Characteristics of centrifugally cast GX25CrNiSi18-9 steel

The paper presents the results of microstructural examinations of the industrial heat-resistant centrifugally cast GX25CrNiSi18-9 steel characterised by increased content of Cu. The study included changes in the microstructure of base cast steel respective of the steel held at a temperature of 900 and 950°C for 48 hours. Based on the results obtained, an increase in microhardness of the examined cast steel matrix with increasing temperature was stated, which was probably caused by fine precipitates enriched in Cr, Mo, and C forming inside the matrix grains.The layer of scale formed on the tested cast steel oxidised in the atmosphere of air at 900 and 950°C was characterised by an increased tendency to degradation with increasing temperature of the conducted tests

Nanoscale imaging reveals laterally expanding antimicrobial pores in lipid bilayers

Antimicrobial peptides are postulated to disrupt microbial phospholipid membranes. The prevailing molecular model is based on the formation of stable or transient pores although the direct observation of the fundamental processes is lacking. By combining rational peptide design with topographical (atomic force microscopy) and chemical (nanoscale secondary ion mass spectrometry) imaging on the same samples, we show that pores formed by antimicrobial peptides in supported lipid bilayers are not necessarily limited to a particular diameter, nor they are transient, but can expand laterally at the nano-to-micrometer scale to the point of complete membrane disintegration. The results offer a mechanistic basis for membrane poration as a generic physicochemical process of cooperative and continuous peptide recruitment in the available phospholipid matrix

Vermiculite bio-barriers for Cu and Zn remediation: an eco-friendly approach for freshwater and sediments protection

The increase in heavy metal contamination in freshwater systems causes serious environmental problems in most industrialized countries, and the effort to find ecofriendly techniques for reducing water and sediment contamination is fundamental for environmental protection. Permeable barriers made of natural clays can be used as low-cost and eco-friendly materials for adsorbing heavy metals from water solution and thus reducing the sediment contamination. This study discusses the application of permeable barriers made of vermiculite clay for heavy metals remediation at the interface between water and sediments and investigates the possibility to increase their efficiency by loading the vermiculite surface with a microbial biofilm of Pseudomonas putida, which is well known to be a heavy metal accumulator. Some batch assays were performed to verify the uptake capacity of two systems and their adsorption kinetics, and the results indicated that the vermiculite bio-barrier system had a higher removal capacity than the vermiculite barrier (?34.4 and 22.8 % for Cu and Zn, respectively). Moreover, the presence of P. putida biofilm strongly contributed to fasten the kinetics of metals adsorption onto vermiculite sheets. In open-system conditions, the presence of a vermiculite barrier at the interface between water and sediment could reduce the sediment contamination up to 20 and 23 % for Cu and Zn, respectively, highlighting the efficiency of these eco-friendly materials for environmental applications. Nevertheless, the contribution of microbial biofilm in open-system setup should be optimized, and some important considerations about biofilm attachment in a continuous-flow system have been discussed.This work has been produced thanks to the collaboration of Dip.SA (University of Bologna) and IBB (University of Minho). A particular acknowledgment is due to Dr. E. Rosales. The work was partially financed by the FCT Strategic Project Pest-OE/EQB/LA0023 and the Project ‘‘BioEnv—Biotechnology and Bioengineering for a sustainable world,’’ co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER

Decisions-making skills as the main competences in work of managerial personnel at the local government administration offices

W niniejszym artykule zostały opisane kluczowe kompetencje i umiejętności potrzebne kierownikom jednostek samorządowych w wykonywaniu ich ról menadżerskich i funkcji zarządzania. Szczególny nacisk położono na umiejętności decyzyjne, czyli te kompetencje, które umożliwiają kierownikom podejmowanie właściwych decyzji. W część badawczej postawiono pytania: Jakimi kompetencjami powinni charakteryzować się kierownicy administracji samorządowej? Czy decyzje kierownika administracji samorządowej wymagają posiadania innych, specyficznych kompetencji niż w przypadku tzw. klasycznego menedżera organizacji biznesowej? W celu odpowiedzi na tak postawione pytania posłużono się wynikami badań własnych przeprowadzonych na grupie 208 kierowników z 75 różnych urzędów administracji samorządowej województwa śląskiego.The article presents managerial competencies’ issues in the decision-making aspect. We have claimed that there is a need for employing a new managerial (and not only administrative or political) paradigm in managing local government administration institutions. In the study part we have posed the following questions: What competencies should the managers in local government administration have to make appropriate decisions? Do decisions of the manager of the council administration require the possession of different, specific competences than in case of the manager of the business organization? The studies have been based on surveys of 208 managers from the 75 local government administrations from Upper Silesia region

Wyznaczanie właściwości pianotwórczych środków gaśniczych w aspekcie wykorzystania ich w akcjach ratowniczo-gaśniczych oraz w gaśnicach przenośnych i przewoźnych

W artykule przedstawiono wybrane metody badawcze pianotwórczych środków gaśniczych, jak również omówiono zastosowanie uzyskanych wyników badań w praktyce.In the article were presented research methods of fire extinguishing foams, as well as obtained results in practice applications were discussed

Trwałość środków gaśniczych

Omówiono zmiany właściwości środków gaśniczych w czasie przechowywania oraz wpływ warunków składowania na trwałość tych produktów.It discussed changes of specificity of extinguishing media in storage time and influence of storage condition on constancy these products

Barriers and decision-making conditions of managerial personnel at the local government administration offices

W artykule omówiono bariery i uwarunkowania podejmowania decyzji przez kadrę kierowniczą w urzędach administracji samorządowej. W artykule postawiono tezę zgodnie, z którą występują różnice, co do warunków i barier podejmowania decyzji przez kadrę kierowniczą w urzędach administracji samorządowej. W celu weryfikacji tak postawionej tezy posłużono się wynikami badań ankietowych przeprowadzonych w urzędach administracji samorządowej województwa śląskiego na grupie 208 kierowników.The article presents the barriers and decision-making conditions of managerial personnel at the local government administration offices. The studies have been based on surveys of 208 managers from the 75 local government administration from Upper Silesia region. The whole article ends in conclusion