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One of the challenges in remote sensing image processing is subpixel detection where the target size is smaller than the ground sampling distance, therefore, embedded in a single pixel. Under such a circumstance, these targets can be only detected spectrally at the subpixel level, not spatially as ordinarily conducted by classical image processing techniques. This paper investigates a more challenging issue than subpixel detection, which is the estimation of target size at the subpixel level. More specifically, when a subpixel target is detected, we would like to know 'what is the size of this particular target within the pixel?' The proposed approach is to estimate the abundance fraction of a subpixel target present in a pixel, then find what portion it contributes to the pixel that can be used to determine the size of the subpixel target by multiplying the ground sampling distance. In order to make our idea work, the subpixel target abundance fraction must be accurately estimated to truly reflect the portion of a subpixel target occupied within a pixel. So, a fully constrained linear unmixing method is required to reliably estimate the abundance fractions of a subpixel target for its size estimation. In this paper, a recently developed fully constrained least squares linear unmixing is used for this purpose. Experiments are conducted to demonstrate the utility of the proposed method in comparison with an unconstrained linear unmixing method, unconstrained least squares method, two partially constrained least square linear unmixing methods, sum-to-one constrained least squares, and nonnegativity constrained least squares. Index Terms--Fully constrained least squares (FCLS), fully constrained least squares linear unmixing (FCLSLU), nonnegativity constrained least squares (NCLS), sum-to-one constrained least squares (SCLS), unconstrained least squares (ULS), unsupervised fully constrained least squares linear unmixing (UFCLSLU).

Nitrogen in water will induce active biogeochemical effects, such as denitrification and anammox, which release N2O, a greenhouse gas, leading to increasing global warming. Therefore, it is necessary to find an economical and efficient method to treat ammonia nitrogen in the field of wastewater treatment. In this study, two cation exchange resins, D61 and D708, were selected to analyze external environment conditions suitable for the adsorption of ammonia nitrogen by conducting orthogonal experiments. The kinetic and thermodynamic mechanisms were discussed, and cation exchange resins with a high selectivity to NH4+ were selected. The optimum adsorption temperature, pH, and rotation speed for the D61 resin were found to be 32°C, 5, and 150 r/min, respectively. The optimum adsorption temperature and rotation speed for the D708 resin were 40°C and 150 r/min, respectively. The kinetic data could be accurately described using the pseudo‐second‐order kinetic equation. The results showed that physical and chemical adsorption mechanisms may coexist in the adsorption of NH4+‐N. The adsorption process can easily occur and that it is not limited by the pH or rotational speed. The maximum adsorption capacities of the D61 and D708 resins were 44.93 and 31.34 mg/g, respectively; removing ammonia nitrogen from 1 m3 of wastewater requires only 100–110 g of ion exchange resin. The cost is $1.78/m3 of raw wastewater treated. This is a good alternative to other nitrogen removal systems, particularly in comparison with conventional physicochemical methods and the nitrification–denitrification biochemical process employed currently. [ABSTRACT FROM AUTHOR]

Byline: Fang Ma, Li Wei, Li Wang, Chein-Chi Chang The sulphate-reducing bacteria strain H1 with the function for Hydrolysed Polyacrylamide (HPAM) degradation was isolated from a curing pot in the HPAM distribution station of Daqing Oil Field using the Hungate Anaerobic Technique. The isolates were characterised morphologically, physiologically, biochemically and molecularly. The pictures of the Atomic Force Microscope (AFM) have shown that this is a short bacillus with width 0.300.39 [micro]m and length 0.72-1.63 [micro]m, with flagellum and spores, and is gram negative and strictly anaerobic bacteria, which can reduce sulphate to H2S. Alignment of 16S Ribosomal DNA (rDNA) and 16S23S rDNA intergenic spacer sequences suggests that this isolate was closely related to the Clostridium. Fatty acids were distributed at C12.0-C20,0, mostly at C14.0, C16.0 and C19:11ω12c, the content being 9.10%, 40.01% and 7.11%, respectively, i.e. 56.22% of all fatty acids. The isolate was identified as a new species belonging to fusobacterium, temporarily named Clostridium bifermentans H1. Analysis results of Infrared (IR) spectroscopy showed that the bacteria can use HPAM as the only carbon source, hydrolysing the amide to carboxyl group by the molecule chain amide hydrolysis, degrading the side chain and changing some function group, resulting in obviously decreased viscosity. Using GC-MS determined HPAM-degraded products of low molecular weight compounds were polyacrylamide fragments with duplet bonds, epoxy as well as carbonyl group, but most of them were acrylamide oligomer derivatives. The removing efficiency for HPAM reached 30.8%.

A graphene film deposited on titanium substrate was successfully prepared by a facile solution evaporation method, as electrode exhibiting superior electrosorption property toward methylene blue (MB) from aqueous solution. The fabricated graphene film on titanium substrate was characterized in detail by scanning electron microscopy (SEM) and FTIR techniques. As electrode (GTE) for electrosorption of MB, some experimental parameters, such as applied potential, concentration of electrolyte, solution initial pH and temperature, were systematically investigated and discussed. The experimental results demonstrated that the maximum adsorption capacity using GTE can reach 86.06 mg· g−1 under the optimized conditions of −600 mV of applied potential, pH of 7.5, 293 K and 0.01 mg· L−1 Na2SO4 solution, which is 1.40 times of that obtained under open circuit condition in 10 mg· L−1 MB solution. The adsorption isotherm of MB on GTE was analyzed with Langmuir and Freundlich isotherm equations, Pseudo-first-order model, pseudo-second-order model, and intra-particle diffusion model were applied to depict the adsorption kinetics process. The electrosorption of MB preferably fitted Langmuir isotherm, indicating a single-layer adsorption of MB molecules on graphene film followed pseudo-second-order model. Moreover the electrosorption of MB on GTE was found to be spontaneous and endothermic process. This work would be helpful to design and fabricate high performance carbon-based electrodes for high efficiency electrosorption treatment of dye wastewaters. [ABSTRACT FROM AUTHOR]