Search results for: base metal
1230 Synthesis and Characterization of New Thermotropic Liquid Crystals Derived from 4-Hydroxybenzaldehyde
Authors: Sie-Tiong Ha, Teck-Leong Lee, Yip-Foo Win, Siew-Ling Lee, Guan-Yeow Yeap
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A homologous series of aromatic esters, 4-nalkanoyloxybenzylidene- 4--bromoanilines, nABBA, consisting of two 1,4-disubstituted phenyl cores and a Schiff base central linkage was synthesized. All the members can be differed by the number of carbon atoms at terminal alkanoyloxy chain (CnH2n-1COO-, n = 2, 6, 18). The molecular structure of nABBA was confirmed with infrared spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and electron-ionization mass (EI-MS) spectrometry. Mesomorphic properties were studied using differential scanning calorimetry and polarizing optical microscopy.Keywords: Liquid Crystals, Schiff base, Smectic, Mesomorphic
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23951229 Using Automatic Ontology Learning Methods in Human Plausible Reasoning Based Systems
Authors: A. R. Vazifedoost, M. Rahgozar, F. Oroumchian
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Knowledge discovery from text and ontology learning are relatively new fields. However their usage is extended in many fields like Information Retrieval (IR) and its related domains. Human Plausible Reasoning based (HPR) IR systems for example need a knowledge base as their underlying system which is currently made by hand. In this paper we propose an architecture based on ontology learning methods to automatically generate the needed HPR knowledge base.Keywords: Ontology Learning, Human Plausible Reasoning, knowledge extraction, knowledge representation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15761228 Experimental Determination of Large Strain Localization in Cut Steel Chips
Authors: A. Simoneau
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Metal cutting is a severe plastic deformation process involving large strains, high strain rates, and high temperatures. Conventional analysis of the chip formation process is based on bulk material deformation disregarding the inhomogeneous nature of the material microstructure. A series of orthogonal cutting tests of AISI 1045 and 1144 steel were conducted which yielded similar process characteristics and chip formations. With similar shear angles and cut chip thicknesses, shear strains for both chips were found to range from 2.0 up to 2.8. The manganese-sulfide (MnS) precipitate in the 1144 steel has a very distinct and uniform shape which allows for comparison before and after chip formation. From close observations of MnS precipitates in the cut chips it is shown that the conventional approach underestimates plastic strains in metal cutting. Experimental findings revealed local shear strains around a value of 6. These findings and their implications are presented and discussed.Keywords: Machining, metal cutting, microstructure, plastic strains, local strain.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20881227 Nonlinear Dynamic Analysis of Base-Isolated Structures Using a Partitioned Solution Approach and an Exponential Model
Authors: Nicolò Vaiana, Filip C. Filippou, Giorgio Serino
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The solution of the nonlinear dynamic equilibrium equations of base-isolated structures adopting a conventional monolithic solution approach, i.e. an implicit single-step time integration method employed with an iteration procedure, and the use of existing nonlinear analytical models, such as differential equation models, to simulate the dynamic behavior of seismic isolators can require a significant computational effort. In order to reduce numerical computations, a partitioned solution method and a one dimensional nonlinear analytical model are presented in this paper. A partitioned solution approach can be easily applied to base-isolated structures in which the base isolation system is much more flexible than the superstructure. Thus, in this work, the explicit conditionally stable central difference method is used to evaluate the base isolation system nonlinear response and the implicit unconditionally stable Newmark’s constant average acceleration method is adopted to predict the superstructure linear response with the benefit in avoiding iterations in each time step of a nonlinear dynamic analysis. The proposed mathematical model is able to simulate the dynamic behavior of seismic isolators without requiring the solution of a nonlinear differential equation, as in the case of widely used differential equation model. The proposed mixed explicit-implicit time integration method and nonlinear exponential model are adopted to analyze a three dimensional seismically isolated structure with a lead rubber bearing system subjected to earthquake excitation. The numerical results show the good accuracy and the significant computational efficiency of the proposed solution approach and analytical model compared to the conventional solution method and mathematical model adopted in this work. Furthermore, the low stiffness value of the base isolation system with lead rubber bearings allows to have a critical time step considerably larger than the imposed ground acceleration time step, thus avoiding stability problems in the proposed mixed method.
