Search results for: political behavior

Authors: E. E. Tereshatov, M. Yu. Boltoeva, V. Mazan, M. F. Volia, C. M. Folden III

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Room temperature ionic liquids (RTILs) are a class of liquid organic salts with melting points below 20 °C that are considered to be environmentally friendly ‘designers’ solvents. Pure hydrophobic ILs are known to extract metallic species from aqueous solutions. The closest analogues of ionic liquids are deep eutectic solvents (DESs), which are a eutectic mixture of at least two compounds with a melting point lower than that of each individual component. DESs are acknowledged to be attractive for organic synthesis and metal processing. Thus, these non-volatile and less toxic compounds are of interest for critical metal extraction. The US Department of Energy and the European Commission consider indium as a key metal. Its chemical homologue, thallium, is also an important material for some applications and environmental safety. The aim of this work is to systematically investigate In and Tl extraction from aqueous solutions into pure fluorinated ILs and hydrophobic DESs. The dependence of the Tl extraction efficiency on the structure and composition of the ionic liquid ions, metal oxidation state, and initial metal and aqueous acid concentrations have been studied. The extraction efficiency of the TlXz3–z anionic species (where X = Cl– and/or Br–) is greater for ionic liquids with more hydrophobic cations. Unexpectedly high distribution ratios (> 103) of Tl(III) were determined even by applying a pure ionic liquid as receiving phase. An improved mathematical model based on ion exchange and ion pair formation mechanisms has been developed to describe the co-extraction of two different anionic species, and the relative contributions of each mechanism have been determined. The first evidence of indium extraction into new quaternary ammonium- and menthol-based hydrophobic DESs from hydrochloric and oxalic acid solutions with distribution ratios up to 103 will be provided. Data obtained allow us to interpret the mechanism of thallium and indium extraction into ILs and DESs media. The understanding of Tl and In chemical behavior in these new media is imperative for the further improvement of separation and purification of these elements.

Keywords: deep eutectic solvents, indium, ionic liquids, thallium

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Authors: Zahid Ali Ghazi

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Supercapacitors (SCs) have emerged as auspicious energy storage devices because of their fast charge-discharge characteristics and high power densities. In the current study, a simple approach is used to coat activated carbon (AC) with a thin layer of nickel (Ni) by an electroless deposition process to enhance the electrochemical performance of the SC. The synergistic combination of large surface area and high electrical conductivity of the AC, as well as the pseudocapacitive behavior of the metallic Ni, has shown great potential to overcome the limitations of traditional SC materials. First, the materials were characterized using X-ray diffraction (XRD) for crystallography, scanning electron microscopy (SEM) for surface morphology and energy dispersion X-ray (EDX) for elemental analysis. The electrochemical performance of the nickel-coated activated carbon (Ni-AC) is systematically evaluated through various techniques, including galvanostatic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The GCD results revealed that Ni/AC has a higher specific capacitance (1559 F/g) than bare AC (222 F/g) at 1 A/g current density in a 2 M KOH electrolyte. Even at a higher current density of 20 A/g, the Ni/AC showed a high capacitance of 944 F/g as compared to 77 F/g by AC. The specific capacitance (1318 F/g) calculated from CV measurements for Ni-AC at 10mV/sec was in close agreement with GCD data. Furthermore, the bare AC exhibited a low energy of 15 Wh/kg at a power density of 356 W/kg whereas, an energy density of 111 Wh/kg at a power density of 360 W/kg was achieved by Ni/AC-850 electrode and demonstrated a long life cycle with 94% capacitance retention over 50000 charge/discharge cycles at 10 A/g. In addition, the EIS study disclosed that the Rs and Rct values of Ni/AC electrodes were much lower than those of bare AC. The superior performance of Ni/AC is mainly attributed to the presence of excessive redox active sites, large electroactive surface area and corrosive resistance properties of Ni. We believe that this study will provide new insights into the controlled coating of ACs and other porous materials with metals for developing high-performance SCs and other energy storage devices.

Keywords: supercapacitor, cyclic voltammetry, coating, energy density, activated carbon

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Authors: S. Vaibhav Kant Sahu, Surabhi Bipin Seth

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Human well-being has multiple constituents including the basic material for a good life, freedom and choice, health, good social relations, and security. Poverty is also multidimensional and has been defined as the pronounced deprivation of well-being. Dhurwa tribe of Bastar (India) have symbiotic relation with nature, it provisions ecosystem service such as food, fuel and fiber; regulating services such as climate regulation and non-material benefits such as spiritual or aesthetic benefits and they are managing their forest from ages. The demand for ecosystem services is now so great that trade-off among services become rule. Aim of study to explore evidences for linkages between ecosystem services and well-being of indigenous community, how much it helps them in poverty reduction and interaction between them. Objective of study was to find drivers of change and evidence concerning link between ecosystem, human development and sustainability, evidence in decision making does it opt for multi sectoral objectives. Which means human well-being as the central focus for assessment, while recognizing that biodiversity and ecosystems also have intrinsic value. Ecosystem changes that may have little impact on human well-being over days or weeks may have pronounced impacts over years or decades; so assessments needed to be conducted at spatial and temporal scales under social, political, economic scales to have high-resolution data. Researcher used framework developed by Millennium ecosystem assessment; since human action now directly or unknowingly virtually alter ecosystem. Researcher used ethnography study to get primary qualitative data, secondary data collected from panchayat office. The responses were transcribed and translated into English, as interview held in Hindi and local indigenous language. Focus group discussion were held with group of 10 women at Tiriya village. Researcher concluded with well-being is not just gap between ecosystem service supply but also increases vulnerability. Decision can have consequences external to the decision framework these consequences are called externalities because they are not part of the decision-making calculus.

Keywords: Bastar, Dhurwa tribe, ecosystem services, millennium ecosystem assessment, sustainability

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Authors: Akhil Teja Kambhampati, Mark A. Hoffman

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In the realm of infectious disease research, airborne viral transmission stands as a paramount concern due to its pivotal role in propagating pathogens within densely populated regions. However, amidst this landscape, the phenomenon of hygroscopic growth within respiratory bioaerosols remains relatively underexplored. Unlike pure water aerosols, the unique composition of respiratory bioaerosols leads to varied evaporation rates and hygroscopic growth patterns, influenced by factors such as ambient humidity, temperature, and airflow. This study addresses this gap by focusing on the behaviors of single respiratory bioaerosol utilizing salinity to induce saliva-like hygroscopic behavior. By employing mass, momentum, and energy equations, the study unveils the intricate interplay between evaporation and hygroscopic growth over time. The numerical model enables temporal analysis of bioaerosol characteristics, including size, temperature, and trajectory. The analysis reveals that due to evaporation, there is a reduction in initial size, which shortens the lifetime and distance traveled. However, when hygroscopic growth begins to influence the bioaerosol size, the rate of size reduction slows significantly. The interplay between evaporation and hygroscopic growth results in bioaerosol size within the inhalation range of humans and prolongs the traveling distance. Findings procured from the analysis are crucial for understanding the spread of infectious diseases, especially in high-risk environments such as healthcare facilities and public transportation systems. By elucidating the nuanced behaviors of respiratory bioaerosols, this study seeks to inform the development of more effective preventative strategies against pathogens propagation in the air, thereby contributing to public health efforts on a global scale.

