Primary crystal orientation of the thin-walled area of single-crystalline turbine blade airfoils

The thin-walled airfoil areas of as-cast single-crystalline turbine blades made of CMSX-4 superalloy were studied. The blades were produced by the industrial Bridgman technique at withdrawal rates of 2, 3 and 4 mm/min. The angle between the [001] crystallographic direction and blade axis, related to the primary orientation, was defined by the Ω-scan X-ray diffraction method at points on the camber line located near the tip of an airfoil and at points of a line located in parallel and near the trailing edge. Additionally, primary crystal orientation was determined by Laue diffraction at the selected points of an airfoil. The influence of mould wall inclination on the primary crystal orientation of the thin-walled areas is discussed. The effect of change in the [001] crystallographic direction, named as "force directing", was considered with regard to the arrangement of primary dendrite arms in relation to the trailing edge and the camber line. It was stated that when the distance between the mould walls is less than the critical value of about 1.5 mm the "force directing" increases as the distance between the walls of the mould decreases. The effect may be controlled by selecting an appropriate secondary orientation using a seed crystal in the blade production process. The model of dendrite interaction with the mould walls, including bending and "deflection", was proposed

New perspectives in the treatment of hard-to-heal wounds

Hard-to-heal wounds continue to be a challenge in the everyday surgical practice. Their treatment is time-consuming, expensive and in many cases requires interdisciplinary assessment. Therapy option include properly selected surgical procedures and dressings combined with systemic antibiotherapy. Application of  vacuum assisted closure (VAC) facilitates the evacuation of pathological discharge, reduces tissue oedema and eliminates bacterial biofilm. Complementary administration of antibiotics to control chronic infection relies today in most cases on vancomycin, ciprofloxacin or piperacillin with tazobactam, with good clinical effect. An alternative to antibiotics against MRSA, administered at hospitals might be dalbavancin, a new generation lipoglycopeptide, which belongs to the same class as vancomycin. Introduction of dalbavancin and VAC might be an alternative to traditional methods of therapy

Defect Creation in the Root of Single-Crystalline Turbine Blades Made of Ni-Based Superalloy

An analysis of the defects in the vicinity of the selector–root connection plane occurring during the creation of single-crystalline turbine blades made of CMSX-6 Ni-based superalloy was performed. X-ray diffraction topography, scanning electron microscopy, and positron annihilation lifetime spectroscopy were used. Comparing the area of undisturbed axial growth of dendrites to the area of lateral growth concluded that the low-angle boundaries-like (LAB-like) defects were created in the root as a result of unsteady-state lateral growth of some secondary dendrite arms in layers of the root located directly at the selector–root connection plane. Additional macroscopic low-angle boundaries (LABs) with higher misorientation angles were created as a result of concave curvatures of liquidus isotherm in platform-like regions near selector–root connections. Two kinds of vacancy-type defects, mono-vacancies and vacancy clusters, were determined in relation to the LABs and LAB-like defects. Only mono-vacancies appeared in the areas of undisturbed axial growth. Reasons for the creation of macroscopic LABs and LAB-like defects, and their relationships with vacancy-type defects were discussed

Variation of crystal orientation and dendrite array generated in the root of SX turbine blades

The variation of the crystal orientation and the dendrite array generated in the root of the single-crystalline (SX) turbine blades made of CMSX-4 superalloy were studied. The blades with an axial orientation of the [001] type were solidified by the industrial Bridgman technique using a spiral selector at a withdrawal rate of 3 mm/min. The analysis of the crystal orientation and dendrite arrangement was carried out using scanning electron microscopy, X-ray di raction topography, and Laue di raction. It was found that the lateral growth of such secondary dendrite arms, which are defined as “leading” and grow in the root at first, is related to the rotation of their crystal lattice, which is the reason for creation of the low-angle boundary (LAB) type defects. The primary crystal orientation of the selector extension (SE) area determines the areas and directions of the lateral growth of the leading arms. Additionally, it was found that in the SE areas of the root, near the connection with the selector, the spatial distribution of the [001] 0 crystallographic direction has a complex wave-like character and may be related to the shape of the crystallization front

Measurement of thermal transmittance of multi-layer glazing with ultrathin internal glass partitions

