Search results for: sheet metal forming
Commenced in January 2007
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Edition: International
Paper Count: 3705

Search results for: sheet metal forming

285 Health Risk Assessment and Source Apportionment of Elemental Particulate Contents from a South Asian Future Megacity

Authors: Afifa Aslam, Muhammad Ibrahim, Abid Mahmood, Muhammad Usman Alvi, Fariha Jabeen, Umara Tabassum

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Many factors cause air pollution in Pakistan, which poses a significant threat to human health. Diesel fuel and gasoline motor vehicles, as well as industrial companies, pollute the air in Pakistan's cities. The study's goal is to determine the level of air pollution in a Pakistani industrial city and to establish risk levels for the health of the population. We measured the intensity of air pollution by chemical characterization and examination of air samples collected at stationary remark sites. The PM10 levels observed at all sampling sites, including residential, commercial, high-traffic, and industrial areas were well above the limits imposed by Pakistan EPA, the United States EPA, and WHO. We assessed the health risk via chemical factors using a methodology approved for risk assessment. All Igeo index values greater than one were considered moderately contaminated or moderately to severely contaminated. Heavy metals have a substantial risk of acute adverse effects. In Faisalabad, Pakistan, there was an enormously high risk of chronic effects produced by a heavy metal acquaintance. Concerning specified toxic metals, intolerable levels of carcinogenic risks have been determined for the entire population. As a result, in most of the investigated areas of Faisalabad, the indices and hazard quotients for chronic and acute exposure exceeded the permissible level of 1.0. In the current study, re-suspended roadside mineral dust, anthropogenic exhaust emissions from traffic and industry, and industrial dust were identified as major emission sources of elemental particulate contents. Because of the unacceptable levels of risk in the research area, it is strongly suggested that a comprehensive study of the population's health status as a result of air pollution should be conducted for policies to be developed against these risks.

Keywords: elemental composition, particulate pollution, Igeo index, health risk assessment, hazard quotient

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284 A Rural Journey of Integrating Interprofessional Education to Foster Trust

Authors: Julia Wimmers Klick

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Interprofessional Education (IPE) is widely recognized as a valuable approach in healthcare education, despite the challenges it presents. This study explores IP surface anatomy lab sessions, with a focus on fostering trust and collaboration among healthcare students. The research is conducted within the context of rural healthcare settings in British Columbia (BC), where a medical school and a physical therapy (PT) program operate under the Faculty of Medicine at the University of British Columbia (UBC). While IPE sessions addressing soft skills have been implemented, the integration of hard skills, such as Anatomy, remains limited. To address this gap, a pilot feasibility study was conducted with a positive outcome, a follow-up study involved these IPE sessions aimed at exploring the influence of bonding and trust between medical and PT students. Data were collected through focus groups comprising participating students and faculty members, and a structured SWOC (Strengths, Weaknesses, Opportunities, and Challenges) analysis was conducted. The IPE sessions, 3 in total, consisted of a 2.5-hour lab on surface anatomy, where PT students took on the teaching role, and medical students were newly exposed to surface anatomy. The focus of the study was on the relationship-building process and trust development between the two student groups, rather than assessing the acquisition of surface anatomy skills. Results indicated that the surface anatomy lab served as a suitable tool for the application and learning of soft skills. Faculty members observed positive outcomes, including productive interaction between students, reversed hierarchy with PT students teaching medical students, practicing active listening skills, and using a mutual language of anatomy. Notably, there was no grade assessment or external pressure to perform. The students also reported an overall positive experience; however, the specific impact on the development of soft skill competencies could not be definitively determined. Participants expressed a sense of feeling respected, welcomed, and included, all of which contributed to feeling safe. Within the small group environment, students experienced becoming a part of a community of healthcare providers that bonded over a shared interest in health professions education. They enjoyed sharing diverse experiences related to learning across their varied contexts, without fear of judgment and reprisal that were often intimidating in single professional contexts. During a joint Christmas party for both cohorts, faculty members observed students mingling, laughing, and forming bonds. This emphasized the importance of early bonding and trust development among healthcare colleagues, particularly in rural settings. In conclusion, the findings emphasize the potential of IPE sessions to enhance trust and collaboration among healthcare students, with implications for their future professional lives in rural settings. Early bonding and trust development are crucial in rural settings, where healthcare professionals often rely on each other. Future research should continue to explore the impact of content-concentrated IPE on the development of soft skill competencies.

Keywords: interprofessional education, rural healthcare settings, trust, surface anatomy

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283 Treatment Process of Sludge from Leachate with an Activated Sludge System and Extended Aeration System

Authors: A. Chávez, A. Rodríguez, F. Pinzón

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Society is concerned about measures of environmental, economic and social impacts generated in the solid waste disposal. These places of confinement, also known as landfills, are locations where problems of pollution and damage to human health are reduced. They are technically designed and operated, using engineering principles, storing the residue in a small area, compact it to reduce volume and covering them with soil layers. Problems preventing liquid (leachate) and gases produced by the decomposition of organic matter. Despite planning and site selection for disposal, monitoring and control of selected processes, remains the dilemma of the leachate as extreme concentration of pollutants, devastating soil, flora and fauna; aggressive processes requiring priority attention. A biological technology is the activated sludge system, used for tributaries with high pollutant loads. Since transforms biodegradable dissolved and particulate matter into CO2, H2O and sludge; transform suspended and no Settleable solids; change nutrients as nitrogen and phosphorous; and degrades heavy metals. The microorganisms that remove organic matter in the processes are in generally facultative heterotrophic bacteria, forming heterogeneous populations. Is possible to find unicellular fungi, algae, protozoa and rotifers, that process the organic carbon source and oxygen, as well as the nitrogen and phosphorus because are vital for cell synthesis. The mixture of the substrate, in this case sludge leachate, molasses and wastewater is maintained ventilated by mechanical aeration diffusers. Considering as the biological processes work to remove dissolved material (< 45 microns), generating biomass, easily obtained by decantation processes. The design consists of an artificial support and aeration pumps, favoring develop microorganisms (denitrifying) using oxygen (O) with nitrate, resulting in nitrogen (N) in the gas phase. Thus, avoiding negative effects of the presence of ammonia or phosphorus. Overall the activated sludge system includes about 8 hours of hydraulic retention time, which does not prevent the demand for nitrification, which occurs on average in a value of MLSS 3,000 mg/L. The extended aeration works with times greater than 24 hours detention; with ratio of organic load/biomass inventory under 0.1; and average stay time (sludge age) more than 8 days. This project developed a pilot system with sludge leachate from Doña Juana landfill - RSDJ –, located in Bogota, Colombia, where they will be subjected to a process of activated sludge and extended aeration through a sequential Bach reactor - SBR, to be dump in hydric sources, avoiding ecological collapse. The system worked with a dwell time of 8 days, 30 L capacity, mainly by removing values of BOD and COD above 90%, with initial data of 1720 mg/L and 6500 mg/L respectively. Motivating the deliberate nitrification is expected to be possible commercial use diffused aeration systems for sludge leachate from landfills.

Keywords: sludge, landfill, leachate, SBR

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282 Elevated Reductive Defluorination of Branched Per and Polyfluoroalkyl Substances by Soluble Metal-Porphyrins and New Mechanistic Insights on the Degradation

Authors: Jun Sun, Tsz Tin Yu, Maryam Mirabediny, Matthew Lee, Adele Jones, Denis M. O’Carroll, Michael J. Manefield, Björn Åkermark, Biswanath Das, Naresh Kumar

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Reductive defluorination has emerged as a sustainable approach to clean water from Per and polyfluoroalkyl substances (PFASs), also known as forever organic containments. For last few decades, nano zero valent metals (nZVMs) have been intensively applied in the reductive remediation of groundwater contaminated with chlorinated organic compounds due to its low redox potential, easy application, and low production cost. However, there is inadequate information on the effective reductive defluorination of linear or branched PFAS using nZVMs as reductants because of the lack of suitable catalysts. CoII-5,10,15,20-Tetraphenyl-21H,23H-porphyrin (CoTPP) has been recently reported for effective catalyzing reductive defluorination of branched (br-) perfluorooctane sulfonate (PFOS) by using TiIII citrate as reductant. However, the low water solubility of CoTPP limited its applicability. Here, we explored a series of structurally related soluble cobalt porphyrin catalysts based on our previously reported best performing CoTPP. All soluble porphyrins [[meso-tetra(4-carboxyphenyl)porphyrinato]cobalt(III)]Cl·₇H₂O (CoTCPP), [[meso-tetra(4-sulfonatophenyl) porphyrinato]cobalt(III)]·9H2O (CoTPPS), and [[meso-tetra(4-N-methylpyridyl) porphyrinato]cobalt(II)](I)₄·₄H₂O (CoTMpyP) displayed better defluorination efficiencies than CoTPP. Especially, CoTMpyP presented the best defluorination efficiency for br-PFOS (94 %), branched perfluorooctanoic acid (PFOA) (89 %), and 3,7-Perfluorodecanoic acid (PFDA) (60 %) after 1 day at 70 0C. CoTMpyP-nZn0 system showed 88-164 times higher defluorination rate than VB12-nZn0 system in terms of all investigated br-PFASs. The CoTMpyP-nZn0 also performed effectively at room temperature, demonstrating the potential prospect for in-situ reductive systems. Based on the analysis of the intermediate products, the calculated bond dissociation energies (BDEs) and possible first interaction between CoTMpyP and PFAS, degradation pathways of 3,7-PFDA and 6-PFOS are proposed.

