Search

Different oil well tubes have different influences on CO2 corrosion.In order to optimize the materials with the best corrosion resistance to CO2, it is necessary to explore the corrosion of materials of conventional oil well tubes under different conditions.Therefore, taking the production well of CO2 composite flooding injection in Block nine six of Karamay oilfield as the research object, and simulating the actual service condition of oil well pipes, the corrosion weight loss experiments on N80, 3Cr, tungsten-plated heat insulation tube and P110 oil tube materials were carried out.The Potentiodynamic polarization curve and electrochemical impedance spectroscopy(EIS)were measured by three electrode system, scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD)were used to observe the microstructure of corrosion products.Results showed that the corrosion rate of the four kinds of materials increased first and then decreased with the increase of temperature.With the increase of pressure, the corrosion rate of the four kinds of casing steels increased.The corrosion rate of tungsten-plated heat insulation tube and 3Cr was obviously lower than that of N80 and P110.According to the corrosion morphology, the four kinds of casing steels were corroded in varying degrees.The serious corrosion occurred on the surface of N80 and P110 whereas slight corrosion occurred on the surface of the tungsten-plated heat insulation tube and the 3Cr.Therefore, the corrosion law of four oil well tubes in CO2-driven environment was obtained, the suggestions on the design and selection of oil well tubes in CO2-driven environment were proposed to select the materials with the best corrosion resistance to CO2 optimally.

This paper presents details of a large field trial and some observations conducted to evaluate the practical efficiencies of geosynthetically reinforced asphalt pavements in Shanxi Province, China. Three glass-fiber grids (LB2000 II, TGG-8080, GGA 2021), one plastic grid (Tensar AR1), two geotextiles (nonwoven needle-punched and nonwoven heat-bonded), and one geocomposite (Tensar AR-G) application were selected for evaluation. These geosynthetics were installed in the interface between new asphalt pavement layers (APL) and new cement-stabilized gravel-sand base courses coated by emulsified asphalt or within new APL in the reconstruction of asphalt pavement sections (Program I), or in the interface between old APL and new overlay layers in the asphalt overlay pavement sections (Program II). In each program, reinforced sections with different geosynthetics were compared with each other and with nonreinforced sections to determine relative performance. Inspections after construction showed that the integrated damage ratio and deflection in the pavement sections reinforced with glass-fiber grids were less than other pavement sections. Furthermore, after about 4 years of service, glass-fiber grids were dug out and no breaking and node movement were discovered. Nevertheless, observations indicated that geosynthetics may not be effective, if bearing capacity of the base course/subgrade is inadequate, or if the overlay thickness is too thin, or if preconstruction repair of distressed old pavement is incomplete. DOI: 10.1061/(ASCE)0887-3828(2007)21:5(361) CE Database subject headings: Asphalt pavements; Geosynthetics; Reinforcement; Coverings; Field tests; Glass fibers; Grid systems.

Abstract Background Endometrial carcinoma is a common malignancy of female genital tract. Insulin-like growth factor is known to elicit estrogen-induced mitogenic activity and anti-apoptotic effect in endometrial tissues. Methods The retrospective study investigated the expression of insulin-like growth factors, estrogen receptors and their associations in endometrioid adenocarcinoma (EAC) from 80 EAC patients in immunohistochemistry, and 58 EAC patients and 42 control patients in quantitative RT-PCR. The Pearson correlation analysis was used to analyze their correlations with clinic-pathological parameters. Results Our results showed that insulin-like growth factor-1 and insulin-like growth factor-2 mRNA levels were higher in tumor tissues and tumor-adjacent tissues than those in control cells, and were inversely correlated with the malignancy of the tumor with a positive correlation with ERα and ERβ expression. Insulin-like growth factor-1R protein expression was correlated with clinical stage, and insulin-like growth factor-2R protein expression was inversely correlated with histological grade. Conclusions Insulin-like growth factor system plays an important role in estrogen-induced endometrial carcinogenesis, and overexpression of insulin-like growth factor-1R in the advanced endometrioid adenocarcinoma is not estrogen-dependent.

Transfer cells are characterized by an amplified plasma membrane area supported on a wall labyrinth composed of a uniform wall layer (UWL) from which wall ingrowth (WI) papillae arise. Adaxial epidermal cells of developing Vicia faba cotyledons, when placed in culture, undergo a rapid (hours) trans -differentiation to a functional epidermal transfer cell (ETC) phenotype. The trans -differentiation event is controlled by a signalling cascade comprising auxin, ethylene, apoplasmic reactive oxygen species (apoROS), and cytosolic Ca2+. Apoplasmic hydrogen peroxide (apoH2O2) was confirmed as the apoROS regulating UWL and WI papillae formation. Informed by an ETC-specific transcriptome, a pharmacological approach identified a temporally changing cohort of H2O2 biosynthetic enzymes. The cohort contained a respiratory burst oxidase homologue, polyamine oxidase, copper amine oxidase, and a suite of class III peroxidases. Collectively these generated two consecutive bursts in apoH2O2 production. Spatial organization of biosynthetic/catabolic enzymes was deduced from responses to pharmacologically blocking their activities on the cellular and subcellular distribution of apoH2O2. The findings were consistent with catalase activity constraining the apoH2O2 signal to the outer periclinal wall of the ETCs. Strategic positioning of class III peroxidases in this outer domain shaped subcellular apoH2O2 signatures that differed during assembly of the UWL and WI papillae. [ABSTRACT FROM AUTHOR]