Radio-continuum study of MCSNR J0536–7038 (DEM L249)

We present a detailed radio-continuum study on Australia Telescope Compact Array (ATCA) observations of Large Magellanic Cloud (LMC) supernova remnant (SNR), MCSNR J0536–7038. This Type Ia SNR follows a horseshoe morphology, with a size 32 pc × 32 pc (1-pc uncertainty in each direction). It exhibits a radio spectrum α=?0.52±0.07 between λ=73 and 6 cm. We report detections of regions showing moderately high fractional polarisation at 6 cm, with a peak value of 71±25 % and a mean fractional polarisation of 35±8 %. We also estimate an average rotation measure across the remnant of –237 rad m^?2. The intrinsic magnetic field appears to be uniformly distributed, extending in the direction of the two brightened limbs of the remnant.     

Draconids 2011: Outburst Observations by the Croatian Meteor Network

The predicted Draconid meteor shower outburst during October 2011 had been observed by a portion of the Croatian Meteor Network whose stations encountered clear weather. A total of 95 Draconid orbits have been calculated from 18 contributing stations, and in this paper we present results for 63 orbits obtained from the fully automatic observation and processing pipeline. Two methods of trajectory estimation were applied, showing better fit results using a linearly changing velocity model versus a constant velocity model. The estimated mean radiant position has been found to be at RA = 262.6°, Dec = +55.7°, with estimated geocentric velocity Vg = 20.7 km/s.     

On the origin of Triton

On dynamical grounds Neptune's satellite Triton is believed to be a captured body. We present nondynamical arguments in favour of this idea.     

Does physics exhibit its negation?

In this Letter we give a brief sketch of the problem of scientific knowledge as it has been elaborated by Pauli and Jung on a non-physical ground. In addition, we try to find arguments in favour of their opinion in the territory of physics. If these reasons hold indeed, then an incompatibility in space-time-matter relationship can be indicated.     

Mineralgänge von Crni Kamen bei dem Dorfe Alinci in Mazedonien

Zusammenfassung In Alkalisyeniten des Gipfels Crni Kamen, sw. von Prilep in Mazedonien, kommen hydrothermale Gänge mit schön kristallisierten Mineralen vor. Nebst kurz erwähnten, spärlich vorkommenden Sulfiden werden die Resultate der Untersuchungen des Alkaliamphibols, Mikroklins, Apatits Albits, Sphens, Quarzes und Hyalits gegeben. In diesem Gebiet wurden auch Davidit, Brannerit, Ilmenit und Magnetit gefunden. Selten findet sich regelmäßige Verwachsung des Ilmenits mit Rutil.

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Summary In alkali syenites on the hill Crni Kamen, sw. from Prilep in Macedonia hydrothermal veins appear with well crystallized minerals. In addition to the briefly described scarcely appeared sulfides the results of the investigations of alkaliamphibole, microcline, apatite, albite, sphene, quartz and hyalite are reported. In this area were also recorded davidite, brannerite, ilmenite and magnetite. Oriented growth of ilmenite with rutile has been rarely found.

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Mit 1 Textabbildung

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Herrn Professor Dr.F. Machatschki zum 70. Geburtstag gewidmet.     

An analysis of naturally occurring radionuclides and <Superscript>137</Superscript>Cs in the soils of urban areas using gamma-ray spectrometry

This study of environmental radioactivity was carried out in the soils of an urban area. Naturally occurring gamma-emitting radionuclides and man-made ¹³⁷Cs were found in the soil profiles collected from four parks in the central Belgrade city area and the soil layer was examined every 10 cm and to a depth of 50 cm. Radioisotope activity concentrations (Bq kg^?1) in the samples of urban soil using the gamma-ray spectrometry method were in the range of 14–46 for ²³⁸U, 33–50 for ²²⁶Ra, 29–63 for ²¹⁰Pb, 1.2–3.4 for ²³⁵U, 28–50 for ²³²Th, 424–576 for ⁴⁰K and 0.7–35.8 for ¹³⁷Cs. Some of the basic physicochemical soil properties (pH, organic matter content, calcium-carbonate content, particle size distribution) were determined to investigate the impact on the vertical distribution of radionuclides. The results of this investigation showed that variations of activity concentration ratios of radionuclides that belong to the same (²³⁸U/²²⁶Ra) or different radioactive series (²³²Th/²²⁶Ra; ²³⁵U/²³⁸U), including ²¹⁰Pb/¹³⁷Cs ratios could well be explained by the properties of the soil. Alkaline pH reaction, the accumulation of organic matter in the uppermost and of carbonates in the deepest layers of urban soil had an effect on ²³⁸U/²²⁶Ra, and ²¹⁰Pb/¹³⁷Cs activity concentration ratio values, while ²³²Th/²²⁶Ra and partially ²³⁵U/²³⁸U ratios were associated with the particle sizes vertical distribution. A study of radionuclides in the samples of leaves of two deciduous tree species common for these parks was also conducted and ²¹⁰Pb and ⁴⁰K were found concentrated in leaves rather than other investigated radionuclides.     

