2021 - Repozytorium publikacji - Politechnika Gdańska

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No Evidence for Sex-specificity in Vitamin C, E and Fatty Acid Content of Human Milk from Healthy Polish Mothers
- Maciej Zagierski
- Anna Krukowska
- Karolina Kawska
- Dorota Martysiak-Żurowska
- Katarzyna Sznurkowska
- Agnieszka Szlagatys-Sidorkiewicz
2021 Pełny tekst JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION
Human milk (HM) is a complex fluid that meets the nutritional needs of infants. Its composition idrfs associated with environmental, maternal, and foetal variables. It provides nutrients and bioactive substances, including cytokines, immunoglobulins, and constituents with antioxidative properties. Boys are reportedly more susceptible to oxidative stress. This study aimed to determine the relationship between infant sex and the antioxidants vitamins C and E, and the fatty acid (FA) profile of HM. Results of this investigation may infer sex differences for the composition of infant formulas. Thirty days after delivery, a sample of HM was collected from 152 healthy, non-smoking mothers of full-term new-borns (77 males) born in good clinical condition. After FAs were extracted from the fat component, they were converted into methyl esters and separated using high-performance gas chromatography. Tocopherol content was determined using a method described in a previous study. Vitamin C content was determined using reversed-phase high-performance liquid chromatography with ultraviolet detection, as described in the same study. The study groups (male versus female offspring) did not differ in terms of vitamin and FA content in HM. The only difference found was in gondoic acid 20:1 (n-9), with a higher concentration in the HM of mothers with female offspring (mean 0.63 ± 0.18 versus 0.59 ± 0.15 g/100 g FA; p < 0.047). Despite the acknowledged differences in the composition of HM associated with infant sex and the increased oxidative stress in males, antioxidant content did not appear to differ according to infant sex. These results suggest that there is no need for the antioxidant content of infant formulas to be sex specific.
Nomination Dossier, The Modernist Centre of Gdynia, Part 2b, History and Development
- Maria Sołtysik
2021
History and development of Gdynia, from Medieval times up until today. The project concerns such chapters as: Introduction; The village of Gdynia; Gdynia as a seaside resort; Construction of the port and the city in the interwar period; The modernist city centre – layout; architecture;Architecture of the city centre; South Pier and Grand District; Post-war development of Śródmieście: a continuation
NOMINATION DOSSIER, The Modernist Centre of Gdynia, parts 4 - 7
- Robert Hirsch
- Celina Łozowska
- Anna Orchowska-Smolińska
- Katarzyna Piotrowska
- Maria Sołtysik
2021
The city of Gdynia is commonly known in Poland as a symbol of the country’s independence and evidence of the foresight of planners and politicians. It is the outcome of the efforts and aspirations of generations of people from all kinds of backgrounds who made Gdynia their home. Document prepared by researchers from Gdansk University of Technology and other experts is the important part of the Nomination Dossier prepared for international official bodies (ICOMOS, UNESCO) to present the city, its assets and current state of protection.
Non-Coaxially Rotating Motion in Casson Martial along with Temperature and Concentration Gradients via First-Order Chemical Reaction
- Noman Jabbar
- Muhammad Bilal Hafeez
- Sameh Askar
- Umar Nazir
2021 Pełny tekst ENERGIES
The effect of non-coaxial rotation on the transport of mass subjected to first-order chemical reaction is studied analytically. The effects of thermal radiation, buoyancy, constructive and destructive chemical reactions along with Casson fluid in rotating frame are discussed. Time evolution of primary and secondary velocities, energy and solute particles are analyzed. The behavior of flow under the variation of intensity of magnetic field is also investigated. Evolutionary behavior of primary velocity is opposite to the evolutionary behavior of secondary velocity. The impact of buoyant force on primary velocity is opposite to the role of buoyant force on the secondary velocity. The evolutionary behavior of temperature is also examined and a remarkable enhancement in temperature is noticed. Thermal radiation causes the fluid to be cooled down as heat energy is escaped by thermal radiation. Evolutionary behavior of concentration is also analyzed and an increasing of concentration versus time is noted. Destructive chemical reaction results a remarkable reduction in the concentration and vice versa for generative chemical reaction.
