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Comparative 3D DEM simulations of sand–structure interfaces with similarly shaped clumps versus spheres with contact moments.
PublicationThree-dimensional simulations of a monotonic quasi-static interface behaviour between initially dense cohesionless sand and a rigid wall of different roughness during tests in a parallelly guided direct shear test under constant normal stress are presented. Numerical modelling was carried out by the discrete element method (DEM) using clumps in the form of convex non-symmetric irregularly shaped grains. The clumps had an aspect...
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Recent Advances in Loop Heat Pipes with Flat Evaporator
PublicationThe focus of this review is to present the current advances in Loop Heat Pipes (LHP) with flat evaporators, which address the current challenges to the wide implementation of the technology. A recent advance in LHP is the design of flat-shaped evaporators, which is better suited to the geometry of discretely mounted electronics components (microprocessors) and therefore negate the need for an additional transfer surface (saddle)...
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Fatigue fracture morphology of AISI H13 steel obtained by additive manufacturing
PublicationThe paper focuses on researching the effect of fatigue loading on metallic structure, lifetime, and fracture surface topographies in AISI H13 steel specimens obtained by selective laser melting (SLM). The topography of the fracture surfaces was measured over their entire area, according to the entire total area method, with an optical three-dimensional surface measurement system. The fatigue results of the SLM 3D printed steel...
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The experience of movement in orbital space architecture: A narrative of weightlessness
PublicationBased upon a combination of architectural theories, the knowledge of space environment, and psychology of isolated and confined environments, this qualitative research aims to study orbital space settlement in a way to get the built space congenial to the human experience of movement. In this sense, sensors, self-propulsion or mechanical actuators, the inhabitant’s mental and visual capacity for movement, as well as the represented...
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Checkpoints that regulate balanced biosynthesis of lipopolysaccharide and its essentiality in Escherichia coli
PublicationThe outer membrane (OM) of Gram-negative bacteria, such as Escherichia coli, is essential for their viability. Lipopolysaccharide (LPS) constitutes the major component of OM, providing the permeability barrier, and a tight balance exists between LPS and phospholipids amounts as both of these essential components use a common metabolic precursor. Hence, checkpoints are in place, right from the regulation of the first committed step...
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Determination of stepped plate thickness distribution using guided waves and compressed sensing approach
PublicationGuided waves recently have attracted significant interest as a very promising research area. The signals registered by a specially designed sensor network are processed to assess the state of the tested structure. Despite the constant development of novel damage detection algorithms employing guided waves, the phenomenon of wave propagation still needs detailed recognizing and understanding for the further progress of non-destructive...
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Fatigue of titanium alloy Ti6Al4V with diamond structure obtained by Laser Power Bed Fusion method
PublicationThis paper presents the results of fatigue tests conducted on Ti6Al4V titanium alloy with diamond structure obtained by the Laser Power Bed Fusion method. Samples used in tests were printed with porosities: 81%, 73%, 50%, 34% and near-zero porosity. Samples were subjected to cyclic tests with a constant stress amplitude. The number of cycles until sample failure was registered. Obtained fatigue test results made it possible to...
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Single-Phase 15-Level Switched-Capacitor Boost Multilevel Inverter Topology for Renewable Energy Applications
PublicationGalvanic isolation is a vital part of a grid-connected solar PV system. With the growth of multilevel inverters for grid-connected applications, the multilevel inverters having isolation are not sufficiently discussed in the literature. In this paper, a 15-level isolated multilevel inverter topology requiring only thirteen switches is proposed. The envisaged configuration includes two cells, designated as upper and lower cells....
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Determinants of Business Growth Aspirations among Polish Students: An Empirical Analysis
PublicationThis paper aims to discuss the concept of growth aspirations and growth intentions, as well as to identify factors that influence growth aspirations expressed by students with regard to their future businesses. On the basis of a literature review potential determinants of growth aspirations have been identified and tested empirically using data obtained from 223 students from the Pomeranian region in Poland. The authors...
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Safety assessment of a concrete viaduct damaged by vehicle impact and an evaluation of the repair
PublicationDamage to lower parts of viaducts caused by impact from under-passing high vehicles is relatively frequent. One such incident, in which a viaduct was damaged by the impact from a truck with an improperly assembled hydraulic crane, is considered in this work. The analysis is based on a detailed object damage evaluation, 3D laser scanning, and numerical simulations. The aim of the study is to accurately model the vehicle impact into...
