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Detalles de la revista
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Revista
eISSN
2603-347X
Publicado por primera vez
15 Dec 2015
Periodo de publicación
1 tiempo por año
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Volumen 5 (2018): Edición 1 (March 2018)

Detalles de la revista
Formato
Revista
eISSN
2603-347X
Publicado por primera vez
15 Dec 2015
Periodo de publicación
1 tiempo por año
Idiomas
Inglés

Buscar

14 Artículos
Acceso abierto

Editorial Note: Where Science Meets Art (II)

Publicado en línea: 07 Mar 2018
Páginas: 4 - 5

Resumen

Acceso abierto

Thermodynamic model for solution behavior and solid-liquid equilibrium in Na-Al(III)-Fe(III)-Cr(III)-Cl-H2O system at 25°C

Publicado en línea: 07 Mar 2018
Páginas: 6 - 16

Resumen

Abstract

The knowledge of the thermodynamic behavior of multicomponent aqueous electrolyte systems is of main interest in geo-, and environmental-sciences. The main objective of this study is the development of a high accuracy thermodynamic model for solution behavior, and highly soluble M(III)Cl3(s) (M= Al, Fe, Cr) minerals solubility in Na-Al(III)-Cr(III)-Fe(III)-Cl-H2O system at 25°C. Comprehensive thermodynamic models that accurately predict aluminium, chromium and iron aqueous chemistry and M(III) mineral solubilities as a function of pH, solution composition and concentration are critical for understanding many important geochemical and environmental processes involving these metals (e.g., mineral dissolution/alteration, rock formation, changes in rock permeability and fluid flow, soil formation, mass transport, toxic M(III) remediation). Such a model would also have many industrial applications (e.g., aluminium, chromium and iron production, and their corrosion, solve scaling problems in geothermal energy and oil production). Comparisons of solubility and activity calculations with the experimental data in binary and ternary systems indicate that model predictions are within the uncertainty of the data. Limitations of the model due to data insufficiencies are discussed. The solubility modeling approach, implemented to the Pitzer specific interaction equations is employed. The resulting parameterization was developed for the geochemical Pitzer formalism based PHREEQC database.

Acceso abierto

Allenephosphonic phosphine oxides in reactions with electrophilic reagents

Publicado en línea: 07 Mar 2018
Páginas: 17 - 23

Resumen

Abstract

The reactivity of the titled compounds towards electrophilic reagents has been investigated and new experimental evidences for the mechanism of the electrophilic addition reactions to 1,2-alkadienephosphonates have been reported

Palabras clave

  • electrophilic addition
  • nucleophilic addition
  • 1,2-alkadienephosphonates
Acceso abierto

Descriptor Fingerprints and Their Application to WhiteWine Clustering and Discrimination.

Publicado en línea: 07 Mar 2018
Páginas: 24 - 34

Resumen

Abstract

This study continues the attempt to use the statistical process for a large-scale analytical data. A group of 3898 white wines, each with 11 analytical laboratory benchmarks was analyzed by a fingerprint similarity search in order to be grouped into separate clusters. A characterization of the wine’s quality in each individual cluster was carried out according to individual laboratory parameters.

Palabras clave

  • similarity search
  • descriptor fingerprints
  • white wine clustering
Acceso abierto

SpectraView 1.0 – 2D visualization of stellar spectra

Publicado en línea: 07 Mar 2018
Páginas: 35 - 39

Resumen

Abstract

This article presents a 2D visualization of stellar spectra, obtained in Rozhen NAO.The aim is to convert one-dimensional arrays into two-dimensional images with the possibility of adjusting the degree of gray. This allows us to visualize the curves of the radial velocities and to determine their half-amplitudes even more precisely. The results of the observed stars NSVS 254037 and TYC3621-711 are presented.

