Search results for: balance and stability
4589 Energy Management Method in DC Microgrid Based on the Equivalent Hydrogen Consumption Minimum Strategy
Authors: Ying Han, Weirong Chen, Qi Li
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An energy management method based on equivalent hydrogen consumption minimum strategy is proposed in this paper aiming at the direct-current (DC) microgrid consisting of photovoltaic cells, fuel cells, energy storage devices, converters and DC loads. The rational allocation of fuel cells and battery devices is achieved by adopting equivalent minimum hydrogen consumption strategy with the full use of power generated by photovoltaic cells. Considering the balance of the battery’s state of charge (SOC), the optimal power of the battery under different SOC conditions is obtained and the reference output power of the fuel cell is calculated. And then a droop control method based on time-varying droop coefficient is proposed to realize the automatic charge and discharge control of the battery, balance the system power and maintain the bus voltage. The proposed control strategy is verified by RT-LAB hardware-in-the-loop simulation platform. The simulation results show that the designed control algorithm can realize the rational allocation of DC micro-grid energy and improve the stability of system.Keywords: DC microgrid, equivalent minimum hydrogen consumption strategy, energy management, time-varying droop coefficient, droop control
Procedia PDF Downloads 2964588 Rate of Profit as a Pricing Benchmark in Islamic Banking to Create Financial Stability
Authors: Trisiladi Supriyanto
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Although much research has been done on the pricing benchmark both in terms of fiqh or Islamic economic perspective, but no substitution for the concept of interest (rate of interest) up to now in the application of Islamic Banking because some of the jurists from the middle east even allow the use of a benchmark rate such as LIBOR (London Interbank Offered Rate) as a measure of Islamic financial asset prices, so in other words, they equate the concept of rate of interest with the concept of rate of profit, which is the core reason (raison detre) for the replacement of usury as instructed in the Quran. This study aims to find the concept of rate of profit on Islamic banking that can create economic justice and stability in Islamic Banking and Capital market. Rate of profit that creates economic justice and stability can be achieved through its role in maintaining the stability of the financial system in which there is an equitable distribution of income and wealth. To determine the role of the rate of profit as the basis of the sharing system implemented in the Islamic financial system, we can see the connection of rate of profit in creating financial stability, especially in the asset-liability management of financial institutions that generate a stable net margin or the rate of profit that is not affected by the ups and downs of the market risk factors including indirect effect on interest rates. Furthermore, Islamic financial stability can be seen from the role of the rate of profit on the stability of the Islamic financial assets that are measured from the Islamic financial asset price volatility in Islamic Bond Market in Capital Market.Keywords: Rate of profit, economic justice, stability, equitable distribution of income, equitable distribution of wealth
Procedia PDF Downloads 3984587 Near-Infrared Spectrometry as an Alternative Method for Determination of Oxidation Stability for Biodiesel
Authors: R. Velvarska, A. Vrablik, M. Fiedlerova, R. Cerny
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Near-infrared spectrometry (NIR) was tested as a rapid and alternative tool for determination of biodiesel oxidation stability. A PetroOxy method is standardly used for the determination, but this method is hazardous due to the possibility of explosion and ignition of flammable fuels. The second disadvantage is time consuming. The near-infrared spectrometry served for the development of the calibration model which was composed of 133 real samples (calibration standards). The reference values of these standards were obtained by PetroOxy method. Many chemometric diagnostics were used for the development of the final NIR model with the aim to have accurate prediction of the oxidation stability. The final NIR model was validated by 30 validation standards. The repeatability was determined as well with the acceptable residual standard deviation (8.59 %). The NIR spectrometry has proved to be an accurate alternative method for the determination of biodiesel oxidation stability with advantages as the time and cost saving, non-destructive character of analyzing and the possibility of online monitoring in safe mode.Keywords: biodiesel, fatty acid methyl ester, NIR, oxidation stability
Procedia PDF Downloads 1704586 An Improved Cuckoo Search Algorithm for Voltage Stability Enhancement in Power Transmission Networks
Authors: Reza Sirjani, Nobosse Tafem Bolan
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Many optimization techniques available in the literature have been developed in order to solve the problem of voltage stability enhancement in power systems. However, there are a number of drawbacks in the use of previous techniques aimed at determining the optimal location and size of reactive compensators in a network. In this paper, an Improved Cuckoo Search algorithm is applied as an appropriate optimization algorithm to determine the optimum location and size of a Static Var Compensator (SVC) in a transmission network. The main objectives are voltage stability improvement and total cost minimization. The results of the presented technique are then compared with other available optimization techniques.Keywords: cuckoo search algorithm, optimization, power system, var compensators, voltage stability
Procedia PDF Downloads 5424585 Application of Liquid Chromatographic Method for the in vitro Determination of Gastric and Intestinal Stability of Pure Andrographolide in the Extract of Andrographis paniculata
Authors: Vijay R. Patil, Sathiyanarayanan Lohidasan, K. R. Mahadik
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Gastrointestinal stability of andrographolide was evaluated in vitro in simulated gastric (SGF) and intestinal (SIF) fluids using a validated HPLC-PDA method. The method was validated using a 5μm ThermoHypersil GOLD C18column (250 mm × 4.0 mm) and mobile phase consisting of water: acetonitrile; 70: 30 (v/v) delivered isocratically at a flow rate of 1 mL/min with UV detection at 228 nm. Andrographolide in pure form and extract Andrographis paniculata was incubated at 37°C in an incubator shaker in USP simulated gastric and intestinal fluids with and without enzymes. Systematic protocol as per FDA Guidance System was followed for stability study and samples were assayed at 0, 15, 30 and 60 min intervals for gastric and at 0, 15, 30, 60 min, 1, 2 and 3 h for intestinal stability study. Also, the stability study was performed up to 24 h to see the degradation pattern in SGF and SIF (with enzyme and without enzyme). The developed method was found to be accurate, precise and robust. Andrographolide was found to be stable in SGF (pH ∼ 1.2) for 1h and SIF (pH 6.8) up to 3 h. The relative difference (RD) of amount of drug added and found at all time points was found to be < 3%. The present study suggests that drug loss in the gastrointestinal tract takes place may be by membrane permeation rather than a degradation process.Keywords: andrographolide, Andrographis paniculata, in vitro, stability, gastric, Intestinal HPLC-PDA
Procedia PDF Downloads 2414584 H∞robust Control Law for a Speed Dc Motor in Both Directions of Rotation
Authors: Ben Abdallah Aicha
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In this work we show a H∞ synthesis method which enables us to calculate a feedback controller according to considerations of stability robustness and disturbance rejection translated on to the open loop response. However, it may happen that we have an additional specification on the closed loop response relating to tracking of the reference trajectory. The H∞ synthesis has the advantage of offering increased specifications in robustness stability. Implemented for a DC motor, it offers invaluable performance in speed control in both directions of rotation.Keywords: H∞ synthesis, DC motor, robustness stability, performance conditions
Procedia PDF Downloads 714583 Features of Rail Strength Analysis in Conditions of Increased Force Loading
Authors: G. Guramishvili, M. Moistsrapishvili, L. Andghuladze
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In the article are considered the problems arising at increasing of transferring from rolling stock axles on rail loading from 210 KN up to 270 KN and is offered for rail strength analysis definition of rail force loading complex integral characteristic with taking into account all affecting force factors that is characterizing specific operation condition of rail structure and defines the working capability of structure. As result of analysis due mentioned method is obtained that in the conditions of 270 KN loading the rail meets the working assessment criteria of rail and rail structures: Strength, rail track stability, rail links stability and its transverse stability, traffic safety condition that is rather important for post-Soviet countries railways.Keywords: axial loading, rail force loading, rail structure, rail strength analysis, rail track stability
Procedia PDF Downloads 4214582 Factors Affecting Test Automation Stability and Their Solutions
Authors: Nagmani Lnu
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Test automation is a vital requirement of any organization to release products faster to their customers. In most cases, an organization has an approach to developing automation but struggles to maintain it. It results in an increased number of Flaky Tests, reducing return on investments and stakeholders’ confidence. Challenges grow in multiple folds when automation is for UI behaviors. This paper describes the approaches taken to identify the root cause of automation instability in an extensive payments application and the best practices to address that using processes, tools, and technologies, resulting in a 75% reduction of effort.Keywords: automation stability, test stability, Flaky Test, test quality, test automation quality
Procedia PDF Downloads 754581 Determining the Width and Depths of Cut in Milling on the Basis of a Multi-Dexel Model
Authors: Jens Friedrich, Matthias A. Gebele, Armin Lechler, Alexander Verl
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Chatter vibrations and process instabilities are the most important factors limiting the productivity of the milling process. Chatter can leads to damage of the tool, the part or the machine tool. Therefore, the estimation and prediction of the process stability is very important. The process stability depends on the spindle speed, the depth of cut and the width of cut. In milling, the process conditions are defined in the NC-program. While the spindle speed is directly coded in the NC-program, the depth and width of cut are unknown. This paper presents a new simulation based approach for the prediction of the depth and width of cut of a milling process. The prediction is based on a material removal simulation with an analytically represented tool shape and a multi-dexel approach for the work piece. The new calculation method allows the direct estimation of the depth and width of cut, which are the influencing parameters of the process stability, instead of the removed volume as existing approaches do. The knowledge can be used to predict the stability of new, unknown parts. Moreover with an additional vibration sensor, the stability lobe diagram of a milling process can be estimated and improved based on the estimated depth and width of cut.Keywords: dexel, process stability, material removal, milling
Procedia PDF Downloads 5154580 Super-Hydrophilic TFC Membrane with High Stability in Oil
Authors: M. Obaid, Nasser A. M. Barakat, Fadali O.A
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Low stability in oil media and the hydrophobicity problems of the ploysulfone electrospun membranes could be overcome in the present study. Synthesis of super-hydrophilic and highly stable in oil polysulfone electrospun nanofiber membrane was achieved by electrospinning of polysulfone solution containing NaOH salt followed by activation of the dried electrospun membrane by deposition of polyamide layer on the surface using m-phenylenediamine and 1,3,5-benzenetricarbonyl chloride. The introduced membrane has super-hydrophilicity characteristic (contact angle=3o), excellent stability in oil media and distinct performance in oil-water separation process.Keywords: electrospinning, oil-degradability, membrane, nanofibers
Procedia PDF Downloads 4754579 Competition, Stability, and Economic Growth: A Causality Approach
Authors: Mahvish Anwaar
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Research Question: In this paper, we explore the causal relationship between banking competition, banking stability, and economic growth. Research Findings: The unbalanced panel data starting from 2000 to 2018 is collected to analyze the causality among banking competition, banking stability, and economic growth. The main focus of the study is to check the direction of causality among selected variables. The results of the study support the demand following, supply leading, feedback, and neutrality hypothesis conditional to different measures of banking competition, banking stability, and economic growth. Theoretical Implication: Jayakumar, Pradhan, Dash, Maradana, and Gaurav (2018) proposed a theoretical model of the causal relationship between banking competition, banking stability, and economic growth by using different indicators. So, we empirically test the proposed indicators in our study. This study makes a contribution to the literature by showing the defined relationship between developing and developed countries. Policy Implications: The study covers various policy implications regarding investors to analyze how to properly manage their finances, and government agencies will take help from the present study to find the best and most suitable policies by examining how the economy can grow concerning its finances.Keywords: competition, stability, economic growth, vector auto-regression, granger causality
Procedia PDF Downloads 574578 From Battles to Balance and Back: Document Analysis of EU Copyright in the Digital Era
Authors: Anette Alén
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Intellectual property (IP) regimes have traditionally been designed to integrate various conflicting elements stemming from private entitlement and the public good. In IP laws and regulations, this design takes the form of specific uses of protected subject-matter without the right-holder’s consent, or exhaustion of exclusive rights upon market release, and the like. More recently, the pursuit of ‘balance’ has gained ground in the conceptualization of these conflicting elements both in terms of IP law and related policy. This can be seen, for example, in European Union (EU) copyright regime, where ‘balance’ has become a key element in argumentation, backed up by fundamental rights reasoning. This development also entails an ever-expanding dialogue between the IP regime and the constitutional safeguards for property, free speech, and privacy, among others. This study analyses the concept of ‘balance’ in EU copyright law: the research task is to examine the contents of the concept of ‘balance’ and the way it is operationalized and pursued, thereby producing new knowledge on the role and manifestations of ‘balance’ in recent copyright case law and regulatory instruments in the EU. The study discusses two particular pieces of legislation, the EU Digital Single Market (DSM) Copyright Directive (EU) 2019/790 and the finalized EU Artificial Intelligence (AI) Act, including some of the key preparatory materials, as well as EU Court of Justice (CJEU) case law pertaining to copyright in the digital era. The material is examined by means of document analysis, mapping the ways ‘balance’ is approached and conceptualized in the documents. Similarly, the interaction of fundamental rights as part of the balancing act is also analyzed. Doctrinal study of law is also employed in the analysis of legal sources. This study suggests that the pursuit of balance is, for its part, conducive to new battles, largely due to the advancement of digitalization and more recent developments in artificial intelligence. Indeed, the ‘balancing act’ rather presents itself as a way to bypass or even solidify some of the conflicting interests in a complex global digital economy. Indeed, such a conceptualization, especially when accompanied by non-critical or strategically driven fundamental rights argumentation, runs counter to the genuine acknowledgment of new types of conflicting interests in the copyright regime. Therefore, a more radical approach, including critical analysis of the normative basis and fundamental rights implications of the concept of ‘balance’, is required to readjust copyright law and regulations for the digital era. Notwithstanding the focus on executing the study in the context of the EU copyright regime, the results bear wider significance for the digital economy, especially due to the platform liability regime in the DSM Directive and with the AI Act including objectives of a ‘level playing field’ whereby compliance with EU copyright rules seems to be expected among system providers.Keywords: balance, copyright, fundamental rights, platform liability, artificial intelligence
Procedia PDF Downloads 274577 Global Stability Analysis of a Coupled Model for Healthy and Cancerous Cells Dynamics in Acute Myeloid Leukemia
Authors: Abdelhafid Zenati, Mohamed Tadjine
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The mathematical formulation of biomedical problems is an important phase to understand and predict the dynamic of the controlled population. In this paper we perform a stability analysis of a coupled model for healthy and cancerous cells dynamics in Acute Myeloid Leukemia, this represents our first aim. Second, we illustrate the effect of the interconnection between healthy and cancer cells. The PDE-based model is transformed to a nonlinear distributed state space model (delay system). For an equilibrium point of interest, necessary and sufficient conditions of global asymptotic stability are given. Thus, we came up to give necessary and sufficient conditions of global asymptotic stability of the origin and the healthy situation and control of the dynamics of normal hematopoietic stem cells and cancerous during myelode Acute leukemia. Simulation studies are given to illustrate the developed results.Keywords: distributed delay, global stability, modelling, nonlinear models, PDE, state space
Procedia PDF Downloads 2484576 The Nexus between Counter Terrorism and Human Rights with a Perspective on Cyber Terrorism
Authors: Allan Munyao Mukuki
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The nexus between terrorism and human rights has become a big challenge in the fight against terrorism globally. This is hinged on the fact that terrorism and human rights are interrelated to the extent that, when the former starts, the latter is violated. This direct linkage was recognised in the Vienna Declaration and Programme of Action as adopted by the World Conference on Human Rights in Vienna on 25 June 1993 which agreed that acts of terrorism in all its forms and manifestations are aimed at the destruction of human rights. Hence, terrorism constitutes an assault on our most basic human rights. To this end, the first part of this paper will focus on the nexus between terrorism and human rights and endeavors to draw a co-relation between these two concepts. The second part thereafter will analyse the emerging concept of cyber-terrorism and how it takes place. Further, an analysis of cyber counter-terrorism balanced as against human rights will also be undertaken. This will be done through the analysis of the concept of ‘securitisation’ of human rights as well as the need to create a balance between counterterrorism efforts as against the protection of human rights at all costs. The paper will then concludes with recommendations on how to balance counter-terrorism and human rights in the modern age.Keywords: balance, counter-terrorism, cyber-terrorism, human rights, security, violation
Procedia PDF Downloads 3964575 The Impact of Black Rice Ash Nanoparticles on Foam Stability through Foam Scanning in Enhanced Oil Recovery
Authors: Ishaq Ahmad, Zhaomin Li, Liu Chengwen, Song Yan Li, Zihan Gu, Li Shaopeng
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In order to manage gas mobility in the reservoir, only a small amount of surfactant or polymer is needed because nanoparticles have the potential to improve foam stability. The aim is to enhance foam formation and stability, so it was decided to investigate the foam stability and foam ability of black rice husk ash. Several characterization techniques were used to investigate the properties of black rice husk ash. The best-performing anionic foaming surfactants were combined with black rice husk ash at different concentrations (ppm). Sodium dodecyl benzene sulphonate was used as the anionic surfactant. This study demonstrates the value of black rice husk ash (BRHA), which has a high silica concentration, for foam stability and ability. For the test, black rice husk ash and raw ash were used with SDS (Sodium Dodecyl Sulfate) and SDBS (Sodium dodecyl benzenesulfonate) surfactants under different parameters. Different concentration percentages were utilized to create the foam, and the hydrophobic test and shaking method were applied. The foam scanner was used to observe the behavior of the black rice husk ash foam. The high silica content of black rice husk ash has the potential to improve foam stability, which is favorable and could possibly improve oil recovery.Keywords: black rice husk ash nanoparticle, surfactant, foam life, foam scanning
Procedia PDF Downloads 1444574 Assessment of the Impact of Regular Pilates Exercises on Static Balance in Healthy Adult Women: Preliminary Report
Authors: Anna Słupik, Krzysztof Jaworski, Anna Mosiołek, Dariusz Białoszewski
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Background: Maintaining the correct body balance is essential in the prevention of falls in the elderly, which is especially important for women because of postmenopausal osteoporosis and the serious consequences of falls. One of the exercise methods which is very popular among adults, and which may affect body balance in a positive way is the pilates method. The aim of the study was to evaluate the effect of regular pilates exercises on the ability to maintain body balance in static conditions in adult healthy women. Material and methods: The study group consisted of 20 healthy women attending pilates twice a week for at least 1 year. The control group consisted of 20 healthy women physically inactive. Women in the age range from 35 to 50 years old without pain in musculoskeletal system or other pain were only qualified to the groups. Body balance was assessed using MatScan VersaTek platform with Sway Analysis Module based on Matscan Clinical 6.7 software. The balance was evaluated under the following conditions: standing on both feet with eyes open, standing on both feet with eyes closed, one-leg standing (separately on the right and left foot) with eyes open. Each test lasted 30 seconds. The following parameters were calculated: estimated size of the ellipse of 95% confidence, the distance covered by the Center of Gravity (COG), the size of the maximum shift in the sagittal and frontal planes and load distribution between the left and right foot, as well as between rear- and forefoot. Results: It was found that there is significant difference between the groups in favor of the study group in the size of the confidence ellipse and maximum shifts of COG in the sagittal plane during standing on both feet, both with the eyes open and closed (p < 0.05). While standing on one leg both on the right and left leg, with eyes opened there was a significant difference in favor of the study group, in terms of the size of confidence ellipse, the size of the maximum shifts in the sagittal and in the frontal plane (p < 0.05). There were no differences between the distribution of load between the right and left foot (standing with both feet), nor between fore- and rear foot (in standing with both feet or one-leg). Conclusions: 1. Static balance in women exercising regularly by pilates method is better than in inactive women, which may in the future prevent falls and their consequences. 2. The observed differences in maintaining balance in frontal plane in one-leg standing may indicate a positive impact of pilates exercises on the ability to maintain global balance in terms of the reduced support surface. 3. Pilates method can be used as a form preventive therapy for all people who are expected to have problems with body balance in the future, for example in chronic neurological disorders or vestibular problems. 4. The results have shown that further prospective randomized research on a larger and more representative group is needed.Keywords: balance exercises, body balance, pilates, pressure distribution, women
Procedia PDF Downloads 3094573 Fortification of Concentrated Milk Protein Beverages with Soy Proteins: Impact of Divalent Cations and Heating Treatment on the Physical Stability
Authors: Yichao Liang, Biye Chen, Xiang Li, Steven R. Dimler
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This study investigated the effects of adding calcium and magnesium chloride on heat and storage stability of milk protein concentrate-soy protein isolate (8:2 respectively) mixtures containing 10% w/w total protein subjected to the in-container sterilization (115 °C x 15 min). The particle size does not change when emulsions are heated at pH between 6.7 and 7.3 irrespective of the mixed protein ratio. Increasing concentration of divalent cation salts resulted in an increase in protein particle size, dry sediment formation and sediment height and a decrease in pH, heat stability and hydration in milk protein concentrate-soy protein isolate mixtures solutions on sterilization at 115°C. Fortification of divalent cation salts in milk protein concentrate-soy protein isolate mixture solutions resulted in an accelerated protein sedimentation and two unique sediment regions during accelerated storage stability testing. Moreover, the heat stability decreased upon sterilization at 115°C, with addition of MgCl₂ causing a greater increase in sedimentation velocity and compressibility than CaCl₂. Increasing pH value of protein milk concentrate-soy protein isolate mixtures solutions from 6.7 to 7.2 resulted in an increase in viscosity following the heat treatment. The study demonstrated that the type and concentration of divalent cation salts used strongly impact heat and storage stability of milk protein concentrate-soy protein isolate mixture nutritional beverages.Keywords: divalent cation salts, heat stability, milk protein concentrate, soy protein isolate, storage stability
Procedia PDF Downloads 3214572 Stability of the Wellhead in the Seabed in One of the Marine Reservoirs of Iran
Authors: Mahdi Aghaei, Saeid Jamshidi, Mastaneh Hajipour
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Effective factors on the mechanical wellbore stability are divided in to two categories: 1) Controllable factors, 2) Uncontrollable factors. The purpose of geo-mechanical modeling of wells is to determine the limit of controlled parameters change based on the stress regime at each point and by solving the governing equations the pore-elastic environment around the well. In this research, the mechanical analysis of wellbore stability was carried out for Soroush oilfield. For this purpose, the geo-mechanical model of the field is made using available data. This model provides the necessary parameters for obtaining the distribution of stress around the wellbore. Initially, a basic model was designed to perform various analysis, based on obtained data, using Abaqus software. All of the subsequent sensitivity analysis such as sensitivity analysis on porosity, permeability, etc. was done on the same basic model. The results obtained from these analysis gives various result such as: with the constant geomechanical parameters, and sensitivity analysis on porosity permeability is ineffective. After the most important parameters affecting the wellbore stability and instability are geo-mechanical parameters.Keywords: wellbore stability, movement, stress, instability
Procedia PDF Downloads 2004571 Stability and Performance Improvement of a Two-Degree-of-Freedom Robot under Interaction Using the Impedance Control
Authors: Seyed Reza Mirdehghan, Mohammad Reza Haeri Yazdi
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In this paper, the stability and the performance of a two-degree-of-freedom robot under an interaction with a unknown environment has been investigated. The time when the robot returns to its initial position after an interaction and the primary resistance of the robot against the impact must be reduced. Thus, the applied torque on the motor will be reduced. The impedance control is an appropriate method for robot control in these conditions. The stability of the robot at interaction moment was transformed to be a robust stability problem. The dynamic of the unknown environment was modeled as a weight function and the stability of the robot under an interaction with the environment has been investigated using the robust control concept. To improve the performance of the system, a force controller has been designed which the normalized impedance after interaction has been reduced. The resistance of the robot has been considered as a normalized cost function and its value was 0.593. The results has showed reduction of resistance of the robot against impact and the reduction of convergence time by lower than one second.Keywords: impedance control, control system, robots, interaction
Procedia PDF Downloads 4224570 Comparison of the Oxidative Stability of Chinese Vegetable Oils during Repeated Deep-Frying of French Fries
Authors: TranThi Ly, Ligang Yang, Hechun Liu, Dengfeng Xu, Haiteng Zhou, Shaokang Wang, Shiqing Chen, Guiju Sun
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This study aims to evaluate the oxidative stability of Chinese vegetable oils during repeated deep-frying. For frying media, palm oil (PO), sunflower oil (SFO), soybean oil (SBO), and canola oil (CO) were used. French fries were fried in oils heated to 180 ± 50℃. The temperature was kept constant during the eight h of the frying process. The oil quality was measured according to the fatty acid (FA) content, trans fatty acid (TFA) compounds, and chemical properties such as peroxide value (PV), acid value (AV), anisidine value (AnV), and malondialdehyde (MDA). Additionally, the sensory characteristics such as color, flavor, greasiness, crispiness, and overall acceptability of the French fries were assessed. Results showed that the PV, AV, AnV, MDA, and TFA content of SFO, CO, and SBO significantly increased in conjunction with prolonged frying time. During the deep-frying process, the SBO showed the lowest oxidative stability at all indices, while PO retained oxidative stability and generated the lowest level of TFA. The French fries fried in PO also offered better sensory properties than the other oils. Therefore, results regarding oxidative stability and sensory attributes suggested that among the examined vegetable oils, PO appeared to be the best oil for frying food products.Keywords: vegetable oils, French fries, oxidative stability, sensory properties, frying oil
Procedia PDF Downloads 1094569 Flow and Heat Transfer over a Shrinking Sheet: A Stability Analysis
Authors: Anuar Ishak
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The characteristics of fluid flow and heat transfer over a permeable shrinking sheet is studied. The governing partial differential equations are transformed into a set of ordinary differential equations, which are then solved numerically using MATLAB routine boundary value problem solver bvp4c. Numerical results show that dual solutions are possible for a certain range of the suction parameter. A stability analysis is performed to determine which solution is linearly stable and physically realizable.Keywords: dual solutions, heat transfer, shrinking sheet, stability analysis
Procedia PDF Downloads 4124568 Modeling of the Effect of Explosives, Geological and Geotechnical Parameters on the Stability of Rock Masses Case of Marrakech: Agadir Highway, Morocco
Authors: Taoufik Benchelha, Toufik Remmal, Rachid El Hamdouni, Hamou Mansouri, Houssein Ejjaouani, Halima Jounaid, Said Benchelha
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During the earthworks for the construction of Marrakech-Agadir highway in southern Morocco, which crosses mountainous areas of the High Western Atlas, the main problem faced is the stability of the slopes. Indeed, the use of explosives as a means of excavation associated with the geological structure of the terrain encountered can trigger major ruptures and cause damage which depends on the intrinsic characteristics of the rock mass. The study consists of a geological and geotechnical analysis of several unstable zones located along the route, mobilizing millions of cubic meters of rock, with deduction of the parameters influencing slope stability. From this analysis, a predictive model for rock mass stability is carried out, based on a statistic method of logistic regression, in order to predict the geomechanical behavior of the rock slopes constrained by earthworks.Keywords: explosive, logistic regression, rock mass, slope stability
Procedia PDF Downloads 3694567 Geotechnical Characterization of an Industrial Waste Landfill: Stability and Environmental Study
Authors: Maria Santana, Jose Estaire
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Even though recycling strategies are becoming more important in recent years, there is still a huge amount of industrial by-products that are the disposal of at landfills. Due to the size, possible dangerous composition, and heterogeneity, most of the wastes are located at landfills without a basic geotechnical characterization. This lack of information may have an important influence on the correct stability calculations. This paper presents the results of geotechnical characterization of some industrial wastes disposed at one landfill. The shear strength parameters were calculated based on direct shear test results carried out in a large shear box owned by CEDEX, which has a shear plane of 1 x 1 m. These parameters were also compared with the results obtained in a 30 x 30 cm shear box. The paper includes a sensitive analysis of the global safety factor of the landfill's overall stability as a function of shear strength variation. The stability calculations were assessed for various hydrological scenarios to simulate the design and performance of the leachate drainage system. The characterization was completed with leachate tests to study the potential impact on the environment.Keywords: industrial wastes, landfill, leachate tests, stability
Procedia PDF Downloads 1904566 Studies on the Physicochemical Properties of Biolubricants Obtained from Vegetable Oils and Their Oxidative Stability
Authors: Expedito J. S. Parente Jr., Italo C. Rios, Joao Paulo C. Marques, Rosana M. A. Saboya, F. Murilo T. Luna, Célio L. Cavalcante Jr.
