97 resultados para FLD


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A fejlődést gazdasági növekedésként felfogókat bíráló hangok szórványosnak és erőtlennek hatnak, pedig a nyugati fogyasztói társadalom árnyoldalait és hosszú távú fenntarthatatlanságát taglaló tudományos igényű munkák ma már egyre szélesebb körben hozzáférhetők. A társadalmi szempontból megmutatkozó problémák mellett egyre nyilvánvalóbbá válnak a természeti környezet végességéből adódó nehézségek is. A környezeti problémák kapcsán sokat hallani a Föld népességének szabályozásáról és a tisztább termelés szükségességéről, ám az egy főre jutó fogyasztás tabunak látszik. Pedig az emberiség bioszférára gyakorolt összterhelését meghatározó képletnek ez legalább olyan fontos eleme, mint a népesség és a technológia. A fogyasztás mérséklésével kapcsolatos idegenkedés számos okra vezethető vissza. Ezek közül az egyik legfontosabb a személyes érintettség. Egy gazdaságilag fejlett ország polgára számára a népességnövekedés megállítása és a technológiafejlesztés igénye könnyen úgy értelmezhető, hogy ezek valaki más számára jelentenek tényleges feladatot. Ám ha a fogyasztásról esik szó, akkor óhatatlanul felbukkan a személy saját felelőssége is, hiszen valamennyien fogyasztók vagyunk.

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A cikk bemutatja, hogy az emissziós jogok mérleg- és beszámoló-képességi kritériumai milyen leképezést tesznek lehetővé a jelenleg érvényes Nemzetközi Pénzügyi Beszámolási Standardokban (IFRS, International Financial Reporting Standards). A vizsgálat fókuszában az üzemeltető áll, aki az Európai Unió kibocsátás-kereskedelmi rendszerének hatálya alá tartozik, azaz ipari tevékenysége folytán szén-dioxiddal szennyezi a Föld légterét. Az üzemeltető mint az emissziós jog tulajdonosa jelenik meg. A cikk megvizsgálja mindazokat a folyamatokat, melynek eredményeképpen birtokolhatja ezeket az egységeket, valamint azt, hogy az IFRS-ek milyen lehetőséget nyújtanak a különböző forrásból származó jogosultságok értékelésére. / === / The author presents that accounting and report ability criteria of the emission rights what mapping allows in the current International Financial Standards. The study focuses on the operator, who is the subject of the European Union Emissions Trading Scheme, whose industrial activities pollute with carbon dioxide to the earth’s atmosphere. The operator, as the owner of emission rights is displayed. This article examines those processes, which resulted in these units may be owned, and that what possibility is provided by IFRSs to evaluate rights from different sources.

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A gazdasági növekedésnek a válság miatti megtorpanása gondot okoz az embereknek, de furcsa módon „ajándék” a természetnek, mert a gazdasági növekedés lassulásával együtt csökken a környezetpusztítás sebessége is. Az utóbbi évtizedben annyit már elérték, hogy legalább az egy főre jutó, naturáliákban kifejezett anyag és energiafelhasználás nem növekszik Európában. Ez eredménynek tekinthető, bár ennél többet szerettek volna. De ha elérték volna a különféle világkonferenciákon eddig kitűzött célokat, az sem volna elég ahhoz, hogy a Föld kellemes élőhely lehessen 9 milliárd embernek.

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Napjaink világgazdasági egyenlőtlenségeinek megértésében nem érdektelen az egyes kultúrrégiók sajátosságainak ismerete. A globalizáció velejárója, hogy a különböző civilizációk érintkeznek („ütköznek”) egymással, amelyben nem egyforma eséllyel profitálnak, általában az erősebb még előnyösebb helyzetbe kerül. Alapvető kérdésként merül fel, hogy mi tesz egy kultúrrégiót a másikhoz képest erősebbé. Ennek nyilvánvalóan lehetnek a természeti erőforrások kultúrrégiónként eltérő eloszlásán alapuló anyagi okai, de vannak kultúrspecifikus tényezők is. A Föld társadalmai kulturális ismérveik alapján kilenc karakteres kultúrrégióba rendeződnek, amelyek eltérő módon reagáltak a világgazdaság kihívásaira a történelem során. Ennek lenyomata mai világgazdaságban betöltött helyzetük. A témakör a mozaikos világunk főbb kultúrrégiói közötti és azokon belüli különbségek és hasonlóságok iránt érdeklődők számára ajánlott.

