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Search results for: BOND STIFFNESS
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Waterborne polyesters partially based on renewable resources
PublicationA new experimental approach for preparing biobased, water-soluble polyesters via titanium(IV) n-butoxide-catalyzed bulk polycondensation is presented. In the described method polymers were obtained from isosorbide, maleic anhydride and poly(ethylene glycol). The chemical structure of the synthesized polyesters was confirmed using 2D NMR spectroscopy and by titration methods. Careful analysis of 2D NMR spectra viz. Correlation Spectra...
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Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment
PublicationHyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and...
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Cooperativity of Halogen- and Chalcogen-Bonding Interactions in the Self-Assembly of 4‑Iodoethynyl- and 4,7-Bis(iodoethynyl)benzo-2,1,3-chalcogenadiazoles: Crystal Structures, Hirshfeld Surface Analyses, and Crystal Lattice Energy Calculations
PublicationSeveral new 4-iodoethynyl- and 4,7-bis- (iodoethynyl)benzo-2,1,3-chalcogenadiazoles were prepared, and a comprehensive analysis of the most prominent secondary bonding interactions responsible for the crystal self-assembly was performed using X-ray diffraction. The presence of both the iodoethynyl and chalcogenadiazole moieties allows an evaluation of the preference of these molecules to aggregate through either chalcogen- or halogen-bonding...
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Finite element models used in diagnostics of transverse cracks in bridge approach pavement
Open Research DataTransverse cracks in the asphalt pavement were observed on bridge structures next to single-module expansion joints with a 5 meter approach slab set at the depth of 1 m. The finite element (FE) models of the approach pavement were created to investigate the reasons of premature cracking and crack initiation mechanism over the back edge of the abutment...
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STABILITY AND LOAD BEARING CAPACITY OF A BARS WITH BUILT UP CROSS SECTION AND ELASTIC SUPPORTS
PublicationThe present paper is devoted to the numerical analysis and experimental tests of compressed bars with built–up cross section which are commonly used as a top chord of the roof trusses. The significant impact on carrying capacity for that kind of elements in case of out-of-plane buckling is appropriate choice of battens which are used to provide interaction between separate members. Linear buckling analysis results and nonlinear static...
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Experimental and analytical analysis of punching shear in flat slabs supported on column topped with concrete head
PublicationAn experimental laboraatory test of the two series of slab-column elements topped with drop panels of varying sizes is described in this paper. The scope of the paper is to investigate the influence of the drop panel size and stiffness on the behaviour of the connection between the flat slab and the column topped by the concrete head. The impact of the head size and stiffness is analysed analytically and experimentally. The experimental...
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Gold(III) complexes with chloride and cyanopyridines: Facilitated hydrolysis of nitrile ligand to amide and antibacterial activity
PublicationA range of novel simple gold(III) compounds has been synthesized in their monocrystalline form, including two previously unknown chloro-complexes of Au3+ with 2-cyanopyridine or 3-cyanopyridine, respectively. Our investigations have revealed the intricate nature of the reaction between 2-cyanopyridine and tetrachloroauric acid, yielding at least three distinct products. The main product, obtained in high yield, is a salt featuring...
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Chalcogen bonding interactions in a series of aromatic selenocyanates
PublicationSelenium atoms in aromatic selenocyanates are characterized by the occurrence of two σ-holes, a stronger one in the prolongation of the NC–Se bond and a weaker one in the prolongation of the Ar–Se bond. The crystal structures of several bis(selenocyanato) derivatives, prepared by a method originally developed for ortho bis-substituted derivatives, illustrate very well this difference, with a short NC–Se⋯NC ChB interaction organizing...
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Comparison of non-linear statical analysis of truss with linear and rotational side supports and 3d roof model
PublicationIn the paper geometrically non-linear analysis of example truss with linear and rotational elastic side supports is compared with geometrically non-linear analysis of part of the roof construction with purlins and truss-bracing. For different stiffness of side-supports a non linear relation between normal force in compressed chord due to out of truss plane displacement has been calculated.
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Random field model of foundations at the example of continuous footing
PublicationThe purpose of the paper is to indicate an efficient method of foundation settlement analysis taking into account the variability of soil properties. The impact of the random variable distribution (Gauss or Lognormal) describing soil stiffness on foundation deposits was assessed. The Monte Carlo simulation method was applied in the computations. The settlements of the strip foundation with the subsoil described by a single random...
