Applications and opportunities for ultrasound assisted extraction in the food industry — A review

Ultrasound assisted extraction (UAE) process enhancement for food and allied industries are reported in this review. This includes herbal, oil, protein and bioactives from plant and animal materials (e.g. polyphenolics, anthocyanins, aromatic compounds, polysaccharides and functional compounds) with increased yield of extracted components, increased rate of extraction, achieving reduction in extraction time and higher processing throughput. Ultrasound can enhance existing extraction processes and enable new commercial extraction opportunities and processes. New UAE processing approaches have been proposed, including, (a) the potential for modification of plant cell material to provide improved bioavailability of micro-nutrients while retaining the natural-like quality, (b) simultaneous extraction and encapsulation, (c) quenching of the radical sonochemistry especially in aqueous systems to avoid degradation of bioactives and (d) potential use of the radical sonochemistry to achieve targeted hydroxylation of polyphenolics and carotenoids to increase bioactivity.Industrial relevanceThe application of ultrasonic assisted extraction (UAE) in food processing technology is of interest for enhancing extraction of components from plant and animal materials. This review shows that UAE technology can potentially enhance extraction of components such as polyphenolics, anthocyanins, aromatic compounds, polysaccharides, oils and functional compounds when used as a pre-treatment step in a unit process. The higher yield obtained in these UAE processes are of major interest from an industrial point of view, since the technology is an “add on” step to the existing process with minimum alteration, application in aqueous extraction where organic solvents can be replaced with generally recognised as safe (GRAS) solvents, reduction in solvent usage, and shortening the extraction time. The use of ultrasonic for extraction purposes in high-cost raw materials is an economical alternative to traditional extraction processes, which is an industry demand for a sustainable development.     

A formal approach to negotiating agents development

This paper presents a formal and executable approach to capture the behaviour of parties involved in a negotiation. A party is modeled as a negotiating agent composed of a communication module, a control module, a reasoning module, and a knowledge base. The control module is expressed as a statechart, and the reasoning module as a defeasible logic program. A strategy specification therefore consists of a statechart, a set of defeasible rules, and a set of initial facts. Such a specification can be dynamically plugged into an agent shell incorporating a statechart interpreter and a defeasible logic inference engine, in order to yield an agent capable of participating in a given type of negotiations. The choice of statecharts and defeasible logic with respect to other formalisms is justified against a set of desirable criteria, and their suitability is illustrated through concrete examples of bidding and multi-lateral bargaining scenarios.     

Understanding the interplay between cathode catalyst layer porosity and thickness on transport limitations en route to high-performance PEMFCs

We examine the interplay between cathode catalyst layer (CL) porosity/thickness on mass transport limitations in single cell fuel cells comprised of Pt/C-based CLs fabricated via ultrasonic spray deposition onto polymer electrolyte membranes. We determine that the pore size distribution remains unchanged as CL thickness increases from 3.8 to 11.8 μm, but porosity decreases with increasing CL thickness. The decrease in porosity results in an increase in mass transport resistance for thicker CLs, but does not result in an increase in charge transfer resistance for the oxygen reduction reaction. We found that a fuel cell comprising a 7.5 μm-thick cathode CL delivers the highest performance (1 A cm⁻² at 0.60 V at 80 °C in H₂|Air at a relative humidity of 50% under ambient pressure). We attribute this high performance to the CL striking an optimal balance between solid and void networks, with the solid networks facilitating transport of H⁺/e⁻ to the Pt electrocatalyst, and the void network ensuring adequate transport of O₂ to, and H₂O away from, the Pt electrocatalyst.     

Remarkable improvement in the activity and stability of Pd/HZSM-5 catalyst for methane combustion

A novel Pd/HZSM-5 catalyst was prepared first by glow discharge plasma treatment followed by calcination thermally. Such prepared catalyst shows a higher activity and an enhanced stability for methane combustion. The XRD characterization and XPS analysis confirm that the plasma preparation leads to a better preparation of PdO active species over the HZSM-5 support. Especially, a plasma-enhanced acidity has been achieved upon the FT-IR analysis. The enhanced acidity plays an important role in stabilizing the dispersed PdO active species on the zeolite support.     

Mechanical properties of nitrogen-doped CZ silicon crystals

We investigated the effect of the nitrogen doping level on plastic properties of 300 mm silicon material in the temperature range between 650°C and 1000°C. Undoped, low N-doped, and high N-doped materials were examined. The dependence of the upper and lower yield point and the size dependence of indentation related dislocation rosettes on temperature were obtained.An increase in the nitrogen concentration leads to enhanced upper and lower yield points. Possible mechanisms of interaction of dislocations with impurities resulting in hardening of silicon single crystals are discussed. Finite element method (FEM) calculated data of bearing stress observed in 300 mm Si wafers annealed in a vertical furnace are compared with measured upper yield point values. At high nitrogen concentration the tolerable process temperatures, where plastic flow of Si wafers under load can be avoided, are significantly increased.     