Keywords: cationic, soluble porphyrin, cobalt, vitamin b12, pfas, reductive defluorination

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281 Piezotronic Effect on Electrical Characteristics of Zinc Oxide Varistors

Authors: Nadine Raidl, Benjamin Kaufmann, Michael Hofstätter, Peter Supancic

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If polycrystalline ZnO is properly doped and sintered under very specific conditions, it shows unique electrical properties, which are indispensable for today’s electronic industries, where it is used as the number one overvoltage protection material. Under a critical voltage, the polycrystalline bulk exhibits high electrical resistance but becomes suddenly up to twelve magnitudes more conductive if this voltage limit is exceeded (i.e., varistor effect). It is known that these peerless properties have their origin in the grain boundaries of the material. Electric charge is accumulated in the boundaries, causing a depletion layer in their vicinity and forming potential barriers (so-called Double Schottky Barriers, or DSB) which are responsible for the highly non-linear conductivity. Since ZnO is a piezoelectric material, mechanical stresses induce polarisation charges that modify the DSB heights and as a result the global electrical characteristics (i.e., piezotronic effect). In this work, a finite element method was used to simulate emerging stresses on individual grains in the bulk. Besides, experimental efforts were made to testify a coherent model that could explain this influence. Electron back scattering diffraction was used to identify grain orientations. With the help of wet chemical etching, grain polarization was determined. Micro lock-in infrared thermography (MLIRT) was applied to detect current paths through the material, and a micro 4-point probes method system (M4PPS) was employed to investigate current-voltage characteristics between single grains. Bulk samples were tested under uniaxial pressure. It was found that the conductivity can increase by up to three orders of magnitude with increasing stress. Through in-situ MLIRT, it could be shown that this effect is caused by the activation of additional current paths in the material. Further, compressive tests were performed on miniaturized samples with grain paths containing solely one or two grain boundaries. The tests evinced both an increase of the conductivity, as observed for the bulk, as well as a decreased conductivity. This phenomenon has been predicted theoretically and can be explained by piezotronically induced surface charges that have an impact on the DSB at the grain boundaries. Depending on grain orientation and stress direction, DSB can be raised or lowered. Also, the experiments revealed that the conductivity within one single specimen can increase and decrease, depending on the current direction. This novel finding indicates the existence of asymmetric Double Schottky Barriers, which was furthermore proved by complementary methods. MLIRT studies showed that the intensity of heat generation within individual current paths is dependent on the direction of the stimulating current. M4PPS was used to study the relationship between the I-V characteristics of single grain boundaries and grain orientation and revealed asymmetric behavior for very specific orientation configurations. A new model for the Double Schottky Barrier, taking into account the natural asymmetry and explaining the experimental results, will be given.

Keywords: Asymmetric Double Schottky Barrier, piezotronic, varistor, zinc oxide

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280 NanoFrazor Lithography for advanced 2D and 3D Nanodevices

Authors: Zhengming Wu

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NanoFrazor lithography systems were developed as a first true alternative or extension to standard mask-less nanolithography methods like electron beam lithography (EBL). In contrast to EBL they are based on thermal scanning probe lithography (t-SPL). Here a heatable ultra-sharp probe tip with an apex of a few nm is used for patterning and simultaneously inspecting complex nanostructures. The heat impact from the probe on a thermal responsive resist generates those high-resolution nanostructures. The patterning depth of each individual pixel can be controlled with better than 1 nm precision using an integrated in-situ metrology method. Furthermore, the inherent imaging capability of the Nanofrazor technology allows for markerless overlay, which has been achieved with sub-5 nm accuracy as well as it supports stitching layout sections together with < 10 nm error. Pattern transfer from such resist features below 10 nm resolution were demonstrated. The technology has proven its value as an enabler of new kinds of ultra-high resolution nanodevices as well as for improving the performance of existing device concepts. The application range for this new nanolithography technique is very broad spanning from ultra-high resolution 2D and 3D patterning to chemical and physical modification of matter at the nanoscale. Nanometer-precise markerless overlay and non-invasiveness to sensitive materials are among the key strengths of the technology. However, while patterning at below 10 nm resolution is achieved, significantly increasing the patterning speed at the expense of resolution is not feasible by using the heated tip alone. Towards this end, an integrated laser write head for direct laser sublimation (DLS) of the thermal resist has been introduced for significantly faster patterning of micrometer to millimeter-scale features. Remarkably, the areas patterned by the tip and the laser are seamlessly stitched together and both processes work on the very same resist material enabling a true mix-and-match process with no developing or any other processing steps in between. The presentation will include examples for (i) high-quality metal contacting of 2D materials, (ii) tuning photonic molecules, (iii) generating nanofluidic devices and (iv) generating spintronic circuits. Some of these applications have been enabled only due to the various unique capabilities of NanoFrazor lithography like the absence of damage from a charged particle beam.

Keywords: nanofabrication, grayscale lithography, 2D materials device, nano-optics, photonics, spintronic circuits

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279 Toxic Metal and Radiological Risk Assessment of Soil, Water and Vegetables around a Gold Mine Turned Residential Area in Mokuro Area of Ile-Ife, Osun State Nigeria: An Implications for Human Health

Authors: Grace O. Akinlade, Danjuma D. Maza, Oluwakemi O. Olawolu, Delight O. Babalola, John A. O. Oyekunle, Joshua O. Ojo

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The Mokuro area of Ile-Ife, South West Nigeria, was well known for gold mining in the past (about twenty years ago). However, the place has since been reclaimed and converted to residential area without any environmental risk assessment of the impact of the mining tailings on the environment. Soil, water, and plant samples were collected from 4 different locations around the mine-turned-residential area. Soil samples were pulverized and sieved into finer particles, while the plant samples were dried and pulverized. All the samples were digested and analyzed for As, Pb, Cd, and Zn using atomic absorption spectroscopy (AAS). From the analysis results, the hazard index (HI) was then calculated for the metals. The soil and plant samples were air dried and pulverized, then weighed, after which the samples were packed into special and properly sealed containers to prevent radon gas leakage. After the sealing, the samples were kept for 28 days to attain secular equilibrium. The concentrations of 40K, 238U, and 232Th in the samples were measured using a cesium iodide (CsI) spectrometer and URSA software. The AAS analysis showed that As, Pb, Cd (Toxic metals), and Zn (essential trace metals) are in concentrations lower than permissible limits in plants and soil samples, while the water samples had concentrations higher than permissible limits. The calculated health indices (HI) show that HI for water is >1 and that of plants and soil is <1. Gamma spectrometry result shows high levels of activity concentrations above the recommended limits for all the soil and plant samples collected from the area. Only the water samples have activity concentrations below the recommended limit. Consequently, the absorbed dose, annual effective dose, and excess lifetime cancer risk are all above the recommended safe limit for all the samples except for water samples. In conclusion, all the samples collected from the area are either contaminated with toxic metals or they pose radiological hazards to the consumers. Further detailed study is therefore recommended in order to be able to advise the residents appropriately.

Keywords: toxic metals, gamma spectrometry, Ile-Ife, radiological hazards, gold mining

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278 Smart Sensor Data to Predict Machine Performance with IoT-Based Machine Learning and Artificial Intelligence

Authors: C. J. Rossouw, T. I. van Niekerk

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The global manufacturing industry is utilizing the internet and cloud-based services to further explore the anatomy and optimize manufacturing processes in support of the movement into the Fourth Industrial Revolution (4IR). The 4IR from a third world and African perspective is hindered by the fact that many manufacturing systems that were developed in the third industrial revolution are not inherently equipped to utilize the internet and services of the 4IR, hindering the progression of third world manufacturing industries into the 4IR. This research focuses on the development of a non-invasive and cost-effective cyber-physical IoT system that will exploit a machine’s vibration to expose semantic characteristics in the manufacturing process and utilize these results through a real-time cloud-based machine condition monitoring system with the intention to optimize the system. A microcontroller-based IoT sensor was designed to acquire a machine’s mechanical vibration data, process it in real-time, and transmit it to a cloud-based platform via Wi-Fi and the internet. Time-frequency Fourier analysis was applied to the vibration data to form an image representation of the machine’s behaviour. This data was used to train a Convolutional Neural Network (CNN) to learn semantic characteristics in the machine’s behaviour and relate them to a state of operation. The same data was also used to train a Convolutional Autoencoder (CAE) to detect anomalies in the data. Real-time edge-based artificial intelligence was achieved by deploying the CNN and CAE on the sensor to analyse the vibration. A cloud platform was deployed to visualize the vibration data and the results of the CNN and CAE in real-time. The cyber-physical IoT system was deployed on a semi-automated metal granulation machine with a set of trained machine learning models. Using a single sensor, the system was able to accurately visualize three states of the machine’s operation in real-time. The system was also able to detect a variance in the material being granulated. The research demonstrates how non-IoT manufacturing systems can be equipped with edge-based artificial intelligence to establish a remote machine condition monitoring system.

