Search results for: theatrical show

Authors: Marwa Abida, Florian Gehring, Jamel Mars, Alexandre Vivet, Fakhreddine Dammak, Mohamed Haddar

Abstract:

The demand for bio-based materials in semi-structural and structural applications is constantly growing to conform to new environmental policies. Among them, Plant Fiber Reinforced Composites (PFRC) are attractive for the scientific community as well as the industrial world. Due to their relatively low densities and low environmental impact, vegetal fibers appear to be suitable as reinforcing materials for polymers. However, the major issue of plant fibers and PFRC in general is their hydrophilic behavior (high affinity to water molecules). Indeed, when absorbed, water causes fiber swelling and a loss of mechanical properties. Thus, the environmental loadings (moisture, temperature, UV) can strongly affect their mechanical properties and therefore play a critical role in the service life of PFRC. In order to analyze the influence of conditioning at relative humidity on the behavior of flax fiber reinforced composites, a preliminary study on flax fabrics has been conducted. The conditioning of the fabrics in different humid atmospheres made it possible to study the influence of the water content on the hygro-mechanical behavior of flax reinforcement through mechanical tensile tests. This work shows that increasing the relative humidity of the atmosphere induces an increase of the water content in the samples. It also brings up the significant influence of water content on the stiffness and elongation at break of the fabric, while no significant change of the breaking load is detected. Non-linear decrease of flax fabric rigidity and increase of its elongation at maximal force with the increase of water content are observed. It is concluded that water molecules act as a softening agent on flax fabrics. Two kinds of typical tensile curves are identified. Most of the tensile curves of samples show one unique linear region where the behavior appears to be linear prior to the first yarn failure. For some samples in which water content is between 2.7 % and 3.7 % (regardless the conditioning atmosphere), the emergence of a two-linear region behavior is pointed out. This phenomenon could be explained by local heterogeneities of water content which could induce premature local plasticity in some regions of the flax fabric sample behavior.

Keywords: hygro-mechanical behavior, hygroscopy, flax fabric, relative humidity, mechanical properties

Procedia PDF Downloads 185

Authors: Yaqing Hu

Abstract:

This paper puts forward a syntactic analysis involving multidominance and rightward movement in Chinese bi-comparatives, as in 'Yuehan bi Mali gao (John is taller than Mary).' It is argued here that the predicate of comparison is a shared constituent in two small clauses, namely one for the target and one for the standard; and then it moves rightward to form a degree phrase with the comparative morpheme. This proposal comes from four aspects. First, the example above can also be expressed in this way, 'A: Yuehan he Mali, shui gao? (John and Mary, who is taller?) B: Yuehan gao./Yuehan geng gao. (John is taller).' This shows that the gradable adjective is predicated of the target. In addition, according to a constraint on Chinese bi-comparatives, namely the target and the standard must be arguments of the predicate simultaneously, it is not unreasonable to assume that the gradable adjective may also be predicated of the standard. Second, subcomparatives are totally disallowed in Chinese, as in '*zhe-zhang zhuozi bi zhe-zhang yizi kuan chang. (This table is longer than this chair is wide.)' In order to save it from ungrammaticality, the target and the standard should be compared along the same dimension denoted by the gradable adjective. It may follow that in Chinese comparatives, having equal roles in the same eventuality, the target and the standard bear the same thematic relationship with the predicate of comparison. Third, verb-copy can appear in Chinese bi-comparatives, as in 'Yuehan qi ma bi Mali qi ma qi de kuai. (John rides horses faster than Mary does.)' The predicate qi seems to form a small clause with both the target and the standard. This might be supporting evidence that both the target and the standard share the predicate of comparison. Fourth, Chinese comparatives do have comparative morphemes, as in 'Yuehan bi Mali geng gao. (John is taller than Mary)', which is semantically equivalent to the first example above. Thus, it follows that one feature of Chinese comparative morphemes is that they can remain overt or covert in the syntax, which will not affect semantics. This further shows that comparative morphemes in bi-comparatives may not be able to saturate the degree argument denoted by the predicate of comparison due to its optionality in the structure. These four aspects present a challenge to the Direct Analysis used in Chinese comparatives since this approach would presume that the target and the standard somehow show independency with the predicate in the syntax. Meanwhile, this study also rejects the previous analysis of multidomiance in bi-comparatives in which the degree phrase comprised of the comparative morpheme and the gradable adjective may be shared by the standard when the comparative morpheme is covert. This syntactic analysis proposed in this study will therefore offer a different perspective of how to treat degree phrase in Chinese comparatives and may offer evidence to argue whether there is degree phrase movement in bi-comparatives as in its English counterparts.

Keywords: Chinese comparatives, degree phrase, movement, multidominance, syntactic analysis

Procedia PDF Downloads 324

Authors: Ying Jia Teoh

Abstract:

The Canning Basin is located between the Kimberley and Pilbara Precambrian cratonic blocks. It is a large but relatively poorly explored Paleozoic basin in remote Western Australia. During the early Ordovician period, the Australian continent was located near the equator. Middle Ordovician age Nita and Goldwyer Formations in Canning Basin are therefore warm water carbonates. The Nita Formation carbonates are a regressive sequence which conformably overlies the Goldwyer Formation. It contains numerous progradational cycles of limestone, vuggy dolomitized carbonate beds and shale deposited in subtidal to supratidal environments. The Goldwyer Formation contains transgressive shale sequences and regressive carbonates deposited in shallow subtidal conditions. The shales contain oil-prone Gloeocapsormorpha prisca-bearing source rocks. Llanvirnian relative sea-level fluctuations were reconstructed by using Fischer plots methodology for three key wells (wells McLarty 1, Looma 1 and Robert 1) in Broome Platform and compared with INPEFA data. The Goldwyer lower shale (interval Or1000P) shows increasing relative sea-level and this matches with a transgressive systems tract. Goldwyer middle carbonate (interval Or2000) shows relative sea-level drop and this matches with a regressive systems tract. Goldwyer upper shale (interval Or2000P) shows relative sea-level drop and this matches with a transgressive systems tract. Nita Formation Leo Member (interval Or3000) shows a relative sea level drop and this matches with a regressive systems tract. The Nita Formation Cudalgarra Member (intervals Or3000P and Or4000) with transgressive systems tract then this is followed by a regressive systems tract. This pattern matches with the relative sea-level curves in wells McLarty 1 and Robert 1. The correlation is weak for parts of well Looma 1. This is probably influenced by the fact that the thickness of this section is quite small. As a conclusion, Fischer plots for the Llanvirnian Goldwyer and Nita Formations show good agreement with the third order global sea level cycles of Haq and others. Fischer plots are generally correlated well with trend and cyclicity determined by INPEFA curves and as a method of cross-checking INPEFA data and sea-level change.

Keywords: canning basin, Fischer plots, Llanvirnian, middle Ordovician, sea-level fluctuations, stratigraphy

Procedia PDF Downloads 278

Authors: Juan Cuesta

Abstract:

Satellite observation is a fundamental component of air pollution monitoring systems, such as the large-scale Copernicus Programme. Next-generation satellite sensors, in orbit or programmed in the future, offer great potential to observe major air pollutants, such as tropospheric ozone, with unprecedented spatial and temporal coverage. However, satellite approaches developed for remote sensing of tropospheric ozone are based solely on measurements from a single instrument in a specific spectral range, either thermal infrared or ultraviolet. These methods offer sensitivity to tropospheric ozone located at the lowest at 3 or 4 km altitude above the surface, thus limiting their applications for ozone pollution analysis. Indeed, no current observation of a single spectral domain provides enough information to accurately measure ozone in the atmospheric boundary layer. To overcome this limitation, we have developed a multispectral synergism approach, called "IASI+GOME2", at the Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA) laboratory. This method is based on the synergy of thermal infrared and ultraviolet observations of respectively the Infrared Atmospheric Sounding Interferometer (IASI) and the Global Ozone Monitoring Experiment-2 (GOME-2) sensors embedded in MetOp satellites that have been in orbit since 2007. IASI+GOME2 allowed the first satellite observation of ozone plumes located between the surface and 3 km of altitude (what we call the lowermost troposphere), as it offers significant sensitivity in this layer. This represents a major advance for the observation of ozone in the lowermost troposphere and its application to air quality analysis. The ozone abundance derived by IASI+GOME2 shows a good agreement with respect to independent observations of ozone based on ozone sondes (a low mean bias, a linear correlation larger than 0.8 and a mean precision of about 16 %) around the world during all seasons. Using IASI+GOME2, lowermost tropospheric ozone pollution plumes are quantified both in terms of concentrations and also in the amounts of ozone photo-chemically produced along transport and also enabling the characterization of the ozone pollution, such as what occurred during the lockdowns linked to the COVID-19 pandemic. The current paper will show the IASI+GOME2 multispectral approach to observe the lowermost tropospheric ozone from space and an overview of several applications on different continents and at a global scale.

