Amount Of Molybdenum Research Articles

Chemical interactions at interfaces in nanoscale Mo/B4C multilayered structures

The study of chemical interactions between Mo and B4C layers in multilayer structures depending on their total thickness (d) and thickness ratio (Γ) was carried out using X-ray photoelectron spectroscopy (XPS) method. The results showed significant interactions of materials within the multilayer structures. Specifically, in the range of d from 1.8 to 3.4 nm and Γ value between 0.24 and 0.46, a complete conversion of B4C into MoBxCy was observed, while retaining some amount of molybdenum. The insertion of tungsten barrier layer to the Mo-on-B4C interface led only to insignificant reduction of component MoBxCy. Based on the data obtained by XPS, theoretical models were developed and applied to X-ray reflectometry data during fitting procedure. The application of XPS has proven to be highly effective in constructing models and obtaining numerical values when fitting reflection curves.

Extraction of molybdenum, cobalt, and nickel from acidic leach solution of molybdenum leach residue of spent hydrodesulfurization catalyst

ABSTRACT After the extraction of molybdenum from the spent HDS catalyst, a residue containing aluminum, nickel, cobalt, and a small amount of molybdenum was obtained. The simultaneous recovery of nickel, cobalt, aluminum, and residual molybdenum from molybdenum leach residue can be achieved through hydrochloric acid leaching. In the work presented herein, the extraction of molybdenum, cobalt, and nickel from the acidic leach solution of molybdenum leach residue was investigated. Trioctyl tertiary amine can selectively extract cobalt and molybdenum from the acidic leach solution, the extraction of both cobalt and molybdenum reached more than 99% after two-stage countercurrent extraction. The combination of pure water and 25% ammonia water can be utilised for the separation and extraction of cobalt and molybdenum from the loaded cobalt-molybdenum organic phase. After the extraction of cobalt and molybdenum, a synergistic extraction system comprising decyl 4-picolinate and dinonylnaphthalene sulfonic acid can be employed for nickel extraction, achieving a nickel extraction exceeding 99.70% while maintaining aluminum extraction at only 0.32% after undergoing four-stage countercurrent extraction. The nickel stripping efficiency can reach 99.50% after four-stage countercurrent stripping, using a stripping agent of 2 mol/L H2SO4.

Ultrahigh-resolution imaging of biogenic phosphorus and molybdenum in palaeoproterozoic gunflint microfossils

Phosphorus and molybdenum play important roles in the formation of microbial cell structures and specific enzymes crucial for metabolic processes. Nevertheless, questions remain about the preservation of these elements within ancient microfossils. Here, we present shape-accurate ion images capturing phosphorus and molybdenum on Palaeoproterozoic filamentous microfossils by pioneering a methodology using lateral high-resolution secondary ion mass spectrometry. Introducing electrically conductive glass for mounting isolated microfossils facilitated clearer observations with increased secondary ion yields. Phosphorus was detected along the contours of microfossils, providing direct evidence of phospholipid utilization in the cell membrane. Trace amounts of molybdenum were detected within microfossil bodies, suggesting potential remnants of molybdenum-bearing proteins, such as nitrogenase. These findings align with the hypothesized cyanobacterial origin of filamentous gunflint microfossils. Our methodology introduces a groundbreaking tool for obtaining crucial insights into the cellular evolution and metabolic pathways of microorganisms, allowing comparisons of their morphological characteristics.

Dual‐mode sensing biopolymer membrane impregnated with molybdenum for ethylene detection and monitoring of fruits

AbstractIn this study, a dual‐mode sensing biopolymer membrane employing chitosan (CS), polyvinyl alcohol (PVA), and ammonium molybdate (AM) was developed for optical and electrochemical detection of ethylene. The biopolymer composite was characterized by X‐ray diffraction (XRD), Fourier transform infra‐red (FTIR), and scanning electron microscopy (SEM).The relationship between ethylene concentration and optical/electrochemical response was investigated. XRD analysis showed enhanced ionic conduction, supported by SEM images showing uniform pore distribution within the synthesized membrane, facilitating effective gas interaction with Molybdenum. The increased FTIR peak intensities with higher amount of molybdenum in the membrane indicates enhanced molecular interactions. Applied to a microelectrode chip, the membrane exhibits a measurable electrochemical response with oxidation peak appearing in cyclic voltammogram as Molybdenum ions undergo reduction upon ethylene exposure. Colorimetric measurements, based on CIELAB values, reveals visible color shift with increasing ethylene concentrations, particularly at 10% molybdenum impregnation. Ionic conductivity and total color difference exhibit parallel variation with ethylene concentrations. X‐ray photoelectron spectroscopy confirms molybdenum oxidation state shift from +6 to +5 in the membrane upon ethylene interaction. The inexpensive colorimetric method enables direct color change visualization in practical applications. The resulting dual‐functional biopolymer membrane shows adaptability and versatility by responding to both optical and electrochemical signals.