Keywords: airborne viral transmission, high-risk environments, hygroscopic growth, evaporation, numerical modeling, pathogen propagation, preventative strategies, public health, respiratory bioaerosols

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Authors: Søren Birkvad

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This paper traces the development of sexual cinematic freedom in the wake of an epoch-making event in Danish cultural history. As the first in the world, the Danes abolished all censorship for adults in 1969, making the tiny nation of Denmark the world’s largest exporter of pornography for several years. Drawing on the insights of social and cultural history and the focus point of the National Cinema direction of Cinema Studies, this study focuses on Danish film pornography in the 1960s and 1970s in its own right (e.g., its peculiar mix of sex, popular comedy and certain ‘feminist’ agendas). More importantly, however, it covers a broader pattern, namely the culturally deep-rooted tradition of freedom of speech and sexual liberalism in Denmark. Thus, the key concept of frisind (“free mind”) in Danish cultural history took on an increasingly partisan application in the 1960s and 1970s. It became a designation for all-is-permitted hippie excess but was also embraced by dissenting movements on the left, such as feminism, which questioned whether a free mind necessarily meant free love. In all of this, Danish cinema from the 1960s and 1970s offers a remarkable source of historical insight, simultaneously reminding us of a number of acute issues of contemporary society. These issues include gendered ideas of sexuality and freedom then and now and the equivalent clash of cultures between a liberal commercial industry and the accelerating political demands of the “sexual revolution.” Finally, these issues include certain tensions between, on the one hand, a purely materialistic idea of sexual freedom – incarnated by anything from pornography to many of the taboo-breaking youth films and avant-garde films in the wake of the 1968-rebellion – and, on the other hand, growing opposition to this anti-spiritual perception of human sexuality (represented by for instance the ‘closet conservatism’ of Danish art film star Lars von Trier of nowadays). All in all, this presentation offers a reflection on ideas of sexuality and gender rooted in a unique historical moment in cinematic history.

Keywords: Danish film history, cultural history, film pornography, history of sexuality, national cinema, sexual liberalism

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Authors: S. Y. Park, S. M. Lee, S. H. Lee, K. M. Lim

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In this research analyzed the effects that phase formation reaction change in the grey cast iron makes on characteristics of microstructures, liquidity, and mechanical properties through cooling curve when adding rare earth elements (R.E). This research was analyzed with comparison between the case of not adding the rare earth elements (R.E) into the grey cast iron with the standard composition (as 3.3%C-2.1%Si-0.7%Mn-0.1%S) and the case of adding 0.3% rare earth elements (R.E). The thermal analysis parameters have been drawn through eutectic temperature theoretically calculated, recalescence temperature, and undercooling temperature measured from start of eutectic reaction to end of solidification in the cooling curve obtained by thermal analysis to analyze formation behavior of graphite, and the effects by addition of rare earth elements on this have been reviewed. When adding rare earth elements (R.E), the cause of liquidity slowdown was analyzed trough the solidification starting temperature and change of solidification ending temperature. The strength and hardness have been measured to evaluate the mechanical properties, and the sound tensile strength has been evaluated through quality coefficient after measuring relative hardness and normality degree of tensile strength by calculating theoretical tensile strength and theoretical hardness. The change of Pearlite Inter-lamellar Spacing of matrix microstructure and eutectic cell count of macrostructure was measured to analyze the effects of the rare earth elements on the sound tensile strength. The change of eutectic cell count has been clarified through activation of the eutectic reaction, and the cause of pearlite inter-lamellar spacing clarified through eutectoid reaction temperature.

Keywords: cooling curve, element, grey cast iron, thermal analysis, rare earth element

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Authors: Maryam Nzari

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Today, with the advancement of Internet technology, one of the tools used by humans is a tool that allows them to do what they need easily. Online platforms in different forms and by providing different services make it possible for users to communicate with each other and users with platforms. Audience communication with mass media is not the same as in the past. Today the conditions are different; With online platforms that provide the latest news minute by minute, he has access to all the content and can choose more quickly and easily. According to professionals Galloway, Apple, Amazon, Facebook and Google companies create a wide range. They are among the products and services that are connected with the daily life of billions of people all over the planet. Over time, platforms gain high economic value and in this way gain power that will influence the social, cultural, economic and political aspects of people’s lives. As a result of the effects of the process of platformization on all areas of individual and collective life, we now live in a platform society, which communicates It is close to “platform politics”. Nowadays, with social media platforms, users can interact with many people and people can share their data on various topics with others in this space. In this research, what will be investigated is the role of these online platforms in economic growth and the introduction of local culture areas in tourist areas. Tourism in a region is linked with various factors; One of the important factors that attract tourists to a region is its culture, and on the other hand, this culture can also affect economic growth. Without a proper understanding of the culture of these tourist areas, it is not possible to plan properly for the growth of the tourism industry and the subsequent increase in economic growth. The interaction of local people and tourists will have social and cultural effects on each other and will give them the opportunity to get to know each other. Therefore, the purpose of this research is to examine issues such as the role that online platforms play in cultural interaction in tourist areas and to understand that online platforms are only seeking to show the good aspects of a region and then generate enough extra income or that platforms can They play a role beyond what we imagine and introduce the culture of a region in a proper way so that we don’t see disagreements in the tourism planning of that region. in this article It has been tried by using library and field methods Answer the questions.

