Search results for: experimental linguistics

Authors: Jayashree And Gajjam

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Intellectual humility (IH) is defined as a virtuous mean between intellectual arrogance and intellectual self-diffidence by the ‘Doxastic Account of IH’ studied, researched and developed by western scholars not earlier than 2015 at the University of Edinburgh. Ancient Indian philosophical texts or the Upanisads written in the Sanskrit language during the later Vedic period (circa 600-300 BCE) have long addressed the virtue of being humble in several stories and narratives. The current research paper questions and revisits these character traits in an Indian context following an experimental method. Based on the subjective reports of more than 400 Indian teenagers and adults, it argues that while a few traits of IH (such as trustworthiness, respectfulness, intelligence, politeness, etc.) are panhuman and pancultural, a few are not. Some attributes of IH (such as proper pride, open-mindedness, awareness of own strength, etc.) may be taken for arrogance by the Indian population, while other qualities of Intellectual Diffidence such as agreeableness, surrendering can be regarded as the characteristic of IH. The paper then gives the reasoning for this discrepancy that can be traced back to the ancient Indian (Upaniṣadic) teachings that are still prevalent in many Indian families and still anchor their views on IH. The name Upanisad itself means ‘sitting down near’ (to the Guru to gain the Supreme knowledge of the Self and the Universe and setting to rest ignorance) which is equivalent to the three traits among the BIG SEVEN characterized as IH by the western scholars viz. ‘being a good listener’, ‘curious to learn’, and ‘respect to other’s opinion’. The story of Satyakama Jabala (Chandogya Upanisad 4.4-8) who seeks the truth for several years even from the bull, the fire, the swan and waterfowl, suggests nothing but the ‘need for cognition’ or ‘desire for knowledge’. Nachiketa (Katha Upanisad), a boy with a pure mind and heart, follows his father’s words and offers himself to Yama (the God of Death) where after waiting for Yama for three days and nights, he seeks the knowledge of the mysteries of life and death. Although the main aim of these Upaniṣadic stories is to give the knowledge of life and death, the Supreme reality which can be identical with traits such as ‘curious to learn’, one cannot deny that they have a lot more to offer than mere information about true knowledge e.g., ‘politeness’, ‘good listener’, ‘awareness of own limitations’, etc. The possible future scope of this research includes (1) finding other socio-cultural factors that affect the ideas on IH such as age, gender, caste, type of education, highest qualification, place of residence and source of income, etc. which may be predominant in current Indian society despite our great teachings of the Upaniṣads, and (2) to devise different measures to impart IH in Indian children, teenagers, and younger adults for the harmonious future. The current experimental research can be considered as the first step towards these goals.

Keywords: ethics and virtue epistemology, Indian philosophy, intellectual humility, upaniṣadic texts in ancient India

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Authors: Yi-An Liao, Lu-Wei Kuo, Yu-Jen Shih, Yao-Hui Huang

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Abstract—Imidacloprid (IMI, a widely used pesticide, iImidacloprid (IMI), a widely used pesticide, is known to affect the bee populations. A sulfate radical-based oxidation method was utilized to remove the commercial pesticide consisted of IMI, dimethylacetamide, N-methyl-2-pyrrolidone, and methanol (TOC0 = 497 ppm). The experimental results evidenced that sulfate radicals created by UV activation (254nm, 6.4 mW/cm2) of S2O82- could remove 97% of total organic carbon (TOC) from the synthetic wastewater in 4 h using 120 mM of oxidant dosage. The dose of oxidant, temperature and the light flux were the key factors to further improve the mineralization efficiency, while the ferrous ions decreased the efficacy of UV/S2O82- reaction due to the competition of UV-adsorption by complex formation of FeSO4+.s known to affect the bee populations. A sulfate radical-based oxidation method was utilized to remove the commercial pesticide consisted of IMI, dimethylacetamide, N-methyl-2-pyrrolidone, and methanol (TOC0 = 497 ppm). The experimental results evidenced that sulfate radicals created by UV activation (254nm, 6.4 mW/cm2) of S2O82- could remove 97% of total organic carbon (TOC) from the synthetic wastewater in 4 h using 120 mM of oxidant dosage. The dose of oxidant, temperature and the light flux were the key factors to further improve the mineralization efficiency, while the ferrous ions decreased the efficacy of UV/S2O82- reaction due to the competition of UV-adsorption by complex formation of FeSO4+.

Keywords: organic nitrogen, photochemical oxidation, imidacloprid, UV-persulfate, mineralization

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Authors: Hao Yang, Lei Chen, Ting Mei, Jianbang Zheng

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Currently, the uncooled PbSe photodetectors in the mid-infrared range (2-5μm) with sensitization technology extract more photoelectric response than traditional ones, and enable the room temperature (300K) photo-detection with high detectivity, which have attracted wide attentions in many fields. This technology generally contains the film fabrication with vapor phase deposition (VPD) and a sensitizing process with doping of oxygen and iodine. Many works presented in the recent years almost provide and high temperature activation method with oxygen/iodine vapor diffusion, which reveals that oxygen or iodine plays an important role in the sensitization of PbSe material. In this paper, we provide our latest experimental results and discussions in the stoichiometry of oxygen and iodine and its influence on the polycrystalline structure and photo-response. The experimental results revealed that crystal orientation was transformed from (200) to (420) by sensitization, and the responsivity of 5.42 A/W was gained by the optimal stoichiometry of oxygen and iodine with molecular density of I2 of ~1.51×1012 mm-3 and oxygen pressure of ~1Mpa. We verified that I2 plays a role in transporting oxygen into the lattice of crystal, which is actually not its major role. It is revealed that samples sensitized with iodine transform atomic proportion of Pb from 34.5% to 25.0% compared with samples without iodine from XPS data, which result in the proportion of about 1:1 between Pb and Se atoms by sublimation of PbI2 during sensitization process, and Pb/Se atomic proportion is controlled by I/O atomic proportion in the polycrystalline grains, which is very an important factor for improving responsivity of uncooled PbSe photodetector. Moreover, a novel sensitization and dopant activation method is proposed using oxygen ion implantation with low ion energy of < 500eV and beam current of ~120μA/cm2. These results may be helpful to understanding the sensitization mechanism of polycrystalline lead salt materials.

