ISSN:0021-8871    

DOI:10.1002/jctb.5010141009

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe gas‐handling capacity and influence on mass transfer of turbine impellers have been investigated in baffled 5–1, vessels, mainly in a three‐phase mixture containing a high proportion of fibrous solids. The ability of the impellers to disperse the gas was strongly dependent on the speed of rotation and to a smaller extent on blade size. In the non‐Newtonian systems investigated, the correlation of mass transfer and ‘impeller factor’ showed two regions which were characterised by different constants of proportionality. Within each region, mass transfer was directly related to the impeller factor, regardless of the impeller design. The range of power inputs of importance in many industrial fermentation processes lies in the region characterised by the lower constant of proportionality. It is suggested that bubble coalescence is the dominant factor limiting impeller performance in this region.When the baffles were not in contact with the walls of the vessels, partially‐baffled conditions were produced in Newtonian systems of low viscosity. This resulted in a reduction of the power required for a given rate of mass transfer. This advantage was less marked in non‐Ne

ISSN:0021-8871    

DOI:10.1002/jctb.5010141001

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractA wide range of types and grades of roofing bitumen have been subjected to bulk heating, pressure oxidation, solar exposure and water immersion separately, and the resulting changes in rheological properties determined.Particular attention was given to the use of a sliding plate microviscometer and the means of overcoming complexities of non‐Newtonian behaviour and shear rupture to develop evaluations, oxidation resistance and solar exposure resistance, involving initial viscosity, rate of increase of viscosity and a critical viscosity at rupture. Results of these tests are discussed in relation to the performance of the bitumens when exposed outdoors for 2 years as model roofs with various surfacings and evaluated by visual rating, microviscometry, and solvent analysis. Agreement is good and the advantage in durability by using as low a softening point bitumen as possible is indicated except for aluminium‐painted coati

ISSN:0021-8871    

DOI:10.1002/jctb.5010141002

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractMoist esparto grass self‐heats less easily than hay, but, as in the latter case, microbiological heating is most likely to lead to further chemical heating at a relative humidity of approximately 96%. Esparto grass has a considerably smaller moisture content than hay when in equilibrium with this R.H. and these results therefore confirm the importance of R.H. in initiating spontaneous combustio

ISSN:0021-8871    

DOI:10.1002/jctb.5010141003

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractA study has been made of the promotion of dropwise condensation on chromium surfaces by monolayers of stearic acid‐1‐14C, montanic acid‐19,20‐T(n), and mixed monolayers of stearic acid and octadecane. The desorption of promoter during condensation was followed by carbon‐14 and tritium counting and by autoradiography. The accompanying increase in wettability was characterised by changes in heat transfer. The life of promotion ranged from 50 to 200 min., increasing in the series: mixed monolayer

ISSN:0021-8871    

DOI:10.1002/jctb.5010141004

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe authors have further developed a method, using radioactive sulphur dioxide for examining the effect of variables such as humidity, temperature and furnish on the affinity of sulphur dioxide for paper.The temperature coefficient indicates that a diffusion process determines the rate of uptake which is also almost linearly related to moisture content, being increased by storage under moist conditions.

ISSN:0021-8871    

DOI:10.1002/jctb.5010141005

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe preparation of ethylene glycol dioleate is described, and its union with gaseous oxygen at 55, 85 and 120° has been investigated. The reactivity of the ester with oxygen is compared with previously published data for the monoesters and for ethylene glycol dielaidate

ISSN:0021-8871    

DOI:10.1002/jctb.5010141006

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe extraction of molybdenum from aqueous nitric acid containing various fission products has been examined. A separation of molybdenum and of zirconium and niobium from the long‐lived fission products90Sr,99Tc,106Ru,137Cs,144Ce and147Pm is possible with alkyl phosphoric acids. Separation of molybdenum from zirconium and niobium can be achieved by back‐extraction into an aqueous mixture of ammonium fluoride and nitric a

ISSN:0021-8871    

DOI:10.1002/jctb.5010141007

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractClay minerals such as kaolinite, illite, nontronite and montmorillonite were complexed with methylene blue, Malachite green and piperidine and their behaviour when heated was followed by differential thermal and thermogravimetric analysis. The results indicated that organic cations adsorbed on the broken bonds being easily accessible to oxygen are oxidised exothermally between 150 and 500°. The cations adsorbed in the interlayer are oxidised in the range 500 to 800° and this corresponds to the temperature at which the (OH) water is expelled from the clay mineral

ISSN:0021-8871    

DOI:10.1002/jctb.5010141008

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY