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Background. Success in sprinting events broadly depends on many factors. Among them, the reaction time at starting is one of the main factors that help sprinters get success by increasing their confidence and helping to avoid false starts. Study purpose. The purpose of the study was to find out the relationship between reaction time and performance time among women finalist sprinters in six Olympic Games since 2000. Materials and methods. Data were collected from 227 (n = 227) women finalist sprinters in the event of 100m (n= 47), 200m (46), 400m (43), 100m H (45), and 400m H (46) in 6 Olympic Games from 2000 to 2020, based on published official reports on worldathletics.org and olympedia.org websites. Data were considered from 227 samples from a total of 240 finalist women, where 13 were excluded because of a false start, being disqualified for doping, or failing to finish. Descriptive statistics, the Pearson correlation coefficient and simple regression analysis were used to determine the relationship between reaction time and performance time of the finalist women sprinters. The significance level was set at 0.05. Further Gaval’a 5-point scale was used to categorize the women sprinters based on their reaction times in five sprint events. Results. The results showed that there was a low positive correlation between reaction time and performance time among the sprinters in the 100m (r = 0.369, p

This paper reports the changes in the electrochemical behavior of Cu60Zr25Ti15 bulk metallic glass (BMG) with the addition of 1 at.% Mo and Nb in 3.5 wt.% NaCl aqueous solution. Electrochemical methods employed for the study are open-circuit potential (OCP) and potentiodynamic polarization. The OCP values of the parent BMG and minor-alloyed BMGs differ only marginally. However, potentiodynamic studies show slightly higher corrosion resistance for the minor-alloyed BMGs than that of the parent alloy. Polarized surfaces of all the samples, examined under a scanning electron microscope (SEM), reveal pits formed due to corrosion. Corrosion products are analyzed by energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Higher corrosion resistance observed for Nb- or Mo-added BMGs is attributed to the formation of NbO2/Nb2O5 and MoO2, respectively, besides the oxides of other constituent elements. [ABSTRACT FROM AUTHOR]

Typical high power consumption (∼10 W) of mid-infrared quantum cascade lasers (QCLs) has been a serious limitation for applications in battery powered systems. A partial high-reflection (PHR) coating technique is introduced for power downscaling with shorter cavity lengths. The PHR coating consists of a double layer dielectric of SiO2 and Ge. With this technique, a 4.6 μm QCL with an ultra low threshold power consumption of less than a watt (0.83 W) is demonstrated in room temperature continuous wave operation. At 25°C, the maximum output power and wall plug efficiency are 192 mW and 8.6%, respectively. [ABSTRACT FROM AUTHOR]

Byline: N . Bandyopadhyay We have investigated various techniques for joining large sections of graphite which will be useful for the construction of graphite mandrels (tools) for the manufacture of fibre-reinforced composites. The effects of brazing alloy, brazing environment, joint design and metallized coating thickness on brazed joint integrity were studied. Graphite sections can be brazed directly using a titanium containing Ag-Cu-Ni brazing alloy under an argon or a hydrogen-containing furnace atmosphere, rather than under vacuum as previously practiced. The brazed joint showed excellent strength at room temperature as well as at elevated temverature. Graohite test oieces metallized with electroless nickel (coating thickness of 0.632 inches) and then subskquently brazed with conventional brazing alloy under inert or slightly reducing atmosphere also showed excellent joint integrity at room temperature as well as at elevated temperature