Keywords: polycrystalline PbSe, sensitization, transport, stoichiometry

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Authors: Mir Jalil Razavi, Tianming Liu, Xianqiao Wang

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Cortical folding, characterized by convex gyri and concave sulci, has an intrinsic relationship to the brain’s functional organization. Understanding the mechanism of the brain’s convoluted patterns can provide useful clues into normal and pathological brain function. During the development, the cerebral cortex experiences a noticeable expansion in volume and surface area accompanied by tremendous tissue folding which may be attributed to many possible factors. Despite decades of endeavors, the fundamental mechanism and key regulators of this crucial process remain incompletely understood. Therefore, to taking even a small role in unraveling of brain folding mystery, we present a mechanical model to find mechanism of 3-hinges formation in a growing brain that it has not been addressed before. A 3-hinge is defined as a gyral region where three gyral crests (hinge-lines) join. The reasons that how and why brain prefers to develop 3-hinges have not been answered very well. Therefore, we offer a theoretical and computational explanation to mechanism of 3-hinges formation in a growing brain and validate it by experimental observations. In theoretical approach, the dynamic behavior of brain tissue is examined and described with the aid of a large strain and nonlinear constitutive model. Derived constitute model is used in the computational model to define material behavior. Since the theoretical approach cannot predict the evolution of cortical complex convolution after instability, non-linear finite element models are employed to study the 3-hinges formation and secondary morphological folds of the developing brain. Three-dimensional (3D) finite element analyses on a multi-layer soft tissue model which mimics a small piece of the brain are performed to investigate the fundamental mechanism of consistent hinge formation in the cortical folding. Results show that after certain amount growth of cortex, mechanical model starts to be unstable and then by formation of creases enters to a new configuration with lower strain energy. By further growth of the model, formed shallow creases start to form convoluted patterns and then develop 3-hinge patterns. Simulation results related to 3-hinges in models show good agreement with experimental observations from macaque, chimpanzee and human brain images. These results have great potential to reveal fundamental principles of brain architecture and to produce a unified theoretical framework that convincingly explains the intrinsic relationship between cortical folding and 3-hinges formation. This achieved fundamental understanding of the intrinsic relationship between cortical folding and 3-hinges formation would potentially shed new insights into the diagnosis of many brain disorders such as schizophrenia, autism, lissencephaly and polymicrogyria.

Keywords: brain, cortical folding, finite element, three hinge

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Authors: Safa Kaka

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As more and more students are travelling to different countries to study and, in particular, to study English, the question of what motivates them to make such a large move has come under question. This is particularly pertinent in the case of Arab students who make up nearly 15% of the foreign student body in the UK. Given that the cultural differences between the UK and Arab nations are extremely wide, the decision to come to this country to study English must be driven by strong motivational forces. Numerous previous studies have considered what motivates foreign students to travel to the UK and other countries for their education or language learning but the specific motivators of Arab students have yet to be explored. This study undertakes to close that gap by examining the concepts and theories of motivation, both in general terms and in relation to English learning and foreign study. 70 Arab students currently studying in the UK were asked to participate in an online questionnaire which asked about their motivations for coming to the UK and for studying and learning English. A further six individuals were interviewed on a face to face basis. The outcomes have indicated that the factors which motivate the decision to come to the UK are similar to those that motivate the desire to learn English. In particular a motivation for self-improvement, career advancement and potential future benefits were cited by a number of respondents. Other indications were the ease of accessibility to the UK as an English speaking country, a motivation to experience different cultures and lifestyles and even political freedoms. Overall the motivations of Arab students were not found to be conspicuously different from those of other foreign students, although it was noted that their motivations did change, both positively and negatively following a period of time in the country. These changes were based on the expectations of the students pre-arrival and their actual experience of the country and its teaching approaches and establishments and were, as indicated both good and bad. The implications for the Arab student population and UK educational establishments are reviewed and future research pathways highlighted.

Keywords: motivation, Arab learners of English, language teaching, applied linguistics

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Authors: Mahnaz Zarein, Hamed Shoorei

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Background: Malathion is one of the most toxic agents widely used in agriculture throughout the world. This agent has adverse effects on the functions of multiple organs such as the reproductive system in both male and female genders. On the one hand, daily use of antioxidant supplementations such as hesperidin is capable to neutralize the deleterious impacts of malathion. Therefore, in this experimental study, the protective effects of hesperidin against ovarian toxicity induced by malathion were investigated. Material & Methods: Balb/c adult mice (n=32) were randomly divided into 4 groups including 1) the control group, treated with normal saline, 2) the Mal group, treated with 30mg/kg malathion, daily for 1 month, 3) Mal + Hes group, treated with 20 mg/kg malathion and 20 mg/kg hesperidin, daily for 1 month, and 5) Hes group, treated with 20 mg/kg hesperidin. At the end of the experimental period, mice were anesthetized and their drops of blood were collected to the assessment of some hormones such as LH, FSH, E2, and P4. Also, the right ovaries were used to H&E staining, and the left ovaries were used for IHC staining (PCNA and FSHR). Results: Histopathological assessments showed that the number of follicles, i.e. primordial, primary, and secondary, significantly decreased, while the atretic follicle counts remarkably increased compared to the control group (p<0.05). Hormonal levels revealed that the production of all mentioned hormones decreased in the Mal group in comparison with the control group (p<0.05). The expression of PCNA, as a proliferative marker, and FHSR, as a marker showing maturation, decreased when mice received malathion compared to the control group (p<0.05). Interestingly, treatment with hesperidin significantly neutralized the adverse effects of malathion on all mentioned parameters. Conclusion: Daily use of antioxidant supplementations such as hesperidin could alleviate the ovarian toxicity induced by malathion.

Keywords: malathion, ovary, antioxidant hesperidin, FSHR PCNA, ovary

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Authors: Malek Miladi, Miguel Vegara, Maria Perez-Infantes, Khaled Mohamed Ramadan, Antonio Ruiz-Canales, Damaris Nunez-Gomez

