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Abstract Rare earth elements (REEs) exhibit diagnostic absorption features in the visible-near infrared region, enabling their detection and identification via spectroscopic methods. Satellite-based remote sensing mapping of REEs, however, has not been attainable so far due to the necessity for high-quality hyperspectral data to resolve their narrow absorption features. This research leverages EnMAP hyperspectral satellite data to map REEs in Mountain Pass, California—a mining area known to host bastnaesite-Ce ore in sövite and beforsite carbonatites. By employing a polynomial fitting technique to characterize the diagnostic absorption features of Neodymium (Nd) at ∼740 and ∼800 nm, the surface occurrence of Nd was successfully mapped at a 30m pixel resolution. The relative abundance of Nd was represented using the continuum-removed area of the 800 nm feature. The resulting map, highlighting hundreds of anomalous pixels, was validated through laboratory spectroscopy, surface geology, and high-resolution satellite imagery. This study marks a major advancement in REE exploration, demonstrating for the first time, the possibility of directly detecting Nd in geologic environments using the EnMAP hyperspectral satellite data. This capability can offer a fast and cost-effective method for screening Earth’s surfaces for REE signature, complementing the existing exploration portfolio and facilitating the discovery of new resources.

Rare earth metals are considered to be some of the most critical raw materials on the planet due to their use in many products and technologies, the difficulty in isolating the individual elements from ores and each other, and the market restrictions that threaten their supply. However, despite this, the recycling rates for rare earth metals remain low. Hydrometallurgy has been proposed to hold the greatest potential for the recovery of rare earth metals from waste materials. However, the design of hydrometallurgical processes for the recovery of rare earth elements from waste requires a good understanding of the behaviour of the rare earth metals between different phases.In this study, the distribution coefficients of two rare earth metals, yttrium, and neodymium, between an organic solvent; bis(2-ethylhexyl) phosphate, diluted in n-dodecane at between 0.25 M and 1 M; and an aqueous nitric acid solution at concentrations of between 0.1 M and 2.8 M were measured. Distribution measurements were performed using a series of liquid–liquid extraction cells at a constant temperature of 298.2 K. The concentration of the rare earth metals was measured using ICP-OES analysis. The distribution coefficients and the acid concentration were found to be inversely related to each other. Conversely, the distribution coefficients were directly proportional to the concentration of the solvent in the organic phase.The data reported in this paper will be used to design a counter-current liquid–liquid extraction column for the recovery of neodymium from waste permanent magnet powder.

Abstract Molten oxide electrolysis is a promising pathway to decarbonize primary metal production. The oxide electrolyte is less hazardous and eco‐toxic than halides (molten salt electrolysis) and, with the use of renewably generated electricity and an inert anode, oxygen is produced as a by‐product instead of CO2. Building fundamental understanding of electrolytic operating windows requires starting with simple chemistries. Here we investigate a simplified binary oxide system as an electrolyte for titanium oxide reduction to metal. The TiO2−Na2O binary system forms a eutectic, reducing the liquidus temperature over a wide composition range. FactSage 8.1 predictions suggested Ti reduction would become favorable over Na reduction for compositions greater than 0.49 mole fraction TiO2. The prediction was validated by the detection of metallic Ti after electrolysis experiments. However, the reduction efficiency was too low (0.24±0.08 % at −0.1 V vs Ti reference electrode) for the TiO2−Na2O system to be a viable industrial electrolyte for Ti production. Scoping for other binary oxide systems was performed for electrolytic production of two critical metals, tantalum and neodymium. Based on TiO2−Na2O system's predicted behavior, candidate binary oxide systems were identified that contained congruently melting line compounds flanked by eutectic reactions from the ACerS‐NIST Phase Equilibria diagrams database.

Faraday’s law of electromagnetic induction is one of the four Maxwell’s equations, presented here in vector notation. Its discovery paved the way for a second industrial revolution based on machines powered by electricity. Roughly speaking, it states that the negative (a Lenz‘s contribution) of the temporal rate of change of magnetic fields acts as a source for an electric field of rotational nature. In this paper, we discuss readily replicable experiments demonstrating Faraday’s law in action, using the motion of a neodymium magnet under three natural motions: i) free fall under gravity; ii) pendular motion under gravity and iii) the magnet placed at the free end of a vibrating ruler. Due to their simplicity, these systems allow for a complete theoretical treatment. We consider more than one way of calculating the induced voltage in a circular coil, by the magnet in motion. This way, students can benefit from the multidisciplinary aspects, connecting the knowledge of kinematics of motion and the electrodynamics of particles in motion. The experimental data was obtained using an oscilloscope and contrasted to the theoretical predictions. In practice, these experiments can be used to estimate the magnetic dipole moment of a permanent magnet.

The tetrakis complex of neodymium(III), tetrakis{μ-N-[bis(pyrrolidin-1-yl)phosphoryl]acetamidato}bis(propan-2-ol)neodymiumsodium propan-2-ol monosolvate, [NaNd(C10H16Cl3N3O2)4(C3H8O)2]·C3H8O or NaNdPyr4(i-PrOH)2·i-PrOH, with the amide type CAPh ligand bis(N,N-tetramethylene)(trichloroacetyl)phosphoric acid triamide (HPyr), has been synthesized, crystallized and characterized by X-ray diffraction. The complex does not have the tetrakis(CAPh)lanthanide anion, which is typical for ester-type CAPh-based coordination compounds. Instead, the NdO8 polyhedron is formed by one oxygen atom of a 2-propanol molecule and seven oxygen atoms of CAPh ligands in the title compound. Three CAPh ligands are coordinated in a bidentate chelating manner to the NdIII ion and simultaneously binding the sodium cation by μ2-bridging PO and CO groups while the fourth CAPh ligand is coordinated to the sodium cation in a bidentate chelating manner and, due to the μ2-bridging function of the PO group, also binds the neodymium ion.

The Nd-mediated coordinative chain transfer polymerization (CCTP) of dienes represents one of the state-of-the-art techniques in the current synthetic rubber field. Besides having well-controlled polymerization behaviors as well as high atom economies, it also allows for the generation of highly reactive Al-capped polydienyl chain-ends, which hold great potential, yet much less explored up to date, in achieving end functionalization to mimic the structure of natural rubber. In this study, we demonstrate an efficient in situ method to realize end-functionalizing polyisoprene by introducing epoxide compounds into a CCTP system. The end functionalization efficiency was 92.7%, and the obtained polymers were systematically characterized by 1H NMR, 1H,1H-COSY NMR, DOSY NMR, and MALDI TOF. NMR studies revealed that a maximum of two EO units were introduced to the chain ends, and based on density functional theory (DFT) studies, an energy barrier of 33.3 kcal/mol was required to be overcome to open the ring of the EO monomer. Increasing the ratio of [Ip]/[Nd] resulted in gradually increased viscosities for the reaction medium and therefore gave rise to an end functionalization efficiency that decreased from 92.7% to 74.2%. The end hydroxyl group can also be readily converted to other functionalities, as confirmed by NMR spectroscopy.

Perovskite solar cells have attained high photoconversion efficiencies by changing chemical compositions of the perovskites and layered structures of the devices. However, the perovskite compounds easily decompose in air atmosphere even at the room temperature, and the photovoltaic properties are degraded by the formed defects. The motivation of this work is to solve these instability problems, and the objective the present work is to improve the film quality of the perovskite compounds by introducing lanthanide elements and decaphenylcyclopentasilane (DPPS), which were expected to contribute to decrease of the defects by the passivation effects. Here, effects of neodymium trifluoride (NdF3) or ytterbium trifluoride (YbF3) addition to CH3NH3PbI3 perovskite solar cells inserted with DPPS were investigated. Introduction of NdF3 or YbF3 increased the lattice constants and promoted crystal growth of the perovskites, and surface treatment by DPPS suppressed the PbI2 formation as surface passivation. Combined additions of NdF3 or YbF3 and DPPS contributed to the improvement of both the conversion efficiencies of the present perovskite devices and the stabilities of the photovoltaic properties by inhibiting the decomposition.

Neodymium(III) ortho-oxidotungstate(VI) was synthesized as a side-product in an unsuccessful synthesis attempt at fluoride derivatives of neodymium tungstate in fused silica ampoules, using neodymium(III) oxide, neodymium(III) fluoride and tungsten trioxide. Violet, platelet-shaped single crystals of the title compound emerged of the bulk, which crystallize in the defect scheelite type with a trigonal dodecahedral coordination of oxide anions around the Nd3+ cations and the hexavalent tungsten cations situated in the centers of oxide tetrahedra.

The damage excessive neodymium (Nd) causes to animals and plants should not be underestimated. However, there is little research on the impact of pH and associated ions on the toxicity of Nd. Here, a biotic ligand model (BLM) was expanded to predict the effects of pH and chief anions on the toxic impact of Nd on wheat root elongation in a simulated soil solution. The results suggested that Nd3+ and NdOH2+ were the major ions causing phytotoxicity to wheat roots at pH values of 4.5–7.0. The Nd toxicity decreased as the activities of H+, Ca2+, and Mg2+ increased but not when the activities of K+ and Na+ increased. The results indicated that H+, Ca2+, and Mg2+ competed with Nd for binding sites. An extended BLM was developed to consider the effects of pH, H+, Ca2+, and Mg2+, and the following stability constants were obtained: logKNdBL = 2.51, logKNdOHBL = 3.90, logKHBL = 4.01, logKCaBL = 2.43, and logKMgBL = 2.70. The results demonstrated that the BLM could predict the Nd toxicity well while considering the competition of H+, Ca2+, Mg2+ and the toxic species Nd3+ and NdOH2+ for binding sites.

Key Clinical Message Multiple neodymium magnets can pinch tissue and cause barotrauma. Be careful if the tissue of the penis or foreskin is pinched, as this may cause foreskin necrosis or damage to the urethra.

The sorption properties of Na-modified Ukrainian Transcarpathian clinoptilolite towards neodymium aqueous solutions under dynamic conditions have been investigated. The sorption capacity of the Na-from of Transcarpathian clinoptilolite towards Nd(III) significantly depends on the concentration of neodymium salt, the pH of the solution, and the heat treatment temperature of the sorbent. Nd(III) is most efficiently sorbed from slightly alkaline solutions (pH 8.5), mainly by adsorption of neutral hydrolyzed forms of Nd(OH)3 on the surface of Na-clinoptilolite samples preheated at 75 °C. During the passage of an Nd(III) solution with a concentration of 1 μg mL−1 through the sorbent at a rate of 3 mL min−1 under optimal conditions, the sorption capacity of Na-clinoptilolite is 7.2 mg g−1, which is in 4 and 2.3 times higher than that of natural and acid-modified forms of this zeolite. It is shown that under the experimental conditions with an increase in the flow rate, the thickness of the stationary surface layer decreases, which leads to a decrease in the sorption capacity of Na-clinoptilolite. The best Nd(III) desorbents are solutions of mineral acids and acidified solutions of alkali metal salts (except NaCl), which provide 93–98 % extraction of lanthanide from the zeolite matrix. The method for neodymium trace amounts preconcentration from aqueous solutions in a solid-phase extraction mode with a further determination of this rare earth element by a spectrophotometric method was developed. The detection limit of this method is 0.75 ng mL−1 and the linearity was evaluated in the range of 2.5–500 ng mL−1.

Plastic instability, called Portevin-Le-Chatelier (PLC) effect, manifests itself as an unstable plastic flow during tensile tests of structural materials. This phenomenon has a strong influence on diverse properties, leading to unexpected vulnerabilities in the service environment. Among various magnesium-based alloys, PLC phenomenon is most prominently observed in the Mg-Mn-Nd alloy under elevated temperature and low strain rate conditions. An important aim of the study is to clarify and compare the significance of the RE and Ca addition, which are known to cause a formation of a largely weakened non-basal type texture, in the occurrence of plastic instability. Due to the PLC phenomenon, there is a risk of weakening texture and formability improvement by the addition of RE and Ca elements in Mg alloys. Based on the understanding of the role of Nd to the PLC phenomenon in Mg-Mn alloy identified in previous studies, the PLC characteristics according to alloying elements and deformation conditions were compared and analyzed. To identify the micromechanical mechanisms of the PLC phenomenon, varies in the microstructure and mechanical properties during deformation of Mg-Mn binary and Ca or Nd-containing Mg-Mn-based ternary alloys in various conditions were systemically analyzed. The addition of Ca did not show a marked PLC effect due to the formation of low number density Mn-Ca and Ca-Ca solute clusters and an unbalanced Mn:Ca ratio. In contrast, the addition of Nd leads to the formation of a higher number density of Nd-Nd and Mn-Nd solute clusters than that of Ca-Ca and Mn-Ca solute clusters of the Mg-Mn-Ca alloy, resulting in a stable solute-dislocation interaction atmosphere under specific ranges of deformation temperature and strain rate. The deformation in the regime of PLC phenomenon, results in a decrease in ductility and an increase in strength, despite deformation at elevated temperatures with maintaining the weakened texture.

The relevance of the study is caused by the need to get knowledge of the fundamental scientific problem – the ferromanganese precipitation of the World Ocean. Marine ferromanganese deposits are records of sedimentation conditions in the past as well as promising mineral raw materials. Their formation is carried out under various processes, which are reflected in the bulk and isotopic composition of ferromanganese deposits. Currently, the least studied region of the Pacific Ocean is its northern segment. The main aim of the research is to study Sr and Nd isotopic composition of the ferromanganese crusts from the northern Pacific, formed under low detrital influx. Methods: litho-morphology; x-ray diffraction – determination of the mineral composition; mass spectrometric – determination of the chemical and isotopic composition. Results. Ferromanganese deposits of the guyots of the northern part of the Imperial Range (Detroit, Suzei, Hanzei) and the Amliya, Rat and Stailmate fracture zones, as well as the Vulkanolog Guyot (Magellan Seamounts), as a comparative material, were studied. Based on the mineralogical and geochemical bulk compositions, the studied ferromanganese deposits are classified as hydrogenetic ferromanganese crusts. The strontium isotopic composition of the studied samples is in the range from 0,70797 to 0,70919 (average 0,70885), with most of the samples concentrated at 0,709. At the same time, the content of strontium changes almost three times from 660 to 1700 ppm. The dependence of the isotopic composition on the concentration is not observed. The displacement of 87Sr/86Sr occurs towards volcanic rocks, which reflects the high amount of quartz-plagioclase admixture in the sample. The isotopic composition of neodymium, in terms of εNd, varies in the range from –3,5 to –3,0, which corresponds to the modern deep seawater of the North Pacific. An increase in εNd to –2,3 corresponds to a sample with the maximum terrigenous admixture. The minimum value of εNd (–4,4) was found in the bottom layer of the ferromanganese crust from the Hanzei Guyot. This value corresponds to the Miocene North Pacific Deep water. This is a reason to believe that in the Miocene the formation of the bulk composition of the North Pacific ferromanganese crusts was under North Atlantic Deep Waters entering through the Panama Gateway. The end of North Atlantic Deep Waters delivery to the Pacific was finished about five million years ago.

Hydroxyapatite (HA) is one of the important biomaterials in the medical field, especially in bone treatment, because of its biological properties close to human bone. A simple co-precipitation technique was used to integrate neodymium and zinc into HA by adding neodymium nitrate and zinc nitrate as a source of substituted elements during synthesis through the wet precipitation method with controlled temperature and pH. Finally, substituted HA was sintered at 800°C after completing the biomaterial preparation. The resulting Nd-Zn/HA was globe-like with nanoparticle size. The Ca+Nd+Zn/P ratio was equal to 1.63, which is relatively close to the molar ratio of bone. Also, the ability of Nd-Zn/HA to cause apoptosis in osteosarcoma cells was discovered. The anti-tumor actions are amplified when increasing the concentration of substituted HA. Therefore, Nd-Zn/HA is a potentially effective biomaterial in osteosarcoma treatment. Meanwhile, it has antibacterial and fungicidal properties against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Escherichia coli, and Candida albicans—one of the important properties required in biomaterials to protect the part that is being treated after the biomaterial is implanted inside the body. The inhibition zone of Nd-Zn/HA ranged between (20-31)mm, much higher than gentamicin and nystatin.

A series of Nd1-xCdxFeO3 (x = 0.1, 0.2 and 0.3) nanoparticles were successfully synthesized from Nd(III), Cd(II) and Fe(III) nitrates by a simple co-precipitation method in boiling water with a 5% sodium hydroxide aqueous solution (without any surfactants) and annealed at 700, 850 and 950°C for 1 h. SEM and TEM analyses showed particle sizes in the range of 50-70 nm. According to XRD the average crystallite size increased with the annealing temperature, but decreased when the cadmium concentration increased. As the annealing temperature was raised from 700 to 950°C, the magnetic properties, such as coercivity (Hc), remanent magnetization (Mr) and saturation magnetization (Ms), of the Nd0.8Cd0.2FeO3 sample also increased. In general, the Hc, Mr and Ms values increased with the degree of cadmium doping. The synthesized Nd1-xCdxFeO3 nanopowders havemuch larger coercivity values than some other rare-earth perovskites, such as Nd1-xSrxFeO3, NdFe1-xCoxO3, LaFe1-xTixO3, YFe1-xNixO3, Y1-xCdxFeO3, La1-xCdxFeO3 or Bi1-xCdxFeO3. The high Hc value (1916.52-4833.41Oe) of the synthesized Nd1-xCdxFeO3 nanopowders enables their use for permanent magnets or magnetic recording on hard disks and tapes.

Modern-day devices, transport, and green energy require growing supply of rare earth elements (REEs), which subsequently provide the basics for attempts on developing the efficient and innovative methods for their detection and exploration. Remote sensing data / techniques provide great possibilities to quick and non‑destructive exploration of such deposits, even in relatively unreachable and socially sensitive places. The diagnostic absorption features of REEs are generated in the visible to shortwave infrared (VNIR-SWIR) region of the electromagnetic spectrum, among which, the most prominent absorption features of neodymium (Nd), which could be a key pathfinder for REEs, are displayed in the VNIR region. This study assesses the capability of the Sentinel-2 MSI data for detecting absorption feature of Nd from space. This process was successfully examined and verified in the Esfordi phosphate deposit, Central Iran, and resulted the direct mapping of REE (Nd). For this purpose, firstly, the potential of the Sentinel-2 MSI data for detecting REEs was theoretically evaluated, and then, the adaptive coherence estimator (ACE) algorithm was applied for targeting Nd-bearing zones, using the field spectra of apatite as reference. Field works, X-ray diffraction (XRD), spectroscopy, and the geochemical analyses supported the achievements. The results demonstrated that Sentinel-2 MSI can capably detect the 740 nm absorption band of Nd. Generally, this research attained high overall accuracy of 88.64% for the generated map using in situ collected data for verification.

Doped lithium titanate is known to be able to reversibly cycle in the potential range from 3 to 0.01 V and this ability depends both on the nature of the dopant and the doping level. In this work Li4Ti5O12 samples doped with Nd in the amount of 0.5 to 2.0% were studied. It was shown that while being cycled in the extended potential range, the samples with the doping level from 0.5 to 1.0% demonstrated the highest capacity.

Rare earths namely lanthanum (La), neodymium (Nd) and cerium (Ce) obtained from the monazite concentrate processing were comprehensively characterized using XRF, XRD, FTIR, N2adsorption–desorption, CO2/NH3-TPD and SEM to reveal their catalytic performance in esterification of oleic acid for biodiesel production. The effect of calcination temperatures (500–1000 °C) on the catalyst properties and biodiesel conversion was also investigated. The catalytic performances of the catalysts were tested under the conditions of catalyst loading 3 wt%, molar ratio of oil to methanol 1:20, reaction temperature 200 °C, stirring rate 600 rpm for 5 h. It is interesting that the Ce catalyst calcined at 1000 °C showed the best performance and the highest FAME content of 78.54% could be achieved, even its acid sites was very low, which is probably associated to the availability of oxygen vacancies at high calcination temperature. The La catalysts calcined at 600 °C exhibited the balancing of strong Lewis acid and Lewis basic sites, which is related to the catalytic activity with FAME content of 74.44%. For the catalytic performance of Nd catalysts, the FAME content of 63.60% was obtained at calcination temperature of 500 °C, which was lower than those La and Ce catalysts.

Nd-based polydiene elastomers, including NdIR and NdBR, are regarded as indispensable key raw materials in preparing green tires with excellent performance capabilities, but their wide application is still limited by the relative higher cost of Nd precatalysts. Nd-mediated coordinative chain transfer polymerization (CCTP) of diene provides an effective strategy to reduce the precatalyst cost, because this method involves very high atom economy, i.e., each Nd molecule can generate multiple polymer chains. Nevertheless, all possible factors that could influence such CCTP behaviors are still mostly unexplored to date. In this report, the basic chemistry on the influence of external donors on the overall CCTP behaviors of isoprene was established for the first time. It was found that increasing the amount of external donors had a negative influence on the chain transfer efficiencies, resulting in gradually decreasing atom economies. Catalyst addition order studies revealed that the coordination of donors with cationic Nd active species, rather than alkylaluminium CTAs, contributed mostly to such decreased efficiencies. Moreover, it was found that when the ratio of donors and Nd compounds was higher than 1.0, the CCTP behaviors were corrupted, resulting in polymers with broad distributions, as well as resulting in low atom economies; nevertheless, when the ratio was lower than 0.5, the system still displayed CCTP characteristics, implying that the critical ratio for maintaining the CCTP was 0.5. Additionally, when such a ratio was 0.01, the high atom economy was almost the same as donor-free CCTP systems. Detailed kinetic studies at such a ratio demonstrated that the donor-contained system proceeded in a well-controlled manner, as concluded from the good linear relationship between the Mn of the PIps against the polymer yields, as well as the good linearity between the Mn against the (IP)/(Nd) ratios. Such maintained CCTP properties also allowed for seeding two-step polymerizations to prepare diblock copolymers with precisely controlled molecular weights. Expanding the types of donors to more phosphine, oxygen, and nitrogen containing compounds showed that they also affected the CCTP behaviors depending on their steric and electronic properties.

This study aims to investigate the optical properties of multiple neodymium-doped gadolinium compounds as a means to examine their eligibility as optical probes for fluorescence imaging. GdVO4, GdPO4, GdAlO3, Gd2SiO5 and Gd3Ga5O12 (GGG) samples were synthesized through solid-state reactions with varying neodymium doping levels to compare their optical properties in great detail. The optimal doping concentration was generally found to be approximately 2%. Furthermore, the luminescence lifetime, which is a valuable parameter for time-gated imaging, was determined to range from 276 down to 14 µs for the highest doping concentrations, resulting from energy transfer and migration assisted decay.

Seeds stored for a prolonged period are subject to aging and a reduction in germination potential (GP), which will negatively affect seed sales. Rare-earth elements have a synergistic effect on the improvement of seed GP. In this study, we examined the effects of neodymium on biochemical components, the antioxidant protective system, and metabolism-related enzymes during germination of naturally and artificially aged seeds of three wheat cultivars. Seed germination indices, biochemical substance contents, and enzyme activities decreased after seed aging. Soaking seeds in a neodymium nitrate solution revived aged wheat seeds at an optimal concentration of 20 µmol/L for 8 h. Soaking in a neodymium nitrate solution increased the GP4 (by 2.25–60.9%), germination index (by 1.69–29.2%), and vigor index (by 3.36–18.7%) of aged seeds. Compared with non-soaked seeds, soaking significantly changed the contents of biochemical substances, and the activities of antioxidant protective enzymes and metabolic enzymes in seedlings were increased. Soaking with neodymium may revive aged seeds by regulating the synthesis of soluble sugars, soluble proteins, chlorophyll, and carotenoids and decomposing malondialdehyde in the germinating seed. Root dehydrogenase and amylase showed different responses to the aging modes. The differential responses of root dehydrogenase and amylase may reflect differences in the resistance of enzymes to long-term mild seed aging and short-term severe environmental aging.

Even though Mg alloys containing Mn and rare earth elements lead to higher ductility and lower yield asymmetry due to the weak texture after extrusion, plastic instability, commonly known as the Portevin–Le Chatelier (PLC) effect, causes unexpected fragility in the service environment. In the present study, the PLC phenomenon and texture development during the deformation of Mg-Mn and Mg-Mn-Nd extruded alloys were investigated under various temperatures and strain rates. The addition of Nd causes not only texture weakening but also severe PLC phenomenon. The PLC phenomenon was significantly affected by the temperatures and the strain rates, which causes a difference in mechanical properties and development of texture. In the conditions of high temperature and low strain rate, the strength increased while the elongation decreased significantly, and obvious PLC phenomenon with severe serration and negative strain rate sensitivity. The initial texture was maintained even after deformation only under severe PLC conditions, and this is due to the restriction of basal slip and suppression of lattice rotation in PLC conditions. The series of results indicate that the PLC phenomenon causes a reduction of formability even at high temperature.

This work obtained a sorbent based on humic acids (HA) isolated from oxidized brown coals of the Maikuben deposit. The study of humic acids by IR spectroscopy showed the presence of various functional groups (OH-, COOH-) in the sorbent, which can enter into ion-exchange reactions with metals. Humic acids have been tested as a sorbent for neodymium. Neodymium sorption was carried out under static conditions from nitrate solutions. It was found that with a sorption time of 30 min and a solution pH is 1.0, the sorption efficiency of neodymium is 95.5%. A sorbent based on humic acids was used to separate neodymium from a solution obtained by dissolving electronic waste (neodymium magnet). SEM-analysis and mapping of the sorbent surface after neodymium sorption showed that neodymium was absent on the sorbent surface.

Neodymium (Nd) is one of the most essential rare-earth metals due to its outstanding properties and crucial role in green energy technologies such as wind turbines and electric vehicles. Some of the key uses includes permanent magnets present in technological applications such as mobile phones and hard disk drives, and in nickel metal hydride batteries. Nd demand is continually growing, but reserves are severely limited, which has put its continued availability at risk. Nd recovery from end-of-life products is one of the most interesting ways to tackle the availability challenge. This perspective concentrates on the different methods to recover Nd from permanent magnets and rechargeable batteries, covering the most developed processes, hydrometallurgy and pyrometallurgy, and with a special focus on electrodeposition using highly electrochemical stable media (e.g., ionic liquids). Among all the ionic liquid chemistries, only phosphonium ionic liquids have been studied in-depth, exploring the impact of temperature, electrodeposition potential, salt concentration, additives (e.g., water) and solvation on the electrodeposition quality and quantity. Finally, the importance of investigating new ionic liquid chemistries, as well as the effect of other metal impurities in the ionic liquid on the deposit composition or the stability of the ionic liquids are discussed. This points to important directions for future work in the field to achieve the important goal of efficient and selective Nd recovery to overcome the increasingly critical supply problems.

Clay mineral authigenesis at continental margins plays an important role in global marine element cycles. However, despite being increasingly used as tracers for both modern and past oceanographic conditions, the behavior of the rare earth elements (REEs) and their isotopes during marine clay authigenesis still remains poorly known. In this study, we report on a detailed geochemical investigation of glauconite from the West African continental shelf, near the mouth of the Congo River. Elemental, neodymium, and hafnium isotope analyses were conducted on both acid leachate and separated clay-size fractions of glauconite pellets, in order to investigate the behavior of REE during the formation of authigenic clays. Our data indicate that kaolinite dissolution and subsequent Fe-bearing clay authigenesis act as a net source of REEs to seawater. We show that enhanced glauconitization, as inferred from increasing Fe and K contents, is accompanied by significant decoupling of the REE toward markedly LREE-enriched shale-normalized patterns in neoformed clay separates. Using both Nd and Hf isotopes and SEM observations, we rule out any seawater influence and argue that this shift primarily reflects the progressively overwhelming presence of insoluble nanocrystals of detrital LREE-rich phosphates, which are known to occur in close association with kaolinite in tropical soils. Due to their marked insolubility in surface environments, such nanocrystals can be preserved during kaolinite dissolution and subsequently incorporated into the aggregates of authigenic green clays forming the peloids. Most strikingly, we show that the combined influence of net REE loss (due to kaolinite dissolution) and decoupling (due to subsequent entrapment of inherited LREE-bearing accessory phases into neoformed clay minerals) is accompanied by preferential release of a dissolved REE fraction characterized by seawater-like distribution patterns. These findings reinforce the emerging view that clay mineral dissolution and authigenesis at continental margins possibly play a major role in marine REE cycling.

The Microbial Desalination Cell is a novel method for desalinating water that also generates energy via substrate oxidation. The MDC comprises three chambers: the anode chamber, the desalination chamber, and the cathode chamber. The fundamental problem with the technology is that it generates very little power during the oxygen reduction reaction (ORR). One solution to this issue is to use a highly active cathode catalyst, which effectively increases the ORR rate. Neodymium-doped ZnO nanoparticles were produced and employed as a cathode catalyst in the three-chambered MDC1 to improve performance. Zn1−xNdxO nanocrystalline samples containing x = 0.0, 0.03, 0.6, and 0.10 were synthesized efficiently through the cost-efficient sol-gel method. Transmission electron microscopy (TEM) and X-ray diffraction techniques revealed the nanocrystalline nature and the phase purity of the Zn1−xNdxO samples. The structural properties of ZnO nanostructured materials were elucidated by Rietveld refinement of the XRD patterns, which showed displacement of Zn and O ions and revealed changes in the electron density around the Zn-O bond with Nd substitution. The local features of light emission from Zn1−xNdxO samples have been studied with photoluminescence. The UV and green-yellow emissions originate from the exciton transition and the transition between the Nd3+ deep level, oxygen vacancy and interstitial oxygen. The results were compared to MDC-2, which did not have a catalyst on the cathode. Both MDCs were tested using a saline water solution containing 15 g/L of NaCl to measure their desalination performance. The better reduction kinetics was confirmed by cyclic voltammetry of the MDC-1 cathode. MDC-1 had a higher desalination efficiency (77.02% ± 2.0%) due to the presence of an Nd-doped ZnO catalyst than MDC-2 (59.3% ± 8.3%). MDC-1’s maximum power density of 3.65 W/m3 was 2.78 times greater than MDC-2’s (0.78 W/m3). Furthermore, the coulombic efficiency of MDC-1 was found to be (8.8 ± 0.3%), which was much higher than that of MDC-2 (4.56 ± 0.2%). As a result, the Nd-doped ZnO-based catalyst developed in this study can potentially improve ORR in MDC cathodes, enabling them to generate more power.

After mechanical pre-treatment, the typical hydrometallurgical route of NdFeB magnet recycling starts with leaching in acidic solutions. However, due to the high concentration of iron ions in the leaching solution, the selective recovery of rare earths from the solution is challenging. In our work, the selective precipitation of rare earth oxalates as a potential separation method was proposed. The precipitation of neodymium oxalate was first tested on model solutions, which was then followed by experimental tests carried out on real solutions after the leaching of NdFeB magnets. The recovery of rare earths in the form of oxalates was investigated with the use of different amounts of oxalic acid in relation to its stoichiometric amount. The most efficient separation of rare earths was observed in the case where sulfuric acid was used for leaching. The use of oxalic acid in stoichiometric amounts resulted in the precipitation of about 93% of all rare earths present in the solution, whereas the concentration of Fe and other elements (Ni, Co, and B) practically did not change. An increase in oxalic acid of 20% and 40% more than the stoichiometric amount (100%) led to the increase in the precipitation efficiency of rare earths to 96.7% and 98.1%, respectively. However, the use of oxalic acid in a 1.4 ratio caused a 7% decrease in Fe concentration, which suggests Fe co-precipitation. In order to investigate a possibility of further increasing the separation of rare earths from iron, an additional method was tested, in which iron was first oxidized from Fe2+ to Fe3+ before the precipitation of rare earth oxalates.

Hydrometallurgical methods for NdFeB recycling typically consist of several unit operations and require the extensive use of energy, water and chemicals which may negatively affect the applicability of these methods on an industrial scale. Based on the data from our previous studies, a simplified process of rare earth elements (REE) recovery from spent NdFeB magnets was developed further. The possibility of regenerating the leaching agent, as well as water recovery, in the process was investigated. This study also investigates a possibility of scaling up the recycling process developed on a laboratory scale. The leaching and precipitation stages were tested on a larger scale, where about 1 kg of end-of-life magnets was used as feed to the leaching step. In this study, end-of-life magnets were obtained from the manual disassembly of computer hard disc drives. After disassembly, the magnets were demagnetized, broken into pieces and fed to the leaching process. In the following step, rare earths were precipitated in the form of oxalates. The rare earths’ precipitation efficiency reached a maximum of 95.6%. The results showed that the co-precipitation of Fe highly depends on the amount of oxalic acid used as the precipitant. Smaller losses of Fe were achieved while using a stoichiometric amount of oxalic acid in relation to the REE present in the solution. At the end of the investigated process, rare earth oxalates were calcinated to oxides and their purity was investigated. The recirculation of a solution after oxalate precipitation and acid regeneration was tested with hydrochloric and sulfuric acids used as leaching agents. Solution recirculation was found to be possible only in the case of hydrochloric acid.

Inorganic perovskite nanostructures based on neodymium (Nd) were processed in form of nanostructures for bi-functional electrocatalytic reactions. The active role of Co ions in influencing the material characteristics of Nd-ferrite (NdFeO3) were investigated in detail. The nanostructural characteristics were adjudged through the aid of diffraction and high-resolution microscopic studies. Evidences relating to the co-occurrence of neodymium oxides (Nd2O3) were also noticed. The valency of Nd, Co and Fe ions and their nature of interaction in the ferrite architecture was studied through X-ray photoelectron spectroscopy. Here, convincing affirmations relating to the partial substitution of Co ions in place of Nd and Fe sites were also made. NdFeO3 and NdxCo1-xFeO3 nanostructures were studied for their electrocatalytic functions under varied alkaline pH (10 and 14) conditions. The improved conductivity studied via electrochemical impedance analysis in Co incorporated ferrites were noted to accelerate oxygen/hydrogen production in the corresponding electrodes. The overpotential values corresponding to oxygen evolution reactions reduced to 198 mV from 227 mV, while hydrogen evolution reactions lowered to 206 mV from 239 mV upon Co substitution. Similarly, the related Tafel slope values got improved in Co substituted ferrite matrix. The overall stability related electrochemical data suggested the processed ferrites as viable bi-functional electrocatalysts possessing essential features required for effective oxygen and hydrogen evolution reactions.

Biologically enhanced transport of radionuclides is one of several processes that can affect the performance of a nuclear waste repository. In this work, several microbial isolates from the Waste Isolation Pilot Plant (WIPP) were tested for their influence on the concentration of neodymium, as an analog for +3 actinides, in simple sodium chloride solutions and in anoxic WIPP brines. Batch sorption experiments were carried out over a period of 4–5 weeks. In many cases, the effect on neodymium in solution was immediate and extensive and assumed to be due to surface complexation. However, over time, the continued loss of Nd from the solution was more likely due to biologically induced precipitation and/or mineralization and possible entrapment in extracellular polymeric substances. The results showed no correlation between organism type and the extent of its influence on neodymium in solution. However, a correlation was observed between different test matrices (simple NaCl versus high-magnesium brine versus high-NaCl brine). Further experiments were conducted to test these matrix effects, and the results showed a significant effect of magnesium concentration on the ability of microorganisms to remove Nd from solution. Possible mechanisms include cation competition and the alteration of cell surface structures. This suggests that the aqueous chemistry of the WIPP environs could play a larger role in the final disposition of +3 actinides than the microbiology.

China, Vietnam, Brazil, and Russia have the largest deposits of rare earths. However, in recent works, the occurrence of light rare earth elements has been demonstrated in an exhalative sedimentary type mineral (SEDEX) in Mexico, with adequate Ce and Nd contents. Additionally, it is this mineral that has been used to study the cation exchange capacity of non-metallic minerals and organic materials, such as bentonite, diatomite, and eggshell. To carry out this work, the crushed and ground SEDEX ore was leached using HCl, H2SO4, and HNO3. Subsequently, the liquid containing the Ce and Nd ions extracted from the mineral was put in contact with the respective ion exchangers, evaluating the effect of temperature and pH to determine the cation exchange efficiency of each exchanger tried. It was found that the best leaching results were achieved with the H2SO4, obtaining an extraction of Ce and Nd of 97.6% and 95.7%, respectively. On the other hand, in the case of cation exchange, the best results found for the extraction of Ce and Nd were using diatomite at a temperature of 323 K and a pH of 3, obtaining an extraction of 99.06% Ce and 99.07% Nd.