Keywords: Base-isolated structures, earthquake engineering, mixed time integration, nonlinear exponential model.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15471226 An Experimental Study on the Tensile Behavior of the Cracked Aluminum Plates Repaired with FML Composite Patches
Authors: A. Pourkamali Anaraki, G. H. Payganeh, F. Ashena ghasemi, A. Fallah
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Repairing of the cracks by fiber metal laminates (FMLs) was first done by some aeronautical laboratories in early 1970s. In this study, experimental investigations were done on the effect of repairing the center-cracked aluminum plates using the FML patches. The repairing processes were conducted to characterize the response of the repaired structures to tensile tests. The composite patches were made of one aluminum layer and two woven glassepoxy composite layers. Three different crack lengths in three crack angles and different patch lay-ups were examined. It was observed for the lengthen cracks, the effect of increasing the crack angle on ultimate tensile load in the structure was increase. It was indicated that the situation of metal layer in the FML patches had an important effect on the tensile response of the tested specimens. It was found when the aluminum layer is farther, the ultimate tensile load has the highest amount.Keywords: Crack, Composite patch repair, Fiber metal laminate (FML), Patch Lay-up, Repair surface, Ultimate load
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18141225 Evaluation of Droplet Sizes from Video Images for Metal Working Fluids
Authors: R. Hacıoğlu, A. Genç, B. Bakırcı
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Metal working fluids were used in the preparation of oil in water emulsions. The size of oil droplets were evaluated by using the analysis of video images taken from the zeta potential measurements. The evaluated size distributions for emulsions were also tested by microscopic analysis. In addition, emulsion stabilities were discussed depending on electrolyte concentration and pH. The results showed that the stability of oil emulsions was strongly related to pH and the concentration of CaCl2. However, the same dependency was not observed for NaCl.
Keywords: Droplet size distribution, emulsion stability, o/w emulsions, video images.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18041224 Rank-Based Chain-Mode Ensemble for Binary Classification
Authors: Chongya Song, Kang Yen, Alexander Pons, Jin Liu
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In the field of machine learning, the ensemble has been employed as a common methodology to improve the performance upon multiple base classifiers. However, the true predictions are often canceled out by the false ones during consensus due to a phenomenon called “curse of correlation” which is represented as the strong interferences among the predictions produced by the base classifiers. In addition, the existing practices are still not able to effectively mitigate the problem of imbalanced classification. Based on the analysis on our experiment results, we conclude that the two problems are caused by some inherent deficiencies in the approach of consensus. Therefore, we create an enhanced ensemble algorithm which adopts a designed rank-based chain-mode consensus to overcome the two problems. In order to evaluate the proposed ensemble algorithm, we employ a well-known benchmark data set NSL-KDD (the improved version of dataset KDDCup99 produced by University of New Brunswick) to make comparisons between the proposed and 8 common ensemble algorithms. Particularly, each compared ensemble classifier uses the same 22 base classifiers, so that the differences in terms of the improvements toward the accuracy and reliability upon the base classifiers can be truly revealed. As a result, the proposed rank-based chain-mode consensus is proved to be a more effective ensemble solution than the traditional consensus approach, which outperforms the 8 ensemble algorithms by 20% on almost all compared metrices which include accuracy, precision, recall, F1-score and area under receiver operating characteristic curve.
Keywords: Consensus, curse of correlation, imbalanced classification, rank-based chain-mode ensemble.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6901223 Study of the Transport of Multivalent Metal Cations through Cation-Exchange Membranes by Electrochemical Impedance Spectroscopy
Authors: V. Pérez-Herranz, M. Pinel, E. M. Ortega, M. García-Gabaldón
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In the present work, Electrochemical Impedance Spectrocopy (EIS) is applied to study the transport of different metal cations through a cation-exchange membrane. This technique enables the identification of the ionic-transport characteristics and to distinguish between different transport mechanisms occurring at different current density ranges. The impedance spectra are dependent on the applied dc current density, on the type of cation and on the concentration. When the applied dc current density increases, the diameter of the impedance spectra loops increases because all the components of membrane system resistance increase. The diameter of the impedance plots decreases in the order of Na(I), Ni(II) and Cr(III) due to the increased interactions between the negatively charged sulfonic groups of the membrane and the cations with greater charge. Nyquist plots are shifted towards lower values of the real impedance, and its diameter decreases with the increase of concentration due to the decrease of the solution resistance.
