Search results for: nuclear emergency
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1846

Search results for: nuclear emergency

136 Liquid Food Sterilization Using Pulsed Electric Field

Authors: Tanmaya Pradhan, K. Midhun, M. Joy Thomas

Abstract:

Increasing the shelf life and improving the quality are important objectives for the success of packaged liquid food industry. One of the methods by which this can be achieved is by deactivating the micro-organisms present in the liquid food through pasteurization. Pasteurization is done by heating, but some serious disadvantages such as the reduction in food quality, flavour, taste, colour, etc. were observed because of heat treatment, which leads to the development of newer methods instead of pasteurization such as treatment using UV radiation, high pressure, nuclear irradiation, pulsed electric field, etc. In recent years the use of the pulsed electric field (PEF) for inactivation of the microbial content in the food is gaining popularity. PEF uses a very high electric field for a short time for the inactivation of microorganisms, for which we require a high voltage pulsed power source. Pulsed power sources used for PEF treatments are usually in the range of 5kV to 50kV. Different pulse shapes are used, such as exponentially decaying and square wave pulses. Exponentially decaying pulses are generated by high power switches with only turn-on capacity and, therefore, discharge the total energy stored in the capacitor bank. These pulses have a sudden onset and, therefore, a high rate of rising but have a very slow decay, which yields extra heat, which is ineffective in microbial inactivation. Square pulses can be produced by an incomplete discharge of a capacitor with the help of a switch having both on/off control or by using a pulse forming network. In this work, a pulsed power-based system is designed with the help of high voltage capacitors and solid-state switches (IGBT) for the inactivation of pathogenic micro-organism in liquid food such as fruit juices. The high voltage generator is based on the Marx generator topology, which can produce variable amplitude, frequency, and pulse width according to the requirements. Liquid food is treated in a chamber where pulsed electric field is produced between stainless steel electrodes using the pulsed output voltage of the supply. Preliminary bacterial inactivation tests were performed by subjecting orange juice inoculated with Escherichia Coli bacteria. With the help of the developed pulsed power source and the chamber, the inoculated orange has been PEF treated. The voltage was varied to get a peak electric field up to 15kV/cm. For a total treatment time of 200µs, a 30% reduction in the bacterial count has been observed. The detailed results and analysis will be presented in the final paper.

Keywords: Escherichia coli bacteria, high voltage generator, microbial inactivation, pulsed electric field, pulsed forming line, solid-state switch

Procedia PDF Downloads 160
135 Ethical Decision-Making by Healthcare Professionals during Disasters: Izmir Province Case

Authors: Gulhan Sen

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Disasters could result in many deaths and injuries. In these difficult times, accessible resources are limited, demand and supply balance is distorted, and there is a need to make urgent interventions. Disproportionateness between accessible resources and intervention capacity makes triage a necessity in every stage of disaster response. Healthcare professionals, who are in charge of triage, have to evaluate swiftly and make ethical decisions about which patients need priority and urgent intervention given the limited available resources. For such critical times in disaster triage, 'doing the greatest good for the greatest number of casualties' is adopted as a code of practice. But there is no guide for healthcare professionals about ethical decision-making during disasters, and this study is expected to use as a source in the preparation of the guide. This study aimed to examine whether the qualities healthcare professionals in Izmir related to disaster triage were adequate and whether these qualities influence their capacity to make ethical decisions. The researcher used a survey developed for data collection. The survey included two parts. In part one, 14 questions solicited information about socio-demographic characteristics and knowledge levels of the respondents on ethical principles of disaster triage and allocation of scarce resources. Part two included four disaster scenarios adopted from existing literature and respondents were asked to make ethical decisions in triage based on the provided scenarios. The survey was completed by 215 healthcare professional working in Emergency-Medical Stations, National Medical Rescue Teams and Search-Rescue-Health Teams in Izmir. The data was analyzed with SPSS software. Chi-Square Test, Mann-Whitney U Test, Kruskal-Wallis Test and Linear Regression Analysis were utilized. According to results, it was determined that 51.2% of the participants had inadequate knowledge level of ethical principles of disaster triage and allocation of scarce resources. It was also found that participants did not tend to make ethical decisions on four disaster scenarios which included ethical dilemmas. They stayed in ethical dilemmas that perform cardio-pulmonary resuscitation, manage limited resources and make decisions to die. Results also showed that participants who had more experience in disaster triage teams, were more likely to make ethical decisions on disaster triage than those with little or no experience in disaster triage teams(p < 0.01). Moreover, as their knowledge level of ethical principles of disaster triage and allocation of scarce resources increased, their tendency to make ethical decisions also increased(p < 0.001). In conclusion, having inadequate knowledge level of ethical principles and being inexperienced affect their ethical decision-making during disasters. So results of this study suggest that more training on disaster triage should be provided on the areas of the pre-impact phase of disaster. In addition, ethical dimension of disaster triage should be included in the syllabi of the ethics classes in the vocational training for healthcare professionals. Drill, simulations, and board exercises can be used to improve ethical decision making abilities of healthcare professionals. Disaster scenarios where ethical dilemmas are faced should be prepared for such applied training programs.

Keywords: disaster triage, medical ethics, ethical principles of disaster triage, ethical decision-making

Procedia PDF Downloads 229
134 Outcomes of Pregnancy in Women with TPO Positive Status after Appropriate Dose Adjustments of Thyroxin: A Prospective Cohort Study

Authors: Revathi S. Rajan, Pratibha Malik, Nupur Garg, Smitha Avula, Kamini A. Rao

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This study aimed to analyse the pregnancy outcomes in patients with TPO positivity after appropriate L-Thyroxin supplementation with close surveillance. All pregnant women attending the antenatal clinic at Milann-The Fertility Center, Bangalore, India- from Aug 2013 to Oct 2014 whose booking TSH was more than 2.5 mIU/L were included along with those pregnant women with prior hypothyroidism who were TPO positive. Those with TPO positive status were vigorously managed with appropriate thyroxin supplementation and the doses were readjusted every 3 to 4 weeks until delivery. Women with recurrent pregnancy loss were also tested for TPO positivity and if tested positive, were monitored serially with TSH and fT4 levels every 3 to 4 weeks and appropriately supplemented with thyroxin when the levels fluctuated. The testing was done after an informed consent in all these women. The statistical software namely SAS 9.2, SPSS 15.0, Stata 10.1, MedCalc 9.0.1, Systat 12.0 and R environment ver.2.11.1 were used for the analysis of the data. 460 pregnant women were screened for thyroid dysfunction at booking of which 52% were hypothyroid. Majority of them (31.08%) were subclinically hypothyroid and the remaining were overt. 25% of the total no. of patients screened were TPO positive. The various pregnancy complications that were observed in the TPO positive women were gestational glucose intolerance [60%], threatened abortion [21%], midtrimester abortion [4.3%], premature rupture of membranes [4.3%], cervical funneling [4.3%] and fetal growth restriction [3.5%]. 95.6% of the patients who followed up till the end delivered beyond 30 weeks. 42.6% of these patients had previous history of recurrent abortions or adverse obstetric outcome and 21.7% of the delivered babies required NICU admission. Obstetric outcomes in our study in terms of midtrimester abortions, placental abruption, and preterm delivery improved for the better after close monitoring of the thyroid hormone [TSH and fT4] levels every 3 to 4 weeks with appropriate dose adjustment throughout pregnancy. Euthyroid women with TPO positive status enrolled in the study incidentally were those with recurrent abortions/infertility and required thyroxin supplements due to elevated Thyroid hormone (TSH, fT4) levels during the course of their pregnancy. Significant associations were found with age>30 years and Hyperhomocysteinemia [p=0.017], recurrent pregnancy loss or previous adverse obstetric outcomes [p=0.067] and APLA [p=0.029]. TPO antibody levels >600 I U/ml were significantly associated with development of gestational hypertension [p=0.041] and fetal growth restriction [p=0.082]. Euthyroid women with TPO positivity were also screened periodically to counter fluctuations of the thyroid hormone levels with appropriate thyroxin supplementation. Thus, early identification along with aggressive management of thyroid dysfunction and stratification of these patients based on their TPO status with appropriate thyroxin supplementation beginning in the first trimester will aid risk modulation and also help avert complications.

Keywords: TPO antibody, subclinical hypothyroidism, anti nuclear antibody, thyroxin

Procedia PDF Downloads 307
133 A Hybrid LES-RANS Approach to Analyse Coupled Heat Transfer and Vortex Structures in Separated and Reattached Turbulent Flows

Authors: C. D. Ellis, H. Xia, X. Chen

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Experimental and computational studies investigating heat transfer in separated flows have been of increasing importance over the last 60 years, as efforts are being made to understand and improve the efficiency of components such as combustors, turbines, heat exchangers, nuclear reactors and cooling channels. Understanding of not only the time-mean heat transfer properties but also the unsteady properties is vital for design of these components. As computational power increases, more sophisticated methods of modelling these flows become available for use. The hybrid LES-RANS approach has been applied to a blunt leading edge flat plate, utilising a structured grid at a moderate Reynolds number of 20300 based on the plate thickness. In the region close to the wall, the RANS method is implemented for two turbulence models; the one equation Spalart-Allmaras model and Menter’s two equation SST k-ω model. The LES region occupies the flow away from the wall and is formulated without any explicit subgrid scale LES modelling. Hybridisation is achieved between the two methods by the blending of the nearest wall distance. Validation of the flow was obtained by assessing the mean velocity profiles in comparison to similar studies. Identifying the vortex structures of the flow was obtained by utilising the λ2 criterion to identify vortex cores. The qualitative structure of the flow compared with experiments of similar Reynolds number. This identified the 2D roll up of the shear layer, breaking down via the Kelvin-Helmholtz instability. Through this instability the flow progressed into hairpin like structures, elongating as they advanced downstream. Proper Orthogonal Decomposition (POD) analysis has been performed on the full flow field and upon the surface temperature of the plate. As expected, the breakdown of POD modes for the full field revealed a relatively slow decay compared to the surface temperature field. Both POD fields identified the most energetic fluctuations occurred in the separated and recirculation region of the flow. Latter modes of the surface temperature identified these levels of fluctuations to dominate the time-mean region of maximum heat transfer and flow reattachment. In addition to the current research, work will be conducted in tracking the movement of the vortex cores and the location and magnitude of temperature hot spots upon the plate. This information will support the POD and statistical analysis performed to further identify qualitative relationships between the vortex dynamics and the response of the surface heat transfer.

