Search results for: traditional techniques
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 11155

Search results for: traditional techniques

685 Lightweight Sheet Molding Compound Composites by Coating Glass Fiber with Cellulose Nanocrystals

Authors: Amir Asadi, Karim Habib, Robert J. Moon, Kyriaki Kalaitzidou

Abstract:

There has been considerable interest in cellulose nanomaterials (CN) as polymer and polymer composites reinforcement due to their high specific modulus and strength, low density and toxicity, and accessible hydroxyl side groups that can be readily chemically modified. The focus of this study is making lightweight composites for better fuel efficiency and lower CO2 emission in auto industries with no compromise on mechanical performance using a scalable technique that can be easily integrated in sheet molding compound (SMC) manufacturing lines. Light weighting will be achieved by replacing part of the heavier components, i.e. glass fibers (GF), with a small amount of cellulose nanocrystals (CNC) in short GF/epoxy composites made using SMC. CNC will be introduced as coating of the GF rovings prior to their use in the SMC line. The employed coating method is similar to the fiber sizing technique commonly used and thus it can be easily scaled and integrated to industrial SMC lines. This will be an alternative route to the most techniques that involve dispersing CN in polymer matrix, in which the nanomaterials agglomeration limits the capability for scaling up in an industrial production. We have demonstrated that incorporating CNC as a coating on GF surface by immersing the GF in CNC aqueous suspensions, a simple and scalable technique, increases the interfacial shear strength (IFSS) by ~69% compared to the composites produced by uncoated GF, suggesting an enhancement of stress transfer across the GF/matrix interface. As a result of IFSS enhancement, incorporation of 0.17 wt% CNC in the composite results in increases of ~10% in both elastic modulus and tensile strength, and 40 % and 43 % in flexural modulus and strength respectively. We have also determined that dispersing 1.4 and 2 wt% CNC in the epoxy matrix of short GF/epoxy SMC composites by sonication allows removing 10 wt% GF with no penalty on tensile and flexural properties leading to 7.5% lighter composites. Although sonication is a scalable technique, it is not quite as simple and inexpensive as coating the GF by passing through an aqueous suspension of CNC. In this study, the above findings are integrated to 1) investigate the effect of CNC content on mechanical properties by passing the GF rovings through CNC aqueous suspension with various concentrations (0-5%) and 2) determine the optimum ratio of the added CNC to the removed GF to achieve the maximum possible weight reduction with no cost on mechanical performance of the SMC composites. The results of this study are of industrial relevance, providing a path toward producing high volume lightweight and mechanically enhanced SMC composites using cellulose nanomaterials.

Keywords: cellulose nanocrystals, light weight polymer-matrix composites, mechanical properties, sheet molding compound (SMC)

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684 Dimensionality Reduction in Modal Analysis for Structural Health Monitoring

Authors: Elia Favarelli, Enrico Testi, Andrea Giorgetti

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Autonomous structural health monitoring (SHM) of many structures and bridges became a topic of paramount importance for maintenance purposes and safety reasons. This paper proposes a set of machine learning (ML) tools to perform automatic feature selection and detection of anomalies in a bridge from vibrational data and compare different feature extraction schemes to increase the accuracy and reduce the amount of data collected. As a case study, the Z-24 bridge is considered because of the extensive database of accelerometric data in both standard and damaged conditions. The proposed framework starts from the first four fundamental frequencies extracted through operational modal analysis (OMA) and clustering, followed by density-based time-domain filtering (tracking). The fundamental frequencies extracted are then fed to a dimensionality reduction block implemented through two different approaches: feature selection (intelligent multiplexer) that tries to estimate the most reliable frequencies based on the evaluation of some statistical features (i.e., mean value, variance, kurtosis), and feature extraction (auto-associative neural network (ANN)) that combine the fundamental frequencies to extract new damage sensitive features in a low dimensional feature space. Finally, one class classifier (OCC) algorithms perform anomaly detection, trained with standard condition points, and tested with normal and anomaly ones. In particular, a new anomaly detector strategy is proposed, namely one class classifier neural network two (OCCNN2), which exploit the classification capability of standard classifiers in an anomaly detection problem, finding the standard class (the boundary of the features space in normal operating conditions) through a two-step approach: coarse and fine boundary estimation. The coarse estimation uses classics OCC techniques, while the fine estimation is performed through a feedforward neural network (NN) trained that exploits the boundaries estimated in the coarse step. The detection algorithms vare then compared with known methods based on principal component analysis (PCA), kernel principal component analysis (KPCA), and auto-associative neural network (ANN). In many cases, the proposed solution increases the performance with respect to the standard OCC algorithms in terms of F1 score and accuracy. In particular, by evaluating the correct features, the anomaly can be detected with accuracy and an F1 score greater than 96% with the proposed method.

Keywords: anomaly detection, frequencies selection, modal analysis, neural network, sensor network, structural health monitoring, vibration measurement

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683 Fly ash Contamination in Groundwater and its Implications on Local Climate Change

Authors: Rajkumar Ghosh

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Fly ash, a byproduct of coal combustion, has become a prevalent environmental concern due to its potential impact on both groundwater quality and local climate change. This study aims to provide an in-depth analysis of the various mechanisms through which fly ash contaminates groundwater, as well as the possible consequences of this contamination on local climate change. The presence of fly ash in groundwater not only poses a risk to human health but also has the potential to influence local climate change through complex interactions. Although fly ash has various applications in construction and other industries, improper disposal and lack of containment measures have led to its infiltration into groundwater systems. Through a comprehensive review of existing literature and case studies, the interactions between fly ash and groundwater systems, assess the effects on hydrology, and discuss the implications for the broader climate. This section reviews the pathways through which fly ash enters groundwater, including leaching from disposal sites, infiltration through soil, and migration from surface water bodies. The physical and chemical characteristics of fly ash that contribute to its mobility and persistence in groundwater. The introduction of fly ash into groundwater can alter its chemical composition, leading to an increase in the concentration of heavy metals, metalloids, and other potentially toxic elements. The mechanisms of contaminant transport and highlight the potential risks to human health and ecosystems. Fly ash contamination in groundwater may influence the hydrological cycle through changes in groundwater recharge, discharge, and flow dynamics. This section examines the implications of altered hydrology on local water availability, aquatic habitats, and overall ecosystem health. The presence of fly ash in groundwater may have direct and indirect effects on local climate change. The role of fly ash as a potent greenhouse gas absorber and its contribution to radiative forcing. Additionally, investigation of the possible feedback mechanisms between groundwater contamination and climate change, such as altered vegetation patterns and changes in local temperature and precipitation patterns. In this section, potential mitigation and remediation techniques to minimize fly ash contamination in groundwater are analyzed. These may include improved waste management practices, engineered barriers, groundwater remediation technologies, and sustainable fly ash utilization. This paper highlights the critical link between fly ash contamination in groundwater and its potential contribution to local climate change. It emphasizes the importance of addressing this issue promptly through a combination of preventive measures, effective management strategies, and continuous monitoring. By understanding the interconnections between fly ash contamination, groundwater quality, and local climate, towards creating a more resilient and sustainable environment for future generations. The findings of this research can assist policymakers and environmental managers in formulating sustainable strategies to mitigate fly ash contamination and minimize its contribution to climate change.

Keywords: groundwater, climate, sustainable environment, fly ash contamination

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682 The Role of Virtual Reality in Mediating the Vulnerability of Distant Suffering: Distance, Agency, and the Hierarchies of Human Life

Authors: Z. Xu

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Immersive virtual reality (VR) has gained momentum in humanitarian communication due to its utopian promises of co-presence, immediacy, and transcendence. These potential benefits have led the United Nations (UN) to tirelessly produce and distribute VR series to evoke global empathy and encourage policymakers, philanthropic business tycoons and citizens around the world to actually do something (i.e. give a donation). However, it is unclear whether or not VR can cultivate cosmopolitans with a sense of social responsibility towards the geographically, socially/culturally and morally mediated misfortune of faraway others. Drawing upon existing works on the mediation of distant suffering, this article constructs an analytical framework to articulate the issue. Applying this framework on a case study of five of the UN’s VR pieces, the article identifies three paradoxes that exist between cyber-utopian and cyber-dystopian narratives. In the “paradox of distance”, VR relies on the notions of “presence” and “storyliving” to implicitly link audiences spatially and temporally to distant suffering, creating global connectivity and reducing perceived distances between audiences and others; yet it also enables audiences to fully occupy the point of view of distant sufferers (creating too close/absolute proximity), which may cause them to feel naive self-righteousness or narcissism with their pleasures and desire, thereby destroying the “proper distance”. In the “paradox of agency”, VR simulates a superficially “real” encounter for visual intimacy, thereby establishing an “audiences–beneficiary” relationship in humanitarian communication; yet in this case the mediated hyperreality is not an authentic reality, and its simulation does not fill the gap between reality and the virtual world. In the “paradox of the hierarchies of human life”, VR enables an audience to experience virtually fundamental “freedom”, epitomizing an attitude of cultural relativism that informs a great deal of contemporary multiculturalism, providing vast possibilities for a more egalitarian representation of distant sufferers; yet it also takes the spectator’s personally empathic feelings as the focus of intervention, rather than structural inequality and political exclusion (an economic and political power relations of viewing). Thus, the audience can potentially remain trapped within the minefield of hegemonic humanitarianism. This study is significant in two respects. First, it advances the turn of digitalization in studies of media and morality in the polymedia milieu; it is motivated by the necessary call for a move beyond traditional technological environments to arrive at a more novel understanding of the asymmetry of power between the safety of spectators and the vulnerability of mediated sufferers. Second, it not only reminds humanitarian journalists and NGOs that they should not rely entirely on the richer news experience or powerful response-ability enabled by VR to gain a “moral bond” with distant sufferers, but also argues that when fully-fledged VR technology is developed, it can serve as a kind of alchemy and should not be underestimated merely as a “bugaboo” of an alarmist philosophical and fictional dystopia.

