Showing 16 results for Afkhami
Volume 0, Issue 0 (ARTICLES IN PRESS 2024)
Abstract
The issue of climate change and its associated water security challenges has become a growing concern for Iran, particularly in its agricultural sector. Increasing population, rising demand for agricultural products, and the need for food security exacerbate these challenges. This study highlights the risks posed by reduced precipitation, rising temperatures, and inefficient water management practices, including heavy reliance on groundwater and outdated irrigation systems. It emphasizes the urgent need for modern irrigation technologies, such as water recycling (NEWater), and robust governance reforms to improve water use efficiency, analyzed through the HES framework. The study concludes that adopting a comprehensive, long-term strategy, incorporating technological innovations, localized water management practices, and enhanced governance, can mitigate the impacts of climate change and ensure the sustainable use of water resources in Iran's agricultural sector.
Volume 5, Issue 14 (6-2017)
Abstract
SARAY" is part of the intangible heritage of the Azerbaijani people rooted in the culture, mentality and attitude of the people. So, it has been represented in oral literature, music, stories and poetry. In this study, the intangible cultural heritage is considered a cultural property, which pave the way to represent will, resistance and individual arguments of actual community activists to pass the crisis social and cultural contexts. The conceptual representation belongs to notion of Plato emerging in the idea and practice of recent intellectuals in the field of spiritual heritage which is now the main academic subject. This study was conducted qualitatively and has a descriptive and phenomenological research methodology. The purpose of this study is to investigate the permanent character of spiritual values or their representation in the urban life of the inhabitants of Ardebil by studying the spiritual heritage of Saray in the modern life of women in Ardabil. Intangible cultural heritage contains the historical, cultural, spiritual, scientific, and aesthetic values of current era, and can contribute to the growth and mobility of shared values and representations of values in everyday life. On the other hand, it refers to the existence of the culture of resistance and ethics of the region, and today it can be represented in the renewal of moral values, the commitment to the family for the present generations and future.
Volume 6, Issue 20 (6-2018)
Abstract
Most of the images on the ancient antiques and objects have their root in the folkloric and ancient beliefs, myths, anecdotes and faith of the nations. Thus by referring to the folkloric and anthropologic studies on the one hand and investigation and research on the oral literature and folk literature, local myths and legends on the other hand, we can explore the mysterious world of these images. Following the discovery of a gunmetal belt from the first millennium B.C. in Piranshahr; city located in southern part of Urmiah lake, related to the Mannai art and culture and investigating its images, some tracks of an ancient Kurdish folkloric story called “Beyeti goat and the lion” which is narrated in the traditional Kurdish circles has been found. It is possible that these images have historic roots of this folkloric story from the first and second millennium B.C. In this paper the author seeks to determine the relation between the images of this historic object and the story of “Beyeti goat and the lion” by adopting comparative approach and interdisciplinary studies.
Volume 8, Issue 3 (No. 8 (Tome 38), (Articles in Persian) 2017)
Abstract
This paper examines the interaction between the visual and the verbal modes, that is, the multimodality of transferring the meaning in Persian visual poetry in terms of cognitive base of different types of integrations which occur in the brain after different sensory channels transferring the visual and verbal data. Although contemporary poetry is multimodal, the visual poetry is considered a type of poetry that has both the verbal and the visual as the dominant, mixed modes that tend to construct the poetic meaning. Different arrangement of words and images, which has a neurological ground, requires different kinds of cognitive processing and will therefore induce different feelings, impressions, and connotations. Consequently, the general meaning of a multimodal text goes beyond that of the combination of the two modes.
Drawing on cognitive semiotics, this paper demonstrates how the multimodal poem is conceptualized through embodied experience. Furthermore, it shows how various types of visual/verbal synthetization in a poetry text are differed by a number of distinctive features. Moreover, it is shown how the meaning-making process and the resulting affection become possible in each type of visual poetry. Through modifying Aarhus’s model (2005, 2012), itself based on Fauconnier and Turner’s conceptual blending theory, this research puts forward twelve different types of interaction between the verbal and visual modes, which, in this paper, are mentioned just the three super basic classified categories due to the limitation of the journal’s space. In fact, the three super categories are:
It is about the general relations among the two or more modes or media. In this kind of relation, each mode/medium comprises separable and individually coherent texts in different mode/media to improve the meaning space at the end. It is divided into two sub-groups, which are Mode-adjacency and Multimodality.