Keywords: heat transfer, hybrid LES-RANS, separated and reattached flow, vortex dynamics

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132 Technological Challenges for First Responders in Civil Protection; the RESPOND-A Solution

Authors: Georgios Boustras, Cleo Varianou Mikellidou, Christos Argyropoulos

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Summer 2021 was marked by a number of prolific fires in the EU (Greece, Cyprus, France) as well as outside the EU (USA, Turkey, Israel). This series of dramatic events have stretched national civil protection systems and first responders in particular. Despite the introduction of National, Regional and International frameworks (e.g. rescEU), a number of challenges have arisen, not only related to climate change. RESPOND-A (funded by the European Commission by Horizon 2020, Contract Number 883371) introduces a unique five-tier project architectural structure for best associating modern telecommunications technology with novel practices for First Responders of saving lives, while safeguarding themselves, more effectively and efficiently. The introduced architecture includes Perception, Network, Processing, Comprehension, and User Interface layers, which can be flexibly elaborated to support multiple levels and types of customization, so, the intended technologies and practices can adapt to any European Environment Agency (EEA)-type disaster scenario. During the preparation of the RESPOND-A proposal, some of our First Responder Partners expressed the need for an information management system that could boost existing emergency response tools, while some others envisioned a complete end-to-end network management system that would offer high Situational Awareness, Early Warning and Risk Mitigation capabilities. The intuition behind these needs and visions sits on the long-term experience of these Responders, as well, their smoldering worry that the evolving threat of climate change and the consequences of industrial accidents will become more frequent and severe. Three large-scale pilot studies are planned in order to illustrate the capabilities of the RESPOND-A system. The first pilot study will focus on the deployment and operation of all available technologies for continuous communications, enhanced Situational Awareness and improved health and safety conditions for First Responders, according to a big fire scenario in a Wildland Urban Interface zone (WUI). An important issue will be examined during the second pilot study. Unobstructed communication in the form of the flow of information is severely affected during a crisis; the flow of information between the wider public, from the first responders to the public and vice versa. Call centers are flooded with requests and communication is compromised or it breaks down on many occasions, which affects in turn – the effort to build a common operations picture for all firstr esponders. At the same time the information that reaches from the public to the operational centers is scarce, especially in the aftermath of an incident. Understandably traffic if disrupted leaves no other way to observe but only via aerial means, in order to perform rapid area surveys. Results and work in progress will be presented in detail and challenges in relation to civil protection will be discussed.

Keywords: first responders, safety, civil protection, new technologies

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131 Life Cycle Assessment of Todays and Future Electricity Grid Mixes of EU27

Authors: Johannes Gantner, Michael Held, Rafael Horn, Matthias Fischer

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At the United Nations Climate Change Conference 2015 a global agreement on the reduction of climate change was achieved stating CO₂ reduction targets for all countries. For instance, the EU targets a reduction of 40 percent in emissions by 2030 compared to 1990. In order to achieve this ambitious goal, the environmental performance of the different European electricity grid mixes is crucial. First, the electricity directly needed for everyone’s daily life (e.g. heating, plug load, mobility) and therefore a reduction of the environmental impacts of the electricity grid mix reduces the overall environmental impacts of a country. Secondly, the manufacturing of every product depends on electricity. Thereby a reduction of the environmental impacts of the electricity mix results in a further decrease of environmental impacts of every product. As a result, the implementation of the two-degree goal highly depends on the decarbonization of the European electricity mixes. Currently the production of electricity in the EU27 is based on fossil fuels and therefore bears a high GWP impact per kWh. Due to the importance of the environmental impacts of the electricity mix, not only today but also in future, within the European research projects, CommONEnergy and Senskin, time-dynamic Life Cycle Assessment models for all EU27 countries were set up. As a methodology, a combination of scenario modeling and life cycle assessment according to ISO14040 and ISO14044 was conducted. Based on EU27 trends regarding energy, transport, and buildings, the different national electricity mixes were investigated taking into account future changes such as amount of electricity generated in the country, change in electricity carriers, COP of the power plants and distribution losses, imports and exports. As results, time-dynamic environmental profiles for the electricity mixes of each country and for Europe overall were set up. Thereby for each European country, the decarbonization strategies of the electricity mix are critically investigated in order to identify decisions, that can lead to negative environmental effects, for instance on the reduction of the global warming of the electricity mix. For example, the withdrawal of the nuclear energy program in Germany and at the same time compensation of the missing energy by non-renewable energy carriers like lignite and natural gas is resulting in an increase in global warming potential of electricity grid mix. Just after two years this increase countervailed by the higher share of renewable energy carriers such as wind power and photovoltaic. Finally, as an outlook a first qualitative picture is provided, illustrating from environmental perspective, which country has the highest potential for low-carbon electricity production and therefore how investments in a connected European electricity grid could decrease the environmental impacts of the electricity mix in Europe.

Keywords: electricity grid mixes, EU27 countries, environmental impacts, future trends, life cycle assessment, scenario analysis

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130 Syntheses of Anionic Poly(urethanes) with Imidazolium, Phosphonium, and Ammonium as Counter-cations and Their Evaluation for CO2 Separation

Authors: Franciele L. Bernard, Felipe Dalla Vecchia, Barbara B. Polesso, Jose A. Donato, Marcus Seferin, Rosane Ligabue, Jailton F. do Nascimento, Sandra Einloft

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The increasing level of carbon dioxide concentration in the atmosphere related to fossil fuels processing and utilization are contributing to global warming phenomena considerably. Carbon capture and storage (CCS) technologies appear as one of the key technologies to reduce CO2 emissions mitigating the effects of climate change. Absorption using amines solutions as solvents have been extensively studied and used in industry for decades. However, solvent degradation and equipment corrosion are two of the main problems in this process. Poly (ionic liquid) (PIL) is considered as a promising material for CCS technology, potentially more environmentally friendly and lesser energy demanding than traditional material. PILs possess a unique combination of ionic liquids (ILs) features, such as affinity for CO2, thermal and chemical stability and adjustable properties, coupled with the intrinsic properties of the polymer. This study investigated new Poly (ionic liquid) (PIL) based on polyurethanes with different ionic liquids cations and its potential for CO2 capture. The PILs were synthesized by the addition of diisocyante to a difunctional polyol, followed by an exchange reaction with the ionic Liquids 1-butyl-3-methylimidazolium chloride (BMIM Cl); tetrabutylammonium bromide (TBAB) and tetrabutylphosphonium bromide (TBPB). These materials were characterized by Fourier transform infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance (1H-NMR), Atomic force microscopy (AFM), Tensile strength analysis, Field emission scanning electron microscopy (FESEM), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC). The PILs CO2 sorption capacity were gravimetrically assessed in a Magnetic Suspension Balance (MSB). It was found that the ionic liquids cation influences in the compounds properties as well as in the CO2 sorption. The best result for CO2 sorption (123 mgCO2/g at 30 bar) was obtained for the PIL (PUPT-TBA). The higher CO2 sorption in PUPT-TBA is probably linked to the fact that the tetraalkylammonium cation having a higher positive density charge can have a stronger interaction with CO2, while the imidazolium charge is delocalized. The comparative CO2 sorption values of the PUPT-TBA with different ionic liquids showed that this material has greater capacity for capturing CO2 when compared to the ILs even at higher temperature. This behavior highlights the importance of this study, as the poly (urethane) based PILs are cheap and versatile materials.

Keywords: capture, CO2, ionic liquids, ionic poly(urethane)

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129 The Effect of Lead(II) Lone Electron Pair and Non-Covalent Interactions on the Supramolecular Assembly and Fluorescence Properties of Pb(II)-Pyrrole-2-Carboxylato Polymer

Authors: M. Kowalik, J. Masternak, K. Kazimierczuk, O. V. Khavryuchenko, B. Kupcewicz, B. Barszcz

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Recently, the growing interest of chemists in metal-organic coordination polymers (MOCPs) is primarily derived from their intriguing structures and potential applications in catalysis, gas storage, molecular sensing, ion exchanges, nonlinear optics, luminescence, etc. Currently, we are devoting considerable effort to finding the proper method of synthesizing new coordination polymers containing S- or N-heteroaromatic carboxylates as linkers and characterizing the obtained Pb(II) compounds according to their structural diversity, luminescence, and thermal properties. The choice of Pb(II) as the central ion of MOCPs was motivated by several reasons mentioned in the literature: i) a large ionic radius allowing for a wide range of coordination numbers, ii) the stereoactivity of the 6s2 lone electron pair leading to a hemidirected or holodirected geometry, iii) a flexible coordination environment, and iv) the possibility to form secondary bonds and unusual non-covalent interactions, such as classic hydrogen bonds and π···π stacking interactions, as well as nonconventional hydrogen bonds and rarely reported tetrel bonds, Pb(lone pair)···π interactions, C–H···Pb agostic-type interactions or hydrogen bonds, and chelate ring stacking interactions. Moreover, the construction of coordination polymers requires the selection of proper ligands acting as linkers, because we are looking for materials exhibiting different network topologies and fluorescence properties, which point to potential applications. The reaction of Pb(NO₃)₂ with 1H-pyrrole-2-carboxylic acid (2prCOOH) leads to the formation of a new four-nuclear Pb(II) polymer, [Pb4(2prCOO)₈(H₂O)]ₙ, which has been characterized by CHN, FT-IR, TG, PL and single-crystal X-ray diffraction methods. In view of the primary Pb–O bonds, Pb1 and Pb2 show hemidirected pentagonal pyramidal geometries, while Pb2 and Pb4 display hemidirected octahedral geometries. The topology of the strongest Pb–O bonds was determined as the (4·8²) fes topology. Taking the secondary Pb–O bonds into account, the coordination number of Pb centres increased, Pb1 exhibited a hemidirected monocapped pentagonal pyramidal geometry, Pb2 and Pb4 exhibited a holodirected tricapped trigonal prismatic geometry, and Pb3 exhibited a holodirected bicapped trigonal prismatic geometry. Moreover, the Pb(II) lone pair stereoactivity was confirmed by DFT calculations. The 2D structure was expanded into 3D by the existence of non-covalent O/C–H···π and Pb···π interactions, which was confirmed by the Hirshfeld surface analysis. The above mentioned interactions improve the rigidity of the structure and facilitate the charge and energy transfer between metal centres, making the polymer a promising luminescent compound.

Keywords: coordination polymers, fluorescence properties, lead(II), lone electron pair stereoactivity, non-covalent interactions

Procedia PDF Downloads 135
128 Designing Short-Term Study Abroad Programs for Graduate Students: The Case of Morocco

Authors: Elaine Crable, Amit Sen

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Short-term study abroad programs have become a mainstay of MBA programs. The benefits of international business experiences, along with its exposure to global cultures, are well documented. However, developing a rewarding study, abroad program at the graduate level can be challenging for Faculty, especially when devising such a program for a group of part-time MBA students who come with a wide range of experiences and demographic characteristics. Each student has individual expectations for the study abroad experience. This study provides suggestions and considerations for Faculty that are planning to design a short-term study abroad program, especially for part-time MBA students. Insights are based on a recent experience leading a group of twenty-one students on a ten-day program to Morocco. The trip was designed and facilitated by two faculty members and a local Moroccan facilitator. This experience led to a number of insights and recommendations. First, the choice of location is critical. The choice of Morocco was very deliberate, owing to its multi-faceted cultural landscape and international business interest. It is an Islamic State with close ties to Europe both culturally and geographically and Morocco is a multi-lingual country with some combination of three languages spoken by most – English, Arabic, and French. Second, collaboration with a local ‘academic’ partner allowed the level of instruction to be both rigorous and significantly more engaging. Third, allowing students to participate in the planning of the trip enabled the trip participants to collaborate, negotiate, and share their own experiences and strengths. The pre-trip engagement was structured by creating four sub-groups, each responsible for an assigned city. Each student sub-group had to provide a historical background of the assigned city, plan the itinerary including sites to visit, cuisine to experience, industries to explore, markets to visit, plus provide a budget for that city’s expenses. The pre-planning segment of the course was critical for the success of the program as students were able to contribute to the design of the program through collaboration and negotiation with their peers. Fourth, each student sub-group was assigned industry to study within Morocco. The student sub-group prepared a presentation and a group paper with their analysis of the chosen industries. The pre-planning activities created strong bonds among the trip participants, which was evident when faced with on-ground challenges, especially when it was necessary to quickly evacuate due to a surprise USA COVID evacuation notice. The entire group supported each other when quickly making their way back to the United States. Unfortunately, the trip was cut short by two days due to this emergency exit, but the feedback regarding the program was very positive all around. While the program design put pressure on the Faculty leads regarding planning and coordination upfront, the outcome in terms of student engagement, student learning, collaboration and negotiation were all favorable and worth the effort. Finally, an added value, the cost of the program for the student was significantly lower compared to running a program with a professional provider.

Keywords: business education, experiential learning, international education, study abroad

Procedia PDF Downloads 154
127 Virtual Reality Applications for Building Indoor Engineering: Circulation Way-Finding

Authors: Atefeh Omidkhah Kharashtomi, Rasoul Hedayat Nejad, Saeed Bakhtiyari

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Circulation paths and indoor connection network of the building play an important role both in the daily operation of the building and during evacuation in emergency situations. The degree of legibility of the paths for navigation inside the building has a deep connection with the perceptive and cognitive system of human, and the way the surrounding environment is being perceived. Human perception of the space is based on the sensory systems in a three-dimensional environment, and non-linearly, so it is necessary to avoid reducing its representations in architectural design as a two-dimensional and linear issue. Today, the advances in the field of virtual reality (VR) technology have led to various applications, and architecture and building science can benefit greatly from these capabilities. Especially in cases where the design solution requires a detailed and complete understanding of the human perception of the environment and the behavioral response, special attention to VR technologies could be a priority. Way-finding in the indoor circulation network is a proper example for such application. Success in way-finding could be achieved if human perception of the route and the behavioral reaction have been considered in advance and reflected in the architectural design. This paper discusses the VR technology applications for the way-finding improvements in indoor engineering of the building. In a systematic review, with a database consisting of numerous studies, firstly, four categories for VR applications for circulation way-finding have been identified: 1) data collection of key parameters, 2) comparison of the effect of each parameter in virtual environment versus real world (in order to improve the design), 3) comparing experiment results in the application of different VR devices/ methods with each other or with the results of building simulation, and 4) training and planning. Since the costs of technical equipment and knowledge required to use VR tools lead to the limitation of its use for all design projects, priority buildings for the use of VR during design are introduced based on case-studies analysis. The results indicate that VR technology provides opportunities for designers to solve complex buildings design challenges in an effective and efficient manner. Then environmental parameters and the architecture of the circulation routes (indicators such as route configuration, topology, signs, structural and non-structural components, etc.) and the characteristics of each (metrics such as dimensions, proportions, color, transparency, texture, etc.) are classified for the VR way-finding experiments. Then, according to human behavior and reaction in the movement-related issues, the necessity of scenario-based and experiment design for using VR technology to improve the design and receive feedback from the test participants has been described. The parameters related to the scenario design are presented in a flowchart in the form of test design, data determination and interpretation, recording results, analysis, errors, validation and reporting. Also, the experiment environment design is discussed for equipment selection according to the scenario, parameters under study as well as creating the sense of illusion in the terms of place illusion, plausibility and illusion of body ownership.

Keywords: virtual reality (VR), way-finding, indoor, circulation, design

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126 Navigating States of Emergency: A Preliminary Comparison of Online Public Reaction to COVID-19 and Monkeypox on Twitter

Authors: Antonia Egli, Theo Lynn, Pierangelo Rosati, Gary Sinclair

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The World Health Organization (WHO) defines vaccine hesitancy as the postponement or complete denial of vaccines and estimates a direct linkage to approximately 1.5 million avoidable deaths annually. This figure is not immune to public health developments, as has become evident since the global spread of COVID-19 from Wuhan, China in early 2020. Since then, the proliferation of influential, but oftentimes inaccurate, outdated, incomplete, or false vaccine-related information on social media has impacted hesitancy levels to a degree described by the WHO as an infodemic. The COVID-19 pandemic and related vaccine hesitancy levels have in 2022 resulted in the largest drop in childhood vaccinations of the 21st century, while the prevalence of online stigma towards vaccine hesitant consumers continues to grow. Simultaneously, a second disease has risen to global importance: Monkeypox is an infection originating from west and central Africa and, due to racially motivated online hate, was in August 2022 set to be renamed by the WHO. To better understand public reactions towards two viral infections that became global threats to public health no two years apart, this research examines user replies to threads published by the WHO on Twitter. Replies to two Tweets from the @WHO account declaring COVID-19 and Monkeypox as ‘public health emergencies of international concern’ on January 30, 2020, and July 23, 2022, are gathered using the Twitter application programming interface and user mention timeline endpoint. Research methodology is unique in its analysis of stigmatizing, racist, and hateful content shared on social media within the vaccine discourse over the course of two disease outbreaks. Three distinct analyses are conducted to provide insight into (i) the most prevalent topics and sub-topics among user reactions, (ii) changes in sentiment towards the spread of the two diseases, and (iii) the presence of stigma, racism, and online hate. Findings indicate an increase in hesitancy to accept further vaccines and social distancing measures, the presence of stigmatizing content aimed primarily at anti-vaccine cohorts and racially motivated abusive messages, and a prevalent fatigue towards disease-related news overall. This research provides value to non-profit organizations or government agencies associated with vaccines and vaccination programs in emphasizing the need for public health communication fitted to consumers' vaccine sentiments, levels of health information literacy, and degrees of trust towards public health institutions. Considering the importance of addressing fears among the vaccine hesitant, findings also illustrate the risk of alienation through stigmatization, lead future research in probing the relatively underexamined field of online, vaccine-related stigma, and discuss the potential effects of stigma towards vaccine hesitant Twitter users in their decisions to vaccinate.

Keywords: social marketing, social media, public health communication, vaccines

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125 Comparison of Two Methods of Cryopreservation of Testicular Tissue from Prepubertal Lambs

Authors: Rensson Homero Celiz Ygnacio, Marco Aurélio Schiavo Novaes, Lucy Vanessa Sulca Ñaupas, Ana Paula Ribeiro Rodrigues

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The cryopreservation of testicular tissue emerges as an alternative for the preservation of the reproductive potential of individuals who still cannot produce sperm; however, they will undergo treatments that may affect their fertility (e.g., chemotherapy). Therefore, the present work aims to compare two cryopreservation methods (slow freezing and vitrification) in testicular tissue of prepubertal lambs. For that, to obtain the testicular tissue, the animals were castrated and the testicles were collected immediately in a physiological solution supplemented with antibiotics. In the laboratory, the testis was split into small pieces. The total size of the testicular fragments was 3×3x1 mm³ and was placed in a dish contained in Minimum Essential Medium (MEM-HEPES). The fragments were distributed randomly into non-cryopreserved (fresh control), slow freezing (SF), and vitrified. To SF procedures, two fragments from a given male were then placed in a 2,0 mL cryogenic vial containing 1,0 mL MEM-HEPES supplemented with 20% fetal bovine serum (FBS) and 20% dimethylsulfoxide (DMSO). Tubes were placed into a Mr. Frosty™ Freezing container with isopropyl alcohol and transferred to a -80°C freezer for overnight storage. On the next day, each tube was plunged into liquid nitrogen (NL). For vitrification, the ovarian tissue cryosystem (OTC) device was used. Testicular fragments were placed in the OTC device and exposed to the first vitrification solution composed of MEM-HEPES supplemented with 10 mg/mL Bovine Serum Albumin (BSA), 0.25 M sucrose, 10% Ethylene glycol (EG), 10% DMSO and 150 μM alpha-lipoic acid for four min. The VS1 was discarded and then the fragments were submerged into a second vitrification solution (VS2) containing the same composition of VS1 but 20% EG and 20% DMSO. VS2 was then discarded and each OTC device containing up to four testicular fragments was closed and immersed in NL. After the storage period, the fragments were removed from the NL, kept at room temperature for one min and then immersed at 37 °C in a water bath for 30 s. Samples were warmed by sequentially immersing in solutions of MEM-HEPES supplemented with 3 mg/mL BSA and decreasing concentrations of sucrose. Hematoxylin-eosin staining to analyze the tissue architecture was used. The score scale used was from 0 to 3, classified with a score 0 representing normal morphologically, and 3 were considered a lot of alteration. The histomorphological evaluation of the testicular tissue shows that when evaluating the nuclear alteration (distinction of nucleoli and condensation of nuclei), there are no differences when using slow freezing with respect to the control. However, vitrification presents greater damage (p <0.05). On the other hand, when evaluating the epithelial alteration, we observed that the freezing showed scores statistically equal to the control in variables such as retraction of the basement membrane, formation of gaps and organization of the peritubular cells. The results of the study demonstrated that cryopreservation using the slow freezing method is an excellent tool for the preservation of pubertal testicular tissue.

