Modeling of composite MRFs with CFT columns and WF beams

Ricardo A. Herrera,Teerawut Muhummud,James M. Ricles,Richard SAuse 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.3

A vast amount of experimental and analytical research has been conducted related to the seismic behavior and performance of concrete filled steel tubular (CFT) columns. This research has resulted in a wealth of information on the component behavior. However, analytical and experimental data for structural systems with CFT columns is limited, and the well-known behavior of steel or concrete structures is assumed valid for designing these systems. This paper presents the development of an analytical model for nonlinear analysis of composite moment resisting frame (CFT-MRF) systems with CFT columns and steel wide-flange (WF) beams under seismic loading. The model integrates component models for steel WF beams, CFT columns, connections between CFT columns and WF beams, and CFT panel zones. These component models account for nonlinear behavior due to steel yielding and local buckling in the beams and columns, concrete cracking and crushing in the columns, and yielding of panel zones and connections. Component tests were used to validate the component models. The model for a CFT-MRF considers second order geometric effects from the gravity load bearing system using a lean-on column. The experimental results from the testing of a four-story CFT-MRF test structure are used as a benchmark to validate the modeling procedure. An analytical model of the test structure was created using the modeling procedure and imposeddisplacement analyses were used to reproduce the tests with the analytical model of the test structure. Good agreement was found at the global and local level. The model reproduced reasonably well the story shear-story drift response as well as the column, beam and connection moment-rotation response, but overpredicted the inelastic deformation of the panel zone.

Applications of BOTDR fiber optics to the monitoring of underground structures

Moffat, Ricardo A.,Beltran, Juan F.,Herrera, Ricardo Techno-Press 2015 Geomechanics & engineering Vol.9 No.3

Three different applications for monitoring displacements in underground structures using a BOTDR-based distributed optical fiber strain sensing system are presented. These applications are related to the strain measurements of (1) instrumented PVC tube designed to be attached to tunnel side wall and ceiling as a sensor; (2) rock bolts for tunnels; and (3) shotcrete lining under loading. The effectiveness of using the proposed strain sensing system is evaluated by carrying out laboratory tests, in-situ measurements, and numerical simulations. The results obtained from this validation process provide confidence that the optical fiber is able to quantify strain fields under a variety of loading conditions and consequently use this information to estimate the behavior of rock mass during mining activity. As the measuring station can be located as far as 1 km of distance, these alternatives presented may increase the safety of the mine during mining process and for the personnel doing the measurements on the field.

Ion Currents Induced by ATP and Angiotensin II in Cultured Follicular Cells of Xenopus laevis

Marcelino Montiel-Herrera,Ana María Zaske,Jesús García-Colunga,Ataúlfo Martínez-Torres,Ricardo Miledi 한국분자세포생물학회 2011 Molecules and cells Vol.32 No.5

Xenopus laevis oocytes are commonly used to study the biophysical and pharmacological properties of foreign ion channels and receptors, but little is known about those endogenously expressed in their enveloping layer of follicular cells (FCs). Whole-cell recordings and the perforated patch-clamp technique in cultured FCs held at -60mV revealed that ATP (20-250 μM) generates inward currents of 465 ± 93 pA (mean ± standard error) in ∼60% of the FCs studied, whereas outward currents of 317 ± 100 pA were found in ∼5% of the cells. The net effect of ATP on the FCs was to activate both mono- and biphasic inward currents,with an associated increase in membrane chloride conductance. Two-microelectrode voltage-clamp recordings of nude oocytes held at -60 mV disclosed that ATP elicited biphasic inward currents, corresponding to the well-known Fin and Sin-like currents. ATP receptor antagonists like suramin, TNP-ATP, and RB2 did not inhibit any of these responses. On the other hand, when using wholecell recordings, 1 μM Ang II yielded smooth inward currents of 157 ± 45 pA in ∼16% of the FC held at -60 mV. The net Ang II response, mediated by the activation of the AT1receptor, was a chloride current inhibited by 10 nM ZD7155. This study will help to better understand the roles of ATP and Ang II receptors in the physiology of X. laevis oocytes.

The Output Regulation Problem for Unmodeled Reference/Disturbance Signals Using High-gain Observers

Jesús Alberto Meda-Campaña,Ricardo Ismael Ancona-Bravo,Jonathan Omega Escobedo-Alva,Tonatiuh Hernández-Cortés,Ricardo Tapia-Herrera 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4

Based on the regulation theory and high-gain observers, in this paper, a controller for tracking and/or rejecting unmodeled but measurable signals is designed. Considering that the measurable reference/disturbance signals are bounded and smooth, it is proven that the missing dynamical models for such signals can be estimated by high-gain observers of dimensions equal to or greater than one. Then, the corresponding high-gain observers are embedded into an auxiliary system, known as the exosystem, allowing in this way, that the regulation theory can be applied and the new equations to be solved are also given. Because the exosystem is directly constructed from the high-gain observers, the proposed controller is robust in the sense that it is capable of tracking/rejecting any bounded and smooth signal as long as the estimations of the high-gain observers are sufficiently accurate. The existence conditions for such a controller are given, and numerical experiments are used to illustrate the efficacy of the proposed approach.

Detection of Clavibacter michiganensis subsp. michiganensis Assisted by Micro- Raman Spectroscopy under Laboratory Conditions

Moisé,s Roberto Vallejo Pé,rez,Hugo Ricardo Navarro Contreras,Jesú,s A. Sosa Herrera,José,Pablo Lara Á,vila,Hugo Magdaleno Ramí,rez Tobí,as,Fernando Dí,az-Barriga Mart& 한국식물병리학회 2018 Plant Pathology Journal Vol.34 No.5

Clavibacter michiganensis subsp. michiganesis (Cmm) is a quarantine-worthy pest in México. The implementation and validation of new technologies is necessary to reduce the time for bacterial detection in laboratory conditions and Raman spectroscopy is an ambitious technology that has all of the features needed to characterize and identify bacteria. Under controlled conditions a contagion process was induced with Cmm, the disease epidemiology was monitored. Micro-Raman spectroscopy (532 nm λ laser) technique was evaluated its performance at assisting on Cmm detection through its characteristic Raman spectrum fingerprint. Our experiment was conducted with tomato plants in a completely randomized block experimental design (13 plants × 4 rows). The Cmm infection was confirmed by 16S rDNA and plants showed symptoms from 48 to 72 h after inoculation, the evolution of the incidence and severity on plant population varied over time and it kept an aggregated spatial pattern. The contagion process reached 79% just 24 days after the epidemic was induced. Micro-Raman spectroscopy proved its speed, efficiency and usefulness as a non-destructive method for the preliminary detection of Cmm. Carotenoid specific bands with wavelengths at 1146 and 1510 cm-1 were the distinguishable markers. Chemometric analyses showed the best performance by the implementation of PCA-LDA supervised classification algorithms applied over Raman spectrum data with 100% of performance in metrics of classifiers (sensitivity, specificity, accuracy, negative and positive predictive value) that allowed us to differentiate Cmm from other endophytic bacteria (Bacillus and Pantoea). The unsupervised KMeans algorithm showed good performance (100, 96, 98, 91 y 100%, respectively).

Detection of Clavibacter michiganensis subsp. michiganensis Assisted by Micro-Raman Spectroscopy under Laboratory Conditions

Perez, Moises Roberto Vallejo,Contreras, Hugo Ricardo Navarro,Herrera, Jesus A. Sosa,Avila, Jose Pablo Lara,Tobias, Hugo Magdaleno Ramirez,Martinez, Fernando Diaz-Barriga,Ramirez, Rogelio Flores,Vazqu The Korean Society of Plant Pathology 2018 Plant Pathology Journal Vol.34 No.5

