Search results for: curing time effect
10095 Assessment of Channel Unavailability Effect on the Wireless Networks Teletraffic Modeling and Analysis
Authors: Eman S. El-Din, Hesham M. El-Badawy, Salwa H. Elramly
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Whereas cellular wireless communication systems are subject to short-and long-term fading. The effect of wireless channel has largely been ignored in most of the teletraffic assessment researches. In this paper, a mathematical teletraffic model is proposed to estimate blocking and forced termination probabilities of cellular wireless networks as a result of teletraffic behavior as well as the outage of the propagation channel. To evaluate the proposed teletraffic model, gamma inter-arrival and general service time distributions have been considered based on wireless channel fading effect. The performance is evaluated and compared with the classical model. The proposed model is dedicated and investigated in different operational conditions. These conditions will consider not only the arrival rate process, but also, the different faded channels models.Keywords: Cellular wireless networks, outage probability, traffic model, gamma inter-arrival distribution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 149510094 Social Media Research and Its Effect on Our Society
Authors: A. T. M Shahjahan, Kutub Uddin Chisty
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Social media refers to the means of interactions among people in which they create share, exchange and comment contents among themselves in virtual communities and networks. Social media or "social networking" has almost become part of our daily lives and being tossed around over the past few years. It is like any other media such as newspaper, radio and television but it is far more than just about sharing information and ideas. Social networking tools like Twitter, Facebook, Flickr and Blogs have facilitated creation and exchange of ideas so quickly and widely than the conventional media. This paper shows the choices, communication, feeling comfort, time saving and effects of social media among the people.
Keywords: Media, Choice, Effect.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1837010093 A Methodology for Reducing the BGP Convergence Time
Authors: Eatedal A. Alabdulkreem, Hamed S. Al-Raweshidy, Maysam F. Abbod
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Border Gateway Protocol (BGP) is the standard routing protocol between various autonomous systems (AS) in the internet. In the event of failure, a considerable delay in the BGP convergence has been shown by empirical measurements. During the convergence time the BGP will repeatedly advertise new routes to some destination and withdraw old ones until it reach a stable state. It has been found that the KEEPALIVE message timer and the HOLD time are tow parameters affecting the convergence speed. This paper aims to find the optimum value for the KEEPALIVE timer and the HOLD time that maximally reduces the convergence time without increasing the traffic. The KEEPALIVE message timer optimal value founded by this paper is 30 second instead of 60 seconds, and the optimal value for the HOLD time is 90 seconds instead of 180 seconds.
Keywords: BGP, Convergence Time, HOLD time, Keep alive.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 204310092 A Novel Digital Calibration Technique for Gain and Offset Mismatch in TIΣΔ ADCs
Authors: Ali Beydoun, Van-Tam Nguyen, Patrick Loumeau
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Time interleaved sigma-delta (TIΣΔ) architecture is a potential candidate for high bandwidth analog to digital converters (ADC) which remains a bottleneck for software and cognitive radio receivers. However, the performance of the TIΣΔ architecture is limited by the unavoidable gain and offset mismatches resulting from the manufacturing process. This paper presents a novel digital calibration method to compensate the gain and offset mismatch effect. The proposed method takes advantage of the reconstruction digital signal processing on each channel and requires only few logic components for implementation. The run time calibration is estimated to 10 and 15 clock cycles for offset cancellation and gain mismatch calibration respectively.Keywords: sigma-delta, calibration, gain and offset mismatches, analog-to-digital conversion, time-interleaving.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 552810091 The Effect of Increment in Simulation Samples on a Combined Selection Procedure
Authors: Mohammad H. Almomani, Rosmanjawati Abdul Rahman