Non-Destructive Diagnostics of Concrete Beams Strengthened with Steel Plates Using Modal Analysis and Wavelet Transform
- Magdalena Knak
- Erwin Wojtczak
- Magdalena Rucka
2021 Pełny tekst Materials
Externally bonded reinforcements are commonly and widely used in civil engineering objects made of concrete to increase the structure load capacity or to minimize the negative effects of long-term operation and possible defects. The quality of adhesive bonding between a strengthened structure and steel or composite elements is essential for effective reinforcement; therefore, there is a need for non-destructive diagnostics of adhesive joints. The aim of this paper is the detection of debonding defects in adhesive joints between concrete beams and steel plates using the modal analysis approach. The inspection was based on modal shapes and their further processing with the use of continuous wavelet transform (CWT) for precise debonding localization and imaging. The influence of the number of wavelet vanishing moments and the mode shape interpolation on damage imaging maps was studied. The results showed that the integrated modal analysis and wavelet transform could be successfully applied to determine the exact shape and position of the debonding in the adhesive joints of composite beams.
Nondestructive methods complemented by FEM calculations in diagnostics of cracks in bridge approach pavement
- Mikołaj Miśkiewicz
- Karol Daszkiewicz
- Jacek Lachowicz
- Paweł Tysiąc
- Piotr Jaskuła
- Krzysztof Wilde
2021 AUTOMATION IN CONSTRUCTION
Nondestructive methods of road pavement diagnostics are an alternative to traditional approach to pavement failure investigation. The article presents a detailed multidisciplinary inspection carried out using ground-penetrating radar (GPR), laser scanning technology and finite element method (FEM) calculations. It was done in order to assess the factors that contributed to occurrence of premature cracks of a bridge approach pavement. Assessments of permittivity values in the GPR method are dependent on two factors: thickness of successive layers and electromagnetic wave reflection in time. Electromagnetic field propagation in the pavement structure was also simulated using two numerical models: the first one reflected the undamaged pavement, while the second one included the defects next to the bridge joint. The comparison of the radargrams for both models enables identification of reflections and anomalies caused by the assumed defects. Nonhomogeneous compaction zones in the bridge approach pavement structure were detected by analysis of layer permittivity and anomalies observed in the in situ GPR maps. The GPR measurements were positively verified afterwards by values of air void content in the pavement layers, determined in standard invasive tests. Laser scanning technology was also used in the distressed area in order to assess its geometric changes. Results are presented in the form of contour plots depicting differences between the measured and the designed surfaces. The three-dimensional finite element (FE) model of the approach pavement was created to determine pavement deformation under moving load and stress state next to the bridge joint. The influence of insufficient support of the top asphalt layers on pavement response was investigated. The analysis of the cracks shows that some errors were made both during the design process and construction of the bridge approach pavement.
Non-destructive Testing of Wooden Elements
- Monika Zielińska
- Magdalena Rucka
2021 Pełny tekst IOP Conference Series: Materials Science and Engineering
Examining the condition of wooden elements is crucial from the perspective of proper structure performance. If the deterioration in the internal wood condition, which displays no symptoms visible from the outside, is detected, the further spread of the deterioration can be prevented. Test results often point to the necessity of conducting repairs and, renovations, replacing the structure of wooden beams, or even substituting a significant part of the structure. To achieve acceptable results, test methods should take into account the anisotropic nature of wood, which includes the shape of annual rings, as well as the location of the core in crosssection. To adopt methods based on physical effects, profound knowledge of wood physics is needed, particularly of interdependence. Apart from simple tests such as a visual inspection or tapping that are used to determine near-surface defects, non-destructive testing (NDT) plays an important role in the process. This paper presents the methods of non-destructive testing of wooden elements. These methods include tests conducted with ground penetrating radar (GPR), thermal techniques, microwaves, acoustic emission, ultrasonic tomography, and X-ray tomography. The paper summarises the use of non-destructive methods, indicating their advantages, disadvantages as well as some limitations.