Keywords: online platforms, economic growth, culture Indigenous, tourism

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Authors: Anuruddhi Edirisinghe, Anusha Edirisinghe, Maithree Wicramasinghe, Sagarika Kannangara, Annista Wijayanayake

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SGBV which refer to acts of inflicting physical, mental or sexual harm or sufferings that deprive a person’s liberty based on one’s gender or sexuality is known to occur in various forms. Ragging in educational institutions can often be one such form of SGBV. Ragging related SGBV is a growing problem despite various legal, policy and programme initiatives introduced over the years. While the punishment of perpetrators through the criminal justice system is expected to bring a deterrent effect, other strategies such as awareness-raising, attitudinal changes, and the empowerment of students to say no to ragging and SGBV will lead to enlightened attitudes about the practice in universities. Thus, effective regular prevention programmes are the need of the hour. The objectives of the paper are to engage with the case of a female fresher subjected to verbal abuse, physical assault and sexual harassment due to events which started as a result of wearing a trouser to the university during the ragging season. The case came to the limelight since a complaint was made to the police and 10 students were arrested under the anti-ragging act. This led to dividend opinions among the student population and a backlash from the student union. Simultaneously, this resulted in the society demanding the stricter implementation of laws and the punishment of perpetrators. The university authority appointed a task force comprising of academics, non-academics, parents, community leaders, stakeholders and students to draw up an action plan to respond to the immediate situation as well as future prevention. The paper will also discuss the implementation of task force plan. The paper is based on interviews with those involved with the issue and the experiences of the task force members and is expected to provide an in-depth understanding of the intricacies and complications associated with dealing with a contentious problem such as ragging. Given the political and ethical issues involved with insider research as well as the sensationalism of the topic, maximum care will be taken to safeguard the interests of those concerned.

Keywords: fresher, sexual and gender based violence (SGBV), sexual harassment, ragging

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Authors: Rhea Khosla, Victoria Tzortziou-Brown

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Introduction: Adolescent SRH has been neglected since the start of the millennium. Adolescents comprise 16% of the global population, with the largest proportion living in Asia (650 million). By late adolescence, individuals in these regions are likely to become sexually active, and thus they must understand their SRH rights. Many lack knowledge of SRH, using unreliable sources for such information. Sex education is necessary to standardize and inform sexual knowledge, which empowers adolescents to make informed SRH decisions. School is an appropriate environment for this, however, SRH education requires effective policy to enforce. Nonetheless, this issue remains of low political priority in Asia and Africa. Current literature on sex education policy in schools in these regions is scarce and tends to have broad aims. Thus, a scoping review was necessary. Methods: Literature searches were conducted in February 2023 using six databases, including grey literature databases (PubMed, Scopus, Embase, Web of Science, Google Scholar, Global Index Medicus), returning a total of 1537 unique articles. After screening titles, abstracts and full text, 17 articles remained. References of included articles were additionally searched, producing a further 7 articles, which then underwent thematic analysis Results: Most countries in Africa and Asia did not have studies on this topic. Studies derived data from interviews with key stakeholders and quantitative methods quantified questionnaire responses. Barriers were: policy/curriculum issues, societal opinions, teaching discomfort, and lack of educator training. Limitations were insufficient timing, inconsistent implementation, insufficient hours dedicated to teaching, education received late into schooling, and discrepancies between teachers, schools, and students about whether policies were being implemented. Discussion: Based on the existing limited evidence, a cultural shift to reduce stigma seems necessary, alongside teacher and student involvement in policy formulation with effective implementation monitoring and educator training.

Keywords: adolescent, Africa, Asia, education, sexual and reproductive health, policy

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Authors: Scott R. Butler

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Ontario, Canada’s largest province, is in the midst of an interesting experiment in mandated asset management planning for local governments. At the beginning of 2021, Ontario’s 444 municipalities were responsible for the management of 302,864 lane kilometers of roads that have a replacement cost of $97.545 billion CDN. Roadways are by far the most complex, expensive, and extensive assets that a municipality is responsible for overseeing. Since adopting Ontario Regulation 588/47: Asset Management Planning for Municipal Infrastructure in 2017, the provincial government has established prescriptions for local road authorities regarding asset category and levels of service being provided. This provincial regulation further stipulates that asset data such as extent, condition, and life cycle costing are to be captured in manner compliant with qualitative descriptions and technical metrics. The Ontario Good Roads Association undertook an exercise to aggregate the road-related data contained within the 444 asset management plans that municipalities have filed with the provincial government. This analysis concluded that collectively Ontario municipal roadways have a $34.7 billion CDN in deferred maintenance. The ill-state of repair of Ontario municipal roads has lasting implications for province’s economic competitiveness and has garnered considerable political attention. Municipal efforts to address the maintenance backlog are stymied by the extremely limited fiscal parameters municipalities must operate within in Ontario. Further exacerbating the program are provincially designed programs that are ineffective, administratively burdensome, and not necessarily aligned with local priorities or strategies. This paper addresses how municipal asset management plans – and more specifically, the data contained in these plans – can be used to design innovative policy frameworks, flexible funding programs, and new levels of service that respond to these funding challenges, as well as emerging issues such as local economic development and climate change. To fully unlock the potential that Ontario Regulation 588/17 has imposed will require a resolute commitment to data standardization and horizontal collaboration between municipalities within regions.

Keywords: transportation, municipal asset management, subnational policy design, subnational funding program design

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Authors: Santiago Silva de Andrade

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In recent decades, Marx's ecological theory of the value-form and the theory of metabolic rift have represented fundamental methodological innovations for social scientists interested in environmental transformations and their relationships with the development of the capital system. However, among Latin American environmental historians, such theoretical and methodological instruments have been used infrequently and very cautiously. This investigation aims to demonstrate how the concepts of metabolic rift and ecological value-form are important for understanding the environmental, economic and social transformations in the Amazon region between the second half of the 19th century and the end of the 20th century. Such transformations manifested themselves mainly in two dimensions: the first concerns the link between the manufacture of tropical substances for export and scientific developments in the fields of botany, chemistry and agriculture. This link was constituted as a set of social, intellectual and economic relations that condition each other, configuring an asymmetrical field of exchanges and connections between the demands of the industrialized world - personified in scientists, naturalists, businesspeople and bureaucrats - and the agencies of local social actors, such as indigenous people, riverside dwellers and quilombolas; the second dimension concerns the imperative link between the historical development of the capitalist world-system and the restructuring of the natural world, its landscapes, biomes and social relations, notably in peripheral colonial areas. The environmental effects of capitalist globalization were not only seen in the degradation of exploited environments, although this has been, until today, its most immediate and noticeable aspect. There was also, in territories subject to the logic of market accumulation, the reformulation of patterns of authority and institutional architectures, such as property systems, political jurisdictions, rights and social contracts, as a result of the expansion of commodity frontiers between the 16th and 21st centuries. . This entire set of transformations produced impacts on the ecological landscape of the Amazon. This demonstrates the need to investigate the histories of local configurations of power, spatial and ecological - with their institutions and social actors - and their role in structuring the capitalist world-system , under the lens of the ecological theory of value-form and metabolic rift.

