Search results for: theoretical solar radiation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5954

Search results for: theoretical solar radiation

1034 Upgrade of Value Chains and the Effect on Resilience of Russia’s Coal Industry and Receiving Regions on the Path of Energy Transition

Authors: Sergey Nikitenko, Vladimir Klishin, Yury Malakhov, Elena Goosen

Abstract:

Transition to renewable energy sources (solar, wind, bioenergy, etc.) and launching of alternative energy generation has weakened the role of coal as a source of energy. The Paris Agreement and assumption of obligations by many nations to orderly reduce CO₂ emissions by means of technological modernization and climate change adaptation has abridged coal demand yet more. This paper aims to assess current resilience of the coal industry to stress and to define prospects for coal production optimization using high technologies pursuant to global challenges and requirements of energy transition. Our research is based on the resilience concept adapted to the coal industry. It is proposed to divide the coal sector into segments depending on the prevailing value chains (VC). Four representative models of VC are identified in the coal sector. The most promising lines of upgrading VC in the coal industry include: •Elongation of VC owing to introduction of clean technologies of coal conversion and utilization; •Creation of parallel VC by means of waste management; •Branching of VC (conversion of a company’s VC into a production network). The upgrade effectiveness is governed in many ways by applicability of advanced coal processing technologies, usability of waste, expandability of production, entrance to non-rival markets and localization of new segments of VC in receiving regions. It is also important that upgrade of VC by means of formation of agile high-tech inter-industry production networks within the framework of operating surface and underground mines can reduce social, economic and ecological risks associated with closure of coal mines. Such promising route of VC upgrade is application of methanotrophic bacteria to produce protein to be used as feed-stuff in fish, poultry and cattle breeding, or in production of ferments, lipoids, sterols, antioxidants, pigments and polysaccharides. Closed mines can use recovered methane as a clean energy source. There exist methods of methane utilization from uncontrollable sources, including preliminary treatment and recovery of methane from air-and-methane mixture, or decomposition of methane to hydrogen and acetylene. Separated hydrogen is used in hydrogen fuel cells to generate power to feed the process of methane utilization and to supply external consumers. Despite the recent paradigm of carbon-free energy generation, it is possible to preserve the coal mining industry using the differentiated approach to upgrade of value chains based on flexible technologies with regard to specificity of mining companies.

Keywords: resilience, resilience concept, resilience indicator, resilience in the Russian coal industry, value chains

Procedia PDF Downloads 105
1033 High Efficiency Double-Band Printed Rectenna Model for Energy Harvesting

Authors: Rakelane A. Mendes, Sandro T. M. Goncalves, Raphaella L. R. Silva

Abstract:

The concepts of energy harvesting and wireless energy transfer have been widely discussed in recent times. There are some ways to create autonomous systems for collecting ambient energy, such as solar, vibratory, thermal, electromagnetic, radiofrequency (RF), among others. In the case of the RF it is possible to collect up to 100 μW / cm². To collect and/or transfer energy in RF systems, a device called rectenna is used, which is defined by the junction of an antenna and a rectifier circuit. The rectenna presented in this work is resonant at the frequencies of 1.8 GHz and 2.45 GHz. Frequencies at 1.8 GHz band are e part of the GSM / LTE band. The GSM (Global System for Mobile Communication) is a frequency band of mobile telephony, it is also called second generation mobile networks (2G), it came to standardize mobile telephony in the world and was originally developed for voice traffic. LTE (Long Term Evolution) or fourth generation (4G) has emerged to meet the demand for wireless access to services such as Internet access, online games, VoIP and video conferencing. The 2.45 GHz frequency is part of the ISM (Instrumentation, Scientific and Medical) frequency band, this band is internationally reserved for industrial, scientific and medical development with no need for licensing, and its only restrictions are related to maximum power transfer and bandwidth, which must be kept within certain limits (in Brazil the bandwidth is 2.4 - 2.4835 GHz). The rectenna presented in this work was designed to present efficiency above 50% for an input power of -15 dBm. It is known that for wireless energy capture systems the signal power is very low and varies greatly, for this reason this ultra-low input power was chosen. The Rectenna was built using the low cost FR4 (Flame Resistant) substrate, the antenna selected is a microfita antenna, consisting of a Meandered dipole, and this one was optimized using the software CST Studio. This antenna has high efficiency, high gain and high directivity. Gain is the quality of an antenna in capturing more or less efficiently the signals transmitted by another antenna and/or station. Directivity is the quality that an antenna has to better capture energy in a certain direction. The rectifier circuit used has series topology and was optimized using Keysight's ADS software. The rectifier circuit is the most complex part of the rectenna, since it includes the diode, which is a non-linear component. The chosen diode is the Schottky diode SMS 7630, this presents low barrier voltage (between 135-240 mV) and a wider band compared to other types of diodes, and these attributes make it perfect for this type of application. In the rectifier circuit are also used inductor and capacitor, these are part of the input and output filters of the rectifier circuit. The inductor has the function of decreasing the dispersion effect on the efficiency of the rectifier circuit. The capacitor has the function of eliminating the AC component of the rectifier circuit and making the signal undulating.

Keywords: dipole antenna, double-band, high efficiency, rectenna

Procedia PDF Downloads 118
1032 The Impact of the Atypical Crisis on Educational Migration: Economic and Policy Challenges

Authors: Manana Lobzhanidze, Marine Kobalava, Lali Chikviladze

Abstract:

The global pandemic crisis has had a significant impact on educational migration, substantially limiting young people’s access to education abroad. Therefore, it became necessary to study the economic, demographic, social, cultural and other factors associated with educational migration, to identify the economic and political challenges of educational migration and to develop recommendations. The aim of the research is to study the effects of the atypical crisis on educational migration and to make recommendations on effective migration opportunities based on the identification of economic and policy challenges in this area. Bibliographic research is used to assess the effects of the impact of the atypical crisis on educational migration presented in the papers of various scholars. Against the background of the restrictions imposed during the COVID19 pandemic, migration rates have been analyzed, endogenous and exogenous factors affecting educational migration have been identified. Quantitative and qualitative research of students and graduates of TSU Economics and Business Faculty is conducted, the results have been processed by SPSS program, the factors hindering educational migration and the challenges have been identified. The Internet and digital technologies have been shown to play a vital role in alleviating the challenges posed by the COVID-19 pandemic, however, lack of Internet access and limited financial resources have played a disruptive role in the educational migration process. The analysis of quantitative research materials revealed the problems of educational migration caused by the atypical crisis, while some issues were clarified during the focus group meetings. The following theoretical-methodological approaches were used during the research: a bibliographic research, analysis, synthesis, comparison, selection-grouping are used; Quantitative and qualitative research has been carried out, the results have been processed by SPSS program. The article presents the consequences of the atypical crisis for educational migration, identifies the main economic and policy challenges in the field of educational migration, and develops appropriate recommendations to overcome them.