Palabras clave

  • Variable stars
  • Spectra
  • Programs
Acceso abierto

Quality assurance of Mo-99/Tc-99m radionuclide generators

Publicado en línea: 07 Mar 2018
Páginas: 40 - 47

Resumen

Abstract

Gamma-ray spectrometry analyses of the radionuclide content of eluate from two Mo-99/Tc-99m radionuclide generators POLTECHNET have been performed. The relative activities of 99Mo 103Ru and 131I radioisotopes with respect to the activity of 99mTc at different time intervals after the primary pertechnetate elution of the generators have been analyzed. The relative activities of the isotopes were determined and compared to the radionuclidic purity requirements for 99mTc.

Palabras clave

  • quality assurance
  • technetium generator
  • gamma-ray spectroscopy
  • nuclear medicine
Acceso abierto

The acceptors behavior in the Single and Double Doped Bi12TiO20

Publicado en línea: 07 Mar 2018
Páginas: 48 - 53

Resumen

Abstract

The absorption coefficient of Bi12TiO20:AlI, Bi12TiO20:AlII, Bi12SiO20:P and Bi12SiO20:Al+P single crystals is measured in the spectral region of Urbach’s rule (1.52 – 2.92 eV) at room temperature. The parameters of electron-phonon interaction, Urbach’s energy and the constants of Urbach’s rule are calculated. The behavior of the acceptors Al3+ and P5+ in Urbach’s rule region has been considered.

Palabras clave

  • doped sillenites
  • Urbach’s rule
  • electron-phonon interaction
  • Urbach’s energy
Acceso abierto

First bioacoustic and morphological data for the presence of Pelophylax bedriagae in Bulgaria

Publicado en línea: 07 Mar 2018
Páginas: 54 - 63

Resumen

Abstract

Water frog mating calls from two localities were studied and analyzed. Recordings were made in the summer of 2010 at the Arkutino swamp near the town of Primorsko and at the Vurbitza River near the town of Momchilgrad. A total of 154 calls were analyzed and the results suggested the presence of both the Marsh frog (Pelophylax ridibundus) and the Levant frog (Pelophylax bedriagae) in both sites, with the former being more frequent in Vurbitza River, and the latter – in Arkutino. At Vurbitza, we also captured and measured 2 specimens, which morphological characteristics differed from P. ridibundus and matched those of P. bedriagae. These are the first localities for P. bedriagae in Bulgaria.

Palabras clave

  • distribution
  • Levant frog
  • locality
  • mating call
  • measurements
Acceso abierto

In vitro cytotoxicity of allelopathic plants Adonis vernalis L. Origanum vulgare ssp. vulgare L. and Nepeta nuda subsp. nuda

Publicado en línea: 07 Mar 2018
Páginas: 64 - 69

Resumen

Abstract

Medicinal plants produce various secondary metabolites as a part of their chemical defence and survival in nature. These compounds have a wide range of biological activities. Nowadays, medicinal plants are used as source of allelochemicals and new effective anticancer agents. Our previous studies revealed allelopathic potential of water extracts of Adonis vernalis L. (Ranunculaceae), Origanum vulgare ssp. vulgare L. and Nepeta nuda subsp. nuda (Lamiaceae). Present study aimed to evaluate the effect of the same extracts in vitro on human hepatoma cell line SK-HEP-1. Cell proliferation/viability was assessed using Premixed WST-1 Cell Proliferation Reagent.

Adonis water extract (1.83mg/ml) had notable negative influence on cancer cell line tested. Oregano (3.5 mg/ml) also exerted negative effect, but to a lesser degree. On the contrary, nepeta water extract (6.59 mg/ml) had an opposite effect, stimulating cell proliferation. One possible explanation could be the type of extraction: after treatment with nepeta methanol extract (6.59 mg/ml) cell viability was significantly reduced.

In conclusion, Adonis vernalis and Nepeta nuda subsp. nuda possess metabolites with growth inhibitory effect on human hepatoma cell line SK-HEP-1. Further research is needed to clarify biological activity of lower concentrations which are appropriate to enable the design of new anticancer drugs.

Palabras clave

  • water extracts
  • human hepatomacell line SK-HEP-1
  • Adonis vernalis L. (Ranunculaceae)
  • Origanum vulgare ssp. vulgare L. and Nepeta nuda subsp. nuda (Lamiaceae)
Acceso abierto

Notes on the hatching phases and the size of the juveniles in the Snake-eyed skink Ablepharus kitaibelii (Bibron & Bory de Saint-Vincent, 1833)

Publicado en línea: 07 Mar 2018
Páginas: 69 - 74

Resumen

Abstract

Most of the studies dealing with the Snake-eyed skink (Ablepharus kitaibelii) treat predominantly aspects of the distribution and taxonomy of the species. In the present study we provide information concerning the mechanism of hatching in the Snake-eyed skink and the dimensions of the hatched specimens. We collected data from wild animals, as well as from indoor incubated juveniles. The present study provides the first data concerning the weight of the newly hatched juveniles of the species and discuss on potential misleading data concerning the size of the juveniles in A. kitaibelii.

Palabras clave

  • egg shell rupture
  • lizard
  • morphometrics
Acceso abierto

Size does matter – Intraspecific variation of feeding mechanics in the crested newt Triturus dobrogicus (Kiritzescu, 1903)

Publicado en línea: 07 Mar 2018
Páginas: 75 - 85

Resumen

Abstract

Many studies have yet been conducted on suction feeding in aquatic salamander species. Within the Salamandridae, the crested newt Triturus dobrogicus (Kiritzescu, 1903), occurring from the Austrian Danube floodplains to the Danube Delta, was not subject of investigations so far. The present study examines the kinematics of aquatic suction feeding in this species by means of high-speed videography. Recordings of five individuals of different size and sex while feeding on bloodworms were conducted, in order to identify potential discrepancies among individuals and sizes. Five coordinate points were digitized from recordings of prey capture and twelve time- and velocity-determined variables were evaluated. All specimens follow a typical inertial suction feeding process, where rapid hyoid depression expands the buccal cavity. Generated negative pressure within the buccal cavity causes influx of water along with the prey item into the mouth. Results demonstrate higher distance values and angles for gape in individuals with smaller size. In addition, hyoid depression is maximized in smaller individuals. While Triturus dobrogicus resembles a typical inertial suction feeder in its functional morphology, intraspecific differences could be found regarding the correlation of different feeding patterns and body size.

Palabras clave

  • Amphibians
  • Salamandridae
  • Triturus
  • suction feeding
  • intraspecific variation
Acceso abierto

Seasonal activity of Leptoiulus trilineatus (C.L. Koch, 1847) and Megaphyllum trassylvanicum (Verhoeff, 1897) (Diplopoda: Julida: Julidae)

Publicado en línea: 07 Mar 2018
Páginas: 86 - 94

Resumen

Abstract

The article presents the results of a study of the soil surface seasonal activity of two species of julidae, widely spread in the Balkan Peninsula: Leptoiulus trilineatus (C.L. Koch, 1847) and Megaphyllum trassylvanicum (Verhoeff, 1897). The material was collected by means of pitfall traps between May 2007 and May 2009 in natural and urban habitats exposed to varying degrees of anthropogenic pressure. In the study period 1474 specimens of L. trilineatus and 618 specimens of M. transsylvanicum were collected. The impact of the soil and air temperature and humidity on the seasonal activity of both species was measured through statistical analysis. The statistical data processing was conducted using SPSS 9.0 and StatPlus 3.5.3 software packages.

L. trilineatus and M. trassylvanicum are polytopic, mesophilic and mesotermic species with year-round activity in the studied area. There is no statistically significant correlation between the degree of anthropogenic impact and the activity of the two species.

Leptoiulus trilineatus shows equal preference for both urban and natural habitats in the studied area. The species demonstrates the typical of all millipedes bimodal activity, which is the highest in spring and the beginning of winter – in the periods from March to May and from November to December. The coefficients of correlation dependence of L. trilineatus activity on the tested abiotic environmental factors are not statistically significant. The Pearson-Brave coefficient which measures the effect of soil humidity on species activity is 0.417, which shows a positive correlation. M. trassylvanicum has the highest frequency in urban biotops such as parks in the urban and suburban areas of Shumen and in the coniferous habitats on the Shumen Plateau. In this area the species demonstrates its highest activity in spring and summer (from February to July). The abiotic factors with statistically significant effect on the soil surface activity of M. trassylvanicum are the soil and air temperature – the values of the Pearson-Brave correlation coefficients are 0.708 and 0.586 respectively.