Keywords: audience, cosmopolitan, distant suffering, virtual reality, humanitarian communication

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681 The Impact of Improved Grain Storage Technology on Marketing Behaviour and Livelihoods of Maize Farmers: A Randomized Controlled Trial in Ethiopia

Authors: Betelhem M. Negede, Maarten Voors, Hugo De Groote, Bart Minten

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Farmers in Ethiopia produce most of their own food during one agricultural season per year. Therefore, they need to use on-farm storage technologies to bridge the lean season and benefit from price arbitrage. Maize stored using traditional storage bags offer no protection from insects and molds, leading to high storage losses. In Ethiopia access to and use of modern storage technologies are still limited, restraining farmers to benefit from local maize price fluctuations. We used a randomized controlled trial among 871 maize farmers to evaluate the impacts of Purdue Improved Crop Storage (PICS) bags, also known as hermetic bags, on storage losses, and especially on behavioral changes with respect to consumption, marketing, and income among maize farmers in Ethiopia. This study builds upon the limited previous experimental research that has tried to understand farmers’ grain storage and post-harvest losses and identify mechanisms behind the persistence of these challenges. Our main hypothesis is that access to PICS bags allows farmers to increase production, storage and maize income. Also delay the length of maize storage, reduce maize post-harvest losses and improve their food security. Our results show that even though farmers received only three PICS bags that represent 10percent of their total maize stored, they delay their length of maize storage for sales by two weeks. However, we find no treatment effect on maize income, suggesting that the arbitrage of two weeks is too small. Also, we do not find any reduction in storage losses due to farmers’ reaction by selling early and by using cheap and readily available but potentially harmful storage chemicals. Looking at the heterogeneity treatment effects between the treatment variable and highland and lowland villages, we find a decrease in the percentage of maize stored by 4 percent in the highland villages. This confirms that location specific factors, such as agro-ecology and proximity to markets are important factors that influence whether and how much of the harvest a farmer stores. These findings highlight the benefits of hermetic storage bags, by allowing farmers to make inter-temporal arbitrage and by reducing potential health risks from storage chemicals. The main policy recommendation that emanates from our study is that postharvest losses reduction throughout the whole value chain is an important pathway to food and income security in Sub-Saharan Africa (SSA). However, future storage loss interventions with hermetic storage technologies should take into account the agro-ecology of the study area and quantify storage losses beyond farmers self-reported losses, such as the count and weigh method. Finally, studies on hermetic storage technologies indicate positive impacts on post-harvest losses and in improving food security, but the adoption and use of these technologies is currently still low in SSA. Therefore, future works on the scaling up of hermetic bags, should consider reasons why farmers only use PICS bags to store grains for consumption, which is usually related to a safety-first approach or due to lack of incentives (higher price from maize not treated with chemicals), and no grain quality check.

Keywords: arbitrage, PICS hermetic bags, post-harvest storage loss, RCT

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680 Industrial Hemp Agronomy and Fibre Value Chain in Pakistan: Current Progress, Challenges, and Prospects

Authors: Saddam Hussain, Ghadeer Mohsen Albadrani

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Pakistan is one of the most vulnerable countries to climate change. Being a country where 23% of the country’s GDP relies on agriculture, this is a serious cause of concern. Introducing industrial hemp in Pakistan can help build climate resilience in the agricultural sector of the country, as hemp has recently emerged as a sustainable, eco-friendly, resource-efficient, and climate-resilient crop globally. Hemp has the potential to absorb huge amounts of CO₂, nourish the soil, and be used to create various biodegradable and eco-friendly products. Hemp is twice as effective as trees at absorbing and locking up carbon, with 1 hectare (2.5 acres) of hemp reckoned to absorb 8 to 22 tonnes of CO₂ a year, more than any woodland. Along with its high carbon-sequestration ability, it produces higher biomass and can be successfully grown as a cover crop. Hemp can grow in almost all soil conditions and does not require pesticides. It has fast-growing qualities and needs only 120 days to be ready for harvest. Compared with cotton, hemp requires 50% less water to grow and can produce three times higher fiber yield with a lower ecological footprint. Recently, the Government of Pakistan has allowed the cultivation of industrial hemp for industrial and medicinal purposes, making it possible for hemp to be reinserted into the country’s economy. Pakistan’s agro-climatic and edaphic conditions are well-suitable to produce industrial hemp, and its cultivation can bring economic benefits to the country. Pakistan can enter global markets as a new exporter of hemp products. The production of hemp in Pakistan can be most exciting to the workforce, especially for farmers participating in hemp markets. The minimum production cost of hemp makes it affordable to small holding farmers, especially those who need their cropping system to be as highly sustainable as possible. Dr. Saddam Hussain is leading the first pilot project of Industrial Hemp in Pakistan. In the past three years, he has been able to recruit high-impact research grants on industrial hemp as Principal Investigator. He has already screened the non-toxic hemp genotypes, tested the adaptability of exotic material in various agroecological conditions, formulated the production agronomy, and successfully developed the complete value chain. He has developed prototypes (fabric, denim, knitwear) using hemp fibre in collaboration with industrial partners and has optimized the indigenous fibre processing techniques. In this lecture, Dr. Hussain will talk on hemp agronomy and its complete fibre value chain. He will discuss the current progress, and will highlight the major challenges and future research direction on hemp research.

Keywords: industrial hemp, agricultural sustainability, agronomic evaluation, hemp value chain

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679 Amorphous Aluminophosphates: An Insight to the Changes in Structural Properties and Catalytic Activity by the Incorporation of Transition Metals

Authors: A. Hamza, H. Kathyayini, N. Nagaraju

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Aluminophosphates, both amorphous and crystalline materials find applications as adsorbents, ceramics, and pigments and as catalysts/catalyst supports in organic fine chemical synthesis. Most of the applications are varied depending on the type of metal incorporated, particle size, surface area, porosity and morphology of aluminophosphate. The porous and surface properties of these materials are normally fine-tuned by adopting various preparation methodologies. Numerous crystalline microporous and mesoporous aluminophosphates and metal-aluminophosphates have been reported in literature, in which the synthesis has been carried out by using structure directing organic molecules/surfactants. In present work, amorphous aluminophosphate (AlP) and metal-aluminophosphates MAlP (M = Cu, Zn, Cr, Fe, Ce and Zr) and their mixed forms M-1M2AlP are prepared under a typical precipitation condition, i.e. at low temperature in order to keep the Von-Weirmann relative super saturation of the precipitating medium and obtain small size precipitate particles. These materials are prepared without using any surfactants. All materials are thoroughly characterised for surface and bulk properties by N2 adsorption-desorption technique, XRD, FT-IR, TG and SEM. The materials are also analysed for the amount and the strength of their surface acid sites, by NH3-TPD and CO2-TPD techniques respectively. All the materials prepared in the work are investigated for their catalytic activity in following applications in the synthesis of industrially important Jasminaldehyde via, aldol condensation of n-heptanal and benzaldehyde, in the synthesis of biologically important chalcones by Claisen-shmidth condensation of benzaldehyde and substituted chalcones. The effect of the amount of the catalysts, duration of the reaction, temperature of the reaction, molar ratio of the reactants has been studied. The porosity of pure aluminophosphate is found to be changed significantly by the incorporation of transition metals during preparation of aluminophosphate. The pore size increased from microporous to mesoporous and finally to macroporous by following order of metals Cu = Zn < Cr < Ce < Fe = Zr. The change in surface area and porosity of double metal-aluminophosphates depended on the concentration of both the metals. The acidity of aluminophosphate is either increased or decreased which depended on the type and valence of metals loaded. A good number of basic sites are created in metal-aluminophosphates irrespective of the metals used. A maximum catalytic activity for synthesis of both jasminaldehyde and chalcone is obtained by FeAlP as catalysts; these materials are characterized by decreased strength and concentration of acidic sites with optimum level basic sites.

