Search

BACKGROUND: Understanding the effect of ions on collector generation characteristics is crucial for adjusting the oil/water interface and enhancing mineral flotation. METHODS: We conducted a study of the kerosene droplet generation process in the presence of NaCl, MgCl2, and AlCl3 using a high‐speed motion acquisition system. RESULTS AND CONCLUSIONS: The results showed that the generation process of kerosene droplets could be divided into two stages, droplet expansion and column contraction, according to variations of the droplet width. With the increasing capillary inner diameter, the generation time of the kerosene droplet increased, while the w/h value (column width/column height) of the kerosene column decreased. When the w/h value decreased to 0, the droplet column ruptured, and the droplet separated from the capillary. As the ion valence increased, the equivalent diameter (d) of the kerosene droplet increased due to the ionic hydration and followed the order dAl3+ > dMg2+ > dNa+. Furthermore, as the ion concentration increased, the equivalent diameter increased with the same capillary inner diameter, and the w/h value decreased. A model of the kerosene column height and capillary inner diameter (R) was established to predict the characteristics of the generated kerosene droplet. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Quinoxaline (Q) is an excellent candidate for anolyte active materials in nonaqueous redox flow batteries (NRFBs) because of its high solubility, low‐reaction potential, and two transfer electrons in organic solvents. However, systematic and in‐depth studies on the electrochemical performance of Q under nonaqueous conditions are still needed. Herein, a systematical study is conducted on the effect of ion species on Q reaction in nonaqueous solvent acetonitrile through a combination of electrochemical measurements and theoretical analysis. In accordance with the rotating disk electrode analysis, the diffusion coefficients of Q under Na+ and tetrabutylammonium (TBA)+ conditions reach 5.031 × 10−6 and 8.563 × 10−6 cm2 s−1, respectively, and the kinetic rate constants are 7.81 × 10−3 and 4.76 × 10−3 cm s−1, respectively. According to in situ UV–vis analysis, Q presents the best electrochemical reversibility under tetrabutylammonium hexafluorophosphate (TBAPF6) and a low‐reaction potential of −1.98 V versus Ag/Ag+, making it a very promising anolyte active material. By coupling with the 1,4‐di‐tert‐butyl‐2,5‐bis (2‐methoxyethoxy)benzene (DBBMEB) catholyte, the DBBMEB‐Q NRFB, which the battery voltage reaches above 2.5 V under both Na+ and TBA+ conditions, is demonstrated. The methodology adopted in this work provides a design method for the high‐voltage and high‐energy‐density redox flow batteries. [ABSTRACT FROM AUTHOR]

A large amount of cyanide-containing wastewater is discharged during electrode material synthesis. Among them, cyanides will form metal–cyanide complex ions which possess high stability, making it challenging to separate them from these wastewaters. Therefore, it is imperative to understand the complexation mechanism of cyanide ions and heavy metal ions from wastewater in order to obtain a deep insight into the process of cyanide removal. This study employs Density Functional Theory (DFT) calculations to reveal the complexation mechanism of metal–cyanide complex ions formed by the interaction of Cu+ and CN− in copper cyanide systems and its transformation patterns. Quantum chemical calculations show that the precipitation properties of Cu(CN)43− can assist in the removal of CN−. Therefore, transferring other metal–cyanide complex ions to Cu(CN)43− can achieve deep removal. OLI studio 11.0 analyzed the optimal process parameters of Cu(CN)43− under different conditions and determined the optimal process parameters of the removal depth of CN−. This work has the potential to contribute to the future preparation of related materials such as CN− removal adsorbents and catalysts and provide theoretical foundations for the development of more efficient, stable, and environmentally friendly next-generation energy storage electrode materials. [ABSTRACT FROM AUTHOR]

