Search results for: irrational number storage
11053 Mixed Convective Heat Transfer of Flow around a Radial Heat Sink
Authors: Benkherbache Souad
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This work presents the numerical results of the mixed convective heat transfer of a three-dimensional flow around a radial heat sink composed of horizontal circular base fitted with rectangular fins. The governing equations of mass, momentum, and energy equation are solved by the finite volume method using the commercially available CFD software Fluent 6.3.26. The circular base of the heat sink is subjected to uniform heat generation; the flow enters through the sides of the heat sink around the fins then the heat is transmitted from the base to the fins afterwards the fluid. In this study two fluids are utilized, in the first case, the air for the following Reynolds numbers Re=600,900,1200 and a Grashof number Gr=3.7x10⁶, in the second case a water based nano fluid for which two types of nano particles (Cu and Al₂O₃) are carried out for Re=25 and a Richardson number Ri=2.7(Ri=Gr/Re²). The effect of the number of the fins of the heat sink as well as the type and the volume fraction of nano particles of the nano fluid were investigated. Results have been presented for N=15 and N=20 fins. The effect of the nano particles concentrations and the number of fins on the temperature in the heat sink and the Nusselt number has been studied.Keywords: heat sink, mixed convection, nano fluid, volumetric heat generation
Procedia PDF Downloads 17611052 A Students' Ability Analysis Methods, Devices, Electronic Equipment and Storage Media Design
Authors: Dequn Teng, Tianshuo Yang, Mingrui Wang, Qiuyu Chen, Xiao Wang, Katie Atkinson
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Currently, many students are kind of at a loss in the university due to the complex environment within the campus, where every information within the campus is isolated with fewer interactions with each other. However, if the on-campus resources are gathered and combined with the artificial intelligence modelling techniques, there will be a bridge for not only students in understanding themselves, and the teachers will understand students in providing a much efficient approach in education. The objective of this paper is to provide a competency level analysis method, apparatus, electronic equipment, and storage medium. It uses a user’s target competency level analysis model from a plurality of predefined candidate competency level analysis models by obtaining a user’s promotion target parameters, promotion target parameters including at least one of the following parameters: target profession, target industry, and the target company, according to the promotion target parameters. According to the parameters, the model analyzes the user’s ability level, determines the user’s ability level, realizes the quantitative and personalized analysis of the user’s ability level, and helps the user to objectively position his ability level.Keywords: artificial intelligence, model, university, education, recommendation system, evaluation, job hunting
Procedia PDF Downloads 13811051 Introduction to Paired Domination Polynomial of a Graph
Authors: Puttaswamy, Anwar Alwardi, Nayaka S. R.
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One of the algebraic representation of a graph is the graph polynomial. In this article, we introduce the paired-domination polynomial of a graph G. The paired-domination polynomial of a graph G of order n is the polynomial Dp(G, x) with the coefficients dp(G, i) where dp(G, i) denotes the number of paired dominating sets of G of cardinality i and γpd(G) denotes the paired-domination number of G. We obtain some properties of Dp(G, x) and its coefficients. Further, we compute this polynomial for some families of standard graphs. Further, we obtain some characterization for some specific graphs.Keywords: domination polynomial, paired dominating set, paired domination number, paired domination polynomial
Procedia PDF Downloads 22611050 Introduction to Transversal Pendant Domination in Graphs
Authors: Nayaka S.R., Putta Swamy, Purushothama S.
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Let G=(V, E) be a graph. A dominating set S in G is a pendant dominating set if < S > contains a pendant vertex. A pendant dominating set of G which intersects every minimum pendant dominating set in G is called a transversal pendant dominating set. The minimum cardinality of a transversal pendant dominating set is called the transversal pendant domination number of G, denoted by γ_tp(G). In this paper, we begin to study this parameter. We calculate γ_tp(G) for some families of graphs. Furthermore, some bounds and relations with other domination parameters are obtained for γ_tp(G).Keywords: dominating set, pendant dominating set, pendant domination number, transversal pendant dominating set, transversal pendant domination number
Procedia PDF Downloads 17811049 Methylprednisolone Injection Did Not Inhibit Anti-Hbs Response Following Hepatitis B Vaccination in Mice
Authors: P. O. Ughachukwu, P. O. Okonkwo, P. C. Unekwe, J. O. Ogamba
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Background: The prevalence of hepatitis B viral infection is high worldwide with liver cirrhosis and hepatocellular carcinoma as important complications. Cases of poor antibody response to hepatitis B vaccination abound. Immunosuppression, especially from glucocorticoids, is often cited as a cause of poor antibody response and there are documented evidences of irrational administration of glucocorticoids to children and adults. The study was, therefore, designed to find out if administration of glucocorticoids affects immune response to vaccination against hepatitis B in mice. Methods: Mice of both sexes were randomly divided into 2 groups. Daily intramuscular methylprednisolone injections, (15 mg kg-1), were given to the test group while sterile deionized water (0.1ml) was given to control mice for 30 days. On day 6 all mice were given 2 μg (0.1ml) hepatitis B vaccine and a booster dose on day 27. On day 34, blood samples were collected and analyzed for anti-HBs titres using enzyme-linked immunosorbent assay (ELISA). Statistical analysis was done using Graph Pad Prism 5.0 and the results taken as statistically significant at p value < 0.05. Results: There were positive serum anti-HBs responses in all mice groups but the differences in titres were not statistically significant. Conclusions: At the dosages and length of exposure used in this study, methylprednisolone injection did not significantly inhibit anti-HBs response in mice following immunization against hepatitis B virus. By extrapolation, methylprednisolone, when used in the usual clinical doses and duration of therapy, is not likely to inhibit immune response to hepatitis B vaccinations in man.Keywords: anti-HBs, hepatitis B vaccine, immune response, methylprednisolone, mice
