The Proper Use of Fibre-Optic Sensors to Monitor the Condition of the Steam Boiler Hanger Rods.

Fibre optic sensors with integrated Bragg gratings are widely used in the diagnostics of machinery and equipment. They achieved their popularity thanks to their relatively simple operating principles. In addition, they allow the continuous monitoring of several variable physical parameters of objects, such as strain or temperature change, which directly translates into immediate feedback regarding potential damage. However, despite the easy-to-understand operating principle, selecting a specific type for a particular application can be problematic. This article aims to present the process of selecting the optimal set of fibre-optic sensors with integrated Bragg grating, which can be used in the process of monitoring the stress state of hanger rods of an engineering object such as an industrial boiler. The hanger rods of such boilers require constant technical supervision; however, the current measurement methods do not provide an effective and non-invasive diagnostic method. Therefore, the authors have undertaken the task of developing a universal diagnostic strategy for hanger rods. To this end, they will present the results of an analysis of the applicability of FBGs, examples of the use of different types of sensors, their installation methods, and the technical capabilities of the equipment necessary to handle the signals recorded with these sensors. Exemplary results of strain measurements of a selected hanger rod performed by the traditional method used now and with a selected FBG fibre optic sensor will be presented. In conclusion, concrete technical suggestions will be presented to be implemented in the existing industrial facility during the next part of the study.

The Influence of the Grid Density of Measurement Points on Damage Detection in an Isotropic Plate by the Use of Elastic Waves and Laser Scanning Doppler Vibrometry.

Damage detection in structural components, especially in mechanical engineering, is an important element of engineering practice. There are many methods of damage detection, in which changes in various parameters caused by the presence of damage are analysed. Recently, methods based on the analysis of changes in dynamic parameters of structures, that is, frequencies or mode shapes of natural vibrations, as well as changes in propagating elastic waves, have been developed at the highest rate. Diagnostic methods based on the elastic wave propagation phenomenon are becoming more and more popular, therefore it is worth focusing on the improvement of the efficiency of these methods. Hence, a question arises about whether it is possible to shorten the required measurement time without affecting the sensitivity of the diagnostic method used. This paper discusses the results of research carried out by the authors in this regard both numerically and experimentally. The numerical analysis has been carried out by the use of the Time-domain Spectral Finite Element Method (TD-SFEM), whereas the experimental part has been based on the measurement performed by 1-D Laser Doppler Scanning Vibrometery (LDSV).

Success rates and outcomes of laparoscopic mesh sacrohysteropexy.

BACKGROUND: Uterovaginal prolapse is a prevalent gynaecological issue, which can have a negative impact on the quality of life of women. Hysterectomy and vaginal repair are conventional treatments to address apical prolapse; however, women are increasingly requesting uterine-preserving alternatives. AIMS: This study aimed to evaluate the impact of laparoscopic mesh sacrohysteropexy on symptomatic prolapse from an Australian experience. MATERIALS AND METHODS: This retrospective cohort study presents outcomes of 157 patients who underwent laparoscopic mesh sacrohysteropexy at a private practice in South Australia during 2007-2017. Primary outcome is the success rate according to the pelvic organ prolapse quantification (POP-Q) system. Secondary measures included complication rates and patients identified as having Stages III-IV prolapse and their outcomes. RESULTS: The median age was 58 years (27-86 years), median parity was 2 (0-6), and median body mass index was 26.8 (23-29.9). One hundred and thirty-four women had a laparoscopic hysteropexy and concurrent vaginal prolapse repair and four women had an isolated laparoscopic hysteropexy. The mean pre-operative point C was 0.60. The mean change from pre-operative point C to post-operative point C was 7.6 cm (P < 0.01). Of the 136 patients (98.6%) seen at post-operative 4-6 weeks, all had Stage 0 POP-Q scores. Prolapse recurrence was observed in 22 patients, while 116 patients remained cured at their last follow-up. Prolapse recurrence was associated with anterior vaginal mesh, previous prolapse surgery, pre-operative Stage III-IV disease and number of vaginal deliveries. CONCLUSIONS: Laparoscopic mesh sacrohysteropexy is an effective and safe procedure with a high success rate comparable to available international data.

