Are surfaces' colours judged from weighted averages of the light that they reflect to the eyes and the colour contrast at their borders? To find out we asked subjects to set the colour and luminance of test disks to match reference disks, on various backgrounds, and analysed the variability in their settings. Most of the variability between repeated settings was in luminance. The standard devia...

The microbial decolourization of Reactive Red 2 (RR2) dye has been studied under anaerobic conditions. Three semicontinuous bioreactors were operated with dye concentrations—R1 (control: 0 mg RR2 l−1), R2 (100 mg RR2 l−1) and R3 (200 mg RR2 l−1). The parameters monitored were, oxidation–reduction potential (ORP), methane production, colour and chemical oxygen demand (COD) removal during the fee...

carotenoids are the main pigments of tomato, of which 93% is lycopene. lycopene has desirable physiological effects in human sush as cancer prevention. recent years, because of harmful side effects of synthetic colouring agents used in food products, employing of natural food colouring agents has become very important. in this research firstly, solvent extraction method was used for tomato caro...

We define some new algebraic structures, termed coloured Hopf algebras, by combining the coalgebra structures and antipodes of a standard Hopf algebra set H, corresponding to some parameter set Q, with the transformations of an algebra isomorphism group G, herein called colour group. Such transformations are labelled by some colour parameters, taking values in a colour set C. We show that vario...

Computer vision based face and gesture recognition will allow future human computer interfaces to be more intuitive and user-friendly than traditional interfaces. A crucial processing step for the success of such systems is robust detection and tracking of faces and hands, which is frequently done by combining complementary cues, e.g., motion, shape, and colour. Skin colour is often used becaus...

This study examined the effect of the colour of light on growth performance, feed and water intake, behaviour and latency to lie (LTL) in broiler chickens. Ninety six broiler (Hybro P.G. Plus) chicks were divided into two groups and reared in 12 cages that received either red or white colour light (20 lux) during night for 8 hrs per day from 14-36 d of age. Water and feed were provided ad libit...

Using a widely used stellar population synthesis model, we study the ability of using pairs of AB system colours to break the well-known stellar age–metallicity degeneracy and give constraints on two luminosity-weighted stellar-population parameters (age and metallicity). The relative age and metallicity sensitivities of AB system colours that relate to u, B, g, V , r, R, i, I, z, J , H , and K...

      Background: Computed tomography scans (CT scan) and X-rays are used to diagnose paediatric maxillary sinusitis. This study aimed at exploring the diagnostic value of the conventional and colour Doppler ultrasounds and their specific findings in cases of paediatric sinusitis.    Methods: A total of 60 children diagnosed with sinusitis were included in this s...