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Carbon dioxide sequestration by industrial wastes through mineral carbonation: Current status and perspectives
- Xiaodan Lin
- Yingshuang Zhang
- Hongwen Liu
- Grzegorz Boczkaj
- Yijun Cao
- Chongqing Wang
2024 JOURNAL OF CLEANER PRODUCTION
Mineral carbonation using natural minerals or industrial wastes is a safe and promising strategy for CO2 sequestration. Application of industrial wastes for this purpose has significant ecological and environmental value, which is one of the key green technologies in the global carbon mitigation. This review summarizes the current research status of CO2 mineralization by industrial wastes. This work surveys the mechanisms and capacities of CO2 mineralization using different industrial wastes (mainly steel slags, blast furnace slags, coal fly ash, waste gypsum, and red mud), evaluates the influence of carbonation pathways and process parameters on the CO2 sequestration capacity, and analyzes the current industrial application status of CO2 sequestration using industrial wastes. Direct aqueous carbonation and indirect carbonation are the two most studied and promising mineralization routes. The leaching-mineralization cycle process has great potential for industrial application, especially for the treatment of coal fly ash, steel slag and other wastes containing calcium oxide, owing to the stable cycle performance of the absorbers. Researchers pay more attention to CO2 mineralization by steel slag compared to other wastes, and the capacity of CO2 mineralization varies greatly for different wastes. Several reports already reported carbonation effectiveness up to 100%. A CO2 sequestration capacity reached 536 g/kg for steel slag and 361 g/kg of blast furnace slag, revealing superior properties of these materials. CO2 sequestration using industrial wastes benefits CO2 emission reduction and comprehensive utilization of industrial wastes. To overcome the problem of the high energy consumption for regeneration of absorbent, a novel integrated CO2 absorption-mineralization process is currently widely studied. A possibility of co-production of value-added products - like different types of zeolite or lithium orthosilicate based adsorbents was highlighted, improving the economic balance of the overall process. More studies on pilot scale should be performed, to fully confirm the feasibility of developed technologies. Application of these developments is still faced with significant issues, including low carbonation efficiency, poor product quality, high process cost, and insufficient mass and heat transfer.
Carbon Nanomaterials in Seed Priming: Current Possibilities
- José Daniel da Silva Fonseca
- Ewa Wojciechowska
- Joanna Kulesza
- Bráulio Silva Barros
2024 ACS Omega
The prevailing agricultural system has become deeply ingrained and insufficient due to outdated practices inherited from the Green Revolution, necessitating innovative approaches for sustainable agricultural development. Nanomaterials possess the potential to significantly improve the efficient utilization of resources while simultaneously encouraging sustainability. Among these, carbonaceous nanomaterials have found diverse applications in agriculture, exhibiting remarkable capabilities in this domain. Notably, using biowaste to produce these materials makes them both cost-effective and environmentally friendly for seed priming. Seed priming is a technique that can potentially enhance germination rates and stress tolerance by effectively regulating gene pathways and metabolism. This review provides a comprehensive summary of recent progress in the field, highlighting the challenges and opportunities of applying carbonaceous materials in seed priming to advance sustainable agriculture practices. The existing reviews provide a general overview of using carbonaceous materials (graphene and derivatives) in agriculture. Yet, they often lack a comprehensive examination of their specific application in seed-related contexts. In this review, we aim to offer a detailed analysis of the application of carbonaceous materials in seed priming and elucidate their influence on germination. Furthermore, the review shows that crop response to carbonaceous nanomaterials is linked to material concentration and crop species.
