243 research outputs found

    Existence of time periodic solutions for a class of non-resonant discrete wave equations

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    The final publication is available at Springer via http://dx.doi.org/10.1186/s13662-015-0457-zIn this paper, a class of discrete wave equations with Dirichlet boundary conditions are obtained by using the center-difference method. For any positive integers m and T, when the existence of time mT-periodic solutions is considered, a strongly indefinite discrete system needs to be established. By using a variant generalized weak linking theorem, a non-resonant superlinear (or superquadratic) result is obtained and the Ambrosetti-Rabinowitz condition is improved. Such a method cannot be used for the corresponding continuous wave equations or the continuous Hamiltonian systems; however, it is valid for some general discrete Hamiltonian systems

    Strength of Cold-Formed Steel Clip Angle in Combined Bending and Shear Loading

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    Thin-walled cold-formed steel (CFS) clip angles have been commonly used for connecting CFS framing members or attaching CFS members to the major building structure. The implementation of clip angles involves consideration of ultimate strength for combined bending moments and shear forces. Therefore, a test program of CFS clip angle was recently conducted to investigate the behavior and strength of cold-formed steel clip angle subjected to combined bending moments and shear forces at different boundary conditions. The research included connection tests on clip angle. The testing method was adopted from the AISI S914 Test Standard for Joist Connectors Attached to Clod-Formed Structural Framing. This paper presents the details of the test program, test results as well as recommendations for CFS clip angle configurations

    Heuristics for Truck Scheduling at Cross Docking Terminals

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    Cross-docking is a logistics management concept that has been gaining global recognition in less-than-truckload logistics industries and retail firms. In cross-docking terminals, shipments are unloaded from inbound trucks at strip doors, consolidated insider cross-docks according to their destinations, and then, loaded into outbound tucks at stack doors. The goal of cross-docking is to reduce inventory and order picking which are the two most costly functions of traditional warehousing management. The sequence in which the inbound and outbound trucks have to be processed at the cross-dock is crucial for improving the efficiency of cross-docking systems. In this thesis we introduce an integer programming formulation and apply four heuristic algorithms: a local search, a simulated annealing, a large neighborhood search and a beam search, to schedule the trucks in a cross-docking terminal so as to minimize the total operational time

    Load Bearing Clip Angle Design -- Phase II

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    The report presents the second phase of a research project aimed at developing design methods for three limit states of CFS clip angles: shear, compression, and pull-over of the screw connections. In the Phase II work, the research focus was on investigating (1) the fastener pattern effects on the behavior and strength of clip angles; (2) the serviceability of clip angles subjected to tension; (3) the strength and behavior of clip angles subjected to combined shear and bending. Based on the research findings, revision to the Phase I method was proposed to account for the impact of the fastener spacing. Analytical approach to evaluate the serviceability of clip angles in tension was developed. The experimental results of the combined loading verified design equations proposed in this research project

    Tensile Strength and Serviceability of Cold-Formed Steel Clip Angles

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    This paper reports the recent research findings of cold-formed steel clip angles in tension. The relevant experimental program and the proposed design methods are presented. The test program involved two phases of testing: Phase I of program focused on the pull-over strength of screw connections on the anchored leg of the clip angles, and Phase II of program concentrated on the tensile strength of the anchored leg of the clip angles within the service deflection limit. Design methods for predicting the pull-over strength as well as tensile strength within the serviceability deformation limit are proposed based on the test results and analytical analysis. The Allowable Strength Design safety factors and the Load and Resistance Factor Design, Limit State Design resistance factors are also produced to support the proposed design methods

    Clinical Study on Local Application of Lidocaine in Reducing the Rate of Maternal Perineal Incision

