Analysis of stability levee during different flooding wave stages

The stability of levee depends mainly on mechanical and hydromechanical properties of material used for its construction. The structural capacity of a system beyond the expected loads or actual loads is calculated to a variety of different underground structures such as slopes, retaining walls or tunnels. The stability of structure is often expressed by Factor of Stability (FoS) obtained by numerical modeling. In case of the stability analysis of the levee, the flooding process is limited to few scenarios of flooding waves. The first approach of determination of the most significant stages of flooding wave shape can be found in Dwornik et al. (2015). In this paper, the stability of earthen levee for different stages and flooding waves was calculated. Stability of the levee was described using Factor of Safety implemented in Itasca Flac 2D 7.0 software using the strength reduction procedure (Itasca 2011). It is applied by a strength reduction method, which reduces the shear strength of the material to bring the slope to a state of limiting equilibrium. The value of FoS bigger than 1.0 indicate the stable construction, whereas the value less than 1.0 should be interpreted as a possible unstable model (Itasca 2011). Numerical modeling presented in this paper was performed for 17 different schemes of flooding wave. All the schemas were slight modification of the flooding wave considered during the ISMOP project (www.ismop.pl, Mościcki et al. 2014). The analysis was conducted to the flooding wave described by the four stages: water level increasing, durability of the height water level, the pace of water level decreasing and durability of the stage between cycles of successive flooding waves. The increasing of the water level assumed in the numerical modeling varied from 0.1 m to 3.5 m in height. The high water level, assumed as a 3.5 m, was different for the individual scenario. The decreasing water level varied from 3.5 m to 0.1 m preceding the low water level assumed 0.1 m in height. Calculations show that levee is stable for all tested construction stages. The lowest FoS value was obtained after decreasing water level in the reservoir between levees. The slowest pace of decreasing water level was assumed, the higher value of FoS was obtain, which indicated better levee stability.wersja wydawnicz

Influence of initial water saturation in earthen levees on results of numerical modelling of infiltration processes

Levees in Poland are mostly earthen constructions. The stability of earthen levees depends largely on factors such as the construction material, meteorological conditions and natural elements. The influence of initial water saturation of pore space on levee stability is analysed in this paper. Analysis was performed using numerical modelling and water pore pressure results were compared against data obtained from sensors located in a levee. The numerical modelling shows the moderate influence of initial water level on distribution of water pore pressure during high water level

Wolność oczami dziecka – poznawcza reprezentacja wolności w średnim i późnym dzieciństwie

The paper presents the results of research on cognitive representation of freedom in middle and late childhood, based on the philosophical and psychological understanding of the issue. The basis of the considerations were classic models of representation: J. Piaget and L. Wygotski, modern models: A. Karmiloff-Smith, K. Nelson, J. Mandler and theory of building the experience of M. Tyszkowa. These theories say that cognitive representation is uniquely human way of gaining knowledge which is connected with continuous redescription of obtained information. The research involved 33 six-year-old- and 31 nine-year-old children. Researchers used the Piaget’s clinical method which was based on a created questionnaire. The children’s task was to provide connotations with the word freedom, paint the freedom and tell about the possibility of making decisions in their relationship with parents.Obtained material (verbal and non-verbal) shows that children use the representations of freedom at the implicit and explicit level.W artykule zaprezentowano wyniki badań nad poznawczą reprezentacją wolności u dzieci w średnim i późnym dzieciństwie, w oparciu o filozoficzne i psychologiczne rozumienie niniejszej problematyki. Podstawą rozważań były klasyczne: J. Piageta i L. Wygotskiego,i współczesne: A. Karmiloff- Smith, K. Nelson, J. Mandler modele reprezentacji oraz koncepcja budowania doświadczenia M. Tyszkowej. Wymienione koncepcje pozwalają ujmować reprezentację poznawczą w kategoriach specyficznie ludzkiego sposobu zdobywania wiedzy, który polega na ciągłej redeskrypcji posiadanych informacji. Badaniami objęto trzydzieścioro troje dzieci w wieku sześciu lat i trzydzieścioro jeden w wieku dziewięciu lat. Wykorzystana została metoda kliniczna Piageta w oparciu o stworzony kwestionariusz. Dzieci wymieniały skojarzenia ze słowem wolność, przedstawiały ją w sposób graficzny i prezentowały możliwość podejmowania decyzji w relacji z rodzicami. Zebrany materiał werbalny i niewerbalny pokazuje, że dzieci posługują się reprezentacjami wolności na poziomie ukrytym i jawnym