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Az utóbbi évtizedekben a közgazdászképzésben háttérbe szorult a térbeli szemlélet jelentősége, pedig az információs társadalomban a gazdasági folyamatok már nem csak a fizikai térben, hanem a virtuális térben is tetten érhetők, régióról régióra változó életszínvonalat generálva. A tér digitális kiterjedése kölcsönhatásba kerül hagyományos fizikai környezetünkkel, ami még inkább amellett szól, hogy a közgazdász térszemlélet fontosságát e tanulmánykötettel kiemeljük. Tesszük ezt úgy, hogy a Corvinus Egyetem alapszakjainak hallgatóit szakonként szólítjuk meg egy-egy, számukra különösen releváns gazdaságföldrajzi témával. Ezáltal a többi magyarországi közgazdászképző intézmény szakjain tanuló hallgatók érdeklődését is felkelthetjük az új megközelítésű gazdasági térszemlélet iránt. Tartalomjegyzék: I. A népesség mint gazdaságföldrajzi tényező (Korompai Attila) - II. Városföldrajz (Jeney László) - III. Vidékföldrajz (Csatári Bálint) - IV. Településmarketing (Tózsa István) – V. Település- és területi tervezés (Forman Balázs – Szaló Péter) – VI. Földrajzi információs rendszerek és a Digitális Föld (Ferencz Viktória) – VII. Turizmusföldrajz (Kulcsár Dezső) – VIII. A világgazdaság új földrajza (Bernek Ágnes) – IX. A virtuális tér gazdasága (Mészáros Rezső – Jakobi Ákos) – X. A közlekedés földrajza (Jászberényi Melinda) – XI. Kereskedelmi földrajz (Sikos T. Tamás) – XII. A pénz földrajza (Forman Balázs) – XIII. Közigazgatási földrajz (Pálné Kovács Ilona) – XIV. Politikai földrajz (Kulcsár Dezső) – XV. Kultúrrégiók gazdaságföldrajza (Jeney László)

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Manapság, amikor a legfontosabb történések a Föld virtuális idegrendszerét jelentő számítógép-hálózatokon, azaz sehol és mindenhol zajlanak, mond-e valamit a címben jelzett két, nagyon is megfogható hely: az elegáns palota a Belváros szívében és az óriásreklámmal éktelenkedő betonszörny a balatoni autópálya torkolatában? A közgazdászok számára (kiváltképpen, ha idősebbek, mint a jubileumát ünneplő Közgazdaságtudományi Intézet) mindenképpen. Az INTÉZET – így csupa nagybetűvel – megalakulásától kezdve fogalom volt, a falai között zajló vitáknak hírértéket tulajdonítottak a szakmában. Néhány évtizede még a viccek is úgy kezdődtek, két közgazdász sétál a Nádor (akkor még Münnich Ferenc) utcában …

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Mai világunkban egyre több olyan erőforrást élünk fel, amelyek hatását az otthonunknak számító Föld egyszerűen már nem képes helyreállítani. Ebben számos jelenség mellett a gazdaság globalizációja, az élesedő versenyhelyzet, a fogyasztói társadalom további térnyerése, ebből adódóan pedig a logisztikai folyamatok intenzitásának növekedése kulcsszerepet játszik. A logisztikát érő kritikáknak ösztönözniük kell a vállalatok szakembereit arra, hogy változtassanak ezen. Ehhez elengedhetetlen a jelenlegi működés szénlábnyomának mérése. Csak a jelenállapot felmérése szolgálhat alapjául a fejlesztéseknek. A szerzők tanulmányának célja a szénlábnyomszámítás egy gyakorlati alkalmazásának ismertetése. Esettanulmány jelleggel bemutatják egy nagy nemzetközi vállalat hazai leányvállalatának a szénlábnyom-számítása során alkalmazott módszertanát. A számítások során a vállalat disztribúciós logisztikai folyamataira fókuszálnak, kiemelten vizsgálták a közúti szállítás és a raktározás széndioxid-kibocsátását. Számításaikban igyekeztek pontosak lenni, a hazai energiamixre számolt legfrissebb konverziós faktorokkal számoltak. Meggyőződésük, hogy az ilyen esettanulmányok hasznosak, hiszen a bemutatott módszertan mintául, útmutatásul szolgálhat további vállalatok számára. Reményeik szerint ezzel segíthetik, hogy minél több hazai vállalat kezdje el széndioxid-kibocsátásának szisztematikus és tudományos alapokon nyugvó mérését. ____ Due to globalization, intense competition and the consumer society logistics processes have been intensified during the last decades. This led to increased environmental strain generating intense criticism towards logistics profession. In order to decrease the environmental burden of logistics several professionals and companies have tried to make progress in this field and introduced techniques that are capable to measure the Carbon Footprint of logistics. Still public case studies are very limited. The paper presents the case of the Hungarian subsidiary of a big multinational FMCG firm. Calculations are built on the actual conversion factor developed for the Hungarian energy mix. A complex set of key performance indi actors usable to capture key characteristics of the present situation is presented. Not only the constructs of these KPIs are described in the paper but a detailed description of methodology used to calculate them is also given. The authors hope such detailed case study description will help other companies as well to initiate sustainable logistics programs.