It is a kind of transformations from one medium to another. An inter-medial text could be divided into Duplicating and Iconicity (Image iconicity, Relational diagram iconicity and Structural diagram iconicity). Duplicating could not presents an indissoluble connection of diverse modes as a fusion of different modal processes, while in the second one (Iconicity), the verbal and visual modes are fused together to represent the similarity or adjacency. The Duplicating could also be based on similarity or contiguity as well, that is the whole or a part of the text could be duplicated due to similarity of the verbal mode to visual mode or the contiguity of both together.
The third and the last type of relation between verbal and visual modes is mix-modal text, which is the combination of modes in a way that the complex signs in different modes would not be coherent or self-sufficient outside of that context. It is divided into four groups which are called in this research Counter-iconicity (Counter iconicity of mis-matching and Paradox-counter iconicity), Mode-situational inclusion, Mode-overlapping and complementary relation. Cognitively, these three basic types are processed respectively as following: bottom-up, top-down and integrated processing. Furthermore, these types are based on the structure of human brain and the functions of neurological cells, to study multimodal, especially visual poetry. Since both brain and literature contain similar patterns, it is inferred that each type of verbal-visual interaction that is constructed through a particular cognitive process will necessarily form specific emotions and impressions.
Volume 8, Issue 7 (No. 7 (Tome 42), Winter Special, (Articles in Persian) 2017)
Abstract
Critical metaphor analysis tries to be a multidisciplinary approach that studies the way social power abuse, dominance, and inequality are enacted, reproduced, and resisted by text and talk through metaphors in the social and political contexts.in the present research, through electing such approaches such as critical discourse analysis, cognitive linguistics, pragmatics and corpus analysis, instances of discourse metaphors extracted from opposing wing’s newspapers such as Keyhan and Mardomsalari in Iran and Telegraph and Mirror in England analyzed based on Lakoff’s cognitive approach and Cameron’s discourse metaphor following Charteris-black’s integrative critical metaphor research. The aim was to investigate the similarities and differences between metaphors and conceptual metaphors in each discourse and subsequently in each language. To tackle this concern, considering each wing’s core principals, political parts of the intended newspapers were analyzed and to narrow down the research just five source domains including conflict, structure, journey, religion and plants were focalized. The results showed that the aforementioned languages and the political wings are different in terms of source domains and frequency due to multilingual factors including society, history and culture. The results also demonstrated the metaphorical features of the discourses in terms of source domains. In this study also each kinds of Lakoff’s structural, ontological, directional metaphors and Cameron’s systematic metaphors were identified. Furthermore, this study showed how identical facts are demonstrated differently by opposing ideologies. Finally this eclectic approach came to known as an effective approach in demonstrating hidden power relations.
Volume 9, Issue 2 (No. 2 (Tome 44), (Articles in Persian) 2018)
Abstract
Animations, one of the virtues of digital world, subjectively demonstrates anthropomorphic representations of fantasy worlds in which human and non-human identities are constantly being revalued. In this milieu, animators are heirs to aesthetic resources functioning a mediating force to re-conceptualize and reorganize the world’s spatial coordinates. This paper probes the nature of creeping ideologies about consumerism, globalized world and denigrated non-American local cultures propagated in popular, animated Hollywood film Fantastic Mr. Fox through a multimodal analysis. Multimodality, an interdisciplinary approach to the study of contemporary communication and representation, justifiably claims that there are intricate processes of meaning-making achieved not only through language but also through a variety of modes, including image, gaze, gesture, movement, music, speech and sound–effect, that simultaneously and in various degrees contribute to the gestation of semiotic landscape. Applying a multimodal approach, we try to answer these questions: In what ways is multimodality a repertoire for scaffolding cultural identity? How can multimodal representations help immerse interpreters in the life-worlds of fictional characters? What is the best way to study processes of remediation as they bear on issues of multimodality? The significance of current study is emphasized by the formation of an increasingly intimate association between children, consumer culture, and lucre-oriented media in the USA, as well as the increasingly dire information emerging about disparaged local traditions. This analysis grossly represents the dual, alienating and often conflicting messages that commercial film provides for its young audiences about promised American utopia and their vociferously alleged panacea for the audiences’ desperate situation.
