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Search results for: artificially frozen sand
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The influence oil additives on spread cracks in silicon nitride
PublicationThe paper presents an experimental study of the influence of oil additives (Cl, S, P, cerium dioxide (CeO2)) on spread cracks in silicon nitride. The additives Cl, S, P are bound in molecules in liquid form soluble in the base oil. The CeO2 is purely in powder form in suspension. The use of CeO2 powder was made based on the good results of polishing of silicon nitride. A ceramic angular contact ball bearing was modelled using a...
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Effects of beach wrack on the fate of mercury at the land-sea interface – A preliminary study
PublicationSince the 1970s, the amount of aquatic plants and algae debris, called beach wrack (BW), has increased along the shores of industrialised regions. The strong ability of primary producers to accumulate pollutants can potentially result in their deposition on the beach along with the BW. Despite that, the fate and impact of such pollutants on sandy beach ecosystems have not been investigated so far. This study examines the fate...
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Sewage gardens - constructed wetlands for single family households
PublicationDuring the last 30 years the increase of interest in low-cost decentralized and small wastewater treatment plants (WWTP) is observed in Europe. For this purpose sand filters, stabilization ponds, mini reactors with activated sludge, trickling filters and treatment wetlands are used. Among the listed facilities treatment wetlands (TWs) offer effective and reliable treatment efficiency, being at the same time low-cost and simple...
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Phylogenetic trees of genus Oncidium Sw. based on analysis of DNA sequences
Open Research DataGenus Oncidium Sw. is widely regarded as a polyphiletic, and the taxonomic boundaries between him and such genera as Odontoglossum Kunth. or Miltonia Lindley remain blurred. The goal of the study was to determine the phylogenetic relationships within the genus Oncidium s.lato based on the DNA sequences analysis. The correlation between molecular data...
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Occurrences, sources, and transport of organochlorine pesticides in the aquatic environment of Antarctica
PublicationWe review information on the concentration levels of organochlorine pesticides in the abiotic aquatic environment (in seawater, sea ice, surface freshwater, snow, firn, and glacial ice) and the organisms inhabiting those, in Antarctica. Particular attention is given to the environmental fate of these pollutants, which modifies their impact on the organisms living in the Antarctic. OCPs have been delivered to the Antarctic environment...
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The microbial and sensory quality of mackerel hot smoked in mild conditions
PublicationThe quality indices of Atlantic mackerel, hot smoked at core temperature not exceeding 60°C, containing 14–27 g salt and 580–670 g water per kg meat, was determined just after smoking and during storage. The aerobic plate count after smoking, chilling and packing in cardboard boxes was 0–12 cfu/25 cm2of the skin of the smoked fish and 10–240 cfu/g of flesh. It was 1.9 log cycle lower than that in the frozen raw material. At 2°C,...
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Long-Term Impact of Wind Erosion on the Particle Size Distribution of Soils in the Eastern Part of the European Union
PublicationWind erosion is the leading cause of soil degradation and air pollution in many regionsof the world. As wind erosion is controlled by climatic factors, research on this phenomenon isurgently needed in soil and land management in order to better adapt to climate change. In thispaper, the impact of wind erosion on the soil surface in relation to particle size distribution wasinvestigated. Changes in percentage of sand, silt and...
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Assessment of cytotoxic and endocrine potential of selected xenobiotics commonly present in food products
PublicationMore and more increased intensity of anthropopressure processes can be observed, among other things, in the release of great quantities of synthetic substances into the environment, including the Endocrine Disrupting Compounds (EDC). A vast number of chemical substances is considered to belong to the this group, including substances which occur naturally in the environment, such as mycotoxins and phytoestrogens, and substances...
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Guided Wave Propagation in Detection of Partial Circumferential Debonding in Concrete Structures
PublicationThe following article presents results of investigating the damage detection in reinforced concrete beams with artificially introduced debonding between the rod and cover, using a non-destructive method based on elastic waves propagation. The primary aim of the research was to analyze the possible use of guided waves in partial circumferential debonding detection. Guided waves were excited and registered in reinforced concrete...