Keywords: ozone pollution, multispectral synergism, satellite, air quality

Procedia PDF Downloads 77

Authors: Abdreheman Seid Abdella

Abstract:

This study examined instructors willingness, self-efficacy beliefs, attitudes and knowledge about provisions of instructional accommodations for students with disabilities in universities. Major concepts used in this study operationally defined and some models of disability were reviewed. Questionnaires were distributed to a total of 181 instructors from four universities and quantitative data was generated. Then to analyze the data, appropriate methods of data analysis were employed. The result indicated that on average instructors had positive willingness, strong self-efficacy beliefs and positive attitudes towards providing instructional accommodations. In addition, the result showed that the majority of participants had moderate level of knowledge about provision of instructional accommodations. Concerning the relationship between instructors background variables and dependent variables, the result revealed that location of university and awareness raising training about Inclusive Education showed statistically significant relationship with all dependent variables (willingness, self-efficacy beliefs, attitudes and knowledge). On the other hand, gender and college/faculty did not show a statistically significant relationship. In addition, it was found that among the inter-correlation of dependent variables, the correlation between attitudes and willingness to provide accommodations was the strongest. Furthermore, using multiple linear regression analysis, this study also indicated that predictor variables like self-efficacy beliefs, attitudes, knowledge and teaching methodology training made statistically significant contribution to predicting the criterion willingness. Predictor variables like willingness and attitudes made statistically significant contribution to predicting self-efficacy beliefs. Predictor variables like willingness, Special Needs Education course and self-efficacy beliefs made statistically significant contribution to predict attitudes. Predictor variables like Special Needs Education courses, the location of university and willingness made statistically significant contribution to predicting knowledge. Finally, using exploratory factor analysis, this study showed that there were four components or factors each that represent the underlying constructs of willingness and self-efficacy beliefs to provide instructional accommodations items, five components for attitudes towards providing accommodations items and three components represent the underlying constructs for knowledge about provisions of instructional accommodations items. Based on the findings, recommendations were made for improving the situation of instructional accommodations in Ethiopian universities.

Keywords: willingness, self-efficacy belief, attitude, knowledge

Procedia PDF Downloads 266

Authors: Sayed Mansour, Mohammad Aldoasri, Nagib Elmarzugi, Nadia A. Al-Mouallimi

Abstract:

The archaeological large stone used in construction of ancient Pharaonic tombs, temples, obelisks and other sculptures, always subject to physicomechanical deterioration and destructive forces, leading to their partial or total broken. The task of reassembling this type of artifact represent a big challenge for the conservators. Recently, the researchers are turning to new technologies to improve the properties of traditional adhesive materials and techniques used in re-assembly of broken large stone. The epoxy resins are used extensively in stone conservation and re-assembly of broken stone because of their outstanding mechanical properties. The introduction of nanoparticles to polymeric adhesives at low percentages may lead to substantial improvements of their mechanical performances in structural joints and large objects. The aim of this study is to evaluate the effectiveness of clay nanoparticles in enhancing the performances of epoxy adhesives used in re-assembly of archaeological massive stone by adding proper amounts of those nanoparticles. The nanoparticles reinforced epoxy nanocomposite was prepared by direct melt mixing with a nanoparticles content of 3% (w/v), and then mould forming in the form of rectangular samples, and used as adhesive for experimental stone samples. Scanning electron microscopy (SEM) was employed to investigate the morphology of the prepared nanocomposites, and the distribution of nanoparticles inside the composites. The stability and efficiency of the prepared epoxy-nanocomposites and stone block assemblies with new formulated adhesives were tested by aging artificially the samples under different environmental conditions. The effect of incorporating clay nanoparticles on the mechanical properties of epoxy adhesives was evaluated comparatively before and after aging by measuring the tensile, compressive, and Elongation strength tests. The morphological studies revealed that the mixture process between epoxy and nanoparticles has succeeded with a relatively homogeneous morphology and good dispersion in low nano-particles loadings in epoxy matrix was obtained. The results show that the epoxy-clay nanocomposites exhibited superior tensile, compressive, and Elongation strength. Moreover, a marked improvement of the mechanical properties of stone joints increased in all states by adding nano-clay to epoxy in comparison with pure epoxy resin.

Keywords: epoxy resins, nanocomposites, clay nanoparticles, re-assembly, archaeological massive stones, mechanical properties

Procedia PDF Downloads 111

Authors: Mohammad Tarek Al Muallim, Ozhan Duzenli, Ceyhun Ilguy

Abstract:

Passive sonar is a method for detecting acoustic signals in the ocean. It detects the acoustic signals emanating from external sources. With passive sonar, we can determine the bearing of the target only, no information about the range of the target. Target Motion Analysis (TMA) is a process to estimate the position and speed of a target using passive sonar information. Since bearing is the only available information, the TMA technique called Bearing-only TMA. Many TMA techniques have been developed. However, until now, there is not a very effective method that could be used to always track an unknown target and extract its moving trace. In this work, a design of effective Bearing-only TMA Algorithm is done. The measured bearing angles are very noisy. Moreover, for multi-beam sonar, the measurements is quantized due to the sonar beam width. To deal with this, modified gain extended Kalman filter algorithm is used. The algorithm is fine-tuned, and many modules are added to improve the performance. A special validation gate module is used to insure stability of the algorithm. Many indicators of the performance and confidence level measurement are designed and tested. A new method to detect if the target is maneuvering is proposed. Moreover, a reactive optimal observer maneuver based on bearing measurements is proposed, which insure converging to the right solution all of the times. To test the performance of the proposed TMA algorithm a simulation is done with a MATLAB program. The simulator program tries to model a discrete scenario for an observer and a target. The simulator takes into consideration all the practical aspects of the problem such as a smooth transition in the speed, a circular turn of the ship, noisy measurements, and a quantized bearing measurement come for multi-beam sonar. The tests are done for a lot of given test scenarios. For all the tests, full tracking is achieved within 10 minutes with very little error. The range estimation error was less than 5%, speed error less than 5% and heading error less than 2 degree. For the online performance estimator, it is mostly aligned with the real performance. The range estimation confidence level gives a value equal to 90% when the range error less than 10%. The experiments show that the proposed TMA algorithm is very robust and has low estimation error. However, the converging time of the algorithm is needed to be improved.

Keywords: target motion analysis, Kalman filter, passive sonar, bearing-only tracking

Procedia PDF Downloads 393

Authors: Asena Biber, Ates Gul Ergun, Seda Bulut

Abstract:

Based on the literature, there are large numbers of studies investigating the relationship between culture and leadership effectiveness. Although giving effective speeches is vital characteristic for a leader to be perceived as effective, to our knowledge, there is no research study the determinants of perceived effective leader speech. The aim of this study is to find the effects of both culture and voice pitch on perceptions of leader's speech effectiveness. Our hypothesis is that people from high power distance countries will perceive leaders' speech effective when the leader's voice pitch is high, comparing with people from relatively low power distance countries. The participants of the study were 36 undergraduate students (12 Pakistanis, 12 Nigerians, and 12 Turks) who are studying in Turkey. National power distance scores of Nigerians ranked as first, Turks ranked as second and Pakistanis ranked as third. There are two independent variables in this study; three nationality groups that representing three levels of power distance and voice pitch of the leader which is manipulated as high and low levels. Researchers prepared an audio to manipulate high and low conditions of voice pitch. A professional whose native language is English read the predetermined speech in high and low voice pitch conditions. Voice pitch was measured using Hertz (Hz) and Decibel (dB). Each nationality group (Pakistan, Nigeria, and Turkey) were divided into groups of six students who listened to either the low or high pitch conditions in the cubicles of the laboratory. It was expected from participants to listen to the audio and fill in the questionnaire which was measuring the leadership effectiveness on a response scale ranging from 1 to 5. To determine the effects of nationality and voice pitch on perceived effectiveness of leader' voice pitch, 3 (Pakistani, Nigerian, and Turk) x 2 (low voice pitch and high voice pitch) two way between subjects analysis of variances was carried out. The results indicated that there was no significant main effect of voice pitch and interaction effect on perceived effectiveness of the leader’s voice pitch. However, there was a significant main effect of nationality on perceived effectiveness of the leader's voice pitch. Based on the results of Turkey’s HSD post-hoc test, only the perceived effectiveness of the leader's speech difference between Pakistanis and Nigerians was statistically significant. The results show that the hypothesis of this study was not supported. As limitations of the study, it is of importance to mention that the sample size should be bigger. Also, the language of the questionnaire and speech should be in the participant’s native language in further studies.

