Monitoring Single-point Dressers Using Fuzzy Models

AbstractGrinding causes progressive dulling and glazing of the grinding wheel grains and clogging of the voids on the wheel's surface with ground metal dust particles, which gradually increases the grinding forces. The condition of the grains at the periphery of a grinding wheel strongly influences the damage induced in a ground workpiece. Therefore, truing and dressing must be carried out frequently. Dressing is the process of conditioning the grinding wheel surface to reshape the wheel when it has lost its original shape through wear, giving the tool its original condition of efficiency. Despite the very broad range of dressing tools available today, the single-point diamond dresser is still the most widely used dressing tool due to its great versatility. The aim of this work is to predict the wear level of the single-point dresser based on acoustic emission and vibration signals used as input variables for fuzzy models. Experimental tests were performed with synthetic diamond dressers on a surface-grinding machine equipped with an aluminum oxide grinding wheel. Acoustic emission and vibration sensors were attached to the tool holder and the signals were captured at 2MHz. During the tests, the wear of the diamond tip was measured every 20 passes using a microscope with 10 to 100 X magnification. A study was conducted of the frequency content of the signals, choosing the frequency bands that best correlate with the diamond's wear. Digital band-pass filters were applied to the raw signals, after which two statistics were calculated to serve as the inputs for the fuzzy models. The results indicate that the fuzzy models using the aforementioned signal statistics are highly effective for predicting the wear level of the dresser

Carvões portugueses: A revalorização moderna possível de um recurso geológico. O caso-de-estudo da Bacia Carbonífera do Douro

Na sequência de uma síntese sobre as formações datadas do Carbonífero presentes na Bacia Carbonífera do Douro e seu enquadramento geológico, os autores descrevem os estudos modernos, nomeadamente no domínio da estratigrafia efectuados na bacia. Após o fecho das minas de metantracites da bacia (1972 na área do Couto Mineiro de São Pedro da Cova e 1994 na área do Couto Mineiro do Pejão) desenvolveram-se outros importantes estudos, designadamente na área do Couto Mineiro do Pejão, relacionados com o fim da actividade mineira, nomeadamente nos domínios de subsidência mineira e afluxos de água e seus aspectos geológicos e hidrogeomecânicos, estudos estes de que se dá igualmente relato no presente trabalho. Por fim, apresenta-se o essencial do Projecto-Piloto COSEQ elaborado com vista a definir a possível revalorização, em termos modernos, das metantracites da Bacia Carbonífera do Douro como potencial meio de sequestração geológica de CO2. Com efeito, os carvões durienses constituem, hoje, um recurso geológico abandonado do ponto de vista mineiro tradicional.A review of the Carboniferous formations and the geological settings of the Douro Coalfield (NW, Portugal) are presented, followed by a summary of the advances introduced by recent stratigraphic studies. After the closure of the collieries in the Douro Coalfield (in 1972 the S.Pedro da Cova mining area, and in 1994 the Pejão mining area) important studies related to mine closure were conducted, mainly concerned with mining subsidence and groundwater pathways, as well as, related geological and hydrogeomechanical features. These studies were also summarized in the present work. Finally, the authors present the main features of the COSEQ Pilot-Project, developed to assess the viability of the Douro meta-anthracites for CO2 geological sequestration, and in so doing enhancing the value of this Coalfield in a modern day context, given that the Douro coals are currently a geological resource abandoned in terms of traditional mining.info:eu-repo/semantics/publishedVersio

Decline in Circulating Tumor Cell Count and treatment outcome in advanced prostate cancer

AbstractBackgroundTreatment response biomarkers are urgently needed for castration-resistant prostate cancer (CRPC). Baseline and post-treatment circulating tumor cell (CTC) counts of ≥5 cells/7.5ml are associated with poor CRPC outcome.ObjectiveTo determine the value of a ≥30% CTC decline as a treatment response indicator.Design, setting, and participantsWe identified patients with a baseline CTC count ≥5 cells/7.5ml and evaluable post-treatment CTC counts in two prospective trials.InterventionPatients were treated in the COU-AA-301 (abiraterone after chemotherapy) and IMMC-38 (chemotherapy) trials.Outcome measures and statistical analysisThe association between a ≥30% CTC decline after treatment and survival was evaluated using univariable and multivariable Cox regression models at three landmark time points (4, 8, and 12 wk). Model performance was evaluated by calculating the area under the receiver operating characteristic curve (AUC) and c-indices.ResultsOverall 486 patients (122 in IMMC-38 and 364 in COU-AA-301) had a CTC count ≥5 cells/7.5ml at baseline, with 440, 380, and 351 patients evaluable at 4, 8, and 12 wk, respectively. A 30% CTC decline was associated with increased survival at 4 wk (hazard ratio [HR] 0.45, 95% confidence interval [CI] 0.36–0.56; p<0.001), 8 wk (HR 0.41, 95% CI 0.33–0.53; p<0.001), and 12 wk (HR 0.39, 95% CI 0.3–0.5; p<0.001) in univariable and multivariable analyses. Stable CTC count (<30% fall or <30% increase) was not associated with a survival benefit when compared with increased CTC count. The association between a 30% CTC decline after treatment and survival was independent of baseline CTC count. CTC declines significantly improved the AUC at all time-points. Finally, in the COU-AA-301 trial, patients with CTC ≥5 cells/7.5ml and a 30% CTC decline had similar overall survival in both arms.ConclusionsA 30% CTC decline after treatment from an initial count ≥5 cells/7.5ml is independently associated with CRPC overall survival following abiraterone and chemotherapy, improving the performance of a multivariable model as early as 4 wk after treatment. This potential surrogate must now be prospectively evaluated.Patient summaryCirculating tumor cells (CTCs) are cancer cells that can be detected in the blood of prostate cancer patients. We analyzed changes in CTCs after treatment with abiraterone and chemotherapy in two large clinical trials, and found that patients who have a decline in CTC count have a better survival outcome

Cytosolic p120-catenin regulates growth of metastatic lobular carcinoma through Rock1-mediated anoikis resistance

Metastatic breast cancer is the major cause of cancer-related death among women in the Western world. Invasive carcinoma cells are able to counteract apoptotic signals in the absence of anchorage, enabling cell survival during invasion and dissemination. Although loss of E-cadherin is a cardinal event in the development and progression of invasive lobular carcinoma (ILC), little is known about the underlying mechanisms that govern these processes. Using a mouse model of human ILC, we show here that cytosolic p120-catenin (p120) regulates tumor growth upon loss of E-cadherin through the induction of anoikis resistance. p120 conferred anchorage independence by indirect activation of Rho/Rock signaling through interaction and inhibition of myosin phosphatase Rho–interacting protein (Mrip), an antagonist of Rho/Rock function. Consistent with these data, primary human ILC samples expressed hallmarks of active Rock signaling, and Rock controlled the anoikis resistance of human ILC cells. Thus, we have linked loss of E-cadherin — an initiating event in ILC development — to Rho/Rock-mediated control of anchorage-independent survival. Because activation of Rho and Rock are strongly linked to cancer progression and are susceptible to pharmacological inhibition, these insights may have clinical implications for the development of tailor-made intervention strategies to better treat invasive and metastatic lobular breast cancer