Deformation Mechanisms and Strain Storage During Forging of Powder-Metallurgy Nickel-base Turbine Disk Alloy

Nickel-based superalloys account for 50% of the total weight of high temperature gas turbine engines. Increasing the lifespan and temperature capabilities of superalloy turbine blades and disks can significantly increase the efficiency and cost of the engines. The properties of superalloy disk materials, including strength and fatigue resistance, are sensitive to the grain structure at the end of a series of thermomechanical processing. To date, there have been few fundamental studies on deformation mechanisms and microstructural evolution under conditions relevant to forging of superalloy disk materials. In this study, high temperature compression testing combined with high resolution Electron Backscatter Diffraction (EBSD) analysis has been used to analyze microstructural-scale straining processes that occur during high temperature deformation of a powder-consolidated nickel-based superalloy, René 88DT. Orientation imaging has been employed to study grain-level straining and strain storage at temperatures, strains, and strain rates of interest. Two distinct deformation mechanisms were observed using these techniques. At strain rates below 0.001/s, superplastic deformation dominates at temperature between 1241K (968˚C) and 1323K (1050˚C). At strain rates above 0.001/s, a combination of superplastic and power-law creep deformation mechanisms is evident. At the highest strain rates, power-law creep deformation dominates. Using experimental evidence along with previous studies, constitutive models of deformation mechanisms and microstructure evolution during high temperature compression are proposed. The proposed models predict the boundaries of deformation mechanisms along with the material response to imposed deformation conditions such as superplasticity-enhanced grain growth and dynamic recrystallization.Ph.D.Materials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/77834/1/wenjtu_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/77834/2/wenjtu_1.pd

Transport properties of dense deuterium-tritium plasmas

Consistent descriptions of the equation of states, and information about transport coefficients of deuterium-tritium mixture are demonstrated through quantum molecular dynamic (QMD) simulations (up to a density of 600 g/cm$^{3}$ and a temperature of $10^{4}$ eV). Diffusion coefficients and viscosity are compared with one component plasma model in different regimes from the strong coupled to the kinetic one. Electronic and radiative transport coefficients, which are compared with models currently used in hydrodynamic simulations of inertial confinement fusion, are evaluated up to 800 eV. The Lorentz number is also discussed from the highly degenerate to the intermediate region.Comment: 4 pages, 3 figure

Psychological Effects of False-Positive Results in Expanded Newborn Screening in China

Objectives: As more families participate expanded newborn screening for metabolic disorders in China, the overall number of false positives increases. Our goal was to assess the potential impact on parental stress, perceptions of the child’s health, and family relationships. Methods: Parents of 49 infants with false-positive screening results for metabolic disorders in the expanded newborn screening panel were compared with parents of 42 children with normal screening results. Parents first completed structured interview using likert scales, closed and open questions. Parents also completed the parenting stress index. Results: A total of 88 mothers and 41 fathers were interviewed. More mothers in the false-positive group reported that their children required extra parental care (21%), compared with 5 % of mothers in the normal-screened group (P,0.001). 39 % of mothers in the false-positive group reported that they worry about their child’s future development, compared with 10 % of mothers in the normal-screened group (P,0.001). Fathers in the false-positive group did not differ from fathers in the normal-screened group in reporting worry about their child’s extra care requirements, and their child’s future development. Children with false-positive results compared with children with normal results were triple as likely to experience hospitalization (27%vs 9%, respectively; P,0.001). Conclusions: The results showing false-positive screening results may affect parental stress and the parent-chil

The Effects of Modified Simiao Decoction in the Treatment of Gouty Arthritis: A Systematic Review and Meta-Analysis

The modified Simiao decoctions (MSD) have been wildly applied in the treatment of gouty arthritis in China. However, the evidence needs to be evaluated by a systematic review and meta-analysis. After filtering, twenty-four randomised, controlled trials (RCTs) comparing the effects of MSD and anti-inflammation medications and/or urate-lowering therapies in patients with gouty arthritis were included. In comparison with anti-inflammation medications, urate-lowering therapies, or coadministration of anti-inflammation medications and urate-lowering therapies, MSD monotherapy significantly lowered serum uric acid (p<0.00001, mean difference = −90.62, and 95% CI [−128.38, −52.86]; p<0.00001, mean difference = −91.43, and 95% CI [−122.38, −60.49]; p=0.02, mean difference = −40.30, and 95% CI [−74.24, −6.36], resp.). Compared with anti-inflammation medications and/or urate-lowering therapies, MSD monotherapy significantly decreased ESR (p<0.00001; mean difference = −8.11; 95% CI [−12.53, −3.69]) and CRP (p=0.03; mean difference = −3.21; 95% CI [−6.07, −0.36]). Additionally, the adverse effects (AEs) of MSD were fewer (p<0.00001; OR = 0.08; 95% CI [0.05, 0.16]). MSD are effective in the treatment of gouty arthritis through anti-inflammation and lowering urate. However, the efficacy of MSD should be estimated with more RCTs