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Permeability of the small intestinal mucus for physiologically relevant studies: Impact of mucus location and ex vivo treatment
PublicationThe small intestinal mucus is a complex colloidal system that coats the intestinal mucosa. It allows passage on nutrients/pharmaceuticals from the gut lumen towards the epithelium, whilst preventing it from direct contact with luminal microorganisms. Mucus collected from intestinal tissue is often used in studies looking at inter-mucosal transport of food particulates, drug carriers, etc. However, detaching the highly hydrated...
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Can high hydrostatic pressure processing be the best way to preserve human milk?
PublicationBreastfeeding is one of the most important factors influencing proper child development. When a mother cannot breastfeed, the best alternative, especially for feeding premature infants, is to then use of human milk (HM) which has been collected, preserved and stored in Human Milk Banks (HMB). Scope and approach: In this review, the impact of some stages of the management of HM in HMB on its final biological value and microbiological...
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Wpływ mikrosfer-frakcji odpadów paleniskowych na mikrostrukturę i wybrane właściwości uzytkowe
PublicationIn this study, the microspheres samples were collected from national power station „Dolna Odra”. In this study, the following materials were used: Portland cement class 32,5R and aggregates of 2-8 and 8-16 fractions and natural sand with a maximum grain size of 2 mm and water. Concrete mixtures were made with microspheres additions of 15%, 25% and 40%. A constant water to binder ratio (w/b) of 0,52 was used throughout the investigation....
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Stationary underwater channel experiment: Acoustic measurements and characteristics in the Bornholm area for model validations
PublicationThe underwater acoustical channel is time-variant, and even on small time scales there is often existing no ‘acoustical frozen ocean’. Popular is the use of WSSUS-channel transmission modeling (Wide-Sense Stationary Uncorrelated Scattering) for the stochastic description of bandpass signals in GSM mobile phones with moving participants; since this results in a halved number of model parameters. For underwater sound applications...
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THE STUDY OF WATER POLLUTION OF THE LOWER VISTULA RIVER BY PLASTIC PARTICLES
PublicationSince the beginning of widespread use of plastic its consumption and production has been constantly increasing. As a result of human activity part of waste ends up in our environment and is deposited in each of the elements of the biosphere. These impurities can be in the form of large elements, small particles fragmented to macroscopic level (pellets, facial scrub grains) and the microparticles visible under a microscope. Particularly...
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Structural Assessment of Reinforced Concrete Beams Incorporating Waste Plastic Straws
PublicationThe behavior of reinforced concrete beams containing fibers made of waste plastic straws (WPSs) under the three point bending test is examined. The effect of WPS fiber addition on the compressive and split tensile strength is reported. Four concrete mixes were prepared. The control mix PS-0 had a proportion of 1 cement: 1 sand: 2 coarse aggregate and a water cement ratio of 0.4. In the other three mixes PS-0.5, PS-1.5 and PS-3,...
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Evaluation of the potential of Microwave Plasma–Atomic Emission Spectrometry for trace elements leaching assessment from the concrete matrix with sewage sludge ash additives
PublicationThe management of ash generated during the thermal utilization of sewage sludge is a significant environmental problem requiring an effective technological solution. One alternative way to dispose of sewage sludge is to bind it in concrete as a substitute for part of the aggregate. The properties of the C-S-H phase enable effective immobilization of harmful substances that sewage sludge contains. The amount of individual compounds...
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Shear band evolution phenomena in direct shear test modelled with DEM.
PublicationA direct shear test is widely used in the geotechnical engineering field. It is an easy and quick test to measure the shear properties of soil. This test often replaces more expensive and difficult tri-axial shear test. Despite that the direct shear test is known and used for a long time, it is still not well investigated at the grain scale. This paper deals with the micro behaviour of the cohesionless sand inside the direct shear...