Carburization Behavior of High-Grade Pellets After Direct Reduction in Pure Hydrogen
- Angelo Perrone
- Pasquale Cavaliere
- Behzad Sadeghi
- Leandro Dijon
- Aleksandra Mirowska
- Damian Koszelow
2024 Journal of Sustainable Metallurgy
Carburization is a critical aspect in the iron and steel industry as it significantly affects the mechanical and chemical properties of the final product. This study provides a comprehensive analysis of the carburization potential of high-grade quality iron ore pellets after direct reduction in pure hydrogen. The results show that the porosity of the pellets has a significant impact on the efficiency and success of the direct reduction process with hydrogen. The reduction process can be completed at a lower temperature in pure hydrogen compared to carbon monoxide, with the iron carbide concentration peaking at temperatures up to 500 °C before decreasing with further temperature increases. The uniform distribution of SiO2, Al2O3, and CaO is critical to the carburizing process and affects the final properties of the steel. An increased degree of metallization and porosity are associated with an improved carburizing tendency. This study highlights the intricate interplay between temperature, carbon sources, and the resulting equilibrium concentration of iron carbides and provides insights into the complex dynamics of this phenomenon.
Cascaded Buck Hybrid Interlink Converter for Multiple-Input / Multiple-Output Operation
- Ahmed Awadelseed
- Arkadiusz Lewicki
- Charles Odeh
- Atif Iqbal
2024 Pełny tekst
The provision of isolated- and non-isolated DC output voltages by Power electronics power-conditioning devices in the recent ‘green-energy-revolution’ era is on course. In this paper, a structure for multi-input multi-output(MIMO) DC–DC buck converter is proposed to generate output voltages of varying levels with fewer component-count. The DC output voltage of each of the constituting buck converters can be used independently or cascaded with one another, depending on the output load voltage requirement. The converter operational modes are analysed and its gain models are derived. Also, expressions for the efficiency and power density of the proposed buck converter are presented. Distinct features of proposed converter are: its simplified configuration, high input/output power density, low-cost involvement, reduction of ripple amplitudes of the source currents, and possibility of deploying energy sources with different voltage-current characteristics. High voltage gain, and bidirectional power flow can be achieved in the converter operations. Experimental results on a laboratory prototype of the proposed MIMO validated the presented DC-DC buck converter topological concept
Catalysts for advanced oxidation processes: Deep eutectic solvents-assisted synthesis – A review
- Amir Mohammad Sheikh Asadi
- Łukasz Cichocki
- Ali Atamaleki
- Marjan Hashemi
- Holger Lutze
- Muhammad Imran
- Lingshuai Kong
- Chongqing Wang
- Grzegorz Boczkaj
2024 Pełny tekst Water Resources and Industry
New catalyst synthesis techniques, including green materials, are extensively studied for heterogeneous photocatalytic advanced oxidation processes (AOPs) on spotlight of sustainable development. Deep eutectic solvents (DESs) started to be used in this field as environmentally friendly alternative to ionic liquids (ILs). During the catalyst synthesis, DESs can act as stabilizers, capping agents, structure directing agents, templates, hydrolyzing agents, etching agents, intercalators, and latent supramolecular catalysts. Importantly, DESs have exhibited the ability to significantly influence catalyst morphology, functionalization and photocatalytic properties (confirmed both for classic UV lamps and light emitting diode (LED)), including band-gap modification. DESs positive effect was proved for a variety of materials, including metal oxides, metalorganic (MO) complexes and doped materials, MXene (MAX phase etching in DES environment), inorganic-organic hybrids, carbo-catalysts. Substantial enhancements were obtained for modification of photocatalytic materials like TiO2, ZnO, MnO2, iron oxides, ceria oxides, CdS, bismuth based photocatalysts and biochar modification. In this aspect, a particular role of DESs was confirmed for synthesis of nanomaterials in a form of nanoparticles, nanopowders or nanosheets. Effectiveness was further increased by oxidants such as hydrogen peroxide, persulfates and Fenton process. Effective application of DES-modified catalysts was confirmed for degradation of dyes (Rhodamine B, Reactive orange 16, Safranine, Orange II, methylene blue), pharmaceuticals and antibiotics (Cefixime, Tetracycline, Oxytetracycline, Flumequine, Sulfamethaxazole), PFASs (Perfluorooctanoic acid) and Cr(VI). This reveals high potential of DES based photocatalysts for environmental engineering and remediation. There are still remaining a significant gaps in our understanding of the roles and impacts of DESs in AOPs. Furthermore, there is an absence of data regarding the recovery of DESs in the catalyst synthesis processes applied in AOPs. Addressing this aspects is vital for economic and environmentally friendly applications. As research progresses, it is essential to unravel the intricacies of DES-mediated catalyst synthesis and their broader consequences.
