Search results for: fluid dynamics principles

Authors: Efri Mardawati, Ronny Purwadi, Made Tri Ari Penia Kresnowati, Tjandra Setiadi

Abstract:

EFB are mainly composed of cellulose (≈ 43%), hemicellulose (≈ 23%) and lignin (≈20%). The palm oil empty fruit bunches (EFB) is the lignosellulosic waste from crude palm oil industries mainly compose of (≈ 43%), hemicellulose (≈ 23%) and lignin (≈20%). Xylan, a polymer made of pentose sugar xylose and the most abundant component of hemicellulose in plant cell wall. Further xylose can be used as a raw material for production of a wide variety of chemicals such as xylitol, which is extensively used in food, pharmaceutical and thin coating applications. Currently, xylose is mostly produced from xylan via chemical hydrolysis processes. However, these processes are normally conducted at a high temperature and pressure, which is costly, and the required downstream processes are relatively complex. As an alternative method, enzymatic hydrolysis of xylan to xylose offers an environmentally friendly biotechnological process, which is performed at ambient temperature and pressure with high specificity and at low cost. This process is catalysed by xylanolytic enzymes that can be produced by some fungal species such as Aspergillus niger, Penicillium crysogenum, Tricoderma reseei, etc. Fungal that will be used to produce crude xylanase enzyme in this study is T. Viride ITB CC L.67. It is the purposes of this research to study the influence of pretreatment of EFB for the enzymatic hydrolysis process, optimation of temperature and pH of the hydrolysis process, the influence of substrate and enzyme concentration to the enzymatic hydrolysis process, the dynamics of hydrolysis process and followingly to study the kinetics of this process. Xylose as the product of enzymatic hydrolysis process analyzed by HPLC. The results show that the thermal pretreatment of EFB enhance the enzymatic hydrolysis process. The enzymatic hydrolysis can be well approached by the Michaelis Menten kinetic model, and kinetic parameters are obtained from experimental data.

Keywords: oil palm empty fruit bunches (EFB), xylose, enzymatic hydrolysis, kinetic modelling

Procedia PDF Downloads 389

Authors: Justin Nwabanne, Sam Omenyi, Jeremiah Chukwuneke

Abstract:

This work presents structural nonlinear static analysis of a horizontal taut cable using Finite Element Analysis (FEA) method. The FEA was performed analytically to determine the tensions at each nodal point and subsequently, performed based on finite element displacement method computationally using the FEA software, ANSYS 14.0 to determine their behaviour under the influence of aerodynamic forces imposed on the cable. The convergence procedure is adapted into the method to prevent excessive displacements through the computations. The work compared the two FEA cases by examining the effectiveness of the analytical model in describing the response with few degrees of freedom and the ability of the nonlinear finite element procedure adopted to capture the complex features of cable dynamics with reference to the aerodynamic external influence. Results obtained from this work explain that the analytic FEM results without aerodynamic influence show a parabolic response with an optimum deflection at nodal points 12 and 13 with the cable weight at nodes 12 and 13 having the value -1.002936N while for the cable tension shows an optimum deflection value for nodes 12 and 13 at -189396.97kg/km. The maximum displacement for the cable system was obtained from ANSYS 14.0 as 4483.83 mm for X, Y and Z components of displacements at node number 2 while the maximum displacement obtained is 4218.75mm for all the directional components. The dynamic behaviour of a taut cable investigated has application in a typical power transmission line. Aerodynamic influences on the cables were considered using FEA approach by employing ANSYS 14.0 showed a complex modal behaviour as expected.

Keywords: aerodynamics, cable tension and weight, finite element analysis, nodal, non-linear model, optimum deflection, suspended cable, transmission line

Procedia PDF Downloads 279

Authors: Tanvir A. Uddin, Blake Goud

Abstract:

Emerging trends in FinTech-enabled alternative finance, which includes channels and instruments emerging outside the traditional financial system, heralds unprecedented opportunities to improve financial intermediation and increase access to finance. With widespread criticism of the mainstream Islamic banking and finance sector as either mimicking the conventional system, failing to achieve inclusive growth or both, industry stakeholders are turning to technology to show that finance can be done differently. This paper will outline the critical elements for successful deployment of technology to maximize benefit and minimize potential for harm from introduction of Islamic FinTech and propose recommendations for Islamic financial institutions, FinTech companies, regulators and other stakeholders who are integrating or who are considering introducing FinTech solutions. The paper will present an overview of literature, present relevant case studies and summarize the lessons from interviews conducted with Islamic FinTech founders from around the world. With growing central bank concerns about leveraged loans and ballooning private credit markets globally (estimated at $1.4 trillion), current and future Islamic FinTech operators are at risk of contributing to the problems they aim to solve by operating in a 'shadow banking' system. The paper will show that by systematising a robust theory of change linked to positive outcomes, utilising objective impact frameworks (e.g., the Impact Measurement Project) and instilling a risk management culture that is proactive about potential social harm (e.g., irresponsible lending), FinTech can enable the Islamic finance industry to support positive social impact and minimize harm in support of the maqasid. The adoption of FinTech within the Islamic finance context is still at a nascent stage and the recommendations we provide based on the limited experience to date will help address some of the major cross-cutting issues related to FinTech. Further research will be needed to elucidate in more detail issues relating to individual sectors and countries within the broader global Islamic finance industry.

Keywords: alternative finance, FinTech, Islamic finance, maqasid, theory of change

Procedia PDF Downloads 154

Authors: Zahra Hamidi

Abstract:

Promoting cycling, as an affordable environmentally friendly mode of transport to replace private car use has been central to sustainable transport policies. Cycling is faster than walking and combined with public transport has the potential to extend the opportunities that people can access. In other words, cycling, besides direct positive health impacts, can improve people mobility and ultimately their quality of life. Transport literature well supports the close relationship between mobility, quality of life, and, well being. At the same time inequity in the distribution of access and mobility has been associated with the key aspects of injustice and social exclusion. The pattern of social exclusion and inequality in access are also often related to population characteristics such as age, gender, income, health, and ethnic background. Therefore, while investing in transport infrastructure it is important to consider the equity of provided access for different population groups. This paper proposes a method to evaluate the equity of cycling in a city from Rawls egalitarian perspective. Since this perspective is concerned with the difference between individuals and social groups, this method combines accessibility measures and Theil index of inequality that allows capturing the inequalities ‘within’ and ‘between’ groups. The paper specifically focuses on two population characteristics as gender and ethnic background. Following Rawls equity principles, this paper measures accessibility by bikes to a selection of urban activities that can be linked to the concept of the social primary goods. Moreover, as growing number of cities around the world have launched bike-sharing systems (BSS) this paper incorporates both private and public bikes networks in the estimation of accessibility levels. Additionally, the typology of bike lanes (separated from or shared with roads), the presence of a bike sharing system in the network, as well as bike facilities (e.g. parking racks) have been included in the developed accessibility measures. Application of this proposed method to a real case study, the city of Malmö, Sweden, shows its effectiveness and efficiency. Although the accessibility levels were estimated only based on gender and ethnic background characteristics of the population, the author suggests that the analysis can be applied to other contexts and further developed using other properties, such as age, income, or health.

