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OALib Journal期刊

ISSN: 2333-9721

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( 2023 )

( 2022 )

( 2021 )

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Wet Oxidation of Dairy Sewage
Klara Piotrowska , Miros aw Imbierowicz , Andrzej Chacuk
Ecological Chemistry and Engineering S , 2012, DOI: 10.2478/v10216-011-0003-1
Abstract: Results of kinetic studies on the process of wet oxidation of dairy sewage are presented. Experiments were carried out in a stirred batch tank reactor at the oxygen partial pressure equal to 1 MPa and at temperature ranging from 473 to 523 K. Dairy sewage was subjected to oxidation at a natural pH close to 4. The efficiency of decomposition of organic compounds was estimated on the basis of TOC measurement. The highest TOC reduction rate reached 79.6%. A kinetic model of the process was proposed and its parameters were determined experimentally. Good agreement of the experimental and calculated results was obtained.
Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique
Marta Siemieniec , Hanna Kierzkowska-Pawlak , Andrzej Chacuk
Ecological Chemistry and Engineering S , 2012, DOI: 10.2478/v10216-011-0006-y
Abstract: The pseudo-first-order rate constants (kOV) for the reactions between CO2 and diethanolamine have been studied using the stopped-flow technique in an aqueous solution at 293, 298, 303 and 313 K. The amine concentrations ranged from 167 to 500 mol·m-3. The overall reaction rate constant was found to increase with amine concentration and temperature. Both the zwitterion and termolecular mechanisms were applied to correlate the experimentally obtained rate constants. The values of SSE quality index showed a good agreement between the experimental data and the corresponding fit by the use of both mechanisms.
Discrete Time Risk Model Financed by Random Premiums  [PDF]
Andrzej Korzeniowski
Journal of Mathematical Finance (JMF) , 2022, DOI: 10.4236/jmf.2022.121008
Abstract: We propose a novel actuarial risk model which, unlike the classical Crámer-Lundberg model, incorporates a stream of random premiums that offset random claims. A key feature of the model is a discrete time accounting of premiums and claims flow, whereby lending itself to random walk type analysis. We derive various estimates of ruin probability thereby providing an effective method of risk assessment over a future time horizon.
New Nanocrystalline Matrix Materials for Sintered Diamond Tools  [PDF]
Janusz Konstanty, Andrzej Romanski
Materials Sciences and Applications (MSA) , 2012, DOI: 10.4236/msa.2012.311113
Abstract: The work presents the possibility of substitution of expensive, wear resistant Co-WC powders, that have been traditionally used in the production of sintered diamond tools, with cheap iron-base counterparts manufactured by ball milling. It has been shown that ball-milled Fe-Ni-Cu-Sn-C powders can be consolidated to a virtually pore-free condition by hot pressing at 900 ℃. The as-consolidated material has nanocrystalline structure and is characterised by a combination of high hardness, mechanical strength and excellent resistance to abrasion. Its properties can be widely modified by changing the milling conditions.
Nuclear Power for Poland  [PDF]
Andrzej G. Chmielewski
World Journal of Nuclear Science and Technology (WJNST) , 2013, DOI: 10.4236/wjnst.2013.34021
Abstract:

The present situation in Poland and Europe, regarding electric power generation by source, is discussed in the paper. The results of the implementation of EU competitive-low-carbon economy policy in some most developed countries in the continent, have given already good experimental data for evaluation of this strategy. Analysis of the reports provided by official sources for Germany, Denmark and Finland is a base for EU energy policy evaluation. The combustion technologies will be a main energy sources for many years from now. Therefore effects of fossil fuels and biomass combustion on the environment are presented briefly. Finally, the developments regarding Polish Nuclear Energy Programme are overviewed.

