Study of the spatial redistribution of the analyte spectral emission in dc arc plasma induced by external oscillating magnetic field

Monochromatic digital imaging technique was developed for studying the spatial emission intensity distribution of atmospheric pressure dc arc plasma with aerosol supply. Arc plasma was imposed to external oscillating magnetic fields of strengths up to 12 mT and frequency of 50 Hz. This plasma was studied in a laterally resolved manner and at selected observation heights. The intensity enhancement and spatial redistribution of the analyte emission was evaluated and compared to the steady state plasma. The intensity enhancements were correlated with the attained speeds of plasma core movement. Spatial regions in the arc plasma with maximal emission enhancement are identified and clarified. The effect of the electrode polarity was also investigated.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Analytical capability of plasma induced by IR TEA CO2 laser pulses on copper target

Spatially-resolved time-integrated optical emission spectroscopy was applied for investigation of copper plasma produced by a nanosecond Infrared (IR) Transversely Excited Atmospheric (TEA) CO2 laser, operating at 10.6 µm. The maximum intensity of emission, with sharp and well resolved spectral lines, and negligibly low background emission, was obtained from a plasma zone 8 mm from the target surface. The favorable signal to background ratio obtained in this plasma region, indicate possible analytical application of TEA CO2 produced copper plasma. Detection limits of trace elements present in the Cu sample were in the order of 10 ppm

Prospective of the LDI MS to characterization the corrosion products of silver-copper alloys on an example of the Ag-Cu-X (X- Zn, Pd, In) system

This work presents the perspective of applying the laser desorption/ionization mass spectrometry (LDI MS) for characterization the anode film of the Ag60Cu26Zn14, Ag58.5Cu31.5Pd10, and Ag63Cu27In10 alloys (at high concentrations of chloride ions in solutions). The reference LDI mass spectra of anode films of pure Ag and Cu have been used for the identification of product corrosion. Knowing the clusters detected in the reference spectra lead to the facilitating identification of the LDI mass spectrum of the sample and reduces the analysis time. The LDI MS analysis of these alloys revealed that the predominant corrosion product are AgCl (from AgnCln+1−/+, n = 1–3), and CuCl (from “superhalogen” CumCln− clusters, m = 1–2, n = 2–6); it also revealed Cu2(OH)3Cl (from Cu2(OH)(H2O)2+) and Cu2O (from Cu(H2O)+, Cu2O doped with chlorine). These results are in accordance with the X-ray diffraction and Raman analysis. The LDI MS spectra of alloys contain the additional peaks formed due to the mutual influences of different metals in the alloys (AgCuCl3− (AgCl-CuCl2−), AgCu2Cl4− (AgCl-CuCl-CuCl2−), and Ag2CuCl4− (AgCl-AgCl-CuCl−), which is consistent with the identified corrosion products. It should be noted that the LDI MS suggest the presence of CuCl2, which can be interpreted as the corrosion products retained in the porous films of alloys, and not detected by the other methods due to a small amount. The future theoretical and experimental studies of metal clusters, significant for metallurgy, can contribute that the LDI MS is becoming a powerful analytical tool for characterization the metal surfaces

Why doctors and pharmacists make errors during internship?

Background: After completion of formal education, physicians and pharmacists have to be trained to become independent practitioners. During the internship they are mentored by experienced practitioners. The aim: To discover factors associated with prescribing and dispensing errors during internship. Materials and methods: This study was of qualitative design, using grounded theory method. Six physicians and six pharmacists were interviewed during their internship. The interviews were recorded, transcribed, filtered and divided to semantic units which were than grouped into categories and themes. Results: The most important factors associated with prescribing or dispensing errors made by physicians and pharmacists during their internship were: insufficient knowledge, large workload, insufficient staffing, illegible hand-writing, unwillingness of mentors in hospitals to teach interns and exhaustion during working hours. Conclusions: This study revealed the most important factors associated with prescribing and dispensing errors during internship. Adequate corrective measures could eliminate majority of listed factors and significantly decrease frequency of errors, increasing safety of the patients in the same time

Determination of total lipids and characterization of marigold flower extracts (Calendula officinalis)

Bioactive extracts from marigold flower are important ingredients for parapharmaceutical and cosmetic preparations. Their antiflogistic holeretic.antimicrobic, antidermatic and anticancer effects are due to the presence of flavonoids, carotenoids, etheric oils, and terpenoids. This study presents the results of spectrophotometric investigation for the overall carotene content calculated as (3-caroten (442 nm), visual and physico-chemical characteristics according to Ph.Jug. V in oil extracts of marigold flower obtained by maceration (room temperature and 70°C) and percolation (room temperature) with olive oil and sunflower oil by original procedures.The largest content of (3-carotene (57.5 mg/kg of oil extracts) is in the oil extract obtained by maceration for 72 hours with olive oil (solvomodulus 1:5 m/m) at room temperature

Anticancer effect of novel luteolin capped gold nanoparticles selectively cytotoxic towards human cervical adenocarcinoma HeLa cells: An in vitro approach

