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Hydration of dimethyldodecylamine-N-oxide: Enthalpy and entropy driven processes

Dimethyldodecylamine-N-oxide (DDAO) has only one polar atom that is able to interact with water. Still, this surfactant shows very hydrophilic properties: in mixtures with water, it forms normal liquid crystalline phases and micelles. Moreover, there is data in the literature indicating that the hydration of this surfactant is driven by enthalpy while other studies show that hydration of surfactan

Higher order Delaunay triangulations

For a set P of points in the plane, we introduce a class of triangulations that is an extension of the Delaunay triangulation. Instead of requiring that for each triangle the circle through its vertices contains no points of P inside, we require that at most k points are inside the circle. Since there are many different higher-order Delaunay triangulations for a point set, other useful criteria fo

The influence of different technique factors on image quality of chest radiographs as evaluated by modified CEC image quality criteria

The Commission of the European Communities (CEC) research project "Predictivity and optimisation in medical radiation protection" addressed fundamental operational limitations in existing radiation protection mechanisms. The first part of the project aimed at investigating (1) whether the CEC image quality criteria could be used for optimization or a radiographic process and (2) whether significan

Comparisons of the agar-film and membrane-filter methods for the estimation of hyphal lengths in soil, with particular reference to the effect of magnification

The agar-film and membrane filter methods were used to measure total hyphal length in ten different soils. The former method resulted in values 1.1 to 3.9 times those of the latter. Choice of magnification strongly influenced the results. The value for fungal length found at a magnification of 1250 x was 2 times that found at 800 x or 500 x . The measured mean hyphal diameter was significantly sma

Woven convolutional codes I: Encoder properties

Encoders for convolutional codes with large free distances can be constructed by combining several less powerful convolutional encoders. This paper is devoted to constructions in which the constituent convolutional codes are woven together in a manner that resembles the structure of a fabric. The general construction is called twill and it is described together with two special cases, viz., woven

Estimation of the batch-settling flux function for an ideal suspension from only two experiments

Modelling the sedimentation of suspensions with partial differential equations requires constitutive relations (material properties) to be known. Restricted to suspensions obeying Kynch's assumption (ideal suspensions), this paper deals with the inverse problem, which is to estimate the batch-settling flux function from experimental data. A new batch-settling test is suggested, from which it is th

Agrarian diet and diseases of affluence--do evolutionary novel dietary lectins cause leptin resistance?

BACKGROUND: The global pattern of varying prevalence of diseases of affluence, such as obesity, cardiovascular disease and diabetes, suggests that some environmental factor specific to agrarian societies could initiate these diseases. PRESENTATION OF THE HYPOTHESIS: We propose that a cereal-based diet could be such an environmental factor. Through previous studies in archaeology and molecular evol

Concentrations of inorganic elements in bottled waters on the Swedish market

This study presents the concentrations of about 50 metals and ions in 33 different brands of bottled waters on the Swedish market. Ten of the brands showed calcium (Ca) concentrations <= 10 mg L-1 and magnesium (Mg) levels < 3 mg L-1, implying very soft waters. Three of these waters had in addition low concentrations of sodium (Na; < 7 mg L-1), potassium (K; < 3 mg L-1) and bicarbonate (HCO3; <= 3

The nuclear mass at finite angular momenta

The definition of experimental shell energies for nuclear ground states is generalized to finite angular momenta corresponding to a systematic expansion of the (N, Z)-plane to an (N, Z, I) space. Special emphasis is put on high-spin states where it is expected that odd and even nuclei should have similar properties. Different coupling schemes are compared and energetically favoured conditions to b

The subacromial space in normal shoulder radiographs

The subacromial space in standard anteroposterior radiographs of 175 normal shoulders was between 9 and 10 mm. The space was significantly greater in men, with a slight reduction with age. In middle age, a subacromial space less than 6 mm is pathological, possibly indicating supraspinatus tendon rupture.

Chest x ray films from construction workers: International Labour Office (ILO 1980) classification compared with routine readings

The extent of agreement between International Labour Office (ILO) and clinical readings of chest x ray films from construction workers was studied. From a survey of 5898 workers 258 subjects with a profusion of small opacities of > or = 1/1 and a stratified sample of subjects with profusion < 1/1 were selected. Only 41% of the films classified as ILO profusion category > or = 1/1 were clinically r