Search results for: water and sewerage charge rate.
3035 Zero Voltage Switched Full Bridge Converters for the Battery Charger of Electric Vehicle
Authors: Rizwan Ullah, Abdar Ali, Zahid Ullah
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This paper illustrates the study of three isolated zero voltage switched (ZVS) PWM full bridge (FB) converters to charge the high voltage battery in the charger of electric vehicle (EV). EV battery chargers have several challenges such as high efficiency, high reliability, low cost, isolation, and high power density. The cost of magnetic and filter components in the battery charger is reduced when switching frequency is increased. The increase in the switching frequency increases switching losses. ZVS is used to reduce switching losses and to operate the converter in the battery charger at high frequency. The performance of each of the three converters is evaluated on the basis of ZVS range, dead times of the switches, conduction losses of switches, circulating current stress, circulating energy, duty cycle loss, and efficiency. The limitations and merits of each PWM FB converter are reviewed. The converter with broader ZVS range, high efficiency and low switch stresses is selected for battery charger applications in EV.Keywords: Electric vehicle, PWM FB converter, zero voltage switching, circulating energy, duty cycle loss, battery charger.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24123034 Exploring the Applicability of a Rapid Health Assessment in India
Authors: Claudia Carbajal, Jija Dutt, Smriti Pahwa, Sumukhi Vaid, Karishma Vats
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ASER Centre, the research and assessment arm of Pratham Education Foundation sees measurement as the first stage of action. ASER uses primary research to push and give empirical foundations to policy discussions at a multitude of levels. At a household level, common citizens use a simple assessment (a floor-level test) to measure learning across rural India. This paper presents the evidence on the applicability of an ASER approach to the health sector. A citizen-led assessment was designed and executed that collected information from young mothers with children up to a year of age. The pilot assessments were rolled-out in two different models: Paid surveyors and student volunteers. The survey covered three geographic areas: 1,239 children in the Jaipur District of Rajasthan, 2,086 in the Rae Bareli District of Uttar Pradesh, and 593 children in the Bhuj Block in Gujarat. The survey tool was designed to study knowledge of health-related issues, daily practices followed by young mothers and access to relevant services and programs. It provides insights on behaviors related to infant and young child feeding practices, child and maternal nutrition and supplementation, water and sanitation, and health services. Moreover, the survey studies the reasons behind behaviors giving policy-makers actionable pathways to improve implementation of social sector programs. Although data on health outcomes are available, this approach could provide a rapid annual assessment of health issues with indicators that are easy to understand and act upon so that measurements do not become an exclusive domain of experts. The results give many insights into early childhood health behaviors and challenges. Around 98% of children are breastfed, and approximately half are not exclusively breastfed (for the first 6 months). Government established diet diversity guidelines are met for less than 1 out of 10 children. Although most households are satisfied with the quality of drinking water, most tested households had contaminated water.
Keywords: Citizen-led assessment, infant and young children feeding, maternal nutrition, rapid health assessment supplementation, water and sanitation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17683033 Assessing the Suitability of South African Waste Foundry Sand as an Additive in Clay Masonry Products
Authors: Nthabiseng Portia Mahumapelo, Andre van Niekerk, Ndabenhle Sosibo, Nirdesh Singh
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The foundry industry generates large quantities of solid waste in the form of waste foundry sand. The ever-increasing quantities of this type of industrial waste put pressure on land-filling space and its proper management has become a global concern. The South African foundry industry is not different when it comes to this solid waste generation. Utilizing the foundry waste sand in other applications has become an attractive avenue to deal with this waste stream. In the present paper, an evaluation was done on the suitability of foundry waste sand as an additive in clay masonry products. Purchased clay was added to the foundry waste sand sample in a 50/50 ratio. The mixture was named FC sample. The FC sample was mixed with water in a pan mixer until the mixture was consistent and suitable for extrusion. The FC sample was extruded and cut into briquettes. Water absorption, shrinkage and modulus of rupture tests were conducted on the resultant briquettes. Foundry waste sand and FC samples were respectively characterized mineralogically using X-Ray Diffraction, and the major and trace elements were determined using Inductively Coupled Plasma Optical Emission Spectroscopy. Adding purchased clay to the foundry waste sand positively influenced the workability of the test sample. Another positive characteristic was the low linear shrinkage, which indicated that products manufactured from the FC sample would not be susceptible to cracking. The water absorption values were acceptable and the unfired and fired strength values of the briquette’s samples were acceptable. In conclusion, tests showed that foundry waste sand can be used as an additive in masonry clay bricks, provided it is blended with good quality clay.
Keywords: Foundry waste sand, masonry clay bricks, modulus of rupture, shrinkage.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6453032 LEED Empirical Evidence in Northern and Southern Europe
Authors: Svetlana Pushkar
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The Leadership in Energy and Environmental Design (LEED) green building rating system is recognized in Europe. LEED uses regional priority (RP) points that are adapted to different environmental conditions. However, the appropriateness of the RP points is still a controversial question. To clarify this issue, two different parts of Europe: northern Europe (Finland and Sweden) and southern Europe (Turkey and Spain) were considered. Similarities and differences in the performances of LEED 2009-new construction (LEED-NC 2009) in these four countries were analyzed. It was found that LEED-NC 2009 performances in northern and southern parts of Europe in terms of Sustainable Sites (SS), Water Efficiency (WE), Materials and Resources (MR), and Indoor Environmental Quality (EQ) were similar, whereas in Energy and Atmosphere (EA), their performances were different. WE and SS revealed high performances (70-100%); EA and EQ demonstrated intermediate performance (40-60%); and MR displayed low performance (20-40%). It should be recommended introducing the following new RP points: for Turkey - water-related points and for all four observed countries - green power-related points for improving the LEED adaptation in Europe.
Keywords: Green building, Europe, LEED, regional priority points.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8103031 Effect of Gibberellic Acid and 2,4- Dichlorophenoxyacetic Acid on Fruit Development and Fruit Quality of Wax Apple
Authors: Nguyen Minh Tuan, Yen Chung–Ruey
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This study was conducted to evaluate the effects of gibberellic acid and 2,4- dichlorophenoxyacetic acid on flower number, fruit growth and fruit quality of wax apple. GA3 and 2,4-D were applied at small bud and petal fall stage. Number of flower, fruit set, fruit drop, fruit crack, fruit growth and fruit quality were recorded. Results indicated that spraying with 10 ppm GA3 had the best results in number of flower. GA3 spray at 30 ppm gave the faster rate of fruit growth than the other treatments. Fruit set, fruit size as well as fruit weight markedly improved by spraying 30 ppm GA3, followed by 10 ppm GA3 compared to untreated control. Moreover, spray GA3 at 30 ppm was the most effective and increased total soluble solids, reduced titratable acidity and fruit drop. On the other hand, it was noticed that with 10 ppm 2,4-D application also enhanced the fruit growth rate, improved physiological and biochemical characters of fruit compared to untreated control. It was concluded that both GA3 and 2,4-D spray have positive effects on fruit development, reduced fruit drop, fruit crack and improved fruit quality of wax apple under field conditions.Keywords: Wax apple, GA3, 2, 4-D, fruit growth, fruit quality.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 54343030 Characterization of Gamma Irradiated PVDF and PVDF/Graphene Oxide Composites by Spectroscopic Techniques
Authors: Juliana V. Pereira, Adriana S. M. Batista, Jefferson P. Nascimento, Clascídia A. Furtado, Luiz O. Faria
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The combination of the properties of graphene oxide (OG) and PVDF homopolymer makes their combined composite materials as multifunctional systems with great potential. Knowledge of the molecular structure is essential for better use. In this work, the degradation of PVDF polymer exposed to gamma irradiation in oxygen atmosphere in high dose rate has been studied and compared to degradation of PVDF/OG composites. The samples were irradiated with a Co-60 source at constant dose rate, with doses ranging from 100 kGy to 1,000 kGy. In FTIR data shown that the formation of oxidation products was at the both samples with formation of carbonyl and hydroxyl groups amongst the most prevalent products in the pure PVDF samples. In the other hand, the composites samples exhibit less presence of degradation products with predominant formation of carbonyl groups, these results also seen in the UV-Vis analysis. The results show that the samples of composites may have greater resistance to the irradiation process, since they have less degradation products than pure PVDF samples seen by spectroscopic techniques.Keywords: Gamma irradiation, PVDF, PVDF/OG composites, spectroscopic techniques.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21193029 Online Monitoring Rheological Property of Polymer Melt during Injection Molding
Authors: Chung-Chih Lin, Chien-Liang Wu
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The detection of the polymer melt state during manufacture process is regarded as an efficient way to control the molded part quality in advance. Online monitoring rheological property of polymer melt during processing procedure provides an approach to understand the melt state immediately. Rheological property reflects the polymer melt state at different processing parameters and is very important in injection molding process especially. An approach that demonstrates how to calculate rheological property of polymer melt through in-process measurement, using injection molding as an example, is proposed in this study. The system consists of two sensors and a data acquisition module can process the measured data, which are used for the calculation of rheological properties of polymer melt. The rheological properties of polymer melt discussed in this study include shear rate and viscosity which are investigated with respect to injection speed and melt temperature. The results show that the effect of injection speed on the rheological properties is apparent, especially for high melt temperature and should be considered for precision molding process.
Keywords: Injection molding, melt viscosity, shear rate, monitoring.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27953028 Designing Pictogram for Food Portion Size
Authors: Y.C. Liu, S.J. Lu, Y.C. Weng, H. Su
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The objective of this paper is to investigate a new approach based on the idea of pictograms for food portion size. This approach adopts the model of the United States Pharmacopeia- Drug Information (USP-DI). The representation of each food portion size composed of three parts: frame, the connotation of dietary portion sizes and layout. To investigate users- comprehension based on this approach, two experiments were conducted, included 122 Taiwanese people, 60 male and 62 female with ages between 16 and 64 (divided into age groups of 16-30, 31-45 and 46-64). In Experiment 1, the mean correcting rate of the understanding level of food items is 48.54% (S.D.= 95.08) and the mean response time 2.89sec (S.D.=2.14). The difference on the correct rates for different age groups is significant (P*=0.00<0.05). In Experiment 2, the correcting rate of selecting the right life-size measurement aid is 65.02% (S.D.=21.31). The result showed the potential of the approach for certain food potion sizes. Issues raised for discussions including comprehension on numerous food varieties in an open environment, selection of photograph or drawing, reasons of different correcting rates for the measurement aid. This research also could be used for those interested in systematic and pictorial representation of dietary portion size information.Keywords: Comprehension, Food Portion Size, Model of DietaryInformation, Pictogram Design, USP-DI.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19273027 The Smoke Suppression Effect of Copper Oxideon the Epoxy Resin/Intumescent Flame Retardant/Titanate Couple Agent System
Authors: Zhiping Wu, Meiqin Chen, Haikuan Yang, Yunchu Hu
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Fire disaster is the major factor to endanger the public and environmental safety. People lost their life during fire disaster mainly be attributed to the dense smoke and toxic gas under combustion, which hinder the escape of people and the rescue of firefighters under fire disaster. The smoke suppression effect of several transitional metals oxide on the epoxy resin treated with intumescent flame retardant and titanate couple agent (EP/IFR/Titanate) system have been investigated. The results showed manganese dioxide has great effect on reducing the smoke density rate (SDR) of EP/IFR/Titanate system; however it has little effect to reduce the maximum smoke density (MSD) of EP/IFR/Titanate system. Copper oxide can decrease the maximum smoke density (MSD) and smoke density rate of EP/IFR/Titanate system substantially. The MSD and SDR of EP/IFR/Titanate system can reduce 20.3% and 39.1% respectively when 2% of copper oxide is introduced.Keywords: copper oxide, epoxy resin, intumescent flameretardant, smoke suppression.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26873026 Application of Unstructured Mesh Modeling in Evolving SGE of an Airport at the Confluence of Multiple Rivers in a Macro Tidal Region
Authors: A. A. Purohit, M. M. Vaidya, M. D. Kudale
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Among the various developing countries in the world like China, Malaysia, Korea etc., India is also developing its infrastructures in the form of Road/Rail/Airports and Waterborne facilities at an exponential rate. Mumbai, the financial epicenter of India is overcrowded and to relieve the pressure of congestion, Navi Mumbai suburb is being developed on the east bank of Thane creek near Mumbai. The government due to limited space at existing Mumbai Airports (domestic and international) to cater for the future demand of airborne traffic, proposes to build a new international airport near Panvel at Navi Mumbai. Considering the precedence of extreme rainfall on 26th July 2005 and nearby townships being in a low-lying area, wherein new airport is proposed, it is inevitable to study this complex confluence area from a hydrodynamic consideration under both tidal and extreme events (predicted discharge hydrographs), to avoid inundation of the surrounding due to the proposed airport reclamation (1160 hectares) and to determine the safe grade elevation (SGE). The model studies conducted using the application of unstructured mesh to simulate the Panvel estuarine area (93 km2), calibration, validation of a model for hydraulic field measurements and determine the maxima water levels around the airport for various extreme hydrodynamic events, namely the simultaneous occurrence of highest tide from the Arabian Sea and peak flood discharges (Probable Maximum Precipitation and 26th July 2005) from five rivers, the Gadhi, Kalundri, Taloja, Kasadi and Ulwe, meeting at the proposed airport area revealed that: (a) The Ulwe River flowing beneath the proposed airport needs to be diverted. The 120m wide proposed Ulwe diversion channel having a wider base width of 200 m at SH-54 Bridge on the Ulwe River along with the removal of the existing bund in Moha Creek is inevitable to keep the SGE of the airport to a minimum. (b) The clear waterway of 80 m at SH-54 Bridge (Ulwe River) and 120 m at Amra Marg Bridge near Moha Creek is also essential for the Ulwe diversion and (c) The river bank protection works on the right bank of Gadhi River between the NH-4B and SH-54 bridges as well as upstream of the Ulwe River diversion channel are essential to avoid inundation of low lying areas. The maxima water levels predicted around the airport keeps SGE to a minimum of 11m with respect to Chart datum of Ulwe Bundar and thus development is not only technologically-economically feasible but also sustainable. The unstructured mesh modeling is a promising tool to simulate complex extreme hydrodynamic events and provides a reliable solution to evolve optimal SGE of airport.
Keywords: Airport, hydrodynamics, hydrographs, safe grade elevation, tides.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9833025 Study on Changes of Land Use impacting the Process of Urbanization, by Using Landsat Data in African Regions: A Case Study in Kigali, Rwanda
Authors: Delphine Mukaneza, Lin Qiao, Wang Pengxin, Li Yan, Chen Yingyi
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Human activities on land use make the land-cover gradually change or transit. In this study, we examined the use of Landsat TM data to detect the land use change of Kigali between 1987 and 2009 using remote sensing techniques and analysis of data using ENVI and ArcGIS, a GIS software. Six different categories of land use were distinguished: bare soil, built up land, wetland, water, vegetation, and others. With remote sensing techniques, we analyzed land use data in 1987, 1999 and 2009, changed areas were found and a dynamic situation of land use in Kigali city was found during the 22 years studied. According to relevant Landsat data, the research focused on land use change in accordance with the role of remote sensing in the process of urbanization. The result of the work has shown the rapid increase of built up land between 1987 and 1999 and a big decrease of vegetation caused by the rebuild of the city after the 1994 genocide, while in the period of 1999 to 2009 there was a reduction in built up land and vegetation, after the authority of Kigali city established, a Master Plan where all constructions which were not in the range of the master Plan were destroyed. Rwanda's capital, Kigali City, through the expansion of the urban area, it is increasing the internal employment rate and attracts business investors and the service sector to improve their economy, which will increase the population growth and provide a better life. The overall planning of the city of Kigali considers the environment, land use, infrastructure, cultural and socio-economic factors, the economic development and population forecast, urban development, and constraints specification. To achieve the above purpose, the Government has set for the overall planning of city Kigali, different stages of the detailed description of the design, strategy and action plan that would guide Kigali planners and members of the public in the future to have more detailed regional plans and practical measures. Thus, land use change is significantly the performance of Kigali active human area, which plays an important role for the country to take certain decisions. Another area to take into account is the natural situation of Kigali city. Agriculture in the region does not occupy a dominant position, and with the population growth and socio-economic development, the construction area will gradually rise and speed up the process of urbanization. Thus, as a developing country, Rwanda's population continues to grow and there is low rate of utilization of land, where urbanization remains low. As mentioned earlier, the 1994 genocide massacres, population growth and urbanization processes, have been the factors driving the dramatic changes in land use. The focus on further research would be on analysis of Rwanda’s natural resources, social and economic factors that could be, the driving force of land use change.Keywords: Land use change, urbanization, Kigali City, Landsat.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10453024 Mathematical Modeling to Predict Surface Roughness in CNC Milling
Authors: Ab. Rashid M.F.F., Gan S.Y., Muhammad N.Y.
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Surface roughness (Ra) is one of the most important requirements in machining process. In order to obtain better surface roughness, the proper setting of cutting parameters is crucial before the process take place. This research presents the development of mathematical model for surface roughness prediction before milling process in order to evaluate the fitness of machining parameters; spindle speed, feed rate and depth of cut. 84 samples were run in this study by using FANUC CNC Milling α-Τ14ιE. Those samples were randomly divided into two data sets- the training sets (m=60) and testing sets(m=24). ANOVA analysis showed that at least one of the population regression coefficients was not zero. Multiple Regression Method was used to determine the correlation between a criterion variable and a combination of predictor variables. It was established that the surface roughness is most influenced by the feed rate. By using Multiple Regression Method equation, the average percentage deviation of the testing set was 9.8% and 9.7% for training data set. This showed that the statistical model could predict the surface roughness with about 90.2% accuracy of the testing data set and 90.3% accuracy of the training data set.
Keywords: Surface roughness, regression analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21173023 Development of an Impregnated Diamond Bit with an Improved Rate of Penetration
Authors: Tim Dunne, Weicheng Li, Chris Cheng, Qi Peng
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Deeper petroleum reservoirs are more challenging to exploit due to the high hardness and abrasive characteristics of the formations. A cutting structure that consists of particulate diamond impregnated in a supporting matrix is found to be effective. Diamond impregnated bits are favored in these applications due to the higher thermal stability of the matrix material. The diamond particles scour or abrade away concentric grooves while the rock formation adjacent to the grooves is fractured and removed. The matrix material supporting the diamond will wear away, leaving the superficial dull diamonds to fall out. The matrix material wear will expose other embedded intact sharp diamonds to continue the operation. Minimizing the erosion effect on the matrix is an important design consideration, as the life of the bit can be extended by preventing early diamond pull-out. A careful balancing of the key parameters, such as diamond concentration, tungsten carbide and metal binder must be considered during development. Described herein is the design of experiment for developing and lab testing 8 unique samples. ASTM B611 wear testing was performed to benchmark the material performance against baseline products, with further scanning electron microscopy and microhardness evaluations. The recipe S5 with diamond 25/35 mesh size, narrow size distribution, high concentration blended with fine tungsten carbide and Co-Cu-Fe-P metal binder has the best performance, which shows 19% improvement in the ASTM B611 wear test compared with the reference material. In the field trial, the rate of penetration (ROP) is measured as 15 m/h, compared to 9.5, 7.8, and 6.8 m/h of other commercial impregnated bits in the same formation. A second round of optimizing recipe S5 for a higher wear resistance is further reported.