Using measurements from the Mars Atmosphere and Volatile EvolutioN mission, we investigate the densities of H+ (nH+ ${n}_{{\mathrm{H}}^{+}}$), O+ (nO+ ${n}_{{\mathrm{O}}^{+}}$), and O2+ (no2+ ${n}_{{\mathrm{o}}_{2}^{+}}$), respectively, in the Martian magnetotail current sheet. We find that the current sheet when it is closer to the terminator than 0.75 Mars radii is mostly dominated by heavy ions ((nO++no2+ ${n}_{{\mathrm{O}}^{+}}+{n}_{{\mathrm{o}}_{2}^{+}}$)>2 nH+ ${n}_{{\mathrm{H}}^{+}}$), regardless of the variation of the upstream solar wind, but that it is sometimes dominated by H+ (nH+ ${n}_{{\mathrm{H}}^{+}}$ >2(nO++no2+ ${n}_{{\mathrm{O}}^{+}}+{n}_{{\mathrm{o}}_{2}^{+}}$)) at downstream distances exceeding 0.75 Mars radii. The occurrence rate of the dominant H+ weakly increases (and that of the heavy ions decreases) with solar wind density and dynamic pressure. Our results suggest that solar wind protons could enter the Martian tail and may become the dominant ion species in the current sheet, particularly when the solar wind density or dynamic pressure is high. Plain Language Summary: The current sheet of the Martian magnetotail is a major channel for the escape of planetary ions. The ion composition in the current sheet is essential to our understanding of this escape, as well as the magnetotail plasma dynamics. Our current knowledge, however, is poor. Based on the measurements of the ion density of different species in the current sheet from the Mars Atmosphere and Volatile EvolutioN spacecraft, we report that the current sheets we have surveyed are dominated by either the heavy ions from the planet or H+ (mostly) from the solar wind. We find that the downstream distance and the variation of the upstream solar wind are the two key factors that account for which ion species dominates in the tail current sheet. Key Points: Current sheets are mostly dominated by heavy ions but are sometimes dominated by H+ at the downstream distance exceeding 0.75 Mars radiiThe occurrence rate of current sheets with dominant H+ (heavy ions) weakly increases (decreases) with solar wind density and dynamic pressureOur results suggest that the dominant H+ in the current sheet could originate from solar wind [ABSTRACT FROM AUTHOR]

• Explore the influence of various factors on the spectral behavior of polyacrylamide. • Evidence of polymer spectral variation, hydrodynamic radius and scanning electron microscopy. • The microscopic mechanism of polyacrylamide viscosity change is proposed from the perspective of molecular structure. The viscosity reduction mechanism of a polymer aqueous solution for oil displacement affected by factors such as salinity, cation type, iron ion and temperature need to be further elucidated. The functional group absorbance of polyacrylamide was determined by ultraviolet spectrophotometry. The spectral behavior of polyacrylamide was analyzed from the perspective of molecular structure, and the microscopic level of its viscosity was explored. The results show that the absorbance of the polymer is affected by the valence of the cation in the order of Fe2+ > Fe3+ > Al3+ > Mg2+ > Ca2+ > K+ > Na+. Anion has no effect on the viscosity of polyacrylamide. With the increase of temperature, the absorbance and viscosity of polymer solution decreased. This paper investigated the effects of salinity, cation type, iron ion concentration and temperature on the spectral behavior of polyacrylamide. It was found that the decrease of absorbance was consistent with the change of molecular conformation. The decrease in amide groups in polymer solution leads to a decrease in solution absorbance, while the increase in amide groups leads to an increase in solution absorbance. Therefore, the conformational changes of polyacrylamide molecular chains can be determined by amide groups. The UV spectrum of polymers can provide a theoretical basis for the study of viscosity reduction mechanism. The ultraviolet spectrophotometry is simple and intuitive, which provides guidance for the selection of oil displacement polymer and the research and development of high-performance polymer. [ABSTRACT FROM AUTHOR]

Abstract Using measurements from the Mars Atmosphere and Volatile EvolutioN mission, we investigate the densities of H+ (nH+), O+ (nO+), and O2+ (no2+), respectively, in the Martian magnetotail current sheet. We find that the current sheet when it is closer to the terminator than 0.75 Mars radii is mostly dominated by heavy ions ((nO++no2+)>2 nH+), regardless of the variation of the upstream solar wind, but that it is sometimes dominated by H+ (nH+ >2(nO++no2+)) at downstream distances exceeding 0.75 Mars radii. The occurrence rate of the dominant H+ weakly increases (and that of the heavy ions decreases) with solar wind density and dynamic pressure. Our results suggest that solar wind protons could enter the Martian tail and may become the dominant ion species in the current sheet, particularly when the solar wind density or dynamic pressure is high.

