Low specific speed centrifugal pumps have low flow rates and high heads. They are widely
applied in the petroleum, chemical, aerospace, pharmaceuticals, metallurgy, and light
industries, among others. With the development of space technology and petrol chemical
industry, the highly stable cavitation performance of centrifugal pumps has been put
forward. Poor cavitation performance is one of the key problems in low specific speed
An effective separation method of very pure binder fraction to assess radiocarbon dating is
proposed in the present contribution. The elimination of contaminant error sources and the
suitable selection of mortar samples enable the reliable dating. Petrographic analysis under
polarizing light microscopy is used to identify different mineralogical phases of mortar
samples, aggregate nature, and the limestone fragment remains.
All the necessary
information and data were collected from both medical records of the patients and special questionnaires that were designed by our staff in
1996 for this purpose. Statistical analysis was carried out descriptively by using frequency and percentage. Presence of TB in the patients
was confirmed by identifying the microorganism in the tissues detecting pathological changes in favour of TB and/or having past history of
pulmonary TB associated with its anatomical complications such as cavitation, bronchiectasis, and bronchial stenosis.
The Institutional Review Board approved this retrospective
study, with a waiver of informed consent from the patients. TB outbreaks
occurred in 15 senior high schools and chest radiographs from 58 students with
identical strains of TB were analyzed by restriction fragment length polymorphism
analysis by two independent observers. Lesions of nodule(s), consolidation, or
cavitation in the upper lung zones were classified as typical TB.