1,721,367 research outputs found
Corrosion Behaviour of a Superduplex Stainless Steel in Chloride Aqueous Solution
No full textSuper duplex stainless steels (SDSS) have been widely used as structural materials for chemical plants (especially in those engaged in phosphoric acid production), in the hydrometallurgy industries, and as materials for offshore applications due to their excellent corrosion resistance in chloride environments, compared with other commercial types of ferritic stainless steels. These alloys also possess superior weld-ability and better mechanical properties than austenitic stainless steels. However, due to their two-phase structure, the nature of which is very dependent on their composition and thermal history, the behavior of SDSS regarding localized corrosion appears difficult to predict, especially in chloride environments. To improve their final properties, the effect of the partition of the alloying elements between the two phases, and the composition and microstructure of each phase are the key to understanding the localized corrosion phenomena of SDSS. This paper concerns the effects of the SDSS microstructure and heat treatment on the SDSS corrosion resistance in aqueous solutions, containing different amounts of NaCl at room temperature
Surface hardening od Ti-6Al-4V alloy using combined electroless Ni-B plating and diffusion treatments
No full textThe electroless plating process allows the production of a nickel-boron coating on the surface of a Ti-6Al-4V alloy, by immersion in a nickel chloride aqueous solution using dimethylamine borane (DMAB) as a reducing agent. A series of diffusion treatments was carried out at temperatures ranging from 400 to 900°C in order to achieve deep case hardening. The characterisation of both the electroless coating and the diffusion treated alloy was performed using XRD, SEM, EDS, and glow discharge optical spectrometry (GDOS). Microhardness and compositional profiles were carried out in order to reveal the hardening effect and the nickel and boron penetration. The results showed that a significant improvement in the hardness can be achieved by choosing the correct treatment parameters. Surface hardnesses up to 850 HV and a depth of hardening larger than 500 μm were achieved at 900°C in an inert atmosphere
Obesity and Chronic Inflammation: Implications for Rheumatoid Arthritis, Spondyloarthritis, and Ulcerative Colitis
No full textBackground: Immune-mediated inflammatory diseases (IMIDs) are a group of chronic conditions characterized by dysregulated immune responses and persistent inflammation. Rheumatoid arthritis (RA), spondyloarthritis (SpA), and ulcerative colitis (UC) exemplify prominent IMIDs, each presenting unique challenges for their management, that impact patient's quality of life (QoL). Obesity, marked by persistent low-grade inflammation, influences the progression, response to treatment, and clinical management of patients with RA, SpA, and UC. Besides, the emerging role of sarcopenic obesity, a special subtype of obesity with malnutrition, should be considered in the definition of the appropriated therapeutic interventions. Methods: This narrative literature review summarizes recent evidence on the interplay between obesity-induced inflammation and IMIDs. Results: Obesity contributes to elevated levels of proinflammatory cytokines, influencing the inflammatory pathways common to IMIDs. White adipose tissue, acting as an endocrine organ, produces cytokines like TNF-α and IL-6, fueling chronic inflammation. The dysregulation of adipokines, such as leptin and adiponectin, further complicates this interplay, impacting immune responses and metabolic processes. Conclusions: Understanding the cross-talk between inflammatory pathways in obesity and IMIDs can provide insight into potential targets for intervention. This includes lifestyle modifications aimed to regulate weight gain, paving the way for comprehensive strategies to manage IMIDs in the context of obesity
Electron beam trajectory and optics control in the ELI-NP Gamma Beam System
No full textMagnetic field errors and misalignments of magnetic and diagnostic components induce spurious emittance growth. The aim of this study is to correct the impact of such errors on the ELI-NP Gamma Beam System low energy line for an effective commissioning of the machine. To perform this study we use the simulation code , for alignment and trajectory stabilization methods such as one-to-one steering, fast-trajectory-feedback (FTF) or global method and Dispersion Free Steering (DFS). We show the latter to be the most robust trajectory control method for magnetic elements and monitor errors
A SW Ka-Band linearizer structure with minimum surface electric field for the compact light XLS project
No full textThere is a strong demand for accelerating structures able to achieve higher gradients and more compact dimensions for the next generation of linear accelerators for research, industrial and medical applications. In the framework of the Compact Light XLS project, an ultra-high gradient higher harmonic RF accelerating structure is needed for the linearization of the longitudinal phase space. In order to determine the maximum sustainable gradients in normal conducting RF powered particle beam accelerators with extremely low probability of RF breakdown, investigations are in progress for using short accelerating structures in the Ka-band regime. We here report an electromagnetic design of a compact linearizer standing wave (SW) accelerating structure. The cavity has a length of about 8 cm and operates on the π-mode at 35.982 GHz, which is the third harmonic with respect to the Linac frequency (11.994 GHz). The accelerating gradient is 100 MV/m and the cavity geometry is optimized in order to minimize the surface peak electric field
A novel exact analytical expression for the magnetic field of a solenoid
No full textIn this paper we present the analytical calculations to derive the magnetic field of a solenoid by solving exactly a fractional integral with the use of a novel method. Starting from the Biot-Savart law, we consider a coil of negligible thickness with a stationary electric current. We derive the expressions of the on- and off-axes magnetic field components. The results have been compared to some simplified and known analytical formulae as well as to a commercial numerical code showing a good agreement
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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