Palabras clave

  • Diplopoda
  • seasonal activity
  • analysis of variance
Acceso abierto

Potentially dangerous 24-hour rainfall in the Provadiyska vally system at the end of the 20th and early 21st Centuries

Publicado en línea: 07 Mar 2018
Páginas: 96 - 101

Resumen

Abstract

Extreme rainfalls are of paramount importance for the formation of river springs and, consequently, the occurrence of spills and floods. The article presents the results of a case study of the potentially dangerous 24-hour eruptions in the Provadiyska valley system from the end of the 20th and the beginning of the 21st century. Particular attention is paid to the morphometric parameters and the configuration of the river-valley supply network of the Provadiyska river. On this basis, there are defined areas in which there are favorable conditions for forming high river waves.

Palabras clave

  • risk
  • factors
  • precipitation
  • catchment
  • Provadiyska River
  • floods
  • prevention
Acceso abierto

The West Black Sea passive continental margin in the east part of Balkan Peninsula

Publicado en línea: 07 Mar 2018
Páginas: 102 - 107

Resumen

Abstract

The Black Sea Neozoic passive continental margin marks the natural „bridge” between the Moesian and Bulgarian continental microplates and the Black Sea oceanic microplatte. It was coming in to being after the saturation between the terrains which are composed the Neo Europe south east part during the Early Paleogene. The subaerial part of the margin includes the most east parts of the South Moesian, Hemus, and Upper Thracian and Sakar-Strandzha morphostructural zones. The subaquatic part of the margin is composed by the consequently orderly step lower to the Black Sea bottom: high shelf zone, lover shelf zone, continental slope and continental foot. The Black Sea Neozoic passive continental margin is characterized by low seismic activity. It is concentrated in some fault zones.

Palabras clave

  • passive continental margin
  • morphostructure
  • morphotectonic evolution
  • seismic activity
14 Artículos
Acceso abierto

Editorial Note: Where Science Meets Art (II)

Publicado en línea: 07 Mar 2018
Páginas: 4 - 5

Resumen

Acceso abierto

Thermodynamic model for solution behavior and solid-liquid equilibrium in Na-Al(III)-Fe(III)-Cr(III)-Cl-H2O system at 25°C

Publicado en línea: 07 Mar 2018
Páginas: 6 - 16

Resumen

Abstract

The knowledge of the thermodynamic behavior of multicomponent aqueous electrolyte systems is of main interest in geo-, and environmental-sciences. The main objective of this study is the development of a high accuracy thermodynamic model for solution behavior, and highly soluble M(III)Cl3(s) (M= Al, Fe, Cr) minerals solubility in Na-Al(III)-Cr(III)-Fe(III)-Cl-H2O system at 25°C. Comprehensive thermodynamic models that accurately predict aluminium, chromium and iron aqueous chemistry and M(III) mineral solubilities as a function of pH, solution composition and concentration are critical for understanding many important geochemical and environmental processes involving these metals (e.g., mineral dissolution/alteration, rock formation, changes in rock permeability and fluid flow, soil formation, mass transport, toxic M(III) remediation). Such a model would also have many industrial applications (e.g., aluminium, chromium and iron production, and their corrosion, solve scaling problems in geothermal energy and oil production). Comparisons of solubility and activity calculations with the experimental data in binary and ternary systems indicate that model predictions are within the uncertainty of the data. Limitations of the model due to data insufficiencies are discussed. The solubility modeling approach, implemented to the Pitzer specific interaction equations is employed. The resulting parameterization was developed for the geochemical Pitzer formalism based PHREEQC database.

