Nonlinear dynamical system - problem still open

W pracy przedstawiono zjawisko wystąpienia synchronizacji oscylatorów typu Duffing podwieszonych do elastycznej belki. Zbadano wpływ zmiany modelu belki na zachowanie oscylatorów. Wykazano, że dla danych warunków początkowych wzbudzenia, początkowo nieliniowe, chaotyczne oscylacje struktury stają się okresowe i synchroniczne.The paper presents the phenomenon of synchronization of Duffing oscillators suspended on a flexible beam. This article presents the results of changes in the beam model on the behavior of oscillators. It was shown that for the initial conditions of excitation, initially nonlinear, chaotic oscillations of structures become periodic and synchronous

Dynamics of system coupled by elastic structure.

W pracy przedstawiono zjawisko wystąpienia synchronizacji mechanicznych oscylatorów zamocowanych na elastycznej strukturze. Wykazano, że dla danych warunków wzbudzenia [1] początkowo nieliniowe, chaotyczne oscylacje struktury stają się okresowe i synchroniczne. W warunkach, kiedy częstości wzbudzenia różnią się, zjawiska powyższe nie występują. Obliczenia przeprowadzono MES, wykorzystując profesjonalny pakiet programu ANSYS.This article presents the result of numerical analysis of the structure witch consist of two identical chaotic oscillators suspended on an elastic structure. The numerical calculations have been achieved with the use of the professional ANSYS programme (User’s Guide ANSYS 10 [7]). The finding show that for the given conditions of excitations initially uncollerated chaotic oscillations of the structure become periodic and synchronous in clusters. Cluster means a group metronoms which behave identically. When the excitation frequencies vary, the phenomena described above have not been observed at all

Inertial sensors in the stabilization system of the balancing vehicle

The article presents the possibilities of using popular MEMS inertial sensors in the object tilt angle estimation system and in the system for stabilizing the vertical position of the balancing robot. Two research models were built to conduct the experiment. The models use microcontroller development board of the STM32F3 series with the Cortex-M4 core, equipped with a three-axis accelerometer, magnetometer and gyroscope. To determine the accuracy of the angle estimation, comparative tests with a pulse encoder were performed

Źródła archiwalne na temat Centralnego Okręgu Przemysłowego w aktach instytucji samorządu gospodarczego

W rozdziale omówiono archiwalia znajdujące się w zespołach izb przemysłowo-handlowych w Krakowie i Poznaniu, jak również izb rolniczych i rzemieślniczych. W tym przypadku chodzi głównie o Krakowską Izbę Rolniczą oraz izby rzemieślnicze w Krakowie i Lwowie. Pokazują one, jak bogatą działalność - w krótkim czasie budowy COP - rozwinęły instytucje samorządu gospodarczego. Izby interesowały się nie tylko warunkami zakładania i prowadzenia działalności gospodarczej, ale wszelakimi przejawami życia społecznego na terenie poddanym intensywnemu procesowi inwestycji publicznych uwarunkowanych doktryną interwencjonizmu państwowego

Multiple interment loculi tombs at Tell Dothan -- burial behaviour as cultural process in the Late Bronze/Early Iron I Levant

What is considered anomalous among the Late Bronze/Iron I Age Canaanite tomb plans rests on the understanding of the ‘foreign’ and the ‘local’ elements of interments of that period. When Diane Bolger, in her discussion of ancient Cypriot mortuary practices, noted the shift in the scholarly literature from the emphasis on the identity and status of the dead to an examination of the ways in which rituals of death and burial reveal the motives and identities of the living (Bolger 2003), her observation highlighted the importance of burial as a process rather than an event. The phenomenon of burials in loculi chamber tombs during the ‘transitional’ period of the end of the Late Bronze and beginning of the Early Iron Age is explored, building on the foundations established by Rivka Gonen’s work on Late Bronze burial behaviour in Canaan (Gonen 1992). The structural and ritual characteristics of the tombs that present evidence for cultural context and origins are considered, establishing whether the archaeological remains translate into a picture of a regional variation or a foreign influence. Are the Late Bronze/Iron I burials in Canaan examples of an amalgamation of cultural traits of variable geographical origins or did they represent an ‘immigration’ of a mortuary custom? Why are loculi cave burials considered intrusive in the Canaanite territory?The examination of Tell Dothan, Lachish, Tell el-‘Ajjul and Megiddo, and of the Cypriot sites of Ayios Iakovos Melia, Lapithos Vrysi tou Barba, Korovia Paleoskoutella and Dhenia Kafkalla facilitates the discussion of loculi chamber tomb plan interments in the Levant have prompted

Numerical analysis of creation of the local concentrations of stresses in research of internal load of rooling bearings

W pracy przedstawiono wyniki analizy numerycznej powstawania lokalnych koncentracji naprężeń elementów tocznych w warunkach pracy. Obliczenia przeprowadzono dla elementów wykonanych z materiału idealnie sprężystego oraz z materiału sprężystoplastycznego z kinematycznym wzmocnieniem liniowym. W pracy zaprezentowano modelowanie strefy styku. Obliczenia wykonano, stosując MES, profesjonalny pakiet ANSYS.The paper presents the results of the numerical analysis of the local concentrations of stresses of rolling elements in working condition and process of modelling of the contact zone. Calculations were done for the elements made of the elastic-ideally plastic material and the elastic-plastic material with kinematic linear reinforcement using MES, professional package ANSYS

Atresia of the esophagus - thoracotomy vs thoracoscopy

Esophageal atresia is a congenital medical condition associated with the disorder of the alimentary tract. It is usually associated with one or more fistulas to the trachea. Esophageal atresia is often associated with other congenital defects. The most frequent anomalies with atresia of the esophagus are those that occur in the VACTERL association. The incidence of oesophageal atresia mention in the literature varies 0.7-4.55/10000, because of the different percentage of defects other than esophageal atresia and associated with esophageal atresia changes. The etiology of esophageal atresia is mainly unknown, but it is considered multifactorial, including genetic and environmental factors. Indeed, 6-10% of cases of esophageal atresia have been diagnosed with a chromosomal abnormality or syndrome. For the purpose of this study, we analyzed the current papers on esophageal atresia found in the PubMed database. Traditionally, the esophageal atresia has been operated by the right posterior thoracotomy. The first thoracoscopic repair of classic esophageal atresia was performed in 1999, and the first successful thoracoscopy of the tracheo-oesophageal fistula a year later. Together with these milestones, numerous health centers have begun adapting this surgical technique. Although thoracoscopic surgery in the case of esophageal atresia in patients with tracheo-bronchial fistula was conducted in many highly developed children's surgery centers, the safety and efficacy of this method remained controversial. The benefits of thoracoscopic surgery are obvious, including excellent visualization, less use of post-operative drugs and cosmetic effects. Jaureguiza et al. described the "scaly scapula", chest wall deformity, scoliosis and the development of the bad nipple in patients who underwent open surgery due to esophageal atresia with the accompanying tacha-oesophageal fistula. In the case of open thoracotomy, it was necessary to withdraw the lungs to expose the posterior mediastinum, resulting in lung damage and respiratory complications. Compared to the open surgery, thoracoscopy significantly reduced the time of hospital stay and the moment of the first oral meal. However, thoracoscopy was associated with a longer time of surgery. The incidence of leaks, narrowings, pulmonary complications, and blood loss were similar in both surgical technique. It seems that the benefits of thoracoscopy are significant

Use of the finite element method in the analysis of internal load of rolling bearings.

Wyznaczanie rozkładów naprężeń podpowierzchniowych, obciążeń i nacisków jest decydującym elementem w prognozowaniu trwałości zmęczeniowej łożysk tocznych. W pracy przedstawiono wyniki obliczeń numerycznych obliczania naprężeń kontaktowych w węzłach tocznych – łożyskach. Obliczenia wykonano, stosując MES, profesjonalny pakiet ANSYS.Determination of subsurface stresses distributions, loads, and pressures is the decisive element in predicting fatigue life of rolling bearings. The article presents the results of the numerical calculations of contact loads in rolling bearing. Calculations were done using FEM in ANSYS