Standardization of the Methylene Blue Reduction Test by the Use of Methylene Blue Thiocyanate.
SINCE the first use of methylene blue reduction as an indicator of bacteriological quality in milk, fluid milk supplies on this continent have undergone notable improvement. Moreover, during this period it has been shown that the inaccuracies in the test increase with increasing reduction times.6' 8, 9 An effort to minimize these inaccuracies is, therefore, worth while. Because of the extensive use of this test in milk control activities, it becomes necessary to duplicate frequently the standard tablets of methylene blue certified by the Commission on Standardization of Biological Stains and recognized by the American Public Health Association in Standard Methods of Milk Analysis.' This duplication involves not only the creation of standards but also the purification or, at least, the determination of purity of the dye. Clark, Cohen, and Gibbs 2 review the difficulty, if not the impossibility, either of purification or of determination of purity of methylene blue chloride, the methylene blue salt used in these tablets.
Performance Analysis of the Milk Pasteurization Process Using a Flat Plate Solar Collector
A large share of Ethiopia’s milk production comes from its rural areas. However, this milk does not undergo further processing into dairy products on a large scale due to lack of conventional energy sources such as electricity and gas. Hence, the country is not utilizing its milk resources to the maximum possible. In this study, the possible use of solar energy for the milk pasteurization process is investigated by using a flat plate solar collector (FPSC) with and without reflectors integrated. Reflectors added to the FPSC have augmented the incident solar radiation on the collector from 0.27–0.91 kW/m2 to 0.36–1.18 kW/m2. The thermal efficiency obtained for the FPSC with reflectors integrated is 51.8% whereas that of the collector without reflectors integrated is 46.2%. Likewise, the exergy efficiency is found to be 5.43% for the collector integrated with reflectors and 2.53% for the collector without reflectors. Also, an increase in the daily processed milk production of 18% is observed in September and 16% in November by using the solar collector with reflectors integrated. The quality of pasteurized milk is checked by using the methylene blue reduction test (MBRT) method, and it indicates a better quality of pasteurized milk when compared with raw milk. Therefore, this study shows that the use of solar energy for milk pasteurization has great potential to increase the shelf life of milk, and it can be used as an instrument to improve the quality of life of people living in rural areas.
The Contemporary British History Play
Introduction Biographical History Plays Social History Plays Oppositional History Plays Marxist and Socialist History Plays Feminist History Plays Deconstructionist and Postmodern History Plays and Satire The Search for a Theatrical Form Appendix A: Performance Dates of Contemporary British History Plays Appendix B: Performance Locales of Contemporary British History Plays Bibliography Index