Health & Environmental Research Online (HERO)


Vanadium Compounds - Problem Formulation


26,512 References Were Found:

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Oxidation of Benzoin Catalyzed by Oxovanadium(IV) Schiff Base Complexes

Authors: Alsalim, TA; Hadi, JS; Ali, ON; Abbo, HS; Titinchi, SJ (In Press) Chemistry Central Journal. HERO ID: 1500952

[Less] ABSTRACT: BACKGROUND: The oxidative transformation of benzoin to benzil has been accomplished by the . . . [More] ABSTRACT: BACKGROUND: The oxidative transformation of benzoin to benzil has been accomplished by the use of a wide variety of reagents or catalysts and different reaction procedures. The conventional oxidizing agents yielded mainly benzaldehyde or/and benzoic acid and only a trace amount of benzil. The limits of practical utilization of these reagents involves the use of stoichiometric amounts of corrosive acids or toxic metallic reagents, which in turn produce undesirable waste materials and required high reaction temperatures.In recent years, vanadium complexes have attracted much attention for their potential utility as catalysts for various types of reactions. RESULTS: Active and selective catalytic systems of new unsymmetrical oxovanadium(IV) Schiff base complexes for the oxidation of benzoin is reported. The Schiff base ligands are derived between 2-aminoethanol and 2-hydroxy-1-naphthaldehyde (H2L1) or 3-ethoxy salicylaldehyde (H2L3); and 2-aminophenol and 3-ethoxysalicylaldehyde (H2L2) or 2-hydroxy-1-naphthaldehyde (H2L4). The unsymmetrical Schiff bases behave as tridentate dibasic ONO donor ligands. Reaction of these Schiff base ligands with oxovanadyl sulphate afforded the mononuclear oxovanadium(IV) complexes (VIVOLx.H2O), which are characterized by various physico-chemical techniques.The catalytic oxidation activities of these complexes for benzoin were evaluated using H2O2 as an oxidant. The best reaction conditions are obtained by considering the effect of solvent, reaction time and temperature. Under the optimized reaction conditions, VOL4 catalyst showed high conversion (>99 %) with excellent selectivity to benzil (~100 %) in a shorter reaction time compared to the other catalysts considered. CONCLUSION: Four tridentate ONO type Schiff base ligands were synthesized. Complexation of these ligands with vanadyl(IV) sulphate leads to the formation of new oxovanadium(IV) complexes of type VIVOL.H2O.Elemental analyses and spectral data of the free ligands and their oxovanadium(IV) complexes were found to be in good agreement with their structures, indicating high purity of all the compounds.Oxovanadium complexes were screened for the oxidation of benzoin to benzil using H2O2 as oxidant. The effect of time, solvent and temperature were optimized to obtain maximum yield. The catalytic activity results demonstrate that these catalytic systems are both highly active and selective for the oxidation of benzoin under mild reaction conditions.

Journal Article
Journal Article

Search for New Catalysts for the Oxidation of SO2

Authors: Loskyll, J; Stöwe, K; Maier, WF (In Press) . HERO ID: 1935413

[Less] The focus of this paper is the search and characterization of novel catalysts for the gas phase oxidation . . . [More] The focus of this paper is the search and characterization of novel catalysts for the gas phase oxidation of concentrated SO2 for the production of sulfuric acid. Modern high-throughout (HT) methods such as emissivity corrected Infrared Thermography (ecIRT) and automated synthesis techniques were used for the synthesis and activity measurements of the samples. In addition a plug flow reactor that uses UV-vis online analytics for the quantification of the SO2 conversion was designed, built and used for validation of the HT results. The study started with a highly diverse search space of elemental compositions designed for potential discovery. About a thousand samples were synthesized using sol-gel recipes and screened for catalytic SO2 oxidation activity over a temperature range of 330-450 °C. Several novel catalyst systems were discovered during the screening process and the most interesting systems were further characterized. The most important doping effects on activity found were the influence of bismuth and selenium doping on standard sulfuric acid catalysts, the activity gain of chromium based catalysts caused by the doping with antimony and the activity gain of chromium as well as iron and vanadium based catalysts caused by the doping with tin.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation

Authors: Natalio, F; André, R; Hartog, AF; Stoll, B; Jochum, KP; Wever, R; Tremel, W (In Press) Nature Nanotechnology. HERO ID: 1256771

[Less] Marine biofouling-the colonization of small marine microorganisms on surfaces that are directly exposed . . . [More] Marine biofouling-the colonization of small marine microorganisms on surfaces that are directly exposed to seawater, such as ships' hulls-is an expensive problem that is currently without an environmentally compatible solution. Biofouling leads to increased hydrodynamic drag, which, in turn, causes increased fuel consumption and greenhouse gas emissions. Tributyltin-free antifouling coatings and paints based on metal complexes or biocides have been shown to efficiently prevent marine biofouling. However, these materials can damage the environment through metal leaching (for example, of copper and zinc) and bacteria resistance. Here, we show that vanadium pentoxide nanowires act like naturally occurring vanadium haloperoxidases to prevent marine biofouling. In the presence of bromide ions and hydrogen peroxide, the nanowires catalyse the oxidation of bromide ions to hypobromous acid (HOBr). Singlet molecular oxygen ((1)O(2)) is formed and this exerts strong antibacterial activity, which prevents marine biofouling without being toxic to marine biota. Vanadium pentoxide nanowires have the potential to be an alternative approach to conventional anti-biofouling agents.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Twenty-four-hour urinary trace element excretion: Reference intervals and interpretive issues

Authors: Sieniawska, CE; Jung, LC; Olufadi, R; Walker, V (In Press) Annals of Clinical Biochemistry. HERO ID: 1015724

[Less] BACKGROUND: Introduction of inductively coupled plasma mass spectrometry (ICP-MS) into clinical laboratories . . . [More] BACKGROUND: Introduction of inductively coupled plasma mass spectrometry (ICP-MS) into clinical laboratories has led to an increasing application of analyses to risk assessment for toxicity from environmental exposure to trace elements, and in occupational monitoring. Interpretation of results from random urine samples may be problematic and measurement of excretion over 24 h is sometimes preferable. Recent reference data are sparse. METHODS: Twenty-four-hour urine samples from 111 healthy adults from the renal stones clinic in Southampton, UK, were analysed for 31 trace elements using ICP-MS and for zinc using atomic absorption spectroscopy. Non-parametric 0.95 coverage intervals were determined for trace element excretion per 24 h and as a ratio to creatinine, for the full study cohort and separately for men (n = 77) and women (n = 34). RESULTS: Beryllium was undetectable in 95% of samples, bismuth in 87% and uranium in 75%. In comparison with published ranges, reference intervals for this cohort were higher for molybdenum, tin and vanadium, and for arsenic due to inclusion of fish arsenicals. Aluminium, chromium, iron, lead and mercury were lower. In our cohort, 24-h excretion of 17 elements was significantly higher in men than in women. However, when expressed as trace element to creatinine ratios, the situation reversed strikingly. Because of their lower creatinine excretion, ratios for 18 elements were significantly higher for women. CONCLUSIONS: New adult reference intervals were obtained for 24-h urine trace element excretion. Trace element:creatinine ratios must be used cautiously, with separate ranges for men and women.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Removing arsenic and co-occurring contaminants from drinking water by full-scale ion exchange and point-of-use/point-of-entry reverse osmosis systems

Authors: Chen, ASC; Wang, L; Sorg, TJ; Lytle, DA (2020) Water Research 172:115455. HERO ID: 6307911

[Less] This study investigated the performance of two full-scale ion exchange (IX) systems, one point-of-entry . . . [More] This study investigated the performance of two full-scale ion exchange (IX) systems, one point-of-entry (POE) reverse osmosis (RO) system and nine point-of-use (POU) RO units for simultaneous removal of arsenic and several co-occurring contaminants from drinking water. The study was performed as part of the U.S. Environmental Protection Agency's Arsenic Treatment Demonstration Program. The IX systems, with strong base anionic (SBA) resins, effectively removed arsenic (As), nitrate (NO3-) and uranium (U) to below respective maximum contaminant levels and vanadium (V) and molybdenum (Mo) to below 2 μg/L. The useful run length, as determined by either 10-mg/L (as N) nitrate or 10-μg/L arsenic breakthrough, was approximately 400 bed volumes (BV) initially. However, it was decreased over time, e.g., by 15% in 13 months at one site and 33% in 7 months at another site, apparently caused by resin fouling due to the presence of 2-mg/L natural organic matter (NOM) in source waters. The use of dual resins ‒ an acrylic SBA resin underlain by a polystyrene SBA resin ‒ effectively removed NOM and allowed the system to perform at its baseline level through the 13-month study. Arsenic and nitrate peaking occurred when the resins were not regenerated timely. The removal of contaminants appeared to follow a selectivity sequence: U, Mo > V > SO42- > HAsO42- > NO3- > HCO3-. RO effectively removed arsenic, nitrate, antimony, uranium and vanadium, mostly with a >99% rejection rate. The POE RO coupled with dual plumbing (only treating a fraction of water for potable use) and POU RO in individual homes could be used as low-cost alternatives to traditional RO treatment.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Toxic mineral elements in Mytilus galloprovincialis from Sicilian coasts (Southern Italy)

Authors: Cammilleri, G; Galluzzo, P; Pulvirenti, A; Giangrosso, IE; Lo Dico, GM; Montana, G; Lampiasi, N; Mobilia, MA; Lastra, A; Vazzana, M; Vella, A; La Placa, P; Macaluso, A; Ferrantelli, V (2020) Natural Product Research 34:177-182. HERO ID: 6308364

[Less] We assessed the relationship between V, Cr, Mn, Hg, As, Cd, Sn, Sb and Pb concentrations in Mytilus . . . [More] We assessed the relationship between V, Cr, Mn, Hg, As, Cd, Sn, Sb and Pb concentrations in Mytilus galloprovincialis samples from the coasts of Sicily and the expression of metallothioneins. Toxic mineral elements assessment was carried out by A.A. Spectrometry and ICP-MS. The metallothioneins expression was performed by q-PCR method. Low metals' levels were found in the mussel samples examined, in comparison with what was reported in literature. The highest mean values of toxic mineral elements were found in Gela (Cr 0.178 ± 0.03 mg/Kg, Mn 4.325 ± 0.012 mg/Kg, As 3.706 ± 0.009 mg/Kg, Sn 0.148 ± 0.014 mg/Kg, Sb 0.009 ± 0.004 mg/Kg e Pb 0.364 ± 0.01 mg/Kg). Significant levels of Hg were found in samples from Catania (0.014 ± 0.005 mg/Kg). Only vanadium and lead concentrations showed significant differences between sampling areas (p < 0.05). Molecular analysis verified a basal expression of Mt1 and the absence of over-expression of Mt2, confirming the low mineral's concentrations found in the samples examined.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Clear evidence for element partitioning effects in a Ti-6Al-4V alloy by the first-principles phase field method

Authors: Pham Thi, N; Ohno, K; Sahara, R; Kuwahara, R; Bhattacharyya, S (2020) HERO ID: 6308392

[Less] Ti-6wt%Al-4wt%V (Ti64) is an α +β titanium alloy, in which the alloying components strongly affect the . . . [More] Ti-6wt%Al-4wt%V (Ti64) is an α +β titanium alloy, in which the alloying components strongly affect the mechanical properties. In this report, element partitioning effects in Ti64 are investigated by using the first-principles phase field (FPPF) method, which has recently been proposed by our group. In the FPPF method, the local free energy is calculated using cluster expansion method in combination with density functional theory and the temperature effect is incorporated using potential renormalization theory. We have succeeded in identifying enrichment of Al (V) in the α (β) phase, i.e., the clear evidence for the element partitioning effects of Al and V, without using any thermodynamical parameter. The transformation of the β phase and the α phase in microstructure is investigated by varying the V and Al concentration by a small amount. Our results are in excellent agreement with the recent experimental results, showing the validity of the FPPF method for ternary alloys.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

In situ synthesis of core-shell vanadium nitride@N-doped carbon microsheet sponges as high-performance anode materials for solid-state supercapacitors

Authors: Jia, H; Cai, Y; Li, S; Zheng, X; Miao, L; Wang, Z; Qi, J; Cao, J; Feng, J; Fei, W (2020) Journal of Colloid and Interface Science 560:122-129. HERO ID: 6308393

