Complex Composition Research Articles

Comparative analysis of cytology of rat bronchoalveolar lavage fluid after single exposure to metal oxide nanoparticles

Introduction. Human production activities (metallurgical, mining, electronics production and processing, batteries) are related to air pollution of the working area and the environments of complex composition aerosols. Among the aerosol components, ultrathin particles of the nanometer range (including metal nano-oxides) are considered to be the most dangerous. Due to their prevalence, study to assess the cytotoxicity of metal oxide nanoparticles are relevant.
 Material and methods. CuO, PbO, CdO, Fe2O3, NiO nanoparticle (NP) suspension were obtained by laser ablation. The study was done on white outbred female rats. A single intratracheal instillation of different chemical NPs was performed (in dose 0.5 mg/animal); control animals received a similar amount of deionized water. A day after the NP instillation bronchoalveolar lavage (BAL) was carried out with the subsequent assessment of its cytological indices.
 Results. The cytotoxic action of the studied NPs, based on the cytological indices of the BAL fluid, is changed as follows (from greater to lesser): CuO NP > CdO NP > PbO NP > NiO NP > Fe2O3 NP.
 Limitations. Such physical characteristics of nanoparticles as solubility in water and biological fluids, charge, adsorption capacity, resistance to aggregation, hydrophobicity, adhesion to surfaces, and the ability to generate free radicals have not been studied. Extrapolation of data from rodents to humans shall be done with caution, since cytotoxicity has been characterized only based on the main cellular parameters.
 Conclusion. Bronchoalveolar lavage cytology can be used as an effective screening method for the cytotoxic effect of NPs.

Concentration, speciation and risk effects of multiple environmentally sensitive trace elements in respirable fine-grained fly ash

Respirable fine-grained fly ash (RFA) is captured very inefficiently by existing air purification devices of power plant, leading to increasing concerns regarding their migration and subsequent interaction with body due to fine particle size and its complex toxic composition. Trace elements of RFA in three groups with five different sizes between 8–13 µm were analyzed in terms of available concentration, speciation and risk effects. The concentration, pollution level and ecological risk level of elements in RFA were related to particle sizes. Chronic non-carcinogenic effect risk (NER) and carcinogenic effect risk (CER) were negatively correlated with particle size. The individual weight of exposed subjects, corresponding trace elements concentration and ingestion rate in RFA were three significant variables influencing CER. NER and CER had a tenfold exaggerated effect when calculated using total element concentration of RFA. In addition to individual differences and exposure conditions, trace element properties, speciation and available concentration were the dominant factor responsible for ecological and environmental effects of trace elements in RFA, following the order As>Ni, Mn>Cr>Pb>Cu>Zn. Results of this work highlight the effects and differences of trace elements in RFA on ecology and health, and provide a basis for further pollution control and human health warning.

Obtaining Value from Wine Wastes: Paving the Way for Sustainable Development

Winemaking is one of the main Portuguese industries and has significantly grown in recent years, thus increasing the quantity of obtained residues. These wastes have a complex chemical composition and structure, and, for this reason, their treatment and valorisation are simultaneously a challenge and an opportunity. After an overview of the wine industry and its wastes, this article intends to review the different solid winemaking wastes, highlighting their chemical composition and structural characteristics, as well as their main potential applications. These wastes, such as grape stalks, can be directly applied as a source of bioenergy in the form of pellets or subjected to chemical/biological processing, resulting in valuable food additives, materials, or chemicals. Grape seeds provide food grade oil with potential biomedical applications. Grape skins are a promising source of biologically active substances. The sugar fraction of grape pomace can be biologically converted to a wide variety of bioproducts, like bioethanol, biogas, polyhydroxyalkanoates, and bacterial cellulose. The integration of the different processes into a biorefinery is also discussed, considering the characteristics of the Portuguese wine industry and pointing out solutions to valorise their wastes.

Incorporating attribute-level aligned comparative network for generalized zero-shot learning

The key challenge of zero-shot learning (ZSL) is to sufficiently disentangle each latent attribute from the class-level semantic annotations of images, thereby achieving a desirable semantic transfer to unseen classes with the disentangled attributes. However, most existing studies tackle the ZSL task with a strict class-level alignment strategy that may yield insufficient disentanglement: (1) this strategy simply aligns holistic visual feature with its associated class-level semantic vector for each image; (2) the class-level semantic vectors have limited diversity and complex compositions of attributes. To address these issues, we propose an incorporating attribute-level aligned comparative network, i.e., IAAC-net, that develops the alignment strategy of ZSL to the attribute level. IAAC-net aims to establish diversified attribute-level and refined class-level alignments to facilitate attribute disentanglement and simultaneously improve zero-shot generalization. By further proposing a confusion-aware loss, the model is forced to rectify the disentanglement of indistinguishable attributes, which leads to a more accurate attribute disentanglement. The proposed IAAC-net yields significant improvements over the strong baselines, leading to new state-of-the-art performances on three popular challenging benchmarks, i.e., CUB, SUN, and AWA2.

