Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 5

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Ziola w doniczkach przedluzeniem lata

100%

Reszka M.

nr 11

27-28

Sposoby zabezpieczania transakcji handlowych w zakresie wykonawstwa hal

100%

Reszka M.

2016

tom Nr 2

82--84

Samo zawarcie nawet najbardziej korzystnej finansowo umowy to jedynie połowa sukcesu. Istotne jest uzyskanie towarzyszącego przedmiotowej umowie zabezpieczenia, by po ukończeniu realizacji umowy uzyskać należną zapłatę i nie tracić czasu oraz pieniędzy w sądach, bez gwarancji faktycznej windykacji naszej należności, nawet w przypadku wygrania sporu.

Swieta w rodzinie

100%

Reszka M.

nr 12

Analysis of the impact of high temperature on the change in tensile strength of cement mortars with or without polypropylene fibres added

63%

Drzymala T. , Reszka M.

Scientific Journal of the Military University of Land Forces

2018

tom Vol. 50, No. 3(189)

109--126

When evaluating concrete, its strength is the most important feature from the practical point of view. In compliance with technological requirements, the strength of concrete depends primarily on its composition, mainly on the content and strength of cement slurry. This is because this concrete component is most susceptible to changes in working conditions in a construction, including high temperature impact on concrete during the fire. The paper presents the results of tests performed on the cement mortar with and without the addition of polypropylene fibers. This treatment allowed for the elimination of the effect of the coarse aggregate by reason of the accuracy of the tested strength characteristics. The studies concerned the impact of high temperature on the change in tensile strength of cement mortars modified with the addition of polypropylene fibers. The analysis of available literature shows that one of the main causes of concrete’s thermal spalling is seen in high tensile stresses. The results of many tests prove that the addition of polypropylene fibers can have a positive effect on the behavior of concrete structures at high temperatures and help reduce spalling. The polypropylene fibers present in a composite may also positively influence the increase in tensile strength. This article discusses the purpose and scope of research, research methods, the experiment plan, test benches, and test results as well. The conclusions of the study were formulated in the final part of the article.

Mechanism of Adsorption of Selected Monovalent and Divalent Inorganic Ions at the Alumina/Electrolyte Interface

45%

Jabłoński J. , Janusz W. , Reszka M. , Sprycha R. , Szczypa J.

2000

tom Vol. 74, nr 10

1399-1409

The mechanism of adsorption of selected mono- and divalent ions (Na+, Ca2+, Cl–, SO4 2- ) at the metal oxide (Al2O3)/electrolyte interface has been studied using different experimental techniques: potentiometric titration, zeta potential and adsorption density measurements. Radiotracers and ion-selective electrodes were used to measure the adsorption densities of ions. It was found that the accuracy of both methods was almost the same. Ion-selective electrodes allowed to acquire adsorption data for shorter times of contact between the oxide and electrolyte solution. Based on the potentiometric titration data, ionization and complexation constants of surface hydroxyl groups were calculated using the site binding theory of the electrical interfacial layer. The adsorption density of Ca2+, at the same pH and ion concentration, was significantly higher than that observed for sodium ions and revealed strong pH dependence (adsorption edge). A shift of the pzc and iep of alumina was observed in the systems containing chloride, sulphate or calcium ions, due to the specific adsorption of those ions at the oxide/electrolyte interface. The calculated pKA values for different anions showed that the stability of surface complexes increased in the following sequence: ClO4 < Cl– < SO4