Search results for: total pressure ratio
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4880

Search results for: total pressure ratio

3980 Investigation of Heat Loss in Ethanol-Water Distillation Column with Direct Vapour Recompression Heat Pump

Authors: Christopher C. Enweremadu, Hilary L. Rutto

Abstract:

Vapour recompression system has been used to enhance reduction in energy consumption and improvement in energy effectiveness of distillation columns. However, the effects of certain parameters have not been taken into consideration. One of such parameters is the column heat loss which has either been assumed to be a certain percent of reboiler heat transfer or negligible. The purpose of this study was to evaluate the heat loss from an ethanol-water vapour recompression distillation column with pressure increase across the compressor (VRCAS) and compare the results obtained and its effect on some parameters in similar system (VRCCS) where the column heat loss has been assumed or neglected. Results show that the heat loss evaluated was higher when compared with that obtained for the column VRCCS. The results also showed that increase in heat loss could have significant effect on the total energy consumption, reboiler heat transfer, the number of trays and energy effectiveness of the column.

Keywords: Compressor, distillation column, heat loss, vapourrecompression.

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3979 Wavelet-Based ECG Signal Analysis and Classification

Authors: Madina Hamiane, May Hashim Ali

Abstract:

This paper presents the processing and analysis of ECG signals. The study is based on wavelet transform and uses exclusively the MATLAB environment. This study includes removing Baseline wander and further de-noising through wavelet transform and metrics such as signal-to noise ratio (SNR), Peak signal-to-noise ratio (PSNR) and the mean squared error (MSE) are used to assess the efficiency of the de-noising techniques. Feature extraction is subsequently performed whereby signal features such as heart rate, rise and fall levels are extracted and the QRS complex was detected which helped in classifying the ECG signal. The classification is the last step in the analysis of the ECG signals and it is shown that these are successfully classified as Normal rhythm or Abnormal rhythm.  The final result proved the adequacy of using wavelet transform for the analysis of ECG signals.

Keywords: ECG Signal, QRS detection, thresholding, wavelet decomposition, feature extraction.

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3978 Seismic Behavior of a Jumbo Container Crane in the Low Seismicity Zone Using Time-History Analyses

Authors: Huy Q. Tran, Bac V. Nguyen, Choonghyun Kang, Jungwon Huh

Abstract:

Jumbo container crane is an important part of port structures that needs to be designed properly, even when the port locates in low seismicity zone such as in Korea. In this paper, 30 artificial ground motions derived from the elastic response spectra of Korean Building Code (2005) are used for time history analysis. It is found that the uplift might not occur in this analysis when the crane locates in the low seismic zone. Therefore, a selection of a pinned or a gap element for base supporting has not much effect on the determination of the total base shear. The relationships between the total base shear and peak ground acceleration (PGA) and the relationships between the portal drift and the PGA are proposed in this study.

Keywords: Jumbo container crane, portal drift, time history analysis, total base shear.

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3977 High Performance in Parallel Data Integration: An Empirical Evaluation of the Ratio Between Processing Time and Number of Physical Nodes

Authors: Caspar von Seckendorff, Eldar Sultanow

Abstract:

Many studies have shown that parallelization decreases efficiency [1], [2]. There are many reasons for these decrements. This paper investigates those which appear in the context of parallel data integration. Integration processes generally cannot be allocated to packages of identical size (i. e. tasks of identical complexity). The reason for this is unknown heterogeneous input data which result in variable task lengths. Process delay is defined by the slowest processing node. It leads to a detrimental effect on the total processing time. With a real world example, this study will show that while process delay does initially increase with the introduction of more nodes it ultimately decreases again after a certain point. The example will make use of the cloud computing platform Hadoop and be run inside Amazon-s EC2 compute cloud. A stochastic model will be set up which can explain this effect.

Keywords: Process delay, speedup, efficiency, parallel computing, data integration, E-Commerce, Amazon Elastic Compute Cloud (EC2), Hadoop, Nutch.

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3976 Utilizing Taguchi Experimental Design for Optimizing Effective Parameters in Tire Vulcanization

Authors: Ipak Torkpour

Abstract:

In order to convert natural rubber or related polymers to material with varying physical properties such as elastic modulus or durability, a chemical process named sulfur vulcanization is needed. This can be either done by heating sulfur or sulfur-containing compounds. The main goal of this process is to produce untreated natural rubber latex that can be the main source of manufacturing for several rubber producers. Temperature, pressure, and time are considered as three crucial factors in the tire vulcanization process. The present study is an attempt to optimize these crucial parameters, with the aim of achieving maximum tire modulus using Taguchi experimental design. The results revealed that the optimal parameter values are as follows: a temperature of 170 °C, a pressure of 110 bar, and a time duration of 230 seconds. Under these optimized conditions, the obtained tire modulus reached 8.8 kgf.

Keywords: Rubber vulcanization, experimental design, Taguchi, polymers.

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3975 Aqueous Extract of Flacourtia indica Prevents Carbon Tetrachloride Induced Hepatotoxicity in Rat

Authors: Gnanaprakash K, Madhusudhana Chetty C, Ramkanth S, Alagusundaram M, Tiruvengadarajan VS, Angala Parameswari S, Mohamed Saleem TS

Abstract:

Carbon tetrachloride (CCl4) is a well-known hepatotoxin and exposure to this chemical is known to induce oxidative stress and causes liver injury by the formation of free radicals. Flacourtia indica commonly known as 'Baichi' has been reported as an effective remedy for the treatment of a variety of diseases. The objective of this study was to investigate the hepatoprotective activity of aqueous extract of leaves of Flacourtia indica against CCl4 induced hepatotoxicity. Animals were pretreated with the aqueous extract of Flacourtia indica (250 & 500 mg/kg body weight) for one week and then challenged with CCl4 (1.5 ml/kg bw) in olive oil (1:1, v/v) on 7th day. Serum marker enzymes (ALP, AST, ALT, Total Protein & Total Bilirubin) and TBARS level (Marker for oxidative stress) were estimated in all the study groups. Alteration in the levels of biochemical markers of hepatic damage like AST, ALT, ALP, Total Protein, Total Bilirubin and lipid peroxides (TBARS) were tested in both CCl4 treated and extract treated groups. CCl4 has enhanced the AST, ALT, ALP and the Lipid peroxides (TBARS) in liver. Treatment of aqueous extract of Flacourtia indica leaves (250 & 500 mg/kg) exhibited a significant protective effect by altering the serum levels of AST, ALT, ALP, Total Protein, Total Bilirubin and liver TBARS. These biochemical observations were supported by histopathological study of liver sections. From this preliminary study it has been concluded that the aqueous extract of the leaves of Flacourtia indica protects liver against oxidative damages and could be used as an effective protector against CCl4 induced hepatic damage. Our findings suggested that Flacourtia indica possessed good hepatoprotective activity

Keywords: Carbon Tetrachloride, Flacourtia indica, Hepatoprotective activity, Oxidative stress

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3974 Linear Instability of Wake-Shear Layers in Two-Phase Shallow Flows

Authors: Inta Volodko, Valentina Koliskina

Abstract:

Linear stability analysis of wake-shear layers in twophase shallow flows is performed in the present paper. Twodimensional shallow water equations are used in the analysis. It is assumed that the fluid contains uniformly distributed solid particles. No dynamic interaction between the carrier fluid and particles is expected in the initial moment. The stability calculations are performed for different values of the particle loading parameter and two other parameters which characterize the velocity ratio and the velocity deficit. The results show that the particle loading parameter has a stabilizing effect on the flow while the increase in the velocity ratio or in the velocity deficit destabilizes the flow.

Keywords: Linear stability, Shallow flows, Wake-shear flows.