Keywords: IoT, cyber-physical systems, artificial intelligence, manufacturing, vibration analytics, continuous machine condition monitoring

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277 Modelling for Roof Failure Analysis in an Underground Cave

Authors: M. Belén Prendes-Gero, Celestino González-Nicieza, M. Inmaculada Alvarez-Fernández

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Roof collapse is one of the problems with a higher frequency in most of the mines of all countries, even now. There are many reasons that may cause the roof to collapse, namely the mine stress activities in the mining process, the lack of vigilance and carelessness or the complexity of the geological structure and irregular operations. This work is the result of the analysis of one accident produced in the “Mary” coal exploitation located in northern Spain. In this accident, the roof of a crossroad of excavated galleries to exploit the “Morena” Layer, 700 m deep, collapsed. In the paper, the work done by the forensic team to determine the causes of the incident, its conclusions and recommendations are collected. Initially, the available documentation (geology, geotechnics, mining, etc.) and accident area were reviewed. After that, laboratory and on-site tests were carried out to characterize the behaviour of the rock materials and the support used (metal frames and shotcrete). With this information, different hypotheses of failure were simulated to find the one that best fits reality. For this work, the software of finite differences in three dimensions, FLAC 3D, was employed. The results of the study confirmed that the detachment was originated as a consequence of one sliding in the layer wall, due to the large roof span present in the place of the accident, and probably triggered as a consequence of the existence of a protection pillar insufficient. The results allowed to establish some corrective measures avoiding future risks. For example, the dimensions of the protection zones that must be remained unexploited and their interaction with the crossing areas between galleries, or the use of more adequate supports for these conditions, in which the significant deformations may discourage the use of rigid supports such as shotcrete. At last, a grid of seismic control was proposed as a predictive system. Its efficiency was tested along the investigation period employing three control equipment that detected new incidents (although smaller) in other similar areas of the mine. These new incidents show that the use of explosives produces vibrations which are a new risk factor to analyse in a next future.

Keywords: forensic analysis, hypothesis modelling, roof failure, seismic monitoring

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276 Seismic Active Earth Pressure on Retaining Walls with Reinforced Backfill

Authors: Jagdish Prasad Sahoo

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The increase in active earth pressure during the event of an earthquake results sliding, overturning and tilting of earth retaining structures. In order to improve upon the stability of structures, the soil mass is often reinforced with various types of reinforcements such as metal strips, geotextiles, and geogrids etc. The stresses generated in the soil mass are transferred to the reinforcements through the interface friction between the earth and the reinforcement, which in turn reduces the lateral earth pressure on the retaining walls. Hence, the evaluation of earth pressure in the presence of seismic forces with an inclusion of reinforcements is important for the design retaining walls in the seismically active zones. In the present analysis, the effect of reinforcing horizontal layers of reinforcements in the form of sheets (Geotextiles and Geogrids) in sand used as backfill, on reducing the active earth pressure due to earthquake body forces has been studied. For carrying out the analysis, pseudo-static approach has been adopted by employing upper bound theorem of limit analysis in combination with finite elements and linear optimization. The computations have been performed with and out reinforcements for different internal friction angle of sand varying from 30 ° to 45 °. The effectiveness of the reinforcement in reducing the active earth pressure on the retaining walls is examined in terms of active earth pressure coefficient for presenting the solutions in a non-dimensional form. The active earth pressure coefficient is expressed as functions of internal friction angle of sand, interface friction angle between sand and reinforcement, soil-wall interface roughness conditions, and coefficient of horizontal seismic acceleration. It has been found that (i) there always exists a certain optimum depth of the reinforcement layers corresponding to which the value of active earth pressure coefficient becomes always the minimum, and (ii) the active earth pressure coefficient decreases significantly with an increase in length of reinforcements only up to a certain length beyond which a further increase in length hardly causes any reduction in the values active earth pressure. The optimum depth of the reinforcement layers and the required length of reinforcements corresponding to the optimum depth of reinforcements have been established. The numerical results developed in this analysis are expected to be useful for purpose of design of retaining walls.

Keywords: active, finite elements, limit analysis, presudo-static, reinforcement

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275 Photoluminescent Properties of Noble Metal Nanoparticles Supported Yttrium Aluminum Garnet Nanoparticles Doped with Cerium (Ⅲ) Ions

Authors: Mitsunobu Iwasaki, Akifumi Iseda

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Yttrium aluminum garnet doped with cerium (Ⅲ) ions (Y3Al5O12:Ce3+, YAG:Ce3+) has attracted a great attention because it can efficiently convert the blue light into a very broad yellow emission band, which produces white light emitting diodes and is applied for panel displays. To improve the brightness and resolution of the display, a considerable attention has been directed to develop fine phosphor particles. We have prepared YAG:Ce3+ nanophosphors by environmental-friendly wet process. The peak maximum of absorption spectra of surface plasmon of Ag nanopaticles are close to that of the excitation spectra (460 nm) of YAG:Ce3+. It can be expected that Ag nanoparticles supported onto the surface of YAG:Ce3+ (Ag-YAG:Ce3+) enhance the absorption of Ce3+ ions. In this study, we have prepared Ag-YAG:Ce3+ nanophosphors and investigated their photoluminescent properties. YCl3・6H2O and AlCl3・6H2O with a molar ratio of Y:Al=3:5 were dissolved in ethanol (100 ml), and CeCl3•7H2O (0.3 mol%) was further added to the above solution. Then, NaOH (4.6×10-2 mol) dissolved in ethanol (50 ml) was added dropwise to the mixture under reflux over 2 hours, and the solution was further refluxed for 1 hour. After cooling to room temperature, precipitates in the reaction mixture were heated at 673 K for 1 hour. After the calcination, the particles were immersed in AgNO3 solution for 1 hour, followed by sintering at 1123 K for 1 hour. YAG:Ce3+ were confirmed to be nanocrystals with a crystallite size of 50-80 nm in diameter. Ag nanoparticles supported onto YAG:Ce3+ were single nanometers in diameter. The excitation and emission spectra were 454 nm and 539 nm at a maximum wavelength, respectively. The emission intensity was maximum for Ag-YAG:Ce3+ immersed into 0.5 mM AgCl (Ag-YAG:Ce (0.5 mM)). The absorption maximum (461 nm) was increased for Ag-YAG:Ce3+ in comparison with that for YAG:Ce3+, indicating that the absorption was enhanced by the addition of Ag. The external and internal quantum efficiencies became 11.2 % and 36.9 % for Ag-YAG:Ce (0.5 mM), respectively. The emission intensity and absorption maximum of Ag-YAG:Ce (0.5 mM)×n (n=1, 2, 3) were increased with an increase of the number of supporting times (n), respectively. The external and internal quantum efficiencies were increased for the increase of n, respectively. The external quantum efficiency of Ag-YAG:Ce (0.5 mM) (n=3) became twice as large as that of YAG:Ce. In conclusion, Ag nanoparticles supported onto YAG:Ce3+ increased absorption and quantum efficiency. Therefore, the support of Ag nanoparticles enhanced the photoluminescent properties of YAG:Ce3+.

