Search

Start Over Language Slovak Rights policy:public

2274. Relation between phase density and component concentration in groundwater flow modelling

Creator:
Ondovčin, Tomáš and Mls, Jiří
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
groundwater flow, density-dependent flow, solution density, contaminant concentration, mathematical modelling, contaminant hydrogeology, proudění podzemní vody, hustotně závislé proudění, hustota roztoku, koncentrace kontaminantu, matematické modelování, and kontaminační hydrogeologie
Language:
Slovak
Description:
When investigating contaminant transport in groundwater aquifers, it is important to take into account the aqueous-phase density. In order to get the required information, the knowledge of functional relationship between the contaminant concentration and the aqueous-phase density is necessary. In this paper, the relationship was found for ten solutes commonly occurring in groundwater, namely CaCl2, KCl, K2CO3, K2SO4, KHSO4, Na2CO3, NaCl, Na2SO4, MgSO4 and MgCl2. Linear, parabolic and power functions have been applied and several quantities (mass fraction, molality, molarity, molar fraction, ionic strength and mass-volume concentration) have been considered in order to get the best accuracy of the obtained relationship. Finally, the problem of multicomponent solutions was solved. A new method of density determination was developed which makes use of known single-component relationships. The method was tested and its efficiency was verified and documented. and Při řešení problémů transportu kontaminantů v prostředí podzemní vody je důležité vzít v úvahu hustotu proudící fáze. K její znalosti je nezbytně nutná znalost závislosti hustoty fáze na koncentraci kontaminantu. Článek přináší potřebné funkční závislosti získané pro deset různých látek běžně se vyskytujících v prostředí podzemní vody, konkrétně pro CaCl2, KCl, K2CO3, K2SO4, KHSO4, Na2CO3, NaCl, Na2SO4, MgSO4 a MgCl2. Tři funkce, lineární, kvadratická a mocninná byly použity v kombinaci s různými veličinami (hmotnostní zlomek, molalita, molarita, molární zlomek, iontová síla a koncentrace) při hledání nejpřesnější formy výsledného vztahu. Problém byl následně řešen pro vícesložkové roztoky. Byla nalezena nová metoda využívající znalosti jednosložkových závislostí. Přesnost této metody byla v článku ověřena a dokumentována.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2275. Relation of influencing variables and weather conditions on rainfall partitioning by birch and pine trees

Creator:
Zabret, Katarina and Šraj, Mojca
Format:
počítač and online zdroj
Type:
model:article and TEXT
Subject:
throughfall, stemflow, rainfall interception, rainfall microstructure, boosted regression trees, and random forest
Language:
Slovak
Description:
General weather conditions may have a strong influence on the individual elements of the hydrological cycle, an important part of which is rainfall interception. The influence of general weather conditions on this process was analysed, evaluating separately the influence of various variables on throughfall, stemflow, and rainfall interception for a wet (2014), a dry (2015), and an average (2016) year. The analysed data were measured for the case of birch and pine trees at a study site in the city of Ljubljana, Slovenia. The relationship between the components of rainfall partitioning and the influential variables for the selected years was estimated using two statistical models, namely boosted regression trees and random forest. The results of both implemented models complemented each other well, as both indicated the rainfall amount and the number of raindrops as the most influential variables. During the wet year 2014 rainfall duration seems to play an important role, correlating with the previously observed influence of the variables during the wetter leafless period. Similarly, during the dry year 2015, rainfall intensity had a significant influence on rainfall partitioning by the birch tree, again corresponding to the influences observed during the drier leafed period.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2276. Relationships between soil water repellency and microbial community composition under different plant species in a Mediterranean semiarid forest

Creator:
Lozano, Elena, García-Orenes, Fuensanta, Bárcenas-Moreno, Gema, Jiménez-Pinilla, Patricia, Mataix-Solera, Jorge, Arcenegui, Victoria, Morugán-Coronado, Alicia, and Mataix-Beneyto, Jorge
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
soil hydrophobicity, phospholipids fatty acids, microbial community structure, biohydrology, actinobacteria, and glomalin related soil protein
Language:
Slovak
Description:
Soil water repellency (SWR) can influence many hydrological soil properties, including water infiltration, uneven moisture distribution or water retention. In the current study we investigated how variable SWR persistence in the field is related to the soil microbial community under different plant species (P. halepensis, Q. rotundifolia, C. albidus and R. officinalis) in a Mediterranean forest. The soil microbial community was determined through phospholipid fatty acids (PLFA). The relationships between microbiological community structure and the soil properties pH, Glomalin Related Soil Protein (GRSP) and soil organic matter (SOM) content were also studied. Different statistical analyses were used: Principal Component Analysis (PCA), ANOVA, Redundancy Analysis and Pearson correlations. The highest concentrations of PLFA were found in the most water repellent samples. PCA showed that microorganism composition was more dependent of the severity of SWR than the type of plant species. In the Redundancy Analysis, SWR was the only significant factor (p<0.05) to explain PLFA distributions. The only PLFA biomarkers directly related to SWR were associated with Actinobacteria (10Me16:0, 10Me17:0 and 10Me18:0). All the results suggest that a strong dependence between SWR and microbial community composition.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2277. Remote-sensing based groundwater recharge estimates in the Danube-Tisza sand plateau region of Hungary

