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The structural and physical properties of the new titanium- and niobium-rich type-A high-entropy alloy (HEA) superconductor Nb 0.34 Ti 0.33 Zr 0.14 Ta 0.11 Hf 0.08 (in at.%) were studied by X-ray powder diffraction, energy dispersive X-ray spectroscopy, magnetization, electrical resistivity, and specific heat measurements. In addition, electronic structure calculations were performed using two complementary methods: the Korringa–Kohn–Rostoker Coherent Potential Approximation (KKR-CPA) and the Projector Augmented Wave (PAW) within Density Functional Theory (DFT). The results obtained indicate that the alloy exhibits type II superconductivity with a critical temperature close to 7.5 K, an intermediate electron–phonon coupling, and an upper critical field of 12.2(1) T. This finding indicates that Nb 0.34 Ti 0.33 Zr 0.14 Ta 0.11 Hf 0.08 has one of the highest upper critical fields among all known HEA superconductors. [ABSTRACT FROM AUTHOR]

The developed model of arsenic volatilization model based on the ash fusion temperature, coal type, and combustion temperature during coal combustion allows describing the complex mechanisms that occur during combustion. This Special Issue contains successful submissions as an answer to the invitation to bring together research on advances in design, modeling, and performance of novel combustion techniques for clean energy. Several AI techniques and algorithms were presented and incorporated to formulate the step-wise methodology in the spirit of industry 4.0-data analytics [[11]]. [Extracted from the article]

In the present work surface roughness of copper samples after mechanical surface preparation processes (polishing, grinding, sand-blasting) and after exposure in non-oxidizing (high purity argon) and oxidizing (air) conditions at 700 and 750 °C have been evaluated by contact profilometer and by fractal analysis. Quantitative description of surfaces that are hidden from the sight of conventional methods is possible by fractal analysis, e.g. in the present work, the roughness of Cu 2 O/Cu boundary has been evaluated under oxide layer. It has been pointed out, that in both oxidizing and non-oxidizing conditions initial surface roughness of copper is affected by annealing at high temperature: at 700 °C surface roughness of polished and ground samples increased but at 750 °C decreased in comparison to surface roughness prior to heat treatment. For sand-blasted samples in both oxidizing and non-oxidizing conditions the lowest values of surface roughness parameters were obtained at 750 °C. It is then concluded that two phenomena are responsible for such effect: chemical reaction between copper and oxygen and surface diffusion of copper due to high temperature of annealing. Unlabelled Image • Surface of copper samples had been polished, ground and sand-blasted. • Surface roughness had been evaluated by contact profilometer and fractal analysis. • There are differences in roughness after annealing in oxidizing and non-oxidizing conditions at different temperatures. • Changes in roughness are caused by chemical reaction between Cu and O and surface diffusion of Cu at high temperature. [ABSTRACT FROM AUTHOR]

The experimental concentration profile in Ti-NiAl diffusion couple after diffusion at 1173 K for 100 h. Determination of diffusion coefficients in a ternary multiphase system is discussed as the data on the approximation method allowing to determine the diffusion coefficients in such systems are currently missing in the literature. In the present work, the mass conservation approach (MCA) for calculation the diffusivities in individual phases with the linear differences in composition is proposed. The diffusion data can be determined exclusively based on the experimental results. The method is implemented and validated for the ternary Ti-NiAl system, in which three intermetallic phases are stable. [ABSTRACT FROM AUTHOR]

Fe-based alloys are commonly used in almost every sector of human life. For different reasons, the surfaces of the real parts are prepared using different methods, e.g., mirror-like polishing, grit-blasting, etc. The purpose of the present work is to answer the question how the surface preparation influences the oxidation behavior of Fe-based alloys. To answer this question, a high-purity model alloy, Fe–5 wt%Al, was isothermally oxidized in a thermogravimetrical furnace. The post-exposure analysis included SEM/EDS (WDS) and XRD. The surface roughness was determined by a contact and laser profilometer. The obtained results demonstrate that the mechanical surface preparation influences oxidation kinetics as well as the microstructure of the oxide scale formed on the alloy at both studied temperatures. Namely, polishing and grinding caused local formation of Fe-rich nodules and sub-layer of protective Al2O3. In contrast, grit-blasting leads to the formation of a thick outer Fe-oxide and internal aluminum nitridation. A significant increase in the oxidation rate of the material after grit-blasting was attributed to grain refinement in the near-surface region, resulting in an increase in easy diffusion paths, namely grain boundaries. [ABSTRACT FROM AUTHOR]

Highlights • Surface roughness had been evaluated by contact profilometer and fractal analysis. • Influence of surface preparation on oxidation kinetic for pure Ni, Cu and Ni-Cu alloy. • Sand-blasting process improves surface roughness and contaminates surface with Al 2 O 3. • Surface preparation process promotes different diffusion mechanisms for pure Cu. Abstract In the present paper, the analysis of polishing, grinding and sand-blasting processes on oxidation behavior of nickel, copper and Ni30Cu70 alloy has been performed for three different temperatures. Surface roughness has been analyzed using two methods: contact profilometer and fractal analysis. It has been proved that R a parameter for sand-blasted samples is greater about one order of magnitude from ground and two order of magnitude from polished samples. Obtained mass gain plots after isothermal oxidation tests, SEM microphotographs and SEM/EDS analysis of the samples prove that morphology of the polished and ground samples does not vary significantly after oxidation at investigated temperatures, but differences in oxide layer thicknesses and mass gains were observed. Oxidized sand-blasted samples revealed that increased surface roughness and alumina intrusions remained in the surface after sand-blasting process change the oxidation process–mixed Al/(Ni, Cu or Ni-Cu) oxide is formed and separate Al 2 O 3 particles are visible. Moreover, differences in thickness ratio of copper oxides: Cu 2 O to CuO on copper samples oxidized at 750 °C (26, 20; 29, 64; 43, 45 for polished, ground and sand-blasted samples, respectively) prove that surface preparation influence high-temperature oxidation of the samples by promoting new diffusion mechanism. [ABSTRACT FROM AUTHOR]