Procedia PDF Downloads 31911048 Effect of Whey Protein Based Edible Coating on the Moisture Loss and Sensory Attributes of Fresh Mutton
Authors: Saba Belgheisi
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Food packaging, is an important discipline in the area of food technology, concerns preservation and protection of foods. The objective of this research was to determine of the effect of whey protein based edible coating on the moisture loss and sensory attributes of fresh mutton after 0, 1, 3 and 5 days at 5° C. The moisture content, moisture loss and sensory attributes (juiciness, color and odor) of the coated and uncoated samples were analyzed. The results showed that, moisture content, moisture loss, juiciness and color of the coated and uncoated samples have significant differences (p < 0.05) at the intervals of 0 to 1 and 1 to 3 days of storage. But no significant difference was observed at interval time 3 to 5 days of storage (p > 0.05). Also, there was no significant differences in the odor values of the coated and uncoated samples (p > 0.05). Therefore, the coated samples had consistently more moisture, juiciness and colored values than uncoated samples after 3 days at 5° C. So, whey protein edible coating could enhance product presentation and eliminate the need for placing absorbent pads at the bottom of the trays.Keywords: coating, whey protein, mutton, moisture, sensory
Procedia PDF Downloads 45711047 Thermal Stability and Crystallization Behaviour of Modified ABS/PP Nanocomposites
Authors: Marianna I. Triantou, Petroula A. Tarantili
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In this research work, poly (acrylonitrile-butadiene-styrene)/polypropylene (ABS/PP) blends were processed by melt compounding in a twin-screw extruder. Upgrading of the thermal characteristics of the obtained materials was attempted by the incorporation of organically modified montmorillonite (OMMT), as well as, by the addition of two types of compatibilizers; polypropylene grafted with maleic anhydride (PP-g-MAH) and ABS grafted with maleic anhydride (ABS-g-MAH). The effect of the above treatments was investigated separately and in combination. Increasing the PP content in ABS matrix seems to increase the thermal stability of their blend and the glass transition temperature (Tg) of SAN phase of ABS. From the other part, the addition of ABS to PP promotes the formation of its β-phase, which is maximum at 30 wt% ABS concentration, and increases the crystallization temperature (Tc) of PP. In addition, it increases the crystallization rate of PP.The β-phase of PP in ABS/PP blends is reduced by the addition of compatibilizers or/and organoclay reinforcement. The incorporation of compatibilizers increases the thermal stability of PP and reduces its melting (ΔΗm) and crystallization (ΔΗc) enthalpies. Furthermore it decreases slightly the Tgs of PP and SAN phases of ABS/PP blends. Regarding the storage modulus of the ABS/PP blends, it presents a change in their behavior at about 10°C and return to their initial behavior at ~110°C. The incorporation of OMMT to no compatibilized and compatibilized ABS/PP blends enhances their storage modulus.Keywords: acrylonitrile, butadiene, styrene terpolymer, compatibilizer, organoclay, polypropylene
Procedia PDF Downloads 31611046 Effect of Citric Acid and Clove on Cured Smoked Meat: A Traditional Meat Product
Authors: Esther Eduzor, Charles A. Negbenebor, Helen O. Agu
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Smoking of meat enhances the taste and look of meat, it also increases its longevity, and helps preserve the meat by slowing down the spoilage of fat and growth of bacteria. The Lean meat from the forequarter of beef carcass was obtained from the Maiduguri abattoir. The meat was cut into four portions with weight ranging from 525-545 g. The meat was cut into bits measuring about 8 cm in length, 3.5 cm in thickness and weighed 64.5 g. Meat samples were washed, cured with various concentration of sodium chloride, sodium nitrate, citric acid and clove for 30 min, drained and smoked in a smoking kiln at a temperature range of 55-600°C, for 8 hr a day for 3 days. The products were stored at ambient temperature and evaluated microbiologically and organoleptically. In terms of processing and storage there were increases in pH, free fatty acid content, a decrease in water holding capacity and microbial count of the cured smoked meat. The panelists rated control samples significantly (p < 0.05) higher in terms of colour, texture, taste and overall acceptability. The following organisms were isolated and identified during storage: Bacillus specie, Bacillus subtilis, streptococcus, Pseudomonas, Aspergillus niger, Candida and Penicillium specie. The study forms a basis for new product development for meat industry.Keywords: citric acid, cloves, smoked meat, bioengineering
Procedia PDF Downloads 44011045 A Method for solving Legendre's Conjecture
Authors: Hashem Sazegar
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Legendre’s conjecture states that there is a prime number between n^2 and (n + 1)^2 for every positive integer n. In this paper we prove that every composite number between n2 and (n + 1)2 can be written u^2 − v^2 or u^2 − v^2 + u − v that u > 0 and v ≥ 0. Using these result as well as induction and residues (modq) we prove Legendre’s conjecture.Keywords: bertrand-chebyshev theorem, landau’s problems, goldbach’s conjecture, twin prime, ramanujan proof
Procedia PDF Downloads 35511044 Correlation Studies and Heritability Estimates among Onion (Allium Cepa L.) Cultivars of North Western Nigeria
Authors: L. Abubakar, B. M. Sokoto, I. U. Mohammed, M. S. Na’allah, A. Mohammad, A. N. Garba, T. S. Bubuche
