Társadalmi konfliktusokat generáló ökológiai történések a Balaton életében az utóbbi néhány évtizedben – A víz barna elszíneződése

Ecological Developments of the Recent Decades Generating Social Conflicts in the Life of the Lake Balaton – Brown Discoloration of Water The largest quantities of brown coloured dissolved organic substances get into Lake Balaton in the Keszthely-basin through the River Zala and on the south shore from Nagyberek (peat bog) through pumping. Tourists avoid the beaches with brown water despite the fact that it does not pose any danger. Even though the humic substances causing the brown colour are not harmful for bathers, these compounds, however, do influence ecological processes. Humic substances are natural substances which are the decomposition products of dead plants. Their water-soluble fractions are fulvic acids and humic acids, while their third fraction (humin) is not water soluble. Humic substances play multiple ecological roles in surface waters: they serve as a carbon source for bacteria; change the underwater light climate through the increased attenuation of the short-wavelength ultraviolet (UV) radiation of the Sun; their photodegradation produces toxic free radicals containing oxygen (which is transformed to hydrogen peroxide); and they change the behaviour of other substances through their complex-forming property. A significant increase in the chromophoric dissolved organic matter load of the Lake can be anticipated because of the planned extension of the currently flooding area (16 km2) by the lower Kis-Balaton reservoir up to 52 km2.Ecological Developments of the Recent Decades Generating Social Conflicts in the Life of the Lake Balaton – Brown Discoloration of Water The largest quantities of brown coloured dissolved organic substances get into Lake Balaton in the Keszthely-basin through the River Zala and on the south shore from Nagyberek (peat bog) through pumping. Tourists avoid the beaches with brown water despite the fact that it does not pose any danger. Even though the humic substances causing the brown colour are not harmful for bathers, these compounds, however, do influence ecological processes. Humic substances are natural substances which are the decomposition products of dead plants. Their water-soluble fractions are fulvic acids and humic acids, while their third fraction (humin) is not water soluble. Humic substances play multiple ecological roles in surface waters: they serve as a carbon source for bacteria; change the underwater light climate through the increased attenuation of the short-wavelength ultraviolet (UV) radiation of the Sun; their photodegradation produces toxic free radicals containing oxygen (which is transformed to hydrogen peroxide); and they change the behaviour of other substances through their complex-forming property. A significant increase in the chromophoric dissolved organic matter load of the Lake can be anticipated because of the planned extension of the currently flooding area (16 km2) by the lower Kis-Balaton reservoir up to 52 km2

A Comparison of Two Formulas of Topical Menthol on Vascular Responses and Perceived Intensity Prior to and following a Bout of Maximum Voluntary Muscular Contractions (MVMCs)

The purpose of this study was to compare the vascular responses in the brachial artery and perceived intensity of two different formulas of topical menthol gels prior to and following a bout of maximum voluntary muscular contractions (MVMCs). 18 adults completed the same protocol on different days using blinded topical menthol gels (Old Formula and New Formula). Heart rate, brachial artery blood flow (ml/min), vessel diameter and reported intensity of sensation were measured at baseline (T1), at 5 min after application of the gel to the upper arm (T2), and immediately following five MVMCs hand grips (T3). The New Formula exhibited a significant decline in blood flow (−22.6%) between T1 and T2 which was not different than the nonsignificant declines under the Old Formula 1 (−21.8%). Both formulas resulted in a significant increase in perceived intensity of sensation between T1 and T2. Blood flow increased significantly with the New Formula (488%) between T2 and T3 and nonsignificantly with the Old Formula (355%)

Az ultraibolya sugárzás szerepe tavak oldott szervesanyagainak transzformációjában és degradációjában = Role of ultraviolet radiation in the transformation and degradation of dissolved organic substances in lakes

