Modeliranje krivulja sušenja iverja od drva smreke, bukve, vrbe i johe

Drying behaviour of spruce (Picea abies (L.) H. Karst.), beech (Fagus sylvatica L.), willow (Salix alba L.), and alder (Alnus glutinosa (L.) Gaertn.) particles was investigated in a convective dryer at constant air velocity of 0.01 m/s and at the drying air temperature of 25, 60, 80, and 150 °C. The results of the experiments have shown that the wood species and drying air temperature infl uence the drying behaviour. The experimental drying data of wood particles obtained were fitted to six empirical models. The effects of wood species and drying air temperature on the drying model parameters were determined. The accuracy of the models was measured using the determination coefficient (R2), root mean square error (RMSE), and reduced chi–square (χ2). The results showed that Lewis model, Henderson and Pabis model, and modifi ed Page model, with the model parameters determined taking into account the effect of wood species and of drying air temperature, were found to satisfactorily describe the drying curves of spruce, beech, willow, and alder particles.U radu su prikazani rezultati istraživanja procesa sušenja iverja od drva smreke (Picea abies (L.) H. Karst.), bukve (Fagus sylvatica L.), vrbe (Salix alba L.) i johe (Alnus glutinosa (L.) Gaertn.) u konvekcijskoj sušionici pri konstantnoj brzini zraka od 0,01 m/s i pri temperaturi zraka 25, 60, 80 i 150 °C. Rezultati pokusa pokazali su da vrsta drva i temperatura zraka utječu na tijek procesa sušenja drvnog iverja. Podaci dobiveni sušenjem iverja analizirani su s pomoću šest empirijskih modela. Određen je učinak vrste drva i temperature zraka na parametre modela sušenja. Točnost modela mjerena je veličinom koefi cijenta determinacije (R2), korijena srednje vrijednosti kvadrata pogreške (RMSE) i reduciranog hi-kvadrata (χ2). Rezultati su pokazali da se krivulje sušenja iverja od drva smreke, bukve, vrbe i johe na zadovoljavajući način mogu opisati primjenom Lewisova modela, Hendersonova i Pabisova modela te modifi ciranoga Pageova modela s parametrima određenima tako da se uzmu u obzir utjecaj vrste drva i temperature zraka pri sušenju iverja

Evaluation of Sustainability of Wheat-Bread Chain Based on the Second Law of Thermodynamics: A Case Study

Wheat flour, bread, and bakery products are an important source of macronutrients, micronutrients, dietary fibers, and antioxidants. Considering that Iran’s bread industry is the second highest bread-consuming industry in the world, this research is focused on the main operations of the bread production chain (wheat cultivation, milling, dough processing, and bread production). Investigating the sustainability and improvement strategies and farm-to-fork approach for the wheat-bread production chain was the aim of this work. Exergy analysis is a powerful tool in designing, optimizing, and evaluating the performance of energy systems to determine energy quality, compare different energy sources, and achieve maximum system performance. In this research, the cumulative degree of perfection, renewability index, and sustainability index of Iranian traditional loaves of bread (Sangak, Lavash, Barbari) and Baguette bread as a semi-industrial bread were estimated. Considering the functional unit of the weight of the produced bread, Baguette and Sangak breads had the highest and lowest sustainability, respectively. Considering the functional unit of energy of the produced bread, Baguette bread has the lowest exergy consumption per 100 cal of the embedded energy of bread. According to the obtained results, the bakery consumes the most exergy in the wheat-bread chain. Natural gas input is the most important indicator of unsustainability in bakeries. Meanwhile, in the entire wheat-bread chain, human labor and natural gas consumption were factors of unsustainability. By using renewable sources, the renewable index increased by 76–89%. Additionally, the use of renewable resources increased the sustainability index of bread production by 7.6 to 1.9 times

Evaluation of Sustainability of Wheat-Bread Chain Based on the Second Law of Thermodynamics: A Case Study