[Display omitted] • Al3+can enhance chemical adsorption between sodium alginate and calcite surface. • The synergistic effect of sodium alginate and AlCl 3 /PAC could flocculate calcite. • The bridging effect of AlCl 3 and sodium alginate optimized the properties of flocs. • The sweep effect of PAC and sodium alginate reduced the number of fine particles. In this study, in-situ flocculation kinetics tests, fourier transform infrared spectroscopy and DFT theoretical calculation were used to analyze flocs properties of calcite flocs under combination of sodium alginate and AlCl 3 /polyaluminum chloride (PAC) and their adsorption mechanism. The results showed that the average size of calcite flocs treated with AlCl 3 -sodium alginate was smaller than that of flocs treated with PAC-sodium alginate. The number of residual fine particles in the slurry treated with AlCl 3 -sodium alginate was more than that in the slurry treated with PAC-sodium alginate. However, the fractal dimension of calcite flocs treated with AlCl 3 -sodium alginate was larger than those treated with PAC-sodium alginate. The sodium alginate and Al3+ could form chemical adsorption on the calcite surface. AlCl 3 has a higher content of Ala than PAC. Ala could form chemical adsorption between sodium alginate and calcite, resulting in a high strength and fractal dimension of calcite flocs. Alb and Alc was not easily able to form metal bridges between calcite and sodium alginate. The sweep effect of PAC and sodium alginate leads to the formation of large-sized flocs. This work can promote the supplication of sodium alginate as a green flocculant. [ABSTRACT FROM AUTHOR]

The densities of three ion species in the Martian upper atmosphere were compared during the MY33 and MY34 Martian regional and global dust storms (RDS 2016 and GDS 2018, respectively) using data from the neutral gas and ion mass spectrometer of the Mars atmosphere and volatile evolution mission. The trends of the ion species and their relative abundances in altitudes compared to some neutral species were examined from 10 September–4 October 2016 and 27 May–18 June 2018, at altitudes of 160–240 km. Both RDS 2016 and GDS 2018 caused variations in the ion species abundance of the upper atmosphere at their onsets in 18–21 September 2016 and 5–8 June 2018 respectively. The densities of O2+, CO2+, and O+ increased during RDS 2016. Meanwhile, O2+ and O+ densities decreased and CO2+ density increased during GDS 2018. Ion species' relative abundances indicate that during RDS 2016, the increase in O2+ density may be caused by the increase of CO2+ or O+ densities rather than the increase of O or CO2 densities. Meanwhile, the decrease in O2+ density during GDS 2018 may be caused by the decrease of O or O+ densities rather than the decrease in CO2+ or CO2 densities. [ABSTRACT FROM AUTHOR]

The densities of three ion species in the Martian upper atmosphere were compared during the MY33 and MY34 Martian regional and global dust storms (RDS 2016 and GDS 2018, respectively) using data from the neutral gas and ion mass spectrometer of the Mars atmosphere and volatile evolution mission. The trends of the ion species and their relative abundances in altitudes compared to some neutral species were examined from 10 September–4 October 2016 and 27 May–18 June 2018, at altitudes of 160–240 km. Both RDS 2016 and GDS 2018 caused variations in the ion species abundance of the upper atmosphere at their onsets in 18–21 September 2016 and 5–8 June 2018 respectively. The densities of O2+, CO2+, and O+ increased during RDS 2016. Meanwhile, O2+ and O+ densities decreased and CO2+ density increased during GDS 2018. Ion species’ relative abundances indicate that during RDS 2016, the increase in O2+ density may be caused by the increase of CO2+ or O+ densities rather than the increase of O or CO2 densities. Meanwhile, the decrease in O2+ density during GDS 2018 may be caused by the decrease of O or O+ densities rather than the decrease in CO2+ or CO2 densities.

Metal and gas ion species and their charge state distributions were measured for pulsed copper cathodic arcs in argon background gas in the presence of an axial magnetic field. It was found that changing the cathode position relative to anode and ion extraction system as well as increasing the gas pressure did not much affect the arc burning voltage and the related power dissipation. However, the burning voltage and power dissipation greatly increased as the magnetic field strength was increased. The fraction of metal ions and the mean ion charge state were reduced as the discharge length was increased. The observations can be explained by the combination of charge exchange collisions and electron impact ionization. They confirm that previously published data on characteristic material-dependent charge state distributions (e.g., Anders and Yushkov, J. Appl. Phys., Vol. 91, pp. 4824-4832, 2002) are not universal but valid for high vacuum conditions and the specifics of the applied magnetic fields.