Volume 9, Issue 37 (3-2021)
Abstract
Wrestling has been popular since ancient times and it has been associated with many aspects of Iranian culture. In this regard, wrestling has been a physical ritual, and today it is performed at the national, indigenous, and local levels. This study focuses on the myths behind this ritual movement. It is aimed to explain the myths that have been the reason for the meaning, continuity, and the value of this movement as a ritual in Iranian folk culture throughout history via the analytical method. In ancient culture, a person who fought with the destructive forces of nature became the heroic archetype who created livelihood and security in a society and was respected by the people. This challenge with the antagonist also entered the arena of the enemies of Iran, and wrestling was a symbol of the action of the heroes who fought a duel to protect his land and its values; but what was suggested in Iranian culture was that these heroes, whose actions establish the security and order of the society, first, must clear their background as an antagonist, and voluntarily go into the battle with shadows. In Iranian society, this became a value and moral foundation for the heroic archetype and remained in the collective subconscious of the Iranian society, and in the festivals of folk culture where wrestling is held, all these values are projected on the wrestler character. This forms the kind of social identity and cohesion through which viewers receive love and self-fulfillment.
Introduction
Research background
A few research projects been done on wrestling in folk culture. However, in these studies, types of wrestling in folk culture have been studied on a case. In the culture of every city and village, a type of native and local wrestling is common, and most studies have focused on one of these types such as Chokheh wrestling or Gilehmardi wrestling. Qasem Mehrabi et al. (2014) have dealt with the interaction of spectators and wrestlers of Chokheh, and Rahmati and Abbaszadeh (2016) have paid attention to the ability of Gilehmardi wrestling in the development of social participation. Since wrestling has a long history in Iranian culture, it is necessary to conduct research on the values and social beliefs that have led to the continuation of this national, indigenous, and local sport.
Aims, questions, and assumptions
The aim of the present research is to describe the mythology that has caused the continuity, meaning, and value of wrestling in Iranian society throughout history. Therefore, three theories could be indicated in this regard: Jung's archetypal, Campbell's mono-myth, and Maslow's hierarchy of needs to describe these myths through a qualitative descriptive-analytical method. The main question of this study is: what myths are behind this ritual movement activity? Wrestling is probably a movement activity that was intertwined with rituals and represented many myths through ritual performances.
Discussion
Archaeological evidence with the motif of wrestling and Persian mythology in the cultural context of ancient Iranian society shows that wrestling is a physical activity in a ritual that represents the heroism of prehistoric times that killed monsters to provide security for human life (Campbell, 2005). The monster is a symbol of some destructive natural forces that destroys the security and livelihood of people. The protagonist's combat with natural destructive forces, such as wild animals, becomes a physical habitus in the Iranian culture and takes on a ritual aspect. This ritual physical activity combines with other aspects of Iranian culture so that it is a show for the legitimacy of the king as a provider of security for the people and the wrestling is performed in the celebration of nature revitalization in the spring (Kaptain, 2013). Thus, the wrestling is a symbol of the battle of two opposing forces, one good, and the other evil. It is the ideology of the culture of ancient Iran that the force of good always triumphs over evil by choosing the right manner for battle (Rezai Rad, 2010). Folk literature also tells the story of wrestlers who wrestle with fair behavior, avoiding any inappropriate behavior. Thus, the wrestler is a symbol of the heroic archetype who removes individual and collective needs and has moral principles. The moral foundation of the Iranian hero archetype is Mithraism, at the top of which is the struggle against the inner shadow. The religion of Mithraism is a form of mysticism that teaches its followers the moral and social principles to make the world a better place (Cumont, 1966). According to these teachings of mysticism, the wrestler is also the protector of the social values.
