Search results for: historical structures
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5681

Search results for: historical structures

1541 The Stereotypical Images of Marginalized Women in the Poetry of Rita Dove

Authors: Wafaa Kamal Isaac

Abstract:

This paper attempts to shed light upon the stereotypical images of marginalized black women as shown through the poetry of Rita Dove. Meanwhile, it explores how stereotypical images held by the society and public perceptions perpetuate the marginalization of black women. Dove is considered one of the most fundamental African-American poets who devoted her writings to explore the problem of identity that confronted marginalized women in America. Besides tackling the issue of black women’s stereotypical images, this paper focuses upon the psychological damage which the black women had suffered from due to their stripped identity. In ‘Thomas and Beulah’, Dove reflects the black woman’s longing for her homeland in order to make up for her lost identity. This poem represents atavistic feelings deal with certain recurrent images, both aural and visual, like the image of Beulah who represents the African-American woman who searches for an identity, as she is being denied and humiliated one in the newly founded society. In an attempt to protest against the stereotypical mule image that had been imposed upon black women in America, Dove in ‘On the Bus with Rosa Parks’ tries to ignite the beaten spirits to struggle for their own rights by revitalizing the rebellious nature and strong determination of the historical figure ‘Rosa Parks’ that sparked the Civil Rights Movement. In ‘Daystar’, Dove proves that black women are subjected to double-edged oppression; firstly, in terms of race as a black woman in an unjust white society that violates her rights due to her black origins and secondly, in terms of gender as a member of the female sex that is meant to exist only to serve man’s needs. Similarly, in the ‘Adolescence’ series, Dove focuses on the double marginalization which the black women had experienced. It concludes that the marginalization of black women has resulted from the domination of the masculine world and the oppression of the white world. Moreover, Dove’s ‘Beauty and the Beast’ investigates the African-American women’s problem of estrangement and identity crisis in America. It also sheds light upon the psychological consequences that resulted from the violation of marginalized women’s identity. Furthermore, this poem shows the black women’s self-debasement, helplessness, and double consciousness that emanate from the sense of uprootedness. Finally, this paper finds out that the negative, debased and inferior stereotypical image held by the society did not only contribute to the marginalization of black women but also silenced and muted their voices.

Keywords: stereotypical images, marginalized women, Rita Dove, identity

Procedia PDF Downloads 147
1540 Predicting Costs in Construction Projects with Machine Learning: A Detailed Study Based on Activity-Level Data

Authors: Soheila Sadeghi

Abstract:

Construction projects are complex and often subject to significant cost overruns due to the multifaceted nature of the activities involved. Accurate cost estimation is crucial for effective budget planning and resource allocation. Traditional methods for predicting overruns often rely on expert judgment or analysis of historical data, which can be time-consuming, subjective, and may fail to consider important factors. However, with the increasing availability of data from construction projects, machine learning techniques can be leveraged to improve the accuracy of overrun predictions. This study applied machine learning algorithms to enhance the prediction of cost overruns in a case study of a construction project. The methodology involved the development and evaluation of two machine learning models: Random Forest and Neural Networks. Random Forest can handle high-dimensional data, capture complex relationships, and provide feature importance estimates. Neural Networks, particularly Deep Neural Networks (DNNs), are capable of automatically learning and modeling complex, non-linear relationships between input features and the target variable. These models can adapt to new data, reduce human bias, and uncover hidden patterns in the dataset. The findings of this study demonstrate that both Random Forest and Neural Networks can significantly improve the accuracy of cost overrun predictions compared to traditional methods. The Random Forest model also identified key cost drivers and risk factors, such as changes in the scope of work and delays in material delivery, which can inform better project risk management. However, the study acknowledges several limitations. First, the findings are based on a single construction project, which may limit the generalizability of the results to other projects or contexts. Second, the dataset, although comprehensive, may not capture all relevant factors influencing cost overruns, such as external economic conditions or political factors. Third, the study focuses primarily on cost overruns, while schedule overruns are not explicitly addressed. Future research should explore the application of machine learning techniques to a broader range of projects, incorporate additional data sources, and investigate the prediction of both cost and schedule overruns simultaneously.

Keywords: cost prediction, machine learning, project management, random forest, neural networks

Procedia PDF Downloads 26
1539 Heating Demand Reduction in Single Family Houses Community through Home Energy Management: Putting Users in Charge

Authors: Omar Shafqat, Jaime Arias, Cristian Bogdan, Björn Palm

Abstract:

Heating constitutes a major part of the overall energy consumption in Sweden. In 2013 heating and hot water accounted for about 55% of the total energy use in the housing sector. Historically, the end users have not been able to make a significant impact on their consumption on account of traditional control systems that do not facilitate interaction and control of the heating systems. However, in recent years internet connected home energy management systems have become increasingly available which allow users to visualize the indoor temperatures as well as control the heating system. However, the adoption of these systems is still in its nascent stages. This paper presents the outcome of a study carried out in a community of single-family houses in Stockholm. Heating in the area is provided through district heating, and the neighbourhood is connected through a local micro thermal grid, which is owned and operated by the local community. Heating in the houses is accomplished through a hydronic system equipped with radiators. The system installed offers the households to control the indoor temperature through a mobile application as well as through a physical thermostat. It was also possible to program the system to, for instance, lower the temperatures during night time and when the users were away. The users could also monitor the indoor temperatures through the application. It was additionally possible to create different zones in the house with their own individual programming. The historical heating data (in the form of billing data) was available for several previous years and has been used to perform quantitative analysis for the study after necessary normalization for weather variations. The experiment involved 30 households out of a community of 178 houses. The area was selected due to uniform construction profile in the area. It was observed that despite similar design and construction period there was a large variation in the heating energy consumption in the area which can for a large part be attributed to user behaviour. The paper also presents qualitative analysis done through survey questions as well as a focus group carried out with the participants. Overall, considerable energy savings were accomplished during the trial, however, there was a considerable variation between the participating households. The paper additionally presents recommendations to improve the impact of home energy management systems for heating in terms of improving user engagement and hence the energy impact.