The effects of multiple ion species have been observed in electromagnetic wave spectra in both the ionosphere and the magnetosphere. Here we report an event from Communication/Navigation Outage Forecast System satellite, showing a new imprint of various ion species in observations of extremely low frequency (ELF) hiss wave spectra near the equatorial ionosphere, which presents minima in the power spectral density at gyrofrequencies and their harmonics of multiple ion species (e.g., O + and He +). Cyclotron harmonic resonant absorption is proposed to account for the observed spectral and polarization properties. Furthermore, the implication of using those wave power spectral minima to identify minor ion species in the ionosphere is discussed. Key Points: An event of wave intensity minima for the equatorial ELF waves at multiple ion cyclotron frequencies and harmonics is reportedThose minima can be explained ion cyclotron harmonic absorption for oblique propagation with respect to the background magnetic fieldWaveform analysis shows polarization and propagation characteristics consistent with the proposed mechanism [ABSTRACT FROM AUTHOR]

Abstract Disinfection byproducts (DBPs) have attracted extensive attention due to their cytotoxicity and genotoxicity. This study investigates the effects of different ions on DBP formation during chlorination and chloramination in artificial and real water samples. Compared with chlorination, chloramination can reduce the formation of DBPs. K+ only reduce the formation of DBPs during chloramination. Ca2+ forms less DBPs than Mg2+ does during chlorination and chloramination due to the stronger binding effect. Al3+ and their hydroxide colloids have a significant effect on DBP formation. Anions have no significant effect on DBP formation. Due to the difference between the real and artificial water samples, the large amount of NH 4 + in the real water will form chloramine during chlorination. Furthermore, the effects of different ion in the chlorination will have the same tendency during chlorination. In the wastewater with high ionic strength, the effects of salts are mostly ignored. Studying the effects of different ions on DBP formation is important in controlling the content of DBPs in the disinfection process. Graphical abstract Image 1 Highlights • The effect of Al3+ on DBPs formation was opposite under Cl 2 and NH 2 Cl disinfection. • The complexation between SRFA and Ca2+ minimize the formation of DBPs. • The anions, such as NO 3 − and SO 4 2−, have little effects on the DBPs formation. • The effects of ions to DBPs formation were insignificant in the real water. [ABSTRACT FROM AUTHOR]

Abstract: This paper examines how hydrogen, helium, and oxygen (H, He, and O) ion fluxes at 1–1,000 keV typically respond to local magnetic dipolarization inside geosynchronous orbit. We extracted 144 dipolarizations that occurred at magnetic inclination >30° from the 2012–2016 tail seasons' observations of the Van Allen Probes spacecraft and then defined typical flux changes of these ion species by performing a superposed epoch analysis. On average, the dipolarization inside geosynchronous orbit is accompanied by a precursory transient decrease in the northward magnetic field component, transient impulsive enhancement in the westward electric field component, and decrease (increase) in the proton density (temperature). The coincident ion species experience an energy‐dependent flux change, consisting of enhancement (depression) at energies above (below) ~50 keV. These properties morphologically resemble those around dipolarization fronts (or fast flows) in the near‐Earth tail. A distinction among the ion species is the average energy of the flux ratio peak, being at 200–400 keV (100–200 keV) for He (H and O) ions. The flux ratio peaks at different energies likely reflect the different charge states of injected ionospheric and/or solar wind origin ion species. The ion spectra become harder for sharp dipolarizations, suggesting the importance of accompanying electric field in transporting and/or energizing the ions efficiently. Interestingly, the average flux ratio peak does not differ significantly among the ion species for ~2 min after onset, which implies that mass‐dependent acceleration process is less important in the initial stage of dipolarization. [ABSTRACT FROM AUTHOR]

In an attempt to investigate the role of ion species in the radiation effects of pyrochlores, polycrystalline Lu 2 Ti 2 O 7 samples, prepared through a standard solid state process, were irradiated with three different ion beams: 400 keV Ne 2+ , 2.7 MeV Ar 11+ and 6.5 MeV Xe 26+ . To characterize the damaged layers in Lu 2 Ti 2 O 7 , the grazing incident X-ray diffraction technique was applied. All the three irradiations induce significant amorphization processes and lattice swelling in Lu 2 Ti 2 O 7 . However, when the ion fluence is converted to a standard dose in dpa, the radiation effects of Lu 2 Ti 2 O 7 show a great dependence on the implanted ion species. The threshold amorphization dose decreases with increasing ion mass and energy. Besides, the amorphization rate, as well as lattice swelling rate, increases with increasing ion mass and energy. That is, the Lu 2 Ti 2 O 7 pyrochlore is more susceptible to amorphization and lattice swelling under heavier ion irradiation. These results are then discussed in the framework of defect configuration and the density of collision cascades based on Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