In this paper the Diffusion Path (DP) method is presented. The method allows for the determination of the diffusion path during a reactive diffusion process. The initial conditions of the method are the phase diagram, diffusion coefficients in the phases and initial composition of the diffusion couple. The method allows for the determination of the diffusion path—the intermetallic phases generated during the diffusion process and the order of their generation. The results of the DP method are compared with the experimental results obtained for the Ti-NiCu diffusion couples with various Ni to Cu content ratio. [ABSTRACT FROM AUTHOR]

Due to a growing number of environmental issues, including global warming, water scarcity, and fossil fuel depletion, the topic of modern materials in energy is becoming crucial for our civilization. The technological advancements that have been observed bring many innovations that significantly impact how energy can be generated, stored, and distributed. Moreover, new opportunities have emerged in energy and materials engineering due to the increasing computational capability of current data processing systems. Methods that are highly demanding, time-consuming, and difficult to apply may now be considered when developing complete and sophisticated models in many areas of science and technology. Combining computational methods and AI algorithms allows for multi-threaded analyses solving advanced and interdisciplinary problems. Therefore, knowledge and experience in this subject, as well as the investigation of new, more efficient, and environmentally friendly solutions, currently represent one of the main directions of scientific research. The Special Issue "Advances in Materials: Modelling Challenges and Technological Progress for Green Engineering and Sustainable Development" aims to bring together research on material advances, focusing on modelling challenges and technological progress (mainly for green engineering and sustainable development). Original research studies, review articles, and short communications are welcome, especially those focusing on (but not limited to) artificial intelligence, other computational methods, and state-of-the-art technological concepts related to the listed keywords within energy and materials engineering. [ABSTRACT FROM AUTHOR]

Due to the fact that the landfill deposition of municipal waste with the higher heating value (HHV) than 6 MJ/kg in Poland is prohibited, the application of waste derived fuels for energy production seems to be good option. There is a new combined-heat-and-power (CHP) plant in Zabrze, where varied solid fuels can be combusted. The formation of ashes originating from the combustion of alternative fuels causes a need to find ways for their practical application and demands the knowledge about their properties. Therefore, the present work is devoted to studying the co-combustion of solid recovered fuel (SRF) and coal, its impact on fly ash quality and the potential application of ashes to synthesis zeolites. The major objectives of this paper is to present the detail characteristics of ash generated during this process by using the advanced instrumental techniques (XRF, XRD, SEM, B ET, TGA). The co-combustion were carried out at 0.1 MWth fluidized bed combustor. The amount of SRF in fuel mixture was 1, 5, 10 and 20%, respectively. The focus is on the comparison the ashes depending on the fuel mixture composition. Generally, the ashes characterise high amounts of SiO2, Al2O3 and Fe2O3. It is well observed, that the chemical composition of ashes from co-combustion of blends reflects the amount of SRF addition. Considering the chemical composition of studied ashes, they can be utilize as a zeolites A. The main conclusions is that SRF can be successfully combusted with coal in CFB technology and the fly ashes obtained from coal + SRF fuel mixtures can be used to synthesis zeolites. [ABSTRACT FROM AUTHOR]

The effect of bed particle size on the local heat transfer coefficient between a fluidized bed and vertical rifled tubes (38 mm-O.D.) has been determined in a large-scale circulating fluidized bed (CFB) reactor. Bed particles with different Sauter mean particle diameter within the range of 0.219–0.411 mm and particle density in the range of 2650–2750 kg/m 3 were used as bed material in this heat transfer study. A gas fluidized bed furnace with 27.6 × 10.6 m cross-section above refractory line and 48 m in height was used. Air coal firing conditions at the membrane wall in the form of water tubes welded with lateral fins corresponded to a suspension density covering the range of 1.36–6.22 kg/m 3 , furnace temperatures in the range of 1080–1164 K, a superficial gas velocity varied from 2.99 to 5.11 m/s and solids circulation flux covered a range of 23.3–26.2 kg/(m 2 s). For these operating conditions, the heat transfer analysis of CFB reactor with detailed analysis of bed-to-wall heat transfer coefficient along furnace height was investigated. In this work, the overall heat transfer coefficient was estimated using a mechanistic heat transfer model based on cluster renewal approach. The experimental results show that: (i) higher heat transfer coefficients along furnace height were found under finer bed particles size d p < 0.241 mm, (ii) heat transfer data confirms strong dependency of the overall heat transfer coefficient on suspension density and also hydrodynamic conditions within CFB furnace, (iii) for small bed particles, d p < 0.233 mm, the particle convection component plays dominant role in heat transfer mechanism, (iv) for large bed particles, d p > 0.366 mm, the effect of particle size on relative contribution of radiation from dispersed phase become essential with particle diameter increasing, and (v) for all bed particles with diameters in the range of 0.240–0.411 mm, the gas convection heat transfer coefficient between the fluidized bed (Geldart B particles) and the rifled tubes increased as the bed particles size increased. [ABSTRACT FROM AUTHOR]

Adsorption is considered as one of the most promising technologies for CCS. Gas adsorption involves the separation of gaseous components from flue gas using solid adsorbents. The gaseous component, adsorbate, is adsorbed from the gas phase on a solid material. Regarding CO2 adsorption, it is important to consider the parameters, that is the high sorption capacity, CO2 selectivity, regeneration and stability in multiple cycles. New directions for the development of adsorbents are focused on increasing their capacity ' for this purpose, amine impregnation is carried out. This paper presents a new approach to obtaining mesoporous material from fly ash and, based on this, a new physico-chemical adsorbent obtained by impregnation. The effectiveness of the process was confirmed by thermogravimetric analysis and FTIR infrared spectroscopy. [ABSTRACT FROM AUTHOR]

The present work introduces a way of predicting the local heat transfer coefficient in the combustion chamber of a circulating fluidized bed combustor (CFBC) by the fuzzy logic (FL) approach. Fuzzy logic techniques have been successfully applied to calculate the overall heat transfer coefficient for membrane-walls in the combustion chamber of the 670 t/h CFB boiler. The previously obtained heat transfer coefficients values have been used to build up a simple FL model. It has been shown, that the presented fuzzy logic approach give quick and accurate results as an answer to the input data set. The local heat transfer coefficients evaluated using the developed model have been in a good agreement with the desired data. [ABSTRACT FROM AUTHOR]