Resource potential of municipal solid waste in Odesa Region

Despite the widespread use of the term "municipal solid waste" (MSW), the main regulatory and legislative documents of Ukraine use the term "household waste". International practice also does not have a clear definition of the "municipal solid waste" concept, however, there are a number of related terms. Municipal solid waste is defined as a waste that is generated in the course of human activity, accumulated in residential buildings and social institutions and considered as unsuitable for further use at places of its generation. As for the related terms used in foreign and national practice, the term “household waste”, i.e. waste generated directly by households, is more appropriate. Municipal solid waste is a heterogeneous mixture that has a complex waste composition and its quantitative and qualitative characteristics are not constant and depend on characteristics of a certain country, region, city or town where it was generated, season and other factors. Growing volumes of municipal solid waste is one of the components of growing anthropogenic load that poses a threat to environmental safety of the country's regions and public health and negatively affects the state of our environment. The main methods of such solid waste management in Ukraine include landfilling, incineration, recycling and recovery. Out of the total annual waste volume generated on the post-Soviet territories, 93% are taken to landfills or dumpsites, 4% – incinerated, and only about 3% – recycled.
 Therefore, creation and implementation of an effective system of solid waste management is an important task for ensuring environmental safety and sustainable development of the country's regions. Moreover, solid waste is a significant reserve for obtaining secondary material resources. According to the circular economy concept, almost all components of solid waste should be reused for production of new items. This will minimize negative impact on the environment and allow rational use of natural resources. The article analyses the current state of municipal solid waste management system in Odesa Region and assesses resource value of such waste. Secondary raw materials worth of almost UAH 1.4 million can be produced annually from the total flow of municipal solid waste in Odesa Region. And this figure does not take into account liquidity of food and other waste. After establishing an effective food and other organic waste management system, such amount may be significantly increased. Separation of resource-value components from the total solid waste flow and their subsequent use will help to reduce technogenic load on the environmental natural components and improve the overall environmental situation in Odesa Region.

Planar microfluid concentrators based on silagerm 8040 for sampling and sample preparation for the analy-sis of gas media

Exhaled air is a matrix with a complex molecular composition, including more than 3,500 components of various origins, the content of which can indicate the normal or pathological state of human health. One of the selective markers of diabetes formed in exhaled air is acetone. Its increased content (more than2.54 mg/m3) in exhaled air indicates excessive levels of glucose in the blood. To carry out a diagnostically reliable quantitative analysis of acetone in exhaled air, it is necessary to minimize random errors at all stages of sampling, concentration and calibration. The proposed MFC allow to carry out sample preparation and calibration under identical conditions, while combining the stages of sampling and concentration. The sample was concentrated using microfluidic systems based on Silagerm 8040 filled with a sorbent. Porapak-Q was chosen as the sorbent, which was pre-treated with ethyl alcohol vapour before filling into the channels. Sorption concentration in dynamic mode using an MFC was carried out by passing the resulting model gas mixture “acetone in air” with a concentration of 2.54 mg/m3 at t = 0oC until breakthrough appears. Desorption using the MFC based on Porapak-Q was carried out at temperatures of 50°C, 60°C, 70°C in dynamic mode by passing purified air at a rate of 0.5 ml/sec (desorption time is one second). The effluent was analysed by gas chromatography. The main advantage of this system is the ability to include it in a gas microchromatograph. The resulting analytical complex is mobile, which allows the usage for non-invasive diagnostics in non-laboratory conditions. Optimal concentration conditions using the MFC filled with Porapak-Q sorbent at which the maximum concentration coefficient of 43 was achieved have been established (tsorb=0oC; tdes=70oC, Vsorb=45 ml, tdes=1 sec). In a comparative analysis of the standard sampling method (using a Tedlar bag) and the method proposed using the MFC, it was found that the use of Tedlar bags for sampling exhaled air resulted in significant decrease in the accuracy characteristics (more than 30-65%) within 12 h, which is not applicable for diagnostic purposes. This fact was due to the sorption of the analyte on the walls of the bag and to eliminate undesirable effects it is necessary to use an additional step of sample drying. When the MFC was used for sampling, such a tendency was not observed, the accuracy characteristic did not decrease by more than 6-10% within 8 hours and no additional stages of drying the sample of exhaled air were required.