Keywords: Diamond containing material, grit hot press insert, impregnated diamond, insert, rate of penetration, ultrahard formation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3533022 Combined Automatic Speech Recognition and Machine Translation in Business Correspondence Domain for English-Croatian
Authors: Sanja Seljan, Ivan Dunđer
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The paper presents combined automatic speech recognition (ASR) of English and machine translation (MT) for English and Croatian and Croatian-English language pairs in the domain of business correspondence. The first part presents results of training the ASR commercial system on English data sets, enriched by error analysis. The second part presents results of machine translation performed by free online tool for English and Croatian and Croatian-English language pairs. Human evaluation in terms of usability is conducted and internal consistency calculated by Cronbach's alpha coefficient, enriched by error analysis. Automatic evaluation is performed by WER (Word Error Rate) and PER (Position-independent word Error Rate) metrics, followed by investigation of Pearson’s correlation with human evaluation.
Keywords: Automatic machine translation, integrated language technologies, quality evaluation, speech recognition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29023021 Performance Evaluation of Intelligent Controllers for AGC in Thermal Systems
Authors: Muhammad Muhsin, Abhishek Mishra, Shreyansh Vishwakarma, K. Dasaratha Babu, Anudevi Samuel
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In an interconnected power system, any sudden small load perturbation in any of the interconnected areas causes the deviation of the area frequencies, the tie line power and voltage deviation at the generator terminals. This paper deals with the study of performance of intelligent Fuzzy Logic controllers coupled with Conventional Controllers (PI and PID) for Load Frequency Control. For analysis, an isolated single area and interconnected two area thermal power systems with and without generation rate constraints (GRC) have been considered. The studies have been performed with conventional PI and PID controllers and their performance has been compared with intelligent fuzzy controllers. It can be demonstrated that these controllers can successfully bring back the excursions in area frequencies and tie line powers within acceptable limits in smaller time periods and with lesser transients as compared to the performance of conventional controllers under same load disturbance conditions. The simulations in MATLAB have been used for comparative studies.
Keywords: Area Control Error, Fuzzy Logic, Generation rate constraint, Load Frequency, Tie line Power.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24473020 Retarding Potential Analyzer Design and Result Analysis for Ion Energy Distribution Measurement of the Thruster Plume in the Laboratory
Authors: Ma Ya-li, Tang Fu-jun, Xue Yu-xiong, Chen Yi-feng, Gao Xin, Wang Yi, Tian Kai, Yan Ze-dong
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Plasma plume will be produced and arrive at spacecraft when the electric thruster operates on orbit. It-s important to characterize the thruster plasma parameters because the plume has significant effects or hazards on spacecraft sub-systems and parts. Through the ground test data of the desired parameters, the major characteristics of the thruster plume will be achieved. Also it is very important for optimizing design of Ion thruster. Retarding Potential Analyzer (RPA) is an effective instrument for plasma ion energy per unit charge distribution measurement. Special RPA should be designed according to certain plume plasma parameters range and feature. In this paper, major principles usable for good RPA design are discussed carefully. Conform to these principles, a four-grid planar electrostatic energy analyzer RPA was designed to avoid false data, and details were discussed including construction, materials, aperture diameter and so on. At the same time, it was designed more suitable for credible and long-duration measurements in the laboratory. In the end, RPA measurement results in the laboratory were given and discussed.
Keywords: Thruster plume ion energy distributions, retarding potential analyzer, ground test.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 39873019 In vitro Study of Antibacterial Activity of Cymbopogon citratus
Authors: C.K. Hindumathy
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Alcohol and water extracts of Cymbopogon citratus was investigated for anti-bacterial properties and phytochemical constituents. The extract was screened against four gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus vulgaris) and two grampositive bacteria Bacillus subtilis and Staphylococcus aureus at four different concentrations (1:1, 1:5, 1:10 and 1:20) using disc diffusion method. The antibacterial examination was by disc diffusion techniques, while the photochemical constituents were investigated using standard chemical methods. Results showed that the extracts inhibited the growth of standard and local strains of the organisms used. The treatments were significantly different (P = 0.05). The minimum inhibitory concentration of the extracts against the tested microorganisms ranged between 150mg/ml and 50mg/ml. The alcohol extracts were found to be generally more effective than the water extract. The photochemical analysis revealed the presence of alkaloids and phenol but absence of cardiac and cyanogenic glycosides. The presence of alkaloid and phenols were inferred as being responsible for the anti-bacterial properties of the extracts.Keywords: Cymbopogon citratus; gram negative and grampositive
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 48333018 Optimising Data Transmission in Heterogeneous Sensor Networks
Authors: M. Hammerton, J. Trevathan, T. Myers, W. Read
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The transfer rate of messages in distributed sensor network applications is a critical factor in a system's performance. The Sensor Abstraction Layer (SAL) is one such system. SAL is a middleware integration platform for abstracting sensor specific technology in order to integrate heterogeneous types of sensors in a network. SAL uses Java Remote Method Invocation (RMI) as its connection method, which has unsatisfying transfer rates, especially for streaming data. This paper analyses different connection methods to optimize data transmission in SAL by replacing RMI. Our results show that the most promising Java-based connections were frameworks for Java New Input/Output (NIO) including Apache MINA, JBoss Netty, and xSocket. A test environment was implemented to evaluate each respective framework based on transfer rate, resource usage, and scalability. Test results showed the most suitable connection method to improve data transmission in SAL JBoss Netty as it provides a performance enhancement of 68%.
