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Determination of the Influence of c-BN+h-BN Coating Structure on Brittleness

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材料热处理学报 2004年第05B期25卷 888-893页

作者： Maciej Kupczyk Adam Lejwoda przemyslaw Cieszkowski przemyslaw Libuda Poznan University of Technology Institute of Mechanical Engineering Poznan PolandPoznan University of Technology Institute of Mechanical Engineering Poznan PolandPoznan University of Technology Institute of Mechanical Engineering Poznan PolandPoznan University of Technology Institute of Mechanical Engineering Poznan Poland

In the article is presented the brittleness study of boron nitride coatings deposited on cutting edges made of cemented carbides by the pulse-plasma method (PPD). Influences of the structure (density, pores, microcracks) of coating material on the brittleness and on selected technological parameters of boron nitride formation by PPD method particularly taking into account discharge voltage on brittleness are shown. Differences between values of both ai(300) and "1(5oo) coefficients characterized susceptibility to coatings cracking of investigated coating manufactured using different values of discharge voltage were defined. Results of an investigations have been confirmed usefulness of Palmqvist’s method for measurement of coating susceptibility to brittle cracking.

关键词：耐磨覆层 PVD 脆性氮化硼涂层

Computational Modelling of Retrofitting a Coal Fired Boiler Type OP-230 for Predicting NOX Reduction

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Journal of Thermal Science 2018年第5期27卷 433-439页

作者： MOTYL przemyslaw LACH Jan Faculty of Mechanical Engineering Kazimierz Pulaski University of Technology and Humanities in RadomRadom 26-600poland Faculty of Engineering Management Bialystok University of TechnologyKleosin 16-001 Poland

This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to determine whether the boiler can be retrofitted for the fulfilment of the prospective environmental protection regulations relating to levels of NO_X emissions. The improvement of the air staging via the dual-fuel technique was based on the indirect co-firing technology. The impact of two arrangements of dedicated syngas nozzles(below and above the existing coal burners), two syngas compositions and two heat replacements(5% and 15%) on the course of thermal processes in a furnace was tested. The reductions in NO_X emissions were predicted relative to the baseline when only coal is combusted. The highest reduction of about 38% was achieved with the syngas nozzles below the existing coal burners and 15% heat replacement. This arrangement of nozzles offers the residence time sufficient to co-fire coal with waste derived syngas. A lower reduction in NO_X emissions was obtained with the nozzles above the burners as the enlargement of local fuel rich zone near syngas injection becomes significant for 15% heat replacement. Results provide for the decreasing impact of methane content along with the increase of syngas heat input. The avoided CO_2 emissions through the syngas indirect co-firing with coal in the boiler are linear function of heat replacements.

关键词： boiler modelling co-firing biomass derived syngas NOX emission retrofitting

The Almost Sure Central Limit Theorems for the Maxima of Sums under Some New Weak Dependence Assumptions

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Acta Mathematica Sinica,English Series 2013年第3期29卷 429-448页

作者： Marcin DUDZINSKI przemyslaw GORKA Faculty of Applied Informatics and Mathematics Warsaw University of Life Sciences (SGGW) Department of Mathematics and Information Sciences Warsaw University of Technology

We prove the almost sure central limit theorems for the maxima of partial sums of r.v.＇s under a general condition of dependence due to Doukhan and Louhichi. We will separately consider the centered sequences and the... 详细信息

关键词： Almost sure central limit theorem new weakly dependent random variables maxima ofpartial sums Markov chains

Recent Advances in High Pressure and Temperature Rheological Studies

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Journal of Earth Science 2010年第5期21卷 495-516页

作者： Nadege Hilairet przemyslaw Dera Center for Advanced Radiation Sources The University of Chicago 5640 South Ellis Avenue Chicago Illinois 60637 USA

Rheological studies at high pressure and temperature using in-situ X-ray diffraction and imaging have made significant progresses in recent years, thanks to a combination of recent developments in several areas：（1） advances in synchrotron X-ray techniques, （2） advances in deformation devices and the abilities to control pressure, temperature, stress, strain and strain rates, （3） theoretical and computational advances in stress determination based on powder and single crystal diffraction, （4） theoretical and computational advances in modeling of grain-level micromcchanics based on elasto-plastic and visco-plastic self-consistent formulations. In this article, we briefly introduce the experimental techniques and theoretical background for in-situ high pressure, high temperature rheological studies, and then review recent studies of rheological properties of major mantle materials. Some currently encountered issues have prompted developments in single-crystal quasi-Laue diffraction for complete stress tensor determination and textural evolution of poly-phased composites based on X-ray microtomography. Future prospects are discussed.

关键词： rheology deformation composite synchrotron radiation high pressure and high temperature diffraction tomography.

Influence of increasing numbers of RE-inverters on the powerquality in the distribution grids： A PQ case study of arepresentative wind turbine and photovoltaic system

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Frontiers in Energy 2017年第2期11卷 155-167页

作者： przemyslaw JANIK Grzegorz KOSOBUDZKI Harald SCHWARZ Brandenburg University of Technology 01968 Cottbus-SenflenbergGermany Department of Electrical Engineering Wroclaw University of Scienceand Technology 50-370 Wroclaw Poland Department for Energy Distribution and High Voltage Engineering Brandenburg University of Technology 01968 Cottbus-SenftenbergGermany

This paper presents the selected power quality (PQ) indicia of a wind generator and a photovoltaic installation considered to be the representative of medium voltage and low voltage distribution grids. The analysis of measured values suggests that the decrease in PQ is a case of specific combination of distributed generation, grid parameters and load behaviour. Modern generators have a limited impact on PQ. On the other hand, fluctuations in power generation are regarded as an emerging PQ indicator. The growing number of distributed renewable installations causes stochastic, variable, and hardly predictable power flows in the distribution grid. The nature of fluctuations in wind and solar generation is different. In both cases, new indexes for the quantification of fluctuations are needed and are yet not standardised. Proper assessment of these fluctuations enables definition of useful fluctuation limits and rules for optimal storage system integration.