Abstract A thermometer based on single Nd3 + :Y2O3 nanoparticles is reported. The nanothermometer relies on the ratio of thermally coupled Nd3 + emission lines accessible by either continuous‐wave upconversion under 880 nm or downconversion under 532 nm excitation wavelengths. Both processes are modeled through rate equation systems based on multiphonon interactions between excited luminescent states, which led to excellent agreement with the experimental data. Moreover, the Y2O3 effective phonon mode energy was determined, showing the appropriateness of the theoretical approach used. The system presented a relative sensitivity up to 1.36% at 300 K while working within the first biological window, thus particularly useful for biological sensing applications.

Background: Gadolinium oxide nanoparticles as positive contrast material of magnetic resonance imaging (MRI) have attracted a great attention due to the appropriate magnetic properties. One of the most desirable features of these nanoparticles is their ability of doping with other lanthanides which can change their properties. Objective: This study aimed to investigate the effect of neodymium doping on MRI relaxivity of the gadolinium oxide nanoparticles.Material and Methods: In this experimental study, the oleic acid coated gadolinium oxide nanoparticles and the neodymium doped nanoparticles were prepared by polymer pyrolysis method. X-ray diffraction test and scanning electron microscopy were used for characterization of the particles. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to investigate the in vitro cell toxicity of the nanoparticles. The r1 and r2 relaxivities were extracted from the T1 and T2 weighted MR images, respectively. Results: The average size of the cytocompatible spherical-like shape nanoparticles was 40 nm. The neodymium doped nanoparticles produced a significant decrease in the r1 relaxivity, and a 1.7 fold increase in the r2 relaxivity compared to the gadolinium oxide nanoparticles. Conclusion: Doping of neodymium into the gadolinium oxide nanoparticles suppresses the r1 relaxivity and enhances the r2 relaxivity of the nanoparticles.

The purpose of this study was to evaluate phase changes and magnetic properties of neodymium doped Ni0.7Zn0.3NdxFe2-xO4 (x = 0, 0.01, 0.03, 0.05, 0.07, 0.10) nanoparticles synthesized by complexing sol-gel method. In this method, triethanolamine (TEA) acted as both a gelling agent and a chelating agent. Samples were characterized by X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDX). XRD patterns of all synthesized samples revealed the formation of a spinel ferrite phase. Magnetic evaluation of the specimens showed that the Nd0.01 doped sample with a quasi-spherical morphology and particle size of about 60 nm has the highest saturation magnetization of 50 emu/g and coercive force of 103 Oe.

We report a 33-month-old boy who presented to the emergency department with mild periumbilical abdominal pain lasting for 3 days. A plain abdominal radiograph showed 7 magnetic beads, which were located possibly in the small intestine without a free air. His parents bought neodymium magnetic beads 10 days before the onset of the symptom, and did not witness swallowing of the beads. Contrary to the radiographic finding, laparoscopic exploration showed several perforations in the small intestine and mesocolon. He was discharged uneventfully on postoperative day 5. Ingested magnetic beads should be considered as a cause if a child with abdominal pain recently obtained or played with the beads.

Promethium is one of the rare earth elements of Lanthanides. This element is no found on the earth’s crust. All its isotopes are radioactive. The isotope 147Pm is a pure beta emitter and very useful in industry because of its radioactive specifications. To name its applications one can point to usage as beta source in nuclear gauges, self-luminary lamps and nuclear batteries. This radioisotope produces via two methods, one from extraction of fission products waste and the second from thermal neutron irradiation of 146Nd. In this research, natural neodymium was irradiated in Tehran Research Reactor (TRR) and the gamma and beta spectrums were obtained. In addition, theoretical calculations were done. In this way, acceptable consistency in the results was obtained and the activity and radioactivity of the products were compared

Developing strategies for the green synthesis of novel materials, such as pigments for protection from solar radiation, is a fundamental research subject in material science to mitigate the heat island effect. Within this perspective, the current study reports on the synthesis of blue pigments of ZnAl2O4:M (M = Co2+ and Co2+/Nd3+) using recycled metallic aluminum (discarded can seal) with reflective properties of Near-infrared radiation. The pigments were characterized by XRD, SEM, XPS, UV-Vis, NIR diffuse reflectance spectroscopy, and CIE-1976 L*a*b* color measurements. The wettability of the coatings containing the synthesized pigments was also evaluated. The structural characterization showed that the pigments present the Gahnite crystalline phase. Colorimetric measurements obtained by the CIEL*a*b* method show values correlated to blue pigments attributed to Co2+ ions in tetrahedral sites. The pigments exhibit high near-infrared solar reflectance (with R% ≥ 60%), with an enhancement of nearly 20% for the pigment-containing neodymium when applied in white paint, indicating that the prepared compounds have the potential to be energy-saving color pigments for coatings.

NIR emitting OLEDs (organic light-emitting diodes) with high photoluminescence quantum yields were developed on the basis of fluorinated 1,3-diketonate coordination compounds of the Nd3+ ion. Both thermal evaporation and spin-coating techniques were successfully employed for active layer deposition resulting in electroluminescence quantum yields up to 1.38·10−2%. Blueish-green emission from exciplex and electroplax formations was almost suppressed with the topology optimization of the cell.

In the present work, the catalytic behavior of nickel-based catalysts supported on ceria/zirconia, undoped and doped with lanthanum and neodymium (3.5Ni/Ce0.8La0.5Nd0.2Zr0.13O2−x), was investigated under different reactions: steam reforming, partial oxidation and autothermal reforming of different fuels (methane, biogas, and propane). The catalytic properties of these catalysts were evaluated at a temperature of 800 °C, under atmospheric pressure, at GSHV = 120,000 h−1, using steam/carbon and oxygen/carbon ratio, respectively, of S/C = 2.5 and O/C = 0.5 and, in the case of autothermal conditions, with the addition of H2S (100 ppm) as a contaminant. Depending on the tested fuel, ATR, SR, and POX reactions over doped and undoped catalysts showed different results. In particular, the doped catalyst, due to neodymium and lanthanum doping, better distributed nickel species on the catalyst surface, promoting a higher concentration of defect groups and oxygen vacancies. This resulted in improved catalytic performance and resistance to deactivation. Endurance catalytic test also confirmed the beneficial effect of the doped catalysts.

