Search results for: open flow channel

Authors: I. Tiahi

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The aim of the current paper is to explore educational practices in contemporary Algeria. Researches explain such practices bear traditional approach and the overlooks modern teaching methods such as mobile learning. That is why the research output of examining student engagement in respect of mobile learning was obtained from the following objectives: (1) To evaluate the current practice of English language teaching within Algerian higher education institutions, (2) To explore how social constructivism theory and m-learning help students’ engagement in the classroom and (3) To explore the feasibility and acceptability of m-learning amongst institutional leaders. The methodology underpins a case study and action research. For the case study, the researcher engaged with 6 teachers, 4 institutional leaders, and 30 students subjected for semi-structured interviews and classroom observations to explore the current teaching methods for English as a foreign language. For the action research, the researcher applied an intervention course to investigate the possibility and implications for future implementation of mobile learning in higher education institutions. The results were deployed using thematic analysis. The research outcome showed that the disengagement of students in English language learning has many aspects. As seen from the interviews from the teachers, the researcher found that they do not have enough resources except for using ppt for some teacher. According to them, the teaching method they are using is mostly communicative and competency-based approach. Teachers informed that students are disengaged because they have psychological barriers. In classroom setting, the students are conscious about social approval from the peer, and thus if they are to face negative reinforcement which would damage their image, it is seen as a preventive mechanism to be scared of committing mistakes. This was also very reflective in this finding. A lot of other arguments can be given for this claim; however, in Algerian setting, it is usual practice where teachers do not provide positive reinforcement which is open up students for possible learning. Thus, in order to overcome such a psychological barrier, proper measures can be taken. On a conclusive remark, it is evident that teachers, students, and institutional leaders provided positive feedback for using mobile learning. It is not only motivating but also engaging in learning processes. Apps such as Kahoot, Padlet and Slido were well received and thus can be taken further to examine its higher impact in Algerian context. Thus, in the future, it will be important to implement m-learning effectively in higher education to transform the current traditional practices into modern, innovative and active learning. Persuasion for this change for stakeholder may be challenging; however, its long-term benefits can be reflective from the current research paper.

Keywords: Algerian context, mobile learning, social constructivism, student engagement

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Authors: Georgios Koronis, Arlindo Silva

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This study seeks to understand the mechanical behavior of a natural fiber reinforced composite (epoxy/flax) in more depth, utilizing both experimental and numerical methods. It is attempted to identify relationships between the design parameters and the product performance, understand the effect of noise factors and reduce process variations. Optimization of the mechanical performance of manufactured goods has recently been implemented by numerous studies for green composites. However, these studies are limited and have explored in principal mass production processes. It is expected here to discover knowledge about composite’s manufacturing that can be used to design artifacts that are of low batch and tailored to niche markets. The goal is to reach greater consistency in the performance and further understand which factors play significant roles in obtaining the best mechanical performance. A prediction of response function (in various operating conditions) of the process is modeled by the DoE. Normally, a full factorial designed experiment is required and consists of all possible combinations of levels for all factors. An analytical assessment is possible though with just a fraction of the full factorial experiment. The outline of the research approach will comprise of evaluating the influence that these variables have and how they affect the composite mechanical behavior. The coupons will be fabricated by the vacuum infusion process defined by three process parameters: flow rate, injection point position and fiber treatment. Each process parameter is studied at 2-levels along with their interactions. Moreover, the tensile and flexural properties will be obtained through mechanical testing to discover the key process parameters. In this setting, an experimental phase will be followed in which a number of fabricated coupons will be tested to allow for a validation of the design of the experiment’s setup. Finally, the results are validated by performing the optimum set of in a final set of experiments as indicated by the DoE. It is expected that after a good agreement between the predicted and the verification experimental values, the optimal processing parameter of the biocomposite lamina will be effectively determined.

Keywords: design of experiments, flax fabrics, mechanical performance, natural fiber reinforced composites

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Authors: Apurva Patil, Ashay Aswale, Akshay Kulkarni, Shubham Bharadiya

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The potential benefit of gravity compensation of linkages in mechanisms using springs to reduce actuator requirements is well recognized, but practical applications have been elusive. Although existing methods provide exact spring balance, they require additional masses or auxiliary links, or all the springs used originate from the ground, which makes the resulting device bulky and space-inefficient. This paper uses a method of static balancing of mechanisms with conservative loads such as gravity and spring loads using non-zero-free-length springs with child–parent connections and no auxiliary links. Application of this method to the developed arm of a humanoid robot is presented here. Spring balancing is particularly important in this case because the serial chain of linkages has to work against gravity.This work involves approximate spring balancing of the open-loop chain of linkages using minimization of potential energy variance. It uses the approach of flattening the potential energy distribution over the workspace and fuses it with numerical optimization. The results show the considerable reduction in actuator torque requirement with practical spring design and arrangement. Reduced actuator torque facilitates the use of lower end actuators which are generally smaller in weight and volume thereby lowering the space requirements and the total weight of the arm. This is particularly important for humanoid robots where the parent actuator has to handle the weight of the subsequent actuators as well. Actuators with lower actuation requirements are more energy efficient, thereby reduce the energy consumption of the mechanism. Lower end actuators are lower in cost and facilitate the development of low-cost devices. Although the method provides only an approximate balancing, it is versatile, flexible in choosing appropriate control variables that are relevant to the design problem and easy to implement. The true potential of this technique lies in the fact that it uses a very simple optimization to find the spring constant, free-length of the spring and the optimal attachment points subject to the optimization constraints. Also, it uses physically realizable non-zero-free-length springs directly, thereby reducing the complexity involved in simulating zero-free-length springs from non-zero-free-length springs. This method allows springs to be attached to the preceding parent link, which makes the implementation of spring balancing practical. Because auxiliary linkages can be avoided, the resultant arm of the humanoid robot is compact. The cost benefits and reduced complexity can be significant advantages in the development of this arm of the humanoid robot.

Keywords: actuator torque, child-parent connections, spring balancing, the arm of a humanoid robot

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Authors: Quoc Hung Le Pham

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In the field of language study, classifier is an interesting research feature. In the world’s languages, some languages have classifier system, some do not. Mandarin Chinese and Vietnamese languages are a rich classifier system, however, because of the language system, the cognitive, cultural differences, so that the syntactic structure of classifier of them also dissimilar. When using Mandarin Chinese classifiers must collocate with nouns or verbs, in the lexical category it is not like nouns or verbs, belong to the open class. But some scholars believe that Mandarin Chinese measure words are similar to English and other Indo European languages. The word hanging on the structure and word formation (suffix), is a closed class. Compared to other languages, such as Chinese, Vietnamese, Thai and other Asian languages are still belonging to the classifier language’s second type, this type of language is classifier, it is in the majority of quantity must exist, and following deictic, anaphoric or quantity appearing together, not separation between its modified noun, also known as numeral classifier language. Main syntactic structure of Chinese classifiers are as follows: ‘quantity+measure+noun’, ‘pronoun+measure+noun’, ‘pronoun+quantity+measure+noun’, ‘prefix+quantity+measure +noun’, ‘quantity +adjective + measure +noun’, ‘ quantity (above 10 whole number), + duo (多)measure +noun’, ‘ quantity (around 10) + measure + duo (多) +noun’. Main syntactic structure of Vietnamese classifiers are: ‘quantity+measure+noun’, ‘ measure+noun+pronoun’, ‘quantity+measure+noun+pronoun’, ‘measure+noun+prefix+ quantity’, ‘quantity+measure+noun+adjective', ‘duo (多) +quanlity+measure+noun’, ‘quantity+measure+adjective+pronoun (quantity word could not be 1)’, ‘measure+adjective+pronoun’, ‘measure+pronoun’. In daily life, classifiers are commonly used, if Chinese learners failed to standardize this using catergory, because the negative impact might occur on their verbal communication. The richness of the Chinese classifier system contributes to the complexity in the study of the system by foreign learners, especially in the inter language of Vietnamese learners. As above mentioned, Vietnamese language also has a rich system of classifiers, however, the basic structure order of two languages are similar but both still have differences. These similarities and dissimilarities between Chinese and Vietnamese classifier systems contribute significantly to the common errors made by Vietnamese students while they acquire Chinese, which are distinct from the errors made by students from the other language background. This article from a comparative perspective of language, has an orientation towards Chinese and Vietnamese languages commonly used in classifiers semantics and structural form two aspects. This comparative study aims to identity Vietnamese students while learning Chinese classifiers may face some negative transference of mother language, beside that through the analysis of the classifiers questionnaire, find out the causes and patterns of the errors they made. As the preliminary analysis shows, Vietnamese students while learning Chinese classifiers made some errors such as: overuse classifier ‘ge’(个); misuse the other classifiers ‘*yi zhang ri ji’(yi pian ri ji), ‘*yi zuo fang zi’(yi jian fang zi), ‘*si zhang jin pai’(si mei jin pai); homonym words ‘dui, shuang, fu, tao’ (对、双、副、套), ‘ke, li’ (颗、粒).