Keywords: educational migration, atypical crisis, economic-political challenges, educational migration factors

Procedia PDF Downloads 141
1031 The Elimination of Fossil Fuel Subsidies from the Road Transportation Sector and the Promotion of Electro Mobility: The Ecuadorian Case

Authors: Henry Gonzalo Acurio Flores, Alvaro Nicolas Corral Naveda, Juan Francisco Fonseca Palacios

Abstract:

In Ecuador, subventions on fossil fuels for the road transportation sector have always been part of its economy throughout time, mainly because of demagogy and populism from political leaders. It is clearly seen that the government cannot maintain the subsidies anymore due to its commercial balance and its general state budget; subsidies are a key barrier to implementing the use of cleaner technologies. However, during the last few months, the elimination of subsidies has been done gradually with the purpose of reaching international prices. It is expected that with this measure, the population will opt for other means of transportation, and in a certain way, it will promote the use of private electric vehicles and public, e.g., taxis and buses (urban transport). Considering the three main elements of sustainable development, an analysis of the social, economic, and environmental impacts of eliminating subsidies will be generated at the country level. To achieve this, four scenarios will be developed in order to determine how the subsidies will contribute to the promotion of electro-mobility. 1) A Business as Usual BAU scenario; 2) the introduction of 10 000 electric vehicles by 2025; 3) the introduction of 100 000 electric vehicles by 2030; 4) the introduction of 750 000 electric vehicles by 2040 (for all the scenarios buses, taxis, lightweight duty vehicles, and private vehicles will be introduced, as it is established in the National Electro Mobility Strategy for Ecuador). The Low Emissions Analysis Platform (LEAP) will be used, and it will be suitable to determine the cost for the government in terms of importing derivatives for fossil fuels and the cost of electricity to power the electric fleet that can be changed. The elimination of subventions generates fiscal resources for the state that can be used to develop other kinds of projects that will benefit Ecuadorian society. It will definitely change the energy matrix, and it will provide energy security for the country; it will be an opportunity for the government to incentivize a greater introduction of renewable energies, e.g., solar, wind, and geothermal. At the same time, it will also reduce greenhouse gas emissions (GHG) from the transportation sector, considering its mitigation potential, which as a result, will ameliorate the inhabitant quality of life by improving the quality of air, therefore reducing respiratory diseases associated with exhaust emissions, consequently, achieving sustainability, the Sustainable Development Goals (SDGs), and complying with the agreements established in the Paris Agreement COP 21 in 2015. Electro mobility in Latin America and the Caribbean can only be achieved by the implementation of the right policies at the central government, which need to be accompanied by a National Urban Mobility Policy (NUMP) and can encompass a greater vision to develop holistic, sustainable transport systems at local governments.

Keywords: electro mobility, energy, policy, sustainable transportation

Procedia PDF Downloads 81
1030 The Photovoltaic Panel at End of Life: Experimental Study of Metals Release

Authors: M. Tammaro, S. Manzo, J. Rimauro, A. Salluzzo, S. Schiavo

Abstract:

The solar photovoltaic (PV) modules are considered to have a negligible environmental impact compared to the fossil energy. Therefore also the waste management and the corresponding potential environmental hazard needs to be considered. The case of the photovoltaic panel is unique because the time lag from the manufacturing to the decommissioning as waste usually takes 25-30 years. Then the environmental hazard associated with end life of PV panels has been largely related to their metal contents. The principal concern regards the presence of heavy metals as Cd in thin film (TF) modules or Pb and Cr in crystalline silicon (c-Si) panels. At the end of life of PV panels, these dangerous substances could be released in the environment, if special requirements for their disposal are not adopted. Nevertheless, in literature, only a few experimental study about metal emissions from silicon crystalline/thin film panels and the corresponding environmental effect are present. As part of a study funded by the Italian national consortium for the waste collection and recycling (COBAT), the present work was aimed to analyze experimentally the potential release into the environment of hazardous elements, particularly metals, from PV waste. In this paper, for the first time, eighteen releasable metals a large number of photovoltaic panels, by c-Si and TF, manufactured in the last 30 years, together with the environmental effects by a battery of ecotoxicological tests, were investigated. Leaching tests are conducted on the crushed samples of PV module. The test is conducted according to Italian and European Standard procedure for hazard assessment of the granular waste and of the sludge. The sample material is shaken for 24 hours in HDPE bottles with an overhead mixer Rotax 6.8 VELP at indoor temperature and using pure water (18 MΩ resistivity) as leaching solution. The liquid-to-solid ratio was 10 (L/S=10, i.e. 10 liters of water per kg of solid). The ecotoxicological tests were performed in the subsequent 24 hours. A battery of toxicity test with bacteria (Vibrio fisheri), algae (Pseudochirneriella subcapitata) and crustacea (Daphnia magna) was carried out on PV panel leachates obtained as previously described and immediately stored in dark and at 4°C until testing (in the next 24 hours). For understand the actual pollution load, a comparison with the current European and Italian benchmark limits was performed. The trend of leachable metal amount from panels in relation to manufacturing years was then highlighted in order to assess the environmental sustainability of PV technology over time. The experimental results were very heterogeneous and show that the photovoltaic panels could represent an environmental hazard. The experimental results showed that the amounts of some hazardous metals (Pb, Cr, Cd, Ni), for c-Si and TF, exceed the law limits and they are a clear indication of the potential environmental risk of photovoltaic panels "as a waste" without a proper management.

Keywords: photovoltaic panel, environment, ecotoxicity, metals emission

Procedia PDF Downloads 257
1029 Cannabis Use Reported by Patients in an Academic Medical Practice

Authors: Siddhant Yadav, Ann Vincent, Sanjeev Nanda, Karen M. Fischer, Jessica A. Wright

Abstract:

Statement of the Problem: Despite the growing popularity of cannabis in the general population, there are several unknowns regarding its use, specific reasons for use, patient’s choice of products, health benefits, and adverse effects. The aim of our study was to evaluate patient-reported information related to cannabis use that was recorded in the electronic medical records. Methodology & Theoretical Orientation: We manually reviewed the electronic medical records of cannabis users who were part of a large pharmacogenomic study. Data abstracted included demographics, level of education, concurrent alcohol and tobacco use, type of cannabis utilized, formulation, indication, symptomatic improvement, or adverse effects reported. Following this, we did a descriptive statistical analysis. Findings: Our sample of 164 cannabis users were predominantly female (73.2%); 66% of users reported using cannabis for medical indications. Of the 109 patients who recorded information pertaining to alcohol/tobacco use, two-thirds of cannabis users reported concurrent use of alcohol, and about half of them were former or current tobacco users. The mean age of cannabis use was 66 years. Regarding the type of cannabis, 34.1% reported using marijuana, 32.3% reported CBD use, 1.8% reported using THC, and 1.2% reported using Marinol. Oral formulations (capsules, oils, suspensions, brownies, cakes, and tea) were the most common route (44 %). Indications for use included chronic pain (n=76), anxiety (n=9), counteracting side effects of chemotherapy (n=4), and palliative reasons (n=2). Fifty-eight of the 76 users endorsed improvement in chronic pain (80%), 5 users reported improvement in anxiety, and 2 reported improvement in side effects of chemotherapy. Conclusion & Significance: The majority of our cannabis users were Caucasian females, and there was a high likelihood of coinciding use of alcohol/tobacco in patients using cannabis. Most of our patients used the oral formulation for chronic pain. Importantly, a considerable number of patients reported improvements in chronic pain, anxiety, and side effects of chemotherapy.

Keywords: cannabis use, adverse effects, medical practice, indications

Procedia PDF Downloads 91
1028 Classification of Factors Influencing Buyer-Supplier Relationship: A Case Study from the Cement Industry

Authors: Alberto Piatto, Zaza Nadja Lee Hansen, Peter Jacobsen

Abstract:

This paper examines the quantitative and qualitative factors influencing the buyer-supplier relationship. Understanding and acting on the right factors influencing supplier relationship management is crucial when a company outsource an important part of its business as it can be for engineering to order (ETO) company executing only the designing part in-house. Acting on these factors increase the quality of the relationship obtaining for both parties what they want and expect from an improved relationship. Best practices in supplier relationship management are considered and a case study of a large global company, called Cement A/S, operating in the cement business is carried out. One study is conducted including a large international company and hundreds of its suppliers. Data from the company is collected using semi-structured interviews and data from the suppliers is collected using a survey. Based on these inputs and an extensive literature review a classification of factors influencing the relationship buyer-supplier is presented and discussed. The results show that different managers among the company are assessing supplier from various perspectives, a standard approach to measure the performance of suppliers does not exist. The factors used nowadays in the company to measure performances of the suppliers are mostly related to time and cost. Quality is a key factor, but it has not been addressed properly since no data are available in the system. From a practical perspective, managers can learn from this paper which factors to consider when applying best practices of Supplier Relationship Management. Furthermore, from a theoretical perspective, this paper contributes with new knowledge in the area as limited research in collaboration with the company has been conducted. For this reason, a company, its suppliers and few studies for this type of industry have been conducted. For further research, it is suggested to define the correlation of factors to the profitability of the company and calculate its impact. When conducting this analysis it is important to focus on the efficient and effective use of factors that can be measurable and accepted from the supplier.

