Wyniki wyszukiwania - BazTech

1

Gwiazda Polski – ambitny projekt z udziałem Wolfkego

Jarosz Jerzy

Postępy Fizyki

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2022

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T. 73, z. 2

34--41

PL

Artykuł poświęcony jest historii zdobywania i badań stratosfery, które często przebiegały nad wyraz dramatycznie. Na tym tle pokazany jest niezwykle ambitny projekt badań, którym kierował profesor Mieczysław Wolfke, a któremu miała służyć Gwiazda Polski - największy stratostat (balon stratosferyczny) świata.

EN

The article is devoted to the history of the conquest and research of the stratosphere, which was o en extremely dramatic. Against the background of this story, an extremely ambitious research project led by Professor Mieczysław Wolfke, and which was to be served by the Star of Poland – the world’s largest stratostat is shown.

2

Promieniowanie kosmiczne – w poszukiwaniu nieoczekiwanego

Wibig Tadeusz

Postępy Fizyki

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2021

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T. 72, z. 4

2--17

PL

Historia badań promieniowania kosmicznego od samego początku pełna jest niespodziewanych odkryć, które znacząco odmieniały zastane poglądy na świat. Sama koncepcja, że z kosmosu przychodzi do nas jakieś promieniowanie, wydawała się absurdalna, a co najmniej nieuzasadniona. Nikt nie spodziewał się tak olbrzymich energii cząstek, nikt „nie zamawiał” też mionów, nikt nie podejrzewał, że promieniowanie kosmiczne będzie docierało do powierzchni Ziemi w kaskadach liczących ponad miliardy pojedynczych cząstek na raz. Ale najdziwniejsze jest to, że jednak istnieli fizycy, którzy mieli tak niepoważne idee to właśnie dzięki nim dziś wiemy to, co wiemy. A w fizyce promieniowania kosmicznego jest jeszcze sporo zagadek czekających na rozwiązanie i wiele zupełnie niespodziewanych odkryć.

EN

From the very beginning, the history of cosmic rays research has been full of unexpected discoveries that have significantly changed the prevailing view of the world. he very idea that some kind of radiation was coming to us from outer space seemed ridiculous, to say the least, unjustified. No one expected such enormous particle energies, no one also “ordered” muons, no one suspected that cosmic rays would come to the earth’s surface in cascades of more than billions of individual particles at the same time. But the strangest thing is that there must nevertheless have been physicists who had such frivolous ideas, and it is thanks to them that we know what we know. And in cosmic ray physics there are still many enigmas waiting to be solved and many discoveries to be made, discoveries that are absolutely unexpected.

3

Combination of Wavelet Analysis and Artificial Neural Networks Applied to Forecast of Daily Cosmic Ray Impulses

Caswell J. M.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 15

55--63

EN

Artificial neural network modelling has proven incredibly effective in an impressively wide range of scientific disciplines. The combination of these various methods with wavelet decomposition signal processing has similarly proven to be a powerful development for statistical forecasting of a number of environmental processes. Space weather modelling and prediction has often been applied to forecasting of solar activity and that of the planetary magnetic field. However, prediction of cosmic ray impulses has seen little development in the context of neural network modelling. In the present study, a combination of wavelet neural networks was adapted from previous research in order to predict daily average values of cosmic ray impulses 30 days in advance. Additional comparison of both neural network and linear regression modelling with and without wavelet decomposition was conducted for further demonstration of increased accuracy with wavelet neural networks in a simple input-output fitting model.

4

Reduction of silicon photomultipliers thermal generation in self-coincidence system applied in low level light measurements

Baszczyk M., Dorosz P., Głąb S., Kucewicz W., Mik Ł.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2014

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Vol. 62, nr 3

505--510

EN

The paper presents method for thermal generation reduction in low level light applications, especially where measured phenomena have random character. The algorithm was developed basing on cosmic ray measurements. The main parts of the system are: Silicon Photomultipliers (SiPM), front-end ASIC for amplifying and shaping signals. SiPM is a very sensitive device which can detect single photons. Comparing to a standard photomultiplier SiPM has a compact size, low operating voltage and it is immune to an electromagnetic field. Thermally generated signals are disadvantage of SiPM. This paper presents the measurement method to reduce influence of thermal generation.

5

A novel method for calibration and monitoring of time synchronization of TOF-PET scanners by means of cosmic rays

Silarski M., Czerwiński E., Bednarski T., Moskal P., Białas P., Kapłon Ł., Kochanowski A., Korcyl G., Kowal J., Kowalski P., Kozik T., Krzemień W., Molenda M., Niedźwiecki S., Pałka M., Pawlik M., Raczyński L., Rudy Z., Salabura P., Gupta-Sharma N., Słomski A., Smyrski J., Strzelecki A., Wiślicki W., Zieliński M., Zoń N.

Bio-Algorithms and Med-Systems

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2014

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Vol. 10, no. 1

19--25

EN

All of the present methods for calibration and monitoring of time-of-flight positron emission tomography (TOF-PET) scanner detectors utilize radioactive isotopes, such as 22Na or 68Ge, which are placed or rotate inside the scanner. In this article, we describe a novel method based on the cosmic rays application to the PET calibration and monitoring methods. The concept allows to overcome many of the drawbacks of the present methods and it is well suited for newly developed TOF-PET scanners with a large longitudinal field of view. The method enables also the monitoring of the quality of the scintillator materials and in general allows for the continuous quality assurance of the PET detector performance.

