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Search results for: flag manifold
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Badania porównawcze docierania powierzchni płaskich elementów miedzianych, ceramicznych i z węglików spiekanych = Comparative research of lapping of flat surfaces of parts made from copper, ceramics and sintered carbides
PublicationPrzedstawiono badania porównawcze jakości i intensywności docierania elementów miedzianych, ceramicznych i z węglików spiekanych. Analizowano skażenie powierzchni miedzi ścierniwem oraz porównano mechanizmy usuwania materiału w przypadku obróbki metali i ceramiki.
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Improved Uniform Sampling in Constrained Domains for Data-Driven Modelling of Antennas
PublicationData-driven surrogate modelling of antenna structures is an attractive way of accelerating the design process, in particular, parametric optimization. In practice, construction of surrogates is hindered by curse of dimensionality as well as wide ranges of geometry parameters that need to be covered in order to make the model useful. These difficulties can be alleviated by constrained performance-driven modelling with the surrogate...
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Enhanced uniform data sampling for constrained data‐driven modeling of antenna input characteristics
PublicationData-driven surrogates are the most popular replacement models utilized in many fields of engineering and science, including design of microwave and antenna structures. The primary practical issue is a curse of dimensionality which limits the number of independent parameters that can be accounted for in the modelling process. Recently, a performance-driven modelling technique has been proposed where the constrained domain of the...
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t-SNE Highlights Phylogenetic and Temporal Patterns of SARS-CoV-2 Spike and Nucleocapsid Protein Evolution
PublicationWe propose applying t-distributed stochastic neighbor embedding to protein sequences of SARS-CoV-2 to construct, visualize and study the evolutionary space of the coronavirus. The basic idea is to explore the COVID-19 evolution space by using modern manifold learning techniques applied to evolutionary distances between variants. Evolutionary distances have been calculated based on the structures of the nucleocapsid and spike proteins.
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Theory versus experiment for vacuum Rabi oscillations in lossy cavities
PublicationThe 1996 experiment by Brune et al. [Phys. Rev. Lett. 76, 1800 (1996)] on vacuum Rabi oscillation is analyzed by means of alternative models of atom-reservoir interaction. Agreement with experimental Rabi oscillation data can be obtained if one defines jump operators in the dressed-state basis and takes into account thermal fluctuations between dressed states belonging to the same manifold. Such low-frequency transitions could...
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New perspective on the in vivo use of cold stress dynamic thermography in integumental reconstruction with the use of skin-muscle flaps
PublicationAmong the problems encountered by plastic surgeons is the reconstruction of defects following tumors. One of the reconstructive options is TRAM flap. Despite that anatomy is well-explored, marginal flap necrosis may develop. To minimize complications imaging examinations was designed to determine the degree of flap perfusion. One of them is the thermographic examination.
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TRAVELLING WAVES FOR LOW–GRADE GLIOMA GROWTH AND RESPONSE TO A CHEMOTHERAPY MODEL
PublicationLow-grade gliomas (LGGs) are primary brain tumours which evolve very slowly in time, but inevitably cause patient death. In this paper, we consider a PDE version of the previously proposed ODE model that describes the changes in the densities of functionally alive LGGs cells and cells that are irreversibly damaged by chemotherapy treatment. Besides the basic mathematical properties of the model, we study the possibility of the...
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Influence of pH and low-molecular weight organic compounds in solution on selected spectroscopic and analytical parameters of flowing liquid anode atmospheric pressure glow discharge (FLA-APGD) for the optical emission spectrometric (OES) determination of Ag, Cd, and Pb
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A Compact Basis for Reliable Fast Frequency Sweep via the Reduced-Basis Method
PublicationA reliable reduced-order model (ROM) for fast frequency sweep in time-harmonic Maxwell’s equations by means of the reduced-basis method is detailed. Taking frequency as a parameter, the electromagnetic field in microwave circuits does not arbitrarily vary as frequency changes, but evolves on a very low-dimensional manifold. Approximating this low-dimensional manifold by a low dimension subspace, namely, reduced-basis space, gives...
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Thermal sequences database of the skin flaps in breast reconstruction and burns
PublicationThis paper presents a database of Active Dynamic Thermography (ADT) thermal sequences gathered throughout 6 year study on ADT application in skin flap blood perfusion monitoring and burn wounds diagnosis. For skin flap monitoring the database comprises of data collected during three different breast reconstruction procedures. The patients were monitored pre, intra and post surgically within 90 days period. The sequences were used...