Conclusion
Wrestling is a physical activity that is intertwined with the dimensions of Iranian culture. Iranian myths and beliefs give meaning to this physical activity and its integration with other cultural aspects. The wrestling is not only reminiscent of the hero archetypal actions of the prehistoric time but with its functions, it satisfies the psychological needs of the wrestler and the people. Hence, people project the character and moral qualities of ancient heroes on the wrestler. The inner shadow is the most important opponent of the wrestling, and by overcoming it, he can show the right manner in his behavior through wrestling.
References
Rahmati, M. M., & Abbaszadeh, M. (2016). Capability of rural sport; local development & social participation: a case study of Gilehmardi wrestling.
Journal of Community Development,
7(1), 59-78.
Campbell, J. (2006).
The hero of a thousand faces (translated into Farsi Shadi Khosrow Panah). Mashhad: GolAftab.
Cumont, F. (1966).
The Mysteries of Mithra. Routledge.
Kaptan, D. (2014).
Achaemenid history XII. The Daskyleion Bullae: seal images from the western Achaemenid empire (translated into Farsi Morteza. Saghebfar). Tehran: Toos.
Rezaei Rad, M. (2011). Fundamentals of political thought in Mazdaean wisdom (in Farsi). Tehran: TarheNou.
Volume 11, Issue 2 (3-2020)
Abstract
In Archaeology the Iron Age refers to the period in which the immigration struggle intensified between different ethnic groups. The best data from these immigrant communities are their funerary structures. So that these structures have been seen in many areas of Archaeological where they are occupied. The most prominent funeral feature of these tribes that can be seen in the most entered lands is a circular stone structure on the grave that surrounds the central space or location of the dead. The study area is one of the flooded rivers of Meshgin city that such a system is one of the important factors in the appearance of the ancient sites of this part of Ardabil province. In archaeological surveys, many Iron Age cemeteries were identified and studied in this area. One of the sensible Features for the tombs of these cemeteries is interesting circle-shaped structures that surround the inside of the grave and location of the dead place. This research is worked with brief background of the transmittal rate of such structures in the second and first millennium B.C graves in different parts of the world with looking for the mythological and symbology studies that why and how the circular structures are made in the ancient Iron Age burials of Meshgin Chayi basin. A sociological regard to this topic shows that there have been special belief between Iron Age societies that believe on those due to appearance and continuation of special methods in the dead interment
Volume 12, Issue 2 (2-2021)
Abstract
Abstract
Upon the establishment of Zand government, social situation of Shiraz urban community which was affected by the ruling board entered a new phase. This social diversity led to some changes in the capital. One of the most important changes at this time was the formation of Kharabatian neighborhood and the activities of prostitutes therein. The neighborhood which started its activities following the social plans of the government left behind different changes in many aspects of the urban society of the capital. Therefore, the aim of the present study is to investigate the causes for the formation of this neighborhood and its social consequences in the urban society of Shiraz in the Zand era. The study followed a descriptive- analytical method and used the library data to investigate the research problem. The findings show that controlling and managing the political activists in Shiraz, managing the crisis-stricken society after the fall of Safavids, encouraging the activists to reconstruct and improve Shiraz along with the positive attitude of Karim Khan Zand to this group of females all were involved in the development of this neighborhood. Moreover, the whole kharabatian neighborhood provided a good income resource for the Zand government. One of the social consequences of creating this neighborhood is the disorder in the foundation of families. In addition, since this kind of social activity was in contrast with the social and religious beliefs of the people, it created some popular and legal abnormalities by some parts of the capital society.
