Effect of temperature stress on main structure in waste incineration power generation plant

Waste incineration power station includes many functional structures, such as garbage discharge, storage, sorting and feeding units, boiler unit, tail gas treatment unit, leachate treatment unit, and coal storage unit. The structural forms of each part are different. Because of the particularity of garbage, structure units are required to be as close as possible and temperature joints should not be set up for the sake of possible leakage of exhaust gas or effluent liquor, so various structural units are integrated, which leads to the difficulty in structure design, and thermal stress cannot be neglected. In order to understand the effect temperature stress on main plant structures, a finite element model is established to study the distribution of thermal stress of the whole structure under three conditions: heating in summer, cooling in winter and heating in winter. It is found the influence of temperature on frame beam, column and steel space truss can be neglected, and the thermal stress on floor cannot be neglected [1]. The maximum stress is mainly distributed on both edges of floor along the longitude direction of structure. For those regions where stress concentration occurs, reinforcement bands or reinforcement mesh can be used to reduce the tensile stress. The analysis results show that this measure is effective and provides a reference for the design of the main structure of waste incineration power plant. This paper innovatively analyses the structure system of main workshop of refuse incineration power plant, which is composed of steel structure and concrete structure, and describes the skills and key points of complex system modeling. According to different seasons and heating temperature difference, the temperature stress on the surface of the structure is analyzed, which provides a reference for calculating degree stress and temperature difference of the similar structure system. The weak part of resistance to temperature stress in the structure system composed of concrete structure and steel structure is found out, and the corresponding solutions are put forward, which provides guidance for the construction of the main workshop of refuse incineration power station

Temperature stress of waste bunker in municipal solid waste incineration power generation plant

With large number of municipal solid waste incineration power generation plants appearing, serious environmental pollution will be caused if temperature cracks appear in waste bunkers. To reveal the interaction between the surrounding soil and bunker walls under the action of temperature, a finite element model is established. Considering the surrounding soil layer, the characteristics and influence laws of the interaction between the municipal solid waste bunker and the soil under different temperature conditions are studied. The simulation results show that the existence of the surrounding soil layer will affect the stress distribution, mainly at the bottom of the bunker and the surface of the bunker wall. Due to the thermal expansion and contraction, the municipal solid waste bunker is pressed during the heating process. In the process of cooling, there will be excessive tensile stress at the bottom of the bunker. To address this problem, expansion belt is arranged at the stress concentration portion to reduce the stress concentration. This measure proves to be effective according to analysis results, which provides a reference for the design of municipal solid waste bunkers

Liquefaction identification based on instantaneous H/V spectrum ratio

The strong vibration record contains a lot of information on the site during the earthquake, and the dynamic characteristics of the soil layer in the site can be expressed through this information. Currently, the H/V spectral ratio recorded by acceleration is often used to study the seismic effect of the site. Inspired by this, the thesis puts forward the idea of using the instantaneous H/V spectral ratio and its corresponding instantaneous frequency to judge the site liquefaction. The time-varying VARMA model is used to represent the horizontal ground motion component as the output of a time-varying system with vertical ground motion component as input. According to the time-varying VARMA parameters, the instantaneous spectral ratio, instantaneous frequency of the system and instantaneous damping ratio are used to judge the site liquefaction

Protocol for Physician wellbeing: an umbrella systematic review

Umbrella review of Systematic Review evidence relating to physician mental health and wellbeing

Indicated Prevention Interventions in the Workplace for Depressive Symptoms: A Systematic Review and Meta-analysis

Context: Depressive symptoms are highly prevalent and cause substantive morbidities and loss of functioning among employees. Depression may be prevented at its early stages. However, there is a paucity of information regarding indicated preventive interventions for depression among employees. The objective of this review is to examine the effectiveness of indicated interventions for the reduction of depressive symptoms in the workplace. Evidence acquisition: A systematic review and meta-analysis of articles published between January 2000 and September 2017 was conducted using major electronic databases, including PubMed/MEDLINE, PsycINFO, EMBASE, SOCINDEX, and ABI/ProQuest. Studies were selected based on a set of predefined inclusion criteria. Primary outcome measures were depressive symptomatology, and the interventions were preventive in nature. Studies were pooled based on the intervention type and the effect size was measured using the standardized mean difference. Evidence synthesis: A computer and hand search of the literature yielded 4,462 papers, from which 16 trials were identified to be suitable for meta-analysis. Eight of 16 studies reported significant effects for workplace preventive interventions targeting depressive symptoms in which six were cognitive behavioral therapy (CBT)-based interventions and two were non-CBT-based interventions. Small to medium effect sizes were found for both CBT- and non-CBT-based interventions (standardized mean difference= -0.44, 95% CI= -0.61, -0.26, I2=62.1% and standardized mean difference= -0.32, 95% CI= -0.59, -0.06, I2=58%, respectively). Conclusions: This review demonstrates that indicated interventions can significantly reduce the level of depressive symptoms among workers. The implementation of evidence-based workplace interventions should consequently be considered to prevent the development of depressive symptoms among employees

Imageological/Structural Study regarding the Improved Pharmacokinetics by ⁶⁸Ga-Labeled PEGylated PSMA Multimer in Prostate Cancer

