The effects of ozone,ultrasound and coating with shellac and lysozyme–chitosan on fresh egg during storage at ambient temperature – part 1: interior quality changes

The objective of this research was to investigate and compare the effect of different treatments including gaseous ozone (6-ppm/4-min), ultrasound (450 W/4 min) and coating of shellac, lysozyme–chitosan (L-C) on fresh eggs internal quality during storage for six weeks at ambient temperature. The internal quality attributes such as weight loss (WL), albumen viscosity, Haugh unit (HU), yolk index, total soluble solids, albumen and yolk's pH were monitored. Control groups had the worst HU (50.04), WL (8.35%), albumen pH (9.27) and viscosity (7.72 mPa·s) values after storage. The best interior qualities were obtained by shellac coating [HU (72.37), WL (1.37) and viscosity (30.10 mPa·s)] and sonication (albumen pH: 8.22). Thus, the shellac-coated eggs maintained all the internal quality parameters at the highest values, while the ozone and ultrasound only helped to keep the internal quality and enhance the shelf life of eggs.     

Robust microencapsulated phase change materials in concrete mixes for sustainable buildings

For passive building applications, phase change materials (PCMs) are microencapsulated to avoid leakage of PCM from concrete structure. The primary challenge of using microencapsulated PCM (MPCM) is its weak shell structure. New MPCMs with different shell compositions to prevent breakage during mixing in fresh concrete are needed. In this study, free radical polymerization method to microencapsulate capric acid–myristic acid mixture as PCM with two different methyl methacrylate co‐polymers is proposed to produce robust MPCMs for building applications. Two new microcapsules (MPCM‐1 and MPCM‐2) having latent heats of 91.9 and 97.3 J/g were synthesized. SEM analyses showed the size of microcapsules being in the range of 400–850 nm for MPCM‐1 and 250–475 nm for MPCM‐2. Analyses also reveal that the shells of MPCMs were not harmed, as they were added into concrete mixes. The microsphere's geometry was preserved, and distribution was homogeneous. The MPCMs were also studied under thermal tests of 1000 heating/cooling cycles. No significant changes in thermal properties were observed after thermal cycling tests. Copyright © 2016 John Wiley & Sons, Ltd.     

Interference analysis and capacity for forward link 3G CDMA network with adaptive antennas

In code division multiple access (CDMA) systems, the capacity of forward link (FL) communication to mobile receivers is limited primarily by co‐channel interference (CCI). Adaptive antenna arrays (AAAs) that use antenna arrays along with advanced signal processing at the base station (BS) have been proposed to mitigate this limitation. For a 3G CDMA cellular network, where each BS equipped with an AAA serves mixture of voice and data users within its coverage, we study FL capacity and investigate the effects of different factors (array topology, multipath angle spread, data rate, and beamforming algorithm) on this capacity under Rayleigh fading channel. By modeling the instantaneous signal‐to‐interference power ratio received at the mobile, we derive the system outage equation that considers blocking of either desired voice or data user. Simulation results show that for the same element spacing and number of antenna elements per cell, the uniform circular array (UCA) topology results in larger capacity than the sectorized uniform linear array (ULA) topology does, and that a larger angle spread or data user rate reduces FL capacity. Copyright © 2007 John Wiley & Sons, Ltd.     

Consumer complaints and accidents related to food packaging

This study investigated consumer complaints related to food packaging design and the occurrence of injuries associated with the opening of various types of containers. Each study participant (245) took a 15 min fact‐to‐face interview and was asked attitudinal questions about 10 different categories of packaging including cans, glass and plastic bottles and jars, and paper‐based composite packages. The subjects were also asked whether they had been injured while opening these packaging types. The survey showed that cans which needed a tool for opening were most difficult to enter. In some cases the tool was the source of injury. The respondents were also most concerned about deformation, spillage and product wastage associated with these types of containers. This included brick‐type composite packages without a peelable seal over the pour spout. A large percentage of the respondents felt that more information was needed on the various methods of opening packages in general. Glass bottles and jars were most likely to be used for storage of products after they were emptied of their original contents. The results of this study could be used by manufacturers to assist them in the design and development of packaging with a lower potential to cause accidents and injuries. Copyright © 2010 John Wiley & Sons, Ltd.     