Electrodeposition of Non-Noble High-Entropy Alloys for Effective Hydrogen Evolution Electrocatalysts

As society works towards reducing its carbon footprint, various sectors such as energy, steelmaking and fertilizer production have begun to look increasingly towards decarbonization. Hydrogen production through electrolysis, when linked to renewables (solar, wind), provides a promising low-emission alternative as an energy carrier and chemical feedstock. With the decreasing cost of said renewables, greater focus is now on the capital cost of the electrolyser, and particularly the membrane/electrode structures. Conventional Proton Exchange Membrane (PEM) electrolysers rely on the use of electrocatalysts made with expensive noble metals such as platinum, ruthenium, and palladium [1]. Anion Exchange Membrane (AEM) electrolysers present an effective means of alkaline water splitting with low carbon emissions and can effectively utilize non-noble metal electrocatalysts for the Hydrogen Evolution Reaction (HER). A novel class of materials, High-Entropy Alloys (HEAs), made of non-noble metals or with reduced noble metal content have shown great promise as active electrocatalytic materials [2]. HEAs are typically defined as metal alloys made of five or more constituent elements each comprising at least 5% of the total material [3]. Having such a large number of principal alloying elements can lead to enhanced phase stability due to an increased configurational entropy, have unique chemical clustering, and can help prevent degradation of the material in harsh environments [2]. Additionally, the large lattice parameter mismatch between constituent elements can result in a high degree of strain which can help shift electronic states in a way that is favourable to hydrogen electrocatalysis [4]. These properties along with the so called “cocktail effect,” whereby combining multiple elements can result in unexpected synergistic interactions, makes HEAs uniquely suited to electrocatalytic applications [5].In this work, we investigate the electrocatalytic performance of electrodeposited FeNiCoMoW HEAs. The goal is to combine three hyper-d transition metals with two hypo-d transition metals to alter the electronic structure and improve electrocatalytic performance. Using chronoamperometric measurements, the Tafel slopes for FeNiCoMoW HEAs electrodeposited at pH 5, 6 and 7 were determined, with the pH 5 HEA demonstrating the smallest average Tafel slope of approximately 83 mV/dec. Compared to some electrodeposited binary alloys reported on in the literature, this marks an improvement and may be the result of unexpected interactions within the compositionally complex alloy. In the FeNiCoMoW HEA, the magnitude of the Tafel slope increased in tandem with the electrochemically active surface area (ECSA) as determined by Cyclic Voltammetry (CV) which suggests that the composition may be more important for improving performance. As the pH of the electrodeposition solution increased, the amount of cobalt in the as-deposited HEA decreased while the amounts of molybdenum and tungsten remained constant. The composition of nickel and iron appeared to vary inversely, reaching a maximum and minimum respectively at pH 6. From these results it seems that maximizing cobalt content and minimizing nickel content could potentially help to improve HER performance in the FeNiCoMoW system.

Use of molybdenum in Ni 620 filler metal to influence the microstructure of brazed hot work steel

AbstractBrazing of hot work steel with nickel‐based filler metals is a widely used process for manufacturing casting tools. However, the formation of brittle phases in the joint impairs its mechanical properties. Reducing these intermetallic phases is an important aspect. Thermodynamic equilibrium calculations are used to estimate the change in melting range and apearance of intermetallic phases by adding different amounts of molybdenum to Ni 620. The filler metals are then produced and their solidus and liquidus temperatures are investigated using differential scanning calorimetry. Specimens of X37CrMoV5‐1 are then brazed in a vacuum furnace and their microstructure is analysed by scanning electron microscopy/electron dispersive spectroscopy and their hardness properties by nanoindentation. The addition of molybdenum to the Ni 620 filler metal leads to the formation of chromium molybdenum boride rich phases and reduced hardness values in brazed joints. Manipulation of Ni 620 by molybdenum helps to improve relevant properties in brazing hot work steel.