Acceso abierto

Allenephosphonic phosphine oxides in reactions with electrophilic reagents

Publicado en línea: 07 Mar 2018
Páginas: 17 - 23

Resumen

Abstract

The reactivity of the titled compounds towards electrophilic reagents has been investigated and new experimental evidences for the mechanism of the electrophilic addition reactions to 1,2-alkadienephosphonates have been reported

Palabras clave

  • electrophilic addition
  • nucleophilic addition
  • 1,2-alkadienephosphonates
Acceso abierto

Descriptor Fingerprints and Their Application to WhiteWine Clustering and Discrimination.

Publicado en línea: 07 Mar 2018
Páginas: 24 - 34

Resumen

Abstract

This study continues the attempt to use the statistical process for a large-scale analytical data. A group of 3898 white wines, each with 11 analytical laboratory benchmarks was analyzed by a fingerprint similarity search in order to be grouped into separate clusters. A characterization of the wine’s quality in each individual cluster was carried out according to individual laboratory parameters.

Palabras clave

  • similarity search
  • descriptor fingerprints
  • white wine clustering
Acceso abierto

SpectraView 1.0 – 2D visualization of stellar spectra

Publicado en línea: 07 Mar 2018
Páginas: 35 - 39

Resumen

Abstract

This article presents a 2D visualization of stellar spectra, obtained in Rozhen NAO.The aim is to convert one-dimensional arrays into two-dimensional images with the possibility of adjusting the degree of gray. This allows us to visualize the curves of the radial velocities and to determine their half-amplitudes even more precisely. The results of the observed stars NSVS 254037 and TYC3621-711 are presented.

Palabras clave

  • Variable stars
  • Spectra
  • Programs
Acceso abierto

Quality assurance of Mo-99/Tc-99m radionuclide generators

Publicado en línea: 07 Mar 2018
Páginas: 40 - 47

Resumen

Abstract

Gamma-ray spectrometry analyses of the radionuclide content of eluate from two Mo-99/Tc-99m radionuclide generators POLTECHNET have been performed. The relative activities of 99Mo 103Ru and 131I radioisotopes with respect to the activity of 99mTc at different time intervals after the primary pertechnetate elution of the generators have been analyzed. The relative activities of the isotopes were determined and compared to the radionuclidic purity requirements for 99mTc.

Palabras clave

  • quality assurance
  • technetium generator
  • gamma-ray spectroscopy
  • nuclear medicine
Acceso abierto

The acceptors behavior in the Single and Double Doped Bi12TiO20

Publicado en línea: 07 Mar 2018
Páginas: 48 - 53

Resumen

Abstract

The absorption coefficient of Bi12TiO20:AlI, Bi12TiO20:AlII, Bi12SiO20:P and Bi12SiO20:Al+P single crystals is measured in the spectral region of Urbach’s rule (1.52 – 2.92 eV) at room temperature. The parameters of electron-phonon interaction, Urbach’s energy and the constants of Urbach’s rule are calculated. The behavior of the acceptors Al3+ and P5+ in Urbach’s rule region has been considered.

Palabras clave

  • doped sillenites
  • Urbach’s rule
  • electron-phonon interaction
  • Urbach’s energy
Acceso abierto

First bioacoustic and morphological data for the presence of Pelophylax bedriagae in Bulgaria

Publicado en línea: 07 Mar 2018
Páginas: 54 - 63

Resumen

Abstract

Water frog mating calls from two localities were studied and analyzed. Recordings were made in the summer of 2010 at the Arkutino swamp near the town of Primorsko and at the Vurbitza River near the town of Momchilgrad. A total of 154 calls were analyzed and the results suggested the presence of both the Marsh frog (Pelophylax ridibundus) and the Levant frog (Pelophylax bedriagae) in both sites, with the former being more frequent in Vurbitza River, and the latter – in Arkutino. At Vurbitza, we also captured and measured 2 specimens, which morphological characteristics differed from P. ridibundus and matched those of P. bedriagae. These are the first localities for P. bedriagae in Bulgaria.