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Coffee is the second consumed commodity worldwide, yet it also generates colossal waste. Proper management of coffee waste is proposed by converting them into products with higher added value to achieve sustainability of the economic and ecological footprint and protect the environment. Based on this, a study looking at the recovery of coffee waste is becoming more relevant in recent decades. Spent coffee grounds (SCG's) resulted from brewing coffee represents the major waste produced among all coffee industry. The fact that SCGs has no economic value be abundant in nature and industry, do not compete with agriculture and especially its high oil content (between 7-15% from its total dry matter weight depending on the coffee varieties, Arabica or Robusta), encourages its use as a sustainable feedstock for bio-oil production. The bio-oil extraction is a crucial step towards biodiesel production by the transesterification process. However, conventional methods used for oil extraction are not recommended due to their high consumption of energy, time, and generation of toxic volatile organic solvents. Thus, finding a sustainable, economical, and efficient extraction technique is crucial to scale up the process and to ensure more environment-friendly production. Under this perspective, the aim of this work was the statistical study to know an efficient strategy for oil extraction by n-hexane using indirect sonication. The coffee waste mixed Arabica and Robusta, which was used in this work. The temperature effect, sonication time, and solvent-to-solid ratio on the oil yield were statistically investigated as dependent variables by Central Composite Rotatable Design (CCRD) 23. The results were analyzed using STATISTICA 7 StatSoft software. The CCRD showed the significance of all the variables tested (P < 0.05) on the process output. The validation of the model by analysis of variance (ANOVA) showed good adjustment for the results obtained for a 95% confidence interval, and also, the predicted values graph vs. experimental values confirmed the satisfactory correlation between the model results. Besides, the identification of the optimum experimental conditions was based on the study of the surface response graphs (2-D and 3-D) and the critical statistical values. Based on the CCDR results, 29 ºC, 56.6 min, and solvent-to-solid ratio 16 were the better experimental conditions defined statistically for coffee waste oil extraction using n-hexane as solvent. In these conditions, the oil yield was >9% in all cases. The results confirmed the efficiency of using an ultrasound bath in extracting oil as a more economical, green, and efficient way when compared to the Soxhlet method.

Keywords: coffee waste, optimization, oil yield, statistical planning

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Authors: Tahani Aljohani, Jialin Yu, Alexandra. I. Cristea

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The more an educational system knows about a learner, the more personalised interaction it can provide, which leads to better learning. However, asking a learner directly is potentially disruptive, and often ignored by learners. Especially in the booming realm of MOOC Massive Online Learning platforms, only a very low percentage of users disclose demographic information about themselves. Thus, in this paper, we aim to predict learners’ demographic characteristics, by proposing an approach using linguistically motivated Deep Learning Architectures for Learner Profiling, particularly targeting gender prediction on a FutureLearn MOOC platform. Additionally, we tackle here the difficult problem of predicting the gender of learners based on their comments only – which are often available across MOOCs. The most common current approaches to text classification use the Long Short-Term Memory (LSTM) model, considering sentences as sequences. However, human language also has structures. In this research, rather than considering sentences as plain sequences, we hypothesise that higher semantic - and syntactic level sentence processing based on linguistics will render a richer representation. We thus evaluate, the traditional LSTM versus other bleeding edge models, which take into account syntactic structure, such as tree-structured LSTM, Stack-augmented Parser-Interpreter Neural Network (SPINN) and the Structure-Aware Tag Augmented model (SATA). Additionally, we explore using different word-level encoding functions. We have implemented these methods on Our MOOC dataset, which is the most performant one comparing with a public dataset on sentiment analysis that is further used as a cross-examining for the models' results.

Keywords: deep learning, data mining, gender predication, MOOCs

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Authors: Linnan Zhang

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Linguists, as well as psychologists, have shown great interests in implicit causality in reference processing. However, most frequently-used approaches to this issue are psychological experiments (such as eye tracking or self-paced reading, etc.). This research is a corpus-based one and is assisted with statistical tool – software R. The main focus of the present study is about the competition between verb-based implicit causality and theme structure’s influence on anaphora bias in Mandarin Chinese sentences. In Accessibility Theory, it is believed that salience, which is also known as accessibility, and relevance are two important factors in reference processing. Theme structure, which is a special syntactic structure in Chinese, determines the salience of an antecedent on the syntactic level while verb-based implicit causality is a key factor to the relevance between antecedent and anaphora. Therefore, it is a study about anaphora, combining psychology with linguistics. With analysis of the sentences from corpus as well as the statistical analysis of Multinomial Logistic Regression, major findings of the present study are as follows: 1. When the sentence is stated in a ‘cause-effect’ structure, the theme structure will always be the antecedent no matter forward biased verbs or backward biased verbs co-occur; in non-theme structure, the anaphora bias will tend to be the opposite of the verb bias; 2. When the sentence is stated in a ‘effect-cause’ structure, theme structure will not always be the antecedent and the influence of verb-based implicit causality will outweigh that of theme structure; moreover, the anaphora bias will be the same with the bias of verbs. All the results indicate that implicit causality functions conditionally and the noun in theme structure will not be the high-salience antecedent under any circumstances.

Keywords: accessibility theory, anaphora, theme strcture, verb-based implicit causality

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Authors: Jibril Mohammed, Usman Dadum Hamza, Muhammad Idris Misau, Baba Yahya Danjuma, Yusuf Bode Raji, Abdulsalam Surajudeen

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Volatile organic compounds (VOCs) have been reported to be responsible for many acute and chronic health effects and environmental degradations such as global warming. In this study, a renewable and low-cost coconut shell activated carbon (PHAC) was synthesized and treated with ammonia (PHAC-AM) to improve its hydrophobicity and affinity towards VOCs. Removal efficiencies and adsorption capacities of the ammonia treated activated carbon (PHAC-AM) for benzene and toluene were carried out through batch and fixed-bed studies respectively. Langmuir, Freundlich and Tempkin adsorption isotherms were tested for the adsorption process and the experimental data were best fitted by Langmuir model and least fitted by Tempkin model; the favourability and suitability of fitness were validated by equilibrium parameter (RL) and the root square mean deviation (RSMD). Judging by the deviation of the predicted values from the experimental values, pseudo-second-order kinetic model best described the adsorption kinetics than the pseudo-first-order kinetic model for the two VOCs on PHAC and PHAC-AM. In the fixed-bed study, the effect of initial VOC concentration, bed height and flow rate on benzene and toluene adsorption were studied. The highest bed capacities of 77.30 and 69.40 mg/g were recorded for benzene and toluene respectively; at 250 mg/l initial VOC concentration, 2.5 cm bed height and 4.5 ml/min flow rate. The results of this study revealed that ammonia treated activate carbon (PHAC-AM) is a sustainable adsorbent for treatment of VOCs in polluted waters.

Keywords: volatile organic compounds, equilibrium and kinetics studies, batch and fixed bed study, bio-based activated carbon

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Authors: Maciej Buczowski

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This study investigates the impact of non-verbal communication training on enhancing the emotional intelligence (EI) of participants in higher education exchange programs. Recognizing the vital role EI plays in academic and professional success, particularly in multicultural environments, this research aims to explore the interplay between non-verbal cues and EI. Utilizing a longitudinal mixed-methods approach, the study will assess EI development over time among international students and faculty members. Participants will undergo a comprehensive non-verbal communication training program, covering modules on recognizing and interpreting emotional expressions, understanding cultural variations, and using non-verbal cues to manage interpersonal dynamics. EI levels will be measured using established instruments such as the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) and the Emotional Quotient Inventory (EQ-i), supplemented by qualitative data from interviews and focus groups. A control group will be included to validate the intervention's effectiveness. Data collection at multiple time points (pre-training, mid-training, post-training, and follow-up) will enable tracking of EI changes. The study hypothesizes significant improvements in participants' EI, particularly in emotional awareness, empathy, and relationship management, leading to better academic performance and increased satisfaction with the exchange experience. This research aims to provide insights into the relationship between non-verbal communication and EI, potentially influencing the design of exchange programs to include EI development components and enhancing the effectiveness of international education initiatives.