Keywords: amazon, ecology, form-value, metabolic rift

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Authors: Dammar Bahadur Adhikari

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Community forestry in Nepal has got disproportionately high level of support from government and other actors in forestry sector. Even though master plan for forestry sector (1989) has highlighted community and private forestry as one component, the government policies and other intervention deliberately left out private forestry in its structure and programs. The study aimed at providing the pathway for formulating appropriate policies to address need of different kind of forest management regimes in Rautahat district, Nepal. The key areas the research focused were assessment of current status of private forestry, community forest users' understanding on private forestry; criteria for choosing species of private forestry and factors affecting establishment of private forestry in the area. Qualitative and quantitative data were collected employing questionnaire survey, rapid forest assessment and key informant interview. The study found out that forest policies are imposed due to intense pressure of exogenous forces than due to endogenous demand. Most of the local people opine that their traditional knowledge and skills are not sufficient for private forestry and hence need training on the matter. Likewise, local use, market value and rotation dictate the choice of species for plantation in private forests. Currently district forest office is the only government institution working in the area of private forestry all other governmental and non-governmental organizations have condoned. private forestry. Similarly, only permanent settlers in the area are found to establish private forests other forest users such as migrants and forest encroachers follow opportunistic behavior to meet their forest product need from community and national forests. In this regard, the study recommends taking appropriate step to support other forest management system including private forestry provide community forestry the benefits of competition as suggested by Darwin in 18th century, one and half century back and to help alleviate poverty by channelizing benefits to household level.

Keywords: community forest, forest management, poverty, private forest, users’ group

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Authors: Abdul-Nasser El-Kassar, Walid Elgammal, Hisham Jawhar

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This paper studies the determinants of the dividends payout ratio. The factors affecting the dividends payout ratio are to be identified. The study focuses only on the cement and construction industry within the MENA region in an attempt to isolate any incoherent behavior. The factors under consideration are: sales growth, ROE, ROA, ROS, debt to equity ratio, firm size, and free cash flow. Data were collected from official stock exchange markets in addition to annual reports. The study considered all firms that paid dividend in each of the three consecutive years starting from 2010 till 2012. Out of the 123 listed firms that work in cement and construction industry in MENA region, only 19 paid dividends in the three consecutive years 2010-12. Our sample consists of the 19 firms (57 observations) which are selected according to purposive sampling. Moreover, the study uses the homogeneous subcategory within the purposive sampling since only similar firms in the construction industry had been examined. The outcome of the study provides a vital insight into the determinants of dividends payout ratio of companies in MENA region. The results showed that the dividend payout ratio has a strong and positive relationship with return on assets and strong but negative relationship with return on equity. On the other hand, the results detected weak relationships between dividend payout ratio and sale growth, debt to equity ratio, firm size, and free cash flow. The study suggests that board of directors tend to compensate shareholders and minimize the agency cost by distributing a high portion of profits in form of dividends whenever return on equity decreases. Also, when the performance of the firm improves, and hence return on assets increases, boards of directors are more generous in distributing profits.

Keywords: dividends payout ratio, profitability firm size, free cashflow, debt to equity ratio

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Authors: María Jesús Luengo-Valderrey, Mónica Moso-Díez

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In the knowledge-based economy, innovation is considered essential in order to achieve survival and growth in organizations. On the other hand, knowledge management is currently understood as one of the keys to innovation process. Both factors are generally admitted as generators of competitive advantage in organizations. Specifically, activities on R&D&I and those that generate internal knowledge have a positive influence in innovation results. This paper examines this effect and if it is similar or not is what we aimed to quantify in this paper. We focus on the impact that proportion of knowledge workers, the R&D&I investment, the amounts destined for ICTs and training for innovation have on the variation of tangible and intangibles returns for the sector of high and medium technology in Spain. To do this, we have performed an empirical analysis on the results of questionnaires about innovation in enterprises in Spain, collected by the National Statistics Institute. First, using clusters methodology, the behavior of these enterprises regarding knowledge management is identified. Then, using SEM methodology, we performed, for each cluster, the study about cause-effect relationships among constructs defined through variables, setting its type and quantification. The cluster analysis results in four groups in which cluster number 1 and 3 presents the best performance in innovation with differentiating nuances among them, while clusters 2 and 4 obtained divergent results to a similar innovative effort. However, the results of SEM analysis for each cluster show that, in all cases, knowledge workers are those that affect innovation performance most, regardless of the level of investment, and that there is a strong correlation between knowledge workers and investment in knowledge generation. The main findings reached is that Spanish high and medium technology companies improve their innovation performance investing in internal knowledge generation measures, specially, in terms of R&D activities, and underinvest in external ones. This, and the strong correlation between knowledge workers and the set of activities that promote the knowledge generation, should be taken into account by managers of companies, when making decisions about their investments for innovation, since they are key for improving their opportunities in the global market.

Keywords: high and medium technology sector, innovation, knowledge management, Spanish companies

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Authors: Debarshi Bhattacharya

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In 2015, historic Land Boundary Agreement (LBA) executed between India and Bangladesh finally settled almost seven decades long overdue critical enclave problems of the two neighbouring countries. Enclaves within India and Bangladesh were the awful outcome of the partition of India in 1947. As a dire consequence, the populace within these enclaves enormously suffered from getting basic rights and opportunities and governmental support services till long 67 years after India’s independence and partition. As per LBA, 2015, 51 Bangladeshi (BD) enclaves inside Indian territory and 111 Indian enclaves inside Bangladesh territory were actually transferred to each other. But, by virtue of LBA, 1974 executed earlier between the two countries, one BD enclave situated inside India, namely Dohogram-Angarpota (D-A) twin enclave, had not yet been exchanged by means of LBA, 2015 and it still remains as an integral part, may not be contiguous, of Bangladesh completely surrounded by Indian territory. A study was undertaken through an extensive field survey to assess the impact of the existence of D-A BD enclave inside Indian territory from India’s perspective. Field survey was conducted for the purpose in the form of an interview, group discussion, questionnaire survey, personal interaction etc. to gather information from the Indian people residing adjacent to D-A enclave and Tin Bigha Corridor (TBC), people of D-A enclave, officials of Border Security Forces of India and Bangladesh, public representatives, representatives of political organizations etc. The issue of the existence of D-A BD enclave inside Indian territory seriously brought apprehension of future problems to the people of Kuchlibari Region of Mekhligunj Block, India, on its contiguity with Indian mainland due to 24-hour open access for the BD people through TBC. The anxiety of the local Indian people regarding threats to the national security of India as well as to the law and order issues of the locality due to the open border of D-A BD enclave in the region. On the other hand, it was observed that 24 hours opening of TBC brought significant positive changes to the people of D-A BD enclave in terms of their socio-economic condition and security status.

