5 research outputs found
NĂ©hĂĄny palackozott romĂĄniai ĂĄsvĂĄnyvĂz jellemzĂ©se a teljes ĂĄsvĂĄnyi anyag tartalom alapjĂĄn: Characterization of some bottled Romanian mineral waters on the basis of the total mineral content
Romania has many mineral water sources due to its geological features. In the present study, bottles of 26 Romanian mineral water brands were obtained from the market to make a characterization based on the pH, conductivity, and fixed residue content. According to the total fixed residue, the distribution of low, medium, and highly mineralized water was 43.9%, 41.46%, and 14.63%, respectively. The mean of fixed residue concentration was 763.3 mg/L, ranging from 40.37 mg/L to 2603 mg/L. The pH values of the still mineral waters varied between 6.86 and 7.91, while the pH values of the sparkling mineral waters were the lowest (4.7). The conductivity was strongly related to the concentration of the ions, therefore the maximum measured conductivity for the still waters was 573 ”S/cm, for the partially sparkling waters 2133 ”S/cm, and for the sparkling mineral waters 3079 ”S/cm.
Kivonat
RomĂĄnia geolĂłgiai adottsĂĄgainak köszönhetĆen sok ĂĄsvĂĄnyvĂzforrĂĄssal rendelkezik. Jelen kutatĂĄs sorĂĄn 26 romĂĄniai palackozott ĂĄsvĂĄnyvizet elemeztĂŒnk, a pH, a vezetĆkĂ©pessĂ©g Ă©s a rögzĂtett maradĂ©ktartalom alapjĂĄn. A teljes fix maradĂ©kra összpontosĂtva az alacsony, közepes Ă©s erĆsen mineralizĂĄlt vĂz eloszlĂĄsa ââ43,9%, 41,46% Ă©s 14,63% volt. A rögzĂtett ĂĄtlagos maradĂ©ktartalom 763,3 mg/l volt, ugyanakkor 40,37 mg/l Ă©s 2603 mg/l között vĂĄltozott. Az szĂ©nsavmentes ĂĄsvĂĄnyvizek pH-Ă©rtĂ©kei 6,86 Ă©s 7,91 között vĂĄltoztak, mĂg a szĂ©nsavval dĂșsĂtott ĂĄsvĂĄnyvizek pH-Ă©rtĂ©kei a legalacsonyabbak (4,7). A vezetĆkĂ©pessĂ©g szorosan összefĂŒgg az ionok koncentrĂĄciĂłjĂĄval, Ăgy a szĂ©nsavmentes ĂĄsvĂĄnyvizek maximĂĄlis mĂ©rt vezetĆkĂ©pessĂ©ge 573 ”S/cm, a rĂ©szben szĂ©nsavas vizeknĂ©l 2133 ”S/cm, a szĂ©nsavas ĂĄsvĂĄnyvizek esetĂ©ben pedig a vezetĆkĂ©pessĂ©g 3079 ”S/cm volt. 
DesztillĂĄciĂł modellezĂ©sĂ©re alkalmas Ășj korrelĂĄciĂłs fĂŒggvĂ©nyek azeotrĂłp elegyek gĆz-folyadĂ©k egyensĂșlyi görbĂ©ire: New correlation functions of VLE-curves of azeotropic mixtures for distillation modelling purposes
The simulation of distillation processes require accurate vapour-liquid equilibrium (VLE) data, since even minor (few percent) of deviation of them could cause major differences between the model results and the real system behavior. The azeotropic mixtures are highly non-ideal systems, displaying exotic phase behavior, as inflection points, which create difficulties in fitting attempts. The VLE data are available in general as discrete values, but for modeling and design of the separation processes, continuous function would be more practical. We developed a simple method to identify several function types for fitting on VLE data for whole concentration domain. The results are empirical, as do not imply thermodynamic considerations. The fitting parameters of binary ethanol-water mixture VLE curve were determined, and give the lowest relative error, compared with the results from the literature data. The best fitted function was suitable for calculation of tray number of distillation column with McCabe-Thiele method, implementing them in an Excel spreadsheet, giving similar result with Vaxa McCabe-Thiele software. The methodology is suitable for fitting continuous functions on VLE data for non-ideal binary or multi-component mixtures both.
