The method of Non-equilibrium Energy Spectrum (NES) was applied in measurement of hydrogen bonds energy distribution in 1% Rosa damscena L. oil solution in deionized water. Local maxima in this spectrum were identical with these obtained in investigations of other biologically active solutions and related to particular bio effects as follows: (-0.1387 eV; 8.95 µm; 1117 cm-1). This local maximum is typical for antibacterial, anti-tumor and anti-inflammatory effects. The local maxima at (-0.1212 eV; 10.23 µm; 978 cm-1) and (-0.1262 eV; 9.82 µm; 1018 cm-1) are typical for anti-inflammatory effects and this at (-0.1112 eV; 11.15 µm; 897 cm-1) is typical for effects on the nervous system and nerve conductivity. Information theoretical analysis was performed using the values of Shannon entropy and Transformational information entropy, pointing to hydrogen bonds distribution similarities between Rosa damscena L., V. myrtillus L. and Salvia divinorum Epling. The possible chemical causes of these similarities were identified as antioxidant activity and polyphenols concentration.

The recently developed model of the epidemic spread of two virus stains in a closed population is generalized for situation typical for the couple of strains delta and omicron, when there is high probability for omicron infection enough soon after recovering from delta infection. This model can be considered as some kind of weave of SIR and SIS models for the case of competition of two strains of the same virus having different contagiousness in a population.

The effectiveness of the application of EVOagri technology for purification of water and its use in agriculture in some African countries (Zimbabwe, Burundi, Egypt and Uganda), Nepal (Asia) and in Europe (Italy and Bulgaria) was evaluated. The performance of EVOdrop turbine for water filtration was analysed and the physicochemical composition of water was tested. This was determined in compliance with Ordinance No. 9/2001, published in the Official State Gazette, issue 30, and decree No. 178/23.07.2004, Bulgaria, European Union on the quality of water intended for drinking and household purposes. The results showed a significant increase in production yield of the tested Solanum spp. and lettuces in Zimbabwe, as well as of dill, spinach and onions in Egypt. Treatment of high-salt irrigation water in Burundi with EVOagri reduced its toxic effect upon vegetable plants. In Uganda, plants absorbed 23% less water, when filtered with EVOagri technology. In Italy, 21% water conservation was achieved through the usage of EVOagri technology. Stimulation of seed-germination after soaking with EVOagri water was established in Burundi and Nepal. The importance of the type and composition of irrigation water for crop growth was proved by the experiments in Bulgaria. In Bulgaria, onion seeds were planted in two separate pots. The first one was watered with tap water and this was taken as the control sample with tap water. The second one was watered with EVOdrop filtered water which was saturated with EVOdrop hydrogen technology (EVOwater). In Bulgaria, under natural conditions, Evodrop water was also tested in beans and the growth result was 11 % better than the control sample.

There are 225 mineral springs in Bulgaria, and out of them, 148 are in southern Bulgaria and 77 in northern Bulgaria. The region with mineral water “Varvara” is located in Rhodope mountains, Pazardzhik region, Bulgaria. Physicochemical and microbiological research of two springs from the village of Varvara is presented in the article. The springs are “Drilling No. 3 - Varvara” and “Drilling No. 5 – Varvara”. The physicochemical research of mineral waters showed that it is characterized as hydrothermal, mineralized, hydrocarbon-sulphate, sodium, silicon-rich and fluoride waters. The hyperthermal mineral spring “Drilling No. 3 – Varvara” is with t=79.9°С. The hyperthermal mineral spring “Drilling No. 5 – Varvara” is with t=83.7°С. The presence of single spores of species of genus Bacillus (Bacillus subtilis, Bacillus licheniformis), phylum Bacillota were found in the tested mineral waters. B. subtilis is a Gram-positive bacterium that forms heat-resistant spores. B. licheniformis is a Gram-positive, mesophilic bacterium and its optimal growth temperature is around 50°С. B. licheniformis can survive at higher temperatures. Geobacillus stearothermophilus also was registered in the tested mineral waters. It is a rod-shaped, Gram-positive bacterium, a member of the phylum Bacillota. The results show that the waters from both examined sources in Varvara are useful for human health according to their physicochemical composition. The content of silicon and calcium is a prerequisite for their application in strengthening the musculoskeletal system. The rich fluoride content allows their controlled use for reduction in dental caries. The waters from “Drilling No. 3 - Varvara” and “Drilling No. 5 - Varvara” did not show any sanitary- chemical and microbiological signs of contamination. This reveals opportunities for balneological therapy and tourism in this region. Bottling these waters would allow for their wider use.

In Bulgaria there are the following mountains – Stara Planina (Balkan), Rila, Pirin, Rodope etc. The name of the Balkan Peninsula is from the old name of the mountain Stara Planina – Balkan. In Bulagria there are 139 peaks more than 2000 m above sea level. The biggest peak in Balkan Peninsula is Mousala (2925 m). Teteven municipally has big part of Stara planina mountain with the highest peak Vezhen (2198 m). The event “Days of mountain water” is one of a kind in Bulgaria. It takes place on 11th June and lasts for several days in the Municipality of Teteven, Bulgaria. Its beginning dates from 2010, and it is a joint undertaking between Ignat Ignatov, Scientific Research Center of Medical Biophysics and Municipality of Teteven, Bulgaria. The event is connected with research of microbiological and physicochemical parameters of mountain spring waters from Municipality of Teteven, Bulgaria. The applied spectral method is „NES“. The analyses show the optimum quantity among the minerals of Calcium (Са2+), Magnesium (Mg2+), Potassium (K+), Sodium (Nа+), Manganese (Mn2+) and Zinc (Zn2+) that provide the right balance in the human body for health and longevity. Considered is the history of the event and what is achieved by the organizers. The emphasis is on the main objectives set out by the event, and the accomplished tasks for its successful delivering. Representatives of 15 states have participated in it – Bulgaria, Austria, Germany, Switzerland, Russia, USA, France, Israel, Czech Republic, Denmark, Turkey, Greece, Hungary and Serbia.  A survey was conducted regarding the event “Days of mountain water” in the Facebook group “Teteven Balkan”. 66 people responded on a random basis. The aim of the survey was the people to estimate how useful stay in Teteven municipality is. In the present article are listed in more detail the natural assets of municipal area of Teteven, located in “Fore-Balkan” in the central part of Stara planina Balkan range. The possibilities are shown for development of tourism in the region, its particular characteristics and specific features. Analyzed are the water resources, the mountain water as a factor for health and longevity. The information helps for development of tourism in the region. Described are the springs and fountains of mountain water in Teteven and its surrounding municipal areas. It is conducted quantitative and qualitative analysis of the chemical and physical parameters of the springs. On six of the springs are placed information signs about the chemical composition, physical parameters and properties relating to health.