Keywords: buyer-supplier relationship, cement industry, classification of factors, ETO

Procedia PDF Downloads 277
1027 Graphene Metamaterials Supported Tunable Terahertz Fano Resonance

Authors: Xiaoyong He

Abstract:

The manipulation of THz waves is still a challenging task due to lack of natural materials interacted with it strongly. Designed by tailoring the characters of unit cells (meta-molecules), the advance of metamaterials (MMs) may solve this problem. However, because of Ohmic and radiation losses, the performance of MMs devices is subjected to the dissipation and low quality factor (Q-factor). This dilemma may be circumvented by Fano resonance, which arises from the destructive interference between a bright continuum mode and dark discrete mode (or a narrow resonance). Different from symmetric Lorentz spectral curve, Fano resonance indicates a distinct asymmetric line-shape, ultrahigh quality factor, steep variations in spectrum curves. Fano resonance is usually realized through symmetry breaking. However, if concentric double rings (DR) are placed closely to each other, the near-field coupling between them gives rise to two hybridized modes (bright and narrowband dark modes) because of the local asymmetry, resulting into the characteristic Fano line shape. Furthermore, from the practical viewpoint, it is highly desirable requirement that to achieve the modulation of Fano spectral curves conveniently, which is an important and interesting research topics. For current Fano systems, the tunable spectral curves can be realized by adjusting the geometrical structural parameters or magnetic fields biased the ferrite-based structure. But due to limited dispersion properties of active materials, it is still a tough work to tailor Fano resonance conveniently with the fixed structural parameters. With the favorable properties of extreme confinement and high tunability, graphene is a strong candidate to achieve this goal. The DR-structure possesses the excitation of so-called “trapped modes,” with the merits of simple structure and high quality of resonances in thin structures. By depositing graphene circular DR on the SiO2/Si/ polymer substrate, the tunable Fano resonance has been theoretically investigated in the terahertz regime, including the effects of graphene Fermi level, structural parameters and operation frequency. The results manifest that the obvious Fano peak can be efficiently modulated because of the strong coupling between incident waves and graphene ribbons. As Fermi level increases, the peak amplitude of Fano curve increases, and the resonant peak position shifts to high frequency. The amplitude modulation depth of Fano curves is about 30% if Fermi level changes in the scope of 0.1-1.0 eV. The optimum gap distance between DR is about 8-12 μm, where the value of figure of merit shows a peak. As the graphene ribbon width increases, the Fano spectral curves become broad, and the resonant peak denotes blue shift. The results are very helpful to develop novel graphene plasmonic devices, e.g. sensors and modulators.

Keywords: graphene, metamaterials, terahertz, tunable

Procedia PDF Downloads 340
1026 Modeling of Timing in a Cyber Conflict to Inform Critical Infrastructure Defense

Authors: Brian Connett, Bryan O'Halloran

Abstract:

Systems assets within critical infrastructures were seemingly safe from the exploitation or attack by nefarious cyberspace actors. Now, critical infrastructure is a target and the resources to exploit the cyber physical systems exist. These resources are characterized in terms of patience, stealth, replication-ability and extraordinary robustness. System owners are obligated to maintain a high level of protection measures. The difficulty lies in knowing when to fortify a critical infrastructure against an impending attack. Models currently exist that demonstrate the value of knowing the attacker’s capabilities in the cyber realm and the strength of the target. The shortcomings of these models are that they are not designed to respond to the inherent fast timing of an attack, an impetus that can be derived based on open-source reporting, common knowledge of exploits of and the physical architecture of the infrastructure. A useful model will inform systems owners how to align infrastructure architecture in a manner that is responsive to the capability, willingness and timing of the attacker. This research group has used an existing theoretical model for estimating parameters, and through analysis, to develop a decision tool for would-be target owners. The continuation of the research develops further this model by estimating the variable parameters. Understanding these parameter estimations will uniquely position the decision maker to posture having revealed the vulnerabilities of an attacker’s, persistence and stealth. This research explores different approaches to improve on current attacker-defender models that focus on cyber threats. An existing foundational model takes the point of view of an attacker who must decide what cyber resource to use and when to use it to exploit a system vulnerability. It is valuable for estimating parameters for the model, and through analysis, develop a decision tool for would-be target owners.

Keywords: critical infrastructure, cyber physical systems, modeling, exploitation

Procedia PDF Downloads 189
1025 Salient Beliefs regarding Alcohol Reduction and Cessation among Thai Teenagers

Authors: Panrapee Suttiwan, Rewadee Watakakosol Arunya Tuicomepee, Sakkaphat T. Ngamake

Abstract:

Alcohol consumption ranks among the top six of health-risk behaviors that lead to disability and death among Thai teenagers. Underage drinkers have higher health risks than their non-drinking peers do. This study, therefore, aimed to explore salient beliefs of Thai teenagers with alcohol reduction and cessation based on the Theory of Planned Behaviour theoretical framework. Participants were 225 high-school and vocational school students, most of whom (60.9%) consumed alcohol almost daily (5-6 times / week), and one-third of whom (33.8%) reported habitual moderate drink. The average age was 16.5 (SD = 0.9), and the average age of the first use of alcohol was 13.7 (SD = 2.2). Instrument was an open-ended questionnaire that elicited beliefs about having alcohol reduction / cessation in the past 12 months. Findings revealed salient benefit beliefs of alcohol reduction / cessation among the teens such as improved physical and mental health, accident and violence avoidance, less sexual risks, money and time saving, better academic performance, and improved relationships. In contrast, the teens identified several disadvantage beliefs such as deteriorating health, social awkwardness, lack of little fun, excitement, and experience, physical uneasiness, stress, and lack of self-confidence. Salient normative groups for alcohol reduction / cessation included parents, elder relatives, siblings, close friends, teachers, boy / girlfriends, and seniors / juniors at school. Situations influencing alcohol reduction / cessation included quarrels with boy / girlfriends, family conflicts, peer pressure, partying and socializing, festive holidays and anniversary celebration, and visiting entertainment places, etc. This study provides empirical evidence that help to identify normative attitudes towards alcohol reduction / cessation and may thus be an important knowledge for public health campaigns seeking to reduce alcohol consumption in this population.

Keywords: alcohol consumption reduction, cessation, salient belief, Thai teenagers

Procedia PDF Downloads 329
1024 The Art of Resilience in the Case of Skopje

Authors: Kristina Nikolovska

Abstract:

Social movements have become common in the Post Yugoslav cities. Consequently, the wave of activism has been considerably present in Skopje. Starting from 2009 the activist wave in Skopje emerged with the notion of the city. Diversity of initiatives appeared in the city in order to defend places that have been contested by the urban development project SK2014. The activist wave diffused into many different initiatives and diversity of issues. The result was unification in one massive movement in 2016, called 'The Colourful Revolution'. The paper explores the scope of activism in Skopje, with taking into consideration the influence of the spatial transformation, the project SK2014. Moreover, it examines the processes of spatiality into shaping the contention in Skopje, focusing on interdisciplinary and comprehensive approaches. Except the diversity of theoretical framework mainly founded on contentious politics theory and space elaboration from different perspectives, the study is founded on field work based on conducted interviews. Using an interdisciplinary approach and focusing on three main dimensions, the research contributes to understand the dynamics of the activist wave and importance of spatial processes in the creation of the contention in Skopje. Moreover, it elaborates the characteristics, possible effects, and reflections of the cycles of protests in Skopje. The main results of the research showed that dynamics of space is important in the creation of the activist wave in Skopje, moreover space context can give explanation about how opportunities diffuse and transformative power is created. The study contributed into deeper understanding of the importance of spatiality in contentious politics, it showed that in general contentions politics can benefit from deeper analyses of place specificity. Finally, the thesis opposes the traditional linear understanding of social movements, and proposes more dynamic, comprehensive, and sensitive elaboration.