Catalytic activity of Ni-MgAl2O4 modified with transition metal (Ti, Mo, W) carbides as potential catalysts for resource recovery via dry reforming of waste plastics
- Ewelina Pawelczyk
- Izabela Wysocka
- Tomasz Dymerski
- Jacek Gębicki
2024 Pełny tekst CATALYSIS TODAY
The growing amounts of plastic waste and CO2 emissions are two environmental threats that require urgent attention. Pyrolysis combined with dry reforming (PCDR) is a technology that allows both CO2 utilization and resource recovery from waste plastic. New catalysts for PCDR are crucial for developing efficient and stable processes that can be widely implemented in the industry. In this study, Ni/MgAl2O4 catalysts modified using different transition metal (Ti, Mo, W) carbides were investigated in the PCDR of low-density polyethylene (LDPE) and polystyrene (PS) with emphasis on syngas yield, H2/CO ratio, product distribution, and catalyst deactivation. In addition, the effect of reforming temperature and process pressure was investigated. The catalysts were characterized using H2-TPR, CO2-TPD, N2 physisorption, XRD, TEM, XPS and TGA. The combined characterization and activity tests demonstrated that modification with different metal carbides affects the structure and activity of Ni/MgAl2O4 catalysts in relation to product yields, syngas composition, and catalyst stability. The investigation revealed that modification of nickel catalysts with different transition metal carbides enables manipulation of syngas composition, which is of great importance because different industrial processes require synthesis gas with different H2:CO ratios. Moreover, mixed outcomes were observed when different plastic feedstocks were used in the PCDR, indicating that different metal carbide-modified catalysts may be suitable for the process depending on the feedstock used. Regarding the effectiveness of synthesis gas production and catalyst stability, the most promising catalyst was the Ni-TiC/MgAl2O4 catalyst. According to the obtained results, modification with TiC resulted not only in increased synthesis gas production but also in reduced carbon deposition in PCDR of both LDPE and PS.
Category Adaptation Meets Projected Distillation in Generalized Continual Category Discovery
- Grzegorz Rypeść
- Daniel Marczak
- Sebastian Cygert
- Tomasz Trzciński
- Bartłomiej Twardowski
2024
"Generalized Continual Category Discovery (GCCD) tackles learning from sequentially arriving, partially labeled datasets while uncovering new categories. Traditional methods depend on feature distillation to prevent forgetting the old knowledge. However, this strategy restricts the model’s ability to adapt and effectively distinguish new categories. To address this, we introduce a novel technique integrating a learnable projector with feature distillation, thus enhancing model adaptability without sacrificing past knowledge. The resulting distribution shift of the previously learned categories is mitigated with the auxiliary category adaptation network. We demonstrate that while each component offers modest benefits individually, their combination – dubbed CAMP (Category Adaptation Meets Projected distillation) – significantly improves the balance between learning new information and retaining old. CAMP exhibits superior performance across several GCCD and Class Incremental Learning scenarios. The code is available on Github."
