Search Results (188)

Hydrogen prereduction of two manganese ores fines was investigated under varied operating conditions in a fluidized bed. The manganese ores used in this study are the Zambian ore and the South African Nchwaneng ore from the Kalahari region. The samples were milled and sized before they were characterized with regard to sphericity, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) chemical analyses, X-ray diffraction (XRD) analyses and Scanning Electrons Microscope (SEM) analyses. Prereduction experiments were conducted in a laboratory scale fluidized bed with the parameters of interest being minimum fluidization velocity, terminal velocity, elutriation, average bed voidage, residence time, temperature, intrinsic ore properties and cohesive adhesion. Experiments for the determination of fluidization velocity and terminal velocity were conducted at both ambient temperature and elevated temperature ($500 °$C, $550 °$C, $600 °$C, $700 °$C, $800 °$C and $900 °$C), and for varied sample masses (100 g, 300 g and 700 g) and varied particle-size ranges (200–$300 \mathrm{\mu }$m, 300–$425 \mathrm{\mu }$m, 425–$500 \mathrm{\mu }$m and 500–$600 \mathrm{\mu }$m). The experimentally observed minimum fluidization velocities for particles size groupings of [+106–$200 \mathrm{\mu }$m], [+200–$300 \mathrm{\mu }$m], [+300–$425 \mathrm{\mu }$m], [+425–$500 \mathrm{\mu }$m] and [+500–$600 \mathrm{\mu }$m] as well as the mix (20 wt% of each) was comparable with the theoretical minimum fluidization velocity. The fluidized bed was heated to a desired temperature at a rate of $10 °$C/min under argon whilst logging the pressure drop across the bed with increasing temperature. The convectional cooling during the introduction of cold hydrogen as well as the net energy of endothermic and exothermic chemical reactions were observed to result in a temperature drop in the order of 100 to $250 °$C. Thermal mineral transformation under argon was observed to yield iron manganese oxide in the order of 15 to 30 wt/wt%. Prereduction was conducted using hydrogen gas at a desired temperature and terminal velocity. Reduction extent was observed to increase with the increasing temperature and residence time. Increasing reduction temperature beyond $700 °$C was not observed to improve reduction, whereas longer residence time (of up to 40 min) was observed to favor the formation of iron manganese oxide, iron manganese and manganosite. For hydrogen prereduction experiment conducted at $900 °$C, the reactor was observed to be brittle after the experiment. Cohesive adhesion was observed to be more pronounced at $900 °$C. Full article

‘Dianheyou615’ (DHY615) is an elite Dian (D1)-type hybrid japonica rice variety, renowned for its high yield, exceptional grain quality, and unique adaptability to both irrigated and rainfed conditions in the Yungui Plateau of southwestern China. However, the genetic mechanisms underlying the agronomic performance of the D1-type hybrid japonica rice remain unclear. In this study, a comprehensive analysis of ‘DHY615’’s agronomic performance, genetic genealogy, and molecular genetic foundation was conducted to dissect its desirable traits for upland rainfed cultivation across diverse ecological environments. The main findings indicate that ‘DHY615’ possesses 6432 heterozygous SNPs, with 57.48% and 14.43% located in the promoter and coding regions, respectively, potentially affecting key phenotypic traits. High-impact SNPs variants and numerous well-known functional genes were identified, such as OsAAP6, GS3, Sd1, Rf1, BADH2, BPh14, Rymv1, OsFRO1, NRT1.1B, SKC1, OsNCED2, and qUVR-10, which are likely linked to traits including plant architecture, grain yield, grain quality, and resistance to various biotic and abiotic stresses (e.g., disease, cold, drought, salt, high iron, and high UV radiation). Notably, ‘Nan615’ harbors a greater number of functional allele variants compared to ‘H479A’, which potentially explaining its superior grain yield and remarkable adaptability. This study offers novel and valuable insights into the molecular genetic foundation of the plateau D1-type hybrid japonica rice, underscoring its potential for sustainable rice production across diverse ecological zones, especially with its unparalleled high-altitude adaptability to rainfed upland planting. Full article