Wavelet Transform in Vibroacoustic Diagnostics of Combustion Engines  [PDF]
Radoslaw Wrobel, Andrzej Kazmierczak
Engineering (ENG) , 2019, DOI: 10.4236/eng.2019.117028
Abstract: This article discusses the use of wavelet decomposition in the diagnostics of vibrometric signals of an engine. Apart from presenting the possibility of using wavelets in diagnostics, the authors take up the subject of the applicability range of processing for stationary signals, which until now has been reserved for non-stationary signals. A unified definition of signal stationarity has been proposed, which is not based on statistics. The authors presented methods of wavelet decomposition of a vibrometric signal of combustion engine vibrations, measured with the use of LDV (Laser Doppler Vibrometry). Laser measurements allow for studying an object without “touching” its housing. Basing on the relative velocity of engine vibrations, the authors indicate how reliable vibrations are in diagnostics. Despite higher costs, this measurement method gives better results (for specific cases) than acoustic studies. Transform-wavelet decomposition is a solution hardly ever used in machine diagnostics; it is more often applied in medicine and image recognition. The authors presented the differences that can be obtained for different levels of decomposition, and also presented the impact on the engine condition assessment through the use of filtering (windowing) the signal before decomposition.
Adaptive Risk Hedging for Call Options under Cox-Ingersoll-Ross Interest Rates  [PDF]
Niloofar Ghorbani, Andrzej Korzeniowski
Journal of Mathematical Finance (JMF) , 2020, DOI: 10.4236/jmf.2020.104040
Abstract: We present a solution to the problem posed by Zhang et al. [1] regarding Call Option price CT under linear investment hedging for the stochastic interest rate modeled by a CIR Process. A closed form representation for CT by expected value of the path-integral along a square functional of n-dimensional Ornstein-Uhlenbeck process is derived. The method is suitable for Monte-Carlo simulation and illustrated by an example.
The Phenomenon of a Natural Thermonuclear Reactor  [PDF]
Andrzej Pawu？a
Journal of Geoscience and Environment Protection (GEP) , 2021, DOI: 10.4236/gep.2021.92006
Abstract: The study contains the justification of J.M. Herndon’s thesis about the existence of a thermonuclear reactor in the Earth’s core. A scenario of the formation of a spontaneous nuclear reactor is presented, referring to the universal law of gravity, to the relationship between matter and energy, and to the properties of plasma. The theoretical attitudes of the discussed phenomena and the relations between them can be called the Theory of the Primordial Forces of Nature. It includes the interactions of the gravitational field, the forces of the electromagnetic field, which determine the properties of matter, and the strong interactions resulting from the release of nuclear energy. Arguments for the thesis about the commonness of the phenomenon of thermonuclear reactors in space are presented. The second part of the article presents examples of geological phenomena that confirm the activity of a thermonuclear reactor in the center of the Earth.
Put Options with Linear Investment for Hull-White Interest Rates  [PDF]
Andrzej Korzeniowski, Niloofar Ghorbani
Journal of Mathematical Finance (JMF) , 2021, DOI: 10.4236/jmf.2021.111007
Abstract: We derive a Put Option price associated with selling strategy of the underlying security in a random interest rate environment. This extends Put Option pricing under linear investment strategy from the Black-Scholes setting to Hull-White stochastic interest rate model. As an application, Call Option price for the linear investment strategy in the Hull-White model is established. Our results address recent emergence of developing dynamic investment strategies for the purpose of reducing the investor risk exposure associated with European-type options.
The Problem of Natural Radioactive Elements  [PDF]
Andrzej Pawu？a
Journal of Geoscience and Environment Protection (GEP) , 2021, DOI: 10.4236/gep.2021.94011
Abstract: The article presents two opposing views on the origin of natural radioactive elements. According to a view based on the Big Bang Theory, the elements found on Earth were formed by the process of primary nucleosyntase 13.8 billion years ago, with the exception of uranium and other heavy elements that were formed billions of years later under stellar conditions. It follows from this view that throughout the existence of the earth, the global amount of uranium and other primary radionuclides is reduced as a result of natural decay. The reasoning of the proponents of the BB theory is as follows: if the global radioactivity decreases, the problem of the threat decreases and one only needs to get used to the newly discovered natural phenomenon. There are even official regulations that exclude ionizing radiation from radon in the calculation of the limit dose. The Primary Forces of Nature theory presents a completely different view. Considering the analogous influence of gravity on the formation of the globs of the solar system, the logical explanation of the phenomena of geological activity are thermonuclear processes, such as on the sun. Hence the conclusion that the elements chemical are now created in the core of the Earth in the process of thermonuclear synthesis. The problem is serious because there is an accelerated growth of new igneous matter containing the created elements, and the ionizing radiation of natural radionuclides is the main factor responsible for the radioactivity level of the human environment.
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