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71.
72.
Edward J. Marcin 《Rocks & Minerals》2013,88(9-10):424-425
73.
Marcin Słoma Małgorzata Jakubowska Andrzej Kolek Krzysztof Mleczko Piotr Ptak Adam Witold Stadler Zbigniew Zawiślak Anna Młożniak 《Journal of Materials Science: Materials in Electronics》2011,22(9):1321-1329
This paper presents the results of authors investigations on elaboration of a new thick film composition filled with carbon
nanotubes (CNTs). The polymer composition consists of polymer vehicle, which is the solution of organic resin in certain combination
of solvents, and functional phase—carbon nanotubes well dispersed in the vehicle. The pastes were applied with screen-printing
on several substrates and temperature cured. The properties of obtained layers were characterized. Series of samples were
prepared with different amount of CNTs to evaluate electrical properties. Changes in resistance were investigated during periodic
mechanical and temperature stresses, realized through cyclical bending and rapid temperature change. Tensometric effect was
also investigated. Investigations have proved that polymer composites based on carbon nanotubes exhibit high resilience to
stress factors. Resistance change in function of temperature was also investigated to evaluate temperature coefficient of
resistance (TCR). All this aspects are important for elastic resistors fabrication in printed electronics microcircuits. Resistance
and noise measurements in cryostats have also been involved. 1/f type noise has been observed. Noise intensity, calculated
in decade frequency bands, rises significantly with increasing temperature. Activation energies of thermally activated noise
sources (TANS) have been revealed using low-frequency noise spectroscopy. Relatively large value of negative TCR has been
obtained from resistance versus temperature curve. Calculated dimensionless sensitivity is similar to that observed in cryogenic
temperature sensors. However, bulk noise intensity of resistive layer is larger than obtained for lead containing RuO2 based resistive layers. 相似文献
74.
Eugeniusz Rusiński Jerzy Czmochowski Artur Iluk Marcin Kowalczyk 《Engineering Failure Analysis》2010,17(1):179-191
A bucket wheel excavator (BWE) collapsed in a brown coal mine. As a result of a tie rod fracture the counterweight boom, the discharge boom and several other components of the other assemblies underwent plastic deformation. This paper presents the results of computer simulations of the collapse. A finite element method analysis of the counterweight boom tie rod showed stress concentrations exceeding the allowable level. Also material tests of the fracture surface were carried out to identify the causes of the collapse. Macroscopic and microscopic images of areas within the fracture were obtained. Measurements of hardness and microhardness in the vicinity of the weld were performed. The FEM analyses and material tests showed that the causes of the collapse were design and welding faults. 相似文献
75.
Andrzej Wrbel ukasz Zapaa Tomasz Kluz Artur Rogowski Marcin Misiek Kajetan Juszczak Jacek Sieko Daniela Gold Klaudia Stangel-Wjcikiewicz Ewa Poleszak Piotr Radziszewski 《International journal of molecular sciences》2021,22(11)
The purpose of this study was to determine if asiatic acid may act efficiently in the model of cyclophosphamide (CYP)-induced cystitis in rats. We performed experiments after administration of CYP (single dose 200 mg/kg, intraperitoneally), asiatic acid (30 mg/kg/day for 14 consecutive days, by oral gavage), or CYP plus asiatic acid, during which conscious cystometry, measurements of urothelium thickness and bladder edema, as well as selected biomarkers analyses were conducted. In rats that received asiatic acid together with CYP, a drop in bladder basal pressure, detrusor overactivity index, non-voiding contraction amplitude, non-voiding contraction frequency, and the area under the pressure curve were observed, when compared to the CYP group. Furthermore, a significant increase in threshold pressure, voided volume, intercontraction interval, bladder compliance, and volume threshold to elicit NVC were found in that group accordingly. Administration of the asiatic acid successfully restored concentrations of biomarkers both in bladder urothelium (BDNF, CGRP, OCT-3, IL-1β, IL-6, NGF, nitrotyrosine, malondialdehyde, TNF-α, SV2A, SNAP23, SNAP25, PAC-1, ORM1, occludin, IGFBP-3, HB-EGF, T–H protein, Z01, and HPX) and detrusor muscle (Rho kinase and VAChT) in CYP-treated rats. Finally, asiatic acid significantly decreased urothelium thickness and bladder oedema. Asiatic acid proved to be a potent and effective drug in the rat model of CYP-induced cystitis. 相似文献
76.