Supported Ionic Liquid-Phase Materials (SILP) as a Multifunctional Group of Highly Stable Modifiers and Hardeners for Carbon and Flax Epoxy Composites.

This paper introduces a novel approach to enhance epoxy resin formulations by using SILP materials as multifunctional hardeners and fillers in composite structures reinforced with carbon and flax fibers. This study explores the integration of ionic liquids (ILs) onto a silica support structure, presenting various permutations involving silica selection, ionic liquid choice, and concentration. The focus of this study was to elucidate the influence of SILP on resin curing ability and the mechanical properties of the resulting composites. Detailed research was conducted, including Brunauer-Emmett-Teller analysis (BET) for SILP materials and curing characterization for epoxy resin formulations with different SILP materials. Furthermore, the mechanical properties of the obtained composites were determined by Scanning Electron Microscopy analysis (SEM) (the force at break, the maximum elongation at break, tensile strength, and modulus of elasticity). Through SILP incorporation, the mechanical properties of composites, including the modulus of elasticity and tensile strength, are substantially improved, a phenomenon akin to traditional filler effects. The findings highlight SILP materials as prospective candidates for concurrent hardening and filling roles within composites (through a single-step procedure, with prolonged storage stability and controlled processing conditions), particularly pertinent as the composite industry veers toward epoxy bioresins necessitating liquefaction via temperature application.

Silicone polyether surfactant enhances bacterial cellulose synthesis and water holding capacity.

The versatility and unique properties of bacterial cellulose (BC) motivate research into enhancing its synthesis. Here a silicone polyether surfactant (SPS) was synthesized and tested as a non-nutritional additive to the cultivation media of Komagataeibacter xylinus. The addition of SPS to the Hestrin-Schramm (HS) medium resulted in a concentration-dependent decrease in surface tension from 59.57 ± 0.37 mN/m to 30.05 ± 0.41 mN/m (for 0.1% addition) that was correlated with an increased yield of BC, up to 37% wet mass for surfactant concentration close to its critical micelle concentration (0.008%). Physicochemical characterization of bacterial cellulose obtained in presence of SPS, showed that surfactant is not incorporated into BC structure and has a moderate effect on its crystallinity, thermal stability. Moreover, the water holding capacity was enhanced by over 40%. Importantly, obtained BC did not affect L929 murine fibroblast cell viability. We conclude that SPS provides an eco-friendly approach to increasing BC yield in static culture, enabling more widespread industrial and biomedical applications.

FEM-Based Wave Propagation Modelling for SHM: Certain Numerical Issues in 1D Structures.

The numerical modelling of structural elements is an important aspect of modern diagnostic systems. However, the process of numerical implementation requires advanced levels of consideration of multiple aspects. Important issues of that process are the positive and negative aspects of the methods applied. Therefore the aim of this article is to familiarise the reader with the most important aspects related to the process of numerical modelling of one-dimensional problems related to the phenomena of the propagation of elastic waves and their application for damage detection purposes.

High Body Mass Index is associated with an expansion of endometrial T Regulatory cell and macrophage populations.

Obesity is associated with implantation failure, miscarriage, low-grade inflammation and a reduction in peripheral immune-suppressive T regulatory (Treg) cells. Therefore, we postulated that this reduction may also extend to the endometrium and cause embryonic loss. In a cohort of 40 infertile women, without implantation failure or recurrent miscarriage, we examined the density of Treg cells, macrophages and natural killer (NK) cells in mid-luteal endometrial biopsies. Significant positive correlations were observed between BMI and endometrial Treg cells and macrophages, but no relationship with NK cells. We postulate that this change may be a positive adaption to minimise adiposity related inflammation.