Search Results

You are looking at 1 - 2 of 2 items for

  • Author: Michał Łach x
Clear All Modify Search
Open access

Krzysztof Buśko, Zbigniew Staniak, Patrycja Łach, Joanna Mazur-Różycka, Michalski Radosław and Michał Górski

Summary

Study aim: the aim of the study was to compare two methods for measuring punching and kicking force and the reaction time of athletes.

Material and methods: both systems were designed to measure and to analyse the mechanical characteristics of punches and strikes delivered by upper and lower limbs to a punching bag. The main difference between both punching bags was the way in which the delivered force was measured. The first method used strain gauges while the second method used accelerometer technology. Both systems consisted of a punching bag with software, attached signal diodes, and either embedded accelerometers or strain gauges. The bags were of different sizes. Acceleration transducers and gyroscopes or strain gauges were placed inside the punching bags, which allowed for measuring dynamics while the bag was struck. The software calculated strike force, the point of force application and its direction, and reaction time. Both systems were tested.

Results: the results of the accelerometer-based method show that the mean relative error of force calculation amounts to 3%. The measurement error of acceleration is less than 1%. The mean relative measurement error of the striking surface on the punching bag is 2%. However, the measurement error of force recorded with the strain gauge-based method is less than 1%. The results show that both systems are similar.

Conclusions: the punching bag having an embedded accelerometer is equipped with more versatile software, which makes the system a good tool for practical application in combat sport training.

Open access

Agnieszka Grela, Michał Łach, Tomasz Bajda and Janusz Mikuła

Abstract

In Poland, by 2020 430,000 Mg of hazardous waste will be formed annually by the combustion of waste. This waste must be properly managed so as not to endanger the environment. One promising way to manage selected waste is to process it in the synthesis of materials characterised by sorption properties. The results presented in this paper concern the possibility of producing sorbents from waste materials marked with codes 190112 and 190114, which came from two waste incineration plants in Poland. Alkaline activation was performed using two methods: a) hydrothermal, in a solution of 8 M NaOH at 75°C for 24 h; and b) in an autoclave, using a solution of 2 M NaOH at 140°C for 6 h. XRD analyses led to the identification of materials after synthesis of the following zeolite phases: analcime, chabazite and thomsonite. chabazite and analcime can be valuable absorbent materials.