Keywords: acquisition, classifiers, negative transfer, Vietnamse learners

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Authors: Shimeles Terefe Mengistue, Ascensión Del Olmo, Paola Marziani, Mirjana Pović, María Angeles Martínez-Carballo, Jaime Perea, Isabel M. Árquez

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Quasars have historically been classified into two distinct classes, radio-loud (RL) and radio-quiet (RQ), taking into account the presence and absence of relativistic radio jets, respectively. The absence of spectra with a high S/N ratio led to the impression that all quasars (QSOs) are spectroscopically similar. Although different attempts were made to unify these two classes, there is a long-standing open debate involving the possibility of a real physical dichotomy between RL and RQ quasars. In this work, we present new high S/N spectra of 11 extremely powerful jetted quasars with radio-to-optical flux density ratio > 1000 that concomitantly cover the low-ionization emission of Mgii𝜆2800 and Hbeta𝛽 as well as the Feii blends in the redshift range 0.35 < z < 1, observed at Calar Alto Observatory (Spain). This work aims to quantify broad emission line differences between RL and RQ quasars by using the four-dimensional eigenvector 1 (4DE1) parameter space and its main sequence (MS) and to check the effect of powerful radio ejection on the low ionization broad emission lines. Emission lines are analysed by making two complementary approaches, a multicomponent non-linear fitting to account for the individual components of the broad emission lines and by analysing the full profile of the lines through parameters such as total widths, centroid velocities at different fractional intensities, asymmetry, and kurtosis indices. It is found that broad emission lines show large reward asymmetry both in Hbeta𝛽 and Mgii2800A. The location of our RL sources in a UV plane looks similar to the optical one, with weak Feii UV emission and broad Mgii2800A. We supplement the 11 sources with large samples from previous work to gain some general inferences. The result shows, compared to RQ, our extreme RL quasars show larger median Hbeta full width at half maximum (FWHM), weaker Feii emission, larger 𝑀BH, lower 𝐿bol/𝐿Edd, and a restricted space occupation in the optical and UV MS planes. The differences are more elusive when the comparison is carried out by restricting the RQ population to the region of the MS occupied by RL quasars, albeit an unbiased comparison matching 𝑀BH and 𝐿bol/𝐿Edd suggests that the most powerful RL quasars show the highest redward asymmetries in Hbeta.

Keywords: galaxies, active, line, profiles, quasars, emission lines, supermassive black holes

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Authors: Anna Ghosh, Dominic Shields, Ceri McIntosh, Stephen Crank

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A 29-year-old male was a referral to the maxillofacial unit following a referral from his general dental practitioner via a routine pathway regarding a large periapical lesion on the LR4 with root resorption. The patient was asymptomatic, the LR4 vital and unrestored, and this was an incidental finding at a routine check-up. The patient's past medical history was unremarkable. Examination revealed no extra or intra-oral pathology and non-mobile teeth. No focal neurology was detected. An orthopantogram demonstrated a well-defined unilocular corticated radiolucency associated with the LR4. The root appeared shortened with the radiolucency between the root and a radio-opacity, possibly representing the displacement of the apical tip of the tooth. It was recommended that the referring general practitioner should proceed with orthograde root canal therapy, after which time exploration, enucleation, and retrograde root filling of the LR4 would be carried out by a maxillofacial unit. The patient was reviewed six months later where, due to the COVID-19 pandemic, the patient had been unable to access general dental services for the root canal treatment. He was still entirely asymptomatic. A one-year review was planned in the hope this would allow time for the orthograde root canal therapy to be completed. At this review, the orthograde root canal therapy had still not been completed. Interestingly, a repeat orthopantogram revealed a significant reduction in size with good bony infill and a significant reduction in the size of the lesion. Due to the ongoing delays with primary care dental therapy, the patient was subsequently internally referred to the restorative dentistry department for care. The patient was seen again by oral and maxillo-facial surgery in mid-2022 where he still reports this tooth as asymptomatic with no focal neurology. The patient's history was fully reviewed, and noted that 15 years previously, the patient underwent open reduction and internal fixation of a left angle of mandible fracture. Temporary IMF involving IMF screws and fixation wires were employed to maintain occlusion during plating and subsequently removed post-operatively. It is proposed that the radiolucency was, as a result of the IMF screw placement, penetrating the LR4 root resulting in resorption of the tooth root and development of a radiolucency. This case highlights the importance of careful screw size and physical site location, and placement of IMF screws, as there can be permeant damage to a patient’s dentition.

Keywords: facial trauma, inter-maxillary fixation, mandibular radiolucency, oral and maxillo-facial surgery

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Authors: Vijay Shankar

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In the era of water scarcity, effective use of water via irrigation requires good methods for determining crop water needs. Implementation of irrigation scheduling programs requires an accurate estimate of water use by the crop. Moisture depletion from the root zone represents the consequent crop evapotranspiration (ET). A numerical model for simulating soil water depletion in the root zone has been developed by taking into consideration soil physical properties, crop and climatic parameters. The governing differential equation for unsaturated flow of water in the soil is solved numerically using the fully implicit finite difference technique. The water uptake by plants is simulated by using three different sink functions. The non-linear model predictions are in good agreement with field data and thus it is possible to schedule irrigations more effectively. The present paper describes irrigation scheduling based on moisture depletion from the different layers of the root zone, obtained using different sink functions for three cash, oil and forage crops: cotton, safflower and barley, respectively. The soil is considered at a moisture level equal to field capacity prior to planting. Two soil moisture regimes are then imposed for irrigated treatment, one wherein irrigation is applied whenever soil moisture content is reduced to 50% of available soil water; and other wherein irrigation is applied whenever soil moisture content is reduced to 75% of available soil water. For both the soil moisture regimes it has been found that the model incorporating a non-linear sink function which provides best agreement of computed root zone moisture depletion with field data, is most effective in scheduling irrigations. Simulation runs with this moisture uptake function result in saving 27.3 to 45.5% & 18.7 to 37.5%, 12.5 to 25% % &16.7 to 33.3% and 16.7 to 33.3% & 20 to 40% irrigation water for cotton, safflower and barley respectively, under 50 & 75% moisture depletion regimes over other moisture uptake functions considered in the study. Simulation developed can be used for an optimized irrigation planning for different crops, choosing a suitable soil moisture regime depending upon the irrigation water availability and crop requirements.

Keywords: irrigation water, evapotranspiration, root uptake models, water scarcity

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Authors: Gebreselassie Sebhatleab

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According to the Global Peace Index report (GPI, 2023), global peacefulness has deteriorated by more than 0.42%. Old and new conflicts, COVID-19, and political and cultural polarization are the main drivers of conflicts in the world. The 2022 was the deadliest year for armed conflict in the history of the GPI. In Ethiopia, over half a million people died in the Tigray war, which was the largest conflict death event since the 1994 Rwandan genocide. In total, 84 countries recorded an improvement, while 79 countries recorded a deterioration in peacefulness across the globe. The Russia-Ukraine war and its consequences were the main drivers of the deterioration in peacefulness globally. Both Russia and Ukraine are now ranked amongst the ten least peaceful countries, and Ukraine had the largest deterioration of any country in the 2023 GPI. In the same year, the global impact of violence on the economy was 17 percent, which was equivalent to 10.9% of global GDP. Besides, the brutal conflict in Tigray started in November. 2020 claimed more than half a million lives lost and displaced nearly 3 million people, along with widespread human rights violations and sexual violence has left deep damage on the population. The displaced people are still unable to return home because the western, southern and Eastern parts of Tigray are occupied by Eritrean and Amhara forces, despite the Pretoria Agreement. Currently, armed conflicts in Amhara in the Oromya regions are intensified, and human rights violations are being reported in both regions. Meanwhile, protests have been held by war-injured TDF members, IDPs and teachers in the Tigray region. Hence, the general objective of this project is to explore the challenges of peace-building processes in the border woredas of the Eastern Zone of the Tigray Region. Methodologically, the project will employ exploratory qualitative research designs to gather and analyze qualitative data. A purposive sampling technique will be applied to gather pertinent information from the key stakeholders. Open-ended interview questions will be prepared to gather relevant information about the challenges and perceptions of peacebuilding in the study area. Data will be analyzed using qualitative methods such as content analysis, narrative analysis and phenomenological analysis to deeply investigate the challenges of peace-building in the study woredas. Findings of this research project will be employed for program intervention to promote sustainable peace in the study area.

Keywords: peace building, conflcit and violence, political instability, insecurity

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Authors: Mahfouz Saeed

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Cu₂(ZnSn)(S)₄ (CTZS) offers potential advantages over CuInGaSe₂ (CIGS) as solar thin film because to its higher band gap. Preparing such photovoltaic materials by electrochemical techniques is particularly attractive due to the lower processing cost and the high throughput of such techniques. Several recent publications report CTZS electroplating; however, the electrochemical process still facing serious challenges such as a sulfur atomic ration which is about 50% of the total alloy. We introduce in this work an improved electrolyte composition which enables the direct electrodeposition of CTZS from a single bath. The electrolyte is significantly more dilute in comparison to common baths described in the literature. The bath composition we introduce is: 0.0032 M CuSO₄, 0.0021 M ZnSO₄, 0.0303 M SnCl₂, 0.0038 M Na₂S₂O₃, and 0.3 mM Na₂S₂O3. PHydrion is applied to buffer the electrolyte to pH=2, and 0.7 M LiCl is applied as supporting electrolyte. Electrochemical process was carried at a rotating disk electrode which provides quantitative characterization of the flow (room temperature). Comprehensive electrochemical behavior study at different electrode rotation rates are provided. The effects of agitation on atomic composition of the deposit and its adhesion to the molybdenum back contact are discussed. The post treatment annealing was conducted under sulfur atmosphere with no need for metals addition from the gas phase during annealing. The potential which produced the desired atomic ratio of CTZS at -0.82 V/NHE. Smooth deposit, with uniform composition across the sample surface and depth was obtained at 500 rpm rotation speed. Final sulfur atomic ratio was adjusted to 50.2% in order to have the desired atomic ration. The final composition was investigated using Energy-dispersive X-ray spectroscopy technique (EDS). XRD technique used to analyze CTZS crystallography and thickness. Complete and functional CTZS PV devices were fabricated by depositing all the required layers in the correct order and the desired optical properties. Acknowledgments: Case Western Reserve University for the technical help and for using their instruments.

Keywords: photovoltaic, CTZS, thin film, electrochemical

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Authors: F. A. Thomas, M. Schrafl-Altermatt, R. Treier, S. Kaufmann

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Stroke is the main cause of adult disability. Especially upper limb function is affected in most patients. Recently, cooperative hand movements have been shown to be a promising type of upper limb training in stroke rehabilitation. In these movements, which are frequently found in activities of daily living (e.g. opening a bottle, winding up a blind), the force of one upper limb has to be equally counteracted by the other limb to successfully accomplish a task. The use of standardized and reliable clinical assessments is essential to evaluate the efficacy of therapy and the functional outcome of a patient. Many assessments for upper limb function or impairment are available. However, the evaluation of cooperative hand movement tasks are rarely included in those. Thus, the aim of this study was (i) to develop a novel clinical assessment (CASA - Cooperative Activity Stroke Assessment) for the evaluation of patients’ capacity to perform cooperative hand movements and (ii) to test its inter- and interrater reliability. Furthermore, CASA scores were compared to current gold standard assessments for upper extremity in stroke patients (i.e. Fugl-Meyer Assessment, Box & Blocks Test). The CASA consists of five cooperative activities of daily living including (1) opening a jar, (2) opening a bottle, (3) open and closing of a zip, (4) unscrew a nut and (5) opening a clipbox. Here, the goal is to accomplish the tasks as fast as possible. In addition to the quantitative rating (i.e. time) which is converted to a 7-point scale, also the quality of the movement is rated in a 4-point scale. To test the reliability of CASA, fifteen stroke subjects were tested within a week twice by the same two raters. Intra-and interrater reliability was calculated using the intraclass correlation coefficient (ICC) for total CASA score and single items. Furthermore, Pearson-correlation was used to compare the CASA scores to the scores of Fugl-Meyer upper limb assessment and the box and blocks test, which were assessed in every patient additionally to the CASA. ICC scores of the total CASA score indicated an excellent- and single items established a good to excellent inter- and interrater reliability. Furthermore, the CASA score was significantly correlated to the Fugl-Meyer and Box & Blocks score. The CASA provides a reliable assessment for cooperative hand movements which are crucial for many activities of daily living. Due to its non-costly setup, easy and fast implementation, we suggest it to be well suitable for clinical application. In conclusion, the CASA is a useful tool in assessing the functional status and therapy related recovery in cooperative hand movement capacity in stroke patients.

Keywords: activitites of daily living, clinical assessment, cooperative hand movements, reliability, stroke

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Authors: Naziha Mokadem, Rainier Dennis, Ingrid Dennis

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In South Africa, Karst aquifers are receiving greater attention since they provide large supplies of water which is used for domestic and agricultural purposes as well as for industry. Accordingly, a better insight into the origin of water mineralization and the geochemical processes controlling the recharge of the aquifer is crucial. Analyses of geochemical and environmental isotopes could lead to relevant information regarding karstification and infiltration processes, groundwater chemistry and isotopy. A study was conducted in a typical karst landscape of Wonderfonteinspruit catchment, also known as Wonderfonteinspruit Valley in North-western -South Africa. Furthermore, fifty-two samples were collected from (35 boreholes, 5 surface waters, 4 Dams, 4 springs, 1 canal, 2 pipelines, 1 cave) within the study area for hydrochemistry and 2H and 18O analysis. The determination of the anions (Cl-, SO42-, NO2, NO3-) were performed using Metrohm ion chromatography, model: 761 compact IC, with a precision of ± 0.001 mg/l. While, the cations (Na+, Mg2+, K+, Ca2+) were determined using Metrohm ion chromatography, Model: ICP-MS 7500 series. The alkalinity (Alk) was determined by pH meter with volumetric titration using HCL to pH 4.5; 4.2; and 8.2. In addition, 18O and 2H relative to the Vienna-Standard Mean Ocean Water (RVSMOW), were determined by picarro L2130-I Isotopic H2O (Cavity Ringdown laser spectrometer, Picarro Ltd). The hydrochemical analysis of Wonderfonteinspruit groundwater showed a dominance of the cations Ca-Mg and the anion HCO3. Piper diagram shows that the groundwater sample of study area is characterized by four hydrochemical facies: Two main groups: (1) Ca–Mg–Cl–SO4; (2) Ca–Mg–HCO3 and two minor groups: (3) Ca–Mg–Cl; (4) Na–K–HCO3. The majority of boreholes of Malmani (Transvaal Supergroup) aquifer are plotted in Ca–Mg–HCO3.Oxygen-18 (18O‰SMOW) and deuterium (D‰SMOW) isotopic data indicate that the aquifer’s recharge is influenced by two phenomena; precipitation rates for most of the samples and river flow (Wonderfonteinspruit, Middelvieinspruit, Renfonteinspruit) for some samples.

Keywords: South Africa, Wonderfonteinspruit Valley, isotopic, hydrochemical, carbonate aquifers

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Authors: Joy Cao, Min Zhou

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Purpose: Acute Type A aortic dissection is a well-known cause of extremely high mortality rate. A highly accurate and cost-effective non-invasive predictor is critically needed so that the patient can be treated at earlier stage. Although various CFD approaches have been tried to establish some prediction frameworks, they are sensitive to uncertainty in both image segmentation and boundary conditions. Tedious pre-processing and demanding calibration procedures requirement further compound the issue, thus hampering their clinical applicability. Using the latest physics informed deep learning methods to establish an accurate and cost-effective predictor framework are amongst the main goals for a better Type A aortic dissection treatment. Methods: Via training a novel physics-informed deep residual network, with non-invasive 4D MRI displacement vectors as inputs, the trained model can cost-effectively calculate all these biomarkers: aortic blood pressure, WSS, and OSI, which are used to predict potential type A aortic dissection to avoid the high mortality events down the road. Results: The proposed deep learning method has been successfully trained and tested with both synthetic 3D aneurysm dataset and a clinical dataset in the aortic dissection context using Google colab environment. In both cases, the model has generated aortic blood pressure, WSS, and OSI results matching the expected patient’s health status. Conclusion: The proposed novel physics-informed deep residual network shows great potential to create a cost-effective, non-invasive predictor framework. Additional physics-based de-noising algorithm will be added to make the model more robust to clinical data noises. Further studies will be conducted in collaboration with big institutions such as Cleveland Clinic with more clinical samples to further improve the model’s clinical applicability.

Keywords: type-a aortic dissection, deep residual networks, blood flow modeling, data-driven modeling, non-invasive diagnostics, deep learning, artificial intelligence.

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Authors: Kenichi Yamahara, Makiko Ohshima, Shunsuke Ohnishi, Hidetoshi Tsuda, Akihiko Taguchi, Toshihiro Soma, Hiroyasu Ogawa, Jun Yoshimatsu, Tomoaki Ikeda

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We have previously reported the therapeutic potential of rat fetal membrane(FM)-derived mesenchymal stem cells (MSCs) using various rat models including hindlimb ischemia, autoimmune myocarditis, glomerulonephritis, renal ischemia-reperfusion injury, and myocardial infarction. In this study, 1) we isolated and characterized MSCs from human amnion and chorion; 2) we examined their differences in the expression profile of growth factors and cytokines; and 3) we investigated the therapeutic potential and difference of these MSCs using murine hindlimb ischemia and acute graft-versus-host disease (GVHD) models. Isolated MSCs from both amnion and chorion layers of FM showed similar morphological appearance, multipotency, and cell-surface antigen expression. Conditioned media obtained from amnion- and chorion-derived MSCs inhibited cell death caused by serum starvation or hypoxia in endothelial cells and cardiomyocytes. Amnion and chorion MSCs secreted significant amounts of angiogenic factors including HGF, IGF-1, VEGF, and bFGF, although differences in the cellular expression profile of these soluble factors were observed. Transplantation of human amnion or chorion MSCs significantly increased blood flow and capillary density in a murine hindlimb ischemia model. In addition, compared to human chorion MSCs, human amnion MSCs markedly reduced T-lymphocyte proliferation with the enhanced secretion of PGE2, and improved the pathological situation of a mouse model of GVHD disease. Our results highlight that human amnionand chorion-derived MSCs, which showed differences in their soluble factor secretion and angiogenic/immuno-suppressive function, could be ideal cell sources for regenerative medicine.

Keywords: amnion, chorion, fetal membrane, mesenchymal stem cells

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Authors: Peter Smolianov, Steven Dion, Christopher Schoen, Jaclyn Norberg, Nicholas Stone, Soufiane Rafi

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This study assessed the micro-level elements of track and field development in the US against a model for integrating high-performance sport with mass participation. This investigation is important for the country’s international sport performance, which declined relative to other countries and wellbeing, which in its turn deteriorated as over half of the US population became overweight. A questionnaire was designed for the following elements of the model: talent identification and development as well as advanced athlete support. Survey questions were validated by 12 experts, including academics, executives from sport governing bodies, coaches, and administrators. To determine the areas for improvement, the questionnaires were completed by 102 US track and field coaches representing the country’s regions and coaching levels. Possible advancements were further identified through semi-structured discussions with 10 US track and field administrators. The study found that talent search and development is a critically important area for improvement: 49 percent of respondents had overall negative perceptions, and only 16 percent were positive regarding these US track and field practices. Both quantitative survey results and open responses revealed that the key reason for the inadequate athlete development was a shortage of well-educated and properly paid coaches: 77 percent of respondents indicated that coach expertise is never or rarely high across all participant ages and levels. More than 40 percent of the respondents were uncertain of or not familiar with world’s best talent identification and development practices, particularly methods of introducing children to track and field from outside the sport’s participation base. Millions more could be attracted to the sport by adopting best international practices. First, physical education should be offered a minimum three times a week in all school grades, and track and field together with other healthy sports, should be taught at school to all children. Second, multi-sport events, including track and field disciplines, should be organized for everyone within and among all schools, cities and regions. Three, Australian and Eastern European methods of talent search at schools should be utilized and tailored to the US conditions. Four, comprehensive long term athlete development guidelines should be used for the advancement of the American Development Model, particularly track and field tests and guidelines as part of both school education and high-performance athlete development for every age group from six to over 70 years old. These world’s best practices are to improve the country’s international performance while increasing national sport participation and positively influencing public health.

Keywords: high performance, mass participation, sport development, track and field, USA

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Authors: Rodrigo Antunes, Olga Borisevich, David Demange

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In future nuclear fusion reactors, tritium self-sufficiency will be ensured by tritium (3H) production via reactions between the fusion neutrons and lithium. To favor tritium breeding, a neutron multiplier must also be used. Both tritium breeder and neutron multiplier will be placed in the so-called Breeding Blanket (BB). For the European Helium-Cooled Pebble Bed (HCPB) BB concept, the tritium production and neutron multiplication will be ensured by neutron bombardment of Li4SiO4 and Be pebbles, respectively. The produced tritium is extracted from the pebbles by purging them with large flows of He (~ 104 Nm3h-1), doped with small amounts of H2 (~ 0.1 vol%) to promote tritium extraction via isotopic exchange (producing HT). Due to the presence of oxygen in the pebbles, production of tritiated water is unavoidable. Therefore, the purging gas downstream of the BB will be composed by Q2/Q2O/He (Q = 1H, 2H, 3H), with Q2/Q2O down to ppm levels, which must be further processed for tritium recovery. A two-stage continuous approach, where zeolite membranes (ZMs) are followed by a catalytic membrane reactor (CMR), has been recently proposed to fulfil this task. The tritium recovery from Q2/Q2O/He is ensured by the CMR, that requires a reduction of the gas flow coming from the BB and a pre-concentration of Q2 and Q2O to be efficient. For this reason, and to keep this stage with reasonable dimensions, ZMs are required upfront to reduce as much as possible the He flows and concentrate the Q2/Q2O species. Therefore, experimental activities have been carried out at the Tritium Laboratory Karlsruhe (TLK) to test the separation performances of different zeolite membranes for H2/H2O/He. First experiments have been performed with binary mixtures of H2/He and H2O/He with commercial MFI-ZSM5 and NaA zeolite-type membranes. Only the MFI-ZSM5 demonstrated selectivity towards H2, with a separation factor around 1.5, and H2 permeances around 0.72 µmolm-2s-1Pa-1, rather independent for feed concentrations in the range 0.1 vol%-10 vol% H2/He. The experiments with H2O/He have demonstrated that the separation factor towards H2O is highly dependent on the feed concentration and temperature. For instance, at 0.2 vol% H2O/He the separation factor with NaA is below 2 and around 1000 at 5 vol% H2O/He, at 30°C. Overall, both membranes demonstrated complementary results at equivalent temperatures. In fact, at low feed concentrations ( ≤ 1 vol% H2O/He) MFI-ZSM5 separates better than NaA, whereas the latter has higher separation factors for higher inlet water content ( ≥ 5 vol% H2O/He). In this contribution, the results obtained with both MFI-ZSM5 and NaA membranes for H2/He and H2O/H2 mixtures at different concentrations and temperatures are compared and discussed.

