Search results for: particle flow code
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7220

Search results for: particle flow code

1340 Effect of Geometry on the Aerodynamic Performance of Darrieus H Yype Vertical Axis Wind Turbine

Authors: Belkheir Noura, Rabah Kerfah, Boumehani Abdellah

Abstract:

The influence of solidity variations on the aerodynamic performance of H type vertical axis wind turbine is studied in this paper. The wind turbine model used in this paper is the three-blade wind turbine with the symmetrical airfoil, NACA0021. The length of the chord is 0.265m. Numerical investigations were implemented for the different solidity by changing the radius and blade number. A two-dimensional model of the wind turbine is employed. The approach a Reynolds-Averaged Navier–Stokes equations, completed by the K- ώ SST turbulence model, is used. Motion mesh model capability of a computational fluid dynamics (CFD) solver is used. For each value of the solidity, the aerodynamics performances and the characteristics of the flow field are studied at several values of the tip speed ratio, λ = 0.5 to λ = 3, with an incoming wind speed of 8 m/s. The results show that increasing the number of blades will reduce the maximum value of the power coefficient of the wind turbine. Also, for the VAWT with a lower solidity can obtain the maximum Cp at a high tip speed ratio. The effects of changing the radius and blade number on aerodynamic performance are almost the same. Finally, for the validation, experimental data from the literature and computational results were compared. In conclusion, to study the influence of the solidity in the performances of the wind turbine is to provide the reference for the design of H type vertical axis wind turbines.

Keywords: wind energy, darrieus h type vertical axis wind turbine, computational fluid dynamic, solidity

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1339 Targeting Tumour Survival and Angiogenic Migration after Radiosensitization with an Estrone Analogue in an in vitro Bone Metastasis Model

Authors: Jolene M. Helena, Annie M. Joubert, Peace Mabeta, Magdalena Coetzee, Roy Lakier, Anne E. Mercier

Abstract:

Targeting the distant tumour and its microenvironment whilst preserving bone density is important in improving the outcomes of patients with bone metastases. 2-Ethyl-3-O-sulphamoyl-estra1,3,5(10)16-tetraene (ESE-16) is an in-silico-designed 2- methoxyestradiol analogue which aimed at enhancing the parent compound’s cytotoxicity and providing a more favourable pharmacokinetic profile. In this study, the potential radiosensitization effects of ESE-16 were investigated in an in vitro bone metastasis model consisting of murine pre-osteoblastic (MC3T3-E1) and pre-osteoclastic (RAW 264.7) bone cells, metastatic prostate (DU 145) and breast (MDA-MB-231) cancer cells, as well as human umbilical vein endothelial cells (HUVECs). Cytotoxicity studies were conducted on all cell lines via spectrophotometric quantification of 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide. The experimental set-up consisted of flow cytometric analysis of cell cycle progression and apoptosis detection (Annexin V-fluorescein isothiocyanate) to determine the lowest ESE-16 and radiation doses to induce apoptosis and significantly reduce cell viability. Subsequent experiments entailed a 24-hour low-dose ESE-16-exposure followed by a single dose of radiation. Termination proceeded 2, 24 or 48 hours thereafter. The effect of the combination treatment was investigated on osteoclasts via tartrate-resistant acid phosphatase (TRAP) activity- and actin ring formation assays. Tumour cell experiments included investigation of mitotic indices via haematoxylin and eosin staining; pro-apoptotic signalling via spectrophotometric quantification of caspase 3; deoxyribonucleic acid (DNA) damage via micronuclei analysis and histone H2A.X phosphorylation (γ-H2A.X); and Western blot analyses of bone morphogenetic protein-7 and matrix metalloproteinase-9. HUVEC experiments included flow cytometric quantification of cell cycle progression and free radical production; fluorescent examination of cytoskeletal morphology; invasion and migration studies on an xCELLigence platform; and Western blot analyses of hypoxia-inducible factor 1-alpha and vascular endothelial growth factor receptor 1 and 2. Tumour cells yielded half-maximal growth inhibitory concentration (GI50) values in the nanomolar range. ESE-16 concentrations of 235 nM (DU 145) and 176 nM (MDA-MB-231) and a radiation dose of 4 Gy were found to be significant in cell cycle and apoptosis experiments. Bone and endothelial cells were exposed to the same doses as DU 145 cells. Cytotoxicity studies on bone cells reported that RAW 264.7 cells were more sensitive to the combination treatment than MC3T3-E1 cells. Mature osteoclasts were more sensitive than pre-osteoclasts with respect to TRAP activity. However, actin ring morphology was retained. The mitotic arrest was evident in tumour and endothelial cells in the mitotic index and cell cycle experiments. Increased caspase 3 activity and superoxide production indicated pro-apoptotic signalling in tumour and endothelial cells. Increased micronuclei numbers and γ-H2A.X foci indicated increased DNA damage in tumour cells. Compromised actin and tubulin morphologies and decreased invasion and migration were observed in endothelial cells. Western blot analyses revealed reduced metastatic and angiogenic signalling. ESE-16-induced radiosensitization inhibits metastatic signalling and tumour cell survival whilst preferentially preserving bone cells. This low-dose combination treatment strategy may promote the quality of life of patients with metastatic bone disease. Future studies will include 3-dimensional in-vitro and murine in-vivo models.

Keywords: angiogenesis, apoptosis, bone metastasis, cancer, cell migration, cytoskeleton, DNA damage, ESE-16, radiosensitization.

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1338 Synthesized Doped TiO2 Photocatalysts for Mineralization of Quinalphos from Aqueous Streams

Authors: Nidhi Sharotri, Dhiraj Sud

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Water pollution by pesticides constitutes a serious ecological problem due to their potential toxicity and bioaccumulation. The widespread use of pesticides in industry and agriculture along with their resistance to natural decomposition, biodegradation, chemical and photochemical degradation under typical environmental conditions has resulted in the emergence of these chemicals and their transformed products in natural water. Among AOP’s, heterogeneous photocatalysis using TiO2 as photocatalyst appears as the most emerging destructive technology for mineralization of the pollutant in aquatic streams. Among the various semiconductors (TiO2, ZnO, CdS, FeTiO3, MnTiO3, SrTiO2 and SnO2), TiO2 has proven to be the most efficient photocatalyst for environmental applications due to its biological and chemical inertness, high photo reactivity, non-toxicity, and photo stability. Semiconductor photocatalysts are characterized by an electronic band structure in which valence band and conduction band are separated by a band gap, i.e. a region of forbidden energy. Semiconductor based photocatalysts produces e-/h+ pairs which have been employed for degradation of organic pollutants. The present paper focuses on modification of TiO2 photocatalyst in order to shift its absorption edge towards longer wavelength to make it active under natural light. Semiconductor TiO2 photocatalysts was prepared by doping with anion (N), cation (Mn) and double doped (Mn, N) using greener approach. Titanium isopropoxide is used as titania precursor and ethanedithiol, hydroxyl amine hydrochloride, manganous chloride as sulphur, nitrogen and manganese precursors respectively. Synthesized doped TiO2 nanomaterials are characterized for surface morphology (SEM, TEM), crystallinity (XRD) and optical properties (absorption spectra and band gap). EPR data confirms the substitutional incorporation of Mn2+ in TiO2 lattice. The doping influences the phase transformation of rutile and anatase phase crystal and thereby the absorption spectrum changes were observed. The effect of variation of reaction parameters such as solvent, reaction time and calcination temperature on the yield, surface morphology and optical properties was also investigated. The TEM studies show the particle size of nanomaterials varies from 10-50 nm. The calculated band gap of nanomaterials varies from 2.30-2.60 eV. The photocatalytic degradation of organic pollutant organophosphate pesticide (Quinalphos) has been investigated by studying the changes in UV absorption spectrum and the promising results were obtained under visible light. The complete mineralization of quinalphos has occurred as no intermediates were recorded after 8 hrs of degradation confirmed from the HPLC studies.

Keywords: quinalphos, doped-TiO2, mineralization, EPR

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1337 Leader Personality Traits and Constructive Voice Behavior: Mediating Roles of Empowering Leadership and Leader-Member Exchange

Authors: Umamaheswara Rao Jada, Susmita Mukhopadhyay

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Employee voice behavior has emerged as an important topic in relation to understanding the paybacks within the organizations. Organizations are expecting employees to contribute in the form of suggestions and ideas that not only help an organization to grow but also survive the turbulent times. Leadership in the organization enables and arouses an individual to offer constructive ideas. The significant impact of leadership is undeniable in a context of creating an environment that promotes a free flow of thoughts and ideas in the organization which in turn is significantly influenced by the personality of the leader. Therefore our study aims at examining the underlying factors which influence employee constructive voice behavior in connection with leader’s personality, empowering form of leadership and leader-member exchange in the organization sequentially. A standardized survey questionnaire was used to collect sample of 272 service executives in India. Smart PLS 2.0 was used to test hypothesis and explore the mediation effect. The result shows that the leader personality traits of agreeableness and conscientiousness were positively related to empowering leadership, whereas neuroticism was unrelated to empowering leadership. Empowering leadership influenced followers’ constructive voice behavior significantly. Furthermore, the relationship was partially mediated by leader member exchange relationship. Theoretical and practical implications of the findings, as well as directions for the future line of research, have been presented in the study.

Keywords: constructive voice, empowering leadership, leader member exchange (LMX), leader personality traits

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1336 Thermally Stimulated Depolarization Current (TSDC) and Transient Current Study in Polysulfone (PSF) and Polyvinylidenefluoride (PVDF) Blends

Authors: S. Patel, T. Mitra, R. Dubey, J. Keller

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In the present investigations, an attempt has been made to study the charge storage mechanism and mechanism for the flow of transient charging and discharging current in an amorphous polymer (Polysulfone) (PSF) and a semi-crystalline polar Polyvinylidene fluoride (PVDF) blends in ratio PSF: PVDF: 80:20;85:15;90:10 and 95:05 at various poling temperatures (i.e. 60, 75, 90 and 1150C) and with field strength (100, 150, 200 and 250kVcm⁻¹). Thermally stimulated depolarizing current TSDC thermograms for (Polysulfone (PSF) and Polyvinylidene fluoride (PVDF) Blends sample have been obtained under different polarizing conditions. Peaks are found at high-temperature side. The variation of structure on blending and poling condition affects the magnitude of TSDC. The activation energy values have been calculated using the initial rise method of Garlick and Gibson. The transient current with the similar polarizing condition has been investigated over a period of 3X10³ sec. The observed characteristics obey Curie-Von Schweidler law in the studied temperature range. The charging current versus polarizing temperature curves at a constant time, i.e., isochronal current characteristics were studied and the activation energies were calculated. The activation energy in transient thermograms calculated by different methods is in good agreement with the values obtained from TSDC studies.

Keywords: activation energy, polysulfone (PSF), polyvinylidenefluoride (PVDF), thermally stimulated depolarizing current (TSDC)

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1335 Pilot Scale Sub-Surface Constructed Wetland: Evaluation of Performance of Bed Vegetated with Water Hyacinth in the Treatment of Domestic Sewage

Authors: Abdul-Hakeem Olatunji Abiola, A. E. Adeniran, A. O. Ajimo, A. B. Lamilisa

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Introduction: Conventional wastewater treatment technology has been found to fail in developing countries because they are expensive to construct, operate and maintain. Constructed wetlands are nowadays considered as a low-cost alternative for effective wastewater treatment, especially where suitable land can be available. This study aims to evaluate the performance of the constructed wetland vegetated with water hyacinth (Eichhornia crassipes) plant for the treatment of wastewater. Methodology: The sub-surface flow wetland used for this study was an experimental scale constructed wetland consisting of four beds A, B, C, and D. Beds A, B, and D were vegetated while bed C which was used as a control was non-vegetated. This present study presents the results from bed B vegetated with water hyacinth (Eichhornia crassipes) and control bed C which was non-vegetated. The influent of the experimental scale wetland has been pre-treated with sedimentation, screening and anaerobic chamber before feeding into the experimental scale wetland. Results: pH and conductivity level were more reduced, colour of effluent was more improved, nitrate, iron, phosphate, and chromium were more removed, and dissolved oxygen was more improved in the water hyacinth bed than the control bed. While manganese, nickel, cyanuric acid, and copper were more removed from the control bed than the water hyacinth bed. Conclusion: The performance of the experimental scale constructed wetland bed planted with water hyacinth (Eichhornia crassipes) is better than that of the control bed. It is therefore recommended that plain bed without any plant should not be encouraged.

Keywords: constructed experimental scale wetland, domestic sewage, treatment, water hyacinth

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1334 Can Zirconia Wings of Resin Retained Cantilever Bridges Be Effectively Bonded To Tooth Tissue When Compared With Metal Wings In The Anterior Dentition in vivo? - A Systematic Review.

Authors: Ariyan S. Araghi, Guy C. Jackson, Stephen J. Bonsor

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Materials & Methods: A systematic literature search was undertaken using pre-determined inclusion and exclusion criteria. This review followed the Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) statement. Several databases were used to search for randomised control trials and longitudinal cohort studies, which were published less than thirty years ago. A total of 54 studies met the predefined inclusion criteria. Four studies reviewed the success, survival, and failure characteristics of zirconia framework resin retained bridges, whilst two reviewed non-precious metal resin retained bridges. Results: The analysis of the studies revealed an overall survival rate of 95.9% for zirconia-based restorations compared to 90.7% for non-precious metal frameworks. Non-precious metal resin retained bridges displayed a higher overall failure rate of 11.9% compared to 4.6% for zirconia-based restorations in the analysed papers. The most frequent complications were wing debonding for the non-precious metal wing group, whereas substructure fracture and veneering ceramic fracture were more prevalent for the zirconia arm of the study. Conclusion: Both types of resin retained bridges provide effective medium to long-term survival. Zirconia-based frameworks will provide marginally increased success and survival and greatly improved aesthetics. However, catastrophic failure is more likely with zirconia-based restorations. Non-precious metal is time tested but performs worse than its zirconia counterpart with regards to longevity; it does not exhibit the same framework fractures as zirconia. Cement choice and attention to the adhesive bonding systems used appear to be paramount to restoration longevity with both restoration subtypes. Furthermore, improved longevity can be seen when air particle abrasion is incorporated into the adhesive protocol. Within the limitations of this study, it has been determined that zirconia-based resin retained bridges can be effectively used in anterior cantilever bridges. Clinical Significance: Zirconia-based resin retained bridges have been demonstrating promising results in terms of improved success and survival characteristics, together with improved aesthetics when compared to non-precious metal winged resin retained bridges. Their popularity is increasing in the age of digital dentistry as many restorations are manufactured using such technology. It is essential that clinicians understand the limitations of each material type and principles of adhesion to ensure restoration longevity.

Keywords: resin retained bridge, fixed partial denture, zirconia bridge, adhesive bridge

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1333 Optimization of Hot Metal Charging Circuit in a Steel Melting Shop Using Industrial Engineering Techniques for Achieving Manufacturing Excellence

Authors: N. Singh, A. Khullar, R. Shrivastava, I. Singh, A. S. Kumar

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Steel forms the basis of any modern society and is essential to economic growth. India’s annual crude steel production has seen a consistent increase over the past years and is poised to grow to 300 million tons per annum by 2030-31 from current level of 110-120 million tons per annum. Steel industry is highly capital-intensive industry and to remain competitive, it is imperative that it invests in operational excellence. Due to inherent nature of the industry, there is large amount of variability in its supply chain both internally and externally. Production and productivity of a steel plant is greatly affected by the bottlenecks present in material flow logistics. The internal logistics constituting of transport of liquid metal within a steel melting shop (SMS) presents an opportunity in increasing the throughput with marginal capital investment. The study was carried out at one of the SMS of an integrated steel plant located in the eastern part of India. The plant has three SMS’s and the study was carried out at one of them. The objective of this study was to identify means to optimize SMS hot metal logistics through application of industrial engineering techniques. The study also covered the identification of non-value-added activities and proposed methods to eliminate the delays and improve the throughput of the SMS.

Keywords: optimization, steel making, supply chain, throughput enhancement, workforce productivity

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1332 Generation of Roof Design Spectra Directly from Uniform Hazard Spectra

Authors: Amin Asgarian, Ghyslaine McClure

Abstract:

Proper seismic evaluation of Non-Structural Components (NSCs) mandates an accurate estimation of floor seismic demands (i.e. acceleration and displacement demands). Most of the current international codes incorporate empirical equations to calculate equivalent static seismic force for which NSCs and their anchorage system must be designed. These equations, in general, are functions of component mass and peak seismic acceleration to which NSCs are subjected to during the earthquake. However, recent studies have shown that these recommendations are suffered from several shortcomings such as neglecting the higher mode effect, tuning effect, NSCs damping effect, etc. which cause underestimation of the component seismic acceleration demand. This work is aimed to circumvent the aforementioned shortcomings of code provisions as well as improving them by proposing a simplified, practical, and yet accurate approach to generate acceleration Floor Design Spectra (FDS) directly from corresponding Uniform Hazard Spectra (UHS) (i.e. design spectra for structural components). A database of 27 Reinforced Concrete (RC) buildings in which Ambient Vibration Measurements (AVM) have been conducted. The database comprises 12 low-rise, 10 medium-rise, and 5 high-rise buildings all located in Montréal, Canada and designated as post-disaster buildings or emergency shelters. The buildings are subjected to a set of 20 compatible seismic records and Floor Response Spectra (FRS) in terms of pseudo acceleration are derived using the proposed approach for every floor of the building in both horizontal directions considering 4 different damping ratios of NSCs (i.e. 2, 5, 10, and 20% viscous damping). Several effective parameters on NSCs response are evaluated statistically. These parameters comprise NSCs damping ratios, tuning of NSCs natural period with one of the natural periods of supporting structure, higher modes of supporting structures, and location of NSCs. The entire spectral region is divided into three distinct segments namely short-period, fundamental period, and long period region. The derived roof floor response spectra for NSCs with 5% damping are compared with the 5% damping UHS and procedure are proposed to generate roof FDS for NSCs with 5% damping directly from 5% damped UHS in each spectral region. The generated FDS is a powerful, practical, and accurate tool for seismic design and assessment of acceleration-sensitive NSCs particularly in existing post-critical buildings which have to remain functional even after the earthquake and cannot tolerate any damage to NSCs.

Keywords: earthquake engineering, operational and functional components (OFCs), operational modal analysis (OMA), seismic assessment and design

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1331 Artificial Intelligence and Robotics in the Eye of Private Law with Special Regards to Intellectual Property and Liability Issues

Authors: Barna Arnold Keserű

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In the last few years (what is called by many scholars the big data era) artificial intelligence (hereinafter AI) get more and more attention from the public and from the different branches of sciences as well. What previously was a mere science-fiction, now starts to become reality. AI and robotics often walk hand in hand, what changes not only the business and industrial life, but also has a serious impact on the legal system. The main research of the author focuses on these impacts in the field of private law, with special regards to liability and intellectual property issues. Many questions arise in these areas connecting to AI and robotics, where the boundaries are not sufficiently clear, and different needs are articulated by the different stakeholders. Recognizing the urgent need of thinking the Committee on Legal Affairs of the European Parliament adopted a Motion for a European Parliament Resolution A8-0005/2017 (of January 27th, 2017) in order to take some recommendations to the Commission on civil law rules on robotics and AI. This document defines some crucial usage of AI and/or robotics, e.g. the field of autonomous vehicles, the human job replacement in the industry or smart applications and machines. It aims to give recommendations to the safe and beneficial use of AI and robotics. However – as the document says – there are no legal provisions that specifically apply to robotics or AI in IP law, but that existing legal regimes and doctrines can be readily applied to robotics, although some aspects appear to call for specific consideration, calls on the Commission to support a horizontal and technologically neutral approach to intellectual property applicable to the various sectors in which robotics could be employed. AI can generate some content what worth copyright protection, but the question came up: who is the author, and the owner of copyright? The AI itself can’t be deemed author because it would mean that it is legally equal with the human persons. But there is the programmer who created the basic code of the AI, or the undertaking who sells the AI as a product, or the user who gives the inputs to the AI in order to create something new. Or AI generated contents are so far from humans, that there isn’t any human author, so these contents belong to public domain. The same questions could be asked connecting to patents. The research aims to answer these questions within the current legal framework and tries to enlighten future possibilities to adapt these frames to the socio-economical needs. In this part, the proper license agreements in the multilevel-chain from the programmer to the end-user become very important, because AI is an intellectual property in itself what creates further intellectual property. This could collide with data-protection and property rules as well. The problems are similar in the field of liability. We can use different existing forms of liability in the case when AI or AI led robotics cause damages, but it is unsure that the result complies with economical and developmental interests.

Keywords: artificial intelligence, intellectual property, liability, robotics

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1330 Management Strategies for Risk Events in Construction Industries during Economic Situation and COVID-19 Pandemic in Nigeria

Authors: Ezeabasili Chibuike Patrick

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The complex situation of construction industries in Nigeria and the risk of failures involved includes cost overrun, time overrun, Corruption, Government influence, Subcontractor challenges, Political influence and Instability, Cultural differences, Human resources deficiencies, cash flow Challenges, foreign exchange issues, inadequate design, Safety, low productivity, late payment, Quality control issues, project management issues, Environmental issues, Force majeure Competition amongst others has made the industry prone to risk and failures. Good project management remains effective in improving decision-making, which minimizes these risk events. This study was done to address these project risks and good decision-making to avert them. A mixed-method approach to research was used to do this study. Data collected by questionnaires and interviews on thirty-two (32) construction professionals was used in analyses to aid the knowledge and management of risks that were identified. The study revealed that there is no good risk management expertise in Nigeria. Also, that the economic/political situation and the recent COVID-19 pandemic has added to the risk and poor management strategies. The contingency theory and cost has therefore surfaced to be the most strategic management method used to reduce these risk issues and they seem to be very effective.

Keywords: strategies, risk management, contingency theory, Nigeria

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1329 Sensitivity Analysis Optimization of a Horizontal Axis Wind Turbine from Its Aerodynamic Profiles

Authors: Kevin Molina, Daniel Ortega, Manuel Martinez, Andres Gonzalez-Estrada, William Pinto

Abstract:

Due to the increasing environmental impact, the wind energy is getting strong. This research studied the relationship between the power produced by a horizontal axis wind turbine (HAWT) and the aerodynamic profiles used for its construction. The analysis is studied using the Computational Fluid Dynamic (CFD), presenting the parallel between the energy generated by a turbine designed with selected profiles and another one optimized. For the study, a selection process was carried out from profile NACA 6 digits recommended by the National Renewable Energy Laboratory (NREL) for the construction of this type of turbines. The selection was taken into account different characteristics of the wind (speed and density) and the profiles (aerodynamic coefficients Cl and Cd to different Reynolds and incidence angles). From the selected profiles, was carried out a sensitivity analysis optimization process between its geometry and the aerodynamic forces that are induced on it. The 3D model of the turbines was realized using the Blade Element Momentum method (BEM) and both profiles. The flow fields on the turbines were simulated, obtaining the forces induced on the blade, the torques produced and an increase of 3% in power due to the optimized profiles. Therefore, the results show that the sensitivity analysis optimization process can assist to increment the wind turbine power.

Keywords: blade element momentum, blade, fluid structure interaction, horizontal axis wind turbine, profile design

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1328 Virtual Prototyping of LED Chip Scale Packaging Using Computational Fluid Dynamic and Finite Element Method

Authors: R. C. Law, Shirley Kang, T. Y. Hin, M. Z. Abdullah

Abstract:

LED technology has been evolving aggressively in recent years from incandescent bulb during older days to as small as chip scale package. It will continue to stay bright in future. As such, there is tremendous pressure to stay competitive in the market by optimizing products to next level of performance and reliability with the shortest time to market. This changes the conventional way of product design and development to virtual prototyping by means of Computer Aided Engineering (CAE). It comprises of the deployment of Finite Element Method (FEM) and Computational Fluid Dynamic (CFD). FEM accelerates the investigation for early detection of failures such as crack, improve the thermal performance of system and enhance solder joint reliability. CFD helps to simulate the flow pattern of molding material as a function of different temperature, molding parameters settings to evaluate failures like voids and displacement. This paper will briefly discuss the procedures and applications of FEM in thermal stress, solder joint reliability and CFD of compression molding in LED CSP. Integration of virtual prototyping in product development had greatly reduced the time to market. Many successful achievements with minimized number of evaluation iterations required in the scope of material, process setting, and package architecture variant have been materialized with this approach.

Keywords: LED, chip scale packaging (CSP), computational fluid dynamic (CFD), virtual prototyping

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1327 Hard Sludge Formation and Consolidation in Pressurized Water Reactor Steam Generators: An Experimental Study

Authors: R. Fernandez-Saavedra, M. B. Gomez-Mancebo, D. Gomez-Briceno

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The gradual corrosion of PWR (Pressurized Water Reactor) feedwater, condensate and drain systems results in the inevitable liberation of corrosion products, principally metallic oxides, to the secondary circuit. In addition, other contaminants and impurities are introduced into the makeup water, auxiliary feedwater and by condenser leaks. All these compounds circulating in the secondary flow can eventually be transported to steam generators and be transformed into deposits on their surfaces. Deposits that accumulate on the tube sheet are known as sludge piles and when they consolidate and harden become into hard sludge. Hard sludge is especially detrimental because it favors tube deformation or denting at the top of tube sheet and further stress corrosion cracking (SCC). These failures affect the efficiency of nuclear power plants. In a recent work, a model for the formation and consolidation of hard sludge has been formulated, highlighting the influence of aluminum and silicon compounds in the initial formation of hard sludge. In this work, an experimental study has been performed in order to get a deeper understanding of the behavior of Al and Si species in hard sludge formation and consolidation. For this purpose, the key components of hard sludge (magnetite, aluminum and/or silicon sources) have been isothermally autoclaved in representative secondary circuit conditions during one week, and the resulting products have been chemically and structurally characterized by XRF and XRD techniques, respectively.

Keywords: consolidation, hard sludge, secondary circuit, steam generator

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1326 Nonlinear Response of Tall Reinforced Concrete Shear Wall Buildings under Wind Loads

Authors: Mahtab Abdollahi Sarvi, Siamak Epackachi, Ali Imanpour

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Reinforced concrete shear walls are commonly used as the lateral load-resisting system of mid- to high-rise office or residential buildings around the world. Design of such systems is often governed by wind rather than seismic effects, in particular in low-to-moderate seismic regions. The current design philosophy as per the majority of building codes under wind loads require elastic response of lateral load-resisting systems including reinforced concrete shear walls when subjected to the rare design wind load, resulting in significantly large wall sections needed to meet strength requirements and drift limits. The latter can highly influence the design in upper stories due to stringent drift limits specified by building codes, leading to substantial added costs to the construction of the wall. However, such walls may offer limited to moderate over-strength and ductility due to their large reserve capacity provided that they are designed and detailed to appropriately develop such over-strength and ductility under extreme wind loads. This would significantly contribute to reducing construction time and costs, while maintaining structural integrity under gravity and frequently-occurring and less frequent wind events. This paper aims to investigate the over-strength and ductility capacity of several imaginary office buildings located in Edmonton, Canada with a glance at earthquake design philosophy. Selected models are 10- to 25-story buildings with three types of reinforced concrete shear wall configurations including rectangular, barbell, and flanged. The buildings are designed according to National Building Code of Canada. Then fiber-based numerical models of the walls are developed in Perform 3D and by conducting nonlinear static (pushover) analysis, lateral nonlinear behavior of the walls are evaluated. Ductility and over-strength of the structures are obtained based on the results of the pushover analyses. The results confirmed moderate nonlinear capacity of reinforced concrete shear walls under extreme wind loads. This is while lateral displacements of the walls pass the serviceability limit states defined in Pre standard for Performance-Based Wind Design (ASCE). The results indicate that we can benefit the limited nonlinear response observed in the reinforced concrete shear walls to economize the design of such systems under wind loads.

Keywords: concrete shear wall, high-rise buildings, nonlinear static analysis, response modification factor, wind load

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1325 A Biomimetic Structural Form: Developing a Paradigm to Attain Vital Sustainability in Tall Architecture

Authors: Osama Al-Sehail

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This paper argues for sustainability as a necessity in the evolution of tall architecture. It provides a different mode for dealing with sustainability in tall architecture, taking into consideration the speciality of its typology. To this end, the article develops a Biomimetic Structural Form as a paradigm to attain Vital Sustainability. A Biomimetic Structural Form, which is derived from the amalgamation of biomimicry as an approach for sustainability defining nature as source of knowledge and inspiration in solving humans’ problems and a Structural Form as a catalyst for evolving tall architecture, is a dynamic paradigm emerging from a conceptualizing and morphological process. A Biomimetic Structural Form is a flow system whose different forces and functions tend to be “better”, more "fit", to “survive”, and to be efficient. Through geometry and function—the two aspects of knowledge extracted from nature—the attributes of the Biomimetic Structural Form are formulated. Vital Sustainability is the survival level of sustainability in natural systems through which a system enhances the performance of its internal working and its interaction with the external environment. A Biomimetic Structural Form, in this context, is a medium for evolving tall architecture to emulate natural models in their ways of coexistence with the environment. As an integral part of this article, the sustainable super tall building 3Ts is discussed as a case study of applying Biomimetic Structural Form.   

Keywords: biomimicry, design in nature, high-rise buildings, sustainability, structural form, tall architecture, vital sustainability

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1324 Estimation of the Dynamic Fragility of Padre Jacinto Zamora Bridge Due to Traffic Loads

Authors: Kimuel Suyat, Francis Aldrine Uy, John Paul Carreon

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The Philippines, composed of many islands, is connected with approximately 8030 bridges. Continuous evaluation of the structural condition of these bridges is needed to safeguard the safety of the general public. With most bridges reaching its design life, retrofitting and replacement may be needed. Concerned government agencies allocate huge costs for periodic monitoring and maintenance of these structures. The rising volume of traffic and aging of these infrastructures is challenging structural engineers to give rise for structural health monitoring techniques. Numerous techniques are already proposed and some are now being employed in other countries. Vibration Analysis is one way. The natural frequency and vibration of a bridge are design criteria in ensuring the stability, safety and economy of the structure. Its natural frequency must not be so high so as not to cause discomfort and not so low that the structure is so stiff causing it to be both costly and heavy. It is well known that the stiffer the member is, the more load it attracts. The frequency must not also match the vibration caused by the traffic loads. If this happens, a resonance occurs. Vibration that matches a systems frequency will generate excitation and when this exceeds the member’s limit, a structural failure will happen. This study presents a method for calculating dynamic fragility through the use of vibration-based monitoring system. Dynamic fragility is the probability that a structural system exceeds a limit state when subjected to dynamic loads. The bridge is modeled in SAP2000 based from the available construction drawings provided by the Department of Public Works and Highways. It was verified and adjusted based from the actual condition of the bridge. The bridge design specifications are also checked using nondestructive tests. The approach used in this method properly accounts the uncertainty of observed values and code-based structural assumptions. The vibration response of the structure due to actual loads is monitored using installed sensors on the bridge. From the determinacy of these dynamic characteristic of a system, threshold criteria can be established and fragility curves can be estimated. This study conducted in relation with the research project between Department of Science and Technology, Mapúa Institute of Technology, and the Department of Public Works and Highways also known as Mapúa-DOST Smart Bridge Project deploys Structural Health Monitoring Sensors at Zamora Bridge. The bridge is selected in coordination with the Department of Public Works and Highways. The structural plans for the bridge are also readily available.

Keywords: structural health monitoring, dynamic characteristic, threshold criteria, traffic loads

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1323 Understanding Integrated Removal of Heavy Metals, Organic Matter and Nitrogen in a Constructed Wetland System Receiving Simulated Landfill Leachate

Authors: A. Mohammed, A. Babatunde

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This study investigated the integrated removal of heavy metals, organic matter and nitrogen from landfill leachate using a novel laboratory scale constructed wetland system. The main objectives of this study were: (i) to assess the overall effectiveness of the constructed wetland system for treating landfill leachate; (ii) to examine the interactions and impact of key leachate constituents (heavy metals, organic matter and nitrogen) on the overall removal dynamics and efficiency. The constructed wetland system consisted of four stages operated in tidal flow and anoxic conditions. Results obtained from 215 days of operation have demonstrated extraordinary heavy metals removal up to 100%. Analysis of the physico- chemical data reveal that the controlling factors for metals removal were the anoxic condition and the use of the novel media (dewatered ferric sludge which is a by-product of drinking water treatment process) as the main substrate in the constructed wetland system. Results show that the use of the ferric sludge enhanced heavy metals removal and brought more flexibility to simultaneous nitrification and denitrification which occurs within the microbial flocs. Furthermore, COD and NH4-N were effectively removed in the system and this coincided with enhanced aeration in the 2nd and 3rd stages of the constructed wetland system. Overall, the results demonstrated that the ferric dewatered sludge constructed wetland system would be an effective solution for integrated removal of pollutants from landfill leachates.

Keywords: constructed wetland, ferric dewatered sludge, heavy metals, landfill leachate

Procedia PDF Downloads 244
1322 Electrokinetic Regulation of Flow in Microcrack Reservoirs

Authors: Aslanova Aida Ramiz

Abstract:

One of the important aspects of rheophysical problems in oil and gas extraction is the regulation of thermohydrodynamic properties of liquid systems using physical and physicochemical methods. It is known that the constituent parts of real fluid systems in oil and gas production are practically non-conducting, non-magnetically active components. Real heterogeneous hydrocarbon systems, from the structural point of view, consist of an infinite number of microscopic local ion-electrostatic cores distributed in the volume of the dispersion medium. According to Cohen's rule, double electric layers are formed at the contact boundaries of components in contact (oil-gas, oil-water, water-condensate, etc.) in a heterogeneous system, and as a result, each real fluid system can be represented as a complex composition of a set of local electrostatic fields. The electrokinetic properties of this structure are characterized by a certain electrode potential. Prof. F.H. Valiyev called this potential the α-factor and came up with the idea that many natural and technological rheophysical processes (effects) are essentially electrokinetic in nature, and by changing the α-factor, it is possible to adjust the physical properties of real hydraulic systems, including thermohydrodynamic parameters. Based on this idea, extensive research work was conducted, and the possibility of reducing hydraulic resistances and improving rheological properties was experimentally discovered in real liquid systems by reducing the electrical potential with various physical and chemical methods.

Keywords: microcracked, electrode potential, hydraulic resistance, Newtonian fluid, rheophysical properties

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1321 Effect of Molybdenum Addition to Aluminum Grain Refined by Titanium Plus Boron on Its Grain Size and Mechanical Characteristics in the Cast and After Pressing by the Equal Channel Angular Pressing Conditions

Authors: A. I. O. Zaid, A. M. Attieh, S. M. A. Al Qawabah

Abstract:

Aluminum and its alloys solidify in columnar structure with large grain size which tends to reduce their mechanical strength and surface quality. They are, therefore, grain refined by addition of either titanium or titanium plus boron to their melt before solidification. Equal channel angular pressing, ECAP, process is a recent forming method for producing heavy plastic deformation in materials. In this paper, the effect of molybdenum addition to aluminum grain refined by Ti+B on its metallurgical and mechanical characteristics are investigated in the as cast condition and after pressing by the ECAP process. It was found that addition of Mo or Ti+B alone or together to aluminum resulted in grain refining of its microstructure in the as cast condition, as the average grain size was reduced from 139 micron to 46 micron when Mo and Ti+B are added together. Pressing by the ECAP process resulted in further refinement of the microstructure where 32 micron of average grain size was achieved in Al and the Al-Mo microalloy. Regarding the mechanical strength, addition of Mo or Ti+B alone to Al resulted in deterioration of its mechanical behavior but resulted in enhancement of its mechanical behavior when added together, increase of 10% in flow stress was achieved at 20% strain. However, pressing by ECAP addition of Mo or Ti+B alone to Al resulted in enhancement of its mechanical strength but reduced its strength when added together.

Keywords: ECAP, aluminum, cast, mechanical characteristics, Mo grain refiner

Procedia PDF Downloads 461
1320 The Two Question Challenge: Embedding the Serious Illness Conversation in Acute Care Workflows

Authors: D. M. Lewis, L. Frisby, U. Stead

Abstract:

Objective: Many patients are receiving invasive treatments in acute care or are dying in hospital without having had comprehensive goals of care conversations. Some of these treatments may not align with the patient’s wishes, may be futile, and may cause unnecessary suffering. While many staff may recognize the benefits of engaging patients and families in Serious Illness Conversations (a goal of care framework developed by Ariadne Labs in Boston), few staff feel confident and/or competent in having these conversations in acute care. Another barrier to having these conversations may be due to a lack of incorporation in the current workflow. An educational exercise, titled the Two Question Challenge, was initiated on four medical units across two Vancouver Coastal Health (VCH) hospitals in attempt to engage the entire interdisciplinary team in asking patients and families questions around goals of care and to improve the documentation of these expressed wishes and preferences. Methods: Four acute care units across two separate hospitals participated in the Two Question Challenge. On each unit, over the course of two eight-hour shifts, all members of the interdisciplinary team were asked to select at least two questions from a selection of nine goals of care questions. They were asked to pose these questions of a patient or family member throughout their shift and then asked to document their conversations in a centralized Advance Care Planning/Goals of Care discussion record in the patient’s chart. A visual representation of conversation outcomes was created to demonstrate to staff and patients the breadth of conversations that took place throughout the challenge. Staff and patients were interviewed about their experiences throughout the challenge. Two palliative approach leads remained present on the units throughout the challenge to support, guide, or role model these conversations. Results: Across four acute care medical units, 47 interdisciplinary staff participated in the Two Question Challenge, including nursing, allied health, and a physician. A total of 88 questions were asked of patients, or their families around goals of care and 50 newly documented goals of care conversations were charted. Two code statuses were changed as a result of the conversations. Patients voiced an appreciation for these conversations and staff were able to successfully incorporate these questions into their daily care. Conclusion: The Two Question Challenge proved to be an effective way of having teams explore the goals of care of patients and families in an acute care setting. Staff felt that they gained confidence and competence. Both staff and patients found these conversations to be meaningful and impactful and felt they were notably different from their usual interactions. Documentation of these conversations in a centralized location that is easily accessible to all care providers increased significantly. Application of the Two Question Challenge in non-medical units or other care settings, such as long-term care facilities or community health units, should be explored in the future.

Keywords: advance care planning, goals of care, interdisciplinary, palliative approach, serious illness conversations

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1319 Ecofriendly Synthesis of Au-Ag@AgCl Nanocomposites and Their Catalytic Activity on Multicomponent Domino Annulation-Aromatization for Quinoline Synthesis

Authors: Kanti Sapkota, Do Hyun Lee, Sung Soo Han

Abstract:

Nanocomposites have been widely used in various fields such as electronics, catalysis, and in chemical, biological, biomedical and optical fields. They display broad biomedical properties like antidiabetic, anticancer, antioxidant, antimicrobial and antibacterial activities. Moreover, nanomaterials have been used for wastewater treatment. Particularly, bimetallic hybrid nanocomposites exhibit unique features as compared to their monometallic components. Hybrid nanomaterials not only afford the multifunctionality endowed by their constituents but can also show synergistic properties. In addition, these hybrid nanomaterials have noteworthy catalytic and optical properties. Notably, Au−Ag based nanoparticles can be employed in sensor and catalysis due to their characteristic composition-tunable plasmonic properties. Due to their importance and usefulness, various efforts were developed for their preparation. Generally, chemical methods have been described to synthesize such bimetallic nanocomposites. In such chemical synthesis, harmful and hazardous chemicals cause environmental contamination and increase toxicity levels. Therefore, ecologically benevolent processes for the synthesis of nanomaterials are highly desirable to diminish such environmental and safety concerns. In this regard, here we disclose a simple, cost-effective, external additive free and eco-friendly method for the synthesis of Au-Ag@AgCl nanocomposites using Nephrolepis cordifolia root extract. Au-Ag@AgCl NCs were obtained by the simultaneous reduction of cationic Ag and Au into AgCl in the presence of plant extract. The particle size of 10 to 50 nm was observed with the average diameter of 30 nm. The synthesized nanocomposite was characterized by various modern characterization techniques. For example, UV−visible spectroscopy was used to determine the optical activity of the synthesized NCs, and Fourier transform infrared (FT-IR) spectroscopy was employed to investigate the functional groups present in the biomolecules that were responsible for both reducing and capping agents during the formation of nanocomposites. Similarly, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and energy-dispersive X-ray (EDX) spectroscopy were used to determine crystallinity, size, oxidation states, thermal stability and weight loss of the synthesized nanocomposites. As a synthetic application, the synthesized nanocomposite exhibited excellent catalytic activity for the multicomponent synthesis of biologically interesting quinoline molecules via domino annulation-aromatization reaction of aniline, arylaldehyde, and phenyl acetylene derivatives. Interestingly, the nanocatalyst was efficiently recycled for five times without substantial loss of catalytic properties.

