Removal of iron from milk of lime to produce pure precipitated calcium carbonate

ABSTRACT

Milk of lime (MOL) suspension is widely utilized in many industries; however, in some of the applications, such as the production of precipitated calcium carbonate (PCC), the suspension must be of high purity and quality. In other words, the amounts of iron and magnesium should be so little so that the final PCC product would be of high quality. The effects of initial temperature, quicklime particle size, amount of initial solid present, agitation rate, and time on the recovery of hydrated lime and iron/magnesium reduction efficiency were investigated through a central composite design (CCD) of experiments. The iron reduction efficiency and the weight recovery of hydrated lime were obtained as 91% and 98.5%, respectively. The reduction of magnesium was not significant in this stage. Moreover, approximately the whole existing SiO₂ was eliminated.     

Physicochemical assessment of fresh chilled dairy dessert supplemented with wheat germ

Wheat germ is an available and economical source of protein, vitamins and antioxidants with an increasing application in food products. The main aim of this study was to investigate the effects of different levels (0.0, 2.5, 5.0, 7.5 and 10.0%) and particle sizes (120, 210 and 354 μm) of wheat germ on physicochemical properties of fresh chilled dairy dessert. With increasing wheat germ level, dry matter of the dessert increased while the pH decreased. Particle size had no significant effect on these parameters. Increasing the wheat germ content and particle size enhanced darkness, hardness, cohesiveness and gumminess of the desserts while decreasing springiness and water release of the samples. Wheat germ level had greater effects on different quality aspects of the desserts than its particle size. The most acceptable dessert was produced with no more than 5.0% wheat germ with either of the particle sizes used in this study.     

Next-generation 10 GBaud module based on emerging SFP+ with host-based EDC [Topics in Optical Communications]

There has been an ongoing trend to require transceivers for use in datacom and telecom switches to be small and have low power dissipation to enable large port count switches. At speeds between 1 and 4 GBaud the SFP form factor is by far the most commonly used. Up to now 10 GBaud transceivers have used larger devices with larger power dissipations. This article describes the SFP+ module being specified by the SFF Committee (SFF 8431) that will enable the same port densities as the SFP module. The adaptive equalizers and high-speed transmission channels required in the switches to make the SFP+ module work successfully are also described     

Synthesis,characterization and immobilization of iron (III) pyridoxinato complex within Al-MCM-41 as catalyst for cycloalkanes oxidation

Biomimetic [Fe(pyridoxinato)₂OH·(H₂O)₃] non-hem complex designated as [Fe(L)₂OH·(H₂O)₃] was synthesized with basic solution of pyridoxine (Vitamin B₆) and FeCl₃ in methanol under reflux condition. It was then immobilized within the Al-MCM-41. Characterizations were carried out by powder X-ray diffraction, nitrogen adsorption desorption, FTIR and UV–Vis spectroscopy. It was found that pore volume, surface area, and pore diameter of Al-MCM-41 decreases after immobilization of iron complex. Density functional theory studies confirmed the experimental results of [Fe(L)₂OH·(H₂O)₃] complex. Fe-complex/Al-MCM-41 was found to successfully catalyze the oxidation of cyclohexane, cyclooctane and adamantane using H₂O₂ as oxidant with 45–90 % conversion toward the corresponding alcohols and ketones is considerable.     

State Estimation For An Agonistic‐Antagonistic Muscle System

Research on assistive technology, rehabilitation, and prosthetics requires the understanding of human machine interaction, in which human muscular properties play a pivotal role. This paper studies a nonlinear agonistic‐antagonistic muscle system based on the Hill muscle model. To investigate the characteristics of the muscle model, the problem of estimating the state variables and activation signals of the dual muscle system is considered. In this work, parameter uncertainty and unknown inputs are taken into account for the estimation problem. Three observers are presented: a high gain observer, a sliding mode observer, and an adaptive sliding mode observer. Theoretical analysis shows the convergence of the three observers. Numerical simulations reveal that the three observers are comparable and provide reliable estimates.     

Progressive Collapse Analysis of Cable-Stayed Bridges

Journal of Failure Analysis and Prevention - Several codes have proposed guidelines to prevent progressive collapse. Although most of these standards are in progress, few recommendations for...     

Who profits from the Canadian nanotechnology reward system? Implications for gender-responsible innovation

Scientometrics - Gender equality is one of the primary dimensions of responsible research and innovation. Based on bibliometric and survey data of nanotechnology researchers in Canada, this paper...     

A hybrid discontinuous spectral element method and filtered mass density function solver for turbulent reacting flows

Abstract

We present a novel hybrid scheme for the large eddy simulation (LES) of turbulent reacting flows. The scheme couples the discontinuous spectral element method (DSEM) solver for the unsteady compressible Navier-Stokes equations with a Monte Carlo particle filtered mass density function (FMDF) solver for the transport of reacting species. The method is capable of high-order simulations on unstructured grids. Mean particle estimate construction mimics the DSEM numerical procedure and utilizes variable basis functions. The scheme is tested on non-reacting and reacting Taylor-Green vortex flows. Studies of varying polynomial order, different basis functions for constructing particle estimates, and varying particle quantities are conducted. We demonstrate that a tent kernel, in conjunction with high polynomial order, produces the most accurate results. The chemically reacting simulations validate the hybrid scheme and demonstrate its applicability across a range of reaction regimes. The hybrid scheme's computational cost is 2.1 times the DSEM-LES solver.