In this paper, heat transfer experiments were conducted in order to evaluate the contributions of particle convection, gas convection, cluster convection and also radiation from cluster and dispersed phases to the overall heat transfer coefficient in a furnace chamber of a large-scale supercritical CFB reactor. Heat transfer behavior in a circulating fluidized bed between the water membrane wall and bed inventory has been analyzed for Geldart B particles. Bed inventory used in the tests had particle density in the range of 2650–2750 kg/m 3 . The experimental CFB facility has the dimension of 27.6 × 5.3 m in bed rectangular cross-section and 48 m in height of the furnace. The performance tests have been carried out at three different sizes of the bed material with Sauter mean particle diameters of 0.246, 0.272 and 0.444 mm. Above heat transfer studies have been conducted for the operating parameters covering the range of 1082–1183 K for bed temperature, 2.92–5.25 m/s for superficial velocity, 6.86–8.25 kPa for pressure drop, 23–25.6 kg/(m s 2 ) for the circulation rate of solids and 0.4–0.44 for the bed voidage at minimum fluidization velocity. In order to predict the overall heat transfer coefficient, a cluster renewal approach was used. The bed-to-wall heat transfer coefficients obtained in these operating ranges were about 78–226 W/(m 2 K). The contributions of convective and radiative heat transfer to the overall heat transfer coefficient were estimated. The variation in contributions depended on solid suspension density and bed temperature. The average contribution of convective and radiative heat transfer components varied between 13.5–54% and 46–86.5%, respectively. [ABSTRACT FROM AUTHOR]

The role of bed particle size in the heat transfer to membrane walls of a supercritical circulating fluidized bed (CFB) combustion system was studied. In this work, values of the heat transfer coefficient between the membrane walls and the bed include contributions of particle convection, gas convection, cluster convection, gas conduction and also radiation. The heat transfer conditions in the CFB combustor were analyzed for five sizes of bed inventory, with Sauter mean particle diameters of 0.219, 0.232, 0.246, 0.365 and 0.411 mm (Geldart group B). The operating parameters of a circulating fluidized bed combustor covered a range of 3.13–5.11 m s −1 for superficial gas velocity, 22.3–26.2 kg m −2 s −1 for the circulation rate of solids, 0.11–0.33 for the secondary to primary air ratio and 7.16–8.44 kPa pressure drop. Furthermore, the bed temperature, suspension density and the main parameters of cluster renewal approach were treated as experimental variables along the furnace height. To estimate the local bed to wall heat transfer coefficient, some experimental data from CFB boiler and some simple correlations were used. A simple semi-empirical method was proposed to estimate the overall heat transfer coefficient inside the furnace as a function of particle size and suspension density with an accuracy of 21%. Computationally obtained results were compared with the experimental data for CFB unit in a large-scale. It was observed that both bed particle sizes as well as the suspension density significantly influence heat transfer conditions. [ABSTRACT FROM AUTHOR]

Thermochemical technologies of cooling capacity production are ecologically effective processes of utilizing a heat stream combined with electricity production. Apart from poly-generation systems, their applications are found in air conditioning systems cooperating with solar installations and other industrial installations generating heat as a by-product. Unlike the widely commercialized absorption chillers, continuous research on improving the heat utilization efficiency in adsorption systems gives innovative nature to this technology. This paper presents a work analysis of the adsorption cooling device. The construction, working principle, and variability of defined performance parameters in time for a representative cooling cycle were also presented. [ABSTRACT FROM AUTHOR]

Abstract: The present work introduces a way of predicting the local heat transfer coefficient in the combustion chamber of the circulating fluidized bed boiler (CFB) by the artificial neural network (ANN) approach. Neural networks have been successfully applied to calculate the local overall heat transfer coefficient for membrane walls, Superheater I (SH I, Omega Superheater) and Superheater II (SH II, Wing-Walls) in the combustion chamber of the 260MWe CFB boiler. The previously verified numerical model has been used to obtain the overall heat transfer coefficients, necessary for training and testing the ANN. It has been shown, that the neural networks give quick and accurate results as an answer to the input pattern. The local heat transfer coefficients evaluated using the developed ANN model have been in a good agreement with numerical and experimental results. [Copyright &y& Elsevier]

Abstract: The synthesis of mesoporous molecular sieves from fly ashes is an interesting direction of use of the values of fly ash, and specifically its chemical composition (Si, Al), for obtaining high-quality porous materials offering wide possibilities of utilization. An attempt was made in the present work to obtain the MCM-41 mesoporous materials from 10 different fly ashes originating from Polish Power Stations. The synthesis was carried out by the hydrothermal method using the supernatants of coal fly ashes (fused fly ash solutions) and cationic cetyltrimethylammonium bromide (CTAB) surfactants as the structure-directing agents. Fly ashes were chemically analyzed and used to prepare mesoporous materials (MCM-41). The current work uses powder X-ray diffraction (XRD), TG/DTG, FTIR, SEM, TEM, nitrogen adsorption and 27Al MAS NMR, 29Si MAS NMR techniques to characterize physico-chemical properties of fly ash-based MCM-41 materials. The properties of the synthesized mesoporous materials were compared with those prepared from pure silica sources. Studies have shown that extracts suitable for the synthesis of the MCM-41 mesoporous material cannot be obtained from all fly ash types (even those with a very high Si content and a very high Si/Al ratio). [Copyright &y& Elsevier]

