774 research outputs found
The D1-triangulation in simplicial variable dimension algorithms for computing solutions of nonlinear equations
No full textApplication of X-ray Microtomography to Quantify the Liquid Fraction of M2 Steel for Semi-solid Forming process
No full textThixoforging, one variant of semi-solid metal processing in which the metallic alloys are processed at low liquid fraction (0.1< Fl < 0.3), is used to produce complex parts with high mechanical properties. Steel thixoforging faces more challenges as compared to that of low melting point materials due to high processing temperature and lack of understanding of the thermomechanical behavior of materials in the given conditions. It is crucial to study the microstructure in the semi-solid state to improve the understanding of the thixoforging process since the material behavior strongly depends on main parameters: the liquid fraction, its distribution as well as the coherence of the solid skeleton. The microstructure has a great influence on the viscosity of the material, on the flows and finally on the final shape and mechanical properties of the thixoforged parts. Here, the characterization of the volume fraction and distribution of liquid in the semi-solid state with high energy 3D X-ray microtomography is investigated on M2 steel grade as a ‘model’ alloy. The obtained results are compared to 2D observations using EDS technique in SEM on heated and quenched specimens. They show a good correlation making both approaches very efficient for the study of the liquid zones in the semi-solid state
Structural design for Y-type zeolite on large molecule conversion. Alkylation of phenol with long chain olefin.
No full textModified HY zeolites with varying pore size distribution were prepared by combing chemical dealumination and hydrothermal calcination, characterized by x-ray diffraction,Nz adsorption and acidity measurement. Their activities were tested by alkylation of phenol with long chain olefin. The results indicate that the activity enhancement in the modified HY zeolites could be explained by improving accessibility of active acid sites for bulky hydrocarbon molecules.Chemistry, PhysicalSCI(E)
Obesity has an interactive effect with genetic variation in the activating transcription factor 6 gene on the risk of pre-diabetes in individuals of Chinese Han descent.
No full textEndoplasmic reticulum (ER) stress is one of the contributing factors to the development of β-cell failure in type 2 diabetes. ER stress response through ATF6 has been shown to play an important role in insulin resistance and pancreatic β-cell function. We investigated whether genetic polymorphisms in ATF6 were associated with the risk of pre-diabetes in a Chinese Han population, and whether they had a synergistic effect with obesity. Our samples included 828 individuals who were diagnosed as pre-diabetic, and 620 controls. The minor allele A at rs2340721 was associated with increased risk for pre-diabetes(p = 0.013), and this association was still significant after adjusting for gender, age, body mass index (BMI), and waist-hip ratio(p' = 0.011). BMI, treated as a continuous variable, and rs2340721 had an interactive effect on pre-diabetic risk(p for interaction = 0.003, β = 0.106). Carriers of GG at rs7522210 were also at a higher risk compared to non-carriers (OR = 1.390, 95%CI:1.206-1.818, p = 0.013, adjusted OR' = 1.516, 95%CI:1.101-2.006, p' = 0.006). GG homozygotes had increased fasting blood glucose (FBG) levels(GG vs CX: 5.6 ± 0.52 vs 5.5 ± 0.57 mmol/L, p = 0.016), lower insulin levels (0,30,120 minutes after glucose load) (p < 0.05), and reduced areas under the insulin curve than non-carriers(GG vs CX:67.3(44.2-102.3) vs 73.1(49.4-111.4), p = 0.014). rs10918270 was associated with FBG, and rs4657103 with 2 hour glucose levels after a 75 g glucose load. We also identified a haplotype of TTAG composed of rs4657103, rs2134697, rs2340721, and rs12079579, which was associated with pre-diabetes. The genetic variation in ATF6 is associated with pre-diabetes and has interactive effects with BMI on pre-diabetes in the Chinese Han population
High level synthesis for loop-based BIST
No full textArea and test time are two major overheads encountered during data path high level synthesis for BIST. This paper presents an approach to behavioral synthesis for loop-based BIST. By taking into account the requirements of the BIST scheme during behavioral synthesis processes, an area optimal BIST solution can be obtained. This approach is based on the use of test resources reusability that results in a fewer number of registers being modified to be test registers. This is achieved by incorporating self-testability constraints during register assignment operations. Experimental results on benchmarks are presented to demonstrate the effectiveness of the approach.link_to_subscribed_fulltex
Development of a 1-km landcover dataset of China using AVHRR data
