Microwave steam explosion and enzymatic hydrolysis of vine-branch

Our research target was to utilise vine-branch, existing in huge amounts, for energetic purposes. During our experiments, microwave (MW) treatments of different powers (400–1600 W), pressures (1–5 bar), temperatures (120–180 °C), and treatment times (3–30 min) were applied to change the physical condition of vine-branch. After MW, enzymatic hydrolysis (EH) was used (85–100 h, 37 °C). In addition, beside MW, comparisons were made regarding various treatment methods: untreated (UTE), cooking plate (CP), and autoclave (AC), to determine to what extent they affect the final glucose yield. This yield can even further be increased by MW pre-treatment (50 W, 3–30 min, 40 °C) of the enzyme used during the hydrolysis, which reinforces the argument that enzyme activity can be increased by irradiation. A difference of 22.1% was detected among the glucose yield values in untreated and treated enzyme processes

Combined microwave–convective drying of saccharomyces cerevisiae based yeast

Attention is paid to drying as a downstream processing of foodstuff as it is used finally for human consumption. In some cases the conventional (convective, contact or infrared) drying processes can damage the quality of food due to crusting phenomena, overheating or protein denaturation. Better results can be obtained using combined microwave–convective dehydration.The paper mainly focuses on the investigation of drying Saccharomyces cerevisiaepulp using the method of dielectric dehydration. A dried product with a residual fermentative activity of over 80% was produced with the application of a microwave–convective drying system. As a result the moisture content was lower than 10% calculated on dry basis. We permanently regulated the incident microwave power manually in order to eliminate the mentioned disadvantageous effects. This type of regulation was applied when the surface temperature reached 45 °C

Effects of soil compaction on cereal yield

This paper reviews the works related to the effect of soil compaction on cereal yield and focuses on research of field experiments. The reasons for compaction formation are usually a combination of several types of interactions. Therefore one of the most researched topics all over the world is the changes in the soil’s physical and chemical properties to achieve sustainable cereal production conditions. Whether we are talking about soil bulk density, physical soil properties, water conductivity or electrical conductivity, or based on the results of measurements of on-line or point of soil sampling resistance testing, the fact is more and more information is at our disposal to find answers to the challenges. Thanks to precision plant production technologies (PA) these challenges can be overcome in a much more efficient way than earlier as instruments are available (geospatial technologies such as GIS, remote sensing, GPS with integrated sensors and steering systems; plant physiological models, such Decision Support System for Agrotechnology Transfer (DSSAT), which includes models for cereals etc.). The tests were carried out first of all on alteration clay and sand content in loam, sandy loam and silt loam soils. In the study we examined especially the change in natural soil compaction conditions and its effect on cereal yields. Both the literature and our own investigations have shown that the soil moisture content changes have the opposite effect in natural compaction in clay and sand content related to cereal yield. These skills would contribute to the spreading of environmental, sustainable fertilizing devoid of nitrate leaching planning and cereal yield prediction within the framework of the PA to eliminate seasonal effects

Application of spatio-temporal data in site-specific maize yield prediction with machine learning methods

In order to meet the requirements of sustainability and to determine yield drivers and limiting factors, it is now more likely that traditional yield modelling will be carried out using artificial intelligence (AI). The aim of this study was to predict maize yields using AI that uses spatio-temporal training data. The paper has advanced a new method of maize yield prediction, which is based on spatio-temporal data mining. To find the best solution, various models were used: counter-propagation artificial neural networks (CP-ANNs), XY-fused Querynetworks (XY-Fs), supervised Kohonen networks (SKNs), neural networks with Rectangular Linear Activations (ReLU), extreme gradient boosting (XGBoost), support-vector machine (SVM), and different subsets of the independent variables in five vegetation periods. Input variables for modelling included: soil parameters (pH, P2O5, K2O, Zn, clay content, ECa, draught force, Cone index), micro-relief averages, and meteorological parameters for the 63 treatment units in a 15.3 ha research field. The best performing method (XGBoost) reached 92.1% and 95.3% accuracy on the training and the test sets. Additionally, a novel method was introduced to treat individual units in a lattice system. The lattice-based smoothing performed an additional increase in Area under the curve (AUC) to 97.5% over the individual predictions of the XGBoost model. The models were developed using 48 different subsets of variables to determine which variables consistently contributed to prediction accuracy. By comparing the resulting models, it was shown that the best regression model was Extreme Gradient Boosting Trees, with 92.1% accuracy (on the training set). In addition, the method calculates the influence of the spatial distribution of site-specific soil fertility on maize grain yields. This paper provides a new method of spatio-temporal data analyses, taking the most important influencing factors on maize yields into account

Stress physiology of palm trees II. The effect of heavy metals and high irradiance on the photosynthesis of palm Trachycarpus fortunei

A study was carried out to analyse the individual and combined effects of heavy metal toxicity and high irradiance on the photosynthetic characteristics of young, fully expanded leaves of palm seedling Trachycarpus fortunei under laboratory conditions. Heavy metals were found to inhibit both the light and dark reactions of photosynthesis and the inhibition was more affected in the light than in the dark. Single photoinhibitory conditions caused a 60 % decrease in the electron transport activity after 120 min of light exposure which was completely reversible in the dark. In contrast, the combined effect of high light and heavy metal treatment resulted in a 90 % decrease in the activity, but no reversible recovery in the dark could be detected. This indicated that the simultaneous effect of these two stress factors led to irreversible damages of the photosynthetic machinery and as a consequence caused the general destruction of the plant. Abbreviations and symbols: Fo: initial chlorophyll fluorescence; Fm: maximum total fluorescence; Fv: variable fluorescence; AFi: intermediate level of fluorescence induction; PSII: photosystem 2. &nbsp

Stress physiology of palm trees II. The effect of heavy metals and high irradiance on the photosynthesis of palm Trachycarpus fortunei

A study was carried out to analyse the individual and combined effects of heavy metal toxicity and high irradiance on the photosynthetic characteristics of young, fully expanded leaves of palm seedling Trachycarpus fortunei under laboratory conditions. Heavy metals were found to inhibit both the light and dark reactions of photosynthesis and the inhibition was more affected in the light than in the dark. Single photoinhibitory conditions caused a 60 % decrease in the electron transport activity after 120 min of light exposure which was completely reversible in the dark. In contrast, the combined effect of high light and heavy metal treatment resulted in a 90 % decrease in the activity, but no reversible recovery in the dark could be detected. This indicated that the simultaneous effect of these two stress factors led to irreversible damages of the photosynthetic machinery and as a consequence caused the general destruction of the plant. Abbreviations and symbols: Fo: initial chlorophyll fluorescence; Fm: maximum total fluorescence; Fv: variable fluorescence; AFi: intermediate level of fluorescence induction; PSII: photosystem 2. &nbsp