Keywords: contentious politics, place, Skopje, SK2014, social movements, space

Procedia PDF Downloads 227
1023 Aerodynamic Design and Optimization of Vertical Take-Off and Landing Type Unmanned Aerial Vehicles

Authors: Enes Gunaltili, Burak Dam

Abstract:

The airplane history started with the Wright brothers' aircraft and improved day by day. With the help of this advancements, big aircrafts replace with small and unmanned air vehicles, so in this study we design this type of air vehicles. First of all, aircrafts mainly divided into two main parts in our day as a rotary and fixed wing aircrafts. The fixed wing aircraft generally use for transport, cargo, military and etc. The rotary wing aircrafts use for same area but there are some superiorities from each other. The rotary wing aircraft can take off vertically from the ground, and it can use restricted area. On the other hand, rotary wing aircrafts generally can fly lower range than fixed wing aircraft. There are one kind of aircraft consist of this two types specifications. It is named as VTOL (vertical take-off and landing) type aircraft. VTOLs are able to takeoff and land vertically and fly horizontally. The VTOL aircrafts generally can fly higher range from the rotary wings but can fly lower range from the fixed wing aircraft but it gives beneficial range between them. There are many other advantages of VTOL aircraft from the rotary and fixed wing aircraft. Because of that, VTOLs began to use for generally military, cargo, search, rescue and mapping areas. Within this framework, this study answers the question that how can we design VTOL as a small unmanned aircraft systems for search and rescue application for benefiting the advantages of fixed wing and rotary wing aircrafts by eliminating the disadvantages of them. To answer that question and design VTOL aircraft, multidisciplinary design optimizations (MDO), some theoretical terminologies, formulations, simulations and modelling systems based on CFD (Computational Fluid Dynamics) is used in same time as design methodology to determine design parameters and steps. As a conclusion, based on tests and simulations depend on design steps, suggestions on how the VTOL aircraft designed and advantages, disadvantages, and observations for design parameters are listed, then VTOL is designed and presented with the design parameters, advantages, and usage areas.

Keywords: airplane, rotary, fixed, VTOL, CFD

Procedia PDF Downloads 277
1022 The Asymptotic Hole Shape in Long Pulse Laser Drilling: The Influence of Multiple Reflections

Authors: Torsten Hermanns, You Wang, Stefan Janssen, Markus Niessen, Christoph Schoeler, Ulrich Thombansen, Wolfgang Schulz

Abstract:

In long pulse laser drilling of metals, it can be demonstrated that the ablation shape approaches a so-called asymptotic shape such that it changes only slightly or not at all with further irradiation. These findings are already known from ultra short pulse (USP) ablation of dielectric and semiconducting materials. The explanation for the occurrence of an asymptotic shape in long pulse drilling of metals is identified, a model for the description of the asymptotic hole shape numerically implemented, tested and clearly confirmed by comparison with experimental data. The model assumes a robust process in that way that the characteristics of the melt flow inside the arising melt film does not change qualitatively by changing the laser or processing parameters. Only robust processes are technically controllable and thus of industrial interest. The condition for a robust process is identified by a threshold for the mass flow density of the assist gas at the hole entrance which has to be exceeded. Within a robust process regime the melt flow characteristics can be captured by only one model parameter, namely the intensity threshold. In analogy to USP ablation (where it is already known for a long time that the resulting hole shape results from a threshold for the absorbed laser fluency) it is demonstrated that in the case of robust long pulse ablation the asymptotic shape forms in that way that along the whole contour the absorbed heat flux density is equal to the intensity threshold. The intensity threshold depends on the special material and radiation properties and has to be calibrated be one reference experiment. The model is implemented in a numerical simulation which is called AsymptoticDrill and requires such a few amount of resources that it can run on common desktop PCs, laptops or even smart devices. Resulting hole shapes can be calculated within seconds what depicts a clear advantage over other simulations presented in literature in the context of industrial every day usage. Against this background the software additionally is equipped with a user-friendly GUI which allows an intuitive usage. Individual parameters can be adjusted using sliders while the simulation result appears immediately in an adjacent window. A platform independent development allow a flexible usage: the operator can use the tool to adjust the process in a very convenient manner on a tablet during the developer can execute the tool in his office in order to design new processes. Furthermore, at the best knowledge of the authors AsymptoticDrill is the first simulation which allows the import of measured real beam distributions and thus calculates the asymptotic hole shape on the basis of the real state of the specific manufacturing system. In this paper the emphasis is placed on the investigation of the effect of multiple reflections on the asymptotic hole shape which gain in importance when drilling holes with large aspect ratios.

Keywords: asymptotic hole shape, intensity threshold, long pulse laser drilling, robust process

Procedia PDF Downloads 208
1021 Resistances among Sexual Offenders on Specific Stage of Change

Authors: Chang Li Yu

Abstract:

Resistances commonly happened during sexual offenders treatment program (SOTP), and removing resistances was one of the treatment goals on it. Studies concerning treatment effectiveness relied on pre- and post-treatment evaluations, however, no significant difference on resistance revealed after treatment, and the above consequences generally contributed to the low motivation for change instead. Therefore, the aim of this study was to investigate the resistance across each stage of change among sexual offenders (SO). The present study recruited prisoned SO in Taiwan, excluding those with literacy difficulties; finally, 272 participants were included. Of all participants completed revised version of URICA (University of Rhode Island Change Assessment) and resistance scale specifically for SO. The former included four stages of change: pre-contemplation (PC), contemplation (C), action (A), and maintain (M); the later composed eight types of resistance: system blaming, victims blaming, problems with treatment alliance, social justification, hopelessness, isolation, psychological reactance, and passive reactance. Both of the instruments were with well reliability and validity. Descriptive statistics and ANOVA were performed. All of 272 participants, age under 25 were 18(6.6%), 25-39 were 133(48.9%), 40-54 were 102(37.5%), and age over 55 were 19(7.0%); college level and above were 53(19.5%), high school level were 110(40.4%), and under high school level were 109(40.1%); first offended were 117(43.0%), and recidivist were 23(8.5%). Further deleting data with missing values and invalid questionnaires, SO with stage of change on PC were 43(18.9%), C were 109(47.8%), A were 70(30.7%), and on M were 6(2.6%). One-way ANOVA showed significant differences on every kind of resistances, excepting isolation and passive reactance. Post-hoc analysis showed that SO with different stages had their main resistance. There are two contributions to the present study. First, this study provided a clinical and theoretical measurement of evaluation that was never used in the past. Second, this study used an evidence-based methodology to prove a clinical perspective differed from the past, suggesting that resistances to treatment on SO appear the whole therapeutic process, when SO progress into the next stage of change, clinicians have to deal with their main resistance for working through the therapy.