Background: Gastric cancer (GC) is one of the common cancers that have a direct impact on the numerous facets of life. GC still remains a life threatening with one million mortalities per year worldwide. Objective: In this work, we planned to formulate the Neodymium/Zinc oxide nanocomposites by using the Avaram Senna flower extract (AS-Nd/ZnONCs) and examine its anticancer potential against the GC AGS cells via inhibition of PI3K/AKT/mTOR signaling pathway. Methodology: The developed AS-Nd/ZnONCs were characterized by various techniques like UV–vis spectroscopy, XRD, FE-SEM, EDAX, FT-IR, and photoluminescence studies. Antibacterial assay was performed by well diffusion method. The anticancer potential of AS-Nd/ZnONCs were investigated against AGS cells by MTT, ROS and MMP measurement, and apoptotic cell death using respective fluorescence staining techniques. The cell adhesion and antioxidants status were detected by standard method. The mRNA expression of PI3K/AKT/mTOR signaling molecules was studied via RT-PCR technique. Results: The formulated AS-Nd/ZnONCs exhibited the hexagonal wurtzite structure with 33.56 nm size. The outcomes of antibacterial assay proved that the AS-Nd/ZnONCs has remarkable antibacterial activity. The MTT assay evidenced that the AS-Nd/ZnONCs dose-dependently suppressed the AGS cell viability. Fluorescence staining results demonstrated that the AS-Nd/ZnONCs provoked the apoptotic cell death in AGS cells. AS-Nd/ZnONCs treatment effectively inhibited the PI3K/AKT/mTOR signaling cascade and triggered the apoptotic pathway in the AGS cells. Conclusion: In conclusion, our findings confirmed that the formulated AS-Nd/ZnONCs could be a hopeful chemopreventive agent in the future to treat the GC.

Antisolvent crystallization is a separation technology that separates the solute from the solvent by the addition of another solvent, in which the solute is sparingly soluble. High yields are achieved by using higher antisolvent-to-aqueous ratios, but this generates higher supersaturation, which causes excessive nucleation. This results in the production of smaller particles, which are difficult to handle in downstream processes. In this work, the effect of varying the organic (antisolvent)-to-aqueous (O/A) ratio and seed loading on the yield, particle size distribution, and morphology of neodymium sulphate product, during its recovery from an aqueous leach solution using antisolvent crystallization, was investigated. A batch crystallizer was used for the experiments, while ethanol was used as an antisolvent. Neodymium sulphate octahydrate [Nd2(SO4)3.8H2O] seeds were used to investigate the effect of seed loading. It was found that particle sizes increased as the O/A ratio increased. This was attributed to the agglomeration of smaller particles that formed at high supersaturation. An O/A ratio of 1.4 resulted in higher yields and particles with a plate-like morphology. The increase in yield was attributed to the increased interaction of ethanol molecules with the solvent, which reduced the solubility of neodymium sulphate. Increasing the seed loading resulted in smaller particle sizes with narrow particle size distribution and improved filtration performance. This was attributed to the promotion of crystal growth and suppression of agglomeration in the presence of seeds.

This study examines the synthesis of two geminal bisphosphonate ester-supported Ln3+ complexes [Ln(L3)2(NO3)3] (Ln = Nd3+ (5), La3+ (6)) and optical properties of the neodymium(III) complex. These results are compared to known mono-phosphonate ester-based Nd3+ complexes [Nd(L1/L2)3X3]n (X = NO3−, n = 1; Cl−, n = 2) (1–4). The optical properties of Nd3+ compounds are determined by micro-photoluminescence (µ-PL) spectroscopy which reveals three characteristic metal-centered emission bands in the NIR region related to transitions from 4F3/2 excited state. Additionally, two emission bands from 4F5/2, 2H9/2 → 4IJ (J = 11/2, 13/2) transitions were observed. PL spectroscopy of equimolar complex solutions in dry dichloromethane (DCM) revealed remarkably higher emission intensity of the mono-phosphonate ester-based complexes in comparison to their bisphosphonate ester congener. The temperature-dependent PL measurements enable assignment of the emission lines of the 4F3/2 → 4I9/2 transition. Furthermore, low-temperature polarization-dependent measurements of the transitions from R1 and R2 Stark sublevel of 4F3/2 state to the 4I9/2 state for crystals of [Nd(L3)2(NO3)3] (5) are discussed.

This collection presents data on neodymium isotopes from modern dental elements (third molars) of 47 individuals born and raised in the Netherlands, Grenada, Curaçao, Bonaire, Columbia and Iceland. Neodymium isotope composition was successfully analyzed for 40 individuals (ranging between 0.511820 and 0.512773 143Nd/144Nd and -16.0 to 2.6 εNd), with neodymium concentration data available for 23 individuals (ranging between 0.1 and 21.0 ppb). For 37 individuals the dental elements have also been analyzed for strontium isotopes. All analyses were performed on a Thermo Scientific Triton Plus TIMS. Neodymium analyses were performed using 1013 Ω resistors, with samples reanalyzed using 1011 Ω resistors if enough sample was available. Strontium analyses were performed using 1011Ω resistors. A discussion about the applicability of the analysis technique and the results can be found in the article “Evaluation of neodymium isotope analysis of human dental enamel as a provenance indicator using 1013 Ω amplifiers (TIMS)”. This dataset is available for verification of the provenance capability of neodymium isotope analysis in archaeological and forensic mobility studies. To ensure the interoperability and reusability of the data, the data is available on the IsoArcH (https://isoarch.eu/) data repository.

The deployment of renewable energy technologies will play a crucial role in the global transition to a low-carbon economy and ultimately in the fight against global warming. However, this transition could face important problems because most of those technologies rely on the steady supply of critical minerals. Colombia, thanks to its hydrological resources, has relied on the hydro­power for electricity generation. However, the government has implemented measures to back-up the energy system in draught periods and, consequently, fossil fuels-based plants have increased the market share and with these, CO2 emissions. This study assesses the mineral demand in Colombia in the period 2020-2050 for the rare earth elements embedded in the deployment of wind power technologies in four different climate policy scenarios in order to establish whether they could face geological bott­lenecks that could ultimately hamper the transition to a low-carbon economy. The Gigawatts (GW) of future capacity additions in the energy system are converted into tons of metal using published metal intensities of use and assumptions of Colombia’s technological pathway. Then, the cumulated mineral demand is compared against current mining production rates and geological reserves to establish geological bottlenecks. The results show that the reserves will not pose any threat to its transition. However, when compared to current mining rates, the mineral demand in 2050 could pose a problem for the supply of minerals. Finally, this study gives some policy recommendations that could be used to mitigate these issues, such as substitution, improved circular economy and sound technological choices.

A recent increase in the importance of Rare Earth Elements (REEs), proportional to advancements in modern technology, green energy, and defense, has urged researchers to look for more sophisticated and efficient exploration methods for their host rocks, such as carbonatites. Hyperspectral remote sensing has long been recognized as having great potential to identify the REEs based on their sharp and distinctive absorption features in the visible near-infrared (VNIR) and shortwave infrared (SWIR) electromagnetic spectral profiles. For instance, neodymium (Nd), one of the most abundant Light Rare Earth Elements (LREEs), has among the most distinctive absorption features of REEs in the VNIR part of the electromagnetic spectrum. Centered at ~580, ~745, ~810, and ~870 nm in the VNIR, the positions of these absorption features have been proved to be independent of the mineralogy that hosts Nd, and the features can be observed in samples as low in Nd as 1000 ppm. In this study, a neodymium index (NI) is proposed based on the 810 nm absorption feature and tested on the hyperspectral images of the Sillai Patai carbonatite samples to identify Nd pixels and to decipher the relative concentration of Nd in the samples based on the depth of the absorption feature. A preliminary spectral study of the carbonatite samples was carried out using a spectroradiometer to determine the presence of Nd in the samples. Only two of the absorption features of Nd, centered at ~745 and ~810 nm, are prominent in the Nd-rich samples. The other absorption features are either weak or suppressed by the featureless spectra of the associated minerals. Similar absorption features are found in the VNIR and SWIR images of the rock samples captured by the laboratory-based hyperspectral cameras that are processed through Minimum Noise Fraction (MNF) and Fast Fourier Transform (FFT) to filter the signal and noise from the reflectance data. An RGB false-color composite of continuum-removed VNIR reflectance bands covering wavelengths of 587.5, 747.91, and 810.25 nm efficiently displayed the spatial distribution of Nd-rich hotspots in the hyperspectral image. The depth of the 810 nm absorption feature, which corresponds to the concentration of Nd in a pixel, is comparatively greater in these zones and is quantified using the proposed NI such that the deeper the absorption feature, the higher the NI. To quantify the Nd-rich pixels in the continuum-removed VNIR images, different threshold values of NI are introduced into a decision tree classifier which generates the number of pixels in each class. The strength of the proposed NI coupled with the decision tree classifier is further supported by the accuracy assessment of the classified images generating the Kappa coefficient of 0.82. Comparing the results of the remote sensing data obtained in this study with some of the previously published studies suggests that the Sillai Patti carbonatite is rich in Nd and associated REEs, with some parts of the samples as high in Nd concentration as 1000 ppm.