Catheter-induced coronary artery and aortic dissections. A study of the mechanisms, risk factors, and propagation causes
- Jacek Klaudel
- Michał Glaza
- Barbara Klaudel
- Wojciech Trenkner
- Krzysztof Pawłowski
- Marek Szołkiewicz
2024 Pełny tekst Cardiology Journal
Background: Only the incidence, management, and prognosis of catheter-induced coronary artery and aortic dissections have been systematically studied until now. We sought to evaluate their mechanisms, risk factors, and propagation causes. Methods: Electronic databases containing 76,104 procedures and complication registries from 2000– –2020 were searched and relevant cineangiographic studies adjudicated. Results: Ninety-six dissections were identified. The overall incidence was 0.126%, and 0.021% for aortic injuries. The in-hospital mortality rate was 4.2%, and 6.25% for aortic dissections. Compared to the non-complicated population, patients with dissection were more often female (48% vs. 34%, p = 0.004), with a higher prevalence of comorbidities such as hypertension (56% vs. 25%, p < 0.001) or chronic kidney disease (10% vs. 4%, p = 0.002). They more frequently presented with acute myocardial infarction (72% vs. 43%, p < 0.001), underwent percutaneous coronary intervention (85% vs. 39%, p < 0.001), and were examined with a radial approach (77% vs. 65%, p = 0.011). The most prevalent predisposing factor was small ostium diameter and/or atheroma. Deep intubation for support, catheter malalignment, and vessel prodding were the most frequent precipitating factors. Of the three dissec- tion mechanisms, ‘wedged contrast injection’ was the commonest (the exclusive mechanism of aortic dissections). The propagation rate was 30.2% and led to doubling of coronary occlusions and aortic extensions. The most frequent progression triggers were repeat injections and unchanged catheter. In 94% of cases, dissections were inflicted by high-volume operators, with ≥ 5-year experience in 84% of procedures. The annual dissection rate increased over a 21-year timespan. Conclusions: Catheter-induced dissection rarely came unheralded and typically occurred during ur- gent interventions performed in high-risk patients by experienced operators. (Cardiol J) Key words: catheter-induced coronary dissection, iatrogenic aortocoronary dissection, percutaneous coronary intervention complications
Cathodes for Sodium‑Ion Batteries
- Monika Wilamowska-Zawłocka
- Anita Cymann-Sachajdak
- Zuzanna Zarach
- Magdalena Graczyk-Zajac
2024
Advances in lithium-ion battery (LIBs) technology have improved living conditions around the globe. However, there are increasing concerns regarding the sustainability and criticality of materials (lithium and cobalt) for LIBs. Considering sodium’s superiority in cost and abundance, the development of electrode materials for sodium-ion batteries (NIBs) has been intensively revisited. Limited types of structures are suitable for intercalation sodium ions due to their preferential sixfold coordination. Layered transition metal oxides and polyanion compounds can hold sodium cations in six-coordinated geometry. Additionally, Prussian Blue analogs (PBAs) with open interstitial sites exhibit Na-ion insertion properties. Sodium layered metal oxides demonstrate advantages such as high capacities and low price, but also exhibit problems like low operating voltage or structural instability upon multiple phase transitions during charge–discharge cycles. Polyanion-type compounds exhibit 3D structures with open channels that facilitate the diffusion of alkali metal ions. Moreover, the highly stable frameworks for reversible Na-ion insertion assure a good cyclability. PBAs possess two metal centers coordinated by cyano-groups. Tailoring the metal centers in this three-dimensional framework provides a tool to vary the redox potential of the compound and the size of the interstitial cavities. These three classes of compounds will be described in this chapter considering their composition, structure, electrochemical performance, sustainability, and cost.
CAUSES OF DEFECTS AND DAMAGE TO BRICK MASONRY ELEMENTS IN HISTORIC BUILDINGS
- Maciej Niedostatkiewicz
- Tomasz Majewski
2024 Pełny tekst Civil and Environmental Engineering Reports
Ceramic brick masonry elements constitute the largest number of structural systems of historic buildings, especially sacral and public utility buildings. In the past, they were also very commonly used as a material for the construction of military facilities. Historic buildings and masonry structures undergo destructive processes over time, the course of which can be very diverse and depends, among other things, on the physicochemical properties of the materials, the type of structure, the age of the building, working conditions and random conditions and events. The paper is an engineering review of the causes of damage to masonry structures and indicates the need for cooperation between representatives of various specialties of science and technology, in particular architectural historians, specialists in the field of conservation of monuments, structural engineers and specialists in the field of geotechnics, geology, hydrogeologists and meliorators in order to ensure the protection of masonry structures in historic buildings.