关键词： power quality harmonics sags photovoltaic(PV) system doubly feed induction generator (DFIG) inverters

NONPARAMETRIC IDENTIFICATION OF MISO HAMMERSTEIN SYSTEM FROM STRUCTURED DATA

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Journal of Systems Science and Systems Engineering 2015年第1期24卷 68-80页

作者： Pawel Wachel przemyslaw liwiński Zygmunt Hasiewicz Department of Control Systems and Mechatronics Wroclaw University of Technology

The problem of nonparametric identification of a multivariate nonlinearity in a D-input Hammer- stein system is examined. It is demonstrated that if the input measurements are structured, in the sense that there exists some hidden relation between them, i.e. if they are distributed on some （unknown） d-dimensional space M in IRD, d 〈 D, then the system nonlinearity can be recovered at points on M with the convergence rate O（n-1/（2＋d）） dependent on d. This rate is thus faster than the generic rate O（n-1/（2＋D）） achieved by typical nonparametric algorithms and controlled solely by the number of inputs D.

关键词： MISO Hammerstein system nonparametric system identification structured data conver-gence rate

Passive radiant cooling without sacrificing the aesthetics of objects

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Light(Science & Applications) 2022年第7期11卷 1339-1340页

作者： przemyslaw Jacek Dereń Institute of Low Temperature and Structure Research PAS ul.Okólna 2WroclawPoland

Photonic-engineered passive radiative cooling built into decorative climate-controlled enclosures reduces the active power consumption of the existing enclosure without sacrificing its aesthetics.

关键词： icing radiative enclosure

Redesigning the Model of Book Evaluation in the Polish Performance-based Research Funding System

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Journal of Data and Information Science 2018年第4期3卷 61-73页

作者： Emanuel Kulczycki przemyslaw Korytkowski Adam Mickiewicz University in Poznań Poland West Pomeranian University of Technology in Szczecin Poland

Purpose: This study aims to present the key systemic changes in the Polish book evaluation model to focus on the publisher list, as inspired by the Norwegian Model. Design/methodology/approach: In this study we reconstruct the framework of the 2010 and 2018 models of book evaluation in Poland within the performance-based research funding system. Findings: For almost 20 years the book evaluation system in Poland has been based on the verification of various technical criteria(e.g. length of the book). The new 2018 model is based on the principle of prestige inheritance(a book is worth as much as its publisher is) and is inspired by the publisher list used in the Norwegian Model. In this paper, we argue that this solution may be a more balanced policy instrument than the previous 2010 model in which neither the quality of the publisher nor the quality of the book played any role in the *** limitations: We work from the framework of the 2018 model of book evaluation specified in the law on higher education and science from 20 July 2018, as implementation acts are not available yet. Practical implications: This study may provide a valuable point of reference on how structural reforms in the research evaluation model were implemented on a country level. The results of this study may be interesting to policy makers, stakeholders and researchers focused on science policy. Originality/value: This is the very first study that presents the new framework of the Polish research evaluation model and policy instruments for scholarly book evaluation. We describe what motivated policy makers to change the book evaluation model, and what arguments were explicitly raised to argue for the new solution.

关键词： Book evaluation Norwegian Model Performance-based research funding system Poland Publisher list

Cadmium and lead toxicity and bioaccumulation in Microcystis aeruginosa

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Frontiers of Environmental Science & Engineering 2014年第3期8卷 427-432页

作者： Piotr RZYMSKI Barbara PONIEDZIALEK przemyslaw NIEDZIELSKI Piotr TABACZEWSKI Krzysztof WIKTOROWICZ Department of Biology and Environmental Protection Poznan University of Medical Sciences Poznan 61-848 Poland Faculty of Chemistry Department of Water and Soil Analysis Adam Mickiewicz University Poznan 61-614 Poland

The growth of human population leads to intensification of agriculture and promotes, through eutrophication, development of cyanobacteria. One of the most widespread and bloom-forming species in freshwater is toxic Microcystis aeruginosa （M. aeruginosa）. Combustion of fossil fuels and metallurgical processes are the main sources of heavy metals contamination in surface water including cadmium （Cd） and lead （Pb）. The following study was conducted in order to determine the effect of 1- 20 mg. L-1 of Cd and Pb on photochemistry （using flow cytometry） and growth （based on chlorophyll concentra- tion） ofM. aeruginosa as well as to estimate levels of metal bioaccumulation. We have found that 1-10mg.L-1 of Cd and 1-5 rag. L1 of Pb induced continuous enhancement of chlorophyll fluorescence during 24 h of incubation. No significant degradation of chlorophyll was observed in these samples. At higher concentrations of 20 mg. L-1 of Cd and 10-20 mg.L-1 of Pb chlorophyll level significantly decreased and its fluorescence was quenched. M. aeruginosa demonstrated high capability of Cd and Pb bioaccumulation, proportionally to initial metal concentration. In samples with initial concentration of 20 mg. L-1 of Cd and Pb bioaccumulation of 87.3% and 90.1% was observed, respectively. Our study demonstrates that M. aeruginosa can potentially survive in highly metals polluted environments, be a primary source of toxic metals in the food chain and consequently contribute to enhanced toxicity of heavy metals to living organisms including human.

关键词： Microcystis aeruginosa heavy metals bioac-cumulation chlorophyll flow cytometry