Treatment of poultry slaughterhouse wastewaters by electrocoagulation

Treatment of poultry slaughterhouse wastewater (PSW) by electrocoagulation (EC) has been investigated batchwise in this paper. Effects of the process variables such as medium pH, electrode material, current density, and operating time are investigated on chemical oxygen demand (COD) and oil-grease removal efficiencies, electrical energy consumption, and sacrificial electrode consumption. The highest COD removal efficiency is reached with aluminum as 93%, and maximum oil-grease removal is obtained with iron electrodes as 98%. Combined use of both electrode materials in the EC unit may yield high process performances with respect to both COD and oil-grease removals. Further work needs to be carried out at pilot scale to assess the technical end economic feasibility of the process.     

Multiclass support vector machines for EEG-signals classification.

In this paper, we proposed the multiclass support vector machine (SVM) with the error-correcting output codes for the multiclass electroencephalogram (EEG) signals classification problem. The probabilistic neural network (PNN) and multilayer perceptron neural network were also tested and benchmarked for their performance on the classification of the EEG signals. Decision making was performed in two stages: feature extraction by computing the wavelet coefficients and the Lyapunov exponents and classification using the classifiers trained on the extracted features. The purpose was to determine an optimum classification scheme for this problem and also to infer clues about the extracted features. Our research demonstrated that the wavelet coefficients and the Lyapunov exponents are the features which well represent the EEG signals and the multiclass SVM and PNN trained on these features achieved high classification accuracies.     

Estimation of yttrium oxide microstructural parameters using the Williamson–Hall analysis

ABSTRACT

Yttrium oxide (Y₂O₃) particles were synthesised from a yttrium nitrate solution via ultrasonic spray pyrolysis (USP) method. The effects of temperature and precursor concentration on morphology and microstructural parameters were investigated. Y₂O₃ particles were characterised by scanning-electron-microscope energy-dispersive spectroscopy, Raman spectroscopy and X-ray diffraction analysis. Based on X-ray peak broadening, the crystallite size was calculated using the modified Debye–Scherrer (MDS) method. Furthermore, the crystallite size, crystal strain and the energy density of the crystal were evaluated using the Williamson–Hall (W–H) analysis integrated with the uniform deformation model, the uniform stress deformation model and the uniform deformation energy density model. A comparative evaluation of Y₂O₃ crystallite size using the MDS and W–H methods was carried out.

This is part of a thematic issue on Nanoscale Materials Characterisation and Modeling by Advances Microscopy Methods - EUROMAT.     

Sustainable Membrane Production through Polyelectrolyte Complexation Induced Aqueous Phase Separation

Nonsolvent induced phase separation (NIPS) is the most common approach to produce polymeric membranes. Unfortunately, NIPS relies heavily on aprotic organic solvents like N‐methyl‐pyrrolidone. These solvents are unsustainable, repro‐toxic for humans and are therefore becoming increasingly restricted within the European Union. A new and sustainable method, aqueous phase separation (APS), is reported that eliminates the use of organic solvents. A homogeneous solution of two polyelectrolytes, the strong polyanion poly(sodium 4‐styrenesulfonate) (PSS) and the weak polycation poly(allylamine hydrochloride) (PAH), is prepared at high pH, where PAH is uncharged. Immersing a film of this solution in a low pH bath charges the PAH and results in a controlled precipitation, forming a porous water‐insoluble polyelectrolyte complex, a membrane. Pore sizes can be tuned from micrometers to just a few nanometers, and even to dense films, simply by tuning the polyelectrolyte concentrations, molecular weights, and by changing the salinity of the bath. This leads to excellent examples of microfiltration, ultrafiltration, and nanofiltration membranes. Polyelectrolyte complexation induced APS is a viable and sustainable approach to membrane production that provides excellent control over membrane properties and even allows new types of separations.     