Keywords: culture, leadership effectiveness, power distance, voice pitch

Procedia PDF Downloads 180

Authors: Wasan Ismail Khalil, Hisham Khalid Ahmed, Zainab Ali

Abstract:

Structural Lightweight Aggregate Concrete (SLWAC) has been developed in recent years because it reduces the dead load, cost, thermal conductivity and coefficient of thermal expansion of the structure. So SLWAC has the advantage of being a relatively green building material. Lightweight Aggregate (LWA) is either occurs as natural material such as pumice, scoria, etc. or as artificial material produced from different raw materials such as expanded shale, clay, slate, etc. The use of SLWAC in Iraq is limited due to the lack in natural LWA. The existence of Iraqi clay deposit with different types and characteristics leads to the idea of producing artificial expanded clay aggregate. The main aim in this work is to present of the properties of artificial LWA produced in the laboratory. Available local bentonite clay which occurs in the Western region of Iraq was used as raw material to produce the LWA. Sodium silicate as liquid industrial waste material from glass plant was mixed with bentonite clay in mix proportion 1:1 by weight. The manufacturing method of the lightweight aggregate including, preparation and mixing of clay and sodium silicate, burning of the mixture in the furnace at the temperature between 750-800˚C for two hours, and finally gradually cooling process. The produced LWA was then crushed to small pieces then screened on standard sieve series and prepared with grading which conforms to the specifications of LWA. The maximum aggregate size used in this investigation is 10 mm. The chemical composition and the physical properties of the produced LWA are investigated. The results indicate that the specific gravity of the produced LWA is 1.5 with the density of 543kg/m3 and water absorption of 20.7% which is in conformity with the international standard of LWA. Many trail mixes were carried out in order to produce LWAC containing the artificial LWA produced in this research. The selected mix proportion is 1:1.5:2 (cement: sand: aggregate) by weight with water to cement ratio of 0.45. The experimental results show that LWAC has oven dry density of 1720 kg/m3, water absorption of 8.5%, the thermal conductivity of 0.723 W/m.K and compressive strength of 23 N/mm2. The SLWAC produced in this research can be used in the construction of different thermal insulated buildings and masonry units. It can be concluded that the SLWA produced in this study contributes to sustainable development by, using industrial waste materials, conserving energy, enhancing the thermal and structural efficiency of concrete.

Keywords: expanded clay, lightweight aggregate, structural lightweight aggregate concrete, sustainable

Procedia PDF Downloads 325

Authors: Benoît Leclercq, Ilse Depraetere

Abstract:

The goal of this presentation is to shed new light on the semantics and pragmatics of be able to. It presents the results of a corpus analysis based on data from the BNC (British National Corpus), and discusses these results in light of a specific stance on the semantics-pragmatics interface taking into account recent developments. Be able to is often discussed in relation to can and could, all of which can be used to express ability. Such an onomasiological approach often results in the identification of usage constraints for each expression. In the case of be able to, it is the formal properties of the modal expression (unlike can and could, be able to has non-finite forms) that are in the foreground, and the modal expression is described as the verb that conveys future ability. Be able to is also argued to expressed actualised ability in the past (I was able/could to open the door). This presentation aims to provide a more accurate pragmatic-semantic profile of be able to, based on extensive data analysis and one that is embedded in a very explicit view on the semantics-pragmatics interface. A random sample of 3000 examples (1000 for each modal verb) extracted from the BNC was analysed to account for the following issues. First, the challenge is to identify the exact semantic range of be able to. The results show that, contrary to general assumption, be able to does not only express ability but it shares most of the root meanings usually associated with the possibility modals can and could. The data reveal that what is called opportunity is, in fact, the most frequent meaning of be able to. Second, attention will be given to the notion of actualisation. It is commonly argued that be able to is the preferred form when the residue actualises: (1) The only reason he was able to do that was because of the restriction (BNC, spoken) (2) It is only through my imaginative shuffling of the aces that we are able to stay ahead of the pack. (BNC, written) Although this notion has been studied in detail within formal semantic approaches, empirical data is crucially lacking and it is unclear whether actualisation constitutes a conventional (and distinguishing) property of be able to. The empirical analysis provides solid evidence that actualisation is indeed a conventional feature of the modal. Furthermore, the dataset reveals that be able to expresses actualised 'opportunities' and not actualised 'abilities'. In the final part of this paper, attention will be given to the theoretical implications of the empirical findings, and in particular to the following paradox: how can the same expression encode both modal meaning (non-factual) and actualisation (factual)? It will be argued that this largely depends on one's conception of the semantics-pragmatics interface, and that this need not be an issue when actualisation (unlike modality) is analysed as a generalised conversational implicature and thus is considered part of the conventional pragmatic layer of be able to.

Keywords: Actualisation, Modality, Pragmatics, Semantics

Procedia PDF Downloads 125

Authors: Geeta Kumari, Prabu Vairakannu

Abstract:

Underground coal gasification (UCG) technology is an efficient and an economic in-situ clean coal technology, which converts unmineable coals into calorific valuable gases. This technology avoids ash disposal, coal mining, and storage problems. CO₂ gas can be a potential gasifying medium for UCG. CO₂ is a greenhouse gas and, the liberation of this gas to the atmosphere from thermal power plant industries leads to global warming. Hence, the capture and reutilization of CO₂ gas are crucial for clean energy production. However, the reactivity of high ash Indian coals with CO₂ needs to be assessed. In the present study, two varieties of Indian coals (low ash and high ash) are used for thermogravimetric analyses (TGA). Two low ash north east Indian coals (LAC) and a typical high ash Indian coal (HAC) are procured from the coal mines of India. Low ash coal with 9% ash (LAC-1) and 4% ash (LAC-2) and high ash coal (HAC) with 42% ash are used for the study. TGA studies are carried out to evaluate the activation energy for pyrolysis and gasification of coal under N₂ and CO₂ atmosphere. Coats and Redfern method is used to estimate the activation energy of coal under different temperature regimes. Volumetric model is assumed for the estimation of the activation energy. The activation energy estimated under different temperature range. The inherent properties of coals play a major role in their reactivity. The results show that the activation energy decreases with the decrease in the inherent percentage of coal ash due to the ash layer hindrance. A reverse trend was observed with volatile matter. High volatile matter of coal leads to the estimation of low activation energy. It was observed that the activation energy under CO₂ atmosphere at 400-600°C is less as compared to N₂ inert atmosphere. At this temperature range, it is estimated that 15-23% reduction in the activation energy under CO₂ atmosphere. This shows the reactivity of CO₂ gas with higher hydrocarbons of the coal volatile matters. The reactivity of CO₂ with the volatile matter of coal might occur through dry reforming reaction in which CO₂ reacts with higher hydrocarbon, aromatics of the tar content. The observed trend of Ea in the temperature range of 150-200˚C and 400-600˚C is HAC > LAC-1 >LAC-2 in both N₂ and CO₂ atmosphere. At the temperature range of 850-1000˚C, higher activation energy is estimated when compared to those values in the temperature range of 400-600°C. Above 800°C, char gasification through Boudouard reaction progressed under CO₂ atmosphere. It was observed that 8-20 kJ/mol of activation energy is increased during char gasification above 800°C compared to volatile matter pyrolysis between the temperature ranges of 400-600°C. The overall activation energy of the coals in the temperature range of 30-1000˚C is higher in N₂ atmosphere than CO₂ atmosphere. It can be concluded that higher hydrocarbons such as tar effectively undergoes cracking and reforming reactions in presence of CO₂. Thus, CO₂ gas is beneficial for the production of high calorific value syngas using high ash Indian coals.

