It is important to work out precise and easy-to-use mathematical models to predict the indoor temperature in buildings for human residence. Such models can support model-based/predictive controls to efficiently maintain the temperature at a comfortable level.

The goal of this research is to examine the applicability of the Hottel–Whillier–Bliss model, developed for flat-plate collectors, to evacuated tube solar collectors. During this study, the model is applied to an evacuated tube collector, and then the identification and validation of the model are made with the help of measurements performed on the collector. This research also includes the application, identification and validation of the energy balance model for the investigated solar collector. This model works for both flat-plate and evacuated tube collectors. The results obtained with the two different models are then compared. By comparing the modelled results with the measured values, the accuracy and applicability of the models can be determined. Based on the results, the Hottel–Whillier–Bliss model works excellently with evacuated tube solar collectors for predicting the outlet temperature of the medium from the solar collector. It is important to note that the identification gives negative heat transfer parameter values. According to the validation, the average absolute error is 0.8 °C, and the average relative error is 1%. For the energy balance model, these values are 0.87 °C and 1.1% respectively, indicating that the accuracy of the Hottel–Whillier–Bliss model is very similar, and even slightly higher. Additionally, the research provides further proof of the applicability of the energy balance model to evacuated tube collectors.

Palinka production has a long tradition in Hungary and the neighboring countries. Previously, the fruit distillate was produced exclusively using the traditional Pot-Still Double Distillation (PSDD) technology. This distillation method means, in practice, a simple fractional distillation repeated twice. However, in other industries, such as the petroleum industry or the pharmaceutical industry, a continuous, so-called repeated distillation procedure is used (RCDS – Rectification Column Distillation Systems). In the production of palinka, the latter procedure has gained more and more ground in recent years, thus displacing the traditional technology. In the territory of today’s Hungary, there are more than 16,000 registered private palinka distillers. However, based on public databases, it is not possible to know the proportion of the two different palinka making processes used in palinka production. The two processes differ to a large degree. The amount of hearts obtained using the continuous operation plate rectification column (RCDS) is lower, while its alcohol content is very high: 75 – 90 vol%, depending on the fruit. On the other hand, when using the traditional pot-still double distillation (PSDD) method, the amount of hearts is higher, but its alcohol content is lower (60 – 70%). The continuous procedure, also called single-stage, is faster. This is one of the reasons for its popularity because it makes production more economical. The objective of our research was to find out whether a significant difference could be detected between the two plum palinkas produced using the two different distillation technologies, based on current legal requirements. Our research also included sensory testing to determine whether consumers could distinguish between the products manufactured in different ways. Our analyses were carried out in 2019 in the accredited laboratory of the National Food Chain Safety Office and among the students and staff of the Gödöllő campus of Szent István University.

The Earth's climatic system is greatly dependent on atmospheric mineral dust. Dust particles are regarded as one of the less well-known contributors to recent climatic changes, much like other aerosol constituents. Fifty to seventy percent of the world's budget for mineral dust comes from the Sahara Desert areas. These sources can produce dust-loaded air masses that can travel great distances and affect many parts of the world including Europe, the Middle East, North and South America. In March 2022 Europe faced two Saharan Dust storms (14-19 and 28-31), that affected many countries including Hungary. We used registered measurements of PM10 and PM2.5 concentrations from urban background air quality station in Budapest and MONARCH model to assess the effects of the two Saharan Dust storms on Budapest. As measured by daily average concentrations, PM10 and PM2.5 concentrations rose by 12 µg/m3 and 10 µg/m3 respectively during the first Saharan Dust event (SDE1), and by 14 µg/m3 and 5 µg/m3 during the Second Saharan Dust event (SDE2). While the effects of both SDEs on PM10 were nearly identical, SDE1 had a greater impact on PM2.5 concentrations than SDE2. Moreover, the dust load arriving to Budapest as estimated by the MONARCH model was higher in the SDE1 (1.26 g/m3), and that was associated with high values of dust surface concentration and Dust optical depth (243.1 µg/m3 and 0.71).

The studied solar pot is a recent invention, which is made for environmentally friendly cooking or heating (by utilizing solar energy) of foods and liquids. Its structure is similar to a double pipe heat exchanger, it has an outer mantle and an inner cooking tank. The goals of the paper are proposing a new physically-based mathematical model describing the solar pot and carrying out computer experiments with it, assembling an experimental system of the pot connected with a solar collector and performing measurements on it. Based on the results, the solar pot can successfully be used for cooking or sterilizing foods or liquids during the studied time period, in Hungary. In particular, based on measured data, the temperature level needed for heat treatment (75 °C) can be maintained in the cooking tank for several hours (~5 h, on the average) in a typical day in May.