Temperature Dependence of Fracture Characteristics of Variously Heat-Treated Grades of Ultra-High-Strength Steel: Experimental and Modelling.

The temperature dependence of tensile characteristics and fracture toughness of the standardly heat-treated low-alloyed steel OCHN3MFA along with three additionally heat-treated grades was experimentally studied. In the temperature range of ⟨-196; 22⟩ °C, all the additional heat treatments transferred the standard steel from a high- to ultra-high strength levels even with improved tensile ductility characteristics. This could be explained by a reduction of the inclusion content, refinement of the martensitic blocks, ductile retained austenite content, and homogenization of the shape ratio of martensitic laths as revealed by metallographic, X-ray, and EBSD techniques.

Increasing Fatigue Endurance of Hydroxyapatite and Rutile Plasma Sprayed Biocomponents by Controlling Deposition In-Flight Properties.

Three sets of hydroxyapatite and rutile-TiO coatings were plasma sprayed onto metallic substrates. The spray parameters of the sets were modified so as to obtain different in-flight temperatures and velocities of the powder particles within the plasma jet (ranging from 1778 to 2385 K and 128 to 199 m s, respectively). Fatigue endurance of the coated specimens was then tested.

Nitrogen Interstitial Alloying of CoCrFeMnNi High Entropy Alloy through Reactive Powder Milling.

The present work is focused on the synthesis of CoCrFeMnNi high entropy alloy (HEA) interstitially alloyed with nitrogen via powder metallurgy routes. Using a simple method, nitrogen was introduced to the HEA from the protective N gas atmosphere during mechanical alloying (MA) processing. The lattice parameter and amount of nitrogen in HEA were observed to be linearly proportional to the milling duration.

Sampling times influence the estimate of parameters in the Weibull dissolution model.

The aim is to determine how well the parameters of the Weibull model of dissolution can be estimated in dependency on the chosen times to measure the empirical data. The approach is based on the theory of Fisher information. We show that in order to obtain the best estimates the data should be collected at time instants when tablets actively dissolve or at their close proximity.

Diffusion approximation of neuronal models revisited.

Leaky integrate-and-fire neuronal models with reversal potentials have a number of different diffusion approximations, each depending on the form of the amplitudes of the postsynaptic potentials. Probability distributions of the first-passage times of the membrane potential in the original model and its diffusion approximations are numerically compared in order to find which of the approximations is the most suitable one. The properties of the random amplitudes of postsynaptic potentials are discussed.

On the estimate of the rate constant in the homogeneous dissolution model.

The aim is to determine how well the rate parameter of the homogeneous model of dissolution can be estimated in dependency on the chosen times to measure the empirical data. The approach is based on the theory of Fisher information. We show that if the probability distribution of the measurement errors is known, the data should be collected at a single time instant or its close proximity in order to obtain the best estimate.

Is carotid endarterectomy under the cervical plexus block safe for all patients with various degree of cardiovascular risk?

Background: The result of the GALA study did not answer the question whether it is safe to perform carotid endarterectomy (CEA) under the cervical plexus block (CPB) in patients at high cardiovascular (CV) risk. The aim of the study was to compare CV stability and the frequency of cardiovascular and neurological complications in 3 groups of patients with various degree of CV risk who underwent CEA under CPB.

Methods: 60 patients operated on in CPB were divided into the 3 groups according to the degree of their CV risk (I: very high, II: medium, III: low).

Homogeneous diffusion layer model of dissolution incorporating the initial transient phase.

Purpose of this paper is to describe characteristic features of dissolution data by using homogeneous model of dissolution with initial transient phase. To achieve the goal we consider a random lag time before the homogeneous phase of the dissolution begins. The resulting dissolution profiles are characterized by sigmoidal shape commonly observed in empirical dissolution data.

Random effects in drug dissolution.

The deterministic models of dissolution are commonly used in pharmaceutical studies, however, experimental results point to stochastic nature of the dissolution processes. In this paper we present stochastic modifications of deterministic models using the concept of Wiener process. The models are given in form of stochastic differential equations and their properties are studied.

The most frequent problems in the initial stage of burn management.

On the basis of three case reports discussed in the article, the authors demonstrate the most frequent serious drawbacks occurring in the initial stage of care of severely burned patients. The first case report highlights the importance of correct determination of the extent of the burn trauma, which should be correctly assessed by every first contact physician. The second case report demonstrates the need for adequate management of patients with severe burn trauma (especially airway management and i.

Quality of prehospital management of patients with burn injuries--a retrospective study.

The authors evaluate the quality of burn patient management prior to admission to a specialized department. The most frequent mistake was found to be inadequate airway management (no intubation) and a lack of an i.v.