Kivonat
A desztillĂĄciĂłs folyamatok szimulĂĄciĂłja pontos gĆz-folyadĂ©k egyensĂșlyi adatokat igĂ©nyel, mivel ezek kismĂ©rtĂ©kƱ (nĂ©hĂĄny szĂĄzalĂ©kos) eltĂ©rĂ©se jelentĆs eltĂ©rĂ©seket okozhat a modell eredmĂ©nyei Ă©s a rendszer valĂłs viselkedĂ©se között. Az azeotrĂłp keverĂ©kek fokozottan nem-ideĂĄlis rendszerek, amelyek kĂŒlönös viselkedĂ©st mutatnak pl. ĂĄthajlĂĄsi ponttal rendelkeznek, ami nehĂ©zsĂ©geket okoz az illesztĂ©si megvalĂłsĂtĂĄsĂĄban. Az egyensĂșlyi adatok ĂĄltalĂĄban diszkrĂ©t Ă©rtĂ©kekkĂ©nt ĂĄllnak rendelkezĂ©sre, de az elvĂĄlasztĂĄsi folyamatok modellezĂ©sĂ©hez Ă©s tervezĂ©sĂ©hez a folyamatos görbĂ©k cĂ©lszerƱbbek. EgyszerƱ mĂłdszert dolgoztunk ki fĂŒggvĂ©nytĂpusok azonosĂtĂĄsĂĄra, melyek az egyensĂșlyi görbe teljes koncentrĂĄciĂł-tartomĂĄnyĂĄban illeszkednek. Az eredmĂ©nyek empirikusak, mivel nem alkalmaztuk termodinamikai meggondolĂĄsokat. MeghatĂĄroztuk a binĂĄris etanol-vĂz keverĂ©k egyensĂșlyi görbĂ©jĂ©nek illeszkedĂ©si paramĂ©tereit, amelyek az irodalmi adatok eredmĂ©nyeivel összehasonlĂtva a legalacsonyabb relatĂv hibĂĄt adtĂĄk. A legjobban illeszkedĆ fĂŒggvĂ©ny alkalmas volt a desztillĂĄciĂłs oszlop tĂĄnyĂ©rszĂĄmĂĄnak McCabe-Thiele mĂłdszerrel törtĂ©nĆ kiszĂĄmĂtĂĄsĂĄra, Excel tĂĄblĂĄzattal, hasonlĂł eredmĂ©nyt adva a Vaxa McCabe-Thiele szoftvere. A mĂłdszer alkalmas folytonos egyensĂșlyi fĂŒggvĂ©nyek illesztĂ©sĂ©re, nem-ideĂĄlis binĂĄris vagy többkomponensƱ keverĂ©kek esetĂ©re is
Transzportfolyamatok Ă©s mƱvelettan : LaboratĂłriumi ĂștmutatĂł = Process phenomena and unit operations. Laboratory guide
A mĂ©rnöki szemlĂ©let kialakĂtĂĄsĂĄban az elmĂ©leti alapok, valamint a gyakorlati ismeretek egyarĂĄnt fontos szerepet jĂĄtszanak. A jegyzet tartalmi felĂ©pĂtĂ©se Ă©s szerkezete igazodik a Transzportfolyamatok Ă©s MƱvelettan tĂĄrgyakhoz, elĆsegĂtve az elmĂ©leti ĂłrĂĄk ismeretanyagĂĄnak megĂ©rtĂ©sĂ©t Ă©s elmĂ©lyĂtĂ©sĂ©t. Ezek az ismeretek lehetĆvĂ© teszik a hallgatĂłk szĂĄmĂĄra a tĂ©nyleges technolĂłgiai folyamat mƱveletorientĂĄlt elemzĂ©sĂ©t az adatgyƱjtĂ©stĆl a mĂ©rlegeken keresztĂŒl a kĂ©szĂŒlĂ©kmĂ©retek technolĂłgiai meghatĂĄrozĂĄsĂĄig. Valamennyi laborgyakorlat leĂrĂĄsa tartalmazza a gyakorlat cĂ©ljĂĄt, az elmĂ©leti alapokat, a gyakorlati berendezĂ©st, a mĂ©rĂ©s Ă©s az adatgyƱjtĂ©s menetĂ©t, valamint az adatok feldolgozĂĄsĂĄnak Ă©s kiĂ©rtĂ©kelĂ©sĂ©nek eljĂĄrĂĄsait
Ălelmiszeripari mƱveletek Ă©s berendezĂ©sek. TervkĂ©szĂtĂ©si ĂștmutatĂł