Keywords: accessibility, cycling, equity, gender

Procedia PDF Downloads 403

Authors: Melissa Dickinson

Abstract:

In the context of intense global competitiveness and urban transformations, today’s cities are faced with enormous challenges. There is increasing pressure among cities and regions to respond promptly and efficiently to fierce market progressions, to offer a competitive advantage, higher flexibility, and to be pro-active in creating future markets. Consequently, competition among cities and regions within the dynamics of a worldwide spatial economic system is growing fiercer, amplifying the importance of intangible capital in shaping the competitive and dynamic economic performance of organisations and firms. Accordingly, this study addresses how intangible capital influences urban economic development within an urban environment. Despite substantial research on the economic, and strategic determinants of urban economic development this multidimensional phenomenon remains to be one of the greatest challenges for economic geographers. The research provides a unique contribution, exploring intangible capital through the lenses of entrepreneurial capital and social-network capital. Drawing on business surveys and in-depth interviews with key stakeholders in the case of the three UK Core Cities Birmingham, Bristol and Cardiff. This paper critically considers how entrepreneurial capital and social-network capital is a crucial source of competitiveness and urban economic development. This paper deals with questions concerning the complexity of operationalizing ‘network capital’ in different urban settings and the challenges that reside in characterising its effects. The paper will highlight the role of institutions in facilitating urban economic development. Particular emphasis will be placed on exploring the roles formal and informal institutions have in delivering, supporting and nurturing entrepreneurial capital and social-network capital, to facilitate urban economic development. Discussions will then consider how institutions moderate and contribute to the economic development of urban areas, to provide implications in terms of future policy formulation in the context of large and medium sized cities.

Keywords: urban economic development, network capital, entrepreneurialism, institutions

Procedia PDF Downloads 276

Authors: Sercan Altundemir, Pinar Eribol, A. Kerem Uguz

Abstract:

Microfluidics systems allow many-large scale laboratory applications to be miniaturized on a single device in order to reduce cost and advance fluid control. Moreover, such systems enable to generate and control droplets which have a significant role on improved analysis for many chemical and biological applications. For example, they can be employed as the model for cells in microfluidic systems. In this work, the interfacial instability of two immiscible Newtonian liquids flowing in a microchannel is investigated. When two immiscible liquids are in laminar regime, a flat interface is formed between them. If a direct current electric field is applied, the interface may deform, i.e. may become unstable and it may be ruptured and form micro-droplets. First, the effect of thickness ratio, total flow rate, viscosity ratio of the silicone oil and ethylene glycol liquid couple on the critical voltage at which the interface starts to destabilize is investigated. Then the droplet sizes are measured under the effect of these parameters at various voltages. Moreover, the effect of total flow rate on the time elapsed for the interface to be ruptured to form droplets by hitting the wall of the channel is analyzed. It is observed that an increase in the viscosity or the thickness ratio of the silicone oil to the ethylene glycol has a stabilizing effect, i.e. a higher voltage is needed while the total flow rate has no effect on it. However, it is observed that an increase in the total flow rate results in shortening of the elapsed time for the interface to hit the wall. Moreover, the droplet size decreases down to 0.1 μL with an increase in the applied voltage, the viscosity ratio or the total flow rate or a decrease in the thickness ratio. In addition to these observations, two empirical models for determining the critical electric number, i.e., the dimensionless voltage and the droplet size and another model which is a combination of both models, for determining the droplet size at the critical voltage are established.

Keywords: droplet formation, electrohydrodynamics, microfluidics, two-phase flow

Procedia PDF Downloads 176

Authors: Yang Shen, Yongpan Cheng, Jinliang Xu

Abstract:

The effective blade cooling is of great significance for improving the performance of turbine. The mist cooling emerges as the promising way compared with the transitional single-phase cooling. In the mist cooling, the injected droplet will evaporate rapidly, and cool down the blade surface due to the absorbed latent heat, hence the lifetime for evaporating droplet becomes critical for design of cooling passages for the blade. So far there have been extensive studies on the droplet evaporation, but usually the isothermal model is applied for most of the studies. Actually the surface cooling effect can affect the droplet evaporation greatly, it can prolong the droplet evaporation lifetime significantly. In our study, a new theoretical model for sessile droplet evaporation with surface cooling effect is built up in toroidal coordinate. Three evaporation modes are analyzed during the evaporation lifetime, include “Constant Contact Radius”(CCR) mode、“Constant Contact Angle”(CCA) mode and “stick-slip”(SS) mode. The dimensionless number E0 is introduced to indicate the strength of the evaporative cooling, it is defined based on the thermal properties of the liquid and the atmosphere. Our model can predict accurately the lifetime of evaporation by validating with available experimental data. Then the temporal variation of droplet volume, contact angle and contact radius are presented under CCR, CCA and SS mode, the following conclusions are obtained. 1) The larger the dimensionless number E0, the longer the lifetime of three evaporation cases is; 2) The droplet volume over time still follows “2/3 power law” in the CCA mode, as in the isothermal model without the cooling effect; 3) In the “SS” mode, the large transition contact angle can reduce the evaporation time in CCR mode, and increase the time in CCA mode, the overall lifetime will be increased; 4) The correction factor for predicting instantaneous volume of the droplet is derived to predict the droplet life time accurately. These findings may be of great significance to explore the dynamics and heat transfer of sessile droplet evaporation.

Keywords: blade cooling, droplet evaporation, lifetime, theoretical analysis

Procedia PDF Downloads 142

Authors: Berfu Guley Goren, Ayse Lale Berkoz

Abstract:

The aim of the study is to analyze the concept of universal design and accessibility to make the city which allows equality and independence for individuals. In the content of the study, literature researches and observations of samples in Istanbul, Turkey are analyzed. As a result proposals are going to be developed to create the cities which are designed for everyone. In globalization process, in cities, population have been increasing dramatically with social and economic activities. Medical developments have been effective in prolonging human life and the disability that comes with aging has also increased in parallel with the disabled population. Nowadays disability is an important phenomenon. Because approximately 1 billion people live with disabilities. The heterogeneous structure formed by the rapid gathering of individuals with different social, economic and physical characteristics in the cities creates great spatial diversity and richness in the cities with different needs brought together. Unlike the cultural and physical wealth in these places and the potential to integrate and diversify the urban people, unfortunately, the designs in practice cause the urban areas to break apart, the urbanities to tear themselves apart, to interfere with their communication and interactions. The social and physical structure of the city is important to feel belonging to the urban society. In most cities when an observation is made, obstructions for people with disabilities can be seen in urban physical structure and design. With these obstructions, people with disabilities cannot live in urban space, and they are desolated in urban life. The city, which offers equal opportunity, the relation between economic development, social justice and built environment must be planned synchronous. Isolation and stigmatization must be abolished by regulations, activities of awareness and universal urban design. Without regard to social, economical and physical features every individual has the same right, which is using the freedom of movement. Supporting freedom of movement of every individual may be ensured by universal design and its principles. So urban spaces are going to be for every individual. For equal opportunity in urban services, urban design must be the focus on every individual including people with disabilities. In built environment practices, democratic suitable spaces should be created. In this respect, urban planners, architects, political decision-makers and other relevant actors should work together and should think very versatile.

