Search results for: critical flux
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5742

Search results for: critical flux

4902 Using Nanofiber-Like Attapulgite Microfiltration Membranes to Treat Oily Wastewater

Authors: Shouyong Zhou, Meisheng Li, Yijiang Zhao

Abstract:

The environmentally acceptable disposal of oily wastewater is a current challenge to many industries. The membrane separation technologies, which is no phase change, without pharmaceutical dosing, reprocessing costs low, less energy consumption, etc., have been widely applied in oily wastewater treatment. In our lab, a kind of low cost ceramic microfiltration membranes with a separation layer of attapulgite nanofibers (attapulgite nanofiber-like microfiltration membranes) has been prepared and applied in the purification of cellulase fermentation broth and TiO2 nanoparticles system successfully. In this paper, this new attapulgite nanofiber-like microfiltration membrane was selected to try to separate water from oily wastewater. The oil-in water emulsion was obtained from mixing 1 g/L engine oil, 0.5 g/L Tween-80, 0.5 g/L Span-80 and distilled water at mild speed in blender for 2 min. The particle size distribution of the oil-in-water emulsion was controlled. The maximum steady flux and COD rejection for a 0.2 um attapulgite nanofiber-like microfiltration membrane can reach about 450 L. m-2. h-1 and 98% at 0.2 MPa. The results obtained in this work indicated that the attapulgite microfiltration membrane may represent a feasible pretreatment for oily wastewater.

Keywords: attapulgite, microfiltration membrane, oily wastewater, cross-flow filtration

Procedia PDF Downloads 325
4901 Assessment of Biofilm Production Capacity of Industrially Important Bacteria under Electroinductive Conditions

Authors: Omolola Ojetayo, Emmanuel Garuba, Obinna Ajunwa, Abiodun A. Onilude

Abstract:

Introduction: Biofilm is a functional community of microorganisms that are associated with a surface or an interface. These adherent cells become embedded within an extracellular matrix composed of polymeric substances, i.e., biofilms refer to biological deposits consisting of both microbes and their extracellular products on biotic and abiotic surfaces. Despite their detrimental effects in medicine, biofilms as natural cell immobilization have found several applications in biotechnology, such as in the treatment of wastewater, bioremediation and biodegradation, desulfurization of gas, and conversion of agro-derived materials into alcohols and organic acids. The means of enhancing immobilized cells have been chemical-inductive, and this affects the medium composition and final product. Physical factors including electrical, magnetic, and electromagnetic flux have shown potential for enhancing biofilms depending on the bacterial species, nature, and intensity of emitted signals, the duration of exposure, and substratum used. However, the concept of cell immobilisation by electrical and magnetic induction is still underexplored. Methods: To assess the effects of physical factors on biofilm formation, six American typed culture collection (Acetobacter aceti ATCC15973, Pseudomonas aeruginosa ATCC9027, Serratia marcescens ATCC14756, Gluconobacter oxydans ATCC19357, Rhodobacter sphaeroides ATCC17023, and Bacillus subtilis ATCC6633) were used. Standard culture techniques for bacterial cells were adopted. Natural autoimmobilisation potentials of test bacteria were carried out by simple biofilms ring formation on tubes, while crystal violet binding assay techniques were adopted in the characterisation of biofilm quantity. Electroinduction of bacterial cells by direct current (DC) application in cell broth, static magnetic field exposure, and electromagnetic flux were carried out, and autoimmobilisation of cells in a biofilm pattern was determined on various substrata tested, including wood, glass, steel, polyvinylchloride (PVC) and polyethylene terephthalate. Biot Savart law was used in quantifying magnetic field intensity, and statistical analyses of data obtained were carried out using the analyses of variance (ANOVA) as well as other statistical tools. Results: Biofilm formation by the selected test bacteria was enhanced by the physical factors applied. Electromagnetic induction had the greatest effect on biofilm formation, with magnetic induction producing the least effect across all substrata used. Microbial cell-cell communication could be a possible means via which physical signals affected the cells in a polarisable manner. Conclusion: The enhancement of biofilm formation by bacteria using physical factors has shown that their inherent capability as a cell immobilization method can be further optimised for industrial applications. A possible relationship between the presence of voltage-dependent channels, mechanosensitive channels, and bacterial biofilms could shed more light on this phenomenon.

Keywords: bacteria, biofilm, cell immobilization, electromagnetic induction, substrata

Procedia PDF Downloads 178
4900 Disrupting Certainties: Reimagined History Curriculum as Critical Pedagogy in Secondary Teacher Education

Authors: Philippa Hunter

Abstract:

How might history education support teachers and students to see the past as a provocation, be open to possible futures, and act differently? As teacher educators in an age of diversity and uncertainty, we need to question history’s curriculum nature, pedagogy, and policy intent. The cultural politics of history’s identity in the senior secondary curriculum influences educational socialization (disciplinary, professional, research) and engagement with curriculum decision-making. This paper reflects on curriculum disturbance that shaped a critical pedagogy stance to problematize school history’s certainties. The context is situated in an Aotearoa New Zealand university-based initial teacher education programme. A pedagogic innovation was activated whereby problematized history pedagogy [PHP] was conceptualized as the phenomenon and method of inquiry and storied in doctoral work. The PHP was a reciprocal research process involving history class’ participants and the teacher as researcher, in fashioning teaching identities, identifying with, and thinking critically about history pedagogy. PHP findings revealed evocative discourses of embodiment, nostalgia, and connectedness about living ‘inside the past’. Participants expressed certainty about their abilities as teachers living ‘outside the past’ to interpret historical perspectives. However, discomfort was evident in relation to ‘difficult knowledge’ or unfamiliar contexts of the past that exposed exclusion, powerlessness, or silenced voices. Participants identified history programmes as strongly masculine and conflict-focused. A normalized inquiry-transmission approach to history pedagogy was identified and critiqued. Individuals’ reflexive accounts of PHP implemented whilst on practicum indicate possibilities of history pedagogy as; inclusive and democratic, social and ethical reconstruction, and as a critical project. The PHP sought to reimagine history curriculum and identify spaces of possibility in secondary postgraduate teacher education.

Keywords: curriculum, pedagogy, problematise, reciprocal

Procedia PDF Downloads 153
4899 Numerical Simulation of Structured Roughness Effect on Fluid Flow Characteristics and Heat Transfer in Minichannels

Authors: R. Chouatah, E. G. Filali, B. Zouzou

Abstract:

It has been well established that there are no differences between microscale and macroscale flows of incompressible liquids. However, surface roughness has been known to impact the transport phenomena. The effect of structured roughness on the dynamics and heat transfer of water flowing through minichannel was numerically investigated in this study. Our study consists in characterizing the dynamic field and heat transfer aspect of a flow in circular minichannel equipped with structured roughness using CFD software, CFX. The study is performed to understand the effect of various roughness elements (rectangular, triangular), roughness height and roughness pitch on the friction factor and heat transfer coefficient. Our work focuses on a water flow inside a circular mini-channel of 1 mm in diameter and 10 cm in length. The speed entry into the mini-channel varies from 0.1 m/s to 25 m/s. The wall of the mini-channel is submitted to a constant heat flux; q=100,000 W/m². The simulations results are compared to those obtained with smooth minichannel and the existing experimental and numerical results in the literature.

Keywords: heat transfer, laminar and turbulent flow, minichannel, structured roughness

Procedia PDF Downloads 335
4898 The Evaluation of Shear Modulus (Go) Consistency State of Consolidation Cohesive Soils and Seismic Reflection Survey Using Degree of Soil Consolidation

Authors: Abdul Halim Abdul, Wan Ismail Wan Yusoff

Abstract:

The geological formation at Limau Manis Besar area, are consist of low grade metamorphic rock and undulating mountaineers, rugged terrain and the quite steeply 45 degree slope gradient. The objectives of this paper are present the methods and devices used in measurement of P-wave velocity to estimate the initial Shear Modulus (Go) in steady state and critical state soil consolidation. The relationship between SPT-N values and the Shear Modulus (Go) at very small strain is widely considered to be evaluated. Based on the seismic reflection survey, the constant (K) poroelastic theory, mean effectives stress and primer wave velocity (Vs) increase as the soil depth increase. The steady state and critical state, Degree of Soil Consolidation(U) concept is used to interpret the behavior of Shear Modulus (Go). The relationship between Consolidation Test and Seismic Reflection Survey is also discussed.

Keywords: geological setting, shear modulus, poroelastic theory, steady state and none steady state degree of soil consolidation, consolidation test

Procedia PDF Downloads 465
4897 Multi-Criteria Bid/No Bid Decision Support Framework for General Contractors: A Case of Pakistan

Authors: Nida Iftikhar, Jamaluddin Thaheem, Bilal Iftikhar

Abstract:

In the construction industry, adequate and effective decision-making can mean the difference between success and failure. Bidding is the most important element of the construction business since it is a mean by which contractors obtain work. This is probably the only option for any contractor firm to sustain in the market and achieve its objective of earning the profits by winning tenders. The capability to select most appropriate ventures not only defines the success and wellbeing of contractor firms but also their survival and sustainability in the industry. The construction practitioners are usually on their own when it comes to deciding on bidding for a project or not. Usually, experience-based solutions are offered where a lot of subjectivity is involved. This research has been opted considering the local construction industry of Pakistan in order to examine the critical success factors from contractors’ perspective while making bidding decisions, listing and evaluating critical factors in order of their importance, categorization of these factors into decision support & decision oppose groups and to develop a framework to help contractors in the decision-making process. Literature review, questionnaires, and structured interviews are used for identification and quantification of factors affecting bid/no bid decision-making. Statistical methods of ranking analysis and analytical hierarchy process of multi-criteria decision-making method are used for analysis. It is found that profitability, need for work and financial health of client are the most decisive factors in bid/no bid decision-making while project size, project type, fulfilling the tender conditions imposed by the client and relationship, identity & reputation of the client are least impact factors in bid/no bid decision-making. Further, to verify the developed framework, case studies have been conducted to evaluate the bid/no bid decision-making in building procurement. This is the first of its nature study in the context of the local construction industry and recommends using a holistic decision-making framework for such business-critical deliberations.

Keywords: bidding, bid decision-making, construction procurement, contractor

Procedia PDF Downloads 176
4896 Trump’s COVID-19 Discourse: Downgrading the Fundamentals of the Political Fair Play

Authors: Gustavo Naranjo Maroto, Dolores Fernandez Martinez

Abstract:

Context has always been essential to understand any reaction from every human being, and words, whether written or spoken, are definitely a powerful representative sample of human reaction. This study starts with an accurate breakdown of the context in which the current president of the US, Mr. Donald J. Trump is conveying his discourses in order to be able to judge them from a critical discourse analysis point of view. The present world’s scenario with a pandemic disease in form of Covid-19 that is threatening the world and certainly putting at risk the so called 'Welfare State', the role of the United States as the first superpower on earth nowadays, the very peculiar profile of President Trump not only as a politician but as a persona, and the fact of being on the verge of a very controversial presidential elections are without doubt a great and undeniable opportunity for the implementation of the critical discourse analysis methodology. Hence, this research will primarily analyze in detail some of the most interesting discourses delivered by Trump in different media since the very beginning of the outbreak of the coronavirus pandemic in the United States of America (February, 2020), sadly very often downplayed by President Trump, until the final result of the upcoming presidential election scheduled for Tuesday, November 3, 2020, where the political discourse has been dramatically downgraded to a very dangerous state, putting in jeopardy the fundamentals of the political fair play in terms of speech. Finally, the study will hopefully conclude with the final outcome of the data analyzed, allowing to picture how significant the context can be concerning linguistics on the one hand, in terms of shaping or altering the message that the issuer thought to convey in the first place, and on the other hand, generously assessing to what extend the recipients of the message are influenced by the message in terms of receptiveness.

Keywords: Covid-19, critical discourse analysis, Donald J. Trump, political discourse

Procedia PDF Downloads 116
4895 Transient Free Laminar Convection in the Vicinity of a Thermal Conductive Vertical Plate

Authors: Anna Bykalyuk, Frédéric Kuznik, Kévyn Johannes

Abstract:

In this paper, the influence of a vertical plate’s thermal capacity is numerically investigated in order to evaluate the evolution of the thermal boundary layer structure, as well as the convective heat transfer coefficient and the velocity and temperature profiles. Whereas the heat flux of the heated vertical plate is evaluated under time depending boundary conditions. The main important feature of this problem is the unsteadiness of the physical phenomena. A 2D CFD model is developed with the Ansys Fluent 14.0 environment and is validated using unsteady data obtained for plasterboard studied under a dynamic temperature evolution. All the phenomena produced in the vicinity of the thermal conductive vertical plate (plasterboard) are analyzed and discussed. This work is the first stage of a holistic research on transient free convection that aims, in the future, to study the natural convection in the vicinity of a vertical plate containing Phase Change Materials (PCM).

Keywords: CFD modeling, natural convection, thermal conductive plate, time-depending boundary conditions

Procedia PDF Downloads 265
4894 Logical Thinking: A Surprising and Promising Insight for Creative and Critical Thinkers

Authors: Luc de Brabandere

Abstract:

Searchers in various disciplines have long tried to understand how a human being thinks. Most of them seem to agree that the brain works in two very different modes. For us, the first phase of thought imagines, diverges, and unlocks the field of possibilities. The second phase, judges converge and choose. But if we were to stop there, that would give the impression that thought is essentially an individual effort that seldom depends on context. This is, however, not the case. Whether we be a champion in creativity, so primarily in induction, or a master in logic where we are confronted with reality, the ideas we layout are indeed destined to be presented to third parties. They should therefore be exposed, defended, communicated, negotiated, or even sold. Regardless of the quality of the concepts we craft (creative thinking) and the interferences we build (logical thinking) we will take one day, or another, be confronted by people whose beliefs, opinions and ideas differ from ours (critical thinking). Logic and critique: The shared characteristics of logical and critical thoughts include a three-level structure of reasoning invented by the Greeks. For the first time in history, Aristotle tried to model thought deployable in three stages: the concept, the statement, and the reasoning. The three levels can be assessed according to different criteria. A concept is more or less useful, a statement is true or false, and reasoning is right or wrong. This three-level structure allows us to differentiate logic and critique, where the intention and words used are not the same. Logic only deals with the structure of reasoning and exhausts the problem. It regards premises as acquired and excludes the debate. Logic is in all certainty and pursues the truth. Critique is most probably searching for the plausible. Logic and creativity: Many known models present the brain as a two-stroke engine (divergence vs convergence, fast vs. slow, left-brain vs right-brain, Yin vs Yang, etc.). But that’s not the only thing. “Why didn’t we think of that before?” How often have we heard that sentence? A creative idea is the outcome of logic, but you can only understand it afterward! Through the use of exercises, we will witness how logic and creativity work together. A third theme is hidden behind the two main themes of the conference: logical thought, which the author can shed some light on.

Keywords: creativity, logic, critique, digital

Procedia PDF Downloads 80
4893 The Environment in Urban Planning and Management

Authors: Mahmood Salahi, Fatemeh Abbasi

Abstract:

Increasing urbanization will be one of the defining features of the 21st century. This produces particular environmental challenges, but also creates opportunities for urban development that can contribute to broader goals of improving the quality of life for urban residents while achieving greater levels of global sustainability. Half of the world’s population already lives in urban areas, with a growing number of these people living in towns and cities in low and middle-income countries. As well as being a demographic phenomenon, urbanisation is intricately linked with economic, social and environmental transitions. The increasing proportion of the world’s population living in urban areas has been driven by the growing concentration of new investment and employment opportunities. In general, nations with the most rapid and sustained economic growth have urbanized most.2 Urban centres provide opportunities for a range of social and cultural activities, as well as being critical for innovations in science, technology and education. Indeed, urban areas are of critical importance for social and economic development: as the Cities Alliance recognizes, 'only sustained urban growth has the capacity to lift both rural and urban populations out of poverty'.

Keywords: environment, urban planning, management, urbanization

Procedia PDF Downloads 452
4892 Bridge Healthcare Access Gap with Artifical Intelligence

Authors: Moshmi Sangavarapu

Abstract:

The US healthcare industry has undergone tremendous digital transformation in recent years, but critical care access to lower-income ethnicities is still in its nascency. This population has historically showcased substantial hesitation to seek any medical assistance. While the lack of sufficient financial resources plays a critical role, the existing cultural and knowledge barriers also contribute significantly to widening the access gap. It is imperative to break these barriers to ensure timely access to therapeutic procedures that can save important lives! Based on ongoing research, healthcare access barriers can be best addressed by tapping the untapped potential of caregiver communities first. They play a critical role in patients’ diagnoses, building healthcare knowledge and instilling confidence in required therapeutic procedures. Recent technological advancements have opened many avenues by developing smart ways of reaching the large caregiver community. A digitized go-to-market strategy featuring connected media coupled with smart IoT devices and geo-location targeting can be collectively leveraged to reach this key audience group. AI/ML algorithms can be thoroughly trained to identify relevant data signals from users' location and browsing behavior and determine useful marketing touchpoints. The web behavior can be further assimilated with natural language processing to identify contextually relevant interest topics and decipher potential caregivers on digital avenues to serve that brand message. In conclusion, grasping the true health access journey of any lower-income ethnic group is important to design beneficial touchpoints that can alleviate patients’ concerns and allow them to break their own access barriers and opt for timely and quality healthcare.

Keywords: healthcare access, market access, diversity barriers, patient journey

Procedia PDF Downloads 38
4891 Treatment of Industrial Effluents by Using Polyethersulfone/Chitosan Membrane Derived from Fishery Waste

Authors: Suneeta Kumari, Abanti Sahoo

Abstract:

Industrial effluents treatment is a major problem in the world. All wastewater treatment methods have some problems in the environment. Due to this reason, today many natural biopolymers are being used in the waste water treatment because those are safe for our environment. In this study, synthesis and characterization of polyethersulfone/chitosan membranes (Thin film composite membrane) are carried out. Fish scales are used as raw materials. Different characterization techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscope (SEM) and Thermal gravimetric analysis (TGA) are analysed for the synthesized membrane. The performance of membranes such as flux, rejection, and pore size are also checked. The synthesized membrane is used for the treatment of steel industry waste water where Biochemical oxygen demand (BOD), Chemical Oxygen Demand (COD), pH, colour, Total dissolved solids (TDS), Total suspended solids (TSS), Electrical conductivity (EC) and Turbidity aspects are analysed.

Keywords: fish scale, membrane synthesis, treatment of industrial effluents, chitosan

Procedia PDF Downloads 311
4890 Proposals for Continuous Quality Improvement of Public Transportation Federal District Using SERVQUAL

Authors: Rodrigo Guimarães Santos

Abstract:

The quality of public transport services has been considered as a critical factor by their users and also by users of individual transport. Thus, this dissertation aims to adapt a model that assesses the quality of public transport and determines its level of service based on the views of its users. The methodology is widely used by marketers and allows measuring the quality of services by assessing the perceptions and expectations of users. The adapted SERVQUAL was tested with users of public transport service users and car in Brasília-DF, city of Brazil. This research involved 241 questionnaires answered by people living in the various administrative regions of Brasília-DF. The analysis of the determinants pointed out that the quality of the public transport service offered in the city is low and users of public transport and cars have a high degree of expectations for improvement in all tested determinants. This method enabled the identification of the most critical determinants and those needing strategic actions for continuous improvement of quality. Adapting the SERVQUAL for a public transport service was satisfactory and demonstrated applicability to internal and external services, including measuring the public transport services in other cities with the opinion of the users.

Keywords: transportation services, quality services, servqual scale and marketing services

Procedia PDF Downloads 372
4889 Universal Design Building Standard for India: A Critical Inquiry

Authors: Sushil Kumar Solanki, Rachna Khare

Abstract:

Universal Design is a concept of built environment creation, where all people are facilitated to the maximum extent possible without using any type of specialized design. However, accessible design is a design process in which the needs of people with disabilities are specifically considered. Building standards on accessibility contains scoping and technical requirements for accessibility to sites, facilities, building and elements by individual with disability. India is also following its prescriptive types of various building standards for the creation of physical environment for people with disabilities. These building standards are based on western models instead of research based standards to serve Indian needs. These standards lack contextual connect when reflects in its application in the urban and rural environment. This study focuses on critical and comparative study of various international building standards and codes, with existing Indian accessibility standards to understand problems and prospects of concept of Universal Design building standards for India. The result of this study is an analysis of existing state of Indian building standard pertaining to accessibility and future need of performance based Universal Design concept.

Keywords: accessibility, building standard, built-environment, universal design

Procedia PDF Downloads 285
4888 Power, Values, Rules and Leader Decision Making: A Discourse Perspective

Authors: Cathryn Robinson, Bernard McKenna, David Rooney

Abstract:

This paper argues that the application of values-based leadership increasingly challenges leaders in rules-based organisations, particularly in bureaucratic organisations such as the military, public service, police, and emergency services. Leaders are grappling to reconcile how to enact values-based leadership and decision-making when they are bound by rules, policies, and procedures. This interpretive study used a multi-faceted vignette (critical incident) as the basis of an interview with air force officers at three levels: executive, senior, and junior. In this way, practice is forced to intersect with discourse. The findings revealed a shared set of discourse themes (legal; rules; safety and risk; operational practice/theatre discourses), but also clear dialectical tensions. These tensions were evident in executive officers and senior leaders emphasizing rules and information themes, whereas junior officers emphasized decision making, collateral, and situation. These findings reveal discourse and practice incommensurability that could have grave implications in the conduct of war.

Keywords: critical incident, discourse analysis, rules-based, values-based

Procedia PDF Downloads 168
4887 Oil-price Volatility and Economic Prosperity in Nigeria: Empirical Evidence

Authors: Yohanna Panshak

Abstract:

The impact of macroeconomic instability on economic growth and prosperity has been at forefront in many discourses among researchers and policy makers and has generated a lot of controversies over the years. This has generated series of research efforts towards understanding the remote causes of this phenomenon; its nature, determinants and how it can be targeted and mitigated. While others have opined that the root cause of macroeconomic flux in Nigeria is attributed to Oil-Price volatility, others viewed the issue as resulting from some constellation of structural constraints both within and outside the shores of the country. Research works of scholars such as [Akpan (2009), Aliyu (2009), Olomola (2006), etc] argue that oil volatility can determine economic growth or has the potential of doing so. On the contrary, [Darby (1982), Cerralo (2005) etc] share the opinion that it can slow down growth. The earlier argument rest on the understanding that for a net balance of oil exporting economies, price upbeat directly increases real national income through higher export earnings, whereas, the latter allude to the case of net-oil importing countries (which experience price rises, increased input costs, reduced non-oil demand, low investment, fall in tax revenues and ultimately an increase in budget deficit which will further reduce welfare level). Therefore, assessing the precise impact of oil price volatility on virtually any economy is a function of whether it is an oil-exporting or importing nation. Research on oil price volatility and its outcome on the growth of the Nigerian economy are evolving and in a march towards resolving Nigeria’s macroeconomic instability as long as oil revenue still remain the mainstay and driver of socio-economic engineering. Recently, a major importer of Nigeria’s oil- United States made a historic breakthrough in more efficient source of energy for her economy with the capacity of serving significant part of the world. This undoubtedly suggests a threat to the exchange earnings of the country. The need to understand fluctuation in its major export commodity is critical. This paper leans on the Renaissance growth theory with greater focus on theoretical work of Lee (1998); a leading proponent of this school who makes a clear cut of difference between oil price changes and oil price volatility. Based on the above background, the research seeks to empirically examine the impact oil-price volatility on government expenditure using quarterly time series data spanning 1986:1 to 2014:4. Vector Auto Regression (VAR) econometric approach shall be used. The structural properties of the model shall be tested using Augmented Dickey-Fuller and Phillips-Perron. Relevant diagnostics tests of heteroscedasticity, serial correlation and normality shall also be carried out. Policy recommendation shall be offered on the empirical findings and believes it assist policy makers not only in Nigeria but the world-over.

Keywords: oil-price, volatility, prosperity, budget, expenditure

Procedia PDF Downloads 259
4886 Scalar Modulation Technique for Six-Phase Matrix Converter Fed Series-Connected Two-Motor Drives

Authors: A. Djahbar, M. Aillerie, E. Bounadja

Abstract:

In this paper we treat a new structure of a high-power actuator which is used to either industry or electric traction. Indeed, the actuator is constituted by two induction motors, the first is a six-phase motor connected in series with another three-phase motor via the stators. The whole is supplied by a single static converter. Our contribution in this paper is the optimization of the system supply source. This is feeding the multimotor group by a direct converter frequency without using the DC-link capacitor. The modelling of the components of multimotor system is presented first. Only the first component of stator currents is used to produce the torque/flux of the first machine in the group. The second component of stator currents is considered as additional degrees of freedom and which can be used for power conversion for the other connected motors. The decoupling of each motor from the group is obtained using the direct vector control scheme. Simulation results demonstrate the effectiveness of the proposed structure.

Keywords: induction machine, motor drives, scalar modulation technique, three-to-six phase matrix converter

Procedia PDF Downloads 533
4885 Thermal Hydraulic Analysis of the IAEA 10MW Benchmark Reactor under Normal Operating Condition

Authors: Hamed Djalal

Abstract:

The aim of this paper is to perform a thermal-hydraulic analysis of the IAEA 10 MW benchmark reactor solving analytically and numerically, by mean of the finite volume method, respectively the steady state and transient forced convection in rectangular narrow channel between two parallel MTR-type fuel plates, imposed under a cosine shape heat flux. A comparison between both solutions is presented to determine the minimal coolant velocity which can ensure a safe reactor core cooling, where the cladding temperature should not reach a specific safety limit 90 °C. For this purpose, a computer program is developed to determine the principal parameter related to the nuclear core safety, such as the temperature distribution in the fuel plate and in the coolant (light water) as a function of the inlet coolant velocity. Finally, a good agreement is noticed between the both analytical and numerical solutions, where the obtained results are displayed graphically.

Keywords: forced convection, pressure drop, thermal hydraulic analysis, vertical heated rectangular channel

Procedia PDF Downloads 146
4884 The Channels through Which Energy Tax Can Affect Economic Growth: Panel Data Analysis

Authors: Mahmoud Hassan, Walid Oueslati, Damien Rousseliere

Abstract:

This paper explores the channels through which energy taxes may affect economic growth, using a simultaneous equations model for a balanced panel data of 31 OECD countries over the 1994–2013 period. The empirical results reveal a negative impact of energy taxes on physical investment in the short and long term. This impact is negatively sensitive to the existence and level of public debt. Additionally, the results show that energy taxes have an indirect effect on human capital through their impact on polluting emissions. The taxes on energy products are able to reduce both the flux and the stock of polluting emissions that have a negative impact on human capital skills in the short and long term. Finally, we found that energy taxes could encourage eco-innovation in the short and long term.

Keywords: energy taxes, economic growth, public debt, simultaneous equations model, multiple imputation

Procedia PDF Downloads 222
4883 Critical Core Skills Profiling in the Singaporean Workforce

Authors: Bi Xiao Fang, Tan Bao Zhen

Abstract:

Soft skills, core competencies, and generic competencies are exchangeable terminologies often used to represent a similar concept. In the Singapore context, such skills are currently being referred to as Critical Core Skills (CCS). In 2019, SkillsFuture Singapore (SSG) reviewed the Generic Skills and Competencies (GSC) framework that was first introduced in 2016, culminating in the development of the Critical Core Skills (CCS) framework comprising 16 soft skills classified into three clusters. The CCS framework is part of the Skills Framework, and whose stated purpose is to create a common skills language for individuals, employers and training providers. It is also developed with the objectives of building deep skills for a lean workforce, enhance business competitiveness and support employment and employability. This further helps to facilitate skills recognition and support the design of training programs for skills and career development. According to SSG, every job role requires a set of technical skills and a set of Critical Core Skills to perform well at work, whereby technical skills refer to skills required to perform key tasks of the job. There has been an increasing emphasis on soft skills for the future of work. A recent study involving approximately 80 organizations across 28 sectors in Singapore revealed that more enterprises are beginning to recognize that soft skills support their employees’ performance and business competitiveness. Though CCS is of high importance for the development of the workforce’s employability, there is little attention paid to the CCS use and profiling across occupations. A better understanding of how CCS is distributed across the economy will thus significantly enhance SSG’s career guidance services as well as training providers’ services to graduates and workers and guide organizations in their hiring for soft skills. This CCS profiling study sought to understand how CCS is demanded in different occupations. To achieve its research objectives, this study adopted a quantitative method to measure CCS use across different occupations in the Singaporean workforce. Based on the CCS framework developed by SSG, the research team adopted a formative approach to developing the CCS profiling tool to measure the importance of and self-efficacy in the use of CCS among the Singaporean workforce. Drawing on the survey results from 2500 participants, this study managed to profile them into seven occupation groups based on the different patterns of importance and confidence levels of the use of CCS. Each occupation group is labeled according to the most salient and demanded CCS. In the meantime, the CCS in each occupation group, which may need some further strengthening, were also identified. The profiling of CCS use has significant implications for different stakeholders, e.g., employers could leverage the profiling results to hire the staff with the soft skills demanded by the job.

Keywords: employability, skills profiling, skills measurement, soft skills

Procedia PDF Downloads 85
4882 Efficient Monolithic FEM for Compressible Flow and Conjugate Heat Transfer

Authors: Santhosh A. K.

Abstract:

This work presents an efficient monolithic finite element strategy for solving thermo-fluid-structure interaction problems involving compressible fluids and linear-elastic structure. This formulation uses displacement variables for structure and velocity variables for the fluid, with no additional variables required to ensure traction, velocity, temperature, and heat flux continuity at the fluid-structure interface. Rate of convergence in each time step is quadratic, which is achieved in this formulation by deriving an exact tangent stiffness matrix. The robustness and good performance of the method is ascertained by applying the proposed strategy on a wide spectrum of problems taken from the literature pertaining to steady, transient, two dimensional, axisymmetric, and three dimensional fluid flow and conjugate heat transfer. It is shown that the current formulation gives excellent results on all the case studies conducted, which includes problems involving compressibility effects as well as problems where fluid can be treated as incompressible.

Keywords: linear thermoelasticity, compressible flow, conjugate heat transfer, monolithic FEM

Procedia PDF Downloads 183
4881 Failure Mode Effect and Criticality Analysis Based Maintenance Planning through Traditional and Multi-Criteria Decision Making Approach for Aluminium Wire Rolling Mill Plant

Authors: Nilesh Pancholi, Mangal Bhatt

Abstract:

This paper highlights comparative results of traditional FMECA and multi-factor decision-making approach based on “Technique for Order Preference by Similarity to Ideal Solution (TOPSIS)” for aluminum wire rolling mill plant. The suggested study is carried out to overcome the limitations of FMECA by assigning the scores against each failure modes in crisp values to evaluate the criticalities of the failure modes without uncertainty. The primary findings of the paper are that sudden impact on the rolls seems to be most critical failure cause and high contact stresses due to rolling & sliding action of mesh to be least critical failure cause. It is suggested to modify the current control practices with proper maintenance strategy based on achieved maintainability criticality index (MCI). The outcome of the study will be helpful in deriving optimized maintenance plan to maximize the performance of continuous process industry.

Keywords: reliability, maintenance, FMECA, TOPSIS, process industry

Procedia PDF Downloads 268
4880 A Proposal to Integrate Spatially Explicit Ecosystem Services with Urban Metabolic Modelling

Authors: Thomas Elliot, Javier Babi Almenar, Benedetto Rugani

Abstract:

The integration of urban metabolism (UM) with spatially explicit ecosystem service (ES) stocks has the potential to advance sustainable urban development. It will correct the lack of spatially specificity of current urban metabolism models. Furthermore, it will include into UM not only the physical properties of material and energy stocks and flows, but also the implications to the natural capital that provides and maintains human well-being. This paper presents the first stages of a modelling framework by which urban planners can assess spatially the trade-offs of ES flows resulting from urban interventions of different character and scale. This framework allows for a multi-region assessment which takes into account sustainability burdens consequent to an urban planning event occurring elsewhere in the environment. The urban boundary is defined as the Functional Urban Audit (FUA) method to account for trans-administrative ES flows. ES are mapped using CORINE land use within the FUA. These stocks and flows are incorporated into a UM assessment method to demonstrate the transfer and flux of ES arising from different urban planning implementations.

Keywords: ecological economics, ecosystem services, spatial planning, urban metabolism

Procedia PDF Downloads 320
4879 Intentional Relationship Building: Stem Faculty Perceptions of Culturally Responsive Mentoring

Authors: Niesha Douglas, Lisa Merriweather, Cathy Howell, Anna Sancyzk

Abstract:

Many studies explain that mentoring in an academic setting contributes to student success and retention. However, in the United States, where the population is diverse and filled with multiple ethnic groups, mentoring has become too generalized and fails to offer a unique individualized experience for underrepresented minorities (URM). The purpose of this paper is to describe the findings of an ongoing qualitative study that investigates the relationships among STEM doctoral faculty and URM students. Several faculty from three different predominately white institutions (PWI) in the Southeastern region of the United States were interviewed and engaged in open dialogue about their experiences with mentoring. The data collection included semi-structured interviews that took place in the classroom (pre-COVID-19) as well as virtually. The theoretical framework draws on the idea of Critical Race Theory and how cultural, social constructs interfere with effective mentoring for URM Doctoral STEM students. The findings in this study suggest that though the faculty and several years of experience mentoring students, there were some gaps in understanding the needs of URM students and how mentoring is a unique relationship that should be specialized for each student and should not fit into one mold.

Keywords: culture, critical race theory, mentoring, STEM

Procedia PDF Downloads 180
4878 A Critical Discourse Study of Gender Identity Issues in Daniyal Mueenuddin’s Short Story “Saleema”

Authors: Zafar Ali

Abstract:

The aim of this research is to highlight problems that are faced by women at the hands of men. Males in Pakistani society have power and use this power for the exploitation of women. Further, the purpose of the study is to make societies like Pakistan and especially the young generation, aware and enable them to resist such issues, and the role of discourse in this regard is to minimize its political and social repercussions. The study finds out different discursive techniques and manipulative language used in the short story to construct gender identity. The study also investigates socio-economic roles in the construction of gender identity. This study has been completed with the help of Critical Discourse Analysis (CDA) principles. CDA principles have been applied to the text of the selected short story Saleema from Daniyal Mueenuddin’s collection In Other Rooms, Other Wonders. Related passages, structures, expressions, and text are analyzed from the point of view of CDA, especially Norman Fairclough’s CDA approach. It was found from the analysis that women have no identity of their own in patriarchal societies like Pakistan. Further, it was found women are mistreated, and they have a very limited and defined role in Pakistan. They cannot go beyond the limit defined to them by men.

Keywords: gender issues, resourceful groups, CDA, exploitation

Procedia PDF Downloads 124
4877 Effect of Viscous Dissipation and Axial Conduction in Thermally Developing Region of the Channel Partially Filled with a Porous Material Subjected to Constant Wall Heat Flux

Authors: D Bhargavi, J. Sharath Kumar Reddy

Abstract:

The present investigation has been undertaken to assess the effect of viscous dissipation and axial conduction on forced convection heat transfer in the entrance region of a parallel plate channel with the porous insert attached to both walls of the channel. The flow field is unidirectional. Flow in the porous region corresponds to Darcy-Brinkman model and the clear fluid region to that of plane Poiseuille flow. The effects of the parameters Darcy number, Da, Peclet number, Pe, Brinkman number, Br and a porous fraction γp on the local heat transfer coefficient are analyzed graphically. Effects of viscous dissipation employing the Darcy model and the clear fluid compatible model have been studied.

Keywords: porous material, channel partially filled with a porous material, axial conduction, viscous dissipation

Procedia PDF Downloads 146
4876 Examining Influence of The Ultrasonic Power and Frequency on Microbubbles Dynamics Using Real-Time Visualization of Synchrotron X-Ray Imaging: Application to Membrane Fouling Control

Authors: Masoume Ehsani, Ning Zhu, Huu Doan, Ali Lohi, Amira Abdelrasoul

Abstract:

Membrane fouling poses severe challenges in membrane-based wastewater treatment applications. Ultrasound (US) has been considered an effective fouling remediation technique in filtration processes. Bubble cavitation in the liquid medium results from the alternating rarefaction and compression cycles during the US irradiation at sufficiently high acoustic pressure. Cavitation microbubbles generated under US irradiation can cause eddy current and turbulent flow within the medium by either oscillating or discharging energy to the system through microbubble explosion. Turbulent flow regime and shear forces created close to the membrane surface cause disturbing the cake layer and dislodging the foulants, which in turn improve the cleaning efficiency and filtration performance. Therefore, the number, size, velocity, and oscillation pattern of the microbubbles created in the liquid medium play a crucial role in foulant detachment and permeate flux recovery. The goal of the current study is to gain in depth understanding of the influence of the US power intensity and frequency on the microbubble dynamics and its characteristics generated under US irradiation. In comparison with other imaging techniques, the synchrotron in-line Phase Contrast Imaging technique at the Canadian Light Source (CLS) allows in-situ observation and real-time visualization of microbubble dynamics. At CLS biomedical imaging and therapy (BMIT) polychromatic beamline, the effective parameters were optimized to enhance the contrast gas/liquid interface for the accuracy of the qualitative and quantitative analysis of bubble cavitation within the system. With the high flux of photons and the high-speed camera, a typical high projection speed was achieved; and each projection of microbubbles in water was captured in 0.5 ms. ImageJ software was used for post-processing the raw images for the detailed quantitative analyses of microbubbles. The imaging has been performed under the US power intensity levels of 50 W, 60 W, and 100 W, in addition to the US frequency levels of 20 kHz, 28 kHz, and 40 kHz. For the duration of 2 seconds of imaging, the effect of the US power and frequency on the average number, size, and fraction of the area occupied by bubbles were analyzed. Microbubbles’ dynamics in terms of their velocity in water was also investigated. For the US power increase of 50 W to 100 W, the average bubble number and the average bubble diameter were increased from 746 to 880 and from 36.7 µm to 48.4 µm, respectively. In terms of the influence of US frequency, a fewer number of bubbles were created at 20 kHz (average of 176 bubbles rather than 808 bubbles at 40 kHz), while the average bubble size was significantly larger than that of 40 kHz (almost seven times). The majority of bubbles were captured close to the membrane surface in the filtration unit. According to the study observations, membrane cleaning efficiency is expected to be improved at higher US power and lower US frequency due to the higher energy release to the system by increasing the number of bubbles or growing their size during oscillation (optimum condition is expected to be at 20 kHz and 100 W).

