Shapes and rotational properties of thirty asteroids from photometric data

We have analyzed photometric lightcurves of 30 asteroids, and present here the obtained shapes, rotational periods and pole directions. We also present new photometric observations of five asteroids. The shape models indicate the existence of many features of varying degrees of irregularity. Even large main-belt asteroids display such features, so the resulting poles and periods are more consistent than those obtained by simple ellipsoid-like models. In some cases the new rotational parameters are rather different from those obtained previously, and in a few cases there were no proper previous estimates at all.     

Simulation of oceanic volume transports through Fram Strait 1995–2005

We discuss the model representation of volume transports through one of the most climate-relevant ocean passages, the Fram Strait. We compare results from a coupled ocean–sea ice model with different resolutions (∼1/12° and ∼1/4°) and measurements from a mooring array along 79° N. The 1/4° model delivers a realistic mean climate state and realistic net volume transports. However, this model fails to reproduce the observed intense barotropic recirculation that reaches far north in Fram Strait. This recirculation is captured in the higher resolution version of the model. Other differences exist in the circulation over the East Greenland Shelf and in the temperature of Atlantic waters in the Fram Strait region as well as in surface heat fluxes. We find that a combination of high-resolution model results and long-term measurements can improve the interpretation of measured and simulated processes and reduce the uncertainties in exchange rates between Arctic and the North Atlantic.     

Bedform characteristics in natural and regulated channels: A comparative field study on the Wilga River,Poland

This paper presents results of a field investigation conducted to examine the bed sediment, riverbed morphology and flow structure over dunes in natural and regulated channels. Field measurements using an acoustic Doppler current profiler (ADCP) have been carried out on two parts of lowland Wilga River in Poland. It is shown that the bedforms with a low angle of lee side develop more frequently than asymmetrical dunes with high lee-side angles, which are mostly associated with the occurrence of local scours and river meanders. Wavenumber analysis of bed elevation confirms the existence of scaling region in the longitudinal wavenumber spectrum, with “?3” scaling exponents for the natural and regulated channels as well. Moreover, the results of flow velocity field are presented in the form of a 2-D streamwise-vertical vector field, showing several similarities to previous laboratory and field investigations conducted on much deeper rivers than the Wilga. The experimental campaign and methods used to obtain the results are also presented briefly. In addition, a short database of fluvial dunes statistics is provided.     

Chemical and isotopic variations in the Wiśniówka Mała mine pit water,Holy Cross Mountains (south-central Poland)

In 2005 and 2006, hydrogeochemical study was carried out in the bipartite Wiśniówka Mała pit lake of the Holy Cross Mountains (south-central Poland). This is the largest acidic water body in Poland. This report presents the element concentrations in the water and sediment, stable sulfur and oxygen isotope ratios in the soluble sulfates, and stable oxygen isotope ratio in the water. The scope of the investigation also encompassed mineralogical examinations (scanning electron microscope, X-ray diffraction) of the sediment. The results of this study show that there is a spatial and temporal variability in concentrations of most elements and sulfur isotope ratios in the examined pit lake. The water of the western pond displayed a lower pH with a mean of 3.73 and higher conductivity (390 μS cm⁻¹) as well as higher concentrations of sulfates (156 mg L⁻¹) and most of the cations and anions. The concentrations of Fe²⁺ and Fe³⁺ averaged 0.8 and 0.4 mg·L⁻¹. In contrast, the eastern pond water revealed a higher pH (mean of 4.36), lower conductivity (293 μS cm⁻¹) and lower sulfate (90 mg L⁻¹) and trace metal levels. Similar variations were recorded in the stable sulfur isotope ratios. The δ³⁴S_V-CDT(SO₄ ²⁻) values in the water of the western pit pond were in the range of −6.7 to −4.6‰ (mean of −5.6‰), whereas that in the eastern pit pond ranged from −2.2 to −0.9‰ (−1.6‰). The alkalinity of the entire lake water was below 0.1 mg·L⁻¹ CaCO₃. No distinct difference in the δ¹⁸O_V-SMOW(SO₄ ²⁻) was noted between the western and eastern pit ponds. Compared to the Purple Pond in the Sudetes (Poland) and similar sites throughout the world, the examined pit lake is highlighted by distinctly low concentrations of sulfates, iron and other trace metals. Based on this and other studies performed in the Holy Cross Mountains, a conclusion can be drawn that the SO₄ ²⁻ in the Wiśniówka Mała pit lake water is a mixture of SO₄ ²⁻ derived from the following sources: (1) pyrite oxidation (especially in the western pond water), (2) leaching of soluble sulfates from soils and waste material, as well as (3) subordinate deposition of airborne sulfate precipitation.     