Catalytic conversion of residual raw material into biodiesel using a superior magnetic solid acid catalyst based on Zn-Fe ferrite: thermodynamic and kinetic studies.

This study investigates the potential and applicability of a novel solid magnetic catalyst constructed by incorporating molybdenum oxide (MoO3) into zinc ferrite (ZnFe2O4) to biodiesel production using Waste Frying Oil (WFO) as the residual raw material. The molybdenum amounts (5, 15, 25, 35 and 45%) present in the catalyst were studied and the catalyst demonstrated great characteristics and high acid properties, as well as superior magnetic and catalytic attributes. The one variable at time (OVAT) optimization method revealed that the application of the MoO3/ZnFe2O4 catalyst resulted in obtaining a biodiesel with 97.6% ± 0.727 conversion to fatty acid methyl esters (FAME) under the following optimized reaction conditions: temperature of 165 °C, methanol : WFO molar ratio of 40 : 1, catalyst amount of 6 wt% and reaction time of 3 h. In addition, the catalyst showed high reusability after six reaction cycles, with conversion to esters above 90%. Besides, the activation energy (E a) calculated in the kinetic study was 25.3 kJ mol-1. Moreover, the properties of the synthesized biodiesel met the standards set by the ASTM D6751 and EN 14214, which indicates the high MoO3/ZnFe2O4 potential for industrial application with low energy consumption as well as minimal negative environmental impact.

Issues Associated with Yellow Phase Formation and Other Disruptions in Japanese High-Level Waste Vitrification and Their Improvement

The Rokkasho Reprocessing Plant, located in northern Japan, includes facilities for reprocessing spent nuclear fuels and immobilizing high-level waste (HLW) into a stable-glass waste form based on borosilicate. The vitrification process consists of two large liquid-fed, joule-heated, ceramic-lined melters (LFCMs). During the active test campaigns at the Rokkasho Vitrification Facility, unstable melting performance and difficulty in glass operation were observed in the LFCM operation. The operating protocols that had been developed in the earlier full-scale mock-up testing with inactive waste simulants were found to be inadequate to manage a stable LFCM operation. We needed to understand correctly the fundamental causes for the operational difficulties experienced in the active test. First, we studied and summarized the troublesome element behaviors and disturbances in the HLW vitrification process, primarily on the LFCM. Second, we proposed an empirical model, including the transition of the phenomena that appeared in the active LFCM operation. Third, we analyzed the operating data and the trend of operation indexes to find out the fundamental causes for the unstable LFCM operation based on the results obtained in the described model. It was revealed that the presence of a significant amount of molybdenum and sulfur, together with the noble metals (NMs) Ru, Rh, and Pd in the Rokkasho HLW stream could lead to the formation of molybdate and sulfate salt phases [yellow phases (YPs)], and subsequently, the sedimentation of NMs at the bottom of the melter. The YPs may concentrate at the melter bottom and clog the pouring nozzle prior to the bottom accumulation of NM sludge, which can disrupt power deposition and cause difficulties during glass pouring operation. Based on these investigated results, we provide insights into short-term countermeasures, including numerical control of the heat balance in the melter, dilution of HLW feed with inactive waste simulants, and periodic rinsing of the bottom glass. We also provide an evaluation of their validities on the active operation through full-scale mock-up testing. However, the periodic rinsing and dilution operation produce additional glass-filled canisters and increase the total backend cost. Finally, we see a couple of important directions for future research and development. An advanced LFCM system has been developed for the long-term countermeasures to introduce recent advances in the LFCM design with YP and NM compatibilities. Furthermore, the modified or new glass formulations, which can incorporate more waste oxides into the glass matrix, known as high-waste loading glasses, also have been developed in parallel.

