Search results for: array elements
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4216

Search results for: array elements

766 Contribution of the Study of Inclusion Fluids to the Knowledge of the Conditions of Formation of the Layers with SN-W of Central Hoggar, Algeria

Authors: J. Bouguebrine, L. Bouabsa

Abstract:

The ground of study is localized in central Hoggar and contains the most important layers and Stanno-Wolframifére indices of the metallogenic province have tin and wolfram of Hoggar. These layers are always associate with post-orogenetic Panafrican magmatism (GMR) which was set up in the form of circumscribed granitic solid masses of relatively reduced size or in dykes of microgranites. The area studied are in Tounine, Aléméda, Hanana-hananére, Tim Amzi, El Karoussa. The geochemical data processing watch peralumineux character rich person out of Li-F and rare metals (MR). Pegmatites of the type stocksheider, formations of greisens and mineralization Sn-W accompany these granites. Mineralisation Sn-W, expressed particularly well in the seams of quartz and greinsen is spacialement and génitiquement dependent on the maguatism specific to white feldspar-topaz (GMR) (grained and microgrenu). the mineral paragenesis is primarily made up of wolframite and cassetérite. The minerals of gangue are represented by quartz, topaz, the micas containing lithia and the fluorite. A microthermometric study of fluid inclusions related to the granites end on white feldspar-topaz of Hanana, topaz of Hananére, the microgranite of Aléméda, and the seams of quartz D In Tounine (Tiftazouine) and of Tim Amzi; allows to characterize the fluids associated with these layers. It comes out from this study the abundance of aqueous inclusions and three types of fluids were given: -Hot and salted fluids rich in volatile elements particularly CO2; -follow-ups by aquo-carbonic fluids less hot and moderately salted with temperatures of homogenisations (HT) average respectively of 300°C and 180°C; -finally of the aqueous fluids very little salted (≤1%pds.éq.NaCl) and definitely colder. An estimate depths éteé made starting from the diagram of (Haas, 1971) in the system H2O-NaCl, the results are the following: • Inclusion aqueous (L and Lw): correspond to depths of about 50 à500m. • Inclusions aquo-carbonic (Lcw and Lwc): correspond to depths of L order of 600 with 1200m • Carbonic inclusion (Vcw): correspond to depths about 1400à1800m

Keywords: fluid inclusions microthermométrie, cassiterite wolframite, granites with rare metals, Central Hoggar

Procedia PDF Downloads 385
765 A Descriptive Study of the Characteristics of Introductory Accounting Courses Offered by Community Colleges

Authors: Jonathan Nash, Allen Hartt, Catherine Plante

Abstract:

In many nations, community colleges, or similar institutions, play a crucial role in higher education. For example, in the United States more than half of all undergraduate students enroll in a community college at some point during their academic career. Similar statistics have been reported for Australia and Canada. Recognizing the important role these institutions play in educating future accountants, the American Accounting Association has called for research that contributes to a better understanding of these members of the academic community. Although previous literature has shown that community colleges and 4-year institutions differ on many levels, the extant literature has provided data on the characteristics of introductory accounting courses for four-year institutions but not for community colleges. We fill a void in the literature by providing data on the characteristics of introductory accounting courses offered by community colleges in the United States. Data are collected on several dimensions including: course size and staffing, pedagogical orientation, standardization of course elements, textbook selection, and use of technology-based course management tools. Many of these dimensions have been used in previous research examining four-year institutions thereby facilitating comparisons. The resulting data should be of interest to instructors, regulators and administrators, researchers, and the accounting profession. The data provide information on the introductory accounting courses completed by the average community college student which can help instructors identify areas where transfer students’ experiences might differ from their contemporaries at four-year colleges. Regulators and administrators may be interested in the differences between accounting courses offered by two- and four-year institutions when implementing standardized transfer programs. Researchers might use the data to motivate future research into whether differences between two- and four-year institutions affect outcomes like the probability of students choosing to major in accounting and their performance within the major. Accounting professionals may use our findings as a springboard for facilitating discussions related to the accounting labor supply.

Keywords: Accounting curricula, Community college, Descriptive study, Introductory accounting

Procedia PDF Downloads 82
764 A Damage-Plasticity Concrete Model for Damage Modeling of Reinforced Concrete Structures

Authors: Thanh N. Do

Abstract:

This paper addresses the modeling of two critical behaviors of concrete material in reinforced concrete components: (1) the increase in strength and ductility due to confining stresses from surrounding transverse steel reinforcements, and (2) the progressive deterioration in strength and stiffness due to high strain and/or cyclic loading. To improve the state-of-the-art, the author presents a new 3D constitutive model of concrete material based on plasticity and continuum damage mechanics theory to simulate both the confinement effect and the strength deterioration in reinforced concrete components. The model defines a yield function of the stress invariants and a compressive damage threshold based on the level of confining stresses to automatically capture the increase in strength and ductility when subjected to high compressive stresses. The model introduces two damage variables to describe the strength and stiffness deterioration under tensile and compressive stress states. The damage formulation characterizes well the degrading behavior of concrete material, including the nonsymmetric strength softening in tension and compression, as well as the progressive strength and stiffness degradation under primary and follower load cycles. The proposed damage model is implemented in a general purpose finite element analysis program allowing an extensive set of numerical simulations to assess its ability to capture the confinement effect and the degradation of the load-carrying capacity and stiffness of structural elements. It is validated against a collection of experimental data of the hysteretic behavior of reinforced concrete columns and shear walls under different load histories. These correlation studies demonstrate the ability of the model to describe vastly different hysteretic behaviors with a relatively consistent set of parameters. The model shows excellent consistency in response determination with very good accuracy. Its numerical robustness and computational efficiency are also very good and will be further assessed with large-scale simulations of structural systems.

Keywords: concrete, damage-plasticity, shear wall, confinement

Procedia PDF Downloads 148
763 Predictions for the Anisotropy in Thermal Conductivity in Polymers Subjected to Model Flows by Combination of the eXtended Pom-Pom Model and the Stress-Thermal Rule

Authors: David Nieto Simavilla, Wilco M. H. Verbeeten

Abstract:

The viscoelastic behavior of polymeric flows under isothermal conditions has been extensively researched. However, most of the processing of polymeric materials occurs under non-isothermal conditions and understanding the linkage between the thermo-physical properties and the process state variables remains a challenge. Furthermore, the cost and energy required to manufacture, recycle and dispose polymers is strongly affected by the thermo-physical properties and their dependence on state variables such as temperature and stress. Experiments show that thermal conductivity in flowing polymers is anisotropic (i.e. direction dependent). This phenomenon has been previously omitted in the study and simulation of industrially relevant flows. Our work combines experimental evidence of a universal relationship between thermal conductivity and stress tensors (i.e. the stress-thermal rule) with differential constitutive equations for the viscoelastic behavior of polymers to provide predictions for the anisotropy in thermal conductivity in uniaxial, planar, equibiaxial and shear flow in commercial polymers. A particular focus is placed on the eXtended Pom-Pom model which is able to capture the non-linear behavior in both shear and elongation flows. The predictions provided by this approach are amenable to implementation in finite elements packages, since viscoelastic and thermal behavior can be described by a single equation. Our results include predictions for flow-induced anisotropy in thermal conductivity for low and high density polyethylene as well as confirmation of our method through comparison with a number of thermoplastic systems for which measurements of anisotropy in thermal conductivity are available. Remarkably, this approach allows for universal predictions of anisotropy in thermal conductivity that can be used in simulations of complex flows in which only the most fundamental rheological behavior of the material has been previously characterized (i.e. there is no need for additional adjusting parameters other than those in the constitutive model). Accounting for polymers anisotropy in thermal conductivity in industrially relevant flows benefits the optimization of manufacturing processes as well as the mechanical and thermal performance of finalized plastic products during use.