Keywords: cryopreservation, slow freezing, vitrification, testicular tissue, lambs

Procedia PDF Downloads 154
124 Early Biological Effects in Schoolchildren Living in an Area of Salento (Italy) with High Incidence of Chronic Respiratory Diseases: The IMP.AIR. Study

Authors: Alessandra Panico, Francesco Bagordo, Tiziana Grassi, Adele Idolo, Marcello Guido, Francesca Serio, Mattia De Giorgi, Antonella De Donno

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In the Province of Lecce (Southeastern Italy) an area with unusual high incidence of chronic respiratory diseases, including lung cancer, was recently identified. The causes of this health emergency are still not entirely clear. In order to determine the risk profile of children living in five municipalities included in this area an epidemiological-molecular study was performed in the years 2014-2016: the IMP.AIR. (Impact of air quality on health of residents in the Municipalities of Sternatia, Galatina, Cutrofiano, Sogliano Cavour and Soleto) study. 122 children aged 6-8 years attending primary school in the study area were enrolled to evaluate the frequency of micronuclei (MNs) in their buccal exfoliated cells. The samples were collected in May 2015 by rubbing the oral mucosa with a soft bristle disposable toothbrush. At the same time, a validated questionnaire was administered to parents to obtain information about health, lifestyle and eating habits of the children. In addition, information on airborne pollutants, routinely detected by the Regional Environmental Agency (ARPA Puglia) in the study area, was acquired. A multivariate analysis was performed to detect any significant association between frequency of MNs (dependent variable) and behavioral factors (independent variables). The presence of MNs was highlighted in the buccal exfoliated cells of about 42% of recruited children with a mean frequency of 0.49 MN/1000 cells, greater than in other areas of Salento. The survey on individual characteristics and lifestyles showed that one in three children was overweight and that most of them had unhealthy eating habits with frequent consumption of foods considered ‘risky’. Moreover many parents (40% of fathers and 12% of mothers) were smokers and about 20% of them admitted to smoking in the house where the children lived. Information regarding atmospheric contaminants was poor. Of the few substances routinely detected by the only one monitoring station located in the study area (PM2.5, SO2, NO2, CO, O3) only ozone showed high concentrations exceeding the limits set by the legislation for 67 times in the year 2015. The study showed that the level of early biological effect markers in children was not negligible. This critical condition could be related to some individual factors and lifestyles such as overweight, unhealthy eating habits and exposure to passive smoking. At present, no relationship with airborne pollutants can be established due to the lack of information on many substances. Therefore, it would be advisable to modify incorrect behaviors and to intensify the monitoring of airborne pollutants (e.g. including detection of PM10, heavy metals, aromatic polycyclic hydrocarbons, benzene) given the epidemiology of chronic respiratory diseases registered in this area.

Keywords: chronic respiratory diseases, environmental pollution, lifestyle, micronuclei

Procedia PDF Downloads 186
123 Simultaneous Optimization of Design and Maintenance through a Hybrid Process Using Genetic Algorithms

Authors: O. Adjoul, A. Feugier, K. Benfriha, A. Aoussat

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In general, issues related to design and maintenance are considered in an independent manner. However, the decisions made in these two sets influence each other. The design for maintenance is considered an opportunity to optimize the life cycle cost of a product, particularly in the nuclear or aeronautical field, where maintenance expenses represent more than 60% of life cycle costs. The design of large-scale systems starts with product architecture, a choice of components in terms of cost, reliability, weight and other attributes, corresponding to the specifications. On the other hand, the design must take into account maintenance by improving, in particular, real-time monitoring of equipment through the integration of new technologies such as connected sensors and intelligent actuators. We noticed that different approaches used in the Design For Maintenance (DFM) methods are limited to the simultaneous characterization of the reliability and maintainability of a multi-component system. This article proposes a method of DFM that assists designers to propose dynamic maintenance for multi-component industrial systems. The term "dynamic" refers to the ability to integrate available monitoring data to adapt the maintenance decision in real time. The goal is to maximize the availability of the system at a given life cycle cost. This paper presents an approach for simultaneous optimization of the design and maintenance of multi-component systems. Here the design is characterized by four decision variables for each component (reliability level, maintainability level, redundancy level, and level of monitoring data). The maintenance is characterized by two decision variables (the dates of the maintenance stops and the maintenance operations to be performed on the system during these stops). The DFM model helps the designers choose technical solutions for the large-scale industrial products. Large-scale refers to the complex multi-component industrial systems and long life-cycle, such as trains, aircraft, etc. The method is based on a two-level hybrid algorithm for simultaneous optimization of design and maintenance, using genetic algorithms. The first level is to select a design solution for a given system that considers the life cycle cost and the reliability. The second level consists of determining a dynamic and optimal maintenance plan to be deployed for a design solution. This level is based on the Maintenance Free Operating Period (MFOP) concept, which takes into account the decision criteria such as, total reliability, maintenance cost and maintenance time. Depending on the life cycle duration, the desired availability, and the desired business model (sales or rental), this tool provides visibility of overall costs and optimal product architecture.

Keywords: availability, design for maintenance (DFM), dynamic maintenance, life cycle cost (LCC), maintenance free operating period (MFOP), simultaneous optimization

Procedia PDF Downloads 98
122 The Human Rights Implications of Arbitrary Arrests and Political Imprisonment in Cameroon between 2016 and 2019

Authors: Ani Eda Njwe

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Cameroon is a bilingual and bijural country in West and Central Africa. The current president has been in power since 1982, which makes him the longest-serving president in the world. The length of his presidency is one of the major causes of the ongoing political instability in the country. The preamble of the Cameroonian constitution commits Cameroon to respect international law and human rights. It provides that these laws should be translated into national laws, and respected by all spheres of government and public service. Cameroon is a signatory of several international human rights laws and conventions. In theory, the citizens of Cameroon have adequate legal protection against the violation of their human rights for political reasons. The ongoing political crisis in Cameroon erupted after the Anglophone lawyers and teachers launched a protest against the hiring of Francophone judges in Anglophone courts; and the hiring of Francophone teachers in Anglophone schools. In retaliation, the government launched a military crackdown on protesters and civilians, conducted arbitrary arrests on Anglophones, raped and maimed civilians, and declared a state of emergency in the Anglophone provinces. This infuriated the Anglophone public, causing them to create a secessionist movement, requesting the Independence of Anglophone Cameroon and demanding a separate country called Ambazonia. The Ambazonian armed rebel forces have ever since launched guerrilla attacks on government troops. This fighting has deteriorated into a war between the Ambazonians and the Cameroon government. The arbitrary arrests and unlawful imprisonments have continued, causing the closure of Anglophone schools since November 2016. In October 2018, Cameroon held presidential elections. Before the electoral commission announced the results, the opposition leader, a Francophone, declared himself winner, following a leak of the polling information. This led to his imprisonment. This research has the objective of finding out whether the government’s reactions to protesters and opposition is lawful, under national and international laws. This research will also verify if the prison conditions of political prisoners meet human rights standards. Furthermore, this research seeks detailed information obtained from current political prisoners and detainees on their experiences. This research also aims to highlight the effort being made internationally, towards bringing awareness and finding a resolution to the war in Cameroon. Finally, this research seeks to elucidate on the efforts which human rights organisations have made, towards overseeing the respect of human rights in Cameroon. This research adopts qualitative methods, whereby data were collected using semi-structured interviews of political detainees, and questionnaires. Also, data was collected from secondary sources such as; scholarly articles, newspaper articles, web sources, and human rights reports. From the data collected, the findings were analysed using the content analysis research technique. From the deductions, recommendations have been made, which human rights organisations, activists, and international bodies can implement, to cause the Cameroonian government to stop unlawful arrests and reinstate the respect of human rights and the rule of law in Cameroon.

