43 research outputs found
Volume element structure and roton-maxon-phonon excitations in superfluid helium beyond the Gross-Pitaevskii approximation
We propose a theory which deals with the structure and interactions of volume
elements in liquid helium II. The approach consists of two nested models linked
via parametric space. The short-wavelength part describes the interior
structure of the fluid element using a non-perturbative approach based on the
logarithmic wave equation; it suggests the Gaussian-like behaviour of the
element's interior density and interparticle interaction potential. The
long-wavelength part is the quantum many-body theory of such elements which
deals with their dynamics and interactions. Our approach leads to a unified
description of the phonon, maxon and roton excitations, and has noteworthy
agreement with experiment: with one essential parameter to fit we reproduce at
high accuracy not only the roton minimum but also the neighboring local maximum
as well as the sound velocity and structure factor.Comment: 9 pages, 6 figure
Osmotic dehydration : a cheap and simple method of preserving mangoes, bananas and plantains
Description of osmotic dehydration methods for the preserving of the tropical fruit - mangoes, bananas, plantains
The suitability of simple statistical techniques to remove the atmospheric effects from satellite multi-spectral remote sensing data from inland waters
The application of the covariance matrix atmospheric correction in the remote sensing of reservoirs
Atmospheric correction algorithms for satellite water quality surveillance
Atmospheric correction algorithms for satellite water quality surveillance - ePrints Soton The University of Southampton Courses University life Research Business Global About Visit Alumni Departments News Events Contact × Search the Site Search Filter your search: All Courses Projects Staff University of Southampton Institutional Repository Search Advanced Search Policies & Help Latest Download Statistics Browse by Year Browse by Divisions LeftRight Atmospheric correction algorithms for satellite water quality surveillance Hope, VS, Hadjimitsis, DG and Clayton, CRI (1997) Atmospheric correction algorithms for satellite water quality surveillance. In Observations and Interactions: Proceedings of the 23rd Annual Conference of Remote Sensing Society, Reading. Remote Sensing Society. pp. 268-273 . Record type: Conference or Workshop Item (Paper) This record has no associated files available for download
Helsingin pitäjän kirkon lasimaalaus (1894) : vertaileva analyysi lasimaalauksen alkuperästä
Solar radiation reflected by the Earth's surface to satellite sensors is modified by its interaction with the atmosphere. The objective of atmospheric correction is to determine true surface reflectance values by removing atmospheric effects from satellite images. Atmospheric correction is arguably the most important part of the pre-processing of satellite remotely sensed data and any omission produces erroneous results. The effects of the atmosphere are more severe for dark targets such as water reservoirs. The paper presents two methods of assessing the need for atmospheric correction, and addresses the importance of removing atmospheric effects in the satellite remote sensing of large reservoirs. <br/
An assessment of the effectiveness of atmospheric correction algorithms through the remote sensing of some reservoirs
Although satellite remote sensing techniques have been widely implemented for a variety of applications, using either single or time-series images, few studies have explicitly considered atmospheric effects, and how they can most effectively be minimized. Despite the considerable number of available atmospheric correction algorithms, there is little literature concerning their relative merits. Over water bodies, atmospheric effects account for the majority of the at-satellite measured radiance in the visible bands, and therefore targets of this type provide an opportunity for assessing the effectiveness of the different methods available. This paper reports a study of atmospheric effects and their correction, using multi-spectral satellite remote sensing data for an area to the west of London that includes eight large water reservoirs and a major international airport (Heathrow). Through comparisons of reflectance within a time series of 12 Landsat-5 Thematic Mapper (TM) images, the overall impact of atmospheric contributions is shown. The available atmospheric correction literature is then reviewed, and the methods applied to the satellite imagery of the reservoirs. The results are compared with reflectances acquired using a field spectro-radiometer. A critical appraisal of the results, and of problems encountered in applying the various methods, leads to an evaluation of their value in practice
A new method of removing atmospheric effects using pseudo-invariant targets
A new method of removing atmospheric effects using pseudo-invariant targets - ePrints Soton The University of Southampton Courses University life Research Business Global About Visit Alumni Departments News Events Contact × Search the Site Search Filter your search: All Courses Projects Staff University of Southampton Institutional Repository Search Advanced Search Policies & Help Latest Download Statistics Browse by Year Browse by Divisions LeftRight A new method of removing atmospheric effects using pseudo-invariant targets Hadjimitsis, DG, Clayton, CRI, Hope, VS and Retalis, A. (1999) A new method of removing atmospheric effects using pseudo-invariant targets. 25th Annual Conference and Exhibition of the Remote Sensing Society: Earth Observations - From Data to Information, Swansea, United Kingdom. Record type: Conference or Workshop Item (Paper) This record has no associated files
Cytokine expression in periapical granulation tissue as assessed by immunohistochemistry
The aims of this study were to investigate the expression of pro-inflammatory, anti-inflammatory and immune-related cytokines present in periapical lesions. We investigated the expression of cytokines: namely interleukins IL-2, IL-4, IL-6, IL-10 and interferon-gamma (IFN-gamma) in formalin-fixed, paraffin-embedded sections of periapical granulation tissue. The study samples were biopsies from 24 patients with periapical lesions: 12 with periapical granulomas and 12 patients with radicular cysts. Immunohistochemistry was also performed on tonsillar tissue which served as a control. We utilised a set of specific monoclonal antibodies and polyclonal monospecific antibodies to detect cells that expressed the different cytokines within the tissues. We also considered the nature of the periapical immune response by investigation of the T-helper 1 (Th-1) and T-helper 2 (Th-2) lymphocyte subsets using their cytokine profile, i.e., Th-1: IL-2 and IFN-gamma and Th-2: IL-4, IL-5 and IL-6. Only a few cells were weakly positive for the IL-2 protein in each of the tissue sections. Cells that expressed IL-4 or IL-6 were far more numerous than cells that expressed either IL-2 or IFN-gamma. Thus, we demonstrated a greater number of Th-2 cells in periapical lesions. This relative ratio of the T-cell subsets underlines the importance of the anti-inflammatory mechanisms taking place in the diseased tissue manifested by the wide array of IL-10-expressing cells: B cells, T suppressor cells (CD8 (+)) and tissue macrophages. The numbers of inflammatory cells expressing the anti-inflammatory molecules far outnumbered the cells that expressed pro-inflammatory cytokines. Thus, the downregulation of the inflammatory response and the predominant Th-2 or humoral immune response in periapical periodontitis may be important features that dictate the outcome of the disease process in the periapical lesion