A gyakorlatban alkalmazott technolĂłgiĂĄk tervezĂ©si szempontjainak megismertetĂ©se a mĂ©rnöki oktatĂĄs egyik alapvetĆ fontossĂĄgĂș feladata. Noha a modern technolĂłgiai berendezĂ©sek tervezĂ©se sorĂĄn több szempontot is figyelembe kell venni, jelent ĂștmutatĂł â mƱveletcentrikus megközelĂtĂ©se rĂ©vĂ©n â irĂĄnytƱkĂ©nt szolgĂĄl a hallgatĂłk szĂĄmĂĄra az Ă©lelmiszeriparban alkalmazott folyamattervezĂ©sben. A mƱszaki szĂĄmĂtĂĄsok ĂștvesztĆiben mĂ©g jĂĄratlan diĂĄkok szĂĄmos elmĂ©leti informĂĄciĂł mellett konkrĂ©t esettanulmĂĄnyok megoldĂĄsait is megismerve mĂĄr cĂ©ltudatosabban foghatnak neki egy hasonlĂł tematikĂĄjĂș önĂĄllĂł munkĂĄhoz. RemĂ©ljĂŒk, hogy hallgatĂłk generĂĄciĂłi fogjĂĄk hasznĂĄlni az ĂștmutatĂłt a tervezĂ©si feladatok sikeres elkĂ©szĂtĂ©sĂ©ben
Essential oil extraction from herbs and their use in the food industry
Essential oil extraction of wild caraway and thyme was performed using a classical (HD) and microwave hydro-distillation (MWHD) and a laboratory supercritical fluid extraction (SFE) with a carbon dioxide as solvent. Our experiments demonstrated that the extraction yield of the essential oil performed in same conditions was influenced by the location of growth area; the maximum extraction yield of 10 ml 100 g-1 caraway was obtained from dried seeds collected from CsĂkmadaras. This quantity far exceeded the yield of the ĂjtusnĂĄd samples. In the case of wild caraway (Carum carvi L.), the extraction method influenced thecomposition of the essential oil (carvone/limonene ratio), the highest limonene content being achieved by classical hydro-distillation. In the case of thyme, this effect was not detected, the thymol/carvacrol ratio was independent from the given extraction method. The obtained thyme essential oil possesses high antimicrobial activity demonstrated by agar diffusion test. The thyme extract provides a good protection against microorganisms collected on the surface of fresh vegetables following bacterial stains: Citrobacter portucalensis, Pseudomonas hunanensis, Pseudomonas baetica, Pseudomonas parafulva, Bacillus mojavensis and Enterobacter cloacae. Protective effect was also detected on the vegetable surface of by chitosan-based edible film coating during a 6-day-long storage period at a temperature of 4 °C. The caraway essential oil used as soft cheese seasoning with a direct, dilution-free method, proved to be unsuitable because the uneven distribution and confer a strong, unpleasant taste to the product in comparison with the ground wild caraway seed-dressed cheese