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Roland Bálint and Attila Magyar

Abstract

The cost optimal scheduling of a household refrigerator is presented in this work. The fundamental approach is the model predictive control methodology applied to the piecewise affine model of the refrigerator.

The optimisation could not be solved using off-the-shelf tools, e.g. Multi-Parametric Toolbox, so a binary treebased optimal scheduling algorithm has been developed for this problem.

Open access

Tamás Mátrai, János Tóth and Márton Tamás Horváth

Abstract

Mobility management centres play a significant role in urban transport, taking into account several factors that have an effect on the flow of vehicles. In the present paper a mobility management centre equipped with necessary information and information technologies for travellers is presented that can provide route plans. A route guidance methodology is described that combines current transportation demands with the results of the traditional four-step model.

Open access

Gyula Dörgő and János Abonyi

Abstract

The search for compounds exhibiting desired physical and chemical properties is an essential, yet complex problem in the chemical, petrochemical, and pharmaceutical industries. During the formulation of this optimization-based design problem two tasks must be taken into consideration: the automated generation of feasible molecular structures and the estimation of macroscopic properties based on the resultant structures. For this structural characteristic-based property prediction task numerous methods are available. However, the inverse problem, the design of a chemical compound exhibiting a set of desired properties from a given set of fragments is not so well studied. Since in general design problems molecular structures exhibiting several and sometimes conflicting properties should be optimized, we proposed a methodology based on the modification of the multi-objective Non-dominated Sorting Genetic Algorithm-II (NSGA-II). The originally huge chemical search space is conveniently described by the Joback estimation method. The efficiency of the algorithm was enhanced by soft and hard structural constraints, which expedite the search for feasible molecules. These constraints are related to the number of available groups (fragments), the octet rule and the validity of the branches in the molecule. These constraints are also used to introduce a special genetic operator that improves the individuals of the populations to ensure the estimation of the properties is based on only reliable structures. The applicability of the proposed method is tested on several benchmark problems.

Open access

Erzsébet Bognár, Gabriella Hellner, Andrea Radnóti, László Somogyi and Zsolt Kemény

Abstract

Glycidyl esters are foodborne contaminants formed during the production of fats and oils, especially during the deodorization of palm oil. The hydrolyzed free form of glycidol has been categorized as probably carcinogenic to humans by the World Health Organization’s International Agency for Research on Cancer. The aim of this research was to study the formation of glycidyl esters during the lab-scale deodorization of the three most widely produced seed oils in the world (sunflower, rapeseed and soybean). The effects of two independent factors – temperature and residence time – were analyzed by a 32 full factorial experimental design and evaluated by response surface methodology. In accordance with findings in the literature, the greatest amount of glycidyl esters was formed in the soybean oil matrix. For all three oils, the effects of both residence time and temperature were significant, while the latter was more so. To reduce the formation of glycidyl esters, milder deodorization is required, which is limited because of the purposes sought by the thermal operation and removal of volatile minor components and contaminants.

Open access

Dheeaa Al Deen Atallah Aljubourya, Puganeshwary Palaniandy, Hamidi Bin Abdul Aziz and Shaik Feroz

Abstract

This study was carried out to compare the performance of different oxidation processes, such as solar photo-Fenton reaction, solar photocatalysis by TiO2, and the combination of the two for the treatment of petroleum wastewater from Sohar Oil Refinery by a central composite design with response surface methodology. The degradation efficiency was evaluated in terms of chemical oxygen demand (COD) and total organic carbon (TOC) reductions. Solar photocatalysis by the TiO2/Fenton method improved the performance of the photocatalyst at neutral pH for petroleum wastewater without the need to adjust the pH during this treatment. Under acidic conditions, the solar photo-Fenton process is more efficient than solar TiO2 photocatalysis while it is less efficient under alkaline conditions. The TiO2 dosage and pH are the two main factors that improved the TOC and COD reductions in the solar photocatalysis using combined TiO2/Fenton and the solar TiO2 photocatalysis processes while the pH and H2O2 concentration are the two key factors that affect the solar photo-Fenton process.

Open access

Muhammad Abbas Ahmad Zaini and Mohd Shafiq Mohd Shaid

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Open access

Viktor Sebestyén, Viola Somogyi, Szandra Szőke and Anett Utasi

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Open access

Zsófia Bedő, Katalin Bélafi-Bakó, Nándor Nemestóthy and László Gubicza

. Chem., 2011 39 (3), 395–399 [14] Koszorz, Z.; Nemestóthy, N.; Ziobrowski, Z.; Bélafi-Bakó, K.; Krupiczka, R.: Influence of pervaporation process parameters on enzymatic catalyst deactivation, Desalination, 2004 162 , 307–313 DOI: 10.1016/S0011-9164(04)00064-5 [15] Güvenc, A.; Kapucu, N.; Kapucu, H.; Aydogan, Ö.; Mehmetoglu, Ü.: Enzymatic esterification of isoamyl alcohol obtained from fusel oil: Optimization by response surface methodology, Enzyme Microb. Tech., 2007 40 , 778–785 DOI: 10.1016/j.enzmictec.2006.06.010 [16] Vekariya, R.L.: A

Open access

Mihály Zakar, Ildikó Kovács, Péter Muhi, Erika Hanczné Lakatos, Gábor Keszthelyi-Szabó and Zsuzsanna László

, for the recovery and reuse of dairy industry effluents, Water Sci. Tech. , 2000 41 (1) 213–221 web: http://wst.iwaponline.com/content/41/1/213 [9] Luo, J.; Ding, L.; Qi, B.; Jaffrin, M.Y.; Wan, Y.: A two-stage ultrafiltration and nanofiltration process for recycling dairy wastewater, Bioresour. Technol. , 2011 102 (16), 7437–7442 DOI 10.1016/j.biortech.2011.05.012 [10] Bégoin, L.; Rabiller-Baudry, M.; Chaufer, B.; Faille, C.; Blanpain-Avet, P.; Bénézech, T.; Doneva, T.: Methodology of analysis of a spiralwound module. Application to PES membrane for

Open access

Fruzsina Gerencsér, Norbert Rieder, Csilla Varga, Jenő Hancsók and András Dallos

, solvent-free methodology for the functionalisation of carbon nanotubes, Chem. Sci ., 2010 1 (5), 603-608 DOI: 10.1039/C0SC00287A [16] Menzel, R.; Lee, A.; Bismarck, A.; Shaffer, M.S.P.: Inverse gas chromatography of as-received and modified carbon nanotubes, Langmuir , 2009 25 (14), 8340–8348 DOI: 10.1021/la9000607s [17] Díaz, E.; Ordóñez, S.; Vega, A.: Characterization of nanocarbons (nanotubes and nanofibers) by inverse gas chromatography, J. Phys. Conf. Ser. , 2017 61 (1), 904-908 DOI: 10.1088/1742-6596/61/1/180 [18] Menzel, R.; Lee, A