Sekély tavakra (30 magyarországi víztest, 140 mérés) ultraibolya (UV) és látható (PAR) hullámhossz tartományban többváltozós regressziós modelleket fejlesztettünk ki a fényabszorpciós komponensek: algák, algamentes lebegőanyagok, színes oldott szervesanyagok (CDOM) és a vertikális extinkciós koefficiensek (Kd) közötti összefüggés leírására. A modellek megadták az egyes komponensek specifikus Kd értékeit. Ezek, és a komponensek koncentráció értékei alapján vízalatti mérésre alkalmas radiométer hiányában in situ fénymérés nélkül kiszámíthatóak egy adott víztestre jellemző Kd értékek. A vizsgált tavakban a CDOM határozta meg a vízalatti UV klímát, az algák szerepe alárendelt volt. A PAR klímát a legtöbb víztestben a lebegőanyagok határozták meg, de hipertróf vizekben az algák, míg barna vizekben a CDOM volt a meghatározó. Kísérletesen megállapítottuk, hogy az UV sugárzás hatására az oldott szervesanyagok bomlottak, az oldott szervesszén (DOC) koncentrációja csökkent, a hidrogénperoxidé nőtt, miközben a szervesanyagok kémiai és fizikai tulajdonságai változtak, így barna színük fakult, fényabszorpciójuk és fluoreszcencia intenzitásuk csökkent, miközben a biológiailag hozzáférhető DOC koncentráció többszörösére nőtt. Kimutattuk, hogy az UV sugárzás hatása a bakterioplanktonra komplex, direkt gátló és indirekt gátló és serkentő hatás egyaránt érvényesült. A mikrobiális élőlényegyüttesek működése és a vízi szénforgalom megértése a CDOM fotolízisének ismerete nélkül nem lehetséges. | Multiple regression models were developed in the ultraviolet (UV) and visible (PAR) wavelength range to describe the relationship between light-absorbing components: algae, algal-free suspended solids, coloured dissolved organic matter (CDOM) and vertical attenuation coefficients (Kd) in shallow lakes (30 Hungarian water bodies, 140 measurements). The models have provided the specific Kd values of the components. Based on these and the concentration of the components, the Kd can be calculated without in situ measurement in the absence of an underwater radiometer. The underwater UV climate was mainly determined by CDOM in the studied lakes, the role of algae was negligible. The PAR climate was determined by suspended solids in most cases, but in hypertrophic waters the algae and in brown colour waters the CDOM was dominant. We have experimentally ascertained that the dissolved organic substances were decomposed by UV radiation: the DOC decreased, the H2O2 increased, while their brown colour faded, their absorbance and fluorescence intensity decreased, while the concentration of the biologically available DOC multiplied. We have found that the effect of UV radiation on bacterioplankton is complex: both the direct inhibitory and indirect inhibitory and stimulating effects were detected. Our research shows that the understanding of the functioning of microbial assemblages and the aquatic carbon cycle is not possible without the thorough knowledge of the photolysis of CDOM

The effect of the branched chain polypeptide carrier on biodistribution of covalently attached B-cell epitope peptide (APDTRPAPG) derived from mucin 1 glycoprotein

In order to establish structure–function relationship for the design of a new group of oligopeptide antigen–macromolecule conjugate, multiple copies of mucin-1 B-cell epitope peptide, APDTRPAPG were conjugated with branched chain polymeric polypeptides possessing poly[L-Lys] backbone. By the synthesis, radiolabelling (125I) and in vivo treatment of BALB/c mice with epitope conjugates containing XiK/XAK type carrier, where X = Glu (EiK or EAK) or Leu (LAK), the influence of the polypeptide structure on the blood clearance profile and on tissue distribution profile concerning the epitope delivery to relevant organs (e.g. immunocompetent or involved in excretion) were investigated. We observed significant differences in the blood clearance profiles for the conjugates, the respective polypeptide carriers and free epitope peptide. All conjugates, regardless of their charge properties exhibited longer presence in the circulation than the free oligopeptide. Tissue distribution data also showed that the structural properties (e.g. amino acid composition, charge) of the carrier polypeptide have marked influence on the tissue accumulation of the epitope peptide conjugates. In contrast to conjugates with linear (K) or branched chain (LAK) polycationic polymers exhibiting rapid blood clearance and high spleen/liver uptake, amphoteric epitope peptide conjugates with different branches, but similar charge properties (EiK or EAK) had extended blood survival and generally lower tissue accumulation. The results on this systematic investigation suggest that further studies on the immune response induced by these epitope conjugates would be needed to provide correlation between biodistribution properties (presence in the blood, level of tissue accumulation) and the capacity of these conjugates to elicit antibody production

