Analytic formulas for acoustic interference patterns in shallow water are derived by ray method. Which can be used to guide acoustic measurements with limited horizontal distances. Some necessary approximations are ta...Analytic formulas for acoustic interference patterns in shallow water are derived by ray method. Which can be used to guide acoustic measurements with limited horizontal distances. Some necessary approximations are taken for a concise expression. The analytic for- mulas represent the quantitative relationships between the interference-pattern and the signal frequency, bandwidth, depth of source and horizontal distance. Monofrequent signals, com- plicated signals and frequency-modulated signals are all studied. Several inferences are also deduced from the formulas. Both numerical simulations and experiment data are presented to prove that these formulas and their inferences can describe the critical characters of the acoustic interference pattern in the waveguide with a satisfying precision.展开更多
Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the...Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval.展开更多
文摘Analytic formulas for acoustic interference patterns in shallow water are derived by ray method. Which can be used to guide acoustic measurements with limited horizontal distances. Some necessary approximations are taken for a concise expression. The analytic for- mulas represent the quantitative relationships between the interference-pattern and the signal frequency, bandwidth, depth of source and horizontal distance. Monofrequent signals, com- plicated signals and frequency-modulated signals are all studied. Several inferences are also deduced from the formulas. Both numerical simulations and experiment data are presented to prove that these formulas and their inferences can describe the critical characters of the acoustic interference pattern in the waveguide with a satisfying precision.
基金the Gazi University research fund for the financial support of this research.
文摘Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval.
