Filters
total: 1137
displaying 1000 best results Help
Search results for: CATHETER-INDUCED DISSECTION
-
Similarities and Differences Between the Vertex Cover Number and the Weakly Connected Domination Number of a Graph
PublicationA vertex cover of a graph G = (V, E) is a set X ⊂ V such that each edge of G is incident to at least one vertex of X. The ve cardinality of a vertex cover of G. A dominating set D ⊆ V is a weakly connected dominating set of G if the subgraph G[D]w = (N[D], Ew) weakly induced by D, is connected, where Ew is the set of all edges having at least one vertex in D. The weakly connected domination number γw(G) of G is the minimum cardinality...
-
Dynamic analysis of temporary steel grandstand equipped with different types of bracing system
PublicationIn the paper, behaviour of a temporary steel grandstand equipped with two different types of bracing system has been analysed through the numerical study. A typical solution concerning application of a diagonal tubular members has been compared with elements proposed by authors and called polymer dampers. A polymer element consists of two L-shape steel members bonded with polymer mass. The aim of the paper is to verify the effectiveness...
-
Load testing of a suspended footbridge in Radom (Poland)
PublicationThe footbridge in Radom is a suspended bridge of an interesting architectural form. The structure was de-signed for 4 kN/m2 of crowd loading. Dynamic calculations were not included in the design. The structure’s acceptance tests took place on the 14th of October 2016. The behaviour of the footbridge in static testing met the expectations. Unfortunately, as a result of dynamic tests, dangerous behaviour of the footbridge was revealed....
-
Numerical analysis of a temporary steel grandstand
PublicationThe purpose of this paper is to present the results of the numerical analysis focused on the response of the temporary steel scaffolding grandstand subjected to human-induced vibrations due to jumping. Shell as well as beam elements have been used in the numerical model. Its first stage has involved conducting modal analysis in order to determine the modes of free vibrations and the corresponding natural frequencies for the empty...
-
Algorithms for testing security in graphs
PublicationIn this paper we propose new algorithmic methods giving with the high probability the correct answer to the decision problem of security in graphs. For a given graph G and a subset S of a vertex set of G we have to decide whether S is secure, i.e. every subset X of S fulfils the condition: |N[X] \cap S| >= |N[X] \ S|, where N[X] is a closed neighbourhood of X in graph G. We constructed a polynomial time property pseudotester based...
-
Adaptation of the arbitrary Lagrange–Euler approach to fluid–solid interaction on an example of high velocity flow over thin platelet
PublicationThe aim of this study is to analyse the behaviour of a thin plate with air flow velocities of 0.3–0.9 Ma. Data from the experiment and numerical tools were used for the analysis. For fluid–solid interaction calculations, the arbitrary Lagrange–Euler approach was used. The results of the measurements are twofold. The first one is the measurement of the flow before and after vibrating plate, i.e. pure flow plate, and the second consists...
-
Fawad Ahmed PhD Scholar
PeopleI am Ph.D. Scholar in Faculty of Mechanical Engineering at Gdansk University of Technology, Poland. My research focuses on improving the thermal management of batteries that are used in Electric Vehicles. I received my MS in Thermal Energy Engineering from the National University of Sciences and Technology, Pakistan. My MS thesis was related to the application of thermal energy storage systems for space heating. I tried to improve...
-
DNA restriction analysis as a supportive tool in mechanistic studies carried out by 32P-postlabelling
PublicationNumerous antitumor and carcinogenic compounds are able to modify DNA by forming covalent bonds with its constituents, while some anticarcinogenic compounds are known to prevent such a modification. All these processes are of vital biological import_ance, though deeper inside into factors influencing formation of DNA adducts is difficult due to the low level of their occurrence. 32P-Postlabelling approach ensures very sensitive...
