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1

Temperature effect on frequencies of a tapered triangular plate

Khodiya Akash, Sharma Amit

Journal of Applied Mathematics and Computational Mechanics

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2021

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Vol. 20, nr 1

37-48

EN

The two dimensional temperature effect on the vibration is computed for the first time for a clamped triangular plate with two dimensional thickness. In the study we focused on isosceles, right-angled and scalene triangles only. The first three modes of vibration are computed on different variations of plate parameters using the Rayleigh-Ritz method. The objective of the study is to reduce the frequency of the plates. A comparative study of the frequencies with other available results well presents the objective of the study.

2

Temperaturowe efekty podwójnej fluorescencji 4-(5-heptylo-1,3,4-tiadiazol-2-ilo)benzeno- -1,3-diolu (C7)

Matwijczuk A., Karcz D., Kluczyk D., Matwijczuk A., Gładyszewska B., Niewiadomy A, Gagoś M.

Przemysł Chemiczny

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2017

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T. 96, nr 7

1511--1514

PL

Dokonano pomiarów emisji fluorescencji stacjonarnej dla 4-(5-heptylo-1,3,4-tiadiazol-2-ilo) benzeno-1,3-diolu (C7) w środowisku wodnym. Dla C7 rozpuszczonego w roztworach o niskim pH (poniżej 7) i w zakresie temp. 20-40°C, zaobserwowano dwa wyraźnie rozdzielone pasma emisji fluorescencji. Natomiast dla C7 w tym samym zakresie pH lecz w temp. powyżej 40°C obserwowano już tylko pojedyncze pasmo fluorescencji. W przypadku widm rezonansowego rozpraszania światła RLS obserwowano silny sygnał w zakresie temperatur, w którym widma emisji fluorescencji wykazywały efekt podwójnej fluorescencji. Wraz ze wzrostem temperatury i jednoczesnym zanikiem jednego z pasm fluorescencji, zanikała również intensywność sygnału RLS. Biorąc pod uwagę wcześniejsze badania związków z tej grupy zauważono, że efekty te mogą być związane z efektami agregacyjnymi. Technika spektroskopii fluorescencyjnej umożliwiła szybką analizę zmian molekularnych w badanych związkach, zaowocować to może zaprojektowaniem nowej klasy pochodnych o właściwościach umożliwiających ich potencjalne praktyczne zastosowanie jako sondy fluorescencyjne.

EN

Aq. solns. of 4-(5-heptyl-1,3,4-thiadiazo-2-yl)benzene-1,3-diol (C7) showed two well-resolved fluorescence bands at 20-40°C and pH 1-7. At the temps. exceeding 40°C, only a single fluorescence max. was obsd. The resonance light scattering spectra measured at 20-40°C showed a strong signal, which decreased with the temp. increase. The data were consistent with previous reports and confirmed a mol. aggregation-related nature of the fluorescence effects. The possibility of a quick fluorescence spectroscopy- based anal. of intra- and intermol. transformations was evidenced.

3

Krótki przegląd zastosowań cyklodekstryn dotyczący analiz farmaceutycznych, biomedycznych oraz środowiskowych

Lamparczyk H., Chmielewska A., Zarzycki P. K.

Camera Separatoria

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2013

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Vol. 5, No. 1

27--34

PL

Przedstawiona praca jest ostatnim projektem naukowym nad jakim pracował Profesor Henryk Lamparczyk, który przedwcześnie zmarł 16 listopada 2012 roku w wieku 65 lat. Przeglądowa praca o charakterze dydaktyczno-poglądowym dotyczy zastosowania cyklodekstryn w bioanalityce i została napisana w oparciu o prace opublikowane przez Profesora i współpracowników. Niniejsza wersja bazuje na artykule pt. “Natural cyclodextrins: development in theory, chromatography and pharmacy, A. Chmielewska, H. Lamparczyk;” opublikowanej w materiałach Supramolecular Chemistry and Advanced Materials. Wojciech Macyk & Konrad Szaciłowski, Editors, Kraków Jagielonian University 2007, pages 131-136 i jest rozszerzona o wiadomości przedstawione w najnowszych publikacjach dotyczących zastosowania cyklodekstryn w HPLC, głównie do oznaczeń sterydów i analiz przesiewowych próbek środowiskowych.

EN

This is the last research project of Professor Henryk Lamparczyk that prematurely passed away at age 65. In his intention it was to prepare a demonstrative review paper concerning application of cyclodextrins in bioanalysis, based on his and co-worker contributions to the field of supramolecular chemistry. This version of paper is based on the manuscript entitled “Natural cyclodextrins: development in theory, chromatography and pharmacy, A. Chmielewska, H. Lamparczyk;” that was published in Supramolecular Chemistry and Advanced Materials. Wojciech Macyk & Konrad Szaciłowski, Editors, Kraków Jagielonian University 2007, pages 131-136 and now is extended for the latest papers concerning HPLC application of cyclodextrins for steroids analysis and environmental samples screening. The main tools applied in described investigations were various chromatographic techniques such as gas chromatography (GC), high performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Topics such as structure-retention relationships, equilibrium constants between cyclodextrins (CDs) and guest molecules, thermodynamics and CDs separations were discussed. Additionally few examples of practical applications of CDs in pharmacy as well as biomedical and environmental analysis are given.

4

Effects of laser radiation on the cementitious materials - three case studies

Klemm A. J., Rożniakowski K.