Nonlinear Free and Forced Vibrations of a Hyperelastic Micro/Nanobeam Considering Strain Stiffening Effect
- Amin Alibakhshi
- Shahriar Dastjerdi
- Mohammad Malikan
- Victor Eremeev
2021 Pełny tekst Nanomaterials
In recent years, the static and dynamic response of micro/nanobeams made of hyperelasticity materials received great attention. In the majority of studies in this area, the strain-stiffing effect that plays a major role in many hyperelastic materials has not been investigated deeply. Moreover, the influence of the size effect and large rotation for such a beam that is important for the large deformation was not addressed. This paper attempts to explore the free and forced vibrations of a micro/nanobeam made of a hyperelastic material incorporating strain-stiffening, size effect, and moderate rotation. The beam is modelled based on the Euler–Bernoulli beam theory, and strains are obtained via an extended von Kármán theory. Boundary conditions and governing equations are derived by way of Hamilton’s principle. The multiple scales method is applied to obtain the frequency response equation, and Hamilton’s technique is utilized to obtain the free undamped nonlinear frequency. The influence of important system parameters such as the stiffening parameter, damping coefficient, length of the beam, length-scale parameter, and forcing amplitude on the frequency response, force response, and nonlinear frequency is analyzed. Results show that the hyperelastic microbeam shows a nonlinear hardening behavior, which this type of nonlinearity gets stronger by increasing the strain-stiffening effect. Conversely, as the strain-stiffening effect is decreased, the nonlinear frequency is decreased accordingly. The evidence from this study suggests that incorporating strain-stiffening in hyperelastic beams could improve their vibrational performance. The model proposed in this paper is mathematically simple and can be utilized for other kinds of micro/nanobeams with different boundary conditions.
Nonlinear Interaction of Magnetoacoustic Modes in a Quasi-Isentropic Plasma Flow
- Anna Perelomova
2021 Pełny tekst Archives of Acoustics
The nonlinear interaction of magnetoacoustic waves in a plasma is analytically studied. A plasma is an open system. It is affected by the straight constant equilibrium magnetic flux density forming constant angle with the wave vector which varies from 0 till . The nonlinear instantaneous equation which describes excitation of secondary wave modes in the field of intense magnetoacoustic perturbations is derived by use of projecting. There is a diversity of nonlinear interactions of waves in view of variety of wave modes, which may be slow or fast and may propagate in different directions. The excitation is analysed in the physically meaningful cases, that is: harmonic and impulsive exciter, oppositely or accordingly directed dominant and secondary wave modes.
Nonlinear resultant theory of shells accounting for thermodiffusion
- Victor Eremeev
- Wojciech Pietraszkiewicz
2021 Pełny tekst CONTINUUM MECHANICS AND THERMODYNAMICS
The complete nonlinear resultant 2D model of shell thermodiffusion is developed. All 2D balance laws and the entropy imbalance are formulated by direct through-the-thickness integration of respective 3D laws of continuum thermodiffusion. This leads to a more rich thermodynamic structure of our 2D model with several additional 2D fields not present in the 3D parent model. Constitutive equations of elastic thermodiffusive shells are discussed in more detail. They are formulated from restrictions imposed by the resultant 2D entropy imbalance according to Coleman–Noll procedure extended by a set of 2D constitutive equations based on heuristic assumptions.
Nonlocal elasticity analysis of moderately thick porous functionally graded plates in a hygro-thermal environment
- Shahriar Dastjerdi
- Mohammad Malikan
- Rossana Dimitri
- Francesco Tornabene
2021 Pełny tekst COMPOSITE STRUCTURES
This work performs a novel quasi three-dimensional (3D) bending analysis for a moderately thick functionally graded material (FGM) made of nanoceramics and metal powders, in presence of porosities due to some incorrect manufacturing processes. Such porosities can appear within the plate in two forms, namely, even and uneven distributions. The modeled system assumes a polymer matrix where both shear and transverse factors coexist. The bending equations are obtained by using the Hamiltonian principle. In order to apply the quantum effects for the nanosystem, the well-known nonlocal theory of Eringen is simply assumed, while checking for its numerical accuracy. A physically-consistent analysis of the nanostructures would investigate possible surrounding effects. Thus, the thermal and humidity influence is accounted for the 3D problem, whose governing equations are solved through a semi-analytical polynomial method (SAPM), as recently proposed in literature for different applications. The proposed method is based on a simple procedure with very accurate numerical outcomes, whose performance is checked against the available literature. After computing the deflection relations, a systematic study is performed for the bending response of nanoporous FGMs in a hygro-thermal surrounding environment, with promising results for practical applications.
