A modified thermodynamic insight to deliquescence of a void‐containing nanocrystal confirmed by MD simulation

Existence of voids in crystalline structures can affect their physical and chemical properties considerably. When the size of the crystal reaches to nanoscale, experimental determination of its void fraction is difficult. In this work, a molecular dynamics approach is introduced to find equilibrium void fractions of a simple cubic (CsCl) and fcc (KCl) nanocrystals by determination of their deliquescence relative humidity (DRH) for different sizes and void fractions and extrapolation of the results to the bulk limit. To confirm the simulation results, the size dependency of DRH to the nanoparticle size was studied thermodynamically by inclusion of size‐dependent density of water nanodroplet which leads to a simple homographic equation. This method proposes the equilibrium void percents of CsCl and KCl nanoparticles to be 10 and 15%, respectively, which are obtained by extrapolation of the results to the bulk limit. The success of obtained Möbius function was also confirmed by fitting it to experimental data for deliquescence of NaCl nanoparticles which implies the importance of considering density of water nanodroplet as a size dependent quantity. Also, using the mentioned thermodynamic approach, void dependency of deliquescence for the nanoparticles was found to be as a quasi‐linear trend which is compatible with the simulation results. It is noticeable that the approach used this work for determination of equilibrium void fraction is only valid if the utilized force fields are accurate. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4066–4077, 2016     

Optimization of the fermentation conditions and partial characterization for acido-thermophilic <Emphasis Type="Italic">α</Emphasis>-amylase from <Emphasis Type="Italic">Aspergillus niger</Emphasis> NCIM 548

A high performance thermostable α-amylase at low pH values has been synthesized. Sugarcane bagasse was hydrolyzed in a dilute acid solution and utilized as carbon source for the growth of Aspergillus niger strain NCIM 548. Glucose, xylose and arabinose with the ratio of 1.0: 0.9: 0.3 (w/w/w) were detected in the hydrolyzate by HPLC analysis. Optimization of the fermentation conditions for α-amylase production was performed by varying four influential parameters such as Sugarcane bagasse hydrolyzate (SBH), NH₄Cl, pH and incubation time using a central composite design (CCD) under response surface methodology (RSM). The optimum values of SBH, NH₄Cl, pH and incubation time were 20.49, 2.34 g/l, 5.65 and 76.67 h, respectively. The acido-thermophilic enzyme showed maximum stability at 70°C and pH value of 4. The rate constant, K _m and maximum reaction rate, V _max were 18.79 g/l and 15.85 g/l·min, respectively.     

Steady-State Modeling of Multi-Cylinder Dryers in a Corrugating Paper Machine

In this study, a steady-state model was developed to describe the paper drying process and to analyze pocket dryer conditions for a multi-cylinder fluting paper machine in Iran's Mazandaran Wood and Paper Industries. The machine has 35 cylinders grouped in three drying groups and the cylinders are heated from the inside by steam. The model is based on the mass and energy balance relationships written for fiber, air, and water in the drying section. In this research, the heat of sorption and its variations with paper temperature and humidity changes have been taken into account. Temperature and moisture variation of the paper web and cylinder surface temperature in the machine direction were predicted by the proposed model. Also, temperature and humidity of air in the drying pockets and hood exhaust were estimated by the proposed model. Moreover, the model can predict the evaporation rate and specific drying rate with sufficient accuracy in comparison with the TAPPI standard. Finally, the main modeling parameters were compared with the available operating data and the effectiveness of the developed model was verified through validations.     

Hunger alters the expression of acquired hedonic but not sensory qualities of food-paired odors in humans.

To test whether expression of hedonic and sensory odor qualities acquired by association with sweet and bitter tastes depend on hunger state, hungry volunteers experienced odors paired with sucrose, quinine, or water and then were tested under different hunger states manipulated with energy preloads. Acquired liking for sucrose-paired odors was evident following a low-energy or control preload but not a high-energy preload; however, odor sweetness increased in all preload conditions. Acquired dislike and increased bitterness of quinine-paired odors were independent of preloading. These data demonstrate hunger-dependent expression of acquired liking for flavors through flavor-flavor associations in humans and demonstrate independence between acquired hedonic and sensory qualities of odors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heat exchanger networks retrofit with considering pressure drop by coupling genetic algorithm with LP (linear programming) and ILP (integer linear programming) methods

This research is trying to develop a new procedure for retrofit of HENs including pressure drop using genetic algorithm (GA) coupled with linear programming (LP) and integer linear programming (ILP) methods. The GA is used to produce structural modifications whereas continuous variables are handled using a converted NLP formulation for Maximum Energy Recovery (MER). The converted NLP consists of an LP for MER with adding a search loop to find the best minimum approach temperature and split ratios which are easier to solve.To prevent complexity and ensure optimum solution, the pressure drops of streams are calculated from the results of LP and then a modified ILP problem is solved to determine the maximum profit of retrofit of HENs. The motivation of the ILP is decision making for elimination or reuse of current exchangers and pumps and/or introducing new ones to the network. Results show that the proposed method often finds better solutions than those reported in the literature.     

Clinical implications of attentional bias in anxiety disorders: An integrative literature review.

Research on information processing biases has been motivated by the hope that it would lead to new and more efficient psychotherapeutic interventions. The literature is abundant with empirical data of attentional biases toward threat stimuli in anxiety disorders. This article aims to review the existing literature on the topic of attentional bias in anxiety disorders and discuss important implications for clinical practice. We adopted an integrative approach to link research data on attentional bias, information processing, and cognitive accounts (automaticity and controllability) with clinical practice in cognitive-behavioral therapy. It is important to develop and apply therapeutic interventions that can effectively reduce negative attentional biases while treating the main problems associated with anxiety disorders. However, it remains to be seen whether cognitive therapy interventions targeting more voluntary, strategic information processing can have a positive impact on automatic, involuntary processing involved in attentional biases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The characteristics of serrated flow in superalloy IN738LC

Serrated flow was investigated in superalloy IN738LC, a nickel-base γ′ age-hardened alloy. In this material serrated flow appeared between 350 and 450 °C and strain rate of (8.77 × 10⁻⁵ to 8.77 × 10⁻³) s⁻¹. Activation energy for this process was calculated to be 0.69–0.86 eV which is in good agreement with the values reported for similar alloys. Results show that the diffusion rate of substitutional solute atoms at this temperature range is too low to cause this effect. This suggests that the interaction of solute atoms and moving dislocation is responsible for the observed serrated flow in this alloy.