Keywords: resistance, sexual offenders treatment program (SOTP), motivation for change, prisoned sexual offender

Procedia PDF Downloads 242
1020 Applicability of Linearized Model of Synchronous Generator for Power System Stability Analysis

Authors: J. Ritonja, B. Grcar

Abstract:

For the synchronous generator simulation and analysis and for the power system stabilizer design and synthesis a mathematical model of synchronous generator is needed. The model has to accurately describe dynamics of oscillations, while at the same time has to be transparent enough for an analysis and sufficiently simplified for design of control system. To study the oscillations of the synchronous generator against to the rest of the power system, the model of the synchronous machine connected to an infinite bus through a transmission line having resistance and inductance is needed. In this paper, the linearized reduced order dynamic model of the synchronous generator connected to the infinite bus is presented and analysed in details. This model accurately describes dynamics of the synchronous generator only in a small vicinity of an equilibrium state. With the digression from the selected equilibrium point the accuracy of this model is decreasing considerably. In this paper, the equations’ descriptions and the parameters’ determinations for the linearized reduced order mathematical model of the synchronous generator are explained and summarized and represent the useful origin for works in the areas of synchronous generators’ dynamic behaviour analysis and synchronous generator’s control systems design and synthesis. The main contribution of this paper represents the detailed analysis of the accuracy of the linearized reduced order dynamic model in the entire synchronous generator’s operating range. Borders of the areas where the linearized reduced order mathematical model represents accurate description of the synchronous generator’s dynamics are determined with the systemic numerical analysis. The thorough eigenvalue analysis of the linearized models in the entire operating range is performed. In the paper, the parameters of the linearized reduced order dynamic model of the laboratory salient poles synchronous generator were determined and used for the analysis. The theoretical conclusions were confirmed with the agreement of experimental and simulation results.

Keywords: eigenvalue analysis, mathematical model, power system stability, synchronous generator

Procedia PDF Downloads 240
1019 Mobile Application Interventions in Positive Psychology: Current Status and Recommendations for Effective App Design

Authors: Gus Salazar, Jeremy Bekker, Lauren Linford, Jared Warren

Abstract:

Positive psychology practices allow for its principles to be applied to all people, regardless of their current level of functioning. To increase the dissemination of these practices, interventions are being adapted for use with digital technology, such as mobile apps. However, the research regarding positive psychology mobile app interventions is still in its infancy. In an effort to facilitate progress in this important area, we 1) conducted a qualitative review to summarize the current state of the positive psychology mobile app literature and 2) developed research-supported recommendations for positive psychology app development to maximize behavior change. In our literature review, we found that while positive psychology apps varied widely in content and purpose, there was a near-complete lack of research supporting their effectiveness. Most apps provided no rationale for the behavioral change techniques (BCTs) they employed in their app, and most did not develop their app with specific theoretical frameworks or design models in mind. Given this problem, we recommended four steps for effective positive psychology app design. First, developers must establish their app in a research-supported theory of change. Second, researchers must select appropriate behavioral change techniques which are consistent with their app’s goals. Third, researchers must leverage effective design principles. These steps will help mobile applications use data-driven methods for encouraging behavior change in their users. Lastly, we discuss directions for future research. In particular, researchers must investigate the effectiveness of various BCTs in positive psychology interventions. Although there is some research on this point, we do not yet clearly understand the mechanisms within the apps that lead to behavior change. Additionally, app developers must also provide data on the effectiveness of their mobile apps. As developers follow these steps for effective app development and as researchers continue to investigate what makes these apps most effective, we will provide millions of people in need with access to research-based mental health resources.

Keywords: behavioral change techniques, mobile app, mobile intervention, positive psychology

Procedia PDF Downloads 223
1018 Experimental and Theoretical Study on Flexural Behaviors of Reinforced Concrete Cement (RCC) Beams by Using Carbonfiber Reinforcedpolymer (CFRP) Laminate as Retrofitting and Rehabilitation Method

Authors: Fils Olivier Kamanzi

Abstract:

This research Paper shows that materials CFRP were used to rehabilitate 9 Beams and retrofitting of 9 Beams with size (125x250x2300) mm each for M50 grade of concrete with 20% of Volume of Cement replaced by GGBS as a mineral Admixture. Superplasticizer (ForscoConplast SP430) used to reduce the water-cement ratio and maintaining good workability of fresh concrete (Slump test 57mm). Concrete Mix ratio 1:1.56:2.66 with a water-cement ratio of 0.31(ACI codebooks). A sample of 6cubes sized (150X150X150) mm, 6cylinders sized (150ФX300H) mm and 6Prisms sized (100X100X500) mm were cast, cured, and tested for 7,14&28days by compressive, tensile and flexure test; finally, mix design reaches the compressive strength of 59.84N/mm2. 21 Beams were cast and cured for up to 28 days, 3Beams were tested by a two-point loading machine as Control beams. 9 Beams were distressed in flexure by adopting failure up to final Yielding point under two-point loading conditions by taking 90% off Ultimate load. Three sets, each composed of three distressed beams, were rehabilitated by using CFRP sheets, one, two & three layers, respectively, and after being retested up to failure mode. Another three sets were freshly retrofitted also by using CFRP sheets one, two & three layers, respectively, and being tested by a two-point load method of compression strength testing machine. The aim of this study is to determine the flexural Strength & behaviors of repaired and retrofitted Beams by CFRP sheets for gaining good strength and considering economic aspects. The results show that rehabilitated beams increase its strength 47 %, 78 % & 89 %, respectively, to thickness of CFRP sheets and 41%, 51 %& 68 %, respectively too, for retrofitted Beams. The conclusion is that three layers of CFRP sheets are the best applicable in repairing and retrofitting the bonded beams method.

Keywords: retrofitting, rehabilitation, cfrp, rcc beam, flexural strength and behaviors, ggbs, and epoxy resin

Procedia PDF Downloads 103
1017 Using Electronic Portfolio to Promote English Speaking Ability of EFL Undergraduate Students

Authors: Jiraporn Lao-Un, Dararat Khampusaen

Abstract:

Lack of exposure to English language in the authentic English setting naturally leads to a lack of fluency in the language. As a result, Thai EFL learners are struggling in meeting with the communication 'can do' descriptors of the Common European Framework of References (CEFR) required by the Ministry of Education. This initial phase of the ongoing study, employing the e-portfolio to promote the English speaking ability, probed into the effects of the use of e-portfolio on Thai EFL nursing students' speaking ability. Also, their opinions towards the use of e-portfolio to enhance their speaking ability were investigated. The participants were 44 undergraduate nursing students at a Thai College of Nursing. The participants undertook four lessons to promote their communication skills according to the CEFR criteria. Throughout the semester, the participants videotaped themselves while completing the four speaking tasks. The videos were then uploaded onto the e-portfolio website where the researcher provided them with the feedbacks. The video records were analyzed by the speaking rubric designed according to the CEFR 'can do' descriptors. Also, students were required to record self-reflections in video format and upload onto the same URL Students' oral self-reflections were coded to find out the perceptions towards the use of the e-portfolio in promoting their speaking ability. The results from the two research instruments suggested the effectiveness of the tool on improving speaking ability, learner autonomy and media literacy skills. In addition, the oral reflection videos revealed positive opinion towards the tool. The discussion offers the current status of English speaking ability among Thai EFL students. This reveals the gaps between the EFL speaking ability and the CEFR ‘can do’ descriptors. In addition, the author raises the light on integration of the 21st century IT tool to enhance these students’ speaking ability. Lastly, the theoretical implications and recommendation for further study in integrating electronic tools to promote language skills in the EFL context are offered for further research.

Keywords: EFL communication, EFL speaking, English communication, E-learning, E-portfolio, speaking ability, Thai EFL learners

Procedia PDF Downloads 157
1016 Feasibility Study on Developing and Enhancing of Flood Forecasting and Warning Systems in Thailand

Authors: Sitarrine Thongpussawal, Dasarath Jayasuriya, Thanaroj Woraratprasert, Sakawtree Prajamwong

Abstract:

Thailand grapples with recurrent floods causing substantial repercussions on its economy, society, and environment. In 2021, the economic toll of these floods amounted to an estimated 53,282 million baht, primarily impacting the agricultural sector. The existing flood monitoring system in Thailand suffers from inaccuracies and insufficient information, resulting in delayed warnings and ineffective communication to the public. The Office of the National Water Resources (OWNR) is tasked with developing and integrating data and information systems for efficient water resources management, yet faces challenges in monitoring accuracy, forecasting, and timely warnings. This study endeavors to evaluate the viability of enhancing Thailand's Flood Forecasting and Warning (FFW) systems. Additionally, it aims to formulate a comprehensive work package grounded in international best practices to enhance the country's FFW systems. Employing qualitative research methodologies, the study conducted in-depth interviews and focus groups with pertinent agencies. Data analysis involved techniques like note-taking and document analysis. The study substantiates the feasibility of developing and enhancing FFW systems in Thailand. Implementation of international best practices can augment the precision of flood forecasting and warning systems, empowering local agencies and residents in high-risk areas to prepare proactively, thereby minimizing the adverse impact of floods on lives and property. This research underscores that Thailand can feasibly advance its FFW systems by adopting international best practices, enhancing accuracy, and improving preparedness. Consequently, the study enriches the theoretical understanding of flood forecasting and warning systems and furnishes valuable recommendations for their enhancement in Thailand.