Keywords: amorphous metal-aluminophosphates, surface properties, acidic-basic properties, Aldol, Claisen-Shmidth condensation, jasminaldehyde, chalcone

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678 Songwriting in the Postdigital Age: Using TikTok and Instagram as Online Informal Learning Technologies

Authors: Matthias Haenisch, Marc Godau, Julia Barreiro, Dominik Maxelon

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In times of ubiquitous digitalization and the increasing entanglement of humans and technologies in musical practices in the 21st century, it is to be asked, how popular musicians learn in the (post)digital Age. Against the backdrop of the increasing interest in transferring informal learning practices into formal settings of music education the interdisciplinary research association »MusCoDA – Musical Communities in the (Post)Digital Age« (University of Erfurt/University of Applied Sciences Clara Hoffbauer Potsdam, funded by the German Ministry of Education and Research, pursues the goal to derive an empirical model of collective songwriting practices from the study of informal lelearningf songwriters and bands that can be translated into pedagogical concepts for music education in schools. Drawing on concepts from Community of Musical Practice and Actor Network Theory, lelearnings considered not only as social practice and as participation in online and offline communities, but also as an effect of heterogeneous networks composed of human and non-human actors. Learning is not seen as an individual, cognitive process, but as the formation and transformation of actor networks, i.e., as a practice of assembling and mediating humans and technologies. Based on video stimulated recall interviews and videography of online and offline activities, songwriting practices are followed from the initial idea to different forms of performance and distribution. The data evaluation combines coding and mapping methods of Grounded Theory Methodology and Situational Analysis. This results in network maps in which both the temporality of creative practices and the material and spatial relations of human and technological actors are reconstructed. In addition, positional analyses document the power relations between the participants that structure the learning process of the field. In the area of online informal lelearninginitial key research findings reveal a transformation of the learning subject through the specific technological affordances of TikTok and Instagram and the accompanying changes in the learning practices of the corresponding online communities. Learning is explicitly shaped by the material agency of online tools and features and the social practices entangled with these technologies. Thus, any human online community member can be invited to directly intervene in creative decisions that contribute to the further compositional and structural development of songs. At the same time, participants can provide each other with intimate insights into songwriting processes in progress and have the opportunity to perform together with strangers and idols. Online Lelearnings characterized by an increase in social proximity, distribution of creative agency and informational exchange between participants. While it seems obvious that traditional notions not only of lelearningut also of the learning subject cannot be maintained, the question arises, how exactly the observed informal learning practices and the subject that emerges from the use of social media as online learning technologies can be transferred into contexts of formal learning

Keywords: informal learning, postdigitality, songwriting, actor-network theory, community of musical practice, social media, TikTok, Instagram, apps

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677 Effect of Tooth Bleaching Agents on Enamel Demineralisation

Authors: Najlaa Yousef Qusti, Steven J. Brookes, Paul A. Brunton

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Background: Tooth discoloration can be an aesthetic problem, and tooth whitening using carbamide peroxide bleaching agents are a popular treatment option. However, there are concerns about possible adverse effects such as demineralisation of the bleached enamel; however, the cause of this demineralisation is unclear. Introduction: Teeth can become stained or discoloured over time. Tooth whitening is an aesthetic solution for tooth discoloration. Bleaching solutions of 10% carbamide peroxide (CP) have become the standard agent used in dentist-prescribed and home-applied ’vital bleaching techniques’. These materials release hydrogen peroxide (H₂O₂), the active whitening agent. However, there is controversy in the literature regarding the effect of bleaching agents on enamel integrity and enamel mineral content. The purpose of this study was to establish if carbamide peroxide bleaching agents affect the acid solubility of enamel (i.e., make teeth more prone to demineralisation). Materials and Methods: Twelve human premolar teeth were sectioned longitudinally along the midline and varnished to leave the natural enamel surface exposed. The baseline behavior of each tooth half in relation to its demineralisation in acid was established by sequential exposure to 4 vials containing 1ml of 10mM acetic acid (1 minute/vial). This was followed by exposure to 10% CP for 8 hours. After washing in distilled water, the tooth half was sequentially exposed to 4 further vials containing acid to test if the acid susceptibility of the enamel had been affected. The corresponding tooth half acted as a control and was exposed to distilled water instead of CP. The mineral loss was determined by measuring [Ca²⁺] and [PO₄³⁻] released in each vial using a calcium ion-selective electrode and the phosphomolybdenum blue method, respectively. The effect of bleaching on the tooth surfaces was also examined using SEM. Results: Exposure to carbamide peroxide did not significantly alter the susceptibility of enamel to acid attack, and SEM of the enamel surface revealed a slight alteration in surface appearance. SEM images of the control enamel surface showed a flat enamel surface with some shallow pits, whereas the bleached enamel appeared with an increase in surface porosity and some areas of mild erosion. Conclusions: Exposure to H₂O₂ equivalent to 10% CP does not significantly increase subsequent acid susceptibility of enamel as determined by Ca²⁺ release from the enamel surface. The effects of bleaching on mineral loss were indistinguishable from distilled water in the experimental system used. However, some surface differences were observed by SEM. The phosphomolybdenum blue method for phosphate is compromised by peroxide bleaching agents due to their oxidising properties. However, the Ca²⁺ electrode is unaffected by oxidising agents and can be used to determine the mineral loss in the presence of peroxides.

Keywords: bleaching, carbamide peroxide, demineralisation, teeth whitening

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676 Spatial Pattern of Environmental Noise Levels and Auditory Ailments in Abeokuta Metropolis, Southwestern Nigeria

Authors: Olusegun Oguntoke, Aramide Y. Tijani, Olayide R. Adetunji

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Environmental noise has become a major threat to the quality of human life, and it is generally more severe in cities. This study assessed the level of environmental noise, mapped the spatial pattern at different times of the day and examined the association with morbidity of auditory ailments in Abeokuta metropolis. The entire metropolis was divided into 80 cells (areas) of 1000 m by 1000 m; out of which 33 were randomly selected for noise levels assessment. Portable noise meter (AR824) was used to measure noise level, and Global Positioning System (Garmin GPS-72H) was employed to take the coordinates of the sample sites for mapping. Risk map of the noise levels was produced using Kriging interpolation techniques based on the spatial spread of measured noise values across the study area. Data on cases of hearing impairments were collected from four major hospitals in the city. Data collected from field measurements and medical records were subjected to descriptive (frequency and percentage) and inferential (mean, ANOVA and correlation) statistics using SPSS (version 20.0). ArcMap 10.1 was employed for spatial analysis and mapping. Results showed mean noise levels range at morning (42.4 ± 4.14 – 88.2 ± 15.1 dBA), afternoon (45.0 ± 6.72– 86.4 ± 12.5 dBA) and evening (51.0 ± 6.55–84.4 ± 5.19 dBA) across the study area. The interpolated maps identified Kuto, Okelowo, Isale-Igbein, and Sapon as high noise risk areas. These are the central business district and nucleus of Abeokuta metropolis where commercial activities, high traffic volume, and clustered buildings exist. The monitored noise levels varied significantly among the sampled areas in the morning, afternoon and evening (p < 0.05). A significant correlation was found between diagnosed cases of auditory ailments and noise levels measured in the morning (r=0.39 at p < 0.05). Common auditory ailments found across the metropolis included impaired hearing (25.8%), tinnitus (16.4%) and otitis (15.0%). The most affected age groups were between 11-30 years while the male gender had more cases of hearing impairments (51.2%) than the females. The study revealed that environmental noise levels exceeded the recommended standards in the morning, afternoon and evening in 60.6%, 61% and 72.7% of the sampled areas respectively. Summarily, environmental noise in the study area is high and contributes to the morbidity of auditory ailments. Areas identified as hot spots of noise pollution should be avoided in the location of noise sensitive activities while environmental noise monitoring should be included as part of the mandate of the regulatory agencies in Nigeria.

Keywords: noise pollution, associative analysis, auditory impairment, urban, human exposure

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675 Broad Survey of Fine Root Traits to Investigate the Root Economic Spectrum Hypothesis and Plant-Fire Dynamics Worldwide

Authors: Jacob Lewis Watts, Adam F. A. Pellegrini

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Prairies, grasslands, and forests cover an expansive portion of the world’s surface and contribute significantly to Earth’s carbon cycle. The largest driver of carbon dynamics in some of these ecosystems is fire. As the global climate changes, most fire-dominated ecosystems will experience increased fire frequency and intensity, leading to increased carbon flux into the atmosphere and soil nutrient depletion. The plant communities associated with different fire regimes are important for reassimilation of carbon lost during fire and soil recovery. More frequent fires promote conservative plant functional traits aboveground; however, belowground fine root traits are poorly explored and arguably more important drivers of ecosystem function as the primary interface between the soil and plant. The root economic spectrum (RES) hypothesis describes single-dimensional covariation between important fine-root traits along a range of plant strategies from acquisitive to conservative – parallel to the well-established leaf economic spectrum (LES). However, because of the paucity of root trait data, the complex nature of the rhizosphere, and the phylogenetic conservatism of root traits, it is unknown whether the RES hypothesis accurately describes plant nutrient and water acquisition strategies. This project utilizesplants grown in common garden conditions in the Cambridge University Botanic Garden and a meta-analysis of long-term fire manipulation experiments to examine the belowground physiological traits of fire-adapted and non-fire-adapted herbaceous species to 1) test the RES hypothesis and 2) describe the effect of fire regimes on fine root functional traits – which in turn affect carbon and nutrient cycling. A suite of morphological, chemical, and biological root traits (e.g. root diameter, specific root length, percent N, percent mycorrhizal colonization, etc.) of 50 herbaceous species were measuredand tested for phylogenetic conservatism and RES dimensionality. Fire-adapted and non-fire-adapted plants traits were compared using phylogenetic PCA techniques. Preliminary evidence suggests that phylogenetic conservatism may weaken the single-dimensionality of the RES, suggesting that there may not be a single way that plants optimize nutrient and water acquisition and storage in the complex rhizosphere; additionally, fire-adapted species are expected to be more conservative than non-fire-adapted species, which may be indicative of slower carbon cycling with increasing fire frequency and intensity.