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Onion (Allium cepa var. cepa L.), is the most important species of the Allium group belonging to family Alliaceae and genus Allium. It can be regarded as the single important vegetable species in the world after tomatoes. Despite the similarities, which bring the species together, the genus is a strikingly diverse one, with more than five hundred species, which are perennial and mostly bulbous plants. Out of these, only seven species are in cultivation, and five are the most important species of the cultivated Allium. However, Allium cepa (onion) and Allium sativum (Garlic) are the two major cultivated species grown all over the world of which the onion crop is the most important. Heritability defined as the proportion of the observed total variability that is genetic, and its estimates from variance components give more useful information of genotypic variation from the total phenotypic differences and environmental effects on the individuals or families. It therefore guide the breeder with respect to the ease with which selection of traits can be carried out. Heritability estimates guide the breeder with respect to ease of selection of traits while correlations suggest how selection among characters can be practiced. Correlations explain relationship between characters and suggest how selection among characters can be practiced in breeding programmes. Highly significant correlations have been reported, between yield, maturity, rings/bulb and storage loss in onions. Similarly significant positive correlation exists between total bulb yield and plant height, leaf number/plant, bulb diameter and bulb yield/plant. Moderate positive correlations have been observed between maturity date and yield, dry matter content was highly correlated with soluble solids, and higher correlations were also observed between storage loss and soluble solids. The objective of the study is to determine heritability estimates and correlations for characters among onion cultivars of North Western Nigeria. This is envisaged will assist in the breeding of superior onion cultivars within the zone. Thirteen onion cultivars were collected during an expedition covering north western Nigeria and Southern part of Niger Republic during 2013, which are areas noted for onion production. The cultivars were evaluated at two locations; Sokoto, in Sokoto State and Jega in Kebbi State all in Nigeria during the 2013/14 onion season (dry season) under irrigation. Combined analysis of the results revealed fresh bulb yield is highly significantly positively correlated with bulb height and cured bulb yield, and significant positive correlation with plant height and bulb diameter. It also recorded significant negative correlation with mean No. of leaves/plant and non significant negative correlation with bolting %. Cured bulb yield (marketable yield) had highly significant positive correlation with mean bulb weight and fresh bulb yield/ha, with significant positive correlation with bulb height. It also recorded highly significant negative correlation with No. of leaves/plant and significant negative correlation with bolting % and non significant positive correlation with plant height and non significant negative correlation with bulb diameter. High broad sense heritability estimates were recorded for plant height, fresh bulb yield, number of leaves/plant, bolting % and cured bulb yield. Medium to low broad sense heritabilities were also observed for mean bulb weight, plant height and bulb diameter.Keywords: correlation, heritability, onions, North Western Nigeria
Procedia PDF Downloads 39511043 Sinusoidal Roughness Elements in a Square Cavity
Authors: Muhammad Yousaf, Shoaib Usman
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Numerical studies were conducted using Lattice Boltzmann Method (LBM) to study the natural convection in a square cavity in the presence of roughness. An algorithm basedon a single relaxation time Bhatnagar-Gross-Krook (BGK) model of Lattice Boltzmann Method (LBM) was developed. Roughness was introduced on both the hot and cold walls in the form of sinusoidal roughness elements. The study was conducted for a Newtonian fluid of Prandtl number (Pr) 1.0. The range of Ra number was explored from 103 to 106 in a laminar region. Thermal and hydrodynamic behavior of fluid was analyzed using a differentially heated square cavity with roughness elements present on both the hot and cold wall. Neumann boundary conditions were introduced on horizontal walls with vertical walls as isothermal. The roughness elements were at the same boundary condition as corresponding walls. Computational algorithm was validated against previous benchmark studies performed with different numerical methods, and a good agreement was found to exist. Results indicate that the maximum reduction in the average heat transfer was16.66 percent at Ra number 105.Keywords: Lattice Boltzmann method, natural convection, nusselt number, rayleigh number, roughness
Procedia PDF Downloads 52311042 Incremental Learning of Independent Topic Analysis
Authors: Takahiro Nishigaki, Katsumi Nitta, Takashi Onoda
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In this paper, we present a method of applying Independent Topic Analysis (ITA) to increasing the number of document data. The number of document data has been increasing since the spread of the Internet. ITA was presented as one method to analyze the document data. ITA is a method for extracting the independent topics from the document data by using the Independent Component Analysis (ICA). ICA is a technique in the signal processing; however, it is difficult to apply the ITA to increasing number of document data. Because ITA must use the all document data so temporal and spatial cost is very high. Therefore, we present Incremental ITA which extracts the independent topics from increasing number of document data. Incremental ITA is a method of updating the independent topics when the document data is added after extracted the independent topics from a just previous the data. In addition, Incremental ITA updates the independent topics when the document data is added. And we show the result applied Incremental ITA to benchmark datasets.Keywords: text mining, topic extraction, independent, incremental, independent component analysis