Keywords: Ion-exchange Membranes, Electrochemical Impedance Espectroscopy, Multivalent Metal Cations.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18551222 Heavy Metal Concentration in Gills and Bones of Tilapia (Oreochromis niloticus) from Jega River, Kebbi State, Nigeria
Authors: D. Y. Bawa, M. I. Ribah, I. S. Jega, V. O. Oyedepo
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A study was conducted to assess some heavy metal concentration (Cadmium (Cd), Copper (Cu), Iron (Fe), Lead (Pb) and Zinc (Zn)) in the gills and bones of Oreochromis niloticus obtained from Jega river. 30 fish samples were collected from March to July 2014 (fortnightly). Bones and gills were used for the assessment of some heavy metals using Atomic Absorption Spectrometer. Results indicated that Pb was not detected in both gills and bones but Fe, Cd, Zn and Cu were present in both the gills and bones of the fish samples. The concentrations of heavy metals in gills were; Fe 3.37±1.10, Cd 0.62±0.08, Zn 6.21±0.11 and Cu 1.28±0.10 mg/kg. The concentrations of heavy metals in bones: Fe 13.08±1.00 mg/kg, Cd 0.99±0.06 mg/kg, Zn 1.28±0.10 mg/kg and Cu 2.23±0.20 mg/kg. The results were found to be within the internationally acceptable standard limits. However, the consumption of small amounts of the identified heavy metals in fish could lead to gradual accumulation over a long period of time and exert toxic effects to consumers. Efforts should be made by the Government to provide appropriate channels for waste disposal to reduce impact on fish.
Keywords: Gills and bones, heavy metal concentration, Jega river, Oreochromis niloticus.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7271221 Time and Cost Efficiency Analysis of Quick Die Change System on Metal Stamping Industry
Authors: Rudi Kurniawan Arief
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Manufacturing cost and setup time are the hot topics to improve in Metal Stamping industry because material and components price are always rising up while costumer requires to cut down the component price year by year. The Single Minute Exchange of Die (SMED) is one of many methods to reduce waste in stamping industry. The Japanese Quick Die Change (QDC) dies system is one of SMED systems that could reduce both of setup time and manufacturing cost. However, this system is rarely used in stamping industries. This paper will analyze how deep the QDC dies system could reduce setup time and the manufacturing cost. The research is conducted by direct observation, simulating and comparing of QDC dies system with conventional dies system. In this research, we found that the QDC dies system could save up to 35% of manufacturing cost and reduce 70% of setup times. This simulation proved that the QDC die system is effective for cost reduction but must be applied in several parallel production processes.
Keywords: Press die, metal stamping, quick die change, QDC system, single minute exchange die, manufacturing cost saving, SMED.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11641220 Bacteriological Screening and Antibiotic – Heavy Metal Resistance Profile of the Bacteria Isolated from Some Amphibian and Reptile Species of the Biga Stream in Turkey
Authors: Nurcihan Hacioglu, Cigdem Gul, Murat Tosunoglu
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In this article, the antibiogram and heavy metal resistance profile of the bacteria isolated from total 34 studied animals (Pelophylax ridibundus = 12; Mauremys rivulata = 14; Natrix natrix = 8) captured around the Biga Stream, are described. There was no database information on antibiogram and heavy metal resistance profile of bacteria from these area’s amphibians and reptiles. A total of 200 bacteria were successfully isolated from cloaca and oral samples of the aquatic amphibians and reptiles as well as from the water sample. According to Jaccard’s similarity index, the degree of similarity in the bacterial flora was quite high among the amphibian and reptile species under examination, whereas it was different from the bacterial diversity in the water sample. The most frequent isolates were A. hydrophila (31.5%), B. pseudomallei (8.5%), and C. freundii (7%). The total numbers of bacteria obtained were as follows: 45 in P. ridibundus, 45 in N. natrix 30 in M. rivulata, and 80 in the water sample. The result showed that cefmetazole was the most effective antibiotic to control the bacteria isolated in this study and that approximately 93.33% of the bacterial isolates were sensitive to this antibiotic. The multiple antibiotic resistances (MAR) index indicated that P. ridibundus (0.95) > N. natrix (0.89) > M. rivulata (0.39). Furthermore, all the tested heavy metals (Pb+2, Cu+2, Cr+3, and Mn+2) inhibit the growth of the bacterial isolates at different rates. Therefore, it indicated that the water source of the animals was contaminated with both antibiotic residues and heavy metals.