Keywords: clean coal technology, CO₂ gasification, activation energy, underground coal gasification

Procedia PDF Downloads 166

Authors: Yumeho Obata, Mariko Era, Takayoshi Kawahara, Takahide Kanyama, Hiroshi Morita

Abstract:

Dermatophagoides farinae is major mite allergens in indoors. D. farinae is often swarm over powder products (e.g. wheat flour), because it feeds on starch or protein that are included in them. Eating powder products which are mixed D.farinae causes various allergic symptoms. Therefore, the creation of food additive agents with high safety and control of mite effect is required. Fatty acid salts and spices are known that have pesticidal activities. This study describes the effects of fatty acid salts and spices against Dermatophagoides farinae. Materials and Methods: Potassium salts of 9 fatty acids (C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C18:1, C18:2, C18:3) were prepared by mixing the fatty acid with the appropriate amount of KOH solution to a concentration of 175 mM and pH 10.5. C12Cu and C12Zn were selected as other fatty acid salts. Cayenne pepper, habanero, Japanese pepper, mustard, jalapeno pepper, curry aroma and cinnamon were selected as spices. D. farina, have been cultured in laboratory. To rear the mites, double-soled dishes containing of sterilized food were put on the big plastic container (30.0 × 20.0 × 20.0cm) which had 100% ammonium nitrate solution in the bottom. Plastic container was placed on incubator at 25 °C and 64 % relative humidity (RH) under dark condition. Sterilized food composed of dried bonito flakes and dried yeast (Ebios), 1:1 by weight. The antiproliferative method, sample and medium culture were mixed in double-soled dish and kept at 25 °C and 64 % RH. Decrease rates were determined 1 week and 4 week after treatment under microscope. D. farina was considered to be dead if appendages did not move when prodded with a pin. Results and Conclusions: The results show that the fatty acids potassium showed no antiproliferative effects against D. farinae. On the other hand, Japanese pepper, mustard, curry aroma and cinnamon were effective to decrease propagative rate (over 80 %) after treatment for 1 week against D. farina. Japanese pepper, curry aroma and cinnamon were effective to decrease propagative rate (approximately 100 %) after treatment for 4 weeks against D. farina. Especially, Japanese pepper and cinnamon showed the fasted and the most consecutive antiproliferative effects. These results indicate that Japanese pepper and cinnamon have high antiproliferative effects against D. farina and suggest spices will be used as a food additive agent.

Keywords: fatty acid salts, spices, antiproliferative effects, dermatophagoides farinae

Procedia PDF Downloads 231

Authors: Louise H. Gracioso, Marcela P.G. Baltazar, Ingrid R. Avanzi, Bruno Karolski, Luciana J. Gimenes, Claudio O. Nascimento, Elen A. Perpetuo

Abstract:

Introduction: Higher copper concentrations promote a selection pressure on organisms such as plants, fungi and bacteria, which allows surviving only the resistant organisms to the contaminated site. This selective pressure keeps only the organisms most resistant to a specific condition and subsequently increases their bioremediation potential. Despite the bacteria importance for biosphere maintenance, it is estimated that only a small fraction living microbial species has been described and characterized. Due to the molecular biology development, tools based on analysis 16S ribosomal RNA or another specific gene are making a new scenario for the characterization studies and identification of microorganisms in the environment. News identification of microorganisms methods have also emerged like Biotyper (MALDI / TOF), this method mass spectrometry is subject to the recognition of spectroscopic patterns of conserved and features proteins for different microbial species. In view of this, this study aimed to isolate bacteria resistant to copper present in a Copper Processing Area (Sossego Mine, Canaan, PA) and identifies them in two different methods: Recent (spectrometry mass) and conventional. This work aimed to use them for a future bioremediation of this Mining. Material and Methods: Samples were collected at fifteen different sites of five periods of times. Microorganisms were isolated from mining wastes by culture enrichment technique; this procedure was repeated 4 times. The isolates were inoculated into MJS medium containing different concentrations of chloride copper (1mM, 2.5mM, 5mM, 7.5mM and 10 mM) and incubated in plates for 72 h at 28 ºC. These isolates were subjected to mass spectrometry identification methods (Biotyper – MALDI/TOF) and 16S gene sequencing. Results: A total of 105 strains were isolated in this area, bacterial identification by mass spectrometry method (MALDI/TOF) achieved 74% agreement with the conventional identification method (16S), 31% have been unsuccessful in MALDI-TOF and 2% did not obtain identification sequence the 16S. These results show that Biotyper can be a very useful tool in the identification of bacteria isolated from environmental samples, since it has a better value for money (cheap and simple sample preparation and MALDI plates are reusable). Furthermore, this technique is more rentable because it saves time and has a high performance (the mass spectra are compared to the database and it takes less than 2 minutes per sample).

Keywords: copper mining area, bioremediation, microorganisms, identification, MALDI/TOF, RNA 16S

Procedia PDF Downloads 372

Authors: Boris Nemzer, Tania Reyes-Izquierdo, Zbigniew Pietrzkowski

Abstract:

Glucosinolate is a family of glucosides that can be found in a family of brassica vegetables. Upon the damage of the plant, glucosinolate breakdown by an internal enzyme myrosinase (thioglucosidase; EC 3.2.3.1) into isothiocyanates, such as sulforaphane. Sulforaphane is formed by glucoraphanin cleaving the sugar off by myrosinase and rearranged. Sulforaphane nitrile is formed in the same reaction as sulforaphane with the active of epithiospecifier protein (ESP). Most common food processing procedure would break the plant and mix the glucoraphanin and myrosinase together, and the formed sulforaphane would be further degraded. The purpose of this study is to understand the glucoraphanin/sulforaphane and the myrosinase activity of broccoli seeds germinated at a different time and technological processing conditions that keep the activity of the enzyme to form sulforaphane. Broccoli seeds were germinated in the house. Myrosinase activities were tested as the glucose content using glucose assay kit and measured UV-Vis spectrophotometer. Glucosinolates were measured by HPLC/DAD. Sulforaphane was measured using HPLC-DAD and GC/MS. The 6 hr germinated sprouts have a myrosinase activity 32.2 mg glucose/g, which is comparable with 12 and 24 hour germinated seeds and higher than dry seeds. The glucoraphanin content in 6 hour germinated sprouts is 13935 µg/g which is comparable to 24 hour germinated seeds and lower than the dry seeds. GC/MS results show that the amount of sulforaphane is higher than the amount of sulforaphane nitrile in seeds, 6 hour and 24 hour germinated seeds. The ratio of sulforaphane and sulforaphane nitrile is high in 6 hour germinated seeds, which indicates the inactivated ESP in the reaction. After evaluating the results, the short time germinated seeds can be used as the source of glucoraphanin and myrosinase supply to form potential higher sulforaphane content. Broccoli contains glucosinolates, glucoraphanin (4-methylsulfinylbutyl glucosinolate), which is an important metabolite with health-promoting effects. In the pilot clinical study, we observed the effects of a glucosinolates/glucoraphanin-rich extract from short time germinated broccoli seeds on blood adenosine triphosphate (ATP), reactive oxygen species (ROS) and lactate levels. A single dose of 50 mg of broccoli sprouts extract increased blood levels of ATP up to 61% (p=0.0092) during the first 2 hours after the ingestion. Interestingly, this effect was not associated with an increase in blood ROS or lactate. When compared to the placebo group, levels of lactate were reduced by 10% (p=0.006). These results indicate that broccoli germinated seed extract may positively affect the generation of ATP in humans. Due to the preliminary nature of this work and promising results, larger clinical trials are justified.

