Family: Cladophora Kutzing 1843. identification key. [ Translation from: Flora Slodkowodna Polski 10, 227-263, 1972.]

A description of the algal genus Cladophora from Vol 10 of the ”Freshwater Flora of Poland”. Illustrations are included.

Report of the PRA carried out at Nkombe Beach, Uganda, September 2-10, 2000

This document contains the findings of the fourth Participatory Rural Appraisal (PRA) carried out under the LVFRP. Its principal objectives were to develop base-line information on a Ugandan beach for the 3-beaches survey of the LVFRP.

Experimental culture of algal balls (Cladophora sauteri). Retention of original shape [Translation from: Bull.Jap.Soc.Phycol. Vol. 10, (1), p. 23-27, 1962]

It was on July 1960 when 10 algal balls were acquired for exhibition at Suma Aquarium, Kobe. Permission to remove the specimens from the Lake Akan Reserve was given by the National Nature Reserve Committee. Algal balls, as a rule, lose their natural beauty when they are kept in an ordinary tank for a certain length of time. In an effort to retain the natural beauty it was decided to exhibit them in culture. This paper summarises the findings of this experiments with Cladophora sauteri. The author concludes that serious consideration has to be given as to the intensity of light, the sunlight, the water temperature and the nutrition for algal balls in culture in order to retain the natural beauty and shape.

Adaptive image sequence coding based on global and local compensability analysis

Our study of a novel technique for adaptive image sequence coding is reported. The number of reference frames and the intervals between them are adjusted to improve the temporal compensability of the input video. The bits are distributed more efficiently on different frame types according to temporal and spatial complexity of the image scene. Experimental results show that this dynamic group-of-picture (GOP) structure coding scheme is not only feasible but also better than the conventional fixed GOP method in terms of perceptual quality and SNR. (C) 1996 Society of Photo-Optical Instrumentation Engineers.

Spatiotemporal segmentation based on two-dimensional spatiotemporal entropic thresholding

A novel spatiotemporal segmentation technique is further developed for extracting uncovered background and moving objects from the image sequences, then the following motion estimation is performed only on the regions corresponding to moving objects. The frame difference contrast (FCON) and local variance contrast (LCON), which are related to the temporal and spatial homogeneity of the image sequence, are selected to form the 2-D spatiotemporal entropy. Then the spatial segmentation threshold is determined by maximizing the 2-D spatiotemporal entropy, and the temporal segmentation point is selected to minimize the complexity measure for image sequence coding. Since both temporal and spatial correlation of an image sequence are exploited, this proposed spatiotemporal segmentation technique can further be used to determine the positions of reference frames adaptively, hence resulting in a low bit rate. Experimental results show that this segmentation-based coding scheme is more efficient than usual fixed-size coding algorithms. (C) 1997 Society of Photo-Optical Instrumentation Engineers.

Femtosecond optical Kerr effect study of Ge(10)AS(40)S(30)Se(20) film

The results of the femtosecond optical heterodyne detection of optical Kerr effect at 805 nm with the 80 fs ultrafast pulses in amorphous Ge10As40S30Se20 film is reported in this paper. The film shows an optical non-linear response of: 200 fs under ultrafast 80 fs-pulse excitation and the values of real and imaginary parts of non-linear susceptibility chi((3)) were 9.0 X 10(-12) and -4.0 X 10(-12) esu, respectively. The large third-order non-linearity and ultrafast response are attributed to the ultrafast distortion of the electron orbits surrounding the average positions of the nucleus of Ge, As, S and Se atoms. This Ge10As40S30Se20 chalcogenide glass would be expected as a promising material for optical switching technique. (c) 2005 Elsevier Ltd. All rights reserved.

Preparation, characterization and gas sensing properties of lead tetra-(tert-butyl)-5,10,1 5,20-tetraazaporphyrin spin-coating films

A spin-coated film of lead tetra-(tert-butyl)-5,10,15,20-tetraazaporphyrin complex (PbTAP(t-Bu)(4)) was obtained and characterized by IR spectra, absorption spectra and atomic force microscopy. The response and recovery characteristics of the film to NH3, NO2 and C2H5OH vapor were investigated at room temperature. In addition, the reversibility and stability of the film to NH3 were also studied. The results indicate that the PbTAP(t-Bu)(4) derivative can be exploited as an NH3 sensor at room temperature. (c) 2007 Elsevier B.V. All rights reserved.