The Transmission Loss of different kind of layered structures is investigated by means of a four microphone technique in a plane wave tube. By using the decomposition technique, incident, reflected and transmitted contributions are separated and transmission coefficient is easily calculated. In this paper a single measurement approach based on transfer matrix, taking into account reflection contri

The atmospheric profile whose sound speed varies linearly with height is simple in concept, but leads to complications when solving for the sound pressure. Its effects are commonly approximated by a similar profile whose squared refractive index is a linear function of height. In this paper, the validity of the approximation has been examined for sound propagation above an impedance ground and a c

We introduce a robust and efficient methodology to solve the Ornstein-Zernike integral equation using the pseudoarc length (PAL) continuation method that reformulates the integral equation in an equivalent but nonstandard form. This enables the computation of solutions in regions where the compressibility experiences large changes or where the existence of multiple solutions and so-called branch p

We consider a class of degenerate diffusion equations where the nonlinearity is assumed to be singular (non-Lipschitz) at zero. It is shown that solutions with compactly supported initial data become identically zero in finite time. Such extinction follows by comparison with newly constructed finite travelling waves connecting two stable equilibria.

We consider a class of differential-algebraic equations (DAEs) defined by analytic nonlinearities and study its singular solutions. The main assumption used is that the linearization of the DAE represents a Kronecker index-2 matrix pencil and that the constraint manifold has a quadratic fold along its singularity. From these assumptions we obtain a normal form for the DAE where the presence of the

A spectral element method is described which enables reduced wave equation problems defined in regular, arbitrary length regions to be solved as a set of coupled problems over neighbouring domains. A combination of trial functions are considered, namely the specific eigenfunctions of a differential operator and a set of hierarchical polynomials. Accurate approximations are obtained for computation

The transmission of vibrations over the surface of the ground, due to high-speed moving, vertical harmonic rectangular loads, is investigated theoretically. The problem is three-dimensional and the interior of the ground is modelled as an elastic half-space or a multilayered ground. The transformed solutions are obtained using the Fourier transform on the space variable. A new damping model in the

The transmission of vibrations over the surface of the ground, due to a high-speed moving, vertical harmonic strip load, is investigated theoretically. Consequently, the problem is essentially two-dimensional and the interior of the ground is modelled as an elastic half-space. The transformed solutions are obtained using the Fourier transform on the space variable. A study of a new damping model i

A boundary integral equation is described for the prediction of acoustic propagation from a monofrequency coherent line source in a cutting with impedance boundary conditions onto surrounding flat impedance ground. The problem is stated as a boundary value problem for the Helmholtz equation and is subsequently reformulated as a system of boundary integral equations via Green's theorem. It is shown

The transmission of vibrations, and its reduction, in the far-field of the surface of the ground due to a harmonic load acting over a strip, is investigated theoretically. A possible vibration attenuation device that has shown some promise is the "wave impedance block" (WIB). The principle of this is to modify the modal wave propagation regime of the ground by introducing an artificial stiffened l

The transmission of vibrations over the surface of the ground, due to a moving, vertical harmonic rectangular load, is investigated theoretically. The interior of the ground is modelled as an elastic half-space. The transformed solutions are obtained using the double Fourier transform. Numerical results for the displacements on the surface are presented for loads moving with speeds up to the Rayle

What does a postcolonial ethics of care mean for feminist geographers doing archival work? Feminist geographers have long called for ethical research engagement. This asserts the importance of caring relationships with research mentees, collaborators, participants, and spaces. But care comes both with promise and pitfalls. As postcolonial and antiracist geographers argue, we must emplace care. Tha

This book delineates the scope of permissible compulsory mental health interventions under the Convention on the Rights of Persons with Disabilities (CRPD).The initial impetus for this study was provided by a conflict between two competing positions within the current debate over the future of coercive psychiatry. According to one position, defended by the CRPD Committee, among others, compulsory

People who spread misinformation in public debates expose others to the risk of forming false beliefs. Excluding them from participation can limit this exposure, but fact-checking takes up resources of time and money, and censorship violates social and political norms. Here, computer simulations of Bayesian learning in social networks suggest that, in some contexts anyway, the epistemic benefits o

This paper draws on two ethnographic research projects in Japanese university sports clubs to examine the role alcohol plays in the social and cultural education of students. Over the course of a four-year membership, the university sports club is a site where members learn to negotiate drinking. This negotiation is demonstrated by the range of strategies members employ when engaging in one of the