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Qualitative analysis of phospholipids and their oxidised derivatives – used techniques and examples of their applications related to lipidomic research and food analysis
PublicationPhospholipids (PLs) are important biomolecules that not only constitute structural building blocks and scaffolds of cell and organelle membranes, but also play a vital role in cell biochemistry and physiology. Moreover, dietary exogenous PLs are characterized by high nutritional value and other beneficial health effects, which are confirmed by numerous epidemiological studies. For this reason, PLs are of high interest in lipidomics...
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Mathematical approach to design 3D scaffolds for the 3D printable bone implant
PublicationThis work demonstrates that an artificial scaffold structure can be designed to exhibit mechanical properties close to the ones of real bone tissue, thus highly reducing the stress-shielding phenomenon. In this study the scan of lumbar vertebra fragment was reproduced to create a numerical 3D model (this model was called the reference bone sample). New nine 3D scaffold samples were designed and their numerical models were created....
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Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application
PublicationThe more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model...
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Two bacterial small heat shock proteins, IbpA and IbpB, form a functional heterodimer
PublicationSmall heat shock proteins (sHsps) are a conserved class of ATP-independent chaperones which in stress conditions bind to unfolded protein substrates and prevent their irreversible aggregation. Substrates trapped in sHsps-containing aggregates are efficiently refolded into native structures by ATP-dependent Hsp70 and Hsp100 chaperones. Most γ-proteobacteria possess a single sHsp (IbpA), while in a subset of Enterobacterales, as...
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Post-Effort Changes in Autophagy- and Inflammation-Related Gene Expression in White Blood Cells of Healthy Young Men
PublicationAcute, strenuous physical exertion requiring high levels of energy production induces the production of reactive oxygen species and metabolic disturbances that can damage the mitochondria. Thus, selective autophagic elimination of defective mitochondria may improve resistance to oxidative stress and potentially to inflammation. The main goal of this study was to evaluate the impacts of intense effort on changes in the expression...
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Historical carpentry corner log joints—Numerical analysis within stochastic framework
PublicationThe paper presents the results of numerical analysis performed on historical, traditional carpentry corner logjoints of two basic topologies: the short-corner dovetail connection and the saddle notch connection. These types of carpentry joints are commonly used in currently preserved objects of wooden architecture. All connections have been modelled in pinewood, which has been defined in the Finite Element software MSC.Marc/Mentat...
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Role of Silicon in Counteracting Cadmium Stress in Pea Plants (Pisum sativum L.): Insights Into Cadmium Binding Mechanisms and Pectin Methylesterase Activity
PublicationPurpose: The aim of this study was to investigate the role of silicon (Si) in counteracting a cadmium (Cd) stress to pea plants (Pisum sativum L.) and to identify the mechanism by which Cd is bound within pea roots. Methods: These goals were achieved through (i) a histochemical study of Cd localization in pea roots, (ii) spectrophotometric determination of pectin content and the activity...
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Rheological, Mechanical, Microstructural and Radiation Shielding Properties of Cement Pastes Containing Magnetite (Fe3O4) Nanoparticles
PublicationThis work examines the influence of iron oxide nanoparticles (Fe3O4 NPs) on neutron and gamma-ray radiation shielding characteristics of Portland cement paste. Experimental evaluations were supplemented with theoretical studies using NXCom program. Portland cement pastes with 5, 10, 15, 20, and 30 wt% of nanomagnetite cement replacement were produced. Moreover, rheological, early strength development, compressive strength, and...
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Review on mechanisms and efficiency of removal of microbiological contaminants in constructed wetlands
PublicationConstructed wetlands (CW) have been considered as a waste and a stormwater treatment systems for small communities or for areas with unsteady sewage flow conditions. Several investigations were undertaken for estimation suspended solids, organic matter and nutrients efficiency removal but only few focused on retention of microorganisms in constructed wetlands. In this review mechanisms of elimination of viruses, indicator bacteria...
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Tree rings as an indicator of atmospheric pollutant deposition to subalpine spruce forests in the Sudetes (Southern Poland)
PublicationIn spite of their moderate altitude (1000–1600m a.s.l.), the Western SudetyMountains belong to areas with the most efficient fog precipitation in Europe. Intense industrial activity in the area of windward western foothills caused an exceptional intensification of atmospheric pollutant deposition via precipitation and fog to take place since the 1950s. In the second half of the 1970s a massive spruce forest dieback began affecting...