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Statistical selection procedures are used to select the best simulated system from a finite set of alternatives. In this paper, we present a procedure that can be used to select the best system when the number of alternatives is large. The proposed procedure consists a combination between Ranking and Selection, and Ordinal Optimization procedures. In order to improve the performance of Ordinal Optimization, Optimal Computing Budget Allocation technique is used to determine the best simulation lengths for all simulation systems and to reduce the total computation time. We also argue the effect of increment in simulation samples for the combined procedure. The results of numerical illustration show clearly the effect of increment in simulation samples on the proposed combination of selection procedure.Keywords: Indifference-Zone, Optimal Computing Budget Allocation, Ordinal Optimization, Ranking and Selection, Subset Selection.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 124210090 Ambipolar Effect Free Double Gate PN Diode Based Tunnel FET
Authors: Hardik Vaghela, Mamta Khosla, Balwindar Raj
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In this paper, we present and investigate a double gate PN diode based tunnel field effect transistor (DGPNTFET). The importance of proposed structure is that the formation of different drain doping is not required and ambipolar effect in OFF state is completely removed for this structure. Validation of this structure to behave like a Tunnel Field Effect Transistor (TFET) is carried out through energy band diagrams and transfer characteristics. Simulated result shows point subthreshold slope (SS) of 19.14 mV/decade and ON to OFF current ratio (ION / IOFF) of 2.66 × 1014 (ION at VGS=1.5V, VDS=1V and IOFF at VGS=0V, VDS=1V) for gate length of 20nm and HfO2 as gate oxide at room temperature. Which indicate that the DGPNTFET is a promising candidate for nano-scale, ambipolar free switch.
Keywords: Ambipolar effect, double gate PN diode based tunnel field effect transistor, high-κ dielectric material, subthreshold slope, tunnel field effect transistor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 100810089 Effective Design Parameters on the End Effect in Single-Sided Linear Induction Motors
Authors: A. Zare Bazghaleh, M. R. Naghashan, H. Mahmoudimanesh, M. R. Meshkatoddini
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Linear induction motors are used in various industries but they have some specific phenomena which are the causes for some problems. The most important phenomenon is called end effect. End effect decreases efficiency, power factor and output force and unbalances the phase currents. This phenomenon is more important in medium and high speeds machines. In this paper a factor, EEF , is obtained by an accurate equivalent circuit model, to determine the end effect intensity. In this way, all of effective design parameters on end effect is described. Accuracy of this equivalent circuit model is evaluated by two dimensional finite-element analysis using ANSYS. The results show the accuracy of the equivalent circuit model.Keywords: Linear induction motor, end effect, equivalent circuitmodel, finite-element method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 279310088 Impact of Some Experimental Procedures on Behavioral Patterns and Physiological Traits of Rats
Authors: Amira, A. Goma, U. E. Mahrous
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Welfare may be considered to be a subjective experience; it has a biological function that is related to the fitness and survival of the animal accordingly, researches have suggested that welfare is compromised when the animal's evolutionary fitness is reduced. This study was carried out to explain the effect of some managerial stressors as handling and restraint on behavioral patterns and biochemical parameters of rats. A total of 24 (12 males & 12 females) Sprague-Dawley rats (12 months & 150-180g) were allotted into 3 groups, handled group (4 male & 4 female), restrained group (4 male & 4 female) and control group (4 males & 4 females). The obtained results revealed that time spent feeding, drinking, movement and cage exploration frequencies increased significantly in handled rats than other groups, while lying time and licking increased significantly in restrained rats than handled and controls. Moreover, social behavior decreased in both stressed groups than control. Triglycerides were significantly increased in handled rats than other groups, while total lipid, total protein and globulin significantly increased in both treated groups than control. Corticosterone increased in restrained and handled rats than control ones. Moreover, there was an increment in packed cell volume significantly in restrained rats than others. These deducted that if we want to study the effect of stress on animal welfare it is necessary to study the effect of such stressors on animal’s behavior and physiological responses.