Keywords: climate change, fire regimes, root economic spectrum, fine roots

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674 Necessity for a Standardized Occupational Health and Safety Management System: An Exploratory Study from the Danish Offshore Wind Sector

Authors: Dewan Ahsan

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Denmark is well ahead in generating electricity from renewable sources. The offshore wind sector is playing the pivotal role to achieve this target. Though there is a rapid growth of offshore wind sector in Denmark, still there is a dearth of synchronization in OHS (occupational health and safety) regulation and standards. Therefore, this paper attempts to ascertain: i) what are the major challenges of the company specific OHS standards? ii) why does the offshore wind industry need a standardized OHS management system? and iii) who can play the key role in this process? To achieve these objectives, this research applies the interview and survey techniques. This study has identified several key challenges in OHS management system which are; gaps in coordination and communication among the stakeholders, gaps in incident reporting systems, absence of a harmonized OHS standard and blame culture. Furthermore, this research has identified eleven key stakeholders who are actively involve with the offshore wind business in Denmark. As noticed, the relationships among these stakeholders are very complex specially between operators and sub-contractors. The respondent technicians are concerned with the compliance of various third-party OHS standards (e.g. ISO 31000, ISO 29400, Good practice guidelines by G+) which are applying by various offshore companies. On top of these standards, operators also impose their own OHS standards. From the technicians point of angle, many of these standards are not even specific for the offshore wind sector. So, it is a big challenge for the technicians and sub-contractors to comply with different company specific standards which also elevate the price of their services offer to the operators. For instance, when a sub-contractor is competing for a bidding, it must fulfill a number of OHS requirements (which demands many extra documantions) set by the individual operator and/the turbine supplier. According to sub-contractors’ point of view these extra works consume too much time to prepare the bidding documents and they also need to train their employees to pass the specific OHS certification courses to accomplish the demand for individual clients and individual project. The sub-contractors argued that in many cases these extra documentations and OHS certificates are inessential to ensure the quality service. So, a standardized OHS management procedure (which could be applicable for all the clients) can easily solve this problem. In conclusion, this study highlights that i) development of a harmonized OHS standard applicable for all the operators and turbine suppliers, ii) encouragement of technicians’ active participation in the OHS management, iii) development of a good safety leadership, and, iv) sharing of experiences among the stakeholders (specially operators-operators-sub contractors) are the most vital strategies to overcome the existing challenges and to achieve the goal of 'zero accident/harm' in the offshore wind industry.

Keywords: green energy, offshore, safety, Denmark

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673 Petrology and Finite Strain of the Al Amar Region, Northern Ar-Rayn Terrane, Eastern Arabian Shield, Saudi Arabia

Authors: Lami Mohammed, Hussain J. Al Faifi, Abdel Aziz Al Bassam, Osama M. K. Kassem

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The Neoproterozoic basement rocks of the Ar Rayn terrane have been identified as parts of the Eastern Arabian Shield. It focuses on the petrological and finite strain properties to display the tectonic setting of the Al Amar suture for high deformed volcanic and granitoids rocks. The volcanic rocks are classified into two major series: the eastern side cycle, which includes dacite, rhyodacite, rhyolite, and ignimbrites, and the western side cycle, which includes andesite and pyroclastics. Granitoids rocks also contain monzodiorite, tonalite, granodiorite, and alkali-feldspar granite. To evaluate the proportions of shear contributions in penetratively deformed rocks. Asymmetrical porphyroclast and sigmoidal structural markers along the suture's strike, namely the Al Amar, are expected to reveal strain factors. The Rf/phi and Fry techniques are used to characterize quartz and feldspar porphyroclast, biotite, and hornblende grains in Abt schist, high deformed volcanic rock, and granitoids. The findings exposed that these rocks had experienced shape flattening, finite strain accumulation, and overall volume loss. The magnitude of the strain appears to increase across the nappe contacts with neighboring lithologies. Subhorizontal foliation likely developed in tandem with thrusting and nappe stacking, almost parallel to tectonic contacts. The ductile strain accumulation that occurred during thrusting along the Al Amar suture mostly includes a considerable pure shear component. Progressive thrusting by overlaid transpression and oblique convergence is shown by stacked nappes and diagonal stretching lineations along the thrust axes. The subhorizontal lineation might be the result of the suture's most recent activity. The current study's findings contradict the widely accepted model that links orogen-scale structures in the Arabian Shield to oblique convergence with dominant simple shear deformation. A significant pure shear component/crustal thickening increment should have played a significant role in the evolution of the suture and thus in the Shield's overall deformation history. This foliation was primarily generated by thrusting nappes together, showing that nappe stacking was linked to substantial vertical shortening induced by the active Al Amar suture on a massive scale.

Keywords: petrology, finite strain analysis, al amar region, ar-rayn terrane, Arabian shield

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672 Buddhist Cognitive Behavioral Therapy to Address Depression Among Elderly Population: Multi-cultural Model of Buddhist Based Cognitive Behavioral Therapy to Address Depression Among Elderly Population

Authors: Ashoke Priyadarshana Premananda

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As per the suggestions of previously conducted research in Counseling Psychology, the necessity of forming culture- friendly approaches has been strongly emphasized by a number of scholars in the field. In response to that, Multicultural-model of Buddhist Based Cognitive Behavioral Therapy (MMBCBT) has been formed as a culture-friendly therapeutic approach to address psychological disturbances (depression) in late adulthood. Elderly population in the world is on the rise by leaps and bounds, and forming a culture-based therapeutic model which is blended with Buddhist teachings has been the major objective of the study. Buddhist teachings and cultural applications, which were mapped onto Cognitive Behavioral Therapy (CBT) in the West, ultimately resulted in MMBCBT. Therefore, MMBCBT is a blend of cultural therapeutic techniques and the essence of certain Buddhist teachings extracted from five crucial suttas, which include CBT principles. In the process of mapping, MeghiyaSutta, GirimānandaSutta, SallekhaSutta, DvedhāvitakkaSutta, and Vitakka- SaṇṭhānaSutta have been taken into consideration mainly because of their cognitive behavioral content. The practical components of Vitakka- Saṇṭhānasutta (Aññanimittapabbaṃ) and Sallekhasutta (SallekhaPariyāya and CittuppādaPariyāya) have been used in the model while mindfulness of breathing was also carried out with the participants. Basically, multi-cultural therapeutic approaches of MMBCBT aim at modifying behavior (behavioral modification), whereas the rest is centered to the cognitive restructuring process. Therefore, MMBCBT is endowed with Behavioral Therapy (BT) and Cognitive Therapy(CT). In order to find out the validation of MMBCBT as a newly formed approach, it was then followed by mixed research (quantitative and qualitative research) with a sample selected from the elderly population following the purposive sampling technique. 40 individuals were selected from three elderly homes as per the purposive sampling technique. Elderly people identified to be depressed via Geriatric Depression Scale underwent MMBCBT for two weeks continuously while action research was being conducted simultaneously. Additionally, a Focus Group interview was carried out to support the action research. As per the research findings, people who identified depressed prior to the exposure to MMBCBT were found to be showing positive changes after they were exposed to the model. “Paired Sample t test” showed that the Multicultural Model of Buddhist based Cognitive Behavioral Therapy reduced depression of elderly people (The mean value (x̄) of the sample (level of depression) before the model was 10.7 whereas the mean value after the model was 7.5.). Most importantly, MMBCBT has been found to be effectively used with people from all walks of life despite religious diversities.

Keywords: buddhist psychotherapy, cognitive behavioral therapy in buddhism, counseling in cultural context, gerontology, and buddhism

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671 Chemopreventive Efficacy of Andrographolide in Rat Colon Carcinogenesis Model Using Aberrant Crypt Foci (ACF) as Endpoint Marker

Authors: Maryam Hajrezaie, Mahmood Ameen Abdulla, Nazia Abdul Majid, Hapipa Mohd Ali, Pouya Hassandarvish, Maryam Zahedi Fard

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Background: Colon cancer is one of the most prevalent cancers in the world and is the third leading cause of death among cancers in both males and females. The incidence of colon cancer is ranked fourth among all cancers but varies in different parts of the world. Cancer chemoprevention is defined as the use of natural or synthetic compounds capable of inducing biological mechanisms necessary to preserve genomic fidelity. Andrographolide is the major labdane diterpenoidal constituent of the plant Andrographis paniculata (family Acanthaceae), used extensively in the traditional medicine. Extracts of the plant and their constituents are reported to exhibit a wide spectrum of biological activities of therapeutic importance. Laboratory animal model studies have provided evidence that Andrographolide play a role in inhibiting the risk of certain cancers. Objective: Our aim was to evaluate the chemopreventive efficacy of the Andrographolide in the AOM induced rat model. Methods: To evaluate inhibitory properties of andrographolide on colonic aberrant crypt foci (ACF), five groups of 7-week-old male rats were used. Group 1 (control group) were fed with 10% Tween 20 once a day, Group 2 (cancer control) rats were intra-peritoneally injected with 15 mg/kg Azoxymethan, Gropu 3 (drug control) rats were injected with 15 mg/kg azoxymethan and 5-Flourouracil, Group 4 and 5 (experimental groups) were fed with 10 and 20 mg/kg andrographolide each once a day. After 1 week, the treatment group rats received subcutaneous injections of azoxymethane, 15 mg/kg body weight, once weekly for 2 weeks. Control rats were continued on Tween 20 feeding once a day and experimental groups 10 and 20 mg/kg andrographolide feeding once a day for 8 weeks. All rats were sacrificed 8 weeks after the azoxymethane treatment. Colons were evaluated grossly and histopathologically for ACF. Results: Administration of 10 mg/kg and 20 mg/kg andrographolide were found to be effectively chemoprotective, as evidenced microscopily and biochemically. Andrographolide suppressed total colonic ACF formation up to 40% to 60%, respectively, when compared with control group. Pre-treatment with andrographolide, significantly reduced the impact of AOM toxicity on plasma protein and urea levels as well as on plasma aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and gamma-glutamyl transpeptidase (GGT) activities. Grossly, colorectal specimens revealed that andrographolide treatments decreased the mean score of number of crypts in AOM-treated rats. Importantly, rats fed andrographolide showed 75% inhibition of foci containing four or more aberrant crypts. The results also showed a significant increase in glutathione (GSH), superoxide dismutase (SOD), nitric oxide (NO), and Prostaglandin E2 (PGE2) activities and a decrease in malondialdehyde (MDA) level. Histologically all treatment groups showed a significant decrease of dysplasia as compared to control group. Immunohistochemical staining showed up-regulation of Hsp70 and down-regulation of Bax proteins. Conclusion: The current study demonstrated that Andrographolide reduce the number of ACF. According to these data, Andrographolide might be a promising chemoprotective activity, in a model of AOM-induced in ACF.

