Effect of isosorbide dinitrate on pulmonary venous compliance

Irreversible poor pulmonary venous compliance (PV comp) could worsened natural course of patients (pts) with high pulmonary capillary wedge pressure especially pts with mitral stenosis. Nitrates (isosorbide dinitrate-ISDN) possessing venous dilating action could increase PV comp in most of pts. The main aim of that study was to assess hemodynamic effects of ISDN, in pts with MS, with special emphasis on PV com changes. PV comp was estimated according to Hirakawa equation (dV/dp = 0.4*k2*SV/(v-d) in 35 pts with MS, during preoperative right heart catheterisation with VYGON 5155-180 thermodilution catheters during rest and effort in supine position (25W). The same protocol was performed after Iso-Mack sprawy 3.75 mg. According to the PV comp response to ISDN, pts were divided in two groups: good responders (I)-15% and higher increase in PV comp and poor responders (II). ISDN increased PV comp in the whole group according to the response to ISDN, there were significant differences in stroke volume index (SVI) and heart rate (HR). In the group of good responders mean right atrial pressure (RA), mean pulmonary artery pressure (PAP), mean pulmonary wedge pressure (PWP) decreased significantly with simultaneous slight not significant decrease in SVI and not significant increase of HR. In the group of poor responders SVI decreased significantly by about 20% with significant increase of HR. In conclusion significant decrease in pulmonary pressures (PAP, PWP) in pts with good response to ISDN are secondary to the increase of PV comp, while among poor responders the same effects are due to diminished flow secondary to the decrease of the systemic venous return.     

Prediction of the Mechanical Properties of P91 Steel by Means of Magneto-acoustic Emission and Acoustic Birefringence

The paper describes an application of non-destructive volumetric magnetic and ultrasonic techniques for evaluation of the selected mechanical parameter variations of P91 steel having direct influence on its suitability for further use in critical components used in power plants. Two different types of deformation processes were carried out. First, a series of the P91 steel specimens was subjected to creep and second, one to plastic deformation in order to achieve the material with an increasing strain level up to 10%. Subsequently, non-destructive and destructive tests were performed. Magnetic methods based on measurements of magnetoacoustic emission and magnetic hysteresis loop changes as well as the ultrasonic method based on acoustic birefringence measurements, were applied. Finally, the static tensile tests were carried out in order to evaluate the mechanical parameters. It is shown that some relationships between the selected parameters coming from the non-destructive and destructive tests may be formulated.     

Polymer Microtips Fabricated at the Extremity of Photonic Crystal Fibers

In this paper, a simple method of manufacturing micrometer-sized polymer elements （microtips） at the extremities of the photonic crystal fibers （PCFs）, which are replacing standard optical fibers in many applications due to their unique properties, is presented. The method of microtips fabrication is based on the phenomena of photopolymerization, which is successfully used by the first time, to be best of our knowledge, to manufacture microtip at PCF. The three component photopolymerizable formulation consists of photo-initiating system and multifunctional triacrylate. The photopolymerization is carried out by green laser with the microtip growth controlled by the light exposure parameters （i.e. power and time）. Results of mic：rotip fabrication on standard fiber （SMF-28e＋） and large mode area PCF （LMA-10） are provided. Theinfluence of the initial process parameters on the final microtip characteristics （i.e., length, diameter and profile） is discussed. The potential applications of such polymer microtips are near-field scanning optical microscopy, coupling light sources with fibers and sensing.     

Radioluminescence and photoluminescence of hafnia-based Eu-doped phosphors

Crystal structures of hafnia are discussed and it is shown that addition of about 7 at.% of Lu to the HfO₂ host lattice enforces the mixed composition to crystallize in cubic structure even at room temperature. Without Lu HfO₂ crystallizes in monoclinic structure. Luminescence and luminescence excitation spectra of Hf_0.93Lu_0.07O_1.965 are presented and discussed for powders prepared at different temperatures (600–1000 °C) and with different content of Eu. It is shown that decay of the 595.4 nm luminescence is longer (2.5 ms) than the 610 nm (1.6 ms). Radioluminescence efficiency of the cubic Hf_0.93Lu_0.07O_1.965 is low and does not exceed 10% of the commercial Gd₂O₂S:Eu.     

A quaterthiophene-based rotaxane: synthesis, spectroscopy, and self-assembly at surfaces

Threaded molecular wires are shown to feature tunable properties. A new rotaxane based on a quaterthiophene threaded through a single β-cyclodextrin exhibits delocalization of the aromatic system that is also extended onto the central phenyl rings of the m-terphenylene end-groups. The rotaxane can undergo self-assembly that is better than the analogous bithiophene derivative, due to the increased π-π interactions.     

Radiation sterilized bone response to dynamic loading

Allogeneic bone grafts are used on a large scale in surgeries. To avoid the risk of infectious diseases, allografts should be radiation-sterilized. So far, no international consensus has been achieved regarding the optimal radiation dose. Many authors suggest that bone sterilization deteriorates bone mechanical properties. However, no data on the influence of ionizing radiation on bone dynamic mechanical properties are available. Bovine femurs from 2-year old animal were machine cut and irradiated with the doses 10, 15, 25, 35, 45 and 50 kGy. Dynamic mechanical analysis was performed at 1–10 Hz at the temperature range of 0–350 °C in 3-point bending configuration. No statistically significant differences in storage modulus were observed. However, there were significant decreased values of loss modulus between the samples irradiated with doses of 10 (↓14.3%), 15, 45 and 50 kGy (↓33.2%) and controls. It was stated that increased irradiation dose decreases the temperature where collagen denaturation process starts and increases the temperature where the collagen denaturation process finishes. It was shown that activation energy of denaturation process is significantly higher for the samples irradiated with the dose of 50 kGy (615 kJ/mol) in comparison with control samples and irradiation with other doses (100–135 kJ/mol).     

Algorithm for automated analysis of surface vibrations using time-averaged digital speckle pattern interferometry

A fully automated algorithm was developed for the recording and analysis of vibrating objects with the help of digital speckle pattern interferometry utilizing continuous-wave laser light. A series of measurements were performed with increasing force inducing vibration to allow the spatial distribution of vibration amplitude to be reconstructed on the object's surface. The developed algorithm uses Hilbert transformation for an independent, quantitative evaluation of the Bessel function at every point of the investigated surface. The procedure does not require phase modulation, and thus can be implemented within any, even the simplest, DSPI apparatus. The proposed deformation analysis is fast and computationally inexpensive.     

The phase stability of solid LiAlO2 used for the electrolyte matrix of molten carbonate fuel cells

LiAlO₂ is used as a solid matrix for molten carbonate fuel cell (MCFC) electrolyte tiles. These devices operate within the temperature range of 870–970 K. The -crystallographic form of this compound is commonly used for fabrication of these matrix tiles. The thermodynamic stability of this phase within the above temperature range is not clear and it is reasonable to consider the transformation to take place in solid LiAlO₂ in presence of molten alkali carbonates. In order to establish the crystallographic form of the compound that forms as a product of reaction between the liquid Li₂CO₃ and solid Al₂O₃, the kinetics of LiAlO₂ formation has been investigated. Values of conversion factor as a function of the reaction time have been determined both for a stoichiometric reaction mixture and for mixtures with an excess of the liquid 0.53 Li₂CO₃ + 0.47 Na₂CO₃ eutectic. The simultaneous determination of the reaction conversion factor and the relative intensity of the characteristic x-ray peak for the – LiAlO₂ form in the reaction mixture have shown that, within 843–973 K, in experiments of ca 100–10 hours, respectively, only this phasev of LiAlO₂ is formed. These results may explain the presence of some – LiAlO₂ amount in the MCFC electrolyte tiles after long run tests of these devices.     

Fuzzy histograms, weak fuzzification and accumulation of periodic quantities

The influence of the scale of a fuzzy membership function used to fuzzify a histogram is analysed. It is shown that for a class of fuzzifying functions it is possible to indicate the limit for fuzzification, at which the mode of the histogram equals the mean of the data accumulated in it. The fuzzification functions for which this appears are: the quadratic function for aperiodic histograms and the cosine square function for periodic ones. The scaled and clipped versions of these functions can be used to control the degree of fuzzification belonging to the interval [0,1]. While the quadratic function is related to the widely known Huber-type clipped mean or the kernel function derived from the Epanechnikov kernel, the clipped cosine square seems to be less known. The indications for using strong or weak fuzzification, according to the value of the fuzzification degree, are justified by examples in two applications: classic Hough transform-based image registration and novel accumulation-based line detection. Typically, the weak fuzzification is recommended. The images used are related to simulation images from teleradiotherapy and to mammographic images.     

Grinding of coal in the presence of vapours of organic compounds

The effect exerted by the sorption of vapour of several chemical compounds on the crushing of bituminous coal was investigated. Air-dry samples of a low-rank coal (82.7 wt%C) a coking coal (87.0 wt%C) and a high-rank coal (91.7 wt%C) were saturated with methanol, ammonia and benzene vapour for 100 h, crushed in a ball-mill, and subjected to sieve analysis. Sorption of methanol causes a marked increase of the crushability of all coals tested. Coal crushability increasing with increase of rank. The results have been interpreted according to the polymeric model of coal structure.