[Less] Vanadium nitride (VN) with high conductivity exhibits the potential promising as anode materials for . . . [More] Vanadium nitride (VN) with high conductivity exhibits the potential promising as anode materials for supercapacitors, but VN suffered the obvious performance fading due to the dissolution of VN in aqueous electrolyte. In this work, we solve these problems through realizing 3D structural VN microsheets shelled with N-doped carbon layer (VN@NC) by introducing melamine as nitrogen source and PVP as carbon source. The as-prepared VN@NC electrode display high capacitance of 368 F g-1 and good rate property. A solid-state asymmetric supercapacitor (ASC) with NiCo2O4 nanowires as cathode materials and VN@NC as anode materials was fabricated. The ASC device exhibits the high energy density of 65.3 W h kg-1, and good cycling stability (92% capacitance retention) after 4000 cycles. Moreover, the ASC device shows good mechanical flexibility with negligible capacitance loss after 1000 bending cycles.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

The deposition of VWOx on the CuCeOy microflower for the selective catalytic reduction of NOx with NH3 at low temperatures

Authors: Niu, C; Wang, Y; Ren, D; Xiao, L; Duan, R; Wang, B; Wang, X; Xu, Y; Li, Z; Shi, JW (2020) Journal of Colloid and Interface Science 561:808-817. HERO ID: 6308396

[Less] NOx emissions are a major environmental problem, and the selective catalytic reduction (SCR) is the . . . [More] NOx emissions are a major environmental problem, and the selective catalytic reduction (SCR) is the most effective method to convert NOx in flue gas into harmless N2 and H2O. In this work, a new carrier, CuCeOy microflower assembled from a large number of copper-cerium mixed oxide nanosheets, is firstly developed to load vanadium-tungsten mixed oxides (VWOx) for the SCR of NOx with NH3. The resultant optimal VWOx/CuCeOy catalyst exhibits significantly enhanced low-temperature de-NOx performance with the NOx conversion of 60% at 180 °C, over 90% from 240 °C to 390 °C under the gas hourly space velocity (GHSV) of 36,000 h-1. The reason can be mainly attributed the fact that the transfer of electrons among Ce, Cu and V ions is very easy to occur via the following equations Ce3++Cu2+ ↔ Ce4++Cu+, V5+ + Cu+ ↔ V4+ + Cu2+, V4+ + Ce4+ ↔ V5+ + Ce3+, which effectively decreases the apparent activation energy (Ea = 16.59 kJ/mol) of NH3-SCR de-NOx reaction. In addition, the enhanced reducibility and a large number of Brønsted acid sites also contribute the low-temperature de-NOx performance. Both Eley-Rideal and Langmuir-Hinshelwood mechanisms are included in the NH3-SCR de-NOx reaction over the VWOx/CuCeOy catalyst.

The "refereed" or "peer review" status of a journal comes from the Ulrichsweb Global Serials Directory (http://ulrichsweb.serialssolutions.com/), as supplied by the publisher. The term refers to the system of critical evaluation of manuscripts/articles by professional colleagues or peers. The content of refereed publications is sanctioned, vetted, or otherwise approved by a peer-review or editorial board. The peer-review and evaluation system is utilized to protect, maintain, and raise the quality of scholarly material published in serials. Publications subject to the referee process are assumed, then, to contain higher quality content than those that are not.
Peer Reviewed Journal Article

Bidirectional Current Triggering in VO₂-Based Device with High-Repetition-Rate Pulse Beams Using Near-Infrared Laser Diode

Authors: Kim, J; Choi, S; Lee, SL; Kim, MS; Kim, DK; Kim, BJ; Lee, YW (2020) Journal of Nanoscience and Nanotechnology 20:351-358. HERO ID: 6308403

[Less] Here we report bidirectional current triggering (BCT) with a high repetition rate, achieved in a twoterminal . . . [More] Here we report bidirectional current triggering (BCT) with a high repetition rate, achieved in a twoterminal planar device based on a vanadium dioxide (VO₂) thin film by using a laser diode with a center wavelength of 976 nm as an excitation source. The VO₂ thin film was grown on a sapphire (Al₂O₃) substrate using a pulsed laser deposition method, and the two-terminal planar device was fabricated by sawing the grown film into microscale unit devices, each of which was then attached onto a printed circuit board. Current triggering was performed by controlling the output power of the laser beam incident on the device surface. The proposed device allows stable current triggering operation even with laser pulses of higher repetition rate and lower energy because it is designed to have low heat capacity and thermal conductivity. Experimental results showed that a BCT of up to 30 mA was achieved at the maximum repetition rate of 8.0 Hz. The switching contrast between off- and on-state currents was calculated to be ~7295, and average rising and falling times of the current triggering were measured to be ~18.3 and ~22.5 ms, respectively.