Horizontal distance from continuously working reference GNSS station influence on the position accuracy

The aim of our thesis was to check the effect of distance from the continuously working\ud GNSS reference station on the accuracy of positioning when using static and kinematic\ud GNSS surveying methods. Field measurements were carried out at six points in the area\ud near Ljubljana and Vrhnika at distances from 5 to 25 kilometres from the GNSS continuously\ud working reference station in Ljubljana. Coordinates of selected points were determined using\ud rapid static and RTK measuring method. In RTK method a virtual reference station VRS\ud created near the worksite and permanent station GSR1 were used as reference stations.\ud When processing the rapid static observations VRS located at different distances from the\ud worksite was used as the reference. With rapid static we also examined the rule: the\ud observation time = 10 min + 1 min · b, trajanje where b was the distance from the reference\ud station. We found out that the observation time needs to be longer if we are further away\ud from the reference station

Proposal for a chaotic ratchet using cold atoms in optical lattices

We investigate a new type of quantum ratchet which may be realized by cold atoms in a double-well optical lattice, pulsed with unequal periods. The classical dynamics is chaotic and we find the classical diffusion rate D is asymmetric in momentum up to a finite time t(r). The quantum behavior produces a corresponding asymmetry in the momentum distribution which is "frozen-in" by dynamical localization provided the break time t* greater than or equal to t(r). We conclude that the cold atom ratchets require Db/(h) over bar similar to 1, where b is a small deviation from period-one pulses

Chemical transport modeling of potential atmospheric CO2 sinks

The potential for carbon dioxide (CO2) sequestration via engineered chemical sinks is investigated using a three dimensional chemical transport model (CTM). Meteorological and chemical constraints for flat or vertical systems that would absorb CO2 from the atmosphere, as well as an example chemical system of calcium hydroxide (Ca(OH)2) proposed by Elliott et al. [Compensation of atmospheric CO2 buildup through engineered chemical sinkage, Geophys. Res. Lett. 28 (2001) 1235] are reviewed. The CTM examines land based deposition sinks, with 4° × 5° latitude/longitude resolution at various locations, and deposition velocities (v). A maximum uptake of ∼20 Gton (1015 g) Cyr-1 is attainable with v ≥ 5 cms-1 at a mid-latitude site. The atmospheric increase of CO2 (3 Gtonyr-1) can be balanced by an engineered sink with an area of no more than 75, 000 km2 at v of 1 cms-1. By building the sink upwards or splitting this area into narrow elements can reduce the active area by more than an order of magnitude as discussed in Dubey et al. © 2002 Elsevier Science Ltd. All rights reserved

Decrease in water clarity of the southern and central North Sea during the 20th century

Light in the marine environment is a key environmental variable coupling physics to marine biogeochemistry and ecology. Weak light penetration reduces light available for photosynthesis, changing energy fluxes through the marine food web. Based on published and unpublished data, this study shows that the central and southern North Sea has become significantly less clear over the second half of the 20th century. In particular, in the different regions and seasons investigated, the average Secchi depth pre-1950 decreased between 25% and 75% compared to the average Secchi depth post-1950. Consequently, in summer pre-1950, most (74%) of the sea floor in the permanently mixed area off East Anglia was within the photic zone. For the last 25+ years, changes in water clarity were more likely driven by an increase in the concentration of suspended sediments, rather than phytoplankton. We suggest that a combination of causes have contributed to this increase in suspended sediments such as changes in sea-bed communities and in weather patterns, decreased sink of sediments in estuaries, and increased coastal erosion. A predicted future increase in storminess (Beniston et al., 2007; Kovats et al., 2014) could enhance the concentration of suspended sediments in the water column and consequently lead to a further decrease in clarity, with potential impacts on phytoplankton production, CO2 fluxes, and fishery production

Large-scale latitudinal and vertical distributions of NMHCs and selected halocarbons in the troposphere over the Pacific Ocean during the March-April 1999 Pacific Exploratory Mission (PEM-Tropics B)