Incorporation of organic acids turns classically brittle zein films into flexible antimicrobial packaging materials

This study aimed to turn classically brittle zein films into flexible antimicrobial ones by the use of lactic (LA), malic (MA) and tartaric acids (TA). The most effective plasticizer was LA (400% elongation at break [EB] at 4%), while MA (189% EB at 4.5%) and TA (68% EB at 5%) showed moderate and limited plasticizing effects, respectively. The LA- and MA-loaded films maintained their flexibility during 30-day storage at 4°C or 25°C. Fourier transform infrared (FTIR) analysis suggested that the plasticization of LA and MA could be related to secondary structural changes in zein such as increased α-helix and random coils (mainly by MA) and spaced/modified intermolecular (only by LA) and intramolecular (mainly by MA) β-sheets. Atomic force and scanning electron microscopy showed that LA and MA gave more homogenous and smoother films than TA. Films with LA showed the highest water vapour permeability followed by those of control, MA- and TA-loaded films. Films with 3%–4% LA or MA formed clear zones on Listeria innocua and Klebsiella pneumonia, but only films with LA formed clear zones on Escherichia coli. All OA-loaded films gave unclear zones on Staphylococcus aureus in disc-diffusion tests, but this bacterium was inactivated rapidly in antimicrobial tests based on surface inoculation tests. LA is the best OA to develop flexible antimicrobial films from zein, an industrial by-product that films could not have been utilized as a widespread packaging material due to their brittleness.     

Unsupervised face recognition in the wild using high-dimensional features under super-resolution and 3D alignment effect

Face recognition algorithms customarily utilize query faces captured from uncontrolled, in the wild, environments. The quality of these facial images is affected by various internal factors, including the quality of sensors used in outdoor cameras as well as external ones, such as the quality and direction of light. These factors adversely affect the overall quality of the captured images often causing blurring and/or low resolution, a phenomena commonly referred to as image degradation. Super-resolution algorithms are highly effective in improving the resolution of degraded images, more so if the captured face is small requiring scaling up. With this motivation, this research aims at demonstrating the effect of one of the state-of-the-art image super-resolution algorithms on the labeled faces in the wild (lfw) dataset. In this regard, several cases are analyzed to demonstrate the effectiveness of the super-resolution algorithm. Each case is then investigated independently comparing the order of execution before or after the 3D face alignment step. Following this, resulting images are tested on a closed set face recognition protocol using unsupervised algorithms with high-dimensional extracted features. The inclusion of super-resolution resulted in improvement in the recognition rate compared to unsupervised algorithm results reported in the literature.     

Analysis of human PPG,ECG and EEG signals by eigenvector methods

This paper presents eigenvector methods for analysis of the photoplethysmogram (PPG), electrocardiogram (ECG), electroencephalogram (EEG) signals recorded in order to examine the effects of pulsed electromagnetic field (PEMF) at extremely low frequency (ELF) upon the human electrophysiological signal behavior. The features representing the PPG, ECG, EEG signals were obtained by using the eigenvector methods. In addition to this, the problem of selecting relevant features among the features available for the purpose of discrimination of the signals was dealt with. Some conclusions were drawn concerning the efficiency of the eigenvector methods as a feature extraction method used for representing the signals under study.     

Microfiltration of whey proteins adsorbed on yeast cells

Soluble whey proteins (WPs), adsorbed on yeast cells, were recovered by a crossflow microfiltration (MF) technique using a cellulose nitrate membrane with a pore size of 0.45 μm. The crossflow velocity was 1.5 m s^?1 with a transmembrane pressure of 200 kPa at 25 °C. A series of protein rejections occured at various pH values ranging from 2 to 8. WPs adsorbed more on to yeast cells at low pH (pH < 4) than at high pH values, probably because they were positively charged at low pH. It was also shown that permeate flux increased and Modified Membrane Fouling Index values decreased at low pH levels. When the yeast concentration was 50 g L^?1, the flux decreased five times compared with that in the absence of yeast. Protein recovery increased with increasing yeast concentrations. The highest protein recovery was found to be 85% at a yeast concentration of 50 g L^?1 at a steady state flux rate of 10^?6 m s^?1 at 25 °C. When diluted solutions of whey were used, the same rejection of protein, adsorbed on yeast cells, was achieved at ten times lower amounts of yeast cells. This technique not only provides for the recovery of protein but also may give rise to the direct use of yeast cells, which are rich in protein, in the baking industry. WPs absorbed by yeast cells can be used to produce nutritionally rich products in areas where yeasts have been already used.     

Neighborhoods of a new class of harmonic multivalent functions

We introduce and investigate a new subclass of harmonic multivalent functions defined by using a differential operator. We obtain coefficient conditions, distortion bounds, extreme points, convex combination for the above class of harmonic multivalent functions. We also, derive inclusion relationships involving the neighborhoods of harmonic multivalent functions.