摘要:

AbstractThe phases formed in a high‐slag cement on curing in saturated steam at 180 lbf/in2, have been investigated. X‐ray diffraction revealed that in the presence of suitable addition of fine quartz, 11‐Å tobermorite was the predominant phase formed in an autoclaving period of 5 h at maximum pressure; the phases identified in neat slag cement were 11‐Å tobermorite and hillebrandite. The same phases were identified in the samples autoclaved for 6 h, in addition to minor amount of xonotlite. Chemical analysis of the same hydrated samples has shown that the molar CaO/SiO2ratio was 1.27 for the cement‐quartz and 1.49 for the neat cement for the 5‐h autoclaving period, and 1.35 and 1.57, respectively, for t

ISSN:0375-9210    

DOI:10.1002/jctb.5020230702

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe strength of dense high‐slag cement‐sand mixes autoclaved at 180 lbf/in2, and of certain aerated mixes autoclaved at pressures ranging from 120 to 210 lbf/in2, has been determined. It was found that maximum strengths were developed in an autoclaving period of 5 h at 180 lbf/in2, and that longer periods, as well as higher autoclaving pressures, yielded lower strengths. The maximum strength values obtained for compacted 1: 3 (w/w) mixes were 425 kg/cm2in the absence of fine quartz, and 510 kg/cm2in the presence of suitable addition of fine quartz. The corresponding values for Portland cement mixes were, respectively, 330 and 460 kg/cm2for a heating period of 5 h, and 360 and 505 kg/cm2for a period of

ISSN:0375-9210    

DOI:10.1002/jctb.5020230703

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractPlaster of Paris has been recommended as a suitable bone substitute material. In this project both calcined and autoclaved plasters have been prepared and the effects of sterilisation on their properties determined. Samples of plaster suitable for use in animal experimentation have been prepared.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230704

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstract5‐Cyclohexadecenone is prepared from cyclododecanone via four new steps: chlorination, Grignard reaction with vinylmagnesium chloride and rearrangement with aluminium isopropoxide, revinylation with vinylmagnesium chloride and oxy‐Cope rearrangem

ISSN:0375-9210    

DOI:10.1002/jctb.5020230705

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractBagasse was pulped by the prehydrolysis‐soda process. Increasing the concentration during prehydrolysis or pulping had a favourable effect on pulp properties. Further improvement in these properties was attained when the increase in concentration was accompanied by lowering the temperature. The effects of increasing the concentration and lowering the temperature of prehydrolysis and pulping were compare

ISSN:0375-9210    

DOI:10.1002/jctb.5020230706

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe whole corn plant was successfully used for the production of pulp and paper by employing comparatively simple procedures of atmospheric pressure digestion followed by multi‐stage bleaching. Water pre‐treatment was found necessary to remove the dust particles. However, the use of boiling water was not recommended. The effects of the amount of active chlorine in the hypochlorite step on the optical and the physical‐strength properties of paper were investigated. One‐and two‐stage pulping were compared and the effect of depithing after the first stage wa

ISSN:0375-9210    

DOI:10.1002/jctb.5020230707

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractMethods are described for both the laboratory and plant scale preparations of hydroxylapatite to give 200 ml and 22 litre settled bed volumes respectively. These materials have an average particle size of 75 μm, give flow rates of up to 45 ml cm−2h−1and bind up to 50 mg protein/ml hydroxylapatite at pH 6.8. Examples of protein separations and purifications on hydroxylapatite are given and the nature and basis of hydroxylapatite chromatography is discu

ISSN:0375-9210    

DOI:10.1002/jctb.5020230708

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractMathematical models are developed for the transient behaviour of encapsulated enzyme reactor systems such as the continuous stirred tank reactor (CSTR) and the packed bed tubular reactor. The rate processes taking place in the encapsulated enzyme bed are approximated by using a combined rate control model of enzyme reaction and membrane diffusion. The change in transient substrate concentration is obtained by using the developed rate expression in the material balance over the substrate as a function of time for the CSTR and as a function of time and position for the packed bed tubular reactor. The effects of various parameters such as the enzymic reaction rate constant, Michaelis constant, diffusional resistance of membranes, and Peclet number on the substrate concentration distribution, which varies with respect to operating time, are investigated. This study affords insight into the transient operating characteristics of the encapsulated enzyme reactor system. The results should be useful in understanding the start‐up performance of the reactor systems and to control such reactor systems at desired operating condition

ISSN:0375-9210    

DOI:10.1002/jctb.5020230709

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA special apparatus was used to establish methane‐ and oxygen‐limited chemostat cultures of a methane‐utilising bacterium, at 30 °C, pH = 7.0, respectively. Although total growth yields with respect to methane and oxygen were hardly affected by dissolved oxygen concentration in the medium, provided dilution rate was kept nearly at 0.1 h−1, these values appeared to increase slightly with the increase of dilution rate. Assuming that no metabolites other than carbon dioxide and water were produced during bacterial growth, maintenance coefficients and true growth yields were assessed from specific rates of methane uptake and respiration. These energetic constants, nearly independent of the limiting substrates, either methane or oxygen, were compared with those from published data on facultative and obligate aerobes, including a mixed culture of methane‐utilisin

ISSN:0375-9210    

DOI:10.1002/jctb.5020230710

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.5020230701

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY