Synchronization in arrays of coupled self-induced friction oscillators

We investigate synchronization phenomena in systems of self-induced dry friction oscillators with kinematic excitation coupled by linear springs. Friction force is modelled according to exponential model. Initially, a single degree of freedom mass-spring system on a moving belt is considered to check the type of motion of the system (periodic, non-periodic). Then the system is coupled in chain of identical oscillators starting from two, up to four oscillators. A reference probe of two coupled oscillators is applied in order to detect synchronization thresholds for both periodic and non-periodic motion of the system. The master stability function is applied to predict the synchronization thresholds for longer chains of oscillators basing on two oscillator probe. It is shown that synchronization is possible both for three and four coupled oscillators under certain circumstances. Our results confirmed that this technique can be also applied for the systems with discontinuities.This work has been supported by National Science Center – Poland (NCN) in frame of Project no. DEC-2012/06/A/ST8/00356

High performance membrane materials for gas separation

The use of membranes in various gas separations has increased significantly in recent times. This review presents some of the recent noteworthy advances in the field of membranes materials for these applications. A description of the most promising groups of high free volume polymers, including polyimides, thermally rearranged (TR) polymers, substituted polyacetylenes, perfluoropolymers, and polymers with intrinsic microporosity (PIM) is provided. High performance, rubbery, polyethers and polyether based copolymers are shown as another important class of polymer membrane materials.  The development of inorganic membranes, which are not bound to the trade-off limitations between permeability and selectivity exhibited by polymers is also presented. The attention is focused on zeolitic materials, metal organic frameworks (MOF), and carbon molecular sieves (CMS). The field of mixed matrix membranes composed of inorganic particles embedded in a polymer matrix is also briefly outlined

Adrenal metastases

The adrenal glands are one of the most prevalent sites for metastases from various malignancies and metastases are indeed the most frequent malignant tumors of the adrenals. The identification of incidental adrenal lesions, of which a high proportion are metastases, have increased since surveillance protocols in cancer treated patients were widely introduced. More sensitive and reliable methods of diagnostic imaging leads to earlier detection of adrenal metastases. If there are no signs and symptoms of disseminated malignant disease, it is essential to differentiate adrenal lesions. CT imaging diagnostics and MRI play the main role in differential diagnosis. Adrenal biopsy is not recommended and is of limited diagnostic value. Appropriate selection of patients with adrenal metastases for curative treatment is a great challenge. Hormonal evaluation should be performed prior to treatment. Adrenalectomy seems to be a reasonable treatment for isolated adrenal metastasis in suitable patients. Minimally invasive laparoscopic adrenalectomy is as effective as the open approach with proven reduction in postoperative pain, morbidity and length of stay. Nonsurgical treatment such as stereotactic body radiation therapy (SBRT), radiotherapy with CyberKnife, percutaneous radiofrequency ablation, percutaneous microwave ablation, radiofrequency plus chemoembolization combined, have been reported with curative and palliative intent and have shown varied results

Adrenal metastases

The adrenal glands are one of the most prevalent sites for metastases from various malignancies and metastases are indeed the most frequent malignant tumors of the adrenals. The identification of incidental adrenal lesions, of which a high proportion are metastases, have increased since surveillance protocols in cancer treated patients were widely introduced. More sensitive and reliable methods of diagnostic imaging leads to earlier detection of adrenal metastases. If there are no signs and symptoms of disseminated malignant disease, it is essential to differentiate adrenal lesions. CT imaging diagnostics and MRI play the main role in differential diagnosis. Adrenal biopsy is not recommended and is of limited diagnostic value. Appropriate selection of patients with adrenal metastases for curative treatment is a great challenge. Hormonal evaluation should be performed prior to treatment. Adrenalectomy seems to be a reaso­nable treatment for isolated adrenal metastasis in suitable patients. Minimally invasive laparoscopic adrenalectomy is as effective as the open approach with proven reduction in postoperative pain, morbidity and length of stay. Non­surgical treatment such as stereotactic body radiation therapy (SBRT), radiotherapy with CyberKnife, percutaneous radiofrequency ablation, percutaneous microwave ablation, radiofrequency plus chemoembolization combined, have been reported with curative and palliative intent and have shown varied results

The influence of waters from hard-coal mines on the hydrochemical relations of Upper Silesian Coal Basin (USCB) rivers

Surface waters of the Upper Silesian Coal Basin (USCB) are highly transformed in quality as a consequence of salty minewater discharge to the hydrographic net. These waters drain coal beds which are extracted to a depth of 1000 m. The amount of minewater, discharging directly or indirectly to the river net of the USCB reaches 8-9 m3/s with a variability in particular years of 1-1.5 m3/s, which depends on hydrological conditions of the levels extracted. In 1994, the salt load introduced together with these waters to the Vistula and the Oder reached 6793 tons per 24 hours of chloride ions and 1351 tons per 24 hours of sulphate ions. This accounted for over 50% of the chlorides and about 35% of the sulphates discharged to surface waters in the country. Furthermore, a part of the minewater also contains radioactive elements (radium22 ). The chance to improve the quality of the Oder and Vistula waters in the nearest future is meagre

Electric shock safety in automotive electrical systems

The article presents the issue of electric shock safety in automotive electrical systems, discussed from two different points of view, that is the point of view of a user and the point of view of the garage personnel. The authors also review the requirements posed by the norms that are in force in this area, and discuss the problems concerning the levels of the applied and the generated voltage, which are presented with reference to typical 14 V and 28 V automotive electrical systems, 42 V systems, and the systems used in hybrid and electric cars

Baza noclegowa jako element zagospodarowania turystycznego Ustronia - śląskiego uzdrowiska statutowego

"Przestrzeń geograficzna, składająca się z elementów naturalnych (środowisko przyrodnicze) oraz antropogenicznych (środowisko antropogeniczne), stanowi źródło walorów turystycznych, które odpowiednio przystosowane do obsługi ruchu turystycznego, mogą zmienić się w atrakcje, a następnie produkty turystyczne. Wszystkie działania zmierzające do przystosowania środowiska geograficznego dla potrzeb turystyki określone zostały jako zagospodarowanie turystyczne, które może być prowadzone w celach: przystosowania walorów turystycznych, zapewnienia możliwości dojazdu oraz zapewnienia niezbędnych warunków egzystencji turystów1. Zagospodarowanie turystyczne (infrastruktura turystyczna) stanowi zbiór wszystkich obiektów, urządzeń, instytucji, a więc całą bazę świadczącą usługi dla turystów2. Obejmuje ono zatem wszystkie te elementy, które zapewniają prawidłowe funkcjonowanie miejsca recepcji turystycznej, stanowiąc bardzo istotny element rozwoju turystyki w danym regionie"