Keywords: anisotropy, differential constitutive models, flow simulations in polymers, thermal conductivity

Procedia PDF Downloads 158
762 Development and Validation of Cylindrical Linear Oscillating Generator

Authors: Sungin Jeong

Abstract:

This paper presents a linear oscillating generator of cylindrical type for hybrid electric vehicle application. The focus of the study is the suggestion of the optimal model and the design rule of the cylindrical linear oscillating generator with permanent magnet in the back-iron translator. The cylindrical topology is achieved using equivalent magnetic circuit considering leakage elements as initial modeling. This topology with permanent magnet in the back-iron translator is described by number of phases and displacement of stroke. For more accurate analysis of an oscillating machine, it will be compared by moving just one-pole pitch forward and backward the thrust of single-phase system and three-phase system. Through the analysis and comparison, a single-phase system of cylindrical topology as the optimal topology is selected. Finally, the detailed design of the optimal topology takes the magnetic saturation effects into account by finite element analysis. Besides, the losses are examined to obtain more accurate results; copper loss in the conductors of machine windings, eddy-current loss of permanent magnet, and iron-loss of specific material of electrical steel. The considerations of thermal performances and mechanical robustness are essential, because they have an effect on the entire efficiency and the insulations of the machine due to the losses of the high temperature generated in each region of the generator. Besides electric machine with linear oscillating movement requires a support system that can resist dynamic forces and mechanical masses. As a result, the fatigue analysis of shaft is achieved by the kinetic equations. Also, the thermal characteristics are analyzed by the operating frequency in each region. The results of this study will give a very important design rule in the design of linear oscillating machines. It enables us to more accurate machine design and more accurate prediction of machine performances.

Keywords: equivalent magnetic circuit, finite element analysis, hybrid electric vehicle, linear oscillating generator

Procedia PDF Downloads 177
761 Creating Legitimate Expectations in International Energy Investments: Role of the Stability Provisions

Authors: Rahmi Kopar

Abstract:

Legitimate expectations principle is considered one of the most dominant elements of the Fair and Equitable Treatment Standard which is today’s most relied upon treaty standard. Since its utilization by arbitral tribunals is relatively new, the contours of the legitimate expectations concept under investment treaty law have not been precisely defined yet. There are various fragmented views arising both from arbitral tribunals and scholarly writings with respect to its limits and use even though the principle is ‘firmly rooted in arbitral practice.’ International energy investments, due to their characteristics, are more prone to certain types of risks, especially the political risks. Thus, there are several mechanisms to protect an energy investment against those risks. Stabilisation is one of these investment protection methods. Stability provisions can be found under domestic legislations, as a contractual clause, or as a separate legal stability agreement. This paper will start by examining the roots of the contentious concept of legitimate expectations with reference to its application in domestic legal systems from where the doctrine under investment treaty law context was transplanted. Then the paper will turn to the investment treaty law and analyse the main contours of the doctrine as understood and applied by arbitral tribunals. 'What gives rise to the investor’s legitimate expectations?' question is answered mainly by three categories of sources: the general legal framework prevalent in a host state, the representations made by the officials or organs of a host state, and the contractual commitments. However, there is no unanimity among the arbitral tribunals and the scholars with respect to the form these sources should take. At this point, the study will discuss the sources of a stability provision and the effect of these stability provisions found in various legal sources in creating a legitimate expectation for the investor. The main questions to be discussed in this paper are as follows: a) Do the stability provisions found under different legal sources create a legitimate expectation on the investor side? b) If yes, what levels of legitimate expectations do they create? These questions will be answered mainly by reference to investment treaty jurisprudence.

Keywords: fair and equitable treatment standard, international energy investments, investment protection, legitimate expectations, stabilization

Procedia PDF Downloads 189
760 Impact of COVID-19 on Antenatal Care Provision at Public Hospitals in Ethiopia: A Mixed Method Study

Authors: Zemenu Yohannes

Abstract:

Introduction: The pandemic overstretched the weak health systems in developing countries, including Ethiopia. This study aims to assess and explore the effect of COVID-19 on antenatal care (ANC) provision. Methods: A concurrent mixed methods study was applied. An interrupted time series design was applied for the quantitative study, and in-depth interviews were implemented for the qualitative research to explore maternity care providers' perceptions of ANC provision during COVID-19. We used routine monthly collected data from the health management information system (HMIS) in fifteen hospitals in the Sidama region, Ethiopia, from March 2019 to February 2020 (12 months) before COVID-19 and from March to August 2020 (6 months) during COVID-19. We imported data into STATA V.17 for analysis. ANC provision's mean monthly incidence rate ratio (IRR) was calculated using Poisson regression with a 95% confidence interval. The qualitative data were analysed using thematic analysis. Findings from quantitative and qualitative elements were integrated with a contiguous approach. Results: Our findings indicate the rate of ANC provision significantly decreased in the first six months of COVID-19. This study has three identified main themes: barriers to ANC provision, inadequate COVID-19 prevention approach, and delay in providing ANC. Conclusion and recommendation: Based on our findings, the pandemic affected ANC provision in the study area. The health bureau and stakeholders should take a novel and sustainable approach to prevent future pandemics. The health bureau and hospital administrators should establish a task force that relies on financial self-reliance to close gaps in future pandemics of medical supply shortages. Pregnant women should receive their care promptly from maternity care providers. In order to foster contact and avoid discrimination the future pandemics, hospital administrators should set up a platform for community members and maternity care providers.

Keywords: ANC provision, COVID-19, mixed methods study, Ethiopia

Procedia PDF Downloads 48
759 When Creativity Is the Solution: How to Transform Makkah into a Creative City

Authors: Saeed Al Amoudy

Abstract:

During the last decade, the rapidly growing prestige of so-called Creative Cities has inspired many other cities seeking to enhance their attractiveness, creativity, and success. However, the concept of a creative city seems to be an elusive one because it reflects a set of distinct ideologies which apply distinct ideas of creativity to physical and economic urban development. The main aim of this study is to investigate the ways in which the theoretical concept of the creative city can be usefully and practically employed to develop the urban services and global identity of Makkah, Saudi Arabia. This is a challenging prospect since no research on creative cities in the Middle East has previously been conducted. The city of Makkah and its holy sites is known as the focus of religious devotion for one and half billion Muslims around the globe, with millions travelling there on annual pilgrimage. The ideas of three of the key authors who have addressed relevant aspects of the concept of the creative city, Landry, Howkins and Florida, were explored in depth for the purpose of identifying the model which would be best suited to Makkah’s identity as a sacred city. Of these, it was the approach of Landry and others whose work was originally focused on finding creative solutions to the problems faced by cities which proved most suitable for the context of Makkah. The development strategies of five case studies of Creative Cities situated in different parts of the world, namely Vancouver, Yokohama, Glasgow, Barcelona, and Sydney, were also examined. Inspired by their diverse experiences, a model, referred to by the acronym CREATIVE, was developed by bringing together the key elements which seemed to ,account for the success of these five creative cities: Concept, Resources, Events, Attractiveness, Technology, Involvement, Vision and Enthusiasm. Expert opinion was sought on the model by presenting this for discussion at five international conferences. This model was used to guide both the process of data collection via interviews, documentation and field notes, and for analysing this, revealing that Makkah has great potential to become a Creative City. The results suggested that implementation of the CREATIVE model in Makkah would help produce creative solutions to address the problems that the city currently faces due to the growing number of pilgrims every year.

Keywords: creative city, city imaging, Makkah, sacred city

Procedia PDF Downloads 381
758 An East-West Trans-Cultural Study: Zen Enlightenment in Asian and John Cage's Visual Arts

Authors: Yu-Shun Elisa Pong

Abstract:

American composer John Cage (1912-1992) is an influential figure in musical, visual and performing arts after World War II and has also been claimed as a forerunner of the western avant-garde in the artistic field. However, the crucial factors contributed to his highly acclaimed achievements include the Zen enlightenment, which he mainly got from Japanese Zen master D. T. Suzuki (1870-1966). As a kind of reflection and afterthought of the Zen inspiration, John Cage created various forms of arts in which visual arts have recently attracted more and more attention and discussion, especially from the perspectives of Zen. John Cage had started to create visual art works since he was 66 years old and the activity had lasted until his death. The quality and quantity of the works are worthy of in-depth study— the 667 pieces of print, 114 pieces of water color, and about 150 pieces of sketch. Cage’s stylistic changes during the 14 years of creation are quite obvious, and the Zen elements in the later works seem to be omnipresent. Based on comparative artistic study, a historical and conceptual view of Zen art that was formed initially in the traditional Chinese and Japanese visual arts will be discussed. Then, Chinese and Japanese representative Zen works will be mentioned, and the technique aspect, as well as stylistic analysis, will be revealed. Finally, a comprehensive comparison of the original Oriental Zen works with John Cage’s works and focus on the influence, and art transformation will be addressed. The master pieces from Zen tradition by Chinese artists like Liang Kai (d. 1210) and Ma Yuan (1160-1225) from Southern Sung Dynasty, the Japanese artists like Sesshū (1420-1506), Miyamoto Musashi (1584-1645) and some others would be discussed. In the current study, these art works from different periods of historical development in Zen will serve as the basis of analogy, interpretation, and criticism to Cage's visual art works. Through the perspectives of the Zen authenticity from Asia, we see how John Cage appropriated the eastern culture to his innovation, which changed the art world forever. And it is believed that through a transition from inter-, cross-, toward trans-cultural inspiration, John Cage set up a unique pathway of art innovations.

Keywords: John Cage, Chinese Zen art, Japanese Zen art, visual art

Procedia PDF Downloads 499
757 Investigation on the Effect of Titanium (Ti) Plus Boron (B) Addition to the Mg-AZ31 Alloy in the as Cast and After Extrusion on Its Metallurgical and Mechanical Characteristics

Authors: Adnan I. O. Zaid, Raghad S. Hemeimat

Abstract:

Magnesium - aluminum alloys are versatile materials which are used in manufacturing a number of engineering and industrial parts in the automobile and aircraft industries due to their strength – to –weight -ratio. Against these preferable characteristics, magnesium is difficult to deform at room temperature therefore it is alloyed with other elements mainly Aluminum and Zinc to add some required properties particularly for their high strength - to -weight ratio. Mg and its alloys oxidize rapidly therefore care should be taken during melting or machining them; but they are not fire hazardous. Grain refinement is an important technology to improve the mechanical properties and the micro structure uniformity of the alloys. Grain refinement has been introduced in early fifties; when Cibula showed that the presence of Ti, and Ti+ B, produced a great refining effect in Al. since then it became an industrial practice to grain refine Al. Most of the published work on grain refinement was directed toward grain refining Al and Zinc alloys; however, the effect of the addition of rare earth material on the grain size or the mechanical behavior of Mg alloys has not been previously investigated. This forms the main objective of the research work; where, the effect of Ti addition on the grain size, mechanical behavior, ductility, and the extrusion force & energy consumed in forward extrusion of Mg-AZ31 alloy is investigated and discussed in two conditions, first in the as cast condition and the second after extrusion. It was found that addition of Ti to Mg- AZ31 alloy has resulted in reduction of its grain size by 14%; the reduction in grain size after extrusion was much higher. However the increase in Vicker’s hardness was 3% after the addition of Ti in the as cast condition, and higher values for Vicker’s hardness were achieved after extrusion. Furthermore, an increase in the strength coefficient by 36% was achieved with the addition of Ti to Mg-AZ31 alloy in the as cast condition. Similarly, the work hardening index was also increased indicating an enhancement of the ductility and formability. As for the extrusion process, it was found that the force and energy required for the extrusion were both reduced by 57% and 59% with the addition of Ti.

Keywords: cast condition, direct extrusion, ductility, MgAZ31 alloy, super - plasticity

Procedia PDF Downloads 434
756 Eco-Design of Construction Industrial Park in China with Selection of Candidate Tenants

Authors: Yang Zhou, Kaijian Li, Guiwen Liu

Abstract:

Offsite construction is an innovative alternative to conventional site-based construction, with wide-ranging benefits. It requires building components, elements or modules were prefabricated and pre-assembly before installed into their final locations. To improve efficiency and achieve synergies, in recent years, construction companies were clustered into construction industrial parks (CIPs) in China. A CIP is a community of construction manufacturing and service businesses located together on a common property. Companies involved in industrial clusters can obtain environment and economic benefits by sharing resources and information in a given region. Therefore, the concept of industrial symbiosis (IS) can be applied to the traditional CIP to achieve sustainable industrial development or redevelopment through the implementation of eco-industrial parks (EIP). However, before designing a symbiosis network between companies in a CIP, candidate support tenants need to be selected to complement the existing construction companies. In this study, an access indicator system and a linear programming model are established to select candidate tenants in a CIP while satisfying the degree of connectivity among the enterprises in the CIP, minimizing the environmental impact, and maximizing the annualized profit of the CIP. The access indicator system comprises three primary indicators and fifteen secondary indicators, is proposed from the perspective of park-based level. The fifteen indicators are classified as three primary indicators including industrial symbiosis, environment performance and economic benefit, according to the three dimensions of sustainability (environment, economic and social dimensions) and the three R's of the environment (reduce, reuse and recycle). The linear programming model is a method to assess the satisfactoriness of all the indicators and to make an optimal multi-objective selection among candidate tenants. This method provides a practical tool for planners of a CIP in evaluating which among the candidate tenants would best complement existing anchor construction tenants. The reasonability and validity of the indicator system and the method is worth further study in the future.

Keywords: construction industrial park, China, industrial symbiosis, offsite construction, selection of support tenants

Procedia PDF Downloads 247
755 Thus Spoke the Mouth: Problematizing Dalit Voice in Selected Poems

Authors: Barnali Saha

Abstract:

Dalit writing is the interventionalist voice of the dispossessed subaltern in the cultural economy of the society. As such, Dalit writing, including Dalit poetry, considers the contradictions that permeate the socio-cultural structure historically allocated and religiously sanctioned in the Indian subcontinent. As an epicenter of all Dalit experiences of trauma and violence, the poetics the Dalit body is deeply rooted in the peripheral space socially assigned to it by anachronistic caste-based litigation. An appraisal of Dalit creative-critical work by writers like Sharan Kumar Limbale, Arjun Dangle, Namdeo Dhasal, Om Prakash Valmiki, Muktibodh and others underscore the conjunction of the physical, psychical and the psychological in their interpretation of Dalit consciousness. They put forward the idea that Dalit poetry is begotten by the trauma of societal oppression and therefore, Dalit language and its revitalization are two elements obdurately linked to Dalit poetics. The present research paper seeks to read the problematization of the Dalit agency through the conduit of the Dalit voice wherein the anatomical category of the mouth is closely related to the question of Dalit identity. Theoretically aligned to Heidegger’s notion of language as the house of being and Bachelard’s assertion of a house as an ideal metaphor of poetic imagination and Dylan Trigg’s view of the coeval existence of space and body, the paper examines a series of selected poems by Dalit poetic voices to examine how their distinct Dalit point of view underscores Dalit speech and directs our attention to the historical abstraction of it. The paper further examines how speech as a category in Dalit writing places the Dalit somatic entity as a site of contestation with the ‘Mouth’ as a loaded symbolic category inspiring rebellion and resistance. And as the quintessential purpose of Dalit literature is the unleashing of Dalit voice from the anti-verbal domain of social decrepitude, Dalit poetry needs to be critically read based on the experience of the mouth and the patois.

Keywords: Dalit, poetry, speech, mouth, subaltern, minority, exploitation, space

Procedia PDF Downloads 169
754 Studies on Radio Frequency Sputtered Copper Zinc Tin Sulphide Absorber Layers for Thin Film Solar Cells

Authors: G. Balaji, R. Balasundaraprabhu, S. Prasanna, M. D. Kannan, K. Sivakumaran, David Mcilroy

Abstract:

Copper Zin tin sulphide (Cu2ZnSnS4 or CZTS) is found to be better alternative to Copper Indium gallium diselenide as absorber layers in thin film based solar cells due to the utilisation of earth-abundant materials in the midst of lower toxicity. In the present study, Cu2ZnSnS4 thin films were prepared on soda lime glass using (CuS, ZnS, SnS) targets and were deposited by three different stacking orders, using RF Magnetron sputtering. The substrate temperature was fixed at 300 °C during the depositions. CZTS thin films were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and UV-Vis-NIR spectroscopy. All the samples exhibited X-ray peaks pertaining to (112) kesterite phase of CZTS, along with the presence of a predominant wurtzite CZTS phase. X-ray photoelectron spectroscopy revealed the presence of all the elements in all the samples. The change in stacking order clearly shows that it affects the structural and phase properties of the films. Relative atomic concentrations of Zn, Cu, Sn and S, which are determined by high-resolution XPS core level spectra integrated peak areas revealed that the CZTS films exhibit inhomogeneity in both stoichiometry and elemental composition. Raman spectroscopy studies on the film showed the presence of CZTS phase. The energy band gap of the CZTS thin films was found to be in the range of 1.5 eV to 1.6 eV. The films were then annealed at 450 °C for 5 hrs and it was found that the predominant nature of the X-ray peaks has transformed from Wurtzite to Kesterite phase which is highly desirable for absorber layers in thin film solar cells. The optimized CZTS layer was used as an absorber layer in thin film solar cells. ZnS and CdS were used as buffer layers which in turn prepared by Hot wall epitaxy technique. Gallium doped Zinc oxide was used as a transparent conducting oxide. The solar cell structure Glass/Mo/CZTS/CdS or ZnS/GZO has been fabricated, and solar cell parameters were measured.

Keywords: earth-abundant, Kesterite, RF sputtering, thin film solar cells

Procedia PDF Downloads 265
753 Magnetic Bio-Nano-Fluids for Hyperthermia

Authors: Z. Kolacinski, L. Szymanski. G. Raniszewski, D. Koza, L. Pietrzak

Abstract:

Magnetic Bio-Nano-Fluid (BNF) can be composed of a buffer fluid such as plasma and magnetic nanoparticles such as iron, nickel, cobalt and their oxides. However iron is one of the best elements for magnetization by electromagnetic radiation. It can be used as a tool for medical diagnosis and treatment. Radio frequency (RF) radiation is able to heat iron nanoparticles due to magnetic hysteresis. Electromagnetic heating of iron nanoparticles and ferro-fluids BNF can be successfully used for non-invasive thermal ablation of cancer cells. Moreover iron atoms can be carried by carbon nanotubes (CNTs) if iron is used as catalyst for CNTs synthesis. Then CNTs became the iron containers and they screen the iron content against oxidation. We will present a method of CNTs addressing to the required cells. For thermal ablation of cancer cells we use radio frequencies for which the interaction with human body should be limited to minimum. Generally, the application of RF energy fields for medical treatment is justified by deep tissue penetration. The highly iron doped CNTs as the carriers creating magnetic fluid will be presented. An excessive catalyst injection method using electrical furnace and microwave plasma reactor will be presented. This way it is possible to grow the Fe filled CNTs on a moving surface in continuous synthesis process. This also allows producing uniform carpet of the Fe filled CNTs carriers. For the experimental work targeted to cell ablation we used RF generator to measure the increase in temperature for some samples like: solution of Fe2O3 in BNF which can be plasma-like buffer, solutions of pure iron of different concentrations in plasma-like buffer and in buffer used for a cell culture, solutions of carbon nanotubes (MWCNTs) of different concentrations in plasma-like buffer and in buffer used for a cell culture. Then the targeted therapies which can be effective if the carriers are able to distinguish the difference between cancerous and healthy cell’s physiology are considered. We have developed an approach based on ligand-receptor or antibody-antigen interactions for the case of colon cancer.

Keywords: cancer treatment, carbon nano tubes, drag delivery, hyperthermia, iron

Procedia PDF Downloads 391
752 Beyond Information Failure and Misleading Beliefs in Conditional Cash Transfer Programs: A Qualitative Account of Structural Barriers Explaining Why the Poor Do Not Invest in Human Capital in Northern Mexico

Authors: Francisco Fernandez de Castro

Abstract:

The Conditional Cash Transfer (CCT) model gives monetary transfers to beneficiary families on the condition that they take specific education and health actions. According to the economic rationale of CCTs the poor need incentives to invest in their human capital because they are trapped by a lack of information and misleading beliefs. If left to their own decision, the poor will not be able to choose what is in their best interests. The basic assumption of the CCT model is that the poor need incentives to take care of their own education and health-nutrition. Due to the incentives (income cash transfers and conditionalities), beneficiary families are supposed to attend doctor visits and health talks. Children would stay in the school. These incentivized behaviors would produce outcomes such as better health and higher level of education, which in turn will reduce poverty. Based on a grounded theory approach to conduct a two-year period of qualitative data collection in northern Mexico, this study shows that this explanation is incomplete. In addition to the information failure and inadequate beliefs, there are structural barriers in everyday life of households that make health-nutrition and education investments difficult. In-depth interviews and observation work showed that the program takes for granted local conditions in which beneficiary families should fulfill their co-responsibilities. Data challenged the program’s assumptions and unveiled local obstacles not contemplated in the program’s design. These findings have policy and research implications for the CCT agenda. They bring elements for late programming due to the gap between the CCT strategy as envisioned by policy designers, and the program that beneficiary families experience on the ground. As for research consequences, these findings suggest new avenues for scholarly work regarding the causal mechanisms and social processes explaining CCT outcomes.

