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Biomedical subjects

S Thiagarajan

Publications and source records attributed to S Thiagarajan.

5 recordsLinked to original sources
PubMed2005

Improvement of xylanase production in solid-state fermentation by alkali tolerant Aspergillus versicolor MKU3.

AIMS: To optimize the media components for xylanase production by Aspergillus versicolor MKU3 in solid-state fermentation (SSF). METHODS AND RESULTS: Medium optimization was carried out using De Moe's fractional factorial design with seven components. Maximum production of xylanase 3249.9 U g(-1) was obtained in SSF with an optimized medium containing (g l(-1)): NaNO(3), 20; K(2)HPO(4), 20; MgSO(4), 10; FeSO(4), 0.001; KCl, 1; peptone, 10 and yeast extract, 10. Four components namely NaNO(3), MgSO(4), peptone and K(2)HPO(4) significantly increased the xylanase production by A. versicolor MKU3. CONCLUSIONS: Fractional factorial design was used to optimize the seven components in the fermentation medium for SSF. The optimized media increased xylanase production by 3.4-fold. SIGNIFICANCE AND IMPACT OF THE STUDY: Aspergillus versicolor MKU3 produced maximum xylanase after two steps of media optimization under alkaline condition. This medium will be significant value for xylanase production in SSF.

Alkalies↗
PubMed2005

Improvement of xylanase production in solid state fermentation by alkali-tolerant Aspergillus fumigatus MKU1 using a fractional factorial design.

Optimization of media for the maximum production of xylanase by Aspergillus fumigatus MKUI was carried out using De Meo's fractional factorial design with seven components such as NaNO3, K2HPO4, MgSO4, FeSO4. KCl, peptone and yeast extract. A. fumigatus produced a maximum of 700 U/gds of enzyme after 48 hr of incubation (before optimization). After two steps of optimization, the medium designed favoured a 2.8 fold (1950 U/gds) increase in xylanase production by A. fumigatus. Optimized medium for Aspergillus fumigatus contained (g/l) NaNO3, 15; K2HPO4, 15; MgSO4, 5; FeSO4, 0.009; KCI, 0.5; peptone, 20; and yeast extract, 10.

Aspergillus fumigatus↗
PubMed1991

Design of 20 MHz wideband piezoelectric transducers for close proximity imaging.

Quarter wave matching of ultrasonic transducers with two layers (glass and parylene) were studied with computer simulation. These layers are located between the piezoelectric transducer and the acoustic load. The purpose is to achieve a short impulse response and high efficiency broadband transfer in a practical manner for high frequency transducers. The acoustic impedances of these layers were chosen based on transmission line theory. A method to measure acoustic properties of the matching layers and a method to choose the material are discussed. The advantages in using a quarter wavelength of glass and parylene as the matching layers are given. The 6 dB fractional bandwidth of the simulated transmission-reception transfer was found to be 0.75, which is a factor of at least 6 improvement over a nonmatched transducer.

Computer Simulation↗
PubMed1977

Evaluation of simulations and games: a comprehensive procedure and a case history.

This article deals with the dimensions of evaluating simulations and games in health education, provides a procedural model which incorporates these dimensions, and illustrates this model with a case history of the evolution of a game through repeated evaluation. The four major dimensions of evaluating a game are the purposes of evaluation, sources of evaluative data, emphasis on main or side effects, and timing of evaluation. The procedural model incorporates these dimensions of evaluation and is divided into stages of self-evaluation, expert appraisal, informal player tryouts, typical-use testing, field testing, and long-term evaluation. The case history illustrates the application of each of these stages to a short game in consumer health education.

Evaluation Studies as Topic↗