Search results for: water based paints

Authors: Garzon V., Bustos R., Salvador J. P., Marco M. P., Pinacho D. G.

Abstract:

Bacterial resistance to antimicrobial treatment has increased significantly in recent years, making it a public health problem. Large numbers of bacteria are resistant to all or nearly all known antimicrobials, creating the need for the development of new types of antimicrobials or the use of “last line” antimicrobial drug therapies for the treatment of multi-resistant bacteria. Some of the chemical groups of antimicrobials most used for the treatment of infections caused by multiresistant bacteria in the clinic are Glycopeptide (Vancomycin), Polymyxin (Colistin), Lipopeptide (Daptomycin) and Carbapenem (Meropenem). Molecules that require therapeutic drug monitoring (TDM). Due to the above, a methodology based on nanobiotechnology based on an optical and electrochemical biosensor is being developed, which allows the evaluation of the plasmatic levels of some antimicrobials such as glycopeptide, polymyxin, lipopeptide and carbapenem quickly, at a low cost, with a high specificity and sensitivity and that can be implemented in the future in public and private health hospitals. For this, the project was divided into five steps i) Design of specific anti-drug antibodies, produced in rabbits for each of the types of antimicrobials, evaluating the results by means of an immunoassay analysis (ELISA); ii) quantification by means of an electrochemical biosensor that allows quantification with high sensitivity and selectivity of the reference antimicrobials; iii) Comparison of antimicrobial quantification with an optical type biosensor; iv) Validation of the methodologies used with biosensor by means of an immunoassay. Finding as a result that it is possible to quantify antibiotics by means of the optical and electrochemical biosensor at concentrations on average of 1,000ng/mL, the antibodies being sensitive and specific for each of the antibiotic molecules, results that were compared with immunoassays and HPLC chromatography. Thus, contributing to the safe use of these drugs commonly used in clinical practice and new antimicrobial drugs.

Keywords: antibiotics, electrochemical biosensor, optical biosensor, therapeutic drug monitoring

Procedia PDF Downloads 73

Authors: Andreas Hirseland, Lukas Kerschbaumer

Abstract:

In Germany, during the past years there constantly are about one million long term unemployed who did not benefit from the prospering labor market while most short term unemployed did. Instead, they are continuously dependent on welfare and sometimes precarious short-term employment, experiencing work poverty. Long term unemployment thus turns into a main obstacle to regular employment, especially if accompanied by other impediments such as low level education (school/vocational), poor health (especially chronical illness), advanced age (older than fifty), immigrant status, motherhood or engagement in care for other relatives. Almost two thirds of all welfare recipients have multiple impediments which hinder a successful transition from welfare back to sustainable and sufficient employment. Hiring them is often considered as an investment too risky for employers. Therefore formal application schemes based on formal qualification certificates and vocational biographies might reduce employers’ risks but at the same time are not helpful for long-term unemployed and welfare recipients. The panel survey ‘Labor market and social security’ (PASS; ~15,000 respondents in ~10,000 households), carried out by the Institute of Employment Research (the research institute of the German Federal Labor Agency), shows that their chance to get back to work tends to fall to nil. Only 66 cases of such unlikely transitions could be observed. In a sequential explanatory mixed-method study, the very scarce ‘success stories’ of unlikely transitions from long term unemployment to work were explored by qualitative inquiry – in-depth interviews with a focus on biography accompanied by qualitative network techniques in order to get a more detailed insight of relevant actors involved in the processes which promote the transition from being a welfare recipient to work. There is strong evidence that sustainable transitions are influenced by biographical resources like habits of network use, a set of informal skills and particularly a resilient way of dealing with obstacles, combined with contextual factors rather than by job-placement procedures promoted by Job-Centers according to activation rules or by following formal paths of application. On the employer’s side small and medium-sized enterprises are often found to give job opportunities to a wider variety of applicants, often based on a slow but steadily increasing relationship leading to employment. According to these results it is possible to show and discuss some limitations of (German) activation policies targeting welfare dependency and long-term unemployment. Based on these findings, indications for more supportive small scale measures in the field of labor-market policies are suggested to help long-term unemployed with multiple impediments to overcome their situation.

Keywords: against-all-odds, economic sociology, long-term unemployment, mixed-methods

Procedia PDF Downloads 234

Authors: Łukasz Bis

Abstract:

The author is going to discuss virtual reality and its importance for new didactic methods. It has been known for years that experience-based education gives much better results in terms of long-term memory than theoretical study. However, practice is expensive - virtual reality allows the use of an empirical approach to learning, with minimized production costs. The author defines what makes a given VR experience appropriate (adequate) for the didactic and cognitive process. The article is a kind of a list of guidelines and their importance for the VR experience under development.

Keywords: virtual reality, education, universal design, guideline

Procedia PDF Downloads 99

Authors: Emrehan Ozcan, Dilek Beyazlı

Abstract:

The development of tourism depends on an accurate planning approach as well as on the right planning process. This dependency is also a key factor in ensuring sustainability of tourism. The types of tourism, social expectations, planning practice, the socio-economic and the cultural structure of the region are determinants of planning approaches for tourism development. The tourism plans prepared for the historic city centers are usually based on the revitalization of cultural and historical values. The preservation and development of the tourism potentials of the historic city centers are important for providing an economic contribution to the locality, creating livable solutions for local residents and also the sustainability of tourism. This research is about experiencing and discussing a planning approach that will provide tourism development based on historical and cultural values. Historical and cultural values in the historical city center of Trabzon -which has a settlement history of approximately 4000 years, is located on the Black Sea coast of Turkey- wear out over years and lose their tourism potential. A planning study has been experienced with strategic spatial planning approach for Trabzon, which has not done a tourism-oriented planning study until now. The stages of the planning process provided by strategic spatial planning approach are an assessment of the current situation; vision, strategies, and actions; action planning; designing and implementation of actions and monitoring-evaluation. In the discussion section, the advantages, planning process, methods and techniques of the approach are discussed for the possibilities and constraints in terms of tourism planning. In this context, it is aimed to put forth tourism planning process, stages, and implementation tools within the scope of strategic spatial planning approach by comparing approaches used in the tourism-oriented/priority planning of historical city centers. Suggestions on the position and effect of the preferred planning approach in the existing spatial planning practice are the outputs of the study.

