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Number of results: 8
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Abstract

The paper presents the use of visual evoked potentials VEP to the objective assessment of visual acuity. Methods of using visual evoked potentials (VEP) rely on the assessment of changes of the electrical action potentials generated within the cortex. To diagnose the degree of weakening eyesight a series of studies on healthy people and visually impaired ones were made. Electrophysiological studies of the eye, using noninvasive VEP examination allow a noninvasive and objective assessment of visual acuity. The use of visual evoked potentials gives the objectivity in assessment of visual acuity what may be very important in ophthalmology. This particularly may concern children examination, people with mental retardation and suspected of simulation.

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Authors and Affiliations

Arkadiusz Hulewicz
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Abstract

The article presents the investigations of 7xxx aluminium alloys performed by the method of thermal and derivational analysis. The studies made it possible to identify the effect of the changes in the Cu concentration, the total Zn and Mg weight concentrations and the Zn/Mg weight concentration ratio on their crystallization process: the cooling as well as the kinetics and dynamics of the thermal process of cooling and crystallization. Metallographic studies were performed on the microstructure of the examined alloys and their HB hardness was measured. The evaluation of the changes was presented in reference to the model alloys EN AW-7003 and EN AW-7010, whose microstructure under the conditions of thermodynamic equilibrium are described by the phase diagrams: Al-Zn-Mg and Al-Zn-Mg-Cu. The performed investigations confirmed that the hardness HB of the examined alloys is mainly determined by the reinforcement of the matrix αAl by the introduced alloy additions and the presence of phases Θ(Al2Cu) and S(Al2CuMg) rich in copper, as well as η(MgZn2), in the examined alloys' microstructure. The increase of the amount of intermetallic phases precipitated in the microstructure of the examined alloys is caused, beside Cu, by the characteristic change of Zn wt. concentration and Mg. It was proposed that the process of one-stage thermal treatment of the examined alloys be introduced at a temperature of up to tJ-20 °C, which will prevent the exceedance of the solidus temperature.

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Authors and Affiliations

B.P. Pisarek
E. Czekaj
T. Pacyniak
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Abstract

In modern microelectronics progress has been made towards low power ultra large-scale integration (ULSI), and nano-structure devices such as single electron transistors and quantum dots. In this technology application of new materials, which includes high-κ dielectrics for the MOSFET transistors, with extraordinary purity and uniformity is required. Failure analysis and reliability investigations of such films very often requires highresolution local measurements of electrical surface parameters. This kind of experiments can be performed using conductive atomic force microscopy, which provides simultaneous measurement of surface topography and current ?owing through the investigated layer. In order to acquire reliable data, there was designed a precise measurement and control system, which included a low-noise current-to-voltage converter of picoampere resolution, a scanning stage with control electronics and a data acquisition system. In the paper we describe the architecture of the designed and applied experimental set-up. We also present results of simultaneous measurements of topography and current on gold and highly oriented pyrolytic graphite (HOPG).

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Authors and Affiliations

G. Wielgoszewski
T. Gotszalk
M. Woszczyna
P. Zawierucha
E. Zschech
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Abstract

The Netherlands has a long tradition in water management, mainly stemming from the geography of the country. The ‘struggle with water’ has been organised from medieval times by the water boards (waterschappen), which are the oldest democratic institutions in the Netherlands. Nowa-days the water boards, 27 in the whole of the Netherlands, are not only responsible for flood protec-tion and regulation of water levels, but for water quality management and waste water treatment as well. In the years in which the WFD implementation has been underway in the Netherlands, several issues have arisen. Cooperation between all levels of government is key. This requires as clear as possible divisions of competences between the various parties involved. It also takes much time, es-pecially in a process in which many matters have to be invented ‘on the fly’, such as criteria for des-ignating water bodies, ecological standards, and the formulation of MEP and GEP.

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Authors and Affiliations

Thomas Ietswaart
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Abstract

Results of a research on influence of chromium, molybdenum and aluminium on structure and selected mechanical properties of Ni-Mn-Cu cast iron in the as-cast and heat-treated conditions are presented. All raw castings showed austenitic matrix with relatively low hardness, making the material machinable. Additions of chromium and molybdenum resulted in higher inclination to hard spots. However, a small addition of aluminium slightly limited this tendency. Heat treatment consisting in soaking the castings at 500 °C for 4 h resulted in partial transformation of austenite to acicular, carbon-supersaturated ferrite, similar to the bainitic ferrite. A degree of this transformation depended not only on the nickel equivalent value (its lower value resulted in higher transformation degree), but also on concentrations of Cr and Mo (transformation degree increased with increasing total concentration of both elements). The castings with the highest hard spots degree showed the highest hardness, while hardness increase, caused by heat treatment, was the largest in the castings with the highest austenite transformation degree. Addition of Cr and Mo resulted in lower thermodynamic stability of austenite, so it appeared a favourable solution. For this reason, the castings containing the highest total amount of Cr and Mo with an addition of 0.4% Al (to reduce hard spots tendency) showed the highest tensile strength.