Keywords: disability, equality, universal design, urban design

Procedia PDF Downloads 302

Authors: Sadman Durlov, Aditya Ganesh-Ram, Hamidreza Hekmatjou, Md Najmus Salehin, Nora Shayesteh Ameri

Abstract:

In the field of additive manufacturing, tungsten stands out for its exceptional resistance to high temperatures, making it an ideal candidate for use in extreme conditions. However, its inherent brittleness and vulnerability to thermal cracking pose significant challenges to its manufacturability. This study explores the microstructural evolution of tungsten processed through layer-wise rolling in laser powder bed fusion additive manufacturing, utilizing a comprehensive approach that combines advanced simulation techniques with empirical research. We aim to uncover the complex processes of plastic deformation and microstructural transformations, with a particular focus on the dynamics of grain size, boundary evolution, and phase distribution. Our methodology employs a combination of simulation and experimental data, allowing for a detailed comparison that elucidates the key mechanisms influencing microstructural alterations during the rolling process. This approach facilitates a deeper understanding of the material's behavior under additive manufacturing conditions, specifically in terms of deformation and recrystallization. The insights derived from this research not only deepen our theoretical knowledge but also provide actionable strategies for refining manufacturing parameters to improve the tungsten components' mechanical properties and functional performance. By integrating simulation with practical experimentation, this study significantly enhances the field of materials science, offering a robust framework for the development of durable materials suited for challenging operational environments. Our findings pave the way for optimizing additive manufacturing techniques and expanding the use of tungsten across various demanding sectors.

Keywords: additive manufacturing, layer wise rolling, refractory materials, in-situ microstructure modifications

Procedia PDF Downloads 61

Authors: Omer Livvarcin, Mary Kay Park, Michael Miles

Abstract:

The current literature includes a few studies that mention the impact of relations between teams, the business environment, and experiences from previous projects. There is, however, limited research that treats the phenomenon of project atmosphere (PA) as a whole. This is especially true of research identifying parameters and sub-parameters, which allow project management (PM) teams to build a project culture that ultimately imbues project success. This study’s findings identify a number of key project atmosphere parameters and sub-parameters that affect project management success. One key parameter identified in the study is a cluster related to cultural concurrence, including artifacts such as policies and mores, values, perceptions, and assumptions. A second cluster centers on motivational concurrence, including such elements as project goals and team-member expectations, moods, morale, motivation, and organizational support. A third parameter cluster relates to experiential concurrence, with a focus on project and organizational memory, previous internal PM experience, and external environmental PM history and experience). A final cluster of parameters is comprised of those falling in the area of relational concurrence, including inter/intragroup relationships, role conflicts, and trust. International and intercultural project management data was collected and analyzed from the following countries: Canada, China, Nigeria, South Korea and Turkey. The cross-cultural nature of the data set suggests increased confidence that the findings will be generalizable across cultures and thus applicable for future international project management success. The intent of the identification of project atmosphere as a critical project management element is that a clear understanding of the dynamics of its sub-parameters upon projects may significantly improve the odds of success of future international and intercultural projects.

Keywords: project management, project atmosphere, cultural concurrence, motivational concurrence, relational concurrence

Procedia PDF Downloads 318

Authors: Kin On Kwok, Vivian Wei, Benjamin Cowling, Steven Riley, Jonathan Read

Abstract:

Background: The role of social contact behavior measured in different contact constructs in the transmission of respiratory pathogens with acute respiratory illness (ARI) remains unclear. We, therefore, aim to depict the individual pattern of ARI in the community and investigate the association between different contact dimensions and ARI in Hong Kong. Methods: Between June 2013 and September 2013, 620 subjects participated in the last two waves of recruitment of the population based longitudinal phone social contact survey. Some of the subjects in this study are from the same household. They are also provided with the symptom diaries to self-report any acute respiratory illness related symptoms between the two days of phone recruitment. Data from 491 individuals who were not infected on the day of phone recruitment and returned the symptom diaries after the last phone recruitment were used for analysis. Results: After adjusting different follow-up periods among individuals, the overall incidence rate of ARI was 1.77 per 100 person-weeks. Over 75% ARI episodes involve running nose, cough, sore throat, which are followed by headache (55%), malagia (35%) and fever (18%). Using a generalized estimating equation framework accounting for the cluster effect of subjects living in the same household, we showed that both daily number of locations visited with contacts and the number of contacts, explained the ARI incidence rate better than only one single contact construct. Conclusion: Our result suggests that it is the intertwining property of contact quantity (number of contacts) and contact intensity (ratio of subject-to-contact) that governs the infection risk by a collective set of respiratory pathogens. Our results provide empirical evidence that multiple contact constructs should be incorporated in the mathematical transmission models to feature a more realistic dynamics of respiratory disease.

Keywords: acute respiratory illness, longitudinal study, social contact, symptom diaries

Procedia PDF Downloads 261

Authors: Ruthanne Tobin

Abstract:

The shift to a personalized learning (PL) curriculum in Canada represents an innovative approach to teaching and learning that is also evident in various initiatives across the 32-nation OECD. The premise behind PL is that empowering individual learners to have more input into how they access and construct knowledge, and express their understanding of it, will result in more meaningful school experiences and academic success. In this paper presentation, the author reports on a document analysis of the new curriculum in the province of British Columbia. Three theoretical frameworks are used to analyze the new curriculum. Framework 1 focuses on five dominant aspects (FDA) of PL at the classroom level. Framework 2 focuses on conceptualizing and enacting personalized learning (CEPL) within three spheres of influence. Framework 3 focuses on the integration of three types of knowledge (content, technological, and pedagogical). Analysis is ongoing, but preliminary findings suggest that the new curriculum addresses framework 1 quite well, which identifies five areas of personalized learning: 1) assessment for learning; 2) effective teaching and learning; 3) curriculum entitlement (choice); 4) school organization; and 5) “beyond the classroom walls” (learning in the community). Framework 2 appears to be less well developed in the new curriculum. This framework speaks to the dynamics of PL within three spheres of interaction: 1) nested agency, comprised of overarching constraints [and enablers] from policy makers, school administrators and community; 2) relational agency, which refers to a capacity for professionals to develop a network of expertise to serve shared goals; and 3) students’ personalized learning experience, which integrates differentiation with self-regulation strategies. Framework 3 appears to be well executed in the new PL curriculum, as it employs the theoretical model of technological, pedagogical content knowledge (TPACK) in which there are three interdependent bodies of knowledge. Notable within this framework is the emphasis on the pairing of technologies with excellent pedagogies to significantly assist students and teachers. This work will be of high relevance to educators interested in innovative school reform.