Volume 12, Issue 4 (12-2023)
Abstract
Wheat seeds harbor different microbial populations, which can be associated with each other in neutral, positive, or negative interactions. The present study investigated the interaction of fluorescent Pseudomonas and Xanthomonas translucens (Xt) as an important wheat seed-borne pathogen. In addition to P. fluorescens (A7) and P. chloroaphis (A4), which were previously isolated from the rhizosphere of potato as potent biocontrol agents, six more non-pathogenic Pseudomonas strains that were isolated from wheat seeds, were studied. According to the general biochemical tests and partial 16S rRNA sequences alignment, the isolated strains were closely related to the species of P. gessardii, P. orientalis, P. poae, P. koreensis, and P. cedrina. The Pseudomonas strains exhibit different antagonistic activities, such as phosphate solubilization, cellulase, protease, and lipase production. Also, they have an apparent inhibition effect under in vivo conditions against X. translucens. Seed treatment by these strains led to suppressing bacterial leaf streak disease incidence in an early growth stage. However, disease progress enhanced with the seedling growth, resulting in the treated plants' complete death. Only in treated seeds by P. fluorescens (A7), P. chloroaphis(A4), and P. orientalis (Ais119) decrease of AUDPC up to 83%, 74%, and 63% was achieved, respectively, compared with the untreated controls. Our results showed that some fluorescent Pseudomonas strains could cause delay at the beginning of the disease appearance due to competition or producing antimicrobial metabolites during that time. In contrast, some may be considered a threat, enhancing disease development through synergistic effects.
Volume 13, Issue 2 (3-2022)
Abstract
Urban planning of Tehran until the period of Naser al-Din Shah continued in the style of urban planning of the Safavid period. This method only met the needs of a traditional city in various limited political, economic and social dimensions. From the time of Nasser al-Din Shah, Tehran as the capital of Iran in the Qajar period and in the face of the Western world became a platform for developments in the field of urban planning and a model for other cities in Iran in this field; However, these developments did not enter the city in its pure Western form and appeared in a mixed and influenced by the traditional Iranian society. Therefore, the aim of the present study is to investigate the impact of Western civilization and urban society of Tehran on the continuity and physical-spatial evolution of the city in the Naseri period. This research based on descriptive-analytical method has investigated this issue. The findings of this study show that the physical part of Tehran entered a new phase during the reign of Nasser al-Din Shah, influenced by Western civilization. These physical-spatial changes were not simply influenced by the modern Western world; Rather, indigenous cultural and artistic forces combined new influences with Iranian architecture. These developments were achieved on the one hand in the method of urban renewal in various dimensions and on the other hand in the quantitative dimension and the growth, reproduction and multiplicity of elements of the city.
Volume 15, Issue 5 (Supplementary Issue- 2015)
Abstract
In this research, MIKE SHE distributed hydrologic model and MIKE NAM lumped hydrologic model has been used for simulation of mean daily flow discharge in Gharasoo river basin in Ardebil province (Iran). Generally in the distributed models, the whole watershed is divided to small elements and the amount of each effective parameter on watershed for each element is considered separately. While in lumped models, watershed is considered as an integrative unit and effective parameters on watershed are considered with their intermediate quantity. Progressed and comprehensive hydrological models for more accurate calculation of flow discharge in watershed have been highly applied in recent years and progresses performed in the development of distributed and physically based models, oriented the research towards the evaluation and comparative studies with other models including lumped models.Because of the lack of the correct knowledge of complex hydrologic cycle in consequence of incorrect planning of water resources in watersheds, it is necessary to take an effective act for calculating flow discharge by using progressed and comprehensive models in direction of stable development of watersheds in our country. As mentioned above, the application of distributed and lumped models has been evaluated in simulation of mean daily flow discharge in Gharasoo river basin.The watershed area is about 4100 Km2 and its elevation ranges from 1200 to 4788 m above the mean sea level. the study area lies between 470 45' and 480 40'E longitude and 370 49' and 380 30' N latitude. The average annual precipitation of this study area is about 284 mm. The most part of the study area has been covered by grass lands and crop lands. For confidence of correct simulation of hydrological processes by both models, the simulated discharge has been compared with observed discharge related to Samiyan hydrometry station that situated in out of the watershed for calibration and validation periods by using of evaluation criteria. The evaluation criteria including Root Mean Squre Error (RMSE), Standard Deviation of the Residuals (STDres), Correlation Coefficient (r) and Nash Sutcliffe Correlation Efficiency(E) have been used for evaluation of the application of the modeles along calibration and validation periods.The MIKE SHE model simulated daily discharge well as corroborated by correlation coefficients of 0.85 and o.80, root mean square errors of 4.0571 and 1.598 m3/s, standard deviation of the residuals of 4.0523 and 1.6m3/s and nash sutcliffe correlation efficiencyof 0.71 and 0.63 respectively for calibration and validation periods. The MIKE NAM model simulated daily discharge well as corroborated by correlation coefficients of 0.87 and o.78, root mean square errors of 3.13 and 1.6651 m3/s, standard deviation of the residuals of 3.122 and 1.6650m3/s and nash sutcliffe correlation efficiencyof 0.83 and 0.60 respectively for calibration and validation periods. The results of comparision between two models show that both of the models have appropriate application in simulation of mean daily flow discharge in the watershed. Also according to the calculated coefficient of efficiency in validation period, MIKE SHE distributed model had more appropriate application than the MIKE NAM lumped model.