Keywords: Wireless sensor networks, remote method invocation, transmission time.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20283017 Application of Biometrics to Obtain High Entropy Cryptographic Keys
Authors: Sanjay Kanade, Danielle Camara, Dijana Petrovska-Delacretaz, Bernadette Dorizzi
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In this paper, a two factor scheme is proposed to generate cryptographic keys directly from biometric data, which unlike passwords, are strongly bound to the user. Hash value of the reference iris code is used as a cryptographic key and its length depends only on the hash function, being independent of any other parameter. The entropy of such keys is 94 bits, which is much higher than any other comparable system. The most important and distinct feature of this scheme is that it regenerates the reference iris code by providing a genuine iris sample and the correct user password. Since iris codes obtained from two images of the same eye are not exactly the same, error correcting codes (Hadamard code and Reed-Solomon code) are used to deal with the variability. The scheme proposed here can be used to provide keys for a cryptographic system and/or for user authentication. The performance of this system is evaluated on two publicly available databases for iris biometrics namely CBS and ICE databases. The operating point of the system (values of False Acceptance Rate (FAR) and False Rejection Rate (FRR)) can be set by properly selecting the error correction capacity (ts) of the Reed- Solomon codes, e.g., on the ICE database, at ts = 15, FAR is 0.096% and FRR is 0.76%. Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20823016 Drying of Papaya (Carica papaya L.) Using a Microwave-vacuum Dryer
Authors: Kraipat Cheenkachorn, Piyawat Jintanatham, Sarun Rattanaprapa
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In present work, drying characteristics of fresh papaya (Carica papaya L.) was studied to understand the dehydration process and its behavior. Drying experiments were carried out by a laboratory scaled microwave-vacuum oven. The parameters affecting drying characteristics including operating modes (continuous, pulsed), microwave power (400 and 800 W), and vacuum pressure (20, 30, and 40 cmHg) were investigated. For pulsed mode, two levels of power-off time (60 and 120 s) were used while the power-on time was fixed at 60 s and the vacuum pressure was fixed at 40 cmHg. For both operating modes, the effects of drying conditions on drying time, drying rate, and effective diffusivity were investigated. The results showed high microwave power, high vacuum, and pulsed mode of 60 s-on/60 s-off favored drying rate as shown by the shorten drying time and increased effective diffusivity. The drying characteristics were then described by Page-s model, which showed a good agreement with experimental data.
Keywords: papaya, microwave-vacuum drying, effective diffusivity, Page's model
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28493015 Numerical Study of Developing Laminar Forced Convection Flow of Water/CuO Nanofluid in a Circular Tube with a 180 Degrees Curve
Authors: Hamed K. Arzani, Hamid K. Arzani, S.N. Kazi, A. Badarudin
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Numerical investigation into convective heat transfer of CuO-Water based nanofluid in a pipe with return bend under laminar flow conditions has been done. The impacts of Reynolds number and the volume concentration of nanoparticles on the flow and the convective heat transfer behaviour are investigated. The results indicate that the increase in Reynolds number leads to the enhancement of average Nusselt number, and the increase in specific heat in the presence of the nanofluid results in improvement in heat transfer. Also, the presence of the secondary flow in the curve plays a key role in increasing the average Nusselt number and it appears higher than the inlet and outlet tubes. However, the pressure drop curve increases significantly in the tubes with the increase in nanoparticles concentration.Keywords: Laminar forced convection, nanofluid, curve, return bend, CFD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12773014 Determining of Threshold Levels of Burst by Burst AQAM/CDMA in Slow Rayleigh Fading Environments
Authors: F. Nejadebrahimi, M. ArdebiliPour
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In this paper, we are going to determine the threshold levels of adaptive modulation in a burst by burst CDMA system by a suboptimum method so that the above method attempts to increase the average bit per symbol (BPS) rate of transceiver system by switching between the different modulation modes in variable channel condition. In this method, we choose the minimum values of average bit error rate (BER) and maximum values of average BPS on different values of average channel signal to noise ratio (SNR) and then calculate the relative threshold levels of them, so that when the instantaneous SNR increases, a higher order modulation be employed for increasing throughput and vise-versa when the instantaneous SNR decreases, a lower order modulation be employed for improvement of BER. In transmission step, by this adaptive modulation method, in according to comparison between obtained estimation of pilot symbols and a set of above suboptimum threshold levels, above system chooses one of states no transmission, BPSK, 4QAM and square 16QAM for modulation of data. The expected channel in this paper is a slow Rayleigh fading.
Keywords: AQAM, burst, BER, BPS, CDMA, threshold.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15183013 The Contribution of Growth Rate to the Pathogenicity of Candida spp.