Keywords: curriculum reform, K-12 school change, innovations in education, personalized learning

Procedia PDF Downloads 282

Authors: Liwiusz Wojciechowski

Abstract:

Research background: The current knowledge does not give a clear answer to the question of the impact of FDI on productivity. Results of the empirical studies are still inconclusive, no matter how extensive and diverse in terms of research approaches or groups of countries analyzed they are. It should also take into account the possibility that FDI and productivity are linked and that there is a bidirectional relationship between them. This issue is particularly important because on one hand FDI can contribute to changes in productivity in the host country, but on the other hand its level and dynamics may imply that FDI should be undertaken in a given country. As already mentioned, a two-way relationship between the presence of foreign capital and productivity in the host country should be assumed, taking into consideration the endogenous nature of FDI. Purpose of the article: The overall objective of this study is to determine the causality between foreign direct investment and total factor productivity in host county in terms of different relative absorptive capacity across countries. In the classic sense causality among variables is not always obvious and requires for testing, which would facilitate proper specification of FDI models. The aim of this article is to study endogeneity of selected macroeconomic variables commonly being used in FDI models in case of Visegrad countries: main recipients of FDI in CEE. The findings may be helpful in determining the structure of the actual relationship between variables, in appropriate models estimation and in forecasting as well as economic policymaking. Methodology/methods: Panel and time-series data techniques including GMM estimator, VEC models and causality tests were utilized in this study. Findings & Value added: The obtained results allow to confirm the hypothesis states the bi-directional causality between FDI and total factor productivity. Although results differ from among countries and data level of aggregation implications may be useful for policymakers in case of providing foreign capital attracting policy.

Keywords: endogeneity, foreign direct investment, multi-equation models, total factor productivity

Procedia PDF Downloads 198

Authors: Timilehin Martins Oyinloye, Won Byong Yoon

Abstract:

Simulation technology is being adopted in many industries, with research focusing on the development of new ways in which technology becomes embedded within production, services, and society in general. 3D printing (3DP) technology is fast developing in the food industry. However, the limited processability of high-performance material restricts the robustness of the process in some cases. Significantly, the printability of materials becomes the foundation for extrusion-based 3DP, with residual stress being a major challenge in the printing of complex geometry. In many situations, the trial-a-error method is being used to determine the optimum printing condition, which results in time and resource wastage. In this report, the analysis of 3 moisture levels for surimi paste was investigated for an optimum 3DP material and printing conditions by probing its rheology, flow characteristics in the nozzle, and post-deposition process using the finite element method (FEM) model. Rheological tests revealed that surimi pastes with 82% moisture are suitable for 3DP. According to the FEM model, decreasing the nozzle diameter from 1.2 mm to 0.6 mm, increased the die swell from 9.8% to 14.1%. The die swell ratio increased due to an increase in the pressure gradient (1.15107 Pa to 7.80107 Pa) at the nozzle exit. The nozzle diameter influenced the fluid properties, i.e., the shear rate, velocity, and pressure in the flow field, as well as the residual stress and the deformation of the printed sample, according to FEM simulation. The post-printing stability of the model was investigated using the additive layer manufacturing (ALM) model. The ALM simulation revealed that the residual stress and total deformation of the sample were dependent on the nozzle diameter. A small nozzle diameter (0.6 mm) resulted in a greater total deformation (0.023), particularly at the top part of the model, which eventually resulted in the sample collapsing. As the nozzle diameter increased, the accuracy of the model improved until the optimum nozzle size (1.0 mm). Validation with 3D-printed surimi products confirmed that the nozzle diameter was a key parameter affecting the geometry accuracy of 3DP of surimi paste.

Keywords: 3D printing, deformation analysis, die swell, numerical simulation, surimi paste

Procedia PDF Downloads 68

Authors: Tara Panday, Despina Learmonth

Abstract:

Sex work is often constructed as being an interaction between male clients and female sex workers. As a result, street-based male sex workers are continuously overlooked in the South African literature. This qualitative study explored male sex workers’ subjective experiences and constructions of their male clients’ identities and the client-sex worker relationship. This research was conducted from a social-constructionist perspective, which allowed for a deeper understanding of the reasons and context driving the choices and actions of male sex workers. Semi-structured face-to-face interviews were conducted with 10 South African men working as sex workers in Cape Town. Data was analysed through thematic analysis. The findings of the study construct the client-sex worker relationship in terms of a professional relationship, constrained choice, sexual identity and need, as well as companionship for pay, potentially highlighting underlying reasons for supply and demand. The data which emerged around the client-sex worker relationship and the clients’ identities also served to illuminate the power-dynamics in the client-sex worker relationship. This data increases insight into the exploitation and disempowerment experienced by male sex workers through verbal abuse, physical and sexual violence, and unfairly enforced laws and regulations. The findings of this study suggest that, in the context of South Africa, male sex workers' experiences of the client-sex worker relationship cannot be completely understood without considering the intersectionality of the triple stigmatisation of: the criminality of sex work, race, and the lack of economic power, which systematically maintains marginalization. Motivating for the Law Reform Commission to continue to review all emerging research may assist with guiding related policy and thereby, the provision of equal human rights and adequate health and social interventions for all sex workers in South Africa.

Keywords: human rights, prostitution, power relations, sex work

Procedia PDF Downloads 483

Authors: Sule Pallavi, Shah Priyank, Thavkar Amit, Mehta Suyog, Rohira Poonam

Abstract:

Minoxidil is used topically to help hair growth in the treatment of male androgenetic alopecia. The objective of this study is to compare irritation potential of three conventional formulation of minoxidil 5% topical solution of in human patch test. The study was a single centre, double blind, non-randomized controlled study in 56 healthy adult Indian subjects. Occlusive patch test for 24 hours was performed with three formulation of minoxidil 5% topical solution. Products tested included aqueous based minoxidil 5% (AnasureTM 5%, Sun Pharma, India – Brand A), alcohol based minoxidil 5% (Brand B) and aqueous based minoxidil 5% (Brand C). Isotonic saline 0.9% and 1% w/w sodium lauryl sulphate were included as negative control and positive control respectively. Patches were applied and removed after 24hours. The skin reaction was assessed and clinically scored 24 hours after the removal of the patches under constant artificial daylight source using Draize scale (0-4 points scale for erythema/wrinkles/dryness and for oedema). A combined mean score up to 2.0/8.0 indicates a product is “non-irritant” and score between 2.0/8.0 and 4.0/8.0 indicates “mildly irritant” and score above 4.0/8.0 indicates “irritant”. Follow-up was scheduled after one week to confirm recovery for any reaction. The procedure of the patch test followed the principles outlined by Bureau of Indian standards (BIS) (IS 4011:2018; Methods of Test for safety evaluation of Cosmetics-3rd revision). Fifty six subjects with mean age 30.9 years (27 males and 29 females) participated in the study. The combined mean score (± standard deviation) were: 0.13 ± 0.33 (Brand A), 0.39 ± 0.49 (Brand B), 0.22 ± 0.41 (Brand C), 2.91 ± 0.79 (Positive control) and 0.02 ± 0.13 (Negative control). The mean score of Brand A (Sun Pharma product) was significantly lower than Brand B (p=0.001) and was comparable with Brand C (p=0.21). The combined mean erythema score (± standard deviation) were: 0.09 ± 0.29 (Brand A), 0.27 ± 0.5 (Brand B), 0.18 ± 0.39 (Brand C), 2.02 ± 0.49 (Positive control) and 0.0 ± 0.0 (Negative control). The mean erythema score of Brand A was significantly lower than Brand B (p=0.01) and was comparable with Brand C (p=0.16). Any reaction observed at 24hours after patch removal subsided in a week. All the three topical formulation of minoxidil 5% were non-irritant. Brand A of 5% minoxidil (Sun Pharma) was found to be least irritant than Brand B and Brand C based on the combined mean score and mean erythema score in the human patch test as per the BIS, IS 4011;2018.

