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International Soil and Water Conservation Research 2021年第2期9卷 229-240页

作者： piotr Kostencki Tomasz Stawicki Aleksandra Krolicka Department of Renewable Energy Engineering Faculty of Environmental Management and AgricultureWest Pomeranian University of Technology in SzczecinPapie_za Pawła VI Street 171-459SzczecinPoland Faculty of Mechanical Engineering Wrocław University of Science and TechnologySmoluchowskiego Street 2550-370WroclawPoland

For the manufacture of working parts of agricultural tools operating in soil,various structural materials are used:alloy and low-alloy steels,weld materials for hardfacing,and plates made from *** design new construction solutions to obtain components that are resistant to abrasive wear and *** components are subject to wear during soil cultivation,due to which wear products remain in the *** this work,the mass of chemical elements remaining in soil from materials used in selected working parts of agricultural tools intended for soil cultivation was *** the operation of the tested parts,it was found that the following elements were introduced into the soil:Al,B,C,Co,Cr,Cu,Fe,Mo,Nb,Ni,P,Pb,S,Si,Ti,V,Wand *** was introduced into the soil in the highest amount(15.907e222.004 g∙ha-1).Among the chemical elements reaching the soil,there were also elements that may pose a toxicological *** was found that the mass of chemical elements introduced into the soil depends on their content in the used structural materials and also on the conditions of cultivation,which determine the wear intensity of the parts.

关键词： Soil cultivation Working parts Potentially toxic elements Soil contamination Cemented-carbide Low-alloy steel

Overview of Identity Management

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China Communications 2008年第4期5卷 129-142页

作者： Marcin Dabrowski piotr Pacyna AGH University of Science and Technology

In recent years there has been a fast grow of various electronic *** service requires specif-ic credentials for authenticating and authorizing user ac-cess or specific subset of user's personal information for transactions the service *** a situation causes problems with remembering multiple,service-specific authentication data,with controlling user's personal data spread across different services-problems with managing user's *** paper is an overview on Identity Management(IdM).It introduces basic terms connected with IdM,shows current and emerging appli-cation areas,enumerates the most important IdM activi-ties,describes the most representative identity manage-ment specifications and frameworks and at the end,it points out important problems in identity management which need to be addressed in the near future.

关键词： Identity Digital identity Contextual iden-tity Identity management Identity federation Circle of trust

Architectural Approaches to Network and Service Access Authentication

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China Communications 2007年第3期4卷 4-16页

作者： Marcin Dabrowski piotr Pacyna AGH University of Science and Technology Poland AGH University of Science and Technology Poland Universidad Carlos Ⅲ de MadridSpain

Authentication is the first step,of central importance, for access control and for security protection in radio access networks.A general model for authentication was adopted from fixed networks and applied to the wireless ***,the differences in the operational environment between the fixed and the wireless world,heterogeneity of the radio communications systems,new trends in service provisioning, emerging business models and performance requirements raise the need to revisit the original requirements for authentication systems and to come up with schemes that better suit current *** this review paper we discuss authentication in singlehop radio access networks by characterizing the current as well as the emerging authentication schemes.

关键词： authentication access control wireless networks next-generation Internet

Experimental and Analytical Analysis of Perforated Plate Aerodynamics

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Journal of Thermal Science 2003年第3期12卷 193-197页

作者： JürgenZierep RainerBohning piotr Doerffer ISL Karlsruhe University Kaiserstr.12 D-76 128 Karsruhe GermanyISL Karlsruhe University Kaiserstr.12 D-76 128 Karsruhe GermanyIMP PAN Fiszera 14 PL-80 952 Gdansk Poland

Perforated walls and transpiration flow play an important role in aerodynamics due to an increasing interest in application of flow control by means of blowing and/or suction. An experimental study was carried out which has led to the determination of a transpiration flow characteristics in the form of a simple formula that is very useful in modelling such flows. In connection to this relation a method of 'aerodynamic porosity' determination has been proposed which is much more reliable than geometric description of the porosity. A theoretical analysis of the flow through a perforation hole was also carried out. The flow was considered as compressible and viscous. The gasdynamic analysis led us to a very similar result to the relation obtained from the experiment. The adequacy of the theoretical result is discussed in respect to the experiment.

关键词： transonic flow flow control transpiration flow perforated walls blowing and suction.

Liver steatosis correlates with iron overload but not with HFE gene mutations in chronic hepatitis C

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Hepatobiliary & Pancreatic Diseases International 2013年第4期12卷 377-384页

作者： Katarzyna Sikorska piotr Stalke Tomasz Romanowski Robert Rzepko Krzysztof piotr Bielawski Department of Infectious Diseases Medical University of GdanskSmoluchowskiego 18 80-214 Gdansk Poland Department of Biotechnology Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of GdanskKladki 24 80-822 Gdansk Poland Department of Pathology Medical University of GdanskDebinki 7 80-952 Gdansk Poland

BACKGROUND: Liver steatosis and iron overload, which are frequently observed in chronic hepatitis C (CHC), may contribute to the progression of liver injury. This study aimed to evaluate the correlation between liver steatosis and iron overload in Polish patients with CHC compared to non- alcoholic fatty liver disease (NAFLD) and HFE-hereditary hemochromatosis (HH) patients. METHODS: A total of 191 CHC patients were compared with 67 NAFLD and 21 HH patients. Liver function tests, serum markers of iron metabolism, cholesterol and triglycerides were assayed. The inflammatory activity, fibrosis, iron deposits and steatosis stages were assessed in liver specimens. HFE gene polymorphisms were investigated by PCR-RFLP. RESULTS: Liver steatosis was associated with obesity and diabetes mellitus. This disease was confirmed in 76/174 (44%) CHC patients, most of whom were infected with genotype 1. The average grade of steatosis was higher in NAFLD patients. CHC patients had significantly higher iron concentrations and transferrin saturations than NAFLD patients. Compared with CHC patients, HH patients had higher values of serum iron parameters and more intensive hepatocyte iron deposits without differences in the prevalence and intensity of liver steatosis. In the CHC group, lipids accumulation in hepatocytes was significantly associated with the presence of serummarkers of iron overload. No correlation between the HFE gene polymorphism and liver steatosis in CHC patients was found. CONCLUSIONS: Liver steatosis was diagnosed in nearly half of CHC patients, most of whom were infected with genotype 1. The intensity of steatosis was lower in CHC patients than that in NAFLD patients because of a less frequent diagnosis of metabolic syndrome. Only in CHC patients were biochemical markers of iron accumulation positively correlated with liver steatosis; these findings were independent of HFE gene mutations.

关键词： hepatitis C virus iron overload fatty liver hemochromatosis metabolic syndrome X

Potential of silicon carbide MOSFETs in the DC/DC converters for future HVDC offshore wind farms

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High Voltage 2017年第4期2卷 233-243页

作者： Thomas Lagier Philippe Ladoux piotr Dworakowski SuperGrid Institute 130rue Léon BlumVilleurbanneFrance LAPLACE Universitéde ToulouseCNRSINPTUPS2 rue Charles CamichelToulouseFrance Thomas

High-voltage direct current(HVDC)is more and more often implemented for long distance electrical energy transmission,especially for off-shore wind *** this study,a full DC off-shore wind farm,which requires a high-power and high-voltage DC/DC converter,is *** order to reduce the size of the converter,the trend is to increase operating *** carbide(SiC)metal–oxide–semiconductor field-effect transistors(MOSFETs)are becoming industrially available and give scope for the realisation of high-performance DC/DC converters based on modular *** study presents a prospective analysis of the potential of such devices in HVDC power *** the characteristics of Si insulated-gate bipolar transistor and SiC MOSFET power modules,two DC/DC converter topologies are compared in terms of losses and number of *** conclusion,a study of the efficiency based on converter energy loss is presented.

关键词： MOSFETs converter bipolar

Output constrained IMC controllers in control systems of electromechanical actuators

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Control Theory and Technology 2015年第3期13卷 245-255页

作者： piotr M.MARUSAK Suwat KUNTANAPREEDA Institute of Control and Computation Engineering Warsaw University of Technology Faculty of Engineering King Mongkut's University of Technology North Bangkok

Electromechanical actuators are widely used in many industrial applications. There are usually some constraints existing in a designed system. This paper proposes a simple method to design constrained controllers for electromechanical actuators. The controllers merge the ideas exploited in internal model control and model predictive control. They are designed using the standard control system structure with unity negative feedback. The structure of the controllers is relatively simple as well as the design process. The output constraint handling mechanism is based on prediction of the control plant behavior many time steps ahead. The mechanism increases control performance and safety of the control plant. The benefits offered by the proposed controllers have been demonstrated in real-life experiments carried out in control systems of two electromechanical actuators： a DC motor and an electrohydraulic actuator.

关键词： Constrained control internal model control (IMC) model predictive control (MPC) electromechanical actuators

Streamwise Vortex Interaction with a Horseshoe Vortex

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Journal of Thermal Science 2003年第4期12卷 304-309页

作者： piotr Doerffer Pawel Flaszynski Franco Magagnato IMP PAN Fiszera 14 PL-80 952 Gdansk PolandIMP PAN Fiszera 14 PL-80 952 Gdansk PolandFGS Karlsruhe University Kaiserstr.12 D-76 128 Karlsruhe Germany

How control in turbomachinery is very difficult because of the complexity of its fully 3-D flow structure. The authors propose to introduce streamwise vortices into the control of internal flows. A simple configuration of vortices was investigated in order to better understand the flow control methods by means of streamwise vortices. The research presented here concerns streamwise vortex interaction with a horseshoe vortex. The effects of such an interaction are significantly dependent on the relative location of the streamwise vortex in respect to the leading edge of the profile. The streamwise vortex is induced by an air jet. The horseshoe vortex is generated by the leading edge of a symmetric profile. Such a configuration gives possibility to investigate the interaction of these two vortices alone. The presented analysis is based on numerical simulations by means of N-S compressible solver with a two-equation turbulence model.

关键词： flow control horseshoe vortex streamwise vortex.

Nodular regenerative hyperplasia:Evolving concepts on underdiagnosed cause of portal hypertension

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World Journal of Gastroenterology 2011年第11期17卷 1400-1409页

作者： Marek Hartleb Krzysztof Gutkowski piotr Milkiewicz Department of Gastroenterology and Hepatology Medical University of Silesia40-752 KatowicePoland Liver Unit Pomeranian Medical University70-111 SzczecinPoland

Nodular regenerative hyperplasia(NRH)is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative *** may lead to the development of non-cirrhotic portal *** are no published systematic population studies on NRH and our current knowledge is limited to case reports and case *** may develop via autoimmune,hematological,infectious,neoplastic,or drug-related *** disease is usually asymptomatic,slowly or nonprogressive unless complications of portal hypertension *** diagnosis is made by histopathology,which demonstrates diffuse micronodular transformation without fibrous *** of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic *** the initial treatment is to address the underlying disease,ultimately the therapy is directed to the management of portal *** prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal *** this review we detail the epidemiology,pathogenesis,diagnosis,management,and prognosis of NRH.

关键词： Nodular regenerative hyperplasia Portal hypertension Comorbidities

Biomass gasification and Polish coal-fired boilers for process of reburning in small boilers

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Journal of Central South University 2013年第6期20卷 1623-1630页

作者： Hrycko piotr Lasek Janusz Matuszek Katarzyna Institute for Chemical Processing of Coal

Reburning was applied to Polish automatic coal-fired retort boiler (25 kW).The use of bio-syngas reduced NOx emissions from the boiler by over 25%,below the significant level of 200 mg/m3 .Reburning was carried out using an integrated system consisting of the boiler and a fixed-bed 60 kW (GazEla) gasification *** process gas was continuously introduced above the coal burner of the *** process parameters of the boiler and the gasifier were also measured and compared with the other *** NOx emissions from automatic and manually operated boilers were also presented.

关键词： NOx rebuming coal combustion biomass gasification