Wyniki wyszukiwania - Biblioteka Nauki

1

Speed Of Sound And Related Thermodynamics Functions In And Ideal Mixture

100%

Marczak W.

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tom Vol. 25

193-200

EN

Deviation of experimental speeds of sound from the values predicted by different methods are sometimes interpreted in terms of molecular interactions. To this end, reference states must have clear physical meaning. In this work, two reference models were compared: a thermodynamically ideal solution and a model of additive passage times. Physical background of the differences was discussed. The role of an entropy changes in an medium compressed and decompressed by an acoustic wave was printed out. A hypothetical binary mixture of perfect gases served as an example of the discussed issue.

2

Nowe stwierdzenie Semblis phalaenoides [LINNAEUS, 1758] Trichoptera: Phrygaenidae] w Biebrzańskim Parku Narodowym

63%

Marczak D. , Marczak W.

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nr 4

280

3

Korelacja między prędkością propagacji ultradźwięków a Entalapią mieszania wodnych roztworów amin alifatycznych i cyklicznych

63%

Marczak W. , Ernst S.

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tom Vol. 19

179-184

EN

The relationship between the speed of ultrasound in a fluid (c) and its enthalapy (H) is given by the following equations: c= square root V2 /(KSM) (the Laplace formula), V=(partial differential H/partial differential p)s and Ks = -(partial differential2/partial differential p 2)s , where V - molar volume, KS - molar adiabatic compres molar mass of the substance, p - pressure and S - entropy. Thus, since for the calculation the speed of sound from the corresponding thermodynamic functions the equation of state has to be known, which most often is not the case, reliable correlations between the speed thermodynamic characteristics seem to be of interest. An attempt was undertaken to correlation of this type for 13 binary water - amine mixtures. The correlation of the of the speed isotherms with the first enthalpies of solution in water (at 298.15 K; based on the literature data) is shown in Figure 3. Some correlations are also observed between the) of sound and the enthalpies of mixing (Figs 4 and 5). The reported correlations may be used for a preliminary prediction of the enthalapy mixing from ultrasonic data. Calorimetric measurements are rather time-consuming and difficult in comparison with the ultrasonic ones, thus an estimation of the enthalpy effect in this way, although being only a rough one, could be useful both in practical application in calorimetric studies.

4

The Effect of Deuteron Substitution in Wated on the Speed of Sound in Aqueus Solutions of 1-Propanol

63%

Marczak W. , Spurek M.

|

2001

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tom Vol. 22

157-163

EN

Aqueous solutions of 1-alkans are often regarded as model systems in the investigation of hydration phenomena. The deuteron substitution in water changes the properties of aqueous alkans solutions as well as thode of such more complicated systems: cells, tissues and organs of living organisms. In this work, the speed of sound in mixtures of 1-propanol with D2O was compared with the speeds in binary solutions of methanol, ethanol and 1-propanol in H2O. A somewhat more pronounced hydrophobic hydration in D2O than in H2O is manifested by an effect similar to that resulting from the elongation of the alcohol molecule.

5

Słodko i zdrowo

63%

Ordyniak A. , Marczak W.

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nr 1

6

Hałas przy spawaniu łukowym w osłonie gazów

51%

Matusiak J. , Wyciślik J. , Szłapa P. , Marczak W.

|

2015

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tom Vol. 82, nr 3

202--211

PL

W artykule przedstawiono badania wpływu warunków technologicznych procesu spawania łukowego elektrodą topliwą w osłonie gazów na poziom dźwięku generowanego w trakcie procesu. Omówiono wyniki badań dla wybranych metod spawania; MAG, MAG Pulse, CMT (Cold Metal Transfer), ColdArc, RapidArc, MAG Double Pulse, AC Pulse. Analizowano zależności pomiędzy warunkami materiałowo-technologicznymi spawania a poziomem ciśnienia akustycznego dźwięku A oraz poziomem ciśnienia akustycznego w 1/3 oktawowych pasmach widma hałasu słyszalnego i ultradźwiękowego.

EN

The article presents tests focused on the effect of gas-shielded metal arc welding technological conditions on the level of sounds generated during welding processes. The study discusses the results of tests for welding methods: MAG, MAG pulse, CMT (Cold Metal Transfer), ColdArc, RapidArc, MAG Double Pulse, AC Pulse. The analysis was concerned with the correlations between welding material-technological conditions and the acoustic pressure level of sound A and the acoustic pressure level in the 1/3 octave bands of audible and ultrasonic noise spectrum.

7

A Computer Program for the Calculation of Thermodynamic Quantities for Liquids from the Speed of Sound at Elevated Pressures

51%

Marczak W. , Dzida M. , Ernst S.

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1999

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tom Vol. 20

159-164

8

Acoustic and Thermodynamic Properties of Ethanol, 1-Propanol and 1-Hexanol at Temperatures from 293 to 318 K and Pressures up to 90 MPa

51%

Dzida M. , Marczak W. , Ernst S.

|

1999

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tom Vol. 20

43-47

9

Experimental Tests on the Effect of Gas-shielded Arc Welding Technological Conditions on Sound Level

51%

Matusiak J. , Wyciślik J. , Szłapa P. , Marczak W.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2014

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tom Vol. 58, No. 5

159--162

EN

During various welding processes workers are exposed to activities connected with audible and ultrasonic noise. In spite of the continuous development and improvement of production means, robotisation of welding works and the development of measures protecting workers against noise, the exposure to noise continues to be one of the major issues in welding engineering. The article presents experimental tests focused on the effect of gas-shielded metal arc welding technological conditions on the level of sounds generated during welding processes. The study discusses the results of tests performed for 7 selected gas-shielded arc welding methods, i.e. MAG, MAG Pulse, CMT (Cold Metal Transfer), ColdArc, RapidArc, MAG Double Pulse and AC Pulse. The test-related analysis was concerned with the correlations between welding material-technological conditions and the acoustic pressure level of sound A as well as the acoustic pressure level in the 1/3 octave bands of audible and ultrasonic noise spectrum.

PL

Podczas różnych prac spawalniczych pracownicy narażeni są na pracę związaną z hałasem słyszalnym i ultradźwiękowym. Pomimo ciągłego rozwoju i doskonalenia środków produkcji, robotyzacji prac spawalniczych oraz rozwoju środków ochrony pracowników przed pracą w hałasie, można stwierdzić, że ekspozycja na hałas w spawalnictwie stanowi wciąż jeden z głównych problemów. W artykule przedstawiono badania eksperymentalne wpływu warunków technologicznych procesu spawania łukowego elektrodą topliwą w osłonie gazów na poziom dźwięku generowanego w trakcie procesu. Omówiono wyniki badań dla wybranych 7 metod spawania łukowego w osłonie gazów: MAG, MAG Pulse, CMT (Cold Metal Transfer), ColdArc, RapidArc, MAG Double Pulse i AC Pulse. Analizowano zależności pomiędzy warunkami materiałowo-technologicznymi spawania a poziomem ciśnienia akustycznego dźwięku A oraz poziomem ciśnienia akustycznego w 1/3 oktawowych pasmach widma hałasu słyszalnego i ultradźwiękowego.