Search results for: ENVIRONMENTAL STRESS
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Post-critical buckling of truncated conical carbon nanotubes considering surface effects embedding in a nonlinear Winkler substrate using the Rayleigh-Ritz method
PublicationThis research predicts theoretically post-critical axial buckling behavior of truncated conical carbon nanotubes (CCNTs) with several boundary conditions by assuming a nonlinear Winkler matrix. The post-buckling of CCNTs has been studied based on the Euler-Bernoulli beam model, Hamilton’s principle, Lagrangian strains, and nonlocal strain gradient theory. Both stiffness-hardening and stiffness-softening properties of the nanostructure...
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Pure cross-anisotropy for geotechnical elastic potentials
PublicationThe pure cross-anisotropy is understood as a special scaling of strain (or stress). The scaled tensor is used as an argument in the elastic stiffness (or compliance). Such anisotropy can be overlaid on the top of any elastic stiffness, in particular on one obtained from an elastic potential with its own stress-induced anisotropy. This superposition does not violate the Second Law. The method can be also applied to other functions...
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Stress-driven nonlocal elasticity for nonlinear vibration characteristics of carbon/boron-nitride hetero-nanotube subject to magneto-thermal environment
PublicationStress-driven nonlocal theory of elasticity, in its differential form, is applied to investigate the nonlinear vibrational characteristics of a hetero-nanotube in magneto-thermal environment with the help of finite element method. In order to more precisely deal with the dynamic behavior of size-dependent nanotubes, a two-node beam element with six degrees-of freedom including the nodal values of the deflection, slope and curvature...
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Strength parameters of polyester reinforced PVC coated fabric after short term creep loading in biaxial mode
PublicationThis study addresses the analysis of tensile strength parameters of the technical fabric VALMEX, which is composed of two orthogonal polyester thread families (named the warp and fill) and both sides PVC coated. The material was firstly subjected to 48-hour biaxial creep loading with the equal stress level in both orthogonal directions of the fabric. The stress levels were established as follows: 4.6 kN/m, 10.4 kN/m, 16.4 kN/m,...
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Corrosion and Cavitation Resistances of Low Alloy Steel After Frictional-Mechanical Treatment
PublicationPaper presents the results of the studies of wear, corrosion and cavitation resistances of the S355J2 low alloy medium carbon steel subjected to surface modification by friction-mechanical treatment, as tested in sea water simulated solution. To evaluate the effect of the surface treatment, the comparative studies of the corrosive properties of the steel before and after treatment have been considered. The treatment due to a severe...
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Electro-mechanical shear buckling of piezoelectric nanoplate using modified couple stress theory based on simplified first order shear deformation theory
PublicationThis paper studies the electro-mechanical shear buckling analysis of piezoelectric nanoplate using modified couple stress theory with various boundary conditions.In order to be taken electric effects into account, an external electric voltage is applied on the piezoelectric nanoplate. The simplified first order shear deformation theory (S-FSDT) has been employed and the governing differential equations have been obtained using...
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Analytical predictions for the buckling of a nanoplate subjected to non-uniform compression based on the four-variable plate theory
PublicationIn the present study, the buckling analysis of the rectangular nanoplate under biaxial non-uniform compression using the modified couple stress continuum theory with various boundary conditions has been considered. The simplified first order shear deformation theory (S-FSDT) has been employed and the governing differential equations have been obtained using the Hamilton’s principle. An analytical approach has been applied to obtain...
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Comparison of properties of the new electro-mechanical model and circumferential model of the inductive-dynamic drive
PublicationThe article presents a new electromechanical model of inductive-dynamic drive. The model is implemented in two environments: Maxwell for analyzing electrodynamic phenomena including moving of the disc and Ansys which allows for stress analysis on the basis of the volume forces imported from Maxwell. Additionally, a model validation by comparing with the existing circumferential model was carried out.
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CENTRAL-FORCE DECOMPOSITION OF THE TERSOFF POTENTIAL
PublicationCentral forces play important role in the analysis of results obtained with particle simulation methods, since they allow evaluating stress fields. In this work we derive expressions for a central-force decompositon of the Tersoff potential, which is often used to describe interatomic interactions in covalently bonded materials. We simplify the obtained expressions and discuss their properties.
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CPTU/DMT control of heavy tamping compaction of sands
PublicationHeavy tamping compaction method in cohesionless alluvial soil was evaluated with CPTU and DMT tests. Some examples of interpretation of soundings in pre-treated and compacted sands are given. The compaction work was performed in two stages. Compaction control was performed after each stage of tamping. Additional tests were performed two weeks after the compaction works completion to study the set-up effect. While typical increase...
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Recent Achievements in Constitutive Equations of Laminates and Functionally Graded Structures Formulated in the Resultant Nonlinear Shell Theory
PublicationThe development of constitutive equations formulated in the resultant nonlinear shell theory is presented. The specific features of the present shell theory are drilling rotation naturally included in the formulation and asymmetric measures of strains and stress resultants. The special attention in the chapter is given to recent achievements: progressive failure analysis of laminated shells and elastoplastic constitutive relation...
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Numerical modelling and analysis of steel specimens subjected to marine immersed corrosion and tensile load
PublicationThe present study develops numerical models to analyse the behaviour of steel specimens subjected to marine immersed corrosion degradation and tensile load. The finite element method with the use of the explicit dynamic solver LS-DYNA, satisfying the quasi-static conditions, is employed. Two numerical models are developed, where in the first one, the scans of surfaces gathered from corroded plate specimens are implemented directly...
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Design, synthesis, and biological evaluation of tetrahydroquinolinones and tetrahydroquinolines with anticancer activity
PublicationColorectal cancer (CRC) is the most commonly diagnosed cancer in Europe and the United States and the second leading cause of cancer related mortality. A therapeutic strategy used for the treatment of CRC involves targeting the intracellular levels of reactive oxygen species (ROS). In this study, we synthesized a series of novel tetrahydroquinolinones and assessed their ability to inhibit CRC growth and proliferation by evoking...
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Local buckling of composite channel columns
PublicationThe investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibre-reinforced laminate. Two approaches to member orthotropic...
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Numerical modelling of the mesofracture process of sintered 316L steel under tension using microtomography
PublicationThis paper concerns numerical modelling of the deformation process, taking into account the local fracture of porous 316L sinters at the mesoscopic scale using the finite element method. Calculations are performed with the use of geometrical models, to map the realistic shape of the porous mesostructure of the material, obtained by means of computed microtomography. The microtomographic device has limited and insufficient measurement...
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Influence of Surface Laser Treatment on Mechanical Properties and Residual Stresses of Titanium and its Alloys
PublicationSurface modification of the titanium and its alloys used in implantology with a long-pulse laser can change the surface topography, but it also leads to changes in the stress sign and magnitude in the resulting subsurface layer. The presented research was aimed at evaluating the state of stress after laser remelting with the Nd:YAG laser of pre-etched titanium alloys Ti6Al4V and Ti13Nb13Zr and pure titanium. The obtained surface...
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More Than just Antioxidants: Redox-Active Components and Mechanisms Shaping Redox Signalling Network
PublicationsettingsOrder Article Reprints This is an early access version, the complete PDF, HTML, and XML versions will be available soon. Open AccessReview More Than just Antioxidants: Redox-Active Components and Mechanisms Shaping Redox Signalling Network by Monika Kuczyńska,Patrycja Jakubek andAgnieszka Bartoszek *ORCID Faculty of Chemistry, Gdańsk University of Technology, 80-233 Gdańsk, Poland * Author to whom correspondence should...
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The effect of pH change of ketoprofen solutions on the germination of Sorghum bicolor (sorghum) seeds
Open Research DataIn these studies, an attempt was also made to determine whether (and, if so, to what extent) the change in pH affects the toxicity of ketoprofen will affect the germination of Sorghum bicolor (sorghum) seeds. As reported by Kudlak B, Wieczerzak M, Yotova G, Tsakovski S, Simeonov V, Namieśnik J (2016) Environmental risk assessment of Polish wastewater...