Keywords: Behavior, handling, restraint, rat, welfare.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 226110087 Conjugate Heat and Mass Transfer for MHD Mixed Convection with Viscous Dissipation and Radiation Effect for Viscoelastic Fluid past a Stretching Sheet
Authors: Kai-Long Hsiao, BorMing Lee
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In this study, an analysis has been performed for conjugate heat and mass transfer of a steady laminar boundary-layer mixed convection of magnetic hydrodynamic (MHD) flow with radiation effect of second grade subject to suction past a stretching sheet. Parameters E Nr, Gr, Gc, Ec and Sc represent the dominance of the viscoelastic fluid heat and mass transfer effect which have presented in governing equations, respectively. The similar transformation and the finite-difference method have been used to analyze the present problem. The conjugate heat and mass transfer results show that the non-Newtonian viscoelastic fluid has a better heat transfer effect than the Newtonian fluid. The free convection with a larger r G or c G has a good heat transfer effect better than a smaller r G or c G , and the radiative convection has a good heat transfer effect better than non-radiative convection.Keywords: Conjugate heat and mass transfer, Radiation effect, Magnetic effect, Viscoelastic fluid, Viscous dissipation, Stretchingsheet.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 168010086 Analysis and Research of Two-Level Scheduling Profile for Open Real-Time System
Authors: Yongxian Jin, Jingzhou Huang
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In an open real-time system environment, the coexistence of different kinds of real-time and non real-time applications makes the system scheduling mechanism face new requirements and challenges. One two-level scheduling scheme of the open real-time systems is introduced, and points out that hard and soft real-time applications are scheduled non-distinctively as the same type real-time applications, the Quality of Service (QoS) cannot be guaranteed. It has two flaws: The first, it can not differentiate scheduling priorities of hard and soft real-time applications, that is to say, it neglects characteristic differences between hard real-time applications and soft ones, so it does not suit a more complex real-time environment. The second, the worst case execution time of soft real-time applications cannot be predicted exactly, so it is not worth while to cost much spending in order to assure all soft real-time applications not to miss their deadlines, and doing that may cause resource wasting. In order to solve this problem, a novel two-level real-time scheduling mechanism (including scheduling profile and scheduling algorithm) which adds the process of dealing with soft real-time applications is proposed. Finally, we verify real-time scheduling mechanism from two aspects of theory and experiment. The results indicate that our scheduling mechanism can achieve the following objectives. (1) It can reflect the difference of priority when scheduling hard and soft real-time applications. (2) It can ensure schedulability of hard real-time applications, that is, their rate of missing deadline is 0. (3) The overall rate of missing deadline of soft real-time applications can be less than 1. (4) The deadline of a non-real-time application is not set, whereas the scheduling algorithm that server 0 S uses can avoid the “starvation" of jobs and increase QOS. By doing that, our scheduling mechanism is more compatible with different types of applications and it will be applied more widely.
Keywords: Hard real-time, two-level scheduling profile, open real-time system, non-distinctive schedule, soft real-time
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 156810085 Compressed Suffix Arrays to Self-Indexes Based on Partitioned Elias-Fano
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A practical and simple self-indexing data structure, Partitioned Elias-Fano (PEF) - Compressed Suffix Arrays (CSA), is built in linear time for the CSA based on PEF indexes. Moreover, the PEF-CSA is compared with two classical compressed indexing methods, Ferragina and Manzini implementation (FMI) and Sad-CSA on different type and size files in Pizza & Chili. The PEF-CSA performs better on the existing data in terms of the compression ratio, count, and locates time except for the evenly distributed data such as proteins data. The observations of the experiments are that the distribution of the φ is more important than the alphabet size on the compression ratio. Unevenly distributed data φ makes better compression effect, and the larger the size of the hit counts, the longer the count and locate time.
