Weldability of high strength steel in underwater environment

The article describes the problems with weldability of high-strength steels in the aquatic environment. The tendency of steel S355J2G3 and S500M to form cold cracks when welded in wet welding conditions has been experimentally evaluated. It was found that the tested steels have a high propensity to cracking. An experiment has been proposed and tested to evaluate the usefulness of the tempering bead technique as a method of improving the weldability of high-strength steels under water in wet welding conditions.     

Influence of Hydrostatic Pressure on Compressive Strength of Self-consolidating Concrete

The design of unique chamber, in which the SCUWC （self-consolidating underwater concrete） can be tested under the impact of the hydrostatic pressure from 0.1 MPa to 0.5 MPa, is presented in the paper. The results of the preliminary tests of the effect of the hydrostatic pressure on the compressive strength of SCUWC were shown. The impact of the hydrostatic pressure on the compressive strength values of test specimens has been confirmed. There has been an increase in the strength of the specimens taken from the upper parts of the concrete samples. As it can be seen from the preliminary research, the differences in compressive strength are related to the differences that occur in the size and distribution of air voids in the samples taken from upper and lower parts of the test specimens. On the basis of the carried out investigations of the compressive strength, it can be concluded that the hydrostatic pressure has a favorable effect on the compressive strength of the tested specimens of SCUWC. Increase of the compressive strength is observed mostly in the upper layers of the samples. Preliminary analysis of the quantity and distribution of air pores in the samples of concrete subjected to pressure 0.5 MPa confirms the positive impact of the hydrostatic pressure on the layers close to the surface indicated by the absence of large air voids above 1,500μm and by reducing the quantity of air pores of size above 300μm.     

The effect of feed supplementation with dietary sources of n‐3 polyunsaturated fatty acids,flaxseed and algae Schizochytrium sp., on their incorporation into lipid fractions of Japanese quail eggs

The influence of feed supplemented with dietary sources of n‐3 polyunsaturated fatty acids (PUFAs), namely flaxseed and algae Schizochytrium sp., on the fatty acid composition of lipids from Japanese quail eggs was studied. Two groups of quails were fed for 19 weeks, starting from 6th week of life. Lipid fractions from dried egg mass of total of 4300 eggs of control and experimental group were analysed. The fatty acid profile was affected in both triacylglycerols and phospholipids. The significant (P < 0.05) increase in n‐3 PUFAs up to 7.33% in the total lipids, α‐linolenic acid (ALA, 18:3) up to 4.57% in triacylglycerols, docosahexaenoic acid (22:6, DHA) up to 23.91% in phosphatidylethanolamine and up to 4.35% in phosphatidylcholine as well as the significant (P < 0.05) reduction in n‐6/n‐3 ratio in the lipid fractions to the range of 0.9–3.7 was observed in experimental group. The incorporation of different n‐3 into lipids was selective: ALA was found in the triacylglycerol fraction, whereas EPA, DPA and DHA were detected in the phospholipid fractions, exclusively at sn‐2 position. The studies showed that the feeding quails with modified diets is effective way of biofortifying the eggs with nutritionally desired n‐3 PUFAs.     

A method to detect the level and direction of mechanical forces with the aid of load-induced martensitic phase transformation

Information on the mechanical load which has been applied on a component during its lifecycle is becoming more and more interesting in order to assist the development of new generations of lightweight components. To collect this information from a large number of components in the field, cost-effective sensor techniques are required. The idea of the research presented in this paper is to qualify the base material of a component itself as a sensor. Load-induced changes in the microstructure of metastable austenitic sheet metals at the basis for this idea. Capabilities of increasing the sensitivity related to load-induced martensite phase transformations with the aid of metal forming operations as well as an approach to detect the direction of mechanical forces using embossed sensor fields are presented. The development of sensor fields based on FE-simulation as well as the results of experimental tests are discussed.     

Directional Multiscale Analysis and Optimization for Surface Textures

Surface texturing has a potential to become a cost effective and easy way to improve the tribological performance of lubricated interfacing surfaces. Effects of surface textures on the performance of machine elements as frictional pairs have been investigated over the past two decades. However, despite this research only a limited number of analytical solutions have been proposed as the majority of studies have been experimental and results obtained have not been optimal. This is because the commonly used surface characterization methods are not able to quantify surface textures over a range of scales at different directions and the optimization methods used work only for relatively simple textures and specific constraints imposed on pressure, film thickness, sliding velocity and lubricant rheology. Previous studies have addressed these issues, to some degree, by developing directional fractal signature methods and unified computational approach for texture optimization. In this article, recent advancements in the development of fractal methods and optimization of surface textures are presented.     

