Wyniki wyszukiwania dla: hardy%20paradox
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Hard and Soft Modeling Tools and Approaches to Data and Information Management in Real-Life Projects and Systems : special issue editorial
PublikacjaOmówiono miękkie oraz twarde narzędzia służące do modelowania i symulacji przepływów dużych ilości danych oraz informacji. Przedstawiono mozliwości zastosowania tego typu narzędzi w funkcjonowaniu systemów rzeczywistych.
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Effect of Variation of Hard Segment Content and Graphene-Based Nanofiller Concentration on Morphological, Thermal, and Mechanical Properties of Polyurethane Nanocomposites
PublikacjaThis study describes the development of a new class of high-performance polyurethane elastomer nanocomposites containing reduced graphene oxide (RGO) or graphene nanoplatelets (GNP). Two types of polyurethane elastomers with different contents of hard segments (HS) were used as a polymer matrix. The developed nanocomposites were characterized by thermal analysis (DSC, TG), dynamic mechanical testing (DMA), hardness testing, mechanical...
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Hard and Soft Modeling Tools and Approaches to Data and Information Management in Real-Life Projects and Systems : special issue editorial
PublikacjaOmówiono różne metody modelowania w zakresie zarządzania danymi i informacją w złożonych systemach rzeczywistych. Podkreślono szczególnie znaczenie modelowania miękkiego w tym zakresie.
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Solid Phase Micro-Extraction, a Versatile and Handy Tool in Environmental Trace Organic Analysis, Gets a New Class of Coatings, Polymeric Ionic Liquids
PublikacjaSolid phase microextraction (SPME) fundamentals, characteristics and application are described. The special stress is put on characteristics of sorbents used as SPME fiber coatings. Description of commercially available fibers and the present-day trends in development of new sorbents for SPME are given. Discussion is focused on possibility of application of ionic liquids (IL) and polymeric ionic liquids (PIL) as SPME fiber coatings....
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The influence of synthetic polyhydroxybutyrate on selected properties of novel polyurethanes for medical applications. Part I. Polyurethanes with aromatic diisocyanates in hard segments
PublikacjaZsyntetyzowano poliuretany (PUR) z udziałem 37% segmentu sztywnego uzyskanego na etapie przedłużania łańcucha prepolimeru w reakcji 4,4â-diizocyjanianu difenylometanu (MDI) z 1,4-butanodiolem (1,4-BD). Segmenty giętkie wytworzonych PUR były zbudowane z poli([R,S]-3--hydroksymaoelanu) (a-PHB) i polikaprolaktonodiolu (PCL) lub z a-PHB i polioksytetrametylenodiolu(PTMG). Zbadano wpływ obecności w łańcuchu PUR syntetycznego a-PHB...
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Fabrication of wormhole-like YSZ and Ni-YSZ by the novel soft-hard template CTAB/NaCl-assisted route. Suppressing Ni coalescence in SOFC
PublikacjaA novel one-pot synthesis route leading to the formation of a wormhole-like structure was developed for the successful fabrication of porous YSZ and Ni-YSZ systems. This method involved co-precipitation in the presence of the micelle-forming agents CTAB/Pluronic P123 and crystallising NaCl. The obtained skeletons were mechanically stable and presented almost 50% uniform, open porosity without using any additional pore-formers....
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Revisiting the estimation of cutting power with different energetic methods while sawing soft and hard woods on the circular sawing machine: a Central European case
PublikacjaIn the classical approaches, used in Central Europe in practice, cutting forces and cutting power in sawing processes of timber are commonly computed by means of the specific cutting resistance kc. It needs to be highlighted that accessible sources in handbooks and the scientific literature do not provide any data about wood provenance, nor about cutting conditions, in which cutting resistance has been empirically determined. In...
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Structure versus hydrolytic and thermal stability of bio-based thermoplastic polyurethane elastomers composed of hard and soft building blocks with high content of green carbon
PublikacjaNowadays, sustainability plays a key role in the design and synthesis of new materials. One of the methods for the preparation of green materials is incorporation into their structure the monomers with a high content of green carbon. Therefore, the aim of this work was to investigate the influence of the type and molecular mass of two bio-based polyester polyols and bio-glycol on the properties of aliphatic partially bio-based...
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Eco-friendly Route for Thermoplastic Polyurethane Elastomers with Bio-based Hard Segments Composed of Bio-glycol and Mixtures of Aromatic–Aliphatic and Aliphatic–Aliphatic Diisocyanate
PublikacjaApplication of bio-based diisocyanates with low volatility instead petrochemical diisocyanates has positive impact on environment by reduction of hazardous effects on living organisms and lead to bio-based polyurethanes (bio-PUs) with good usage properties. This work was focused on the synthesis and chosen properties examination of partially bio-based thermoplastic polyurethane elastomers (bio-PUs) obtained using diisocyanate mixtures,...
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INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
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Wpływ współczynnika promienia walca i stosunku grubości warstw na odkształ- cenie warstwy twardej. The influence of radius of rolls coefficient and re-lations of thickness layers at the deformation of hard layers of bimetalic plate
PublikacjaW pracy przedstawiono analizę numeryczną walcowania blachy platerowanej 18 G2A i 0H18N10T. Wytwarzanie blach dwuwarstwowych jest procesem trudnym do rozwiązania na drodze teoretycznej. Do analizy procesu wykorzystano program Forge 2 oparty na teorii elementów skończonych. Artykuł przedstawia wpływ wartości współczynnika promienia walcaH/R i stosunku grubości warstw HT/HM na charakter rozkładu odkształceń blachy dwuwarstwowej.
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Harry R. Moody and Jennifer R. Sasser (2012). Aging: Concepts and Controversies (7th edition). Los Angeles, London, New Delhi, Singapore and Washington, DC: Sage Publications, 576 pp. ISBN 978 1 4522 0309 6 (paperback)
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Algorytmy Optymalizacji Dyskretnej - ed. 2021/2022
Kursy OnlineIn real-world applications, many important practical problems are NP-hard, therefore it is expedient to consider not only the optimal solutions of NP-hard optimization problems, but also the solutions which are “close” to them (near-optimal solutions). So, we can try to design an approximation algorithm that efficiently produces a near-optimal solution for the NP-hard problem. In many cases we can even design approximation algorithms...
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Dedicated scheduling of tasks to minimize mean flow time
PublikacjaThis paper investigates the complexity of scheduling biprocessor tasks on dedicated processors to minimize mean flow time. Since the general problem is strongly NP-hard, we assume some restrictions on task lengths and the structure of associated scheduling graphs. Of particular interest are acyclic graphs. In this way we identify a borderline between NP-hard and polynomially solvable special cases.
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Effect of Soft Handover on the Capacity of WCMDA/FDD Interfece Using MRC RAKE Receiver in Uplink
PublikacjaIn the paper the mechanism of soft and hard hanover in UMTS is presented. Simulation tests for different services having various performance requirements and transmission rates have beeen made. Simulation results showing effect of soft handover in comparison with hard handover on the capacity of WCMDA/FDD radio interfaceare described, when the RAKE receiver with Maximal Ratio Combining has been implemented in RNC.
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Degradable poly(ester-ether) urethanes of improved surface calcium deposition developed as novel biomaterials
PublikacjaBones, which are considered as hard tissues, work as scaffold for human body. They provide physical support for muscles and protect intestinal organs. Percentage of hard tissues in human body depends on age, weight, and gender. Human skeleton consists of 206 connected bones. Therefore, it is natural that the hard-tissue damage such as fractures, osteoporosis, and congenital lack of bone may appear. The innovative way of bone healing...
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Ball on disk test AL(rf.)-Al2O3-r25
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 25 mm. Disk material: Al6061 not treated (reference).
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Ball on disk test AL(rf.)-Al2O3-r15
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 15 mm. Disk material: Al6061 not treated (reference).
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Ball on disk test AT4_11-Al2O3-r25
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 25 mm. Disk material: Al6061 TiN powder injected (AT4_11).
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Ball on disk test AT3_21-Al2O3-r25
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 25 mm. Disk material: Al6061 TiN powder injected (AT3_21).
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Ball on disk test AW4_1-Al2O3-r15
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 15 mm. Disk material: Al6061 WC powder injected (AW4_1).
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Ball on disk test AT4_4-Al2O3-r15
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 15 mm. Disk material: Al6061 TiN powder injected (AT4_4).
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Ball on disk test AW4_11-Al2O3-r25
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 25 mm. Disk material: Al6061 WC powder injected (AW4_11).
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Ball on disk test AT4_1-Al2O3-r15
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 15 mm. Disk material: Al6061 TiN powder injected (AT4_1).
