Colour superconductivity in finite systems

In this paper we study the effect of finite size on the two-flavour colour superconducting state. As well as restricting the quarks to a box, we project onto states of good baryon number and onto colour singlets, these being necessary restrictions on any observable ``quark nuggets''. We find that whereas finite size alone has a significant effect for very small boxes, with the superconducting state often being destroyed, the effect of projection is to restore it again. The infinite-volume limit is a good approximation even for quite small systems.Comment: 14 pages RevTeX4, 12 eps figure

Cosmic shear requirements on the wavelength-dependence of telescope point spread functions

Cosmic shear requires high precision measurement of galaxy shapes in the presence of the observational Point Spread Function (PSF) that smears out the image. The PSF must therefore be known for each galaxy to a high accuracy. However, for several reasons, the PSF is usually wavelength dependent, therefore the differences between the spectral energy distribution of the observed objects introduces further complexity. In this paper we investigate the effect of the wavelength-dependence of the PSF, focusing on instruments in which the PSF size is dominated by the diffraction-limit of the telescope and which use broad-band filters for shape measurement. We first calculate biases on cosmological parameter estimation from cosmic shear when the stellar PSF is used uncorrected. Using realistic galaxy and star spectral energy distributions and populations and a simple three-component circular PSF we find that the colour-dependence must be taken into account for the next generation of telescopes. We then consider two different methods for removing the effect (i) the use of stars of the same colour as the galaxies and (ii) estimation of the galaxy spectral energy distribution using multiple colours and using a telescope model for the PSF. We find that both of these methods correct the effect to levels below the tolerances required for per-cent level measurements of dark energy parameters. Comparison of the two methods favours the template-fitting method because its efficiency is less dependent on galaxy redshift than the broad-band colour method and takes full advantage of deeper photometry.Comment: 10 pages, 8 figures, version accepted for publication in MNRA

Influence of Weave and Densities on Visual Appearance of Woven Fabrics Made From Two Colored Yarns

The paper examines the effect of different factors, i.e. weft density, weave type and consequently agglomeration of the interlacing points of the same type, on the colour impression of a woven fabric. The experimental part is based on 60 weaved samples which differ in weave type (we used 10 different weave types in which the technical face and technical back are the same), colour of the warp (we used white and black warp) and weft density (we used yarns with densities 15, 20 and 25 yarns / cm). We measured the colour values of the woven samples. We arranged the measurements in different ways and tried to visually evaluate the effect of density, effect of weave type, also the effect of the size and shape of agglomerated interlacing points of the same type, on the colour impression of the woven fabric. The results of the colour measurements were sorted into tables and presented in graphs, which were used to find the samples within the observed groups of characteristics that showed the biggest colour differences, to calculate these colour differences and observe and explain the effect of the observed factors on the colour impression

Estimating drizzle drop size and precipitation rate using two-colour lidar measurements

A method to estimate the size and liquid water content of drizzle drops using lidar measurements at two wavelengths is described. The method exploits the differential absorption of infrared light by liquid water at 905 nm and 1.5 μm, which leads to a different backscatter cross section for water drops larger than ≈50 μm. The ratio of backscatter measured from drizzle samples below cloud base at these two wavelengths (the colour ratio) provides a measure of the median volume drop diameter D0. This is a strong effect: for D0=200 μm, a colour ratio of ≈6 dB is predicted. Once D0 is known, the measured backscatter at 905 nm can be used to calculate the liquid water content (LWC) and other moments of the drizzle drop distribution. The method is applied to observations of drizzle falling from stratocumulus and stratus clouds. High resolution (32 s, 36 m) profiles of D0, LWC and precipitation rate R are derived. The main sources of error in the technique are the need to assume a value for the dispersion parameter μ in the drop size spectrum (leading to at most a 35% error in R) and the influence of aerosol returns on the retrieval (≈10% error in R for the cases considered here). Radar reflectivities are also computed from the lidar data, and compared to independent measurements from a colocated cloud radar, offering independent validation of the derived drop size distributions