Keywords: Compressed suffix array, self-indexing, partitioned Elias-Fano, PEF-CSA.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 108310084 Effect of Fat Percentage and Prebiotic Composition on Proteolysis, ACE-Inhibitory and Antioxidant Activity of Probiotic Yogurt
Authors: Mohammad B. HabibiNajafi, Saeideh Sadat Fatemizadeh, Maryam Tavakoli
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In recent years, the consumption of functional foods, including foods containing probiotic bacteria, has come to notice. Milk proteins have been identified as a source of angiotensin-I-converting enzyme )ACE( inhibitory peptides and are currently the best-known class of bioactive peptides. In this study, the effects of adding prebiotic ingredients (inulin and wheat fiber) and fat percentage (0%, 2% and 3.5%) in yogurt containing probiotic Lactobacillus casei on physicochemical properties, degree of proteolysis, antioxidant and ACE-inhibitory activity within 21 days of storage at 5 ± 1 °C were evaluated. The results of statistical analysis showed that the application of prebiotic compounds led to a significant increase in water holding capacity, proteolysis and ACE-inhibitory of samples. The degree of proteolysis in yogurt increases as storage time elapses (P < 0.05) but when proteolysis exceeds a certain threshold, this trend begins to decline. Also, during storage time, water holding capacity reduced initially but increased thereafter. Moreover, based on our findings, the survival of Lactobacillus casei in samples treated with inulin and wheat fiber increased significantly in comparison to the control sample (P < 0.05) whereas the effect of fat percentage on the survival of probiotic bacteria was not significant (P = 0.095). Furthermore, the effect of prebiotic ingredients and the presence of probiotic cultures on the antioxidant activity of samples was significant (P < 0.05).Keywords: Yogurt, proteolysis, ACE-inhibitory, antioxidant activity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 103610083 Finite Element Analysis of Cooling Time and Residual Strains in Cold Spray Deposited Titanium Particles
Authors: Thanh-Duoc Phan, Saden H. Zahiri, S. H. Masood, Mahnaz Jahedi
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In this article, using finite element analysis (FEA) and an X-ray diffractometer (XRD), cold-sprayed titanium particles on a steel substrate is investigated in term of cooling time and the development of residual strains. Three cooling-down models of sprayed particles after deposition stage are simulated and discussed: the first model (m1) considers conduction effect to the substrate only, the second model (m2) considers both conduction as well as convection effect to the environment, and the third model (m3) which is the same as the second model but with the substrate heated to a near particle temperature before spraying. Thereafter, residual strains developed in the third model is compared with the experimental measurement of residual strains, which involved a Bruker D8 Advance Diffractometer using CuKa radiation (40kV, 40mA) monochromatised with a graphite sample monochromator. For deposition conditions of this study, a good correlation was found to exist between the FEA results and XRD measurements of residual strains.Keywords: cold gas dynamic spray, X-ray diffraction, explicit finite element analysis, residual strain, titanium, particle impact, deformation behavior.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 175610082 Inductance Characteristic of Annealed Titanium Dioxide on Silicon Substrate
Authors: Chih Chin Yang, Lan Hui Huang, Bo Shum Chen, Jia Liang Ke, Chung Lun Tsai
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The control of oxygen flow rate during growth of titanium dioxide by mass flow controller in DC plasma sputtering growth system is studied. The impedance of TiO2 films for inductance effect is influenced by annealing time and oxygen flow rate. As annealing time is increased, the inductance of TiO2 film is the more. The growth condition of optimum and maximum inductance for TiO2 film to serve as sensing device are oxygen flow rate of 15 sccm and large annealing time. The large inductance of TiO2 film will be adopted to fabricate the biosensor to obtain the high sensitivity of sensing in biology.Keywords: Annealed, Inductance, Silicon substarte, Titanium dioxide
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 196510081 Action Functional of the Electomagnetic Field: Effect of Gravitation
Authors: Arti Vaish, Harish Parthasarathy
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The scalar wave equation for a potential in a curved space time, i.e., the Laplace-Beltrami equation has been studied in this work. An action principle is used to derive a finite element algorithm for determining the modes of propagation inside a waveguide of arbitrary shape. Generalizing this idea, the Maxwell theory in a curved space time determines a set of linear partial differential equations for the four electromagnetic potentials given by the metric of space-time. Similar to the Einstein-s formulation of the field equations of gravitation, these equations are also derived from an action principle. In this paper, the expressions for the action functional of the electromagnetic field have been derived in the presence of gravitational field.