Keywords: nuclear fusion, gas separation, tritium processes, zeolite membranes

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Authors: Gabriela Rivadeneyra-Romero, Claudia del C. Gutierrez Torres, Sergio A. Martinez-Delgadillo, Victor X. Mendoza-Escamilla, Alejandro Alonzo-Garcia

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Ultrasonic degradation is currently being used in sonochemical reactors to degrade pollutant compounds from aqueous media, as emerging contaminants (e.g. pharmaceuticals, drugs and personal care products.) because they can produce possible ecological impacts on the environment. For this reason, it is important to develop appropriate water and wastewater treatments able to reduce pollution and increase reuse. Pollutants such as textile dyes, aromatic and phenolic compounds, cholorobenzene, bisphenol-A and carboxylic acid and other organic pollutants, can be removed from wastewaters by sonochemical oxidation. The effect on the removal of pollutants depends on the type of the ultrasonic frequency used; however, not much studies have been done related to the behavior of the fluid into the sonoreactors operated at different ultrasonic frequencies. Based on the above, it is necessary to study the hydrodynamic behavior of the liquid generated by the ultrasonic irradiation to design efficient sonoreactors to reduce treatment times and costs. In this work, it was studied the hydrodynamic behavior of the fluid in sonochemical reactors at different frequencies (250 kHz, 500 kHz and 1000 kHz). The performances of the sonoreactors at those frequencies were simulated using computational fluid dynamics (CFD). Due to there is great sound speed gradient between piezoelectric and fluid, k-e models were used. Piezoelectric was defined as a vibration surface, to evaluate the different frequencies effect on the fluid into sonochemical reactor. Structured hexahedral cells were used to mesh the computational liquid domain, and fine triangular cells were used to mesh the piezoelectric transducers. Unsteady state conditions were used in the solver. Estimation of the dissipation rate, flow field velocities, Reynolds stress and turbulent quantities were evaluated by CFD and 2D-PIV measurements. Test results show that there is no necessary correlation between an increase of the ultrasonic frequency and the pollutant degradation, moreover, the reactor geometry and power density are important factors that should be considered in the sonochemical reactor design.

Keywords: CFD, reactor, ultrasound, wastewater

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Authors: J. Tirano, H. Zea, C. Luhrs

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Photocatalysis has established as viable option in the development of processes for the treatment of pollutants and clean energy production. This option is based on the ability of semiconductors to generate an electron flow by means of the interaction with solar radiation. Owing to its electronic structure, TiO₂ is the most frequently used semiconductors in photocatalysis, although it has a high recombination of photogenerated charges and low solar energy absorption. An alternative to reduce these limitations is the use of nanostructured morphologies which can be produced during the synthesis of TiO₂ nanotubes (TNTs). Therefore, if possible to produce vertically oriented nanostructures it will be possible to generate a greater contact area with electrolyte and better charge transfer. At present, however, the development of these innovative structures still presents an important challenge for the development of competitive photoelectrochemical devices. This research focuses on established correlations between synthesis variables and 1D nanostructure morphology which has a direct effect on the photocatalytic performance. TNTs with controlled morphology were synthesized by two-step potentiostatic anodization of titanium foil. The anodization was carried out at room temperature in an electrolyte composed of ammonium fluoride, deionized water and ethylene glycol. Consequent thermal annealing of as-prepared TNTs was conducted in the air between 450 °C-550 °C. Morphology and crystalline phase of the TNTs were carried out by SEM, EDS and XRD analysis. As results, the synthesis conditions were established to produce nanostructures with specific morphological characteristics. Anatase was the predominant phase of TNTs after thermal treatment. Nanotubes with 10 μm in length, 40 nm in pore diameter and a surface-volume ratio of 50 are important in photoelectrochemical applications based on TiO₂ due to their 1D characteristics, high surface-volume ratio, reduced radial dimensions and high oxide/electrolyte interface. Finally, this knowledge can be used to improve the photocatalytic activity of TNTs by making additional surface modifications with dopants that improve their efficiency.

Keywords: electrochemical anodization, morphology, self-organized nanotubes, TiO₂ nanotubes

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Authors: Yasemin Akar, Jan G. Wissink, Herlina Herlina

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The effect of various levels of contamination on the interfacial air–water gas transfer velocity is studied by Direct Numerical Simulation (DNS). The interfacial gas transfer is driven by isotropic turbulence, introduced at the bottom of the computational domain, diffusing upwards. The isotropic turbulence is generated in a separate, concurrently running the large-eddy simulation (LES). The flow fields in the main DNS and the LES are solved using fourth-order discretisations of convection and diffusion. To solve the transport of dissolved gases in water, a fifth-order-accurate WENO scheme is used for scalar convection combined with a fourth-order central discretisation for scalar diffusion. The damping effect of the surfactant contamination on the near surface (horizontal) velocities in the DNS is modelled using horizontal gradients of the surfactant concentration. An important parameter in this model, which corresponds to the level of contamination, is ReMa⁄We, where Re is the Reynolds number, Ma is the Marangoni number, and We is the Weber number. It was previously found that even small levels of contamination (ReMa⁄We small) lead to a significant drop in the interfacial gas transfer velocity KL. It is known that KL depends on both the Schmidt number Sc (ratio of the kinematic viscosity and the gas diffusivity in water) and the surface divergence β, i.e. K_L∝√(β⁄Sc). Previously it has been shown that this relation works well for surfaces with low to moderate contamination. However, it will break down for β close to zero. To study the validity of this dependence in the presence of surface contamination, simulations were carried out for ReMa⁄We=0,0.12,0.6,1.2,6,30 and Sc = 2, 4, 8, 16, 32. First, it will be shown that the scaling of KL with Sc remains valid also for larger ReMa⁄We. This is an important result that indicates that - for various levels of contamination - the numerical results obtained at low Schmidt numbers are also valid for significantly higher and more realistic Sc. Subsequently, it will be shown that - with increasing levels of ReMa⁄We - the dependency of KL on β begins to break down as the increased damping of near surface fluctuations results in an increased damping of β. Especially for large levels of contamination, this damping is so severe that KL is found to be underestimated significantly.

Keywords: contamination, gas transfer, surfactants, turbulence

Procedia PDF Downloads 285

Authors: Markus Bredel, Sindhu Nair, Hoa Q. Trummell, Rajani Rajbhandari, Christopher D. Willey, Lewis Z. Shi, Zhuo Zhang, William J. Placzek, James A. Bonner

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Purpose: EGFR-targeted monoclonal antibodies (mAbs) provide clinical benefit in some patients with H&N squamous cell carcinoma (HNSCC), but others progress with minimal response. Missense mutations in the EGFR ectodomain (ECD) can be acquired under mAb therapy by mimicking the effect of large deletions on receptor untethering and activation. Little is known about the contribution of EGFR ECD mutations to EGFR activation and anti-EGFR response in HNSCC. Methods: We selected patient-derived HNSCC cells (UM-SCC-1) for resistance to mAb Cetuximab (CTX) by repeated, stepwise exposure to mimic what may occur clinically and identified two concurrent EGFR ECD mutations (UM-SCC-1R). We examined the competence of the mutants to bind EGF ligand or CTX. We assessed the potential impact of the mutations through visual analysis of space-filling models of the native sidechains in the original structures vs. their respective side-chain mutations. We performed CRISPR in combination with site-directed mutagenesis to test for the effect of the mutants on ligand-independent EGFR activation and sorting. We determined the effects on receptor internalization, endocytosis, downstream signaling, and radiation sensitivity. Results: UM-SCC-1R cells carried two non-synonymous missense mutations (G33S and N56K) mapping to domain I in or near the EGF binding pocket of the EGFR ECD. Structural modeling predicted that these mutants restrict the adoption of a tethered, inactive EGFR conformation while not permitting association of EGFR with the EGF ligand or CTX. Binding studies confirmed that the mutant, untethered receptor displayed a reduced affinity for both EGF and CTX but demonstrated sustained activation and presence at the cell surface with diminished internalization and sorting for endosomal degradation. Single and double-mutant models demonstrated that the G33S mutant is dominant over the N56K mutant in its effect on EGFR activation and EGF binding. CTX-resistant UM-SCC-1R cells demonstrated cross-resistance to mAb Panitumuab but, paradoxically, remained sensitive to the reversible receptor tyrosine kinase inhibitor Erlotinib. Conclusions: HNSCC cells can select for EGFR ECD mutations under EGFR mAb exposure that converge to trap the receptor in an open, constitutively activated state. These mutants impede the receptor’s competence to bind mAbs and EGF ligand and alter its endosomal trafficking, possibly explaining certain cases of clinical mAb and radiation resistance.

Keywords: head and neck cancer, EGFR mutation, resistance, cetuximab

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Authors: Marine Agogue, Beatrice Parguel, Emilie Canet

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Defined as receptive attention to and awareness of present events and experience, mindfulness has grown in popularity over the past 30 years to become a trendy buzzword in business media, which regularly reports on its organizational benefits. Mindfulness would enhance or impede creative thinking depending on the type of meditation. Specifically, focused-attention meditation (focusing attention on one object instead of being open to perceive and observe any sensation or thought) would not be or negatively correlated to creativity. This research explores whether mood, in its two dimensions (i.e., hedonic tone, activation level), could mediate this potentially negative effect. The rationale is that focused-attention meditation is likely to improve hedonic tone but, in the meantime, damage activation level, resulting in opposite effects on creativity through the mediation effect of creative self-efficacy, i.e., the belief that one can perform successfully in an ideation setting. To test this conceptual model, a survey was administered to 97 subjects (53% women, mean age: 25 years), randomly assigned to three conditions (a 10-minute focused-attention meditation session vs. a 10-minute psychometric tests session vs. a control condition) and asked to participate in the egg creative task. Creativity was measured in terms of fluency, expansivity, and originality, the other variables using existing scales: hedonic tone (e.g., joyful, happy), activation level (e.g., passive, sluggish), creative self-efficacy (e.g., ‘I felt confident in my ability to do the task effectively’) and self-perceived creativity (e.g., ‘I have lots of original ideas’). The chains of mediation were tested using PROCESS macro (model 6) and controlled for subjects’ gender, age, and self-perceived creativity. Comparing the mindfulness and the control conditions, no difference appeared in terms of creativity, nor any mediation chain by hedonic tone. However, subjects who participated in the meditation session felt less active than those in the control condition, which decreased their creative self-efficacy, and creativity (whatever the indicator considered). Comparing the mindfulness and the psychometric tests conditions, analyses showed that creativity was higher in the psychometric tests condition. As previously, no mediation chain appeared by hedonic tone. However, subjects who participated in the meditation session felt less active than those in the psychometric tests condition, which decreased their creative self-efficacy, and creativity. These findings confirm that focused-attention meditation does not enhance creativity. They demonstrate an emotional underlying mechanism based on activation level and suggest that both positive and active mood states have the potential to enhance creativity through creative self-efficacy. In the end, they should discourage organizations from trying to nudge creativity using mindfulness ad hoc devices.

Keywords: creativity, mindfulness, creative self-efficacy, experiment

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Authors: Tarek Duzan, Walid Esayed

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Fluid flow in porous media is attributed fundamentally to parameters that are controlled by depositional and post-depositional environments. After deposition, digenetic events can act negatively on the reservoir and reduce the effective porosity, thereby making the rock less permeable. Therefore, exploiting hydrocarbons from such resources requires partially altering the rock properties to improve the long-term production rate and enhance the recovery efficiency. In this study, we try to address, firstly, the phenomena of permeability reduction in tight sandstone reservoirs and illustrate the implemented procedures to investigate the problem roots; finally, benchmark the candidate solutions at the field scale and recommend the mitigation strategy for the field development plan. During the study, two investigations have been considered: subsurface analysis using ( PLT ) and Laboratory tests for four candidate wells of the interested reservoir. Based on the above investigations, it was obvious that the Production logging tool (PLT) has shown areas of contribution in the reservoir, which is considered very limited, considering the total reservoir thickness. Also, Alcohol treatment was the first choice to go with for the AA9 well. The well productivity has been relatively restored but not to its initial productivity. Furthermore, Alcohol treatment in the lab was effective and restored permeability in some plugs by 98%, but operationally, the challenge would be the ability to distribute enough alcohol in a wellbore to attain the sweep Efficiency obtained within a laboratory core plug. However, the Second solution, which is based on fracking wells, has shown excellent results, especially for those wells that suffered a high drop in oil production. It is suggested to frac and pack the wells that are already damaged in the Waha field to mitigate the damage and restore productivity back as much as possible. In addition, Critical fluid velocity and its effect on fine sand migration in the reservoir have to be well studied on core samples, and therefore, suitable pressure drawdown will be applied in the reservoir to limit fine sand migration.

Keywords: alcohol treatment, post-depositional environments, permeability, tight sandstone

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Authors: James Rigor Camacho, Wansu Lim

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Over the last few years, the development of new wearable and processing technologies has accelerated in order to harness physiological data such as electroencephalograms (EEGs) for EEG-based applications. EEG has been demonstrated to be a source of emotion recognition signals with the highest classification accuracy among physiological signals. However, when emotion recognition systems are used for real-time classification, the training unit is frequently left to run offline or in the cloud rather than working locally on the edge. That strategy has hampered research, and the full potential of using an edge AI device has yet to be realized. Edge AI devices are computers with high performance that can process complex algorithms. It is capable of collecting, processing, and storing data on its own. It can also analyze and apply complicated algorithms like localization, detection, and recognition on a real-time application, making it a powerful embedded device. The NVIDIA Jetson series, specifically the Jetson Nano device, was used in the implementation. The cEEGrid, which is integrated to the open-source brain computer-interface platform (OpenBCI), is used to collect EEG signals. An EEG-based real-time emotion recognition system on Edge AI is proposed in this paper. To perform graphical spectrogram categorization of EEG signals and to predict emotional states based on input data properties, machine learning-based classifiers were used. Until the emotional state was identified, the EEG signals were analyzed using the K-Nearest Neighbor (KNN) technique, which is a supervised learning system. In EEG signal processing, after each EEG signal has been received in real-time and translated from time to frequency domain, the Fast Fourier Transform (FFT) technique is utilized to observe the frequency bands in each EEG signal. To appropriately show the variance of each EEG frequency band, power density, standard deviation, and mean are calculated and employed. The next stage is to identify the features that have been chosen to predict emotion in EEG data using the K-Nearest Neighbors (KNN) technique. Arousal and valence datasets are used to train the parameters defined by the KNN technique.Because classification and recognition of specific classes, as well as emotion prediction, are conducted both online and locally on the edge, the KNN technique increased the performance of the emotion recognition system on the NVIDIA Jetson Nano. Finally, this implementation aims to bridge the research gap on cost-effective and efficient real-time emotion recognition using a resource constrained hardware device, like the NVIDIA Jetson Nano. On the cutting edge of AI, EEG-based emotion identification can be employed in applications that can rapidly expand the research and implementation industry's use.

Keywords: edge AI device, EEG, emotion recognition system, supervised learning algorithm, sensors

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Authors: Igone Guerra, Xabier Barandiaran

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The deep crisis (economic, social and cultural) in which Europe and Gipuzkoa, in the Basque Country (Spain), have been immersed in since 2008 forces governments to face a necessary transformation. These challenges demand different solutions and answers to meet the needs of the citizens. Adapting to continuous and sometimes abrupt changes in the social and political landscape requires an undeniable will to reinvent the way in which governments practice politics. This reinvention of government should help us build different organizations that, first, develop challenging public services, second, respond effectively to the needs of the citizens, and third, manage scarce resources, ultimately offering a contemporary concept of public value. In this context, the Etorkizuna Eraikiz initiative was designed to face the future challenges of the territory in a collaborative way. The aim of the initiative is to promote an alternative form of governance to generate common good and greater public value. In Etorkizuna Eraikiz democratic values, such as collaboration, participation, and accountability are prominent. This government approach is based on several features such as the creation of relational spaces to design and deliberate about the public politics or the promotion of a team-working approach, breaking down the silos between and within organizations, as an exercise in defining a shared vision regarding the Future of the Territory. A future in which the citizens are becoming actors in the problem-solving process and in the construction of a culture of participation and collective learning. In this paper, the Etorkizuna Eraikiz initiative will be presented (vision and methodology) as a model of a local approach to public policy innovation resulting in a way of governance that is more open and collaborative. Based on this case study, this paper explores the way in which collaborative governance leads to better decisions, better leadership, and better citizenry. Finally, the paper also describes some preliminary findings of this local approach, such as the level of knowledge of the citizenry about the projects promoted within Etorkizuna Eraikiz as well as the link between the challenges of the territory, as identified by the citizenry, and the political agenda promoted by the provincial government. Regarding the former, the Survey on the socio-political situation of Gipuzkoa showed that 27.9% of the respondents confirmed that they knew about the projects promoted within the initiative and gave it a mark of 5.71. In connection with the latter, over the last three years, 65 millions of euros have been allocated for a total of 73 projects that have covered socio-economic and political challenges such as aging, climate change, mobility, participation in democratic life, and so on. This governance approach of Etorkizuna Eraikiz has allowed the local government to match the needs of citizens to the political agenda fostering in this way a shared vision about the public value.

Keywords: collaborative governance, citizen participation, public good, social listening, public innovation

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Authors: Elizaveta Petelina, Anton Sizo

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Environmental remediation projects deal with a wide spectrum of data, including data collected during site assessment, execution of remediation activities, and environmental monitoring. Therefore, an appropriate data management is required as a key factor for well-grounded decision making. The Environmental Data Management System (EDMS) was developed to address all necessary data management aspects, including efficient data handling and data interoperability, access to historical and current data, spatial and temporal analysis, 2D and 3D data visualization, mapping, and data sharing. The system focuses on support of well-grounded decision making in relation to required mitigation measures and assessment of remediation success. The EDMS is a combination of enterprise and desktop level data management and Geographic Information System (GIS) tools assembled to assist to environmental remediation, project planning, and evaluation, and environmental monitoring of mine sites. EDMS consists of seven main components: a Geodatabase that contains spatial database to store and query spatially distributed data; a GIS and Web GIS component that combines desktop and server-based GIS solutions; a Field Data Collection component that contains tools for field work; a Quality Assurance (QA)/Quality Control (QC) component that combines operational procedures for QA and measures for QC; Data Import and Export component that includes tools and templates to support project data flow; a Lab Data component that provides connection between EDMS and laboratory information management systems; and a Reporting component that includes server-based services for real-time report generation. The EDMS has been successfully implemented for the Project CLEANS (Clean-up of Abandoned Northern Mines). Project CLEANS is a multi-year, multimillion-dollar project aimed at assessing and reclaiming 37 uranium mine sites in northern Saskatchewan, Canada. The EDMS has effectively facilitated integrated decision-making for CLEANS project managers and transparency amongst stakeholders.

Keywords: data management, environmental remediation, geographic information system, GIS, decision making

Procedia PDF Downloads 139

Authors: Elisa Menicucci, Guido Paolucci

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Purpose: The aim of this paper is to investigate the factors influencing profitability in the Italian hospitality industry during the period 2008-2016. Design/methodology/approach: This study examines the profitability and its determinants using a sample of 2366 Italian hotel firms. First, we use a multidimensional measure of profitability including attributes as return on equity, return on assets and occupancy rate. Second, we examine variables that are potentially related with performance and we sort these into five categories: market variables, business model, ownership structure, management education and control variables. Findings: The results show that financial crisis, business model and ownership structure influence profitability of hotel firms. Specific factors such as the internationalization, location, firm’s declaring accommodation as their primary activity and chain affiliation are associated positively with profitability. We also find that larger hotel firms have higher performance rankings, while hotels with higher operating cash flow volatility, greater sales volatility and a higher occurrence of losses have lower profitability. Research limitations/implications: Findings suggest the importance of considering firm specific factors to evaluate the profitability of a hotel firm. Results also provide evidence for academics to critically evaluate factors that would ensure profitability of hotels in developed countries such as Italy. Practical implications: This investigation offers valuable information and strategic implications for government, tourism policymakers, tourist hotel owners, hoteliers and tourism managers in their decision-making. Originality/value: This paper provides interesting insights into the characteristics and practices of profitable hotels in Italy. Few econometric studies empirically explored the determinants of performance in the European hospitality field so far. Therefore, this paper tries to close an important gap in the existing literature improving the understanding of profitability in the Italian hospitality industry.

Keywords: hotel firms, profitability, determinants, Italian hospitality industry

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Authors: Zhaopeng Zhu, Xianzhi Song, Gensheng Li

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Transports of solid particles through the drill pipe, drill string-hole annulus and hydraulically generated fractures are important dynamic processes encountered in oil and gas well drilling and completion operations. Different from particle transport in infinite space, the transports of cuttings, proppants and formation sand are hindered by a finite boundary. Therefore, an accurate description of the particle transport behavior under the bounded wall conditions encountered in drilling and hydraulic fracturing operations is needed to improve drilling safety and efficiency. In this study, the particle settling experiments were carried out to investigate the particle settling behavior in the pipe, annulus and between the parallel plates filled with power-law fluids. Experimental conditions simulated the particle Reynolds number ranges of 0.01-123.87, the dimensionless diameter ranges of 0.20-0.80 and the fluid flow behavior index ranges of 0.48-0.69. Firstly, the wall effect of the annulus is revealed by analyzing the settling process of the particles in the annular geometry with variable inner pipe diameter. Then, the geometric continuity among the pipe, annulus and parallel plates was determined by introducing the ratio of inner diameter to an outer diameter of the annulus. Further, a unified dimensionless diameter was defined to confirm the relationship between the three different geometry in terms of the wall effect. In addition, a dimensionless term independent from the settling velocity was introduced to establish a unified explicit settling velocity model applicable to pipes, annulus and fractures with a mean relative error of 8.71%. An example case study was provided to demonstrate the application of the unified model for predicting particle settling velocity. This paper is the first study of annulus wall effects based on the geometric continuity concept and the unified model presented here will provide theoretical guidance for improved hydraulic design of cuttings transport, proppant placement and sand management operations.