A well-defined diamine from lignin depolymerization mixtures for constructing bio-based polybenzoxazines

The demand for high-performance materials is increasing, and most of these materials are petrol based. Therefore, the development of highly efficient and selective catalytic methods that allow access to industrially relevant polymer building blocks from complex biomass depolymerization mixtures is essential. Here, we report on a robust catalytic strategy to obtain the industrially relevant 4,4′-methylenebiscyclohexanamine (MBCA) from lignin oxidation mixtures and its use for constructing fully bio-based polybenzoxazines. The strategy consists of two challenging catalytic steps: 1) the funneling of lignin-derived bisphenol mixtures into 4,4′-methylenebiscyclohexanol (MBC) and 2) the highly selective amination of MBC with ammonia to obtain MBCA. The renewable polybenzoxazines were prepared from MBCA and phenolic lignin platform chemicals. The most promising, cured poly (S-MBCA), shows high glass transition temperature Tg of 315°C, outstanding thermal stability (T10% = 400°C), and good storage modulus (E′25°C = 3.8 GPa), which is competitive with commercial resins

Investigation of evolved layer structure of Ba-containing emission materials

The emission material in High Intensity Discharge (HID) lamps plays a significant role in lowering the electrode work function and thus the lamps´ operating temperature. Ba-containing rare earth- and alkali earth tungstate materials are commonly used as cathode thermionic emission materials because of the production of high intensity discharge. The goal of this present work is to model a cathode tip surface evolved during sintering and to compare the physical and chemical properties of emission materials currently used in the industry. In order to achieve this goal, we investigated and compared the layer structure of Ba-Ca- and Ba-Y-containing emission materials evolved on polycrystalline tungsten foils. Simultaneously, the tendency of the work function was also monitored as a function of Ba/BaO layer thickness. The Ba coverage of cathode is one of the most important factors during the lifetime of HID lamps. The initial Ba diffusion was also examined. We also proposed a layer model, valuable for the structures occurring during the operation of lamps. The chemical composition of the flat samples was analysed by X-ray Photoelectron Spectroscopy (XPS) and the electron emission properties by Work Function Spectroscopy (WFS)

A fitoplankton produktivitása és diverzitása pikoplankton dominanciájú vízterekben = Productivity and diversity of phytoplankton in picoplankton dominated water bodies

Feltártuk a bakteriális méretű algákban (pikoplankton) gazdag turbid vizekben a pikoplankton tömegének, összetételének, dinamikájának és fotoszintézisének alapvető jellemzőit. A fitoplankton tömege alapján ezek a tavak hipertrófok (a-klorofill>100 micro g/l), ugyanakkor a fénylimitáció miatt elsődleges termelésük a vártnál alacsonyabb volt. Vizükben a pikoplankton abundanciája egy-két nagyságrenddel nagyobb volt, mint más tavakban, télen a pikoeukarióták nyáron a pikocianobaktériumok domináltak a Balatonhoz hasonlóan. A Balatonban a pikoalgák részesedése az összes produkcióból 23-54% között volt. Megállapítottuk, hogy a pikoplankton abundancia folyó vizekben egy nagyságrenddel kisebb, mint tavakban, azonos fitoplankton biomassza esetén. A Balatonból egy új pikoeukarióta, a szikes tavakból egy új pikocianobaktérium morfotaxont írtunk le. A természetes pikoplankton együttesek molekuláris vizsgálata bizonyította, hogy a Pannon Biogeográfiai Régió víztereinek Synechococcus flórája igen gazdag és diverz. Az izolált pikocianobaktérium törzsek genetikai karakterizálása is ezt az eredményt támasztotta alá. A Böddi-székből izolált törzsek a pikofitoplankton klád egy új, eddig tenyésztésbe nem vont csoportját képviselik. Pikoeukarióta és pikocianobaktérium törzsek ökofiziológiai vizsgálatával bizonyítottuk, hogy a Duna-Tisza közi szikes tavakban (és minden bizonnyal más tavakban is) a fény és a hőmérséklet változása együtt szabályozza a pikoalgák szezonális szukcesszióját. | The abundance, composition, dynamics and photosynthesis of the bacterium-sized algae (picoplankton) has been studied in Hungarian turbid waters, where the abundance of picoplankton is one or two order of magnitude higher than in other lakes. Based on the phytoplankton biomass these ponds were hypertrophic (chlorophyll-a > 100 micro g/l), however the primary production was lower than expected due to light limitation. Picoeukaryotes dominate in winter, while picocyanobacteria dominate in summer, similarly to Lake Balaton, where the proportion of the picoplankton in the total primary production was 23 and 54%. It has been stated, that the picoplankton abundance in running waters was one order of magnitude lower, than in shallow lakes having the same trophic state. One new eukaryotic and one cyanobacterial picoalgal morphotaxa has been described. The molecular characterization of phytoplankton assemblages showed that the Synechococcus flora of the Pannon Biogeographic Region is very diverse. The molecular identification of isolated picocyanobacterial strains also confirmed these results. The picocyanobacterial strains isolated from Böddi-szék pond formed a new, distinct group inside the picophytoplankton clade. The ecophysiological studies of picoeukaryotic and picocyanobacterial strains showed that the light and temperature control together the seasonal succession of the picoplankton in turbid soda lakes in the Danube-Tisza Interfluve (and presumably in other shallow lakes)

Fermentative hydrogen production in anaerobic membrane bioreactors: A review

Reactor design considerations are crucial aspects of dark fermentative hydrogen production. During the last decades, many types of reactors have been developed and used in order to drive biohydrogen technology towards practicality and economical-feasibility. In general, the ultimate aim is to improve the key features of the process, namely the H2 yields and generation rates. Among the various configurations, the traditional, completely stirred tank reactors (CSTRs) are still the most routinely employed ones. However, due to their limitations, there is a progress to develop more reliable alternatives. One of the research directions points to systems combining membranes, which are called as anaerobic membrane bioreactors (AnMBRs). The aim of this paper is to summarize and highlight the recent biohydrogen related work done on AnMBRs and moreover to evaluate their performances and potentials in comparison with their conventional CSTR counterparts. © 2014 Elsevier Ltd

Review on the start-up experiences of continuous fermentative hydrogen producing bioreactors

The start-up of continuous biohydrogen fermentations is a complex procedure and a key to acceptable hydrogen production performance and successful long-term operation. In this review article, the experiences gained and lessons learned from relevant literature studies dealing with various aspects of H 2 producing bioreactor start-up are comprehensively surveyed. Firstly, the importance of H2-forming biosystem start-up including its main steps is outlined. Afterwards, the role of main influencing factors and methods (e.g. strain selection, seed pretreatment and inocula stimulation, switch-over time, bioreactor design, operating conditions) in avoiding the deterioration of starting a reactor is analyzed and presented in detail. Finally, the so far suggested applicable start-up strategies and the corresponding findings are critically discussed pointing out the advantages and disadvantages of each strategy. © 2014 Elsevier Ltd

Quasi-phase-matching high-harmonic radiation using chirped THz pulses

High-order harmonic generation in the presence of a chirped THz pulse is investigated numerically with a complete 3D nonadiabatic model. The assisting THz pulse illuminates the high-order harmonic generation gas cell laterally inducing quasi-phase-matching. We demonstrate that it is possible to compensate the phase mismatch during propagation and extend the macroscopic cutoff of a propagated strong IR pulse to the single-dipole cutoff. We obtain 2 orders of magnitude increase in the harmonic efficiency of cutoff harmonics (170 eV) using a THz pulse of constant wavelength, and a further factor of 3 enhancement when a chirped THz pulse is use