The interdiffusion in Ti-Ni70Cu30 diffusion couple was studied at 850 °C at times varied between 10 and 300 min. The diffusion paths for the samples were determined and the order of intermetallic phases occurring in the diffusion zone was established. It was concluded that after 10 and 30 min of diffusion annealing, four intermetallic phases formed, namely: Ti 2 Ni, TiNi, τ 1 and TiNi 3. Between 30 and 60 min, also the Ti 2 Cu phase appeared next to Ti 2 Ni phase forming the multi-zone region, which thickness almost doubled between 60 and 300 min of diffusion annealing at 850 °C. The formation of Ti 2 Cu and the multi-zone region was explained by the enrichment of Cu at the Ti 2 Ni/Ti boundary and connected with the increase in its diffusion flux. • Ti-Ni70Cu30 couple was annealed at 850 °C at times between 10 and 300 min. • after 10 and 30 min of annealing of Ti-Ni70Cu30 at 850 °C four phases formed. • between 30 and 60 min, the Ti 2 Cu appeared next to Ti 2 Ni forming two-phase region. • enrichment in Cu at the Ti 2 Ni/Ti boundary caused the formation of two-phase region. [ABSTRACT FROM AUTHOR]

In this paper the results of experimental studies of particle velocity fields in a circulating fluidized bed are presented. Measurements of particle velocity were carried out by means of a novel laser sheet technique, in which the laser beam was modulated with the help of an electronic modulator. Thanks to that, it was possible to register multiexposure pictures, called speckle-grams, which record single particle trajectories in selected areas of the flow. On the basis of this, three components of particle velocity vector can be estimated. [ABSTRACT FROM AUTHOR]

An analysis of the effect of thermal and flow conditions in the combustion chamber of the circulating fluidized-bed (CFB) boiler on the gaseous pollutant emission was undertaken in the study. The tests were carried out on a 670 MW boiler operating in the power engineering industry. On the basis of the obtained test results it was found that the optimization of primary and secondary air distribution, as well as fuel distribution, allowed the following pollutant reductions: CO by 52%, SO2 by 40% and NO by 6% in relation to the standard operation conditions of the boiler under investigation. The test results demonstrated that increasing the number of repetitions of bed material particle circulation between the combustion chamber and the recycling system resulted in an equalization of temperature distribution along the combustion chamber height and elongated the time of residence of sorbent particles in the CFB system. Ultimately, the test results showed the following pollutant reductions: CO by 71%, SO2 by 41%, and NOx by 19% with the number of particle circulation repetitions increased from 28 to 60 for the boiler analyzed. [ABSTRACT FROM AUTHOR]

Examines the influence of platelet-derived growth factor in the regulation of adrenomedullin receptor. Role of the receptor activity modifying protein-3; Effects on rat mesangial cells; Modulation of the responsiveness of the mesangial cell to adrenomedullin.

An electron backscattered diffraction (EBSD) method provides information about the crystallographic structure of materials. However, a surface subjected to analysis needs to be well-prepared. This usually requires following a time-consuming procedure of mechanical polishing. The alternative methods of surface preparation for EBSD are performed via electropolishing or focus ion beam (FIB). In the present study, plasma etching using a glow discharge optical emission spectrometer (GD-OES) was applied for surface preparation for EBSD analysis. The obtained results revealed that plasma etching through GD-OES can be successfully used for surface preparation for EBSD analysis. However, it was also found that the plasma etching is sensitive for the alloy microstructure, i.e., the presence of intermetallic phases and precipitates such as carbides possess a different sputtering rate, resulting in non-uniform plasma etching. Preparation of the cross-section of oxidized CM247 revealed a similar problem with non-uniformity of plasma etching. The carbides and oxide scale possess a lower sputtering rate than the metallic matrix, which caused formation of relief. Based on obtained results, possible resolutions to suppress the effect of different sputtering rates are proposed. [ABSTRACT FROM AUTHOR]

Protection against fire and the corrosion of metals is necessary to ensure human safety. Most of the fire and corrosion inhibitors do not meet the ecological requirements. Therefore, effective and ecological methods of protecting metals are currently a challenge for researchers. In this work, the influence of hexakis(4-(hydroxymethyl)phenoxy)cyclotriphosphazene (HHPCP) on the characteristics of powder coatings was examined. The coatings' properties were investigated by measuring the roughness, hardness, adhesion to the steel surface, cupping, gloss, scratch resistance, and water contact angle. The thermal stability was studied by furnace test and TGA analysis. The corrosion resistance test was carried out in a 3.5% NaCl solution. The distribution of phosphazene-derived segments in the coating was examined by GD-EOS analysis. Modified coatings show better corrosion and thermal resistance and can be used for the protection of the steel surface. Their better corrosion resistance is due to the electroactive properties of the phosphazene ring and its higher concentration at the coating surface, confirmed by GD-EOS analysis. The increase in thermal resistance is due to the effect of the formation of phosphoric metaphosphoric and polyphosphoric acids during the decomposition of HHCPC, which remain in the condensed char phase and play a crucial role in surface protection. [ABSTRACT FROM AUTHOR]

Background: Aortic valve-sparing aortic root replacement (VSARR) David procedure has not been routinely performed via minimally invasive access due to its complexity. Methods: We compared our results for mini-VSARR to sternotomy-VSARR from another excellence center. Results: Eighty-four patients, 62 in the sternotomy-VSARR group and 22 in the mini-VSARR group, were included. A baseline, the aneurysm dimensions were higher in the mini-VSARR group. Propensity matching resulted in 17 pairs with comparable characteristics. Aortic cross-clamp and cardiopulmonary bypass times were significantly longer in the mini-VSARR group, by 60 and 20 min, respectively (p < 0.001). In-hospital outcomes were comparable between the groups. Drainage volumes were numerically lower, and hospital length of stay was, on average, 3 days shorter (p < 0.001) in the mini-VSARR group. At a median follow-up of 5.5 years, there was no difference in mortality (p = 0.230). Survival at 1, 5 and 10 years was 100%, 100%, and 95% and 95%, 87% and 84% in the mini-VSARR and sternotomy-VSARR groups, respectively. No repeat interventions on the aortic valve were documented. Echocardiographic follow-up was complete in 91% with excellent durability of repair regardless of the approach: no cases of moderate/severe aortic regurgitation were reported in the mini-VSARR group. Conclusions: The favorable outcomes, reduced drainage, and shorter hospital stays associated with the mini-sternotomy approach underscore its potential advantages expanding beyond cosmetic outcome. [ABSTRACT FROM AUTHOR]