Keywords: arbitrary arrests, Cameroon, human rights, political

Procedia PDF Downloads 96
121 Phantom and Clinical Evaluation of Block Sequential Regularized Expectation Maximization Reconstruction Algorithm in Ga-PSMA PET/CT Studies Using Various Relative Difference Penalties and Acquisition Durations

Authors: Fatemeh Sadeghi, Peyman Sheikhzadeh

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Introduction: Block Sequential Regularized Expectation Maximization (BSREM) reconstruction algorithm was recently developed to suppress excessive noise by applying a relative difference penalty. The aim of this study was to investigate the effect of various strengths of noise penalization factor in the BSREM algorithm under different acquisition duration and lesion sizes in order to determine an optimum penalty factor by considering both quantitative and qualitative image evaluation parameters in clinical uses. Materials and Methods: The NEMA IQ phantom and 15 clinical whole-body patients with prostate cancer were evaluated. Phantom and patients were injected withGallium-68 Prostate-Specific Membrane Antigen(68 Ga-PSMA)and scanned on a non-time-of-flight Discovery IQ Positron Emission Tomography/Computed Tomography(PET/CT) scanner with BGO crystals. The data were reconstructed using BSREM with a β-value of 100-500 at an interval of 100. These reconstructions were compared to OSEM as a widely used reconstruction algorithm. Following the standard NEMA measurement procedure, background variability (BV), recovery coefficient (RC), contrast recovery (CR) and residual lung error (LE) from phantom data and signal-to-noise ratio (SNR), signal-to-background ratio (SBR) and tumor SUV from clinical data were measured. Qualitative features of clinical images visually were ranked by one nuclear medicine expert. Results: The β-value acts as a noise suppression factor, so BSREM showed a decreasing image noise with an increasing β-value. BSREM, with a β-value of 400 at a decreased acquisition duration (2 min/ bp), made an approximately equal noise level with OSEM at an increased acquisition duration (5 min/ bp). For the β-value of 400 at 2 min/bp duration, SNR increased by 43.7%, and LE decreased by 62%, compared with OSEM at a 5 min/bp duration. In both phantom and clinical data, an increase in the β-value is translated into a decrease in SUV. The lowest level of SUV and noise were reached with the highest β-value (β=500), resulting in the highest SNR and lowest SBR due to the greater noise reduction than SUV reduction at the highest β-value. In compression of BSREM with different β-values, the relative difference in the quantitative parameters was generally larger for smaller lesions. As the β-value decreased from 500 to 100, the increase in CR was 160.2% for the smallest sphere (10mm) and 12.6% for the largest sphere (37mm), and the trend was similar for SNR (-58.4% and -20.5%, respectively). BSREM visually was ranked more than OSEM in all Qualitative features. Conclusions: The BSREM algorithm using more iteration numbers leads to more quantitative accuracy without excessive noise, which translates into higher overall image quality and lesion detectability. This improvement can be used to shorter acquisition time.

Keywords: BSREM reconstruction, PET/CT imaging, noise penalization, quantification accuracy

Procedia PDF Downloads 79
120 Characterization of Main Phenolic Compounds in Eleusine indica L. (Poaceae) by HPLC-DAD and 1H NMR

Authors: E. M. Condori-Peñaloza, S. S. Costa

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Eleusine indica L, known as goose-grass, is considered a troublesome weed that can cause important economic losses in the agriculture worldwide. However, this grass is used as a medicinal plant in some regions of Brazil to treat influenza and pneumonia. In Africa and Asia, it is used to treat malaria and as diuretic, anti-helminthic, among other uses. Despite its therapeutic potential, little is known about the chemical composition and bioactive compounds of E. indica. Hitherto, two major flavonoids, schaftoside and vitexin, were isolated from aerial part of the species and showed inhibitory activity on lung neutrophil influxes in mice, suggesting a beneficial effect on airway inflammation. Therefore, the aim of this study was to analyze the chemical profile of aqueous extracts from aerial parts of Eleusine indica specimens using high performance liquid chromatography (HPLC-DAD) and 1H nuclear magnetic resonance spectroscopy (NMR), with emphasis on phenolic compounds. Specimens of E. indica were collected in Minas Gerais state, Brazil. Aerial parts of fresh plants were extracted by decoction (10% p/v). After spontaneous precipitation of the aqueous extract at 10-12°C for 24 hours, the supernatant obtained was frozen and lyophilized. After that, 1 g of the extract was dissolved into 25 mL of water and fractionated on a reverse phase chromatography column (RP-2), eluted with a gradient of H2O/EtOH. Five fractions were obtained. The extract and fractions had their chemical profile analyzed by using HPLC-DAD (C-18 column: 20 μL, 256 -365 nm; gradient water 0.01% phosphoric acid/ acetonitrile. The extract was also analyzed by NMR (1H, 500 MHz, D2O) in order to access its global chemical composition. HPLC-DAD analyses of crude extract allowed the identification of ten phenolic compounds. Fraction 1, eluted with 100% water, was poor in phenolic compounds and no major peak was detected. In fraction 2, eluted with 100% water, it was possible to observe one major peak at retention time (RT) of 23.75 minutes compatible with flavonoid; fraction 3, also eluted with 100% water, showed four peaks at RT= 21.47, 23.52, 24.33 and 25.84 minutes, all of them compatible with flavonoid. In fraction 4, eluted with 50%/ethanol/50% water, it was possible to observe 3 peaks compatible with flavonoids at RT=24.65, 26.81, 27.49 minutes, and one peak (28.83 min) compatible with a phenolic acid derivative. Finally, in fraction 5, eluted with 100% ethanol, no phenolic substance was detected. The UV spectra of all flavonoids detected were compatible with the flavone subclass (λ= 320-345 nm). The 1H NMR spectra of aerial parts extract showed signals in three regions: δ 0.8-3.0 ppm (aliphatic compounds), δ 3.0-5.5 ppm corresponding to carbohydrates (signals most abundant and overlapped), and δ 6.0-8.5 ppm (aromatic compounds). Signals compatible with flavonoids (rings A and B) could also be detected in the crude extract spectra. These results suggest the presence of several flavonoids in E. indica, which reinforces their therapeutic potential. The pharmacological activities of Eleusine indica extracts and fractions will be further evaluated.

Keywords: flavonoids, HPLC, NMR, phenolic compounds

Procedia PDF Downloads 302
119 Anti-DNA Antibodies from Patients with Schizophrenia Hydrolyze DNA

Authors: Evgeny A. Ermakov, Lyudmila P. Smirnova, Valentina N. Buneva

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Schizophrenia associated with dysregulation of neurotransmitter processes in the central nervous system and disturbances in the humoral immune system resulting in the formation of antibodies (Abs) to the various components of the nervous tissue. Abs to different neuronal receptors and DNA were detected in the blood of patients with schizophrenia. Abs hydrolyzing DNA were detected in pool of polyclonal autoantibodies in autoimmune and infectious diseases, such catalytic Abs were named abzymes. It is believed that DNA-hydrolyzing abzymes are cytotoxic, cause nuclear DNA fragmentation and induce cell death by apoptosis. Abzymes with DNAase activity are interesting because of the mechanism of formation and the possibility of use as diagnostic markers. Therefore, in our work we have set following goals: to determine the level anti-DNA Abs in the serum of patients with schizophrenia and to study DNA-hydrolyzing activity of IgG of patients with schizophrenia. Materials and methods: In our study there were included 41 patients with a verified diagnosis of paranoid or simple schizophrenia and 24 healthy donors. Electrophoretically and immunologically homogeneous IgGs were obtained by sequential affinity chromatography of the serum proteins on protein G-Sepharose and gel filtration. The levels of anti-DNA Abs were determined using ELISA. DNA-hydrolyzing activity was detected as the level of supercoiled pBluescript DNA transition in circular and linear forms, the hydrolysis products were analyzed by agarose electrophoresis followed by ethidium bromide stain. To correspond the registered catalytic activity directly to the antibodies we carried out a number of strict criteria: electrophoretic homogeneity of the antibodies, gel filtration (acid shock analysis) and in situ activity. Statistical analysis was performed in ‘Statistica 9.0’ using the non-parametric Mann-Whitney test. Results: The sera of approximately 30% of schizophrenia patients displayed a higher level of Abs interacting with single-stranded (ssDNA) and double-stranded DNA (dsDNA) compared with healthy donors. The average level of Abs interacting with ssDNA was only 1.1-fold lower than that for interacting with dsDNA. IgG of patient with schizophrenia were shown to possess DNA hydrolyzing activity. Using affinity chromatography, electrophoretic analysis of isolated IgG homogeneity, gel filtration in acid shock conditions and in situ DNAse activity analysis we proved that the observed activity is intrinsic property of studied antibodies. We have shown that the relative DNAase activity of IgG in patients with schizophrenia averaged 55.4±32.5%, IgG of healthy donors showed much lower activity (average of 9.1±6.5%). It should be noted that DNAase activity of IgG in patients with schizophrenia with a negative symptoms was significantly higher (73.3±23.8%), than in patients with positive symptoms (43.3±33.1%). Conclusion: Anti-DNA Abs of patients with schizophrenia not only bind DNA, but quite efficiently hydrolyze the substrate. The data show a correlation with the level of DNase activity and leading symptoms of patients with schizophrenia.

Keywords: anti-DNA antibodies, abzymes, DNA hydrolysis, schizophrenia

Procedia PDF Downloads 308
118 Lifting Body Concepts for Unmanned Fixed-Wing Transport Aircrafts

Authors: Anand R. Nair, Markus Trenker

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Lifting body concepts were conceived as early as 1917 and patented by Roy Scroggs. It was an idea of using the fuselage as a lift producing body with no or small wings. Many of these designs were developed and even flight tested between 1920’s to 1970’s, but it was not pursued further for commercial flight as at lower airspeeds, such a configuration was incapable to produce sufficient lift for the entire aircraft. The concept presented in this contribution is combining the lifting body design along with a fixed wing to maximise the lift produced by the aircraft. Conventional aircraft fuselages are designed to be aerodynamically efficient, which is to minimise the drag; however, these fuselages produce very minimal or negligible lift. For the design of an unmanned fixed wing transport aircraft, many of the restrictions which are present for commercial aircraft in terms of fuselage design can be excluded, such as windows for the passengers/pilots, cabin-environment systems, emergency exits, and pressurization systems. This gives new flexibility to design fuselages which are unconventionally shaped to contribute to the lift of the aircraft. The two lifting body concepts presented in this contribution are targeting different applications: For a fast cargo delivery drone, the fuselage is based on a scaled airfoil shape with a cargo capacity of 500 kg for euro pallets. The aircraft has a span of 14 m and reaches 1500 km at a cruising speed of 90 m/s. The aircraft could also easily be adapted to accommodate pilot and passengers with modifications to the internal structures, but pressurization is not included as the service ceiling envisioned for this type of aircraft is limited to 10,000 ft. The next concept to be investigated is called a multi-purpose drone, which incorporates a different type of lifting body and is a much more versatile aircraft as it will have a VTOL capability. The aircraft will have a wingspan of approximately 6 m and flight speeds of 60 m/s within the same service ceiling as the fast cargo delivery drone. The multi-purpose drone can be easily adapted for various applications such as firefighting, agricultural purposes, surveillance, and even passenger transport. Lifting body designs are not a new concept, but their effectiveness in terms of cargo transportation has not been widely investigated. Due to their enhanced lift producing capability, lifting body designs enable the reduction of the wing area and the overall weight of the aircraft. This will, in turn, reduce the thrust requirement and ultimately the fuel consumption. The various designs proposed in this contribution will be based on the general aviation category of aircrafts and will be focussed on unmanned methods of operation. These unmanned fixed-wing transport drones will feature appropriate cargo loading/unloading concepts which can accommodate large size cargo for efficient time management and ease of operation. The various designs will be compared in performance to their conventional counterpart to understand their benefits/shortcomings in terms of design, performance, complexity, and ease of operation. The majority of the performance analysis will be carried out using industry relevant standards in computational fluid dynamics software packages.