Keywords: wall effect, particle settling velocity, cuttings transport, proppant transport in fracture

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Authors: Teklay Gebrecherkos

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Background: Serological testing for SARS-CoV-2 plays an important role in epidemiological studies, in aiding the diagnosis of COVID-19 and assess vaccine responses. Little is known about the dynamics of SARS-CoV-2 serology in African settings. Here, we aimed to characterize the longitudinal antibody response profile to SARS-CoV-2 in Ethiopia. Methods: In this prospective study, a total of 102 PCR-confirmed COVID-19 patients were enrolled. We obtained 802 plasma samples collected serially. SARS-CoV-2 antibodies were determined using four lateral flow immune assays (LFIAs) and an electrochemiluminescent immunoassay. We determined longitudinal antibody response to SARS-CoV-2 as well as seroconversion dynamics. Results: Serological positivity rate ranged between 12%-91%, depending on timing after symptom onset. There was no difference in the positivity rate between severe and non-severe COVID-19 cases. The specificity ranged between 90%-97%. Agreement between different assays ranged between 84%-92%. The estimated positive predictive value (PPV) for IgM or IgG in a scenario with seroprevalence at 5% varies from 33% to 58%. Nonetheless, when the population seroprevalence increases to 25% and 50%, there is a corresponding increase in the estimated PPVs. The estimated negative-predictive value (NPV) in a low seroprevalence scenario (5%) is high (>99%). However, the estimated NPV in a high seroprevalence scenario (50%) for IgM or IgG is reduced significantly from 80% to 85%. Overall, 28/102 (27.5%) seroconverted by one or more assays tested within a median time of 11 (IQR: 9–15) days post symptom onset. The median seroconversion time among symptomatic cases tended to be shorter when compared to asymptomatic patients [9 (IQR: 6–11) vs. 15 (IQR: 13–21) days; p = 0.002]. Overall, seroconversion reached 100% 5.5 weeks after the onset of symptoms. Notably, of the remaining 74 COVID-19 patients included in the cohort, 64 (62.8%) were positive for antibodies at the time of enrollment, and 10 (9.8%) patients failed to mount a detectable antibody response by any of the assays tested during follow-up. Conclusions: Longitudinal assessment of antibody response in African COVID-19 patients revealed heterogeneous responses. This underscores the need for a comprehensive evaluation of serum assays before implementation. Factors associated with failure to seroconvert need further research.

Keywords: COVID-19, antibody, rapid diagnostic tests, ethiopia

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Authors: Lakmali Anthony, Madeline Gillies

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Background: Colorectal cancer (CRC) is usually managed with surgical resection. Many of the outcomes traditionally used to define successful operative management, such as resection margin, do not adequately reflect patients’ experience. Patient-reported outcomes (PRO), such as Health-Related Quality of life (HRQoL), provide a means by which the impact of surgery for cancer can be reported in a patient-centered way. HRQoL has previously been shown to be impacted by psychosocial, behavioral and disease-specific characteristics. This exploratory cross-sectional study aims to; (1) describe postoperative HRQoL in patients who underwent primary resection in a regional Australian hospital; (2) describe the prevalence of anxiety, depression and clinically significant fear of cancer recurrence (FCR) in this population; and (3) identify demographic, psychosocial, disease and treatment factors associated with poorer self-reported HRQoL. Methods: Consecutive patients who had resection of colorectal cancer in a single regional Australian hospital between 2015 and 2022 were eligible. Participants were asked to complete a survey instrument designed to assess HRQoL, as well as validated instruments that assess several other psychosocial PROs hypothesized to be associated with HRQoL; emotional distress, fear of cancer recurrence, social support, dispositional optimism, body image and spirituality. Demographic and disease-specific data were also collected via medical record review. Results: Forty-six patients completed the survey. Clinically significant levels of fear of recurrence as well as emotional distress, were present in this group. Many domains of HRQoL were significantly worse than an Australian reference population for CRC. Demographic and disease factors associated with poor HRQoL included smoking and ongoing adjuvant systemic therapy. The primary operation was not associated with HRQoL; however, the operative approach (laparoscopic vs. open) was associated with HRQoL for these patients. All psychosocial factors measured were associated with HRQoL, including cancer worry, emotional distress, body image and dispositional optimism. Conclusion: HRQoL is an important outcome in surgery for both research and clinical practice. This study provides an overview of the quality of life in a regional Australian population of postoperative colorectal cancer patients and the factors that affect it. Understanding HRQoL and awareness of patients particularly vulnerable to poor outcomes should be used to aid the informed consent and shared decision-making process between surgeon and patient.

Keywords: surgery, colorectal, cancer, PRO, HRQoL

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Authors: Haiying Zong, Yi Yuan, Pengcheng Li

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Cadmium (Cd), one of the toxic heavy metals, has high solubility and mobility in agricultural soils and is readily taken up by roots and transported to the vegetative and reproductive organs which can cause deleterious effects on crop yield and quality. Excess Cd in plants can interfere with many metabolic processes, such as photosynthesis, transpiration, respiration or nutrients homeostasis. Generally, the main methods to reduce Cd accumulation in plants are to decrease the concentration of Cd in the soil solution through reduction of Cd influx into the soil system, site selection, and management practices. However, these approaches can be very costly and consume a lot of energy Therefore, it is critical to develop effective approaches to reduce the Cd concentration in plants. It is proved that chitooligosaccharide (COS) can enhance the plant's tolerance to abiotic stress including drought stress, salinity stress, and toxic metal stress. However, so far little information is known about whether foliar application with COS modulates Cd-induced toxicity in plants. The metal detoxification processes of plants treated with COS also remain unclear. In this study, edible rape (Brassica rapa L.), one of the most widely consumed leafy vegetables, was selected as an experimental mode plant. The effect of foliar application with COS on reducing Cd accumulation in edible rape was investigated. Moreover, Cd subcellular distribution pattern in response to Cd stress in the rape plant sprayed with COS was further tested in order to explore the potential detoxification mechanisms in plants. The results demonstrated that spraying COS at different concentrations (25, 50,100 and 200 mg L-1) possess diverse functions including growth-promoting,chlorophyll contents-enhancing, malondialdehyde (MDA) level-decreasing in leaves, Cd2+ concentration-decreasingin shoots and roots of edible rape under Cd stress. In addition, it was found that COS can also dramatically improve superoxide dismutase (SOD) activity, catalase (CAT) activity and peroxidase (POX) activity of edible rape leaves. The relievingeffect of COS was related to theconcentration and COS with 50-100 mg L-1 displayed the best activity. Furtherly, theexperiments results exhibitedthat COS could decrease the proportion of Cd in the organelle fraction of leaves by 40.1% while enhance the proportion of Cd in the soluble fraction by 13.2% at the concentration of 50 mg L-1. The above results showed that COS may have thepotential to improve plant resistance to Cd via promoting antioxidant enzyme activities and altering Cd subcellular distribution. All the results described here open up a new way to study the protection role of COS in alleviating Cd tolerance and lay the foundation for future research about the detoxification mechanism at subcellular level.

Keywords: chitooligosaccharide, cadmium, edible rape (Brassica rapa L.), subcellular distribution

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Authors: Muhammad Awais Afzal, Lorena Tuchscherr De Hauschopp, Christian Hübner

Abstract:

Introduction: Autophagy is an evolutionarily conserved lysosome-dependent degradation pathway, which can be induced by extrinsic and intrinsic stressors in living systems to adapt to fluctuating environmental conditions. In the context of inflammatory stress, autophagy contributes to the elimination of invading pathogens, the regulation of innate and adaptive immune mechanisms, and regulation of inflammasome activity as well as tissue damage repair. Lysosomes can be recycled from autolysosomes by the process of autophagic lysosome reformation (ALR), which depends on the presence of several proteins including Spatacsin. Thus ALR contributes to the replenishment of lysosomes that are available for fusion with autophagosomes in situations of increased autophagic turnover, e.g., during bacterial infections, inflammatory stress or sepsis. Objectives: We aimed to assess whether ALR plays a role for cell survival in an in-vitro bacterial infection model. Methods: Mouse embryonic fibroblasts (MEFs) were isolated from wild-type mice and Spatacsin (Spg11-/-) knockout mice. Wild-type MEFs and Spg11-/- MEFs were infected with Staphylococcus aureus (multiplication of infection (MOI) used was 10). After 8 and 16 hours of infection, cell viability was assessed on BD flow cytometer through propidium iodide intake. Bacterial intake by cells was also calculated by plating cell lysates on blood agar plates. Results: in-vitro infection of MEFs with Staphylococcus aureus showed a marked decrease of cell viability in ALR deficient Spatacsin knockout (Spg11-/-) MEFs after 16 hours of infection as compared to wild-type MEFs (n=3 independent experiments; p < 0.0001) although no difference was observed for bacterial intake by both genotypes. Conclusion: Suggesting that ALR is important for the defense of invading pathogens e.g. S. aureus, we observed a marked increase of cell death in an in-vitro infection model in cells with compromised ALR.

Keywords: autophagy, autophagic lysosome reformation, bacterial infections, Staphylococcus aureus

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