Adsorption cooling and desalination systems have a distinct advantage over other systems that use low‐grade waste heat near ambient temperature. Since improving their performance, including reliability and failure prediction, is challenging, developing an efficient diagnostic system is of great practical significance. The paper introduces artificial intelligence (AI) and an automated machine learning approach (AutoML) in a real‐life application for a computational diagnostic system of existing adsorption cooling and desalination facilities. A total of 1769 simulated data points containing data indicating a failure status are applied to develop a comprehensive AI‐based Diagnostic (AID) system covering a wide range of 42 input parameters. The paper introduces a conditional monitoring system for adsorption cooling and desalination systems. The novelty of the presented study mainly consists of two aspects. First, the intelligent system predicts the health or failure states of various components in a complex three‐bed adsorption chiller installation using the extensive input data sets of 42 different operating parameters. The developed AID expert tool, based on selecting the best from 42 models generated by the DataRobot platform, was validated on the complex, existing three‐bed adsorption chiller. The AID system correctly identified healthy and failure states in various installation components. The developed expert system is very efficient (AUC = 0.988, RMSE = 0.20, LogLoss = 0.14) in predicting emergency states. The proposed method constitutes a quick and easy technique for failure prediction and represents a complementary tool compared to the other condition monitoring methods. [ABSTRACT FROM AUTHOR]

The influence of surface roughness on its high temperature oxidation for an Ni-base superalloy was studied using laser profilometry, atomic force microscopy, mass change measurements, glow-discharge optical emission spectrometry, scanning electron microscopy, X-ray diffraction, and positron annihilation methods. The isothermal and cyclic air oxidation tests were performed at 1000 °C and showed dependence of oxidation behavior on surface roughness. Smoother surfaces oxidation resulted in the formation of a multilayered oxide scale consisting of NiO, Cr2O3, and internally oxidized Al2O3 while a rougher surface formed protective Al2O3 scale. The factors responsible for different oxidation behaviors were determined as higher concentration of vacancies and increased residual stresses in the near-surface region of studied alloys. [ABSTRACT FROM AUTHOR]

In this work, the influence of three different surface preparation processes, namely polishing, grinding and sand-blasting on oxidation process of high purity Ni48Fe52 alloy (in at. %) at high temperature has been investigated. Surface roughness of differently treated samples was measured by contact profilometer. Isothermal oxidation was performed in thermogravimetric furnace at 900°, 950° and 1000 °C for 24 h in air. Cross-sections were prepared and then observed and analyzed by SEM (Scanning Electron Microscope) /EDS (Energy Dispersive Spectroscopy). It was determined that sand-blasting increases the number of dislocations and grain boundaries in the near-surface region and therefore slows down oxidation process by faster formation of mixed nickel/iron oxide that constitutes a barrier for outward iron diffusion. Internally oxidized zone is also more uniform and thicker for polished and ground samples in comparison to sand-blasted ones as a result of recrystallization of the latter and longer duration of faster oxygen solubility in the polished and ground samples. Unlabelled Image • Surface of Ni48Fe52 alloy samples were polished, ground and sand-blasted. • Surface roughness was measured by contact profilometer. • Internal FeO precipitates are fine for polished and ground samples. • Internal FeO precipitates along grain boundaries are coarse for sand-blasted samples. • Sand-blasting prior to oxidation slows down the oxidation process. [ABSTRACT FROM AUTHOR]

In the present work the durability of the APS-TBC systems with bi-layer bond coat consisting of HTLA-CVD aluminide as bottom layer and APS-flashcoat of MCrAlY as upper layer was investigated. The additional factors potentially influencing TBC lifetime, namely substrate surface roughness prior to aluminizing and bond coat heat-treatment, were taken into account. The obtained results showed that the substrate surface roughness influences the IDZ morphology, however, IDZ disappears partly after heat-treatment and completely after high temperature exposure until the end of TBC life. The results of the lifetime measurement showed that the heat-treated TBC systems revealed up to three times longer lifetime (250 and 350 hot hours for systems with ground and grit-blasted substrate surface respectively) in comparison with non heat-treated ones (100 and 110 hot hours for systems with ground and grit-blasted substrate surface respectively). Moreover, TBC system with grit-blasted substrate revealed longer lifetime (350 hot hours) than system with ground substrate surface (250 hot hours). It was found that in both cases, the lifetime was limited by the Al-reservoir in the CVD layer and APS-flashcoat. The TBC failure was caused by the breakaway oxidation of depleted MCrAlY flashcoat particles that have led to the formation and propagation of cracks during cyclic exposure. Based on the results obtained in the present work, further elongation of the TBC lifetime is proposed by increasing of thickness of CVD aluminide layer. • Oxidation resistance of innovative APS-TBC systems with CVD aluminide and APS MCrAlY flashcoat • The effect of bondcoat heat-treatment on TBC life • The factors responsible for TBC life [ABSTRACT FROM AUTHOR]

The wear resistance of hard anodic coatings fabricated on 5005 and 6061 aluminum alloys was determined. The Taber abrasion test, ball-on-disc tribological test, and scratch test at constant load were conducted. The wear resistance of the hard coating fabricated on the 6061 alloy was found to be higher compared to the coating on the 5005 alloy. This is related to the lower nanoscale porosity of the former, and the higher hardness of the 6061 alloy compared to 5005. The specific wear rates for the load of 4.905 N were equal to 1.70 × 10−5 and 1.02 × 10−5 mm3 N−1 m−1 for the coatings on 5005 alloy and 6061 alloy, respectively. In the case of the hard anodized 5005 alloy, the specific wear rate increased with increasing load to 4.56 × 10−5 mm3 N−1 m−1 whereas for anodized 6061 alloy to 1.98 × 10−5 mm3 N−1 m−1. It was also found that the protective properties of the coating on 6061 alloy do not change significantly across the coating thickness. [ABSTRACT FROM AUTHOR]

