Effective Filtration Techniques for Gallbladder Ultrasound Images with Variable Contrast

This paper presents a new method of filtering gallbladder contours on static ultrasound images. A major stage in the analysis of ultrasound images is to segment and section off areas occupied by the said organ. In the majority of cases this procedure is a key phase in the process of diagnosing pathological changes in tested organs. Unfortunately ultrasound images present among the most troublesome methods of analysis owing to the echogenic inconsistency of structures under observation. This also applies to the analysis of gallbladder images, chiefly targeted at recognizing changes, which may reveal evidence of developing inflammatory or cancerous changes. This paper provides for an inventive algorithm for the extraction of gallbladder image contours. The algorithm is based on rank filtration, as well as on the analysis of histogram sections on tested organs. The proposed approach of gallbladder image segmentation allows to obtain the effective results of contour detection which exceed 70%. This method is based on two procedures, which independently determine the relevant contour points for both correctly contrasted and vague ultrasound images. The independent results obtained from both procedures when merged allowed for a final determination of a tested organ’s actual shape. Defined in such way morphology makes possible to perform a further classification, which is intended to define certain morbid changes such as inflammation, and cancer. The presented approach based on dynamically adjusted contrast improvement, expand traditional methods of ultrasound images segmentation by additional parallel filtration procedures. As shown in the paper such algorithm is easy scalable and effective.     

Nanoindentation of WC–Co hardmetals

WC–Co cemented carbide has been investigated using instrumented indentation with maximum applied loads from 0.1 to 10 mN. The hardness and indentation modulus of individual phases and the influence of crystallographic orientation of WC on the hardness and indentation modulus have been studied. The hardness of the Co binder was approximately 10 GPa and that of WC grains up to 50 GPa with relatively large scatter under the indentation load of 1 mN. Investigation of the role of crystallographic orientation of WC grains on hardness at 10 mN load revealed average values of H_ITbasal = 40.4 GPa (E_ITbasal = 674 GPa) and H_ITprismatic = 32.8 GPa (E_Itprismatic = 542 GPa), respectively. The scatter in the measured values at low indentation loads is caused by the effects of surface and sub-surface characteristics (residual stress, damaged region) and at higher loads by “mix-phase” volume below the indenter.     

Adsorption and reduction of platinum(IV) chloride complex ions on activated carbon

The adsorption kinetics of platinum(IV) chloride complex ions on the activated carbon Norit GF40 was investigated. Experiments were carried out at different initial concentrations of Pt(IV) chloride complex ions, temperature, rate of mixing and pH. It was found that the value of activation energy of the studied process is equal to 19.7 kJ/mol. From the ICP MS analysis it was confirmed that platinum ions (Pt(IV) and Pt(II)) are removed from the solution due to the adsorption and are further reduced to the metallic state. Such mechanism was confirmed by XPS analysis which showed that on the carbon surface three forms of platinum species, i.e. Pt(0), Pt(II) and Pt(IV), exist. The presence of platinum in the solution at different oxidation states was also confirmed spectrophotometrically by identification of their characteristic absorption bands. The metallic form of Pt present on the surface of activated carbon was observed in the form of small spherical islands with the diameter not exceeding 500 nm. Those islands consist of smaller, flake-shape particles with a thickness of about 35 nm.     

Information technology investment announcements and market value in transition economies: Evidence from Warsaw Stock Exchange

This study examines stock market reactions to announcements of information technology investments in Poland, an emerging market and transition economy. Based on 66 announcements by companies traded at the Warsaw Stock Exchange in the period 2002–2009, our study confirms some previously published results from studies conducted primarily in highly developed markets, but also shows that specific characteristics of announcements play a more important role than has been commonly assumed. Our results indicate that investors in Poland react more positively if systems are acquired from global rather than local vendors. Announcements about completed projects are more positively received than announcements about planned or in-progress projects. Furthermore, announcements in Polish, targeted at existing shareholders, are more likely to be received positively than similar announcements released in English, targeting global investors.     

Microwave plasma‐initiated grafting of acrylic acid on Celgard 2500 membrane to prepare alkaline battery separators—Characteristics of process and product

A process of plasma‐initiated grafting of acrylic acid on commercial porous polypropylene membrane was studied. The influence of parameters of the plasma (power, gas pressure, time plasma‐sample distance, sample arrangement) and grafting (solvent composition, monomer concentration, time, inhibitor presence) on the degree of grafting, amount of homopolymer produced and surface electrical resistance was determined. A degree of grafting up to 18 mmol/g was obtained, which resulted in sample resistance as low as 30 mΩ cm². The molecular weight of AAc homopolymer that can be assumed as equal to the MW of grafted chains, ranged from 25,000 to 50,000,000 da. SEM and water permeability measurements show that grafting causes filling of the pores, which, however, does not stop K⁺ ions from penetrating the membrane. The performance of nickel‐cadmium cells with acrylic acid grafted membranes as separator is also presented. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Progressive failure analysis of unidirectional fiber-reinforced polymers with inhomogeneous interphase and randomly distributed fibers under transverse tensile loading

The effect of damage due to interfacial debonding on the post initial failure behavior of unidirectional fiber-reinforced polymers subjected to transverse tension was investigated using numerical homogenization techniques based on the finite element method. Calculations were performed for unit cells containing fibers distributed at random over the transverse cross-section with inhomogeneous interphase layers. The mechanism of progressive failure was examined at both a global and a local level. A detailed analysis of the proposed micromechanics model revealed that it is able correctly to simulate the evolution of damage and to explain the softening mechanism. It was found that the post initial failure behavior of unidirectional lamina under transverse tension is mainly controlled by the interface strength and the interphase stiffness. The present study showed that local fiber array irregularities are a significant contributor to matrix cracking through local stress concentrations and the occurrence of localization.     

Multiple input–multiple output adaptive feedback control strategies for the active headrest system: design and real‐time implementation

In this article, multiple input–multiple output adaptive feedback control techniques for acoustic noise control in a headrest system are developed. The main goal underlying their design is to provide acoustic comfort to the user, i.e. high noise attenuation level over possibly large areas at the ears. Classical Internal Model Control system does not yield acceptable performance. An approach based on estimates of the residual noise at the ears is then proposed. It is shown that increase in the number of secondary sources to operate for one channel improves the performance. The experiments of tonal noise control are performed on an originally set‐up prototype of the active headrest system. The results obtained are illustrated in the promoted form of distribution of zones of quiet. Copyright © 2003 John Wiley & Sons, Ltd.