Procedia PDF Downloads 30311041 Comparison of White Sauce Prepared from Native and Chemically Modified Corn and Pearl Millet Starches
Authors: Marium Shaikh, Tahira M. Ali, Abid Hasnain
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Physical and sensory properties of white sauces prepared from native and chemically modified corn and pearl millet starches were compared. Interestingly, no syneresis was observed in hydroxypropylated corn and pearl millet starch containing white sauce even after nine days of cold storage (4 °C), while other modifications also reduced the syneresis significantly in comparison to their native counterparts. White sauce containing succinylated corn starch showed least oil separation due to its greater emulsion stability. Light microscopy was used to visualize the size and shape of fat globules, and it was found that they were most homogenously distributed in succinylated and hydroxypropylated samples. Sensory results revealed that chemical modification of corn and pearl millet starch improved the consistency, thickness and overall acceptability of white sauces. Viscosity profiles showed that pasting parameters of native pearl millet starch are almost similar to native corn starch suggesting pearl millet starch as an alternative of corn starch. Also, white sauce prepared from modified pearl millet starch showed better cold storage stability in terms of various textural attributes like hardness, cohesiveness, chewiness, and springiness.Keywords: corn starch, pearl millet, hydroxypropylation, succinylation, white sauce
Procedia PDF Downloads 27611040 The Influence of Emotion on Numerical Estimation: A Drone Operators’ Context
Authors: Ludovic Fabre, Paola Melani, Patrick Lemaire
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The goal of this study was to test whether and how emotions influence drone operators in estimation skills. The empirical study was run in the context of numerical estimation. Participants saw a two-digit number together with a collection of cars. They had to indicate whether the stimuli collection was larger or smaller than the number. The two-digit numbers ranged from 12 to 27, and collections included 3-36 cars. The presentation of the collections was dynamic (each car moved 30 deg. per second on the right). Half the collections were smaller collections (including fewer than 20 cars), and the other collections were larger collections (i.e., more than 20 cars). Splits between the number of cars in a collection and the two-digit number were either small (± 1 or 2 units; e.g., the collection included 17 cars and the two-digit number was 19) or larger (± 8 or 9 units; e.g., 17 cars and '9'). Half the collections included more items (and half fewer items) than the number indicated by the two-digit number. Before and after each trial, participants saw an image inducing negative emotions (e.g., mutilations) or neutral emotions (e.g., candle) selected from International Affective Picture System (IAPS). At the end of each trial, participants had to say if the second picture was the same as or different from the first. Results showed different effects of emotions on RTs and percent errors. Participants’ performance was modulated by emotions. They were slower on negative trials compared to the neutral trials, especially on the most difficult items. They errored more on small-split than on large-split problems. Moreover, participants highly overestimated the number of cars when in a negative emotional state. These findings suggest that emotions influence numerical estimation, that effects of emotion in estimation interact with stimuli characteristics. They have important implications for understanding the role of emotions on estimation skills, and more generally, on how emotions influence cognition.Keywords: drone operators, emotion, numerical estimation, arithmetic
Procedia PDF Downloads 11211039 Extraction of Inulin from Cichorium Intybus and Its Application as Fat Replacer in Yoghurt
Authors: Hafiz Khuram Wasim Aslam, Muhammad Saeed, Azam Shakeel, Muhammad Inam Ur Raheem, Moazzam Rafiq Khan, Muhammad Atif Randhawa
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Inulin is significant ingredient used in food industry that functions technologically as a fat replacer often without compromising taste and texture. In this study inulin was extracted from the chicory roots and the effect of inulin addition as a fat replacer on the physiochemical, microbiological and sensory properties of non-fat yogurt was investigated. The supplementation of chicory inulin reduced the magnitude of firmness in comparison with non-inulin ¬supplemented non-fat yoghurt. Higher values of acidity were observed due to the more microbial fermentation in the inulin containing yogurt as compared to non-inulin yogurt and were in the range of 0.56 to 0.75 during storage days. Syneresis in control sample increased from 43.9% to 47.9% during the storage study. However inulin addition at different treatment enhanced syneresis from 44.5% to 47.6%. Inulin addition at various concentrations caused an increase in the TPC due to its probiotic effect. No effects of inuline addition on fat and protein contents were observed. Non-fat yoghurt supplemented with inulin demonstrated sensory behavior better than that of the control yoghurt. The most important effect of the addition of inulin to non-fat yoghurt is an increase in the sensory attributes appearance, body and texture, taste and mouth feel, overall acceptability. On an average, yoghurt supplemented with 1 to 2% inulin was better in overall acceptance as compared to control yoghurt.Keywords: inulin, fat replacer, yoghurt, sensory evaluation, low fat
Procedia PDF Downloads 58211038 Solubility of Water in CO2 Mixtures at Pipeline Operation Conditions
Authors: Mohammad Ahmad, Sander Gersen, Erwin Wilbers