Keywords: lifting body concept, computational fluid dynamics, unmanned fixed-wing aircraft, cargo drone

Procedia PDF Downloads 218
117 Non-Timber Forest Products and Livelihood Linkages: A Case of Lamabagar, Nepal

Authors: Sandhya Rijal, Saroj Adhikari, Ramesh R. Pant

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Non-Timber Forest Products (NTFPs) have attracted substantial interest in the recent years with the increasing recognition that these can provide essential community needs for improved and diversified rural livelihood and support the objectives of biodiversity conservation. Nevertheless, various challenges are witnessed in their sustainable harvest and management. Assuming that sustainable management with community stewardship can offer one of the solutions to existing challenges, the study assesses the linkages between NTFPs and rural livelihood in Lamabagar village of Dolakha, Nepal. The major objective was to document the status of NTFPs and their contributions in households of Lamabagar. For status documentation, vegetation sampling was done using systematic random sampling technique. 30 plots of 10 m × 10 m were laid down in six parallel transect lines at horizontal distance of 160 m in two different community forests. A structured questionnaire survey was conducted in 76 households (excluding non-response rate) using stratified random sampling technique for contribution analysis. Likewise, key informant interview and focus group discussions were also conducted for data triangulations. 36 different NTFPs were recorded from the vegetation sample in two community forests of which 50% were used for medicinal purposes. The other uses include fodder, religious value, and edible fruits and vegetables. Species like Juniperus indica, Daphne bholua Aconitum spicatum, and Lyonia ovalifolia were frequently used for trade as a source of income, which was sold in local market. The protected species like Taxus wallichiana and Neopicrorhiza scrophulariiflora were also recorded in the area for which the trade is prohibited. The protection of these species urgently needs community stewardship. More than half of the surveyed households (55%) were depending on NTFPs for their daily uses, other than economic purpose whereas 45% of them sold those products in the market directly or in the form of local handmade products as a source of livelihood. NTFPs were the major source of primary health curing agents especially for the poor and unemployed people in the study area. Hence, the NTFPs contributed to livelihood under three different categories: subsistence, supplement income and emergency support, depending upon the economic status of the households. Although the status of forest improved after handover to the user group, the availability of valuable medicinal herbs like Rhododendron anthopogon, Swertia nervosa, Neopicrorhiza scrophulariiflora, and Aconitum spicatum were declining. Inadequacy of technology, lack of easy transport access, and absence of good market facility were the major limitations for external trade of NTFPs in the study site. It was observed that people were interested towards conservation only if they could get some returns: economic in terms of rural settlements. Thus, the study concludes that NTFPs could contribute rural livelihood and support conservation objectives only if local communities are provided with the easy access of technology, market and capital.

Keywords: contribution, medicinal, subsistence, sustainable harvest

Procedia PDF Downloads 111
116 The Incident of Concussion across Popular American Youth Sports: A Retrospective Review

Authors: Rami Hashish, Manon Limousis-Gayda, Caitlin H. McCleery

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Introduction: A leading cause of emergency room visits among youth (in the United States), is sports-related traumatic brain injuries. Mild traumatic brain injuries (mTBIs), also called concussions, are caused by linear and/or angular acceleration experienced at the head and represent an increasing societal burden. Due to the developing nature of the brain in youth, there is a great risk for long-term neuropsychological deficiencies following a concussion. Accordingly, the purpose of this paper is to investigate incidence rates of concussion across gender for the five most common youth sports in the United States. These include basketball, track and field, soccer, baseball (boys), softball (girls), football (boys), and volleyball (girls). Methods: A PubMed search was performed for four search themes combined. The first theme identified the outcomes (concussion, brain injuries, mild traumatic brain injury, etc.). The second theme identified the sport (American football, soccer, basketball, softball, volleyball, track, and field, etc.). The third theme identified the population (adolescence, children, youth, boys, girls). The last theme identified the study design (prevalence, frequency, incidence, prospective). Ultimately, 473 studies were surveyed, with 15 fulfilling the criteria: prospective study presenting original data and incidence of concussion in the relevant youth sport. The following data were extracted from the selected studies: population age, total study population, total athletic exposures (AE) and incidence rate per 1000 athletic exposures (IR/1000). Two One-Way ANOVA and a Tukey’s post hoc test were conducted using SPSS. Results: From the 15 selected studies, statistical analysis revealed the incidence of concussion per 1000 AEs across the considered sports ranged from 0.014 (girl’s track and field) to 0.780 (boy’s football). Average IR/1000 across all sports was 0.483 and 0.268 for boys and girls, respectively; this difference in IR was found to be statistically significant (p=0.013). Tukey’s post hoc test showed that football had significantly higher IR/1000 than boys’ basketball (p=0.022), soccer (p=0.033) and track and field (p=0.026). No statistical difference was found for concussion incidence between girls’ sports. Removal of football was found to lower the IR/1000 for boys without a statistical difference (p=0.101) compared to girls. Discussion: Football was the only sport showing a statistically significant difference in concussion incidence rate relative to other sports (within gender). Males were overall more likely to be concussed than females when football was included (1.8x), whereas concussion was more likely for females when football was excluded. While the significantly higher rate of concussion in football is not surprising because of the nature and rules of the sport, it is concerning that research has shown higher incidence of concussion in practices than games. Interestingly, findings indicate that girls’ sports are more concussive overall when football is removed. This appears to counter the common notion that boys’ sports are more physically taxing and dangerous. Future research should focus on understanding the concussive mechanisms of injury in each sport to enable effective rule changes.

Keywords: gender, football, soccer, traumatic brain injury

Procedia PDF Downloads 127
115 Operation System for Aluminium-Air Cell: A Strategy to Harvest the Energy from Secondary Aluminium

Authors: Binbin Chen, Dennis Y. C. Leung

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Aluminium (Al) -air cell holds a high volumetric capacity density of 8.05 Ah cm-3, benefit from the trivalence of Al ions. Additional benefits of Al-air cell are low price and environmental friendliness. Furthermore, the Al energy conversion process is characterized of 100% recyclability in theory. Along with a large base of raw material reserve, Al attracts considerable attentions as a promising material to be integrated within the global energy system. However, despite the early successful applications in military services, several problems exist that prevent the Al-air cells from widely civilian use. The most serious issue is the parasitic corrosion of Al when contacts with electrolyte. To overcome this problem, super-pure Al alloyed with various traces of metal elements are used to increase the corrosion resistance. Nevertheless, high-purity Al alloys are costly and require high energy consumption during production process. An alternative approach is to add inexpensive inhibitors directly into the electrolyte. However, such additives would increase the internal ohmic resistance and hamper the cell performance. So far these methods have not provided satisfactory solutions for the problem within Al-air cells. For the operation of alkaline Al-air cell, there are still other minor problems. One of them is the formation of aluminium hydroxide in the electrolyte. This process decreases ionic conductivity of electrolyte. Another one is the carbonation process within the gas diffusion layer of cathode, blocking the porosity of gas diffusion. Both these would hinder the performance of cells. The present work optimizes the above problems by building an Al-air cell operation system, consisting of four components. A top electrolyte tank containing fresh electrolyte is located at a high level, so that it can drive the electrolyte flow by gravity force. A mechanical rechargeable Al-air cell is fabricated with low-cost materials including low grade Al, carbon paper, and PMMA plates. An electrolyte waste tank with elaborate channel is designed to separate the hydrogen generated from the corrosion, which would be collected by gas collection device. In the first section of the research work, we investigated the performance of the mechanical rechargeable Al-air cell with a constant flow rate of electrolyte, to ensure the repeatability experiments. Then the whole system was assembled together and the feasibility of operating was demonstrated. During experiment, pure hydrogen is collected by collection device, which holds potential for various applications. By collecting this by-product, high utilization efficiency of aluminum is achieved. Considering both electricity and hydrogen generated, an overall utilization efficiency of around 90 % or even higher under different working voltages are achieved. Fluidic electrolyte could remove aluminum hydroxide precipitate and solve the electrolyte deterioration problem. This operation system provides a low-cost strategy for harvesting energy from the abundant secondary Al. The system could also be applied into other metal-air cells and is suitable for emergency power supply, power plant and other applications. The low cost feature implies great potential for commercialization. Further optimization, such as scaling up and optimization of fabrication, will help to refine the technology into practical market offerings.