Keywords: enclave, exchange of enclaves, land boundary agreement, Dohogram-Angarpota (D-A) Bangladeshi (BD) enclave, Tin Bigha Corridor

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Authors: Jie Ren, Siyao Guo

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Laden with phosphates at a low pH value, sewage wastewater aggressive environments constitute a great threat to concrete-based pipes which is made of alkaline cementitious materials such as ordinary Portland cement (OPC). As a promising alternative for OPC-based binders, alkali-activated slag/fly ash (AASF) cementitious binders are generally believed to gain similar or better properties compared to OPC-based counterparts, especially durability. However, there is limited research on the performance of AASF binders in phosphoric acid solution. Moreover, the behavior of AASF binders composited with epoxy resin/TiO₂ when exposed to acidic media has been rarely explored. In this study, the performance of AASF paste with the precursor slag:fly ash (50:50 in mass ratio) enhanced with epoxy resin/TiO₂ composite in phosphoric acid solution (pH = 3.0-4.0) was investigated. The exposure towards acid attack lasted for 90 days. The same AASF mixture without resin/TiO₂ composite was used as a reference. The compressive strength and porous-related properties prior to acidic immersion were tested. The mass variations and degradation depth of the two mixtures of binders were also monitored which is based on phenolphthalein-videomicroscope method. The results show that the binder with epoxy resin/TiO₂ addition gained a higher compressive strength and lower water absorption than the reference. In addition, it also displayed a higher resistance towards acid attack indicated by a less mass loss and less degradation depth compared to the control sample. This improvement can be attributed to a dense microstructure evidenced by the higher compressive strength and related porous structures. It can be concluded that the microstructure can be improved by adding epoxy resin/TiO₂ composite in order to enhance the resistance of AASF binder towards acid attacks.

Keywords: alkali-activated paste, epoxy resin/TiO₂, composites, mechanical properties, phosphoric acid

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Authors: Jin-Siang Shaw, Patricia Moya Caceres, Sheng-Xiang Xu

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This paper aims to integrate the particle swarm optimization (PSO) method with the adaptive fuzzy sliding mode controller (AFSMC) to achieve vibration attenuation in a piezoelectric actuator subject to base excitation. The piezoelectric actuator is a complicated system made of ferroelectric materials and its performance can be affected by nonlinear hysteresis loop and unknown system parameters and external disturbances. In this study, an adaptive fuzzy sliding mode controller is proposed for the vibration control of the system, because the fuzzy sliding mode controller is designed to tackle the unknown parameters and external disturbance of the system, and the adaptive algorithm is aimed for fine-tuning this controller for error converging purpose. Particle swarm optimization method is used in order to find the optimal controller parameters for the piezoelectric actuator. PSO starts with a population of random possible solutions, called particles. The particles move through the search space with dynamically adjusted speed and direction that change according to their historical behavior, allowing the values of the particles to quickly converge towards the best solutions for the proposed problem. In this paper, an initial set of controller parameters is applied to the piezoelectric actuator which is subject to resonant base excitation with large amplitude vibration. The resulting vibration suppression is about 50%. Then PSO is applied to search for an optimal controller in the neighborhood of this initial controller. The performance of the optimal fuzzy sliding mode controller found by PSO indeed improves up to 97.8% vibration attenuation. Finally, adaptive version of fuzzy sliding mode controller is adopted for further improving vibration suppression. Simulation result verifies the performance of the adaptive controller with 99.98% vibration reduction. Namely the vibration of the piezoelectric actuator subject to resonant base excitation can be completely annihilated using this PSO based adaptive fuzzy sliding mode controller.

Keywords: adaptive fuzzy sliding mode controller, particle swarm optimization, piezoelectric actuator, vibration suppression

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Authors: Sonam Chorol, Sharvan Kumar, Pritam Mukhopadhyay

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In biology, supramolecular systems require the use of chemical fuels to stay in sustained nonequilibrium steady states termed dissipative self-assembly in contrast to synthetic self-assembly. Biomimicking these natural dynamic systems, some studies have demonstrated artificial self-assembly under nonequilibrium utilizing various forms of energies (fuel) such as chemical, redox, and pH. Naphthalene diimides (NDIs) are well-known organic molecules in supramolecular architectures with high electron affinity and have applications in controlled electron transfer (ET) reactions, etc. Herein, we report the endergonic ET from tetraphenylborate to highly electron-deficient phosphonium NDI²+ dication to generate NDI•+ radical. The formation of radicals was confirmed by UV-Vis-NIR absorption spectroscopy. Electron-donor and electron-acceptor energy levels were calculated from experimental electrochemistry and theoretical DFT analysis. The HOMO of the electron donor locates below the LUMO of the electro-acceptor. This indicates that electron transfer is endergonic (ΔE°ET = negative). The endergonic ET from NaBPh₄ to NDI²+ dication was achieved thermodynamically by the formation of coupled biphenyl product confirmed by GC-MS analysis. NDI molecule bearing octyl phosphonium at the core and H-bond forming imide moieties at the axial position forms a gel. The rheological properties of purified radical ion NDI⦁+ gels were evaluated. The atomic force microscopy studies reveal the formation of large branching-type networks with a maximum height of 70-80 nm. The endergonic ET from NaBPh₄ to NDI²+ dication was used to design the assembly and disassembly redox reaction cycle using reducing (NaBPh₄) and oxidizing agents (Br₂) as chemical fuels. A part of NaBPh₄ is used to drive assembly, while a fraction of the NaBPh₄ is dissipated by forming a useful product. The system goes back to the disassembled NDI²+ dication state with the addition of Br₂. We think bioinspired dissipative self-assembly is the best approach to developing future lifelike materials with autonomous behavior.

Keywords: Ionic-gel, redox-cycle, self-assembly, useful product

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Authors: Jing-Jing Wang, Yang Gao, Heather H. M. Kwok, Wendy Y. J. Huang

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Objectives: Intellectual disability (ID) ranks among the top 20 most costly disorders. A child with ID creates a wide set of challenges to the individual, family, and society, and overweight and obesity aggravate those challenges. People with ID have the right to attain optimal health like the rest of the population. They should be given priority to eliminate existing health inequities. Childhood obesity epidemic and associated factors among children, in general, has been well documented, while knowledge about overweight and obesity in children with ID is scarce. Methods: A cross-sectional study was conducted among 524 Chinese children with ID (males: 68.9%, mean age: 12.2 years) in Hong Kong in 2015. Children’s height and weight were measured at school. Parents, in the presence of their children, completed a self-administered questionnaire at home about the children’s physical activity (PA), eating habits, and sleep duration in a typical week as well as parenting practices regarding children’s eating and PA, and their socio-demographic characteristics. Multivariate logistic regression estimated the potential risk factors for children being overweight. Results: The prevalence of overweight and obesity in children with ID was 31.3%, which was higher than their general counterparts (18.7%-19.9%). Multivariate analyses revealed that the risk factors of overweight and obese in children with ID included: comorbidity with autism, the maternal side being overweight or obese, parenting practices with less pressure to eat more, children having shorter sleep duration, longer periods of sedentary behavior, and higher intake frequencies of sweetened food, fried food, and meats, fish, and eggs. Children born in other places, having snacks more frequently, and having irregular meals were also more likely to be overweight or obese, with marginal significance. Conclusions: Children with ID are more vulnerable to being overweight or obese than their typically developing counterparts. Identified risk factors in this study highlight a multifaceted approach to the involvement of parents as well as the modification of some children’s questionable behaviors to help them achieve a healthy weight.

Keywords: prevalence, risk factors, obesity, children with disability

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Authors: Bharath Kenchappa, Kunigal Shivakumar

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Lightweight, low thermal conductivity and high temperature resistant materials or the system with moderate mechanical properties and capable of taking high heating rates are needed in both commercial and military applications. A single material with these attributes is very difficult to find and one needs to come with innovative ideas to make such material system using what is available. To bring down the cost of the system, one has to be conscious about the cost of basic materials. Such a material system can be called as the thermal barrier system. This paper focuses on developing, testing and characterization of material system for thermal barrier applications. The material developed is porous, low density, low thermal conductivity of 0.1062 W/m C and glass transition temperature about 310 C. Also, the thermal properties of the developed material was measured in both longitudinal and thickness direction to highlight the fact that the material shows isotropic behavior. The material is called modified Eco-Core which uses only less than 9% weight of high-char resin in the composite. The filler (reinforcing material) is a component of fly ash called Cenosphere, they are hollow micro-bubbles made of ceramic materials. Special mixing-technique is used to surface coat the fillers with a thin layer of resin to develop a point-to-point contact of particles. One could use commercial ceramic micro-bubbles instead of Cenospheres, but it is expensive. The bulk density of Cenospheres is about 0.35 g/cc and we could accomplish the composite density of about 0.4 g/cc. One percent filler weight of 3mm length standard drywall grade fibers was used to bring the added toughness. Both thermal and mechanical characterization was performed and properties are documented. For higher temperature applications (up to 1,000 C), a hybrid system was developed using an aerogel mat. Properties of combined material was characterized and documented. Thermal tests were conducted on both the bare modified Eco-Core and hybrid materials to assess the suitability of the material to a thermal barrier application. The hybrid material system was found to meet the requirement of the application.

Keywords: aerogel, fly ash, porous material, thermal barrier

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Authors: Francesca Nicolosi, Teresa Cosola

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Climate changes in Mediterranean areas, such as the increase of average seasonal temperatures, the urban heat island phenomenon, the intensification of solar radiation and the extreme weather threats, cause disruption events, so that climate adaptation has become a pressing issue. Due to the strategic role that the built heritage holds in terms of environmental impact and energy waste and its potentiality, it is necessary to assess the vulnerability and the adaptive capacity of the existing building to climate change, in order to define different mitigation scenarios. The aim of this research work is to define an optimized and integrated methodology for the assessment of resilience levels and adaptation scenarios for existing buildings in Mediterranean urban areas. Moreover, the study of resilience indicators allows us to define building environmental and energy performance in order to identify the design and technological solutions for the improvement of the building and its urban area potentialities. The methodology identifies step-by-step different phases, starting from the detailed study of characteristic elements of urban system: climatic, natural, human, typological and functional components are analyzed in their critical factors and their potential. Through the individuation of the main perturbing factors and the vulnerability degree of the system to the risks linked to climate change, it is possible to define mitigation and adaptation scenarios. They can be different, according to the typological, functional and constructive features of the analyzed system, divided into categories of intervention, and characterized by different analysis levels (from the single building to the urban area). The use of software simulations allows obtaining information on the overall behavior of the building and the urban system, to generate predictive models in the medium and long-term environmental and energy retrofit and to make a comparative study of the mitigation scenarios identified. The studied methodology is validated on a case study.

Keywords: climate impact mitigation, energy efficiency, existing building heritage, resilience

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Authors: Oscar E. Cariceo, Claudia V. Casal

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Machine learning offers a set of techniques to promote social work interventions and can lead to support decisions of practitioners in order to predict new behaviors based on data produced by the organizations, services agencies, users, clients or individuals. Machine learning techniques include a set of generalizable algorithms that are data-driven, which means that rules and solutions are derived by examining data, based on the patterns that are present within any data set. In other words, the goal of machine learning is teaching computers through 'examples', by training data to test specifics hypothesis and predict what would be a certain outcome, based on a current scenario and improve that experience. Machine learning can be classified into two general categories depending on the nature of the problem that this technique needs to tackle. First, supervised learning involves a dataset that is already known in terms of their output. Supervising learning problems are categorized, into regression problems, which involve a prediction from quantitative variables, using a continuous function; and classification problems, which seek predict results from discrete qualitative variables. For social work research, machine learning generates predictions as a key element to improving social interventions on complex social issues by providing better inference from data and establishing more precise estimated effects, for example in services that seek to improve their outcomes. This paper exposes the results of a classification algorithm to predict cyberbullying among adolescents. Data were retrieved from the National Polyvictimization Survey conducted by the government of Chile in 2017. A logistic regression model was created to predict if an adolescent would experience cyberbullying based on the interaction and behavior of gender, age, grade, type of school, and self-esteem sentiments. The model can predict with an accuracy of 59.8% if an adolescent will suffer cyberbullying. These results can help to promote programs to avoid cyberbullying at schools and improve evidence based practice.

