Search results for: special moment frame
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3959

Search results for: special moment frame

869 Lifespan Assessment of the Fish Crossing System of Itaipu Power Plant (Brazil/Paraguay) Based on the Reaching of Its Sedimentological Equilibrium Computed by 3D Modeling and Churchill Trapping Efficiency

Authors: Anderson Braga Mendes, Wallington Felipe de Almeida, Cicero Medeiros da Silva

Abstract:

This study aimed to assess the lifespan of the fish transposition system of the Itaipu Power Plant (Brazil/Paraguay) by using 3D hydrodynamic modeling and Churchill trapping effiency in order to identify the sedimentological equilibrium configuration in the main pond of the Piracema Channel, which is part of a 10 km hydraulic circuit that enables fish migration from downstream to upstream (and vice-versa) the Itaipu Dam, overcoming a 120 m water drop. For that, bottom data from 2002 (its opening year) and 2015 were collected and analyzed, besides bed material at 12 stations to the purpose of identifying their granulometric profiles. The Shields and Yalin and Karahan diagrams for initiation of motion of bed material were used to determine the critical bed shear stress for the sedimentological equilibrium state based on the sort of sediment (grain size) to be found at the bottom once the balance is reached. Such granulometry was inferred by analyzing the grosser material (fine and medium sands) which inflows the pond and deposits in its backwater zone, being adopted a range of diameters within the upper and lower limits of that sand stratification. The software Delft 3D was used in an attempt to compute the bed shear stress at every station under analysis. By modifying the input bathymetry of the main pond of the Piracema Channel so as to the computed bed shear stress at each station fell within the intervals of acceptable critical stresses simultaneously, it was possible to foresee the bed configuration of the main pond when the sedimentological equilibrium is reached. Under such condition, 97% of the whole pond capacity will be silted, and a shallow water course with depths ranging from 0.2 m to 1.5 m will be formed; in 2002, depths ranged from 2 m to 10 m. Out of that water path, the new bottom will be practically flat and covered by a layer of water 0.05 m thick. Thus, in the future the main pond of the Piracema Channel will lack its purpose of providing a resting place for migrating fish species, added to the fact that it may become an insurmountable barrier for medium and large sized specimens. Everything considered, it was estimated that its lifespan, from the year of its opening to the moment of the sedimentological equilibrium configuration, will be approximately 95 years–almost half of the computed lifespan of Itaipu Power Plant itself. However, it is worth mentioning that drawbacks concerning the silting in the main pond will start being noticed much earlier than such time interval owing to the reasons previously mentioned.

Keywords: 3D hydrodynamic modeling, Churchill trapping efficiency, fish crossing system, Itaipu power plant, lifespan, sedimentological equilibrium

Procedia PDF Downloads 223
868 Cybersecurity for Digital Twins in the Built Environment: Research Landscape, Industry Attitudes and Future Direction

Authors: Kaznah Alshammari, Thomas Beach, Yacine Rezgui

Abstract:

Technological advances in the construction sector are helping to make smart cities a reality by means of cyber-physical systems (CPS). CPS integrate information and the physical world through the use of information communication technologies (ICT). An increasingly common goal in the built environment is to integrate building information models (BIM) with the Internet of Things (IoT) and sensor technologies using CPS. Future advances could see the adoption of digital twins, creating new opportunities for CPS using monitoring, simulation, and optimisation technologies. However, researchers often fail to fully consider the security implications. To date, it is not widely possible to assimilate BIM data and cybersecurity concepts, and, therefore, security has thus far been overlooked. This paper reviews the empirical literature concerning IoT applications in the built environment and discusses real-world applications of the IoT intended to enhance construction practices, people’s lives and bolster cybersecurity. Specifically, this research addresses two research questions: (a) how suitable are the current IoT and CPS security stacks to address the cybersecurity threats facing digital twins in the context of smart buildings and districts? and (b) what are the current obstacles to tackling cybersecurity threats to the built environment CPS? To answer these questions, this paper reviews the current state-of-the-art research concerning digital twins in the built environment, the IoT, BIM, urban cities, and cybersecurity. The results of these findings of this study confirmed the importance of using digital twins in both IoT and BIM. Also, eight reference zones across Europe have gained special recognition for their contributions to the advancement of IoT science. Therefore, this paper evaluates the use of digital twins in CPS to arrive at recommendations for expanding BIM specifications to facilitate IoT compliance, bolster cybersecurity and integrate digital twin and city standards in the smart cities of the future.

Keywords: BIM, cybersecurity, digital twins, IoT, urban cities

Procedia PDF Downloads 149
867 Sociological Analysis on Prisoners; with Special Reference to Prisoners of Death Penalty and Life Imprisonment in Sri Lanka

Authors: Wasantha Subasinghe

Abstract:

Crimes are one of big social problems in Sri Lanka. Crimes can be seen as simply way as an activity that against for the society or public law. There are offences in minor crimes and grave crimes including murder, rape, trafficking, robbery, excise, narcotic, kidnapping and so on. There are various forms of punishment such as bailing, fining, and prisoning to the death penalty. Death penalty contains the killing of an offender for an offense. There are 23 prison institutions in Sri Lanka including 03 closed prisoners and 20 remand prisons. There are 10 work camps, 02 open prison camps, 01 training school for youthful offenders and 02 correctional centers for youthful offenders. Capital punishment is legal in Sri Lanka as many other countries as India, Japan, Bangladesh, Iran and Iraq so on. When compared unconvicted prisoners from 2006-2010 there is an increase. It was 89190 in 2006 and it was 100191 in 2010. There were 28732 of convicted prisoners and it was 32128 in 2010. There were 165 Death sentences in 2006 and it was 96 in 2010. There are 540 individuals had been sentenced to death. The death penalty has not been implemented in Sri Lanka since 1976. Research problem: What are the feelings of prisoners as waiting for death?’ Objectives of the study were identifying prisoners’ point of view on their punishment and root causes for their offence. Case studies were conducted to identify the research problem and data were collected using formal interviews. Research area was Welikada prison. Stratified sampling method in probability samplings was used. Sample size was 20 cases from death penalty and life in prison prisoners and 20 from other convicted prisoners. Findings revealed causes and feelings them as offenders. They need if death penalty or freedom. Some of them need to convert death sentence to life imprisonment. They are physically and mentally damaged after their imprisonment. Lack of hope and as well as lack of welfare and rehabilitation programs they suffered their lives.

Keywords: death penalty, expectations, life imprisonment, rehabilitation

Procedia PDF Downloads 271
866 Analysis of Rock Cutting Progress with a New Axe-Shaped PDC Cutter to Improve PDC Bit Performance in Elastoplastic Formation

Authors: Fangyuan Shao, Wei Liu, Deli Gao

Abstract:

Polycrystalline diamond compact (PDC) bits have occupied a large market of unconventional oil and gas drilling. The application of PDC bits benefits from the efficient rock breaking of PDC cutters. In response to increasingly complex formations, many shaped cutters have been invited, but many of them have not been solved by the mechanism of rock breaking. In this paper, two kinds of PDC cutters: a new axe-shaped (NAS) cutter and cylindrical cutter (benchmark) were studied by laboratory experiments. NAS cutter is obtained by optimizing two sides of axe-shaped cutter with curved surfaces. All the cutters were put on a vertical turret lathe (VTL) in the laboratory for cutting tests. According to the cutting distance, the VTL tests can be divided into two modes: single-turn rotary cutting and continuous cutting. The cutting depth of cutting (DOC) was set at 1.0 mm and 2.0 mm in the former mode. The later mode includes a dry VTL test for thermal stability and a wet VTL test for wear resistance. Load cell and 3D optical profiler were used to obtain the value of cutting forces and wear area, respectively. Based on the findings of the single-turn rotary cutting VTL tests, the performance of A NAS cutter was better than the benchmark cutter on elastoplastic material cutting. The cutting forces (normal forces, tangential force, and radial force) and special mechanical energy (MSE) of a NAS cutter were lower than that of the benchmark cutter under the same condition. It meant that a NAS cutter was more efficient on elastoplastic material breaking. However, the wear resistance of a new axe-shaped cutter was higher than that of a benchmark cutter. The results of the dry VTL test showed that the thermal stability of a NAS cutter was higher than that of a benchmark cutter. The cutting efficiency can be improved by optimizing the geometric structure of the PDC cutter. The change of thermal stability may be caused by the decrease of the contact area between cutter and rock at given DOC. The conclusions of this paper can be used as an important reference for PDC cutters designers.

