Search results for: alternative family structures
7798 Flexural Performance of the Sandwich Structures Having Aluminum Foam Core with Different Thicknesses
Authors: Emre Kara, Ahmet Fatih Geylan, Kadir Koç, Şura Karakuzu, Metehan Demir, Halil Aykul
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The structures obtained with the use of sandwich technologies combine low weight with high energy absorbing capacity and load carrying capacity. Hence, there is a growing and markedly interest in the use of sandwiches with aluminium foam core because of very good properties such as flexural rigidity and energy absorption capability. The static (bending and penetration) and dynamic (dynamic bending and low velocity impact) tests were already performed on the aluminum foam cored sandwiches with different types of outer skins by some of the authors. In the current investigation, the static three-point bending tests were carried out on the sandwiches with aluminum foam core and glass fiber reinforced polymer (GFRP) skins at different values of support span distances (L= 55, 70, 80, 125 mm) aiming the analyses of their flexural performance. The influence of the core thickness and the GFRP skin type was reported in terms of peak load, energy absorption capacity and energy efficiency. For this purpose, the skins with two different types of fabrics ([0°/90°] cross ply E-Glass Woven and [0°/90°] cross ply S-Glass Woven which have same thickness value of 1.5 mm) and the aluminum foam core with two different thicknesses (h=10 and 15 mm) were bonded with a commercial polyurethane based flexible adhesive in order to combine the composite sandwich panels. The GFRP skins fabricated via Vacuum Assisted Resin Transfer Molding (VARTM) technique used in the study can be easily bonded to the aluminum foam core and it is possible to configure the base materials (skin, adhesive and core), fiber angle orientation and number of layers for a specific application. The main results of the bending tests are: force-displacement curves, peak force values, absorbed energy, energy efficiency, collapse mechanisms and the effect of the support span length and core thickness. The results of the experimental study showed that the sandwich with the skins made of S-Glass Woven fabrics and with the thicker foam core presented higher mechanical values such as load carrying and energy absorption capacities. The increment of the support span distance generated the decrease of the mechanical values for each type of panels, as expected, because of the inverse proportion between the force and span length. The most common failure types of the sandwiches are debonding of the upper or lower skin and the core shear. The obtained results have particular importance for applications that require lightweight structures with a high capacity of energy dissipation, such as the transport industry (automotive, aerospace, shipbuilding and marine industry), where the problems of collision and crash have increased in the last years.Keywords: aluminum foam, composite panel, flexure, transport application
Procedia PDF Downloads 3407797 Re-Framing Resilience Turn in Risk and Management with Anti-Positivistic Perspective of Holling's Early Work
Authors: Jose CanIzares
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In the last decades, resilience has received much attention in relation to understanding and managing new forms of risk, especially in the context of urban adaptation to climate change. There are abundant concerns, however, on how to best interpret resilience and related ideas, and on whether they can guide ethically appropriate risk-related or adaptation efforts. Narrative creation and framing are critical steps in shaping public discussion and policy in large-scale interventions, since they favor or inhibit early decision and interpretation habits, which can be morally sensitive and then become persistent on time. This article adds to such framing process by contesting a conventional narrative on resilience and offering an alternative one. Conventionally, present ideas on resilience are traced to the work of ecologist C. S. Holling, especially to his article Resilience and Stability in Ecosystems. This article is usually portrayed as a contribution of complex systems thinking to theoretical ecology, where Holling appeals to resilience in order to challenge received views on ecosystem stability and the diversity-stability hypothesis. In this regard, resilience is construed as a “purely scientific”, precise and descriptive concept, denoting a complex property that allows ecosystems to persist, or to maintain functions, after disturbance. Yet, these formal features of resilience supposedly changed with Holling’s later work in the 90s, where, it is argued, Holling begun to use resilience as a more pragmatic “boundary term”, aimed at unifying transdisciplinary research about risks, ecological or otherwise, and at articulating public debate and governance strategies on the issue. In the conventional story, increased vagueness and degrees of normativity are the price to pay for this conceptual shift, which has made the term more widely usable, but also incompatible with scientific purposes and morally problematic (if not completely objectionable). This paper builds on a detailed analysis of Holling’s early work to propose an alternative narrative. The study will show that the “complexity turn” has often entangled theoretical and pragmatic aims. Accordingly, Holling’s primary aim was to fight what he termed “pathologies of natural resource management” or “pathologies of command and control management”, and so, the terms of his reform of ecosystem science are partly subordinate to the details of his proposal for reforming the management sciences. As regards resilience, Holling used it as a polysemous, ambiguous and normative term: sometimes, as an instrumental value that is closely related to various stability concepts; other times, and more crucially, as an intrinsic value and a tool for attacking efficiency and instrumentalism in management. This narrative reveals the limitations of its conventional alternative and has several practical advantages. It captures well the structure and purposes of Holling’s project, and the various roles of resilience in it. It helps to link Holling’s early work with other philosophical and ideological shifts at work in the 70s. It highlights the currency of Holling’s early work for present research and action in fields such as risk and climate adaptation. And it draws attention to morally relevant aspects of resilience that the conventional narrative neglects.Keywords: resilience, complexity turn, risk management, positivistic, framing
Procedia PDF Downloads 1667796 Catalytic Pyrolysis of Sewage Sludge for Upgrading Bio-Oil Quality Using Sludge-Based Activated Char as an Alternative to HZSM5
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Due to the concerns about the depletion of fossil fuel sources and the deteriorating environment, the attempt to investigate the production of renewable energy will play a crucial role as a potential to alleviate the dependency on mineral fuels. In this respect, biofuels are measured as a vital nominee for national energy security and energy sustainability. Sewage sludge (SS), as an alternative source of renewable energy with a complex composition, is a major waste generated during wastewater treatment. Stricter legislation is continuously refining the requirements for the level of removal of various pollutants in treated water, causing continuous growth of sludge production, which has become a global challenge. In general, there are two main procedures for dealing with SS: incineration and landfill. However, there are a variety of limitations in these options (e.g., production of greenhouse gases and restrictive environmental regulations) in regard to negative social and economic impacts. Pyrolysis is a feasible and cost-effective technology that can simultaneously tackle boundaries concerning the current disposal routes while retrieving bioenergy. Pyrolysis of SS has drawn vigorous interest in research due to the ability of high mass yield of pyrolytic liquid production. Nonetheless, the presence of high molecular weight hydrocarbons and oxygenated- and nitrogenated compounds poses a considerable challenge. In this context, catalytic pyrolysis is another attainable route in order to upgrade the bio-oil quality. Among different catalysts (i.e., zeolites) studied for sewage sludge pyrolysis, activated chars are eco-friendly and low-cost alternatives. The beneficial features comprise comparatively large surface area, long-term stability, and enriched surface functional groups. In light of these premises, this research attempts to investigate the catalytic pyrolysis of sewage sludge with a high-performance sludge-based activated char in contrast to HZSM5 from a theoretical and experimental point of view.Keywords: catalytic pyrolysis, sewage sludge, char, HZSM5, bio-oil.