No full textThis paper describes the development of a 1-km landcover dataset of China by using monthly NDVI data spanning April 1992 through,March 1993. The method used combined unsupervised and supervised classification of NDVI data from AVHRR. It is composed of five steps: (a) unsupervised clustering of monthly AVHRR NDVI maximum value composites is performed using the ISOCLASS algorithm; (b) preliminary identification is carried our with the addition of digital elevation models, eco-region data and a collection of other landcover/vegetation reference data to identify the clusters with single landcover classes; (c) re-clustering is performed of clusters with size greater than a given threshold value and containing two or more disparate landcover classes: (d) cluster combining is performed to combine all clusters with a single landcover class in one cluster, and all other clusters into one mixed cluster; and (e) supervised classification is used to carry out post-classification of the mixed cluster generated in the previous step by using the maximum likelihood algorithm and the identified single landcover classes of the previous step as training data. The classification is based on extensive use of computer-assisted image processing and tools, as well as the skills of the human interpreter to take the final decisions regarding the relationship between spectral classes defined using unsupervised methods and landscape characteristics that are used to define landcover classes, (C) 1999 Elsevier Science B.V. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000085252600002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Geography, PhysicalGeosciences, MultidisciplinaryRemote SensingImaging Science & Photographic TechnologySCI(E)EI6ARTICLE5-6305-3165
An approach of fast mosaic for serial remote sensing images from UAV
No full textBased on the values of external orientation elements of the camera installed on the unmanned aerial vehicle (UAV), the Nearest neighbor interpolation is adopted to rectify original images geometrically. The range of the overlapping region between two consecutive images is determined by the flying status parameters of UAV. Both of the overlapping regions of the two images are processed to binary image at first. In the appointed binary image region of the former image, feature template is searched and extracted. By the XOR operation, some possible matching positions of the latter image are got. Furthermore, Normalized Correlation method (NC) is adopted to validate the optimal matching position, by which two consecutive images are mosaicked to an image. An intensity transformation function between the two consecutive images is built to smooth the mosaicked image. Simulation experimental results show that the approach presented is effective.Computer Science, Artificial IntelligenceComputer Science, Theory & MethodsEngineering, Electrical & ElectronicEICPCI-S(ISTP)
Rs46522 in the Ubiquitin-Conjugating Enzyme E2Z Gene Is Associated with the Risk of Coronary Artery Disease in Individuals of Chinese Han Population with Type 2 Diabetes
No full textAims. We investigated the association between ubiquitin-conjugating enzyme E2Z (UBE2Z) gene SNP rs46522 and the risk of CAD in a Chinese Han population with type 2 diabetes and explored a possible interactive effect with environmental risk factors of CAD. Methods. 665 patients with T2D were enrolled; 390 were CAD patients and 275 were non-CAD patients. Genotype analysis of rs46522 (T>C) was performed using PCR-RFLP. Results. The SNP rs47522 was associated with the risk of CAD supposing recessive inheritance model (TT versus CC+CT, OR′=1.277, 95%CI′ 1.039–1.570, p′=0.020) and codominant model (TT versus CT, OR′=1.673, 95%CI′ 1.088–2.570, p′=0.019) after adjustment for confounders of CAD. A synergistic effect of rs46522 and BMI was discovered (β=0.012, p for interreaction = 0.028). In subgroup analysis, minor allele T was significantly associated with CAD in overweight and obesity subgroup (p=0.034), and the association was also proved in recessive model (OR=1.537, 95%CI 1.075–2.196, p=0.018). Smokers with genotype TT had threefold risk of CAD in comparison to nonsmokers with genotype TC or CC (p<0.001). Conclusions. The SNP rs46522 in UBE2Z gene is associated with the risk of CAD in the individuals of Chinese Han descent with type 2 diabetes and is of synergistic effect with BMI
Synthesis and structural characterization of (pyrazolyl)alkenyl Fischer carbene complexes of chromium and tungsten
No full textMichael addition of substituted pyrazoles 2 to 1-alkynyl Fischer carbene complexes (CO)(5)M=C(OEt)(CdropCPh) (1) (a, M = Cr and b M = W) afforded (pyrazolyl)alkenyl Fischer carbene complexes (CO)(5)M=C(OEt)(CH=C(R(1)R(2)R(3)pz)Ph) (R(1)R(2)R(3)pz = pyrazolyl) 3 (M = Cr) and 4 (M = W), respectively, with an exclusive (E)-configuration in mild to excellent yields. The reaction of la and 3,5-dimethylpyrazole (2b) was monitored to demonstrate the formation and decomposition of complex 3b by H-1 NMR measurements in CDCl3 at 23degreesC. Complexes 3 and 4 were characterized with H-1, C-13{H-1} NMR, IR spectroscopies and elemental analysis. When the substituted pyrazoles were 3-methylpyrazole (2a) and 3,5-di-tert-butylpyrazole (2d), molecular structures of the corresponding (pyrazolyl)alkenyl Fischer carbene complexes 3a and 4d were characterized by X-ray crystallographic study. (C) 2004 Elsevier Ltd. All rights reserved
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