Diffuse sorption modeling: Ionic adsorption on silica.

The Poisson-Boltzmann equation was applied to simulation of published data on adsorption of bivalent metal ions on silica. The surface charge of silica was approximated with the basic Stern model (without coordinate binding of sodium ions). It was found that the adsorption of alkaline-earth metal ions is closely consistent with the Poisson-Boltzmann equation; i.

90Sr in mammal teeth from contaminated areas in the former Soviet Union measured by imaging plates.

Imaging plates sensitive to beta rays were used to obtain the images of 90Sr in tooth samples taken from mammals collected in contaminated areas of the former Soviet Union. The average concentrations of 90Sr in the samples were determined by comparing the intensities of the luminescence using a single crystal of KCl. The results showed that the determined 90Sr concentration has a positive correlation with the soil contamination levels in the South Ural region.

Diffuse sorption modeling: apparent H/Na, or the same, Al/Na exchange on clays.

Clay minerals are specified by permanent negative surface charge. In solutions of sodium salts, the surface of clay is covered by exchangeable sodium ions. In an acidic field (pH<4-6), sodium ions are displaced from the surface.

Diffuse sorption modeling.

This work presents a simple solution for the diffuse double layer model, applicable to calculation of surface speciation as well as to simulation of ionic adsorption within the diffuse layer of solution in arbitrary salt media. Based on Poisson-Boltzmann equation, the Gaines-Thomas selectivity coefficient for uni-bivalent exchange on clay, K(GT)(Me(2+)/M(+))=(Q(Me)(0.5)/Q(M)){M(+)}/{Me(2+)}(0.

Adsorption of ions onto amorphous silica: ion exchange model.

Single site ion exchange model was applied for description of the published data on adsorption of sodium, calcium, cadmium, and zinc onto amorphous silica. The following equilibria were detected (25 degrees C; X-adsorption site; TotX=6 micromol/m2): 2X + Na+ OH* <=> XNa+ XOH*, log K degree = 5.1, 3X + Me2+ +2OH*<=> XMe2+ 2XOH*, log K degree = 11.

[Regional anesthesia and sedation during extremity operations in children].

Twenty-five studies were made in patients aged 12 to 15 years, who had been operated on for extremity injuries. The patients were divided into 2 groups: (1) those who had been given regional anesthesia with sedation (n=10) and (2) those who had received apparatus-mask anesthesia (n=15). The following parameters: heart rate, blood pressure, stroke volume, cardiac output were estimated.

The Third International Intercomparison on EPR Tooth Dosimetry: part 2, final analysis.

The objective of the Third International Intercomparison on EPR Tooth Dosimetry was to evaluate laboratories performing tooth enamel dosimetry <300 mGy. Final analysis of results included a correlation analysis between features of laboratory dose reconstruction protocols and dosimetry performance. Applicability of electron paramagnetic resonance (EPR) tooth dosimetry at low dose was shown at two applied dose levels of 79 and 176 mGy.

Modeling of ionic equilibria of trace metals (Cu2+, Zn2+, Cd2+) in concentrated aqueous electrolyte solutions at 25 degrees C.

This work presents a model of activity coefficients and a database for ionic equilibria of Cu2+, Zn2+, and Cd2+ in (H+, Na+, K+, Mg2+, Ca2+)(OH-, Cl-, NO-3, ClO-4, HSO-4, SO2-(4), HCO-3, CO(2-)3) aqueous media valid up to 6-12 m ionic strength. The activity coefficient of a dissolved species is represented by empirical equation [Formula: see text] , where Agamma is Debye-Hückel constant (1.17 at 25 degrees C), gammai and zi are activity coefficient and charge of a dissolved species i, I is molal ionic strength, bij is model parameter, and mj is molal concentration of dissolved species.

Dispersion of components in transport processes: velocity dispersion model.

This paper presents a new model of dispersion of components in transport processes. It is suggested that the flow velocity may be specified by a Gauss function with relative dispersion of flow velocity beta=sigmav/v; the overall dispersion of inert component (in porous as well as in homogeneous medium) may be calculated from the equation sigma=(2Dt/tau2 + (betavt)2)0.5, where D is the diffusion coefficient, t is time, tau is tortuosity, and v is flow velocity.

[Inhalational anesthesia during adenoidectomy in children].

The paper deals with the comparison of inhalational anesthesia using a fluoroethane-monooxide-oxygen mixture in apparatus-mask and endotracheal fashions in children during adenotomy. Children aged 4 to 15 years, who had undergone apparatus-mask (n = 51) and endotracheal (n = 57) anesthesia, were examined. The patients were divided into two age groups: 4-8 years and 8-15 years.