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Thermal sequences database of the skin flaps in breast reconstruction and burns
PublicationThis paper presents a database of Active Dynamic Thermography (ADT) thermal sequences gathered throughout 6 year study on ADT application in skin flap blood perfusion monitoring and burn wounds diagnosis. For skin flap monitoring the database comprises of data collected during three different breast reconstruction procedures. The patients were monitored pre, intra and post surgically within 90 days period. The sequences were used...
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Estimation of the minimal number of periodic points for smooth self-maps of odd dimensional real projective spaces
PublicationLet f be a smooth self-map of a closed connected manifold of dimension m⩾3. The authors introduced in [G. Graff, J. Jezierski, Minimizing the number of periodic points for smooth maps. Non-simply connected case, Topology Appl. 158 (3) (2011) 276-290] the topological invariant NJD_r[f], where r is a fixed natural number, which is equal to the minimal number of r-periodic points in the smooth homotopy class of f. In this paper smooth...
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Differential Scanning Calorimetry for Determining the Thermodynamic Properties of Selected Honeys
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A High-Efficient Measurement System With Optimization Feature for Prototype CMOS Image Sensors
PublicationIn this paper, a gray-scale CMOS image sensor (CIS) characterization system with an optimization feature has been proposed. By using a very fast and precise control of light intensity, based on the pulsewidth-modulation method, it is avoided to measure the illuminance every time. These features accelerate the multicriteria CIS optimization requiring many thousands of measurements. The system throughput is 2.5 Gb/s, which allows...
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EXHAUST GAS TEMPERATURE MEASUREMENTS IN DIAGNOSTICS OF TURBOCHARGED MARINE INTERNAL COMBUSTION ENGINES PART II DYNAMIC MEASUREMENTS
PublicationThe second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy) in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment...
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Layer-by-layer polymer deposited fabrics with superior flame retardancy and electrical conductivity
PublicationSmart and multifunctional textiles and fabrics are progressively developing, such that multifunctional fabrics are becoming more widespread. We elaborated herein multi-layered flax fabrics with superior flame retardancy and conductivity, which revealed fireproof feature while keeping conductivity during burning. The flax fabric was reinforced by layer-by-layer (LbL) deposition of sodium polyacrylate (SPA), polyethylenimine (PEI),...
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Geometry Parametric Model Order Reduction with Randomly Generated Projection Bases
PublicationIn this work, a reduced-order model for geometry parameters and fast frequency sweep is proposed. The Finite Element Method is used to solve time-harmonic Maxwell’s equations. Taking into account the electromagnetic field does not arbitrarily vary as a function of frequency and geometry parameters, a low dimension system manifold is identified. Thus, the original Finite Element problem can be approximated by a model of reduced...
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Constructive Controllability for Incompressible Vector Fields
PublicationWe give a constructive proof of a global controllability result for an autonomous system of ODEs guided by bounded locally Lipschitz and divergence free (i.e. incompressible) vector field, when the phase space is the whole Euclidean space and the vector field satisfies so-called vanishing mean drift condition. For the case when the ODE is defined over some smooth compact connected Riemannian manifold, we significantly strengthen...
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Inverse shadowing and related measures
PublicationWe study various weaker forms of the inverse shadowing property for discrete dynamical systems on a smooth compact manifold. First, we introduce the so-called ergodic inverse shadowing property (Birkhoff averages of continuous functions along an exact trajectory and the approximating one are close). We demonstrate that this property implies the continuity of the set of invariant measures in the Hausdorff metric. We show that the...
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Local Nusselt number evaluation in the case of jet impingement
PublicationJet impingement still is one of demanding cases regarding computational fluid dynamics, due to its highly turbulent behaviour, with occurrence of turbulent-laminar transition. Even recently developed methods exhibit some drawbacks – RANS based simulations lack accuracy, LES and DNS based ones require too much computational time. Hybrid methods also exist, but their development and validation is in progress. Nevertheless, CFD application...
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A Multi Rig Screening Test for Thin Ceramic Coatings in Bio - Tribological Applications
PublicationA method is presented for the comparative testing of wear resistance of ceramic coatings made from materials potentially feasible in tribo - medical applications, mainly orthopaedic implants made from ceramics coated metals for low cost, long life and low wear particle emission into the body. The method was devised as the main tool for use in research and is comprised of flat on flat and ball on flat surface (sliding) tests. Seven...
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Flow distribution and heat transfer in minigap and minichannel heat exchangers during flow boiling
PublicationThe topic of boiling heat transfer in miniscale geometries has focused the ever increasing interest of researchers in recent years. However, most of the works are related to mini- and microchannels and much less to minigaps. Meanwhile, minigaps allow for more comprehensive experimental studies, i.e. flow visualisations due to the flat, two-dimensional configuration of the flow. The results of the experimental investigations of...
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WEAR OF Si OR B DOPED AMORPHOUS CARBON COATINGS
PublicationThe paper describes a complex wear research on DLC (amorphous carbon) moped with boron (B) and silicone (Si). The tests were carried out in two different sliping systems: flat–on–flat (ring contact, unidirectional sliding) and ball–on–flat (reciprocating sliding). Water and medical saline solutions were used as lubricants. A comparative analysis of the results revealed differences in the initiation and progress of wear and the...
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Validation of atmospheric aerosols sampling in equivalent fractions
PublicationPhysical properties and chemical composition of atmospheric aerosols are of extreme importance, in many fields of interest, namely the Environment even with legal implications. Atmospheric sampling poses inherent problems with consequent demands on sampling optimisation, with sampling strategies requiring validation. In this work a study was conducted aiming at validating the collection of atmospheric aerosols in equivalent fractions....
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Impacts of Using Exhaust Gas Recirculation and Various Amount of Dimethyl Ether Premixed Ratios on Combustion and Emissions on a Dual-Fuel Compression Ignition Engine
PublicationIn the presented research, the authors dealt with the specific properties of the combustion process of dimethyl ether (DME) in a combustion car (Volkswagen Golf IV) engine AJM 1.9 TDI PDE made by Volkswagen factory. Dimethyl ether is an alternative fuel produced most often from natural gas, which can be used in compression ignition engines as a single fuel or co-burned with diesel oil. This work describes the impacts of using exhaust...
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Nondestructive Optical Sensing of Flavonols and Chlorophyll in White Head Cabbage ( Brassica oleracea L. var. capitata subvar. alba ) Grown under Different Nitrogen Regimens
PublicationA multiparametric optical sensor was used to nondestructively estimate phytochemical compounds in white cabbage leaves directly in the field. An experimental site of 1980 white cabbages (Brassica oleracea L. var. capitata subvar. alba), under different nitrogen (N) treatments, was mapped by measuring leaf transmittance and chlorophyll fluorescence screening in one leaf/cabbage head. The provided indices of flavonols (FLAV) and...
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Experimental and Numerical Investigations of the Effect of Curing Conditions on the Temperature Rise of Concrete
PublicationThis paper presents experimental and numerical studies investigating the impact of three curing conditions on temperature evolution in concrete cubes. The tests were performed on samples of the same volume (3.375 dm3) under different curing conditions: room temperature, insulation boxes, and adiabatic calorimeter. Various cements (Portland cement, Portland composite cement, and blast furnace slag cement) and aggregates (gravel...
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Measurement of Coherence Bandwidth in UHF Radio Channels for Narrowband Networks
PublicationThis paper presents results of investigation on the coherence bandwidth of narrowband radio channels in 430MHz band. The coherence bandwidth values were estimated froma power delay profile obtained by recording CDMA2000 forward channel signals during real-fieldmeasurements in various environments:mediumcity, flat terrain, and hilly terrain in northern Poland.The results of measurements are compared with characteristic parameters...
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Experimental research on a hydrodynamic thrust bearing with hydrostatic lift pockets: Influence of lubrication modes on bearing performance
PublicationThe aim of the study is to investigate the performance of a thrust bearing equipped with hydrostatic lift pockets under different lubrication modes. Three types of flat land bearing lubrication modes are studied experimentally: hydrostatic lubrication (HS; forced oil injection to the pockets), hybrid lubrication (HS + HD; hydrostatic lubrication combined with the external forced bearing oil supply) and hydrodynamic lubrication...
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On Reduced-Cost Design-Oriented Constrained Surrogate Modeling of Antenna Structures
PublicationDesign of contemporary antenna structures heavily relies on full-wave electromagnetic (EM) simulation models. Such models are essential to ensure reliability of evaluating antenna characteristics, yet, they are computationally expensive and therefore unsuitable for handling tasks that require multiple analyses, e.g., parametric optimization. The cost issue can be alleviated by using fast surrogate models. Conventional data-driven...
