47 research outputs found
Determination of the effect of edge banding thickness and aging period on the MOR and MOE of melamine coated particle board using Taguchi method
U ovom istraživanju, razdoblje starenja (20, 30, 40 i 50 dana), debljina kantiranja (0,4; 0,8; 1 i 2 mm) i vrsta ostvarivanja sile (savojna čvrstoća - MOR i vlačna čvrstoća - MOE) odabrani su kao parametri za analizu učinaka na mehanička svojstva melaminom obložen iverice. U tu svrhu, Taguchijevo oblikovanje metodologije pokusa provedeno je za optimizaciju procesnih parametara. Pokusi su provedeni po ortogonalnom polju L16 sa 16 kombinacija ispitnih varijabli za procjenu utjecaja različitih čimbenika. Analiza varijance također je bila uključena za istraživanje koji parametri konstrukcije značajno utječu na mehanička svojstva melaminom obložene iverice. Statistička je analiza pokazala da vrsta ostvarivanja sile krajnje promjenjivo djeluje na odziv. Simulirani i eksperimentalni rezultati također pokazuju dobro slaganje jednih s drugima.In this study, the aging period (20, 30, 40 and 50 days), the edge banding thickness (0,4; 0,8;1,0 and 2,0 mm) and the type of force used (bending strength-MOR and tensile strength-MOE) were the parameters selected for analysis of the effects on the mechanical properties of melamine coated particle board. To do this, Taguchi\u27s methodology for the design of experiments was used to optimize the process parameters. Trials are conducted using an L16 orthogonal array with 16 combinations of test variables to assess the influence of various factors. Analysis of variance was also employed to investigate which design parameters significantly affect the mechanical properties of melamine coated particle board. The statistical analysis showed that the type of force used was the most significant factor affecting the response. The simulated and experimental results also showed good agreement with each other
ENERGY CONVERSION AND MANAGEMENT
Electricity generation or power recovery through pressure reduction stations (PRS) for general use has not been realized in Izmir. The main objective of the present study was to do a case study for calculating electricity to be recovered in one natural gas pressure reduction stations in Izmir. It is the first forecasting study to obtain energy from natural gas pressure-reducing stations in Izmir. Energy can be obtained from natural gas PRS with turbo-expanders instead of using throttle valves or regulators from the PRS. The exergy performance of PRS with TE is evaluated in this study. Exergetic efficiencies of the system and components are determined to assess their individual performances. Based upon pressure change and volumetric flow rate, it can be obtained by recovering average estimated installed capacity and annual energy 494.24 kW, 4113.03 MW h, respectively. In terms of estimated installed capacity power and annual energy, the highest level is 764.88 kW, approximately 6365.34 MW h, in Aliaga PRS. Also it can be seen that CO2 emission factor average value is 295.45 kg/MW h. (C) 2015 Elsevier Ltd. All rights reserved
Tingimento de fibras sintéticas com corantes dispersos
Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia QuímicaNesta última década vem ocorrendo uma grande evolução de consumo das fibras no mundo; constata-se o crescimento do consumo das sintéticas frente às naturais, que alcançou 36% nos últimos seis anos, contra apenas 4% observado para as fibras naturais, no mesmo período. A fibra de poliéster é uma das fibras sintéticas que apresenta uma estrutura mais compacta e cristalina. Para o seu tingimento são utilizados corantes dispersos. Neste trabalho foi estudado o processo de tingimento de uma mistura de fibras de poliéster com elastano, de títulos 167 Dtex e 100 Dtex, obtendo-se a cinética de montagem do corante nas fibras. Para os ensaios foram utilizados três diferentes corantes: Disperse Red 60 de molécula pequena, o Disperse Orange 30 de molécula média e o Disperse Blue 60 de molécula grande. Avaliaram-se as concentrações dos corantes nas fibras, fixando-se variáveis como: pH, relação de banho, concentração do corante e concentração dos auxiliares de tingimento (igualizante e dispersante), temperatura e tempo de tingimento. Foram realizados vários ensaios, incluindo processos utilizando-se somente os corantes e processos utilizando-se os corantes e os auxiliares de tingimento. Observou-se que tanto para a fibra de PES/PUE de título 167 Dtex como para a microfibra de PES/PUE de título 100 Dtex, os corantes de molécula pequena se difundiram com maior facilidade para o interior da fibra. Os corantes de molécula média e grande encontram maior resistência na difusão para o interior da fibra. A microfibra PES/PUE, por apresentar menor porosidade quando comparada com a fibra de PES/PUE, apresenta uma maior resistência à transferência de massa. No tingimento com corante de molécula grande (Disperse Blue 60), foi realizada uma termofixação do substrato após o tingimento, a 190°C por 50 segundos, devido ao acúmulo de corante na superfície da fibra. Após a termofixação à alta temperatura, ocorre a sublimação do corante depositado na superfície da fibra. Os ensaios experimentais foram realizados no laboratório, nas mesmas condições do processo industrial. Observou-se uma grande concordância entre os perfis de concentração obtidos nos dois processos, permitindo que os resultados obtidos em escala laboratorial sejam utilizados para predizer o comportamento do processo de tingimento em escala industrial