Keywords: axe-shaped cutter, PDC cutter, rotary cutting test, vertical turret lathe

Procedia PDF Downloads 195
865 The Properties of Risk-based Approaches to Asset Allocation Using Combined Metrics of Portfolio Volatility and Kurtosis: Theoretical and Empirical Analysis

Authors: Maria Debora Braga, Luigi Riso, Maria Grazia Zoia

Abstract:

Risk-based approaches to asset allocation are portfolio construction methods that do not rely on the input of expected returns for the asset classes in the investment universe and only use risk information. They include the Minimum Variance Strategy (MV strategy), the traditional (volatility-based) Risk Parity Strategy (SRP strategy), the Most Diversified Portfolio Strategy (MDP strategy) and, for many, the Equally Weighted Strategy (EW strategy). All the mentioned approaches were based on portfolio volatility as a reference risk measure but in 2023, the Kurtosis-based Risk Parity strategy (KRP strategy) and the Minimum Kurtosis strategy (MK strategy) were introduced. Understandably, they used the fourth root of the portfolio-fourth moment as a proxy for portfolio kurtosis to work with a homogeneous function of degree one. This paper contributes mainly theoretically and methodologically to the framework of risk-based asset allocation approaches with two steps forward. First, a new and more flexible objective function considering a linear combination (with positive coefficients that sum to one) of portfolio volatility and portfolio kurtosis is used to alternatively serve a risk minimization goal or a homogeneous risk distribution goal. Hence, the new basic idea consists in extending the achievement of typical risk-based approaches’ goals to a combined risk measure. To give the rationale behind operating with such a risk measure, it is worth remembering that volatility and kurtosis are expressions of uncertainty, to be read as dispersion of returns around the mean and that both preserve adherence to a symmetric framework and consideration for the entire returns distribution as well, but also that they differ from each other in that the former captures the “normal” / “ordinary” dispersion of returns, while the latter is able to catch the huge dispersion. Therefore, the combined risk metric that uses two individual metrics focused on the same phenomena but differently sensitive to its intensity allows the asset manager to express, in the context of an objective function by varying the “relevance coefficient” associated with the individual metrics, alternatively, a wide set of plausible investment goals for the portfolio construction process while serving investors differently concerned with tail risk and traditional risk. Since this is the first study that also implements risk-based approaches using a combined risk measure, it becomes of fundamental importance to investigate the portfolio effects triggered by this innovation. The paper also offers a second contribution. Until the recent advent of the MK strategy and the KRP strategy, efforts to highlight interesting properties of risk-based approaches were inevitably directed towards the traditional MV strategy and SRP strategy. Previous literature established an increasing order in terms of portfolio volatility, starting from the MV strategy, through the SRP strategy, arriving at the EQ strategy and provided the mathematical proof for the “equalization effect” concerning marginal risks when the MV strategy is considered, and concerning risk contributions when the SRP strategy is considered. Regarding the validity of similar conclusions when referring to the MK strategy and KRP strategy, the development of a theoretical demonstration is still pending. This paper fills this gap.

Keywords: risk parity, portfolio kurtosis, risk diversification, asset allocation

Procedia PDF Downloads 50
864 Depression among Pregnant Women with Husbands Abroad during the Pregnancy

Authors: Usama Bin Zubair, Syed Azhar Ali

Abstract:

Introduction: Depression is emerging as a major public health problem in all parts of the world. Developing countries have a unique socioeconomic structure that affects the lives of its inhabitants in several ways. Going abroad for employment is one of the common social problems which have been faced by young males in developing countries. This included both highly qualified individuals as well as the labor class. Objective: To determine the difference in the presence of depressive symptoms among pregnant women with husbands living abroad and those with husbands living with them in Azad Jammu and Kashmir. Methods: The sample population comprised of pregnant women reporting for an antenatal checkup at Amna hospital Rawalakot. Cases constituted the pregnant women with husbands living abroad while controls were the pregnant women with husbands living with them. Patient health questionnaire-9 (PHQ-9) was used to record the presence and severity of depressive symptoms. Age, gestation, parity, rural or urban origin, education, level of family income, daily contact hours on the telephone or what’s app, previous pregnancy loss or complications, number of years abroad and visits to home per year were associated with the presence of depressive symptoms. Findings: The mean age of the study participants was 29.73 ±5.395 years. Sixty-six had significant depression in the case group, while 14 had in the control group (p-value<0.001). Education and rural background had a significant difference between the case and the control group. Less number of visits per year of the husband was strongly linked with the presence of depressive symptoms among the cases. Conclusion: Pregnant women with husbands abroad were found more prone to develop depressive symptoms as compared to those with husbands living with them. Special attention should be paid to the women whose husband had a lesser number of visits to the country.

Keywords: depression, pregnancy, lack of support, war zone

Procedia PDF Downloads 112
863 Influence of Dynamic Loads in the Structural Integrity of Underground Rooms

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

Abstract:

Among many factors affecting the stability of mining excavations, rock-bursts and tremors play a special role. These dynamic loads occur practically always and have different sources of generation. The most important of them is the commonly used mining technique, which disintegrates a certain area of the rock mass not only in the area of the planned mining, but also creates waves that significantly exceed this area affecting the structural elements. In this work it is analysed the consequences of dynamic loads over the structural elements in an underground room and pillar mine to avoid roof instabilities. With this end, dynamic loads were evaluated through in situ and laboratory tests and simulated with numerical modelling. Initially, the geotechnical characterization of all materials was carried out by mean of large-scale tests. Then, drill holes were done on the roof of the mine and were monitored to determine possible discontinuities in it. Three seismic stations and a triaxial accelerometer were employed to measure the vibrations from blasting tests, establish the dynamic behaviour of roof and pillars and develop the transmission laws. At last, computer simulations by FLAC3D software were done to check the effect of vibrations on the stability of the roofs. The study shows that in-situ tests have a greater reliability than laboratory samples because of eliminating the effect of heterogeneities, that the pillars work decreasing the amplitude of the vibration around them, and that the tensile strength of a beam and depending on its span is overcome with waves in phase and delayed. The obtained transmission law allows designing a blasting which guarantees safety and prevents the risk of future failures.

