Search results for: code-switching contact linguistics

Authors: Xiaodong Xu, Dan Zhao, Xiujuan Chang, Chunming Li, Huiyun Zhou, Xin Li, Qiang Shi, Shifang Luan, Jinghua Yin

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Polypropylene (PP) is one of the most commonly used plastics because of its low density, outstanding mechanical properties, and low cost. However, its drawbacks such as low surface energy, poor dyeability, lack of chemical functionalities, and poor compatibility with polar polymers and inorganic materials, have restricted the application of PP. To expand its application in biomedical materials, functionalization is considered to be the most effective way. In this study, PP was functionalized with a chiral monomer, (S)-1-acryloylpyrrolidine-2-carboxylic acid ((S)-APCA), by free-radical grafting in the solid phase. The grafting degree of PP-g-APCA was determined by chemical titration method, and the chemical structure of functionalized PP was characterized by FTIR spectroscopy, which confirmed that the chiral monomer (S)-APCA was successfully grafted onto PP. Static water contact angle results suggested that the surface hydrophilicity of PP was significantly improved by solid phase grafting and assistance of surface water treatment. Protein adsorption and platelet adhesion results showed that hemocompatibility of PP was greatly improved by grafting the chiral monomer.

Keywords: functionalization, polypropylene, chiral monomer, hemocompatibility

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Authors: Jesús A. Pérez, Sam Coppieters, Dimitri Debruyne

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In the past decade, the use of digital image correlation (DIC) techniques has increased significantly in the area of experimental mechanics, especially for materials behavior characterization. This non-contact tool enables full field displacement and strain measurements over a complete region of interest. The DIC algorithm requires a random contrast pattern on the surface of the specimen in order to perform properly. To create this pattern, the specimen is usually first coated using a white matt paint. Next, a black random speckle pattern is applied using any suitable method. If the applied paint coating is too thick, its top surface may not be able to exactly follow the deformation of the specimen, and consequently, the strain measurement might be underestimated. In the present article, a study of the influence of the paint thickness on the strain underestimation is performed for different strain levels. The results are then compared to typical paint coating thicknesses applied by experienced DIC users. A slight strain underestimation was observed for paint coatings thicker than about 30μm. On the other hand, this value was found to be uncommonly high compared to coating thicknesses applied by DIC users.

Keywords: digital image correlation, paint coating thickness, strain

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Authors: Raef Cherif, Houssine Bakkali, Wafaa El Khatiri, Yacine Yaddaden

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The analysis of how vibrations are transmitted between components is required in many engineering applications. Transfer path analysis (TPA) has been a valuable engineering tool for solving Noise, Vibration, and Harshness (NVH problems using sub-structuring applications. The most challenging part of a TPA analysis is estimating the equivalent forces at the contact points between the active and the passive side. Component TPA in situ Method calculates these forces by inverting the frequency response functions (FRFs) measured at the passive subsystem, relating the motion at indicator points to forces at the interface. However, matrix inversion could pose problems due to the ill-conditioning of the matrices leading to inaccurate results. This paper establishes a TPA model for an academic system consisting of two plates linked by four springs. A numerical study has been performed to improve the interface forces identification. Several parameters are studied and discussed, such as the singular value rejection and the number and position of indicator points chosen and used in the inversion matrix.

Keywords: transfer path analysis, matrix inverse method, indicator points, SVD decomposition

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Authors: Eliziane Fernanda Navarro, Aparecida Eleonora Sitta

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Child of the Dark is the work of the Brazilian author Carolina Maria de Jesus, published at the first time by Ática and Francisco Alves in 1960. It is, mostly, a story of lack of rights. It lacks to men who live in the slums what is essential in order to take advantage of the privilege of rationality to develop themselves as civilized humans. It is, therefore, in the withholding of the basic rights that inequality finds space to build itself to be the main misery on Earth. Antonio Candido, a Brazilian sociologist claims that it is the right to literature has the ability to humanize men, once the aptitude to create fiction and fable is essential to the social balance. Hence, for the forming role that literature holds, it must be thought as the number of rights that assure human dignity, such as housing, education, health, freedom, etc. When talking about her routine, Carolina puts in evidence something that has great influence over the formation of human beings, contributing to the way they live: the slum. Even though it happens in a distinct way and using her own linguistics variation, Carolina writes about something that will only be discussed later on Brazil’s Cities Statute and Erminia Maricato: the right to the city, and how the slums are, although inserted in the city, an attachment, an illegal city, a dismissing room. It interests ourselves, for that matter, in this work, to analyse how the deprivation of the rights to the city and literature, detailed in Carolina’s journal, conditions human beings to a life where the instincts overcome the social values.

Keywords: Child of the Dark, slum, literature, architecture and urbanism, fundamental rights, Brazil

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Authors: Aline Giardin, Maria Rosa Chitolina, Maria Catarina Zanini

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In this paper, we analyze the conceptions of high school students about mental health issues, and discuss the creation of mental basic health programs in schools. We base our findings in a quantitative survey carried out by us with 156 high school students of CTISM (Colégio Técnico Industrial de Santa Maria) school, located in Santa Maria city, Brazil. We have found that: (a) 28 students relate the subject ‘mental health’ with psychiatric hospitals and lunatic asylums; (b) 28 students have relatives affected by mental diseases; (c) 76 students believe that mental patients, if treated, can live a healthy life; (d) depression, schizophrenia and bipolar disorder are the most cited diseases; (e) 84 students have contact with mental patients, but know nothing about the disease; (f) 123 students have never been instructed about mental diseases while in the school; and (g) 135 students think that a mental health program would be important in the school. We argue that these numbers reflect a vision of mental health that can be related to the reductionist education still present in schools and to the lack of integration between health professionals, sciences teachers, and students. Furthermore, this vision can also be related to a stigmatization process, which interferes with the interactions and with the representations regarding mental disorders and mental patients in society.

Keywords: mental health, schools, mental illness, conception

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Authors: Ana Sofia Saldanha

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The globalization is changing the translation world day after day, year after year. The need to know more about new technologies, clients, companies and social networks is becoming more and more demanding and competitive. The recently graduated translators usually do not know where to go, what to do or even who to contact to start their careers in translation. It is well known that there are innumerous webinars, books, blogs, webpages and even Facebook pages indicating what to do, what not to do, rates, how your CV should look like, etc. but are these pieces of advice of real translators? Translators, who work daily with clients, who understand their demands, requests, questions? As far as today`s trends, the answer is NO. Most of these pieces of advice are just theoretical and far away from the real translation world. Therefore, mentoring is becoming a very important tool to help and guide new translators starting their career. An effective and well-oriented mentoring is a powerful way to orient these translators on how to create their CVs, where to send CVs, how to approach clients, how to answer emails and how to negotiate rates in an efficient way. Mentoring is crucial when properly delivered by professional and experienced translators, to help developing careers. The advice and orientation sessions are almost a 'weapon' to destroy the barriers created by opinions, by influences or even by universities. This new trend is the future path of new translators and is the future of the translation industry and professionals, however minds and spirits need to be opened and engaged in this new way of developing skills.

Keywords: mentoring, translation, translators, orientation, professional path

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Authors: Sanjoy Barua Chowdhury

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This research is an attempt to examine psychological aspect of the Buddha’s most cardinal and fundamental doctrine of Dependent Origination (paṭiccasamuppāda) along with drawing out a clear picture of the constituents from the law of causation and analyzes the mental states and motivational factors behind each constituent among twelvefold links. Meticulous research into the doctrine of Dependent Origination reveals how the main links from the doctrine of dependent origination provide a framework for psychological analysis through volitional formation (saṅkhāra), consciousness (viññāna), mentality and materiality (nāma-rūpa), contact (phassa), feeling (vedanā), craving (tanhā) and clinging (upādāna). This paper further illustrates the notion of perception (saññā) which can be found in the function of volitional formation (saṅkhāra) - a contributing factor, according to modern psychology, in the role of understanding human (puggala) motivation. The psychological analysis of dependent origination expounds the concept of personality highlighting present existence through the inter-relationship of the five faculties (pañcaupadānakkhandhā), viz., form (rūpa), feeling (vedanā), perception (saññā), volitional formation (saṅkhārā) and consciousness (viññāṇa).

Keywords: dependent origination, perception, motivational factors, feelings

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Authors: John Rosswell Cummings III

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This research examines the discourse ancient Maya ritual practice manifest and maintained through language in a contemporary society as led by a daykeeper— a Maya spiritual leader— with the objective of discovering if the Maya Calendar has an influence on worldview. Through an ethnography of communication and discursive analysis framework, this research examines the discourse of and around the Maya calendar through original research. Data collected includes the ceremonial performance of the Tzolkin ritual, a ritual that takes place every 13 days to ceremonially welcome one of the 20 Universal Forces. During the ceremony, participants supplicate, sacrifice, and venerate. This ritual, based off the Tzolkin cycle in the Mayan Calendar, contains strong, culture-binding ideologies. This research performs a close analysis of the 20 energies of the Tzolkin and their glyphs so as to gain a better understanding of current ideologies in Maya communities. Through a linguistic relativity frame of reference, including both the strong and weak versions, the 20 Universal Forces are shown to influence ways of life. This research argues that it is not just the native language, but the discourses native to the community as held through the calendar, influence thought and have the potential to offer an alternate worldview, thus shaping the cultural narrative which in return influences identity of the community. Research of this kind, on calendric systems and linguistic relativity, has the power to make great discoveries about the societies of the world and their worldviews.

Keywords: anthropological linguistics, discourse analysis, cultural studies, sociolinguistics

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Authors: M. Hadavi, Z. Hashemi

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Learning strategies play an important role in the development of language skills. Vocabulary learning strategies as the backbone of these strategies have become a major part of English language teaching. This study is a comparative analysis of Vocabulary Learning Strategies (VLS) use and preference among freshmen and senior EFL medical sciences students with different fields of study. 449 students (236 freshman and 213 seniors) participated in the study. 64.6% were female and 35.4% were male. The instrument utilized in this research was a questionnaire consisting of 41 items related to the students’ approach to vocabulary learning. The items were classified under eight sections as dictionary strategies, guessing strategies, study preferences, memory strategies, autonomy, note- taking strategies, selective attention, and social strategies. The participants were asked to answer each item with a 5-point Likert-style frequency scale as follows:1) I never or almost never do this, 2) I don’t usually do this, 3) I sometimes do this, 4) I usually do this, and 5)I always or almost always do this. The results indicated that freshmen students and particularly surgical technology students used more strategies compared to the seniors. Overall guessing and dictionary strategies were the most frequently used strategies among all the learners (p=0/000). The mean and standard deviation of using VLS in the students who had no previous history of participating in the private English language classes was less than the students who had attended these type of classes (p=0/000). Female students tended to use social and study preference strategies whereas male students used mostly guessing and dictionary strategies. It can be concluded that the senior students under instruction from the university have learned to rely on themselves and choose the autonomous strategies more, while freshmen students use more strategies that are related to the study preferences.

Keywords: vocabulary leaning strategies, medical sciences, students, linguistics

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Authors: Chandeera Gunawardena

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The present research analyzes the pronunciation errors encountered by thirty Sinhala speaking learners of French on the assumption that the pronunciation errors were systematic and they reflect the interference of the native language of the learners. The thirty participants were selected using random sampling method. By the time of the study, the subjects were studying French as a foreign language for their Bachelor of Arts Degree at University of Kelaniya, Sri Lanka. The participants were from a homogenous linguistics background. All participants speak the same native language (Sinhala) thus they had completed their secondary education in Sinhala medium and during which they had also learnt French as a foreign language. A battery operated audio tape recorder and a 120-minute blank cassettes were used for recording. A list comprised of 60 words representing all French phonemes was used to diagnose pronunciation difficulties. Before the recording process commenced, the subjects were requested to familiarize themselves with the words through reading them several times. The recording was conducted individually in a quiet classroom and each recording approximately took fifteen minutes. Each subject was required to read at a normal speed. After the completion of recording, the recordings were replayed to identify common errors which were immediately transcribed using the International Phonetic Alphabet. Results show that Sinhala speaking learners face problems with French nasal vowels and French initial consonants clusters. The learners also exhibit errors which occur because of their second language (English) interference.

Keywords: error analysis, pronunciation difficulties, pronunciation errors, Sinhala speaking learners of French

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Authors: Natália C. C. Lobato, Ângela M. Ferreira, Marcelo B. Mansur

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In solvent extraction operations, large sedimentation areas in the mixer-settler are required when the disengagement of the aqueous and the organic phases is slow and/or difficult. The use of a magnetic organic liquid (also known as ferrofluid), consisting of magnetite nanoparticles coated by oleic acid dispersed in the organic diluent, has proven successful to speed up phase disengagement. The method, however, has never been used industrially; therefore, the aim of this study is to raise its main limitations. Tests were carried out using a ferrofluid containing 30 g/l of magnetite dissolved in commercial aliphatic kerosene Exxsol D80. The efficiency of cobalt extraction ([Co] = 1 g/l) with 10% v/v Cyanex 272 (bis-2,4,4-trimethylpentyl phosphinic acid) at changing pH of the aqueous phase (2 to 7) was found unaffected in the conditions studied. However, the chemical resistance of the ferrofluid in contact with deionized water at changing acidity (from 10-7 to 2 mol/l) revealed that the nanoparticles are not resistant when contacted to aqueous solutions with a pH ≤ 2. Such result represents a serious limitation to the applicability of the method mainly to hydrometallurgical systems because solvent extraction operations are normally done in acid conditions, therefore more effective strategies to coat the particles are required.

Keywords: magnetic solvent extraction, oleic acid, magnetite nanoparticles, cyanex 272

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Authors: P. Kumar, D. Eisenhauer, M. M. K. Yousef, Q. Shi, A. S. G. Khalil, M. R. Saber, C. Becker, T. Pullerits, K. J. Karki

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In impedance spectroscopy (IS) the response of a photo-active device is analysed as a function of ac bias. It is widely applied in a broad class of material systems and devices. It gives access to fundamental mechanisms of operation of solar cells. We have implemented a method of IS where we modulate the light instead of the bias. This scheme allows us to analyze not only carrier dynamics but also impedance of device locally. Here, using this scheme, we have measured the frequency-dependent photocurrent response of the thin-film planar and nano-textured Si solar cells using this method. Photocurrent response is measured in range of 50 Hz to 50 kHz. Bode and Nyquist plots are used to determine characteristic lifetime of both the cells. Interestingly, the carrier lifetime of both planar and nano-textured solar cells depend on back and front contact positions. This is due to either heterogeneity of device or contacts are not optimized. The estimated average lifetime is found to be shorter for the nano-textured cell, which could be due to the influence of the textured interface on the carrier relaxation dynamics.

Keywords: carrier lifetime, impedance, nano-textured, photocurrent

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Authors: Mohammad Sharifi Bohlouli

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Turkish language with many dialects is native or official language of great number of people all around the world. The Qashqaie dialect of Turkish language is spoken by the Qashqaie tribe mostly scattered in the southern part of Iran. This paper aims at analyzing the tense system of this dialect to detect the type and number of tense and aspects available to its speakers. To collect a reliable data, a group of 50 old native speakers were randomly chosen as the informants and different techniques such as; Shuy et al interviews, selective listening ,and eavesdropping were used. The results of data analysis showed that the tense system in the Qashqaie dialect of Turkish language includes 3 absolute tenses , 6 aspectual , and 2 subjunctive ones. The interesting part of the study is that Qashqaie dialect enables its speakers to make a kind of aspectual opposition through verb structure which seems to be almost impossible through verb forms in any other nonturkish languages. For example in the following examples sentences 1 &2 and 3&4 have the same translation In English although they are different in both meaning and structure. 1. Ali ensha yazirdi. 2. Ali ensha yazirmush. (Ali was writing a composition.) 3. Ali yadmishdi. 4. Ali yadmishimish. ( Ali had slept.) The changes in the verb structure in Qashqaie dialect enables its speakers to say that whether the doer of the action remembers the process of doing the action or not. So, it presents a new aspectual opposition as Observed /nonobserved. The research findings reveal many other regularities and linguistic features that can be useful for linguists interested in Turkish in general and for those interested in tense and aspect and also they can be helpful for different pedagogical purposes including teaching and translating.

Keywords: qashqaie dialect, tense, aspect, linguistics, Turkish Language

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Authors: Clement Ndoricimpa

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The expression of stance is highly expected in writing at tertiary level. Through a selection of linguistic and rhetorical elements, writers express commitment, critical distance and build a critically discerning reader in texts. Despite many studies on patterns of stance in students’ academic writing, little may not be known about how English as a Foreign Language students learns to build a critically discerning reader in their texts. Therefore, this study examines patterns of stance in essays written by students majoring in business administration at English-medium University in Burundi as part of classroom assignments. It draws on systemic functional linguistics to analyze qualitatively and quantitatively the data. The quantitative analysis is used to identify the differences in frequency of stance patterns in the essays. The results show a significant difference in the use of boosters by lower- and upper-level students. Lower-level students’ writing contains more boosters and many idiosyncratic sentence structures than do upper-level students’ writing, and upper-level students’ essays contain more hedging and few grammatical mistakes than do lower-level students’ essays. No significant difference in the use of attitude markers and concessive and contrastive expressions. Students in lower- and upper-level do not use attitude markers and disclaimer markers appropriately and accurately. These findings suggest that students should be taught the use of stance patterns in academic writing.

Keywords: academic writing, metadiscourse, stance, student corpora

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Authors: Sevil Kaynar Turkoglu, Jinde Zhang, Jo Ann Ratto, Hanna Dodiuk, Samuel Kenig, Joey Mead

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Superhydrophilic, crack-free thin film coatings based on silica nanoparticles were fabricated by dip-coating method. Both thermodynamic and dynamic effects on the wetting properties of the thin films were investigated by modifying the coating formulation via changing the particle-to-binder ratio and weight % of silica in solution. The formulated coatings were characterized by a number of analyses. Water contact angle (WCA) measurements were conducted for all coatings to characterize the surface wetting properties. Scanning electron microscope (SEM) images were taken to examine the morphology of the coating surface. Atomic force microscopy (AFM) analysis was done to study surface topography. The presence of hydrophilic functional groups and nano-scale roughness were found to be responsible for the superhydrophilic behavior of the films. In addition, surface chemistry, compared to surface roughness, was found to be a primary factor affecting the wetting properties of the thin film coatings.

Keywords: poly (acrylic acid), silica nanoparticles, superhydrophilic coatings, surface wetting

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Authors: Paras Adlakha

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Today the major threat to our existing and future satellites is space debris; the collision of bodies like defunct satellites with any other objects in space, including the new age ASAT (anti-satellite) weaponry system, are the main causes of the increasing amount of space debris every year. After analyzing the current situation of space debris, low earth orbit is found to be having a large density of debris as compared to any other orbit range; that's why it is selected as the target orbit for space debris removal mission. In this paper, the complete data of 24000 debris is studied based on size, altitude, inclination, mass, number of existing satellites threaten by each debris from which the rocket bodies are the type of wreckage found to be most suited for removal. The optimal method of active debris removal using a robotic arm for capturing the body to attach a de-orbit kit is used to move the debris from its orbit without making the actual contact of servicer with the debris to reduce the further the threat of collision with defunct material. The major factors which are brought into consideration while designing the concept of debris removal are tumbling, removal of debris under a low-cost mission and decreasing the factor of collisions during the mission.

Keywords: de-orbit, debris, servicer, satellite, space junk

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Authors: Noah Brandon

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Grammatical gender can create a restrictive roadblock for the usage of gender-inclusive language. This research describes grammatical gender structures used in English, Dutch, and German and considers how these structures restrict the implementation of gender inclusivity in spoken and written discourse. This restriction is measured by the frequency with which gender-inclusive & generic masculine forms are used and by the morphosyntactic complexity of the gender-inclusive forms available in these languages. These languages form a continuum of grammatical gender structures, with English having the least articulated structures and German having the most. This leads to a comparative analysis intended to establish a correlation between the complexity of gender structure and the difficulty of using gender-inclusive forms. English, on one side of the continuum, maintains only remnants of a formal grammatical gender system and imposes the fewest restrictions on the creation of neo-pronouns and the use of gender-inclusive alternatives to gendered agentive nouns. Next, the Dutch have a functionally two-gender system with less freedom using gender-neutral forms. Lastly, German, on the other end, has a three-gender system requiring a plethora of morphosyntactic and orthographic alternatives to avoid using generic masculine. The paper argues that the complexity of grammatical gender structures correlates with hindered use of gender-inclusive forms. Going forward, efforts will focus on gathering further data on the usage of gender-inclusive and generic masculine forms within these languages. The end goal of this research is to establish a definitive objective correlation between grammatical gender complexity and impediments in expressing socially constructed gender.

Keywords: sociolinguistics, language and gender, gender, Germanic linguistics, grammatical gender, German, Dutch, English

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Authors: Kornkanok Noulta, Pornsri Pakeyangkoon, Stephen T. Dubas, Pomthong Malakul, Manit Nithithanakul

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In recent years, interest in the development of material for tissue engineering application has increased considerably. Poly(High Internal Phase Emulsion) (PolyHIPE) foam is a material that is good candidate for used in tissue engineering application due to its 3D structure and highly porous with interconnected pore. The PolyHIPE was prepared from poly (styrene/ethylene glycol dimethacrylate) through high internal phase emulsion polymerization technique and loaded with hydroxyapatite (HA) to improve biocompatibility. To further increase hydrophilicity of the obtained polyHIPE, layer-by-layer polyelectrolyte multilayers (PEM) technique was used. A surface property of polyHIPE was characterized by contact angle measurement. Morphology and pore size was observed by scanning electron microscope (SEM). The cell viability was revealed by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay technique.

Keywords: polyelectrolyte multilayer thin film, high internal phase emulsion, polyhipe foam, scaffold, tissue engineering

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Authors: Maureen Lilian Klos

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In this paper, the notion of autonomy in language teaching and learning is explored with a view to designing particular subject-specific academic literacy at higher education level, for mostly English second or third language learners at the Nelson Mandela University, Port Elizabeth, South Africa. These courses that are contextualized in subject-specific fields studied by students in Arts, Education and Social Science Faculties aim to facilitate learners in the manipulation of cognitively demanding academic texts. However, classroom contact time for these courses is limited to one ninety sessions per week. Thus, learners need to be autonomously responsible for developing their own skills when manipulating and negotiating appropriate academic textual conventions. Thus, a model was designed to allow for gradual learner independence in language learning skills. Learners experience of the model was investigated using the Phenomenological Research Approach. Data in the form of individual written reflections and transcripts of unstructured group interviews were analyzed for themes and sub-themes. These findings are discussed in the article with a view to addressing the practical concerns of the learners in this case study.

Keywords: academic literacies, autonomy, language learning and teaching, subject-specific language

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Authors: Chuanxiang Cheng, Tiantian Min, Jin Yue

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Antimicrobial active packaging enables extensive biological effects to improve food safety. However, the efficacy of antimicrobial packaging hinges on factors including the diffusion rate of the active agent toward the food surface, the initial content in the antimicrobial agent, and the targeted food shelf life. Among the possibilities of antimicrobial packaging design, an interesting approach involves the incorporation of volatile antimicrobial agents into the packaging material. In this case, the necessity for direct contact between the active packaging material and the food surface is mitigated, as the antimicrobial agent exerts its action through the packaging headspace atmosphere towards the food surface. However, it still remains difficult to achieve controlled and precise release of bioactive compounds to the specific target location with required quantity in food packaging applications. Remarkably, the development of stimuli-responsive materials for electrospinning has introduced the possibility of achieving controlled release of active agents under specific conditions, thereby yielding enduring biological effects. Relative humidity (RH) for the storage of food categories such as meat and aquatic products typically exceeds 90%. Consequently, high RH can be used as an abiotic trigger for the release of active agents to prevent microbial growth. Hence, a novel RH - responsive polyvinyl alcohol/chitosan (PVA/CS) composite nanofibrous film incorporated with 4-terpineol/β-cyclodextrin inclusion complexes (4-TA@β-CD ICs) was engineered by electrospinning that can be deposited as a functional packaging materials. The characterization results showed the thermal stability of the films was enhanced after the incorporation due to the hydrogen bonds between ICs and polymers. Remarkably, the 4 wt% 4-TA@β-CD ICs/PVA/CS film exhibited enhanced crystallinity, moderate hydrophilic (Water contact angle of 81.53°), light barrier property (Transparency of 1.96%) and water resistance (Water vapor permeability of 3.17 g mm/m2 h kPa). Moreover, this film also showed optimized mechanical performance with a Young’s modulus of 11.33 MPa, a tensile strength of 19.99 MPa and an elongation at break of 4.44 %. Notably, the antioxidant and antibacterial properties of this packaging material were significantly improved. The film demonstrated the half-inhibitory concentrations (IC50) values of 87.74% and 85.11% for scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonic) (ABTS) free radicals, respectively, in addition to an inhibition efficiency of 65% against Shewanella putrefaciens, the characteristic bacteria in aquatic products. Most importantly, the film achieved controlled release of 4-TA under high 98% RH by inducing the plasticization of polymers caused by water molecules, swelling of polymer chains, and destruction of hydrogen bonds within the cyclodextrin inclusion complex. Consequently, low relative humidity is suitable for the preservation of nanofibrous film, while high humidity conditions typical in fresh food packaging environments effectively stimulated the release of active compounds in the film. This film with a long-term antimicrobial effect successfully extended the shelf life of Litopenaeus vannamei shrimp to 7 days at 4 °C. This attractive design could pave the way for the development of new food packaging materials.

Keywords: controlled release, electrospinning, nanofibrous film, relative humidity–responsive, shrimp preservation

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Authors: I. Sterbova, E. Oberhofnerova, M. Panek, M. Pavelek

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With growing popularity, wood of European larch (Larix decidua, Mill.) is being more often applied into the exterior, usually as facade elements, also without surface treatment. The aim of this work was to compare two laboratory tests of artificial accelerated weathering of wood with two ways of natural weathering in the exterior. To assess changes in selected surface characteristics of larch wood, accelerated weathering methods in the Xenotest and UV chamber were used, both in combination with temperature cycling, for 6 weeks. They were compared with natural weathering results at exposition under 45° and 90° in the exterior for 12 months. The changes of colour, gloss, contact angle of water and also changes in visual characteristics were evaluated. The results of wood surfaces changes after 6 weeks of accelerated weathering in Xenotest are closer to 12 months of natural weathering in the exterior at an angle of 90° compared to the UV chamber testing. The results, especially the colour changes, of the samples exposed at an angle of 45° in the exterior were significantly different. Testing in Xenotest more closely simulates the weathering of façade elements in the exterior compared to the UV chamber testing.

Keywords: larch wood, wooden facade, wood accelerated weathering, weathering methods

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Authors: Nilesh Pancholi, Mangal Bhatt

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This paper highlights comparative results of traditional FMECA and multi-factor decision-making approach based on “Technique for Order Preference by Similarity to Ideal Solution (TOPSIS)” for aluminum wire rolling mill plant. The suggested study is carried out to overcome the limitations of FMECA by assigning the scores against each failure modes in crisp values to evaluate the criticalities of the failure modes without uncertainty. The primary findings of the paper are that sudden impact on the rolls seems to be most critical failure cause and high contact stresses due to rolling & sliding action of mesh to be least critical failure cause. It is suggested to modify the current control practices with proper maintenance strategy based on achieved maintainability criticality index (MCI). The outcome of the study will be helpful in deriving optimized maintenance plan to maximize the performance of continuous process industry.

Keywords: reliability, maintenance, FMECA, TOPSIS, process industry

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Authors: Hyeong-Gyu Park, Hak-Gon Noh, Beom-Soo Kang, Jeong Kim

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Electromagnetic forming (EMF) process is one of a high-speed forming process, which uses an electromagnetic body (Lorentz) force to deform work-piece. Advantages of EMF are summarized as improvement of formability, reduction in wrinkling, non-contact forming. In this study, the spiral coil is considered to evaluate formability in terms of pressure distribution of the forming process. It also is represented forming results of numerical analysis using ANSYS code. In the numerical simulation, RLC circuit coupled with spiral coil was made to consider the design parameters such as system input current and electromagnetic force. The simulation results show that even though input peak currents level are same level in each case, forming condition is certainly different because of frequency of input current and magnitude of current density and magnetic flux density. Finally, the simulation results appear that electromagnetic forming force apparently affected by input current frequency which determines magnitude of current density and magnetic flux density.

Keywords: electromagnetic forming, high-speed forming, RLC circuit, Lorentz force

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Authors: S. A. M. Sabrina, Gouget Lammel, Anne Chantal, Chazalviel, Jean Noël, Ozanam François, Etcheberry Arnaud, Tighlit Fatma Zohra, B. Samia, Gabouze Noureddine

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The elaboration and characterization of hybrid nano materials give rise to considerable interest due to the new properties that arising. They are considered as an important category of new materials having innovative characteristics by combining the specific intrinsic properties of inorganic compounds (semiconductors) with the grafted organic species. This open the way to improved properties and spectacular applications in various and important fields, especially in the environment. In this work, nano materials based-semiconductors were elaborated by chemical route. The obtained surfaces were grafted with organic functional groups. The functionalization process was optimized in order to confer to the hybrid nano material a good stability as well as the right properties required for the subsequent applications. Different characterization techniques were used to investigate the resulting nano structures, such as SEM, UV-Visible, FTIR, Contact angle and electro chemical measurements. Finally, applications were envisaged in environmental area. The elaborated nano structures were tested for the detection and the elimination of pollutants.

Keywords: hybrid materials, porous silicon, peptide, metal detection

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Authors: Hesham Moustafa, Ahmed M. Youssef

Abstract:

The demand for green packagingin the food field has been gained increasing attention in recent decades because of its degradability and safely. Thus, this study revealed that the by-product bagasse papers (BPs) derived from sugarcane waste can be decorated with a thin layer of polystyrene (PS) nanocomposites using the spreading approach.Three variable concentrations of TiO2 nanoparticles (i.e. 0.5, 1.0, 1.5 wt.%) were used to fabricate PS nanocomposites. The morphology of coated BP-PS biofilms was examined by X-ray diffraction, Fourier transferred Infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Moreover, other measurements such as mechanical, thermal stability, flammability, wettability by the contact angle, water vapor, and gas barrier properties were carried out on the fabricated BP-PS biofilms. Most outcomes showed that the major properties were enhanced when the PS nanocomposites were implemented. The use of 1.5 wt.% TiO2 in PS nanocomposite for coated BP-PS biofilm increased the tensile stress by ~ 217 % compared to uncoated BP film. Furthermore, the rate of burning for BP-PS-1.5% film was reduced to ~ 33 mm/min because of the crystallinity of PS and the barrier effect provided by TiO₂ NPs. These coated sheets provide a promising candidate for use in advanced packaging applications.

Keywords: bagasse paper, polystyrene nanocomposites, TiO2 nanoparticles, active packaging, mechanical properties, flammability

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Authors: Chih-Chia Lin, Ching-Ying Huang, Cheng-Hong Liu, Wen-Lin Wang

Abstract:

A complete fuel cell stack comprises several single cells with end plates, bipolar plates, gaskets and membrane electrode assembly (MEA) components. Electrons generated from cells are conducted through bipolar plates. The amount of cells' components increases as the stack voltage increases, complicating the fuel cell assembly process and mass production. Stack assembly error influence cell performance. PEM fuel cell stack importing laser welding technique could eliminate transverse deformation between bipolar plates to promote stress uniformity of cell components as bipolar plates and MEA. Simultaneously, bipolar plates were melted together using laser welding to decrease interface resistance. A series of experiments as through-plan and in-plan resistance measurement test was conducted to observe the laser welding effect. The result showed that the through-plane resistance with laser welding was a drop of 97.5-97.6% when the contact pressure was about 1MPa to 3 MPa, and the in-plane resistance was not significantly different for laser welding.

Keywords: PEM fuel cell, laser welding, through-plan, in-plan, resistance

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Authors: Eman H. El-Gamal, Mai E. Khedr, Randa Ghonim, Mohamed Rashad

Abstract:

In the past few years, biochar - a highly carbon-rich material produced from agro-wastes by pyrolysis process - was used as an effective adsorbent for heavy metals removal from polluted water. In this study, different types of biochar (rice straw 'RSB', corn cob 'CCB', and Jatropha shell 'JSB' were used to evaluate the adsorption capacity of heavy metals removal from multiple-metal solutions (Cu, Mn, Zn, and Cd). Kinetics modeling has been examined to illustrate potential adsorption mechanisms. The results showed that the potential removal of metal is dependent on the metal and biochar types. The adsorption capacity of the biochars followed the order: RSB > JSB > CCB. In general, RSB and JSB biochars presented high potential removal of heavy metals from polluted water, which was higher than 90 and 80% after 2 hrs of contact time for all metals, respectively. According to the kinetics data, the pseudo-second-order model was agreed strongly with Cu, Mn, Zn, and Cd adsorption onto the biochars (R2 ≥ 0.97), indicating the dominance of specific adsorption process, i.e., chemisorption. In conclusion, this study revealed that RSB and JSB biochar have the potential to be a strong adsorbent for multiple-metal removal from wastewater.

Keywords: adsorption, biochar, chemisorption, polluted water

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Authors: A. Shebani, S. Iwnicki

Abstract:

Understanding the nature of wheel and rail wear in the railway field is of fundamental importance to the safe and cost effective operation of the railways. Twin disc wear testing is used extensively for studying wear of wheel and rail materials. The University of Huddersfield twin disc rig was used in this paper to examine the effect of surface conditions on wheel and rail wear measurement under a range of wheel/rail contact conditions, with and without contaminants. This work focuses on an investigation of the effect of dry, wet, and lubricated conditions and the effect of contaminants such as sand on wheel and rail wear. The wheel and rail wear measurements were carried out by using a replica material and an optical profilometer that allows measurement of wear in difficult location with high accuracy. The results have demonstrated the rate at which both water and oil reduce wheel and rail wear. Scratches and other damage were seen on the wheel and rail surfaces after the addition of sand and consequently both wheel and rail wear damage rates increased under these conditions. This work introduced the replica material and an optical instrument as effective tools to study the effect of surface conditions on wheel and rail wear.

Keywords: railway wheel/rail wear, surface conditions, twin disc test rig, replica material, Alicona profilometer

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Authors: Seyed Hamid Mirmohammad Sadeghi, Raffaella Sesana, Daniela Maffiodo

Abstract:

This study presents a procedure for friction calculation of column electric power steering (C-EPS) system which affects handling and comfort in driving. The friction losses estimation is obtained from experimental tests and mathematical calculation. Parts in C-EPS mainly involved in friction losses are bearings and worm gear. In the theoretical approach, the gear geometry and Hertz law were employed to measure the normal load and the sliding velocity and contact areas from the worm gears driving conditions. The viscous friction generated in the worm gear was obtained with a theoretical approach and the result was applied to model the friction in the steering system. Finally, by viscous friction coefficient and Coulomb friction coefficient, values of friction in worm gear were calculated. According to the Bearing Company and the characteristics of each bearing, the friction torques due to load and due to speed were calculated. A MATLAB Simulink model for calculating the friction in bearings and worm gear in C-EPS were done and the total friction value was estimated.

Keywords: friction, worm gear, column electric power steering system, simulink, bearing, EPS

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Authors: Elizabeth G. Hereford, Geoffrey W. Gearner

Abstract:

Logan’s Branch, within the Triplett Creek Watershed of Rowan County, Kentucky, is a waterway located near important agricultural and residential areas. Part of Logan’s Branch flows over an exposed black shale formation with elevated radioactivity and heavy metals. Three sites were chosen in relation to the formation and sampled five times over a thirty-day period during the recreational season. A fourth site in North Fork in Rowan County, Kentucky was also sampled periodically as it too has contact with the shale formation. These sites were then sampled monthly. All samples are analyzed for concentrations of Escherichia coli, heterotrophic bacteria, and total coliform bacteria utilizing the membrane filtration method and various culture media. Current data suggests that the radioactivity of the shale formation influences the bacteriological growth present in the waterway; however, further data will be collected and compared with that of my colleagues to confirm this trend.

Keywords: bacteriological analysis, Escherichia coli, heterotrophic bacteria, radioactive black shale formation, water quality

Procedia PDF Downloads 190