Red wines produced with interspecific grape cultivars tend to have low tannin concentration and are therefore unbalanced. Extended maceration (EM) is a common winemaking technique which can promote the extraction of tannins from grape skins and seeds. The goal of this study was to evaluate the effect of EM on the tannin concentration, color intensity and other chemical properties of red wines made from cold-hardy grape cultivars. The wines were made from two cold-hardy interspecific grape cultivars (Marquette, and Petite Pearl) for either 7 days (control) or 21 days (EM) before pressing. Chemical analysis of the wines was conducted to determine their tannin concentration and color parameters at different stages of the process and after 14 months of aging. EM resulted in an improvement in the iron-reactive phenolic content of Marquette red wines (from 582 to 969 mg/L at bottling in control and EM wines, respectively), but no significant improvement in tannin content. The hue of Petite Pearl wines increased following EM only at pressing, and color intensity of those wines decreased at pressing and bottling by 43% and 52%, respectively. This study was the first one conducted on non-Vitis vinifera grapes which showed a lack of impact of EM on the phenolics and tannin concentration in the red wines made in 2022. Full article

The aim of this study was to examine cold-pressed oils available on the Polish market derived from different plants and manufacturers in the context of their biological activity, including micro- and macroelements, antioxidant properties, antimicrobial activity, and selected effects on eukaryotic cells. In total, 76 oil samples of 34 selected oil types from nine Polish companies (five commercial and four amateur) were tested. The content of macro- and micronutrients was assessed using ICP-OES, the level of fatty acid unsaturation was examined using Fourier transform infrared spectroscopy (FTIR), and total antioxidant potential (TAP) was assessed using the DPPH method. The antimicrobial activity of the selected oils against Gram-positive and Gram-negative bacteria, as well as fungi, representing both pathogens and human microbiota, was tested using the broth microdilution method. The MTT reduction assay was used to exclude the cytotoxic effect of the oils on the human fibroblast line HFF-1. It has been concluded that the composition of cold-pressed oils varied significantly depending on the plant used and the manufacturer. The total content of the elements tested ranged from 172.91 mg/kg in Helianthus annuus oil to 1580.73 mg/kg in Silybum marianum oil. The iron concentration limits were exceeded in 10 oils, the copper concentration limits were exceeded in 34 oils, and the lead concentration limits were exceeded in 18 oils. At least one of these elements was exceeded in 40 oils (53% of the tested samples), which is why testing the concentration of elements should be a standard procedure for assessing the quality of cold-pressed oils. There was no statistically significant correlation between the content of any macro- and microelements and TAP. While TAP was strongly correlated with the spectral unsaturation index of the oils, this relationship can be used to develop a simple and rapid assessment of oils quality. The strongest antioxidant activity (over 90%) was observed for Nigella sativa oils. Interestingly, among all the tested oils, only these from Nigella sativa L., whatever the producer, possessed also strong antimicrobial activity. None of the tested oils showed cytotoxicity against eukaryotic cells, so the cold-pressed oils can be considered safe. Full article

Furnas volcano, one of the three active central volcanoes of São Miguel (the Azores archipelago), hosts mineral waters with significant special variations, divided into hyperthermal (89.4–95.4 °C), thermal (29.9–70.0 °C), and cold (14.2–21.4 °C) waters. Groundwaters are classified as Na-HCO₃, with a neutral to slightly acidic pH, except one SO₄-Na acidic sample. The major elements are primarily influenced by rock leaching and volcanic input, patterns also reflected in the trace elements, including the rare earth elements. The major cations, along with lithium, iron, aluminum, rubidium, and strontium, indicate the influence of water–rock interactions. Some samples depict a higher influence in this input, shown by the similar REE behavior between them and the local rock behavior. The volcanic input is distinguished into two environments: an acid sulfate boiling pool, formed by steam heating, and neutral HCO₃-Cl waters, where bicarbonate-rich waters mix with a neutral chloride fluid from a deep reservoir. The deeper reservoir also provides boron, arsenic, antimony, and tungsten, also seemingly associated with a positive spike in europium due to rock dissolution at temperatures above 250 °C or a reducing environment. This interpretation is corroborated by the stability of the strontium isotopes between samples. Full article

This study examines the impact of monitoring, reporting, and verification (MRV) system indicators on the costs associated with the emissions trading system (ETS) of the maritime sector in the European Union. Since maritime transport has recently been incorporated into the ETS, it becomes essential to understand how different operational and environmental factors affect the economic burden of shipping companies and port competitiveness. To this end, a model based on Bayesian networks is used to analyse the interdependencies between key variables, facilitating the identification of the most influential factors in the determination of the costs of the ETS. The results show that fuel efficiency and CO₂ emissions in port are decisive in the configuration of costs. In particular, it was identified that emissions during the stay in port have a greater weight than expected, which suggests that strategies such as the use of electrical connections in port (cold ironing) may be key to mitigating costs. Likewise, navigation patterns and traffic regionalisation show a strong correlation with ETS exposure, which could lead to adjustments in maritime routes. This probabilistic model offers a valuable tool for strategic decision-making in the maritime sector, benefiting shipping companies, port operators, and policymakers. However, future research could integrate new technologies and regulatory scenarios to improve the accuracy of the analysis and anticipate changes in the ETS cost structure. Full article