Keywords: cultural heritage, tourism oriented planning, Trabzon, strategic spatial Planning

Procedia PDF Downloads 251

Authors: Ana L. Martins, Rita S. Saraiva, João C. Ferreira

Abstract:

Much effort has been placed on the assessment of perceived service quality. Several models can be found in literature, but these are mainly focused on business-to-consumer (B2C) relationships. Literature on how to assess perceived quality in business-to-business (B2B) contexts is scarce both conceptually and in terms of its application. This research aims at filling this gap in literature by applying INDSERV to a case study situation. Under this scope, this research aims at analyzing the adequacy of the proposed assessment tool to other context besides the one where it was developed and by doing so analyzing the perceive quality of the advertisement service provided by a specific television network to its B2B customers. The INDSERV scale was adopted and applied to a sample of 33 clients, via questionnaires adapted to interviews. Data was collected in person or phone. Both quantitative and qualitative data collection was performed. Qualitative data analysis followed content analysis protocol. Quantitative analysis used hypotheses testing. Findings allowed to conclude that the perceived quality of the television service provided by television network is very positive, being the Soft Process Quality the parameter that reveals the highest perceived quality of the service as opposed to Potential Quality. To this end, some comments and suggestions were made by the clients regarding each one of these service quality parameters. Based on the hypotheses testing, it was noticed that only advertisement clients that maintain a connection to the television network from 5 to 10 years do show a significant different perception of the TV advertisement service provided by the company in what the Hard Process Quality parameter is concerned. Through the collected data content analysis, it was possible to obtain the percentage of clients which share the same opinions and suggestions for improvement. Finally, based on one of the four service quality parameter in a B2B context, managerial suggestions were developed aiming at improving the television network advertisement perceived quality service.

Keywords: B2B, case study, INDSERV, perceived service quality

Procedia PDF Downloads 202

Authors: M. Moyzykh, I. Klichuk, L. Sabirov, D. Kolomentseva, E. Magommedov

Abstract:

Modern city electrical grids are forced to increase their density due to the increasing number of customers and requirements for reliability and resiliency. However, progress in this direction is often limited by the capabilities of existing network equipment. New energy sources or grid connections increase the level of short-circuit currents in the adjacent network, which can exceed the maximum rating of equipment–breaking capacity of circuit breakers, thermal and dynamic current withstand qualities of disconnectors, cables, and transformers. Superconducting fault current limiter (SFCL) is a modern solution designed to deal with the increasing fault current levels in power grids. The key feature of this device is its instant (less than 2 ms) limitation of the current level due to the nature of the superconductor. In 2019 Moscow utilities installed SuperOx SFCL in the city power grid to test the capabilities of this novel technology. The SFCL became the first SFCL in the Russian energy system and is currently the most powerful SFCL in the world. Modern SFCL uses second-generation high-temperature superconductor (2G HTS). Despite its name, HTS still requires low temperatures of liquid nitrogen for operation. As a result, Moscow SFCL is built with a cryogenic system to provide cooling to the superconductor. The cryogenic system consists of three cryostats that contain a superconductor part and are filled with liquid nitrogen (three phases), three cryocoolers, one water chiller, three cryopumps, and pressure builders. All these components are controlled by an automatic control system. SFCL has been continuously operating on the city grid for over three years. During that period of operation, numerous faults occurred, including cryocooler failure, chiller failure, pump failure, and others (like a cryogenic system power outage). All these faults were eliminated without an SFCL shut down due to the specially designed cryogenic system backups and quick responses of grid operator utilities and the SuperOx crew. The paper will describe in detail the results of SFCL operation and cryogenic system maintenance and what measures were taken to solve and prevent similar faults in the future.

Keywords: superconductivity, current limiter, SFCL, HTS, utilities, cryogenics

Procedia PDF Downloads 75

Authors: Prince Suka Neekia Momta, Rita Iheoma Achonyeulo

Abstract:

Ant Tracking seismic attribute applied over 4-seconds seismic volume revealed structural features triggered by clay diapirism, growth fault development, rapid deltaic sedimentation and intense drilling. The attribute was extracted on vertical seismic sections and time slices. Mega tectonic structures such as growth faults and clay diapirs are visible on vertical sections with obscured minor lineaments or fractures. Fractures are distinctively visible on time slices yielding recognizable patterns corroborating established geologic models. This model seismic attribute enabled the understanding of fluid flow characteristics and production responses. Three structural patterns recognized in the field include: major growth faults, minor faults or lineaments and network of fractures. Three growth faults mapped on seismic section form major deformation bands delimiting the area into three blocks or depocenters. The growth faults trend E-W, dip down-to-south in the basin direction, and cut across the study area. The faults initiating from about 2000ms extended up to 500ms, and tend to progress parallel and opposite to the growth direction of an upsurging diapiric structure. The diapiric structures form the major deformational bands originating from great depths (below 2000ms) and rising to about 1200ms where series of sedimentary layers onlapped and pinchout stratigraphically against the diapir. Several other secondary faults or lineaments that form parallel streaks to one another also accompanied the growth faults. The fracture networks have no particular trend but form a network surrounding the well area. Faults identified in the study area have potentials for structural hydrocarbon traps whereas the presence of fractures created a fractured-reservoir condition that enhanced rapid fluid flow especially water. High aquifer flow potential aided by possible fracture permeability resulted in rapid decline in oil rate. Through the application of Ant Tracking attribute, it is possible to obtain detailed interpretation of structures that can have direct influence on oil and gas production.

Keywords: seismic, attributes, production, structural

Procedia PDF Downloads 53

Authors: Sara R. Knigge, Sugat R. Tuladhar, Alexander Becker, Tobias Schilling, Birgit Glasmacher

Abstract:

Commercially available mechanical or biological heart valve prostheses both tend to fail long-term due to thrombosis, calcific degeneration, infection, or immunogenic rejection. Moreover, these prostheses are non-viable and do not grow with the patients, which is a problem for young patients. As a result, patients often need to undergo redo-operations. Tissue-engineered (TE) heart valves based on degradable electrospun fiber scaffolds represent a promising approach to overcome these limitations. Such scaffolds need sufficient mechanical properties to withstand the hydrodynamic stress of intracardiac hemodynamics. Additionally, the scaffolds should be colonized by autologous or homologous cells to facilitate the in vivo remodeling of the scaffolds to a viable structure. This study investigates how process parameters of electrospinning and degradation affect the mechanical properties of electrospun scaffolds made of FDA-approved, biodegradable polymer polycaprolactone (PCL). Fiber mats were produced from a PCL/tetrafluoroethylene solution by electrospinning. The e-spinning process was varied in terms of scaffold thickness, fiber diameter, fiber orientation, and fiber interconnectivity. The morphology of the fiber mats was characterized with a scanning electron microscope (SEM). The mats were degraded in different solutions (cell culture media, SBF, PBS and 10 M NaOH-Solution). At different time points of degradation (2, 4 and 6 weeks), tensile and cyclic loading tests were performed. Fresh porcine pericardium and heart valves served as a control for the mechanical assessment. The progression of polymer degradation was quantified by SEM and differential scanning calorimetry (DSC). Primary Human aortic endothelial cells (HAECs) and Human induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) were seeded on the fiber mats to investigate the cell colonization potential. The results showed that both the electrospinning parameters and the degradation significantly influenced the mechanical properties. Especially the fiber orientation has a considerable impact and leads to a pronounced anisotropic behavior of the scaffold. Preliminary results showed that the polymer became strongly more brittle over time. However, the embrittlement can initially only be detected in the mechanical test. In the SEM and DSC investigations, neither morphological nor thermodynamic changes are significantly detectable. Live/Dead staining and SEM imaging of the cell-seeded scaffolds showed that HAECs and iPSC-ECs were able to grow on the surface of the polymer. In summary, this study's results indicate a promising approach to the development of a TE aortic heart valve based on an electrospun scaffold.