Keywords: chemopreventive, andrographolide, colon cancer, aberrant crypt foci (ACF)

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670 Self-Care and Emotional Wellbeing of Nurses Using Playback Theatre and Expressive Arts

Authors: Radhika Jain

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The nursing community in India face unique challenges ranging from lack of adequate career progression, low social status attached to the profession, poor nurse-to-patient ratio leading to heavy workload resulting in stress and burnout, lack of general recognition and the responsibility of often having to deal with the ire of the patients and their families. This study explores how a combination of Playback Theatre and Expressive Arts could be used as a very powerful tool to understand the concerns, and consequently as a self-care tool to bring about the sense of well-being and emotional awareness for the nurses. For the purpose of this study, Playback Theatre was used as an entry tool to understand the thoughts, feelings and concerns. Playback theatre is a unique improvisational form of theatre developed by Jonathan Fox and Jo Salas in 1975, in which audience share their own stories from their lives and the performers play them back through a range of improv techniques such as metaphor, poetry, music and movement. Playback Theatre helped in first warming them up to the idea of sharing and then gave them the confidence of a safe space to collectively go deeper into their emotional experiences. As the next step, structured sessions of Expressive Arts were conducted with the same set of nurses, for them to work on the issues and concerns they have (and which they shared during the Playback performance). These sessions were to enable longer engagements as many of the concerns expressed were related to perceptions and beliefs that have been ingrained over a period of time and hence it needs a longer engagement to be worked on in detail. The Expressive Art sessions helped in this regard. Expressive arts therapy combines psychology and the creative process to promote emotional growth and healing. The study was conducted at two places: one a geriatric centre and the other, a palliative care centre. The study revealed that concerns and challenges would not be identical across the nursing community or across similar types of health care organizations but would be specific to each organization or centre as the circumstances and set-up at each place would be different. At the geriatric centre, stress and burnout emerged as the main concerns while at the palliative care centre, the main concern that came up was around the difficulty the nurses faced in expressing emotions and in communicating their feelings. The objective analysis of the results of the study indicated how longer-term engagements using Expressive Arts as the modality helped the nurses have better awareness of their emotions and helped them develop tools of self-care tools while also tapping into their emotions to express and experience. The process of eliciting the main concerns from the nurses using a Playback Theatre performance and then following that with subsequent sessions of expressive arts helped the nurses in the way nurses approached their job and the reduced level of overwhelm that they felt.

Keywords: palliative care, nurses, self-care, expressive arts, playback theatre

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669 Debunking Sexual Myths in Bangladesh through an Intervention on the Internet

Authors: E. Rommes, Els Toonen, Rahil Roodsaz, Suborna Camellia, Farhana Alam, Saad Khan, Jhalok Ranjon Talukder, Tanveer Hassan, Syeda Farjana Ahmed, Sabina Faiz Rashid

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In Bangladesh, a country in which adults (both parents and teachers) find it particularly hard to speak with youth about sexuality, adolescents seem to struggle with various insecurities about their sexual feelings, thoughts, behavior and physical characteristics. On the basis of a large number of interviews and focus groups with rural and urban Bangla adolescent girls and boys of lower and middle class as part of the large-scale three-year project ‘Breaking the Shame’, we have identified ten sexual themes or ‘myths’ that youth struggle with most. These encompass amongst others beliefs and insecurities on masturbation, discharge, same-sex behavior and feelings, the effects of watching porn and gender norms. We argue that the Internet is a particularly suitable medium to ‘debunk’ those myths, as youth can consult it anonymously and privately and so avoid social shame. Moreover, amongst the myths, we have identified two kinds which may need different debunking techniques. One kind of myth concerns scientifically uncontested, generally biological related information, such as the effects of having sex with a pregnant woman, questions on the effects of a penile or vaginal discharge or questions on the effects of masturbation. The second kind of myths concerns more diverse information sources and deals with e.g. religious or culturally specific norms, such as on the meaning and existence of homosexuality or gender appropriate norms of behavior in Bangladesh. For addressing both kinds of myths, expert information including a wealth of references to information resources needs to be provided, which the Internet is very suitable for. For the second kind of myths, adolescents also need to learn how to deal with sometimes conflicting norms and information sources, and they need to develop and reflect on their own opinions as part of their identity formation. On the basis of a literature review, we thus distinguish general information needs from identity formation needs, which includes the need to be able to relate information and opinions to one’s own opinions and situation. Hence, we argue that youth not only need abstract expert information to be able to debunk sexual myths, but also the option to discuss this information with other adolescents and compare their own situation and opinions with other peers, who in that way serve as ‘warm experts’ for each other. In this paper, we will describe the outcomes of our qualitative study above. In addition, we will present our findings of an intervention by presenting youth with general, uncontested information on the Internet with additional peer discussion options to compare the debunking effects on different kinds of myths.

Keywords: peer discussion, intervention, sexual myths, shame

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668 Understanding Evidence Dispersal Caused by the Effects of Using Unmanned Aerial Vehicles in Active Indoor Crime Scenes

Authors: Elizabeth Parrott, Harry Pointon, Frederic Bezombes, Heather Panter

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Unmanned aerial vehicles (UAV’s) are making a profound effect within policing, forensic and fire service procedures worldwide. These intelligent devices have already proven useful in photographing and recording large-scale outdoor and indoor sites using orthomosaic and three-dimensional (3D) modelling techniques, for the purpose of capturing and recording sites during and post-incident. UAV’s are becoming an established tool as they are extending the reach of the photographer and offering new perspectives without the expense and restrictions of deploying full-scale aircraft. 3D reconstruction quality is directly linked to the resolution of captured images; therefore, close proximity flights are required for more detailed models. As technology advances deployment of UAVs in confined spaces is becoming more common. With this in mind, this study investigates the effects of UAV operation within active crimes scenes with regard to the dispersal of particulate evidence. To date, there has been little consideration given to the potential effects of using UAV’s within active crime scenes aside from a legislation point of view. Although potentially the technology can reduce the likelihood of contamination by replacing some of the roles of investigating practitioners. There is the risk of evidence dispersal caused by the effect of the strong airflow beneath the UAV, from the downwash of the propellers. The initial results of this study are therefore presented to determine the height of least effect at which to fly, and the commercial propeller type to choose to generate the smallest amount of disturbance from the dataset tested. In this study, a range of commercially available 4-inch propellers were chosen as a starting point due to the common availability and their small size makes them well suited for operation within confined spaces. To perform the testing, a rig was configured to support a single motor and propeller powered with a standalone mains power supply and controlled via a microcontroller. This was to mimic a complete throttle cycle and control the device to ensure repeatability. By removing the variances of battery packs and complex UAV structures to allow for a more robust setup. Therefore, the only changing factors were the propeller and operating height. The results were calculated via computer vision analysis of the recorded dispersal of the sample particles placed below the arm-mounted propeller. The aim of this initial study is to give practitioners an insight into the technology to use when operating within confined spaces as well as recognizing some of the issues caused by UAV’s within active crime scenes.