Volume 17, Issue 2 (7-2017)
Abstract
Abstract:
In most steel frame designs the beam to column connections are assumed to be rigid or pinned but in many steel frames we have beam to column connections with semi-rigid behavior. The structures with semi-rigid connections include systems with the connections in joints which are not completely rigid, but allow, usually, some relative movements in directions of generalized displacements.
Early experimental studies showed the importance of panel shear deformations for stable energy dissipation under cyclic loading. Modeling of the panel is very important for the avoidance of local failure of columns under ultimate limit state.
A substantial effort has been made in recent years to characterize the behavior of semi rigid connections. Recent studies and modern codes, in especially EC3 and EC4, include methods and formulas to resistance and stiffness of panel zone. EC3 proposes a mechanical model for the semi-rigid joint in which each component is modeled by an equivalent linear spring.In these model we have some components that show with springs. These springs are assembled to form a single bilinear (elastic–plastic) rotational spring that models the connection, and is attached at the intersection between beam and column for the global analysis.
Both the stiffness and strength of the springs in EC3 and EC4 depend on β factor that definition of this parameter implies an approximation of the internal forces at the joint, and therefore its use requires an iterative process at the time of performing the global analysis of the structure. So E.Bayo proposed a new component-based method (or cruciform element method) to model internal and external semi-rigid connections that revived and modified EC methods. So a cruciform element (a four-node element) is proposed to avoid β factor, and the inherent initial guessing and iterative process that it requires, and includes the finite size and deformation modes of the joint.
One of main problems that structural engineer deal with is considering End Length Offset in conventional softwares. Extended end plate connection is one of beam-column semi rigid connection that we want to evaluate this behavios by using cruciform connection model and other panel zone models.
In this paper three 2 dimensional frames with extended end plate connections are modeld in MATLAB using Cruciform element method and these result are compared with SAP2000 results in eight cases that in four cases panel zone are modeld and four cases are without panel zone modeling. In which of this End Length Offset considering are once just for beams and the other for beams and columns (in two case of Rigid Zone Factor : 0.5 and 1). The results show that modeling panel zones according to EC method and considering Rigid Zone Factor equal to 1 in columns and beams are best assumption to analysis of 2D frames with extend end plate connections, but if we don’t model panel zones, we must considering Rigid Zone Factor equal to 0.5 in columns and beams to give nearby actual results.
Keywords: semi rigid connections, extended end plate, Rigid Zone Factor, End Length Offset
Volume 18, Issue 113 (july 2021)
Abstract
Application of extracts and essential oils with antioxidative properties to stabilize edible oils is a usual approach. However, this needs extraction of essential oils and extracts which is time consuming and costly. A new method is using herbs with oilseeds during the oil extraction by press. In this study, rosemary leaf at 0 (control sample), 2.5, 5, 7.5 and 10% (w/w) was added to black cumin seeds (BS) and oil then extracted by screw press. Extracted oil qualitative properties were determined in production day and every 30 days during 90 days of storage. Obtained results showed that level of essential oil increased (from 0.1 to 0.77%) by increasing the level of RL. Peroxide value of the extracted oils was decreased from 20 to 8.8 (meqO2/Kg oil) by increasing the RL with higher oxidative stability during storage. Acidity was increased in the oil samples extracted from the BS with RL higher than 5%. Chlorophyll and carotenoids contents were increased from 52 to 204 (mg/kg oil) and 5.2 to 13.7 mg/kg oil, respectively, but their content decreased due to decomposition about by half during storage. In conclusion, obtained results showed that new method of pressing BS incorporated with RL an herb with antioxidative properties is possible and could give a new product and an oil with higher oxidative stability.
