123 research outputs found
The construction and validation of an institutional work based learning programme.
This chapter explores why the Middlesex University approved the programme
Insulation bonding test system
A method and a system for testing the bonding of foam insulation attached to metal is described. The system involves the use of an impacter which has a calibrated load cell mounted on a plunger and a hammer head mounted on the end of the plunger. When the impacter strikes the insulation at a point to be tested, the load cell measures the force of the impact and the precise time interval during which the hammer head is in contact with the insulation. This information is transmitted as an electrical signal to a load cell amplifier where the signal is conditioned and then transmitted to a fast Fourier transform (FFT) analyzer. The FFT analyzer produces energy spectral density curves which are displayed on a video screen. The termination frequency of the energy spectral density curve may be compared with a predetermined empirical scale to determine whether a igh quality bond, good bond, or debond is present at the point of impact
Accurate quantification of nucleic acids using hypochromicity measurements in conjunction with UV spectrophotometry
UV absorbance spectrophotometry is widely used for the quantification of nucleic acids. For accurate quantification it is important to determine the hypochromocity of the oligonucleotide or complex nucleic acid structure. The use of thermal denaturation studies in conjunction with UV spectrophotometry to determine hypochromicity requires prolonged, elevated temperatures, which may cause partial hydrolysis of RNA. In addition, dsRNA is difficult to denature even at elevated temperature and the extinction coefficients of nucleic acids are also affected by temperature, which makes it difficult to accurately determine the nucleic acid concentration. To overcome these caveats, we have utilised the chemical denaturant dimethyl sulfoxide which, in conjunction with a short thermal denaturation prevents renaturation of the duplex nucleic acids (dsDNA/RNA). Using this approach, we have measured the absorbance of both the unstructured and structured nucleic acids to accurately measure their hypochromicity and determine their extinction coefficients. For a range of different dsRNA we have for the first time determined values of 46.18-47.29 µg/ml/A260 for the quantification of dsRNA using UV spectrophotometry. Moreover, this approach enables the accurate determination of the relative proportion of duplex nucleic acids in mixed ds/ss nucleic acid solutions, demonstrating significant advantages over current methods
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