Authors:L. Nagy, T. Gajda, J. Kürti, K. Schrantz, and K. Burger
Iron(III) complexes of D-saccharose and D-glucose were prepared. The compositions of the complexes were determined by standard analytical methods. The Mössbauer spectra reflected the presence of high-spin iron(III) in the polynuclear species. EPR spectroscopy demonstrated antiferromagnetically coupled iron(III) centers within the solid complexes. The13C NMR spectra indicated the presence of a mixture of coordination isomers of iron(III) complexes containing the sugar ligand in differently bound forms.
Authors:L. Nagy, G. Török, N. Vajda, and I. Gerlei
Several sorbents were prepared by precipitating zirconium phosphate on activated carbon support material. The main parameters
of the chemical procedure were optimized in order to obtain the highest decontamination factors which can be achieved in the
case of Cs+, Sr2+ and I− ions. For the characterization of the sorbents, sorption isotherms and capacity data were determined. The reproducibility
of the preparation is about 10%.
Authors:K. Szabó, L. Nagy, G. Török, D. Hegedüs, and G. Fóti
A control system for monitoring the radioactive concentration in aqueous wastes of nuclear installations was elaborated. The
mobile station developed for in situ control enables simultaneous measurement of gamma radiation in the energy range of 0.15–2.0
MeV and that of beta radiation in the energy range of 0.3–2.0 MeV by means of a combined scintillation detector. Disturbing
effects of accompanying and secundary radiations on the determination of the counting efficiency vs. radiation energy functions
used in calculation of the radioactive concentration limits as well as some experiences during a long time of operation of
the system have been discussed.
Authors:A. Megyes, J. Nagy, T. Rátonyi, and L. Huzsvai
The objectives of this study were to examine the correlation between factors of great significance for crop production, especially between irrigation and fertilization, and to evaluate the effects of irrigation and fertilization on maize yields over four growing seasons (2001-2004) in a long-term field experiment set up at the Látókép Experimental Station of the Centre for Agricultural Sciences of Debrecen University. The results showed that irrigation and fertilization were strongly correlated with the yield. The effect of irrigation depended on the natural water and nutrient supplies of the soil, and on the specific fertilizer rates. The results indicated that both fertilization and irrigation had a significant effect on the yield. The correlation between the year and the crop production factors was also significant. The yield-increasing effect of irrigation and fertilization differed significantly in the experimental years.
Authors:T. Rátonyi, L. Huzsvai, J. Nagy, and A. Megyes
The cultivation technologies for the dominant crops in Hungary need to be improved both in the interests of environmental protection and to reduce cultivation costs. A long-term research project was initiated in order to determine the feasibility of conservation tillage systems. The aim of the experiments was to evaluate conservation farming systems in Hungary in order to achieve more economical and more environment-friendly agricultural land use. Four tillage systems, namely conventional tillage (mouldboard plough), conservation tillage I (primary tillage with a J.D. Disk Ripper), conservation tillage II (primary tillage with a J.D. Mulch Finisher) and no tillage (direct drilling), were compared on a clay loam meadow soil (Vertisol). The physical condition of the experimental soils was evaluated using a hand-operated static cone penetrometer. Parallel with the measurement of penetration resistance, the moisture content of the soil was also determined. The grain yield of maize hybrids (Kincs SC , Occitán SC , Pr 37M34 SC , DeKalb 471 SC ) was measured using a plot combine-harvester. The analysis of soil conditions confirmed that if the cultivation depth and intensity are reduced the compaction of soil layers close to the surface can be expected. The decrease in yields (8-33%) in direct drilling (NT) and shallow, spring cultivated (MF) treatments, despite the higher available water content, can be explained partly by the compacted status of the 15-25 cm soil layer.
Authors:M. Molnár, L. Hornyák, R. Nagy, E. Márki, and Gy. Vatai
Our experiments were based on a model solution containing five of the main pineapple aroma components. Both sweeping-gas pervaporation and vacuum-pervaporation methods were carried out. Measurements were performed at different temperatures and feed flow rates. The purposes of this study were to examine applicability of the two pervaporation methods in reference to the pineapple aroma recovery, the effects of the operating parameters on the process, and modelling the pervaporation process by resistance-in-series model. Higher enrichment could be reached with vacuum-pervaporation than the sweeping-gas method. The separation process is determined by the diffusion of compounds in the membrane, thus the resistance in the boundary layer at liquid side is negligible. Based on performed experiments, the pervaporation process can be applied in beverage industry for aroma recovery.
Authors:A. Szabó, A. Gyepes, Á. Nagy, L. Abrankó, and J. Győrfi
Vitamin D2 is essential for the human body and mushrooms are proved to be one of the best sources of it. In our experiment biologically active, pre-harvest white and cream type button mushrooms and oyster mushroom were treated with UVB light in order to increase their vitamin D2 level, by transforming their natural ergosterol content into vitamin D2. UVB lamps (operating on 312 nm) and six time periods of irradiation (15 to 90 min) were used. After three consecutive days of treatments the yield were measured and samples were taken for vitamin D2 analysis. Data showed considerable increase in vitamin D2 levels at every time period in each cultivar.
Authors:A. Nagy, L. Jędrychowski, É. Gelencsér, B. Wróblewska, and A. Szymkiewicz
In recent years, research related to studying the effect of gut microflora on the human health has become of major economic importance. The main objective of our study was to examine whether or not the orally administered Lactobacillusstrains (LB) as an oral adjuvant can improve the mucosal immune protectionviaan enhanced IgA secretion to a co-administered marker antigen ovalbumin (OVA). We adapted a murine (BALB/c) model to demonstrate beneficial adjuvant effects of probiotic LB strains. Orally sensitised mice with OVA, which were prefed with native or heat denatured (HD) Lactobacillus salivarius (Ls) or Lactobacillus casei (Lc) responded better or with the same efficiency to a vaccination with antigen (OVA) than mice that had been sensitised only with OVA or not sensitised at all. Antibody (IgA) responses in the gut were increased in response to vaccination with OVA in mice that had been prefed with native or heat denatured Ls or Lc followed by Ls or Lc and OVA feeding. In prefed groups, the OVA feeding alone primed for specific immune response, while adjuvanted OVA has increased the immune exclusion potential of the gut.