Polymers with Esters of Phosphoric Acid Units: From Synthesis,Models of Biopolymers to Polymer?Inorganic Hybrids

Syntheses, some properties, and applications of the poly(alkylene phosphate)s prepared either by ring-opening polymerization (ROP) or by polycondensation are described mostly on the basis of the data from our laboratories. The ROP of some cyclic phosphates and H-phosphonates are living and/or controlled process. Transesterification of the products of the reaction of an excess of dimethylphosphonate with glycols leads to polymers with M_n close to 5×10⁴. Poly(alkylene phosphate)s with five or six atoms in repeating units bear resemblance to the main chains of nucleic and teichoic acids. These and similar poly(alkylene phosphate)s with different repeating units were used as liquid membranes for the efficient separation of cations as well as to modify the medium for CaCO₃ crystallization. In this latter process, a diblock copolymer with ionic and nonionic block was used. Poly(alkylene phosphate)s constituted the ionic block and the nonionic block was formed from poly(ethylene glycol); together with CaCO₃ polymer inorganic hybrids were formed.     

Effect of randomly methylated beta-cyclodextrin on physical properties of soils

The application of cyclodextrins in several soil remediation technologies has been increasingly studied, but little is known about their effects on soil physical properties. One of the popular soil remediation additives, randomly methylated beta-cyclodextrin (RAMEB), was found to significantly alter surface and pore properties of soil clay minerals. Therefore, in this paper we studied the effect of various RAMEB doses on physical properties of selected soils, representing a wide range of clay content (3-49%). The results showed that soil physical properties were greatly modified by RAMEB treatment. Analysis of water vapor adsorption isotherms revealed that RAMEB increased water adsorption and surface area in sandy soils and decreased them in clayey soils. An increase in adsorption energy of water in RAMEB-treated soils indicated that desorption of nonpolar pollutants can be enhanced. Water vapor desorption isotherms showed that the volumes and radii of micropores (nanometers range) increased above 1% RAMEB concentration. The micropores became more rough and complex after RAMEB treatment as deduced from an increase in fractal dimensions. The volume of soil mesopores measured by mercury intrusion porosimetry (micrometers range) gradually decreased in most soils with an increase in RAMEB concentration whereas the average mesopore radius increased, indicating that finer mesopores were blocked by RAMEB. Measurements of the granulometric composition of soils by sedimentation analysis showed that the amount of coarse-size soil fractions increased on the expense of finer fractions due to aggregation of smaller particles. Behavior of the studied soils after RAMEB treatment depended on their clay content and the dose of cyclodextrin. In clay-rich soils, strong interactions of cyclodextrins with the soil solid phase governed the resulting soil properties. In clay-poor soils, the cyclodextrin excess (not interacted with clays) played a dominant role. Modification of surface, pore, and aggregation properties of soils by RAMEB can have a significant effect in soil remediation technologies.     

Geoenergy in Poland

This paper presents the current state of geothermal energy production in Poland and its future development prospects. At present, there are four geothermal heating plants in Poland. In addition, warm water is used in seven spa towns in balneology as well as in seven thermal swimming pools for recreational purposes. There has recently been an increase in the number of installed heat pumps in Poland – reaching 10,000 in 2010. In the near future the development of geothermics in Poland is forecast to continue. The first power and heat geothermal plant is being built in Uniejów whilst in more than ten other towns special swimming pool complexes using geothermal warm water are being built or designed. In the coming years heat pumps will be installed in living and office buildings as well as in public use buildings (mostly in newly built ones). Moreover, in Poland it is planned to use heat pumps in order to recover waste heat from factories and power plants.     

Biocompatible Materials in Otorhinolaryngology and Their Antibacterial Properties

For decades, biomaterials have been commonly used in medicine for the replacement of human body tissue, precise drug-delivery systems, or as parts of medical devices that are essential for some treatment methods. Due to rapid progress in the field of new materials, updates on the state of knowledge about biomaterials are frequently needed. This article describes the clinical application of different types of biomaterials in the field of otorhinolaryngology, i.e., head and neck surgery, focusing on their antimicrobial properties. The variety of their applications includes cochlear implants, middle ear prostheses, voice prostheses, materials for osteosynthesis, and nasal packing after nasal/paranasal sinuses surgery. Ceramics, such as as hydroxyapatite, zirconia, or metals and metal alloys, still have applications in the head and neck region. Tissue engineering scaffolds and drug-eluting materials, such as polymers and polymer-based composites, are becoming more common. The restoration of life tissue and the ability to prevent microbial colonization should be taken into consideration when designing the materials to be used for implant production. The authors of this paper have reviewed publications available in PubMed from the last five years about the recent progress in this topic but also establish the state of knowledge of the most common application of biomaterials over the last few decades.