Keywords: cyberbullying, evidence based practice, machine learning, social work research

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Authors: M. S. Nandana, K. Udaya Bhat, C. M. Manjunatha

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In this study aluminum alloy 7010 was subjected to three different ageing treatments i.e., peak ageing (T6), over-ageing (T7451) and retrogression and re ageing (RRA) to study the influence of precipitate microstructure on the fatigue crack growth rate behavior. The microstructural modification was studied by using transmission electron microscope (TEM) to examine the change in the size and morphology of precipitates in the matrix and on the grain boundaries. The standard compact tension (CT) specimens were fabricated and tested under constant amplitude fatigue crack growth tests to evaluate the influence of heat treatment on the fatigue crack growth rate properties. The tests were performed in a computer-controlled servo-hydraulic test machine applying a load ratio, R = 0.1 at a loading frequency of 10 Hz as per ASTM E647. The fatigue crack growth was measured by adopting compliance technique using a CMOD gauge attached to the CT specimen. The average size of the matrix precipitates were found to be of 16-20 nm in T7451, 5-6 nm in RRA and 2-3 nm in T6 conditions respectively. The grain boundary precipitate which was continuous in T6, was disintegrated in RRA and T7451 condition. The PFZ width was lower in RRA compared to T7451 condition. The crack growth rate was higher in T7451 and lowest in RRA treated alloy. The RRA treated alloy also exhibits an increase in threshold stress intensity factor range (∆Kₜₕ). The ∆Kₜₕ measured was 11.1, 10.3 and 5.7 MPam¹/² in RRA, T6 and T7451 alloys respectively. The fatigue crack growth rate in RRA treated alloy was nearly 2-3 times lower than that in T6 and was one order lower than that observed in T7451 condition. The surface roughness of RRA treated alloy was more pronounced when compared to the other conditions. The reduction in fatigue crack growth rate in RRA alloy was majorly due to the increase in roughness and partially due to increase in spacing between the matrix precipitates. The reduction in crack growth rate and increase in threshold stress intensity range is expected to benefit the damage tolerant capability of aircraft structural components under service loads.

Keywords: damage tolerance, fatigue, heat treatment, PFZ, RRA

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Authors: Calogero Lo Destro

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Numerous nations around the world are facing exceptional challenges in employing measures to stop the spread of COVID-19. Following the recommendations of the World Health Organization, a series of preventive measures have been adopted. However, individuals must comply with these rules and recommendations in order to make these measures effective. While COVID-19 was climaxing, it seemed of crucial importance to analyze which psychosocial factors contribute to the acceptance of such preventive behavior, thus favoring the management of COVID-19 worldwide health crisis. In particular, the identification of aspects related to obstacles and facilitation of adherence to social distancing has been considered crucial in the containment of the virus spread. Since the virus was firstly detected in China, Asian people could be considered a relevant outgroup targeted for exclusion. We also hypothesized social distance could be influenced by characteristics of the target, such as smiling or coughing. 260 participants participated in this research on a voluntary basis. They filled a survey designed to explore a series of COVID-19 measures (such as exposure to virus and fear of infection). We also assessed participants state and trait anxiety. The dependent variable was social distance, based on a measure of seating distance designed ad hoc for the present work. Our hypothesis that participants could report greater distance in response to Asian people was not confirmed. On the other hand, significantly lower distance in response to smiling compared to coughing targets was reported. Adopting a regression analysis model, we found that participants' social distance, in response to both coughing and smiling targets, was predicted by fear of infection and by the perception COVID-19 could become a pandemic. Social distance in response to the coughing target was also significantly and positively predicted by age and state anxiety. In summary, the present work has sought to identify a set of psychological variables, which may still be predictive of social distancing.

Keywords: COVID-19, social distancing, health, preventive behaviors, risk of infection

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Authors: Ahmad Umar, Ahmed A. Ibrahim, Mohsen A. Alhamami

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This study introduces a facile synthesis method for synthesizing reduced graphene oxide (rGO) nanosheets with surface decoration of polyaniline (PANI). The resultant rGO@PANI nanocomposite (NC) exhibit substantial potential as advanced electrode materials for high-performance supercapacitors. The strategic integration of PANI onto the rGO surface serves dual purposes, effectively mitigating the agglomeration of rGO films and augmenting their utility in supercapacitor applications. The PANI coating manifests a highly porous and nanosized morphology, fostering increased surface area and optimized mass transport by reducing diffusion kinetics. The nanosized structure of PANI contributes to the maximization of active sites, thereby bolstering the efficacy of the nanocomposites for diverse applications. The inherent conductive nature of the rGO surface significantly expedites electron transport, thereby amplifying the overall electrochemical performance of the nanocomposites. To systematically evaluate the influence of PANI concentration on the electrode performance, varying concentrations of PANI were incorporated. Notably, an elevated PANI concentration was found to enhance the response owing to the unique morphology of PANI. Remarkably, the 5% rGO@PANI NC emerged as the most promising candidate, demonstrating exceptional response characteristics with a specific capacitance of 314.2 F/g at a current density of 1 A/g. Furthermore, this catalyst exhibits outstanding long-term stability, retaining approximately 92% of its capacitance even after enduring 4000 cycles. This research underscores the significance of the synergistic integration of rGO and PANI in the design of high-performance supercapacitors. The elucidation of the underlying mechanisms governing the improved electrochemical properties contributes to the fundamental understanding of nanocomposite behavior, thereby paving the way for the rational design of next-generation energy storage materials.

Keywords: reduced graphene oxide, polyaniline, nanocomposites, supercapacitors, energy storage

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Authors: Chia-Ying Lin

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This paper explains how to enhance doctor-patient communication and nurse-patient communication through multiple intelligence signing methods and user-centered. It is hoped that through the implementation of the "electronic consent", the problems faced by the paper consent can be solved: storage methods, resource utilization, convenience, correctness of information, integrated management, statistical analysis and other related issues. Make better use and allocation of resources to provide better medical quality. First, invite the ｍedical records department to assist in the inventory of paper consent in the hospital: organising, classifying, merging, coding, and setting. Second, plan the electronic consent configuration file: set the form number, consent form group, fields and templates, and the corresponding doctor's order code. Next, Summarize four types of rapid methods of electronic consent: according to the doctor's order, according to the medical behavior, according to the schedule, and manually generate the consent form. Finally, system promotion and adjustment: form an "electronic consent promotion team" to improve, follow five major processes: planning, development, testing, release, and feedback, and invite clinical units to raise the difficulties faced in the promotion, and make improvements to the problems. The electronic signature rate of the whole hospital will increase from 4% in January 2022 to 79% in November 2022. Use the saved resources more effectively, including: reduce paper usage (reduce carbon footprint), reduce the cost of ink cartridges, re-plan and use the space for paper medical records, and save human resources to provide better services. Through the introduction of information technology and technology, the main spirit of "lean management" is implemented. Transforming and reengineering the process to eliminate unnecessary waste is also the highest purpose of this project.

