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Összefoglalás.

Ipari környezetben, ahol az alapanyagok között por alapanyagú termékek találhatóak, felmerül a porrobbanás lehetősége, ez alól az energiaszektor sem kivétel. Ebben az iparágban is megjelentek a biomasszák mint energiahordozók, amely termékekről számos esetben bebizonyosodott, hogy porrobbanás-veszélyesek, ezért szükséges védelmi intézkedéseket tenni. Jelen közleményünkben összefoglaljuk azon vizsgálati eljárásokat, amelyekkel meghatározhatóak a későbbi védelmi intézkedések alapadatául szolgáló paraméterek. Ismertetjük a vizsgálati eljárásokat, berendezéseket, valamint néhány konkrét vizsgálati eredményt is bemutatunk.

Summary.

In an industrial environment where dust-based products are among the raw materials, the potential for dust explosion arises, and the energy sector is no exception. This industry has also started to use biomass as a source of energy, which has been shown in many cases to be explosive and therefore requires protective measures. In this article, we have presented the distribution of dust explosion accidents in the US in 2021, which shows that 4% of the accidents directly related to the energy industry are much higher than the direct proportion. The set of conditions required for such accidents to occur is described and the investigation procedures that can be used to determine the parameters that will form the basis for future protection measurements are summarized. These parameters include the maximum explosion overpressure (P_max), the explosion constant (K_st), the lower explosibility rate (LEL), the limiting oxygen concentration (LOC), the minimum ignition temperature of dust clouds (MIT), the layer ignition temperature (LIT), and finally the minimum ignition energy (MIE). The test procedures and equipment are described, and some concrete test results are presented. Determining these variables is essential for the design of explosion protection for a dust explosion hazardous technology or area. The description of the test procedures is based mainly on the standard specifications applicable in the European Union. The structure of the measurements and the interpretation of the results obtained are described through the analysis of a fermentation residual solid.

Összefoglalás.

Az elmúlt évtizedekben a globális felmelegedés hatásai Európában, azon belül a Kárpát-medencében is nyilvánvalóvá váltak, s ez a hatás jelentős mértékű az energiaszektorra is. A kizárólag az időjárás által befolyásolt függő fűtési és hűtési energiaigényt leíró technikai klímaindexek alakulását mutatjuk be Magyarországon, nevezetesen a fűtési foknap (Heating Degree Days) és a hűtési foknap (Cooling Degree Days) paramétereket vizsgáljuk. A jelen klímát leginkább jellemző éves és havi normálértékek mellett a változásokat is elemezzük. A múlt század elejétől a fűtési foknapok egyértelmű csökkenése, míg a hűtési foknapok egyértelmű emelkedése figyelhető meg. Országos átlagban 314,6 foknappal [°C nap] csökkent a fűtési foknapok éves összege a lineáris trendmodell szerint 1901-től, míg ugyanerre az időszakra 79,4 ℃ nappal nőtt a hűtési foknap értéke. A legutóbbi három évtizedben, a legintenzívebb melegedés időszakában igen markánsak a változások, s ez a folyamat minden bizonnyal folytatódik a század végéig és azon túl is.

Summary.

In recent decades, the effects of global warming have become evident in Europe, including the Carpathian Basin, and this impact is significant for the energy sector. The most obvious impact of climate change in Hungary is the increase in extremes associated with high temperatures. Not only summer, but also winter and transition seasons show a warming trend, affecting all productive and service sectors. Rising temperatures could lead to shorter heating seasons and milder cold months, potentially reducing heating energy demand. However the heat waves have become more frequent and intense due to warming, leading to an increase in cooling energy demand. In the first part of this article, we present the evolution of heating degree-days from the beginning of the last century to the present day for the whole area of Hungary. The heating degree day is an indicator of the energy consumption for heating of buildings, which depends only on the weather. That is a temperature value, expressed in °Cday, which is proportional to the amount of energy required to heat the indoor environment to a given temperature on a given day, taking into account the daily minimum, maximum and mean temperature for a specific base temperature (15.5°Cday). Importantly, its value does not depend on the insulation of the buildings, economic indicators or the type of energy sources. Essentially, the colder the weather, the more the air temperature deviates from the base temperature of 15.5 degrees Celsius, the more energy is needed to heat the indoor environment and the higher the heating degree day value will be. In addition, we present the analysis of cooling degree days. The cooling degree day is derived in a similar way, following the logic of the heating degree day derivation. Therefore, the warmer the weather and the higher the air temperature is above the base temperature of 22°C, the more energy is needed to cool the indoor environment.