PMSA (prostate-specific membrane antigen) is currently the most significant target for diagnosing and treating PCa (prostate cancer). Herein, we reported a series 68Ga/177Lu-labeled multimer PSMA tracer conjugating with PEG chain, including [68Ga]Ga-DOTA-(1P-PEG4), [68Ga]Ga-DOTA-(2P-PEG0), [68Ga]Ga-DOTA-(2P-PEG4), and [68Ga]Ga/[177Lu]Lu-DOTA-(2P-PEG4)2, which showed an advantage of a multivalent effect and PEGylation to achieve higher tumor accumulation and faster kidney clearance. To figure out how structural optimizations based on a PSMA multimer and PEGylation influence the probe’s tumor-targeting ability, biodistribution, and metabolism, we examined PSMA molecular probes’ affinities to PC-3 PIP (PSMA-highly-expressed PC-3 cell line), and conducted pharmacokinetics analysis, biodistribution detection, small animal PET/CT, and SPECT/CT imaging. The results showed that PEG4 and PSMA dimer optimizations enhanced the probes’ tumor-targeting ability in PC-3 PIP tumor-bearing mice models. Compared with the PSMA monomer, the PEGylated PSMA dimer reduced the elimination half-life in the blood and increased uptake in the tumor, and the biodistribution results were consistent with PET/CT imaging results. [68Ga]Ga-DOTA-(2P-PEG4)2 exhibited higher tumor-to-organ ratios. When labeled by lutetium-177, relatively high accumulation of DOTA-(2P-PEG4)2 was still detected in PC-3 PIP tumor-bearing mice models after 48 h, indicating its prolonged tumor retention time. Given the superiority in imaging, simple synthetic processes, and structural stability, DOTA-(2P-PEG4)2 is expected to be a promising tumor-targeting diagnostic molecular probe in future clinical practice

Application of metagenomic next-generation sequencing in the clinical diagnosis of infectious diseases after allo-HSCT: a single-center analysis

Abstract Background We investigated the value of metagenomic next-generation sequencing (mNGS) in diagnosing infectious diseases in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods Fifty-four patients who had fever following allo-HSCT from October 2019 to February 2022 were enrolled. Conventional microbiological tests (CMTs) and mNGS, along with imaging and clinical manifestations, were used to diagnose infection following allo-HSCT. The clinical diagnostic value of mNGS was evaluated. Results A total of 61 mNGS tests were performed, resulting in the diagnosis of 46 cases of infectious diseases. Among these cases, there were 22 cases of viral infection, 13 cases of fungal infection, and 11 cases of bacterial infection. Moreover, 27 cases (58.7%) were classified as bloodstream infections, 15 (32.6%) as respiratory infections, 2 (4.3%) as digestive system infections, and 2 (4.3%) as central nervous system infections. Additionally, there were 8 cases with non-infectious diseases (8/54, 14.81%), including 2 cases of interstitial pneumonia, 2 cases of bronchiolitis obliterans, 2 cases of engraftment syndrome, and 2 cases of acute graft-versus-host disease. The positive detection rates of mNGS and CMT were 88.9% and 33.3%, respectively, with significant differences (P < 0.001). The sensitivity of mNGS was 97.82%, the specificity was 25%, the positive predictive value was 93.75%, and the negative predictive value was 50%. Following treatment, 51 patients showed improvement, and 3 cases succumbed to multidrug-resistant bacterial infections. Conclusions mNGS plays an important role in the early clinical diagnosis of infectious diseases after allo-HSCT, which is not affected by immunosuppression status, empiric antibiotic therapy, and multi-microbial mixed infection

Identifying Tree Species in a Warm-Temperate Deciduous Forest by Combining Multi-Rotor and Fixed-Wing Unmanned Aerial Vehicles

Fixed-wing unmanned aerial vehicles (UAVs) and multi-rotor UAVs are widely utilized in large-area (>1 km2) environmental monitoring and small-area (2) fine vegetation surveys, respectively, having different characteristics in terms of flight cost, operational efficiency, and landing and take-off methods. However, large-area fine mapping in complex forest environments is still a challenge in UAV remote sensing. Here, we developed a method that combines a multi-rotor UAV and a fixed-wing UAV to solve this challenge at a low cost. Firstly, we acquired small-scale, multi-season ultra-high-resolution red-green-blue (RGB) images and large-area RGB images by a multi-rotor UAV and a fixed-wing UAV, respectively. Secondly, we combined the reference data of visual interpretation with the multi-rotor UAV images to construct a semantic segmentation model and used the model to expand the reference data. Finally, we classified fixed-wing UAV images using the large-area reference data combined with the semantic segmentation model and discuss the effects of different sizes. Our results show that combining multi-rotor and fixed-wing UAV imagery provides an accurate prediction of tree species. The model for fixed-wing images had an average F1 of 92.93%, with 92.00% for Quercus wutaishanica and 93.86% for Juglans mandshurica. The accuracy of the semantic segmentation model that uses a larger size shows a slight improvement, and the model has a greater impact on the accuracy of Quercus liaotungensis. The new method exploits the complementary characteristics of multi-rotor and fixed-wing UAVs to achieve fine mapping of large areas in complex environments. These results also highlight the potential of exploiting this synergy between multi-rotor UAVs and fixed-wing UAVs