Keywords: General theory of relativity, electromagnetism, metric tensor, Maxwells equations, test functions, finite element method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 166110080 Modeling and Analysis of Process Parameters on Surface Roughness in EDM of AISI D2 Tool Steel by RSM Approach
Authors: M. K. Pradhan, C. K. Biswas
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In this research, Response Surface Methodology (RSM) is used to investigate the effect of four controllable input variables namely: discharge current, pulse duration, pulse off time and applied voltage Surface Roughness (SR) of on Electrical Discharge Machined surface. To study the proposed second-order polynomial model for SR, a Central Composite Design (CCD) is used to estimation the model coefficients of the four input factors, which are alleged to influence the SR in Electrical Discharge Machining (EDM) process. Experiments were conducted on AISI D2 tool steel with copper electrode. The response is modeled using RSM on experimental data. The significant coefficients are obtained by performing Analysis of Variance (ANOVA) at 5% level of significance. It is found that discharge current, pulse duration, and pulse off time and few of their interactions have significant effect on the SR. The model sufficiency is very satisfactory as the Coefficient of Determination (R2) is found to be 91.7% and adjusted R2-statistic (R2 adj ) 89.6%.
Keywords: Electrical discharge machining, surface roughness, response surface methodology, ANOVA, central composite design.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 235610079 Measuring the Efficiency of Medical Equipment
Authors: Panagiotis H. Tsarouhas
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the reliability analysis of the medical equipments can help to increase the availability and the efficiency of the systems. In this manuscript we present a simple method of decomposition that could be easily applied on the complex medical systems. Using this method we can easily calculate the effect of the subsystems or components on the reliability of the overall system. Furthermore, to investigate the effect of subsystems or components on system performance, we perform a numerical study varying every time the worst reliability of subsystem or component with another which has higher reliability. It can also be useful to engineers and designers of medical equipment, who wishes to optimize the complex systems.Keywords: Reliability, Availability, Series-parallel System, medical equipment.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 239710078 Adsorption of Lead from Synthetic Solution using Luffa Charcoal
Authors: C. Umpuch, N. Bunmanan, U. Kueasing, P. Kaewsan
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This work was to study batch biosorption of Pb(II) ions from aqueous solution by Luffa charcoal. The effect of operating parameters such as adsorption contact time, initial pH solution and different initial Pb(II) concentration on the sorption of Pb(II) were investigated. The results showed that the adsorption of Pb(II) ions was initially rapid and the equilibrium time was 10 h. Adsorption kinetics of Pb(II) ions onto Luffa charcoal could be best described by the pseudo-second order model. At pH 5.0 was favorable for the adsorption and removal of Pb(II) ions. Freundlich adsorption isotherm model was better fitted for the adsorption of Pb(II) ions than Langmuir and Timkin isotherms, respectively. The highest monolayer adsorption capacity obtained from Langmuir isotherm model was 51.02 mg/g. This study demonstrated that Luffa charcoal could be used for the removal of Pb(II) ions in water treatment.Keywords: Lead (II), Luffa charcoal, Biosorption, initial pHsolution, contact time, adsorption isotherm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 241410077 n-Butanol as an Extractant for Lactic Acid Recovery
Authors: Kanungnit Chawong, Panarat Rattanaphanee
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Extraction of lactic acid from aqueous solution using n-butanol as an extractant was studied. Effect of mixing time, pH of the aqueous solution, initial lactic acid concentration, and volume ratio between the organic and the aqueous phase were investigated. Distribution coefficient and degree of lactic acid extraction was found to increase when the pH of aqueous solution was decreased. The pH Effect was substantially pronounced at pH of the aqueous solution less than 1. Initial lactic acid concentration and organic-toaqueous volume ratio appeared to have positive effect on the distribution coefficient and the degree of extraction. Due to the nature of n-butanol that is partially miscible in water, incorporation of aqueous solution into organic phase was observed in the extraction with large organic-to-aqueous volume ratio.
Keywords: Lactic acid, liquid-liquid extraction, n-Butanol, Solvating extractant.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 317310076 Existence and Uniqueness of Periodic Solution for a Discrete-time SIR Epidemic Model with Time Delays and Impulses
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In this paper, a discrete-time SIR epidemic model with nonlinear incidence rate, time delays and impulses is investigated. Sufficient conditions for the existence and uniqueness of periodic solutions are obtained by using contraction theorem and inequality techniques. An example is employed to illustrate our results.