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Assessment of tensile forces in Sopot Forest Opera membrane by in situ measurements and iterative numerical strategy for inverse problem
PublicationAssessment of tensile forces in newly build Sopot Forest Opera roofing membrane is presented. The procedure is based on in situ measurements and solution of the inverse problem by an iterative procedure. The goal of the analysis is to determine whether the stress state of the membrane is consistent with the design assumptions. The paper contains the description of measurements, used instruments, applied loadings, numerical investiga-tions...
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Hydrogen induced degradation of structural steel exposed to the technical liquid hydrocarbons
PublicationSusceptibility of the differently heat treated 26H2MF steel to stress corrosion cracking has been evaluated in the constant strain rate tension tests done at the strain rate 10-6s-1 and in the constant load tests done at the 0,98 of fracture load. The boiler fuel and the aged mineral oil at 135C and 80C respectively, have been used as the aggressive environments.
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Value of tax preferences by areas of support and types of taxes in 2013
Open Research DataThese data contain information prepared by the Ministry of Finance on the value of tax preferences by areas of support and types of taxes in 2013.
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Value of tax preferences by areas of support and types of taxes in 2014
Open Research DataThese data contain information prepared by the Ministry of Finance on the value of tax preferences by areas of support and types of taxes in 2014.
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Value of tax preferences by areas of support and types of taxes in 2011
Open Research DataThese data contain information prepared by the Ministry of Finance on the value of tax preferences by areas of support and types of taxes in 2009.
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Value of tax preferences by areas of support and types of taxes in 2009
Open Research DataThese data contain information prepared by the Ministry of Finance on the value of tax preferences by areas of support and types of taxes in 2009.
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Value of tax preferences by areas of support and types of taxes in 2010
Open Research DataThese data contain information prepared by the Ministry of Finance on the value of tax preferences by areas of support and types of taxes in 2010.
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Value of tax preferences by areas of support and types of taxes in 2012
Open Research DataThese data contain information prepared by the Ministry of Finance on the value of tax preferences by areas of support and types of taxes in 2012.
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Study of the process of biofilm formation by UPEC IH11128 in the LB medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the LB medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Impact of binary mixtures of Irgasan (triclosan) and two parabens on endocrine processes of the model organism Saccharomyces Cerevisiae (using XenoScreen YES/YAS test)
Open Research DataData shown in data set illustrate the results of the edorin processes of the Irgasan (triclosan) mixture with two parabens e.i. methylparaben and buthylparaben. S cerevisiae is used as a model organism in the monitoring of endocrine disruptors in environmental and reference samples in Xenometrix® systems - XenoScreen®. Tested substances have bakeriosis...
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Impact of binary mixtures of Irgasan (triclosan) and Diclofenac on endocrine processes of the model organism Saccharomyces Cerevisiae (using XenoScreen YES/YAS test)
Open Research DataThe XenoScreen YES/YAS reagents and methodology is given in Kudłak et al. (2019) and in details in electronic supplementary material.
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On the crack front curvature in bonded joints
PublicationStandard tests of adhesively bonded specimens are likely to produce heterogeneous stress distribution along the crack front and its vicinity. High separation rate mode I dominated fracture test is performed.Observation of post mortem fractured surfaces with an optical microscope reveals characteristic features of mixed mode I/III fracture near the sides of the specimen but not in the middle. At first, finite elements calculations...
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Comparitive study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels
PublicationIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation...
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Influence of meniscus shape in the cross sectional plane on the knee contact mechanics
PublicationWe present a three dimensional finite element analysis of stress distribution and menisci deformation in the human knee joint. The study is based on the Open Knee model with the geometry of the lateral meniscus which shows some degenerative disorders. The nonlinear analysis of the knee joint under compressive axial load is performed. We present results for intact knee, knee with partial and complete radial posterior meniscus root...
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On local buckling of cold-formed channel members
PublicationThe paper deals with local buckling of the compressed flanges of cold-formed thin-walled channel beams subjected to pure bending or axially compressed columns. Arbitrarily shaped flanges of open cross-sections and the web-flange interactions are taken into account. Buckling deformation of a beam flange is described by displacement related to torsion of the flange about the line of its connection with the web. Total potential energy...
