21 research outputs found

    Effect of Biodiesel impurities (K, Na, P) on non-catalytic and catalytic activities of Diesel soot in model DPF regeneration conditions

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    Abstract(#br)The impact of Biodiesel impurities (Na, K and P) on the non-catalytic and catalytic reactivity of Diesel soot was evaluated under model DPF (Diesel Particulate Filter) regeneration conditions. Temperature-programmed oxidation (TPO) measurements confirmed that Na and K depositing into soot or on the surface of the catalyst enhanced the oxidative reactivity of soot under both O 2 and NO x + O 2 and Na-doped samples showed better results. However, the presence of P inhibited the non-catalytic and catalytic reactivity. These findings can be mainly attributed to the changes in nanostructure and surface chemical properties of the doped samples, characterized by Raman, high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR) and NO temperature-programmed oxidation (NO-TPO). The result of this characterization evidenced that the presence of Na and K increased structural defects of soot and reduction ability of the catalyst. Moreover, Na-/K-doped catalysts presented higher oxidizing ability of NO into NO 2 , whereas the opposite trend was observed for the P-containing catalysts. In addition, higher structural disorder of Na-doped soot and higher alkali metal content on the surface of Na-doped catalyst might lead to enhanced reactivity in comparison to K-doped soot and catalyst

    Automatic extraction of shorelines from Landsat TM and ETM+ multi-temporal images with subpixel precision

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    A high precision geometric method for automated shoreline detection from Landsat TM and ETM+ imagery is presented. The methodology is based on the application of an algorithm that ensures accurate image geometric registration and the use of a new algorithm for sub-pixel shoreline extraction, both at the sub-pixel level. The analysis of the initial errors shows the influence that differences in reflectance of land cover types have over shoreline detection, allowing us to create a model to substantially reduce these errors. Three correction models were defined according to the type of gain used in the acquisition of the original Landsat images. Error assessment tests were applied on three artificially stabilised coastal segments that have a constant and well-defined land-water boundary. A testing set of 45 images (28 TM, 10 ETM high-gain and 7 ETM low-gain) was used. The mean error obtained in shoreline location ranges from 1.22 to 1.63. m, and the RMSE from 4.69 to 5.47. m. Since the errors follow a normal distribution, then the maximum error at a given probability can be estimated. The results confirm that the use of Landsat imagery for detection of instantaneous coastlines yields accuracy comparable to high-resolution techniques, showing the potential of Landsat TM and ETM images in those applications where the instantaneous lines are a good geomorphological descriptor. © 2012 Elsevier Inc.The authors appreciate the financial support provided by the Spanish Ministerio de Ciencia e Innovacion and the Spanish Plan E in the framework of the Projects CGL2009-14220-C02-01 and CGL2010-19591.Pardo Pascual, JE.; Almonacid Caballer, J.; Ruiz Fernåndez, LÁ.; Palomar-Våzquez, J. (2012). Automatic extraction of shorelines from Landsat TM and ETM+ multi-temporal images with subpixel precision. Remote Sensing of Environment. 123:1-11. doi:10.1016/j.rse.2012.02.024S11112

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    Physical and Mechanical Properties of Modified Wheat Straw-Filled Polyethylene Composites

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    This study investigates the effect of modified wheat straw on the physical and mechanical properties of modified wheat straw/high-density polyethylene (MWS/HDPE) straw-plastic composites. Wheat straw fibers with particle sizes in the range of 0.25 to 0.50 mm were modified with caprolactam (CPL). A Fourier transform infrared spectroscopy (FT-IR) analysis of MWS showed that when the CPL level was 5%, the intensity of the hydroxyl (O–H) and carbonyl (C–O) absorption peaks noticeably decreased, indicating a corresponding decrease in the polarity of the fibers. A physical analysis of the wheat straw fibers indicated that after the modification, the characteristics of the fibers were closer to those of the HDPE polymer matrix, thus contributing to good compatibility and dispersion of the straw fibers within the matrix. The composites of the high-density polyethylene with modified wheat straw particles were successfully synthesized using the melt blend method. The prepared composites were characterized using scanning electron microscopy (SEM), and their mechanical properties were investigated. The MWS/HDPE composites showed superior mechanical properties because of a greater compatibility of MWS with HDPE. The modified WS fibers function as “biological steel,” reinforcing the HDPE to produce bio-composites

