A low-noise-figure 1.5 μm multiple-quantum-well opticalamplifier

The authors report on the noise characteristics of InGaAs/InGaAsP multiple-quantum-well optical amplifiers operating near 1.5 μm. A noise figure of 4.4 dB is reported, verifying the predicted low-noise properties of quantum-well amplifiers     

Modal analysis of prestressed draft pad of freight wagons using finite element method

The present work intends to investigate dynamic behaviour of draft gear using finite element method. The longitudinal force that the draft gear absorbs usually leads to the failure of its components, especially, the load bearing draft pads. Dynamic behaviour of an individual draft pad and a draft gear is determined and characterized with exciting frequencies and corresponding mode shapes. The effect of compressive prestress load on the dynamic behaviour of an individual draft pad is also determined as the draft pads in assembled state are under constant axial compressive force in the draft gear. The vibration characteristics of individual draft pad are compared with draft pads that are part of draft gear. The modal analysis gives us a basis for subjecting a draft pad to higher frequency loading for determining its fatigue behaviour.

     

Deposition of hydroxyapatite coatings by axial plasma spraying: Influence of feedstock characteristics on coating microstructure,phase content and mechanical properties

Axial plasma spray is one of the thermal spray techniques to deposit multifunctional advanced coatings. The present work explores the use of this process to deposit thin, continuous, and adherent Ca₅ (PO₄)₃OH (hydroxyapatite, HAp) coatings and characterize its microstructure, phases, hardness and adhesion strength. Three different suspension-deposited HAp coatings were investigated and compared with powder-deposited HAp coating on a Ti6Al4V substrate. The effect of mean solute particle size and solid-loading in the suspension has been explored on the evolution of microstructure, phase content and mechanical properties of axial suspension plasma sprayed (ASPS) coatings. Phase-characterization has shown retention of hydroxyapatite phase and coating crystallinity in the deposited coatings, whereas the adhesion strength of the HAp coating decreased from ～40 MPa to ～13 MPa when bioglass was added to the feedstock material. The lower solid load content and lower mean solute particle size in the suspension were found to be beneficial in achieving porous, rougher, and well-adhering coatings. This work concludes that ASPS can potentially deposit thin HAp coatings (< 50 μm) with high adhesion strength.     

Development of microbiologically safe mung bean sprouts using combination treatment of sodium hypochlorite and gamma radiation

Specific group of people, with impaired immune system, are recommended to consume pathogen‐free foods. In this study, microbiologically safe ready‐to‐eat (RTE) mung bean sprouts were developed using combination treatment (CT) with 200 ppm sodium hypochlorite and 12 kGy dose of gamma radiation. Microbiological analysis of combination‐treated sprout samples showed complete elimination (<10 CFU g^?1 of sprouts) of microbial load in these samples, even during storage at 4 °C up to 12 days. Combination treatment and storage period did not have any significant effect on the sensory qualities of RTE mung bean sprouts. However, reduction in the firmness and vitamin C content of combination‐treated sprout samples, similar to other food processing methods, was observed. These results suggest that CT is effective in sterilisation of mung bean sprouts. These sprouts can be included in the diets of special target groups and thereby improve in their quality of life.     

Thermal and aqueous stability improvement of graphene oxide enhanced diphenylalanine nanocomposites

Abstract

Nanocomposites of diphenylalanine (FF) and carbon based materials provide an opportunity to overcome drawbacks associated with using FF micro- and nanostructures in nanobiotechnology applications, in particular their poor structural stability in liquid solutions. In this study, FF/graphene oxide (GO) composites were found to self-assemble into layered micro- and nanostructures, which exhibited improved thermal and aqueous stability. Dependent on the FF/GO ratio, the solubility of these structures was reduced to 35.65% after 30 min as compared to 92.4% for pure FF samples. Such functional nanocomposites may extend the use of FF structures to e.g. biosensing, electrochemical, electromechanical or electronic applications.     

Sustainable recovery of grape skins for use in an apple beverage with antiglycation properties

An apple puree formulated with red grape skins was developed on pilot scale as a new beverage with antiglycation properties. The addition level of grape skins was selected by a liking test with 70 consumers. The selected formulation was a fibre‐rich source and delivered grape anthocyanins, flavonols and flavanols resulting in ~ twofold higher antiglycation activity than the apple puree. Pasteurisation (3‐D in the target microorganism Alicyclobacillus acidoterrestris) did not affect the antiglycation activity, which decreased by 30% upon sterilisation. Storage for 1 month in the temperature range 15–35 °C affected the contents of anthocyanins, monomeric, dimeric and oligomeric flavanols, while chlorogenic acid, flavonols and dihydrochalcones were stable. About 90% antiglycation activity was retained after one‐month storage at 15 °C. The use of red grape skin as ingredient could represent an opportunity for the apple processing industry to develop a value‐added product.     

Properties of Noncentral Dirichlet Distributions

Let X₁,…, X_r+1 be independent random variables, X_iGa (a_i, θ, δ_i), i = 1,…, r + 1. Define and V_i = X_i/X_r+1, i = 1,…, r. Then, (U₁,…, U_r) and (V₁,…, V_r) follow noncentral Dirichlet Type 1 and Type 2 distributions, respectively. In this article several properties of these distributions and their connections with the uniform, the noncentral multivariate-F and the noncentral multivariate-t distributions are discussed.     

Intelligent System for Adapting to a User’s Characteristics

In this paper, we propose an intelligent system that adapts itself to a user’s characteristics or habits. The proposed intelligent system is composed of two Learning Vector Quantisation (LVQ) networks, commonly used in the fields of pattern recognition and signal processing. From the external condition of the plant, the first LVQ network learns to recognise the pattern of the sensed signal, and then aids the second LVQ to learn the user’s characteristics or habits so as to automatically produce the user’s favoured output. To verify the usefulness of the proposed method, we simulated and experimented with a variable illuminator. Both simulation and experimental results showed that the proposed intelligent system learns to automatically produce the illuminator output that the user most favours for the circumstances.