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3973 Comparison of Nutritional and Chemical Parameters of Soymilk and Cow milk

Authors: Bahareh Hajirostamloo

Abstract:

Cow milk, is a product of the mammary gland and soymilk is a beverage made from soybeans; it is the liquid that remains after soybeans are soaked. In this research effort, we compared nutritional parameters of this two kind milk such as total fat, fiber, protein, minerals (Ca, Fe and P), fatty acids, carbohydrate, lactose, water, total solids, ash, pH, acidity and calories content in one cup (245 g). Results showed soymilk contains 4.67 grams of fat, 0.52 of fatty acids, 3.18 of fiber, 6.73 of protein, 4.43 of carbohydrate, 0.00 of lactose, 228.51 of water, 10.40 of total solids and 0.66 of ash, also 9.80 milligrams of Ca, 1.42 of Fe, and 120.05 of P, 79 Kcal of calories, pH=6.74 and acidity was 0.24%. Cow milk contains 8.15 grams of fat, 5.07 of fatty acids, 0.00 of fiber, 8.02 of protein, 11.37 of carbohydrate, ´Çá4.27 of lactose, 214.69 of water, 12.90 of total solids, 1.75 of ash, 290.36 milligrams of Ca, 0.12 of Fe, and 226.92 of P, 150 Kcal of calories, pH=6.90 and acidity was 0.21% . Soy milk is one of plant-based complete proteins and cow milk is a rich source of nutrients as well. Cow milk is containing near twice as much fat as and ten times more fatty acids do soymilk. Cow milk contains greater amounts of mineral (except Fe) it contain more than three hundred times the amount of Ca and nearly twice the amount of P as does soymilk but soymilk contains more Fe (ten time more) than does cow milk. Cow milk and soy milk contain nearly identical amounts of protein and water and fiber is a big plus, dairy has none. Although what we choose to drink is really a mater of personal preference and our health objectives but looking at the comparison, soy looks like healthier choices.

Keywords: Soymilk, cow milk, nutritional, comparison.

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3972 Study of Heat Transfer in the Poly Ethylene Fluidized Bed Reactor Numerically and Experimentally

Authors: Mahdi Hamzehei

Abstract:

In this research, heat transfer of a poly Ethylene fluidized bed reactor without reaction were studied experimentally and computationally at different superficial gas velocities. A multifluid Eulerian computational model incorporating the kinetic theory for solid particles was developed and used to simulate the heat conducting gas–solid flows in a fluidized bed configuration. Momentum exchange coefficients were evaluated using the Syamlal– O-Brien drag functions. Temperature distributions of different phases in the reactor were also computed. Good agreement was found between the model predictions and the experimentally obtained data for the bed expansion ratio as well as the qualitative gas–solid flow patterns. The simulation and experimental results showed that the gas temperature decreases as it moves upward in the reactor, while the solid particle temperature increases. Pressure drop and temperature distribution predicted by the simulations were in good agreement with the experimental measurements at superficial gas velocities higher than the minimum fluidization velocity. Also, the predicted time-average local voidage profiles were in reasonable agreement with the experimental results. The study showed that the computational model was capable of predicting the heat transfer and the hydrodynamic behavior of gas-solid fluidized bed flows with reasonable accuracy.

Keywords: Gas-solid flows, fluidized bed, Hydrodynamics, Heat transfer, Turbulence model, CFD

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3971 Performance Evaluation of Single Basin Solar Still

Authors: Prem Singh, Jagdeep Singh

Abstract:

In an attempt to investigate the performance of single basin solar still for climate conditions of Ludhiana a single basin solar still was designed, fabricated and tested. The energy balance equations for various parts of the still are solved by Gauss-Seidel iteration method. Computer model was made and experimentally validated. The validated computer model was used to estimate the annual distillation yield and performance ratio of the still for Ludhiana. The Theoretical and experimental distillation yield were 4318.79 ml and 3850 ml respectively for the typical day. The predicted distillation yield was 12.5% higher than the experimental yield. The annual distillation yield per square metre aperture area and annual performance ratio for single basin solar still is 1095 litres and 0.43 respectively. The payback period for micro-stepped solar still is 2.5 years.