Keywords: broccoli glucosinolates, glucoraphanin, germinated seeds, myrosinase, adenosine triphosphate

Procedia PDF Downloads 288

Authors: Christoph Lohr, Hanna Wund, Peter Elsner, Kay André Weidenmann

Abstract:

Injection molding is one of the most commonly used techniques in the industrial polymer processing. In the conventional process of injection molding, the liquid polymer is injected into the cavity of the mold, where the polymer directly starts hardening at the cooled walls. To compensate the shrinkage, which is caused predominantly by the immediate cooling, holding pressure is applied. Through that whole process, residual stresses are produced by the temperature difference of the polymer melt and the injection mold and the relocation of the polymer chains, which were oriented by the high process pressures and injection speeds. These residual stresses often weaken or change the structural behavior of the parts or lead to deformation of components. One solution to reduce the residual stresses is the use of variothermal processing. Hereby the mold is heated – i.e. near/over the glass transition temperature of the polymer – the polymer is injected and before opening the mold and ejecting the part the mold is cooled. For the next cycle, the mold gets heated again and the procedure repeats. The rapid heating and cooling of the mold are realized indirectly by convection of heated and cooled liquid (here: water) which is pumped through fluid channels underneath the mold surface. In this paper, the influences of variothermal processing on the residual stresses are analyzed with samples in a larger scale (500 mm x 250 mm x 4 mm). In addition, the influence on functional elements, such as abrupt changes in wall thickness, bosses, and ribs, on the residual stress is examined. Therefore the polycarbonate samples are produced by variothermal and isothermal processing. The melt is injected into a heated mold, which has in our case a temperature varying between 70 °C and 160 °C. After the filling of the cavity, the closed mold is cooled down varying from 70 °C to 100 °C. The pressure and temperature inside the mold are monitored and evaluated with cavity sensors. The residual stresses of the produced samples are illustrated by birefringence where the effect on the refractive index on the polymer under stress is used. The colorful spectrum can be uncovered by placing the sample between a polarized light source and a second polarization filter. To show the achievement and processing effects on the reduction of residual stress the birefringence images of the isothermal and variothermal produced samples are compared and evaluated. In this comparison to the variothermal produced samples have a lower amount of maxima of each color spectrum than the isothermal produced samples, which concludes that the residual stress of the variothermal produced samples is lower.

Keywords: birefringence, injection molding, polycarbonate, residual stress, variothermal processing

Procedia PDF Downloads 281

Authors: Mahdieh Zamzamzadeh, Ahmad Abdullah Saifizul, Rahizar Ramli

Abstract:

The road accidents involving heavy vehicles have been showing worrying trends and, year after year, have increased the concern and awareness levels on safety of roads and transportations especially in developing countries like Malaysia. Statistics of road crashes continue to show that there are many contributing factors on the capability of a heavy vehicle to stop on safe distance and ultimately prevent traffic crashes. However, changes in the road condition due to weather variations and the vehicle dynamic specifications such as loading conditions and speed are the main risk factors because they will affect a heavy vehicle’s braking performance due to losing control and not being able to stop the vehicle, and in many cases will cause wheel lock up and accordingly skidding. Predicting heavy vehicle skidding distance is crucial for accident reconstruction and roadside safety engineers. Despite this, formal tools to study heavy vehicle skidding distance before stopping completely are totally limited, and most researchers have only considered braking distance in their studies. As a possible new tool, this work presents the iterative use of vehicle dynamic simulations to study heavy vehicle-roadway interaction in order to predict wheel lock up effects on skidding distance and safety. This research addresses the influence of the vehicle and road conditions on skidding distance after wheel lock up and presents a precise analysis of skidding phenomenon. The vehicle speed, vehicle loading condition and road friction parameters were all varied in a simulation-based analysis. In order to simulate the wheel lock up situation, a heavy vehicle model was constructed and simulated using multibody vehicle dynamics simulation software, and careful analysis was made on the conditions which caused the skidding distance to increase or decrease through a method using to predict skidding distance as part of braking distance. By applying many simulations, the results were quite revealing relation between the heavy vehicles loading condition, various sets of speed and road coefficient of friction and their interaction effect on the skidding distance. A number of results are presented which illustrate how the heavy vehicle overloading can seriously affect the skidding distance. Moreover, the results of simulation give the skid mark length, which is a necessary input data during accident reconstruction involving emergency braking.

Keywords: accident reconstruction, Braking, heavy vehicle, skidding distance, skid mark, wheel lock up

Procedia PDF Downloads 494

Authors: Ketsada Sutthiumporn, Sittichot Thongkaw, Malee Santikunaporn

Abstract:

In Thailand, biodiesel has been utilized as an attractive substitute of petroleum diesel and the government imposes a mandatory biodiesel blending requirement in transport sector to improve energy security, support agricultural sector and reduce emissions. Though biodiesel blend has many advantages over diesel fuel such as improved lubricity, low sulfur content and higher flash point, there are still some technical problems such as oxidative stability, poor cold- flow properties and impurity. Such problems were related to the fatty acid composition in feedstock. Moreover, Thailand has announced the use of low sulfur diesel as a base diesel and will be continually upgrading to EURO 5 in 2023. With ultra low sulfur content, it may affect the diesel fuel properties especially lubricity as well. Therefore, in this study, the physical and chemical properties of palm oil-based biodiesel in low sulfur diesel blends from different producers will be investigated by standard methods per ASTM and EN. Also, its economic benefits based on diesel price structure in Thailand will be highlighted. The appropriate biodiesel blend ratio can affect the physico-chemical properties and reasonable price in the country. Properties of biodiesel, including specific gravity, kinematic viscosity, FAME composition, flash point, sulfur, water, oxidation stability and lubricity were measured by standard methods of ASTM and EN. The results show that the FAME composition of biodiesel has the fatty acid of C12:0 to C20:1, mostly in C16:0, C18:0, C18:1, and C18:2, which were main characteristic compositions of palm biodiesel. The physical and chemical properties of biodiesel blended diesel was found to be increases with an increasing amount of biodiesel such as specific gravity, flash point and kinematic viscosity while sulfur value was decreased. Moreover, in this study, the various properties of each biodiesel blends were plotted to determine the appropriate proportional range of biodiesel-blended diesel with an optimum fuel price.It can be seen that the amount of B100 can be filled from 1% up to 7% in which the quality was in accordance with Notification of the department of Energy business.The understanding of relation between physico-chemical properties of palm oil-based biodiesel and pricing is beneficial to guide the better development of desired feedstock in Thailand and to implement biodiesel blends with comparative price and diesel engine performance.

Keywords: fatty acid methyl ester, biodiesel, fuel price structure, palm oil in Thailand

Procedia PDF Downloads 112

Authors: Nargiza Nuralieva

Abstract:

This meta-analysis investigates the effectiveness of mental health interventions tailored for international students in China, with a specific focus on Uzbek students and Silk Road scholarship recipients. The comprehensive literature review synthesizes existing studies, papers, and reports, evaluating the outcomes, limitations, and cultural considerations of these programs. Data selection targets mental health programs for international students, honing in on a subset analysis related to Uzbek students and Silk Road scholarship recipients. The analysis encompasses diverse outcome measures, such as reported stress levels, utilization rates of mental health services, academic performance, and more. Results reveal a consistent and statistically significant reduction in reported stress levels, emphasizing the positive impact of these interventions. Utilization rates of mental health services witness a significant increase, highlighting the accessibility and effectiveness of support. Retention rates show marked improvement, though academic performance yields mixed findings, prompting nuanced exploration. Psychological well-being, quality of life, and overall well-being exhibit substantial enhancements, aligning with the overarching goal of holistic student development. Positive outcomes are observed in increased help-seeking behavior, positive correlations with social support, and significant reductions in anxiety levels. Cultural adaptation and satisfaction with interventions both indicate positive outcomes, underscoring the effectiveness of culturally sensitive mental health support. The findings emphasize the importance of tailored mental health interventions for international students, providing novel insights into the specific needs of Uzbek students and Silk Road scholarship recipients. This research contributes to a nuanced understanding of the multifaceted impact of mental health programs on diverse student populations, offering valuable implications for the design and refinement of future interventions. As educational institutions continue to globalize, addressing the mental health needs of international students remains pivotal for fostering inclusive and supportive learning environments.