Keywords: energy efficiency in buildings, energy behavior, heating control system, home energy management system

Procedia PDF Downloads 161
1538 The Impact of the Variation of Sky View Factor on Landscape Degree of Enclosure of Urban Blue and Green Belt

Authors: Yi-Chun Huang, Kuan-Yun Chen, Chuang-Hung Lin

Abstract:

Urban Green Belt and Blue is a part of the city landscape, it is an important constituent element of the urban environment and appearance. The Hsinchu East Gate Moat is situated in the center of the city, which not only has a wealth of historical and cultural resources, but also combines the Green Belt and the Blue Belt qualities at the same time. The Moat runs more than a thousand meters through the vital Green Belt and the Blue Belt in downtown, and each section is presented in different qualities of moat from south to north. The water area and the green belt of surroundings are presented linear and banded spread. The water body and the rich diverse river banks form an urban green belt of rich layers. The watercourse with green belt design lets users have connections with blue belts in different ways; therefore, the integration of Hsinchu East Gate and moat have become one of the unique urban landscapes in Taiwan. The study is based on the fact-finding case of Hsinchu East Gate Moat where situated in northern Taiwan, to research the impact between the SVF variation of the city and spatial sequence of Urban Green Belt and Blue landscape and visual analysis by constituent cross-section, and then comparing the influence of different leaf area index – the variable ecological factors to the degree of enclosure. We proceed to survey the landscape design of open space, to measure existing structural features of the plant canopy which contain the height of plants and branches, the crown diameter, breast-height diameter through access to diagram of Geographic Information Systems (GIS) and on-the-spot actual measurement. The north and south districts of blue green belt areas are divided 20 meters into a unit from East Gate Roundabout as the epicenter, and to set up a survey points to measure the SVF above the survey points; then we proceed to quantitative analysis from the data to calculate open landscape degree of enclosure. The results can be reference for the composition of future river landscape and the practical operation for dynamic space planning of blue and green belt landscape.

Keywords: sky view factor, degree of enclosure, spatial sequence, leaf area indices

Procedia PDF Downloads 545
1537 The Morphogenesis of an Informal Settlement: An Examination of Street Networks through the Informal Development Stages Framework

Authors: Judith Margaret Tymon

Abstract:

As cities struggle to incorporate informal settlements into the fabric of urban areas, the focus has often been on the provision of housing. This study explores the underlying structure of street networks, with the goal of understanding the morphogenesis of informal settlements through the lens of the access network. As the stages of development progress from infill to consolidation and eventually, to a planned in-situ settlement, the access networks retain the form of the core segments; however, a majority of street patterns are adapted to a grid design to support infrastructure in the final upgraded phase. A case study is presented to examine the street network in the informal settlement of Gobabis Namibia as it progresses from its initial stages to a planned, in-situ, and permanently upgraded development. The Informal Development Stages framework of foundation, infill, and consolidation, as developed by Dr. Jota Samper, is utilized to examine the evolution of street networks. Data is gathered from historical Google Earth satellite images for the time period between 2003 and 2022. The results demonstrate that during the foundation through infill stages, incremental changes follow similar patterns, with pathways extended, lengthened, and densified as housing is created and the settlement grows. In the final stage of consolidation, the resulting street layout is transformed to support the installation of infrastructure; however, some elements of the original street patterns remain. The core pathways remain intact to accommodate the installation of infrastructure and the creation of housing plots, defining the shape of the settlement and providing the basis of the urban form. The adaptations, growth, and consolidation of the street network are critical to the eventual formation of the spatial layout of the settlement. This study will include a comparative analysis of findings with those of recent research performed by Kamalipour, Dovey, and others regarding incremental urbanism within informal settlements. Further comparisons will also include studies of street networks of well-established urban centers that have shown links between the morphogenesis of access networks and the eventual spatial layout of the city. The findings of the study can be used to guide and inform strategies for in-situ upgrading and can contribute to the sustainable development of informal settlements.

Keywords: Gobabis Namibia, incremental urbanism, informal development stages, informal settlements, street networks

Procedia PDF Downloads 49
1536 Drastic Increase of Wave Dissipation within Metastructures Having Negative Stiffness Inclusions

Authors: D. Chronopoulos, I. Antoniadis, V. Spitas, D. Koulocheris, V. Polenta

Abstract:

A concept of a simple linear oscillator, incorporating a negative stiffness element is demonstrated to exhibit extraordinary damping properties. This oscillator shares the same overall (static) stiffness, the same mass and the same damping element with a reference classical linear SDOF oscillator. However, it differs from the original SDOF oscillator by appropriately redistributing the component spring stiffness elements and by re-allocating the damping element. Despite the fact that the proposed oscillator incorporates a negative stiffness element, it is designed to be both statically and dynamically stable. Once such an oscillator is optimally designed, it is shown to exhibit an extraordinary apparent damping ratio, which is even several orders of magnitude higher than that of the original SDOF system, especially in cases where the original damping of the SDOF system is low. This damping behavior is not a result of a novel additional extraordinary energy dissipation mechanism, but a result of the phase difference between the positive and the negative stiffness elastic forces, which is in turn a consequence of the proper re-distribution of the stiffness and the damper elements. This fact ensures that an adequate level of elastic forces exists throughout the entire frequency range, able to counteract the inertial and the excitation forces. Next, Acoustic or Phononic Meta-materials are considered, in which one atom is replaced by the concept of the above simple linear oscillator. The results indicate that not only the damping of the meta-material verifies and exceeds the one expected from the so-called "meta-damping" behavior, but also that the band gap of the meta-material can be significantly increased.

Keywords: wave propagation, periodic structures, wave damping, mechanical engineering

Procedia PDF Downloads 348
1535 Development of Orthogonally Protected 2,1':4,6-Di-O-Diisopropylidene Sucrose as the Versatile Intermediate for Diverse Synthesis of Phenylpropanoid Sucrose Esters

Authors: Li Lin Ong, Duc Thinh Khong, Zaher M. A. Judeh

Abstract:

Phenylpropanoid sucrose esters (PSEs) are natural compounds found in various medicinal plants which exhibit important biological activities such as antiproliferation and α- and β-glucosidase inhibitory activities. Despite their potential as new therapeutics, total synthesis of PSEs has been very limited as their inherent structures contain one or more (substituted) cinnamoyl groups randomly allocated on the sucrose core via ester linkage. Since direct acylation of unprotected sucrose would be complex and tedious due to the presence of eight free hydroxyl groups, partially protected 2,1’:4,6-di-O-diisopropylidene sucrose was used as the starting material instead. However, similar reactivity between the remaining four hydroxyl groups still pose a challenge in the total synthesis of PSEs as the lack of selectivity can restrict customisation where acylation at specific OH is desired. To overcome this problem, a 4-step orthogonal protection scheme was developed. In this scheme, the remaining four hydroxyl groups on 2,1’:4,6-di-O-diisopropylidene sucrose, 6’-OH, 3’-OH, 4’-OH, and 3-OH, were protected with different protecting groups with an overall yield of > 40%. This orthogonally protected intermediate would provide a convenient and divergent access to a wider range of natural and synthetic PSEs as (substituted) cinnamoyl groups can be selectively introduced at desired positions. Using this scheme, three different series of monosubstituted PSEs were successfully synthesized where (substituted) cinnamoyl groups were introduced selectively at O-3, O-3’, and O-4’ positions, respectively. The expanded library of PSEs would aid in structural-activity relationship study of PSEs for identifying key components responsible for their biological activities.