Nonmethane hydrocarbons (NMHCs) and selected halocarbons were measured in whole air samples collected over the remote Pacific Ocean during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) in March and early April 1999. The large-scale spatial distributions of NMHCs and C2Cl4 reveal a much more pronounced north-south interhemispheric gradient, with higher concentrations in the north and lower levels in the south, than for the late August to early October 1996 PEM-Tropics A experiment. Strong continental outflow and winter-long accumulation of pollutants led to seasonally high Northern Hemisphere trace gas levels during PEM-Tropics B. Observations of enhanced levels of Halon 1211 (from developing Asian nations such as the PRC) and CH3Cl (from SE Asian biomass burning) support a significant southern Asian influence at altitudes above 1 km and north of 10° N. By contrast, at low altitude over the North Pacific the dominance of urban/industrial tracers, combined with low levels of Halon 1211 and CH3Cl, indicate a greater influence from developed nations such as Japan, Europe, and North America. Penetration of air exhibiting aged northern hemisphere characteristics was frequently observed at low altitudes over the equatorial central and western Pacific south to ∼5° S. The relative lack of southern hemisphere biomass burning sources and the westerly position of the South Pacific convergence zone contributed to significantly lower PEM-Tropics B mixing ratios of the NMHCs and CH3Cl south of 10° S compared to PEM-Tropics A. Therefore the trace gas composition of the South Pacific troposphere was considerably more representative of minimally polluted tropospheric conditions during PEM-Tropics B. Copyright 2001 by the American Geophysical Union

Food-web structure in relation to environmental gradients and predator-prey ratios in tank-bromeliad ecosystems

Little is known of how linkage patterns between species change along environmental gradients. The small, spatially discrete food webs inhabiting tank-bromeliads provide an excellent opportunity to analyse patterns of community diversity and food-web topology (connectance, linkage density, nestedness) in relation to key environmental variables (habitat size, detrital resource, incident radiation) and predators: prey ratios. We sampled 365 bromeliads in a wide range of understorey environments in French Guiana and used gut contents of invertebrates to draw the corresponding 365 connectance webs. At the bromeliad scale, habitat size (water volume) determined the number of species that constitute food-web nodes, the proportion of predators, and food-web topology. The number of species as well as the proportion of predators within bromeliads declined from open to forested habitats, where the volume of water collected by bromeliads was generally lower because of rainfall interception by the canopy. A core group of microorganisms and generalist detritivores remained relatively constant across environments. This suggests that (i) a highly-connected core ensures food-web stability and key ecosystem functions across environments, and (ii) larger deviations in food-web structures can be expected following disturbance if detritivores share traits that determine responses to environmental changes. While linkage density and nestedness were lower in bromeliads in the forest than in open areas, experiments are needed to confirm a trend for lower food-web stability in the understorey of primary forests

Horizontal patterns of water temperature and salinity in an estuarine tidal channel: Ria de Aveiro

This work presents results from two complementary and interconnected approaches to study water temperature and salinity patterns in an estuarine tidal channel. This channel is one of the four main branches of the Ria de Aveiro, a shallow lagoon located in the Northwest coast of the Iberian Peninsula. Longitudinal and cross-sectional fields of water temperature and salinity were determined by spatial interpolation of field measurements. A numerical model (Mohid) was used in a 2D depth-integrated mode in order to compute water temperature and salinity patterns. The main purpose of this work was to determine the horizontal patterns of water temperature and salinity in the study area, evaluating the effects of the main forcing factors. The field results were depth-integrated and compared to numerical model results. These results obtained using extreme tidal and river runoff forcing, are also presented. The field results reveal that, when the river flow is weak, the tidal intrusion is the main forcing mechanism, generating saline and thermal fronts which migrate with the neap/spring tidal cycle. When the river flow increases, the influence of the freshwater extends almost as far as the mouth of the lagoon and vertical stratification is established. Results of numerical modelling reveal that the implemented model reproduces quite well the observed horizontal patterns. The model was also used to study the hydrology of the study area under extreme forcing conditions. When the model is forced with a low river flow (1 m3 s−1) the results confirm that the hydrology is tidally dominated. When the model is forced with a high river flow (1,000 m3 s−1) the hydrology is dominated by freshwater, as would be expected in such an area