Procedia PDF Downloads 527795 Paramecuim as a Model for the Evaluation of Toxicity (Growth, Total Proteins, Respiratory and GSH Bio Marker Changes) Observed after Treatment with Essential Oils Isolated from Artemisia herba-alba Plant of Algeria
Authors: Bouchiha Hanene, Rouabhi Rachid, Bouchama Khaled, Djebar Berrebbah Houraya, Djebar Mohamed Reda
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Recently, some natural products such as essentials oils (EOs) have been used in the fields as alternative to synthetic compounds, to minimize the negative impacts to the environment. This fact has led to questions about the possible impact of EOs on ecosystems. Currently in toxicology, the use of alternative models can help to understand the mechanisms of toxic action, at different levels of organization of ecosystems. Algae, protozoa and bacteria form the base of the food chain and protozoan cells are used as bioindicators often of pollution in environment. Unicellular organisms offer the possibility of direct study of independent cells with specific characteristics of individual cells and whole organisms at the same time. This unicellular facilitates the study of physiological processes, and effects of pollutants at the cellular level, which makes it widely used to assess the toxic effects of various xenobiotics. This study aimed to verify the effects of EOs of one famous plant used tremendously in our folk medicine, namely Artemisia herba alba in causing acute toxicity (24 hours) and chronic (15 days) toxicity for model cellular (Paramecium sp). To this end, cellular’s of paramecium were exposed to various concentrations (Three doses were chosen) of EOs extracted from plant (Artemisia herba alba). In the first experiment, the cellular s cultures were exposed for 48 hours to different concentrations to determine the median lethal concentration (DL50). We followed the evolution of physiological parameters (growth), biochemical (total proteins, respiratory metabolism), as well as the variations of a bio marker the GSH. Our results highlighted a light inhibition of the growth of the protozoa as well as a disturbance of the contents of total proteins and a reduction in the reduced rate of glutathione. The polarographic study revealed a stimulation of the consumption of O2 and this at the treated cells.Keywords: essential oils, protozoa, bio indicators, toxicity, Growth, bio marker, proteins, polarographic
Procedia PDF Downloads 3477794 Visual Impairment Through Contextualized Lived Experiences: The Story of James
Authors: Jentel Van Havermaet, Geert Van Hove, Elisabeth De Schauwer
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This study re-conceptualizes visual impairment in the interdependent context of James, his family, and allies. Living with a visual impairment is understood as an entanglement of assemblages, dynamics, disablism, systems… We narrated this diffractively into two meaningful events: decisions and processes on (inclusive) education and hinderances in connecting with others. We entangled and (un)raveled lived experiences in assemblages in which the contextualized meaning of visual impairment became more clearly. The contextualized narrative of James interwove complex intra-actions; showed the complexity and contextualization of entangled relationalities.Keywords: disability studies, contextualization, visual impairment, assemblage, entanglement, lived experiences
Procedia PDF Downloads 1817793 Burnout and Personality Characteristics of University Students
Authors: Tazvin Ijaz, Rabia Khan
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The current study was conducted to identify the predictors of burnout among university students. The sample for the study was collected through simple random sampling. The tools to measure burnout and personality characteristics included Indigenous burnout scale and Eysenck personality inventory respectively. Results indicated that neurotic personality traits significantly predicts burnout among university students while extraversion does not lead to burnout. Results also indicated female students experience more burnout than male students. It was also found that family size and birth order did not affected the level of burnout. Results of the study are discussed to explain association between etiological factors and burnout with in Pakistani cultural context.Keywords: burnout, students, neuroticism, extraversion
Procedia PDF Downloads 2987792 Development of Bicomponent Fibre to Combat Insects
Authors: M. Bischoff, F. Schmidt, J. Herrmann, J. Mattheß, G. Seide, T. Gries
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Crop yields have not increased as dramatically as the demand for food. One method to counteract this is to use pesticides to keep away predators, e.g. several forms of insecticide are available to fight insects. These insecticides and pesticides are both controversial as their application and their residue in the food product can also harm humans. In this study an alternative method to combat insects is studied. A physical insect-killing effect of SiO2 particles is used. The particles are applied on fibres to avoid erosion in the fields, which would occur when applied separately. The development of such SiO2 functionalized PP fibres is shown.Keywords: agriculture, environment, insects, protection, silica, textile
Procedia PDF Downloads 3017791 Muslims in Diaspora Negotiating Islam through Muslim Public Sphere and the Role of Media
Authors: Sabah Khan
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The idea of universal Islam tends to exaggerate the extent of homogeneity in Islamic beliefs and practices across Muslim communities. In the age of migration, various Muslim communities are in diaspora. The immediate implication of this is what happens to Islam in diaspora? How Islam gets represented in new forms? Such pertinent questions need to be dealt with. This paper shall draw on the idea of religious transnationalism, primarily transnational Islam. There are multiple ways to conceptualize transnational phenomenon with reference to Islam in terms of flow of people, transnational organizations and networks; Ummah oriented solidarity and the new Muslim public sphere. This paper specifically deals with the new Muslim public sphere. It primarily refers to the space and networks enabled by new media and communication technologies, whereby Muslim identity and Islamic normativity are rehearsed, debated by people in different locales. A new sense of public is emerging across Muslim communities, which needs to be contextualized. This paper uses both primary and secondary data. Primary data elicited through content analysis of audio-visuals on social media and secondary sources of information ranging from books, articles, journals, etc. The basic aim of the paper is to focus on the emerging Muslim public sphere and the role of media in expanding public spheres of Islam. It also explores how Muslims in diaspora negotiate Islam and Islamic practices through media and the new Muslim public sphere. This paper cogently weaves in discussions firstly, of re-intellectualization of Islamic discourse in the public sphere. In other words, how Muslims have come to reimagine their collective identity and critically look at fundamental principles and authoritative tradition. Secondly, the emerging alternative forms of Islam by young Muslims in diaspora. In other words, how young Muslims search for unorthodox ways and media for religious articulation, including music, clothing and TV. This includes transmission and distribution of Islam in diaspora in terms of emerging ‘media Islam’ or ‘soundbite Islam’. The new Muslim public sphere has offered an arena to a large number of participants to critically engage with Islam, which leads not only to a critical engagement with traditional forms of Islamic authority but also emerging alternative forms of Islam and Islamic practices.Keywords: Islam, media, Muslims, public sphere