Keywords: emotional intelligence, higher education exchange program, non-verbal communication, intercultural communication, cognitive linguistics

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Authors: Lenore Van Den Berg

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Vocabulary development is positively associated with reading development, reading comprehension, and academic achievement. It is frequently stated that South Africa is in the midst of a literacy crisis. The past 24 years since the first democratically elected government have not revolutionised the education system; rather, after various curriculum changes and continued struggles to incorporate all 11 official languages as languages of instruction, research shows that 78 per cent of South African Grade 4 learners are functionally illiterate. The study sets out to find solutions to this problem and to add to the research base on vocabulary acquisition by assessing the effect of integrating the principles of explicit, interactive vocabulary instruction, within the context of storybook reading, on Grade 1 vocabulary acquisition. Participants comprised of 69 Grade 1 English second language learners from three classes in two government primary schools. The two schools differ in socio-economic status (SES), with School A having a lower SES than School B. One Grade 1 class was randomly assigned to be the Experimental Group, while two other classes served as control groups. The intervention took place for a period of 18 weeks and consisted of 30-minute storybook reading sessions, accompanied by interactive vocabulary instruction, twice a week. The Peabody Picture Vocabulary Test IV (PPVT-IV) was the diagnostic test administered to all learners before the intervention, as a pre-test, and after the interventions as a post-test. Data regarding excising vocabulary instruction practices and approaches were also collected through classroom observations and individual, semi-structured interviews with the Experimental Group’s teacher. Findings suggest that second language storybook reading, accompanied by explicit, interactive vocabulary instruction, have a positive impact on Grade 1 vocabulary acquisition but that vocabulary teaching practices and socio-economic status also play a key role in vocabulary acquisition.

Keywords: interactive vocabulary instruction, second language vocabulary, storybook reading, vocabulary acquisition, reading development, PPVT

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Authors: Mohammad Jahangeer Warsi

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This is, perhaps, the first linguistic study of Maithili Urdu, a dialect of Urdu language of Indo-Aryan family, spoken by around four million speakers in Darbhanga, Samastipur, Begusarai, Madhubani, and Muzafarpur districts of Bihar. It has the subject–verb–object (SOV) word order and it lacks script and literature. Needless to say, this work is an attempt to document this dialect so that it should contribute to the field of descriptive linguistics. Besides, it is also spoken by majority of Maithili diaspora community. Maithili Urdu does not have its own script or literature, yet it has maintained an oral history of over many centuries. It has contributed to enriching the Maithili, Hindi and Urdu languages and literature very profoundly. Dialects are the contact languages of particular regions, and they have a deep impact on their cultural heritage. Slowly with time, these dialects begin to take shape of languages. The convergence of a dialect into a language is a symbol and pride of the people who speak it. Although, confined to the five districts of northern Bihar, yet highly popular among the natives, it is the primary mode of communication of the local Muslims. The paper will focus on the structure of expressions about Maithili Urdu that include the structure of words, phrases, clauses, and sentences. There are clear differences in linguistic features of Maithili Urdu vis-à-vis Urdu, Maithili and Hindi. Though being a dialect of Urdu, interestingly, there is only one second person pronoun tu and lack of agentive marker –ne. Although being spoken in the vicinity of Hindi, Urdu and Maithili, it undoubtedly has its own linguistic features, of them, verb conjugation is remarkably unique. Because of the oral tradition of this link language, intonation has become significantly prominent. This paper will discuss the morpho-syntactic pattern of Maithili Urdu and will go through a sample text to authenticate the findings.

Keywords: cultural heritage, morpho-syntactic pattern, Maithili Urdu, verb conjugation

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Authors: Marina Fomina

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The paper focuses on the category of semantic subject within the framework of a functional approach to linguistics. The semantic subject is related to similar notions such as the grammatical subject and the bearer of predicative feature. It is the multifaceted nature of the category of subject that 1) triggers a number of issues that, syntax-wise, remain to be dealt with (cf. semantic vs. syntactic functions / sentence parts vs. parts of speech issues, etc.); 2) results in a variety of approaches to the category of subject, such as formal grammatical, semantic/syntactic (functional), communicative approaches, etc. Many linguists consider the prototypical approach to the category of subject to be the most instrumental as it reveals the integrity of denotative and linguistic components of the conceptual category. This approach relates to subject as a source of non-passive predicative feature, an element of subject-predicate-object situation that can take on a variety of semantic roles, cf.: 1) an agent (He carefully surveyed the valley stretching before him), 2) an experiencer (I feel very bitter about this), 3) a recipient (I received this book as a gift), 4) a causee (The plane broke into three pieces), 5) a patient (This stove cleans easily), etc. It is believed that the variety of roles stems from the radial (prototypical) structure of the category with some members more central than others. Translation-wise, the most “treacherous” subject types are the peripheral ones. The paper 1) features a peripheral status of spatial impersonal sentence models such as U menia v ukhe zvenit (lit. I-Gen. in ear buzzes) within the category of semantic subject, 2) makes a structural and semantic analysis of the models, 3) focuses on their Russian-English translation patterns, 4) reveals non-prototypical features of subjects in the English equivalents.

Keywords: bearer of predicative feature, grammatical subject, impersonal sentence model, semantic subject

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Authors: Thomas Soro, Tim Stott, Brendan O'Rourke

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The construction of artistic reputation has been examined within sociology, philosophy, and economics but, baring a few noteworthy exceptions its discursive aspect has been largely ignored. This is particularly surprising given that contemporary artworks primarily rely on discourse to construct their ontological status. This paper contributes a discourse analytical perspective to the broad body of literature on artistic reputation by providing an understanding of how it is discursively constructed within the institutional context of online contemporary art magazines. This paper uses corpora compiled from the websites of e-flux and ARTnews, two leading online contemporary art magazines, to examine how these organisations discursively construct the reputation of artists. By constructing word-sketches of the term 'Artist', the paper identified the most significant modifiers attributed to artists and the most significant verbs which have 'artist' as an object or subject. The most significant results were analysed through concordances and demonstrated a somewhat surprising lack of evaluative representation. To examine this feature more closely, the paper then analysed three announcement texts from e-flux’s site and three review texts from ARTnews' site, comparing the use of modifiers and verbs in the representation of artists, artworks, and institutions. The results of this analysis support the corpus findings, suggesting that artists are rarely represented in evaluative terms. Based on the relatively high frequency of evaluation in the representation of artworks and institutions, these results suggest that there may be discursive norms at work in the field of online contemporary art magazines which regulate the use of verbs and modifiers in the evaluation of artists.