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Harmful algal blooms (HABs) are a natural global phenomena emerging in severity and extent. Incidents have many economic, ecological and human health impacts. Monitoring and providing early warning of toxic HABs are critical for protecting public health. Current monitoring programmes include measuring the number of toxic phytoplankton cells in the water and biotoxin levels in shellfish tissue. As these efforts are demanding and labour intensive, methods which improve the efficiency are essential. This study compares the utilisation of a multitoxin surface plasmon resonance (multitoxin SPR) biosensor with enzyme-linked immunosorbent assay (ELISA) and analytical methods such as high performance liquid chromatography with fluorescence detection (HPLC-FLD) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) for toxic HAB monitoring efforts in Europe. Seawater samples (n = 256) from European waters, collected 2009–2011, were analysed for biotoxins: saxitoxin and analogues, okadaic acid and dinophysistoxins 1/2 (DTX1/DTX2) and domoic acid responsible for paralytic shellfish poisoning (PSP), diarrheic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP), respectively. Biotoxins were detected mainly in samples from Spain and Ireland. France and Norway appeared to have the lowest number of toxic samples. Both the multitoxin SPR biosensor and the RNA microarray were more sensitive at detecting toxic HABs than standard light microscopy phytoplankton monitoring. Correlations between each of the detection methods were performed with the overall agreement, based on statistical 2 × 2 comparison tables, between each testing platform ranging between 32% and 74% for all three toxin families illustrating that one individual testing method may not be an ideal solution. An efficient early warning monitoring system for the detection of toxic HABs could therefore be achieved by combining both the multitoxin SPR biosensor and RNA microarray.

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Harmful algal blooms (HABs) are a natural global phenomena emerging in severity and extent. Incidents have many economic, ecological and human health impacts. Monitoring and providing early warning of toxic HABs are critical for protecting public health. Current monitoring programmes include measuring the number of toxic phytoplankton cells in the water and biotoxin levels in shellfish tissue. As these efforts are demanding and labour intensive, methods which improve the efficiency are essential. This study compares the utilisation of a multitoxin surface plasmon resonance (multitoxin SPR) biosensor with enzyme-linked immunosorbent assay (ELISA) and analytical methods such as high performance liquid chromatography with fluorescence detection (HPLC-FLD) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) for toxic HAB monitoring efforts in Europe. Seawater samples (n = 256) from European waters, collected 2009–2011, were analysed for biotoxins: saxitoxin and analogues, okadaic acid and dinophysistoxins 1/2 (DTX1/DTX2) and domoic acid responsible for paralytic shellfish poisoning (PSP), diarrheic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP), respectively. Biotoxins were detected mainly in samples from Spain and Ireland. France and Norway appeared to have the lowest number of toxic samples. Both the multitoxin SPR biosensor and the RNA microarray were more sensitive at detecting toxic HABs than standard light microscopy phytoplankton monitoring. Correlations between each of the detection methods were performed with the overall agreement, based on statistical 2 × 2 comparison tables, between each testing platform ranging between 32% and 74% for all three toxin families illustrating that one individual testing method may not be an ideal solution. An efficient early warning monitoring system for the detection of toxic HABs could therefore be achieved by combining both the multitoxin SPR biosensor and RNA microarray.

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Os Hidrocarbonetos Aromáticos Policíclicos (HAPs) são contaminantes persistentes em meio aquoso. Estes compostos são conhecidos pelas suas propriedades carcinogénicas, mutagénicas e genotóxicas. O principal objetivo deste trabalho consistiu na avaliação das potencialidades de subprodutos da indústria corticeira, como adsorventes alternativos para a remoção de cinco HAPs em meio aquoso: benzo(a)pireno, benzo(ghi)perileno, benzo(b)fluoranteno, benzo(k)fluoranteno e indeno(1,2,3-cd)pireno. A metodologia analítica para quantificar os HAPs envolveu a preparação das amostras, através da técnica de extração em fase sólida (SPE), e a quantificação dos compostos analisados por cromatografia líquida com detetor de fluorescência (LC-FLD). O método foi otimizado e validado, obtendo-se limites de quantificação de 0,004 μg/L para todos os HAPs. Os estudos incidiram na utilização de uma amostra de cortiça, pó de aglomerado de cortiça expandida (PACE), obtida por aglutinação de cortiça em condições hidrotérmicas, a qual nos estudos preliminares revelou desempenho semelhante aos carvões ativados. Com exceção do benzo(ghi)perileno, os resultados mostram que o processo de adsorção dos HAPs na amostra PACE segue uma cinética de pseudo-segunda ordem e as isotérmicas ajustam-se ao modelo de Langmuir.