Industrialization trial production of high permeability (Hi-B) steel was carried out by “one cold rolled + decarburization and nitridation technologies”. The finished product reached the level of 23Q100 with an average grain size of 5.47 cm, magnetic flux density B₈ of 1.902T, and the iron loss P_1.7/50 of 0.975 W/Kg. The evolution law of the microstructure and texture under different processes was analyzed with the help of OM, EBSD, and XRD. The results showed that the microstructure of the hot rolled plate was equiaxed crystals in the surface layer, a mixture of recrystallization grains and banded fiber in the quarter of the thickness layer, and banded fiber in the center layer. The texture gradient of the hot rolled plate from the surface layer to the center layer was {112}<111> + {110}<114> → {441}<014> → {001}~{111}<110>. The texture of the normalized plate was in major {110}<113> in the surface layer, diffuse α-fiber texture and {441}<014> in the quarter of the thickness layer, and sharp α texture {001}~{111}<110> in the center layer. The texture of the cold-rolled sheet was concentrated in {001}~{332}<110>. The average grain size of the decarburizing and nitriding sheet was 26.4 μm, and the texture of the first recrystallization is sharp α*-fiber and weak {111}<112>. The finished product has a sharp single Goss texture. For Hi-B steel, the Goss secondary nucleus originated from the surface layer to 1/4 layer of the hot rolled plate and reached the highest content of 11.5% in the quarter of the thickness. The content of the Goss texture decreased with the subsequent normalization and cold rolling, then the Goss grains nucleated again during the decarburization annealing and high temperature annealing processes. Full article

The Lhasa River, as one of the major rivers on the Tibetan Plateau, is of great value for the study of climate and environmental changes on the Tibetan Plateau. In this paper, the grain size and the mineralogical and geochemical characteristics of the sediments from the Lhasa River were investigated. The results show the following: (1) The average grain size of the Lhasa River sediments is coarse (65.5% sand, 23.6% silt), and the sorting is overall poor; the skewness is mostly positive, and the kurtosis is wide, which reflects the obvious characteristics of river sand deposition. (2) The mineral composition of the Lhasa River sediments is dominated by quartz (38.4%), feldspar, and plagioclase feldspar, followed by clay minerals, and the content of carbonate minerals is relatively low; the content of clay minerals in the illite content is as high as 83.3%, while the chlorite content is slightly higher than kaolinite, and smectite content is very low. The chemical index of illite is less than 0.4, indicating that illite is mainly iron-rich magnesium illite. (3) The value of the chemical weathering index (CIA) of the sediments is low, implying that the sediments are in a weak–moderate chemical weathering state and dominated by physical weathering. Comprehensive analyses further revealed that the weathering process of the sediments in the Lhasa River was influenced by both climate and lithology, i.e., sediment composition is influenced not only by chemical weathering in a dry, cold climate but also by physical weathering of granites exposed over large areas. The results of this study can provide scientific references for further in-depth research on the environmental and climatic effects of the Tibetan Plateau. Full article

Polar areas are not exempt from anthropogenic pollution. Heavy metals have been detected in Arctic and Antarctic lakes. Bacteria, at the base of the food web, can possess the ability to adsorb or immobilize heavy metals in the environment and reduce their concentration in the water column. However, several gaps exist in our knowledge of bacterial tolerance to heavy metals in polar systems, especially in lakes. Heavy metal-tolerant bacteria from polar lacustrine sediments were selectively enriched and subsequently isolated and identified. Their growth at increasing concentrations of different heavy metals (iron, copper, and mercury) was evaluated. Selected isolates were tested for sequestration of iron and mercury. A total of 101 bacterial isolates were obtained from metal-enriched cultures. Gammaproteobacteria and Actinomycetota isolates were most abundant in Arctic and Antarctic enrichments, respectively. Iron was the most tolerated metal. Mercury and iron were sequestered by the isolates by up to 14.2 and 13.4%, respectively. The results from this study contribute to our understanding of heavy metal-tolerant bacteria from cold environments and their potential use in biotechnological applications. Full article