Keywords: Solar distillation, solar still, single basin, still.

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3970 Nongovernmental Organisations’ Sustainable Strategic Planning and Its Impact on Donors’ Loyalty

Authors: Farah Mahmoud Attallah, Sara El-Deeb

Abstract:

The non-profit sector has been heavily rising with the rise of sustainable development in developed and developing countries. Most economies are putting high pressure on this sector, believing that nongovernmental organizations (NGOs) are one of the main rescues during crises worldwide. However, with the rising number of those NGOs comes their incapability of sustaining their performance and fundraising. Additionally, donors who are considered the key partners for those organizations have become knowledgeable about this sector which made them more demanding, putting high pressure on those organizations to believe that there must be a valuable return for the economy in order to donate. This research aims to study the impact of a sustainable strategic planning model on raising loyal donors; the proposed model of this research presents several independent variables determining their impact on donors' intention to become loyal.

Keywords: Non-profit sector, non-governmental organizations, strategic planning, sustainable business model.

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3969 Experimental Challenges and Solutions in Design and Operation of the Test Rig for Water Lubricated Journal Bearing

Authors: Ravindra Mallya, B. Satish Shenoy, B. Raghuvir Pai

Abstract:

The study deals with the challenges in developing a test rig to test the performance of water lubricated journal bearing. The test rig is designed to simulate the working conditions of the bearing in order to understand their performance before they are put in operation. The bearing that is studied is the commercially available water lubricated bearing which has a rubber liner bonded with a rigid metal shell. The lubricant enters the bearing axially through a pressurized inlet tank and exits to an outlet tank which is at sufficiently low pressure. The load on the bearing is applied through the dead weight system which acts both in upward and downward direction so that net load acts on the bearing. The issues in feeding the lubricant into the bearing from the inlet side and preventing the leakage of the lubricant is discussed. The application of the load on the test bearing while maintaining the bearing afloat is also discussed.

Keywords: Axial groove, hydrodynamic pressure, journal bearing, test rig, water lubrication.

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3968 Compressed Suffix Arrays to Self-Indexes Based on Partitioned Elias-Fano

Authors: Guo Wenyu, Qu Youli

Abstract:

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.

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3967 Solid Particle Erosion of Heat Treated TNB-V4 at Ambient and Elevated Temperatures

Authors: Muhammad Naveed, Richard Stechow, Sebastian Bolz, Katharina Hobusch, Sabine Weiß

Abstract:

Solid particle erosion has been identified as a critical wear phenomenon which takes place during operation of aeroengines in dusty environment. The present work discusses the erosion behavior of Ti-44.5Al-6.25Nb-0.8Mo-0.1B alloy (TNB-V4) which finds its application in low pressure gas turbines and can be used for high pressure compressors too. Prior to the erosion tests, the alloy was heat treated to improve the mechanical properties. Afterwards, specimens were eroded at impact angles of 30° and 90° at room and high temperatures (100 °C-400 °C). Volume loss and erosion behavior are studied through gravimetric analysis, whereas erosion mechanisms are characterized through scanning electron microscopy. The results indicate a clear difference in the erosion mechanism for different impact angles. The influence of the test temperature on the erosion behavior of the alloy is also discussed in the present contribution.

Keywords: Solid particle erosion, gamma TiAl, TNB-V4, high temperature erosion.

