The role of noise sensitivity in the noise-response relation: a comparison of three international airport studies

In order to examine the role of noise sensitivity in response to environmental noise, this paper presents detailed comparisons of socio-acoustic studies conducted around international airports in Amsterdam, Sydney, and London. Earlier findings that noise sensitivity moderates the effect of noise on annoyance were examined to see if they could be replicated in each of the datasets, independent of the technique of measuring noise sensitivity. The relation between exposure to aircraft noise and noise annoyance was studied separately for groups of individuals with low, medium, and high noise sensitivity, with statistical adjustment for relevant confounders. Results support the previous findings that noise sensitivity is an independent predictor of annoyance and adds to the prediction of noise annoyance afforded by noise exposure level by up to 26% of explained variance. There is no evidence of a moderating effect, whereby the covariation between noise exposure level and annoyance is weak for people who score at the extreme high or low end of the sensitivity scale, and strong for people who score in the middle of the sensitivity scale. Generally, noise sensitivity appears to increase annoyance independently of the level of noise exposure after adjustment for relevant confounders. These findings were consistent across the three datasets.     

A Neutron Diffraction Study of the Thermal Stability of the α-Quartz-Type Structure in Germanium Dioxide

The structure of the α-quartz-type form of germanium dioxide was refined at room temperature and up to 1344 K by the Rietveld method using time-of-flight neutron powder diffraction data. The intertetrahedral bridging angle θ and the tilt angle δ exhibit thermal stabilities that are among the highest observed in α-quartz homeotypes. The temperature dependence of these angles is found to be a function of the structural distortion in these materials. Structure-property relationships predict that due to its highly distorted structure, germanium dioxide is potentially a high-performance piezoelectric material. The high stability of the above structural parameters as a function of temperature infers that the corresponding piezoelectric properties should also be retained under these conditions. At the present time, problems related to phase stability and crystal growth need to be resolved before the α-quartz-type form of ger-manium dioxide can be used as a piezoelectric material.     

The combinatorics of Bernstein functions

A construction of Bernstein associates to each cocharacter of a split -adic group an element in the center of the Iwahori-Hecke algebra, which we refer to as a Bernstein function. A recent conjecture of Kottwitz predicts that Bernstein functions play an important role in the theory of bad reduction of a certain class of Shimura varieties (parahoric type). It is therefore of interest to calculate the Bernstein functions explicitly in as many cases as possible, with a view towards testing Kottwitz' conjecture. In this paper we prove a characterization of the Bernstein function associated to a minuscule cocharacter (the case of interest for Shimura varieties). This is used to write down the Bernstein functions explicitly for some minuscule cocharacters of ; one example can be used to verify Kottwitz' conjecture for a special class of Shimura varieties (the ``Drinfeld case'). In addition, we prove some general facts concerning the support of Bernstein functions, and concerning an important set called the ``-admissible' set. These facts are compatible with a conjecture of Kottwitz and Rapoport on the shape of the special fiber of a Shimura variety with parahoric type bad reduction.

     

Generation of random fields defined on a cluster of points when the random field has a given site-to-site correlation

A computational scheme for generating a random field defined on a cluster of points with the random field having a site-to-site correlation function close to some desired correlation function is presented. It is assumed that the quantity to be simulated either is, or may be related to, a random quantity having a joint normal distribution with the same variance at each site in the cluster and with a correlation coefficient between sites depending only on the separation of the sites. The scheme can be used for any random quantity which is defined at lattice sites in a cluster and may be applied, for example, to both exchange fields and AB-alloys.     

Solitions and separable elliptic solutions of the sine-Gordon equation

We point out that the two-soliton (antisoliton) solutions of the sine-Gordon equation may be obtained as limiting cases of a separable, two-parameter family of elliptic solutions. The solitons are found on the boundary of the parameter space for the elliptic solutions when the latter are considered over their usual complex domain.     

29Si and 13C NMR studies of organosilicon chemistry. V—Sugar derivatives

²⁹Si spectra have been obtained for four trimethylsilylated hexopyranoside sugars, and the resonance due to the CH₂OSiMe₃ group at position 5 has been assigned by experiments involving gated decoupling at a single ¹H frequency.