Keywords: dynamic modelling, long term instability risks, room and pillar, seismic collapse

Procedia PDF Downloads 126
862 Study of Irritant and Anti-inflammatory Activity of Snuhi/Zaqqum (Euphorbia nerifolia) with Special Reference to Holy Quran and Ayurveda

Authors: Mohammed Khalil Ur Rahman, Pradnya Chigle, Bushra Farhen

Abstract:

Indian mythology believes that Vedas are eternal treatises. Vedas are categorized into four divisions viz., Rigveda, Yajurveda, Samveda, Atharveda. All these spiritual classics not only deal with rituals and customs but also consist of inclusion of many references related to health. Out of these four, Atharveda deals with maximum principles pertaining to health sciences. Therefore, it is said that the science and the art of Ayurveda has developed from Atharveda. Ayurveda deals with many medicinal plants either as a single therapeutic use or in combination. One such medicinal plant is Snuhi (Euphorbia neriifolia Linn.) which finds its extensive importance along with Haridra and Apamargakshar, in the preparation of Ksharsutra which in turn is used for the treatment of Fistula in Ano. It is interesting to note that this plant Snuhi is also referred in Holy Quran as the Tree of Zaqqum advocated as the food for the sinners as a part of torment. The reference in Surat Ad-Dukhan is as follows: - 44:43-46. “Verily, the tree of Zaqqum will be the food of the sinners, Like boiling oil, it will boil in the bellies, like the boiling of scalding water.” The above verse implies that plant Snuhi/Zaqqum due to irritant property acts as a drastic purgative but at the same time it also possesses anti inflammatory properties in order to relieve the irritation. These properties of Zaqqum has been unfolded in the modern research which states that, Diterpene polycyclic esters are responsible for its toxic and irritant nature whereas; triterpenes are responsible for its anti inflammatory property. Present work will be an effort to review the concept of Quran about latex of the Tree of Zaqqum in terms of its phytochemistry and its therapeutic use in Ksharsutra pertaining to irritant and anti inflammatory property.

Keywords: ayurveda, Quran, zaqqum, ksharsutra, latex piles, inflammation

Procedia PDF Downloads 346
861 A Sustainability Benchmarking Framework Based on the Life Cycle Sustainability Assessment: The Case of the Italian Ceramic District

Authors: A. M. Ferrari, L. Volpi, M. Pini, C. Siligardi, F. E. Garcia Muina, D. Settembre Blundo

Abstract:

A long tradition in the ceramic manufacturing since the 18th century, primarily due to the availability of raw materials and an efficient transport system, let to the birth and development of the Italian ceramic tiles district that nowadays represents a reference point for this sector even at global level. This economic growth has been coupled to attention towards environmental sustainability issues throughout various initiatives undertaken over the years at the level of the production sector, such as certification activities and sustainability policies. In this way, starting from an evaluation of the sustainability in all its aspects, the present work aims to develop a benchmarking helping both producers and consumers. In the present study, throughout the Life Cycle Sustainability Assessment (LCSA) framework, the sustainability has been assessed in all its dimensions: environmental with the Life Cycle Assessment (LCA), economic with the Life Cycle Costing (LCC) and social with the Social Life Cycle Assessment (S-LCA). The annual district production of stoneware tiles during the 2016 reference year has been taken as reference flow for all the three assessments, and the system boundaries cover the entire life cycle of the tiles, except for the LCC for which only the production costs have been considered at the moment. In addition, a preliminary method for the evaluation of local and indoor emissions has been introduced in order to assess the impact due to atmospheric emissions on both people living in the area surrounding the factories and workers. The Life Cycle Assessment results, obtained from IMPACT 2002+ modified assessment method, highlight that the manufacturing process is responsible for the main impact, especially because of atmospheric emissions at a local scale, followed by the distribution to end users, the installation and the ordinary maintenance of the tiles. With regard to the economic evaluation, both the internal and external costs have been considered. For the LCC, primary data from the analysis of the financial statements of Italian ceramic companies show that the higher cost items refer to expenses for goods and services and costs of human resources. The analysis of externalities with the EPS 2015dx method attributes the main damages to the distribution and installation of the tiles. The social dimension has been investigated with a preliminary approach by using the Social Hotspots Database, and the results indicate that the most affected damage categories are health and safety and labor rights and decent work. This study shows the potential of the LCSA framework applied to an industrial sector; in particular, it can be a useful tool for building a comprehensive benchmark for the sustainability of the ceramic industry, and it can help companies to actively integrate sustainability principles into their business models.

Keywords: benchmarking, Italian ceramic industry, life cycle sustainability assessment, porcelain stoneware tiles

Procedia PDF Downloads 113
860 Prevention of Ragging and Sexual Gender Based Violence (SGBV) in Higher Education Institutions in Sri Lanka

Authors: Anusha Edirisinghe

Abstract:

Sexual Gender based violence is a most common social phenomenon in higher education institutions. It has become a hidden crime of the Universities. Masculinities norms and attitudes are more influential and serve as key drivers and risk for ragging and SGBV. This research will reveal that in Sri Lankan universities, SGBV takes from the violence and murder of women students, assault and battery coerced sex, sexual harassment including harassment via information technology. This study focus is to prevention of ragging and SGBV in University system. Main objective of this paper describes and critically analyses of plight of ragging and SGBV in higher education institutions and legal and national level policy implementation to prevent these crimes in society. This paper is with special reference to ragging case from University of Kelaniya 2016. University Grant commission introduced an Act for the prevention of Ragging and gender standing committee established in Sri Lanka in 2016. And each university has been involved in the prevention of SGBV and ragging in higher education institutions. Case study from first year female student, reported sexual harassment was reported to the police station in May in 2016. After this case, the university has been implementing emergency action plan, short term and long term action plan. Ragging and SGBV task force was established and online complaint center opened to all students and academic and non- academics. Under these circumstances student complained to SGBV and other harassment to the university. University security system was strong support with police and marshals, and vigilant committees including lecturers. After this case all universities start to several programmes to stop violence in university

Keywords: higher Education, ragging, sexual gender-based violence, Sri Lanka

Procedia PDF Downloads 367
859 Natural Monopolies and Their Regulation in Georgia

Authors: Marina Chavleishvili

Abstract:

Introduction: Today, the study of monopolies, including natural monopolies, is topical. In real life, pure monopolies are natural monopolies. Natural monopolies are used widely and are regulated by the state. In particular, the prices and rates are regulated. The paper considers the problems associated with the operation of natural monopolies in Georgia, in particular, their microeconomic analysis, pricing mechanisms, and legal mechanisms of their operation. The analysis was carried out on the example of the power industry. The rates of natural monopolies in Georgia are controlled by the Georgian National Energy and Water Supply Regulation Commission. The paper analyzes the positive role and importance of the regulatory body and the issues of improving the legislative base that will support the efficient operation of the branch. Methodology: In order to highlight natural monopolies market tendencies, the domestic and international markets are studied. An analysis of monopolies is carried out based on the endogenous and exogenous factors that determine the condition of companies, as well as the strategies chosen by firms to increase the market share. According to the productivity-based competitiveness assessment scheme, the segmentation opportunities, business environment, resources, and geographical location of monopolist companies are revealed. Main Findings: As a result of the analysis, certain assessments and conclusions were made. Natural monopolies are quite a complex and versatile economic element, and it is important to specify and duly control their frame conditions. It is important to determine the pricing policy of natural monopolies. The rates should be transparent, should show the level of life in the country, and should correspond to the incomes. The analysis confirmed the significance of the role of the Antimonopoly Service in the efficient management of natural monopolies. The law should adapt to reality and should be applied only to regulate the market. The present-day differential electricity tariffs varying depending on the consumed electrical power need revision. The effects of the electricity price discrimination are important, segmentation in different seasons in particular. Consumers use more electricity in winter than in summer, which is associated with extra capacities and maintenance costs. If the price of electricity in winter is higher than in summer, the electricity consumption will decrease in winter. The consumers will start to consume the electricity more economically, what will allow reducing extra capacities. Conclusion: Thus, the practical realization of the views given in the paper will contribute to the efficient operation of natural monopolies. Consequently, their activity will be oriented not on the reduction but on the increase of increments of the consumers or producers. Overall, the optimal management of the given fields will allow for improving the well-being throughout the country. In the article, conclusions are made, and the recommendations are developed to deliver effective policies and regulations toward the natural monopolies in Georgia.