Contemporary Yugoslavian sociopolitical propaganda posters

Diplomsko delo povzema pregled in razvoj politicˇno-sociolosˇkih propagandnih plakatov v obdobju hladne vojne v nekaterih komunisticˇnih drzˇavah ter opredeljuje plakat kot pomemben graficˇni medij takratne politicˇne oblasti, namenjen oglasˇevanju ter ozavesˇcˇanju drzˇavljanov o razlicˇnih politicˇno-sociolosˇkih temah. Na zacˇetku se delo osredotocˇa predvsem na pomen propagande in propagandnih plakatov, nato pa predstavi kratek pregled razvoja propagandnih plakatov v Sovjetski zvezi in Nemsˇki demokraticˇni republiki. Temu sledi podrobnejsˇi pregled slovenskih politicˇno-sociolosˇkih propagandnih plakatov v cˇasu Jugoslavije in njihov razvojod vpliva Sovjetske zveze in Nemsˇke demokraticˇne republike do popolnoma samosvojih plakatov ? konkurencˇnim graficˇnim plakatom zahodne Evrope. Kasneje delo konkretno predstavi nov polozˇaj plakata v 21. stoletju, kjer je poleg plakativnosti pomembna tudi njegova prepoznavnost na razlicˇnih druzˇbenih omrezˇjih. Na podlagi teoreticˇnega dela se v eksperimentalnem delu sprva osredotocˇi na analizo 12 slovenskih plakatov v Jugoslaviji med obdobjem hladne vojne. Nato izpostavi dva dobra primera, ki ju sˇe podrobneje analizira in primerja. To je predvsem dobra osnova za boljsˇe poznavanje slogovnih smeri takratnega cˇasa in vir kreativnega razmisˇljanja. Sledi sam postopek oblikovanja petih plakatov, kjer je vedno najprej predstavljen inspiracijski postopek obravnavane problematike. Ta postopek je pomemben za utemeljitev graficˇnih elementov nasˇe analize, ki so vkljucˇeni v nasˇ plakat in razlago njihove zanimivosti za obravnavano problematiko. Diplomsko delo tudi na kratko pregleda sodobne smernice oblikovanja plakatov, saj zˇeli pretekle elemente interpretirati na moderen nacˇin. Vsakemu inspiracijskemu procesu sledi avtorski odziv na oblikovanje politicˇno-sociolosˇkih plakatov. S celotnim eksperimentalnim delom smo ugotovili, da je prireditev ali popolno prevzemanje preteklih graficˇnih elementov mozˇno in jih na atraktiven nacˇin sodobno upodobi.This diploma thesis summarizes the development of sociopolitical propaganda posters of the Cold War era in the Communist countries to identify the poster as an important graphic medium for advertising the totalitarian political system and to raise awareness of various socio-political issues. The first section focuses especially on the topic of propaganda itself and propaganda posters. It is followed by a brief overview of propaganda posters in the Soviet Union and in the German Democratic State. Afterwards there is a closer look at Slovenian socio-political propaganda posters in the Cold War era and their development from the influence of the Soviet Union, and how they became highly competitive graphic posters to Western Europe graphic design. Finally, there is a look into the new era of the poster in the 21st century, where the striking presence of posters in the streets is no longer the only important factor because of the increasing power of social media. Later on, it is followed by a brief analysis of 12 examples of posters during the Cold War in Slovenia from which 2 were selected, redundantly analyzed and compared to each other. This was especially important for a good understanding of the stylistic directions of those times and so that the creative process was made easier later on. In the experimental part, there is a focus on 5 bigger socio-political problems of modern times, where the problem itself is briefly presented. To trace the detailed descriptions of the research process, where it explored past Slovenian graphic elements of various posters, which later on inspired ideas for our posters. The thesis also focuses on the research in modern poster design guidelines, the interpretation of past graphic elements in a modern way was one of the bigger parts of this thesis and each research work is followed by the author\u27s personal response to the creation of socio-political posters. Throughout our experimental work we have found that it is possible to adapt or completely retrieve past graphic elements and present them in an attractive contemporary way

Predictors of severe sepsis among patients hospitalized for community-acquired pneumonia

Background Severe sepsis, may be present on hospital arrival in approximately one-third of patients with community-acquired pneumonia (CAP). Objective To determine the host characteristics and micro-organisms associated with severe sepsis in patients hospitalized with CAP. Results We performed a prospective multicenter cohort study in 13 Spanish hospital, on 4070 hospi- talized CAP patients, 1529 of whom (37.6%) presented with severe sepsis. Severe sepsis CAP was independently associated with older age ( > 65 years), alcohol abuse (OR, 1.31; 95% CI, 1.07 - 1.61), chronic obstructive pulmonary disease (COPD) (OR, 1.75; 95% CI, 1.50 - 2.04) and renal disease (OR, 1.57; 95% CI, 1.21 - 2.03), whereas prior antibiotic treat- ment was a protective factor (OR, 0.62; 95% CI, 0.52 - 0.73). Bacteremia (OR, 1.37; 95% CI, 1.05 - 1.79), S pneumoniae (OR, 1.59; 95% CI, 1.31 - 1.95) and mixed microbial etiology (OR, 1.65; 95% CI, 1.10 - 2.49) were associated with severe sepsis CAP. Conclusions CAP patients with COPD, renal disease and alcohol abuse, as well as those with CAP due to S pneumonia or mixed micro-organisms are more likely to present to the hospital with severe sepsis