Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
44 result(s) for "Ducki, J."
Sort by:
Working Together and Being Physically Active Are Not Enough to Advise Uniformly and Adequately Low Back Pain Patients: A Cross-Sectional Study
The profession of the health-care providers (HCPs) influences their recommendations to the patients. Conversely, interdisciplinarity seeks to challenge such differences, so that the patient receives one single and consistent therapeutic message. Some studies also suggest associations between HCPs life habits and recommendations. Our hypotheses were (1) that despite interdisciplinary work, the profession remains a predictor of recommendations and (2) that HCPs who are more physically active recommend more activity. Three clinical vignettes were presented to a group of experts of low back pain (LBP) (guidelines), and 20 physicians, 22 physiotherapists, and 23 nurses to assess how they evaluate the symptoms and pathologies of LBP patients and how much work and physical activity they recommend. Physical activity was assessed with accelerometers and questionnaires. Some interprofessional differences remained present within an interdisciplinary team. The nurses were more restrictive and further away from the guidelines. The physicians were the most in line with them. The physiotherapists recommend as much physical activity, but less work activity than the physicians. The level of physical activity of the HCPs is not associated with their recommendations. To ensure a clear and unique message, educational actions may be undertaken to promote the biopsychosocial model and clarify the guidelines.
The characteristic of deformability and quantitative description of the microstructure of hot-deformed Ni-Fe superalloy
The paper presents the results of research concerning the influence of hot plastic working parameters on the deformability and microstructure of a Ni-Fe superalloy. The research was performed on a torsion plastometer in the range of temperatures of 900-1150°C, at a strain rates 0.1 and 1.0 s . Plastic properties of the alloy were characterized by the worked out flow curves and the temperature relationships of flow stress and strain limit. The structural inspections were performed on microsections taken from plastometric samples after so-called “freezing”. The stereological parameters as the recrystallized grain size, inhomogenity and grain shape have been determined. Functional relations between the Zener-Hollomon parameter and the maximum yield stress and the average grain area have been developed and the activation energy for hot working has been estimated.
Effect of Heat Treatment on the Microstructure and Mechanical Properties of Sintered Stainless Tool Steel
In the paper, the new highly alloyed Cr-V-Mo stainless tool steel produced via the powder metallurgy method was examined. The Elmax steel is a new-generation sintered tool steel characterised by high resistance to wear and corrosion and very good dimensional stability. The purpose of the paper was to analyse the influence of the rate of cooling from the temperature of austenitization and of an additional sub-zero treatment on the microstructure, phase composition and the curve of mechanical properties of steel during tempering. It has been found that a sub-zero treatment decreased the retained austenite fraction in the steel structure after hardening in oil or compressed air. The use of a sub-zero treatment on specimens after hardening had no significant effect on steel hardness after tempering, but it negatively affected the course of bending strength and impact strength of steel. Based on the obtained results it has been found that optimum mechanical properties for the Elmax steel were obtained after hardening from a temperature of 1080°C in compressed air (without a sub-zero treatment) and tempering at a temperature of 180°C.
The hot-deformability and quantitative description of the microstructure of hot-deformed Fe–Ni superalloy
The paper presents the results of research concerning the influence of hot plastic forming parameters on the deformability and structure of a Fe-Ni austenitic alloy. The research was performed on a torsion plastometer in the range of temperatures of 900-1150 °C, at a strain rate 0.1 and 1.0 s-1. Plastic properties of the alloy were characterized by the worked out flow curves and the temperature relationships of flow stress and strain limit. The structural inspections were performed on microsections taken from plastometric samples after so called \"freezing\". The stereological parameters as the recrystallized grain size, inhomogenity and grain shape have been determined. Functional relations between the Zener-Hollomon parameter and the peak stress and the mean grain size have been developed and the activation energy of the hot plastic deformation has been estimated. The examination of substructure on TEM allowed the calculation of structural parameters: the average subgrain area and the mean dislocation density. A detailed investigation has shown that the substructure is inhomogeneous, consists of dense dislocation walls, subgrains and recrystallized regions.
The Deformability of Fe-Ni Superalloy during High Temperature Deformation
The influence of initial soaking and parameters of plastic deformation on the deformability of A-286 superalloy have been presented. The hot-torsion tests were executed at constant strain rates of 0.1 and 1.0 s-1, at testing temperatures in the range 900-1150°C and were conducted until total fracture of the samples. Plastic properties of the alloy were characterized by worked out flow curves and the temperature relationships of flow stresses and strain limits. Activation energy for hot working Q was assessed for the alloy after two variants of previous heating, i.e. 1100°C/2 h and 1150°C/2 h.