Keywords: erythema, irritation, minoxidil, patch test

Procedia PDF Downloads 96

Authors: Awdhesh Yadav, P. S. Saravanamurthy, Shaikh Tayyaba, Uma Shah, Ashok Agarwal

Abstract:

Objectives: HIV interventions in India has leveraged Self-Help Group (SHG) as one of the key strategies under structural intervention to empower female sex workers (FSW) to reduce their risk exposure and vulnerability to STI/HIV. Understanding the role of SHGs in light of the evolving dynamics of sex work needs to be delved into to strategize HIV interventions among FSWs in India. This paper aims to study the HIV program outcome among the FSWs associated with SHGs and FSWs not associated with SHGs in Thane, Maharashtra. Study Design: This cross-sectional study, was undertaken from the Behavioral Tracking Survey (BTS) conducted among 503 FSWs in Thane in 2015. Two-stage probability based conventional sampling was done for selection of brothel and bar based FSWs, while Time Location Cluster (TLC) sampling was done for home, lodge and street-based sex workers. Methods: Bivariate and multivariate logistic regression were performed to compare and contrast between FSWs associated with SHG and those not associated with SHG with respect to the utilization of HIV related services by them. ‘Condom use’, ‘consistent condom use’, ‘contact with peer-educators’, ‘counseling sessions’ and ‘HIV testing’ were chosen as indicators on HIV service utilization. Results: 8% (38) of FSWs are registered with SHG; 92% aged ≥ 25 years, 47% illiterate, and 71% are currently married. The likelihood of utilizing HIV services including, knowledge on HIV/AIDS and its mode of transmission (OR:5.54; CI: 1.87-16.60; p < 0.05),accessed drop-in Centre (OR: 6.53; CI: 2.15-19.88; p < 0.10), heard about joint health camps (OR: 4.71; CI:2.12-10.46); p < 0.05), negotiated or stood up against police/broker/local goonda/clients (OR: 2.26; CI: 1.08-4.73; p < 0.05), turned away clients when they refused to use condom during sex (OR: 3.76; CI: 1.27-11.15; p < 0.05) and heard of ART (OR; 4.55; CI: 2.18-9.48; p < 0.01) were higher among FSWs associated with SHG in comparison to FSWs not associated with SHG. Conclusions: Considering the improved HIV program outcomes among FSWs associated with SHG; HIV interventions among FSWs could consider facilitating the formation of SHGs with FSWs as one of the key strategies to empower the community for ensuring better program outcomes.

Keywords: empowerment, female sex workers, HIV, Thane, self-help group

Procedia PDF Downloads 237

Authors: Merle Talvik, Taimi Tulva, Kristi Puusepp, Ülle Ernits

Abstract:

Background data. In 1940–1941 and 1945–1991 Estonia was occupied by Soviet Union. Paternalism was a common principle in Soviet social policy, including health care. The Soviet government, not the individuals themselves, decided on achieving a person’s quality of life. With the help of Soviet ideology, the work culture of nurses was constructed and the education system was also reshaped according to the ideology. The “new period of awakening” was initiated under Gorbachev’s perestroika and glasnost (1985–1991), leading to democratization. Aim. The qualitative study aimed to analyze nursing education in Soviet Estonia in the conditions of paternalistic orientation and ideological pressure. Method. The research was conducted in 2021 and 2023. Senior nurses (aged 69–87) who had worked for at least 20 years during the Soviet era were surveyed. Thematic interviews were conducted in written form and orally (13 interviewees), followed by a focus group interview (8 interviewees). A thematic content analysis was performed. Results. Nursing is part of society’s culture and in this sense, in - terviews with nurses provide us with critical information about the functioning of society and cultural identity at a given time. During the Soviet era the training of nurses occured within vocational training institutions. The curricula underwent a shift towards a Soviet-oriented approach. A significant portion of lessons were dedicated to imparting knowledge on the principles and tenets of Communist-Marxist ideology. Therefore, practical subjects and nursing theory were frequently allocated limited space. A paternalistic orientation prevailed in health care: just as the state regulated how to cure, spread hygiene, and healthy lifestyles propaganda, training was also determined by the management of the institution, thereby limiting the person´s autonomy to decide what kind of training was needed. The research is of significant value in the context of the history of nursing, as it helps to understand the difficulties and complexity of the development of nursing on the timeline. The Soviet era still affects Estonian society today and will continue to do so in the future. The same type of developments occurred in other post-Soviet countries.

Keywords: Estonian SSR, nursing education, paternalism, senior nurse, Soviet ideology

Procedia PDF Downloads 67

Authors: Zakaria Kharbouch, Mustapha Bouchaara, F. Elkouihen, A. Habbal, A. Ratnani, A. Faik

Abstract:

Solid-state lithium-ion batteries have garnered increasing interest in modern energy research due to their potential for safer, more efficient, and sustainable energy storage systems. Among the critical components of these batteries, the electrolyte plays a pivotal role, with LLZO garnet-based electrolytes showing significant promise. Garnet materials offer intrinsic advantages such as high Li-ion conductivity, wide electrochemical stability, and excellent compatibility with lithium metal anodes. However, optimizing ionic conductivity in garnet structures poses a complex challenge, primarily due to the multitude of potential dopants that can be incorporated into the LLZO crystal lattice. The complexity of material design, influenced by numerous dopant options, requires a systematic method to find the most effective combinations. This study highlights the utility of machine learning (ML) techniques in the materials discovery process to navigate the complex range of factors in garnet-based electrolytes. Collaborators from the materials science and ML fields worked with a comprehensive dataset previously employed in a similar study and collected from various literature sources. This dataset served as the foundation for an extensive data refinement phase, where meticulous error identification, correction, outlier removal, and garnet-specific feature engineering were conducted. This rigorous process substantially improved the dataset's quality, ensuring it accurately captured the underlying physical and chemical principles governing garnet ionic conductivity. The data refinement effort resulted in a significant improvement in the predictive performance of the machine learning model. Originally starting at an accuracy of 0.32, the model underwent substantial refinement, ultimately achieving an accuracy of 0.88. This enhancement highlights the effectiveness of the interdisciplinary approach and underscores the substantial potential of machine learning techniques in materials science research.

Keywords: lithium batteries, all-solid-state batteries, machine learning, solid state electrolytes

Procedia PDF Downloads 61

Authors: Stefano Sorace, Gloria Terenzi, Giulia Mazzieri, Iacopo Costoli

Abstract:

The prolonged earthquake sequence that struck several urban agglomerations and villages in Central Italy, starting from 24 August 2016 through January 2017, highlighted once again the seismic vulnerability of pre-normative reinforced concrete (R/C) structures. At the same time, considerable damages were surveyed in recently retrofitted R/C buildings too, one of which also by means of a dissipative bracing system. The solution adopted for the latter did not expressly take into account the performance of non-structural elements, and namely of infills and partitions, confirming the importance of their dynamic interaction with the structural skeleton. Based on this consideration, an alternative supplemental damping-based retrofit solution for this representative building, i.e., a school with an R/C structure situated in the municipality of Norcia, is examined in this paper. It consists of the incorporation of dissipative braces equipped with pressurized silicone fluid viscous (FV) dampers, instead of the BRAD system installed in the building, the delayed activation of which -caused by the high stiffness of the constituting metallic dampers- determined the observed non-structural damages. Indeed, the alternative solution proposed herein, characterized by dissipaters with mainly damping mechanical properties, guarantees an earlier activation of the protective system. A careful assessment analysis, preliminarily carried out to simulate and check the case study building performance in originally BRAD-retrofitted conditions, confirms that the interstorey drift demand related to the Norcia earthquake's mainshock and aftershocks is beyond the response capacity of infills. The verification analyses developed on the R/C structure, including the FV-damped braces, highlight their higher performance, giving rise to a completely undamaged response both of structural and non-structural elements up to the basic design earthquake normative level of seismic action.

Keywords: dissipative technologies, performance assessment analysis, concrete structures, seismic retrofit

Procedia PDF Downloads 134

Authors: Mahsa Tavakoli, Seyed Mohammad Hojjati, Yahya Kooch

Abstract:

Considering that coal mining is one of the important industrial activities, it may cause damages to environment. According to the author’s best knowledge, the effect of traditional coal mining activities on plant biodiversity has not been investigated in the Hyrcanian forests. Therefore, in this study, the effect of coal mining activities on vegetation and tree diversity was investigated in Hyrcanian forest, North Iran. After filed visiting and determining the mine, 16 plots (20×20 m²) were established by systematic-randomly (60×60 m²) in an area of 4 ha (200×200 m²-mine entrance placed at center). An area adjacent to the mine was not affected by the mining activity, and it is considered as the control area. In each plot, the data about trees such as number and type of species were recorded. The biodiversity of vegetation cover was considered 5 square sub-plots (1 m²) in each plot. PAST software and Ecological Methodology were used to calculate Biodiversity indices. The value of Shannon Wiener and Simpson diversity indices for tree cover in control area (1.04±0.34 and 0.62±0.20) was significantly higher than mining area (0.78±0.27 and 0.45±0.14). The value of evenness indices for tree cover in the mining area was significantly lower than that of the control area. The value of Shannon Wiener and Simpson diversity indices for vegetation cover in the control area (1.37±0.06 and 0.69±0.02) was significantly higher than the mining area (1.02±0.13 and 0.50±0.07). The value of evenness index in the control area was significantly higher than the mining area. Plant communities are a good indicator of the changes in the site. Study about changes in vegetation biodiversity and plant dynamics in the degraded land can provide necessary information for forest management and reforestation of these areas.

Keywords: vegetation biodiversity, species composition, traditional coal mining, Caspian forest

Procedia PDF Downloads 183

Authors: Ismail Abubakar, Hamid Mehrabi, Reg Morton

Abstract:

Currently, extensive signal analysis is performed in order to evaluate structural health of turbomachinery blades. This approach is affected by constraints of time and the availability of qualified personnel. Thus, new approaches to blade dynamics identification that provide faster and more accurate results are sought after. Generally, modal analysis is employed in acquiring dynamic properties of a vibrating turbomachinery blade and is widely adopted in condition monitoring of blades. The analysis provides useful information on the different modes of vibration and natural frequencies by exploring different shapes that can be taken up during vibration since all mode shapes have their corresponding natural frequencies. Experimental modal testing and finite element analysis are the traditional methods used to evaluate mode shapes with limited application to real live scenario to facilitate a robust condition monitoring scheme. For a real time mode shape evaluation, rapid evaluation and low computational cost is required and traditional techniques are unsuitable. In this study, artificial neural network is developed to evaluate the mode shape of a lab scale rotating blade assembly by using result from finite element modal analysis as training data. The network performance evaluation shows that artificial neural network (ANN) is capable of mapping the correlation between natural frequencies and mode shapes. This is achieved without the need of extensive signal analysis. The approach offers advantage from the perspective that the network is able to classify mode shapes and can be employed in real time including simplicity in implementation and accuracy of the prediction. The work paves the way for further development of robust condition monitoring system that incorporates real time mode shape evaluation.

Keywords: modal analysis, artificial neural network, mode shape, natural frequencies, pattern recognition

Procedia PDF Downloads 156

Authors: Eva Karaskova, Jana Volejnikova, Dusan Holub, Maria Velganova-Veghova, Michaela Spenerova, Dagmar Pospisilova

Abstract:

Background: Hepcidin is the central regulator of iron metabolism. Its production is mainly affected by an iron deficiency and the presence of inflammatory activity in the body. The aim of this study was to compare serum hepcidin levels in paediatric patients with newly diagnosed inflammatory bowel disease and hepcidin levels during maintenance therapy, correlate changes of serum hepcidin levels with selected markers of iron metabolism and inflammation and type of provided treatment. Methods: Children with newly diagnosed Crohn's disease (CD) and ulcerative colitis (UC) were included in this prospective study. Blood and stool samples were collected before treatment (baseline). Serum hepcidin, hemoglobin levels, platelet counts, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL 6), ferritin, iron, soluble transferrin receptors, and fecal calprotectin were assessed. The same parameters were measured and compared with the baseline levels in the follow-up period, during maintenance therapy (average of 39 months after diagnosis). Results: Patients with CD (n=30) had higher serum hepcidin levels (expressed as a median and interquartile range) at diagnosis than subjects with UC (n=13). These levels significantly decreased during the follow-up (from 36.5 (11.5-79.6) ng/ml to 2.1 (0.9-6.7) ng/ml). Contrarily, no significant serum hepcidin level changes were observed in UC (from 5.4 (3.4-16.6) ng/ml to 4.8 (0.9-8.1) ng/ml). While in children with CD hepcidin level dynamics correlated with disease activity and inflammatory markers (ESR, CRP), an only correlation with serum iron levels was observed in patients with UC. Conclusion: Children with CD had higher serum hepcidin levels at diagnosis compared to subjects with UC. Decrease of serum hepcidin in the CD group during anti-inflammatory therapy has been observed, whereas low hepcidin levels in children with UC have remained unchanged. Acknowledgment: This study was supported by grant MH CZ–DRO (FNOl, 00098892).