-
Prime-Boost Vaccination with Toxoplasma Lysate Antigen, but Not with a Mixture of Recombinant Protein Antigens, Leads to Reduction of Brain Cyst Formation in BALB/c Mice
PublicationIntroduction Infection with the ubiquitous parasite Toxoplasma gondii is a threat for immunocompro- mised patients and pregnant women and effective immune-prophylaxis is still lacking. Methods Here we tested a mixture of recombinant T . gondii antigens expressed in different develop- mental stages, i.e., SAG1, MAG1 and GRA7 (SMG), and a lysate derived from T . gondii tachyzoites (TLA) for prophylactic vaccination against cyst formation....
-
Induction of G2/M phase arrest and apoptosis of human pancreatic cancer BxPC-3 cells by potenet antitumor 1-nitroacridine derivative C-1748
PublicationPancreatic ductal adenocarcinoma (PDA) is among the most lethal human cancers, in part because it is insensitive to many chemotherapeutic drugs. Gemcitabine still remains the best chemotherapeutic agent available for the treatment of advanced pancreatic cancer. However, gemcitabine treatment results in only a marginal survival advantage. Thus, there is a strong need for the continuous development of novel therapeutic agents...
-
Simulations of flows in the coastal zone of the Baltic Sea
Open Research DataThe study area is located in the Southern Baltic, within Polish Marine Areas, adjacent to the coastline in the vicinity of Lubiatowo village, where The Coastal Research Station (CRS) – a field laboratory of the Institute of Hydro-Engineering of the Polish Academy of Sciences (IBW PAN) –is situated. The numerical reconstruction of the coastal flow was...
-
Milky Sap of Greater Celandine (Chelidonium majus L.) and Anti-Viral Properties
PublicationThe milky juice of the greater celandine herb has been used in folk medicine and in homeopathy for treatment of viral warts for years. However, classical medicine fails to use properties of celandine herbs in treatment of diseases induced by papilloma viruses. Nevertheless, dermatological outpatient clinics are regularly visited by patients reporting efficacy of milky sap isolated from celandine herb in treatment of their own...
-
Effect of Compounding Conditions on Static and Dynamic Mechanical Properties of High Density Polyethylene/Ground Tire Rubber Blends
PublicationSearching for new and cost-effective methods of waste rubber recycling is a subject of research in many scientific centers in the world. In this paper there are presented results of the research of the extrusion process of cheap and environmentally friendly thermoplastic compositions containing 50 % wt. of masses of ground tire rubber (GTR). The aim of this study was to determine the relationship between the mixing conditions and...
-
Analysis of aircraft magnetic interference
PublicationThe magnetometric method is used among other things on mobile platforms (planes, helicopters) in military systems and in geological research. Optically-pumped and SQUID magnetometers are used in magnetic systems on airplanes. To be able to attain the sensitivity of modern magnetometers in flight, it is important that maneuver-related magnetic interference effects be minimized. The mathematical model of an aircraft as a source of...
-
Superexcited states in the vacuum-ultraviolet photofragmentation of isoxazole molecules
PublicationThe photofragmentation of isoxazole molecules producing excited atomic and molecular fragments has been investigated over the energy range 16-50 eV, using photon-induced fluorescence spectroscopy. The following fragments have been identified by their fluorescence: the excited hydrogen atoms H(n), n = 3-7 and the diatomic CH(A2Δ, B2Σ−), CN(B2Σ+) and C2(d3Πg) fragments. The diatomic fragments are vibrationally and highly rotationally...
-
Influence of a lipid bilayer on the conformational behavior of amphotericin B derivatives - A molecular dynamics study.
PublicationAmphotericin B (AmB) is an effective but very toxic antifungal antibiotic. In our laboratory a series of AmB derivatives of improved selectivity of action was synthesized and tested. To understand molecular basis of this improvement, comparative conformational studies of amphotericin B and its two more selectivederivatives were carried out in an aqueous solution and in a lipid membrane. These molecular simulation studies revealed...