Keywords: bubble dynamics, cavitational bubbles, membrane fouling, ultrasonic cleaning

Procedia PDF Downloads 135
4875 Generic Early Warning Signals for Program Student Withdrawals: A Complexity Perspective Based on Critical Transitions and Fractals

Authors: Sami Houry

Abstract:

Complex systems exhibit universal characteristics as they near a tipping point. Among them are common generic early warning signals which precede critical transitions. These signals include: critical slowing down in which the rate of recovery from perturbations decreases over time; an increase in the variance of the state variable; an increase in the skewness of the state variable; an increase in the autocorrelations of the state variable; flickering between different states; and an increase in spatial correlations over time. The presence of the signals has management implications, as the identification of the signals near the tipping point could allow management to identify intervention points. Despite the applications of the generic early warning signals in various scientific fields, such as fisheries, ecology and finance, a review of literature did not identify any applications that address the program student withdrawal problem at the undergraduate distance universities. This area could benefit from the application of generic early warning signals as the program withdrawal rate amongst distance students is higher than the program withdrawal rate at face-to-face conventional universities. This research specifically assessed the generic early warning signals through an intensive case study of undergraduate program student withdrawal at a Canadian distance university. The university is non-cohort based due to its system of continuous course enrollment where students can enroll in a course at the beginning of every month. The assessment of the signals was achieved through the comparison of the incidences of generic early warning signals among students who withdrew or simply became inactive in their undergraduate program of study, the true positives, to the incidences of the generic early warning signals among graduates, the false positives. This was achieved through significance testing. Research findings showed support for the signal pertaining to the rise in flickering which is represented in the increase in the student’s non-pass rates prior to withdrawing from a program; moderate support for the signals of critical slowing down as reflected in the increase in the time a student spends in a course; and moderate support for the signals on increase in autocorrelation and increase in variance in the grade variable. The findings did not support the signal on the increase in skewness of the grade variable. The research also proposes a new signal based on the fractal-like characteristic of student behavior. The research also sought to extend knowledge by investigating whether the emergence of a program withdrawal status is self-similar or fractal-like at multiple levels of observation, specifically the program level and the course level. In other words, whether the act of withdrawal at the program level is also present at the course level. The findings moderately supported self-similarity as a potential signal. Overall, the assessment of the signals suggests that the signals, with the exception with the increase of skewness, could be utilized as a predictive management tool and potentially add one more tool, the fractal-like characteristic of withdrawal, as an additional signal in addressing the student program withdrawal problem.

Keywords: critical transitions, fractals, generic early warning signals, program student withdrawal

Procedia PDF Downloads 174
4874 Impact of Hashtags in Tweets Regarding COVID-19 on the Psyche of Pakistanis: A Critical Discourse Analytical Study

Authors: Muhammad Hamza

Abstract:

This study attempts to analyze the social media reports regarding Covid-19 that impacted the psyche of Pakistanis. This Study is delimited to hashtags from Tweets on a social media platform. During Covid-19, it has been observed that it affected the psychological conditions of Pakistanis. With the application of the three-dimensional model presented by Fairclough, together with a data analytic software “FireAnt” i.e., social media and data analysis toolkit, which is used to filter, identify, report and export data from social media accurately. A detailed and explicit exploration of the various hashtags by users from different fields was conducted. This study conducted a quantitative as well as qualitative methods of analysis. The study examined the perspectives of the Pakistanis behind the use of various hashtags with the lenses of Critical Discourse Analysis (CDA). While conducting this research, CDA was helpful to reveal the connection between the psyche of the people and the Covid-19 pandemic. It was found that how different Pakistanis used social media and how Covid-19 impacted their psyche. After collecting and analyzing the hashtags from twitter it was concluded that majority of people received negative impact from social media reports, while, some people used their hashtags positively and were found positive during Covid-19, and some people were found neutral.

Keywords: Covid, Covid-19, psyche, Covid Pakistan

Procedia PDF Downloads 47
4873 Effect of Education and Occupation on Smokeless Tobacco Use: A Study of Male Adults in India

Authors: Ramu Rawat

Abstract:

Background: This paper is an effort to analyze the role of education and occupation as critical determinants in using smokeless tobacco among male adults in India and its selected states. Methodology: Global Adult Tobacco Survey (GATS) India 2009-10 data have been used for this study. Bivariate and Multivariate (Cox proportion hazards model) analyses are carried out to measure the impact of education and occupation on use of smokeless tobacco among male adults in India. Results and Conclusion: The study evidently suggests that, majority of Indian male adults are using Khaini and Gutkha (local names for smokeless tobacco). The analysis also shows that education and occupation are two important critical predictors of use of smokeless tobacco. The males at younger age with no or little education from rural area use smokeless tobacco more than their counterpart group from urban areas. This distinction can be attributable to their lack of knowledge or ignorance about the consequences of tobacco consumption. Place of residence played significant role for declining use of smokeless tobacco along with the effect of society. Society awareness about harmful effects of smokeless tobacco with local level government may play important role for controlling the use of any type of tobacco or tobacco products in India.

Keywords: smokeless tobacco, male, Khaini, education, occupation

Procedia PDF Downloads 214