Documents disponibles écrits par cet auteur

Effect of experimental conditions on measuring autoignition temperatures of liquid chemicals / Chan-Cheng Chen in Industrial & engineering chemistry research, Vol. 49 N° 12 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5925–5932 Titre : Effect of experimental conditions on measuring autoignition temperatures of liquid chemicals Type de document : texte imprimé Auteurs : Chan-Cheng Chen, Auteur ; Yen-Cheng Hsieh, Auteur Année de publication : 2010 Article en page(s) : pp. 5925–5932 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Autoignition  temperature Résumé : The principal application of autoignition temperature (AIT) is to define the maximum acceptable surface temperature in a particular area, usually for electrical classification purpose. However, although AITs are indispensable information for safely handling flammable liquids, the reported AITs of flammable liquids in different data compilations are very much diverse. Sometimes, the difference in separate data compilations might up to more than 300 K. This article aims to explore the quantitative effects of flask material, ambient temperature, and ambient humidity on the accuracy for measuring AIT via the method of ASTM E659. To effectively analyze these factors simultaneously, the L9(34) orthogonal arrays are used to allocate experiments, and experiments are then carefully conducted in a temperature- and humidity-controlled laboratory chamber. It is found that ambient humidity does not affect the measured AIT of ethanol, but both flask material and ambient temperature are significant factors in measuring AIT of ethanol. An experiment of measuring AIT of ethanol conducted with a flask material of quartz is found to result in a higher AIT value than the one conducted with a flask material of borosilicate by 20 °C. A quadratic relation between the measured AIT of ethanol (y) and the ambient temperature (x) is found, and it is also found that a quadratic polynomial of y = 3.450 × 10−2 x2 − 1.454x + 3.711 × 102 could properly fit this relation with R2 = 0.9939. According to aforementioned quadratic relation, the ambient temperature at which the lowest AIT of ethanol appears is about 21 °C. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020649 [article] Effect of experimental conditions on measuring autoignition temperatures of liquid chemicals [texte imprimé] / Chan-Cheng Chen, Auteur ; Yen-Cheng Hsieh, Auteur . - 2010 . - pp. 5925–5932. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5925–5932 Mots-clés : Autoignition  temperature Résumé : The principal application of autoignition temperature (AIT) is to define the maximum acceptable surface temperature in a particular area, usually for electrical classification purpose. However, although AITs are indispensable information for safely handling flammable liquids, the reported AITs of flammable liquids in different data compilations are very much diverse. Sometimes, the difference in separate data compilations might up to more than 300 K. This article aims to explore the quantitative effects of flask material, ambient temperature, and ambient humidity on the accuracy for measuring AIT via the method of ASTM E659. To effectively analyze these factors simultaneously, the L9(34) orthogonal arrays are used to allocate experiments, and experiments are then carefully conducted in a temperature- and humidity-controlled laboratory chamber. It is found that ambient humidity does not affect the measured AIT of ethanol, but both flask material and ambient temperature are significant factors in measuring AIT of ethanol. An experiment of measuring AIT of ethanol conducted with a flask material of quartz is found to result in a higher AIT value than the one conducted with a flask material of borosilicate by 20 °C. A quadratic relation between the measured AIT of ethanol (y) and the ambient temperature (x) is found, and it is also found that a quadratic polynomial of y = 3.450 × 10−2 x2 − 1.454x + 3.711 × 102 could properly fit this relation with R2 = 0.9939. According to aforementioned quadratic relation, the ambient temperature at which the lowest AIT of ethanol appears is about 21 °C. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9020649

Prediction of flash point of organosilicon compounds using quantitative structure property relationship approach / Chan-Cheng Chen in Industrial & engineering chemistry research, Vol. 49 N° 24 (Décembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12702–12708 Titre : Prediction of flash point of organosilicon compounds using quantitative structure property relationship approach Type de document : texte imprimé Auteurs : Chan-Cheng Chen, Auteur ; Horng-Jang Liaw, Auteur ; Yi-Jen Tsai, Auteur Année de publication : 2011 Article en page(s) : pp. 12702–12708 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Organosilicon  compounds Résumé : Flash point (FP) is the primary property to classify flammable liquids for the purpose of assessing their fire and explosion hazards. Because of the advancement of technology in discovering or synthesizing new compounds, there is often a