Gravitational tides are widely understood to strip and destroy galactic substructures. In the course of a galaxy merger, however, transient totally compressive tides may develop and prevent star-forming regions from dissolving after they condensed to form clusters of stars. We study the statistics of such compressive modes in an N-body model of the galaxy merger NGC 4038/39 (the Antennae) and show

The latest edition of the Swiss standard SIA181(2006) Protection against noise in Buildings [1], introduces a new methodology regarding the tests to be performed in new constructions for noise induced by human using service equipment in bathroom and kitchen. In this method, a specific pendling hammer has been developed especially for evaluating the decoupling efficiency of service equipment. The g

Many multifamily houses are produced by small or medium size enterprises (SME's). These developers produce a substantial number of residential units per year. They have normally limited resources and need to have easy access to cost - effective structural solutions. Typical buildings comprise two storeys and four to eight flats. Due to costs and production efficiency these buildings are produced i

The latest Swiss standard SIA181 (6-2006 edition [1]) introduces a new methodology regarding the tests to be performed in new constructions for assessing noise induced by the manipulation of service equipment in bathrooms and kitchens. However, this method has been developed especially for massive constructions. In this study, we are investigating the relevance of such method for timber frame buil

Various modal methods are frequently used to investigate the vibration pattern in construction elements of a building in the low frequency range. The experimental determination of time average transmission and reflection coefficient has been developed for the large scale building structures. In this study, we investigate a mock up of a wall/floor junction. The wave approach is combined with the co

Acoustically robust light weight constructions in multifamily houses require that the building processes are taken into account, i.e. it is necessary to describe in detail how to erect the house on site in order to fulfill the final result. Performance of details necessary for stability reasons, connections in joints, fixing of final strips etc have to be described clearly in order to achieve the

MAX-lab is a national laboratory operated jointly by the Swedish Research Council and Lund University. As of today, the MAX project consists of three facilities, (three storage rings): MAX-I, MAX-II, MAX-III and one electron pre-accelerator called MAX-Injector. A new storage ring is needed at the benefit of material science, such as nanotechnology. MAX-IV will be 100 times more efficient than exis

In Sweden a new research project started in December 2009. The project focuses on light weight constructions and its sound insulation characteristics with respect to subjective response, and it will be carried out during the period of December 2009 to December 2012. The main goal is to develop new evaluation criteria proposals, for the low frequency range and vibrations and their mutual interactio

Lightweight constructions of timber material are cost effective and demands relatively short production duration. One of the main drawbacks of lightweight structures, however, is related to the sound transmission. More and more complains arise against this type of structures, related to the propagation of low frequency vibrations induced by human activities. Most problems are caused by human walki

Each person has a very individual way of walking, though persons having the same sex and the same height, weight and age are likely to have similarities in the angle of the feet and the length of the stride. To simulate this, a number of Markov chains, that describe the stride, were created from experiments with 150 different males. The Markov chains were then used to create an artificial person f

In modern building construction, where light weight structures are preferred for cost reasons, the sound transmission is often a problem to be considered carefully, hence the many studies addressing this issue. Various modal methods are frequently used to investigate the vibration pattern of light weight building structures in the low frequency range. The experimental determination of time average

Timber floors receive a lot of attention nowadays because of their advantages, such as cost effectiveness, recyclability. On the other hand, more and more complains arise again this type of structures, related to the propagation of low frequency vibrations induced by human activities. Most problems are caused by human walking, more exactly foot impacts, which generate a harmonic force whose freque

Multitone signals are often used as excitation for the characterization of audio systems. The frequency spectrum of the response consists of harmonics of the frequencies contained in the excitation and intermodulation products. Beside the choice of frequencies, in order to avoid frequency overlapping, there is also the need to choose adequate magnitudes and phases for the different components that

The characterization of a weakly nonlinear electroacoustic device with usual methods of measurement (THD, intermodulation) does not illustrate the nonlinearities themselves, but only some of their effects. Device linearization can be achieved by applying the inverse nonlinearity upstream of the device, under the condition that the nonlinearity law is known in detail. This paper presents nonlineari

Structure-borne sound attenuation of lightweight timber floor structures has been investigated by high-resolution numerical calculation methods. Two models have been studied both experimentally and numerically. The first considers a continuous chipboard plate and a supporting beam. The second considers two plates that are fastened on one beam. Damping effects, which arise from the two different di

Classical methods of characterization such as Total Harmonic Distortion, SMPTE Intermodulation or Difference Frequency Intermodulation, are widely used for electroacoustic device characterization. However, these methods only put in evidence some of the nonlinear effects for arbitrary excitations, resulting in non-ideal transfer functions, or interaction between two frequencies. More complex effect