Muscle skin temperature responses for hamstring and quadriceps to aerobic and anaerobic test conditions in Turkish Olympic Sailing Athletes

Olympic class sailing is a competitive sport and requires several abilities. An understanding of the responses to aerobic and anaerobic loading will be useful for assessing the training programs, protective strategies and possibility of injuries. Therefore, the aim of this study is to determine lower extremity main muscles skin temperature responses to aerobic and anaerobic test conditions in Turkish Olympic Sailing Athletes. Eighteen sailing athletes were assessed during preseasonal assessment period. Temperatures of quadriceps and hamstring muscle groups were evaluated bilaterally during rest and after Wingate Treadmill tests. Wingate test was accepted as an indicator of anaerobic performance and Treadmill test as an aerobic performance. Infrared thermography was performed to assess the skin temperature at anterior and posterior parts of thigh for both legs. In the triplicate comparison, the temperature changes between the rest, aerobic test and anaerobic test conditions were significant (p?<?0.05). In the analysis to determine the difference between the compared groups; for both muscle groups, temperature change after anaerobic performance was not significant; in contrast to this result the change in muscle temperature after aerobic performance was significant (p?<?0.05). Energetic—metabolic activity of major muscle groups of lower extremities during aerobic and anaerobic performance are important for injury prevention, treatment, rehabilitation and return to play. Present study shows that aerobic performance or activities requires higher energetic-metabolic activity.

     

Determination of trace impurities in some nickel compounds by flame atomic absorption spectrometry after solid phase extraction using Amberlite XAD-16 resin

A simple flame atomic absorption spectrometric (FAAS) procedure for the determination of lead, bismuth, gold, palladium and cadmium as impurities in Raney nickel and nickel oxide was developed using a preconcentration step on an Amberlite XAD-16 resin packed column. Lead, bismuth, gold, palladium and cadmium were quantitatively recovered and separated from a solution containing 1 M HCl and 0.3 M NaI by the column system. Effects of the various parameters such as reagent concentrations, sample volume, matrix effects, etc. have been investigated. Under optimized conditions, the relative standard deviation of the combined method of sample treatment, preconcentration and determination with FAAS (n = 7) is generally lower than 12%. The limit of detection (3s, n = 20) was between 10–270 ng/g. The results were used for separation and preconcentration of five trace elements from nickel matrices.     

Selective and sensitive determination of dopamine via suppressing ascorbic acid using an N-(1-H-indole-3yl) methylene thiazole-2-amine thin film-modified glassy carbon electrode

The selective determination of dopamine (DA) was performed using a glassy carbon (GC) electrode modified with N-(1-H-indole-3yl) methylene thiazole-2-amine (IMT2A). IMT2A was deposited on the GC electrode by cyclic voltammetry. This modified electrode demonstrated an electrocatalytic effect on the oxidation of DA in the presence of uric acid (UA) and ascorbic acid (AA) using differential pulse voltammetry (DPV) method in 0.1 M phosphate buffer solution (PBS) of pH 7. Selective determination was realized in elimination of AA response on the IMT2A-modified electrode. The oxidation peak currents increased linearly with two concentration intervals of DA at pH 7 phosphate buffer. One of them is 0.25–9.15 μM, and the other is 9.15–95.1 μM. The limit of detection (LOD) was found as 0.086 μM. The proposed electrode was applied to the determination of DA in pharmaceutical preparations and human urine sample with satisfactory results.

     

Graybody radiation phenomena in a fractional manner

In this paper, the graybody radiation phenomena has been handled with the help of fractional calculus. Fractional definition of graybody spectrum has been written in terms of Mittag‐Leffler function. The obtained data from fractional calculus approximation for nearly 2.87 × 10⁷ K have been compared with literature values and standard blackbody radiation.     

Pressure-dependent mechanical and thermodynamic properties of newly discovered cubic Na2He

Recently for the first time, a stable compound of He and Na (Na₂He) is predicted at high pressure. We explore the pressure-dependent elastic, mechanical and thermodynamic properties of this newly discovered Na₂He by using ab initio technique. The calculation presents good accordance between the theoretical and experimental lattice parameters. Though the most stable structure of Na₂He is found at 300?GPa, present study ensures the mechanical stability of this compound up to 500?GPa. The study of Cauchy pressure, Pugh's ratio, and Poisson's ratio implies the ductile manner of Na₂He up to 500?GPa. According to the value of Poisson's ratio the bonding force exists in Na₂He is central. The study of Zener anisotropy factor indicates that Na₂He is an anisotropic material but near at 300?GPa approximately isotropic nature of Na₂He is revealed. The study of the bulk modulus, shear modulus, Young's modulus and Vickers hardness implies that the hardness of Na₂He can be improved by applying external pressure. However, the Debye temperature, melting temperature and minimum thermal conductivity of Na₂He are also calculated and discussed at different pressures.