Keywords: flooding, forecasting, warning, monitoring, communication, Thailand

Procedia PDF Downloads 57
1015 Integrating Human Rights into Countering Violent Extremism: A Comparative Analysis of Women Without Borders and Hedayah Initiatives

Authors: Portia Muehlbauer

Abstract:

This paper examines the evolving landscape of preventing and countering violent extremism (PCVE) by delving into the growing importance of integrating human rights principles into violence prevention strategies on the local, community level. This study sheds light on the underlying theoretical frameworks of violent extremism and the influence of gender while investigating the intersection between human rights preservation and violent extremism prevention. To gain practical insight, the research focuses on two prominent international non-governmental organizations, Women without Borders (WwB) and Hedayah, and their distinct PCVE initiatives. WwB adopts a gender-sensitive approach, implementing parental education programs that empower mothers in at-risk communities to prevent the spread of violent extremism. In contrast, Hedayah takes an indirect route, employing capacity building programs that enhance the capabilities of educators, social workers, and psychologists in early intervention, rehabilitation and reintegration efforts. Qualitative data for this comparative analysis was collected through an extensive four-month internship at WwB during the fall of 2020, a three-month internship at Hedayah in the spring of 2021, a thought-provoking semi-structured interview with the executive director of WwB, personal field notes, and a comprehensive discourse analysis of the prevailing literature on human rights considerations in PCVE practices. This study examines the merits and challenges of integrating human rights into PCVE programming through the lens of both organizations, WwB and Hedayah. The findings of this study will inform policymakers, practitioners, and researchers on the intricate relationship between human rights protection and effective PCVE strategies.

Keywords: preventing and countering violent extremism, human rights, counterterrorism, peacebuilding, capacity building programs, gender studies

Procedia PDF Downloads 57
1014 The Investigation of Oil Price Shocks by Using a Dynamic Stochastic General Equilibrium: The Case of Iran

Authors: Bahram Fathi, Karim Alizadeh, Azam Mohammadbagheri

Abstract:

The aim of this paper is to investigate the role of oil price shocks in explaining business cycles in Iran using a dynamic stochastic general equilibrium approach. This model incorporates both productivity and oil revenue shocks. The results indicate that productivity shocks are relatively more important to business cycles than oil shocks. The model with two shocks produces different values for volatility, but these values have the same ranking as that of the actual data for most variables. In addition, the actual data are close to the ratio of standard deviations to the output obtained from the model with two shocks. The results indicate that productivity shocks are relatively more important to business cycles than the oil shocks. The model with only a productivity shock produces the most similar figures in term of volatility magnitude to that of the actual data. Next, we use the Impulse Response Functions (IRF) to evaluate the capability of the model. The IRF shows no effect of an oil shock on the capital stocks and on labor hours, which is a feature of the model. When the log-linearized system of equations is solved numerically, investment and labor hours were not found to be functions of the oil shock. This research recommends using different techniques to compare the model’s robustness. One method by which to do this is to have all decision variables as a function of the oil shock by inducing the stationary to the model differently. Another method is to impose a bond adjustment cost. This study intends to fill that gap. To achieve this objective, we derive a DSGE model that allows for the world oil price and productivity shocks. Second, we calibrate the model to the Iran economy. Next, we compare the moments from the theoretical model with both single and multiple shocks with that obtained from the actual data to see the extent to which business cycles in Iran can be explained by total oil revenue shock. Then, we use an impulse response function to evaluate the role of world oil price shocks. Finally, I present implications of the findings and interpretations in accordance with economic theory.

Keywords: oil price, shocks, dynamic stochastic general equilibrium, Iran

Procedia PDF Downloads 434
1013 Workplace Development Programmes for Small and Medium-Sized Enterprises in Europe and Singapore: A Conceptual Study

Authors: Zhan Jie How

Abstract:

With the heightened awareness of workplace learning and its impact on improving organizational performance and developing employee competence, governments and corporations around the world are forced to intensify their cooperation to establish national workplace development programmes to guide these corporations in fostering engaging and collaborative workplace learning cultures. This conceptual paper aims to conduct a comparative study of existing workplace development programmes for small and medium-sized enterprises (SMEs) in Europe and Singapore, focusing primarily on the Swedish Production Leap, Finnish TEKES Liideri Programme, and Singapore SkillsFuture SME Mentors Programme. The study carries out a systematic review of the three workplace development programmes to examine the roles of external mentors or coaches in influencing the design and implementation of workplace learning strategies and practices in SMEs. Organizational, personal and external factors that promote or inhibit effective workplace mentorship are also scrutinized, culminating in a critical comparison and evaluation of the strengths and weaknesses of the aforementioned programmes. Based on the findings from the review and analyses, a heuristic conceptual framework is developed to illustrate the complex interrelationships among external workplace development programmes, internal learning and development initiatives instituted by the organization’s higher management, and employees' continuous learning activities at the workplace. The framework also includes a set of guiding principles that can be used as the basis for internal mediation between the competing perspectives of mentors and mentees (employers and employees of the organization) regarding workplace learning conditions, practices and their intended impact on the organization. The conceptual study provides a theoretical blueprint for future empirical research on organizational workplace learning and the impact of government-initiated workplace development programmes.

Keywords: employee competence, mentorship, organizational performance, workplace development programme, workplace learning culture

Procedia PDF Downloads 136
1012 A Scoping Review of Psychosocial Interventions for the Survivors and/or Victims of Intimate Partner Violence in Low- and Middle-Income Countries

Authors: Mukondi Nethavhakone

Abstract:

The high prevalence of violence against women is a global public health problem. Our societies have become dangerous places for women. Women during their child-bearing ages are at a higher risk of experiencing emotional, physical, and sexual violence. What makes it more concerning is that these violent acts are perpetrated by family members or partners, or ex-partners. Intimate Partner Violence (IPV) is associated with long-lasting physical, reproductive, sexual, mental, and maternal health implications. Expectedly women’s mental health would dimmish as a result of experiencing IPV. The burden of violence against women is seen to be heavier in low- and middle-income countries (LMICs) compared to the rest of the world. Countries have committed to eliminating all forms of violence against women through the sustainable development goal, aiming to see changes by the year 2030. As such, various countries have implemented psychosocial interventions of different levels of impact. However, little is known, especially in low- and middle-income countries, with regard to the potential of psychosocial interventions for IPV to improve the mental health outcomes for the survivors and/or victims of IPV. Analysing the risk for IPV through a social-ecological theoretical approach, low- and middle-income countries still readdressing gender inequality which is the cause of intimate partner violence. That is why it is taking time for these countries to shift psychosocial interventions to focus more on the improvement of the mental health of the survivors. It is, therefore, against this backdrop that the researcher intends to undertake a scoping review to understand the nature and characteristics of psychosocial interventions that have been implemented in low- and middle-income countries. With the findings from the scoping review, the researcher aims to develop a conceptual framework that may be a useful resource for healthcare practitioners and researchers in low- and middle-income countries. As this area of research has not been thoroughly reviewed, the results from this scoping will determine whether a systematic review will be justifiable. Additionally, the researcher will identify gaps and opportunities for future research in this area.