The saponification and extraction mechanism drives Mg(HCO 3) 2 as a substitution of NaOH to achieve higher separation factor and greener technique. [Display omitted] • Mechanism-driven saponifying agent tuning achieves β increase from 148.98 to 3189.95. • The extraction mechanism of nickel and cobalt has been supplied and visual. • The released alkalinity in saponification-extraction is the key factor in separation. The carbon neutralization urgently requires massive applications of energy storage materials such as lithium-ion batteries. As the critical metal for lithium-ion batteries, the sustainable utilization of nickel and cobalt still takes a long process due to the low separation factor resulting in high costs and environmental concerns, especially in spent lithium-ion batteries (LIBs). In this work, based on the further revealing whole-process mechanism of the typical saponification-extraction process, a new saponifying reagent is proposed to achieve the separation ability of a multistage countercurrent through single-stage extraction solely along with shorter processes and less pollution. The separation factor of cobalt/nickel enhances from 148.98 to 3189.95. and the new saponification-extraction process applies in the recycling of LIBs successfully. The mechanism shows that the alkalinity introduced by saponification is the key factor affecting the separation and purity. Saponification by traditional NaOH releases all putting-in-organic-phase strong alkalinity to aqueous, providing excessive extraction capacity but hindering separation. Therefore, the mild released alkalinity tuning instructs seeking Mg(HCO 3) 2 as an alternative saponifying agent to achieve the balance between released alkalinity and capacity. A cleaner avenue for the high-purity recovery of cobalt and nickel is proposed by mechanism driving, which has the ideological guiding significance to other process improvements. [ABSTRACT FROM AUTHOR]

[Display omitted] • V1 species perform lower interfacial disturbance degree. • V10 species possess greater interface migration capability. • The strengthening effect of microchannel is much stronger in mixed V4 and V10. • V4 species is the predominant vanadium species in the mass transfer process. The complex aqueous metal species distributions limit the purification technology. However, few researchers focus on the mass transfer about metal species. In this paper, the new microfluidic device Raydrop connecting with capillaries are used as microchannels/microreactors for the mass transfer characteristics investigation. The different vanadium solution conditions are applied for the two-phase interface and mass transfer coefficient study. It is proved that the smaller vanadium species, such as V 1 species, perform lower interfacial disturbance degree, and their droplet size is larger and interfacial tension is more stable. Oppositely, V 10 species possess greater interface migration capability on the liquid–liquid interface. The chemical reactions also behave positive effect on the interface transfer. Moreover, the different flow patterns, such as slug flow, droplet flow and annular flow, are decided by different reaction systems and flow rates. The strengthening effect of microchannel is much stronger in mixed V 4 and V 10 aqueous solution than that of single V 4 and V 10 aqueous solution no matter with and without reactions. While in the competitive extraction of vanadium and chromium, the HCrO 4 - and CrO 4 2- species also reacted with H+, so the V 4 species is the predominant vanadium species in the mass transfer process. This paper is promising for the understanding of mass transfer at molecular level. [ABSTRACT FROM AUTHOR]

A method for the controllable synthesis of silver nanoparticles based on a complexing agent method was developed. Citric acid was used as a complexing agent. The effect of pH (1.6 to 5.17) on the size and net height (as obtained from XRD analyses) of silver nanoparticles was investigated. The nanoparticles (10 to 40 nm) were characterized using XRD, TEM, SEM, EDX, UV-Vis spectroscopy and TG/DTG instrument. It was found that pH has a significant influence on both size and crystallinity of the nanoparticles. This is due to the effect of pH on the distribution of citrate ion species which in turn affects the size and crystallinity of the nanoparticles. Increasing the pH value enhances the percentage of [citrate3-] ion species which allows lower size and higher crystallinity of the nanoparticles. Thus, we were able to develop a method for the controllable synthesis of nanoparticles based on the pH.

