A theta projection model for compressive creep behaviour of refractories at high temperature: application to alumina-spinel

Thermomechanical loads are normally applied to refractory materials throughout their service life whichever is their practical use (e.g. steel ladle, rotary kiln furnaces). Among all the phenomena that the refractories are exposed to, the influence of creep behaviour is essential in determining their performance. Creep of refractories is usually represented by simple creep laws such as Norton-Bailey, which lack the capacity for generalization. The theta projection creep method, on the other hand, was proposed in the twentieth century to predict the creep of metals and alloys across different temperatures and stresses. The model is represented by one exponential equation capable of representing the complete creep curve, and coefficients that are temperature and stress-dependent, thus enabling the representation of complex nonlinear creep behaviour. Since refractories have similar creep responses to metals, the theta projection creep model is validated to characterize the compressive creep behaviour of alumina-spinel refractories at temperatures between 1200 and 1500 °C. Creep data from steady-state and transient temperature creep tests are used to calibrate the model. A regression by the least square method is applied to calculate the model’s parameters. The model shows good flexibility in fitting the test data of the alumina-spinel refractory over the three creep stages. A temperature and stress dependence model is derived for the theta coefficients, reducing the number of material parameters necessary to describe the material's behaviour. The experimental creep curves are presented, as well as the curves resulting from the identified parameters. The implications of the chosen creep data set on the definition of the model and its adequacy for this novel application are discussed.This work was supported by the funding scheme of the European Commission, Marie SkłodowskaCurie Actions Innovative Training Networks in the frame of the project ATHOR—Advanced THermomechanical multi scale mOdelling of Refractory linings 764987 Grant. This work was partly fnanced by FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB / 04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020. The authors acknowledge the colleagues from Montanuniversitaet in Leoben, S. Samadi and D. Gruber for the meaningful discussions. The authors would like to thank the reviewer for the insightful comments and suggestions, and the valuable discussion proposed, which helped to improve the quality of the manuscrip

Road Pavement Damage Detection using Computer Vision Techniques: Approaches, Challenges and Opportunities

The work presented in this paper is the result of a preliminary research aimed at using computer vision techniques for road pavement damage detection in the context of a smart city. It first introduces the related concepts. Then, it surveys the state of the art and existing solutions, presenting their main features, strengths and limitations. The most promising solutions are identified. Finally, it discusses open challenges and research directions in this area

Insights into the role of fungi in Pine Wilt Disease

Pine wilt disease (PWD) is a complex disease that severely affects the biodiversity and economy of Eurasian coniferous forests. Three factors are described as the main elements of the disease: the pinewood nematode (PWN) Bursaphelenchus xylophilus, the insect‐vector Monochamus spp., and the host tree, mainly Pinus spp. Nonetheless, other microbial interactors have also been considered. The study of mycoflora in PWD dates back the late seventies. Culturomic studies have revealed diverse fungal communities associated with all PWD key players, composed frequently of saprophytic fungi (i.e., Aspergillus, Fusarium, Trichoderma) but also of necrotrophic pathogens associated with bark beetles, such as ophiostomatoid or blue‐stain fungi. In particular, the ophiostomatoid fungi often recovered from wilted pine trees or insect pupal chambers/tunnels, are considered crucial for nematode multiplication and distribution in the host tree. Naturally occurring mycoflora, reported as possible biocontrol agents of the nematode, are also discussed in this review. This review discloses the contrasting effects of fungal communities in PWD and highlights promising fungal species as sources of PWD biocontrol in the framework of sustainable pest management actions

New insights on biopolymer sterilization using supercritical co2 technology

info:eu-repo/semantics/draf

Advancements in on-line monitoring and control of parameters in knitting and sewing processes

This paper presents a summary of the developments in process control in textile processes at the University of Minho, by a multidisciplinary research group involving three different departments (Textile, lectronic and Mechanical Engineering). The studies target the automatic process parameter monitoring and control in the areas of industrial sewing and knitting.Fundação para a Ciência e a Tecnologia (FCT)

Bone morphogenetic protein 4 signaling regulates development of the anterior visceral endoderm in the mouse embryo