Do mowing regimes affect plant and soil biological activity in the mountain meadows of Southern Poland?

The soil biological activity of mountain meadows is a significant factor that determines the health and utility of these regions. The climax stage of this area is forest, but to maintain semi-natural grassland, which is characterised by high biodiversity,low-intensity land use(mowing or grazing) is necessarily required. To understand the effect of various mowing regimes on the soil biological activity and plants, the soil microbial activity(microbial biomass carbon, dehydrogenase activity and number of the cultivable fraction of soil microbial community),annelids community(density and species composition earthworms and enchytraeids) and plant species composition were investigated. The study area was located in the Pieniny National Park in the Carpathian Mountains, in a meadow belonging to the association Dactylis glomerata-Poa trivialis. The investigated variants were divided according to mowing regime:traditional scything – hand mowing(HM), mechanical mowing(MM), or the abandonment of mowing – nonmowing(NM). The microbial activities(expressed by,e.g. microbial biomass carbon and the number of phosphorus bacteria) were affected by the mowing regime. The density of earthworms was higher in the HM and MM than in the NM variants. The largest changes in plant species composition were caused by the abandonment of mowing(NM). The mean number of plant species was positively correlated with soil moisture, earthworm density, and microbial activity(expressed indirectly by dehydrogenases activity). The soil microbial community, such as vegetative bacteria forms and ammonifying bacteria,were positively associated with pH value, and the microbial and total organic carbon content. The results presented here indicate that there is no single form of optimal management for all living organisms.Decisions about mowing regimes, or abandonment of use, should be preceded by multi-aspect studies,including plants and soil biota.     

The Shilu Iron Ore Deposit in Hainan Province,South China: A Structurally and Hydrothermally Reworked and Re-Enriched Lake-Superior-Type BIF Iron Deposit

The Shilu iron ore deposit, located in the western Hainan Province, South China, is one of the most important iron-ore mining districts in China not only for its huge reserves of hematite- rich ores, but also for its potentially economic significance of associated metals of copper, cobalt, nickel, silver, lead and zinc, and of non-metals of dolomite, quartzite,barite,gypsum and sulfur.     

Effects of coal storage in air on physical and chemical properties of coal and on gas adsorption

This paper investigates changes in the high-volatile bituminous Lower Block Coal Member from Indiana owing to moisture availability and oxidation in air at ambient pressure and temperature over storage time. Specifically, it investigates changes in chemistry, in surface area, and pore structure, as well as changes in methane and carbon dioxide adsorption capacities. Our results document that the methane adsorption capacity increased by 40%, whereas CO₂ adsorption capacity increased by 18% during a 13-month time period. These changes in adsorption are accompanied by changes in chemistry and surface area of the coal.The observed changes in adsorption capacity indicate that special care must be taken when collecting samples and preserving coals until adsorption characteristics are measured in the laboratory. High-pressure isotherms from partially dried coal samples would likely cause overestimation of gas adsorption capacities, lead to a miscalculation of coal-bed methane prospects, and provide deceptively optimistic prognoses for recovery of coal-bed methane or capture of anthropogenic CO₂.