Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: potassium chlorate

Sortuj według:

Ogranicz wyniki do:

Kinetic Study of the Thermal Decomposition of Potassium Chlorate Using the Non-isothermal TG/DSC Technique

100%

Ravanbod M. , Pouretedal H. R. , Amini M. K. , Ebadpour R.

2016

tom Vol. 13, no. 2

505--525

The non-isothermal TG/DSC technique has been used to study the kinetic triplet of the thermal decomposition of potassium chlorate at different heating rates (5, 10, 15 and 20 °C•min−1). The DSC results showed two consecutive broad exothermic peaks after melting. The first peak contains a shoulder indicating the presence of at least two processes. The overlapped peaks were resolved by a peak fitting procedure, and the three resolved peaks were used for evaluation of the kinetic triplet for each step. The TG results also showed two consecutive mass losses after melting. The kinetics of the mass loss processes were studied using resolved DTG peaks. The activation energies were calculated using the KAS model-free method. The pre-exponential factor and the best kinetic model for each step were determined by means of the compensation effect, and the selected models were confirmed by the nonlinear model fitting method. The average activation energies obtained from the DSC results were 237.3, 293.8, and 231.3 kJ•mol−1 for the three consecutive steps of thermal decomposition of KClO3. The activation energies were 231.0 and 239.9 kJ•mol−1 for the first and second mass loss steps. The Avrami-Erofeev of Ax/y with the function of g(α) = [−ln(1−α)]x/y (x/y = 5/4 and 3/2) was the most probable model for describing the reaction steps.

Zwiazki utleniajace w srodkach kosmetycznych do wlosow oraz metoda ic identyfikacji i oznaczania

38%

Smietanka B. , Karlowski K.

Roczniki Państwowego Zakładu Higieny

2000

tom 51

nr 1

87-92

W pracy opisano zastosowanie związków utleniających w środkach kosmetycznych do włosów. Podano podstawy prawne uzasadniające konieczność oznaczania ich w wyrobach znajdujących się na rynku oraz opisano metodę identyfikacji i oznaczania związków utleniających i nadtlenku wodoru, przydatną dla potrzeb nadzoru sanitarnego.

Hydrogen peroxide and oxidazing agents are used in hair lightenning products, in oxidants of permanent wave products, hair dyeing products and toothpastes. In accordance with the Cosmetic Directive of the European Union (Council Directive of 27 July 1976 r. Annex III p. 12) maximum permitted concentration in the finished above mentioned cosmetic products is 12% in hair care preparations, 4% in skin-care preparations, 2% in nail hardening. The method identification and determination hydrogen peroxide and oxidazing agents is very useful for control cosmetic products on market.