    Combining multiaspect factors to predict the risk of childhood hypertension incidence

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    Abstract Childhood hypertension has become a global public health issue due to its increasing prevalence and association with cerebral‐cardiovascular disease in adults. In this study, we developed a predictive model for childhood hypertension based on environmental and genetic factors to identify at‐risk individuals. Eighty children diagnosed with childhood hypertension and 84 children in the control group matched by sex and age from an established cohort were included in a nested case–control study. We constructed a multiple logistic regression model to analyze the factors associated with hypertension and applied the 10‐fold cross‐validation method to verify the prediction stability of the model. Childhood hypertension was found positively correlated with triglyceride level ≄150 mg/dL; low‐density lipoprotein cholesterol level ≄110 mg/dL; body mass index Z score; waist‐to‐height ratio Z score; and red blood cell count (all P < .01) and negatively correlated with the relative expression level of retinol acyltransferase; relative expression level of vitamin D receptor; and dietary intake of fiber, vitamin C and copper (all P < .05) in this study. BMI Z score, triglyceride ≄150 mg/dL, RBC count, VDR/ÎČ‐actin and LRAT/ÎČ‐actin ratios were used to construct the predictive model. The area under the receiver operating characteristic curve was 94.45% (95% CI = 89.35%∌98.65%, P < .001). The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were all above 80% in both the training and validation sets. In conclusion, this model can predict the risk of childhood hypertension and could provide a theoretical basis for early prevention and intervention to improve the cardiovascular health of children

    Seed-borne viral dsRNA elements in three cultivated Raphanus and Brassica plants suggest three cryptoviruses

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    Since the 1970s, several dsRNA viruses, including radish yellow edge virus (RYEV), Raphanus sativus virus 1 (RsV1), Raphanus sativus virus 2 (RsV2) and Raphanus sativus virus 3 (RsV3) have been identified and reported as infecting radish. Here, in conjunction with a survey of seed-borne viruses in cultivated Brassica and Raphanus using the dsRNA diagnostic method, we discovered three novel cryptoviruses that infect Brassica and Raphanus: Raphanus sativus partitivirus 1 (RsPV1), which infects radish (Raphanus sativus); Sinapis alba cryptic virus 1 (SaCV1), which infects Sinapis alba; and Brassica rapa cryptic virus 1 (BrCV1), which infects Brassica rapa. The genomic organization of these cryptoviruses was analyzed and characterized. BrCV1 might represent the first plant partitivirus found in Gammapartitivirus. Additionally, the evolutionary relationships among all of the partitiviruses reported in Raphanus and Brassica were analyzed.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Genome-Wide Analysis of Alternative Splicing and Non-Coding RNAs Reveal Complicated Transcriptional Regulation in Cannabis sativa L.

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    It is of significance to mine the structural genes related to the biosynthetic pathway of fatty acid (FA) and cellulose as well as explore the regulatory mechanism of alternative splicing (AS), microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in the biosynthesis of cannabinoids, FA and cellulose, which would enhance the knowledge of gene expression and regulation at post-transcriptional level in Cannabis sativa L. In this study, transcriptome, small RNA and degradome libraries of hemp ‘Yunma No.1’ were established, and comprehensive analysis was performed. As a result, a total of 154, 32 and 331 transcripts encoding key enzymes involved in the biosynthesis of cannabinoids, FA and cellulose were predicted, respectively, among which AS occurred in 368 transcripts. Moreover, 183 conserved miRNAs, 380 C. sativa-specific miRNAs and 7783 lncRNAs were predicted. Among them, 70 miRNAs and 17 lncRNAs potentially targeted 13 and 17 transcripts, respectively, encoding key enzymes or transporters involved in the biosynthesis of cannabinoids, cellulose or FA. Finally, the crosstalk between AS and miRNAs or lncRNAs involved in cannabinoids and cellulose was also predicted. In summary, all these results provided insights into the complicated network of gene expression and regulation in C. sativa
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