Authors: Shu-Ying Marissa Pang, Stephen Tristram, Simon Brown
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Fungal infections are becoming more common and the range of susceptible individuals has expanded. While Candida albicans remains the most common infective species, other Candida spp. are becoming increasingly significant. In a range of large-scale studies of candidaemia between 1999 and 2006, about 52% of 9717 cases involved C. albicans, about 30% involved either C. glabrata or C. parapsilosis and less than 15% involved C. tropicalis, C. krusei or C. guilliermondii. However, the probability of mortality within 30 days of infection with a particular species was at least 40% for C. tropicalis, C. albicans, C. glabrata and C. krusei and only 22% for C. parapsilopsis. Clinical isolates of Candida spp. grew at rates ranging from 1.65 h-1 to 4.9 h-1. Three species (C. krusei, C. albicans and C. glabrata) had relatively high growth rates (μm > 4 h-1), C. tropicalis and C. dubliniensis grew moderately quickly (Ôëê 3 h-1) and C. parapsilosis and C. guilliermondii grew slowly (< 2 h-1). Based on these data, the log of the odds of mortality within 30 days of diagnosis was linearly related to μm. From this the underlying probability of mortality is 0.13 (95% CI: 0.10-0.17) and it increases by about 0.09 ± 0.02 for each unit increase in μm. Given that the overall crude mortality is about 0.36, the growth of Candida spp. approximately doubles the rate, consistent with the results of larger case-matched studies of candidaemia.Keywords: Candida spp., candidiasis, growth, pathogenicity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15833012 Effect of Tube Materials and Special Coating on Coke Deposition in the Steam Cracking of Hydrocarbons
Authors: A. Niaei, D. Salari , N. Daneshvar, A. Chamandeh, R. Nabavi
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The steam cracking reactions are always accompanied with the formation of coke which deposits on the walls of the tubular reactors. The investigation has attempted to control catalytic coking by the applying aluminum, zinc and ceramic coating like aluminum-magnesium by thermal spray and pack cementation method. Rate of coke formation during steam cracking of naphtha has been investigated both for uncoated stainless steel (with different alloys) and metal coating constructed with thermal Spray and pack cementation method with metal powders of Aluminum, Aluminum-Magnesium, zinc, silicon, nickel and chromium. The results of the study show that passivating the surface of SS321 with a coating of Aluminum and Aluminum-Magnesium can significantly reduce the rate of coke deposition during naphtha pyrolysis. SEM and EDAX techniques (Philips XL Series) were used to examine the coke deposits formed by the metal-hydrocarbon reactions. Our objective was to separate the different stages by identifying the characteristic morphologies.Keywords: Steam Cracking, Pyrolysis, Coke deposition, thermalspray, Pack Cementation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29963011 Viscosity Model for Predicting the Power Output from Ocean Salinity and Temperature Energy Conversion System (OSTEC) Part 1: Theoretical Formulation
Authors: Ag. S. Abd. Hamid, S. K. Lee, J. Dayou, R. Yusoff, F. Sulaiman
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The mixture between two fluids of different salinity has been proven to capable of producing electricity in an ocean salinity energy conversion system known as hydrocratic generator. The system relies on the difference between the salinity of the incoming fresh water and the surrounding sea water in the generator. In this investigation, additional parameter is introduced which is the temperature difference between the two fluids; hence the system is known as Ocean Salinity and Temperature Energy Conversion System (OSTEC). The investigation is divided into two papers. This first paper of Part 1 presents the theoretical formulation by considering the effect of fluid dynamic viscosity known as Viscosity Model and later compares with the conventional formulation which is Density Model. The dynamic viscosity model is used to predict the dynamic of the fluids in the system which in turns gives the analytical formulation of the potential power output that can be harvested.
Keywords: Buoyancy, density, frictional head loss, kinetic power, viscosity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18573010 Thermochemical Conversion: Jatropha curcus in Fixed Bed Reactor Using Slow Pyrolysis
Authors: Vipan Kumar Sohpal, Rajesh Kumar Sharma
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Thermochemical conversion of non-edible biomass offers an efficient and economically process to provide valuable fuels and prepare chemicals derived from biomass in the context of developing countries. Pyrolysis has advantages over other thermochemical conversion techniques because it can convert biomass directly into solid, liquid and gaseous products by thermal decomposition of biomass in the absence of oxygen. The present paper aims to focus on the slow thermochemical conversion processes for non-edible Jatropha curcus seed cake. The present discussion focuses on the effect of nitrogen gas flow rate on products composition (wt %). In addition, comparative analysis has been performed for different mesh size for product composition. Result shows that, slow pyrolysis experiments of Jatropha curcus seed cake in fixed bed reactor yield the bio-oil 18.42 wt % at a pyrolysis temperature of 500°C, particle size of -6+8 mesh number and nitrogen gas flow rate of 150 ml/min.
