Tool wear monitoring using neuro-fuzzy techniques: a comparative study in a turning process

Tool wear detection is a key issue for tool condition monitoring. The maximization of useful tool life is frequently related with the optimization of machining processes. This paper presents two model-based approaches for tool wear monitoring on the basis of neuro-fuzzy techniques. The use of a neuro-fuzzy hybridization to design a tool wear monitoring system is aiming at exploiting the synergy of neural networks and fuzzy logic, by combining human reasoning with learning and connectionist structure. The turning process that is a well-known machining process is selected for this case study. A four-input (i.e., time, cutting forces, vibrations and acoustic emissions signals) single-output (tool wear rate) model is designed and implemented on the basis of three neuro-fuzzy approaches (inductive, transductive and evolving neuro-fuzzy systems). The tool wear model is then used for monitoring the turning process. The comparative study demonstrates that the transductive neuro-fuzzy model provides better error-based performance indices for detecting tool wear than the inductive neuro-fuzzy model and than the evolving neuro-fuzzy model

Lack of an Antibacterial Response Defect in Drosophila Toll-9 Mutant

Toll and Toll-like receptors represent families of receptors involved in mediating innate immunity response in insects and mammals. Although Drosophila proteome contains multiple Toll paralogs, Toll-1 is, so far, the only receptor to which an immune role has been attributed. In contrast, every single mammalian TLR is a key membrane receptor upstream of the vertebrate immune signaling cascades. The prevailing view is that TLR-mediated immunity is ancient. Structural analysis reveals that Drosophila Toll-9 is the most closely related to vertebrate TLRs and utilizes similar signaling components as Toll-1. This suggests that Toll-9 could be an ancestor of TLR-like receptors and could have immune function. Consistently, it has been reported that over-expression of Toll-9 in immune tissues is sufficient to induce the expression of some antimicrobial peptides in flies. These results have led to the idea that Toll-9 could be a constitutively active receptor that maintain significant levels of antimicrobial molecules and therefore provide constant basal protection against micro-organisms. To test theses hypotheses, we generated and analyzed phenotypes associated with a complete loss-of-function allele of Toll-9. Our results suggest that Toll-9 is neither required to maintain a basal anti-microbial response nor to mount an efficient immune response to bacterial infection

Differential roles of the Drosophila EMT-inducing transcription factors Snail and Serpent in driving primary tumour growth.

Several transcription factors have been identified that activate an epithelial-to-mesenchymal transition (EMT), which endows cells with the capacity to break through basement membranes and migrate away from their site of origin. A key program in development, in recent years it has been shown to be a crucial driver of tumour invasion and metastasis. However, several of these EMT-inducing transcription factors are often expressed long before the initiation of the invasion-metastasis cascade as well as in non-invasive tumours. Increasing evidence suggests that they may promote primary tumour growth, but their precise role in this process remains to be elucidated. To investigate this issue we have focused our studies on two Drosophila transcription factors, the classic EMT inducer Snail and the Drosophila orthologue of hGATAs4/6, Serpent, which drives an alternative mechanism of EMT; both Snail and GATA are specifically expressed in a number of human cancers, particularly at the invasive front and in metastasis. Thus, we recreated conditions of Snail and of Serpent high expression in the fly imaginal wing disc and analysed their effect. While either Snail or Serpent induced a profound loss of epithelial polarity and tissue organisation, Serpent but not Snail also induced an increase in the size of wing discs. Furthermore, the Serpent-induced tumour-like tissues were able to grow extensively when transplanted into the abdomen of adult hosts. We found the differences between Snail and Serpent to correlate with the genetic program they elicit; while activation of either results in an increase in the expression of Yorki target genes, Serpent additionally activates the Ras signalling pathway. These results provide insight into how transcription factors that induce EMT can also promote primary tumour growth, and how in some cases such as GATA factors a ‘multi hit’ effect may be achieved through the aberrant activation of just a single gene

RNA-sequencing elucidates the regulation of behavioural transitions associated with mating in honey bee queens