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3966 Instability Problem of Turbo-Machines with Radial Distortion Problems

Authors: Yasuo Obikane, Sofiane Khelladi

Abstract:

In the upstream we place a piece of ring and rotate it with 83Hz, 166Hz, 333Hz,and 666H to find the effect of the periodic distortion.In the experiment this type of the perturbation will not allow since the mechanical failure of any parts of the equipment in the upstream will destroy the blade system. This type of study will be only possible by CFD. We use two pumps NS32 (ENSAM) and three blades pump (Tamagawa Univ). The benchmark computations were performed without perturbation parts, and confirm the computational results well agreement in head-flow rate. We obtained the pressure fluctuation growth rate that is representing the global instability of the turbo-system. The fluctuating torque components were 0.01Nm(5000rpm), 0.1Nm(10000rmp), 0.04Nm(20000rmp), 0.15Nm( 40000rmp) respectively. Only for 10000rpm(166Hz) the output toque was random, and it implies that it creates unsteady flow by separations on the blades, and will reduce the pressure loss significantly

Keywords: inlet distorsion, perturbation, turbo-machine

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3965 Error Rate Probability for Coded MQAM with MRC Diversity in the Presence of Cochannel Interferers over Nakagami-Fading Channels

Authors: J.S. Ubhi, M.S. Patterh, T.S. Kamal

Abstract:

Exact expressions for bit-error probability (BEP) for coherent square detection of uncoded and coded M-ary quadrature amplitude modulation (MQAM) using an array of antennas with maximal ratio combining (MRC) in a flat fading channel interference limited system in a Nakagami-m fading environment is derived. The analysis assumes an arbitrary number of independent and identically distributed Nakagami interferers. The results for coded MQAM are computed numerically for the case of (24,12) extended Golay code and compared with uncoded MQAM by plotting error probabilities versus average signal-to-interference ratio (SIR) for various values of order of diversity N, number of distinct symbols M, in order to examine the effect of cochannel interferers on the performance of the digital communication system. The diversity gains and net gains are also presented in tabular form in order to examine the performance of digital communication system in the presence of interferers, as the order of diversity increases. The analytical results presented in this paper are expected to provide useful information needed for design and analysis of digital communication systems with space diversity in wireless fading channels.

Keywords: Cochannel interference, maximal ratio combining, Nakagami-m fading, wireless digital communications.

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3964 Phenols and Manganese Removal from Landfill Leachate and Municipal Wastewater Using the Constructed Wetland

Authors: Amin Mojiri, Lou Ziyang

Abstract:

Constructed Wetland (CW) is a reasonable method to treat wastewater. Current study was carried out to co-treat landfill leachate and domestic wastewater using a CW system. Typha domingensis was transplanted to CW, which encloses two substrate layers of adsorbents named ZELIAC and zeolite. Response surface methodology and central composite design were employed to evaluate experimental data. Contact time (h) and leachate-towastewater mixing ratio (%; v/v) were selected as independent factors. Phenols and manganese removal were selected as dependent responses. At optimum contact time (48.7 h) and leachate-towastewater mixing ratio (20.0%), removal efficiencies of phenols and manganese removal efficiencies were 90.5%, and 89.4%, respectively.

Keywords: Constructed wetland, manganese, phenols, Thypha domingensis.

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3963 The Optimization of Decision Rules in Multimodal Decision-Level Fusion Scheme

Authors: Andrey V. Timofeev, Dmitry V. Egorov

Abstract:

This paper introduces an original method of parametric optimization of the structure for multimodal decisionlevel fusion scheme which combines the results of the partial solution of the classification task obtained from assembly of the mono-modal classifiers. As a result, a multimodal fusion classifier which has the minimum value of the total error rate has been obtained.

Keywords: Сlassification accuracy, fusion solution, total error rate.

