical analysis of the political discourse, based on Van Dijk's model, and then we perform a translational analysis, based on Antoine Berman's views. Finally, we explore the different types of modifications made by translators, as well as the efforts made to adapt the news to the media’s political ideology. In line with Van Dijk's opinions, we have shown that there is a close relationship between the ruling policy (power) and the press discourse (media), in shaping the public perception of policies and events at mass scale. We demonstrate how subtle deletion, change, and intensification is strategically used in jo urnalistic translation, in line with their desired discourse functions to achieve political goals.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Review and analysis of verbal thought prevailing over syntactic principles are important phenomena in Arabic Linguistics; a thought which as a general principle dominating syntactic science seems trivial comparing to that general issue. From a long time ago, a syntactic science which grasps the structure of Arabic language has occupied the mind of old and contemporary linguists of this field of thought; a science which seems essential for logical understanding of Arabic language structure. Among the fourfold syntactic principles, review and analysis of this verbal thought regarding the issue of “audition”, which is another evidence of syntactic principles such as “analogy” and “consensus”, persuades us to carry out this study. The study focuses on the viewpoint of two old and contemporary linguists and scholars of syntactic principles named al-Suyuti from the ninth century and Tammam Hassan of the contemporary time. Having a descriptive-analytical approach, existing resources and lingual data were reviewed. The results show that regarding the audition’s evidence and one of its resources which is the issue of citing Quranic readings to regularize syntactic rules, al-Suyuti of the ninth century, considering his religious concern, accepts citing all kinds of readings by considering “اﻟﻘﺮاءه ﺳُﻨﺔٌ ﻣُﺘَّﺒَﻌَﺔٌ ولا تُخالَف” but Tammam Hassan accepts citing readings by considering the condition of “مستندهٌ بالأسانید المعتبره””. On the issue of citing the Prophet’s hadiths, al-Suyuti accepts the views of al-Shatibi which are conditioned but Tammam Hassan believes that citing hadiths quoted by meaning is acceptable for regularizing syntactic rules because they
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Teacher reflection and self-efficacy beliefs are two important teacher characteristics that influence different aspects of teaching jobs. The relationship between these two constructs is important, but the previous research has focused on the effect of reflection on self-efficacy. This mixed-methods study aimed at assessing the interrelationships between reflection and self-efficacy through surveying 330 Iranian English language teachers in the quantitative phase and interviewing 15 teachers in the qualitative phase. The quantitative data were analyzed through a Partial Least Square approach and the qualitative data through a conventional content analysis. Results show the two variables are closely interwoven, but reflection components were better predictors of self-efficacy. Metacognitive, cognitive, and affective reflection were significant predictors of self-efficacy and its components, but critical reflection did not predict any aspect of reflection. Efficacy for classroom management could predict practical and cognitive reflection, and efficacy for student engagement could predict practical, affective, and critical reflection. These findings imply that metacognitive, affective, and cognitive reflections need to be encouraged in English Language Teaching preservice and inservice teacher education programs, and workshops need to be enriched and focus on practical teaching issues and classroom management strategies, and learner engagement techniques.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Mehdi Sahabi s’est essayé, pendant des années, à l’atelier de Proust et ce faisant, il a atteint à un certain degré de mûrissement. En traduisant A la Recherche du Temps, il a voulu faire œuvre, comme dit Antoine Berman. Les Plaisirs et Les Jours, livre d’un jeune auteur qui demande reconnaissance, préfigure déjà La Recherche, malgré la différence compositionnelle et thématique entre les deux ouvrages. Dans cet article, en nous basant sur les procédés techniques de la traduction énumérés et exemplifiés par Vinay-Darbelnet dans leur théorie de La Stylistique comparée, nous cherchons à analyser le processus de la traduction de ce recueil proustien. L’objectif est de connaître d’abord la méthode de traduction dee Sahabi et la manière dont il a procédé, et de savoir ensuite si la théorie appliquée est efficace dans la lecture d’un texte littéraire traduit. Les premier et second objectifs, pour être atteints, ont besoin de la mise en présence des deux textes et de l’explication de l’opération traduisante. A priori, les projets traductifs de Sahabi semblent ciblistes et orientés vers le lecteur, mais il est le traducteur des choix inattendus et peut nous surprendre. Par ailleurs, l’applicabilité de cette théorie linguistique au texte proustien déterminera son efficacité dans la critique de la traduction littéraire.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