Keywords: contemporary art, corpus linguistics, critical discourse analysis, symbolic capital

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Authors: W. I. Mazyan, A. Ahmadi, M. Hoorfar

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Objectives/Scope: This paper proposes a mathematical model for calculating the solid-gas separation efficiency in cyclones. This model provides better agreement with experimental results compared to existing mathematical models. Methods: The separation ratio efficiency, ϵsp, is evaluated by calculating the outlet to inlet count ratio. Similar to mathematical derivations in the literature, the inlet and outlet particle count were evaluated based on Eulerian approach. The model also includes the external forces acting on the particle (i.e., centrifugal and drag forces). In addition, the proposed model evaluates the exact length that the particle travels inside the cyclone for the evaluation of number of turns inside the cyclone. The separation efficiency model derivation using Stoke’s law considers the effect of the inlet tangential velocity on the separation performance. In cyclones, the inlet velocity is a very important factor in determining the performance of the cyclone separation. Therefore, the proposed model provides accurate estimation of actual cyclone separation efficiency. Results/Observations/Conclusion: The separation ratio efficiency, ϵsp, is studied to evaluate the performance of the cyclone for particles ranging from 1 microns to 10 microns. The proposed model is compared with the results in the literature. It is shown that the proposed mathematical model indicates an error of 7% between its efficiency and the efficiency obtained from the experimental results for 1 micron particles. At the same time, the proposed model gives the user the flexibility to analyze the separation efficiency at different inlet velocities. Additive Information: The proposed model determines the separation efficiency accurately and could also be used to optimize the separation efficiency of cyclones at low cost through trial and error testing, through dimensional changes to enhance separation and through increasing the particle centrifugal forces. Ultimately, the proposed model provides a powerful tool to optimize and enhance existing cyclones at low cost.

Keywords: cyclone efficiency, solid-gas separation, mathematical model, models error comparison

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Authors: L. Freeborn

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This paper discusses the application of complex dynamic system theory (DST) to the study of individual differences in second language development. This transdisciplinary framework allows researchers to view the trajectory of language development as a dynamic, non-linear process. A DST approach views language as multi-componential, consisting of multiple complex systems and nested layers. These multiple components and systems continuously interact and influence each other at both the macro- and micro-level. Dynamic systems theory aims to explain and describe the development of the language system, rather than make predictions about its trajectory. Such a holistic and ecological approach to second language development allows researchers to include various research methods from neurological, cognitive, and social perspectives. A DST perspective would involve in-depth analyses as well as mixed methods research. To illustrate, a neurobiological approach to second language development could include non-invasive neuroimaging techniques such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) to investigate areas of brain activation during language-related tasks. A cognitive framework would further include behavioural research methods to assess the influence of intelligence and personality traits, as well as individual differences in foreign language aptitude, such as phonetic coding ability and working memory capacity. Exploring second language development from a DST approach would also benefit from including perspectives from the field of applied linguistics, regarding the teaching context, second language input, and the role of affective factors such as motivation. In this way, applying mixed research methods from neurobiological, cognitive, and social approaches would enable researchers to have a more holistic view of the dynamic and complex processes of second language development.

Keywords: dynamic systems theory, mixed methods, research design, second language development

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Authors: Sadman Durlov, Aditya Ganesh-Ram, Hamidreza Hekmatjou, Md Najmus Salehin, Nora Shayesteh Ameri

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In the field of additive manufacturing, tungsten stands out for its exceptional resistance to high temperatures, making it an ideal candidate for use in extreme conditions. However, its inherent brittleness and vulnerability to thermal cracking pose significant challenges to its manufacturability. This study explores the microstructural evolution of tungsten processed through layer-wise rolling in laser powder bed fusion additive manufacturing, utilizing a comprehensive approach that combines advanced simulation techniques with empirical research. We aim to uncover the complex processes of plastic deformation and microstructural transformations, with a particular focus on the dynamics of grain size, boundary evolution, and phase distribution. Our methodology employs a combination of simulation and experimental data, allowing for a detailed comparison that elucidates the key mechanisms influencing microstructural alterations during the rolling process. This approach facilitates a deeper understanding of the material's behavior under additive manufacturing conditions, specifically in terms of deformation and recrystallization. The insights derived from this research not only deepen our theoretical knowledge but also provide actionable strategies for refining manufacturing parameters to improve the tungsten components' mechanical properties and functional performance. By integrating simulation with practical experimentation, this study significantly enhances the field of materials science, offering a robust framework for the development of durable materials suited for challenging operational environments. Our findings pave the way for optimizing additive manufacturing techniques and expanding the use of tungsten across various demanding sectors.

Keywords: additive manufacturing, layer wise rolling, refractory materials, in-situ microstructure modifications

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Authors: Iva Hereitova, Miroslav Svatek, Vit Novacek

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Background and Aim: Autonomic imbalance is one of the complications for immobilized patients in the acute stage after a stroke. The predominance of sympathetic activity significantly increases cardiac activity. The technique of glenohumeral joint approximation may contribute in a non-pharmacological way to the regulation of blood pressure and heart rate in patients in this risk group. The aim of the study was to evaluate the effect of glenohumeral joint approximation on the change in heart rate and blood pressure in immobilized patients in the acute phase after a stroke. Methods: The experimental study bilaterally evaluated heart rate, systolic and diastolic pressure values before and after glenohumeral joint approximation in 40 immobilized participants (72.6 ± 10.2 years) in the acute phase after stroke. The experimental group was compared with 40 healthy participants in the control group (68.6 ± 14.2 years). An SpO2 vital signs monitor and a validated Microlife WatchBP Office blood pressure monitor were used for evaluation. Statistical processing and evaluation were performed in MATLAB R2019 (The Math Works®, Inc., Natick, MA, USA). Results: Approximation of the glenohumeral joint resulted in a statistically significant decrease in systolic and diastolic pressure. An average decrease in systolic pressure for individual groups ranged from 8.2 to 11.3 mmHg (p <0.001). For diastolic pressure, the average decrease ranged from 5.0 - 14.2 mmHg (p <0.001). There was a statistically significant reduction in heart rate (p <0.01) only in patients after ischemic stroke in the inferior cerebral artery. There was the average decrease in heart rate of 3.9 beats per minute (median 4 beats per minute). Conclusion: Approximation of the glenohumeral joint leads to a statistically significant decrease in systolic and diastolic pressure in immobilized patients in the acute phase after stroke.