Precipitation and Growth of Intermatallic Phases in an Fe-Ni Superalloy during Prolonged Ageing
The influence of prolonged aging on the precipitation process of intermetallic phases, as well as carbide and boride in an Fe-Ni superalloy has been studied. The samples were subjected to a solution heat treatment at 980°C for 2 h and water quenched, and then aged at 715, 750 and 780°C for 0.5-500 h. The samples were analysed using transmission electron microscopy (TEM) and X-ray diffraction. Direct measurements on the electron micrographs allowed to calculate the mean diameter () of the γ’ phase. The growth step of the γ’ phase particles has been analysed on the basis of the LSW theory, as well as the activation energy of the γ’ phase coagulation has been estimated.
Research of the microstructure and precipitation strengthening in a high-temperature Fe–Ni superalloy
The paper describes the relationships between the kinetics of precipitation and growth of the intermetallic phase γ′ - Ni3(Al,Ti) and the strengthening magnitude obtained in a high-temperature Fe–Ni superalloy of the A-286 type. In order to accomplish the goal of the study, the author used the LSW coagulation theory and Brown and Ham's conventional analysis of strengthening by ordered particles. The samples were subjected to a solution heat treatment at 980°C/2h/water and then aged at 715, 750 and 780°C, with holding times 0.5-500 h. The heat-treated samples were subjected to structural analyses (TEM, X-ray diffraction) and analyses of mechanical properties (hardness test, static tensile test). Direct measurements on the electron micrographs allowed to calculate the structural parameters of the γ′ phase, i.e. mean diameter, volume fraction and mean distance between particles. In accordance with the LSW theory, linear dependencies of changes in mean diameter as a function of ageing time (t1/3) were elaborated and the activation energy (E) of the γ′ phase coagulation process was determined. The author carried out analyses of strengthening and flow stress (Δτ0) increases as a function of the particle size of the γ′ phase and determined the value of the antiphase boundary energy (yapb) for the analyzed Fe–Ni alloy. It was found that the value of APB energy of phase γ′ depended significantly on the alloy ageing temperature. Such a dependence of the quantity yapb on the ageing temperature for the investigated alloy was explained by an increase in the degree of internal arrangement of phase γ′ and by increasing sizes of ordered domains as a result of coalescence.
Fatigue Behaviour of Carbide Precipitation Hardened Austenitic Steels
The paper presents the results of investigations of the microstructure and fatigue behaviour of two newly invented Cr-Ni and Cr-Ni-Mn austenitic steels of 13/13 and 12/8/8 type strengthened through carbide particle precipitation. The specimens of the investigated steels were subjected to tests after heat treatment, i.e. solution heat treatment (1200°C/0.5 h/water) and aged at a temperature of 700°C for 12 h, with cooling in air. The heat treated specimens were then subjected to low-cycle fatigue tests (LCF), carried out at room temperature and at an increased temperature of 600°C. Diagrams of fatigue characteristics of the investigated steels at room temperature as well as at elevated temperature have been worked up. It has been found that during low-cycle fatigue tests, at both temperatures, the investigated austenitic steels indicated a fatigue softening effect. The results of LCF at room temperature showed that the fatigue durability (Nt) of both austenitic steels is located in the range 0.8÷1.3×103 cycles. The results of low-cycle fatigue tests at an increased temperature 600°C indicated that the fatigue durability of the investigated steel was lower, and is located in the range Nt = 0.5÷0.6×103 cycles. It has been pointed out that the investigated austenitic steels are characterized by a stability of structure in conditions of cyclic fatigue.
Who's right on pollution levels?
Since Jan. 1, I have kept a record of the Pollution Standard Index published daily in The Courant. The pollution index is as follows: 0-50, good; 50-100, moderate; 100-200, unhealthful; 200-300, very unhealthful; 300-400, hazardous.
Who's right on pollution levels?
Since Jan. 1, I have kept a record of the Pollution Standard Index published daily in The Courant. The pollution index is as follows: 0-50, good; 50-100, moderate; 100-200, unhealthful; 200-300, very unhealthful; 300-400, hazardous.