Search results for: efficiency analysis and selection bias
29506 Analytical and Numerical Modeling of Strongly Rotating Rarefied Gas Flows
Authors: S. Pradhan, V. Kumaran
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Centrifugal gas separation processes effect separation by utilizing the difference in the mole fraction in a high speed rotating cylinder caused by the difference in molecular mass, and consequently the centrifugal force density. These have been widely used in isotope separation because chemical separation methods cannot be used to separate isotopes of the same chemical species. More recently, centrifugal separation has also been explored for the separation of gases such as carbon dioxide and methane. The efficiency of separation is critically dependent on the secondary flow generated due to temperature gradients at the cylinder wall or due to inserts, and it is important to formulate accurate models for this secondary flow. The widely used Onsager model for secondary flow is restricted to very long cylinders where the length is large compared to the diameter, the limit of high stratification parameter, where the gas is restricted to a thin layer near the wall of the cylinder, and it assumes that there is no mass difference in the two species while calculating the secondary flow. There are two objectives of the present analysis of the rarefied gas flow in a rotating cylinder. The first is to remove the restriction of high stratification parameter, and to generalize the solutions to low rotation speeds where the stratification parameter may be O (1), and to apply for dissimilar gases considering the difference in molecular mass of the two species. Secondly, we would like to compare the predictions with molecular simulations based on the direct simulation Monte Carlo (DSMC) method for rarefied gas flows, in order to quantify the errors resulting from the approximations at different aspect ratios, Reynolds number and stratification parameter. In this study, we have obtained analytical and numerical solutions for the secondary flows generated at the cylinder curved surface and at the end-caps due to linear wall temperature gradient and external gas inflow/outflow at the axis of the cylinder. The effect of sources of mass, momentum and energy within the flow domain are also analyzed. The results of the analytical solutions are compared with the results of DSMC simulations for three types of forcing, a wall temperature gradient, inflow/outflow of gas along the axis, and mass/momentum input due to inserts within the flow. The comparison reveals that the boundary conditions in the simulations and analysis have to be matched with care. The commonly used diffuse reflection boundary conditions at solid walls in DSMC simulations result in a non-zero slip velocity as well as a temperature slip (gas temperature at the wall is different from wall temperature). These have to be incorporated in the analysis in order to make quantitative predictions. In the case of mass/momentum/energy sources within the flow, it is necessary to ensure that the homogeneous boundary conditions are accurately satisfied in the simulations. When these precautions are taken, there is excellent agreement between analysis and simulations, to within 10 %, even when the stratification parameter is as low as 0.707, the Reynolds number is as low as 100 and the aspect ratio (length/diameter) of the cylinder is as low as 2, and the secondary flow velocity is as high as 0.2 times the maximum base flow velocity.Keywords: rotating flows, generalized onsager and carrier-Maslen model, DSMC simulations, rarefied gas flow
Procedia PDF Downloads 40329505 Analyzing the Perceptions of Emotions in Aesthetic Music
Authors: Abigail Wiafe, Charles Nutrokpor, Adelaide Oduro-Asante
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The advancement of technology is rapidly making people more receptive to music as computer-generated music requires minimal human interventions. Though algorithms are applied to generate music, the human experience of emotions is still explored. Thus, this study investigates the emotions humans experience listening to computer-generated music that possesses aesthetic qualities. Forty-two subjects participated in the survey. The selection process was purely arbitrary since it was based on convenience. Subjects listened and evaluated the emotions experienced from the computer-generated music through an online questionnaire. The Likert scale was used to rate the emotional levels after the music listening experience. The findings suggest that computer-generated music possesses aesthetic qualities that do not affect subjects' emotions as long as they are pleased with the music. Furthermore, computer-generated music has unique creativity, and expressioneven though the music produced is meaningless, the computational models developed are unable to present emotional contents in music as humans do.Keywords: aesthetic, algorithms, emotions, computer-generated music
Procedia PDF Downloads 14129504 Heat Forging Analysis Method on Blank Consist of Two Metals
Authors: Takashi Ueda, Shinichi Enoki
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Forging parts is used to automobiles. Because they have high strength and it is possible to press them into complicated shape. When it is possible to manufacture hollow forging parts, it leads to reduce weight of the automobiles. But, hollow forging parts are confined to axisymmetrical shape. Hollow forging parts that were pressed to complicated shape are expected. Therefore, we forge a blank that aluminum alloy was inserted in stainless steel. After that, we can provide complex forging parts that are reduced weight, if it is possible to be melted the aluminum alloy away by using different of melting points. It is necessary to establish heat forging analysis method on blank consist of stainless steel and aluminum alloy. Because, this forging is different from conventional forging and this technology is not confirmed. In this study, we compared forging experiment with numerical analysis on the view point of forming load and shape after forming and establish how to set the material temperatures of two metals and material property of stainless steel on the analysis method. Consequently, temperature difference of stainless steel and aluminum alloy was obtained by experiment. We got material property of stainless steel on forging experimental by compression tests. We had compared numerical analysis that was used the temperature difference of two metals and the material property of stainless steel on forging experimental with forging experiment. Forging analysis method on blank consist of two metals was established by result of numerical analysis having agreed with result of forging experiment.Keywords: forging, lightweight, analysis, hollow
Procedia PDF Downloads 41829503 Quantitative Ranking Evaluation of Wine Quality
Authors: A. Brunel, A. Kernevez, F. Leclere, J. Trenteseaux
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Today, wine quality is only evaluated by wine experts with their own different personal tastes, even if they may agree on some common features. So producers do not have any unbiased way to independently assess the quality of their products. A tool is here proposed to evaluate wine quality by an objective ranking based upon the variables entering wine elaboration, and analysed through principal component analysis (PCA) method. Actual climatic data are compared by measuring the relative distance between each considered wine, out of which the general ranking is performed.Keywords: wine, grape, weather conditions, rating, climate, principal component analysis, metric analysis
Procedia PDF Downloads 32229502 Bayesian Approach for Moving Extremes Ranked Set Sampling
Authors: Said Ali Al-Hadhrami, Amer Ibrahim Al-Omari
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In this paper, Bayesian estimation for the mean of exponential distribution is considered using Moving Extremes Ranked Set Sampling (MERSS). Three priors are used; Jeffery, conjugate and constant using MERSS and Simple Random Sampling (SRS). Some properties of the proposed estimators are investigated. It is found that the suggested estimators using MERSS are more efficient than its counterparts based on SRS.Keywords: Bayesian, efficiency, moving extreme ranked set sampling, ranked set sampling
Procedia PDF Downloads 51829501 Modeling and Simulation of Turbulence Induced in Nozzle Cavitation and Its Effects on Internal Flow in a High Torque Low Speed Diesel Engine
Authors: Ali Javaid, Rizwan Latif, Syed Adnan Qasim, Imran Shafi
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To control combustion inside a direct injection diesel engine, fuel atomization is the best tool. Controlling combustion helps in reducing emissions and improves efficiency. Cavitation is one of the most important factors that significantly affect the nature of spray before it injects into combustion chamber. Typical fuel injector nozzles are small and operate at a very high pressure, which limits the study of internal nozzle behavior especially in case of diesel engine. Simulating cavitation in a fuel injector will help in understanding the phenomenon and will assist in further development. There is a parametric variation between high speed and high torque low speed diesel engines. The objective of this study is to simulate internal spray characteristics for a low speed high torque diesel engine. In-nozzle cavitation has strong effects on the parameters e.g. mass flow rate, fuel velocity, and momentum flux of fuel that is to be injected into the combustion chamber. The external spray dynamics and subsequently the air – fuel mixing depends on a lot of the parameters of fuel injecting the nozzle. The approach used to model turbulence induced in – nozzle cavitation for high-torque low-speed diesel engine, is homogeneous equilibrium model. The governing equations were modeled using Matlab. Complete Model in question was extensively evaluated by performing 3-D time-dependent simulations on Open FOAM, which is an open source flow solver and implemented in CFD (Computational Fluid Dynamics). Results thus obtained will be analyzed for better evaporation in the near-nozzle region. The proposed analyses will further help in better engine efficiency, low emission, and improved fuel economy.Keywords: cavitation, HEM model, nozzle flow, open foam, turbulence
Procedia PDF Downloads 29329500 Characterization of Banana (Musa spp.) Pseudo-Stem and Fruit-Bunch-Stem as a Potential Renewable Energy Resource
Authors: Nurhayati Abdullah, Fauziah Sulaiman, Muhamad Azman Miskam, Rahmad Mohd Taib
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Banana pseudo-stem and fruit-bunch-stem are agricultural residues that can be used for conversion to bio-char, bio-oil, and gases by using thermochemical process. The aim of this work is to characterize banana pseudo-stem and banana fruit-bunch-stem through proximate analysis, elemental analysis, chemical analysis, thermo-gravimetric analysis, and heating calorific value. The ash contents of the banana pseudo-stem and banana fruit-bunch-stem are 11.0 mf wt.% and 20.6 mf wt.%; while the carbon content of banana pseudo-stem and fruit-bunch-stem are 37.9 mf wt.% and 35.58 mf wt.% respectively. The molecular formulas for banana stem and banana fruit-bunch-stem are C24H33NO26 and C19H29NO33 respectively. The measured higher heating values of banana pseudo-stem and banana fruit-bunch-stem are 15.5MJ/kg and 12.7 MJ/kg respectively. By chemical analysis, the lignin, cellulose, and hemicellulose contents in the samples will also be presented. The feasibility of the banana wastes to be a feedstock for thermochemical process in comparison with other biomass will be discussed in this paper.Keywords: banana waste, biomass, renewable energy, thermo-chemical characteristics
Procedia PDF Downloads 52429499 Assessment of Power Quality Impact of Photovoltaic Integration: A Case Study of a Government Building in Malaysia
Authors: Muhammad Nuqman Bin Anuar, Dalila Mat Said
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The integration of photovoltaic (PV) systems in government buildings represents a crucial step toward enhancing energy efficiency and promoting sustainability. However, the adoption of PV systems can introduce challenges in maintaining power quality due to the intermittent nature of solar generation. The effect of a self-consumption photovoltaic system on the power quality characteristics of a Malaysian government building is examined in this study. Total harmonic distortion of current (THDi), total harmonic distortion of voltage (THDv), voltage (Vrms), current (Irms), and power factors are among the important parameters that were examined both before and after the PV system was installed. Power quality data were collected over several weeks by using a power quality analyzer Fluke 1750, and a comparative analysis was conducted to evaluate changes in these parameters. The results show significant fluctuations in the power factor, particularly during periods of high solar generation, with notable variations in THDi across the three phases. These fluctuations highlight the potential interactions between solar generation and load demand, emphasizing the need for harmonic mitigation. Despite these issues, Vrms and THDv remained within acceptable limits, ensuring compliance with power quality standards. This study provides insights into the power quality behaviour of self-consumption PV systems before and after the installation of photovoltaics.Keywords: power quality, power factor, harmonics, photovoltaic
Procedia PDF Downloads 1429498 Probabilistic and Stochastic Analysis of a Retaining Wall for C-Φ Soil Backfill
Authors: André Luís Brasil Cavalcante, Juan Felix Rodriguez Rebolledo, Lucas Parreira de Faria Borges
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A methodology for the probabilistic analysis of active earth pressure on retaining wall for c-Φ soil backfill is described in this paper. The Rosenblueth point estimate method is used to measure the failure probability of a gravity retaining wall. The basic principle of this methodology is to use two point estimates, i.e., the standard deviation and the mean value, to examine a variable in the safety analysis. The simplicity of this framework assures to its wide application. For the calculation is required 2ⁿ repetitions during the analysis, since the system is governed by n variables. In this study, a probabilistic model based on the Rosenblueth approach for the computation of the overturning probability of failure of a retaining wall is presented. The obtained results have shown the advantages of this kind of models in comparison with the deterministic solution. In a relatively easy way, the uncertainty on the wall and fill parameters are taken into account, and some practical results can be obtained for the retaining structure design.Keywords: retaining wall, active earth pressure, backfill, probabilistic analysis
Procedia PDF Downloads 42129497 Optimization of a Cone Loudspeaker Parameter of Design Parameters by Analysis of a Narrow Acoustic Sound Pathway
Authors: Yue Hu, Xilu Zhao, Takao Yamaguchi, Manabu Sasajima, Yoshio Koike, Akira Hara
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This study tried optimization of design parameter of a cone loudspeaker unit as an example of the high flexibility of the products design. We developed an acoustic analysis software program that considers the impact of damping caused by air viscosity. In sound reproduction, it is difficult to each design the parameter of the loudspeaker. To overcome the limitation of the design problem in practice, this paper proposes a new an acoustic analysis algorithm to optimize design the parameter of the loudspeaker. The material character of cone paper and the loudspeaker edge was the design parameter, and the vibration displacement of the cone paper was the objective function. The results of the analysis were compared with the predicted value. They had high accuracy to the predicted value. These results suggest that, though the parameter design is difficult by experience and intuition, it can be performed comparatively easily using the optimization design by the developed acoustic analysis software.Keywords: air viscosity, loudspeaker, cone paper, edge, optimization
Procedia PDF Downloads 40529496 Econophysics: The Use of Entropy Measures in Finance
Authors: Muhammad Sheraz, Vasile Preda, Silvia Dedu
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Concepts of econophysics are usually used to solve problems related to uncertainty and nonlinear dynamics. In the theory of option pricing the risk neutral probabilities play very important role. The application of entropy in finance can be regarded as the extension of both information entropy and the probability entropy. It can be an important tool in various financial methods such as measure of risk, portfolio selection, option pricing and asset pricing. Gulko applied Entropy Pricing Theory (EPT) for pricing stock options and introduced an alternative framework of Black-Scholes model for pricing European stock option. In this article, we present solutions to maximum entropy problems based on Tsallis, Weighted-Tsallis, Kaniadakis, Weighted-Kaniadakies entropies, to obtain risk-neutral densities. We have also obtained the value of European call and put in this framework.Keywords: option pricing, Black-Scholes model, Tsallis entropy, Kaniadakis entropy, weighted entropy, risk-neutral density
Procedia PDF Downloads 31129495 Dynamic Response Analysis of Structure with Random Parameters
Authors: Ahmed Guerine, Ali El Hafidi, Bruno Martin, Philippe Leclaire
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In this paper, we propose a method for the dynamic response of multi-storey structures with uncertain-but-bounded parameters. The effectiveness of the proposed method is demonstrated by a numerical example of three-storey structures. This equation is integrated numerically using Newmark’s method. The numerical results are obtained by the proposed method. The simulation accounting the interval analysis method results are compared with a probabilistic approach results. The interval analysis method provides a mean curve that is between an upper and lower bound obtained from the probabilistic approach.Keywords: multi-storey structure, dynamic response, interval analysis method, random parameters
Procedia PDF Downloads 19529494 Sfard’s Commognitive Framework as a Method of Discourse Analysis in Mathematics
Authors: Dong-Joong Kim, Sangho Choi, Woong Lim
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This paper discusses Sfard’s commognitive approach and provides an empirical study as an example to illustrate the theory as method. Traditionally, research in mathematics education focused on the acquisition of mathematical knowledge and the didactic process of knowledge transfer. Through attending to a distinctive form of language in mathematics, as well as mathematics as a discursive subject, alternative views of making meaning in mathematics have emerged; these views are therefore “critical,” as in critical discourse analysis. The commognitive discourse analysis method has the potential to bring more clarity to our understanding of students’ mathematical thinking and the process through which students are socialized into school mathematics.Keywords: commognitive framework, discourse analysis, mathematical discourse, mathematics education
Procedia PDF Downloads 34029493 Analysis of the Impacts of Capital Goods' Import and Human Capital on the Economic Growth of the Sub Sahahra Africa: A Panel-ARDL Approach
Authors: Adeleke Omolade
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The study investigated the impacts of capital goods' import and human capital on the economic growth of the Sub Sahahra Africa (SSA). 30 countries were used in the Panel- ARDL analysis where economic growth is the dependent variables and capital goods' import, human capital, primary export, investment exchange rate, among others were used as the independent variables. The result from the panel analysis indicates that capital goods' import will significantly and positively influence economic growth but human capital fails to have significant positive impact on economic growth of the SSA. Earlier the trend analysis and the correlation results have shown that there is a weak association between capital goods' import and human capital in the SSA. The results offer an expository analysis that reveals that the quality of the human capital is very germane to the effective utilization of capital goods' import for the purpose of growth in a primary goods' export dominated region like the SSA.Keywords: capital goods import, economic growth, human capital, Sub-Sahara Africa
Procedia PDF Downloads 24129492 Risk Analysis in Road Transport of Dangerous Goods Using Complex Multi-Criteria Analysis Method
Authors: Zoran Masoničić, Siniša Dragutinović, Ivan Lazović
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In the management and organization of the road transport of dangerous goods, in addition to the existing influential criteria and restrictions that apply to the road transport in general, it is necessary to include an additional criteria related to the safety of people and the environment, considering the danger that comes from the substances being transported. In that manner, the decision making process becomes very complex and rather challenging task that is inherent to the application of complex numerical multi-criteria analysis methods. In this paper some initial results of application of complex analysis method in decision making process are presented. Additionally, the method for minimization or even complete elimination of subjective element in the decision making process is provided. The results obtained can be used in order to point the direction towards some measures have to be applied in order to minimize or completely annihilate the influence of the risk source identified.Keywords: road transport, dangerous goods, risk analysis, risk evaluation
Procedia PDF Downloads 2429491 Comparative Evaluation of High Pure Mn3O4 Preparation Technique between the Conventional Process from Electrolytic Manganese and a Sustainable Approach Directly from Low-Grade Rhodochrosite
Authors: Fang Lian, Zefang Chenli, Laijun Ma, Lei Mao
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Up to now, electrolytic process is a popular way to prepare Mn and MnO2 (EMD) with high purity. However, the conventional preparation process of manganese oxide such as Mn3O4 with high purity from electrolytic manganese metal is characterized by long production-cycle, high-pollution discharge and high energy consumption especially initially from low-grade rhodochrosite, the main resources for exploitation and applications in China. Moreover, Mn3O4 prepared from electrolytic manganese shows large particles, single morphology beyond the control and weak chemical activity. On the other hand, hydrometallurgical method combined with thermal decomposition, hydrothermal synthesis and sol-gel processes has been widely studied because of its high efficiency, low consumption and low cost. But the key problem in direct preparation of manganese oxide series from low-grade rhodochrosite is to remove completely the multiple impurities such as iron, silicon, calcium and magnesium. It is urgent to develop a sustainable approach to high pure manganese oxide series with character of short process, high efficiency, environmentally friendly and economical benefit. In our work, the preparation technique of high pure Mn3O4 directly from low-grade rhodochrosite ore (13.86%) was studied and improved intensively, including the effective leaching process and the short purifying process. Based on the same ion effect, the repeated leaching of rhodochrosite with sulfuric acid is proposed to improve the solubility of Mn2+ and inhibit the dissolution of the impurities Ca2+ and Mg2+. Moreover, the repeated leaching process could make full use of sulfuric acid and lower the cost of the raw material. With the aid of theoretical calculation, Ba(OH)2 was chosen to adjust the pH value of manganese sulfate solution and BaF2 to remove Ca2+ and Mg2+ completely in the process of purifying. Herein, the recovery ratio of manganese and removal ratio of the impurity were evaluated via chemical titration and ICP analysis, respectively. Comparison between conventional preparation technique from electrolytic manganese and a sustainable approach directly from low-grade rhodochrosite have also been done herein. The results demonstrate that the extraction ratio and the recovery ratio of manganese reached 94.3% and 92.7%, respectively. The heavy metal impurities has been decreased to less than 1ppm, and the content of calcium, magnesium and sodium has been decreased to less than 20ppm, which meet standards of high pure reagent for energy and electronic materials. In compare with conventional technique from electrolytic manganese, the power consumption has been reduced to ≤2000 kWh/t(product) in our short-process approach. Moreover, comprehensive recovery rate of manganese increases significantly, and the wastewater generated from our short-process approach contains low content of ammonia/ nitrogen about 500 mg/t(product) and no toxic emissions. Our study contributes to the sustainable application of low-grade manganese ore. Acknowledgements: The authors are grateful to the National Science and Technology Support Program of China (No.2015BAB01B02) for financial support to the work.Keywords: leaching, high purity, low-grade rhodochrosite, manganese oxide, purifying process, recovery ratio
Procedia PDF Downloads 25029490 A Study of Industrial Symbiosis and Implementation of Indigenous Circular Economy Technique on an Indian Industrial Area
Authors: A. Gokulram
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Industrial waste is often categorized as commercial and non-commercial waste by market value. In many Indian industries and other industrialized countries, the commercial value waste is capitalized and non-commercial waste is dumped to landfill. A lack of adequate research on industrial waste leads to the failure of effective resource management and the non-commercial waste are being considered as commercially non-viable residues. The term Industrial symbiosis refers to the direct inter-firm reuse or exchange of material and energy resource. The resource efficiency of commercial waste is mainly followed by an informal symbiosis in our research area. Some Industrial residues are reused within the facility where they are generated, others are reused directly nearby industrial facilities and some are recycled via the formal and informal market. The act of using industrial waste as a resource for another product faces challenges in India. This research study has observed a major negligence of trust and communication among several bodies to implement effective circular economy in India. This study applies interviewing process across researchers, government bodies, industrialist and designers to understand the challenges of circular economy in India. The study area encompasses an industrial estate in Ahmedabad in the state of Gujarat which comprises of 1200 industries. The research study primarily focuses on making industrial waste as commercial ready resource and implementing Indigenous sustainable practice in modern context to improve resource efficiency. This study attempted to initiate waste exchange platform among several industrialist and used varied methodologies from mail questionnaire to telephone survey. This study makes key suggestions to policy change and sustainable finance to improve circular economy in India.Keywords: effective resource management, environmental policy, indigenous technique, industrial symbiosis, sustainable finance
Procedia PDF Downloads 13929489 Generative Design Method for Cooled Additively Manufactured Gas Turbine Parts
Authors: Thomas Wimmer, Bernhard Weigand
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The improvement of gas turbine efficiency is one of the main drivers of research and development in the gas turbine market. This has led to elevated gas turbine inlet temperatures beyond the melting point of the utilized materials. The turbine parts need to be actively cooled in order to withstand these harsh environments. However, the usage of compressor air as coolant decreases the overall gas turbine efficiency. Thus, coolant consumption needs to be minimized in order to gain the maximum advantage from higher turbine inlet temperatures. Therefore, sophisticated cooling designs for gas turbine parts aim to minimize coolant mass flow. New design space is accessible as additive manufacturing is maturing to industrial usage for the creation of hot gas flow path parts. By making use of this technology more efficient cooling schemes can be manufacture. In order to find such cooling schemes a generative design method is being developed. It generates cooling schemes randomly which adhere to a set of rules. These assure the sanity of the design. A huge amount of different cooling schemes are generated and implemented in a simulation environment where it is validated. Criteria for the fitness of the cooling schemes are coolant mass flow, maximum temperature and temperature gradients. This way the whole design space is sampled and a Pareto optimum front can be identified. This approach is applied to a flat plate, which resembles a simplified section of a hot gas flow path part. Realistic boundary conditions are applied and thermal barrier coating is accounted for in the simulation environment. The resulting cooling schemes are presented and compared to representative conventional cooling schemes. Further development of this method can give access to cooling schemes with an even better performance having higher complexity, which makes use of the available design space.Keywords: additive manufacturing, cooling, gas turbine, heat transfer, heat transfer design, optimization
Procedia PDF Downloads 35429488 Predictors of Clinical Failure After Endoscopic Lumbar Spine Surgery During the Initial Learning Curve
Authors: Daniel Scherman, Daniel Madani, Shanu Gambhir, Marcus Ling Zhixing, Yingda Li
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Objective: This study aims to identify clinical factors that may predict failed endoscopic lumbar spine surgery to guide surgeons with patient selection during the initial learning curve. Methods: This is an Australasian prospective analysis of the first 105 patients to undergo lumbar endoscopic spine decompression by 3 surgeons. Modified MacNab outcomes, Oswestry Disability Index (ODI) and Visual Analogue Score (VAS) scores were utilized to evaluate clinical outcomes at 6 months postoperatively. Descriptive statistics and Anova t-tests were performed to measure statistically significant (p<0.05) associations between variables using GraphPad Prism v10. Results: Patients undergoing endoscopic lumbar surgery via an interlaminar or transforaminal approach have overall good/excellent modified MacNab outcomes and a significant reduction in post-operative VAS and ODI scores. Regardless of the anatomical location of disc herniations, good/excellent modified MacNab outcomes and significant reductions in VAS and ODI were reported post-operatively; however, not in patients with calcified disc herniations. Patients with central and foraminal stenosis overall reported poor/fair modified MacNab outcomes. However, there were significant reductions in VAS and ODI scores post-operatively. Patients with subarticular stenosis or an associated spondylolisthesis reported good/excellent modified MacNab outcomes and significant reductions in VAS and ODI scores post-operatively. Patients with disc herniation and concurrent degenerative stenosis had generally poor/fair modified MacNab outcomes. Conclusion: The outcomes of endoscopic spine surgery are encouraging, with a low complication and reoperation rate. However, patients with calcified disc herniations, central canal stenosis or a disc herniation with concurrent degenerative stenosis present challenges during the initial learning curve and may benefit from traditional open or other minimally invasive techniques.Keywords: complications, lumbar disc herniation, lumbar endoscopic spine surgery, predictors of failed endoscopic spine surgery
Procedia PDF Downloads 15929487 Evaluation of Inceptor Design for Manned Multicopter
Authors: Jędrzej Minda
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In aviation, a very narrow spectrum of control inceptors exists, namely centre sticks, side-sticks, pedals, and yokes. However, new types of aircraft are emerging, and with them, a need for new inceptors. A manned multicopter created at AGH University of Science and Technology is an aircraft in which the pilot takes a specific orientation in which classical inceptors may be impractical to use. In this paper, a unique kind of control inceptor is described, which aims to provide a handling quality not unlike standard solutions, and provide a firm grip point for the pilot without the risk of involuntary stick movement. Simulations of the pilot-inceptor model were performed in order to compare the dynamic amplification factors of the design described in this paper with the classical one. A functional prototype is built on which drone pilots carry out a comfort-of-use evaluation. This paper provides a general overview of the project, including a literature review, reasoning behind components selection, and mechanism design finalized by conclusions.Keywords: mechanisms, mechatronics, embedded control, serious gaming for training rescue missions, rescue robotics
Procedia PDF Downloads 8629486 Rescaling Global Health and International Relations: Globalization of Health in a Low Security Environment
Authors: F. Argurio, F. G. Vaccaro
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In a global environment defined by ever-increasing health issues, in spite of the progress made by modern medicine, this paper seeks to readdress the question of global health in an international relations perspective. The research hypothesis is: the lower the security environment, the higher the spread of communicable diseases. This question will be channeled by re-scaling the connotation of 'global' and 'international' dimension through the theoretical lens of glocalization, a theory by Bauman that starts its analysis from simple systems to get to the most complex ones. Glocalization theory will be operationalized by analyzing health in an armed-conflict context. In this respect, the independent variable 'low security environment' translates into the cases of Syria and Yemen, which provide a clear example of the all-encompassing nature of conflict on national health and the effects on regional development. In fact, Syria and Yemen have been affected by poliomyelitis and cholera outbreaks respectively. The dependent variable will be constructed on said communicable diseases which belong to the families of sanitation-related and vaccine-preventable diseases. The research will be both qualitative and quantitative, based on primary (interviews) and secondary (WHO and other NGO’s reports) sources. The methodology is based on the assessment of the vaccine coverage and case-analysis in time and space using epidemiological data. Moreover, local health facilities’ functioning and efficiency will be studied. The article posits that the intervention and cooperation of international organizations with the local authorities becomes crucial to provide the local populations with their primary health needs. In Yemen, the majority of fatal cholera cases were in the regions controlled by the Houthi rebels, not officially accredited by the International Community. Similarly, the polio outbreak in Syria primarily affected the areas not controlled by the Syrian Arab Republic forces, recognized as the leading interlocutor by the WHO. The jeopardized possibilities to access these countries have been pivotal to the determining the problem in controlling sanitation-related and vaccine preventable diseases. This represents a potential threat to global health.Keywords: health in conflict-affected areas, cholera, polio, Yemen, Syria, glocalization
Procedia PDF Downloads 13729485 Study of the Economic Development of Border Areas Malinau District
Authors: Indri Nilam Sari, Aris Subagiyo, Nindya Sari
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Malinau Regency border area is an area which is based on the RTRWN and the development priority. But, in real border area Malinau Regency placed as backyard from Indonesian area and caused development lag that is fairly large compared by town area in Malinau Regency. This research aimed to know the condition of the gap in the Malinau Regency border and its influence on the development of the border region as well as knowing the problems related to the economy development of society in the area of the border district of Malinau. Methods of analysis are used in namely descriptive analysis that represent analysis of land use and analysis of movement activities of the population, level analysis facility and infrastructure, economy analysis that represent top commodity determination analysis (LQ and Growth Share) and accessibility. The results of the study showed that the condition of the Malinau Regency border come within the gap as seen from the contributions of infrastructure repair facilities and accessibility advocates, communities, scattered seed commodities come within the borders and human resources with the condition of the most Upstream Bahau town in the backwaters of the town more. There are a few problems that cause the condition area of the border experiencing inequality, lack of human resources, poor infrastructure, lack of accessibility and low levels of security so that it brings development recommendations was the development of the flagship commodities and infrastructure as well as supporting community economic infrastructure, as well as human resources.Keywords: border, economy, development, Malinau
Procedia PDF Downloads 45529484 Exploring the Influence of Maternal Self-Discrepancy on Psychological Well-Being: A Study of Middle-Aged Japanese Mothers
Authors: Chooi Fong Lee
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Maternal psychological well-being has been investigated from various aspects, such as social support, employment status. However, a perspective from self-discrepancy theory has not been employed. Moreover, most were focused on young mothers. Less is understanding the middle-aged mother’s psychological well-being. This research examined the influence of maternal self-discrepancy between actual and ideal self on maternal role achievement, state anxiety, trait anxiety, and subjective well-being among Japanese middle-aged mothers across their employment status. A pilot study with 20 Japanese mother participants (aged 40-55, 9 regular-employed, 8 non-regular-employed, and 3 homemakers) was conducted to assess the viability of survey questionnaires (Maternal Role Achievement Scale, State-Trait Anxiety Inventory, Subjective Well-being Scale, and Self-report questionnaire). The self-report questionnaire prompted participants to list up to 3 ideal selves they aspired to be and rate the extent to which their actual selves deviated from their ideal selves on a 7-point scale (1= not at all; 4 = medium; 7 = extremely). Self-discrepancy scores were calculated by subtracting participants’ degree ratings from a 7-point scale, summing them up, and then dividing the total by 3. The final sample consisted of 241 participants, 97 regular-employed, 87 non-regular employed, and 57 homemaker mothers. We ensured participants were randomly selected to mitigate bias. The results show that regular-employed mothers tend to exhibit lower self-discrepancy scores compared to non-regular employed and homemaker mothers. Moreover, the discrepancy between actual and ideal self negatively correlated with maternal role achievement, state anxiety, and subjective well-being, while positively correlated with trait anxiety. Trait anxiety arises when one feels they did not meet their ideal self, as evidenced by higher levels in homemaker mothers, who experience lower state anxiety. Conversely, regular-employed mothers exhibit higher state anxiety but lower trait anxiety, suggesting satisfaction in their professional pursuits despite balancing work and family responsibilities. Full-time maternal roles contribute