-
Determination of isoprostanes in exhaled breath condensate samples by liquid chromatography coupled with tandem mass spectrometry
PublicationOxidative stress (OS) is a state of imbalance between continuously generating reactive oxygen species (ROS) during normal cell metabolism and mechanism of detoxifying oxygen radicals through a network of antioxidative enzymes. Isoprostanes are prostaglandin -like substances that are produced in vivo primarily by free radical-induced peroxidation of arachidonic acid. The measurement of isoprostanes in biological fluids and/or tissue...
-
Analysis of aircraft magnetic interference
PublicationThe magnetometric method is used among other things on mobile platforms (planes, helicopters) in military systems and in geological research. Optically-pumped and SQUID magnetometers are used in magnetic systems on airplanes. To be able to attain the sensitivity of modern magnetometers in flight, it is important that maneuver-related magnetic interference effects be minimized. The mathematical model of an aircraft as a source of...
-
Determination of equivalent axle load factors with the use of strain energy of distortion
PublicationThe paper proposes a new method for calculation of equivalent axle load factors based on the analysis of strain energy of distortion induced in road pavements by traffic loads. The main advantage of the method is the more accurate calculation of the effects of multiple axles and super single versus dual tyres. The methodconsiders the location of critical points, at which strain energy of distortion reaches extreme values. When...
-
Interaction of the conserved region 4.2 of sigma(E) with the RseA anti-sigma factor
PublicationEo-E RNA polymerase transcribes a regulon of folding factors for the bacterial envelope and is induced by physical and chemical stresses. The RseA anti-sigma factor inhibits the activity of Esigma(E) RNA, polymerase. It is shown here that the N-terminal portion of sigma(E), residues 1-153, binds core RNA polymerase. RseA interacts with residues 154-191 of sigma(E), a site that is homologous to region 4, the sigma factor binding...
-
A Numerical Model Study on Grasse River Ice Control Structures
PublicationIce jams in the Grasse River have caused the erosion of capping material designed to prevent the resurfacing of the bed sediment in the PCB-contaminated area. Two in-stream ice-control structures are proposed to avoid the jam-induced erosion of the capping material. These two ice-control options are a pier-type ice-control structure and a reconstruction of a small hydropower dam upstream of the capping site. A numerical model study...
-
Effect of Simultaneous Valve Closures in Hydraulic Piping Systems
PublicationThe paper investigates wave interference (between pressure waves) occurring in simple hydraulic systems. Water hammer was induced by simultaneous closure of three valves located at the reservoirs of a “Y” type hydraulic system. Numerical simulations were carried out with the help of the freeware computer package Allievi enabling the reader to replicate results in a direct manner. The influence of the following quantities has been...
-
Redundant information encoding in QED during decoherence
PublicationBroadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. 45, 430 (1927)] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.-Fys. Medd. XII, 8 (1933)], have been studied from the dawn of the theory. However, what happens in between, when a part of the radiation may be observed, as is the case in many real-life situations, has...
-
Singlet Exciton Diffusion in Vacuum-Evaporated Films of Amine-Based Materials as Studied by Photocurrent and Photoluminescence Quenching Methods
PublicationThe singlet exciton diffusion lengths are determined by the photoconductivity as well as the luminescence surface quenching technique, in vacuum‐evaporated layers of (4,4′,4″‐tris(N‐(3‐methylphenyl)‐N‐phenylylamino) triphenylamine) (m‐MTDATA), 4,4′,4″‐tris[2‐naphthyl(phenyl)amino] triphenylamine (2TNATA), and N,N′‐diphenyl‐N,N′‐bis(3‐methylphenyl)‐[1,1′‐biphenyl]‐4,4′‐diamine (TPD) which are frequently used for fabrication of electroluminescent...
-
Stress anisotropy characterisation with the help of Barkhausen effect detector with adjustable magnetic field direction
PublicationIn the paper we describe a novel apparatus for the measurement of the Barkhausen noise (BN) angular dependence, which in turn may be indicative of the stress induced anisotropy of magnetic properties. Such dependence can be further used for the stress distribution evaluation. The change of magnetization direction in the material is obtained by varying the magnetic flux density in two perpendicular yokes of the apparatus. We present...