Keywords: aluminium-air cell, high efficiency, hydrogen, mechanical recharge

Procedia PDF Downloads 264
114 New Insulation Material for Solar Thermal Collectors

Authors: Nabila Ihaddadene, Razika Ihaddadene, Abdelwahaab Betka

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1973 energy crisis (rising oil prices) pushed the world to consider other alternative energy resources to existing conventional energies consisting predominantly of hydrocarbons. Renewable energies such as solar, the wind and geothermal have received renewed interest, especially to preserve nature ( the low-temperature rise of global environmental problems). Solar energy as an available, cheap and environmental friendly alternative source has various applications such as heating, cooling, drying, power generation, etc. In short, there is no life on earth without this enormous nuclear reactor, called the sun. Among available solar collector designs, flat plate collector (FPC) is low-temperature applications (heating water, space heating, etc.) due to its simple design and ease of manufacturing. Flat plate collectors are permanently fixed in position and do not track the sun (non-concentrating collectors). They operate by converting solar radiation into heat and transferring that heat to a working fluid (usually air, water, water plus antifreeze additive) flowing through them. An FPC generally consists of the main following components: glazing, absorber plate of high absorptivity, fluid tubes welded to or can be an integral part of the absorber plate, insulation and container or casing of the above-mentioned components. Insulation is of prime importance in thermal applications. There are three main families of insulation: mineral insulation; vegetal insulation and synthetic organic insulation. The old houses of the inhabitants of North Africa were built of brick made of composite material that is clay and straw. These homes are characterized by their thermal comfort; i.e. the air inside these houses is cool in summer and warm in winter. So, the material composed from clay and straw act as a thermal insulation. In this research document, the polystyrene used as insulation in the ET200 flat plate solar collector is replaced by the cheapest natural material which is clay and straw. Trials were carried out on a solar energy demonstration system (ET 200). This system contains a solar collector, water storage tank, a high power lamp simulating solar energy and a control and command cabinet. In the experimental device, the polystyrene is placed under the absorber plate and in the edges of the casing containing the components of the solar collector. In this work, we have replaced the polystyrene of the edges by the composite material. The use of the clay and straw as insulation instead of the polystyrene increases temperature difference (T2-T1) between the inlet and the outlet of the absorber by 0.9°C; thus increases the useful power transmitted to water in the solar collector. Tank Water is well heated when using the clay and straw as insulation. However, it is less heated when using the polystyrene as insulation. Clay and straw material improves also the performance of the solar collector by 5.77%. Thus, it is recommended to use this cheapest non-polluting material instead of synthetic insulation to improve the performance of the solar collector.

Keywords: clay, insulation material, polystyrene, solar collector, straw

Procedia PDF Downloads 444
113 Predicting Long-Term Performance of Concrete under Sulfate Attack

Authors: Elakneswaran Yogarajah, Toyoharu Nawa, Eiji Owaki

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Cement-based materials have been using in various reinforced concrete structural components as well as in nuclear waste repositories. The sulfate attack has been an environmental issue for cement-based materials exposed to sulfate bearing groundwater or soils, and it plays an important role in the durability of concrete structures. The reaction between penetrating sulfate ions and cement hydrates can result in swelling, spalling and cracking of cement matrix in concrete. These processes induce a reduction of mechanical properties and a decrease of service life of an affected structure. It has been identified that the precipitation of secondary sulfate bearing phases such as ettringite, gypsum, and thaumasite can cause the damage. Furthermore, crystallization of soluble salts such as sodium sulfate crystals induces degradation due to formation and phase changes. Crystallization of mirabilite (Na₂SO₄:10H₂O) and thenardite (Na₂SO₄) or their phase changes (mirabilite to thenardite or vice versa) due to temperature or sodium sulfate concentration do not involve any chemical interaction with cement hydrates. Over the past couple of decades, an intensive work has been carried out on sulfate attack in cement-based materials. However, there are several uncertainties still exist regarding the mechanism for the damage of concrete in sulfate environments. In this study, modelling work has been conducted to investigate the chemical degradation of cementitious materials in various sulfate environments. Both internal and external sulfate attack are considered for the simulation. In the internal sulfate attack, hydrate assemblage and pore solution chemistry of co-hydrating Portland cement (PC) and slag mixing with sodium sulfate solution are calculated to determine the degradation of the PC and slag-blended cementitious materials. Pitzer interactions coefficients were used to calculate the activity coefficients of solution chemistry at high ionic strength. The deterioration mechanism of co-hydrating cementitious materials with 25% of Na₂SO₄ by weight is the formation of mirabilite crystals and ettringite. Their formation strongly depends on sodium sulfate concentration and temperature. For the external sulfate attack, the deterioration of various types of cementitious materials under external sulfate ingress is simulated through reactive transport model. The reactive transport model is verified with experimental data in terms of phase assemblage of various cementitious materials with spatial distribution for different sulfate solution. Finally, the reactive transport model is used to predict the long-term performance of cementitious materials exposed to 10% of Na₂SO₄ for 1000 years. The dissolution of cement hydrates and secondary formation of sulfate-bearing products mainly ettringite are the dominant degradation mechanisms, but not the sodium sulfate crystallization.

Keywords: thermodynamic calculations, reactive transport, radioactive waste disposal, PHREEQC

Procedia PDF Downloads 145
112 Simulation Research of Innovative Ignition System of ASz62IR Radial Aircraft Engine

Authors: Miroslaw Wendeker, Piotr Kacejko, Mariusz Duk, Pawel Karpinski

Abstract:

The research in the field of aircraft internal combustion engines is currently driven by the needs of decreasing fuel consumption and CO2 emissions, while fulfilling the level of safety. Currently, reciprocating aircraft engines are found in sports, emergency, agricultural and recreation aviation. Technically, they are most at a pre-war knowledge of the theory of operation, design and manufacturing technology, especially if compared to that high level of development of automotive engines. Typically, these engines are driven by carburetors of a quite primitive construction. At present, due to environmental requirements and dealing with a climate change, it is beneficial to develop aircraft piston engines and adopt the achievements of automotive engineering such as computer-controlled low-pressure injection, electronic ignition control and biofuels. The paper describes simulation research of the innovative power and control systems for the aircraft radial engine of high power. Installing an electronic ignition system in the radial aircraft engine is a fundamental innovative idea of this solution. Consequently, the required level of safety and better functionality as compared to the today’s plug system can be guaranteed. In this framework, this research work focuses on describing a methodology for optimizing the electronically controlled ignition system. This attempt can reduce emissions of toxic compounds as a result of lowered fuel consumption, optimized combustion and engine capability of efficient combustion of ecological fuels. New, redundant elements of the control system can improve the safety of aircraft. Consequently, the required level of safety and better functionality as compared to the today’s plug system can be guaranteed. The simulation research aimed to determine the vulnerability of the values measured (they were planned as the quantities measured by the measurement systems) to determining the optimal ignition angle (the angle of maximum torque at a given operating point). The described results covered: a) research in steady states; b) velocity ranging from 1500 to 2200 rpm (every 100 rpm); c) loading ranging from propeller power to maximum power; d) altitude ranging according to the International Standard Atmosphere from 0 to 8000 m (every 1000 m); e) fuel: automotive gasoline ES95. The three models of different types of ignition coil (different energy discharge) were studied. The analysis aimed at the optimization of the design of the innovative ignition system for an aircraft engine. The optimization involved: a) the optimization of the measurement systems; b) the optimization of actuator systems. The studies enabled the research on the vulnerability of the signals to the control of the ignition timing. Accordingly, the number and type of sensors were determined for the ignition system to achieve its optimal performance. The results confirmed the limited benefits, in terms of fuel consumption. Thus, including spark management in the optimization is mandatory to significantly decrease the fuel consumption. This work has been financed by the Polish National Centre for Research and Development, INNOLOT, under Grant Agreement No. INNOLOT/I/1/NCBR/2013.

Keywords: piston engine, radial engine, ignition system, CFD model, engine optimization

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111 The Gaps of Environmental Criminal Liability in Armed Conflicts and Its Consequences: An Analysis under Stockholm, Geneva and Rome

Authors: Vivian Caroline Koerbel Dombrowski

Abstract:

Armed conflicts have always meant the ultimate expression of power and at the same time, lack of understanding among nations. Cities were destroyed, people were killed, assets were devastated. But these are not only the loss of a war: the environmental damage comes to be considered immeasurable losses in the short, medium and long term. And this is because no nation wants to bear that cost. They invest in military equipment, training, technical equipment but the environmental account yet finds gaps in international law. Considering such a generalization in rights protection, many nations are at imminent danger in a conflict if the water will be used as a mass weapon, especially if we consider important rivers such as Jordan, Euphrates and Nile. The top three international documents were analyzed on the subject: the Stockholm Convention (1972), Additional Protocol I to the Geneva Convention (1977) and the Rome Statute (1998). Indeed, some references are researched in doctrine, especially scientific articles, to substantiate with consistent data about the extent of the damage, historical factors and decisions which have been successful. However, due to the lack of literature about this subject, the research tends to be exhaustive. From the study of the indicated material, it was noted that international law - humanitarian and environmental - calls in some of its instruments the environmental protection in war conflicts, but they are generic and vague rules that do not define exactly what is the environmental damage , nor sets standards for measure them. Taking into account the mains conflicts of the century XX: World War II, the Vietnam War and the Gulf War, one must realize that the environmental consequences were of great rides - never deactivated landmines, buried nuclear weapons, armaments and munitions destroyed in the soil, chemical weapons, not to mention the effects of some weapons when used (uranium, agent Orange, etc). Extending the search for more recent conflicts such as Afghanistan, it is proven that the effects on health of the civilian population were catastrophic: cancer, birth defects, and deformities in newborns. There are few reports of nations that, somehow, repaired the damage caused to the environment as a result of the conflict. In the pitch of contemporary conflicts, many nations fear that water resources are used as weapons of mass destruction, because once contaminated - directly or indirectly - can become a means of disguised genocide side effect of military objective. In conclusion, it appears that the main international treaties governing the subject mention the concern for environmental protection, however leave the normative specifications vacancies necessary to effectively there is a prevention of environmental damage in armed conflict and, should they occur, the repair of the same. Still, it appears that there is no protection mechanism to safeguard natural resources and avoid them to become a mass destruction weapon.