Keywords: mental health improvement, psychosocial interventions, intimate partner violence, LMICs

Procedia PDF Downloads 128
1011 Electrophoretic Light Scattering Based on Total Internal Reflection as a Promising Diagnostic Method

Authors: Ekaterina A. Savchenko, Elena N. Velichko, Evgenii T. Aksenov

Abstract:

The development of pathological processes, such as cardiovascular and oncological diseases, are accompanied by changes in molecular parameters in cells, tissues, and serum. The study of the behavior of protein molecules in solutions is of primarily importance for diagnosis of such diseases. Various physical and chemical methods are used to study molecular systems. With the advent of the laser and advances in electronics, optical methods, such as scanning electron microscopy, sedimentation analysis, nephelometry, static and dynamic light scattering, have become the most universal, informative and accurate tools for estimating the parameters of nanoscale objects. The electrophoretic light scattering is the most effective technique. It has a high potential in the study of biological solutions and their properties. This technique allows one to investigate the processes of aggregation and dissociation of different macromolecules and obtain information on their shapes, sizes and molecular weights. Electrophoretic light scattering is an analytical method for registration of the motion of microscopic particles under the influence of an electric field by means of quasi-elastic light scattering in a homogeneous solution with a subsequent registration of the spectral or correlation characteristics of the light scattered from a moving object. We modified the technique by using the regime of total internal reflection with the aim of increasing its sensitivity and reducing the volume of the sample to be investigated, which opens the prospects of automating simultaneous multiparameter measurements. In addition, the method of total internal reflection allows one to study biological fluids on the level of single molecules, which also makes it possible to increase the sensitivity and the informativeness of the results because the data obtained from an individual molecule is not averaged over an ensemble, which is important in the study of bimolecular fluids. To our best knowledge the study of electrophoretic light scattering in the regime of total internal reflection is proposed for the first time, latex microspheres 1 μm in size were used as test objects. In this study, the total internal reflection regime was realized on a quartz prism where the free electrophoresis regime was set. A semiconductor laser with a wavelength of 655 nm was used as a radiation source, and the light scattering signal was registered by a pin-diode. Then the signal from a photodetector was transmitted to a digital oscilloscope and to a computer. The autocorrelation functions and the fast Fourier transform in the regime of Brownian motion and under the action of the field were calculated to obtain the parameters of the object investigated. The main result of the study was the dependence of the autocorrelation function on the concentration of microspheres and the applied field magnitude. The effect of heating became more pronounced with increasing sample concentrations and electric field. The results obtained in our study demonstrated the applicability of the method for the examination of liquid solutions, including biological fluids.

Keywords: light scattering, electrophoretic light scattering, electrophoresis, total internal reflection

Procedia PDF Downloads 211
1010 Diagnostic Yield of CT PA and Value of Pre Test Assessments in Predicting the Probability of Pulmonary Embolism

Authors: Shanza Akram, Sameen Toor, Heba Harb Abu Alkass, Zainab Abdulsalam Altaha, Sara Taha Abdulla, Saleem Imran

Abstract:

Acute pulmonary embolism (PE) is a common disease and can be fatal. The clinical presentation is variable and nonspecific, making accurate diagnosis difficult. Testing patients with suspected acute PE has increased dramatically. However, the overuse of some tests, particularly CT and D-dimer measurement, may not improve care while potentially leading to patient harm and unnecessary expense. CTPA is the investigation of choice for PE. Its easy availability, accuracy and ability to provide alternative diagnosis has lowered the threshold for performing it, resulting in its overuse. Guidelines have recommended the use of clinical pretest probability tools such as ‘Wells score’ to assess risk of suspected PE. Unfortunately, implementation of guidelines in clinical practice is inconsistent. This has led to low risk patients being subjected to unnecessary imaging, exposure to radiation and possible contrast related complications. Aim: To study the diagnostic yield of CT PA, clinical pretest probability of patients according to wells score and to determine whether or not there was an overuse of CTPA in our service. Methods: CT scans done on patients with suspected P.E in our hospital from 1st January 2014 to 31st December 2014 were retrospectively reviewed. Medical records were reviewed to study demographics, clinical presentation, final diagnosis, and to establish if Wells score and D-Dimer were used correctly in predicting the probability of PE and the need for subsequent CTPA. Results: 100 patients (51male) underwent CT PA in the time period. Mean age was 57 years (24-91 years). Majority of patients presented with shortness of breath (52%). Other presenting symptoms included chest pain 34%, palpitations 6%, collapse 5% and haemoptysis 5%. D Dimer test was done in 69%. Overall Wells score was low (<2) in 28 %, moderate (>2 - < 6) in 47% and high (> 6) in 15% of patients. Wells score was documented in medical notes of only 20% patients. PE was confirmed in 12% (8 male) patients. 4 had bilateral PE’s. In high-risk group (Wells > 6) (n=15), there were 5 diagnosed PEs. In moderate risk group (Wells >2 - < 6) (n=47), there were 6 and in low risk group (Wells <2) (n=28), one case of PE was confirmed. CT scans negative for PE showed pleural effusion in 30, Consolidation in 20, atelactasis in 15 and pulmonary nodule in 4 patients. 31 scans were completely normal. Conclusion: Yield of CT for pulmonary embolism was low in our cohort at 12%. A significant number of our patients who underwent CT PA had low Wells score. This suggests that CT PA is over utilized in our institution. Wells score was poorly documented in medical notes. CT-PA was able to detect alternative pulmonary abnormalities explaining the patient's clinical presentation. CT-PA requires concomitant pretest clinical probability assessment to be an effective diagnostic tool for confirming or excluding PE. . Clinicians should use validated clinical prediction rules to estimate pretest probability in patients in whom acute PE is being considered. Combining Wells scores with clinical and laboratory assessment may reduce the need for CTPA.

Keywords: CT PA, D dimer, pulmonary embolism, wells score

Procedia PDF Downloads 229
1009 A Multinomial Logistic Regression Analysis of Factors Influencing Couples' Fertility Preferences in Kenya

Authors: Naomi W. Maina

Abstract:

Fertility preference is a subject of great significance in developing countries. Studies reveal that the preferences of fertility are actually significant in determining the society’s fertility levels because the fertility behavior of the future has a high likelihood of falling under the effect of currently observed fertility inclinations. The objective of this study was to establish the factors associated with fertility preference amongst couples in Kenya by fitting a multinomial logistic regression model against 5,265 couple data obtained from Kenya demographic health survey 2014. Results revealed that the type of place of residence, the region of residence, age and spousal age gap significantly influence desire for additional children among couples in Kenya. There was the notable high likelihood of couples living in rural settlements having similar fertility preference compared to those living in urban settlements. Moreover, geographical disparities such as in northern Kenya revealed significant differences in a couples desire to have additional children compared to Nairobi. The odds of a couple’s desire for additional children were further observed to vary dependent on either the wife or husbands age and to a large extent the spousal age gap. Evidenced from the study, was the fact that as spousal age gap increases, the desire for more children amongst couples decreases. Insights derived from this study would be attractive to demographers, health practitioners, policymakers, and non-governmental organizations implementing fertility related interventions in Kenya among other stakeholders. Moreover, with the adoption of devolution, there is a clear need for adoption of population policies that are County specific as opposed to a national population policy as is the current practice in Kenya. Additionally, researchers or students who have little understanding in the application of multinomial logistic regression, both theoretical understanding and practical analysis in SPSS as well as application on real datasets, will find this article useful.