Wheat flour, bread, and bakery products are an important source of macronutrients, micronutrients, dietary fibers, and antioxidants. Considering that Iran’s bread industry is the second highest bread-consuming industry in the world, this research is focused on the main operations of the bread production chain (wheat cultivation, milling, dough processing, and bread production). Investigating the sustainability and improvement strategies and farm-to-fork approach for the wheat-bread production chain was the aim of this work. Exergy analysis is a powerful tool in designing, optimizing, and evaluating the performance of energy systems to determine energy quality, compare different energy sources, and achieve maximum system performance. In this research, the cumulative degree of perfection, renewability index, and sustainability index of Iranian traditional loaves of bread (Sangak, Lavash, Barbari) and Baguette bread as a semi-industrial bread were estimated. Considering the functional unit of the weight of the produced bread, Baguette and Sangak breads had the highest and lowest sustainability, respectively. Considering the functional unit of energy of the produced bread, Baguette bread has the lowest exergy consumption per 100 cal of the embedded energy of bread. According to the obtained results, the bakery consumes the most exergy in the wheat-bread chain. Natural gas input is the most important indicator of unsustainability in bakeries. Meanwhile, in the entire wheat-bread chain, human labor and natural gas consumption were factors of unsustainability. By using renewable sources, the renewable index increased by 76–89%. Additionally, the use of renewable resources increased the sustainability index of bread production by 7.6 to 1.9 times

Mathematical Description of Changes of Dried Apple Characteristics during Their Rehydration

The mathematical description of changes of dried apples characteristics (mass gain, volume increase, dry matter loss, rehydration indices, and colour) during their rehydration was performed. The effect of conditions of both processes on model parameters were also considered. Apple slices (3 and 10 mm) and cubes (10 mm) were dried in natural convection (drying air velocity 0.01 m/s), forced convection (0.5 and 2 m/s), and fluidisation (6 m/s). Drying air temperatures (Td) were equal to 50, 60, and 70 °C. The rehydration process was carried out in distilled water at the temperatures (Tr) of 20, 45, 70, and 95 °C. Mass gain, volume increase, and dry matter loss were modelled using the following empirical models: Peleg, Pilosof–Boquet–Batholomai, Singh and Kulshrestha, Lewis (Newton), Henderson–Pabis, Page, and modified Page. Colour changes were described through applying the first-order model. Artificial neural networks (feedforward multilayer perceptron) were applied to make the rehydration indices and colour variations (ΔE) dependent on characteristic dimension, Td, drying air velocity, and Tr. The Page and the modified Page models can be considered to be the most appropriate in order to characterise the mass gain (RMSE = 0.0143–0.0619) and the volume increase (RMSE = 0.0142–0.1130), whereas the Peleg, Pilosof–Bouquet–Batholomai, and Singh and Kulshrestha models were found to be the most appropriate to characterise dry matter loss (RMSE = 0.0116–0.0454). The ANNs described rehydration indices and ΔE satisfactorily (RMSE = 0.0567–0.0802). Both considered process conditions influenced (although in different degree) the changes of the considered dried apple characteristics during their rehydration

Mathematical Description of Changes of Dried Apple Characteristics during Their Rehydration

The mathematical description of changes of dried apples characteristics (mass gain, volume increase, dry matter loss, rehydration indices, and colour) during their rehydration was performed. The effect of conditions of both processes on model parameters were also considered. Apple slices (3 and 10 mm) and cubes (10 mm) were dried in natural convection (drying air velocity 0.01 m/s), forced convection (0.5 and 2 m/s), and fluidisation (6 m/s). Drying air temperatures (Td) were equal to 50, 60, and 70 °C. The rehydration process was carried out in distilled water at the temperatures (Tr) of 20, 45, 70, and 95 °C. Mass gain, volume increase, and dry matter loss were modelled using the following empirical models: Peleg, Pilosof–Boquet–Batholomai, Singh and Kulshrestha, Lewis (Newton), Henderson–Pabis, Page, and modified Page. Colour changes were described through applying the first-order model. Artificial neural networks (feedforward multilayer perceptron) were applied to make the rehydration indices and colour variations (ΔE) dependent on characteristic dimension, Td, drying air velocity, and Tr. The Page and the modified Page models can be considered to be the most appropriate in order to characterise the mass gain (RMSE = 0.0143–0.0619) and the volume increase (RMSE = 0.0142–0.1130), whereas the Peleg, Pilosof–Bouquet–Batholomai, and Singh and Kulshrestha models were found to be the most appropriate to characterise dry matter loss (RMSE = 0.0116–0.0454). The ANNs described rehydration indices and ΔE satisfactorily (RMSE = 0.0567–0.0802). Both considered process conditions influenced (although in different degree) the changes of the considered dried apple characteristics during their rehydration

Fixed point theorems for nn-periodic mappings in Banach spaces

summary:Using modified Halpern iterations, by elementary method, we extend and improve results obtained by W.A. Kirk (Proc. Amer. Math. Soc. {\bf 29} (1971), 294) and others, which have recently been presented in Chapter 11 of {\it Handbook of Metric Fixed Point Theory\/} (2001)