-
Site-selective magnetic order of neptunium inNp2Ni17
PublicationWe present the results obtained by superconducting quantum interference device (SQUID) magnetometry, specific heat, and Mossbauer spectroscopy measurements carried out on Np2Ni17 polycrystalline samples. We show that long-range magnetic order, with a moment mu((2b)) similar to 2.25 mu(B), occurs below T-N = 17.5 K on the Np (2b) sites. A nontrivial situation is observed in that the other Np sites (2d) do not take part to the order...
-
Information transfer during the universal gravitational decoherence
PublicationRecently Pikovski et al. (Nat Phys 11:668, 2015) have proposed in an intriguing universal decoherence mechanism, suggesting that gravitation may play a conceptually important role in the quantum-to-classical transition, albeit vanishingly small in everyday situations. Here we analyze information transfer induced by this mechanism. We show that generically on short time-scales, gravitational decoherence leads to a redundant information...
-
Planning, Configuration and Usefulness of Microseismic Monitoring on Eastern-Europe Platform – Example from East Pomerania
PublicationThe microseismic monitoring is a method of monitoring of fracture propagation during hydraulic fracturing process. The method uses array of geophones to localize micro tremors induced by liquid pumped underground at high rate and pressure. The acquired information helps to optimize fracturing process and prevents fracture growth to aquifer levels. It proved to be useful on several unconventional hydrocarbon reservoirs in the USA....
-
Engineering method of tire rolling resistance evaluation
PublicationTire rolling resistance is one of the most difficult tire parameters to measure. The reason is that for modern tires the force of rolling resistance corresponds to 0.5–1% of tire load, thus measurements of very small forces must be performed in a heavily loaded system. This constitutes great problems, especially in road conditions. Laboratory measurements are easier to perform, as the environment may be better controlled, but roadwheel...
-
Laser-Assisted Synthesis and Oxygen Generation of Nickel Nanoparticles
PublicationNowadays, more than ever, environmental awareness is being taken into account when it comes to the design of novel materials. Herein, the pathway to the creation of a colloid of spherical, almost purely metallic nickel nanoparticles (NPs) through pulsed laser ablation in ethanol is presented. A complex description of the colloid is provided through UV-vis spectroscopy and dynamic light scattering analysis, ensuring insight into...
-
Folding‐upon‐repair DNA nanoswitches for monitoring DNA repair enzymes activity
PublicationWe demonstrate here a new class of DNA‐based nanoswitches that, upon enzymatic repair, could undergo a conformational change mechanism leading to a change in fluorescent signal. Such folding‐upon‐repair DNA nanoswitches are synthetic DNA sequences containing O6‐methyl‐guanine (O6‐MeG) nucleobases and labelled with a fluorophore/quencher optical pair. The nanoswitches are rationally designed so that only upon enzymatic demethylation...
-
Influence of Gaps’ Geometry Change on Leakage Flow in Axial Piston Pumps
PublicationAxial piston pumps are the core elements of most medium and high-pressure hydraulic systems. High volumetric efficiency and high working pressures are the main advantages of this type of pumps. Therefore it is necessary to accurately calculate the leakage flow through the gaps to design efficient high-pressure pump. The main difficulty of such calculations is the fact, that the gaps change their geometry during pumping process....
-
Application of the Mathar method to identify internal stress variation in steel as a welding process result
PublicationThe paper deals with the method to identify internal stresses in two-dimensional steel members. Steel members were investigated in the delivery stage and after assembly, by means of electric-arc welding. In order to perform the member assessment two methods to identify the stress variation were applied. The first is a non-destructive measurement method employing local external magnetic field and to detecting the induced voltage,...