Simultaneous removal of brominated and chlorinated species during the production of oils by e-waste plastics catalytic hydropyrolysis

The production of added-value chemicals via pyrolysis of plastic wastes, such as those from electrical and electronic equipment (WEEE), needs addressing their usual contamination with halogens (mainly Br and Cl). This work compares the conversion via pyrolysis and hydropyrolysis of a real WEEE plastic, having a complex composition, in two different reactor configurations: down-flow (DF) and up-flow (UF). Likewise, the effects of incorporating a Pd/Al2O3 catalyst and using two different pressures (1 and 6 bar) have been assessed. With the DF mode, pyrolysis at 1 bar leads to an oil yield above 80 wt% and a total halogen content of about 600 ppm (vs 1600 ppm in the water-washed WEEE plastic). Under DF catalytic hydropyrolysis at 6 bar, this high oil yield is maintained while its dehalogenation degree is improved (142 ppm). Operating with the up-flow configuration, under 6 bar and H2 presence, leads to some reduction in the oil yield (about 70 wt%) but significantly decreases the oil halogen content (55 ppm Cl and total elimination of Br). These results have been related to the slower pyrolysis and longer residence time in the thermal zone of the UF configuration, which favours the halogen-trapping effect of the char fraction, and the pressure-enhanced hydrodehalogenation activity of the catalyst. This study highlights the environmental benefits of the proposed process, emphasizing the lower halogen content in the resulting oils and promoting a more sustainable approach to plastic waste valorisation.

Synergistic Sensitization of High-Grade Serous Ovarian Cancer Cells Lacking Caspase-8 Expression to Chemotherapeutics Using Combinations of Small-Molecule BRD4 and CDK9 Inhibitors.

Ovarian cancer is one of the most lethal gynecological cancers worldwide, with approximately 70% of cases diagnosed in advanced stages. This late diagnosis results from the absence of early warning symptoms and is associated with an unfavorable prognosis. A standard treatment entails a combination of primary chemotherapy with platinum and taxane agents. Tumor recurrence following first-line chemotherapy with Carboplatin and Paclitaxel is detected in 80% of advanced ovarian cancer patients, with disease relapse occurring within 2 years of initial treatment. Platinum-resistant ovarian cancer is one of the biggest challenges in treating patients. Second-line treatments involve PARP or VEGF inhibitors. Identifying novel biomarkers and resistance mechanisms is critical to overcoming resistance, developing newer treatment strategies, and improving patient survival. In this study, we have determined that low Caspase-8 expression in ovarian cancer patients leads to poor prognosis. High-Grade Serous Ovarian Cancer (HGSOC) cells lacking Caspase-8 expression showed an altered composition of the RNA Polymerase II-containing transcriptional elongation complex leading to increased transcriptional activity. Caspase-8 knockout cells display increased BRD4 expression and CDK9 activity and reduced sensitivities to Carboplatin and Paclitaxel. Based on our work, we are proposing three potential therapeutic approaches to treat advanced ovarian cancer patients who exhibit low Caspase-8 expression and resistance to Carboplatin and/or Paclitaxel-combinations of (1) Carboplatin with small-molecule BRD4 inhibitors; (2) Paclitaxel with small-molecule BRD4 inhibitors, and (3) small-molecule BRD4 and CDK9 inhibitors. In addition, we are also proposing two predictive markers of chemoresistance-BRD4 and pCDK9.

Spatial variability and hydro/geochemical profiling of the elemental composition of mineral deposits and drip water from caves using unsupervised chemometric modelling