6

Metody usuwania zakłóceń podczas pomiarów polowych widm Ramana

Kwiatkowski A., Smulko J.

Pomiary Automatyka Kontrola

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2013

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R. 59, nr 4

281--283

PL

W pracy zostały scharakteryzowane źródła zakłóceń występujące podczas pomiarów widm Ramana w warunkach polowych oraz sposoby redukcji ich wpływu na jakość rejestrowanych widm. Zaprezentowano wpływ czasu integracji na jakość rejestrowanych widm w przypadkach, gdy szumy własne spektrometru mają składową typu 1/f, dominującą w zakresie małych częstotliwości. Przedstawiono także wyniki uzyskane podczas pomiarów z detekcją synchroniczną, stosowaną w przenośnych spektrometrach Ramana, w pomiarach przy silnym oświetleniu zewnętrznym.

EN

Raman spectrometers are devices which allow immediate and contactless identification of the examined substances. Detection is possible without any sample preparation, even from a distance or via a transparent package, like glass or plastic vials. These features make the Raman spectra measurement technique popular. Therefore it requires continuous development to get better results. Chemicals detection is based on comparison of a registered Raman spectrum with the reference spectra stored in a database. The algorithm which compares the spectra indicates the substances (one or even a few) having the most similar (according to the applied criterion) spectrum to the Raman spectrum of the investigated chemical. The reference database is created in a laboratory by using precise Raman Spectrometers of high resolution and low noise level. Field measurements of the Raman spectra are usually made by a less accurate device and suffer from external interferences. Therefore an additional procedure for noise and interference dumping is necessary. The paper outlines the sources of noise and interference contaminating Raman spectra. The selected methods for their suppression are discussed. The advantage of synchronous detection measurements at ambient light is shown. Finally, the impact of the time integration on the spectra quality, when inherent noise of a spectrometer has a dominant 1/f component at low frequency range is described.

7

Ionization of the earth's atmosphere by solar and galactic cosmic rays

Usoskin I. G., Desorgher L., Velinov P., Storini M., Flückiger E., Bütikofer R., Kovaltsov G. A.

Acta Geophysica

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2009

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Vol. 57, no. 1

88-101

EN

A brief review of the research of atmospheric effects of cosmic rays is presented. Numerical models are discussed, that are capable to compute the cosmic ray induced ionization at a given location and time. Intercomparison of the models, as well as comparison with fragmentary direct measurements of the atmospheric ionization, validates their applicability for the entire atmosphere and the whole range of the solar activity level variations. The effect of sporadic solar energetic particle events is shown to be limited on the global scale, even for the most severe event, but can be very strong locally in polar regions, affecting the physical-chemical properties of the upper atmosphere, especially at high altitudes. Thus, a new methodology is presented to study cosmic ray induced ionization of the atmosphere in full detail using realistic numerical models calibrated to direct observations.

8

Comparison of Earth's magnetospheric magnetic field models in the context of cosmic ray physics

Desorgher L., Flückiger E., Bütikofer R., Storini M., Kalegaev V.

Acta Geophysica

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2009

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Vol. 57, no. 1

75-87

EN

Over the last two decades, models of the Earth’s magnetospheric magnetic field have been continuously improved to describe more precisely the different magnetospheric current systems (magnetopause current, symmetric and partial ring currents, tail currents and field aligned currents). In this paper we compare the different Tsyganenko models and the Alexeev and Feldstein model in the context of cosmic ray physics. We compare the vertical cutoff rigidity and asymptotic direction of vertical incidence obtained with these models for the January 20, 2005, ground level enhancement and for the big magnetic storm of April 6, 2000. For the event of January 20, 2005, we study the impact of the differences in asymptotic direction obtained with the models on the radiation dose computation at aircraft altitude. For the magnetic storm of April 6, 2000, we discuss the importance of the different magnetospheric current systems in causing cutoff rigidity variations. Finally we summarise the advantages and drawbacks of the different models in the context of space weather.

9

Radiation chemistry in exploration of Mars

Zagórski Z.

Nukleonika

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2005

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Vol. 50,suppl.2

59-63

EN

Problems of exploration of Mars are seldom connected with radiation research. Improvements in such approach, more and more visible, are reported in this paper, written by the present author working on prebiotic chemistry and origins of life on Earth. Objects on Mars subjected to radiation are very different from those on Earth. Density of the Martian atmosphere is by two orders smaller than over Earth and does not protect the surface of Mars from ionizing radiations, contrary to the case of Earth, shielded by the equivalent of ca. 3 meters of concrete. High energy protons from the Sun are diverted magnetically around Earth, and Mars is deprived of that protection. The radiolysis of martian "air" (95.3% of carbon dioxide) starts with the formation of CO2 +, whereas the primary product over Earth is N2 + ionradical. The lack of water vapor over Mars prevents the formation of many secondary products. The important feature of Martian regolith is the possibility of the presence of hydrated minerals, which could have been formed milliards years ago, when (probably) water was present on Mars. The interface of the atmosphere and the regolith can be the site of many chemical reactions, induced also by intensive UV, which includes part of the vacuum UV. Minerals like sodalite, discovered on Mars can contribute as reagents in many reactions. Conclusions are dedicated to questions of the live organisms connected with exploration of Mars; from microorganisms, comparatively resistant to ionizing radiation, to human beings, considered not to be fit to manned flight, survival on Mars and return to Earth. Pharmaceuticals proposed as radiobiological protection cannot improve the situation. Exploration over the distance of millions of kilometers performed successfully without presence of man, withstands more easily the presence of ionizing radiation.