This study was funded by a BBSRC ISIS grant BB/J019453/1, a Royal Holloway Research Strategy Fund Grant, and a Leverhulme Grant F/07537/AK to MJFB. BPO was supported by Australian Research Council Discovery grants DP150100151 and DP120101915. FM was supported by a Marie Curie International Incoming Fellowship FP7-PEOPLE-2013-IIF-625487 to MJFB. We would like to thank Dave Galbraight (Penn State) and Alberto Paccanaro (RHUL) for support with analysis of RNAseq data and four anonymous reviewers for providing thoughtful insights that helped to improve the manuscript.Peer reviewedPublisher PD

Modelling and experimental investigation of spindle and cutter dynamics for a high-precision machining center

The geometric quality of high-precision parts is highly dependent on the dynamic performance of the entire machining system, which is determined by the interrelated dynamics of machine tool mechanical structure and cutting process. This performance is of great importance in advanced, high-precision manufacturing processes, including aerospace and biomedical applications. In this paper, the dynamics of the combined spindle/cutter system, a major component of any machine tool, is identified using impact testing techniques and is successfully approximated by a second-order linear model. Results of computer simulations of machining processes that include the identified spindle/cutter dynamics show a significant influence on the quality of the final product. From this, it is concluded that, for precision workpieces, the dynamics of the spindle and cutter system will have to be taken into account in order to improve future machining controls and processes.Peer reviewed: YesNRC publication: Ye

Distributed monitoring and control of machines and machine conditions

Peer reviewed: YesNRC publication: Ye

Cleaning oil paintings: NMR relaxometry and SPME to evaluate the effects of green solvents and innovative green gels

Gels have been recently introduced in conservation to better control the cleaning action. The slow solvent release is of utmost importance to selectively remove varnish layers of a few microns in thickness, applied on paint layers which may have similar chemical properties. To evaluate the interactions of the underlying paint with solvents, diagnostic methods should study the physical and chemical changes that occur during and after the treatment. In this paper, we propose an innovative analytical protocol based on the combination of solid phase microextraction (SPME) and nuclear magnetic resonance (NMR) relaxometry to evaluate solvent entry and retention in the paint layer, as well as the induced microscopic and macroscopic changes to the elasticity of the binder. Moreover, FTIR and optical microscopy are used to evaluate the cleaning efficacy. The proposed analytical protocol can be used to identify solvents or gels which show minimal interaction with the paint. In particular, we have tested the protocol to evaluate the performance of non-toxic and biodegradable green gels on mock-ups and on a painting dated 19th century showing that they perform better than solvents applied with swabs. Five-minute gel treatments were found to be as effective at varnish removal as thirty-second swab treatments following traditional cleaning methods. Cleaning with gels limits the mechanical stress, solvent entry and retention in the paint layer, and reduces the embrittlement due to lower mass transfer. An unusual "sandwich" system was used to avoid the retention of gel residues on the surface with the gels contained in two sheets of Japanese papers-one on top and the other at the bottom

Cleaning oil paintings: NMR relaxometry and SPME to evaluate the effects of green solvents and innovative green gels

Gels have been recently introduced in conservation to better control the cleaning action. The slow solvent release is of utmost importance to selectively remove varnish layers of a few microns in thickness, applied on paint layers which may have similar chemical properties. To evaluate the interactions of the underlying paint with solvents, diagnostic methods should study the physical and chemical changes that occur during and after the treatment. In this paper, we propose an innovative analytical protocol based on the combination of solid phase microextraction (SPME) and nuclear magnetic resonance (NMR) relaxometry to evaluate solvent entry and retention in the paint layer, as well as the induced microscopic and macroscopic changes to the elasticity of the binder. Moreover, FTIR and optical microscopy are used to evaluate the cleaning efficacy. The proposed analytical protocol can be used to identify solvents or gels which show minimal interaction with the paint. In particular, we have tested the protocol to evaluate the performance of non-toxic and biodegradable green gels on mock-ups and on a painting dated 19th century showing that they perform better than solvents applied with swabs. Five-minute gel treatments were found to be as effective at varnish removal as thirty-second swab treatments following traditional cleaning methods. Cleaning with gels limits the mechanical stress, solvent entry and retention in the paint layer, and reduces the embrittlement due to lower mass transfer. An unusual sandwich system was used to avoid the retention of gel residues on the surface with the gels contained in two sheets of Japanese papers - one on top and the other at the bottom