Keywords: children, Crohn's disease, ulcerative colitis, anaemia, hepcidin

Procedia PDF Downloads 124

Authors: Irma Wani Othman

Abstract:

The internationalization of higher education in Malaysia mainly focuses to place the implementation of the strategic, comprehensive and integrated range of stakeholders in order to highlight the visibility of Malaysia as a hub of academic excellence. While the concept of 'global citizenship' is used as a two-pronged strategy of aggressive marketing by universities which includes; (i) the involvement of the academic expatriates in stimulating international activities of higher education and (ii) an increase in international student enrollment capacity for the enculturation of science and the development of first class mentality. In this aspect, aspirations for a transnational social movement through global citizenship status to establish the identity of the university community without borders (borderless universities) - regardless of skin colour, thus rationalize and liberalize the universal principles of life and cultural traditions of a nation. The education system earlier referred by the spirit of nationalism is now progressing due to globalization, hence forming a system of higher education that is relevant and generated by the need of all time. However, debates arose when the involvement of global citizenship is said to threaten the ultimate university autonomy in determining the direction of academic affairs and governance of their human resources. Stemming from this debate, this study aims to explore the experience of 'global citizenship' that the academic expatriates and international students in shaping the university's strategic needs and interests which are in line with the transition of contemporary higher education. The objective of this study is to examine the acculturation experience of the global citizen in the form of transnational higher education system and suggest policy and policing IHE which refers directly to the experience of the global citizen. This study offers a detailed understanding of how the university communities assess their expatriation experience, thus becoming useful information for learning and transforming education. The findings also open an advanced perspective on the international mobility of human resources and the implications on the implementation of the policy of internationalization of higher education. The contribution of this study is expected to give new input, thus shift the focus of contextual literature for the internationalization of the education system. Instead of focusing on the purpose of generating income of a university, to a greater understanding of subjective experience in utilizing international human resources hence contributing to the prominent transnational character of higher education.

Keywords: internationalization, global citizens, Malaysia higher education, academic expatriate, international students

Procedia PDF Downloads 314

Authors: Pablo Cid Galache, Laura Zamorano Bonilla

Abstract:

Mauriac syndrome (MS) is a rare complication of type 1 diabetes mellitus (DM1). It is rela-ted to low insulin concentrations. Therefore is a complication mainly found in developing countries. The main clinical features are hepatomegaly, edema, growth and puberty delay, and the presence of elevated transaminases and serum lipids. The MS incidence is de-creasing due to the new types of insulin and intensive glycemic control. Therefore is a rare diagnosis in Europe nowadays, being described mainly in developing countries or with so-cioeconomic limitations to guarantee an adequate management of diabetes. Edema secondary to fluid retention is a rare complication of insulin treatment, especially in young patients. Its severity is variable and is mainly related to the start of a proper treatment and the improvement in glycemic control after diagnosis or after periods of poor metabolic control. Edema resolves spontaneously without requiring treatment in most cases. The Pediatric Endocrinology Unit of Hospital Motril could diagnose a 14-year-old girl who presented very poor metabolic control during the last 3 years as a consequence of the socioeconomic conditions of the country of origin during the last years. Presents up to 4 admissions for ketoacidosis during the last 12 months. After the family moved to Spain our patient began to be followed up in our Hospital. Initially presented glycated hemoglobin figures of 11%. One week after the start of treatment, the patient was admitted in the emergency room due to the appearance of generalized edema and pain in the limbs. The main laboratory abnormalities include: blood glucose 225mg/dl; HbA1C 10.8% triglycerides 543 mg/dl, total cholesterol 339 mg/dl (LDL 225) GOT 124 U/l, GPT 89U/l. Abdominal ultrasound shows mild hepatomegaly and no signs of ascites were shown. The patient presented a progressive improvement with resolution of the edema and analitical abnormalities during the next two weeks. During admission, the family received diabetes education, achieving adequate glycemic control at discharge. Nowadays the patient has a good glycemic control having glycated hemoglobin levels around 7%.

Keywords: Mauriac, diabetes, complication, developing countries

Procedia PDF Downloads 54

Authors: Tarcisio F. Leao, Bruno Utiyama, Jeison Fonseca, Eduardo Bock, Aron Andrade

Abstract:

This work presents a blood flow estimator based in Look-Up-Table (LUT) for control of Left Ventricular Assist Device (LVAD). This device has been used as bridge to transplantation or as destination therapy to treat patients with heart failure (HF). Destination Therapy application requires a high performance LVAD; thus, a stable control is important to keep adequate interaction between heart and device. LVAD control provides an adequate cardiac output while sustaining an appropriate flow and pressure blood perfusion, also described as physiologic control. Because thrombus formation and system reliability reduction, sensors are not desirable to measure these variables (flow and pressure blood). To achieve this, control systems have been researched to estimate blood flow. LVAD used in the study is composed by blood centrifugal pump, control, and power supply. This technique used pump and actuator (motor) parameters of LVAD, such as speed and electric current. Estimator relates electromechanical torque (motor or actuator) and hydraulic power (blood pump) via LUT. An in vitro Mock Loop was used to evaluate deviations between blood flow estimated and actual. A solution with glycerin (50%) and water was used to simulate the blood viscosity with hematocrit 45%. Tests were carried out with variation hematocrit: 25%, 45% and 58% of hematocrit, or 40%, 50% and 60% of glycerin in water solution, respectively. Test with bovine blood was carried out (42% hematocrit). Mock Loop is composed: reservoir, tubes, pressure and flow sensors, and fluid (or blood), beyond LVAD. Estimator based in LUT is patented, number BR1020160068363, in Brazil. Mean deviation is 0.23 ± 0.07 L/min for mean flow estimated. Larger mean deviation was 0.5 L/min considering hematocrit variation. This estimator achieved deviation adequate for physiologic control implementation. Future works will evaluate flow estimation performance in control system of LVAD.

Keywords: blood pump, flow estimator, left ventricular assist device, look-up-table

Procedia PDF Downloads 186

Authors: Ntloyalefu Justinah, Fumane Khanare

Abstract:

English learning has been found as one of the prevalent areas of difficulty for Deaf learners. However, studies conducted indicated that this challenge experienced by Deaf learners is an upsetting concern globally as is blamed and hampered by various reasons such as the way English is taught at schools, lack of teachers ' skills and knowledge, therefore, impact negatively on their academic performance. Despite any difficulty in English learning, this language is considered nowadays as the key tool to an educational and occupational career especially in Lesotho. This paper, therefore, intends to contribute to the existing literature by providing the views of Lesotho English teachers, which focuses on how effectively Universal design for learning can be implemented to enhance the academic performance of Deaf learners in context of the English language classroom. The purpose of this study sought to explore the use of universal design for learning (UDL) to support Deaf learners in Lesotho Secondary schools. The present study is informed by interpretative paradigm and situated within a qualitative research approach. Ten participating English teachers from two inclusive schools were purposefully selected and telephonically interviewed to generate data for this study. The data were thematically analysed. The findings indicated that even though UDL is identified as highly proficient and promotes flexibility in teaching methods teachers reflect limited knowledge of the UDL approach. The findings further showed that UDL ensures education for all learners, including marginalised groups, such as learners with disabilities through different teaching strategies. This means that the findings signify the effective use of UDL for the better performance of the English language by Deaf learners (DLs). This aligns with literature that shows mobilizing English teachers as assets help DLs to be engaged and have control in their communities by defining and solving problems using their resources and connections to other networks for asset and exchange. The study, therefore, concludes that teachers acknowledge that even though they assume to be knowledgeable about the definition of UDL, they have a limited practice of the approach, thus they need to be equipped with some techniques and skills to apply for supporting the performance of DLs by using UDL approach in their English teaching. The researchers recommend the awareness of UDL principles by the ministry of Education and Training and teachers training Universities, as well as teachers training colleges, for them to include it in their curricula so that teachers could be properly trained on how to apply it in their teaching effectively