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Carbon capture, transport and underground storage have become a major solution to reduce CO2 emissions from power plants and other large CO2 sources. A big part of this captured CO2 stream is transported at high pressure dense phase conditions and stored in offshore underground depleted oil and gas fields. CO2 is also transported in offshore pipelines to be used for enhanced oil and gas recovery. The captured CO2 stream with impurities may contain water that causes severe corrosion problems, flow assurance failure and might damage valves and instrumentations. Thus, free water formation should be strictly prevented. The purpose of this work is to study the solubility of water in pure CO2 and in CO2 mixtures under real pipeline pressure (90-150 bar) and temperature operation conditions (5-35°C). A set up was constructed to generate experimental data. The results show the solubility of water in CO2 mixtures increasing with the increase of the temperature or/and with the increase in pressure. A drop in water solubility in CO2 is observed in the presence of impurities. The data generated were then used to assess the capabilities of two mixture models: the GERG-2008 model and the EOS-CG model. By generating the solubility data, this study contributes to determine the maximum allowable water content in CO2 pipelines.Keywords: carbon capture and storage, water solubility, equation of states, fluids engineering
Procedia PDF Downloads 28811037 Hierarchical Operation Strategies for Grid Connected Building Microgrid with Energy Storage and Photovoltatic Source
Authors: Seon-Ho Yoon, Jin-Young Choi, Dong-Jun Won
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This paper presents hierarchical operation strategies which are minimizing operation error between day ahead operation plan and real time operation. Operating power systems between centralized and decentralized approaches can be represented as hierarchical control scheme, featured as primary control, secondary control and tertiary control. Primary control is known as local control, featuring fast response. Secondary control is referred to as microgrid Energy Management System (EMS). Tertiary control is responsible of coordinating the operations of multi-microgrids. In this paper, we formulated 3 stage microgrid operation strategies which are similar to hierarchical control scheme. First stage is to set a day ahead scheduled output power of Battery Energy Storage System (BESS) which is only controllable source in microgrid and it is optimized to minimize cost of exchanged power with main grid using Particle Swarm Optimization (PSO) method. Second stage is to control the active and reactive power of BESS to be operated in day ahead scheduled plan in case that State of Charge (SOC) error occurs between real time and scheduled plan. The third is rescheduling the system when the predicted error is over the limited value. The first stage can be compared with the secondary control in that it adjusts the active power. The second stage is comparable to the primary control in that it controls the error in local manner. The third stage is compared with the secondary control in that it manages power balancing. The proposed strategies will be applied to one of the buildings in Electronics and Telecommunication Research Institute (ETRI). The building microgrid is composed of Photovoltaic (PV) generation, BESS and load and it will be interconnected with the main grid. Main purpose of that is minimizing operation cost and to be operated in scheduled plan. Simulation results support validation of proposed strategies.Keywords: Battery Energy Storage System (BESS), Energy Management System (EMS), Microgrid (MG), Particle Swarm Optimization (PSO)
Procedia PDF Downloads 24411036 The Long-Term Leaching Behaviour of 137Cs, 60Co and 152Eu Radionuclides Incorporated in Mortar Matrices Made from Natural Aggregates and Recycled Aggregates
Authors: R. Deju, M. Mincu, D. Gurau
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During the interim storage or final disposal of low level waste, migration/diffusion of radionuclides can occur when the waste comes in contact with water. The long-term leaching behaviour into surrounding fluid (demineralized water) of 137Cs, 60Co and 152Eu radionuclides, artificially incorporated in mortar matrices made from natural aggregates (river sand) and recycled radioactive concrete was studied. Results presented in this work are obtained in two years of mortar testing and will be used for the safety increasing in the storage of low level radioactive waste. The study involved the influence of curing time, type and size distribution of the aggregates on leaching behaviour. The mortar samples were immersed in distilled water for 30 days. The leached activity of the mortar samples was measured on samples from the immersing water and analyzed through a gamma-ray spectrometry method using an HPGe detector with a GESPECOR code for efficiency evaluation. The long-term leaching behaviour of the radionuclides was evaluated from the leaching data calculating the apparent diffusion coefficient.Keywords: gamma spectrometry, leaching behavior, reuse and recycling of radioactive concrete, waste management
Procedia PDF Downloads 23811035 Effect an Axial Magnetic Field in Co-rotating Flow Heated from Below
Authors: B. Mahfoud, A. Bendjagloli
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The effect of an axial magnetic field on the flow produced by co-rotation of the top and bottom disks in a vertical cylindrical heated from below is numerically analyzed. The governing Navier-Stokes, energy, and potential equations are solved by using the finite-volume method. It was observed that the Reynolds number is increased, the axisymmetric basic state loses stability to circular patterns of axisymmetric vortices and spiral waves. In mixed convection case the axisymmetric mode disappears giving an asymmetric mode m=1. It was also found that the primary thresholds Recr corresponding to the modes m=1and 2, increase with increasing of the Hartmann number (Ha). Finally, stability diagrams have been established according to the numerical results of this investigation. These diagrams giving the evolution of the primary thresholds as a function of the Hartmann number for various values of the Richardson number.Keywords: bifurcation, co-rotating end disks, magnetic field, stability diagrams, vortices
Procedia PDF Downloads 34111034 A Comparative Study of Multi-SOM Algorithms for Determining the Optimal Number of Clusters
Authors: Imèn Khanchouch, Malika Charrad, Mohamed Limam
