Search results for: complex and dynamic systems
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 16503

Search results for: complex and dynamic systems

1863 Dual Metal Organic Framework Derived N-Doped Fe3C Nanocages Decorated with Ultrathin ZnIn2S4 Nanosheets for Efficient Photocatalytic Hydrogen Generation

Authors: D. Amaranatha Reddy

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Highly efficient and stable co-catalysts materials is of great important for boosting photo charge carrier’s separation, transportation efficiency, and accelerating the catalytic reactive sites of semiconductor photocatalysts. As a result, it is of decisive importance to fabricate low price noble metal free co-catalysts with high catalytic reactivity, but it remains very challenging. Considering this challenge here, dual metal organic frame work derived N-Doped Fe3C nanocages have been rationally designed and decorated with ultrathin ZnIn2S4 nanosheets for efficient photocatalytic hydrogen generation. The fabrication strategy precisely integrates co-catalyst nanocages with ultrathin two-dimensional (2D) semiconductor nanosheets by providing tightly interconnected nano-junctions and helps to suppress the charge carrier’s recombination rate. Furthermore, constructed highly porous hybrid structures expose ample active sites for catalytic reduction reactions and harvest visible light more effectively by light scattering. As a result, fabricated nanostructures exhibit superior solar driven hydrogen evolution rate (9600 µmol/g/h) with an apparent quantum efficiency of 3.6 %, which is relatively higher than the Pt noble metal co-catalyst systems and earlier reported ZnIn2S4 based nanohybrids. We believe that the present work promotes the application of sulfide based nanostructures in solar driven hydrogen production.

Keywords: photocatalysis, water splitting, hydrogen fuel production, solar-driven hydrogen

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1862 Environmental Justice and Marginalized Communities: Addressing Barriers to Energy Justice in the Negev

Authors: Mohammad Naser Aldeen

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This study explores environmental justice issues among Bedouin communities in Israel’s Negev region, focusing on energy access and their exclusion from state-supported energy services. As a historically marginalized and indigenous population, Bedouins face intersecting inequities, including limited access to national grid energy, waste management, access to water, systematic discrimination, and environmental harms such as industrial pollution and land degradation. Employing Pellow’s Critical Environmental Justice framework, this research examines how power relations and intersecting identities – ethnicity, class, and indigeneity – shape energy exclusion. Utilizing K. Arrow’s Barriers Analysis framework, it identifies the multifaceted barriers obstructing equitable energy access, including structural policy deficiencies, socio-economic constraints, and administrative neglect. The study also highlights Bedouins’ resilience, advocacy, and community-led strategies to address these challenges through the adoption of solar energy. A mixed-methods approach integrates quantitative data with qualitative narratives from community leaders, policymakers, and activists, revealing the multidimensional nature of energy inequities in the Negev. Findings emphasize the urgent need for inclusive energy policies that address intersectional barriers and prioritize environmental justice in planning and management. By advancing discourse on energy equity, this research underscores the importance of integrating marginalized communities into sustainable energy systems, contributing to the development of equitable energy policies and fostering pathways toward environmental justice and sustainable development.

Keywords: environmental justice, energy justice, intersectionality, Bedouin communities, barriers analysis

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1861 Exploring the Use of Drones for Corn Borer Management: A Case Study in Central Italy

Authors: Luana Centorame, Alessio Ilari, Marco Giustozzi, Ester Foppa Pedretti

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Maize is one of the most important agricultural cash crops in the world, involving three different chains: food, feed, and bioenergy production. Nowadays, the European corn borer (ECB), Ostrinia nubilalis, to the best of the author's knowledge, is the most important pest to control for maize growers. The ECB is harmful to maize; young larvae are responsible for minor damage to the leaves, while the most serious damage is tunneling by older larvae that burrow into the stock. Soon after, larvae can affect cobs, and it was found that ECB can foster mycotoxin contamination; this is why it is crucial to control it. There are multiple control methods available: agronomic, biological, and microbiological means, agrochemicals, and genetically modified plants. Meanwhile, the European Union’s policy focuses on the transition to sustainable supply chains and translates into the goal of reducing the use of agrochemicals by 50%. The current work aims to compare the agrochemical treatment of ECB and biological control through beneficial insects released by drones. The methodology used includes field trials of both chemical and biological control, considering a farm in central Italy as a case study. To assess the mechanical and technical efficacy of drones with respect to standard machinery, the available literature was consulted. The findings are positive because drones allow them to get in the field promptly, in difficult conditions and with lower costs if compared to traditional techniques. At the same time, it is important to consider the limits of drones regarding pilot certification, no-fly zones, etc. In the future, it will be necessary to deepen the topic with the real application in the field of both systems, expanding the scenarios in which drones can be used and the type of material distributed.

Keywords: beneficial insects, corn borer management, drones, precision agriculture

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1860 Bioreactor Simulator Design: Measuring Built Environment Health and Ecological Implications from Post-Consumer Textiles

Authors: Julia DeVoy, Olivia Berlin

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The United States exports over 1.6 billion pounds of post-consumer textiles every year, primarily to countries in the Global South. These textiles make their way to landfills and open-air dumps where they decompose, contaminating water systems and releasing harmful greenhouse gases. Through this inequitable system of waste disposal, countries with less political and economic power are coerced into accepting the environmental and health consequences of over-consumption in the Global North. Thus, the global trade of post-consumer textile waste represents a serious issue of environmental justice and a public health hazard. Our research located, characterizes, and quantifies the environmental and human health risks that occur when post-consumer textiles are left to decompose in landfills and open-air dumps in the Global South. In our work, we make use of United Nations International Trade Statistics data to map the global distribution of post-consumer textiles exported from the United States. Next, we present our landfill simulating reactor designed to measure toxicity of leachate resulting from the decomposition of textiles in developing countries and to quantify the related greenhouse gas emissions. This design makes use of low-cost and sustainable materials to promote frugal innovation and make landfill reactors more accessible. Finally, we describe how the data generated from these tools can be leveraged to inform individual consumer behaviors, local policies around textile waste disposal, and global advocacy efforts to mitigate the environmental harms caused by textile waste.

Keywords: sustainability, textile design, public health, built environment

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1859 Development of a Methodology for Surgery Planning and Control: A Management Approach to Handle the Conflict of High Utilization and Low Overtime

Authors: Timo Miebach, Kirsten Hoeper, Carolin Felix

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In times of competitive pressures and demographic change, hospitals have to reconsider their strategies as a company. Due to the fact, that operations are one of the main income and one of the primary cost drivers otherwise, a process-oriented approach and an efficient use of resources seems to be the right way for getting a consistent market position. Thus, the efficient operation room occupancy planning is an important cause variable for the success and continued the existence of these institutions. A high utilization of resources is essential. This means a very high, but nevertheless sensible capacity-oriented utilization of working systems that can be realized by avoiding downtimes and a thoughtful occupancy planning. This engineering approach should help hospitals to reach her break-even point. Firstly, the aim is to establish a strategy point, which can be used for the generation of a planned throughput time. Secondly, the operation planning and control should be facilitated and implemented accurately by the generation of time modules. More than 100,000 data records of the Hannover Medical School were analyzed. The data records contain information about the type of conducted operation, the duration of the individual process steps, and all other organizational-specific data such as an operating room. Based on the aforementioned data base, a generally valid model was developed by an analysis to define a strategy point which takes the conflict of capacity utilization and low overtime into account. Furthermore, time modules were generated in this work, which allows a simplified and flexible operation planning and control for the operation manager. By the time modules, it is possible to reduce a high average value of the idle times of the operation rooms. Furthermore, the potential is used to minimize the idle time spread.

Keywords: capacity, operating room, surgery planning and control, utilization

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1858 The Problem of Child Exploitation on Twitter: A Socio-Anthropological Perspective on Content Filtering Gaps

Authors: Samig Ibayev

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This research addresses the problem of illegal child abuse content on the Twitter platform bypassing filtering systems and appearing before users from a social-anthropological perspective. Although the wide access opportunities provided by social media platforms to their users are beneficial in many ways, it is seen that they contain gaps that pave the way for the spread of harmful and illegal content. The aim of the study is to examine the inadequacies of the current content filtering mechanisms of the Twitter platform, to understand the psychological effects of young users unintentionally encountering such content and the social dimensions of this situation. The research was conducted with a qualitative approach and was conducted using digital ethnography, content analysis and user experiences on the Twitter platform. Digital ethnography was used to observe the frequency of child abuse content on the platform and how these contents were presented. The content analysis method was used to reveal the gaps in Twitter's current filtering mechanisms. In addition, detailed information was collected on the extent of psychological effects and how the perception of trust in social media changed through interviews with young users exposed to such content. The main contributions of the research are to highlight the weaknesses in the content moderation and filtering mechanisms of social media platforms, to reveal the negative effects of illegal content on users, and to offer suggestions for preventing the spread of such content. As a result, it is suggested that platforms such as Twitter should improve their content filtering policies in order to increase user security and fulfill their social responsibilities. This research aims to create significant awareness about social media content management and ethical responsibilities on digital platforms.

Keywords: Twitter, child exploitation, content filtering, digital ethnography, social anthropology

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1857 Two-Stage Hospital Efficiency Analysis Including Qualitative Evidence: A Greek Case

Authors: Panos Xenos, Milton Nektarios, John Yfantopoulos

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Background: Policy makers, professional organizations and payers have introduced a variety of initiatives and reforms for the health systems worldwide, aimed at improving hospital efficiency. Their efforts are concentrated in two main categories: to constrain increasing healthcare costs and to enhance quality of services provided. Research Objectives: This study examines the efficiency of 112 Greek public hospitals for the year 2009, evaluates the importance of bootstrapping techniques and investigates the effect of contextual factors on hospital efficiency. Furthermore, the effect of qualitative evidence, on hospital efficiency is explored using data from 28 large hospitals. Methods: We applied Data Envelopment Analysis, augmented by bootstrapping techniques, to estimate efficiency scores. In order to measure the effect of environmental factors on hospital efficiency we used Tobit regression analysis. The significance of our models is evaluated using statistical tests to compare distributions. Results: The Kolmogorov-Smirnov test between the original and the bootstrap-corrected efficiency indicates that their distributions are significantly different (p-value<0.01). The environmental factors, that seem to influence efficiency, are Occupancy Rating and the ratio between Outpatient Visits and Inpatient Days. Results indicate that the inclusion of the quality variable in DEA modelling generates statistically significant variations in efficiency scores (p-value<0.05). Conclusions: The inclusion of quality variables and the use of bootstrap resampling in efficiency analysis impose a statistically significant effect on the distribution of efficiency scores. As a policy conclusion we highlight the importance of these methods on hospital efficiency analysis and, by implication, on healthcare resource allocation.

Keywords: hospitals, efficiency, quality, data envelopment analysis, Greek public hospital sector

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1856 A Step Magnitude Haptic Feedback Device and Platform for Better Way to Review Kinesthetic Vibrotactile 3D Design in Professional Training

Authors: Biki Sarmah, Priyanko Raj Mudiar

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In the modern world of remotely interactive virtual reality-based learning and teaching, including professional skill-building training and acquisition practices, as well as data acquisition and robotic systems, the revolutionary application or implementation of field-programmable neurostimulator aids and first-hand interactive sensitisation techniques into 3D holographic audio-visual platforms have been a coveted dream of many scholars, professionals, scientists, and students. Integration of 'kinaesthetic vibrotactile haptic perception' along with an actuated step magnitude contact profiloscopy in augmented reality-based learning platforms and professional training can be implemented by using an extremely calculated and well-coordinated image telemetry including remote data mining and control technique. A real-time, computer-aided (PLC-SCADA) field calibration based algorithm must be designed for the purpose. But most importantly, in order to actually realise, as well as to 'interact' with some 3D holographic models displayed over a remote screen using remote laser image telemetry and control, all spatio-physical parameters like cardinal alignment, gyroscopic compensation, as well as surface profile and thermal compositions, must be implemented using zero-order type 1 actuators (or transducers) because they provide zero hystereses, zero backlashes, low deadtime as well as providing a linear, absolutely controllable, intrinsically observable and smooth performance with the least amount of error compensation while ensuring the best ergonomic comfort ever possible for the users.

Keywords: haptic feedback, kinaesthetic vibrotactile 3D design, medical simulation training, piezo diaphragm based actuator

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1855 Application of Industrial Ergonomics in Vehicle Service System Design

Authors: Zhao Yu, Zhi-Nan Zhang

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More and more interactive devices are used in the transportation service system. Our mobile phones, on-board computers, and Head-Up Displays (HUDs) can all be used as the tools of the in-car service system. People can access smart systems with different terminals such as mobile phones, computers, pads and even their cars and watches. Different forms of terminals bring the different quality of interaction by the various human-computer Interaction modes. The new interactive devices require good ergonomics design at each stage of the whole design process. According to the theory of human factors and ergonomics, this paper compared three types of interactive devices by four driving tasks. Forty-eight drivers were chosen to experience these three interactive devices (mobile phones, on-board computers, and HUDs) by a simulate driving process. The subjects evaluated ergonomics performance and subjective workload after the process. And subjects were encouraged to support suggestions for improving the interactive device. The result shows that different interactive devices have different advantages in driving tasks, especially in non-driving tasks such as information and entertainment fields. Compared with mobile phones and onboard groups, the HUD groups had shorter response times in most tasks. The tasks of slow-up and the emergency braking are less accurate than the performance of a control group, which may because the haptic feedback of these two tasks is harder to distinguish than the visual information. Simulated driving is also helpful in improving the design of in-vehicle interactive devices. The paper summarizes the ergonomics characteristics of three in-vehicle interactive devices. And the research provides a reference for the future design of in-vehicle interactive devices through an ergonomic approach to ensure a good interaction relationship between the driver and the in-vehicle service system.

Keywords: human factors, industrial ergonomics, transportation system, usability, vehicle user interface

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1854 Harnessing the Power of Large Language Models in Orthodontics: AI-Generated Insights on Class II and Class III Orthopedic Appliances: A Cross-Sectional Study

Authors: Laiba Amin, Rashna H. Sukhia, Mubassar Fida

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Introduction: This study evaluates the accuracy of responses from ChatGPT, Google Bard, and Microsoft Copilot regarding dentofacial orthopedic appliances. As artificial intelligence (AI) increasingly enhances various fields, including healthcare, understanding its reliability in specialized domains like orthodontics becomes crucial. By comparing the accuracy of different AI models, this study aims to shed light on their effectiveness and potential limitations in providing technical insights. Materials and Methods: A total of 110 questions focused on dentofacial orthopedic appliances were posed to each AI model. The responses were then evaluated by five experienced orthodontists using a modified 5-point Likert scale to ensure a thorough assessment of accuracy. This structured approach allowed for consistent and objective rating, facilitating a meaningful comparison between the AI systems. Results: The results revealed that Google Bard demonstrated the highest accuracy at 74%, followed by Microsoft Copilot, with an accuracy of 72.2%. In contrast, ChatGPT was found to be the least accurate, achieving only 52.2%. These results highlight significant differences in the performance of the AI models when addressing orthodontic queries. Conclusions: Our study highlights the need for caution in relying on AI for orthodontic insights. The overall accuracy of the three chatbots was 66%, with Google Bard performing best for removable Class II appliances. Microsoft Copilot was more accurate than ChatGPT, which, despite its popularity, was the least accurate. This variability emphasizes the importance of human expertise in interpreting AI-generated information. Further research is necessary to improve the reliability of AI models in specialized healthcare settings.

Keywords: artificial intelligence, large language models, orthodontics, dentofacial orthopaedic appliances, accuracy assessment.

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1853 Analysis of Motor Nerve Conduction Velocity (MNCV) of Selected Nerves in Athletics

Authors: Jogbinder Singh Soodan, Ashok Kumar, Gobind Singh

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Background: This study aims to describe the motor nerve conduction velocity of selected nerves of both the upper and lower extremities in athletes. Thirty high-level sprinters (100 mts and 200 mts) and thirty high level distance runners (3000 mts) were volunteered to participate in the study. Method: Motor nerve conduction velocities (MNCV) of radial and sural nerves were recorded with the help of computerized equipment, NEUROPERFECT (MEDICAID SYSTEMS, India), with standard techniques of supramaximal percutaneus stimulation. The anthropometric measurements taken were body height (cms), age (yrs) and body weight (kgs). The neurophysiological parameters taken were MNCV of radial nerve (upper extremity) and sural nerve (lower extremity) of both sides (i.e. dominant and non-dominant) of the body. The room temperature was maintained at 37 degree Celsius. Results: Significant differences in motor nerve conduction velocities were found between dominant and non-dominant limbs in each group. The MNCV of radial nerve was obtained was significantly higher in the sprinters than long distance runners. The MNCV of sural nerve recorded was significantly higher in sprinters as compared to distance runners. Conclusion: The motor nerve conduction velocity of radial nerve was found to be higher in sprinters as compared to the distance runners and also, the MNCV for sural nerve was found to be higher in sprinters as compared to distance runners. In case of sprinters, the MNCV of radial and sural nerves were higher in dominant limbs (i.e. arms and legs) of both sides of the body. But, in case of distance runners, the MNCV of radial and sural nerves is higher in non dominant limbs.

Keywords: motor nerve conduction velocity, radial nerve, sural nerve, sprinters

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1852 Microclimate Impacts on Solar Panel Power Generation in Midlands Area, UK

Authors: Stamatis Zoras, Boris Ceranic, Ashley Redfern

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Green House Gas emissions from domestic properties currently account for a substantial part of the total UK’s carbon emissions and is a priority area for UK to reach zero carbon emissions. However, GHG emissions of urban complexes depend on building, road, structural developments etc surfaces that form urban microclimate. This in turn may further influence renewable energy system power generation that depend on solar or wind potential. Moreover, urban climatic conditions are also influenced by the installation of those power generation systems that may impact their own power generation efficiency. Increased air temperature is attributed to densely installed roof based solar panels that consequently impact their own production efficiency. Installation of roof based solar panels requires adequate guidance to enable housing businesses, councils and organisations to implement sufficient measures for improved power generation in relation to local urban microclimate. How microclimate is affected and how, in return, it affects solar power productivity. Derby Council & Derby Homes have been collecting solar panel power generation data for a large number of properties. The different building areas and system operation performance will be studied against microclimate conditions through time. It is envisaged that the outcomes of the study will support a working up strategy for Derby city to ensure that owned homes would be able to access information and data of solar photo voltaic PV and solar thermal panels potential on social housing, helping residents on low incomes create their own green energy to power their homes and heat their homeshot water.

Keywords: microclimate, solar power, urban climatology, urban morphology

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1851 Examining Three Psychosocial Factors of Tax Compliance in Self-Employed Individuals using the Mindspace Framework - Evidence from Australia and Pakistan

Authors: Amna Tariq Shah

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Amid the pandemic, the contemporary landscape has experienced accelerated growth in small business activities and an expanding digital marketplace, further exacerbating the issue of non-compliance among self-employed individuals through aggressive tax planning and evasion. This research seeks to address these challenges by developing strategic tax policies that promote voluntary compliance and improve taxpayer facilitation. The study employs the innovative MINDSPACE framework to examine three psychosocial factors—tax communication, tax literacy, and shaming—to optimize policy responses, address administrative shortcomings, and ensure adequate revenue collection for public goods and services. Preliminary findings suggest that incomprehensible communication from tax authorities drives individuals to seek alternative, potentially biased sources of tax information, thereby exacerbating non-compliance. Furthermore, the study reveals low tax literacy among Australian and Pakistani respondents, with many struggling to navigate complex tax processes and comprehend tax laws. Consequently, policy recommendations include simplifying tax return filing and enhancing pre-populated tax returns. In terms of shaming, the research indicates that Australians, being an individualistic society, may not respond well to shaming techniques due to privacy concerns. In contrast, Pakistanis, as a collectivistic society, may be more receptive to naming and shaming approaches. The study employs a mixed-method approach, utilizing interviews and surveys to analyze the issue in both jurisdictions. The use of mixed methods allows for a more comprehensive understanding of tax compliance behavior, combining the depth of qualitative insights with the generalizability of quantitative data, ultimately leading to more robust and well-informed policy recommendations. By examining evidence from opposite jurisdictions, namely a developed country (Australia) and a developing country (Pakistan), the study's applicability is enhanced, providing perspectives from two disparate contexts that offer insights from opposite ends of the economic, cultural, and social spectra. The non-comparative case study methodology offers valuable insights into human behavior, which can be applied to other jurisdictions as well. The application of the MINDSPACE framework in this research is particularly significant, as it introduces a novel approach to tax compliance behavior analysis. By integrating insights from behavioral economics, the framework enables a comprehensive understanding of the psychological and social factors influencing taxpayer decision-making, facilitating the development of targeted and effective policy interventions. This research carries substantial importance as it addresses critical challenges in tax compliance and administration, with far-reaching implications for revenue collection and the provision of public goods and services. By investigating the psychosocial factors that influence taxpayer behavior and utilizing the MINDSPACE framework, the study contributes invaluable insights to the field of tax policy. These insights can inform policymakers and tax administrators in developing more effective tax policies that enhance taxpayer facilitation, address administrative obstacles, promote a more equitable and efficient tax system, and foster voluntary compliance, ultimately strengthening the financial foundation of governments and communities.

Keywords: individual tax compliance behavior, psychosocial factors, tax non-compliance, tax policy

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1850 Investigation of the Controversial Immunomodulatory Potential of Trichinella spiralis Excretory-Secretory Products versus Extracellular Vesicles Derived from These Products in vitro

Authors: Natasa Ilic, Alisa Gruden-Movsesijan, Maja Kosanovic, Sofija Glamoclija, Marina Bekic, Ljiljana Sofronic-Milosavljevic, Sergej Tomic

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As a very promising candidate for modulation of immune response in the sense of biasing the inflammatory towards an anti-inflammatory type of response, Trichinella spiralis infection was shown to successfully alleviate the severity of experimental autoimmune encephalomyelitis, the animal model of human disease multiple sclerosis. This effect is achieved via its excretory-secretory muscle larvae (ES L1) products which affect the maturation status and function of dendritic cells (DCs) by inducing the tolerogenic status of DCs, which leads to the mitigation of the Th1 type of response and the activation of a regulatory type of immune response both in vitro and in vivo. ES L1 alone or via treated DCs successfully mitigated EAE in the same manner as the infection itself. On the other hand, it has been shown that T. spiralis infection slows down the tumour growth and significantly reduces the tumour size in the model of mouse melanoma, while ES L1 possesses a pro-apoptotic and anti-survival effect on melanoma cells in vitro. Hence, although the mechanisms still need to be revealed, T. spiralis infection and its ES L1 products have a bit of controversial potential to modulate both inflammatory diseases and malignancies. The recent discovery of T. spiralis extracellular vesicles (TsEVs) suggested that the induction of complex regulation of the immune response requires simultaneous delivery of different signals in nano-sized packages. This study aimed to explore whether TsEVs bare the similar potential as ES L1 to influence the status of DCs in initiation, progression and regulation of immune response, but also to investigate the effect of both ES L1 and TsEVs on myeloid derived suppressor cells (MDSC) which present the regular tumour tissue environment. TsEVs were enriched from the conditioned medium of T. spiralis muscle larvae by differential centrifugation and used for the treatment of human monocyte-derived DCs and MDSC. On DCs, TsEVs induced low expression of HLA DR and CD40, moderate CD83 and CD86, and increased expression of ILT3 and CCR7 on treated DCs, i.e., they induced tolerogenic DCs. Such DCs possess the capacity to polarize T cell immune response towards regulatory type, with an increased proportion of IL-10 and TGF-β producing cells, similarly to ES L1. These findings indicated that the ability of TsEVs to induce tolerogenic DCs favoring anti-inflammatory responses may be helpful in coping with diseases that involve Th1/Th17-, but also Th2-mediated inflammation. In MDSC in vitro model, although both ES L1 and TsEVs had the same impact on MDSC phenotype i.e., they acted suppressive, ES L1 treated MDSC, unlike TsEVs treated ones, induced T cell response characterized by the increased RoRγT and IFN-γ, while the proportion of regulatory cells was decreased followed by the decrease in IL-10 and TGF-β positive cells proportion within this population. These findings indicate the interesting ability of ES L1 to modulate T cells response via MDSC towards pro-inflamatory type, suggesting that, unlike TsEVs which consistently demonstrate the suppresive effect on inflammatory response, it could be used also for the development of new approaches aimed for the treatment of malignant diseases. Acknowledgment: This work was funded by the Promis project – Nano-MDCS-Thera, Science Fund, Republic of Serbia.

Keywords: dendritic cells, myeloid derived suppressor cells, immunomodulation, Trichinella spiralis

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1849 Functional Connectivity Signatures of Polygenic Depression Risk in Youth

Authors: Louise Moles, Steve Riley, Sarah D. Lichenstein, Marzieh Babaeianjelodar, Robert Kohler, Annie Cheng, Corey Horien Abigail Greene, Wenjing Luo, Jonathan Ahern, Bohan Xu, Yize Zhao, Chun Chieh Fan, R. Todd Constable, Sarah W. Yip

Abstract:

Background: Risks for depression are myriad and include both genetic and brain-based factors. However, relationships between these systems are poorly understood, limiting understanding of disease etiology, particularly at the developmental level. Methods: We use a data-driven machine learning approach connectome-based predictive modeling (CPM) to identify functional connectivity signatures associated with polygenic risk scores for depression (DEP-PRS) among youth from the Adolescent Brain and Cognitive Development (ABCD) study across diverse brain states, i.e., during resting state, during affective working memory, during response inhibition, during reward processing. Results: Using 10-fold cross-validation with 100 iterations and permutation testing, CPM identified connectivity signatures of DEP-PRS across all examined brain states (rho’s=0.20-0.27, p’s<.001). Across brain states, DEP-PRS was positively predicted by increased connectivity between frontoparietal and salience networks, increased motor-sensory network connectivity, decreased salience to subcortical connectivity, and decreased subcortical to motor-sensory connectivity. Subsampling analyses demonstrated that model accuracies were robust across random subsamples of N’s=1,000, N’s=500, and N’s=250 but became unstable at N’s=100. Conclusions: These data, for the first time, identify neural networks of polygenic depression risk in a large sample of youth before the onset of significant clinical impairment. Identified networks may be considered potential treatment targets or vulnerability markers for depression risk.

Keywords: genetics, functional connectivity, pre-adolescents, depression

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1848 Water Quality Calculation and Management System

Authors: H. M. B. N Jayasinghe

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The water is found almost everywhere on Earth. Water resources contain a lot of pollution. Some diseases can be spread through the water to the living beings. So to be clean water it should undergo a number of treatments necessary to make it drinkable. So it is must to have purification technology for the wastewater. So the waste water treatment plants act a major role in these issues. When considering the procedures taken after the water treatment process was always based on manual calculations and recordings. Water purification plants may interact with lots of manual processes. It means the process taking much time consuming. So the final evaluation and chemical, biological treatment process get delayed. So to prevent those types of drawbacks there are some computerized programmable calculation and analytical techniques going to be introduced to the laboratory staff. To solve this problem automated system will be a solution in which guarantees the rational selection. A decision support system is a way to model data and make quality decisions based upon it. It is widely used in the world for the various kind of process automation. Decision support systems that just collect data and organize it effectively are usually called passive models where they do not suggest a specific decision but only reveal information. This web base system is based on global positioning data adding facility with map location. Most worth feature is SMS and E-mail alert service to inform the appropriate person on a critical issue. The technological influence to the system is HTML, MySQL, PHP, and some other web developing technologies. Current issues in the computerized water chemistry analysis are not much deep in progress. For an example the swimming pool water quality calculator. The validity of the system has been verified by test running and comparison with an existing plant data. Automated system will make the life easier in productively and qualitatively.

Keywords: automated system, wastewater, purification technology, map location

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1847 Pros and Cons of Nanoparticles on Health

Authors: Amber Shahi, Ayesha Tazeen, Abdus Samad, Shama Parveen

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Nanoparticles (NPs) are tiny particles. According to the International Organization for Standardization, the size range of NPs is in the nanometer range (1-100 nm). They show distinct properties that are not shown by larger particles of the same material. NPs are currently being used in different fields due to their unique physicochemical nature. NPs are a boon for medical sciences, environmental sciences, electronics, and textile industries. However, there is growing concern about their potential adverse effects on human health. This poster presents a comprehensive review of the current literature on the pros and cons of NPs on human health. The poster will discuss the various types of interactions of NPs with biological systems. There are a number of beneficial uses of NPs in the field of health and environmental welfare. NPs are very useful in disease diagnosis, antimicrobial action, and the treatment of diseases like Alzheimer’s. They can also cross the blood-brain barrier, making them capable of treating brain diseases. Additionally, NPs can target specific tumors and be used for cancer treatment. To treat environmental health, NPs also act as catalytic converters to reduce pollution from the environment. On the other hand, NPs also have some negative impacts on the human body, such as being cytotoxic and genotoxic. They can also affect the reproductive system, such as the testis and ovary, and sexual behavior. The poster will further discuss the routes of exposure of NPs. The poster will conclude with a discussion of the current regulations and guidelines on the use of NPs in various applications. It will highlight the need for further research and the development of standardized toxicity testing methods to ensure the safe use of NPs in various applications. When using NPs in diagnosis and treatment, we should also take into consideration their safe concentration in the body. Overall, this poster aims to provide a comprehensive overview of the pros and cons of NPs on human health and to promote awareness and understanding of the potential risks and benefits associated with their use.

Keywords: disease diagnosis, human health, nanoparticles, toxicity testing

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1846 Mobi Navi Tour for Rescue Operations

Authors: V. R. Sadasivam, M. Vipin, P. Vineeth, M. Sajith, G. Sathiskumar, R. Manikandan, N. Vijayarangan

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Global positioning system technology is what leads to such things as navigation systems, GPS tracking devices, GPS surveying and GPS mapping. All that GPS does is provide a set of coordinates which represent the location of GPS units with respect to its latitude, longitude and elevation on planet Earth. It also provides time, which is accurate. The tracking devices themselves come in different flavors. They will contain a GPS receiver, and GPS software, along with some way of transmitting the resulting coordinates. GPS in mobile tend to use radio waves to transmit their location to another GPS device. The purpose of this prototype “Mobi Navi Tour for Rescue Operation” timely communication, and lightning fast decision-making with a group of people located in different places with a common goal. Timely communication and tracking the people are a critical issue in many situations, environments. Expedited can find missing person by sending the location and other related information to them through mobile. Information must be drawn from the caller and entered into the system by the administrator or a group leader and transferred to the group leader. This system will locate the closest available person, a group of people working in an organization/company or vehicle to determine availability and their position to track them. Misinformation cannot lead to the wrong decision in the rapidly paced environment in a normal and an abnormal situation. In “Mobi Navi Tour for Rescue Operation” we use Google Cloud Messaging for android (GCM) which is a service that helps developers send data from servers to their android applications on android devices. The service provides a simple, lightweight mechanism that servers can use to tell mobile applications to contact the server directly, to fetch updated application or user data.

Keywords: android, gps, tour, communication, service

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1845 Impact of Increased Radiology Staffing on After-Hours Radiology Reporting Efficiency and Quality

Authors: Peregrine James Dalziel, Philip Vu Tran

Abstract:

Objective / Introduction: Demand for radiology services from Emergency Departments (ED) continues to increase with greater demands placed on radiology staff providing reports for the management of complex cases. Queuing theory indicates that wide variability of process time with the random nature of request arrival increases the probability of significant queues. This can lead to delays in the time-to-availability of radiology reports (TTA-RR) and potentially impaired ED patient flow. In addition, greater “cognitive workload” of greater volume may lead to reduced productivity and increased errors. We sought to quantify the potential ED flow improvements obtainable from increased radiology providers serving 3 public hospitals in Melbourne Australia. We sought to assess the potential productivity gains, quality improvement and the cost-effectiveness of increased labor inputs. Methods & Materials: The Western Health Medical Imaging Department moved from single resident coverage on weekend days 8:30 am-10:30 pm to a limited period of 2 resident coverage 1 pm-6 pm on both weekend days. The TTA-RR for weekend CT scans was calculated from the PACs database for the 8 month period symmetrically around the date of staffing change. A multivariate linear regression model was developed to isolate the improvement in TTA-RR, between the two 4-months periods. Daily and hourly scan volume at the time of each CT scan was calculated to assess the impact of varying department workload. To assess any improvement in report quality/errors a random sample of 200 studies was assessed to compare the average number of clinically significant over-read addendums to reports between the 2 periods. Cost-effectiveness was assessed by comparing the marginal cost of additional staffing against a conservative estimate of the economic benefit of improved ED patient throughput using the Australian national insurance rebate for private ED attendance as a revenue proxy. Results: The primary resident on call and the type of scan accounted for most of the explained variability in time to report availability (R2=0.29). Increasing daily volume and hourly volume was associated with increased TTA-RR (1.5m (p<0.01) and 4.8m (p<0.01) respectively per additional scan ordered within each time frame. Reports were available 25.9 minutes sooner on average in the 4 months post-implementation of double coverage (p<0.01) with additional 23.6 minutes improvement when 2 residents were on-site concomitantly (p<0.01). The aggregate average improvement in TTA-RR was 24.8 hours per weekend day This represents the increased decision-making time available to ED physicians and potential improvement in ED bed utilisation. 5% of reports from the intervention period contained clinically significant addendums vs 7% in the single resident period but this was not statistically significant (p=0.7). The marginal cost was less than the anticipated economic benefit based assuming a 50% capture of improved TTA-RR inpatient disposition and using the lowest available national insurance rebate as a proxy for economic benefit. Conclusion: TTA-RR improved significantly during the period of increased staff availability, both during the specific period of increased staffing and throughout the day. Increased labor utilisation is cost-effective compared with the potential improved productivity for ED cases requiring CT imaging.

Keywords: workflow, quality, administration, CT, staffing

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1844 Adaptable Regulatory Oversight and Safety Awareness Regime: An Experience-Based Contribution Towards Sustainability in a Changing Railway Environment

Authors: Peaceman Sopazi, Mabila Mathebula, John Smallwood

Abstract:

Recent health and safety (H&S) concerns and their resultant impact on railway operations, namely, the severe acute respiratory syndrome (SARS) or collectively known as SARS-CoV-2 (Covid-19) pandemic and the Fourth Industrial Revolution (4IR), which have dominated public discourse, brought into question as to whether, or not, some aspects of how we have so far managed safety oversight as railway regulatory bodies and operators will remain relevant in a changing railway environment. Railway practitioners have generally found themselves between a proverbial rock and a hard place by being confronted by emerging challenges which have brought along great opportunities for sustainability. As witnesses and participants to the progressively introduced railway safety management, and transformation regimes, this paper attempts to share gathered field experience on adaptable regulatory oversight and safety awareness. The discourse is approached from a South African context but also with an informed perspective of what seems to work and what usually does not. The authors share their own multi and transdisciplinary experience coupled with insights they have gained as researchers of global trends in general safety management and specific aspects of railway safety management, for sustainability. In addition to sharing a largely experience-based methodology for survival, suggestions are offered for consideration as a way of keeping the railway safety management discourse alive as practitioners navigate a new path which is shrouded in a cloud of untold uncertainty. The authors further believe that the right timing for the implementation of the proposed suggestions in this paper will produce beneficial outcomes. Finally, the paper will identify areas that are still open for further investigation for and by researchers and practitioners alike.

Keywords: health & safety management, safety awareness, railway safety management, railway systems sustainability

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1843 Influence of Organic Modifier Loading on Particle Dispersion of Biodegradable Polycaprolactone/Montmorillonite Nanocomposites

Authors: O. I. H. Dimitry, N. A. Mansour, A. L. G. Saad

Abstract:

Natural sodium montmorillonite (NaMMT), Cloisite Na+ and two organophilic montmorillonites (OMMTs), Cloisites 20A and 15A were used. Polycaprolactone (PCL)/MMT composites containing 1, 3, 5, and 10 wt% of Cloisite Na+ and PCL/OMMT nanocomposites containing 5 and 10 wt% of Cloisites 20A and 15A were prepared via solution intercalation technique to study the influence of organic modifier loading on particle dispersion of PCL/ NaMMT composites. Thermal stabilities of the obtained composites were characterized by thermal analysis using the thermogravimetric analyzer (TGA) which showed that in the presence of nitrogen flow the incorporation of 5 and 10 wt% of filler brings some decrease in PCL thermal stability in the sequence: Cloisite Na+>Cloisite 15A > Cloisite 20A, while in the presence of air flow these fillers scarcely influenced the thermoxidative stability of PCL by slightly accelerating the process. The interaction between PCL and silicate layers was studied by Fourier transform infrared (FTIR) spectroscopy which confirmed moderate interactions between nanometric silicate layers and PCL segments. The electrical conductivity (σ) which describes the ionic mobility of the systems was studied as a function of temperature and showed that σ of PCL was enhanced on increasing the modifier loading at filler content of 5 wt%, especially at higher temperatures in the sequence: Cloisite Na+<Cloisite 20A<Cloisite 15A, and was then decreased to some extent with a further increase to 10 wt%. The activation energy Eσ obtained from the dependency of σ on temperature using Arrhenius equation was found to be lowest for the nanocomposite containing 5 wt% of Cloisite 15A. The dispersed behavior of clay in PCL matrix was evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses which revealed partial intercalated structures in PCL/NaMMT composites and semi-intercalated/semi-exfoliated structures in PCL/OMMT nanocomposites containing 5 wt% of Cloisite 20A or Cloisite 15A.

Keywords: electrical conductivity, montmorillonite, nanocomposite, organoclay, polycaprolactone

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1842 Dental Education in Brazil: A Systematic Literature Review

Authors: Fabiane Alves Farias Guimarães, Rodrigo Otávio Moretti-Pires, Ana Lúcia Schaefer Ferreira de Mello

Abstract:

Introduction: Considering the last changes in Brazilian Health and Higher Educational Systems, the production of scientific knowledge regarding dental education and training has been increasing. The National Curriculum Guidelines for undergraduate courses in Dentistry established in 2002 the principles and procedures to perform a more generalist dental professional profile. Objectives: To perform a systematic review of the Brazilian scientific literature about dental education and training. Methods: The systematic review was conducted considering the Lilacs - Latin American Literature in Health Sciences and SciELO - Scientific Electronic Library Online data bases, using the combination of key words dentistry, education, teaching or training. It was select original research articles, published between 2010 and 2013, in Portuguese. Results: Based on the selection criteria, it was found 23 articles. In order to organize the outcomes, the analysis was separated in three themes: Ethical aspects of education (3 articles), integrating dental service with training (10 articles) and Dental education and the Brazilian curriculum guidelines (10 articles). Most of the studies were published between 2011 and 2012 (35% each) and were held in public universities. The studied populations included dental students, teachers, universities directors, health managers and dentists. The qualitative methodological approach was predominant. Conclusion: It was possible to identify a transience time in Brazilian undergraduate courses in Dentistry after curricular changes. The produced literature shows some advances, as the incorporation of ethical values on dental education and the inclusion of new practices environments for students by integrating education and training in diversified dental services scenarios.

Keywords: Teaching, Dental Students, Human resources in dentistry

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1841 Alternative Systems of Drinking Water Supply Using Rainwater Harvesting for Small Rural Communities with Zero Greenhouse Emissions

Authors: Martin Mundo-Molina

Abstract:

In Mexico, there are many small rural communities with serious water supply deficiencies. In Chiapas, Mexico, there are 19,972 poor rural communities, 15,712 of which have fewer than 100 inhabitants. The lack of a constant water supply is most severe in the highlands of Chiapas where the population is made up mainly of indigenous groups. The communities are on mountainous terrain with a widely dispersed population. These characteristics combine to make the provision of public utilities, such as water, electricity and sewerage, difficult with conventional means. The introduction of alternative, low-cost technologies represents means of supplying water such as through fog and rain catchment with zero greenhouse emissions. In this paper is presented the rainwater harvesting system (RWS) constructed in Yalentay, Chiapas Mexico. The RWS is able to store 1.2 M liters of water to provide drinking water to small rural indigenous communities of 500 people in the drought stage. Inside the system of rainwater harvesting there isn't photosynthesis in order to conserve water for long periods. The natural filters of the system of rainwater harvesting guarantee the drinking water for using to the community. The combination of potability and low cost makes rain collection a viable alternative for rural areas, weather permitting. The Mexican Institute of Water Technology and Chiapas University constructed a rainwater harvesting system in Yalentay Chiapas, it consists of four parts: 1. Roof of aluminum, for collecting rainwater, 2. Underground-cistern, divided in two tanks, 3. Filters, to improve the water quality and 4. The system of rainwater harvesting dignified the lives of people in Yalentay, saves energy, prevents the emission of greenhouse gases into the atmosphere, conserves natural resources such as water and air.

Keywords: appropriate technologies, climate change, greenhouse gases, rainwater harvesting

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1840 Increasing Creativity in Virtual Learning Space for Developing Creative Cities

Authors: Elham Fariborzi, Hoda Anvari Kazemabad

Abstract:

Today, ICT plays an important role in all matters and it affects the development of creative cities. According to virtual space in this technology, it use especially for expand terms like smart schools, Virtual University, web-based training and virtual classrooms that is in parallel with the traditional teaching. Nowadays, the educational systems in different countries such as Iran are changing and start increasing creativity in the learning environment. It will contribute to the development of innovative ideas and thinking of the people in this environment; such opportunities might be cause scientific discovery and development issues. The creativity means the ability to generate ideas and numerous, new and suitable solutions for solving the problems of real and virtual individuals and society, which can play a significant role in the development of creative current physical cities or virtual borders ones in the future. The purpose of this paper is to study strategies to increase creativity in a virtual learning to develop a creative city. In this paper, citation/ library study was used. The full description given in the text, including how to create and enhance learning creativity in a virtual classroom by reflecting on performance and progress; attention to self-directed learning guidelines, efficient use of social networks, systematic discussion groups and non-intuitive targeted controls them by involved factors and it may be effective in the teaching process regarding to creativity. Meanwhile, creating a virtual classroom the style of class recognizes formally the creativity. Also the use of a common model of creative thinking between student/teacher is effective to solve problems of virtual classroom. It is recommended to virtual education’ authorities in Iran to have a special review to the virtual curriculum for increasing creativity in educational content and such classes to be witnesses more creative in Iran's cities.

Keywords: virtual learning, creativity, e-learning, bioinformatics, biomedicine

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1839 Adaptive Design of Large Prefabricated Concrete Panels Collective Housing

Authors: Daniel M. Muntean, Viorel Ungureanu

Abstract:

More than half of the urban population in Romania lives today in residential buildings made out of large prefabricated reinforced concrete panels. Since their initial design was made in the 1960’s, these housing units are now being technically and morally outdated, consuming large amounts of energy for heating, cooling, ventilation and lighting, while failing to meet the needs of the contemporary life-style. Due to their widespread use, the design of a system that improves their energy efficiency would have a real impact, not only on the energy consumption of the residential sector, but also on the quality of life that it offers. Furthermore, with the transition of today’s existing power grid to a “smart grid”, buildings could become an active element for future electricity networks by contributing in micro-generation and energy storage. One of the most addressed issues today is to find locally adapted strategies that can be applied considering the 20-20-20 EU policy criteria and to offer sustainable and innovative solutions for the cost-optimal energy performance of buildings adapted on the existing local market. This paper presents a possible adaptive design scenario towards sustainable retrofitting of these housing units. The apartments are transformed in order to meet the current living requirements and additional extensions are placed on top of the building, replacing the unused roof space, acting not only as housing units, but as active solar energy collection systems. An adaptive building envelope is ensured in order to achieve overall air-tightness and an elevator system is introduced to facilitate access to the upper levels.

Keywords: adaptive building, energy efficiency, retrofitting, residential buildings, smart grid

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1838 Improving Pneumatic Artificial Muscle Performance Using Surrogate Model: Roles of Operating Pressure and Tube Diameter

Authors: Van-Thanh Ho, Jaiyoung Ryu

Abstract:

In soft robotics, the optimization of fluid dynamics through pneumatic methods plays a pivotal role in enhancing operational efficiency and reducing energy loss. This is particularly crucial when replacing conventional techniques such as cable-driven electromechanical systems. The pneumatic model employed in this study represents a sophisticated framework designed to efficiently channel pressure from a high-pressure reservoir to various muscle locations on the robot's body. This intricate network involves a branching system of tubes. The study introduces a comprehensive pneumatic model, encompassing the components of a reservoir, tubes, and Pneumatically Actuated Muscles (PAM). The development of this model is rooted in the principles of shock tube theory. Notably, the study leverages experimental data to enhance the understanding of the interplay between the PAM structure and the surrounding fluid. This improved interactive approach involves the use of morphing motion, guided by a contraction function. The study's findings demonstrate a high degree of accuracy in predicting pressure distribution within the PAM. The model's predictive capabilities ensure that the error in comparison to experimental data remains below a threshold of 10%. Additionally, the research employs a machine learning model, specifically a surrogate model based on the Kriging method, to assess and quantify uncertainty factors related to the initial reservoir pressure and tube diameter. This comprehensive approach enhances our understanding of pneumatic soft robotics and its potential for improved operational efficiency.

Keywords: pneumatic artificial muscles, pressure drop, morhing motion, branched network, surrogate model

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1837 Hub Traveler Guidance Signage Evaluation via Panoramic Visualization Using Entropy Weight Method and TOPSIS

Authors: Si-yang Zhang, Chi Zhao

Abstract:

Comprehensive transportation hubs are important nodes of the transportation network, and their internal signage the functions as guidance and distribution assistance, which directly affects the operational efficiency of traffic in and around the hubs. Reasonably installed signage effectively attracts the visual focus of travelers and improves wayfinding efficiency. Among the elements of signage, the visual guidance effect is the key factor affecting the information conveyance, whom should be evaluated during design and optimization process. However, existing evaluation methods mostly focus on the layout, and are not able to fully understand if signage caters travelers’ need. This study conducted field investigations and developed panoramic videos for multiple transportation hubs in China, and designed survey accordingly. Human subjects are recruited to watch panoramic videos via virtual reality (VR) and respond to the surveys. In this paper, Pudong Airport and Xi'an North Railway Station were studied and compared as examples due to their high traveler volume and relatively well-developed traveler service systems. Visual attention was captured by eye tracker and subjective satisfaction ratings were collected through surveys. Entropy Weight Method (EWM) was utilized to evaluate the effectiveness of signage elements and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to further rank the importance of the elements. The results show that the degree of visual attention of travelers significantly affects the evaluation results of guidance signage. Key factors affecting visual attention include accurate legibility, obstruction and defacement rates, informativeness, and whether signage is set up in a hierarchical manner.

Keywords: traveler guidance signage, panoramic video, visual attention, entropy weight method, TOPSIS

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1836 Secondary Radiation in Laser-Accelerated Proton Beamline (LAP)

Authors: Seyed Ali Mahdipour, Maryam Shafeei Sarvestani

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Radiation pressure acceleration (RPA) and target normal sheath acceleration (TNSA) are the most important methods of Laser-accelerated proton beams (LAP) planning systems.LAP has inspired novel applications that can benefit from proton bunch properties different from conventionally accelerated proton beams. The secondary neutron and photon produced in the collision of protons with beamline components are of the important concern in proton therapy. Various published Monte Carlo researches evaluated the beamline and shielding considerations for TNSA method, but there is no studies directly address secondary neutron and photon production from RPA method in LAP. The purpose of this study is to calculate the flux distribution of neutron and photon secondary radiations on the first area ofLAP and to determine the optimize thickness and radius of the energyselector in a LAP planning system based on RPA method. Also, we present the Monte Carlo calculations to determine the appropriate beam pipe for shielding a LAP planning system. The GEANT4 Monte Carlo toolkit has been used to simulate a secondary radiation production in LAP. A section of new multifunctional LAP beamlinehas been proposed, based on the pulsed power solenoid scheme as a GEANT4 toolkit. The results show that the energy selector is the most important source of neutron and photon secondary particles in LAP beamline. According to the calculations, the pure Tungsten energy selector not be the proper case, and using of Tungsten+Polyethylene or Tungsten+Graphitecomposite selectors will reduce the production of neutron and photon intensities by approximately ~10% and ~25%, respectively. Also the optimal radiuses of energy selectors were found to be ~4 cm and ~6 cm for a 3 degree and 5 degree proton deviation angles, respectively.

Keywords: neutron, photon, flux distribution, energy selector, GEANT4 toolkit

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1835 La0.80Ag0.15MnO3 Magnetic Nanoparticles for Self-Controlled Magnetic Fluid Hyperthermia

Authors: Marian Mihalik, Kornel Csach, Martin Kovalik, Matúš Mihalik, Martina Kubovčíková, Maria Zentková, Martin Vavra, Vladimír Girman, Jaroslav Briančin, Marija Perovic, Marija Boškovic, Magdalena Fitta, Robert Pelka

Abstract:

Current nanomaterials for use in biomedicine are based mainly on iron oxides and on present knowledge on magnetic nanostructures. Manganites can represent another material which can be used optionally. Manganites and their unique electronic properties have been extensively studied in the last decades not only due to fundamental interest but to possible applications of colossal magnetoresistance, magnetocaloric effect, and ferroelectric properties. It was found that the oxygen-reduction reaction on perovskite oxide is intimately connected with metal ion e.g., orbital occupation. The effect of oxygen deviation from the stoichiometric composition on crystal structure was studied very carefully by many authors on LaMnO₃. Depending on oxygen content, the crystal structure changes from orthorhombic one to rhombohedric for oxygen content 3.1. In the case of hole-doped manganites, the change from the orthorhombic crystal structure, which is typical for La1-xCaxMnO3 based manganites, to the rhombohedric crystal structure (La1-xMxMnO₃ where M = K, Ag, and Sr based materials) results in an enormous increase of the Curie temperature. In our paper, we study the effect of oxygen content on crystal structure, thermal, and magnetic properties (including magnetocaloric effect) of La1-xAgxMnO₃nano particle system. The content of oxygen in samples was tuned by heat treatment in different thermal regimes and in various environment (air, oxygen, argon). Water nanosuspensions based on La0.80Ag0.15MnO₃ magnetic particles with the Curie temperature of about 43oC were prepared by two different approaches. First, by using a laboratory circulation mill for milling of powder in the presence of sodium dodecyl sulphate (SDS) and subsequent centrifugation. Second nanosuspension was prepared using an agate bowl, etching in citric acid and HNO3, ultrasound homogeniser, centrifugation, and dextran 40 kDA or 15 kDA as surfactant. Electrostatic stabilisation obtained by the first approach did not offer long term kinetic and aggregation colloidal stability and was unable to compensate for attractive forces between particles under a magnetic field. By the second approach, we prepared suspension oversaturated by dextran 40 kDA for steric stabilisation, with evidence of the presence of superparamagnetic behaviour. Low concentration of nanoparticles and not ideal coverage of nanoparticles impacting the stability of ferrofluids was the disadvantage of this approach. Strong steric stabilisation was observable at alcaic conditions under pH = ~10. Application of dextran 15 kDA leads to relatively stable ferrofluid with pH around physiological conditions, but desegregation of powder by HNO₃ was not effective enough, and the average size of fragments was to large of about 150 nm, and we did not see any signature of superparamagnetic behaviour. The prepared ferrofluids were characterised by scanning and transition microscope method, thermogravimetry, magnetization, and AC susceptibility measurements. Specific Absorption Rate measurements were undertaken on powder as well on ferrofluids in order to estimate the potential application of La₀.₈₀Ag₀.₁₅MnO₃ magnetic particles based ferrofluid for hyperthermia. Our complex study contains an investigation of biocompatibility and potential biohazard of this material.

Keywords: manganites, magnetic nanoparticles, oxygen content, magnetic phase transition, magnetocaloric effect, ferrofluid, hyperthermia

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1834 Deltamethrin-Induces Oxidative Stress to the Freshwater Ciliate Model: Paramecium tetraurelia

Authors: Amamra Ryma, Djebar Mohamed Reda, Moumeni Ouissem, Otmani Hadjer, Berrebbah Houria

Abstract:

The problem of environmental contamination by the excessive use of organics cannot be neglected. Extensive application is usually companied with serious problems and health risk. It is established that many chemicals, in common use, can produce some toxic effects on biological systems through their mode of action or by production of free radicals that damage all cell compounds. Deltamethrin, a widely used type II pyrethroid pesticide, is one of the most common contaminants in freshwater aquatic system. In this study, we investigate the effects of deltamethrin exposure on the induction of oxidative stress to the freshwater ciliate Paramecium tetraurelia. After the treatment of paramecium cells with increasing concentrations of insecticide, we followed up the growth kinetics, generation time and the percentage response. Also, we studied the variation in biomarkers of stress such as: GSH content, GST, GPX and CAT activities. Our results showed a significant decrease in the proliferation of cells correlated by the decrease in generation number and the increase in generation time. Also, we noted an inhibition in the percentage response. The monitoring of biomarkers revealed depletion in GSH content in a proportional and dose dependent manner accompanied by an increase in the GST activity. In parallel, a strong induction in the CAT and GPX activities was noted specially for the highest dose. In summary, under the current experimental conditions, deltamethrin is highly toxic to the freshwater ciliate Paramecium tetraurelia. Exposure to low concentrations showed significant adverse on growth accompanied with the induction of oxidative damage supported by the decrease in GSH content and the intensification of the antioxidant enzymes.

Keywords: deltamethrin, Paramecium tetraurelia, growth, oxidative stress, biomarkers, antioxidant

Procedia PDF Downloads 470