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The effect of external load on ultrasonic wave attenuation in steel bars under bending stresses
PublicationThe stress state in deformed solids has a significant impact on the attenuation of an ultrasonic wave propagating through the medium. Measuring a signal with certain attenuation characteristics can therefore provide useful diagnostic information about the stress state in the structure. In this work, basic principles behind a novel attenuation-based diagnostic framework are introduced. An experimental study on steel bars under three-point...
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EVALUATING THE INFLUENCE OF BENDING STRESS ON A 1H18N9 STEEL SHAFT WEAR PROCESS IN A WATER LUBRICATED SLIDING BEARING WITH A RUBBER BUSHING
PublicationThe issue of excessive wear of shaft journals co-working with a rubber bearing has been unexplained so far. Premature and sometimes very intensive wear of ship sliding bearings in water conditions is the reason for carry out very expensive and more frequent than expected repairs. The authors (E. Piątkowska, W. Litwin) made an attempt to find a case that influences the value of this wear described in the paper “Attempt at Evaluating...
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Effect of surface on the flexomagnetic response of ferroic composite nanostructures; nonlinear bending analysis
PublicationOur analysis incorporates the geometrically nonlinear bending of the Euler-Bernoulli ferromagnetic nanobeam accounting for a size-dependent model through assuming surface effects. In the framework of the flexomagnetic phenomenon, the large deflections are investigated referring to von-Kármán nonlinearity. Employing the nonlocal effects of stress coupled to the gradient of strain generates a scale-dependent Hookean stress-strain...
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Applying molecular dynamics simulation to take the fracture fingerprint of polycrystalline SiC nanosheets
PublicationGraphene-like nanosheets are the key elements of advanced materials and systems. The mechanical behavior of the structurally perfect 2D nanostructures is well documented, but that of polycrystalline ones is less understood. Herein, we applied molecular dynamics simulation (MDS) to take the fracture fingerprint of polycrystalline SiC nanosheets (PSiCNS), where monocrystalline SiC nanosheets (MSiCNS) was the reference nanosheet....
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Stability analysis of nanobeams in hygrothermal environment based on a nonlocal strain gradient Timoshenko beam model under nonlinear thermal field
PublicationThis article is dedicated to analyzing the buckling behavior of nanobeam subjected to hygrothermal environments based on the principle of the Timoshenko beam theory. The hygroscopic environment has been considered as a linear stress field model, while the thermal environment is assumed to be a nonlinear stress field based on the Murnaghan model. The size-dependent effect of the nanobeam is captured by the nonlocal strain gradient...
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Importance of sign conventions on analytical solutions to the wave-induced cyclic response of a poro-elastic seabed
PublicationThis paper discusses the influence of different sign conventions for strains and stresses, i.e. the solid mechanics sign convention and the soil mechanics sign convention, on the form of governing partial differential equations (the static equilibrium equations and the continuity equation) used to describe the wave-induced cyclic response of a poro-elastic seabed due to propagation of a sinusoidal surface water-wave. Some selected...
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Calculation of Induced Sheath Voltages in Power Cables – Single Circuit System versus Double Circuit System
PublicationThis paper presents comparison of values of induced sheath voltages in power cable metallic sheaths when one or two cables per phase are used. Calculation of voltages is performed for various phase sequences of the power cables. Three types of the sheaths bonding and earthing are considered. Shock hazard and voltage stress of non-metallic outer sheath of cables are evaluated. The proposed, optimal configuration of the power cable...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,5% casamino acids medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids+0,2% glycerol medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,5% casamino acids+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Results of modeling of pharmaceuticals mixtures toxicity with deviation ratio and best-fit functions models using Saccharomyces cerevisiae yeast as model organism
Open Research DataThe research was concerned with verifying the impact of binary mixtures of nine pharmaceuticals against a selected organism, i.e., the yeast Saccharomyces cerevisiae. S cerevisiae is used as a model organism in the monitoring of endocrine disruptors in environmental and reference samples in Xenometrix® systems - XenoScreen®. Tested pharmaceuticals,...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids+0,2% glucose medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,5% casamino acids+0,2% glycerol medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids medium
Open Research DataBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...