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Ball on disk test AT4_41-Al2O3-r25
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 25 mm. Disk material: Al6061 TiN powder injected (AT4_41).
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Ball on disk test AT3_2-Al2O3-r15
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 15 mm. Disk material: Al6061 TiN powder injected (AT3_2).
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Ball on disk test AW4_4-Al2O3-r15
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 15 mm. Disk material: Al6061 WC powder injected (AW4_4).
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Ball on disk test AW4_41-Al2O3-r25
Dane BadawczeHard particle reinforced Al6061 alloy testing. Laser remelting and kinetic injection of particulate material. Ball on disc tribological test. Ball material: Al2O3. Ball diameter: 5 mm. Sliding path radius: 25 mm. Disk material: Al6061 WC powder injected (AW4_41).
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Artificial intelligence and productivity: global evidence from AI patent and bibliometric data
PublikacjaIn this paper we analyse the relationship between technological innovation in the artificial intelligence (AI) domain and macroeconomic productivity. We embed recently released data on patents and publications related to AI in an augmented model of productivity growth, which we estimate for the OECD countries and compare to an extended sample including non-OECD countries. Our estimates provide evidence in favour of the modern productivity...
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Logistyka twarda HL jako element przewagi konkurencyjnej w sferze dystrybucji
PublikacjaLogistyka została zdefiniowana jako dwuskładnikowa: miękka SL (Soft Logist) oraz twarda HL (Hard Logist). Przedstawiono zakres kompetencyjny oraz podano przykłady.
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Paired domination versus domination and packing number in graphs
PublikacjaGiven a graph G = (V(G), E(G)), the size of a minimum dominating set, minimum paired dominating set, and a minimum total dominating set of a graph G are denoted by γ (G), γpr(G), and γt(G), respectively. For a positive integer k, a k-packing in G is a set S ⊆ V(G) such that for every pair of distinct vertices u and v in S, the distance between u and v is at least k + 1. The k-packing number is the order of a largest kpacking and...
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Artificial intelligence and productivity: global evidence from AI patent and bibliometric data .
PublikacjaIn this paper we analyse the relationship between technological innovation in the artificial intelligence (AI) domain and macroeconomic productivity. We embed recently released data on patents and publications related to AI in an augmented model of productivity growth, which we estimate for the OECD countries and compare to an extended sample including non-OECD countries. Our estimates provide evidence in favour of the modern...
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Thermal and mechanical properties of (W,Zr)B2-z coatings deposited by RF magnetron sputtering method
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The Roughness of the Hardened Steel Surface Created by the Rolling-Burnishing Process
PublikacjaBurnishing hard materials can be used as an alternative finishing process. this paper presents the results of burnishing hardened steel. The article discusses surface deformation that occurs during this process and depends on the selected parameters of the geometric structure of the force applied for surface burnishing.
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Central-force decomposition of spline-based modified embedded atom method potential
PublikacjaCentral-force decompositions are fundamental to the calculation of stress fields in atomic systems by means of Hardy stress. We derive expressions for a central-force decomposition of the spline-based modified embedded atom method (s-MEAM) potential. The expressions are subsequently simplified to a form that can be readily used in molecular-dynamics simulations, enabling the calculation of the spatial distribution of stress in...
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The Impact of Isocyanate Index and Filler Functionalities on the Performance of Flexible Foamed Polyurethane/Ground Tire Rubber Composites
PublikacjaThe structure and performance of polyurethane (PU) foams are strongly driven by the stoichiometry of the polyaddition reaction, quantitatively described by the isocyanate index. It determines the balance between isocyanate and hydroxyl groups in the reacting system and is affected by the introduction of additional functionalities originated, e.g., from applied fillers. Nevertheless, this issue is hardly taken into account in research...
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Edge and Pair Queries-Random Graphs and Complexity
PublikacjaWe investigate two types of query games played on a graph, pair queries and edge queries. We concentrate on investigating the two associated graph parameters for binomial random graphs, and showing that determining any of the two parameters is NP-hard for bounded degree graphs.