Microstructure and mechanical properties of a modified 316 austenitic stainless steel alloy manufactured by laser powder bed fusion

A 316 austenitic stainless-steel alloy, with modified alloy composition, manufactured by laser powder bed fusion (L-PBF) has been investigated. The modification of the alloy composition included addition of niobium (Nb), tungsten (W) and copper (Cu), together with a reduction in the amount of molybdenum (Mo) and an increased amount of carbon (C). To find suitable process parameters, a parameter study by varying laser power, hatch distance and scan speed was performed, centered on typical parameters used for normal 316 L. As-built material from a selected parameter configuration was then subjected to different stress relief annealing heat treatments and ageing heat treatments. The effectiveness of the stress annealing was ranked using a deformation-based method. Microstructural characterization, hardness and room temperature tensile testing were done to evaluate the effect of stress relief and aging heat treatments.It was found that a higher volumetric energy was needed to build dense material, about ∼50 % higher compared to the volumetric energy input for normal 316 L. A subsequent aging heat treatment at 725 °C for 3 h increased the strength and hardness of the material. A reinforcement of the cellular microstructure by precipitation of carbides in between the cells is believed to be the main reason for this. To completely alleviate the residual stresses it was necessary to carry out a stress relief annealing process at 950 °C, which resulted in a removal of the cellular structure and a lower strength material.

An innovative strategy for deeply separating macro amounts of molybdenum from tungstate solutions via vulcanization step-by-step and microbubble floating-extraction: Theoretical and experimental investigation

The gradually increasing demand for high-purity tungsten products has become a key challenge and attracted considerable attention in chemical industry, the premise of which is to achieve the deep separation of molybdenum impurities from tungstate solutions. An innovative separation of molybdenum impurity from tungstate solutions were systematically investigated in this work. On the foundation of the theoretical analysis, a novel strategy named vulcanization step-by-step and the vulcanized trajectory of which were proposed. It was found that the thiomolybdate method is still suitable to separate molybdenum from tungstate solutions (Mo/WO3 > 2 wt%) based on the vulcanization step-by-step, and satisfactory separation results were obtained by microbubble floating-extraction. Under optimized conditions, the separation efficiency of molybdenum can reach over 99 %, and the loss of tungsten is approximately 2 %. As a results, the tungstate solutions with Mo/WO3 less than 2 × 10−6 was obtained. Subsequently, the tungsten products (WO3) with a purity greater than 99.99 % was prepared from purified tungstate solutions. Ultimately, the microbubble floating-extraction mechanisms including the mineralization behaviors of target component, the attachment behaviors of hydrophobic complexes on the surface of rising microbubbles and the mass transfer process at the oil–water phase were comprehensively interpreted at the molecular level. This work can provide an important technical support for the preparation of high-purity tungsten products from tungstate solutions containing macro amount of molybdenum.

Tuning Catalyst Selectivity for Ammonia vs Hydrogen: An Investigation into the Coprecipitation of Mo and Fe Sulfides.

Iron sulfides are key materials in metalloprotein catalysis. One interesting aspect of iron sulfides in biology is the incorporation of secondary metals, for example, Mo, in nitrogenase. These secondary metals may provide vital clues as to how these enzymes first emerged in nature. In this work, we examined the materials resulting from the coprecipitation of molybdenum with iron sulfides using X-ray absorption spectroscopy (XAS). The materials were tested as catalysts, and direct reductants using nitrite (NO2-) and protons (H+) as test substrates. It was found that Mo will coprecipitate with iron as sulfides, however, in distinct ways depending on the stoichiometric ratios of Mo, Fe, and HS-. It was observed that the selectivity of reduction products depends on the amount of molybdenum, with the presence of approximately at 10% Mo optimizing ammonium/ammonia (NH4+/NH3) production from NO2- and minimizing competitive hydrogen (H2) formation from protons (H+) with a secondary reductant.

Adsorption Removal of Mo(VI) from an Aqueous Solution by Alumina with the Subsequent Regeneration of the Adsorbent.

Industrial wastewater is the main source of an excessive amount of molybdenum (Mo) in natural ecosystems. It is necessary to remove Mo from wastewater before it is discharged into the environment. Molybdate ion(VI) is the most common form of Mo in natural reservoirs and industrial wastewater. In this work, the sorption removal of Mo(VI) from an aqueous medium was evaluated using aluminum oxide. The influence of such factors as the pH of the solution and the temperature was evaluated. Three adsorption isotherms, namely, Langmuir, Freundlich and Temkin, were used to describe the experimental results. It was found that the pseudo-first order kinetic model better fits the kinetic data of the adsorption process, and the maximum Mo(VI) adsorption capacity was 31 mg/g at 25 °C and pH 4. The thermodynamic parameters indicated that the process of Mo(VI) adsorption on Al2O3 was exothermic and spontaneous. It was shown that the adsorption of Mo strongly depends on pH. The most effective adsorption was observed at pH values below 7. Experiments on adsorbent regeneration showed that Mo(VI) can be effectively desorbed from the aluminum oxide surface into a phosphate solution in a wide range of pH values. After the desorption of Mo(VI) in a phosphate solution, alumina was found to be suitable for repeating the procedure at least five times.

