Jan Mucko

Bio: Jan Mucko is an academic researcher from Life Sciences Institute. The author has contributed to research in topics: Inverter & Resonant inverter. The author has an hindex of 4, co-authored 15 publications receiving 47 citations.

Errors in the analysis of series resonant inverter/converter assuming sinusoidal waveforms of voltage and current

Abstract: In this paper the theory and simulation results of the series resonant inverter / converter are presented. In this work the authors carried out a detailed comparative analysis of results obtained using the method of AC analysis in the steady state for the first harmonic with the results of computer simulation. The AC analysis under certain conditions can lead to errors disqualifying this method. In particular, these errors appear by low quality factor of resonant circuit, pulsed, discontinuous load current, switching frequency significantly different from the resonance. It was also shown that the coefficient for transforming the resistor behind the rectifier into the equivalent resistor in AC circuit may vary substantially from the values known from the literature.

Using Chou’s 5-Step Rule to Evaluate the Stability of Tautomers: Susceptibility of 2-[(Phenylimino)-methyl]-cyclohexane-1,3-diones to Tautomerization Based on the Calculated Gibbs Free Energies

Abstract: Gibbs free energies, based on DFT (Density Functional Theory) calculations, prove that enaminone (2-(anilinemethylidene)cyclohexane-1,3-dione) and ketamine (2-[(phenylimino)-methyl]cyclohexane-1,3-dione) are the most and least stable tautomeric forms of the studied systems, respectively. 1H and 13C NMR spectra prove that 2-(anilinemethylidene)cyclohexane-1,3-diones are the only tautomeric species present in dimethylsulfoxide solution (a very weak signal can be seen only for the p-methoxy derivatives). The zwitterionic character of these enaminones is strengthened by naphthoannulation and by the insertion of the electron-withdrawing substituent into the benzene ring (the latter weakens the intramolecular hydrogen bond in the compound). Substituent and naphtoannulation have no effect on the stability of the studied tautomers. Slight twisting of the benzene ring, with respect to the CArNC plane (seen in the crystalline state), was proven to also take place in vacuum and in solution.

A new panel-integratable inverter concept for grid-connected photovoltaic systems

Abstract: This paper describes the problems of conventional inverter concepts for photovoltaic power systems and presents a new, panel-integratable inverter concept as a solution. This concept is advantageous regarding safety (no DC-lines), flexibility (modular concept), converted energy per year (no mismatch losses due to individual MPP tracking of each panel) and costs (no reinforced isolation due to AC distribution). Furthermore a 250 W DC to AC inverter is developed, which consists of a series resonant DC-DC power converter and a line inverter. The inverter has a high efficiency and consumes little power itself. Meeting international standards, sinusoidal line current with low distortion is achieved. The inverter has a built-in controller to operate the panel in the maximum power point. Above this, the concept allows the flexible use with many different combinations of solar panels. To realize an inexpensive system, the controller is built up using standard low-cost components.

Analysis and Design of a Wireless Charger for Underwater Vehicles Fed from a Constant Current Distribution Cable

Abstract: Existing conductive power supplies for undersea electronic systems are typically fed from constant low-current distribution with a seawater return In such systems, power converters are connected in series along the distribution cable to supply power to sensor loads and underwater vehicles Isolated voltage fed resonant converters are often used for the advantages of soft-switching and low component stress When supplying underwater vehicles, there is further motivation to develop a wireless solution to improve reliability by removing the seawater exposed contacts This can be accomplished by replacing the isolation transformer of existing resonant converters with series-series compensated coupled coils to create an inductive power transfer (IPT) solution The introduction of the IPT system changes many factors in the design that need to be considered This paper presents detailed analysis and design of wireless charger for underwater vehicles fed from a constant current distribution cable The design is validated with experimental results for a 330 W prototype supplied from a 1 A source operated underwater with a switching frequency of 250 kHz

Suppression of Undesired Attractors in a Self-Oscillating H-Bridge Parallel Resonant Converters Under Zero Current Switching Control

Abstract: Resonant converters under zero current switching control strategy can exhibit coexistence of attractors, making it difficult the startup of the system from zero initial conditions. In this brief, the problem of multiple coexisting attractors in parallel resonant converters is addressed. Appropriate modifications of the switching decision with the aim of converting undesired attractors into virtual ones are proposed. A suitable control signal is generated from the state variables of the system and used to adjust the switching decision. Numerical simulations corroborate the proposed solutions and the simplest one was finally verified by measurements from a laboratory prototype.

Direct treatment of pepper (Capsicum annuum L.) and melon (Cucumis melo) seeds by amplitude-modulated dielectric barrier discharge in air

Abstract: This study evaluates low-temperature plasma generated by an amplitude-modulated dielectric barrier discharge (DBD) as a direct surface treatment of pepper and melon plant seeds. An analysis of the discharge and its products revealed the influence of the seeds inserted into the plasma on the total plasma power and concentration of O3 and NOx, which are the dominant reactive oxygen and nitrogen species produced by the plasma. The plasma treatment of the seeds led to higher viability and higher imbibition rate during the first hour of exposure to the wet environment. X-ray photoelectron spectroscopy (XPS) analysis confirmed changes in the O:C ratio for plasma-treated pepper and melon seeds. However, prolonged plasma treatment for 300 s affected pepper and melon seeds differently. While the O:C ratio gradually increased with plasma treatment time for pepper seeds, that for melon seeds decreased considerably for longer treatment times. Furthermore, detailed XPS analysis of pepper seeds revealed a profound increase in magnesium and calcium, which are often present in seed macronutrients, and a minor increase in potassium, silicon, sulfur, and phosphorus, which are present in micronutrients. These observations can be related to the possible redistribution of the elements owing to the plasma treatment, and thus the treatment might have an essential influence on the seed bulk. The findings presented in this study help elucidate the plasma interaction with surfaces of pepper and melon seeds and confirm the feasibility of the direct plasma treatment using power-modulated DBDs for applications in agriculture.

Molecular mechanism of amyloidogenicity and neurotoxicity of a pro-aggregated tau mutant in the presence of histidine tautomerism via replica-exchange simulation

Abstract: The accumulation of ΔK280 tau mutant resulting in neurotoxic oligomeric aggregates is an important but yet mysterious procedure in Alzheimer's disease (AD) development. Recently, we proposed a histidine tautomerization hypothesis of tau fibrillogenesis for the pathobiology of AD and other neuro diseases. However, the influence of neutral histidine tautomeric states on tau mutation is still unclear. Herein, we performed replica-exchange molecular dynamics (REMD) simulations to characterize structural features as well as the mode of toxic action of the ΔK280 tau mutant in the presence of histidine tautomerism. Molecular dynamics (MD) simulation results show that the δe tautomeric isomer (having a distinct global energy minimum) had the highest β-sheet structure, which adopts a sheet-rich conformer and may have significant influence on the structural behaviors of ΔK280 tau monomers. Furthermore, clustering, residual contact map, mobility and structural analysis exhibited that the presence of β-strand interactions between stable lysine 8 (K8)-asparagine 13 (N13) and valine 39 (V39)-tyrosine 43 (Y43) residues plus K31-histidine 32 (H32) and K8-N13 (strand-loop-strand [β-meander] structure) helped δe to form toxic aggregates. Moreover, H299 played a more critical role in the conformational instability of the δe than H268. Overall, the results obtained from this study may be used to arrest neurodegeneration in ΔK280 tau mutation carriers as well as increase the understanding of AD-related tau pathogenesis and strengthen the histidine tautomerism hypothesis of misfolded peptide accumulation.