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- Author or Editor: M. Kassai x
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Long-term trials have a twofold role in life sciences, acting as both live laboratories and public collections. Long-term trials are not simply scientific curios or the honoured relics of a museum, but highly valuable live ecological models that can never be replaced or restarted if once terminated or suspended. These trials provide valuable and dynamic databases for solving scientific problems. The present paper is intended to give a brief summary of the crop production aspects of long-term trials.
Abstract
Co2+ ion penetration at different concentrations across animal models of human skin-five days old rat skin (without hairs) and nine days old rat skin (with hairs)—was studied in vitro in vertical diffusion cells. The results showed that the permeated amounts of Co2+ ions are proportional to its concentration in donor solutions, whereby permeated fractions are higher at lower concentrations. Results confirmed that the most important barrier against the penetration of ions is horny layer of the skin.
Abstract
Radioactive skin contamination with radionuclides in ionic forms after the permeation across skin models was studied in vitro. Using animal skin models of 5-day-old rat and 9-day-old rat, either intact or stripped, it was found that besides the transepidermal also the transfolicular flux can be important. Stratum corneum was found to be the principal permeation barrier in all cases. The study of penetration — time profiles revealed that permeated amounts were proportional to time in the case of 137Cs+ and 60Co2+, but they showed a local maximum in the case of 147Pm3+.
The statistical data show that the application of active cooling is spread widely in residential and commercial buildings. In these buildings, the ventilation is significantly increased in the whole energy consumption. There are similar problems in the operation of post-insulation of existing buildings. In this case, the energy consumption of the ventilation system gives a major proportion of the whole building services energy consumption. The opportuneness of this research shows that the actual available calculation procedures and technical designing data are only rough approximations for analyzing the energy consumption of air handling units and the energy saved by the integrated heat or energy recovery units. There are not exact methods and unequivocal technical data. In previous researches, the production and development companies have not investigated the effectiveness of the energy recovery units under difference ambient air conditions and the period of defrost cycle when the heat recovery can only partly operate under difference ambient air temperatures. During this term, a re-heater has to fully heat up the ambient cold air to the temperature of supplied air and generate the required heating demand to provide the necessary indoor air temperature.
Abstract
The composition and the permeation properties of the skin are dependent on age. In the animal models for permation studies, age affects the mechanical as well as the permeation properties significantly. The time dependence of permeation of 147Pm3+ from aqueous solution was established by the animal skin model and the age dependence of promethium permeation through the skin was examined. The aim was to find the optimum rat skin age model for radionuclide permeation studies and to assess the relative importance of the main permeation pathways: transepidermal and transfollicular permeation. The skin from 5-day-old rats (5DR) was found to represent the optimum animal model to study transepidermal permeation of ions. The skin from 9-day-old rats (9DR) was selected to study transfollicular permeation of ions. Comparison of the permeated amounts of promethium through the skin without hairs (3 DR to 6 DR) and with hairs (7DR to 12DR) showed that the additional permation mode via follicles significantly contributed to the permeation rate and extent.
Six wheat varieties representing different genotypes were tested under exposed and protected conditions in a three year herbicide provocation field trial at Nagygombos, Hungary. Three types of herbicide treatments (fluroxipir, bromoxynil and dicamba ai.) were applied in comparison with untreated and mechanical treated controls. Weed populations were sorted into two major groups according to the level of their occurrence. The result of experimental treatments were evaluated and weed tolerance of varieties was determined. The magnitude of weed populations has shown significant differences. All weed control treatments, including chemical and mechanical applications, had an influence on weed development. Herbicide treatments had about fifty per cent, while mechanical applications had a nearly hundred per cent effect concerning weed reduction. The latter can be considered as a level of total weed extinction. High weed canopies were observed in the case of untreated controls only. Wheat cultivars have shown a variety specific yield response. The results obtained suggest varietal differences concerning weed tolerance. The extent of yield losses between wheat cultivars ranged from 4 to 18 per cent of grain yield. In the trial Martonvásári 19 and Martonvásári 21 wheat varieties were proven to have the best weed tolerance abilities.
Agriculture is highly affected by climate change. Climate change impacts may influence almost all fields of agricultural activities; production efficiency, quantitative and qualitative deterioration of crop yields produced for alimentary purposes, and determine post-harvest manifestation of agricultural products inducing hazard in the field of food safety, transport, storage and distribution. Soil-climatic conditions, amount and distribution of precipitation, anomalies and extremities of temperature as well as various manifestation of air movement from stand still to storms are some of the main factors that may influence agriculture. Pollution has been considered solely as the presence of unfavourable alien matter in the environment, but in reality pollution is far more than that. Agri-environmental pollution is largely independent of mankind, since many pollution or degradation processes may begin with no direct relationship to human activities. Soil degradation, or irreversible damage to natural ecosystems by climatic factors (drought, flood, water logging, salinity) are the most frequent consequences. Biological pollution, like weed infestation, epidemics and gradations, pollen allergy, the poisonous effect of mycotoxins on farm animals and humans, new pests and diseases, the emission of greenhouse gases, and biological factors which cause quality deterioration represent an increasing pressure on agri-environment. This paper is intended to give an overview of some research activities and their results in relation with climatic aspects of agri-environmental pollution in Hungary.
