Automated Experimental Modal Analysis of Bladed Wheels with an Anthropomorphic Robotic Station

Experimental modal analysis is challenging when the component has a highly three-dimensional shape, since a great number of measurement points are needed with accurate positioning. An anthropomorphic robotic station is proposed to automate this analysis, specifically on bladed wheels. This provides a reliable control of the spot location and of the beam orientation of a Laser Doppler Vibrometer. The modal frequencies were obtained along with the vibrational shapes and their spatial resolution was managed by exploiting the programming flexibility of the robotic station. The SAFE diagram was easily obtained by measuring a single point for each sector, and an extension of this diagram was demonstrated for the splitter blade wheels. The use of multiple measurement points, for each wheel sector, significantly improved the characterization of the modes having the same number of nodal diameters, hence the same shape coordinate on the SAFE diagram

A fretting fatigue setup for testing shrink-fit connections and experimental evidence of the strength enhancement induced by deep rolling

Fretting tests are usually performed on flat specimens with lateral contacting pads. The shrink-fitted connection, which experiences fretting at the edge of the contact, prompted the alternative use of a round-shaped specimen. This simplified the equipment and provided an accurate alignment between the fretting specimen and the external hub which plays the role of the pad. The deep rolling treatment can also be efficiently applied to a round shape, which would otherwise be difficult on the flat specimen geometry. After introducing this solution for fretting testing, the paper shows an experimental campaign on three shrink-fitted connections with different sizes and material combinations. There was a significant improvement in fretting fatigue strength, induced by the deep rolling, for all three specimen types. Finally, scanning electron microscopic analyses provided insights into the fretting fatigue nucleation mechanisms both for untreated and deep-rolled specimens

Modelling and Parameter Identification of Ex-Situ Biological Biogas Upgrading

In this paper, a model of ex-situ biological biogas upgrading process is first developed. Then, parameter sensitivity analysis is performed, in order to determine the most relevant parameters for subsequent parameter identification, based on a linear fractional transformation (LFT) reformulation of the model. Biogas composition and volumetric production have been well predicted by the calibrated model, allowing its adoption as a designing tool for start-up operation of experimental pilot-scale activity

Integral method coefficients for the ring-core technique to evaluate non-uniform residual stresses

The ring-core technique allows for the determination of non-uniform residual stresses from the surface up to relatively higher depths as compared to the hole-drilling technique. The integral method, which is usually applied to hole-drilling, can also be used for elaborating the results of the ring-core test since these two experimental techniques share the axisymmetric geometry and the 0°–45°–90° layout of the strain gage rosette. The aim of this article is to provide accurate coefficients which can be used for evaluating the residual stress distribution by the ring-core integral method. The coefficients have been obtained by elaborating the results of a very refined plane harmonic axisymmetric finite element model and verified with an independent three-dimensional model. The coefficients for small depth steps were initially provided, and then the values for multiple integer step depths were also derived by manipulating the high-resolution coefficient matrices, thus showing how the present results can be practically used for obtaining the residual stresses according to different depth sequences, even non-uniform. This analysis also allowed the evaluation of the eccentricity effect which turned out to be negligible due to the symmetry of the problem. An applicative example was reported in which the input of the experimentally measured relaxed strains was elaborated with different depth resolutions, and the obtained residual stress distributions were compared

Fatigue fracture surface investigations with a 3D optical profiler

In this paper a set of specimens, used for the critical distance determination, are investigated with a non-contact 3D optical profiler. The fatigue fracture surfaces of both plain and V-notched specimens, under axial (mode I) and torsional (mode III) loadings are observed, investigating steel 42CrMo4+QT and aluminium alloy 7075-T6. The fatigue fracture profiles are compared to be previously obtained critical distances, both for mode I and mode III. The stage I to stage II transition was found at a smaller size than the axial critical distance, for the steel, while for the torsional load a local plateau at the nucleation was observed. The fracture surface of the axial loading was instead much irregular at the scale of the mode I critical distance, for the aluminium alloy, resembling a not concluded stage I, while again a relatively flat surface was observed for the mode III loading

Short communication: Characterization of a monoclonal antibody for κ-casein B of cow's milk1