Keywords: international students, mental health interventions, cross-cultural support, silk road scholarship, meta-analysis

Procedia PDF Downloads 53

Authors: Ipek Kivanc, Demet Ozgur-Unluakin

Abstract:

Over the past years, technological innovations and advancements have played an important role in the industrial world. Due to technological improvements, the degree of complexity of the systems has increased. Hence, all systems are getting more uncertain that emerges from increased complexity, resulting in more cost. It is challenging to cope with this situation. So, implementing efficient planning of maintenance activities in such systems are getting more essential. Partially Observable Markov Decision Processes (POMDPs) are powerful tools for stochastic sequential decision problems under uncertainty. Although maintenance optimization in a dynamic environment can be modeled as such a sequential decision problem, POMDPs are not widely used for tackling maintenance problems. However, they can be well-suited frameworks for obtaining optimal maintenance policies. In the classical representation of the POMDP framework, the system is denoted by a single node which has multiple states. The main drawback of this classical approach is that the state space grows exponentially with the number of state variables. On the other side, factored representation of POMDPs enables to simplify the complexity of the states by taking advantage of the factored structure already available in the nature of the problem. The main idea of factored POMDPs is that they can be compactly modeled through dynamic Bayesian networks (DBNs), which are graphical representations for stochastic processes, by exploiting the structure of this representation. This study aims to demonstrate how maintenance planning of dynamic systems can be modeled with factored POMDPs. An empirical maintenance planning problem of a dynamic system consisting of four partially observable components deteriorating in time is designed. To solve the empirical model, we resort to Symbolic Perseus solver which is one of the state-of-the-art factored POMDP solvers enabling approximate solutions. We generate some more predefined policies based on corrective or proactive maintenance strategies. We execute the policies on the empirical problem for many replications and compare their performances under various scenarios. The results show that the computed policies from the POMDP model are superior to the others. Acknowledgment: This work is supported by the Scientific and Technological Research Council of Turkey (TÜBİTAK) under grant no: 117M587.

Keywords: factored representation, maintenance, multi-component system, partially observable Markov decision processes

Procedia PDF Downloads 133

Authors: Castillo-Acevedo J, Mena-Rivero R, Silva-Poot H

Abstract:

In Mexico, as largely of the developing countries, the rural housing is a study object, since the diversity of constructive idiosyncrasies for locality, involves various factors that make it vulnerable; an important aspect of study is the progressive deterioration that is seen in the rural housing. Various social programs, contribute financial resources in the field of housing to provide support for families living in rural areas, however, they do not provide a coordination with the self-construction that is usually the way in which is built in these areas. The present study, exposes the physical situation and an economic assessment that presents the rural self-constructed housing in three rural communities in the south of the state of Quintana Roo, Mexico, which were built with funding from federal social programs. The information compilation was carried out in a period of seven months in which there was used the intentional sampling of typical cases, where the object study was the housing constructed with supports of the program “Rural Housing” between the year 2009 and 2014. Instruments were used as the interview, ballot papers of observation, ballot papers of technical verification and various measuring equipment laboratory for the classification of pathologies; for the determination of some pathologies constructive Mexican standards were applied how NMX-C-192-ONNCCE, NMX-C-111-ONNCCE, NMX-C-404-ONNCCE and finally used the software of Opus CMS ® with the help of tables of the National Consumer Price Index (CPI) for update of costs and wages according to the line of being applied in Mexico, were used for an economic valuation. The results show 11 different constructive pathologies and exposes greater presence with the 22.50% to the segregation of the concrete; the economic assessment shows that 80% of self-constructed housing, exceed the cost of construction it would have compared to a similar dwelling built by a construction company; It is also exposed to the 46.10% of the universe of study represent economic losses in materials to the social activities by houses not built. The system of self-construction used by the social programs, affect to some extent the program objectives applied in underserved areas, as implicit and additional costs affect the economic capacity of beneficiaries who invest time and effort in an activity that are not specialists, which this research provides foundations for sustainable alternatives or possibly eliminate the practice of self-construction of implemented social programs in marginalized rural communities in the south of state of Quintana Roo, Mexico.

Keywords: economic valuation, pathologies constructive, rural housing, social programs

Procedia PDF Downloads 530

Authors: Soiduate Ogoye-Atanga

Abstract:

During funeral ceremonies, it has become common for attendees to jostle for burial programs in some southern Nigerian towns. Beginning from ordinary typewritten text only sheets of paper in the 1980s to their current digitally formatted multicolor magazine style, burial programs continue to be collected and kept in homes where they remain as archival documents of family photo histories and as a veritable form of leveraging family status and visibility in a social economy through the inclusion of lots of choreographically arranged photographs and text. The biographical texts speak of idealized and often lofty and aestheticized accomplishments of deceased peoples, which are often corroborated by an accompanying section of tributes from first the immediate family members, and then from affiliations as well as organizations deceased people belonged, in the form of scanned letterheaded corporate tributes. Others speak of modest biographical texts when the deceased accomplished little. Usually, in majority of the cases, the display of photographs and text in these programs follow a trajectory of historical compartmentalization of the deceased, beginning from parentage to the period of youth, occupation, retirement, and old age as the case may be, which usually drives from black and white historical photographs to the color photography of today. This compartmentalization follows varied models but is designed to show the deceased in varying activities during his lifetime. The production of these programs ranges from the extremely expensive and luscious full colors of near fifty-eighty pages to bland and very simplified low-quality few-page editions in a single color and no photographs, except on the cover. Cost and quality, therefore, become determinants of varying family status and social visibility. By a critical selection of photographs and text, family members construct an idealized image of deceased people and themselves, concentrating on mutuality based on appropriate sartorial selections, socioeconomic grade, and social temperaments that are framed to corroborate the public’s perception of them. Burial magazines, therefore, serve purposes beyond their primary use; they symbolize an orchestrated social site for image-making and the validation of the social status of families, shaped by prior family histories.

Keywords: biographical texts, burial programs, compartmentalization, magazine, multicolor, photo-histories, social status

Procedia PDF Downloads 184

Authors: Roya Bakhtiar, Alireza Abdolmohammadi, Hadi Hajarian, Zahra Nikousefat, Davood, Kalantar-Neyestanaki

Abstract:

The objective of the present study was to determine the polymorphism in the leptin (332G>A) and its association with biometric traits in Sanjabi sheep. For this purpose, blood samples from 96 rams were taken, and tail length, width tail, circumference tail, body length, body width, and height were simultaneously recorded. PCR was performed using specific primer to amplify 463 bp fragment including exon 3 of leptin gene, and PCR products were digested by Cail restriction enzymes. The 332G>A (at 332th nucleotide of exon 3 leptin gene) that caused an amino acid change from Arg to Gln was detected by Cail (CAGNNNCTG) endonuclease, as the endonuclease cannot cut this region if G nucleotide is located in this position. Three genotypes including GG (463), GA (463, 360and 103 bp) and GG (360 bp and 103 bp) were identified after digestion by enzyme. The estimated frequencies of three genotypes including GG, GA, and AA for 332G>A locus were 0.68, 0.29 and 0.03 and those were 0.18 and 0.82 for A and G alleles, respectively. In the current study, chi-square test indicated that 332G>A positions did not deviate from the Hardy–Weinberg (HW) equilibrium. The most important reason to show HW equation was that samples used in this study belong to three large local herds with a traditional breeding system having random mating and without selection. Shannon index amount was calculated which represent an average genetic variation in Sanjabi rams. Also, heterozygosity estimated by Nei index indicated that genetic diversity of mutation in the leptin gene is moderate. Leptin gene polymorphism in the 332G>A had significant effect on body length (P<0.05) trait, and individuals with GA genotype had significantly the higher body length compared to other individuals. Although animals with GA genotype had higher body width, this difference was not statistically significant (P>0.05). This non-synonymous SNP resulted in different amino acid changes at codon positions111(R/Q). As leptin activity is localized, at least in part, in domains between amino acid residues 106-1406, it is speculated that the detected SNP at position 332 may affect the activity of leptin and may lead to different biological functions. Based to our results, due to significant effect of leptin gene polymorphism on body size traits, this gene may be used a candidate gene for improving these traits.

