A new physical pretreatment of plum for drying

In this paper a new physical pretreatment of plums, consists of piercing them by a thin needle, is proposed to increase the rate of drying. The effect of physical pretreatment on drying time was compared with chemical pretreatment that consists of dipping of plums in hot NaOH solution (1%). Drying experiments were carried out in a convective laboratory dryer at 85 °C and 0.81 m/s air velocity. It was observed that pierced plums were dried faster than chemically pretreated plums. After 480 min moisture ratio of pierced sample was 0.07 while for the chemical method it was 0.25. The moisture ratio at any time was compared with seven different mathematical models and the best model was determined according to the best agreement. Accordingly, two-term exponential model for moisture ratio is found to be superior to the other proposed models. The effective diffusivity was found to be 5.471 × 10^?9 m²/s for chemically pretreated and 1.016 × 10^?8 m²/s for physically pretreated plums.     

Effect of post-induction substrate oscillation on recombinant alkaline phosphatase production expressed in Escherichia coli

Microorganisms are exposed to fast changes in microenvironment in large scale bioreactors. Because of their fast response to the changes, overall performance of biological system in small scale differs from large scale. Hence the variations in the environment that microorganisms are living in are mimicked in small scale. For this purpose one way is to feed substrate into the bioreactor in an oscillatory profile. In this work two different types of triangular oscillatory feeding profiles were applied as the post induction feeding strategy in intracellular recombinant alkaline phosphatase production expressed in Escherichia coli to find out if this biological system behaves in inhomogeneous environment differently. On line and offline measurements provide evaluation of product quality and quantity. Then the results of the experiments were compared with those of the control run at which constant feeding rate was executed. The results showed that oscillatory feeding at which cells were not starved led to higher yield of protein per substrate (0.027 C-mol/C-mol) and higher activity per protein (0.79 U/mg) when compared to a constant feeding rate (0.011 C-mol/C-mol and 0.11 U/mg).     

A hierarchical layer of atomic behavior for malicious behaviors prediction

Journal of Computer Virology and Hacking Techniques - Early prediction of malicious activity can help prevent irreparable damage caused by rogue actions. A malware analysis tool can anticipate...     

Characterization of barley straw biochar produced in various temperatures and its effect on lead and cadmium removal from aqueous solutions

Conversion of agricultural wastes into a carbon rich material (i.e. biochar) using pyrolysis process could be an appropriate approach for their management. This study was carried out to convert barley straw to biochar in different temperatures (300, 400 and 500°C) and to investigate the potential of the produced biochar as a sorbent of heavy metals (Pb and Cd). Considering the pretest results of Pb and Cd sorption, the biochar produced at 500°C (BS500) was selected to find effect of pH, the sorbent dose, the initial concentration of Pb and Cd and the contact time on metal removal efficiency. The results showed that the optimum conditions of adsorption were pH = 6, the sorbent dose 1 g/L and the contact time of 45 min. The adsorption kinetics and isotherms had the best fit to the pseudo‐second order and Langmuir models, respectively.     

Microcellular foaming of low‐density polyethylene using nano‐CaCo3 as a nucleating agent

In this study, microcellular foaming of low‐density polyethylene (LDPE) using nano‐calcium carbonate (nano‐CaCO₃) were carried out. Nanocomposite samples were prepared in different content in range of 0.5–7 phr nano‐CaCO₃ using a twin screw extruder. X‐ray diffraction and scanning electron microscopy (SEM) were used to characterize of LDPE/nano‐CaCO3 nanocomposites. The foaming was carried out by a batch process in compression molding with azodicarbonamide (ADCA) as a chemical blowing agent. The cell structure of the foams was examined with SEM, density and gel content of different samples were measured to compare difference between nanocomposite microcellular foam and microcellular foam without nanomaterials. The results showed that the samples containing 5 phr nano‐CaCO₃ showed microcellular foam with the lowest mean cell diameter 27 μm and largest cell density 8 × 10⁸ cells/cm³ in compared other samples. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Mathematical Modeling of the Fluidized Bed Drying of Cubic Materials

The unsteady‐state simultaneous heat and mass transfer between gas and potato cubes during the drying process in a batch fluidized bed was described by a mathematical model. Mass transfer was considered to occur in three dimensions whereas heat transfer between the gas and dried material was assumed to be lumped. It was found that the model could describe the drying process with acceptable accuracy. The moisture profile inside the material at any cross‐section and at any time can be predicted by the model.