Keywords: dispersal, evidence, propeller, UAV

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667 Development and Psychometric Properties of the Dutch Contextual Assessment of Social Skills: A Blinded Observational Outcome Measure of Social Skills for Adolescents with Autism Spectrum Disorder

Authors: Sakinah Idris, Femke Ten Hoeve, Kirstin Greaves-Lord

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Background: Social skills interventions are considered to be efficacious if social skills are improved as a result of an intervention. Nevertheless, the objective assessment of social skills is hindered by a lack of sensitive and validated measures. To measure the change in social skills after an intervention, questionnaires reported by parents, clinicians and/or teachers are commonly used. Observations are the most ecologically valid method of assessing improvements in social skills after an intervention. For this purpose, The Program for the Educational and Enrichment of Relational Skills (PEERS) was developed for adolescents, in order to teach them the age-appropriate skills needed to participate in society. It is an evidence-based intervention for adolescents with ASD that taught ecologically valid social skills techniques. Objectives: The current study aims to describe the development and psychometric evaluation of the Dutch Contextual Assessment of Social Skills (CASS), an observational outcome measure of social skills for adolescents with Autism Spectrum Disorder (ASD). Methods: 64 adolescents (M = 14.68, SD = 1.41, 71% boys) with ASD performed the CASS before and after a social skills intervention (i.e. PEERS or the active control condition). Each adolescent completed a 3-minute conversation with a confederate. The conversation was prompt as a natural introduction between two-unfamiliar, similar ages, opposite-sex peers who meet for the first time. The adolescent and the confederate completed a brief questionnaire about the conversation (Conversation Rating Scale). Results: Results indicated sufficient psychometric properties. The Dutch CASS has a high level of internal consistency (Cronbach's α coefficients = 0.84). Data supported the convergent validity (i.e., significant correlated with the Social Skills Improvement System (SSiS). The Dutch CASS did not significantly correlate with the autistic mannerism subscale from Social Responsiveness Scale (SRS), thus proved the divergent validity. Based on scorings made by raters who were kept blind to the time points, reliable change index was computed to assess the change in social skills. With regard to the content validity, only the learning objectives of the first two meetings of PEERS about conversational skills relatively matched with rating domains of the CASS. Due to this underrepresentation, we found an existing observational measure (TOPICC) that covers some of the other learning objectives of PEERS. TOPICC covers 22% of the learning objectives of PEERS about conversational skills, meanwhile, CASS is 45%. Unfortunately, 33% of the learning objectives of PEERS was not covered by CASS or TOPICC. Conclusion: Recommendations are made to improve the psychometric properties and content validity of the Dutch CASS.

Keywords: autism spectrum disorder, observational, PEERS, social skills

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666 Elimination of Mother to Child Transmission of HIV/AIDS: A Study of the Knowledge, Attitudes and Perceptions of Healthcare Workers in Abuja Nigeria

Authors: Ezinne K. Okoro, Takahiko Katoh, Yoko Kawamura, Stanley C. Meribe

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HIV infection in children is largely as a result of vertical transmission (mother to child transmission [MTCT]). Thus, elimination of mother to child transmission of HIV/AIDS is critical in eliminating HIV infection in children. In Nigeria, drawbacks such as; limited pediatric screening, limited human capital, insufficient advocacy and poor understanding of ART guidelines, have impacted efforts at combating the disease, even as treatment services are free. Prevention of Mother to Child Transmission (PMTCT) program relies on health workers who not only counsel pregnant women on first contact but can competently provide HIV-positive pregnant women with accurate information about the PMTCT program such as feeding techniques and drug adherence. In developing regions like Nigeria where health care delivery faces a lot of drawbacks, it becomes paramount to address these issues of poor PMTCT coverage by conducting a baseline assessment of the knowledge, practices and perceptions related to HIV prevention amongst healthcare workers in Nigeria. A descriptive cross-sectional study was conducted amongst 250 health workers currently employed in health facilities in Abuja, Nigeria where PMTCT services were offered with the capacity to carry out early infant diagnosis testing (EID). Data was collected using a self-administered, pretested, structured questionnaire. This study showed that the knowledge of PMTCT of HIV was poor (30%) among healthcare workers who offer this service day-to-day to pregnant women. When PMTCT practices were analyzed in keeping with National PMTCT guidelines, over 61% of the respondents reported observing standard practices and the majority (58%) had good attitudes towards caring for patients with HIV/AIDS. Although 61% of the respondents reported being satisfied with the quality of service being rendered, 63% reported not being satisfied with their level of knowledge. Predictors of good knowledge were job designation and level of educational attainment. Health workers who were more satisfied with their working conditions and those who had worked for a longer time in the PMTCT service were more likely to observe standard PMTCT practices. With over 62% of the healthcare workers suggesting that more training would improve the quality of service being rendered, this is a strong pointer to stakeholders to consider a ‘healthcare worker-oriented approach’ when planning and conducting PMTCT training for healthcare workers. This in turn will increase pediatric ARV coverage, the knowledge and effectiveness of the healthcare workers in carrying out appropriate PMTCT interventions and culminating in the reduction/elimination of HIV transmission to newborns.

Keywords: attitudes, HIV/AIDS, healthcare workers, knowledge, mother to child transmission, Nigeria, perceptions

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665 Applications of Polyvagal Theory for Trauma in Clinical Practice: Auricular Acupuncture and Herbology

Authors: Aurora Sheehy, Caitlin Prince

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Within current orthodox medical protocols, trauma and mental health issues are deemed to reside within the realm of cognitive or psychological therapists and are marginalised in these areas, in part due to limited drugs option available, mostly manipulating neurotransmitters or sedating patients to reduce symptoms. By contrast, this research presents examples from the clinical practice of how trauma can be assessed and treated physiologically. Adverse Childhood Experiences (ACEs) are a tally of different types of abuse and neglect. It has been used as a measurable and reliable predictor of the likelihood of the development of autoimmune disease. It is a direct way to demonstrate reliably the health impact of traumatic life experiences. A second assessment tool is Allostatic Load, which refers to the cumulative effects that chronic stress has on mental and physical health. It records the decline of an individual’s physiological capacity to cope with their experience. It uses a specific grouping of serum testing and physical measures. It includes an assessment of neuroendocrine, cardiovascular, immune and metabolic systems. Allostatic load demonstrates the health impact that trauma has throughout the body. It forms part of an initial intake assessment in clinical practice and could also be used in research to evaluate treatment. Examining medicinal plants for their physiological, neurological and somatic effects through the lens of Polyvagal theory offers new opportunities for trauma treatments. In situations where Polyvagal theory recommends activities and exercises to enable parasympathetic activation, many herbs that affect Effector Memory T (TEM) cells also enact these responses. Traditional or Indigenous European herbs show the potential to support the polyvagal tone, through multiple mechanisms. As the ventral vagal nerve reaches almost every major organ, plants that have actions on these tissues can be understood via their polyvagal actions, such as monoterpenes as agents to improve respiratory vagal tone, cyanogenic glycosides to reset polyvagal tone, volatile oils rich in phenyl methyl esters improve both sympathetic and parasympathetic tone, bitters activate gut function and can strongly promote parasympathetic regulation. Auricular Acupuncture uses a system of somatotopic mapping of the auricular surface overlaid with an image of an inverted foetus with each body organ and system featured. Given that the concha of the auricle is the only place on the body where the Vagus Nerve neurons reach the surface of the skin, several investigators have evaluated non-invasive, transcutaneous electrical nerve stimulation (TENS) at auricular points. Drawn from an interdisciplinary evidence base and developed through clinical practice, these assessment and treatment tools are examples of practitioners in the field innovating out of necessity for the best outcomes for patients. This paper draws on case studies to direct future research.

Keywords: polyvagal, auricular acupuncture, trauma, herbs

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664 Analysis of Elastic-Plastic Deformation of Reinforced Concrete Shear-Wall Structures under Earthquake Excitations

Authors: Oleg Kabantsev, Karomatullo Umarov

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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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663 New Hardy Type Inequalities of Two-Dimensional on Time Scales via Steklov Operator

Authors: Wedad Albalawi

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The mathematical inequalities have been the core of mathematical study and used in almost all branches of mathematics as well in various areas of science and engineering. The inequalities by Hardy, Littlewood and Polya were the first significant composition of several science. This work presents fundamental ideas, results and techniques, and it has had much influence on research in various branches of analysis. Since 1934, various inequalities have been produced and studied in the literature. Furthermore, some inequalities have been formulated by some operators; in 1989, weighted Hardy inequalities have been obtained for integration operators. Then, they obtained weighted estimates for Steklov operators that were used in the solution of the Cauchy problem for the wave equation. They were improved upon in 2011 to include the boundedness of integral operators from the weighted Sobolev space to the weighted Lebesgue space. Some inequalities have been demonstrated and improved using the Hardy–Steklov operator. Recently, a lot of integral inequalities have been improved by differential operators. Hardy inequality has been one of the tools that is used to consider integrity solutions of differential equations. Then, dynamic inequalities of Hardy and Coposon have been extended and improved by various integral operators. These inequalities would be interesting to apply in different fields of mathematics (functional spaces, partial differential equations, mathematical modeling). Some inequalities have been appeared involving Copson and Hardy inequalities on time scales to obtain new special version of them. A time scale is an arbitrary nonempty closed subset of the real numbers. Then, the dynamic inequalities on time scales have received a lot of attention in the literature and has become a major field in pure and applied mathematics. There are many applications of dynamic equations on time scales to quantum mechanics, electrical engineering, neural networks, heat transfer, combinatorics, and population dynamics. This study focuses on Hardy and Coposon inequalities, using Steklov operator on time scale in double integrals to obtain special cases of time-scale inequalities of Hardy and Copson on high dimensions. The advantage of this study is that it uses the one-dimensional classical Hardy inequality to obtain higher dimensional on time scale versions that will be applied in the solution of the Cauchy problem for the wave equation. In addition, the obtained inequalities have various applications involving discontinuous domains such as bug populations, phytoremediation of metals, wound healing, maximization problems. The proof can be done by introducing restriction on the operator in several cases. The concepts in time scale version such as time scales calculus will be used that allows to unify and extend many problems from the theories of differential and of difference equations. In addition, using chain rule, and some properties of multiple integrals on time scales, some theorems of Fubini and the inequality of H¨older.