Positioning system of the photovoltaic batteries

W artykule przedstawiono koncepcję automatycznego układu nadążnego umożliwiającego pozycjonowanie baterii fotogalwanicznych względem słońca. Położenie ziemi wobec słońca jest zmienne i zależne od pory roku oraz dnia. W celu absorpcji jak największej części energii emitowanej przez słońce, konieczne jest zastosowanie aktywnego systemu śledzenia. Przedstawione w artykule rozwiązanie ma na celu podniesienie wydajności baterii fotowoltaicznych lub kolektorów słonecznych. W pracy wskazano przykłady i możliwości zastosowania baterii słonecznych w pojazdach szynowych.The paper presents the concept of auto-positioning the following system enabling the positioning of the photovoltaic batteries relative to the sun. Location of the earth to the sun is variable and dependent on the season and day. In order to absorb the largest part of energy emitted by the sun it is necessary to apply the active tracking system. The aim of solution presented in this article is improving the efficiency of photovoltaic batteries or solar panels. The examples and applicability of solar panels in rail vehicles are identified in the study

Numerical modelling of levee stability based on coupled mechanical, thermal and hydrogeological processes

The numerical modelling of coupled mechanical, thermal and hydrogeological processes for a soil levee is presented in the paper. The modelling was performed for a real levee that was built in Poland as a part of the ISMOP project. Only four parameters were changed to build different flood waves: the water level, period of water increase, period of water decrease, and period of low water level after the experiment. Results of numerical modelling shows that it is possible and advisable to calculate simultaneously changes of thermal and hydro-mechanical fields. The presented results show that it is also possible to use thermal sensors in place of more expensive pore pressure sensors, with some limitations. The results of stability analysis show that the levee is less stable when the water level decreases, after which factor of safety decreases significantly. For all flooding wave parameters described in the paper, the levee is very stable and factor of safety variations for any particular stage were not very large

Numerical modelling of levee stability based on coupled mechanical, thermal and hydrogeological processes

The numerical modelling of coupled mechanical, thermal and hydrogeological processes for a soil levee is presented in the paper. The modelling was performed for a real levee that was built in Poland as a part of the ISMOP project. Only four parameters were changed to build different flood waves: the water level, period of water increase, period of water decrease, and period of low water level after the experiment. Results of numerical modelling shows that it is possible and advisable to calculate simultaneously changes of thermal and hydro-mechanical fields. The presented results show that it is also possible to use thermal sensors in place of more expensive pore pressure sensors, with some limitations. The results of stability analysis show that the levee is less stable when the water level decreases, after which factor of safety decreases significantly. For all flooding wave parameters described in the paper, the levee is very stable and factor of safety variations for any particular stage were not very large

Numerical modelling of levee stability based on coupled mechanical, thermal and hydrogeological processes

The numerical modelling of coupled mechanical, thermal and hydrogeological processes for a soil levee is presented in the paper. The modelling was performed for a real levee that was built in Poland as a part of the ISMOP project. Only four parameters were changed to build different flood waves: the water level, period of water increase, period of water decrease, and period of low water level after the experiment. Results of numerical modelling shows that it is possible and advisable to calculate simultaneously changes of thermal and hydro-mechanical fields. The presented results show that it is also possible to use thermal sensors in place of more expensive pore pressure sensors, with some limitations. The results of stability analysis show that the levee is less stable when the water level decreases, after which factor of safety decreases significantly. For all flooding wave parameters described in the paper, the levee is very stable and factor of safety variations for any particular stage were not very large

Isolated axillary lymph node tuberculosis in ultrasonography. A case report

We present a rare case of isolated axillary lymph node tuberculosis. A 66‑year‑old patient was admitted in order to perform the diagnostics of a painless tumor of the left armpit. Blood biochemistry tests and chest X‑ray did not show any abnormalities. In the ultrasound examination a solid structure of the dimensions of 1.8×1 cm of irregular outline with adjacent hypoechogenic lymph nodes was visualized. The di‑ agnosis of tuberculosis was based on histopathologic examination of the excised tu‑ mor. In the latter years an increase in extrapulmonary type of tuberculosis has been observed. Extrapulmonary tuberculosis may appear in practically each organ, never‑ theless it affects pleura most often. Lymph node tuberculosis is the second, when it comes to the prevalence rate, type of extrapulmonary tuberculosis. In the majority of cases of lymph node tuberculosis it affects superficial lymph nodes. In the ultrasound examination a packet of pathological, enlarged and hypoechogenic lymph nodes is stated. In 1/3 of cases the central part of the nodes is hyperechogenic which indicates its caseation necrosis. Lymph nodes have a tendency to be matted and they have blurred outline. We observed this type of lymph node image in the presented patient. This image may be a diagnostic hint. Nevertheless, in the differentiation diagnostics one should take many other disease entities into consideration, inter alia: sarcoidosis, lymphomas, fungal infections, neoplastic metastases; the latter ones have an image most similar to tuberculosis lymph nodes. Tuberculosis ought to be considered in dif‑ ferential diagnosis of atypical masses