Keywords: monopolies, natural monopolies, regulation, antimonopoly service

Procedia PDF Downloads 76
858 Religion: A Tool for Conflict Resolution and Peace in Nigerian Society

Authors: V. U. Onyemauwa

Abstract:

Conflicts have always been part of human societies. So long as there is interaction amongst individuals or societies, there are bound to be conflicts as a result of the fact that interests among individuals and societies vary. The issue of conflict has become one of the regular headlines in the daily news of the Nigerian and global media today. Nigerian polity has suffered from one conflict or another, ranging from religious, civil, political, cultural, regional and ethnic violence. It has been found out that, the most disturbing part of these acts of conflicts in Nigeria and around the globe is that most of them have traced their roots to religion. Even some perpetrators of these acts of conflicts most of the time justify their actions with religion, thereby wrongly making religion an object of conflict and violence. In this regard, the study seeks to project religion as a potent tool for conflict resolution because it has a way of permeating through the hearts of men. It has a special responsibility of identifying conflicts and proffer solutions. It also has to provide theological reasoning as to why and how these conflicts come about and how they can possibly be solved. Religious actors are known to contribute to the processes of structural reform necessary for the restoration of productive social relations and political stability after a period of conflict and human rights abuses. The study examines the modalities for projecting religious conflict management strategies in Nigeria using an analysis of relevant documents as well as Black’s Social Control Theory and Thomas-Kilmann’s Model of Conflict Management as its theoretical frameworks. It recommends for a religiously-based means of conflict resolution in Nigeria. Religious individuals and faith-based organisations, as carriers of religious ideas are implore to play active roles in conflict resolution and peace-building in Nigeria by creating conducive environment for peaceful talks, mediation and reconciliation. This will enhance social cohesion, provides solid foundation for peace, progress and development in the society.

Keywords: conflict, peace, religion, resolution

Procedia PDF Downloads 380
857 Elastomeric Nanocomposites for Space Applications

Authors: Adriana Stefan, Cristina-Elisabeta Pelin, George Pelin, Maria Daniela Stelescu, Elena Manaila

Abstract:

Elastomeric composites have been known for a long time, but, to our knowledge, space and the aeronautic community has been directing a special attention to them only in the last decade. The required properties of advanced elastomeric materials used in space applications (such as O-rings) are sealing, abrasion, low-temperature flexibility, the long-term compression set properties, impact resistance and low-temperature thermal stability in different environments, such as ionized radiations. Basically, the elastomeric nanocomposites are composed of a rubber matrix and a wide and varied range of nanofillers, added with the aim of improving the physico-mechanical and elasticity modulus properties of the materials as well as their stability in different environments. The paper presents a partial synthesis of the research regarding the use of silicon carbide in nanometric form and/or organophylized montmorillonite as fillers in butyl rubber matrix. The need of composite materials arose from the fact that stand-alone polymers are ineffective in providing all the superior properties required by different applications. These drawbacks can be diminished or even eliminated by incorporating a new range of additives into the organic matrix, fillers that have important roles in modifying properties of various polymers. A composite material can provide superior and unique mechanical and physical properties because it combines the most desirable properties of its constituents while suppressing their least desirable properties. The commercial importance of polymers and the continuous increase of their use results in the continuous demand for improvement in their properties to meet the necessary conditions. To study the performance of the elastomeric nanocomposites were mechanically tested, it will be tested the qualities of tensile at low temperatures and RT and the behavior at the compression at cryogenic to room temperatures and under different environments. The morphology of specimens will be investigated by optical and scanning electronic microscopy.

Keywords: elastomeric nanocomposites, O-rings, space applications, mechanical properties

Procedia PDF Downloads 273
856 (Re)Processing of ND-Fe-B Permanent Magnets Using Electrochemical and Physical Approaches

Authors: Kristina Zuzek, Xuan Xu, Awais Ikram, Richard Sheridan, Allan Walton, Saso Sturm

Abstract:

Recycling of end-of-life REEs based Nd-Fe-B magnets is an important strategy for reducing the environmental dangers associated with rare-earth mining and overcoming the well-documented supply risks related to the REEs. However, challenges on their reprocessing still remain. We report on the possibility of direct electrochemical recycling and reprocessing of Nd-Fe(B)-based magnets. In this investigation, we were able first to electrochemically leach the end-of-life NdFeB magnet and to electrodeposit Nd–Fe using a 1-ethyl-3-methyl imidazolium dicyanamide ([EMIM][DCA]) ionic liquid-based electrolyte. We observed that Nd(III) could not be reduced independently. However, it can be co-deposited on a substrate with the addition of Fe(II). Using advanced TEM techniques of electron-energy-loss spectroscopy (EELS) it was shown that Nd(III) is reduced to Nd(0) during the electrodeposition process. This gave a new insight into determining the Nd oxidation state, as X-ray photoelectron spectroscopy (XPS) has certain limitations. This is because the binding energies of metallic Nd (Nd0) and neodymium oxide (Nd₂O₃) are very close, i. e., 980.5-981.5 eV and 981.7-982.3 eV, respectively, making it almost impossible to differentiate between the two states. These new insights into the electrodeposition process represent an important step closer to efficient recycling of rare piles of earth in metallic form at mild temperatures, thus providing an alternative to high-temperature molten-salt electrolysis and a step closer to deposit Nd-Fe-based magnetic materials. Further, we propose a new concept of recycling the sintered Nd-Fe-B magnets by direct recovering the 2:14:1 matrix phase. Via an electrochemical etching method, we are able to recover pure individual 2:14:1 grains that can be re-used for new types of magnet production. In the frame of physical reprocessing, we have successfully synthesized new magnets out of hydrogen (HDDR)-recycled stocks with a contemporary technique of pulsed electric current sintering (PECS). The optimal PECS conditions yielded fully dense Nd-Fe-B magnets with the coercivity Hc = 1060 kA/m, which was boosted to 1160 kA/m after the post-PECS thermal treatment. The Br and Hc were tackled further and increased applied pressures of 100 – 150 MPa resulted in Br = 1.01 T. We showed that with a fine tune of the PECS and post-annealing it is possible to revitalize the Nd-Fe-B end-of-life magnets. By applying advanced TEM, i.e. atomic-scale Z-contrast STEM combined with EDXS and EELS, the resulting magnetic properties were critically assessed against various types of structural and compositional discontinuities down to atomic-scale, which we believe control the microstructure evolution during the PECS processing route.