Keywords: armed conflicts, criminal liability, environmental damages, humanitarian law, mass weapon

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110 The Mitigation of Quercetin on Lead-Induced Neuroinflammation in a Rat Model: Changes in Neuroinflammatory Markers and Memory

Authors: Iliyasu Musa Omoyine, Musa Sunday Abraham, Oladele Sunday Blessing, Iliya Ibrahim Abdullahi, Ibegbu Augustine Oseloka, Nuhu Nana-Hawau, Animoku Abdulrazaq Amoto, Yusuf Abdullateef Onoruoiza, Sambo Sohnap James, Akpulu Steven Peter, Ajayi Abayomi

Abstract:

The neuroprotective role of inflammation from detrimental intrinsic and extrinsic factors has been reported. However, the overactivation of astrocytes and microglia due to lead toxicity produce excessive pro-inflammatory cytokines, mediating neurodegenerative diseases. The present study investigated the mitigatory effects of quercetin on neuroinflammation, correlating with memory function in lead-exposed rats. In this study, Wistar rats were administered orally with Quercetin (Q: 60 mg/kg) and Succimer as a standard drug (S: 10 mg/kg) for 21 days after lead exposure (Pb: 125 mg/kg) of 21 days or in combination with Pb, once daily for 42 days. Working and reference memory was assessed using an Eight-arm radial water maze (8-ARWM). The changes in brain lead level, the neuronal nitric oxide synthase (nNOS) activity, and the level of neuroinflammatory markers such as tumour necrosis factor-alpha (TNF-α) and Interleukin 1 Beta (IL-1β) were determined. Immunohistochemically, astrocyte expression was evaluated. The results showed that the brain level of lead was increased significantly in lead-exposed rats. The expression of astrocytes increased in the CA3 and CA1 regions of the hippocampus, and the levels of brain TNF-α and IL-1β increased in lead-exposed rats. Lead impaired reference and working memory by increasing reference memory errors and working memory incorrect errors in lead-exposed rats. However, quercetin treatment effectively improved memory and inhibited neuroinflammation by reducing astrocytes’ expression and the levels of TNF-α and IL-1β. The expression of astrocytes and the levels of TNF-α and IL-1β correlated with memory function. The possible explanation for quercetin’s anti-neuroinflammatory effect is that it modulates the activity of cellular proteins involved in the inflammatory response; inhibits the transcription factor of nuclear factor-kappa B (NF-κB), which regulates the expression of proinflammatory molecules; inhibits kinases required for the synthesis of Glial fibrillary acidic protein (GFAP) and modifies the phosphorylation of some proteins, which affect the structure and function of intermediate filament proteins; and, lastly, induces Cyclic-AMP Response Element Binding (CREB) activation and neurogenesis as a compensatory mechanism for memory deficits and neuronal cell death. In conclusion, the levels of neuroinflammatory markers negatively correlated with memory function. Thus, quercetin may be a promising therapy in neuroinflammation and memory dysfunction in populations prone to lead exposure.

Keywords: lead, quercetin, neuroinflammation, memory

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109 Epigastric Pain in Emergency Room: Median Arcuate Ligament Syndrome

Authors: Demet Devrimsel Dogan, Ecem Deniz Kirkpantur, Muharrem Dogan, Ahmet Aykut, Ebru Unal Akoglu, Ozge Ecmel Onur

Abstract:

Introduction: Median Arcuate Ligament Syndrome (MALS) is a rare cause of chronic abdominal pain due to external compression of the celiac trunk by a fibrous arch that unites diaphragmatic crura on each side of the aortic hiatus. While 10-24% of the population may suffer from compression of celiac trunk, it rarely causes patients to develop symptoms. The typical clinical triad of symptoms includes postprandial epigastric pain, weight loss and vomiting. The diagnosis can be made using thin section multi-detector computed tomography (CT) scans which delineate the ligament and the compressed vessel. The treatment of MALS is aimed at relieving the compression of the celiac artery to restore adequate blood flow through the vessel and neurolysis to address chronic pain. Case: A 68-year-old male presented to our clinic with acute postprandial epigastric pain. This was patients’ first attack, and the pain was the worst pain of his life. The patient did not have any other symptoms like nausea, vomiting, chest pain or dyspnea. In his medical history, the patient has had an ischemic cerebrovascular stroke 5 years ago which he recovered with no sequel, and he was using 75 mg clopidogrel and 100 mg acetylsalicylic acid. He was not using any other medication and did not have a story of cardiovascular disease. His vital signs were stable (BP:113/72 mmHg, Spo2:97, temperature:36.3°C, HR:90/bpm). In his electrocardiogram, there was ST depression in leads II, III and AVF. In his physical examination, there was only epigastric tenderness, other system examinations were normal. Physical examination through his upper gastrointestinal system showed no bleeding. His laboratory results were as follows: creatinine:1.26 mg/dL, AST:42 U/L, ALT:17 U/L, amylase:78 U/L, lipase:26 U/L, troponin:10.3 pg/ml, WBC:28.9 K/uL, Hgb:12.7 gr/dL, Plt:335 K/uL. His serial high-sensitive troponin levels were also within normal limits, his echocardiography showed no segmental wall motion abnormalities, an acute myocardial infarction was excluded. In his abdominal ultrasound, no pathology was founded. Contrast-enhanced abdominal CT and CT angiography reported ‘thickened diaphragmatic cruras are compressing and stenosing truncus celiacus superior, this is likely compatible with MALS’. The patient was consulted to general surgery, and they admitted the patient for laparoscopic ligament release. Results: MALS is a syndrome that causes postprandial pain, nausea and vomiting as its most common symptoms. Affected patients are normally young, slim women between the ages of 30 and 50 who have undergone extensive examinations to find the source of their symptoms. To diagnose MALS, other underlying pathologies should initially be excluded. The gold standard is aortic angiography. Although diagnosis and treatment of MALS are unclear, symptom resolution has been achieved with multiple surgical modalities, including open, laparoscopic or robotic ligament release as well as celiac ganglionectomy, which often requires celiac artery revascularisation.

Keywords: differential diagnosis, epigastric pain, median arcuate ligament syndrome, celiac trunk

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108 Influence of Structured Capillary-Porous Coatings on Cryogenic Quenching Efficiency

Authors: Irina P. Starodubtseva, Aleksandr N. Pavlenko

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Quenching is a term generally accepted for the process of rapid cooling of a solid that is overheated above the thermodynamic limit of the liquid superheat. The main objective of many previous studies on quenching is to find a way to reduce the total time of the transient process. Computational experiments were performed to simulate quenching by a falling liquid nitrogen film of an extremely overheated vertical copper plate with a structured capillary-porous coating. The coating was produced by directed plasma spraying. Due to the complexities in physical pattern of quenching from chaotic processes to phase transition, the mechanism of heat transfer during quenching is still not sufficiently understood. To our best knowledge, no information exists on when and how the first stable liquid-solid contact occurs and how the local contact area begins to expand. Here we have more models and hypotheses than authentically established facts. The peculiarities of the quench front dynamics and heat transfer in the transient process are studied. The created numerical model determines the quench front velocity and the temperature fields in the heater, varying in space and time. The dynamic pattern of the running quench front obtained numerically satisfactorily correlates with the pattern observed in experiments. Capillary-porous coatings with straight and reverse orientation of crests are investigated. The results show that the cooling rate is influenced by thermal properties of the coating as well as the structure and geometry of the protrusions. The presence of capillary-porous coating significantly affects the dynamics of quenching and reduces the total quenching time more than threefold. This effect is due to the fact that the initialization of a quench front on a plate with a capillary-porous coating occurs at a temperature significantly higher than the thermodynamic limit of the liquid superheat, when a stable solid-liquid contact is thermodynamically impossible. Waves present on the liquid-vapor interface and protrusions on the complex micro-structured surface cause destabilization of the vapor film and the appearance of local liquid-solid micro-contacts even though the average integral surface temperature is much higher than the liquid superheat limit. The reliability of the results is confirmed by direct comparison with experimental data on the quench front velocity, the quench front geometry, and the surface temperature change over time. Knowledge of the quench front velocity and total time of transition process is required for solving practically important problems of nuclear reactors safety.

Keywords: capillary-porous coating, heat transfer, Leidenfrost phenomenon, numerical simulation, quenching

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107 Improving Recovery Reuse and Irrigation Scheme Efficiency – North Gaza Emergency Sewage Treatment Project as Case Study

Authors: Yaser S. Kishawi, Sadi R. Ali

Abstract:

Part of Palestine, Gaza Strip (365 km2 and 1.8 million inhabitants) is considered a semi-arid zone relies solely on the Coastal Aquifer. The coastal aquifer is only source of water with only 5-10% suitable for human use. This barely cover the domestic and agricultural needs of Gaza Strip. Palestinian Water Authority Strategy is finding non-conventional water resource from treated wastewater to cover agricultural requirements and serve the population. A new WWTP project is to replace the old-overloaded Biet Lahia WWTP. The project consists of three parts; phase A (pressure line & infiltration basins - IBs), phase B (a new WWTP) and phase C (Recovery and Reuse Scheme – RRS – to capture the spreading plume). Currently, only phase A is functioning. Nearly 23 Mm3 of partially treated wastewater were infiltrated into the aquifer. Phase B and phase C witnessed many delays and this forced a reassessment of the RRS original design. An Environmental Management Plan was conducted from Jul 2013 to Jun 2014 on 13 existing monitoring wells surrounding the project location. This is to measure the efficiency of the SAT system and the spread of the contamination plume with relation to the efficiency of the proposed RRS. Along with the proposed location of the 27 recovery wells as part of the proposed RRS. The results of monitored wells were assessed compared with PWA baseline data. This was put into a groundwater model to simulate the plume to propose the best suitable solution to the delays. The redesign mainly manipulated the pumping rate of wells, proposed locations and functioning schedules (including wells groupings). The proposed simulations were examined using visual MODFLOW V4.2 to simulate the results. The results of monitored wells were assessed based on the location of the monitoring wells related to the proposed recovery wells locations (200m, 500m and 750m away from the IBs). Near the 500m line (the first row of proposed recovery wells), an increase of nitrate (from 30 to 70mg/L) compare to a decrease in Chloride (1500 to below 900mg/L) was found during the monitoring period which indicated an expansion of plume to this distance. On this rate with the required time to construct the recovery scheme, keeping the original design the RRS will fail to capture the plume. Based on that many simulations were conducted leading into three main scenarios. The scenarios manipulated the starting dates, the pumping rate and the locations of recovery wells. A simulation of plume expansion and path-lines were extracted from the model monitoring how to prevent the expansion towards the nearby municipal wells. It was concluded that the location is the most important factor in determining the RRS efficiency. Scenario III was adopted and showed an effective results even with a reduced pumping rates. This scenario proposed adding two additional recovery wells in a location beyond the 750m line to compensate the delays and effectively capture the plume. A continuous monitoring program for current and future monitoring wells should be in place to support the proposed scenario and ensure maximum protection.

Keywords: soil aquifer treatment, recovery and reuse scheme, infiltration basins, north gaza

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