Keywords: plasmon, quantum efficiency, silver nanoparticles, yttrium aluminum garnet

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274 Becoming Vegan: The Theory of Planned Behavior and the Moderating Effect of Gender

Authors: Estela Díaz

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This article aims to make three contributions. First, build on the literature on ethical decision-making literature by exploring factors that influence the intention of adopting veganism. Second, study the superiority of extended models of the Theory of Planned Behavior (TPB) for understanding the process involved in forming the intention of adopting veganism. Third, analyze the moderating effect of gender on TPB given that attitudes and behavior towards animals are gender-sensitive. No study, to our knowledge, has examined these questions. Veganism is not a diet but a political and moral stand that exclude, for moral reasons, the use of animals. Although there is a growing interest in studying veganism, it continues being overlooked in empirical research, especially within the domain of social psychology. TPB has been widely used to study a broad range of human behaviors, including moral issues. Nonetheless, TPB has rarely been applied to examine ethical decisions about animals and, even less, to veganism. Hence, the validity of TPB in predicting the intention of adopting veganism remains unanswered. A total of 476 non-vegan Spanish university students (55.6% female; the mean age was 23.26 years, SD= 6.1) responded to online and pencil-and-paper self-reported questionnaire based on previous studies. TPB extended models incorporated two background factors: ‘general attitudes towards humanlike-attributes ascribed to animals’ (AHA) (capacity for reason/emotions/suffer, moral consideration, and affect-towards-animals); and ‘general attitudes towards 11 uses of animals’ (AUA). SPSS 22 and SmartPLS 3.0 were used for statistical analyses. This study constructed a second-order reflective-formative model and took the multi-group analysis (MGA) approach to study gender effects. Six models of TPB (the standard and five competing) were tested. No a priori hypotheses were formulated. The results gave partial support to TPB. Attitudes (ATTV) (β = .207, p < .001), subjective norms (SNV) (β = .323, p < .001), and perceived control behavior (PCB) (β = .149, p < .001) had a significant direct effect on intentions (INTV). This model accounted for 27,9% of the variance in intention (R2Adj = .275) and had a small predictive relevance (Q2 = .261). However, findings from this study reveal that contrary to what TPB generally proposes, the effect of the background factors on intentions was not fully mediated by the proximal constructs of intentions. For instance, in the final model (Model#6), both factors had significant multiple indirect effect on INTV (β = .074, 95% C = .030, .126 [AHA:INTV]; β = .101, 95% C = .055, .155 [AUA:INTV]) and significant direct effect on INTV (β = .175, p < .001 [AHA:INTV]; β = .100, p = .003 [AUA:INTV]). Furthermore, the addition of direct paths from background factors to intentions improved the explained variance in intention (R2 = .324; R2Adj = .317) and the predictive relevance (Q2 = .300) over the base-model. This supports existing literature on the superiority of enhanced TPB models to predict ethical issues; which suggests that moral behavior may add additional complexity to decision-making. Regarding gender effect, MGA showed that gender only moderated the influence of AHA on ATTV (e.g., βWomen−βMen = .296, p < .001 [Model #6]). However, other observed gender differences (e.g. the explained variance of the model for intentions were always higher for men that for women, for instance, R2Women = .298; R2Men = .394 [Model #6]) deserve further considerations, especially for developing more effective communication strategies.

Keywords: veganism, Theory of Planned Behavior, background factors, gender moderation

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273 Enhanced Dielectric Properties of La Substituted CoFe2O4 Magnetic Nanoparticles

Authors: M. Vadivel, R. Ramesh Babu

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Spinel ferrite magnetic nanomaterials have received a great deal of attention in recent years due to their wide range of potential applications in various fields such as magnetic data storage and microwave device applications. Among the family of spinel ferrites, cobalt ferrite (CoFe2O4) has been widely used in the field of high-frequency applications because of its remarkable material qualities such as moderate saturation magnetization, high coercivity, large permeability at higher frequency and high electrical resistivity. For aforementioned applications, the materials should have an improved electrical property, especially enhancement in the dielectric properties. It is well known that the substitution of rare earth metal cations in Fe3+ site of CoFe2O4 nanoparticles leads to structural distortion and thus significantly influences the structural and morphological properties whereas greatly modifies the electrical and magnetic properties of a material. In the present investigation, we report on the influence of lanthanum (La3+) ion substitution on the structural, morphological, dielectric and magnetic properties of CoFe2O4 magnetic nanoparticles prepared by co-precipitation method. Powder X-ray diffraction patterns reveal the formation of inverse cubic spinel structure with the signature of LaFeO3 phase at higher La3+ ion concentrations. Raman and Fourier transform infrared spectral analysis also confirms the formation of inverse cubic spinel structure and Fe-O symmetrical stretching vibrations of CoFe2O4 nanoparticles, respectively. Transmission electron microscopy study reveals that the size of the particles gradually increases with increasing La3+ ion concentrations whereas the agglomeration gets slightly reduced for La3+ ion substituted CoFe2O4 nanoparticles than that of undoped CoFe2O4 nanoparticles. Dielectric properties such as dielectric constant and dielectric loss were recorded as a function of frequency and temperature which reveals that the dielectric constant gradually increases with increasing temperatures as well as La3+ ion concentrations. The increased dielectric constant might be the reason that the formation of LaFeO3 secondary phase at higher La3+ ion concentrations. Magnetic measurement demonstrates that the saturation magnetization gradually decreases from 61.45 to 25.13 emu/g with increasing La3+ ion concentrations which is due to the nonmagnetic nature of La3+ ions substitution.

Keywords: cobalt ferrite, co-precipitation, dielectric properties, saturation magnetization

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272 Structural Analysis of Phase Transformation and Particle Formation in Metastable Metallic Thin Films Grown by Plasma-Enhanced Atomic Layer Deposition

Authors: Pouyan Motamedi, Ken Bosnick, Ken Cadien, James Hogan

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Growth of conformal ultrathin metal films has attracted a considerable amount of attention recently. Plasma-enhanced atomic layer deposition (PEALD) is a method capable of growing conformal thin films at low temperatures, with an exemplary control over thickness. The authors have recently reported on growth of metastable epitaxial nickel thin films via PEALD, along with a comprehensive characterization of the films and a study on the relationship between the growth parameters and the film characteristics. The goal of the current study is to use the mentioned films as a case study to investigate the temperature-activated phase transformation and agglomeration in ultrathin metallic films. For this purpose, metastable hexagonal nickel thin films were annealed using a controlled heating/cooling apparatus. The transformations in the crystal structure were observed via in-situ synchrotron x-ray diffraction. The samples were annealed to various temperatures in the range of 400-1100° C. The onset and progression of particle formation were studied in-situ via laser measurements. In addition, a four-point probe measurement tool was used to record the changes in the resistivity of the films, which is affected by phase transformation, as well as roughening and agglomeration. Thin films annealed at various temperature steps were then studied via atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy, in order to get a better understanding of the correlated mechanisms, through which phase transformation and particle formation occur. The results indicate that the onset of hcp-to-bcc transformation is at 400°C, while particle formations commences at 590° C. If the annealed films are quenched after transformation, but prior to agglomeration, they show a noticeable drop in resistivity. This can be attributed to the fact that the hcp films are grown epitaxially, and are under severe tensile strain, and annealing leads to relaxation of the mismatch strain. In general, the results shed light on the nature of structural transformation in nickel thin films, as well as metallic thin films, in general.

Keywords: atomic layer deposition, metastable, nickel, phase transformation, thin film

Procedia PDF Downloads 329
271 A Study on the Chemical Composition of Kolkheti's Sphagnum Peat Peloids to Evaluate the Perspective of Use in Medical Practice

Authors: Al. Tsertsvadze. L. Ebralidze, I. Matchutadze. D. Berashvili, A. Bakuridze

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Peatlands are landscape elements, they are formed over a very long period by physical, chemical, biologic, and geologic processes. In the moderate zone of Caucasus, the Kolkheti lowlands are distinguished by the diversity of relictual plants, a high degree of endemism, orographic, climate, landscape, and other characteristics of high levels of biodiversity. The unique properties of the Kolkheti region lead to the formation of special, so-called, endemic peat peloids. The composition and properties of peloids strongly depend on peat-forming plants. Peat is considered a unique complex of raw materials, which can be used in different fields of the industry: agriculture, metallurgy, energy, biotechnology, chemical industry, health care. They are formed in permanent wetland areas. As a result of decay, higher plants remain in the anaerobic area, with the participation of microorganisms. Peat mass absorbs soil and groundwater. Peloids are predominantly rich with humic substances, which are characterized by high biological activity. Humic acids stimulate enzymatic activity, regenerative processes, and have anti-inflammatory activity. Objects of the research were Kolkheti peat peloids (Ispani, Anaklia, Churia, Chirukhi, Peranga) possessing different formation phases. Due to specific physical and chemical properties of research objects, the aim of the research was to develop analytical methods in order to study the chemical composition of the objects. The research was held using modern instrumental methods of analysis: Ultraviolet-visible spectroscopy and Infrared spectroscopy, Scanning Electron Microscopy, Centrifuge, dry oven, Ultraturax, pH meter, fluorescence spectrometer, Gas chromatography-mass spectrometry (GC-MS/MS), Gas chromatography. Based on the research ration between organic and inorganic substances, the spectrum of micro and macro elements, also the content of minerals was determined. The content of organic nitrogen was determined using the Kjeldahl method. The total composition of amino acids was studied by a spectrophotometric method using standard solutions of glutamic and aspartic acids. Fatty acid was determined using GC (Gas chromatography). Based on the obtained results, we can conclude that the method is valid to identify fatty acids in the research objects. The content of organic substances in the research objects was held using GC-MS. Using modern instrumental methods of analysis, the chemical composition of research objects was studied. Each research object is predominantly reached with a broad spectrum of organic (fatty acids, amino acids, carbocyclic and heterocyclic compounds, organic acids and their esters, steroids) and inorganic (micro and macro elements, minerals) substances. Modified methods used in the presented research may be utilized for the evaluation of cosmetological balneological and pharmaceutical means prepared on the base of Kolkheti's Sphagnum Peat Peloids.