Caves are complex systems characterized by high variability in trace element signatures that simple geochemical analysis cannot detect since useful information hidden in the dataset may be lost. Sufficiently robust unsupervised statistical approaches may provide these significant signatures for cave hydro/geochemical profiling. The present study focused primarily on quantifying the relevant contributions of elements and their relationships to the variability of the hydro/geochemical profiles of speleothems, sediments and drip water within a cave using Principal Component Analysis (PCA) after Varimax rotation and two-way joining analysis as a clustering method. This prospective study was conducted on the Urșilor (Bears') show cave (Romania). The contents of Ca, Mg, Sr, Al, P, S, Fe and Zn in the mineral deposits were determined via X-ray fluorescence, while the content of these elements in drip water was determined via inductively coupled plasma–optical emission/mass spectrometry. The contents of HCO3−, Cl−, F−, NO3−, and SO42−; pH; electrical conductivity; and organic and inorganic carbon fractions were also determined. In the case of speleothems, the determinations were performed on randomly selected spots, reflecting the composition at various growth times. The PCA revealed that the geochemical profile of speleothems can be described by four principal components (PCs), represented by 71% for stalactites and 82/92% by three PCs for stalagmites/sediments. The strong signatures of Ca, Mg/Ca, K, and detrital elements (Al, Si, P, S) in stalagmites/sediments in proportions of 41/46%; K, Fe and Zn 30/32%; and Sr and Sr/Ca 11/15% were retained by PCA. The geochemical profile of the stalactites was described by Mg (35%), P, Zn, and Sr (21%); Al and Si (15%); and S, Ca and Mg/Ca (10%). Reducing the dimensionality of the data matrix to alkaline earth elements, two PCs described 95% of the mineral deposits, including the strong signatures of Mg/Ca and Sr/Ca, exceeding 50% of the variability in the first PC. Stalactites and stalagmites were primarily grouped based on their geochemical profile and less so on location, yielding two clusters/four subclusters of stalagmites. The PCA plot did not show a separation between stalactites and stalagmites, as their geochemical profiles differ significantly only in terms of Fe concentration. The hydrochemical profile of drip water was described by 4 PCs at a percentage of 95%: (i) alkaline elements, alkaline earth elements, anions and organic carbon and (ii) trace elements and DOC. The profile of Ca2+–HCO3− imprint drip water was described by two PCs at proportions of 66% (Ca, Mg, Na, K, Mg/Ca, Sr/Ca, Ba/Ca ratios, HCO3− and organic carbon) and 74% by trace elements (Co, Ni, Ti, Fe, Mn, V and Si). The transition trace elements have very complex chemical behaviour and appear in drip water as Ca-/Si-rich inorganic/organic colloids and simple ions. Although complementary to the PCA, the two-way joining analysis in a heatmap did not offer relevant information in the description of the hydro/geochemical profile of the karst system compared to PCA. A study of a farmed calcite sample highlighted its difference in composition compared with stalagmites in terms of Mg, Si, K, Zn, Sr and Sr/Ca. Future development could include the application of PCA to seasonally collected farmed calcite and drip water samples to obtain hydro/geochemical profiles of stalagmites in the making to determine the seasonal leaching of metals from bedrock/soil by drip water, inclusion in stalagmites, and seasonal growth. The practical significance of this paper for trace element research is of great concern because it allows these recorded indicators to be connected to the ancient climate and environment of stalagmites.

Simplification of the pretreatment method for phosphate oxygen isotope measurement in phosphogypsum leachate

The stacking of phosphogypsum has caused considerable phosphorus pollution in water bodies near phosphogypsum yards through surface runoff and underground infiltration. The phosphate oxygen isotope (δ18Op) tracing method has served as a valuable tool for tracing phosphorus pollution in water. However, the existing δ18Op enrichment and purification methods are complex, costly, and inefficient for phosphate recovery, particularly for phosphogypsum leachate with complex compositions. Herein, a simplified and optimized pretreatment method for δ18Op measurement in phosphogypsum leachate was developed. Zirconium/polyvinyl alcohol (Zr/PVA) gel beads showed good selectivity for phosphate enrichment from water at different initial phosphate concentrations with appropriate Zr/PVA dosage. The optimal enrichment pH value was <7, and the concentrated phosphate on the Zr/PVA gel beads could be effectively eluted in an alkaline environment. Compared with the traditional Fe or Mg coprecipitation enrichment methods, impurities in the solution showed no obvious adverse effects on the phosphate enrichment process. Further, the phosphate solution eluted from the Zr/PVA gel beads was purified by a simple adjustment of the pH instead of cation exchange in the traditional purification process. Magnesium ions in the solution could be completely removed when the pH ranged from 3.17 to 6.15, and the phosphate recovery rate could reach 98.66% when the eluent pH was 5.02. Fourier-transform infrared spectroscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy revealed that similar to traditional pretreatment method, the proposed method can obtain high-purity Ag3PO4 solids for δ18OP measurement and no isotope fractionation of δ18OP was observed. Therefore, this study provides a promising and reliable pretreatment method for δ18OP measurement, especially in complex phosphogypsum leachate.

