222 research outputs found

    Integrated stability mapping system for mines

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    The Integrated Stability Mapping System (ISMS) was developed as an engineering tool to quantify the geologic and geo-mechanical information of mines, and to integrate the critical stability influence factors into an overall stability index for use in mine planning and support design. It is generally understood that the inherent underground roof stability is determined by the interaction of both the given geologic characteristics and the local stress influences. Form this perspective, in this dissertation, the need for an integrated stability mapping system is established through investigating the traditional and current hazard mapping practices. In order to fulfill this need, computer aided hazard mapping techniques and popular numerical methods for geo-mechanical analysis are reviewed. Then, an integrated stability mapping system incorporating geology hazard mapping, geologic structural feature impacts, and advanced numerical stress analysis techniques into one solution has been developed.;The stability system is implemented inside the de-facto standard drawing environment, AutoCAD, and in compatible with widely used geology modeling software SurvCADD. This feature allows one to access numerous existing geologic data and mining information from present mine maps easily and directly. The LaModel stress calculation, a boundary element method, integrated within the mapping system can produce realistic and accurate stress and displacement analysis with its distinguished features such as the laminated overburden model, the true topography consideration and actual irregular pillar matching.;After the stability mapping system was developed, two case studies were performed to check for coding errors, calculation accuracy, and for demonstrating the functionalities and usefulness of the system. In the case studies, the composite stability index was compared with field observations. A good correlation has been found although only a few influence factors have been considered.;In the conclusion of this dissertation, it is suggested that the stability mapping system provides mining engineers with the ability to perform comprehensive, rapid and accurate multiple-factor stability mapping analysis. Then the resultant stability map can be a valuable guide to safer support designing and better mine planning, and ultimately increase the safety of mine design and reduce the injuries and fatalities associated with ground fall in underground mines

    Physicochemical Properties and Lipophilicity of Polydatin-Lecithin Complex

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    Purpose: To investigate the physicochemical properties and lipophilicity of polydatin-lecithin complex.Methods: The complex of polydatin-lecithin was prepared by solvent method. The physicochemical properties of the complex were investigated by ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), differential scanning calorimetry (DSC), x ray diffractometry (XRD) and scanning electron microscopy (SEM). Its solubility in n-octanol at 25 °C was examined by high performance liquid chromatography (HPLC).Results: The UV and IR spectra of the complex showed an additive effect of polydatin-lecithin, in which the characteristic absorption of their respective peaks were retained. DSC and XRD results suggest that the complex mainly showed the presence of lecithin with the characteristic peaks for polydatin absent, while SEM demonstrated that polydatin was dispersed in lecithin. HPLC analysis found that the solubility of polydatin in n-octanol at 25 °C was enhanced from 0.41 mg/mL to 21.98 mg/mL by complexing with lecithin, indicating that the lipophilicity of polydatin was significantly improved.Conclusion: Polydatin and lecithin in the complex are combined by non-covalent bonds, and did not form a new compound. The lipophilicity of polydatin increased to 21.98 mg/mL from 0.41 mg/mL as a result of complexation.Keywords: Polydatin, Lecithin, Complex, Physicochemical property, Lipophilicit

    Enhanced Lipid Production in Chlamydomonas reinhardtii by Co-culturing With Azotobacter chroococcum

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    The green algae, Chlamydomonas reinhardtii, is one of the model species used to study lipid production, although research has focused on nitrogen-deficient cultures, that inhibit the development of biomass by C. reinhardtii and limit lipid production. In this study, Azotobacter chroococcum was added to the algal culture to improve lipid accumulation and productivity of C. reinhardtii. The maximum lipid content and production of C. reinhardtii in the co-culture were 65.85% and 387.76 mg/L, respectively, which were 2.3 and 5.9 times the control's levels of 29.11% and 65.99 mg/L, respectively. The maximum lipid productivity of C. reinhardtii in the co-culture was 141.86 mg/(L·day), which was 19.4 times the control's levels of 7.33 mg/(L·day). These increases were attributed to the enhanced growth and biomass and the change in the activity of enzymes related to lipid regulation (ACCase, DGAT, and PDAT). Compared to the conventional strategy of nitrogen deprivation, A. chroococcum added to the culture of C. reinhardtii resulted in higher lipid accumulation and activity, greater efficiency in the conversion of proteins to lipids, higher biomass, and increased growth of C. reinhardtii. Therefore, using A. chroococcum to improve the growth and biomass of C. reinhardtii is an efficient, rapid, and economically viable strategy for enhancing lipid production in C. reinhardtii

