Evaluation of the material’s damage in gas turbine rotors by instrumented spherical indentation

Experimental indentations are carried out on items of two different materials, taken in severallocation of various components from high pressure gas turbine rotor which have seen an extensive service. Thecomponents object of investigation consisted in 1st and 2nd high pressure turbine wheels made in nickel-basesuperalloy (Inconel 718), the spacer ring (Inconel 718) and the compressor shaft made in CrMoV low alloy steel(ASTM A471 type10).Aim of the work is to set up the capability of the instrumented spherical indentation testing system to evaluatevariations in the material properties due to damage, resulting from temperature field and stresses acting oncomponents during service. To perform this task load-indentation depth curves will be acquired in variouszones of the above mentioned components. The analysis of the results has allowed to identify an energyparameter which shows a linear evolution with the mean temperature acting on the components

Aging characterization of metals for exhaust systems

The mechanical characteristics of four materials used in automotive exhaust systems have been compared after an aging treatment to evaluate the combined effects of thermo-mechanical fatigue and corrosion. For this purpose, an experimental aging procedure has been developed. This procedure is composed of chemical, thermal and mechanical cycles, which are combined and repeated to simulate the actual operating conditions of automotive exhaust systems. Three austenitic steels (AISI 309, AISI 316Ti, and AISI 321) and a nickel-based alloy (Inconel 625) are tested. The results show that Inconel 625 and AISI 309 are less affected by the aging process than the other material

Effect of cyclic heat treatment process on the pitting corrosion resistance of EN-1.4405 martensitic, EN-1.4404 austenitic, and EN-1.4539 austenitic stainless steels in chloride-sulfate solution.

The effect of high temperature variation on the corrosion resistance of EN-1.4405, EN-1.4404, and EN-1.4539 stainless steels in 2 M H2SO4/3.5% NaCl solution was studied. Untreated EN 1.4405 exhibited the highest corrosion rate at 4.775 mm/year compared to untreated EN 1.4539 with the lowest corrosion rate (1.043 mm/year). Repetitive heat treatment significantly decreased the corrosion rate of the steels by 54.61%, 27.83%, and 50.28% to 2.167, 1.396, and 0.519 mm/year. EN-1.4539 steel exhibited the shortest metastable pitting activity among the untreated steels due to higher resistance to transient pit formation while heat treated EN-1.4404 and EN-1.4539 steels exhibited double metastable pitting activity. Heat treated EN-1.4405 was unable to passivate after anodic polarization signifying weak corrosion resistance. Pitting current of heat-treated steels was generally higher than the untreated counterparts. Heat treatment extended the passivation range value of EN-1.4405 and EN-1.4539 steels compared to those of the untreated steels. The corrosion potential of heat-treated steels significantly shifted to electronegative values. The optical image of untreated and heat treated EN-1.4404 and EN-1.4539 steels were generally similar while the images for EN-1.4405 significantly contrast each other

Phospho-TCTP as a therapeutic target of Dihydroartemisinin for aggressive breast cancer cells

Upregulation of Translationally Controlled Tumor Protein (TCTP) is associated with poorly differentiated aggressive tumors, including breast cancer, but the underlying mechanism(s) are still debated. Here, we show that in breast cancer cell lines TCTP is primarily localized in the nucleus, mostly in the phosphorylated form.The effects of Dihydroartemisinin (DHA), an anti-malaria agent that binds TCTP, were tested on breast cancer cells. DHA decreases cell proliferation and induces apoptotic cell death by targeting the phosphorylated form of TCTP. Remarkably, DHA enhances the anti-tumor effects of Doxorubicin in triple negative breast cancer cells resulting in an increased level of apoptosis. DHA also synergizes with Trastuzumab, used to treat HER2/neu positive breast cancers, to induce apoptosis of tumor cells.Finally, we present new clinical data that nuclear phospho-TCTP overexpression in primary breast cancer tissue is associated with high histological grade, increase expression of Ki-67 and with ER-negative breast cancer subtypes. Notably, phospho-TCTP expression levels increase in trastuzumab-resistant breast tumors, suggesting a possible role of phospho-TCTP as a new prognostic marker.In conclusion, the anti-tumor effect of DHA in vitro with conventional chemotherapeutics suggests a novel therapeutic strategy and identifies phospho-TCTP as a new promising target for advanced breast cancer

Abundance and patterns of occurence [occurrence] in butterflies from Ailsa Craig, Ayrshire

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