Non-Newtonian Mathematics Instead of Non-Newtonian Physics: Dark Matter and Dark Energy from a Mismatch of Arithmetics
- Marek Czachor
2021 Pełny tekst Foundations of Science
Newtonian physics is based on Newtonian calculus applied to Newtonian dynamics. New paradigms such as ‘modified Newtonian dynamics’ (MOND) change the dynamics, but do not alter the calculus. However, calculus is dependent on arithmetic, that is the ways we add and multiply numbers. For example, in special relativity we add and subtract velocities by means of addition β1⊕β2=tanh(tanh−1(β1)+tanh−1(β2)), although multiplication β1⊙β2=tanh(tanh−1(β1)⋅tanh−1(β2)), and division β1⊘β2=tanh(tanh−1(β1)/tanh−1(β2)) do not seem to appear in the literature. The map fX(β)=tanh−1(β) defines an isomorphism of the arithmetic in X=(−1,1) with the standard one in R. The new arithmetic is projective and non-Diophantine in the sense of Burgin (Uspekhi Matematicheskich Nauk 32:209–210 (in Russian), 1977), while ultrarelativistic velocities are super-large in the sense of Kolmogorov (Technika Molodezhi 10:16–19 (11:30–33 in Russian), 1961). Velocity of light plays a role of non-Diophantine infinity. The new arithmetic allows us to define the corresponding derivative and integral, and thus a new calculus which is non-Newtonian in the sense of Grossman and Katz (Non-Newtonian calculus, Lee Press, Pigeon Cove, 1972). Treating the above example as a paradigm, we ask what can be said about the set X of ‘real numbers’, and the isomorphism fX:X→R, if we assume the standard form of Newtonian mechanics and general relativity (formulated by means of the new calculus) but demand agreement with astrophysical observations. It turns out that the observable accelerated expansion of the Universe can be reconstructed with zero cosmological constant if fX(t/tH)≈0.8sinh(t−t1)/(0.8tH). The resulting non-Newtonian model is exactly equivalent to the standard Newtonian one with ΩΛ=0.7, ΩM=0.3. Asymptotically flat rotation curves are obtained if ‘zero’, the neutral element 0X of addition, is nonzero from the point of view of the standard arithmetic of R. This implies f−1X(0)=0X>0. The opposition Diophantine versus non-Diophantine, or Newtonian versus non-Newtonian, is an arithmetic analogue of Euclidean versus non-Euclidean in geometry. We do not yet know if the proposed generalization ultimately removes any need of dark matter, but it will certainly change estimates of its parameters. Physics of the dark universe seems to be both geometry and arithmetic.
Non-Satellite Broadband Maritime Communications for e-Navigation Services
- Michał Hoeft
- Krzysztof Gierłowski
- Jacek Rak
- Józef Woźniak
- Krzysztof Nowicki
2021 Pełny tekst IEEE Access
The development of broadband network access technologies available to users on land has triggered a rapid expansion of a diverse range of services provided by terrestrial networks. However, due to limitations of digital communication technologies in the off-shore area, the maritime ICT systems evolution so far has not followed that trend. Despite the e-navigation initiative defining the set of Maritime Services, the progress in the maritime ICT systems evolution has been slow. Only a few systems, including the VHF Data Exchange System (VDES), or the TRI-Media Telematic Oceanographic Network (TRITON) have been proposed to extend the basic set of services offered by classical radio-communication solutions. However, all those systems have significant limitations. The purpose of this paper is to introduce the netBaltic system designed as a fully heterogeneous system for modern maritime communications. Its unique feature is the capability to transparently use different communication technologies to efficiently support maritime ICT services, as well as openness for the incorporation of future communication technologies. The paper presents an overview of VDES, TRITON and netBaltic systems and analysis showing their expected strengths and weaknesses. The systems are then compared in simulated environments, illustrating real-world usage scenarios based on real maritime traffic information and performance measurements obtained during off-shore measurement campaigns. Results indicate that netBaltic seems to be the most versatile one and is capable of offering access to all services defined by International Maritime Organization, due to its ability to use different communication technologies simultaneously and functionality offered by its Delay Tolerant Networking component.
