100 research outputs found
Modeling local and global spatial correlation in fieldâscale experiments
Precision agriculture has renewed the interest of farmers and researchers to conduct onâfarm planned comparisons and researchers with respect to fieldâscale research. Cotton yield monitor data collected onâtheâgo from planned fieldâscale onâfarm experiments can be used to make improved decisions if analyzed appropriately. When farmers and researchers compare treatments implemented at larger block designs, treatment edge effects and spatial externalities need to be considered so that results are not biased. Spatial analysis methods are compared for fieldâscale research using siteâspecific data, paying due attention to local and global patterns of spatial correlation. Local spatial spillovers are explicitly modeled by spatial statistical techniques that led to improved farm management decisions in combination with the limited replication strip trial data farmers currently collect
Location patterns of urban industry in Shanghai and implications for sustainability
Chinaâs economy has undergone rapid transition and industrial restructuring. The term âurban industryâ describes a particular type of industry within Chinese cities experiencing restructuring. Given the high percentage of industrial firms that have either closed or relocated from city centres to the urban fringe and beyond, emergent global cities such as Shanghai, are implementing strategies for local economic and urban development, which involve urban industrial upgrading numerous firms in the city centre and urban fringe. This study aims to analyze the location patterns of seven urban industrial sectors within the Shanghai urban region using 2008 micro-geography data. To avoid Modifiable Areal Unit Problem (MAUP) issue, four distance-based measures including nearest neighbourhood analysis, Kernel density estimation, K-function and co-location quotient have been extensively applied to analyze and compare the concentration and co-location between the seven sectors. The results reveal disparate patterns varying with distance and interesting co-location as well. The results are as follows: the city centre and the urban fringe have the highest intensity of urban industrial firms, but the zones with 20â30 km from the city centre is a watershed for most categories; the degree of concentration varies with distance, weaker at shorter distance, increasing up to the maximum distance of 30 km and then decreasing until 50 km; for all urban industries, there are three types of patterns, mixture of clustered, random and dispersed distribution at a varied range of distances. Consequently, this paper argues that the location pattern of urban industry reflects the stage-specific industrial restructuring and spatial transformation, conditioned by sustainability objectives
Modelling and optimization by response surface methodology of chitin extraction From Parapenaeus longirostris by Lactobacillus helveticus
International audienc
A software-based approach for calculating spatially resolved radiation exposure for structural radiation protection in nuclear medical imaging
The objective of the work described is the development of a software tool to provide the calculation routines for structural radiation protection from positron and gamma emitters, for example, 18F. The calculation of the generated local annual dose in the vicinity of these radioactive sources supports the engineering of structural measures necessary to meet regulatory guidelines. In addition to accuracy and precision, a visual and intuitive presentation of the calculation results enables fast evaluation. Finally, the calculated results are presented in a contour plot for design, evaluation, and documentation purposes. A python program was used to provide the calculation routines for structural radiation protection. For simplicity, the radiating sources can be considered as point sources. The attenuation of structural elements can be specified or, in the case of lead, calculated by virtue of its thickness. The calculated attenuation for the lead shielding is always slightly underestimated, which leads to a marginally higher calculated local dose rate than would be physically present. With the conservatively determined value, the structural radiation protection can be optimised in accordance with the general rule of as low as reasonably achievable. The pointwise comparison between the software results and the standard procedure for calculating the dose of points in space leads to similar values. In comparison with the general approach of calculating single representative points in the radiation protection area, the visual and intuitive presentation of the results supports the design and documentation of the measures required for structural radiation protection. In the present version of the software, the local dose rate and local annual dose are overestimated by a maximum of 4.5% in the case of lead shields. The proposed software, termed RadSoft, was successfully used to develop the structural radiation protection of a controlled area for hybrid magnetic resonance - positron emission tomography imaging, with the focus herein being on the requirements for PET
Chitin and Chitosan as Sources of BioâBased Building Blocks and Chemicals
Chitin and chitosan polymers are a valuable source of functional chemicals and materials. Chemical and/or enzymatic depolymerisation processes have been developed for the production of chitooligosaccharides (COS), Nâacetylglucosamine (GlcNAc) and glucosamine (GlcN), which have a wide variety of applications. New technologies are now emerging to convert chitin and its derivatives into platform chemicals. Chemical liquefaction of chitin can lead to bulk chemicals like acetic acid and platform chemicals like hydroxymethylfurfural (HMF) and amineâcontaining monomers for polymers, in low yield. The monomers GlcNAc and GlcN can be converted into Nâcontaining HMF derivatives, opening a pathway for furanâbased monomers for polyamides. Selective catalytic oxidation of GlcN results in the production of Dâglucosaminic acid (DGA). This acid is a valuable building block for the synthesis of various amino acids for biomedical applications and bioâbased chiral polyamides. Further technological improvements are necessary to increase the selectivity and efficiency of reactions, particularly for the conversion of polymeric chitin and chitosan into building blocks.<br/
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