Keywords: nanoparticles, catalysis, multicomponent, quinoline

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1318 Comparing the Effectiveness of the Crushing and Grinding Route of Comminution to That of the Mine to Mill Route in Terms of the Percentage of Middlings Present in Processed Lead-Zinc Ore Samples

Authors: Chinedu F. Anochie

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The presence of gangue particles in recovered metal concentrates has been a serious challenge to ore dressing engineers. Middlings lower the quality of concentrates, and in most cases, drastically affect the smelter terms, owing to exorbitant amounts paid by Mineral Processing industries as treatment charge. Models which encourage optimization of liberation operations have been utilized in most ore beneficiation industries to reduce the presence of locked particles in valuable concentrates. Moreover, methods such as incorporation of regrind mills, scavenger, rougher and cleaner cells, to the milling and flotation plants has been widely employed to tackle these concerns, and to optimize the grade–recovery relationship of metal concentrates. This work compared the crushing and grinding method of liberation, to the mine to mill route, by evaluating the proportion of middlings present in selectively processed complex Pb-Zn ore samples. To establish the effect of size reduction operations on the percentage of locked particles present in recovered concentrates, two similar samples of complex Pb- Zn ores were processed. Following blasting operation, the first ore sample was ground directly in a ball mill (Mine to Mill Route of Comminution), while the other sample was manually crushed, and subsequently ground in the ball mill (Crushing and Grinding Route of Comminution). The two samples were separately sieved in a mesh to obtain the desired representative particle sizes. An equal amount of each sample that would be processed in the flotation circuit was then obtained with the aid of a weighing balance. These weighed fine particles were simultaneously processed in the flotation circuit using the selective flotation technique. Sodium cyanide, Methyl isobutyl carbinol, Sodium ethyl xanthate, Copper sulphate, Sodium hydroxide, Lime and Isopropyl xanthate, were the reagents used to effect differential flotation of the two ore samples. Analysis and calculations showed that the degree of liberation obtained for the ore sample which went through the conventional crushing and grinding route of comminution, was higher than that of the directly milled run off mine (ROM) ore. Similarly, the proportion of middlings obtained from the separated galena (PbS) and sphalerite (ZnS) concentrates, were lower for the crushed and ground ore sample. A concise data which proved that the mine to mill method of size reduction is not the most ideal technique for the recovery of quality metal concentrates has been established.

Keywords: comminution, degree of liberation, middlings, mine to mill

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1317 Performance of BLDC Motor under Kalman Filter Sensorless Drive

Authors: Yuri Boiko, Ci Lin, Iluju Kiringa, Tet Yeap

Abstract:

The performance of a BLDC motor controlled by the Kalman filter-based position-sensorless drive is studied in terms of its dependence on the system’s parameters' variations. The effects of system’s parameters changes on the dynamic behavior of state variables are verified. Simulated is a closed-loop control scheme with a Kalman filter in the feedback line. Distinguished are two separate data sampling modes in analyzing feedback output from the BLDC motor: (1) equal angular separation and (2) equal time intervals. In case (1), the data are collected via equal intervals Δθ of rotor’s angular position θᵢ, i.e., keeping Δθ=const. In case (2), the data collection time points tᵢ are separated by equal sampling time intervals Δt=const. Demonstrated are the effects of the parameters changes on the sensorless control flow, in particular, reduction of the torque ripples, switching spikes, torque load balancing. It is specifically shown that an efficient suppression of commutation induced torque ripples is achievable selection of the sampling rate in the Kalman filter settings above certain critical value. The computational cost of such suppression is shown to be higher for the motors with lower induction values of the windings.

Keywords: BLDC motor, Kalman filter, sensorless drive, state variables, torque ripples reduction, sampling rate

Procedia PDF Downloads 139
1316 Alumina Supported Copper-Manganese Catalysts for Combustion of Exhaust Gases: Effect of Preparation Method

Authors: Krasimir Ivanov, Elitsa Kolentsova, Dimitar Dimitrov

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The development of active and stable catalysts without noble metals for low temperature oxidation of exhaust gases remains a significant challenge. The purpose of this study is to determine the influence of the preparation method on the catalytic activity of the supported copper-manganese mixed oxides in terms of VOCs oxidation. The catalysts were prepared by impregnation of γ-Al2O3 with copper and manganese nitrates and acetates and the possibilities for CO, CH3OH and dimethyl ether (DME) oxidation were evaluated using continuous flow equipment with a four-channel isothermal stainless steel reactor. Effect of the support, Cu/Mn mole ratio, heat treatment of the precursor and active component loading were investigated. Highly active alumina supported Cu-Mn catalysts for CO and VOCs oxidation were synthesized. The effect of preparation conditions on the activity behavior of the catalysts was discussed. The synergetic interaction between copper and manganese species increases the activity for complete oxidation over mixed catalysts. Type of support, calcination temperature and active component loading along with catalyst composition are important factors, determining catalytic activity. Cu/Mn molar ratio of 1:5, heat treatment at 450oC and 20 % active component loading are the best compromise for production of active catalyst for simultaneous combustion of CO, CH3OH and DME.

Keywords: copper-manganese catalysts, CO, VOCs oxidation, exhaust gases

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1315 Enhancement Production and Development of Hot Dry Rock System by Using Supercritical CO2 as Working Fluid Instead of Water to Advance Indonesia's Geothermal Energy

Authors: Dhara Adhnandya Kumara, Novrizal Novrizal

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Hot Dry Rock (HDR) is one of geothermal energy which is abundant in many provinces in Indonesia. Heat exploitation from HDR would need a method which injects fluid to subsurface to crack the rock and sweep the heat. Water is commonly used as the working fluid but known to be less effective in some ways. The new research found out that Supercritical CO2 (SCCO2) can be used to replace water as the working fluid. By studying heat transfer efficiency, pumping power, and characteristics of the returning fluid, we might decide how effective SCCO2 to replace water as working fluid. The method used to study those parameters quantitatively could be obtained from pre-existing researches which observe the returning fluids from the same reservoir with same pumping power. The result shows that SCCO2 works better than water. For cold and hot SCCO2 has lower density difference than water, this results in higher buoyancy in the system that allows the fluid to circulate with lower pumping power. Besides, lower viscosity of SCCO2 impacts in higher flow rate in circulation. The interaction between SCCO2 and minerals in reservoir could induce dehydration of the minerals and enhancement of rock porosity and permeability. While the dissolution and transportation of minerals by SCCO2 are unlikely to occur because of the nature of SCCO2 as poor solvent, and this will reduce the mineral scaling in the system. Under those conditions, using SCCO2 as working fluid for HDR extraction would give great advantages to advance geothermal energy in Indonesia.

Keywords: geothermal, supercritical CO2, injection fluid, hot dry rock

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1314 Improved Thermal Comfort in Cabin Aircraft with in-Seat Microclimate Conditioning Module

Authors: Mathieu Le Cam, Tejaswinee Darure, Mateusz Pawlucki

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Climate control of cabin aircraft is traditionally conditioned as a single unit by the environmental control system. Cabin temperature is controlled by the crew while passengers of the aircraft have control on the gaspers providing fresh air from the above head area. The small nozzles are difficult to reach and adjust to meet the passenger’s needs in terms of flow and direction. More dedicated control over the near environment of each passenger can be beneficial in many situations. The European project COCOON, funded under Clean Sky 2, aims at developing and demonstrating a microclimate conditioning module (MCM) integrated into a standard economy 3-seat row. The system developed will lead to improved passenger comfort with more control on their personal thermal area. This study focuses on the assessment of thermal comfort of passengers in the cabin aircraft through simulation on the TAITherm modelling platform. A first analysis investigates thermal comfort and sensation of passengers in varying cabin environmental conditions: from cold to very hot scenarios, with and without MCM installed in the seats. The modelling platform is also used to evaluate the impact of different physiologies of passengers on their thermal comfort as well as different seat locations. Under the current cabin conditions, a passenger of a 50th percentile body size is feeling uncomfortably cool due to the high velocity cabin air ventilation. The simulation shows that the in-seat MCM developed in COCOON project improves the thermal comfort of the passenger.

Keywords: cabin aircraft, in-seat HVAC, microclimate conditioning module, thermal comfort

Procedia PDF Downloads 183
1313 Disclosure on Adherence of the King Code's Audit Committee Guidance: Cluster Analyses to Determine Strengths and Weaknesses

Authors: Philna Coetzee, Clara Msiza

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In modern society, audit committees are seen as the custodians of accountability and the conscience of management and the board. But who holds the audit committee accountable for their actions or non-actions and how do we know what they are supposed to be doing and what they are doing? The purpose of this article is to provide greater insight into the latter part of this problem, namely, determine what best practises for audit committees and the disclosure of what is the realities are. In countries where governance is well established, the roles and responsibilities of the audit committee are mostly clearly guided by legislation and/or guidance documents, with countries increasingly providing guidance on this topic. With high cost involved to adhere to governance guidelines, the public (for public organisations) and shareholders (for private organisations) expect to see the value of their ‘investment’. For audit committees, the dividends on the investment should reflect in less fraudulent activities, less corruption, higher efficiency and effectiveness, improved social and environmental impact, and increased profits, to name a few. If this is not the case (which is reflected in the number of fraudulent activities in both the private and the public sector), stakeholders have the right to ask: where was the audit committee? Therefore, the objective of this article is to contribute to the body of knowledge by comparing the adherence of audit committee to best practices guidelines as stipulated in the King Report across public listed companies, national and provincial government departments, state-owned enterprises and local municipalities. After constructs were formed, based on the literature, factor analyses were conducted to reduce the number of variables in each construct. Thereafter, cluster analyses, which is an explorative analysis technique that classifies a set of objects in such a way that objects that are more similar are grouped into the same group, were conducted. The SPSS TwoStep Clustering Component was used, being capable of handling both continuous and categorical variables. In the first step, a pre-clustering procedure clusters the objects into small sub-clusters, after which it clusters these sub-clusters into the desired number of clusters. The cluster analyses were conducted for each construct and the measure, namely the audit opinion as listed in the external audit report, were included. Analysing 228 organisations' information, the results indicate that there is a clear distinction between the four spheres of business that has been included in the analyses, indicating certain strengths and certain weaknesses within each sphere. The results may provide the overseers of audit committees’ insight into where a specific sector’s strengths and weaknesses lie. Audit committee chairs will be able to improve the areas where their audit committee is lacking behind. The strengthening of audit committees should result in an improvement of the accountability of boards, leading to less fraud and corruption.

Keywords: audit committee disclosure, cluster analyses, governance best practices, strengths and weaknesses

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1312 The Recognition of Exclusive Choice of Court Agreements: United Arab Emirates Perspective and the 2005 Hague Convention on Choice of Court Agreements

Authors: Hasan Alrashid

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The 2005 Hague Convention seeks to ensure legal certainty and predictability between parties in international business transactions. It harmonies exclusive choice of court agreements at the international level between parties to commercial transactions and to govern the recognition and enforcement of judgments resulting from proceedings based on such agreements to promote international trade and investment. Although the choice of court agreements is significant in international business transactions, the United Arab Emirates refuse to recognise it by Article 24 of the Federal Law No. 11 of 1992 of the Civil Procedure Code. A review of judicial judgments in United Arab Emirates up to the present day has revealed that several cases appeared before the Court in different states of United Arab Emirates regarding the recognition of exclusive choice of court agreements. In all the cases, the courts regarded the exclusive choice of court agreements as a direct assault on state authority and sovereignty and refused categorically to recognize choice of court agreements by refusing to stay proceedings in favor of the foreign chosen court. This has created uncertainty and unpredictability in international business transaction in the United Arab Emirates. In June 2011, the first Gulf Judicial Seminar on Cross-Frontier Legal Cooperation in Civil and Commercial Matters was held in Doha, Qatar. The Permanent Bureau of the Hague Conference attended the conference and invited the states of the Gulf Cooperation Council (GCC) namely, The United Arab Emirates, Bahrain, Saudi Arabia, Oman, Qatar and Kuwait to adopt some of the Hague Conventions, one of which was the Hague Convention on Choice of Court Agreements. One of the recommendations of the conference was that the GCC states should research ‘the benefits of predictability and legal certainty provided by the 2005 Convention on Choice of Court Agreements and its resulting advantages for cross-border trade and investment’ for possible adoption of the Hague Convention. Up to today, no further step has been taken by the any of the GCC states to adapt the Hague Convention nor did they conduct research on the benefits of predictability and legal certainty in international business transactions. This paper will argue that the approach regarding the recognition of choice of court agreements in United Arab Emirates states can be improved in order to help the parties in international business transactions avoid parallel litigation and ensure legal certainty and predictability. The focus will be the uncertainty and gaps regarding the choice of court agreements in the United Arab Emirates states. The Hague Convention on choice of court agreements and the importance of harmonisation of the rules of choice of court agreements at international level will also be discussed. Finally, The feasibility and desirability of recognizing choice of court agreements in United Arab Emirates legal system by becoming a party to the Hague Convention will be evaluated.

Keywords: choice of court agreements, party autonomy, public authority, sovereignty

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1311 Supply Chain Technology Adoption in Textile and Apparel Industry

Authors: Zulkifli Mohamed Udin, Lee Khai-Loon, Mohamad Ghozali Hassan

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In today’s dynamic business environment, the competition is no longer between firms, but between supply chains to gain competitive advantages. The global manufacturing sector, especially the textile and apparel industry are essentially known for its supply chain dependency. The delicate nature of its business leads to emphasis on the smooth movement of upstream and downstream supply chain. The nature of this industry, however, result in huge dynamic flow of physical, information, and financial. The dynamic management of these flows requires adoption of supply chain technologies. Even though technology is widely implemented and studied in many industries by researchers, adoption of supply chain technologies in Malaysian textile and apparel industry is limited. There is relatively a handful academic study conducted on recent developments in Malaysian textile and apparel industry and supply chain technology adoption indicate a major gap in supply chain performance studies. Considering the importance given to Third Industrial Master Plan by the government Malaysia, it is necessary to understand the power of supply chain technology adoptions. This study aims to investigate supply chain technology adoption by textile and apparel companies in Malaysia. The result highlighted the benefits perceived by textile and apparel companies from supply chain technologies. The indifference of small and medium enterprises to operation management acts as a major inhibitor to the adoption of supply chain technologies, since they have resource limitations. This study could be used as a precursor for further detailed studies on this issue.

Keywords: supply chain technology adoption, supply chain performance, textile, apparel industry

Procedia PDF Downloads 481