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51.
José Angel Barrios Miguel Torres-Alvarado Alberto Cavazos Luis Leduc 《Journal of Materials Engineering and Performance》2011,20(7):1128-1139
In hot strip mills, initial controller set points have to be calculated before the steel bar enters the mill. Calculations
rely on the good knowledge of rolling variables. Measurements are available only after the bar has entered the mill, and therefore
they have to be estimated. Estimation of process variables, particularly that of temperature, is of crucial importance for
the bar front section to fulfill quality requirements, and the same must be performed in the shortest possible time to preserve
heat. Currently, temperature estimation is performed by physical modeling; however, it is highly affected by measurement uncertainties,
variations in the incoming bar conditions, and final product changes. In order to overcome these problems, artificial intelligence
techniques such as artificial neural networks and fuzzy logic have been proposed. In this article, neural network-based systems,
including neural-based Gray-Box models, are applied to estimate scale breaker entry temperature, given its importance, and
their performance is compared to that of the physical model used in plant. Several neural systems and several neural-based
Gray-Box models are designed and tested with real data. Taking advantage of the flexibility of neural networks for input incorporation,
several factors which are believed to have influence on the process are also tested. The systems proposed in this study were
proven to have better performance indexes and hence better prediction capabilities than the physical models currently used
in plant. 相似文献
52.
Electroactive behavior assessment of poly(acrylic acid)‐graphene oxide composite hydrogel in the detection of cadmium 下载免费PDF全文
Areli Bejarano‐Jiménez Vladimir A. Escobar‐Barrios J. Mieke Kleijn Cesar A. Ortíz‐Ledón Luis F. Cházaro‐Ruiz 《应用聚合物科学杂志》2014,131(19)
Super absorbent polymers of acrylic acid‐graphene oxide (PAA‐GO) were synthesized with different percentage of chemical neutralization (0, 10, and 20%) of the acrylic acid monomer before its polymerization. The influence of their swelling and adsorption/desorption capacity of cadmium ions in aqueous solutions were studied and revealed that the GO enables greater mechanical stability in the materials. The PAA hydrogels, with the same degrees of neutralization, were also prepared without GO to compare with the composites. Additionally, carbon paste electrodes (CPE) modified with the composites PAA‐GO were used to asses and compare their adsorption properties with cadmium(II). The anodic stripping voltammetry (ASV) peak, in the differential pulse voltammetry mode, for cadmium oxidation was found to be influenced by the presence of GO into the polymer, and also by their percentage of neutralization. The accumulation of cadmium(II) on the surface of the modified CPEs was performed under open‐circuit conditions taking an account the preconcentration time of the metal cation. The presence of GO enhances the electrical signal of the electrodes in short times of immersion in cadmium(II) solutions. This property contributed to get linear responses of the CPEs modified with the composites, which were influenced by their degrees of neutralization. The PAA‐GO 10N electrode with 10% of neutralization combined the influence of GO and the degree of neutralization in the same matrix, and also showed good performance in terms of its mechanical stability, it was chosen for preliminary studies on the selectivity of the electrode toward Zn(II) and Cu(II). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40846. 相似文献
53.
Complex traits are generally taken to be under the influence of multiple genes, which may interact with each other to confer susceptibility to disease. Statistical methods in current use for localizing such genes essentially work under single-gene models, either implicitly or explicitly. In genomic screens for complex disease genes, some of the marker loci must be in tight linkage with disease susceptibility genes. We developed a general multi-locus approach to identify sets of such marker loci. Our approach focuses on affected sib pair data and employs a nonparametric pattern recognition technique using artificial neural networks. This technique analyzes all markers simultaneously in order to detect patterns of locus interactions. When applied to previously published sib pair data on type I diabetes, our approach finds the same genes as in the published report in addition to some new loci. For a specific two-locus model of inheritance, the power of our approach is higher than that of the currently used analysis standard. 相似文献
54.
55.
J Nex?e HE Falk-Petersen S Klit NJ Larsen M Winthereik 《Canadian Metallurgical Quarterly》1998,160(17):2543-2545
The communication of results of HIV tests and chest-X-rays because of persistent coughing are of particular interest because potential life-threatening disease may be disclosed. For HIV tests it is recommended that the result is communicated to the patient in the doctor's office face to face. In this questionnaire study based on two simulated case-stories with a 63 year-old man referred to chest-X-rays because of persistent coughing, and a 27 year-old man, who had been living in Africa for some time, now wanting a HIV test performed, we found that only half (53%) of the general practitioners (GP) did communicate HIV test results in the consultation office. X-ray test results were only communicated in the consultation office by 18% of the GPs. Communication of test results which might have serious implications to the patient should preferably not be done by telephone. Patients should be told of potentially serious results in person by their own physician. 相似文献
56.
57.