Clavibacter michiganensis subsp. michiganesis (Cmm) is a quarantine-worthy pest in $M{\acute{e}}xico$. The implementation and validation of new technologies is necessary to reduce the time for bacterial detection in laboratory conditions and Raman spectroscopy is an ambitious technology that has all of the features needed to characterize and identify bacteria. Under controlled conditions a contagion process was induced with Cmm, the disease epidemiology was monitored. Micro-Raman spectroscopy ($532nm\;{\lambda}$ laser) technique was evaluated its performance at assisting on Cmm detection through its characteristic Raman spectrum fingerprint. Our experiment was conducted with tomato plants in a completely randomized block experimental design (13 plants ${\times}$ 4 rows). The Cmm infection was confirmed by 16S rDNA and plants showed symptoms from 48 to 72 h after inoculation, the evolution of the incidence and severity on plant population varied over time and it kept an aggregated spatial pattern. The contagion process reached 79% just 24 days after the epidemic was induced. Micro-Raman spectroscopy proved its speed, efficiency and usefulness as a non-destructive method for the preliminary detection of Cmm. Carotenoid specific bands with wavelengths at 1146 and $1510cm^{-1}$ were the distinguishable markers. Chemometric analyses showed the best performance by the implementation of PCA-LDA supervised classification algorithms applied over Raman spectrum data with 100% of performance in metrics of classifiers (sensitivity, specificity, accuracy, negative and positive predictive value) that allowed us to differentiate Cmm from other endophytic bacteria (Bacillus and Pantoea). The unsupervised KMeans algorithm showed good performance (100, 96, 98, 91 y 100%, respectively).

Testing and modelling of shape memory alloy plates for energy dissipators

Heresi, Pablo,Herrera, Ricardo A.,Moroni, Maria O. Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.14 No.5

Shape memory alloys (SMA) can dissipate energy through hysteresis cycles without significant residual deformation. This paper describes the fabrication and testing of copper-based SMA hourglass-shaped plates for use in energy dissipation devices and the development of a numerical model to reproduce the experiments. The plates were tested under cyclic flexural deformations, showing stable hysteresis cycles without strength degradation. A detailed nonlinear numerical model was developed and validated with the experimental data, using as input the constitutive relationship for the material determined from cyclic tests of material coupons under tension loading. The model adequately reproduces the experimental results. The study is focused on the exploitation of SMA in the martensite phase.

Testing and modelling of shape memory alloy plates for energy dissipators

Pablo Heresi,Ricardo A. Herrera,Maria O. Moroni 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.14 No.5

Shape memory alloys (SMA) can dissipate energy through hysteresis cycles without significant residual deformation. This paper describes the fabrication and testing of copper-based SMA hourglass-shaped plates for use in energy dissipation devices and the development of a numerical model to reproduce the experiments. The plates were tested under cyclic flexural deformations, showing stable hysteresis cycles without strength degradation. A detailed nonlinear numerical model was developed and validated with the experimental data, using as input the constitutive relationship for the material determined from cyclic tests of material coupons under tension loading. The model adequately reproduces the experimental results. The study is focused on the exploitation of SMA in the martensite phase.

Eco-friendly Production of Metallic Nanoparticles in Polymeric Solutions and Their Processing into Biocompatible Composites

Alejandra Pérez-Nava,Josué D. Mota-Morales,Zaira Y. García-Carvajal,Sara E. Herrera-Rodríguez,Gerardo Arrevillaga-Boni,Cristy L. Azanza-Ricardo,Milton O. Vazquez-Lepe,J. Betzabe Gonzalez-Campos 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1

Silver and gold nanoparticles were produced and embedded in poly(vinyl alcohol) (PVA) and chitosan (CTS) solutions by the photoreduction of metallic salt precursors triggered by direct sunlight irradiation, in which the polymers acted as reducing, dispersing and stabilizing agents. Sunlight photoreduction can be standardized using a constant UV index regardless of the season. This strategy was found to be an improvement over other common energy sources used to trigger the reduction of metal ions, including UV light irradiation and high-temperature reduction with mechanical stirring. The resulting PVA/metal nanoparticle and CTS/metal nanoparticle composite solutions were processed into thin films and nanofiber composites. In vitro testing of the cytotoxicity and biocompatibility demonstrates that the film composites are non-toxic andbiocompatible with the HT-29 human colon cancer cell line. Promotion of HT-29 cell growth using our hybrid composites was observed, in contrast to other studies in which colloidal NPs were tested. Therefore, a sustainable approach for the onestep preparation of biocompatible polymer/metallic nanoparticle composites is reported.