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The compositional space of exhaled breath condensate and its link to the human breath volatilome
PublicationBreath analysis is commonly understood to target gaseous or volatile organic compounds (VOCs) for the characterization of different pathologies. Targeted analysis is most effective if a working hypothesis can be based on a plethora of data. The recently published volatilome builds an optimal basis for organizing powerful target sets. However, the origin and pathways of biosynthesis of many VOCs are not known, which complicates...
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Molecular basis of the osmolyte effect on protein stability: a lesson from the mechanical unfolding of lysozyme
PublicationOsmolytes are a class of small organic molecules that shift the protein folding equilibrium. For this reason, they are accumulated by organisms under environmental stress, and find applications in biotechnology where proteins need to be stabilized or dissolved. However, despite years of research, debate continues over the exact mechanisms underpinning the stabilizing and denaturing effect of osmolytes. Here, we simulated the mechanical...
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New Materiality-towards ‘Media Environments
PublicationArticle presents media solutions providing new materiality of architectural spaces. Media solutions in architecture evolve in new forms. Articlepresentsboth the developmentof new technological solutionsas well as new ways of application of media solutions in relation toarchitectural form. The aim of the article is to show technical aspects of new materiality - intelligent materials, allowing transmission of changeable visual content...
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The Influence of Articular Cartilage Thickness Reduction on Meniscus Biomechanics
PublicationObjective Evaluation of the biomechanical interaction between meniscus and cartilage in medial compartment knee osteoarthritis. Methods The finite element method was used to simulate knee joint contact mechanics. Three knee models were created on the basis of knee geometry from the Open Knee project. We reduced the thickness of medial cartilages in the intact knee model by approximately 50% to obtain a medial knee osteoarthritis...
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Influence of grain shape on the mechanical behaviour of granular materials
PublicationWe performed series of numerical vertical compression tests on assemblies of 2D granular material using a Discrete Element code and studied the results in regard to the grain shape. The samples consist of 5000 grains made either of 3 overlapping discs (clump - grain with concavities) or of six-edged polygons (convex grain). These two types of grains have a similar external envelope, ruled with a geometrical parameter α. In the...
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Biomechanical causes for failure of the Physiomesh/Securestrap system
PublicationThis study investigates the mechanical behavior of the Physiomesh/Securestrap system, a hernia repair system used for IPOM procedures associated with high failure rates. The study involved conducting mechanical experiments and numerical simulations to investigate the mechanical behavior of the Physiomesh/Securestrap system under pressure load. Uniaxial tension tests were conducted to determine the elasticity modulus of the Physiomesh...
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Experimental and numerical study on deformed steel columns subjected to impact load during earthquakes
PublicationThe soft-storey failure is one of the most typical types of damage observed in buildings during earthquakes. The failure of an upper soft storey of a structure results in large impact load acting on the lower floors and if the resistance of the structural members of the lower storeys is not sufficient it may further lead to progressive collapse of the whole building. The aim of the present paper is to investigate the dynamic behaviour...
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Fluid structure interaction study of non-Newtonian Casson fluid in a bifurcated channel having stenosis with elastic walls
PublicationFluid–structure interaction (FSI) gained a huge attention of scientists and researchers due to its applications in biomedical and mechanical engineering. One of the most important applications of FSI is to study the elastic wall behavior of stenotic arteries. Blood is the suspension of various cells characterized by shear thinning, yield stress, and viscoelastic qualities that can be assessed by using non-Newtonian models. In this...
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Activation Energy and Inclination Magnetic Dipole Influences on Carreau Nanofluid Flowing via Cylindrical Channel with an Infinite Shearing Rate
PublicationThe infinite shear viscosity model of Carreau fluid characterizes the attitude of fluid flow at a very high/very low shear rate. This model has the capacity for interpretation of fluid at both extreme levels, and an inclined magnetic dipole in fluid mechanics has its valuable applications such as magnetic drug engineering, cold treatments to destroy tumors, drug targeting, bio preservation, cryosurgery, astrophysics, reaction kinetics,...
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Development and validation of lumbar spine finite element model
PublicationThe functional biomechanics of the lumbar spine have been better understood by finite element method (FEM) simulations. However, there are still areas where the behavior of soft tissues can be better modeled or described in a different way. The purpose of this research is to develop and validate a lumbar spine section intended for biomechanical research. A FE model of the 50th percentile adult male (AM) Total Human Model for Safety...