Procedia PDF Downloads 2717790 The Relationship between Caregiver Burden and Life Satisfaction of Caregivers of Elderly Individuals
Authors: Guler Duru Asiret, Cemile Kutmec Yilmaz, Gulcan Bagcivan, Tugce Turten Kaymaz
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This descriptive study was conducted to determine the relationship between caregiver burden and life satisfaction who give home care to elderly individuals. The sample was recruited from the internal medicine unit and palliative unit of a state hospital located in Turkey on June 2016-2017. The study sample consisted of 231 primary caregiver family member, who met the eligibility criteria and agreed to participate in the study. The inclusion criteria were as follows: inpatient’s caregiver, primary caregiver for at least 3 months, at least 18 years of age, no communication problem or mental disorder. Data were gathered using an Information Form prepared by the researchers based on previous literature, the Zarit Burden Interview (ZBI), and the Satisfaction with Life Scale (SWLS). The data were analyzed using IBM SPSS Statistics software version 20.0 (SPSS, Chicago, IL). The descriptive characteristics of the participant were analyzed using number, percentage, mean and standard deviation. The suitability of normal distribution of scale scores was analyzed using Kolmogorov-Smirnov and Shapiro-Wilk test. Relationships between scales were analyzed using Spearman’s rank-correlation coefficient. P values less than 0.05 were considered to be significant. The average age of the caregivers was 50.11±13.46 (mean±SD) years. Of the caregivers, 76.2% were women, 45% were primary school graduates, 89.2% were married, 38.1% were the daughters of their patients. Among these, 52.4% evaluated their income level to be good. Of them, 53.6% had been giving care less than 2 years. The patients’ average age was 77.1±8.0 years. Of the patients, 55.8% were women, 56.3% were illeterate, 70.6% were married, and 97.4% had at least one chronic disease. The mean Zarit Burden Interview score was 35.4±1.5 and the Satisfaction with Life Scale score was 20.6±6.8. A negative relationship was found between the patients’ score average on the ZBI, and on the SWLS (r= -0.438, p=0.000). The present study determined that the caregivers have a moderate caregiver burden and the life satisfaction. And the life satisfaction of caregivers decreased as their caregiver burden increase. In line with the results obtained from the research, it is recommended that to increase the effectiveness of discharge training, to arrange training and counseling programs for caregivers to cope with the problems they experienced, to monitor the caregivers at regular intervals and to provide necessary institutional support.Keywords: caregiver burden, family caregivers, nurses, satisfaction
Procedia PDF Downloads 1767789 Numerical Solutions of Generalized Burger-Fisher Equation by Modified Variational Iteration Method
Authors: M. O. Olayiwola
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Numerical solutions of the generalized Burger-Fisher are obtained using a Modified Variational Iteration Method (MVIM) with minimal computational efforts. The computed results with this technique have been compared with other results. The present method is seen to be a very reliable alternative method to some existing techniques for such nonlinear problems.Keywords: burger-fisher, modified variational iteration method, lagrange multiplier, Taylor’s series, partial differential equation
Procedia PDF Downloads 4327788 Loading Methodology for a Capacity Constrained Job-Shop
Authors: Viraj Tyagi, Ajai Jain, P. K. Jain, Aarushi Jain
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This paper presents a genetic algorithm based loading methodology for a capacity constrained job-shop with the consideration of alternative process plans for each part to be produced. Performance analysis of the proposed methodology is carried out for two case studies by considering two different manufacturing scenarios. Results obtained indicate that the methodology is quite effective in improving the shop load balance, and hence, it can be included in the frameworks of manufacturing planning systems of job-shop oriented industries.Keywords: manufacturing planning, loading, genetic algorithm, job shop
Procedia PDF Downloads 3037787 Microfluidic Chambers with Fluid Walls for Cell Biology
Authors: Cristian Soitu, Alexander Feuerborn, Cyril Deroy, Alfonso Castrejon-Pita, Peter R. Cook, Edmond J. Walsh
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Microfluidics now stands as an academically mature technology after a quarter of a century research activities have delivered a vast array of proof of concepts for many biological workflows. However, translation to industry remains poor, with only a handful of notable exceptions – e.g. digital PCR, DNA sequencing – mainly because of biocompatibility issues, limited range of readouts supported or complex operation required. This technology exploits the domination of interfacial forces over gravitational ones at the microscale, replacing solid walls with fluid ones as building blocks for cell micro-environments. By employing only materials used by biologists for decades, the system is shown to be biocompatible, and easy to manufacture and operate. The method consists in displacing a continuous fluid layer into a pattern of isolated chambers overlaid with an immiscible liquid to prevent evaporation. The resulting fluid arrangements can be arrays of micro-chambers with rectangular footprint, which use the maximum surface area available, or structures with irregular patterns. Pliant, self-healing fluid walls confine volumes as small as 1 nl. Such fluidic structures can be reconfigured during the assays, giving the platform an unprecedented level of flexibility. Common workflows in cell biology are demonstrated – e.g. cell growth and retrieval, cloning, cryopreservation, fixation and immunolabeling, CRISPR-Cas9 gene editing, and proof-of-concept drug tests. This fluid-shaping technology is shown to have potential for high-throughput cell- and organism-based assays. The ability to make and reconfigure on-demand microfluidic circuits on standard Petri dishes should find many applications in biology, and yield more relevant phenotypic and genotypic responses when compared to standard microfluidic assays.Keywords: fluid walls, micro-chambers, reconfigurable, freestyle
Procedia PDF Downloads 1947786 A Review on Investigating the Relations between Water Harvesting and Water Conflicts
Authors: B. Laurita