Background: Although luteolin has been confirmed as potent anticancer agent, its potential application as therapeutic is limited by its water solubility. To overcome this shortcoming nanoparticle technology approach was applied. Owing to their proven low toxicity and the possibility to be easily functionalized gold nanoparticles (AuNP) were the nanosystem of choice used in this study. Novel luteolin capped gold nanoparticles (AuNPL) were synthesized and their anticancer effect towards human cervical adenocarcinoma HeLa cells was investigated in vitro. Methods: AuNPL were synthesized by reducing chloroauric acid by trisodium citrate with subsequent addition of luteoline during synthesis and their physicochemical characterization was done. AuNPL cytotoxicity against HeLa, human malignant melanoma A375, and normal human keratinocytes HaCaT cells was tested by MTT cell survival assay, and their IC50 values were determined. The capability of AuNPL to induce cell cycle arrest and apoptosis in HeLa cells were demonstrated by flow cytometry. The antioxidant activity of AuNPL was assessed by DPPH⋅ and ABTS⋅þ scavenging assays. Cytoprotective properties of AuNPL towards HaCaT cells were examined by measuring the physiological and H2O2 induced intracellular reactive oxygen species (ROS) levels using flow cytometry. Also, genotoxicity of AuNPL in HaCaT cells was investigated by the single cell alkaline comet assay. Results: Spherical AuNPL, stable in aqueous solution up to six months at 4 ◦C were obtained in the synthesis. The selectivity in the cytotoxic action of AuNPL on HeLa and A375 cancer cells compared with their cytotoxicity on normal keratinocytes HaCaT was observed. AuNPL exerted their cytotoxic activity against HeLa cells through accumulation of the cells in the subG1 phase of the cell cycle, inducing the apoptotic cell death mediated by the activation of caspase-3 − 8, and − 9. AuNPL antioxidative potential was confirmed by DPPH⋅ and ABTS⋅þ scavenging assays. IC50 concentration of AuNPL exerted cytoprotective effect against HaCaT cells by the significant reduction of the physiological intracellular ROS level. Additionally, AuNPL were shown as more cytoprotective towards HaCaT cells then luteolin due to the more successful elimination of H2O2 induced intracellular ROS. Moreover, nontoxic concentrations of AuNPL did not cause considerable DNA damage of HaCaT cells, indicating low genotoxicity of the nanoparticles

Room-temperature ferromagnetism in Ni2+ doped TiO2 nanocrystals synthesized from nanotubular precursors

Hydrothermal synthetic route for synthesis of Ni2+ doped TiO2 nanocrystals showing room temperature ferromagnetism, using dispersion of titania nanotubes in the presence of Ni2+ ions at different pHs as precursors, is reported. Morphologies of tubular precursors and Ni2+ doped TiO2 nanocrystals were characterized by transmission electron microscopy. Titania nanotubes have outer diameter of about 10 nm while the length varies widely even reaching few hundred nanometers. Ni2+ doped TiO2 nanoparticles synthesized at pH 3 have polygonal shape and dimension of about 20 nm. Transmission electron microscopy analysis revealed presence of mixed shapes (polygonal and rod like) in the sample of Ni2+ doped TiO2 nanoparticles synthesized at pH 5. X-ray diffraction analysis of resultant powder and selected area electron diffraction pattern confirmed the anatase crystal phase of Ni2+ doped TiO2 nanoparticles independently of dopant concentrations (0.09, 0.25, 0.86, 1.48 and 1.80 at%), followed by slight changes of their microstructural parameters. Reflection spectra of Ni2+ doped TiO2 nanoparticles revealed their altered optical properties in comparison to undoped TiO2 nanoparticles. Room temperature ferromagnetic ordering with saturation magnetic moment in the range of 10(-3)-5 x 10(-2) mu B per Ni atom was observed for all measured films made of Ni2+ doped TiO2 nanoparticles. (C) 2013 Elsevier B. V. All rights reserved

Hydrothermal synthesis of Mn2+ doped titanate nanotubes: Investigation of their structure and room temperature ferromagnetic behavior

Hydrothermal synthesis of Mn2+ doped titanate nanotubes (TNTs), which exhibited room temperature ferromagnetism (RTFM), is reported. Dispersions of 1 and 5 at.% Mn2+ doped anatase TiO2 nanocrystals were used as precursors. Size and shape of Mn2+ doped TNTs and precursor nanocrystals were studied by transmission electron microscopy (TEM). The relatively uniform size distribution of transverse dimension of nanotubes of about 10 nm was observed while their lengths varied up to few hundred nanometers. The X-Ray Diffraction (XRD) analysis and Raman spectroscopy of resultant powder confirmed the hydrogen dititanate (H2Ti2O5 x H2O) crystal phase of Mn2+ doped TNTs with the presence of small amount of sodium titanates. Electron paramagnetic resonance (EPR) experiments were performed to probe the local atomic and electronic structure of Mn in the nanotubes. Room temperature ferromagnetic ordering with saturation magnetic moment (M-s) in the range of 0.6-1.5 mu(B) per Mn atom was observed

The influence of migration processes in gunpowder charge on the quality of mortar ammunition

The study describes the results of static, physicochemical and ballistic examination of double-based gunpowder charges, in order to establish the deviations from the demanded quality of mortar ammunition. The examinations were carried out on gunpowder samples used for laboration of mortar shells 60, 82 and 120 mm caliber and consisted of periodical measurements of the gunpowder mass loss, basic ballistic parameters, and compatibility testing of gunpowder and celluloid containers as well as chemical stability determination. The estimation of the gunpowder quality was performed by comparative analysis and the suggestions for more efficient production of it were given

Shaped Co2+ doped TiO2 nanocrystals synthesized from nanotubular precursor: Structure and ferromagnetic behavior

Co2+ doped TiO2 nanocrystals were synthetized by a hydrothermal treatment procedure applied to precursor dispersion of titania nanotubes and Co2+ ions. Mixture of polygonal and prolate spheroid-like nanocrystals was obtained. The results of X-ray diffraction (XRD) analysis showed that resulted nanocrystals retain anatase crystal phase for both dopant concentrations (1.69 and 2.5 at%), but the crystal lattice parameters were affected. Reflection spectra revealed altered optical properties compared to bare TiO2. Room temperature ferromagnetic ordering with saturation magnetic moment in the range of 0.001-0.002 mu (B)/Co was observed for both measured films made of Co2+ doped TiO2 nanocrystals