In this paper, using data obtained by Cluster 4 satellite from 2001 to 2012, we statistically investigate the spatial distributions of H + and O + in the magnetotail plasmasheet and their relation with geomagnetic indices. Our work outlines the existence of two regions with enhanced O + concentration in the tail plasmasheet, one is located in the mid-tail plasmasheet at R > 17 R E , and the other is located near the inner boundary of plasmasheet at R < 10 R E . The existence of the depletion region of O + between 10 R E < R < 17 R E indicates that the O + ions in the mid-tail plasmasheet, which come from polar cap, are not likely to be able to make important contribution to the formation of ring current. Both the distributions of density and temperature of O + ions have a dawn–dusk asymmetry. The number density of O + during geomagnetic active time ( Dst < −20 nT/ AE > 200 nT/ Kp ⩾ 3) is much larger than that during non-storm time ( Dst > −20 nT/ AE < 200 nT/ Kp < 3). This dawn–dusk asymmetry and the number density of O + varying with geomagnetic activity apply for both regions ( R < 10 R E and R > 17 R E ) of O + . Therefore both substorm and enhanced convection provide a large number of O + ions to the plasmasheet, which makes favorable condition for the growth of the ring current. [ABSTRACT FROM AUTHOR]

Five snow pits and five firn cores were sampled during the 2003–2004 Italian Antarctic Campaign at Talos Dome (East Antarctica), where a deep ice core (TALDICE, TALos Dome Ice CorE, 1650 m depth) was drilled in 2005–2008 and analyzed for ionic content. Particular attention is spent in applying decontamination procedures to the firn cores, as core sections were stored for approximately 10 years before analysis. By considering the snow pit samples to be unperturbed, the comparison with firn core samples from the same location shows that ammonium, nitrate and MSA are affected by storage post-depositional losses. All the other measured ions are confirmed to be irreversibly deposited in the snow layer. The removal of the most external layers (few centimeters) from the firn core sections is proved to be an effective decontamination procedure. High-resolution profiles of seasonal markers (nitrate, sulfate and MSA) allow a reliable stratigraphic dating and a seasonal characterization of the samples. The calculated mean accumulation-rate values range from 70 to 85 mm w.e. year − 1 , in the period 2003–1973 with small differences between two sectors: 70–74 mm w.e. year − 1 in the NNE sector (spanning 2003–1996 years) and 81–92 mm w.e. year − 1 in the SSW sector (spanning 2003–1980 years). This evidence is interpreted as a coupled effect of wind-driven redistribution processes in accumulation/ablation areas. Statistical treatment applied to the concentration values of the snow pits and firn cores samples collected in different points reveals a larger temporal variability than spatial one both in terms of concentration of chemical markers and annual accumulation. The low spatial variability of the accumulation rate and chemical composition measured in the five sites demonstrates that the TALDICE ice core paleo-environmental and paleo-climatic stratigraphies can be considered as reliably representative for the Talos Dome area. [ABSTRACT FROM AUTHOR]

We analyze snow-pit samples collected in May 2015 at the South East Dome (SE Dome) on the Greenland ice sheet. The analysis includes high-resolution records of δD and δ 18 O, as well as the major ions, CH 3 SO 3 − , Cl − , NO 3 − , SO 4 2− , Na + , NH 4 + , K + , Ma 2+ , and Ca 2+ . We find that the 3.55-m snow pit recorded temperature and aerosol proxies back to summer or autumn of 2014. This indicates a higher accumulation rate than those at other major drilling sites in Greenland. Due to this high accumulation rate, ion concentrations except Na + are lower than those typical of the central Greenland ice sheet. Concerning seasonal variability, the Na + , Cl − , Ca 2+ , Mg 2+ , and NO 3 − vary similarly to other sites in Greenland, with the Na + and Cl − peaking in winter to early spring, Ca 2+ peaking in spring, Mg 2+ peaking in winter to spring, and NO 3 − towards a peak in summer while showing smaller peaks in winter to spring. The NH 4 + increased in spring, and SO 4 2− increased in autumn to winter at SE Dome. On the other hand, the seasonal trend in the Cl − /Na + ratio differs from those in the inland region. As we did not fully recover one seasonal cycle, some seasonal peaks may have been missed. [ABSTRACT FROM AUTHOR]

Abstract: Doppler shift spectroscopy was established to support the development of the first neutral beam injection system (NBI) on the Experimental Advanced Superconducting Tokamak (EAST). The individual fraction of different beam energy components was determined via measuring the intensity of Doppler-shifted Hα lines emitted by different ions. The ion source was a filament-driven bucket type with four multi-slit rectangular accelerating grids. The ratios of different ions were monitored both in the vertical and horizontal directions to provide detailed information over the beam cross-section. Distorted Gaussian line shape resulting from partially accelerated ions was carefully treated by applying the modified Uhlemann et al. model. Typical spectroscopic experimental results were presented to illustrate the performance of the ion source for optimizing the operation regime of the ion sources. [Copyright &y& Elsevier]