Keywords: electrospun scaffolds, long-term polymer degradation, mechanical behavior of electrospun PCL, tissue engineered aortic heart valve

Procedia PDF Downloads 133

Authors: Palash Soni, Vivek Kumar Gaba, Shubhankar Bhowmick, Bidyut Mazumdar

Abstract:

Refrigeration technology is a fast developing field at the present era since it has very wide application in both domestic and industrial areas. It started from the usage of simple ice coolers to store food stuffs to the present sophisticated cold storages along with other air conditioning system. A variety of techniques are used to bring down the temperature below the ambient. Adsorption refrigeration technology is a novel, advanced and promising technique developed in the past few decades. It gained attention due to its attractive property of exploiting unlimited natural sources like solar energy, geothermal energy or even waste heat recovery from plants or from the exhaust of locomotives to fulfill its energy need. This will reduce the exploitation of non-renewable resources and hence reduce pollution too. This work is aimed to develop a model for a solar adsorption refrigeration system and to simulate the same for different operating conditions. In this system, the mechanical compressor is replaced by a thermal compressor. The thermal compressor uses renewable energy such as solar energy and geothermal energy which makes it useful for those areas where electricity is not available. Refrigerants normally in use like chlorofluorocarbon/perfluorocarbon have harmful effects like ozone depletion and greenhouse warming. It is another advantage of adsorption systems that it can replace these refrigerants with less harmful natural refrigerants like water, methanol, ammonia, etc. Thus the double benefit of reduction in energy consumption and pollution can be achieved. A thermodynamic model was developed for the proposed adsorber, and a universal MATLAB code was used to simulate the model. Simulations were carried out for a different operating condition for the silicagel-methanol working pair. Various graphs are plotted between regeneration temperature, adsorption capacities, the coefficient of performance, desorption rate, specific cooling power, adsorption/desorption times and mass. The results proved that adsorption system could be installed successfully for refrigeration purpose as it has saving in terms of power and reduction in carbon emission even though the efficiency is comparatively less as compared to conventional systems. The model was tested for its compliance in a cold storage refrigeration with a cooling load of 12 TR.

Keywords: adsorption, refrigeration, renewable energy, silicagel-methanol

Procedia PDF Downloads 201

Authors: Michael Naderhirn, Marco Pavone

Abstract:

Problem statement, motivation, and aim of work: So far, the development of control algorithms was done by control engineers in a way that the controller would fit a specification by testing. When it comes to the certification of an autonomous car in highly complex scenarios, the challenge is much higher since such a controller must mathematically guarantee to implement the rules of the road while on the other side guarantee aspects like safety and real time executability. What if it becomes reality to solve this demanding problem by combining Formal Verification and System Theory? The aim of this work is to present a workflow to solve the above mentioned problem. Summary of the presented results / main outcomes: We show the usage of an English like language to transform the rules of the road into system specification for an autonomous car. The language based specifications are used to define system functions and interfaces. Based on that a formal model is developed which formally correctly models the specifications. On the other side, a mathematical model describing the systems dynamics is used to calculate the systems reachability set which is further used to determine the system input boundaries. Then a motion planning algorithm is applied inside the system boundaries to find an optimized trajectory in combination with the formal specification model while satisfying the specifications. The result is a control strategy which can be applied in real time independent of the scenario with a mathematical guarantee to satisfy a predefined specification. We demonstrate the applicability of the method in simulation driving scenarios and a potential certification. Originality, significance, and benefit: To the authors’ best knowledge, it is the first time that it is possible to show an automated workflow which combines a specification in an English like language and a mathematical model in a mathematical formal verified way to synthesizes a controller for potential real time applications like autonomous driving.

Keywords: formal system verification, reachability, real time controller, hybrid system

Procedia PDF Downloads 236

Authors: Noe Brice Nkoumbou Kaptchouang, Pierre-Guy Vincent, Yann Monerie

Abstract:

The present work addresses the modelling and the simulation of crack initiation and propagation in ductile materials which failed by void nucleation, growth, and coalescence. One of the current research frameworks on crack propagation is the use of cohesive-volumetric approach where the crack growth is modelled as a decohesion of two surfaces in a continuum material. In this framework, the material behavior is characterized by two constitutive relations, the volumetric constitutive law relating stress and strain, and a traction-separation law across a two-dimensional surface embedded in the three-dimensional continuum. Several cohesive models have been proposed for the simulation of crack growth in brittle materials. On the other hand, the application of cohesive models in modelling crack growth in ductile material is still a relatively open field. One idea developed in the literature is to identify the traction separation for ductile material based on the behavior of a continuously-deforming unit cell failing by void growth and coalescence. Following this method, the present study proposed a semi-analytical cohesive model for ductile material based on a micromechanical approach. The strain localization band prior to ductile failure is modelled as a cohesive band, and the Gurson-Tvergaard-Needleman plasticity model (GTN) is used to model the behavior of the cohesive band and derived a corresponding traction separation law. The numerical implementation of the model is realized using the non-smooth contact method (NSCD) where cohesive models are introduced as mixed boundary conditions between each volumetric finite element. The present approach is applied to the simulation of crack growth in nuclear ferritic steel. The model provides an alternative way to simulate crack propagation using the numerical efficiency of cohesive model with a traction separation law directly derived from porous continuous model.

Keywords: ductile failure, cohesive model, GTN model, numerical simulation

Procedia PDF Downloads 142

Authors: Mohammad Hassan Ramezan zadeh 1 , Majid Seifi 2 , Hoda Hekmat ara 2 1Biomedical Engineering Department, Near East University, Nicosia, Cyprus 2Physics Department, Guilan University , P.O. Box 41335-1914, Rasht, Iran.

Abstract:

Magnetic nano particles of ferric chloride were synthesised using a co-precipitation technique. For the optimal results, ferric chloride at room temperature was added to different surfactant with different ratio of metal ions/surfactant. The samples were characterised using transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectrum to show the presence of nanoparticles, structure and morphology. Magnetic measurements were also carried out on samples using a Vibrating Sample Magnetometer. To show the effect of surfactant on size distribution and crystalline structure of produced nanoparticles, surfactants with various charge such as anionic cetyl trimethyl ammonium bromide (CTAB), cationic sodium dodecyl sulphate (SDS) and neutral TritonX-100 was employed. By changing the surfactant and ratio of metal ions/surfactant the size and crystalline structure of these nanoparticles were controlled. We also show that using anionic stabilizer leads to smallest size and narrowest size distribution and the most crystalline (polycrystalline) structure. In developing our production technique, many parameters were varied. Efforts at reproducing good yields indicated which of the experimental parameters were the most critical and how carefully they had to be controlled. The conditions reported here were the best that we encountered but the range of possible parameter choice is so large that these probably only represent a local optimum. The samples for our chemical process were prepared by adding 0.675 gr ferric chloride (FeCl3, 6H2O) to three different surfactant in water solution. The solution was sonicated for about 30 min until a transparent solution was achieved. Then 0.5 gr sodium hydroxide (NaOH) as a reduction agent was poured to the reaction drop by drop which resulted to participate reddish brown Fe2O3 nanoparticles. After washing with ethanol the obtained powder was calcinated in 600°C for 2h. Here, the sample 1 contained CTAB as a surfactant with ratio of metal ions/surfactant 1/2, sample 2 with CTAB and ratio 1/1, sample 3 with SDS and ratio 1/2, sample 4 SDS 1/1, sample 5 is triton-X-100 with 1/2 and sample 6 triton-X-100 with 1/1.