Cavitation and Solid-State Post-Condensation of Polyethylene Terephthalate: Literature Review
- Waldemar Karaszewski
- Paweł Wawrzyniak
- Artur Różański
2024 Materials
Polyethylene terephthalate (PET) is widely used in bottle production by stretch blow molding processes (SBM processes) due to its cost-effectiveness and low environmental impact. The presented literature review focuses on microcavitation and solid-state post-condensation effects that occur during the deformation of PET in the SBM process. The literature review describes cavitation and microcavitation effects in PET material and solid-state post-condensation of PET on the basis of a three-phase model of the PET microstructure. A three-phase model of PET microstructure (representing the amorphous phase in two ways, depending on the ratio of the trans-to-gauche conformation of the PET macromolecule and the amount of free volume) with a nucleation process, a crystallization process, and the use of positron annihilation lifetime spectroscopy (PALS) to analyze PET microstructure are discussed in detail. The conceptual model developed based on the literature combines solid-state post-condensation with microcavitation via the diffusion of the post-condensation product. This review identifies the shortcomings of the developed conceptual model and presents them with five hypotheses, which will be the basis for further research.
Celowe zanieczyszczanie pilotów w łączu w górę w interfejsie 5G NR
- Jarosław Magiera
- Piotr Rajchowski
2024 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
Referat poświęcono zagadnieniu zakłócania sygnałów pilotowych w interfejsie radiowym 5G NR. Przedstawiono charakterystykę sygnału referencyjnego DMRS oraz uwarunkowania możliwości jego selektywnego zakłócenia. Opisano schemat transmisji w kanale fizycznym PUSCH, zaimplementowany w oprogramowaniu Sionna. Zaprezen-towano model symulacyjny oraz założenia badań wpływu zanieczyszczenia pilotów na jakość transmisji. Przedsta-wiono wyniki badań w zależności od mocy źródła zakłóce-nia oraz od jego lokalizacji względem stacji bazowej.
Centrifuge modelling of tapered wall jacked into dense sand
- Lech Bałachowski
- Worku Firomsa Kabeta
- Luc Thorel
- Matthieu Blanc
- Thierry Dubreucq
2024 Pełny tekst
A series of static penetration tests of trapezoidal walls in dense Fontainebleau sand were performed in the geotechnical centrifuge at Gustave Eiffel University. The models of wall with three different shapes (straight profile with thickness D=16mm, 0.75 degree and 1.5 degree of taper angle) but with the same volume were used. The soil mass was instrumented with five stress cells located at two levels at 2D, 4D and 6D distance from the wall axis to follow the stress state changes during the model penetration. Moreover, three pressure sensors were integrated on the model surface to track the changes of normal stress during the continuous penetration of the wall. Thus for the three walls of different geometry the evolution of the following variables is considered during monotonic penetration of the wall: 1) total vertical force; 2) horizontal stresses in the soil mass; 3) normal stresses on the wall surface.
CE-UV method for the determination of catecholamine metabolites from baby pee-covered diapers
- Jose Grau
- Magdalena Fabjanowicz
- Izabela Drążkowska
- Justyna Płotka-Wasylka
2024 JOURNAL OF CHROMATOGRAPHY A
A method has been developed for the analysis of vanillylmandelic acid, homovanillic acid, and 5-hydroxyindoleacetic acid from baby urine as biomarkers of neuroblastoma in infants. Disposable diapers were employed as sampling devices in order to guarantee a low invasiveness during this step. The proposed method consists on a simple extraction step with water from the used diaper followed by the measurement using capillary electrophoresis with UV detection. The Box-Behnken design (BBD) was utilized to optimize the process of extracting catecholamine metabolites from the examined samples. The variables of the sample preparation step were optimized and the method was validated obtaining limits of quantification of 1.65 μg mL−1, good intraday and inter-day precision with RSDs under 15 %. Finally the method was applied to real samples collected from the Department of Neonatology, University Clinical Centre (Gdańsk, Poland). The greenness of the proposed method was also evaluated with different tools (i.e., AGREEPrep and GAPI) with satisfactory results, which allow to state that the method can be considered green. Moreover, its practicality was evaluated by application of BAGI tool, proving to be a practical and economical method to be applied in routine laboratories for determination of catecholamine metabolites in urine-type samples.
