Ian Keith Ludlow

Bio: Ian Keith Ludlow is an academic researcher from University of Hertfordshire. The author has contributed to research in topics: Particle & Light scattering. The author has an hindex of 9, co-authored 16 publications receiving 294 citations. Previous affiliations of Ian Keith Ludlow include Government of the United Kingdom.

Application of neural networks to the inverse light scattering problem for spheres

Abstract: A new approach suitable for solving inverse problems in multiangle light scattering is presented. The method takes advantage of multidimensional function approximation capability of radial basis function neural networks. An algorithm for training the networks is described in detail. It is shown that the radius and refractive index of homogeneous spheres can be recovered accurately and quickly, with maximum relative errors of the order of 10(-3) and mean errors as low as 10(-5). The influence of the angular range of available scattering data on the loss of information and inversion accuracy is investigated, and it is shown that more than two thirds of input data can be removed before substantial degradation of accuracy occurs.

Particle asymmetry analyzer having sphericity detectors

Abstract: An apparatus and method which provides a measure of the asymmetry as well as the size of individual fluid borne particles. Laser-light scattering techniques are employed to obtain data on the particles, which is then compared to data on known particle shapes to ascribe an asymmetry factor to the particles.

Portable particle analysers having plural detectors

Abstract: A portable particle analyzer is compact and can determine the size, geometry and number of particles in a sample of fluid. A laser beam (15) intercepts the flow of fluid (17) at the first focal point of a parabolic mirror (11). Light is scattered and collected by radiation collectors (13) and low angle scattered radiation is detected in a second chamber (19) by reflection by an ellipsoid mirror (20) towards a radiation collector (21). Photomultiplier units (23) convert the radiation collected into electrical signals for analysis.

Particle monitoring system

Abstract: A particle monitoring system to monitor certain properties of individual particles particularly as a function of time. Separate particle monitors (1) record and store data, each having their own key-pad and visual display unit. The data is read and processed by the central master computer (2), which represents the data graphically as a function of time and/or location.

Particle asymmetry analyser

Abstract: An apparatus and method which provides a measure of the asymmetry as well as the size of individual fluid borne particles. Laser-light scattering techniques are employed to obtain data on the particles, which is then compared to data on known particle shapes to ascribe an asymmetry factor to the particles.

Light scattering by particles: Computational methods

Abstract: This book presents the separation-of-variables and T-matrix methods of calculating the scattering of electromagnetic waves by particles. Analytical details and computer programs are provided for determining the scattering and absorption characteristics of the finite-thickness slab, infinite circular cylinder (normal incidence), general axisymmetric particle, and sphere.The computer programs are designed to generate data that is easy to graph and visualize, and test cases in the book illustrate the capabilities of the programs. The connection between the theory and the computer programs is reinforced by references in the computer programs to equations in the text. This cross-referencing will help the reader understand the computer programs, and, if necessary, modify them for other purposes.

Spore formation in Bacillus subtilis

Abstract: Summary Although prokaryotes ordinarily undergo binary fission to produce two identical daughter cells, some are able to undergo alternative developmental pathways that produce daughter cells of distinct cell morphology and fate. One such example is a developmental programme called sporulation in the bacterium Bacillus subtilis, which occurs under conditions of environmental stress. Sporulation has long been used as a model system to help elucidate basic processes of developmental biology including transcription regulation, intercellular signalling, membrane remodelling, protein localization and cell fate determination. This review highlights some of the recent work that has been done to further understand prokaryotic cell differentiation during sporulation and its potential applications.

Apparatus, methods and processes for sorting particles and for providing sex-sorted animal sperm

Abstract: A multi-channel system for classifying particles in a mixture of particles according to one or more characteristics including a common source of electromagnetic radiation for producing a beam of electromagnetic radiation and a beam splitter for producing multiple beams of electromagnetic radiation for directing multiple beams of electromagnetic radiation to each interrogation location associated with each flow channel of the multi-channel system.

Refractive Index Determination of Nanoparticles in Suspension Using Nanoparticle Tracking Analysis

Abstract: The refractive index (RI) dictates interaction between light and nanoparticles and therefore is important to health, environmental, and materials sciences. Using nanoparticle tracking analysis, we have determined the RI of heterogeneous particles <500 nm in suspension. We demonstrate feasibility of distinguishing silica and polystyrene beads based on their RI. The hitherto unknown RI of extracellular vesicles from human urine was determined at 1.37 (mean). This method enables differentiation of single nanoparticles based on their RI.