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Valorization of waste cabbage leaves by postharvest photochemical treatments monitored with a non-destructive fluorescence-based sensor
PublicationThe biosynthesis of polyphenolic compounds in cabbage waste, outer green leaves of white head cabbage (Brassica oleracea L. var. capitata subvar. alba), was stimulated by postharvest irradiation with UVB lamps or sunlight. Both treatments boosted the content of kaempferol and quercetin glycosides, especially in the basal leaf zone, as determined by the HPLC analysis of leaf extracts and by a non-destructive optical sensor. The...
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Turbulence models impact on the flow and thermal analyses of jet impingement
PublicationAccurate numerical reconstruction of heat and mass transfer processes in particular applications, such a jet impingement, is difficult to obtain even with the use of modern computational methods. In the proposed paper, the flow and thermal phenomena occurring during single minijet impingement on the flat, concave and convex, heated surfaces were considered. Problem of impingement on non-flat surface, still not common and purely...
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Hydrogen and chalcogen bonds in crystals of chalcogenadiazolecarboxylic acids – competition or cooperation?
PublicationThis article presents crystal structures of chalcogenadiazolecarboxylic acids bearing both a hydrogen and a chalcogen bond donor. The selected molecules varied in the size of the aromatic unit, the chalcogen atom and/or the position of the carboxyl group in the core structure. The most common synthons in their lattice are "R" _"2" ^"2" (8) self-complementary acid dimers or four-membered [Ch···N]2 rings. Supramolecular synthons...
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Pressure drop related to flow maldistribution in a model minichannel plate heat exchanger
PublicationThe paper describes the issues related to the pressure drop that accompanies the phenomenon of maldistribution of working fluid between the channels of a model minichannel plate heat exchanger. The research concerns a single exchanger's plate containing 51 (in every geometry) parallel rectangular minichannels of hydraulic diameters 461 µm, 571 µm, 750 µm and 823 µm. In addition, the more complex geometry has been investigated,...
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If Gravity is Geometry, is Dark Energy just Arithmetic?
PublicationArithmetic operations (addition, subtraction, multiplication, division), as well as the calculus they imply, are non-unique. The examples of four-dimensional spaces, R^4 and (−L/2,L/2)^4, are considered where different types of arithmetic and calculus coexist simultaneously. In all the examples there exists a non-Diophantine arithmetic that makes the space globally Minkowskian, and thus the laws of physics are formulated in terms...
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The effect of tyre rubber grinding method on the rubber-asphalt binder properties
PublicationRubber products, especially those used in the automotive industry, are responsible for a significant amount of waste, mainly in the form of worn tyres. One way to recycle tyres is to use them as an asphalt binder modifier. The properties of rubber-asphalt binders vary greatly depending on the morphology of the ground tyre rubber (GTR) grains and the type of tyre to be recycled (car/truck). The paper presents the results of research...
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Carbon dioxide sequestration by industrial wastes through mineral carbonation: Current status and perspectives
PublicationMineral carbonation using natural minerals or industrial wastes is a safe and promising strategy for CO2 sequestration. Application of industrial wastes for this purpose has significant ecological and environmental value, which is one of the key green technologies in the global carbon mitigation. This review summarizes the current research status of CO2 mineralization by industrial wastes. This work surveys the mechanisms and capacities...
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The Influence of the Chemical Composition of Selected Waste Materials from the Production of Copper on the Final Environmental Assessment
PublicationThis article presents qualitative and quantitative analysis of the waste produced by KGHM Polska Miedź. The waste has been analyzed according to its chemical composition and balanced in order to be reused and recycled. Special attention has been paid to mining industries producing the biggest amount of waste and ore enrichment businesses generating waste, which isn’t reused nowadays. Laboratory reseach has been conducted on floatation...
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Performance of DS-CDMA Radionavigation Receiver with Subsample Time Measurement Resolution in Various Environments
PublicationThis paper presents results of investigation of position estimation performance in TDOA radionavigation system with receiver containing code tracking loop with subsample time measurement resolution. Position estimation accuracy was evaluated using real signals from CDMA base stations, recorded during measurement campaigns in various environments: on sea, flat terrain and hilly terrain.