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Mechanical Properties and Residual Stress Measurements of Grade IV Titanium and Ti-6Al-4V and Ti-13Nb-13Zr Titanium Alloys after Laser Treatment
PublicationNowadays, surface engineering focuses on research into materials for medical applications. Titanium and its alloys are prominent, especially Ti-6Al-4V and Ti-13Nb-13Zr. Samples made of pure grade IV titanium and the titanium alloys Ti-6Al-4V and Ti-13Nb-13Zr were modified via laser treatment with laser beam frequency f = 25 Hz and laser beam power P = 1000 W during a laser pulse with duration t = 1 ms. Subsequently, to analyze...
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City scan as a tool to assess resilience challenges and vulnerabilities at the community level
PublicationThe majority of the world’s population lives in cities and cities are the key to achieving resilience. Local governments own only part of the land and can only partially decide about measures that should be taken ‘on the ground’. Local governments are therefore highly dependent on individuals, communities, and businesses to adapt and transform and take action in their own backyards or neighbourhoods. Since, for many people, climate...
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Field Evaluation of High Modulus Asphalt Concrete Resistance to Low-Temperature Cracking
PublicationHigh-modulus asphalt concrete has numerous advantages in comparison to conventional asphalt concrete, including increased resistance to permanent deformations and increased pavement fatigue life. However, previous studies have shown that the construction of road pavements with High Modulus Asphalt Concrete (HMAC) may significantly increase the risk of low-temperature cracking. Those observations were the motivation for the research...
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Experimental study and numerical simulation on porosity dependent direct reducibility of high-grade iron oxide pellets in hydrogen
PublicationThe transition to more environmentally friendly steel production methods has intensified research into hydrogen-based direct reduction (HyDR) of iron oxide pellets. The aim of this study is to systematically investigate the kinetics of the reduction process, the evolution of porosity and the resulting microstructural changes on the reduction behavior of high-quality pellets during HyDR of iron ore at different temperatures. A modified...
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Micro- and nano-Illite to improve strength of untreated-soil as a nano soil-improvement (NSI) technique
PublicationSoil stabilization is a technique of improving the geotechnical properties of soils for various engineering applications. However, conventional stabilizers such as cement and lime have some limitations, such as high cost, environmental impact, and durability issues. Therefore, there is a need for alternative and innovative stabilizers that can overcome these challenges. This study introduces nano-Illite, a type of clay mineral,...
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Tensile and Fatigue Behavior of Additive Manufactured Polylactide
PublicationThis article presents the results of monotonic tensile and fatigue tests conducted on commercial polylactide or polylactic acid (PLA). The results of fatigue tests for this material present in the literature are limited, especially for additive manufactured elements. The specimens were manufactured using the injection molding and the fused filament fabrication (FFF) method. The FFF specimens were divided into five subgroups, depending...
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Burnout as a State: Random-Intercept Cross-Lagged Relationship Between Exhaustion and Disengagement in a 10-Day Study
PublicationBackground: Burnout has been traditionally seen as a chronic and stable state in response to prolonged stress. However, measures of momentary burnout are not well established, even though the within-person approach suggests that the symptoms of burnout may vary from day to day for the same employee. The aim of this study is to examine the daily inter- and intra-personal variability of the symptoms of burnout and the cross-lagged relationship...
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Nondestructive methods complemented by FEM calculations in diagnostics of cracks in bridge approach pavement
PublicationNondestructive 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....
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Environmental characteristics of a tundra river system in Svalbard. Part 2: Chemical stress factors
PublicationBacterial communities in the Arctic environment are subject to multiple stress factors, including contaminants, although typically their concentrations are small. The Arctic contamination research has focused on persistent organic pollutants (POPs) because they are bioaccumulative, resistant to degradation and toxic for all organisms. Pollutants have entered the Arctic predominantly by atmospheric and oceanic long-range transport,...
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Knowledge‐Intensive Business Services (KIBS) and Their Role in the Knowledge‐Based Economy
PublicationThe importance of the knowledge‐intensive business services sector for the development of the economy is growing. In the 80s and 90s this sector became the fastest growing sector in the OECD countries (OECD, 2001). Many publications stress its close relationship to the levels of innovation and performance of the whole economy (e.g. Hipp, 1999; Tomlinson, 1999; Aslesen and Isaksen, 2007). It is an increasingly common belief that...