The present research study aimed to investigate the pragmatic awareness, attitudes, and practices of nine upper secondary English teachers in EFL (English as a Foreign Language) classrooms, with a focus on the intercultural aspects of the subject. Using a phenomenological methodology, the study conducted nine semi-structured interviews with English teachers of upper secondary students. Teachers demonstrated a high level of awareness of pragmatics, particularly when presented with pragmatic input based on syllabi formulations. The awareness suggested a recognition of the importance of pragmatic competence in language learning. Teachers incorporated pragmatics into their teaching methods. Pragmatics was used as a tool for fostering metacognitive conversations about language, helping students understand the appropriateness of certain phrases or words. Teachers aimed to make students aware of why people communicate in certain ways. The understanding of the reasons behind communication choices was deemed important for both teachers and students. Teachers perceived the intercultural dimensions of the English subject as crucial. Issues such as monocultural teaching groups, filter bubbles, and the rise of difficult conversations were highlighted. Teachers found using students' first languages to be an important tool for understanding and scaffolding their learning of English. The incorporation of pragmatics in the EFL classroom not only benefits language development but also serves as a facilitator in developing an understanding of other people. The study suggested a link between pragmatic awareness and intercultural competence in language teaching.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Explaining the nature of metaphor and its role in language has always been a controversial topic in the fields of linguistics, philosophy of language, rhetoric, and so forth. In metaphor analysis, these fields often converge in an inseparable manner. Donald Davidson, a 20th-century philosopher, is one of the influential theorists in the Philosophy of Language and the Theory of Meaning. His views on the essence and role of metaphor in language bear significant similarities to the ideas of al-Jurjani, a prominent 5th-century Hijri literary scholar. This research aims, through a descriptive-analytical method and a comparative approach, to examine the intersection points of Davidson’s and al-Jurjani’s theories, with one addressing metaphor from a philosophical and linguistic perspective and the other from a rhetorical standpoint. For this purpose, Davidson’s essay "What Metaphors Mean?" is used as the basis for reviewing his theories on metaphor. Al-Jurjani’s views are analyzed with a focus on "Dala'il al-I'jaz." This study yields results in three areas. The first, identifies similar aspects in the two theories, indicating that both theorists reject the idea of metaphor being merely a shortened simile. They also critique the notion of "metaphorical meaning," emphasizing that the meaning of a metaphor cannot be reproduced in any form other than the metaphorical one itself. The second area involves finding complementary aspects in the two theories, considering Davidson's philosophical stance and al-Jurjani's rhetorical position. The third area elaborates on the connection between al-Jurjani's direct views on metaphor and the ideas indirectly inferred from theory of Construction.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
For decades, both researchers and EFL learners have been interested in native-like pronunciation. While extensive research has delved into a variety of pedagogical approaches and the complexity of English phonology, an unanswered question is how high-proficiency EFL learners achieve the elusive goal of native-like pronunciation in spoken English. To this end, this multiple-case study aimed to explore the multifaceted strategies employed by 15 high-proficiency EFL learners who had mastery in pronunciation and were selected using the maximum variation sampling method. Data was gathered through the use of diaries and in-depth semi-structured interviews. The data was analyzed with NVivo software version 10, and two main themes were extracted: teacher-directed (TD) and self-directed (SD) pronunciation learning strategies. Regarding the TD strategies, some participants (46%) acknowledged actively engaging with structured tasks and assignments facilitated by teachers. They highlighted the role of in-class (36%) and out-of-class (64%) activities in their journey to master pronunciation. The SD strategies were reported by about half of the participants (54%) in their quest for pronunciation mastery, which included self-talk (48%), podcast listening (29%), shadowing (12%), and reading aloud (11%). This study contributes valuable insights into relevant literature and offers evidence of the interconnectedness of TD and SD strategies in pronunciation improvement. The findings have several implications for further research or practice about pronunciation mastery.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Abstract
The phonetic variable, encompassing various aspects of sound production such as articulation, accurate pronunciation, phoneme delivery, and coordination in pronunciation, is a critical factor in enhancing the speaking skills of non-Arabic language learners. This variable provides a precise foundation for the correct articulation of words and sentences, thereby playing a fundamental role in empowering learners to communicate effectively. Play, as a unique educational tool, offers authentic conversational contexts and diverse linguistic styles, making it a powerful medium for strengthening this variable.This study aims to evaluate the effectiveness of virtual drama instruction in enhancing the phonetic variable, using Tawfiq al-Hakim's play Her Majesty as a case study. The research employs a mixed-method approach, combining descriptive-analytical methods for theoretical explanation and quasi-experimental methods for teaching, testing, and evaluation. The statistical population consists of fifth-semester undergraduate students of Arabic language at public universities in Iran, particularly the University of Tehran, divided into control and experimental groups. Data for the research, collected during the 2021–2022 academic year, were analyzed using SPSS software through statistical methods, including descriptive statistics (mean and standard deviation) and inferential statistics (Kolmogorov-Smirnov, Levene, and covariance tests). Findings indicate that teaching drama significantly improves the phonetic variable among students, demonstrating a positive impact of this educational method on enhancing pronunciation accuracy and articulation quality in language learners.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
This study investigated the role of naiveness and expertise in noun phrase complexity of academic texts as measured by noun phrase pre- and postmodifiers. To this end, four corpora of the abstract sections of Master of Arts (MA) theses (to represent expert academic writing) in applied linguistics authored by English native and Persian writers were constructed. Noun phrase modifiers were identified thorough automatic grammatical taggers (Stanford Core NLP) and noun phrase extraction tools. Findings revealed that novice and expert academic writers differed significantly in the use of some of the noun phrase postmodifiers. However, the difference between native and nonnative academic writers in the use of premodifiers was not large enough to show statistical significance. Findings support the view that the most important distinction in advanced academic writing is not between native and nonnative writers, but between expert (senior) and novice (junior) ones. Pedagogical implications of the findings are also discussed.
Volume 0, Issue 0 (Articles accepted at the time of publication 2024)
Abstract
Second language (L2) learners often struggle with the acquisition of the present perfect tense. However, input flooding and meaning-focused reading have shown some promise in helping L2 learners acquire an L2 more easily. In light of this, we designed an experiment to investigate whether input flooding and meaning-focused reading activities could help L2 learners comprehend and produce the present perfect tense. To this end, three intact classes from a high school were selected, and they were randomly assigned to three conditions: an input flooding-only condition, a meaning-focused reading plus input flooding condition, and a control condition. The results of the statistical analyses using one-way between-group ANOVAs indicated that incidental exposure through input flooding and meaning-focused reading activities enhanced both the target form’s comprehension and production. The results further demonstrated that meaning-focused reading activities combined with input flooding yielded a more facilitative role in enhancing both the comprehension and production of the feature than input flooding-only did. These findings suggest that incorporating implicit procedures, including input flooding together with meaning-focused reading activities, has the potential to not only help L2 learners comprehend the present perfect tense but also produce this linguistic form. Consistent with the Form Meaning Use (FMU) Model and the noticing hypothesis, our findings encourage the inclusion of structured exposure in language programs by language teachers and curriculum developers to hone L2 learners’ grammatical competence.