Keywords: orthogonal protection, phenylpropanoid sucrose esters, selectivity, sucrose

Procedia PDF Downloads 145
1534 Using Non-Negative Matrix Factorization Based on Satellite Imagery for the Collection of Agricultural Statistics

Authors: Benyelles Zakaria, Yousfi Djaafar, Karoui Moussa Sofiane

Abstract:

Agriculture is fundamental and remains an important objective in the Algerian economy, based on traditional techniques and structures, it generally has a purpose of consumption. Collection of agricultural statistics in Algeria is done using traditional methods, which consists of investigating the use of land through survey and field survey. These statistics suffer from problems such as poor data quality, the long delay between collection of their last final availability and high cost compared to their limited use. The objective of this work is to develop a processing chain for a reliable inventory of agricultural land by trying to develop and implement a new method of extracting information. Indeed, this methodology allowed us to combine data from remote sensing and field data to collect statistics on areas of different land. The contribution of remote sensing in the improvement of agricultural statistics, in terms of area, has been studied in the wilaya of Sidi Bel Abbes. It is in this context that we applied a method for extracting information from satellite images. This method is called the non-negative matrix factorization, which does not consider the pixel as a single entity, but will look for components the pixel itself. The results obtained by the application of the MNF were compared with field data and the results obtained by the method of maximum likelihood. We have seen a rapprochement between the most important results of the FMN and those of field data. We believe that this method of extracting information from satellite data leads to interesting results of different types of land uses.

Keywords: blind source separation, hyper-spectral image, non-negative matrix factorization, remote sensing

Procedia PDF Downloads 408
1533 Traditionalism and Modernity in Seoul’s Urban Planning for the Disabled

Authors: Helena Park

Abstract:

For the last three decades, Seoul has experienced an exponential increase in population and concomitant rapid urbanization. With such development, Korea adopted a predominantly Western style of architecture but still based the structures on Korea’s traditionalism and Confucian precepts of pung su (feng shui). While Korean urban planning is focusing on balancing out the modernism and traditionalism in its city architecture, particularly in and landmark sites like The Seoul N Tower and Gyeongbok Palace, the accessibility and convenience concerns of minorities in social groups like the disabled are habitually disregarded. With the implementations of ramps and elevators, the welfare of all citizens seemed to improve. According to the dictates of traditional Korean culture, it was crucial for those construed as “disabled” or “underprivileged” to feel natural in the city of Seoul, which is planned and built with the background aesthetic theory of being harmonized with nature. It was interesting and also alarming to see the extent to which Korean landmarks were lacking facilities for the disabled throughout the city. Standards set by the Ministry of Health and Welfare and the Seoul Metropolitan City insist that buildings accommodate the needs of the disabled as well as the non-disabled equally, but it was hard to find buildings in Seoul - old or new - that fulfilled all the requirements. If fulfilled, some of the facilities were hard to find or not well maintained. There is thus a serious concern for planning reform in connection with Seoul’s 2030 Urban Plan. This paper argues that alternative planning could better integrate Korea’s traditionalist architecture and concepts of pung su rather than insist on the necessity of Western-style modernism as the sole modality for achieving accessibility for the disabled in Korea.

Keywords: accessibility, architecture of Seoul , Pung Su (Feng Shui), traditionalism, modernism in Seoul

Procedia PDF Downloads 218
1532 The Effect of Grading Characteristics on the Shear Strength and Mechanical Behavior of Granular Classes of Sand-Silt

Authors: Youssouf Benmeriem

Abstract:

Shear strength of sandy soils has been considered as the important parameter to study the stability of different civil engineering structures when subjected to monotonic, cyclic and earthquake loading conditions. The proposed research investigated the effect of grading characteristics on the shear strength and mechanical behavior of granular classes of sands mixed with silt in loose and dense states (Dr = 15% and 90%). The laboratory investigation aimed at understanding the extent or degree at which shear strength of sand-silt mixture soil is affected by its gradation under static loading conditions. For the purpose of clarifying and evaluating the shear strength characteristics of sandy soils, a series of Casagrande shear box tests were carried out on different reconstituted samples of sand-silt mixtures with various gradations. The soil samples were tested under different normal stresses (100, 200 and 300 kPa). The results from this laboratory investigation were used to develop insight into the shear strength response of sand and sand-silt mixtures under monotonic loading conditions. The analysis of the obtained data revealed that the grading characteristics (D10, D50, Cu, ESR, and MGSR) have significant influence on the shear strength response. It was found that shear strength can be correlated to the grading characteristics for the sand-silt mixture. The effective size ratio (ESR) and mean grain size ratio (MGSR) appear as pertinent parameters to predict the shear strength response of the sand-silt mixtures for soil gradation under study.

Keywords: grading characteristics, granular classes of sands, mechanical behavior, sand-silt, shear strength

Procedia PDF Downloads 372
1531 Ethiopia as a Tourist Destination: An Exploration of Italian Tourists’ Market Demand

Authors: Frezer Okubay Weldegebriel

Abstract:

The tourism sector in Ethiopia plays a significant role in the national economy. The government is granting its pledge and readiness to develop this sector through various initiatives since to eradicate poverty and encourage economic development of the country is one of the Millennium Development plans. The tourism sector has been identified as one of the priority economic sectors by many countries, and the Government of Ethiopia has planned to make Ethiopia among the top five African destinations by 2020. Nevertheless, the international tourism demand for Ethiopia currently lags behind other African countries such as South Africa, Egypt, Morocco, Tanzania, and Kenya. Meanwhile, the number of international tourists’ arrival in Ethiopia is recently increasing even if it cannot be competitive with other African countries. Therefore, to offer demand-driven tourism products, the Ethiopian government, Tourism planners, Tour & Travel operators need to understand the important factors, which affect international tourists’ decision to visit Ethiopian destinations. This study was intended to analyze Italian Tourists Demand towards Ethiopian destination. The researcher aimed to identify the demand for Italian tourists’ preference to Ethiopian destinations comparing to the top East African countries. This study uses both qualitative and quantitative research methodology, and the data is manipulating through primary data collection method using questionnaires, interviews, and secondary data by reviewing books, journals, magazines, past researches, and websites. An active and potential Italian tourist cohort, five well-functioning tour operators based in Ethiopia for Italian tourists and professionals from Ethiopian Ministry of Tourism and Culture participated. Based on the analysis of the data collected through the questionnaire, interviews, and reviews of different materials, the study disclosed that the majority of Italian tourists have a high demand on Ethiopian Tourist destination. Historical and cultural interest, safety and security, the hospitality of the people and affordable accommodation coast are the main reason for them. However, some Italian tourists prefer to visit Kenya, Tanzania, and Uganda due to the fact that they are fascinated by adventure, safari and beaches, while Ethiopia cannot provide these attractions. Most Italian tourists have little information and practical experiences on Ethiopian tourism possibilities via a tour and travel companies. Moreover, the insufficient marketing campaign and promotion by Ethiopian Government and Ministry of Tourism could also contribute to the failure of Ethiopian tourism.

