299 research outputs found
Ăšj fumonizin mikotoxinok tisztĂtása, szerkezet-meghatározása Ă©s toxikolĂłgiai vizsgálata. = Purification, structural elucidation and toxicological investigations of novel potentially hazardous fumonisin mycotoxins.
A fumonizinek a Fusarium gomba fajok által termelt kiemelkedĹ‘en toxikus mikotoxinok melyek leggyakrabban kukoricatermĂ©kekben fordulnak elĹ‘, ezĂ©rt egyre fontosabbak az Ă©lelmiszerbiztonság szempontjábĂłl. A tudományos tevĂ©kenysĂ©gĂĽnk során e mikotoxin csoport komplex kutatására fĂłkuszáltunk multidiszciplináris kutatĂłi megközelĂtĂ©st alkalmazva. A munka során 60 magyarországi Fusarium törzs fumonizin B1-4 termelĹ‘ kĂ©pessĂ©gĂ©t vizsgáltuk. A fumonizinek fermentáciĂłs karakterisztikáját felvettĂĽk Ă©s optimalizáltuk a maximális termelĂ©s Ă©rdekĂ©ben mikrobiolĂłgiai technikák alkalmazásával szilárd fázisĂş fermentáciĂłval. A termelĂ©s vizsgálata során számos Ăşj fumonizin vegyĂĽletet fedeztĂĽnk fel fordĂtott fázisĂş, nagy hatĂ©konyságĂş folyadĂ©kkromatográfia / elektrospray ionizáciĂłs repĂĽlĂ©si idĹ‘ Ă©s ion csapdás tömegspektrometria alkalmazásával. Mi Ărtuk le elsĹ‘kĂ©nt, hogy a mazsolaszemekrĹ‘l izolált Aspergillus törzsek is kĂ©pesek fumonizin termelĂ©sre. A munkánk további tĂ©mája volt a HPLC kapcsolt korona-kisĂĽlĂ©ses aeroszol detektoros analitikai mĂłdszer tesztelĂ©se Ă©s kifejlesztĂ©se a fumonisin szintek mĂ©rĂ©sĂ©re kukorica alapĂş mintákbĂłl. Az FB1 mikotoxin preparatĂv tisztĂtását a fermentált anyagbĂłl egy Ăşj, un. Centrifugális Megoszlási Kromatográfiás technikával valĂłsĂtottuk meg. A kĂsĂ©rleti eredmĂ©nyek alapján ez a tisztĂtási eljárás alkalmas FB1 referencia standard előállĂtására vagy a toxikolĂłgiához kapcsolatos tanulmányok szĂĽksĂ©gleteinek kielĂ©gĂtĂ©sĂ©re. | Fumonisin is a highly toxic mycotoxin of Fusarium mold species, which can be found mainly in corn products and gaining main interest in food safety. Our scientific activities were focused on the complex research of this mycotoxin group applying a multidiscipline approach. The fumonisin B1-4 toxin producing capacities of 60 strains of Fusarium verticillioides isolated in Hungary were screened. The fermentation characteristics of fumonisins were examined and optimized with microbiological techniques for the maximum production during a solid state fermentation. During production testing a number of novel fumonisin compounds were discovered by reversed-phase high-performance liquid chromatography/electrospray ionization time-of-flight and ion trap mass spectrometry. We described firstly that Aspergillus strains isolated from dried vine fruits can be also produce fumonisins. Further subject of our work was to test and to develop a HPLC coupled Corona Charged Aerosol Detector analytical method for the fumonisin measurements and to detect the level of fumonisins in corn-based samples. Furthermore, the preparative purification of FB1 mycotoxin was carried out from the fermented material using a novel Centrifugal Partition Chromatographic technique. Regarding the experimental results, the whole purification process may have the ability to be implemented for FB1 analytical standard production or to produce pure compound for studies related to toxicology
SOME ASPECTS IN THE DYNAMICAL TASKS OF THERMOELASTICITY: HEAT CONDUCTION PROBLEMS, NUMERICAL EXPERIMENTS WITH LONG BARS
The formulation of the dynamical task of thermoelasticity and the search for the possible
solutions is - because of the character of the problem - rather complicated. In the course of our
investigations we followed a complex method. The theoretical investigations referring to the basic
equations were supplemented by physical and numerical experiments. As a result we got new considerations referring to the modification oft he law of heat conduction, experimental arrangements
that serve to control the former, and numerical results referring to the thermal shock of long bars
that can be used in technical practice
THE SECOND SOUND PHENOMENON: PRO AND CONTRA
The paper deals with the problem of modification of Fourier Law. After a
short summary on the basic problem of the second sound phenomenon the different
opinions are listed and commented. Also the effect of the second sound
phenomenon on the thermoelasticity is analyzed
BASIC EQUATIONS AND DIFFERENT APPLICATIONS (BEDA) OF CONTINUUM MECHANICS