Keywords: Amphibian, Bacteriological Quality, Reptile, Antibiotic & Heavy Metal Resistance.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22111219 Association Rule and Decision Tree based Methodsfor Fuzzy Rule Base Generation
Authors: Ferenc Peter Pach, Janos Abonyi
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This paper focuses on the data-driven generation of fuzzy IF...THEN rules. The resulted fuzzy rule base can be applied to build a classifier, a model used for prediction, or it can be applied to form a decision support system. Among the wide range of possible approaches, the decision tree and the association rule based algorithms are overviewed, and two new approaches are presented based on the a priori fuzzy clustering based partitioning of the continuous input variables. An application study is also presented, where the developed methods are tested on the well known Wisconsin Breast Cancer classification problem. Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22561218 Sensitive Detection of Nano-Scale Vibrations by the Metal-Coated Fiber Tip at the Liquid-Air Interface
Authors: A. J. Babajanyan, T. A. Abrahamyan, H. A. Minasyan, Kh. V. Nerkararyan
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Optical radiation emitted from a metal-coated fiber tip apex at liquid-air interface was measured. The intensity of the output radiation was strongly depend on the relative position of the tip to a liquid-air interface and varied with surface fluctuations. This phenomenon permits in-situ real-time investigation of nano-metric vibrations of the liquid surface and provides a basis for development of various origin ultrasensitive vibration detecting sensors. The described method can be used for detection of week seismic vibrations.
Keywords: Fiber-tip, Liquid-air interface, Nano vibration, Opto-mechanical sensor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15241217 The Effects of Wood Ash on Ignition Point of Wood
Authors: Kenneth A. Ibe, Justina I. Mbonu, Godgift K. Umukoro
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The effects of wood ash from five common tropical woods on the ignition point of four common tropical woods in Nigeria were investigated. The ash and moisture contents of the wood sawdust from Mahogany (Khaya ivorensis), Opepe (Sarcocephalus latifolius), Abura (Mitragyna ciliata), Rubber (Heavea brasilensis) and Poroporo (Sorghum bicolour) used, were determined using a furnace (Vecstar furnaces, model ECF2, serial no. f3077) and oven (Genlab laboratory oven, model MINO/040) respectively. The metal contents of the five wood sawdust ash samples were determined using a Perkin Elmer optima 3000 dv atomic absorption spectrometer while the ignition points were determined using Vecstar furnaces model ECF2. Poroporo had the highest ash content, 2.263g while rubber had the least, 0.710g. The results for the moisture content range from 2.971g to 0.903g. Magnesium metal had the highest concentration of all the metals, in all the wood ash samples; with mahogany ash having the highest concentration, 9.196ppm while rubber ash had the least concentration of magnesium metal, 2.196 ppm. The ignition point results showed that the wood ashes from mahogany and opepe increased the ignition points of the test wood samples, Danta (Nesogordonia papaverifera), Ekpaya, Akomu (Pycnanthus angolensis) and Oleku when coated on them while the ashes from poroporo, rubber and abura decreased the ignition points of the test wood samples when coated on them. However, Opepe saw dust ash decreased the ignition point in one of the test wood samples, suggesting that the metal content of the test wood sample was more than that of the Opepe saw dust ash. Therefore, Mahogany and Opepe saw dust ashes could be used in the surface treatment of wood to enhance their fire resistance or retardancy. However, the caution to be exercised in this application is that the metal content of the test wood samples should be evaluated as well.Keywords: Ash, fire, ignition point, retardant, wood saw dust.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18891216 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 29831215 Research of Concentratibility of Low Quality Bauxite Raw Materials
Authors: Nadezhda Nikolaeva, Tatyana Alexandrova, Alexandr Alexandrov
