The Influence of the Addition of Microsilica and Fly Ash on the Properties of Ultra-High-Performance Concretes.

The paper presents experimental studies on the influence of a simultaneous, appropriately proportioned combination of microsilica and fly ash additives on the physical and mechanical properties of ultra-high-performance concretes (UHPCs). Concrete mixtures with the addition of microsilica in the amount of 6.7-14.

Effect of Doping Cement Mortar with Triclosan, Hypochlorous Acid, Silver Nanoparticles and Graphene Oxide on Its Mechanical and Biological Properties.

In order to improve the performance of cement mortar (Portland cement), it was enriched with triclosan, hypochlorous acid, silver nanoparticles and graphene oxide. Cement mortar is used, among other things, to fill the gaps between the tiles of building porcelain stoneware. A number of structural, mechanical and biological tests were carried out.

Experimental Calibration of a Homogeneous Substitute Material Model for Reinforced High-Performance Concrete Modeling.

The purpose of this work was to develop a substitute material model for the analysis of reinforced concrete structures. This paper presents proposals to solve the problem of limited calculation time, both to perform simulation models and to perform effective numerical or analytical analyses of structural elements in order to achieve results consistent with experimental results. Achieving this aim is conditional upon the determination of the material model parameters, taking into account the type of structure, the system of reinforcement, and the static strength-deformation parameters of the component materials.

Effect of Aggregate Type on Properties of Ultra-High-Strength Concrete.

In this work, we present an analysis of natural fine aggregates' influence on the properties of ultra-high-strength concrete. The reference concrete mix was made of natural sand with the addition of fly ash and microsilica. It was assumed to obtain concrete with a very high strength without the addition of fibers and without special curing conditions, ensuring the required workability of the concrete mix corresponding to the consistency of class S3.

Modified Formula for Designing Ultra-High-Performance Concrete with Experimental Verification.

The main purpose of the study was to propose a modification of Larrard's formula for both the design and compressive-strength evaluation of ultra-high-performance concrete. The proposed modification consisted of the introduction of new parameters into the original formula that allowed it to consider the amount of binders and fine-grained aggregates, the amount of reinforcing fibers, the specimen shape and size, the curing time, and a reinterpretation of the water/cement ratio. The proposed modification was verified based on comparative analysis with the results of our own experimental studies and results taken from the literature.

[Adipose tissue distribution in children with excessive body weight and the possibility of development of complications of obesity. II. Positive family history in relation to arteriosclerosis risk factor and the constitutional type of obesity in children].

98 children with simple obesity were investigated. The prevalence of cardiovascular diseases (hypertension, coronary heart disease including heart infarction, disturbances of the cerebral circulation) and diabetes in parents and relatives of the obese children have been evaluated. The relation between the type of obesity (androidal, gynoidal) and the prevalence of the above complications in the family history was assessed.

[Adipose tissue distribution in children with excess body weight and possible complications of obesity. I. Evaluation of an index (waist to hip circumference) in children with simple obesity].

Distribution of the fat tissue has been estimated in 94 children with simple obesity and in 100 children with normal parameters of the somatic development. The relation of waist measurement (at the navel level) to the hip measurement (at the level of sacral bone) (p/b) was evaluated. This ratio was higher in the group of the obese than in the normotensive children.

A trial of evaluating static and dynamic loads in man by means of analysis of the variability of instantaneous heart rate.

The instantaneous heart rate changes were examined in 12 forest workers during following tests: increasing (up to refusal) dynamic load on ergometer, rest in erect position, static load (about 75% of body weight) in erect position. The ECG signal, carrying information on heart rate, was amplified and processed by means of an especially designed heart rate analyzer. The dynamics of heart rate changes was evaluated through the analysis of differences of subsequent instantaneous heart rates and of distributions of heart rate accelerations and decelerations during the tests.