Normalized Partial Scattering Cross Section for Performance Evaluation of Low-Observability Scattering Structures
- Muhammad Abdullah
- Sławomir Kozieł
- Stanisław Szczepański
2021 Pełny tekst Electronics
The development of diffusion metasurfaces created new opportunities to elevate the stealthiness of combat aircraft. Despite the potential significance of metasurfaces, their rigorous design methodologies are still lacking, especially in the context of meticulous control over the scattering of electromagnetic (EM) waves through geometry parameter tuning. Another practical issue is insufficiency of the existing performance metrics, specifically, monostatic and bistatic evaluation of the reflectivity, especially at the design stage of metasurfaces. Both provide limited insight into the RCS reduction properties, with the latter being dependent on the selection of the planes over which the evaluation takes place. This paper introduces a novel performance metric for evaluating scattering characteristics of a metasurface, referred to as Normalized Partial Scattering Cross Section (NPSCS). The metric involves integration of the scattered energy over a specific solid angle, which allows for a comprehensive assessment of the structure performance in a format largely independent of the particular arrangement of the scattering lobes. We demonstrate the utility of the introduced metric using two specific metasurface architectures. In particular, we show that the integral-based metric can be used to discriminate between the various surface configurations (e.g., checkerboard versus random), which cannot be conclusively compared using traditional methods. Consequently, the proposed approach can be a useful tool in benchmarking radar cross section reduction performance of metamaterial-based, and other types of scattering structures.
Novel 1,2,3-Triazole Derivatives as Mimics of Steroidal System—Synthesis, Crystal Structures Determination, Hirshfeld Surfaces Analysis and Molecular Docking
- Mateusz Daśko
- Anna Dołęga
- Magdalena Siedzielnik
- Karol Biernacki
- Olga Ciupak
- Janusz Rachoń
- Sebastian Demkowicz
2021 Pełny tekst MOLECULES
Herein, we present the synthesis and crystal structures determination of five 4-(1-phenyl-1H-1,2,3-triazol-4-yl)phenol derivatives containing halogen atoms, 6a–e, which may be used as an excellent mimic of steroids in the drug development process. Good quality crystals obtained for all of the synthesized compounds allowed the analysis of their molecular structures. Subsequently, the determined crystal structures were used to calculate the Hirshfeld surfaces for each of the synthesized compounds. Furthermore, results of our docking studies indicated that synthesized derivatives are able to bind effectively to the active sites of selected enzymes and receptors involved in the hormone biosynthesis and signaling pathways, analogously to the native steroids.
Novel “acid tuned” deep eutectic solvents based on protonated L-proline
- Patrycja Janicka
- Andrzej Przyjazny
- Grzegorz Boczkaj
2021 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS
The paper presents new types of deep eutectic solvents (DESs) based on L-proline protonated using three different acids (hydrochloric, sulfuric and phosphoric)and playing the role of a hydrogen bond acceptor(HBA). Glucose and xylitol were used as hydrogen bond donors (HBD). A series of deep eutectic solvents with various mole ratios were obtained for the systems L-proline: glucose and L-proline: xylitol. Density, melting point, pH and viscosity of the synthesized DESs were determined along with the effect of water content, mole fraction of the HBA in DES and temperature on properties of the DESs. A wide range of densities (1343-1606 kg/m3), viscosities at 20°C (699.6-48,590 mPa·s) and pH of 0.1M DES solutions (1.578-2.456) make the obtained deep eutectic solvents potentially applicable in numerous technological processes, extractions as well as in analytical techniques, including microextraction. Components of these DESs are of natural origin and non-toxic, thus environmentally friendly and suitable for food as well as pharmaceutical industry.
