Ion climate and radon concentration

International Nuclear Information System (INIS)

Busbarna, L.

1981-01-01

Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

Combined HPLC-CUPRAC (cupric ion reducing antioxidant capacity) assay of parsley, celery leaves, and nettle.

Science.gov (United States)

Yildiz, Leyla; Başkan, Kevser Sözgen; Tütem, Esma; Apak, Reşat

2008-10-19

This study aims to identify the essential antioxidant compounds present in parsley (Petroselinum sativum) and celery (Apium graveolens) leaves belonging to the Umbelliferae (Apiaceae) family, and in stinging nettle (Urtica dioica) belonging to Urticaceae family, to measure the total antioxidant capacity (TAC) of these compounds with CUPRAC (cupric ion reducing antioxidant capacity) and ABTS spectrophotometric methods, and to correlate the TAC with high performance liquid chromatography (HPLC) findings. The CUPRAC spectrophotometric method of TAC assay using copper(II)-neocuproine (2,9-dimethyl-1,10-phenanthroline) as the chromogenic oxidant was developed in our laboratories. The individual antioxidant constituents of plant extracts were identified and quantified by HPLC on a C18 column using a modified mobile phase of gradient elution comprised of MeOH-0.2% o-phosphoric acid and UV detection for polyphenols at 280 nm. The TAC values of HPLC-quantified antioxidant constituents were found, and compared for the first time with those found by CUPRAC. The TAC of HPLC-quantified compounds accounted for a relatively high percentage of the observed CUPRAC capacities of plant extracts, namely 81% of nettle, 60-77% of parsley (in different hydrolyzates of extract and solid sample), and 41-57% of celery leaves (in different hydrolyzates). The CUPRAC total capacities of the 70% MeOH extracts of studied plants (in the units of mmol trolox g(-1)plant) were in the order: celery leaves>nettle>parsley. The TAC calculated with the aid of HPLC-spectrophotometry did not compensate for 100% of the CUPRAC total capacities, because all flavonoid glycosides subjected to hydrolysis were either not detectable with HPLC, or not converted to the corresponding aglycons (i.e., easily detectable and quantifiable with HPLC) during the hydrolysis step.

Microstructural and electrical properties of PVA/PVP polymer blend films doped with cupric sulphate

Energy Technology Data Exchange (ETDEWEB)

Hemalatha, K.; Gowtham, G. K.; Somashekarappa, H., E-mail: drhssappa@gmail.com [Department of Physics, Yuvaraja’s College, University of Mysore, Mysore 570 005, Karnataka (India); Mahadevaiah,; Urs, G. Thejas; Somashekar, R. [Department of Studies in Material Sciences, University of Mysore, Mysore 570 006, Karnataka (India)

2016-05-23

A series of polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP) polymer blends added with different concentrations of cupric sulphate (CuSO{sub 4}) were prepared by solution casting method and were subjected to X-ray diffraction (XRD) and Ac conductance measurements. An attempt has been made to study the changes in crystal imperfection parameters in PVA/PVP blend films with the increase in concentration of CuSO{sub 4}. Results show that decrease in micro crystalline parameter values is accompanied with increase in the amorphous content in the film which is the reason for film to have more flexibility, biodegradability and good ionic conductivity. AC conductance measurements in these films show that the conductivity increases as the concentration of CuSO{sub 4} increases. These films were suitable for electro chemical applications.

Synthesis and characterization of cupric oxide (CuO) nanoparticles ...

African Journals Online (AJOL)

In the present work, cupric oxide (CuO) nanoparticles (NPs) were prepared by adopting aqueous precipitation method using copper sulphate 5-hydrate as a precursor and NaOH as a stabilizing agent. This gives a large scale production of CuO-NPs which are utilized for the removal of methylene blue (MB) dye. The CuO ...

Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters.

Science.gov (United States)

Nogueira, C A; Paiva, A P; Oliveira, P C; Costa, M C; da Costa, A M Rosa

2014-08-15

The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu(2+) concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4h, [HCl] = 6M, [Cu(2+)] = 0.3M). Copyright © 2014 Elsevier B.V. All rights reserved.

Hip implants - Paper VI - Ion concentrations

Energy Technology Data Exchange (ETDEWEB)

Sargeant, A. [Department of Biological Sciences, Ohio Northern University, Ada, OH 45810 (United States); Goswami, T. [Department of Mechanical Engineering, Ohio Northern University, Ada, OH 45810 (United States)]. E-mail: t-goswami@onu.edu

2007-07-01

Total hip-joint arthroplasty is performed in increasing numbers where it translates to about 0.16-0.2% of population per year in industrial countries. In most cases, an implant is a metallic component articulating with a metal, ceramic or poly-ethylene liner as seen in the case of hip, knee and spine. The metal implants release ions in vivo. Therefore, there is a need to study metallic implants and ions released as a result. Toxic concentrations of ions can lead to many adverse physiological effects, including cytotoxicity, genotoxicity, carcinogenicity, and metal sensitivity. There is a need to map ion concentrations establishing boundaries between normal and toxic levels; which however, does not exist. Reference levels of ion concentrations in body fluids and tissues determined by many studies are compiled, reviewed, and presented in this paper. The concentrations of ions released from different alloys, including cobalt, chromium, nickel, molybdenum titanium, aluminum, and vanadium, are presented in this paper. This paper reviews the literature pertaining to clinical data on metal ion concentrations in patients with metal joint prostheses, and laboratory data on the physiological effects of the metals.

Spontaneous interfacial reaction between metallic copper and PBS to form cupric phosphate nanoflower and its enzyme hybrid with enhanced activity.

Science.gov (United States)

He, Guangli; Hu, Weihua; Li, Chang Ming

2015-11-01

We herein report the spontaneous interfacial reaction between copper foil with 0.01 M phosphate buffered saline (PBS) to form free-standing cupric phosphate (Cu3(PO4)2) nanoflowers at ambient temperature. The underlying chemistry was thoroughly investigated and it is found that the formation of nanoflower is synergistically caused by dissolved oxygen, chlorine ions and phosphate ions. Enzyme-Cu3(PO4)2 hybrid nanoflower was further prepared successfully by using an enzyme-dissolving PBS solution and the enzymes in the hybrid exhibit enhanced biological activity. This work provides a facile route for large-scale synthesis of hierarchical inorganic and functional protein-inorganic hybrid architectures via a simple one-step solution-immersion reaction without using either template or surfactant, thus offering great potential for biosensing application among others. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of preparation conditions and the ionizing radiation on the kinetics of cupric oxide reduction by hydrogen

International Nuclear Information System (INIS)

Pospisil, M.; Taras, P.

1977-01-01

Cupric oxide reduction in the temperature interval 170 to 350 degC was studied by thermogravimetry. The reduction kinetics can be quantitatively described by the modified Prout-Tompkinson equation, with the apparent activation energy varying within the limits (4.94 to 5.82)x10 4 J/mol. Irregularities observed during the reduction of the oxide of the oxalate origin are due to the high content of the metallic phase. The p-semiconducting nature of these oxides was proved for all samples. The effect of the pre-irradiation of samples with γ-rays (with an absorbed dose of (1.4 to 4.75)x10 6 J/kg) on the reduction kinetics depends on the origin of the cupric oxide. In contrast to NiO no correlation between the content of super-stoichiometric oxygen and the reduction kinetics was found. After irradiation with γ-rays or with fast neutrons at a dose of 79.8 J/kg the reduction rate increases and the activation energy decreases regardless of the oxide origin. At the same time the concentration of the ionic form of super-stoichiometric oxygen increases. (author)

Oxidative leaching process with cupric ion in hydrochloric acid media for recovery of Pd and Rh from spent catalytic converters

Energy Technology Data Exchange (ETDEWEB)

Nogueira, C.A., E-mail: carlos.nogueira@lneg.pt [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Paiva, A.P., E-mail: appaiva@fc.ul.pt [Centro de Química e Bioquímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisboa (Portugal); Oliveira, P.C. [Laboratório Nacional de Energia e Geologia, I.P., Campus do Lumiar, 1649-038 Lisboa (Portugal); Costa, M.C., E-mail: mcorada@ualg.pt [Centro de Ciências do Mar, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal); Costa, A.M. Rosa da, E-mail: amcosta@ualg.pt [Centro de Investigação em Química do Algarve, Departamento de Química e Farmácia, Faculdade de Ciências e de Tecnologia, Campus de Gambelas, 8005-139 Faro (Portugal)

2014-08-15

Highlights: • A new leaching process based on Cu{sup 2+}/HCl media for recovering Pd and Rh from spent autocatalytic converters is presented. • Palladium and rhodium were efficiently leached, with attained maximum yields of 95% and 86%, respectively. • Temperature, time, and HCl and Cu{sup 2+} concentrations were found to be significant factors in the leaching of Pd and Rh. - Abstract: The recycling of platinum-group metals from wastes such as autocatalytic converters is getting growing attention due to the scarcity of these precious metals and the market pressure originated by increase of demand in current and emerging applications. Hydrometallurgical treatment of such wastes is an alternative way to the most usual pyrometallurgical processes based on smelter operations. This paper focuses on the development of a leaching process using cupric chloride as oxidising agent, in HCl media, for recovery of palladium and rhodium from a spent catalyst. The chloride media allows the adequate conditions for oxidising and solubilising the metals, as demonstrated by equilibrium calculations based on thermodynamic data. The experimental study of the leaching process revealed that Pd solubilisation is clearly easier than that of Rh. The factors temperature, time, and HCl and Cu{sup 2+} concentrations were significant regarding Pd and Rh leaching, the latter requiring higher factor values to achieve the same results. Leaching yields of 95% Pd and 86% Rh were achieved under optimised conditions (T = 80 °C, t = 4 h, [HCl] = 6 M, [Cu{sup 2+}] = 0.3 M)

Air ion concentrations in various urban outdoor environments

Science.gov (United States)

Ling, Xuan; Jayaratne, Rohan; Morawska, Lidia

2010-06-01

Atmospheric ions are produced by many natural and anthropogenic sources and their concentrations vary widely between different environments. There is very little information on their concentrations in different types of urban environments, how they compare across these environments and their dominant sources. In this study, we measured airborne concentrations of small ions, particles and net particle charge at 32 different outdoor sites in and around a major city in Australia and identified the main ion sources. Sites were classified into seven groups as follows: park, woodland, city centre, residential, freeway, power lines and power substation. Generally, parks were situated away from ion sources and represented the urban background value of about 270 ions cm -3. Median concentrations at all other groups were significantly higher than in the parks. We show that motor vehicles and power transmission systems are two major ion sources in urban areas. Power lines and substations constituted strong unipolar sources, while motor vehicle exhaust constituted strong bipolar sources. The small ion concentration in urban residential areas was about 960 cm -3. At sites where ion sources were co-located with particle sources, ion concentrations were inhibited due to the ion-particle attachment process. These results improved our understanding on air ion distribution and its interaction with particles in the urban outdoor environment.

The effect of Cu (II) on the electro-olfactogram (EOG) of the Atlantic salmon (Salmo salar L) in artificial freshwater of varying inorganic carbon concentrations

DEFF Research Database (Denmark)

Winberg, S; Bjerselius, R; Baatrup, E

1993-01-01

The effect of inorganic copper species was studied by recording the receptor potential, electro-olfactogram (EOG), from the olfactory epithelium of Atlantic salmon (Salmo salar L). In a series of experiments, the olfactory organ was irrigated with aqueous copper solutions with concentrations...... of the free cupric ion (Cu2+) ranging from 0.2 to 9.7 microM. The diverse copper species were created by varying the amount of bicarbonate (NaHCO3) in artificial freshwater solutions of equal total copper concentrations. In general, these copper solutions induced a slow depolarization of the baseline followed...

Morphology selection for cupric oxide thin films by electrodeposition.

Science.gov (United States)

Dhanasekaran, V; Mahalingam, T; Chandramohan, R

2011-10-01

Polycrystalline cupric oxide thin films were deposited using alkaline solution bath employing cathodic electrodeposition method. The thin films were electrodeposited at various solution pH. The surface morphology and elemental analyzes of the films were studied using scanning electron microscopy (SEM) and energy dispersive X-ray analysis, respectively. SEM studies revealed that the surface morphology could be tailored suitably by adjusting the pH value during deposition. Mesh average on multiple lattice mode atomic force microscopy image was obtained and reported. Copyright © 2011 Wiley-Liss, Inc.

Variability of air ion concentrations in urban Paris

Science.gov (United States)

Dos Santos, V. N.; Herrmann, E.; Manninen, H. E.; Hussein, T.; Hakala, J.; Nieminen, T.; Aalto, P. P.; Merkel, M.; Wiedensohler, A.; Kulmala, M.; Petäjä, T.; Hämeri, K.

2015-12-01

Air ion concentrations influence new particle formation and consequently the global aerosol as potential cloud condensation nuclei. We aimed to evaluate air ion concentrations and characteristics of new particle formation events (NPF) in the megacity of Paris, France, within the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric Pollution and climate effects, and Integrated tools for assessment and mitigation) project. We measured air ion number size distributions (0.8-42 nm) with an air ion spectrometer and fine particle number concentrations (> 6 nm) with a twin differential mobility particle sizer in an urban site of Paris between 26 June 2009 and 4 October 2010. Air ions were size classified as small (0.8-2 nm), intermediate (2-7 nm), and large (7-20 nm). The median concentrations of small and large ions were 670 and 680 cm-3, respectively, (sum of positive and negative polarities), whereas the median concentration of intermediate ions was only 20 cm-3, as these ions were mostly present during new particle formation bursts, i.e. when gas-to-particle conversion produced fresh aerosol particles from gas phase precursors. During peaks in traffic-related particle number, the concentrations of small and intermediate ions decreased, whereas the concentrations of large ions increased. Seasonal variations affected the ion population differently, with respect to their size and polarity. NPF was observed in 13 % of the days, being most frequent in spring and late summer (April, May, July, and August). The results also suggest that NPF was favoured on the weekends in comparison to workdays, likely due to the lower levels of condensation sinks in the mornings of weekends (CS weekdays 09:00: 18 × 10-3 s-1; CS weekend 09:00: 8 × 10-3 s-1). The median growth rates (GR) of ions during the NPF events varied between 3 and 7 nm h-1, increasing with the ion size and being higher on workdays than on weekends for intermediate and large ions. The median GR of

Ion Concentration- and Voltage-Dependent Push and Pull Mechanisms of Potassium Channel Ion Conduction.

Directory of Open Access Journals (Sweden)

Kota Kasahara

Full Text Available The mechanism of ion conduction by potassium channels is one of the central issues in physiology. In particular, it is still unclear how the ion concentration and the membrane voltage drive ion conduction. We have investigated the dynamics of the ion conduction processes in the Kv1.2 pore domain, by molecular dynamics (MD simulations with several different voltages and ion concentrations. By focusing on the detailed ion movements through the pore including selectivity filter (SF and cavity, we found two major conduction mechanisms, called the III-IV-III and III-II-III mechanisms, and the balance between the ion concentration and the voltage determines the mechanism preference. In the III-IV-III mechanism, the outermost ion in the pore is pushed out by a new ion coming from the intracellular fluid, and four-ion states were transiently observed. In the III-II-III mechanism, the outermost ion is pulled out first, without pushing by incoming ions. Increases in the ion concentration and voltage accelerated ion conductions, but their mechanisms were different. The increase in the ion concentrations facilitated the III-IV-III conductions, while the higher voltages increased the III-II-III conductions, indicating that the pore domain of potassium channels permeates ions by using two different driving forces: a push by intracellular ions and a pull by voltage.

Decomposition analysis of cupric chloride hydrolysis in the Cu-Cl cycle of hydrogen production

International Nuclear Information System (INIS)

Daggupati, V.N.; Naterer, G.F.; Gabriel, K.S.; Gravelsins, R.; Wang, Z.

2009-01-01

This paper examines cupric chloride solid conversion during hydrolysis in a thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production. The hydrolysis reaction is a challenging step, in terms of the excess steam requirement and the decomposition of cupric chloride (CuCl 2 ) into cuprous chloride (CuCl) and chlorine (Cl 2 ). The hydrolysis and decomposition reactions are analyzed with respect to the chemical equilibrium constant. The effects of operating parameters are examined, including the temperature, pressure, excess steam and equilibrium conversion. A maximization of yield and selectivity are very important. Rate constants for the simultaneous reaction steps are determined using a uniform reaction model. A shrinking core model is used to determine the rate coefficients and predict the solid conversion time, with diffusional and reaction control. These new results are useful for scale-up of the engineering equipment in the thermochemical Cu-Cl cycle for hydrogen production. (author)

Preparation of octahedral CuO micro/nanocrystals and electrochemical performance as anode for lithium-ion battery

International Nuclear Information System (INIS)

Feng, Lili; Xuan, Zhewen; Bai, Yang; Zhao, Hongbo; Li, Li; Chen, Yashun; Yang, Xianqin; Su, Changwei; Guo, Junming; Chen, Xiaokai

2014-01-01

Highlights: • Octahedral cupric oxides with hollow structure were prepared. • No hard template was used in the preparation of hollow cupric oxides. • The cupric oxides show good reversible capacity. - Abstract: Herein we report that three octahedral CuO samples with hollow or solid structure are successfully prepared by firstly preparation of Cu 2 O products using a chemical reduction method, then by calcination in a muffle furnace at 300 °C for 3 h in air atmosphere. The obtained CuO samples serve as a good model system for the study as anodes for lithium ion batteries. All the three CuO samples have high discharge specific capacity and good cycling stability from the 2nd cycling to the 50th cycling. Octahedral CuO hollow crystals with 400 nm in size have the highest reversible capacity and the smallest resistance. So their electrochemical performances are partly related to their morphologies. The results suggest that the as-prepared CuO samples, especially the 400 nm hollow octahedral CuO crystals could be a promising material for the anode of lithium-ion battery

Potentiometric determination of sulfate with EDTA and the cupric-selective electrode

International Nuclear Information System (INIS)

Baumann, E.W.

1976-11-01

Sulfate was indirectly determined by precipitating sulfate as BaSO 4 and then dissolving BaSO 4 in excess ammoniacal EDTA. The excess EDTA was titrated potentiometrically with La 3+ . A cupric-selective electrode was used to detect the end point. About 10 -3 M SO 4 2- was determined in 3M HCl solutions of metal oxides with a relative standard deviation of 3.5 percent and a bias of +4 percent

Capillary Ion Concentration Polarization for Power-Free Salt Purification

Science.gov (United States)

Park, Sungmin; Jung, Yeonsu; Cho, Inhee; Kim, Ho-Young; Kim, Sung Jae

2014-11-01

In this presentation, we experimentally and theoretically demonstrated the capillary based ion concentration polarization for power-free salt purification system. Traditional ion concentration polarization phenomenon has been studied for a decade for both fundamental nanoscale fluid dynamics and novel engineering applications such as desalination, preconcentration and energy harvesting devices. While the conventional system utilizes an external power source, the system based on capillary ion concentration polarization is capable of perm-selective ion transportation only by capillarity so that the same ion depletion zone can be formed without any external power sources. An ion concentration profile near the nanostructure was tracked using fluorescent probes and analyzed by solving the modified Nernst-Planck equation. As a result, the concentration in the vicinity of the nanostructure was at least 10 times lower than that of bulk electrolyte and thus, the liquid absorbed into the nanostructure had the low concentration. This mechanism can be used for the power free salt purification system which would be significantly useful in underdeveloped and remote area. This work was supported by Samsung Research Funding Center of Samsung Electronics under Project Number SRFC-MA1301-02.

Effects of Thermal Annealing Conditions on Cupric Oxide Thin Film

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyo Seon; Oh, Hee-bong; Ryu, Hyukhyun [Inje University, Gimhae (Korea, Republic of); Lee, Won-Jae [Dong-Eui University, Busan (Korea, Republic of)

2015-07-15

In this study, cupric oxide (CuO) thin films were grown on fluorine doped tin oxide(FTO) substrate by using spin coating method. We investigated the effects of thermal annealing temperature and thermal annealing duration on the morphological, structural, optical and photoelectrochemical properties of the CuO film. From the results, we could find that the morphologies, grain sizes, crystallinity and photoelectrochemical properties were dependent on the annealing conditions. As a result, the maximum photocurrent density of -1.47 mA/cm{sup 2} (vs. SCE) was obtained from the sample with the thermal annealing conditions of 500 ℃ and 40 min.

Influence of temperature and ion concentration on sedimentation ...

African Journals Online (AJOL)

TSP sedimentation order also ranged between 0.58 and 1.31 at constant phosphate ions concentration and between 1.55 and 1.81 at constant strontium ions concentration. ... Data may be employed as additional design information for modeling physiochemical phosphate removal in water treatment technology. Keywords: ...

Ion-ion Recombination and Chemiion Concentrations In Aircraft Exhaust

Science.gov (United States)

Turco, R. P.; Yu, F.

Jet aircraft emit large quantities of ultrafine volatile aerosols, as well as soot parti- cles, into the environment. To determine the long-term effects of these emissions, a better understanding of the mechanisms that control particle formation and evolution is needed, including the number and size dispersion. A recent explanation for aerosol nucleation in a jet wake involves the condensation of sulfuric acid vapor, and cer- tain organic compounds, onto charged molecular clusters (chemiions) generated in the engine combustors (Yu and Turco, 1997). Massive charged aggregates, along with sulfuric acid and organic precursor vapors, have been detected in jet plumes under cruise conditions. In developing the chemiion nucleation theory, Yu and Turco noted that ion-ion recombination in the engine train and jet core should limit the chemiion emission index to 1017/kg-fuel. This value is consistent with ion-ion recombination coefficients of 1×10-7 cm3/s over time scales of 10-2 s. However, the evolution of the ions through the engine has not been adequately studied. The conditions at the combustor exit are extreme-temperatures approach 1500 K, and pressures can reach 30 atmospheres. In this presentation, we show that as the combustion gases expand and cool, two- and three-body ion-ion recombination processes control the chemiion concentration. The concepts of mutual neutralization and Thomson recombination are first summarized, and appropriate temperature and pressure dependent recombination rate coefficients are derived for the aircraft problem. A model for ion losses in jet exhaust is then formulated using an "invariance" principle discussed by Turco and Yu (1997) in the context of a coagulating aerosol in an expanding plume. This recombina- tion model is applied to estimate chemiion emission indices for a range of operational engine conditions. The predicted ion emission rates are found to be consistent with observations. We discuss the sources of variance in chemiion

Can Cu(II) ions be doped into the crystal structure of potassium hydrogen tartrate?

OpenAIRE

Srinivasan, Bikshandarkoil R.; Remesh, H.

2015-01-01

The differing binding preferences of the hydrogen tartrate ligand (HC4H4O6)- namely {\\mu}7-octadentate mode for potassium ion and bidentate mode for cupric ion rules out the doping (incorporation) of any Cu(II) ion into the crystal structure of potassium hydrogen tartrate. Hence, the claim of growth of copper doped potassium hydrogen tartrate viz. K0.96Cu0.04C4H5O6 by Mathivanan and Haris, Indian J Pure App Phys 51 (2013) 851-859 is untenable.

[The relationship between PMI and concentration of potassium ion and sodium ion in swine aqueous humor after death].

Science.gov (United States)

Han, Ju; Yu, Guang-biao; Dong, Ye-qiang; Fang, Chao; Jing, Hua-lan; Luo, Si-min

2010-04-01

To explored the relationship between the concentration of potassium ion as well as sodium ion in the aqueous humor and post-mortem interval (PMI). The concentrations of potassium ion and sodium ion in the aqueous humor of swine within 48 h after death at 4 degrees C and 28 degrees C were detected using Z-500 atomic absorption spectrophotometer. The concentrations of potassium ion and sodium ion in aqueous humor of isolated swine eyeballs within 48 h after death when the environmental temperature was 4 degrees C were significantly related to PMI. The relationship between PMI and the concentration of potassium ion was PMI = -0.178[K+]2 + 49.978 (R2 = 0.995). The relationship between PMI and the rate of sodium ion and potassium ion was PMI = 120.987/[Na+/K+]-28.834 (R2 = 0.905). The concentration of potassium in aqueous humor of isolated swine eyeballs may be one of the reference indicators to estimate PMI of the corpses at lower temperatures.

COMPLEX OF NUMERICAL MODELS FOR COMPUTATION OF AIR ION CONCENTRATION IN PREMISES

Directory of Open Access Journals (Sweden)

M. M. Biliaiev

2016-04-01

Full Text Available Purpose. The article highlights the question about creation the complex numerical models in order to calculate the ions concentration fields in premises of various purpose and in work areas. Developed complex should take into account the main physical factors influencing the formation of the concentration field of ions, that is, aerodynamics of air jets in the room, presence of furniture, equipment, placement of ventilation holes, ventilation mode, location of ionization sources, transfer of ions under the electric field effect, other factors, determining the intensity and shape of the field of concentration of ions. In addition, complex of numerical models has to ensure conducting of the express calculation of the ions concentration in the premises, allowing quick sorting of possible variants and enabling «enlarged» evaluation of air ions concentration in the premises. Methodology. The complex numerical models to calculate air ion regime in the premises is developed. CFD numerical model is based on the use of aerodynamics, electrostatics and mass transfer equations, and takes into account the effect of air flows caused by the ventilation operation, diffusion, electric field effects, as well as the interaction of different polarities ions with each other and with the dust particles. The proposed balance model for computation of air ion regime indoors allows operative calculating the ions concentration field considering pulsed operation of the ionizer. Findings. The calculated data are received, on the basis of which one can estimate the ions concentration anywhere in the premises with artificial air ionization. An example of calculating the negative ions concentration on the basis of the CFD numerical model in the premises with reengineering transformations is given. On the basis of the developed balance model the air ions concentration in the room volume was calculated. Originality. Results of the air ion regime computation in premise, which

Measurements of ion concentration in gasoline and diesel engine exhaust

Science.gov (United States)

Yu, Fangqun; Lanni, Thomas; Frank, Brian P.

The nanoparticles formed in motor vehicle exhaust have received increasing attention due to their potential adverse health effects. It has been recently proposed that combustion-generated ions may play a critical role in the formation of these volatile nanoparticles. In this paper, we design an experiment to measure the total ion concentration in motor vehicle engine exhaust, and report some preliminary measurements in the exhaust of a gasoline engine (K-car) and a diesel engine (diesel generator). Under the experimental set-up reported in this study and for the specific engines used, the total ion concentration is ca. 3.3×10 6 cm -3 with almost all of the ions smaller than 3 nm in the gasoline engine exhaust, and is above 2.7×10 8 cm -3 with most of the ions larger than 3 nm in the diesel engine exhaust. This difference in the measured ion properties is interpreted as a result of the different residence times of exhaust inside the tailpipe/connecting pipe and the different concentrations of soot particles in the exhaust. The measured ion concentrations appear to be within the ranges predicted by a theoretical model describing the evolution of ions inside a pipe.

Ion-exchange concentration of inorganic anions from aqueous solution

Directory of Open Access Journals (Sweden)

L. P. Bondareva

2016-01-01

Full Text Available Monitoring of natural waters in the present time - consuming process, the accuracy of which is influenced by many factors: the composition of water, the presence of impurities and "interfering" components. The water sample preparation process includes the step of concentration and separation of ions determined. The most versatile, efficient, and frequently used method is the concentration of inorganic anions from aqueous solutions by ion exchanger, which can optimize the composition of water to the optimal for identification and quantitative determination of anions. The characteristics of sorption chloride, nitrate and sulfate ions of basic anion exchange resin AВ-17 and Purolite A430 were compared in the article. The constants of protolysis of ion exchangers both AB 17 and Purolite A430 are the same and equal 0.037 ± 0,002. The value of total capacity (POE Purolite A430 was 4.3 mmol/g, AB 17 – 3.4 mmol/g. The studied ion exchangers have the same type of ionic groups – quaternary ammonium, but their number and denotes differ. The number of quaternary ammonium groups is higher in Purolite A430, respectively the number of absorbed anions of these ion exchanger is higher. The values of dynamic exchange capacity (DOE of ion exchanger Purolite A430 is higher than these values of AB-17 and equal to 1.48 ± 0.03 mmol / dm3 for chloride ion, 1.50 ± 0.03 mmol / dm3 for nitrate ion, 1.62 ± 0.03 mmol / dm3 for sulfate ion. The values of the POE and DOE of anion-exchange resins Purolite A430 and AV-17 and the characteristics of the individual sorption of chloride, nitrate, sulfate ions showed an advantage of the Purolite for the concentrationing of anions. It is found that times of anions sorption from triple-anion solutions by Purolite A430 are significantly different for different anions, and these times are close for anion-exchanger AV-17. It proves the possibility of quantitative separation and concentration by anion-exchanger Purolite A430.

Modeling for copper transport within the boundary layer in an electrodialysis cell

International Nuclear Information System (INIS)

Ibanez, J. P.; Aracena, A.; Ipinza, J.; Cifuentes, L.

2004-01-01

A semi empirical model was developed to characterize the transport of cupric ions within the Nernst layer generated between electrolyte bulk and the membrane surface in an electrodialysis cell. The model was derived from fundamental equations and was reduced to a linear expression incorporating the cupric ion transport number in the Nernst layer (t+BL) and in the membrane (t+m). The model critical condition is t+BL <0.5 t+m. The model correctly fits the experimental data when t+BL is o.02. the model was validated with experimental results previously published by the authors and it accounts for a linear concentration gradient within the Nernst layer. (Author) 28 refs

Effect of chloride ions on the corrosion behavior of low-alloy steel containing copper and antimony in sulfuric acid solution

Science.gov (United States)

Park, Sun-Ah; Kim, Seon-Hong; Yoo, Yun-Ha; Kim, Jung-Gu

2015-05-01

The influence of the addition of HCl on the corrosion behavior of low-alloy steel containing copper and antimony was investigated using electrochemical (potentiodynamic and potentiostatic polarization tests, and electrochemical impedance spectroscopy) and weight loss tests in a 1.6M H2SO4 solution with different concentrations of hydrochloric acid (0.00, 0.08, 0.15 and 0.20 M HCl) at 60 °C. The result showed that the corrosion rate decreased with increasing HCl by the formation of protective layers. SEM, EDS and XPS examinations of the corroded surfaces after the immersion test indicated that the corrosion production layer formed in the solution containing HCl was highly comprised of metallic Cu, Cu chloride and metallic (Fe, Cu, Sb) compounds. The corrosion resistance was improved by the Cu-enriched layer, in which chloride ions are an accelerator for cupric ion reduction during copper deposition. Furthermore, cuprous and antimonious chloride species are complex salts for cuprous ions adsorbed on the surface during copper deposition.

Ultra‐high performance supercritical fluid chromatography of lignin‐derived phenols from alkaline cupric oxide oxidation

Science.gov (United States)

Sun, Mingzhe; Lidén, Gunnar; Sandahl, Margareta

2016-01-01

Traditional chromatographic methods for the analysis of lignin‐derived phenolic compounds in environmental samples are generally time consuming. In this work, an ultra‐high performance supercritical fluid chromatography method with a diode array detector for the analysis of major lignin‐derived phenolic compounds produced by alkaline cupric oxide oxidation was developed. In an analysis of a collection of 11 representative monomeric lignin phenolic compounds, all compounds were clearly separated within 6 min with excellent peak shapes, with a limit of detection of 0.5–2.5 μM, a limit of quantification of 2.5–5.0 μM, and a dynamic range of 5.0–2.0 mM (R 2 > 0.997). The new ultra‐high performance supercritical fluid chromatography method was also applied for the qualitative and quantitative analysis of lignin‐derived phenolic compounds obtained upon alkaline cupric oxide oxidation of a commercial humic acid. Ten out of the previous eleven model compounds could be quantified in the oxidized humic acid sample. The high separation power and short analysis time obtained demonstrate for the first time that supercritical fluid chromatography is a fast and reliable technique for the analysis of lignin‐derived phenols in complex environmental samples. PMID:27452148

Assessing toxicity of varying major ion concentrations to marine organisms

International Nuclear Information System (INIS)

Mount, D.R.; Quast, W.

1993-01-01

Recent regulatory developments have required that produced waters discharged in the Gulf of Mexico be monitored for toxicity to marine organisms. While produced water may contain a variety of indigenous and introduced chemicals, virtually all have moderate to high concentrations of major ions. Although seawater is also rich in these ions, excessive salinity can cause toxicity to marine organisms. Perhaps more importantly, toxicity to marine organisms can be caused by deviations from normal ion ratios even if the total salinity is within organism tolerances. To provide a better understanding of marine organism responses to variations in major ion concentrations, the authors conducted a series of laboratory experiments to quantify the responses of mysid shrimp (Mysidopsis bahia) and sheepshead minnows (Cyprinodon variegatus) to modifications of normal seawater chemistry. Acute testing included both increasing and decreasing the concentrations of individual ions relative to seawater, as well as altering total salinity. Results show these organisms can be adversely affected by this altered chemistry and their sensitivity is dependent upon the individual ions that are manipulated. Results from these studies are being incorporated into an overall strategy for evaluating the influence of major ion chemistry on produced water toxicity tests

Variation and balance of positive air ion concentrations in a boreal forest

Directory of Open Access Journals (Sweden)

U. Hõrrak

2008-02-01

Full Text Available Air ions are characterized on the basis of measurements carried out in a boreal forest at the Hyytiälä SMEAR station, Finland, during the BIOFOR III campaign in spring 1999. The air ions were discriminated as small ions (charged molecular aggregates of the diameter of less than 2.5 nm, intermediate ions (charged aerosol particles of the diameter of 2.5–8 nm, and large ions (charged aerosol particles of the diameter of 8–20 nm. Statistical characteristics of the ion concentrations and the parameters of ion balance in the atmosphere are presented separately for the nucleation event days and non-event days. In the steady state, the ionization rate is balanced with the loss of small ions, which is expressed as the product of the small ion concentration and the ion sink rate. The widely known sinks of small ions are the recombination with small ions of opposite polarity and attachment to aerosol particles. The dependence of small ion concentration on the concentration of aerosol particles was investigated applying a model of the bipolar diffusion charging of particles by small ions. When the periods of relative humidity above 95% and wind speed less than 0.6 m s⁻¹ were excluded, then the small ion concentration and the theoretically calculated small ion sink rate were closely negatively correlated (correlation coefficient −87%. However, an extra ion loss term of the same magnitude as the ion loss onto aerosol particles is needed for a quantitative explanation of the observations. This term is presumably due to the small ion deposition on coniferous forest. The hygroscopic growth correction of the measured aerosol particle size distributions was also found to be necessary for the proper estimation of the ion sink rate. In the case of nucleation burst events, the concentration of small positive ions followed the general balance equation, no extra ion loss in addition to the deposition on coniferous forest was detected, and the

Electrodiffusive model for astrocytic and neuronal ion concentration dynamics.

Directory of Open Access Journals (Sweden)

Geir Halnes

Full Text Available The cable equation is a proper framework for modeling electrical neural signalling that takes place at a timescale at which the ionic concentrations vary little. However, in neural tissue there are also key dynamic processes that occur at longer timescales. For example, endured periods of intense neural signaling may cause the local extracellular K(+-concentration to increase by several millimolars. The clearance of this excess K(+ depends partly on diffusion in the extracellular space, partly on local uptake by astrocytes, and partly on intracellular transport (spatial buffering within astrocytes. These processes, that take place at the time scale of seconds, demand a mathematical description able to account for the spatiotemporal variations in ion concentrations as well as the subsequent effects of these variations on the membrane potential. Here, we present a general electrodiffusive formalism for modeling of ion concentration dynamics in a one-dimensional geometry, including both the intra- and extracellular domains. Based on the Nernst-Planck equations, this formalism ensures that the membrane potential and ion concentrations are in consistency, it ensures global particle/charge conservation and it accounts for diffusion and concentration dependent variations in resistivity. We apply the formalism to a model of astrocytes exchanging ions with the extracellular space. The simulations show that K(+-removal from high-concentration regions is driven by a local depolarization of the astrocyte membrane, which concertedly (i increases the local astrocytic uptake of K(+, (ii suppresses extracellular transport of K(+, (iii increases axial transport of K(+ within astrocytes, and (iv facilitates astrocytic relase of K(+ in regions where the extracellular concentration is low. Together, these mechanisms seem to provide a robust regulatory scheme for shielding the extracellular space from excess K(+.

determination of serum chloride ion concentration in pregnant

African Journals Online (AJOL)

Yusif

ABSTRACT. Serum chloride ion level in blood samples of pregnant women attending ante-natal care clinic in Minjibir was investigated. The mean and standard deviation of the ion in the samples is 100.51+ 4.89mmol/L. The distribution is skewed towards high frequency of low concentrations and could be attributed to.

Ultra-high performance supercritical fluid chromatography of lignin-derived phenols from alkaline cupric oxide oxidation.

Science.gov (United States)

Sun, Mingzhe; Lidén, Gunnar; Sandahl, Margareta; Turner, Charlotta

2016-08-01

Traditional chromatographic methods for the analysis of lignin-derived phenolic compounds in environmental samples are generally time consuming. In this work, an ultra-high performance supercritical fluid chromatography method with a diode array detector for the analysis of major lignin-derived phenolic compounds produced by alkaline cupric oxide oxidation was developed. In an analysis of a collection of 11 representative monomeric lignin phenolic compounds, all compounds were clearly separated within 6 min with excellent peak shapes, with a limit of detection of 0.5-2.5 μM, a limit of quantification of 2.5-5.0 μM, and a dynamic range of 5.0-2.0 mM (R(2) > 0.997). The new ultra-high performance supercritical fluid chromatography method was also applied for the qualitative and quantitative analysis of lignin-derived phenolic compounds obtained upon alkaline cupric oxide oxidation of a commercial humic acid. Ten out of the previous eleven model compounds could be quantified in the oxidized humic acid sample. The high separation power and short analysis time obtained demonstrate for the first time that supercritical fluid chromatography is a fast and reliable technique for the analysis of lignin-derived phenols in complex environmental samples. © 2016 The Authors, Journal of Separation Science Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Procedure for reducing hydrogen ion concentration in acidic anion eluate

International Nuclear Information System (INIS)

Parobek, P.; Baloun, S.; Plevac, S.

1992-01-01

A procedure is suggested for reducing the concentration of hydrogen ions in the acidic anionic eluate formed during the separation of uranium. The procedure involves anex elution, precipitation, filtration, precipitate rinsing, and anex rinsing. The procedure is included in the uranium elution process and requires at least one ion exchanger column and at least one tank in the continuous or discontinuous mode. Sparing the neutralizing agent by reducing the hydrogen ion concentration in the acidic anionic eluate is a major asset of this procedure. (Z.S.). 1 fig

In-vacuum scattered light reduction with black cupric oxide surfaces for sensitive fluorescence detection.

Science.gov (United States)

Norrgard, E B; Sitaraman, N; Barry, J F; McCarron, D J; Steinecker, M H; DeMille, D

2016-05-01

We demonstrate a simple and easy method for producing low-reflectivity surfaces that are ultra-high vacuum compatible, may be baked to high temperatures, and are easily applied even on complex surface geometries. Black cupric oxide (CuO) surfaces are chemically grown in minutes on any copper surface, allowing for low-cost, rapid prototyping, and production. The reflective properties are measured to be comparable to commercially available products for creating optically black surfaces. We describe a vacuum apparatus which uses multiple blackened copper surfaces for sensitive, low-background detection of molecules using laser-induced fluorescence.

Concentration Distribution of Chloride Ion under the Influence of the Convection-Diffusion Coupling

Directory of Open Access Journals (Sweden)

Q. L. Zhao

2017-01-01

Full Text Available The transfer process of chloride ion under the action of the convection-diffusion coupling was analyzed in order to predict the corrosion of reinforcement and the durability of structure more accurately. Considering the time-varying properties of diffusion coefficient and the space-time effect of the convection velocity, the differential equation for chloride ion transfer under the action of the convection-diffusion coupling was constructed. And then the chloride ion transfer model was validated by the existing experimental datum and the actual project datum. The results showed that when only diffusion was considered, the chlorine ion concentration increased with the time and decreased with the decay index of time. Under the action of the convection-diffusion coupling, at each point of coupling region, the chloride ion concentration first increased and then decreased and tended to stabilize, and the maximum appeared at the moment of convection velocity being 0; in the diffusion zone, the chloride ion concentration increased over time, and the chloride ion concentration of the same location increased with the depth of convection (in the later period, the velocity of convection (in the early period, and the chloride ion concentration of the surface.

Methods for obtaining a uniform volume concentration of implanted ions

International Nuclear Information System (INIS)

Reutov, V.F.

1995-01-01

Three simple practical methods of irradiations with high energy particles providing the conditions for obtaining a uniform volume concentration of the implanted ions in the massive samples are described in the present paper. Realization of the condition of two-sided irradiation of a plane sample during its rotation in the flux of the projectiles is the basis of the first method. The use of free air as a filter with varying absorbent ability due to movement of the irradiated sample along ion beam brought to the atmosphere is at the basis of the second method of uniform ion alloying. The third method for obtaining a uniform volume concentration of the implanted ions in a massive sample consists of irradiation of a sample through the absorbent filter in the shape of a foil curved according to the parabolic law moving along its surface. The first method is the most effective for obtaining a great number of the samples, for example, for mechanical tests, the second one - for irradiation in different gaseous media, and the third one - for obtaining high concentrations of the implanted ions under controlled (regulated) thermal and deformation conditions. 2 refs., 7 figs

Three-dimensional sponge-like architectured cupric oxides as high-power and long-life anode material for lithium rechargeable batteries

International Nuclear Information System (INIS)

Choi, Chung Seok; Park, Young-Uk; Kim, Hyungsub; Kim, Na Rae; Kang, Kisuk; Lee, Hyuck Mo

2012-01-01

Cupric oxide (CuO) nanoparticles (NPs) with three-dimensional (3D) sponge structure are obtained through the sintering of Cu NPs at 360 °C. Their morphology is analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), and their crystal structure is checked by X-ray diffraction. CuO NPs have a 3D porous structure. The NPs are assembled to form larger secondary particles with many empty spaces among them, and they have a CuO phase after the heat treatment. CuO NPs with this novel architecture exhibit good electrochemical performance as anode material. The anode material with a sponge-like structure is prepared at 360 °C, as the Li-ion battery exhibits a high electrochemical capacity of 674 mAh g −1 . When the sample is sintered at 360 °C, the charge/discharge capacities increase gradually and cycle up to 50 cycles at a C/10 rate, exhibiting excellent rate capability compared with earlier reported CuO/CuO-composite anodes. Electrochemical impedance spectroscopy (EIS) measurements suggest that the superior electrical conductivity of the sample sintered at 360 °C is the main factor responsible for the improved power capability.

Leaching of copper concentrates using NaCl and soluble copper contributed by the own concentrate

International Nuclear Information System (INIS)

Herrero, O.; Bernal, N.; Quiroz, R.; Fuentes, G.; Vinals, J.

2005-01-01

Leaching of copper concentrates using cupric chloro complexes, generated in situ by the reaction between Cu(II), aported by the soluble copper content of the concentrate, and sodium chloride in acid media was studied. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Chemical and mineralogical characterization from original concentrates was made. Typical variable such as a chloride concentration, soluble copper concentration, leaching time, solid percentage and temperature were studied. DRX and EDS analyzed some of the residues. the experimental results indicated that it is possible to obtain solutions having high copper content (15 to 35 g/L) and 2 to 5 g/L free acid in order to submit this solution directly to a solvent extraction stage. The leaching tests use common reactive and low cost such as sodium chloride and sulfuric acid. (Author) 16 refs

FY1995 development of novel processes for copper concentrates without producing sulfuric acid; 1995 nendo hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

To develop a novel process for copper concentrates which includes leaching of copper with acidic cupric chloride solutions, aiming at the recovery of sulfur in its elemental form, and leaching of gold from the residue with dissolved bromine. The effect of bromide ions on the leaching of chalcopyrite with 1.0 mol dm{sup -3} CuCl{sub 2} has been investigated at 353 K, and it was found that bromide ions have no influence on the leaching rate and the morphology of elemental sulfur deposited on the surface of chalcopyrite. Dissolved bromine has trivial effects on the morphology and oxidation of porous elemental sulfur covering the residue. However, the dissolved bromine even at 0.02 mol dm-3 depresses the leaching rate of chalcopyrite significantly. Electrotechnical oxidation of cuprous ions, chloride ions and bromide ions in the solution has examined to understand the regeneration of leachant, and it was found that these ions are oxidized simultaneously on the anode surface under the condition of galvanostatic electrolysis, but these oxidants diffuse toward the bulk of solution and react with their reductants. Thus the redox potential of the solution increases gradually showing the temporary stagnation in potential for oxidation of Cu{sup +}, Br{sup -} and Cl{sup -} ions respectively. (NEDO)

Biosynthesis of nano cupric oxide on cotton using Seidlitzia rosmarinus ashes utilizing bio, photo, acid sensing and leaching properties.

Science.gov (United States)

Bashiri Rezaie, Ali; Montazer, Majid; Rad, Mahnaz Mahmoudi

2017-12-01

In this research, a facile, rapid and eco-friendly method is introduced for synthesis and loading of cupric oxide on cellulosic chains of cotton fabric with functional properties. Seidlitzia rosmarinus ashes and copper acetate were employed as a natural source of alkaline and metal salt without further chemical materials. The treated samples indicated very good antibacterial activities toward both pathogen Staphylococcus aureus as Gram-positive and Escherichia coli as Gram-negative bacteria. Significant self-cleaning properties against degradation of methylene blue stain under UV irradiation were found. The sensing properties of high concentrated inorganic and organic acids such as sulfuric and formic acids based on colorimetric alterations of the treated fabrics were also confirmed showing acid leaching effects of the treated fabrics. Further, the treated samples showed coloring effects with an enhancement on the physio-mechanical properties including tensile strength, crease recovery angle and hydrophobocity. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Efficient Synthesis of Substituted Furans by Cupric Halide-Mediated Intramolecular Halocyclization of 2-(1-Alkynyl)-2-alken-1-ones

International Nuclear Information System (INIS)

Fu, Weijun; Guo, Wenbo; Zhu, Mei; Xu, Chen; Xu, Fengjuan

2013-01-01

An efficient synthesis of 3-halofurans by the intramolecular cyclization of 2-(1-alkynyl)-2-alken-1-ones with cupric halide has been developed. A broad range of 3-chloro- and 3-bromofuran derivatives could be obtained in the present method in moderate to good yields. The 3-halofuran derivatives are potential synthetic intermediates for amplification of molecular complexity

NTP technical report on the toxicity studies of Cupric Sulfate (CAS No. 7758-99-8) Administered in Drinking Water and Feed to F344/N Rats and B6C3F1 Mice.

Science.gov (United States)

Hebert, Charles

1993-07-01

Cupric sulfate is an inorganic salt which is widely used in industry, agriculture, and veterinary medicine. Its applications include use as an algicide in potable waters and as a feed additive and therapeutic agent in swine, sheep, and cattle. Because copper salts are found in human water supplies, toxicity studies of cupric sulfate pentahydrate were conducted in male and female F344/N rats and B6C3F1 mice by the drinking water (2-week studies only) and dosed feed routes (2-week and 13-week studies). Animals were evaluated for hematology, clinical chemistry, urinalysis, reproductive toxicity, tissue metal accumulation, and histopathology. In the 2-week drinking water studies, groups of five rats and five mice per sex received cupric sulfate at concentrations of 300 to 30,000 ppm for 15 days. One female rat, one male mouse, and three female mice in the 3000 ppm groups and all rats and mice in the 10,000 and 30,000 ppm groups died before the end of the studies. The remaining mice and rats in the 3000 ppm groups gained little or lost weight. Water consumption in the three highest dose groups of both species was reduced by more than 65%. Clinical signs observed in these groups were typical of those seen in moribund animals and were attributed to dehydration. The only gross or microscopic change specifically related to cupric sulfate toxicity was an increase in the size and number of cytoplasmic protein droplets in the epithelium of the renal proximal convoluted tubule in male rats from the 300 and 1000-ppm groups. In the 2-week feed studies, groups of five rats and five mice per sex were fed diets containing 1000 to 16,000 ppm cupric sulfate. No chemical-related deaths occurred in any dose group. Compared to the controls, rats and mice in the two highest dose groups had reduced body weight gains which were attributed to decreased feed consumption. Hyperplasia with hyperkeratosis of the squamous epithelium on the limiting ridge of the forestomach was seen in rats and

Effect of ion concentrations on uranium absorption from sodium carbonate solutions

International Nuclear Information System (INIS)

Traut, D.E.; El Hazek, N.M.T.; Palmer, G.R.; Nichols, I.L.

1979-01-01

The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated in order to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium

Direct seawater desalination by ion concentration polarization

Science.gov (United States)

Kim, Sung Jae; Ko, Sung Hee; Kang, Kwan Hyoung; Han, Jongyoon

2010-04-01

A shortage of fresh water is one of the acute challenges facing the world today. An energy-efficient approach to converting sea water into fresh water could be of substantial benefit, but current desalination methods require high power consumption and operating costs or large-scale infrastructures, which make them difficult to implement in resource-limited settings or in disaster scenarios. Here, we report a process for converting sea water (salinity ~500 mM or ~30,000 mg l-1) to fresh water (salinity water is divided into desalted and concentrated streams by ion concentration polarization, a phenomenon that occurs when an ion current is passed through ion-selective membranes. During operation, both salts and larger particles (cells, viruses and microorganisms) are pushed away from the membrane (a nanochannel or nanoporous membrane), which significantly reduces the possibility of membrane fouling and salt accumulation, thus avoiding two problems that plague other membrane filtration methods. To implement this approach, a simple microfluidic device was fabricated and shown to be capable of continuous desalination of sea water (~99% salt rejection at 50% recovery rate) at a power consumption of less than 3.5 Wh l-1, which is comparable to current state-of-the-art systems. Rather than competing with larger desalination plants, the method could be used to make small- or medium-scale systems, with the possibility of battery-powered operation.

Effects of ion concentration on the hydrogen bonded structure of ...

Indian Academy of Sciences (India)

WINTEC

Effects of ion concentration on the hydrogen bonded structure of water in the vicinity of ions in aqueous NaCl solutions. A NAG. 1. , D CHAKRABORTY and A CHANDRA*. Department of Chemistry, Indian Institute of Technology, Kanpur 208 016. 1. Present address: Department of Chemistry and Chemical Engineering,.

Determination of permeability of ultra-fine cupric oxide aerosol through military filters and protective filters

Science.gov (United States)

Kellnerová, E.; Večeřa, Z.; Kellner, J.; Zeman, T.; Navrátil, J.

2018-03-01

The paper evaluates the filtration and sorption efficiency of selected types of military combined filters and protective filters. The testing was carried out with the use of ultra-fine aerosol containing cupric oxide nanoparticles ranging in size from 7.6 nm to 299.6 nm. The measurements of nanoparticles were carried out using a scanning mobility particle sizer before and after the passage through the filter and a developed sampling device at the level of particle number concentration approximately 750000 particles·cm-3. The basic parameters of permeability of ultra-fine aerosol passing through the tested material were evaluated, in particular particle size, efficiency of nanoparticle capture by filter, permeability coefficient and overall filtration efficiency. Results indicate that the military filter and particle filters exhibited the highest aerosol permeability especially in the nanoparticle size range between 100–200 nm, while the MOF filters had the highest permeability in the range of 200 to 300 nm. The Filter Nuclear and the Health and Safety filter had 100% nanoparticle capture efficiency and were therefore the most effective. The obtained measurement results have shown that the filtration efficiency over the entire measured range of nanoparticles was sufficient; however, it was different for particular particle sizes.

Chiral recognition of proteins having L-histidine residues on the surface with lanthanide ion complex incorporated-molecularly imprinted fluorescent nanoparticles

International Nuclear Information System (INIS)

Uzun, Lokman; Uzek, Recep; Şenel, Serap; Say, Ridvan; Denizli, Adil

2013-01-01

In this study, lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles were synthesized. A combination of three novel approaches was applied for the purpose. First, lanthanide ions [Terbium(III)] were complexed with N-methacryloyl-L-histidine (MAH), polymerizable derivative of L-histidine amino acid, in order to incorporate the complex directly into the polymeric backbone. At the second stage, L-histidine molecules imprinted nanoparticles were utilized instead of whole protein imprinting in order to avoid whole drawbacks such as fragility, complexity, denaturation tendency, and conformation dependency. At the third stage following the first two steps mentioned above, imprinted L-histidine was coordinated with cupric ions [Cu(II)] to conduct the study under mild conditions. Then, molecularly imprinted fluorescent nanoparticles synthesized were used for L-histidine adsorption from aqueous solution to optimize conditions for adsorption and fluorimetric detection. Finally, usability of nanoparticles was investigated for chiral biorecognition using stereoisomer, D-histidine, racemic mixture, D,L-histidine, proteins with surface L-histidine residue, lysozyme, cytochrome C, or without ribonuclease A. The results revealed that the proposed polymerization strategy could make significant contribution to the solution of chronic problems of fluorescent component introduction into polymers. Additionally, the fluorescent nanoparticles reported here could be used for selective separation and fluorescent monitoring purposes. Highlights: • Lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles • Direct incorporation of the fluorescent complex into polymeric backbone. • Imprinting by assistance of cupric ion coordination into nanoparticles • Evaluation of the chiral biorecognition ability of nanoparticles • Simultaneous selective separation and fluorescent monitoring

Chiral recognition of proteins having L-histidine residues on the surface with lanthanide ion complex incorporated-molecularly imprinted fluorescent nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Uzun, Lokman, E-mail: lokman@hacettepe.edu.tr [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey); Uzek, Recep; Şenel, Serap [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey); Say, Ridvan [Anadolu University, Department of Chemistry, 26470, Eskisehir (Turkey); Denizli, Adil [Hacettepe University, Department of Chemistry, 06381, Ankara (Turkey)

2013-08-01

In this study, lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles were synthesized. A combination of three novel approaches was applied for the purpose. First, lanthanide ions [Terbium(III)] were complexed with N-methacryloyl-L-histidine (MAH), polymerizable derivative of L-histidine amino acid, in order to incorporate the complex directly into the polymeric backbone. At the second stage, L-histidine molecules imprinted nanoparticles were utilized instead of whole protein imprinting in order to avoid whole drawbacks such as fragility, complexity, denaturation tendency, and conformation dependency. At the third stage following the first two steps mentioned above, imprinted L-histidine was coordinated with cupric ions [Cu(II)] to conduct the study under mild conditions. Then, molecularly imprinted fluorescent nanoparticles synthesized were used for L-histidine adsorption from aqueous solution to optimize conditions for adsorption and fluorimetric detection. Finally, usability of nanoparticles was investigated for chiral biorecognition using stereoisomer, D-histidine, racemic mixture, D,L-histidine, proteins with surface L-histidine residue, lysozyme, cytochrome C, or without ribonuclease A. The results revealed that the proposed polymerization strategy could make significant contribution to the solution of chronic problems of fluorescent component introduction into polymers. Additionally, the fluorescent nanoparticles reported here could be used for selective separation and fluorescent monitoring purposes. Highlights: • Lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles • Direct incorporation of the fluorescent complex into polymeric backbone. • Imprinting by assistance of cupric ion coordination into nanoparticles • Evaluation of the chiral biorecognition ability of nanoparticles • Simultaneous selective separation and fluorescent monitoring.

Measurement of chloride-ion concentration with long-period grating technology

Science.gov (United States)

Tang, Jaw-Luen; Wang, Jian-Neng

2007-06-01

A simple and low-cost long-period fiber grating (LPG) sensor suited for chloride-ion concentration measurement is presented. The LPG sensor is found to be sensitive to the refractive index of the medium around the cladding surface of the sensing grating, thus offering the prospect of development of practical sensors such as an ambient index sensor or a chemical concentration indicator with high stability and reliability. We measured chloride ions in a typical concrete sample immersed in salt water solutions with different weight concentrations ranging from 0% to 25%. Results show that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for the concentration of salt in water solution is estimated to be 0.6% and the limit of detection for chloride ions is about 0.04%. To further enhance its sensitivity for chloride concentrations, we coated a monolayer of colloidal gold nanoparticles as the active material on the grating surface of the LPG sensor. The operating principle of sensing is based on the sensitivity of localized surface plasmon resonance of self-assembled gold colloids on the grating section of the LPG. With this method, a factor of two increase in the sensitivity of detecting chemical solution concentrations was obtained. The advantages of this type of fiber-optic sensor are that it is compact, relatively simple to construct and easy to use. Moreover, the sensor has the potential capability for on-site, in vivo and remote sensing, and it has potential use as a disposable sensor.

Preparation of the Hexacyanoferrate Ion Exchanger Matrix to Concentrate 137Cs from Sea Water

International Nuclear Information System (INIS)

Murdahayu Makmur

2007-01-01

Preparation of the hexacyanoferrate ion exchanger matrix to concentrate 137 Cs from large volume sea water has been done. The Pre-concentration is needed because 137 Cs concentration in sea water is too low. The hexacyanoferrate ion exchanger matrix can be prepared by performing the reaction of 10 gram silica gel with potassium hexacyanoferrate on concentration variation of 0.0025 M - 0.04 M and copper chloride on concentration variation of 0.005 M - 0.08 M. The volume of each reagent was 25 ml. The performance of the ion exchanger matrix depends on the chemical compositions both of the mixtures, it was expected that no remaining Fe ion and free Cu from the initial reagent. The final effluent will analyzed for Fe and Cu using Atomic Absorption Spectrometer. The optimal molar composition ration for potassium hexacyanoferrate and copper chloride was 0.5 for 10 gram silica gel. (author)

Change of pH and Iron Ion Concentration During Photodegradation of TCE with Ferrioxalate/UVvis Process

International Nuclear Information System (INIS)

Hareyama, Wataru; Suto, Koichi; Inoue, Chihiro; Chida, Tadashi; Nakazawa, Hiroshi

2006-01-01

Recently, some studies show various organic compounds such as pesticides and dyes degraded with the irradiation of ultraviolet light and visible light in the presence of oxalic acid and ferric ion (ferrioxalate/UVvis process). The process has much advance than other technologies because it can utilize the wavelength of 300∼450nm and also under the condition of neutral pH. Chlorinated organic compounds such as trichloroethene (TCE), which have caused ground water pollution on a lot of sites, have never been applied by photodegradation with this process. In this study, we showed the degradation of TCE in the presence of oxalic acid and iron ion and the change of pH, ferric and ferrous ion concentration during the photodegradation of TCE with ferrioxalate/UV-vis process. TCE was degraded in the presence of oxalic acid and iron ion. In the reactions, the equilibrium of oxalate ion and iron ion is important since it determines the amount of ferrioxalate complex which absorbs light and induces the reactions of the degradation of TCE. Thus, the pH value and iron ion concentration are the important factors which determine the amount of ferrioxalate complex. The pH is nearly constant during the photodegradation of TCE. The ferrous ion concentration was decreased as soon as beginning photodegradation of TCE, and then the ferrous ion concentration and ferric ion concentration became constant

A concentrated electrolyte for zinc hexacyanoferrate electrodes in aqueous rechargeable zinc-ion batteries

Science.gov (United States)

Kim, D.; Lee, C.; Jeong, S.

2018-01-01

In this study, a concentrated electrolyte was applied in an aqueous rechargeable zinc-ion battery system with a zinc hexacyanoferrate (ZnHCF) electrode to improve the electrochemical performance by changing the hydration number of the zinc ions. To optimize the active material, ZnHCF was synthesized using aqueous solutions of zinc nitrate with three different concentrations. The synthesized materials exhibited some differences in structure, crystallinity, and particle size, as observed by X-ray diffraction and scanning electron microscopy. Subsequently, these well-structured materials were applied in electrochemical tests. A more than two-fold improvement in the charge/discharge capacities was observed when the concentrated electrolyte was used instead of the dilute electrolyte. Additionally, the cycling performance observed in the concentrated electrolyte was superior to that in the dilute electrolyte. This improvement in the electrochemical performance may result from a decrease in the hydration number of the zinc ions in the concentrated electrolyte.

Cupric citrate as growth promoter for broiler chickens in different rearing stages Citrato cúprico como promotor de crescimento de frangos de corte diferentes em fases de criação

Directory of Open Access Journals (Sweden)

Mônica Maria de Almeida Brainer

2003-01-01

Full Text Available Feeding cupric citrate as alternative to cupric sulfate to broilers has been suggested in the literature. Day-old male broiler chicks (1,200 were used in an experiment to evaluate the efficacy of cupric citrate supplementation (75 mg Cu kg-1 during the 1-21, 22-42 or 1-42 d periods in comparison to an unsupplemented diet and a diet supplemented with cupric sulfate (200 mg Cu kg-1, 1-42 d. A randomized block design was used, with five treatments, six replicates and 40 birds per pen. The diets, based on corn and soybean meal, and water were offered ad libitum during the 42-day experimental period. Over the entire period, there was no effect of copper supplementation (P > 0.05 on bird live weight, weight gain, feed intake, feed conversion and mortality. Cupric citrate supplementation on the 22-42 d period resulted in worse feed conversion as compared to broilers receiving cupric sulfate (2.014 vs. 1.967, P Citrato cúprico foi apontado como alternativa ao sulfato cúprico como promotor de crescimento na dieta de frangos. Este trabalho avaliou a eficácia do citrato cúprico em diferentes fases da criação de frangos de corte. Foram utilizados 1200 pintos machos, em um experimento em blocos casualizados, com cinco tratamentos, seis repetições e 40 aves por parcela. Os tratamentos consistiram de uma dieta não suplementada ou suplementada com citrato cúprico anidro (75 mg Cu kg-1 de 1 a 21 dias, de 22 a 42 dias ou de 1 a 42 dias, ou com sulfato cúprico pentahidratado (200 mg Cu kg-1 de 1 a 42 dias. Foram avaliados o desempenho das aves e o resíduo de cobre na cama. Dietas, à base de milho e farelo de soja, e água foram fornecidas à vontade durante todo o período experimental. Não houve efeito da suplementação de cobre (P > 0,05 sobre o peso vivo, ganho de peso, consumo de ração, conversão alimentar e mortalidade mais refugagem. Os frangos que receberam citrato cúprico na ração a partir dos 22 dias tiveram, no período 22-42 dias

Natural variability in the surface ocean carbonate ion concentration

OpenAIRE

N. S. Lovenduski; M. C. Long; K. Lindsay

2015-01-01

We investigate variability in the surface ocean carbonate ion concentration ([CO32−]) on the basis of a long control simulation with a fully-coupled Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical...

Natural variability in the surface ocean carbonate ion concentration

OpenAIRE

Lovenduski, N. S.; Long, M. C.; Lindsay, K.

2015-01-01

We investigate variability in the surface ocean carbonate ion concentration ([CO32−]) on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical Pacific and ...

Determination of anionic concentrations in ground water samples using ion chromatography

International Nuclear Information System (INIS)

Prathibha, P.; Saradhi, I.V.; Pandit, G.G.; Puranik, V.D.

2011-01-01

Ion chromatography is a powerful separation technique for the quantitative measurement of anions in aqueous samples as well as in soil, sediment and air particulate samples leached in aqueous solutions. Ion chromatographic technique is developed by making use of suppressed ion conductivity detection (Small et.al.,1975) and it is a rapid multi ion analysis technique. The time, processing and effort required for the analysis of anions is much less compared to other techniques available such as ion selective electrode technique. In the present paper ground water samples collected around New BARC campus, Visakhapatnam are analyzed for anions using Ion chromatograph. The data generated will establish the current baseline status of the ionic contaminants in the study area. Groundwater samples are collected at 13 locations around BARC Vizag campus covering 30 km radius in September, 2009, April and July, 2010. The water samples include samples from hand pump and open wells in villages. The water samples are analyzed for fluoride, chloride, nitrate and sulphate using Metrohm make Ion chromatograph. The fluoride concentration in samples varied from 0.22 to 1.26 ppm, chloride from 18.7 to 810.9, nitrate from 1.34 to 378.5 ppm and sulphate from 13.29 to 250.69 ppm. No significant seasonal variations are observed in the samples collected from various locations except chloride at two locations. Ions Chromatograph is found to be a useful tool for simultaneous analysis of environmental samples with good accuracy where the concentrations of anions vary within an order of magnitude among them themselves. (author)

Chaotic Dynamics Mediates Brain State Transitions, Driven by Changes in Extracellular Ion Concentrations

DEFF Research Database (Denmark)

Rasmussen, Rune; H. Jensen, Mogens; L. Heltberg, Mathias

2017-01-01

Previous studies have suggested that changes in extracellular ion concentrations initiate the transition from an activity state that characterizes sleep in cortical neurons to states that characterize wakeful- ness. However, because neuronal activity and extra- cellular ion concentrations...... are interdependent, isolating their unique roles during sleep-wake transitions is not possible in vivo. Here, we extend the Averaged-Neuron model and demonstrate that, although changes in extracellular ion concentrations occur concurrently, decreasing the conductance of calcium-dependent potassium channels initiates...... the transition from sleep to wakefulness. We find that sleep is governed by stable, self-sustained oscillations in neuronal firing patterns, whereas the quiet awake state and active awake state are both governed by irregular oscillations and chaotic dynamics; transitions between these separable awake states...

Compact high-sensitivity potentiometer for detection of low ion concentrations in liquids

Science.gov (United States)

Balevicius, Z.; Lescinskas, R.; Celiesiute, R.; Stirke, A.; Balevicius, S.; Kersulis, S.; Bleizgys, V.; Maciuleviciene, R.; Ramanavicius, A.; Zurauskiene, N.

2018-04-01

The compact potentiometer, based on an electronic circuit protected from electrostatic and electromagnetic interference, was developed for the measurement of low ion concentrations in liquids. The electronic circuit of the potentiometer, consisting of analogous and digital parts, enables the measurement of fA currents. This makes it possible to perform reliable measurements of ion concentrations in liquids that are as small as 10-8-10-7M. The instrument was tested using electrodes that were selective for tetraphenylphosphonium (TPP+) ions. It was demonstrated that the characteristic response time of the potentiometer electronic circuit to changes in the concentration of these ions in a liquid was in the order of 10 s. An investigation of TPP+ absorption by baker yeast has shown that this device can be successfully used for long term (several hours) measurements with zero signal drift, which was about 1 μV/s. Finally, due to the small dimensions of the electronic circuit (7.5 × 2 × 1.5 cm), this potentiometer can be easily installed at a large apparatus in the laboratory condition (≈25 °C), such as high pulsed electrical generators of magnetic fields that are used in electroporation studies of biological cells.

Removal of Trace Elements by Cupric Oxide Nanoparticles from Uranium In Situ Recovery Bleed Water and Its Effect on Cell Viability

Science.gov (United States)

Schilz, Jodi R.; Reddy, K. J.; Nair, Sreejayan; Johnson, Thomas E.; Tjalkens, Ronald B.; Krueger, Kem P.; Clark, Suzanne

2015-01-01

In situ recovery (ISR) is the predominant method of uranium extraction in the United States. During ISR, uranium is leached from an ore body and extracted through ion exchange. The resultant production bleed water (PBW) contains contaminants such as arsenic and other heavy metals. Samples of PBW from an active ISR uranium facility were treated with cupric oxide nanoparticles (CuO-NPs). CuO-NP treatment of PBW reduced priority contaminants, including arsenic, selenium, uranium, and vanadium. Untreated and CuO-NP treated PBW was used as the liquid component of the cell growth media and changes in viability were determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in human embryonic kidney (HEK 293) and human hepatocellular carcinoma (Hep G2) cells. CuO-NP treatment was associated with improved HEK and HEP cell viability. Limitations of this method include dilution of the PBW by growth media components and during osmolality adjustment as well as necessary pH adjustment. This method is limited in its wider context due to dilution effects and changes in the pH of the PBW which is traditionally slightly acidic however; this method could have a broader use assessing CuO-NP treatment in more neutral waters. PMID:26132311

THE ROLE OF PIPE AGEING IN COPPER CORROSION BY-PRODUCT RELEASE

Science.gov (United States)

The presence of sulphate, bicarbonate and orthophosphate can change the type of solid present in systems containing cupric ion or cupric hydroxide solids. In some cases, a short-term reduction in copper solubility is realized, but over longer periods of time formation of basic c...

Potentiometric Sensor for Real-Time Monitoring of Multivalent Ion Concentrations in Molten Salt

International Nuclear Information System (INIS)

Zink, Peter A.; Jue, Jan-Fong; Serrano, Brenda E.; Fredrickson, Guy L.; Cowan, Ben F.; Herrmann, Steven D.; Li, Shelly X.

2010-01-01

Electrorefining of spent metallic nuclear fuel in high temperature molten salt systems is a core technology in pyroprocessing, which in turn plays a critical role in the development of advanced fuel cycle technologies. In electrorefining, spent nuclear fuel is treated electrochemically in order to effect separations between uranium, noble metals, and active metals, which include the transuranics. The accumulation of active metals in a lithium chloride-potassium chloride (LiCl-KCl) eutectic molten salt electrolyte occurs at the expense of the UCl3-oxidant concentration in the electrolyte, which must be periodically replenished. Our interests lie with the accumulation of active metals in the molten salt electrolyte. The real-time monitoring of actinide concentrations in the molten salt electrolyte is highly desirable for controlling electrochemical operations and assuring materials control and accountancy. However, real-time monitoring is not possible with current methods for sampling and chemical analysis. A new solid-state electrochemical sensor is being developed for real-time monitoring of actinide ion concentrations in a molten salt electrorefiner. The ultimate function of the sensor is to monitor plutonium concentrations during electrorefining operations, but in this work gadolinium was employed as a surrogate material for plutonium. In a parametric study, polycrystalline sodium beta double-prime alumina (Na-β(double p rime)-alumina) discs and tubes were subject to vapor-phase exchange with gadolinium ions (Gd3+) using a gadolinium chloride salt (GdCl3) as a precursor to produce gadolinium beta double-prime alumina (Gd-β(double p rime)-alumina) samples. Electrochemical impedance spectroscopy and microstructural analysis were performed on the ion-exchanged discs to determine the relationship between ion exchange and Gd3+ ion conductivity. The ion-exchanged tubes were configured as potentiometric sensors in order to monitor real-time Gd3+ ion concentrations in

LIGNOCELLULOSE NANOCOMPOSITE CONTAINING COPPER SULFIDE

Directory of Open Access Journals (Sweden)

Sanchi Nenkova

2011-04-01

Full Text Available Copper sulfide-containing lignocellulose nanocomposites with improved electroconductivity were obtained. Two methods for preparing the copper sulfide lignocellulose nanocomposites were developed. An optimization of the parameters for obtaining of the nanocomposites with respect to obtaining improved electroconductivity, economy, and lower quantities and concentration of copper and sulfur ions in waste waters was conducted. The mechanisms and schemes of delaying and subsequent connection of copper sulfides in the lignocellulosic matrix were investigated. The modification with a system of 2 components: cupric sulfate pentahydrate (CuSO4. 5H2O and sodium thiosulfate pentahydrate (Na2S2O3.5H2O for wood fibers is preferred. Optimal parameters were established for the process: 40 % of the reduction system; hydromodule M=1:6; and ratio of cupric sulfate pentahydrate:sodium thiosulfate pentahydrate = 1:2. The coordinative connection of copper ions with oxygen atoms of cellulose OH groups and aromatic nucleus in lignin macromolecule was observed.

Electrochemical methods to study hydrogen production during interaction of copper with deoxygenated aqueous solution

International Nuclear Information System (INIS)

Lilja, Christina; Betova, Iva; Bojinov, Martin

2016-01-01

In some countries, spent nuclear fuel is planned to be encapsulated in canisters with a copper shell for corrosion protection, for further disposal in geologic repositories. The possibilities for corrosion after oxygen depletion must be evaluated, even if copper is considered to be immune in oxygen-free water. To follow the interaction of copper with deoxygenated aqueous solution, open-circuit potentiometric and electrochemical impedance measurements have been coupled to in-situ detection of cupric ion, dissolved molecular hydrogen and oxygen concentrations using electrochemical sensors. A kinetic model that considers the production of hydrogen as a catalytic process, the rate of which is proportional to the surface coverage of an intermediate species formed during interaction between copper and the solution is used to interpret the results. Kinetic parameters are estimated by a simultaneous fit of the experimental impedance spectra, the open circuit potential and cupric ion concentration as depending on temperature (22–70 °C) and exposure time (up to 720 h) to the model equations. Using the obtained values and a balance equation of hydrogen production on copper and its diffusion out of the cell through its walls, the kinetic parameters of this process are estimated by fitting dissolved molecular hydrogen concentration vs. time data at the three temperatures.

Chromium and cobalt ion concentrations in blood and serum following various types of metal-on-metal hip arthroplasties

DEFF Research Database (Denmark)

Jantzen, Christopher; Jørgensen, Henrik L; Duus, Benn R

2013-01-01

Widely different metal ion concentrations in blood and serum have been reported with metal-on-metal (MoM) implants. We reviewed the literature on blood and serum ion concentrations of chromium (Cr) and cobalt (Co) following various MoM hip arthroplasties.......Widely different metal ion concentrations in blood and serum have been reported with metal-on-metal (MoM) implants. We reviewed the literature on blood and serum ion concentrations of chromium (Cr) and cobalt (Co) following various MoM hip arthroplasties....

Development of novel processes for Cu concentrates without producing sulfuric acid; Hiryusan hasseigata no atarashii doshigen shori gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Awakura, Y; Hirato, T [Kyoto University, Kyoto (Japan)

1997-02-01

Studies are conducted to develop a new wet method for copper concentrates to replace the conventional dry smelting method for the settlement of problems involving the processing of impurities for environmental protection. A specimen of pyrites polycrystals is subjected to leaching at 80 {degree}C in a strongly acidic cupric solution. Findings are that the element sulfur generated in this process does not impede leaching and only approximately 4% of the sulfur is oxidized into sulfur ions; that the presence of more than 2g/liter of bromide ions produced during bromine-aid leaching of gold changes the structure of sulfur for the inhibition of leaching; that circulation of a bromine-containing leaching liquid is not desired since even a small amount of approximately 0.02mol/liter inhibits the leaching rate. Controlled potential electrolysis is performed for the anode in an acid solution containing CuCl, NaCl, and NaBr, for the observation of oxidation/reduction potentials predicted by Nernst`s equation. It is then disclosed that bromine is more effective than chlorine in gold leaching and that the solution potential during leaching agent regeneration enables the monitoring of solution constitution. 2 refs.

Carbon Nanoparticles decorated with cupric oxide Nanoparticles prepared by laser ablation in liquid as an antibacterial therapeutic agent

Science.gov (United States)

Khashan, Khawla S.; Jabir, Majid S.; Abdulameer, Farah A.

2018-03-01

Carbon nanoparticles (CNPs) decorated with cupric oxide nanoparticles (CuO NPs) were prepared by laser ablation in water, and their antibacterial activity was examined. X-ray diffraction measurements demonstrated the presence of carbon phases and different CuO phases, and results were confirmed by Fourier transform infrared analysis. Energy- Dispersive spectra showed the presence of C, O, and Cu in the final product. Transmission electron micrographs revealed that the CNPs were 10-80 nm in size and spherical; after being decorated with CuO NPs, particles became 5-50 nm in size and uniform in shape. The absorption spectrum of decorated Nanoparticles indicated the appearance of a new peak at 254-264 nm in addition to the fundamental peak at 228 nm. We then examined the antibacterial activity of the decorated CNPs for both gram-negative and -positive bacteria using the agar-well-diffusion method. The mode of action was determined using acridine orange-ethidium bromide staining to detect reactive oxygen species, and bacterial morphological change was studied by scanning electron microscopy. Results showed that CNPs decorated with 43% CuO NPs had the highest antibacterial activity for gram-positive bacteria. The CNPs acted on the cytoplasmic membrane and nucleic acid of bacteria, which led to a loss of cell-wall integrity, increased cell-wall permeability, and nucleic acid damage. The results offer a novel way to synthesis Carbon nanoparticles decorated with cupric oxide nanoparticles and could use them as novel antibacterial agent in future for pharmaceutical and biomedical applications.

Effects of ion concentration on thermally-chargeable double-layer supercapacitors

Science.gov (United States)

Lim, Hyuck; Lu, Weiyi; Chen, Xi; Qiao, Yu

2013-11-01

The concept of thermally-chargeable supercapacitor was discussed and validated experimentally. As two double-layer supercapacitor-type devices were placed at different temperatures and connected, due to the thermal dependence of surface charge structures, the electrode potentials became different, and thermal energy could be harvested and stored as electric energy. The important effect of ion concentration was investigated. The results were quite different from the prediction of conventional surface theory, which should be attributed to the unique behaviors of the ions confined in the nanoporous electrodes.

Influence of hydrogen-ion concentration exponent on undrained shear behaviour of bentonites; Bentonaito no hihaisui sendan kyodo ni oyobosu suiso ion nodo shisu no eikyo

Energy Technology Data Exchange (ETDEWEB)

Kamei, T [Kiso Jiban Consultants Co. Ltd., Tokyo (Japan); Tokida, M [Nagano National College of Technology, Nagano (Japan)

1994-12-21

Because there is a report example that the yield stress of a landslide clay increases along with a decrease of a hydrogen-ion concentration exponent, it is thought that a shear strength of the landslide clay depends on the hydrogen-ion concentration exponent. Furthermore, when the soil stabilization method by lime is applied to the soft ground and high organic earth, it is pointed out that the hydrogen-ion concentration exponent will become one of the harmful factors. Accordingly, it is understood that revealing an influence of a hydrogen-ion concentration exponent affects on the characteristics of an earth is one of the important factors, to evaluate a strength, deformation and so forth of the viscous ground. In this study, in order to examine an influence of a hydrogen-ion concentration exponent affecting on an undrained shear behavior of the bentonites, for the artificially adjusted bentonite specimens with 5 kinds of different pH, the isotropic consolidated undrained triaxial compression tests were performed, and consequently an influence of pH affecting on the engineering characteristics of the bentonites was made clear quantitatively. 28 refs., 16 figs., 5 tabs.

The effect of hydrogen peroxide concentration on metal ion release from dental casting alloys.

Science.gov (United States)

Al-Salehi, S K; Hatton, P V; Johnson, A; Cox, A G; McLeod, C

2008-04-01

There are concerns that tooth bleaching agents may adversely affect dental materials. The aim of this study was to test the hypothesis that increasing concentrations of hydrogen peroxide (HP) are more effective than water at increasing metal ion release from two typical dental casting alloys during bleaching. Discs (n = 28 for each alloy) were prepared by casting and heat treated to simulate a typical porcelain-firing cycle. Discs (n = 7) of each alloy were immersed in either 0%, 3%, 10% or 30% (w/v) HP solutions for 24 h at 37 degrees C. Samples were taken for metal ion release determination using inductively coupled plasma-mass spectrometry and the data analysed using a two-way anova followed by a one-way anova. The surface roughness of each disc was measured using a Talysurf contact profilometer before and after bleaching and the data analysed using a paired t-test. With the exception of gold, the differences in metal ion concentration after treatment with 0% (control) and each of 3%, 10% and 30% HP (w/v) were statistically significant (P alloys increased with increasing HP concentrations (over 3000% increase in Ni and 1400% increase in Pd ions were recorded when HP concentration increased from 0% to 30%). Surface roughness values of the samples before and after bleaching were not significantly different (P > 0.05) Exposure of the two dental casting alloys to HP solutions increased metal ion release of all the elements except gold.

Concentrated ion beam emitted from an enlarged cylindrical-anode-layer Hall plasma accelerator and mechanism

Energy Technology Data Exchange (ETDEWEB)

Geng, S. F.; Wang, C. X. [Southwestern Institute of Physics, Chengdu 610041 (China); Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong); Tang, D. L.; Qiu, X. M. [Southwestern Institute of Physics, Chengdu 610041 (China); Chu, Paul K. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon (Hong Kong)

2013-01-28

An enlarged cylindrical-anode-layer Hall plasma accelerator with an outlet diameter of 150 mm is experimentally demonstrated to produce a concentrated ion beam, especially at a high discharge voltage, with a high current utilization efficiency of up to {approx}0.9. Numerical investigation based on the three-dimensional particle-in-cell method is performed to study the ion dynamics and elucidate the origin of the ion beam characteristics. The simulation results reveal that the equipotential lines play an important role in the surface near the anode emitting the ions. The ion emitting surface is determined by the magnetic field lines near the anode and the magnetic mirror contributes to the concentrated beam significantly. The high current utilization efficiency results from the appropriate obliquity of the magnetic mirror.

Reduced blood flow increases the in vivo ammonium ion concentration in the RIF-1 tumor

International Nuclear Information System (INIS)

Constantinidis, Ioannis; Gamcsik, Michael P.

1995-01-01

Purpose: Previous studies from our laboratory have suggested that pooling of ammonium in tumor tissues may be caused by its inefficient removal due to the poor vasculature commonly found in tumors. The purpose of these experiments was to validate the relationship between tumor ammonium ion concentration and tumor blood flow, and to determine whether large concentrations of ammonium ion detected by Nuclear Magnetic Resonance (NMR) spectroscopy are either produced within the tumor or simply imported into the tumor through the blood stream. Methods and Materials: To test this hypothesis, we reduced blood flow in subcutaneously grown Radiation Induced Fibrosarcoma-1 (RIF-1) tumors, either by creating partial ischemia with a bolus injection of hydralazine or by occlusion with surgical sutures. 14 N and 31 P NMR spectroscopy were used to detect the presence of ammonium, and to assess the bioenergetic status of the tumors, respectively. Results: A correlation between ammonium ion concentration and (PCr(P i )) ratio was established for untreated tumors. An increase in the in vivo tumor ammonium ion concentration was observed for every tumor that experienced a reduction in blood flow caused by either hydralazine injection or suture ligation. Changes in ammonium ion concentration paralleled changes in the bioenergetics of hydralazine-treated tumors. Conclusion: Our results support the hypothesis that a reduction in tumor blood flow is responsible for the accumulation of ammonium in tumors, and that detected ammonium originated from within the tumor

A Microfluidic Long-Period Fiber Grating Sensor Platform for Chloride Ion Concentration Measurement

Directory of Open Access Journals (Sweden)

Jian-Neng Wang

2011-09-01

Full Text Available Optical fiber sensors based on waveguide technology are promising and attractive in chemical, biotechnological, agronomy, and civil engineering applications. A microfluidic system equipped with a long-period fiber grating (LPFG capable of measuring chloride ion concentrations of several sample materials is presented. The LPFG-based microfluidic platform was shown to be effective in sensing very small quantities of samples and its transmitted light signal could easily be used as a measurand. The investigated sample materials included reverse osmosis (RO water, tap water, dilute aqueous sample of sea sand soaked in RO water, aqueous sample of sea sand soaked in RO water, dilute seawater, and seawater. By employing additionally a chloride ion-selective electrode sensor for the calibration of chloride-ion concentration, a useful correlation (R2 = 0.975 was found between the separately-measured chloride concentration and the light intensity transmitted through the LPFG at a wavelength of 1,550 nm. Experimental results show that the sensitivity of the LPFG sensor by light intensity interrogation was determined to be 5.0 × 10−6 mW/mg/L for chloride ion concentrations below 2,400 mg/L. The results obtained from the analysis of data variations in time-series measurements for all sample materials show that standard deviations of output power were relatively small and found in the range of 7.413 × 10−5–2.769 × 10−3 mW. In addition, a fairly small coefficients of variations were also obtained, which were in the range of 0.03%–1.29% and decreased with the decrease of chloride ion concentrations of sample materials. Moreover, the analysis of stability performance of the LPFG sensor indicated that the random walk coefficient decreased with the increase of the chloride ion concentration, illustrating that measurement stability using the microfluidic platform was capable of measuring transmitted optical power with accuracy in the range of −0

Parametrics for Molecular Deuterium Concentrations in the Source Region of the UW-IEC Device Using an Ion Acoustic Wave Diagnostic

Science.gov (United States)

Boris, D. R.; Emmert, G. A.

2007-11-01

The ion source region of the UW-Inertial Electrostatic Confinement device is comprised of a filament assisted DC discharge plasma that exists between the wall of the IEC vacuum chamber and the grounded spherical steel grid that makes up the anode of the IEC device. A 0-dimensional rate equation calculation of the molecular deuterium ion species concentration has been applied utilizing varying primary electron energy, and neutral gas pressure. By propagating ion acoustic waves in the source region of the IEC device the concentrations of molecular deuterium ion species have been determined for these varying plasma conditions, and high D3^+ concentrations have been verified. This was done by utilizing the multi-species ion acoustic wave dispersion relation, which relates the phase speed of the multi-species ion acoustic wave, vph, to the sum in quadrature of the concentration weighted ion acoustic sound speeds of the individual ion species.

Multisite Ion Model in Concentrated Solutions of Divalent Cations (MgCl2 and CaCl2): Osmotic Pressure Calculations

Science.gov (United States)

2015-01-01

Accurate force field parameters for ions are essential for meaningful simulation studies of proteins and nucleic acids. Currently accepted models of ions, especially for divalent ions, do not necessarily reproduce the right physiological behavior of Ca2+ and Mg2+ ions. Saxena and Sept (J. Chem. Theor. Comput.2013, 9, 3538–3542) described a model, called the multisite-ion model, where instead of treating the ions as an isolated sphere, the charge was split into multiple sites with partial charge. This model provided accurate inner shell coordination of the ion with biomolecules and predicted better free energies for proteins and nucleic acids. Here, we expand and refine the multisite model to describe the behavior of divalent ions in concentrated MgCl2 and CaCl2 electrolyte solutions, eliminating the unusual ion–ion pairing and clustering of ions which occurred in the original model. We calibrate and improve the parameters of the multisite model by matching the osmotic pressure of concentrated solutions of MgCl2 to the experimental values and then use these parameters to test the behavior of CaCl2 solutions. We find that the concentrated solutions of both divalent ions exhibit the experimentally observed behavior with correct osmotic pressure, the presence of solvent separated ion pairs instead of direct ion pairs, and no aggregation of ions. The improved multisite model for (Mg2+ and Ca2+) can be used in classical simulations of biomolecules at physiologically relevant salt concentrations. PMID:25482831

Reactivity of the cadmium ion in concentrated phosphoric acid solutions.

Science.gov (United States)

De Gyves, J; Gonzales, J; Louis, C; Bessiere, J

1989-07-01

The solvation transfer coefficients which characterize the changes of ion reactivity with phosphoric acid concentration have been calculated for cadmium from the constants of the successive chloride complexes, and for silver and diethyldithiophosphate from potentiometric measurements. They evidence the strong desolvation of the cadmium species in concentrated phosphoric acid media, causing a remarkable increase of its reactivity. They allow the results of liquid-liquid extraction, precipitation and flotation reactions to be correctly interpreted and their changes to be foreseen when the reagents are modified.

Modeling the concentration-dependent permeation modes of the KcsA potassium ion channel.

Science.gov (United States)

Nelson, Peter Hugo

2003-12-01

The potassium channel from Streptomyces lividans (KcsA) is an integral membrane protein with sequence similarity to all known potassium channels, particularly in the selectivity filter region. A recently proposed model for ion channels containing either n or (n-1) single-file ions in their selectivity filters [P. H. Nelson, J. Chem. Phys. 177, 11396 (2002)] is applied to published KcsA channel K+ permeation data that exhibit a high-affinity process at low concentrations and a low-affinity process at high concentrations [M. LeMasurier et al., J. Gen. Physiol. 118, 303 (2001)]. The kinetic model is shown to provide a reasonable first-order explanation for both the high- and low-concentration permeation modes observed experimentally. The low-concentration mode ([K+]200 mM) has a 200-mV dissociation constant of 1100 mM and a conductance of 500 pS. Based on the permeation model, and x-ray analysis [J. H. Morais-Cabral et al., Nature (London) 414, 37 (2001)], it is suggested that the experimentally observed K+ permeation modes correspond to an n=3 mechanism at high concentrations and an n=2 mechanism at low concentrations. The ratio of the electrical dissociation distances for the high- and low-concentration modes is 3:2, also consistent with the proposed n=3 and n=2 modes. Model predictions for K+ channels that exhibit asymmetric current-voltage (I-V) curves are presented, and further validation of the kinetic model via molecular simulation and experiment is discussed. The qualitatively distinct I-V characteristics exhibited experimentally by Tl+, NH+4, and Rb+ ions at 100 mM concentration can also be explained using the model, but more extensive experimental tests are required for quantitative validation of the model predictions.

Removing ferric ions from concentrated acid leaching solution of an uranium ore by jarosite

International Nuclear Information System (INIS)

Song Huanbi; Hu Yezang

1997-01-01

The author expounds the fundamental rules of removing ferric ions by jarosite and presents results of removing ferric ions from concentrated acid curing-trickle leaching solution of an uranium ore. It turns out that the method can be applied to uranium hydrometallurgical process effectively

Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

Science.gov (United States)

Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

2015-07-01

A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P0.05), and the quadratic effects of copper ion concentration were significant ( P0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring

Directory of Open Access Journals (Sweden)

Shuangxi Zhou

2017-12-01

Full Text Available In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring.

Science.gov (United States)

Zhou, Shuangxi; Sheng, Wei; Deng, Fangming; Wu, Xiang; Fu, Zhihui

2017-12-11

In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

Acrylamide graft over silicone rubber tubes by simultaneous irradiation in 60 Co source

International Nuclear Information System (INIS)

Julio, C.A.; Higa, O.Z.

1992-01-01

The synthesis of a hydrogel having silicone rubber tubes as support was carried out through the radiation grafting technique. The best conditions for the grafting development were determined in relation to the monomer and inhibitor concentration, dose rate and irradiation dose. The addition of cupric ions in the process inhibited the acrylamide homo polymerization and enhanced the grafting yield. The water content in the grafted tubes characterized the hydrophilic property of the material. (author)

Spectroscopic Analysis of Ion Concentration Profile at Electrode/Electrolyte Interface by Interferometry

Science.gov (United States)

Moore, David; Saraf, Ravi

2014-03-01

Owing to the difference in Fermi levels at an electrode/electrolyte interface, ions form an electrical double layer (EDL) with ion concentrations well over 10-fold compared to bulk. The concentration profile of the EDL intrinsically affects the electrochemical reaction rates at the electrode, which is of great significance in many applications, such as batteries and biosensors. Conventionally, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), the electrical properties of the EDL are represented as ``equivalent circuits'' consisting of the resistance to charge transfer (Rct), the double layer capacitance (Cdl) and a ``Warburg (constant phase) diffusion element'' that represents the long range diffusion of ions to the electrode. The translation to the well-understood physical structure can be lost as complicated effects are often lumped together. For example, the effect of subtle modification of the electrode surface by say, redox compounds, enzymes, or polymers is not directly measured, and must be inferred by capacitance changes. An interferometer method will be described to directly measure changes in concentration at the interface during redox process. This method in concert with CV or EIS performed concomitantly will lead to more information to model the diffuse layer for improved understanding of the kinetics of the reaction at different distances from the electrode. Applications to DNA and polymer adsorption binding will be discussed.

Concentration and purification of plutonium solutions by means of ion-exchange columns

Energy Technology Data Exchange (ETDEWEB)

Durham, R W; Aikin, A M

1953-02-15

Equilibrium experiments using Dowex 50 ion-exchange resin and nitric acid solutions of Pu{sup 3+}, UO{sub 2}{sup 2+}, Fe{sup 2+} cations have yielded values for the absorption affinities for these ions. Trivalent plutonium was found to be far more strongly absorbed than UO{sub 2}{sup 2+} and Fe{sup 2+}. Column studies have shown that uranium can be completely separated from plutonium even when the initial concentration of uranium is very much greater than that of the plutonium. A plutonium concentration increase of about fifty-fold can be obtained from solutions about 10{sup -3} M in plutonium and 1.0M in nitric acid. The equation K{sub Pu}{sup 3+} = X{sub R} (1-X{sub S}){sup 3} C{sub S}{sup 2}/X{sub S} (1-X{sub R}){sup 3} C{sub R}{sup 2} for estimating the maximum amount of plutonium taken up by a column of resin of unit volume from a solution of total equivalent concentration, C{sub S} , has been shown to hold for values of C{sub S} up to 3 equivalents per litre. X{sub R}, the equivalent fraction of plutonium on the resin, is the number of equivalents of plutonium absorbed by the resin divided by the total capacity of the column. X{sub S}, the equivalent fraction of plutonium in solution, is the equivalent concentration of plutonium divided by the total equivalent concentration of cations in solution. C{sub R} is the total capacity of the resin in milli-equivalents per gram of dry resin. Recommendations have been made for the application and operation of ion-exchange columns in the Plutonium-Extraction Plant. (author)

Diffusion of ion-implanted B in high concentration P- and As-doped silicon

International Nuclear Information System (INIS)

Fair, R.B.; Pappas, P.N.

1975-01-01

The diffusion of ion-implanted B in Si in the presence of a uniform background of high concentration P or As was studied by correlating numerical profile calculations with profiles determined by secondary-ion mass spectrometry (SIMS). Retarded B diffusion is observed in both As- and P-doped Si, consistent with the effect of the local Fermi-level position in the Si band gap on B diffusivity, D/sub B/. It is shown that D/sub B/ is linearly dependent on the free hole concentration, p, over the range 0.1 less than p/n/sub ie/ less than 30, where n/sub ie/ is the effective intrinsic electron concentration. This result does not depend on the way in which the background dopant has been introduced (implantation predeposition or doped-oxide source), nor the type of dopant used (P or As). (U.S.)

Integrated Microanalytical System for Simultaneous Voltammetric Measurements of Free Metal Ion Concentrations in Natural Waters

OpenAIRE

Noël, Stéphane; Tercier-Waeber, Mary-Lou; Lin, Lin; Buffle, Jacques; Guenat, Olivier; Koudelka-Hep, Milena

2007-01-01

A complexing gel integrated microelectrode (CGIME) for direct measurements of free metal ion concentrations in natural waters has been developed. It is prepared by the successive deposition of microlayers of a chelating resin, an antifouling agarose gel and Hg on a 100-interconnected Ir-based microelectrode array. The trace metals of interest are in a first step accumulated on the chelating resin in proportion to their free ion concentration in solution, then released in acidic solution and d...

Leaching of copper concentrates using NaCl and soluble copper contributed by the own concentrate; Lixiviacion de concentrados de cobre utilizando NaCl y el cobre soluble aportado por el propio concentrado

Energy Technology Data Exchange (ETDEWEB)

Herrero, O.; Bernal, N.; Quiroz, R.; Fuentes, G.; Vinals, J.

2005-07-01

Leaching of copper concentrates using cupric chloro complexes, generated in situ by the reaction between Cu(II), aported by the soluble copper content of the concentrate, and sodium chloride in acid media was studied. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Chemical and mineralogical characterization from original concentrates was made. Typical variable such as a chloride concentration, soluble copper concentration, leaching time, solid percentage and temperature were studied. DRX and EDS analyzed some of the residues. the experimental results indicated that it is possible to obtain solutions having high copper content (15 to 35 g/L) and 2 to 5 g/L free acid in order to submit this solution directly to a solvent extraction stage. The leaching tests use common reactive and low cost such as sodium chloride and sulfuric acid. (Author) 16 refs.

[On-line analysis and mass concentration characters of the alkali metal ions of PM10 in Beijing].

Science.gov (United States)

Zhang, Kai; Wang, Yue-Si; Wen, Tian-Xue; Liu, Guang-Ren; Hu, Bo; Zhao, Ya-Nan

2008-01-01

The mass concentration characters and the sources of water-soluble alkali metal ions in PM10 in 2004 and 2005 in Beijing were analyzed by using the system of rapid collection of particles. The result showed that the average concentration of Na+, K+, Mg2+ and Ca2+ was 0.5-1.4, 0.5-2.5, 0.1-0.5 and 0.6-5.8 microg/m3, respectively. The highest and lowest concentration appeared in different seasons for the alkali metal ions, which was related to the quality and source. The concentration of alkali metal ions was no difference between the heating period and no heating period, which meant the heating was not the main source. Sea salt and soil were the important sources of Na+. The source of K+ came from biomass burning and vegetation. Soil was the large source of Mg2+ and Ca2+. The alkali metal ions appeared different daily variation in different seasons. Precipitation could decrease the concentration of Na+, K+, Mg2+ and Ca2+, which was 10%-70%, 20%-80%, 10%-77%, 5%-80% respectively.

Application of the atomic absorption technical to available the concentration of silver ions incorporated in glass matrix by ionic exchange process

International Nuclear Information System (INIS)

Mendes, E.; Silva, K.F.; Teixeira, A.; Silva, L.; Paula, M.M.S.; Angioletto, E.; Riella, H.G.; Fiori, M. A.

2009-01-01

Ion specimens can be incorporated in glasses or natural clays by ionic exchange process with different concentrations dependent of matrix's type and of the ionic exchange parameters. In particular, the incorporation of silver ions presents high interest by its biocidal properties. A compound contending ion silver specimens presents bactericidal and fungicidal properties with effect proportional to ion concentration. This work presents results about application of the atomic absorption technical to determine the silver ion concentration incorporated in a glass matrix by ionic exchange process. The ionic exchange experiments were realized with different AgNO 3 concentration and constant temperature. After ionic exchange process, the glass samples were submitted to characterization by Energy Dispersive X-Ray Spectroscopy and Atomic Absorption Techniques. The comparative results between different techniques showed that atomic absorption technical is adequate to determine ion silver concentration incorporated in the glass matrix after ionic exchange process. (author)

Highly sensitive colour change system within slight differences in metal ion concentrations based on homo-binuclear complex formation equilibrium for visual threshold detection of trace metal ions

International Nuclear Information System (INIS)

Mizuguchi, Hitoshi; Atsumi, Hiroshi; Hashimoto, Keigo; Shimada, Yasuhiro; Kudo, Yuki; Endo, Masatoshi; Yokota, Fumihiko; Shida, Junichi; Yotsuyanagi, Takao

2004-01-01

A new technique of expressing slight differences in metal ion concentrations by clear difference in colour was established for visual threshold detection of trace metal ions. The proposed method is based on rapid change of the mole fraction of the homo-binuclear complex (M 2 L) about a ligand in a narrow range of the total metal ion concentration (M T ) in a small excess, in case the second metal ion is bound to the reagent molecule which can bind two metal ions. Theoretical simulations showed that the highly sensitive colour change within slight differences in metal ion concentrations would be realized under the following conditions: (i) both of the stepwise formation constants of complex species are sufficiently large; (ii) the stepwise formation constant of the 1:1 complex (ML) is larger than that of M 2 L; and (iii) the absorption spectrum of M 2 L is far apart from the other species in the visible region. Furthermore, the boundary of the colour region in M T would be readily controlled by the total ligand concentration (L T ). Based on this theory, the proposed model was verified with the 3,3'-bis[bis(carboxymethyl)amino]methyl derivatives of sulphonephthalein dyes such as xylenol orange (XO), methylthymol blue (MTB), and methylxylenol blue (MXB), which can bind two metal ions at both ends of a π-electron conjugated system. The above-mentioned model was proved with the iron(III)-XO system at pH 2. In addition, MTB and MXB were suitable reagents for the visual threshold detection of trivalent metal ions such as iron(III), aluminium(III), gallium(III) and indium(III) ion in slightly acidic media. The proposed method has been applied successfully as a screening test for aluminium(III) ion in river water sampled at the downstream area of an old mine

Anion analysis in uranium more concentrates by ion chromatography

International Nuclear Information System (INIS)

Badaut, V.

2009-01-01

In the present exploratory study, the applicability of anionic impurities or attributing nuclear material to a certain chemical process or origin has been investigated. Anions (e.g., nitrate, sulphate, fluoride, chloride) originate from acids or salt solutions that are used for processing of solutions containing uranium or plutonium. The study focuses on uranium ore concentrates ('yellow cakes') originating from different mines. Uranium is mined from different types of ore body and depending on the type of rock, different chemical processes for leaching, dissolving and precipitating the uranium need to be applied. Consequently, the anionic patterns observed in he products of these processes (the 'ore concentrates') are different. The concentrations of different anionic species were measured by ion chromatography using conductivity detection. The results show clear differences of anion concentrations and patterns between samples from different uranium mines. Besides this, differences between sampling campaigns n a same mine were also observed indicating that the uranium ore is not homogeneous in a mine. These within-mine variations, however, were smaller than the between-mine variations. (author)

Concentration effect on the spectroscopic behavior of Tb3+ ions in zinc phosphate glasses

International Nuclear Information System (INIS)

Kesavulu, C.R.; Almeida Silva, Anielle Christine; Dousti, M.R.; Dantas, Noelio Oliveira; Camargo, A.S.S. de; Catunda, Tomaz

2015-01-01

Zinc phosphate glasses (PZABPTb) in the compositional system: P 2 O 5 –ZnO–Al 2 O 3 –BaO–PbO doped with variable Tb 3+ concentrations (1–5 wt% Tb 2 O 3 ) were prepared and characterized through absorption, excitation, emission and intensity decay rate measurements. The Judd–Ofelt model has been adopted to evaluate the radiative properties of the 5 D 4 → 7 F 6–3 emission transitions. The effect of Tb 3+ ion concentration on the emissions from the 5 D 3,4 excited levels is discussed in detail. Analysis of the intensity decay curves corresponding to blue and green emissions from levels 5 D 3 and 5 D 4 , respectively, allowed determination of effective lifetimes, which confirmed the Tb 3+ ion concentration quenching of the blue emission in these glasses. The decay curves for the 5 D 3 level are found to be non-exponential in nature for all the studied concentrations due to ion–ion energy transfer through cross-relaxation. In an attempt to identify the origin of the energy transfer mechanism, the decay curves were well fitted to the Inokuti–Hirayama model for S=6, which indicates that the energy transfer process is of dipole–dipole type. The optical band gap energy (E opt ) has been evaluated taking into account the ultraviolet edge of absorption spectra. - Highlights: • Tb 3+ -doped zinc phosphate glasses have been prepared by melt quenching technique. • Spectroscopic parameters were evaluated using the Judd–Ofelt theory. • Effects of Tb 3+ concentration on luminescence of the glasses were studied. • Strong intense laser transition for Tb 3+ ion in PZABPTb glasses is 5 D 4 → 7 F 5 (0.54 μm). • PZABPTb glasses could be used in the development of green color display devices and solid state visible lasers

Continuous measurement of the radon concentration in water using electret ion chamber method

International Nuclear Information System (INIS)

Dua, S.K.; Hopke, P.K.

1992-10-01

A radon concentration of 300 pCi/L has been proposed by the US Environmental Protection Agency as a limit for radon dissolved in municipal drinking water supplies. There is therefore a need for a continuous monitor to insure that the daily average concentration does not exceed this limit. In order to calibrate the system, varying concentrations of radon in water have been generated by bubbling radon laden air through a dynamic flowthrough water system. The value of steady state concentration of radon in water from this system depends on the concentration of radon in air, the air bubbling rate, and the water flow rate. The measurement system has been designed and tested using a 1 L volume electret ion chamber to determine the radon in water. In this dynamic method, water flows directly through the electret ion chamber. Radon is released to the air and measured with the electret. A flow of air is maintained through the chamber to prevent the build-up of high radon concentrations and too rapid discharge of the electret. It was found that the system worked well when the air flow was induced by the application of suction. The concentration in the water was calculated from the measured concentration in air and water and air flow rates. Preliminary results suggest that the method has sufficient sensitivity to measure concentrations of radon in water with acceptable accuracy and precision

Studies on measurement of chloride ion concentration in concrete structures with long-period grating sensors

Science.gov (United States)

Tang, Jaw-Luen; Chiang, Tsung-Yu; Chang, Hsiang-Ping; Wang, Jian-Neng

2006-03-01

We report the development and demonstration of a simple and low-cost long-period grating (LPG) sensor for chloride ion concentration measurement in concrete structures. The LPG sensor is extremely sensitive to the refractive index of the medium surrounding the cladding surface of the sensing grating, thus allowing it to be used as an ambient index sensor or chemical concentration indicator with high stability and reliability. We have measured chloride ion levels in a concrete sample immersed in salt water solution with different weight concentration ranging from 0 % to 20 %, and results showed that the LPG sensor exhibited a linear decrease in the transmission loss and resonance wavelength shift when the concentration increased. The measurement accuracy for concentration of salt in water solution is estimated to be 0.6 % and the limit of detection for chloride ion is about 0.04 %. To further enhance its sensitivity for chloride concentrations, we have coated gold nanoparticles on the grating surface of the LPG sensor. The sensing mechanism is based on the sensitivity of localized surface plasmon resonance of self-assembled Au colloids on the grating portion of the LPG. With this method, a factor of two increases in sensitivity of detecting chemical solution concentrations was obtained. The advantage of this type of the sensor is relatively simple of construction and ease of use. Moreover, the sensor has the potential capability for on-site, in vivo, and remote sensing, and has the potential use for disposable sensors.

Effect of electrolytes concentration on recovery of cesium from AMP-PAN by Electrodialysis-Ion Exchange (EDIX)

International Nuclear Information System (INIS)

Mahendra, Ch.; Rajan, K.K.; SatyaSai, P.M.; Anand Babu, C.

2014-01-01

Cesium from the simulated acidic waste solution was separated using Ammonium Molybdophosphate (AMP) - Polyacrylonitrile (PAN) ion exchange resin in column operations. Electrodialysis - Ion exchange (EDIX) has been tried for the recovery of cesium from the AMP-PAN which was saturated with cesium. The electrodialysis setup consists of three compartments; cesium loaded AMP-PAN is placed in the middle compartment and is separated from the anode and cathode compartments by cation exchange membranes. Ammonium sulphate was used as anolyte and HNO 3 as catholyte. 0.1N HNO 3 was circulated in the middle compartment containing AMP-PAN to keep the resin in acidic form. On application of potential, the ammonium ions from the anode compartment migrate towards cathode through the middle compartment where they exchange with cesium ions on the resin and the exchanged cesium ions migrate towards cathode to get concentrated. Some part of cesium is recovered in the middle compartment due to convection. Cesium recovery from the AMP-PAN in the electrodialysis setup was studied at different anolyte and catholyte concentrations. All the experiments were carried out at constant current density of 40 mA/cm 2 for 15h. It was found that more than 50% of cesium recovery was observed for all the experiments studied and recovery percentage increased with increasing the anolyte concentration. It was observed that the electrolytes concentration affects the voltage drop across the cell

Sensing local pH and ion concentration at graphene electrode surfaces using in situ Raman spectroscopy.

Science.gov (United States)

Shi, Haotian; Poudel, Nirakar; Hou, Bingya; Shen, Lang; Chen, Jihan; Benderskii, Alexander V; Cronin, Stephen B

2018-02-01

We report a novel approach to probe the local ion concentration at graphene/water interfaces using in situ Raman spectroscopy. Here, the upshifts observed in the G band Raman mode under applied electrochemical potentials are used to determine the charge density in the graphene sheet. For voltages up to ±0.8 V vs. NHE, we observe substantial upshifts in the G band Raman mode by as much as 19 cm -1 , which corresponds to electron and hole carrier densities of 1.4 × 10 13 cm -2 and Fermi energy shifts of ±430 meV. The charge density in the graphene electrode is also measured independently using the capacitance-voltage characteristics (i.e., Q = CV), and is found to be consistent with those measured by Raman spectroscopy. From charge neutrality requirements, the ion concentration in solution per unit area must be equal and opposite to the charge density in the graphene electrode. Based on these charge densities, we estimate the local ion concentration as a function of electrochemical potential in both pure DI water and 1 M KCl solutions, which span a pH range from 3.8 to 10.4 for pure DI water and net ion concentrations of ±0.7 mol L -1 for KCl under these applied voltages.

Incineration of ion exchange resins using concentric burners

International Nuclear Information System (INIS)

Fukasawa, T.; Chino, K.; Kawamura, F.; Kuriyama, O.; Yusa, H.

1985-01-01

A new incineration method, using concentric burners, is studied to reduce the volume of spent ion exchange resins generated from nuclear power plants. Resins are ejected into the center of a propane-oxygen flame and burned within it. The flame length is theoretically evaluated by the diffusion-dominant model. By reforming the burner shape, flame length can be reduced by one-half. The decomposition ratio decreases with larger resin diameters due to the loss of unburned resin from the flame. A flame guide tube is adapted to increase resin holding time in the flame, which improves the decomposition ratio to over 98 wt%

Determination of molybdenum (VI) in sea water with preliminary concentration by the method of ion flotation

International Nuclear Information System (INIS)

Andreeva, I. Yu.; Drapchinskaya, O.L.; Lebedeva, L.I.

1985-01-01

The purpose of this paper is to assess the feasibility of using the method of ion flotation for the concentration of microamounts of molybdenum (VI) during determination in sea water. The ion flotation method is used for the purification of industrial sewage from the ions of nonferrous metals, including molybdenum (VI) with its content of up to 50 mg/liter. A 1.10 -4 M solution of sodium molybdate in 0.1M NaOH was used. The effect of different factors on the ion flotation process of molybdenum (VI) was investigated: pH of the solution, flotation times, concentrations of surface-active substances (SAS), molybdenum (IV), extraneous salts. Data presented show that the ion flotation method in conjunction with the photometric method of determining molybdenum with brompyrogallol red (BPR) and cetylpridinium chloride (CP) (limit of detection 0.02 micrograms/liter) allows the content of molybdenum (VI) in sea water to be established with sufficient reliability and reproducibility

Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

Institute of Scientific and Technical Information of China (English)

WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

2015-01-01

Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

Concentrations of ions in blood or athletes using NAA

International Nuclear Information System (INIS)

Kovacs, Luciana; Zamboni, Cibele B.; Loureno, Thiago F.; Nunes, Lazaro A.S.; Macedo, Denise V.

