Analytical prediction of laser mediated polymer melt and damage width

Far-field (remote) laser net-shape scanning has revolutionary potential across numerous applications which involve localized heating of materials. It offers a very high degree of manufacturing flexibility in concert with process repeatability, traceability and low cycle energy usage when compared to traditional tooling-based solutions if the material response can be accurately predicted. The functional mechanism of such processes is localized heating; in this work, an analytical model of the line width of phase change occurring between a 3mm thick virgin polypropylene, PP, sheet and a visually transparent 25μm thick PP film is presented. Validation of the model is provided empirically by the scanned application of a CO2 laser exhibiting a Gaussian beam profile onto reference materials at varying incident spot diameters, powers and traverse velocities. This work is of value for process parameter prediction, as this analytically based method is computationally light, enabling its real-time implementation in manufacturing environments

Temperature Measurement of Stored Biomass Using Low-frequency Acoustic Waves and Correlation Signal Processing Techniques

As a substitute of traditional fossil fuels, biomass is widely used to generate electricity and heat. The temperature of stored biomass needs to be monitored continuously to prevent the biomass from self-ignition. This paper proposes a non-intrusive method for the temperature measurement of stored biomass based on acoustic sensing techniques. A characteristic factor is introduced to obtain the sound speed in free space from the measured time of flight of acoustic waves in stored biomass. After analysing the relationship between the defined characteristic factor and air temperature, an updating procedure on the characteristic factor is proposed to reduce the influence of air temperature. By measuring the sound speed in free space air temperature is determined which is the same as biomass temperature. The proposed methodology is examined using a single path acoustic system which consists of a source and two sensors. A linear chirp signal with a duration of 0.1 s and frequencies of 200-500 Hz is generated and transmitted through stored biomass pellets. The time of flight of sound waves between the two acoustic sensors is measured through correlation signal processing. The relative error of measurement results using the proposed method is no more than 4.5% over the temperature range from 22? to 48.9?. Factors that affect the temperature measurement are investigated and quantified. The experimental results indicate that the proposed technique is effective for the temperature measurement of stored biomass with a maximum error of 1.5? under all test conditions

Neutrophil-fibroblast crosstalk drives immunofibrosis in Crohn’s disease through IFNα pathway

IntroductionCrohn’s disease (CD) is characterized by chronic inflammation and intestinal fibrosis leading to lifelong complications. However, the disease pathogenesis remains elusive, and the therapeutic options are limited. Here, we investigated the interaction between neutrophils and intestinal fibroblasts in the development of CD immunofibrosis, a disease mechanism predisposing to inflammatory and fibrotic complications.MethodsPeripheral neutrophils, enriched neutrophil extracellular traps (eNETs), serum, primary intestinal fibroblasts (PIFs) and intestinal biopsies from CD, ulcerative colitis (UC) patients, and healthy individuals (HI), were studied. Transcriptome analysis of neutrophils, multi-cytokine profiling and cell-based functional assays at mRNA/protein level were performed.ResultsCompared to UC, PIFs from CD patients, independently to the presence of strictures, displayed a distinct pro-fibrotic phenotype characterized by negative Krüppellike Factor-2 (KLF2) and increased cellular communication network factor-2 (CCN2) expression leading to collagen production. In both UC and CD, PIFs-derived IL-8 acted as a culprit chemoattractant for neutrophils in the intestine, where CD neutrophils were accumulated close to fibrotic lesions. Functionally, only CD neutrophils via eNETs induced a CD-like phenotype in HI PIFs, suggesting their fibrotic plasticity. High IFNa in serum and IFΝ-responsive signature in peripheral neutrophils were observed in CD, distinguishing it from UC. Moreover, CD serum stimulated the release of fibrogenic eNETs from neutrophils in an IFNa-dependent manner, suggesting the priming role of IFNa in circulating neutrophils. Inhibition of eNETs or JAK signaling in neutrophils or PIFs prevented the neutrophil-mediated fibrotic effect on PIFs. Furthermore, both serum IFNa levels and mRNA levels of key IFN signaling components in neutrophils were wellcorrelated with CD severity.ConclusionsThis study reveals the important role of the IFNa/neutrophil/fibroblast axis in CD immunofibrosis, suggesting candidate biomarkers and putative therapeutic targets