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Processing of high-silicon bauxite on the base of the traditional clinkering method is related to high power consumption and capital investments, which makes production of alumina from those ores non-competitive in terms of basic economic showings. For these reasons, development of technological solutions enabling to process bauxites with various chemical and mineralogical structures efficiently with low level of thermal power consumption is important. Flow sheet of the studies on washability of ores from the Timanskoe and the Severo-Onezhskoe deposits is on the base of the flotation method.Keywords: Low-quality bauxite, resource-saving technology, optimization, aluminum, conditioning of composition, separation characteristics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19151214 Sorption of Nickel by Hypnea Valentiae: Application of Response Surface Methodology
Authors: M. Rajasimman, K. Murugaiyan
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In this work, sorption of nickel from aqueous solution on hypnea valentiae, red macro algae, was investigated. Batch experiments have been carried out to find the effect of various parameters such as pH, temperature, sorbent dosage, metal concentration and contact time on the sorption of nickel using hypnea valentiae. Response surface methodology (RSM) is employed to optimize the process parameters. Based on the central composite design, quadratic model was developed to correlate the process variables to the response. The most influential factor on each experimental design response was identified from the analysis of variance (ANOVA). The optimum conditions for the sorption of nickel were found to be: pH – 5.1, temperature – 36.8oC, sorbent dosage – 5.1 g/L, metal concentration – 100 mg/L and contact time – 30 min. At these optimized conditions the maximum removal of nickel was found to be 91.97%. A coefficient of determination R2 value 0.9548 shows the fitness of response surface methodology in this work.
Keywords: Optimization, metal, Hypnea valentia, response surface methodology, red algae.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16311213 Experimental Study on the Creep Characteristics of FRC Base for Composite Pavement System
Authors: Woo-tai Jung, Sung-yong Choi, Young-hwan Park
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The composite pavement system considered in this paper is composed of a functional surface layer, a fiber reinforced asphalt middle layer and a fiber reinforced lean concrete base layer. The mix design of the fiber reinforced lean concrete corresponds to the mix composition of conventional lean concrete but reinforced by fibers. The quasi-absence of research on the durability or long-term performances (fatigue, creep, etc.) of such mix design stresses the necessity to evaluate experimentally the long-term characteristics of this layer composition. This study tests the creep characteristics as one of the long-term characteristics of the fiber reinforced lean concrete layer for composite pavement using a new creep device. The test results reveal that the lean concrete mixed with fiber reinforcement and fly ash develops smaller creep than the conventional lean concrete. The results of the application of the CEB-FIP prediction equation indicate that a modified creep prediction equation should be developed to fit with the new mix design of the layer.
Keywords: Creep, Lean concrete, Pavement, Fiber reinforced concrete, Base.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21791212 Experimental Study on the Creep Characteristics of FRC Base for Composite Pavement System
Authors: Woo-Tai Jung, Sung-Yong Choi, Young-Hwan Park
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The composite pavement system considered in this paper is composed of a functional surface layer, a fiber reinforced asphalt middle layer and a fiber reinforced lean concrete base layer. The mix design of the fiber reinforced lean concrete corresponds to the mix composition of conventional lean concrete but reinforced by fibers. The quasi-absence of research on the durability or long-term performances (fatigue, creep, etc.) of such mix design stresses the necessity to evaluate experimentally the long-term characteristics of this layer composition. This study tests the creep characteristics as one of the long-term characteristics of the fiber reinforced lean concrete layer for composite pavement using a new creep device. The test results reveal that the lean concrete mixed with fiber reinforcement and fly ash develops smaller creep than the conventional lean concrete. The results of the application of the CEB-FIP prediction equation indicate that a modified creep prediction equation should be developed to fit with the new mix design of the layer.