Keywords: The demand of Italian tourists, Ethiopia economy, Ethiopia tourism destination, promoting Ethiopia tourism

Procedia PDF Downloads 188
1530 A Machine Learning Approach for Efficient Resource Management in Construction Projects

Authors: Soheila Sadeghi

Abstract:

Construction projects are complex and often subject to significant cost overruns due to the multifaceted nature of the activities involved. Accurate cost estimation is crucial for effective budget planning and resource allocation. Traditional methods for predicting overruns often rely on expert judgment or analysis of historical data, which can be time-consuming, subjective, and may fail to consider important factors. However, with the increasing availability of data from construction projects, machine learning techniques can be leveraged to improve the accuracy of overrun predictions. This study applied machine learning algorithms to enhance the prediction of cost overruns in a case study of a construction project. The methodology involved the development and evaluation of two machine learning models: Random Forest and Neural Networks. Random Forest can handle high-dimensional data, capture complex relationships, and provide feature importance estimates. Neural Networks, particularly Deep Neural Networks (DNNs), are capable of automatically learning and modeling complex, non-linear relationships between input features and the target variable. These models can adapt to new data, reduce human bias, and uncover hidden patterns in the dataset. The findings of this study demonstrate that both Random Forest and Neural Networks can significantly improve the accuracy of cost overrun predictions compared to traditional methods. The Random Forest model also identified key cost drivers and risk factors, such as changes in the scope of work and delays in material delivery, which can inform better project risk management. However, the study acknowledges several limitations. First, the findings are based on a single construction project, which may limit the generalizability of the results to other projects or contexts. Second, the dataset, although comprehensive, may not capture all relevant factors influencing cost overruns, such as external economic conditions or political factors. Third, the study focuses primarily on cost overruns, while schedule overruns are not explicitly addressed. Future research should explore the application of machine learning techniques to a broader range of projects, incorporate additional data sources, and investigate the prediction of both cost and schedule overruns simultaneously.

Keywords: resource allocation, machine learning, optimization, data-driven decision-making, project management

Procedia PDF Downloads 23
1529 Interaction Evaluation of Silver Ion and Silver Nanoparticles with Dithizone Complexes Using DFT Calculations and NMR Analysis

Authors: W. Nootcharin, S. Sujittra, K. Mayuso, K. Kornphimol, M. Rawiwan

Abstract:

Silver has distinct antibacterial properties and has been used as a component of commercial products with many applications. An increasing number of commercial products cause risks of silver effects for human and environment such as the symptoms of Argyria and the release of silver to the environment. Therefore, the detection of silver in the aquatic environment is important. The colorimetric chemosensor is designed by the basic of ligand interactions with a metal ion, leading to the change of signals for the naked-eyes which are very useful method to this application. Dithizone ligand is considered as one of the effective chelating reagents for metal ions due to its high selectivity and sensitivity of a photochromic reaction for silver as well as the linear backbone of dithizone affords the rotation of various isomeric forms. The present study is focused on the conformation and interaction of silver ion and silver nanoparticles (AgNPs) with dithizone using density functional theory (DFT). The interaction parameters were determined in term of binding energy of complexes and the geometry optimization, frequency of the structures and calculation of binding energies using density functional approaches B3LYP and the 6-31G(d,p) basis set. Moreover, the interaction of silver–dithizone complexes was supported by UV–Vis spectroscopy, FT-IR spectrum that was simulated by using B3LYP/6-31G(d,p) and 1H NMR spectra calculation using B3LYP/6-311+G(2d,p) method compared with the experimental data. The results showed the ion exchange interaction between hydrogen of dithizone and silver atom, with minimized binding energies of silver–dithizone interaction. However, the result of AgNPs in the form of complexes with dithizone. Moreover, the AgNPs-dithizone complexes were confirmed by using transmission electron microscope (TEM). Therefore, the results can be the useful information for determination of complex interaction using the analysis of computer simulations.

Keywords: silver nanoparticles, dithizone, DFT, NMR

Procedia PDF Downloads 196
1528 Application Research on Large Profiled Statues of Steel-Concrete Composite Shear Wall

Authors: Zhao Cai-qi, Ma Jun

Abstract:

Twin steel plates-concrete composite shear walls are composed of a pair of steel plate layers and a concrete layer sandwiched between them, which have the characteristics of both reinforced concrete shear walls and steel plate shear walls. Twin steel plates-composite shear walls contain very high ultimate bearing capacity and ductility, which have great potential to be applied in the super high-rise buildings and special structures. In this paper, we analyzed the basic characteristics and stress mechanism of the twin steel plates-composite shear walls. Specifically, we analyzed the effects of the steel plate thickness, wall thickness and concrete strength on the bearing capacity of the twin steel plates-composite shear walls. The analysis results indicate that:(1)the initial shear stiffness and ultimate shear-carrying capacity is not significantly affected by the thickness of concrete wall but by the class of concrete,(2)both factors significantly impact the shear distribution of the shear walls in ultimate shear-carrying capacity. The technique of twin steel plates-composite shear walls has been successfully applied in the construction of a 88-meter Huge Statue of Buddha located in Hunan Province, China. The analysis results and engineering experiences showed that the twin steel plates-composite shear walls have great potential for future research and applications.

Keywords: twin steel plates-concrete composite shear wall, huge statue of Buddha, shear capacity, initial lateral stiffness, overturning moment bearing

Procedia PDF Downloads 390
1527 Towards an African Model: A Survey of Social Enterprises in South Africa

Authors: Kerryn Krige, Kerrin Myers

Abstract:

Social entrepreneurship offers the opportunity to simultaneously address both social and economic inequality in South Africa. Its appeal across racial groups, its attractiveness to young people, its applicability in rural and peri-urban markets, and its acceleration in middle income, large-business economies suits the South African context. However, the potential to deliver much-needed developmental benefits has not been realised because the social entrepreneurship debate lacks evidence as to who social entrepreneurs are, their goals and operations and the socio-economic results they achieve. As a result, policy development has been stunted, and legislative barriers and red tape remain. Social entrepreneurs are isolated from the mainstream economy, and struggle to access funding because of limitations in legislative and organisational structures. The objective of the study is to strengthen the ecosystem for social entrepreneurship in South Africa by producing robust, policy-rich information from and about social enterprises currently in operation across the country. The study employs a quantitative survey methodology, using online and telephonic data collection methods. A purposive sample of 1000 social enterprises was included in the first large-scale study of social entrepreneurship in South Africa. The results offer deep insight into the characteristics of social enterprises; the activities they undertake and the markets they serve; their modes of operation and funding sources as well as key challenges and support systems. The results contribute towards developing a model of social enterprise in the African context.