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Application of H2O2 to optimize ammonium removal from domestic wastewater
PublicationThe paper presents the results of application of hydrogen peroxide (H2O2) for the optimization of the effects of ammonia nitrogen removal from domestic wastewater. The investigations were carried out at a model wastewater treatment plant consisting of a preliminary sedimentation tank and a sand filter with a horizontal flow of wastewater at a constant hydraulic load of 1.44 L/day. The efficiency of ammonia nitrogen removal was...
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Infiltration in a double-porosity medium: Experiments and comparison with a theoretical model
PublicationThis paper presents experimental verification of the mathematical model of unsaturated flow in double‐porosity soils developed by the asymptotic homogenization method. A series of one‐dimensional infiltration experiments was carried out in a column filled with a double‐porosity medium composed of a mixture of sand and sintered clayey spheres arranged in a periodic manner. The unsaturated hydraulic properties of each porous material...
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Overview of planar antenna loading metamaterials for gain performance enhancement: the two decades of progress
PublicationMetamaterials (MTMs) are artificially engineered materials with unique electromagnetic properties not occurring in natural materials. MTMs have gained considerable attention owing to their exotic electromagnetic characteristics such as negative permittivity and permeability, thereby a negative refraction index. These extraordinary properties enable many practical applications such as super-lenses, and cloaking technology, and are...
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Tyre/road noise reduction of poroelastic road surface tested in a laboratory
PublicationA so-called poroelastic road surface (PERS) is being developed in Europe. This contains a large percentage of rubber particles mixed with hard aggregate (stone and sand) and bound with polyurethane. This gives high air void content (around 30 %), high elasticity and smooth texture, all of which should give low noise properties. Inthis experiment anominally 30 mm thick sample of PERS was mounted on a steel drum. Various car tyres...
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Degradation of electrical performance of a crystalline photovoltaic module due to dust deposition in northern Poland
PublicationThe reduction in power output caused by the accumulation of dust on the photovoltaic module surface is an important problem and should receive much more attention in the literature. This study was an evaluation of the performance degradation of crystalline photovoltaic modules due to natural and simulated dust deposition. Dust is created from powdered grains of sand and particles of different bodies. Dust originates from different...
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Estimation of Conservative Contaminant Travel Time through Vadose Zone Based on Transient and Steady Flow Approaches
PublicationEstimation of contaminant travel time through the vadose zone is needed for assessing groundwater vulnerability to pollution, planning monitoring and remediation activities or predicting the effect of land use change or climate change on groundwater quality. The travel time can be obtained from numerical simulations of transient flow and transport in the unsaturated soil profile, which typically require a large amount of data and...
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Soil and groundwater fecal contamination as a result of sewage sludge land application.
PublicationThe release of sludge-born bacteria and their further transport in subsurface was studied. The migration of bacteria was investigated in column experiments which were carried out under the conditions corresponding to naturally occurring extreme rainfall. Coal fly ash as well as coarse and medium grained sand, which properties are similar to the soils present in degraded areas, were used as column beds. Sewage sludge was applied...
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WAYS TO IMPROVE THE EFFICIENCY OF WASTEWATER TREATMENT OF A CARDBOARD AND PAPER MILL
PublicationThe results of research on physical and chemical methods for the preliminary treatment of wastewater of a cardboard and paper factory in Khmelnytskyi region of Ukraine are presented. At the cardboard and paper factory, wastewater is treated at a sewage treatment plant, which includes sand traps, primary radial sedimentation tanks, aeration tanks with activated sludge regenerators, secondary radial sedimentation tanks, and bioponds....
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Assessment of the application of CEM III with exposed aggregate as an alternative to CEM I for road pavements
PublicationThe article presents a results of study on the impact of replacing CEM I SR3/NA by CEMIII/A LH/HSR/NAon the mechanical properties and durability of pavement concrete with exposed aggregate. Was used granite aggregate and washed sand. Water/cement () ratio in the tested concretes constituted 0.35 and 0.4 and part of the cement was replaced with a 5% addition of natural pozzolana – zeolite. Compressive strength tests were performed...