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The importance of Water Harvesting (WH) as an effective mean to deal with water scarcity is universally recognized. The collection and storage of rainwater, floodwater or quick runoff and their conversion to productive uses can ensure water availability for domestic and agricultural use, enabling a lower exploitation of the aquifer, preventing erosion events and providing significant ecosystem services. At the same time, it has been proven that it can reduce the insurgence of water conflicts if supported by a cooperative process of planning and management. On the other hand, the construction of water harvesting structures changes the hydrological regime, affecting upstream-downstream dynamics and changing water allocation, often causing contentions. Furthermore, dynamics existing between water harvesting and water conflict are not properly investigated yet. Thus, objective of this study is to analyze the relations between water harvesting and the insurgence of water conflicts, providing a solid theoretical basis and foundations for future studies. Two search engines were selected in order to perform the study: Google Scholar and Scopus. Separate researches were conducted on the mutual influences between water conflicts and the four main water harvesting techniques: rooftop harvesting, surface harvesting, underground harvesting, runoff harvesting. Some of the aforementioned water harvesting techniques have been developed and implemented on scales ranging from the small, household-sided ones, to gargantuan dam systems. Instead of focusing on the collisions related to large-scale systems, this review is aimed to look for and collect examples of the effects that the implementation of small water harvesting systems has had on the access to the water resource and on water governance. The present research allowed to highlight that in the studies that have been conducted up to now, water harvesting, and in particular those structures that allow the collection and storage of water for domestic use, is usually recognized as a positive, palliative element during contentions. On the other hand, water harvesting can worsen and, in some cases, even generate conflicts for water management. This shows the necessity of studies that consider both benefits and negative influences of water harvesting, analyzing its role respectively as triggering or as mitigating factor of conflicting situations.Keywords: arid areas, governance, water conflicts, water harvesting
Procedia PDF Downloads 2047785 Vertical Village Buildings as Sustainable Strategy to Re-Attract Mega-Cities in Developing Countries
Authors: M. J. Eichner, Y. S. Sarhan
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Overall study purpose has been the evaluation of ‘Vertical Villages’ as a new sustainable building typology, reducing significantly negative impacts of rapid urbanization processes in third world capital cities. Commonly in fast-growing cities, housing and job supply, educational and recreational opportunities, as well as public transportation infrastructure, are not accommodating rapid population growth, exposing people to high noise and emission polluted living environments with low-quality neighborhoods and a lack of recreational areas. Like many others, Egypt’s capital city Cairo, according to the UN facing annual population growth rates of up to 428.000 people, is struggling to address the general deterioration of urban living conditions. New settlements typologies and urban reconstruction approach hardly follow sustainable urbanization principles or socio-ecologic urbanization models with severe effects not only for inhabitants but also for the local environment and global climate. The authors prove that ‘Vertical Village’ buildings can offer a sustainable solution for increasing urban density with at the same time improving the living quality and urban environment significantly. Inserting them within high-density urban fabrics the ecologic and socio-cultural conditions of low-quality neighborhoods can be transformed towards districts, considering all needs of sustainable and social urban life. This study analyzes existing building typologies in Cairo’s «low quality - high density» districts Ard el Lewa, Dokki and Mohandesen according to benchmarks for sustainable residential buildings, identifying major problems and deficits. In 3 case study design projects, the sustainable transformation potential through ‘Vertical Village’ buildings are laid out and comparative studies show the improvement of the urban microclimate, safety, social diversity, sense of community, aesthetics, privacy, efficiency, healthiness and accessibility. The main result of the paper is that the disadvantages of density and overpopulation in developing countries can be converted with ‘Vertical Village’ buildings into advantages, achieving attractive and environmentally friendly living environments with multiple synergies. The paper is documenting based on scientific criteria that mixed-use vertical building structures, designed according to sustainable principles of low rise housing, can serve as an alternative to convert «low quality - high density» districts in megacities, opening a pathway for governments to achieve sustainable urban transformation goals. Neglected informal urban districts, home to millions of the poorer population groups, can be converted into healthier living and working environments.Keywords: sustainable, architecture, urbanization, urban transformation, vertical village
Procedia PDF Downloads 1267784 A Geometrical Perspective on the Insulin Evolution
Authors: Yuhei Kunihiro, Sorin V. Sabau, Kazuhiro Shibuya
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We study the molecular evolution of insulin from the metric geometry point of view. In mathematics, and particularly in geometry, distances and metrics between objects are of fundamental importance. Using a weaker notion than the classical distance, namely the weighted quasi-metrics, one can study the geometry of biological sequences (DNA, mRNA, or proteins) space. We analyze from the geometrical point of view a family of 60 insulin homologous sequences ranging on a large variety of living organisms from human to the nematode C. elegans. We show that the distances between sequences provide important information about the evolution and function of insulin.Keywords: metric geometry, evolution, insulin, C. elegans
Procedia PDF Downloads 3407783 Validation of Asymptotic Techniques to Predict Bistatic Radar Cross Section
Authors: M. Pienaar, J. W. Odendaal, J. C. Smit, J. Joubert
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Simulations are commonly used to predict the bistatic radar cross section (RCS) of military targets since characterization measurements can be expensive and time consuming. It is thus important to accurately predict the bistatic RCS of targets. Computational electromagnetic (CEM) methods can be used for bistatic RCS prediction. CEM methods are divided into full-wave and asymptotic methods. Full-wave methods are numerical approximations to the exact solution of Maxwell’s equations. These methods are very accurate but are computationally very intensive and time consuming. Asymptotic techniques make simplifying assumptions in solving Maxwell's equations and are thus less accurate but require less computational resources and time. Asymptotic techniques can thus be very valuable for the prediction of bistatic RCS of electrically large targets, due to the decreased computational requirements. This study extends previous work by validating the accuracy of asymptotic techniques to predict bistatic RCS through comparison with full-wave simulations as well as measurements. Validation is done with canonical structures as well as complex realistic aircraft models instead of only looking at a complex slicy structure. The slicy structure is a combination of canonical structures, including cylinders, corner reflectors and cubes. Validation is done over large bistatic angles and at different polarizations. Bistatic RCS measurements were conducted in a compact range, at the University of Pretoria, South Africa. The measurements were performed at different polarizations from 2 GHz to 6 GHz. Fixed bistatic angles of β = 30.8°, 45° and 90° were used. The measurements were calibrated with an active calibration target. The EM simulation tool FEKO was used to generate simulated results. The full-wave multi-level fast multipole method (MLFMM) simulated results together with the measured data were used as reference for validation. The accuracy of physical optics (PO) and geometrical optics (GO) was investigated. Differences relating