Ralf Moros - Academia.edu (original) (raw)
Papers by Ralf Moros
Journal für praktische Chemie, 1999
Quantitative structure–property relationships were proposed by using artificial neural networks a... more Quantitative structure–property relationships were proposed by using artificial neural networks and information received from 13C NMR spectra. The suitability of 1,2,4-triazolo[1,5-a]pyrimidines as stabilizers in photographic silver halide materials was determined from their chemical structures. For the numeric coding of the chemical structures of differently substituted 1,2,4-triazolo[1,5-a]pyrimidines 1–44 only information available from their 13C NMR spectra was used. Even an assignment of the 13C NMR chemical shift values to the carbons was not necessary. The best results were achieved by combination of the 13C NMR chemical shifts of carbons of the basic heterocycle and the relative fog Drel using a feed-forward two-layer neural network. For some compounds with a good stabilizing effect the calculated results strongly differ from experimental values giving indication of a mechanism which is not covered by the 13C NMR chemical shifts.
Fuel, 2001
A new theoretical model has been developed which explains the association between the molecular s... more A new theoretical model has been developed which explains the association between the molecular structure and the knock resistance of individual gasoline compounds convincingly. The constitutions of more than 300 individual gasoline components were correlated with their knock rating (Blending Research Octane Number, BRON) simultaneously. 13C NMR spectra of all compounds were binned in 28 chemical shift regions of different
Chemie Ingenieur Technik, May 1, 2014
ABSTRACT Die ständig wachsenden und wechselnden Anforderungen des Arbeitsmarktes setzen die Berei... more ABSTRACT Die ständig wachsenden und wechselnden Anforderungen des Arbeitsmarktes setzen die Bereitschaft von Fach- und Führungskräften zu einer stetigen und berufsbegleitenden Weiterbildung voraus. Zudem existiert von Seiten der Fachkräfte der Wunsch nach Vereinbarkeit von Beruf und Familie. Vor diesem Hintergrund wurde ein auf der der Grundlage des Blended Learning beruhendes Konzept für naturwissenschaftlich-technische Weiterbildungsangebote erarbeitet. Exemplarisch wurde dieses Konzept für das Gebiet der Technischen Chemie anhand des Weiterbildungskurses „tc-compactBL” umgesetzt und erprobt.The ever-increasing and ever-changing challenges of the job market require professionals to constantly attend extra occupational education programs. Professionals furthermore express their desire for a compatibility of family and work. Therefore, a general concept for extended vocational training in the field of natural science and technology was developed based on blended learning. As an example, the concept was implemented and tested on the basis of the extended vocational training course “tc-compactBL” in Chemical Technology.
Being part of the major project "Vernetztes Studium Chemie" VIPRATECH aims at developin... more Being part of the major project "Vernetztes Studium Chemie" VIPRATECH aims at developing Internet based teaching aids to provide the means for a virtual laboratory course in chemical engineering and unit operations. With VIPRATECH students and other people have the possibility to inform themselves about the theoretical background and the experimental setup before going ahead with the experiment. Additionally, VIPRATECH helps to visualize fundamental processes as well as to clarify theoretical concepts needed for the evaluation of the received experimental data. One major advantage is the possibility to deepen one's understanding of the underlying concepts while surfing the net. VIPRATECH consists of three parts: multimedia text books, interactive simulations and interfaces for observing/controlling real laboratory experiments via the Internet by using a standard web-browser. The poster discusses the structure and the advantages of VIPRATECH.
Chemical Engineering Science
A method providing initial estimates for rate constants of nonlinear chemical kinetics is propose... more A method providing initial estimates for rate constants of nonlinear chemical kinetics is proposed. This method is based on a genetic algorithm. The particular structure of the genetic algorithm adapted to the problem of estimating rate constants is introduced. The rate and certainty of convergence of the estimation procedure is analysed illustrating the proposed strategy by example of its application to a kinetic model of the catalytic oxidative coupling of methane to C2 hydrocarbons. For this example, the maximum likelihood estimate of the rate constants could be found using initial estimates from the genetic algorithm which were further optimized by a Nelder-Mead algorithm. It is demonstrated that the optimization procedure proposed supports the estimation of rate constants for kinetic models without supposition of rate-determining steps.