Keywords: modern analytical methods, natural resources, peat, chemistry

Procedia PDF Downloads 127
270 Experimental investigation on the lithium-Ion Battery Thermal Management System Based on Micro Heat Pipe Array in High Temperature Environment

Authors: Ruyang Ren, Yaohua Zhao, Yanhua Diao

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The intermittent and unstable characteristics of renewable energy such as solar energy can be effectively solved through battery energy storage system. Lithium-ion battery is widely used in battery energy storage system because of its advantages of high energy density, small internal resistance, low self-discharge rate, no memory effect and long service life. However, the performance and service life of lithium-ion battery is seriously affected by its operating temperature. Thus, the safety operation of the lithium-ion battery module is inseparable from an effective thermal management system (TMS). In this study, a new type of TMS based on micro heat pipe array (MHPA) for lithium-ion battery is established, and the TMS is applied to a battery energy storage box that needs to operate at a high temperature environment of 40 °C all year round. MHPA is a flat shape metal body with high thermal conductivity and excellent temperature uniformity. The battery energy storage box is composed of four battery modules, with a nominal voltage of 51.2 V, a nominal capacity of 400 Ah. Through the excellent heat transfer characteristics of the MHPA, the heat generated by the charge and discharge process can be quickly transferred out of the battery module. In addition, if only the MHPA cannot meet the heat dissipation requirements of the battery module, the TMS can automatically control the opening of the external fan outside the battery module according to the temperature of the battery, so as to further enhance the heat dissipation of the battery module. The thermal management performance of lithium-ion battery TMS based on MHPA is studied experimentally under different ambient temperatures and the condition to turn on the fan or not. Results show that when the ambient temperature is 40 °C and the fan is not turned on in the whole charge and discharge process, the maximum temperature of the battery in the energy storage box is 53.1 °C and the maximum temperature difference in the battery module is 2.4 °C. After the fan is turned on in the whole charge and discharge process, the maximum temperature is reduced to 50.1 °C, and the maximum temperature difference is reduced to 1.7 °C. Obviously, the lithium-ion battery TMS based on MHPA not only could control the maximum temperature of the battery below 55 °C, but also ensure the excellent temperature uniformity of the battery module. In conclusion, the lithium-ion battery TMS based on MHPA can ensure the safe and stable operation of the battery energy storage box in high temperature environment.

Keywords: heat dissipation, lithium-ion battery thermal management, micro heat pipe array, temperature uniformity

Procedia PDF Downloads 181
269 The Experimental and Numerical Analysis of the Joining Processes for Air Conditioning Systems

Authors: M.St. Węglowski, D. Miara, S. Błacha, J. Dworak, J. Rykała, K. Kwieciński, J. Pikuła, G. Ziobro, A. Szafron, P. Zimierska-Nowak, M. Richert, P. Noga

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In the paper the results of welding of car’s air-conditioning elements are presented. These systems based on, mainly, the environmental unfriendly refrigerants. Thus, the producers of cars will have to stop using traditional refrigerant and to change it to carbon dioxide (R744). This refrigerant is environmental friendly. However, it should be noted that the air condition system working with R744 refrigerant operates at high temperature (up to 150 °C) and high pressure (up to 130 bar). These two parameters are much higher than for other refrigerants. Thus new materials, design as well as joining technologies are strongly needed for these systems. AISI 304 and 316L steels as well as aluminium alloys 5xxx are ranked among the prospective materials. As a joining process laser welding, plasma welding, electron beam welding as well as high rotary friction welding can be applied. In the study, the metallographic examination based on light microscopy as well as SEM was applied to estimate the quality of welded joints. The analysis of welding was supported by numerical modelling based on Sysweld software. The results indicated that using laser, plasma and electron beam welding, it is possible to obtain proper quality of welds in stainless steel. Moreover, high rotary friction welding allows to guarantee the metallic continuity in the aluminium welded area. The metallographic examination revealed that the grain growth in the heat affected zone (HAZ) in laser and electron beam welded joints were not observed. It is due to low heat input and short welding time. The grain growth and subgrains can be observed at room temperature when the solidification mode is austenitic. This caused low microstructural changes during solidification. The columnar grain structure was found in the weld metal. Meanwhile, the equiaxed grains were detected in the interface. The numerical modelling of laser welding process allowed to estimate the temperature profile in the welded joint as well as predicts the dimensions of welds. The agreement between FEM analysis and experimental data was achieved.  

Keywords: car’s air–conditioning, microstructure, numerical modelling, welding

Procedia PDF Downloads 408
268 Effects of Oil Pollution on Euryglossa orientalis and Psettodes erumei in the Persian Gulf

Authors: Majid Afkhami, Maryam Ehsanpour, Reza Khoshnood, Zahra Khoshnood, Rastin Afkhami

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Marine pollution is a global environmental problem. Different human activities on land, in the water and in the air contribute to the contamination of seawater, sediments and organisms with potentially toxic substances. Contaminants can be natural substances or artificially produced compounds. After discharge into the sea, contaminants can stay in the water in dissolved form or they can be removed from the water column through sedimentation to the bottom sediments. Histopathological alterations can be used as indicators for the effects of various anthropogenic pollutants on organisms and are a reflection of the overall health of the entire population in the ecosystem. These histo pathological biomarkers are closely related to other biomarkers of stress since many pollutants have to undergo metabolic activation in order to be able to provoke cellular change in the affected organism. In order to make evaluation of the effects of oil pollution, some heavy metals bioaccumulation and explore their histopathological effects on hepatocytes of Oriental sole (Euryglossa orientalis) and Deep flounder (Psettodes erumei), fishes caught from two areas of north coast of the Persian Gulf: Bandar Abbass and Bandar Lengeh. Concentrations of Ni and V in liver of both species in two sampling regions were in following order: Bandar abbass Bandar lengeh; also between two species, these quantities were higher in P. erumei than E. orientalis in both sampling regions. Histopathology of the liver shows some cellular alterations including: degeneration, necrosis and tissue disruption, and histopathological effects were severe in P. erumei than E. orientalis. Results showed that Bandar Abbass region was more polluted than Bandar Lengeh, and because Ni and V were oil pollution indicators, and two flat fishes were benthic, they can receive considerable amount of oil pollution through their biological activities like feeding. Also higher amounts of heavy metal concentrations and major histopathological effects in E. orientalis showed strong relationship between benthic habitat of the fish and amounts of received pollutants from water and sediments, because E. orientalis is more related to the bottom than P. erumei.

Keywords: heavy metals, flatfishes, Persian Gulf, oil pollution

Procedia PDF Downloads 345
267 Aerofloral Studies and Allergenicity Potentials of Dominant Atmospheric Pollen Types at Some Locations in Northwestern Nigeria

Authors: Olugbenga S. Alebiosu, Olusola H. Adekanmbi, Oluwatoyin T. Ogundipe

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Pollen and spores have been identified as major airborne bio-particles inducing respiratory disorders such as asthma, allergic rhinitis and atopic dermatitis among hypersensitive individuals. An aeropalynological study was conducted within a one year sampling period with a view to investigating the monthly depositional rate of atmospheric pollen and spores; influence of the immediate vegetation on airborne pollen distribution; allergenic potentials of dominant atmospheric pollen types at selected study locations in Bauchi and Taraba states, Northwestern Nigeria. A tauber-like pollen trap was employed in aerosampling with the sampler positioned at a height of 5 feet above the ground, followed by a monthly collection of the recipient solution for the sampling period. The collected samples were subjected to acetolysis treatment, examined microscopically with the identification of pollen grains and spores using reference materials and published photomicrographs. Plants within the surrounding vegetation were enumerated. Crude protein contents extracted from pollen types found to be commonly dominant at both study locations; Senna siamea, Terminalia cattapa, Panicum maximum and Zea mays were used to sensitize Musmusculus. Histopathological studies of bronchi and lung sections from certain dead M.musculus in the test groups was conducted. Blood samples were collected from the pre-orbital vein of M.musculus and processed for serological and haematological (differential and total white blood cell counts) studies. ELISA was used in determining the levels of serological parameters: IgE and cytokines (TNF-, IL-5, and IL-13). Statistical significance was observed in the correlation between the levels of serological and haematological parameters elicited by each test group, differences between the levels of serological and haematological parameters elicited by each test group and those of the control, as well as at varying sensitization periods. The results from this study revealed dominant airborne pollen types across the study locations; Syzygiumguineense, Tridaxprocumbens, Elaeisguineensis, Mimosa sp., Borreria sp., Terminalia sp., Senna sp. and Poaceae. Nephrolepis sp., Pteris sp. and a trilete fern also produced spores. This study also revealed that some of the airborne pollen types were produced by local plants at the study locations. Bronchi sections of M.musculus after first and second sensitizations, as well as lung section after first sensitization with Senna siamea, showed areas of necrosis. Statistical significance was recorded in the correlation between the levels of some serological and haematological parameters produced by each test group and those of the control, as well as at certain sensitization periods. The study revealed some candidate pollen allergens at the study locations allergy sufferers and also established a complexity of interaction between immune cells, IgE and cytokines at varied periods of mice sensitization and forming a paradigm of human immune response to different pollen allergens. However, it is expedient that further studies should be conducted on these candidate pollen allergens for their allergenicity potential in humans within their immediate environment.

