ISSN:0268-2575    

DOI:10.1002/jctb.280361002

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractIncreasing ammonium‐nitrogen concentrations caused failure of methanogenesis at 1900‐2000 mg dm−3. After an adaptation period characterised by an almost nil methane production, methanogenesis appeared to be possible at even higher concentrations. A kinetic analysis of methane production during the adaptation process indicated that the adaptation was the result of a metabolic change in the methanogenic bacteria already present, rather than of growth of new bacteria. A high pH value causing toxic concentrations of un‐ionised ammonia during the adaptation period appeared to result in a decreased maximum specific methanogenic activity of the adapted sludge. A low pH value during the adaptation period resulted in a retarded degradation of propionic acid, probably due to inhibition of the hydrogen consuming methanogenic bacteria by undissociated volatile fatty acids, but this did not result in a decreased maximum specific methanogenic activity in the adapted sludge. The maximum specific methanogenic activity at an ammonium‐nitrogen concentration of 2315 mg dm−3after adaptation as a percentage of that at 1000 mg dm−3before adaptation was 31, 65 and 61% for a pH during the adaptation period of 7.6, 7.25 and 7.0 respectively. Except for the sludge which was maintained at pH 7.6 during the adaptation period, after adaptation the maximum specific methanogenic activity at an ammonium‐nitrogen concentration of 2315 mg dm−3was higher than the maximum specific methanogenic activity at an ammonium nitrogen concentration of 1900 mg dm

ISSN:0268-2575    

DOI:10.1002/jctb.280361003

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe liquid phase oxidation of acetophenone to phenylglyoxal using selenium dioxide was carried out at 90°C in dioxane or ethyl alcohol with 10% (v/v) of water as a solvent with a 2:1 molar ratio of acetophenone to selenium dioxide. The yield of phenylglyoxal was more than 98% based on acetophenone and the efficiency of utilisation of selenium dioxide was as high as 99%. A novel process version based on the oxidation of acetophenone by aqueous nitric acid in the presence of selenium dioxide as a selective catalyst in a redox cycle was also considered with a view to changing the use of selenium dioxide as a stoichiometric oxidising agent to that of a catalyst, and it was found to be attractive

ISSN:0268-2575    

DOI:10.1002/jctb.280361004

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractPrecipitation is the principal technique used by the blood plasma fractionation industry for the separation and concentration of human proteins for clinical use. Although precipitation has many attractions it is particularly difficult to control and the resultant overshoot of key parameters is responsible for loss of product yield and sometimes quality. Much of this problem is due to the inefficiency of mixing and heat transfer in large bulk volumes of protein solution; hence control is limited by the process design. Therefore we have applied the concept of continuous‐flow processing to scale‐down process volumes, to improve the efficiency of mixing and heat transfer and to allow the opportunity for in‐line monitoring and control of important parameters. Ten years experience with a routine manufacturing process of this type has illustrated the benefits of this approach and has led to the modernisation of the process with replacement of centralised computer control by a microprocessor‐based

ISSN:0268-2575    

DOI:10.1002/jctb.280361005

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractLaser‐light scattering measurements can be used for investigations of solid dissolution in a liquid. In this paper the dissolution of gypsum in water is followed by scattering and conductance measurements. Both types of measurement are carried out simultaneously. The sensitivity of the scattering technique and its special applicability in solubility determinations is discusse

ISSN:0268-2575    

DOI:10.1002/jctb.280361006

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractNew asymmetrical 2‐monomethine cyanine dyes (IIIa—d,IVa—c) and dicationic cyanines(VIIa,b) incorporating oxazolo/imidazolo(3,4‐d)pyrimidine were prepared. The new cyanines were identified by spectral determination. The applications of these dyes in the protometric titrations of acids and bases were investigated. Bactericidal and fungicidal activity of selected cyanines (Ia,IIa, b,IIIb,IVb, c,V,VIandVIIb) was

ISSN:0268-2575    

DOI:10.1002/jctb.280361007

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe isomerization of glucose into fructose using a commercial immobilised glucose‐isomerase has been studied and an initial transitory state of the enzyme, probably due to an establishment of stationary concentration profiles, was observed. Operational conditions to minimise the effects of external and internal mass transfer were determined using immobilised enzyme particles with diameters less than 0.064 mm. Thermal enzyme deactivation of the enzyme was insignificant if it was pre‐treated with cobalt. The intrinsic kinetic constants of the reversible reaction Michaelis—Menten equation were calculated, in operational conditions free of mass transfer ef

ISSN:0268-2575    

DOI:10.1002/jctb.280361008

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe performance of a low cost differential enzyme thermistor system was studied. Initial results from physical characterisations showed the interdependence of operating parameters (flow rate and ambient temperature) on detector sensitivity. Subsequent work demonstrated the detection of urea using an immobilised urease column.

ISSN:0268-2575    

DOI:10.1002/jctb.280361009

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

ISSN:0268-2575    

DOI:10.1002/jctb.280361001

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY