Search results for: economic pressure
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 10579

Search results for: economic pressure

8749 A Hydrometallurgical Route for the Recovery of Molybdenum from Spent Mo-Co Catalyst

Authors: Bina Gupta, Rashmi Singh, Harshit Mahandra

Abstract:

Molybdenum is a strategic metal and finds applications in petroleum refining, thermocouples, X-ray tubes and in making of steel alloy owing to its high melting temperature and tensile strength. The growing significance and economic value of molybdenum has increased interest in the development of efficient processes aiming its recovery from secondary sources. Main secondary sources of Mo are molybdenum catalysts which are used for hydrodesulphurisation process in petrochemical refineries. The activity of these catalysts gradually decreases with time during the desulphurisation process as the catalysts get contaminated with toxic material and are dumped as waste which leads to environmental issues. In this scenario, recovery of molybdenum from spent catalyst is significant from both economic and environmental point of view. Recently ionic liquids have gained prominence due to their low vapour pressure, high thermal stability, good extraction efficiency and recycling capacity. The present study reports recovery of molybdenum from Mo-Co spent leach liquor using Cyphos IL 102[trihexyl(tetradecyl)phosphonium bromide] as an extractant. Spent catalyst was leached with 3.0 mol/L HCl, and the leach liquor containing Mo-870 ppm, Co-341 ppm, Al-508 ppm and Fe-42 ppm was subjected to extraction step. The effect of extractant concentration on the leach liquor was investigated and almost 85% extraction of Mo was achieved with 0.05 mol/L Cyphos IL 102. Results of stripping studies revealed that 2.0 mol/L HNO3 can effectively strip 94% of the extracted Mo from the loaded organic phase. McCabe- Thiele diagrams were constructed to determine the number of stages required for quantitative extraction and stripping of molybdenum and were confirmed by countercurrent simulation studies. According to McCabe- Thiele extraction and stripping isotherms, two stages are required for quantitative extraction and stripping of molybdenum at A/O= 1:1. Around 95.4% extraction of molybdenum was achieved in two-stage counter current at A/O= 1:1 with the negligible extraction of Co and Al. However, iron was coextracted and removed from the loaded organic phase by scrubbing with 0.01 mol/L HCl. Quantitative stripping (~99.5 %) of molybdenum was achieved with 2.0 mol/L HNO₃ in two stages at O/A=1:1. Overall ~95.0% molybdenum with 99 % purity was recovered from Mo-Co spent catalyst. From the strip solution, MoO₃ was obtained by crystallization followed by thermal decomposition. The product obtained after thermal decomposition was characterized by XRD, FE-SEM and EDX techniques. XRD peaks of MoO₃ correspond to molybdite Syn-MoO₃ structure. FE-SEM depicts the rod-like morphology of synthesized MoO₃. EDX analysis of MoO₃ shows 1:3 atomic percentage of molybdenum and oxygen. The synthesised MoO₃ can find application in gas sensors, electrodes of batteries, display devices, smart windows, lubricants and as a catalyst.

Keywords: cyphos Il 102, extraction, spent mo-co catalyst, recovery

Procedia PDF Downloads 158
8748 The Evolution of Spatio-Temporal Patterns of New-Type Urbanization in the Central Plains Economic Region in China

Authors: Sun fang, Zhang Wenxin

Abstract:

This paper establishes an evaluation index system for spatio-temporal patterns of urbanization, with the county as research unit. We use the Entropy Weight method, coefficient variance, the Theil index and ESDA-GIS to analyze spatial patterns and evolutionary characteristics of New-Type Urbanization in the Central Plains Economic Region (CPER) between 2000 and 2011. Results show that economic benefit, non-agricultural employment level and level of market development are the most important factors influencing the level of New-Type Urbanization in the CPER; overall regional differences in New-Type Urbanization have declined while spatial correlations have increased from 2000 to 2011. The overall spatial pattern has changed little, however; differences between the western and eastern areas of the CPER are clear, and the pattern of a strong west and weak east did not change significantly over the study period. Areas with high levels of New-Type Urbanization were mostly distributed along the Beijing-Guangzhou and LongHai Railways on both sides, a new influx of urbanization was tightly clustered around ZhengZhou in the Central Henan Urban Agglomeration, but this trend was found to be weakening slightly. The level of New-Type Urbanization in municipal districts was found to be much higher than it was in the county generally. Provincial borders experienced a lower rate of growth and a lower level of New-Type Urbanization than did any other areas, consistently forming clusters of cold spots and sub-cold spots. The analysis confirms that historical development, location, and diffusion effects of urban agglomeration are the main drivers of changes in New-Type Urbanization patterns in CPER.

Keywords: new-type urbanization, spatial pattern, central plains economic region, spatial evolution

Procedia PDF Downloads 276
8747 Determination of Inflow Performance Relationship for Naturally Fractured Reservoirs: Numerical Simulation Study

Authors: Melissa Ramirez, Mohammad Awal

Abstract:

The Inflow Performance Relationship (IPR) of a well is a relation between the oil production rate and flowing bottom-hole pressure. This relationship is an important tool for petroleum engineers to understand and predict the well performance. In the petroleum industry, IPR correlations are used to design and evaluate well completion, optimizing well production, and designing artificial lift. The most commonly used IPR correlations models are Vogel and Wiggins, these models are applicable to homogeneous and isotropic reservoir data. In this work, a new IPR model is developed to determine inflow performance relationship of oil wells in a naturally fracture reservoir. A 3D black-oil reservoir simulator is used to develop the oil mobility function for the studied reservoir. Based on simulation runs, four flow rates are run to record the oil saturation and calculate the relative permeability for a naturally fractured reservoir. The new method uses the result of a well test analysis along with permeability and pressure-volume-temperature data in the fluid flow equations to obtain the oil mobility function. Comparisons between the new method and two popular correlations for non-fractured reservoirs indicate the necessity for developing and using an IPR correlation specifically developed for a fractured reservoir.

Keywords: inflow performance relationship, mobility function, naturally fractured reservoir, well test analysis

Procedia PDF Downloads 249
8746 Comprehensive Approach to Enhance Green Buildings in Urban Areas

Authors: M. Pena, J. Shin, H. Park

Abstract:

The main objective of any engineering activity is the development of a system that fulfills the specific economic, social or environmental needs. Green growth policies, as a system, targets to satisfy two main needs: economic and environmental growth. Cities are complex systems composed of varied characteristics such as differences in socio-environmental conditions and local affordability, among others. Thus, commissioned policies are required to address these differences and to ensure green development. A more maintainable and justifiable, resource-efficient green growth can be obtained in urban areas if multi-criteria framework of policies relevant to green buildings is designed. Reason is that, this approach fits to target the differences and unique conditions of urban areas. By following the principles of axiomatic design, this paper urges to derive a framework for the application of green buildings policies in urban areas with distinctive socio-economic and environmental characteristics. Functional requirements defined as principles to ensure green growth and design parameters are identified in each set of conditions. Design matrices are constructed for each group of urban areas. Thus, the understanding of the needs and differences for each group of urban areas and the methodology to ensure green buildings is achieved.

Keywords: axiomatic design, green growth, sustainable development, urban planning

Procedia PDF Downloads 333
8745 Computational Analysis of Variation in Thrust of Oblique Detonation Ramjet Engine With Adaptive Inlet

Authors: Aditya, Ganapati Joshi, Vinod Kumar

Abstract:

IN THE MODERN-WARFARE ERA, THE PRIME REQUIREMENT IS A HIGH SPEED AND MACH NUMBER. WHEN THE MISSILES STRIKE IN THE HYPERSONIC REGIME THE OPPONENT CAN DETECT IT WITH THE ANTI-DEFENSE SYSTEM BUT CAN NOT STOP IT FROM CAUSING DAMAGE. SO, TO ACHIEVE THE SPEEDS OF THIS LEVEL THERE ARE TWO ENGINES THAT ARE AVAILABLE WHICH CAN WORK IN THIS REGION ARE RAMJET AND SCRAMJET. THE PROBLEM WITH RAMJET STARTS TO OCCUR WHEN MACH NUMBER EXCEEDS 4 AS THE STATIC PRESSURE AT THE INLET BECOMES EQUAL TO THE EXIT PRESSURE. SO, SCRAMJET ENGINE DEALS WITH THIS PROBLEM AS IT NEARLY HAS THE SAME WORKING BUT HERE THE FLOW IS NOT MUCH SLOWED DOWN AS COMPARED TO RAMJET IN THE DIFFUSER BUT IT SUFFERS FROM THE PROBLEMS SUCH AS INLET BUZZ, THERMAL CHOCKING, MIXING OF FUEL AND OXIDIZER, THERMAL HEATING, AND MANY MORE. HERE THE NEW ENGINE IS DEVELOPED ON THE SAME PRINCIPLE AS THE SCRAMJET ENGINE BUT BURNING HAPPENS DUE TO DETONATION INSTEAD OF DEFLAGRATION. THE PROBLEM WITH THE ENGINE STARTS WHEN THE MACH NUMBER BECOMES VARIABLE AND THE INLET GEOMETRY IS FIXED AND THIS LEADS TO INLET SPILLAGE WHICH WILL AFFECT THE THRUST ADVERSELY. SO, HERE ADAPTIVE INLET IS MADE OF SHAPE MEMORY ALLOYS WHICH WILL ENHANCE THE INLET MASS FLOW RATE AS WELL AS THRUST.

Keywords: detonation, ramjet engine, shape memory alloy, ignition delay, shock-boundary layer interaction, eddy dissipation, asymmetric nozzle

Procedia PDF Downloads 88
8744 Models of Copyrights System

Authors: A. G. Matveev

Abstract:

The copyrights system is a combination of different elements. The number, content and the correlation of these elements are different for different legal orders. The models of copyrights systems display this system in terms of the interaction of economic and author's moral rights. Monistic and dualistic models are the most popular ones. The article deals with different points of view on the monism and dualism in copyright system. A specific model of the copyright in Switzerland in the XXth century is analyzed. The evolution of a French dualistic model of copyright is shown. The author believes that one should talk not about one, but rather about a number of dualism forms of copyright system.

Keywords: copyright, exclusive copyright, economic rights, author's moral rights, rights of personality, monistic model, dualistic model

Procedia PDF Downloads 405
8743 Cultural Impact on Fairness Perception of Inequality: A Study on People With Chinese Roots Living in Germany

Authors: Yanping He-Ulbricht, Marc Oliver Rieger

Abstract:

Based on survey data collected from people with Chinese roots living in Germany, this paper examines the impact of assimilation degree and language priming (Chinese or German) on individuals’ perceived fairness of economic and social differences and their attitude towards these. The results show that both the language used and the length of time spent in a foreign culture have a significant impact. Subjects who had spent less than 10 years in Germany demonstrated a higher readiness to accept government intervention in markets with price limits than those who had lived there longer. Subjects who were asked and answered in German perceived the current economic situation as less fair and were also less inclined to accept inequality, even when it leads to a Pareto improvement. While the difference in fairness perception of inequality was a cultural effect, the difference in attitudes towards government intervention was rather a result of learning process. The findings imply that both learning processes of individuals and culture play an important role in perception and preferences regarding social and economic differences.

Keywords: assimilation, bilingualism, cross-cultural comparison, income inequality, language priming, price fairness

Procedia PDF Downloads 74
8742 Gender Difference in the Association between Different Components of the Metabolic Syndrome and Vitamin D Levels in Saudi Patients

Authors: Amal Baalash, Shazia Mukaddam, M. Adel El-Sayed

Abstract:

Background: Several studies have suggested non-skeletal effects of vitamin D and linked its deficiency with features of many chronic conditions. In this study, We aimed to investigate the relationship between vitamin D levels and different components of the metabolic syndrome in male and female Saudi patients. Methods: the study population consisted of 111 patients with metabolic syndrome (71 females and 40 males) aged 37-63 years enrolled from patients attending the internal medicine outpatient clinics of King Fahad Medical City. The parameters for diagnosis of the metabolic syndrome according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) were measured, which included waist circumference, TG, HDL-C, Blood pressure and fasting blood glucose (FBS). The association between each parameter and serum 25-hydroxyvitamin D (25(OH) D) was studied in both male and female patients separately. Results: in male patients, 25(OH) D levels were inversely associated with FBS and TG and positively associated with HDL-C and diastolic blood pressure, With highest association with the HDL-C levels. On the other hand 25(OH) D, Showed no significant association with any of the measured metabolic syndrome parameters in female patients. Conclusion: in Saudi patients with metabolic syndrome, the association between the parameters of metabolic syndrome and the levels of 25 (OH) D is more pronounced in males rather than females.

Keywords: gender, metabolic syndrome, Saudi patients, vitamin D

Procedia PDF Downloads 362
8741 Study on the Effect of Bolt Locking Method on the Deformation of Bipolar Plate in PEMFC

Authors: Tao Chen, ShiHua Liu, JiWei Zhang

Abstract:

Assembly of the proton exchange membrane fuel cells (PEMFC) has a very important influence on its performance and efficiency. The various components of PEMFC stack are usually locked and fixed by bolts. Locking bolt will cause the deformation of the bipolar plate and the other components, which will affect directly the deformation degree of the integral parts of the PEMFC as well as the performance of PEMFC. This paper focuses on the object of three-cell stack of PEMFC. Finite element simulation is used to investigate the deformation of bipolar plate caused by quantity and layout of bolts, bolt locking pressure, and bolt locking sequence, etc. Finally, we made a conclusion that the optimal combination packaging scheme was adopted to assemble the fuel cell stack. The scheme was in use of 3.8 MPa locking pressure imposed on the fuel cell stack, type Ⅱ of four locking bolts and longitudinal locking method. The scheme was obtained by comparatively analyzing the overall displacement contour of PEMFC stack, absolute displacement curve of bipolar plate along the given three paths in the Z direction and the polarization curve of fuel cell. The research results are helpful for the fuel cell stack assembly.

Keywords: bipolar plate, deformation, finite element simulation, fuel cell, locking bolt

Procedia PDF Downloads 396
8740 Locus of Control, Metacognitive Knowledge, Metacognitive Regulation, and Student Performance in an Introductory Economics Course

Authors: Ahmad A. Kader

Abstract:

In the principles of Microeconomics course taught during the Fall Semester 2019, 158out of 179 students participated in the completion of two questionnaires and a survey describing their demographic and academic profiles. The two questionnaires include the 29 items of the Rotter Locus of Control Scale and the 52 items of the Schraw andDennisonMetacognitive Awareness Scale. The 52 items consist of 17 items describing knowledge of cognition and 37 items describing the regulation of cognition. The paper is intended to show the combined influence of locus of control, metacognitive knowledge, and metacognitive regulation on student performance. The survey covers variables that have been tested and recognized in economic education literature, which include GPA, gender, age, course level, race, student classification, whether the course was required or elective, employments, whether a high school economic course was taken, and attendance. Regression results show that of the economic education variables, GPA, classification, whether the course was required or elective, and attendance are the only significant variables in their influence on student grade. Of the educational psychology variables, the regression results show that the locus of control variable has a negative and significant effect, while the metacognitive knowledge variable has a positive and significant effect on student grade. Also, the adjusted R square value increased markedly with the addition of the locus of control, metacognitive knowledge, and metacognitive regulation variables to the regression equation. The t test results also show that students who are internally oriented and are high on the metacognitive knowledge scale significantly outperform students who are externally oriented and are low on the metacognitive knowledge scale. The implication of these results for educators is discussed in the paper.

Keywords: locus of control, metacognitive knowledge, metacognitive regulation, student performance, economic education

Procedia PDF Downloads 106
8739 External Business Environment and Sustainability of Micro, Small and Medium Enterprises in Jigawa State, Nigeria

Authors: Shehu Isyaku

Abstract:

The general objective of the study was to investigate ‘the relationship between the external business environment and the sustainability of micro, small and medium enterprises (MSMEs) in Jigawa state’, Nigeria. Specifically, the study was to examine the relationship between 1) the economic environment, 2) the social environment, 3) the technological environment, and 4) the political environment and the sustainability of MSMEs in Jigawa state, Nigeria. The study was drawn on Resource-Based View (RBV) Theory and Knowledge-Based View (KBV). The study employed a descriptive cross-sectional survey design. A researcher-made questionnaire was used to collect data from the 350 managers/owners who were selected using stratified, purposive and simple random sampling techniques. Data analysis was done using means and standard deviations, factor analysis, Correlation Coefficient, and Pearson Linear Regression analysis. The findings of the study revealed that the sustainability potentials of the managers/owners were rated as high potential (economic, environmental, and social sustainability using 5 5-point Likert scale. Mean ratings of effectiveness of the external business environment were; as highly effective. The results from the Pearson Linear Regression Analysis rejected the hypothesized non-significant effect of the external business environment on the sustainability of MSMEs. Specifically, there is a positive significant relationship between 1) economic environment and sustainability; 2) social environment and sustainability; 3) technological environment and sustainability and political environment and sustainability. The researcher concluded that MSME managers/owners have a high potential for economic, social and environmental sustainability and that all the constructs of the external business environment (economic environment, social environment, technological environment and political environment) have a positive significant relationship with the sustainability of MSMEs. Finally, the researcher recommended that 1) MSME managers/owners need to develop marketing strategies and intelligence systems to accumulate information about the competitors and customers' demands, 2) managers/owners should utilize the customers’ cultural and religious beliefs as an opportunity that should be utilized while formulating business strategies.

Keywords: business environment, sustainability, small and medium enterprises, external business environment

Procedia PDF Downloads 29
8738 Assessment of Environmental and Socio-Economic Impact of Quarring in Ebonyi State South East Nigeria: A Case Study of Umuoghara Quarry Community

Authors: G. Aloh Obianuju, C. Chukwu Kelvin, Henry Aloh

Abstract:

The study was undertaken to assess the environmental and socio-economic impact of quarrying in Umuoghara quarrying community of Ebonyi State, South East Nigeria. Questionnaires were distributed targeting quarry workers and people living within the community; personal interviews with other key informants were also conducted. All these were used as data gathering instruments. The study reveals that there were actually some benefits as well as marked environmental impacts in the community as a result of quarrying activities. Recommendations that can assist in mitigating these adverse impacts were suggested.

Keywords: environment, quarrying, environmental degradation, mitigation

Procedia PDF Downloads 280
8737 Investigating the Influence of Roof Fairing on Aerodynamic Drag of a Bluff Body

Authors: Kushal Kumar Chode

Abstract:

Increase in demand for fuel saving and demand for faster vehicles with decent fuel economy, researchers around the world started investigating in various passive flow control devices to improve the fuel efficiency of vehicles. In this paper, A roof fairing was investigated for reducing the aerodynamic drag of a bluff body. The bluff body considered for this work is Ahmed model with a rake angle of 25deg was and subjected to flow with a velocity of 40m/s having Reynolds number of 2.68million was analysed using a commercial Computational Fluid Dynamic (CFD) code Star CCM+. It was evident that pressure drag is the main source of drag on an Ahmed body from the initial study. Adding a roof fairing has delayed the flow separation and resulted in delaying wake formation, thus improving the pressure in near weak and reducing the wake region. Adding a roof fairing of height and length equal to 1/7H and 1/3L respectively has shown a drag reduction by 9%. However, an optimised fairing, which was obtained by changing height, length and width by 5% increase, recorded a drag reduction close 12%.

Keywords: Ahmed model, aerodynamic drag, passive flow control, roof fairing, wake formation

Procedia PDF Downloads 418
8736 Energy Efficiency Analysis of Discharge Modes of an Adiabatic Compressed Air Energy Storage System

Authors: Shane D. Inder, Mehrdad Khamooshi

Abstract:

Efficient energy storage is a crucial factor in facilitating the uptake of renewable energy resources. Among the many options available for energy storage systems required to balance imbalanced supply and demand cycles, compressed air energy storage (CAES) is a proven technology in grid-scale applications. This paper reviews the current state of micro scale CAES technology and describes a micro-scale advanced adiabatic CAES (A-CAES) system, where heat generated during compression is stored for use in the discharge phase. It will also describe a thermodynamic model, developed in EES (Engineering Equation Solver) to evaluate the performance and critical parameters of the discharge phase of the proposed system. Three configurations are explained including: single turbine without preheater, two turbines with preheaters, and three turbines with preheaters. It is shown that the micro-scale A-CAES is highly dependent upon key parameters including; regulator pressure, air pressure and volume, thermal energy storage temperature and flow rate and the number of turbines. It was found that a micro-scale AA-CAES, when optimized with an appropriate configuration, could deliver energy input to output efficiency of up to 70%.

Keywords: CAES, adiabatic compressed air energy storage, expansion phase, micro generation, thermodynamic

Procedia PDF Downloads 297
8735 Effect of Brewing on the Bioactive Compounds of Coffee

Authors: Ceyda Dadali, Yeşim Elmaci

Abstract:

Coffee was introduced as an economic crop during the fifteenth century; nowadays it is the most important food commodity ranking second after crude oil. Desirable sensory properties make coffee one of the most often consumed and most popular beverages in the world. The coffee preparation method has a significant effect on flavor and composition of coffee brews. Three different extraction methodologies namely decoction, infusion and pressure methods have been used for coffee brew preparation. Each of these methods is related to specific granulation (coffee grind) of coffee powder, water-coffee ratio temperature and brewing time. Coffee is a mixture of 1500 chemical compounds. Chemical composition of coffee highly depends on brewing methods, coffee bean species and roasting time-temperature. Coffee contains a wide number of very important bioactive compounds, such as diterpenes: cafestol and kahweol, alkaloids: caffeine, theobromine and trigonelline, melanoidins, phenolic compounds. The phenolic compounds of coffee include chlorogenic acids (quinyl esters of hidroxycinnamic acids), caffeic, ferulic, p-coumaric acid. In coffee caffeoylquinic acids, feruloylquinic acids and di-caffeoylquinic acids are three main groups of chlorogenic acids constitues 6% -10% of dry weight of coffee. The bioavailability of chlorogenic acids in coffee depends on the absorption and metabolization to biomarkers in individuals. Also, the interaction of coffee polyphenols with other compounds such as dietary proteins affects the biomarkers. Since bioactive composition of coffee depends on brewing methods effect of coffee brewing method on bioactive compounds of coffee will be discussed in this study.

Keywords: bioactive compounds of coffee, biomarkers, coffee brew, effect of brewing

Procedia PDF Downloads 183
8734 The Role of Zakah and Waqf in Poverty Alleviation: A Strategy for West Africa

Authors: Maryam Idris Bakori

Abstract:

The level of poverty in our region (West Africa) is a severe problem. The statistics about it are scary and alarming. For example, Report on Economic and Social Conditions in West Africa by United Nations Economic Commission for Africa gives the following gloomy picture of social conditions in the region: In West Africa, approximately one person in three in the towns, and one in two in the rural areas, cannot afford the expenditure needed to cover their basic needs. The situation has reached emergency proportions and calls for urgent social action (Recent Economic and Social Developments in West Africa and Prospects for 2010). Many different policies and programs to combat the poverty in the region have been embarked upon by the government of various countries in West Africa, but yet the ugly face of poverty persists. However, to explore opportunities and avenues for making positive contributions to national and regional development, this paper sets out to examine the role of two Islamic institutions; Zakah and Waqf, in poverty alleviation and how Islam uses these two institutions among others to eradicate poverty. The paper suggests that the governments of various countries of West Africa should endeavor to integrate Zakah and Waqf into their poverty alleviation programs by borrowing a leaf from some countries in Africa and Asia that have integrated these Islamic institutions into their poverty reduction programs, and they have started to reap the positive result from the policy.

Keywords: waqf, poverty, zakah, Islamic economy, education

Procedia PDF Downloads 375
8733 Relationship between Left Ventricle Position and Hemodynamic Parameters during Cardiopulmonary Resuscitation in a Pig Model

Authors: Hyun Chang Kim, Yong Hun Jung, Kyung Woon Jeung

Abstract:

Background: From the viewpoint of cardiac pump theory, the area of the left ventricle (LV) subjected to compression increases as the LV lies closer to the sternum, possibly resulting in higher blood flow in patients with LV closer to the sternum. However, no study has evaluated LV position during cardiac arrest or its relationship with hemodynamic parameters during cardiopulmonary resuscitation (CPR). The objectives of this study were to determine whether the position of the LV relative to the anterior-posterior axis representing the direction of chest compression shifts during cardiac arrest and to examine the relationship between LV position and hemodynamic parameters during CPR. Methods: Subcostal view echocardiograms were obtained from 15 pigs with the transducer parallel to the long axis of the sternum before inducing ventricular fibrillation (VF) and during cardiac arrest. Computed tomography was performed in three pigs to objectively observe LV position during cardiac arrest. LV position parameters including the shortest distance between the anterior-posterior axis and the mid-point of the LV chamber (DAP-MidLV), the shortest distance between the anterior-posterior axis and the LV apex (DAP-Apex), and the area fraction of the LV located on the right side of the anterior-posterior axis (LVARight/LVATotal) were measured. Results: DAP-MidLV, DAP-Apex, and LVARight/LVATotal decreased progressively during untreated VF and basic life support (BLS), and then increased during advanced cardiovascular life support (ACLS). A repeated measures analysis of variance revealed significant time effects for these parameters. During BLS, the end-tidal carbon dioxide and systolic right atrial pressure were significantly correlated with the LV position parameters. During ACLS, systolic arterial pressure and systolic right atrial pressure were significantly correlated with DAP-MidLV and DAP-Apex. Conclusions: LV position changed significantly during cardiac arrest compared to the pre-arrest baseline. LV position during CPR had significant correlations with hemodynamic parameters.

Keywords: heart arrest, cardiopulmonary resuscitation, heart ventricle, hemodynamics

Procedia PDF Downloads 173
8732 Perception of Predictive Confounders for the Prevalence of Hypertension among Iraqi Population: A Pilot Study

Authors: Zahraa Albasry, Hadeel D. Najim, Anmar Al-Taie

Abstract:

Background: Hypertension is considered as one of the most important causes of cardiovascular complications and one of the leading causes of worldwide mortality. Identifying the potential risk factors associated with this medical health problem plays an important role in minimizing its incidence and related complications. The objective of this study is to explore the prevalence of receptor sensitivity regarding assess and understand the perception of specific predictive confounding factors on the prevalence of hypertension (HT) among a sample of Iraqi population in Baghdad, Iraq. Materials and Methods: A randomized cross sectional study was carried out on 100 adult subjects during their visit to the outpatient clinic at a certain sector of Baghdad Province, Iraq. Demographic, clinical and health records alongside specific screening and laboratory tests of the participants were collected and analyzed to detect the potential of confounding factors on the prevalence of HT. Results: 63% of the study participants suffered from HT, most of them were female patients (P < 0.005). Patients aged between 41-50 years old significantly suffered from HT than other age groups (63.5%, P < 0.001). 88.9% of the participants were obese (P < 0.001) and 47.6% had diabetes with HT. Positive family history and sedentary lifestyle were significantly higher among all hypertensive groups (P < 0.05). High salt and fatty food intake was significantly found among patients suffered from isolated systolic hypertension (ISHT) (P < 0.05). A significant positive correlation between packed cell volume (PCV) and systolic blood pressure (SBP) (r = 0.353, P = 0.048) found among normotensive participants. Among hypertensive patients, a positive significant correlation found between triglycerides (TG) and both SBP (r = 0.484, P = 0.031) and diastolic blood pressure (DBP) (r = 0.463, P = 0.040), while low density lipoprotein-cholesterol (LDL-c) showed a positive significant correlation with DBP (r = 0.443, P = 0.021). Conclusion: The prevalence of HT among Iraqi populations is of major concern. Further consideration is required to detect the impact of potential risk factors and to minimize blood pressure (BP) elevation and reduce the risk of other cardiovascular complications later in life.

Keywords: Correlation, Hypertension, Iraq, Risk factors

Procedia PDF Downloads 121
8731 Numerical Study of Flow Characteristics and Performance of 14-X B Inlet with Blunted Cowl-Lip

Authors: Sergio N. P. Laitón, Paulo G. P. Toro, João F. Martos

Abstract:

A numerical study has been carried out to investigate the flow characteristics and performance of the 14-X B inlet with blunted cowl-lip. The Brazilian aerospace hypersonic vehicle 14-X B is a technology demonstrator of a hypersonic air-breathing propulsion system, based on supersonic combustion ramjet (scramjet). It is designed for Earth's atmospheric flight at Mach number of 6 and an altitude of 30 km. Currently, it is under development in the aerothermodynamics and hypersonic Professor Henry T. Nagamatsu laboratory at Advanced Studies Institute (IEAv). Numerical simulations were conducted at nominal freestream Mach number and altitude for two cowl-lip blunting radius and several angles of attack close to horizontal flight. The results show that the shock interference behavior on the blunted cowl-lip change with the angle of attack and blunted radius. The type VI or V together with III shock interferences are more likely to occur simultaneously at small negative angles of attack. When the inlet operates in positive angles of attack higher to 1, no shock interference occurs, only the bow shock conditions. The results indicate a high air pressure at beginning of the combustor and higher pressure recovery with 2 mm radius and positives angles of attack.

Keywords: blunted cowl-lip, hypersonic inlet, inlet unstart, shock interference

Procedia PDF Downloads 305
8730 Implementation of Renewable Energy Technologies in Rural Africa

Authors: Joseph Levodo, Andy Ford, ISSA Chaer

Abstract:

Africa enjoys some of the best solar radiation levels in the world averaging between 4-6 kWh/m2/day for most of the year and the global economic and political conditions that tend to make African countries more dependent on their own energy resources have caused growing interest in wanting renewable energy based technologies. However to-date, implementation of Modern Energy Technologies in Africa is still very low especially the use of solar conversion technologies. It was initially speculated that the low uptake of solar technology in Africa was associated with the continent’s high poverty levels and limitations in technical capacity as well as awareness. Nonetheless, this is not an academic based speculation and the exact reasons for this low trend in technology adoption are unclear and require further investigation. This paper presents literature review and analysis relating to the techno-economic feasibility of solar photovoltaic power generation in Africa. The literature review would include the following four main categories: design methods, techno-economic feasibility of solar photovoltaic power generation, performance evaluations of various systems, Then it looks at the role of policy and potential future of technological development of photovoltaic (PV) by exploring the impact of alternative policy instruments and technology cost reductions on the financial viability of investing solar photovoltaic (PV) in Africa.

Keywords: Africa Solar Potential, policy, photovoltaic, technologies

Procedia PDF Downloads 533
8729 The Importance of Entrepreneurship for National Economy: Evaluation of Developed and Least Developed Countries

Authors: Adnan Celik

Abstract:

Entrepreneurs are people who attempt to do a business and do not hesitate to do so. They are involved in the production of economic goods and services through factors of production. They also find the financial resources necessary for production and the markets where the production will be evaluated. After all, they create economic values. The main function of the entrepreneur in contemporary societies is to realize innovations. From this point, the power of the modern entrepreneur is based on her/his capacity to innovate and transform his innovations into tangible commercial products. In this context, the concept of an entrepreneur is used to mean the person or persons who constantly innovate. Successful entrepreneurs take on the role of the locomotive in the development of their countries. They support economic development with their activities. In addition to production and marketing activities, it also has important contributions to employment. Along with the development of the country, they also try to make the income distribution more balanced. Especially developed country entrepreneurs intensely perform the following functions; “to produce new goods and services or to increase the quality and quality of known goods and services; ability to develop and apply new production methods; establishing new organizations in the industry; reach new markets; to find new sources from which raw materials and similar materials can be obtained”. Entrepreneurs who fully implement business functions are easier to achieve economic efficiency. Thus, they provide great advantages to the business and the national economy. Successful entrepreneurs are people who make money by creating economic values. These revenues are; on the one hand, it is distributed to individuals in the business as wages, premiums, or dividends; It is also used in the growth of companies. Thus, employees, managers, entrepreneurs and the whole country can benefit greatly. In the least developed countries, the guiding effect of traditional value patterns on individuals' attitudes and behaviors varies depending on the socio-economic characteristics of individuals. It is normal for an entrepreneur with a low level of education, who was brought up in a traditional structure, to behave in accordance with traditional value patterns. In fact, this is the primary problem of all countries in the development effort. The solution to this problem will be possible by giving the necessary importance to the social dimension as well as the technical dimension of development. This study mainly focuses on the importance of entrepreneurship for the national economy. This issue has been handled separately in terms of developed and least developed countries. As a result of the study, entrepreneurship suggestions were made, especially to least developed countries, with the goal of national economy and development.

Keywords: entrepreneur, entrepreneurship, national economy, entrepreneurship in developed and least developed countries

Procedia PDF Downloads 122
8728 Khilafat from Khilafat-e-Rashida: The Rightly Guided the Only Form of Governance to Unite Muslim Countries

Authors: Zoaib Mirza

Abstract:

Half of the Muslim countries in the world have declared Islam the state religion in their constitutions. Yet, none of these countries have implemented authentic Islamic laws in line with the Quran (Holy Book), practices of Prophet Mohammad (P.B.U.H) called the Sunnah, and his four successors known as the Rightly Guided - Khalifa. Since their independence, these countries have adopted different government systems like Democracy, Dictatorship, Republic, Communism, and Monarchy. Instead of benefiting the people, these government systems have put these countries into political, social, and economic crises. These Islamic countries do not have equal representation and membership in worldwide political forums. Western countries lead these forums. Therefore, it is now imperative for the Muslim leaders of all these countries to collaborate, reset, and implement the original Islamic form of government, which led to the prosperity and success of people, including non-Muslims, 1400 years ago. They should unite as one nation under Khalifat, which means establishing the authority of Allah (SWT) and following the divine commandments related to the social, political, and economic systems. As they have declared Islam in their constitution, they should work together to apply the divine framework of the governance revealed by Allah (SWT) and implemented by Prophet Mohammad (P.B.U.H) and his four successors called Khalifas. This paper provides an overview of the downfall and the end of the Khalifat system by 1924, the ways in which the West caused political, social, and economic crises in the Muslim countries, and finally, a summary of the social, political, and economic systems implemented by the Prophet Mohammad (P.B.U.H) and his successors, Khalifas, called the Rightly Guided – Hazrat Abu Bakr (RA), Hazrat Omar (RA), Hazrat Usman (RA), and Hazrat Ali (RA).

Keywords: khalifat, khilafat-e-Rashida, the rightly guided, colonization, capitalism, neocolonization, government systems

Procedia PDF Downloads 102
8727 Blood Flow Estimator of the Left Ventricular Assist Device Based in Look-Up-Table: In vitro Tests

Authors: Tarcisio F. Leao, Bruno Utiyama, Jeison Fonseca, Eduardo Bock, Aron Andrade

Abstract:

This work presents a blood flow estimator based in Look-Up-Table (LUT) for control of Left Ventricular Assist Device (LVAD). This device has been used as bridge to transplantation or as destination therapy to treat patients with heart failure (HF). Destination Therapy application requires a high performance LVAD; thus, a stable control is important to keep adequate interaction between heart and device. LVAD control provides an adequate cardiac output while sustaining an appropriate flow and pressure blood perfusion, also described as physiologic control. Because thrombus formation and system reliability reduction, sensors are not desirable to measure these variables (flow and pressure blood). To achieve this, control systems have been researched to estimate blood flow. LVAD used in the study is composed by blood centrifugal pump, control, and power supply. This technique used pump and actuator (motor) parameters of LVAD, such as speed and electric current. Estimator relates electromechanical torque (motor or actuator) and hydraulic power (blood pump) via LUT. An in vitro Mock Loop was used to evaluate deviations between blood flow estimated and actual. A solution with glycerin (50%) and water was used to simulate the blood viscosity with hematocrit 45%. Tests were carried out with variation hematocrit: 25%, 45% and 58% of hematocrit, or 40%, 50% and 60% of glycerin in water solution, respectively. Test with bovine blood was carried out (42% hematocrit). Mock Loop is composed: reservoir, tubes, pressure and flow sensors, and fluid (or blood), beyond LVAD. Estimator based in LUT is patented, number BR1020160068363, in Brazil. Mean deviation is 0.23 ± 0.07 L/min for mean flow estimated. Larger mean deviation was 0.5 L/min considering hematocrit variation. This estimator achieved deviation adequate for physiologic control implementation. Future works will evaluate flow estimation performance in control system of LVAD.

Keywords: blood pump, flow estimator, left ventricular assist device, look-up-table

Procedia PDF Downloads 169
8726 A Hydrometallurgical Route for the Recovery of Molybdenum from Mo-Co Spent Catalyst

Authors: Bina Gupta, Rashmi Singh, Harshit Mahandra

Abstract:

Molybdenum is a strategic metal and finds applications in petroleum refining, thermocouples, X-ray tubes and in making of steel alloy owing to its high melting temperature and tensile strength. The growing significance and economic value of molybdenum have increased interest in the development of efficient processes aiming its recovery from secondary sources. Main secondary sources of Mo are molybdenum catalysts which are used for hydrodesulphurisation process in petrochemical refineries. The activity of these catalysts gradually decreases with time during the desulphurisation process as the catalysts get contaminated with toxic material and are dumped as waste which leads to environmental issues. In this scenario, recovery of molybdenum from spent catalyst is significant from both economic and environmental point of view. Recently ionic liquids have gained prominence due to their low vapour pressure, high thermal stability, good extraction efficiency and recycling capacity. Present study reports recovery of molybdenum from Mo-Co spent leach liquor using Cyphos IL 102[trihexyl(tetradecyl)phosphonium bromide] as an extractant. Spent catalyst was leached with 3 mol/L HCl and the leach liquor containing Mo-870 ppm, Co-341 ppm, Al-508 ppm and Fe-42 ppm was subjected to extraction step. The effect of extractant concentration on the leach liquor was investigated and almost 85% extraction of Mo was achieved with 0.05 mol/L Cyphos IL 102. Results of stripping studies revealed that 2 mol/L HNO3 can effectively strip 94% of the extracted Mo from the loaded organic phase. McCabe-Thiele diagrams were constructed to determine the number of stages required for quantitative extraction and stripping of molybdenum and were confirmed by counter current simulation studies. According to McCabe-Thiele extraction and stripping isotherms, two stages are required for quantitative extraction and stripping of molybdenum at A/O= 1:1. Around 95.4% extraction of molybdenum was achieved in two stage counter current at A/O= 1:1 with negligible extraction of Co and Al. However, iron was coextracted and removed from the loaded organic phase by scrubbing with 0.01 mol/L HCl. Quantitative stripping (~99.5 %) of molybdenum was achieved with 2.0 mol/L HNO3 in two stages at O/A=1:1. Overall ~95.0% molybdenum with 99 % purity was recovered from Mo-Co spent catalyst. From the strip solution, MoO3 was obtained by crystallization followed by thermal decomposition. The product obtained after thermal decomposition was characterized by XRD, FE-SEM and EDX techniques. XRD peaks of MoO3correspond to molybdite Syn-MoO3 structure. FE-SEM depicts the rod like morphology of synthesized MoO3. EDX analysis of MoO3 shows 1:3 atomic percentage of molybdenum and oxygen. The synthesised MoO3 can find application in gas sensors, electrodes of batteries, display devices, smart windows, lubricants and as catalyst.

Keywords: cyphos IL 102, extraction, Mo-Co spent catalyst, recovery

Procedia PDF Downloads 254
8725 Establishing Community-Based Pro-Biodiversity Enterprise in the Philippines: A Climate Change Adaptation Strategy towards Agro-Biodiversity Conservation and Local Green Economic Development

Authors: Dina Magnaye

Abstract:

In the Philippines, the performance of the agricultural sector is gauged through crop productivity and returns from farm production rather than the biodiversity in the agricultural ecosystem. Agricultural development hinges on the overall goal of increasing productivity through intensive agriculture, monoculture system, utilization of high yielding varieties in plants, and genetic upgrading in animals. This merits an analysis of the role of agro-biodiversity in terms of increasing productivity, food security and economic returns from community-based pro-biodiversity enterprises. These enterprises conserve biodiversity while equitably sharing production income in the utilization of biological resources. The study aims to determine how community-based pro-biodiversity enterprises become instrumental in local climate change adaptation and agro-biodiversity conservation as input to local green economic development planning. It also involves an assessment of the role of agrobiodiversity in terms of increasing productivity, food security and economic returns from community-based pro-biodiversity enterprises. The perceptions of the local community members both in urban and upland rural areas on community-based pro-biodiversity enterprises were evaluated. These served as a basis in developing a planning modality that can be mainstreamed in the management of local green economic enterprises to benefit the environment, provide local income opportunities, conserve species diversity, and sustain environment-friendly farming systems and practices. The interviews conducted with organic farmer-owners, entrepreneur-organic farmers, and organic farm workers revealed that pro-biodiversity enterprise such as organic farming involved the cyclic use of natural resources within the carrying capacity of a farm; recognition of the value of tradition and culture especially in the upland rural area; enhancement of socio-economic capacity; conservation of ecosystems in harmony with nature; and climate change mitigation. The suggested planning modality for community-based pro-biodiversity enterprises for a green economy encompasses four (4) phases to include community resource or capital asset profiling; stakeholder vision development; strategy formulation for sustained enterprises; and monitoring and evaluation.

Keywords: agro-biodiversity, agro-biodiversity conservation, local green economy, organic farming, pro-biodiversity enterprise

Procedia PDF Downloads 349
8724 Production Potential and Economic Returns of Bed Planted Chickpea (Cicer arietinum L.) As Influenced by Different Intercropping Systems

Authors: Priya M. V., Thakar Singh

Abstract:

A field experiment was carried out during the rabi season of 2017 and 2018 to evaluate the productivity and economic viability of bed-planted chickpea-based intercropping systems. The experiment was laid out in a randomized block design consisting of four replications with thirteen treatments. Results showed that sole chickpea recorded the highest seed yield, and it was statistically at par with seed yield obtained under chickpea + oats fodder (2:1), chickpea + oats fodder (4:1), and chickpea + linseed (4:1) intercropping systems. However, oilseed rape and barley as intercrops showed an adverse effect on yield and yield attributes of chickpea. Chickpea + oats fodder in 2:1 row ratio recorded the highest chickpea equivalent yield of 24.07 and 24.77 q/ha during 2017 and 2018, respectively. Higher net returns (Rs. 63098 and 70924/ha) and benefit-cost ratio (1.47 and 1.63) were also recorded in chickpea + oats fodder (2:1) intercropping system over sole chickpea (Rs. 44862 and 53769/ha and 1.21 and 1.41) during both the years. Chickpea + oats fodder (4:1), chickpea + linseed (2:1), and chickpea + linseed (4:1) also recorded significantly higher chickpea equivalent yield, net returns, and benefit-cost ratio as compared to sole chickpea.

Keywords: bed planted chickpea, chickpea equivalent yield, economic returns, intercropping system, productivity

Procedia PDF Downloads 181
8723 Engineering Topology of Ecological Model for Orientation Impact of Sustainability Urban Environments: The Spatial-Economic Modeling

Authors: Moustafa Osman Mohammed

Abstract:

The modeling of a spatial-economic database is crucial in recitation economic network structure to social development. Sustainability within the spatial-economic model gives attention to green businesses to comply with Earth’s Systems. The natural exchange patterns of ecosystems have consistent and periodic cycles to preserve energy and materials flow in systems ecology. When network topology influences formal and informal communication to function in systems ecology, ecosystems are postulated to valence the basic level of spatial sustainable outcome (i.e., project compatibility success). These referred instrumentalities impact various aspects of the second level of spatial sustainable outcomes (i.e., participant social security satisfaction). The sustainability outcomes are modeling composite structure based on a network analysis model to calculate the prosperity of panel databases for efficiency value, from 2005 to 2025. The database is modeling spatial structure to represent state-of-the-art value-orientation impact and corresponding complexity of sustainability issues (e.g., build a consistent database necessary to approach spatial structure; construct the spatial-economic-ecological model; develop a set of sustainability indicators associated with the model; allow quantification of social, economic and environmental impact; use the value-orientation as a set of important sustainability policy measures), and demonstrate spatial structure reliability. The structure of spatial-ecological model is established for management schemes from the perspective pollutants of multiple sources through the input–output criteria. These criteria evaluate the spillover effect to conduct Monte Carlo simulations and sensitivity analysis in a unique spatial structure. The balance within “equilibrium patterns,” such as collective biosphere features, has a composite index of many distributed feedback flows. The following have a dynamic structure related to physical and chemical properties for gradual prolong to incremental patterns. While these spatial structures argue from ecological modeling of resource savings, static loads are not decisive from an artistic/architectural perspective. The model attempts to unify analytic and analogical spatial structure for the development of urban environments in a relational database setting, using optimization software to integrate spatial structure where the process is based on the engineering topology of systems ecology.

Keywords: ecological modeling, spatial structure, orientation impact, composite index, industrial ecology

Procedia PDF Downloads 41
8722 A Case for Strategic Landscape Infrastructure: South Essex Estuary Park

Authors: Alexandra Steed

Abstract:

Alexandra Steed URBAN was commissioned to undertake the South Essex Green and Blue Infrastructure Study (SEGBI) on behalf of the Association of South Essex Local Authorities (ASELA): a partnership of seven neighboring councils within the Thames Estuary. Located on London’s doorstep, the 70,000-hectare region is under extraordinary pressure for regeneration, further development, and economic expansion, yet faces extreme challenges: sea-level rise and inadequate flood defenses, stormwater flooding and threatened infrastructure, loss of internationally important habitats, significant existing community deprivation, and lack of connectivity and access to green space. The brief was to embrace these challenges in the creation of a document that would form a key part of ASELA’s Joint Strategic Framework and feed into local plans and master plans. Thus, helping to tackle climate change, ecological collapse, and social inequity at a regional scale whilst creating a relationship and awareness between urban communities and the surrounding landscapes and nature. The SEGBI project applied a ‘land-based’ methodology, combined with a co-design approach involving numerous stakeholders, to explore how living infrastructure can address these significant issues, reshape future planning and development, and create thriving places for the whole community of life. It comprised three key stages, including Baseline Review; Green and Blue Infrastructure Assessment; and the final Green and Blue Infrastructure Report. The resulting proposals frame an ambitious vision for the delivery of a new regional South Essex Estuary (SEE) Park – 24,000 hectares of protected and connected landscapes. This unified parkland system will drive effective place-shaping and “leveling up” for the most deprived communities while providing large-scale nature recovery and biodiversity net gain. Comprehensive analysis and policy recommendations ensure best practices will be embedded within planning documents and decisions guiding future development. Furthermore, a Natural Capital Account was undertaken as part of the strategy showing the tremendous economic value of the natural assets. This strategy sets a pioneering precedent that demonstrates how the prioritisation of living infrastructure has the capacity to address climate change and ecological collapse, while also supporting sustainable housing, healthier communities, and resilient infrastructures. It was only achievable through a collaborative and cross-boundary approach to strategic planning and growth, with a shared vision of place, and a strong commitment to delivery. With joined-up thinking and a joined-up region, a more impactful plan for South Essex was developed that will lead to numerous environmental, social, and economic benefits across the region, and enhancing the landscape and natural environs on the periphery of one of the largest cities in the world.

Keywords: climate change, green and blue infrastructure, landscape architecture, master planning, regional planning, social equity

Procedia PDF Downloads 82
8721 The Relationship Between Argentina and the IMF (2018-2022), Economic Rationality and Moral Discourse

Authors: German Ricci, Horacio Divito

Abstract:

This article analyses the ethical dimension of the IMF in its relationship with Argentina from the Standby Agreement sanctioned in 2018 to the Extended Fund Facilities of 2023. From the analysis of the statements of the IMF, the appeal of the Agency to an ethic is evidenced and supposedly shared with the borrowing country, in addition to the well-known technical-economic evaluations. The Fund "vindicates" and "punishes" the borrowing country through moral judgment. In the Fund's narratives, the "effort," "commitment," and "work" of the local elite are rewarded. On the other hand, there is a repeated discursive emphasis of the IMF on its permanent intention to "help" Argentina through its collaborative nature. Finally, the emergence of moral prescriptions that question the very being of the debtor country and its representatives is detected when the relationship between local authorities and the IMF is tense.

Keywords: IMF, Argentina, ethics, moral, dependency routine, symbolic power

Procedia PDF Downloads 59
8720 Improving the Efficiency of a High Pressure Turbine by Using Non-Axisymmetric Endwall: A Comparison of Two Optimization Algorithms

Authors: Abdul Rehman, Bo Liu

Abstract:

Axial flow turbines are commonly designed with high loads that generate strong secondary flows and result in high secondary losses. These losses contribute to almost 30% to 50% of the total losses. Non-axisymmetric endwall profiling is one of the passive control technique to reduce the secondary flow loss. In this paper, the non-axisymmetric endwall profile construction and optimization for the stator endwalls are presented to improve the efficiency of a high pressure turbine. The commercial code NUMECA Fine/ Design3D coupled with Fine/Turbo was used for the numerical investigation, design of experiments and the optimization. All the flow simulations were conducted by using steady RANS and Spalart-Allmaras as a turbulence model. The non-axisymmetric endwalls of stator hub and shroud were created by using the perturbation law based on Bezier Curves. Each cut having multiple control points was supposed to be created along the virtual streamlines in the blade channel. For the design of experiments, each sample was arbitrarily generated based on values automatically chosen for the control points defined during parameterization. The Optimization was achieved by using two algorithms i.e. the stochastic algorithm and gradient-based algorithm. For the stochastic algorithm, a genetic algorithm based on the artificial neural network was used as an optimization method in order to achieve the global optimum. The evaluation of the successive design iterations was performed using artificial neural network prior to the flow solver. For the second case, the conjugate gradient algorithm with a three dimensional CFD flow solver was used to systematically vary a free-form parameterization of the endwall. This method is efficient and less time to consume as it requires derivative information of the objective function. The objective function was to maximize the isentropic efficiency of the turbine by keeping the mass flow rate as constant. The performance was quantified by using a multi-objective function. Other than these two classifications of the optimization methods, there were four optimizations cases i.e. the hub only, the shroud only, and the combination of hub and shroud. For the fourth case, the shroud endwall was optimized by using the optimized hub endwall geometry. The hub optimization resulted in an increase in the efficiency due to more homogenous inlet conditions for the rotor. The adverse pressure gradient was reduced but the total pressure loss in the vicinity of the hub was increased. The shroud optimization resulted in an increase in efficiency, total pressure loss and entropy were reduced. The combination of hub and shroud did not show overwhelming results which were achieved for the individual cases of the hub and the shroud. This may be caused by fact that there were too many control variables. The fourth case of optimization showed the best result because optimized hub was used as an initial geometry to optimize the shroud. The efficiency was increased more than the individual cases of optimization with a mass flow rate equal to the baseline design of the turbine. The results of artificial neural network and conjugate gradient method were compared.

Keywords: artificial neural network, axial turbine, conjugate gradient method, non-axisymmetric endwall, optimization

Procedia PDF Downloads 216