Species identification of cooked meats by enzyme-staining of isoelectricfocusing gels

By extracting cooked meat products with 6 m guanidine hydrochloride and then dialysing the extract into 1 % Triton X-100, the activity of adenylate kinase (AK) and creatine kinase (CK) may be at least partly recovered, provided the meat was not heated above ≈120°C (AK) or ≈105°C (CK). A wide range of animal species may be identified in cooked meats by staining isoelectricfocusing gels for these two enzymes. However, if a sample consists of mixed flesh from different species, hybrid creatine kinase dimers form during dialysis and the additional bands complicate interpretation of gel patterns.     

Calculation of the wetted area of a planing hull with a chine

Summary The extent to which a low-aspect-ratio flat ship with a chined hull is wetted when planing at infinite Froude number is investigated. A numerical method of solution for the wetted area, which is applicable to more general planing problems, is presented. The results obtained by this method are compared with those found by solving the inverse problem of determining the hull shape which produces a given waterplane shape and are shown to be in excellent agreement. Results are also presented which indicate that a vertical chine may be used to fix the shape of the wetted region.     

The rate of movement of the topochemical interface during gas-solid reactions

The rate of recession of the topochemical interface between a porous core and the product layer is shown to be given by wherer _c is radial position of the interface,R(r_c) the rate of the chemical reaction at the interface and (dC _s/dr)|_{r s} is the gradient of concentration profile of solid reactant in the porous core at the interface. The integration of the above equation can sometimes be achieved analytically but can always be done numerically for even highly complex reaction mechanisms. The equation correctly reduces to previously known solutions when the inner core is impervious to gas diffusion. The utility of the equation is demonstrated by applying it to the industrially important multistage reduction process Mn₃O₄ → MnO — > Mn. The predictions from the theoretical model are compared successfully with experimental data for this reaction. Formerly Student in Department of Metallurgy, University of Strathclyde, Scotland.     

Craze intersections in biaxially-stressed polystyrene

Crazes are produced on two orthogonal planes in both thin film and macroscopic samples of polystyrene by sequentially applying two orthogonal tensile strains ₁ and ₂. Although many crazes produced by the second strain ₂ (secondary crazes) are stopped when they meet a primary craze, some intersections occur. The fraction of craze meetings resulting in intersection increases from 20% at ₁= ₂=3% to 55% at ₁= ₂=5%; intersections also occur preferentially in thin regions of primary crazes. The craze fibril structure in the intersection has a much lower fibril volume fraction, v _f, than either of the two crazes from which it formed. The fibril volume fraction in the intersection is approximately given by the product of the fibril volume fractions of the two crazes, in agreement with a prediction based on the surface drawing mechanism of craze thickening. At higher strain levels the v _fs of the intersections are lower, leading to higher fibril stresses and enhanced fibril fracture; an increasing fraction of intersections breaks down to form large voids at these higher strain levels. Fractography of macroscopic samples containing intersecting crazes demonstrates that voids formed at the intersections can act as nuclei for cracks causing premature fracture of the material.     

Comparison of two suspension control strategies for multi-axle heavy truck

Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototype (FVP) model and compared in terms of road friendliness and ride comfort. A four-axle heavy truck-road coupling system model was established using FVP technology and validated through a ride comfort test. Then appropriate passive air suspensions were chosen to replace the rear tandem suspensions of the original truck model for preliminary optimization. The mechanical properties and time lag of dampers were taken into account in simulations of MSD and PID semi-active dampers implemented using MATLAB/Simulink. Through co-simulations with Adams and MATLAB, the effects of semi-active MSD and PID control were analyzed and compared, and control parameters which afforded the best comprehensive performance for each control strategy were chosen. Simulation results indicate that compared with the passive air suspension truck, semi-active MSD control improves both ride comfort and road-friendliness markedly, with optimization ratios of RMS vertical acceleration and RMS tyre force ranging from 10.1% to 44.8%. However, semi-active PID control only reduces vertical vibration of the driver’s seat by 11.1%, 11.1% and 10.9% on A, B and C level roads respectively. Both strategies are robust to the variation of road level.     

Heat-induced tenderisation of meat by endogenous carboxyl proteases

The rôle of carboxyl proteases in tenderising meat was investigated by injecting the inhibitors, pepstatin and EPNP, into pre-rigor muscle. The increase in shear force values induced by these inhibitors provided a minimum estimate of the extent to which endogenous carboxyl proteases normally tenderise meat at 60°C.Gel electrophoresis showed that connectin was hydrolysed to a greater extent than other muscle proteins at this temperature and that breakdown of connectin was inhibited by pepstatin and EPNP. Thus it is likely that, when intact, connectin may contribute to the strength of cooked meat.     

A 1.2-V 0.25-/spl mu/m clock output pixel architecture with wide dynamic range and self-offset cancellation

A 10T/pixel CMOS digital pixel sensor with clock count output, ultra low supply voltage, and wide dynamic range is presented. The pixel fabricated by a standard 0.25-/spl mu/m CMOS logic process comprises a reset transistor, a photo-diode, a comparator, and an inverter with pixel size of 9.4/spl times/9.4 /spl mu/m/sup 2/ and 24% fill factor. The amplified logarithmic output response similar to the light response of human eye is demonstrated in this work. The pixel can operate at a supply voltage as low as 1.2 V without affecting its output characteristics. The dynamic range of this cell limited by either the subsequent analog-to-digital circuit resolution or the rising and falling time of output clock is higher than 90 dB with an 8-bit resolution.