Keywords: airborne, hypersensitive, mus musculus, pollen allergens, respiratory, tauber-like

Procedia PDF Downloads 135
266 In-situ Phytoremediation Of Polluted Soils By Micropollutants From Artisanal Gold Mining Processes In Burkina Faso

Authors: Yamma Rose, Kone Martine, Yonli Arsène, Wanko Ngnien Adrien

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Artisanal gold mining has seen a resurgence in recent years in Burkina Faso with its corollary of soil and water pollution. Indeed, in addition to visible impacts, it generates discharges rich in trace metal elements and acids. This pollution has significant environmental consequences, making these lands unusable while the population depends on the natural environment for its survival. The goal of this study is to assess the decontamination potential of Chrysopogon zizanioides on two artisanal gold processing sites in Burkina Faso. The cyanidation sites of Nebia (1Ha) and Nimbrogo (2Ha) located respectively in the Central West and Central South regions were selected. The soils were characterized to determine the initial pollution levels before the implementation of phytoremediation. After development of the site, parallel trenches equidistant 6 m apart, 30 cm deep, 40 cm wide and opposite to the water flow direction were dug and filled with earth amended with manure. The Chrysopogon zizanioides plants were transplanted 5 cm equidistant into the trenches. The mere fact that Chrysopogon zizanioides grew in the polluted soil is an indication that this plant tolerates and resists the toxicity of trace elements present on the site. The characterization shows sites very polluted with free cyanide 900 times higher than the national standard, the level of Hg in the soil is 5 times more than the limit value, iron and Zn are respectively 1000 times and 200 more than the tolerated environmental value. At time T1 (6 months) and T2 (12 months) of culture, Chrysopogon zizanioides showed less development on the Nimbrogo site than that of the Nebia site. Plant shoots and associated soil samples were collected and analyzed for total As, Hg, Fe and Zn concentration. The trace element content of the soil, the bioaccumulation factor and the hyper accumulation thresholds were also determined to assess the remediation potential. The concentration of As and Hg in the soil was below international risk thresholds, while that of Fe and Zn was well above these thresholds. The CN removal efficiency at the Nebia site is respectively 29.90% and 68.62% compared to 6.6% and 60.8% at Nimbrogo at time T1 and T2.

Keywords: chrysopogon zizanioides, in-situ phytoremediation, polluted soils, micropollutants

Procedia PDF Downloads 79
265 From Faces to Feelings: Exploring Emotional Contagion and Empathic Accuracy through the Enfacement Illusion

Authors: Ilenia Lanni, Claudia Del Gatto, Allegra Indraccolo, Riccardo Brunetti

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Empathy represents a multifaceted construct encompassing affective and cognitive components. Among these, empathic accuracy—defined as the ability to accurately infer another person’s emotions or mental state—plays a pivotal role in fostering empathetic understanding. Emotional contagion, the automatic process through which individuals mimic and synchronize facial expressions, vocalizations, and postures, is considered a foundational mechanism for empathy. This embodied simulation enables shared emotional experiences and facilitates the recognition of others’ emotional states, forming the basis of empathic accuracy. Facial mimicry, an integral part of emotional contagion, creates a physical and emotional resonance with others, underscoring its potential role in enhancing empathic understanding. Building on these findings, the present study explores how manipulating emotional contagion through the enfacement illusion impacts empathic accuracy, particularly in the recognition of complex emotional expressions. The enfacement illusion was implemented as a visuo-tactile multisensory manipulation, during which participants experienced synchronous and spatially congruent tactile stimulation on their own face while observing the same stimulation being applied to another person’s face. This manipulation enhances facial mimicry, which is hypothesized to play a key role in improving empathic accuracy. Following the enfacement illusion, participants completed a modified version of the Diagnostic Analysis of Nonverbal Accuracy–Form 2 (DANVA2-AF). The task included 48 images of adult faces expressing happiness, sadness, or morphed emotions blending neutral with happiness or sadness to increase recognition difficulty. These images featured both familiar and unfamiliar faces, with familiar faces belonging to the actors involved in the prior visuo-tactile stimulation. Participants were required to identify the target’s emotional state as either "happy" or "sad," with response accuracy and reaction times recorded. Results from this study indicate that emotional contagion, as manipulated through the enfacement illusion, significantly enhances empathic accuracy, particularly for the recognition of happiness. Participants demonstrated greater accuracy and faster response times in identifying happiness when viewing familiar faces compared to unfamiliar ones. These findings suggest that the enfacement illusion strengthens emotional resonance and facilitates the processing of positive emotions, which are inherently more likely to be shared and mimicked. Conversely, for the recognition of sadness, an opposite but non-significant trend was observed. Specifically, participants were slightly faster at recognizing sadness in unfamiliar faces compared to familiar ones. This pattern suggests potential differences in how positive and negative emotions are processed within the context of facial mimicry and emotional contagion, warranting further investigation. These results provide insights into the role of facial mimicry in emotional contagion and its selective impact on empathic accuracy. This study highlights how the enfacement illusion can precisely modulate the recognition of specific emotions, offering a deeper understanding of the mechanisms underlying empathy.

Keywords: empathy, emotional contagion, enfacement illusion, emotion recognition

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264 Effective Doping Engineering of Na₃V₂(PO₄)₂F₃ as a High-Performance Cathode Material for Sodium-Ion Batteries

Authors: Ramon Alberto Paredes Camacho, Li Lu

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Sustainable batteries are possible through the development of cheaper and greener alternatives whose most feasible option is epitomized by Sodium-Ion Batteries (SIB). Na₃V₂(PO₄)₂F₃ (NVPF) an important member of the Na-superionic-conductor (NASICON) materials, has recently been in the spotlight due to its interesting electrochemical properties when used as cathode namely, high specific capacity of 128 mA h g-¹, high energy density of 507 W h Kg-¹, increased working potential at which vanadium redox couples can be activated (with an average value around 3.9 V), and small volume variation of less than 2%. These traits grant NVPF an excellent perspective as a cathode material for the next generation of sodium batteries. Unfortunately, because of its low inherent electrical conductivity and a high energy barrier that impedes the mobilization of all the available Na ions per formula, the overall electrochemical performance suffers substantial degradation, finally obstructing its industrial use. Many approaches have been developed to remediate these issues where nanostructural design, carbon coating, and ion doping are the most effective ones. This investigation is focused on enhancing the electrochemical response of NVPF by doping metal ions in the crystal lattice, substituting vanadium atoms. A facile sol-gel process is employed, with citric acid as the chelator and the carbon source. The optimized conditions circumvent fluorine sublimation, ratifying the material’s purity. One of the reasons behind the large ionic improvement is the attraction of extra Na ions into the crystalline structure due to a charge imbalance produced by the valence of the doped ions (+2), which is lower than the one of vanadium (+3). Superior stability (higher than 90% at a current density of 20C) and capacity retention at an extremely high current density of 50C are demonstrated by our doped NVPF. This material continues to retain high capacity values at low and high temperatures. In addition, full cell NVPF//Hard Carbon shows capacity values and high stability at -20 and 60ºC. Our doping strategy proves to significantly increase the ionic and electronic conductivity of NVPF even at extreme conditions, delivering outstanding electrochemical performance and paving the way for advanced high-potential cathode materials.

Keywords: sodium-ion batteries, cathode materials, NASICON, Na3V2(PO4)2F3, Ion doping

Procedia PDF Downloads 57
263 Novel Nickel Complex Compound Reactivates the Apoptotic Network, Cell Cycle Arrest and Cytoskeletal Rearrangement in Human Colon and Breast Cancer Cells

Authors: Nima Samie, Batoul Sadat Haerian, Sekaran Muniandy, M. S. Kanthimathi

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Colon and breast cancers are categorized as the most prevalent types of cancer worldwide. Recently, the broad clinical application of metal complex compounds has led to the discovery of potential therapeutic drugs. The aim of this study was to evaluate the cytotoxic action of a selected nickel complex compound (NCC) against human colon and breast cancer cells. In this context, we determined the potency of the compound in the induction of apoptosis, cell cycle arrest, and cytoskeleton rearrangement. HT-29, WiDr, CCD-18Co, MCF-7 and Hs 190.T cell lines were used to determine the IC50 of the compound using the MTT assay. Analysis of apoptosis was carried out using immunofluorescence, acridine orange/ propidium iodide double staining, Annexin-V-FITC assay, evaluation of the translocation of NF-kB, oxygen radical antioxidant capacity, quenching of reactive oxygen species content , measurement of LDH release, caspase-3/-7, -8 and -9 assays and western blotting. The cell cycle arrest was examined using flowcytometry and gene expression was assessed using qPCR array. Results showed that our nickel complex compound displayed a potent suppressive effect on HT-29, WiDr, MCF-7 and Hs 190.T after 24 h of treatment with IC50 value of 2.02±0.54, 2.13±0.65, 3.76±015 and 3.14±0.45 µM respectively. This cytotoxic effect on normal cells was insignificant. Dipping in the mitochondrial membrane potential and increased release of cytochrome c from the mitochondria indicated induction of the intrinsic apoptosis pathway by the nickel complex compound. Activation of this pathway was further evidenced by significant activation of caspase 9 and 3/7.The nickel complex compound (NCC) was also shown activate the extrinsic pathways of apoptosis by activation of caspase-8 which is linked to the suppression of NF-kB translocation to the nucleus. Cell cycle arrest in the G1 phase and up-regulation of glutathione reductase, based on excessive ROS production were also observed. The results of this study suggest that the nickel complex compound is a potent anti-cancer agent inducing both intrinsic and extrinsic pathways as well as cell cycle arrest in colon and breast cancer cells.

