Interactive vizualization of constructive solid geometry scenes on graphic processors

A ray-tracing algorithm for interactive visualization of very large and structurally complicated scenes presented in the constructive solid geometry (CSG) form is suggested. The algorithm is capable of visualizing such scenes in real time by using a graphic processor. As primitives, classical shapes and objects represented in an analytical form (in particular, second-order surfaces and implicit functions) are used. Unlike other similar algorithms, our algorithm produces the final image in a single pass and has no constraints on the maximum number of primitives and on the CSG tree depth. The key feature of the algorithm is a method for optimizing CSG models, which converts the input tree to an equivalent spatially coherent and well-balanced form (a completely balanced equivalent tree may not exist). The performance of visualization after applying the optimization technique is shown to depend on only the computational resource of the GPU (in contrast to multi-pass algorithms whose performance is restricted by memory capacity). It has been shown experimentally that our algorithm is capable of rendering CSG models consisting of more than a million CSG primitives with the tree depth up to 24.     

The impact of complexing agents on the processes of sorption treatment of waters containing uranium

The paper investigates the impact of complexing agents: disodium salts of ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA), acetic acid (NAc), fulvic acids (A), sodium carbonate (Na₂CO₃) on sorption of U(VI) with montmorillonite. We established a complex nature of the relationship between sorption values U(VI) and pH in the presence of complexing agents, which indicates the decisive role of the forms of finding uranium in water treated. By the value of an impact on the process of sorption of U(VI) with montmorillonite the investigation of the complexing agents may be arranged into the following series: EDTA > NTA > Na₂CO₃ > FA.     

Treatment of waters containing uranium with saponite clay

The article has investigated sorption of U(VI) on a smectite mineral—saponite from the Tashkinsk deposit in the Khmelnitsk region. The equilibrium in the U(VI)-saponite system sets in within 8 h. The relationship between sorption and the pH has a clear-cut maximum characteristic of uranium sorption on aluminum-silicates at the pH values 5.5–7. The U(VI) sorption isotherm on saponite is described by the Langmuir empirical equation. We have established the influence on the sorption process of complexation reagents (EDTA, carbonate ions, fulvic acids). Based on experimental data the possibility of using the sorption method with the employment of saponite for water treatment containing uranium is shown.     

Effects of EDTA and NTA on sorption of U(VI) on the clay fraction of soil

Sorption behavior of U(VI) is studied in model systems containing montmorillonite with various concentrations of humic acids on its surface and complexants (disodium salts of ethylenediaminetetraacetic and nitrilotriacetic acids). Humic acids deposited onto the surface of montmorillonite enhance the U(VI) sorption at pH <7.0. The effect of complexants on the U(VI) sorption is rather intricate because of the possibility of formation of some surface uranium complexes, whose nature depends on the nature and concentration of the complexant in solution, pH, and humic acid concentration on the surface of montmorillonite.     

Effect of fulvic acids on Th(IV) sorption on montmorillonite

The effect of fulvic acids on Th(IV) sorption on montmorillonite is studied. Over the pH range 3.0–7.0, the sorption decreases as a result of formation of fulvate and hydroxofulvate complexes. The composition and formation constants of mixed Th(IV) hydroxofulvates are estimated using mathematical simulation. In acidic solutions, Th fulvates are partially sorbed on montmorillonite.     

Treatment of radioactively contaminated waters with an increased content of salts

The article gives a comparison characteristic of purifying highly mineralized radioactively contaminated mine waters by different methods. It is shown that the use of the coagulation method does not ensure purification to the MAC standards, while the sorption-coagulation method requires additional conditioning of spent sludge. For complex purification of mine waters (of the uranium compounds and partially of hardness salts) the reagent-magnetic method was proposed with the use of iron(II) and (III) salts, alkaline reagent CaO and natural magnetite.     

Semiologic, biochemical and electrophysiologic analysis of the stages of apopleptic coma

The paper contains some results of a comprehensive clinical, biochemical and electrophysiological study of 120 patients with different stages of an apoplectic coma. The authors studied the gas content, acid-base balance of the cranial blood inflow and outflow in the CSF and changes of EEG and EMG. It was shown that there were different levels of CNS lesions (cortico-subcortical, meso-diencephalic, meso-pontile and bulbar level) which corresponded to certain correlations between clinical, biochemical, EEG and EMG findings. The authors describe a classificational scheme of 4 stages of an apopletic coma. Special significance in the pathogenesis of a coma along with structural lesions in the different areas of the CNS is attached to metabolic disturbances and extracerebral factors (respiratory and circulatory disorders).     

Changes in the ultrastructure of interneuronal connections in experimental chronic morphine poisoning

Wound care professionals are often called upon to prepare others to care for patients with chronic and other forms of skin injury. Case presentations offer a creative and meaningful approach in teaching assessment and treatment options. However, case presentations pose threats to patient confidentiality and privacy. Using a clinical situation, confidentiality and privacy issues that can arise from these case presentations are briefly described and recommendations are provided to enable clinicians to avoid situations that violate the patient's privacy.