Deep convolutional neural network for weld defect classification in radiographic images.

The quality of welds is critical to the safety of structures in construction, so early detection of irregularities is crucial. Advances in machine vision inspection technologies, such as deep learning models, have improved the detection of weld defects. This paper presents a new CNN model based on ResNet50 to classify four types of weld defects in radiographic images: crack, pore, non-penetration, and no defect. Stratified cross-validation, data augmentation, and regularization were used to improve generalization and avoid over-fitting. The model was tested on three datasets, RIAWELC, GDXray, and a private dataset of low image quality, obtaining an accuracy of 98.75 %, 90.255 %, and 75.83 %, respectively. The model proposed in this paper achieves high accuracies on different datasets and constitutes a valuable tool to improve the efficiency and effectiveness of quality control processes in the welding industry. Moreover, experimental tests show that the proposed approach performs well on even low-resolution images.

Machine learning regression algorithms to predict emissions from steam boilers.

Currently, the modeling of complex chemical-physical processes is drastically influencing industrial development. Therefore, the analysis and study of the combustion process of the boilers using machine learning (ML) techniques are vital to increase the efficiency with which this equipment operates and reduce the pollution load they contribute to the environment. This work aims to predict the emissions of CO, CO2, NOx, and the temperature of the exhaust gases of industrial boilers from real data. Different ML algorithms for regression analysis are discussed. The following are input variables: ambient temperature, working pressure, steam production, and the type of fuel used in around 20 industrial boilers. Each boiler's emission data was collected using a TESTO 350 Combustion Gas Analyzer. The modeling, with a machine learning approach using the Gradient Boosting Regression algorithm, showed better performance in the predictions made on the test data, outperforming all other models studied. It was achieved with predicted values showing a mean absolute error of 0.51 and a coefficient of determination of 99.80%. Different regression models (DNN, MLR, RFR, GBR) were compared to select the most optimal. Compared to models based on Linear Regression, the DNN model has better prediction performance. The proposed model provides a new method to predict CO2, CO, NOx emissions, and exhaust gas outlet temperature.

Modeling and control of the hydraulic actuator in a ladle furnace.

The dynamic behavior of the hydraulic actuator in a system for regulating the electrode's position is crucial for the operation of a Ladle Furnace. This work aims to identify, model, and control the hydraulic actuator in the Ladle Furnace of ACINOX Las Tunas. For identifying the system, input signals of Pseudo-Random Binary type and black box models were used. As a result, three models were obtained, two reflecting the process's asymmetric behavior according to the upward or downward movement. The third model approximates the process dynamic behavior around the operating point and includes the uncertainty caused by the weight variation during the electrode wear. The models obtained, with a fit greater than 85%, allow a better understanding of the study case behavior. In addition, these allowed the evaluation of the electrode's weight variation and tuning of several controllers. The optimal one was a novel non-linear PI controller of guaranteed robustness. In future works, the use of a non-linear function could be evaluated to compensate for the asymmetric behavior of the process.

Low-Temperature Hydrophilic Pervaporation of Lactic Acid Esterification Reaction Media.

Esterification reactions show a limited conversion due to the presence of water, which favors the opposite reaction. The removal of water from the reaction mixture increases the production of the ester. Pervaporation is an effective dehydration technique, usually applied to binary mixtures. The effect on pervaporation of a reactive multicomponent system involving water, ethanol, ethyl lactate and lactic acid with high acid concentration (13.5 wt. %) at relatively low temperatures (40-80 °C) was studied. Three hydrophilic membranes mainly fabricated for dehydration purposes from Sulzer Chemtech were used, i.e., PERVAP™ 3100, PERVAP™ 2216 and PERVAP™ 1131. The last one revealed as the most suitable for the application and it was further characterized with binary and ternary solutions. The membrane showed high affinity for the lactic acid. The acid permeation played a key role in the water/ethanol and water/ethyl lactate selectivity. Lactic acid permeates and crystalizes in the permeate side of the membrane at very low water concentration (below 2 wt. %), causing a drop in flux and membrane selectivity. Ethyl lactate is responsible of the loss of integrity of the membranes.

Treatment of Aqueous Effluents from Steel Manufacturing with High Thiocyanate Concentration by Reverse Osmosis.

The feasibility of reverse osmosis (RO) for treating coking wastewaters from a steel manufacturing plant, rich in ammonium thiocyanate was assessed. DOW FILMTECTM SW30 membrane performance with synthetic and real thiocyanate-containing solutions was established at the laboratory and (onsite) pilot plant scale. No short-term fouling was observed, and the data followed the known solution-diffusion model and the film theory. Those models, together with non-steady state mass balances, were used in simulations that aided to design a full scale two-stage RO plant for thiocyanate separation.

Intra- and Inter-rater Agreement of Superior Vena Cava Flow and Right Ventricular Outflow Measurements in Late Preterm and Term Neonates.

OBJECTIVES: To explore the intra- and inter-rater agreement of superior vena cava (SVC) flow and right ventricular (RV) outflow in healthy and unwell late preterm neonates (33-37 weeks' gestational age), term neonates (≥37 weeks' gestational age), and neonates receiving total-body cooling. METHODS: The intra- and inter-rater agreement (n = 25 and 41 neonates, respectively) rates for SVC flow and RV outflow were determined by echocardiography in healthy and unwell late preterm and term neonates with the use of Bland-Altman plots, the repeatability coefficient, the repeatability index, and intraclass correlation coefficients. RESULTS: The intra-rater repeatability index values were 41% for SVC flow and 31% for RV outflow, with intraclass correlation coefficients indicating good agreement for both measures. The inter-rater repeatability index values for SVC flow and RV outflow were 63% and 51%, respectively, with intraclass correlation coefficients indicating moderate agreement for both measures. CONCLUSIONS: If SVC flow or RV outflow is used in the hemodynamic treatment of neonates, sequential measurements should ideally be performed by the same clinician to reduce potential variability.

Meningitis aséptica como complicación del tratamiento con inmunoglobulinas en la miastenia grave / Aseptic meningitis as a complication of immunoglobulin treatment in myasthenia gravis

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DNA/RNA transverse current sequencing: intrinsic structural noise from neighboring bases.

Nanopore DNA sequencing via transverse current has emerged as a promising candidate for third-generation sequencing technology. It produces long read lengths which could alleviate problems with assembly errors inherent in current technologies. However, the high error rates of nanopore sequencing have to be addressed. A very important source of the error is the intrinsic noise in the current arising from carrier dispersion along the chain of the molecule, i.e., from the influence of neighboring bases. In this work we perform calculations of the transverse current within an effective multi-orbital tight-binding model derived from first-principles calculations of the DNA/RNA molecules, to study the effect of this structural noise on the error rates in DNA/RNA sequencing via transverse current in nanopores. We demonstrate that a statistical technique, utilizing not only the currents through the nucleotides but also the correlations in the currents, can in principle reduce the error rate below any desired precision.

A management guideline to reduce the frequency of blood transfusion in very-low-birth-weight infants.

Very-low-birth-weight (VLBW) infants often require blood transfusions for anemia. Studies have investigated the preventative effect of delayed cord clamping, high-dose iron, and costly recombinant erythropoietin. As part of our unit clinical governance framework to improving patient care, we audited the effect of a preventative management guideline that combines delayed cord clamping for 30 seconds with early protein intake and early oral iron supplementation (6 mg/kg from days 7 to 10 of life, if milk feeds 60 mL/kg/d) combined with a restrictive transfusion policy in infants < 32 weeks' gestation and < 1500 g birth weight. Data on blood transfusions in VLBW infants during the first 6 weeks of life collected before the start of the new regimen (period I) were compared with data in consecutively born VLBW infants after the introduction of the management guideline (period II). Age (in days) when milk feeds and oral iron supplements were introduced was recorded. Statistical analysis used Wilcoxon signed-rank test. VLBW infants in period I ( N = 18, median birth weight 1001 g [727; 1158]) received a median of four transfusions (0.75; 9) compared with 1.5 (0.75; 5, P = 0.01) VLBW infant transfusions in period II ( N = 22, median birth weight 967 g [792; 1131]). Milk feeds of 60 mL/kg/d were achieved on median day 12 (6; to 16), and iron was introduced on median day 38 (21; to 44) in period I compared with milk feeds on day 9 (7; 15, P = 0.05) and oral iron on day 16 (11; 21, P < 0001) in period II. The combination of a 30-second delay in cord clamping, early protein and iron, and a change of transfusion thresholds reduced the number of blood transfusions by half.

Reemplazos articulares de cadera: estudio tribológico del polietileno de ultra alto peso molecular / Replacements hip articulares: study tribological of the high molecular weight polyethylene

El polietileno de ultra alto peso molecular es un material con excelentes propiedades, por lo que ha sido escogido en la construcción de implantes ortopédicos utilizados en remplazos articulares desde hace 30 años. Se realizó un estudio experimental para evaluar la fricción y el desgaste del PUAPM utilizado en copasacetabulares. Los ensayos se realizaron bajo la configuración bola sobre disco, en condiciones secas y con lubricante, utilizando carga de 10 Nw y distancia de deslizamiento de 1000 m. Los pares tribológicos ensayados fueron discos de polietileno, bolas de alúmina y acero inoxidable (AISI 3049). El par alúmina/ polietileno presentó valores de fricción y volumen de desgaste menor que el par acero inoxidable/ polietileno juega un papel importante en la fricción y el desgaste deslizante. El par alúmina/ polietileno representa una buena opción para su aplicación en reemplazos articulares de cadera.

Repair of bile duct injuries with Gore-Tex vascular grafts: experimental study in dogs.

Bile duct injury is the most feared complication related to biliary tract operations. The goal of this investigation was to offer an alternative treatment that might prevent this complication. Twelve mongrel dogs, thin-walled FEP-ringed Gore-Tex vascular grafts, and Gore-Tex sutures were used in this study. The dogs were randomized into three groups of four according to the length of time of graft implantation: group 1 = 1 month; group 2 = 2 months; and group 3 = 3 months. During the first part of the study, a biliary injury was induced by ligating the middle choledocus after performing a conventional cholecystectomy. During the second part of the study, biliodigestive and biliobiliary anastomosis were performed using Gore-Tex vascular grafts prior to resection of the stenotic area. Initially, an increase in serum bilirubin and alkaline phosphatase levels was noted. Two weeks later, after implantation of the grafts, these values returned to normal. Thin-walled FEP-ringed Gore-Tex vascular grafts were found to be useful in the repair of bile duct injuries, especially in complete transections of the common bile duct. The ductility and flexibility of the material allows any type of anastomosis to be performed, especially when bile duct-gut anastomosis is technically difficult.