The extraembryonic ectoderm (ExE) of the mouse conceptus is known to play a role in embryo patterning by signaling to the underlying epiblast and surrounding visceral endoderm. Bmp4 is one of the key ExE signaling molecules and has been recently implicated to participate in regulating development and migration of the anterior visceral endoderm (AVE). However, it remains unclear when exactly BMP4 signaling starts to regulate AVE positioning. To examine this, we have chosen to affect BMP4 function at two different time points, at embryonic day 5.25 (E5.25), thus before AVE migration, and E5.75, just after AVE migration. To this end, an RNAi technique was used, which consisted of the injection of Bmp4 dsRNA into the proamniotic cavity of the egg cylinder followed by its targeted electroporation into the ExE. This resulted in specific knockdown of Bmp4. It was found that Bmp4 RNAi at E5.25, but not at E5.75, led to an abnormal pattern of expression of the AVE marker Cerberus‐like. Thus, BMP4 signaling appears to affect the expression of Cer1 at a specific time window. This RNAi approach provides a convenient means to study spatial and temporal function of genes shortly after embryo implantation

Fungal Communities of the Pine Wilt Disease Complex: Studying the Interaction of Ophiostomatales With Bursaphelenchus xylophilus

Original ResearchConsidered one of the most devastating plant–parasitic nematodes worldwide, Bursaphelenchus xylophilus (commonly known as pinewood nematode, PWN) is the causal agent of the pine wilt disease in the Eurasian coniferous forests. This migratory parasitic nematode is carried by an insect vector (Monochamus spp.) into the host tree (Pinus species), where it can feed on parenchymal cells and reproduce massively, resulting in the tree wilting. In declining trees, PWN populations are strongly dependent on fungal communities colonizing the host (predominantly ophiostomatoid fungi known to cause sapwood blue-staining, the blue-stain fungi), which not only influence their development and life cycle but also the number of individuals carried by the insect vector into a new host. Our main aim is to understand if PWN-associated mycobiota plays a key role in the development of PWD, in interaction with the PWN and the insect vector, and to what extent it can be targeted to disrupt the disease cycle. For this purpose, we characterized the fungal communities of Pinus pinaster trees infected and non-infected with PWN in three collection sites in Continental Portugal with different PWD temporal incidences. Our results showed that non-infected P. pinaster mycoflora is more diverse (in terms of abundance and fungal richness) than PWN-infected pine trees in the most recent PWD foci, as opposed to the fungal communities of long-term PWD history sites. Then, due to their ecological importance for PWN survival, representatives of the main ophiostomatoid fungi isolated (Ophiostoma, Leptographium, and Graphilbum) were characterized for their adaptative response to temperature, competition in-between taxa, and as food source for PWN. Under the conditions studied, Leptographium isolates showed promising results for PWN control. They could outcompete the other species, especially O. ips, and significantly reduce the development of PWN populations when compared to Botrytis cinerea (routinely used for PWN lab culturing), suggesting this to be a natural antagonist not only for the other blue-stain species but also for the PWNinfo:eu-repo/semantics/publishedVersio

Long-Lasting Novelty-Induced Neuronal Reverberation during Slow-Wave Sleep in Multiple Forebrain Areas

The discovery of experience-dependent brain reactivation during both slow-wave (SW) and rapid eye-movement (REM) sleep led to the notion that the consolidation of recently acquired memory traces requires neural replay during sleep. To date, however, several observations continue to undermine this hypothesis. To address some of these objections, we investigated the effects of a transient novel experience on the long-term evolution of ongoing neuronal activity in the rat forebrain. We observed that spatiotemporal patterns of neuronal ensemble activity originally produced by the tactile exploration of novel objects recurred for up to 48 h in the cerebral cortex, hippocampus, putamen, and thalamus. This novelty-induced recurrence was characterized by low but significant correlations values. Nearly identical results were found for neuronal activity sampled when animals were moving between objects without touching them. In contrast, negligible recurrence was observed for neuronal patterns obtained when animals explored a familiar environment. While the reverberation of past patterns of neuronal activity was strongest during SW sleep, waking was correlated with a decrease of neuronal reverberation. REM sleep showed more variable results across animals. In contrast with data from hippocampal place cells, we found no evidence of time compression or expansion of neuronal reverberation in any of the sampled forebrain areas. Our results indicate that persistent experience-dependent neuronal reverberation is a general property of multiple forebrain structures. It does not consist of an exact replay of previous activity, but instead it defines a mild and consistent bias towards salient neural ensemble firing patterns. These results are compatible with a slow and progressive process of memory consolidation, reflecting novelty-related neuronal ensemble relationships that seem to be context- rather than stimulus-specific. Based on our current and previous results, we propose that the two major phases of sleep play distinct and complementary roles in memory consolidation: pretranscriptional recall during SW sleep and transcriptional storage during REM sleep