Creator:
Szilágyi, József, Kovács, Ákos, and Józsa, János
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
groundwater recharge, MODIS data, Danube-Tisza sand plateau, doplňovanie podzemných vôd, MODIS, and plató Dunaj-Tisa
Language:
Slovak
Description:
Mean annual recharge in the Danube-Tisza sand plateau region of Hungary over the 2000-2008 period was estimated at a 1-km spatial resolution as the difference of mean annual precipitation (P) and evapotranspiration (ET). The ET rates were derived from linear transformations of the MODIS daytime land surface temperature (Ts) values with the help of ancillary atmospheric data (air temperature, humidity, and sunshine duration). The groundwater under the sand plateau receives about 75 ± 50 mm of recharge annually (the plus/minus value is the associated error, resulting from an assumed 5% error in both the P and ET values), which is about 14 ± 9 % of the regional mean annual P value of 550 mm. The largest continuous region with elevated recharge rates (about 180 ± 50 mm a-1 or 30 ± 8 % of P) occur in the south-western part of the plateau due to more abundant precipitation (around 580 mm a-1), while recharge is the smallest (about 40 ± 40 mm a-1 or 7 ± 7 % of P) under forested areas. Typically, lakes, wetlands, river valleys, and certain afforested areas in the north-central part of the region act as discharge areas for groundwater. and Priemerný ročný úhrn doplňovania podzemných vôd plošiny zloženej z pieskov medzi riekami Dunaj a Tisa s rozlíšením 1 km, pre roky 2000-2008 bol určený ako rozdiel medzi priemerným ročným úhrnom zrážok (P) a evapotranspiráciou (ET). ET bolo určené z lineárnej transformácie teploty povrchu počas dňa (Ts) získanej systémom MODIS pomocou údajov o vlastnostiach atmosféry (teplota vzduchu, vlhkosť vzduchu a trvanie slnečného svitu). Podzemná voda pod pieskovým masívom dostáva ročne asi 75 ± 50 mm vody (znamienka plus/mínus znamenajú chybu, vyplývajúcu z predpokladanej 5% chyby hodnôt P a ET), ktorá je asi 14 ± 9 % regionálnej priemernej ročnej hodnoty P, ktorá je 550 mm. Najväčšia spojitá oblasť so zvýšeným doplňovaním podzemnej vody (približne 180 ± 50 mm za rok alebo 30 ± 8 % P) sa nachádza v juhozápadnej časti plató a je dôsledkom vyššieho ročného úhrnu zrážok (okolo 580 mm), doplňovanie je nižšie v zalesnených oblastiach (okolo 40 ± 40 mm, alebo 7 ± 7 % P). Jazerá, mokrade, rieky a niektoré zalesnené oblasti v strednej a severnej časti tejto oblasti drénujú podzemné vody.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2278. Rentgenové zobrazovacie vyšetrenia u pacientov s pectus excavatum

Creator:
Lučenič, Martin, Janík, Miroslav, Juhos, Peter, Benej, Roman, and Harušiak, Svetozár
Format:
braille, text, and regular print
Type:
model:article, article, Text, and TEXT
Subject:
hrudník vpáčený--klasifikace--radioizotopová diagnostika, rentgendiagnostika hrudníku--metody--využití, tomografie rentgenová počítačová--využití, stupeň závažnosti nemoci, hrudní chirurgické výkony, výsledky a postupy - zhodnocení (zdravotní péče), pooperační komplikace, recidiva, protézy - implantace, rekonstrukční chirurgické výkony, zobrazování trojrozměrné, and lidé
Language:
Czech, Slovak, and English
Description:
Pectus excavatum je najčastejšou vrodenou deformitou hrudníka. Deformitu ťažkého stupňa musíme považovať za absolútnu indikáciu na operačnú korekciu. Závažnosť deformity určená s pomocou rentgenových zobrazovacích vyšetrení je najdôležitejším indikačným kritériom. Štandardné RTG vyšetrenie hrudníka v dvoch projekciách, natívne špirálové MDCT vyšetrenie ponúkajú možnosť zhodnotiť rôzne základné ukazovatele závažnosti deformity, ako sú napríklad Halierov index, korekčný vertebrálny a fronto-sagitálny index. Rozvoj minimálne invazívnych operačných techník a narastajúci počet pacientov s asymetrickou deformitou liečených touto technikou priniesol potrebu nových indexov, ktoré operatérovi umožnia individuálne predtvarovať dlahu aj v tejto skupine pacientov. Autori práce sa v práci zamerali aj na komplikácie operačnej korekcie a typické nálezy, ktoré umožnia rentgenológovi tieto komplikácie zachytiť., Pectus excavatum is the most common inborn deformity of the chest. Severe deformity is considered to be an absolute indication for surgical correction. Indication criterias are dependent on multiple factors, but the severity of the malformation based on rádiológie assessment is the most important. Standard chest X-ray and native MDCT examination offer the evaluation of the severity of the deformity with the use of basic indices like Halier, correctional, vertebral or fronto-sagittal index. The evolution of minimally invasive pectus excavatum repair (MIRPE) and high number of asymmetric deformities treated with this procedure has brought the necessity for the creation of new indices. These indices help surgeons to individually preshape implanted bar in complex cases. Authors concentrate on complications of both procedures and their typical radiological findings., Martin Lučenič, Miroslav Janík, Peter Juhos, Roman Benej, Svetozár Harušiak, and Literatura
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

Limit your search

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

View distribution

Current results range from 1852 to 2023

View larger »