Volume 0, Issue 0 (ARTICLES IN PRESS 2024)
Abstract
Rural handwoven carpet weavers, particularly in the context of handmade silk carpet production, grapple with significant challenges concerning recognizing all stakeholders and establishing timely connections. These challenges have a substantial impact on the adoption of innovation in carpet production and the overall enhancement of productivity. This research was conducted to scrutinize the communication network of carpet weavers within the Knowledge and Innovation System (KIS) of handmade silk carpet production in rural areas. Data were gathered through interviews with 270 rural households in Zanjan province, specifically in the Tarom, Khodabandeh, and Zanjan counties, utilizing a structured questionnaire. Social Network Analysis (SNA) in UCINET was employed to examine the interactions among these actors, and graphical representations were created using Net Draw. The results revealed that the network's density varied across different levels, showing weakness in some cases, moderate strength in others, and strong connections in select instances. The connections of carpet weaving families with other actors within the KIS were predominantly localized. Among these families, those utilizing the home-based wage production method exhibited the most extensive interactions. The individuals designated as "FMs" (likely referring to family members) and "WNVKRs" (possibly local experts) demonstrated the highest degree of connection and influence within the network of weavers' interactions
Volume 0, Issue 0 (ARTICLES IN PRESS 2024)
Abstract
The Ministry of Agriculture Jihad in Iran implemented contract farming (CF) for wheat in 2021 to address marketing issues. This study compares agricultural sustainability for farmers participating in and not participating in CF. Agricultural sustainability was assessed by applying a combined index approach that considers economic, social, and environmental dimensions. The required data came from 620 wheat farmers in Golestan province, sampled using the multi-stage randomization technique. The data were evaluated using exploratory factor analysis (EFA) and clustering methods. The findings indicated a significant difference in the performance of economic and environmental sustainability dimensions between two groups of wheat farmers. For the participants, 14.2% were deemed unsustainable, 47.7% were considered partially sustainable, and 38.1% were classified as sustainable. For non-participants, the figures were 38.7%, 47.7%, and 13.5%, respectively. Therefore, it is suggested to provide more opportunities for participation in this program and expand it to other key crops. Additionally, authorities should provide more information about the benefits of the CF plan.
Volume 0, Issue 0 (ARTICLES IN PRESS 2024)
Abstract
Controlling insect pests through nano-based formulation of chemicals is one of the newly applied methods in IPM programs; however, the probable side impacts of nano-pesticides on non-target organisms need to be evaluated. In this study, deltamethrin and matrine were encapsulated with polyethylene glycol (PEG) and chitosan (Cs), respectively, and their toxicity were investigated against Habrabracon hebetor Say using the contact method. According to the scanning electron microscopy (SEM), spherical nanoparticles for both formulations were observed. The average hydrodynamic nanoparticle diameters for deltamethrin and matrine were 65 and 70.5 nm. The LC50 values were 254.48, 334.90, 760.31 and 1021 mg L-1 in PEG-encapsulated deltamethrin, commercial deltamethrin, Cs-encapsulated matrine, and commercial matrine, respectively. Exposing to the LC30 of the commercial and nano-encapsulated deltamethrin significantly prolonged the total pre-adult period. The adults of H. hebetor in PEG-encapsulated deltamethrin treatment had the lowest longevity compared to other treatments and control. Furthermore, the sublethal exposure to the PEG-based nanoformulation of deltamethrin and commercial deltamethrin resulted in a significant reduction of the intrinsic rate of natural increase (rm) (0.159 and 0.168 day-1, respectively). Same trend was observed for the gross reproductive rate (GRR), net reproductive rate (R0), and finite rate of increase (λ) of the parsitoid. Our findings indicate that the negative side effects of commercial and nano-based formulations of deltamethrin on H. hebetor should be considered in IPM programs.