Based on the results presented in the article, we can conclude that the annual as well as the monthly amounts of heating degree-days have decreased since the beginning of the last century, with the greatest decrease in mountainous areas and in Western Hungary. One of the few benefits of climate change is that less energy is needed to heat interiors, and this is particularly true for the last decades, when annual heating degree-day amounts were usually lower than normal. At the same time, as heating degree-days have decreased, as the heat waves have become more frequent and intense with warming, resulting in an increase in cooling degree-days. In Hungary, on average, the last 30 years have been characterised by the highest cooling degree-day values over the last century’s climate normal periods. On a national average, the annual amount of heating degree-days has decreased by 314.6°Cday according to the linear trend model since 1901, while the cooling degree-day value has increased by 79.4°Cday over the same period. During the period of most intense warming, the August weather-dependent cooling energy demand increased the most. Due to the urban heat island effect in the inner-city environment, cooling of buildings requires additional energy. The recent trends is likely to continue until the end of the century and beyond. Therefore important to monitor changes in climate parameters affecting energy security and to develop an effective strategy and action plans to address the climate risks for the energy sector.

Összefoglalás.

Jelen tanulmányunkban két Duna menti parti szűrésű vízbázis vizsgálatát tűztük ki célul. A Tiszta Ivóvíz: a biztonságos ellátás multidiszciplináris értékelése a forrástól a fogyasztóig című Nemzeti Kiválósági Program keretében két olyan kiemelt fontosságú parti szűrésű vízbázist vizsgáltunk, amelyek meghatározó szerepet játszanak a Fővárosi Vízművek ellátási területén, Budapesten. Választásunk a Szentendrei-szigeten található surányi vízbázisra, valamint a Csepel-szigeten található ráckevei vízbázisra esett. A két vízbázis vizsgálatának célja az volt, hogy a területen végzett terepi mérések és mintavételezések, valamint a modellezési szimulációk segítségével átfogó képet kapjunk ezen két terület hidrogeológiai viszonyairól, hidraulikai viselkedéséről. Ennek érdekében számos terepi mérést végeztünk, amelyek fontos adatokat szolgáltattak a két vízbázis hidrodinamikai modelljének felépítéséhez és kalibrációjához.

Summary.

In this study, we dealt with two significant riverbank filtration systems along the Danube: the Surány water base located on Szentendre Island and the Ráckeve water base located on Csepel Island. These are two important drinking water bases of the Budapest Water Works, which provide a significant proportion of the capital’s water needs and are of great importance from the point of view of water security. At these riverbank filtered water bases, water is produced with horizontal collector wells, which, thanks to their design, are capable of extracting large amounts of raw water. The aim of our work was to get to know the geological and hydrogeological conditions of the area using the tools of field measurements and geophysical measurements. To this end, we measured the following parameters in different temporal resolutions: water level, temperature, specific electrical conductivity, pH. In this study, we present the results that have more significant information. Geophysical tests were also carried out at the two water bases, which provided important information regarding the geological inhomogeneity. Using the field measurements, two hydrodynamic model was also built for each study area. Our field measurements were also a great help for the calibration of our model. In this study the calibration of these models was shown. The hydrodynamic models were performed in the modeling environment of the Groundwater Modeling System, using the MODFLOW code. The characteristic of the model is that the tentacle wells were defined using MODFLOW’s Revised Multi-Node Well package. With the help of these models we would like to determine the arrival times in the future, as well as examine different scenarios that can be linked to extreme weather conditions. Based on the field measurements, we can make the following main conclusions regarding the examined water bases:

• During the entire period of the year, the hydraulic gradient from the Danube side is greater than from the background direction. Based on this, we can say that the Danube is the dominant supply water source in both cases.

