Influence of Cu<Superscript>2+</Superscript> ions on structural and magnetic properties of NiZn ferrites

The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by means of ceramic technology. The influence of small Cu substitution on the microstructural and magnetic properties of NiZn ferrites have been analysed by means of various experimental methods and interpreted from the point of view of preparation technology optimisation and possible applications of such materials. A strong correlation between the substituent content and resulting properties has been observed, thus allowing preparation of material with the properties tailored for any particular application.     

Fast Motion Estimation Algorithm with Edge Alignment for H.264 Encoder

Image sequences processing and video encoding are extremely time consuming problems. The time complexity of them depends on image contents. This paper presents an estimation of a block motion method for video coding with edge alignment. This method uses blocks of size 4 × 4 and its basic idea is to find motion vector using the edge position in each video coding block. The method finds the motion vectors more accurately and faster than any known classical method that calculates all the possibilities. Our presented algorithm is compared with known classical algorithms using the evaluation function of the peak signal-to-noise ratio. For comparison of the methods we are using parameters such as time, CPU usage, and size of compressed data. The comparison is made on benchmark data in color format YUV. Results of our proposed method are comparable and in some cases better than results of standard classical algorithms.     

Efficient encryption of wavelet-based coded color images

An efficient, secure color image coder incorporating Color-SPIHT (C-SPIHT) compression and partial encryption is presented. Confidentiality of the image data is achieved by encrypting only the significance bits of individual wavelet coefficients for K iterations of the C-SPIHT algorithm. By varying K, the level of confidentiality vs. processing overhead can be controlled. For K=2, adequate security is achieved and an average of only 0.40% of bits needed encrypting for test images coded at 0.8 bpp.     

A rapid method for determination of l-lactic acid in real samples by amperometric biosensor utilizing nanocomposite

Amperometric biosensors based on gold planar electrode and on two types of nanocomposite electrodes consisting of multi-walled carbon nanotubes for determination of l-lactic acid designed for wine-makers were developed and used for an analysis of real food samples and beverages. The biosensors were constructed by immobilization of l-lactate oxidase and peroxidase within chitosan layers on the surface of the electrodes. As a mediator, ferrocyanide was used. The current resulted from re-oxidation of produced ferricyanide was measured at working potential of −50 mV against Ag/AgCl reference electrode. The biosensor based on gold electrode showed linearity over the range 5-244 μM with the detection limit of 0.96 μM. Calibration curves for biosensors utilizing two types of nanocomposites consisting of N-eikosane and multi-waled carbon nanotubes (d = 60-100 nm, L = 5-15 μm, 95+% purity or d = 9.5 nm, L = 1.5 μm, 90+% purity) were obtained both with the linear range of 5-340 μM. The detection limits were 1.62 and 1.66 μM, respectively. All types of biosensors had response time of 65s. The biosensors showed satisfactory operational stability (no loss of sensitivity after 60 consecutive measurements) and an excellent storage stability (90% of the initial sensitivity after 15 months of storage at room temperature). Finally the results obtained from measurements of food and wine samples were compared with those obtained with an enzymatic-spectrophotometric and standard HPLC method. The biosensors based on 3 different configurations were able to determine low concentration (0.02-0.12 g L⁻¹) of lactic acid level, what was not possible by reference analytical methods and a comparison between results obtained by the biosensors and reference methods agreed very well at concentration of lactic acid above 1.4 g L⁻¹.     

Monitoring of monosaccharides,oligosaccharides, ethanol and glycerol during wort fermentation by biosensors,HPLC and spectrophotometry

The aim of the present study was to analyze sugar levels (namely maltose, maltotriose, glucose and fructose) and alcohols (ethanol and glycerol) during the fermentation process in wort samples by amperometric enzymatic biosensors developed by our research group for industrial application, HPLC and spectrophotometry, and to compare the suitability of the presented methods for determination of individual analytes. We can conclude that for the specific monitoring of maltose or maltotriose only the HPLC method was suitable. On the other hand, biosensors and spectrophotometry reflected a decrease in total sugar concentration better and were able to detect both glucose and fructose in the later stages of fermentation, while HPLC was not. This can be attributed to the low detection limits and good sensitivity of the proposed methods. For the ethanol and glycerol analysis all methods proved to be suitable. However, concerning the cost expenses and time analysis, biosensors represented the best option.     

Market power and welfare effects in DC power flow electricity models with thermal line losses

A nodal electric power network with Cournot–Nash interaction among power generators is formulated as a mixed complementarity problem. The model incorporates a direct current (DC) power flow approximation with thermal line losses to model real-time flows. We include constant wheeling rate and variable congestion charges for transmission of electricity. Market power and welfare effects are measured in an aggregated Indiana electric grid model. We find that imposing DC power flow constraints in a model results in significant changes in social welfare estimates. Line losses are also an important factor affecting market power and welfare of market participants in the case study.     

Single-sensor imaging in consumer digital cameras: a survey of recent advances and future directions

This paper surveys in a systematic way recent advances in single-sensor imaging. In particular, the most distinctive elements of a single-sensor imaging pipeline, such as color filter array configurations, image interpolation solutions, and picture storage approaches are reviewed and commented upon. New perspectives in the field are proposed, suggesting that the demand for consumer digital camera solutions and digital color imaging applications will continue.