Rivers in plateau regions are more vulnerable to human activities and climate change than those in plains due to cold climate and high altitude. Studying the temporal and spatial distribution of phosphorus against the backdrop of climate warming and human activities is of great significance for the protection of the ecological environment of plateau rivers. This study focuses on the Yarlung Zangbo River, one of the highest-altitude rivers in the world, analyzing the different forms of phosphorus and total dissolved organic carbon (TOC) concentration and distribution characteristics in sediments and sediment–water interfaces at different time and spatial scales. The analysis indicators include total phosphorus (TP) and dissolved total phosphorus (DTP) in the water body; ammonium chloride-extractable phosphorus (NH₄Cl-P), iron-bound phosphorus (Fe-P), calcium-bound phosphorus (Ca-P), aluminum-bound phosphorus (Al-P), organic phosphorus (OP), and TOC concentration and distribution in sediments. The results showed that the upstream and downstream sections of the Yarlung Zangbo River have relatively good water quality, while the middle stream section, affected by human activities, has higher phosphorus and TOC content in the water body. The phosphorus in the sediments is mainly in the form of Ca-P, indicating that the primary natural phosphorus input is through the disintegration of salts. During the freeze–thaw cycle, the organic matter in the sediments affects the phosphorus content in the water through adsorption and release. Climate warming is expected to increase the phosphorus load in the Yarlung Zangbo River. Comparative studies between plateau rivers and plains rivers have revealed that exogenous particulate phosphorus and endogenous phosphorus converted with the facilitation of organic matter are the main sources of eutrophication risk in plateau rivers. This study unveils the temporal and spatial distribution characteristics of phosphorus and TOC in the Yarlung Zangbo River, and discusses the mechanisms affecting phosphorus concentrations in key plateau river nutrient elements, providing scientific support for the protection of the fragile ecological environment of plateau river ecosystems. Full article

Lipoxygenase (LOX) is a dioxygenase that contains non-heme iron and plays a crucial role in regulating plant growth and development, signal transduction, and responses to both biotic and abiotic stresses. In this study, we identified 24 CsLOXs from the pan-genome of 12 cucumber (Cucumis sativus L.) accessions, with most CsLOX proteins exhibiting amino acid variations. To elucidate their functions, we examined the phylogenetic relationships, gene structures, conserved domains, promoter cis-elements, and collinearity of the 24 CsLOXs from the newly updated genome version 4.0 of ‘Chinese Long 9930’. The results indicated that CsLOXs can be categorized into three subfamilies: 9-LOX, Type I 13-LOX, and Type II 13-LOX. Additionally, promoter analysis revealed that the promoters of CsLOXs contain various cis-elements related to stress and hormone responses. The expression of CsLOXs demonstrated tissue specificity, with each CsLOX expressed in at least one tissue, and six CsLOXs expressed across all tissues. Furthermore, in the transcriptome data of cucumber responses to heat, cold, powdery mildew (PM), downy mildew (DM), and gray mold (GM) stresses, eight, four, eight, eight, and four CsLOXs exhibited differential expression, respectively. Notably, CsLOX22 responded to heat, cold, DM, and GM stresses. Our results provided a reference for further exploring the functions of CsLOXs in cucumber. Full article

Hawthorn (Crataegus spp.), a plant widely distributed in temperate and subtropical regions, is valued for its bioactive compounds and diverse health benefits. Known for its remarkable adaptability to various environmental conditions, hawthorn thrives across different altitudes, but these environmental factors, particularly altitude, significantly influence the accumulation of its bioactive substances. This study investigates the effects of altitude on hawthorn’s nutritional, bioactive, and mineral profiles to provide insights into its cultivation and utilization. Through comprehensive analysis of 20 nutritional indicators from high- and low-altitude samples, including essential nutrients, bioactive compounds, and trace elements, multivariate analyses such as Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) revealed clear altitude-driven clustering. While primary nutritional components like dietary fiber, protein, and soluble solids exhibited stability across different altitudes, low-altitude samples showed higher levels of hypericin, quercetin, and rutin, likely due to favorable light and temperature conditions. Conversely, high-altitude samples were enriched in calcium, reflecting adaptations to cold stress and structural needs, while phosphorus content was reduced under cooler conditions. Potassium, iron, zinc, selenium, and strontium levels remained stable, indicating robust metabolic regulation. These findings confirm the significant role of altitude in shaping hawthorn’s bioactive and mineral profiles, providing essential guidance for altitude-specific cultivation practices and tailored processing strategies. By leveraging these insights, the functional and nutritional properties of hawthorn can be optimized, supporting its sustainable application in the food and health industries. Full article