Keywords: body size, Leptin gene, PCR-RFLP, Sanjabi sheep

Procedia PDF Downloads 337

Authors: Siri Marthe Arbo, Afaf Saai, Sture Sørli, Mette Nedreberg

Abstract:

This work aims to establish a reliable approach for optimizing a Laser Metal Deposition (LMD) process for a critical maritime component, based on the material properties and structural performance required by the maritime industry. The component of interest is a water jet impeller, for which specific requirements for material properties are defined. The developed approach is based on the assessment of the effects of LMD process parameters on microstructure and material performance of standard AM 2205 duplex stainless steel powder. Duplex stainless steel offers attractive properties for maritime applications, combining high strength, enhanced ductility and excellent corrosion resistance due to the specific amounts of ferrite and austenite. These properties are strongly affected by the microstructural characteristics in addition to microstructural defects such as porosity and welding defects, all strongly influenced by the chosen LMD process parameters. In this study, the influence of deposition speed and heat input was evaluated. First, the influences of deposition speed and heat input on the microstructure characteristics, including ferrite/austenite fraction, amount of porosity and welding defects, were evaluated. Then, the achieved mechanical properties were evaluated by standard testing methods, measuring the hardness, tensile strength and elongation, bending force and impact energy. The measured properties were compared to the requirements of the water jet impeller. The results show that the required amounts of ferrite and austenite can be achieved directly by the LMD process without post-weld heat treatments. No intermetallic phases were observed in the material produced by the investigated process parameters. A high deposition speed was found to reduce the ductility due to the formation of welding defects. An increased heat input was associated with reduced strength due to the coarsening of the ferrite/austenite microstructure. The microstructure characterizations and measured mechanical performance demonstrate the great potential of the LMD process and generate a valuable database for the optimization of the LMD process for duplex stainless steels.

Keywords: duplex stainless steel, laser metal deposition, process optimization, microstructure, mechanical properties

Procedia PDF Downloads 212

Authors: Yun Chen, David Penton, Fazlul Karim, Santosh Aryal, Shahriar Wahid, Peter Taylor, Susan M. Cuddy

Abstract:

Droughts have severely affected Afghanistan over the last four decades, leading to critical food shortages where two-thirds of the country’s population are in a food crisis. Long years of conflict have lowered the country’s ability to deal with hazards such as drought, which can rapidly escalate into disasters. Understanding the spatial and temporal distribution of droughts is needed to be able to respond effectively to disasters and plan for future occurrences. This study used Standardized Precipitation Evapotranspiration Index (SPEI) at monthly, seasonal, and annual temporal scales to map the spatiotemporal change dynamics of drought characteristics (distribution, frequency, duration, and severity) in Afghanistan. SPEI indices were mapped for river basins, disaggregated into 189 sub-catchments, using monthly precipitation and potential evapotranspiration derived from temperature station observations from 1980 to 2017. The results show these multi-dimensional drought characteristics vary along different years, change among sub-catchments, and differ across temporal scales. During the 38 years, the driest decade and period are the 2000s and 1999–2022, respectively. The 2000–01 water year is the driest, with the whole country experiencing ‘severe’ to ‘extreme’ drought, more than 53% (87 sub-catchments) suffering the worst drought in history, and about 58% (94 sub-catchments) having ‘very frequent’ drought (7 to 8 months) or ‘extremely frequent’ drought (9 to 10 months). The estimated seasonal duration and severity present significant variations across the study area and throughout the study period. The nation also suffered from recurring droughts with varying length and intensity in 2004, 2006, 2008, and, most recently, 2011. There is a trend towards increasing drought with longer duration and higher severity extending all over sub-catchments from southeast to north and central regions. These datasets and maps help to fill the knowledge gap on detailed sub-catchment scale meteorological drought characteristics in Afghanistan. The study findings improve our understanding of the influences of climate change on drought dynamics and can guide catchment planning for reliable adaptation to and mitigation against future droughts.

Keywords: SPEI, precipitation, evapotranspiration, climate extremes

Procedia PDF Downloads 89

Authors: Martín Pratto Burgos

Abstract:

The Engineering School of the University of the Republic in Uruguay offers an Introductory Mathematical Course from the second semester of 2019. This course has been designed to assist students in preparing themselves for math courses that are essential for Engineering Degrees, namely Math1, Math2, and Math3 in this research. The research proposes to build a model that can accurately predict the student's activity and academic progress based on their performance in the three essential Mathematical courses. Additionally, there is a need for a model that can forecast the incidence of the Introductory Mathematical Course in the three essential courses approval during the first academic year. The techniques used are Principal Component Analysis and predictive modelling using the Generalised Linear Model. The dataset includes information from 5135 engineering students and 12 different characteristics based on activity and course performance. Two models are created for a type of data that follows a binomial distribution using the R programming language. Model 1 is based on a variable's p-value being less than 0.05, and Model 2 uses the stepAIC function to remove variables and get the lowest AIC score. After using Principal Component Analysis, the main components represented in the y-axis are the approval of the Introductory Mathematical Course, and the x-axis is the approval of Math1 and Math2 courses as well as student activity three years after taking the Introductory Mathematical Course. Model 2, which considered student’s activity, performed the best with an AUC of 0.81 and an accuracy of 84%. According to Model 2, the student's engagement in school activities will continue for three years after the approval of the Introductory Mathematical Course. This is because they have successfully completed the Math1 and Math2 courses. Passing the Math3 course does not have any effect on the student’s activity. Concerning academic progress, the best fit is Model 1. It has an AUC of 0.56 and an accuracy rate of 91%. The model says that if the student passes the three first-year courses, they will progress according to the timeline set by the curriculum. Both models show that the Introductory Mathematical Course does not directly affect the student’s activity and academic progress. The best model to explain the impact of the Introductory Mathematical Course on the three first-year courses was Model 1. It has an AUC of 0.76 and 98% accuracy. The model shows that if students pass the Introductory Mathematical Course, it will help them to pass Math1 and Math2 courses without affecting their performance on the Math3 course. Matching the three predictive models, if students pass Math1 and Math2 courses, they will stay active for three years after taking the Introductory Mathematical Course, and also, they will continue following the recommended engineering curriculum. Additionally, the Introductory Mathematical Course helps students to pass Math1 and Math2 when they start Engineering School. Models obtained in the research don't consider the time students took to pass the three Math courses, but they can successfully assess courses in the university curriculum.

Keywords: machine-learning, engineering, university, education, computational models

Procedia PDF Downloads 90

Authors: Jianlun Zhang, Christine Lim

Abstract:

Local food is one of the most attractive elements to tourists. The role of local cuisine in destination branding is very important because it is the distinctive identity that helps tourists remember the destination. The objectives of this study are: (1) Test the direct relation between the cognitive image of destination food and tourists’ intention to eat local food. (2) Examine the mediating effect of tourists’ desire to try destination food on the relationship between the cognitive image of local food and tourists’ intention to eat destination food. (3) Study the moderating effect of tourists’ perceived difficulties in finding local food on the relationship between tourists’ desire to try destination food and tourists’ intention to eat local food. To achieve the goals of this study, Macanese cuisine is selected as the destination food. Macau is located in Southeastern China and is a former colonial city of Portugal. The taste and texture of Macanese cuisine are unique because it is a fusion of cuisine from many countries and regions of mainland China. As people travel to seek authentically exotic experience, it is important to investigate if the food image of Macau leaves a good impression on tourists and motivate them to try local cuisine. A total of 449 Chinese tourists were involved in this study. To analyze the data collected, partial least square-structural equation modelling (PLS-SEM) technique is employed. Results suggest that the cognitive image of Macanese cuisine has a direct effect on tourists’ intention to eat Macanese cuisine. Tourists’ desire to try Macanese cuisine mediates the cognitive image-intention relationship. Tourists’ perceived difficulty of finding Macanese cuisine moderates the desire-intention relationship. The lower tourists’ perceived difficulty in finding Macanese cuisine is, the stronger the desire-intention relationship it will be. There are several practical implications of this study. First, the government tourism website can develop an authentic storyline about the evolvement of local cuisine, which provides an opportunity for tourists to taste the history of the destination and create a novel experience for them. Second, the government should consider the development of food events, restaurants, and hawker businesses. Third, to lower tourists’ perceived difficulty in finding local cuisine, there should be locations of restaurants and hawker stalls with clear instructions for finding them on the websites of the government tourism office, popular tourism sites, and public transportation stations in the destination. Fourth, in the post-COVID-19 era, travel risk will be a major concern for tourists. Therefore, when promoting local food, the government tourism website should post images that show food safety and hygiene.