Keywords: electrochemistry, Nd-Fe-B, pulsed electric current sintering, recycling, reprocessing

Procedia PDF Downloads 144
855 Exploration of an Environmentally Friendly Form of City Development Combined with a River: An Example of a Four-Dimensional Analysis Based on the Expansion of the City of Jinan across the Yellow River

Authors: Zhaocheng Shang

Abstract:

In order to study the topic of cities crossing rivers, a Four-Dimensional Analysis Method consisting of timeline, X-axis, Y-axis, and Z-axis is proposed. Policies, plans, and their implications are summarized and researched along with the timeline. The X-axis is the direction which is parallel to the river. The research area was chosen because of its important connection function. It is proposed that more surface water network should be built because of the ecological orientation of the research area. And the analysis of groundwater makes it for sure that the proposal is feasible. After the blue water network is settled, the green landscape network which is surrounded by it could be planned. The direction which is transversal to the river (Y-axis) should run through the transportation axis so that the urban texture could stretch in an ecological way. Therefore, it is suggested that the work of the planning bureau and river bureau should be coordinated. The Z-axis research is on the section view of the river, especially on the Yellow River’s special feature of being a perched river. Based on water control safety demands, river parks could be constructed on the embankment buffer zone, whereas many kinds of ornamental trees could be used to build the buffer zone. City Crossing River is a typical case where we make use of landscaping to build a symbiotic relationship between the urban landscape architecture and the environment. The local environment should be respected in the process of city expansion. The planning order of "Benefit- Flood Control Safety" should be replaced by "Flood Control Safety - Landscape Architecture- People - Benefit".

Keywords: blue-green landscape network, city crossing river, four-dimensional analysis method, planning order

Procedia PDF Downloads 146
854 The Effectiveness of Logotherapy in Alleviating Social Isolation for Visually Impaired Students

Authors: Mohamed M. Elsherbiny, Ahmed T. Helal Ibrahim

Abstract:

Social isolation is one of the common problems faced visual impaired students especially in new situations. It refers to lack of interactions with others (students, staff members, and others) and dissatisfaction of social networks with others. In addition, it means "a lack of quantity and quality of social contacts". The situation became more complicated if we know that visual impaired students at Sultan Qaboos University were in special schools for the blind completely away from any integration with regular student, which may lead to isolation for being with regular students for the first time. Because the researcher is an academic advisor for all blind students in the College of Arts and Social Sciences at Sultan Qaboos University, he has noted (from the regular meetings with them) some aspects of isolation and many complaints from staff which motivated the researcher to try to alleviate the problem. Logotherapy is an important therapy used in clinical social work with various problems to help children and young people who are facing problems related to the lack of meaning in their life. So, the aim of the therapy is to find meaning in life and to be satisfied with that life. The basic meaning for visual impaired students in this study is to provide opportunities to build relationships and friendships with others and help them to be satisfied about interactions with their networks. The study aimed to identify whether there is a relationship between the use of logotherapy and alleviating social isolation for visual impaired students. This study is considered one of the quasi-experimental studies, the researcher has used experimental method. The researcher used one design which is before and after experiment on two groups, one control (did not apply to the therapy) and experimental group which is applied to the therapy. About the study tools, social isolation scale (SIS) was used to assess the degree of isolation. The sample was (20) of the visually impaired students at the College of Arts and Social Sciences, Sultan Qaboos University. The results showed the effectiveness of logotherapy in alleviating isolation for students.

Keywords: social isolation, logotherapy, visually impaired, disability

Procedia PDF Downloads 363
853 Translation of the Verbal Nouns (Masadars) Originating from Three-Letter Verbs in the Holy Quran: Verbal Noun with More than One Pattern (Wazn) As a Model

Authors: Montasser Mohamed Abdelwahab Mahmoud, Abdelwahab Saber Esawi

Abstract:

The language of the Qur’an has a wide range of understanding, reflection, and meanings. Therefore, translation of the Qur’an is inevitably nothing but a translation of the interpretation of the meanings of the Qur’an. It requires special competencies and skills for translators so that they can get close to the intended meaning of the verse of the Qur’an and convey it with precision. In the Arabic language, the verbal noun “AlMasdar” is a very important derivative that properly expresses the verbal idea in the form of a noun. It sounds the same as the base form of the verb with minor changes in the vowel pattern. It is one of the important topics in morphology. The morphologists divided verbal nouns into auditory and analogical, and they stated that that the verbal nouns (Masadars) originating from three-letter verbs are auditory, although they set controls for some of them in order to preserve them. As for the lexicographers, they mentioned the verbal nouns while talking about the lexical materials, and in some cases, their explanation of them exceeded that made by the morphologists, especially in their discussion of structures that the morphologists did not refer to in their books. The verb kafara (disbelief), for example, has three patterns, namely: al-kufْr, al-kufrān, and al-kufūr, and it was mentioned in the Holy Qur’an with different connotations. The verb ṣāma (fasted) with his two patterns (al-ṣaūm and al-ṣīām) was mentioned in the Holy Qur’an while their semantic meaning is different. The problem discussed in this research paper lied in the "linguistic loss" committed by translators when dealing with Islamic religious texts, especially the Qur'an. The study tried to identify the strategy adopted by translators of the Holy Qur'an in translating words that were classified as verbal nouns through analyzing the translation rendered by five translations of the Qur’an into English: Yusuf Ali, Pickthall, Mohsin Khan, Muhammad Sarwar, and Shakir. This study was limited to the verbal nouns in the Quraan that originate from three-letter verbs and have different semantic meanings.

Keywords: pattern, three-letter verbs, translation of the Quran, verbal nouns

Procedia PDF Downloads 149
852 Evaluate Effects of Different Curing Methods on Compressive Strength, Modulus of Elasticity and Durability of Concrete

Authors: Dhara Shah, Chandrakant Shah

Abstract:

Construction industry utilizes plenty of water in the name of curing. Looking at the present scenario, the days are not so far when all construction industries will have to switch over to an alternative-self curing system, not only to save water for sustainable development of the environment but also to promote indoor and outdoor construction activities even in water scarce areas. At the same time, curing is essential for the development of proper strength and durability. IS 456-2000 recommends a curing period of 7 days for ordinary Portland cement concrete, and 10 to 14 days for concrete prepared using mineral admixtures or blended cements. But, being the last act in the concreting operations, it is often neglected or not fully done. Consequently, the quality of hardened concrete suffers, more so, if the freshly laid concrete gets exposed to the environmental conditions of low humidity, high wind velocity and high ambient temperature. To avoid the adverse effects of neglected or insufficient curing, which is considered a universal phenomenon, concrete technologist and research scientists have come up with curing compounds. Concrete is said to be self-cured, if it is able to retain its water content to perform chemical reaction for the development of its strength. Curing compounds are liquids which are either incorporated in concrete or sprayed directly onto concrete surfaces and which then dry to form a relatively impermeable membrane that retards the loss of moisture from the concrete. They are an efficient and cost-effective means of curing concrete and may be applied to freshly placed concrete or that which has been partially cured by some other means. However, they may affect the bond between concrete and subsequent surface treatments. Special care in the choice of a suitable compound needs to be exercised in such circumstances. Curing compounds are generally formulated from wax emulsions, chlorinated rubbers, synthetic and natural resins, and from PVA emulsions. Their effectiveness varies quite widely, depending on the material and strength of the emulsion.