Keywords: deaf learners, Lesotho, support learning, universal design for learning

Procedia PDF Downloads 113

Authors: Bingxi Huang, Yiqing Li, Marek Morzynski, Bernd R. Noack

Abstract:

We propose a Kriging-based global optimization method for active flow control with multiple actuation parameters. This method is designed to converge quickly and avoid getting trapped into local minima. We follow the model-free explorative gradient method (EGM) to alternate between explorative and exploitive steps. This facilitates a convergence similar to a gradient-based method and the parallel exploration of potentially better minima. In contrast to EGM, both kinds of steps are performed with Kriging surrogate model from the available data. The explorative step maximizes the expected improvement, i.e., favors regions of large uncertainty. The exploitive step identifies the best location of the cost function from the Kriging surrogate model for a subsequent weight-biased linear-gradient descent search method. To verify the effectiveness and robustness of the improved Kriging-based optimization method, we have examined several comparative test problems of varying dimensions with limited evaluation budgets. The results show that the proposed algorithm significantly outperforms some model-free optimization algorithms like genetic algorithm and differential evolution algorithm with a quicker convergence for a given budget. We have also performed direct numerical simulations of the fluidic pinball (N. Deng et al. 2020 J. Fluid Mech.) on three circular cylinders in equilateral-triangular arrangement immersed in an incoming flow at Re=100. The optimal cylinder rotations lead to 44.0% net drag power saving with 85.8% drag reduction and 41.8% actuation power. The optimal results for active flow control based on this configuration have achieved boat-tailing mechanism by employing Coanda forcing and wake stabilization by delaying separation and minimizing the wake region.

Keywords: direct numerical simulations, flow control, kriging, stochastic optimization, wake stabilization

Procedia PDF Downloads 106

Authors: Sunil K. Jena, Sanjaya K. Samal, Mahesh Chand, Abhay T. Sangamwar

Abstract:

Tamoxifen (TMX) and its analogues are approved as a first line therapy for the treatment of estrogen receptor-positive tumors. However, clinical development of TMX has been hampered by its low bioavailability and severe hepatotoxicity. Herein, we attempt to design a new drug delivery vehicle that could enhance the pharmacokinetic performance of TMX. Initially, high-molecular weight carboxymethyl chitosan was hydrolyzed to low-molecular weight carboxymethyl chitosan (LMW CMC) with hydrogen peroxide under the catalysis of phosphotungstic acid. Amphiphilic block copolymers of LMW CMC were synthesized via amidation reaction between the carboxyl group of α-tocopherol succinate (TS) and an amine group of LMW CMC. These amphiphilic block copolymers were self-assembled to nanosize core-shell-structural micelles in the aqueous medium. The critical micelle concentration (CMC) decreased with the increasing substitution of TS on LMW CMC, which ranged from 1.58 × 10-6 to 7.94 × 10-8 g/mL. Maximum TMX loading up to 8.08 ± 0.98% was achieved with Cmc-TS4.5 (TMX/Cmc-TS4.5 with 1:8 weight ratio). Both blank and TMX-loaded polymeric micelles (TMX-PM) of Cmc-TS4.5 exhibits spherical shape with the particle size below 200 nm. TMX-PM has been found to be stable in the gastrointestinal conditions and released only 44.5% of the total drug content by the first 72 h in simulated gastric fluid (SGF), pH 1.2. However, the presence of pepsin does not significantly increased the TMX release in SGF, pH 1.2, released only about 46.2% by the first 72 h suggesting its inability to cleave the peptide bond. In contrast, the release of TMX from TMX-PM4.5 in SIF, pH 6.8 (without pancreatin) was slow and sustained, released only about 10.43% of the total drug content within the first 30 min and nearly about 12.41% by the first 72 h. The presence of pancreatin in SIF, pH 6.8 led to an improvement in drug release. About 28.09% of incorporated TMX was released in the presence of pancreatin in 72 h. A cytotoxicity study demonstrated that TMX-PM exhibited time-delayed cytotoxicity in human MCF-7 breast cancer cells. Pharmacokinetic studies on Sprague-Dawley rats revealed a remarkable increase in oral bioavailability (1.87-fold) with significant (p < 0.0001) enhancement in AUC0-72 h, t1/2 and MRT of TMX-PM4.5 than that of TMX-suspension. Thus, the results suggested that CMC-TS micelles are a promising carrier for TMX delivery.

Keywords: carboxymethyl chitosan, d-α-tocopherol succinate, pharmacokinetic, polymeric micelles, tamoxifen

Procedia PDF Downloads 329

Authors: Hacer Erdöl, Merve Aydın, Hacer Kobya Bulut, Kıymet Yeşilçiçek Çalık

Abstract:

Like all occupations, nursing is significantly influenced by the society which it serves and it also affects it. Social structure affects attitudes of nurses, nursing practice, society's attitudes towards nursing and those who have chosen nursing as a profession. People who choose nursing schools take the views of the society’s they live in on nursing to nursing school. Until the 1960s, many nursing schools had not accepted men as students and women had received nursing education and profession had been carried out by women. In our country, in 2007 an amendment to article eight of Nursing Law was passed and with these changes men also began to be able to choose the nursing as a profession. In Turkish, nurse means 'sister'. Hence, in this study to determine the problems that male nursing students likely encounter at the clinic, non-clinical environment and in their private life regarding the title of nurse, among qualitative research methods phenomenological research design was used. Using purpose sampling method, a total of 18 voluntary male students-13 in third grade and 5 in fourth grade at nursing school- were taken to the study. Data were collected through interviews and by the ethical principles much attention was paid to ensure the confidentiality and to protect participants’ identity. During the interviews lasting 30-40 minutes on average, nine pre-configured standard questions were asked and when necessary free questions were also used in order to ensure the clarity of the responses. With pre- configured standard questions, the reasons why students chose the profession, the problems they had in clinical and non-clinical environment and the potential problems they might encounter in their private lives regarding the title of nurse were questioned. Content analysis was performed on data collected and three main themes were obtained. According to the findings of the evaluation of data, it was found that almost all the students preferred the profession due to possible work opportunities, there were students who did not bother nurse title as well as the ones who did bother and as the most important problem they might encounter in their private lives was to feel worried if their kids had to answer "What does your father" question as "my dad is a nurse" and being ridiculed afterwards. The results of this study show that studies should be done to change the social judgment stemmed from the recognition of nursing as a female profession and take advantage of media through creating public spotlight to accomplish this.

Keywords: choice of profession, the title of the profession, title problems, nursing

Procedia PDF Downloads 200