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3962 Investigation of the Effect of Cavitator Angle and Dimensions for a Supercavitating Vehicle

Authors: Sri Raman A., A.K.Ghosh

Abstract:

At very high speeds, bubbles form in the underwater vehicles because of sharp trailing edges or of places where the local pressure is lower than the vapor pressure. These bubbles are called cavities and the size of the cavities grows as the velocity increases. A properly designed cavitator can induce the formation of a single big cavity all over the vehicle. Such a vehicle travelling in the vaporous cavity is called a supercavitating vehicle and the present research work mainly focuses on the dynamic modeling of such vehicles. Cavitation of the fins is also accounted and the effect of the same on trajectory is well explained. The entire dynamics has been developed using the state space approach and emphasis is given on the effect of size and angle of attack of the cavitator. Control law has been established for the motion of the vehicle using Non-linear Dynamic Inverse (NDI) with cavitator as the control surface.

Keywords: High speed underwater vehicle, Non-Linear Dynamic Inverse (NDI), six-dof modeling, Supercavitation, Torpedo.

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3961 Simulation and Experimentation on the Contact Width of New Metal Gasket for Asbestos Substitution

Authors: Moch. Agus Choiron, Yoshihiro Kurata, Shigeyuki Haruyama, Ken Kaminishi

Abstract:

The contact width is important design parameter for optimizing the design of new metal gasket for asbestos substitution gasket. The contact width is found have relationship with the helium leak quantity. In the increasing of axial load value, the helium leak quantity is decreasing and the contact width is increasing. This study provides validity method using simulation analysis and the result is compared to experimental using pressure sensitive paper. The results denote similar trend data between simulation and experimental result. Final evaluation is determined by helium leak quantity to check leakage performance of gasket design. Considering the phenomena of position change on the convex contact, it can be developed the optimization of gasket design by increasing contact width.

Keywords: contact width, simulation, pressure sensitive paper.

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3960 Water Vapor Plasma Torch: Design, Characteristics and Applications

Authors: A. Tamošiūnas, P. Valatkevičius, V. Grigaitiene, V. Valinčius

Abstract:

The atmospheric pressure plasma torch with a direct current arc discharge stabilized by water vapor vortex was experimentally investigated. Overheated up to 450K water vapor was used as plasma forming gas. Plasma torch design is one of the most important factors leading to a stable operation of the device. The electrical and thermal characteristics of the plasma torch were determined during the experimental investigations. The design and the basic characteristics of the water vapor plasma torch are presented in the paper. Plasma torches with the electric arc stabilized by water vapor vortex provide special performance characteristics in some plasma processing applications such as thermal plasma neutralization and destruction of organic wastes enabling to extract high caloric value synthesis gas as by-product of the process. Syngas could be used as a surrogate fuel partly replacing the dependence on the fossil fuels or used as a feedstock for hydrogen, methanol production.

Keywords: Arc discharge, atmospheric pressure thermal plasma, plasma torch, water vapor.

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3959 Stress Ratio and Notch Effect on Fatigue Crack Initiation and Propagation in 2024 Al-alloy

Authors: N. Benachour, A. Hadjoui, M. Benachour, M. Benguediab

Abstract:

This study reports an empirical investigation of fatigue crack initiation and propagation in 2024 T351 aluminium alloy using constant amplitude loading. In initiation stage, local strain approach at the notch was used and in stable propagation stage NASGRO model was applied. In this investigation, the flat plate of double through crack at hole is used. Based on experimental results (AFGROW Database), effect of stress ratio, R, is highlights on fatigue initiation life (FIL) and fatigue crack growth rate (FCGR). The increasing of dimension of hole characterizing the notch effect decrease the fatigue life.

Keywords: Fatigue crack growth, initiation life, Al-Alloy, stressratio, notch effect

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3958 Convection through Light Weight Timber Constructions with Mineral Wool

Authors: J. Schmidt, O. Kornadt

Abstract:

The major part of light weight timber constructions consists of insulation. Mineral wool is the most commonly used insulation due to its cost efficiency and easy handling. The fiber orientation and porosity of this insulation material enables flowthrough. The air flow resistance is low. If leakage occurs in the insulated bay section, the convective flow may cause energy losses and infiltration of the exterior wall with moisture and particles. In particular the infiltrated moisture may lead to thermal bridges and growth of health endangering mould and mildew. In order to prevent this problem, different numerical calculation models have been developed. All models developed so far have a potential for completion. The implementation of the flow-through properties of mineral wool insulation may help to improve the existing models. Assuming that the real pressure difference between interior and exterior surface is larger than the prescribed pressure difference in the standard test procedure for mineral wool ISO 9053 / EN 29053, measurements were performed using the measurement setup for research on convective moisture transfer “MSRCMT". These measurements show, that structural inhomogeneities of mineral wool effect the permeability only at higher pressure differences, as applied in MSRCMT. Additional microscopic investigations show, that the location of a leak within the construction has a crucial influence on the air flow-through and the infiltration rate. The results clearly indicate that the empirical values for the acoustic resistance of mineral wool should not be used for the calculation of convective transfer mechanisms.

Keywords: convection, convective transfer, infiltration, mineralwool, permeability, resistance, leakage

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3957 Numerical Simulation of Iron Ore Reactor Isobaric and Cooling zone to Investigate Total Carbon Formation in Sponge Iron

Authors: B. Alamsari, S. Torii, A. Trianto, Y. Bindar

Abstract:

Isobaric and cooling zone of iron ore reactor have been simulated. In this paper, heat and mass transfer equation are formulated to perform the temperature and concentration of gas and solid phase respectively. Temperature profile for isobaric zone is simulated on the range temperature of 873-1163K while cooling zone is simulated on the range temperature of 733-1139K. The simulation results have a good agreement with the plant data. Total carbon formation in the isobaric zone is only 30% of total carbon contained in the sponge iron product. The formation of Fe3C in isobaric zone reduces metallization degree up to 0.58% whereas reduction of metallization degree in cooling zone up to 1.139%. The decreasing of sponge iron temperature in the isobaric and cooling zone is around 300 K and 600 K respectively.

Keywords: Mathematical Model, Iron Ore Reactor, Cooling Zone, Isobaric zone.

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3956 Large-Eddy Simulation of Hypersonic Configuration Aerodynamics

Authors: Huang Shengqin, Xiao Hong

Abstract:

LES with mixed subgrid-scale model has been used to simulate aerodynamic performance of hypersonic configuration. The simulation was conducted to replicate conditions and geometry of a model which has been previously tested. LES Model has been successful in predict pressure coefficient with the max error 1.5% besides afterbody. But in the high Mach number condition, it is poor in predict ability and product 12.5% error. The calculation error are mainly conducted by the distribution swirling. The fact of poor ability in the high Mach number and afterbody region indicated that the mixed subgrid-scale model should be improved in large eddied especially in hypersonic separate region. In the condition of attach and sideslip flight, the calculation results have waves. LES are successful in the prediction the pressure wave in hypersonic flow.

Keywords: Hypersonic, LES, mixed Subgrid-scale model, experiment.

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3955 Excitation Experiments of a Cone Loudspeaker and Vibration-Acoustic Analysis Using FEM

Authors: Y. Hu, X. Zhao, T. Yamaguchi, M. Sasajima, Y. Koike

Abstract:

To focus on the vibration mode of a cone loudspeaker, which acts as an electroacoustic transducer, excitation experiments were performed using two types of loudspeaker units: one employing an impulse hammer and the other a sweep signal. The on-axis sound pressure frequency properties of the loudspeaker were evaluated, and the characteristic properties of the loudspeakers were successfully determined in both excitation experiments. Moreover, under conditions identical to the experiment conditions, a coupled analysis of the vibration-acoustics of the cone loudspeaker was performed using an acoustic analysis software program that considers the impact of damping caused by air viscosity. The result of sound pressure frequency properties with the numerical analysis are the most closely match that measured in the excitation experiments over a wide range of frequency bands.

Keywords: Anechoic room, finite element method, impulse hammer, loudspeaker, reverberation room, sweep signal.