Keywords: conditional cash transfers, incentives, poverty, structural barriers

Procedia PDF Downloads 93
751 Deliberative Democracy: As an Approach for Analyzing Gezi Movement Public Forums

Authors: Çisem Gündüz Arabacı

Abstract:

Deliberation has been seen one of the most important components of democratic ideals especially since liberal democratic attributions have been under fire. Deliberative democracy advocates that people should participate in collective decision-making processes by other mechanisms rather than conventional ones in order to reach legitimate decisions. Deliberative democratic theory makes emphasis on deliberative communication between people and encourages them not to merely express their political opinions (through surveys and referendum) but to form those opinions through public debates. This paper focuses on deliberative democratic visions of Gezi Park Public Forums by taking deliberative democracy as theoretical basis and examining Gezi Park Public Forums in the light of core elements of deliberative democracy. Gezi Movement started on 28 May 2013 in İstanbul as a reaction to local government's revision plans for Taksim Gezi Park, spread throughout the country and created new zones in public sphere which are called Public Park Forums. During the summer of 2013, especially in İstanbul but also in other cities, people gathered in public parks, discussed and took collective decisions concerning actions which they will take. It is worth to mention that since 3 and half years some Public Park Forums are still continuing their meetings regularly in city of İzmir. This paper analyzes four 'Public Park Forums' in İzmir which are called Bornova Public Forum; Karşıyaka Public Forum, Foça Public Forum and Güzelyalı Public Forum. These Forums are under investigation in terms of their understanding of democracy and the values that support that understanding. Participant observation and in-depth interview methods are being used as research methods. Core element of deliberative democracy are being collected under three main category: common interest versus private interest, membership, rational argument and these values are being questioning within one of each Forum in order to draw an overall picture and also make comparison between them. Discourse analysis is being used in order to examine empirical data and paper aims to reveal how participants of public forums perceive deliberative democratic values and whether they give weight to these values.

Keywords: deliberative democracy, Gezi Park movement, public forums, social movement

Procedia PDF Downloads 296
750 Juxtaposing Constitutionalism and Democratic Process in Nigeria Vis a Vis the South African Perspective

Authors: Onyinyechi Lilian Uche

Abstract:

Limiting arbitrariness and political power in governance is expressed in the concept of constitutionalism. Constitutionalism acknowledges the necessity for government but insists upon a limitation being placed upon its powers. It is therefore clear that the essence of constitutionalism is obviation of arbitrariness in governance and maximisation of liberty with adequate and expedient restraint on government. The doctrine of separation of powers accompanied by a system of checks and balances in Nigeria like many other African countries is marked by elements of ‘personal government’ and this has raised questions about whether the apparent separation of powers provided for in the Nigerian Constitution is not just a euphemism for the hegemony of the executive over the other two arms of government; the legislature and the judiciary. Another question raised in the article is whether the doctrine is merely an abstract philosophical inheritance that lacks both content and relevance to the realities of the country and region today? The current happenings in Nigeria and most African countries such as the flagrant disregard of court orders by the Executive, indicate clearly that the concept constitutionalism ordinarily goes beyond mere form and strikes at the substance of a constitution. It, therefore, involves a consideration of whether there are provisions in the constitution which limit arbitrariness in the exercise of political powers by providing checks and balances upon such exercise. These questions underscore the need for Africa to craft its own understanding of the separation of powers between the arms of government in furtherance of good governance as it has been seen that it is possible to have a constitution in place which may just be a mere statement of unenforceable ‘rights’ or may be bereft of provisions guaranteeing liberty or adequate and necessary restraint on exercise of government. This paper seeks to expatiate on the importance of the nexus between constitutionalism and democratic process and a juxtaposition of practices between Nigeria and South Africa. The article notes that an abstract analysis of constitutionalism without recourse to the democratic process is meaningless and also analyses the structure of government of some selected African countries. These are examined the extent to which the doctrine operates within the arms of government and concludes that it should not just be regarded as a general constitutional principle but made rigid or perhaps effective and binding through law and institutional reforms.

Keywords: checks and balances, constitutionalism, democratic process, separation of power

Procedia PDF Downloads 106
749 COVID-19 in Nigeria: An external Analysis from the perspective of social media

Authors: Huseyin Arasli, Maryam Abdullahi, Tugrul Gunay

Abstract:

One of the prominence elements used by the destination marketing organization (DMO) as a marketing strategy is the application of Social media tools. During the current spread of coronavirus disease (COVID-19), travel restriction was placed in most countries of the world, leading to the closure of borders movement. It should be noted that most tourism travelers depend on social media to obtain and exchange different kinds of information about COVID-19 in an unprecedented scale. The situational information people received is valued, which calls for the response of the tourism industry on the epidemic. Therefore, it is highly important to recognize such situational information and to understand how people spread this propaganda on social media platforms so that suitable information that relates the COVID-19 epidemic is available in a manner that will not tarnish the marketing strategies, festival planners. Data for this research study was collected from the desk review, which is a secondary source data, online blogs, and interview through social media chat. The results of this research show that the widespread of COVID-19 pandemics led to rapid lockdown in states and cities all over Nigeria, causing declining demands in hotels, airlines, recreation, and tourism centers. Additionally, billions of dollars lost has been recorded in the high increase of hotels and travel bookings cancellations which caused hundreds and thousands of job loss in the country. The result of this research also revealed that COVID-19 is causing more havoc on the unemployment rate indices of the country. Similarly, the over-dependence of government on petroleum has further caused considerable revenue loss, thereby raising a high poverty rate among less privileged Nigerians. Based on this result, the study suggested that there is an urgent need for the government to diversify its economy by looking at other different sectors such as tourism and agricultural farm produce to harmonize other commercial trades sectors in the country.

Keywords: social media, destination marketing organizations, DMOs, cultural COVID-19, coronavirus, hospitality, travel tour, tourism

Procedia PDF Downloads 80
748 Transient Response of Elastic Structures Subjected to a Fluid Medium

Authors: Helnaz Soltani, J. N. Reddy

Abstract:

Presence of fluid medium interacting with a structure can lead to failure of the structure. Since developing efficient computational model for fluid-structure interaction (FSI) problems has broader impact to realistic problems encountered in aerospace industry, ship industry, oil and gas industry, and so on, one can find an increasing need to find a method in order to investigate the effect of fluid domain on structural response. A coupled finite element formulation of problems involving FSI issue is an accurate method to predict the response of structures in contact with a fluid medium. This study proposes a finite element approach in order to study the transient response of the structures interacting with a fluid medium. Since beam and plate are considered to be the fundamental elements of almost any structure, the developed method is applied to beams and plates benchmark problems in order to demonstrate its efficiency. The formulation is a combination of the various structure theories and the solid-fluid interface boundary condition, which is used to represent the interaction between the solid and fluid regimes. Here, three different beam theories as well as three different plate theories are considered to model the solid medium, and the Navier-Stokes equation is used as the theoretical equation governed the fluid domain. For each theory, a coupled set of equations is derived where the element matrices of both regimes are calculated by Gaussian quadrature integration. The main feature of the proposed methodology is to model the fluid domain as an added mass; the external distributed force due to the presence of the fluid. We validate the accuracy of such formulation by means of some numerical examples. Since the formulation presented in this study covers several theories in literature, the applicability of our proposed approach is independent of any structure geometry. The effect of varying parameters such as structure thickness ratio, fluid density and immersion depth, are studied using numerical simulations. The results indicate that maximum vertical deflection of the structure is affected considerably in the presence of a fluid medium.

Keywords: beam and plate, finite element analysis, fluid-structure interaction, transient response

Procedia PDF Downloads 544
747 Use of Multivariate Statistical Techniques for Water Quality Monitoring Network Assessment, Case of Study: Jequetepeque River Basin

Authors: Jose Flores, Nadia Gamboa

Abstract:

A proper water quality management requires the establishment of a monitoring network. Therefore, evaluation of the efficiency of water quality monitoring networks is needed to ensure high-quality data collection of critical quality chemical parameters. Unfortunately, in some Latin American countries water quality monitoring programs are not sustainable in terms of recording historical data or environmentally representative sites wasting time, money and valuable information. In this study, multivariate statistical techniques, such as principal components analysis (PCA) and hierarchical cluster analysis (HCA), are applied for identifying the most significant monitoring sites as well as critical water quality parameters in the monitoring network of the Jequetepeque River basin, in northern Peru. The Jequetepeque River basin, like others in Peru, shows socio-environmental conflicts due to economical activities developed in this area. Water pollution by trace elements in the upper part of the basin is mainly related with mining activity, and agricultural land lost due to salinization is caused by the extensive use of groundwater in the lower part of the basin. Since the 1980s, the water quality in the basin has been non-continuously assessed by public and private organizations, and recently the National Water Authority had established permanent water quality networks in 45 basins in Peru. Despite many countries use multivariate statistical techniques for assessing water quality monitoring networks, those instruments have never been applied for that purpose in Peru. For this reason, the main contribution of this study is to demonstrate that application of the multivariate statistical techniques could serve as an instrument that allows the optimization of monitoring networks using least number of monitoring sites as well as the most significant water quality parameters, which would reduce costs concerns and improve the water quality management in Peru. Main socio-economical activities developed and the principal stakeholders related to the water management in the basin are also identified. Finally, water quality management programs will also be discussed in terms of their efficiency and sustainability.

Keywords: PCA, HCA, Jequetepeque, multivariate statistical

Procedia PDF Downloads 334
746 Merchants’ Attitudes towards Tourism Development in Mahane Yehuda Market: A Case Study

Authors: Rotem Mashkov, Noam Shoval

Abstract:

In an age when a tourist’s gaze is more focused on the daily lives of locals, it is evident that local food markets are being rediscovered. Traditional urban markets succeed in reinventing themselves as a space for consumption, recreation, and culture, enabling authentic experiences and interpersonal interactions with the local culture. Alongside this, the pressure of tourism development may result in commercialization and retail gentrification to the point of losing the sense of local identity. The issue of finding a balance between tourism development and the preservation of unique local features is at the heart of this study and is being tested using the case of the Mahane Yehuda market in Jerusalem. The research question—how merchants respond to tourism development in the Mahane Yehuda food market— focuses on local traders, a group of players who are usually absent from the research arenas, although they influence tourism development as well as influenced by it. Three main research methods were integrated into this study. The first two methods, a survey of articles survey and comparative mapping of the business mix, were used to characterize the changes in the Mahane Yehuda market both consciously and physically. The third research method, involving in-depth interviews with merchants, was used to examine the traders' attitudes and responses to tourism development. The findings indicate that there has been a turnaround in the market image over the past decade and a half. Additionally, there has been a significant physical change in the business mix, reflected by a decline of 15% in the number of stalls selling food products and delicacies. The data from the interviews on the traders’ attitudes towards tourism development were inconclusive; there were disagreements among the traders about the economic contribution of tourism development in relation to their dependence on the tourism industry. However, there was a consensus on the need for authentic elements in the marketplace. The findings of the study also indicate a strong link between the merchants’ response to tourism development and their stall ownership status as the merchant could exercise their position in various ways depending on the possession type.

Keywords: business mix, Jerusalem, local food markets, Mahane Yehuda market, merchants’ attitude, ownership status, retail gentrification, tourism development, traditional urban markets

Procedia PDF Downloads 113
745 Dematerialized Beings in Katherine Dunn's Geek Love: A Corporeal and Ethical Study under Posthumanities

Authors: Anum Javed

Abstract:

This study identifies the dynamical image of human body that continues its metamorphosis in the virtual field of reality. It calls attention to the ways where humans start co-evolving with other life forms; technology in particular and are striving to establish a realm outside the physical framework of matter. The problem exceeds the area of technological ethics by explicably and explanatorily entering the space of literary texts and criticism. Textual analysis of Geek Love (1989) by Katherine Dunn is adjoined with posthumanist perspectives of Pramod K. Nayar to beget psycho-somatic changes in man’s nature of being. It uncovers the meaning people give to their experiences in this budding social and cultural phenomena of material representation tied up with personal practices and technological innovations. It also observes an ethical, physical and psychological reassessment of man within the context of technological evolutions. The study indicates the elements that have rendered morphological freedom and new materialism in man’s consciousness. Moreover this work is inquisitive of what it means to be a human in this time of accelerating change where surgeries, implants, extensions, cloning and robotics have shaped a new sense of being. It attempts to go beyond individual’s body image and explores how objectifying media and culture have influenced people’s judgement of others on new material grounds. It further argues a decentring of the glorified image of man as an independent entity because of his energetic partnership with intelligent machines and external agents. The history of the future progress of technology is also mentioned. The methodology adopted is posthumanist techno-ethical textual analysis. This work necessitates a negotiating relationship between man and technology in order to achieve harmonic and balanced interconnected existence. The study concludes by recommending a call for an ethical set of codes to be cultivated for the techno-human habituation. Posthumanism ushers a strong need of adopting new ethics within the terminology of neo-materialist humanism.

Keywords: corporeality, dematerialism, human ethos, posthumanism

Procedia PDF Downloads 123
744 Development of a Systematic Approach to Assess the Applicability of Silver Coated Conductive Yarn

Authors: Y. T. Chui, W. M. Au, L. Li

Abstract:

Recently, wearable electronic textiles have been emerging in today’s market and were developed rapidly since, beside the needs for the clothing uses for leisure, fashion wear and personal protection, there also exist a high demand for the clothing to be capable for function in this electronic age, such as interactive interfaces, sensual being and tangible touch, social fabric, material witness and so on. With the requirements of wearable electronic textiles to be more comfortable, adorable, and easy caring, conductive yarn becomes one of the most important fundamental elements within the wearable electronic textile for interconnection between different functional units or creating a functional unit. The properties of conductive yarns from different companies can vary to a large extent. There are vitally important criteria for selecting the conductive yarns, which may directly affect its optimization, prospect, applicability and performance of the final garment. However, according to the literature review, few researches on conductive yarns on shelf focus on the assessment methods of conductive yarns for the scientific selection of material by a systematic way under different conditions. Therefore, in this study, direction of selecting high-quality conductive yarns is given. It is to test the stability and reliability of the conductive yarns according the problems industrialists would experience with the yarns during the every manufacturing process, in which, this assessment system can be classified into four stage. That is 1) Yarn stage, 2) Fabric stage, 3) Apparel stage and 4) End user stage. Several tests with clear experiment procedures and parameters are suggested to be carried out in each stage. This assessment method suggested that the optimal conducting yarns should be stable in property and resistant to various corrosions at every production stage or during using them. It is expected that this demonstration of assessment method can serve as a pilot study that assesses the stability of Ag/nylon yarns systematically at various conditions, i.e. during mass production with textile industry procedures, and from the consumer perspective. It aims to assist industrialists to understand the qualities and properties of conductive yarns and suggesting a few important parameters that they should be reminded of for the case of higher level of suitability, precision and controllability.

Keywords: applicability, assessment method, conductive yarn, wearable electronics

Procedia PDF Downloads 515
743 Biocompatible Beta Titanium Alloy Ti36Nb6Ta as a Suitable Material for Bone Regeneration

Authors: Vera Lukasova, Eva Filova, Jana Dankova, Vera Sovkova, Matej Daniel, Michala Rampichova

Abstract:

Proper bone implants should promote fast adhesion of cells, stimulate cell differentiation and support the formation of bone tissue. Nowadays titanium is used as a biocompatible material capable of bone tissue integration. This study was focused on comparison of bioactive properties of two titanium alloys - beta titanium alloy Ti36Nb6Ta and standard medical titanium alloy Ti6A14V. The advantage of beta titanium alloy Ti36Nb6Ta is mainly that this material does not contain adverse elements like vanadium or aluminium. Titanium alloys were sterilized in ethanol, placed into 48 well plates and seeded with porcine mesenchymal stem cells. Cells were cultivated for 14 days in standard growth cultivation media with osteogenic supplements. Cell metabolic activity was quantified using MTS assay (Promega). Cell adhesion on day 1 and cell proliferation on further days were verified immunohistochemically using beta-actin monoclonal antibody and secondary antibody conjugated with AlexaFluor®488. Differentiation of cells was evaluated using alkaline phosphatase assay. Additionally, gene expression of collagen I was measured by qRT-PCR. Porcine mesenchymal stem cells adhered and spread well on beta titanium alloy Ti36Nb6Ta on day 1. During the 14 days’ time period the cells were spread confluently on the surface of the beta titanium alloy Ti36Nb6Ta. The metabolic activity of cells increased during the whole cultivation period. In comparison to standard medical titanium alloy Ti6A14V, we did not observe any differences. Moreover, the expression of collagen I gene revealed no statistical differences between both titanium alloys. Therefore, a beta titanium alloy Ti36Nb6Ta promotes cell adhesion, metabolic activity, proliferation and collagen I expression equally to standard medical titanium alloy Ti6A14V. Thus, beta titanium is a suitable material that provides sufficient biocompatible properties. This project was supported by the Czech Science Foundation: grant No. 16-14758S.

Keywords: beta titanium alloy, biocompatibility, differentiation, mesenchymal stem cells

Procedia PDF Downloads 470
742 Representation of History in Cinema: Comparative Analysis of Turkish Films Based on the Conquest of Istanbul

Authors: Dilara Balcı Gulpinar

Abstract:

History, which can be defined as the narrative of the past, is a process of reproduction that takes place in current time. Scientificness of historiography is controversial for reasons such as the fact that the historian makes choices and comments; even the reason for choosing the subject distracts him/her from objectivity. Historians may take advantage of the current values, cannot be able to afford to contradict society and/or face pressures of dominant groups. In addition, due to the lack of documentation, interpretation, and fiction are used to integrate historical events that seem disconnected. In this respect, there are views that relate history to narrative arts rather than positive sciences. Popular historical films, which are visual historical representations, appeal to wider audiences by taking advantage of visuality, dramatic fictional narrative, various effects, music, stars, and other populist elements. Historical film, which does not claim to be scientific and even has the freedom to distort historical reality, can be perceived as reality itself and becomes an indispensable resource for individual and social memory. The ideological discourse of popular films is not only impressive and manipulative but also changeable. Socio-cultural and political changes can transform the representation of history in films extremely sharply and rapidly. In accordance with the above-mentioned hypothesis, this study is aimed at examining Turkish historical films about the conquest of Istanbul, using methods of historical and social analysis. İstanbul’un Fethi (Conquest of Istanbul, Aydin Arakon, 1953), Kuşatma Altında Aşk (Love Under Siege, Ersin Pertan, 1997) and Fetih 1453 (Conquest 1453, Faruk Aksoy, 2012) are the only three films in Turkish cinema that revolve around the said conquest, therefore constituting the sample of this study. It has been determined that real and fictional events, as well as characters, both focused and ignored, differ from one another in each film. Such significant differences in the dramatic and cinematographic structure of these three films shot respectively in the 50s, 90s, and 2010s show that the representation of history in popular cinema has altered throughout the years, losing its aspect of objectivity.

Keywords: cinema, conquest of Istanbul, historical film, representation

Procedia PDF Downloads 100
741 [Keynote Talk]: Let Us Move to Ethical Finance: A Case Study of Takaful

Authors: Syed Ahmed Salman

Abstract:

Ethicality is essential in our daily activities, including personal and commercial activities. This is evidenced by referring to the historical development of the corporate governance and ethical guidelines. The first corporate governance guideline, i.e. Cadbury Report from U.K. focuses the responsibility of board members towards the shareholders only. Gradually, realising the need to take care of the society and community, stakeholders are now concerns of business entities. Consequently, later codes of corporate governance started extending the responsibility to the other stakeholders in addition to the shareholders. One prevailing corporate governance theory, i.e. stakeholder theory, has been widely used in the research to explore the effects of business entities on society. In addition, the Global Reporting Initiative (GRI) is the leading organisation which promotes social care from businesses for sustainable development. Conventionally, history shows that ethics is key to the long term success of businesses. Many organisations, societies, and regulators give full attention and consideration to ethics. Several countries have introduced ethical codes of conduct to direct trade activities. Similarly, Islam and other religions prohibit the practice of interest, uncertainty, and gambling because of its unethical nature. These prohibited practices are not at all good for the society, business, and any organisation especially as it is detrimental to the well-being of society. In order to avoid unethicality in the finance industry, Shari’ah scholars come out with the idea of Islamic finance which is free from the prohibited elements from the Islamic perspective. It can also be termed ethical finance. This paper highlights how Takaful as one of the Islamic finance products offers fair and just products to the contracting parties and the society. Takaful is framed based on ethical guidelines which are extracted from Shari’ah principles and divine sources such as the Quran and Sunnah. Takaful products have been widely offered all over the world, including in both Muslim and non-Muslim countries. It seems that it is gaining acceptance regardless of religion. This is evidence that Takaful is being accepted as an ethical financial product.

Keywords: ethics, insurance, Islamic finance, religion and takaful

Procedia PDF Downloads 247
740 CFD Simulation of the Pressure Distribution in the Upper Airway of an Obstructive Sleep Apnea Patient

Authors: Christina Hagen, Pragathi Kamale Gurmurthy, Thorsten M. Buzug

Abstract:

CFD simulations are performed in the upper airway of a patient suffering from obstructive sleep apnea (OSA) that is a sleep related breathing disorder characterized by repetitive partial or complete closures of the upper airways. The simulations are aimed at getting a better understanding of the pathophysiological flow patterns in an OSA patient. The simulation is compared to medical data of a sleep endoscopic examination under sedation. A digital model consisting of surface triangles of the upper airway is extracted from the MR images by a region growing segmentation process and is followed by a careful manual refinement. The computational domain includes the nasal cavity with the nostrils as the inlet areas and the pharyngeal volume with an outlet underneath the larynx. At the nostrils a flat inflow velocity profile is prescribed by choosing the velocity such that a volume flow rate of 150 ml/s is reached. Behind the larynx at the outlet a pressure of -10 Pa is prescribed. The stationary incompressible Navier-Stokes equations are numerically solved using finite elements. A grid convergence study has been performed. The results show an amplification of the maximal velocity of about 2.5 times the inlet velocity at a constriction of the pharyngeal volume in the area of the tongue. It is the same region that also shows the highest pressure drop from about 5 Pa. This is in agreement with the sleep endoscopic examinations of the same patient under sedation showing complete contractions in the area of the tongue. CFD simulations can become a useful tool in the diagnosis and therapy of obstructive sleep apnea by giving insight into the patient’s individual fluid dynamical situation in the upper airways giving a better understanding of the disease where experimental measurements are not feasible. Within this study, it could been shown on one hand that constriction areas within the upper airway lead to a significant pressure drop and on the other hand a good agreement of the area of pressure drop and the area of contraction could be shown.

