World view theory and the conceptualisation of space in mathematics education:
- Authors: Schäfer, Marc
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141052 , vital:37940 , DOI: 10.4102/pythagoras.v0i59.127
- Description: The cornerstone of current education trends that recognise prior knowledge as fundamental to the learning process, is the notion that beliefs and experiences that learners bring to the classroom influence their learning experiences in the classroom (Cobern, Gibson and Underwood, 1999).
- Full Text:
- Date Issued: 2004
- Authors: Schäfer, Marc
- Date: 2004
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141052 , vital:37940 , DOI: 10.4102/pythagoras.v0i59.127
- Description: The cornerstone of current education trends that recognise prior knowledge as fundamental to the learning process, is the notion that beliefs and experiences that learners bring to the classroom influence their learning experiences in the classroom (Cobern, Gibson and Underwood, 1999).
- Full Text:
- Date Issued: 2004
Zinc phthalocyanine photocatalyzed oxidation of cyclohexene
- Sehlotho, Nthapo, Nyokong, Tebello
- Authors: Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289399 , vital:56629 , xlink:href="https://doi.org/10.1016/j.molcata.2004.05.010"
- Description: Cyclohexene photooxidation catalyzed by zinc phthalocyanine (ZnPc) using either red or white light results in the formation of cyclohexenone, cyclohexenol, trans-cyclohexanediol, cyclohexene oxide and cyclohexene hydroperoxide. The product yield increased as follows: cyclohexenone > cyclohexenol > trans-cyclohexanediol > cyclohexene oxide > cyclohexene hydroperoxide. The mechanism for the formation of these products involves both singlet oxygen and radicals (Type II and Type I mechanisms, respectively). The catalyst degraded slowly when low light intensities were employed. The product yields were found to depend on the light intensity, the nature of solvent, irradiation time and the rate of photodegradation of the catalyst.
- Full Text:
- Date Issued: 2004
- Authors: Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2004
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289399 , vital:56629 , xlink:href="https://doi.org/10.1016/j.molcata.2004.05.010"
- Description: Cyclohexene photooxidation catalyzed by zinc phthalocyanine (ZnPc) using either red or white light results in the formation of cyclohexenone, cyclohexenol, trans-cyclohexanediol, cyclohexene oxide and cyclohexene hydroperoxide. The product yield increased as follows: cyclohexenone > cyclohexenol > trans-cyclohexanediol > cyclohexene oxide > cyclohexene hydroperoxide. The mechanism for the formation of these products involves both singlet oxygen and radicals (Type II and Type I mechanisms, respectively). The catalyst degraded slowly when low light intensities were employed. The product yields were found to depend on the light intensity, the nature of solvent, irradiation time and the rate of photodegradation of the catalyst.
- Full Text:
- Date Issued: 2004