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Authors and Affiliations

Daniel Medyński
ORCID: ORCID
A. Janus
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Abstract

Introduction: Seasonal variation has been observed for bacterial and viral infections (e.g., COVID-19 [1]), but also for numerous cardiac problems. However, little information is available on the seasonality of infectious endocarditis (IE), a rare disease that is usually linked to a bacterial origin. Data from the Polish population are lacking.
Materials and Methods: Our retrospective study focused on the identification of patients with IE, who were hospitalized at the University Hospital in Krakow between 2005–2022. For this purpose, we searched the medical records system using the ICD-10 code. We decided to divide our patients into four groups (winter, spring, summer, autumn), based on the date of admission to the hospital. Comparison of the distribution of IE incidents by season was performed with the ch2 test.
Results: One hundred and ten patients were included in the study (median age 62.5 years (range 20–94), 72 men (65.45%)). The left native valve IE was diagnosed in 49% of the patients, the prosthetic valve IE in 16%, the right valve IE in 27% and the implantable cardiac electronic devices IE in 12% of the subjects. The outcomes comprised of cardiac surgery (n = 53), embolism (n = 16), death (n = 15) and metastatic infections (n = 5). No differences in the incidence of IE by season were observed.
Conclusions: In the preliminary observation of IE cases of patients admitted to the University Hospital in Krakow, Poland no seasonal pattern of IE was detected. Therefore, IE should be taken into account in the differential diagnosis at any time of the year.
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Authors and Affiliations

Anna Tofilska
1
Katarzyna Zięba
1
Andrzej Surdacki
2
Marek Rajzer
3
Agnieszka Olszanecka
3

  1. Students’ Scientific Group at the First Department of Cardiology, Interventional Electrocardiology and Hypertension, Jagiellonian University Medical College, Kraków, Poland
  2. Second Department of Cardiology, Faculty of Medicine, Jagiellonian University Medical College, Kraków, Poland
  3. First Department of Cardiology, Interventional Electrocardiology and Hypertension, Jagiellonian University Medical College, Kraków, Poland
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Abstract

Long-duration human space missions require intelligent regenerative life support systems that can recycle resources and automatically manage failures. This paper explores using Petri nets to model the reliability and complex interactions of such closed-loop systems. An architecture consisting of primary systems, backups, and consumable reserves is outlined. The automation system that controls everything is described. Petri nets can capture concurrency, failure modes, redundancy, and dynamic behavior. A modular modeling methodology is presented to develop hierarchical Petri net models that scale in fidelity. Elementary fragments represent failures and redundancy. Subsystem modules can be substituted for more detailed models. Analysis and simulation assess system reliability and failure response. This supports designing ultra-reliable systems to safely sustain human life in space.
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Authors and Affiliations

Igor Kabashkin
1
Sergey Glukhikh
1

  1. Transport andTelecommunication Institute, Latvia
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Abstract

Rotational seismology is one of the fastest developing fields of science nowadays with strongly recognized significance. Capability of monitoring rotational ground motions represents a crucial aspect of improving civil safety and efficiency of seismological data gathering. The correct sensing network selection is very important for reliable data acquisition. This paper presents initial data obtained during the international research study which has involved more than 40 various rotational sensors collected in one place. The key novelty of this experiment was the possibility to compare data gathered by completely different rotational sensors during artificially generated ground vibrations. Authors collected data by four interferometric optical fiber sensors, Fiber-Optic System for Rotational Events & Phenomena Monitoring (FOSREM), which are mobile rotational seismographs with a wide measuring range from 10-7 rad/s up to even few rad/s, sensitive only to the rotational component of the ground movement. Presented experimental results show that FOSREMs are competitive in rotational events recording compared with the state-of-the-art rotational sensors but their operation still should be improved.
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Bibliography

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Authors and Affiliations

Anna T. Kurzych
1
ORCID: ORCID
Leszek R. Jaroszewicz
1
ORCID: ORCID
Michał Dudek
1
ORCID: ORCID
Bartosz Sakowicz
2
ORCID: ORCID
Jerzy K. Kowalski
3
ORCID: ORCID

  1. Institute of Technical Physics, Military University of Technology., 2 gen. S. Kaliskiego St., Warsaw 00-908, Poland
  2. Dep. of Microelectronics and Computer Science, Lodz University of Technology, 221/223 Wólczańska St., Lodz 90-924, Poland
  3. Elproma Elektronika Ltd., 13 Szymanowskiego St., Łomianki 05-092, Poland

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