Palabras clave

  • distribution
  • Levant frog
  • locality
  • mating call
  • measurements
Acceso abierto

In vitro cytotoxicity of allelopathic plants Adonis vernalis L. Origanum vulgare ssp. vulgare L. and Nepeta nuda subsp. nuda

Publicado en línea: 07 Mar 2018
Páginas: 64 - 69

Resumen

Abstract

Medicinal plants produce various secondary metabolites as a part of their chemical defence and survival in nature. These compounds have a wide range of biological activities. Nowadays, medicinal plants are used as source of allelochemicals and new effective anticancer agents. Our previous studies revealed allelopathic potential of water extracts of Adonis vernalis L. (Ranunculaceae), Origanum vulgare ssp. vulgare L. and Nepeta nuda subsp. nuda (Lamiaceae). Present study aimed to evaluate the effect of the same extracts in vitro on human hepatoma cell line SK-HEP-1. Cell proliferation/viability was assessed using Premixed WST-1 Cell Proliferation Reagent.

Adonis water extract (1.83mg/ml) had notable negative influence on cancer cell line tested. Oregano (3.5 mg/ml) also exerted negative effect, but to a lesser degree. On the contrary, nepeta water extract (6.59 mg/ml) had an opposite effect, stimulating cell proliferation. One possible explanation could be the type of extraction: after treatment with nepeta methanol extract (6.59 mg/ml) cell viability was significantly reduced.

In conclusion, Adonis vernalis and Nepeta nuda subsp. nuda possess metabolites with growth inhibitory effect on human hepatoma cell line SK-HEP-1. Further research is needed to clarify biological activity of lower concentrations which are appropriate to enable the design of new anticancer drugs.

Palabras clave

  • water extracts
  • human hepatomacell line SK-HEP-1
  • Adonis vernalis L. (Ranunculaceae)
  • Origanum vulgare ssp. vulgare L. and Nepeta nuda subsp. nuda (Lamiaceae)
Acceso abierto

Notes on the hatching phases and the size of the juveniles in the Snake-eyed skink Ablepharus kitaibelii (Bibron & Bory de Saint-Vincent, 1833)

Publicado en línea: 07 Mar 2018
Páginas: 69 - 74

Resumen

Abstract

Most of the studies dealing with the Snake-eyed skink (Ablepharus kitaibelii) treat predominantly aspects of the distribution and taxonomy of the species. In the present study we provide information concerning the mechanism of hatching in the Snake-eyed skink and the dimensions of the hatched specimens. We collected data from wild animals, as well as from indoor incubated juveniles. The present study provides the first data concerning the weight of the newly hatched juveniles of the species and discuss on potential misleading data concerning the size of the juveniles in A. kitaibelii.

Palabras clave

  • egg shell rupture
  • lizard
  • morphometrics
Acceso abierto

Size does matter – Intraspecific variation of feeding mechanics in the crested newt Triturus dobrogicus (Kiritzescu, 1903)

Publicado en línea: 07 Mar 2018
Páginas: 75 - 85

Resumen

Abstract

Many studies have yet been conducted on suction feeding in aquatic salamander species. Within the Salamandridae, the crested newt Triturus dobrogicus (Kiritzescu, 1903), occurring from the Austrian Danube floodplains to the Danube Delta, was not subject of investigations so far. The present study examines the kinematics of aquatic suction feeding in this species by means of high-speed videography. Recordings of five individuals of different size and sex while feeding on bloodworms were conducted, in order to identify potential discrepancies among individuals and sizes. Five coordinate points were digitized from recordings of prey capture and twelve time- and velocity-determined variables were evaluated. All specimens follow a typical inertial suction feeding process, where rapid hyoid depression expands the buccal cavity. Generated negative pressure within the buccal cavity causes influx of water along with the prey item into the mouth. Results demonstrate higher distance values and angles for gape in individuals with smaller size. In addition, hyoid depression is maximized in smaller individuals. While Triturus dobrogicus resembles a typical inertial suction feeder in its functional morphology, intraspecific differences could be found regarding the correlation of different feeding patterns and body size.