Keywords: curing methods, self-curing compound, compressive strength, modulus of elasticity, durability

Procedia PDF Downloads 315
851 Full Disclosure Policy: Transparency in Fiscal Administration

Authors: Joyly Jill Apud

Abstract:

Corruption is an all-encompassing issue worldwide. Many attempts have been done to address such cases especially by the government through increasing transparency. The Philippine government increased the mechanism of transparency by opening to public its financial transactions through Full Disclosure Policy – mandating all local governments to post in their websites all financial transactions (Philippine Public Transparency Reporting Project, 2011). For transparency to be fully realized, the challenge lies in creating a mechanism where the constituents are encouraged to engage as social auditors. In line of the said challenge, the study focused in Davao City, Philippines measuring the respondent’s awareness, access and utilization of Full Disclosure Policy (FDP). Particularly, this study determined the significant difference on the awareness, access and utilization of respondents when grouped according to sector and the significant relationship between respondents’ awareness and in the access and utilization of FDP reports. The study used descriptive-correlation, Mean, Anova and Pearson R as statistical treatment. The 120 respondents are from the different sectors of Davao City. These are the Academe, Youth, LGUs, NGOs, Business, and Church groups. The awareness of the respondents was measured in three main categories: Existence of the Policy, Content of the Policy and the Manner of Publication. Access and Utilization of the FDP reports is divided into three: Budget Reports, Procurement Reports and Special Purpose Fund Reports. Results showed that the respondents are moderately aware of the Policy. Though it manifested that the respondents are aware of the disclosure, they are unaware of the Full Disclosure Policy and Full Disclosure Policy Portal. Moreover, the respondents seldom access and utilize all the FDP reports. Further results revealed that there is a significant difference in the awareness and the access and utilization of FDP when grouped according to sector. Moreover, significant relationship in the awareness and the access and utilization of the FDP is evident. It showed that the higher the awareness on FDP, the higher the level of access and utilization on the FDP reports.

Keywords: corruption, e-governance, budget transparency, participation

Procedia PDF Downloads 370
850 The Effects of Damping Devices on Displacements, Velocities and Accelerations of Structures

Authors: Radhwane Boudjelthia

Abstract:

The most recent earthquakes occurred in the world have killed thousands of people and severe damage. For all the actors involved in the building process, the earthquake is the litmus test for construction. The goal we set ourselves is to contribute to the implementation of a thoughtful approach to the seismic protection of structures. For many engineers, the most conventional approach to protection works (buildings and bridges) the effects of earthquakes is to increase rigidity. This approach is not always effective, especially when there is a context that favors the phenomenon of resonance and amplification of seismic forces. Therefore, the field of earthquake engineering has made significant inroads, among others catalyzed by the development of computational techniques in computer form and the use of powerful test facilities. This has led to the emergence of several innovative technologies, such as the introduction of special devices insulation between infrastructure and superstructure. This approach, commonly known as "seismic isolation," to absorb the significant efforts without the structure is damaged and thus ensuring the protection of lives and property. In addition, the restraints to the construction by the ground shaking are located mainly at the supports. With these moves, the natural period of construction is increasing, and seismic loads are reduced. Thus, there is an attenuation of the seismic movement. Likewise, the insulation of the base mechanism may be used in combination with earthquake dampers in order to control the deformation of the insulation system and the absolute displacement of the superstructure located above the isolation interface. On the other hand, only can use these earthquake dampers to reduce the oscillation amplitudes and thus reduce seismic loads. The use of damping devices represents an effective solution for the rehabilitation of existing structures. Given all these acceleration reducing means considered passive, much research has been conducted for several years to develop an active control system of the response of buildings to earthquakes.

Keywords: earthquake, building, seismic forces, displacement, resonance, response.

Procedia PDF Downloads 60
849 Seismotectonics and Seismology the North of Algeria

Authors: Djeddi Mabrouk

Abstract:

The slow coming together between the Afro-Eurasia plates seems to be the main cause of the active deformation in the whole of North Africa which in consequence come true in Algeria with a large zone of deformation in an enough large limited band, southern through Saharan atlas and northern through tell atlas. Maghrebin and Atlassian Chain along North Africa are the consequence of this convergence. In junction zone, we have noticed a compressive regime NW-SE with a creases-faults structure and structured overthrust. From a geological point of view the north part of Algeria is younger then Saharan platform, it’s changing so unstable and constantly in movement, it’s characterized by creases openly reversed, overthrusts and reversed faults, and undergo perpetually complex movement vertically and horizontally. On structural level the north of Algeria it's a part of erogenous alpine peri-Mediterranean and essentially the tertiary age It’s spread from east to the west of Algeria over 1200 km.This oogenesis is extended from east to west on broadband of 100 km.The alpine chain is shaped by 3 domains: tell atlas in north, high plateaus in mid and Saharan atlas in the south In extreme south we find the Saharan platform which is made of Precambrian bedrock recovered by Paleozoic practically not deformed. The Algerian north and the Saharan platform are separated by an important accident along of 2000km from Agadir (Morocco) to Gabes (Tunisian). The seismic activity is localized essentially in a coastal band in the north of Algeria shaped by tell atlas, high plateaus, Saharan atlas. Earthquakes are limited in the first 20km of the earth's crust; they are caused by movements along faults of inverted orientation NE-SW or sliding tectonic plates. The center region characterizes Strong Earthquake Activity who locates mainly in the basin of Mitidja (age Neogene).The southern periphery (Atlas Blidéen) constitutes the June, more Important seism genic sources in the city of Algiers and east (Boumerdes region). The North East Region is also part of the tellian area, but it is characterized by a different strain in other parts of northern Algeria. The deformation is slow and low to moderate seismic activity. Seismic activity is related to the tectonic-slip earthquake. The most pronounced is that of 27 October 1985 (Constantine) of seismic moment magnitude Mw = 5.9. North-West region is quite active and also artificial seismic hypocenters which do not exceed 20km. The deep seismicity is concentrated mainly a narrow strip along the edge of Quaternary and Neogene basins Intra Mountains along the coast. The most violent earthquakes in this region are the earthquake of Oran in 1790 and earthquakes Orléansville (El Asnam in 1954 and 1980).

Keywords: alpine chain, seismicity north Algeria, earthquakes in Algeria, geophysics, Earth

Procedia PDF Downloads 391
848 Climate Change, Multiple Stressors, and Livelihoods: A Search for Communities Understanding, Vulnerability, and Adaptation in Zanzibar Islands

Authors: Thani R. Said

Abstract:

There is a wide concern on the academic literatures that the world is on course to experience “severe and pervasive” negative impacts from climate change unless it takes rapid action to slash its greenhouse gas emissions. The big threat however, is more belligerent in the third world countries, small islands states in particular. Most of the academic literatures claims that the livelihoods, economic and ecological landscapes of most of the coastal communities are into serious danger due to the peril of climate change. However, focusing the climate change alone and paying less intention to the surrounding stressors which sometimes are apparent then the climate change its self has now placed at the greater concern on academic debates. The recently studies have begun to question such narrowed assessment of climate change intervening programs from both its methodological and theoretical perspectives as related with livelihoods and the landscapes of the coastal communities. Looking climate as alone as an ostentatious threat doesn't yield the yield an appropriate mechanisms to address the problem in its totality and tend to provide the partially picture of the real problem striking the majority of the peoples living in the coastal areas of small islands states, Zanzibar in particular. By using the multiples human grounded knowledge approaches, the objective of this study is to go beyond the mere climate change by analyzing other multiples stressors that real challenging and treating the livelihoods, economic and ecological landscapes of the coastal communities through dialectic understanding, vulnerability and adaptive mechanisms at their own localities. To be more focus and to capture the full picture on this study special intention will be given to those areas were climate changes intervening programs have been onto place, the study will further compare and contrast between the two islands communities, Unguja and Pemba taking into account their respective diverse economic and geographical landscapes prevailed.

Keywords: climate change, multiple stressors, livelihoods, vulnerability-adaptation

Procedia PDF Downloads 392
847 The Basics of Cognitive Behavioral Family Therapy and the Treatment of Various Physical and Mental Diseases

Authors: Mahta Mohamadkashi

Abstract:

The family is the most important source of security and health for the people of the society, and at the same time, it is the main field of creating all kinds of social and psychological problems. On the one hand, a family is a natural group with many goals and roles that are important and necessary for all family members. On the other hand, the family is a strong and organized group that recruits the therapist because of the goals that are concealed in its policy and procedures. The relationship between the environment and the family background with mental illnesses has been the focus of various researchers for a long time, and the research and experiments that have been conducted to show that the functioning of the family is related to the mental health of the members of the family. Currently, several theoretical perspectives with different approaches seek to explain and resolve psychological problems and family conflicts that can be mentioned. This research aims to investigate "cognitive-behavioral family therapy" by using the "family therapy" research method which is included the descriptive-analytical method and the method of collecting library information, with special reliance on Persian and Latin books and articles. for considering one of the important approaches of family therapy that we are going which have been known as data and its conditions that also includes requirements and limitations. For this purpose, in the beginning, brief background and introduction about family and family therapy are going to describe, and then the basics of cognitive-behavioral family therapy and the implementation process and various techniques of this approach can go through a big discussion. After that, we will apply this approach in the treatment of various physical and mental diseases in the form of related research, and we will examine the ups and downs of the implementation procedures, limitations, and future directions in this field. In general, This study emphasizes the role of the family system in the occurrence of psychological diseases and disorders and also validates the role of the family system in the treatment of those diseases and disorders. Also, cognitive-behavioral family therapy has been approved as an effective treatment approach for a variety of mental disorders.

Keywords: cognitive-behavioral, family, family therapy, cognitive-behavioral family therapy

Procedia PDF Downloads 83
846 Linguistic Misinterpretation and the Dialogue of Civilizations

Authors: Oleg Redkin, Olga Bernikova

Abstract:

Globalization and migrations have made cross-cultural contacts more frequent and intensive. Sometimes, these contacts may lead to misunderstanding between partners of communication and misinterpretations of the verbal messages that some researchers tend to consider as the 'clash of civilizations'. In most cases, reasons for that may be found in cultural and linguistic differences and hence misinterpretations of intentions and behavior. The current research examines factors of verbal and non-verbal communication that should be taken into consideration in verbal and non-verbal contacts. Language is one of the most important manifestations of the cultural code, and it is often considered as one of the special features of a civilization. The Arabic language, in particular, is commonly associated with Islam and the language and the Arab-Muslim civilization. It is one of the most important markers of self-identification for more than 200 million of native speakers. Arabic is the language of the Quran and hence the symbol of religious affiliation for more than one billion Muslims around the globe. Adequate interpretation of Arabic texts requires profound knowledge of its grammar, semantics of its vocabulary. Communicating sides who belong to different cultural groups are guided by different models of behavior and hierarchy of values, besides that the vocabulary each of them uses in the dialogue may convey different semantic realities and vary in connotations. In this context direct, literal translation in most cases cannot adequately convey the original meaning of the original message. Besides that peculiarities and diversities of the extralinguistic information, such as the body language, communicative etiquette, cultural background and religious affiliations may make the dialogue even more difficult. It is very likely that the so called 'clash of civilizations' in most cases is due to misinterpretation of counterpart's means of discourse such as language, cultural codes, and models of behavior rather than lies in basic contradictions between partners of communication. In the process of communication, one has to rely on universal values rather than focus on cultural or religious peculiarities, to take into account current linguistic and extralinguistic context.

Keywords: Arabic, civilization, discourse, language, linguistic

Procedia PDF Downloads 211
845 Study on Effective Continuous Assessments Methods to Improve Undergraduates English Language Skills

Authors: K. M. R. Siriwardhana

Abstract:

Sri Lanka is a developing country in South Asia which uses English as its second language. Today, most of the university students in Sri Lanka are eagerly exploring knowledge giving special consideration to English as their 2nd Language with the understanding that to climb up the career ladder, English is inevitable both in local and international contexts. However, still a considerable failing rate in English can also be seen among the Sri Lankan undergraduates Further, most of the Sri Lankan universities now practice English as their medium of instructions making English a credited Subject to brighten the future of the Sri Lankan students. Accordingly, in many universities an array of assessments are employed to evaluate undergraduates’ competence in English language. The main objective of this study was to ascertain the effective assessment methods to improve the 2nd language skills of the Sri Lankan university students which also create a more interest in them to learn English. Accordingly, hundred (100) undergraduates were selected as the research sample and the primary data was collected employing a semi structured questionnaire along with class room observations and semi structured interviews. Data was mainly analyzed descriptively employing graphical illustrations. According to the research findings, it was revealed that practical assessments such as oral tests, competitive drama and presentations are more effective in improving their language skills and preferred by the majority of students than written assignments and papers. Further, most of the students have scored better in practical assignments than in the written assignments. Hence, the study concludes that best and the benefited way of improving English language skills of Sri Lankan undergraduates is practical assessments as it gives them the opportunity to apply the language with much confidence and competence in actual situations. Further, the study recommends the language teachers to improve their own skills and creativity in practicing and employing such assessments as it will develop both second language teaching and learning skills. Ultimately, the university graduates will be able to secure their positions internationally as they are well capable in English, the lingua franca of the world.

Keywords: assessments, second language, Sri Lanka, undergraduates

Procedia PDF Downloads 290
844 Effect of Multi-Walled Carbon Nanotubes on Fuel Cell Membrane Performance

Authors: Rabindranath Jana, Biswajit Maity, Keka Rana

Abstract:

The most promising clean energy source is the fuel cell, since it does not generate toxic gases and other hazardous compounds. Again the direct methanol fuel cell (DMFC) is more user-friendly as it is easy to be miniaturized and suited as energy source for automobiles as well as domestic applications and portable devices. And unlike the hydrogen used for some fuel cells, methanol is a liquid that is easy to store and transport in conventional tanks. The most important part of a fuel cell is its membrane. Till now, an overall efficiency for a methanol fuel cell is reported to be about 20 ~ 25%. The lower efficiency of the cell may be due to the critical factors, e.g. slow reaction kinetics at the anode and methanol crossover. The oxidation of methanol is composed of a series of successive reactions creating formaldehyde and formic acid as intermediates that contribute to slow reaction rates and decreased cell voltage. Currently, the investigation of new anode catalysts to improve oxidation reaction rates is an active area of research as it applies to the methanol fuel cell. Surprisingly, there are very limited reports on nanostructured membranes, which are rather simple to manufacture with different tuneable compositions and are expected to allow only the proton permeation but not the methanol due to their molecular sizing effects and affinity to the membrane surface. We have developed a nanostructured fuel cell membrane from polydimethyl siloxane rubber (PDMS), ethylene methyl co-acrylate (EMA) and multi-walled carbon nanotubes (MWNTs). The effect of incorporating different proportions of f-MWNTs in polymer membrane has been studied. The introduction of f-MWNTs in polymer matrix modified the polymer structure, and therefore the properties of the device. The proton conductivity, measured by an AC impedance technique using open-frame and two-electrode cell and methanol permeability of the membranes was found to be dependent on the f-MWNTs loading. The proton conductivity of the membranes increases with increase in concentration of f-MWNTs concentration due to increased content of conductive materials. Measured methanol permeabilities at 60oC were found to be dependant on loading of f-MWNTs. The methanol permeability decreased from 1.5 x 10-6 cm²/s for pure film to 0.8 x 10-7 cm²/s for a membrane containing 0.5wt % f-MWNTs. This is due to increasing proportion of f-MWNTs, the matrix becomes more compact. From DSC melting curves it is clear that the polymer matrix with f-MWNTs is thermally stable. FT-IR studies show good interaction between EMA and f-MWNTs. XRD analysis shows good crystalline behavior of the prepared membranes. Significant cost savings can be achieved when using the blended films which contain less expensive polymers.

Keywords: fuel cell membrane, polydimethyl siloxane rubber, carbon nanotubes, proton conductivity, methanol permeability

Procedia PDF Downloads 406
843 The Role of Privatization as a Moderator of the Impact of Non-Institutional Factors on the Performance of the Enterprises in Central and Eastern Europe

Authors: Margerita Topalli

Abstract:

In this paper, we analyze the impact of corruption (business environment, informal payments and state capture), crime and tax time, on the enterprise's performance during economic transition in the Central and Eastern Europe and the role of privatization as a moderator. We examine this effect by comparing the performance of the privatized enterprises and the state-owned-enterprises, while controlling for various forms of selection bias. The present study is based on firm-level panel data collected by the BEEPS for 27 transition countries over 2002, 2005, 2007, and 2011. In addition to firm characteristics, BEEPS collects valuable survey information on different forms of corruption, crime, tax time and firm ownership. We estimate the impact of corruption, crime, tax time on the different performance measures (sales, productivity, employment, labor costs and material costs) of the enterprise, whereby we control for firm ownership, with a special focus on the role of the privatization as a moderator. It argues that in general terms, the privatization has positive effects on the performance of enterprises during transition, but these effects are significantly different, depending on the examined performance measure (sales, productivity, employment, labor costs and material costs). When the privatization is effective, the privatized enterprises show a considerable performance improvements, particularly in terms of revenue growth and productivity growth. It also argues that the effects of privatization are different depending on the types of owner (outsider or insider) to whom it gives control. The results show that privatization to insider owners has no significant performance effect.

Keywords: effects of privatization, enterprise performance, state capture, corruption, firm ownership, economic transition, Central and Eastern Europe

Procedia PDF Downloads 311
842 Mapping Social and Natural Hazards: A Survey of Potential for Managed Retreat in the United States

Authors: Karim Ahmed

Abstract:

The purpose of this study was to investigate how factoring the impact of natural disasters beyond flooding would affect managed retreat policy eligibility in the United States. For the study design, a correlation analysis method compared weighted measures of flooding and other natural disasters (e.g., wildfires, tornadoes, heatwaves, etc.) to CBSA Populated areas, the prevalence of cropland, and relative poverty on a county level. The study found that the vast majority of CBSAs eligible for managed retreat programs under a policy inclusive of non-flooding events would have already been covered by flood-only managed retreat policies. However, it is noteworthy that a majority of those counties that are not covered by a flood-only managed retreat policy have high rates of poverty and are either heavily populated and/or agriculturally active. The correlation is particularly strong between counties that are subject to multiple natural hazards and those that have both high rates of relative poverty and cropland prevalence. There is currently no managed retreat policy for agricultural land in the United States despite the environmental implications and food supply chain vulnerabilities related to at-risk cropland. The findings of this study suggest both that such a policy should be created and, when it is, that special attention should be paid to non-flood natural disasters affecting agricultural areas. These findings also reveal that, while current flood-based policies in the United States serve many areas that do need access to managed retreat funding and implementation, other vulnerable areas are overlooked by this approach. These areas are often deeply impoverished and are therefore particularly vulnerable to natural disaster; if and when those disasters do occur, these areas are often less financially prepared to recover or retreat from the disaster’s advance and, due to the limitations of the current policies discussed above, are less able to take the precautionary measures necessary to mitigate their risk.

Keywords: flood, hazard, land use, managed retreat, wildfire

Procedia PDF Downloads 113
841 Global Experiences in Dealing with Biological Epidemics with an Emphasis on COVID-19 Disease: Approaches and Strategies

Authors: Marziye Hadian, Alireza Jabbari

Abstract:

Background: The World Health Organization has identified COVID-19 as a public health emergency and is urging governments to stop the virus transmission by adopting appropriate policies. In this regard, authorities have taken different approaches to cut the chain or controlling the spread of the disease. Now, the questions we are facing include what these approaches are? What tools should be used to implement each preventive protocol? In addition, what is the impact of each approach? Objective: The aim of this study was to determine the approaches to biological epidemics and related prevention tools with an emphasis on COVID-19 disease. Data sources: Databases including ISI web of science, PubMed, Scopus, Science Direct, Ovid, and ProQuest were employed for data extraction. Furthermore, authentic sources such as the WHO website, the published reports of relevant countries, as well as the Worldometer website were evaluated for gray studies. The time-frame of the study was from 1 December 2019 to 30 May 2020. Methods: The present study was a systematic study of publications related to the prevention strategies for the COVID-19 disease. The study was carried out based on the PRISMA guidelines and CASP for articles and AACODS for grey literature. Results: The study findings showed that in order to confront the COVID-19 epidemic, in general, there are three approaches of "mitigation", "active control" and "suppression" and four strategies of "quarantine", "isolation", "social distance" and "lockdown" in both individual and social dimensions to deal with epidemics. Selection and implementation of each approach requires specific strategies and has different effects when it comes to controlling and inhibiting the disease. Key finding: One possible approach to control the disease is to change individual behavior and lifestyle. In addition to prevention strategies, use of masks, observance of personal hygiene principles such as regular hand washing and non-contact of contaminated hands with the face, as well as an observance of public health principles such as sneezing and coughing etiquettes, safe extermination of personal protective equipment, must be strictly observed. Have not been included in the category of prevention tools. However, it has a great impact on controlling the epidemic, especially the new coronavirus epidemic. Conclusion: Although the use of different approaches to control and inhibit biological epidemics depends on numerous variables, however, despite these requirements, global experience suggests that some of these approaches are ineffective. The use of previous experiences in the world, along with the current experiences of countries, can be very helpful in choosing the accurate approach for each country in accordance with the characteristics of that country and lead to the reduction of possible costs at the national and international levels.

Keywords: novel corona virus, COVID-19, approaches, prevention tools, prevention strategies

Procedia PDF Downloads 118
840 Static Test Pad for Solid Rocket Motors

Authors: Svanik Garg

Abstract:

Static Test Pads are stationary mechanisms that hold a solid rocket motor, measuring the different parameters of its operation including thrust and temperature to better calibrate it for launch. This paper outlines a specific STP designed to test high powered rocket motors with a thrust upwards of 4000N and limited to 6500N. The design includes a specific portable mechanism with cost an integral part of the design process to make it accessible to small scale rocket developers with limited resources. Using curved surfaces and an ergonomic design, the STP has a delicately engineered façade/case with a focus on stability and axial calibration of thrust. This paper describes the design, operation and working of the STP and its widescale uses given the growing market of aviation enthusiasts. Simulations on the CAD model in Fusion 360 provided promising results with a safety factor of 2 established and stress limited along with the load coefficient A PCB was also designed as part of the test pad design process to help obtain results, with visual output and various virtual terminals to collect data of different parameters. The circuitry was simulated using ‘proteus’ and a special virtual interface with auditory commands was also created for accessibility and wide-scale implementation. Along with this description of the design, the paper also emphasizes the design principle behind the STP including a description of its vertical orientation to maximize thrust accuracy along with a stable base to prevent micromovements. Given the rise of students and professionals alike building high powered rockets, the STP described in this paper is an appropriate option, with limited cost, portability, accuracy, and versatility. There are two types of STP’s vertical or horizontal, the one discussed in this paper is vertical to utilize the axial component of thrust.

Keywords: static test pad, rocket motor, thrust, load, circuit, avionics, drag

Procedia PDF Downloads 356