The influence of the molecular structure of organic compounds on their knocking behavior was dete... more The influence of the molecular structure of organic compounds on their knocking behavior was determined using a non-Ž. binary genetic algorithm GA. The molecular structures of 240 potential gasoline components were described by use of 16 different structural groups. Partial octane numbers were calculated for these structural groups dependent on the substance classes paraffins, naphthenes, olefins, aromatics and oxygenates. The sum of the calculated partial octane numbers supplies Ž. the octane number of the compound. A multiple linear regression MLR , a neural network and a GA were used for the computations of the connections between the structural groups and the knock ratings. Results obtained by GA were significantly better than these obtained by MLR. The correlation coefficients between the calculated and the test engine determined Ž. Ž. blended research octane numbers were for paraffins R s 0.988 R s 0.954 , naphthenes R s 0.975 0.877 , olefins GA MLR Ž. Ž. Ž. R s 0.984 0.959 , aromatics R s 0.945 0.877 and for the oxygenates R s 0.964 0.919. The calculated partial octane numbers allows the quantitative determination of influences of structure modifications on the knocking characteristics of gasoline components.
Trans IChemE, Part D, …, 2007
The idea for this paper resulted from a workshop on the use of remotely operated experiments (web... more The idea for this paper resulted from a workshop on the use of remotely operated experiments (weblabs) in chemical engineering education held in Cambridge, UK, in July 2005 (http://como.cheng.cam.ac.uk/conf.workshop.html). At the workshop people using weblabs met to discuss experiences and different approaches on how to make the most out of remote experiments in undergraduate chemical engineering teaching. We describe the technology involved in making educational experiments available on the internet and how they are motivated and used in teaching at MIT, the University of Cambridge and the University of Leipzig. Experiences are discussed and we give our view of the strengths and weaknesses of weblabs in chemical engineering education.
Journal für praktische Chemie, 1999
Quantitative structure–property relationships were proposed by using artificial neural networks a... more Quantitative structure–property relationships were proposed by using artificial neural networks and information received from 13C NMR spectra. The suitability of 1,2,4-triazolo[1,5-a]pyrimidines as stabilizers in photographic silver halide materials was determined from their chemical structures. For the numeric coding of the chemical structures of differently substituted 1,2,4-triazolo[1,5-a]pyrimidines 1–44 only information available from their 13C NMR spectra was used. Even an assignment of the 13C NMR chemical shift values to the carbons was not necessary. The best results were achieved by combination of the 13C NMR chemical shifts of carbons of the basic heterocycle and the relative fog Drel using a feed-forward two-layer neural network. For some compounds with a good stabilizing effect the calculated results strongly differ from experimental values giving indication of a mechanism which is not covered by the 13C NMR chemical shifts.
Fuel, 2001
A new theoretical model has been developed which explains the association between the molecular s... more A new theoretical model has been developed which explains the association between the molecular structure and the knock resistance of individual gasoline compounds convincingly. The constitutions of more than 300 individual gasoline components were correlated with their knock rating (Blending Research Octane Number, BRON) simultaneously. 13C NMR spectra of all compounds were binned in 28 chemical shift regions of different
Chemie Ingenieur Technik, May 1, 2014
ABSTRACT Die ständig wachsenden und wechselnden Anforderungen des Arbeitsmarktes setzen die Berei... more ABSTRACT Die ständig wachsenden und wechselnden Anforderungen des Arbeitsmarktes setzen die Bereitschaft von Fach- und Führungskräften zu einer stetigen und berufsbegleitenden Weiterbildung voraus. Zudem existiert von Seiten der Fachkräfte der Wunsch nach Vereinbarkeit von Beruf und Familie. Vor diesem Hintergrund wurde ein auf der der Grundlage des Blended Learning beruhendes Konzept für naturwissenschaftlich-technische Weiterbildungsangebote erarbeitet. Exemplarisch wurde dieses Konzept für das Gebiet der Technischen Chemie anhand des Weiterbildungskurses „tc-compactBL” umgesetzt und erprobt.The ever-increasing and ever-changing challenges of the job market require professionals to constantly attend extra occupational education programs. Professionals furthermore express their desire for a compatibility of family and work. Therefore, a general concept for extended vocational training in the field of natural science and technology was developed based on blended learning. As an example, the concept was implemented and tested on the basis of the extended vocational training course “tc-compactBL” in Chemical Technology.
