Calibration methods of new device for human blood pressure measurement

The paper presents two methods of determining calibration curve of a new device for blood pressure measurement. The device was developed at Wrocław University of Science and Technology. First method is based on parallel measurement of systolic and diastolic pressure measurement with use of reference device such as sphygmomanometer and researched new device with pneumatic sensor equipped with voltage type output. Obtained data (systolic ps and diastolic pd pressure, maximum us and minimum ud voltage) was then used to determine individual pressure-voltage characteristic of the device, which can be represented as a linear equation. Second method is based on substitution of experimentally proved coefficient b with its analytical equivalent extracted from mathematical model of described pneumatic sensor. Described methods were verified experimentally and compared. Metrological parameters of the device were designated

Calibration methods of new device for human blood pressure measurement

The paper presents two methods of determining calibration curve of a new device for blood pressure measurement. The device was developed at Wrocław University of Science and Technology. First method is based on parallel measurement of systolic and diastolic pressure measurement with use of reference device such as sphygmomanometer and researched new device with pneumatic sensor equipped with voltage type output. Obtained data (systolic ps and diastolic pd pressure, maximum us and minimum ud voltage) was then used to determine individual pressure-voltage characteristic of the device, which can be represented as a linear equation. Second method is based on substitution of experimentally proved coefficient b with its analytical equivalent extracted from mathematical model of described pneumatic sensor. Described methods were verified experimentally and compared. Metrological parameters of the device were designated

Comparison of Cr(VI) Adsorption Using Synthetic Schwertmannite Obtained by Fe3+ Hydrolysis and Fe2+ Oxidation: Kinetics, Isotherms and Adsorption Mechanism

Good sorption properties and simple synthesis route make schwertmannite an increasingly popular adsorbent. In this work, the adsorption properties of synthetic schwertmannite towards Cr(VI) were investigated. This study aimed to compare the properties and sorption performance of adsorbents obtained by two methods: Fe3+ hydrolysis (SCHA) and Fe2+ oxidation (SCHB). To characterise the sorbents before and after Cr(VI) adsorption, specific surface area, particle size distribution, density, and zeta potential were determined. Additionally, optical micrographs, SEM, and FTIR analyses were performed. Adsorption experiments were performed in varying process conditions: pH, adsorbent dosage, contact time, and initial concentration. Adsorption isotherms were fitted by Freundlich, Langmuir, and Temkin models. Pseudo-first-order, pseudo-second-order, intraparticle diffusion, and liquid film diffusion models were used to fit the kinetics data. Linear regression was used to estimate the parameters of isotherm and kinetic models. The maximum adsorption capacity resulting from the fitted Langmuir isotherm is 42.97 and 17.54 mg·g−1 for SCHA and SCHB. Results show that the adsorption kinetics follows the pseudo-second-order kinetic model. Both iron-based adsorbents are suitable for removing Cr(VI) ions from aqueous solutions. Characterisation of the adsorbents after adsorption suggests that Cr(VI) adsorption can be mainly attributed to ion exchange with SO42− groups

A photovoltaic source I/U model suitable for hardware in the loop application

This paper presents a novel, low-complexity method of simulating PV source characteristics suitable for real-time modeling and hardware implementation. The application of the suitable model of the PV source as well as the model of all the PV system components in a real-time hardware gives a safe, fast and low cost method of testing PV systems. The paper demonstrates the concept of the PV array model and the hardware implementation in FPGAs of the system which combines two PV arrays. The obtained results confirm that the proposed model is of low complexity and can be suitable for hardware in the loop (HIL) tests of the complex PV system control, with various arrays operating under different conditions

Use of synthetic zeolite materials from fly ash to remove copper(II) ions from aqueous solutions

Water quality and waste management are two chief problems that the modern world is struggling with. Intensified development of the industry not only leads to the production of large amounts of solid waste that must be stored in landfills but can also result in contaminant emissions into the environment. Enormous quantities of ash produced from coal combustion have been a long-term problem of the industry. Literature studies show that fly ash can be used as a material to produce cheap and efficient zeolite-type adsorbents due to abundance of alumina-silicates in their composition. Fly ashes which were processed into zeolites as a result of alkaline hydrothermal treatment were obtained from two power plants in Poland (in Turów and Zgierz). The obtained zeolite materials and raw fly ash samples were characterised in terms of specific surface area, particle size distribution and density. The structure was also investigated using Fourier transform infrared spectroscopy (FTIR) in the mid- infrared wavenumber range. Two raw fly ashes and two zeolite materials were examined for their ability to remove Cu(II) ions from aqueous solutions. The results showed that the amount of adsorbed copper ions by alkaline-modified fly ash was higher than for unmodified fly ash. The ion removal efficiency is high and exceeds 95%