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The interpretation of the quality of clusters and the determination of the optimal number of clusters is still a crucial problem in clustering. We focus in this paper on multi-SOM clustering method which overcomes the problem of extracting the number of clusters from the SOM map through the use of a clustering validity index. We then tested multi-SOM using real and artificial data sets with different evaluation criteria not used previously such as Davies Bouldin index, Dunn index and silhouette index. The developed multi-SOM algorithm is compared to k-means and Birch methods. Results show that it is more efficient than classical clustering methods.Keywords: clustering, SOM, multi-SOM, DB index, Dunn index, silhouette index
Procedia PDF Downloads 59211033 Nitrogen Doping Effect on Enhancement of Electrochemical Performance of a Carbon Nanotube Based Microsupercapacitor
Authors: Behnoush Dousti, Ye Choi, Gil S. Lee
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Microsupercapacitors (MScs) are known as the future of miniaturized energy sources that can be coupled to a battery to deliver stable and constant energy to microelectronics. Among all their counterparts, electrochemical microsupercapacitor have drawn the most research attention due to their higher power density and long cycle life. Designing the microstructure and choosing the electroactive materials are two significant factors that greatly affect the performance of the device. Here, we report successful fabrication and characterization of a microsupercapacitor with interdigitated structure based on Carbon nanotube sheets (CNT sheet). Novel structure of highly aligned CNT sheet as the electrode materials which also offers excellent conductivity and large surface area along with doping with nitrogen, enabled us to develop a device with serval order of magnitude higher electrochemical performance than the pristine CNT in aqueous electrolyte including high specific capacitance and rate capabilities and excellent cycle life over 10000 cycles. Geometric parameters such as finger width and gap size were also studied and it was shown the device performance is much depended on them. Results of this study confirms the potential of CNT sheet for future energy storage devices.Keywords: carbon nanotube, energy storage systems, microsupercapacitor, nitrogen doping
Procedia PDF Downloads 12511032 Development of an Energy Independant DC Building Demonstrator for Insulated Island Site
Authors: Olivia Bory Devisme, Denis Genon-Catalot, Frederic Alicalapa, Pierre-Olivier Lucas De Peslouan, Jean-Pierre Chabriat
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In the context of climate change, it is essential that island territories gain energy autonomy. Currently mostly dependent on fossil fuels, the island of Reunion lo- cated in the Indian Ocean nevertheless has a high potential for solar energy. As the market for photovoltaic panels has been growing in recent years, the issues of energy losses linked to the multiple conversions from direct current to alternating current are emerging. In order to quantify these advantages and disadvantages by a comparative study, this document present the measurements carried out on a direct current test bench, particularly for lighting, ventilation, air condi- tioning and office equipment for the tertiary sector. All equipment is supplied with DC power from energy produced by photovoltaic panels. A weather sta- tion, environmental indoor sensors, and drivers are also used to control energy. Self-consumption is encouraged in order to manage different priorities between user consumption and energy storage in a lithium iron phosphate battery. The measurements are compared to a conventional electrical architecture (DC-AC- DC) for energy consumption, equipment overheating, cost, and life cycle analysis.Keywords: DC microgrids, solar energy, smart buildings, storage
Procedia PDF Downloads 15711031 A Novel Multi-Objective Park and Ride Control Scheme Using Renewable Energy Sources: Cairo Case Study
Authors: Mohammed Elsayed Lotfy Elsayed Abouzeid, Tomonobu Senjyu
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A novel multi-objective park and ride control approach is presented in this research. Park and ride will encourage the owners of the vehicles to leave their cars in the nearest points (on the edges of the crowded cities) and use public transportation facilities (train, bus, metro, or mon-rail) to reach their work inside the crowded city. The proposed control scheme is used to design electric vehicle charging stations (EVCS) to charge 1000 electric vehicles (EV) during their owners' work time. Cairo, Egypt is used as a case study. Photovoltaic (PV) and battery energy storage system (BESS) are used to meet the EVCS demand. Two multi-objective optimization techniques (MOGA and epsilon-MOGA) are utilized to get the optimal sizes of PV and BESS so as to meet the load demand and minimize the total life cycle cost. Detailed analysis and comparison are held to investigate the performance of the proposed control scheme using MATLAB.Keywords: Battery Energy Storage System, Electric Vehicle, Park and Ride, Photovoltaic, Multi-objective
Procedia PDF Downloads 13511030 Development of Extruded Prawn Snack Using Prawn Flavor Powder from Prawn Head Waste
Authors: S. K. Sharma, P. Kumar, Pratibha Singh
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Consumption of SNACK is growing its popularity every day in India and a broad range of these items are available in the market. The end user interest in ready-to-eat snack foods is constantly growing mainly due to their ease, ample accessibility, appearance, taste and texture. Food extrusion has been practiced for over fifty years. Its role was initially limited to mixing and forming cereal products. Although thermoplastic extrusion has been successful for starch products, extrusion of proteins has achieved only limited success. In this study, value-added extruded prawn product was prepared with prawn flavor powder and corn flour using a twin-screw extruder. Prawn flavor concentrates prepared from fresh prawn head (Solenocera indica). To prepare flavor concentrate prawn head washed with potable water and blended with 200ml 3% salt solution per 250gm head weight to make the slurry, which was further put in muslin cloth and boiled with salt and starch solution for 10 minutes, cooled to room temperature and filtered, starch added to the filtrate and made into powder in an electrically drier at 43-450c. The mixture was passed through the twin-screw extruder (co-rotating twin screw extruder - basic technology Pvt. Ltd., Kolkata) which was