Novel analytical approach for real-time monitoring of volatile Maillard reaction products emitted from the sugar-amino acid model system using proton transfer reaction mass spectrometry
- Anna Banaszkiewicz
- Tomasz Majchrzak
2021
In the presented research, volatile Maillard reaction products formation in the two sugar-amino acid model systems, namely glucoselysine and ribose-lysine model systems were investigated using proton transfer reaction mass spectrometry. Obtained data were supported by the reference method, i.e., UV/Vis spectrometry. A number of volatile organic compounds were selected based on the correlation of the effect of Maillard reaction conditions and model system concentration with the emission of characteristic volatiles. It was demonstrated that the ribose-lysine model system was more reactive than the glucose-lysine model system which resulted in the high concentration of volatiles, such as acetonitrile, acetaldehyde, and 2,3-pentanedione. Characteristic volatile Maillard reaction products were observed only in the ribose–lysine model system: 2,3-butanedione and 3-methylbutanal, while methylfuran was characteristic for the glucose–lysine model system. Absorbance measurements revealed a correlation between the browning of the model systems and the emission of selected volatile Maillard reaction products
Novel Cast Polyurethanes Obtained by Using Reactive Phosphorus-Containing Polyol: Synthesis, Thermal Analysis and Combustion Behaviors
- Izabela Zagożdżon
- Paulina Parcheta
- Janusz Datta
2021 Pełny tekst Materials
Phosphorus-containing polyol applications in polyurethane synthesis can prevent volatilization of flame retardants and their migration on the surface of a material. In this work, novel cast polyurethanes were prepared by a one-step method with the use of different amounts of phosphorus-containing polyol, 4,4′–diphenylmethane diisocyanate and 1,4-butanediol. The chemical structure, thermal, physicochemical and mechanical properties and flame resistance of the prepared materials were investigated. The results obtained for cast flame-retarded polyurethanes were compared with cast polyurethane synthesized with commonly known polyether polyol. It has been shown that with an increasing amount of phosphorus content to polyurethane’s chemical structure, an increased flame resistance and char yield were found during combustion tests. Phosphorus polyol worked in both the condensed (reduced heat and mass exchange) and gas phase (inhibition of flame propagation during burning). The obtained materials contained phosphorus polyol, indicating higher thermal stability in an oxidative environment than an inert atmosphere.
Novel Cold Crucible Ultrasonic Atomization Powder Production Method for 3D Printing
- Łukasz Żrodowski
- Rafał Wróblewski
- Tomasz Choma
- Bartosz Morończyk
- Mateusz Ostrysz
- Marcin Leonowicz
- Wojciech Łacisz
- Piotr Błyskun
- Jan S. Wróbel
- Grzegorz Cieślak
- Bartłomiej Wysocki
- Cezary Żrodowski
- Karolina Pomian
2021 Pełny tekst Materials
: A new powder production method has been developed to speed up the search for novel alloys for additive manufacturing. The technique involves an ultrasonically agitated cold crucible installed at the top of a 20 kHz ultrasonic sonotrode. The material is melted with an electric arc and undergoes pulverization with standing wave vibrations. Several different alloys in various forms, including noble and metallic glass alloys, were chosen to test the process. The atomized particles showed exceptional sphericity, while powder output suitable for additive manufacturing reached up to 60%. The AMZ4 metallic glass powder remained amorphous below the 50 μm fraction, while tungsten addition led to crystallization in each fraction. Minor contamination and high Mn and Zn evaporation, especially in the finest particles, was observed in atomized powders. The innovative ultrasonic atomization method appears as a promising tool for material scientists to develop powders with tailored chemical composition, size and structure.
Novel Diazocrowns with Pyrrole Residue as Lead(II) Colorimetric Probes
- Błażej Galiński
- Elżbieta Luboch
- Jarosław Chojnacki
- Ewa Wagner-Wysiecka
2021 Pełny tekst Materials
Novel 18- and 23-membered diazomacrocycles were obtained with satisfactory yields by diazocoupling of aromatic diamines with pyrrole in reactions carried under high dilution conditions. X-ray structure of macrocycle bearing five carbon atoms linkage was determined and described. Compounds were characterized as chromogenic heavy metal ions receptors. Selective color and spectral response for lead(II) was found in acetonitrile and its mixture with water. Complexation properties of newly obtained macrocycles with a hydrocarbon chain were compared with the properties of their oligoether analogs. The influence of the introduction of hydrocarbon residue as a part of macrocycle on the lead(II) binding was discussed. Selective and sensitive colorimetric probe for lead(II) in aqueous acetonitrile with detection limit 56.1 mg/L was proposed.