to amplitude, lobing structure and null positions were observed between the asymptotic, full-wave and measured data. PO and GO were more accurate at angles close to the specular scattering directions and the accuracy seemed to decrease as the bistatic angle increased. At large bistatic angles PO did not perform well due to the shadow regions not being treated appropriately. PO also did not perform well for canonical structures where multi-bounce was the main scattering mechanism. PO and GO do not account for diffraction but these inaccuracies tended to decrease as the electrical size of objects increased. It was evident that both asymptotic techniques do not properly account for bistatic structural shadowing. Specular scattering was calculated accurately even if targets did not meet the electrically large criteria. It was evident that the bistatic RCS prediction performance of PO and GO depends on incident angle, frequency, target shape and observation angle. The improved computational efficiency of the asymptotic solvers yields a major advantage over full-wave solvers and measurements; however, there is still much room for improvement of the accuracy of these asymptotic techniques.Keywords: asymptotic techniques, bistatic RCS, geometrical optics, physical optics
Procedia PDF Downloads 2617782 Numerical Evolution Methods of Rational Form for Diffusion Equations
Authors: Said Algarni
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The purpose of this study was to investigate selected numerical methods that demonstrate good performance in solving PDEs. We adapted alternative method that involve rational polynomials. Padé time stepping (PTS) method, which is highly stable for the purposes of the present application and is associated with lower computational costs, was applied. Furthermore, PTS was modified for our study which focused on diffusion equations. Numerical runs were conducted to obtain the optimal local error control threshold.Keywords: Padé time stepping, finite difference, reaction diffusion equation, PDEs
Procedia PDF Downloads 3007781 Application of Strength Criteria for Cellular Pressure Vessels
Authors: Antanas Žiliukas, Mindaugas Kukis
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The work deals with cellular pressure vessels subjected to internal pressure. Their cellular insert can be used for placing liquids or gases, which is necessary to carry out technological processes, and the vessel itself has a good bearing capacity. Numerical calculations of the three core structures, which measure the influence of the inner cylinder thickness on maximum bearing capacity are presented. The calculations are compared using strength criteria and they show the different strength safety level.Keywords: pressure, strength criterion, sandwich plate, cellular vessel
Procedia PDF Downloads 3107780 Delivery of Contraceptive and Maternal Health Commodities with Drones in the Most Remote Areas of Madagascar
Authors: Josiane Yaguibou, Ngoy Kishimba, Issiaka V. Coulibaly, Sabrina Pestilli, Falinirina Razanalison, Hantanirina Andremanisa
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Background: Madagascar has one of the least developed road networks in the world with a majority of its national and local roads being earth roads and in poor condition. In addition, the country is affected by frequent natural disasters that further affect the road conditions limiting the accessibility to some parts of the country. In 2021 and 2022, 2.21 million people were affected by drought in the Grand Sud region, and by cyclones and floods in the coastal regions, with disruptions of the health system including last mile distribution of lifesaving maternal health commodities and reproductive health commodities in the health facilities. Program intervention: The intervention uses drone technology to deliver maternal health and family planning commodities in hard-to-reach health facilities in the Grand Sud and Sud-Est of Madagascar, the regions more affected by natural disasters. Methodology The intervention was developed in two phases. A first phase, conducted in the Grand Sud, used drones leased from a private company to deliver commodities in isolated health facilities. Based on the lesson learnt and encouraging results of the first phase, in the second phase (2023) the intervention has been extended to the Sud Est regions with the purchase of drones and the recruitment of pilots to reduce costs and ensure sustainability. Key findings: The drones ensure deliveries of lifesaving commodities in the Grand Sud of Madagascar. In 2023, 297 deliveries in commodities in forty hard-to-reach health facilities have been carried out. Drone technology reduced delivery times from the usual 3 - 7 days necessary by road or boat to only a few hours. Program Implications: The use of innovative drone technology demonstrated to be successful in the Madagascar context to reduce dramatically the distribution time of commodities in hard-to-reach health facilities and avoid stockouts of life-saving medicines. When the intervention reaches full scale with the completion of the second phase and the extension in the Sud-Est, 150 hard-to-reach facilities will receive drone deliveries, avoiding stockouts and improving the quality of maternal health and family planning services offered to 1,4 million people in targeted areas.Keywords: commodities, drones, last-mile distribution, lifesaving supplies
Procedia PDF Downloads 667779 Integration of a Protective Film to Enhance the Longevity and Performance of Miniaturized Ion Sensors
Authors: Antonio Ruiz Gonzalez, Kwang-Leong Choy
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The measurement of electrolytes has a high value in the clinical routine. Ions are present in all body fluids with variable concentrations and are involved in multiple pathologies such as heart failures and chronic kidney disease. In the case of dissolved potassium, although a high concentration in the blood (hyperkalemia) is relatively uncommon in the general population, it is one of the most frequent acute electrolyte abnormalities. In recent years, the integration of thin films technologies in this field has allowed the development of highly sensitive biosensors with ultra-low limits of detection for the assessment of metals in liquid samples. However, despite the current efforts in the miniaturization of sensitive devices and their integration into portable systems, only a limited number of successful examples used commercially can be found. This fact can be attributed to a high cost involved in their production and the sustained degradation of the electrodes over time, which causes a signal drift in the measurements. Thus, there is an unmet necessity for the development of low-cost and robust sensors for the real-time monitoring of analyte concentrations in patients to allow the early detection and diagnosis of diseases. This paper reports a thin film ion-selective sensor for the evaluation of potassium ions in aqueous samples. As an alternative for this fabrication method, aerosol assisted chemical vapor deposition (AACVD), was applied due to cost-effectivity and fine control over the film deposition. Such a technique does not require vacuum and is suitable for the coating of large surface areas and structures with complex geometries. This approach allowed the fabrication of highly homogeneous surfaces with well-defined microstructures onto 50 nm thin gold layers. The degradative processes of the ubiquitously employed poly (vinyl chloride) membranes in contact with an electrolyte solution were studied, including the polymer leaching process, mechanical desorption of nanoparticles and chemical degradation over time. Rational design of a protective coating based on an organosilicon material in combination with cellulose to improve the long-term stability of the sensors was then carried out, showing an improvement in the performance after 5 weeks. The antifouling properties of such coating were assessed using a cutting-edge quartz microbalance sensor, allowing the quantification of the adsorbed proteins in the nanogram range. A correlation between the microstructural properties of the films with the surface energy and biomolecules adhesion was then found and used to optimize the protective film.Keywords: hyperkalemia, drift, AACVD, organosilicon