Continuous flow upgrading of lignin pyrolysis oils to drop-in bio-hydrocarbon fuels over noble metal catalysts

Although there are many studies on the noble metal-based catalysts for the hydrodeoxygenation (HDO) of lignin model compounds such as phenols, HDO studies on lignin biomass pyrolysis oil are relatively scarce. Owing to its complex composition (i.e., a mixture of phenolic monomers and oligomers), the activity and stability of the catalysts for the HDO of pyrolysis oil are significantly different from those for the model compounds. In this study, the catalytic performances of typical HDO catalysts, that is, Ru, Pd, Ru-Re supported on carbon, and the effects of process parameters such as solvent, temperature, and space velocity were investigated for the real lignin pyrolysis oils in a continuous-flow trickle bed reactor system for the first time. We demonstrated that proper tuning of catalyst composition and process parameters allows for producing the deoxygenated hydrocarbon mixtures which can be used for gasoline, jet fuel, and diesel fuels. Specifically, activated carbon promoted the HDO of lignin oil more effectively than acidic supports like HZSM-5 and TiO2 due to the weak adsorption of phenolic molecules. Among the different metals, Ru-Re supported on carbon exhibited the highest deoxygenation activity due to the synergy of the two metals. Tetrahydrofuran was the best solvent for lignin oil processing due to its high solubility and inertness to other side reactions (e.g., excess alkylation with ethanol solvent). The use of low space velocity of 0.2 h−1 and intermediate temperature of 350 °C resulted in the highest yield of the upgrade oil (∼25 wt%) simultaneously with the high level of deoxygenation (O/C < 0.04), mainly consisting of branched cycloalkanes. The causes of the catalyst deactivation and regeneration process are also discussed to provide practical significance.

The first identification of composite paints with proteinaceous binder in Upper Palaeolithic (31–23 ka) organic decorations

Research of coloring pigments and binding compounds from the Upper Palaeolithic (UP), including on portable art objects such as personal ornaments, provides new insights into social and cultural aspects of human history. However, we lack a comprehensive study of the composite pigment mixtures and binding materials that were produced intentionally and used for coloration. The study of several personal ornaments from the UP layers dated 31–23 ka calBP in Mezmaiskaya Cave, North Caucasus (Russia), shows that UP paints have a complex chemical composition. Using ATR–FTIR and SEM–EDS, we have identified that for coloring organic personal decorations UP humans used composite paint mixtures produced from organic (bitumen) and inorganic (red bolus/kaolin) natural pigments. Also, we firstly identified that UP humans applied a proteinaceous binder, likely representing a kind of the gelatine type animal glue, which they intentionally produced from animal origin materials using boiling. This is the oldest evidence of boiling placing its origin at about 30 ka within the late UP and linking this innovation to the need of producing organic binding material for dyeing rather than with the food preparation.

A closed-loop strategy for on-site production of saccharolytic enzymes for lignocellulose biorefinery using internal lignocellulosic hydrolysates

The cost-effective production of lignocellulose-saccharolytic enzymes is crucial for the bioconversion of plant biomass into fuels and chemicals. The integrated mode for producing these enzymes using lignocellulosic feedstocks as natural inducers has a cost advantage; however, enzyme production level is limited because of the solid-state and complex composition of the raw materials. This study aimed to establish an innovative process for the integrated production of lignocellulolytic enzymes using lignocellulosic hydrolysate as the carbon source. The cellulase-producing workhorse Trichoderma reesei was reprogrammed by combinatorial engineering of transcription factors and the introduction of heterologous β-glucosidases. This enabled inducer-independent production of a complete lignocellulose-saccharolytic enzyme cocktail using lignocellulose-derived monosaccharides as sole carbon source. Via continuous feeding of the enzymatic hydrolysate of pretreated corn stover, crude enzymes with filter paper enzyme activity of 60.4 U/ml and β-glucosidase activity of 503 U/ml were produced. Crude fermentation broth can be used directly to prepare hydrolysates, enabling nex-round enzyme production by recycling 3.1% of the hydrolysate. These results demonstrate a closed-loop strategy for integrated enzyme production using internally produced lignocellulosic sugars from biorefinery plants.

