Photovoltaic (PV) systems are a very popular energy conversion system for electric supply due to their ease of connection and fast rate conversion. However, disadvantage these is low efficiency. Many techniques have been proposed enhance the efficiency PV systems. In this article, numerical experimental studies were performed test effect pyramidal transparent covers made Perspex on incident rad...

Introduction SPECT projections are contaminated by scatter radiation, resulting in reduced image contrast and quantitative errors. Backscatter constitutes a major part of the scatter contamination in lower energy windows. The current study is an evaluation of the effect of backscatter material on FWHM and image quality investigated by Monte Carlo simulation. Materials and Methods SIMIND program...

Abstract Background The artificial mussel (AM) is a passive sampling device that was originally developed for monitoring metal concentrations in the marine environment, but also increasingly used freshwater environments. AM consists of non-permeable Perspex tube, which closed on both sides with semi-permeable membrane. space between contains Chelex-100 beads, bind metals. allows determination d...

The symbiotic ant partners of glaucous Macaranga ant-plants show an exceptional capacity to run on the slippery epicuticular wax crystals covering the plant stem without any difficulty. We test the hypothesis that these specialised 'wax-runners' have a general, superior attachment capacity. We compared attachment on a smooth surface for 11 ant species with different wax-running capacities. The ...

Ž . Ž . Hatchery-reared king scallop Pecten maximus L. spat 5–14 mm shell height were held in mesh-based Perspex cylinders suspended in 2.5 l beakers of seawater. This seawater was Ž . Ž maintained at eight temperatures 58C–238C inclusive , and various rations 0.012–0.492 g Ž . y1 Ž . y1. organic weight of algae g live weight of spat week of a diet consisting of a mixture of Ž . PaÕloÕa lutheri...

When a shear ultrasonic wave is incident on a solid and liquid boundary, the proportion that is reflected depends on the liquid viscosity. This is the basis for some instruments for on-line measurement of bulk liquid viscosity. In machine elements, the lubricant is usually present in a thin layer between two rubbing solid surfaces. The thin film has a different response to an ultrasonic shear w...

We present an experimental study of the vitreous motion induced by saccadic eye movements. A magnified model of the vitreous chamber has been employed, consisting of a spherical cavity carved in a perspex cylindrical container, which is able to rotate with a prescribed time law. Care has been taken to correctly reproduce real saccadic eye movements. The spherical cavity is filled with glycerol ...

Prolonged interaction with cage bars by captive mammals (usually classed as stereotypic) may reflect poor welfare. Such behaviour may arise from motivation to investigate the external environment or to escape captivity. However, these hypotheses have not been explicitly tested. We raised mice, Mus musculus, to adulthood in modified laboratory cages with two sets of bars at the top and side of t...

In an investigation of recognition memory involving a preference test, hooded rats of both sexes were individually confined to the stem and choice area of a Tor Y-maze by means of clear Perspex barriers across each arm entrance that enabled the subjects to see into but not enter the arms. Following removal of the barriers and changing of one arm to opposite brightness, the first arm entered and...

Background: The compositions of Ferrous sulphate, Agarose and Xylenol orange dye (FAX) and Ferrous sulphate, Gelatin and Xylenol orange dye (FGX) in solution of distilled water and sulphuric acid are two tissue-equivalent gel dosimeters. Ionizing radiation causes oxidation of Fe ion to Fe ions which diffuse through the gel matrix and blur the image of absorbed dose over a period of hours after ...