Optimization of tool geometry parameters for turning operations based on the response surface methodology
This investigation focuses on the influence of tool geometry on the surface finish obtained in turning of AISI 1040 steel. In order to find out the effect of tool geometry parameters on the surface roughness during turning, response surface methodology (RSM) was used and a prediction model was developed related to average surface roughness (Ra) using experimental data. The results indicated that the tool nose radius was the dominant factor on the surface roughness. In addition, a good agreement between the predicted and measured surface roughness was observed. Therefore, the developed model can be effectively used to predict the surface roughness on the machining of AISI 1040 steel with in 95% confidence intervals ranges of parameters studied
Energy and exergy analysis of electricity generation from natural gas pressure reducing stations
WOS: 000350711100012Electricity generation or power recovery through pressure reduction stations (PRS) for general use has not been realized in Izmir. The main objective of the present study was to do a case study for calculating electricity to be recovered in one natural gas pressure reduction stations in Izmir. It is the first forecasting study to obtain energy from natural gas pressure-reducing stations in Izmir. Energy can be obtained from natural gas PRS with turbo-expanders instead of using throttle valves or regulators from the PRS. The exergy performance of PRS with TE is evaluated in this study. Exergetic efficiencies of the system and components are determined to assess their individual performances. Based upon pressure change and volumetric flow rate, it can be obtained by recovering average estimated installed capacity and annual energy 494.24 kW, 4113.03 MW h, respectively. In terms of estimated installed capacity power and annual energy, the highest level is 764.88 kW, approximately 6365.34 MW h, in Aliaga PRS. Also it can be seen that CO2 emission factor average value is 295.45 kg/MW h. (C) 2015 Elsevier Ltd. All rights reserved.Izmir Gas Inc.The authors gratefully acknowledge the support provided for this work by Izmir Gas Inc. and personal support by Mr. Burcin Yandimata, the general manager. This study would not have been possible without the cooperation and assistance of the personnel at the Izmir Natural Gas Inc
A new process damping model for chatter vibration
This paper presents a new analytical process damping model (PDM) and calculation of Process Damping Ratios (PDR) for chatter vibration for low cutting speeds in turning operations. In this study a two degree of freedom complex dynamic model of turning with orthogonal cutting system is considered. The complex dynamic system consists of dynamic cutting system force model which is based on the shear angle (u) oscillations and the penetration forces which are caused by the tool flank contact with the wavy surface. Depending on PDR, the dynamic equations of the cutting system are described by a new mathematical model. Variation and quantity of PDR are predicted by reverse running analytical calculation procedure of traditional Stability Lobe Diagrams (SLD). Developed mathematical model is performed theoretically for turning operations in this study and simulation results are verified experimentally by cutting tests
Selection of tool and work piece combination using Multiple Attribute Decision Making Methods for Computer Numerical Control turning operation
Decomposition of Process Damping Ratios and Verification of Process Damping Model for Chatter Vibration
In the previous study, by the same authors, titled ‘‘A new process damping model (PDM) for chatter vibration (Measurement, 44 (8) (2011) 1342–1348)’’, a new approach has been presented for obtaining process damping ratios (PDRs). This PDM has been constituted on the basis of the shear angle ?u? oscillations of the cutting tool and the alteration of the penetration forces when they penetrate into the wavy surface. Variation and quantity of PDR are predicted by reverse running analytical calculation procedure of traditional Stability Lobe Diagrams (SLDs). In this study, firstly, how the PDM in previous study results with different materials such as AISI-1050 and Al-7075 are examined. Then, two problems are solved: how much of the total PDR of cutting system is caused by the tool penetration and how much is caused by ?u? oscillation? Finally, verification of PDR values and PDM are performed by energy equations
The Validation as Experimental and Numerical of the Values of Thrust Force and Torque in Drilling Process
Drilling is the most common machining process whereby the operation involves making round holes in metallic
and nonmetallic materials. Metal drilling operations are quite complex and usually complicated. Nevertheless,
knowledge about metal drilling process related to using Finite Element Model in literature is quite limited
reported. In this study, a Lagrangian Incremental Finite Element Model selected for the metal drilling process.
The drilling force and torque values were obtained using Finite Element Model for AISI 1040 workpiece
material. A comparison presented between the drilling force and torque values which are obtained by measured
and Finite Element Model, and then a good agreement found between measured and predicted force and torque
values