Keywords: time scales, inequality of hardy, inequality of coposon, steklov operator

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662 Planning Fore Stress II: Study on Resiliency of New Architectural Patterns in Urban Scale

Authors: Amir Shouri, Fereshteh Tabe

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Master planning and urban infrastructure’s thoughtful and sequential design strategies will play the major role in reducing the damages of natural disasters, war and or social/population related conflicts for cities. Defensive strategies have been revised during the history of mankind after having damages from natural depressions, war experiences and terrorist attacks on cities. Lessons learnt from Earthquakes, from 2 world war casualties in 20th century and terrorist activities of all times. Particularly, after Hurricane Sandy of New York in 2012 and September 11th attack on New York’s World Trade Centre (WTC) in 21st century, there have been series of serious collaborations between law making authorities, urban planners and architects and defence related organizations to firstly, getting prepared and/or prevent such activities and secondly, reduce the human loss and economic damages to minimum. This study will work on developing a model of planning for New York City, where its citizens will get minimum impacts in threat-full time with minimum economic damages to the city after the stress is passed. The main discussion in this proposal will focus on pre-hazard, hazard-time and post-hazard transformative policies and strategies that will reduce the “Life casualties” and will ease “Economic Recovery” in post-hazard conditions. This proposal is going to scrutinize that one of the key solutions in this path might be focusing on all overlaying possibilities on architectural platforms of three fundamental infrastructures, the transportation, the power related sources and defensive abilities on a dynamic-transformative framework that will provide maximum safety, high level of flexibility and fastest action-reaction opportunities in stressful periods of time. “Planning Fore Stress” is going to be done in an analytical, qualitative and quantitative work frame, where it will study cases from all over the world. Technology, Organic Design, Materiality, Urban forms, city politics and sustainability will be discussed in deferent cases in international scale. From the modern strategies of Copenhagen for living friendly with nature to traditional approaches of Indonesian old urban planning patterns, the “Iron Dome” of Israel to “Tunnels” in Gaza, from “Ultra-high-performance quartz-infused concrete” of Iran to peaceful and nature-friendly strategies of Switzerland, from “Urban Geopolitics” in cities, war and terrorism to “Design of Sustainable Cities” in the world, will all be studied with references and detailed look to analysis of each case in order to propose the most resourceful, practical and realistic solutions to questions on “New City Divisions”, “New City Planning and social activities” and “New Strategic Architecture for Safe Cities”. This study is a developed version of a proposal that was announced as winner at MoMA in 2013 in call for ideas for Rockaway after Sandy Hurricane took place.

Keywords: urban scale, city safety, natural disaster, war and terrorism, city divisions, architecture for safe cities

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661 Enhanced Multi-Scale Feature Extraction Using a DCNN by Proposing Dynamic Soft Margin SoftMax for Face Emotion Detection

Authors: Armin Nabaei, M. Omair Ahmad, M. N. S. Swamy

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Many facial expression and emotion recognition methods in the traditional approaches of using LDA, PCA, and EBGM have been proposed. In recent years deep learning models have provided a unique platform addressing by automatically extracting the features for the detection of facial expression and emotions. However, deep networks require large training datasets to extract automatic features effectively. In this work, we propose an efficient emotion detection algorithm using face images when only small datasets are available for training. We design a deep network whose feature extraction capability is enhanced by utilizing several parallel modules between the input and output of the network, each focusing on the extraction of different types of coarse features with fined grained details to break the symmetry of produced information. In fact, we leverage long range dependencies, which is one of the main drawback of CNNs. We develop this work by introducing a Dynamic Soft-Margin SoftMax.The conventional SoftMax suffers from reaching to gold labels very soon, which take the model to over-fitting. Because it’s not able to determine adequately discriminant feature vectors for some variant class labels. We reduced the risk of over-fitting by using a dynamic shape of input tensor instead of static in SoftMax layer with specifying a desired Soft- Margin. In fact, it acts as a controller to how hard the model should work to push dissimilar embedding vectors apart. For the proposed Categorical Loss, by the objective of compacting the same class labels and separating different class labels in the normalized log domain.We select penalty for those predictions with high divergence from ground-truth labels.So, we shorten correct feature vectors and enlarge false prediction tensors, it means we assign more weights for those classes with conjunction to each other (namely, “hard labels to learn”). By doing this work, we constrain the model to generate more discriminate feature vectors for variant class labels. Finally, for the proposed optimizer, our focus is on solving weak convergence of Adam optimizer for a non-convex problem. Our noteworthy optimizer is working by an alternative updating gradient procedure with an exponential weighted moving average function for faster convergence and exploiting a weight decay method to help drastically reducing the learning rate near optima to reach the dominant local minimum. We demonstrate the superiority of our proposed work by surpassing the first rank of three widely used Facial Expression Recognition datasets with 93.30% on FER-2013, and 16% improvement compare to the first rank after 10 years, reaching to 90.73% on RAF-DB, and 100% k-fold average accuracy for CK+ dataset, and shown to provide a top performance to that provided by other networks, which require much larger training datasets.

Keywords: computer vision, facial expression recognition, machine learning, algorithms, depp learning, neural networks

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660 Predictive Maintenance: Machine Condition Real-Time Monitoring and Failure Prediction

Authors: Yan Zhang

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Predictive maintenance is a technique to predict when an in-service machine will fail so that maintenance can be planned in advance. Analytics-driven predictive maintenance is gaining increasing attention in many industries such as manufacturing, utilities, aerospace, etc., along with the emerging demand of Internet of Things (IoT) applications and the maturity of technologies that support Big Data storage and processing. This study aims to build an end-to-end analytics solution that includes both real-time machine condition monitoring and machine learning based predictive analytics capabilities. The goal is to showcase a general predictive maintenance solution architecture, which suggests how the data generated from field machines can be collected, transmitted, stored, and analyzed. We use a publicly available aircraft engine run-to-failure dataset to illustrate the streaming analytics component and the batch failure prediction component. We outline the contributions of this study from four aspects. First, we compare the predictive maintenance problems from the view of the traditional reliability centered maintenance field, and from the view of the IoT applications. When evolving to the IoT era, predictive maintenance has shifted its focus from ensuring reliable machine operations to improve production/maintenance efficiency via any maintenance related tasks. It covers a variety of topics, including but not limited to: failure prediction, fault forecasting, failure detection and diagnosis, and recommendation of maintenance actions after failure. Second, we review the state-of-art technologies that enable a machine/device to transmit data all the way through the Cloud for storage and advanced analytics. These technologies vary drastically mainly based on the power source and functionality of the devices. For example, a consumer machine such as an elevator uses completely different data transmission protocols comparing to the sensor units in an environmental sensor network. The former may transfer data into the Cloud via WiFi directly. The latter usually uses radio communication inherent the network, and the data is stored in a staging data node before it can be transmitted into the Cloud when necessary. Third, we illustrate show to formulate a machine learning problem to predict machine fault/failures. By showing a step-by-step process of data labeling, feature engineering, model construction and evaluation, we share following experiences: (1) what are the specific data quality issues that have crucial impact on predictive maintenance use cases; (2) how to train and evaluate a model when training data contains inter-dependent records. Four, we review the tools available to build such a data pipeline that digests the data and produce insights. We show the tools we use including data injection, streaming data processing, machine learning model training, and the tool that coordinates/schedules different jobs. In addition, we show the visualization tool that creates rich data visualizations for both real-time insights and prediction results. To conclude, there are two key takeaways from this study. (1) It summarizes the landscape and challenges of predictive maintenance applications. (2) It takes an example in aerospace with publicly available data to illustrate each component in the proposed data pipeline and showcases how the solution can be deployed as a live demo.

Keywords: Internet of Things, machine learning, predictive maintenance, streaming data

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659 Electric Vehicle Fleet Operators in the Energy Market - Feasibility and Effects on the Electricity Grid

Authors: Benjamin Blat Belmonte, Stephan Rinderknecht

Abstract:

The transition to electric vehicles (EVs) stands at the forefront of innovative strategies designed to address environmental concerns and reduce fossil fuel dependency. As the number of EVs on the roads increases, so too does the potential for their integration into energy markets. This research dives deep into the transformative possibilities of using electric vehicle fleets, specifically electric bus fleets, not just as consumers but as active participants in the energy market. This paper investigates the feasibility and grid effects of electric vehicle fleet operators in the energy market. Our objective centers around a comprehensive exploration of the sector coupling domain, with an emphasis on the economic potential in both electricity and balancing markets. Methodologically, our approach combines data mining techniques with thorough pre-processing, pulling from a rich repository of electricity and balancing market data. Our findings are grounded in the actual operational realities of the bus fleet operator in Darmstadt, Germany. We employ a Mixed Integer Linear Programming (MILP) approach, with the bulk of the computations being processed on the High-Performance Computing (HPC) platform ‘Lichtenbergcluster’. Our findings underscore the compelling economic potential of EV fleets in the energy market. With electric buses becoming more prevalent, the considerable size of these fleets, paired with their substantial battery capacity, opens up new horizons for energy market participation. Notably, our research reveals that economic viability is not the sole advantage. Participating actively in the energy market also translates into pronounced positive effects on grid stabilization. Essentially, EV fleet operators can serve a dual purpose: facilitating transport while simultaneously playing an instrumental role in enhancing grid reliability and resilience. This research highlights the symbiotic relationship between the growth of EV fleets and the stabilization of the energy grid. Such systems could lead to both commercial and ecological advantages, reinforcing the value of electric bus fleets in the broader landscape of sustainable energy solutions. In conclusion, the electrification of transport offers more than just a means to reduce local greenhouse gas emissions. By positioning electric vehicle fleet operators as active participants in the energy market, there lies a powerful opportunity to drive forward the energy transition. This study serves as a testament to the synergistic potential of EV fleets in bolstering both economic viability and grid stabilization, signaling a promising trajectory for future sector coupling endeavors.