(General Student Poster Award Winner, 3rd Place) Corrosion Electrochemistry in Molten Flinak Salts

An existing knowledge gap in the field of molten salt (MS) corrosion is the lack of in situ, diagnostical and instantaneous measurements of the underlying corrosion system. Numerous investigations comparing the corrosion behavior of commercial alloys with complex microstructures and compositions in molten fluoride salts have been conducted during the past five years. A few of these have been expanded from exposure studies to those using electrochemical methods[1,2]. In essence, electrochemical techniques offer an in situ and diagnostical way to analyze the corrosion behavior of potential materials in real-time, either in open-circuit (static immersion) or polarized conditions. Investigations on MS corrosion have found few mechanistic insights that elucidate the fundamentals of electrode reactions and characteristics of the electrode-salt interface. However, fate of elements oxidized are not tracked. Nonetheless can be difficult to understand the electrochemical corrosion behavior of structural alloys in non-aqueous, aggressive media, such as molten LiF-NaF-KF (FLiNaK) salts, as they may be influenced by a wide range of parameters (such as microstructure, impurity, and potential).Understanding the mechanism of an alloy's most susceptible alloying constituent's dissolution and describing the rate-determining steps (RDS) of this process using the principles of thermodynamics, kinetics, and electrochemistry are fundamental initial steps in understanding the complexities of alloy corrosion. Chromium (Cr) is frequently referred to in molten fluorides research as an essential yet harmful alloying element in candidate molten salt reactor structural alloys (i.e.Ni-based superalloys and stainless steels) due to its high thermodynamic driving force to dissolve relative to other alloying elements. Because of that Cr is a crucial material for research because it serves as the basis for work on Fe-Cr, Ni-Cr, and Fe-Ni-Cr alloys as well as other alloys. However, published research does not consistently describe the mechanism relating to Cr corrosion in FLiNaK.The objective of this work was to explore the electrochemical corrosion behavior of pure Cr in molten FLiNaK salts at 600oC using electrochemical methods. In this study, we describe and clarify the regimes of Cr corrosion in FLiNaK at 600 oC that are potential-dependent, rate-limiting charge-transfer and mass-transport regulated.A range of measurements based on electrochemistry and material characterization, such as linear, cyclic, and potentiostatic polarization techniques, is presented. A key finding in this work was the attempt to establish a connection between the reactivity of Cr in an aggressive, non-aqueous electrolyte such as molten FLiNaK to electrochemical potentials and corrosion morphology predicted thermodynamically. It was found, that the corrosion mechanism of Cr in FLiNaK was dependent upon mixed potentials established by the anodic Cr/Cr(II) and/or Cr(II) /Cr(III) oxidations coupled with cathodic reactions by multiple oxidizer candidates whose predominance is a function of salt impurity level and Cr exposure times. Results suggest that the early stage of Cr dissolution is regulated by charge-transfer (or activation-controlled) in FLiNaK at 600oC. This type of mechanism can occur at low overpotential (i.e. lower driving force) and can be interrupted by the oversaturation of Cr at the surface. Its presence may be eliminated if the salt film is present. The electrochemical potential in which mass transport regime is rate-limiting falls within the phase stability field where CrF6 3- species dominates, and leading to the formation of a K3CrF6 salt film. The post-exposure SEM analysis revealed that Cr dissolution in this regime involves volume transport within each grain, resulting in the revelation of surface facets containing crystallographic features of cubic crystals.The application of electrochemistry enables a more straightforward way to identify potential RDS that control the rate of Cr corrosion and offers a temporal description of the corrosion mechanism. Such fundamental understanding, especially on the nature of cathodic and anodic reactions of Cr, can provide a baseline to understand the corrosion mechanism of complex alloys. The post-corrosion microstructure investigation, the XRD of the solidified salt combination, and the thermodynamic analysis of the stable phases present in each corrosion regime all corroborated these conclusions. Acknowledgments Research is primarily supported as part of the fundamental understanding of transport under reactor extremes (FUTURE), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences. Wang, Y. L., et al. Corrosion Science 109, 43–49 (2016).Chan, H.L., et al. NPJ Materials Degradation 6(1), 46 (2022).