Palabras clave

  • Amphibians
  • Salamandridae
  • Triturus
  • suction feeding
  • intraspecific variation
Acceso abierto

Seasonal activity of Leptoiulus trilineatus (C.L. Koch, 1847) and Megaphyllum trassylvanicum (Verhoeff, 1897) (Diplopoda: Julida: Julidae)

Publicado en línea: 07 Mar 2018
Páginas: 86 - 94

Resumen

Abstract

The article presents the results of a study of the soil surface seasonal activity of two species of julidae, widely spread in the Balkan Peninsula: Leptoiulus trilineatus (C.L. Koch, 1847) and Megaphyllum trassylvanicum (Verhoeff, 1897). The material was collected by means of pitfall traps between May 2007 and May 2009 in natural and urban habitats exposed to varying degrees of anthropogenic pressure. In the study period 1474 specimens of L. trilineatus and 618 specimens of M. transsylvanicum were collected. The impact of the soil and air temperature and humidity on the seasonal activity of both species was measured through statistical analysis. The statistical data processing was conducted using SPSS 9.0 and StatPlus 3.5.3 software packages.

L. trilineatus and M. trassylvanicum are polytopic, mesophilic and mesotermic species with year-round activity in the studied area. There is no statistically significant correlation between the degree of anthropogenic impact and the activity of the two species.

Leptoiulus trilineatus shows equal preference for both urban and natural habitats in the studied area. The species demonstrates the typical of all millipedes bimodal activity, which is the highest in spring and the beginning of winter – in the periods from March to May and from November to December. The coefficients of correlation dependence of L. trilineatus activity on the tested abiotic environmental factors are not statistically significant. The Pearson-Brave coefficient which measures the effect of soil humidity on species activity is 0.417, which shows a positive correlation. M. trassylvanicum has the highest frequency in urban biotops such as parks in the urban and suburban areas of Shumen and in the coniferous habitats on the Shumen Plateau. In this area the species demonstrates its highest activity in spring and summer (from February to July). The abiotic factors with statistically significant effect on the soil surface activity of M. trassylvanicum are the soil and air temperature – the values of the Pearson-Brave correlation coefficients are 0.708 and 0.586 respectively.

Palabras clave

  • Diplopoda
  • seasonal activity
  • analysis of variance
Acceso abierto

Potentially dangerous 24-hour rainfall in the Provadiyska vally system at the end of the 20th and early 21st Centuries

Publicado en línea: 07 Mar 2018
Páginas: 96 - 101

Resumen

Abstract

Extreme rainfalls are of paramount importance for the formation of river springs and, consequently, the occurrence of spills and floods. The article presents the results of a case study of the potentially dangerous 24-hour eruptions in the Provadiyska valley system from the end of the 20th and the beginning of the 21st century. Particular attention is paid to the morphometric parameters and the configuration of the river-valley supply network of the Provadiyska river. On this basis, there are defined areas in which there are favorable conditions for forming high river waves.

Palabras clave

  • risk
  • factors
  • precipitation
  • catchment
  • Provadiyska River
  • floods
  • prevention
Acceso abierto

The West Black Sea passive continental margin in the east part of Balkan Peninsula

Publicado en línea: 07 Mar 2018
Páginas: 102 - 107

Resumen

Abstract

The Black Sea Neozoic passive continental margin marks the natural „bridge” between the Moesian and Bulgarian continental microplates and the Black Sea oceanic microplatte. It was coming in to being after the saturation between the terrains which are composed the Neo Europe south east part during the Early Paleogene. The subaerial part of the margin includes the most east parts of the South Moesian, Hemus, and Upper Thracian and Sakar-Strandzha morphostructural zones. The subaquatic part of the margin is composed by the consequently orderly step lower to the Black Sea bottom: high shelf zone, lover shelf zone, continental slope and continental foot. The Black Sea Neozoic passive continental margin is characterized by low seismic activity. It is concentrated in some fault zones.

Palabras clave

  • passive continental margin
  • morphostructure
  • morphotectonic evolution
  • seismic activity

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