A large quantity of steel balls automatic precise counting device based on dual sensor auto-correcting method

A large quantity of Steel Balls Automatic precise Counting device is introduced in this paper. Inductance sensors are used for ball detection and STC15F2K60S2 microprocessor is used to do the signal processing. When steel balls are sent to the PVC pipe at the same time, some balls will connect together because of the collision. The sensor will send a connected signal instead of multiple signals if it meets the connected balls. This could cause counting mistake of the device. A correction method is used to solve this problem. The device setup angle could be gotten by using dual sensors to get the average moving speed of the steel balls according to the fixed relations between the setup angle and the speed, which is not affected by whether the steel balls overlap or not because it used two voltage Jump edge to judge the start and end moment of timer. After that, the device setup angle is used to get the standard moving time to single sensor according to the known function relationship. The counting numbers are corrected by using the standard duration to compare with each recording low voltage duration passing single sensor. This method solves the counting mistake problem when a lot of steel balls are pushed into the PVC pipe together. The device improves the efficiency and accuracy of the ball counting.

Experimental Evaluation of an Interferometric Light Microscopy Particle Counter for Titering and Characterization of Virus Preparations

Virus particle concentration is a critical piece of information for virology, viral vaccines and gene therapy research. We tested a novel nanoparticle counting device, “Videodrop”, for its efficacy in titering and characterization of virus particles. The Videodrop nanoparticle counter is based on interferometric light microscopy (ILM). The method allows the detection of particles under the diffraction limit capabilities of conventional light microscopy. We analyzed lenti-, adeno-, and baculovirus samples in different concentrations and compared the readings against traditional titering and characterization methods. The tested Videodrop particle counter is especially useful when measuring high-concentration purified virus preparations. Certain non-purified sample types or small viruses may be impossible to characterize or may require the use of standard curve or background subtraction methods, which increases the duration of the analysis. Together, our testing shows that Videodrop is a reasonable option for virus particle counting in situations where a moderate number of samples need to be analyzed quickly.

Does the use of step counting devices affect the level of physical activity and body mass index of the youth studying in Lublin during COVID-19 pandemic?

Introduction. Due to coronavirus disease 2019 (COVID-19) many people give up exercises. International physical activity guidelines recommend 150 minutes per week of moderate- to vigorous-intensity physical activity or 75 minutes at high intensity per week. Healthy adults should take 10,000 steps per day. Wearable devices (smartwatches, step counters, physical activity monitoring applications) have the potential to promote a healthy lifestyle at the time of COVID-19 pandemic. They are accepted by the youth. Aim. The aim of the study was to find out if using step counting devices affects the level of physical activity and body mass index (BMI) in students. Material and methods. A total of 303 participants (227 women, 76 men) studying in Lublin, Poland of mean age 19.5 years participated in the study conducted with use of an internet questionnaire. Results. Before the COVID-19 pandemic their mean BMI was 22.17 kg/m2 and after 9 months of COVID-19–related restrictions it was 22.57 kg/m2. Among the respondents 204 (67.3%) did a physical activity for 50 min 3 times a week in 2019 and 99 (32.7%) did not. In December 2020 there was a significant decrease in the number of students doing physical activity to 128 (42.2%) (p<0.05) and an increase in the number of students who did not do any physical activity to 175 (57.8%) (p<0.05). In 2019 as many as 110 (36.3%) of the respondents used to use step counting devices and 192 (63.7%) did not. In 2020 the number of students using activity tracking devices significantly decreased to 58 (19.2) (p<0.05). The number of students who did not use any step counting device in 2020 was 245 (80.8%). Conclusion. Due to the COVID-19 pandemic the number of students who don’t do enough physical activity significantly increased. The use of step counting devices helps students in continuing physical activity despite COVID-19-related restrictions.

EUV observation for Earth’s plasmasphere from EML2 by nano-spacecraft

&lt;p&gt;The nano-spacecraft (6U) mission named EQUULEUS will be launched in 2020 as one of the sub-payloads of NASA&amp;#8217;s Space Launch System. EQUULEUS will fly to a liberation orbit around the Earth-Moon L2 point and demonstrate trajectory control techniques within the Sun-Earth-Moon region for the first time as a nano-spacecraft. A small telescope for extreme ultraviolet (EUV) named PHOENIX will be boarded on the spacecraft. It consists of multilayer-coated mirror (diameter of 6 cm with Mo/Si coating), metallic thin filter, and photon counting device with microchannel plate and resistive anode. The reflectance of the mirror and transmittance of the filter are optimized for the emission line of ionic helium (wavelength of 30.4 nm) which is the important component of the plasmasphere of the Earth. By flying far from the Earth, the entire image of plasmasphere can be obtained. In this presentation, the mission concept and the design of the telescope, and the status of the latest development will be shown.&lt;/p&gt;