How reproducible is the acoustical characterization of porous media?

There is a considerable number of research publications on the characterization of porous media that is carried out in accordance with ISO 10534-2 (International Standards Organization, Geneva, Switzerland, 2001) and/or ISO 9053 (International Standards Organization, Geneva, Switzerland, 1991). According to the Web of Science(TM) (last accessed 22 September 2016) there were 339 publications in the Journal of the Acoustical Society of America alone which deal with the acoustics of porous media. However, the reproducibility of these characterization procedures is not well understood. This paper deals with the reproducibility of some standard characterization procedures for acoustic porous materials. The paper is an extension of the work published by Horoshenkov, Khan, Bécot, Jaouen, Sgard, Renault, Amirouche, Pompoli, Prodi, Bonfiglio, Pispola, Asdrubali, Hübelt, Atalla, Amédin, Lauriks, and Boeckx [J. Acoust. Soc. Am. 122(1), 345-353 (2007)]. In this paper, independent laboratory measurements were performed on the same material specimens so that the naturally occurring inhomogeneity in materials was controlled. It also presented the reproducibility data for the characteristic impedance, complex wavenumber, and for some related pore structure properties. This work can be helpful to better understand the tolerances of these material characterization procedures so improvements can be developed to reduce experimental errors and improve the reproducibility between laboratories

Highlights lecture EANM 2015: the search for nuclear medicine’s superheroes

The EANM 2015 Annual Congress, held from October 10th to 14th in Hamburg, Germany, was outstanding in many respects. With 5550 participants, this was by far the largest European congress concerning nuclear medicine. More than 1750 scientific presentations were submitted, with more than 250 abstracts from young scientists, indicating that the future success of our discipline is fuelled by a high number of young individuals becoming involved in a multitude of scientific activities. Significant improvements have been made in molecular imaging of cancer, particularly in prostate cancer. PSMA-directed PET/CT appears to become a new gold standard for staging and restaging purposes. Novel tumour specific compounds have shown their potential for target identification also in other solid neoplasms and further our understanding of tumour biology and heterogeneity. In addition, a variety of nuclear imaging techniques guiding surgical interventions have been introduced. A particular focus of the congress was put on targeted, radionuclide based therapies. Novel theranostic concepts addressing also tumour entities with high incidence rates such as prostate cancer, melanoma, and lymphoma, have shown effective anti-tumour activity. Strategies have been presented to improve further already established therapeutic regimens such as somatostatin receptor based radio receptor therapy for treating advanced neuroendocrine tumours. Significant contributions were presented also in the neurosciences track. An increasing number of target structures of high interest in neurology and psychiatry are now available for PET and SPECT imaging, facilitating specific imaging of different subtypes of dementia and movement disorders as well as neuroinflammation. Major contributions in the cardiovascular track focused on further optimization of cardiac perfusion imaging by reducing radiation exposure, reducing scanning time, and improving motion correction. Besides coronary artery disease, many contributions focused on cardiac inflammation, cardiac sarcoidosis, and specific imaging of large vessel vasculitis. The physics and instrumentation track included many highlights such as novel, high resolution scanners. The most noteworthy news and developments of this meeting were summarized in the highlights lecture. Only 55 scientific contributions were mentioned, and hence they represent only a brief summary, which is outlined in this article. For a more detailed view, all presentations can be accessed by the online version of the European Journal of Nuclear Medicine and Molecular Imaging (Volume 42, Supplement 1)

How reproducible are methods to measure the dynamic viscoelastic properties of poroelastic media?

There is a considerable number of research publications on the acoustical properties of porous media with an elastic frame. A simple search through the Web of Science™ (last accessed 21 March 2018) suggests that there are at least 819 publications which deal with the acoustics of poroelastic media. A majority of these researches require accurate knowledge of the elastic properties over a broad frequency range. However, the accuracy of the measurement of the dynamic elastic properties of poroelastic media has been a contentious issue. The novelty of this paper is that it studies the reproducibility of some popular experimental methods which are used routinely to measure the key elastic properties such as the dynamic Young's modulus, loss factor and Poisson ratio of poroelastic media. In this paper, fourteen independent sets of laboratory measurements were performed on specimens of the same porous materials. The results from these measurements suggest that the reproducibility of this type of experimental method is poor. This work can be helpful to suggest improvements which can be developed to harmonize the way the elastic properties of poroelastic media are measured worldwide

Do legal origins matter? The case of bankruptcy laws in Europe 1808 1914

Since the early 1997 paper by La Porta et al., a growing body of research has argued that legal origins have a country-specific, time-invariant effect on property rights and economic development. Following the methodology of La Porta et al., an original database of 51 bankruptcy laws has been built: it ranges over 15 European countries and more than a hundred years (1808 1914), and summarises how the rights and incentives of the parties were defined as the procedures unfolded. The first conclusion is that, over the entire period, all legal traditions strongly protected creditors rights; only English law comes out prima facie as less protective. Second, evidence suggests that the evolution of these laws was influenced less by their past than by continent-wide trends, arguably linked to capitalist development. An early nineteenth century model thus saw heavy repression of failed debtors and highly regulated judicial procedures. After a transition period from the late 1860s to the late 1880s, prison for debt was abandoned, rehabilitation became easier, and the parties were given much more room to recontract on property rights.

Effets d'un fluide en écoulement uniforme sur le comportement vibro-acoustique d'une plaque bafflée couplée à une cavité rectangulaire

The purpose of this work is to develop a general formulation to deal with the vibro-acoustic behavior of a baffled plate, immersed on one side in a mean flow and coupled on the other side to a rectangular cavity with arbitrary wall impedances. The plate is excited by a plane wave convected by the mean flow. The formulation is based on a finite element method for the calculation of the transverse vibrations of the plate and the acoustic field inside the cavity. The external fluid loading is accounted for through the extended Kirchoff-Helmoltz integral equation and the radiation impedance of the plate in the external fluid is computed with a boundary element method. The mean flow effects on the transmission loss of the plate are discussed

Rayonnement acoustique de structures non bafflées

If the simulation of the radiated field of a baffled plane structure has been deeply studied, the unbaffled case, although more realistic, has retained little attention. The proposed works tend to simulate, by an analytical approach, the radiation of a plane unbaffled structure of finite dimensions and general elastic type of boundary conditions. This approach is based on an integral method coupled with a Ritz approach for the calculus of the displacement field of the structure. The power is evaluated through the pressure jump across the plate. Translation and rotational springs create varying boundary conditions. A good comparison is found with a numerical approach (B.E.M.). Parametric studies showed the effect of the baffle. Precise measurements confirm the validity of the simulations

Enterprise Adjustment and the Role of Bank Credit in Russia: Evidence from a 420 Firms Qualitative Survey

This paper is based on a 1996 industrial survey of 420 Russian firms' actual position, as opposed to their expectations and declared intentions. Factor analysis and ordered Probit techniques are used to test relationships between the various responses. The main conclusions are: 1) profit depends upon real productive performances, and, to a lesser extent, on financial discipline; 2) the demand for credit comes mainly from the worst-off firms or those already indebted; 3) the actual distribution of bank credit is allocated mostly to distressed firms, with poor performance and weak financial position.