Keywords: iron oxide nanoparticles, stabilizer, co-precipitation, surfactant

Procedia PDF Downloads 245

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

Authors: Moshe Mello, Hilary Rutto, Tumisang Seodigeng

Abstract:

The nature of tires makes them extremely challenging to recycle due to the available chemically cross-linked polymer and, therefore, they are neither fusible nor soluble and, consequently, cannot be remolded into other shapes without serious degradation. Open dumping of tires pollutes the soil, contaminates underground water and provides ideal breeding grounds for disease carrying vermins. The thermal decomposition of tires by pyrolysis produce char, gases and oil. The composition of oils derived from waste tires has common properties to commercial diesel fuel. The problem associated with the light oil derived from pyrolysis of waste tires is that it has a high sulfur content (> 1.0 wt.%) and therefore emits harmful sulfur oxide (SOx) gases to the atmosphere when combusted in diesel engines. Desulphurization of TPO is necessary due to the increasing stringent environmental regulations worldwide. Hydrodesulphurization (HDS) is the commonly practiced technique for the removal of sulfur species in liquid hydrocarbons. However, the HDS technique fails in the presence of complex sulfur species such as Dibenzothiopene (DBT) present in TPO. This study aims to investigate the viability of photodegradation (Photocatalytic oxidative desulphurization) and adsorptive desulphurization technologies for efficient removal of complex and non-complex sulfur species in TPO. This study focuses on optimizing the cleaning (removal of impurities and asphaltenes) process by varying process parameters; temperature, stirring speed, acid/oil ratio and time. The treated TPO will then be sent for vacuum distillation to attain the desired diesel like fuel. The effect of temperature, pressure and time will be determined for vacuum distillation of both raw TPO and the acid treated oil for comparison purposes. Polycyclic sulfides present in the distilled (diesel like) light oil will be oxidized dominantly to the corresponding sulfoxides and sulfone via a photo-catalyzed system using TiO2 as a catalyst and hydrogen peroxide as an oxidizing agent and finally acetonitrile will be used as an extraction solvent. Adsorptive desulphurization will be used to adsorb traces of sulfurous compounds which remained during photocatalytic desulphurization step. This desulphurization convoy is expected to give high desulphurization efficiency with reasonable oil recovery.

Keywords: adsorption, asphaltenes, photocatalytic oxidation, pyrolysis

Procedia PDF Downloads 269

Authors: Halkiopoulos Constantinos, Koutsopoulou Ioanna, Gkintoni Evgenia, Antonopoulou Hera

Abstract:

Immunization appears to be an essential part of health care service in times of pandemics such as covid-19 and aims not only to protect the health of the population but also the health and sustainability of the economies of the countries affected. It is reported that more than 3.44 billion doses have been administered so far, which accounts for 45 doses for 100 people. Vaccination programs in various countries have been promoted and accepted by people differently and therefore they proceeded in different ways and speed; most countries directing them towards people with vulnerable chronic or recent health statuses. Large scale restriction measures or lockdown, personal protection measures such as masks and gloves and a decrease in leisure and sports activities were also implemented around the world as part of the protection health strategies against the covid-19 pandemic. This research aims to present an analysis based on variations on people’s attitudes towards vaccination based on demographic, social and epidemiological characteristics, and health status on the one hand and perception of health, health satisfaction, pain, and quality of life on the other hand. 1500 Greek e-consumers participated in the research, mainly through social media who took part in an online-based survey voluntarily. The questionnaires included demographic, social and medical characteristics of the participants, and questions asking people’s willingness to be vaccinated and their opinion on whether there should be a vaccine against covid-19. Other stressor factors were also reported in the questionnaires and participants’ loss of someone close due to covid-19, or staying at home quarantine due to being infected from covid-19. WHOQUOL-BREF and GLOBAL PSYCHOTRAUMA SCREEN- GPS were used with kind permission from WHO and from the International Society for Traumatic Stress Studies in this study. Attitudes towards vaccination varied significantly related to aging, level of education, health status and consumer behavior. Health professionals’ attitudes also varied in relation to age, level of education, profession, health status and consumer needs. Vaccines have been the most common technological aid of human civilization so far in the fight against viruses. The results of this study can be used for health managers and digital marketers of pharmaceutical companies and also other staff involved in vaccination programs and for designing health policy immunization strategies during pandemics in order to achieve positive attitudes towards vaccination and larger populations being vaccinated in shorter periods of time after the break out of pandemic. Health staff needs to be trained, aided and supervised to go through with vaccination programs and to be protected through vaccination programs themselves. Feedback in each country’s vaccination program, short backs, deficiencies and delays should be addressed and worked out.

Keywords: consumer behavior, cognitive models, vaccination policy, pandemic, Covid-19, Greece

Procedia PDF Downloads 180

Authors: Jacob Seddlemeyer, Tahar Messadi, Hongmei Gu, Mahboobeh Hemmati

Abstract:

The main purpose of this first tier of the study is to quantify and compare the embodied environmental impacts associated with alternative materials applied to Adohi Hall, a residence building at the University of Arkansas campus, Fayetteville, AR. This 200,000square foot building has5 stories builtwith mass timber and is compared to another scenario where the same edifice is built with a steel frame. Based on the defined goal and scope of the project, the materials respectivetothe respective to the two building options are compared in terms of Global Warming Potential (GWP), starting from cradle to the construction site, which includes the material manufacturing stage (raw material extract, process, supply, transport, and manufacture) plus transportation to the site (module A1-A4, based on standard EN 15804 definition). The consumedfossil fuels and emitted CO2 associated with the buildings are the major reason for the environmental impacts of climate change. In this study, GWP is primarily assessed to the exclusion of other environmental factors. The second tier of this work is to evaluate Tally’s performance in the decision-making process through the design phases, as well as determine its strengths and weaknesses. Tally is a Life Cycle Assessment (LCA) tool capable of conducting a cradle-to-grave analysis. As opposed to other software applications, Tally is specifically targeted at buildings LCA. As a peripheral application, this software tool is directly run within the core modeling application platform called Revit. This unique functionality causes Tally to stand out from other similar tools in the building sector LCA analysis. The results of this study also provide insights for making more environmentally efficient decisions in the building environment and help in the move forward to reduce Green House Gases (GHGs) emissions and GWP mitigation.

