Bromus diandrus (Poaceae), an addition to the Bulgarian flora

The current report discusses Bromus diandrus, a new species in the flora of Bulgaria. A concise description of its morphological features with an emphasis on the characters that distinguish it from the already known representatives of Bromus sect. Genea in the country is presented. The newly established locality is characterized floristically and ecologically. The probabilities of the native or alien origin of the studied population are also discussed

New data on the ecological peculiarities and the distribution in Bulgaria of the vulnerable habitat F3.1d Balkan-Anatolian submontane genistoid scrub from the European Red List of Habitats

According to the first Red List assessment of European Habitats, only 6 types of heathland and shrub have conservation significance. Amongst them, one type - F3.1d Balkan-Anatolian submontane genistoid scrub, is endemic for a part of the Balkan Peninsula and the west Anatolian Peninsula. This habitat type comprises a complex of open shrub, herbaceous and chasmophytic plant communities, but mostly dominated by the species complex of Genista rumelica/G. lydia. It is represented by open low heathlands typically occupying volcanic rocky substrates under climatic conditions with a pronounced Mediterranean influence. The European distribution of these communities is limited to North-East Greece and South Bulgaria. They are also included in the Red Data Book of Bulgaria, vol. 3. Natural habitats, assessed as “Vulnerable”. Despite their significance for the vegetation cover of Bulgaria and their conservation value at national and European level, these communities remain poorly studied. The present study provides more detailed information on habitat’s distribution and area coverage in Bulgaria, as well as on its floristic and ecological structure

Phytosociological study of submontane genistoid scrub communities from the Southeastern Balkans

Genista lydia Boiss. is an endemic Balkan-Anatolian species which forms rare communities in the territory of south Bulgaria and northeast Greece. They are spread exclusively on acidic, siliceous substrates. This study presents new data on their distribution, floristic and ecological structure and phytosociological affinities. The research is based on 156 phytosociological relevés. Unweighted pair–group method with arithmetic averages (UPGMA) was employed and a detrended correspondence analysis (DCA) was performed prior to the syntaxonomical decision. Three new associations and the new alliance Genistion lydiae have been described and classified within the order Lavandulo stoechadis-Hypericetalia olympici Mucina in Mucina et al. 2016 of the class Cisto-Lavanduletea stoechadis Br.-Bl. in Br.-Bl. et al. 1940. The study has also emphazised the potential threats concerning a decline of the habitat area and proposed some conservation measures

Characterization of nanodimensional Ni-Zn ferrite prepared by mechanochemical and thermal methods.

Nickel zinc ferrite nanoparticles, Ni1−xZnxFe2O4 (x = 0, 0.2, 0.5, 0.8, 1.0), with dimensions below 10 nm have been prepared by combining chemical precipitation with high-energy ball milling. For comparison, their analogues obtained by thermal synthesis have also been studied. Mössbauer spectroscopy, X-ray diffraction, and magnetic measurements are used for the characterization of the obtained materials. X-ray diffraction shows that after 3h of mechanical treatment ferrites containing zinc are formed, while 6h of treatment is needed to obtain NiFe2O4. The magnetic properties of the samples exhibit a strong dependence on the phase composition, particle size and preparation method

Magnetska i magnetootporna svojstva tankih slojeva NiFe–Si načinjenih radiofrekventnim rasprašivanjem

The galvanomagnetic properties and some structural peculiarities of rf-sputtered alloy films (NI80Fe20)100-xSix at 0<x<30 at. % were studied and compared with the corresponding properties of evaporated films of the same thickness and composition. The content of silicon increased with the increasing of the velocity of deposition and led to the amorphousation of the films. Coercivity decreased with the velocity of growth but it did not depend on the thickness and on the velocity of film deposition. The magnetoresistance ratio Δ g/g of the sputtered films was about three times higher then that of the evaporated films.Galvanometrijska svojstva i neke strukturalne osobenosti tankih slojeva legure (Ni80Fe20)100−xSix načinjenih radiofrekventnim rasprašivanjem sa 0 ≤ x ≤ 30 atomnih postotaka eksperimentalno su proučavani i usporedeni s odgovarajućima svojstvima naparenih slojeva jednake debljine i sastava. Sadržaj silicija je povećavan povećanjem brzine polaganja a slojevi su postajali amorfni. Koercitivnost slojeva se smanjivala s brzinom rasta, ali nije ovisila o debljini i o brzini polaganja sloja. Magnetootporni omjer Δ g/g rasprašenih slojeva bio je oko tri puta veći nego za naparene slojeve

