SUMMARYAn exact thermodynamical analysis of systems is only possible under several assumptions; each of them brings an uncertainty in the solution. Without these assumptions, a thermodynamical analysis of a real application requires thousands of nonlinear equations, whose solution is either almost impossible or takes too much computational time and effort. To overcome this obstacle, the artificial neural network (ANN) and fuzzy logic are magic tools, in particular to analyse the systems for arbitrary input and output patterns. This paper deals with the ANN and fuzzy logic analysis of various thermodynamic systems. The first is an efficiency and emission modelling of a stationary natural gas engine using an ANN model, which is able to obtain the effect of various operational parameters such as charge-pressure and temperature, air fuel equivalence ratio, combustion-start and duration and combustion form on the engine efficiency and NO x emission. The second is a cogeneration power plant with three gas turbines, one steam turbine and a district heating system. The effects of ambient-pressure and temperature, relative humidity, wind-velocity and direction on the plant power are investigated using the ANN model, which is based on the measured data from the plant. The last example is a dryer machine. The dryer machine is modelled first as a thermodynamical system. Then a fuzzy logic model is developed to predict the drying time and the power demand depending on condensation pressure and -temperature and evaporation pressure. All models studied here give very accurate and fast estimations which are comparable with the experimental results.

In the present study, a three-dimensional numerical squid model was generated from a computed tomography images of a longfin inshore squid to investigate fluid flow characteristics around the squid. The threedimensional squid model obtained from a 3D-printer was utilized in digital particle image velocimetry (DPIV) measurements to acquire velocity contours in the region of interest. Once the three-dimensional numerical squid model was validated with DPIV results, drag force and coefficient, required jet velocity to reach desired swimming velocity for the squid and propulsion efficiencies were calculated for different nozzle diameters. Besides, velocity and pressure contour plots showed the variation of velocity over the squid body and flow separation zone near the head of the squid model, respectively. The study revealed that viscous drag was nearly two times larger than the pressure drag for the squid's Reynolds numbers of 442500, 949900 and 1510400. It was also found that the propulsion efficiency increases by 20% when the nozzle diameter of a squid was enlarged from 1 cm to 2 cm.

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Milk and whey powders are commonly used ingredients in powdered infant formula (PIF) and follow‐up formula (FUF). In this study, Cronobacter sakazakii and Cronobacter dublinensis both of dairy origin and a reference strain, Cronobacter muytjensii, ATCC 51329 were investigated for thermal inactivation (D and z values). Heat resistance of the pathogen was studied between 52 and 60 °C in trypic soy broth. Among the strains, C. muytjensii ATCC 51329 was the most heat‐resistant strain at lower temperatures (52 and 54 °C). The D‐values at 52 and 54 °C of C. muytjensii ATCC 51329 were 33.30 (±1.17) and 6.79 (±1.05) min, respectively. At higher temperatures, e.g., 56, 58, and 60 °C, C. sakazakii strains 131 and 807 exhibited the highest D values. The D‐values at 56 and 58 °C were 4.73 (±0.40) min for C. sakazakii 131 and 2.30 (±0.26) min for C. sakazakii 807. The D‐values at 60 °C for C. sakazakii 131 and 807 were 1.17 (±0.03) and 1.14 (±0.02) min, respectively. The z‐value of the reference strain (C. muytjensii ATCC 51329) was lower than the other strains. The findings of this study will be very helpful in understanding the heat resistance of C. sakazakii and guarding against this pathogen in PIF and FUF. Practical applications The results presented will play a significant role in eliminating Cronobacter from powdered infant formula and follow‐up formula and ensuring safety against this pathogen.