Keywords: Aproximation technique, Cardiovaskular system, Glenohumeral joint, Stroke

Procedia PDF Downloads 193

Authors: Bouchou Aïssa, Mohamed Akbi

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Contact materials used for electrical breakers are often made with silver alloys. Mechanical and thermo dynamical properties as well as electron emission of such complicated alloys present a lack of reliable and accurate experimental data. This paper deals mainly with electron work function (EWF) measurements about silver-metal oxide (Ag-MeO) electrical contacts (Ag-ZnO (92/8), before and after surface heat treatments at 296 K  813 K, under UHV conditions (residual gas pressure of 1.4 x 10-7 mbar). The electron work function (EWF) of silver zinc oxide materials was measured photoelectrically, using both Fowler’s method of isothermal curves and linearized Fowler plots. In this paper, we present the development of a method for measuring photoelectric work function of contact materials. Also reported in this manuscript are the results of experimental work whose purpose has been the buildup of a reliable photoelectric system and associated monochromatic ultra-violet radiations source, and the photoelectric measurement of the electron work functions (EWF) of contact materials. In order to study the influence of annealing temperature on the EWF, a vacuum furnace was used for heating the metallic samples up to 800 K. The EWF of the silver – zinc oxide materials were investigated to study the influence of annealing temperature on the EWF. In the present study, the photoelectric measurements about Ag-ZnO(92/8) contacts have shown a linear decrease of the EWF with increasing temperature, i.e. the temperature coefficient is constant and negative: for the first annealing # 1, in the temperature range [299 K  823 K]. On the contrary, a linear increase was observed with increasing temperature (i.e. , being constant and positive), for the next annealing # 2, in the temperature range [296 K  813 K]. The EWFs obtained for silver-zinc oxide Ag-ZnO(92/8) show an obvious dependence on the annealing temperature which is strongly associated with the evolution of the arrangement on ZnO nano particles on the Ag-ZnO contact surface as well as surface charge distribution.

Keywords: Photoemission, Electron work function, Fowler methods, Ag-ZnO contact materials, Vacuum heat treatment

Procedia PDF Downloads 407

Authors: A. V. Varfolomeeva, N. S. Tkachenko, A. G. Tishchenko

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The problem of violation of internal validity in studies of psychological structures is considered. The role of epistemological attitudes of researchers in the planning of research within the methodology of the system-evolutionary approach is assessed. Alternative programs of psychological research involving representatives of different biological species are presented. On the example of the results of two research series the variants of solving the problem are discussed.

Keywords: epistemological attitudes, experimental design, validity, psychological structure, learning

Procedia PDF Downloads 105

Authors: Ramin Rezaei, Terry Ng, Abdollah Afjeh

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Near wake development of a wind turbine affects the aerodynamic loads on the tower and the wind turbine. Design considerations of both isolated wind turbines and wind farms must include unsteady wake flow conditions under which the turbines must operate. The consequent aerodynamic loads could lead to over design of wind turbines and adversely affect the cost of wind turbines and, in turn, the cost of energy produced by wind turbines. Reducing the weight of turbine rotors is particularly desirable since larger wind turbine rotors can be utilized without significantly increasing the cost of the supporting structure. Larger rotor diameters produce larger swept areas and consequently greater energy production from the wind thereby reducing the levelized cost of wind energy. To understand the development and structure of the near tower wake of a wind turbine, an experimental study was conducted to describe the flow field of the near wake for both upwind and downwind turbines. The study was conducted under controlled environment of a wind tunnel using a scaled model of a turbine. The NREL 5 MW reference wind turbine was used as a baseline design and was modified as necessary to design and build upwind and downwind scaled wind turbine models. This paper presents the results of the wind tunnel study using turbine models to quantify the near wake of upwind and downwind wind turbine configurations for various lengths of tower-to-turbine spacing. The variations of mean velocity and turbulence are measured using a computer-controlled, traversing hot wire probe. Additionally, smoke flow visualizations were conducted to qualitatively study the wake. The results show a more rapid dissipation of the near wake for an upwind configuration. The results can readily be incorporated into low fidelity system level turbine simulation tools to more accurately account for the wake on the aerodynamic loads of a upwind and downwind turbines.

Keywords: hot wire anemometry, near wake, upwind and downwind turbine. Hot wire anemometry, near wake, upwind and downwind turbine

Procedia PDF Downloads 660

Authors: Masato Koizumi, Yuya Oshio, Ikkoh Funaki

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Magnetoplasma Sail (MPS) is a future spacecraft propulsion that generates high levels of thrust by inducing an artificial magnetosphere to capture and deflect solar wind charged particles in order to transfer momentum to the spacecraft. By injecting plasma in the spacecraft’s magnetic field region, the ring current azimuthally drifts on the equatorial plane about the dipole magnetic field generated by the current flowing through the solenoid attached on board the spacecraft. This ring current results in magnetosphere inflation which improves the thrust performance of MPS spacecraft. In this present study, the ring current was experimentally measured using three Rogowski Current Probes positioned in a circular array about the laboratory model of MPS spacecraft. This investigation aims to determine the detailed structure of ring current through physical experimentation performed under two different magnetic field strengths engendered by varying the applied voltage on the solenoid with 300 V and 600 V. The expected outcome was that the three current probes would detect the same current since all three probes were positioned at equal radial distance of 63 mm from the center of the solenoid. Although experimental results were numerically implausible due to probable procedural error, the trends of the results revealed three pieces of perceptive evidence of the ring current behavior. The first aspect is that the drift direction of the ring current depended on the strength of the applied magnetic field. The second aspect is that the diamagnetic current developed at a radial distance not occupied by the three current probes under the presence of solar wind. The third aspect is that the ring current distribution varied along the circumferential path about the spacecraft’s magnetic field. Although this study yielded experimental evidence that differed from the original hypothesis, the three key findings of this study have informed two critical MPS design solutions that will potentially improve thrust performance. The first design solution is the positioning of the plasma injection point. Based on the implication of the first of the three aspects of ring current behavior, the plasma injection point must be located at a distance instead of at close proximity from the MPS Solenoid for the ring current to drift in the direction that will result in magnetosphere inflation. The second design solution, predicated by the third aspect of ring current behavior, is the symmetrical configuration of plasma injection points. In this study, an asymmetrical configuration of plasma injection points using one plasma source resulted in a non-uniform distribution of ring current along the azimuthal path. This distorts the geometry of the inflated magnetosphere which minimizes the deflection area for the solar wind. Therefore, to realize a ring current that best provides the maximum possible inflated magnetosphere, multiple plasma sources must be spaced evenly apart for the plasma to be injected evenly along its azimuthal path.