Understanding the effects of various edible coatings on the storability of fresh cherry

n this work, cherries, which have a very short shelf life, were packaged after being coated with various edible coatings [whey protein isolate (WPI), chitosan and shellac]. The changes in gas composition, weight loss, Brix, pH, electrical conductivity and firmness were measured periodically up to 11 days after harvest to compare the effects of the applied coatings. Fourier transform near‐infrared (FT‐NIR) spectroscopymeasurements were also taken individually. After storage, the gas composition within trays was about 1–10% O₂ and 14–47% CO₂. The lowest weight loss (25.56%) was observed in the shellac‐coated cherries, while the highest loss (48.58%) occurred in the control group. Coated cherries exhibited a significantly lower pH and electrical conductivity than the uncoated ones. The control group presented the highest total soluble solid (TSS) values (21.29) and shellac coating had (17.25) the lowest. At the end of storage, the highest ascorbic acid (AA) content was 0.64 mg/100 ml in the shellac‐coated cherries, and the lowest AA content of 0.40 mg/100 ml was measured in the control group. Firmness was maintained by coating, especially with shellac (3.734 N), whereas the control had the lowest firmness measured (2.138 N) at the end of storage. There were differences between the absorbance spectra for the coated and control cherries at the end of storage. This research concludes that shellac coating is more effective in reducing the respiration rate and maintaining the quality parameters of cherries than chitosan and WPI coatings. Major benefits of coatings were observed in lessening the weight‐loss process and in maintaining firmness, which were also supported by the FT‐NIR measurements. Copyright © 2010 John Wiley & Sons, Ltd.     

Nonlinear 3D finite element simulation of reinforced concrete flat plates retrofitted with externally bonded CFRP strips

In this study, a comprehensive 3D non-linear finite element modelling procedure is presented for the simulation of reinforced concrete flat plates, retrofitted with externally bonded carbon fibre-reinforced polymer (CFRP) strips and subjected to punching shear loads. The presented modelling procedure may be used to conduct parametric numerical analyses on the response of reinforced concrete elements similar to considered in this study. The modelling procedure is applied on: (i) a solid, un-retrofitted flat plate and (ii) eight flat plates with openings and retrofitted with externally bonded CFRP strips. In the procedure, debonding of CFRP strips from concrete surfaces is accounted for by defining appropriate bilinear shear stress–slip and normal stress–gap relationships. In the model, the corner lift-offs observed at the corners of the flat plates are also considered by defining appropriate restrains and frictional support conditions. Results obtained from the proposed modelling procedure are verified using experimental data available in the literature. From the verification, accuracy of the proposed modelling procedure is confirmed in terms of structural responses such as load displacement relationships and crack propagations of the test specimens.     

A novel silk fibroin‐supported iron catalyst for hydroxylation of phenol

The aim of this study was to explore the potential use of silk fibroin (SF) as a catalyst support material for phenol hydroxylation reactions. Iron‐substituted silk fibroin fibers were prepared using formic acid at room temperature and characterized using inductively coupled plasma atomic‐emission spectrometry, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and optical microscopy. Measurement of an FTIR spectrum showed that the secondary structure was β‐structure before and after iron substitution. To evaluate the catalytic properties of prepared catalyst, phenol hydroxylation reaction was carried out using aqueous hydrogen peroxide as an oxidant. An excellent transformation of phenol into dihydroxybenzenes (catechol and hydroquinone) was achieved. Phenol conversions of 3.3%, 61.2%, and 80.3% were obtained at room temperature, 40 °C and 60 °C respectively. It was found that no further phenol conversion proceeded because catalysts became separated from the reaction system during the reaction. No significant leaching of the iron was detected. Catalyst could be reused several times without a significant change in activity. Parent silk fibroin fibers without iron were inactive. Copyright © 2006 Society of Chemical Industry