Keywords: smart signature, electronic consent, electronic medical records, user-centered, doctor-patient communication, nurse-patient communication

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Authors: Unsain Dianne, Roussel Audrey, Goude Gwenaëlle, Magniez Pierre, Storå Jan

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This paper aims to investigate the changes in husbandry practices and meat consumption during the transition from the Medieval Climate Anomaly to the Little Ice Age in the South of France. More precisely, we will investigate breeding strategies, animal size and health status, carcass exploitation strategies, and the impact of socioeconomic status on human-environment interactions. For that purpose, we will analyze faunal remains from ten sites equally distributed between the two periods. Those include consumers from different socio-economic backgrounds (peasants, city dwellers, soldiers, lords, and the Popes). The research will employ different methods used in zooarchaeology: comparative anatomy, biometry, pathologies analyses, traceology, and utility indices, as well as experimental archaeology, to reconstruct and understand the changes in animal breeding and consumption practices. Their analysis will allow the determination of modifications in the animal production chain, with the composition of the flocks (species, size), their management (age, sex, health status), culinary practices (strategies for the exploitation of carcasses, cooking, tastes) or the importance of trade (butchers, sales of processed animal products). The focus will also be on the social extraction of consumers. The aim will be to determine whether climate change has had a greater impact on the most modest groups (such as peasants), whether the consequences have been global and have also affected the highest levels of society, or whether the social and economic factors have been sufficient to balance out the climatic hazards, leading to no significant changes. This study will contribute to our understanding of the impact of climate change on breeding and consumption strategies in medieval society from a historical and social point of view. It combines various research methods to provide a comprehensive analysis of the changes in human-animal interactions during different climatic periods.

Keywords: archaeology, animal economy, cooking, husbandry practices, climate change, France

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Authors: Zahid Ullah, Atlas Khan

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This research endeavors to explore the regularity properties associated with a specific class of equations, namely extremely degenerate elliptic equations. These equations hold significance in understanding complex physical systems like porous media flow, with applications spanning various branches of mathematics. The focus is on unraveling and analyzing regularity results to gain insights into the smoothness of solutions for these highly degenerate equations. Elliptic equations, fundamental in expressing and understanding diverse physical phenomena through partial differential equations (PDEs), are particularly adept at modeling steady-state and equilibrium behaviors. However, within the realm of elliptic equations, the subset of extremely degenerate cases presents a level of complexity that challenges traditional analytical methods, necessitating a deeper exploration of mathematical theory. While elliptic equations are celebrated for their versatility in capturing smooth and continuous behaviors across different disciplines, the introduction of degeneracy adds a layer of intricacy. Extremely degenerate elliptic equations are characterized by coefficients approaching singular behavior, posing non-trivial challenges in establishing classical solutions. Still, the exploration of extremely degenerate cases remains uncharted territory, requiring a profound understanding of mathematical structures and their implications. The motivation behind this research lies in addressing gaps in the current understanding of regularity properties within solutions to extremely degenerate elliptic equations. The study of extreme degeneracy is prompted by its prevalence in real-world applications, where physical phenomena often exhibit characteristics defying conventional mathematical modeling. Whether examining porous media flow or highly anisotropic materials, comprehending the regularity of solutions becomes crucial. Through this research, the aim is to contribute not only to the theoretical foundations of mathematics but also to the practical applicability of mathematical models in diverse scientific fields.

Keywords: elliptic equations, extremely degenerate, regularity results, partial differential equations, mathematical modeling, porous media flow

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Authors: Amatulraheem Al-Abassi, K. Khanafer, Ibrahim Deiab

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The coronary artery stent is a promising technology that can treat various coronary diseases. Materials used for manufacturing medical stents should have high biocompatible properties. Stent alloys, in particular, are remarkably promising good clinical outcomes, however, there is threaten of restenosis (reoccurring of artery narrowing due to fatty plaque), stent recoiling, or in long-term the occurrence of stent fracture. However, stents that are made of Nickel-titanium (Nitinol) can bare extensive plastic deformation and resist restenosis. This shape memory alloy has outstanding mechanical properties. Nitinol is a unique shape memory alloy as it has unique mechanical properties such as; biocompatibility, super-elasticity, and recovery to original shape under certain loads. Stent failure may cause complications in vascular diseases and possibly blockage of blood flow. Thus, studying the behaviors of the stent under different medical conditions will help the doctors and cardiologists to predict when it is necessary to change the stent in order to prevent any severe morbidity outcomes. To the best of our knowledge, there are limited published papers that analyze the stent behavior with regards to the contact surfaces of plaque layer and blood vessel. Thus, stent material properties will be discussed in this investigation to highlight the mechanical and clinical differences between various stents. This research analyzes the performance of Nitinol stent in well-known stent design to determine its bearing with stress and its dislocation in blood vessels, in comparison to stents made of different biocompatible materials. In addition, a study of its performance will be represented in the system. Finite Element Analysis is the core of this study. Thus, a physical representative model will be discussed to show the distribution of stress and strain along the interaction surface between the stent and the artery. The reaction of vascular tissue to the stent will be evaluated to predict the possibility of restenosis within the treated area.

Keywords: shape memory alloy, stent, coronary artery, finite element analysis

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Authors: Tamseela Habib, Muhammad Amjad, Muhammad Edokali, Masome Moeni, Olivia Pickup, Ali Hassanpour

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Nanofluid-assisted steam generation is rapidly attracting attention amongst the scientific community since it can be applied in a wide range of industrial processes. Because of its high absorption rate of solar energy, nanoparticle-based solar steam generation could be a major contributor to many applications, including water desalination, sterilization and power generation. Lithium bromide-based iron oxide nanofluids have been previously studied in steam generation, which showed promising results. However, the efficiency of the system could be improved if a more heat-conductive nanofluid system could be utilised. In the current paper, we report on an experimental investigation of the photothermal conversion properties of functionalised Copper oxide (CuO) nanoparticles used in Lithium Bromide salt solutions. CuO binary nanofluid was prepared by chemical functionalization with polyethyleneimine (PEI). Long-term stability evaluation of prepared binary nanofluid was done by a high-speed centrifuge analyser which showed a 0.06 Instability index suggesting low agglomeration and sedimentation tendencies. This stability is also supported by the measurements from dynamic light scattering (DLS), transmission electron microscope (TEM), and ultraviolet-visible (UV-Vis) spectrophotometer. The fluid rheology is also characterised, which suggests the system exhibits a Newtonian fluid behavior. The photothermal conversion efficiency of different concentrations of CuO was experimentally investigated under a solar simulator. Experimental results reveal that the binary nanofluid in this study can remarkably increase the solar energy trapping efficiency and evaporation rate as compared to conventional fluids due to localized solar energy harvesting by the surface of the nanofluid. It was found that 0.1wt% CuO NP is the optimum nanofluid concentration for enhanced sensible and latent heat efficiencies.

Keywords: nanofluids, vapor absorption refrigeration system, steam generation, high salinity

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