    New freshwater diatom genus, Edtheriotia gen. nov. of the Stephanodiscaceae (Bacillariophyta) from south‐central China

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134437/1/pre12145.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134437/2/pre12145_am.pd

    Reducing Leakage Current and Enhancing Polarization in Multiferroic 3D Super-nanocomposites by Microstructure Engineering

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    Multiferroic materials have generated great interest due to their potential as functional device materials. Nanocomposites have been increasingly used to design and generate new functionalities by pairing dissimilar ferroic materials, though the combination often introduces new complexity and challenges unforeseeable in single-phase counterparts. The recently developed approaches to fabricate 3D super-nanocomposites (3D‐sNC) open new avenues to control and enhance functional properties. In this work, we develop a new 3D‐sNC with CoFe2O4 (CFO) short nanopillar arrays embedded in BaTiO3 (BTO) film matrix via microstructure engineering by alternatively depositing BTO:CFO vertically-aligned nanocomposite layers and single-phase BTO layers. This microstructure engineering method allows encapsulating the relative conducting CFO phase by the insulating BTO phase, which suppress the leakage current and enhance the polarization. Our results demonstrate that microstructure engineering in 3D‐sNC offers a new bottom–up method of fabricating advanced nanostructures with a wide range of possible configurations for applications where the functional properties need to be systematically modified

    Endoplasmic Reticulum Stress Mediated MDRV p10.8 Protein-Induced Cell Cycle Arrest and Apoptosis Through the PERK/eIF2α Pathway

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    In this study, the mechanism of Muscovy duck reovirus (MDRV) p10.8 protein-induced pathogenesis was investigated, with a focus on endoplasmic reticulum (ER) stress. In chicken embryo fibroblasts cell lines (DF1), pCI-neo-flg-p10.8 protein transfection increased the phosphorylation (p-) levels of PERK and eIF2α as shown by Western blotting analysis and led to the dissociation of BiP from PERK as shown by co-immunoprecipitation (Co-IP) analysis. Results of treatment with both ER stress activator and inhibitor further confirmed that p10.8 protein induced ER stress. Subsequently, using flow cytometry analysis, it was also found that p10.8 protein induced cell cycle arrest during the G0/G1 phase. Furthermore, p10.8 transfection increased the phosphorylation levels of PERK and eIF2α, and reduced the expression levels of CDK2, CDK4, and Cyclin E according to Western blotting analysis. Treatment with ER stress activator and ER stress inhibitor after p10.8 protein transfection in DF1 cells further indicated that p10.8 protein induced ER stress, which resulted in cell cycle arrest. The results of knockdown of either PERK or eIF2α genes further confirmed that p10.8 protein-induced ER stress led to cell cycle arrest through the PERK/eIF2α pathway. Further results showed that p10.8 protein induced ER stress and apoptosis in DF1 cells. The expression levels of p-PERK, p-eIF2α, CHOP, cleaved-Caspase12, and cleaved-Caspase3 were increased by p10.8 protein. Test results of treatment with each of Tunicamycin, TUDCA and knockdown of PERK, and eIF2α, confirmed that p10.8 protein induced ER stress involving apoptosis via the PERK/eIF2α pathway. In conclusion, MDRV p10.8 protein induced ER stress that caused cell cycle arrest and apoptosis through the PERK/eIF2α pathway
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