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Hopping or Tunneling? Tailoring the Electron Transport Mechanisms through Hydrogen Bonding Geometry in the Boron-Doped Diamond Molecular Junctions
PublicationMechanisms of charge transport in molecular junctions involving hydrogen bonds are complex and remain mostly unclear. This study is focused on the elucidation of the electron transfer in a molecular device consisting of two boron-doped diamond interfaces bound with an aromatic linker and a hydrogen bonding surrogating molecule. The projected local density of states (PLODS) analysis coupled with transmission spectra and current−voltage...
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Chemistry and Nanochemistry 2024
e-Learning CoursesWe start from General Chemistry, including: calculus in chemistry, bonds, balancing the chemical reactions, redox reactions, electrochemistry, pH, acids, bases, salts, oxides, organic molecules, and many informations about synthesis, analysis and applications in nanochemistry.
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Chemistry and Nanochemistry 2023
e-Learning CoursesWe start from General Chemistry, including: calculus in chemistry, bonds, balancing the chemical reactions, redox reactions, electrochemistry, pH, acids, bases, salts, oxides, organic molecules, and many informations about synthesis, analysis and applications in nanochemistry.
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Crystal structures of the DsbG disulfide isomerase reveal an unstable disulfide
PublicationDsb proteins control the formation and rearrangement of disulfide bonds during the folding of secreted and membrane proteins in bacteria. DsbG, a member of this family, has disulfide bond isomerase and chaperone activity. Here, we present two crystal structures of DsbG at 1.7- and 2.0-Angstrom resolution that are meant to represent the reduced and oxidized forms, respectively. The oxidized structure, however, reveals a mixture...
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Comprehensive evaluation of physical properties and carbon dioxide capacities of new 2-(butylamino)ethanol-based deep eutectic solvents
PublicationThe aim of this research was to assess the impact of the components of alkanolamine deep eutectic solvents (DESs) on the physical properties of those DESs and their carbon dioxide capacity. To achieve this goal, novel deep eutectic solvents were synthesized by using 2-(butylamino)ethanol (BAE) as the hydrogen bond donor (HBD), along with tetrabutylammonium bromide TBAB), tetrabutylammonium chloride (TBAC), or tetraethy- lammonium...
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Experimental and numerical study on stability loss of innovative geometry steel girder
PublicationThis paper presents the experimental and numerical analysis of an innovative plate girder geometry with variable web thicknesses. An idea proposed in this research is to increase the stability of the girder web by increasing its thickness in the compressed zone. This solution can replace commonly used longitudinal stiffeners which are designed to prevent web local loss of stability. Moreover, such an innovative approach requires...
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An approach for the response of buildings subjected to impact load after soft-story failure due to earthquake excitation
Publicationhe soft-story failure is one of the most typical types of damage observed in buildings during earthquakes. The failure of an intermediate soft story of a structure results in large impact loading acting on the lower floors due to the fall of the upper stories. The aim of the present paper is to study the behavior of the structural members exposed to such extreme load conditions occurring under ground motion excitation. Special...
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Application of probabilistic tools to extend load test design of bridges prior to opening
PublicationLoad tests of bridges are widely performed in a large number of countries. Deterministic comparison of measurement results to the theoretical, FEM (finite element method)-based outcomes with possible further calibration is mostly applied. Sometimes, the data collected in the tests are also used to calibrate the reliability factors of bridge structures or their components. This work proposes to complement the stage of the load test...
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Monosubstituted hydrazone β-cyclodextrin derivatives for pH-sensitive complex formation with aromatic drugs
PublicationA new and convenient synthetic pathway was developed to produce monosubstituted cyclodextrins with high yields. Each of the β-cyclodextrin derivatives described in this work has an aromatic substituent connected with cyclodextrin core by a pH-sensitive hydrazone linker and a carbon chain. Carbon chains differ in lengths having one or three carbon atoms. The correlation between water solubility and linker length was determined using...
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Variable Order Differential Models of Bone Remodelling * *This work was supported by FCT, through IDMEC, under LAETA, projects UID/EMS/50022/2013, BoneSys, joint Polish-Portuguese project Modelling and controlling cancer evolution using fractional calculus, PERSEIDS (PTDC/EMS-SIS/0642/2014) and IF/00653/2012
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Modeling of Composite Shells in 6-Parameter Nonlinear Theory with Drilling Degree of Freedom
PublicationWithin the framework of a 6-parameter nonlinear shell theory, with strain measures of Cosserat type, constitutive relations are proposed for thin elastic composite shells. The material law is expressed in terms of five engineering constants of classical anisotropic continuum plus an additional parameter accounting for drilling stiffness. The theory allows for unlimited displacements and rotations. A number of examples are presented...