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Increasing constraints of environmental regulation around the world have led to higher demand for biodegradable products. Vegetable oils present some properties that may favor their use as biolubricants; however, there are others, such as resistance to oxidation and pour point, which affect possible commercial applications. In this study, the physicochemical properties of biolubricants synthesized from different vegetable oils were evaluated and compared with petroleum-based lubricant and pure vegetable oil. Chemical modifications applied to the original vegetable oil improved their oxidative stability and pour point significantly. The addition of commercial antioxidants to the bio-based lubricants was evaluated, yielding values of oxidative stability close to those of mineral basestock oil.Keywords: biolubricant, vegetable oil, oxidative stability, pour point, antioxidants
Procedia PDF Downloads 3074565 Electronic Stability Control for a 7 DOF Vehicle Model Using Flex Ray and Neuro Fuzzy Techniques
Authors: Praveen Battula
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Any high performance car has the tendency to over steer and Understeer under slippery conditions, An Electronic Stability Control System is needed under these conditions to regulate the steering of the car. It uses Anti-Lock Braking System (ABS) and Traction Control and Wheel Speed Sensor, Steering Angle Sensor, Rotational Speed Sensors to correct the problems. The focus of this paper is to improve the driving dynamics and safety by controlling the forces applied on each wheel. ESC Control the Yaw Stability, traction controls the Roll Stability, where actually the vehicle slip rate and lateral acceleration is controlled. ESC uses differential braking on all four brakes independently to control the vehicle’s motion. A mathematical model is developed in Simulink for the FlexRay based Electronic Stability Control. Vehicle steering is developed using Neuro Fuzzy Logic Controller. 7 Degrees of Freedom Vehicle Model is used as a Plant Model using dSpace autobox. The Performance of the system is assessed using two different road Scenarios, Vehicle Control under standard maneuvering conditions. The entire system is set using Dspace Control Desk. Results are provided by comparison of how a Vehicle with and without Electronic Stability Control which shows an improved performance in control.Keywords: ESC, flexray, chassis control, steering, neuro fuzzy, vehicle dynamics
Procedia PDF Downloads 4424564 A New Approach in a Problem of a Supersonic Panel Flutter
Authors: M. V. Belubekyan, S. R. Martirosyan
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On the example of an elastic rectangular plate streamlined by a supersonic gas flow, we have investigated the phenomenon of divergence and of panel flatter of the overrunning of the gas flow at a free edge under assumption of the presence of concentrated inertial masses and moments at the free edge. We applied a new approach of finding of solution of these problems, which was developed based on the algorithm for an analytical solution finding. This algorithm is easy to use for theoretical studies for the wides circle of nonconservative problems of linear elastic stability. We have established the relation between the characteristics of natural vibrations of the plate and velocity of the streamlining gas flow, which enables one to draw some conclusions on the stability of disturbed motion of the plate depending on the parameters of the system plate-flow. Its solution shows that either the divergence or the localized divergence and the flutter instability are possible. The regions of the stability and instability in space of parameters of the problem are identified. We have investigated the dynamic behavior of the disturbed motion of the panel near the boundaries of region of the stability. The safe and dangerous boundaries of region of the stability are found. The transition through safe boundary of the region of the stability leads to the divergence or localized divergence arising in the vicinity of free edge of the rectangular plate. The transition through dangerous boundary of the region of the stability leads to the panel flutter. The deformations arising at the flutter are more dangerous to the skin of the modern aircrafts and rockets resulting to the loss of the strength and appearance of the fatigue cracks.Keywords: stability, elastic plate, divergence, localized divergence, supersonic panels flutter
Procedia PDF Downloads 4544563 Study on Stability and Wear in a Total Hip Prostheses
Authors: Virgil Florescu, Lucian Capitanu
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The studies performed by the author and presented here focus mainly on the FE simulation of some relevant phenomena related to stability of orthopedic implants, especially those components of Total Hip Prostheses. The objectives are to study the mechanisms of achieving stability of acetabular prosthetic components and the influence of some characteristic parameters, to evaluate the effect of femoral stem fixation modality on the stability of prosthetic component and to predict long-term behavior, to analyze a critical phenomena which influence the loading transfer mechanism through artificial joints and could lead to aseptic loosening – the wear of joint frictional surfaces. After a theoretical background an application is made considering only three activities: normal walking, stair ascending and stair descending. For each activity, this function is maximized in a different locations: if for normal walking the maxima is in the superior-posterior part of the acetabular cup, for stair descending this maxim value could be located rather in the superior-anterior part, for stair ascending being even closer to the central area of the cup.Keywords: THA, acetabular stability, FEM simulation, stresses and displacements, wear tests, wear simulation
Procedia PDF Downloads 2654562 Core Stability Index for Healthy Young Sri Lankan Population
Authors: V. M. B. K. T. Malwanage, S. Samita
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Core stability is one of the major determinants that contribute to preventing injuries, enhance performance, and improve quality of life of the human. Endurance of the four major muscle groups of the central ‘core’ of the human body is identified as the most reliable determinant of core stability amongst the other numerous causes which contribute to readily make one’s core stability. This study aimed to develop a ‘Core Stability Index’ to confer a single value for an individual’s core stability based on the four endurance test scores. Since it is possible that at least some of the test scores are not independent, possibility of constructing a single index using the multivariate method exploratory factor analysis was investigated in the study. The study sample was consisted of 400 healthy young individuals with the mean age of 23.74 ± 1.51 years and mean BMI (Body Mass Index) of 21.1 ± 4.18. The correlation analysis revealed highly significant (P < 0.0001) correlations between test scores and thus construction an index using these highly inter related test scores using the technique factor analysis was justified. The mean values of all test scores were significantly different between males and females (P < 0.0001), and therefore two separate core stability indices were constructed for the two gender groups. Moreover, having eigen values 3.103 and 2.305 for males and females respectively, indicated one factor exists for all four test scores and thus a single factor based index was constructed. The 95% reference intervals constructed using the index scores were -1.64 to 2.00 and -1.56 to 2.29 for males and females respectively. These intervals can effectively be used to diagnose those who need improvement in core stability. The practitioners should find that with a single value measure, they could be more consistent among themselves.Keywords: construction of indices, endurance test scores, muscle endurance, quality of life
Procedia PDF Downloads 1574561 Estimation of Synchronous Machine Synchronizing and Damping Torque Coefficients
Authors: Khaled M. EL-Naggar
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Synchronizing and damping torque coefficients of a synchronous machine can give a quite clear picture for machine behavior during transients. These coefficients are used as a power system transient stability measurement. In this paper, a crow search optimization algorithm is presented and implemented to study the power system stability during transients. The algorithm makes use of the machine responses to perform the stability study in time domain. The problem is formulated as a dynamic estimation problem. An objective function that minimizes the error square in the estimated coefficients is designed. The method is tested using practical system with different study cases. Results are reported and a thorough discussion is presented. The study illustrates that the proposed method can estimate the stability coefficients for the critical stable cases where other methods may fail. The tests proved that the proposed tool is an accurate and reliable tool for estimating the machine coefficients for assessment of power system stability.Keywords: optimization, estimation, synchronous, machine, crow search
Procedia PDF Downloads 1304560 Condition for Plasma Instability and Stability Approaches
Authors: Ratna Sen
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As due to very high temperature of Plasma it is very difficult to confine it for sufficient time so that nuclear fusion reactions to take place, As we know Plasma escapes faster than the binary collision rates. We studied the ball analogy and the ‘energy principle’ and calculated the total potential energy for the whole Plasma. If δ ⃗w is negative, that is decrease in potential energy then the plasma will be unstable. We also discussed different approaches of stability analysis such as Nyquist Method, MHD approximation and Vlasov approach of plasma stability. So that by using magnetic field configurations we can able to create a stable Plasma in Tokamak for generating energy for future generations.Keywords: jello, magnetic field configuration, MHD approximation, energy principle
Procedia PDF Downloads 433