2011-01-01

Sodium (Na), chlorine (Cl) and potassium (K) are widely distributed in the body and are the mainly of body fluids electrolytes. K is the major intracellular ion. Na and Cl are the major extracellular ions. Therefore, Na and Cl can be regarded as the most important osmotically active electrolytes. The concentrations of these ions in body fluids are very tightly controlled. These electrolytes play central roles in electrolytic balances and current, in osmotic control, in the transport of organic metabolites by cells, and stabilization of poly electrolytes in cells. In this study Na, Cl and K levels were investigated in blood of athletes submitted to physical exercise at Laboratorio de Bioquimica do Exercicio (LABEX/UNICAMP - Brazil) using Neutron Activation Analyses (NAA) technique. The blood samples were collected from six male athletes, ranging from 18 to 26 years old, before and after the physical training. These results were compared with the rest condition (before start the physical exercise), as well as with the control group (subjects of same age but not involved with physical activities), for checking the performance of the athletes during and after the exercise. The nuclear procedure adopted as NAA, it can be an alternative procedure to perform biochemistry analyses in blood, mainly when the biological material is scarce. (author)

Paper-Based Analytical Device for Zinc Ion Quantification in Water Samples with Power-Free Analyte Concentration

Directory of Open Access Journals (Sweden)

Hiroko Kudo

2017-04-01

Full Text Available Insufficient sensitivity is a general issue of colorimetric paper-based analytical devices (PADs for trace analyte detection, such as metal ions, in environmental water. This paper demonstrates the colorimetric detection of zinc ions (Zn2+ on a paper-based analytical device with an integrated analyte concentration system. Concentration of Zn2+ ions from an enlarged sample volume (1 mL has been achieved with the aid of a colorimetric Zn2+ indicator (Zincon electrostatically immobilized onto a filter paper substrate in combination with highly water-absorbent materials. Analyte concentration as well as sample pretreatment, including pH adjustment and interferent masking, has been elaborated. The resulting device enables colorimetric quantification of Zn2+ in environmental water samples (tap water, river water from a single sample application. The achieved detection limit of 0.53 μM is a significant improvement over that of a commercial colorimetric Zn2+ test paper (9.7 μM, demonstrating the efficiency of the developed analyte concentration system not requiring any equipment.

Preferential solvation, ion pairing, and dynamics of concentrated aqueous solutions of divalent metal nitrate salts

Science.gov (United States)

Yadav, Sushma; Chandra, Amalendu

2017-12-01

We have investigated the characteristics of preferential solvation of ions, structure of solvation shells, ion pairing, and dynamics of aqueous solutions of divalent alkaline-earth metal nitrate salts at varying concentration by means of molecular dynamics simulations. Hydration shell structures and the extent of preferential solvation of the metal and nitrate ions in the solutions are investigated through calculations of radial distribution functions, tetrahedral ordering, and also spatial distribution functions. The Mg2+ ions are found to form solvent separated ion-pairs while the Ca2+ and Sr2+ ions form contact ion pairs with the nitrate ions. These findings are further corroborated by excess coordination numbers calculated through Kirkwood-Buff G factors for different ion-ion and ion-water pairs. The ion-pairing propensity is found to be in the order of Mg(NO3) 2 lead to the presence of substantial dynamical heterogeneity in these solutions of strongly interacting ions. The current study helps us to understand the molecular details of hydration structure, ion pairing, and dynamics of water in the solvation shells and also of ion diffusion in aqueous solutions of divalent metal nitrate salts.

Dynamics from seconds to hours in Hodgkin-Huxley model with time-dependent ion concentrations and buffer reservoirs.

Directory of Open Access Journals (Sweden)

Niklas Hübel

2014-12-01

Full Text Available The classical Hodgkin-Huxley (HH model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds, the buffer time constants (tens of seconds, and the slower backward buffering (minutes to hours. The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively.

Dynamics from seconds to hours in Hodgkin-Huxley model with time-dependent ion concentrations and buffer reservoirs.

Science.gov (United States)

Hübel, Niklas; Dahlem, Markus A

2014-12-01

The classical Hodgkin-Huxley (HH) model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds), the buffer time constants (tens of seconds), and the slower backward buffering (minutes to hours). The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively.

Evaluation of copper ion of antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori and optical, mechanical properties

Energy Technology Data Exchange (ETDEWEB)

Kim, Young-Hwan [School of Materials Science and Engineering, University of Yonsei, Seoul (Korea, Republic of); Choi, Yu-ri; Kim, Kwang-Mahn [Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, University of Yonsei, Seoul (Korea, Republic of); Choi, Se-Young, E-mail: sychoi@yonsei.ac.kr [School of Materials Science and Engineering, University of Yonsei, Seoul (Korea, Republic of)

2012-02-01

Antibacterial effect on Pseudomonas aeruginosa, Salmonella typhimurium and Helicobacter pylori of copper ion was researched. Also, additional effects of copper ion coating on optical and mechanical properties were researched as well. Copper ion was coated on glass substrate as a thin film to prevent bacteria from growing. Cupric nitrate was used as precursors for copper ion. The copper ion contained sol was deposited by spin coating process on glass substrate. Then, the deposited substrates were heat treated at the temperature range between 200 Degree-Sign C and 250 Degree-Sign C. The thickness of deposited copper layer on the surface was 63 nm. The antibacterial effect of copper ion coated glass on P. aeruginosa, S. typhimurium and H. pylori demonstrated excellent effect compared with parent glass. Copper ion contained layer on glass showed a similar value of transmittance compared with value of parent glass. The 3-point bending strength and Vickers hardness were 209.2 MPa, 540.9 kg/mm{sup 2} which were about 1.5% and 1.3% higher than the value of parent glass. From these findings, it is clear that copper ion coating on glass substrate showed outstanding effect not only in antibacterial activity but also in optical and mechanical properties as well.

A concentration-independent micro/nanofluidic active diode using an asymmetric ion concentration polarization layer.

Science.gov (United States)

Lee, Hyekyung; Kim, Junsuk; Kim, Hyeonsoo; Kim, Ho-Young; Lee, Hyomin; Kim, Sung Jae

2017-08-24

Over the past decade, nanofluidic diodes that rectify ionic currents (i.e. greater current in one direction than in the opposite direction) have drawn significant attention in biomolecular sensing, switching and energy harvesting devices. To obtain current rectification, conventional nanofluidic diodes have utilized complex nanoscale asymmetry such as nanochannel geometry, surface charge density, and reservoir concentration. Avoiding the use of sophisticated nano-asymmetry, micro/nanofluidic diodes using microscale asymmetry have been recently introduced; however, their diodic performance is still impeded by (i) low (even absent) rectification effects at physiological concentrations over 100 mM and strong dependency on the bulk concentration, and (ii) the fact that they possess only passive predefined rectification factors. Here, we demonstrated a new class of micro/nanofluidic diode with an ideal perm-selective nanoporous membrane based on ion concentration polarization (ICP) phenomenon. Thin side-microchannels installed near a nanojunction served as mitigators of the amplified electrokinetic flows generated by ICP and induced convective salt transfer to the nanoporous membrane, leading to actively controlled micro-scale asymmetry. Using this device, current rectifications were successfully demonstrated in a wide range of electrolytic concentrations (10 -5 M to 3 M) as a function of the fluidic resistance of the side-microchannels. Noteworthily, it was confirmed that the rectification factors were independent from the bulk concentration due to the ideal perm-selectivity. Moreover, the rectification of the presenting diode was actively controlled by adjusting the external convective flows, while that of the previous diode was passively determined by invariant nanoscale asymmetry.

Cupric ion reducing antioxidant capacity assay for antioxidants in human serum and for hydroxyl radical scavengers.

Science.gov (United States)

Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Bektaşoğlu, Burcu; Bener, Mustafa

2010-01-01

Tests measuring the combined antioxidant effect of the nonenzymatic defenses in biological fluids may be useful in providing an index of the organism's capability to counteract reactive species known as pro-oxidants, resist oxidative damage, and combat oxidative stress-related diseases. The selected chromogenic redox reagent for the assay of human serum should be easily accessible, stable, selective, and respond to all types of biologically important antioxidants such as ascorbic acid, alpha-tocopherol, beta-carotene, reduced glutathione (GSH), uric acid, and bilirubin, regardless of chemical type or hydrophilicity. Our recently developed cupric reducing antioxidant capacity (CUPRAC) spectrophotometric method for a number of polyphenols and flavonoids using the copper(II)-neocuproine reagent in ammonium acetate buffer is now applied to a complete series of plasma antioxidants for the assay of total antioxidant capacity of serum, and the resulting absorbance at 450 nm is recorded either directly (e.g., for ascorbic acid, alpha-tocopherol, and glutathione) or after incubation at 50 degrees C for 20 min (e.g., for uric acid, bilirubin, and albumin), quantitation being made by means of a calibration curve. The lipophilic antioxidants, alpha-tocopherol and beta-carotene, are assayed in dichloromethane. Lipophilic antioxidants of serum are extracted with n-hexane from an ethanolic solution of serum subjected to centrifugation. Hydrophilic antioxidants of serum are assayed in the centrifugate after perchloric acid precipitation of proteins. The CUPRAC molar absorptivities, linear ranges, and TEAC (trolox equivalent antioxidant capacity) coefficients of the serum antioxidants are established, and the results are evaluated in comparison with the findings of the ABTS/TEAC reference method. The intra- and inter-assay coefficients of variation (CVs) are 0.7 and 1.5%, respectively, for serum. The CUPRAC assay proved to be efficient for glutathione and thiol-type antioxidants

A Simplified Model to Estimate the Concentration of Inorganic Ions and Heavy Metals in Rivers

Directory of Open Access Journals (Sweden)

Clemêncio Nhantumbo

2016-10-01

Full Text Available This paper presents a model that uses only pH, alkalinity, and temperature to estimate the concentrations of major ions in rivers (Na+, K+, Mg2+, Ca2+, HCO3−, SO42−, Cl−, and NO3− together with the equilibrium concentrations of minor ions and heavy metals (Fe3+, Mn2+, Cd2+, Cu2+, Al3+, Pb2+, and Zn2+. Mining operations have been increasing, which has led to changes in the pollution loads to receiving water systems, meanwhile most developing countries cannot afford water quality monitoring. A possible solution is to implement less resource-demanding monitoring programs, supported by mathematical models that minimize the required sampling and analysis, while still being able to detect water quality changes, thereby allowing implementation of measures to protect the water resources. The present model was developed using existing theories for: (i carbonate equilibrium; (ii total alkalinity; (iii statistics of major ions; (iv solubility of minerals; and (v conductivity of salts in water. The model includes two options to estimate the concentrations of major ions: (1 a generalized method, which employs standard values from a world-wide data base; and (2 a customized method, which requires specific baseline data for the river of interest. The model was tested using data from four monitoring stations in Swedish rivers with satisfactory results.

Capacitance of Nanoporous Carbon-Based Supercapacitors Is a Trade-Off between the Concentration and the Separability of the Ions.

Science.gov (United States)

Burt, Ryan; Breitsprecher, Konrad; Daffos, Barbara; Taberna, Pierre-Louis; Simon, Patrice; Birkett, Greg; Zhao, X S; Holm, Christian; Salanne, Mathieu

2016-10-06

Nanoporous carbon-based supercapacitors store electricity through adsorption of ions from the electrolyte at the surface of the electrodes. Room temperature ionic liquids, which show the largest ion concentrations among organic liquid electrolytes, should in principle yield larger capacitances. Here, we show by using electrochemical measurements that the capacitance is not significantly affected when switching from a pure ionic liquid to a conventional organic electrolyte using the same ionic species. By performing additional molecular dynamics simulations, we interpret this result as an increasing difficulty of separating ions of opposite charges when they are more concentrated, that is, in the absence of a solvent that screens the Coulombic interactions. The charging mechanism consistently changes with ion concentration, switching from counterion adsorption in the diluted organic electrolyte to ion exchange in the pure ionic liquid. Contrarily to the capacitance, in-pore diffusion coefficients largely depend on the composition, with a noticeable slowing of the dynamics in the pure ionic liquid.

Effect of europium ion concentration on the structural and photoluminescence properties of novel Li2BaZrO4: Eu3+ nanocrystals

Science.gov (United States)

Ahemen, I.; Dejene, F. B.; Kroon, R. E.; Swart, H. C.

2017-12-01

This work reports the influence of Eu3+ ion concentration on the structure and photoluminescence properties of Li2BaZrO4 nanocrystals including its intrinsic quantum efficiency (IQE). Chemical bath method was employed in the synthesis procedure. X-ray diffraction results showed tetragonal phase for Eu3+ ion concentration in the range 1 and 7 mol% and cubic phase at 8 mol%. The presence of barium oxide (BaO) was confirmed from selected area electron diffraction (SAED). The excitation spectra for these phosphors consisted of broad charge transfer (CT) bands due to the combination of Zr4+ - O2- and Eu3+-O2- charge transfer states. Superimposed on the CT band were direct excitation levels of Eu3+ and Ba2+ ions, in the range 320-450 nm. At high Eu3+ ions concentrations, the intensities of CT bands decreased because some of the ions were coordinated with Ba2+ ions. Photoluminescence emissions for all the doped samples at room temperature appeared to be entirely from intraconfigurational Eu3+ emissions and depended both on the site symmetry as well as the ion concentration. The quadrupole-quadrupole multipolar process was found to be solely responsible for the luminescence quenching. The intensity parameters (Ω2 ,Ω4), asymmetry ratio, R0 and the average decay lifetime of the nanocrystals showed dependence on concentration. High internal quantum efficiency (IQE) values were obtained at low Eu3+ ion concentrations, but efficiency decreased with increasing ion concentration. The CIE coordinates values were comparable to existing red phosphors and in combination with the high IQE make this phosphor a good candidate for red light emitting applications.

Electrochemical activation and inhibition of neuromuscular systems through modulation of ion concentrations with ion-selective membranes

Science.gov (United States)

Song, Yong-Ak; Melik, Rohat; Rabie, Amr N.; Ibrahim, Ahmed M. S.; Moses, David; Tan, Ara; Han, Jongyoon; Lin, Samuel J.

2011-12-01

Conventional functional electrical stimulation aims to restore functional motor activity of patients with disabilities resulting from spinal cord injury or neurological disorders. However, intervention with functional electrical stimulation in neurological diseases lacks an effective implantable method that suppresses unwanted nerve signals. We have developed an electrochemical method to activate and inhibit a nerve by electrically modulating ion concentrations in situ along the nerve. Using ion-selective membranes to achieve different excitability states of the nerve, we observe either a reduction of the electrical threshold for stimulation by up to approximately 40%, or voluntary, reversible inhibition of nerve signal propagation. This low-threshold electrochemical stimulation method is applicable in current implantable neuroprosthetic devices, whereas the on-demand nerve-blocking mechanism could offer effective clinical intervention in disease states caused by uncontrolled nerve activation, such as epilepsy and chronic pain syndromes.

A procedure for reducing the concentration of hydrogen ions in acid anionic eluate and equipment therefore

International Nuclear Information System (INIS)

Parobek, P.; Baloun, S.; Plevac, S.

1989-01-01

The method is described of reducing the concentration of hydrogen ions in acid anionic eluate produced in the separation of uranium or other metals, in which anion exchanger elution, precipitation, filtration and precipitate and anion exchanger washing are used. The technological line for such elution comprises at least one ion exchange column and at least one container. They together form the first and the second stages of preparation of the acid anion elution solution, the sorption-elution separation of hydrogen ions on an cation exchanger being inserted between them. The preparation of the solution is divide into two stages. In the first stage, the acid and part of the solution for the preparation of the acid anion elution solution are supplied. The resulting enriched acid elution solution is fe onto the cation exchanger where the hydrogen ion concentration i reduced. It is then carried into the second stage where it is mixed with the remaining part of the solution. (B.S.)

Seasonal dynamics of nitrate and ammonium ion concentrations in soil solutions collected using MacroRhizon suction cups.

Science.gov (United States)

Kabala, Cezary; Karczewska, Anna; Gałka, Bernard; Cuske, Mateusz; Sowiński, Józef

2017-07-01

The aims of the study were to analyse the concentration of nitrate and ammonium ions in soil solutions obtained using MacroRhizon miniaturized composite suction cups under field conditions and to determine potential nitrogen leaching from soil fertilized with three types of fertilizers (standard urea, slow-release urea, and ammonium nitrate) at the doses of 90 and 180 kg ha -1 , applied once or divided into two rates. During a 3-year growing experiment with sugar sorghum, the concentration of nitrate and ammonium ions in soil solutions was the highest with standard urea fertilization and the lowest in variants fertilized with slow-release urea for most of the months of the growing season. Higher concentrations of both nitrogen forms were noted at the fertilizer dose of 180 kg ha -1 . One-time fertilization, at both doses, resulted in higher nitrate concentrations in June and July, while dividing the dose into two rates resulted in higher nitrate concentrations between August and November. The highest potential for nitrate leaching during the growing season was in July. The tests confirmed that the miniaturized suction cups MacroRhizon are highly useful for routine monitoring the concentration of nitrate and ammonium ions in soil solutions under field conditions.

Inhibition of cellulase-catalyzed lignocellulosic hydrolysis by iron and oxidative metal ions and complexes.

Science.gov (United States)

Tejirian, Ani; Xu, Feng

2010-12-01

Enzymatic lignocellulose hydrolysis plays a key role in microbially driven carbon cycling and energy conversion and holds promise for bio-based energy and chemical industries. Cellulases (key lignocellulose-active enzymes) are prone to interference from various noncellulosic substances (e.g., metal ions). During natural cellulolysis, these substances may arise from other microbial activities or abiotic events, and during industrial cellulolysis, they may be derived from biomass feedstocks or upstream treatments. Knowledge about cellulolysis-inhibiting reactions is of importance for the microbiology of natural biomass degradation and the development of biomass conversion technology. Different metal ions, including those native to microbial activity or employed for biomass pretreatments, are often tested for enzymatic cellulolysis. Only a few metal ions act as inhibitors of cellulases, which include ferrous and ferric ions as well as cupric ion. In this study, we showed inhibition by ferrous/ferric ions as part of a more general effect from oxidative (or redox-active) metal ions and their complexes. The correlation between inhibition and oxidation potential indicated the oxidative nature of the inhibition, and the dependence on air established the catalytic role that iron ions played in mediating the dioxygen inhibition of cellulolysis. Individual cellulases showed different susceptibilities to inhibition. It is likely that the inhibition exerted its effect more on cellulose than on cellulase. Strong iron ion chelators and polyethylene glycols could mitigate the inhibition. Potential microbiological and industrial implications of the observed effect of redox-active metal ions on enzymatic cellulolysis, as well as the prevention and mitigation of this effect in industrial biomass conversion, are discussed.

Structural and Dynamical Properties of Alkaline Earth Metal Halides in Supercritical Water: Effect of Ion Size and Concentration.

Science.gov (United States)

Keshri, Sonanki; Tembe, B L

2017-11-22

Constant temperature-constant pressure molecular dynamics simulations have been performed for aqueous alkaline earth metal chloride [M 2+ -Cl - (M = Mg, Ca, Sr, and Ba)] solutions over a wide range of concentrations (0.27-5.55 m) in supercritical (SC) and ambient conditions to investigate their structural and dynamical properties. A strong influence of the salt concentration is observed on the ion-ion pair correlation functions in both ambient and SC conditions. In SC conditions, significant clustering is observed in the 0.27 m solution, whereas the reverse situation is observed at room temperature and this is also supported by the residence times of the clusters. The concentration and ion size (cation size) seem to have opposite effects on the average number of hydrogen bonds. The simulation results show that the self-diffusion coefficients of water, cations, and the chloride ion increase with increasing temperature, whereas they decrease with increasing salt concentration. The cluster size distribution shows a strong density dependence in both ambient and SC conditions. In SC conditions, cluster sizes display a near-Gaussian distribution, whereas the distribution decays monotonically in ambient conditions.

Effect of metal ion concentration on the biosorption of Pb2+ and ...

African Journals Online (AJOL)

The influence of initial metal ion concentration of the batch sorption of Pb2+ and Cd2+ onto a low-cost biosorbent was investigated. The experimental results were analysed in terms of Langmuir and Freundlich isotherms. According to the evaluation using Langmuir equation, the monolayer sorption capacity obtained were ...

Concentration of ions in selected bottled water samples sold in Malaysia

Science.gov (United States)

Aris, Ahmad Zaharin; Kam, Ryan Chuan Yang; Lim, Ai Phing; Praveena, Sarva Mangala

2013-03-01

Many consumers around the world, including Malaysians, have turned to bottled water as their main source of drinking water. The aim of this study is to determine the physical and chemical properties of bottled water samples sold in Selangor, Malaysia. A total of 20 bottled water brands consisting of `natural mineral (NM)' and `packaged drinking (PD)' types were randomly collected and analyzed for their physical-chemical characteristics: hydrogen ion concentration (pH), electrical conductivity (EC) and total dissolved solids (TDS), selected major ions: calcium (Ca), potassium (K), magnesium (Mg) and sodium (Na), and minor trace constituents: copper (Cu) and zinc (Zn) to ascertain their suitability for human consumption. The results obtained were compared with guideline values recommended by World Health Organization (WHO) and Malaysian Ministry of Health (MMOH), respectively. It was found that all bottled water samples were in accordance with the guidelines set by WHO and MMOH except for one sample (D3) which was below the pH limit of 6.5. Both NM and PD bottled water were dominated by Na + K > Ca > Mg. Low values for EC and TDS in the bottled water samples showed that water was deficient in essential elements, likely an indication that these were removed by water treatment. Minerals like major ions were present in very low concentrations which could pose a risk to individuals who consume this water on a regular basis. Generally, the overall quality of the supplied bottled water was in accordance to standards and guidelines set by WHO and MMOH and safe for consumption.

A synthetic ion transporter that disrupts autophagy and induces apoptosis by perturbing cellular chloride concentrations

Science.gov (United States)

Busschaert, Nathalie; Park, Seong-Hyun; Baek, Kyung-Hwa; Choi, Yoon Pyo; Park, Jinhong; Howe, Ethan N. W.; Hiscock, Jennifer R.; Karagiannidis, Louise E.; Marques, Igor; Félix, Vítor; Namkung, Wan; Sessler, Jonathan L.; Gale, Philip A.; Shin, Injae

2017-07-01

Perturbations in cellular chloride concentrations can affect cellular pH and autophagy and lead to the onset of apoptosis. With this in mind, synthetic ion transporters have been used to disturb cellular ion homeostasis and thereby induce cell death; however, it is not clear whether synthetic ion transporters can also be used to disrupt autophagy. Here, we show that squaramide-based ion transporters enhance the transport of chloride anions in liposomal models and promote sodium chloride influx into the cytosol. Liposomal and cellular transport activity of the squaramides is shown to correlate with cell death activity, which is attributed to caspase-dependent apoptosis. One ion transporter was also shown to cause additional changes in lysosomal pH, which leads to impairment of lysosomal enzyme activity and disruption of autophagic processes. This disruption is independent of the initiation of apoptosis by the ion transporter. This study provides the first experimental evidence that synthetic ion transporters can disrupt both autophagy and induce apoptosis.

Sorption properties of algae Spirogyra sp. and their use for determination of heavy metal ions concentrations in surface water.

Science.gov (United States)

Rajfur, Małgorzata; Kłos, Andrzej; Wacławek, Maria

2010-11-01

Kinetics of heavy-metal ions sorption by alga Spirogyra sp. was evaluated experimentally in the laboratory, using both the static and the dynamic approach. The metal ions--Mn(2+), Cu(2+), Zn(2+) and Cd(2+)--were sorbed from aqueous solutions of their salts. The static experiments showed that the sorption equilibria were attained in 30 min, with 90-95% of metal ions sorbed in first 10 min of each process. The sorption equilibria were approximated with the Langmuir isotherm model. The algae sorbed each heavy metal ions proportionally to the amount of this metal ions in solution. The experiments confirmed that after 30 min of exposition to contaminated water, the concentration of heavy metal ions in the algae, which initially contained small amounts of these metal ions, increased proportionally to the concentration of metal ions in solution. The presented results can be used for elaboration of a method for classification of surface waters that complies with the legal regulations. Copyright © 2010 Elsevier B.V. All rights reserved.

Integrated pretreatment and desalination by electrocoagulation (EC)-ion concentration polarization (ICP) hybrid.

Science.gov (United States)

Choi, Siwon; Kim, Bumjoo; Han, Jongyoon

2017-06-13

Conventional water treatment process is composed of multiple stages, including desalination (salt removal) and pre/post-treatment of desalination to remove particles, chemicals, and other potential foulants for desalination. In this work, we developed a microfluidic proof-of-concept for a single device water treatment system, which removes both salt ions and non-salt contaminants. Our system combines electrocoagulation (EC), a versatile contaminant removal process, and ion concentration polarization (ICP) desalination, which is an electromembrane desalination process. We demonstrated a continuous EC-ICP operation that removed >95% of suspended solids and reduced the salinity from brackish range (20 mM NaCl) to a potable level (<8.6 mM NaCl). We also demonstrated that our system is flexible in terms of the type and concentration of contaminants it can handle. Combining two different electrochemical processes into a single system, we can reduce unnecessary voltage drop by having a shared anode, and achieve both seamless integration and energy efficient operation. Our system will find applications as a small-scale water treatment system, if properly scaled up in the future.

Concentration effect on the spectroscopic behavior of Tb{sup 3+} ions in zinc phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Kesavulu, C.R., E-mail: crkesavulu2005@gmail.com [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil); Almeida Silva, Anielle Christine [Laboratorio de Novos Materials Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberândia, MG (Brazil); Dousti, M.R. [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil); Dantas, Noelio Oliveira [Laboratorio de Novos Materials Isolantes e Semicondutores (LNMIS), Instituto de Física, Universidade Federal de Uberândia, MG (Brazil); Camargo, A.S.S. de; Catunda, Tomaz [Instituto de Fisica de São Carlos, Universidade de São Paulo, Avenida Trabalhador Sãocarlense 400, São Carlos, SP (Brazil)

2015-09-15

Zinc phosphate glasses (PZABPTb) in the compositional system: P{sub 2}O{sub 5}–ZnO–Al{sub 2}O{sub 3}–BaO–PbO doped with variable Tb{sup 3+} concentrations (1–5 wt% Tb{sub 2}O{sub 3}) were prepared and characterized through absorption, excitation, emission and intensity decay rate measurements. The Judd–Ofelt model has been adopted to evaluate the radiative properties of the {sup 5}D{sub 4}→{sup 7}F{sub 6–3} emission transitions. The effect of Tb{sup 3+} ion concentration on the emissions from the {sup 5}D{sub 3,4} excited levels is discussed in detail. Analysis of the intensity decay curves corresponding to blue and green emissions from levels {sup 5}D{sub 3} and {sup 5}D{sub 4}, respectively, allowed determination of effective lifetimes, which confirmed the Tb{sup 3+} ion concentration quenching of the blue emission in these glasses. The decay curves for the {sup 5}D{sub 3} level are found to be non-exponential in nature for all the studied concentrations due to ion–ion energy transfer through cross-relaxation. In an attempt to identify the origin of the energy transfer mechanism, the decay curves were well fitted to the Inokuti–Hirayama model for S=6, which indicates that the energy transfer process is of dipole–dipole type. The optical band gap energy (E{sub opt}) has been evaluated taking into account the ultraviolet edge of absorption spectra. - Highlights: • Tb{sup 3+}-doped zinc phosphate glasses have been prepared by melt quenching technique. • Spectroscopic parameters were evaluated using the Judd–Ofelt theory. • Effects of Tb{sup 3+} concentration on luminescence of the glasses were studied. • Strong intense laser transition for Tb{sup 3+} ion in PZABPTb glasses is {sup 5}D{sub 4}→{sup 7}F{sub 5} (0.54 μm). • PZABPTb glasses could be used in the development of green color display devices and solid state visible lasers.

Responses of microalgae Coelastrella sp. to stress of cupric ions in treatment of anaerobically digested swine wastewater.

Science.gov (United States)

Li, Xiang; Yang, William L; He, Huijun; Wu, Shaohua; Zhou, Qi; Yang, Chunping; Zeng, Guangming; Luo, Le; Lou, Wei

2018-03-01

Microalgae Coelastrella sp. could remove nutrients from anaerobically digested swine wastewater (ADSW) effectively, while its responses to the stress of Cu(II) were not well understood. In this paper, nutrients removal and growth of Coelastrella sp. were investigated at the presence of Cu(II) in ADSW. Results showed ammonium nitrogen concentration in ADSW decreased with culturing duration, while increased with an increased Cu(II) concentration. Total phosphorous concentration decreased with time, while did not drop in 4 days at Cu(II) concentration ≥1.0 mg/L. Microalgal growth was inhibited at all the Cu(II) concentrations, and ceased in about 6-8 days at Cu(II) concentration ≥1.0 mg/L. With an increased Cu(II) concentration, the contents of chlorophyll a and proteins decreased, those of malondialdehyde and superoxide dismutase, and ratios of octadecanoic acid (C18:0), hexadecanoic acid (C16:0) and octadecenoic acid (C18:1) to fatty acids in Coelastrella sp. increased, while octadecatrienoic acid (C18:3) gradually disappeared. Copyright © 2017 Elsevier Ltd. All rights reserved.

Speciation of Am(III)/Eu(III) sorbed on γ-alumina. Effect of metal ion concentration

International Nuclear Information System (INIS)

Kumar, S.; Tomar, B.S.; Godbole, S.V.

2013-01-01

The present paper describes the speciation of Am(III)/Eu(III) sorbed on γ-alumina, and its evolution with changing metal ion concentration, studied using batch sorption experiment, time resolved fluorescence spectroscopy (TRFS), extended X-ray absorption fine structure (EXAFS) and surface Complexation modeling (SCM). Though numerous studies exist in the literature on the speciation of trivalent actinides and lanthanides on alumina surface, the mechanism of sorption at high metal ion concentrations is not yet fully understood. Batch sorption experiments of Am(III) on γ-alumina under varying condition of pH (3-10), ionic strength (0.005-0.1 M NaClO 4 ) and metal ion concentration (10 -7 -10 -4 M) were performed. Higher metal ion concentration was achieved by the addition of Eu(III) considering it as an analogue of Am(III). Time resolved fluorescence spectroscopy (TRFS) study of Eu(III) sorbed on γ-alumina at the metal ion concentration of 5.0 x 10 -5 M was carried out over pH 4 to 7. TRFS showed the presence of two surface species, with distinctly different fluorescence decay life times. The shorter lifetime value and its changing pattern with pH indicate the surface species corresponding to this component to be monodentate species > AlOAm 2+ and its hydrolyzed forms. The sorbed Eu 3+ species corresponding to the longer lifetime value has 2-3 water molecules in its first coordination sphere and is multidentate in its binding on alumina surface. Extended X-ray absorption fine structure (EXAFS) measurement of Eu:γ-Al 2 O 3 sorption systems at pH 6.18 and 7.15 corroborate the existence of two surface complexes. Further it suggests the edge sharing bidentate binding of Eu on AlO 6 octahedra as the co-ordination mode of the higher lifetime component. Surface Complexation Modeling (SCM) of Am(III)/Eu(III) sorption onto γ-alumina at pH ≤7 has been carried out using these two surface species. 2-pK surface complexation modeling coupled with constant capacitance model

[Effect of high magnesium ion concentration on the electron transport rate and proton exchange in thylakoid membranes in higher plants].

Science.gov (United States)

Ignat'ev, A R; Khorobrykh, S A; Ivanov, B N

2001-01-01

The effects of magnesium ion concentration on the rate of electron transport in isolated pea thylakoids were investigated in the pH range from 4.0 up to 8.0. In the absence of magnesium ions in the medium and in the presence of 5 mM MgCl2 in the experiments not only without added artificial acceptors but also with ferricyanide or methylviologen as an acceptor, this rate had a well-expressed maximum at pH 5.0. It was shown that, after depression to minimal values at pH 5.5-6.5, it gradually rose with increasing pH. An increase in magnesium ion concentration up to 20 mM essentially affected the electron transfer rate: it decreased somewhat at pH 4.0-5.0 but increased at higher pH values. At this magnesium ion concentration, the maximum rate was at pH 6.0-6.5 and the minimum, at pH 7.0. Subsequent rise upon increasing pH to 8.0 was expressed more sharply. The influence of high magnesium ion concentration on the rate of electron transport was not observed in the presence of gramicidin D. It was found that without uncoupler, the changes in the electron transfer rate under the influence of magnesium ions correlated to the changes in the first-order rate constant of the proton efflux from thylakoids. It is supposed that the change in the ability of thylakoids to keep protons by the action of magnesium ions is the result of electrostatic interactions of these ions with the charges on the external surface of membranes. A possible role of regulation of the electron transport rate by magnesium ions in vivo is discussed.

Influence of zirconium ion concentration in model extraction systems TBP - diluents - Zr+4 - nitric acid

International Nuclear Information System (INIS)

Rogoz, F.; Tlalka, M.

1987-07-01

In systems containing TBP, MBP, DBP and 1-butanol stable emulsions and precipitates are formed which separation is difficult in certain domain of concentration in zirconium ions. MPB and DBP increase stability of primary emulsion in kerosen and carbon tetrachloride but for different concentrations of nitric acid. Addition of 1-butanol decreases slightly the stability of primary emulsion [fr

{mu}PIXE for a {mu}Brain: The vinegar fly's brain, antenna, sensilla hairs and eye ion concentrations

Energy Technology Data Exchange (ETDEWEB)

Reinert, Anja, E-mail: areinert@ice.mpg.de [Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Strasse 8, 07745 Jena (Germany); Barapatre, Nirav [Institute for Experimental Physics II, University of Leipzig, Linnestrasse 5, 04103 Leipzig (Germany); Sachse, Silke [Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Hans-Knoell-Strasse 8, 07745 Jena (Germany); Reinert, Tilo [Department of Physics, University of North Texas, 1155 Union Circle, 76203 Denton, TX (United States)

2011-10-15

The vinegar fly Drosophila melanogaster is used as model organism to study a variety of different scientific purposes. Thus, our laboratory studies the olfactory system by neurobiological experiments. These techniques are often disruptive and need to compensate or exchange the body fluid, the lymph, with an artificial Ringer's solution in defined compartments of the fly. The solution mainly contains Na, Cl, K and Ca and is to keep physiological conditions. Therefore, the knowledge about the ion concentrations in the respective Drosophila lymph is required for a correct mixture of the ions. This paper presents the spatially resolved concentrations of P, S, Cl, K, Ca, Fe, Cu and Zn in lyophilised head cryosections of Drosophila by using quantitative {mu}PIXE at the ion beam facility LIPSION in Leipzig. The PIXE maps enable a detailed analysis of particular regions of interest down to a spatial resolution of 0.5 {mu}m. We quantified the ion concentrations especially in the brain, the antenna and its sensilla hairs acting as the olfactory organ of the fly, in the compound eye and in the mouthparts. The averaged element concentrations of these main compartments are (in descending order): P: 90 mM, K: 81 mM, S: 38 mM, Cl: 18 mM, Ca: 4.9 mM, Fe: 1.4 mM, Zn: 1.2 mM, Cu: 0.06 mM. Certain structures or cavities possess a remarkably high concentration of particular elements and might reflect the different functions of the compartments. An example presented in more detail is the composition of the compound eye. Conclusively, our findings on the ion concentrations might be useful for the mixture of the Drosophila Ringer's solution to ensure physiological conditions in experiments.

Activation of persulfate/copper by hydroxylamine via accelerating the cupric/cuprous redox couple.

Science.gov (United States)

Zhou, Peng; Zhang, Jing; Liang, Juan; Zhang, Yongli; Liu, Ya; Liu, Bei

2016-01-01

Cuprous copper [Cu(I)] reacts with sodium persulfate (PDS) to generate sulfate radical SO4(-)•, but it has been seldom investigated owing to its instability and difficulty in dissolving it. This study proposes a new method to regenerate Cu(I) from cupric copper [Cu(II)] by addition of hydroxylamine (HA) to induce the continuous production of radicals through active PDS, and investigates the resulting enhanced methyl orange (MO) degradation efficiency and mechanism in the new system. HA accelerated the degradation of MO markedly in the pH range from 6.0 to 8.0 in the HA/Cu(II)/PDS process. Both SO4(-)• and hydroxyl radicals (•OH) were considered as the primary reactive radicals in the process. The MO degradation in the HA/Cu(II)/PDS process can be divided into three stages: the fast stage, the transitory stage, and the low stage. MO degradation was enhanced with increased dosage of PDS. Although high dosage of HA could accelerate the transformation of the Cu(II)/Cu(I) cycle to produce more reactive radicals, excess HA can quench the reactive radicals. This study indicates that through a copper-redox cycling mechanism by HA, the production of SO4(-)• and •OH can be strongly enhanced, and the effective pH range can be expanded to neutral conditions.

Quantitative Visualization of Salt Concentration Distributions in Lithium-Ion Battery Electrolytes during Battery Operation Using X-ray Phase Imaging.

Science.gov (United States)

Takamatsu, Daiko; Yoneyama, Akio; Asari, Yusuke; Hirano, Tatsumi

2018-02-07

A fundamental understanding of concentrations of salts in lithium-ion battery electrolytes during battery operation is important for optimal operation and design of lithium-ion batteries. However, there are few techniques that can be used to quantitatively characterize salt concentration distributions in the electrolytes during battery operation. In this paper, we demonstrate that in operando X-ray phase imaging can quantitatively visualize the salt concentration distributions that arise in electrolytes during battery operation. From quantitative evaluation of the concentration distributions at steady states, we obtained the salt diffusivities in electrolytes with different initial salt concentrations. Because of no restriction on samples and high temporal and spatial resolutions, X-ray phase imaging will be a versatile technique for evaluating electrolytes, both aqueous and nonaqueous, of many electrochemical systems.

Metal ion concentrations in body fluids after implantation of hip replacements with metal-on-metal bearing--systematic review of clinical and epidemiological studies.

Directory of Open Access Journals (Sweden)

Albrecht Hartmann

Full Text Available INTRODUCTION: The use of metal-on-metal (MoM total hip arthroplasty (THA increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. OBJECTIVE: To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. METHODS: Systematic review of clinical trials (RCTs and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor, patient characteristics as well as study quality characteristics (secondary explanatory factors. RESULTS: Overall, 104 studies (11 RCTs, 93 epidemiological studies totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L. Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. DISCUSSION: Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed "time out" for stemmed large-head MoM-THA and recommend a restricted

The Gellyfish: an in-situ equilibrium-based sampler for determining multiple free metal ion concentrations in marine ecosystems

Science.gov (United States)

Free metal ions are usually the most bioavailable and toxic metal species to aquatic organisms, but they are difficult to measure because of their extremely low concentrations in the marine environment. Many of the current methods for determining free metal ions are complicated a...

Analysis of movements of both specific activity of tritium and concentration of each ion in short-term precipitation at typhoons

International Nuclear Information System (INIS)

Yamada, Ryuta; Watanabe, Minami; Ying, Wang; Kataoka, Noriaki; Morita, Syogo; Imaizumi, Hiroshi; Kano, Naoki

2015-01-01

Both the specific activity of tritium and the concentration of several ions(Na + , K + , Mg 2+ , Ca 2+ , Cl - , NO 3 - , SO 4 2- ) in precipitation at typhoons in Niigata city, Japan were measured, and the following matters were found as to precipitation at typhoon. (1) Specific activities of tritium at typhoons were under the average of the activities in precipitation in the same month. (2) The specific activity of tritium depends on that whether the precipitation was sampled after the several days from the last rain, or not so long. (3) Movements of these ion concentrations in precipitation are similar to each other except nitrate ion. (4) Each ion concentration ratio in precipitation at a typhoon became to be similar to that in sea with time. (5) Using relative compositional ratio of sampled water to sea water defined in this research, the effect of sea water on precipitation can be revealed. (author)

Isolation of transplutonium elements on ion exchangers from solutions of high salt concentration

International Nuclear Information System (INIS)

Guseva, L.I.; Tikhomirova, G.S.; Stepushkina, V.V.

1985-01-01

The behaviour of transplutonium elements (TPE) on cation and anion exchangers in aqueous alcoholic solutions of chlorides and nitrates of some alkali and alkaline earth metals depending on different factors: salt concentration, content of alcohol and of acid in the solution as well as the nature of a cation was studied. The data obtained were used to determine the optimal conditions of concentration of TPE on ion exchangers from solutions containing great quantities of salts. The advantages of the use of aqueous alcoholic solutions of nitric acid in the isolation of TPE are shown. (author)

Selectivity improvement of positive photoionization ion mobility spectrometry for rapid detection of organophosphorus pesticides by switching dopant concentration.

Science.gov (United States)

Zhou, Qinghua; Li, Jia; Wang, Bin; Wang, Shuang; Li, Haiyang; Chen, Jinyuan

2018-01-01

Ion mobility spectrometry (IMS) opened a potential avenue for the rapid detection of organophosphorus pesticides (OPPs), though an improved selectivity of stand-alone IMS was still in high demand. In this study, a stand-alone positive photoionization ion mobility spectrometry (PP-IMS) apparatus was constructed for the rapid detection of OPPs with acetone as dopant. The photoionization of acetone molecules was induced by the ultraviolet irradiation to produce the reactant ions (Ac) 2 H + , which were employed to ionize the OPPs including fenthion, imidan, phosphamidon, dursban, dimethoate and isocarbophos via the proton transfer reaction. Due to the difference in proton affinity, the tested OPPs exhibited the different dopant-dependent manners. Based on this observation, the switching of dopant concentration was implemented to improve the selectivity of PP-IMS for OPPs detection. For instance, a mixture of fenthion, dursban and dimethoate was tested. By switching the concentration of doped acetone from 0.07 to 2.33 to 19.94mgL -1 , the ion peaks of fenthion and dursban were inhibited in succession, achieving the selective detection of dimethoate at last. In addition, another mixture of imidan and phosphamidon was initially detected by PP-IMS with a dose of 0.07mgL -1 acetone, indicating that their ion peaks were severely overlapped; when the concentration of doped acetone was switched to 19.94mgL -1 , the inhibition of imidan signals promised the accurate identification of phosphamidon in mixture. Finally, the PP-IMS in combination of switching dopant concentration was applied to detect the mixed fenthion, dursban and dimethoate in Chinese cabbage, demonstrating the applicability of proposed method to real samples. Copyright © 2017. Published by Elsevier B.V.

The hemodynamic effect of calcium ion concentration in the infusate during predilution hemofiltration in chronic renal failure

DEFF Research Database (Denmark)

Karamperis, N.; Sloth, E.; Jensen, Jens Dam

2005-01-01

BACKGROUND: It is the prevailing view that convective dialysis techniques stabilize blood pressure. Calcium concentration in the substitution fluid may be important in this respect. The aim of this study is to investigate the influence of calcium ion concentration in the substitution fluid on hem...

Evolution of ion damage at 773K in Ni- containing concentrated solid-solution alloys

Science.gov (United States)

Shi, Shi; He, Mo-Rigen; Jin, Ke; Bei, Hongbin; Robertson, Ian M.

2018-04-01

Quantitative analysis of the impact of the compositional complexity in a series of Ni-containing concentrated solid-solution alloys, Ni, NiCo, NiFe, NiCoCr, NiCoFeCr, NiCoFeCrMn and NiCoFeCrPd, on the evolution of defects produced by 1 MeV Kr ion irradiation at 773 K is reported. The dynamics of the evolution of the damage structure during irradiation to a dose of 2 displacements per atom were observed directly by performing the ion irradiations in electron transparent foils in a transmission electron microscope coupled to an ion accelerator. The defect evolution was assessed through measurement of the defect density, defect size and fraction of perfect and Frank loops. These three parameters were dependent on the alloying element as well as the number of elements. The population of loops was sensitive to the ion dose and alloy composition as faulted Frank loops were observed to unfault to perfect loops with increasing ion dose. These dependences are explained in terms of the influence of each element on the lifetime of the displacement cascade as well as on defect formation and migration energies.

Structure-volume relationships: singular volume effects produced by cupric ion-globular protein interaction.

Science.gov (United States)

Katz, S; Shinaberry, G; Heck, E L; Squire, W

1980-08-05

The nature of the volume isotherms produced by the coordination of Cu(II) with ovalbumin and bovine serum albumin differs substantially from the adsorption isotherms produced by these systems. Whereas there was increased binding of Cu(II) associated with a pH increase from pH 5.3 to pH 7.4, the volume isotherms for these systems did not exhibit this type of pH dependence. The volume changes were determined at 30.0 +/- 0.001 degrees C with microdilatometers which could be read to 0.01 muL. The binding isotherms for ovalbumin at pH 5.3 and 7.4 and for bovine serum albumin at pH 5.3 was resolved by a Scatchard plot to yield the appropriate thermodynamic parameters. An algorithm was derived to calculate the distribution of the individual PMi complexes, i.e., PMi-1 + M in equilibrium (Ki) PMi where i equals 1, 2, 3, ..., n moles of cation, M, bound per mole of protein, P, for the above systems. The volume isotherms were then resolved in terms of the constituent delta Vi terms, i.e., the volume change produced by the formation of the individual PMi complexes. These values were verified by an independent graphical differentiation procedure. The coordination of Cu(II) to BSA at pH 7.4 produced a cooperative adsorption isotherm which was not amenable to a Scatchard analysis. The resultant anomalous volume isotherm was resolved into a component related to Cu(II)-site interaction and a negative volume effect attributable to a conformational change induced by complex formation. This structural transition which occurs at physiological pH may constitute a control mechanism for regulating the serum level of Cu(II) and possibly other divalent ions.

Water-soluble metal-binding polymers with ultrafiltration: A technology for the removal, concentration, and recovery of metal ions from aqueous streams

International Nuclear Information System (INIS)

Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

1997-01-01

The use of water-soluble metal-binding polymers coupled with ultrafiltration (UF) is a technology under development to selectively concentrate and recover valuable or regulated metal-ions from dilute process or waste waters. The polymers have a sufficiently large molecular size that they can be separated and concentrated using commercially available UF technology. The polymers can then be reused by changing the solution conditions to release the metal-ions, which are recovered in a concentrated form for recycle or disposal. Pilot-scale demonstrations have been completed for a variety of waste streams containing low concentrations of metal ions including electroplating wastes (zinc and nickel) and nuclear waste streams (plutonium and americium). Many other potential commercial applications exist including remediation of contaminated solids. An overview of both the pilot-scale demonstrated applications and small scale testing of this technology are presented

Water-soluble metal-binding polymers with ultrafiltration: A technology for the removal, concentration, and recovery of metal ions from aqueous streams

Energy Technology Data Exchange (ETDEWEB)

Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

1997-12-31

The use of water-soluble metal-binding polymers coupled with ultrafiltration (UF) is a technology under development to selectively concentrate and recover valuable or regulated metal-ions from dilute process or waste waters. The polymers have a sufficiently large molecular size that they can be separated and concentrated using commercially available UF technology. The polymers can then be reused by changing the solution conditions to release the metal-ions, which are recovered in a concentrated form for recycle or disposal. Pilot-scale demonstrations have been completed for a variety of waste streams containing low concentrations of metal ions including electroplating wastes (zinc and nickel) and nuclear waste streams (plutonium and americium). Many other potential commercial applications exist including remediation of contaminated solids. An overview of both the pilot-scale demonstrated applications and small scale testing of this technology are presented.

The effect of cation source and dietary cation-anion difference on rumen ion concentrations in lactating dairy cows.

Science.gov (United States)

Catterton, T L; Erdman, R A

2016-08-01

Many studies have focused on the influence of dietary cation-anion difference (DCAD) on animal performance but few have examined the effect of DCAD on the rumen ionic environment. The objective of this study was to examine the effects of DCAD, cation source (Na vs. K), and anion source (Cl vs. bicarbonate or carbonate) on rumen environment and fermentation. The study used 5 rumen-fistulated dairy cows and 5 dietary treatments that were applied using a 5×5 Latin square design with 2-wk experimental periods. Treatments consisted of (1) the basal total mixed ration (TMR); (2) the basal TMR plus 340mEq/kg of Na (dry matter basis) using NaCl; (3) the basal TMR plus 340mEq/kg of K using KCl; (4) the basal TMR plus 340mEq/kg of Na using NaHCO3; and (5) the basal TMR plus 340mEq/kg of K using K2CO3. On the last day of each experimental period, rumen samples were collected and pooled from 5 different locations at 0, 1.5, 3, 4.5, 6, 9, and 12h postfeeding for measurement of rumen pH and concentrations of strong ions and volatile fatty acids (VFA). Dietary supplementation of individual strong ions increased the corresponding rumen ion concentration. Rumen Na was decreased by 24mEq/L when K was substituted for Na in the diet, but added dietary Na had no effect on rumen K. Rumen Cl was increased by 10mEq/L in diets supplemented with Cl. Cation source had no effect on rumen pH or total VFA concentration. Increased DCAD increased rumen pH by 0.10 pH units and increased rumen acetate by 4mEq/L but did not increase total VFA. This study demonstrated that rumen ion concentrations can be manipulated by dietary ion concentrations. If production and feed efficiency responses to DCAD and ionophores in the diet are affected by rumen Na and K concentrations, then manipulating dietary Na and K could be used either to enhance or diminish those responses. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

A novel method for the in situ determination of concentration gradients in the electrolyte of Li-ion Batteries

NARCIS (Netherlands)

Zhou, J.; Danilov, D.; Notten, P.H.L.

2006-01-01

An electrochemical method has been developed for the in situ determination of concentration gradients in the electrolyte of sealed Li-ion batteries by measuring the potential difference between microreference electrodes. Formulas relating the concentration gradient and the potential difference

Metal Ion Concentrations in Body Fluids after Implantation of Hip Replacements with Metal-on-Metal Bearing – Systematic Review of Clinical and Epidemiological Studies

Science.gov (United States)

Hartmann, Albrecht; Hannemann, Franziska; Lützner, Jörg; Seidler, Andreas; Drexler, Hans; Günther, Klaus-Peter; Schmitt, Jochen

2013-01-01

Introduction The use of metal-on-metal (MoM) total hip arthroplasty (THA) increased in the last decades. A release of metal products (i.e. particles, ions, metallo-organic compounds) in these implants may cause local and/or systemic adverse reactions. Metal ion concentrations in body fluids are surrogate measures of metal exposure. Objective To systematically summarize and critically appraise published studies concerning metal ion concentrations after MoM THA. Methods Systematic review of clinical trials (RCTs) and epidemiological studies with assessment of metal ion levels (cobalt, chromium, titanium, nickel, molybdenum) in body fluids after implantation of metalliferous hip replacements. Systematic search in PubMed and Embase in January 2012 supplemented by hand search. Standardized abstraction of pre- and postoperative metal ion concentrations stratified by type of bearing (primary explanatory factor), patient characteristics as well as study quality characteristics (secondary explanatory factors). Results Overall, 104 studies (11 RCTs, 93 epidemiological studies) totaling 9.957 patients with measurement of metal ions in body fluids were identified and analyzed. Consistently, median metal ion concentrations were persistently elevated after implantation of MoM-bearings in all investigated mediums (whole blood, serum, plasma, erythrocytes, urine) irrespective of patient characteristics and study characteristics. In several studies very high serum cobalt concentrations above 50 µg/L were measured (detection limit typically 0.3 µg/L). Highest metal ion concentrations were observed after treatment with stemmed large-head MoM-implants and hip resurfacing arthroplasty. Discussion Due to the risk of local and systemic accumulation of metallic products after treatment with MoM-bearing, risk and benefits should be carefully balanced preoperatively. The authors support a proposed „time out“ for stemmed large-head MoM-THA and recommend a restricted indication for hip

Potassium sorbate-A new aqueous copper corrosion inhibitor

International Nuclear Information System (INIS)

Abelev, Esta; Starosvetsky, David; Ein-Eli, Yair

2007-01-01

This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH 3 CH=CHCH=CHCO 2 )) as an effective copper aqueous corrosion inhibitor. The influence of pH and potassium sorbate concentration on copper corrosion in aerated sulfate and chloride solutions is reported. Degree of copper protection was found to increase with an increase in potassium sorbate concentration; an optimum concentration of this inhibitor in sulfate solutions was found to be 10 g/L. Copper is highly resistant to corrosion attacks by chloride ions in the presence of potassium sorbate. X-ray photoelectron spectroscopy (XPS) studies suggest that copper protection is achieved via the formation of a mixed layer of cuprous oxide, cupric hydroxide and copper(II)-sorbate at the metal surface

Measurement of diffusion coefficient of thallium ion in H2O and D2O systems at different concentrations

International Nuclear Information System (INIS)

Das, A.; Changdar, S.N.

1992-01-01

Sliding cell method, developed in our laboratory, has been used to measure the inter diffusion coefficient of thallium ion in thallous sulphate solution over a wide concentration range using both water and heavy water as solvent at 35degC. The results have been analysed from the point of view of both ion-ion and ion-solvent interactions. The comparison of the diffusivities of the same ion in D 2 O and H 2 O electrolyte solutions at the same temperature indicate that the addition of salt affects the two solvent differently. (author). 8 refs., 1 fig., 1 tab

Influence of chloride ion concentration on the electrochemical corrosion behaviour of plasma electrolytic oxidation coated AM50 magnesium alloy

International Nuclear Information System (INIS)

Liang, J.; Srinivasan, P. Bala; Blawert, C.; Dietzel, W.

2010-01-01

The electrochemical degradation of a silicate- and a phosphate-based plasma electrolytic oxidation (PEO) coated AM50 magnesium alloy obtained using a pulsed DC power supply was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in NaCl solutions of different chloride ion concentrations viz., 0.01 M, 0.1 M, 0.5 M and 1 M. The surface of the PEO coated specimens after 50 h of immersion/EIS testing was examined by optical microscopy and scanning electron microscopy. The results showed that the corrosion deterioration of PEO coated magnesium alloy in NaCl solutions was significantly influenced by chloride ion concentration. The silicate-based coating was found to offer a superior corrosion resistance to the magnesium substrate than the phosphate-based coatings in lower chloride ion concentration NaCl solutions (0.01 M and 0.1 M NaCl). On the other hand both these PEO coatings were found to be highly susceptible to localized damage, and could not provide an effective corrosion protection to Mg alloy substrate in solutions containing higher chloride concentrations (0.5 M and 1 M). The extent of localized damage was observed to be more with increase in chloride concentration in both the cases.

Research on electrochemical methods for concentration measurement of dissolved ion in molten salt to apply to electrolytic process control. Innovative research adopted in 2002 fiscal year

International Nuclear Information System (INIS)

Nagai, Takayuki

2005-03-01

The purpose of this research is to establish the online (in-situ) technique for concentration measuring of dissolved ion in the molten salt, and this technique is due to the electrochemical method for the concentration measuring of dissolved ion in solutions like the polarization curve measurement. This research executed the following four items. 1) Examination of possibility for concentration measuring of dissolved ion in molten salt by cyclic voltammetry. 2) Examination of possibility for concentration measuring of dissolved ion in molten salt by various electrochemical methods. 3) Examination of suitable electrochemical method for concentration measuring of dissolved ion. 4) Confirmation of selected electrochemical method for concentration measuring of dissolved ion. It has been understood that the differential pulse voltammetry (DPV) is a promising electrochemical technique for the concentration measuring of dissolved ion in the molten salt as a result of this research. An appropriate measurement condition is as follows, the potential sweep rate is -0.1 V/s, the pulse cycle is 0.1 s, the pulse width is 10 ms, and the pulse voltage is 50 mV. As for the electrodes, the platinum working electrode, the glassy carbon counter electrode, and silver/silver chloride reference electrode are suitable. Moreover, the molar absorptivities of U 3+ , U 4+ , UO 2 + , UO 2 2+ , and the standard redox potentials of couples of U 4+ /U 3+ and UO 2 2+ /UO 2 + were acquired as a basic data of the uranium and the uranyl ion in molten NaCl-2CsCl. (author)

Leachability of cesium from cemented evaporator concentrates and ion-exchange resins

International Nuclear Information System (INIS)

Muurinen, A.

1985-03-01

Leachabilities of cesium from cemented evaporator concentrates and ion-exchange resins were measured. The standard draft of the International Organization for Standardization (ISO, 1979) for long-term leach testing was followed in the research. Three resin concretes and three concentrate concretes were tested. Deionized water and groundwater were used as leachants. The leaching temperature was 20-23 deg C. The incremental leach rate at the end of the three and a half year test varied between 5x10 -12 - 15x10 -12 m/s and the cumulative activity fraction leached between 1.5x10 -3 - 6x10 -3 m. The apparent diffusion coefficients in groundwater varied between 10 -9 - 10 -8 m/day. Because of the cracking the specimens cannot, however, be regarded as whole blocks, but the effects of cracking should be taken into account. (author)

The pH dependence of silicon-iron interaction in rats.

Science.gov (United States)

Jia, X; Emerick, R J; Kayongo-Male, H

1997-01-01

A 2 x 2 x 3 factorial experiment was conducted to study the pH dependence of a silicon-iron interaction in vivo. The dietary treatments used in the factorial design were the following (mg/kg of diet): silicon, 0 and 500; iron, 35 and 187; acid-base, ammonium chloride as 0.5% of total diet (acidic), sodium bicarbonate as 1.0% of total diet (basic), or no supplementation of acid or base (control). The supplementation of 500 mg silicon/kg of diet increased plasma-iron concentration in rats fed the acidic or control diets, but not in rats fed the basic diet. A high dietary-iron level suppressed copper absorption and utilization and subsequently imposed a negative effect on its own utilization. An increase in the plasma total-cholesterol concentration caused by high dietary-iron level was likely a consequence of the antagonistic effect of iron on copper absorption and utilization. The use of cupric sulfate pentahydrate as the dietary-copper source in this study resulted in plasma copper concentrations that were approximately twice those obtained in a related study using cupric carbonate. Also, a 42% coefficient of variation (C.V.) for plasma-copper concentrations of rats fed cupric sulfate in this study was greatly reduced from the C.V. = 108% previously associated with the dietary cupric carbonate.

Impact of incoherent pumping field and Er3+ ion concentration on group velocity and index of refraction in an Er3+-doped YAG crystal

International Nuclear Information System (INIS)

Jafarzadeh, Hossein; Asadpour, Seyyed Hossein; Soleimani, H Rahimpour

2015-01-01

The effect of Er 3+ ion concentration and incoherent pumping field on the refractive index and group index in an Er 3+ : YAG crystal is investigated. It is shown that under different concentrations of Er 3+ ion in the crystal, the index of refraction and absorption can be changed and a high index of refraction is accompanied by amplification in the medium. Also, it is shown that with the switching from subluminal to superluminal, or vice versa, light propagation can be obtained by different concentrations of Er 3+ ions in the crystal. (paper)

On the concept of resting potential--pumping ratio of the Na⁺/K⁺ pump and concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell.

Science.gov (United States)

Xu, Ning

2013-01-01

In animal cells, the resting potential is established by the concentration gradients of sodium and potassium ions and the different permeabilities of the cell membrane to them. The large concentration gradients of sodium and potassium ions are maintained by the Na⁺/K⁺ pump. Under physiological conditions, the pump transports three sodium ions out of and two potassium ions into the cell per ATP hydrolyzed. However, unlike other primary or secondary active transporters, the Na⁺/K⁺ pump does not work at the equilibrium state, so the pumping ratio is not a thermodynamic property of the pump. In this article, I propose a dipole-charging model of the Na⁺/K⁺ pump to prove that the three Na⁺ to two K⁺ pumping ratio of the Na⁺/K⁺ pump is determined by the ratio of the ionic mobilities of potassium to sodium ions, which is to ensure the time constant τ and the τ-dependent processes, such as the normal working state of the Na⁺/K⁺ pump and the propagation of an action potential. Further, the concentration ratios of potassium ions outside and inside the cell to sodium ions inside and outside the cell are 0.3027 and 0.9788, respectively, and the sum of the potassium and sodium equilibrium potentials is -30.3 mV. A comparative study on these constants is made for some marine, freshwater and terrestrial animals. These findings suggest that the pumping ratio of the Na⁺/K⁺ pump and the ion concentration ratios play a role in the evolution of animal cells.

Measurement and interpretation of low levels of dissolved oxygen in ground water

Science.gov (United States)

White, A.F.; Peterson, M.L.; Solbau, R.D.

1990-01-01

A Rhodazine-D colorimetric technique was adapted to measure low-level dissolved oxygen concentrations in ground water. Prepared samples containing between 0 and 8.0 ??moles L-1 dissolved oxygen in equilibrium with known gas mixtures produced linear spectrophotometric absorbance with a lower detection limit of 0.2 ??moles L-1. Excellent reproducibility was found for solutions ranging in composition from deionized water to sea water with chemical interferences detected only for easily reduced metal species such as ferric ion, cupric ion, and hexavalent chromium. Such effects were correctable based on parallel reaction stoichiometries relative to oxygen. The technique, coupled with a downhole wire line tool, permitted low-level monitoring of dissolved oxygen in wells at the selenium-contaminated Kesterson Reservoir in California. Results indicated a close association between low but measurable dissolved oxygen concentrations and mobility of oxidized forms of selenium. -from Authors

Survey of chemical compounds tested in vitro against rumen protozoa for possible control of bloat.

Science.gov (United States)

Willard, F L; Kodras, R

1967-09-01

Over 170 chemical agents were screened for antiprotozoal action in bovine ruminal fluid. Compounds were tested at 0.1 and 0.05% concentrations. Tested compounds included inorganic compounds, antibiotics, biocides, neuromuscular agents, arsenicals, plant and animal hormones, antimalarials, surface-active agents, anthelmintics, and many others. The most active compounds were cupric sulfate, nickel sulfate, nitrofurazone, hydrogen peroxide, dodecyl sodium sulfate, pelargonic acid, iodoacetic acid, 1-diethylaminoethylamino-4-methylthiaxanthrone, sodium arsanilate, sodium arsenate, bismuth glycolyl arsanilate, 1-beta-hydroxyethyl-2-methyl-5-nitroimidazole, and p-nitroaniline. Copper ion was not particularly effective against entodinia; nickel ion had no effect on holotrichs. Hydrogen peroxide and iodoacetic acid were effective at a concentration of 0.005%. Anionic surface-active agents were very effective, especially long-chain sulfates and phosphates. These antiprotozoal agents warrant further in vivo studies for possible use in treating or curing bloat in ruminants.

DETERMINATION OF STRONTIUM IONS IN WATERS WITH A HIGH CONTENT OF SODIUM IONS

Directory of Open Access Journals (Sweden)

Tatiana Mitina

2015-06-01

Full Text Available This paper reports on the influence of sodium ions on experimental determination of strontium ions concentration in waters with a high content of sodium ions by using emission flame photometry and atomic absorption spectroscopy. For the method of emission flame photometry it was shown that at a wavelength of 460.7 nm (spectral emission line of strontium the emission is linearly dependent on the concentration of sodium ions. The greatest impact of high concentrations of sodium ions on the result of determination the strontium ions concentration has been registered at low levels of strontium. The influence of nitric acid on the results is also discussed. In the case of using atomic absorption spectroscopy method no influence of sodium ions and nitric acid on the results of determination the strontium ions concentration was revealed. The metrological characteristics of both methods are evaluated.

Effect of DSPE-PEG on compound action potential, injury potential and ion concentration following compression in ex vivo spinal cord.

Science.gov (United States)

Wang, Aihua; Huo, Xiaolin; Zhang, Guanghao; Wang, Xiaochen; Zhang, Cheng; Wu, Changzhe; Rong, Wei; Xu, Jing; Song, Tao

2016-05-04

It has been shown that polyethylene glycol (PEG) can reseal membrane disruption on the spinal cord, but only high concentrations of PEG have been shown to have this effect. Therefore, the effect of PEG is somewhat limited, and it is necessary to investigate a new approach to repair spinal cord injury. This study assesses the ability of 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly (ethylene glycol)) 2000] (DSPE-PEG) to recover physiological function and attenuate the injury-induced influx of extracellular ions in ex vivo spinal cord injury. Isolated spinal cords were subjected to compression injury and treated with PEG or DSPE-PEG immediately after injury. The compound action potential (CAP) was recorded before and after injury to assess the functional recovery. Furthermore, injury potential, the difference in gap potentials before and after compression, and the concentration of intracellular ions were used to evaluate the effect of DSPE-PEG on reducing ion influx. Data showed that the injury potential and ion concentration of the untreated, PEG and DSPE-PEG group, without significant difference among them, are remarkably higher than those of the intact group. Moreover, the CAP recovery of the DSPE-PEG and PEG treated spinal cords was significantly greater than that of the untreated spinal cords. The level of CAP recovery in the DSPE-PEG and PEG treated groups was the same, but the concentration of DSPE-PEG used was much lower than the concentration of PEG. These results suggest that instant application of DSPE-PEG could effectively repair functional disturbance in SCI at a much lower concentration than PEG. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation using Zymomonas mobilis 2716

Energy Technology Data Exchange (ETDEWEB)

Doelle, M.B.; Doelle, H.W. (Queensland Univ., St. Lucia (Australia). Dept. of Microbiology); Greenfield, P.F. (Queensland Univ., St. Lucia (Australia). Dept. of Chemical Engineering)

1990-11-01

Investigations into the relationship between sucrose hydrolysis, sorbitol formation and mineral ion concentration during bioethanol formation by Zymomonas mobilis 2716 revealed two distinct phenomena responsible for carbon flow diversion, a 'sucrose effect' and a 'salt effect'. Neither of the two phenomena affects sucrose hydrolysis, but they divert carbon flow of the fructose monomer leading to its own accumulation, sorbitol or oligosaccharide formation. Sucrose concentrations in excess of 15% (w/v) led to sorbitol formation, the level of which may exceed 2% (w/v) depending upon glucose accumulation during sucrose hydrolysis. Increasing mineral ion concentrations led initially to carbon losses and finally to fructose accumulation instead of sorbitol formation. This carbon loss can be corrected by the addition of invertase, which in turn leads to an increase in sorbitol, fructose and ethanol. Potassium and chloride are the dominant ions responsible for suppression of sorbitol formation and fructose uptake, encouraging oligosaccharide formation. These fructooligosaccharides must be of a type which can be converted to fructose, sorbitol and ethanol through the action of invertase. The requirement of invertase addition to prevent fructooligosaccharide formation is indirect evidence that Z. mobilis 2716 does not produce invertase. (orig.).

Improved Technique for the Determination of Uranium Minor Isotopes Concentrations in Microparticles by Using Secondary Ion Mass-Spectrometer in Multicollection Mode

International Nuclear Information System (INIS)

Aleshin, M.; Elantyev, I.; Stebelkov, Y.

2015-01-01

Traditional method of the analysis implies simultaneous measuring of secondary ion currents of isotopes 234U + , 235U + , 238U + , ions with mass 236 amu (236U + and 235UH + ) and hydride ions 238UH + by using mass-spectrometer Cameca IMS1280 in multicollection mode. Calculating of uranium isotopic composition is performed using the results of 40 successive measurements of those currents (cycles). Duration of each measurement is 8 s. Small amounts of uranium minor isotopes are limitation for precise determination of their concentrations. To prevent the damage of the secondary ions detector the intensity of ion current should be no more than 5 x 10 5 s -1 . This limitation does not allow setting a higher primary ion current for the increasing of minor uranium isotopes ions emission because of the signal of ions 238U + gets too high. New technique is developed to improve the accuracy of determination of uranium minor isotopes concentrations. Process of measurement is divided on two steps. First step is a measurement of ion currents during 20 cycles by five detectors. The second step implies the elimination of ions 238U + hitting to the detector and 10 times increasing of primary ion current. The ratio 235U/238U is calculated from the first step results, so uncertainty of determination of this value is 1.4 times bigger than with duration of 40 cycles of the measurement. The ratios 234U/235U and 236U/235U are calculated during the second step. This technique allows to determine content of 234U and 236U with 3 and 5 times less uncertainties respectively, but with different degree of the sputtering particles. Moreover the duration of each cycle was set less (1 second) to use data more efficient. The technique accordingly with every second counting provides uncertainty of determination 236U concentration 4 times less than traditional method at the same degree of sputtering particles. (author)

Determination of HCl and VOC Emission from Thermal Degradation of PVC in the Absence and Presence of Copper, Copper(II Oxide and Copper(II Chloride

Directory of Open Access Journals (Sweden)

Ahamad J. Jafari

2009-01-01

Full Text Available Polyvinyl chloride (PVC has played a key role in the development of the plastic industry over the past 40 years. Thermal degradation of PVC leads to formation of many toxic pollutants such as HCl, aromatic and volatile organic carbon vapors. Thermal degradation of PVC and PVC in the present of copper, cupric oxide and copper(II chloride were investigated in this study using a laboratory scale electrical furnace. HCl and Cl- ion were analyzed by a Dionex ion chromatograph and VOCs compounds were analyzed using GC or GC-MS. The results showed that HCl plus Cl- ion and benzene formed about 99% and 80% respectively in the first step of thermal degradation under air atmosphere. The presence of cupric oxide increases the percentage of short chain hydrocarbons more than 184% and decreases the amount of the major aromatic hydrocarbon and HCl plus Cl- ion to 90% and 65% respectively. The total aromatic hydrocarbon emitted less than when atmosphere was air and difference was statistically significant (Pvalue<0.000

Development of ion-exchange properties of bamboo charcoal modified with concentrated nitric acid

Science.gov (United States)

Khandaker, S.; Kuba, T.; Toyohara, Y.; Kamida, S.; Uchikawa, Y.

2017-08-01

The surface chemistry and the structural properties of activated carbon can be altered by the acidic modification. The objective of this study is to investigate the changes occurring in bamboo charcoal (BC) during activation with concentrated nitric acid. Low temperature (500°C) carbonized BC has been prepared and oxidized with 70% concentrated boiling nitric acid (BC-AC). The porous properties of the BC are analyzed with nitrogen adsorption isotherm at 77 K. The surface structure is observed by Field emission scanning electronic microscope (FESEM) and the surface functional groups are examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and the pH of the point of zero charge (pHPZC). The results reveal that severe oxidation with HNO3 considerably decreases the surface area of BC with enhanced pore widening and FESEM observation demonstrates the erosive effect of oxidation. The FTIR analysis detects that some absorption bands are assigned for carboxyl, aldehyde and ketone groups on BC-AC. The XPS analysis also clearly shows that the ratio of oxygen and acidic functional groups has been enriched significantly on the BC-AC. The low pHPZC value of BC-AC confirms that the surface is highly acidic for the fixation of acidic functional groups on surface. In general, the existence of the abundant amount of acidic functional groups on adsorbents enhances the sorption of heavy metals ions in aqueous solution. Therefore, it is strongly expected that the modified BC, activated under the proposed conditions would be a promising ion exchanger in aqueous solution and can be applied for the adsorption of different heavy metal ions and radioactive materials from effluent.

Influence of different concentration of heavy metals on the seed ...

African Journals Online (AJOL)

use

0.001, 0.01, 0.1 and 1%) of lead acetate, cupric carbonate and ferric chloride were ... nutrients and seem to be more or less toxic to plants and ... Some heavy metals at low doses are essential ..... The toxic action and interactions of copper.

Handheld Device Adapted to Smartphone Cameras for the Measurement of Sodium Ion Concentrations at Saliva-Relevant Levels via Fluorescence

Directory of Open Access Journals (Sweden)

Michelle Lipowicz

2015-06-01

Full Text Available The use of saliva sampling as a minimally-invasive means for drug testing and monitoring physiology is a subject of great interest to researchers and clinicians. This study describes a new optical method based on non-axially symmetric focusing of light using an oblate spheroid sample chamber. The device is simple, lightweight, low cost and is easily attached to several different brands/models of smartphones (Apple, Samsung, HTC and Nokia for the measurement of sodium ion levels at physiologically-relevant saliva concentrations. The sample and fluorescent reagent solutions are placed in a specially-designed, lightweight device that excludes ambient light and concentrates 470-nm excitation light, from a low-power photodiode, within the sample through non-axially-symmetric refraction. The study found that smartphone cameras and post-image processing quantitated sodium ion concentration in water over the range of 0.5–10 mM, yielding best-fit regressions of the data that agree well with a data regression of microplate luminometer results. The data suggest that fluorescence can be used for the measurement of salivary sodium ion concentrations in low-resource or point-of-care settings. With further fluorescent assay testing, the device may find application in a variety of enzymatic or chemical assays.

preparation of beryllia n concentrate from beryllium minerals by ion exchange method

International Nuclear Information System (INIS)

Shoukry, M.M.; Atrees, M. Sh.; Hashem, M.D.

2007-01-01

The present work is concerned with the preparation of pure Beryllia concentrate from Zabara beryl mineralization in the mica schist of Wadi El Gemal area in the eastern desert. This has been possible through application of ion exchange techniques to selectively concentrate. This method is based on the fact that the beryllium complex of ethylene diamine tetra acetic acid (EDTA) at a ph of about 3.5, is much weaker than the corresponding complexes of iron and aluminum. It was, therefore, possible to effect a complete separation of beryllium from the latter on a cation exchange resin, the studied optimum conditions of separation include a contact time of 3 minute and ph of 3.5 for the selective separation of beryllium from its EDTA solution after a prior separation of alum

Determination of the free ion concentration of trace metals in soil solution using a soil column Donnan membrane technique

NARCIS (Netherlands)

Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

2001-01-01

Accurate measurement of the free metal ion is difficult, especially for trace metals present in very small concentrations (less than micromolar) in natural systems. The recently developed Donnan membrane technique can measure the concentrations in solution in the presence of inorganic and organic

Dispersive liquid-liquid microextraction of copper ions as neocuproine complex in environmental aqueous samples.

Science.gov (United States)

Shariati, Shahab; Golshekan, Mostafa

2011-06-01

In the present study, a simple and efficient extraction method based on dispersive liquid-liquid microextraction prior to UV-Vis spectrophotometry was developed for the preconcentration and determination of copper ions in environmental samples. Briefly, cupric ions (Cu II) were reduced to cuprous (Cu I) with addition of hydroxyl amine hydrochloride and formed hydrophobic chelates with neocuproine. Then, a proper mixture of acetonitrile (as dispersive solvent) and choloroform (as extraction solvent) was rapidly injected into the solution and a cloudy solution was formed. After centrifuging, choloroform was sedimented at the bottom of a conical tube and diluted with 100 µL of methanol for further UV-Vis spectrophotometry measurement. An orthogonal array design (OAD) was employed to study the effects of different parameters on the extraction efficiency. Under the optimum experimental conditions, a preconcentration factor up to 63.6 was achieved for extraction from 5.0 mL of sample solution. The limit of detection (LOD) based on S/N = 3 was 0.33 µg L-1 and the calibration curve was linear in the range of 1-200 µg L-1 with reasonable linearity (r2 > 0.997). Finally, the accuracy of the proposed method was successfully evaluated by determination of trace amounts of copper ions in different water samples and satisfactory results were obtained.

The effect of magnesium ion concentration on the fibrocartilage regeneration potential of goat costal chondrocytes.

Science.gov (United States)

Hagandora, Catherine K; Tudares, Mauro A; Almarza, Alejandro J

2012-03-01

Magnesium has recently been explored as a potential biomaterial for degradable orthopedic implants but its effect on fibrocartilage remains unknown. The objective of this study was to assess the effect of high concentrations of magnesium ions on the matrix production of goat costal fibrochondrocytes in vitro. Cells were cultured using a scaffoldless approach with media containing magnesium chloride (MgCl(2)) or magnesium sulfate (MgSO(4)) at concentrations of 20, 50, and 100 mM in addition to the baseline magnesium concentration of 0.8 mM MgSO(4). At 4 weeks, there were no significant differences in compressive tangent modulus and total matrix production between constructs cultured in 20 mM Mg(2+) and the 0.8 mM Mg(2+) control (435 ± 47 kPa). There was a significant decrease in compressive tangent modulus compared to the 0.8 mM Mg(2+) constructs in the 50 mM MgCl(2) and MgSO(4) groups, while the 100 mM groups were not mechanically testable (p < 0.05). The collagen and glycosaminoglycan (GAG) content of the 50 and 100 mM MgCl(2) and MgSO(4) constructs was significantly lower than the control (6.9 ± 0.5% and 16.5 ± 1.3% per dry weight, respectively) (p < 0.05). The results show that goat costal fibrochondrocytes exhibit a high degree of resiliency to magnesium ion concentrations up to 20 mM in vitro.

Ion association in concentrated NaCl brines from ambient to supercritical conditions: results from classical molecular dynamics simulations

Directory of Open Access Journals (Sweden)

Collings Matthew D

2002-11-01

Full Text Available Highly concentrated NaCl brines are important geothermal fluids; chloride complexation of metals in such brines increases the solubility of minerals and plays a fundamental role in the genesis of hydrothermal ore deposits. There is experimental evidence that the molecular nature of the NaCl–water system changes over the pressure–temperature range of the Earth's crust. A transition of concentrated NaCl–H2O brines to a "hydrous molten salt" at high P and T has been argued to stabilize an aqueous fluid phase in the deep crust. In this work, we have done molecular dynamic simulations using classical potentials to determine the nature of concentrated (0.5–16 m NaCl–water mixtures under ambient (25°C, 1 bar, hydrothermal (325°C, 1 kbar and deep crustal (625°C, 15 kbar conditions. We used the well-established SPCE model for water together with the Smith and Dang Lennard-Jones potentials for the ions (J. Chem. Phys., 1994, 100, 3757. With increasing temperature at 1 kbar, the dielectric constant of water decreases to give extensive ion-association and the formation of polyatomic (NanClmn-m clusters in addition to simple NaCl ion pairs. Large polyatomic (NanClmn-m clusters resemble what would be expected in a hydrous NaCl melt in which water and NaCl were completely miscible. Although ion association decreases with pressure, temperatures of 625°C are not enough to overcome pressures of 15 kbar; consequently, there is still enhanced Na–Cl association in brines under deep crustal conditions.

Mechanisms of an increased level of serum iron in gamma-irradiated mice

International Nuclear Information System (INIS)

Xie, Li-hua; Zhang, Xiao-hong; Hu, Xiao-dan; Min, Xuan-yu; Zhou, Qi-fu; Zhang, Hai-qian

2016-01-01

The potential mechanisms underlying the increase in serum iron concentration in gamma-irradiated mice were studied. The gamma irradiation dose used was 4 Gy, and cobalt-60 ( 60 Co) source was used for the irradiation. The dose rate was 0.25 Gy/min. In the serum of irradiated mice, the concentration of ferrous ions decreased, whereas the serum iron concentration increased. The concentration of ferrous ions in irradiated mice returned to normal at 21 day post-exposure. The concentration of reactive oxygen species in irradiated mice increased immediately following irradiation but returned to normal at 7 day post-exposure. Serum iron concentration in gamma-irradiated mice that were pretreated with reduced glutathione was significant lower (p < 0.01) than that in mice exposed to gamma radiation only. However, the serum iron concentration was still higher than that in normal mice (p < 0.01). This change was biphasic, characterized by a maximal decrease phase occurring immediately after gamma irradiation (relative to the irradiated mice) and a recovery plateau observed during the 7th and 21st day post-irradiation, but serum iron recovery was still less than that in the gamma-irradiated mice (4 Gy). In gamma-irradiated mice, ceruloplasmin activity increased and serum copper concentration decreased immediately after irradiation, and both of them were constant during the 7th and 21st day post-irradiation. It was concluded that ferrous ions in irradiated mice were oxidized to ferric ions by ionizing radiation. Free radicals induced by gamma radiation and ceruloplasmin mutually participated in this oxidation process. The ferroxidase effect of ceruloplasmin was achieved by transfer of electrons from ferrous ions to cupric ions. (orig.)

Heating tokamaks via the ion-cyclotron and ion-ion hybrid resonances

International Nuclear Information System (INIS)

Perkins, F.W.

1977-04-01

For the ion-ion hybrid resonance it is shown that: (1) the energy absorption occurs via a sequence of mode conversions; (2) a poloidal field component normal to the ion-ion hybrid mode conversion surface strongly influences the mode conversion process so that roughly equal electron and ion heating occurs in the present proton-deuterium experiments, while solely electron heating is predicted to prevail in deuterium-tritium reactors; (3) the ion-ion hybrid resonance suppresses toroidal eigenmodes; and (4) wave absorption in minority fundamental ion-cyclotron heating experiments will be dominated by ion-ion hybrid mode conversion absorption for minority concentrations exceeding roughly 1 percent. For the ion-cyclotron resonance, it is shown that: (1) ion-cyclotron mode conversion leads to surface electron heating; and (2) ion-cyclotron mode conversion absorption dominates fundamental ion-cyclotron absorption thereby preventing efficient ion heating

Major Ion Concentrations in WDC05Q and WDC06A Ice Cores (WAIS Divide), Version 1

Data.gov (United States)

National Aeronautics and Space Administration — This data set contains major ion concentrations from the chemical analysis of two WAIS Divide ice cores (WDC05Q, 0-114 m; WDC06A, 0-129 m). The analytical technique...

Underscreening in concentrated electrolytes.

Science.gov (United States)

Lee, Alpha A; Perez-Martinez, Carla S; Smith, Alexander M; Perkin, Susan

2017-07-01

Screening of a surface charge by an electrolyte and the resulting interaction energy between charged objects is of fundamental importance in scenarios from bio-molecular interactions to energy storage. The conventional wisdom is that the interaction energy decays exponentially with object separation and the decay length is a decreasing function of ion concentration; the interaction is thus negligible in a concentrated electrolyte. Contrary to this conventional wisdom, we have shown by surface force measurements that the decay length is an increasing function of ion concentration and Bjerrum length for concentrated electrolytes. In this paper we report surface force measurements to test directly the scaling of the screening length with Bjerrum length. Furthermore, we identify a relationship between the concentration dependence of this screening length and empirical measurements of activity coefficient and differential capacitance. The dependence of the screening length on the ion concentration and the Bjerrum length can be explained by a simple scaling conjecture based on the physical intuition that solvent molecules, rather than ions, are charge carriers in a concentrated electrolyte.

Effect of organic solvents on desorption and atomic absorption determination of heavy metal ions after ion exchange concentration

International Nuclear Information System (INIS)

Pilipenko, A.T.; Safronova, V.G.; Zakrevskaya, L.V.

1986-01-01

The effect of organic solvents (acetone, methylethylketone, dioxane, ethanol) on desorption of Cu, Mn, Co, Cd, Zn, Pb, Ni from cationite KU-23 ion exchange resin and on the detection limits of their atomic absorption determination has been examined. Cobalt and cadmium can be separated quantitatively using desorption by a mixture of HCl and acetone. Addition of an organic solvent results in a higher absorbance, mainly due to a high rate and efficiency of atomization. Acetone has proved to be the best solvent: addition of 60 vol. % of this solvent to the concentrate provides 2 times lower detection limits for the heavy metas in water

Enhancement of heat dissipation of LED module with cupric-oxide composite coating on aluminum-alloy heat sink

International Nuclear Information System (INIS)

Kim, Donghyun; Lee, Junghoon; Kim, Junho; Choi, Chang-Hwan; Chung, Wonsub

2015-01-01

Highlights: • We fabricate the CuO/resin composite coating layer on aluminum alloy heat sink. • CuO/resin coating considerably improved the surface emissivity. • The LED junction temperature was reduced by CuO/resin coated heat sink. • The thermal resistance of heat sink was decreased by CuO/resin composite coating at 200 μm thickness. - Abstract: A composite coating composed of cupric oxide (CuO) and silicon-based resin was applied to an aluminum-alloy heat sink for a light emitting diode (LED) module. The purpose of the composite coating is to improve the heat dissipation performance of heat sink by enhancing thermal radiation emission. The heat dissipation performance was investigated in terms of LED junction temperature and thermal resistance using a thermal transient method. The CuO and silicon-based resin composite coating showed higher emissivity, and the lower junction temperature and thermal resistance of the heat sink was achieved. In addition, a continuous operation test of the LED chip with the heat sink revealed that the surface treated with the CuO composite coating stably dissipated heat without degradation. In conclusion, the composite coating proposed here showed a significant improvement of the heat dissipation performance of the aluminum-alloy heat sink due to the enhanced thermal radiation property.

The Effect of Low Level Laser Therapy on Some Plasma Ions Concentration

Directory of Open Access Journals (Sweden)

Nadia H. Sahib

2017-12-01

two pore leak channels(K2P, which act as signal integrators from the periphery to the cortex. Objectives and Results Fifteen blood samples were collected from healthy adult volunteers, subjected to low level laser therapy  (LLLT with different wavelengths (650, 532 and 405 nm, plasma concentration of Ca++, Na+, K+ and Cl- were estimated after (30 min. of incubation. The mean concentration of each ion before and after LLLT were as follows (Ca++: 8.67 vs. 8.93, 8.79, 8.82 mg/dl, (Na+: 147.4 vs. 146.73, 146.73, 146.13 mmol/L, (K+: 3.94 vs. 3.94, 3.78, 3.92 mmol/L and (Cl-: 99.93 vs. 97.86, 102.73, 96.4 mmol/L. In the same manner, activated partial thromboplastin time (APTT was estimated, the mean value of which were as follows (30.07 vs. 18.45, 21.72, 17.29 sec..

A nonlocal species concentration theory for diffusion and phase changes in electrode particles of lithium ion batteries

Science.gov (United States)

Zhang, Tao; Kamlah, Marc

2018-01-01

A nonlocal species concentration theory for diffusion and phase changes is introduced from a nonlocal free energy density. It can be applied, say, to electrode materials of lithium ion batteries. This theory incorporates two second-order partial differential equations involving second-order spatial derivatives of species concentration and an additional variable called nonlocal species concentration. Nonlocal species concentration theory can be interpreted as an extension of the Cahn-Hilliard theory. In principle, nonlocal effects beyond an infinitesimal neighborhood are taken into account. In this theory, the nonlocal free energy density is split into the penalty energy density and the variance energy density. The thickness of the interface between two phases in phase segregated states of a material is controlled by a normalized penalty energy coefficient and a characteristic interface length scale. We implemented the theory in COMSOL Multiphysics^{circledR } for a spherically symmetric boundary value problem of lithium insertion into a Li_xMn_2O_4 cathode material particle of a lithium ion battery. The two above-mentioned material parameters controlling the interface are determined for Li_xMn_2O_4 , and the interface evolution is studied. Comparison to the Cahn-Hilliard theory shows that nonlocal species concentration theory is superior when simulating problems where the dimensions of the microstructure such as phase boundaries are of the same order of magnitude as the problem size. This is typically the case in nanosized particles of phase-separating electrode materials. For example, the nonlocality of nonlocal species concentration theory turns out to make the interface of the local concentration field thinner than in Cahn-Hilliard theory.

Effect of cupric salts (Cu (NO{sub 3}){sub 2}, CuSO4{sub ,} Cu(CH{sub 3}COO){sub 2}) on Cu{sub 2}(OH)PO{sub 4} morphology for photocatalytic degradation of 2,4-dichlorophenol under near-infrared light irradiation

Energy Technology Data Exchange (ETDEWEB)

Hu, Chao; Li, Pei; Zhang, Wei; Che, Yanhao; Sun, Yaxin; Chi, Fangli; Ran, Songlin; Liu, Xianguo; Lv, Yaohui, E-mail: yaohui2015@163.com [School of Materials Science and Engineering, Anhui Key Laboratory of Metal Materials and Processing, Anhui University of Technology (China)

2017-03-15

Cu{sub 2}(OH)PO{sub 4} microstructures were synthesized by the hydrothermal method using three different types cupric salts (Cu (NO{sub 3}){sub 2}, CuSO{sub 4}, Cu(CH{sub 3}COO){sub 2}) as raw materials. The X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible-NIR absorption spectra were used to characterize the as-obtained products. The different anions (SO{sub 4}{sup 2-}, CH{sub 3}COO-, NO{sub 3-}) have different shapes and polarities, which can generate different interactions in reaction bath, induced the difference of structure and morphology of the prepared Cu{sub 2}(OH)PO{sub 4}. The Cu{sub 2}(OH)PO{sub 4} microstructures prepared form Cu(NO{sub 3}){sub 2} ·3H{sub 2}O showed the best photocatalytic activity induced by near-infrared light to degrade 2,4-dichlorophenol (2,4-DCP) solution. Our work suggests that the active morphological surfaces as well as different coordination environments for the metal ions has an important influence on the photocatalytic performance of Cu{sub 2}(OH)PO{sub 4} microstructure. (author)

Observation of ion-acoustic rarefaction solitons in a multicomponent plasma with negative ions

International Nuclear Information System (INIS)

Ludwig, G.O.; Ferreira, J.L.; Nakamura, Y.

1984-01-01

The propagation of ion-acoustic solitons in a plasma with negative ions has been observed. For sufficiently large concentration of negative ions, applied rarefactive (negative) voltage pulses break up into solitons, whereas compressive pulses evolve into wave trains, with exactly the opposite behavior as that for a plasma composed only of positive ions. There is a critical value of the negative-ion concentration for which a finite-amplitude pulse propagates without steepening

Lysimeter study with a cambric arenosol exposed to artificial acid rain: I. Concentrations of ions in leachate

International Nuclear Information System (INIS)

Sogn, T.A.; Abrahamsen, G.; Stuanes, A.O.

1993-01-01

The effects of artificial acid rain on soil leachate composition were studied in a lysimeter experiment. Cambic Arenosol (Typic Udipsamment) in monolith lysimeters was treated for 6 1/2 year with 125 mm yr -1 artificial rain in addition to natural precipitation. Artificial acid rain was produced from groundwater with H 2 SO 4 added. pH levels of 6.1, 4 and 3 were used. Increasing content of H 2 SO 4 in the artificial rain increased the concentration of Ca 2+ and Mg 2+ in the leachate significantly. The pH of the leachate was slightly reduced only by the most acidic treatment (pH 3). The H + retention was not accompanied by a proportionate increase in the Al ion concentration. A slight increase in the Al ion concentration was only observed in the leachate from the pH 3-treated lysimeter. It is concluded that cation exchange and/or weathering were the main buffer mechanisms in the soil. The study supports conclusions from other acidification studies, that acidic precipitation is likely to increase the leaching of Ca 2+ and Mg 2+ from soils. 25 refs., 3 figs., 7 tabs

THE HYDROGEN ION CONCENTRATION OF JOINT EXUDATES IN RHEUMATIC FEVER AND OTHER FORMS OF ARTHRITIS.

Science.gov (United States)

Boots, R H; Cullen, G E

1922-09-30

1. The hydrogen ion concentration of joint exudates aspirated from patients ill with acute rheumatic fever, arthritis of undetermined origin, and bacterial arthritis was determined. The hydrogen ion concentrations of the joint exudates from patients with acute rheumatic fever approximated the normal reaction of blood, varying from pH 7.27 to 7.42. Exudates from patients with arthritis of undetermined origin varied in pH from 7.33 to 7.47. The pH of a joint effusion occurring in a patient with myocardial insufficiency was 7.34. Bacteriologically, all of these fluids were sterile by ordinary means of cultivation. An exudate aspirated from a knee infected with Staphylococcus aureus had a pH of 6.69, while that from a patient having an arthritis due to Streptococcus hoemolyticus was also acid, having a pH of 6.19. 2. Since a definitely acid medium is necessary for the liberation of free salicylic acid and since all of the joint fluids from patients with acute rheumatic fever were slightly alkaline, no free salicylic acid could possibly exist in such joint fluids following the administration of salicylates.

Flow injection spectrophotometric determination of low concentrations of orthosphate in natural waters employing ion exchange resin

International Nuclear Information System (INIS)

Pessenda, L.C.R.

1981-01-01

A simple and fast method for the determination of low concentrations of orthophosphate in natural waters is described. Ion exchange is incorporated into a flow injection system by usina a resin column in the sample loop of a proportion injector. Effects of sample aspiration rate, sampling time, eluting agent concentration, pumping rate of the sample carrier stream and interfaces, were investigated both using 32 PO 3- 4 or 31 PO 3- 4 with columns coupled to a gerger-muller detector and incorporated in a flow system with molybdenum blue colorinetry. (M.A.C.) [pt

Determination of Trace Anions in Concentrated Hydrogen Peroxide by Direct Injection Ion Chromatography with Conductivity Detection after Pt-Catalyzed On-Line Decomposition

International Nuclear Information System (INIS)

Kim, Do Hee; Lee, Bo Kyung; Lee, Dong Soo

1999-01-01

A method has been developed for the determination of trace anion impurities in concentrated hydrogen peroxide. The method involves on-line decomposition of hydrogen peroxide, ion chromatographic separation and subsequent suppressed-type conductivity detection. H 2 O 2 is decomposed in Pt-catalyst filled Gore-Tex membrane tubing and the resulting aqueous solution containing analytes is introduced to the injection valve of an ion chromatograph for periodic determinations. The oxygen gas evolving within the membrane tubing escapes freely through the membrane wall causing no problem in ion chromatographic analysis. Decomposition efficiency is above 99.99% at a flow rate of 0.4mL/min for a 30% hydrogen peroxide concentration. Analytes are quantitatively retained. The analysis results for several brands of commercial hydrogen peroxides are reported

[Serial change of perilymphatic potassium ion concentration in the scala tympani after introducing KCl-solution into the guinea pigs' tympanic cavity].

Science.gov (United States)

Ikeno, K

1990-09-01

Characteristic nystagmus similar to the Meniere's attack could be observed after introducing KCl solution into the tympanic cavity of guinea pigs. To confirm the fact that this nystagmus was provoked by the high perilymphatic potassium ion concentration, the K+ activity of perilymph was recorded serially through the K+ specific microelectrode inserted into the scala tympani. The rapid increment of K+ activity reached maximum at 120 minutes after introducing KCl solution, and then it decreased gradually to a half of the maximum activity. However, such change of perilymphatic potassium ion concentration was not observed by introducing sucrose solution as control.

Ion concentration in micro and nanoscale electrospray emitters.

Science.gov (United States)

Yuill, Elizabeth M; Baker, Lane A

2018-06-01

Solution-phase ion transport during electrospray has been characterized for nanopipettes, or glass capillaries pulled to nanoscale tip dimensions, and micron-sized electrospray ionization emitters. Direct visualization of charged fluorophores during the electrospray process is used to evaluate impacts of emitter size, ionic strength, analyte size, and pressure-driven flow on heterogeneous ion transport during electrospray. Mass spectrometric measurements of positively- and negatively-charged proteins were taken for micron-sized and nanopipette emitters under low ionic strength conditions to further illustrate a discrepancy in solution-driven transport of charged analytes. A fundamental understanding of analyte electromigration during electrospray, which is not always considered, is expected to provide control over selective analyte depletion and enrichment, and can be harnessed for sample cleanup. Graphical abstract Fluorescence micrographs of ion migration in nanoscale pipettes while solution is electrosprayed.

Demonstration on endurance of ion exchange membrane immersed in high-concentration tritiated water under the Broader Approach Activities

Energy Technology Data Exchange (ETDEWEB)

Iwai, Yasunori, E-mail: iwai.yasunori@jaea.go.jp; Sato, Katsumi; Kawamura, Yoshinori; Yamanishi, Toshihiko

2013-10-15

Highlights: • Endurance of Nafion ion exchange membrane immersed in 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water was demonstrated. • Degradation of Nafion backbone structure by tritium beta was similar to that by gamma rays and electron beams at an equivalent dose. • Degradation directly by radiation was dominant at room temperature compared with that by reactions with radicals produced from water radiolysis. -- Abstract: The Nafion{sup ®} ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Endurance of Nafion ion exchange membrane immersed in 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water has been demonstrated at room temperature for up to 2 years under the Broader Approach Activities. The curves of percent elongation at break vs. dose and tensile strength vs. dose for the Nafion membranes immersed in tritiated water were well consistent with those for Nafion membranes irradiated to an equivalent dose with gamma rays and electron beams. This shows that the degradation of Nafion backbone structure by tritium beta is similar to that by gamma rays and electron beams. The results of ferric Fenton test indicated that the degradation directly by radiation was dominant at room temperature compared with that by reactions with radicals produced from water radiolysis. The curve of ion exchange capacity vs. dose for the Nafion membranes immersed in tritiated water was also well consistent with that for Nafion membranes irradiated to an equivalent dose with gamma rays and electron beams. These results showed irradiation tests with gamma rays and electron beams were alternative for predicting degradation of ion exchange membrane by tritium beta.

Study of ion exchange equilibrium and determination of heat of ion exchange by ion chromatography

International Nuclear Information System (INIS)

Liu Kailu; Yang Wenying

1996-01-01

Ion chromatography using pellicularia ion exchange resins and dilute solution can be devoted to the study of ion exchange thermodynamics and kinetics. Ion exchange equilibrium equation was obtained, and examined by the experiments. Based on ion exchange equilibrium, the influence of eluent concentration and resin capacity on adjusted retention volumes was examined. The effect of temperature on adjusted retention volumes was investigated and heats of ion exchange of seven anions were determined by ion chromatography. The interaction between anions and skeleton structure of resins were observed

Copper corrosion in irradiated environments: The influence of H2O2 on the electrochemistry of copper dissolution in HCl electrolyte

International Nuclear Information System (INIS)

Smyrl, W.H.; Bell, B.T.; Atanasoski, R.T.; Glass, R.S.

1986-12-01

The anodic dissolution of copper was examined in deaerated, 0.1 M HCl aqueous solution in the presence of H 2 O 2 . Concentrations of H 2 O 2 up to 0.2 M were studied at a rotating copper disk-platinum ring electrode. The open circuit potential (OCP) of copper was found to depend on both peroxide concentration and rotation rate. The OCP shifts towards more positive values with increasing H 2 O 2 concentration (C) and decreasing rotation rate. The current-voltage curves for anodic dissolution of copper were also influenced by the presence of peroxide. The curves recorded with the potential scanned in the positive direction showed the expected 60 mV slope, but the reverse scans showed significant departures. At a given potential scan rate, hysteresis was observed which was larger for higher H 2 O 2 concentrations, lower rotation rates, and more positive anodic potential limits. Monitoring the cuprous ions at the outer Pt ring revealed that there was a complex set of events taking place at the copper surface, including film formation and the appearance of cupric ions. 13 refs., 7 figs

CU(II): catalyzed hydrazine reduction of ferric nitrate

International Nuclear Information System (INIS)

Karraker, D.G.

1981-11-01

A method is described for producing ferrous nitrate solutions by the cupric ion-catalyzed reduction of ferric nitrate with hydrazine. The reaction is complete in about 1.5 hours at 40 0 C. Hydrazoic acid is also produced in substantial quantities as a reaction byproduct

Experiments on ion-acoustic rarefactive solitons in a multi-component plasma with negative ions

International Nuclear Information System (INIS)

Nakamura, Y.; Ferreira, J.L.; Ludwig, G.O.

1987-09-01

Ion-acoustic solitons in a three-component plasma which consists of electrons, positive and negative ions have been investigated experimentally. When the concentration of negative ions is smaller than a certain value, positive or compressive solitons are observed. At the critical concentration, a broad pulse of small but finite amplitude propagates without changing its shape. When the concentration is larger than this value, negative or rarefactive solitons are excited. The velocity and the width of these solitons are measured and compared with predictions of the Korteweg- de Vries equation which takes the negative ions and the ion temperature into consideration. Head-ion and over-taking collisions of the rarefactive solitons have been observed to show that the solitons are not affected by these collisions. (author) [pt

A hydrogen-ferric ion rebalance cell operating at low hydrogen concentrations for capacity restoration of iron-chromium redox flow batteries

Science.gov (United States)

Zeng, Y. K.; Zhao, T. S.; Zhou, X. L.; Zou, J.; Ren, Y. X.

2017-06-01

To eliminate the adverse impacts of hydrogen evolution on the capacity of iron-chromium redox flow batteries (ICRFBs) during the long-term operation and ensure the safe operation of the battery, a rebalance cell that reduces the excessive Fe(III) ions at the positive electrolyte by using the hydrogen evolved from the negative electrolyte is designed, fabricated and tested. The effects of the flow field, hydrogen concentration and H2/N2 mixture gas flow rate on the performance of the hydrogen-ferric ion rebalance cell have been investigated. Results show that: i) an interdigitated flow field based rebalance cell delivers higher limiting current densities than serpentine flow field based one does; ii) the hydrogen utilization can approach 100% at low hydrogen concentrations (≤5%); iii) the apparent exchange current density of hydrogen oxidation reaction in the rebalance cell is proportional to the square root of the hydrogen concentration at the hydrogen concentration from 1.3% to 50%; iv) a continuous rebalance process is demonstrated at the current density of 60 mA cm-2 and hydrogen concentration of 2.5%. Moreover, the cost analysis shows that the rebalance cell is just approximately 1% of an ICRFB system cost.

In situ Raman spectroscopic studies on concentration change of electrolyte salt in a lithium ion model battery with closely faced graphite composite and LiCoO2 composite electrodes by using an ultrafine microprobe

International Nuclear Information System (INIS)

Yamanaka, Toshiro; Nakagawa, Hiroe; Tsubouchi, Shigetaka; Domi, Yasuhiro; Doi, Takayuki; Abe, Takeshi; Ogumi, Zempachi

2017-01-01

The concentration of ions in the electrolyte solution in lithium ion batteries changes during operation, reflecting the resistance to ion migration and the positions of diffusion barriers. The change causes various negative effects on the performance of batteries. Thus, it is important to elucidate how the concentration changes during operation. In this work, the concentration change of ions in the electrolyte solution in deep narrow spaces in a realistic battery was studied by in situ ultrafine microprobe Raman spectroscopy. Graphite composite and LiCoO 2 composite electrodes, which are the most commonly used electrodes in practical batteries, were placed facing each other and their distance was set to 80 μm, which is close to the distance between electrodes in practical batteries. After repeated charge/discharge cycles, the concentration of ions increased and decreased greatly during charging and discharging, respectively. The maximum concentration was more than three-times higher than the minimum concentration. The rate of changes in concentration increased almost linearly with increase in current density. The results have important implications about concentration changes of ions occurring in practical batteries.

Adsorption site of ammonia on copper-exchanged Y-type zeolite under coexisting water vapor. Temperature-programed desorption and infrared adsorption spectra

Energy Technology Data Exchange (ETDEWEB)

Kasaoka, S.; Sasaoka, E.; Shiraga, T.; Ono, Y.

1978-03-01

Sodium Y zeolites were copper-exchanged with cupric nitrate in water, in aqueous ammonia, and in aqueous ammonia/ammonium chloride, and calcined at 500/sup 0/C. Temperature-programed desorption and IR spectroscopy showed three types of adsorption sites for 0.1-1.0% ammonia gas from nitrogen containing 0-12% water vapor: physisorption, adsorption as tetraamminocopper(II) on copper(II) sites (type 2 site), and adsorption as ammonium ion on hydroxyl sites (type 3 site). Adsorption on type 2 sites occurred only at high ammonia concentration; desorption occurred around 175/sup 0/C. Type 3 sites consisted of Cu(OH)/sup +/ and Al(OH)/sup +/, adsorbed ammonia from low concentrations, and at temperatures above 200/sup 0/C, were probably the active sites for the reduction of nitric oxide by ammonia.

[Ion channels that are sensitive to the extracellular concentration of protons: their structure, function, pharmacology and pathophysiology].

Science.gov (United States)

Mercado, F; Vega, R; Soto, E

Acid sensing ion channels (ASIC) members of the ENaC degenerine channel family, have been shown to participate in various sensorial pathways including nociception, also they have been shown to participate in synaptic transmission, learning and memory processes and in the physiopathology of the ischemic stroke. The proton concentration in the organism is strictly regulated by distinct buffer systems. Drastic changes of pH are generated only by pathological conditions as is the ischemia; however, some physiological processes may produce local changes in the extracellular pH. Recently, a new family of proton receptors known as ASIC has been cloned. These are ionic channels inactivated at physiological pH (7.4) and activated with a pH fall (increase in H+ concentration). ASICs are permeable to sodium ions and in a lesser degree to calcium ions, activation of these channels leads to an increase in cell excitability. The ASICs are distributed widely in the central and peripheral nervous system, and in specialized epithelia. In the past few years they have become a focus of interest due to its role in nociception, taste perception, long term potentation and the physiopathology of ischemic stroke. In this review we address the most relevant molecular, physiological and pharmacological aspects of the ASICs, its participation in some pathological process, and the perspectives of basic and clinic investigation in this arising research field.

Microfluidic paper-based biomolecule preconcentrator based on ion concentration polarization.

Science.gov (United States)

Han, Sung Il; Hwang, Kyo Seon; Kwak, Rhokyun; Lee, Jeong Hoon

2016-06-21

Microfluidic paper-based analytical devices (μPADs) for molecular detection have great potential in the field of point-of-care diagnostics. Currently, a critical problem being faced by μPADs is improving their detection sensitivity. Various preconcentration processes have been developed, but they still have complicated structures and fabrication processes to integrate into μPADs. To address this issue, we have developed a novel paper-based preconcentrator utilizing ion concentration polarization (ICP) with minimal addition on lateral-flow paper. The cation selective membrane (i.e., Nafion) is patterned on adhesive tape, and this tape is then attached to paper-based channels. When an electric field is applied across the Nafion, ICP is initiated to preconcentrate the biomolecules in the paper channel. Departing from previous paper-based preconcentrators, we maintain steady lateral fluid flow with the separated Nafion layer; as a result, fluorescent dyes and proteins (FITC-albumin and bovine serum albumin) are continuously delivered to the preconcentration zone, achieving high preconcentration performance up to 1000-fold. In addition, we demonstrate that the Nafion-patterned tape can be integrated with various geometries (multiplexed preconcentrator) and platforms (string and polymer microfluidic channel). This work would facilitate integration of various ICP devices, including preconcentrators, pH/concentration modulators, and micro mixers, with steady lateral flows in paper-based platforms.

Comparative Salt Stress Study on Intracellular Ion Concentration in Marine and Salt-adapted Freshwater Strains of Microalgae

Directory of Open Access Journals (Sweden)

Ahmad Farhad TALEBI

2013-08-01

Full Text Available Salinity imposes significant stresses in various living organisms including microalgae. High extracellular concentration of Na+ directly influences ionic balance inside the cell and subsequently the cellular activities. In the present study, the effect of such stress on growth and intracellular ions concentration (IIC of Dunaliella salina and Chlorella Spp. was investigated. IIC was analyzed using Ion chromatography technique. D. salina showed the highest degree of resistance to increase in salinity as little changes occurred both in IIC and in growth parameters. D. salina could maintain the balance of K+ inside the cell and eject the excess Na+ even at NaCl concentrations above 1M. Moreover, D. salina accumulated β-carotene in order to protect its photosynthetic apparatus. Among Chlorella species, C. vulgaris showed signs of adaptation to high content of salinity, though it is a fresh water species by nature. Moreover, the response shown by C. vulgaris to rise in salinity was even stronger than that of C. salina, which is presumably a salt-water resistant species. In fact, C. vulgaris could maintain intracellular K+ better than C. salina in response to increasing salinity, and as a result, it could survive at NaCl concentrations as high as 0.75 M. Marine strains such as D. salina well cope with the fluctuations in salinity through the existing adaptation mechanisms i.e. maintaining the K+/N+ balance inside the cell, K+ accumulation and Na+ ejection, accumulation of photosynthetic pigments like β-carotene.

Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

Science.gov (United States)

Xu, Pei; Capito, Marissa; Cath, Tzahi Y

2013-09-15

Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density. Copyright © 2013 Elsevier B.V. All rights reserved.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Due to the inherent anisotropy of the system, gold nanorods behave differently in comparison to their spherical counterparts. Reactivity of gold nanorods, in presence of cupric ions, was probed in an attempt to understand the chemistry of anisotropic particles. The reaction progresses through a series of intermediates.

Ion-acoustic nonlinear periodic waves in electron-positron-ion plasma

International Nuclear Information System (INIS)

Chawla, J. K.; Mishra, M. K.

2010-01-01

Ion-acoustic nonlinear periodic waves, namely, ion-acoustic cnoidal waves have been studied in electron-positron-ion plasma. Using reductive perturbation method and appropriate boundary condition for nonlinear periodic waves, the Korteweg-de Vries (KdV) equation is derived for the system. The cnoidal wave solution of the KdV equation is discussed in detail. It is found that the frequency of the cnoidal wave is a function of its amplitude. It is also found that the positron concentration modifies the properties of the ion-acoustic cnoidal waves. The existence regions for ion-acoustic cnoidal wave in the parameters space (p,σ), where p and σ are the positron concentration and temperature ratio of electron to positron, are discussed in detail. In the limiting case these ion-acoustic cnoidal waves reduce to the ion-acoustic soliton solutions. The effect of other parameters on the characteristics of the nonlinear periodic waves is also discussed.

Monitoring changes in membrane polarity, membrane integrity, and intracellular ion concentrations in Streptococcus pneumoniae using fluorescent dyes.

Science.gov (United States)

Clementi, Emily A; Marks, Laura R; Roche-Håkansson, Hazeline; Håkansson, Anders P

2014-02-17

Membrane depolarization and ion fluxes are events that have been studied extensively in biological systems due to their ability to profoundly impact cellular functions, including energetics and signal transductions. While both fluorescent and electrophysiological methods, including electrode usage and patch-clamping, have been well developed for measuring these events in eukaryotic cells, methodology for measuring similar events in microorganisms have proven more challenging to develop given their small size in combination with the more complex outer surface of bacteria shielding the membrane. During our studies of death-initiation in Streptococcus pneumoniae (pneumococcus), we wanted to elucidate the role of membrane events, including changes in polarity, integrity, and intracellular ion concentrations. Searching the literature, we found that very few studies exist. Other investigators had monitored radioisotope uptake or equilibrium to measure ion fluxes and membrane potential and a limited number of studies, mostly in Gram-negative organisms, had seen some success using carbocyanine or oxonol fluorescent dyes to measure membrane potential, or loading bacteria with cell-permeant acetoxymethyl (AM) ester versions of ion-sensitive fluorescent indicator dyes. We therefore established and optimized protocols for measuring membrane potential, rupture, and ion-transport in the Gram-positive organism S. pneumoniae. We developed protocols using the bis-oxonol dye DiBAC4(3) and the cell-impermeant dye propidium iodide to measure membrane depolarization and rupture, respectively, as well as methods to optimally load the pneumococci with the AM esters of the ratiometric dyes Fura-2, PBFI, and BCECF to detect changes in intracellular concentrations of Ca(2+), K(+), and H(+), respectively, using a fluorescence-detection plate reader. These protocols are the first of their kind for the pneumococcus and the majority of these dyes have not been used in any other bacterial

Impact of environmental regulations on control of copper ion concentration in the DIII-D cooling water system

International Nuclear Information System (INIS)

Gootgeld, A.M.