Keywords: Magnetoplasma Sail, magnetosphere inflation, ring current, spacecraft propulsion

Procedia PDF Downloads 301

Authors: Wen Hsin Hsu, Pin Lin

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Objective: Thirst discomfort is the most common yet often overlooked symptom in patients in the intensive care unit (ICU), with an incidence rate of 69.8%. If not properly cared for, it can easily lead to irritability, affect sleep quality, and increase the incidence of delirium, thereby extending the length of hospital stay. Research points out that the sensation of coldness is an effective strategy to alleviate thirst. Using a combined care approach for thirst can prolong the sensation of coldness in the mouth and reduce thirst discomfort. Therefore, it needs to be further analyzed and its effectiveness reviewed. Methods: This study uses systematic literature review and meta-analysis methodologies and searched databases including PubMed, MEDLINE, EMBASE, Cochrane, CINAHL, and two Chinese databases (CEPS and CJTD) based on keywords. JBI was used to appraise the quality of the literature. RevMen 5.4 software package was used, and Fix Effect Model was applied for data analysis. We selected experimental articles, including those in English and Chinese, that met the inclusion and exclusion criteria. Three research articles were included in total, with a sample size of 416 people. Two were randomized controlled trials, and one was a quasi-experimental design. Results: The results show that the combined care for thirst, which includes ice water spray or oral swab wipes, menthol mouthwash, and lip balm, can significantly relieve thirst intensity MD=-1.36 (3 studies, 95% CI (-1.77, -0.95), p <0.001) and thirst distress MD=-0.71 (2 studies, 95% CI (-1.32, -0.10), p =0.02). Therefore, it is recommended that medical staff identify high-risk groups for thirst early on. Implications for Practice: For patients who cannot eat orally, providing combined care for thirst can increase oral comfort and improve the quality of care.

Keywords: thirst bundle care, intensive care units, meta-analysis, ice water spray, menthol

Procedia PDF Downloads 53

Authors: A. Aboubakr, E. Fehling, S. A. Mourad, M. Omar

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Wind energy is one of the most effective renewable sources especially offshore wind energy although offshore wind technology is more costly to produce. It is well known that offshore wind energy can potentially be very cheap once infrastructure and researches improve. Laterally, the trend is to construct offshore wind energy to generate the electricity form wind. This leads to intensive research in order to improve the infrastructures. Offshore wind energy is the construction of wind farms in bodies of water to generate electricity from wind. The most important part in offshore wind turbine structure is the foundation and its connection with the wind tower. This is the main difference between onshore and offshore structures. Grouted connection between the foundation and the wind tower is the most important part of the building process when constructing wind offshore turbines. Most attention should be paid to the actual grout connection as this transfers the loads safely from tower to foundations and the soil also. In this paper, finite element analyses have been carried out for studying the behaviour of offshore grouted connection for wind turbine structures. ATENA program have been used for non-linear analysis simulation of the real structural behavior thus demonstrating the crushing, cracking, contact between the two materials and steel yielding. A calibration of the material used in the simulation has been carried out assuring an accurate model of the used material by ATENA program. This calibration was performed by comparing the results from the ATENA program with experimental results to validate the material properties used in ATENA program. Three simple patch test models with different properties have been performed. The research is concluded with a result that the calibration showing a good agreement between the ATENA program material behaviors and the experimental results.

Keywords: grouted connection, 3D modeling, finite element analysis, offshore wind energy turbines, stresses

Procedia PDF Downloads 516

Authors: M. A. Wijewardane, S. A. N. C. Sudasinghe, H. K. G. Punchihewa, W. K. D. L. Wickramasinghe, S. A. Philip, M. R. S. U. Kumara

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Visual comfort is one of the major parameters that can be taken to measure the human comfort in any environment. If the provided illuminance level in a working environment does not meet the workers visual comfort, it will lead to eye-strain, fatigue, headache, stress, accidents and finally, poor productivity. However, improvements in lighting do not necessarily mean that the workplace requires more light. Unnecessarily higher illuminance levels will also cause poor visual comfort and health risks. In addition, more power consumption on lighting will also result in higher energy costs. So, during this study, visual comfort and the illuminance requirement for the workers in textile/apparel industry were studied to perform different tasks (i.e. cutting, sewing and knitting) at their workplace. Experimental studies were designed to identify the optimum illuminance requirement depending upon the varied fabric colour and type and finally, energy saving potentials due to controlled illuminance level depending on the workforce requirement were analysed. Visual performance of workers during the sewing operation was studied using the ‘landolt ring experiment’. It was revealed that around 36.3% of the workers would like to work if the illuminance level varies from 601 lux to 850 lux illuminance level and 45.9% of the workers are not happy to work if the illuminance level reduces less than 600 lux and greater than 850 lux. Moreover, more than 65% of the workers who do not satisfy with the existing illuminance levels of the production floors suggested that they have headache, eye diseases, or both diseases due to poor visual comfort. In addition, findings of the energy analysis revealed that the energy-saving potential of 5%, 10%, 24%, 8% and 16% can be anticipated for fabric colours, red, blue, yellow, black and white respectively, when the 800 lux is the prevailing illuminance level for sewing operation.

Keywords: Landolt Ring experiment, lighting energy consumption, illuminance, textile and apparel industry, visual comfort

Procedia PDF Downloads 196

Authors: Saiada Fuadi Fancy, Fahim Ahmed, Shofiq Ahmed, Raquib Ahsan

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The worldwide use of reinforced concrete construction stems from the wide availability of reinforcing steel as well as concrete ingredients. However, concrete construction requires a certain level of technology, expertise, and workmanship, particularly, in the field during construction. As a supporting technology for a concrete column or wall construction, kicker is cast as part of the slab or foundation to provide a convenient starting point for a wall or column ensuring integrity at this important junction. For that reason, a comprehensive study was carried out here to investigate the behavior of reinforced concrete frame with different kicker parameters. To achieve this objective, six half-scale specimens of portal reinforced concrete frame with kickers and one portal frame without kicker were constructed according to common practice in the industry and subjected to cyclic incremental horizontal loading with sustained gravity load. In this study, the experimental data, obtained in four deflections controlled cycle, were used to evaluate the behavior of kickers. Load-displacement characteristics were obtained; maximum loads and deflections were measured and assessed. Finally, the test results of frames constructed with three different types of kicker thickness were compared with the kickerless frame. Similar crack patterns were observed for all the specimens. From this investigation, specimens with kicker thickness 3″ were shown better results than specimens with kicker thickness 1.5″, which was specified by maximum load, stiffness, initiation of first crack and residual displacement. Despite of better performance, it could not be firmly concluded that 4.5″ kicker thickness is the most appropriate one. Because, during the test of that specimen, separation of dial gauge was needed. Finally, comparing with kickerless specimen, it was observed that performance of kickerless specimen was relatively better than kicker specimens.