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From dolomite waste to katoite-based binder: Synthesis, performance and characterization
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Utility of Inflammatory Markers in Detection of Perioperative Morbidity After Laparoscopic Sleeve Gastrectomy, Laparoscopic Roux-en-Y Gastric Bypass, and One-Anastomosis Gastric Bypass—Multicenter Study
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The structure of electricity production in Poland (data as at the end of 2010)
Dane BadawczeThe energy market in Poland is characterized primarily by the use of only one raw material for the production of electricity. In 2010, as much as 91.4% of electricity was produced on the basis of hard coal or lignite. Therefore, the remaining sources used for the production of electricity participated in the production of electricity to a small extent....
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Wpływ posuwu nagniatania na chropowatość powierzchni przedmiotów ze stali w stanie utwardzonym
PublikacjaPrzedstawiono wyniki badań eksperymentalnych procesu nagniatania stali twardej (62 HRC) narzędziem ceramicznym (kulką) z dociskiem hydrostatycznym. Analizowano wpływ posuwu nagniatania oraz parametrów poprzedzającej obróbki toczeniem na twardo na stan powierzchni opisanej wybranymi parametrami chropowatości.
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Thermoplastic polyurethanes derived from petrochemical or renewable resources: A comprehensive review
PublikacjaThermoplastic polyurethanes (TPUs) materials are obtained by the reaction of polyol (ether-, ester-, and carbonate-based diols with average molecular weight in the range from 1,000 to 3,000 g/mol) with aliphatic or aromatic diisocyanates. Synthesized materials consist of the hard and soft segments which are separated in different level. All mechanical and thermal properties of TPUs depend on the chemical structure of used monomers,...
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Type 2 Diabetes Remission 5 Years After Laparoscopic Sleeve Gastrectomy: Multicenter Cohort Study
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Pounding between high-rise buildings founded on different soil types
PublikacjaEarthquake-induced pounding is a phenomenon that has been often experienced in previous earthquakes. The aim of this study is to investigate the effect of the soil type on high-rise buildings experiencing earthquake induced-pounding. Pounding between 7-storey and 9-storey buildings is examined under five soil types defined in the ASCE 7-10 code which are hard rock, rock, very dense soil and soft rock, stiff soil and soft clay soil....
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Surface Texture Analysis of Hardened Shafts after Ceramic Ball Burnishing
PublikacjaThis article represents the results of testing the surface condition of shafts manufactured by the burnishing process. The shafts with a hardness of approximately 62 HRC (Rockwell C). were burnished with a ceramic ball (Si3N4), where the force range was controlled by the means of a hydraulic system. The machining process consisted of hard turning shafts with cubic boron nitride (CBN) inserts, followed by burnishing with the use...
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Sharp bounds for the complexity of semi-equitable coloring of cubic and subcubic graphs
PublikacjaIn this paper we consider the complexity of semi-equitable k-coloring of the vertices of a cubic or subcubic graph. We show that, given n-vertex subcubic graph G, a semi-equitable k-coloring of G is NP-hard if s >= 7n/20 and polynomially solvable if s <= 7n/21, where s is the size of maximum color class of the coloring.
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Equitable coloring of graphs. Recent theoretical results and new practical algorithms
PublikacjaIn this paper we survey recent theoretical results concerning conditions for equitable colorability of some graphs and recent theoretical results concerning the complexity of equitable coloring problem. Next, since the general coloring problem is strongly NP-hard, we report on practical experiments with some efficient polynomial-time algorithms for approximate equitable coloring of general graphs.
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Liquid residence time in vortex separators
PublikacjaCentrifugal force enhances gravitational separation of suspension (vortex separators), as well as allows regulation of liquid discharge (vortex flow controls). Furthermore, it elongates the effective residence time of liquid inside the chamber in comparison to non-circulative flow. Laboratorz measurements, described in the paper, indicate that average liquid residence time for circulative flow exceeds 50% of plug-flow time,...
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The influence of drying parameters on wood properties
PublikacjaThe influence of drying conditions on wood properties is presented. The classical approach was used to determine energetic effects (cutting forces and cutting power) of wood sawing process on the basis of the wood specific cutting resistance, material constant. Before mashining wood material (soft and hard) was dryied at various conditions using air at 25oC, air-steam meaxture at 80oC and steam at 110oC.
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Just look at to open it up: A biometric verification facility for password autofill to protect electronic documents
PublikacjaElectronic documents constitute specific units of information, and protecting them against unauthorized access is a challenging task. This is because a password protected document may be stolen from its host computer or intercepted while on transfer and exposed to unlimited offline attacks. The key issue is, therefore, making document passwords hard to crack. We propose to augment a common text password authentication interface...