Search results for: functional theory of language

Authors: Tassia Batista Pessato, Francielli Pires Ribeiro Morais, Fernanda Guimaraes Drummond Silva, Flavia Maria Netto

Abstract:

Proteins and phenolic compounds can interact mainly by hydrophobic interactions. Those interactions may lead to structural changes in both molecules, which in turn could affect positively or negatively their functional and nutritional properties. Here, the structural changes of whey proteins (WPI) due to interaction with caffeic acid (CA) were investigated by intrinsic and extrinsic fluorescence. The effects of protein-phenolic compounds interactions on the total phenolic content and antioxidant activity were also assessed. The WPI-CA complexes were obtained by mixture of WPI and CA stock solutions in deionized water. The complexation was carried out at room temperature during 60 min, using 0.1 M NaOH to adjust pH at 7.0. The WPI concentration was fixed at 5 mg/mL, whereas the CA concentration varied in order to obtain four different WPI:CA molar relations (1:1; 2:1; 5:1; 10:1). WPI and phenolic solutions were used as controls. Intrinsic fluorescence spectra of the complexes (mainly due to Trp fluorescence emission) were obtained at λex = 280 nm and the emission intensities were measured from 290 to 500 nm. Extrinsic fluorescence was obtained as the measure of protein surface hydrophobicity (S0) using ANS as a fluorescence probe. Total phenolic content was determined by Folin-Ciocalteau and the antioxidant activity by FRAP and ORAC methods. Increasing concentrations of CA resulted in decreasing of WPI intrinsic fluorescence. The emission band of WPI red shifted from 332 to 354 nm as the phenolic concentration increased, which is related to the exposure of Trp residue to the more hydrophilic environment and unfolding of protein structure. In general, the complexes presented lower S0 values than WPI, suggesting that CA hindered ANS binding to hydrophobic sites of WPI. The total phenolic content in the complexes was lower than the sum of two compounds isolated. WPI showed negligible AA measured by FRAP. However, as the relative concentration of CA increased in the complexes, the FRAP values enhanced, indicating that AA measure by this technique comes mainly from CA. In contrast, the WPI ORAC value (82.3 ± 1.5 µM TE/g) suggest that its AA is related to the capacity of H+ transfer. The complexes exhibited no important improvement of AA measured by ORAC in relation to the isolated components, suggesting complexation partially suppressed AA of the compounds. The results hereby presented indicate that interaction of WPI and CA occurred, and this interaction caused a structural change in the proteins. The complexation can either hide or expose antioxidant sites of both components. In conclusion, although the CA can undergo an AA suppression due to the interaction with proteins, the AA of WPI could be enhanced due to protein unfolding and exposure of antioxidant sites.

Keywords: bioactive properties, milk proteins, phenolic acids, protein-phenolic compounds complexation

Procedia PDF Downloads 533

Authors: Yulan Wu

Abstract:

The spread of fake news on social media has posed significant societal harm to the public and the nation, with its threats spanning various domains, including politics, economics, health, and more. News on social media often covers multiple domains, and existing models studied by researchers and relevant organizations often perform well on datasets from a single domain. However, when these methods are applied to social platforms with news spanning multiple domains, their performance significantly deteriorates. Existing research has attempted to enhance the detection performance of multi-domain datasets by adding single-domain labels to the data. However, these methods overlook the fact that a news article typically belongs to multiple domains, leading to the loss of domain knowledge information contained within the news text. To address this issue, research has found that news records in different domains often use different vocabularies to describe their content. In this paper, we propose a fake news detection framework that combines domain knowledge and expert knowledge. Firstly, it utilizes an unsupervised domain discovery module to generate a low-dimensional vector for each news article, representing domain embeddings, which can retain multi-domain knowledge of the news content. Then, a feature extraction module uses the domain embeddings discovered through unsupervised domain knowledge to guide multiple experts in extracting news knowledge for the total feature representation. Finally, a classifier is used to determine whether the news is fake or not. Experiments show that this approach can improve multi-domain fake news detection performance while reducing the cost of manually labeling domain labels.

Keywords: fake news, deep learning, natural language processing, multiple domains

Procedia PDF Downloads 53

Authors: Alaaeddeen M. Seufi

Abstract:

Many have been published on therapeutic derivatives from living organisms including insects. In addition to traditional maggot therapy, more than 900 therapeutic products were isolated from insects. Most people look at insects as enemies and others believe that insects are friends. Many beneficial insects rather than Honey Bees, Silk Worms and Shellac insect could insure human-insect friendship. In addition, insects could be MicroFactories, Biosensors or Bioreactors. InsectFarm is an amazing example of the applied research that transfers insects from laboratory to market by Prof Mircea Ciuhrii and co-workers. They worked for 18 years to derive therapeutics from insects. Their research resulted in production of more than 30 commercial medications derived from insects (e.g. Imunomax, Noblesse, etc.). Two general approaches were followed to discover drugs from living organisms. Some laboratories preferred biochemical approach to purify components of the innate immune system of insects and insect metabolites as well. Then the purified components could be tested for many therapeutic trials. Other researchers preferred molecular approach based on proteomic studies. Components of the innate immune system of insects were then tested for their medical activities. Our Laboratory team preferred to induce insect immune system (using oral, topical and injection routes of administration), then a transcriptomic study was done to discover the induced genes and to identify specific biomarkers that can help in drug discovery. Biomarkers play an important role in medicine and in drug discovery and development as well. Optimum biomarker development and application will require a team approach because of the multifaceted nature of biomarker selection, validation, and application. This team uses several techniques such as pharmacoepidemiology, pharmacogenomics, and functional proteomics; bioanalytical development and validation; modeling and simulation to improve and refine drug development. Our Achievements included the discovery of four components of the innate immune system of Spodoptera littoralis and Musca domestica. These components were designated as SpliDef (defesin), SpliLec (lectin), SpliCec (cecropin) and MdAtt (attacin). SpliDef, SpliLec and MdAtt were confirmed as antimicrobial peptides, while SpliCec was additionally confirmed as anticancer peptide. Our current research is going on to achieve something in antioxidants and anticoagulants from insects. Our perspective is to achieve something in the mass production of prototypes of our products and to reach it to the commercial level. These achievements are the integrated contributions of everybody in our team staff.