1993-10-01

Tokamaks and industrial users are faced with the task of maintaining closed-loop, low conductivity, low impurity, cooling water systems. Operating these systems concentrates the impurities in the water requiring subsequent disposal. Environmental regulations are making this increasingly difficult. This paper will discuss the solution to the problem of removing and disposing of copper ions in the DIII-D low conductivity water system. Since the commissioning of the Doublet facility, the quality of the water in the 3000 gpm system that cools the DIII-D vacuum vessel coils, power supplies and auxiliary heating components has been controlled with mixed-bed ion exchangers. Low ion levels, particularly copper, are required to operate this equipment. In early 1992, the company that leases and regenerates DIII-D ion exchangers said they no longer can accept these resin beds for regeneration due to the level of copper ion on the resin. This change in policy, a change that has been adopted throughout their industry, was necessary to assure that the Metropolitan Sewerage System of the City of San Diego stays in compliance with State of California regulations and EPA-mandated national pretreatment standards and regulations. A cost effective solution was implemented which utilizes a reverse osmosis filtration system with the ion exchangers for make-up water. Levels of copper ion disposed to the sewer are in compliance with government standards. These measures have thus far proved effective in maintaining low conductivity and overall good quality cooling water. Specifically, this paper discusses DIII-D deionized cooling water quality requirements and an affective means to meet these requirements in order to be in compliance with government regulations for copper ion disposal. The problems discussed, the alternatives considered and the approach taken would be readily applicable to any deionized cooling water system containing copper where EPA standards and regulations are mandated

Effect of low-oxygen-concentration layer on iron gettering capability of carbon-cluster ion-implanted Si wafer for CMOS image sensors

Science.gov (United States)

Onaka-Masada, Ayumi; Nakai, Toshiro; Okuyama, Ryosuke; Okuda, Hidehiko; Kadono, Takeshi; Hirose, Ryo; Koga, Yoshihiro; Kurita, Kazunari; Sueoka, Koji

2018-02-01

The effect of oxygen (O) concentration on the Fe gettering capability in a carbon-cluster (C3H5) ion-implanted region was investigated by comparing a Czochralski (CZ)-grown silicon substrate and an epitaxial growth layer. A high Fe gettering efficiency in a carbon-cluster ion-implanted epitaxial growth layer, which has a low oxygen region, was observed by deep-level transient spectroscopy (DLTS) and secondary ion mass spectroscopy (SIMS). It was demonstrated that the amount of gettered Fe in the epitaxial growth layer is approximately two times higher than that in the CZ-grown silicon substrate. Furthermore, by measuring the cathodeluminescence, the number of intrinsic point defects induced by carbon-cluster ion implantation was found to differ between the CZ-grown silicon substrate and the epitaxial growth layer. It is suggested that Fe gettering by carbon-cluster ion implantation comes through point defect clusters, and that O in the carbon-cluster ion-implanted region affects the formation of gettering sinks for Fe.

Determination of hexavalent chromium concentration in industrial waste incinerator stack gas by using a modified ion chromatography with post-column derivatization method.

Science.gov (United States)

Miyake, Yuichi; Tokumura, Masahiro; Iwazaki, Yuta; Wang, Qi; Amagai, Takashi; Horii, Yuichi; Otsuka, Hideyuki; Tanikawa, Noboru; Kobayashi, Takeshi; Oguchi, Masahiro

2017-06-16

An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to high concentrations of ionic compounds in the extract. However, by using gradient elution rather than isocratic elution we were able to fully resolve the Cr(VI) ion peak from the solvent peak without the need for diluting the extract, which would have reduced the minimum quantifiable level of the method. With this method, we were able to detect Cr(VI) in air at concentrations of 5.3ng/m 3 (assuming a sampling volume of 1m 3 and a final solution volume of 10mL). Recovery tests at three different concentrations of Cr(VI) (50, 250, 1000ng) were performed with or without fly ash; recovery rates at all the concentrations of Cr(VI), with or without fly ash, ranged from 68% to 110% (mean±relative standard deviation, 96%±11%), and there were no differences in recovery rates with respect to the presence or absence of fly ash. Finally, we used the developed method to determine the concentration of Cr(VI) in stack gases collected from eight industrial waste incinerators located in Japan. The concentration of Cr(VI) in the stack gases ranged from below the method quantification limit to 3100ng/m 3 . The highest concentrations of Cr(VI) detected in the stack gases were two to three orders of magnitude higher than that in ambient air in Japan. Copyright © 2017 Elsevier B.V. All rights reserved.

Ion mixing and numerical simulation of different ions produced in the ECR ion source

International Nuclear Information System (INIS)

Shirkov, G.D.

1996-01-01

This paper is to continue theoretical investigations and numerical simulations in the physics of ECR ion sources within the CERN program on heavy ion acceleration. The gas (ion) mixing effect in ECR sources is considered here. It is shown that the addition of light ions to the ECR plasma has three different mechanisms to improve highly charged ion production: the increase of confinement time and charge state of highly ions as the result of ion cooling; the concentration of highly charged ions in the central region of the source with high energy and density of electrons; the increase of electron production rate and density of plasma. The numerical simulations of lead ion production in the mixture with different light ions and different heavy and intermediate ions in the mixture with oxygen, are carried out to predict the principal ECR source possibilities for LHC applications. 18 refs., 23 refs

Adsorption efficiencies of calcium (II ion and iron (II ion on activated carbon obtained from pericarp of rubber fruit

Directory of Open Access Journals (Sweden)

Orawan Sirichote

2008-03-01

Full Text Available Determination of adsorption efficiencies of activated carbon from pericarp of rubber fruit for calcium (II ion and iron (II ion has been performed by flowing the solutions of these ions through a column of activated carbon. The weights of activated carbon in 500 mL buret column (diameter 3.2 cm for flowing calcium (II ion and iron (II ion solutions were 15 g and 10 g, respectively. The initial concentration of calcium ion was prepared to be about eight times more diluted than the true concentration found in the groundwater from the lower part of southern Thailand. Calcium (II ion concentrations were analysed by EDTA titration and its initial concentration was found to be 23.55 ppm. With a flow rate of 26 mL/min, the adsorption efficiency was 11.4 % with passed through volume 4.75 L. Iron (II ion concentrations were analysed by spectrophotometric method; its initial concentration was found to be 1.5565 ppm. At a flow rate of 22 mL/min, the adsorption efficiency was 0.42 % with passed through volume of 34.0 L.

Chiral recognition of proteins having L-histidine residues on the surface with lanthanide ion complex incorporated-molecularly imprinted fluorescent nanoparticles.

Science.gov (United States)

Uzun, Lokman; Uzek, Recep; Senel, Serap; Say, Ridvan; Denizli, Adil

2013-08-01

In this study, lanthanide ion complex incorporated molecularly imprinted fluorescent nanoparticles were synthesized. A combination of three novel approaches was applied for the purpose. First, lanthanide ions [Terbium(III)] were complexed with N-methacryloyl-L-histidine (MAH), polymerizable derivative of L-histidine amino acid, in order to incorporate the complex directly into the polymeric backbone. At the second stage, L-histidine molecules imprinted nanoparticles were utilized instead of whole protein imprinting in order to avoid whole drawbacks such as fragility, complexity, denaturation tendency, and conformation dependency. At the third stage following the first two steps mentioned above, imprinted L-histidine was coordinated with cupric ions [Cu(II)] to conduct the study under mild conditions. Then, molecularly imprinted fluorescent nanoparticles synthesized were used for L-histidine adsorption from aqueous solution to optimize conditions for adsorption and fluorimetric detection. Finally, usability of nanoparticles was investigated for chiral biorecognition using stereoisomer, D-histidine, racemic mixture, D,L-histidine, proteins with surface L-histidine residue, lysozyme, cytochrome C, or without ribonuclease A. The results revealed that the proposed polymerization strategy could make significant contribution to the solution of chronic problems of fluorescent component introduction into polymers. Additionally, the fluorescent nanoparticles reported here could be used for selective separation and fluorescent monitoring purposes. Copyright © 2013 Elsevier B.V. All rights reserved.

Metal ion transporters and homeostasis.

OpenAIRE

Nelson, N

1999-01-01

Transition metals are essential for many metabolic processes and their homeostasis is crucial for life. Aberrations in the cellular metal ion concentrations may lead to cell death and severe diseases. Metal ion transporters play a major role in maintaining the correct concentrations of the various metal ions in the different cellular compartments. Recent studies of yeast mutants revealed key elements in metal ion homeostasis, including novel transport systems. Several of the proteins discover...

Increased amounts of D-enantiomer dependent on alkaline concentration in the synthesis of L-[methyl-11C]methionine

International Nuclear Information System (INIS)

Ishiwata, Kiichi; Ido, Tatsuo; Vaalburg, W.

1988-01-01

The presence of D-enantiomer in L-[methyl- 11 C]methionine prepared from [ 11 C]CH 3 I and L-homocysteine thiolactone, was measured by high performance liquid chromatography using a reverse-phase column with an eluent containing L-proline and cupric acetate. The amount of D-enantiomer increased with concentration of NaOH used. The reaction time, 2-10 min, and the reaction temperature, 40 0 -80 0 C, have only minor effect on the formation of D-enantiomer. No significant difference was found for three different lots of L-homocysteine thiolactone. At the highest concentration investigated, 1.0 M NaOH in 50% aqueous acetone, the percentage of D-enantiomer was found to be 7.7%. With 0.025 M NaOH used only 2.1% was measured. When L-[methyl- 11 C]methionine was incubated in 1.0 M NaOH, no conversion of L- into D-enantiomer was observed. (author)

Effect of the minority concentration on ion cyclotron resonance heating in presence of the ITER-like wall in JET

Energy Technology Data Exchange (ETDEWEB)

Van Eester, D.; Lerche, E.; Crombé, K.; Jachmich, S. [LPP-ERM/KMS, Association Euratom-Belgian State, TEC Partner, Brussels (Belgium); Jacquet, P.; Graham, M.; Kiptily, V.; Matthews, G.; Mayoral, M.-L.; Mc Cormick, K.; Monakhov, I.; Noble, C.; Rimini, F.; Solano, E. R. [Euratom-CCFE Fusion Association, Culham Science Centre (United Kingdom); Bobkov, V.; Maggi, C.; Neu, R.; Pütterich, T. [MPI für Plasmaphysik Euratom Assoziation, Garching (Germany); Czarnecka, A. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Coenen, J. W. [IEK-4, EURATOM-FZJ, TEC Partner, Jülich (Germany); and others

2014-02-12

The most recent JET campaign has focused on characterizing operation with the 'ITER-like' wall. One of the questions that needed to be answered is whether the auxiliary heating methods do not lead to unacceptably high levels of impurity influx, preventing fusion-relevant operation. In view of its high single pass absorption, hydrogen minority fundamental cyclotron heating in a deuterium plasma was chosen as the reference wave heating scheme in the ion cyclotron domain of frequencies. The present paper discusses the plasma behavior as a function of the minority concentration X[H] in L-mode with up to 4MW of RF power. It was found that the tungsten concentration decreases by a factor of 4 when the minority concentration is increased from X[H] ≈ 5% to X[H] % 20% and that it remains at a similar level when X[H] is further increased to 30%; a monotonic decrease in Beryllium emission is simultaneously observed. The radiated power drops by a factor of 2 and reaches a minimum at X[H] ≈ 20%. It is discussed that poor single pass absorption at too high minority concentrations ultimately tailors the avoidance of the RF induced impurity influx. The edge density being different for different minority concentrations, it is argued that the impact ICRH has on the fate of heavy ions is not only a result of core (wave and transport) physics but also of edge dynamics and fueling.

Rapid colorimetric assay for gentamicin injection.

Science.gov (United States)

Tarbutton, P

1987-01-01

A rapid colorimetric method for determining gentamicin concentration in commercial preparations of gentamicin sulfate injection was developed. Methods currently available for measuring gentamicin concentration via its colored complex with cupric ions in alkaline solution were modified to reduce the time required for a single analysis. The alkaline copper tartrate (ACT) reagent solution was prepared such that each milliliter contained 100 mumol cupric sulfate, 210 mumol potassium sodium tartrate, and 1.25 mmol sodium hydroxide. The assay involves mixing 0.3 mL gentamicin sulfate injection 40 mg/mL (of gentamicin), 1.0 mL ACT reagent, and 0.7 mL water; the absorbance of the resulting solution at 560 nm was used to calculate the gentamicin concentration in the sample. For injections containing 10 mg/mL of gentamicin, the amount of the injection was increased to 0.5 mL and water decreased to 0.5 mL. The concentration of gentamicin in samples representing 11 lots of gentamicin sulfate injection 40 mg/mL and 8 lots of gentamicin sulfate injection 10 mg/mL was determined. The specificity, reproducibility, and accuracy of the assay were assessed. The colored complex was stable for at least two hours. Gentamicin concentration ranged from 93.7 to 108% and from 95 to 109% of the stated label value of the 40 mg/mL and the 10 mg/mL injections, respectively. No components of the preservative system present in the injections interfered with the assay. Since other aminoglycosides produced a colored complex, the assay is not specific for gentamicin. The assay was accurate and reproducible over the range of 4-20 mg of gentamicin. This rapid and accurate assay can be easily applied in the hospital pharmacy setting.

Analytical, Characterization and Stability Studies of Chemicals, Bulk Drugs and Drug Formulations

Science.gov (United States)

1997-10-01

assay, Report No. 933. 19. WR-242511AF, BM19356, 8-[(4-amino-l-methylbutyl)amino]-5-(1-hexyloxy)-6-methoxy- 4-methylquinoline DL- tartrate , assay...colorimetric protein assay based on complexation between bicinchoninic acid and cuprous ion, which results from reduction of cupric ion by a protein, was...amino-l-methylbutyl)amino]-5-(1-hexyloxy)-6-methoxy-4- methylquinoline DL- tartrate , shelf life, 3- and 6-month samplings, Report No. 738; 9-, 12-, 18

Ion species stratification within strong shocks in two-ion plasmas

Science.gov (United States)

Keenan, Brett D.; Simakov, Andrei N.; Taitano, William T.; Chacón, Luis

2018-03-01

Strong collisional shocks in multi-ion plasmas are featured in many environments, with Inertial Confinement Fusion (ICF) experiments being one prominent example. Recent work [Keenan et al., Phys. Rev. E 96, 053203 (2017)] answered in detail a number of outstanding questions concerning the kinetic structure of steady-state, planar plasma shocks, e.g., the shock width scaling by the Mach number, M. However, it did not discuss shock-driven ion-species stratification (e.g., relative concentration modification and temperature separation). These are important effects since many recent ICF experiments have evaded explanation by standard, single-fluid, radiation-hydrodynamic (rad-hydro) numerical simulations, and shock-driven fuel stratification likely contributes to this discrepancy. Employing the state-of-the-art Vlasov-Fokker-Planck code, iFP, along with multi-ion hydro simulations and semi-analytics, we quantify the ion stratification by planar shocks with the arbitrary Mach number and the relative species concentration for two-ion plasmas in terms of ion mass and charge ratios. In particular, for strong shocks, we find that the structure of the ion temperature separation has a nearly universal character across ion mass and charge ratios. Additionally, we find that the shock fronts are enriched with the lighter ion species and the enrichment scales as M4 for M ≫ 1.

Effect of oxide ion concentration on the electrochemical oxidation of carbon in molten LiCl

International Nuclear Information System (INIS)

Yun, J. W.; Choi, I. K.; Park, Y. S.; Kim, W. H.

2001-01-01

The continuous measurement of lithium oxide concentration was required in DOR (Direct Oxide Reduction) process, which converts spent nuclear fuel to metal form, for the reactivity monitor and effective control of the process. The concentration of lithium oxide was measured by the electrochemical method, which was based on the phenomenon that carbon atoms of glassy carbon electrode electrochemically react with oxygen ions of lithium oxide in molten LiCl medium. From the results of electrode polarization experiments, the trend of oxidation rate of carbon atoms was classified into two different regions, which were proportional and non-proportional ones, dependent on the amount of lithium oxide. Below about 2.5 wt % Li 2 O, as the carbon atom ionization rate was fast enough for reacting with diffusing lithium oxide to the surface of carbon electrode. In this concentration range, the oxidation rate of carbon atoms was controlled by the diffusion of lithium oxide, and the concentration of lithium oxide could be measured by electrochemical method. But, above 2.5 wt % Li 2 O, the oxidation rate of carbon atoms was controlled by the applied electrochemical potential, because the carbon atom ionization rate was suppressed by the huge amounts of diffusing Li 2 O. Above this concentration, the electrochemical method was not applicable to determine the concentration of lithium oxide

Natural variability in the surface ocean carbonate ion concentration

Science.gov (United States)

Lovenduski, N. S.; Long, M. C.; Lindsay, K.

2015-11-01

We investigate variability in the surface ocean carbonate ion concentration ([CO32-]) on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32-] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32-] in the tropical Pacific and at the boundaries between the subtropical and subpolar gyres in the Northern Hemisphere, and relatively low interannual variability in the centers of the subtropical gyres and in the Southern Ocean. Statistical analysis of modeled [CO32-] variance and autocorrelation suggests that significant anthropogenic trends in the saturation state of aragonite (Ωaragonite) are already or nearly detectable at the sustained, open-ocean time series sites, whereas several decades of observations are required to detect anthropogenic trends in Ωaragonite in the tropical Pacific, North Pacific, and North Atlantic. The detection timescale for anthropogenic trends in pH is shorter than that for Ωaragonite, due to smaller noise-to-signal ratios and lower autocorrelation in pH. In the tropical Pacific, the leading mode of surface [CO32-] variability is primarily driven by variations in the vertical advection of dissolved inorganic carbon (DIC) in association with El Niño-Southern Oscillation. In the North Pacific, surface [CO32-] variability is caused by circulation-driven variations in surface DIC and strongly correlated with the Pacific Decadal Oscillation, with peak spectral power at 20-30-year periods. North Atlantic [CO32-] variability is also driven by variations in surface DIC, and exhibits weak correlations with both the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. As the scientific community seeks to detect the anthropogenic influence on ocean carbonate chemistry, these results will aid the interpretation of trends

Ion temperature via laser scattering on ion Bernstein waves

International Nuclear Information System (INIS)

Wurden, G.A.; Ono, M.; Wong, K.L.

1981-10-01

Hydrogen ion temperature has been measured in a warm toroidal plasma with externally launched ion Bernstein waves detected by heterodyne CO 2 laser scattering. Radial scanning of the laser beam allows precise determination of k/sub perpendicular to/ for the finite ion Larmor radius wave (ω approx. less than or equal to 2Ω/sub i/). Knowledge of the magnetic field strength and ion concentration then give a radially resolved ion temperature from the dispersion relation. Probe measurements and Doppler broadening of ArII 4806A give excellent agreement

Detection of chloride ion concentration using chronopotentiometry

NARCIS (Netherlands)

Abbas, Yawar; Olthuis, Wouter; van den Berg, Albert

2013-01-01

In this paper, a novel approach is reported for the electrochemical measurement of chloride ions using chronopotentiometry. A current pulse is applied at the Ag/AgCl working electrode and the potential change is measured with respect to another identical Ag/AgCl electrode in the bulk electrolyte.

Behaviour of the pH adjustment, Ion exchange and concentrate precipitation stages in the acid leaching of uranium phosphate ores

International Nuclear Information System (INIS)

Estrada Aguilar, J.; Uriarte Hueda, A.

1962-01-01

The uranium recovery from acid leach solutions of uranium-phosphate ores has been studied. Relations have been found between the solution characteristics and the results obtained at different stages of the process. The following data can thus be predicted: solids to remove and uranium recovery in the pH adjustment stage, uranium capacity of the resin, more suitable eluating agent, elution velocity and uranium concentration in the eluate in the ion exchange stage, and composition of the concentrate produced by direct precipitation of the eluate in the concentrate precipitation stage. (Author) 8 refs

pH buffers for sea water media based on the total hydrogen ion concentration scale

Science.gov (United States)

Dickson, Andrew G.

1993-01-01

Published e.m.f. values measured using the cell ? where p° = 101.325 kPa, and BH + and B are the conjugate acid-base pairs of 2-aminopyridine, 2-amino-2-hydroxymethyl-1,3-propanediol (tris), tetrahydro-1,4-isoxazine (morpholine), and 2-amino-2-methyl-1, 3-propanediol (bis), have been re-evaluated to assign pH values based on the "total" hydrogen ion concentration scale to equimolal ( m =0.04 mol kg -1) buffer solutions based on these compounds. These pH values are consistent with the best available equilibrium constants for acid-base processes in sea water and such pH buffers can be used as pH calibration standards to measure accurate values for oceanic pH on the "total" hydrogen ion pH scale. In addition, the published e.m.f. results for these various amine bases have been used to calculate their respective acidity constants on this pH scale.

Determination of the total concentration and speciation of metal ions in river, estuarine and seawater samples.

Science.gov (United States)

Alberti, Giancarla; Biesuz, Raffaela; Pesavento, Maria

2008-12-01

Different natural water samples were investigated to determine the total concentration and the distribution of species for Cu(II), Pb(II), Al(III) and U(VI). The proposed method, named resin titration (RT), was developed in our laboratory to investigate the distribution of species for metal ions in complex matrices. It is a competition method, in which a complexing resin competes with natural ligands present in the sample to combine with the metal ions. In the present paper, river, estuarine and seawater samples, collected during a cruise in Adriatic Sea, were investigated. For each sample, two RTs were performed, using different complexing resins: the iminodiacetic Chelex 100 and the carboxylic Amberlite CG50. In this way, it was possible to detect different class of ligands. Satisfactory results have been obtained and are commented on critically. They were summarized by principal component analysis (PCA) and the correlations with physicochemical parameters allowed one to follow the evolution of the metals along the considered transect. It should be pointed out that, according to our findings, the ligands responsible for metal ions complexation are not the major components of the water system, since they form considerably weaker complexes.

The effect of different phosphate ion concentrations and ph of the phosphate buffer on lipase bioproduction by rhizopus oligosporus

International Nuclear Information System (INIS)

Haq, I.; Ali, S.; Awan, U.F.; Javed, W.; Mirza, S.

2005-01-01

In the present investigation, we report the effect of phosphate ion concentration and different ph of the phosphate buffer (as diluent) on lipase bioproduction by Rhizopus oligosporus. For this purpose, solid state fermentation was employed. Different agricultural by-products such as wheat bran, rice husk, almond meal, soybean meal and sunflower meal were used as substrate. The maximum lipase activity (72.60 U/g) was observed with the almond meal. Addition of phosphate ions (K/sub 2/HPO/sub 4/) influenced the lipase production. The ph of the phosphate buffer (7.0) was found to be effective for higher yield of lipase. (author)

Ion-ion interaction and energy transfer of 4+ transuranium ions in cerium tetrafluoride

International Nuclear Information System (INIS)

Liu, G.K.; Beitz, J.V.

1990-01-01

Dynamics of excited 5f electron states of the transuranium ions Cm 4+ and Bk 4+ in CeF 4 are compared. Based on time- and wavelength-resolved laser-induced fluorescence, excitation energy transfer processes have been probed. Depending on concentration and electronic energy level structure of the studied 4+ transuranium ion, the dominant energy transfer mechanisms were identified as cross relaxation, exciton-exciton annihilation, and trapping. Energy transfer rates derived from the fitting of the observed fluorescence decays to theoretical models, based on electric multipolar ion-ion interactions, are contrasted with prior studies of 4f states of 3+ lanthanide and 3d states of transition metal ions. 16 refs., 1 tab

Copper sulfate pentahydrate reduced epithelial cytotoxicity induced by lipopolysaccharide from enterogenic bacteria.

Science.gov (United States)

Feyzi, Adel; Delkhosh, Aref; Nasrabadi, Hamid Tayefi; Cheraghi, Omid; Khakpour, Mansour; Barekati-Mowahed, Mazyar; Soltani, Sina; Mohammadi, Seyede Momeneh; Kazemi, Masoumeh; Hassanpour, Mehdi; Rezabakhsh, Aysa; Maleki-Dizaji, Nasrin; Rahbarghazi, Reza; Namdarian, Reza

2017-05-01

The over usage of multiple antibiotics contributes to the emergence of a whole range of antibiotic-resistant strains of bacteria causing enterogenic infections in poultry science. Therefore, finding an appropriate alternative natural substance carrying an antibacterial capacity would be immensely beneficial. It has been previously discovered that the different types of cupric salts, especially copper sulfate pentahydrate (CuSO 4 ·5H 2 O), to carry a potent bactericidal capacity. We investigated the neutralizing effect of CuSO 4 ·5H 2 O (6.25μg/ml) on the reactive oxygen species generation, and expression of MyD88, an essential adaptor protein of Toll-like receptor, and NF-κB in three intestinal epithelial cell lines exposed to 50ng/ml lipopolysaccharide. In order to find the optimal cupric sulfate concentration without enteritis-inducing toxicity, broiler chickens were initially fed with water containing 0.4, 0.5, and 1mg/l during a period of 4days. After determination of appropriate dosage, two broiler chickens and turkey flocks with enteritis were fed with cupric compound for 4days. We found that cupric sulfate can lessen the cytotoxic effect of lipopolysaccharide by reducing the reactive oxygen species content (psulfate. The copper sulfate in doses lower than 0.4mg/ml expressed no cytotoxic effect on the liver, kidney, and the intestinal tract while a concentration of 0.5 and 1mg/ml contributed to a moderate to severe tissue injuries. Pearson Chi-Square analysis revealed the copper cation significantly diminished the rate of mortality during 4-day feeding of broiler chicken and turkey with enteritis (p=0.000). Thus, the results briefed above all confirm the potent anti-bactericidal feature of cupric sulfate during the course of enteritis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A Liquid Inorganic Electrolyte Showing an Unusually High Lithium Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide

Directory of Open Access Journals (Sweden)

Martin Winter

2013-08-01

Full Text Available We report on studies of an inorganic electrolyte: LiAlCl4 in liquid sulfur dioxide. Concentrated solutions show a very high conductivity when compared with typical electrolytes for lithium ion batteries that are based on organic solvents. Our investigations include conductivity measurements and measurements of transference numbers via nuclear magnetic resonance (NMR and by a classical direct method, Hittorf’s method. For the use of Hittorf’s method, it is necessary to measure the concentration of the electrolyte in a selected cell compartment before and after electrochemical polarization very precisely. This task was finally performed by potentiometric titration after hydrolysis of the salt. The Haven ratio was determined to estimate the association behavior of this very concentrated electrolyte solution. The measured unusually high transference number of the lithium cation of the studied most concentrated solution, a molten solvate LiAlCl4 × 1.6SO2, makes this electrolyte a promising alternative for lithium ion cells with high power ability.

Fully kinetic simulation of ion acoustic and dust-ion acoustic waves

International Nuclear Information System (INIS)

Hosseini Jenab, S. M.; Kourakis, I.; Abbasi, H.

2011-01-01

A series of numerical simulations is presented, based on a recurrence-free Vlasov kinetic model using kinetic phase point trajectories. All plasma components are modeled kinetically via a Vlasov evolution equation, then coupled through Poisson's equation. The dynamics of ion acoustic waves in an electron-ion and in a dusty (electron-ion-dust) plasma configuration are investigated, focusing on wave decay due to Landau damping and, in particular, on the parametric dependence of the damping rate on the dust concentration and on the electron-to-ion temperature ratio. In the absence of dust, the occurrence of damping was observed, as expected, and its dependence to the relative magnitude of the electron vs ion temperature(s) was investigated. When present, the dust component influences the charge balance, enabling dust-ion acoustic waves to survive Landau damping even in the extreme regime where T e ≅ T i . The Landau damping rate is shown to be minimized for a strong dust concentration or/and for a high value of the electron-to-ion temperature ratio. Our results confirm earlier theoretical considerations and contribute to the interpretation of experimental observations of dust-ion acoustic wave characteristics.

Ion channels versus ion pumps: the principal difference, in principle.

Science.gov (United States)

Gadsby, David C

2009-05-01

The incessant traffic of ions across cell membranes is controlled by two kinds of border guards: ion channels and ion pumps. Open channels let selected ions diffuse rapidly down electrical and concentration gradients, whereas ion pumps labour tirelessly to maintain the gradients by consuming energy to slowly move ions thermodynamically uphill. Because of the diametrically opposed tasks and the divergent speeds of channels and pumps, they have traditionally been viewed as completely different entities, as alike as chalk and cheese. But new structural and mechanistic information about both of these classes of molecular machines challenges this comfortable separation and forces its re-evaluation.

Effects of copper precursor concentration on the growth of cupric oxide nanorods for photoelectrode using a modified chemical bath deposition method

Energy Technology Data Exchange (ETDEWEB)

Oh, Hee-bong [Department of Nano Science and Engineering, High Safety Vehicle Core Technology Research Center, Inje University, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Ryu, Hyukhyun, E-mail: hhryu@inje.ac.kr [Department of Nano Science and Engineering, High Safety Vehicle Core Technology Research Center, Inje University, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Lee, Won-Jae [Department of Materials and Components Engineering, Dong-Eui University, Busan 614-714 (Korea, Republic of)

2015-01-25

Highlights: • CuO nanorod photoelectrodes were prepared by modified CBD method. • The CuO nanorods were vertically grown with a high growth rate. • Effects of precursor concentration on the CuO nanorods were investigated. - Abstract: In this study, vertically aligned CuO nanorods were grown using a modified chemical bath deposition method with various copper precursor concentrations. The morphological, structural, optical and photoelectrochemical properties of the synthesized CuO samples were characterized using a field-emission scanning electron microscope, an X-ray diffractometer, a UV–visible spectrometer and a three-electrode potentiostat, respectively. The growth rates of the samples varied from 4.3 to 500 nm/min with the varying precursor concentrations. The vertically well-grown CuO nanorods exhibited one-dimensional growth along the (0 2 0) plane. We obtained a maximum photocurrent density of −1.05 mA/cm{sup 2} at −0.6 V (vs. SCE) from the CuO nanorod photoelectrode grown using the 10 mM copper precursor concentration.

Modeling the ion transfer and polarization of ion exchange membranes in bioelectrochemical systems.

Science.gov (United States)

Harnisch, Falk; Warmbier, Robert; Schneider, Ralf; Schröder, Uwe

2009-06-01

An explicit numerical model for the charge balancing ion transfer across monopolar ion exchange membranes under conditions of bioelectrochemical systems is presented. Diffusion and migration equations have been solved according to the Nernst-Planck Equation and the resulting ion concentrations, pH values and the resistance values of the membrane for different conditions were computed. The modeling results underline the principle limitations of the application of ion exchange membranes in biological fuel cells and electrolyzers, caused by the inherent occurrence of a pH-gradient between anode and cathode compartment, and an increased ohmic membrane resistance at decreasing electrolyte concentrations. Finally, the physical and numerical limitations of the model are discussed.

Developing on-site paper colorimetric monitoring technique for quick evaluating copper ion concentration in mineral wastewater

Science.gov (United States)

Liu, Guokun; Peng, Jingji; Zheng, Hong; Yuan, Dongxing

2018-05-01

With the reinforce of the copper mining, the on-site monitoring of the accompanied effluent discharge is highly demanded for the emergency response to minimize the negative effect of the effluent on the surrounding ecosystem. On the basis of the specific interaction between Cu2+ and L-Cysteine (L-Cys), which was modified on gold nanoparticles (Au NPs), and the aggregation dependent surface plasmon resonance (SPR) of Au NPs, we developed an easy-on-going paper colorimetric method for the quick evaluating the copper ion concentration in the waste water excreted from the copper mine. The color change of L-Cys modified Au NPs (L-Cys-Au NPs)immobilized on a filter paper was very sensitive to the Cu2+ concentration and free of interference from other metal ions typically in waste water. The proposed paper colorimetry has the LOD of 0.09 mg/L and the linear range of 0.1-10 mg/L, respectively, with the RSD (n = 5) was 6.6% for 1 mg/L Cu2+ and 3.5% for 5 mg/L Cu2+. The quantitative analysis results for the mineral wastewater is in good agreement the China National Environmental Protection Standards HJ485-2009, which indicates the current method could be developed to the on-site detection technique for the emergency response in monitoring Cu2+ in industrial wastewater or polluted water.

Energy transfer and quenching processes of excited uranyl ion and lanthanide ions in solutions

International Nuclear Information System (INIS)

Yamamura, Tomoo; Tomiyasu, Hiroshi

1995-01-01

Deactivation processes of photoexcited uranyl ion by various lanthanide ions in aqueous solution were studied. Each lanthanide ions show different interaction with excited uranyl ion depending on its lowest excited energy level, the number of 4f electrons and the acid concentration of the solution. (author)

Biological activities of Umbilicaria crustulosa (Ach. frey acetone extract

Directory of Open Access Journals (Sweden)

Zlatanović Ivana

2017-01-01

Full Text Available This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC method. Additionally, the total phenolic compounds (TPC and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteria were determined. Acetone extract of U. crustulosa at concentration of 1 and 2 μg mL-1 decreased a frequency of micronuclei (MN by 10.8 and 16.8 %, respectively, acting more or slightly less than the synthetic protector amifostine (AMF, WR-2721, 11.4 %, at concentration of 1 μg mL-1. The tested extract did not inhibit cholinesterase activity nor did it exhibit activity toward the examined bacteria. The extract reduced the concentration of DPPH and ABTS radicals by 88.7 and 96.2 %, respectively. Values for total reducing power (TRP and cupric reducing capacity (CUPRAC were 0.6197±0.0166 μg ascorbic acid equivalents (AAE per mg of dry extract, and 19.7641±1.6546 μg trolox equivalents (TE per mg of dry extract, respectively. The total phenol content was 350.4188 ±14.587 μg gallic acid equivalents (GAE per mg of dry extract. The results of the present study showed that U. crustulosa acetone extract is a promising candidate for in vivo experiments considering its antioxidant activity and protective effect on human lymphocytes. [Projekat Ministarstva nauke Republike Srbije, br. 172047

Transition of ion-acoustic perturbations in multicomponent plasma with negative ions

International Nuclear Information System (INIS)

Sharma, Sumita Kumari; Devi, Kavita; Adhikary, Nirab Chandra; Bailung, Heremba

2008-01-01

Evolution of ion-acoustic compressive (positive) and rarefactive (negative) perturbations in a multicomponent plasma with negative ions has been investigated in a double plasma device. Transition of compressive solitons in electron-positive ion plasma, into a dispersing train of oscillations in a multicomponent plasma, when the negative ion concentration r exceeds a critical value r c , has been observed. On the other hand, an initial rarefactive perturbation initially evolves into a dispersing train of oscillations in electron-positive ion plasma and transforms into rarefactive solitons in a multicomponent plasma when the negative ion concentration is higher than the critical value. The Mach velocity and width of the compressive and rarefactive solitons are measured. The compressive solitons in the range 0 c and the rarefactive solitons in the range r>r c have different characteristics than the Korteweg-de Vries (KdV) solitons at r=0 and modified KdV solitons at r=r c . A nonlinear differential equation having two terms to account for the lower and higher order nonlinearity has been used to explain the observed results

Removal method of fluorescent dyes as pretreatment for measurement of major ion concentrations and hydrogen and oxygen isotopic ratios

International Nuclear Information System (INIS)

Nakata, Kotaro; Hasegawa, Takuma; Kashiwaya, Koki; Kodama, Hiroki; Miyajima, Tohru

2011-01-01

The major ion concentration and isotope ratio of hydrogen and oxygen can provide important information for migration of groundwater. Sometimes, quantitative estimation of these chemical and isotopic characteristics of solution is necessary for groundwater containing fluorescent dyes, which are used in drilling borehole and tracer experiments. However, sometimes correct estimation is disturbed by dyes and they become a cause of troubles for measurement equipments. Thus development of method to remove dyes is required so that the characteristics of groundwater can be estimated without the negative effect of dyes on measurement or equipments. In this study, removal of four representative dyes (Uranin, Eosin, Naphthalenesulfonic acid sodium(NAP) and Amino G acid potassium salt (AG)) was investigated. Uranin and Eosin were found to be removed by non-ionic synthetic resin: HP2MG. 99.99% of the dyes were removed from initial solutions containing dyes with 10 mg/L after contact with resin, while the contact had little effect on ion concentrations and oxygen and hydrogen isotope ratios. Thus the chemical and isotopic characteristics of groundwater samples containing Uranin and Eosin can be obtained by using the HP2MG resin. On the other hand, the NAP and AG were found to be difficult to remove by the HP2MG resin but they were able to be removed by anion exchange resin (Dowex 1x8). Though contact of solution with Dowex 1x8 did not affect cation concentrations and hydrogen and oxygen isotope ratios, anion concentrations were changed by the contact. Therefore the Dowex 1x8 is only applicable to estimation of the cation concentrations and isotope ratio of hydrogen and oxygen. When both anion and cation concentrations from the samples were necessary, Uranin or Eosin were recommended as a tracer in drilling or tracer experiments. (author)

Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions.

Science.gov (United States)

Uralcan, Betul; Aksay, Ilhan A; Debenedetti, Pablo G; Limmer, David T

2016-07-07

We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid in agreement with recent experimental observations. The nonmonotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. Mirroring the capacitance, we find that the characteristic decay length of charge density correlations away from the electrode is also nonmonotonic. The correlation length first decreases with ion concentration as a result of better electrostatic screening but increases with ion concentration as a result of enhanced steric interactions. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such capacitive behavior is expected to be generic.

Inferring Magnetospheric Heavy Ion Density using EMIC Waves

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun-Hwa; Johnson, Jay R.; Kim, Hyomin; Lee, Dong-Hun

2014-05-01

We present a method to infer heavy ion concentration ratios from EMIC wave observations that result from ionion hybrid (IIH) resonance. A key feature of the ion-ion hybrid resonance is the concentration of wave energy in a field-aligned resonant mode that exhibits linear polarization. This mode converted wave is localized at the location where the frequency of a compressional wave driver matches the IIH resonance condition, which depends sensitively on the heavy ion concentration. This dependence makes it possible to estimate the heavy ion concentration ratio. In this letter, we evaluate the absorption coefficients at the IIH resonance at Earth's geosynchronous orbit for variable concentrations of He+ and field-aligned wave numbers using a dipole magnetic field. Although wave absorption occurs for a wide range of heavy ion concentrations, it only occurs for a limited range of field-aligned wave numbers such that the IIH resonance frequency is close to, but not exactly the same as the crossover frequency. Using the wave absorption and observed EMIC waves from GOES-12 satellite, we demonstrate how this technique can be used to estimate that the He+ concentration is around 4% near L = 6.6.

High-Thermal- and Air-Stability Cathode Material with Concentration-Gradient Buffer for Li-Ion Batteries.

Science.gov (United States)

Shi, Ji-Lei; Qi, Ran; Zhang, Xu-Dong; Wang, Peng-Fei; Fu, Wei-Gui; Yin, Ya-Xia; Xu, Jian; Wan, Li-Jun; Guo, Yu-Guo

2017-12-13

Delivery of high capacity with high thermal and air stability is a great challenge in the development of Ni-rich layered cathodes for commercialized Li-ion batteries (LIBs). Herein we present a surface concentration-gradient spherical particle with varying elemental composition from the outer end LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM) to the inner end LiNi 0.8 Co 0.15 Al 0.05 O 2 (NCA). This cathode material with the merit of NCM concentration-gradient protective buffer and the inner NCA core shows high capacity retention of 99.8% after 200 cycles at 0.5 C. Furthermore, this cathode material exhibits much improved thermal and air stability compared with bare NCA. These results provide new insights into the structural design of high-performance cathodes with high energy density, long life span, and storage stability materials for LIBs in the future.

Ion measurements in premixed methane-oxygen flames

KAUST Repository

Alquaity, Awad

2014-07-25

Ions are formed as a result of chemi-ionization processes in combustion systems. Recently, there has been an increasing interest in understanding flame ion chemistry due to the possible application of external electric fields to reduce emissions and improve combustion efficiency by active control of combustion process. In order to predict the effect of external electric fields on combustion plasma, it is critical to gain a good understanding of the flame ion chemistry. In this work, a Molecular Beam Mass Spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane-oxygen-argon burner-stabilized flames. Lean, stoichiometric and rich flames at atmospheric pressure are used to study the dependence of ion chemistry on equivalence ratio of premixed flames. The relative ion concentration profiles are compared qualitatively with previous methane-oxygen studies and show good agreement. The relative ion concentration data obtained in the present study can be used to validate and improve ion chemistry models for methane-oxygen flames.

To measure ammonia and the ammonium-ion in high concentrations with sensitrodes; Messreihen mit Ammoniak- und Ammonium-Sensitroden in ungewoehnlich hohen Konzentrationsbereichen

Energy Technology Data Exchange (ETDEWEB)

Brosche, P. [DBI-EWI GmbH, Freiberg (Germany)

1996-08-01

Ammonia up to 8 Mol/kg and the ammonium-ion up to 5 Mol/kg were investigated by sensitrodes. Sensitrodes of different manufacturers, the influence of different salts, the temperature (25 and 50 C) and ammonia in mixture with the ammonium-ion were assessed in respect of the result for measuring. The functional correlation between the pH-value and the logarithmus for the ratio of ammonium-ion to ammonia in respect of the equation from Henderson and Hasselbalch was examined. The given concentration for ammonia respectively the ammonium-ion was compared with the calculated concentration of the calibration curve. The investigated sensitrodes may be installed in the manufacturing of ammonium salts in mixture with ammonia as measuring and controlling unit. (orig.) [Deutsch] Ammoniak bis 8 mol/kg und das Ammoniumion bis 5 mol/kg wurden mittels Sensitroden untersucht. Bewertet wurden Sensitroden verschiedener Hersteller, der Einfluss von Salzen, der Temperatur (25 und 50 C) und Ammoniak im Gemisch mit dem Ammoniumion auf das Messergebnis. Der funktionale Zusammenhang zwischen dem pH-Wert und dem Logarithmus des Verhaeltnisses von Ammoniumion und Ammoniak entsprechend der Gleichung von Henderson und Hasselbalch wurde untersucht. Die eingegebenen Konzentrationen an Ammoniak bzw. des Ammoniumions wurden mit den aus den Kalibrierungskurven errechneten Konzentrationen verglichen. Die untersuchten Sensitroden koennen in der Produktion von Ammoniumsalzen im Gemisch mit Ammoniak als Mess- und Steuergeraet eingesetzt werden. (orig.)

Factors that influence an elemental depth concentration profile

International Nuclear Information System (INIS)

McHugh, J.A.

1975-01-01

The use of secondary ion mass spectrometry in concentration profiling is discussed. Two classes of factors that influence an elemental concentration profile are instrumental effects and ion-matrix effects. Instrumental factors that must be considered are: (1) uniformity of the primary ion current density, (2) constancy of the primary ion current, (3) redeposition, (4) memory, (5) primary ion beam tailing and the nonfocused component, (6) chemical purity of the primary ion beam, and (7) residual gas impurities. Factors which can be classified as ion matrix effects are: (1) the mean escape depth of secondary ions, (2) recoil implantation, (3) molecular ion interferences, (4) primary ion beam induced diffusion of matrix species, (5) nonuniform sputter removal of matrix layers, and (6) implanted primary ion chemical and lattice damage effects

Natural variability in the surface ocean carbonate ion concentration

Directory of Open Access Journals (Sweden)

N. S. Lovenduski

2015-11-01

Full Text Available We investigate variability in the surface ocean carbonate ion concentration ([CO32−] on the basis of a~long control simulation with an Earth System Model. The simulation is run with a prescribed, pre-industrial atmospheric CO2 concentration for 1000 years, permitting investigation of natural [CO32−] variability on interannual to multi-decadal timescales. We find high interannual variability in surface [CO32−] in the tropical Pacific and at the boundaries between the subtropical and subpolar gyres in the Northern Hemisphere, and relatively low interannual variability in the centers of the subtropical gyres and in the Southern Ocean. Statistical analysis of modeled [CO32−] variance and autocorrelation suggests that significant anthropogenic trends in the saturation state of aragonite (Ωaragonite are already or nearly detectable at the sustained, open-ocean time series sites, whereas several decades of observations are required to detect anthropogenic trends in Ωaragonite in the tropical Pacific, North Pacific, and North Atlantic. The detection timescale for anthropogenic trends in pH is shorter than that for Ωaragonite, due to smaller noise-to-signal ratios and lower autocorrelation in pH. In the tropical Pacific, the leading mode of surface [CO32−] variability is primarily driven by variations in the vertical advection of dissolved inorganic carbon (DIC in association with El Niño–Southern Oscillation. In the North Pacific, surface [CO32−] variability is caused by circulation-driven variations in surface DIC and strongly correlated with the Pacific Decadal Oscillation, with peak spectral power at 20–30-year periods. North Atlantic [CO32−] variability is also driven by variations in surface DIC, and exhibits weak correlations with both the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. As the scientific community seeks to detect the anthropogenic influence on ocean carbonate chemistry, these results

Influence of nonelectrostatic ion-ion interactions on double-layer capacitance

Science.gov (United States)

Zhao, Hui

2012-11-01

Recently a Poisson-Helmholtz-Boltzmann (PHB) model [Bohinc , Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.85.031130 85, 031130 (2012)] was developed by accounting for solvent-mediated nonelectrostatic ion-ion interactions. Nonelectrostatic interactions are described by a Yukawa-like pair potential. In the present work, we modify the PHB model by adding steric effects (finite ion size) into the free energy to derive governing equations. The modified PHB model is capable of capturing both ion specificity and ion crowding. This modified model is then employed to study the capacitance of the double layer. More specifically, we focus on the influence of nonelectrostatic ion-ion interactions on charging a double layer near a flat surface in the presence of steric effects. We numerically compute the differential capacitance as a function of the voltage under various conditions. At small voltages and low salt concentrations (dilute solution), we find out that the predictions from the modified PHB model are the same as those from the classical Poisson-Boltzmann theory, indicating that nonelectrostatic ion-ion interactions and steric effects are negligible. At moderate voltages, nonelectrostatic ion-ion interactions play an important role in determining the differential capacitance. Generally speaking, nonelectrostatic interactions decrease the capacitance because of additional nonelectrostatic repulsion among excess counterions inside the double layer. However, increasing the voltage gradually favors steric effects, which induce a condensed layer with crowding of counterions near the electrode. Accordingly, the predictions from the modified PHB model collapse onto those computed by the modified Poisson-Boltzmann theory considering steric effects alone. Finally, theoretical predictions are compared and favorably agree with experimental data, in particular, in concentrated solutions, leading one to conclude that the modified PHB model adequately predicts the diffuse

Response of thermal ions to electromagnetic ion cyclotron waves

Science.gov (United States)

Anderson, B. J.; Fuselier, S. A.

1994-01-01

Electromagnetic ion cyclotron waves generated by 10 - 50 keV protons in the Earth's equatorial magnetosphere will interact with the ambient low-energy ions also found in this region. We examine H(+) and He(+) distribution functions from approx. equals 1 to 160 eV using the Hot Plasma Composition Experiment instrument on AMPTE/CCE to investigate the thermal ion response to the waves. A total of 48 intervals were chosen on the basis of electromagnetic ion cyclotron (EMIC) wave activity: 24 with prevalent EMIC waves and 24 with no EMIC waves observed on the orbit. There is a close correlation between EMIC waves and perpendicular heated ion distributions. For protons the perpendicular temperature increase is modest, about 5 eV, and is always observed at 90 deg pitch angles. This is consistent with a nonresonant interaction near the equator. By contrast, He(+) temperatures during EMIC wave events averaged 35 eV and sometimes exceeded 100 eV, indicating stronger interaction with the waves. Furthermore, heated He(+) ions have X-type distributions with maximum fluxes occurring at pitch angles intermediate between field-aligned and perpendicular directions. The X-type He(+) distributions are consistent with a gyroresonant interaction off the equator. The concentration of He(+) relative to H(+) is found to correlate with EMIC wave activity, but it is suggested that the preferential heating of He(+) accounts for the apparent increase in relative He(+) concentration by increasing the proportion of He(+) detected by the ion instrument.

Immobilised metal-ion affinity chromatography purification of histidine-tagged recombinant proteins : a wash step with a low concentration of EDTA

NARCIS (Netherlands)

Westra, DF; Welling, GW; Koedijk, DGAM; Scheffer, AJ; The, TH; Welling-Wester, S

2001-01-01

Immobilised metal-ion affinity chromatography (IMAC) is widely used for the purification of recombinant proteins in which a poly-histidine tag is introduced. However, other proteins may also bind to IMAC columns. We describe the use of a washing buffer with a low concentration of EDTA (0.5 mM) for

Interactions of chlorphenesin and divalent metal ions with phosphodiesterase.

Science.gov (United States)

Edelson, J; McMullen, J P

1976-09-01

Chlorphenesin inhibition of the hydrolysis of cyclic AMP by guinea-pig lung phosphodiesterase was reversed by the addition of exogenous magnesium ions. Chlorphenesin and theophylline inhibition of this enzyme was shown to be noncompetitive when the substrate concentration was low. Kinetic studies of the inhibition of beef heart phosphodiesterase by chlorphenesin and theophylline indicated that the substrate concentration was a factor in determining whether inhibition was competitive or noncompetitive. Calcium, cobalt and copper ions were inhibitory to guinea-pig lung phosphodiesterase. The inhibition due to chlorphenesin was partially reversed by low (40 mM or less) concentrations of barium ions; high concentrations of barium ions, or manganese ions, were inhibitory. The concentration of the divalent cation did not affect the type of inhibition that was observed.

Si-nanoparticle synthesis using ion implantation and MeV ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Chulapakorn, T.; Wolff, M.; Primetzhofer, D.; Possnert, G. [Uppsala University, Department of Physics and Astronomy, P.O. Box 516, 751 20 Uppsala (Sweden); Sychugov, I.; Suvanam, S.S.; Linnros, J. [Royal Institute of Technology, School of Information and Communication Technology, P.O. Box Electrum 229, 164 40 Kista (Sweden); Hallen, A. [Uppsala University, Department of Physics and Astronomy, P.O. Box 516, 751 20 Uppsala (Sweden); Royal Institute of Technology, School of Information and Communication Technology, P.O. Box Electrum 229, 164 40 Kista (Sweden)

2015-12-15

A dielectric matrix with embedded Si-nanoparticles may show strong luminescence depending on nanoparticles size, surface properties, Si-excess concentration and matrix type. Ion implantation of Si ions with energies of a few tens to hundreds of keV in a SiO{sub 2} matrix followed by thermal annealing was identified as a powerful method to form such nanoparticles. The aim of the present work is to optimize the synthesis of Si-nanoparticles produced by ion implantation in SiO{sub 2} by employing MeV ion irradiation as an additional annealing process. The luminescence properties are measured by spectrally resolved photoluminescence including PL lifetime measurement, while X-ray reflectometry, atomic force microscopy and ion beam analysis are used to characterize the nanoparticle formation process. The results show that the samples implanted at 20%-Si excess atomic concentration display the highest luminescence and that irradiation of 36 MeV {sup 127}I ions affects the luminosity in terms of wavelength and intensity. It is also demonstrated that the nanoparticle luminescence lifetime decreases as a function of irradiation fluence. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Alternative solidification techniques for radioactive ion exchange resins and liquid concentrates

International Nuclear Information System (INIS)

Thegerstroem, C.

1980-01-01

Methods, that are used or are under development for solidification of radioactive ion exchange resins or liquid concentrates, utilize normally cement, bitumen or some polymere as matrix material. This report contains a review and a description of these solidification processes and their products, especially of relatively new techniques that are under development in different countries. It is possible that solidification in thermosetting resins will be more used in the future, especially when product quality requirements are high (for instance when solidifying medium level resins) or when special waste categories has to be solidified. However it is not probable that thermosetting resins will be extensively used in a broad application as matrix material. In that case the methods are to complicated and expensive compared to, for instance, solidification in concrete. Systems for incorporation in polyesteremulsions (Dow-process) have a potential as they are quite simple and can accept a large variation of liquid wastes. Some methods in an early stage of development (for instance Inert Carrier Radwaste Process) will have to be tested in active application before they can be further evaluated. (author)

Zero-Gap Alkaline Water Electrolysis Using Ion-Solvating Polymer Electrolyte Membranes at Reduced KOH Concentrations

DEFF Research Database (Denmark)

Kraglund, Mikkel Rykær; Aili, David; Jankova Atanasova, Katja

2016-01-01

Membranes based on poly(2,2'-(m-phenylene)-5,5-bibenzimidazole) (m-PBI) can dissolve large amounts of aqueous KOH to give electrolyte systems with ion conductivity in a practically useful range. The conductivity of the membrane strongly depends on the concentration of the aqueous KOH phase......, reaching about 10-1 S cm-1 or higher in 15-25 wt% KOH. Herein, m-PBI membranes are systematically characterized with respect to performance and short-term stability as electrolyte in a zero-gap alkaline water electrolyzer at different KOH concentrations. Using plain uncatalyzed nickel foam electrodes......, the cell based on m-PBI outperforms the cell based on the commercially available state-of-the-art diaphragm and reaches a current density of 1500 mA cm-2 at 2.4 V in 20 wt% KOH at 80°C. The cell performance remained stable during two days of operation, though post analysis of the membrane using size...

Ion-acoustic cnoidal wave and associated non-linear ion flux in dusty plasma

Energy Technology Data Exchange (ETDEWEB)

Jain, S. L. [Poornima Group of Institution, Sitapura, Jaipur 302022 (India); Tiwari, R. S. [Regional College for Education, Research and Technology, Jaipur 302022 (India); Mishra, M. K. [Department of Physics, University of Rajasthan, Jaipur 302004 (India)

2012-10-15

Using reductive perturbation method with appropriate boundary conditions, coupled evolution equations for first and second order potentials are derived for ion-acoustic waves in a collisionless, un-magnetized plasma consisting of hot isothermal electrons, cold ions, and massive mobile charged dust grains. The boundary conditions give rise to renormalization term, which enable us to eliminate secular contribution in higher order terms. Determining the non secular solution of these coupled equations, expressions for wave phase velocity and averaged non-linear ion flux associated with ion-acoustic cnoidal wave are obtained. Variation of the wave phase velocity and averaged non-linear ion flux as a function of modulus (k{sup 2}) dependent wave amplitude are numerically examined for different values of dust concentration, charge on dust grains, and mass ratio of dust grains with plasma ions. It is found that for a given amplitude, the presence of positively (negatively) charged dust grains in plasma decreases (increases) the wave phase velocity. This behavior is more pronounced with increase in dust concentrations or increase in charge on dust grains or decrease in mass ratio of dust grains. The averaged non-linear ion flux associated with wave is positive (negative) for negatively (positively) charged dust grains in the plasma and increases (decreases) with modulus (k{sup 2}) dependent wave amplitude. For given amplitude, it increases (decreases) as dust concentration or charge of negatively (positively) charged dust grains increases in the plasma.