Keywords: Discrete-time SIR epidemic model, time delay, nonlinear incidence rate, impulse.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 164810075 Effect of Geographical Co-Ordinates on the Parameters in the Rain Rate Model for Radio Propagation Applications
Authors: Olatinwo M. O., Oyeleke Olaosebikan, David Henry O.
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Rain attenuation plays a lot of roles in the design of satellite and terrestrial microwave radio links, hence a good knowledge of its effect is of great interest to Engineers and scientists in that it is often required to give a high level of accuracy of the rainrate distribution that expresses rainrate from the lowest value to the highest. This study proposes a model to express rainrate parameters alpha (α) and beta (β) as a function of geographical location at 0.01% of the time. The tropical locations used in the development of the effect were Ilorin, Ile-Ife, Douala, Dar-es-Selam, Nairobi, Lusaka, and Brazilia.
This expression clearly confirms the variability of rainfall from place to place. When consistency test was carried out using the expression to generate rainrate for each location examined, the result obtained was reliable for rain intensities between 5mm/h and 200mm/h. The variability of α and β with latitude also shows that different latitudes have different cumulative rain distribution. The model proposed in this study would be one of the useful tools to Radio Engineers since the precipitation effect in the design of satellite and terrestrial microwave radio links is among the factors to consider when designing communication systems.
Keywords: Rain rate, attenuation, geographical location.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 171410074 Analyses for Primary Coolant Pump Coastdown Phenomena for Jordan Research and Training Reactor
Authors: Yazan M. Alatrash, Han-ok Kang, Hyun-gi Yoon, Shen Zhang, Juhyeon Yoon
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Flow coastdown phenomena are very important to secure nuclear fuel integrity during loss of off-site power accidents. In this study, primary coolant flow coastdown phenomena are investigated for the Jordan Research and Training Reactor (JRTR) using a simulation software package, Modular Modeling System (MMS). Two MMS models are built. The first one is a simple model to investigate the characteristics of the primary coolant pump only. The second one is a model for a simulation of the Primary Coolant System (PCS) loop, in which all the detailed design data of the JRTR PCS system are modeled, including the geometrical arrangement data. The same design data for a PCS pump are used for both models. Coastdown curves obtained from the two models are compared to study the PCS loop coolant inertia effect on a flow coastdown. Results showed that the loop coolant inertia effect is found to be small in the JRTR PCS loop, i.e., about one second increases in a coastdown half time required to halve the coolant flow rate. The effects of different flywheel inertia on the flow coastdown are also investigated. It is demonstrated that the coastdown half time increases with the flywheel inertia linearly. The designed coastdown half time is proved to be well above the design requirement for the fuel integrity.
Keywords: Flow Coastdown, Loop Coolant Inertia, Modeling, Research Reactor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 379610073 Optimizing the Project Delivery Time with Time Cost Trade-offs
Authors: Wei Lo, Ming-En Kuo
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While to minimize the overall project cost is always one of the objectives of construction managers, to obtain the maximum economic return is definitely one the ultimate goals of the project investors. As there is a trade-off relationship between the project time and cost, and the project delivery time directly affects the timing of economic recovery of an investment project, to provide a method that can quantify the relationship between the project delivery time and cost, and identify the optimal delivery time to maximize economic return has always been the focus of researchers and industrial practitioners. Using genetic algorithms, this study introduces an optimization model that can quantify the relationship between the project delivery time and cost and furthermore, determine the optimal delivery time to maximize the economic return of the project. The results provide objective quantification for accurately evaluating the project delivery time and cost, and facilitate the analysis of the economic return of a project.Keywords: Time-Cost Trade-Off, Genetic Algorithms, Resource Integration, Economic return.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 177410072 Modulation of Lipopolysaccharide Induced Interleukin-17F and Cyclooxygenase-2 Gene Expression by Echinacea purpurea in Broiler Chickens
Authors: Ali Asghar Saki, Sayed Ali Hosseini Siyar, Abbass Ashoori
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This study was conducted to evaluate the effect of Echinacea purpurea on the expression of cyclooxygenase-2 (COX-2), interleukin-17F (IL-17F) in seven-day-old broiler chickens. Four groups were fed with concentration of 0 g/kg, 5 g/kg, 10 g/kg and 20 g/kg from the root of E. purpurea in the basal diet and two other groups were only fed with the basal diet for 21 days. At the 28th day, lipopolysaccharide (LPS, 2 mg/kg diet) was injected in four groups and the basal diet group was injected by saline as control. The chickens’ spleen RNA expression was measured for the COX-2 and IL-17F genes by Real-Time PCR. The results have shown that chickens which were fed E. purpurea had a lower COX-2 and IL-17F mRNA expression. The chickens who have received LPS only, lymphocyte was lower than other treatments. Vital organ weights were not significantly different, but body weight loss was recovered by dietary herbs inclusion. The results of this study have shown the positive effect of an anti-inflammatory herb to prevent the undesirable effect of inflammation.