Parametric studies on a metal hydride based single stage hydrogen compressor

Influence of operating parameters such as heat source and sink temperatures, operating pressures, pressure ratios, cycle time, and bed parameters such as overall heat transfer coefficient, bed thickness and thermal conductivity, on the performance of a single stage hydrogen compressor is presented. Coupled heat and mass transfer and reaction kinetics are considered for the analysis. An AB₂-type alloy, Ti_0.98Zr_0.02V_0.43Fe_0.09Cr_0.05Mn_1.5 is chosen as an example. At a given pressure ratio, the hydrogen throughput increases with hot fluid temperature and decreases with increase in cold fluid temperature. Optimum values of thermal conductivity and overall heat transfer coefficient exist for any given hot and cold fluid temperatures. Among the variables studied, heat transfer fluid temperature, bed thickness and supply pressure are found to exert significant influence on the compressor performance.     

Optimising water activity for storage of high lipid and high protein infant formula milk powder using multivariate analysis

High lipid and high protein infant formula milk powders were stored at water activity of 0.11, 0.33 and 0.53 for up to fourteen weeks at 40 °C to investigate the effect of storage water activity on physicochemical properties and formation of volatiles to thereby recommend optimal storage water activity conditions. Water activity of the powders was determined during storage together with surface colour, glass transition temperature combined with dynamic headspace sampling followed by gas chromatography/mass spectrometry. The principal component analysis (PCA) showed that the optimal water activity for storage of high lipid infant formula milk powder, for which lipid oxidation was found to be the critical quality parameter, is a_w = 0.33 with lowest lipid oxidation, while for high protein infant formula milk powder, for which protein degradation was found to be the critical quality parameter, a_w = 0.11 is optimal to limit formation of Maillard reaction products.     

High carrier mobility and remarkable photovoltaic performance of two-dimensional Ruddlesden–Popper organic–inorganic metal halides (PA)2(MA)2M3I10 for perovskite solar cell applications

Two-dimensional Ruddlesden–Popper (2DRP) metal halides have attracted extensive attention in photovoltaic applications due to their high stability, low self-doping levels and long-lived free carriers. Among them, (PA)₂(MA)₂Pb₃I₁₀ presents itself as a superior candidate, demonstrating greater moisture resistance and improved heat and light stability over many other 2DRP metal halides. This study takes on the opportunity to search for lead-free alternatives by investigating the optoelectronic and carrier transport properties, as well as the photovoltaic performance of such (PA)₂(MA)₂M₃I₁₀ type metal halides as the photovoltaic absorber, where M = Pb, Cd, Cr, Cu, Ge, Mn, Ni, Sn, Yb, Zn. Our results indicate that the bandgap of (PA)₂(MA)₂M₃I₁₀ can be tuned to the optimum photovoltaic application range of 0.9–1.6 eV, along with improved optical and enhanced photo-response capacity, when Sn, Cd, Mn, Ge, and Zn are used to replace Pb. In particular, (PA)₂(MA)₂Zn₃I₁₀ possesses the largest Stokes shift and Huang-Rhys factor, while showing the best photoluminescence tendency and broadest emission nature. (PA)₂(MA)₂Ge₃I₁₀ displays the most excellent of carrier transport capacities with high mobilities of 73 cm² V⁻¹ s⁻¹ and 43 cm² V⁻¹ s⁻¹ for electron and hole carriers, respectively, which are even comparable to that of 3D counterparts. Furthermore, (PA)₂(MA)₂Zn₃I₁₀ is predicted to have the highest power conversion efficiency of 23.36% based on an empirical energy loss (0.5 eV), which is quite close to the Shockley–Queisser limit, thereby featuring it as a suitable absorber for photovoltaic applications. These findings shed light on new strategies for designing and developing lead-free 2DRP metal halides targeted at future applications in photovoltaic solar cell devices.     

Combined Study on Mold Taper and Corner Radius in Bloom Continuous Casting by FEM Simulation and Trial Experiment

Metals and Materials International - A plane stress model was developed to study the coupled effect of mold taper and corner radius on the thermal–mechanical behavior of a...     

Single-step synthesis of novel chloroaluminate ionic liquid for green Friedel–Crafts alkylation reaction

Clean Technologies and Environmental Policy - Friedel–Crafts alkylation reactions constitute a very important class of reactions which are usually catalysed in the liquid phase using Lewis...