Keywords: nickel complex, apoptosis, cytoskeletal rearrangement, colon cancer, breast cancer

Procedia PDF Downloads 313
262 Evaluation of Sugarcane Straw Derived Biochar for the Remediation of Chromium and Nickel Contaminated Soil

Authors: Selam M. Tefera

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Soil constitutes a crucial component of rural and urban environments. This fact is making role of heavy and trace elements in the soil system an issue of global concern. Heavy metals constitute an ill-defined group of inorganic chemical hazards, whose main source is anthropogenic activities mainly related to fabrications. This accumulation of heavy metals soils can prove toxic to the environment. The application of biochar to soil is one way of immobilizing these contaminants through sorption by exploiting the high surface area of this material among its other essential properties. This research examined the ability of sugar cane straw, an organic waste material from sugar farm, derived biochar and ash to remediate soil contaminated with heavy metals mainly Chromium and Zinc from the effluent of electroplating industry. Biochar was produced by varying the temperature from 300 °C to 500 °C and ash at 700 °C. The highest yield (50%) was obtained at the lowest temperature (300 °C). The proximate analysis showed ash content of 42.8%, ultimate analysis with carbon content of 67.18%, the Hydrogen to Carbon ratio of 0.54 and the results from FTIR analysis disclosed the organic nature of biochar. Methylene blue absorption indicated its fine surface area and pore structure, which increases with severity of temperature. Biochar was mixed with soil with at a ration varying from 4% w/w to 10% w/w of soil, and the response variables were determined at a time interval of 150 days, 180 days, and 210 days. As for ash (10% w/w), the characterization was performed at incubation time of 210 days. The results of pH indicated that biochar (9.24) had a notable liming capacity of acidic soil (4.8) by increasing it to 6.89 whereas ash increased it to 7.5. The immobilization capacity of biochar was found to effected mostly by the highest production temperature (500 °C), which was 75.5% for chromium and 80.5% for nickel. In addition, ash was shown to possess an outstanding immobilization capacity of 95.5% and 90.5% for Chromium and Nickel, respectively. All in all, the results from these methods showed that biochar produced from this specific biomass possesses the typical functional groups that enable it to store carbon, the appropriate pH that could remediate acidic soil, a fine amount of macro and micro nutrients that would aid plant growth.

Keywords: biochar, biomass, heavy metal immobalization, soil remediation

Procedia PDF Downloads 144
261 A First-Principles Molecular Dynamics Study on Li+ Solvation Structures in THF/MTHF Containing Electrolytes for Lithium Metal Batteries.

Authors: Chiu-Neng Su, Santhanamoorthi Nachimuthu, Jyh-Chiang Jiang

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In lithium-ion batteries (LIBs) the solid–electrolyte interphase (SEI) layer, which forms on the anode surface, plays a crucial role in stabilizing battery performance. Over the past two decades, efforts to enhance LIB electrolytes have primarily focused on refining the quality of SEI components. Despite these endeavors, several observed phenomena remain inadequately improved the SEI layer. Consequently, there has been a significant surge in research interest regarding the behavior of electrolyte solvation structures to elucidate improvements in battery performance. Thus, in this study, we aimed to explore the solvation structures of LiPF₆ in a mixture of organic solvents, tetrahydrofuran (THF) and 2-methyl-tetrahydrofuran (MTHF) using ab-initio molecular dynamics (AIMD) simulations. Our work investigated the solvation structure of electrolytes with different salt concentrations: low-concentration electrolyte (1.0M LiPF6 in 1:1v/v mixture of THF and MTHF), and high-concentration electrolyte (2.0M LiPF₆ in 1:1v/v mixture of THF and MTHF) and compared them with that of conventional electrolyte (1.0M LiPF₆ in 1:1v/v mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC)). Furthermore, the reduction stability of Li+ solvation structures in these electrolyte systems are investigated. It is found that the first solvation shell of Li+ primary consists of THF. We also analyzed the molecular orbital energy levels to understand the reducing stability of these solvents. Compared with the solvation sheath of commercial electrolyte, the THF/MTHF-containing electrolytes have a higher lowest unoccupied molecular orbital (LUMO) energy level, resulting in improved reduction and interface stability. It has been shown that Li-Al alloy can significantly improve cycle life and promote the formation of a dense SEI layer. Therefore, this study aims to construct the solvation structures obtained from calculations of the pure electrolyte system on the surface of Al-Li alloy. Additionally, AIMD simulations will be conducted to investigate chemical reactions at the interface. This investigation aims to elucidate the composition of the SEI layer formed. Furthermore, Bader charges are used to determine the origin and flow of electrons, thereby revealing the sequence of reduction reactions for generating SEI layers.

Keywords: lithium, aluminum, alloy, battery, solvation structure

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260 A Proposal of a Strategic Framework for the Development of Smart Cities: The Argentinian Case

Authors: Luis Castiella, Mariano Rueda, Catalina Palacio

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The world’s rapid urbanisation represents an excellent opportunity to implement initiatives that are oriented towards a country’s general development. However, this phenomenon has created considerable pressure on current urban models, pushing them nearer to a crisis. As a result, several factors usually associated with underdevelopment have been steadily rising. Moreover, actions taken by public authorities have not been able to keep up with the speed of urbanisation, which has impeded them from meeting the demands of society, responding with reactionary policies instead of with coordinated, organised efforts. In contrast, the concept of a Smart City which emerged around two decades ago, in principle, represents a city that utilises innovative technologies to remedy the everyday issues of the citizen, empowering them with the newest available technology and information. This concept has come to adopt a wider meaning, including human and social capital, as well as productivity, economic growth, quality of life, environment and participative governance. These developments have also disrupted the management of institutions such as academia, which have become key in generating scientific advancements that can solve pressing problems, and in forming a specialised class that is able to follow up on these breakthroughs. In this light, the Ministry of Modernisation of the Argentinian Nation has created a model that is rooted in the concept of a ‘Smart City’. This effort considered all the dimensions that are at play in an urban environment, with careful monitoring of each sub-dimensions in order to establish the government’s priorities and improving the effectiveness of its operations. In an attempt to ameliorate the overall efficiency of the country’s economic and social development, these focused initiatives have also encouraged citizen participation and the cooperation of the private sector: replacing short-sighted policies with some that are coherent and organised. This process was developed gradually. The first stage consisted in building the model’s structure; the second, at applying the method created on specific case studies and verifying that the mechanisms used respected the desired technical and social aspects. Finally, the third stage consists in the repetition and subsequent comparison of this experiment in order to measure the effects on the ‘treatment group’ over time. The first trial was conducted on 717 municipalities and evaluated the dimension of Governance. Results showed that levels of governmental maturity varied sharply with relation to size: cities with less than 150.000 people had a strikingly lower level of governmental maturity than cities with more than 150.000 people. With the help of this analysis, some important trends and target population were made apparent, which enabled the public administration to focus its efforts and increase its probability of being successful. It also permitted to cut costs, time, and create a dynamic framework in tune with the population’s demands, improving quality of life with sustained efforts to develop social and economic conditions within the territorial structure.