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Simple empirical formula to estimate the main geomechanical parameters of preplaced aggregate concrete and conventional concrete
PublicationPreplaced aggregate concrete (PAC) or two-stage concrete is a specific type of concrete successfully employed in many projects including underwater concrete structures, massive concrete structures, structures made of reinforced concrete, and improvement of concrete structures. PAC is significantly different than the conventional concrete. In this type of concrete, aggregates are initially poured into the mold, the voids between...
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Seabed Topography Changes in the Sopot Pier Zone in 2010–2018 Influenced by Tombolo Phenomenon
PublicationBathymetric surveys of the same body of water, performed at regular intervals, apart from updating the geospatial information used to create paper and electronic maps, allow for several additional analyses, including an evaluation of geomorphological changes occurring in the coastal zone. This research is particularly important in places where the shape of the coastal zone has been violently disturbed, including by human activity....
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Accuracy of Pretreatment Ultrasonography Assessment of Intra-Abdominal Spread in Epithelial Ovarian Cancer: A Prospective Study
PublicationThe aim of this study was to test the accuracy of ultrasonography performed by gynecological oncologists for the preoperative assessment of epithelial ovarian cancer (EOC) spread in the pelvis and abdominal cavity. A prospective, observational cohort study was performed at a single tertiary cancer care unit. Patients with suspected EOC were recruited and underwent comprehensive transvaginal and abdominal ultrasonography performed...
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Wave propagation signals in concrete beams under 3-point bending
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete beams with dimensions 40 x 40 x 160 cm3under the 3-point bending. The beams were made of concrete with the following ingredients: CEM I 42.5R (450 kg/m3), water (177 kg/m3), sand 0-2 (675 kg/m3) and gravel 2-8 (675 kg/m3). The bending test was performed using a Zwick/Roell Z10...
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Cadmium accumulation by Phragmites australis and Iris pseudacorus from stormwater in floating treatment wetlands microcosms: Insights into plant tolerance and utility for phytoremediation
PublicationEnvironmentally sustainable remediation is needed to protect freshwater resources which are deteriorating due to severe industrial, mining, and agricultural activities. Treatment by floating wetlands could be a sustainable solution to remediate water bodies. The study aimed to examine the effects of Cd on Phragmites australis and Iris pseudacorus growth (height, biomass, root length and chlorophyll contents), anatomy, Cd accumulation...
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Machine learning-based prediction of preplaced aggregate concrete characteristics
PublicationPreplaced-Aggregate Concrete (PAC) is a type of preplaced concrete where coarse aggregate is placed in the mold and a Portland cement-sand grout with admixtures is injected to fill the voids. Due to the complex nature of PAC, many studies were conducted to determine the effects of admixtures and the compressive and tensile strengths of PAC. Considering that a prediction tool is needed to estimate the compressive and tensile...
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Soil contamination with geohelminths in children’s play areas in Szczecin, Poland
PublicationThe presence of invasive forms of parasites in the soil represents a potential threat to public health, especially for children. The aim of the study was to determine the degree of contamination with geohelminth eggs of soil samples collected from sandpits and playgrounds in the Szczecin area. The findings showed overall prevalence of soil samples contaminated with geohelminth eggs in the soil and sand...
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Effects of full displacement pile installation on the stress and deformation state of surrounding soil: review
PublicationSeveral field and model tests have been conducted to investigate the impact of pile installation on bearing capacity. However, little is known about how piles behave during installation, how they interact with the surrounding soil, and how this affects sandy soil properties. This review paper investigates the effect of pile driving on surrounding sandy soil as it compacts sandy soil near to the pile. For this purpose, various related...
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Machine learning-based prediction of preplaced aggregate concrete characteristics
PublicationPreplaced-Aggregate Concrete (PAC) is a type of preplaced concrete where coarse aggregate is placed in the mold and a Portland cement-sand grout with admixtures is injected to fill the voids. Due to the complex nature of PAC, many studies were conducted to determine the effects of admixtures and the compressive and tensile strengths of PAC. Considering that a prediction tool is needed to estimate the compressive and tensile strengths...