Volume 0, Issue 0 (ARTICLES IN PRESS 2024)
Abstract
Poly- gamma- glutamic acid (γ-PGA) is a natural polymer with diverse applications across multiple industries. However, its use in agriculture is limited due to high production costs. This study aimed to optimize the cost-effective production of γ-PGA through Solid-State Fermentation (SSF) using Bacillus velezensis UTB96, evaluate the concentration and molecular weight of γ-PGA suitable for agricultural applications, particularly in strawberry cultivation, and explore the impact of γ-PGA on extending the shelf-life of strawberry fruits during cold storage. Initially, the production of γ-PGA using SSF with B. velezensis UTB96 was investigated, along with an evaluation of the influence of physicochemical factors on the molecular weight of γ-PGA. Based on the results, three different molecular weights of γ-PGA were identified: 1156.43 kDa, 734.38 kDa, and 296.55 kDa. These were selected for greenhouse trials to assess their effectiveness in controlling gray mold on strawberry plants. The results showed that by utilizing agricultural wastes, including sesame flour, wheat straw, and banana peel in SSF methodology, γ-PGA could be produced at a rate of 70 g/kg of dry weight of the culture medium. Analyzing the impact of γ-PGA on reducing gray mold revealed that this compound could enhance the plant's defense. A significant increase in the activity of ascorbate peroxidase and phenylalanine ammonia-lyase (PAL) enzymes was observed, along with the production of polyphenolic compounds such as ellagic acid. Consequently, these mechanisms improved the plant's flexibility and tolerance to the fungus, helping to maintain the quality of the fruits during cold storage.
Volume 0, Issue 0 (ARTICLES IN PRESS 2024)
Abstract
A total of 480 seven-day-old male Arian broiler chickens were divided into five treatment groups with six replicates each. The treatments were offered to the birds for three weeks (days 7 to 28) and included a control group, 10% raw hempseed (Cannabis sativa L) supplementation (RH), 10% RH with enzyme addition (RHE), 10% heat-treated hempseed (HH) in the diet, and 10% HH with enzyme supplementation (HHE). A completely randomized design with a 2 × 2 factorial arrangement (raw vs. heat-treated hempseed and with vs. without enzyme supplementation), plus a control group, was used. While dietary treatments (hemp supplementation) significantly increased body weight and feed intake, the heat processing decreased weight gain. Hemp supplementation significantly lowered Coliform and increased Lactobacillus content in the ileum, while processing increased Lactobacillus and enzyme addition decreased E Coli (P < 0.05). Digestibility parameters were positively affected by enzyme addition (P < 0.05) but protein digestibility was reduced by heating. There were no significant interaction effects (enzyme x supplementation and heat treatment) except for the Total Aerobes count of intestinal micro flora (P < 0.05). In conclusion, hempseed addition in the diet of broiler chickens during 7-28 days of age improved broiler performance and enzyme supplementation improved microbiology and more profoundly digestibility parameters.
Volume 0, Issue 0 (in press 2024)
Abstract
Concrete slabs subjected to near-field explosion loading often fail in a brittle manner. Common failure types include spalling and scabbing. Brittle failure leads to an inflexible and brittle structural response, producing small and large fragments that can be extremely dangerous due to their high velocities. Therefore, designing concrete slabs for explosive loading requires methods that either prevent or mitigate brittle failures or transform them into ductile failures. This study validates numerical models using LS-DYNA finite element software and compares them with reputable research. Simulations of concrete slabs were conducted using conventional methods, reinforced concrete slabs with steel plates, reinforced concrete slabs with wire mesh, and ultra-high-performance concrete (UHPC) slabs. The analysis of five slab types under similar explosion loading reveals that UHPC slabs exhibit less deflection and damage compared to other types, while conventional concrete slabs experience greater deflection and damage. The optimal reduction in damage for reinforced concrete slabs occurs when a steel plate measuring 2 by 4.2 meters and 0.5 centimeters thick is applied to the backside. Additionally, using wire mesh dimensions 25% larger than the initial slab damage yields the best performance. A comparative analysis of explosion-induced damage across different slab types indicates that reinforced concrete slabs with a 0.5-centimeter thick steel plate exhibit the largest damage area (8m2); whereas UHPC slabs show no damage, resulting in the smallest damage area. Further investigations into the dynamic response of these slabs demonstrate that advanced materials and reinforcement techniques significantly