-
Influence of anisotropic stiffness in numerical analyses of tunneling and excavation problems in stiff soils
PublicationIn the stiff overconsolidated soil deposits anisotropy influences small and intermediate strain stiffness and hence it has important impact on the results of discplacement preditcions in soil-structure modelling. The authors developed a cross-anisotropic soil model which combines both stress dependent and micro-structural anisotropy. The model is based on the anisotropic hyperelastic kernel for small strain stiffness. Reference...
-
DEVELOPMENT OF A COUPLED NUMERICAL AND EXPERIMENTAL APPROACH TO HYDRODYNAMIC NOISE ESTIMATION
PublicationThe hydroacoustic signature of ships' propellers can be estimated experimentally through measurements of cavitation-induced pressure fluctuations and the corresponding noise distributions at model scale. These measurements need to be performed in a cavitation tunnel under the propellers operating conditions and are quite sensitive and challenging to perform with sufficient accuracy. In comparison, the numerical approach can be...
-
The effect of high pressure at subzero temperature on proteins solubility, drip loss and texture of fish (cod and salmon) and mammal’s (pork and beef) meat
PublicationOne of the possibilities of using high pressure technique in inactivation of microorganism is conducting this process at subzero temperature. However, for its practical application in meat preservation the appropriate properties of meat should be kept. Therefore, the aim of this work was to examine the effect of pressure at subzero temperature (without freezing of water) on proteins and texture of mammal’s and cold-adapted fish...
-
Environmental Fate of Two Psychiatric Drugs, Diazepam and Sertraline: Phototransformation and Investigation of their Photoproducts in Natural Waters
PublicationExperimental studies were conducted to investigate the photodegradation of diazepam and sertraline, two of the most frequently used psychiatric drugs, induced by xenon lamp irradiation, which overlap the sunlight spectra, and natural sunlight. Degradation kinetics was established indicating the occurrence of autocatalytic reactions. The application of liquid chromatography coupled to quadrupole time-of-flight mass spectrometry...
-
SHORT REVIEW AND 3-D FEM ANALYSIS OF BASIC TYPES OF FOUNDATION FOR OFFSHORE WIND TURBINES
PublicationSome problems of the foundations of offshore wind turbines are considered in this paper. A short review is presented on the two basic types of foundations, i.e. monopiles and gravity foundations, including their basic features and applications as well as general design considerations. Also, some issues regarding analysis are discussed, including geotechnical problems and modelling techniques. A numerical model of offshores turbine...
-
The effect of freeze-drying and storage on lysozyme activity, lactoferrin content, superoxide dismutase activity, total antioxidant capacity and fatty acid profile of freeze-dried human milk
PublicationPooled human milk samples were freeze-dried and stored for 6 weeks at a temperature of 5 C and 25 C. Freeze-drying decreased the water content of milk by 86.5%, and the obtained lyophilizate was readily soluble in water. The freeze-drying process did not affect superoxide dismutase (SOD) activity, fatty acid (FA) profile or lactoferrin (LF) content, but it decreased total antioxidant capacity (TAC) of human milk by 22.1% and induced...
-
Carboxylation Enhances Fragmentation of Furan upon Resonant Electron Attachment
PublicationWe report a dissociative electron attachment study to 2-furoic acid (C5H4O3) isolated in a gas phase, which is a model molecule consisting of a carboxylic group and a furan ring. Dissociation of furan by low energy electrons is accessible only via electronic excited Feshbach resonances at energies of incident electrons above 5 eV. On the other hand, carboxylic acids are well- known to dissociate via attachment of electrons at subexcitation energies....
-
Interpolation methods in GPR tomographic imaging of linear and volume anomalies for cultural heritage diagnostics
PublicationThis paper presents results of a ground penetrating radar (GPR) survey conducted in St. Joseph’s Church in Gdańsk, Poland. The aim of the study was to produce tomographic imaging of a renovated floor as well as the objects buried under the floor to detect linear and volume inclusions. The assumed track spacing was meaningfully greater than the single signal spacing in each track, which induced the need for interpolation methods...
-
Solution of the dike-break problem using finite volume method and splitting technique
PublicationIn the paper the finite volume method (FVM) is presented for the solution of two-dimensional shallow water equations. These equations are frequently used to simulate the dam-break and dike-break induced flows. The applied numerical algorithm of FVM is based on the wave-propagation algorithm which ensures a stable solution and simultaneously minimizes the numerical errors. The dimensional decomposition according to the coordinate...
-
Magnetism from fundamentals to spintronics 22/23
e-Learning Courses1. Basic magnetic quantities2. Magnetism of atoms and molecules, atoms in external magnetic fields3. Solid state magnetism, types of magnetic materials (dia-, para-, and ferromagnetism)4. Ferromagnetism and domain structures5. Magnetism of small particles, single domain particles (StonerWohlfarth model), thin films6. Experimental techniques of magnetic properties and magnetisation state determination. Domain structurevisualisation...
-
A Noded Carbon Emission Tool (NCET) to Measure Embodied Carbon (EC) in Compositional Cementitious Materials
PublicationThe ever evolving modern construction industry is now producing the highest levels of carbon content adversely affecting the construction associated environment. Although, the impact of carbon induced emission is quite large, but still not enough measurable standards and tools to scale these emission are available. This study contributes to the body of knowledge by providing a Grasshopper based definition to calculate the embodied...
-
Evaluation of excessive noise effects on hearing employing psychoacoustic dosimetry
PublicationResearch results regarding the noise impact on hearing applying the concept of the Psychoacoustic Noise Dosimetry (PND) are presented. The general characteristics of the PND algorithm are discussed. Additionally, the results of hearing examinations conducted in the laboratory conditions are shown. The main objective of the research was to determine the time needed for the Temporary Threshold Shift to reverse. The results were used...
-
Application of modern sample-preparation techniques to the determination of chloropropanols in food samples
PublicationChloropropanols are heat-induced food toxicants that recently caused concern among industrial and scientific experts. World and European organizations related to food safety asked researchers to investigate mitigation strategies regarding these contaminants. The essential objective of this project was development of fast analytical methods enabling reliable determination and quantification of 3-monochloropropane-1,2-diol, 2-monochloropropane-1,3-diol...
-
Acoustic heating produced in the thermoviscous flow of a bingham plastic
PublicationThis study is devoted to the instantaneous acoustic heating of a Bingham plastic. The model of the Bingham plastic's viscous stress tensor includes the yield stress along with the shear viscosity, which differentiates a Bingham plastic from a viscous Newtonian fluid. A special linear combination of the conservation equations in differential form makes it possible to reduce all acoustic terms in the linear part of of the final equation...
-
Focused ion beam-based microfabrication of boron-doped diamond single-crystal tip cantilevers for electrical and mechanical scanning probe microscopy
PublicationIn this paper, the fabrication process and electromechanical properties of novel atomic force microscopy probes utilising single-crystal boron-doped diamond are presented. The developed probes integrate scanning tips made of chemical vapour deposition-grown, freestanding diamond foil. The fabrication procedure was performed using nanomanipulation techniques combined with scanning electron microscopy and focused ion beam technologies....
-
Structural and electrochemical heterogeneities of boron-doped diamond surfaces
PublicationThis brief review is focussed on the recent progress in studies of the heterogeneous electrochemical behaviour of various boron-doped materials extending from zero-dimensional particles through polycrystalline or nanostructured three-dimensional surfaces. A boron-doped diamond reveals large heterogeneities induced by numerous factors, inter alia multi-faceted crystallinity, inhomogeneous boron concentration, sp2/sp3-carbon ratio,...
-
Interventions reducing car usage: Systematic review and meta-analysis
PublicationThis systematic literature review aimed to investigate the extent to which transport-related interventions induced a reduction in car use. Both qualitative synthesis and meta-analysis were employed. The synthesis included 31 original studies, while the meta-analysis included 21. Of the qualitatively synthesised studies, 74 % demonstrated that interventions were effective in reducing car use. The pooled estimates of the effects...