significant gap between the demand for such data and their availability. In this regard, reliable methods to estimate the FP of a compound are indispensible. In this work, a quantitative structure property relationship study is presented for predicting the FP of organosilicon compounds. To build up and validate the proposed models, a data set of 230 organosilicon compounds are collected and divided into a training set of 184 compounds and a testing set of 46 compounds. The stepwise regression method is used to select the required molecular descriptors for predicting the FP of organosilicon compounds from 1538 molecular descriptors. Depending on the p-value for accepting a descriptor to enter the model, models with different number of descriptors are obtained. A 13-descriptor model and a 6-descriptor model are obtained with the p-value of 5 × 10−4 and 1 × 10−5, respectively. It is found that the 6-descriptor model could fit the training data with R2 = 0.8981 and predict the test data with Q2 = 0.8533 and the 13-descriptor model could fit the training data with R2 = 0.9293 and predict the test data with Q2 = 0.9245. The average predictive errors are less than 5% for both proposed models and they are useful for many practical applications, because the proposed models used only calculated descriptors from the molecular structure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101381b [article] Prediction of flash point of organosilicon compounds using quantitative structure property relationship approach [texte imprimé] / Chan-Cheng Chen, Auteur ; Horng-Jang Liaw, Auteur ; Yi-Jen Tsai, Auteur . - 2011 . - pp. 12702–12708. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12702–12708 Mots-clés : Organosilicon  compounds Résumé : Flash point (FP) is the primary property to classify flammable liquids for the purpose of assessing their fire and explosion hazards. Because of the advancement of technology in discovering or synthesizing new compounds, there is often a significant gap between the demand for such data and their availability. In this regard, reliable methods to estimate the FP of a compound are indispensible. In this work, a quantitative structure property relationship study is presented for predicting the FP of organosilicon compounds. To build up and validate the proposed models, a data set of 230 organosilicon compounds are collected and divided into a training set of 184 compounds and a testing set of 46 compounds. The stepwise regression method is used to select the required molecular descriptors for predicting the FP of organosilicon compounds from 1538 molecular descriptors. Depending on the p-value for accepting a descriptor to enter the model, models with different number of descriptors are obtained. A 13-descriptor model and a 6-descriptor model are obtained with the p-value of 5 × 10−4 and 1 × 10−5, respectively. It is found that the 6-descriptor model could fit the training data with R2 = 0.8981 and predict the test data with Q2 = 0.8533 and the 13-descriptor model could fit the training data with R2 = 0.9293 and predict the test data with Q2 = 0.9245. The average predictive errors are less than 5% for both proposed models and they are useful for many practical applications, because the proposed models used only calculated descriptors from the molecular structure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101381b

Prediction of flash points of organosilicon compounds by structure group contribution approach / Gow-Bin Wang in Industrial & engineering chemistry research, Vol. 50 N° 22 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 22 (Novembre 2011) . - pp. 12790–12796 Titre : Prediction of flash points of organosilicon compounds by structure group contribution approach Type de document : texte imprimé Auteurs : Gow-Bin Wang, Auteur ; Chan-Cheng Chen, Auteur ; Horng-Jang Liaw, Auteur Année de publication : 2012 Article en page(s) : pp. 12790–12796 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Organosilicon  compounds Résumé : Flash point (FP) is the primary property to evaluate fire hazards of a flammable liquid. In most countries regulations for safe handing, transporting, and storage of liquid chemicals mainly depend on the FPs of liquid chemicals. Due to the advancement of technology in discovery or synthesis of new compounds, FP data are desirable for related industries, but there is often a significant gap between the demand for such data and their availability. Thus, a reliable method to predict the FPs of flammable compounds seems very important in this regard. In the present work a predictive model of FP for organosilicon compounds is proposed via the structure group contribution (SGC) approach. This model is built up by using a training set of 184 organosilicon compounds with the fitting ability (R2) of 0.9330, the average error of 8.91 K, and the average error in percentage of 2.84%. The predictive capability of the proposed model has been demonstrated on a testing set of 46 organosilicon compounds with the predictive capability (Q2) of 0.8868, the average error of 11.15 K, and the average error in percentage of 3.66%. Because the known error for measuring FP by experiment is reported to be about 6–10 K, the proposed method offers a reasonable estimate of the FP for organosilicon compounds. Moreover, the proposed SGC model requires only the molecular structure of a compound to estimate its FP, so it also offers an effective way to approximate the FP of a novel chemical for which its quantity is still not readily available for measuring its FP by experiments. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201132v [article] Prediction of flash points of organosilicon compounds by structure group contribution approach [texte imprimé] / Gow-Bin Wang, Auteur ; Chan-Cheng Chen, Auteur ; Horng-Jang Liaw, Auteur . - 2012 . - pp. 12790–12796. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 22 (Novembre 2011) . - pp. 12790–12796 Mots-clés : Organosilicon  compounds Résumé : Flash point (FP) is the primary property to evaluate fire hazards of a flammable liquid. In most countries regulations for safe handing, transporting, and storage of liquid chemicals mainly depend on the FPs of liquid chemicals. Due to the advancement of technology in discovery or synthesis of new compounds, FP data are desirable for related industries, but there is often a significant gap between the demand for such data and their availability. Thus, a reliable method to predict the FPs of flammable compounds seems very important in this regard. In the present work a predictive model of FP for organosilicon compounds is proposed via the structure group contribution (SGC) approach. This model is built up by using a training set of 184 organosilicon compounds with the fitting ability (R2) of 0.9330, the average error of 8.91 K, and the average error in percentage of 2.84%. The predictive capability of the proposed model has been demonstrated on a testing set of 46 organosilicon compounds with the predictive capability (Q2) of 0.8868, the average error of 11.15 K, and the average error in percentage of 3.66%. Because the known error for measuring FP by experiment is reported to be about 6–10 K, the proposed method offers a reasonable estimate of the FP for organosilicon compounds. Moreover, the proposed SGC model requires only the molecular structure of a compound to estimate its FP, so it also offers an effective way to approximate the FP of a novel chemical for which its quantity is still not readily available for measuring its FP by experiments. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201132v

Set-point weighted PID controller tuning for time-delayed unstable processes / Chan-Cheng Chen in Industrial & engineering chemistry research, Vol. 47 N°18 (Septembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°18 (Septembre 2008) . - p. 6983–6990 Titre : Set-point weighted PID controller tuning for time-delayed unstable processes Type de document : texte imprimé Auteurs : Chan-Cheng Chen, Auteur ; Hsia-Ping Huang, Auteur ; Horng-Jang Liaw, Auteur Année de publication : 2008 Article en page(s) : p. 6983–6990 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : PID  controller  Error  feedback  Nonerror  feedback Résumé : The set-point weighted proportional, integral, and derivative (PID) controller has been shown to be equivalent to an error feedback PID controller with a PD controller in the inner loop; and, many nonerror feedback designs have been unified under the frame of tuning the set-point weighted PID controller. A simple method is then proposed to reform an existing PID control system into a set-point weighted PID control system for unstable processes. To reform an existing error feedback PID control system into the set-point weighted PID control system, the proposed method needs neither the information of the process nor the information of the design methods of the original error feedback PID control system. The only information needed to reform the existing PID control system is the values of the tuning parameters of the original error PID control system. Theoretical analysis shows that if the original error feedback PID control system is stable, the stability of the proposed set-point weighted PID control system is guaranteed automatically. Simulation results show that the performance of the proposed set-point weighted PID control system can be effectively enhanced in comparison with that of the original error feedback PID control system; further, this performance of the proposed set-point weighted PID control system is comparable to that of many other nonerror feedback systems reported in the literature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800001m [article] Set-point weighted PID controller tuning for time-delayed unstable processes [texte imprimé] / Chan-Cheng Chen, Auteur ; Hsia-Ping Huang, Auteur ; Horng-Jang Liaw, Auteur . - 2008 . - p. 6983–6990. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°18 (Septembre 2008) . - p. 6983–6990 Mots-clés : PID  controller  Error  feedback  Nonerror  feedback Résumé : The set-point weighted proportional, integral, and derivative (PID) controller has been shown to be equivalent to an error feedback PID controller with a PD controller in the inner loop; and, many nonerror feedback designs have been unified under the frame of tuning the set-point weighted PID controller. A simple method is then proposed to reform an existing PID control system into a set-point weighted PID control system for unstable processes. To reform an existing error feedback PID control system into the set-point weighted PID control system, the proposed method needs neither the information of the process nor the information of the design methods of the original error feedback PID control system. The only information needed to reform the existing PID control system is the values of the tuning parameters of the original error PID control system. Theoretical analysis shows that if the original error feedback PID control system is stable, the stability of the proposed set-point weighted PID control system is guaranteed automatically. Simulation results show that the performance of the proposed set-point weighted PID control system can be effectively enhanced in comparison with that of the original error feedback PID control system; further, this performance of the proposed set-point weighted PID control system is comparable to that of many other nonerror feedback systems reported in the literature. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800001m

A study on estimating flammability limits in oxygen / Chan-Cheng Chen in Industrial & engineering chemistry research, Vol. 50 N° 17 (Septembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 10283-10291 Titre : A study on estimating flammability limits in oxygen Type de document : texte imprimé Auteurs : Chan-Cheng Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 10283-10291 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flammability  limit Résumé : In many process units, for example, chemical reactors, flammable gases are operated with pure oxygen, and the data of flammability limits in oxygen are crucial to persons who operate such units. Although the data of flammability limits in oxygen are desirable, there is a significant gap between the demand for such data and their availability. In this regard, an effective method for estimating flammability limits in oxygen is indispensible. In this article, formulations based on a thermodynamic approach are proposed to estimate both the upper flammability limit (UFL) and lower flammability limit (LFL) of pure flammable gases in oxygen at atmospheric pressure and room temperature. The proposed formulations are applicable for flammable gases under constant-pressure combustion. These formulations were then examined by an experimental data set of 21 flammable gases. For these investigated gases, average predictive errors are found to be of 4.94% and 6.67% for predicting LFL and UFL in oxygen, respectively. It is also elucidated that for a flammable gas, which tends to decompose or gives rise to a cool flame, the proposed method may result in larger predictive errors because under such conditions the combustion process should be better explained by the chain theory instead of the thermal theory; it is also shown that if the adiabatic flame temperature is higher than 1850 K, the proposed method also may result in larger predictive errors because of the dissociation of burnt products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483673 [article] A study on estimating flammability limits in oxygen [texte imprimé] / Chan-Cheng Chen, Auteur . - 2011 . - pp. 10283-10291. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 17 (Septembre 2011) . - pp. 10283-10291 Mots-clés : Flammability  limit Résumé : In many process units, for example, chemical reactors, flammable gases are operated with pure oxygen, and the data of flammability limits in oxygen are crucial to persons who operate such units. Although the data of flammability limits in oxygen are desirable, there is a significant gap between the demand for such data and their availability. In this regard, an effective method for estimating flammability limits in oxygen is indispensible. In this article, formulations based on a thermodynamic approach are proposed to estimate both the upper flammability limit (UFL) and lower flammability limit (LFL) of pure flammable gases in oxygen at atmospheric pressure and room temperature. The proposed formulations are applicable for flammable gases under constant-pressure combustion. These formulations were then examined by an experimental data set of 21 flammable gases. For these investigated gases, average predictive errors are found to be of 4.94% and 6.67% for predicting LFL and UFL in oxygen, respectively. It is also elucidated that for a flammable gas, which tends to decompose or gives rise to a cool flame, the proposed method may result in larger predictive errors because under such conditions the combustion process should be better explained by the chain theory instead of the thermal theory; it is also shown that if the adiabatic flame temperature is higher than 1850 K, the proposed method also may result in larger predictive errors because of the dissociation of burnt products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24483673