Marcin Pisarek Maria Janik-Czachor Tomasz Płociński Mariusz Łukaszewski 《Journal of Materials Science》2009,44(21):5701-5712
Rapidly quenched amorphous alloys—containing metallic or metalloid elements—are precursors for selective catalysts of many
technically important reactions. To increase their activity, various methods of material degradation occurring at the surface
and in the bulk of the rapidly quenched alloys have been used for promoting the catalytic performance of such materials. The
modifications of the structure, composition, and morphology of the substrate proved to be efficient in transforming inactive
metal alloy precursors into active and selective catalysts for hydrogenation, and dehydrogenation of organic compounds, as
well as for other processes like steam reforming of methanol. This article presents several examples of characterization of
such catalysts and discusses their selectivity and activity in a connection with physical and chemical properties of their
surfaces. Moreover, it is shown that scanning electron microscopy, Auger electron spectroscopy, scanning Auger microscopy,
and energy dispersive spectrometry allowed the local changes occurring during the activation process to be identified and
their implications for catalytic function to be considered. 相似文献
77.
Edyta Janik Marcin Niemcewicz Marcin Podogrocki Joanna Saluk-Bijak Michal Bijak 《International journal of molecular sciences》2021,22(11)
COVID-19 is a respiratory disease caused by newly discovered severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The disease at first was identified in the city of Wuhan, China in December 2019. Being a human infectious disease, it causes high fever, cough, breathing problems. In some cases it can be fatal, especially in people with comorbidities like heart or kidney problems and diabetes. The current COVID-19 treatment is based on symptomatic therapy, so finding an appropriate drug against COVID-19 remains an immediate and crucial target for the global scientific community. Two main processes are thought to be responsible for the COVID-19 pathogenesis. In the early stages of infection, disease is determined mainly by virus replication. In the later stages of infection, by an excessive immune/inflammatory response, leading to tissue damage. Therefore, the main treatment options are antiviral and immunomodulatory/anti-inflammatory agents. Many clinical trials have been conducted concerning the use of various drugs in COVID-19 therapy, and many are still ongoing. The majority of trials examine drug reposition (repurposing), which seems to be a good and effective option. Many drugs have been repurposed in COVID-19 therapy including remdesivir, favipiravir, tocilizumab and baricitinib. The aim of this review is to highlight (based on existing and accessible clinical evidence on ongoing trials) the current and available promising drugs for COVID-19 and outline their characteristics. 相似文献
78.
79.
This paper presents an approach to the modelling of transient thermal states in electronic circuits using an analytical solution of the heat equation. Fully three-dimensional analytical time dependent solutions are determined with the help of Green's functions. The solution method is illustrated in detail on a practical example, where the results of transient thermal simulations of a real hybrid circuit are compared with infrared measurements. 相似文献
80.
Marcin Janicki Marcin Daniel Michal Szermer Andrzej Napieralski 《Microelectronics Journal》2004,35(10):831-840
The proper design and simulation of modern electronic microsystems oriented towards environment monitoring requires accurate models of various ambient sensors. In particular, this paper presents a comprehensive model of an ion sensitive field effect transistor (ISFET). The model can be employed straightforwardly for simulations at device, circuit or system level.First, the model was validated with electrical measurements and simulations of real structures performed for different ion concentration and temperature values. Then, the ISFET sensor model was employed for mixed-signal simulations in VHDL-AMS, when the analysis of a microsystem consisting of the ISFET sensor and a sigma-delta analogue-to-digital converter was carried out. Additionally, the presence of other ions than hydrogen in the measured solution was also taken into account in the simulations. 相似文献