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People, animals and the environment can be exposed to multiple chemicals at once from a variety of sources, but current risk assessment is usually carried out based on one chemical substance at a time. In human health risk assessment, ingestion of food is considered a major route of exposure to many contaminants, namely mycotoxins, a wide group of fungal secondary metabolites that are known to potentially cause toxicity and carcinogenic outcomes. Mycotoxins are commonly found in a variety of foods including those intended for consumption by infants and young children and have been found in processed cereal-based foods available in the Portuguese market. The use of mathematical models, including probabilistic approaches using Monte Carlo simulations, constitutes a prominent issue in human health risk assessment in general and in mycotoxins exposure assessment in particular. The present study aims to characterize, for the first time, the risk associated with the exposure of Portuguese children to single and multiple mycotoxins present in processed cereal-based foods (CBF). Portuguese children (0-3 years old) food consumption data (n=103) were collected using a 3 days food diary. Contamination data concerned the quantification of 12 mycotoxins (aflatoxins, ochratoxin A, fumonisins and trichothecenes) were evaluated in 20 CBF samples marketed in 2014 and 2015 in Lisbon; samples were analyzed by HPLC-FLD, LC-MS/MS and GC-MS. Daily exposure of children to mycotoxins was performed using deterministic and probabilistic approaches. Different strategies were used to treat the left censored data. For aflatoxins, as carcinogenic compounds, the margin of exposure (MoE) was calculated as a ratio of BMDL (benchmark dose lower confidence limit) to the aflatoxin exposure. The magnitude of the MoE gives an indication of the risk level. For the remaining mycotoxins, the output of exposure was compared to the dose reference values (TDI) in order to calculate the hazard quotients (ratio between exposure and a reference dose, HQ). For the cumulative risk assessment of multiple mycotoxins, the concentration addition (CA) concept was used. The combined margin of exposure (MoET) and the hazard index (HI) were calculated for aflatoxins and the remaining mycotoxins, respectively. 71% of CBF analyzed samples were contaminated with mycotoxins (with values below the legal limits) and approximately 56% of the studied children consumed CBF at least once in these 3 days. Preliminary results showed that children exposure to single mycotoxins present in CBF were below the TDI. Aflatoxins MoE and MoET revealed a reduced potential risk by exposure through consumption of CBF (with values around 10000 or more). HQ and HI values for the remaining mycotoxins were below 1. Children are a particularly vulnerable population group to food contaminants and the present results point out an urgent need to establish legal limits and control strategies regarding the presence of multiple mycotoxins in children foods in order to protect their health. The development of packaging materials with antifungal properties is a possible solution to control the growth of moulds and consequently to reduce mycotoxin production, contributing to guarantee the quality and safety of foods intended for children consumption.

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Processed meat products are of worldwide importance and, because of their intrinsic factors as well as the processing methods, they are highly prone to fungal and mycotoxin contamination. Ochratoxin A (OTA) is the most significant mycotoxin in processed meat products. Penicillium nordicum is considered to be responsible for OTA contamination of meat products, as it is highly adapted to salt and protein-rich matrices and is moderately psycrotrophic. However, another OTA-producing fungus, Aspergillus westerdijkiae, adapted to carbon-rich matrices such as cereals and coffee beans, has been recently associated with high levels of OTA in meat products. Several Lactic Acid Bacteria (LAB) and yeasts have been tested as biocontrol agents against P. nordicum growth and OTA production in meat products, with promising results, but none of the studies have considered A. westerdijkiae. The aim of this work was to evaluate in vitro the effect of a commercial starter culture used in sausage fermentation and four yeasts isolated from dry-cured sausage on these two OTA-producing fungi, both in terms of fungal growth and of OTA production, using different meat-based culture media as model systems. The mechanisms underlying the observed effect were also studied. For this purpose, C. krusei, C. zeylanoides, R. mucilaginosa, R. glutinis, a mix of these yeasts and the starter culture were co-inoculated with P. nordicum and A. westerdijkiae in industrial sausage, traditional sausage, and ham-based media, under conditions of water activity, salt concentration and temperature that mimic real conditions at beginning and end of sausage curing process. Fungal growth was determined by measuring colony diameter, and OTA production was quantified by HPLC-FLD after extraction with methanol. Yeasts where found to inhibit significantly the growth of both fungi. P. nordicum was unable to produce detectable OTA in both sausage-based media under any condition. In ham, yeasts reduced OTA production, while the starter culture significantly increased it. Unexpectedly, OTA production by A. westerdijkiae was significantly stimulated in all media tested by all microorganisms. Matrix has a significant effect on OTA production by P. nordicum, but not by A. westerdijkiae, for which only temperature showed to have effect. By testing the mechanisms of action by which starter culture and C. zeylanoides influenced fungal responses, we were able to determine that direct contact and simultaneous growth of test organisms were the mechanisms more significantly involved in the responses. In conclusion, ochratoxigenic fungi do not all respond to antagonistic microorganisms in the same way. The use of biocontrol agents with the intent of reducing fungal growth and mycotoxin production by one fungus can have unexpected effects on others, thus leading to unforeseen safety problems. Further experiments are recommended to properly understand the reasons behind the different effects of microorganisms, to ensure their safe as biocontrol agents.