Keywords: Jatropha curcus, Thermo-chemical, Pyrolysis, Product composition, Yield.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28483009 Impregnation of Cupper into Kanuma Volcanic Ash Soil to Improve Mercury Sorption Capacity
Authors: Jatindra N. Bhakta, Yukihiro Munekage
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The present study attempted to improve the Mercury (Hg) sorption capacity of kanuma volcanic ash soil (KVAS) by impregnating the cupper (Cu). Impregnation was executed by 1 and 5% Cu powder and sorption characterization of optimum Hg removing Cu impregnated KVAS was performed under different operational conditions, contact time, solution pH, sorbent dosage and Hg concentration using the batch operation studies. The 1% Cu impregnated KVAS pronounced optimum improvement (79%) in removing Hg from water compare to control. The present investigation determined the equilibrium state of maximum Hg adsorption at 6 h contact period. The adsorption revealed a pH dependent response and pH 3.5 showed maximum sorption capacity of Hg. Freundlich isotherm model is well fitted with the experimental data than that of Langmuir isotherm. It can be concluded that the Cu impregnation improves the Hg sorption capacity of KVAS and 1% Cu impregnated KVAS could be employed as cost-effective adsorbent media for treating Hg contaminated water.Keywords: Cupper, impregnation, isotherm, kanuma volcanic ash soil, mercury, sorption
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16543008 Optimal Design of a PV/Diesel Hybrid System for Decentralized Areas through Economic Criteria
Authors: D. Tsuanyo, D. Aussel, Y. Azoumah, P. Neveu
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An innovative concept called “Flexy-Energy” is developing at 2iE. This concept aims to produce electricity at lower cost by smartly mix different available energy sources in accordance to the load profile of the region. With a higher solar irradiation and due to the fact that Diesel generator are massively used in sub-Saharan rural areas, PV/Diesel hybrid systems could be a good application of this concept and a good solution to electrify this region, provided they are reliable, cost effective and economically attractive to investors. Presentation of the developed approach is the aims of this paper. The PV/Diesel hybrid system designed consists to produce electricity and/or heat from a coupling between Diesel Diesel generators and PV panels without batteries storage, while ensuring the substitution of gasoil by bio-fuels available in the area where the system will be installed. The optimal design of this system is based on his technical performances; the Life Cycle Cost (LCC) and Levelized Cost of Energy are developed and use as economic criteria. The Net Present Value (NPV), the internal rate of return (IRR) and the discounted payback (DPB) are also evaluated according to dual electricity pricing (in sunny and unsunny hours). The PV/Diesel hybrid system obtained is compared to the standalone Diesel Diesel generators. The approach carried out in this paper has been applied to Siby village in Mali (Latitude 12 ° 23'N 8 ° 20'W) with 295 kWh as daily demand.This approach provides optimal physical characteristics (size of the components, number of component) and dynamical characteristics in real time (number of Diesel generator on, their load rate, fuel specific consumptions, and PV penetration rate) of the system. The system obtained is slightly cost effective; but could be improved with optimized tariffing strategies.
Keywords: Investments criteria, Optimization, PV hybrid, Sizing, Rural electrification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20433007 Solar Seawater Desalination Still with Seawater Preheater Using Efficient Heat Transfer Oil: Numerical Investigation and Data Verification
Authors: Ahmed N. Shmroukh, Gamal Tag Abdel-Jaber, Rashed D. Aldughpassi
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The feasibility of improving the performance of the proposed solar still unit which operated in very hot climate is investigated numerically and verified with experimental data. This solar desalination unit with proposed auxiliary device as seawater preheating system using petrol based textherm oil was used to produce pure fresh water from seawater. The effective evaporation area of basin is about 1 m2. The unit was tested in two main operation modes which are normal and with seawater preheating system. The results showed that, there is good agreement between the theoretical data and the experimental data; this means that the numerical model can be accurately dependable for predicting the proposed solar still performance and design parameters. The results also showed that the fresh water productivity of the solar still in the modified preheating case which is higher than normal case, leads to an increase in productivity of 42%.Keywords: Improving productivity, seawater desalination, solar stills, theoretical model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7553006 Durability of LDPE Geomembrane within Sealing System of MSW (Landfill)
Authors: L. Menaa, A. Cherifi, K. Tigouirat, M. Choura
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Analyse of locally manufactured Low Density Polyethylene (LDPE) durability, used within lining systems at bottom of Municipal Solid Waste (landfill), is done in the present work. For this end, short and middle time creep behavior under tension of the analyzed material is carried out. The locally manufactured material is tested and compared to the European one (LDPE-CE). Both materials was tested in 03 various mediums: ambient and two aggressive (salty water and foam water), using three specimens in each case. A testing campaign is carried out using an especially designed and achieved testing bench. Moreover, characterisation tests were carried out to evaluate the medium effect on the mechanical properties of the tested material (LDPE). Furthermore, experimental results have been used to establish a law regression which can be used to predict creep behaviour of the analyzed material. As a result, the analyzed LDPE material has showed a good stability in different ambient and aggressive mediums; as well, locally manufactured LDPE seems more flexible, compared with the European one. This makes it more useful to the desired application.
Keywords: LDPE membrane, solid waste, aggressive mediums, durability
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