CFD COUPLING OF VOF MODEL WITH ARRHENIUS EQUATION FOR ANALYSIS OF LASER-INDUCED THERMAL DEACTIVATION OF E. COLI
- Aimad Koulali
- Piotr Radomski
- L. De Sio
- Dariusz Mikielewicz
- Paweł Ziółkowski
2024 Pełny tekst
Understanding bacterial deactivation at the micro-scale, particularly with E. coli, is crucial for advancing microbiology and has promising applications in biomedical research. In this research contribution, we investigate the thermal inactivation of E. coli bacteria using gold nanoparticles irradiated by a green 1-W laser within a microfluidic chamber. The microfluidic device comprises a fluidic chamber filled with a thin film of water and air (1 mm thick). The chamber is constructed with 1 mm PDMS coating on the top and side walls, and 1 mm borosilicate glass on the bottom. Computational Fluid Dynamics (CFD) calculations are executed using ANSYS Fluent software employing the Volume of Fluid (VOF) multi-phase model. Bacterial deactivation is described by a first-order kinetic model, while the Arrhenius equation is employed to define the decay coefficient. The light-heat conversion is modeled using a literature-based approach, validated against experimental data. Our findings affirm the efficacy of the proposed physical model (laser + gold nanoparticles) for bacterial inactivation. Additionally, we propose an innovative approach by coupling bacterial inactivation equations and VOF model, opening avenues for further applications in the field.
Chained machine learning model for predicting load capacity and ductility of steel fiber–reinforced concrete beams
- Torkan Shafighfard
- Farzin Kazemi
- Faramarz Bagherzadeh
- Magdalena Mieloszyk
- Doo-Yeol Yoo
2024 Pełny tekst COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING
One of the main issues associated with steel fiber–reinforced concrete (SFRC) beams is the ability to anticipate their flexural response. With a comprehensive grid search, several stacked models (i.e., chained, parallel) consisting of various machine learning (ML) algorithms and artificial neural networks (ANNs) were developed to predict the flexural response of SFRC beams. The flexural performance of SFRC beams under bending was assessed based on 193 experimental specimens from real-life beam models. The ML techniques were applied to predict SFRC beam responses to bending load as functions of the steel fiber properties, concrete elastic modulus, beam dimensions, and reinforcement details. The accuracy of the models was evaluated using the coefficient of determination (R2), mean absolute error (MAE), and root mean square error (RMSE) of actual versus predicted values. The findings revealed that the proposed technique exhibited notably superior performance, delivering faster and more accurate predictions compared to both the ANNs and parallel models. Shapley diagrams were used to analyze variable contributions quantitatively. Shapley values show that the chained model prediction of ductility index is highly affected by two other targets (peak load and peak deflection) that show the chained algorithm utilizing the prediction of previous steps for enhancing the prediction of the target feature. The proposed model can be viewed as a function of significant input variables that permit the quick assessment of the likely performance of SFRC beams in bending.
Challenges and future prospectives of MXenes
- Azka Akhlaq
- Shoomaila Latif
- Mohammad Imran
- Ayesha Javaid
- Grzegorz Boczkaj
2024
In the context of nanotechnology, MXenes gained considerable attention as two-dimensional (2D) materials derived from layered transition metal carbides, nitrides, and carbonitrides. These materials display distinct characteristics with promising implications for a variety of practical applications. This book chapter provides an extensive exploration into MXenes’ fundamental concepts, such as how they are classified based on various composition factors and relevant synthesis techniques. An important aspect is covering diverse applications that range from energy conversion and storage and catalysis and chemical reactions to electronics, optoelectronics, and even biomedicine. Moreover, this chapter provides an insight into future prospects, bottlenecks, and vital considerations. Recognizing this, it serves as a comprehensive resource, offering readers a well-rounded understanding of MXene’s foundational concepts alongside its impressive applications across various scientific domains.