to lower state anxiety but higher trait anxiety among homemaker mothers due to a lack of personal identity achievement. Non-regular employed mothers show similarities to homemaker mothers. In self-reports, regular-employed mothers highlight support and devotion to their children’s development, while non-regular-employed mothers seek life fulfillment through part-time work alongside child-rearing duties. Homemaker mothers emphasize qualities like sociability, and communication skills, potentially influencing their self-discrepancy scores. Furthermore, the hierarchical multiple regression analysis revealed that the discrepancy between actual and ideal self significantly predicts subjective well-being. In conclusion, the findings offer valuable insights into the impact of maternal self-discrepancy on psychological well-being among middle-aged Japanese mothers across different employment statuses. Understanding these dynamics becomes crucial as contemporary women increasingly pursue higher education and depart from traditional motherhood norms. Working toward one ideal self might contribute to a mother psychological well-being. Acknowledgment: This project was made possible with funding support from the Japan ICU Foundation.Keywords: maternal employment, maternal role, self-discrepancy, state-trait anxiety, subjective well-being
Procedia PDF Downloads 7829483 Classification of EEG Signals Based on Dynamic Connectivity Analysis
Authors: Zoran Šverko, Saša Vlahinić, Nino Stojković, Ivan Markovinović
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In this article, the classification of target letters is performed using data from the EEG P300 Speller paradigm. Neural networks trained with the results of dynamic connectivity analysis between different brain regions are used for classification. Dynamic connectivity analysis is based on the adaptive window size and the imaginary part of the complex Pearson correlation coefficient. Brain dynamics are analysed using the relative intersection of confidence intervals for the imaginary component of the complex Pearson correlation coefficient method (RICI-imCPCC). The RICI-imCPCC method overcomes the shortcomings of currently used dynamical connectivity analysis methods, such as the low reliability and low temporal precision for short connectivity intervals encountered in constant sliding window analysis with wide window size and the high susceptibility to noise encountered in constant sliding window analysis with narrow window size. This method overcomes these shortcomings by dynamically adjusting the window size using the RICI rule. This method extracts information about brain connections for each time sample. Seventy percent of the extracted brain connectivity information is used for training and thirty percent for validation. Classification of the target word is also done and based on the same analysis method. As far as we know, through this research, we have shown for the first time that dynamic connectivity can be used as a parameter for classifying EEG signals.Keywords: dynamic connectivity analysis, EEG, neural networks, Pearson correlation coefficients
Procedia PDF Downloads 21829482 A Discrete Event Simulation Model For Airport Runway Operations Optimization (Case Study)
Authors: Awad Khireldin, Colin Law
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Runways are the major infrastructure of airports around the world. Efficient operations of runways are key to ensure that airports are running smoothly with minimal delays. There are many factors that affect the efficiency of runway operations, such as the aircraft wake separation, runways system configuration, the fleet mix, and the runways separation distance. This paper aims to address how to maximize runway operations using a Discrete Event Simulation model. A case study of Cairo International Airport (CIA) is developed to maximize the utilizing of three parallel runways using a simulation model. Different scenarios have been designed where every runway could be assigned for arrival, departure, or mixed operations. A benchmarking study was also included to compare the actual to the proposed results to spot the potential improvements. The simulation model shows that there is a significant difference in utilization and delays between the actual and the proposed ones, there are several recommendations that can be provided to airport management, in the short and long term, to increase the efficiency and to reduce the delays. By including the recommendation with different operations scenarios, such as upgrading the airport slot Coordination from Level 1 to Level 2 in the short term. In the long run, discuss the possibilities to increase the International Air Transport association (IATA) slot coordination to Level 3 as more flights are expected to be handled by the airport. Technological advancements such as radar in the approach full airside simulation model could improve the airport performance where the airport is recommended to review the standard operations procedures with the appropriate authorities. Also, the airport can adopt a future operational plan to accommodate the forecasted additional traffic density in case of adding a fourth terminal building to increase the airport capacity.Keywords: airport performance, runway, discrete event simulation, capacity, airside
Procedia PDF Downloads 14729481 Heat Pipe Production and Life Performance Tests in Geosynchronous Telecom Satellites
Authors: Erkam Arslantas
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Heat pipes one of the thermal control elements are used in communication satellites. A selection of the heat pipes of satellite thermal design will be emphasized how important and effective it is. In this article, manufacturing and performance control tests of heat pipes are reviewed from the current literature. The heat pipe is expected to function efficiently during all missions of the spacecraft from Beginning of Life (BOL) to End of Life (EOL). There are many parameters that are evaluated in manufacturing and performance control tests of the heat pipes which are used in satellites. These parameters are pressure design, leakage, noncondensable gas level (N.C.G), sine vibration, shock and static load capabilities, aging, bending, proof, final test etc. These parameters will be explained separately for the heat pipes in this review article and young researches working on the thermal control system of Geosynchronous Satellites systems can find easily related information in this article.Keywords: communication satellite, heat pipe, performance test, thermal control
Procedia PDF Downloads 17229480 Credit Risk Evaluation Using Genetic Programming
Authors: Ines Gasmi, Salima Smiti, Makram Soui, Khaled Ghedira
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Credit risk is considered as one of the important issues for financial institutions. It provokes great losses for banks. To this objective, numerous methods for credit risk evaluation have been proposed. Many evaluation methods are black box models that cannot adequately reveal information hidden in the data. However, several works have focused on building transparent rules-based models. For credit risk assessment, generated rules must be not only highly accurate, but also highly interpretable. In this paper, we aim to build both, an accurate and transparent credit risk evaluation model which proposes a set of classification rules. In fact, we consider the credit risk evaluation as an optimization problem which uses a genetic programming (GP) algorithm, where the goal is to maximize the accuracy of generated rules. We evaluate our proposed approach on the base of German and Australian credit datasets. We compared our finding with some existing works; the result shows that the proposed GP outperforms the other models.Keywords: credit risk assessment, rule generation, genetic programming, feature selection
Procedia PDF Downloads 35829479 Analysis of Thermoelectric Coolers as Energy Harvesters for Low Power Embedded Applications
Authors: Yannick Verbelen, Sam De Winne, Niek Blondeel, Ann Peeters, An Braeken, Abdellah Touhafi
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The growing popularity of solid state thermoelectric devices in cooling applications has sparked an increasing diversity of thermoelectric coolers (TECs) on the market, commonly known as “Peltier modules”. They can also be used as generators, converting a temperature difference into electric power, and opportunities are plentiful to make use of these devices as thermoelectric generators (TEGs) to supply energy to low power, autonomous embedded electronic applications. Their adoption as energy harvesters in this new domain of usage is obstructed by the complex thermoelectric models commonly associated with TEGs. Low cost TECs for the consumer market lack the required parameters to use the models because they are not intended for this mode of operation, thereby urging an alternative method to obtain electric power estimations in specific operating conditions. The design of the test setup implemented in this paper is specifically targeted at benchmarking commercial, off-the-shelf TECs for use as energy harvesters in domestic environments: applications with limited temperature differences and space available. The usefulness is demonstrated by testing and comparing single and multi stage TECs with different sizes. The effect of a boost converter stage on the thermoelectric end-to-end efficiency is also discussed.Keywords: thermoelectric cooler, TEC, complementary balanced energy harvesting, step-up converter, DC/DC converter, energy harvesting, thermal harvesting
Procedia PDF Downloads 26729478 Sun Protection Factor (SPF) Determination of Sericin Cream and Niosomal Gel
Authors: Farzad Doostishoar, Abbas Pardakhty, Abdolreza Hassanzadeh, Sudeh salarpour, Elham Sharif
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Background: Sericin is a protein extracted from silk and has antioxidant, antimicrobial, antineoplastic, wound healing and moisturizing properties. Different cosmetic formulation of sericin is available in different countries such as Japan and the other south-eastern Asian countries. We formulated and evaluated the sunscreen properties of topical formulations of sericin by an in vitro method. Method: Niosomes composed of sorbitan palmitate (Span 40), polysorbate 40 (Tween 40) and cholesterol (300 µmol, 3.5:3.5:3 molar ratio) were prepared by film hydration technique. Sericin was dissolved in normal saline and the lipid hydration was carried out at 60°C and the niosomes were incorporated in a Carbomer gel base. A W/O cream was also prepared and the release of sericin was evaluated by using Franz diffusion cell. Particle size analysis, sericin encapsulation efficiency measurement, morphological studies and stability evaluation were done in niosomal formulations. SPF was calculated by using Transpore tape in vitro method for both formulations. Results: Niosomes had high stability during 6 months storage at 4-8°C. The mean volume diameter of niosomes was less than 7 µm which is ideal for sustained release of drugs in topical formulations. The SPF of niosomal gel was 25 and higher than sericin cream with a diffusion based release pattern of active material. Conclusion: Sericin can be successfully entrapped in niosomes with sustained release pattern and relatively high SPF.Keywords: sericin, niosomes, sun protection factor, cream, gel
Procedia PDF Downloads 50529477 A Comparative Analysis of Asymmetric Encryption Schemes on Android Messaging Service
Authors: Mabrouka Algherinai, Fatma Karkouri
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Today, Short Message Service (SMS) is an important means of communication. SMS is not only used in informal environment for communication and transaction, but it is also used in formal environments such as institutions, organizations, companies, and business world as a tool for communication and transactions. Therefore, there is a need to secure the information that is being transmitted through this medium to ensure security of information both in transit and at rest. But, encryption has been identified as a means to provide security to SMS messages in transit and at rest. Several past researches have proposed and developed several encryption algorithms for SMS and Information Security. This research aims at comparing the performance of common Asymmetric encryption algorithms on SMS security. The research employs the use of three algorithms, namely RSA, McEliece, and RABIN. Several experiments were performed on SMS of various sizes on android mobile device. The experimental results show that each of the three techniques has different key generation, encryption, and decryption times. The efficiency of an algorithm is determined by the time that it takes for encryption, decryption, and key generation. The best algorithm can be chosen based on the least time required for encryption. The obtained results show the least time when McEliece size 4096 is used. RABIN size 4096 gives most time for encryption and so it is the least effective algorithm when considering encryption. Also, the research shows that McEliece size 2048 has the least time for key generation, and hence, it is the best algorithm as relating to key generation. The result of the algorithms also shows that RSA size 1024 is the most preferable algorithm in terms of decryption as it gives the least time for decryption.Keywords: SMS, RSA, McEliece, RABIN
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