Keywords: electric vehicle fleet, sector coupling, optimization, electricity market, balancing market

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658 Assessment of N₂ Fixation and Water-Use Efficiency in a Soybean-Sorghum Rotation System

Authors: Mmatladi D. Mnguni, Mustapha Mohammed, George Y. Mahama, Alhassan L. Abdulai, Felix D. Dakora

Abstract:

Industrial-based nitrogen (N) fertilizers are justifiably credited for the current state of food production across the globe, but their continued use is not sustainable and has an adverse effect on the environment. The search for greener and sustainable technologies has led to an increase in exploiting biological systems such as legumes and organic amendments for plant growth promotion in cropping systems. Although the benefits of legume rotation with cereal crops have been documented, the full benefits of soybean-sorghum rotation systems have not been properly evaluated in Africa. This study explored the benefits of soybean-sorghum rotation through assessing N₂ fixation and water-use efficiency of soybean in rotation with sorghum with and without organic and inorganic amendments. The field trials were conducted from 2017 to 2020. Sorghum was grown on plots previously cultivated to soybean and vice versa. The succeeding sorghum crop received fertilizer amendments [organic fertilizer (5 tons/ha as poultry litter, OF); inorganic fertilizer (80N-60P-60K) IF; organic + inorganic fertilizer (OF+IF); half organic + inorganic fertilizer (HIF+OF); organic + half inorganic fertilizer (OF+HIF); half organic + half inorganic (HOF+HIF) and control] and was arranged in a randomized complete block design. The soybean crop succeeding fertilized sorghum received a blanket application of triple superphosphate at 26 kg P ha⁻¹. Nitrogen fixation and water-use efficiency were respectively assessed at the flowering stage using the ¹⁵N and ¹³C natural abundance techniques. The results showed that the shoot dry matter of soybean plants supplied with HOF+HIF was much higher (43.20 g plant-1), followed by OF+HIF (36.45 g plant⁻¹), and HOF+IF (33.50 g plant⁻¹). Shoot N concentration ranged from 1.60 to 1.66%, and total N content from 339 to 691 mg N plant⁻¹. The δ¹⁵N values of soybean shoots ranged from -1.17‰ to -0.64‰, with plants growing on plots previously treated to HOF+HIF exhibiting much higher δ¹⁵N values, and hence lower percent N derived from N₂ fixation (%Ndfa). Shoot %Ndfa values varied from 70 to 82%. The high %Ndfa values obtained in this study suggest that the previous year’s organic and inorganic fertilizer amendments to sorghum did not inhibit N₂ fixation in the following soybean crop. The amount of N-fixed by soybean ranged from 106 to 197 kg N ha⁻¹. The treatments showed marked variations in carbon (C) content, with HOF+HIF treatment recording the highest C content. Although water-use efficiency varied from -29.32‰ to -27.85‰, shoot water-use efficiency, C concentration, and C:N ratio were not altered by previous fertilizer application to sorghum. This study provides strong evidence that previous HOF+HIF sorghum residues can enhance N nutrition and water-use efficiency in nodulated soybean.

Keywords: ¹³C and ¹⁵N natural abundance, N-fixed, organic and inorganic fertilizer amendments, shoot %Ndfa

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657 Complementing Assessment Processes with Standardized Tests: A Work in Progress

Authors: Amparo Camacho

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ABET accredited programs must assess the development of student learning outcomes (SOs) in engineering programs. Different institutions implement different strategies for this assessment, and they are usually designed “in house.” This paper presents a proposal for including standardized tests to complement the ABET assessment model in an engineering college made up of six distinct engineering programs. The engineering college formulated a model of quality assurance in education to be implemented throughout the six engineering programs to regularly assess and evaluate the achievement of SOs in each program offered. The model uses diverse techniques and sources of data to assess student performance and to implement actions of improvement based on the results of this assessment. The model is called “Assessment Process Model” and it includes SOs A through K, as defined by ABET. SOs can be divided into two categories: “hard skills” and “professional skills” (soft skills). The first includes abilities, such as: applying knowledge of mathematics, science, and engineering and designing and conducting experiments, as well as analyzing and interpreting data. The second category, “professional skills”, includes communicating effectively, and understanding professional and ethnical responsibility. Within the Assessment Process Model, various tools were used to assess SOs, related to both “hard” as well as “soft” skills. The assessment tools designed included: rubrics, surveys, questionnaires, and portfolios. In addition to these instruments, the Engineering College decided to use tools that systematically gather consistent quantitative data. For this reason, an in-house exam was designed and implemented, based on the curriculum of each program. Even though this exam was administered during various academic periods, it is not currently considered standardized. In 2017, the Engineering College included three standardized tests: one to assess mathematical and scientific reasoning and two more to assess reading and writing abilities. With these exams, the college hopes to obtain complementary information that can help better measure the development of both hard and soft skills of students in the different engineering programs. In the first semester of 2017, the three exams were given to three sample groups of students from the six different engineering programs. Students in the sample groups were either from the first, fifth, and tenth semester cohorts. At the time of submission of this paper, the engineering college has descriptive statistical data and is working with various statisticians to have a more in-depth and detailed analysis of the sample group of students’ achievement on the three exams. The overall objective of including standardized exams in the assessment model is to identify more precisely the least developed SOs in order to define and implement educational strategies necessary for students to achieve them in each engineering program.

Keywords: assessment, hard skills, soft skills, standardized tests

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656 Oxalate Method for Assessing the Electrochemical Surface Area for Ni-Based Nanoelectrodes Used in Formaldehyde Sensing Applications

Authors: S. Trafela, X. Xua, K. Zuzek Rozmana

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In this study, we used an accurate and precise method to measure the electrochemically active surface areas (Aecsa) of nickel electrodes. Calculated Aecsa is really important for the evaluation of an electro-catalyst’s activity in electrochemical reaction of different organic compounds. The method involves the electrochemical formation of Ni(OH)₂ and NiOOH in the presence of adsorbed oxalate in alkaline media. The studies were carried out using cyclic voltammetry with polycrystalline nickel as a reference material and electrodeposited nickel nanowires, homogeneous and heterogeneous nickel films. From cyclic voltammograms, the charge (Q) values for the formation of Ni(OH)₂ and NiOOH surface oxides were calculated under various conditions. At sufficiently fast potential scan rates (200 mV s⁻¹), the adsorbed oxalate limits the growth of the surface hydroxides to a monolayer. Although the Ni(OH)₂/NiOOH oxidation peak overlaps with the oxygen evolution reaction, in the reverse scan, the NiOOH/ Ni(OH)₂ reduction peak is well-separated from other electrochemical processes and can be easily integrated. The values of these integrals were used to correlate experimentally measured charge density with an electrochemically active surface layer. The Aecsa of the nickel nanowires, homogeneous and heterogeneous nickel films were calculated to be Aecsa-NiNWs = 4.2066 ± 0.0472 cm², Aecsa-homNi = 1.7175 ± 0.0503 cm² and Aecsa-hetNi = 2.1862 ± 0.0154 cm². These valuable results were expanded and used in electrochemical studies of formaldehyde oxidation. As mentioned nickel nanowires, heterogeneous and homogeneous nickel films were used as simple and efficient sensor for formaldehyde detection. For this purpose, electrodeposited nickel electrodes were modified in 0.1 mol L⁻¹ solution of KOH in order to expect electrochemical activity towards formaldehyde. The investigation of the electrochemical behavior of formaldehyde oxidation in 0.1 mol L⁻¹ NaOH solution at the surface of modified nickel nanowires, homogeneous and heterogeneous nickel films were carried out by means of electrochemical techniques such as cyclic voltammetric and chronoamperometric methods. From investigations of effect of different formaldehyde concentrations (from 0.001 to 0.1 mol L⁻¹) on electrochemical signal - current we provided catalysis mechanism of formaldehyde oxidation, detection limit and sensitivity of nickel electrodes. The results indicated that nickel electrodes participate directly in the electrocatalytic oxidation of formaldehyde. In the overall reaction, formaldehyde in alkaline aqueous solution exists predominantly in form of CH₂(OH)O⁻, which is oxidized to CH₂(O)O⁻. Taking into account the determined (Aecsa) values we have been able to calculate the sensitivities: 7 mA mol L⁻¹ cm⁻² for nickel nanowires, 3.5 mA mol L⁻¹ cm⁻² for heterogeneous nickel film and 2 mA mol L⁻¹ cm⁻² for heterogeneous nickel film. The detection limit was 0.2 mM for nickel nanowires, 0.5 mM for porous Ni film and 0.8 mM for homogeneous Ni film. All of these results make nickel electrodes capable for further applications.

Keywords: electrochemically active surface areas, nickel electrodes, formaldehyde, electrocatalytic oxidation

Procedia PDF Downloads 162