Impact of multimorbidity count on all-cause mortality and glycaemic outcomes in people with type 2 diabetes: a systematic review protocol

Introduction: Type 2 diabetes (T2D) is a leading health priority worldwide. Multimorbidity (MM) is a term describing the co-occurrence of two or more chronic diseases or conditions. The majority of people living with T2D have MM. The relationship between MM and mortality and glycaemia in people with T2D is not clear. Methods and analysis: Medline, Embase, Cumulative Index of Nursing and Allied Health Complete, The Cochrane Library, and SCOPUS will be searched with a prespecified search strategy. The searches will be limited to quantitative empirical studies in English with no restriction on publication date. One reviewer will perform title screening and two review authors will independently screen the abstract and full texts using Covidence software, with disagreements adjudicated by a third reviewer. Data will be extracted using a using a Population, Exposure, Comparator and Outcomes framework. Two reviewers will independently extract data and undertake the risk of bias (quality) assessment. Disagreements will be resolved by consensus. A narrative synthesis of the results will be conducted and meta-analysis considered if appropriate. Quality appraisal will be undertaken using the Newcastle-Ottawa quality assessment scale and the quality of the cumulative evidence of the included studies will be assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. This protocol was prepared in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines to ensure the quality of our review. Ethics and dissemination: This review will synthesise the existing evidence about the impact of MM on mortality and glycaemic outcomes in people living with T2D and increase our understanding of this subject and will inform future practice and policy. Findings will be disseminated via conference presentations, social media and peer-reviewed publication

Anti-trypanosomal effect of Malva sylvestris (Malvaceae) extract on a Trypanosoma brucei brucei-infected mouse model of sleeping sickness

Purpose: To evaluate the antitrypanosomal activity of Malva sylvestris (MS) extract in a Trypanosoma brucei brucei-infected  mouse model of sleeping sickness.Methods: Sleeping sickness was induced by the intraperitoneal injection of Trypanosoma brucei brucei infected blood in mice.  Confirmation of parasitaemia was performed by estimating the parasite count in the plasma on the 12th day after inoculation. All the mice were divided into five groups: control group that received neither infection nor treatment; negative control that was  infected with the parasite but did not receive treatment; MS-treated group that receive MS extract (250 and 500 mg/kg, ip) and standard (STD) group that received levamisole (7.5 mg/kg, ip) for 7 days after the development of parasitaemia. A further parasite count was performed in the blood and cerebrospinal fluid (CSF) after the treatment period. Humoral antibody response,  delayed hypersensitivity reaction, and mobilization of leucocytes were determined after the treatment period in SRBC-sensitized mice.Results: The results indicate that treatment with MS significantly decreased body weight and parasite count in the blood and CSF of mice with Trypanosoma brucei brucei-induced sleeping sickness compared with that in the negative control group. There was a significant increase in paw swelling and decrease in secondary antibody in the MS-treated group compared with that in the  negative control group. However, treatment with MS extract also enhanced the mobilization of the total leucocyte count compared with that in the negative control group.Conclusion: The results demonstrate the anti-trypanosomal activity of Malva sylvestris extract via immunomodulation in a  Trypanosoma brucei brucei-infected mouse model of sleeping sickness.Keywords: Malva sylvestris, Trypanosoma brucei brucei, Sleeping sickness, Immunomodulatory activity, Delayed hypersensitivity reactio

Valuation impacts of environmental protection taxes and regulatory costs in heavy-polluting industries

In 2016, the issue of the Environmental Protection Tax Law indicated the enhancement of environmental protection in China. This study examines the market reaction to firms in heavy-polluting industries, and the effects of external legal institutional quality and internal environmental disclosure on firm value around the passage of Environmental Protection Tax Law. Using an event study approach coupled with ordinary least square regressions, the researchers find a significantly negative market reaction to firms in heavy-polluting industries, but this negative reaction varies depending on the expected increase in future regulatory costs. Specifically, the above negative reaction is stronger when the firm reveals that itself or its subsidiary belongs to heavy-polluting industry, however it would be mitigated when a firm is in a region with better quality of legal institutions or discloses environmental improvement activities. Overall, the results are consistent with the market perceiving that the environmental protection tax law enacted would increase regulatory costs for firms in heavy-polluting industries, and also show the higher-quality regional legal institutions and more efforts on environmental protection could relieve the market’s pessimism caused by uncertainty