Keywords: comparison, GWP, LCA, materials, tally

Procedia PDF Downloads 219

Authors: Roberto de Lieto Vollaro, Emanuele de Lieto Vollaro, Gianluca Coltrinari

Abstract:

The building sector is responsible, in many industrialized countries, for about 40% of the total energy requirements, so it seems necessary to devote some efforts in this area in order to achieve a significant reduction of energy consumption and of greenhouse gases emissions. The paper presents a study aiming at providing a design methodology able to identify the best configuration of the system building/plant, from a technical, economic and environmentally point of view. Normally, the classical approach involves a building's energy loads analysis under steady state conditions, and subsequent selection of measures aimed at improving the energy performance, based on previous experience made by architects and engineers in the design team. Instead, the proposed approach uses a sequence of two well known scientifically validated calculation methods (TRNSYS and RETScreen), that allow quite a detailed feasibility analysis. To assess the validity of the calculation model, an existing, historical building in Central Italy, that will be the object of restoration and preservative redevelopment, was selected as a case-study. The building is made of a basement and three floors, with a total floor area of about 3,000 square meters. The first step has been the determination of the heating and cooling energy loads of the building in a dynamic regime by means of TRNSYS, which allows to simulate the real energy needs of the building in function of its use. Traditional methodologies, based as they are on steady-state conditions, cannot faithfully reproduce the effects of varying climatic conditions and of inertial properties of the structure. With TRNSYS it is possible to obtain quite accurate and reliable results, that allow to identify effective combinations building-HVAC system. The second step has consisted of using output data obtained with TRNSYS as input to the calculation model RETScreen, which enables to compare different system configurations from the energy, environmental and financial point of view, with an analysis of investment, and operation and maintenance costs, so allowing to determine the economic benefit of possible interventions. The classical methodology often leads to the choice of conventional plant systems, while RETScreen provides a financial-economic assessment for innovative energy systems and low environmental impact. Computational analysis can help in the design phase, particularly in the case of complex structures with centralized plant systems, by comparing the data returned by the calculation model RETScreen for different design options. For example, the analysis performed on the building, taken as a case study, found that the most suitable plant solution, taking into account technical, economic and environmental aspects, is the one based on a CCHP system (Combined Cooling, Heating, and Power) using an internal combustion engine.

Keywords: energy, system, building, cooling, electrical

Procedia PDF Downloads 568

Authors: T. Arkle, D. Pournaras, S. Lam, B. Kumar

Abstract:

Introduction: Fundoplication is widely recognised as the best surgical option for gastro-oesophageal reflux disease (GORD) in the general population. However, there is controversy surrounding the use of conventional fundoplication in obese patients. Whilst the intra-operative failure of fundoplication, including wrap disruption, is reportedly higher in obese individuals, the more significant issue surrounds symptom recurrence post-surgery. Could a bariatric procedure be considered in obese patients for weight management, to treat the GORD, and to also reduce the risk of recurrence? Roux-en-Y gastric bypass, a widely performed bariatric procedure, has been shown to be highly successful both in controlling GORD symptoms and in weight management in obese patients. Furthermore, NICE has published clear guidelines on eligibility for bariatric surgery, with the main criteria being type 3 obesity or type 2 obesity with the presence of significant co-morbidities that would improve with weight loss. This study aims to identify the proportion of patients who undergo conventional fundoplication for GORD and/or hiatus hernia, which would have been eligible for bariatric surgery referral according to NICE guidelines. Methods: All patients who underwent fundoplication procedures for GORD and/or hiatus hernia repair at a single NHS foundation trust over a 10-year period will be identified using the Trust’s health records database. Pre-operative patient records will be used to find BMI and the presence of significant co-morbidities at the time of consideration for surgery. This information will be compared to NICE guidelines to determine potential eligibility for the bariatric surgical referral at the time of initial surgical intervention. Results: A total of 321 patients underwent fundoplication procedures between January 2011 and December 2020; 133 (41.4%) had available data for BMI or to allow BMI to be estimated. Of those 133, 40 patients (30%) had a BMI greater than 30kg/m², and 7 (5.3%) had BMI >35kg/m². One patient (0.75%) had a BMI >40 and would therefore be automatically eligible according to NICE guidelines. 4 further patients had significant co-morbidities, such as hypertension and osteoarthritis, which likely be improved by weight management surgery and therefore also indicated eligibility for referral. Overall, 3.75% (5/133) of patients undergoing conventional fundoplication procedures would have been eligible for bariatric surgical referral, these patients were all female, and the average age was 60.4 years. Conclusions: Based on this Trust’s experience, around 4% of obese patients undergoing fundoplication would have been eligible for bariatric surgical intervention. Based on current evidence, in class 2/3 obese patients, there is likely to have been a notable proportion with recurrent disease, potentially requiring further intervention. These patient’s may have benefitted more through undergoing bariatric surgery, for example a Roux-en-Y gastric bypass, addressing both their obesity and GORD. Use of patient written notes to obtain BMI data for the 188 patients with missing BMI data and further analysis to determine outcomes following fundoplication in all patients, assessing for incidence of recurrent disease, will be undertaken to strengthen conclusions.

Keywords: bariatric surgery, GORD, Nissen fundoplication, nice guidelines

Procedia PDF Downloads 56

Authors: Seember Susan Aondoakura

Abstract:

This paper examines the international legal framework established to address the challenges women and girls experience in situations of violent conflict. The United Nations (UN) women, peace, and security agenda (hereafter WPS agenda, the Agenda) aspire to make wars safer for women. It recognizes women's agency in armed conflict and their victimization and formulates measures for their protection. The Agenda also acknowledges women's participation in conflict transformation and post-conflict reconstruction. It also calls for the involvement of women in conflict transformation, encourages the protection of women from sex and gender-based violence (SGBV), and provides relief and recovery from conflict-related SGBV. Using Third World Critical Feminist Theory, this paper argues that the WPS agenda overly focus on the protection of women from SGBV occurring in the less developed and conflict-ridden states in the global south, obscures the complicity of western states and economies to the problem, and silences the privileges that such states derive from war economies that continue to fuel conflict. This protectionist approach of the UN also obliterates other equally pressing problems in need of attention, like the high rates of economic degradation in conflict-ravaged societies of the global south. Prioritising protection also 'others' the problem, obliterating any sense of interconnections across geographical locations and situating women in the less developed economies of the global south as the victims and their men as the perpetrators. Prioritising protection ultimately situates western societies as saviours of Third World women with no recourse to their role in engendering and sustaining war. The paper demonstrates that this saviour mentality obliterates chances of any meaningful coalition between the local and the international in framing and addressing the issue, as solutions are formulated from a specific lens—the white hegemonic lens.

Keywords: conflict, protection, security, SGBV

Procedia PDF Downloads 91

Authors: Kubilay Kurtulus Bastas

Abstract:

Bacterial diseases are very destructive and cause economic losses on pears. Promising plant extracts for the management of plant diseases are environmentally safe, long-lasting and extracts of certain plants contain alkaloids, tannins, quinones, coumarins, phenolic compounds, and phytoalexins. In this study, bacteria were isolated from different parts of pear exhibiting characteristic symptoms of bacterial diseases from the Central Anatolia, Turkey. Pathogenic bacteria were identified by morphological, physiological, biochemical and molecular methods as fire blight (Erwinia amylovora (39%)), bacterial blossom blast and blister bark (Pseudomonas syringae pv. syringae (22%)), crown gall (Rhizobium radiobacter (1%)) from different pear cultivars, and determined virulence levels of the pathogens with pathogenicity tests. The air-dried 25 plant material was ground into fine powder and extraction was performed at room temperature by maceration with 80% (v/v) methanol/distilled water. The minimum inhibitory concentration (MIC) values were determined by using modified disc diffusion method at five different concentrations and streptomycin sulphate was used as control chemical. Bacterial suspensions were prepared as 108 CFU ml⁻¹ densities and 100 µl bacterial suspensions were spread to TSA medium. Antimicrobial activity was evaluated by measuring the inhibition zones in reference to the test organisms. Among the tested plants, Origanum vulgare, Hedera helix, Satureja hortensis, Rhus coriaria, Eucalyptus globulus, Rosmarinus officinalis, Ocimum basilicum, Salvia officinalis, Cuminum cyminum and Thymus vulgaris showed a good antibacterial activity and they inhibited the growth of the pathogens with inhibition zone diameter ranging from 7 to 27 mm at 20% (w/v) in absolute methanol in vitro conditions. In vivo, the highest efficacy was determined as 27% on reducing tumor formation of R. radiobacter, and 48% and 41% on reducing shoot blight of E. amylovora and P. s. pv. syringae on pear seedlings, respectively. Obtaining data indicated that some plant extracts may be used against the bacterial diseases on pome fruits within sustainable and organic management programs.

Keywords: bacteria, eco-friendly management, organic, pear, plant extract

Procedia PDF Downloads 319

Authors: R. Pillai Aparna, S. R. Gandhi

Abstract:

Soft clay deposits having low strength and high compressibility are found all over the world. Preloading with vertical drains is a widely used method for improving such type of soils. The coefficient of consolidation, irrespective of the drainage type, plays an important role in the design of vertical drains and it controls accurate prediction of the rate of consolidation of soil. Also, the increase in shear strength of soil with consolidation is another important factor considered in preloading or staged construction. To our best knowledge no clear guidelines are available to estimate the increase in shear strength for a particular degree of consolidation (U) at various stages during the construction. Various methods are available for finding out the consolidation coefficient. This study mainly focuses on the variation of, consolidation coefficient which was found out using different methods and shear strength with pressure intensity. The variation of shear strength with the degree of consolidation was also studied. The consolidation test was done using two types of highly compressible clays with vertical, radial and a few with combined drainage. The test was carried out at different pressures intensities and for each pressure intensity, once the target degree of consolidation is achieved, vane shear test was done at different locations in the sample, in order to determine the shear strength. The shear strength of clayey soils under the application of vertical stress with vertical and radial drainage with target U value of 70% and 90% was studied. It was found that there is not much variation in cv or cr value beyond 80kPa pressure intensity. Correlations were developed between shear strength ratio and consolidation pressure based on laboratory testing under controlled condition. It was observed that the shear strength of sample with target U value of 90% is about 1.4 to 2 times than that of 70% consolidated sample. Settlement analysis was done using Asaoka’s and hyperbolic method. The variation of strength with respect to the depth of sample was also studied, using large-scale consolidation test. It was found, based on the present study that the gain in strength is more on the top half of the clay layer, and also the shear strength of the sample ensuring radial drainage is slightly higher than that of the vertical drainage.

Keywords: consolidation coefficient, degree of consolidation, PVDs, shear strength

Procedia PDF Downloads 228

Authors: Mae C. Pavilario

Abstract:

This study employs a sequential explanatory mixed method. Quantitatively it investigated the profile of grade VII students. Qualitatively, the prevailing contextual variables that affect their frustration-level were sought based on their perspective and that of their parents and teachers. These students were categorized as frustration-level in reading based on the data on word list of the Philippine Informal Reading Inventory (Phil-IRI). The researcher-made reading factor instrument translated to local dialect (Hiligaynon) was subjected to cross-cultural translation to address content, semantic, technical, criterion, or conceptual equivalence, the open-ended questions, and one unstructured interview was utilized. In the profile of the 26 participants, the 12 males are categorized as grade II and grade III frustration-levels. The prevailing contextual variables are personal-“having no interest in reading”, “being ashamed and fear of having to read in front of others” for extremely high frustration level; social environmental-“having no regular reading schedule at home” for very high frustration level and personal- “having no interest in reading” for high frustration level. Kendall Tau inferential statistical tool was used to test the significant relationship in the prevailing contextual variables that affect frustration-level readers when grouped according to perspective. Result showed that significant relationship exists between students-parents perspectives; however, there is no significant relationship between students’ and teachers’, and parents’ and teachers’ perspectives. The themes in the narratives of the participants on frustration-level readers are existence of speech defects, undesirable attitude, insufficient amount of reading materials, lack of close supervision from parents, and losing time and focus on task. Intervention was designed.

Keywords: contextual variables, frustration-level readers, perspective, inquiry

Procedia PDF Downloads 161

Authors: Isabelle Gobatto

Abstract:

Based on an anthropological approach, this paper explores the medical profession and the construction of medical practices by considering the multiform articulations between structural poverty and the production of care from a low-resource francophone West African country, Burkina Faso. This country is considered in its exemplary dimension of culturally differentiated countries of the African continent that share the same situation of structural poverty. The objective is to expose the effects of structural poverty on the ways of constructing professional knowledge and thinking about the sense of the medical profession. If doctors are trained to have the same capacities in South and West countries, which are to treat and save lives whatever the cultural contexts of the practice of medicine, the ways of investing their role and of dealing with this context of action fracture the homogenization of the medical profession. In the line of anthropology of biomedicine, this paper outlines the complex effects of structural poverty on health care, care relations, and the moral economy of doctors. The materials analyzed are based on an ethnography including two temporalities located thirty years apart (1990-1994 and 2020-2021), based on long-term observations of care practices conducted in healthcare institutions, interviews coupled with the life histories of physicians. The findings reveal that disabilities faced by doctors to deliver care are interpreted as policy gaps, but they are also considered by physicians as constitutive of the social and cultural characteristics of patients, making their capacities and incapacities in terms of accompanying caregivers in the production of care. These perceptions have effects on know-how, structured around the need to act even when diagnoses are not made so as not to see patients desert health structures if the costs of care are too high for them. But these interpretations of highly individualizing dimensions of these difficulties place part of the blame on patients for the difficulties in using learned knowledge and delivering effective care. These situations challenge the ethics of caregivers but also of ethnologists. Firstly because the interpretations of disabilities prevent caregivers from considering vulnerabilities of care as constituting a common condition shared with their patients in these health systems, affecting them in an identical way although in different places in the production of care. Correlatively, these results underline that these professional conceptions prevent the emergence of a figure of victim, which could be shared between patients and caregivers who, together, undergo working and care conditions at the limit of the acceptable. This dimension directly involves politics. Secondly, structural poverty and its effects on care challenge the ethics of the anthropologist who observes caregivers producing, without intent to arm, experiences of care marked by an ordinary violence, by not giving them the care they need. It is worth asking how anthropologists could get doctors to think in this light in west-African societies.