A monoclonal antibody (antik-B) against an oligopeptide of 23 AA corresponding to the region 131-153 of bovine kappa-casein (kappa-CN) B was generated using the Human Combinatorial Antibody Library (HuCAL) technology. Both AA substitutions distinguishing kappa-CN A and B are located in that region (positions 136 and 148). In this study, the reactivity of antik-B to milk samples collected from cows previously genotyped as CSN3*AA, CSN3*AB, and CSN3*BB was tested. According to Western blot results, antik-B recognized kappa-CN B and it showed no cross-reactivity toward kappa-CN A and other milk proteins. Furthermore, a modified Western blot method, urea-PAGE Western blot, was set up to assess the reactivity of antik-B toward all isoforms of kappa-CN B. In conclusion, antik-B was specific to kappa-CN B in milk and it seemed to be reactive toward all its isoforms

Tetracyclines in COVID-19 patients quarantined at home: Literature evidence supporting real-world data from a multicenter observational study targeting inflammatory and infectious dermatoses

Tetracyclines (TetraC) are widely used in dermatology for both inflammatory and infectious dermatoses; recently both in vivo and in vitro studies started to suggest also a potential antiviral effect. During COVID-19 outbreak, several dermatological patients contracted SARS-CoV-2 experiencing only mild symptoms, but no protocol were approved. A multicenter prospective observational study that enrolled COVID-19 patients visited with teledermatology and undergoing TetraC was performed. About 38 adult outpatients (M/F: 20/18, age 42.6 years [21-67]) were enrolled. During the TetraC treatment, symptoms resolved in all patients within 10 days. Remarkably, ageusia and anosmia disappeared in the first week of TetraC treatment. TetraC seem a promising drug to treat COVID-19 outpatients with mild symptoms

Varenicline and evaluated outcomes in smoking cessation programmes.

The morbidity and mortality rates attributed to smoking are substantial and cigarette smoke remains the first preventable cause of premature death worldwide. Despite the knowledge of the adverse consequences of smoking, many smokers struggle to quit. Cigarette smoking is the primary cause of chronic obstructive pulmonary disease, and smoking cessation represents the most effective way of stopping its progression. Varenicline is one of the first-line smoking cessation aids recommended in many Clinical Practice Guidelines and its efficacy and safety have been demonstrated in several clinical trials. Varenicline has a unique mechanism of action and clinical trials support its use as an effective and generally well-tolerated therapy. This article reviews the clinical pharmacological trials on smoking cessation published in recent years on varenicline, with particular attention to the outcomes used in the studies. MedLine, the Cochrane database and Embase were evaluated. Almost all the trials have, as a primary endpoint, the abstinence from cigarettes at 9-12 weeks of treatment. Only one study considers lung function spirometric changes as a secondary endpoint. No study has evaluated lung function. This marker could be very important as a way of evaluating, objectively, an improvement in lung function, which correlates also with subjective parameters, as dyspnea and fatigue

Role of nebulized glycopyrrolate in the treatment of chronic obstructive pulmonary disease

In the upcoming years, the proportion of elderly patients with chronic obstructive pulmonary disease (COPD) will increase, according to the progressively aging population and the increased efficacy of the pharmacological treatments, especially considering the management of chronic comorbidities. The issue to prescribe an appropriate inhalation therapy to COPD patients with significant handling or coordination difficulties represents a common clinical experience; in the latter case, the choice of an inadequate inhalation device may jeopardize the adherence to the treatment and eventually lead to its ineffectiveness. Treatment options that do not require particular timing for coordination between activation and/or inhalation or require high flow thresholds to be activated should represent the best treatment option for these patients. Nebulized bronchodilators, usually used only in acute conditions such as COPD exacerbations, could fulfill this gap, enabling an adequate drug administration during tidal breathing and without the need for patients\u2019 cooperation. However, so far, only short-acting muscarinic antagonists have been available for nebulization. Recently, a nebulized formulation of the inhaled long-acting muscarinic antagonist glycopyrrolate, delivered by means of a novel proprietary vibrating mesh nebulizer closed system (SUN-101/eFlow\uae), has progressed to Phase III trials and is currently in late-stage development as an option for maintenance treatment in COPD. The present critical review describes the current knowledge about the novel nebulizer technology, the efficacy, safety, and critical role of nebulized glycopyrrolate in patients with COPD. To this end, PubMed, ClinicalTrials.gov, Embase, and Cochrane Library have been searched for relevant papers. According to the available results, the efficacy and tolerability profile of nebulized glycopyrrolate may represent a valuable and dynamic treatment option for the chronic pharmacological management of patients with COPD