The Stroop revisited: a meta-analysis of interference control in AD/HD

Background: An inhibition deficit, including poor interference control, has been implicated as one of the core deficits in AD/HD. Interference control is clinically measured by the Stroop Colour-Word Task. The aim of this meta-analysis was to investigate the strength of an interference deficit in AD/HD as measured by the Stroop Colour-Word Task and to assess the role of moderating variables that could explain the results. These moderating variables included: methods of calculating the interference score, comorbid reading and psychiatric disorders, AD/HD-subtypes, gender, age, intellectual functioning, medication, and sample size. Methods: Seventeen independent studies were located including 1395 children, adolescents, and young adults, in the age range of 6-27 years. A meta-analysis was conducted to assess the effect sizes for the scores on the word and the colour card as well as the interference score. Results: Children with AD/HD performed more poorly on all three dependent variables. The effect sizes for word reading (d = .49) and colour naming (d = .58) were larger and more homogeneous than the effect size for the interference score (d = .35). The method used to calculate the interference score strongly influenced the findings for this measure. When interference control was calculated as the difference between the score on the colour card minus the score on the colour-word card, no differences were found between AD/HD groups and normal control groups. Discussion: The Stroop Colour-Word Task, in standard form, does not provide strong evidence for a deficit in interference control in AD/HD. However, the Stroop Colour-Word Task may not be a valid measure of interference control in AD/HD and alternative methodologies may be needed to test this aspect of the inhibitory deficit model in AD/HD. © Association for Child Psychology Psychiatry, 2004

The effect of colour and size on attentional bias to alcohol-related pictures

"Attentional bias plays an important role in the development and maintenance of alcohol addiction, and has often been measured with a visual probe task, where reaction times are compared for probes replacing either a substance related cue or a neutral cue. Systematic low-level differences between image classes are a potential cause of low internal reliability of the probe task (Ataya et al., 2012). Moreover, it is unclear whether automatic attentional capture by low-level properties such as size and colour in the non-substance related image could reduce attentional bias to the alcohol-related cue. Here, alcohol-related attentional bias was assessed in moderate social drinkers by measuring reaction times to targets that replaced either an alcohol related or a non-alcohol related (i.e., neutral) picture. All alcohol-related images were greyscale, and the neutral stimulus could be either greyscale (‘control’), in colour (‘colour’), or greyscale and 25% larger in size (‘25% larger size’). We found attentional bias towards the alcohol-related stimuli in the control and 25% larger size conditions, but not in the colour condition. The magnitude of attentional bias was significantly reduced in the colour condition compared to the control and 25% larger size conditions. These findings indicate that salient low-level features in the non-substance related cue, in particular colour, can reduce the effect of alcohol-related content on the allocation of alcohol drinkers’ attention. Further, the results highlight the need for image pairs in visual probe tasks to be closely matched on basic perceptual dimensions.

Factors influencing colour production from the sugar medium used for the rapid approximation of bacterial counts in fishery products

Results of the studies carried out to elucidate the factors influencing colour production from the sugar medium used for the rapid approximation of bacterial counts in fishery products are reported. The effect of particle size, trace elements, salt soluble protein and non-protein fractions, rate of multiplication of bacteria, in the medium, surface bacteria and the rate of colour production by individual strains of bacteria were studied. It is observed that the best results are obtained when a sea-water homogenate is used

Modelling and determination of physico-chemical and morphological properties of microencapsulated red amaranth powder

Amaranth betacyanin, responsible for a red or violet colour, is extracted from Amaranthus gangeticus by using the water extraction method and microencapsulated by spray drying. The physicochemical and morphological properties of microencapsulated betacyanins are assessed as influenced by the inlet temperature and the maltodextrin concentration. The process was conducted using a mini spray dryer and maltodextrin is used as an encapsulating agent. Central composite design is applied and thirteen experiments are carried out. The responses are betacyanin retention, moisture content, water activity, particle densities, particle size, colour values and antioxidant activity. The quadratic effect of the inlet temperature is determined to be positive on betacyanin retention whereas the antioxidant is affected by the linear change of maltodextrin concentration. The moisture content and water activity of spray-dried betacyanin powders are insignificantly affected by inlet temperature and maltodextrin concentration individually. Only the effect maltodextrin concentration is found to have a significant effect on colour value. Particle densities and sizes are slightly affected by the process conditions studied

On the colour of noctilucent clouds

The high-latitude phenomenon of noctilucent clouds (NLCs) is characterised by a silvery-blue or pale blue colour. In this study, we employ the radiative transfer model SCIATRAN to simulate spectra of solar radiation scattered by NLCs for a ground-based observer and assuming spherical NLC particles. To determine the resulting colours of NLCs in an objective way, the CIE (International Commission on Illumination) colour-matching functions and chromaticity values are used. Different processes and parameters potentially affecting the colour of NLCs are investigated, i.e. the size of the NLC particles, the abundance of middle atmospheric O3 and the importance of multiply scattered solar radiation. We affirm previous research indicating that solar radiation absorption in the O3 Chappuis bands can have a significant effect on the colour of the NLCs. A new result of this study is that for sufficiently large NLC optical depths and for specific viewing geometries, O3 plays only a minor role for the blueish colour of NLCs. The simulations also show that the size of the NLC particles affects the colour of the clouds. Cloud particles of unrealistically large sizes can lead to a reddish colour. Furthermore, the simulations show that the contribution of multiple scattering to the total scattering is only of minor importance, providing additional justification for the earlier studies on this topic, which were all based on the single-scattering approximation.</p