Keywords: crack, cyclic, kicker, load-displacement

Procedia PDF Downloads 310

Authors: Bharti Garg, Ashleigh Cousins, Pauline Pearson, Vincent Verheyen, Paul Feron

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The presence of SO₂ in power plant flue gases makes flue gas desulfurization (FGD) an essential requirement prior to post combustion CO₂ (PCC) removal facilities. Although most of the power plants worldwide deploy FGD in order to comply with environmental regulations, generally the achieved SO₂ levels are not sufficiently low for the flue gases to enter the PCC unit. The SO₂ level in the flue gases needs to be less than 10 ppm to effectively operate the PCC installation. The existing FGD units alone cannot bring down the SO₂ levels to or below 10 ppm as required for CO₂ capture. It might require an additional scrubber along with the existing FGD unit to bring the SO₂ to the desired levels. The absence of FGD units in Australian power plants brings an additional challenge. SO₂ concentrations in Australian power station flue gas emissions are in the range of 100-600 ppm. This imposes a serious barrier on the implementation of standard PCC technologies in Australia. CSIRO’s developed CS-Cap process is a unique solution to capture SO₂ and CO₂ in a single column with single absorbent which can potentially bring cost-effectiveness to the commercial deployment of carbon capture in Australia, by removing the need for FGD. Estimated savings of removing SO₂ through a similar process as CS-Cap is around 200 MMUSD for a 500 MW Australian power plant. Pilot plant trials conducted to generate the proof of concept resulted in 100% removal of SO₂ from flue gas without utilising standard limestone-based FGD. In this work, removal of absorbed sulfur from aqueous amine absorbents generated in the pilot plant trials has been investigated by reactive crystallisation and thermal reclamation. More than 95% of the aqueous amines can be reclaimed back from the sulfur loaded absorbent via reactive crystallisation. However, the recovery of amines through thermal reclamation is limited and depends on the sulfur loading on the spent absorbent. The initial experimental work revealed that reactive crystallisation is a better fit for CS-Cap’s sulfur-rich absorbent especially when it is also capable of generating K₂SO₄ crystals of highly saleable quality ~ 99%. Initial cost estimation carried on both the technologies resulted in almost similar capital expenditure; however, the operating cost is considerably higher in thermal reclaimer than that in crystalliser. The experimental data generated in the laboratory from both the regeneration techniques have been used to generate the simulation model in Aspen Plus. The simulation model illustrates the economic benefits which could be gained by removing flue gas desulfurization prior to standard PCC unit and replacing it with a CS-Cap absorber column co-capturing CO₂ and SO₂, and it's absorbent regeneration system which would be either reactive crystallisation or thermal reclamation.

Keywords: combined capture, cost analysis, crystallisation, CS-Cap, flue gas desulfurisation, regeneration, sulfur, thermal reclamation

Procedia PDF Downloads 115

Authors: Amir Sattari, Mac Panah, Naeim Rashidfarokhi

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To enhance the mixing of fluid in a rectangular enclosure with a circular inlet and outlet, an energy-efficient approach is further investigated through computational fluid dynamics (CFD). Particle image velocimetry (PIV) measurements help confirm that the pulsation of the inflow velocity improves the mixing performance inside the enclosure considerably without increasing energy consumption. In this study, multiple CFD simulations with different turbulent models were performed. The results obtained were compared with experimental PIV results. This study investigates small-scale representations of flow patterns in a ventilated rectangular room. The objective is to validate the concept of an energy-efficient ventilation strategy with improved thermal comfort and reduction of stagnant air inside the room. Experimental and simulated results confirm that through pulsation of the inflow velocity, strong secondary vortices are generated downstream of the entrance wall-jet. The pulsatile inflow profile promotes a periodic generation of vortices with stronger eddies despite a relatively low inlet velocity, which leads to a larger boundary layer with increased kinetic energy in the occupied zone. A real-scale study was not conducted; however, it can be concluded that a constant velocity inflow profile can be replaced with a lower pulsated flow rate profile while preserving the mixing efficiency. Among the turbulent CFD models demonstrated in this study, SST-kω is most advantageous, exhibiting a similar global airflow pattern as in the experiments. The detailed near-wall velocity profile is utilized to identify the wall-jet instabilities that consist of mixing and boundary layers. The SAS method was later applied to predict the turbulent parameters in the center of the domain. In both cases, the predictions are in good agreement with the measured results.

Keywords: CFD, PIV, pulsatile inflow, ventilation, wall-jet

Procedia PDF Downloads 166

Authors: Ishan Tank, Ashmita Rupal, Sanjay Kumar Sharma

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Concrete, a widely used building material, has cement as its main constituent. An excessive amount of emissions are released into the atmosphere during the manufacture of cement, which is detrimental to the environment. To minimize this problem, innovative materials like geopolymer mortar (GPM) seem to be a better alternative. By using fly ash-based geopolymer instead of standard cement mortar as a binding ingredient, this concept has been successfully applied to the building sector. The advancement of this technology significantly reduces greenhouse gas emissions and helps in source reduction, thereby minimizing pollution of the environment. In order to produce mortar and use this geopolymer mortar in the development of building materials, the current investigation is properly introducing this geopolymeric material, namely fly ash, as a binder in place of standard cement. In the domain of the building material industry, fly ash based geopolymer is a new and optimistic replacement for traditional binding materials because it is both environmentally sustainable and has good durability. The setting behaviour and strength characteristics of fly ash, when mixed with alkaline activator solution with varied concentration of sodium hydroxide solution, alkaline liquids mix ratio, and curing temperature, must be investigated, though, in order to determine its suitability and application in comparison with the traditional binding material, by activating the raw materials, which include various elements of silica and alumina, finer material known as geopolymer mortar is created. The concentration of the activator solution has an impact on the compressive strength of the geopolymer concrete formed. An experimental examination of compressive strength after 7, 14, and 28 days of fly ash-based geopolymer concrete is presented in this paper. Furthermore, the process of geopolymerization largely relies on the curing temperature. So, the setting time of Geopolymer mortar due to different curing temperatures has been studied and discussed in this paper.

Keywords: geopolymer mortar, setting time, flyash, compressive strength, binder material

Procedia PDF Downloads 53