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THE fact that the anti‐knock rating of aviation fuels in octane numbers presents difficulties, especially above 80 octane, has led us to develop a more suitable test method for aviation fuels, which might be called the “Allowable Boost Ratio ” method.

A decomposition method is implemented for solving travelling wave solutions of a fourth‐order semilinear diffusion equation.

THERE has recently been a marked tendency in aviation petrol specifications (particularly in the U.S.A.) to demand fuels of increasing volatility. The idea behind this is that the higher the volatility the better the distribution of the fuel and, therefore, the more uniform the mixture delivered to the various cylinders wjll be.

This paper aims to construct a sixth-order weighted essentially nonoscillatory scheme for simulating the nonlinear degenerate parabolic equations in a finite difference framework.

To design this scheme, we approximate the second derivative in these equations in a different way, which of course is still in a conservative form. In this way, unlike the common practice of reconstruction, the approximation of the derivatives of odd order is needed to develop the numerical flux.

The results obtained by the new scheme produce less error compared to the results of other schemes in the literature that are recently developed for the nonlinear degenerate parabolic equations while requiring less computational times.

This research develops a new weighted essentially nonoscillatory scheme for solving the nonlinear degenerate parabolic equations in multidimensional space. Besides, any selection of the constants (sum equals one is the only requirement for them), named the linear weights, will obtain the desired accuracy.

THE problem of undercarriage retraction has now been completely solved, and difficulties may occur only when the wheel has to be stowed flat under the wing as the motion generally requires a rotation about the centre line of the shock absorber.

THE original work of Mr. H. R. Ricardo in 1919 showed some of the technical advantages of using fuels of high anti‐knock value. Since this time the development of aero‐engines in respect of power output and economy has depended more upon the fuels available than upon any other factor. Considerable progress has been made in the direction of improving the anti‐knock value of petroleum spirits, which constitute the bulk of the fuel used in aviation throughout the world. However, until very recently this progress had not been very rapid, and as Mr. Ricardo showed, far greater improvements in anti‐knock value could be achieved by the use of other fuels such as benzol, toluol and alcohol. On the octane scale benzol and toluol have a blending value by the C.F.R. motor method of about 90 in concentrations up to 50 per cent; that of alcohol being about 105. This is shown in Fig. 1, from which it will be observed that two curves are given for ethyl alcohol, one being obtained under motor method conditions (mixture temperature 149 deg. C.) and the other with the same heat input as required for a normal aviation gasoline. By this means the additional advantage of the higher latent heat of the alcohol blends is shown. Neither benzol, toluol nor alcohol is produced in very large quantities, and moreover, in times of national emergency they are likely to be required for purposes other than for use as aviation fuels.

This paper aims to analyze the steady two-dimensional stagnation-point flow of an electrically conducting Newtonian or micropolar fluid when the obstacle is uniformly heated.

The governing boundary layer equations are transformed into a system of ordinary differential equations using appropriate similarity transformations. Some analytical considerations about existence and uniqueness of the solution are obtained. The system is then solved numerically using the bvp4c function in MATLAB.

If the temperature of the obstacle T_w coincides with the environment temperature T₀, then the motion reduces to the usual orthogonal stagnation-point flow; if T_w = T₀, then it is necessary to include in the similarity function describing the velocity an oblique part due to the temperature. Also, the presence of a uniform external magnetic field orthogonal to the obstacle is examined. In all cases, the motion is reduced to a system of nonlinear ordinary differential equations with boundary conditions, whose solution is discussed numerically when the Prandtl and the Hartmann number varies.

The present results are original and new for the problem of magnetohydrodynamic mixed convection in the plane stagnation-point flow of a Newtonian or a micropolar fluid over a vertical flat plate. At infinity, the motion approaches the orthogonal stagnation-point flow of an inviscid fluid; the effect of an uniform external magnetic field is considered, and the obstacle has a uniform temperature.

The initial value problem for a semi-linear high-order heat equation is investigated. In the focusing case, global well-posedness and exponential decay are obtained. In the focusing sign, global and non global existence of solutions are discussed via the potential well method.

This chapter interrogates gender, inner conflict and narrative arcs of the characters of Daryl Dixon and Carol Peletier in the TV series The Walking Dead.

From the outset, these two characters are constructed in line with traditional gendered stereotypes, yet they both go through a transformation during the series, moving away from their starting point. Carol and Daryl are introduced to the audiences in scenes that situate them within traditional gendered roles and spaces. Thus, Carol is presented as submissive, compliant and obedient; she speaks with a soft voice and is positioned within domestic spaces in the camp site: by the camp fire, by the washing spot in the lake, inside the tent, etc. In contrast, Daryl is presented as a loner and a hunter, is referred to as a volatile person and portrays a physical appearance that echoes redneck masculinities (O’Sullivan, 2016).

This chapter will engage with theories of performativity and gender in relation to character design, in order to analyse and compare the ways in which these two characters challenge the gender stereotype through actions, yet often conform to it through the inner conflict and the solutions adopted.

An explanation is given of the physical factors which govern the influence of the speed of sound on the drag, of an aeroplane, and on its performance. Observing the processes at the point of stagnation, the criterion for the compressibility influence is the Machs number, the introduction of which is also explained.