Keywords: cognitive image of destination food, desire to try destination food, intention to eat food in the destination, perceived difficulties of finding local cuisine, PLS-SEM

Procedia PDF Downloads 187

Authors: Hyeuk Ju Ko, Eui Ju Lee

Abstract:

Many electronic devices are powered by various rechargeable batteries such as lithium-ion today, but occasionally the batteries undergo thermal runaway and cause fire, explosion, and other hazards. If a battery fire should occur in an electronic device of vehicle and aircraft cabin, it is important to quickly extinguish the fire and cool the batteries to minimize safety risks. Attempts to minimize these risks have been carried out by many researchers but the number of study on the successful extinguishment is limited. Because most rechargeable batteries are operated on the ion state with electron during charge and discharge of electricity, and the reaction of this electrolyte has a big difference with normal combustion. Here, we focused on the effect of ions on reaction stability and pollutant emissions during combustion process. The other importance for understanding ionized fuel combustion could be found in high efficient and environment-friendly combustion technologies, which are used to be operated an extreme condition and hence results in unintended flame instability such as extinction and oscillation. The use of electromagnetic energy and non-equilibrium plasma is one of the way to solve the problems, but the application has been still limited because of lack of excited ion effects in the combustion process. Therefore, the understanding of ion role during combustion might be promised to the energy safety society including the battery safety. In this study, the effects of an ionized fuel on the flame stability and pollutant emissions were experimentally investigated in the hydrocarbon jet diffusion flames. The burner used in this experiment consisted of 7.5 mm diameter tube for fuel and the gaseous fuels were ionized with the ionizer (SUNJE, SPN-11). Methane (99.9% purity) and propane (commercial grade) were used as a fuel and open ambient air was used as an oxidizer. As the performance of ionizer used in the experiment was evaluated at first, ion densities of both propane and methane increased linearly with volume flow rate but the ion density of propane is slightly higher than that of methane. The results show that the overall flame stability and shape such as flame length has no significant difference even in the higher ion concentration. However, the fuel ionization affects to the pollutant emissions such as NOx and soot. NOx and CO emissions measured in post flame region decreased with increasing fuel ionization, especially at high fuel velocity, i.e. high ion density. TGA analysis and morphology of soot by TEM indicates that the fuel ionization makes soot to be matured.

Keywords: battery fires, ionization, jet flames, stability, NOx and soot

Procedia PDF Downloads 182

Authors: Rohit Dey, Sailendra Karra

Abstract:

This paper aims at solving the problem of multi-target searching in a Global Positioning System (GPS) denied environment using swarm robots with limited sensing and communication abilities. Typically, existing swarm-based search algorithms rely on the presence of a global coordinate system (vis-à-vis, GPS) that is shared by the entire swarm which, in turn, limits its application in a real-world scenario. This can be attributed to the fact that robots in a swarm need to share information among themselves regarding their location and signal from targets to decide their future course of action but this information is only meaningful when they all share the same coordinate frame. The paper addresses this very issue by eliminating any dependency of a search algorithm on the need of a predetermined global coordinate frame by the unification of the relative coordinate of individual robots when within the communication range, therefore, making the system more robust in real scenarios. Our algorithm assumes that all the robots in the swarm are equipped with range and bearing sensors and have limited sensing range and communication abilities. Initially, every robot maintains their relative coordinate frame and follow Levy walk random exploration until they come in range with other robots. When two or more robots are within communication range, they share sensor information and their location w.r.t. their coordinate frames based on which we unify their coordinate frames. Now they can share information about the areas that were already explored, information about the surroundings, and target signal from their location to make decisions about their future movement based on the search algorithm. During the process of exploration, there can be several small groups of robots having their own coordinate systems but eventually, it is expected for all the robots to be under one global coordinate frame where they can communicate information on the exploration area following swarm search techniques. Using the proposed method, swarm-based search algorithms can work in a real-world scenario without GPS and any initial information about the size and shape of the environment. Initial simulation results show that running our modified-Particle Swarm Optimization (PSO) without global information we can still achieve the desired results that are comparable to basic PSO working with GPS. In the full paper, we plan on doing the comparison study between different strategies to unify the coordinate system and to implement them on other bio-inspired algorithms, to work in GPS denied environment.

Keywords: bio-inspired search algorithms, decentralized control, GPS denied environment, swarm robotics, target searching, unifying coordinate systems

Procedia PDF Downloads 133

Authors: Tomasz Holecki, Hanna Dobrowolska

Abstract:

In the Polish health care system, nurses and midwives are obliged to regularly update their professional knowledge. It is all regulated by the Law on the nurse and midwife’s profession and the code of ethics. The professional self-governing body (County Chamber of Nurses and Midwives) is obliged to organize ongoing training for them so that maintaining accessibility and availability to the high quality of educational services could be possible at all levels of post-graduate education. The aim of this study is an analysis of post-graduate education organized by the County Chamber of Nurses and Midwives in the city of Katowice, Poland, as a professional self-governing body operating in the area of Silesian province inhabited by almost 5 million citizens which bring together more than 30 thousand professionally active nurses and midwives. In the years 2000-2017, the self-government of nurses and midwives trained over 50,000 people. The education and supervision system over the labour of nurses and midwives establishes exercising control by a self-governing body. In practice, this means that conducting activities aimed at creating legal regulations and organizational conditions, as well as the practical implementation of courses, belongs to the professional self-government of nurses and midwives. The most of specialization courses that were provided from their own funds came from membership fees. The biggest group was participants of specializations in the fields of cardiac, anesthesia, and preventive nursing. The smallest group of people participated in such specializations as neonatal, emergency, and obstetrics nursing. The most popular specialist courses were in the fields of the electrocardiogram and cardiopulmonary resuscitation, whereas the least popular were the ones in the fields of protective vaccinations of neonates. So-called 'soft training-courses' in the fields of improvement of social skills and management were also provided. The research shows that a vast majority of nurses and midwives are interested in raising their professional qualifications. Specialist courses and selected fields of qualification courses received the most concrete attention. In light of conducted research, one can assert that cooperation inside the community of nurses and midwives provides access to high-quality education and training services regularly used by a wide circle of them. The presented results exemplify a level of real interest in specialist and qualification training-courses and also show sources of financing them.

Keywords: nurses and midwives, ongoing training, postgraduate education, specialist training-courses

Procedia PDF Downloads 102

Authors: Martina Santobuono, Wing Sze Chan, Elettra D'Amico, Henriette Selck

Abstract:

Chemicals in modern society are fundamental in many different aspects of daily human life. We use a wide range of substances, including polychlorinated compounds, pesticides, plasticizers, and pharmaceuticals, to name a few. These compounds are excessively produced, and this has led to their introduction to the environment and food resources. Municipal and industrial effluents, landfills, and agricultural runoffs are a few examples of sources of chemical pollution. Many of these compounds, such as pharmaceuticals, have been proven to mimic or alter the performance of the hormone system, thus disrupting its normal function and altering the behavior and reproductive capability of non-target organisms. Antidepressants are pharmaceuticals commonly detected in the environment, usually in the range of ng L⁻¹ and µg L⁻¹. Since they are designed to have a biological effect at low concentrations, they might pose a risk to the native species, especially if exposure lasts for long periods. Hydrophobic antidepressants, like the selective serotonin reuptake inhibitor (SSRI) Sertraline, can sorb to the particles in the water column and eventually accumulate in the sediment compartment. Thus, deposit-feeding organisms may be at particular risk of exposure. The polychaete Capitella teleta is widespread in estuarine organically enriched sediments, being a key deposit-feeder involved in geochemistry processes happening in sediments. Since antidepressants are neurotoxic chemicals and endocrine disruptors, the aim of this work was to test if sediment-associated Sertraline impacts burrowing- and feeding behavior as well as reproduction capability in Capitella teleta in a chronic exposure set-up, which could better mimic what happens in the environment. 7 days old juveniles were selected and exposed to different concentrations of Sertraline for an entire generation until the mature stage was reached. This work was able to show that some concentrations of Sertraline altered growth and the time of first reproduction in Capitella teleta juveniles, potentially disrupting the population’s capability of survival. Acknowledgments: This Ph.D. position is part of the CHRONIC project “Chronic exposure scenarios driving environmental risks of Chemicals”, which is an Innovative Training Network (ITN) funded by the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Actions (MSCA).

Keywords: antidepressants, Capitella teleta, chronic exposure, endocrine disruption, sublethal endpoints, neurotoxicity

Procedia PDF Downloads 92