Loop Quantum Cosmology and Probability of Inflation

We study the measure on the set of initial conditions in remote past for Loop Quantum Cosmology with massive scalar field motivated by various choices of the measure present in the literature. The main finding of the paper is existence of an attractor at contracting phase of the universe, which, in addition to the well known attractor at expanding phase, predicts a very specific duration of inflationary stage with the number of e-foldings about 140.     

Magnetic,geochemical and mineralogical properties of sediments from karstic and flysch rivers of Croatia and Slovenia

The aim of the present work was to investigate links between the low-field magnetic susceptibility (MS) and chemical and mineral composition of sediments from several Croatian and Slovenian rivers, as well as to determine possible anthropogenic influence on these sediments. MS measurements are a fast and simple method, which serves as a proxy for the estimation of pollution in different environmental systems. The investigated rivers are predominantly unpolluted rivers from Croatian and Slovenian karstic and flysch areas, which belong to the Adriatic or the Black Sea watersheds: the Dragonja, the Mirna, the Ra?a, the Ri?ana, the Reka, the Rak, the Cerkni?nica, the Unec and the Ljubljanica rivers. It was assumed that, due to their mostly unpolluted status, they could serve as a database for natural MS background values for this region. For comparison, several rivers and a lake from the Celje old metallurgic industrial area (Slovenia) were also investigated: the Savinja, the Hudinja, the Voglajna rivers and Slivni?ko Lake. They form a sub-basin of the Sava River drainage basin. Sediments of the clean karstic and flysch rivers showed extremely low MS values, with mass susceptibility values ranging from 0.58 × 10^?7 to 5.11 × 10^?7 m³/kg, and isothermal remanent magnetism (IRM) values ranging from 0.71 to 7.88 A/m. In the Celje industrial area, river sediments showed much higher MS values, with mass susceptibility values ranging from 1.31 × 10^?7 to 38.3 × 10^?7 m³/kg, and IRM values ranging from 0.91 to 100.42 A/m. The highest MS value was found in the Voglajna River at Teharje-?tore, a point which showed a significant number of anomalies of toxic metals in earlier investigations. Semiquantitative determination of relations between grain size and concentration of magnetite was performed using the Thompson-Oldfield method. X-ray diffraction (XRD) mineralogical analysis showed that sediments of the Celje area have mostly quartz as major mineral, with relatively small amount of carbonate minerals, while in sediments of karstic rivers carbonate minerals prevail. Statistically significant correlations were obtained between MS and Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Ba in the Slovenian karstic region and between MS and Cr, Fe, Co, Ni and Zn in flysch drainage basins. On the contrary, no correlation of MS and Hg content was obtained.     

Low permeability Neogene lithofacies in Northern Croatia as potential unconventional hydrocarbon reservoirs

We present two examples of describing low permeability Neogene clastic lithofacies to outline unconventional hydrocarbon lithofacies. Both examples were selected from the Drava Depression, the largest macrostructure of the Pannonian Basin System located in Croatia. The first example is the Beni?anci Field, the largest Croatian hydrocarbon reservoir discovered in Badenian coarse-grained clastics that consists mostly of breccia. The definition of low permeability lithofacies is related to the margins of the existing reservoir, where the reservoir lithology changed into a transitional one, which is mainly depicted by the marlitic sandstones. However, calculation of the POS (probability of success of new hydrocarbons) shows critical geological categories where probabilities are lower than those in the viable reservoir with proven reserves. Potential new hydrocarbon volumes are located in the structural margins, along the oil-water contact, with a POS of 9.375%. These potential reserves in those areas can be classified as probable. A second example was the Cremu?ina Structure, where a hydrocarbon reservoir was not proven, but where the entire structure has been transferred onto regional migration pathways. The Lower Pontian lithology is described from well logs as fine-grained sandstones with large sections of silty or marly clastics. As a result, the average porosity is low for conventional reservoir classification (10.57%). However, it is still an interesting case for consideration as a potentially unconventional reservoir, such as the ”tight” sandstones.     

Cold and warm air temperature spells during the winter and summer seasons and their impact on energy consumption in urban areas

The main objective of this study is to determine and analyze cold and warm air temperature spells in the last 6 years (2007–2012) and reveal their impact on electrical energy consumption in a small-sized city such as Sombor (Serbia) with less than 50,000 inhabitants. Hourly air temperature values and electrical energy consumption data have been used as database for all methods. Warm and cold temperature spells (during heat and cold waves) have had the increasing tendencies in the last 6 years and they reflect on additional electrical energy consumption. Detailed analysis showed that higher energy demands occur during workdays and daytime period. Monitoring of the amount of consumed energy showed a clear relationship during the winter cold temperature spells, when electrical energy demand was higher than 0.3 MW. In summer period, the relationship was weaker and consumption was higher than 0.15 MW only when temperature exceeded 30 °C. A small number of air condition devices in houses and companies and mainly one-store buildings with thick walls, which make a good insulation from the outside air temperatures, are probably the main reasons for the above-mentioned results in summer. This paper introduces a new method to resolve the problem of short-term load forecasting, based on the support vector machines (SVM) technology and particle swarm optimization that has been used to optimize the SVM parameters. Similar-day-based forecast has shown that similar days for training should be filtered also using classifier of temperature period (cooling degree-days or heating degree-days in a row). Forecasting error is smaller compared to solutions where similar days are found only on season and temperature.