Keywords: composite index, comprehensive model, smart cities, strategic framework

Procedia PDF Downloads 178
259 Cleaning of Polycyclic Aromatic Hydrocarbons (PAH) Obtained from Ferroalloys Plant

Authors: Stefan Andersson, Balram Panjwani, Bernd Wittgens, Jan Erik Olsen

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Polycyclic Aromatic hydrocarbons are organic compounds consisting of only hydrogen and carbon aromatic rings. PAH are neutral, non-polar molecules that are produced due to incomplete combustion of organic matter. These compounds are carcinogenic and interact with biological nucleophiles to inhibit the normal metabolic functions of the cells. Norways, the most important sources of PAH pollution is considered to be aluminum plants, the metallurgical industry, offshore oil activity, transport, and wood burning. Stricter governmental regulations regarding emissions to the outer and internal environment combined with increased awareness of the potential health effects have motivated Norwegian metal industries to increase their efforts to reduce emissions considerably. One of the objective of the ongoing industry and Norwegian research council supported "SCORE" project is to reduce potential PAH emissions from an off gas stream of a ferroalloy furnace through controlled combustion. In a dedicated combustion chamber. The sizing and configuration of the combustion chamber depends on the combined properties of the bulk gas stream and the properties of the PAH itself. In order to achieve efficient and complete combustion the residence time and minimum temperature need to be optimized. For this design approach reliable kinetic data of the individual PAH-species and/or groups thereof are necessary. However, kinetic data on the combustion of PAH are difficult to obtain and there is only a limited number of studies. The paper presents an evaluation of the kinetic data for some of the PAH obtained from literature. In the present study, the oxidation is modelled for pure PAH and also for PAH mixed with process gas. Using a perfectly stirred reactor modelling approach the oxidation is modelled including advanced reaction kinetics to study influence of residence time and temperature on the conversion of PAH to CO2 and water. A Chemical Reactor Network (CRN) approach is developed to understand the oxidation of PAH inside the combustion chamber. Chemical reactor network modeling has been found to be a valuable tool in the evaluation of oxidation behavior of PAH under various conditions.

Keywords: PAH, PSR, energy recovery, ferro alloy furnace

Procedia PDF Downloads 273
258 Chronic Renal Failure Associated with Heavy Metal Contamination of Drinking Water in Hail, Kingdom of Saudi Arabia

Authors: Elsayed A. M. Shokr, A. Alhazemi, T. Naser, Talal A. Zuhair, Adel A. Zuhair, Ahmed N. Alshamary, Thamer A. Alanazi, Hosam A. Alanazi

Abstract:

The main threats to human health from heavy metals are associated with exposure to Pb, Cd, Cu, Mo, Zn, Ni, Mn Co and Cr. is mainly via intake of drinking water being the most important source in most populations. These metals have been extensively studied and their effects on human health regularly reviewed by international bodies such as the WHO. Heavy metals have been used by humans for thousands of years. Although several adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues, and is even increasing in some parts of the world, in particular in less developed countries, though emissions have declined in most developed countries over the last 100 years. A strong relationship between contaminated drinking water with heavy metals from some of the stations of water shopping in Hail, KSA and chronic diseases such as renal failure, liver cirrhosis, and chronic anemia has been identified in this study. These diseases are apparently related to contaminant drinking water with heavy metals such as Pb, Cd, Cu, Mo, Zn, Ni, Mn Co and Cr. Renal failure is related to contaminate drinking water with lead and cadmium, liver cirrhosis to copper and molybdenum, and chronic anemia to copper and cadmium. Recent data indicate that adverse health effects of cadmium exposure may occur at lower exposure levels than previously anticipated, primarily in the form of kidney damage but possibly also bone effects and fractures. The general population is primarily exposed to mercury via drinking water being a major source of methyl mercury exposure, and dental amalgam. During the last century lead, cadmium, zinc, iron and arsenic is mainly via intake of drinking water being the most important source in most populations. Long-term exposure to lead, cadmium, zinc, iron and arsenic in drinking-water is mainly related to primarily in the form of kidney damage. Studies of these diseases suggest that abnormal incidence in specific areas is related to toxic materials in the groundwater and thereby led to the contamination of drinking water in these areas.

Keywords: heavy metals, liver functions, kidney functions and chronic renal failure, hail, renal, water

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257 Cadmium Accumulation and Depuration Characteristics through Food Source of Cage-Cultivated Fish after Accidental Pollution in Longjiang River

Authors: Qianli Ma, Xuemin Zhao, Lingai Yao, Zhencheng Xu, Li Wang

Abstract:

Heavy metal pollution accidents, frequently happened in this decade in China, severely threaten aquatic ecosystem and economy. In January 2012, a basin-scale accidental Cd pollution happened in Longjiang River in southwest China. Although water quality was recovered in short period by emergency treatment with flocculants, a large amount of contaminated cage-cultivated fish were left with the task of preventing or mitigating Cd contamination of fish. In this study, unpolluted Ctenopharyngodon idellus were fed by Cd-contaminated macrophytes for assessing the effect of Cd accumulation through food exposure, and the contaminated C. idellus were fed with Cd-free macrophytes for assessing the ability of Cd depuration. The on-site cultivation experiments were done in two sites of Lalang (S1, accidental Cd pollution originated) and Sancha (S2, a large amount of flocculants were added to accelerate Cd precipitation) in Longjiang river. Results showed that Cd content in fish muscle presented an increasing trend in the accumulation experiment. In S1, Cd content of fish muscle rose sharply from day 8 to day 18 with higher average Cd content in macrophytes and sediment, and kept in the range of 0.208-0.308 mg/kg afterward. In S2, Cd content of fish muscle rose gradually throughout the experiment and reached the maximum level of 0.285 mg/kg on day 76. The results of the depuration experiment showed that Cd content in fish muscle decreased and significant changes were observed in the first half time of the experiment. Meanwhile, fish with lower initial Cd content presented higher elimination constant. In S1, Cd content of fish significantly decreased from 0.713 to 0.304 mg/kg in 18 days and kept decreasing to 0.110 mg/kg in the end, and 84.6% of Cd content was eliminated. While in S2, there was a sharp decrease of Cd content of fish in 0-8 days from 0.355 mg/kg to 0.069 mg/kg. The total elimination percentage was 93.8% and 80.6% of which appeared in day 0-8. The elimination constant of fish in S2 was 0.03 which was higher than 0.02 in S1. Collectively, our results showed Cd could be absorbed through food exposure and accumulate in fish muscle, and the accumulated Cd in fish muscle can be excreted after isolated from the polluted food sources. This knowledge allows managers to assess health risk of Cd contaminated fish and minimize aquaculture loss when considering fish cultivation after accidental pollution.

Keywords: accidental pollution, cadmium accumulation and depuration, cage-cultivated fish, environmental management, river

Procedia PDF Downloads 254
256 Analysis of Elastic-Plastic Deformation of Reinforced Concrete Shear-Wall Structures under Earthquake Excitations

Authors: Oleg Kabantsev, Karomatullo Umarov

Abstract:

The engineering analysis of earthquake consequences demonstrates a significantly different level of damage to load-bearing systems of different types. Buildings with reinforced concrete columns and separate shear-walls receive the highest level of damage. Traditional methods for predicting damage under earthquake excitations do not provide an answer to the question about the reasons for the increased vulnerability of reinforced concrete frames with shear-walls bearing systems. Thus, the study of the problem of formation and accumulation of damages in the structures reinforced concrete frame with shear-walls requires the use of new methods of assessment of the stress-strain state, as well as new approaches to the calculation of the distribution of forces and stresses in the load-bearing system based on account of various mechanisms of elastic-plastic deformation of reinforced concrete columns and walls. The results of research into the processes of non-linear deformation of structures with a transition to destruction (collapse) will allow to substantiate the characteristics of limit states of various structures forming an earthquake-resistant load-bearing system. The research of elastic-plastic deformation processes of reinforced concrete structures of frames with shear-walls is carried out on the basis of experimentally established parameters of limit deformations of concrete and reinforcement under dynamic excitations. Limit values of deformations are defined for conditions under which local damages of the maximum permissible level are formed in constructions. The research is performed by numerical methods using ETABS software. The research results indicate that under earthquake excitations, plastic deformations of various levels are formed in various groups of elements of the frame with the shear-wall load-bearing system. During the main period of seismic effects in the shear-wall elements of the load-bearing system, there are insignificant volumes of plastic deformations, which are significantly lower than the permissible level. At the same time, plastic deformations are formed in the columns and do not exceed the permissible value. At the final stage of seismic excitations in shear-walls, the level of plastic deformations reaches values corresponding to the plasticity coefficient of concrete , which is less than the maximum permissible value. Such volume of plastic deformations leads to an increase in general deformations of the bearing system. With the specified parameters of the deformation of the shear-walls in concrete columns, plastic deformations exceeding the limiting values develop, which leads to the collapse of such columns. Based on the results presented in this study, it can be concluded that the application seismic-force-reduction factor, common for the all load-bearing system, does not correspond to the real conditions of formation and accumulation of damages in elements of the load-bearing system. Using a single coefficient of seismic-force-reduction factor leads to errors in predicting the seismic resistance of reinforced concrete load-bearing systems. In order to provide the required level of seismic resistance buildings with reinforced concrete columns and separate shear-walls, it is necessary to use values of the coefficient of seismic-force-reduction factor differentiated by types of structural groups.1

Keywords: reinforced concrete structures, earthquake excitation, plasticity coefficients, seismic-force-reduction factor, nonlinear dynamic analysis

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