Keywords: Africa, care, ethics, poverty

Procedia PDF Downloads 63

Authors: Amit Kumar Happy

Abstract:

This paper is motivated by the importance of multi-sensor image fusion with a specific focus on infrared (IR) and visual image (VI) fusion for various applications, including military reconnaissance. Image fusion can be defined as the process of combining two or more source images into a single composite image with extended information content that improves visual perception or feature extraction. These images can be from different modalities like visible camera & IR thermal imager. While visible images are captured by reflected radiations in the visible spectrum, the thermal images are formed from thermal radiation (infrared) that may be reflected or self-emitted. A digital color camera captures the visible source image, and a thermal infrared camera acquires the thermal source image. In this paper, some image fusion algorithms based upon multi-scale transform (MST) and region-based selection rule with consistency verification have been proposed and presented. This research includes the implementation of the proposed image fusion algorithm in MATLAB along with a comparative analysis to decide the optimum number of levels for MST and the coefficient fusion rule. The results are presented, and several commonly used evaluation metrics are used to assess the suggested method's validity. Experiments show that the proposed approach is capable of producing good fusion results. While deploying our image fusion algorithm approaches, we observe several challenges from the popular image fusion methods. While high computational cost and complex processing steps of image fusion algorithms provide accurate fused results, they also make it hard to become deployed in systems and applications that require a real-time operation, high flexibility, and low computation ability. So, the methods presented in this paper offer good results with minimum time complexity.

Keywords: image fusion, IR thermal imager, multi-sensor, multi-scale transform

Procedia PDF Downloads 107

Authors: Zhanara Suleimenova, Raushan Blieva, Aigerim Zhakipbekova, Inkar Tapenbayeva, Zhanar Narmuratova

Abstract:

Green processes are based on innovative technologies that do not negatively affect the environment. Industrial enzymes originated from biological systems can effectively contribute to sustainable development through being isolated from microorganisms which are fermented using primarily renewable resources. Many widespread microorganisms secrete a significant amount of biocatalysts into the environment, which greatly facilitates the task of their isolation and purification. The ability to control the enzyme production through the regulation of their biosynthesis and the selection of nutrient media and cultivation conditions allows not only to increase the yield of enzymes but also to obtain enzymes with certain properties. In this regard, large potentialities are embedded in immobilized cells. Enzyme production technology in a secreted active form enabling industrial application on an economically feasible scale has been developed. This method is based on the immobilization of enzyme producers on a solid career. Immobilizing has a range of advantages: decreasing the price of the final product, absence of foreign substances, controlled process of enzyme-genesis, the ability of various enzymes' simultaneous production, etc. Design of proposed equipment gives the opportunity to increase the activity of immobilized cell culture filtrate comparing to free cells, growing in periodic culture conditions. Such technology allows giving a 10-times raise in culture productivity, to prolong the process of fungi cultivation and periods of active culture liquid generation. Also, it gives the way to improve the quality of filtrates (to make them more clear) and exclude time-consuming processes of recharging fermentative vials, that require manual removing of mycelium.

Keywords: industrial enzymes, immobilization, submerged fermentation, microscopic fungi

Procedia PDF Downloads 134

Authors: Jonathan Ham, Christopher Koch

Abstract:

There are consistently observed associations between certain odors and colors, and there is an association between the ability to imagine vivid visual objects and imagine vivid odors. However, little has been done to investigate how the associations between odors and visual information effect visual processes. This study seeks to understand the relationship between odor imaging, color associations, and visual attention by utilizing a Stroop-task based on common odor-color associations. This Stroop-task was designed using three fruits with distinct odors that are associated with the color of the fruit: lime with green, strawberry with red, and lemon with yellow. Each possible word-color combination was presented in the experimental trials. When the word matched the associated color (lime written in green) it was considered congruent; if it did not, it was considered incongruent (lime written in red or yellow). In experiment I (n = 34) participants were asked to both imagine the odor of the fruit on the screen and identify which fruit it was, and each word-color combination was presented 20 times (a total of 180 trials, with 60 congruent and 120 incongruent instances). Response time and error rate of the participant responses were recorded. There was no significant difference in either measure between the congruent and incongruent trials. In experiment II participants (n = 18) followed the identical procedure as in the previous experiment with the addition of an odorant in the room. The odorant (orange) was not the fruit or color used in the experimental trials. With a fruit-based odorant in the room, the response times (measured in milliseconds) between congruent and incongruent trials were significantly different, with incongruent trials (M = 755.919, SD = 239.854) having significantly longer response times than congruent trials (M = 690.626, SD = 198.822), t (1, 17) = 4.154, p < 0.01. This suggests that odor imagery does affect visual attention to colors, and the ability to inhibit odor-color associations; however, odor imagery is difficult and appears to be facilitated in the presence of a related odorant.

Keywords: odor-color associations, odor imagery, visual attention, inhibition

Procedia PDF Downloads 168

Authors: Jukka Törrönen

Abstract:

In the article, we examine the interplay between the practices of heavy drinking and exercise among young people as patterned around the ‘social’ and ‘physical health’ approaches. The comparison helps us to clarify why young people are currently drinking less than earlier and how the neoliberal healthism discourse, as well as the feminine tradition of taking care of one’s body, are modifying young people’s heavy drinking practices. The data is based on interviews (n = 56) in Sweden among 15-16-year-olds and 18˗19-year-olds. By drawing on Pierre Bourdieu’s concepts of habitus, field, and capital, we examine what kinds of resources of wellbeing young people accumulate in the fields of heavy drinking and exercise, how these resources carry symbolic value for distinction, and what kind of health-related habitus they imply. The analysis suggests that as heavy drinking is no longer able to stand as a practice through which one may acquire capital that is more valuable than the capital acquired in other fields, this lessens peer pressure to drink among young people. Our analysis further shows that the healthism discourse modifies young people’s heavy drinking practices both from inside and from outside. The interviewees translate the symbolic value of healthism discourse to social vulnerability and deploy it for the purposes of increasing one’s social status among peers. Moreover, our analysis demonstrates that the social spaces and positions in intoxication and exercise are shaped by gendered dualisms of masculine dominance. However, while the interviewees naturalize the gender binaries in intoxication as based on biological drives, they understand gender binaries in exercise as normative social constructions of neoliberal society. As these binaries emphasize the struggle for recognition of the symbolic value of bodily look, they may shift young men’s attention from risk-taking to issues that traditionally have been female concerns.