Complexity of the effects of pre-fermentation oxygenation, skin contact and use of pectolytic enzymes in white winemaking as revealed by comprehensive proteomics and volatilomics analysis

Ion exchange chromatography and SDS-PAGE followed by identification by MALDI-TOF/TOF, and two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-TOF-MS) were used for comprehensive proteomics and volatilomics evaluation of the effects of pre-fermentative oxygenation, skin contact and use of pectolytic enzymes in production of Malvazija istarska white wine, respectively. Many protein species and an unprecedented number of volatiles have been identified and (semi)quantified, revealing high complexity of the observed effects. Compared to a standard control wine, oxygenation treatment modulated the protein composition and resulted with a volatilome characterized by decreased levels of several important volatiles. Skin contact treatments, especially in combination with pectolytic enzymes, significantly increased the levels of a large number of proteins, but were also deprived of particular protein species found in other wines. Wines obtained by skin contact with exogenous enzymes exhibited the most complex volatile composition with increased levels of many key monoterpenoids, alcohols and esters.

Fabrication of Faceted Metal Nanocrystal Electrodes By Solid-State Dewetting

Electrochemical reactions are electrode-structure sensitive and hence microstructural properties of the (electro)-catalysts such as size, shape, exposed facets, and grain boundaries, among others, strongly affect the activity, selectivity, and stability.1, 2 Conventional methods based mainly on wet-chemistry have been widely adopted to synthesize nanocrystal (NC) electrocatalysts, and proved suitable to control their features. However, these methods require several synthesis steps, which increase the production time and complexity, and resulting particles often feature a complex composition (due to impurities such as ligands or templating agents) and suffer from durability issues, due e.g. to particle detachment from the substrates.We explore solid-state dewetting (SSD) as an alternative way to produce metal nanocrystal electrocatalysts while overcoming various challenges intrinsic of conventional approaches.3, 4 Dewetting is the heat induced agglomeration of thin metal films into particles. Taking Pt as a case study, we have investigated the effect of various SSD parameters such as metal film thickness, substrate crystallographic features, and dewetting conditions (time/temperature/atmosphere) on the physicochemical properties of the resulting dewetted metal NCs. Under optimized conditions, dewetting forms monodispersed faceted Pt nanocrystals of tunable size. Low- or high-index facets can be designed (as shown in the figure below) by tuning the substrate orientation and dewetting conditions (e.g., T, dewetting gas). In general, dewetted Pt NCs show higher (ESCA-normalized) activity towards hydrogen evolution reaction (HER) compared to Pt thin films, and their mass activity is comparable to the state-of-the-art Pt/C. The talk will delve into correlations between microstructure (grain size, shape and facets etc.) and the electrochemical performance of dewetted NCs.From a general point of view, dewetted NCs show intriguing electrochemical and mechanical properties, and hence dewetting appears to be a promising approach for preparing active and robust nanostructured (electro)-catalysts for various applications. In ongoing work, we investigate dewetting to deposit catalysts on gas diffusion layer (GDL) electrodes and test their performance in PEM lab-scale electrolyzers. Figure 1

Inlet baffle structural optimization and reforming performance of exhaust gas-fuel reformer for marine LNG engine

The structural and boundary conditions are pivotal factors influencing the performance of the reformer. However, previous research primarily relied on tailored theoretical boundary conditions specific to the research requirements, often conducted in low airspeed conditions ranging from 700 ℃ to 1000 ℃. There is a lack of research focused on the complex and dynamic process of reforming hydrogen production process in reformers that handle exhaust gas components with high flow rates, high dilution, complex compositions, and low to medium temperatures (300 °C–600 °C) as boundary conditions. The objective of this study is to optimize the structure of the reformation reactor while exploring its hydrogen reforming characteristics. Therefore, this study focused on the simulation-based optimization design of an EGR reformer for marine natural gas engines. A comprehensive model was developed by coupling fluid flow, heat transfer, and surface reactions on a nickel-based catalyst. The accuracy of the model was validated through experimental data from a single-tube fixed-bed catalytic reforming experiment. The results highlighted the importance of the reformer design, with the optimal configuration incorporating two baffle plates positioned at angles of 15° and 35°. This design achieved the most uniform flow field and minimal pressure drop among the six investigated configurations. Furthermore, the study emphasized the significance of reforming gas composition in achieving high performance. The optimal reforming gas composition was found to have an M/O value of approximately 2 and an S/M value of approximately 1. This resulted in an outlet hydrogen concentration of approximately 18.8%, hydrogen yield of approximately 46.1%, methane conversion rate of approximately 66.2%, and an energy efficiency of 71%. It was observed that increasing the EGR rate led to a decrease in performance indicators, with a more pronounced effect observed at an M/O value of 1. This study provides valuable insights into the performance optimization of EGR reformers for marine natural gas engines. The findings offer guidance on selecting operational parameters to enhance efficiency and hydrogen production.