The equations of continuum mechanics can be split into
four groups, one of them contains the constitutive equations. The revision
of the system shows that all groups can be completed, but most of the
latest researches aim to the group of constitutive equations. In the present
paper we display the results of this revision
A termo-higro-mechanika (THM) elmĂ©leti vizsgálata Ă©s alkalmazása hĹ‘Ă©rzĂ©keny-higroszkopos, szálerĹ‘sĂtĂ©sű kompozitokhoz; az eredmĂ©nyek felhasználása gĂ©pjárműszerkezetekben = Theoretical investigations of thermo-hygro-mechanics (THM) and application to fiber reinforced thermo-hygroscopic composites; application in automotive industry
1.Uj eredmĂ©nyek 1.1.A THM elmĂ©letĂ©nek kiegĂ©szĂtĂ©se 1.2.A THM alkalmazása kompozitoknál 1.3.A fentiek járműipari alkalmazása 2.Az eredmĂ©nyek bemutatása, iskolák egyĂĽttműködĂ©se 3.TudományszervezĂ©si Ă©s általános művelĹ‘dĂ©si feladatok ad 11. -a second sound jelensĂ©g általánosĂtása -kiterjesztĂ©s: kapcsolt hĹ‘/nedvessĂ©g Ă©s diffĂşziĂł/konvekciĂł, second sound; mikrorepedĂ©sek, transzport ellenállás -a hĹ‘vezetĂ©s Ă©s a nedvessĂ©gdiffĂşziĂł közötti analĂłgia kiterjesztĂ©se a nedvessĂ©g Ă©s a kapcsolt hĹ‘/nedvessĂ©g konvekciĂłra; az átadási tĂ©nyezĹ‘k, az Onsager reláciĂł alkalmazása -a konvekciĂł általános Ă©rtelmezĂ©se az átadási mátrix segĂtsĂ©gĂ©vel, az átadási tĂ©nyezĹ‘k dimenzionálisan homogĂ©n felĂrása Ă©s a konvektivitás bevezetĂ©se -a second sound, termodinamika Ă©s hĹ‘rugalmasságtan -az anizotrĂłpia Ă©s inhomogĂ©nitás lehetsĂ©ges műszaki okai -a Duhamel-Neumann egyenlet kiegĂ©szĂtĂ©se -analitikus mĂłdszer a TH feladatok megoldására a villamos analĂłgia alapján -a reciprocitási reláciĂłk kiterjesztĂ©se a THM-re -a sugárzás szerepe ad 12. -Ăşj kĂsĂ©rletek Ă©s alkalmazások -szolár-energia szálerĹ‘sĂtĂ©sű kompozittal -THM Ă©s kompozitok Ă©ghetĹ‘sĂ©ge -bimaterial aktuátor fĂ©mszálerĹ‘sĂtĂ©ssel ad 13. -járművek Ă©ghetĹ‘sĂ©ge -elektromos erőátvitelű kerĂ©kpár szálerĹ‘sĂtĂ©sű kompozitbĂłl ad 2. -Lásd a kutatási eredmĂ©nyek rĂ©szletesebb leĂrásánál! ad 3. -agyagedĂ©ny-tervezĂ©s, THM Ă©s kĂ©pzĹ‘művĂ©szet, irodalom, tudománytörtĂ©net | 1.New Results 11.Developments to the Theory of Thermo-Hygro-Mechanics (THM) 12.Application of THM to Composites 13.Application in Automotive Industry 2.Publication of the Results, Cooperation of Schools 3.Science Policy and General Cultural Tasks ad 11. -generalization of the second sound phenomenon -extension: coupled heat/moisture, diffusion/convection, second sound; microcracks, transport resistance -extension the analogy between heat conduction and moisture diffusion to moisture and coupled heat/moisture convection, the convectivities, application of Onsager's relation -generalization of convection by the convectivity matrix, dimensional homogeneity of convectivities, the new notion of "convectivity" -second sound, thermodynamics and thermoelasticity -possible technological reasons of anizotropicity and inhomogeneity -completion of the Duhamel-Neumann equation -analytical solution for TH tasks based on electrical analogy -extension of reciprocal relations to THM -radiation ad 12. -new experiments and applications -solar energy by fiber reinforced composites -THM and the flammability of composites -bimaterial actuator with metal reinforcement. ad 13. -flammability of vehicles -bicycle with electrical power transmission made of fiber reinforced composite. ad 2. -See enclosed! ad 3. -clay-container, THM and fine-arts, literature, history of scienc
Continuummechanics – Heat Conduction – Cognition
Starting from the basic equations of solids we have shown one possible construction of the modification method of the law of heat conduction. Based on this method the steps of development can be outlined, the sequence and role of the tasks can be established. As an additional result we managed to highlight some aspects of the cognitive process, which emerge in the course of natural scientific research
Coupling of Generalized Heat and Moisture Transfer
The paper deals with the interdisciplinary problem of coupled diffusion and convention of crosscoupled heat
and moisture. After a summary on the well-known and often used cases, the
general governing equations are given with examples
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