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    Objective: To carry out feasibility study and determine the effect of local lidocaine in reducing the rate of maternal perineal incision. Method: A retrospective study of our hospital in January 2010 January 2012, with 80 cases of local application of lidocaine after perineal side cut lying in women and in the same period were randomly selected and 100 cases of conventional guild shade side cut of mother’s surgery as control group. Results: There was no difference between the weight of the newborn and the experimental group at the time of birth. The use of local lidocaine can reduce the rate of maternal perineal incision. Besides, in experimental group it show reduce in maternal postpartum hemorrhage and incision infection, with not increase the incidence of neonatal asphyxia. Conclusion: The use of local lidocaine in reduce the rate of maternal perineal incision is a simple, safe and reliable method to reduce the pain during delivery

    Tumor Necrosis Factor- α

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    Neonatal sepsis (NS) is an important cause of mortality in newborns and life-threatening disorder in infants. The meta-analysis was performed to investigate the diagnosis value of tumor necrosis factor-α (TNF-α) test in NS. Our collectible studies were searched from PUBMED, EMBASE, and the Cochrane Library between March 1994 and August 2013. Accordingly, 347 studies were collected totally, in which 15 articles and 23 trials were selected to study the NS in our meta-analysis. The TNF-α test showed moderate accuracy of the diagnosis of NS both in early-onset neonatal sepsis (sensitivity = 0.66, specificity = 0.76, Q* = 0.74) and in late-onset neonatal sepsis (sensitivity = 0.68, specificity = 0.89, Q* = 0.87). We also found the northern hemisphere group in the test has higher sensitivity (0.84) and specificity (0.83). A diagnostic OR analysis found that the study population may be the major reason for the heterogeneity. Accordingly, we suggest that TNF-α is also a valuable marker in the diagnosis of NS

    Exogenous nitric oxide stimulates early egress of Eimeria tenella sporozoites from primary chicken kidney cells in vitro

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    Egress plays a vital role in the life cycle of apicomplexan parasites including Eimeria tenella, which has been attracting attention from various research groups. Many recent studies have focused on early egress induced by immune molecules to develop a new method of apicomplexan parasite elimination. In this study, we investigated whether nitric oxide (NO), an immune molecule produced by different types of cells in response to cytokine stimulation, could induce early egress of eimerian sporozoites in vitro. Eimeria tenella sporozoites were extracted and cultured in primary chicken kidney cells. The number of sporozoites egressed from infected cells was analyzed by flow cytometry after treatment with NO released by sodium nitroferricyanide (II) dihydrate. The results showed that exogenous NO stimulated the rapid egress of E. tenella sporozoites from primary chicken kidney cells before replication of the parasite. We also found that egress was dependent on intra-parasitic calcium ion (Ca2+) levels and no damage occurred to host cells after egress. The virulence of egressed sporozoites was significantly lower than that of fresh sporozoites. The results of this study contribute to a novel field examining the interactions between apicomplexan parasites and their host cells, as well as that of the clearance of intracellular pathogens by the host immune system

    Transcriptome analysis reveals key differentially expressed genes involved in wheat grain development

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    AbstractWheat seed development is an important physiological process of seed maturation and directly affects wheat yield and quality. In this study, we performed dynamic transcriptome microarray analysis of an elite Chinese bread wheat cultivar (Jimai 20) during grain development using the GeneChip Wheat Genome Array. Grain morphology and scanning electron microscope observations showed that the period of 11–15days post-anthesis (DPA) was a key stage for the synthesis and accumulation of seed starch. Genome-wide transcriptional profiling and significance analysis of microarrays revealed that the period from 11 to 15 DPA was more important than the 15–20 DPA stage for the synthesis and accumulation of nutritive reserves. Series test of cluster analysis of differential genes revealed five statistically significant gene expression profiles. Gene ontology annotation and enrichment analysis gave further information about differentially expressed genes, and MapMan analysis revealed expression changes within functional groups during seed development. Metabolic pathway network analysis showed that major and minor metabolic pathways regulate one another to ensure regular seed development and nutritive reserve accumulation. We performed gene co-expression network analysis to identify genes that play vital roles in seed development and identified several key genes involved in important metabolic pathways. The transcriptional expression of eight key genes involved in starch and protein synthesis and stress defense was further validated by qRT-PCR. Our results provide new insight into the molecular mechanisms of wheat seed development and the determinants of yield and quality
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