Customized triphasic cartilage composite scaffold simulating hypoxic microenvironment for osteochondral regeneration

The regeneration of the osteochondral complex in situ presents a significant challenge. The inherent hypoxic microenvironment of cartilage plays a critical role in facilitating osteochondral repair. The successful regeneration of the osteochondral complex necessitates the utilization of materials and structures that closely mimic its composition. In this study, carboxymethyl chitosan (CCS), oxidized hyaluronic acid (OHA), and tannic acid (Ta) were employed to fabricate an injectable and self-healing hydrogel (Ta@gel). The incorporation of Ta within the hydrogel network enables preferential oxidation, thereby creating an anoxic microenvironment within the hydrogel. Bone marrow-derived mesenchymal stem cells (BMSCs) were encapsulated within microspheres composed of methacrylic anhydride gelatin (GelMA). These microspheres were subsequently loaded into a Ta@gel. The resulting bionic hydrogel composite was then combined with a three-dimensional (3D) printed hydroxyapatite (HAp) scaffold coated with poly-l-lysine (PLL). This combination resulted in the formation of a bionic three-layer composite structure (HAp@PLL + Ta@gel + GelMA@BMSCs) that closely resembles the complex composition and structure of natural osteochondral complex. The efficacy of this customized triphasic composite scaffold in promoting osteochondral complex regeneration has been demonstrated in vitro and in vivo. Consequently, this study provided a new sight for inducing the in situ regeneration of cartilage.

Multi-Scalar Drivers of Residential Vegetation Changes in Metropolitan Phoenix, Arizona.

In the arid southwestern U.S., urban greening strategies have been promoted to alleviate ecosystem disservices associated with lawns, including the adoption of xeric yards with desert-adapted floras and gravel groundcover and wildlife-friendly yards with complex vegetation structure and composition. Scant studies have investigated the extent of different vegetation changes in urban greening practices and the complexity of associated human drivers. We addressed this gap by analyzing survey data from two survey periods (2017 and 2021) to answer the following questions: to what extent have residents from metropolitan Phoenix made different vegetation changes in their yards over the last decade, and how do multi-scalar human drivers affect different vegetation changes? We found a sustainable trajectory for residential vegetation changes in Phoenix since mid-2010s, with declining additions of grass and increases in trees and desert plants across residential neighborhoods. Esthetics was an influential driver of both tree planting and native gardening. Additionally, tree planting was associated with anthropocentric values (i.e., low-maintenance needs), while desert plant additions reflected the appreciation of nature (i.e., attitudes towards the desert) and environmental concerns (i.e., supporting wildlife). Institutions such as local government programs might shape residents' vegetation choices, as tree planting differed among municipalities. We also found counterintuitive influences of residential tenure controls on landscaping decisions. Specifically, renters were more likely to add yard trees compared to homeowners. Our results inform landscape sustainability by identifying potential pathways to residential yard changes that offer a multitude of services while being appreciated and maintained by residents.

Narrative structure of Boris Zhytkov’s novel “Viktor Vavich”

The purpose of this article is to analyze the narrative structure of B. Zhytkov's novel «Viktor Vavіch» (1926-1931, published in 1999). The relevance of the study is due to the fact that narratological analysis is a promising area of modern philological science, but the narrative characteristics of B. Zhytkov's novel are almost never revealed in literary studies of the text. The author proposes to use the model of communicative instances and points of view of W. Schmid, to clarify the relationship between the narrative structure and the novel's problems, narrative factors of characterization, etc. It is proved that the novel is based on a complex polyperceptual composition, in which the narrator's colorful figure is almost not revealed, who remains as if outside the text, allowing his characters to present their worldview almost independently. The author examines the figure of the titular character Viktor Vavich and how his image is constructed by narrative means. It is proved that the structure of consciousness represented by Viktor Vavich is dual and incorporates both the hero's own consciousness and the imaginary image of the external other constructed by him, which subjects him to critical evaluation. This duality of self-perception is characteristic of several characters in the text, but only in the case of Vavich does it become a psychological dominant that ultimately destroys his personality and leads him to decline and death. It has been shown that despite the polyperceptual composition and the unidentified narrator, there is a monologic organizing principle in the text, which is manifested through the functioning of a rather uniform and stable motivic system that is realized through different perceptual instances. In this way, the text forms an imaginary dialogue between two instances: a monological intention that exists in the categories of its own ideology and a polyphony of consciousnesses that do not have a colored narrator figure to give them any ideological assessment.