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Plants frequently suffer contaminations by toxigenic fungi, and their mycotoxins can be produced throughout growth, harvest, drying and storage periods. The objective of this work was to validate a method for detection of toxins in medicinal and aromatic plants, through a fast and highly sensitive method, optimizing the joint co-extraction of aflatoxins (AF: AFB1, AFB2, AFG1 and AFG2) and ochratoxin A (OTA) by using Aloysia citrodora P. (lemon verbena) as a case study. For optimization purposes, samples were spiked (n=3) with standard solutions of a mix of the four AFs and OTA at 10 ng/g for AFB1, AFG1 and OTA, and at 6 ng/g of AFB2 and AFG2. Several extraction procedures were tested: i) ultrasound-assisted extraction in sodium chloride and methanol/water (80:20, v/v) [(OTA+AFs)1]; ii) maceration in methanol/1% NaHCO3 (70:30, v/v) [(OTA+AFs)2]; iii) maceration in methanol/1% NaHCO3 (70:30, v/v) (OTA1); and iv) maceration in sodium chloride and methanol/water (80:20, v/v) (AF1). AF and OTA were purified using the mycotoxin-specific immunoaffinity columns AflaTest WB and OchraTest WB (VICAM), respectively. Separation was performed with a Merck Chromolith Performance C18 column (100 x 4.6 mm) by reverse-phase HPLC coupled to a fluorescence detector (FLD) and a photochemical derivatization system (for AF). The recoveries obtained from the spiked samples showed that the single-extraction methods (OTA1 and AF1) performed better than co-extraction methods. For in-house validation of the selected methods OTA1 and AF1, recovery and precision were determined (n=6). The recovery of OTA for method OTA1 was 81%, and intermediate precision (RSDint) was 1.1%. The recoveries of AFB1, AFB2, AFG1 and AFG2 ranged from 64% to 110% for method AF1, with RSDint lower than 5%. Methods OTA1 and AF1 showed precision and recoveries within the legislated values and were found to be suitable for the extraction of OTA and AF for the matrix under study.

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We explore the recently developed snapshot-based dynamic mode decomposition (DMD) technique, a matrix-free Arnoldi type method, to predict 3D linear global flow instabilities. We apply the DMD technique to flows confined in an L-shaped cavity and compare the resulting modes to their counterparts issued from classic, matrix forming, linear instability analysis (i.e. BiGlobal approach) and direct numerical simulations. Results show that the DMD technique, which uses snapshots generated by a 3D non-linear incompressible discontinuous Galerkin Navier?Stokes solver, provides very similar results to classical linear instability analysis techniques. In addition, we compare DMD results issued from non-linear and linearised Navier?Stokes solvers, showing that linearisation is not necessary (i.e. base flow not required) to obtain linear modes, as long as the analysis is restricted to the exponential growth regime, that is, flow regime governed by the linearised Navier?Stokes equations, and showing the potential of this type of analysis based on snapshots to general purpose CFD codes, without need of modifications. Finally, this work shows that the DMD technique can provide three-dimensional direct and adjoint modes through snapshots provided by the linearised and adjoint linearised Navier?Stokes equations advanced in time. Subsequently, these modes are used to provide structural sensitivity maps and sensitivity to base flow modification information for 3D flows and complex geometries, at an affordable computational cost. The information provided by the sensitivity study is used to modify the L-shaped geometry and control the most unstable 3D mode.