• The hydraulic gradient changes over time, which is constantly influenced by changes in the water level of the Danube and changes in the produced yields.

• As the hydraulic gradient changes, the speed of the water flow also changes, so the access time changes from time to time, even from day to day.

• The specific electrical conductivity measurements showed that the Danube’s flood causes a large decrease in the value of the specific conductivity in the northern area. In addition to the decrease in conductivity, the measurement results also show a time shift, which, does not necessarily show the value of the access time.

• Based on geophysical measurements, it can be said that the Ráckeve water base has greater inhomogeneity than the Surány water base. As a result, the zonal calibration of the hydrodynamic model of the Ráckeve water base became necessary.

Abstract

Thermomechanical treatments and variations in chemical composition during the production of these alloys allow their properties to be adjusted as necessary. In the present research, the influence of chemical modification was analyzed by adding a combination of two rare earth elements (lanthanum and cerium) and performing a pretreatment before natural and artificial aging. With this, it was observed that said chemical modification led to an increase in hardness after artificial aging and specific suppression of the hardening speed at room temperature, combined with a pretreatment process to improve the density of the nucleation site and take advantage of the possible vacancy capture effect. Furthermore, microstructural changes were observed in the study alloys by scanning electron microscopy. The above allows the design of alloy production processes according to the requirements of each application.

Abstract

Elderberry pomace, a by-product generated by elderberry processing industries, may be a favourable resource for further utilisation due to its components of high nutritional quality. In our research, elderberry pomace extract (EP) was added to apple juice as natural food additive for controlling microbial spoilage and enriching antioxidant components.

During the 8-week storage period of enriched apple juice (EPA) and control apple juice samples antioxidant properties were evaluated using the FRAP assay, Folin–Ciocalteu method, and pH differentiation method. The amount of polyphenols components was quantified using an RP-HPLC method. The microbiological status of samples was studied by determining the total viable and yeast/mould counts. The EPA is an important source of polyphenol components and other bioactive compounds, and the results suggest that extract of elderberry pomace could be a promising natural preservative to improve microbiological stability during refrigerated storage and increase the quality of apple juice.

Abstract

Myricetin has been reported to have a wide variety of beneficial physiological functions. The present study investigated the antihyperlipidaemic activity of myricetin against hyperlipidaemia of high-fat diet-fed obese rats. The four-week antihyperlipidaemic activity was assayed by giving different doses of myricetin to hyperlipidaemic rats. Results showed that myricetin could reduce the harm caused by oxidative stress, decrease thiobarbituric acid reactive substances value, and decrease total cholesterol and triacylglycerol levels of hyperlipidaemic rats. Quantitative analysis of gene expression showed that myricetin's lipid-lowering activity can be activated by downregulating gene expression of fatty acid synthase (FAS) and peroxisome proliferator-activated receptor-γ (PPARγ) with upregulation of hormone-sensitive lipase (HSL) mRNA level. Thus, myricetin had significant health benefits and could be explored as a potentially promising dietary supplement for treating hyperlipidaemia.

Abstract

Conversion of economic microcrystalline cellulose (MCC) into high value-added prebiotic glucans, is not only stimulates utilisation of renewable lignocellulosic biomass, but also provides cheap prebiotics to reduce high incidence of obesity and metabolic syndrome. Herein, glucans (C_0.25–C_0.50–C_1.00) from MCC were prepared by pre-impregnation with dilute sulphuric acid (0.25–0.50–1.00%) and ball-milling treatment for 1 h. NMR spectroscopy and gel-permeation chromatography of the glucan products showed a significant reduction in the degree of polymerisation (DP) and molecular weights (Mw). All prepared glucans improved gut stress evaluated by in vitro digestion and fermentation (young and aging mouse faecal inocula). C_1.00 with lower DP and Mw showed better water solubility, earlier peak, and exhibited increased 1-diphenyl-2-picrylhydrazyl activity, higher ratios of Lactobacillus to Escherichia coli, and a higher level of short chain fatty acids better than C_0.25 and C_0.50 treatment (P < 0.05). Better prebiotic effects were observed in aging mice than in young mice. The highest ratio of Lactobacillus to E. coli was a 2.13-fold increase for aging mice compared to a 1.79-fold increase for young mice, relative to the initial value after C_1.00 treatment. The study provides a novel pathway and a new resource for producing glucan.