Forensic characterization and differentiation of automotive lubricating greases using Fourier Transform Infrared spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy

Automotive lubricating greases may be recovered as stains on the ground at vehicular accident scenes or on the garments of persons of interest (i.e., suspects or victims) allegedly involved in events under investigation. Numerous studies have been performed differentiating automotive motor oil for forensic applications, however little research has been conducted to characterize and differentiate automotive greases for forensic purposes. This study aims to determine physical and chemical properties of greases to help with their characterization and differentiation in a forensic setting. Thirty-five commercially available grease samples were obtained from major US hardware stores and were initially characterized using light microscopy methods; then they were subsequently examined using attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). The initial microscopical assessment showed the presence of microscopic particles that were part of the original formulation of the grease samples. In terms of shapes, sizes, colors, optical properties, and concentration, these particles differed considerably between the grease samples. Three classes of particles were identified and consequently labelled as opaque, isotropic, and anisotropic. ATR-FTIR spectroscopy enabled obtaining a common infrared profile characteristic of all for grease samples. Close inspection of the spectra also highlighted the presence of minor infrared absorption bands that were useful to the differentiation of different grease samples. Because of the high interference of the lubricating medium of the grease samples during SEM-EDS analyses, an oil-solid separation procedure to extract the observed microscopic particles from the grease medium was developed based on the investigation of three solvents – two petroleum solvents, hexane, and pentane, and one green solvent, D-limonene – which led to the selection of D-limonene. The developed extraction method enabled the successful isolation of the detected particles for conducting SEM-EDS analyses. The opaque particles were identified as solid lubricant additives, containing various amounts of molybdenum and niobium. Grease samples that did not contain opaque particles were missing these heavy elements. These differences in composition offered increased discriminating capabilities for the differentiation of automotive greases, also considering that such particles are not present in other automotive lubricating fluids like motor oils or brake fluids.

Phytochemical constituents and nutrient evaluation of date palm (Phoenix dactylifera, L.) pollen grains

The pollen of date palm -DPP (Phoenix dactylifera L. variety El- Ghannmi Ahmar.) has been analyzed for the main phytochemical composition , nutrient and mineral composition. The phytochemical screening of chemical constituents of the plant showed that the DPP grains contains phytosterols, flavonoids, alkaloids, protein, carbohydrates, glycosides, phenolic compounds, tannins, terpenoids, saponins, coumarins, lignin, oil and fats, with absent of quinones. The quantitative contents of alkaloids, tannin, phenolic compounds and sterols were (2416±0.034, 2279.6±35.769, 115±5 and 110.1±0.87) mg/100g in DPP grains. While the moisture content of palm pollen grains was 8.041 ± 0.1%, and 91.959 ± 0.1 % for the total solids. Values 0.113±0.003 % and 5.585 ± 0.144 % were estimated for crude fiber and ash contents respectively. Crude fat content of DPP grains was 7.678 ±0.149%, 19.45%, for crude protein and 26.25±0.315 g/100g for carbohydrates ,the energy value was 291.902 Kcal/100g. The predominant minerals were potassium 73.5 mg/g, followed by magnesium 19.6 mg/g , calcium 10.8 mg/g and iron 8.5 mg/g. Comparable amounts of sodium 4.34 mg/g and copper 3.658 mg/g with equal amounts of molybdenum, nitrogen and boron (3.169, 3.11 and 3.024) mg/g respectively were found in DPP grains. Palm pollen also contain useful amount of zinc 2.799 mg/g, manganese 2.702 mg/g, selenium 2.51 mg/g, cobalt 1.986 mg/g, nickel 1.698 mg/g and cadmium 0.12 mg/g. From all the results we can conclude that the date palm pollen was as rich source of antioxidant, energy, and important minerals, so its suitability as a regular component in human diet.

