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P91 and P92 steels are widely used in power plants and petrochemical industry for long-term service components. Due to high resistance to creep, fatigue and corrosion, the use of grade 91 and grade 92 steels allows ultrasupercritical conditions (600 °C, 300 bar). To achieve this goal the alloy design was based on the following metallurgical concepts: stable tempered martensitic microstructure, precipitation strengthening through M23C6 (Cr, Fe, Mo or W carbides) and fine MX (V, Nb carbides), solution hardening through elements as Mo or Mo/W and high Cr content. This study is focused on the microstructure evolution of grade 91 and grade 92 steels under aging and creep conditions. Three sets of laboratory-aged specimens heated in oven at 550°C, 600°C and 650°C were examined. Furthermore, the influence of stress on the microstructure was evaluated. The microstructures were characterized by several means of investigations and the results were compared to literature. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Obesity is a multifactorial disease that is one of the major public health problems. It is the result of the interaction between behavioral, social and endocrine-metabolic components. Already in the 80s, it was highlighted by the World Health Organization (WHO) that the workplace is an ideal setting for introducing health promotion programs. The aim of the present study was to implement a health promotion program among healthcare workers (HCWs) operating in an Emergency Hospital in Southern Italy, combining diet, sports activity and motivational support over a 24-month period. PATIENTS AND METHODS: Participants were HCWs operating in an Emergency Hospital in Southern Italy. The inclusion criteria were as follows: overweight or obesity, i.e., body mass index (BMI) >25 kg/m2, or waist circumference >102 cm (males), >88 cm (females); dyslipidemia without pharmacological treatment, i.e., total cholesterol >220 mg/dL, or high-density lipoprotein (HDL) cholesterol <35 mg/dL, or low-density lipoprotein cholesterol (LDL) >130 mg/dL, or triglycerides >200 mg/dL; fasting glucose levels >120 mg/dl and/or reduced tolerance to glucose or diabetes mellitus, without pharmacological treatment was determined through HbA1c. RESULTS: The analysis was conducted on 36 participants. Follow-up was performed after twelve (T12) and twenty-four months (T24). The average systolic blood pressure (SBP) and diastolic blood pressure (DBP) values decreased during the time period. The average BMI of both male and female HCWs was significantly reduced from T0 to T12 and from T0 to T24. The triglyceride levels gradually decreased, but not significantly, from T0 to T24. The average blood glucose values decreased from T0 to T12 and from T12 to T24. The number of subjects who started to perform physical activity increased significantly between T0 and T12 and between T0 and T24. CONCLUSIONS: The findings have led to a significant change in HCWs' lifestyles and body perceptions, as well as their ability to work. [ABSTRACT FROM AUTHOR]

This paper presents an emerging market sourcing risk assessment and management model for sourcing components and sub-systems to emerging markets. The model was developed, tested and implemented by a US automotive manufacturer but the principles and tool discussed here are broadly applicable. We gathered a comprehensive list of risk factors through an intensive literature review and subject matter expert (SME) interviews. We used a process failure mode effect analysis (PFMEA) structure to characterize the risks and developed a simulation model to quantify risk factors in terms of dollars so that an OEM can evaluate risk mitigation strategies. The spreadsheet simulation ranks causes of failures and failure modes and calculates total risk in terms of dollars. In addition to analysing risk, the model evaluates the impact of different inventory levels on the costs of delays in the supply chain. The model can also be used to evaluate and select suppliers that offer minimum risk. We demonstrate the model with a real-world case study involving a North American auto company considering sourcing a component to an emerging market. [ABSTRACT FROM AUTHOR]

As part of a European research project, partially funded by the Steel Research Fund (RFS-CR-03049), the potential benefits derived from the use of synchronized tandem wire welding (STW) technology applied to structural plates, in place of the currently used arc techniques, have been evaluated. In particular, two welded joint types have been investigated: T joints and butt joints in S355 grade structural plate, 6 and 12 mm thick. Considering the variables that characterize the process, also depending on the type of tandem torch, i.e. variable or fixed electrode configuration, the influence of the distance between the electrodes, stick-out, the type of arc and weld speed on the process characteristics have been examined. The joints obtained have been compared with those produced using traditional technology in terms of overall joint deformation, structural integrity, microstructural analysis and mechanical performance (toughness and fatigue strength). The results have demonstrated that the STW process is an effective technology for increasing both the weld speed, at the same penetration and the quantity of metal deposited, by about 50% compared to GMAW welding, with only slightly higher but relatively modest heat input (1 kJ/mm). These operating conditions have allowed the preservation of a level of joint quality (EN ISO 5817 quality level B) and structural integrity, comparable with those of GMAW and SAW welded joints, in addition to significant reductions in distortion. Furthermore, the fatigue strength of STW joints has also been in compliance with the reference class (butt joint, FAT class 100). The objective of the project (RFS-CR-03049), partially supported by the Research Fund for Coal and Steel, was to explore and quantify the benefits of STW applied to structural steels as an alternative technology to established arc welding technologies. T joints and butt joints of 6 and 12 mm steel grade S355 plates have been investigated using two different types of welding gun configuration, i.e. fixed electrodes and variable electrodes configuration. The influence of electrodes distance, stick-out, arc types and welding speed have been examined. The optimized joints have been characterized in terms of structural integrity, microstructure, mechanical performance (impact fracture toughness and fatigue resistance), total deformation and compared to traditional arc welding joints. STW technology allowed an increase of about 50% in both the welding speed, at the same penetration and deposited metal compared to GMAW with a not much greater heat input (1 kJ/mm) maintaining the same level of joint quality (EN ISO 5817 quality level B) and structural integrity with a reduction of joint distortion. In addition, fatigue resistance of STW joints was in compliance with the requirement (FAT Class 100 MPa)[image omitted]. [ABSTRACT FROM AUTHOR]

The QT variability index (QTVI) indicates temporal dispersion in myocardial repolarization, and a high QTVI is associated with a propensity for sudden death from malignant ventricular arrhythmias in subjects at high risk. In this study, the authors assessed the effects of free breathing, controlled breathing, and sympathetic stress (tilt) on the QTVI in patients with chronic heart failure (CHF) and healthy control subjects. The authors also examined the influence of age on the same variables. To obtain normative data, they calculated 95% confidence intervals for healthy subjects grouped according to age. Under all experimental conditions, the QTVI was larger in the CHF group overall and in the age subsets than in controls. In patients and controls, the QTVI increased significantly during tilt, although no differences were found between the QTVI measured during free and controlled breathing. In healthy controls, the following variables correlated significantly with the QTVI: age and baseline heart rate (P < 0.001). In patients with CHF, aging had no influence on the QTVI. Conclusion: Age, sympathetic stress, and CHF all tend to increase the QTVI and could potentially induce sudden death. Further studies should assess the usefulness of the QTVI as a marker predicting sudden cardiac death under the various conditions of risk. [ABSTRACT FROM AUTHOR]

We present high-pressure x-ray photoelectron spectroscopy (HP-XPS) and first-principles kinetic Monte Carlo study addressing the nature of the active surface in CO oxidation over Pd(100). Simultaneously measuring the chemical composition at the surface and in the near-surface gas phase, we reveal both O-covered pristine Pd(100) and a surface oxide as stable, highly active phases in the near-ambient regime accessible to HP-XPS. Surprisingly, no adsorbed CO can be detected during high CO2 production rates, which can be explained by a combination of a remarkably short residence time of the CO molecule on the surface and mass-transfer limitations in the present setup. [ABSTRACT FROM AUTHOR]