Keywords: Echinacea purpurea, broiler chickens, gene expression, lipopolysaccharide.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 98810071 Genetic Algorithms Multi-Objective Model for Project Scheduling
Authors: Elsheikh Asser
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Time and cost are the main goals of the construction project management. The first schedule developed may not be a suitable schedule for beginning or completing the project to achieve the target completion time at a minimum total cost. In general, there are trade-offs between time and cost (TCT) to complete the activities of a project. This research presents genetic algorithms (GAs) multiobjective model for project scheduling considering different scenarios such as least cost, least time, and target time.
Keywords: Genetic algorithms, Time-cost trade-off.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 232710070 Transient Hydrodynamic and Thermal Behaviors of Fluid Flow in a Vertical Porous Microchannel under the Effect of Hyperbolic Heat Conduction Model
Authors: A. F. Khadrawi
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The transient hydrodynamics and thermal behaviors of fluid flow in open-ended vertical parallel-plate porous microchannel are investigated semi-analytically under the effect of the hyperbolic heat conduction model. The model that combines both the continuum approach and the possibility of slip at the boundary is adopted in the study. The Effects of Knudsen number , Darcy number , and thermal relaxation time on the microchannel hydrodynamics and thermal behaviors are investigated using the hyperbolic heat conduction models. It is found that as increases the slip in the hydrodynamic and thermal boundary condition increases. This slip in the hydrodynamic boundary condition increases as increases. Also, the slip in the thermal boundary condition increases as decreases especially the early stage of time.Keywords: free convection, hyperbolic heat conduction, macroscopic heat conduction models in microchannel, porous media, vertical microchannel, microchannel thermal, hydrodynamic behavior.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 192710069 Denitrification of Wastewater Containing High Nitrate Using a Bioreactor System Packed by Microbial Cellulose
Authors: H. Godini, A. Rezaee, A. Jafari, S. H. Mirhousaini
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A Laboratory-scale packed bed reactor with microbial cellulose as the biofilm carrier was used to investigate the denitrification of high-strength nitrate wastewater with specific emphasis on the effect the nitrogen loading rate and hydraulic retention time. Ethanol was added as a carbon source for denitrification. As a result of this investigation, it was found that up to 500 mg/l feed nitrate concentration the present system is able to produce an effluent with nitrate content below 10 ppm at 3 h hydraulic retention time. The highest observed denitrification rate was 4.57 kg NO3-N/ (m3 .d) at a nitrate load of 5.64 kg NO3- N/(m3 .d), and removal efficiencies higher than 90% were obtained for loads up to 4.2 kg NO3-N/(m3 .d). A mass relation between COD consumed and NO3-N removed around 2.82 was observed. This continuous-flow bioreactor proved an efficient denitrification system with a relatively low retention time.Keywords: Biological nitrate removal, Denitrification, Microbial cellulose, Packed-bed reactor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 256710068 Assessment of Susceptibility of the Poultry Red Mite, Dermanyssus gallinae (Acari: Dermanyssidae) to Some Plant Preparations with Focus on Exposure Time
Authors: Sh. Ranjbar-Bahadori, N. Farhadifar, L. Mohammadyar
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Plant preparations from thyme and garlic have been shown to be effective acaricides against the poultry red mite, Dermanyssus gallinae. In a layer house with a history of D. gallinae problem, mites were detected in the monitoring traps for the first time and number of them was counted. Then, some rows of layer house was sprayed twice using a concentration of 0.21 mg/cm2 thyme essential oil and 0.07 mg/cm2 garlic juice and a similar row was used as an untreated control group. Red mite traps made of cardboard were used to assess the mite density during days 1 and 7 after treatment and always removed after 24 h. the collected mites were counted and the efficacy against all mite stages (larvae, nymphs and adults) was calculated. Results showed that on day 1 and 7 after the administration of garlic extract efficacy rate was 92.05% and 74.62%, respectively. Moreover, efficacy rate on day 1 and 7 was 89.4% and 95.37% when treatment was done with thyme essential oil. It is concluded that using garlic juice to control of D. gallinae is more effective on short time. But thyme essential oil has a long time effect in compare to garlic preparation.