Keywords: Creep, Lean concrete, Pavement, Fiber reinforced concrete, Base.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13341211 Objective Assessment of Psoriasis Lesion Thickness for PASI Scoring using 3D Digital Imaging
Authors: M.H. Ahmad Fadzil, Hurriyatul Fitriyah, Esa Prakasa, Hermawan Nugroho, S.H. Hussein, Azura Mohd. Affandi
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Psoriasis is a chronic inflammatory skin condition which affects 2-3% of population around the world. Psoriasis Area and Severity Index (PASI) is a gold standard to assess psoriasis severity as well as the treatment efficacy. Although a gold standard, PASI is rarely used because it is tedious and complex. In practice, PASI score is determined subjectively by dermatologists, therefore inter and intra variations of assessment are possible to happen even among expert dermatologists. This research develops an algorithm to assess psoriasis lesion for PASI scoring objectively. Focus of this research is thickness assessment as one of PASI four parameters beside area, erythema and scaliness. Psoriasis lesion thickness is measured by averaging the total elevation from lesion base to lesion surface. Thickness values of 122 3D images taken from 39 patients are grouped into 4 PASI thickness score using K-means clustering. Validation on lesion base construction is performed using twelve body curvature models and show good result with coefficient of determinant (R2) is equal to 1.Keywords: 3D digital imaging, base construction, PASI, psoriasis lesion thickness.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24251210 Evaluation of Traditional Methods in Construction and Their Effects on Reinforced-Concrete Buildings Behavior
Authors: E. H. N. Gashti, M. Zarrini, M. Irannezhad, J. R. Langroudi
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Using ETABS software, this study analyzed 23 buildings to evaluate effects of mistakes during construction phase on buildings structural behavior. For modelling, two different loadings were assumed: 1) design loading and 2) loading due to the effects of mistakes in construction phase. Research results determined that considering traditional construction methods for buildings resulted in a significant increase in dead loads and consequently intensified the displacements and base-shears of buildings under seismic loads.
Keywords: Reinforced-concrete buildings, Construction mistakes, Base-shear, displacements, Failure.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26341209 Effect of Gating Sprue Height on Mechanical Properties of Thin Wall Ductile Iron
Authors: E. F. Ochulor, S. O. Adeosun, S. A. Balogun
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Effect of sprue/metal head height on mould filling, microstructure and mechanical properties of TWDI casting is studied. Results show that metal/sprue height of 50 mm is not sufficient to push the melt through the gating channel, but as it is increased from 100-350 mm, proper mould filling is achieved. However at higher heights between 200 mm and 350 mm, defects associated with incomplete solidification, carbide precipitation and turbulent flow are evident. This research shows that superior UTS, hardness, nodularity and nodule count are obtained at 100 mm sprue height.Keywords: Melt pressure and velocity, nodularity, nodule count, sprue height.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28731208 Removal of Elemental Mercury from Dry Methane Gas with Manganese Oxides
Authors: Junya Takenami, Md. Azhar Uddin, Eiji Sasaoka, Yasushi Shioya, Tsuneyoshi Takase
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In this study, we sought to investigate the mercury removal efficiency of manganese oxides from natural gas. The fundamental studies on mercury removal with manganese oxides sorbents were carried out in a laboratory scale fixed bed reactor at 30 °C with a mixture of methane (20%) and nitrogen gas laden with 4.8 ppb of elemental mercury. Manganese oxides with varying surface area and crystalline phase were prepared by conventional precipitation method in this study. The effects of surface area, crystallinity and other metal oxides on mercury removal efficiency were investigated. Effect of Ag impregnation on mercury removal efficiency was also investigated. Ag supported on metal oxide such titania and zirconia as reference materials were also used in this study for comparison. The characteristics of mercury removal reaction with manganese oxide was investigated using a temperature programmed desorption (TPD) technique. Manganese oxides showed very high Hg removal activity (about 73-93% Hg removal) for first time use. Surface area of the manganese oxide samples decreased after heat-treatment and resulted in complete loss of Hg removal ability for repeated use after Hg desorption in the case of amorphous MnO2, and 75% loss of the initial Hg removal activity for the crystalline MnO2. Mercury desorption efficiency of crystalline MnO2 was very low (37%) for first time use and high (98%) after second time use. Residual potassium content in MnO2 may have some effect on the thermal stability of the adsorbed Hg species. Desorption of Hg from manganese oxides occurs at much higher temperatures (with a peak at 400 °C) than Ag/TiO2 or Ag/ZrO2. Mercury may be captured on manganese oxides in the form of mercury manganese oxide.Keywords: Mercury removal, Metal and metal oxide sorbents, Methane, Natural gas.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20711207 The Sublimation Energy of Metal versus Temperature and Pressure and its Influence on Blow-off Impulse