Keywords: AMPs, insect, innate immunitty, therappeutics

Procedia PDF Downloads 362

Authors: Ahmed F. Ghanem, Marwa I. Wahba, Asmaa N. El-Dein, Mohamed A. EL-Raey, Ghada E. A. Awad

Abstract:

Numerous attempts are being performed in order to formulate suitable packaging materials for the meat products. However, to the best of our knowledge, the incorporation of the free hibiscus extract or its microcapsules in the pure polyvinyl alcohol (PVA) matrix as packaging materials for the meats is seldom reported. Therefore, this study aims at the protection of the aqueous crude extract of the hibiscus flowers utilizing the spry drying encapsulation technique. Results of the Fourier transform infrared (FTIR), the scanning electron microscope (SEM), and the particle size analyzer confirmed the successful formation of the assembled capsules via strong interactions, the spherical rough microparticles, and the particle size of ~ 235 nm, respectively. Also, the obtained microcapsules enjoy higher thermal stability than the free extract. Then, the obtained spray-dried particles were incorporated into the casting solution of the pure PVA film with a concentration of 10 wt. %. The segregated free-standing composite films were investigated, compared to the neat matrix, with several characterization techniques such as FTIR, SEM, thermal gravimetric analysis (TGA), mechanical tester, contact angle, water vapor permeability, and oxygen transmission. The results demonstrated variations in the physicochemical properties of the PVA film after the inclusion of the free and the extract microcapsules. Moreover, biological studies emphasized the biocidal potential of the hybrid films against the microorganisms contaminating the meat. Specifically, the microcapsules imparted not only antimicrobial but also antioxidant activities to the PVA matrix. Application of the prepared films on the real meat samples displayed a low bacterial growth with a slight increase in the pH over the storage time which continued up to 10 days at 4 oC, as further evidence to the meat safety. Moreover, the colors of the films did not significantly changed except after 21 days indicating the spoilage of the meat samples. No doubt, the dual-functional of the prepared composite films pave the way towards combined active and smart food packaging applications. This would play a vital role in the food hygiene, including also the quality control and the assurance.

Keywords: PVA, hibiscus, extraction, encapsulation, active packaging, smart and intelligent packaging, meat spoilage

Procedia PDF Downloads 77

Authors: Safa Abdussalam

Abstract:

Adolescence is a period of storm and stress. It is a transitional period. Adolescents undergo a lot of changes physically, emotionally and mentally during adolescence. Physical changes include puberty, sexual maturation, changes in height, weight, hormonal changes, changes in body image, changes in brain and in sexuality. Changes also occur in their cognition. According to Piaget’s theory, adolescent enter formal operational stage and engage in hypothetical-deductive reasoning. Main characteristic of adolescent cognition is adolescent egocentrism: imaginary audience and personal fable. One of the most common struggle majority of adolescents face is the conflict between parent and adolescent. They often complain that parents do not understand them/their situation. Common topics of conflict include identity crisis, issues with personal freedom and issues over personal preferences. Conflict resolution refers to solving conflicts in a healthy way. There is a lack of resources in dealing with such conflicts creatively. To deal with parent-adolescent conflict, a conflict resolution board game is designed. The board game consists of tokens, dice, 10 conflict situation cards and two conflict resolution sheets. Purpose of using a board game is to help adolescents understand the conflict situations and resolutions in a fun, creative and interactive way. It can be used for self-help or even therapists can use it in their clinical practice. The study aims to assess the effectiveness of the board game in dealing with the conflict. Experimental design will be used. Samples include 15 adolescents belonging to age group 10-19. Samples will be divided into two groups: Experimental group and control group. A pre-test and post-test will be conducted. The board game will be demonstrated to the experimental group. Results will be obtained after statistical analysis. Board games are a great way to be used with children and adolescents.

Keywords: adolescent, adolescence, parent-child conflict, conflict resolution

Procedia PDF Downloads 81

Authors: Myriam Castonguay, Florence Vinit

Abstract:

This study aims to gain a better understanding of the lived experience of seven children growing up in a family where another child is severely disabled, informed by family systems theory and the socio-ecological model of development. In depth semi-structured interviews were conducted with seven children who described they everyday life since their brother’s or sister’s diagnosis. Thematic analysis revealed four themes : struggling with loneliness inside the family, supporting the disabled child through its journey, accommodating to a changing routine and keeping a “bubble” for oneself. Brothers and sisters depict a family life characterized by much loneliness, with severe disabilities requiring ongoing care and prolonged hospitalizations. In the midst of adversity, siblings describe themselves as highly committed to supporting the disabled child and to preserve family cohesion, even if that means getting exposed to emotionally challenging situations and adjusting their daily routine frequently. Children recount that keeping up with schoolwork and leisure activities of their own is central to their well-being. Having a space where one can reconnect with his ordinary life as a kid is also deemed very important. This study reminds us that more needs to be done to counteract the loneliness experienced by siblings through the family experience of disability. Family members and clinicians need to be extra vigilant to ensure siblings’ needs don’t go unnoticed or dismissed, as it may be difficult for this population of children to voice their own experience and needs. Family, school and other actors in the community may help brothers and sisters pursue their personal dreams, goals and projects, to continue experiencing well-being despite adverse life circumstances.

Keywords: sibling’s lived experience of disability, sibling’s needs at various levels of the ecosystem, family adjustment to the disability experience, supporting family wellness through the disability experience

Procedia PDF Downloads 100

Authors: J. K Adedeji, O. H Olowomofe, C. O Alo, S.T Ijatuyi

Abstract:

The issue of high blood sugar level, the effects of which might end up as diabetes mellitus, is now becoming a rampant cardiovascular disorder in our community. In recent times, a lack of awareness among most people makes this disease a silent killer. The situation calls for urgency, hence the need to design a device that serves as a monitoring tool such as a wrist watch to give an alert of the danger a head of time to those living with high blood glucose, as well as to introduce a mechanism for checks and balances. The neural network architecture assumed 8-15-10 configuration with eight neurons at the input stage including a bias, 15 neurons at the hidden layer at the processing stage, and 10 neurons at the output stage indicating likely symptoms cases. The inputs are formed using the exclusive OR (XOR), with the expectation of getting an XOR output as the threshold value for diabetic symptom cases. The neural algorithm is coded in Java language with 1000 epoch runs to bring the errors into the barest minimum. The internal circuitry of the device comprises the compatible hardware requirement that matches the nature of each of the input neurons. The light emitting diodes (LED) of red, green, and yellow colors are used as the output for the neural network to show pattern recognition for severe cases, pre-hypertensive cases and normal without the traces of diabetes mellitus. The research concluded that neural network is an efficient Accu-Chek design tool for the proper monitoring of high glucose levels than the conventional methods of carrying out blood test.

Keywords: Accu-Check, diabetes, neural network, pattern recognition

Procedia PDF Downloads 134

Authors: Kunal Mankodi, Sudhir Pandey

Abstract:

This study aims to assess the factors that play a role in setting up and running a social enterprise driven towards sustainability at the intersection of energy, environment, and poverty alleviation. According to the theory of sustainability-oriented innovation (SOI), conventional organisations adapt their processes to focus on sustainability-oriented innovations. On the other hand, social enterprises that are purpose-driven are also influenced by the context of innovation, which need due attention. This paper presents an account of innovation at Oorja - an Indian social enterprise operating with a farming-as-a-service business model. It aims to illustrate the contexts in which the innovative solutions were developed to work at an intersection between agriculture and clean energy, thereby allowing small farmers access to efficient solutions in the agriculture cycle. Primary data was collected through in-depth interviews, and secondary data was collected from company sources. The study finds that in the case of a social enterprise, the definition of innovation assumes a wider scope by going beyond the introduction of a new product/service. The context of innovation for social enterprise is affected by organisational factors such as organisation’s philosophical mindset, behaviour towards innovation, organisation’s capabilities, regulatory environment, and customer receptiveness. Additionally, the study also finds that the context of innovation for a social enterprise is affected by its organizational structure. A majority of these organizational factors are, in turn, affected by individual (Founder’s) factors such as the founder’s formative years, education, direct exposure to relevant issues, complementary skills of co-founders, and a common calling.

Keywords: context of innovation, social enterprise, sustainability oriented innovations, emerging markets, agriculture

Procedia PDF Downloads 123

Authors: Y. I. Tretyakova, S. G. Shulkina, T. Y. Kravtsova, A. A. Antipova, N. Y. Kolomeets

Abstract:

The research aimed to assess the functional significance of tumor necrosis factor-alpha (TNF-α) gene polymorphism at the -308G/A (rs1800629) region and vascular endothelial growth factor A (VEGFA) gene polymorphism at the -634G/C (rs 2010963) region in the development of ulcerative colitis (UC), focusing on patients from the Perm region, Russia. We examined 70 UC patients and 50 healthy donors during the active phase of the disease. Our focus was on TNF-α and VEGF concentration in the blood serum, as well as TNF-α and VEGFA gene polymorphisms at the -308G/А and -634G/C regions, respectively. We found that TNF-α and VEGF levels were significantly higher in patients with severe UC and high endoscopic activity compared to those with milder forms of the disease and low endoscopic activity. These tests could serve as additional non-invasive markers for assessing mucosal damage in the large intestine of UC patients. The frequency of allele variations in the TNF-α gene -308G/A (rs1800629) revealed a significantly higher occurrence of the unfavorable homozygote AA in UC patients compared to donors. Additionally, the major allele G and the allele pair GG were more frequent in patients with mild to moderate disease and 1-2 degree of endoscopic activity than in those with severe UC and 3-4 degree of endoscopic activity (χ2=14.19; p=0.000). We also observed a mutant allele A and the unfavorable homozygote AA associated with severe progressive UC. The occurrence of the mutant allele increased the risk of severe UC by 5 times (OR 5.03; CI 12.07-12.21). We did not find any significant differences in the frequency of the CC homozygote (χ2=1.02; p=0.6; OR=1.32) and the mutant allele C of the VEGFA gene -634G/C (rs 2010963) (χ2=0.01; p=0.913; OR=0.97) between groups of UC patients and healthy individuals. However, we detected that the mutant allele C and the unfavorable homozygote CC of the VEGFA gene were associated with more severe endoscopic changes in the colonic mucosa of UC patients (χ2=25,76; р=0,000; OR=0,15). The presence of the mutant allele increased the risk of severe UC by 6 times (OR 6,78; CI 3,13–14,7). We found a direct correlation between TNF-α and VEGFA gene polymorphisms, increased production of the same factors, disease severity, and endoscopic activity (р=0.000). Therefore, the presence of the mutant allele A and homozygote AA of the TNF-α gene at the -308G/A region and the mutant allele C and homozygote CC of the VEGFA gene at the -634G/C region are associated with risks related to an unfavorable clinical course of UC, frequent recurrences, and rapid progression. These findings should be considered when making prognoses regarding the clinical course of the disease and selecting treatment strategies. The presence of the homozygote AA in the TNF-α gene (rs1800629) is considered a sign of genetic predisposition to UC.

Keywords: gene polymorphism, TNF-α, ulcerative colitis, VEGF

Procedia PDF Downloads 61

Authors: Khadijah Saeed Khan

Abstract:

One of the major current societal issues of Swedish society is to integrate newcomer refugees well into the host society. The cultural integration issue is one of the under debated topic in the literature, and this study intends to meet this gap from the Swedish perspective. The purpose of this study is to explore the role and types of cultural landscapes of refugee women in Sweden and how these landscapes help or hinder the settlement process. The cultural landscapes are referred to as a set of multiple cultural activities or practices which refugees perform in a specific context and circumstances (i.e., being in a new country) to seek, share or use relevant information for their settlement. Information plays a vital role in various aspects of newcomers' lives in a new country. This article has an intention to highlight the importance of multiple cultural landscapes as a source of information (regarding employment, language learning, finding accommodation, immigration matters, health concerns, school and education, family matters, and other everyday matters) for refugees to settle down in Sweden. Some relevant theories, such as information landscapes and socio-cultural theories, are considered in this study. A qualitative research design is employed, including semi-structured deep interviews and participatory observation with 20 participants. The initial findings show that the refugee women encounter many information-related and integration-related challenges in Sweden and have built a network of cultural landscapes in which they practice various co-ethnic cultural and religious activities at different times of the year. These landscapes help them to build a sense of belonging with people from their own or similar land and assist them to seek and share relevant information in everyday life in Sweden.

Keywords: cultural integration, cultural landscapes, information, women refugees

Procedia PDF Downloads 129

Authors: Eli Buchbinder

Abstract:

Dialectics theory perceives two or more forces or themes as mutually opposed and negating on the one hand and as interdependent for their definition, existence, and resolution on the other. Such opposites might never be fully reconciled but might, simultaneously, continue to produce a higher level of integration and synthesis as well as tension, contradictions, and paradoxes. The identity of social work is constructed by poles; an understanding that emerges through key concepts that shape the profession. The key concept of person-in-environment creates dialectical tensions between the psychological versus the social pole. Important examples that reflect this focus on the psychological versus the social nature of human beings. This meta-perspective influences and constructs the implementation of values, ways of intervention, and professional relationships, e.g., creating a conflict between personal/social empowerment and social control and correction as the aims of the profession. Social work is dynamic and changing, with a unique way of perceiving and conceptualizing human behavior. Social workers must be able to face and accept the contradicting elements inherent in practicing social work. The basic philosophy for social work education is a dialectic conceptualization. In light of the above, social work students require dialectics as a critical mode of perception, reflection, and intervention. In the presentation, the focus will be on reflection on teaching students to conceptualize dialectics as a frame when training to be social workers. It is believed that the focus should emphasis two points: 1) the need to assist students to identify poles and to analyze the interrelationships created between them while coping emotionally with the tension and difficulties involved in containing these poles; 2) teaching students to integrate poles as a basis for assessment, planning, and intervention.

Keywords: professional ontology, a generic social work education, skills and values of social work, reflecting on social work teaching methods

Procedia PDF Downloads 73

Authors: Sergio Andres Rojas, Julian Benavides Franco, Juan Tomas Sayago

Abstract:

An increasing amount of research demonstrates how market mood affects financial markets, but their primary goal is to demonstrate how Trump's tweets impacted US interest rate volatility. Following that lead, this work evaluates the effect that Trump's tweets had during his presidency on local and international stock markets, considering not just volatility but the direction of the movement. Three indexes for Trump's tweets were created relating his activity with movements in the S&P500 using natural language analysis and machine learning algorithms. The indexes consider Trump's tweet activity and the positive or negative market sentiment they might inspire. The first explores the relationship between tweets generating negative movements in the S&P500; the second explores positive movements, while the third explores the difference between up and down movements. A pseudo-investment strategy using the indexes produced statistically significant above-average abnormal returns. The findings also showed that the pseudo strategy generated a higher return in the local market if applied to intraday data. However, only a negative market sentiment caused this effect on daily data. These results suggest that the market reacted primarily to a negative idea reflected in the negative index. In the international market, it is not possible to identify a pervasive effect. A rolling window regression model was also performed. The result shows that the impact on the local and international markets is heterogeneous, time-changing, and differentiated for the market sentiment. However, the negative sentiment was more prone to have a significant correlation most of the time.

Keywords: market sentiment, Twitter market sentiment, machine learning, natural dialect analysis

Procedia PDF Downloads 54

Authors: Justin D. Olmanson, Fitsum Abebe, Valerie Jones, Eric Kyle, Xianquan Liu, Katherine Robbins, Guieswende Rouamba

Abstract:

The history of education technology--and designing, adapting, and adopting technologies for use in educational spaces--is nuanced, complex, and dynamic. Yet, despite a range of continually emerging technologies, the design and development process often yields results that appear quite similar in terms of affordances and interactions. Through this study we (1) verify the extent to which designs have been constrained, (2) consider what might account for it, and (3) offer a way forward in terms of how we might identify and strategically sidestep these influences--thereby increasing the diversity of our designs with a given technology or within a particular learning domain. We begin our inquiry from the perspective that a host of co-influencing elements, fields, and meta narratives converge on the education technology design process to exert a tangible, often homogenizing effect on the resultant designs. We identify several elements that influence design in often implicit or unquestioned ways (e.g. curriculum, learning theory, economics, learning context, pedagogy), we describe our methodology for identifying the elemental positionality embedded in a design, we direct our analysis to a particular subset of technologies in the field of literacy, and unpack our findings. Our early analysis suggests that the majority of education technologies designed for use/used in US public schools are heavily influenced by a handful of mainstream theories and meta narratives. These findings have implications for how we approach the education technology design process--which we use to suggest alternative methods for designing/ developing with emerging technologies. Our analytical process and re conceptualized design process hold the potential to diversify the ways emerging and established technologies get incorporated into our designs.

Keywords: curriculum, design, innovation, meta narratives

Procedia PDF Downloads 496

Authors: R. Morbidelli, C. Saltalippi, A. Flammini, A. Garcia-Marin, J. L. Ayuso-Munoz

Abstract:

The climate change, mainly due to greenhouse gas emissions associated to human activities, has been modifying hydrologic processes with a direct effect on air surface temperature that has significantly increased in the last century at global scale. In this context the Mediterranean area is considered to be particularly sensitive to the climate change impacts on temperature indices. An analysis finalized to study the evolution of temperature indices and to check the existence of significant trends in the Umbria Region (Italy) is presented. Temperature data were obtained by seven meteorological stations uniformly distributed in the study area and characterized by very long series of temperature observations (at least 60 years) spanning the 1924-2015 period. A set of 39 temperature indices represented by monthly and annual mean, average maximum and average minimum temperatures, has been derived. The trend analysis was realized by applying the non-parametric Mann-Kendall test, while the non-parametric Pettit test and the parametric Standard Normal Homogeneity test (SNHT) were used to check the presence of breakpoints or in-homogeneities due to environmental changes/anthropic activity or climate change effects. The Umbria region, in agreement with other recent studies exploring the temperature behavior in Italy, shows a general increase in all temperature indices, with the only exception of Gubbio site that exhibits very light negative trends or absence of trend. The presence of break points and in-homogeneity was widely explored through the selected tests and the results were checked on the basis of the well-known metadata of the meteorological stations.

Keywords: reception theory, reading, literary translation, horizons of expectation, reader

Procedia PDF Downloads 144

Authors: Li-Ching Hung

Abstract:

The lack of empirical research on portfolio assessment in aboriginal EFL English classes of junior high schools in Taiwan may inhibit EFL teachers from appreciating the utility of this alternative assessment approach. This study addressed the following research questions: 1) understand how aboriginal EFL students and instructors of junior high schools in Taiwan perceive portfolio assessment, and 2) how portfolio assessment affects Taiwanese aboriginal EFL students’ learning outcomes. Ten classes of five junior high schools in Taiwan (from different regions of Taiwan) participated in this study. Two classes from each school joined the study, and each class was randomly assigned as a control group, and one was the experimental group. These five junior high schools consisted of at least 50% of aboriginal students. A mixed research design was utilized. The instructor of each class implemented a portfolio assessment for 15 weeks of the 2015 Fall Semester. At the beginning of the semester, all participants took a GEPT test (pretest), and in the 15th week, all participants took the same level of GEPT test (post-test). Scores of students’ GEPT tests were checked by the researcher as supplemental data in order to understand each student’s performance. In addition, each instructor was interviewed to provide qualitative data concerning students’ general learning performance and their perception of implementing portfolio assessments in their English classes. The results of this study were used to provide suggestions for EFL instructors while modifying their lesson plans regarding assessment. In addition, the empirical data were used as references for EFL instructors implementing portfolio assessments in their classes effectively.

Keywords: assessment, portfolio assessment, qualitative design, aboriginal ESL students

Procedia PDF Downloads 126

Authors: Youlu Huang, Huanjun Jiang

Abstract:

A large number of old masonry buildings built in the last century still remain in the city. It generates the problems of unsafety, obsolescence, and non-habitability. In recent years, many old buildings have been reconstructed through renovating façade, strengthening, and adding floors. However, most projects only provide a solution for a single problem. It is difficult to comprehensively solve problems of poor safety and lack of building functions. Therefore, a comprehensive functional renovation program of adding reinforced concrete frame story at the bottom via integrally lifting the building and then strengthening the building was put forward. Based on field measurement and YJK calculation software, the seismic performance of an actual three-story masonry structure in Shanghai was identified. The results show that the material strength of masonry is low, and the bearing capacity of some masonry walls could not meet the code requirements. The elastoplastic time history analysis of the structure was carried out by using SAP2000 software. The results show that under the 7 degrees rare earthquake, the seismic performance of the structure reaches 'serious damage' performance level. Based on the code requirements of the stiffness ration of the bottom frame (lateral stiffness ration of the transition masonry story and frame story), the bottom frame story was designed. The integral lifting process of the masonry building was introduced based on many engineering examples. The reinforced methods for the bottom frame structure strengthened by the steel-reinforced mesh mortar surface layer (SRMM) and base isolators, respectively, were proposed. The time history analysis of the two kinds of structures, under the frequent earthquake, the fortification earthquake, and the rare earthquake, was conducted by SAP2000 software. For the bottom frame structure, the results show that the seismic response of the masonry floor is significantly reduced after reinforced by the two methods compared to the masonry structure. The previous earthquake disaster indicated that the bottom frame is vulnerable to serious damage under a strong earthquake. The analysis results showed that under the rare earthquake, the inter-story displacement angle of the bottom frame floor meets the 1/100 limit value of the seismic code. The inter-story drift of the masonry floor for the base isolated structure under different levels of earthquakes is similar to that of structure with SRMM, while the base-isolated program is better to protect the bottom frame. Both reinforced methods could significantly improve the seismic performance of the bottom frame structure.

Keywords: old buildings, adding story, seismic strengthening, seismic performance

Procedia PDF Downloads 112

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

Abstract:

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

Procedia PDF Downloads 125

Authors: Harshit Mittal, Neeraj Garg

Abstract:

Hand symbol recognition is a pivotal component in the domain of computer vision, with far-reaching applications spanning sign language interpretation, human-computer interaction, and accessibility. This research paper discusses the approach with the integration of the Canny Edge algorithm and convolutional neural network. The significance of this study lies in its potential to enhance communication and accessibility for individuals with hearing impairments or those engaged in gesture-based interactions with technology. In the experiment mentioned, the data is manually collected by the authors from the webcam using Python codes, to increase the dataset augmentation, is applied to original images, which makes the model more compatible and advanced. Further, the dataset of about 6000 coloured images distributed equally in 5 classes (i.e., 1, 2, 3, 4, 5) are pre-processed first to gray images and then by the Canny Edge algorithm with threshold 1 and 2 as 150 each. After successful data building, this data is trained on the Convolutional Neural Network model, giving accuracy: 0.97834, precision: 0.97841, recall: 0.9783, and F1 score: 0.97832. For user purposes, a block of codes is built in Python to enable a window for hand symbol recognition. This research, at its core, seeks to advance the field of computer vision by providing an advanced perspective on hand sign recognition. By leveraging the capabilities of the Canny Edge algorithm and convolutional neural network, this study contributes to the ongoing efforts to create more accurate, efficient, and accessible solutions for individuals with diverse communication needs.

Keywords: hand symbol recognition, computer vision, Canny edge algorithm, convolutional neural network

Procedia PDF Downloads 48

Authors: Verónica Díaz

Abstract:

A Cartesian graph, as a mathematical object, becomes a tool for configuration of change. Its best comprehension is done through everyday life problem-solving associated with its representation. Despite this, the current educational framework favors general graphs, without consideration of their argumentation. Students are required to find the mathematical function without associating it to the development of graphical language. This research describes the use made by students of configurations made prior to Cartesian graphs with regards to an everyday life problem related to a time and distance variation phenomenon. The theoretical framework describes the function conditions of study and their modeling. This is a qualitative, descriptive study involving six undergraduate case studies that were carried out during the first term in 2016 at University of Los Lagos. The research problem concerned the graphic modeling of a real person’s movement phenomenon, and two levels of analysis were identified. The first level aims to identify local and global graph interpretations; a second level describes the iconicity and referentiality degree of an image. According to the results, students were able to draw no figures before the Cartesian graph, highlighting the need for students to represent the context and the movement of which causes the phenomenon change. From this, they managed Cartesian graphs representing changes in position, therefore, achieved an overall view of the graph. However, the local view only indicates specific events in the problem situation, using graphic and verbal expressions to represent movement. This view does not enable us to identify what happens on the graph when the movement characteristics change based on possible paths in the person’s walking speed.

Keywords: cartesian graphs, higher education, movement modeling, problem solving

Procedia PDF Downloads 207

Authors: Ehosa Peter Ogbeni

Abstract:

Religious conflict and insurgency are staying as growing phenomena globally especially within the West African region: this 'new wars’ in this part of the globe has brought many of its economies to the brink of collapse, creating humanitarian casualties and concerns for the visitors and international community. This ‘ugly’ trend has also affected the social, economic and political life of the West African region. Over the years, various religious and insurgency groups have raised arms against civilians and the government, the most recent extremist group, Boko Haram continues to expand and commit violent acts, such as sporadic suicide bombings and killing of innocent citizens and foreigners within the West African region especially in countries like Nigeria, Cameroon and Chad etc. It would have been expected that academic research focus on investigating the West African region; this is not the situation as most of the research on religious conflict and insurgencies have focused more on other parts of the World. Insurgencies and Religious Conflict studies in West Africa have fallen short of literature and very limited literature covers the activities of Boko Haram arm struggle. This research therefore, aims to fill the gap by investigating the role of Economic Community of West African States (ECOWAS) in managing the growing trend of religious conflicts and insurgency in West African States, by using Boko Haram as a case to review. This research adopted the critical theory paradigm using aspects of qualitative research techniques in carrying out its investigation. The findings of this research will help develop a framework that will aid the (ECOWAS) amongst other stakeholders in managing religious and insurgency motivated conflict.

Keywords: religious conflict, insurgencies, Boko haram, ECOWAS (economics community of West African states), peace building, conflict resolution

Procedia PDF Downloads 311

Authors: Pei-Ying Lo, Jing-Hao Ciou, Kai-Cheng Yang, Jia-Huei Zheng, Shih-Hsiang Huang, Kuen-Chan Lee, Er-Chieh Cho

Abstract:

As-produced CNTs are insoluble in all organic solvents and aqueous solutions have imposed limitations to the use of CNTs. Therefore, how to debundle carbon nanotubes and to modify them for further uses is an important issue. There are several methods for the dispersion of CNTs in water using covalent attachment of hydrophilic groups to the surface of tubes. These methods, however, alter the electronic structure of the nanotubes by disrupting the network of sp2 hybridized carbons. In order to keep the nanotubes’ intrinsic mechanical and electrical properties intact, non-covalent interactions are increasingly being explored as an alternative route for dispersion. Apart from conventional surfactants such as sodium dodecylsulfate (SDS) or sodium dodecylbenzenesulfonate (SDBS) which are highly effective in dispersing CNTs, biopolymers have received much attention as dispersing agents due to the anticipated biocompatibility of the dispersed CNTs. Also, The pyrenyl group is known to interact strongly with the basal plane of graphene via π-stacking. In this study, a highly re-dispersible biopolymer is reported for the synthesis of pyrene-modified poly-L-lysine (PBPL) and poly(D-Glu, D-Lys) (PGLP). To provide the evidence of the safety of the PBPL/CNT & PGLP/CNT materials we use in this study, H1299 and HCT116 cells were incubated with PBPL/CNT & PGLP/CNT materials for toxicity analysis, MTS assays. The results from MTS assays indicated that no significant cellular toxicity was shown in H1299 and HCT116 cells. Furthermore, the fluorescence marker fluorescein isothiocyanate (FITC) was added to PBPL & PGLP dispersions. From the fluorescent measurements showed that the chemical functionalisation of the PBPL/CNT & PGLP/CNT conjugates with the fluorescence marker were successful. The fluorescent PBPL/CNT & PGLP/CNT conjugates could find application in medical imaging. In the next step, the GFP gene is immobilized onto PBPL/CNT conjugates by introducing electrostatic interaction. GFP-transfected cells that emitted fluorescence were imaged and counted under a fluorescence microscope. Due to the unique biocompatibility of PBPL modified CNTs, the GFP gene could be transported into H1299 cells without using antibodies. The applicability of such soluble and chemically functionalised polypeptide/CNT conjugates in biomedicine is currently investigated. We expect that this polypeptide/CNT system will be a safe and multi-functional nanomedical delivery platform and contribute to future medical therapy.

Keywords: carbon nanotube, nanotoxicology, GFP transfection, polypeptide/CNT hybrids

Procedia PDF Downloads 328

Authors: Yingyi Luo

Abstract:

Cross-border commercial surrogacy, where Australians travel overseas to access reproduction through a surrogate mother, is an increasing phenomenon. This paper focuses on the role of Australian surrogacy facilitators, including lawyers, non-for-profit agents, fertility counselors, who act as intermediaries managing cross-border surrogacy arrangements in Australia. It explores the extent to which surrogacy facilitators are concerned with the human rights of children born through cross-border surrogacy, surrogate mothers in developing countries, and intended parents. Commercial surrogacy is a matter that is often cast in the language of human rights. This paper will contribute to an in-depth understanding of the dynamics between intended parents, surrogates, and surrogacy facilitators by adopting a human rights framework to inform data analysis regarding the role of facilitators. The purpose of this research is to inform debate and discussion on law reform related to surrogacy. This paper presented here centers on interviews with surrogacy facilitators in Australia and non-participant observations in Australia to generate thick, empirical data about the fertility industry. The data showed that the process of facilitating surrogacy arrangements had prompted facilitators to form a view on human rights as they applied to their works. Although facilitators claimed that the right of intended parents, surrogate mothers, and children were all taken into consideration, the researcher observed that the commercial surrogacy contracts described by these facilitators favored the interests of intended parents with the baby acting as their unique selling point. The interests and needs of surrogate mothers were not prioritized in the views or actions of facilitators. The result was a commercial transaction that entailed the purchase, through cross-border surrogacy, of a child, as a commodity, by relatively affluent intended parents from disadvantaged surrogate mothers through unfair contracts.

Keywords: cross-border surrogacy, facilitators, human rights, surrogacy

Procedia PDF Downloads 100

Authors: Ihab Al-Mokrani

Abstract:

The Arabic heritage has two types of spoken rhetoric: the first type which al-Jaahiz calls “the rhetoric of the sign,” which means body language, and the rhetoric of silence which is of no less importance than the rhetoric of the sign, the speaker’s appearance and movements, etc. The second type is the spoken performance of utterances which bears written rhetoric arts like metaphor, simile, metonymy, etc. Rationale of the study: First: in spite of the factual existence of rhetorical phenomena in the Arabic heritage, there has been no contemporary study handling the spoken rhetoric in the Arabic heritage. Second: Arabic Civilization is originally a spoken one. Comparing the Arabic culture and civilization, from one side, to the Greek, roman or Pharaonic cultures and civilizations, from the other side, shows that the latter cultures and civilizations started and flourished written while the former started among illiterate people who had no interest in writing until recently. That sort of difference on the part of the Arabic culture and civilization created a rhetoric different from rhetoric in the other cultures and civilizations. Third: the spoken nature of the Arabic civilization influenced the Arabic rhetoric in the sense that specific rhetorical arts have been introduced matching that spoken nature. One of these arts is the art of concision which compensates for the absence of writing’s means of preserving the text. In addition, this interprets why many of the definitions of the Arabic rhetoric were defining rhetoric as the art of concision. Also, this interprets the fact that the literary genres known in the Arabic culture were limited by the available narrow space like poetry, anecdotes, and stories, while the literary genres in the Greek culture were of wide space as epics and drama. This is not of any contrast to the fact that some Arabic poetry would exceed 100 lines of poetry as Arabic poetry was based on the line organic unity, which means that every line could stand alone with a full meaning that is not dependent on the rest of the poem; and that last aspect has never happened in any culture other than the Arabic culture.

Keywords: Arabic rhetoric, spoken rhetoric, Arabic heritage, culture

Procedia PDF Downloads 759

Authors: N. Khursheed, M. Fatima, S. Jamal, A. Raza, S. Rattani, Q. Ahsan, A. Rasheed, M. Jawed

Abstract:

Introduction: Antibiotics are among the commonly prescribed medicines to treat bacterial infections. Their misuse intensifies resistance, and overuse incurs heavy losses to the healthcare system in terms of increased treatment costs and enhanced disease burden. Studies show that 40% of empirically used antibiotics are irrationally utilized. The objective of this study was to evaluate prescribing pattern of antibiotics at six public sector tertiary care hospitals across Pakistan. Methods: A multicenter cross-sectional point prevalence survey (PPS) was conducted in selected wards of six public sector tertiary care hospitals in Pakistan as part of the Clinical Engagement program by Fleming Fund Country Grant Pakistan in collaboration with Indus Hospital & Health Network (IHHN) from February to March 2021, these included Jinnah Postgraduate Medical Center and Dr. Ruth K. M. Pfau Civil Hospital from Karachi, Sheikh Zayed Hospital Lahore, Nishtar Medical University Hospital Multan, Medical Teaching Institute Hayatabad Medical Complex Peshawar, and Provincial Headquarters Hospital Gilgit. WHO PPS methodology was used for data collection (Hospital, ward, and patient level data was collected). Data was entered into the open-source Kobo Collect application and was analyzed using SPSS (version 22.0). Findings: Medical records of 837 in-patients were surveyed, of which the prevalence of antibiotics use was 78.5%. The most commonly prescribed antimicrobial was Ceftriaxone (21.7%) which is categorized in the Watch group of WHO AWaRe Classification, followed by Metronidazole (17.3%), Cefoperazone/Sulbactam (8.4%), Co-Amoxiclav (6.3%) and Piperacillin/Tazobactam (5.9%). The antibiotics were prescribed largely for surgical prophylaxis (36.7%), followed by community-acquired infections (24.7%). One antibiotic was prescribed to 46.7%, two to 39.9%, and three or more to 12.5 %. Two of six (30%) hospitals had functional drug and therapeutic committees, three (50%) had infection prevention and control committees, and one facility had an antibiotic formulary. Conclusion: Findings demonstrate high consumption of broad-spectrum antimicrobials and emphasizes the importance of expanding the antimicrobial stewardship program. Mentoring clinical teams will help to rationalize antimicrobial use.

Keywords: antimicrobial resistance, antimicrobial stewardship, point prevalence survey, antibiotics

Procedia PDF Downloads 91

Authors: Jacqui Robertson

Abstract:

The sustainable governance of groundwater is of the utmost importance in an arid country like Australia. Groundwater has been relied on by our agricultural and pastoral communities since the State was settled by European colonialists. Nevertheless, the rapid establishment of a coal seam gas (CSG) industry in Queensland, Australia, has had extensive impacts on the pre-existing groundwater users. Managed aquifer recharge of important aquifers in Queensland, Australia, using treated coal seam gas produced water has been used to reduce the impacts of CSG development in Queensland Australia. However, the process has not been widely adopted. Negative environmental outcomes are now acknowledged as not only engineering, scientific or technical problems to be solved but also the result of governance failures. An analysis of the regulatory context for aquifer injection using treated CSG water in Queensland, Australia, using Ostrom’s Common Pool Resource (CPR) theory and a ‘heat map’ designed by the author, highlights the importance of governance arrangements. The analysis reveals the costs and benefits for relevant stakeholders of artificial recharge of groundwater resources in this context. The research also reveals missed opportunities to further active management of the aquifer and resolve existing conflicts between users. The research illustrates the importance of strategically and holistically evaluating innovations in technology that impact water resources to reveal incentives that impact resource user behaviors. The paper presents a proactive step that can be adapted to support integrated water resource management and sustainable groundwater development.

Keywords: managed aquifer recharge, groundwater regulation, common-pool resources, integrated water resource management, Australia

Procedia PDF Downloads 215

Authors: Kubra Akbayrak

Abstract:

In parallel with increasing inclusive practice for pupils with vision impairments, the role of specialist teachers who have specialized in the area of vision impairment has dramatically changed in recent years. This study, therefore, aims to provide a holistic perspective towards the distinctive role of specialist teachers of pupils with vision impairments in different educational settings (including mainstream settings, special school settings, etc.) in Turkey and England. Within the scope of the study, semi-structured interviews have been conducted with 17 specialist teachers in Turkey and 14 specialist teachers in England in order to reveal the perception of specialist teachers regarding their roles in different educational settings as well as their perception towards their pre-service training. As this study is a part of an ongoing PhD research, the qualitative data through semi-structured interviews will be analyzed through using Bronfenbrenner’s ecological systems theory as a theoretical framework in order to provide a holistic view regarding the role of specialist teachers particularly in facilitating curriculum access for pupils with vision impairments in England and Turkey. However, the initial findings broadly illustrate that specialist teachers who work in special school settings have different understanding regarding their roles compared to specialist teachers who work in mainstream settings in relation to promoting independence for pupils with vision impairments. The initial findings also imply that specialist teachers in England and Turkey have different perception about their roles in relation to providing specialist advice and guidance for families of pupils. With the completion of the analysis of the study, it is hoped that the findings will provide an insight into the role of specialist teachers in order to provide implication for programmes which prepare specialist teachers of pupils with vision impairments.

Keywords: curriculum access, pupils with vision impairments, specialist teachers, special education

Procedia PDF Downloads 220

Authors: C. F. Jones Couto, L. C. Motlhaolwa, K. Williams

Abstract:

This article explores the re-imagining of physical education teacher education in South African higher education. Utilising student reflections from a physical education practical module, valuable insights into student experiences were obtained about the current physical education pedagogical approaches and potential areas for improvement. The traditional teaching model of physical education is based on the idea of teaching students a variety of sports and physical activities. However, this model has been shown to be ineffective in promoting lifelong physical activity. The modern world demands a more holistic approach to health and wellness. Data was collected using the arts-based collage method in combination with written group reflections from 139 second-year undergraduate physical education students. This study employed thematic analysis methods to gain a comprehensive understanding of the data and extract a broader perspective on the students' experiences. The study aimed to empower student teachers to learn, think, and act creatively within the many educational models that impact their experience, contributing to the ongoing efforts of re-imagining physical education teacher education in South African higher education. This research is significant as the students' valuable insights reflected that they can think and work across disciplines. Sustainable development goals and graduate attributes are important concepts that can contribute to student preparation. Using a multi-model educational approach based on the cultural-historical theory, higher education institutions can help develop graduate attributes that will prepare students for success in the workplace and life.

Keywords: holistic education, graduate attributes, physical education, teacher education, student experiences, sustainable development goals

Procedia PDF Downloads 59

Authors: Jules Selles

Abstract:

The Atlantic and Mediterranean bluefin tuna fishery have been considered as the archetype of an overfished and mismanaged fishery. This crisis has demonstrated the role of public awareness and the importance of the interactions between science and management about scientific uncertainties. This work aims at investigating the policy making process associated with a regional fisheries management organization. We propose a contextualized computer-based experimental approach, in order to explore the effects of key factors on the cooperation process in a complex straddling stock management setting. Namely, we analyze the effects of the introduction of a socio-economic tipping point and the uncertainty surrounding the estimation of the resource level. Our approach is based on a Gordon-Schaefer bio-economic model which explicitly represents the decision making process. Each participant plays the role of a stakeholder of ICCAT and represents a coalition of fishing nations involved in the fishery and decide unilaterally a harvest policy for the coming year. The context of the experiment induces the incentives for exploitation and collaboration to achieve common sustainable harvest plans at the Atlantic bluefin tuna stock scale. Our rigorous framework allows testing how stakeholders who plan the exploitation of a fish stock (a common pool resource) respond to two kinds of effects: i) the inclusion of a drastic shift in the management constraints (beyond a socio-economic tipping point) and ii) an increasing uncertainty in the scientific estimation of the resource level.

Keywords: economic experiment, fisheries management, game theory, policy making, Atlantic Bluefin tuna

Procedia PDF Downloads 236

Authors: Celine Jaspers

Abstract:

The Belgian legal system is slowly evolving to mandatory mediation to promote ADR. One of the reasons for this evolution is the lack of use of alternative methods in relation to their possible benefits. Especially in divorce cases, ADR can play a beneficial role in resolving disputes, since the emotional component is very much present. When children are involved, a solution provided by the parent may be more adapted to the child’s best interest than a court order. In the first part, the lack of use of voluntary ADR and the evolution toward mandatory ADR in Belgium will be indicated by sources of legislation, jurisprudence and social-scientific sources, with special attention to divorce cases. One of the reasons is lack of knowledge on ADR, despite the continuing efforts of the Belgian legislator to promote ADR. One of the last acts of ADR-promotion, was the implementation of an Act in 2018 which gives the judge the possibility to refer parties to mediation if at least one party wants to during the judicial procedure. This referral is subject to some conditions. The parties will be sent to a private mediator, recognized by the Federal Mediation Commission, to try to resolve their conflict. This means that at least one party can be mandated to try mediation (indicated as “semi-mandatory mediation”). The main goal is to establish the factors and elements that Belgium has to take into account in their further development of mandatory ADR, with consideration of the human rights perspective and the EU perspective. Furthermore it is also essential to detect some dangerous pitfalls other systems have encountered with their process design. Therefore, the second part, the comparative component, will discuss the existing framework in California, USA to establish the necessary elements, possible pitfalls and considerations the Belgian legislator can take into account when further developing the framework of mandatory ADR. The contrasting and functional method will be used to create key elements and possible pitfalls, to help Belgium improve its existing framework. The existing mandatory system in California has been in place since 1981 and is still up and running, and can thus provide valuable lessons and considerations for the Belgian system. Thirdly, the key elements from a human rights perspective and from a European Union perspective (e.g. the right to access to a judge, the right to privacy) will be discussed too, since the basic human rights and European legislation and jurisprudence play a significant part in Belgian legislation as well. The main sources for this part will be the international and European treaties, legislation, jurisprudence and soft law. In the last and concluding part, the paper will list the most important elements of a mandatory ADR-system design with special attention to the dangers of these elements (e.g. to include or exclude domestic violence cases in the mandatory ADR-framework and the consequences thereof), and with special attention for the necessary the international and European rights, prohibitions and guidelines.

Keywords: Belgium, divorce, framework, mandatory ADR

Procedia PDF Downloads 132

Authors: Kai-Jui Kou, Tzu-Ling Shen, Ying-Fang Wang

Abstract:

The objectives of the present study are to characterize nanoparticles generated from the different working type in 3D printing room and the stack flue during 3D printing process. The studied laboratory (10.5 m× 7.2 m × 3.2 m) with a ventilation rate of 500 m³/H is installed a 3D metal printing machine. Direct-reading instrument of a scanning mobility particle sizer (SMPS, Model 3082, TSI Inc., St. Paul, MN, USA) was used to conduct static sampling for nanoparticle number concentration and particle size distribution measurements. The SMPS obtained particle number concentration at every 3 minutes, the diameter of the SMPS ranged from 11~372 nm when the aerosol and sheath flow rates were set at 0.6 and 6 L/min, respectively. The concentrations of background, printing process, clearing operation, and screening operation were performed in the laboratory. On the other hand, we also conducted nanoparticle measurement on the 3D printing machine's stack flue to understand its emission characteristics. Results show that the nanoparticles emitted from the different operation process were the same distribution in the form of the uni-modal with number median diameter (NMD) as approximately 28.3 nm to 29.6 nm. The number concentrations of nanoparticles were 2.55×10³ count/cm³ in laboratory background, 2.19×10³ count/cm³ during printing process, 2.29×10³ count/cm³ during clearing process, 3.05×10³ count/cm³ during screening process, 2.69×10³ count/cm³ in laboratory background after printing process, and 6.75×10³ outside laboratory, respectively. We found that there are no emission nanoparticles during the printing process. However, the number concentration of stack flue nanoparticles in the ongoing print is 1.13×10⁶ count/cm³, and that of the non-printing is 1.63×10⁴ count/cm³, with a NMD of 458 nm and 29.4 nm, respectively. It can be confirmed that the measured particle size belongs to easily penetrate the filter in theory during the printing process, even though the 3D printer has a high-efficiency filtration device. Therefore, it is recommended that the stack flue of the 3D printer would be equipped with an appropriate dust collection device to prevent the operators from exposing these hazardous particles.

Keywords: nanoparticle, particle emission, 3D printing, number concentration

Procedia PDF Downloads 164