Keywords: Dermanyssus gallinae, Essential oil, Garlic, Thyme, Efficacy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 377310067 The Effect of the Side-Weir Crest Height to Scour in Clay-Sand Mixed Sediments
Authors: F. Ayça Varol Saraçoğlu, Hayrullah Ağaçcıoğlu
Abstract:
Experimental studies to investigate the depth of the scour conducted at a side-weir intersection located at the 1800 curved flume which located Hydraulic Laboratory of Yıldız Technical University, Istanbul, Turkey. Side weirs were located at the middle of the straight part of the main channel. Three different lengths (25, 40 and 50 cm) and three different weir crest height (7, 10 and 12 cm) of the side weir placed on the side weir station. There is no scour when the material is only kaolin. Therefore, the cohesive bed was prepared by properly mixing clay material (kaolin) with 31% sand in all experiments. Following 24h consolidation time, in order to observe the effect of flow intensity on the scour depth, experiments were carried out for five different upstream Froude numbers in the range of 0.33-0.81. As a result of this study the relation between scour depth and upstream flow intensity as a function of time have been established. The longitudinal velocities decreased along the side weir; towards the downstream due to overflow over the side-weirs. At the beginning, the scour depth increases rapidly with time and then asymptotically approached constant values in all experiments for all side weir dimensions as in non-cohesive sediment. Thus, the scour depth reached equilibrium conditions. Time to equilibrium depends on the approach flow intensity and the dimensions of side weirs. For different heights of the weir crest, dimensionless scour depths increased with increasing upstream Froude number. Equilibrium scour depths which formed 7 cm side-weir crest height were obtained higher than that of the 12 cm side-weir crest height. This means when side-weir crest height increased equilibrium scour depths decreased. Although the upstream side of the scour hole is almost vertical, the downstream side of the hole is inclined.Keywords: Clay-sand mixed sediments, scour, side weir.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 213510066 Experimental Investigation of the Transient Cooling Characteristics of an Industrial Glass Tempering Unit
Authors: Hilmi Yazici, Mehmet Akcay, Mustafa Golcu, Mehmet F. Koseoglu, Yakup Sekmen
Abstract:
Energy consumption rate during the cooling process of industrial glass tempering process is considerably high. In this experimental study the effect of dimensionless jet to jet distance (S/D) and jet to plate distance (H/D) on the cooling time have been investigated. In the experiments 4 mm thick glass samples have been used. Cooling unit consists of 16 mutually placed seamless aluminum nozzles of 8 mm in diameter and 80 mm in length. Nozzles were in staggered arrangement. Experiments were conducted with circular jets for H/D values between 1 and 10, and for S/D values between 2 and 10. During the experiments Reynolds number has been kept constant at 30000. Experimental results showed that the longest cooling time with 87 seconds has been observed in the experiments for S/D=10 and H/D=10 values, while the shortest cooling time with 42.5 seconds has been measured in the experiments for S/D=2 and H/D=4 values.Keywords: Glass tempering, cooling, Reynolds number, nozzle
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