In the design of a rotary-type magnetic refrigerator, a high field of a coaxial magnet is desired. Typically, a high-field design can be achieved with a small duty cycle, which might not be optimized from the viewpoint of the thermal hydraulics of a magnetic refrigerator. In this work, a numerical simulation analysis of a graded coaxial magnet designed using a COMSOL program for a rotary-type active magnetic refrigeration (AMR) system was performed. The magnet structures are based on neodymium–iron–boron permanent magnets with thin gadolinium (Gd) and gadolinium-terbium alloy (Gd-Tb) plates as AMR materials. For a rotary-type magnetic cooling system, from the thermal–hydraulic point of view, the best duty cycle of a coaxial magnet should be 50% if the magnetic field can be kept constant during the period of duty cycles. However, the simulation calculation shows a serious reduction in the magnetic field strength at higher duty cycles, resulting in lower magnetic cooling efficiency. After considering the thermos-hydraulic part, the optimized duty cycle is around 30% in the case of a temperature span of 8 K between the hot and cold ends on a rotary-type magnetic cooling system. By applying graded Gd-Tb alloy along the flow direction, the performance of magnetic refrigeration improves significantly. Compared to a pure Gd AMR system, it is demonstrated that more than three times the increase in the cooling capacity can be achieved. Full article

The purpose of this research article is to perform a greenhouse gas (GHG) impact assessment using a lifecycle analysis of a cold-ironing solution for vessels at anchorage in a retrofitted barge and a marine genset combusting biomethane in dual fuel mode. A lifecycle methodology is developed based on the 4th International Maritime Organization (IMO) GHG study. Eleven impact scenarios are evaluated in terms of CO₂ and harmful pollutants (SO_x, CO, PM₁₀, PM_2.5, NMVOC, and NO_x). Vessels operated by Petronav Ship Management Ltd are examined, specifically M/T Alexandria and M/T Astraia. The scenarios reveal CO₂ reductions of up to 21% and CO increases of up to 60% due to the combustion of biomethane in dual fuel mode, alongside SO_x reductions of up to 20% with increasing biomethane energy substitution. Particulates and NO_x decrease due to the utilization of biomethane. This article presents a pragmatic solution for cold ironing for vessels at anchorage with proven lower GHG emissions with the exception of increased CO emissions, therefore the benefits outweigh the drawbacks. Full article

Due to their biocompatibility, nontoxicity, and surface conjugation properties, nanomaterials are effective nanocarriers capable of encapsulating chemotherapeutic drugs and facilitating targeted delivery across the blood–brain barrier (BBB). Although research on nanoparticles for brain cancer treatment is still in its early stages, these systems hold great potential to revolutionize drug delivery. Glioblastoma multiforme (GBM) is one of the most common and lethal brain tumors, and its heterogeneous and aggressive nature complicates current treatments, which primarily rely on surgery. One of the significant obstacles to effective treatment is the poor penetration of drugs across the BBB. Moreover, GBM is often referred to as a “cold” tumor, characterized by an immunosuppressive tumor microenvironment (TME) and minimal immune cell infiltration, which limits the effectiveness of immunotherapies. Therefore, developing novel, more effective treatments is critical to improving the survival rate of GBM patients. Current strategies for enhancing treatment outcomes focus on the controlled, targeted delivery of chemotherapeutic agents to GBM cells across the BBB using nanoparticles. These therapies must be designed to engage specialized transport systems, allowing for efficient BBB penetration, improved therapeutic efficacy, and reduced systemic toxicity and drug degradation. Lipid and inorganic nanoparticles can enhance brain delivery while minimizing side effects. These formulations may include epitopes—small antigen fragments that bind directly to free antibodies, B cell receptors, or T cell receptors—that interact with transport systems and enable BBB crossing, thereby boosting therapeutic efficacy. Lipid-based nanoparticles (LNPs), such as liposomes, niosomes, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs), are among the most promising delivery systems due to their unique properties, including their size, surface modification capabilities, and proven biosafety. Additionally, inorganic nanoparticles such as gold nanoparticles, mesoporous silica, superparamagnetic iron oxide nanoparticles, and dendrimers offer promising alternatives. Inorganic nanoparticles (INPs) can be easily engineered, and their surfaces can be modified with various elements or biological ligands to enhance BBB penetration, targeted delivery, and biocompatibility. Strategies such as surface engineering and functionalization have been employed to ensure biocompatibility and reduce cytotoxicity, making these nanoparticles safer for clinical applications. The use of INPs in GBM treatment has shown promise in improving the efficacy of traditional therapies like chemotherapy, radiotherapy, and gene therapy, as well as advancing newer treatment strategies, including immunotherapy, photothermal and photodynamic therapies, and magnetic hyperthermia. This article reviews the latest research on lipid and inorganic nanoparticles in treating GBM, focusing on active and passive targeting approaches. Full article