PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 9

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Wpływ metody pobierania próbek powietrza na jakość wyników oznaczeń
Kijak B., Juszkiewicz A.
Analityka : nauka i praktyka
|
2004
|
nr 1
25-27
PL
Problem jakości i czystości powietrza, którym oddychamy, został tak naprawdę zauważony po zaobserwowaniu fatalnych skutków zdrowotnych zjawiska smogu fotochemicznego, które miało po raz pierwszy miejsce w Los Angeles w latach czterdziestych i późniejszych.
2
Content available remote Determination of rate constants and activation energies for emission of organic compounds from polyoxymethylene
Choczyński M., Nęcki J. M., Juszkiewicz A.
Acta Chromatographica
|
2004
|
No. 14
37-48
EN
Emission of organic compounds from two types of polytrioxane (colorless and black-smoke pigmented) has been measured by using a 20-cm3 chamber connected directly to a gas chromatograph. Measurements were performed at 40, 60, and 80 C degrees at a flow rate of 0.45 cm3 min-1. High surface to volume ratio and a relatively large sample loop (3 cm3) enabled detection of signals from organic substances present at low concentrations (~μg cm-3). The results obtained revealed that for the pigmented polytri-oxane the rate of emission of organic compounds and the rate constants for the process were higher than for the colorless form. In contrast, the ac-tivation energy was slightly higher for emission of trioxane from the pig-mented material. For trioxepane emission activation energies were similar. Results show the pigment had no retardant activity on emission of organic compounds from the polymer. The activation energies determined for emis-sion of organic compounds were in the range 15 to 60 kJ mol-1. The rate constants (from 7.6 × 10-10 to 9.2 × 10-8 cm-2 s-1) suggest diffusion or de-sorption are occurring within the polymer matrix.
3
Absorption of Ultrasonic Waves in Aqueous Binary Mixtures of alfa-Cyclodextrin and Some Amphiphilic Substances
Balcerzak A., Płowiec R., Kiełczyński P., Juszkiewicz A.
Molecular and Quantum Acoustics
|
2002
|
Vol. 23
15-25
4
Rozprzestrzenianie się lotnych związków organicznych pochodzących ze źródeł komunikacyjnych
Juszkiewicz A., Kijak B.
Chemia i Inżynieria Ekologiczna
|
2002
|
Vol. 9, nr 1
115-124
PL
Oznaczono stężenia lotnych węglowodorów oraz sumaryczne stężenie lotnych związków organicznych w powietrzu atmosferycznym Krakowa na różnych wysokościach nad powierzchnią gruntu, w miejscach usytuowanych w sąsiedztwie źródeł komunikacji samochodowej. Próbki powietrza atmosferycznego pobierano do metalowych kanistrów z elektropolerowanej stali nierdzewnej i analizowano za pomocą chromatografu gazowego z detektorem płomieniowo-jonizacyjnym.
EN
Determination of volatile hydrocarbons and total concentration of volatile organic compounds in Krakow on different height above the ground level was deseribed. Samples were collected in 6 series between 02.12.1998 and 29.03.1999. Atmospheric air samples were collected into stainless steel canisters in places near to communication sources. The technique of cryogenic preconcentration was used. Samples were analized by capillary gas chromatograph Varian Star 3600CX with FID detector.
5
Content available remote Ultrasonic investigations of aqueus solutions of α-cyclodextrin and amphiphil substances having different "heads" and identic "tails"
Balcerzak A., Płowiec R., Kiełczyński P., Juszkiewicz A.
Archives of Acoustics
|
2002
|
Vol. 27, no. 4
361-371
EN
Velocity and absorption of ultrasonic waves in aqueuos solutions of a-cyclodextrin containing amphiphil substances with different ``heads" and identic ``tails" were carried out. As a result of the mutual interactions between a-cyclodextrin and the amphiphil substance the low frequency ultrasonic relaxation process has been established. Thermodynamic and kinetic parameters related to this process have been calculated. Obtained results have been discussed considering molecular structure of the amphiphil substances.
6
Content available remote Investigations of ultrasonic velocity and absorption in aqueous solutions of [alpha]- and ß-cyclodextrin with sodium alkyl sulfates. Part 2. ß-cyclodextrin systems
Balcerzak A., Płowiec R., Juszkiewicz A.
Archives of Acoustics
|
2001
|
Vol. 26, no. 1
51-63
EN
In second part of this work, velocity and absorption measurements of ultrasonic waves in aqueous solutions of ß-cyclodextrin containing different sodium alkyl sulfates are reported. One or two relaxation processes for these solutions have been established. Thermodynamic and kinetic parameters related to these processes have been calculated. The results have been compared with those obtained for solutions of ?-cyclodextrin and presented in Part 1 of this paper. Explanation of the origins of these processes has been proposed.
7
Content available remote Investigations of ultrasonic velocity and absorption in aqueous solutions of [alpha]- and ß-cyclodextrin with sodium alkyl sulfates. Part 1. [alpha]-cyclodextrin systems
Balcerzak A., Płowiec R., Juszkiewicz A.
Archives of Acoustics
|
2001
|
Vol. 26, no. 1
37-52
EN
In this part, the velocity and absorption measurements of ultrasonic waves in aqueous solutions of [alpha]-cyclodextrin containing different sodium alkyl sulfates are reported. One or two relaxation processes for these solutions have been established. Thermodynamic and kinetic parameters related to these processes have been calculated. In the second part, experimental results for ß-cyclodextrin will be reported and compared with those presented here.
8
Content available remote Gas chromatographic examination of the dispersion of VOCs emitted by motor vehicles in urban and semi-rural Kraków
Juszkiewicz A., Kijak B.
Acta Chromatographica
|
1999
|
No. 9
154-174
EN
Dispersion of volatile organic compounds around streets with heavy traffic in and outside Kraków has been analysed by taking samples of air at different distances from the source of pollution. The procedure used was based on the US EPA T0-14 method – samples of air were collected in SUMMA canisters, concentrated in a cryogenic trap and analysed by gas chromatography with flame-ionization detection. Among other uses, the results obtained enable: - estimation of the effect of motor roads on the composition of ambient air; - evaluation of the range of effects of road traffic by determining the dependence of concentration on distance over different terrain and under different atmospheric conditions; and determination of the "background" concentration of volatile organic compounds and the maximum concentrations to which road users are exposed.
9
Content available remote Absorption of ultrasonic waves in aqueous solutions of ?-cyclodextrin with alkylpyridinium or alkyltrimethylammonium bromides
Balcerzak A., Płowiec R., Juszkiewicz A.
Archives of Acoustics
|
1998
|
Vol. 23, no. 3
411-428
EN
Measurements of the absorption coefficient, alfa/f2, of aqueous solutions of ?-cyclodextrin with alkylpyridinium bromides CnH2n+1C5H4NBr or alkyltrimethylammonium bromides CnH2n+1N(CH3)3Br (n=8, 10, 12), were carried out at 15, 25, 35 and 45oC in the concentration range 0.01M to 0.04M and frequency range 1MHz to 150MHz. The occurrence of two ultrasonic relaxation processes has been noted. The obtained results have been compared with data published previously for sodium alkyl sulfates.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.