Keywords: social enterprise, key characteristics, challenges and enablers, towards an African model

Procedia PDF Downloads 292
1526 Thermodynamic and Spectroscopic Investigation of Binary 2,2-Dimethyl-1-Propanol+ CO₂ Gas Hydrates

Authors: Seokyoon Moon, Yun-Ho Ahn, Heejoong Kim, Sujin Hong, Yunseok Lee, Youngjune Park

Abstract:

Gas hydrate is a non-stoichiometric crystalline compound consisting of host water-framework and low molecular weight guest molecules. Small gaseous molecules such as CH₄, CO₂, and N₂ can be captured in the host water framework lattices of the gas hydrate with specific temperature and pressure conditions. The three well-known crystal structures of structure I (sI), structure II (sII), and structure H (sH) are determined by the size and shape of guest molecules. In this study, we measured the phase equilibria of binary (2,2-dimethyl-1-propanol + CO₂, CH₄, N₂) hydrates to explore their fundamental thermodynamic characteristics. We identified the structure of the binary gas hydrate by employing synchrotron high-resolution powder diffraction (HRPD), and the guest distributions in the lattice of gas hydrate were investigated via dispersive Raman and ¹³C solid-state nuclear magnetic resonance (NMR) spectroscopies. The end-to-end distance of 2,2-dimethyl-1-propanol was calculated to be 7.76 Å, which seems difficult to be enclathrated in large cages of sI or sII. However, due to the flexibility of the host water framework, binary hydrates of sI or sII types can be formed with the help of small gas molecule. Also, the synchrotron HRPD patterns revealed that the binary hydrate structure highly depends on the type of help gases; a cubic Fd3m sII hydrate was formed with CH₄ or N₂, and a cubic Pm3n sI hydrate was formed with CO₂. Interestingly, dispersive Raman and ¹³C NMR spectra showed that the unique tuning phenomenon occurred in binary (2,2-dimethyl-1-propanol + CO₂) hydrate. By optimizing the composition of NPA, we can achieve both thermodynamic stability and high CO₂ storage capacity for the practical application to CO₂ capture.

Keywords: clathrate, gas hydrate, neopentyl alcohol, CO₂, tuning phenomenon

Procedia PDF Downloads 226
1525 Green approach of Anticorrosion Coating of Steel Based on Polybenzoxazine/Henna Nanocomposites

Authors: Salwa M. Elmesallamy, Ahmed A. Farag, Magd M. Badr, Dalia S. Fathy, Ahmed Bakry, Mona A. El-Etre

Abstract:

The term green environment is an international trend. It is become imperative to treat the corrosion of steel with a green coating to protect the environment. From the potential adverse effects of the traditional materials.A series of polybenzoxazine/henna composites (PBZ/henna), with different weight percent (3,5, and 7 wt % (of henna), were prepared for corrosion protection of carbon steel. The structures of the prepared composites were verified using FTIR analysis. The mechanical properties of the resins, such as adhesion, hardness, binding, and tensile strength, were also measured. It was found that the tensile strength increases by henna loading up to 25% higher than the tidy resin. The thermal stability was investigated by thermogravimetric analysis (TGA) the loading of lawsone (henna) molecules into the PBZ matrix increases the thermal stability of the composite. UV stability was tested by the UV weathering accelerator to examine the possibility that henna can also act as an aging UV stabilizer. The effect of henna content on the corrosion resistance of composite coatings was tested using potentiostatic polarization and electrochemical spectroscopy. The presence of henna in the coating matrix enhances the protection efficiency of polybenzoxazine coats. Increasing henna concentration increases the protection efficiency of composites. The quantum chemical calculations for polybenzoxazine/henna composites have resulted that the highest corrosion inhibition efficiency, has the highest EHOMO and lowest ELUMO; which is in good agreement with results obtained from experiments.

Keywords: polybenzoxazine, corrosion, green chemistry, carbon steel

Procedia PDF Downloads 87
1524 Sustainable Practices through Organizational Internal Factors among South African Construction Firms

Authors: Oluremi I. Bamgbade, Oluwayomi Babatunde

Abstract:

Governments and nonprofits have been in the support of sustainability as the goal of businesses especially in the construction industry because of its considerable impacts on the environment, economy, and society. However, to measure the degree to which an organisation is being sustainable or pursuing sustainable growth can be difficult as a result of the clear sustainability strategy required to assume their commitment to the goal and competitive advantage. This research investigated the influence of organisational culture and organisational structure in achieving sustainable construction among South African construction firms. A total of 132 consultants from the nine provinces in South Africa participated in the survey. The data collected were initially screened using SPSS (version 21) while Partial Least Squares Structural Equation Modeling (PLS-SEM) algorithm and bootstrap techniques were employed to test the hypothesised paths. The empirical evidence also supported the hypothesised direct effects of organisational culture and organisational structure on sustainable construction. Similarly, the result regarding the relationship between organisational culture and organisational structure was supported. Therefore, construction industry can record a considerable level of construction sustainability and establish suitable cultures and structures within the construction organisations. Drawing upon organisational control theory, these findings supported the view that these organisational internal factors have a strong contingent effect on sustainability adoption in construction project execution. The paper makes theoretical, practical and methodological contributions within the domain of sustainable construction especially in the context of South Africa. Some limitations of the study are indicated, suggesting opportunities for future research.

Keywords: organisational culture, organisational structure, South African construction firms, sustainable construction

Procedia PDF Downloads 273
1523 Worldwide Prosperity Through Democracy: A Cross-country Examination of the Impact of Democratization on Human Development from 1990

Authors: Martin Plener

Abstract:

Developmental and democratization research has a long tradition of focusing on the relationship between democratization and economic development. However, recent studies have shown that economic development is not adequate to measure the actual living conditions of civilian people. In consequence, it is unclear if a democratization process helps to improve people’s quality of life. This work addresses this issue by investigating the influence of democratization on the Human Development Index (HDI) created by the United Nations. The main objective is to study the relationship between democracy and human development and whether democratization positively impacts the living conditions of the population over time. The main mechanism which supports a positive impact is that democratic structures promote participation and political involvement of people from all social classes resulting in a better articulation of interests and thus accountability to the government. To study this issue, a panel regression with Fixed-Effects is conducted. By that, it is examined if democracy has a positive impact on the HDI (Hypothesis 1) and secondly if the same effect weakens in more developed democracies compared to less developed democracies (Hypothesis 2). The results do not reveal a direct positive relationship between the democratization of a country and its development of the HDI, not supporting H1 which denies the first hypothesis. In contrast to the assumption of H2, the effect of democratization on human development seems to be negatively correlated in countries in which democracy is barely developed. Therefore, both hypotheses must be discarded. The results indicate rather a positive correlation between economic development on human development. Therefore, the impact of democracy on the well-being of countries’ citizens needs to be reinvestigated in order to create a better understanding of how improved human development can be achieved.