Phytosociological study of submontane genistoid scrub communities from the Southeastern Balkans

Genista lydia Boiss. is an endemic Balkan-Anatolian species which forms rare communities in the territory of south Bulgaria and northeast Greece. They are spread exclusively on acidic, siliceous substrates. This study presents new data on their distribution, floristic and ecological structure and phytosociological affinities. The research is based on 156 phytosociological relevés. Unweighted pair–group method with arithmetic averages (UPGMA) was employed and a detrended correspondence analysis (DCA) was performed prior to the syntaxonomical decision. Three new associations and the new alliance Genistion lydiae have been described and classified within the order Lavandulo stoechadis-Hypericetalia olympici Mucina in Mucina et al. 2016 of the class Cisto-Lavanduletea stoechadis Br.-Bl. in Br.-Bl. et al. 1940. The study has also emphazised the potential threats concerning a decline of the habitat area and proposed some conservation measures

Mechanochemical synthesis and characterization of nanodimensional iron–cobalt spinel oxides

Iron–cobalt spinel oxide nanoparticles, CoxFe3−xO4 (x = 1, 2), of sizes below 10 nm have been prepared by combining chemical precipitation with high-energy ball milling. For comparison, their analogues obtained by thermal synthesis have also been studied. The phase composition and structural properties of the obtained materials have been investigated by means of X-ray diffraction, Mössbauer spectroscopy, infrared spectroscopy, temperature-programmed reduction and magnetization measurements. X-ray diffraction shows that after 1 h of mechanical treatment ferrites are formed. The measurement techniques employed indicate that longer milling induces an increase in crystal size while crystal defects decrease with treatment time. Magnetization and reduction properties are affected by the particles size, the iron/cobalt ratio and the synthesis conditions

EXTENDED RSA-M ALGORITHM AS A WAY OF INCREASE COMPUTATIONAL COMPLEXITY OF CRYPTOSYSTEMS

Applications of extended and combined formant analysis of modern number theory are considered to protect binary information from hacking and deliberate distortion in various IT systems based on a modified RSA-m cryptosystem with fast key changes and encryption algorithms with independent transformation keys with guaranteed small or medium short-term secrecy. Such an approach can serve as one of the ways to increase the computational complexity of modern information security systems, increasing their crypto resilience and making them capable of overcoming the possible crisis of modern cryptography in the post-quantum period. Outlines the results of the development of high-speed ciphers based on controlled combinations of transformations

The multi-criteria analysis of corporate social responsibility: a comparative study of Russia, Bulgaria and Serbia

Cross-cultural research on corporate social responsibility (CSR) dealing with specific stakeholder groups is fairly rare in the existing literature. The aim of this research is to investigate the level of recognition of CSR in companies by employees working in micro/small, medium-sized and large companies. The research is based on the survey conducted in Bulgaria, Russia and Serbia with the employees' attitudes obtained via a structured questionnaire. A similar socio-historical background of the three countries and different levels of accomplished socio-economic development at present is taken into account. A proposed ranking methodology was based on the multi-criteria decision analysis approach, observed through five studied dimensions: environmental, social, economic, stakeholder and voluntariness. The ranking was carried out using the integrated Entropy-PROMETHEE-GAIA method, where the Entropy method was used for determining the weights of the criteria, whereas PROMETHEE-GAIA was used for final ranking. The obtained results were analyzed from the multi-cultural point of view and show more significant differences in the attitudes of employees from different countries, rather than when the size of a company is taken into consideration