Abstract: Proton ratio is the main parameter to characterize diagnosis neutral beam quality, and determined by ion species fraction of plasma in the ion source. The effect of arc discharge on beam quality has been discussed based on the main electron and gas collision cross-sections in the ion source. The operating parameters were optimized to get a high quality beam with the proton ratio of 40%. [ABSTRACT FROM AUTHOR]

Abstract: We report the chemical composition of PM10-associated water-soluble species in Mexico City during the second semester of 2000. PM10 samples were collected at four ambient air quality monitoring sites in Mexico City. We determined soluble ions (chloride, nitrate, sulfate, ammonium, sodium, potassium), ionizable transition metals (Zn, Fe, Ti, Pb, Mn, V, Ni, Cr, Cu) and soluble protein. The higher PM10 levels were observed in Xalostoc (45–174μgm−3) and the lowest in Pedregal (19–54μgm−3). The highest SO2 average concentrations were observed in Tlalnepantla, NO2 in Merced and O3 and NO x in Pedregal. The concentration range of soluble sulfate was 6.7–7.9 and 19–25.5μgm−3 for ammonium, and 14.8–29.19 for soluble V and 3.2–7.7ngm−3 for Ni, suggesting a higher contribution of combustion sources. PM-associated soluble protein levels varied between 0.038 and 0.169mgm−3, representing a readily inhalable constituent that could contribute to adverse outcomes. The higher levels for most parameters studied were observed during the cold dry season, particularly in December. A richer content of soluble metals was observed when they were expressed by mass/mass units rather than by air volume units. Significant correlations between Ni–V, , , V–SO2, Ni–SO2 suggest the same type of emission source. The variable soluble metal and ion concentrations were strongly influenced by the seasonal meteoclimatic conditions and the differential contribution of emission sources. Our data support the idea that PM10 mass concentration by itself does not provide a clear understanding of a local PM air pollution problem. [Copyright &y& Elsevier]

In this paper, the influence of chemical variables on the mass transfer kinetics of ionic species under dynamic conditions in flow-through sandwich-type dialysers is thoroughly investigated. Although the driving force of the mass transport is the existence of a concentration gradient between the two phases separated by a semi-permeable membrane, it has been demonstrated that the chemical composition of both donor and acceptor solutions in terms of concentration and kind of ionic compounds has a significant influence on the mass transfer efficiency. The Donnan effect on passive dialysis and the fast migration of ions concomitantly present with the target species improved the transfer of the analyte ion in the membrane separation process. Thus, for the determination of low molecular weight anions, the addition of cationic species with high transport index, such as oxonium ion, to the donor stream, or multicharged ions (e.g. Al3+) to the recipient stream, enhanced the dialysis yields more than 62% with respect to the use of water as acceptor and sample medium.As a consequence of the dependence of the dialysis rate on the composition of the sample matrix, different diffusate concentrations were encountered for the same input concentration of analyte when prepared in different electrolytic media. In order to balance the chemical potential on the donor side, the ionic strength for both standards and sample solutions should be carefully adjusted via incorporation of a modifier stream in the flow manifold (e.g. 1.0 mol l-1 KNO3 or 0.5 mol l-1 H2SO4) as demonstrated in the bulk of the text. Appropriate buffering of the recipient solution was equally effective. Furthermore, these strategies were found suitable to overcome the lack of linearity observed by several researchers in in-line dialytic processes at low concentrations of ionic species caused by polar interactions with the membrane surface.Chloride was selected as a model of target species for assessing the effect of chemical variables on the mass transfer rate in flow-through parallel-plate dialyser units. The spectrophotometric detection scheme for chloride, implemented in a secondary flow configuration, is based on the displacement reaction of thiocyanate from the corresponding mercury salt in the presence of iron(III). [Copyright &y& Elsevier]

We investigated the effect of cations on the protein extraction into AOT/isooctane reversed micellar solutions using alkaline and alkaline-earth metal ions. Cations greatly influenced the extraction ratio of protein in an order of K+