Keywords: democracy, human development, modernization theory, HDI, TSCS

Procedia PDF Downloads 65
1522 Comparative Performance Study of Steel Plate Shear Wall with Reinforced Concrete Shear Wall

Authors: Amit S. Chauhan, S. Mandal

Abstract:

The structural response of shear walls subjected to various types of loads is difficult to predict precisely. They are incorporated in buildings to resist lateral forces and support the gravity loads. The steel plate shear walls (SPSWs) are used as lateral load resisting systems for buildings and acts as an alternative to reinforced concrete shear walls (RCSWs). This paper compares the behavior of SPSW with the RCSW incorporated in a building frame having G+6 storey, located in Zone III, using the technique of Equivalent Static Method (ESM) as per Indian Standard Criteria For Earthquake Resistant Design of Structures IS 1893:2002. This paper intends to evaluate several parameters such as lateral displacement at tip, inter-storey drift, weight of steel and volume of concrete with the alteration of the shear wall with respect to different types viz., SPSW and RCSW. The strip model employed in this study is a widely accepted analytical tool for SPSW analysis. SPSW can be modelled as truss members by using a series of diagonal tension strips positioned at 45-degree angles. In this paper, by replacing the SPSWs with the tension strips, the G+6 building has been analyzed using STAAD.Pro V8i. Based on the present study, it can be concluded that structure with SPSWs is much better then structure with RCSWs.

Keywords: equivalent static method, inter-storey drift, lateral displacement, Steel plate shear wall, strip model

Procedia PDF Downloads 232
1521 Effect of Dual Wavelength Light Exposure on Regeneration of Dugesia dorotocephala

Authors: Zayedali Shaikh

Abstract:

Increasingly now more than ever, UV damage brings with it a litany of minor deformities that can range from mild lesions and discoloring to cataracts and blindness. Pluripotent stem cells in planaria and human skin can be used to treat wounds and skin damage, with the primary limitations being inadequate growth factors. Photobiomodulation therapy in the form of low-intensity red light therapy has been proven to provide helpful benefits in the healing of skin that displays some of the symptoms of UV damage, such as burns and lesions, along with stimulating the proliferation of stem cells in recellularizing tissue. This paper puts forth an alternate means by which to treat the effects of UV damage using the freshwater planarian model system, Dugesia dorotocephala, known for its regenerative abilities and abundance of pluripotent stem cells, which allow for the rapid growth and repair of missing or damaged structures. Our work consisted of exposing planaria to different types of light: red light, blue light, white light, darkness, red and blue light together, UV light, and finally, red and UV light together. The primary focus of this research was on the red and UV lights, with six controls acting as metrics to compare our findings. Through computer-assisted morphological analysis, the results show that there is no significant difference in the rates of regeneration of planaria treated with simultaneous exposure to red and UV light versus planaria in darkness (p > .05), a representation of their preferred natural habitat. Our research suggests the viability of red-light therapy in actively combating UV damage and expediting the growth of epidermal stem cells by acting as another growth factor.

Keywords: regenerative medicine, stem cells, planaria, photobiomodulation

Procedia PDF Downloads 61
1520 Sustainable Radiation Curable Palm Oil-Based Products for Advanced Materials Applications

Authors: R. Tajau, R. Rohani, M. S. Alias, N. H. Mudri, K. A. Abdul Halim, M. H. Harun, N. Mat Isa, R. Che Ismail, S. Muhammad Faisal, M. Talib, M. R. Mohamed Zin

Abstract:

Bio-based polymeric materials are increasingly used for a variety of applications, including surface coating, drug delivery systems, and tissue engineering. These polymeric materials are ideal for the aforementioned applications because they are derived from natural resources, non-toxic, low-cost, biocompatible, and biodegradable, and have promising thermal and mechanical properties. The nature of hydrocarbon chains, carbon double bonds, and ester bonds allows various sources of oil (edible), such as soy, sunflower, olive, and oil palm, to fine-tune their particular structures in the development of innovative materials. Palm oil can be the most eminent raw material used for manufacturing new and advanced natural polymeric materials involving radiation techniques, such as coating resins, nanoparticles, scaffold, nanotubes, nanocomposites, and lithography for different branches of the industry in countries where oil palm is abundant. The radiation technique is among the most versatile, cost-effective, simple, and effective methods. Crosslinking, reversible addition-fragmentation chain transfer (RAFT), polymerisation, grafting, and degradation are among the radiation mechanisms. Exposure to gamma, EB, UV, or laser irradiation, which are commonly used in the development of polymeric materials, is used in these mechanisms. Therefore, this review focuses on current radiation processing technologies for the development of various radiation-curable bio-based polymeric materials with a promising future in biomedical and industrial applications. The key focus of this review is on radiation curable palm oil-based products, which have been published frequently in recent studies.

Keywords: palm oil, radiation processing, surface coatings, VOC

Procedia PDF Downloads 175
1519 Celebrating Community Heritage through the People’s Collection Wales: A Case Study in the Development of Collecting Traditions and Engagement

Authors: Gruffydd E. Jones

Abstract:

The world’s largest collection of historical, cultural, and heritage material is unarchived and undocumented in the hands of the public. Not only does this material represent the missing collections in heritage sector archives today, but it is also the key to providing a diverse range of communities with the means to express their history in their own words and to celebrate their unique, personal heritage. The People’s Collection Wales (PCW) acts as a platform on which the heritage of Wales and her people can be collated and shared, at the heart of which is a thriving community engagement programme across a network of museums, archives, and libraries. By providing communities with the archival skillset commonly employed throughout the heritage sector, PCW enables local projects, societies, and individuals to express their understanding of local heritage with their own voices, empowering communities to embrace their diverse and complex identities around Wales. Drawing on key examples from the project’s history, this paper will demonstrate the successful way in which museums have been developed as hubs for community engagement where the public was at the heart of collection and documentation activities, informing collection and curatorial policies to benefit both the institute and its local community. This paper will also highlight how collections from marginalised, under-represented, and minority communities have been published and celebrated extensively around Wales, including adoption by the education system in classrooms today. Any activity within the heritage sector, whether of collection, preservation, digitisation, or accessibility, should be considerate of community engagement opportunities not only to remain relevant but in order to develop as community hubs, pivots around which local heritage is supported and preserved. Attention will be drawn to our digitisation workflow, which, through training and support from museums and libraries, has allowed the public not only to become involved but to actively lead the contemporary evolution of documentation strategies in Wales. This paper will demonstrate how the PCW online access archive is promoting museum collections, encouraging user interaction, and providing an invaluable platform on which a broader community can inform, preserve and celebrate their cultural heritage through their own archival material too. The continuing evolution of heritage engagement depends wholly on placing communities at the heart of the sector, recognising their wealth of cultural knowledge, and developing the archival skillset necessary for them to become archival practitioners of their own.