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Effect of Chitosan Solution on Low-Cohesive Soil’s Shear Modulus G Determined through Resonant Column and Torsional Shearing Tests
PublicationIn this study the effect of using a biopolymer soil stabilizer on soil stiffness characteristics was investigated. Chitosan is a bio-waste material that is obtained by chemical treatment of chitin (a chemical component of fungi or crustaceans’ shells). Using chitosan solution as a soil stabilizer is based on the assumption that the biopolymer forms temporary bonds with soil particles. What is important is that these bonds are biodegradable,...
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5-Thiocyanato-2′-deoxyuridine as a possible radiosensitizer: electron-induced formation of uracil-C5-thiyl radical and its dimerization
PublicationIn this work, we have synthesized 5-thiocyanato-2′-deoxyuridine (SCNdU) along with the C6-deuterated nucleobase 5-thiocyanatouracil (6-D-SCNU) and studied their reactions with radiation-produced electrons. ESR spectra in γ-irradiated nitrogen-saturated frozen homogeneous solutions (7.5 M LiCl in H2O or D2O) of these compounds show that electron-induced S–CN bond cleavage occurs to form a thiyl radical (dU-5-S˙ or 6-D-U-5-S˙) and...
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Standard and modified falling mass impact tests on preplaced aggregatefibrous concrete and slurry infiltrated fibrous concrete
PublicationAlthough several studies have been conducted to evaluate the impact response of concrete using theAmerican Concrete Institute (ACI) 544-2R falling mass impact test, the variations in test results are themain drawback of this testing method. This study aims to reduce the variations in experimental impacttest results by introducing two simple test setup modifications; (1) using coarse or fine aggregate bed-ding as an alternative...
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Methodology for Carrying Out Measurements of the Tombolo Geomorphic Landform Using Unmanned Aerial and Surface Vehicles near Sopot Pier, Poland
PublicationThe human impact on the ecosystem has been particularly evident in the last century; it transforms the Earth’s surface on an unprecedented scale and brings about irreversible changes. One example is an oceanographic phenomenon known as a tombolo, i.e., a narrow belt connecting the mainland with an island lying near the shore formed as a result of sand and gravel being deposited by sea currents. The phenomenon contributes to an...
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STORMWATER AS AN ALTERNATIVE WATER SOURCE: QUALITY CHANGES WITH RAINFALL DURATION AND IMPLICATIONS FOR TREATMENT APPROACHES
PublicationThe pressure on the world’s water resources is rapidly increasing due to population growth and climatic changes. Valorisation of stormwater as a water resource for non-potable reuse can reduce high-quality water demands and save it for potable uses. In this context, not only roof runoff but also drained stormwater outflow, representing considerably higher pollution levels, should be considered as a potential resource. We analysed...
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Freelance technical writing application for a job which I did not get.
PublicationIn this essay I am going to explore the different ways in which developments in engineering technology and materials science have improved the quality of learning and at the same time somewhat diminished students innate intellectual ability which came as the result of what we know as A.I. According to wikipedia.org the word "education" comes from the conjunction of a Latin words "I lead" or "duco" meaning "I...
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Converting beach wrack into a resource as a challenge for the Baltic Sea (an overview)
PublicationThe paper distinguishes beach wrack, the marine generated organic part of beach cast, as a separate management object and discusses research questions related to its management and economically viable use. Based on experiences from the Baltic Sea and existing practices from countries with different management systems clear distinction between the management of natural and anthropogenic components of cast material is seen as an...
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AeroSense Measurements: Wind Tunnel Ecole Centrale Lyon
Open Research DataData from wind tunnel tests of Aerosesne measurement system installed on NACA 63418 aerfoil in the anechoic wind tunnel at the Ecole Centrale Lyon.