Procedia PDF Downloads 1257778 Development of Metal-Organic Frameworks-Type Hybrid Functionalized Materials for Selective Uranium Extraction
Authors: Damien Rinsant, Eugen Andreiadis, Michael Carboni, Daniel Meyer
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Different types of materials have been developed for the solid/liquid uranium extraction processes, such as functionalized organic polymers, hybrid silica or inorganic adsorbents. In general, these materials exhibit a moderate affinity for uranyl ions and poor selectivity against impurities like iron, vanadium or molybdenum. Moreover, the structural organization deficiency of these materials generates ion diffusion issues inside the material. Therefore, the aim of our study is to developed efficient and organized materials, stable in the acid media encountered in uranium extraction processes. Metal organic frameworks (MOFs) are hybrid crystalline materials consisting of an inorganic part (cluster or metal ions) and tailored organic linkers connected via coordination bonds. These hierarchical materials have exceptional surface area, thermal stability and a large variety of tunable structures. However, due to the reversibility of constitutive coordination bonds, MOFs have moderate stability in strongly complexing or acidic media. Only few of them are known to be stable in aqueous media and only one example is described in strong acidic media. However, these conditions are very often encountered in the environmental pollution remediation of mine wastewaters. To tackle the challenge of developing MOFs adapted for uranium extraction from acid mine waters, we have investigated the stability of several materials. To ensure a good stability we have synthetized and characterized different materials based on highly coordinated metal clusters, such as LnOFs and Zirconium based materials. Among the latter, the UiO family shows a great stability in sulfuric acid media even in the presence of 1.4 M sodium sulfate at pH 2. However, the stability in phosphoric media is reduced due to the high affinity between zirconium and phosphate ligand. Based on these results, we have developed a tertiary amine functionalized MOF denoted UiO-68-NMe2 particularly adapted for the extraction of anionic uranyl (VI) sulfate complexes mainly present in the acid mine solutions. The adsorption capacity of the material has been determined upon varying total sulfate concentration, contact time and uranium concentration. The extraction tests put in evidence different phenomena due to the complexity of the extraction media and the interaction between the MOF and sulfate anion. Finally, the extraction mechanisms and the interaction between uranyl and the MOF structure have been investigated. The functionalized material UiO-68-NMe2 has been characterized in the presence and absence of uranium by FT-IR, UV and Raman techniques. Moreover, the stability of the protonated amino functionalized MOF has been evaluated. The synthesis, characterization and evaluation of this type of hybrid material, particularly adapted for uranium extraction in sulfuric acid media by an anionic exchange mechanism, paved the way for the development of metal organic frameworks functionalized by different other chelating motifs, such as bifunctional ligands showing an enhanced affinity and selectivity for uranium in acid and complexing media. Work in this direction is currently in progress.Keywords: extraction, MOF, ligand, uranium
Procedia PDF Downloads 1627777 In vitro Susceptibility of Isolated Shigella flexneri and Shigella dysenteriae to the Ethanolic Extracts of Trachyspermum ammi and Peganum harmala
Authors: Ibrahim Siddig Hamid, Ikram Mohamed Eltayeb
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Trachyspermum ammi belongs to the family Apiaceae, is used traditionally for the treatment of gastrointestinal ailments, lack of appetite and bronchial problems as well used as antiseptic, antimicrobial, antipyretic, febrifugal and in the treatment of typhoid fever. Peganum harmala belongs to the family Zygophyllaceae it has been reported to have an antibacterial activity and used to treat depression and recurring fevers. It also used to kill algae, bacteria, intestinal parasites and molds. In Sudan, the combination of two plants are traditionally used for the treatment of bacillary dysentery. Bacillary dysentery is caused by one or more types of Shigella species bacteria mainly Shigella dysenteri and shigella flexneri. Bacillary dysentery is mainly found in hot countries like Sudan with poor hygiene and sanitation. Bacillary dysentery causes sudden onset of high fever and chills, abdominal pain, cramps and bloating, urgency to pass stool, weight loss, and dehydration and if left untreated it can lead to serious complications including delirium, convulsions and coma. A serious infection like this can be fatal within 24 hours. The objective of this study is to investigate the in vitro susceptibility of Sh. flexneri and Sh. dysenteriae to the T. ammi and P. harmala. T. ammi and P. harmala were extracted by 96% ethanol using Soxhlet apparatus. The antimicrobial activity of the extracts was investigated according to the disc diffusion method. The discs were prepared by soaking sterilized filter paper discs in 20 microliter of serially diluted solutions of each plant extract with the concentrations (100, 50, 25, 12.5, 6.25mg/dl) then placing them on Muller Hinton Agar plates that were inoculated with bacterial suspension separately, the plates were incubated for 24 hours at 37c and the minimum inhibitory concentration of the extract which was the least concentration of the extract to inhibit fungal growth was determined. The results showed the high antimicrobial activity of T. ammi extract with an average diameter zone ranging from 18-20 mm and its minimum inhibitory concentration was found to be 25 mg/ml against the two shigella species. P. harmala extract was found to have slight antibacterial effect against the two bacteria. This result justified the Sudanese traditional use of Trachyspermum ammi plant for the treatment of bacillary dysentery.Keywords: harmala, peganum, shigella, trachyspermum
Procedia PDF Downloads 2457776 An Analysis of Mongolian Possessive Markers
Authors: Yaxuan Wang
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It has long been a mystery that why the Mongolian possessive suffix, which is constrained by Condition A of binding theory, has the ability to probe a potential antecedent outside of its binding domain. This squib argues that binding theory alone is not sufficient to explain the linguistic facts and proposes an analysis adopting the Agree operation. The current analysis correctly predicts all the possible and impossible structures, with an additional hypothesis that Mongolian possessive suffixes serve as an antecedent for PROs in adjunct. The findings thus provide insights into how Agree operates in Mongolian language.Keywords: syntax, Mongolian, agreement, possessive particles
Procedia PDF Downloads 1027775 Climate Change and Rural-Urban Migration in Brazilian Semiarid Region
Authors: Linda Márcia Mendes Delazeri, Dênis Antônio Da Cunha