Changes in evaporation patterns and their impact on Climatic Water Balance and river discharges in central Poland, 1961–2020
- Arkadiusz Bartczak
- Michał Krzemiński
- Andrzej Araźny
2024 Regional Environmental Change
This study investigates the changes in precipitation and evaporation patterns and their impact on Climatic Water Balance and river discharges in central Poland from 1961 to 2020. The analysis focuses on two “normal” periods, 1961–1990 and 1991–2020 (according to the World Meteorological Organization). Bartlett’s test and the Kruskal–Wallis rank sum test were used to assess the homogeneity of variances and compare distributions of analyzed variables over two “normal” periods. The probability density functions were estimated using a kernel density estimator with a Gaussian kernel function. Significant findings indicate alterations in evaporation rates and shifts in water balance dynamics. Mean evaporation increased from 530.8 to 637.9 mm, leading to a notable decrease in the mean Climatic Water Balance from 1.1 to − 107.5 mm (in the periods 1961–1990 and 1991–2020, respectively). Additionally, rivers showed reduced mean annual discharges (from 4.28 to 3.01 m3·s−1 and 1.25 to 0.87 m3·s−1, for the Zgłowiączka and Skrwa Lewa rivers, respectively). These climatic changes in central Poland have substantial implications for regional water resources, especially in spring and summer and particularly in agricultural areas, potentially exacerbating drought conditions and impacting agricultural productivity mainly in the warm half-year.
Characteristics of Anthropogenic Pollution in the Atmospheric Air of South-Western Svalbard (Hornsund, Spring 2019)
- Filip Pawlak
- Kozioł Krystyna
- Wanda Wilczyńska-Michalik
- Mikołaj Worosz
- Marek Michalik
- Sara Lehmann-konera
- Żaneta Polkowska
2024 Water
The character of atmospheric pollution and its impact on surface waters may vary substantially in space, and hence, we add a potentially important location for the studies of atmospheric air pollution to the map of the High Arctic. We have investigated the anthropogenic particle characteristics and selected persistent organic pollutant concentrations, in a priorly unmonitored location in the Arctic (Svalbard), exposed to a climatic gradient. Single-particle analysis of PM indicates that besides the prevailing natural aerosol particles, anthropogenic ones were present. The likely anthropogenic origin of some particles was established for spherical Fe-rich or aluminosilicate particles formed in high-temperature processes or metal-rich particles of the chemical composition corresponding to industrial products and atypical for natural minerals; soot, tar balls, and secondary sulfate were also likely of anthropogenic origin. Some of the observed anthropogenic particles could only come from remote industrial sources. POP concentrations indicated a background of LRAT, consistent with the ΣPCB concentrations and volatility profile. However, the ΣDDX composition indicating aged sources and an order of magnitude higher concentrations of both ΣDDXs and ΣHCHs than at other High Arctic monitoring stations indicate their potential source in two types of re-emission from secondary sources, i.e., from seawater and snowpack, respectively.
Characteristics of silver-dopped carbon nanotube coating destined for medical applications
- Dorota Rogala-Wielgus
- Beata Majkowska-Marzec
- Andrzej Zieliński
2024 Pełny tekst Materials Today Communications
Carbon nanotubes are materials demonstrating outstanding mechanical, chemical, and physical properties and are considered coatings of titanium implants. The present research is aimed to characterize the microstructure and properties of the multi-wall carbon nanotubes (MWCNTs) layer decorated with silver nanoparticles (Ag NPs) on the Ti13Nb13Zr alloy destined for long-term implants. The electrophoretic deposition of coatings was performed in a two-stage process, at first at 0.25 wt. pct. of MWCNTs, and next at 0.30 wt. pct. of Ag NPs content in the bath. The SEM, EDS, AFM, Raman spectroscopy, nanoindentation tests, nano-scratch test, wettability assessments, and corrosion tests were carried out. The effects of the presence of Ag NPs onto the MWCNTs coating were observed as the roughness increased to 0.380 µm and thickness to 5.26 µm, the improved adhesion and corrosion resistance, the water contact angle of 62.94◦, the decreased nanohardness, Young`s modulus and resistance to plastic deformation under load, and slightly improved adhesion. The obtained results can be explained by a specific two-layer structure of the coating, in which the Ag NPs agglomerates create the coating less porous and permeable, but softer structure. Future research will focus on the improvement of the adhesion of the component coatings in different ways.