Keywords: young people, decline in drinking , health, intoxication, exercise, Bourdieu

Procedia PDF Downloads 110

Authors: Antonina Semakova, Karim Mynbaev, Nikolai Bazhenov, Anton Chernyaev, Sergei Kizhaev, Nikolai Stoyanov

Abstract:

At present, heterostructures are used for fabrication of almost all types of optoelectronic devices. Our research focuses on the optoelectronic properties of InAs(Sb) solid solutions that are widely used in fabrication of light emitting diodes (LEDs) operating in middle wavelength infrared range (MWIR). This spectral range (2-6 μm) is relevant for laser diode spectroscopy of gases and molecules, for systems for the detection of explosive substances, medical applications, and for environmental monitoring. The fabrication of MWIR LEDs that operate efficiently at room temperature is mainly hindered by the predominance of non-radiative Auger recombination of charge carriers over the process of radiative recombination, which makes practical application of LEDs difficult. However, non-radiative recombination can be partly suppressed in quantum-well structures. In this regard, studies of such structures are quite topical. In this work, electroluminescence (EL) of LED heterostructures based on InAs(Sb) epitaxial films with the molar fraction of InSb ranging from 0 to 0.09 and multi quantum-well (MQW) structures was studied in the temperature range 4.2-300 K. The growth of the heterostructures was performed by metal-organic chemical vapour deposition on InAs substrates. On top of the active layer, a wide-bandgap InAsSb(Ga,P) barrier was formed. At low temperatures (4.2-100 K) stimulated emission was observed. As the temperature increased, the emission became spontaneous. The transition from stimulated emission to spontaneous one occurred at different temperatures for structures with different InSb contents in the active region. The temperature-dependent carrier lifetime, limited by radiative recombination and the most probable Auger processes (for the materials under consideration, CHHS and CHCC), were calculated within the framework of the Kane model. The effect of various recombination processes on the carrier lifetime was studied, and the dominant role of Auger processes was established. For MQW structures quantization energies for electrons, light and heavy holes were calculated. A characteristic feature of the experimental EL spectra of these structures was the presence of peaks with energy different from that of calculated optical transitions between the first quantization levels for electrons and heavy holes. The obtained results showed strong effect of the specific electronic structure of InAsSb on the energy and intensity of optical transitions in nanostructures based on this material. For the structure with MQWs in the active layer, a very weak temperature dependence of EL peak was observed at high temperatures (>150 K), which makes it attractive for fabricating temperature-resistant gas sensors operating in the middle-infrared range.

Keywords: Electroluminescence, InAsSb, light emitting diode, quantum wells

Procedia PDF Downloads 205

Authors: Eleni Tsalkatidou

Abstract:

Despite the fact that women's sport has flourished in recent years, its media coverage remains low, as it is observed that every day men’s sports stories dominate the most popular sports websites and the same doesn’t apply to women. Many studies in the past have demonstrated that the participation of women in sport is greatly underrepresented in the media and even when it does get covered, the focus is often on femininity and attractiveness, not athleticism. This means that female athletes are often portrayed in a sexist manner and, in general, they are more deserving of media coverage as celebrities rather than because of their sporting achievements. Scholars have argued that sport is a place where sexism is cultivated, as gender roles are constructed and disputed based on social context. Although images and information about women athletes are now more than ever, thanks to Social Media where they also act as 'producers', sport is still considered as «masculine». There are many reasons why this happens, the most important of which are: a. It is considered that females don’t have the physical and athletic qualifications such as men and b. Women's sport is less commercial than men’s, so the interest is lower. Moreover, scholars have pointed out that men journalists/reporters don’t cover the women’s sport: it is more common for a woman to write about a women's sport or a female athlete. This has its roots in the conception that sport is synonymous with masculinity - which is defined as the opposite of femininity – and so if men deal with women’s sport, this will probably menace their association with masculinity. Given the above, this paper seeks to examine the amount of women’s sport coverage of five Greek popular sports websites (metrosport.gr, gazzeta.gr, sport24.gr, sdna.gr, sport-fm.gr). The posted articles from these Greek websites from January to June 2020 were selected for my content analysis, which will be used to categorize the themes in order that the following research questions could be answered: 1) Are there any articles that cover women's sports or that refer to female athletes?, 2) And if so, are they articles/reports or is it a reproduction of the press release?, 3) What kind of sports do they refer to (individual-team sport)?, 4) Are the articles signed? And if so, are they written by men or women?, 5) What textual practices are used to cover women's sport/female athletes?, 6) Based on the findings, could we argue that we have entered a new age of media coverage of women’s sport in Greece with a shift towards greater gender equality or not?

Keywords: Coverage, Greek websites, Sport, Women

Procedia PDF Downloads 138

Authors: Maria Reznakova, Michala Strnadova, Lukas Reznak

Abstract:

Successful achievement of strategic goals requires an effective performance management system, i.e. determining the appropriate indicators measuring the rate of goal achievement. Assuming that the goal of the owners is to grow the assets they invested in, it is vital to identify the key performance indicators, which contribute to value creation. These indicators are known as value drivers. Based on the undertaken literature search, a value driver is defined as any factor that affects the value of an enterprise. The important factors are then monitored by both financial and non-financial indicators. Financial performance indicators are most useful in strategic management, since they indicate whether a company's strategy implementation and execution are contributing to bottom line improvement. Non-financial indicators are mainly used for short-term decisions. The identification of value drivers, however, is problematic for companies which are not publicly traded. Therefore financial ratios continue to be used to measure the performance of companies, despite their considerable criticism. The main drawback of such indicators is the fact that they are calculated based on accounting data, while accounting rules may differ considerably across different environments. For successful enterprise performance management it is vital to avoid factors that may reduce (or even destroy) its value. Among the known factors reducing the enterprise value are the lack of capital, lack of strategic management system and poor quality of production. In order to gain further insight into the topic, the paper presents results of the research identifying factors that adversely affect the performance of mechanical engineering enterprises in the Czech Republic. The research methodology focuses on both the qualitative and the quantitative aspect of the topic. The qualitative data were obtained from a questionnaire survey of the enterprises senior management, while the quantitative financial data were obtained from the Analysis Major Database for European Sources (AMADEUS). The questionnaire prompted managers to list factors which negatively affect business performance of their enterprises. The range of potential factors was based on a secondary research – analysis of previously undertaken questionnaire surveys and research of studies published in the scientific literature. The results of the survey were evaluated both in general, by average scores, and by detailed sub-analyses of additional criteria. These include the company specific characteristics, such as its size and ownership structure. The evaluation also included a comparison of the managers’ opinions and the performance of their enterprises – measured by return on equity and return on assets ratios. The comparisons were tested by a series of non-parametric tests of statistical significance. The results of the analyses show that the factors most detrimental to the enterprise performance include the incompetence of responsible employees and the disregard to the customers‘ requirements.

Keywords: business value, financial ratios, performance measurement, value drivers

Procedia PDF Downloads 217