The electrical behaviour of GaAs MESFETs formed on high and low temperature GaAs buffer layers

in High Performance Electron Devices for Microwave and Optoelectronic Applications (1997, November 24)

Comparisons have been made between the channel currents in GaAs hESFETs prepared on GaAs buffer layers prepared at normal and low temperatures. All devices made on LT buffer layers had saturated channel ... [more ▼]

Comparisons have been made between the channel currents in GaAs hESFETs prepared on GaAs buffer layers prepared at normal and low temperatures. All devices made on LT buffer layers had saturated channel currents which were about 20% of similar devices on a normal buffer. An attempt was made to remove Ga vacanciies from the LT buffer by a high temperature anneal step before the epitaxial layer was prepared. This had no effect in increasing the channel current. In all cases the pinchoiy voltage was unchanged indicating constancy of the channel thickness and donor concentration. It is concluded that the loss of current is due to a loss of mobile charge through trapping. [less ▲]

Qualitätsforderung für den Werterziehung im Primärschulunterricht

Article for general public (1997)

Specific activation related to proper name retrieval associated with faces

Poster (1997, October)

Educational Attainment as a Function of Delayed Acculturation

Scientific Conference (1997, August)

The pipecolate-incorporating enzyme for the biosynthesis of the immunosuppressant rapamycin: Nucleotide sequence analysis, disruption and heterologous expression of rapP from Streptomyces hygroscopicus.

in European Journal of Biochemistry (1997), 247(2), 526-534

An open reading frame (rapP) encoding the putative pipecolate-incorporating enzyme (PIE) has been identified in the gene cluster for the biosynthesis of rapamycin in Streptomyces hygroscopicus. Conserved ... [more ▼]

An open reading frame (rapP) encoding the putative pipecolate-incorporating enzyme (PIE) has been identified in the gene cluster for the biosynthesis of rapamycin in Streptomyces hygroscopicus. Conserved amino acid sequence motifs for ATP binding, ATP hydrolysis, adenylate formation, and 4'-phosphopantetheine attachment were identified by sequence comparison with authentic peptide synthetases. Disruption of rapP by phage insertion abolished rapamycin production in S. hygroscopicus, and the production of the antibiotic was specifically restored upon loss of the inserted phage by a second recombination event. rapP was expressed in both Escherichia coli and Streptomyces coelicolor, and recombinant PIE was purified to homogeneity from both hosts. Although low-level incorporation of [14C]beta-alanine into recombinant PIE isolated from E. coli was detected, formation of the covalent acylenzyme intermediate could only be shown with the PIE from S. coelicolor, suggesting that while the recombinant PIE from S. coelicolor was phosphopantetheinylated, only a minor proportion of the recombinant enzyme from E. coli was post-translationally modified. [less ▲]

Aggregation of ordinal data and open problems related to possibilistic approximation of monotonic set functions

Scientific Conference (1997, May 22)

On Sugeno integral as an aggregation function

Presentation (1997, April)

Bioéthique et culture démocratique

Book published by L'Harmattan (1997)

Characterization of some aggregation functions stable for positive linear transformations

Scientific Conference (1997, January)

Electrical Behaviour of the InP/InGaAs Based MSM-2DEG Diode

in Solid-State Electronics (1997), 41(1997), 25-31