Keywords: social history, cultural heritage, community heritage, museums, archives, libraries, community engagement, oral history, community archives

Procedia PDF Downloads 78
1518 Hospitality and Migration within the Canadian Social Fabric: Guest and Host Factors in Manitoba

Authors: Nathalie Piquemal, Faiçal Zellama, Bathélemy Bolivar, Leyla Sall

Abstract:

Canada defines itself as a country of immigration and a multicultural nation, ideologically, politically and programmatically (in terms of its integration practices). As such, principles of hospitality may seem, at first glance, incontestable, given the convergence of the views of the majority of Canadian politicians on the need to welcome, each year, a significant number of immigrants and to offer them the hospitality that facilitates their transition to Canadian citizenship. However, immigrants are welcomed in a Canadian societal context in which power and resources are unevenly distributed, resulting in complex social relationships between hosts and newcomers. Qualitative data obtained from newcomers in Winnipeg, Manitoba, Canada, focuses on experiences of hospitality, with special attention to host-guest social and power dynamics, contested policies on foreign credential and micro spaces of belongingin a multicultural context. The act of welcoming a newcomer is inherently shaped by both macropolitical structures and everyday relational practices that can lead to experiences of belonging, marginalisation, empowerment and/or disempowerment depending on economic agenda, humanitarian and humanistic orientations. We first explore the extent to which immigrants experience hospitality in relation to unequal distribution of power and resources as well as cultural discontinuities. We then examine ways in which immigrants have been able to find sanctuaries of hospitality within their own ethnocultural communities. Finally, we discuss the complexity of hospitality in a multicultural context and offer critical insights on host factors that may produce, develop and nurture hospitable environments.

Keywords: migration, hospitality, diversity, culture, race

Procedia PDF Downloads 99
1517 Behavior of the RC Slab Subjected to Impact Loading According to the DIF

Authors: Yong Jae Yu, Jae-Yeol Cho

Abstract:

In the design of structural concrete for impact loading, design or model codes often employ a dynamic increase factor (DIF) to impose dynamic effect on static response. Dynamic increase factors that are obtained from laboratory material test results and that are commonly given as a function of strain rate only are quite different from each other depending on the design concept of design codes like ACI 349M-06, fib Model Code 2010 and ACI 370R-14. Because the dynamic increase factors currently adopted in the codes are too simple and limited to consider a variety of strength of materials, their application in practical design is questionable. In this study, the dynamic increase factors used in the three codes were validated through the finite element analysis of reinforced concrete slab elements which were tested and reported by other researcher. The test was intended to simulate a wall element of the containment building in nuclear power plants that is assumed to be subject to impact scenario that the Pentagon experienced on September 11, 2001. The finite element analysis was performed using the ABAQAUS 6.10 and the plasticity models were employed for the concrete, reinforcement. The dynamic increase factors given in the three codes were applied to the stress-strain curves of the materials. To estimate the dynamic increase factors, strain rate was adopted as a parameter. Comparison of the test and analysis was done with regard to perforation depth, maximum deflection, and surface crack area of the slab. Consequently, it was found that DIF has so great an effect on the behavior of the reinforced concrete structures that selection of DIF should be very careful. The result implies that DIF should be provided in design codes in more delicate format considering various influence factors.

Keywords: impact, strain rate, DIF, slab elements

Procedia PDF Downloads 284
1516 Approximation of Geodesics on Meshes with Implementation in Rhinoceros Software

Authors: Marian Sagat, Mariana Remesikova

Abstract:

In civil engineering, there is a problem how to industrially produce tensile membrane structures that are non-developable surfaces. Nondevelopable surfaces can only be developed with a certain error and we want to minimize this error. To that goal, the non-developable surfaces are cut into plates along to the geodesic curves. We propose a numerical algorithm for finding approximations of open geodesics on meshes and surfaces based on geodesic curvature flow. For practical reasons, it is important to automatize the choice of the time step. We propose a method for automatic setting of the time step based on the diagonal dominance criterion for the matrix of the linear system obtained by discretization of our partial differential equation model. Practical experiments show reliability of this method. Because approximation of the model is made by numerical method based on classic derivatives, it is necessary to solve obstacles which occur for meshes with sharp corners. We solve this problem for big family of meshes with sharp corners via special rotations which can be seen as partial unfolding of the mesh. In practical applications, it is required that the approximation of geodesic has its vertices only on the edges of the mesh. This problem is solved by a specially designed pointing tracking algorithm. We also partially solve the problem of finding geodesics on meshes with holes. We implemented the whole algorithm in Rhinoceros (commercial 3D computer graphics and computer-aided design software ). It is done by using C# language as C# assembly library for Grasshopper, which is plugin in Rhinoceros.

Keywords: geodesic, geodesic curvature flow, mesh, Rhinoceros software

Procedia PDF Downloads 134
1515 Photocatalytic Degradation of Nd₂O₃@SiO₂ Core-Shell Nanocomposites Under UV Irradiation Against Methylene Blue and Rhodamine B Dyes

Authors: S. Divya, M. Jose

Abstract:

Over the past years, industrial dyes have emerged as a significant threat to aquatic life, extensively detected in drinking water and groundwater, thus contributing to water pollution due to their improper and excessive use. To address this issue, the utilization of core-shell structures has been prioritized as it demonstrates remarkable efficiency in utilizing light energy for catalytic reactions and exhibiting excellent photocatalytic activity despite the availability of various photocatalysts. This work focuses on the photocatalytic degradation of Nd₂O₃@SiO₂ CSNs under UV light irradiation against MB and RhB dyes. Different characterization techniques, including XRD, FTIR, and TEM analyses, were employed to reveal the material's structure, functional groups, and morphological features. VSM and XPS analyses confirmed the soft, paramagnetic nature and chemical states with respective atomic percentages, respectively. Optical band gaps, determined using the Tauc plot model, indicated 4.24 eV and 4.13 eV for Nd₂O₃ NPs and Nd₂O₃@SiO₂ CSNs, respectively. The reduced bandgap energy of Nd₂O₃@SiO₂ CSNs enhances light absorption in the UV range, potentially leading to improved photocatalytic efficiency. The Nd₂O₃@SiO₂ CSNs exhibited greater degradation efficiency, reaching 95% and 96% against MB and RhB dyes, while Nd₂O₃ NPs showed 90% and 92%, respectively. The enhanced efficiency of Nd₂O₃@SiO₂ CSNs can be attributed to the larger specific surface area provided by the SiO₂ shell, as confirmed by surface area analysis using the BET surface area analyzer through N₂ adsorption-desorption.

