Alternative system to measure hydrogen content in molten aluminium using an electrochemical sensor

1037-1042The most reliable techniques for the direct measurement of hydrogen content in liquid aluminium are based on Sievert’s law or use electrochemical probes introduced directly in liquid aluminium. The main drawback of these methods is the high cost of the equipment. An alternative apparatus has been developed and tested. This equipment combines a widely used and much cheaper hydrogen electrochemical sensor with the procedure already patented and commonly used by gas recirculation techniques. The device has been constructed and calibrated using gaseous mixtures of known hydrogen content. For validation, the results obtained with this apparatus have been compared with hydrogen content measurements in liquid aluminium using the commercial Alscan equipment in an industrial facility. Experimental results suggest that the apparatus proposed in this work is capable of detecting hydrogen content in liquid aluminium obtaining measurements that are in a good agreement with those obtained using the commercial Alscan equipment. On the other hand, results also suggest that it is important to take into account the operating atmospheric pressure to correct the readings obtained from Alscan when operating at atmospheric pressure levels far from 1 atm

A Singleton Type-1 Fuzzy Logic Controller for On-Line Error Compensation During Robotic Welding

During robot welding operations in the manufacturing industry there is a need to modify on-line the welding path due to a mismatch in the position of the components to be welded. These positioning errors are due to multiple factors such as ageing of the components in the conveyor system, clamp fixtures, disturbances, etc. Therefore, robot reprogramming is needed which requires a stop in the production line and consequently an increment in production costs. This article is an extension of [1]a and presents an alternative solution to this problem that involves the use of structured lighting using a low-cost laser beam, a CMOS camera and a Gaussian singleton fuzzy logic controller. To validate the proposed control system, a robotic cell was designed using an industrial KUKA KR16 robot for welding metallic plates. The method was evaluated experimentally under lateral and vertical positioning errors

Alternative system to measure hydrogen content in molten aluminium using an electrochemical sensor

The most reliable techniques for the direct measurement of hydrogen content in liquid aluminium are based on Sievert’s law or use electrochemical probes introduced directly in liquid aluminium. The main drawback of these methods is the high cost of the equipment. An alternative apparatus has been developed and tested. This equipment combines a widely used and much cheaper hydrogen electrochemical sensor with the procedure already patented and commonly used by gas recirculation techniques. The device has been constructed and calibrated using gaseous mixtures of known hydrogen content. For validation, the results obtained with this apparatus have been compared with hydrogen content measurements in liquid aluminium using the commercial Alscan equipment in an industrial facility. Experimental results suggest that the apparatus proposed in this work is capable of detecting hydrogen content in liquid aluminium obtaining measurements that are in a good agreement with those obtained using the commercial Alscan equipment. On the other hand, results also suggest that it is important to take into account the operating atmospheric pressure to correct the readings obtained from Alscan when operating at atmospheric pressure levels far from 1 atm

Final results from the PERUSE study of first-line pertuzumab plus trastuzumab plus a taxane for HER2-positive locally recurrent or metastatic breast cancer, with a multivariable approach to guide prognostication

Background: The phase III CLinical Evaluation Of Pertuzumab And TRAstuzumab (CLEOPATRA) trial established the combination of pertuzumab, trastuzumab and docetaxel as standard first-line therapy for human epidermal growth factor receptor 2 (HER2)-positive locally recurrent/metastatic breast cancer (LR/mBC). The multicentre single-arm PERtUzumab global SafEty (PERUSE) study assessed the safety and efficacy of pertuzumab and trastuzumab combined with investigator-selected taxane in this setting. Patients and methods: Eligible patients with inoperable HER2-positive LR/mBC and no prior systemic therapy for LR/mBC (except endocrine therapy) received docetaxel, paclitaxel or nab-paclitaxel with trastuzumab and pertuzumab until disease progression or unacceptable toxicity. The primary endpoint was safety. Secondary endpoints included progression-free survival (PFS) and overall survival (OS). Prespecified subgroup analyses included subgroups according to taxane, hormone receptor (HR) status and prior trastuzumab. Exploratory univariable analyses identified potential prognostic factors; those that remained significant in multivariable analysis were used to analyse PFS and OS in subgroups with all, some or none of these factors. Results: Of 1436 treated patients, 588 (41%) initially received paclitaxel and 918 (64%) had HR-positive disease. The most common grade 653 adverse events were neutropenia (10%, mainly with docetaxel) and diarrhoea (8%). At the final analysis (median follow-up: 5.7 years), median PFS was 20.7 [95% confidence interval (CI) 18.9-23.1] months overall and was similar irrespective of HR status or taxane. Median OS was 65.3 (95% CI 60.9-70.9) months overall. OS was similar regardless of taxane backbone but was more favourable in patients with HR-positive than HR-negative LR/mBC. In exploratory analyses, trastuzumab-pretreated patients with visceral disease had the shortest median PFS (13.1 months) and OS (46.3 months). Conclusions: Mature results from PERUSE show a safety and efficacy profile consistent with results from CLEOPATRA and median OS exceeding 5 years. Results suggest that paclitaxel is a valid alternative to docetaxel as backbone chemotherapy. Exploratory analyses suggest risk factors that could guide future trial design

Out-of-Control Multivariate Patterns Recognition Using D2 and SVM: A Study Case for GMAW

Industrial processes seek to improve their quality control, including new technologies and satisfying requirements for globalised markets. In this paper, we present an innovative method based on Multivariate Pattern Recognition (MVPR) and process monitoring in a real-world study case. By identifying a distinctive out-of-control multivariate pattern using the Support Vector Machines (SVM) and the Mahalanobis Distance D2 it is possible to infer the variables that disturbed the process; hence, possible faults can be predicted knowing the state of the process. The method is based on our previous work, and in this paper we present the method application for an automated process, namely, the robotic Gas Metal Arc Welding (GMAW). Results from the application indicate an overall accuracy up to 88.8%, which demonstrates the effectiveness of the method, which can also be used in other MVPR tasks

A New Method for the Design of Interval Type-3 Fuzzy Logic Systems With Uncertain Type-2 Non-Singleton Inputs (IT3 NSFLS-2): A Case Study in a Hot Strip Mill

This paper presents a new method for the construction and training of interval type-3 fuzzy logic systems whose inputs are uncertain type-2 non-singleton numbers (IT3 NSFLS-2). The proposed methodology is divided in two processes: 1) The novel construction of the structure of the IT3 NSFLS-2 systems based on: a) The level-alpha-0 of the interval type-2 fuzzy logic system (IT2-alpha-0 FLS), and on b) The secondary membership function using Gaussian modeling to construct each rule of the alpha-k fuzzy rule base (FRB), the firing intervals of the antecedent and the centroids of the consequent, and 2) The training methodology based on gradient descent algorithm to train the antecedent and consequent parameters of the alpha-0 FRB. The primary membership functions (MF) of the antecedents of the IT3 NSFLS-2 system are modeled as Gaussians with uncertain means and with common standard deviation. The proposal was applied and tested with the prediction of a transfer bar’s surface temperature in an industrial hot strip mill facility located in Monterrey México. The modeling results show that the proposal supports the stability required by this critical process and shows the best performance when compared with similar methods