Optimisation of thermal processing — A review

The mathematical methods for optimising the effects of heat processing food products are reviewed in relation to microbial destruction, nutrient destruction, cooking value and loss of quality. Some data are presented for the kinetics of the various thermal effects. The results obtained by various workers are presented with particular reference to nutrient retention.     

Development of thermal fatigue damage in 1CrMoV rotor steel

Crack initiation endurances have been determined for a 1CrMoV rotor steel in uniaxial service cycle thermo-mechanical fatigue (TMF) tests formulated to simulate a range of steam turbine start cycles with a maximum temperature of 565 °C. The experimental details for these TMF tests are described.Post test inspection has been employed to characterise the associated thermal fatigue damage mechanisms for the steel which are observed to be dependent on the magnitude of the thermal transient in the TMF cycle.The lowest resistance to thermal fatigue damage development occurs in these tests when the conditions determine that the rate of creep damage accumulation below the surface exceeds the rate of fatigue crack development at the surface.     

Triacylglycerol synthesis in the oleaginous yeastCandida curvata D

Low rates of triacylglycerol (TAG) biosynthesis were observed in cell-free extracts ofCandida curvata, but rates were increased up to 10-fold by adding either α- or β-cyclodextrins. Spheroplasts, whole or gently disrupted, had higher rates of incorporation of both [U-¹⁴C]glycerol 3-phosphate or [1-¹⁴C]oleate into triacylglycerol and the intermediates of its biosynthesis: lysophosphatic acid, phosphatidic acid and diacylglycerol. Fatty acyl-CoA synthetase was highest with palmitate, oleate and linoleate but was some 6- to 8-fold lower with stearate. Stearate and stearoyl-CoA were poorly incorporated into lipids. Subcellular fractionation of the spheroplasts into mitochondrial, microsomal, lipid bodies and supernatant fractions diminished the rates of¹⁴C incorporation of oleate into triacylglycerol. By comparing the relative specific activities for each activity in each fraction, the fatty acyl-CoA synthetase activity appeared mainly in the lipid bodies, and that for phosphatidic acid formation was mainly in the mitochondrion; other activities were too weak and too dispersed for accurate assessment of their location. Recombining all the subcellular fractions restored triacylglycerol synthesizing activity. Omitting any single fraction from the mixture did not result in restoration of triacylglycerol synthesizing activity. Starvation of the yeast, which leads to utilization of the endogenous lipid reserves, stimulated fatty acyl-CoA synthetase activity, but diminished phosphatidic acid and triacylglycerol biosynthesis indicating probable induction of β-oxidation in the peroxisomes and repression of lipid biosynthesis.     

Multifractal signatures of infectious diseases

Incidence of infection time-series data for the childhood diseases measles, chicken pox, rubella and whooping cough are described in the language of multifractals. We explore the potential of using the wavelet transform maximum modulus (WTMM) method to characterize the multiscale structure of the observed time series and of simulated data generated by the stochastic susceptible-exposed-infectious-recovered (SEIR) epidemic model. The singularity spectra of the observed time series suggest that each disease is characterized by a unique multifractal signature, which distinguishes that particular disease from the others. The wavelet scaling functions confirm that the time series of measles, rubella and whooping cough are clearly multifractal, while chicken pox has a more monofractal structure in time. The stochastic SEIR epidemic model is unable to reproduce the qualitative singularity structure of the reported incidence data: it is too smooth and does not appear to have a multifractal singularity structure. The precise reasons for the failure of the SEIR epidemic model to reproduce the correct multiscale structure of the reported incidence data remain unclear.     

On combined equalization and decoding of multilevel codedmodulation

We describe an approach to combined equalization and decoding of multilevel block-coded modulation. This approach has better performance than conventional, concatenated equalization and decoding. The proposed structure uses a simple iterative scheme to decode and equalize multilevel block-coded modulation based on decision feedback. We show via computer simulation that the combined scheme gives a performance gain of up to 0.8 dB at a bit-error rate of 10^-4     

Acute upper limb ischemia resulting from cleidocranial dysostosis

A case is reported of a woman with an ischemic arm as a result of damage to the subclavian artery by the clavicular anomaly associated with cleidocranial dysostasis. Only one similar case has been reported previously.