Reducing the energy demand of corn‐based fuel ethanol through salt extractive distillation enabled by electrodialysis

The thermal energy demand for producing fuel ethanol from the fermentation broth of a contemporary corn‐to‐fuel ethanol plant in the U.S. is largely satisfied by combustion of fossil fuels, which impacts the possible economical and environmental advantages of bioethanol over fossil fuels. To reduce the thermal energy demand for producing fuel ethanol, a process integrating salt extractive distillation—enabled by a new scheme of electrodialysis and spray drying for salt recovery—in the water‐ethanol separation train of a contemporary corn‐to‐fuel ethanol plant is investigated. Process simulation using Aspen Plus® 2006.5, with the electrolyte nonrandom two liquid Redlich‐Kwong property method to model the vapor liquid equilibrium of the water‐ethanol‐salt system, was carried out. The integrated salt extractive distillation process may provide a thermal energy savings of about 30%, when compared with the contemporary process for separating fuel ethanol from the beer column distillate. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Effects of gelation temperature on Mozzarella-type curd made from buffalo and cows’ milk. 1: Rheology and microstructure

The rheology and microstructure of Mozzarella-type curds made from buffalo and cows’ milk were measured at gelation temperatures of 28, 34 and 39 °C after chymosin addition. The maximum curd strength (G′) was obtained at a gelation temperature of 34 °C in both types of bovine milk. The viscoelasticity (tan δ) of both curds was increased with increasing gelation temperature. The rennet coagulation time was reduced with increase of gelation temperature in both types of milk. Frequency sweep data (0.1–10Hz was recorded 90 min after chymosin addition, and both milk samples showed characteristics of weak viscoelastic gel systems. When both milk samples were subjected to shear stress to break the curd system at constant shear rate, 95 min after chymosin addition, the maximum yield stress was obtained at the gelation temperatures of 34 °C and 28 °C in buffalo and cows’ curd respectively. The cryo-SEM and CLSM techniques were used to observe the microstructure of Mozzarella-type curd. The porosity was measured using image J software. The cryo-SEM and CLSM micrographs showed that minimum porosity was observed at the gelation temperature of 34 °C in both types of milk. Buffalo curd showed minimum porosity at similar gelation temperature when compared to cows’ curd. This may be due to higher protein concentration in buffalo milk.     

Effects of gelation temperature on Mozzarella-type curd made from buffalo and cows' milk: 2. Curd yield, overall quality and casein fractions

The overall quality of Mozzarella-type curds made from buffalo and cows' milks were measured at gelation temperatures of 28, 34 and 39°C, and cutting times of 45, 60, 75 and 90min after chymosin addition. The curd yield and moisture content decreased with increasing gelation temperature, while whey fat losses increased. The effect of higher gelation temperature (39°C) was more pronounced in cows' milk than buffalo milk. This results in more fat losses and lower yields in both milk samples at a gelation temperature of 39°C. The minimum losses of fat and protein in rennet whey occurred at a gelation temperature of 34°C in both milk samples. The curd yield was higher in buffalo milk as compared to cows' milk. This is due to difference in total solids (fat and protein contents) of the two types of bovine milk. The different cutting times had a small effect on the yield and overall quality of curds made from both milk types. Curd moisture and loss tangent have a strong relationship with respect to effects of gelation temperature. Two different curd drainage methods (centrifugation and Buchner funnel filtration) were used to compare the final overall quality of Mozzarella-type curds made from both milk types. The α(s1) and β casein fractions were found to be in different proportions in the two milk types. The total- and casein bound-calcium were higher in buffalo milk than cows' milk. The total protein, casein and fat were also found to be higher in buffalo milk than cows' milk.     

Numerical analysis of intermodal delay in few-mode fibers for mode division multiplexing in optical fiber communication systems

In order to achieve higher spectral efficiency, mode division multiplexing (MDM) in few-mode fibers is a new research area. The idea faces lots of technical issues including intermodal delay and mode coupling which limit the achievable length of the system. This paper is designated to complete the analysis of intermodal delay in step-index few-mode fibers. We analyze numerically all the parameters of fiber, which could impact intermodal delay in few-mode fibers and identify the conditions which can increase the number of multiplex modes without significant increase in maximum intermodal delay.     

Effect of woven fabric structure on the air permeability and moisture management properties

In this study, six different woven samples were produced on air jet loom with two different weave designs (i.e. 3/1 twill and 1/1 plain), three different picking sequences (i.e. single pick insertion (SPI), double pick insertion (DPI) and three pick insertion (3PI)). All the woven samples were singed, desized, bleached and finished together at industrial scale, as a single lot. The effect of these factors on the wetting, wicking and air permeability (AP) of the fabric samples was analysed. It was revealed that the fabric weave design and picking sequence has statistically significant effect on fabric wetting time, water spreading speed and AP of the fabric. It was found that fabrics woven in twill weave design and with simultaneous 3PI give significantly better AP, shorter wetting time and better water spreading rate as compared to plain woven fabrics and those with double or SPI. It could be concluded that the thermophysiological comfort of woven fabrics may be significantly improved simply by selecting a suitable weave design and picking sequence.     

Evaluation of Fatty Acid Composition,Tocols Profile,and Oxidative Stability of Some Fully Refined Edible Oils

Present study includes evaluation of fatty acid composition, tocols profile, and oxidative stability of some fully refined edible oils. Fully refined sunflower, soybean, corn, hazelnut, peanut, and canola oils were analyzed for fatty acids by capillary gas liquid chromatography, tocols by normal phase-high performance liquid chromatography and oxidative stability by rancimat. Free fatty acid, peroxide value, and iodine value of investigated oils were determined by titrimetric methods. Saturated, mono-, and polyunsaturated fatty acids were found to be in the ranges between 2.03–18.58, 23.39–77.26, and 14.39–58.52%, respectively. Tocols and oxidative stability of the investigated oils were found to be in the ranges between 488.88–913.51 mg kg^?1 and 3.05–4.99 h, respectively.     

On heated surface transport of heat bearing thermal radiation and MHD Cross flow with effects of nonuniform heat sink/source and buoyancy opposing/assisting flow

Heat transport subject to nonlinear thermal radiation has multiple applications in physics, industry, engineering field, and space technology, such as aerodynamic rockets, solar power technology, large open water reservoirs, and gas-cooled nuclear reactors. This effort studies the magnetohydrodynamic flow of cross fluid, which is a type of non-Newtonian, along a heated surface. Furthermore, the transportation of heat in the fluid is induced by  thermal radiation. Furthermore, the behavior of opposing/assisting flow and impact of nonuniform heat sink/source is scrutinized. The reserved suitable transformations are carried out to shift the ruling equations into nondimensional class. Through reserved transformations, two nonlinear partial differential equations are altered into corresponding nonlinear ordinary differential equations. Then a scheme of integration referred to as Runge–Kutta–Fehlberg is imposed to get a numerical solution of these. The impact of parameters are mentioned concisely on temperature and velocity profiles in the absence and presence of a magnetic parameter. It is proved that the presence of a magnetic field steps up the velocity and temperature as well.     

Multiple characteristics of three-dimensional radiative Cross fluid with velocity slip and inclined magnetic field over a stretching sheet

This article focuses on the three-dimensional Cross fluid flow of a radiative nanofluid over an expanding sheet with aligned magnetic field, chemical reaction, and heat generation phenomenon. The stretching sheet has convective heat and slip boundary conditions. The similarity variables are properly used for the conversion of a dimensional mathematical model into a nondimensional one. The transformed ordinary differential equations are handled for the numerical outcomes of the suggested fluidic model by incorporating the shooting scheme. Furthermore, the numeric investigations are also compared by bvp4c MATLAB built-in package. In a limited case, both the techniques are checked with already published articles, thereby revealing good agreement. Furthermore, the effects of few parameters like Prandtl number, Weissenberg number, heat generation, stretching rate parameter, magnetic parameter, thermal radiation, Brownian and thermophoresis parameters, and Lewis number on concentration, temperature, and velocity profiles have been presented using figures and numerical tables. The strong intensity of the magnetic field across the fluid and increment in the inclination angle (ϑ) result in a lower velocity profile. Temperature is more prominent for the higher slip mechanism. Furthermore, there in an increase in thermophoretic force, which pushes the nanoparticles, and this mixing of nanoparticles helps to increase the concentration profile. A higher Cross fluid index responds to a larger velocity.     

Thermal and thermoelastic problems in dry friction clutch: A comprehensive review

The friction clutch is considered a very important element of machines, as it plays a major role in transferring power from the driving part to the driven part. A common application of the friction clutch is in vehicles to connect between the gearbox and the engine. Fast wear occurs as a result of frictional heating that is generated when the clutch is starting to engage. This wear, in addition to the high thermal stresses, will lead to premature failure in the contacting surfaces. The present review highlights the most important studies of the thermal and thermoelastic problems of friction clutches during the last 10 years to show the challenges that were overcome and also the other challenges that needed to find solutions. The present paper will discuss in detail the influence of the frictional heat generated between contact surfaces during slipping and the main factors affecting the thermal behavior of dry friction clutches, such as sliding speed, friction materials, applied pressure, and so on. Furthermore, significant conclusions and remarks based on the available solutions to the thermal problem of the clutch are presented.     

Exploiting the bioactive properties of essential oils and their potential applications in food industry

Food Science and Biotechnology - Fruits are an abundant source of minerals and nutrients. High nutritional value and easy-to-consume property have increased its demand. In a way to fulfil this...