The 3rd international intercomparison on EPR tooth dosimetry: Part 1, general analysis.

The objective of the 3rd International Intercomparison on Electron Paramagnetic Resonance (EPR) Tooth Dosimetry was the evaluation of laboratories performing tooth enamel dosimetry below 300 mGy. Participants had to reconstruct the absorbed dose in tooth enamel from 11 molars, which were cut into two halves. One half of each tooth was irradiated in a 60Co beam to doses in the ranges of 30-100 mGy (5 samples), 100-300 mGy (5 samples), and 300-900 mGy (1 sample).

[The state of children in the early period after adenectomy].

Sixty-three children, aged 3 to 12, were examined after adenotomy made with general anesthesia. The parameters of central hemodynamics and of cardiointervalography describing the state of the vegetative nervous system as well as the postoperative clinical course were analyzed in children after adenotomy. A high sympathoadrenal activity with a trend to reduction was noted in children immediately after adenotomy.

[Changes in hemodynamics during regional anesthesia and medicinal sedation in children traumatology].

Thirty-nine patients, aged 8 to 15, who were operated for damaged bones in the upper lower limbs were examined. The parameters of central hemodynamics, heart rate and arterial pressure were studied (monitor HP "Viridia m3", USA). Strike volume was determined automatically (rheography monitor NCCOM-3"Boomed Co.

[Oral premedication in ambulatory surgical otorhinolaryngology in children].

34 children selected into two groups due to age (patients from 4 to 7 year old were included in the 1st group, the 2nd group consisted of children, aged from 8 years to 14 years, were premedicated with dormicum, and in other 37 patients standard premedication was applied. The state of cardiovascular system was estimated by means of indices of central hemodynamics and heart rate monitoring data. Every patient was examined both before and 30 minutes after premedication.

[Endothelin-1 level in the complicated course of myocardial infarction].

In the uncomplicated course of myocardial infarction (MI), the level of endothelin-1 (ET-1) comes to be increased beginning from day 1 and remains the same during the acute phase of the disease and gets decreased during the subacute phase. In MI presenting with parietal thrombosis, left ventricular aneurism, the level of ET-1 increases during the first period of 24 hours, increasing further toward the end of the acute phase, there being no decrease in the subacute phase. In MI presenting with pericardial effusion, an increase in the level of ET-1 is seen during the first period of 24 hours of the disease with no rise being recordable in peptide concentration during the acute and subacute phases.

[Inhalation anesthesia with halogen-containing anesthetics in children].

The study was carried out in 158 children aged 3-16 years operated on in an inpatient setting. The patients were divided into 3 groups with different types of induction narcosis: 1) ethrane inhalation up to 3 vol% and N2O with O2 in 1:1 ratio (56 pts); 2) fluothane up to 3.5 vol% and N2O with O2 in 2:1 ratio (87 pts), and 3) isoflurane inhalation up to 3 vol% and N2O with O2 in 1:1 ratio (15 children).

[Combined anesthesia with blockade of nn.dorsalis penis and inhalation anesthetics in surgery of the penis in children].

The studies were carried out in 21 patients with abnormalities of the penis (coronal and penile hypospadia, webbed penis) aged 5-15 years. Central hemodynamics, heart rate, and arterial pressure were evaluated at 6 stages of anesthesia and surgery. Premedication, induction, and maintenance anesthesia were carried out routinely.

[Clinical picture of awakening after general anesthesia with midazolam, propofol, ketamine and fluothane in children treated at one-day ambulatory facility].

The study was carried out in 75 children aged 6-12 years with the physical status ASA I. The operations were performed on the lymphadenoid throat ring in a one-day setting. Awakening after anesthesia was evaluated by the following parameters: time between the end of intervention and extubation of the trachea, opening the eyes when asked, transportation from the operation room into the ward, and first dialogue with the doctor.

Adsorption of Cadmium onto Hematite: Temperature Dependence.

Cadmium adsorption by hematite has been investigated at 25-100 degrees C. The evaluation of experimental data was made, using the three-plain ( identical withFe(+)ellipsis identical withFeO(-)ellipsiscounter plain) constant capacitance model. The structure of hematite surface and of cadmium complexes was also considered.

[Oral dormicum premedication of children in day surgery].

Thirty-four patients aged 5-14 years were observed, divided into age groups OF 5-8 and 8-14 years. Cardiovascular function was evaluated by central hemodynamic parameters and cardiointervalography. Changes in external respiration parameters were studied.

Surface Structure and Site Density of the Oxide-Solution Interface.

The site densities of the surface of different oxides and hydroxides have been calculated from crystallographic data. The following values for the common habits are recommended: 2.7 nm-2 (Corundum), 2.