operated at a particular speed of rotation, die diameter, temperature, moisture, and fish powder concentration. Many trial runs were conducted to set up the process variables. The different extrudes produced after each trail were examined for the quality and characteristics. The effect of temperature, moisture, screw speed, protein, fat, ash and thiobarbituric acid (TBA) number and expansion ratio were studied. In all the four trials, moisture, temperature, speed and die diameter used was 20%, 100°C, 350 rpm and 4 mm, respectively. The ratio of prawn powder and cornstarch used in different trials ranged between 2:98 and 10:90. The storage characteristics of the final product were studied using three different types of packaging under nitrogen flushing, i.e. a- 12-pm polyester, 12-pm metalized polyester, 60-11m polyethylene (metalized polyester a), b- 12-11m metalized polyester, 37.5-11m polyethylene (metalized polyester b), c- 12-11m polyethylene, 9-11m aluminium foil, 37.5-11m polyethylene (aluminium foil). The organoleptic analysis was carried out on a 9-point hedonic scale. The study revealed that the fried product packed in aluminum foil under nitrogen flushing would remain acceptable for more than three months.Keywords: extruded product, prawn flavor, twin-screw extruder, storage characteristics
Procedia PDF Downloads 13611029 Fuzzy Neuro Approach for Integrated Water Management System
Authors: Stuti Modi, Aditi Kambli
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This paper addresses the need for intelligent water management and distribution system in smart cities to ensure optimal consumption and distribution of water for drinking and sanitation purposes. Water being a limited resource in cities require an effective system for collection, storage and distribution. In this paper, applications of two mostly widely used particular types of data-driven models, namely artificial neural networks (ANN) and fuzzy logic-based models, to modelling in the water resources management field are considered. The objective of this paper is to review the principles of various types and architectures of neural network and fuzzy adaptive systems and their applications to integrated water resources management. Final goal of the review is to expose and formulate progressive direction of their applicability and further research of the AI-related and data-driven techniques application and to demonstrate applicability of the neural networks, fuzzy systems and other machine learning techniques in the practical issues of the regional water management. Apart from this the paper will deal with water storage, using ANN to find optimum reservoir level and predicting peak daily demands.Keywords: artificial neural networks, fuzzy systems, peak daily demand prediction, water management and distribution
Procedia PDF Downloads 17511028 Effect of Cuminum Cyminum L. Essential Oil on Staphylococcus Aureus during the Manufacture, Ripening and Storage of White Brined Cheese
Authors: Ali Misaghi, Afshin Akhondzadeh Basti, Ehsan Sadeghi
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Staphylococcus aureus is a pathogen of major concern for clinical infection and food borne illness. Humans and most domesticated animals harbor S. aureus, and so we may expect staphylococci to be present in food products of animal origin or in those handled directly by humans, unless heat processing is applied to destroy them. Cuminum cyminum L. has been allocated the topic of some recent studies in addition to its well-documented traditional usage for treatment of toothache, dyspepsia, diarrhea, epilepsy and jaundice. The air-dried seed of the plant was completely immersed in water and subjected to hydro distillation for 3 h, using a clevenger-type apparatus. In this study, the effect of Cuminum cyminum L. essential oil (EO) on growth of Staphylococcus aureus in white brined cheese was evaluated. The experiment included different levels of EO (0, 7.5, 15 and 30 mL/ 100 mL milk) to assess their effects on S. aureus count during the manufacture, ripening and storage of Iranian white brined cheese for up to 75 days. The significant (P < 0.05) inhibitory effects of EO (even at its lowest concentration) on this organism were observed. The significant (P < 0.05) inhibitory effect of the EO on S. aureus shown in this study may improve the scope of the EO function in the food industry.Keywords: cuminum cyminum L. essential oil, staphylococcus aureus, white brined cheese
Procedia PDF Downloads 38411027 Geochemical Characterization for Identification of Hydrocarbon Generation: Implication of Unconventional Gas Resources
Authors: Yousif M. Makeen
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This research will address the processes of geochemical characterization and hydrocarbon generation process occurring within hydrocarbon source and/or reservoir rocks. The geochemical characterization includes organic-inorganic associations that influence the storage capacity of unconventional hydrocarbon resources (e.g. shale gas) and the migration process of oil/gas of the petroleum source/reservoir rocks. Kerogen i.e. the precursor of petroleum, occurs in various forms and types, may either be oil-prone, gas-prone, or both. China has a number of petroleum-bearing sedimentary basins commonly associated with shale gas, oil sands, and oil shale. Taken Sichuan basin as a selected basin in this study, the Sichuan basin has recorded notable successful discoveries of shale gas especially in the marine shale reservoirs within the area. However, a notable discoveries of lacustrine shale in the North-Este Fuling area indicate the accumulation of shale gas within non-marine source rock. The objective of this study is to evaluate the hydrocarbon storage capacity, generation, and retention processes in the rock matrix of hydrocarbon source/reservoir rocks within the Sichuan basin using an advanced X-ray tomography 3D imaging computational technology, commonly referred to as Micro-CT, SEM (Scanning Electron Microscope), optical microscope as well as organic geochemical facilities (e.g. vitrinite reflectance and UV light). The preliminary results of this study show that the lacustrine shales under investigation are acting as both source and reservoir rocks, which are characterized by very fine grains and very low permeability and porosity. Three pore structures