Summary.

High-level radioactive waste can be safely disposed of in deep geological repositories, for which a possible geological environment in Hungary is the Boda Claystone Formation. In the repository site selection, the geochemical investigation of the host rock is necessary including the structural characterization. In this study, the porosity (p%~1.5% and 5.84%) and the T_2cutoff value (0.12 ms and 0.10 ms) of two siliciclastic rocks was determined by desktop low-field NMR, the value of which differed from the 3 ms accepted for clay-bound water and the 33 ms for movable water in clastic reservoirs. Based on the T_2cutoff, the producible porosity was found to be high, however, based on the T₂ distributions, the bound-water types dominate the composition of the water phase of the rock.

Összefoglalás.

Magyarországon a nagy aktivitású radioaktív hulladékok végső elhelyezése még nem megoldott probléma. Az IAEA ajánlásai alapján az ilyen hulladékok hosszútávú és biztonságos elhelyezése mély geológiai tárolókban valósítható meg, melynek kiválasztása folyamatban van. Az országos felmérés (screening) alapján a Bodai Aleurolit Formáció (BAF) bizonyult a legígéretesebb kőzetnek, melynek széleskörű jellemzése elengedhetetlen a tároló kialakításához. A tároló kőzet pórusszerkezetének, kötött és mobilis víztartalmának, permeábilitásának vizsgálata fontos a kőzet radionuklid visszatartó képességének szempontjából, valamint szükséges bemenő adatokat szolgáltat a radioaktív hulladéktároló létesítmények biztonsági elemzéséhez szorosan kapcsolódó modellszámításokhoz. Munkánk során kisterű mágneses magrezonanciás módszerekkel (NMR) jellemeztünk két különböző mélységből származó furatmintát (BCF1 és BCF2). A mintákban található víz T₂ relaxációs ideje alapján meghatároztuk a különböző víztípusokat és az általuk kitöltött pórusok méretét és arányát. Jellemzően három víztípust tudtunk elkülöníteni: az agyagos fázishoz kötött vizet (51-77%, d ~ 0.6 nm), a kapillárisokban kötött vizet (20-43%, d ~ 2-40 nm) és a nagyobb pórusokat kitöltő eltávolítható vizet (3-6%, d ~ 200-400 nm). A modell oldattal telített kőzetminták T₂ relaxációs idő eloszlásai alapján meghatároztuk azok porozitását (P% ~1,5% és 5,84%), melyek jó egyezést adtak a korábban He- piknométerrel és Hg porozimetriásan meghatározott értékekkel. A kőzet permeábilitására utaló és a kötött-mobilis vizek arányát jellemző T_2cutoff értékeket (0,12 ms és 0,10 ms) a mintákat oldattal telítve, majd 105°C-on történő szárításukat követően ezek jellemzéséből határoztuk meg. Az így kapott értékek eltérnek az irodalomban törmelékes kőzetekre elfogadott 33 ms-tól, illetve a kőzetek agyagos fázisához tartozó 3 ms-tól. A T_2cutoff alapján meghatároztuk a mobilis–kötött víz arányát (FFI/ BVI), mely alapján a minták nagy mennyiségben tartalmaznak eltávolítható vizet, azonban a T₂ eloszlások alapján a kötött víztípusok a dominásnak. A T_2cutoff értékét és az FFI / BVI arányát jelentősen befolyásolhatja a kőzet szárításának módja, mivel a magas hőmérsékleten való szárítás az agyagos fázis vízvesztéséhez vezethet, mely így befolyásolhatja a minta száraz állapotú porozitását. Ezentúl, NMR MoUSE segítségével, egy még vákuumcsomagolt kőzetminta esetén elvégeztük annak felületi térképezését, mellyel el tudtuk különíteni az eltérő víztartalmú, ásványi összetételű részeit a furatmintának.