ABSTRACT
A study of the peen forming of thin stainless steel metal foils (50 µm thick) using a solid-state ps-pulsed laser, emitting at a wavelength of 1064 nm was conducted. The pitch distance between consecutive laser pulses was kept constant by tuning the laser repetition rate from 0.4 to 10 kHz, and subsequently the scanning speed. The induced bending angle and the radius of curvature were used to measure the effect of the treatment. Their dependence on the pulse energy, the treated area, the distance between lines, and the laser repetition rate was studied. High repetition rates do not allow the sample to cool down, affecting the bending to the point of being negligible. An FEM simulation and experiments were carried out to prove that the increase in temperature due to high repetition rate can relax the stresses induced by laser peen treatment, thus preventing bending in the sample.
ABSTRACT
A study of 250 commercial drugs to act as corrosion inhibitors on steel has been developed by applying the quantitative structure-activity relationship (QSAR) paradigm. Hard-soft acid-base (HSAB) descriptors were used to establish a mathematical model to predict the corrosion inhibition efficiency (IE%) of several commercial drugs on steel surfaces. These descriptors were calculated through third-order density-functional tight binding (DFTB) methods. The mathematical modeling was carried out through autoregressive with exogenous inputs (ARX) framework and tested by fivefold cross-validation. Another set of drugs was used as an external validation, obtaining SD, RMSE, and MSE, obtaining 6.76%, 3.89%, 7.03%, and 49.47%, respectively. With a predicted value of IE% = 87.51%, lidocaine was selected to perform a final comparison with experimental results. By the first time, this drug obtained a maximum IE%, determined experimentally by electrochemical impedance spectroscopy measurements at 100 ppm concentration, of about 92.5%, which stands within limits of 1 SD from the predicted ARX model value. From the qualitative perspective, several potential trends have emerged from the estimated values. Among them, macrolides, alkaloids from Rauwolfia species, cephalosporin, and rifamycin antibiotics are expected to exhibit high IE% on steel surfaces. Additionally, IE% increases as the energy of HOMO decreases. The highest efficiency is obtained in case of the molecules with the highest ω and ΔN values. The most efficient drugs are found with pKa ranging from 1.70 to 9.46. The drugs recurrently exhibit aromatic rings, carbonyl, and hydroxyl groups with the highest IE% values.
Subject(s)
Lidocaine , Quantitative Structure-Activity Relationship , Corrosion , Dielectric Spectroscopy , Lidocaine/pharmacology , Steel/chemistryABSTRACT
We describe a new algorithm for phase determination from a single interferogram with closed fringes based on an unwrapping procedure. Here we use bandpass filtering in the Fourier domain, obtaining two wrapped phases with sign changes corresponding to the orientation of the applied filters. An unwrapping scheme that corrects the sign ambiguities by comparing the local derivatives is then proposed. This can be done, assuming that the phase derivatives do not change abruptly among adjacent areas as occurs with smooth continuous phase maps. The proposed algorithm works fast and is robust against noise, as demonstrated in experimental and simulated data.
ABSTRACT
Se realizó un estudio prospectivo para conocer la correlación entre las concentraciones de IgE total sérica y las pruebas cutáneas por escarificación en 300 pacientes con diagnóstico clínico de rinitis alérgica y asma bronquial extrínseca. La correlación de las concentraciones de IgE aportó un índice de variabilidad de 15.6 por ciento con una sensibilidad diagnóstica de 0.86, lo que confirma que este estudio es indispensable para el diagnóstico, manejo y control del paciente atópico
Subject(s)
Humans , Male , Female , Child, Preschool , Adolescent , Adult , Middle Aged , Asthma/diagnosis , Asthma/immunology , Immunoglobulin E , Immunoglobulin E/analysis , Rhinitis, Allergic, Perennial/diagnosis , Rhinitis, Allergic, Perennial/immunology , Skin Tests/instrumentation , Skin TestsABSTRACT
Se realizó un estudio para conocer la sensibilidad y especificidad de una nueva prueba in vitro (Phadiatrop Pediátric) útil en el diagnóstico de alergia en la edad pediátrica en 65 niños divididos en dos grupos. El grupo 1 (35 pacientes) con diagnóstico de alergia respiratoria (asma, rinitis alérgica o ambas), basaso en la historia clínica, eosinófilos en el moco nasal, determinación de IgE y preuebas cutáneas, y el grupo 2 (30 pacientes) sin diagnóstico de alergia. En ambos grupos se cuantificó la IgE y se realizó la prueba de Phadiatop paediatric. En el grupo I la prueba fue positiva en 28 pacientes (80 por ciento y en el grupo 2 lo fue a dos pacientes (6.6 por ciento) que sifnifica una sensibilidad de 67.5 por ciento, con una especificidad de 88.0 por ciento para esta prueba