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3954 Influence of Insulation System Methods on Dissipation Factor and Voltage Endurance

Authors: Farzad Yavari, Hamid Chegini, Saeed Lotfi

Abstract:

This paper reviews the comparison of Resin Rich (RR) and Vacuum Pressure Impregnation (VPI) insulation system qualities for stator bar of rotating electrical machines. Voltage endurance and tangent delta are two diagnostic tests to determine the quality of insulation systems. The paper describes the trend of dissipation factor while performing voltage endurance test for different stator bar samples made with RR and VPI insulation system methods. Some samples were made with the same strands and insulation thickness but with different main wall material to prove the influence of insulation system methods on stator bar quality. Also, some of the samples were subjected to voltage at the temperature of their insulation class, and their dissipation factor changes were measured and studied.

Keywords: Vacuum pressure impregnation, resin rich, insulation, stator bar, dissipation factor, voltage endurance.

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3953 Experimental Studies on Multiphase Flow in Porous Media and Pore Wettability

Authors: Xingxun Li, Xianfeng Fan

Abstract:

Multiphase flow transport in porous medium is very common and significant in science and engineering applications. For example, in CO2 Storage and Enhanced Oil Recovery processes, CO2 has to be delivered to the pore spaces in reservoirs and aquifers. CO2 storage and enhance oil recovery are actually displacement processes, in which oil or water is displaced by CO2. This displacement is controlled by pore size, chemical and physical properties of pore surfaces and fluids, and also pore wettability. In this study, a technique was developed to measure the pressure profile for driving gas/liquid to displace water in pores. Through this pressure profile, the impact of pore size on the multiphase flow transport and displacement can be analyzed. The other rig developed can be used to measure the static and dynamic pore wettability and investigate the effects of pore size, surface tension, viscosity and chemical structure of liquids on pore wettability.

Keywords: Enhanced oil recovery, Multiphase flow, Pore size, Pore wettability

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3952 An Analysis of Genetic Algorithm Based Test Data Compression Using Modified PRL Coding

Authors: K. S. Neelukumari, K. B. Jayanthi

Abstract:

In this paper genetic based test data compression is targeted for improving the compression ratio and for reducing the computation time. The genetic algorithm is based on extended pattern run-length coding. The test set contains a large number of X value that can be effectively exploited to improve the test data compression. In this coding method, a reference pattern is set and its compatibility is checked. For this process, a genetic algorithm is proposed to reduce the computation time of encoding algorithm. This coding technique encodes the 2n compatible pattern or the inversely compatible pattern into a single test data segment or multiple test data segment. The experimental result shows that the compression ratio and computation time is reduced.

Keywords: Backtracking, test data compression (TDC), x-filling, x-propagating and genetic algorithm.

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3951 Absorption of CO2 in EAF Reducing Slag from Stainless Steel Making Process by Wet Grinding

Authors: B.M.N. Nik Hisyamudin, S. Yokoyama, M. Umemoto

Abstract:

In the current study, we have conducted an experimental investigation on the utilization of electronic arc furnace (EAF) reducing slag for the absorption of CO2 via wet grinding method. It was carried out by various grinding conditions. The slag was ground in the vibrating ball mill in the presence of CO2 and pure water under ambient temperature. The reaction behavior was monitored with constant pressure method, and the changes of experimental systems volume as a function of grinding time were measured. It was found that the CO2 absorption occurred as soon as the grinding started. The CO2 absorption was significantly increased in the case of wet grinding compare to the dry grinding. Generally, the amount of CO2 absorption increased as the amount of water, weight of slag and initial pressure increased. However, it was decreased when the amount of water exceeds 200ml and when smaller balls were used. The absorption of CO2 occurred simultaneously with the start of the grinding and it stopped when the grinding was stopped. According to this research, the CO2 reacted with the CaO inside the slag, forming CaCO3.

Keywords: CO2 absorption, EAF reducing slag, vibration ball mill, wet grinding.

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