Decreased Sensitivity to Changes in the Concentration of Metal Ions as the Basis for the Hyperactivity of DtxR(E175K)

Energy Technology Data Exchange (ETDEWEB)

D’Aquino, J. Alejandro; Denninger, Andrew R.; Moulin, Aaron G.; D’Aquino, Katharine E.; Ringe, Dagmar; (Harvard-Med); (Brandeis)

2010-01-12

The metal-ion-activated diphtheria toxin repressor (DtxR) is responsible for the regulation of virulence and other genes in Corynebacterium diphtheriae. A single point mutation in DtxR, DtxR(E175K), causes this mutant repressor to have a hyperactive phenotype. Mice infected with Mycobacterium tuberculosis transformed with plasmids carrying this mutant gene show reduced signs of the tuberculosis infection. Corynebacterial DtxR is able to complement mycobacterial IdeR and vice versa. To date, an explanation for the hyperactivity of DtxR(E175K) has remained elusive. In an attempt to address this issue, we have solved the first crystal structure of DtxR(E175K) and characterized this mutant using circular dichroism, isothermal titration calorimetry, and other biochemical techniques. The results show that although DtxR(E175K) and the wild type have similar secondary structures, DtxR(E175K) gains additional thermostability upon activation with metal ions, which may lead to this mutant requiring a lower concentration of metal ions to reach the same levels of thermostability as the wild-type protein. The E175K mutation causes binding site 1 to retain metal ion bound at all times, which can only be removed by incubation with an ion chelator. The crystal structure of DtxR(E175K) shows an empty binding site 2 without evidence of oxidation of Cys102. The association constant for this low-affinity binding site of DtxR(E175K) obtained from calorimetric titration with Ni(II) is K{sub a} = 7.6 {+-} 0.5 x 10{sup 4}, which is very similar to the reported value for the wild-type repressor, K{sub a} = 6.3 x 10{sup 4}. Both the wild type and DtxR(E175K) require the same amount of metal ion to produce a shift in the electrophoretic mobility shift assay, but unlike the wild type, DtxR(E175K) binding to its cognate DNA [tox promoter-operator (toxPO)] does not require metal-ion supplementation in the running buffer. In the timescale of these experiments, the Mn(II)-DtxR(E175K)-toxPO complex

Determining fluoride ions in ammonium desulfurization slurry using an ion selective electrode method

Science.gov (United States)

Luo, Zhengwei; Guo, Mulin; Chen, Huihui; Lian, Zhouyang; Wei, Wuji

2018-02-01

Determining fluoride ions in ammonia desulphurization slurry using a fluoride ion selective electrode (ISE) is investigated. The influence of pH was studied and the appropriate total ionic strength adjustment buffer and its dosage were optimized. The impact of Fe3+ concentration on the detection results was analyzed under preferable conditions, and the error analysis of the ISE method’s accuracy and precision for measuring fluoride ion concentration in the range of 0.5-2000 mg/L was conducted. The quantitative recovery of F- in ammonium sulfate slurry was assessed. The results showed that when pH ranged from 5.5˜6 and the Fe3+ concentration was less than 750 mg/L, the accuracy and precision test results with quantitative recovery rates of 92.0%-104.2% were obtained.

Adsorption on mixtures of ion exchangers

International Nuclear Information System (INIS)

Triolo, R.; Lietzke, M.H.

1979-01-01

A theoretical study has been made of adsorption on mixtures of ion exchangers. The effect of variables such as the concentration of the ion being adsorbed, the concentration of the supporting electrolyte, loading, the values of the capacities and equilibrium constants for the various exchange processes, and the fraction of each adsorber in the mixture on the observed distribution coefficient has been investigated. A computer program has been written to facilitate the calculation of distribution coefficients for the adsorption of an ion on a given mixture of ion exchangers under a specified set of conditions

Entry of Nd+3 ions into the LiYF4 matrix and determination of Nd+3 concentration by the nondestructing spectrophotometric method

International Nuclear Information System (INIS)

Tkachuk, A.M.; Poletimova, A.V.; Petrova, M.A.; Egorov, V.Yu.; Korolev, N.E.

1991-01-01

Entering of Nd 3+ ions into LiYF 4 lattice was investigation. Nondestructive spectrophotometric method for determining activator concentration in the crystal was developed. It enables to determine both the average integral concentration in the active element. Absorption cross sections were determined for a series of reference lines λ i with the lowest polarization degree. Values of β(λ i ) coefficients, enabling to determine the average neodymium concentration in the sample, are presented. Coefficient of neodymium entering into LiYF 4 lattice was determined: K nd =0.31+-0.02

Last Glacial to Holocene changes of deep and intermediate water carbonate ion concentrations in the Southern Ocean: constraints from foraminiferal Boron/Calcium ratios

OpenAIRE

Kersten, Franziska

2013-01-01

In this thesis, the first records of intermediate and deep water carbonate ion concentrations in the South Pacific were generated in order to study carbon cycle dynamics throughout the past 30,000 years. Benthic foraminiferal B/Ca, an indicator of past seawater carbonate ion saturation is the main paleoceanographic proxy that was used in this study. Down-core proxy studies carried out within the scope of this thesis were used to address currently unresolved questions about the origin, mechani...

Chiral ligand exchange high-speed countercurrent chromatography: mechanism, application and comparison with conventional liquid chromatography in enantioseparation of aromatic α-hydroxyl acids

Science.gov (United States)

Tong, Shengqiang; Shen, Mangmang; Cheng, Dongping; Ito, Yoichiro; Yan, Jizhong

2014-01-01

This work concentrates on the separation mechanism and application of chiral ligand exchange high-speed countercurrent chromatography (HSCCC) in enantioseparations, and comparison with traditional chiral ligand exchange high performance liquid chromatography (HPLC). The enantioseparation of ten aromatic α-hydroxyl acids were performed by these two chromatographic methods. Results showed that five of the racemates were successfully enantioseparated by HSCCC while only three of the racemates could be enantioseparated by HPLC using a suitable chiral ligand mobile phase additive. For HSCCC, the two-phase solvent system was composed of butanol-water (1:1, v/v), to which N-n-dodecyl-L-proline was added in the organic phase as chiral ligand and cupric acetate was added in the aqueous phase as a transition metal ion. Various operation parameters in HSCCC were optimized by enantioselective liquid-liquid extraction. Based on the results of the present studies the separation mechanism for HSCCC was proposed. For HPLC, the optimized mobile phase composed of aqueous solution containing 6 mmol L−1 L-phenylalanine and 3 mmol L−1 cupric sulfate and methanol was used for enantioseparation. Among three ligands tested on a conventional reverse stationary phase column, only one was found to be effective. In the present studies HSCCC presented unique advantages due to its high versatility of two-phase solvent systems and it could be used as an alternative method for enantioseparations. PMID:25087742

Electron-ion collisions

International Nuclear Information System (INIS)

Crandall, D.H.

1982-01-01

This discussion concentrates on basic physics aspects of inelastic processes of excitation, ionization, and recombination that occur during electron-ion collisions. Except for cases of illustration along isoelectronic sequences, only multicharged (at least +2) ions will be specifically discussed with some emphasis of unique physics aspects associated with ionic charge. The material presented will be discussed from a primarily experimental viewpoint with most attention to electron-ion interacting beams experiments

Trace-element concentrations and water-soluble ions in size-segregated dust-borne and soil samples in Sistan, southeast Iran

Science.gov (United States)

Behrooz, Reza Dahmardeh; Esmaili-Sari, Abbas; Bahramifar, Nader; Kaskaoutis, D. G.; Saeb, Keivan; Rajaei, Fatemeh

2017-04-01

This study analyzes the chemical composition (water-soluble ions and trace elements) of the total suspended particles (TSP) and particulate matter less than 10 and 2.5 μm (PM10 and PM2.5) in the Sistan basin, southeast Iran during the dusty and windy period June - October 2014. Extreme TSP, PM10 and PM2.5 concentrations, means of 1624.8, 433.4 and 320.8 μgm-3, respectively, were recorded in the Zabol sampling site, while the examined water-soluble ions and trace metals constitute small fractions (∼4.1%-17.7%) of the particulate masses. Intense winds on the dust-storm days result in weathering of soil crust and deflation of evaporate minerals from the dried Hamoun lake beds in the Sistan basin. The soil samples are rich in Ca2+, SO42-, Na+ and Cl- revealing the existence of non-sea salts, as well as in Al, Fe and Mg, while the similarity in the chemical composition between soil and airborne samples indicates that the dust events over Sistan are local in origin. In contrast, low concentrations of secondary ions (i.e., nitrate) and heavy metals (i.e., Pb, Cr, Ni, Cu) indicate less anthropogenic and industrial emissions. Enrichment Factor analysis for TSP, PM10 and PM2.5 reveals that the anthropogenic sources contribute a substantial amount in the heavy metals rather than soil crust, while Al, Fe, Sn, Mg are mostly of crustal origin. The results provide essential knowledge in atmospheric chemistry over Sistan and in establishing mitigation strategies for air pollution control.

Determination of zirconium by fluoride ion selective electrode

International Nuclear Information System (INIS)

Mahanty, B.N.; Sonar, V.R.; Gaikwad, R.; Raul, S.; Das, D.K.; Prakash, A.; Afzal, Md.; Panakkal, J.P.

2010-01-01

Full text: Zirconium is used in a wide range of applications including nuclear clad, catalytic converters, surgical appliances, metallurgical furnaces, superconductors, ceramics, lamp filaments, anti corrosive alloys and photographical purposes. Irradiation testing of U-Zr and U-Pu-Zr fuel pins has also demonstrated their feasibility as fuel in liquid metal reactors. Different methods that are employed for the determination of zirconium are spectrophotometry, potentiometry, neutron activation analysis and mass spectrometry. Ion-selective electrode (ISE), selective to zirconium ion has been studied for the direct potentiometric measurements of zirconium ions in various samples. In the present work, an indirect method has been employed for the determination of zirconium in zirconium nitrate sample using fluoride ion selective electrode. This method is based on the addition of known excess amount of fluoride ion to react with the zirconium ion to produce zirconium tetra fluoride at about pH 2-3, followed by determination of residual fluoride ion selective electrode. The residual fluoride ion concentrations were determined from the electrode potential data using calibration plot. Subsequently, zirconium ion concentrations were determined from the concentration of consumed fluoride ions. A precision of about 2% (RSD) with the mean recovery of more than 94% has been achieved for the determination of zirconium at the concentration of 4.40 X 10 -3 moles lit -1

Intense ion beam generator

International Nuclear Information System (INIS)

Humphries, S. Jr.; Sudan, R.N.

1977-01-01

Methods and apparatus for producing intense megavolt ion beams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation

Influences of hydrological regime on heavy metal and salt ion concentrations in intertidal sediment from Chongming Dongtan, Changjiang River estuary, China

Science.gov (United States)

Zhao, Jiale; Gao, Xiaojiang; Yang, Jin

2017-11-01

The tidal flat along the Changjiang (Yangtze) River estuary has long been reclaimed for the agricultural purposes, with the prevailing hydrological conditions during such pedogenic transformations being of great importance to their successful development. In this study, samples of surface sediment from Chongming Dongtan, situated at the mouth of the Changjiang River estuary, were collected and analyzed in order to understand how hydrological management can influence the concentrations of heavy metals and salt ions in pore water, and chemical fractionation of heavy metals during the reclamation process. We performed a series of experiments that simulated three different hydrological regimes: permanent flooding (R1), alternative five-day periods of wetting and drying (R2), continuous field capacity (R3). Our results exhibited good Pearson correlations coefficients between heavy metals and salt ions in the pore water for both R1 and R2. In particular, the concentrations of salt ions in the pore water decreased in all three regimes, but showed the biggest decline in R2. With this R2 experiment, the periodic concentration patterns in the pore water varied for Fe and Mn, but not for Cr, Cu, Pb and Zn. Neither the fractionation of Ni nor the residual fractions of any metals changed significantly in any regime. In R1, the reducible fractions of heavy metals (Cr, Cu, Zn and Pb) in the sediment decreased, while the acid extractable fractions increased. In R2, the acid extractable and the reducible fractions of Cr, Cu, Zn and Pb both decreased, as did the oxidizable fraction of Cu. These data suggest that an alternating hydrological regime can reduce both salinity and the availability of heavy metals in sediments.

Silver-Ion-Exchanged Nanostructured Zeolite X as Antibacterial Agent with Superior Ion Release Kinetics and Efficacy against Methicillin-Resistant Staphylococcus aureus.

Science.gov (United States)

Chen, Shaojiang; Popovich, John; Iannuzo, Natalie; Haydel, Shelley E; Seo, Dong-Kyun

2017-11-15

As antibiotic resistance continues to be a major public health problem, antimicrobial alternatives have become critically important. Nanostructured zeolites have been considered as an ideal host for improving popular antimicrobial silver-ion-exchanged zeolites, because with very short diffusion path lengths they offer advantages in ion diffusion and release over their conventional microsized zeolite counterparts. Herein, comprehensive studies are reported on materials characteristics, silver-ion release kinetics, and antibacterial properties of silver-ion-exchanged nanostructured zeolite X with comparisons to conventional microsized silver-ion-exchanged zeolite (∼2 μm) as a reference. The nanostructured zeolites are submicrometer-sized aggregates (100-700 nm) made up of primary zeolite particles with an average primary particle size of 24 nm. The silver-ion-exchanged nanostructured zeolite released twice the concentration of silver ions at a rate approximately three times faster than the reference. The material exhibited rapid antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) with minimum inhibitory concentration (MIC) values ranging from 4 to 16 μg/mL after 24 h exposure in various growth media and a minimum bactericidal concentration (MBC; >99.9% population reduction) of 1 μg/mL after 2 h in water. While high concentrations of silver-ion-exchanged nanostructured zeolite X were ineffective at reducing MRSA biofilm cell viability, efficacy increased at lower concentrations. In consideration of potential medical applications, cytotoxicity of the silver-ion-exchanged nanostructured zeolite X was also investigated. After 4 days of incubation, significant reduction in eukaryotic cell viability was observed only at concentrations 4-16-fold greater than the 24 h MIC, indicating low cytotoxicity of the material. Our results establish silver-ion-exchanged nanostructured zeolites as an effective antibacterial material against dangerous

Advances in corrosion testing of metals in contact with treated wood

Science.gov (United States)

Samuel Zelinka; D.S. Stone

2010-01-01

A January 2004 change in the regulation of wood preservatives used in the U.S.has increased the use of newer wood preservatives, such as alkaline copper quaternary (ACQ) and copper azole (CuAz). These preservatives contain high amounts of cupric ions, which may be reduced to copper metal at the expense of less noble steel and galvanized fasteners in the wood....

Modeling the Lithium Ion Battery

Science.gov (United States)

Summerfield, John

2013-01-01

The lithium ion battery will be a reliable electrical resource for many years to come. A simple model of the lithium ions motion due to changes in concentration and voltage is presented. The battery chosen has LiCoO[subscript 2] as the cathode, LiPF[subscript 6] as the electrolyte, and LiC[subscript 6] as the anode. The concentration gradient and…

[Effects of metal-catalyzed oxidation on the formation of advanced oxidation protein products].

Science.gov (United States)

Li, Li; Peng, Ai; Zhu, Kai-Yuan; Yu, Hong; Ll, Xin-Hua; Li, Chang-Bin

2008-03-11

To explore the relationship between metal-catalyzed oxidation (MCO) and the formation of advanced oxidation protein products (AOPPs). Specimens of human serum albumin (HSA) and pooled plasma were collected from 3 healthy volunteers and 4 uremia patients were divided into 3 groups: Group A incubated with copper sulfate solution of the concentrations of 0, 0.2, or 0.5 mmol/L, Group B, incubated with hydrogen peroxide 2 mmol/L, and Group C, incubated with copper sulfate 0.2 or 0.5 mmol/L plus hydrogen peroxide 2 mmol/L. 30 min and 24 h later the AOPP level was determined by ultraviolet visible spectrophotometry. High-performance liquid chromatography (HPLC) was used to observe the fragmentation effect on plasma proteins. Ninhydrin method was used to examine the protein fragments. The scavenging capacity of hydroxyl radical by macromolecules was measured so as to estimate the extent of damage for proteins induced by MCO. (1) The AOPP level of the HSA and plasma specimens of the uremia patients increased along with the increase of cupric ion concentration in a dose-dependent manner, especially in the presence of hydrogen peroxide (P < 0.05). (2) Aggregation of proteins was almost negligible in all groups, however, HPLC showed that cupric ion with or without hydrogen peroxide increased the fragments in the HAS specimens (with a relative molecular mass of 5000) and uremia patients' plasma proteins (with the molecular mass 7000). (3) The plasma AOPP level of the healthy volunteers was 68.2 micromol/L +/- 2.4 micromol/L, significantly lower than that of the uremia patients (158.5 micromol/L +/- 8.2 micromol/L). (4) The scavenging ability to clear hydroxyl radical by plasma proteins of the healthy volunteers was 1.38 -9.03 times as higher than that of the uremia patients. MCO contributes to the formation of AOPPs mainly through its fragmentation effect to proteins.

Changes in the Concentration of Ions in Saliva and Dental Plaque after Application of CPP-ACP with and without Fluoride among 6-9 Year Old Children.

Science.gov (United States)

Poureslami, H; Hoseinifar, Ra; Khazaeli, P; Hoseinifar, Re; Sharifi, H; Poureslami, P

2017-03-01

The casein phospho peptide-amorphous calcium phosphate with or without fluoride (CPP-ACPF and CPP-ACP respectively) are of considerably new materials which are highly recommended for prevention of dental caries. However, there is a shortage in literature on how they affect the ion concentration of saliva or dental plaque. The aim of this study was to evaluate the concentration of calcium, phosphate and fluoride in the plaque and saliva of children with Early Childhood Caries (ECC) after applying the CPP-ACP paste in comparison with the use of CPP-ACPF paste. One ml of un-stimulated saliva of 25 preschool children was collected and then 1 mg of the plaque sample was collected from the buccal surfaces of the two first primary molars on the upper jaw. CPP-ACP as well as CPP-ACPF pastes were applied on the tooth surfaces in two separate steps. In steps, plaque and saliva sampling was performed after 60 minutes. The amount of calcium ions was measured by Atomic Absorption Device and the amount of phosphate and fluoride ions was measured by Ion Chromatography instrument. Data were analyzed using Repeated Measurements ANOVA at a p Application of both CPP-ACPF and CPP-ACP significantly increased the concentration of calcium, phosphate, and fluoride in both saliva and dental plaque. Moreover, significantly higher salivary fluoride concentration was seen after application of CPP-ACPF compared to CPP-ACP. No other significant difference was observed between these two materials. CPP-ACPF can be more useful than CPP-ACP in protecting the primary teeth against caries process, especially when there is poor hygiene.

Proton concentrations can be a major contributor to the modification of osteoclast and osteoblast differentiation, working independently of extracellular bicarbonate ions.

Science.gov (United States)

Kato, Kohtaro; Matsushita, Misao

2014-01-01

We established a system to separately analyze the role of protons and bicarbonate ions in vitro in which the pH of the medium was controlled by HEPES at various concentrations of sodium bicarbonate (NaHCO3) in the absence of carbon dioxide (CO2). Using this system, we demonstrated that acidosis promoted osteoclast formation independently of extracellular NaHCO3 in a short-term culture. Protons and bicarbonate ions acted on osteoclast differentiation with opposite effects, the former positively and the latter negatively. The HEPES-based system maintained pH in the absence of extracellular NaHCO3 without CO2. Therefore, we could demonstrate that osteoblast differentiation was promoted at higher pH in a long-term culture system without NaHCO3 in which ALP activity and nodule mineralization were enhanced. This finding indicates that protons negatively control osteoblast differentiation independently of extracellular bicarbonate ions. However, the difference in the concentration of NaHCO3 did not have any influence on nodule mineralization. The opposite effects of protons, the promotion of osteoclast formation and the inhibition of osteoblast differentiation, were suppressed in the presence of 5 mM N-acetyl cysteine, a reagent activating the scavenging of reactive oxygen species (ROS), implying that ROS act on both systems, the promotion of large osteoclast formation and the deterioration of osteoblast formation under acidosis.

External excitation of ion cyclotron drift waves in a two-ion species plasma

International Nuclear Information System (INIS)

Kando, M.; Ikezawa, S.; Sugai, H.

1984-01-01

Ion cyclotron drift waves propagating across a density gradient and a magnetic field have been excited externally in a two-ion species plasma, with its concentration ratio controlled. The measured dispersion relations agree with the theoretical predictions. (author)

Removal of Cobalt Ions by Precipitate Foam Flotation

Energy Technology Data Exchange (ETDEWEB)

Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-09-30

Simulated waste liquid containing 50 ppm cobalt ion was tested by precipitate flotation using a sodium lauryl sulfate as a collector. The effects of initial cobalt ion concentration, pH, surfactant concentration, flotation time, gas flow rate and foreign ions on removal efficiency of cobalt ion were studied. Pretreatment of the waste liquid with 35% H{sub 2}O{sub 2} prior to precipitate flotation made shift of optimal flotation pH from the strong alkalinity to weak alkaline range and made a favorable flotation of cobalt ion in wide range of pH. For the result of this experiment, 99.8% removal efficiency was obtained on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, flotation time 30 min. The simulate ion was formed to be the most harmful ion against removal of cobalt by precipitate flotation of the species which were tested. The presence of 0.1 M of SO{sub 4}{sup 2-} ion decreased removal efficiency of cobalt to 90% while the cobalt were almost entirely removed in the absence of sulfate ion. (author). 11 refs., 8 figs.

A novel ion-exclusion chromatography-mass spectrometry method to measure concentrations and cycling rates of carbohydrates and amino sugars in freshwaters.

Science.gov (United States)

Horňák, Karel; Pernthaler, Jakob

2014-10-24

The concentrations of free neutral carbohydrates and amino sugars were determined in freshwater samples of distinct matrix complexity, including meso-, eu- and dystrophic lakes and ponds, using high-performance ion-exclusion chromatography (HPIEC) coupled to mass spectrometry (MS). In contrast to other methods, our approach allowed the quantification of free neutral carbohydrates and amino sugars at low nM concentrations without derivatization, de-salting or pre-concentration. New sample preparation procedures were applied prior to injection employing syringe and hollow fiber filtration. Analytes were separated on a strong cation exchange resin under 100% aqueous conditions using 0.1% formic acid as a mobile phase. To minimize background noise in MS, analytes were detected in a multiple reaction monitoring scan mode with double ion filtering. Detection limits of carbohydrates and amino sugars ranged between 0.2 and 2nM at a signal-to-noise ratio >5. Error ranged between 1 and 12% at 0.5-500nM levels. Using a stable isotope dilution approach, both the utilization and recycling of glucose in Lake Zurich was observed. In contrast, N-acetyl-glucosamine was equally rapidly consumed but there was no visible de novo production. The simple and rapid sample preparation makes our protocol suitable for routine analyses of organic compounds in freshwater samples. Application of stable isotope tracers along with accurate measures of carbohydrate and amino sugar concentrations enables novel insights into the compound in situ dynamics. Copyright © 2014 Elsevier B.V. All rights reserved.

Possibilities for direct optical observation of negative hydrogen ions in ion beam plasma sources via Rayleigh or Thomson scattering

International Nuclear Information System (INIS)

Burgess, D.D.

1985-01-01

The possibilities of applying optical scattering techniques to the determination of H - concentrations in plasma sources relevant to negative ion beam generation are considered. Rayleigh scattering measurements for incident wavelengths just below the H - photoionization limit appear to be only just feasible experimentally. A more promising possibility is observation of the modification in a plasma containing negative ions of the collective ion-feature in Thomson scattering. Numerical predictions of the effects of H - concentration on the spectral distribution of the ion-feature are presented. (author)

Stoichiometric carbon nitride synthesized by ion beam sputtering and post nitrogen ion implantation

International Nuclear Information System (INIS)

Valizadeh, R.; Colligon, J.S.; Katardiev, I.V.; Faunce, C.A.; Donnelly, S.E.

1998-01-01

Full text: Carbon nitride films have been deposited on Si (100) by ion beam sputtering a vitreous graphite target with nitrogen and argon ions with and without concurrent N2 ion bombardment at room temperature. The sputtering beam energy was 1000 eV and the assisted beam energy was 300 eV with ion / atom arrival ratio ranging from 0.5 to 5. The carbon nitride films were deposited both as single layer directly on silicon substrate and as multilayer between two layers of stoichiometric amorphous silicon nitride and polycrystalline titanium nitride. The deposited films were implanted ex-situ with 30 keV nitrogen ions with various doses ranging from 1E17 to 4E17 ions.cm -2 and 2 GeV xenon ion with a dose of 1E12 ions.cm -2 . The nitrogen concentration of the films was measured with Rutherford Backscattering (RBS), Secondary Neutral Mass Spectrometry (SNMS) and Parallel Electron Energy Loss Spectroscopy (PEELS). The nitrogen concentration for as deposited sample was 34 at% and stoichiometric carbon nitride C 3 N 4 was achieved by post nitrogen implantation of the multi-layered films. Post bombardment of single layer carbon nitride films lead to reduction in the total nitrogen concentration. Carbon K edge structure obtained from PEELS analysis suggested that the amorphous C 3 N 4 matrix was predominantly sp 2 bonded. This was confirmed by Fourier Transforrn Infra-Red Spectroscopy (FTIR) analysis of the single CN layer which showed the nitrogen was mostly bonded with carbon in nitrile (C≡N) and imine (C=N) groups. The microstructure of the film was determined by Transmission Electron Microscopy (TEM) which indicated that the films were amorphous

The Use of Copper- 64 in the Investigation of Reaction Mechanisms of Enzymes, Particularly as Related to Food Processing; Emploi de Cuivre-64 dans l'Etude des Mecanismes de Reaction des Enzymes, Notamment en Ce Qui Concerne la Preparation des Denrees Alimentaires; ПРИМЕНЕНИЕ МЕДИ-64 ДЛЯ ИССЛЕДОВАНИЯ МЕХАНИЗМОВ ФЕРМЕНТАТИВНЫХ РЕАКЦИЙ, СВЯЗАННЫХ С ОБРАБОТКОЙ ПИЛИ; Empleo de Cobre-64 en el Estudio de los Mecanismos de Reacciones Enzima Ticas de Interes para la Elaboracion de Alimentos

Energy Technology Data Exchange (ETDEWEB)

Arthur, Jr., J. C.; McLemore, T. A. [Southern Regional Research Laboratory, New Orleans, LA (United States)

1963-03-15

The oxidative enzymes of plant tissues are often dormant or only slightly active during the resting state, becoming active on the injury of the tissue or on separation from the tissue. During food processing this results in an acceleration of the oxidation of the natural substrates and polymerization of the products, which discolour the tissue. Copper oxidases are the principal enzymes involved in catalysing these reactions. The activation of the enzyme also leads to its reaction inactivation. One of the causes of the phenomenon of reaction inactivation is the decrease in the effective concentration of the enzyme, probably by the removal or binding of its metal prosthetic group copper. By using copper- 64, in vitro, it was shown that, in a resting solution, cupric ion can complex and/or exchange with the copper of the enzyme and that, in oxidizing solutions, an additional amount of cupric ion can be complexed. Cu-o-quinone- type complexes have higher formation constants than Cu-p-quinone- type complexes. The amount of cupric ion complexed was decreased, if the ion was added in an oxidizing solution after the initiation of polymerization of the o-quinone type reaction products. The kinetics of the exchange and complexing processes for cupric ions with enzyme and reaction products are discussed mathematically. (author) [French] Les enzymes oxydants des tissus vegetaux sont souvent inactifs ou tres peu actifs a l'etat de repos et ne deviennent actifs qu'en cas de lesion du tissu ou lorsqu'ils sont separes de celui-ci. Lors de la preparation des denrees alimentaires, ce phenomene a pour effet d'accelerer l'oxydation des substrats naturels et de polymeriser les produits, ce qui donne lieu a une decoloration du tissu. Les oxydases de cuivre sont les principaux enzymes qui interviennent comme catalyseurs dans ces reactions. L'activation de l'enzyme entraine en outre une inhibition de la reaction qu'il subit. Une des causes de ce phenomene est la diminution de la

Spectroscopic and redox properties of curium and californium ions in concentrated aqueous carbonate-bicarbonate media

International Nuclear Information System (INIS)

Hobart, D.E.; Varlashkin, P.G.; Samhoun, K.; Haire, R.G.; Peterson, J.R.

1983-01-01

Multimilligram quantities of trivalent curium-248 and californium-249 were investigated by absorption spectroscopy, cyclic voltammetry, and bulk solution electrolysis in concentrated aqueous carbonate-bicarbonate solution. Actinide concentrations between 10 -4 and 10 -2 M were studied in 2 M sodium carbonate and 5.5 M potassium carbonate solutions at pH values from 8 to 14. The solution absorption spectra of Cm(III) and Cf(III) in carbonate media are presented for the first time and compared to literature spectra of these species in noncomplexing aqueous solution. It was anticipated that carbonate complexation of the actinide ions could provide a sufficient negative shift in the formal potentials of the M(IV)/M(III) couples of Cm and Cf to permit the generation and stabilization of their tetravalent states in aqueous carbonate-bicarbonate medium. No conclusive evidence was found in the present work to indicate the existence of any higher oxidation states of curium or californium in carbonate solution. Some possible reasons for our inability to generate and detect oxidized species of curium and californium in this medium are discussed

Effect of electronic spatial extents (ESE) of ions on overpotential of lithium ion capacitors

International Nuclear Information System (INIS)

Xu, Fan; Lee, Chung ho; Koo, Chong Min; Jung, Cheolsoo

2014-01-01

Highlights: •Electronic spatial extent (ESE) of ion characterizes its electron density volume. •The ESE of ion proposes to assess overpotential of nanoporous capacitor. •Anion with low ESE shows low overpotential of the capacitor. •The ESE is more realistic to assess overpotential than conductivity or ion size. -- Abstract: The electronic spatial extent (ESE) of ions was defined as a major concept for assessing the cause of overpotential in the charging and discharging processes of a nanoporous activated carbon (AC) electrode. The performance degradation of AC/Li half-cells was caused by the overpotential, which was in discord with the electrolyte conductivity and ion size. Compared to the overpotential with the salt concentration, the AC/Li half-cell with a high concentration had a smaller overpotential, and its discharge patterns were similar to the curves obtained from the half-cells with a smaller ESE of BF 4 − ion. The ESE is a more realistic solution for determining the overpotential of the nanoporous capacitor, such as supercapacitor and Li ion capacitor, because its capacity is dependent on the electron density at the electric double layer of the capacitor electrode

BWR pipe crack remedies evaluation

International Nuclear Information System (INIS)

Shack, W.J.; Kassner, T.F.; Maiya, P.S.; Park, J.Y.; Ruther, W.; Kuzay, T.; Rybicki, E.F.; Stonesifer, R.B.

1988-01-01

Piping in light-water-reactor power systems has been affected by several types of environmental degradation. This paper presents results from studies of (1) stress corrosion crack growth in fracture mechanics specimens of modified Type 347 SS and Type 304/308L SS weld overlay material, (2) heat-to-heat variations in stress corrosion cracking (SCC) of Types 316NG and 347 SS, (3) SCC of sensitized Type 304 SS in water with cupric ion or organic acid impurities, (4) electrochemical potential (ECP) measurements under gamma irradiation, (5) SCC of ferritic steels, (6) strain-controlled fatigue of Type 316NG SS in air at ambient temperature, and (7) through-wall residual stress measurements and finite-element calculation of residual stresses in weldments treated by a mechanical stress improvement process (MSIP). Fracture-mechanics crack-growth-rate tests on Type 316NG SS have shown that transgranular cracking can occur even in high purity environments, whereas no crack growth was observed in Type 347 SS even in impurity environments. In tests on weld overlay specimens, no cracks penetrated into the overlay even in impurity environments. Instead, the cracks branched when they approached the overlay, and then grew parallel to interface. In SCC tests on sensitized Type 304 SS, cupric ions at concentrations greater than ∼1 ppm were found to be deleterious, whereas organic acids at this concentration were not detrimental. Tests on several ferritic steels indicate a strong correlation between the sulfur content of the steels and susceptibility to SCC. External gamma radiation fields produced a large positive shift in the ECP of Type 304 SS at low dissolved-oxygen concentrations (<5 ppb), whereas in the absence of an external gamma field there was no difference in the ECP values of irradiated and nonirradiated material. Fatigue data for Type 316NG SS are consistent with the ASME code mean curve at high strains, but fall below the curve at low strains. Calculations of the

Heavy ion beams from the new Hungarian ECR ion source

International Nuclear Information System (INIS)

Biri, S.; Valek, A.; Ditroi, F.; Koivisto, H.; Arje, J.; Stiebing, K.; Schmidt, L.

1998-01-01

The first beams of highly charged ions in Hungary were obtained in fall of 1996. The new 14.5 GHz ECR ion source of ATOMKI produced beams of multiply charged ions with remarkable intensities at first experiments. Since then, numerous further developments were carried out. An external electrondonor electrode drastically increased the plasma density and, consequently, the intensity of highly charged ions. These upgrades concentrated mainly on beams from gaseous elements and were carried out by the ECRIS team of ATOMKI. Another series of experiments - ionising from solids - however, was done in the framework of an international collaboration. The first metal ion beam has been extracted from the ECRIS in November 1997 using the known method of Metal Ions from Volatile Compounds (MIVOC). The possibility to put the MIVOC chamber inside the ion source was also tested and the dosing regulation problem of metal vapours inside the ion source was solved. As a result, beams of more than 10 μA of highly charged Fe and Ni ions were produced. (author)

Analytical methods for determination of free metal ion concentration, labile species fraction and metal complexation capacity of environmental waters: a review.

Science.gov (United States)

Pesavento, Maria; Alberti, Giancarla; Biesuz, Raffaela

2009-01-12

Different experimental approaches have been suggested in the last few decades to determine metal species in complex matrices of unknown composition as environmental waters. The methods are mainly focused on the determination of single species or groups of species. The more recent developments in trace elements speciation are reviewed focusing on methods for labile and free metal determination. Electrochemical procedures with low detection limit as anodic stripping voltammetry (ASV) and the competing ligand exchange with adsorption cathodic stripping voltammetry (CLE-AdCSV) have been widely employed in metal distribution studies in natural waters. Other electrochemical methods such as stripping chronopotentiometry and AGNES seem to be promising to evaluate the free metal concentration at the low levels of environmental samples. Separation techniques based on ion exchange (IE) and complexing resins (CR), and micro separation methods as the Donnan membrane technique (DMT), diffusive gradients in thin-film gels (DGT) and the permeation liquid membrane (PLM), are among the non-electrochemical methods largely used in this field and reviewed in the text. Under appropriate conditions such techniques make possible the evaluation of free metal ion concentration.

Changes in the Concentration of Ions in Saliva and Dental Plaque after Application of CPP-ACP with and without Fluoride among 6-9 Year Old Children

Directory of Open Access Journals (Sweden)

Poureslami H

2017-03-01

Full Text Available Statement of Problem: The casein phospho peptide-amorphous calcium phosphate with or without fluoride (CPP-ACPF and CPP-ACP respectively are of considerably new materials which are highly recommended for prevention of dental caries. However, there is a shortage in literature on how they affect the ion concentration of saliva or dental plaque. Objectives: The aim of this study was to evaluate the concentration of calcium, phosphate and fluoride in the plaque and saliva of children with Early Childhood Caries (ECC after applying the CPP-ACP paste in comparison with the use of CPP- ACPF paste. Materials and Methods: One ml of un-stimulated saliva of 25 preschool children was collected and then 1 mg of the plaque sample was collected from the buccal surfaces of the two first primary molars on the upper jaw. CPP-ACP as well as CPP- ACPF pastes were applied on the tooth surfaces in two separate steps. In steps, plaque and saliva sampling was performed after 60 minutes. The amount of calcium ions was measured by Atomic Absorption Device and the amount of phosphate and fluoride ions was measured by Ion Chromatography instrument. Data were analyzed using Repeated Measurements ANOVA at a p < 0.05 level of significance. Results: Application of both CPP-ACPF and CPP-ACP significantly increased the concentration of calcium, phosphate, and fluoride in both saliva and dental plaque. Moreover, significantly higher salivary fluoride concentration was seen after application of CPP-ACPF compared to CPP-ACP. No other significant difference was observed between these two materials. Conclusions: CPP-ACPF can be more useful than CPP-ACP in protecting the primary teeth against caries process, especially when there is poor hygiene.

Immobilization of α-amylase and amyloglucosidase onto ion-exchange resin beads and hydrolysis of natural starch at high concentration.

Science.gov (United States)

Gupta, Kapish; Jana, Asim Kumar; Kumar, Sandeep; Maiti, Mithu

2013-11-01

α-Amylase was immobilized on Dowex MAC-3 with 88 % yield and amyloglucosidase on Amberlite IRA-400 ion-exchange resin beads with 54 % yield by adsorption process. Immobilized enzymes were characterized to measure the kinetic parameters and optimal operational parameters. Optimum substrate concentration and temperature were higher for immobilized enzymes. The thermal stability of the enzymes enhanced after the immobilization. Immobilized enzymes were used in the hydrolysis of the natural starch at high concentration (35 % w/v). The time required for liquefaction of starch to 10 dextrose equivalent (DE) and saccharification of liquefied starch to 96 DE increased. Immobilized enzymes showed the potential for use in starch hydrolysis as done in industry.

Patrick Air Force Base Storm Water Pollution Prevention Plan.

Science.gov (United States)

1994-09-01

7758987 Cupric sulfate 77-47-4 Hexachlorocyclopentadliene 10380297 Cupric sulfate, ammoniated 67-72-1 H-exachloroethane 815827 Cupric tartrate 76-47-01...28300745 Antimony potassium 75-00-3 Chloroethane (Ethyl chlo- tartrate ride) 7789619 Antimony tribromide 67-66-3 Chloroform 10025919 Antimony...5 p-Cresol 7787475 Beryllium chloride 1319-77-3 Cresol (mixed isomers) 7787497 Beryllium fluoride 142712 Cupric acetate 7787555 Beryllium nitrate

Ion chromatography separation of lanthanides at trace concentrations from Gd Matrix and quantification by ICP-MS

International Nuclear Information System (INIS)

Raut, V.V.; Jeyakumar, S.; Nagar, B.K.; Deb, S.B.; Saxena, M.K.; Tomar, B.S.

2014-01-01

Gadolinium compounds are mainly used as burnable poison. The presence of certain impurities is undesirable in the nuclear grade Gd compounds. Gd 2 O 3 , a most common raw material used for the preparation of nuclear grade Gd compounds. Analysis of rare earth impurities in Gd-matrices is one of the important exercises carried out to ensure the purity of Gd 2 O 3 . Determination of lanthanides at trace concentrations in lanthanide (Gd) matrix is complicated and difficult to realize. This is because the selective separation of REE's in one of the lanthanide elements is a challenging task. The present study was carried out to explore the feasibility of separating trace level lanthanides from Gd matrix by ion interaction chromatography (IIC) and to develop an analytical methodology for the determination of lanthanides by inductively coupled plasma mass spectrometry (ICP-MS). In the present investigation, the reversed phase column was dynamically modified into sulphonic acid functionalized surface by using 0.025 M n-Octane sulphonic acid (OSA). With α-HIBA eluent system, the elution order follows as Lu to La. The separations are employed with gradient elution mode. Since the sample has large excess of Gd, elution profiles with concentration gradient of HIBA were attempted. Separated fractions of Light lanthanides (LLn) and Heavy lanthanides (HLn) were collected and analyzed by ICP-MS. During MS analysis, it was observed that due to high concentration of salt (Na salt of OSA) present in the collected fractions caused difficulty in ICP-MS . Hence the experiments were carried out using another ion interacting reagent viz. 0.03 M camphor-10-sulphonic acid (CSA). Initial concentration of HIBA was kept at 0.025 M up to 15 min for the elution of HLns i.e. from Lu to Tb and it was then increased to 0.05 M to 0.3 M in 30 min. After elution of Tb, outlet of the column was switched to drain for 7 min to separate bulk Gd fraction. From 22 to 35 min effluent fraction containing Eu

Ion sensors based on novel fiber organic electrochemical transistors for lead ion detection.

Science.gov (United States)

Wang, Yuedan; Zhou, Zhou; Qing, Xing; Zhong, Weibing; Liu, Qiongzhen; Wang, Wenwen; Li, Mufang; Liu, Ke; Wang, Dong

2016-08-01

Fiber organic electrochemical transistors (FECTs) based on polypyrrole and nanofibers have been prepared for the first time. FECTs exhibited excellent electrical performances, on/off ratios up to 10(4) and low applied voltages below 2 V. The ion sensitivity behavior of the fiber organic electrochemical transistors was investigated. It exhibited that the transfer curve of FECTs shifted to lower gate voltage with increasing cations concentration, the sensitivity reached to 446 μA/dec in the 10(-5)-10(-2) M Pb(2+) concentration range. The ion selective properties of the FECTs have also been systematically studied for the detection of potassium, calcium, aluminum, and lead ions. The devices with different cations showed great difference in response curves. It was suitable for selectively monitoring Pb(2+) with respect to other cations. The results indicated FECTs were very effective for electrochemical sensing of lead ion, which opened a promising perspective for wearable electronics in healthcare and biological application. Graphical Abstract The schematic diagram of fiber organic electrochemical transistors based on polypyrrole and nanofibers for ion sensing.

Lixiviación oxidante de sulfuros complejos en soluciones de cloruro amónico: cinética de la lixiviación de la esfalerita

Directory of Open Access Journals (Sweden)

Limpo, J. L.

1997-08-01

Full Text Available Recent studies on chloride leaching of sphalerite are rewieved. The kinetics of oxygen leaching of sphalerite in concentrated ammonium chloride solutions in the presence of cupric ion has been studied. A pure sphalerite and a zinc concentrate have been tested. 80-130 °C temperature range, the dissolution occurred according to a mixed model which assumed both diffusion through sulfur layer and a surface reaction in the shrinking core model. This is described mathematically as: [1-(1-X^1/3] + B [1[ -2/3 X-(1-X^2/3] = k_rt. The effect of temperature, cupric concentration and particle size on the dissolution rate were determinated. The activation energy of the rate constant k_r for the pure sphalerite and zinc concentrate was found to be 66.4 and 67.6 kJ/mol respectively. The dissolution rate increased as the 0.43 power of the cupric cloride concentration. The results obtained for the effect of particle size show, such as it is predicted by the kinetic mixed model, that the rate constant k_r is inversely related, and the parameter B is directly related, to particle radius.

Tras la revisión de las publicaciones recientes sobre la lixiviación de esfalerita en medio cloruro, se presentan los resultados obtenidos en el estudio de la cinética de la lixiviación oxidante con oxígeno de esfalerita en soluciones concentradas de cloruro amónico en presencia de ion cúprico. Este estudio se ha realizado sobre una esfalerita de gran pureza y un concentrado diferencial de cinc. En el intervalo de temperatura estudiado (80 a 130 °C la disolución se produce de acuerdo con una cinética de control mixto según el modelo de "núcleo sin reaccionar", en el que tanto la difusión en la capa de azufre como la reacción química en el núcleo son etapas controlantes. La expresión matemática de este modelo es: [1-(1-X^1/3] + B [1[ -2/3 X-(1-X^2/3] = k_rt. Se ha estudiado la

Programmable ion mobility spectrometer: Time resolution improvement and ion counter comparison

International Nuclear Information System (INIS)

Harrison, R.G.; Wilding, R.J.

2005-01-01

Atmospheric ion mobility spectrometers operating on the aspirated electrode principle require switching of a bias voltage to select ions of different mobility. The ion spectrum can be obtained by sweeping across a set of bias voltages. If rapid temporal changes in atmospheric ion spectra are to be measured, however, such as for a balloon-carried instrument, the sweep time across the ion spectrum must be kept short. As bias voltage steps can generate saturation in the mobility spectrometer's electrometer amplifier, the electrometer recovery time limits the ion mobility spectrum sweep rate. Here, active compensation of the charge injected at a bias voltage step is used to reduce the saturation time. Further, the optimal setting of the charge compensation circuitry provides a determination of the system capacitance, a necessary calibration parameter for absolute measurements. Using laboratory air, hourly variations in ion concentrations and air conductivity found using the voltage switching system were similar to those obtained with a traditional ion counter operating at a single mobility: ion growth, however, could only be detected using the ion spectrometer

Effect of pH and complementary ion concentration on nitrate removal using puroliteA400 Resin impregnated Cu in batch system

Science.gov (United States)

Turmuzi, M.; Tarigan, Z. N.; Nadapdap, L.; Batubara, F.

2018-02-01

The total nitrogen content in water bodies should be below 50 mg NO3 -/L (11.3 mgN/l) World Health Organization (WHO) 2006. The content of nitrogen exceeding the quality standard threshold will cause damage to the aquatic ecosystem and be carcinogenic to humans. The Purolite A-400 resin will be modified with Cu metal by batch method to see the adsorption allowance of nitrate in synthetic liquid waste with nitrate concentration of 50 mg/l. This study will evaluate the effect of pH and complementary ions on the adsorption process. From the result of the research, the second order pseudo model is the most suitable adsorption kinetics model. For the adsorption isotherms the most suitable model is the Freundlich adsorption isotherm model. The optimum pH conditions were at the range of 8.5. The addition of complementary ions sulfate and phosphate did not show any significant change, but sulfate is the most effective complementary ion with a content of 20 mg/l.

Uzonur et al., Afr J Tradit Complement Altern Med. (2013) 10(2):232 ...

African Journals Online (AJOL)

AJTCAM

stinging-hair density) is genetically based and heritable (Pollard and Briggs ..... show innate or acquired DNA band variations as appearance of bands, loss of ..... /d. T. 2,5. 2,0. 1,5. 1,0. 0,5. 0,0. Threshold deg. 78,5 79,0 79,5 80,0 80,5 81,0 81,5 ... polyphenols and vitamins C and E, using their cupric ion reducing capability ...

Dopant-assisted negative photoionization Ion mobility spectrometry coupled with on-line cooling inlet for real-time monitoring H2S concentration in sewer gas.

Science.gov (United States)

Peng, Liying; Jiang, Dandan; Wang, Zhenxin; Hua, Lei; Li, Haiyang

2016-06-01

Malodorous hydrogen sulfide (H2S) gas often exists in the sewer system and associates with the problems of releasing the dangerous odor to the atmosphere and causing sewer pipe to be corroded. A simple method is in demand for real-time measuring H2S level in the sewer gas. In this paper, an innovated method based on dopant-assisted negative photoionization ion mobility spectrometry (DANP-IMS) with on-line semiconductor cooling inlet was put forward and successfully applied for the real-time measurement of H2S in sewer gas. The influence of moisture was effectively reduced via an on-line cooling method and a non-equilibrium dilution with drift gas. The limits of quantitation for the H2S in ≥60% relative humidity air could be obtained at ≤79.0ng L(-1) with linear ranges of 129-2064ng L(-1). The H2S concentration in a sewer manhole was successfully determined while its product ions were identified by an ion-mobility time-of-fight mass spectrometry. Finally, the correlation between sewer H2S concentration and the daily routines and habits of residents was investigated through hourly or real-time monitoring the variation of sewer H2S in manholes, indicating the power of this DANP-IMS method in assessing the H2S concentration in sewer system. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of chloride ion concentration on the corrosion behavior of Al-bearing TRIP steels

Energy Technology Data Exchange (ETDEWEB)

El-Taib Heakal, F., E-mail: fakihaheakal@yahoo.com [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Tantawy, N.S. [Chemistry Department, Girl' s College for Arts, Science and Education, Ain Shams University, Cairo (Egypt); Shehta, O.S. [Physical Chemistry Department, National Research Centre, Dokki, Giza (Egypt)

2011-10-17

Highlights: {yields} Systematic increase of chloride concentration has a critical influence on TRIP steel corrosion. {yields} TRIP microalloyed with Nb and Cr showed lower corrosion rate and smaller threshold Cl{sup -} value. {yields} Increasing Al content by 220 times in the TRIP deteriorates its corrosion behavior. {yields} Impedance results and surface examinations confirmed the obtained results. - Abstract: The effect of a systematic increase of chloride ion concentration on the electrochemical corrosion behavior of two types of Al-bearing TRIP steels (T{sub 1} and T{sub 2}) was studied in aqueous NaCl solutions. Several electrochemical techniques were used comprising open circuit potential measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Chloride concentration has a critical influence on the corrosion rate of the two tested steel samples. For both steels the corrosion rate first increased with increasing chloride content up to a certain critical concentration (CC), and then decreased in solution with chloride level higher than the threshold value. TRIP steel T{sub 1} microalloyed with Nb and Cr as compared to steel T{sub 2} not containing these two elements, exhibited lower corrosion rate and smaller CC value, indicating better corrosion resistance to chloride attack, albeit the Al content in T{sub 2} is 220 times higher than that in T{sub 1}. This is because Nb alloyed with TRIP steel likely enhances the formation on the surface of a stable rust layer enriched with other passivating elements Al, Cu, Cr and Ni, which has higher corrosion resistance and hence improve greatly the passive performance of the TRIP sample. The ac impedance data are in good agreement with the OCP and dc polarization measurements. Surface examinations via scanning electron microscope confirmed well the obtained results.

Influence of chloride ion concentration on the corrosion behavior of Al-bearing TRIP steels

International Nuclear Information System (INIS)

El-Taib Heakal, F.; Tantawy, N.S.; Shehta, O.S.

2011-01-01

Highlights: → Systematic increase of chloride concentration has a critical influence on TRIP steel corrosion. → TRIP microalloyed with Nb and Cr showed lower corrosion rate and smaller threshold Cl - value. → Increasing Al content by 220 times in the TRIP deteriorates its corrosion behavior. → Impedance results and surface examinations confirmed the obtained results. - Abstract: The effect of a systematic increase of chloride ion concentration on the electrochemical corrosion behavior of two types of Al-bearing TRIP steels (T 1 and T 2 ) was studied in aqueous NaCl solutions. Several electrochemical techniques were used comprising open circuit potential measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Chloride concentration has a critical influence on the corrosion rate of the two tested steel samples. For both steels the corrosion rate first increased with increasing chloride content up to a certain critical concentration (CC), and then decreased in solution with chloride level higher than the threshold value. TRIP steel T 1 microalloyed with Nb and Cr as compared to steel T 2 not containing these two elements, exhibited lower corrosion rate and smaller CC value, indicating better corrosion resistance to chloride attack, albeit the Al content in T 2 is 220 times higher than that in T 1 . This is because Nb alloyed with TRIP steel likely enhances the formation on the surface of a stable rust layer enriched with other passivating elements Al, Cu, Cr and Ni, which has higher corrosion resistance and hence improve greatly the passive performance of the TRIP sample. The ac impedance data are in good agreement with the OCP and dc polarization measurements. Surface examinations via scanning electron microscope confirmed well the obtained results.

The kinetics of the cerium(IV)-uranium(IV) reaction at low sulfate concentrations

International Nuclear Information System (INIS)

Michaille, P.; Kikindai, T.

1977-01-01

The rate of oxidation of uranium(IV) by cerium(IV) was measured with a stopped-flow spectrophotometer at sulfuric acid concentrations of 2 x 10 -6 to 0.5 M. At a constant hydrogen ion concentration of 0.5 M, the maximum rate constant was observed for 2 x 10 -3 M sulfuric acid; at that concentration, two sulfate ions were involved in the activated complex. The dependence of the rate constant on the hydrogen ion concentration showed that the reaction paths involving one or two sulfate ions also involved one hydroxyl ion, whereas one hydrogen ion was involved in the five sulfate dependent path. Spectrophotometric measurements supported the existence of a hydrolyzed monosulfatocomplex of cerium(IV). (author)

Respective influence of thermodynamic, hydrodynamic and diffusion factors on ion exchanger operation. Application to the ion exchanger NYMPHEA

International Nuclear Information System (INIS)

Nicoud, R.M.

1987-01-01

Nymphea is an annular ion exchanger, with a resin bed 30 centimeter-thick, used for purification of the water from the spent fuel storage pool at La Hague reprocessing plant. Very low concentration solutions (10 -12 eq/l for cobalt) are purified by Nymphea, and parameter must be extrapolated from the range 0.01 - 0.0001 eq/l to very low concentrations. A model is developed, describing ion state inside the grains. The limiting step in Nymphea operation is external diffusion. Diffusion time is determined by mean grain size which should be accurately defined for extrapolation of results from monodispersed distribution (often the case in laboratories) to polydispersed (often the case in industry). Operation of an ion exchanger can be simulated for any ion number in solution. In steady state condition of concentration pool purification increases with flow rate. Simulation in transient operation allows the determination of all the concentrations in function of time and hence to calculate the time to reach the maximum permissible concentration for cobalt. This time depends upon calcium pollution (by fuel can dissolution, atmospheric pollution) which is not accurately known [fr

Plasma source ion implantation

International Nuclear Information System (INIS)

Conrad, J.R.; Forest, C.

1986-01-01

The authors' technique allows the ion implantation to be performed directly within the ion source at higher currents without ion beam extraction and transport. The potential benefits include greatly increased production rates (factors of 10-1000) and the ability to implant non-planar targets without rastering or shadowing. The technique eliminates the ion extractor grid set, beam raster equipment, drift space and target manipulator equipment. The target to be implanted is placed directly within the plasma source and is biased to a large negative potential so that plasma ions gain energy as they accelerate through the potential drop across the sheath that forms at the plasma boundary. Because the sheath surrounds the target on all sides, all surfaces of the target are implanted without the necessity to raster the beam or to rotate the target. The authors have succeeded in implanting nitrogen ions in a silicon target to the depths and concentrations required for surface treatment of materials like stainless steel and titanium alloys. They have performed ESCA measurements of the penetration depth profile of a silicon target that was biased to 30 kV in a nitrogen discharge plasma. Nitrogen ions were implanted to a depth of 700A at a peak concentration of 30% atomic. The measured profile is quite similar to a previously obtained profile in titanium targets with conventional techniques

Long-range Transported African Dust in the Caribbean Region: Dust Concentrations and Water-soluble Ions

Science.gov (United States)

Santos-Figueroa, G.; Avilés-Piñeiro, G. M.; Mayol-Bracero, O. L.

2017-12-01

Long-range transported African dust (LRTAD) particles reach the Caribbean region every year during the summer months causing an increase in PM10 concentrations and by consequence degradation of air quality. During African dust (AD) incursions at the Caribbean region, PM10 concentration could exceeds the exposure limit of 50 µg/m³ 24-hour mean established by the World Health Organization (WHO). To have a better understanding of the impacts of AD particles to climate and public health at the Caribbean region it is necessary to study and determine the spatial and temporal distribution of dust particles. In order to address this, aerosols samples were collected during and absence of AD incursions during the summer of 2017 using a Hi-Volume (Hi-Vol) sampler for total suspended particles (TSP) at two sampling stations in Puerto Rico. The first station is a marine site located at Cabezas de San Juan (CSJ) Nature Reserve in Fajardo, and the second station is an urban site located at the Facundo Bueso (FB) building at the University of Puerto Rico-Rio Piedras. Aerosol samples were collected using Whatman 41 grade filters from which we determined the concentration of dust particles and the water-soluble ions (e.g., Na+, NH4+, Ca+2, Cl-, SO4-2) in the presence and absence of LRTAD particles. Saharan Air Layer (SAL) imagery, the results from the air mass backward trajectories calculated with the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), and the spectral coefficients from measurements at CSJ were used to monitor and confirm the presence of air masses coming from North Africa. Average dust concentrations using the Stacked-Filter Units (SFUs) at CSJ are around 4 μg/m3. LRTAD concentrations and ionic speciation results using the Hi-Vol for the marine and urban sites will be presented at the conference.

