Thermal utilisation of solar energy : Croatian National Energy Program SUNEN, 1998 – 2010

In the paper, thermal use of solar energy as well as prospects and problems of its utilisation in Croatia have been given. The National Solar Energy Program, SUNEN, has been established to stimulate the usage of solar energy. The main goals of the program are the assessment of technical and economically viable solar potential in order to define real objectives and tasks to provide use of exploitable indigenous clean and renewable energy potential. The Program addresses benefits, the most promising solar applications and solar potential. Much attention has been given to identification of obstacles and barriers in the process of solar technology dissemination. SUNEN is an initiative to increase solar energy use and to become more compatible with the present renewable energy sources policy in EU and Mediterranean countries. The program proposes twelve different types of thermal solar energy systems, which could be multiplied up to 28 000 installations until the year 2010 with annual heat recovery of approximately 1,5 TWh (5,4 PJ).     

Lipid composition of subcellular membranes of an FY1679-derived haploid yeast wild-type strain grown on different carbon sources.

The aim of the project EUROFAN (European Functional Analysis Network) is to elucidate the function of unknown genes of the yeast Saccharomyces cerevisiae at a large scale. Functional analysis is based on general and specific tests with yeast deletion strains. A prerequisite for these studies is a profound knowledge of the biochemistry and cell biology of the corresponding wild-type strain FY1679. As a contribution from our laboratory we present here a systematic lipid analysis of the major organelles isolated from FY1679 grown in the presence of different carbon sources. Phospholipid, sterol and fatty acid composition are characteristic for each organelle. Moreover, growth of the yeast on glucose, ethanol or lactate causes in some cases marked changes of the organelle lipid pattern. As the most prominent example, cultivation of the yeast on non-fermentable carbon sources results in an increase of mitochondrial cardiolipin. As another example, the ratio of unsaturated to saturated fatty acids is enhanced in cells grown on ethanol or lactate as compared to glucose. Thus, the lipid composition of yeast subcellular membranes reflects in a significant way the nutrient conditions caused by variation of the carbon source.     

Systematic analysis of yeast strains with possible defects in lipid metabolism

Lipids are essential components of all living cells because they are obligate components of biological membranes, and serve as energy reserves and second messengers. Many but not all genes encoding enzymes involved in fatty acid, phospholipid, sterol or sphingolipid biosynthesis of the yeast Saccharomyces cerevisiae have been cloned and gene products have been functionally characterized. Less information is available about genes and gene products governing the transport of lipids between organelles and within membranes or the turnover and degradation of complex lipids. To obtain more insight into lipid metabolism, regulation of lipid biosynthesis and the role of lipids in organellar membranes, a group of five European laboratories established methods suitable to screen for novel genes of the yeast Saccharomyces cerevisiae involved in these processes. These investigations were performed within EUROFAN (European Function Analysis Network), a European initiative to identify the functions of unassigned open reading frames that had been detected during the Yeast Genome Sequencing Project. First, the methods required for the complete lipid analysis of yeast cells based on chromatographic techniques were established and standardized. The reliability of these methods was demonstrated using tester strains with established defects in lipid metabolism. During these investigations it was demonstrated that different wild‐type strains, among them FY1679, CEN.PK2‐1C and W303, exhibit marked differences in lipid content and lipid composition. Second, several candidate genes which were assumed to encode proteins involved in lipid metabolism were selected, based on their homology to genes of known function. Finally, lipid composition of mutant strains deleted of the respective open reading frames was determined. For some genes we found evidence suggesting a possible role in lipid metabolism. Copyright © 1999 John Wiley & Sons, Ltd.     

Polyurethane coatings from liquefied wood containing remains of a copper‐, chromium‐, and boron‐based wood preservative

Preparation of polyurethane wood coatings based on copper‐, chromium‐, and boron (CCB) containing liquefied wood was performed, as an alternative way to manage postconsumed preservative‐contaminated wood. Additionally, we examined the possibility of improvement of selected properties of the liquefied wood‐based coatings by an addition of silica nanoparticles. The constituents of the CCB wood preservative do not exhibit an influence on a liquefaction process and on composition of the liquefied mixture. CCB also does not affect curing of the formulations containing liquefied wood and an isocyanate‐type hardener. Furthermore, influence of CCB on adhesion strength of liquefied wood‐based coatings on a wooden substrate, their hardness, and resistance to scratching and to water, acetone, and alcohol, is not exhibited. However, apart from these, from the applicative point of view, positive results, any improvement of the coating properties by the addition of silica nanoparticles is not shown. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40865.