Induction heating: an efficient methodology for the synthesis of functional core-shell nanoparticles.

Induction heating has been applied for a variety of purposes over the years, including hyperthermia-induced cell death, industrial manufacturing, and heterogeneous catalysis. However, its potential in materials synthesis has not been extensively studied. Herein, we have demonstrated magnetic induction heating-assisted synthesis of core-shell nanoparticles starting from a magnetic core. The induction heating approach allows an easy synthesis of FeNi3@Mo and Fe2.2C@Mo nanoparticles containing a significantly higher amount of molybdenum on the surface than similar materials synthesized using conventional heating. Exhaustive electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy characterization data are presented to establish the core-shell structures. Furthermore, the molybdenum shell was transformed into the Mo2C phase, and the catalytic activity of the resulting nanoparticles tested for the propane dry reforming reaction under induction heating. Lastly, the beneficial role of induction heating-mediated synthesis was extended toward the preparation of the FeNi3@WOx core-shell nanoparticles.

Entrapment of Mo-reducing Bacterium Increase its Resistance towards Mercury

In ruminants, even trace amounts of molybdenum can be lethal. In areas with high pollution, molybdenum levels in soil and mine tailings can exceed 20,000 ppm. Bioremediation of molybdenum can be challenging when toxic mercury is also present. This research presents a novel approach using dialysis tubing and the molybdenum-reducing activity of Enterobacter sp. strain Dr. Y13 for molybdenum removal from aqueous solutions. Molybdenum blue (Mo-blue), produced during enzymatic reduction, is insoluble in dialysis tubing and this can be a twofold advantage as a method of removal and as a method to protect bacterial cells from heavy metal inhibition, especially mercury. In this experiment, we assess the toxicity-shielding effect of dialysis tubing for molybdenum reduction to Mo-blue by this bacterium in the presence of mercury. As the concentrations of mercury were increased, both free and immobilized cells were strongly inhibited. Modelling using the dissociationone phase exponential decay model gave an IC50 value for the immobilized form of 0.1107 mg/L (95% confidence interval from 0.073 to 0.217 while the IC50 value for the free cell system was 0.023 mg/L (95% C.I. from 0.019 to 0.028). Since the confidence interval for the IC50 values did not overlap, the immobilized system gave better protection from mercury than the free cell system. Toxicity to free cells was higher than toxicity to cells trapped in dialysis tubes, suggesting that trapping Mo-reducing cells may be an effective strategy for bioremediation of water or wastewater contaminated with multiple heavy metals.

Immobilization of Bacillus sp. Strain Neni-8 in Dialysis Tubing Reduced Copper Toxicity to the Molybdenum Reduction Process

In ruminants, even trace amounts of molybdenum can be lethal. In areas with high pollution, molybdenum levels in soil and mine tailings can exceed 20,000 ppm. Bioremediation of molybdenum can be challenging when toxic copper is also present. This research presents a novel approach using dialysis tubing and the molybdenum-reducing activity of Bacillus sp. strain Neni-8 for molybdenum removal from aqueous solutions. Molybdenum blue (Mo-blue), produced during enzymatic reduction, is insoluble in dialysis tubing and this can be a twofold advantage as a method of removal and as a method to protect bacterial cells from heavy metal inhibition, especially copper. In this experiment, we assess the toxicity-shielding effect of dialysis tubing for molybdenum reduction to Mo-blue by this bacterium in the presence of copper. As the concentrations of copper were increased, both free and immobilized cells were strongly inhibited. Modelling using the dissociationone-phase exponential decay model gave an IC50 value for the immobilized form of 0.1107 mg/L (95% confidence interval from 0.073 to 0.217 while the IC50 value for the free cell system was 0.023 mg/L (95% C.I. from 0.019 to 0.028). Since the confidence interval for the IC50 values did not overlap, the immobilized system gave better protection from copper than the free cell system. Toxicity to free cells was higher than toxicity to cells trapped in dialysis tubes, suggesting that trapping Mo-reducing cells may be an effective strategy for the bioremediation of water or wastewater contaminated with multiple heavy metals.