enhance their resilience against explosive forces. This study emphasizes the importance of innovative design strategies in civil engineering, highlighting that the adoption of UHPC slab minimizes structural damage and improves safety in high-risk environments. These findings underscore the necessity of incorporating modern materials and methodologies in protective structure design, ensuring better performance and longevity under extreme loading conditions. A comparative analysis of various methods for strengthening concrete slabs using identical materials shows that UHPC slabs outperform others in reducing deflection and failure. This illustrates their exceptional ability to withstand explosive dynamic loads. However, the primary limitation of UHPC slabs is their high cost and complexity of implementation. Reinforcement with steel sheets has proven more effective than wire mesh in minimizing deflection. In models reinforced with 0.5 cm steel sheets, deflection was reduced by 50% compared to conventional concrete slabs. The slabs reinforced with wire mesh demonstrated a significant decrease in failure rates compared to conventional slabs, with reductions ranging from 75% to 80% across various reinforcement methods using the same materials. Conversely, some models reinforced with steel sheets exhibited increased failure rates. The findings indicate that, in most cases, slabs with greater flexibility, such as those reinforced with wire mesh, sustained less damage. This can be attributed to the enhanced flexibility and ductility of wire mesh-reinforced slabs compared to those reinforced with steel sheets.
Concrete slabs subjected to near-field explosion loading often fail in a brittle manner. Common failure types include spalling and scabbing. Brittle failure leads to an inflexible and brittle structural response, producing small and large fragments that can be extremely dangerous due to their high velocities. Therefore, designing concrete slabs for explosive loading requires methods that either prevent or mitigate brittle failures or transform them into ductile failures. This study validates numerical models using LS-DYNA finite element software and compares them with reputable research. Simulations of concrete slabs were conducted using conventional methods, reinforced concrete slabs with steel plates, reinforced concrete slabs with wire mesh, and ultra-high-performance concrete (UHPC) slabs. The analysis of five slab types under similar explosion loading reveals that UHPC slabs exhibit less deflection and damage compared to other types, while conventional concrete slabs experience greater deflection and damage. The optimal reduction in damage for reinforced concrete slabs occurs when a steel plate measuring 2 by 4.2 meters and 0.5 centimeters thick is applied to the backside. Additionally, using wire mesh dimensions 25% larger than the initial slab damage yields the best performance. A comparative analysis of explosion-induced damage across different slab types indicates that reinforced concrete slabs with a 0.5-centimeter thick steel plate exhibit the largest damage area (8m2); whereas UHPC slabs show no damage, resulting in the smallest damage area. Further investigations into the dynamic response of these slabs demonstrate that advanced materials and reinforcement techniques significantly enhance their resilience against explosive forces. This study emphasizes the importance of innovative design strategies in civil engineering, highlighting that the adoption of UHPC slab minimizes structural damage and improves safety in high-risk environments. These findings underscore the necessity of incorporating modern materials and methodologies in protective structure design, ensuring better performance and longevity under extreme loading conditions. A comparative analysis of various methods for strengthening concrete slabs using identical materials shows that UHPC slabs outperform others in reducing deflection and failure. This illustrates their exceptional ability to withstand explosive dynamic loads. However, the primary limitation of UHPC slabs is their high cost and complexity of implementation. Reinforcement with steel sheets has proven more effective than wire mesh in minimizing deflection. In models reinforced with 0.5 cm steel sheets, deflection was reduced by 50% compared to conventional concrete slabs. The slabs reinforced with wire mesh demonstrated a significant decrease in failure rates compared to conventional slabs, with reductions ranging from 75% to 80% across various reinforcement methods using the same materials. Conversely, some models reinforced with steel sheets exhibited increased failure rates. The findings indicate that, in most cases, slabs with greater flexibility, such as those reinforced with wire mesh, sustained less damage. This can be attributed to the enhanced flexibility and ductility of wire mesh-reinforced slabs compared to those reinforced with steel sheets.
