The Study on the Corrosion Behaviour of Welded and Unwelded Medium Carbon Steel in Sodium Chloride (Nacl) Solutions

The research work was based on the study of the corrosion behaviour of the welded and un-welded medium carbon steel in sodium chloride solutions. The Sodium chloride solutions used are 1ml, 2ml, 3ml and 4ml for both welded and un-welded medium carbon steel in NaCl. The experiments were conducted in two ways, the weight loss analyses of measurements and using the electrochemical analyzer workstation to determine the potential dynamic of the samples. The samples for the weight loss measurements were prepared from rolled products obtained at the foundry shop. Two medium carbon steel materials were sourced with different chemical compositions as sample A and B. The materials were prepared to accommodate the experiments for the determination of welded and un-welded medium carbon steel. A total of sixty-eight (68) samples were produced, prepared and used for the weight loss measurements /analyses the experiments. Thirty-four of the samples each were prepared for both the welded and un-welded experiments. All the samples were produced and prepared through the use of various machining processes with the use of a lathe machine for planning, milling. Thirty-four (34) of the sample preparation were further welded in readiness of the experiments. Sixty –eight breakers were sourced for and used. Ten (10) other samples were used for the determination with the use of the electrochemical analyzer. The chemical compositions of the medium carbon steel were determined with the use of SPECTRO Analytical Instruments. A metallurgical inverted optical microscope was used to determine the microstructures of the materials. The Scanning Electron Microscopy with EDS was used to determine the morphologies of the materials. The thirty-four of the samples were welded this process was performed to determine the effects of welding on the material surrounding the weldments. These materials were made into sizes with the use of power hacksaw (i.e. 2cm by 2cm). Other materials were prepared to 1cm x 1cm thickness from the same materials. The Tafel plot experiments and that of the open Circuit Potential Time (OCPT) were carried out with the use of Electrochemical Analyzer/ Workstation. The Medium carbon steel materials were exposed for fifty – four (54) days, with an interval of 3days. The corrosion rates analyses were determined and the graphs of the corrosion rates (mm/yr.) and other parameters were used plotted against No of days exposed.

Exhaled nitric oxide in smokers and former smokers with chronic obstructive pulmonary disease

Background: Measurement of fractional exhaled nitric oxide (FeNO) is a useful technique for detection of eosinophilic airway inflammation and assessment of efficiency of corticosteroid treatment in patents with respiratory disease. Generally studies agree that measurement of FeNO is a useful non-invasive biomarker in patients with chronic obstructive pulmonary disease (COPD), however, there are reports that do not confirm such a relationship between FeNO and COPD. Aim of the study: The main objective of this study was to investigate FeNO levels in Polish patients with COPD compared to healthy controls. As a secondary objective, we assessed the influence of smoking on FeNO levels in healthy patients, and patients with COPD. Material and methods: FeNO concentration was measured using an electrochemical analyzer in healthy non-smokers (n=21), healthy smokers (n=25), and former smokers with COPD (n=30) and smokers with COPD (n=38). General characteristics, hematological variables and serum biochemical parameters were also obtained and analyzed using the Kruskal-Wallis test. Results: FeNO measurement revealed significantly reduced NO levels in healthy smokers compared to healthy non-smokers, former smokers with COPD and smokers with COPD (median [range]: 14 [6–17] vs. 21 [15–29], 25 [15–53], and 19 [11–32] ppb, respectively, p<0.001). Moreover, we found increased FeNO levels in ex-smokers with COPD compared with smokers with COPD (p<0.05). No associations between FeNO and other analyzed parameters were found. Conclusions: Levels of FeNO, measured by with an electrochemical analyzer, were elevated among patients with COPD compared to healthy non-smoking controls. Moreover, our study confirms that smoking results in a reduction in FeNO concentration in both healthy patients and patients with COPD.

A rapid on-site analysis method for the simultaneous extraction and determination of Pb2+ and Cd2+ in cereals

To achieve rapid on-site screening rapid pretreatment for the determination of Pb2+ and Cd2+ in cereals by a portable electrochemical analyzer with disposable screen-printed electrodes, a new reliable and simple extraction method for Pb2+ and Cd2+ was developed.