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Over the past few years, the evidence that human activities have altered the concentration of greenhouse gases in the atmosphere have become stronger, indicating that this accumulation is the most likely cause of climate change observed so far. The risks associated with climate change, although uncertain, have the potential to increase social vulnerability, exacerbating existing socioeconomic challenges. Developing countries are potentially the most affected by climate change, since they have less potential to adapt and are those most dependent on agricultural activities, one of the sectors in which the major negative impacts are expected. In Brazil, specifically, it is expected that the localities which form the semiarid region are among the most affected, due to existing irregularity in rainfall and high temperatures, in addition to economic and social factors endemic to the region. Given the strategic limitations to handle the environmental shocks caused by climate change, an alternative adopted in response to these shocks is migration. Understanding the specific features of migration flows, such as duration, destination and composition is essential to understand the impacts of migration on origin and destination locations and to develop appropriate policies. Thus, this study aims to examine whether climatic factors have contributed to rural-urban migration in semiarid municipalities in the recent past and how these migration flows will be affected by future scenarios of climate change. The study was based on microeconomic theory of utility maximization, in which, to decide to leave the countryside and move on to the urban area, the individual seeks to maximize its utility. Analytically, we estimated an econometric model using the modeling of Fixed Effects and the results confirmed the expectation that climate drivers are crucial for the occurrence of the rural-urban migration. Also, other drivers of the migration process, as economic, social and demographic factors were also important. Additionally, predictions about the rural-urban migration motivated by variations in temperature and precipitation in the climate change scenarios RCP 4.5 and 8.5 were made for the periods 2016-2035 and 2046-2065, defined by the Intergovernmental Panel on Climate Change (IPCC). The results indicate that there will be increased rural-urban migration in the semiarid region in both scenarios and in both periods. In general, the results of this study reinforce the need for formulations of public policies to avoid migration for climatic reasons, such as policies that give support to the productive activities generating income in rural areas. By providing greater incentives for family agriculture and expanding sources of credit for the farmer, it will have a better position to face climate adversities and to settle in rural areas. Ultimately, if migration becomes necessary, there must be the adoption of policies that seek an organized and planned development of urban areas, considering migration as an adaptation strategy to adverse climate effects. Thus, policies that act to absorb migrants in urban areas and ensure that they have access to basic services offered to the urban population would contribute to the social costs reduction of climate variability.Keywords: climate change, migration, rural productivity, semiarid region
Procedia PDF Downloads 3527774 Analyzing the Effects of Bio-fibers on the Stiffness and Strength of Adhesively Bonded Thermoplastic Bio-fiber Reinforced Composites by a Mixed Experimental-Numerical Approach
Authors: Sofie Verstraete, Stijn Debruyne, Frederik Desplentere
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Considering environmental issues, the interest to apply sustainable materials in industry increases. Specifically for composites, there is an emerging need for suitable materials and bonding techniques. As an alternative to traditional composites, short bio-fiber (cellulose-based flax) reinforced Polylactic Acid (PLA) is gaining popularity. However, these thermoplastic based composites show issues in adhesive bonding. This research focusses on analyzing the effects of the fibers near the bonding interphase. The research applies injection molded plate structures. A first important parameter concerns the fiber volume fraction, which directly affects adhesion characteristics of the surface. This parameter is varied between 0 (pure PLA) and 30%. Next to fiber volume fraction, the orientation of fibers near the bonding surface governs the adhesion characteristics of the injection molded parts. This parameter is not directly controlled in this work, but its effects are analyzed. Surface roughness also greatly determines surface wettability, thus adhesion. Therefore, this research work considers three different roughness conditions. Different mechanical treatments yield values up to 0.5 mm. In this preliminary research, only one adhesive type is considered. This is a two-part epoxy which is cured at 23 °C for 48 hours. In order to assure a dedicated parametric study, simple and reproduceable adhesive bonds are manufactured. Both single lap (substrate width 25 mm, thickness 3 mm, overlap length 10 mm) and double lap tests are considered since these are well documented and quite straightforward to conduct. These tests are conducted for the different substrate and surface conditions. Dog bone tensile testing is applied to retrieve the stiffness and strength characteristics of the substrates (with different fiber volume fractions). Numerical modelling (non-linear FEA) relates the effects of the considered parameters on the stiffness and strength of the different joints, obtained through the abovementioned tests. Ongoing work deals with developing dedicated numerical models, incorporating the different considered adhesion parameters. Although this work is the start of an extensive research project on the bonding characteristics of thermoplastic bio-fiber reinforced composites, some interesting results are already prominent. Firstly, a clear correlation between the surface roughness and the wettability of the substrates is observed. Given the adhesive type (and viscosity), it is noticed that an increase in surface energy is proportional to the surface roughness, to some extent. This becomes more pronounced when fiber volume fraction increases. Secondly, ultimate bond strength (single lap) also increases with increasing fiber volume fraction. On a macroscopic level, this confirms the positive effect of fibers near the adhesive bond line.Keywords: adhesive bonding, bio-fiber reinforced composite, flax fibers, lap joint
Procedia PDF Downloads 1297773 Level of Caregiver Burden: A Study of Caregivers of Stroke Survivors at CRP in Bangladesh
Authors: Yeasir Arafat Alve, Nazmun Nahar, Salma BeguM