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Analysis of the chemical composition of MnO-B2O3 glass
Open Research DataStructural and thermal properties of xMnO−(100−x)B2O3 (where x = 40, 50 and 60 mol%) glass samples have been investigated with the employment of various techniques. Fourier transform infrared spectroscopy results revealed the influence of MnO on glass matrix. Decrease of B–O bond-related band intensities has been observed. MnO addition was found to...
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Chosen aspects of skeletal system modeling: Numerical solid and shell models of femur part
PublicationThe purpose of this paper is to present a new method of femur part modeling by using the finite element method. This method treats a femur part as a system composed of cortical and trabecular bone. For the purpose of determining a proper shape of femur part model there were created three models: a) the first one describes a femur part as a solid structure; b) the second one describes a femur part as a connection of cortical bone...
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Modyfikacja cementu kostnego w celu uzyskania długotrwałej ochrony antybakteryjnej
PublicationNiniejsza rozprawa doktorska stanowi przewodnik po jednotematycznym cyklu publikacji, dotyczącym modyfikacji akrylowego cementu kostnego celem uzyskania długotrwałej i efektywnej ochrony antybakteryjnej. W ramach niego przeprowadzono badania eksperymentalne polegające na opracowaniu technologii wytwarzania modyfikowanego cementu kostnego oraz procedury medycznej jego stosowania. Cement kostny był modyfikowany przez zastosowanie...
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Computational analysis of substituent effects on proton affinity and gas-phase basicity of TEMPO derivatives and their hydrogen bonding interactions with water molecules
PublicationThe study investigates the molecular structure of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and its derivatives in the gas phase using B3LYP and M06-2X functional methods. Intermolecular interactions are analyzed using natural bond orbital (NBO) and atoms in molecules (AIM) techniques. NO2-substituted TEMPO displays high reactivity, less stability, and softer properties. The study reveals that the stability of TEMPO derivatives...
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Solubility of Carbon Dioxide in Deep Eutectic Solvents Based on 3-Amino-1-Propanol and Tetraalkylammonium Salts at Low Pressure
PublicationDeep eutectic solvents (DESs) became an object of a great interest as an alternative to ionic liquids (ILs) and commonly used in CO2 capture amine solutions. In the present study, five different DESs based on 3-amino-1-propanol as physical-chemical CO2 absorbents were used. The composition was chosen in order to estimate the effects of hydrogen bond acceptor:hydrogen bond donor (HBA:HBD) molar ratio, anion type and length of alkyl...
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Interpolator wykorzystujący filtr z maskowaniem charakterystyki częstotliwościowej
PublicationInterpolator o dużej krotności wymaga stosowania dolnoprzepustowych filtrów cyfrowych o bardzo wąskim paśmie przejściowym. Przekłada się to na dużą złożoność obliczeniową i problemy z projektowaniem filtrów interpolacyjnych. W pracy zaproponowano użycie metody FRM rozbijającej filtr o wąskim paśmie przejściowym na grupę filtrów o obniżonych wymaganiach, co zmniejsza liczbę niezerowych współczynników. W rezultacie użycie tego rozwiązania...
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5-Thiocyanato-2′-deoxyuridine as a possible radiosensitizer: electron-induced formation of uracil-C5-thiyl radical and its dimerization
PublicationIn this work, we have synthesized 5-thiocyanato-2′-deoxyuridine (SCNdU) along with the C6-deuterated nucleobase 5-thiocyanatouracil (6-D-SCNU) and studied their reactions with radiation-produced electrons. ESR spectra in γ-irradiated nitrogen-saturated frozen homogeneous solutions (7.5 M LiCl in H2O or D2O) of these compounds show that electron-induced S–CN bond cleavage occurs to form a thiyl radical (dU-5-S˙ or 6-D-U-5-S˙) and...
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In vitro antioxidative and binding properties of phenolics in traditional, citrus and exotic fruits
PublicationMany polyphenols bind proteins, therefore our research was focused on the potential of protein binding to polyphenols of investigated fruits and their health-related effects. The contents of polyphenols and related antioxidant activities of traditional, citrus and exotic fruits were compared. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples and their interaction with human serum albumin (HSA)...
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Induced-fit binding of laccase to gold and carbon electrodes for the biological fuel cell applications
PublicationAnalogues of laccase natural substrates (syringic, veratric, ferulic, vanillic, isovanillic, 3,5-dimethoxybenzoic aldehydes) were employed to bind and orient laccase molecules in a way which facilitates adsorption of the catalyst molecules and their electrical connection with the conductive support. Laccase was bound efficiently to these substrates both on gold and carbon electrodes forming, respectively, 2D and 3D films sensitive...