Keywords: couples' desire, fertility, fertility preference, multinomial regression analysis

Procedia PDF Downloads 180
1008 Family Quality of Life in the Context of Pediatric Sickle Cell Disease in Oman

Authors: Wafa Al Jabri

Abstract:

Sickle cell disease (SCD) is a genetic blood disorder that is characterized by a severe painful crisis. SCD among children requires long term dependencies and high caregiving demands that increase the overall family burdens. It is, therefore, essential to examine, support, and promote the well-being of families of children with SCD. Although there has been considerable progress in the international research on family quality of life (FQOL) in recent years; however, research in this field is relatively recent and diverse. Oman is a country in which family quality of life has definitely been under-researched. Therefore, the purpose of the study is to describe the FQOL in families of children with SCD in Oman. The study will also examine the relationships between child, mother, and family-related factors that may influence the overall FQOL. Theoretical Framework: The study is guided by the unified theory of family quality of life to help in understanding the concept of FQOL and the factors that shape it. Method:A convenience sample of 98 mothers of children with SCD will be recruited from the pediatric hematology clinic at Sultan Qaboos University Hospital in Oman to participate in this descriptive, cross sectional, correlational study. Data will be obtained using a self-administered questionnaire that includes child and mother socio-demographic data, questions about the number of visits and admissions to health care facilities for vaso- occlusive crises (VOCs), the Perceived Stress Scale-10, and the Beachcenter-FQOL scale. Anticipated Results: It is expected to find an association among frequency of VOCs, mother’s perceived stress level, and FQOL in families of children with SCD in Oman. Family type, socio-economic status, and number of SCD children in the family are also expected to influence the overall FQOL. Conclusion: The findings of the study might be pivotal in designing and implementing tailored family-based interventions to improve families’ wellbeing.

Keywords: family quality of life, sickle cell disaes, children, family well-being

Procedia PDF Downloads 133
1007 Discourse Analysis and Semiotic Researches: Using Michael Halliday's Sociosemiotic Theory

Authors: Deyu Yuan

Abstract:

Discourse analysis as an interdisciplinary approach has more than 60-years-history since it was first named by Zellig Harris in 'Discourse Analysis' on Language in 1952. Ferdinand de Saussure differentiated the 'parole' from the 'langue' that established the principle of focusing on language but not speech. So the rising of discourse analysis can be seen as a discursive turn for the entire language research that closely related to the theory of Speech act. Critical discourse analysis becomes the mainstream of contemporary language research through drawing upon M. A. K. Halliday's socio-semiotic theory and Foucault, Barthes, Bourdieu's views on the sign, discourse, and ideology. So in contrast to general semiotics, social semiotics mainly focuses on parole and the application of semiotic theories to some applicable fields. The article attempts to discuss this applicable sociosemiotics and show the features of it that differ from the Saussurian and Peircian semiotics in four aspects: 1) the sign system is about meaning-generation resource in the social context; 2) the sign system conforms to social and cultural changes with the form of metaphor and connotation; 3) sociosemiotics concerns about five applicable principles including the personal authority principle, non-personal authority principle, consistency principle, model demonstration principle, the expertise principle to deepen specific communication; 4) the study of symbolic functions is targeted to the characteristics of ideational, interpersonal and interactional function in social communication process. Then the paper describes six features which characterize this sociosemiotics as applicable semiotics: social, systematic, usable interdisciplinary, dynamic, and multi-modal characteristics. Thirdly, the paper explores the multi-modal choices of sociosemiotics in the respects of genre, discourse, and style. Finally, the paper discusses the relationship between theory and practice in social semiotics and proposes a relatively comprehensive theoretical framework for social semiotics as applicable semiotics.

Keywords: discourse analysis, sociosemiotics, pragmatics, ideology

Procedia PDF Downloads 344
1006 Pre-Experimental Research to Investigate the Retention of Basic and Advanced Life Support Measures Knowledge and Skills by Qualified Nurses Following a Course in Professional Development in a Tertiary Teaching Hospital

Authors: Ram Sharan Mehta, Gayanandra Malla, Anita Gurung, Anu Aryal, Divya Labh, Hricha Neupane

Abstract:

Objectives: Lack of resuscitation skills of nurses and doctors in basic life support (BLS) and advanced life support (ALS) has been identified as a contributing factor to poor outcomes of cardiac arrest victims. The objective of this study was to examine retention of life support measures (BLS/ALS) knowledge and skills of nurses following education intervention programme. Materials and Methods: Pre-experimental research design was used to conduct the study among the nurses working in medical units of B.P Koirala Institute of Health Sciences, where CPR is very commonly performed. Using convenient sampling technique total of 20 nurses agreed to participate and give consent were included in the study. The theoretical, demonstration and re-demonstration were arranged involving the trained doctors and nurses during the three hours educational session. Post-test was carried out after two week of education intervention programme. The 2010 BLS & ALS guidelines were used as guide for the study contents. The collected data were analyzed using SPSS-15 software. Results: It was found that there is significant increase in knowledge after education intervention in the components of life support measures (BLS/ALS) i.e. ratio of chest compression to ventilation in BLS (P=0.001), correct sequence of CPR (p <0.001), rate of chest compression in ALS (P=0.001), the depth of chest compression in adult CPR (p<0.001), and position of chest compression in CPR (P=0.016). Nurses were well appreciated the programme and request to continue in future for all the nurses. Conclusions: At recent BLS/ALS courses (2010), a significant number of nurses remain without any such training. Action is needed to ensure all nurses receive BLS training and practice this skill regularly in order to retain their knowledge.

Keywords: pre-experimental, basic and advance life support, nurses, sampling technique

Procedia PDF Downloads 253
1005 An Evolutionary Approach for Automated Optimization and Design of Vivaldi Antennas

Authors: Sahithi Yarlagadda

Abstract:

The design of antenna is constrained by mathematical and geometrical parameters. Though there are diverse antenna structures with wide range of feeds yet, there are many geometries to be tried, which cannot be customized into predefined computational methods. The antenna design and optimization qualify to apply evolutionary algorithmic approach since the antenna parameters weights dependent on geometric characteristics directly. The evolutionary algorithm can be explained simply for a given quality function to be maximized. We can randomly create a set of candidate solutions, elements of the function's domain, and apply the quality function as an abstract fitness measure. Based on this fitness, some of the better candidates are chosen to seed the next generation by applying recombination and permutation to them. In conventional approach, the quality function is unaltered for any iteration. But the antenna parameters and geometries are wide to fit into single function. So, the weight coefficients are obtained for all possible antenna electrical parameters and geometries; the variation is learnt by mining the data obtained for an optimized algorithm. The weight and covariant coefficients of corresponding parameters are logged for learning and future use as datasets. This paper drafts an approach to obtain the requirements to study and methodize the evolutionary approach to automated antenna design for our past work on Vivaldi antenna as test candidate. The antenna parameters like gain, directivity, etc. are directly caged by geometries, materials, and dimensions. The design equations are to be noted here and valuated for all possible conditions to get maxima and minima for given frequency band. The boundary conditions are thus obtained prior to implementation, easing the optimization. The implementation mainly aimed to study the practical computational, processing, and design complexities that incur while simulations. HFSS is chosen for simulations and results. MATLAB is used to generate the computations, combinations, and data logging. MATLAB is also used to apply machine learning algorithms and plotting the data to design the algorithm. The number of combinations is to be tested manually, so HFSS API is used to call HFSS functions from MATLAB itself. MATLAB parallel processing tool box is used to run multiple simulations in parallel. The aim is to develop an add-in to antenna design software like HFSS, CSTor, a standalone application to optimize pre-identified common parameters of wide range of antennas available. In this paper, we have used MATLAB to calculate Vivaldi antenna parameters like slot line characteristic impedance, impedance of stripline, slot line width, flare aperture size, dielectric and K means, and Hamming window are applied to obtain the best test parameters. HFSS API is used to calculate the radiation, bandwidth, directivity, and efficiency, and data is logged for applying the Evolutionary genetic algorithm in MATLAB. The paper demonstrates the computational weights and Machine Learning approach for automated antenna optimizing for Vivaldi antenna.

Keywords: machine learning, Vivaldi, evolutionary algorithm, genetic algorithm

Procedia PDF Downloads 104