Search

W pracy przedstawiono metodę wyznaczania skali podobieństwa modelowego – kU energii sprężystej przejętej przez sztuczne dno szybu. Stosując metodę analizy wymiarowej określono energię sprężystą w postaci funkcji wykładniczej, której argumentami są trzy bezwymiarowe liczby kryterialne. Wartość wykładnika potęgowego – z, charakteryzującego tą funkcję wyznaczono analizując wyniki obliczeń dla trzech modeli MES sztucznego dna szybu, różniących się między sobą cechami geometrycznymi. Wyznaczona zależność skali podobieństwa modelowego – kU od skal podobieństwa geometrycznego obiektu rzeczywistego i modelu umożliwi opracowanie kryteriów podobieństwa modelowego, charakteryzujących uderzenie spadającego ciała o sztuczne dno szybu.

In this study, new composite bisphosphonate delivery systems were obtained from polyurethanes (PUs) and nanocrystalline hydroxyapatite (HA). The biodegradable PUs were first synthesized from poly(ε-caprolactone) diols (PCL diols), poly(ethylene adipate) diol, 1,6-hexamethylene diisocyanate, 1,4-butanediol and HA. Moreover, the PCL diols were synthesized by the ring-opening polymerization catalysed by the lipase from Candida antarctica. Next, composite drug delivery systems for clodronate were prepared. The mechanical properties of the obtained biomaterials were determined. The cytotoxicity of the synthesized polymers was tested. The preliminary results show that the obtained composites are perspective biomaterials and they can be potentially applied in the technology of implantation drug delivery systems.

Due to its high total sulphur content and other unfavourable properties, pyrolytic oil obtained as a result of tyres pyrolysis is not suitable for use as motor or heating fuel. Therefore, pyrolytic oil was hydrorefined. Hydrorefined oil was used as a component of light heating oil. A composition was prepared from 30 wt % hydrorefinate with 70 wt % Ekoterm Plus (a commercial oil). Unfortunately, the flash point temperature of the hydrorefinate was too low, and did not allow fuel compliant with the Polish standard PN-C-96024:2011 for L1 light heating oil to be obtained. Therefore, the fraction with boiling point below 180 °C was removed from the hydrorefinate. The residue, with a flash point of 74 °C and a sulphur content of 0.143 wt %, was mixed with Ekoterm Plus and fuels with a hydrorefinate fraction content of 30 and 50 wt % were prepared. The composition containing 30 wt % met the requirements for L1 oil in the whole range of tested parameters. Total sulphur content was 0.092 wt %, specific weight was 856 kg/m3 and closed cup flash point was 64 °C. However, the composition containing 50 wt % hydrorefinate did not meet the requirements regarding sulphur content and specific weight. Sulphur content, specific gravity, and flash point are the parameters limiting the possibility of using hydrorefined pyrolytic oil for composing light heating oils compliant with the mentioned standard.

The past decade has seen growing interest in the investigation of peptides with antimicrobial activity (AMPs). One approach utilized in infection control is incorporation of antimicrobial agents conjugated with the polymers. This review presents the recent developments on polymeric AMP carriers and their potential applications in the biomedical and pharmaceutical fields.