Fungal communities of the Pine Wilt Disease Complex: Studying the Interaction of Ophiostomatales with Bursaphelenchus xylophilus

Considered one of the most devastating plant–parasitic nematodes worldwide, Bursaphelenchus xylophilus (commonly known as pinewood nematode, PWN) is the causal agent of the pine wilt disease in the Eurasian coniferous forests. This migratory parasitic nematode is carried by an insect vector (Monochamus spp.) into the host tree (Pinus species), where it can feed on parenchymal cells and reproduce massively, resulting in the tree wilting. In declining trees, PWN populations are strongly dependent on fungal communities colonizing the host (predominantly ophiostomatoid fungi known to cause sapwood blue-staining, the blue-stain fungi), which not only influence their development and life cycle but also the number of individuals carried by the insect vector into a new host. Our main aim is to understand if PWN-associated mycobiota plays a key role in the development of PWD, in interaction with the PWN and the insect vector, and to what extent it can be targeted to disrupt the disease cycle. For this purpose, we characterized the fungal communities of Pinus pinaster trees infected and non-infected with PWN in three collection sites in Continental Portugal with different PWD temporal incidences. Our results showed that non-infected P. pinaster mycoflora is more diverse (in terms of abundance and fungal richness) than PWN-infected pine trees in the most recent PWD foci, as opposed to the fungal communities of long-term PWD history sites. Then, due to their ecological importance for PWN survival, representatives of the main ophiostomatoid fungi isolated (Ophiostoma, Leptographium, and Graphilbum) were characterized for their adaptative response to temperature, competition in-between taxa, and as food source for PWN. Under the conditions studied, Leptographium isolates showed promising results for PWN control. They could outcompete the other species, especially O. ips, and significantly reduce the development of PWN populations when compared to Botrytis cinerea (routinely used for PWN lab culturing), suggesting this to be a natural antagonist not only for the other blue-stain species but also for the PWN

IL-22 controls iron-dependent nutritional immunity against systemic bacterial infections

This publication hasn't any creative commons license associated.This publication has a exclusive licensee of the American Association for the Advancement of Science.The deposited article contains attached the supplementary materials.Host immunity limits iron availability to pathogenic bacteria, but whether immunity limits pathogenic bacteria from accessing host heme, the major source of iron in the body, remains unclear. Using Citrobacter rodentium, a mouse enteric pathogen and Escherichia coli, a major cause of sepsis in humans as models, we find that interleukin-22, a cytokine best known for its ability to promote epithelial barrier function, also suppresses the systemic growth of bacteria by limiting iron availability to the pathogen. Using an unbiased proteomic approach to understand the mechanistic basis of IL-22 dependent iron retention in the host, we have identified that IL-22 induces the production of the plasma hemoglobin scavenger haptoglobin and heme scavenger hemopexin. Moreover, the anti-microbial effect of IL-22 depends on the induction of hemopexin expression, while haptogloblin is dispensable. Impaired pathogen clearance in infected Il22(-/-) mice was restored by administration and hemopexin-deficient mice had increased pathogen loads after infection. These studies reveal a previously unrecognized host defense mechanism regulated by IL-22 that relies on the induction of hemopexin to limit heme availability to bacteria leading to suppression of bacterial growth during systemic infections.Japan Society for the Promotion of Science fellowship; Kanae Foundation for the Promotion of Medical Science; Mishima Kaiun Memorial Foundation; Consejo Nacional de Ciencia y Tecnología of Mexico post-doctoral fellowship: (454848); NIH grants: (DK091191, DK095782); Fundação Calouste Gulbenkian;info:eu-repo/semantics/publishedVersio