Purpose: Foreign body ingestion is common in children, and most foreign bodies pass spontaneously without causing serious injuries. Ingestion of multiple high-power magnet pieces is unique and increases the risk of morbidity and mortality. The longer the duration of ingestion, the increased likelihood of complications. Various management options have been reported, and there is no consensus on the ideal management which necessitates the need for a practical algorithm. The incidence of magnet ingestion has been increasing and directly related to the laws and recalls. The aim of this review is to provide an easy and practical pathway for management and to highlight the preventive rules of the legislations and recalls.Methods: PubMed/MEDLINE, the Cochrane Database of Systematic Reviews, and the list of references from all identified complete publications were searched for all publications in English-language for pediatric magnet ingestion.Conclusion: Practical and time-saving management pathways are recommended to minimize the risk of complications. Preventive rules and recalls are important for eliminating the availability of these hazardous magnets. Public awareness about the unique risks posed by these magnets if ingested is important.

This study aimed to develop the liquid-liquid equilibrium models to predict neodymium (Nd) and yttrium (Y) distribution in the extraction system. Feed solution (solution of Nd and Y in the 1 M nitric acid media) was mixed with solvent (di-2-ethyl-hexyl-phosphate (D2EHPA) diluted in kerosene) with volume ratio of 1:1 using a mechanical shaker for 25 min. The solution was settled to separate the aqueous and organic phase. Neodymium and yttrium concentrations in the aqueous phase were analyzed by using X-Ray Fluorescence - Ortec 7010 with Am 241. Meanwhile, the concentration of Nd and Y in the organic phase were evaluated by using mass balance. The results showed that the separation of Y from Nd was successfully carried out using 0.30 M D2EHPA diluted in kerosene. The Y extraction efficiency of 93% was obtained. To predict Nd and Y distributions, two mathematical equilibrium models were formulated: (i) the stoichiometric model derived from the reaction mechanism by considering the available reaction coefficients and (ii) the non-stoichiometric model is proposed to obtain approximate equilibrium data of Nd – Y extraction. The models were validated using experimental data. Neodymium and yttrium equilibrium distribution with D2EHPA as the solvent was better approximated using the non-stoichiometric than the stoichiometric equilibrium model as shown by the lower of mean relative errors.

In recent decades, extensive research has been done on substrates (i.e., titanium and carbon) with lead dioxide coating to design a cheap anode in electrochemical systems instead of a platinized (Pt) electrode. Various factors can affect the structure and catalytic activity of lead dioxide coating. The most important of them are the type of substrate, how to prepare the substrate for the coating process and the types of lead dioxide additives. In this work, the effective factors in the preparation of the substrate were first investigated. Subsequently, the effect of neodymium as an additive on the catalytic activity of the electrode was studied. We prepared these electrodes and they were first evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD) spectrometer, voltammetry and electrochemical impedance spectrometer (EIS). The results showed that the potential of water oxidation on the modified $Pb{O}_{2\,}$ electrodes by neodymium was 2 V. Here, we used an electrochemical method to prepare perchlorate. Since the anode potential for perchlorate oxidation is near that for water oxidation, conventional electrodes can’t be used in the perchlorate electrosynthesis. To achieve high production yield in the preparation of perchlorate from chlorate, various parameters including pH, time, and current density were optimized by the Box-Behnken design of the experiment method. The optimal values for this process were obtained at pH = 11, temperature 40 °C and current density of 0.5 mA cm ^−2 . The results at the optimal condition showed that the perchlorate production yield by modified $Pb{O}_{2\,}$ electrodes was 80% in the 300 min. This value was only 60% for the unmodified $Pb{O}_{2\,}$ electrode.

BACKGROUND Determination of strontium (Sr) and neodymium (Nd) isotopic composition in geological samples by Multi-collector Inductively Coupled Plasma-Mass Spectrometry (MC-ICP-MS) needs a lengthy and complex chemical preparation procedure. Moreover, samples cannot be dissolved completely. OBJECTIVES To effectively digest samples and eliminate interferences from the experimental process. METHODS Geological samples were dissolved by microwave digestion. The processes of Sr, Nd chemical separation and mass spectrometry analyses were studied. In particular, the recovery and memory effect of resin column were investigated. RESULTS The research shows that after ten times usages Sr and Nd procedure, blanks of the resin are less than 1.0 ng. However, the recovery decreases significantly from 98% to 20% and 90% to 50%, respectively. If the analyzed samples contain low concentrations of Sr and Nd, which are insufficient for mass spectrometry analysis, it is suggested that Sr special effect resin should be used no more than 5 times and AG50W-X8 and Ln resin should be used no more than 10 times. The entire procedure is applied in the separation of Sr and Nd of international standard geological samples (BCR-2, W-2a, BHVO-2, AGV-2). The acquired 87Sr/86Sr and 143Nd/144Nd ratios are consistent with those in the literature, and the instrumental internal precision 2SE (n=50) and methodological external precision 2SD (n=6) are better than 0.0015%. CONCLUSIONS The proposed method meets the requirement of high-precision measurement of Sr and Nd isotopic composition in geological samples.

LaF3:Nd3+ (core), LaF3:Nd3+@LaF3 (core/shell) and LaF3:Nd3+@LaF3@SiO2 (core/shell/SiO2) nanoparticles (NPs) were designed and synthesized at low temperature. The structure and morphology of the as-prepared nanoproducts were characterized by X-ray diffraction and transmission electron microscopy (TEM) techniques. Thermal analysis and FTIR spectral studies were conducted to examine the surface properties of the nanomaterials. The as-prepared LaF3:Nd3+ NPs exhibited hexagonal structure and were composed of monodispersed irregularly and spherically shaped NPs with average grain size of 21 nm. TEM image showed the successful silica surface coating, which was verified by FTIR spectral analysis. The emission spectra of LaF3:Nd3+ NPs was obtained by monitoring the emission of Nd3+ at 325 nm (Cd laser) where it exhibited the characteristic 4f→4f transitions lines originating from the Nd 4f3 configuration. Under UV light irradiation, the emission spectra revealed various strong emission transitions which were greatly affected by the surrounding silica surface coating. These observed results suggested future applications in biolabeling and light-emitting diode.