Authors: Wenhui Tang, Daorong Wang, Xia Huang, Xianwen Ran
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Based on the thermodynamic theory, the dependence of sublimation energy of metal on temperature and pressure is discussed, and the results indicate that the sublimation energy decreases linearly with the increase of temperature and pressure. Combined with this result, the blow-off impulse of aluminum induced by pulsed X-ray is simulated by smoothed particle hydrodynamics (SPH) method. The numerical results show that, while the change of sublimation energy with temperature and pressure is considered, the blow-off impulse of aluminum is larger than the case that the sublimation energy is assumed to be a constant.Keywords: sublimation energy, blow-off impulse, pulsed X-ray, SPH method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28701206 Hybrid GA Tuned RBF Based Neuro-Fuzzy Controller for Robotic Manipulator
Authors: Sufian Ashraf Mazhari, Surendra Kumar
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In this paper performance of Puma 560 manipulator is being compared for hybrid gradient descent and least square method learning based ANFIS controller with hybrid Genetic Algorithm and Generalized Pattern Search tuned radial basis function based Neuro-Fuzzy controller. ANFIS which is based on Takagi Sugeno type Fuzzy controller needs prior knowledge of rule base while in radial basis function based Neuro-Fuzzy rule base knowledge is not required. Hybrid Genetic Algorithm with generalized Pattern Search is used for tuning weights of radial basis function based Neuro- fuzzy controller. All the controllers are checked for butterfly trajectory tracking and results in the form of Cartesian and joint space errors are being compared. ANFIS based controller is showing better performance compared to Radial Basis Function based Neuro-Fuzzy Controller but rule base independency of RBF based Neuro-Fuzzy gives it an edge over ANFISKeywords: Neuro-Fuzzy, Robotic Control, RBFNF, ANFIS, Hybrid GA.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20741205 Fixture Layout Optimization for Large Metal Sheets Using Genetic Algorithm
Authors: Zeshan Ahmad, Matteo Zoppi, Rezia Molfino
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The geometric errors in the manufacturing process can be reduced by optimal positioning of the fixture elements in the fixture to make the workpiece stiff. We propose a new fixture layout optimization method N-3-2-1 for large metal sheets in this paper that combines the genetic algorithm and finite element analysis. The objective function in this method is to minimize the sum of the nodal deflection normal to the surface of the workpiece. Two different kinds of case studies are presented, and optimal position of the fixturing element is obtained for different cases.
Keywords: Fixture layout, optimization, fixturing element, genetic algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22531204 One-Pot Synthesis and Characterization of Magnesium Oxide Nanoparticles Prepared by Calliandra calothyrsus Leaf Extract
Authors: Indah Kurniawaty, Yoki Yulizar, Haryo Satrya Oktaviano, Adam Kusuma Rianto
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Magnesium oxide nanoparticles (MgO NP) were successfully synthesized in this study using a one-pot green synthesis mediated by Calliandra calothyrsus leaf extract (CLE). CLE was prepared by maceration of the leaf using methanol with a ratio of 1:5 for 7 days. Secondary metabolites in CLE, such as alkaloids and flavonoids, served as a weak base provider and capping agent in the formation of MgO NP. CLE Fourier Transform Infra-Red (FTIR) spectra peak at 3255 cm-1, 1600 cm-1, 1384 cm-1, 1205 cm-1, 1041 cm-1, and 667 cm-1 showing the presence of vibrations O-H stretching, N-H bending, C-C stretching, C-N stretching and N-H wagging. During the experiment, different CLE volumes and calcined temperatures were used, resulting in a variety of structures. Energy Dispersive X-ray Spectrometer (EDS) and FTIR were used to characterize metal oxide particles. MgO diffraction patterns at 2θ of 36.9°; 42.9°; 62.2°; 74.6°; and 78.5° can be assigned to crystal planes (111), (200), (220), (311), and (222), respectively. Scanning Electron Microscopy (SEM) was used to characterize the surface morphology. The morphology ranged from sphere to flower-like resulting in crystallite sizes of 28 nm, 23 nm, 12 nm, and 9 nm.