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Photochemical and thermal reaction of intermediates in the phenylnitrene rearangment inside a hemicarcerand
PublicationBroadband irradiation (λ > 320 nm) of hemicarceplex H1 between −74 °C and −84 °C, produces encapsulated didehydroazepine (2), triplet phenylnitrene (3PN), 2-azabicyclo[3.2.0]hepta-1,3,6-triene (6), and 4-azaspiro[2.4]hepta-1,4,6-triene (7). The highly strained anti-Bredt imine 6 is formed from 2 via a photochemical four-electron electrocyclization. Under the irradiation conditions, 6 rearranges further to azaspirene 7. In addition,...
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Oxygen concentration regulated the efficient liquefaction of vulcanized natural rubber
PublicationOxidative liquefaction represents a promising avenue for the homogeneous and high-value utilization of waste tire rubber. Given that truck tires predominantly comprise natural rubber (NR), this study investigated the efficient liquefaction of vulcanized NR regulated by oxygen concentration. Remarkably, the liquefaction of vulcanized NR was realized with an oxygen concentration of 75 % at 200 °C within 3 min. FTIR spectroscopy showed...
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Polaronic and Mott insulating phase of layered magnetic vanadium trihalide VCl3
PublicationTwo-dimensional (2D) van der Waals (vdW) magnetic 3d-transition metal trihalides are a new class of functional materials showing exotic physical properties useful for spintronic and memory storage applications. In this article, we report the synthesis and electromagnetic characterization of single-crystalline vanadium trichloride, VCl 3 , a novel 2D layered vdW Mott insulator, which has a rhombohedral structure (R3, No. 148) at...
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Catalytic Mechanism of Non-Target DNA Cleavage in CRISPR-Cas9 Revealed by Ab Initio Molecular Dynamics
PublicationCRISPR-Cas9 is a cutting-edge genome editing technology, which uses the endonuclease Cas9 to introduce mutations at desired sites of the genome. This revolutionary tool is promising to treat a myriad of human genetic diseases. Nevertheless, the molecular basis of DNA cleavage, which is a fundamental step for genome editing, has not been established. Here, quantum–classical molecular dynamics (MD) and free energy methods are used...
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Molecular basis and potential activity of HIV-1 reverse transcriptase toward trimethylamine-based compounds
PublicationReverse transcriptase (RT) inhibitors are currently used to treat human immunodeficiency virus (HIV)-1 infections. In this work, novel triethylamine derivatives were designed and studied by rigid and flexible docking and molecular dynamics (MD) approaches. An apo form of HIV-1 RT was also studied by MD simulation to analyze comparative response of protein in ligand-bound and ligand-unbound forms. Among newly designed HIV-1 RT inhibitors,...
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Debonding of coin-shaped osseointegrated implants: Coupling of experimental and numerical approaches
PublicationWhile cementless implants are now widely used clinically, implant debonding still occur and is difficult to anticipate. Assessing the biomechanical strength of the bone–implant interface can help improving the understanding of osseointegration phenomena and thus preventing surgical failures. A dedicated and standardized implant model was considered. The samples were tested using a mode III cleavage device to assess the mechanical...
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Postępy technik w elektronice
e-Learning CoursesPostępy technik w elektronice [moduł dyscyplinarny, do wyboru Grupa A] Prowadzący: Prof. Marcin Gnyba, Prof. Małgorzata Jędrzejeska-Szczerska, Prof. Piotr Jasiński, Prof. Janusz Smulko, Prof. Sebastian Molin, Prof. Łukasz Kulas Terminy: 15.04 (g. 14-16), 16.04 (g. 12-14), 14.05 (g. 13-15), 19.05 (g.17-19), 26.05 (g. 17-19) 27.05 (g.10-12 ) 28.05 (10-13) Tematyka realizowanego przedmiotu obejmuje: Czujniki elektroniczne...
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Modelling tunnelling-induced deformation in stiff soils with a hyperelastic–plastic anisotropic model
PublicationIn this paper, the tunnelling-induced deformation in anisotropic stiff soils is analysed using FE modelling. The influence of material description is investigated rather than an advanced simulation of the tunnelling method. A new hyperelastic– plastic model is proposed to describe the anisotropic mechanical behaviour of stiff highly overconsolidated soil. This model can reproduce the superposition of variable stress-induced anisotropy...
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A procedure for the identification of effective mechanical parameters of additively manufactured elements using integrated ultrasonic bulk and guided waves
PublicationThe subject of the current work was a simple but robust novel two-stage procedure for the non-destructive determination of effective elastic constants using ultrasonic wave propagation. First, ultrasonic bulk wave velocities measured on cubic samples were used to calculate most of the elements of the stiffness matrix. Secondly, the remaining elements were determined using the dispersion curves of elastic guided waves measured on...