Spray-type drying unit for spent ion exchange resins, sludges and radioactive concentrates

International Nuclear Information System (INIS)

Raibaud, J.

1986-01-01

The process for drying radwaste in the liquid form or in aqueous suspension is a very attractive solution from the standpoint of volume reduction. Most of the existing drying facilities are not well adapted for drying the varieties of aqueous waste produced by the nuclear research centres and nuclear power plants, such as: - ion exchange resins, bead type or powdered resins, - centrifuge sludges, - settling sludges, - evaporator bottoms. Technicatome has selected the LEAFLASH process developed by Rhone Poulenc Recherches for drying the nuclear aqueous waste. This process has been well tried at full scale in a large number of industrial branches. The advantages of the process have been confirmed by the results obtained in operating a pilot facility. They include: - high flexibility in operation: - quick start-up and stoppage procedures, - adaptation to a wide spectrum of liquid waste without significant changes in the adjustment of the device. - compactness, - low power consumption, - complete drying of the waste for any initial concentration [fr

Ion source based on Penning discharge for production of doubly charged helium ions

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V. I. Voznyi

2017-11-01

Full Text Available The article presents the results of operation of ion source with Penning discharge developed in the IAP of NAS of Ukraine to produce doubly charged helium ions He2+ beam and to increase the energy of accelerated ions up to 3.2 MeV. This energy is necessary for ERDA channel when measuring hydrogen concentration in the structural materials used in nuclear engineering. The ion source parameters are the following: discharge voltage is 6 kV, discharge current is 0.8 - 1.2 mA, the current of singly charged helium ions He+ 24 μA, the current of doubly charged helium ions He2+ 0.5 μA.

Lime, agent to uranium concentration; La chaux comme agent de concentration de l'uranium

Energy Technology Data Exchange (ETDEWEB)

Mouret, P; Le Bris, J; Kremer, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Gautier, R [Etablissement Kuhlmann, Service d' Etudes et de Pilotages Industriels (France)

1958-07-01

Choice of the process according to health requirements. Description of the process: dissolution of uranium by sulfuric leaching of ores, precipitation of uranium by lime, re-dissolution of the concentrate with nitric ions, purification by T.B.P. finally resulting in pure uranyl nitrate solution containing 400 g/litre. (author)Fren. [French] Les raisons du choix du procede en fonction des imperatifs d'hygiene, sont exposees ainsi que le procede qui consiste en une dissolution de l'uranium des minerais par lixiviation sulfurique, precipitation de l'uranium par la chaux et redissolution du concentre en presence d'ions nitriques, purification par le T.B.P. et obtention d'un concentre final de nitrate d'uranyle pur a 400 g/litre. (auteur)

Variations in Calcium and Alginate Ions Concentration in Relation to the Properties of Calcium Alginate Nanoparticles

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Hamed Daemi

2013-05-01

Full Text Available Alginate belongs to a group of natural polymers called polysaccharides. They have carboxylic functional groups beside hydroxyls which are common in all polysaccharides. These materials show interesting properties due to theirfunctional groups. One of these properties is the ability of this polymer as a suitable carrier of protecting and transferring drugs and biomolecules. The particle sizes of these polymers are very important for their applications, so different techniques were used for preparation of these materials. In this way polymeric nanoparticles of calcium alginate which are excellent carriers in drug delivery systems were prepared by addition of calcium chloride solution to dilute solution of sodium alginate. Investigation of the size and distribution of nanoparticles were analyzed by SEM method. The concentration effects of both alginate and calcium ions on the size and distribution of  nanoparticles were studied in this research. Results showed that the size of nanoparticles obviously decreased with decreasing polymeric alginate concentration because of lower active sites in polymer chain. On the other hand, thesize and distribution of nanoparticles are significantly improved with increase of calcium cation concentrations. The mean particle size 40-70 nm and spherical shape are the main characteristics of the prepared nanoparticles.

Energy recovery from effluents of sugar processing industries in the UASB reactors seeded with granular sludge developed under low and high concentrations of calcium ion

Energy Technology Data Exchange (ETDEWEB)

Raphael, D M; Rubindamayugi, M S.T. [Univ. of Dar es Salaam, Dept. of Botany, Applied Microbiology Unit (Tanzania, United Republic of)

1998-12-31

The digestion of wastewater from sugar processing industries in a single phase UASB reactor was evaluated by a step wise increase in organic loading rate. This study was conducted to compare the treatability of effluents from sugar processing industries in a single phase UASB reactors inoculated with granular sludge developed under low and high concentrations of calcium ions. At OLR of 11.34 g COD/l/day and HRT of 16 hours, UASB reactor R2 attained a COD removal efficiency of 90% with a maximum methane production rate of 3 l/l/day. From the results, the digestion of the wastewater from sugar industries in the UASB reactor inoculated with granular sludge developed under high calcium ion concentration seem feasible with regard to COD removal efficiency and methane production rate. (au) 24 refs.

Energy recovery from effluents of sugar processing industries in the UASB reactors seeded with granular sludge developed under low and high concentrations of calcium ion

Energy Technology Data Exchange (ETDEWEB)

Raphael, D.M.; Rubindamayugi, M.S.T. [Univ. of Dar es Salaam, Dept. of Botany, Applied Microbiology Unit (Tanzania, United Republic of)

1997-12-31

The digestion of wastewater from sugar processing industries in a single phase UASB reactor was evaluated by a step wise increase in organic loading rate. This study was conducted to compare the treatability of effluents from sugar processing industries in a single phase UASB reactors inoculated with granular sludge developed under low and high concentrations of calcium ions. At OLR of 11.34 g COD/l/day and HRT of 16 hours, UASB reactor R2 attained a COD removal efficiency of 90% with a maximum methane production rate of 3 l/l/day. From the results, the digestion of the wastewater from sugar industries in the UASB reactor inoculated with granular sludge developed under high calcium ion concentration seem feasible with regard to COD removal efficiency and methane production rate. (au) 24 refs.

Analyzing silver concentration in soil using laser-induced breakdown spectroscopy

Science.gov (United States)

Prasetyo, S.; Isnaeni; Zaitun; Mitchell, K.; Suliyanti, M. M.; Herbani, Y.

2018-03-01

Determination of concentration of heavy metal ions in soil, such as silver, is very important to study soil pollution levels. Several techniques have been developed to determine silver ion concentration in soil. In this paper, we utilized laser-induced breakdown spectroscopy (LIBS) to study silver concentration in soil. We used four different data analysis methods to calculate silver concentration. In this case, we prepared soil samples with different silver ion concentrations from 400 ppm to 1000 ppm. Our analysis was focused on the 843.15 nm silver atomic absorption line. We found that plasma intensity increased as silver concentration increased. Our findings were based on our analysis using four different analysis methods. We believe that these analysis methods are able to calculate silver concentration in soil using LIBS.

Carrier concentration induced ferromagnetism in semiconductors

International Nuclear Information System (INIS)

Story, T.

2007-01-01

In semiconductor spintronics the key materials issue concerns ferromagnetic semiconductors that would, in particular, permit an integration (in a single multilayer heterostructure) of standard electronic functions of semiconductors with magnetic memory function. Although classical semiconductor materials, such as Si or GaAs, are nonmagnetic, upon substitutional incorporation of magnetic ions (typically of a few atomic percents of Mn 2+ ions) and very heavy doping with conducting carriers (at the level of 10 20 - 10 21 cm -3 ) a ferromagnetic transition can be induced in such diluted magnetic semiconductors (also known as semimagnetic semiconductors). In the lecture the spectacular experimental observations of carrier concentration induced ferromagnetism will be discussed for three model semiconductor crystals. p - Ga 1-x Mn x As currently the most actively studied and most perspective ferromagnetic semiconductor of III-V group, in which ferromagnetism appears due to Mn ions providing both local magnetic moments and acting as acceptor centers. p - Sn 1-x Mn x Te and p - Ge 1-x Mn x Te classical diluted magnetic semiconductors of IV-VI group, in which paramagnet-ferromagnet and ferromagnet-spin glass transitions are found for very high hole concentration. n - Eu 1-x Gd x Te mixed magnetic crystals, in which the substitution of Gd 3+ ions for Eu 2+ ions creates very high electron concentration and transforms antiferromagnetic EuTe (insulating compound) into ferromagnetic n-type semiconductor alloy. For each of these materials systems the key physical features will be discussed concerning: local magnetic moments formation, magnetic phase diagram as a function of magnetic ions and carrier concentration as well as Curie temperature and magnetic anisotropy engineering. Various theoretical models proposed to explain the effect of carrier concentration induced ferromagnetism in semiconductors will be briefly discussed involving mean field approaches based on Zener and RKKY

Effect of heavy ion irradiation on sucrose radical production

International Nuclear Information System (INIS)

Nakagawa, Kouichi; Sato, Yukio

2004-01-01

We investigated sucrose radicals produced by heavy-ion irradiation with various LETs (linear energy transfer) and the possibility for a sucrose ESR (electron spin resonance) dosimeter. The obtained spectral pattern was the same as that for helium (He) ions, carbon (C) ions, neon (Ne) ions, argon (Ar) ions, and iron (Fe) ions. Identical spectra were measured after one year, but the initial intensities decreased by a few percent when the samples were kept in ESR tubes with the caps at ambient temperature. The total spin concentration obtained by heavy-ion irradiation had a linear relation with the absorbed dose, and correlated logarithmically with the LET. Qualitative ESR analyses showed that the production of sucrose radicals depended on both the particle identity and the LET at the same dose. The production of spin concentration by He ions was the most sensitive to LET. Empirical relations between the LET and the spin yield for various particles imply that the LET at a certain dose can be estimated by the spin concentration. (authors)

Evaluation of the precision in fluoride determination in uranium concentrate

International Nuclear Information System (INIS)

Palmieri, Helena E. Leonhardt; Rocha, Zildete; Mata, Maria Olivia Cintra

1995-01-01

The fluoride in uranium concentrate is previously separated by steam distillation and then determined by direct potentiometric with an ion-select electrode. The potential of all ion-specific electrodes is a logarithmic function of the concentration of the ion to which the electrode in question responds. This relationship is expressed by the Nernst equation. A calibration curve, potential (mV) versus standard fluoride concentration is established and then the sample concentration is determined by interpolation. A least squares curve-fitting procedure has been used to determine the parameters of this calibration curve equation. Using these parameters are determined the standard deviation, the confidence limits and the precision of the fluoride concentrations. (author). 3 refs., 2 figs., 1 tab

Adsorption of lithium ion to amorphous hydrous aluminium oxide

International Nuclear Information System (INIS)

Wada, Hideo; Kitamura, Takao; Fujii, Ayako; Katoh, Shunsaku

1982-01-01

Adsorption process of lithium ion to amorphous hydrous aluminium oxide (a-HAO) was investigated by pH titration method with lithium chloride-lithium hydroxide mixed solution and X-ray diffraction analysis of a-HAO after pH titration. In the pH titration, the addition of hydroxide ion in amount from 0 to 4.0 mmol.g -1 gave no change to the pH of the solution and caused adsorption of lithium ion equivalent in amount to added hydroxide ion. X-ray diffraction analysis showed the formation of lithium hydrogenaluminate LiH (AlO 2 ) 2 .5H 2 O (LHA) in the a-HAO after pH titration. These results showed that adsorption of lithium ion by a-HAO was related to a reaction which consumed hydroxide ion and formed LHA. In order to elucidate detail process of the reaction, changes of pH, aluminium concentration and lithium concentration of the solution, respectively with time, were determined. The pH of the solution decreased in two stages. At the first stage of the pH decrease, the aluminium concentration increased whereas the lithium concentration did not change. At the second stage, the lithium concentration decreased together with the decrease of the aluminium concentration. It was inferred that adsorption of lithium ion proceeded through dissolution of a-HAO and precipitation of LHA. Theoretical adsorption capacity calculated from the above formula for LHA and aluminium content in a-HAO was 4.7 mmol.g -1 and agreed fairly well with observed value 4.0 mmol.g -1 . (author)

The trial of obtaining a high-grade gadolinium concentrate using the fractional precipitation together with the ion exchange

International Nuclear Information System (INIS)

Ozga, W.; Soltysiak, I.

1980-01-01

The modified fractional precipitation of lanthanon-potassium double chromate was used for preliminary separation of gadolinium concentrate containing 60% Gd 2 O 3 , 33,3% Sm 2 O 3 . The 1-st fraction enriched with samarium (60% Sm 2 O 3 ) and 2-nd fraction enriched with gadolinium (80% Gd 2 O 3 with efficiency of 82% recounting on Gd 2 O 3 ) were obtained. Both fractions were separated by the elution with EDTA solution buffered with ammonium acetate. The good results were obtained by ion exchange separation only of the 1-st fraction. (author)

Cytological comparison of gill chloride cells and blood serum ion concentrations in kutum (Rutilus frisii kutum spawners from brackish (Caspian Sea and fresh water (Khoshkrood River environments

Directory of Open Access Journals (Sweden)

Ghahremanzadeh Zahra

2014-09-01

Full Text Available The size and number of chloride cells and serum ion concentrations in kutum, Rutillus frisii kutum Nordman, from brackish (Caspian Sea and fresh water (Khoshkrood River environments were studied to gain a better understanding of osmoregulation in this species. Twenty mature kutum specimens were collected from the Caspian Sea (Anzali coasts, 8.49 ppt salinity and 12.4°C temperature and 20 specimens from Khoshkrood River (0.18 ppt salinity and 18°C temperature. Gill samples were analyzed histologically and concentrations of Na+, Cl- , K+, and Mg2+ ions were determined in the blood serum. Concentrations of Na+, Cl- , K+, and Mg2+ ions and osmotic pressure in mature kutum from brackish water were significantly higher than in specimens from fresh water. The average size and number of chloride cells in the fish from seawater were considerably larger than those from fresh water. The mean size of chloride cells was 6.89 ± 1.16 μm in brackish water samples and 5.1 ± 0.81 μm in river samples. The average number of chloride cells in brackish and river water samples were 16.92 and 6.57, respectively. The density and size of chloride cells increased with increases in salinity

Effect of Carbon Concentration on the Sputtering of Carbon-Rich SiC Bombarded by Helium Ions

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Xinghao Liang

2018-02-01

Full Text Available Silicon carbide (SiC is considered as an important material for nuclear engineering due to its excellent properties. Changing the carbon content in SiC can regulate and control its elastic and thermodynamic properties, but a simulation study of the effect of carbon content on the sputtering (caused by the helium ions of SiC is still lacking. In this work, we used the Monte-Carlo and molecular dynamics simulation methods to study the effects of carbon concentration, incidence energy, incident angle, and target temperature on the sputtering yield of SiC. The results show that the incident ions’ energy and angle have a significant effect on sputtering yield of SiC when the carbon concentration in SiC is around 62 at %, while the target temperature has a little effect on the sputtering yield of SiC. Our work might provide theoretical support for the experimental research and engineering application of carbon fiber-reinforced SiC that be used as the plasma-facing material in tokamak fusion reactors.

Concentration of elements on impregnated paper followed by their determination by peak chromatography

International Nuclear Information System (INIS)

Aleskovskaya, V.N.; Aleskovskij, V.B.; Bogdanova, Eh.G.

1977-01-01

To increase the limits of detection of ions Au, Ru and others in paper peak chromatography, their concentration is suggested on this very paper due to an increase of the analysed solution volume introduced on the paper. It is shown that deviation from the linear dependence of the peak heights on the determined ion concentration on the primary chromatograph near the limit of detection is explained by sorption of the ion with its precipitate. The concentration by two orders of magnitude enlargeds the concentration ranges of 1 - and Ru(3). The concentration is possible for small amounts of ions for which a nonlinear dependence occurs near the limit of detection

Dependence of ion - photon emission characteristics on the concentration of implanted atoms of the bombarding beam

International Nuclear Information System (INIS)

Belykh, S.F.; Evtukhov, R.N.; Redina, I.V.; Ferleger, V.Kh.

1989-01-01

Results of experiment, where Dy + beams, its spraying products emitting intensively optical radiation with continuous spectrum (CSR), are used for tantalum surface bombardment, are presented. The given experiment allowed one to separate the scattered particle CSR contribution and was conducted under controlled beam n atom concentration on the target surface. E 0 energy and j 0 dysprosium ion flux density made up respectively 3.5 keV and 3x10 5 Axcm -2 . The obtained result analysis has shown that a notable dependence of spectrum type on n value is detected. Dy scattered atoms to not emit CSR. The main contribution to CSR is made by sprayed particles, containing dysprosium atoms

CALCULATION OF AIR ION REGIME IN THE CASE OF ARTIFICIAL AIR IONIZATION

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BILIAIEV M. M.

2015-10-01

Full Text Available Purpose. One of the major tasks in the field of labor protection is providing of the necessary qualitative composition of air in the working areas of office and industrial spaces. In order to maintain the necessary air ion level in the air space premises, the artificial ionization of air is used often in the premises. At present in Ukraine analytical model are used for the calculation of air ion regime in premises, influencing on the formation process of air ions concentration field. An alternative solution is the use of CFD models, developing including the air jets aerodynamics in the premise, the presence of furniture, equipment, transfer of ions under an electric field, and other physical factors, determining intensity and shape of air ions concentration field in the premise. Methodology. Influence of air flow was taken into account in the development of CFD models for calculation of air ion regime in the apartment, caused by operation of ventilation, diffusion, electric field impact, as well as the interaction of different polarity ions with each other, and their interaction with dust particles. The proposed model of calculation of air ion regime in premises based on the use of aerodynamics, electrostatics and mass transfer levels. This model allows operatively to calculate air ions concentration field with the influence of the walls, floor, ceiling and obstacles on the process of air ions dispersion, the specific location of different polarity ions emission and their interaction in the premise and work areas in conditions of artificial air ionization. Results. The calculated data were obtained and on their base could be estimated the concentration of air ion anywhere in the premise with artificial air ionization. Ions concentration field, being calculated using this CFD model, as concentration field isolines is presented. Originality. The results of the air ion regime calculation in the premise are presented, based on numerical 2D CFD model

Control of colliding ion beams

International Nuclear Information System (INIS)

Salisbury, W.W.

1985-01-01

This invention relates to a method and system for enhancing the power-producing capability of a nuclear fusion reactor, and more specifically to methods and structure for enhancing the ion density in a directed particle fusion reactor. In accordance with the invention, oppositely directed ion beams constrained to helical paths pass through an annular reaction zone. The object is to produce fusion reactions due to collisions between the ion beams. The reaction zone is an annulus as between an inner-cylindrical electrode and an outer-cylindrical coaxial electrode. The beams are enhanced in ion density at spaced points along the paths by providing spline structures protruding from the walls of the electrodes into the reaction zone. This structure causes variations in the electric field along the paths followed by the ion beams. Such fields cause the beams to be successively more and less concentrated as the beams traverse the reaction zone. Points of high concentration are the points at which fusion-producing collisions are most likely to take place

Biological activities of Umbilicaria crustulosa (Ach.) frey acetone extract

OpenAIRE

Zlatanović Ivana; Stanković Miroslava; Stankov-Jovanović Vesna; Mitić Violeta; Zrnzević Ivana; Đorđević Aleksandra; Stojanović Gordana

2017-01-01

This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC) method. Additionally, the total phenolic compounds (TPC) and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteri...

Radiochemical purity and in vitro stability of Tc-99m radiopharmaceuticals

International Nuclear Information System (INIS)

Vucina, J.

2001-01-01

The increased contents of long lived 99 Tc, oxygen and cupric ions could affect the labeling yield of eight radiopharmaceuticals. Oxygen and in leaser extend copper were found to affect the radiochemical purity of the preparations. In vitro stability of radiopharmaceuticals, examined on 99m Tc(Sn)-pyrosphoshate solutions, was extended when ascorbic acid was added as the chemical stabilizer. The quantity of 5x10 -7 mol/dm 3 of ascorbic acid was found to be sufficient to keep the content of 99m Tc-pertechnetate below 1 % six hours after labeling even in the cases when 99m Tc was present in high radioactive concentrations (740-814 GBq/dm 3 ). The results led to the development of the kits in which ascorbic or gentisic acid are the standards component in the kit composition (author)

SEPARATION OF Fe (III, Cr(III, Cu(II, Ni(II, Co(II, AND Pb(II METAL IONS USING POLY(EUGENYL OXYACETIC ACID AS AN ION CARRIER BY A LIQUID MEMBRANE TRANSPORT METHOD

Directory of Open Access Journals (Sweden)

La Harimu

2010-06-01

Full Text Available Fe (III, Cr(III, Cu(II, Ni(II, Co(II, and Pb(II  metal ions had been separated using poly(eugenyl oxyacetic acid as an ion carrier by bulk liquid membrane transport method. The effect of pH, polyeugenyl oxyacetic acid ion carrier concentration, nitric acid concentration in the stripping solution, transport time, and metal concentration were optimized. The result showed that the optimum condition for transport of metal ions was at pH 4 for ion Fe(III and at pH 5 for Cr(III, Cu(II, Ni(II, Co(II, and Pb(II ions. The carrier volumes were optimum with concentration of 1 x 10-3 M at 7.5 mL for Cr(III, Cu (II,  Ni(II, Co(II ions and at 8.5 mL for Fe(III and Pb(II ions. The concentration of HNO3 in stripping phase was optimum at 2 M for Fe(III and Cu(II ions, 1 M for Cr(III, Ni(II and Co(II ions, and 0.5 M for Pb(II ion. The optimum transport times were 36 h for Fe(III and Co(II ions, and 48 h for Cr(III, Cu (II, Ni(II, and Pb(II ions. The concentration of metal ions accurately transported were 2.5 x 10-4 M for Fe(III and Cr(III ions, and 1 M for Cu (II, Ni(II, Co(II, and Pb(II ions. Compared to other metal ions the transport of Fe(III was the highest with selectivity order of Fe(III > Cr(III > Pb(II > Cu(II > Ni(II > Co(II. At optimum condition, Fe(III ion was transported through the membrane at 46.46%.   Keywords: poly(eugenyl oxyacetic acid, transport, liquid membrane, Fe (III, Cr(III, Cu(II, Ni(II, Co(II, and Pb(II ions

Determination of Nd3+ Ions in Solution Samples by a Coated Wire Ion-Selective Sensor

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Hassan Ali Zamani

2012-01-01

Full Text Available A new coated wire electrode (CWE using 5-(methylsulfanyl-3-phenyl-1H-1,2,4-triazole (MPT as an ionophore has been developed as a neodymium ion-selective sensor. The sensor exhibits Nernstian response for the Nd3+ ions in the concentration range of 1.0×10−6-1.0×10−2 M with detection limit of 3.7×10−7 M. It displays a Nernstian slope of 20.2±0.2 mV/decade in the pH range of 2.7–8.1. The proposed sensor also exhibits a fast response time of ∼5 s. The sensor revealed high selectivity with respect to all common alkali, alkaline earth, transition and heavy metal ions, including members of the lanthanide family other than Nd3+. The electrode was used as an indicator electrode in the potentiometric titration of Nd(III ions with EDTA. The electrode was also employed for the determination of the Nd3+ ions concentration in water solution samples.

Cementification for radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide

International Nuclear Information System (INIS)

Miyamoto, Shinya; Sato, Tatsuaki; Sasoh, Michitaka; Sakurai, Jiro; Takada, Takao

2005-01-01

For the cementification of radioactive waste that has large concentrations of sodium sulfate and radioactive nuclide, a way of fixation for sulfate ion was studied comprising the pH control of water in contact with the cement solid, and the removal of the excess water from the cement matrix to prevent hydrogen gas generation with radiolysis. It was confirmed that the sulfate ion concentration in the contacted water with the cement solid is decreased with the formation of ettringite or barium sulfate before solidification, the pH value of the pore water in the cement solid can control less than 12.5 by the application of zeolite and a low-alkali cement such as alumina cement or fly ash mixed cement, and removal of the excess water from the cement matrix by heating is possible with aggregate addition. Consequently, radioactive waste including high-concentration sodium sulfate and high-concentration radioactive nuclide can be solidified with cementitious materials. (author)

Atmospheric ions and nucleation: a review of observations

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A. Hirsikko

2011-01-01

Full Text Available This review is based on ca. 260 publications, 93 of which included data on the temporal and spatial variation of the concentration of small ions (<1.6 nm in diameter especially in the lower troposphere, chemical composition, or formation and growth rates of sub-3 nm ions. This information was collected on tables and figures. The small ions exist all the time in the atmosphere, and the average concentrations of positive and negative small ions are typically 200–2500 cm⁻³. However, concentrations up to 5000 cm⁻³ have been observed. The results are in agreement with observations of ion production rates in the atmosphere. We also summarised observations on the conversion of small ions to intermediate ions, which can act as embryos for new atmospheric aerosol particles. Those observations include the formation rates (J₂[ion] of 2-nm intermediate ions, growth rates (GR[ion] of sub-3 nm ions, and information on the chemical composition of the ions. Unfortunately, there were only a few studies which presented J₂[ion] and GR[ion]. Based on the publications, the formation rates of 2-nm ions were 0–1.1 cm⁻³ s⁻¹, while the total 2-nm particle formation rates varied between 0.001 and 60 cm⁻³ s⁻¹. Due to small changes in J₂[ion], the relative importance of ions in 2-nm particle formation was determined by the large changes in J₂[tot], and, accordingly the contribution of ions increased with decreasing J₂[tot]. Furthermore, small ions were observed to activate for growth earlier than neutral nanometer-sized particles and at lower saturation ratio of condensing vapours.

Dust ion-acoustic shock waves in magnetized pair-ion plasma with kappa distributed electrons

Science.gov (United States)

Kaur, B.; Singh, M.; Saini, N. S.

2018-01-01

We have performed a theoretical and numerical analysis of the three dimensional dynamics of nonlinear dust ion-acoustic shock waves (DIASWs) in a magnetized plasma, consisting of positive and negative ion fluids, kappa distributed electrons, immobile dust particulates along with positive and negative ion kinematic viscosity. By employing the reductive perturbation technique, we have derived the nonlinear Zakharov-Kuznetsov-Burgers (ZKB) equation, in which the nonlinear forces are balanced by dissipative forces (associated with kinematic viscosity). It is observed that the characteristics of DIASWs are significantly affected by superthermality of electrons, magnetic field strength, direction cosines, dust concentration, positive to negative ions mass ratio and viscosity of positive and negative ions.

Copper corrosion in irradiated environments. The influence of H2O2 on the electrochemistry of copper dissolution in HC1 electrolyte

International Nuclear Information System (INIS)

Smyrl, W.H.; Bell, B.T.; Atanasoski, R.T.; Glass, R.S.

1987-01-01

The anodic dissolution of copper has been examined in deaerated, 0.1 M HCl aqueous solution in the presence of H 2 O 2 . Concentrations of H 2 O 2 up to 0.2 M were studied at a rotating copper disk-platinum ring electrode. The open circuit potential (OCP) of copper was found to depend on both peroxide concentration and rotation rate. The OCP shifts towards more positive values with increasing H 2 O 2 concentration (C) and decreasing rotation rate (Omega). The dependence of OCP on (C/Omega/sup 1/2/) was the same as for oxygenated solutions reported earlier [1], at small values of (C/Omega/sup 1/2/). At higher values of (C/Omega/sup 1/2/), departure from the expected behavior was observed. The current-voltage curves for anodic dissolution of copper were also influenced by the presence of peroxide. The curves recorded with the potential scanned in the positive direction showed the expected 60 mV slope, but the reverse scans showed significant departures. At a given potential scan rate, hysteresis was observed which was larger for higher H 2 O 2 concentrations, lower rotation rates, and more positive anodic potential limits. Monitoring the cuprous ions at the outer Pt ring revealed that there was a complex set of events taking place at the copper surface, including film formation and the appearance of cupric ions. 13 references, 7 figures

Chemical composition of waterfall-induced air ions: Spectrometry vs. simulations

Energy Technology Data Exchange (ETDEWEB)

Parts, T.-E.; Luts, A. [Tartu Univ. (Estonia). Dept. of Environmental Physics; Laakso, L.; Hirsikko, A.; Groenholm, T.; Kulmala, M. [Helsinki Univ. (Finland). Dept. of Physical Sciences

2007-07-01

Our measurements of ion size distributions near a waterfall provided new evidence for a waterfall-induced modification of air ion sizes. The ion size spectrum near a waterfall permanently differs from that in ordinary tropospheric air. In this paper we investigated the near-waterfall air ions chemical nature in detail. We carried out a simulation series of air small negative ion evolution, proposing that falling water, as a new environmental component, increases the concentration of OH{sup -} cluster ions. The produced OH{sup -} ions were employed as an extra input for our ion evolution model. The presence of additional OH{sup -} ions resulted in a decrease of typically model-provided NO{sub 3}{sup -} and/or HSO{sub 4}{sup -} cluster ion concentrations and an increase of the abundance of HCO{sub 3}{sup -} cluster ions. Near the waterfall the latter ions became dominant in our simulations. (orig.)

Model Titan atmospheric hydrocarbon analysis by Ion Mobility Spectrometry in dry helium

International Nuclear Information System (INIS)

Kojiro, D.R.; Stimac, R.M.; Wernlund, R.F.; Cohen, M.J.

1990-01-01

Ion Mobility Spectrometry (IMS) is one analytical technique being investigated for the in situ analysis of the atmosphere of Titan. Any hydrocarbon ions that may form react immediately, in microseconds, with the high concentration of water vapor normally present in conventional IMS. By reducing the water concentration to the parts-per-billion range, the lifetime of the hydrocarbon ions may be increased to the milliseconds required for measurement. At low water level concentrations, other species may become the reactant ion. This study focuses on IMS analysis of expected Titan atmospheric hydrocarbons under very dry, low water concentration conditions

Calculation of the total plasma concentration of nonvolatile weak acids and the effective dissociation constant of nonvolatile buffers in plasma for use in the strong ion approach to acid-base balance in cats.

Science.gov (United States)

McCullough, Sheila M; Constable, Peter D

2003-08-01

To determine values for the total concentration of nonvolatile weak acids (Atot) and effective dissociation constant of nonvolatile weak acids (Ka) in plasma of cats. Convenience plasma samples of 5 male and 5 female healthy adult cats. Cats were sedated, and 20 mL of blood was obtained from the jugular vein. Plasma was tonometered at 37 degrees C to systematically vary PCO2 from 8 to 156 mm Hg, thereby altering plasma pH from 6.90 to 7.97. Plasma pH, PCO2, and concentrations of quantitatively important strong cations (Na+, K+, and Ca2+), strong anions (Cl-, lactate), and buffer ions (total protein, albumin, and phosphate) were determined. Strong ion difference was estimated from the measured strong ion concentrations and nonlinear regression used to calculate Atot and Ka from the measured pH and PCO2 and estimated strong ion difference. Mean (+/- SD) values were as follows: Atot = 24.3 +/- 4.6 mmol/L (equivalent to 0.35 mmol/g of protein or 0.76 mmol/g of albumin); Ka = 0.67 +/- 0.40 x 10(-7); and the negative logarithm (base 10) of Ka (pKa) = 7.17. At 37 degrees C, pH of 7.35, and a partial pressure of CO2 (PCO2) of 30 mm Hg, the calculated venous strong ion difference was 30 mEq/L. These results indicate that at a plasma pH of 7.35, a 1 mEq/L decrease in strong ion difference will decrease pH by 0.020, a 1 mm Hg decrease in PCO2 will increase plasma pH by 0.011, and a 1 g/dL decrease in albumin concentration will increase plasma pH by 0.093.

Quartz crystal microbalance sensor using ionophore for ammonium ion detection.

Science.gov (United States)

Kosaki, Yasuhiro; Takano, Kosuke; Citterio, Daniel; Suzuki, Koji; Shiratori, Seimei

2012-01-01

Ionophore-based quartz crystal microbalance (QCM) ammonium ion sensors with a detection limit for ammonium ion concentrations as low as 2.2 microM were fabricated. Ionophores are molecules, which selectively bind a particular ion. In this study, one of the known ionophores for ammonium, nonactin, was used to detect ammonium ions for environmental in-situ monitoring of aquarium water for the first time. To fabricate the sensing films, poly(vinyl chloride) was used as the matrix for the immobilization of nonactin. Furthermore, the anionic additive, tetrakis (4-chlorophenyl) borate potassium salt and the plasticizer dioctyl sebacate were used to enhance the sensor properties. The sensor allowed detecting ammonium ions not only in static solution, but also in flowing water. The sensor showed a nearly linear response with the increase of the ammonium ion concentration. The QCM resonance frequency increased with the increase of ammonium ion concentration, suggesting a decreasing weight of the sensing film. The detailed response mechanism could not be verified yet. However, from the results obtained when using a different plasticizer, nitrophenyl octyl ether, it is considered that this effect is caused by the release of water molecules. Consequently, the newly fabricated sensor detects ammonium ions by discharge of water. It shows high selectivity over potassium and sodium ions. We conclude that the newly fabricated sensor can be applied for detecting ammonium ions in aquarium water, since it allows measuring low ammonium ion concentrations. This sensor will be usable for water quality monitoring and controlling.

The ion polytropic coefficient in a collisionless sheath containing hot ions

Energy Technology Data Exchange (ETDEWEB)

Lin, Binbin; Xiang, Nong, E-mail: xiangn@ipp.ac.cn; Ou, Jing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Center for Magnetic Fusion Theory, Chinese Academy of Sciences, Hefei 230031 (China)

2016-08-15

The fluid approach has been widely used to study plasma sheath dynamics. For a sheath containing hot ions whose temperature is greater than the electron's, how to truncate the fluid hierarchy chain equations while retaining to the fullest extent of the kinetic effects is always a difficult problem. In this paper, a one-dimensional, collisionless sheath containing hot ions is studied via particle-in-cell simulations. By analyzing the ion energy equation and taking the kinetic effects into account, we have shown that the ion polytropic coefficient in the vicinity of the sheath edge is approximately constant so that the state equation with the modified polytropic coefficient can be used to close the hierarchy chain of the ion fluid equations. The value of the polytropic coefficient strongly depends on the hot ion temperature and its concentration in the plasma. The semi-analytical model is given to interpret the simulation results. As an application, the kinetic effects on the ion saturation current density in the probe theory are discussed.

Depth concentrations of deuterium ions implanted into some pure metals and alloys

International Nuclear Information System (INIS)

Didyk, A.Yu.; Wisniewski, R.; Kitowski, K.; Wilczynska, T.; Hofman, A.; Kulikauskas, V.; Shiryaev, A.A.; Zubavichyus, Ya.V.

2011-01-01

Pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25-keV deuterium ions at fluences in the range (1.2-2.3) x 10 22 D + /m 2 . The post-treatment depth distributions of deuterium ions were measured 10 days and three months after the implantation by using Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS). Comparison of the obtained results allowed us to make conclusions about relative stability of deuterium and hydrogen gases in pure metals and diluted Pd alloys. Very high diffusion rates of implanted deuterium ions from V and Pd pure metals and Pd alloys were observed. Small-angle X-ray scattering revealed formation of nanosized defects in implanted corundum and titanium

Measurement of tritium concentration in urine

International Nuclear Information System (INIS)

Sekiyama, Shigenobu; Deshimaru, Takehide

1979-01-01

Concerning the safety management of the advanced thermal reactor ''Fugen'', the internal exposure management for tritium is important, because heavy water is used as the moderator in the reactor, and tritium is produced in the heavy water. Tritium is the radioactive nuclide with the maximum β-ray energy of 18 keV, and the radiation exposure is limited to the internal exposure in human bodies, as tritium is taken in through the skin and by breathing. The tritium concentration in urine of the operators of the Fugen plant was measured. As for tritium measurement, the analysis of raw urine, the analysis after passing through mixed ion exchange resin and the analysis after distillation are applied. The scintillator, the liquid scintillation counter, the ion exchange resin and the distillator are introduced. The preliminary survey was conducted on the urine sample, the scintillator the calibration, etc. The measuring condition, the measurement of efficiency, and the limitation of detection with various background are explained, with the many experimental data and the calculating formula. Concerning the measured tritium concentration in urine, the tritium concentrations in distilled urine, raw urine and the urine refined with ion exchange resin were compared, and the correlation formulae are presented. The actual tritium concentration value in urine was less than 50 pci/ml. The measuring methods of raw urine and the urine refined with ion exchange resin are adequate as they are quick and accurate. (Nakai, Y.)

High current vacuum arc ion source for heavy ion fusion

International Nuclear Information System (INIS)

Qi, N.; Schein, J.; Gensler, S.; Prasad, R.R.; Krishnan, M.; Brown, I.

1999-01-01

Heavy Ion fusion (HIF) is one of the approaches for the controlled thermonuclear power production. A source of heavy ions with charge states 1+ to 2+, in ∼0.5 A current beams with ∼20 micros pulse widths and ∼10 Hz repetition rates are required. Thermionic sources have been the workhorse for the HIF program to date, but suffer from sloe turn-on, heating problems for large areas, are limited to low (contact) ionization potential elements and offer relatively low ion fluxes with a charge state limited to 1+. Gas injection sources suffer from partial ionization and deleterious neutral gas effects. The above shortcomings of the thermionic ion sources can be overcome by a vacuum arc ion source. The vacuum arc ion source is a good candidate for HIF applications. It is capable of providing ions of various elements and different charge states, in short and long pulse bursts, with low emittance and high beam currents. Under a Phase-I STTR from DOE, the feasibility of the vacuum arc ion source for the HIF applications is investigated. An existing ion source at LBNL was modified to produce ∼0.5 A, ∼60 keV Gd (A∼158) ion beams. The experimental effort concentrated on beam noise reduction, pulse-to-pulse reproducibility and achieving low beam emittance at 0.5 A ion current level. Details of the source development will be reported

Concentration-elastic-stress instabilities in the distribution of ions and neutral particles in the insulator layer at the semiconductor surface

International Nuclear Information System (INIS)

Gol'dman, E. I.

2006-01-01

Mobile impurities in the form of ions and neutral associations are present in the insulator films that isolate the semiconductor from the metal electrode. If temperatures and the polarizing electric field are sufficiently high, impurities concentrate at the insulator-semiconductor interface where they exchange electrons with the semiconductor. It is shown that the pairwise interaction of particles via the field of elastic stresses caused by the concentration-related expansion of the insulator can give rise to an instability in the impurity distribution that is uniform over the contact. The stationary small-scale ordering of the particles over the contact of the insulator with the semiconductor arises in the solution of point defects, which is accompanied by annular flows of the particles

Fluoride ions vs removal technologies: A study

Directory of Open Access Journals (Sweden)

Jagvir Singh

2016-11-01

Full Text Available Literature reported that drinking water is a precious and scarce resource and it has to be protected and kept free from any kind of contamination. Further, it has to be used carefully without wasting. Literature also reported that fluoride bearing rocks are abundant in India, as a result, fluoride leaches out and contaminates the adjacent water and soil resources. A high concentration of fluoride ions in ground water increases up to more than 30 mg/L. This high concentration of fluoride ions causes many harmful and dangerous effects on our datum. Fluoride ions in larger quantities i.e. 20–80 mg/day taken over a period of 10–20 years result in crippling and skeletal fluorosis, severely damaging the bone. In the present scenario, there is a continuously increasing worldwide concern for the development of fluoride treatment technologies. Possibilities of reducing the high fluorine content in groundwater are by defluorination process/dilution with the surface water which is a very simple technique but the addition of Ca2+ ions to a solution in contact with fluorite when experimented in distilled water caused an appreciable decrease in fluoride concentration. In this review article, we emphasized the relationship between high concentrations of fluoride ions and their compounds and their health impact.

Monitoring Ion Activities In and Around Cells Using Ion-Selective Liquid-Membrane Microelectrodes

Directory of Open Access Journals (Sweden)

Mark D. Parker

2013-01-01

Full Text Available Determining the effective concentration (i.e., activity of ions in and around living cells is important to our understanding of the contribution of those ions to cellular function. Moreover, monitoring changes in ion activities in and around cells is informative about the actions of the transporters and/or channels operating in the cell membrane. The activity of an ion can be measured using a glass microelectrode that includes in its tip a liquid-membrane doped with an ion-selective ionophore. Because these electrodes can be fabricated with tip diameters that are less than 1 μm, they can be used to impale single cells in order to monitor the activities of intracellular ions. This review summarizes the history, theory, and practice of ion-selective microelectrode use and brings together a number of classic and recent examples of their usefulness in the realm of physiological study.

Simultaneous determination of free calcium, magnesium, sodium and potassium ion concentrations in simulated milk ultrafiltrate and reconstituted skim milk using the Donnan Membrane Technique

NARCIS (Netherlands)

Gao, R.; Temminghoff, E.J.M.; Leeuwen, van H.P.; Valenberg, van H.J.F.; Eisner, M.D.; Boekel, van M.A.J.S.

2009-01-01

This study focused on determination of free Ca2+, Mg2+, Na+ and K+ concentrations in a series of CaCl2 solutions, simulated milk ultrafiltrate and reconstituted skim milk using a recently developed Donnan Membrane Technique (DMT). A calcium ion selective electrode was used to compare the DMT

Environmental Review Guide for Operations (ERGO) - A Compliance Assessment Manual for Use at All USACE Civil-Funded Projects and Facilities

Science.gov (United States)

1994-03-01

23-8 Cupric oxalate 100 5893-66-3 Cupric sulfate 10 7758-98-7 Cupric sulfate ammoniated 100 10380-2% Cupric tartrate 100 81582 W Cyanides (soluble...sulfamate 5000 7773-06-0) Ammonium sulfate x 7783-20-2 (solution) Ammonium sulfide 100 12135-76-1 Ammonium sulfite 5000 10196-04-0 Ammonium tartrate 5000...14307-43-8 Ammonium tartrate 5000 3164-29-2 Ammonium thiocyanate 5000 1762-95-4 Ammonium vanadate 1000 P119 7803-55-6 Amphetamine 1000 300-62-9 Amyl

Simulation of a model nanopore sensor: Ion competition underlies device behavior

Science.gov (United States)

Mádai, Eszter; Valiskó, Mónika; Dallos, András; Boda, Dezső

2017-12-01

We study a model nanopore sensor with which a very low concentration of analyte molecules can be detected on the basis of the selective binding of the analyte molecules to the binding sites on the pore wall. The bound analyte ions partially replace the current-carrier cations in a thermodynamic competition. This competition depends both on the properties of the nanopore and the concentrations of the competing ions (through their chemical potentials). The output signal given by the device is the current reduction caused by the presence of the analyte ions. The concentration of the analyte ions can be determined through calibration curves. We model the binding site with the square-well potential and the electrolyte as charged hard spheres in an implicit background solvent. We study the system with a hybrid method in which we compute the ion flux with the Nernst-Planck (NP) equation coupled with the Local Equilibrium Monte Carlo (LEMC) simulation technique. The resulting NP+LEMC method is able to handle both strong ionic correlations inside the pore (including finite size of ions) and bulk concentrations as low as micromolar. We analyze the effect of bulk ion concentrations, pore parameters, binding site parameters, electrolyte properties, and voltage on the behavior of the device.

Towards High-Performance Aqueous Sodium-Ion Batteries: Stabilizing the Solid/Liquid Interface for NASICON-Type Na2 VTi(PO4 )3 using Concentrated Electrolytes.

Science.gov (United States)

Zhang, Huang; Jeong, Sangsik; Qin, Bingsheng; Vieira Carvalho, Diogo; Buchholz, Daniel; Passerini, Stefano

2018-02-22

Aqueous Na-ion batteries may offer a solution to the cost and safety issues of high-energy batteries. However, substantial challenges remain in the development of electrode materials and electrolytes enabling high performance and long cycle life. Herein, we report the characterization of a symmetric Na-ion battery with a NASICON-type Na 2 VTi(PO 4 ) 3 electrode material in conventional aqueous and "water-in-salt" electrolytes. Extremely stable cycling performance for 1000 cycles at a high rate (20 C) is found with the highly concentrated aqueous electrolytes owing to the formation of a resistive but protective interphase between the electrode and electrolyte. These results provide important insight for the development of aqueous Na-ion batteries with stable long-term cycling performance for large-scale energy storage. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zinc, copper and lead contents of wines. Comparison between the total concentrations by atomic absorption spectrometry and the concentrations of the free ions by polarography

Directory of Open Access Journals (Sweden)

J.-B. Fournier

1998-03-01

Full Text Available In the introduction of this article, some examples of the use of trace element data in the characterisation of viticultural produce are reminded. This paper described the determination of zinc, copper and lead by two techniques based on radically different principles. The atomic absorption spectrometry, applied after the mineralisation of the samples by wet process, allows the determination of the total element contents in wine. The polarography allows the analysis of the concentrations of these elements that are under labile chemical forms, and which are dissolved under the ionic forms Zn++, Cu++ and Pb++. The wines analysed in this study were produced from three different parcels chosen in relation to their geological qualities. The vines implanted on these parcels are strictly identical, and three fermentation techniques were applied to each lots of grapes. The results obtained shows that the copper is only under ionic form and that the temperature of the fermentation influences the total copper level in the final wine. At the opposite, there is no ion Pb++ in the samples, but a long duration of maceration increases the lead content. Concerning zinc, only the ions Zn++ are present in the wine in case of a short duration of the maceration. When this duration increases, some other chemical forms of zinc are dissolved in addition to the ions Zn++ which are instantaneously dissociated in aqueous solutions. The problem of the contamination of grapes by the materials used, the phytosanitary treatments and the atmospheric pollution is discussed. The knowledge of the proportion of a trace element that is under ionic forms is indispensable to evaluate the bio-availability of the considered element and the toxicologic risks. The advent and the expansion of the electrochemical methods is expected as an important advance in this field of research.

Cation–Anion Interactions within the Nucleic Acid Ion Atmosphere Revealed by Ion Counting

Science.gov (United States)

Gebala, Magdalena; Giambasu, George M.; Lipfert, Jan; Bisaria, Namita; Bonilla, Steve; Li, Guangchao; York, Darrin M.; Herschlag, Daniel

2016-01-01

The ion atmosphere is a critical structural, dynamic, and energetic component of nucleic acids that profoundly affects their interactions with proteins and ligands. Experimental methods that “count” the number of ions thermodynamically associated with the ion atmosphere allow dissection of energetic properties of the ion atmosphere, and thus provide direct comparison to theoretical results. Previous experiments have focused primarily on the cations that are attracted to nucleic acid polyanions, but have also showed that anions are excluded from the ion atmosphere. Herein, we have systematically explored the properties of anion exclusion, testing the zeroth-order model that anions of different identity are equally excluded due to electrostatic repulsion. Using a series of monovalent salts, we find, surprisingly, that the extent of anion exclusion and cation inclusion significantly depends on salt identity. The differences are prominent at higher concentrations and mirror trends in mean activity coefficients of the electrolyte solutions. Salts with lower activity coefficients exhibit greater accumulation of both cations and anions within the ion atmosphere, strongly suggesting that cation–anion correlation effects are present in the ion atmosphere and need to be accounted for to understand electrostatic interactions of nucleic acids. To test whether the effects of cation–anion correlations extend to nucleic acid kinetics and thermodynamics, we followed the folding of P4–P6, a domain of the Tetrahymena group I ribozyme, via single-molecule fluorescence resonance energy transfer in solutions with different salts. Solutions of identical concentration but lower activity gave slower and less favorable folding. Our results reveal hitherto unknown properties of the ion atmosphere and suggest possible roles of oriented ion pairs or anion-bridged cations in the ion atmosphere for electrolyte solutions of salts with reduced activity. Consideration of these new

Measurement of excitation, ionization, and electron temperatures and positive ion concentrations in a 144 MHz inductively coupled radiofrequency plasma

International Nuclear Information System (INIS)

Walters, P.E.; Chester, T.L.; Winefordner, J.D.

1977-01-01

Diagnostic measurements of 144 MHz radiofrequency inductively coupled plasmas at pressures between 0.5 and 14 Torr have been made. Other variables studied included the gas type (Ar or Ne) and material in plasma (Ti or Tl). Parameters measured included excitation temperatures via the atomic Boltzmann plot and the two-line method, ionization electric probes. Excitation temperatures increased as the pressure of Ar or Ne plasmas decreased and reached a maximum of approx.9000 degreeK in the latter case and approx.6700 degreeK in the former case; Tl in the Ar plasma resulted in in a smaller rate of decrease of excitation temperature with increase of pressure of Ar. The ionization temperatures were lower than the excitation temperatures and were similar for both the Ar and Ne plasmas. Electron temperatures were about 10 times higher than the excitation temperatures indicating non-LTE behavior. Again, the electron temperatures indicating in Ne were considerably higher than in Ar. With the presence of metals, the electron temperatures with a metal in the Ar plasma were higher than in the absence. Positive ion concentrations were also measured for the various plasmas and were found to be similar (approx.10 18 m -3 ) in both the Ar and Ne plasmas. The presence of metals caused significant increase in the positive ion concentrations. From the results obtained, the optimum Ar pressure for Tl electrodeless discharge lamps operated at 144 MHz would be between 2 and 4 Torr

Metallic ion release from biocompatible cobalt-based alloy

Directory of Open Access Journals (Sweden)

Dimić Ivana D.

2014-01-01

Full Text Available Metallic biomaterials, which are mainly used for the damaged hard tissue replacements, are materials with high strength, excellent toughness and good wear resistance. The disadvantages of metals as implant materials are their susceptibility to corrosion, the elastic modulus mismatch between metals and human hard tissues, relatively high density and metallic ion release which can cause serious health problems. The aim of this study was to examine metallic ion release from Co-Cr-Mo alloy in artificial saliva. In that purpose, alloy samples were immersed into artificial saliva with different pH values (4.0, 5.5 and 7.5. After a certain immersion period (1, 3 and 6 weeks the concentrations of released ions were determined using Inductively Coupled Plasma - Mass Spectrophotometer (ICP-MS. The research findings were used in order to define the dependence between the concentration of released metallic ions, artificial saliva pH values and immersion time. The determined released metallic ions concentrations were compared with literature data in order to describe and better understand the phenomenon of metallic ion release from the biocompatible cobalt-based alloy. [Projekat Ministarstva nauke Republike Srbije, br. III 46010 i br. ON 174004

Using precursor ion scan of 184 with liquid chromatography-electrospray ionization-tandem mass spectrometry for concentration normalization in cellular lipidomic studies.

Science.gov (United States)

Chao, Hsi-Chun; Chen, Guan-Yuan; Hsu, Lih-Ching; Liao, Hsiao-Wei; Yang, Sin-Yu; Wang, San-Yuan; Li, Yu-Liang; Tang, Sung-Chun; Tseng, Yufeng Jane; Kuo, Ching-Hua

2017-06-08

Cellular lipidomic studies have been favored approaches in many biomedical research areas. To provide fair comparisons of the studied cells, it is essential to perform normalization of the determined concentration before lipidomic analysis. This study proposed a cellular lipidomic normalization method by measuring the phosphatidylcholine (PC) and sphingomyelin (SM) contents in cell extracts. To provide efficient analysis of PC and SM in cell extracts, flow injection analysis-electrospray ionization-tandem mass spectrometry (FIA-ESI-MS/MS) with a precursor ion scan (PIS) of m/z 184 was used, and the parameters affecting the performance of the method were optimized. Good linearity could be observed between the cell extract dilution factor and the reciprocal of the total ion chromatogram (TIC) area in the PIS of m/z 184 within the dilution range of 1- to 16-fold (R 2  = 0.998). The calibration curve could be used for concentration adjustment of the unknown concentration of a cell extract. The intraday and intermediate precisions were below 10%. The accuracy ranged from 93.0% to 105.6%. The performance of the new normalization method was evaluated using different numbers of HCT-116 cells. Sphingosine, ceramide (d18:1/18:0), SM (d18:1/18:0) and PC (16:1/18:0) were selected as the representative test lipid species, and the results showed that the peak areas of each lipid species obtained from different cell numbers were within a 20% variation after normalization. Finally, the PIS of 184 normalization method was applied to study ischemia-induced neuron injury using oxygen and glucose deprivation (OGD) on primary neuronal cultured cells. Our results showed that the PIS of 184 normalization method is an efficient and effective approach for concentration normalization in cellular lipidomic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of nitrogen-ion-implanted aluminium

International Nuclear Information System (INIS)

Rauschenbach, B.; Breuer, K.; Leonhardt, G.

1990-01-01

Aluminium has been implanted with nitrogen ions at different temperatures. The implanted samples have been characterized by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and electron energy-loss spectroscopy (EELS). Deconvolution procedures are needed to separate the influence of the ion sputter profiling by AES and XPS from the nitrogen-ion-beam-induced effects. The chemical state of Al, N, O and C was identified by deconvolution of the measured spectra. In general, there were double-peak structures observed for N 1s and O 1s, identified as contributions from nitrides and weakly bound nitrogen, and oxides and weakly bound oxygen, respectively. Auger analysis confirms the influence of the nitrogen ion fluence on the shape of the concentration distribution. The influence of temperature on the chemical state of implanted aluminium and on the concentration distribution is discussed. (orig.)

High concentrations of Na+ and Cl- ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress.

Science.gov (United States)

Tavakkoli, Ehsan; Rengasamy, Pichu; McDonald, Glenn K

2010-10-01

Despite the fact that most plants accumulate both sodium (Na(+)) and chloride (Cl(-)) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na(+) accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na(+) and to Cl(-) separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na(+) and Cl(-) to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na(+) and Cl(-). Soils were prepared which were treated with Na(+) or Cl(-) by using a combination of different Na(+) salts and Cl(-) salts, respectively, or with NaCl. While this method produced Na(+)-dominant and Cl(-)-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na(+) and high Cl(-) reduced growth of faba bean but plants were more sensitive to Cl(-) than to Na(+). The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl(-) more than the concentration of Na(+). The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na(+) and Cl(-) simultaneously, but

Integrated sampling vs ion chromatography: Mathematical considerations

International Nuclear Information System (INIS)

Sundberg, L.L.

1992-01-01

This paper presents some general purpose considerations that can be utilized when comparisons are made between the results of integrated sampling over several hours or days, and ion chromatography where sample collection times are measured in minutes. The discussion is geared toward the measurement of soluble transition metal ions in BWR feedwater. Under steady-state conditions, the concentrations reported by both techniques should be in reasonable agreement. Transient operations effect both types of measurements. A simplistic model, applicable to both sampling techniques, is presented that demonstrates the effect of transients which occur during the acquisition of a steady-state sample. For a common set of conditions, the integrated concentration is proportional to the concentration and duration of the transient, and inversely proportional to the sample collection time. The adjustment of the collection period during a known transient allows an estimation of peak transient concentration. Though the probability of sampling a random transient with the integrated sampling technique is very high, the magnitude is severely diluted with long integration times. Transient concentrations are magnified with ion chromatography, but the probability of sampling a transient is significantly lower using normal ion chromatography operations. Various data averaging techniques are discussed for integrated sampling and IC determinations. The use of time-weighted averages appears to offer more advantages over arithmetic and geometric means for integrated sampling when the collection period is variable. For replicate steady-state ion chromatography determinations which bracket a transient sample, it may be advantageous to ignore the calculation of averages, and report the data as trending information only

Removal of strontium ions from solutions using granulated zeolites

International Nuclear Information System (INIS)

Bronic, J.; Subotic, B.