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Introduction / Rationale: Caregivers of stroke survivors have experienced financial, emotional, physical and mental anxiety and have influence of family bonding and social customs, where 80% of caregivers were women and majority of the patients were cared for by immediate family members for example a spouse, son/daughter, son-in-law, daughter-in-law, siblings and they are significantly feel burden as a caregiver. In Bangladeshi context, there has a limitation of knowledge about the level of caregiver burden. This study could be suggested the health professional to focus on the care giving stress to provide a better support to them and also it will be advisable to provide equivalent services for caregivers and their families. Objectives: The study finds out the socio-demographic image of caregivers of stroke survivors in Bangladesh as well as discovers the level of burden of caregiver of stroke survivor in relation to general strain, isolation, disappointment, emotional involvement and environment. The study will find out the association between level of burden among caregivers and onset of stroke of survivors & duration of care giving. As well as to determine the association between level of burden among caregivers and caregiver’s age, gender, occupation and caregiver’s relationship with stroke survivors. Method / Approach: The study is a non experimental cross-sectional study design where 151 participants were selected through purposive comprehensive sampling. Data were selected from occupational therapy outdoor and stroke rehab unit, CRP (Savar & Mirpur) where using the Caregiver Burden Scale (a structured questionnaire) with face to face interview. Results: Most of the caregivers (78.8%) of stroke survivors faced moderate level of burden in general strain (37.7%), isolation (27.2%) but in case of disappointment (60.3%) feel higher burden and lower burden in emotional involvement (9.9%) and environment (0.7%). Caregiver burden level was significantly associated with caregivers’ age (P=0.006), sex (P=0.002), occupation (p= 0.04), relationship with stroke survivors (P=0.02), care giving duration (P=0.000), care giving hours (P=0.009), and onset of stroke (P=0.000) of stroke survivors. Conclusion: The study findings revealed that most of the caregivers faced moderate burden where no environmental burden for them, this is possibly in case of Bangladeshi culture where people hospitable. Through this study, it was also found that there is a possibility to have the higher burden. Finally, it is being also suggested that appropriate advice and support may preserve care giving which eventually enables the survivors to live a longer and more fulfilling life in the community.Keywords: caregiver, level of caregiver burden, stroke survivor, stroke rehab unit
Procedia PDF Downloads 3137772 Home Education in the Australian Context
Authors: Abeer Karaali
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This paper will seek to clarify important key terms such as home schooling and home education as well as the legalities attached to such terms. It will reflect on the recent proposed changes to terminology in NSW, Australia. The various pedagogical approaches to home education will be explored including their prominence in the Australian context. There is a strong focus on literature from Australia. The historical background of home education in Australia will be explained as well as the difference between distance education and home education. The statistics related to home education in Australia will be explored in the scope and compared to the US. The future of home education in Australia will be discussed.Keywords: alternative education, e-learning, home education, home schooling, online resources, technology
Procedia PDF Downloads 4097771 Using a Phenomenological Approach to Explore the Experiences of Nursing Students in Coping with Their Emotional Responses in Caring for End-Of-Life Patients
Authors: Yun Chan Lee
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Background: End-of-life care is a large area of all nursing practice and student nurses are likely to meet dying patients in many placement areas. It is therefore important to understand the emotional responses and coping strategies of student nurses in order for nursing education systems to have some appreciation of how nursing students might be supported in the future. Methodology: This research used a qualitative phenomenological approach. Six student nurses understanding a degree-level adult nursing course were interviewed. Their responses to questions were analyzed using interpretative phenomenological analysis. Finding: The findings identified 3 main themes. First, the common experience of ‘unpreparedness’. A very small number of participants felt that this was unavoidable and that ‘no preparation is possible’, the majority felt that they were unprepared because of ‘insufficient input’ from the university and as a result of wider ‘social taboos’ around death and dying. The second theme showed that emotions were affected by ‘the personal connection to the patient’ and the important sub-themes of ‘the evoking of memories’, ‘involvement in care’ and ‘sense of responsibility’. The third theme, the coping strategies used by students, seemed to fall into two broad areas those ‘internal’ with the student and those ‘external’. In terms of the internal coping strategies, ‘detachment’, ‘faith’, ‘rationalization’ and ‘reflective skills’ are the important components of this part. Regarding the external coping strategies, ‘clinical staff’ and ‘the importance of family and friends’ are the importance of accessing external forms of support. Implication: It is clear that student nurses are affected emotionally by caring for dying patients and many of them have apprehension even before they begin on their placements but very often this is unspoken. Those anxieties before the placement become more pronounced during and continue after the placements. This has implications for when support is offered and possibly its duration. Another significant point of the study is that participants often highlighted their wish to speak to qualified nurses after their experiences of being involved in end-of-life care and especially when they had been present at the time of death. Many of the students spoke that qualified nurses were not available to them. This seemed to be due to a number of reasons. Because the qualified nurses were not available, students had to make use of family members and friends to talk to. Consequently, the implication of this study is not only to educate student nurses but also to educate the qualified mentors on the importance of providing emotional support to students.Keywords: nursing students, coping strategies, end-of-life care, emotional responses
Procedia PDF Downloads 1637770 [Keynote Speech]: Facilitating Familial Support of Saudi Arabians Living with HIV/AIDS
Authors: Noor Attar
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The paper provides an overview of the current situation of HIV/AIDS patients in the Kingdom of Saudi Arabia (KSA) and a literature review of the concepts of stigma communication, communication of social support. These concepts provide the basis for the proposed methods, which will include conducting a textual analysis of materials that are currently distributed to family members of persons living with HIV/AIDS (PLWHIV/A) in KSA and creating an educational brochure. The brochure will aim to help families of PLWHIV/A in KSA (1) understand how stigma shapes the experience of PLWHIV/A, (2) realize the role of positive communication as a helpful social support, and (3) develop the ability to provide positive social support for their loved ones. Procedia PDF Downloads 3127769 Checklist for Autism Spectrum Disorder as an In-Class Observation Tool for Teachers
Authors: Werona Król-Gierat
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The majority of Special Educational Needs checklists are intended for preliminary screening in the special education disability process. The aim of the present paper is to present their potential usefulness as in-class observation tools for teachers working with students who have already been diagnosed with a disorder. A checklist may complement and organize information about a given child, which is indispensable to improve his or her condition. The case of a Polish boy with autism will serve as an example. Last but not the least, alternative uses of checklists are suggested in the article.Keywords: autism spectrum disorders, case study, checklist, observation tool
Procedia PDF Downloads 364