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Research on operational characteristics of tyres with run flat insert
PublicationThe paper describes results of research on heavy vehicle tyre with Run Flat VFI insert. The experiment has included the determination of heat generation, rolling resistanceand radial stifnessof two different tyre designes (textile and steel carcass). The results have been used for the purpose of ewalution of tyre operating characteristics. The study included research on non-inflated tyre properties. The purpose of the paper is...
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Mechanical properties of Precontraint 1202 S2 based on uniaxial tensile and creep tests
PublicationThe purpose of the paper is the estimation of the polyvinyl chloride – polyester-coated fabric (Precontraint 1202 S2) mechanical properties under uniaxial tensile tests as well as short- and long-time creep tests. The uniaxial tests are the basis of non-linear elastic description while the creep tests are used for the evaluation of the stiffness parameters in time and for the identification of the standard viscoelastic model. The...
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The dependence of linear viscoelasticity limits of cold-recycled mixtures on time of curing and compaction method
PublicationCold-recycled mixtures are currently among the most widely used and investigated methods that enable recycling of old pavement structures in an environmentally friendly manner. Upon milling, the old pavement structure – whose gradation can be improved with addition of virgin aggregate – is mixed and compacted at ambient temperature. The main binding agents are bituminous emulsion and cement. Due to their dual binding behaviour,...
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Structural and dynamic properties of water within the solvation layer around various conformations of the glycine-based polypeptide
PublicationSeveral conformations of the solvated glycine-based polypeptides were investigated using molecular dynamics simulations. Some properties of water in the neighbouring space around these molecules were investigated. It was found, that water forms a well-defined layer - the first solvation shell - around the peptide molecule, and thickness of this layer is independent of the peptide structure, and it equals to approximately 0.28 nm....
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Retrievable strain measuring system in screw displacement piles - readings and results interpretation problems
PublicationStatic load tests on foundation piles are generally carried out in order to determine load – displacement characteristic of the pile. For more detailed information, e.g. force distribution along the shaft, load transfer mechanism and characteristics of soil-structure interaction (unit resistance curves t-z, q-z) additional pile instrumentation is required. Most popular techniques focus on direct concrete strain measurements and...
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CERVIX UTERI, Endocervix - Female, 66 - Tissue image [12210630006822921]
Open Research DataThis is the histopathological image of CERVIX UTERI tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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A Subspace-Splitting Moment-Matching Model-Order Reduction Technique for Fast Wideband FEM Simulations of Microwave Structures
PublicationThis article describes a novel model-order reduction (MOR) approach for efficient wide frequency band finite-element method (FEM) simulations of microwave components. It relies on the splitting of the system transfer function into two components: a singular one that accounts for the in-band system poles and a regular part that has no in-band poles. In order to perform this splitting during the reduction process, the projection...
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Stability of truss with side - supports. The case of linear and rotational elastic supports
PublicationThe research is devoted to study lateral buckling of truss with linear and rotational elastic side-supports. Geometrically nonlinear analysis of example truss with linear and rotational elastic sidesupports is carried out. The limit normal force in compressed chord of the truss due to stiffness of side supports is calculated. The elastic support reaction in relation to force in compressed chordand coefficient of buckling length...
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The effect of circular saw blade clamping diameter on its resonant frequencies
PublicationIn this paper results of comparison of characteristic resonant frequencies of circular saw blades as a function of saw clamping diameter from the impact test are presented. Obtained results revealed that proportionally with the increase of the saw clamping diameter also the dynamical stiffness of the saw blade increased. As a consequence of that the resonant frequencies of the saw blade move to higher values. Moreover, with the...
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The Effect of Circular Saw Blade Clamping Diameter on its Resonant Frequencies
PublicationIn this paper results of comparison of characteristic resonant frequencies of circular saw blades as a function of the saw clamping diameter from the impact test are presented. Obtained results revealed that proportionally with the increase of the saw clamping diameter also the dynamical stiffness of the saw blade increased. As a consequence of that the resonant frequencies of the saw blade move to higher values. Moreover, with...
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Sławomir Milewski prof. dr hab. inż.
PeopleSławomir Milewski, born in 1955 in Puck, Poland, graduated in 1979 in Chemistry from the Faculty of Chemistry, Gdańsk University of Technology (GUT). In 1984 was employed at the Department of Pharmaceutical Technology and Biochemistry. In 1985 he got his PhD, in 1994 became a DSc (habilitation) and in 2002 got the professorship in chemical sciences. Currently he is a full professor and Head of the Department of Pharmaceutical Technology...