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Aluminum-TiO2 NPs Composites as Non-precious Catalysts for Efficient Electrochemical Generation of Hydrogen
PublicationIn this paper, we demonstrated, for the first time, aluminum titania nanoparticle (Al-TiO2 NP) composites with variable amounts of TiO2 NPs as nonprecious active catalysts for the electrochemical generation of H2. These materials were synthesized by mixing desired amounts of hydrogen titanate nanotubes (TNTs), fabricated here by a cost-effective approach at moderate hydrothermal conditions, with aluminum powder (purity 99.7%; size...
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A newly-developed model for predicting cutting power during wood sawing with circular saw blades
PublicationIn the classical approach, cutting forces and cutting power in sawing processes of orthotropic materials such as wood are generally calculated on the basis of the specific cutting resistance kc (cutting force per unit area of cut). For every type of sawing kinematics (frame saws, band saws and circular sawing machines) different empirical values of specific cutting resistance kc have to be applied. It should be emphasised that...
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The impact of filler thermomechanical modifications on static and dynamic mechanical performance of flexible foamed polyurethane/ground tire rubber/zinc borate composites
PublicationThe rapid development of the automotive industry is very beneficial to many aspects of human life, but it is also a very significant environmental burden. The most straightforward impact is related to the generation of exhaust, but the management of post-consumer car parts is also a major challenge. Among them, waste tires are very burdensome due to their enormous numbers. Therefore, it is essential to develop novel, environmentally...
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Extreme weather layer method for implementation of nature-based solutions for climate adaptation: Case study Słupsk
PublicationOne of the most severe climate risks that is expected to affect all regions is related to stormwater. Climate models, constructed based on long-term trends, show that extreme weather events such as storms, cloudbursts and a large rise in sea level will be significant in the coming decades. Moreover, even the frequency and intensity of “normal” rainfall events, such as microbursts, are expected to be remarkably higher than today...
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Computer-assisted pronunciation training—Speech synthesis is almost all you need
PublicationThe research community has long studied computer-assisted pronunciation training (CAPT) methods in non-native speech. Researchers focused on studying various model architectures, such as Bayesian networks and deep learning methods, as well as on the analysis of different representations of the speech signal. Despite significant progress in recent years, existing CAPT methods are not able to detect pronunciation errors with high...
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Impact of abiotic stressors on nutrient removal and rhizomicrobiome composition in floating treatment wetland with Equisetum hyemale
PublicationFloating treatment wetlands (FTW) are receiving growing interest as a phyto-technology. However, there are significant research gaps regarding the actual role of plant species and plant-microbiome interactions. In this study, the nutrient uptake of Equisetum hyemale was examined in FTW microcosms under the influence of abiotic stressors: As (3 mg/L) and Pb (3 mg/L) as well as Cl− (300 and 800 mg/L) in reference to a control during...
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Uptake, accumulation, and translocation of Zn, Cu, Pb, Cd, Ni, and Cr by P. australis seedlings in an urban dredged sediment mesocosm: impact of seedling origin and initial trace metal content
PublicationThe study presents results from 6 months of phytoremediation of sediments dredged from three urban retention tanks carried out in a mesocosm setup with the use of P. australis. Two kinds of P. australis seedlings were considered: seedlings originating from natural (uncontaminated - Suncont) and anthropogenically changed environments (contaminated – Scont); this distinction was reflected in the baseline concentrations of trace metals...
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Influence of bush wear in water lubricated marine stern tube bearings with shaft misalignment
PublicationWater lubricated propeller shaft bearings are frequently employed on modern ships due to their advantages such as durability, simplicity and low price. Specific working conditions on ships cause shaft misalignment which often results in rapid wearing of bush and shaft. Shaft misalignment could be an effect of manufacturing or assembly faults but sometimes it appears due to hull or shaft deformation. The wearing process has influence...
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Fracture in Asymmetric Bonded Joints
PublicationAdhesion was studied in asymmetric bonded joints using fracture mechanics tests. The asymmetric bonded joints consist of two different type and/or thickness materials bonded by an adhesive. Mentions of asymmetric bonded joint tests employed so far are rare in the literature. They are imperfect and therefore are not standardized. Accordingly three new tests were introduced in this work to study bonded joints. The new metrological...
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Formation of Porous Structure of the Metallic Materials Used on Bone Implants
PublicationResearch on improvement of structure and fabrication methods of the bone implants are carried out for many years. Research are aimed to shape the structures, that will have a Young's modulus value similar to the value of the human bones Young's modulus. Depending on theporosity, Young's moduli can even be tailored to match the modulus of bone closer than solid metals can, thus reducing the problems associated with stress shielding...