Keywords: Calliandra calothyrsus, green-synthesis, magnesium oxide, nanoparticle.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1171203 Rheological Properties of Polyethylene and Polypropylene Modified Bitumen
Authors: Noor Zainab Habib, Ibrahim Kamaruddin, Madzalan Napiah, Isa Mohd Tan
Abstract:
This paper presents a part of research on the rheological properties of bitumen modified by thermoplastic namely linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and polypropylene (PP) and its interaction with 80 pen base bitumen. As it is known that the modification of bitumen by the use of polymers enhances its performance characteristics but at the same time significantly alters its rheological properties. The rheological study of polymer modified bitumen (PMB) was made through penetration, ring & ball softening point and viscosity test. The results were then related to the changes in the rheological properties of polymer modified bitumen. It was observed that thermoplastic copolymer shows profound effect on penetration rather than softening point. The viscoelastic behavior of polymer modified bitumen depend on the concentration of polymer, mixing temperature, mixing technique, solvating power of base bitumen and molecular structure of polymer used. PP offer better blend in comparison to HDPE and LLDPE. The viscosity of base bitumen was also enhanced with the addition of polymer. The pseudoplastic behavior was more prominent for HDPE and LLDPE than PP. Best results were obtained when polymer concentration was kept below 3%Keywords: Polymer modified bitumen, Linear low densitypolyethylene, High density polyethylene, Polypropylene.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 43941202 Evaluate Aging Effect of SBS Modified Bitumen
Authors: Seyed Abbas Tabatabaei
Abstract:
One of the important factors of cracks on the asphalt pavements is bitumen aging that associated with the loss of volatile components and oxidation of asphalt binder. This paper is about effect of Styrene-Butadiene-Styrene (SBS) polymer on asphalt aging In order to decrease asphalt aging effects. For this purpose samples of base bitumen and SBS modified bitumen aged according to the rolling thin film oven test (RTFOT) and pressure aging vessel (PAV), respectively. Properties of each sample were evaluated using Fourier Transform Infrared (FTIR) spectroscopy, n-heptane precipitation, viscosity test, softening point test and penetration test. FT-IR Analysis, showed lower oxidation of SBS modified bitumen than base bitumen, after aging.Keywords: SBS, Asphalt aging, modified bitumen.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 31151201 3D Numerical Investigation of Asphalt Pavements Behaviour Using Infinite Elements
Authors: K. Sandjak, B. Tiliouine
Abstract:
This article presents the main results of three-dimensional (3-D) numerical investigation of asphalt pavement structures behaviour using a coupled Finite Element-Mapped Infinite Element (FE-MIE) model. The validation and numerical performance of this model are assessed by confronting critical pavement responses with Burmister’s solution and FEM simulation results for multi-layered elastic structures. The coupled model is then efficiently utilised to perform 3-D simulations of a typical asphalt pavement structure in order to investigate the impact of two tire configurations (conventional dual and new generation wide-base tires) on critical pavement response parameters. The numerical results obtained show the effectiveness and the accuracy of the coupled (FE-MIE) model. In addition, the simulation results indicate that, compared with conventional dual tire assembly, single wide base tire caused slightly greater fatigue asphalt cracking and subgrade rutting potentials and can thus be utilised in view of its potential to provide numerous mechanical, economic, and environmental benefits.
Keywords: Infinite elements, 3-D numerical investigation, asphalt pavements, dual and wide base tires.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 684