In recent years, microplastics (MPs) and nanoplastics (NPs) have attracted worldwide attention because of the potential risks they pose to aquatic environments, but there are few studies on the difference of aggregation mechanism between MPs and NPs. In this study, 100 nm and 1 μm polystyrene plastics were selected as models to explore the aggregation mechanism of MPs/NPs under different aquatic environments. The influence of ion species and concentrations on the aggregation behaviors and kinetics were systematically investigated to predict the effects of water quality on the occurrence form of MPs and NPs based on DLVO theory and revised modified Smoluchowski theory. Results showed concentration, valence and hydrated ability of cations jointly affected the aggregation behavior of NPs. The critical coagulation concentration ratio of cations were consistent with Schulze-Hardy rules. But the different aggregation rate coefficients of same valent cations were ascribed to the structural layer force. Anion species played a role in the reaction-controlled regime by producing hydrogen ions to neutralize negative charges on NPs surfaces. Due to the strong Brownian motion and structural layer force, NPs would be stable in freshwater but preferentially aggregated when transport through brackish water, estuaries, eutrophication and high hardness areas and sea water, forming the accumulation hot spots of NPs in the sediment. While for MPs, physical process controlled the aggregation mechanism of them, leading to high stability in natural water and eventually transporting into marine environments. This study provided a theoretical foundation for assessing the transport, distribution, fate and ecological risks of MPs and NPs in realistic aquatic environments. Image 1 • Physical process controls aggregation mechanism of MPs. • Brownian motion and structural layer force play a dominant role in aggregation behavior of NPs. • The concentration, valence and hydrated ability of cations jointly affect aggregation rate and aggregate structure of NPs. • Anion species play a role in the reaction-controlled regime. • NPs preferentially aggregate in eutrophication, high hardness areas and sea water. Main finding: Physical process controls aggregation behavior of MPs, while Brownian motion and structural layer force dominate that of NPs. [ABSTRACT FROM AUTHOR]

The application of an energy and mass selected ion beam assisted deposition setup to investigate the influence of hyperthermal atomic and molecular nitrogen ion species during the initial stages of epitaxial GaN thin film growth is reported. By using a compact quadrupole mass filter system a hyperthermal ion beam is mass filtered. The GaN thin film depositions with varying ion-to-atom arrival ratio and kinetic energies of 40 eV and 80 eV are performed to highlight the distinct impact of the ion species on the early stages of the growth. It is evaluated that precise selection of ion beam parameters enables the preferred growth of either the metastable zinc blende GaN phase or the stable wurtzite GaN phase on 6H-SiC(0001) substrates. Further, using molecular nitrogen ion species thin films of high crystalline quality could be deposited even at ion kinetic energies of 80 eV, while films with atomic nitrogen ion assistance feature reduced crystalline quality. Unlabelled Image • GaN films are deposited on 6H-SiC(0001) using energy and mass filtered nitrogen ions. • The utilization of N+ promotes three-dimensional growth. • At higher ion kinetic energies, N 2 + preserves the crystalline quality. • Preferred crystal phase selection between zinc blende and wurtzite GaN is observed. [ABSTRACT FROM AUTHOR]

Dry deposition flux and particle concentration of mass, Ca2+, Mg2+, Cl- and SO42- were measured by dry deposition plates and NRI (Noll Rotary Impactor), MOUDI (Micro-Orifice Uniform Deposit Impactor), respectively in theambient air of Chung Hsing University and Tung-Hai University in central Taiwan from November 1995 to January 1996. A AA-68016 flame atomic absorption spectrophotometer was used to measure the metals Cl- and Mg2+; and a 1. C. (DIONEX DX- 100 Ion Chromatography) was used to measure the ions Cl- and SO42- species. The CHU sampling site was divided into two parts to discuss the influence of coarse particle on the concentrationand deposition velocities. The average mass concentration (without NRI sampler) for the fine and coarse particles were 21.6, 23.8 and 19.8, 21 6 mug/m3 in CHU and THU sampling site, respectively.By the same token, the average mass concentration (with NRI sampler)for the fine and coarse particles were 26.4 and 30.9 mug/m3 in CHU sampling site, separately. The results indicated that the average deposition velocities were 1.34, 1.11, 1.19, 0.11 and 0 27 (cm/sec) for mass, Ca2+, Mg2+, Cl- and SO42-, respectively in CHU area with NRI sampler. And the results also displayed the average deposition velocities were 1.58, 1 23, 1.64, 0.52 and 0 58 (cm/sec) for mass, Ca2+, Mg2+, Cl- and SO42-, separately in CHU sampling site without NRI sampler. The deposition velocities were 3.93, 2.69 and 2.23 (cm/sec) for mass, Ca2+ and Mg2+, respectively in THU sampling site without NRI sampler. Thus, this study showed that the coarse particle did have significant influence on the urban and suburban area of central Taiwan. In the ambient air of CHU the correlation coefficient of average wind spee [ABSTRACT FROM AUTHOR]