Currently, the most technologically advanced building walls have an overall heat transfer coefficient U at a level of 0.10 W/(m2K) which corresponds to the passive house standard. Less demanding requirements are set for building windows for which the thermal performance has not yet been significantly improved. Therefore, there is a demand for developing new technologies for glazing with superior thermal performance, good optical quality and of the lowest possible weight. In the paper, measurements of thermal performance of multi-layer glazing with ultrathin internal glass partitions are presented

Plasma Interleukin-18 and Dendritic Cells in Males with Psoriasis Vulgaris

Peripheral blood dendritic cells seem to play a crucial role in psoriatic inflammatory processes. The aim of our study is to investigate the relationship between plasma interleukin-18 (IL-18) levels and blood dendritic cells in psoriatic patients. IL-18 plasma levels were measured by ELISA. Phenotypes of dendritic cell subsets were analyzed by double-colour flow cytometry. Plasma IL-18 level in psoriatic males was significantly higher, whereas counts of BDCA-2+ cells were lower than in the control group. The myeloid/plasmacytoid ratio was significantly higher in the patient group compared to the control one. In the patient group, significant negative correlations between plasma IL-18 level and both the BDCA-1+ and BDCA-2+ counts were found. BDCA-1+ counts correlated negatively with percentage of skin involvement. IL-18 seems to play a role in psoriasis pathogenesis. The decreased counts of blood plasmacytoid DCs in psoriatic patients might result from IL-18 down-regulation of plasmacytoid DC precursor proliferation

Heterogeneity of the dendrite array created in the root of cored SX turbine blades during initial stage of crystallization

The roots of cored single-crystalline turbine blades made of a nickel-based CMSX-4 superalloy were studied. The casts were solidified by the vertical Bridgman method in an industrial ALD furnace using the spiral selector and selector continuer situated asymmetrically in the blade root transverse section. Scanning electron microscopy, the Laue diffraction and X-ray diffraction topography were used to visualize the dendrite array and the local crystal misorientation of the roots. It has been stated that heterogeneity of the dendrite array and creation of low-angle boundaries (LABs) are mostly related to the lateral dendrite branching and rapid growth of the secondary and tertiary dendrites near the surface of the continuer–root connection. These processes have an unsteady character. Additionally, the influence of the mould walls on the dendrite array heterogeneity was studied. The processes of the lateral growth of the secondary dendrites and competitive longitudinal growth of the tertiary dendrites are discussed and a method of reducing the heterogeneity of the root dendrite array is proposed

The CHOICE study (Contraceptive Health Research Of Informed Choice Experience) – an educational research program for Polish women planning combined hormonal contraceptives use

Objectives: The aim of the study was to develop an optimal educational model for contraceptive counseling, to analyze conditions influencing choice of hormonal contraception, to study patients’ opinions on present, planned and proposed contraceptive methods and to link these data with socioeconomic and demographic conditions. Materials and methods: One thousand eight hundred fifty women (mean age 26.8±5.9 yrs) willing to use hormonal contraception were presented with essential information on combined hormonal contraception and asked to fill the anonymous questionnaire investigating factors influencing contraceptive choice and patients’ opinion on alternative forms of birth regulation. The study was conducted in selected 185 centers in Poland and was a part of a larger survey (CHOICE) conducted on 11 216 women in Europe and Israel. Results: Majority of the studied women were in stable relationship (85,5%), had higher or incomplete higher education (54.8%) and permanent job (54%). The purpose of the visit was to start/change contraception (64.2%), a routine gynecologic check-up (36.7%) or the need for a prescription for the continued contraceptive medication (18.7%). The most commonly used contraceptive methods were oral contraceptive pills (OCP, 38.7%) and condom (24.9%). Majority of women highly valued contraceptive counseling and more than 90% were eager to get familiarized with information leaflets. Before the counseling majority of subjects stated that were convinced to use OCP (52.7%; major advantages named: easy to use, favorable bleeding profile, amelioration of menstrual discomfort, comfortable, discrete) and contraceptive patch (22%; major advantages named: applied once a week, comfortable, simple, low risk for noncompliance, favorable bleeding profile). After the counseling there was an increase in proportion of women interested in contraceptive hormonal ring (by 19%; major advantages named: applied once a month, comfortable, very low risk for noncompliance, high efficacy and positive recommendation from a physician). In 58 women no hormonal contraception was recommended, predominantly due to medical contraindications. Conclusions: Appropriate patient counseling on all forms of combined hormonal contraception, with special attention paid to benefits and safety issues, suited to women’s expectations and education is fundamental for the selection of an optimal birth control method