Fizyka Budowli w Teorii i Praktyce

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2009

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T. 4

79-84

EN

Laser processing is unarguably associated with some alterations of cementitious materials' geometrical microstructure and chemical composition. Since high temperature is involved in the laser cleaning process, the chemical composition of surfaces may change, followed by crack development and subsequent changes of roughness. The relationship between laser treatment and substrate parameters is a two-way relationship. The great variation in absorptivity of highly developed surfaces of cementitious materials results in substantial differences in their responses to laser irradiation. Paper presents selected results of three investigations on the effect of laser radiation on characteristics of porous cementitious materials.

5

Modelowanie efektów temperaturowych w procesach hydraulicznego szczelinowania

Szott W., Kwilosz T.

Nafta-Gaz

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2004

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R. 60, nr 9

479-485

PL

Temperatura płynu szczelinującego jest jednym z podstawowych czynników determinujących jego dobór oraz podstawowe charakterystyki. Wniosek ten jest szczególnie istotny dla powszechnie stosowanych nienewtonowskich żeli o lepkości i innych właściwościach transportowych silnie zależnych od temperatury oraz odwiertów udostępniających formacje o temperaturze znacznie różniącej się od temperatury zatłaczanego płynu. W dotychczasowej praktyce projektowania zabiegów szczelinowania, prowadzonych w szczególności przez grupę specjalistów w INiG, nie były uwzględniane efekty zmiennej temperatury podczas zabiegu, ze względu na brak efektywnych modeli pozwalających na ocenę ilościowego charakteru tego zjawiska. W pracy przeprowadzono szczegółową analizę zjawisk transportu ciepła w trakcie zabiegu hydraulicznego szczelinowania w warunkach złożowych. Sformułowano również i przetestowano modele pozwalające na ilościowy opis występujących efektów. Efektem pracy jest propozycja praktycznej metody prognozowania dynamicznych zmian temperatury podczas zabiegu stymulacji odwiertu.

EN

The temperature of injection fluids used for fracturing strongly determines its effectiveness and basic characteristics. In particular, it is especially significant for: the application of non-Newtonian gels whose viscosity and other transport properties are temperature dependent and deep wells completed in rocks of elevated temperatures high above that of injected fluids. Designs of fracturing treatment performed by experts Polish Oil & Gas Institute have not take into account effects of such fluids varying temperature so far due to the lack of proper simulations tools. This paper tries to fill the gap by providing a simplified but effective software to model those thermal effects. To this aim relevant physical phenomena are analyzed, corresponding mathematical models are formed, their original solution are found and implemented in computer programs.

6

Thermal effects due to variation of pressure in molten polymers

Kiljański T., Budzyński P., Gałąź R.

Polish Journal of Chemical Technology

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2003

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Vol. 5, nr 4

58-59

EN

The variations of temperature during compression of molten polymers: polyethylene, methyl polymethacrylate, hard and plasticized polyvinyl chloride compounds were investigated in the range of pressure up to about 1600 bars. Their specific heat and coefficient of thermal expansion were also evaluated. The measured increase of temperature proved similar for all materials but they differ considerably from the values calculated from theoretical equation 1. It seems that eq. 1 does not take into account some phenomena which influence the thermal effects of compression but are not connected with the coefficient of thermal expansion.

7

Ozone synthesis under barrier discharge at high and low concentrations

Petryk J., Jodzis S., Zarębski W.

Polish Journal of Chemical Technology

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2002

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Vol. 4, nr 2

28-32

EN

The influence of discharge parameters on the obtained ozone concentration has been analysed by means of a simple model of synthesis under silent discharge conditions. The overall rate of ozone synthesis decreases with an increase in the ozone concentration. The maximum content of ozone is obtained when in specified conditions the rate of the reaction, in which ozone is formed will be equal with that of the reactions causing its decomposition. It has been found that for the model assumed, the temperature is the main parameter which influences the maximum ozone concentrations. The calculation models are often simplified, with omitting the endothermic effect of the ozone synthesis and without taking into account the rise in average molar specific heat of a gas mixture resulting from the presence of ozone in it besides oxygen. Calculations taking into account and then omitting the above parameters were carried out. It appears that their influence is insignificant, so the simplification of the model does not cause a significant error. This especially refers to the synthesis at low concentrations of ozone. Many times it has been experimentally found that at low ozone concentrations the better process efficiency, i.e. a little higher ozone concentration is obtained when the synthesis proceeds at a higher temperature (with maintaining the other experiment conditions invariable). This anomaly has been explained on the basis of experimental results and calculations using a simple model of the process. model of synthesis under silent discharge conditions. The overall rate of ozone synthesis decreases with an increase in the ozone concentration. The maximum content of ozone is obtained when in specified conditions the rate of the reaction, in which ozone is formed will be equal with that of the reactions causing its decomposition. It has been found that for the model assumed, the temperature is the main parameter which influences the maximum ozone concentrations. The calculation models are often simplified, with omitting the endothermic effect of the ozone synthesis and without taking into account the rise in average molar specific heat of a gas mixture resulting from the presence of ozone in it besides oxygen. Calculations taking into account and then omitting the above parameters were carried out. It appears that their influence is insignificant, so the simplification of the model does not cause a significant error. This especially refers to the synthesis at low concentrations of ozone. Many times it has been experimentally found that at low ozone concentrations the better process efficiency, i.e. a little higher ozone concentration is obtained when the synthesis proceeds at a higher temperature (with maintaining the other experiment conditions invariable). This anomaly has been explained on the basis of experimental results and calculations using a simple model of the process.