OBTAINING OF A COMPOSITE COATING OF COPPER-MOLYBDENUM (VI) OXIDE WITH CATHODIC POLARIZATION

In this paper, considered the ways of obtaining a composite electrochemical coating by entering molybdenum (VI) oxide into the copper matrix in order to improve the physicochemical properties of the copper coating. The influence of electrochemical parameters (solution concentration, current density, concentration of molybdenum (VI) oxide) is investigated with cathodic polarization of a titanium electrode in aqueous solutions of copper sulfate. In the course of studies of the influence of the concentration of a dispersed particle that is part of a copper-molybdenum oxide (VI) composite, it was found that at high concentrations of dispersed particles in solution, the cathode surface is passivated and the optimal concentration of the dispersed component is determined. It was noted that with increasing current density, the amount of molybdenum (VI) oxide penetrating into the copper matrix increases slightly, these data were explained by the charge difference of the particles, as well as adsorption properties. As a result of the study, a compact composite coating on the cathode in a dispersed suspension of the composite in a solution of copper (II) sulfate was obtained. The results of the physico-chemical analysis of the resulting composite coating showed that 1.2% dispersed molybdenum (VI) oxide entered the copper matrix. As a result of tests of a composite coating made of copper-molybdenum oxide for chemical corrosion, it was found that this coating has high corrosion resistance from a copper coating obtained without molybdenum (VI) oxide. The surface roughness of the coating obtained on the cathode surface was observed in microphotographs. This was explained by the fact that molybdenum (VI) oxide penetrates into the copper matrix in the form of dispersed granules and forms a composite electrochemical shell with a copper coating.

Co-exposure to molybdenum and cadmium triggers pyroptosis and autophagy by PI3K/AKT axis in duck spleens.

Excessive amounts of molybdenum (Mo) and cadmium (Cd) are toxicant, but their combined immunotoxicity are not clearly understood. To estimate united impacts of Mo and Cd on pyroptosis and autophagy by PI3K/AKT axis in duck spleens, Mo or/and Cd subchronic toxicity models of ducks were established by feeding diets with different dosages of Mo or/and Cd. Data show that Mo or/and Cd cause oxidative stress by increasing MDA concentration, and decreasing T-AOC, CAT, GSH-Px and T-SOD activities, restrain PI3K/AKT axis by decreasing PI3K, AKT, p-AKT expression levels, which evokes pyroptosis and autophagy by elevating IL-1β, IL-18 concentrations and NLRP3, Caspase-1, ASC, GSDME, GSDMA, NEK7, IL-1β, IL-18 expression levels, promoting autophagosomes, LC3 puncta, Atg5, LC3A, LC3B, LC3II/LC3I and Beclin-1 expression levels, and reducing expression levels of P62 and Dynein. Furthermore, the variations of abovementioned indexes are most pronounced in co-treated group. Overall, results reveal that Mo or/and Cd may evoke pyroptosis and autophagy by PI3K/AKT axis in duck spleens. The association of Mo and Cd exacerbates the changes.

The Application of Geologic Mapping, Core Logging, and 3-D Geoscientific Data Integration in the Exploration and Resource Expansion of Porphyry Copper-(Gold) Deposits: Examples from Recent Discoveries in Ecuador and Chile

Abstract The collection of accurate geologic data is critical in minerals exploration. The successful visualization, integration, and interpretation of quantitative vein abundance data, associated selvages of wall-rock alteration mineralogy, sulfide mineral proportions, and metal zoning facilitate the path to discovery and orebody delineation. The application of the Anaconda method, developed by the Anaconda Copper Mining Company geologists in the 1960s, to geologic mapping and drill core logging has facilitated the discovery and resource expansion in the giant Alpala porphyry Cu-Au-Ag deposit in northern Ecuador and the Cortadera porphyry Cu-Au-Mo deposit cluster in northern Chile. In both porphyry systems, high-grade zones have been targeted through the delineation of an intrusion and vein chronology that allows for the recognition of early-stage causal intrusions, zones of abundant porphyry-style quartz veins, and elevated chalcopyrite to pyrite ratios. Increased amounts of molybdenum, as molybdenite along fractures and in quartz veins, as well as anhydrite veins and disseminations, correlate with proximity to the deposit cores. The field-based methods presented in this article have proven useful in porphyry exploration for decades. The application of the Anaconda method of geologic mapping and core logging by geologists can assist in the targeting of high-grade cores of deposits and improved estimation of metal resources.