Volume 19, Issue 6 (12-2019)
Abstract
Concrete is a useful material in today industry that must be known behavior against environmental phenomenon including fire concurrent using this material in various industries. Generally, in concrete two phases being visible, the solid phase includes cement paste with other aggregates and additives, and liquid phase includes water placing in concrete pores. When applying the fire in the concrete segments, in addition to some reactions occur in the solid phase, some changes are seen in the liquid phase and gradually gas phase including vapor in the concrete pores will be built. Usually, evaporation starts in concrete pores water at the 100 °C temperature and since concrete temperature passes 150 °C all of the water in pores changes to vapor and flows in the colder side of concrete and accumulate at this portion. When 100 °C front temperature further progresses in the concrete, evaporation speed increases and flows in the colder side and accumulation zone of water grows until this zone becomes full of vapor and creates a saturated layer in pores that prevents from fluid flowing. After this layer saturated by vapor invasion from the hot side, pore pressure gradually develops and with this event tension stresses at this side of concrete will increase. With continue increasing fire intensity, saturated layer creation speed increases and pore pressure and tension stress increment occur. In the following of this process, if tension stress is becoming bigger than tensile strength, fracturing and loss of material from this layer are caused, i.e. spalling occurs. This paper present an analytical modeling using ABAQUS software to evaluating concrete fire behavior. Modeling and analysis of concrete slab under fire in this study includes some steps. In the first step, heat transfer modeling and analysis of solid part is done. In the following "soils" analysis based on initial heat transfer analysis result is accomplished, that vapor flowing between pores, the saturated layer forming and pore pressure developing occur in this step. Concurrent soils analysis, using USDFLD and UMESHMOTION subroutines that joined to software, pore pressure, and tension stress value are controlled and if spalling occurs in the concrete slab, spalled layer depth and time of spalling are determined and saved. One of the most important issues facing in the fire at structures is elevated temperature patterns subject and especially fire curves types. Because of the importance of this issue, some of these fire curves placed in the famous codes. One of the most popular fire curves in the structure is the ISO834 fire curve that based on cellulose fire. Although many researchers use the ISO834 fire curve in their research, when a fire occurs in structure with petroleum and hydrocarbons products, elevated temperature speed is higher than ISO834. So the fire curve based on low petroleum product in the structure presented, is named hydrocarbon (HC) curve. Results show that applying Hydrocarbon fire in concrete increase pore pressure more than double and accelerate spalling process in comparison to ISO834 fire and by modifying permeability of concrete from 5x10-17m2 to 5x10-16m2, pore pressure decrease less than one tenth even prevent spalling phenomenon.
Volume 20, Issue 145 (March 2024)
Abstract
Vegetable oils play an important role in food preparation and food formulation and play a significant role in diet and health. Identification and cultivation of new oilseeds is an important step in the direction of supplying the required oil in the country. Milk thistle plant with the scientific name of Silybum marianum is a one-year or two-year herb that has many medical, medicinal and industrial uses since ancient times. Due to its biological characteristics, this plant requires very little fertilizer and is particularly resistant to dry conditions and weak soils, and it is compatible with the climate conditions of most regions of Iran. Milk thistle seed contains a significant percentage of oil (20-30%) with high nutritional value due to the presence of essential fatty acids such as linoleic acid (40-60%), oleic acid (20-32%) and antioxidant and bioactive compounds such as tocopherols, carotenoids and sterols. Therefore, the oil obtained from milk thistle seed can be considered as a new edible oil due to its long-term consumption in different societies and its bioactive compounds. In this review article, a brief look at milk thistle plant, oil percentage and its composition in different regions has been discussed. According to scientific reports and articles, the cultivation and development of this new and valuable oil seed with good economic value is recommended as a new source of edible oil.