1992-01-01

The ion-exchange process on columns filled with granulated zeolites is determined by several physico-chemical parameters. The influence of these parameters (zeolite type, concentration of exchangeable ions in solution, temperature, flow rate, etc.) on the kinetics of ion-exchange process was studied by measuring the Sr 2+ ion concentration in solution before and after passing through a column filled with various granulated zeolites (zeolite 13X, zeolite A and synthetic mordenite). Using the experimental technique of radioactive labeling by 89 Sr, the distribution of Sr 2+ ions in column fillings were also determined. From the results obtained, the optimal conditions for the most efficient removal of strontium ions from solutions using granulated zeolites can be defined. (author) 24 refs.; 9 figs

Thermodynamic properties of copper compounds with oxygen and hydrogen from first principles

Energy Technology Data Exchange (ETDEWEB)

Korzhavyi, P.A.; Johansson, B. (Applied Materials Physics, Dept. of Materials Science and Engineering, Royal Inst. of Technology, Stockholm (Sweden))

2010-02-15

We employ quantum-mechanical calculations (based on density functional theory and linear response theory) in order to test the mechanical and chemical stability of several solid-state configurations of Cu1+, Cu2+, O2-, H1-, and H1+ ions. We begin our analysis with cuprous oxide (Cu{sub 2}O, cuprite structure), cupric oxide (CuO, tenorite structure), and cuprous hydride (CuH, wurtzite and sphalerite structures) whose thermodynamic properties have been studied experimentally. In our calculations, all these compounds are found to be mechanically stable configurations. Their formation energies calculated at T = 0 K (including the energy of zero-point and thermal motion of the ions) and at room temperature are in good agreement with existing thermodynamic data. A search for other possible solid-state conformations of copper, hydrogen, and oxygen ions is then performed. Several candidate structures for solid phases of cuprous oxy-hydride (Cu{sub 4}H{sub 2}O) and cupric hydride (CuH{sub 2}) have been considered but found to be dynamically unstable. Cuprous oxy-hydride is found to be energetically unstable with respect to decomposition onto cuprous oxide and cuprous hydride. Metastability of cuprous hydroxide (CuOH) is established in our calculations. The free energy of CuOH is calculated to be some 50 kJ/mol higher than the average of the free energies of Cu{sub 2}O and water. Thus, cuprite Cu{sub 2}O is the most stable of the examined Cu(I) compounds

Thermodynamic properties of copper compounds with oxygen and hydrogen from first principles

International Nuclear Information System (INIS)

Korzhavyi, P.A.; Johansson, B.

2010-02-01

We employ quantum-mechanical calculations (based on density functional theory and linear response theory) in order to test the mechanical and chemical stability of several solid-state configurations of Cu 1+ , Cu 2+ , O 2- , H 1- , and H 1+ ions. We begin our analysis with cuprous oxide (Cu 2 O, cuprite structure), cupric oxide (CuO, tenorite structure), and cuprous hydride (CuH, wurtzite and sphalerite structures) whose thermodynamic properties have been studied experimentally. In our calculations, all these compounds are found to be mechanically stable configurations. Their formation energies calculated at T = 0 K (including the energy of zero-point and thermal motion of the ions) and at room temperature are in good agreement with existing thermodynamic data. A search for other possible solid-state conformations of copper, hydrogen, and oxygen ions is then performed. Several candidate structures for solid phases of cuprous oxy-hydride (Cu 4 H 2 O) and cupric hydride (CuH 2 ) have been considered but found to be dynamically unstable. Cuprous oxy-hydride is found to be energetically unstable with respect to decomposition onto cuprous oxide and cuprous hydride. Metastability of cuprous hydroxide (CuOH) is established in our calculations. The free energy of CuOH is calculated to be some 50 kJ/mol higher than the average of the free energies of Cu 2 O and water. Thus, cuprite Cu 2 O is the most stable of the examined Cu(I) compounds

Development of exploding wire ion source for intense pulsed heavy ion beam accelerator

International Nuclear Information System (INIS)

Ochiai, Y.; Murata, T.; Ito, H.; Masugata, K.

2012-01-01

A Novel exploding wire type ion source device is proposed as a metallic ion source of intense pulsed heavy ion beam (PHIB) accelerator. In the device multiple shot operations is realized without breaking the vacuum. The basic characteristics of the device are evaluated experimentally with an aluminum wire of diameter 0.2 mm, length 25 mm. Capacitor bank of capacitance 3 μF, charging voltage 30 kV was used and the wire was successfully exploded by a discharge current of 15 kA, rise time 5.3 μs. Plasma flux of ion current density around 70 A/cm 2 was obtained at 150 mm downstream from the device. The drift velocity of ions evaluated by a time-of-flight method was 2.7x10 4 m/sec, which corresponds to the kinetic energy of 100 eV for aluminum ions. From the measurement of ion current density distribution ion flow is found to be concentrated to the direction where ion acceleration gap is placed. From the experiment the device is found to be acceptable for applying PHIB accelerator. (author)

Effects of lead on Na+, K+-ATPase and hemolymph ion concentrations in the freshwater mussel Elliptio complanata

Science.gov (United States)

Mosher, Shad; Cope, W. Gregory; Weber, Frank X.; Shea, Damian; Kwak, Thomas J.

2012-01-01

Freshwater mussels are an imperiled fauna exposed to a variety of environmental toxicants such as lead (Pb) and studies are urgently needed to assess their health and condition to guide conservation efforts. A 28-day laboratory toxicity test with Pb and adult Eastern elliptio mussels (Elliptio complanata) was conducted to determine uptake kinetics and to assess the toxicological effects of Pb exposure. Test mussels were collected from a relatively uncontaminated reference site and exposed to a water-only control and five concentrations of Pb (as lead nitrate) ranging from 1 to 245 mu g/L in a static renewal test with a water hardness of 42 mg/L. Endpoints included tissue Pb concentrations, hemolymph Pb and ion (Na+, K+, Cl-, Ca2+) concentrations, and Na+, K+-ATPase enzyme activity in gill tissue. Mussels accumulated Pb rapidly, with tissue concentrations increasing at an exposure-dependent rate for the first 2 weeks, but with no significant increase from 2 to 4 weeks. Mussel tissue Pb concentrations ranged from 0.34 to 898 mu g/g dry weight, were strongly related to Pb in test water at every time interval (7, 14, 21, and 28 days), and did not significantly increase after day 14. Hemolymph Pb concentration was variable, dependent on exposure concentration, and showed no appreciable change with time beyond day 7, except for mussels in the greatest exposure concentration (245 mu g/L), which showed a significant reduction in Pb by 28 days, suggesting a threshold for Pb binding or elimination in hemolymph at concentrations near 1000 mu g/g. The Na+, K+-ATPase activity in the gill tissue of mussels was significantly reduced by Pb on day 28 and was highly correlated with tissue Pb concentration (R2 = 0.92; P = 0.013). The Na+, K+-ATPase activity was correlated with reduced hemolymph Na+ concentration at the greatest Pb exposure when enzyme activity was at 30% of controls. Hemolymph Ca2+ concentration increased significantly in mussels from the greatest Pb exposure and may

A neuronal lactate uptake inhibitor slows recovery of extracellular ion concentration changes in the hippocampal CA3 region by affecting energy metabolism.

Science.gov (United States)

Angamo, Eskedar Ayele; Rösner, Joerg; Liotta, Agustin; Kovács, Richard; Heinemann, Uwe

2016-11-01

Astrocyte-derived lactate supports pathologically enhanced neuronal metabolism, but its role under physiological conditions is still a matter of debate. Here, we determined the contribution of astrocytic neuronal lactate shuttle for maintenance of ion homeostasis and energy metabolism. We tested for the effects of α-cyano-4-hydroxycinnamic acid (4-CIN), which could interfere with energy metabolism by blocking monocarboxylate-transporter 2 (MCT2)-mediated neuronal lactate uptake, on evoked potentials, stimulus-induced changes in K + , Na + , Ca 2+ , and oxygen concentrations as well as on changes in flavin adenine dinucleotide (FAD) autofluorescence in the hippocampal area CA3. MCT2 blockade by 4-CIN reduced synaptically evoked but not antidromic population spikes. This effect was dependent on the activation of K ATP channels indicating reduced neuronal ATP synthesis. By contrast, lactate receptor activation by 3,5-dihydroxybenzoic acid (3,5-DHBA) resulted in increased antidromic and orthodromic population spikes suggesting that 4-CIN effects are not mediated by lactate accumulation and subsequent activation of lactate receptors. Recovery kinetics of all ion transients were prolonged and baseline K + concentration became elevated by blockade of lactate uptake. Lactate contributed to oxidative metabolism as both baseline respiration and stimulus-induced changes in Po 2 were decreased, while FAD fluorescence increased likely due to a reduced conversion of FAD into FADH 2 These data suggest that lactate shuttle contributes to regulation of ion homeostatsis and synaptic signaling even in the presence of ample glucose. Copyright © 2016 the American Physiological Society.

The association effect of human serum albumin under different zinc ion concentrations studied by small angle of neutron scattering

International Nuclear Information System (INIS)

He Jian; Xu Yanping; Yang Tonghua; He Jintian; Li Lianzhi; Zhou Yongqia

1997-01-01

The microscopic parameters of the HSA-Zn 2+ , R g and I(0), are obtained directedly by small angle of neutron scattering (SANS) under different concentrations of zinc ion. Comparing with other relevant experimental results, e.g. equilibrium dialysis, we can determine and distinguish the apparent interactive subsequences into more detailed sub-actions, such as self-association, inter-association, disintegration and deconformation et al., or even certain combination of them, other than some indirect and microscopic results. Results obtained by SANS can qualitatively and readily interpret the characteristics from the viewpoint of microscopic process

Experimental study of ion-induced nucleation by radon decay

International Nuclear Information System (INIS)

He, F.; Hopke, P.K.

1993-01-01

In the environment, the presence of ions from natural radioactivity may increase the rate of new particle formation through ion-induced nucleation. A thermal diffusion cloud chamber (TDCC) has been built to experimentally study ion-induced nucleation where the ions are produced by gaseous radioactive sources. The critical supersaturation values and nucleation rates for methanol, ethanol, 1-propanol, and 1-butanol vapors on ions produced within the volume of the chamber by alpha decay of 222 Rn have been measured quantitatively at various radioactivity concentrations and supersaturations. The presence of ion tracks and the effect of an external electric field were also investigated. The alpha tracks and ion-induced nucleation formed by 222 Rn decay become visible at the critical supersaturation that is below the value needed for homogeneous nucleation. At this supersaturation, the nucleation rates increase substantially with increasing 222 Rn at low activity concentrations, but attain limiting values at higher concentrations. The experimental results indicate that the ionization by radon decay will promote ion-cluster formation and lower the free energy barriers. The formation of visible droplets is strongly dependent on the supersaturation. This study also confirms that the external electric field has a significant effect on the observed rates of nucleation

Sensor-actuator system for dynamic chloride ion determination.

Science.gov (United States)

de Graaf, Derk Balthazar; Abbas, Yawar; Gerrit Bomer, Johan; Olthuis, Wouter; van den Berg, Albert

2015-08-12

Chloride is a crucial anion for various analytical applications from biological to environmental applications. In order to measure the chloride ion concentration, a measurement system is needed which can detect this concentration for prolonged times reliably. Chronopotentiometry is a technique which does not need a long term stable reference electrode and is therefore very suitable for prolonged ion concentration measurements. As the used electrode might be fouled by reaction products, this work focuses on a chronopotentiometric approach with a separated sensing electrode (sensor) and actuating electrode (actuator). Both actuation and sensor electrode are made of Ag/AgCl. A constant current is applied to the actuator and will start the reaction between Ag and Cl-, while the resulting Cl- ion concentration change is observed through the sensor, which is placed close to the actuator. The time it takes to locally deplete the Cl- ions is called transition time. Experiments were performed to verify the feasibility of this approach. The performed experiments show that the sensor detects the local concentration changes resulting from the current applied to the actuator. A linear relation between the Cl- ion concentration and the square root of the transition time was observed, just as was predicted by theory. The calibration curves for different chips showed that both a larger sensor and a larger distance between sensor and actuator resulted in a larger time delay between the transition time detected at the actuator and the sensor. Copyright © 2015 Elsevier B.V. All rights reserved.

Dynamic electrochemical measurement of chloride ions

NARCIS (Netherlands)

Abbas, Yawar; de Graaf, Derk B.; Olthuis, Wouter; van den Berg, Albert

2016-01-01

This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver chloride electrode is used extensively for potentiometric measurement of chloride ions concentration in electrolyte. In this measurement,

Compact microwave ion source

International Nuclear Information System (INIS)

Leung, K.N.; Walther, S.; Owren, H.W.

1985-05-01

A small microwave ion source has been fabricated from a quartz tube with one end enclosed by a two grid accelerator. The source is also enclosed by a cavity operated at a frequency of 2.45 GHz. Microwave power as high as 500 W can be coupled to the source plasma. The source has been operated with and without multicusp fields for different gases. In the case of hydrogen, ion current density of 200 mA/cm -2 with atomic ion species concentration as high as 80% has been extracted from the source

Microfluidic systems with ion-selective membranes.

Science.gov (United States)

Slouka, Zdenek; Senapati, Satyajyoti; Chang, Hsueh-Chia

2014-01-01

When integrated into microfluidic chips, ion-selective nanoporous polymer and solid-state membranes can be used for on-chip pumping, pH actuation, analyte concentration, molecular separation, reactive mixing, and molecular sensing. They offer numerous functionalities and are hence superior to paper-based devices for point-of-care biochips, with only slightly more investment in fabrication and material costs required. In this review, we first discuss the fundamentals of several nonequilibrium ion current phenomena associated with ion-selective membranes, many of them revealed by studies with fabricated single nanochannels/nanopores. We then focus on how the plethora of phenomena has been applied for transport, separation, concentration, and detection of biomolecules on biochips.

Poster 29. Modelling of ion exchange processes in ultrapure water

International Nuclear Information System (INIS)

Berg, A.; Torstenfelt, B.; Fejes, P.; Foutch, G.L.

1992-01-01

The ion exchange process of the Reactor Water Clean-up (RWCU) system has been studied to better use the maximum possible exchange capacity of the ion exchange resin. Laboratory data have been correlated with computer simulations of the ion exchange process. Data were correlated using a mixed-bed ion exchange model for ultralow ionic concentrations developed at Oklahoma State University. Experimental results of the ion exchange column operation in the concentration range of 10 -3 M boric acid is compared with the simulated performance predicted by the computer model. The model is found to agree reasonably well with the data. (author)

Effect of argon ion beam voltages on the microstructure of aluminum nitride films prepared at room temperature by a dual ion beam sputtering system

International Nuclear Information System (INIS)

Chen, H.-Y.; Han Sheng; Cheng, C.-H.; Shih, H.C.

2004-01-01

Aluminum nitride (AlN) films were successfully deposited at room temperature onto p-type (1 0 0) silicon wafers by manipulating argon ion beam voltages in a dual ion beam sputtering (DIBS). X-ray diffraction spectra showed that aluminum nitride films could be synthesized above 800 V. The (0 0 2) orientation was dominant at 800 V, above which the orientation was random. The atomic force microscope (AFM) images displayed a relatively smooth surface with the root-mean-square roughness of 2-3 nm, where this roughness decreased with argon ion beam voltage. The Al 2p 3/2 and N 1s spectra indicated that both the aluminum-aluminum bond and aluminum-nitrogen bond appeared at 600 V, above which only the aluminum-nitrogen bond was detected. Moreover, the atomic concentration in aluminum nitride films was concentrated in aluminum-rich phases in all cases. Nevertheless, the aluminum concentration markedly increased with argon ion beam voltages below 1000 V, above which the concentration decreased slightly. The correlation between the microstructure of aluminum nitride films and argon ion beam voltages is also discussed

Ion implantation

International Nuclear Information System (INIS)

Johnson, E.

1986-01-01

It is the purpose of the present paper to give a review of surface alloy processing by ion implantation. However, rather than covering this vast subject as a whole, the survey is confined to a presentation of the microstructures that can be found in metal surfaces after ion implantation. The presentation is limited to alloys processed by ion implantation proper, that is to processes in which the alloy compositions are altered significantly by direct injection of the implanted ions. The review is introduced by a presentation of the processes taking place during development of the fundamental event in ion implantation - the collision cascade, followed by a summary of the various microstructures which can be formed after ion implantation into metals. This is compared with the variability of microstructures that can be achieved by rapid solidification processing. The microstructures are subsequently discussed in the light of the processes which, as the implantations proceed, take place during and immediately after formation of the individual collision cascades. These collision cascades define the volumes inside which individual ions are slowed down in the implanted targets. They are not only centres for vigorous agitation but also the sources for formation of excess concentrations of point defects, which will influence development of particular microstructures. A final section presents a selection of specific structures which have been observed in different alloy systems. (orig./GSCH)

Ion and electron heating in ICRF heating experiments on LHD

Energy Technology Data Exchange (ETDEWEB)

Saito, K. [Nagoya Univ. (Japan). Faculty of Engineering; Kumazawa, R.; Mutoh, T. [National Inst. for Fusion Science, Toki, Gifu (Japan)] [and others

2001-02-01

This paper reports on the Ion Cyclotron Range of Frequency (ICRF) heating conducted in 1999 in the 3rd experimental campaign on the Large Helical Device (LHD) with an emphasis on the optimization of the heating regime. Specifically, an exhaustive study of seven different heating regimes was carried out by changing the RF frequency relative to the magnetic field intensity, and the dependence of the heating efficiency on H-minority concentration was investigated. It was found in the experiment that both ion and electron heating are attainable with the same experimental setup by properly choosing the frequency relative to the magnetic field intensity. In the cases of both electron heating and ion heating, the power absorption efficiency depends on the minority ion concentration. An optimum minority concentration exists in the ion heating case while, in the electron heating case, the efficiency increases with concentration monotonically. A simple model calculation is introduced to provide a heuristic understanding of these experimental results. Among the heating regimes examined in this experiment, one of the ion heating regimes was finally chosen as the optimized heating regime and various high performance discharges were realized with it. (author)

Adsorption of heavy metal ions by sawdust of deciduous trees

International Nuclear Information System (INIS)

Bozic, D.; Stankovic, V.; Gorgievski, M.; Bogdanovic, G.; Kovacevic, R.

2009-01-01

The adsorption of heavy metal ions from synthetic solutions was performed using sawdust of beech, linden and poplar trees. The adsorption depends on the process time, pH of the solution, type of ions, initial concentration of metals and the sawdust concentration in suspension. The kinetics of adsorption was relatively fast, reaching equilibrium for less than 20 min. The adsorption equilibrium follows Langmuir adsorption model. The ion exchange mechanism was confirmed assuming that the alkali-earth metals from the adsorbent are substituted by heavy metal ions and protons. On lowering the initial pH, the adsorption capacity decreased, achieving a zero value at a pH close to unity. The maximum adsorption capacity (7-8 mg g -1 of sawdust) was achieved at a pH between 3.5 and 5 for all the studied kinds of sawdust. The initial concentration of the adsorbate and the concentration of sawdust strongly affect the process. No influence of particles size was evidenced. A degree of adsorption higher than 80% can be achieved for Cu 2+ ions but it is very low for Fe 2+ ions, not exceeding 10%.

Ion mobility spectrometry as a simple and rapid method to measure the plasma propofol concentrations for intravenous anaesthesia monitoring

Science.gov (United States)

Wang, Xin; Zhou, Qinghua; Jiang, Dandan; Gong, Yulei; Li, Enyou; Li, Haiyang

2016-11-01

The plasma propofol concentration is important information for anaesthetists to monitor and adjust the anaesthesia depth for patients during a surgery operation. In this paper, a stand-alone ion mobility spectrometer (IMS) was constructed for the rapid measurement of the plasma propofol concentrations. Without any sample pre-treatment, the plasma samples were dropped on a piece of glass microfiber paper and then introduced into the IMS cell by the thermal desorption directly. Each individual measurement could be accomplished within 1 min. For the plasma propofol concentrations from 1 to 12 μg mL-1, the IMS response was linear with a correlation coefficient R2 of 0.998, while the limit of detection was evaluated to be 0.1 μg mL-1. These measurement results did meet the clinical application requirements. Furthermore, other clinically-often-used drugs, including remifentanil, flurbiprofen and atracurium, were found no significant interference with the qualitative and quantitative analysis of the plasma propofol. The plasma propofol concentrations measured by IMS were correlated well with those measured by the high performance liquid chromatography (HPLC). The results confirmed an excellent agreement between these two methods. Finally, this method was applied to monitor the plasma propofol concentrations for a patient undergoing surgery, demonstrating its capability of anaesthesia monitoring in real clinical environments.

Electrochemical investigation on the effects of sulfate ion concentration, temperature and medium pH on the corrosion behavior of Mg–Al–Zn–Mn alloy in aqueous ethylene glycol

Directory of Open Access Journals (Sweden)

H. Medhashree

2017-03-01

Full Text Available The effects of sulfate ion concentration, temperature and medium pH on the corrosion of Mg–Al–Zn–Mn alloy in 30% aqueous ethylene glycol solution have been investigated by electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy methods. Surface morphology of the alloy was examined before and after immersing in the corrosive media by scanning electron microscopy (SEM and energy dispersion X-ray (EDX analysis. Activation energy, enthalpy of activation and entropy of activation were calculated from Arrhenius equation and transition state theory equation. The obtained results indicate that, the rate of corrosion increases with the increase in sulfate ion concentration and temperature of the medium and decreases with the increase in the pH of the medium.

Colorimetric detection of manganese(II) ions using gold/dopa nanoparticles.

Science.gov (United States)

Narayanan, Kannan Badri; Park, Hyun Ho

2014-10-15

We report here a one-pot, greener, eco-friendly strategy for the synthesis of gold nanoparticles using L-dopa. The as-prepared dopa-functionalized gold nanoparticles (AuNPs/dopa) can detect low concentrations of manganese(II) metal ions in aqueous solution. The binding forces between dopa and Mn(2+) ions cause dopa-functionalized gold nanoparticles to come closer together, decreasing the interparticle distance and aggregating it with a change in color of colloidal solution from red to purplish-blue. Dynamic light scattering (DLS) analysis showed a decreased surface charge on the surface of gold nanoparticles when exposed to Mn(2+) ions, which caused cross-linking aggregation. Transmission electron microscopic (TEM) images also revealed the aggregation of gold nanoparticles with the addition of Mn(2+) ions. The extinction ratio of absorbance at 700-550nm (A700/A550) was linear against the concentration of [Mn(2+)] ions. Thus, the optical absorption spectra of gold colloidal solution before and after the addition of Mn(2+) ions reveal the concentration of Mn(2+) ions in solution. Copyright © 2014 Elsevier B.V. All rights reserved.

Ion-ion and ion-solvent interactions in lithium imidazolide electrolytes studied by Raman spectroscopy and DFT models.

Science.gov (United States)

Scheers, Johan; Niedzicki, Leszek; Zukowska, Grażyna Z; Johansson, Patrik; Wieczorek, Władysław; Jacobsson, Per

2011-06-21

Molecular level interactions are of crucial importance for the transport properties and overall performance of ion conducting electrolytes. In this work we explore ion-ion and ion-solvent interactions in liquid and solid polymer electrolytes of lithium 4,5-dicyano-(2-trifluoromethyl)imidazolide (LiTDI)-a promising salt for lithium battery applications-using Raman spectroscopy and density functional theory calculations. High concentrations of ion associates are found in LiTDI:acetonitrile electrolytes, the vibrational signatures of which are transferable to PEO-based LiTDI electrolytes. The origins of the spectroscopic changes are interpreted by comparing experimental spectra with simulated Raman spectra of model structures. Simple ion pair models in vacuum identify the imidazole nitrogen atom of the TDI anion to be the most important coordination site for Li(+), however, including implicit or explicit solvent effects lead to qualitative changes in the coordination geometry and improved correlation of experimental and simulated Raman spectra. To model larger aggregates, solvent effects are found to be crucial, and we finally suggest possible triplet and dimer ionic structures in the investigated electrolytes. In addition, the effects of introducing water into the electrolytes-via a hydrate form of LiTDI-are discussed.

The role of ion-induced aerosol formation in the lower atmosphere

International Nuclear Information System (INIS)

Raes, Frank; Janssens, Augustin; Dingenen, Rita van

1986-01-01

The rate of ion-induced aerosol formation in a H 2 0-H 2 S0 4 mixture depends on the relative humidity, the relative acidity and the number of ions (clusters) available for nucleation. Figure 1 shows the rates of homogeneous and ion-induced aerosol formation as a function of the H 2 S0 4 sup((gas)) concentration, for conditions prevailing in the lower atmosphere. The rate of ion-induced aerosol formation is plotted for different concentrations of pre-existing aerosol. It can be seen that ion-induced aerosol formation will only play a role in the formation of new particles when (1) the H 2 S0 4 sup((gas)) concentration is confined within the critical values for ion-induced and homogeneous aerosol formation (about 5 x 10 7 and 4 x 10 8 cm -3 respectively), and (2) the concentration of pre-existing aerosol is lower than about 5 x 10 3 cm -3 (Dp = 0.1 μm). It will be shown by numerical calculations that such conditions may be expected above the oceans. (author)

Removal of Cobalt Ion by Adsorbing Colloidal Flotation

Energy Technology Data Exchange (ETDEWEB)

Jung, In Ha; Lee, Jung Won [Korea Atomic Energy Research Institute, Taejon (Korea)

1998-09-30

Simulated waste liquid containing 50 ppm cobalt ion was treated by adsorbing colloidal flotation using Fe(III) or Al(III) as flocculant and a sodium lauryl sulfate as a collector. Parameters such as pH, surfactant concentration, Fe(III) or Al(III) concentration, gas flow rate, etc., were considered. The flotation with Fe(III) showed 99.8% removal efficiency of cobalt on the conditions of initial cobalt ion concentration 50 ppm, pH 9.5, gas flow rate 70 ml/min, and flotation time 30 min. When the waste solution was treated with 35% H{sub 2}O{sub 2} prior to adsorbing colloidal flotation, the optimal pH for removing cobalt shifted to weak alkaline range and flotation could be applied in wider range of pH as compared to non-use of H{sub 2}O{sub 2}. Additional use of 20 ppm Al(III) after precipitation of 50 ppm Co(II) with 50 ppm Fe(III) made the optimal pH range for preferable flotation wider. Foreign ions such as, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, Ca{sup 2+} were adopted and their effects were observed, Of which sulfate ion was found to be detrimental to removal of cobalt ion by flotation. Coprecipitation of Co ion with Fe(III) and Al(III) resulted in better removal efficiency of cobalt ion in the presence of sulfate ion. (author). 14 refs., 13 figs.

Nonlinear propagation of ion-acoustic solitary waves in relativistic ion-beam plasma with negative ions

International Nuclear Information System (INIS)

Singh, Kh.I.; Das, G.C.

1993-01-01

Soliton propagations are studied in a relativistic multicomponent ion-beam plasma through the derivation of Korteweg-deVries (K-dV) and modified K-dV (mK-dV) equations. A generalization of the mK-dV equation involving higher order nonlinearities gives a transitive link between the K-dV and mK-dV equations for isothermal plasma, and the validity of this generalized equation throughout the whole range of negative ion concentrations is investigated through the derivation of Sagdeev potential. Parallel discussion of various K-dV solitons enlightening the experimental implications is also made. (author). 22 refs

Mixed moderate thermophilic bioleaching of Cu, Mo and Re from molybdenite concentrate: effects of silver ion, medium and energy sources

Directory of Open Access Journals (Sweden)

Hadi Abdollahi

2017-12-01

Full Text Available This study evaluates the effects of different additives such as silver ion, medium and energy sources on the efficiency of mixed moderate thermophilic bioleaching approach to extract Cu, Mo and Re from molybdenite concentrate containing 0.98% Cu, 1.56% Fe, 53.84% Mo, and 0.055% Re. Molybdenite was the major phase of Mo-bearing mineral and chalcopyrite, covellite and pyrite were distinguished as minor phases. The higher copper extraction was obtained in tests with silver additives in all types and quantities rather than tests without silver ion. Kinetic of copper dissolution varied in these experiments and depended on the types and amounts of silver, and other supplemented additives such as ferric ion. There was no clear difference in the copper extraction by various culture media and 100% of Cu was dissolved after 30 days of treatment, using 50 mg/L of silver nitrate as additives. In the best condition and without silver additives, maximum 60% of copper was extracted even in the presence of energy sources such as sulfur, ferrous and ferric ions. In the most effective test with initial pH 1.57, 50 mg/L silver nitrate, and 50 g/L ferric sulfate, 100% of copper was dissolved in less than a week with highest kinetics rate. Molybdenum and rhenium extraction had the same tends with redox potential graph. By increasing the redox potential to the 550-600mV, molybdenite started to dissolve and finally, molybdenum and rhenium were extracted 2% and 9.53% in the best condition; respectively.

Electrodialytic separation of alkali-element ions with the aid of ion-exchange membranes

International Nuclear Information System (INIS)

Gurskii, V.S.; Moskvin, L.N.

1988-01-01

Electrodialytic separation of ions bearing charges of the same sign with the aid of ion-exchange membranes has been examined in the literature in relation to the so-called ideal membranes, which do not exhibit selectivity with respect to one ion type in ion exchange. It has been shown that separation on such membranes is effective only for counterions differing in size of charge. A matter of greater importance from the practical standpoint is the possibility of using electrodialysis for separating ions bearing like charges and having similar properties, including ionic forms of isotopes of the same element. In this paper they report a comparative study of ion separation, with reference to the Cs-Na pair, by electrodialysis through various types of cation-exchange membranes. Changes of the solution concentration in the cathode compartment were monitored by measurement of 22 Na and 137 Cs activities

Synthesis, characterization and antifungal efficacy of C-coordinated O-carboxymethyl chitosan Cu(II) complexes.

Science.gov (United States)

Liu, Weixiang; Qin, Yukun; Liu, Song; Xing, Ronge; Yu, Huahua; Chen, Xiaolin; Li, Kecheng; Li, Pengcheng

2017-03-15

A novel type of O-carboxymethyl chitosan Schiff bases (O-CSPX) was synthesized via a condensation reaction. After the coordination reaction of cupric ions, Cu(II) complexes (O-CSPX-Cu) were achieved. The theoretical structure of O-CSPX-Cu calculated by Gaussian 09 reveals that the copper ions underwent dsp 2 hybridization, coordinated by the carbon atom in the p-π conjugate group and the oxygen atoms in the acetate ion. Then, the structures were confirmed by FT-IR, 1 H NMR, CP-MAS 13 C NMR, elemental analysis, DSC and XRD. The antifungal properties of O-CSPX-Cu against Phytophthora capsici (P. capsici), Gibberella zeae (G. zeae) and Glomerella cingulata (G. cingulata) were evaluated at concentrations ranging from 0.05mg/mL to 0.20mg/mL. The experiments indicated that the derivatives have significantly enhanced antifungal activity after copper ion complexation compared with the original chitosan. Moreover, it was shown that 0.20mg/mL of O-CSP3-Cu and O-CSP4-Cu can 100% inhibit the growth of P. capsici. The experimental results reveal that the antifungal efficiency is related to the space steric hindrance on the benzene ring, which may provide a novel direction for the development of copper fungicides. Copyright © 2016 Elsevier Ltd. All rights reserved.

''Spray'' drying unit for spent ion-exchange resins sludges and radioactive concentrates

International Nuclear Information System (INIS)

Raibaud, J.

1985-01-01

The procedure consisting in drying radwaste either in liquid form or in aqueous suspension is a very attractive solution for volume Reduction. Technicatome presents an experimental spray drying station for 50 kg/hr, using the LEAFLASH process, developed by Rhone Poulenc Recherches. This process, used at full scale in a large number of branches in industry, is applicable to the drying of various materials: bead type ion-echange resins, powered ion exchange resins, centrifuge sludges, filter sludges, evaporator bottoms [fr

Ion acoustic waves in pair-ion plasma: Linear and nonlinear analyses

International Nuclear Information System (INIS)

Saeed, R.; Mushtaq, A.

2009-01-01

Linear and nonlinear properties of low frequency ion acoustic wave (IAW) in pair-ion plasma in the presence of electrons are investigated. The dispersion relation and Kadomtsev-Petviashvili equation for linear/nonlinear IAW are derived from sets of hydrodynamic equations where the ion pairs are inertial while electrons are Boltzmannian. The dispersion curves for various concentrations of electrons are discussed and compared with experimental results. The predicted linear IAW propagates at the same frequencies as those of the experimentally observed IAW if n e0 ∼10 4 cm -3 . It is found that nonlinear profile of the ion acoustic solitary waves is significantly affected by the percentage ratio of electron number density and temperature. It is also determined that rarefactive solitary waves can propagate in this system. It is hoped that the results presented in this study would be helpful in understanding the salient features of the finite amplitude localized ion acoustic solitary pulses in a laboratory fullerene plasma.

Effect of Nitrite Ions on Steel Corrosion Induced by Chloride or Sulfate Ions

Directory of Open Access Journals (Sweden)

Zhonglu Cao

2013-01-01

Full Text Available The influence of nitrite concentration on the corrosion of steel immersed in three simulated pH environments containing chloride ions or sulfate ions has been investigated by comparing and analyzing the change of half-cell potential, the change of threshold level of Cl- or SO42-, the change of threshold level of NO2-/Cl- or NO2-/SO42- mole ratio, and the changes of anodic/cathodic polarization curves and Stern-Geary constant B. The corrosivity of chloride ions against sulfate ions also has been discussed in pH 12.6, pH 10.3, and pH 8.1 environments containing 0, 0.053, and 0.2 mol/L NO2, respectively.

Europium ion as a probe for binding sites to carrageenans

International Nuclear Information System (INIS)

Ramos, Ana P.; Goncalves, Rogeria R.; Serra, Osvaldo A.; Zaniquelli, Maria Elisabete D.; Wong, Kenneth

2007-01-01

Carrageenans, sulfated polysaccharides extracted from red algae, present a coil-helix transition and helix aggregation dependence on the type and concentration of counterions. In this study, we focus attention on a mixed valence counterion system: Eu 3+ /Na + or K + with different gel-forming carrageenans: kappa, iota, and kappa-2. Results of stationary and time-dependent luminescence showed to be a suitable tool to probe ion binding to both the negatively charged sulfate group and the hydroxyl groups present in the biopolymer. For lower europium ion concentrations, a single longer decay emission lifetime was detected, which was attributed to the binding of europium ion to the carrageenan sulfate groups. An additional decay ascribed to europium binding to hydroxyl groups was observed above a threshold concentration, and this decay was dependent on the carrageenan charge density. Symmetry of the europium ion microenvironment was estimated by the ratio between the intensities of its emission bands, which has been shown to depend on the concentration of europium ions and on the specificity of the monovalent counterion bound to the carrageenan

Europium ion as a probe for binding sites to carrageenans

Energy Technology Data Exchange (ETDEWEB)

Ramos, Ana P.; Goncalves, Rogeria R.; Serra, Osvaldo A. [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo 14040-901 (Brazil); Zaniquelli, Maria Elisabete D. [Departamento de Quimica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo 14040-901 (Brazil)], E-mail: medzaniquelli@ffclrp.usp.br; Wong, Kenneth [Laboratorio de Fisico-Quimica, Centro de Pesquisas de Paulinia, Rhodia Brasil, Paulinia, Sao Paulo (Brazil)

2007-12-15

Carrageenans, sulfated polysaccharides extracted from red algae, present a coil-helix transition and helix aggregation dependence on the type and concentration of counterions. In this study, we focus attention on a mixed valence counterion system: Eu{sup 3+}/Na{sup +} or K{sup +} with different gel-forming carrageenans: kappa, iota, and kappa-2. Results of stationary and time-dependent luminescence showed to be a suitable tool to probe ion binding to both the negatively charged sulfate group and the hydroxyl groups present in the biopolymer. For lower europium ion concentrations, a single longer decay emission lifetime was detected, which was attributed to the binding of europium ion to the carrageenan sulfate groups. An additional decay ascribed to europium binding to hydroxyl groups was observed above a threshold concentration, and this decay was dependent on the carrageenan charge density. Symmetry of the europium ion microenvironment was estimated by the ratio between the intensities of its emission bands, which has been shown to depend on the concentration of europium ions and on the specificity of the monovalent counterion bound to the carrageenan.

Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice

OpenAIRE

Boudreau, Thomas F.; Peck, Gregory M.; O'Keefe, Sean F.; Stewart, Amanda C.

2017-01-01

Abstract Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple (Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest f...

Ion measurements in premixed methane-oxygen flames

KAUST Repository

Alquaity, Awad; Hourani, Nadim; Chahine, May; Selim, Hatem; Sarathy, Mani; Farooq, Aamir

2014-01-01

Mass Spectrometer (MBMS) is utilized to measure ion concentration profiles in premixed methane-oxygen-argon burner-stabilized flames. Lean, stoichiometric and rich flames at atmospheric pressure are used to study the dependence of ion chemistry

The co-effect of collagen and magnesium ions on calcium carbonate biomineralization

International Nuclear Information System (INIS)

Jiao Yunfeng; Feng Qingling; Li Xiaoming

2006-01-01

The process of calcium carbonate biomineralization in the solution containing collagen and magnesium ions was studied in this paper. The results were characterized by using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect rules were obtained by the cooperation of collagen and magnesium ions in different concentration. The experiment results showed that in the presence of both collagen and magnesium ions, aragonite and vaterite were precipitated at low Mg/Ca ion concentration ratio, while only aragonite with regular spherical morphology was precipitated at high Mg/Ca ion concentration ratio. It indicated that collagen has a promotional effect on magnesium ions in controlling the polymorph of calcium carbonate crystal. A much wider range of calcium carbonate morphologies was observed in the presence of both collagen and magnesium ions. The experiments suggested that collagen acts in combination with magnesium ions to inhibit calcite crystal growth, while favoring the formation of aragonite crystals

Removal of Cobalt ion by Foam Flotation(I)

Energy Technology Data Exchange (ETDEWEB)

Jung, I.H.; Park, H.S.; Moon, J.S.; Yim, S.P.; Bae, K.K. [Korea Atomic Energy Research Institute (Korea)

1999-02-01

Simulated liquid waste containing 50 ppm cobalt ion was treated by precipitate flotation using the surfactant of sodium lauryl sulfate. The effects of initial cobalt ion concentration, pH, surfactant concentration, removal time, gas flow rate and foreign ions were estimated on removal efficiency. 35% H{sub 2}O{sub 2} was added for pre-treatment stage before precipitate flotation. As the result of pre-treatment, optimum removal pH and the pH of treated water being discharged were lowed and optimum removal pH range was broadened. For the result of this experiment, 99.8% removal efficiency was obtained at the condition of 50ppm of initial cobalt ion concentration, pH 9.5, 70 mL/min of gas flow rate, and 30 min of removal time. Attraction between precipitate and surfactant was supposed to be influenced by solubility and chemical affinity among species in solution as well as zeta potential. The influence of foreign ions such as, NO{sub 3}{sup -}, SO{sub 4}{sup -2}, Na{sup +}, Ca{sup +2} on the removal efficiency was also observed. Removal efficiency by precipitate flotation containing o.1 M of SO4{sup -}2 ion decreased to 90% due to the decrease of zeta potential and interruption of precipitation. 12 refs., 8 figs.

Ion implantation: an annotated bibliography

International Nuclear Information System (INIS)

Ting, R.N.; Subramanyam, K.

1975-10-01

Ion implantation is a technique for introducing controlled amounts of dopants into target substrates, and has been successfully used for the manufacture of silicon semiconductor devices. Ion implantation is superior to other methods of doping such as thermal diffusion and epitaxy, in view of its advantages such as high degree of control, flexibility, and amenability to automation. This annotated bibliography of 416 references consists of journal articles, books, and conference papers in English and foreign languages published during 1973-74, on all aspects of ion implantation including range distribution and concentration profile, channeling, radiation damage and annealing, compound semiconductors, structural and electrical characterization, applications, equipment and ion sources. Earlier bibliographies on ion implantation, and national and international conferences in which papers on ion implantation were presented have also been listed separately

USE OF SILVER IONS IN PASTEURIZED MILK PRODUCTION

Directory of Open Access Journals (Sweden)

A. Mamaev

2012-10-01

Full Text Available The means of pasteurized milk shelf life prolongation by electro-chemical diffusion of silver ions has been introduced. Three samples of pasteurized milk were test subjects. In the course of study the following data have been examined: organoleptic, physicochemical, microbiological parameters of check samples and pilot samples of raw and pasteurized milk. Its shelf life has been determined. It has been determined that the test results of raw and pasteurized milk samples processed by various concentration of silver ions showed minor difference in organoleptic, physic-chemical, microbiological parameters and shelf life span. In this connection it appears reasonable to use the smallest concentration of silver ions - 50 micrograms per liter for milk shelf life prolongation as it is considered the least harmful for person's organism. Infusion of silver ions in the concentration of 50 micrograms per liter allows to prolong raw and pasteurized milk shelf life by two days.

Selectivity coefficients of ion-selective magnesium electrodes used for simultaneous determination of magnesium and calcium ions.

Science.gov (United States)

Maj-Zurawska, Magdalena; Lewenstam, Andrzej

2011-12-15

Membrane ion-selective magnesium electrodes are commonly used to determine ionized magnesium concentration in blood serum and intracellular fluid by potentiometric clinical analyzers. The selectivity of these electrodes against calcium ion is typically insufficient to avoid calcium interference in blood serum analysis. For this reason the selectivity coefficient for calcium ion has to be studied to make possible any mathematical corrections for calcium ion influence. Existing methods relate to the thermodynamic concept of ISE response which suggest a single constant value of the selectivity coefficient and slope that are stable over the concentration ranges of calcium and magnesium ions in the samples. Unfortunately, this rarely happens, and we rather observe dependences on solution and membrane composition, readout time, matrices (anticoagulant, vial coats) that justify usage of apparent selectivities and slopes. To get the practical insight into the response of magnesium ion-selective electrodes a novel method for estimating the selectivity coefficients and the slope of the electrode characteristics is proposed. This method is an effective starting point for selecting electrodes and designing transient signal software in a potentiometric clinical analyzer. The method allows obtaining the ionized magnesium concentration in blood serum with minimal possible error by addressing the assessed targets, i.e. apparent selectivity and slope. The method is based on computer simulation and on the Nicolsky-Eisenman equation. Usually only a few iterations are needed to obtain stable congruent results. The method presented is particularly useful in conditions where is not possible to obtain calibration curve, which is typical for clinical analyzer where at most three point calibration is performed. Copyright © 2011 Elsevier B.V. All rights reserved.

Calcium ion binding to a soil fulvic acid using a Donnan Potential model

International Nuclear Information System (INIS)

Marinsky, J.A.

1999-01-01

Calcium ion binding to a soil fulvic acid (Armadale Bh Horizon) was evaluated over a range of calcium ion concentrations, from pH 3.8 to 7.3, using potentiometric titrations and calcium ion electrode measurements. Fulvic acid concentration was constant (100 milligrams per liter) and calcium ion concentration varied up to 8 x 10 -4 moles per liter. Experiments discussed here included: (1) titrations of fulvic acid-calcium ion containing solutions with sodium hydroxide; and (2) titrations of fully neutralized fulvic acid with calcium chloride solutions. Apparent binding constants (expressed as the logarithm of the value, log β app ) vary with solution pH, calcium ion concentration, degree of acid dissociation, and ionic strength (from log β app =2.5 to 3.9) and are similar to those reported by others. Fulvic acid charge, and the associated Donnan Potential, influences calcium ion-fulvic acid ion pair formation. A Donnan Potential correction term allowed calculation of intrinsic calcium ion-fulvic acid binding constants. Intrinsic binding constants vary from 1.2 to 2.5 (the average value is about log β=1.6) and are similar to, but somewhat higher than, stability constants for calcium ion-carboxylic acid monodentate complexes. (orig.)

Investigation on degradation mechanism of ion exchange membrane immersed in highly concentrated tritiated water under the Broader Approach Activities

Energy Technology Data Exchange (ETDEWEB)

Iwai, Yasunori, E-mail: iwai.yasunori@jaea.go.jp; Sato, Katsumi; Yamanishi, Toshihiko

2014-10-15

Highlights: • Endurance of Nafion ion exchange membrane immersed into 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water has been demonstrated. • The formation of free hydrophobic free products by reactions between radicals on the membrane and oxygen caused the decrease in ionic conductivity. • From the {sup 19}F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured. - Abstract: The ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Durability of ion exchange membrane has been demonstrated under the Broader Approach Activities. Long-term exposure of Nafion{sup ®} ion exchange membrane in 1.38 × 10{sup 12} Bq/kg of tritiated water was conducted at room temperature for up to 2 years. The ionic conductivity of Nafion{sup ®} membrane after immersed in tritiated water was changed. The change in color of membrane from colorless to yellowish was caused by reactions of radicals on the polymer and oxygen molecules in air. Infrared Fourier transform spectrum of a yellowish membrane revealed a small peak for bending vibration of C-H situated at 1437 cm{sup −1}, demonstrating the formation of hydrophobic functional group in the membrane. The hydrophilic network in Nafion{sup ®} membrane was partially obstructed by the hydrophobic free products. This caused the decrease in ionic conductivity. The peak for bending vibration was clearly eliminated in the spectrum of the membrane after treatment by acid for removal of free products. The high-resolution solid state {sup 19}F NMR spectrum of a membrane after immersed in tritiated water was similar to that of a membrane irradiated with gamma-rays. From the {sup 19}F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured.

Investigation on degradation mechanism of ion exchange membrane immersed in highly concentrated tritiated water under the Broader Approach Activities

International Nuclear Information System (INIS)

Iwai, Yasunori; Sato, Katsumi; Yamanishi, Toshihiko

2014-01-01

Highlights: • Endurance of Nafion ion exchange membrane immersed into 1.38 × 10 12 Bq/kg of highly concentrated tritiated water has been demonstrated. • The formation of free hydrophobic free products by reactions between radicals on the membrane and oxygen caused the decrease in ionic conductivity. • From the 19 F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured. - Abstract: The ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Durability of ion exchange membrane has been demonstrated under the Broader Approach Activities. Long-term exposure of Nafion ® ion exchange membrane in 1.38 × 10 12 Bq/kg of tritiated water was conducted at room temperature for up to 2 years. The ionic conductivity of Nafion ® membrane after immersed in tritiated water was changed. The change in color of membrane from colorless to yellowish was caused by reactions of radicals on the polymer and oxygen molecules in air. Infrared Fourier transform spectrum of a yellowish membrane revealed a small peak for bending vibration of C-H situated at 1437 cm −1 , demonstrating the formation of hydrophobic functional group in the membrane. The hydrophilic network in Nafion ® membrane was partially obstructed by the hydrophobic free products. This caused the decrease in ionic conductivity. The peak for bending vibration was clearly eliminated in the spectrum of the membrane after treatment by acid for removal of free products. The high-resolution solid state 19 F NMR spectrum of a membrane after immersed in tritiated water was similar to that of a membrane irradiated with gamma-rays. From the 19 F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured

Metallic ions in the upper atmosphere

International Nuclear Information System (INIS)

Kumar, S.

1979-01-01

During the past 20 years considerable progress has been made in establishing the presence of metallic ions in the sporadic E layers at mid latitudes and as discrete patches at high altitudes in the equatorial ionosphere. The E-region observations have been based on rocket flights, which represent local conditions faithfully. But the global distribution of metallic ions and variations relating to changes in season, local time, magnetic activity, etc., which require satellite data, have been largely unexamined. This work presents a few aspects of this missing global distribution over an altitude range of 100 to 1000 km, using the data from AE-C, AE-D, and OGO-6 satellites and the rocket flights 18.117 and 18.118 from Wallops Island on July 12 and 13, 1971. The rocket data provide a day-night pair of vertical profiles that include altitudes not covered by the satellites. Results are presented for Mg + , Al + , Si + and Fe + ions in terms of their detection probabilities, median concentrations and relative abundances with respect to Mg + ions as a function of significant geophysical parameters. Na + and K + ions have been excluded from this study because alkali metal ions driven off the spacecraft hamper the measurement of ambient Na + and K + ions. This study has indicated that in general different metallic ions appear together in comparable concentrations except for Al + , which is an order of magnitude smaller than the others

Removal of adsorbent particles od copper ions by Jet flotation; Remocion de particulas adsorbentes de iones cobre por flotacion Jet

Energy Technology Data Exchange (ETDEWEB)

Santander, M.; Tapia, P.; Pavez, O.; Valderrama, L.; Guzman, D.

2009-07-01

The present study shows the results obtained on the removal of copper ions from synthetic effluents by using the adsorbent particles flotation technique (APF) in a Jet flotation cell (Jameson type). In a typical experimental run, a mineral with high quartz content was used as adsorbent particles in the adsorption and flotation experiments, to determine optimal pH conditions, adsorbent particles concentration; flotation reagents dosage and air/effluent flow ratio for applying in the Jet cell to maximize the efficiency of copper ions adsorptions and the removal of particles adsorbents containing the absorbed copper ions. The results indicate the at pH>7 and at adsorbent particles concentration of 2 kg.m{sup -}3, 99% of copper ions is adsorbed and, when the air/effluent flow ratio applied in the Jet cell is 0,2, 98% of absorbent particles containing the adsorbed copper ions is removed. (Author) 39 refs.

Removal of copper ions from aqueous solutions by means of micellar-enhanced ultrafiltration

Directory of Open Access Journals (Sweden)

Kowalska Izabela

2017-01-01

Full Text Available The aim of the study was to assess the usefulness of micellar–enhanced ultrafiltration (MEUF for removal of copper ions from water solutions in comparison with classic ultrafiltration process. The tests were conducted in a semi–pilot membrane installation with the use of ultrafiltration module KOCH/ROMICON® at a transmembrane pressure of 0.05 MPa. The effect of concentration of copper ions on ultrafiltration process efficiency was investigated. The second part of the tests concerned the removal of copper ions by MEUF under wide range of anionic surfactant concentration (0.25, 1, and 5 CMC (critical micelle concentration. Concentration of copper ions in model solutions was equal to 5, 20, and 50 mg Cu/L. Furthermore, the effect of surfactant leakage to the permeate side during filtration was evaluated. Conducted experiments confirmed effectiveness of MEUF in copper ions removal. For the highest copper concentration in the feed (i.e. 50 mg/L, the average concentration of copper ions in the permeate ranged from 1.2–4.7 mg Cu/L depending on surfactant concentration. During filtration experiments, UF module exhibited stable transport properties for model solutions containing copper. For the highest concentration of metal, the decrease of permeate flux did not exceed 11% after 60 minutes of filtration. In the presence of the surfactant, a slight deterioration of transport properties was observed.

The DC Electrical Resistivity Curves of Bismuth-2212 Ceramic Superconductors: Evaluation of the Hole-Carrier Concentrations per-Cu Ion

Directory of Open Access Journals (Sweden)

nurmalita .

2016-04-01

Full Text Available In this study the samples of Bismuth ceramic superconductors were synthesized by the melt textured growth methods from a 2212 stoichiometric composition in order to obtain a large amount of pure Bi-2212. The effects of Pb substitution on the properties of Bi-based Bi2−xPbxSr2CaCu2Oy superconductor with x = 0, 0.2, and 0.4 were investigated by means of DC electrical resistivity measurements. It has been found that the hole-carrier concentrations per-Cu ion of the samples change independently of Pb content.

Solution chemistry and separation of metal ions in leached solution

International Nuclear Information System (INIS)

Shibata, J.

1991-01-01

The method to presume a dissolved state of metal ions in an aqueous solution and the technology to separate and concentrate metal ions in a leached solution are described in this paper. It is very important for the separation of metal ions to know the dissolved state of metal ions. If we know the composition of an aqueous solution and the stability constants of metal-ligand complexes, we can calculate and estimate the concentration of each species in the solution. Then, we can decide the policy to separate and concentrate metal ions. There are several methods for separation and purification; hydroxide precipitation method, sulfide precipitation method, solvent extraction method and ion exchange resin method. Solvent extraction has been used in purification processes of copper refinery, uranium refinery, platinum metal refinery and rare earth metal refinery. Fundamental process of solvent extraction, a kind of commercial extractants, a way of determining a suitable extractant and an equipment are discussed. Finally, it will be emphasized how the separation of rare earths is improved in solvent extraction. (author) 21 figs., 8 tabs., 8 refs

Mass transport and chloride ion complexes in occluded cell

International Nuclear Information System (INIS)

Tsuru, T.; Hashimoto, K.; Nishikata, A.; Haruyama, S.

1989-01-01

Changes in the transport and the concentration of ions in a model occluded cell are traced during galvanostatic anodic polarization of a mild steel and a stainless steel. Apparent transport numbers of anions and cations, which were estimated from chemical analysis of solution, were different from those calculated from known mobility data. At the initial stage of the polarization, the transport number of chloride ion was almost unity, and then decreased gradually. For the mild steel, the concentration of total chloride ion accumulated in the occluded compartment increased with the anodic charge passed, and the amount of chloride ion complexed with cations also increased. The chloride complex was estimated as FeCl + . For SUS304 stainless steel, the total chloride ion increased, however, the free chloride ion, which responded to an Ag/AgCl electrode remained approximately 2 mol/dm 3 . Therefore, most of the chloride ions transferred into the occluded cell formed complex ions, such as CrCl n 3-n . The number of chloride ion coordinated to ferrous and chromic ions was estimated from the data fo mass transport for the case of the mild steel and the stainless steel. (author) 9 refs., 14 figs

Ion implantation and amorphous metals

International Nuclear Information System (INIS)

Hohmuth, K.; Rauschenbach, B.

1981-01-01

This review deals with ion implantation of metals in the high concentration range for preparing amorphous layers (>= 10 at%, implantation doses > 10 16 ions/cm 2 ). Different models are described concerning formation of amorphous phases of metals by ion implantation and experimental results are given. The study of amorphous phases has been carried out by the aid of Rutherford backscattering combined with the channeling technique and using transmission electron microscopy. The structure of amorphous metals prepared by ion implantation has been discussed. It was concluded that amorphous metal-metalloid compounds can be described by a dense-random-packing structure with a great portion of metal atoms. Ion implantation has been compared with other techniques for preparing amorphous metals and the adventages have been outlined

The obtaining a high-grade gadolinium concentrate

International Nuclear Information System (INIS)

Soltysiak, I.; Ozga, W.

1982-01-01

Gadolinium concentrates obtained by the fractional precipitation of lanthanon-potassium double chromates were separated by ion exchange with 0,4 M lactic acid solution in the presence of 0,1 M ammonium nitrate at pH of the medium 2,95-3,4. It was found out, that using the fractional precipitation of lanthanon-potassium double chromates (as the fast and cheap method that does not need special equipment) together with ion exchange separation with lactic acid solution as the eluent gave a highgrade gadolinium concentrate in a quick and economical way. (author)