Being part of the major project "Vernetztes Studium Chemie" VIPRATECH aims at developin... more Being part of the major project "Vernetztes Studium Chemie" VIPRATECH aims at developing Internet based teaching aids to provide the means for a virtual laboratory course in chemical engineering and unit operations. With VIPRATECH students and other people have the possibility to inform themselves about the theoretical background and the experimental setup before going ahead with the experiment. Additionally, VIPRATECH helps to visualize fundamental processes as well as to clarify theoretical concepts needed for the evaluation of the received experimental data. One major advantage is the possibility to deepen one's understanding of the underlying concepts while surfing the net. VIPRATECH consists of three parts: multimedia text books, interactive simulations and interfaces for observing/controlling real laboratory experiments via the Internet by using a standard web-browser. The poster discusses the structure and the advantages of VIPRATECH.
Chemical Engineering Science
A method providing initial estimates for rate constants of nonlinear chemical kinetics is propose... more A method providing initial estimates for rate constants of nonlinear chemical kinetics is proposed. This method is based on a genetic algorithm. The particular structure of the genetic algorithm adapted to the problem of estimating rate constants is introduced. The rate and certainty of convergence of the estimation procedure is analysed illustrating the proposed strategy by example of its application to a kinetic model of the catalytic oxidative coupling of methane to C2 hydrocarbons. For this example, the maximum likelihood estimate of the rate constants could be found using initial estimates from the genetic algorithm which were further optimized by a Nelder-Mead algorithm. It is demonstrated that the optimization procedure proposed supports the estimation of rate constants for kinetic models without supposition of rate-determining steps.
The influence of the molecular structure of organic compounds on their knocking behavior was dete... more The influence of the molecular structure of organic compounds on their knocking behavior was determined using a non-Ž. binary genetic algorithm GA. The molecular structures of 240 potential gasoline components were described by use of 16 different structural groups. Partial octane numbers were calculated for these structural groups dependent on the substance classes paraffins, naphthenes, olefins, aromatics and oxygenates. The sum of the calculated partial octane numbers supplies Ž. the octane number of the compound. A multiple linear regression MLR , a neural network and a GA were used for the computations of the connections between the structural groups and the knock ratings. Results obtained by GA were significantly better than these obtained by MLR. The correlation coefficients between the calculated and the test engine determined Ž. Ž. blended research octane numbers were for paraffins R s 0.988 R s 0.954 , naphthenes R s 0.975 0.877 , olefins GA MLR Ž. Ž. Ž. R s 0.984 0.959 , aromatics R s 0.945 0.877 and for the oxygenates R s 0.964 0.919. The calculated partial octane numbers allows the quantitative determination of influences of structure modifications on the knocking characteristics of gasoline components.
Trans IChemE, Part D, …, 2007
The idea for this paper resulted from a workshop on the use of remotely operated experiments (web... more The idea for this paper resulted from a workshop on the use of remotely operated experiments (weblabs) in chemical engineering education held in Cambridge, UK, in July 2005 (http://como.cheng.cam.ac.uk/conf.workshop.html). At the workshop people using weblabs met to discuss experiences and different approaches on how to make the most out of remote experiments in undergraduate chemical engineering teaching. We describe the technology involved in making educational experiments available on the internet and how they are motivated and used in teaching at MIT, the University of Cambridge and the University of Leipzig. Experiences are discussed and we give our view of the strengths and weaknesses of weblabs in chemical engineering education.