have also been characterized in the study in the lacustrine shales, including organic matter pores, interparticle pores and intraparticle pores using x-ray Computed Tomography (CT). The benefits of this study would be a more successful oil and gas exploration and higher recovery factor, thus having a direct economic impact on China and the surrounding region. Methodologies: SRA TOC/TPH or Rock-Eval technique will be used to determine the source rock richness (S1 and S2) and Tmax. TOC analysis will be carried out using a multi N/C 3100 analyzer. The SRA and TOC results were used in calculating other parameters such as hydrogen index (HI) and production index (PI). This analysis will indicate the quantity of the organic matter. Minimum TOC limits generally accepted as essential for a source-rock are 0.5% for shales and 0.2% for carbonates. Contributions: This research could solve issues related to oil potential, provide targets, and serve as a pathfinder to future exploration activity in the Sichuan basin.Keywords: shale gas, unconventional resources, organic chemistry, Sichuan basin
Procedia PDF Downloads 2711026 Experimental Investigation of Boundary Layer Transition on Rotating Cones in Axial Flow in 0 and 35 Degrees Angle of Attack
Authors: Ali Kargar, Kamyar Mansour
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In this paper, experimental results of using hot wire anemometer and smoke visualization are presented. The results obtained on the hot wire anemometer for critical Reynolds number and transitional Reynolds number are compared by previous results. Excellent agreement is found for the transitional Reynolds number. The results for the transitional Reynolds number are also compared by previous linear stability results. The results of the smoke visualization clearly show the cross flow vortices which arise in the transition process from a laminar to a turbulent flow. A non-zero angle of attack is also considered. We compare our results by linear stability theory which was done by Garret et. Al (2007). We just emphasis, Also the visualization and hot wire anemometer results have been compared graphically. The goal in this paper is to check reliability of using hot wire anemometer and smoke visualization in transition problems and check reliability of linear stability theory for this case and compare our results with some trusty experimental works.Keywords: transitional reynolds number, wind tunnel, rotating cone, smoke visualization
Procedia PDF Downloads 29511025 Elastic Behaviour of Graphene Nanoplatelets Reinforced Epoxy Resin Composites
Authors: V. K. Srivastava
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Graphene has recently attracted an increasing attention in nanocomposites applications because it has 200 times greater strength than steel, making it the strongest material ever tested. Graphene, as the fundamental two-dimensional (2D) carbon structure with exceptionally high crystal and electronic quality, has emerged as a rapidly rising star in the field of material science. Graphene, as defined, as a 2D crystal, is composed of monolayers of carbon atoms arranged in a honeycombed network with six-membered rings, which is the interest of both theoretical and experimental researchers worldwide. The name comes from graphite and alkene. Graphite itself consists of many graphite-sheets stacked together by weak van der Waals forces. This is attributed to the monolayer of carbon atoms densely packed into honeycomb structure. Due to superior inherent properties of graphene nanoplatelets (GnP) over other nanofillers, GnP particles were added in epoxy resin with the variation of weight percentage. It is indicated that the DMA results of storage modulus, loss modulus and tan δ, defined as the ratio of elastic modulus and imaginary (loss) modulus versus temperature were affected with addition of GnP in the epoxy resin. In epoxy resin, damping (tan δ) is usually caused by movement of the molecular chain. The tan δ of the graphene nanoplatelets/epoxy resin composite is much lower than that of epoxy resin alone. This finding suggests that addition of graphene nanoplatelets effectively impedes movement of the molecular chain. The decrease in storage modulus can be interpreted by an increasing susceptibility to agglomeration, leading to less energy dissipation in the system under viscoelastic deformation. The results indicates the tan δ increased with the increase of temperature, which confirms that tan δ is associated with magnetic field strength. Also, the results show that the nanohardness increases with increase of elastic modulus marginally. GnP filled epoxy resin gives higher value than the epoxy resin, because GnP improves the mechanical properties of epoxy resin. Debonding of GnP is clearly observed in the micrograph having agglomeration of fillers and inhomogeneous distribution. Therefore, DMA and nanohardness studies indiacte that the elastic modulus of epoxy resin is increased with the addition of GnP fillers.Keywords: agglomeration, elastic modulus, epoxy resin, graphene nanoplatelet, loss modulus, nanohardness, storage modulus
Procedia PDF Downloads 26011024 Three-Dimensional Numerical Simulation of Drops Suspended in Poiseuille Flow: Effect of Reynolds Number
Authors: A. Nourbakhsh
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A finite difference/front tracking method is used to study the motion of three-dimensional deformable drops suspended in plane Poiseuille flow at non-zero Reynolds numbers. A parallel version of the code was used to study the behavior of suspension on a reasonable grid resolution (grids). The viscosity and density of drops are assumed to be equal to that of the suspending medium. The effect of the Reynolds number is studied in detail. It is found that drops with small deformation behave like rigid particles and migrate to an equilibrium position about half way between the wall and the center line (the Segre-Silberberg effect). However, for highly deformable drops there is a tendency for drops to migrate to the middle of the channel, and the maximum concentration occurs at the center line. The effective viscosity of suspension and the fluctuation energy of the flow across the channel increases with the Reynolds number of the flow.Keywords: suspensions, Poiseuille flow, effective viscosity, Reynolds number
Procedia PDF Downloads 349