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Matriptase-2: monitoring and inhibiting its proteolytic activity
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Miniaturized Passive Emission Chambers for In Situ Measurement of Emissions of Volatile Organic Compounds
PublicationThe results of many different studies have demonstrated unequivocally that the quality of indoor air is often much worse than that of atmospheric air. The presence of dangerous chemical compounds in indoor air can have an adverse impact on human health and cause numerous diseases of the respiratory and circulatory systems. Such harmful chemicals get into indoor air as a result of their emission from building and indoor materials....
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Progress in module design for membrane distillation
PublicationThere have been tremendous advances in membrane distillation (MD) since the concept was introduced in 1961: new membrane designs and process configurations have emerged, and its commercial viability has been evaluated in several pilot-scale studies. However, its high energy consumption has hindered its commercialization. One of the most promising ways to overcome this obstacle is to develop more energy-efficient membrane modules....
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Mining Knowledge of Respiratory Rate Quantification and Abnormal Pattern Prediction
PublicationThe described application of granular computing is motivated because cardiovascular disease (CVD) remains a major killer globally. There is increasing evidence that abnormal respiratory patterns might contribute to the development and progression of CVD. Consequently, a method that would support a physician in respiratory pattern evaluation should be developed. Group decision-making, tri-way reasoning, and rough set–based analysis...
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Multi-mode vibronic interactions in the five lowest electronic states of the fluorobenzene radical cation
PublicationThe multi-mode vibronic interactions between the five lowest electronic states of the fluorobenzene radical cation are investigated theoretically, based on ab initio electronic structure data, and employing the linear vibronic coupling model. Low-energy conical intersections, and strong vibronic couplings are found to prevail within the set of X-A and B-C-D cationic states, while the interactions between these two sets of states...
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Protokoły drzewa opinającego - ataki i metody obrony
PublicationW pracy przedstawiono sposoby ataków na sieci wykorzystujące realizacje drzewa opinającego STP (IEEE 802.1d i IEEE 802.1w a także modyfikacji STP wprowadzonych przez Cisco) oraz znane metody obrony przed atakami na STP. Zaproponowano także nową koncepcje obrony przed atakami mechanizmu STP wykorzystującą pole flags ramek BPDU.
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Wear of Ultra-thin DLC or Tungsten-modified DLC Coatings under Reciprocating Sliding
PublicationIn the paper results are presented from tests in reciprocating sliding of self mated specimens of DLC and tungsten modified DLC coatings on stainless steel substrate. The contact geometry chosen for the research task was ball on flat. The contacts were lubricated either with distilled water or medical saline solution. Results are presented with regard to wear resistance as a function of material type and lubricant used.
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Reasons for Implementing Movement in Kinetic Architecture
PublicationThe paper gives insights into different forms of movement in contemporary architecture and examines them based on the reasons for their implementation. The main objective of the paper is to determine: the degree to which the complexity of kinematic architecture results from functional and spatial needs and what other motivations there are. The method adopted to investigate these questions involves theoretical studies and comparative analyses...
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Sensorless Control of Induction Motor Based on Super-Twisting Sliding Mode Observer With Speed Convergence Improvement
PublicationThe super twisting sliding-mode observer (ST-SMO) has been proposed to achieve an effective method for alleviating low-order harmonics of measured quantities, issues related to DC drift, and suppression of chattering due to low-frequency sampling. The conventional ST-SMO, on the other hand, suffers from control delay in the convergence trajectory due to the system disturbance, resulting in decreased anti-disturbance capability...
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REMONTY I PRZEBUDOWY DACHÓW Z ZASTOSOWANIEM ELEMENTÓW LEKKIEJ OBUDOWY
PublicationW artykule przedstawiono przykładowe rozwiązania remontów i przebudowy dachów. Omówiono rozwiązania zmiany materiału pokrycia zarówno bez dodawania warstwy izolacyjnej, jak i z ułożeniem dodatkowej warstwy ocieplenia na istniejącej połaci dachowej a także sposób przebudowy dachu, polegający na ustawianiu nowej, lekkiej konstrukcji nośnej dachu, bezpośrednio na istniejącym pokryciu dachu płaskiego.
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Mechanical Properties of Polyester Coated Fabric Subjected to Biaxial Loading
PublicationThe paper is focused on the comparison between uniaxial and biaxial laboratory test results for polyester coated fabric. A short literature review concerning coated woven fabrics with emphasis on biaxial tensile tests is presented. A description of the polyester-coated fabric under biaxial test by means of constitutive models and material parameter values is proposed. To establish the right values of the ultimate tensile strength,...