Parallel processors and nonlinear structural dynamics algorithms and software

The adaptation of a finite element program with explicit time integration to a massively parallel SIMD (single instruction multiple data) computer, the CONNECTION Machine is described. The adaptation required the development of a new algorithm, called the exchange algorithm, in which all nodal variables are allocated to the element with an exchange of nodal forces at each time step. The architectural and C* programming language features of the CONNECTION Machine are also summarized. Various alternate data structures and associated algorithms for nonlinear finite element analysis are discussed and compared. Results are presented which demonstrate that the CONNECTION Machine is capable of outperforming the CRAY XMP/14

Application of Contaminant Fate and Transport Models in Saturated Soil

Systems that remediate an aquifer by purging contaminated water often operate for prolonged periods because contamination stubbornly lingers. This is the tailing phenomenon. For nondegradable, nonionic organics in ground water, sorption is the prominent reaction. Sorption is crucial to the tailing phenomenon. Types of sorption rate expressions include (1) local equilibrium, (2) Langmuir second order, (3) equilibrium/first order, and (4) dual resistance sorption. Types of equilibrium isotherms include (1) linear, (2) Freundlich, or (3) Langmuir equilibrium. This work improves four existing contaminant transport simulator models; each model incorporates one sorption rate assumption. Based on modeling of the ground water contaminant nitrobenzene on Ann Arbor granular aquifer material in laboratory soil column reactors, the rate-controlled models predict contaminant breakthrough better than the local equilibrium models. In one field-scale simulation all nonlinear and nonequilibrium models display the tailing phenomenon. The linear local equilibrium model does not.Master of Science in Environmental Engineerin

Trust and mutual gains approach : negotiations between Westerners and Chinese

The Chinese economy has experienced an exceptional growth and an increasing number of Western companies are negotiating agreements with Chinese business partners. Cross-cultural difficulties are obstacles in achieving efficiency in negotiations. This thesis will discuss trust in the context of the mutual gains approach of negotiations with Westerners and Chinese

Genetic polymorphisms of MMP1, MMP3 and MMP7 gene promoter and risk of colorectal adenoma

BACKGROUND: Matrix metalloproteinases (MMP) have been shown to play a role in colorectal cancer (CRC). More recently, MMP1, MMP3 and MMP7 functional gene promoter polymorphisms have been found to be associated with CRC occurrence and prognosis. To document the role of MMP polymorphisms in the early step of colorectal carcinogenesis, we investigated their association with colorectal adenoma risk in a case-control study comprising 295 patients with large adenomas (LA), 302 patients with small adenomas (SA) and 568 polyp-free (PF) controls. METHODS: Patients were genotyped using automated fragment analysis for MMP1 -1607 ins/del G and MMP3 -1612 ins/delA (MMP3.1) polymorphisms and allelic discrimination assay for MMP3 -709 A/G (MMP3.2) and MMP7 -181 A/G polymorphisms. Association between MMP genotypes and colorectal adenomas was first tested for each polymorphism separately and then for combined genotypes using the combination test. Adjustment on relevant variables and estimation of odds ratios were performed using unconditional logistic regression. RESULTS: No association was observed between the polymorphisms and LA when compared to PF or SA. When comparing SA to PF controls, analysis revealed a significant association between MMP3 -1612 ins/delA polymorphism and SA with an increased risk associated with the 6A/6A genotype (OR = 1.67, 95%CI: 1.20–2.34). Using the combination test, the best association was found for MMP3.1-MMP1 (p = 0.001) with an OR of 1.88 (95%CI: 1.08–3.28) for the combined genotype 2G/2G-6A/6A estimated by logistic regression. CONCLUSION: These data show a relation between MMP1 -1607 ins/del G and MMP3 -1612 ins/delA combined polymorphisms and risk of SA, suggesting their potential role in the early steps of colorectal carcinogenesis

Experimental Study of Small-Scale R/C Columns Subjected to Axial and Shear Force Reversals

Small-scale reinforced concrete columns were subjected to a series of shear force or simultaneous shear and axial force reversals. The specimens were similar to the first story columns of the nine-story, three-bay frames tested dynamically on the University of Illinois Earthquake Simulator. Test variables included the reinforcement ratio~ the dead load on the column, and the rate of axial load variation during shear force reversals. Behavior of the specimens, is represented by measured hysteresis relations and crack patterns. The observed behavior is compared with the calculated response.National Science Foundation Research Grant PFR 78-1631