Broadly defined climate protection is a powerful incentive in the search for environmentally friendly refrigeration technologies. Adsorption chillers are considered to be one such technology; however, their main disadvantages include a low cooling capacity, a low energy efficiency ratio (EER), and cyclic operation. Thus, a great deal of effort is being put into improving adsorption-chiller performance. In this paper, the influence of the spray angle, the number of nozzles, and the water flow rate through the nozzles on adsorption-chiller performance was investigated. Adsorption-chiller performance was investigated mainly in terms of the cooling capacity (CC), the energy efficiency ratio (EER), and the specific cooling power (SCP). The results indicated that the chiller's cooling capacity increased from about 210 W to 316 W and that the EER increased from 0.110 to 0.167 when the spray angle of the nozzles was increased from 90° to 120°. It was also reported that increasing the flow rate of water through the nozzles did not improve the average cooling capacity or the other performance parameters but resulted in more stable operation of the chiller. Additionally, using six nozzles instead of three improved the average cooling capacity and EER tenfold. [ABSTRACT FROM AUTHOR]

Sustainable development policy focuses on reducing the carbon footprint generated by the global industry and energy sector. Replacing conventional energy sources with environmentally friendly ones requires advanced research to increase energy efficiency and reduce the instability and intermittence of renewable sources. Moreover, adsorption chillers are an opportunity to introduce net-zero emission technologies to the refrigeration, air-conditioning, and desalination industries. Adsorption devices could be popularized if a method of effective heat transfer in the volume of the adsorption bed is developed. The innovative concept of introducing fluidized beds into the adsorption system can achieve the most promising results in improving energy efficiency. To confirm the adopted assumption, heat transfer coefficient calculations for the packed and fluidized bed were carried out in this paper based on experimental tests and literature data. The empirical research aims to extend the fundamental knowledge in the implementation of fluidization under low-pressure conditions, characteristic of the adsorption systems' working cycle. Experiments were conducted on a unique test stand equipped with the Intensified Heat Transfer Adsorption Bed (IHTAB) reactor prototype. Five adsorption bed samples were analyzed. The reference sample consisted only of silica gel, and the subsequent ones contained aluminum or carbon nanotubes with 5 and 10% additions. In the case of samples with admixtures, the fluidized state increased the heat transfer coefficient on average from approx. 36.9 W/m2 K to approx. 245.4 W/m2 K. [ABSTRACT FROM AUTHOR]

Adsorption refrigerators are a compelling ecological alternative to compressor refrigerators; global warming forces us to constantly look for alternative sources of energy and cold. Cold production in adsorption chillers is based on the use of heat generated by other processes running in the company. Waste heat from production processes, which has, until now, been irretrievably lost, is a potential source of energy for generating cold via an adsorption unit producing chilled water. Cooling optimizes the use of the heating network in summer and can lead to increased electricity production while reducing heat supply losses. Thus far, attempts to implement adsorption refrigerators for widespread use have not been successful as a result of the low efficiency of these devices; this is directly related to the poor heat and mass transfer conditions in the beds and heat exchangers of adsorption refrigerators. The solutions used so far, such as new working pairs, glued beds or modifications to the structure or cycle length, are still not strong enough for these devices. Therefore, it is necessary to look for new solutions. Using micro- and nanobubbles as media to increase mass and heat transfer in refrigerators is an innovative and pioneering solution. Thus, this document describes the most important features of micro- and nanobubble technology applications in adsorption refrigerators. This article is an introduction and a basis for the implementation of further research, consolidating the existing literature as a review. [ABSTRACT FROM AUTHOR]

Adsorption technology utilizes low-temperature renewable and waste heat sources for cost-effective and environmentally friendly cooling and water desalination systems. However, the problem with existing adsorption refrigerators is the low COP. This is caused by poor heat and mass transfer in existing packed bed designs. The solution to this problem lies in the use of fluidized bed technology, which enhances heat and mass transfer mechanisms. Various approaches to the construction and operation of adsorption systems with a fluidized bed of adsorbent can be found in the literature; hence, the aim of the work is to analyze the existing applications of a fluidized bed in adsorption refrigerators and other systems utilizing sorption beds. There are many methods for improving the energy efficiency of adsorption refrigerators. However, the literature suggests that fluidized bed systems have the potential to significantly improve the energy efficiency of adsorption cooling and desalination systems. Based on the review, it was concluded that using fluidization technology in adsorption cooling and desalination systems can be beneficial and represents significant potential for future research. [ABSTRACT FROM AUTHOR]

In this paper, the morphology evolution in a Bi–Sb system under the centrifugal force at room temperature is discussed. The rotation speed was 35,000 rotations per minute and the length of the arm (radii) was 88 mm. It is shown, that after the centrifugation the phases become oriented in the direction parallel to the direction of the centrifugal force. Moreover, the voids move in the direction opposite to the centrifugal force direction. The movements of such voids result in their coalescence and finally lead to formation of cracks at the interface between ordered and disordered part of the sample. [ABSTRACT FROM AUTHOR]

To meet the growing energy demand and thereby increase power-generating capacity, the dependency on coal for power generation, are required a more environmentally friendly methods of fly ash utilization. Therefore, the priority is to characterize domestic fly ash in detail in order to ascertain its potential uses as raw material in the production of high-value products. The high silica content of fly ash makes it a potential useful source for the synthesis of nanoporous materials, such as zeolites and mesoporous molecular sieves. The physicochemical properties of fly ash coming from seven coal-fired power plants and three heat and power plants in Poland are presented in this work. The fly ash was sampled from power plants that use combustion of lignite and hard coal in pulverized-fuel boilers (PC) and circulating fluidized bed (CFB) boilers. The fly ash was examined for its morphology, chemical and mineral composition, grain size, structure and thermal stability by using advanced instrumental techniques (XRF, XRD, SEM, BET, TGA). According to mineralogical and chemical composition of fly ash, three fly ash samples are potentially useful as a raw material for making zeolite A, two samples for zeolite X and fly ash No. 8 for zeolite Y. The samples with the highest content of SiO2 and Al2O3 (Nos. 2-6 and 9) can be used to synthesize mesoporous molecular sieves such as MCM-41 and SBA-15. Received zeolites and mesoporous sieves from these fly ash samples will be used for removing NO2 from exhaust gas, and these studies can be implemented in power plants with CO2 capture, in the process of exhaust gas purification to removal of NO2. [ABSTRACT FROM AUTHOR]

Adsorption systems are alternatives to compressor cooling systems. Apart from many advantages, these systems are characterized by low COP and SCP parameters. One of the most promising options to improve the performance of adsorption chillers is the replacement of the stationary bed with a fluidized one. A fluidized bed significantly increases the heat and mass transfer within the bed, enables better contact between gas and solid phases, and results in the proper mixing of adsorbent particles. This paper presents the possibility of using fluidized beds in adsorption chillers. This paper shows the results of CFD numerical modelling of the operation of a fluidized bed for an adsorption chiller and simulations of the bed temperature profiles during the adsorption and desorption processes of sorbent in a fluidized bed. This article presents an analysis of CFD simulation results for the optimal angle of heat exchangers. [ABSTRACT FROM AUTHOR]

Abstract Aluminium finishing industry requires a stripping solution for anodic coatings for determination of their weight. The commonly applied one contains orthophosphoric acid as etchant and chromium trioxide as the corrosion inhibitor of metallic substrate. The latter, due to its toxicity, should be replaced, potentially with sodium molybdate. When sodium molybdate is dissolved in orthophosphoric acid, molybdophosphoric acid is formed. In this work the kinetics of dissolution of anodic coating was studied in 0.5 M H 3 PO 4. Moreover, the influence of the initial concentration of Na 2 MoO 4 in this solution was established. It was shown that molybdophosphoric acid species adsorb onto the surface and within the pores of anodic coating and decrease its dissolution rate in acidic solution. The mechanism of this process was evaluated by using Electrochemical Impedance Spectroscopy. Analysis of the impedance spectra revealed that adsorbed molybdophosphoric acid species increase the capacitance of the porous part of the coating from 0.7 to 1.1 μF and the resistance of its barrier layer from 0.3 MΩ to 2 MΩ in the solutions containing 0 and 25 mM of Na 2 MoO 4 respectively. The corrosion potential of the specimens also increased from −400 mV vs. Standard Hydrogen Electrode to −200 mV in the solutions containing >25 mM of Na 2 MoO 4. Highlights • Molybdophosphoric acid adsorbs onto the surface of the coating. • Molybdophosphoric acid penetrates within the pores of the coating. • Molybdophosphoric acid increases the corrosion potential of the anodised specimens. • The capacitance of the coating and the resistance of the barrier layer increase. • Molybdophosphoric acid decreases the rate of dissolution of the anodic coatings. [ABSTRACT FROM AUTHOR]

Due to the progressive climate changes, increasing demand for cooling is observed. Therefore, ecological alternatives to conventional cooling systems based on electricity are analysed. One of the promising solutions are adsorption chillers which can be powered by low grade thermal energy sources such as waste heat, solar power and heat produced in cogeneration. However, contemporary adsorption chillers achieve lower COP (coefficient of performance) when compared to conventional electricity-driven compression refrigerators. Refrigeration capacity of the adsorption chiller is obtained with the use of thermal effects which occur during adsorption and desorption processes on porous media and the intensification of this phenomena is currently one of the most important research challenges. The paper presents development of guidelines to build novel coated construction of adsorption beds. The criterion for selection of optimum bed components in terms of improving COP of the adsorption chillers dedicated to air conditioning has been defined. Silica gel has been indicated as the most favorable sorbent for modification of the bed construction with glue. [ABSTRACT FROM AUTHOR]

In recent years, artificial intelligence has become increasingly popular and is more often used by scientists and entrepreneurs. The rapid development of electronics and computer science is conducive to developing this field of science. Man needs intelligent machines to create and discover new relationships in the world, so AI is beginning to reach various areas of science, such as medicine, economics, management, and the power industry. Artificial intelligence is one of the most exciting directions in the development of computer science, which absorbs a considerable amount of human enthusiasm and the latest achievements in computer technology. This article was dedicated to the practical use of artificial neural networks. The article discusses the development of neural networks in the years 1940–2022, presenting the most important publications from these years and discussing the latest achievements in the use of artificial intelligence. One of the chapters focuses on the use of artificial intelligence in energy processes and systems. The article also discusses the possible directions for the future development of neural networks. [ABSTRACT FROM AUTHOR]

Chemical looping combustion (CLC) is one of the most advanced technologies allowing for the reduction in CO2 emissions during the combustion of solid fuels. The modified method combines chemical looping with oxygen uncoupling (CLOU) and in situ gasification chemical looping combustion (iG-CLC). As a result, an innovative hybrid chemical looping combustion came into existence, making the above two technologies complementary. Since the complexity of the CLC is still not sufficiently recognized, the study of this process is of a practical significance. The paper describes the experiences in the modelling of complex geometry CLC equipment. The experimental facility consists of two reactors: an air reactor and a fuel reactor. The paper introduces the fuzzy logic (FL) method as an artificial intelligence (AI) approach for the prediction of SO2 and NOx (i.e., NO + NO2) emissions from coal and biomass combustion carried out in air-firing; oxyfuel; iG-CLC; and CLOU conditions. The developed model has been successfully validated on a 5 kWth research unit called the dual fluidized bed chemical looping combustion of solid fuels (DFB-CLC-SF). [ABSTRACT FROM AUTHOR]

Introduction: Recently, we demonstrated that digestive tract cancer (DTC) is associated with reduced fibrin clot permeability and impaired fibrinolysis. Aim: We investigated determinants of fibrinolysis in DTC patients. Material and methods: In 44 consecutive patients with DTC and 47 controls matched for age, sex, and cardiovascular risk, we evaluated fibrinolysis proteins, platelet activation markers, thrombin formation, together with plasma clot lysis time assays in the absence (CLT) and presence of carboxypeptidase potato inhibitor (CLT CPI) that blocks thrombin activatable fibrinolysis inhibitor (TAFI). Results: In the DTC group CLT (by 22.3%) and CLT CPI (by 27.4%) were longer compared with controls. The DTC patients had higher plasma fibrinolysis inhibitors, plasminogen activator inhibitor 1 (PAI-1) (by 18.2%), TAFI activity (by 17.3%), and antigen (by 11.2%). The patients had markedly increased platelet markers - soluble CD40 ligand (by 338%) and P-selectin (by 97%), together with von Willebrand factor (vWF) antigen (by 61%). Thrombin-antithrombin complexes (TAT) (by 48.7%) and soluble thrombomodulin (sTM) (by 17.2%) were also increased in the DTC group (all p < 0.05). Patients with high-grade tumours (n = 26) compared with remainders (n = 18) had longer CLT, higher tissue-type plasminogen activator antigen, both TAFI antigen and activity levels, vWF, and sTM. Multiple regression analysis after adjustment for potential confounders showed that independent predictors of CLT in DTC patients were TAT, TAFI activity, and vWF. The only independent predictor of CLT CPI was TAT. Conclusions: Hypofibrinolysis in DTC patients is largely driven by enhanced thrombin generation, TAFI, and endothelial injury. [ABSTRACT FROM AUTHOR]

The paper demonstrates that the possibilities of producing reliable long-term energy forecast are limited. Global economic growth is so dynamic that the changes resulting from scientific and technological progress, which we experience, do not allow for the identification of goals over longer time intervals. For this reason, forecasting up to 2035, 2040, 2060 is devoid of its fundamental value, which is the reliability of results obtained. Are predictions to be conservative (this applies to richer countries) or are they to produce a paradigm shift by, for example, strongly imposing the requirement of increasing energy security, which is important for our country? In light of the broadness of the issues, this paper is limited to considerations relating to forecasting the primary energy demand. Detailed examples are presented for the Polish energy system. [ABSTRACT FROM AUTHOR]

The oxidation behavior of the nickel base Alloy 602 CA in atmospheres, relevant to gas separation units in fossil fired power plants, was investigated in the temperature range 800 to 1100 °C. Isothermal oxidation kinetics were determined in Ar-7 %HO, Ar-4 %H-7 %HO, Ar-20 %O-7 %HO and, for comparative purposes, in Ar-20 %O. The alloy formed an external alumina scale during oxidation at 800 °C, regardless of the atmosphere. Increasing the temperature results in gradual replacement of the alumina scale by an external chromia layer and internal alumina precipitates. The chromia growth rate is affected by the gas composition, due to titanium incorporation in the scale and outwardly protruding metallic nodules. The external alumina scale formation was strongly affected by surface cold work during specimen grinding. This effect, which promoted external alumina scale formation, was retained during exposure at 800 °C but was rapidly lost at higher temperatures resulting in external chromia scale formation and internal oxidation of aluminum. [ABSTRACT FROM AUTHOR]

Ligation of intersphincteric fistula tract in treatment of anal fistulas (LIFT) is being said to have satisfactory results in short and long follow up, with low risk of complications. This study was designed to evaluate the results in patients with complex and recurrent fistulas in comparison with simple transsphincteric anal fistulas. The aim of the study was to present a single-center experience in LIFT procedure in treatment of both simple and complex anal fistulas, including recurrent fistulas, in comparison with a review of current literature. Material and methods. A series of 17 patients were qualified to LIFT procedure. 5 patients were treated for simple transsphincteric, 6 for complex fistulas, 6 with fistulas recurrent after fistulotomy. Median age was 47, most of the patients were male (16/17). Mean follow up was 11 months. Results. Mean operating time was 55 minutes counting from surgical site disinfection to final dressing of the wound. Of the 17 patients the overall success rate was 53%. As expected, best results were achieved in patients with simple fistulas (80% success rate), then complex (50%), and recurrent fistulas (only 33%). There were no early nor late complications of the surgery. Conclusion. As expected, in simple transsphincteric fistulas the results were satisfactory, taking into account low complication rate. Complex and recurrent fistulas seem to be risk factors of LIFT failure. The results are consistent with data published by other authors, based on the review of the current literature, and it seems there is still room for improvement, so further research is required. [ABSTRACT FROM AUTHOR]

One of the main disadvantages of conventional fixed-bed adsorption chillers is the low coefficient of performance due to the high voidage of the sorbent beds. The common method, which can help to handle this problem, is modifying the beds' design, including the application of fluidization. An innovative idea, shown in the article, constitutes in the use of the fluidized bed of sorbent, instead of the conventional, fixed-bed, commonly used nowadays in the adsorption chillers. Bed-to-wall heat transfer coefficients for fixed and fluidized beds of adsorbent are determined in the study. Effects of Sorbent particles diameters and velocities of fluidizing gas are discussed in the study. The calculations confirmed that the bed-to-wall heat transfer coefficient in the fluidized bed of adsorbent is much higher than that in a conventional bed. The proposed idea allows significantly reducing the size of a chiller and overcome the main reason for the limited dissemination of the adsorption cooling technology. [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to evaluate the risk factors of lymph nodes metastases (LNM) in patients with papillary thyroid cancer (PTC) and coexisting Hashimoto's thyroiditis (HT). Patients and methods: This was a retrospective cohort study of patients with PTC and HT who had undergone total thyroidectomy (TT) with central neck dissection (CND) over an 11-year period (between 2002 and 2012). Pathological reports of all eligible patients were reviewed. Multivariable analysis was performed to identify risk factors of LNM. Results: During the study period, PTC was diagnosed in 130 patients with HT who had undergone TT with CND (F/M ratio = 110:20; median age, 52.4 ± 12.7 years). Multifocal lesions were observed in 28 (21.5 %) patients. LNM were identified in 25 of 28 (89.3 %) patients with multifocal PTC and HT versus 69 of 102 (67.5 %) patients with a solitary focus of PTC and HT ( p = 0.023). In multivariable analysis, multifocal disease was identified as an independent risk factor for LNM (odds ratio, 3.99; 95 % confidence interval, 1.12 to 14.15; p = 0.033). Conclusions: Multifocal PTC in patients with HT is associated with an increased risk of LNM. Nevertheless, the clinical importance of this finding needs to be validated in well-designed prospective studies. [ABSTRACT FROM AUTHOR]