OBJECTIVES: To assess the comparability of the Hybritech Tandem-R and Abbott AxSYM PSA assays in the setting of a hospital laboratory changing methods of PSA assay. METHODS: A total of 115 serum samples were tested simultaneously with both reagent kits. These include samples from patients evaluated for screening, benign prostatic hyperplasia, and follow-up of prostate cancer. RESULTS: The outcomes of the Hybritech Tandem-R PSA test ranged from 0.0 to 48.3 ng/mL with a median value of 2.4 ng/mL (mean 3.48, SD 5.46). The outcomes of the Abbott AxSYM PSA test ranged from 0.0 to 49.33 ng/mL with a median of 2.22 ng/mL (mean 3.82, SD 5.59). The outcomes of the two assays were found to be highly correlated by the Pearson correlation coefficient (r = 0.9942). When samples were divided according to PSA levels of 0.0 to less than 2.5, 2.5 to less than 4.0, 4.0 to less than 10.0, and 10.0 to less than 25.0 ng/mL, the outcomes were also highly correlated in all PSA level ranges (r = 0.9619, 0.8094, 0.9167, and 0.9081, respectively). CONCLUSIONS: The PSA values of the Tandem-R and Abbott AxSYM assays are highly correlated in the PSA level ranges of 0.0 to less than 2.5, 2.5 to less than 4.0, 4.0 to less than 10.0, and 10.0 to less than 25.0 ng/mL. 相似文献
58.
PR Moreno JT Fallon VH Bernardi L Harrell NJ Weissman V Fuster A Rodríguez IF Palacios 《Canadian Metallurgical Quarterly》1998,136(5):804-811
BACKGROUND: Early loss of minimal luminal diameter of >0.3 mm after successful percutaneous transluminal coronary angioplasty (PTCA) is associated with a higher incidence of restenosis. The underlying mechanism of this early loss is unknown and thrombus may be a contributing factor. METHODS: We performed a prospective study using quantitative computerized planimetry on coronary tissue specimens obtained by directional coronary atherectomy of 24 lesions in which early loss occurred 22+/-9 minutes after successful PTCA. RESULTS: Thrombus was present in 9 (37%) of 24 coronary specimens. Segmental areas (mm2) and percentage of total area were distributed as follows: sclerotic tissue, 4.07+/-0.7 mm2 (63%+/-6%); fibrocellular tissue, 0.97+/-0.27 mm2 (16%+/-4%); hypercellular tissue, 0.99+/-0.29 mm2 (12%+/-3%); atheromatous gruel, 0.18+/-0.07 mm2 (3%+/-0.1%); and thrombus, 0.24+/-0.15 mm2 (6%+/-0.4%). There was no difference in the relative early loss index between lesions with or without thrombus (35%+/-7% vs 26%+/-2%, respectively; P= .87). Multiple stepwise regression analysis did not identify any histologic predictors of relative early loss index. CONCLUSION: Histopathologic analysis of coronary lesions with early loss after successful PTCA suggests that thrombus may not play a significant role in this angiographic phenomenon. 相似文献
59.
Although arsenite is an established carcinogen, the mechanisms underlying its tumor-promoting properties are poorly understood. Previously, we reported that arsenite treatment leads to the activation of the extracellular signal-regulated kinase (ERK) in rat PC12 cells through a Ras-dependent pathway. To identify potential mediators of the upstream signaling cascade, we examined the tyrosine phosphorylation profile in cells exposed to arsenite. Arsenite treatment rapidly stimulated tyrosine phosphorylation of several proteins in a Ras-independent manner, with a pattern similar to that seen in response to epidermal growth factor (EGF) treatment. Among these phosphorylated proteins were three isoforms of the proto-oncoprotein Shc as well as the EGF receptor (EGFR). Tyrosine phosphorylation of Shc allowed for enhanced interactions between Shc and Grb2 as identified by coimmunoprecipitation experiments. The arsenite-induced tyrosine phosphorylation of Shc, enhancement of Shc and Grb2 interactions, and activation of ERK were all drastically reduced by treatment of cells with either the general growth factor receptor poison suramin or the EGFR-selective inhibitor tyrphostin AG1478. Down-regulation of EGFR expression through pretreatment of cells with EGF also attenuated ERK activation and Shc tyrosine phosphorylation in response to arsenite treatment. These results demonstrate that the EGFR and Shc are critical mediators in the activation of the Ras/ERK signaling cascade by arsenite and suggest that arsenite acts as a tumor promoter largely by usurping this growth factor signaling pathway. 相似文献
60.
WL Gray NJ Gusick C Ek-Kommonen SE Kempson TM Fletcher 《Canadian Metallurgical Quarterly》1995,39(2-3):181-193
Simian varicella virus (SVV) causes a varicella-like disease in nonhuman primates. The DNA sequence and genetic organization of the inverted repeat region (RS) of the SVV genome was determined. The SVV RS is 7559 bp in size with 56% guanine+cytosine (G+C) content and includes 3 open reading frames (ORFs). The SVV RS1 ORF encodes a 1279 amino acid (aa) protein with 58 and 39% identity to the varicella-zoster virus (VZV) gene 62 and herpes simplex virus type 1 (HSV-1) ICP4 homologs, respectively. The predicted 261 aa SVV RS2 polypeptide possesses 52% identity with the VZV gene 63 homolog and 23% identity with the HSV-1 ICP22. The SVV RS3 encodes a 187 aa polypeptide with 56% and 28% identity to the VZV gene 64 and the HSV-1 US10 homologs, respectively, and includes an atypical zinc finger motif. A G+C-rich 16 base-pair (bp) sequence which is repeated 7 times and a putative SVV origin of replication were identified between the RS1 and RS2 ORFs. Comparison with the VZV RS indicates the SVV and VZV RS regions are similar in size and genetic organization. 相似文献