Keywords: core shell nanocomposites, rare earth oxides, photocatalysis, advanced oxidation process

Procedia PDF Downloads 47
1514 A Sociolinguistic Study of the Outcomes of Arabic-French Contact in the Algerian Dialect Tlemcen Speech Community as a Case Study

Authors: R. Rahmoun-Mrabet

Abstract:

It is acknowledged that our style of speaking changes according to a wide range of variables such as gender, setting, the age of both the addresser and the addressee, the conversation topic, and the aim of the interaction. These differences in style are noticeable in monolingual and multilingual speech communities. Yet, they are more observable in speech communities where two or more codes coexist. The linguistic situation in Algeria reflects a state of bilingualism because of the coexistence of Arabic and French. Nevertheless, like all Arab countries, it is characterized by diglossia i.e. the concomitance of Modern Standard Arabic (MSA) and Algerian Arabic (AA), the former standing for the ‘high variety’ and the latter for the ‘low variety’. The two varieties are derived from the same source but are used to fulfil distinct functions that is, MSA is used in the domains of religion, literature, education and formal settings. AA, on the other hand, is used in informal settings, in everyday speech. French has strongly affected the Algerian language and culture because of the historical background of Algeria, thus, what can easily be noticed in Algeria is that everyday speech is characterized by code-switching from dialectal Arabic and French or by the use of borrowings. Tamazight is also very present in many regions of Algeria and is the mother tongue of many Algerians. Yet, it is not used in the west of Algeria, where the study has been conducted. The present work, which was directed in the speech community of Tlemcen-Algeria, aims at depicting some of the outcomes of the contact of Arabic with French such as code-switching, borrowing and interference. The question that has been asked is whether Algerians are aware of their use of borrowings or not. Three steps are followed in this research; the first one is to depict the sociolinguistic situation in Algeria and to describe the linguistic characteristics of the dialect of Tlemcen, which are specific to this city. The second one is concerned with data collection. Data have been collected from 57 informants who were given questionnaires and who have then been classified according to their age, gender and level of education. Information has also been collected through observation, and note taking. The third step is devoted to analysis. The results obtained reveal that most Algerians are aware of their use of borrowings. The present work clarifies how words are borrowed from French, and then adapted to Arabic. It also illustrates the way in which singular words inflect into plural. The results expose the main characteristics of borrowing as opposed to code-switching. The study also clarifies how interference occurs at the level of nouns, verbs and adjectives.

Keywords: bilingualism, borrowing, code-switching, interference, language contact

Procedia PDF Downloads 261
1513 Preparation and Flame-Retardant Properties of Epoxy Resins Containing Organophosphorus Compounds

Authors: Tachita Vlad-Bubulac, Ionela-Daniela Carja, Diana Serbezeanu, Corneliu Hamciuc, Vicente Javier Forrat Perez

Abstract:

The present work describes the preparation of new organophosphorus compounds with high content of phosphorus followed by the incorporation of these compounds into epoxy resin systems in order to investigate the phosphorus effect in terms of thermal stability, flame-retardant and mechanical properties of modified epoxy resins. Thus, two new organophosphorus compounds have been synthesized and fully characterized. 6-Oxido-6H-dibenz[c,e][1,2]oxaphosphorinyl-phenylcarbinol has been prepared by the addition reaction of P–H group of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to carbonyl group of benzaldehyde. By treating the phenylcarbinol derivative with POCl3 a new phosphorus compound was obtained, having a content of 12.227% P. The organophosphorus compounds have been purified by recrystallization while their chemical structures have been confirmed by melting point measurements, FTIR and HNMR spectroscopies. In the next step various flame-retardant epoxy resins with different content of phosphorus have been prepared starting from a commercial epoxy resin and using dicyandiamide (DICY) as a latent curing agent in the presence of an accelerator. Differential scanning calorimetry (DSC) has been applied to investigate the behavior and kinetics of curing process of thermosetting systems. The results showed that the best curing characteristic and glass transition temperature are obtained at a ratio of epoxy resin: DICY: accelerator equal to 94:5:1. The thermal stability of the phosphorus-containing epoxy resins was investigated by thermogravimetric analysis in nitrogen and air, DSC, SEM and LOI test measurements.

Keywords: epoxy resins, flame retardant properties, phosphorus-containing compounds, thermal stability

Procedia PDF Downloads 298
1512 Estimating the Relationship between Education and Political Polarization over Immigration across Europe

Authors: Ben Tappin, Ryan McKay

Abstract:

The political left and right appear to disagree not only over questions of value but, also, over questions of fact—over what is true “out there” in society and the world. Alarmingly, a large body of survey data collected during the past decade suggests that this disagreement tends to be greatest among the most educated and most cognitively sophisticated opposing partisans. In other words, the data show that these individuals display the widest political polarization in their reported factual beliefs. Explanations of this polarization pattern draw heavily on cultural and political factors; yet, the large majority of the evidence originates from one cultural and political context—the United States, a country with a rather unique cultural and political history. One consequence is that widening political polarization conditional on education and cognitive sophistication may be due to idiosyncratic cultural, political or historical factors endogenous to US society—rather than a more general, international phenomenon. We examined widening political polarization conditional on education across Europe, over a topic that is culturally and politically contested; immigration. To do so, we analyzed data from the European Social Survey, a premier survey of countries in and around the European area conducted biennially since 2002. Our main results are threefold. First, we see widening political polarization conditional on education over beliefs about the economic impact of immigration. The foremost countries showing this pattern are the most influential in Europe: Germany and France. However, we also see heterogeneity across countries, with some—such as Belgium—showing no evidence of such polarization. Second, we find that widening political polarization conditional on education is a product of sorting. That is, highly educated partisans exhibit stronger within-group consensus in their beliefs about immigration—the data do not support the view that the more educated partisans are more polarized simply because the less educated fail to adopt a position on the question. Third, and finally, we find some evidence that shocks to the political climate of countries in the European area—for example, the “refugee crisis” of summer 2015—were associated with a subsequent increase in political polarization over immigration conditional on education. The largest increase was observed in Germany, which was at the centre of the so-called refugee crisis in 2015. These results reveal numerous insights: they show that widening political polarization conditional on education is not restricted to the US or native English-speaking culture; that such polarization emerges in the domain of immigration; that it is a product of within-group consensus among the more educated; and, finally, that exogenous shocks to the political climate may be associated with subsequent increases in political polarization conditional on education.

Keywords: beliefs, Europe, immigration, political polarization

Procedia PDF Downloads 135