Keywords: biomedical engineering, obstructive sleep apnea, pharynx, upper airways

Procedia PDF Downloads 282
739 Mathematical Competence as It Is Defined through Learners' Errors in Arithmetic and Algebra

Authors: Michael Lousis

Abstract:

Mathematical competence is the great aim of every mathematical teaching and learning endeavour. This can be defined as an idealised conceptualisation of the quality of cognition and the ability of implementation in practice of the mathematical subject matter, which is included in the curriculum, and is displayed only through performance of doing mathematics. The present study gives a clear definition of mathematical competence in the domains of Arithmetic and Algebra that stems from the explanation of the learners’ errors in these domains. The learners, whose errors are explained, were Greek and English participants of a large, international, longitudinal, comparative research program entitled the Kassel Project. The participants’ errors emerged as results of their work in dealing with mathematical questions and problems of the tests, which were presented to them. The construction of the tests was such as only the outcomes of the participants’ work was to be encompassed and not their course of thinking, which resulted in these outcomes. The intention was that the tests had to provide undeviating comparable results and simultaneously avoid any probable bias. Any bias could stem from obtaining results by involving so many markers from different countries and cultures, with so many different belief systems concerning the assessment of learners’ course of thinking. In this way the validity of the research was protected. This fact forced the implementation of specific research methods and theoretical prospects to take place in order the participants’ erroneous way of thinking to be disclosed. These were Methodological Pragmatism, Symbolic Interactionism, Philosophy of Mind and the ideas of Computationalism, which were used for deciding and establishing the grounds of the adequacy and legitimacy of the obtained kinds of knowledge through the explanations given by the error analysis. The employment of this methodology and of these theoretical prospects resulted in the definition of the learners’ mathematical competence, which is the thesis of the present study. Thus, learners’ mathematical competence is depending upon three key elements that should be developed in their minds: appropriate representations, appropriate meaning, and appropriate developed schemata. This definition then determined the development of appropriate teaching practices and interventions conducive to the achievement and finally the entailment of mathematical competence.

Keywords: representations, meaning, appropriate developed schemata, computationalism, error analysis, explanations for the probable causes of the errors, Kassel Project, mathematical competence

Procedia PDF Downloads 245
738 Temporality, Place and Autobiography in J.M. Coetzee’s 'Summertime'

Authors: Barbara Janari

Abstract:

In this paper it is argued that the effect of the disjunctive temporality in Summertime (the third of J.M. Coetzee’s fictionalised memoirs) is two-fold: firstly, it reflects the memoir’s ambivalent, contradictory representations of place in order to emphasize the fractured sense of self growing up in South Africa during apartheid entailed for Coetzee. Secondly, it reconceives the autobiographical discourse as one that foregrounds the inherent fictionality of all texts. The memoir’s narrative is filtered through intricate textual strategies that disrupt the chronological movement of the narrative, evoking the labyrinthine ways in which the past and present intersect and interpenetrate each other. It is framed by entries from Coetzee’s Notebooks: it opens with entries that cover the years 1972–1975, and ends with a number of undated fragments from his Notebooks. Most of the entries include a short ‘memo’ at the end, added between 1999 and 2000. While the memos follow the Notebook entries in the text, they are separated by decades. Between the Notebook entries is a series of interviews conducted by Vincent, the text’s putative biographer, between 2007 and 2008, based on recollections from five people who had known Coetzee in the 1970s – a key period in John’s life as it marks both his return to South Africa after a failed emigration attempt to America, and the beginning of his writing career, with the publication of Dusklands in 1974. The relationship between the memoir’s various parts is a key feature of Coetzee’s representation of place in Summertime, which is constructed as a composite one in which the principle of reflexive referencing has to be adopted. In other words, readers have to suspend individual references temporarily until the relationships between the parts have been connected to each other. In order to apprehend meaning in the text, the disparate narrative elements have to first be tied together. In this text, then, the experience of time as ordered and chronological is ruptured. Instead, the memoir’s themes and patterns become apparent most clearly through reflexive referencing, by which relationships between disparate sections of the text are linked. The image of the fictional John that emerges from the text is a composite of this John and the author, J.M. Coetzee, and is one which embodies Coetzee’s often fraught relationship with his home country, South Africa.

Keywords: autobiography, place, reflexive referencing, temporality

Procedia PDF Downloads 48
737 The Concentration of Selected Cosmogenic and Anthropogenic Radionuclides in the Ground Layer of the Atmosphere (Polar and Mid-Latitudes Regions)

Authors: A. Burakowska, M. Piotrowski, M. Kubicki, H. Trzaskowska, R. Sosnowiec, B. Myslek-Laurikainen

Abstract:

The most important source of atmospheric radioactivity are radionuclides generated as a result of the impact of primary and secondary cosmic radiation, with the nuclei of nitrogen oxygen and carbon in the upper troposphere and lower stratosphere. This creates about thirty radioisotopes of more than twenty elements. For organisms, the four of them are most important: ³H, ⁷Be, ²²Na, ¹⁴C. The natural radionuclides, which are present in Earth crust, also settle on dust and particles of water vapor. By this means, the derivatives of uranium and thorium, and long-life 40K get into the air. ¹³⁷Cs is the most widespread isotope, that is implemented by humans into the environment. To determine the concentration of radionuclides in the atmosphere, high volume air samplers were used, where the aerosol collection took place on a special filter fabric (Petrianov filter tissue FPP-15-1.5). In 2002 the high volume air sampler AZA-1000 was installed at the Polish Polar Observatory of the Polish Academy of Science in Hornsund, Spitsbergen (77°00’N, 15°33’E), designed to operate in all weather conditions of the cold polar region. Since 1991 (with short breaks) the ASS-500 air sampler has been working, which is located in Swider at the Kalinowski Geophysical Observatory of Geophysics Institute of the Polish Academy of Science (52°07’N, 21°15’E). The following results of radionuclides concentrations were obtained from both stations using gamma spectroscopy analysis: ⁷Be, ¹³⁷Cs, ¹³⁴Cs, ²¹⁰Pb, ⁴⁰K. For gamma spectroscopy analysis HPGe (High Purity Germanium) detector were used. These data were compared with each other. The preliminary results gave evidence that radioactivity measured in aerosols is not proportional to the amount of dust for both studied regions. Furthermore, the results indicate annual variability (seasonal fluctuations) as well as a decrease in the average activity of ⁷Be with increasing latitude. The content of ⁷Be in surface air also indicates the relationship with solar activity cycles.

Keywords: aerosols, air filters, atmospheric beryllium, environmental radionuclides, gamma spectroscopy, mid-latitude regions radionuclides, polar regions radionuclides, solar cycles

Procedia PDF Downloads 115